Nonlinear modelling of high-speed catenary based on analytical expressions of cable and truss elements

NASA Astrophysics Data System (ADS)

Song, Yang; Liu, Zhigang; Wang, Hongrui; Lu, Xiaobing; Zhang, Jing

2015-10-01

Due to the intrinsic nonlinear characteristics and complex structure of the high-speed catenary system, a modelling method is proposed based on the analytical expressions of nonlinear cable and truss elements. The calculation procedure for solving the initial equilibrium state is proposed based on the Newton-Raphson iteration method. The deformed configuration of the catenary system as well as the initial length of each wire can be calculated. Its accuracy and validity of computing the initial equilibrium state are verified by comparison with the separate model method, absolute nodal coordinate formulation and other methods in the previous literatures. Then, the proposed model is combined with a lumped pantograph model and a dynamic simulation procedure is proposed. The accuracy is guaranteed by the multiple iterative calculations in each time step. The dynamic performance of the proposed model is validated by comparison with EN 50318, the results of the finite element method software and SIEMENS simulation report, respectively. At last, the influence of the catenary design parameters (such as the reserved sag and pre-tension) on the dynamic performance is preliminarily analysed by using the proposed model.

The Effect of a Soap Film on a Catenary: Measurement of Surface Tension from the Triangular Configuration

ERIC Educational Resources Information Center

Behroozi, F.; Behroozi, P. S.

2011-01-01

A chain assumes the well-known shape known as a catenary when it hangs loosely from two points in a gravitational field. The correct solution of the catenary was one of the early triumphs of the newly invented calculus of variations at the end of the 17th century. Here we revisit the catenary and show that, for a chain hanging from a horizontal…

Troubleshooting crude vacuum tower overhead ejector systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lines, J.R.; Frens, L.L.

1995-03-01

Routinely surveying tower overhead vacuum systems can improve performance and product quality. These vacuum systems normally provide reliable and consistent operation. However, process conditions, supplied utilities, corrosion, erosion and fouling all have an impact on ejector system performance. Refinery vacuum distillation towers use ejector systems to maintain tower top pressure and remove overhead gases. However, as with virtually all refinery equipment, performance may be affected by a number of variables. These variables may act independently or concurrently. It is important to understand basic operating principles of vacuum systems and how performance is affected by: utilities, corrosion and erosion, fouling, andmore » process conditions. Reputable vacuum-system suppliers have service engineers that will come to a refinery to survey the system and troubleshoot performance or offer suggestions for improvement. A skilled vacuum-system engineer may be needed to diagnose and remedy system problems. The affect of these variables on performance is discussed. A case history is described of a vacuum system on a crude tower in a South American refinery.« less

Catenaries in viscous fluid

NASA Astrophysics Data System (ADS)

Hanna, James; Chakrabarti, Brato

2015-11-01

Slender structures live in fluid flows across many scales, from towed instruments to plant blades to microfluidic valves. The present work details a simple model of a flexible structure in a uniform flow. We present analytical solutions for the translating, axially flowing equilibria of strings subjected to a uniform body force and linear drag forces. This is an extension of the classical catenaries to a five-parameter family of solutions, represented as trajectories in angle-curvature ``phase space.'' Limiting cases include neutrally buoyant towed cables and freely sedimenting flexible filaments. Now at University of California, San Diego.

Focus on Physics: The Delightful Catenary Curve

ERIC Educational Resources Information Center

Hewitt, Paul G.

2017-01-01

When teaching how "tension" and "compression" relate to geometrical structures such as bridges, arches, and domes, The author shows a picture of the Notre Dame Cathedral in Paris, completed in the 14th century, and presents a lesson on using the curve called a catenary to explain how he teaches about tension and compression…

Structural Analysis of Lightning Protection System for New Launch Vehicle

NASA Technical Reports Server (NTRS)

Cope, Anne; Moore, Steve; Pruss, Richard

2008-01-01

This project includes the design and specification of a lightning protection system for Launch Complex 39 B (LC39B) at Kennedy Space Center, FL in support of the Constellation Program. The purpose of the lightning protection system is to protect the Crew Launch Vehicle (CLV) or Cargo Launch Vehicle (CaLV) and associated launch equipment from direct lightning strikes during launch processing and other activities prior to flight. The design includes a three-tower, overhead catenary wire system to protect the vehicle and equipment on LC39B as described in the study that preceded this design effort: KSC-DX-8234 "Study: Construct Lightning Protection System LC3 9B". The study was a collaborative effort between Reynolds, Smith, and Hills (RS&H) and ASRC Aerospace (ASRC), where ASRC was responsible for the theoretical design and risk analysis of the lightning protection system and RS&H was responsible for the development of the civil and structural components; the mechanical systems; the electrical and grounding systems; and the siting of the lightning protection system. The study determined that a triangular network of overhead catenary cables and down conductors supported by three triangular free-standing towers approximately 594 ft tall (each equipped with a man lift, ladder, electrical systems, and communications systems) would provide a level of lightning protection for the Constellation Program CLV and CaLV on Launch Pad 39B that exceeds the design requirements.

Catenary-induced geometric nonlinearity effects on cable linear vibrations

NASA Astrophysics Data System (ADS)

Mansour, Achref; Mekki, Othman Ben; Montassar, Sami; Rega, Giuseppe

2018-01-01

This paper investigates the free undamped vibrations of cables of arbitrary sag and inclination according to the catenary theory. The proposed approach accounts for the catenary effect on the static profile around which the cable motion is defined. Considering first order geometric nonlinearities, exact expression of the curvature is obtained along with the ensuing correction of the well known Irvine parameter. Taking into account the new characterization, different regions of shallow and non-shallow profiles are identified for various inclinations. In view of such classification, the analysis carried out on cable linear modal properties shows the emergence of new dynamic features such as additional hybrid modes and internal resonances. Analytical and numerical results reduce to those obtained by classic formulations in the cases of both horizontal and inclined shallow/non-shallow cables.

Program for catenary-pantograph analysis, PrOSA statement of methods and validation according EN 50318

NASA Astrophysics Data System (ADS)

Finner, Lars; Poetsch, Gero; Sarnes, Bernhard; Kolbe, Michael

2015-03-01

DB Systemtechnik is a high-performing, customer-driven service provider that, as well as authoritatively serving the Deutsche Bahn Group by dint of its specialist knowledge is also increasingly active on the global railway market. Development and testing of pantograph models and catenary systems have been part of the company's essential activity fields from the beginning. Therefore, an efficient and high-performing simulation tool is indispensable. That is why DB Systemtechnik spent high efforts to develop the program PrOSA in cooperation with the Heinz-Nixdorf-Institut (HNI) of the university Paderborn to simulate the interaction of pantograph and catenary. This article gives an overview of the most relevant properties of PrOSA. Furthermore, it is described how the benchmark requirements were implemented and processed.

Overhead Crane Computer Model

NASA Astrophysics Data System (ADS)

Enin, S. S.; Omelchenko, E. Y.; Fomin, N. V.; Beliy, A. V.

2018-03-01

The paper has a description of a computer model of an overhead crane system. The designed overhead crane system consists of hoisting, trolley and crane mechanisms as well as a payload two-axis system. With the help of the differential equation of specified mechanisms movement derived through Lagrange equation of the II kind, it is possible to build an overhead crane computer model. The computer model was obtained using Matlab software. Transients of coordinate, linear speed and motor torque of trolley and crane mechanism systems were simulated. In addition, transients of payload swaying were obtained with respect to the vertical axis. A trajectory of the trolley mechanism with simultaneous operation with the crane mechanism is represented in the paper as well as a two-axis trajectory of payload. The designed computer model of an overhead crane is a great means for studying positioning control and anti-sway control systems.

Solar radiation on a catenary collector

NASA Technical Reports Server (NTRS)

Crutchik, M.; Appelbaum, J.

1992-01-01

A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector on the other side producing a self shading effect is analyzed. The direct beam, the diffuse and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on the martian surface for the location of Viking Lander 1 (VL1).

Solar radiation on a catenary collector

NASA Technical Reports Server (NTRS)

Crutchik, M.; Appelbaum, J.

1992-01-01

A tent-shaped structure with a flexible photovoltaic blanket acting as a catenary collector is presented. The shadow cast by one side of the collector produces a shadow on the other side of the collector. This self-shading effect is analyzed. The direct beam, the diffuse, and the albedo radiation on the collector are determined. An example is given for the insolation on the collector operating on Viking Lander 1 (VL1).

Experimental and computational investigations on severe slugging in a catenary riser

NASA Astrophysics Data System (ADS)

Duan, Jin-long; Chen, Ke; You, Yun-xiang; Gao, Song

2017-12-01

Severe slugging can occur in a pipeline-riser system at relatively low liquid and gas flow rates during gas-oil transportation, possibly causing unexpected damage to the production facilities. Experiments with air and water are conducted in a horizontal and downward inclined pipeline followed by a catenary riser in order to investigate the mechanism and characteristics of severe slugging. A theoretical model is introduced to compare with the experiments. The results show that the formation mechanism of severe slugging in a catenary riser is different from that in a vertical riser due to the riser geometry and five flow patterns are obtained and analyzed. A gas-liquid mixture slug stage is observed at the beginning of one cycle of severe slugging, which is seldom noticed in previous studies. Based on both experiments and computations, the time period and variation of pressure amplitude of severe slugging are found closely related to the superficial gas velocity, implying that the gas velocity significantly influences the flow patterns in our experiments. Moreover, good agreements between the experimental data and the numerical results are shown in the stability curve and flow regime map, which can be a possible reference for design in an offshore oil-production system.

A photovoltaic catenary-tent array for the Martian surface

NASA Technical Reports Server (NTRS)

Crutchik, M.; Colozza, Anthony J.; Appelbaum, J.

1993-01-01

To provide electrical power during an exploration mission to Mars, a deployable tent-shaped structure with a flexible photovoltaic (PV) blanket is proposed. The array is designed with a self-deploying mechanism utilizing pressurized gas expansion. The structural design for the array uses a combination of cables, beams, and columns to support and deploy the PV blanket. Under the force of gravity a cable carrying a uniform load will take the shape of a catenary curve. A catenary-tent collector is self shadowing which must be taken into account in the solar radiation calculation. The shape and the area of the shadow on the array was calculated and used in the determination of the global radiation on the array. The PV blanket shape and structure dimension were optimized to achieve a configuration which maximizes the specific power (W/kg). The optimization was performed for four types of PV blankets (Si, GaAs/Ge, GaAs CLEFT, and amorphous Si) and four types of structure materials (Carbon composite, Aramid Fiber composite, Aluminum, and Magnesium). The results show that the catenary shape of the PV blanket, which produces the highest specific power, corresponds to zero end angle at the base with respect to the horizontal. The tent angle is determined by the combined effect of the array structure specific mass and the PV blanket output power. The combination of carbon composite structural material and GaAs CLEFT solar cells produce the highest specific power. The study was carried out for two sites on Mars corresponding to the Viking Lander locations. The designs were also compared for summer, winter, and yearly operation.

UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. ...

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

UNIDENTIFIED CATENARY SUSPENSION BRIDGE, SHOWING RIVETED METAL PIERS UNDER CONSTRUCTION. NOTE APPROACH SPANS OF PIPE CONSTRUCTION IN RIGHT BACKGROUND. 3/4 VIEW FROM BELOW. - Clear Fork of Brazos River Suspension Bridge, Spanning Clear Fork of Brazos River at County Route 179, Albany, Shackelford County, TX

Coupled dynamics of a viscoelastically supported infinite string and a number of discrete mechanical systems moving with uniform speed

NASA Astrophysics Data System (ADS)

Roy, Soumyajit; Chakraborty, G.; DasGupta, Anirvan

2018-02-01

The mutual interaction between a number of multi degrees of freedom mechanical systems moving with uniform speed along an infinite taut string supported by a viscoelastic layer has been studied using the substructure synthesis method when base excitations of a common frequency are given to the mechanical systems. The mobility or impedance matrices of the string have been calculated analytically by Fourier transform method as well as wave propagation technique. The above matrices are used to calculate the response of the discrete mechanical systems. Special attention is paid to the contact forces between the discrete and the continuous systems which are estimated by numerical simulation. The effects of phase difference, the distance between the systems and different base excitation amplitudes on the collective behaviour of the mechanical systems are also studied. The present study has relevance to the coupled dynamic problem of more than one railway pantographs and an overhead catenary system where the pantographs are modelled as discrete systems and the catenary is modelled as a taut string supported by continuous viscoelastic layer.

Understanding checkpointing overheads on massive-scale systems : analysis of the IBM Blue Gene/P system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, R.; Naik, H.; Beckman, P.

Providing fault tolerance in high-end petascale systems, consisting of millions of hardware components and complex software stacks, is becoming an increasingly challenging task. Checkpointing continues to be the most prevalent technique for providing fault tolerance in such high-end systems. Considerable research has focussed on optimizing checkpointing; however, in practice, checkpointing still involves a high-cost overhead for users. In this paper, we study the checkpointing overhead seen by various applications running on leadership-class machines like the IBM Blue Gene/P at Argonne National Laboratory. In addition to studying popular applications, we design a methodology to help users understand and intelligently choose anmore » optimal checkpointing frequency to reduce the overall checkpointing overhead incurred. In particular, we study the Grid-Based Projector-Augmented Wave application, the Carr-Parrinello Molecular Dynamics application, the Nek5000 computational fluid dynamics application and the Parallel Ocean Program application-and analyze their memory usage and possible checkpointing trends on 65,536 processors of the Blue Gene/P system.« less

Partial feedback linearization control for 3-D underactuated overhead crane systems.

PubMed

Wu, Xianqing; He, Xiongxiong

2016-11-01

In this paper, a novel anti-swing control method is proposed for 3-dimensional (3-D) underactuated overhead crane systems, which guarantees fast transportation and efficient swing suppression. Specifically, to increase the performance of the payload swing suppression, a swing-suppressing element is introduced, based on which a novel positioning error signal is constructed. Then, a new control method is developed, and the overall system is divided into two subsystems. The stability analysis of the two subsystems and the overall system is given. In addition, the convergence of the system states is proved. Simulation results are provided to demonstrate the superior performance of the proposed controller over the existing controllers. Meanwhile, the practical performance of the proposed controller is experimentally validated on a portable overhead crane test-bed. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

The fallacy of the overhead quick fix.

PubMed

Blaxill, M F; Hout, T M

1991-01-01

Facing pressure from a few large, low-cost competitors, Thornton, an old-guard specialty-equipment manufacturer, fought back by eliminating overhead. Over two-years, it outsourced components and consolidated operations. But instead of cutting overhead, it added more and became still more uncompetitive. Thornton is not alone in either its predicament or its failed reaction. Many large manufacturing companies are finding themselves at a cost disadvantage in markets they have dominated for years. One reason is excessive overhead structures, the result of an unchecked buildup of indirect employees needed to control rising organizational complexity. Another reason is the emergence of the "robust" competitor, comparable in size and product scope but able to produce at a lower unit overhead cost. Data collected from more than 100 manufacturing plants worldwide illustrate the differences between overhead cost structures of bureaucratic, niche, and robust companies. The gulf between these groups highlights the need for action by bureaucratic companies, and, in some cases, by niche companies. But high-overhead companies are doomed if they cut overhead out of the system either by outsourcing or downsizing. If they expect to retain their size and also become more cost competitive, they must rethink their manufacturing systems. Well-designed and well-controlled processes mean higher product quality, faster cycle time, improved flexibility, and lower overhead costs. Sustainable overhead reduction means a commitment to continuous improvement. This includes segmenting, mapping, and measuring existing processes and then working to improve them.(ABSTRACT TRUNCATED AT 250 WORDS)

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

1. General view, east end and north side. View to ...

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

1. General view, east end and north side. View to southwest toward San Francisco-Oakland Bay Bridge, along general alignment of former Interurban Electric Railway main line. Note truncated catenary support arms on power poles; these originally carried overhead power supply catenary line for the electrically-powered interurban cars. - Interurban Electric Railway Bridge Yard Shop, Interstate 80 at Alameda County Postmile 2.0, Oakland, Alameda County, CA

Kennedy Space Center (KSC) Pad B Catenary Capability Analysis and Technical Exchange Meeting (TEM) Support

NASA Technical Reports Server (NTRS)

Wilson, Timmy R.; Kichak, Robert; Rakov, Vladimir; Kithil, Richard, Jr.; Sargent, Noel B.

2009-01-01

The existing lightning protection system at Pad 39B for the Space Shuttle is an outgrowth of a system that was put in place for the Apollo Program. Dr. Frank Fisher of Lightning Technologies was a key participant in the design and implementation of that system. He conveyed to the NESC team that the catenary wire provision was put in place quickly (as assurance against possible vehicle damage causing critical launch delays) rather than being implemented as a comprehensive system designed to provide a high degree of guaranteed protection. Also, the technology of lightning protection has evolved over time with considerable work being conducted by groups such as the electric utilities companies, aircraft manufacturers, universities, and others. Several accepted present-day methods for analysis of lightning protection were used by Drs. Medelius and Mata to study the expected lightning environment for the Pad 39B facility and to analyze the degree of protection against direct lightning attachment to the Space Shuttle. The specific physical configuration directly affects the vulnerability, so cases that were considered included the RSS next to and rolled back from the Space Shuttle, and the GOx Vent Arm both extended and withdrawn from the ET. Elements of the lightning protection system at Pad 39B are shown in Figure 6.0-1 and consist of an 80 foot insulating mast on top of the Fixed Support Structure (FSS), a catenary wire system that runs from the mast in a North/South direction to grounds 1000 feet away on each side of the mast, the RSS which can either be next to or away from the Space Shuttle, and a GOx vent that can either be extended or retracted from the top of the ET.

Wideband analysis of railway catenary line radiation and new applications of its unintentional emitted signals

NASA Astrophysics Data System (ADS)

Heddebaut, Marc; Deniau, Virginie; Rioult, Jean

2018-06-01

Generally, in railway networks, dissipated energy—and its consequences in terms of noise, ballast attrition, electromagnetic interference, etc—is considered a nuisance generated by this means of transport. Therefore, most studies are carried out with the aim of reducing it. This paper takes the opposite view and considers the particular case of the irreducible electromagnetic interference generated along an electrified line, in order to propose new applications beneficial to railway operations. At a selected representative location, wideband (ranging from 10 kHz to 1 GHz) electromagnetic field measurements are performed successively during, and not during, high speed train passages. We deduce two potential applications of these unintentional signals. At low frequency, the first proposal considers energy harvesting using the received electromagnetic interference as the source. This received energy can be converted and used to DC feed low consumption sensors to be installed along the railway infrastructure. These sensors participate in monitoring infrastructure health and in making it more resilient to internal and external stresses. At higher frequencies, for the second proposal, radiation from the catenary line and train pantograph is specifically examined at a carefully selected sub-band. The results are also studied following a time–frequency analysis, to introduce a new nondestructive inspection method of the sliding contact between the catenary line and the train pantograph. Ultimately, this technique could offer a new means of monitoring the health of both the catenary line and the pantograph.

Variation in predicting pantograph-catenary interaction contact forces, numerical simulations and field measurements

NASA Astrophysics Data System (ADS)

Nåvik, Petter; Rønnquist, Anders; Stichel, Sebastian

2017-09-01

The contact force between the pantograph and the contact wire ensures energy transfer between the two. Too small of a force leads to arching and unstable energy transfer, while too large of a force leads to unnecessary wear on both parts. Thus, obtaining the correct contact force is important for both field measurements and estimates using numerical analysis. The field contact force time series is derived from measurements performed by a self-propelled diagnostic vehicle containing overhead line recording equipment. The measurements are not sampled at the actual contact surface of the interaction but by force transducers beneath the collector strips. Methods exist for obtaining more realistic measurements by adding inertia and aerodynamic effects to the measurements. The variation in predicting the pantograph-catenary interaction contact force is studied in this paper by evaluating the effect of the force sampling location and the effects of signal processing such as filtering. A numerical model validated by field measurements is used to study these effects. First, this paper shows that the numerical model can reproduce a train passage with high accuracy. Second, this study introduces three different options for contact force predictions from numerical simulations. Third, this paper demonstrates that the standard deviation and the maximum and minimum values of the contact force are sensitive to a low-pass filter. For a specific case, an 80 Hz cut-off frequency is compared to a 20 Hz cut-off frequency, as required by EN 50317:2012; the results show an 11% increase in standard deviation, a 36% increase in the maximum value and a 19% decrease in the minimum value.

Ammonium salt corrosion in hydrotreating unit stripper column overhead systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shargay, C.A.; Jacobs, G.E.; Price, M.D.

In the past, the presence of ammonium bisulfide (NH{sub 4}HS) or ammonium chloride (NH{sub 4}Cl) in hydrotreater stripper overheads was relatively rare. However, designs of newer units and revamps to older units, are resulting in corrosive levels of NH{sub 4}HS or NH{sub 4}Cl in overhead systems. This is primarily due to the addition of a hot high pressure separator (HHPS) with the bottoms going directly (or through another separator) to the stripper. This paper presents data on one corrosion case history in detail, a summary of another case history reported in Retln-Cor 3.0 and the results of a brief surveymore » targeted to units with HHPS designs. Some correlations of the process conditions to the severity of corrosion are made based on the survey results, and recommended materials selection and other corrosion control methods to minimize the risk of this problem are given.« less

Overhead traffic detector mounting system (Phase 2).

DOT National Transportation Integrated Search

2007-04-01

Caltrans has funded the development of a new family of out-of-pavement electronic sensing devices for the purpose of monitoring certain characteristics of highway traffic. One promising example is a laser based overhead detector recently developed at...

An overhead specimen handling system for variable workloads.

PubMed

Eggert, A A; Bowers, K L; Smulka, G J; Emmerich, K A; Iwanski, A L; Quam, E F

1999-02-01

This unique overhead specimen handling system requires virtually no floor space and only a minimal amount of bench space. It uses state-of-the-art conveyors suspended near the ceiling to transport, log-in and sort blood specimens in standard specimen containers. Specimens placed into the system at bench-level bins are automatically singulated and loaded onto cleated conveyors and lifted to the main conveyor belt near the ceiling. The barcoded labels are then read as the containers are rotated under an optical scanner. The specimens are then diverted to the appropriate branch conveyor and lowered back to the bench level by cleated conveyors. The specimen handling system is rapid and accurate, requires no special containers, allows laboratorians to move unimpeded below it, and is inexpensive by automation standards. Studies show no adverse effect upon the specimens.

75 FR 31803 - Notice of Issuance of Final Determination Concerning a Lift Unit for an Overhead Patient Lift System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

... Determination Concerning a Lift Unit for an Overhead Patient Lift System AGENCY: U.S. Customs and Border... concerning the country of origin of a lift unit for an overhead patient lift system. Based upon the facts presented, CBP has concluded in the final determination that Sweden is the country of origin of the lift...

Variance analysis refines overhead cost control.

PubMed

Cooper, J C; Suver, J D

1992-02-01

Many healthcare organizations may not fully realize the benefits of standard cost accounting techniques because they fail to routinely report volume variances in their internal reports. If overhead allocation is routinely reported on internal reports, managers can determine whether billing remains current or lost charges occur. Healthcare organizations' use of standard costing techniques can lead to more realistic performance measurements and information system improvements that alert management to losses from unrecovered overhead in time for corrective action.

Effective Determination of Overhead Rates for Pricing Goods and Services.

ERIC Educational Resources Information Center

Smith, Christopher A.

This publication presents a system of gathering overhead data and describes several methods for assigning overhead costs to specific contract prices. It is intended to provide facility production supervisors with a means of ensuring adequate cost recovery in bid prices and gaining a measure of overhead cost control. The seven steps in the overhead…

Modeling the Virtual Machine Launching Overhead under Fermicloud

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garzoglio, Gabriele; Wu, Hao; Ren, Shangping

FermiCloud is a private cloud developed by the Fermi National Accelerator Laboratory for scientific workflows. The Cloud Bursting module of the FermiCloud enables the FermiCloud, when more computational resources are needed, to automatically launch virtual machines to available resources such as public clouds. One of the main challenges in developing the cloud bursting module is to decide when and where to launch a VM so that all resources are most effectively and efficiently utilized and the system performance is optimized. However, based on FermiCloud’s system operational data, the VM launching overhead is not a constant. It varies with physical resourcemore » (CPU, memory, I/O device) utilization at the time when a VM is launched. Hence, to make judicious decisions as to when and where a VM should be launched, a VM launch overhead reference model is needed. The paper is to develop a VM launch overhead reference model based on operational data we have obtained on FermiCloud and uses the reference model to guide the cloud bursting process.« less

Behavioral economics. Avoiding overhead aversion in charity.

PubMed

Gneezy, Uri; Keenan, Elizabeth A; Gneezy, Ayelet

2014-10-31

Donors tend to avoid charities that dedicate a high percentage of expenses to administrative and fundraising costs, limiting the ability of nonprofits to be effective. We propose a solution to this problem: Use donations from major philanthropists to cover overhead expenses and offer potential donors an overhead-free donation opportunity. A laboratory experiment testing this solution confirms that donations decrease when overhead increases, but only when donors pay for overhead themselves. In a field experiment with 40,000 potential donors, we compared the overhead-free solution with other common uses of initial donations. Consistent with prior research, informing donors that seed money has already been raised increases donations, as does a $1:$1 matching campaign. Our main result, however, clearly shows that informing potential donors that overhead costs are covered by an initial donation significantly increases the donation rate by 80% (or 94%) and total donations by 75% (or 89%) compared with the seed (or matching) approach. Copyright © 2014, American Association for the Advancement of Science.

29 CFR 1926.1438 - Overhead & gantry cranes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Overhead & gantry cranes. 1926.1438 Section 1926.1438 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Cranes and Derricks in Construction § 1926.1438 Overhead & gantry cranes. (a) Permanently installed overhead and gantry cranes. The requirements of § 1910...

Analysis of defects of overhead facade systems and other light thin-walled structures

NASA Astrophysics Data System (ADS)

Endzhievskiy, L.; Frolovskaia, A.; Petrova, Y.

2017-04-01

This paper analyzes the defects and the causes of contemporary design solutions with an example of overhead facade systems with ventilated air gaps and light steel thin-walled structures on the basis of field experiments. The analysis is performed at all stages of work: design, manufacture, including quality, construction, and operation. Practical examples are given. The main causes of accidents and the accident rate prediction are looked upon and discussed.

Life cycle assessment of overhead and underground primary power distribution.

PubMed

Bumby, Sarah; Druzhinina, Ekaterina; Feraldi, Rebe; Werthmann, Danae; Geyer, Roland; Sahl, Jack

2010-07-15

Electrical power can be distributed in overhead or underground systems, both of which generate a variety of environmental impacts at all stages of their life cycles. While there is considerable literature discussing the trade-offs between both systems in terms of aesthetics, safety, cost, and reliability, environmental assessments are relatively rare and limited to power cable production and end-of-life management. This paper assesses environmental impacts from overhead and underground medium voltage power distribution systems as they are currently built and managed by Southern California Edison (SCE). It uses process-based life cycle assessment (LCA) according to ISO 14044 (2006) and SCE-specific primary data to the extent possible. Potential environmental impacts have been calculated using a wide range of midpoint indicators, and robustness of the results has been investigated through sensitivity analysis of the most uncertain and potentially significant parameters. The studied underground system has higher environmental impacts in all indicators and for all parameter values, mostly due to its higher material intensity. For both systems and all indicators the majority of impact occurs during cable production. Promising strategies for impact reduction are thus cable failure rate reduction for overhead and cable lifetime extension for underground systems.

75 FR 33320 - Notice of Issuance of Final Determination Concerning a Lift Unit for an Overhead Patient Lift...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

... Determination Concerning a Lift Unit for an Overhead Patient Lift System; Correction AGENCY: U.S. Customs and... origin of a lift unit for an overhead patient lift system. The document contained two errors that this... origin of a lift unit for an overhead patient lift system. This document corrects in the DATES section of...

Overhead Projection Cell for Streamline Flow

ERIC Educational Resources Information Center

Waage, Harold M.

1969-01-01

Describes the construction and operation of an overhead projection apparatus designed to demonstrate streamline flow of a liquid. The apparatus consists of a Plexiglass tank containing water in which plates forming the cell are submerged, a constant level reservoir, an overflow device and a system for marking the flow lines with a dye. (LC)

Overhead Projector Demonstrations.

ERIC Educational Resources Information Center

Kolb, Doris, Ed.

1987-01-01

Describes several chemistry demonstrations that use an overhead projector. Some of the demonstrations deal with electrochemistry, and another deals with the reactions of nonvolatile immiscible liquid in water. (TW)

30 CFR 57.16014 - Operator-carrying overhead cranes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Operator-carrying overhead cranes. 57.16014 Section 57.16014 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 57.16014 Operator-carrying overhead cranes. Operator-carrying overhead cranes shall...

30 CFR 56.16014 - Operator-carrying overhead cranes.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Operator-carrying overhead cranes. 56.16014 Section 56.16014 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 56.16014 Operator-carrying overhead cranes. Operator-carrying overhead cranes shall...

30 CFR 56.16014 - Operator-carrying overhead cranes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Operator-carrying overhead cranes. 56.16014 Section 56.16014 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 56.16014 Operator-carrying overhead cranes. Operator-carrying overhead cranes shall...

30 CFR 57.16014 - Operator-carrying overhead cranes.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Operator-carrying overhead cranes. 57.16014 Section 57.16014 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Storage and Handling § 57.16014 Operator-carrying overhead cranes. Operator-carrying overhead cranes shall...

Soft-light overhead illumination systems improve laparoscopic task performance.

PubMed

Takai, Akihiro; Takada, Yasutsugu; Motomura, Hideki; Teramukai, Satoshi

2014-02-01

The aim of this study was to evaluate the impact of attached shadow cues for laparoscopic task performance. We developed a soft-light overhead illumination system (SOIS) that produced attached shadows on objects. We compared results using the SOIS with those using a conventional illumination system with regard to laparoscopic experience and laparoscope-to-target distances (LTDs). Forty-two medical students and 23 surgeons participated in the study. A peg transfer task (LTD, 120 mm) for students and surgeons, and a suture removal task (LTD, 30 mm) for students were performed. Illumination systems were randomly assigned to each task. Endpoints were: total number of peg transfers; percentage of peg-dropping errors; and total execution time for suture removal. After the task, participants filled out a questionnaire on their preference for a particular illumination system. Total number of peg transfers was greater with the SOIS for both students and surgeons. Percentage of peg-dropping errors for surgeons was lower with the SOIS. Total execution time for suture removal was shorter with the SOIS. Forty-five participants (69% in total) evaluated the SOIS for easier task performance. The present results confirm that the SOIS improves laparoscopic task performance, regardless of previous laparoscopic experience or LTD.

What Does It Cost? An Essay on Overheads.

ERIC Educational Resources Information Center

Abrahamson, Brian

1989-01-01

Issues in determination of overhead for cost recovery from research funding sources are discussed, including the need to collect overhead, principles involved in charging for overhead, range of activity types to be considered, classification and calculation of costs, pricing policy, and payment to the university versus payment to its components.…

Overhead Projector Demonstrations.

ERIC Educational Resources Information Center

Kolb, Doris, Ed.

1989-01-01

Described are demonstrations of the optical activity of two sugar solutions, and the effects of various substituents on acid strength using an overhead projector. Materials and procedures for each demonstration are discussed. (CW)

Overhead Projector Demonstrations.

ERIC Educational Resources Information Center

Kolb, Doris, Ed.

1989-01-01

Included are demonstrations using the overhead projector to show change in optical rotation with wavelength and aromatic pi cloud availability, and formation of colored charge-transfer complexes. Instructional techniques unique to these topics are discussed. (CW)

Sex Differences During an Overhead Squat Assessment.

PubMed

Mauntel, Timothy C; Post, Eric G; Padua, Darin A; Bell, David R

2015-08-01

A disparity exists between the rates of male and female lower extremity injuries. One factor that may contribute to this disparity is high-risk biomechanical patterns that are commonly displayed by females. It is unknown what biomechanical differences exist between males and females during an overhead squat. This study compared lower extremity biomechanics during an overhead squat and ranges of motion between males and females. An electromagnetic motion tracking system interfaced with a force platform was used to quantify peak lower extremity kinematics and kinetics during the descent phase of each squat. Range of motion measurements were assessed with a standard goniometer. Differences between male and female kinematics, kinetics, and ranges of motion were identified with t tests. Males displayed greater peak knee valgus angle, peak hip flexion angle, peak vertical ground reaction forces, and peak hip extension moments. Males also displayed less active ankle dorsiflexion with the knee extended and hip internal and external rotation than females. No other differences were observed. The biomechanical differences between males and females during the overhead squat may result from differences in lower extremity ranges of motion. Therefore, sex-specific injury prevention programs should be developed to improve biomechanics and ranges of motion.

Computer-based mechanical design of overhead lines

NASA Astrophysics Data System (ADS)

Rusinaru, D.; Bratu, C.; Dinu, R. C.; Manescu, L. G.

2016-02-01

Beside the performance, the safety level according to the actual standards is a compulsory condition for distribution grids’ operation. Some of the measures leading to improvement of the overhead lines reliability ask for installations’ modernization. The constraints imposed to the new lines components refer to the technical aspects as thermal stress or voltage drop, and look for economic efficiency, too. The mechanical sizing of the overhead lines is after all an optimization problem. More precisely, the task in designing of the overhead line profile is to size poles, cross-arms and stays and locate poles along a line route so that the total costs of the line's structure to be minimized and the technical and safety constraints to be fulfilled.The authors present in this paper an application for the Computer-Based Mechanical Design of the Overhead Lines and the features of the corresponding Visual Basic program, adjusted to the distribution lines. The constraints of the optimization problem are adjusted to the existing weather and loading conditions of Romania. The outputs of the software application for mechanical design of overhead lines are: the list of components chosen for the line: poles, cross-arms, stays; the list of conductor tension and forces for each pole, cross-arm and stay for different weather conditions; the line profile drawings.The main features of the mechanical overhead lines design software are interactivity, local optimization function and high-level user-interface

Theoretical performance of cross-wind axis turbines with results for a catenary vertical axis configuration

NASA Technical Reports Server (NTRS)

Muraca, R. J.; Stephens, M. V.; Dagenhart, J. R.

1975-01-01

A general analysis capable of predicting performance characteristics of cross-wind axis turbines was developed, including the effects of airfoil geometry, support struts, blade aspect ratio, windmill solidity, blade interference and curved flow. The results were compared with available wind tunnel results for a catenary blade shape. A theoretical performance curve for an aerodynamically efficient straight blade configuration was also presented. In addition, a linearized analytical solution applicable for straight configurations was developed. A listing of the computer program developed for numerical solutions of the general performance equations is included in the appendix.

18 CFR 367.52 - Overhead construction costs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... ACT Service Company Property Instructions § 367.52 Overhead construction costs. (a) All overhead construction costs, such as engineering, supervision, general office salaries and expenses, construction... costs. 367.52 Section 367.52 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

18 CFR 367.52 - Overhead construction costs.

Code of Federal Regulations, 2012 CFR

2012-04-01

... ACT Service Company Property Instructions § 367.52 Overhead construction costs. (a) All overhead construction costs, such as engineering, supervision, general office salaries and expenses, construction... costs. 367.52 Section 367.52 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY...

The Overhead System: Production, Implementation and Utilization. 2nd Edition.

ERIC Educational Resources Information Center

Smith, Richard E.; Pearson, Jerry D.

This handbook is designed to help three groups: the administrator who does not have the services of a media specialist, the media specialist who wishes to expand his knowledge or skills, and the classroom teacher who recognizes the value of the overhead as a teaching tool and is looking for practical assistance. Guidelines are provided in 11…

Communication overhead on the Intel Paragon, IBM SP2 and Meiko CS-2

NASA Technical Reports Server (NTRS)

Bokhari, Shahid H.

1995-01-01

Interprocessor communication overhead is a crucial measure of the power of parallel computing systems-its impact can severely limit the performance of parallel programs. This report presents measurements of communication overhead on three contemporary commercial multicomputer systems: the Intel Paragon, the IBM SP2 and the Meiko CS-2. In each case the time to communicate between processors is presented as a function of message length. The time for global synchronization and memory access is discussed. The performance of these machines in emulating hypercubes and executing random pairwise exchanges is also investigated. It is shown that the interprocessor communication time depends heavily on the specific communication pattern required. These observations contradict the commonly held belief that communication overhead on contemporary machines is independent of the placement of tasks on processors. The information presented in this report permits the evaluation of the efficiency of parallel algorithm implementations against standard baselines.

78 FR 77027 - Overhead Clearance (Air-Draft) Accidents

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-20

... No. USCG-2013-0466] Overhead Clearance (Air-Draft) Accidents AGENCY: Coast Guard, DHS. ACTION... clearance (air-draft) accidents. In its petition, which calls for vessel masters to be provided with accurate vertical air draft information, a maritime organization has described 16 overhead clearance...

Simplified Antenna Group Determination of RS Overhead Reduced Massive MIMO for Wireless Sensor Networks.

PubMed

Lee, Byung Moo

2017-12-29

Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices.

Simplified Antenna Group Determination of RS Overhead Reduced Massive MIMO for Wireless Sensor Networks

PubMed Central

2017-01-01

Massive multiple-input multiple-output (MIMO) systems can be applied to support numerous internet of things (IoT) devices using its excessive amount of transmitter (TX) antennas. However, one of the big obstacles for the realization of the massive MIMO system is the overhead of reference signal (RS), because the number of RS is proportional to the number of TX antennas and/or related user equipments (UEs). It has been already reported that antenna group-based RS overhead reduction can be very effective to the efficient operation of massive MIMO, but the method of deciding the number of antennas needed in each group is at question. In this paper, we propose a simplified determination scheme of the number of antennas needed in each group for RS overhead reduced massive MIMO to support many IoT devices. Supporting many distributed IoT devices is a framework to configure wireless sensor networks. Our contribution can be divided into two parts. First, we derive simple closed-form approximations of the achievable spectral efficiency (SE) by using zero-forcing (ZF) and matched filtering (MF) precoding for the RS overhead reduced massive MIMO systems with channel estimation error. The closed-form approximations include a channel error factor that can be adjusted according to the method of the channel estimation. Second, based on the closed-form approximation, we present an efficient algorithm determining the number of antennas needed in each group for the group-based RS overhead reduction scheme. The algorithm depends on the exact inverse functions of the derived closed-form approximations of SE. It is verified with theoretical analysis and simulation that the proposed algorithm works well, and thus can be used as an important tool for massive MIMO systems to support many distributed IoT devices. PMID:29286339

Report on Analyses of WAC Samples of Evaporator Overheads - 2004

DOE Office of Scientific and Technical Information (OSTI.GOV)

OJI, LAWRENCE

2004-08-16

All water received into ETF requires characterization versus the defined Waste Acceptance Criteria. Currently much of the water received by ETF comes from the F and H Evaporator Overheads. Concentration, Storage and Transfer Engineering issued a modified list of species to be determined. In March of 2004, the Tank Farm submitted annual samples from 2F, 2H and 3H Evaporator Overhead streams for characterization to verify compliance with the Effluent Treatment Facility (ETF) Waste Acceptance Criteria (WAC) and to look for organic species. With the exception of high silicon in the 2H and slightly high tritium in 2F evaporator overheads, allmore » the overheads samples were found to be in compliance with the Effluent Treatment Facility WAC. The silicon concentration in the 2H-evaporator overhead, at 44 mg/L, was above the ETF WAC limit of 5 mg/L and tritium at 2.11E+05 dpm/mL in 2F overhead sample was above the ETF WAC limit of 1.2E+05 dpm/mL.« less

New rain shed (Building No. 241), overhead pipeline and raw ...

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

New rain shed (Building No. 241), overhead pipeline and raw water tank T4. Distribution pump house can be seen at the center of building. - Hawaii Volcanoes National Park Water Collection System, Hawaii Volcanoes National Park, Volcano, Hawaii County, HI

Minimizing Overhead for Secure Computation and Fully Homomorphic Encryption: Overhead

DTIC Science & Technology

2015-11-01

many inputs. We also improved our compiler infrastructure to handle very large circuits in a more scalable way. In Jan’13, we employed the AESNI and...Amazon’s elastic compute infrastructure , and is running under a Xen hypervisor. Since we do not have direct access to the bare metal, we cannot...creating novel opportunities for compressing au- thentication overhead. It is especially compelling that existing public key infrastructures can be used

STOCK YARD LOOKING SOUTHEAST SHOWING OVERHEAD YARD CRANE RAIL, THE ...

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

STOCK YARD LOOKING SOUTHEAST SHOWING OVERHEAD YARD CRANE RAIL, THE MALLEABLE CUPOLAS AND EMISSION RECOVERY SYSTEM, OLD SHED ROOF THAT COVERED THE EARLIER MALLEABLE CUPOLA CHARGING CRANE, MALLEABLE FOUNDRY, AND POLLUTION CONTROL BAGHOUSE. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Nondestructive Testing of Overhead Transmission LINES—NUMERICAL and Experimental Investigation

NASA Astrophysics Data System (ADS)

Kulkarni, S.; Hurlebaus, S.

2009-03-01

Overhead transmission lines are periodically inspected using both on-ground and helicopter-aided visual inspection. Factors including sun glare, cloud cover, close proximity to power lines and the rapidly changing visual circumstances make airborne inspection of power lines a particularly hazardous task. In this study, a finite element model is developed that can be used to create the theoretical dispersion curves of an overhead transmission line. The numerical results are then verified with experimental test using a non-contact and broadband laser detection technique. The methodology developed in this study can be further extended to a continuous monitoring system and be applied to other cable monitoring applications, such as bridge cable monitoring, which would otherwise put human inspectors at risk.

A Testing Platform for Validation of Overhead Conductor Aging Models and Understanding Thermal Limits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Irminger, Philip; Starke, Michael R; Dimitrovski, Aleksandar D

2014-01-01

Power system equipment manufacturers and researchers continue to experiment with novel overhead electric conductor designs that support better conductor performance and address congestion issues. To address the technology gap in testing these novel designs, Oak Ridge National Laboratory constructed the Powerline Conductor Accelerated Testing (PCAT) facility to evaluate the performance of novel overhead conductors in an accelerated fashion in a field environment. Additionally, PCAT has the capability to test advanced sensors and measurement methods for accessing overhead conductor performance and condition. Equipped with extensive measurement and monitoring devices, PCAT provides a platform to improve/validate conductor computer models and assess themore » performance of novel conductors. The PCAT facility and its testing capabilities are described in this paper.« less

30 CFR 57.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Work or travel on overhead crane bridges. 57... MINES Materials Storage and Handling § 57.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with...

30 CFR 56.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Work or travel on overhead crane bridges. 56... Materials Storage and Handling § 56.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with substantial...

30 CFR 57.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work or travel on overhead crane bridges. 57... MINES Materials Storage and Handling § 57.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with...

30 CFR 56.16015 - Work or travel on overhead crane bridges.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Work or travel on overhead crane bridges. 56... Materials Storage and Handling § 56.16015 Work or travel on overhead crane bridges. No person shall work from or travel on the bridge of an overhead crane unless the bridge is provided with substantial...

Steel tanks T5 and T4 with overhead pipeline between. Redwood ...

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

Steel tanks T5 and T4 with overhead pipeline between. Redwood tanks seen in background - Hawaii Volcanoes National Park Water Collection System, Hawaii Volcanoes National Park, Volcano, Hawaii County, HI

Fiber Bragg grating sensor for fault detection in high voltage overhead transmission lines

NASA Astrophysics Data System (ADS)

Moghadas, Amin

2011-12-01

A fiber optic based sensor capable of fault detection in both radial and network overhead transmission power line systems is investigated. Bragg wavelength shift is used to measure the fault current and detect fault in power systems. Magnetic fields generated by currents in the overhead transmission lines cause a strain in magnetostrictive material which is then detected by fiber Bragg grating (FBG) sensors. The Fiber Bragg interrogator senses the reflected FBG signals, and the Bragg wavelength shift is calculated and the signals are processed. A broadband light source in the control room scans the shift in the reflected signals. Any surge in the magnetic field relates to an increased fault current at a certain location. Also, fault location can be precisely defined with an artificial neural network (ANN) algorithm. This algorithm can be easily coordinated with other protective devices. It is shown that the faults in the overhead transmission line cause a detectable wavelength shift on the reflected signal of FBG sensors and can be used to detect and classify different kind of faults. The proposed method has been extensively tested by simulation and results confirm that the proposed scheme is able to detect different kinds of fault in both radial and network system.

Identification and location of catenary insulator in complex background based on machine vision

NASA Astrophysics Data System (ADS)

Yao, Xiaotong; Pan, Yingli; Liu, Li; Cheng, Xiao

2018-04-01

It is an important premise to locate insulator precisely for fault detection. Current location algorithms for insulator under catenary checking images are not accurate, a target recognition and localization method based on binocular vision combined with SURF features is proposed. First of all, because of the location of the insulator in complex environment, using SURF features to achieve the coarse positioning of target recognition; then Using binocular vision principle to calculate the 3D coordinates of the object which has been coarsely located, realization of target object recognition and fine location; Finally, Finally, the key is to preserve the 3D coordinate of the object's center of mass, transfer to the inspection robot to control the detection position of the robot. Experimental results demonstrate that the proposed method has better recognition efficiency and accuracy, can successfully identify the target and has a define application value.

Report on Analyses of WAC Samples of Evaporator Overheads - 2004

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oji, L

2005-03-18

In November and December of 2004, the Tank Farm submitted annual samples from 2F, 2H and 3H Evaporator Overhead streams for characterization to verify compliance with the new Effluent Treatment Facility (ETF) Waste Acceptance Criteria (WAC) and to look for organic species. With the exception of slightly high ammonia in the 2F evaporator overheads and high radiation control guide number for the 3H and 2F evaporator overhead samples, all the overheads samples were found to be in compliance with the Effluent Treatment Facility WAC. The ammonium concentration in the 2F-evaporator overhead, at 33 mg/L, was above the ETF waste watermore » collection tank (WWCT) limits of 28 mg/L. The RCG Number for the 3H and 2F evaporator samples at, respectively, 1.38E-02 and 8.24E-03 were higher than the WWCT limit of 7.69E-03. The analytical detection limits for americium-241 and radium-226 in the evaporator samples were not consistently met because of low WWCT detection limits and insufficient evaporator samples.« less

Spectroscopy on the Overhead Projector.

ERIC Educational Resources Information Center

Solomon, Sally; And Others

1994-01-01

Any overhead projector easily can be converted into a simple spectrometer by placing a piece of diffraction grating over the projecting lens. A detailed description of the apparatus and suggested spectroscopy experiments are included. Demonstrations can utilize solutions of cobalt chloride, potassium permanganate, potassium dichromate, or…

1. EAST SIDE OF OVERHEAD BOMB TRANSPORT RACK, WITH BUILDING ...

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

1. EAST SIDE OF OVERHEAD BOMB TRANSPORT RACK, WITH BUILDING 343 AT LEFT AND BUILDING 328 AT RIGHT. VIEW TO WEST. - Rocky Mountain Arsenal, Overhead Bomb Transport Rack, 1580 feet South of December Seventh Avenue; 860 feet West of D Street, Commerce City, Adams County, CO

Ergonomic evaluation of a wearable assistive device for overhead work.

PubMed

Rashedi, Ehsan; Kim, Sunwook; Nussbaum, Maury A; Agnew, Michael J

2014-01-01

Overhead work is an important risk factor for upper extremity (UE) musculoskeletal disorders. We examined the potential of a mechanical arm and an exoskeletal vest as a wearable assistive device (WADE) for overhead work. Twelve participants completed 10 minutes of simulated, intermittent overhead work, using each of three payloads (1.1, 3.4 and 8.1 kg) and with/without the WADE. Ratings of perceived discomfort (RPDs) and electromyography (EMG) were obtained for the upper arms, shoulders and low back. Using the WADE, UE RPDs decreased by ∼50% with the heavier payloads, whereas smaller (∼25%) and non-significant increases in low-back RPDs were found and were relatively independent of payload. Changes in RPDs with WADE use were consistent with physical demands indicated by EMG, though EMG-based differences in fatigue were less apparent. Participants generally preferred using the WADE, particularly with heavier payloads. These results supported the potential utility of a WADE as an intervention for overhead work.

Characteristics and Clinical Outcomes in Overhead Sports Athletes after Rotator Cuff Repair

PubMed Central

Inui, Hiroaki; Ninomiya, Hiroki; Tanaka, Hiroshi; Nobuhara, Katsuya

2017-01-01

Rotator cuff tears in young overhead sports athletes are rare. The pathomechanism causing rotator cuff tears in young overhead athletes is different from that in aged patients. The purpose of this study was to investigate rotator cuff tear characteristics in young overhead sports athletes to reveal the pathomechanism causing these injuries. This study included 25 overhead sports athletes less than 30 years old with atraumatic rotator cuff tears necessitating repair. Rotator cuff tear characteristics were evaluated intraoperatively, including rotator cuff tear shape and injured rotator cuff tendon. Clinical outcome measures were assessed before surgery and at the final follow-up. In this study, 22 patients reported minimal to no shoulder pain and returned to sports without significant complaints at last follow-up. The isolated infraspinatus tendon was most often injured; the incidence rate of the tear at this site was 32% (8 cases). In the deceleration phase of overhead motion, the eccentric contraction force of the ISP (infraspinatus) tendon peaks and the increased load leads to injury at the ISP tendon. The pathomechanism of rotator cuff injuries in young overhead athletes might be not only internal or subacromial impingement, but also these mechanisms. PMID:28702502

A new method for overhead drilling.

PubMed

Rempel, David; Star, Demetra; Barr, Alan; Gibbons, Billy; Janowitz, Ira

2009-12-01

In the construction sector, overhead drilling into concrete or metal ceilings is a strenuous task associated with shoulder, neck and back musculoskeletal disorders due to the large applied forces and awkward arm postures. Two intervention devices, an inverted drill press and a foot lever design, were developed then compared to the usual method by construction workers performing their normal overhead drilling activities (n = 14). While the intervention devices were rated as less fatiguing than the usual method, their ratings on usability measures were worse than the usual method. The study demonstrates that the intervention devices can reduce fatigue; however, additional modifications are necessary in order to improve usability and productivity. Devices designed to improve workplace safety may need to undergo several rounds of field testing and modification prior to implementation.

Geography via the Overhead Projector: Do It This Way, 7.

ERIC Educational Resources Information Center

Best, Thomas D.

This booklet is designed to assist teachers in their use of overhead projectors when teaching geography. With the overhead technique, relationships among patterns can be suggested bit by bit on inexpensive, easily prepared overlays that are projected to sizes appropriate for a particular instructional situation. A general discussion of the…

Evaluation of overhead support inspection program.

DOT National Transportation Integrated Search

2015-01-01

This study evaluated the adequacy and frequency of the current structural support inspection program for overhead : sign supports (including bridge mounted), mast arm signal supports and high mast light supports. While ODOT provides : statewide guida...

Overhead Projector Spectrum of Polymethine Dye: A Physical Chemistry Demonstration

NASA Astrophysics Data System (ADS)

Solomon, Sally; Hur, Chinhyu

1995-08-01

The position of the predominant peak of 1,1'-diethyl-4,4'-cyanine iodide is measured in class using an overhead projector spectrometer, then predicted using the model of a particle-in a one dimensional box. The calculated wavelength is in excellent agreement with the wavelength estimated from the overhead projector spectroscopy experiment.

Optical Jitter Effects on Target Detection and Tracking of Overhead Persistent Infrared Systems

DTIC Science & Technology

2015-12-01

infrared CdSe cadmium selenide DSP Defense Support Program FIR far-infrared FPA focal plane array Ge germanium GEO geostationary earth orbit...HBCRT High Energy Laser Beam Control Research Testbed HEL high energy laser HgCdTe mercury cadmium telluride IR infrared InSb indium antimonide...MOD model MTF modulation transfer function MWIR mid-wave infrared NIR near infrared OPIR overhead persistent infrared PbSe lead selenide

Acromiohumeral Distance and 3-Dimensional Scapular Position Change After Overhead Muscle Fatigue

PubMed Central

Maenhout, Annelies; Dhooge, Famke; Van Herzeele, Maarten; Palmans, Tanneke; Cools, Ann

2015-01-01

Context: Muscle fatigue due to repetitive and prolonged overhead sports activity is considered an important factor contributing to impingement-related rotator cuff pathologic conditions in overhead athletes. The evidence on scapular and glenohumeral kinematic changes after fatigue is contradicting and prohibits conclusions about how shoulder muscle fatigue affects acromiohumeral distance. Objective: To investigate the effect of a fatigue protocol resembling overhead sports activity on acromiohumeral distance and 3-dimensional scapular position in overhead athletes. Design: Cross-sectional study. Setting: Institutional laboratory. Patients or Other Participants: A total of 29 healthy recreational overhead athletes (14 men, 15 women; age = 22.23 ± 2.82 years, height = 178.3 ± 7.8 cm, mass = 71.6 ± 9.5 kg). Intervention(s) The athletes were tested before and after a shoulder muscle-fatiguing protocol. Main Outcome Measure(s) Acromiohumeral distance was measured using ultrasound, and scapular position was determined with an electromagnetic motion-tracking system. Both measurements were performed at 3 elevation positions (0°, 45°, and 60° of abduction). We used a 3-factor mixed model for data analysis. Results: After fatigue, the acromiohumeral distance increased when the upper extremity was actively positioned at 45° (Δ = 0.78 ± 0.24 mm, P = .002) or 60° (Δ = 0.58 ± 0.23 mm, P = .02) of abduction. Scapular position changed after fatigue to a more externally rotated position at 45° (Δ = 4.97° ± 1.13°, P < .001) and 60° (Δ = 4.61° ± 1.90°, P = .001) of abduction, a more upwardly rotated position at 45° (Δ = 6.10° ± 1.30°, P < .001) and 60° (Δ = 7.20° ± 1.65°, P < .001) of abduction, and a more posteriorly tilted position at 0°, 45°, and 60° of abduction (Δ = 1.98° ± 0.41°, P < .001). Conclusions: After a fatiguing protocol, we found changes in acromiohumeral distance and scapular position that corresponded with an impingement

Centripetal Force on an Overhead Projector.

ERIC Educational Resources Information Center

Rheam, Harry

1995-01-01

Describes two simple demonstrations of an object moving in a straight line tangent to the circle if centripetal force is removed. Demonstrations use a pie plate and petri dish with ball bearings to illustrate the phenomena on an overhead projector. (LZ)

29 CFR 1926.554 - Overhead hoists.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 29 Labor 8 2011-07-01 2011-07-01 false Overhead hoists. 1926.554 Section 1926.554 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Helicopters, Hoists, Elevators, and Conveyors...

29 CFR 1926.554 - Overhead hoists.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 29 Labor 8 2014-07-01 2014-07-01 false Overhead hoists. 1926.554 Section 1926.554 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Helicopters, Hoists, Elevators, and Conveyors...

29 CFR 1926.554 - Overhead hoists.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 29 Labor 8 2013-07-01 2013-07-01 false Overhead hoists. 1926.554 Section 1926.554 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Helicopters, Hoists, Elevators, and Conveyors...

29 CFR 1926.554 - Overhead hoists.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 8 2012-07-01 2012-07-01 false Overhead hoists. 1926.554 Section 1926.554 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR CONSTRUCTION Helicopters, Hoists, Elevators, and Conveyors...

Arthroscopic capsular plication for microtraumatic anterior shoulder instability in overhead athletes.

PubMed

Jones, Kristofer J; Kahlenberg, Cynthia A; Dodson, Christopher C; Nam, Denis; Williams, Riley J; Altchek, David W

2012-09-01

Extreme loading conditions at the glenohumeral joint during overhead athletic activities can result in both soft tissue and osseous adaptative changes at the shoulder. Subtle alterations in the stabilizing structures may lead to anterior instability and debilitating shoulder pain with subsequent inability to participate in athletics. There is currently a paucity of data documenting clinical outcomes after arthroscopic capsular plication in overhead athletes who demonstrate objective findings of pain and anterior instability on physical examination. To evaluate outcomes after arthroscopic capsular plication for anterior instability in overhead athletes with an emphasis on postoperative range of motion, postoperative shoulder function, and return to sport. Case series; Level of evidence, 4. The authors identified 20 overhead athletes with debilitating shoulder pain and a failed trial of nonoperative management who underwent arthroscopic capsular plication (12 suture plication, 8 suture anchor plication) for anterior instability related to isolated capsular redundancy. Patients were evaluated with the Single Assessment Numerical Evaluation (SANE) and Kerlan-Jobe Orthopaedic Clinic (KJOC) Shoulder and Elbow Score, and they were interviewed to determine the rate of return to athletic activity. Failures of treatment included patients who demonstrated debilitating pain that precluded return to sport. At a mean follow-up of 3.6 years (range, 2.0-5.5 years), 18 (90%) patients returned to overhead sports, with 17 (85%) at their preinjury level. The mean (SD) SANE score was 86 (17.5%; range, 30%-100%), and the mean (SD) KJOC score was 82 (18.2; range, 28-100). When compared with the contralateral extremity, there were no significant differences in glenohumeral range of motion. Two patients with associated rotator cuff injury experienced persistent pain with overhead activity and were unable to return to sport, representing a 10% failure rate. Arthroscopic capsular plication

16. THE INSTALLATION OF CONVEYORS AND OVERHEAD RAILS ELIMINATED THE ...

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

16. THE INSTALLATION OF CONVEYORS AND OVERHEAD RAILS ELIMINATED THE NEED TO LAY MOLDS OUT ON FLOORS AND HAND-POUR THEM. INSTEAD, WORKERS PULLED LARGE LADLES ALONG OVERHEAD RAILS AND FILLED CONVEYOR-DRIVEN MOLDS WHILE THEY STOOD ON A MOVING PLATFORM THAT TRAVELED AT THE SAME SPEED AS THE MOLD CONVEYOR, CA. 1950. - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Development and modification of a single overhead camshaft 4-valve 4-stroke 135 cc formula varsity race car engine

NASA Astrophysics Data System (ADS)

Abdullah, M. A.; Tamaldin, N.; Rusnandi, H.; Manoharan, T.; Samsir, M. A.

2013-12-01

The engine that was chosen to be developed and modified is Yamaha LC 135 Single Overhead Camshaft (SOHC) 4-valve 4-stroke 135cc liquid-cooled engine. The engine selection is based on the specification, rule and regulation in UTeM Formula Varsity 2012 (FV 2012). The engine performance is determined by engine operating characteristics. The engine air flow affects the filtration, intake and exhaust systems. The heat from the engine rejected to the surrounding through the active cooling system which has radiator and fan. The selection of the engine is based on weighted decision matrix which consists of reliability, operating and maintenance cost, fuel consumption and weight. The score of the matrix is formulated based on relative weighted factor among the selections. It been compared between Yamaha LC 135 Single Overhead Camshaft (SOHC) 4-valve 4-stroke 135cc liquid-cooled engine, Honda Wave 125 X Air Cooled, 4 Cycle Engine Overhead Camshaft (OHC) and Suzuki Shogun RR 4 stroke air cooled Single Overhead Camshaft (SOHC). The modification is applied to the engine through the simulation and tuning of Capacitor Discharge Ignition (CDI).

A Fiber Bragg Grating-Based Dynamic Tension Detection System for Overhead Transmission Line Galloping.

PubMed

Ma, Guo-Ming; Li, Ya-Bo; Mao, Nai-Qiang; Shi, Cheng; Zhang, Bo; Li, Cheng-Rong

2018-01-26

Galloping of overhead transmission lines (OHTLs) may induce conductor breakage and tower collapse, and there is no effective method for long distance distribution on-line galloping monitoring. To overcome the drawbacks of the conventional galloping monitoring systems, such as sensitivity to electromagnetic interference, the need for onsite power, and short lifetimes, a novel optical remote passive measuring system is proposed in the paper. Firstly, to solve the hysteresis and eccentric load problem in tension sensing, and to extent the dynamic response range, an 'S' type elastic element structure with flanges was proposed. Then, a tension experiment was carried out to demonstrate the dynamic response characteristics. Moreover, the designed tension sensor was stretched continuously for 30 min to observe its long time stability. Last but not the least, the sensor was mounted on a 70 m conductor model, and the conductor was oscillated at different frequencies to investigate the dynamic performance of the sensor. The experimental results demonstrate the sensor is suitable for the OHTL galloping detection. Compared with the conventional sensors for OHTL monitoring, the system has many advantages, such as easy installation, no flashover risk, distribution monitoring, better bandwidth, improved accuracy and higher reliability.

30 CFR 220.012 - Overhead allowance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Overhead allowance. 220.012 Section 220.012 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR MINERALS REVENUE MANAGEMENT ACCOUNTING PROCEDURES FOR DETERMINING NET PROFIT SHARE PAYMENT FOR OUTER CONTINENTAL SHELF OIL AND GAS LEASES...

Overhead Door Company of Charleston Information Sheet

EPA Pesticide Factsheets

Overhead Door Company of Charleston (the Company) is located in North Charleston, South Carolina. The settlement involves renovation activities conducted at a property constructed prior to 1978, located in Isle of Palms, South Carolina.

Error tracking control for underactuated overhead cranes against arbitrary initial payload swing angles

NASA Astrophysics Data System (ADS)

Zhang, Menghua; Ma, Xin; Rong, Xuewen; Tian, Xincheng; Li, Yibin

2017-02-01

This paper exploits an error tracking control method for overhead crane systems for which the error trajectories for the trolley and the payload swing can be pre-specified. The proposed method does not require that the initial payload swing angle remains zero, whereas this requirement is usually assumed in conventional methods. The significant feature of the proposed method is its superior control performance as well as its strong robustness over different or uncertain rope lengths, payload masses, desired positions, initial payload swing angles, and external disturbances. Owing to the same attenuation behavior, the desired error trajectory for the trolley for each traveling distance is not needed to be reset, which is easy to implement in practical applications. By converting the error tracking overhead crane dynamics to the objective system, we obtain the error tracking control law for arbitrary initial payload swing angles. Lyapunov techniques and LaSalle's invariance theorem are utilized to prove the convergence and stability of the closed-loop system. Simulation and experimental results are illustrated to validate the superior performance of the proposed error tracking control method.

30 CFR 56.12045 - Overhead powerlines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Overhead powerlines. 56.12045 Section 56.12045 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12045...

30 CFR 56.12045 - Overhead powerlines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Overhead powerlines. 56.12045 Section 56.12045 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12045...

30 CFR 56.12045 - Overhead powerlines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Overhead powerlines. 56.12045 Section 56.12045 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12045...

30 CFR 56.12045 - Overhead powerlines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Overhead powerlines. 56.12045 Section 56.12045 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12045...

30 CFR 56.12045 - Overhead powerlines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Overhead powerlines. 56.12045 Section 56.12045 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Electricity § 56.12045...

A Simple, Low Overhead Data Compression Algorithm for Converting Lossy Compression Processes to Lossless

DTIC Science & Technology

1993-12-01

0~0 S* NAVAL POSTGRADUATE SCHOOL Monterey, California DTIC ELECTE THESIS S APR 11 1994DU A SIMPLE, LOW OVERHEAD DATA COMPRESSION ALGORITHM FOR...A SIMPLE. LOW OVERHEAD DATA COMPRESSION ALGORITHM FOR CONVERTING LOSSY COMPRESSION PROCESSES TO LOSSLESS. 6. AUTHOR(S) Abbott, Walter D., III 7...Approved for public release; distribution is unlimited. A Simple, Low Overhead Data Compression Algorithm for Converting Lossy Processes to Lossless by

Uptake and Accumulation of Pharmaceuticals in Lettuce Under Surface and Overhead Irrigations

NASA Astrophysics Data System (ADS)

Bhalsod, G.; Chuang, Y. H.; Jeon, S.; Gui, W.; Li, H.; Guber, A.; Zhang, W.

2015-12-01

Pharmaceuticals and personal care products are being widely detected in wastewater and surface waters. As fresh water becomes scarcer, interests in using reclaimed water for crop irrigation is intensified. Since reclaimed waters often carry trace levels of pharmaceuticals, accumulation of pharmaceuticals in food crops could increase the risk of human exposure. This study aims to investigate uptake and accumulations of pharmaceuticals in greenhouse-grown lettuce under contrasting irrigation practices (i.e., overhead and surface irrigations). Lettuce was irrigated with water spiked with 11 commonly used pharmaceuticals (acetaminophen, caffeine, carbamazepine, sulfadiazine, sulfamethoxazole, carbadox, trimethoprim, lincomycin hydrochloride, oxytetracycline hydrochloride, monensin sodium, and tylosin). Weekly sampling of lettuce roots, shoots, and soils were continued for 5 weeks, and the samples were freeze dried, extracted for pharmaceuticals and analyzed by LC-MS/MS. Preliminary results indicate that higher concentrations of pharmaceuticals were found in overhead irrigated lettuce compared to surface irrigated lettuce. For carbamezapine, sulfadiazine, trimethoprim, oxytetracycline, and monensin sodium, their concentrations generally increased in lettuce shoots in the overhead treatment over time. However, acetaminophen was found at higher concentrations in both shoots and roots, indicating that acetaminophen can be easily transported in the plant system. This study provides insight on developing better strategies for using reclaimed water for crop irrigations, while minimizing the potential risks of pharmaceutical contamination of vegetables.

Overhead drilling: Comparing three bases for aligning a drilling jig to vertical

PubMed Central

Rempel, David; Star, Demetra; Barr, Alan; Janowitz, Ira

2010-01-01

Problem Drilling overhead into concrete or metal ceilings is a strenuous task done by construction workers to hang ductwork, piping, and electrical equipment. The task is associated with upper body pain and musculoskeletal disorders. Previously, we described a field usability evaluation of a foot lever and inverted drill press intervention devices that were compared to the usual method for overhead drilling. Both interventions were rated as inferior to the usual method based on poor setup time and mobility. Method Three new interventions, which differed on the design used for aligning the drilling column to vertical, were compared to the usual method for overhead drilling by commercial construction workers (n=16). Results The usual method was associated with the highest levels of regional body fatigue and the poorest usability ratings when compared to the three interventions. Conclusion Overall, the ‘Collar Base’ intervention design received the best usability ratings. Impact on Industry Intervention designs developed for overhead drilling may reduce shoulder fatigue and prevent subsequent musculoskeletal disorders. These designs may also be useful for other overhead work such as lifting and supporting materials (e.g., piping, ducts) that are installed near the ceiling. Workplace health and safety interventions may require multiple rounds of field-testing prior to achieving acceptable usability ratings by the end users. PMID:20630276

Early field performance of Acacia koa seedlings grown under subirrigation and overhead irrigation

Treesearch

Anthony S. Davis; Jeremiah R. Pinto; Douglass F. Jacobs

2011-01-01

Koa (Acacia koa A. Gray [Fabaceae]) seedlings were grown with subirrigation and overhead irrigation systems in an effort to characterize post-nursery field performance. One year following outplanting, we found no differences in seedling height or survival, but root-collar diameter was significantly larger for subirrigated seedlings. This indicates that koa seedlings,...

Field evaluation of unlighted overhead guide signs using older drivers : executive summary report.

DOT National Transportation Integrated Search

2003-08-01

Problem: In the preceding Unlighted Overhead Guide : Sign Feasibility Study, it was determined that : the lighting of overhead guide signs on : freeways could be eliminated if white : microprismatic Type VII or Type IX legends : were used on green be...

Limiting electric fields of HVDC overhead power lines.

PubMed

Leitgeb, N

2014-05-01

As a consequence of the increased use of renewable energy and the now long distances between energy generation and consumption, in Europe, electric power transfer by high-voltage (HV) direct current (DC) overhead power lines gains increasing importance. Thousands of kilometers of them are going to be built within the next years. However, existing guidelines and regulations do not yet contain recommendations to limit static electric fields, which are one of the most important criteria for HVDC overhead power lines in terms of tower design, span width and ground clearance. Based on theoretical and experimental data, in this article, static electric fields associated with adverse health effects are analysed and various criteria are derived for limiting static electric field strengths.

Field evaluation of unlighted overhead guide signs using older drivers : research implementation plan.

DOT National Transportation Integrated Search

2006-04-01

STATEMENT OF NEED: In the preceding Unlighted Overhead Guide Sign Feasibility Study, it was determined that the lighting of overhead : guide signs on freeways could be eliminated if white micro-prismatic Type VII or Type IX legends were used on : gre...

Clinical concepts for treatment of the elbow in the adolescent overhead athlete.

PubMed

Ellenbecker, Todd S; Reinold, Michael; Nelson, Cory O

2010-10-01

Injuries to the adolescent elbow are common because of the repetitive overuse inherent in many overhead sport activities. The management of these patients is greatly facilitated through a greater understanding of the demands placed on the upper extremity kinetic chain during these overhead activities as well as a detailed examination and rehabilitation for the entire upper extremity kinetic chain. Particular emphasis on improving rotator cuff strength and muscular endurance, along with scapular stabilization, is a critical part of elbow rehabilitation in these patients. In addition, the use of a strategic and progressive interval sport return program is necessary to minimize reinjury and return the adolescent overhead athlete to full function. Copyright © 2010 Elsevier Inc. All rights reserved.

Numerical noise analysis for insulator of overhead transmission line

NASA Astrophysics Data System (ADS)

Zhang, Yulin; Chen, Yuwen; Huang, Yu

2018-04-01

As an important and complex issue in aero acoustic field, a lot of explorations have been devoted to the wind-induced noise. However, there is still lack of intensive investigations for aerodynamic noise in high-voltage transmission. The overhead transmission line system leads to serious occupational noise exposure in high wind-speed environment, and the noise can even injure the electricians in charge of insulator. By using computational fluid dynamics (CFD) which combined with computational aero acoustics (CAA), this paper predicts the noise generated by insulator of high voltage electricity transmission line which explores in wind environment. The simulation results indicate that the wind velocity, the assembly angle of the insulator and its ribs' distribution are the main contributory factors for the aerodynamic noise. Specifically, when wind velocity is greater than 15m/s, the alteration of noise is not sensitive to the wind velocity; furthermore, when the assembly angle increases from 0°to 60°, the noise decreases gradually, however, if the angle is happening to be 75°or 90°, it would be even greater than that at 0°. In order to inhibit the aerodynamic noise, it is necessary to control the flow blowing across the boundary of the insulator. Consequently, the result indicates that if the outermost rib is shorter than the second one, the noise reduced evidently. This information expects to provide useful help for the extremely suppression of aerodynamic noise, and also supply practical reference material for the design and application of overhead transmission line system.

Overhead Projector Demonstrations: Tilted TOPS: Inclined Plane Projection.

ERIC Educational Resources Information Center

Alyea, Hubert N.

1989-01-01

The construction and uses of a device to facilitate the use of an overhead projector to show chemical reactions is presented. Materials and instructions for construction as well as reactor vessels are discussed. (CW)

Overhead guide sign retroreflectivity and illumination : [technical summary].

DOT National Transportation Integrated Search

2015-01-01

Compared to daylight driving, nighttime driving is more demanding because of visibility : issues, such as a drivers visual acuity, contrast sensitivity, distance judgment, and : color discrimination. Overhead highway signs are very important for e...

49 CFR 214.515 - Overhead covers for existing on-track roadway maintenance machines.

Code of Federal Regulations, 2010 CFR

2010-10-01

... previously equipped with overhead covers for the operator's position, defective covers shall be repaired, and missing covers shall be reinstalled, by March 28, 2005 and thereafter maintained in accordance with the... equipped with overhead covers for the operator's position, the employer shall evaluate the feasibility of...

An Overhead Projection Demonstration of Optical Activity

ERIC Educational Resources Information Center

Hill, John W.

1973-01-01

Describes the use of two polarizing lenses, a yellow filter, an oatmeal bos, a piece of cardboard, a 1,000 ml beaker, and an overhead projector to demonstrate compound optical activity to large classes. Indicates the presence of an accuracy within 1-2 degrees of usually acceptable data. (CC)

Viewing Vertical Objects with an Overhead Projector.

ERIC Educational Resources Information Center

Wild, R. L.

1988-01-01

Discusses the use of an overhead projector for the deflection of a vertical image to a screen. Describes three demonstrations: magnetizing of a steel ball bearing and paper clip; convection currents of a hot liquid within a cold liquid; and oscillation of concentrated salt solution into fresh water. (YP)

Financing, Overhead, and Profit: An In-Depth Discussion of Costs Associated with Third-Party Financing of Residential and Commercial Photovoltaic Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feldman, D.; Friedman, B.; Margolis, R.

Previous work quantifying the non-hardware balance-of-system costs -- or soft costs -- associated with building a residential or commercial photovoltaic (PV) system has left a significant portion unsegmented in an 'other soft costs' category. This report attempts to better quantify the 'other soft costs' by focusing on the financing, overhead, and profit of residential and commercial PV installations for a specific business model. This report presents results from a bottom-up data-collection and analysis of the upfront costs associated with developing, constructing, and arranging third-party-financed residential and commercial PV systems. It quantifies the indirect corporate costs required to install distributed PVmore » systems as well as the transactional costs associated with arranging third-party financing.« less

The Overhead Projector in the Mathematics Classroom.

ERIC Educational Resources Information Center

Lenchner, George

The first section of this pamphlet illustrates and describes the overhead projector, and discusses several of its advantages over other projection devises, including its simplicity of operation, conservation of class time, dynamic effects, image size, etc. The second section describes in some detail materials and methods used to make visuals, then…

Calculation of induced voltages on overhead lines caused by inclined lightning strokes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakakibara, A.

1989-01-01

Equations to calculate the inducing scalar and vector potentials produced by inclined return strokes are shown. Equations are also shown for calculating the induced voltages on overhead lines where horizontal components of inducing vector potential exist. The adequacy of the calculation method is demonstrated by field experiments. Using these equations, induced voltages on overhead lines are calculated for a variety of directions of return strokes.

Fatigue Analysis of Overhead Sign and Signal Structures

DOT National Transportation Integrated Search

1994-05-01

This report documents methods of fatigue analysis for overhead sign and signal structures. The main purpose of this report is to combine pertinent wind loading and vibration theory, fatigue damage theory, and experimental data into a useable fatigue ...

Southeast corner with overhead crane in foreground Bureau of ...

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

Southeast corner with overhead crane in foreground - Bureau of Mines Boulder City Experimental Station, Titanium Development Plant, Date Street north of U.S. Highway 93, Boulder City, Clark County, NV

Rehabilitation of the Overhead Athlete’s Elbow

PubMed Central

Wilk, Kevin E.; Macrina, Leonard C.; Cain, E. Lyle; Dugas, Jeffrey R.; Andrews, James R.

2012-01-01

The activities required during overhead sports, particularly during baseball pitching, produce large forces at the elbow joint. Injuries to the elbow joint frequently occur in the overhead athlete because of the large amount of forces observed during the act of throwing, playing tennis, or playing golf. Injuries may result because of repetitive overuse, leading to tissue failure. Rehabilitation following injury or surgery to the throwing elbow is vital to fully restore normal function and return the athlete to competition as quickly and safely as possible. Rehabilitation of the elbow, whether following injury or postsurgical, must follow a progressive and sequential order, building on the previous phase, to ensure that healing tissues are not compromised. Emphasis is placed on restoring full motion, muscular strength, and neuromuscular control while gradually applying loads to healing tissue. In addition, when one is creating a rehabilitation plan for athletes, it is imperative to treat the entire upper extremity, core, and legs to create and dissipate the forces generated at each joint. PMID:23016113

Orbiter View of Curiosity From Nearly Straight Overhead

NASA Image and Video Library

2012-08-31

Details such as the shadow of the mast on NASA Mars rover Curiosity appear in an image taken Aug. 17, 2012, by the HiRISE camera on NASA Mars Reconnaissance Orbiter, from more directly overhead than previous HiRISE images of Curiosity.

2. TYPICAL OVERHEAD WIRE CONSTRUCTION CURVE GUY WIRE ARRANGEMENT ...

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

2. TYPICAL OVERHEAD WIRE CONSTRUCTION - CURVE GUY WIRE ARRANGEMENT (ABANDONED WEST LEG OF WYE AT SIXTH AVENUE AND PINE STREET) - Yakima Valley Transportation Company Interurban Railroad, Trackage, Yakima, Yakima County, WA

Overhead Costs and Rates in the U.S. Defense Industrial Base. Volume 1

DTIC Science & Technology

1980-10-01

Manager rather than to establish rigidly defined cost accounting structures. The conclusions to be own from the analysis were that overhead costs have...specific costs which make up tho overhead account ; whether management is controlling them; whether these costs are "reasonable" and the external factors... cost accounting structures, . ..... ....... .... ... ............................... , , ,’" ’ .. -17- and since there is no one accounting definition of

23 CFR 140.907 - Overhead and indirect construction costs.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 23 Highways 1 2013-04-01 2013-04-01 false Overhead and indirect construction costs. 140.907 Section 140.907 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES... 18276, May 23, 1988] ...

23 CFR 140.907 - Overhead and indirect construction costs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 23 Highways 1 2014-04-01 2014-04-01 false Overhead and indirect construction costs. 140.907 Section 140.907 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES... 18276, May 23, 1988] ...

23 CFR 140.907 - Overhead and indirect construction costs.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 23 Highways 1 2011-04-01 2011-04-01 false Overhead and indirect construction costs. 140.907 Section 140.907 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PAYMENT PROCEDURES... 18276, May 23, 1988] ...

Effects of overhead work involving different heights and distances on neck and shoulder muscle activity.

PubMed

Shin, Seung-Je; Yoo, Won-Gyu

2015-06-05

Although overhead work is closely related to musculoskeletal disorders, it is difficult to avoid these postures in daily working conditions. In industrial tasks that require elevated arm postures above shoulder height, flexibility in the location of the task is necessary. This study investigated the sternocleidomastoid, upper trapezius, lower trapezius, and anterior deltoid, serratus anterior muscle activities during overhead work involving four different height and distance locations performed by healthy adult participants. Eighteen young male right-hand-dominant workers were recruited. The right upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and sternocleidomastoid muscle activities were measured under for overhead work condition (Location 1: overhead work with a height of 10 cm above the head of each subject and distance of 15 cm, Location 2: overhead work with a height of 10 cm above the head of each subject and distance of 30 cm, Location 3: overhead work with a height of 20 cm above the head of each subject and distance of 15 cm, Location 4: overhead work with a height of 20 cm above the head of each subject and distance of 30 cm). In Location 3, there was significantly higher neck extension range of motion compared to Location 1, Location 2 and Location 4. In Location 1, the activities of the upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and sternocleidomastoid muscles were significantly lower than those in Location 3 (p<0.05). In Location 2, the activities of the upper trapezius, lower trapezius, serratus anterior, anterior deltoid, and sternocleidomastoid muscles were significantly lower than those in Location 4 (p<0.05). In Location 1, there were significantly lower upper trapezius, lower trapezius, serratus anterior, and anterior deltoid muscle activities than in Location 2 (p<0.05). In Location 3, there were significantly lower upper trapezius, lower trapezius, serratus anterior, and anterior deltoid

How To Prepare Effective Overhead Projector Presentations: One Picture Is Worth a Thousand Words.

ERIC Educational Resources Information Center

National Audio-Visual Supply, East Rutherford, NJ.

Designed to help create effective presentations, this guide describes the basic techniques and provides hints for producing professional, attention-getting overhead transparencies in a step-by-step procedure format. Eight topics are addressed in the guide: (1) eight steps to a successful meeting presentation; (2) advantages of overhead projection;…

Growth, gas exchange, foliar nitrogen content, and water use of subirrigated and overhead irrigated Populus tremuloides Michx. seedlings

Treesearch

Anthony S. Davis; Matthew M. Aghai; Jeremiah R. Pinto; Kent G. Apostal

2011-01-01

Because limitations on water used by container nurseries has become commonplace, nursery growers will have to improve irrigation management. Subirrigation systems may provide an alternative to overhead irrigation systems by mitigating groundwater pollution and excessive water consumption. Seedling growth, gas exchange, leaf nitrogen (N) content, and water use were...

Overhead Projector Demonstrations: Some Ideas from the Past.

ERIC Educational Resources Information Center

Kolb, Doris

1987-01-01

Describes nine chemistry demonstrations that can be done using an overhead projector. Includes demonstrations on common ion effect, crystal formation from supersaturated solutions, making iron positive with nitric acid, optical activity, carbon dioxide in human breath, amphoteric hydroxides, the surface tension of mercury, and natural acid-base…

The role of handouts, note-taking and overhead transparencies in veterinary science lectures.

PubMed

McLennan, M W; Isaacs, G

2002-10-01

To study student and staff views of the role and use of handouts, note-taking and overhead transparencies in veterinary science lectures at the University of Queensland The Nominal Group Technique was used to help develop a questionnaire, which was completed by 351 students (a response rate of 84%) and 35 staff (76%) from the 5 years of the veterinary course. The data were analysed using the SAS statistical computer package. Staff and students held different views as to the frequency with which handouts should be used, their educational value, and whether they should be complete or partial. Fewer students than staff agreed that handouts discourage further reading in a subject. Almost all staff and students saw the central functions of note-taking to be provision of notes for subsequent revision and encoding information given by the lecturer. More students than staff however, considered that note-taking in lectures interferes with understanding. Staff and students held similar views as to the uses of overheads in lectures. Interestingly however, more staff than students agreed that overheads often contain too much information. Both students and staff saw the central role of note-taking as providing a set of good notes for revision. Generally students preferred that this information be provided in the form of partial or complete handouts, while staff preferred students to take notes and to read outside lectures. Surprisingly, more staff than students felt that overhead transparencies often contained too much information. Note-taking, handouts and overhead transparencies need to be linked in a coherent educational strategy to promote effective learning.

78 FR 68477 - Overhead and Gantry Cranes; Extension of the Office of Management and Budget's (OMB) Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-14

...] Overhead and Gantry Cranes; Extension of the Office of Management and Budget's (OMB) Approval of... requirements specified in the Standard on Overhead and Gantry Cranes (29 CFR 1910.179). DATES: Comments must be... information (29 U.S.C. 657). The paperwork provisions of the Standard on Overhead and Gantry Cranes specify...

Overhead Projector Demonstrations: A Classroom Demonstration of Aliphatic Substitution.

ERIC Educational Resources Information Center

Perina, Ivo; Mihanovic, Branka

1989-01-01

Presents a halogen substitution of an alkane using a compartmentalized Petri dish or Conway dish on an overhead projector. Provides methodology and several modifications for different reactions. Uses hexane, methyl orange, bromine, and silver nitrate. (MVL)

A fuzzy-logic antiswing controller for three-dimensional overhead cranes.

PubMed

Cho, Sung-Kun; Lee, Ho-Hoon

2002-04-01

In this paper, a new fuzzy antiswing control scheme is proposed for a three-dimensional overhead crane. The proposed control consists of a position servo control and a fuzzy-logic control. The position servo control is used to control crane position and rope length, and the fuzzy-logic control is used to suppress load swing. The proposed control guarantees not only prompt suppression of load swing but also accurate control of crane position and rope length for simultaneous travel, traverse, and hoisting motions of the crane. Furthermore, the proposed control provides practical gain tuning criteria for easy application. The effectiveness of the proposed control is shown by experiments with a three-dimensional prototype overhead crane.

Mechanics and pathomechanics in the overhead athlete.

PubMed

Kibler, W Ben; Wilkes, Trevor; Sciascia, Aaron

2013-10-01

Optimal performance of the overhead throwing task requires precise mechanics that involve coordinated kinetic and kinematic chains to develop, transfer, and regulate the forces the body needs to withstand the inherent demands of the task and to allow optimal performance. These chains have been evaluated and the basic components, called nodes, have been identified. Impaired performance and/or injury, the DTS, is associated with alterations in the mechanics that are called pathomechanics. They can occur at multiple locations throughout the kinetic chain. They must be evaluated and treated as part of the overall problem. Observational analysis of the mechanics and pathomechanics using the node analysis method can be useful in highlighting areas of alteration that can be evaluated for anatomic injury or altered physiology. The comprehensive kinetic chain examination can evaluate sites of kinetic chain breakage, and a detailed shoulder examination can assess joint internal derangement of altered physiology that may contribute to the pathomechanics. Treatment of the DTS should be comprehensive, directed toward restoring physiology and mechanics and optimizing anatomy. This maximizes the body’s ability to develop normal mechanics to accomplish the overhead throwing task. Copyright © 2013 Elsevier Inc. All rights reserved.

Gamma-ray dose from an overhead plume

DOE PAGES

McNaughton, Michael W.; Gillis, Jessica McDonnel; Ruedig, Elizabeth; ...

2017-05-01

Standard plume models can underestimate the gamma-ray dose when most of the radioactive material is above the heads of the receptors. Typically, a model is used to calculate the air concentration at the height of the receptor, and the dose is calculated by multiplying the air concentration by a concentration-to-dose conversion factor. Models indicate that if the plume is emitted from a stack during stable atmospheric conditions, the lower edges of the plume may not reach the ground, in which case both the ground-level concentration and the dose are usually reported as zero. However, in such cases, the dose frommore » overhead gamma-emitting radionuclides may be substantial. Such underestimates could impact decision making in emergency situations. The Monte Carlo N-Particle code, MCNP, was used to calculate the overhead shine dose and to compare with standard plume models. At long distances and during unstable atmospheric conditions, the MCNP results agree with the standard models. As a result, at short distances, where many models calculate zero, the true dose (as modeled by MCNP) can be estimated with simple equations.« less

Evaluation of high intensity sheeting for overhead highway signs.

DOT National Transportation Integrated Search

1974-01-01

The current practice in Virginia is to reflectorize and illuminate all overhead highway signs because of their important role in the safe and orderly flow of traffic. Reflectorization is obtained by using reflective sheeting as background and legend ...

31. DETAIL OF OVERHEAD TENSIONER DEVICE LOCATED ABOVE SOUTHERN DOOR ...

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

31. DETAIL OF OVERHEAD TENSIONER DEVICE LOCATED ABOVE SOUTHERN DOOR OF BUILDING 1. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

Detail, east side, north end, showing door and overhead rail ...

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

Detail, east side, north end, showing door and overhead rail for refrigeration room. - Fitzsimons General Hospital, Ice Plant, Southwest Corner of East I Avenue & North Thirteenth Street, Aurora, Adams County, CO

Human Factors Engineering Guidelines for Overhead Cranes

NASA Technical Reports Server (NTRS)

Chandler, Faith; Delgado, H. (Technical Monitor)

2001-01-01

This guideline provides standards for overhead crane cabs that can be applied to the design and modification of crane cabs to reduce the potential for human error due to design. This guideline serves as an aid during the development of a specification for purchases of cranes or for an engineering support request for crane design modification. It aids human factors engineers in evaluating existing cranes during accident investigations or safety reviews.

Overhead-Performance Tradeoffs in Distributed Wireless Networks

DTIC Science & Technology

2015-06-26

grew this fraction. See the tutorial for details and acronym definitions. Key Publication & Abstract • Gwanmo Ku and John MacLaren Walsh, Resource...tradeoffs. Key Publication & Abstract • Gwanmo Ku , Jie Ren, and John MacLaren Walsh, Computing the Rate Distortion Region for the CEO Problem with...IID. • Jie Ren, Bradford Boyle, Gwanmo Ku , Steven Weber, John MacLaren Walsh, Overhead Performance Tradeoffs A Resource Allocation Perspective, IEEE

Do overhead sports increase risk for rotator cuff tears in wheelchair users?

PubMed

Akbar, Michael; Brunner, Manuela; Ewerbeck, Volker; Wiedenhöfer, Bernd; Grieser, Thomas; Bruckner, Thomas; Loew, Markus; Raiss, Patric

2015-03-01

To analyze whether frequent overhead-sports activity increases the risk for rotator cuff disease in patients with spinal cord injuries (SCIs) who are wheelchair dependent. Cross-sectional study, risk analysis. Department of Orthopaedic Surgery, Trauma Surgery and Spinal Cord Injury. Patients (N=296) with SCI requiring the full-time use of a manual wheelchair were recruited for this study. The total population was divided into 2 groups (sports vs no sports), among them 103 patients playing overhead sports on a regular basis (at least 1-2 times/wk) and 193 patients involved in overhead sports less than once a week or in no sports activity at all. The mean age of the sports group was 49.1 years. The mean duration of wheelchair dependence was 26.5 years. The mean age of the no-sports group was 48 years. The mean duration of wheelchair dependence was 25.2 years. Each individual completed a questionnaire designed to identify overhead-sports activity on a regular basis and was asked about shoulder problems. Magnetic resonance imaging scans of both shoulders were performed in each patient and analyzed in a standardized fashion. None. Possible differences in continuous data between patients with and without rotator cuff tear were evaluated. The relative risk of suffering from a rotator cuff tear between patients playing overhead sports and those not playing overhead sports was calculated. One hundred three patients played overhead sports regularly and 193 did not. There was no difference between groups regarding age, sex, level of SCI, and duration of wheelchair dependence. The body mass index was significantly lower in the sports group than in the no-sports group (P<.0001). A rotator cuff tear was present in 75.7% of the patients in the sports group and in 36.3% of the patients in the no-sports group (P<.0001). Rotator cuff tears were symptomatic in 92.6% of the patients. The estimated risk increase for the sports group to develop rotator cuff tears was twice as high as

Interval Analysis Approach to Prototype the Robust Control of the Laboratory Overhead Crane

NASA Astrophysics Data System (ADS)

Smoczek, J.; Szpytko, J.; Hyla, P.

2014-07-01

The paper describes the software-hardware equipment and control-measurement solutions elaborated to prototype the laboratory scaled overhead crane control system. The novelty approach to crane dynamic system modelling and fuzzy robust control scheme design is presented. The iterative procedure for designing a fuzzy scheduling control scheme is developed based on the interval analysis of discrete-time closed-loop system characteristic polynomial coefficients in the presence of rope length and mass of a payload variation to select the minimum set of operating points corresponding to the midpoints of membership functions at which the linear controllers are determined through desired poles assignment. The experimental results obtained on the laboratory stand are presented.

Power System Reliability Assessment by Analysing Voltage Dips on the Blue Horizon Bay 22KV Overhead Line in the Nelson Mandela Bay Municipality

NASA Astrophysics Data System (ADS)

Lamour, B. G.; Harris, R. T.; Roberts, A. G.

2010-06-01

Power system reliability problems are very difficult to solve because the power systems are complex and geographically widely distributed and influenced by numerous unexpected events. It is therefore imperative to employ the most efficient optimization methods in solving the problems relating to reliability of the power system. This paper presents a reliability analysis and study of the power interruptions resulting from severe power outages in the Nelson Mandela Bay Municipality (NMBM), South Africa and includes an overview of the important factors influencing reliability, and methods to improve the reliability. The Blue Horizon Bay 22 kV overhead line, supplying a 6.6 kV residential sector has been selected. It has been established that 70% of the outages, recorded at the source, originate on this feeder.

32. VIEW FROM CATWALK SHOWING ROOF TRUSSES, OVERHEAD CRANE, AND ...

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

32. VIEW FROM CATWALK SHOWING ROOF TRUSSES, OVERHEAD CRANE, AND MISCELLANEOUS STOCK AND PATTERNS-LOOKING SOUTHWEST. - W. A. Young & Sons Foundry & Machine Shop, On Water Street along Monongahela River, Rices Landing, Greene County, PA

77 FR 53914 - Horton Automatics, Inc., a Subsidiary of Overhead Door Corporation Including On-Site Leased...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-04

...., a Subsidiary of Overhead Door Corporation Including On-Site Leased Workers From Remedy Intelligent..., including on-site leased workers from Remedy Intelligent Staffing, Corpus Christi, Texas. The workers are... Automatics, Inc., a subsidiary of Overhead Door Corporation, including on-site leased workers from Remedy...

Interior view of main section of milk barn. Opening overhead ...

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

Interior view of main section of milk barn. Opening overhead leads to attic crawl space. Camera is pointed SW. - Kosai Farm, Milk Barn, B Street north of Northwest Twenty-ninth Street, Auburn, King County, WA

12. Interior view, grain tanks (bins). Profile view of overhead ...

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

12. Interior view, grain tanks (bins). Profile view of overhead (fill) conveyor gallery bridge extending through tops of tanks just below roofs. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

23 CFR 140.907 - Overhead and indirect construction costs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... accounting principles; (2) The costs included in the distribution are limited to costs actually incurred by...), part 31, Contract Cost Principles and Procedures, relating to contracts with commercial organizations... 23 Highways 1 2010-04-01 2010-04-01 false Overhead and indirect construction costs. 140.907...

Compilation time analysis to minimize run-time overhead in preemptive scheduling on multiprocessors

NASA Astrophysics Data System (ADS)

Wauters, Piet; Lauwereins, Rudy; Peperstraete, J.

1994-10-01

This paper describes a scheduling method for hard real-time Digital Signal Processing (DSP) applications, implemented on a multi-processor. Due to the very high operating frequencies of DSP applications (typically hundreds of kHz) runtime overhead should be kept as small as possible. Because static scheduling introduces very little run-time overhead it is used as much as possible. Dynamic pre-emption of tasks is allowed if and only if it leads to better performance in spite of the extra run-time overhead. We essentially combine static scheduling with dynamic pre-emption using static priorities. Since we are dealing with hard real-time applications we must be able to guarantee at compile-time that all timing requirements will be satisfied at run-time. We will show that our method performs at least as good as any static scheduling method. It also reduces the total amount of dynamic pre-emptions compared with run time methods like deadline monotonic scheduling.

The applicability of high intensity sheeting on overhead highway signs.

DOT National Transportation Integrated Search

1975-01-01

This report summarizes (1) the findings of a research study on the applicability of using high intensity reflective sheeting on overhead signs, and (2) the implementation of recommendations evolving from these findings through elimination of the illu...

A Simple Polarimeter and Experiments Utilizing an Overhead Projector.

ERIC Educational Resources Information Center

Dorn, H. C.; And Others

1984-01-01

Although polarimeters that illustrate rotation of plane-polarized light by chiral solutions have been previously described, the polarimeter described in this paper has certain advantages when used in conjunction with an overhead projector. Instructions for constructing this polarimeter and its use in demonstrating the optical activity of sugars…

Application of vision measurements for modal analysis of wires for the purpose of overhead transmission lines monitoring

NASA Astrophysics Data System (ADS)

Mendrok, Krzysztof; Dworakowski, Ziemowit; Holak, Krzysztof; Kohut, Piotr

2017-05-01

Overhead transmission power lines are still one of the crucial elements of electro-energetic system. There are obvious advantages of using overhead transmission in the distribution of electricity. The amount of energy transported through a power line is determined by the distance between the wire and the ground or other objects placed beneath it (eg. trees). This distance is not fixed and depends on the overhang of the wire. This, in turn, is determined by many factors such as ambient temperature, humidity, precipitation, the value of current flowing through the wire. In order to optimize the wires electrical load, the monitoring of that overhang is required. One way to measure it is the non-contact measurement by vision system. It has the advantage, that using high-speed cameras respectively it also allows for vibration measurement and analysis of dynamic performance. That is very important while the wires are susceptible to the influence of wind, and the resulting vibrations interfere with the correct measurement of the overhang. The paper presents the results of vision measurements of the system vibrations and modal analysis carried out on their basis. The study was conducted on a specially made laboratory stand.

48 CFR 3452.216-71 - Negotiated overhead rates-fixed.

Code of Federal Regulations, 2010 CFR

2010-10-01

... acceptability of cost allocation methods shall be determined in accordance with part 31 of the Federal... different period, for which the rates apply, and (4) the specific items treated as direct costs or any changes in the items previously agreed to be direct costs. (e) Pending establishment of fixed overhead...

52. SOUTH PLANT PROCESS PIPING OVERHEAD RACK, WITH SHELL OIL ...

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

52. SOUTH PLANT PROCESS PIPING OVERHEAD RACK, WITH SHELL OIL COMPANY FACILITIES IN BACKGROUND. VIEW TO SOUTHEAST. - Rocky Mountain Arsenal, Bounded by Ninety-sixth Avenue & Fifty-sixth Avenue, Buckley Road, Quebec Street & Colorado Highway 2, Commerce City, Adams County, CO

View east from western edge of complex. Collapsed overhead conveyor ...

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

View east from western edge of complex. Collapsed overhead conveyor in foreground carried ganister down to the brickyard from crushing and grinding facility on the mountain. - Harbison-Walker Refractories Company, West end of Shirley Street, Mount Union, Huntingdon County, PA

Increased knee valgus alignment and moment during single-leg landing after overhead stroke as a potential risk factor of anterior cruciate ligament injury in badminton.

PubMed

Kimura, Yuka; Ishibashi, Yasuyuki; Tsuda, Eiichi; Yamamoto, Yuji; Hayashi, Yoshimitsu; Sato, Shuichi

2012-03-01

In badminton, knees opposite to the racket-hand side received anterior cruciate ligament (ACL) injuries during single-leg landing after overhead stroke. Most of them occurred in the backhand-side of the rear court. Comparing lower limb biomechanics during single-leg landing after overhead stroke between the forehand-side and backhand-side court may help explain the different injury rates depending on court position. The knee kinematics and kinetics during single-leg landing after overhead stroke following back-stepping were different between the forehand-side and backhand-side court. Controlled laboratory study. Hip, knee and ankle joint kinematic and knee kinetic data were collected for 17 right-handed female college badminton players using a 3-dimensional motion analysis system. Subjects performed single-left-legged landing after an overhead stroke following left and right back-stepping. The kinematic and kinetic data of the left lower extremities during landing were measured and compared between left and right back-steps. Hip flexion and abduction and knee valgus at the initial contact, hip and knee flexion and knee valgus at the maximum knee flexion and the maximum knee valgus moment were significantly larger for the left back-step than the right back-step (p<0.05). Significant differences in joint kinematics and kinetics of the lower extremity during single-leg landing after overhead stroke were observed between different back-step directions. Increased knee valgus angle and moment following back-stepping to the backhand-side might be related to the higher incidence of ACL injury during single-leg landing after overhead stroke.

84. GRINDING ROOM, LOOKING EAST. NOTE OVERHEAD BRIDGE CRANE RIDING ...

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

84. GRINDING ROOM, LOOKING EAST. NOTE OVERHEAD BRIDGE CRANE RIDING ON STEEL RAILS SUPPORTED BY WOODEN BEAMS AND CYCLONE CLASSIFIER IN CENTER. AT RIGHT IS TOP PORTION OF FLASH FLOTATION CELL. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

Oblique view to the northwest detailing four overhead rolling doors ...

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

Oblique view to the northwest detailing four overhead rolling doors on the northeast elevation - Over-the-Horizon Backscatter Radar Network, Mountain Home Air Force Operations Building, On Desert Street at 9th Avenue Mountain Home Air Force Base, Mountain Home, Elmore County, ID

13. Interior view, grain tanks (bins). Barrel view of overhead ...

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

13. Interior view, grain tanks (bins). Barrel view of overhead (fill) conveyor gallery bridge extending through tops of tanks just below roofs. Grain tripper straddles belt conveyor at mid-view. - Saint Anthony Elevator No. 3, 620 Malcom Avenue, Southeast, Minneapolis, Hennepin County, MN

142. OVERHEAD CRANES ON SOUTH WALL AND CEILING OF AGENA ...

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

142. OVERHEAD CRANES ON SOUTH WALL AND CEILING OF AGENA TRANSFER AREA SHELTER (117A), LSB (BLDG. 770). FORMERLY USED FOR VEHICLE TRANSFER. - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 West, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

Minimum retroreflectivity levels for overhead guide signs and street-name signs

DOT National Transportation Integrated Search

2003-12-01

In 1993, the Federal Highway Administration (FHWA) published research recommendations for minimum retroreflectivity (MR) levels for traffic signs. The recommendations included overhead signs, but not street-name signs. In revisions to the recommended...

The Use of the Overhead Projector in Teaching Composition.

ERIC Educational Resources Information Center

Bissex, Henry

The overhead projector, used as a controllable blackboard or bulletin board in the teaching of writing, extends the range of teaching techniques so that an instructor may (1) prepare, in advance, handwritten sheets of film--test questions, pupils' sentences, quotations, short poems--to be shown in any order or form; (2) use pictures, graphics, or…

A computer program to perform dynamic thermal analysis for bare overhead conductors during short-time overload conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shrestha, P.; Pham, K.

1995-12-31

Under emergency conditions, a bare overhead conductor can carry an increased amount of current that is well in excess of its normal rating. When there is this increase in current flow on a bare overhead conductor, the temperature does not rise instantaneously. but increases along a curve determined by the current, the conductor properties and the ambient conditions. The conductor temperature at the end of a short-time overload period must be restricted to its maximum design value. This paper presents a simplified approach in analyzing the dynamic performance for bare overhead conductors during short-time overload condition. A computer program wasmore » developed to calculate the short-time ratings for bare overhead conductors. The following parameters: current induced heating. solar load, convective/conductive cooling, radiative cooling, altitude, wind velocity and ampacity of the bare conductor were considered. Several sample graphical output lots are included with the paper.« less

Overhead throwing injuries of the shoulder and elbow.

PubMed

Anderson, Mark W; Alford, Bennett A

2010-11-01

Injuries to the shoulder and elbow are common in athletes involved in sporting activities that require overhead motion of the arm. An understanding of the forces involved in the throwing motion, the anatomic structures most at risk, and the magnetic resonance imaging appearances of the most common associated injuries can help to improve diagnostic accuracy when interpreting imaging studies in these patients. Copyright © 2010 Elsevier Inc. All rights reserved.

13. Emplacement no. 2, overhead view of counterweight well, showing ...

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

13. Emplacement no. 2, overhead view of counterweight well, showing channel for gun motor cable and bolt plates upon which base ring of gun carriage was mounted - Fort Wadsworth Battery Romeyn B. Ayers, South side of Ayers Road, Staten Island, Rosebank, Richmond County, NY

5. OVERHEAD VIEW OF GENE CAMP LOOKING SOUTH. GENE PUMP ...

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

5. OVERHEAD VIEW OF GENE CAMP LOOKING SOUTH. GENE PUMP PLANT IS AT CENTER WITH ADMINISTRATIVE COMPLEX IN FOREGROUND AND RESIDENTIAL AREA BEYOND PLANT. - Gene Pump Plant, South of Gene Wash Reservoir, 2 miles west of Whitsett Pump Plant, Parker Dam, San Bernardino County, CA

Crossing Phenomena in Overhead Line Equipment (OHLE) Structure in 3D Space Considering Soil-Structure Interaction

NASA Astrophysics Data System (ADS)

Ngamkhanong, Chayut; Kaewunruen, Sakdirat; Baniotopoulos, Charalampos; Papaelias, Mayorkinos

2017-10-01

Nowadays, the electric train becomes one of the efficient railway systems that are lighter, cleaner, quieter, cheaper and faster than a conventional train. Overhead line equipment (OHLE), which supplies electric power to the trains, is designed on the principle of overhead wires placed over the railway track. The OHLE is supported by mast structure which located at the lineside along the track. Normally, mast structure is a steel column or truss structure which supports the overhead wire carrying the power. Due to the running train and severe periodic force, such as an earthquake, in surrounding area may cause damage to the OHLE structure especially mast structure which leads to the failure of the electrical system. The mast structure needs to be discussed in order to resist the random forces. Due to the vibration effect, the natural frequencies of the structure are necessary. This is because when the external applied force occurs within a range of frequency of the structure, resonance effect can be expected which lead to the large oscillations and deflections. The natural frequency of a system is dependent only on the stiffness of the structure and the mass which participates with the structure, including self-weight. The modal analysis is used in order to calculate the mode shapes and natural frequencies of the mast structure during free vibration. A mast structure with varying rotational soil stiffness is used to observe the influence of soil-structure action. It is common to use finite element analysis to perform a modal analysis. This paper presents the fundamental mode shapes, natural frequencies and crossing phenomena of three-dimensional mast structure considering soil-structure interaction. The sensitivity of mode shapes to the variation of soil-structure interaction is discussed. The outcome of this study will improve the understanding of the fundamental dynamic behaviour of the mast structure which supports the OHLE. Moreover, this study will be a

Overhead View of Pathfinder Landing Site

NASA Technical Reports Server (NTRS)

1997-01-01

Planimetric (overhead view) map of the landing site, to a distance of 20 meters from the spacecraft. North is at the top in this and Plates 3-5. To produce this map, images were geometrically projected onto an assumed mean surface representing the ground. Features above the ground plane (primarily rocks) therefore appear displaced radially outward; the amount of distortion increases systematically with distance. The upper surfaces of the lander and rover also appear enlarged and displaced because of their height. Primary grid (white) is based on the Landing Site Cartographic (LSC) coordinate system, defined with X eastward, Y north, and Z up, and origin located at the mean ground surface immediately beneath the deployed position of the IMP camera gimbal center. Secondary ticks (cyan) are based on the Mars local level (LL) frame, which has X north, Y east, Z down, with origin in the center of the lander baseplate. Rover positions (including APXS measurements) are commonly reported in the LL frame. Yellow grid shows polar coordinates based on the LSC system. Cartographic image processing by U.S. Geological Survey.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

15. VIEW OF THE ORIGINAL 10TON OVERHEAD NILES TRAVELING CRANE. ...

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

15. VIEW OF THE ORIGINAL 10-TON OVERHEAD NILES TRAVELING CRANE. - Washington Water Power Company Post Falls Power Plant, Middle Channel Powerhouse & Dam, West of intersection of Spokane & Fourth Streets, Post Falls, Kootenai County, ID

Visual method for detecting critical damage in railway contact strips

NASA Astrophysics Data System (ADS)

Judek, S.; Skibicki, J.

2018-05-01

Ensuring an uninterrupted supply of power in the electric traction is vital for the safety of this important transport system. For this purpose, monitoring and diagnostics of the technical condition of the vehicle’s power supply elements are becoming increasingly common. This paper presents a new visual method for detecting contact strip damage, based on measurement and analysis of the movement of the overhead contact line (OCL) wire. A measurement system configuration with a 2D camera was proposed. The experimental method has shown that contact strips damage can be detected by transverse displacement signal analysis. It has been proven that the velocity signal numerically established on that basis has a comparable level in the case of identical damage, regardless of its location on the surface of the contact strip. The proposed method belongs to the group of contact-less measurements, so it does not require interference with the structure of the catenary network nor the mounting of sensors in its vicinity. Measurement of displacements of the contact wire in 2D space makes it possible to combine the functions of existing diagnostic stands assessing the correctness of the mean contact force control adjustment of the current collector with the elements of the contact strip diagnostics, which involves detecting their damage which may result in overhead contact line rupture.

19. Interior view showing flight simulator partition and rear overhead ...

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

19. Interior view showing flight simulator partition and rear overhead door, dock no. 493. View to south. - Offutt Air Force Base, Looking Glass Airborne Command Post, Nose Docks, On either side of Hangar Access Apron at Northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

Communication overhead on the Intel iPSC-860 hypercube

NASA Technical Reports Server (NTRS)

Bokhari, Shahid H.

1990-01-01

Experiments were conducted on the Intel iPSC-860 hypercube in order to evaluate the overhead of interprocessor communication. It is demonstrated that: (1) contrary to popular belief, the distance between two communicating processors has a significant impact on communication time, (2) edge contention can increase communication time by a factor of more than 7, and (3) node contention has no measurable impact.

Compensatory Muscle Activation During Unstable Overhead Squat Using a Water-filled Training Tube.

PubMed

Glass, Stephen C; Albert, Robert W

2018-05-01

Glass, SC, and Albert, RW. Compensatory muscle activation during unstable overhead squat using a water-filled training tube. J Strength Cond Res 32(5): 1230-1237, 2018-The purpose of this study was to assess compensatory muscle activation of core and support muscle during an overhead squat using a water-filled training tube. Eleven experienced weightlifting (age = 20.10 ± 0.99, mass 89.17 ± 6.88 kg) men completed 3, 30-second trials of an overhead squat using an 11.4 kg tube that was partially filled with water. A central valve allowed 3 conditions of water movement: 50% open, 100% open, and a stable(S), closed valve condition. Subjects completed 8-10 repetitions within each condition. Electromyographic (EMG) electrodes were placed over the belly of the vastus lateralis, deltoid, rectus abdominus, and paraspinal muscles and recorded during concentric and eccentric (ECC) phases. Integrated EMG were computed and converted to percent maximal voluntary contraction (%MVC). Compensatory activation was assessed using the natural log of the coefficient of variation of %MVC across repetitions. A 1-way repeated-measures analysis of variance across (phase, condition) was used. Significant compensatory muscle activation was seen in the deltoid muscle during ECC (100% open = 3.60 ± 0.50 > stable LogCV = 3.06 ± 0.45). In addition, paraspinal muscle activity was also more variable during the ECC phase (50% open LogCv = 3.28 ± 0.26 > stable = 2.77 ± 0.67). We conclude that the water-filled training tube induces compensatory muscle activation in the deltoid and paraspinal muscles during the ECC phase of the overhead squat.

Sonographic evaluation of the acromiohumeral distance in elite and recreational female overhead athletes.

PubMed

Maenhout, Annelies; van Cingel, Robert; De Mey, Kristof; Van Herzeele, Maarten; Dhooge, Famke; Cools, Ann

2013-05-01

To compare the acromiohumeral distance (AHD) and the change of this distance during abduction between the dominant and nondominant shoulders of female overhead athletes and to compare AHD between elite and recreational female athletes. : Case-control study. Laboratory, institutional. "Side" (dominant and nondominant), "group" (elite and recreational athletes), and "degree of abduction" (0, 45, and 60 degrees). Sixty-two female overhead athletes participated in this study: 29 elite handball players and 33 recreational overhead athletes of different sports disciplines (volleyball, water polo, squash, and badminton). Acromiohumeral distance was measured at 3 positions of abduction using ultrasound: at 0, 45, and 60 degrees of abduction. Acromiohumeral distance measurements showed good test-retest reliability (intraclass correlation coefficients between 0.88 and 0.92). In all overhead athletes, the AHD was significantly larger on the dominant side compared with the nondominant side, at all positions of abduction (mean difference = 0.94 ± 0.18 mm). Significant reduction of the AHD during abduction occurred relative to the initial size at 0 degree of abduction, at both sides. When comparing elite and recreational athletes, the AHD was significantly larger in elite athletes (mean difference = 0.92 ± 0.47 mm). Moreover, significantly less reduction occurred during the first degrees of abduction (0-45 degrees) in elite athletes (9.37% ± 2.17% reduction) compared with the recreational athletes (17.68% ± 2.03% reduction). The AHD is larger on the dominant side compared with the nondominant side and in elite female athletes compared with recreational female athletes. Moreover, less reduction of the AHD occurs in the elite athlete group during the first 45 degrees of abduction.

Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

NASA Astrophysics Data System (ADS)

Zheng, Li; Yi, Ruan

2009-11-01

Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

Characteristics and Needs for Overhead Guide Sign Illumination from Vehicular Headlamps

DOT National Transportation Integrated Search

1999-09-01

The Federal Highway Administration (FHWA) is concerned about changes in headlamp performance of the present fleet of vehicles in the US relative to its ability to properly illuminate traffic signs, especially overhead guide signs. If this is true, ov...

Launcher and Transparent Air Table for Use with Overhead Projector

ERIC Educational Resources Information Center

Carr, H. Y.; and others

1969-01-01

Describes an apparatus designed for quantitative demonstrations of collision experiments. The apparatus consists of a transparent air table and a launching device for projecting two objects simultaneously. It may be used with an overhead projector. The apparatus won third prize in Demonstration Lecture Apparatus in the A.A.P.T. Apparatus…

Dissolving Carboxylic Acids and Primary Amines on the Overhead Projector

ERIC Educational Resources Information Center

Solomon, Sally D.; Rutkowsky, Susan A.

2010-01-01

Liquid carboxylic acids (or primary amines) with limited solubility in water are dissolved by addition of aqueous sodium hydroxide (or hydrochloric acid) on the stage of an overhead projector using simple glassware and very small quantities of chemicals. This effective and colorful demonstration can be used to accompany discussions of the…

Efficiency of overhead ceiling lifts in reducing musculoskeletal injury among carers working in long-term care institutions.

PubMed

Alamgir, Hasanat; Yu, Shicheng; Fast, Catherine; Hennessy, Stephanie; Kidd, Catherine; Yassi, Annalee

2008-05-01

A longitudinal study was conducted in three long-term care facilities to evaluate the effectiveness and cost benefit of overhead lifts in reducing the risk of musculoskeletal injury among healthcare workers. Analysis of injury trends spanning 6 years before intervention (1996-2001) and 4 years after intervention (2002-2005) found a significant and sustained decrease in workers' compensation claims per number of beds and in working days lost per bed. The payback period was estimated under various assumptions and varied from 6.3 to 6.2 years if only direct claim-cost savings were included, and from 2.06 to 3.20 years when indirect savings were added. The significant reductions in injury rates and compensation claims support intervention with overhead ceiling lifts. A more comprehensive evaluation of such programmes should incorporate in the analysis important variables such as staffing ratios, job stresses, injury reporting systems and compensation policies during the study period.

75 FR 44288 - Overhead and Gantry Cranes; Extension of the Office of Management and Budget's (OMB) Approval of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-28

...] Overhead and Gantry Cranes; Extension of the Office of Management and Budget's (OMB) Approval of... requirements specified in the Standard on Overhead and Gantry Cranes (29 CFR 1910.179). DATES: Comments must be... requirements for: Marking the rated load of cranes; preparing certification records to verify the inspection of...

Shoulder External Rotation Fatigue and Scapular Muscle Activation and Kinematics in Overhead Athletes

PubMed Central

Joshi, Mithun; Thigpen, Charles A.; Bunn, Kevin; Karas, Spero G.; Padua, Darin A.

2011-01-01

Context: Glenohumeral external rotation (GH ER) muscle fatigue might contribute to shoulder injuries in overhead athletes. Few researchers have examined the effect of such fatigue on scapular kinematics and muscle activation during a functional movement pattern. Objective: To examine the effects of GH ER muscle fatigue on upper trapezius, lower trapezius, serratus anterior, and infraspinatus muscle activation and to examine scapular kinematics during a diagonal movement task in overhead athletes. Setting: Human performance research laboratory. Design: Descriptive laboratory study. Patients or Other Participants: Our study included 25 overhead athletes (15 men, 10 women; age = 20 ± 2 years, height = 180 ± 11 cm, mass = 80 ± 11 kg) without a history of shoulder pain on the dominant side. Interventions: We tested the healthy, dominant shoulder through a diagonal movement task before and after a fatiguing exercise involving low-resistance, high-repetition, prone GH ER from 0° to 75° with the shoulder in 90° of abduction. Main Outcome Measure(s): Surface electromyography was used to measure muscle activity for the upper trapezius, lower trapezius, serratus anterior, and infraspinatus. An electromyographic motion analysis system was used to assess 3-dimensional scapular kinematics. Repeated-measures analyses of variance (phase × condition) were used to test for differences. Results: We found a decrease in ascending-phase and descending-phase lower trapezius activity (F1,25 = 5.098, P = .03) and an increase in descending-phase infraspinatus activity (F1,25 = 5.534, P = .03) after the fatigue protocol. We also found an increase in scapular upward rotation (F1,24 = 3.7, P = .04) postfatigue. Conclusions: The GH ER muscle fatigue protocol used in this study caused decreased lower trapezius and increased infraspinatus activation concurrent with increased scapular upward rotation range of motion during the functional task. This highlights the interdependence of scapular

Feasibility of Floating Platform Systems for Wind Turbines: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Musial, W.; Butterfield, S.; Boone, A.

This paper provides a general technical description of several types of floating platforms for wind turbines. Platform topologies are classified into multiple- or single-turbine floaters and by mooring method. Platforms using catenary mooring systems are contrasted to vertical mooring systems and the advantages and disadvantages are discussed. Specific anchor types are described in detail. A rough cost comparison is performed for two different platform architectures using a generic 5-MW wind turbine. One platform is a Dutch study of a tri-floater platform using a catenary mooring system, and the other is a mono-column tension-leg platform developed at the National Renewable Energymore » Laboratory. Cost estimates showed that single unit production cost is $7.1 M for the Dutch tri-floater, and $6.5 M for the NREL TLP concept. However, value engineering, multiple unit series production, and platform/turbine system optimization can lower the unit platform costs to $4.26 M and $2.88 M, respectively, with significant potential to reduce cost further with system optimization. These foundation costs are within the range necessary to bring the cost of energy down to the DOE target range of $0.05/kWh for large-scale deployment of offshore floating wind turbines.« less

Electromyographic and kinetic comparison of the back squat and overhead squat.

PubMed

Aspe, Rodrigo R; Swinton, Paul A

2014-10-01

The purpose of this study was to compare muscle activity and kinetics during the back squat and overhead squat performed at 3 relative intensities (60, 75, and 90% 3 repetition maximum). Fourteen subjects (age, 26 ± 7 years; height, 182.5 ± 13.5 cm; body mass, 90.5 ± 17.5 kg) performed each exercise using a within-subjects crossover design. In addition, a selection of trunk isolation exercises were included to provide additional comparisons. Squats were performed on a force platform with electromyographic activity of the anterior deltoid, rectus abdominis (RA), external oblique (EO), erector spinae (ES), gluteus maximus, vastus lateralis, biceps femoris, and lateral gastrocnemius recorded throughout. The overhead squat demonstrated significantly greater (p ≤ 0.05) activity in the anterior trunk muscles (RA and EO) during the eccentric phase. However, the magnitudes of the differences were relatively small (approximately 2-7%). In contrast, the back squat displayed significantly greater (p ≤ 0.05) activity in the posterior aspect of the trunk ES and all lower-body muscles during the concentric phase. Kinetic comparisons revealed that significantly greater peak force (p ≤ 0.05) was developed during the back squat. Electromyographic comparisons between the trunk isolation exercises and squat variations demonstrated substantially greater anterior trunk activity during the isolation exercises, whereas the highest activity in the posterior aspect of the trunk was obtained during the squats (p ≤ 0.05). The results of the study do not support the hypothesis that the overhead squat provides a substantially greater stimulus for developing the trunk musculature compared with the back squat.

Overhead Projector Spectrum of Polymethine Dye: A Physical Chemistry Demonstration.

ERIC Educational Resources Information Center

Solomon, Sally; Hur, Chinhyu

1995-01-01

Encourages the incorporation into lecture of live experiments that can be predicted or interpreted with abstract models. A demonstration is described where the position of the predominant peak of 1,1'-diethyl-4,4'-cyanine iodide is measured in class using an overhead projector spectrometer, then predicted using the model of a particle in a…

Return to Preinjury Levels of Participation After Superior Labral Repair in Overhead Athletes: A Systematic Review

PubMed Central

Sciascia, Aaron; Myers, Natalie; Kibler, W. Ben; Uhl, Timothy L.

2015-01-01

Context Athletes often preoperatively weigh the risks and benefits of electing to undergo an orthopaedic procedure to repair damaged tissue. A common concern for athletes is being able to return to their maximum levels of competition after shoulder surgery, whereas clinicians struggle with the ability to provide a consistent prognosis of successful return to participation after surgery. The variation in study details and rates of return in the existing literature have not supplied clinicians with enough evidence to give overhead athletes adequate information regarding successful return to participation when deciding to undergo shoulder surgery. Objective To investigate the odds of overhead athletes returning to preinjury levels of participation after arthroscopic superior labral repair. Data Sources The CINAHL, MEDLINE, and SPORTDiscus databases from 1972 to 2013. Study Selection The criteria for article selection were (1) The study was written in English. (2) The study reported surgical repair of an isolated superior labral injury or a superior labral injury with soft tissue debridement. (3) The study involved overhead athletes equal to or less than 40 years of age. (4) The study assessed return to the preinjury level of participation. Data Extraction We critically reviewed articles for quality and bias and calculated and compared odds ratios for return to full participation for dichotomous populations or surgical procedures. Data Synthesis Of 215 identified articles, 11 were retained: 5 articles about isolated superior labral repair and 6 articles about labral repair with soft tissue debridement. The quality range was 11 to 17 (42% to 70%) of a possible 24 points. Odds ratios could be generated for 8 of 11 studies. Nonbaseball, nonoverhead, and nonthrowing athletes had a 2.3 to 5.8 times greater chance of full return to participation than overhead/throwing athletes after isolated superior labral repair. Similarly, nonoverhead athletes had 1.5 to 3.5 times greater

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN, CONVEYOR PLATFORM TRAM ...

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

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN, CONVEYOR PLATFORM TRAM TRESTLE, AND LOADING PLATFORM, LOOKING SOUTHWEST. THE HOLE IN THE ORE BIN FLOOR CAN BE SEEN, AND BALL MILL FOUNDATION AT LOWER LEFT CORNER. SEE CA-291-13 FOR IDENTICAL B&W NEGATIVE. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

30 CFR 77.203 - Use of material or equipment overhead; safeguards.

Code of Federal Regulations, 2010 CFR

2010-07-01

...; safeguards. 77.203 Section 77.203 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS, SURFACE COAL MINES AND SURFACE WORK AREAS...; safeguards. Where overhead repairs are being made at surface installations and equipment or material is taken...

Asbestos fiber release from the brake pads of overhead industrial cranes.

PubMed

Spencer, J W; Plisko, M J; Balzer, J L

1999-06-01

The purpose of this evaluation was to determine the actual contribution of airborne asbestos fibers to the work environment from the operation of overhead cranes and hoists that use asbestos composition brake pads. The evaluation was conducted in a working manufacturing facility. Other potential sources of asbestos were accounted for by visual inspection and background air monitoring. An overhead crane assembly comprised of a trolley and two hoists was employed for this study. The crane was operated for two consecutive eight-hour shifts representative of a heavy-duty cycle. Forty-four personal and area air samples were collected during the assessment. Asbestos fibers were analyzed for by phase contrast (NIOSH 7400), and transmission electron (NIOSH 7402) microscopy methods. Eight-hour time-weighted average (TWA) asbestos fiber concentrations ranged from < 0.005 to 0.011 fibers/cc (PCM), and < 0.0026 to < 0.0094 f/cc (TEM). There were no asbestos fibers detected by the TEM method from air samples collected during the operation of the cranes.

The Effect of Glenohumeral Internal-Rotation Deficit on Functional Rotator-Strength Ratio in Adolescent Overhead Athletes.

PubMed

Guney, Hande; Harput, Gulcan; Colakoglu, Filiz; Baltaci, Gul

2016-02-01

Glenohumeral (GH) internal-rotation deficit (GIRD) and lower eccentric external-rotator (ER) to concentric internal-rotator (IR) strength (ER:IR) ratio have been documented as risk factors for shoulder injuries, but there is no information on whether GIRD has an adverse effect on ER:IR ratio in adolescent overhead athletes. The aim of this study was to investigate the effects of GIRD on functional ER:IR ratio of the adolescent overhead athletes. Cross-sectional study. University research laboratory. 52 adolescent overhead athletes. To determine GIRD, the range of GH IR and ER motion was measured with a digital inclinometer. An isokinetic dynamometer was used to assess eccentric and concentric IR and ER muscle strength of the dominant and nondominant shoulders. One-way ANCOVA where sport type was set as a covariate was used to analyze the difference between athletes with and without GIRD. After standardized examinations of all shoulders, the athletes were divided into 2 groups, shoulders with (n = 27) and without GIRD (n = 25). There was a significant difference between groups in functional ER:IR ratio (P < .001). Athletes with GIRD had lower ER:IR ratio (0.56) than athletes without GIRD (0.83). As GIRD has an adverse effect on functional ratio of the shoulder-rotator muscles, interventions for adolescent overhead athletes should include improving GH-rotation range of motion.

TRANSLATION TO PORTUGUESE LANGUAGE AND CROSS-CULTURAL ADAPTATION OF THE MODIFIED ROWE SCORE FOR OVERHEAD ATHLETES

PubMed Central

Marcondes, Freddy Beretta; de Vasconcelos, Rodrigo Antunes; Marchetto, Adriano; de Andrade, André Luis Lugnani; Filho, Américo Zoppi; Etchebehere, Maurício

2015-01-01

Objetctive: Study was to translate and culturally adapt the modified Rowe score for overhead athletes. Methods: The translation and cultural adaptation process initially involved the stages of translation, synthesis, back-translation, and revision by the Translation Group. It was than created the pre-final version of the questionnaire, being the areas “function” and “pain” applied to 20 athletes that perform overhead movements and that suffered SLAP lesions in the dominant shoulder and the areas “active compression test and anterior apprehension test” and “motion” were applied to 15 health professionals. Results: During the translation process there were made little modifications in the questionnaire in order to adapt it to Brazilian culture, without changing the semantics and the idiomatic concept originally described. Conclusion: The questionnaire was easily understood by the subjects of the study, being possible to obtain the Brazilian version of the modified Rowe score for overhead athletes that underwent surgical treatment of the SLAP lesion. PMID:27047903

Eccentric and isometric shoulder rotator cuff strength testing using a hand-held dynamometer: reference values for overhead athletes.

PubMed

Cools, Ann M J; Vanderstukken, Fran; Vereecken, Frédéric; Duprez, Mattias; Heyman, Karel; Goethals, Nick; Johansson, Fredrik

2016-12-01

In order to provide science-based guidelines for injury prevention or return to play, regular measurement of isometric and eccentric internal (IR) and external (ER) rotator strength is warranted in overhead athletes. However, up to date, no normative database exists regarding these values, when measured with a hand-held dynamometer. Therefore, the purpose of the study was to provide a normative database on isometric and eccentric rotator cuff (RC) strength values in a sample of overhead athletes, and to discuss gender, age and sports differences. A HHD was used to measure RC strength in 201 overhead athletes between 18 and 50 years old from three different sports disciplines: tennis, volleyball and handball. Isometric as well as eccentric strength was measured in different shoulder positions. Outcome variables of interest were isometric ER and IR strength, eccentric ER strength, and intermuscular strength ratios ER/IR. Our results show significant side, gender and sports discipline differences in the isometric and eccentric RC strength. However, when normalized to body weight, gender differences often are absent. In general, strength differences are in favour of the dominant side, the male athletes and handball. Intermuscular ER/IR ratios showed gender, sports, and side differences. This normative database is necessary to help the clinician in the evaluation of RC strength in healthy and injured overhead athletes. In view of the preventive screening and return-to-play decisions in overhead athletes, normalization to body weight and calculating intermuscular ratios are key points in this evaluation. Diagnostic study, Level III.

Comparison of charged nanoparticle concentrations near busy roads and overhead high-voltage power lines.

PubMed

Jayaratne, E R; Ling, X; Morawska, L

2015-09-01

Overhead high-voltage power lines are known sources of corona ions. These ions rapidly attach to aerosols to form charged particles in the environment. Although the effect of ions and charged particles on human health is largely unknown, much attention has focused on the increasing exposure as a result of the expanding power network in urban residential areas. However, it is not widely known that a large number of charged particles in urban environments originate from motor vehicle emissions. In this study, for the first time, we compare the concentrations of charged nanoparticles near busy roads and overhead power lines. We show that large concentrations of both positive and negative charged nanoparticles are present near busy roadways and that these concentrations commonly exceed those under high-voltage power lines. We estimate that the concentration of charged nanoparticles found near two freeways carrying around 120 vehicles per minute exceeded the corresponding maximum concentrations under two corona-emitting overhead power lines by as much as a factor of 5. The difference was most pronounced when a significant fraction of traffic consisted of heavy-duty diesel vehicles which typically have high particle and charge emission rates. Copyright © 2015 Elsevier B.V. All rights reserved.

Using the Overhead Projector as a Light Source for Physics Demonstrations

ERIC Educational Resources Information Center

Mak, Se-Yuen

2006-01-01

This article illustrates how the overhead projector can be used as a light source in some peculiar ways for physics demonstrations. Five examples are included: (1) Study of chromatic aberration; (2) Making giant Newton's rings; (3) Comparison of the rate of heat absorption by different surfaces; (4) Demonstration of greenhouse effect; and (5)…

Asbestos fiber release from the brake pads of overhead industrial cranes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spencer, J.W.; Plisko, M.J.; Balzer, J.L.

The purpose of this evaluation was to determine the actual contribution of airborne asbestos fibers to the work environment from the operation of overhead cranes and hoists that use asbestos composition brake pads. The evaluation was conducted in a working manufacturing facility. Other potential sources of asbestos were accounted for by visual inspection and background air monitoring. An overhead crane assembly comprised of a trolley and two hoists was employed for this study. The crane was operated for two consecutive eight-hour shifts representative of a heavy-duty cycle. Forty-four personal and area air samples were collected during the assessment. Asbestos fibersmore » were analyzed for by phase contrast (NIOSH 7400), and transmission electron (NIOSH 7402) microscopy methods. Eight-hour time-weighted average (TWA) asbestos fiber concentrations ranges from <0.005 to 0.011 fibers/cc (PCM), and <0.0026 to <0.0094f/cc (TEM). There were no asbestos fibers detected by the TEM method from air samples collected during the operation of the cranes.« less

Prevention of shoulder injuries in overhead athletes: a science-based approach

PubMed Central

Cools, Ann M.; Johansson, Fredrik R.; Borms, Dorien; Maenhout, Annelies

2015-01-01

The shoulder is at high risk for injury during overhead sports, in particular in throwing or hitting activities, such as baseball, tennis, handball, and volleyball. In order to create a scientific basis for the prevention of recurrent injuries in overhead athletes, four steps need to be undertaken: (1) risk factors for injury and re-injury need to be defined; (2) established risk factors may be used as return-to-play criteria, with cut-off values based on normative databases; (3) these variables need to be measured using reliable, valid assessment tools and procedures; and (4) preventative training programs need to be designed and implemented into the training program of the athlete in order to prevent re-injury. In general, three risk factors have been defined that may form the basis for recommendations for the prevention of recurrent injury and return to play after injury: glenohumeral internal-rotation deficit (GIRD); rotator cuff strength, in particular the strength of the external rotators; and scapular dyskinesis, in particular scapular position and strength. PMID:26537804

U.S. Army Corps of Engineers: Building Overhead Costs into Projects and Customers’ Views on Information Provided

DTIC Science & Technology

2013-06-01

U.S. ARMY CORPS OF ENGINEERS Building Overhead Costs into Projects and Customers ’ Views on Information Provided...Overhead Costs into Projects and Customers ’ Views on Information Provided 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...and Customers ’ Views on Information Provided Why GAO Did This Study The Corps spends billions of dollars annually on projects in its Civil Works

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN. CONVEYOR PLATFORM,TRAM TRESTLE, ...

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

DETAIL OVERHEAD VIEW OF SECONDARY ORE BIN. CONVEYOR PLATFORM,TRAM TRESTLE, AND LOADING PLATFORM. LOOKING SOUTHWEST. THE HOLE IN THE ORE BIN FLOOR CAN BE SEEN, AND BALL MILL FOUNDATION AT LOWER LEFT CORNER. SEE CA-291-47(CT) FOR IDENTICAL COLOR TRANSPARENCY. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

Marangoni Flowers and the Evil Eye: Overhead Presentations of Marangoni Flow

ERIC Educational Resources Information Center

Mundell, Donald W.

2009-01-01

Intermolecular forces and surface tension gradients in solutions lead to remarkable flows, known as Marangoni flows, where liquid flows from a region of low surface tension towards higher surface tension. Details of these flows, not visible to the naked eye, are made visible on an overhead projector owing to variation in the index of refraction.…

High-tension electrical-arc-induced thermal burns caused by railway overhead cables.

PubMed

Koller, J

1991-10-01

Eleven patients with high-tension electrical-arc-induced thermal burns due to railway overhead cables were treated at the Bratislava Burn Department during a relatively short period of 18 months. All the injuries occurred by the same mechanism, that is persons climbing on top of railway carriages and approaching the 25,000 V a.c. overhead cables. All the burns were the result of an electrical arc passing externally to the body, with subsequent ignition of the victim's clothes. The cutaneous burns, ranging from 24 to 79 per cent of the BSA, were mostly deep partial to full skin thickness injuries. One patient died on day 5 postburn, the other survived. In spite of high-tension aetiology, no true electrical injuries appear to have occurred and no amputations were necessary. The pathophysiology and possible preventive measures are discussed. It must be stressed that arcing can be induced by an earthed object approaching, but not touching, a cable carrying a high voltage.

Reducing space overhead for independendent checkpointing

NASA Technical Reports Server (NTRS)

Wang, Yi-Min; Chung, Pi-Yu; Lin, In-Jen; Fuchs, W. Kent

1992-01-01

The main disadvantages of independent checkpointing are the possible domino effect and the associated storage space overhead for maintaining multiple checkpoints. In most previous work, it has been assumed that only the checkpoints older than the current global recovery line can be discarded. Here, we generalize a notion of recovery line to potential recovery line. Only the checkpoints belonging to at least one of the potential recovery lines cannot be discarded. By using the model of maximum-sized antichains on a partially ordered set, an efficient algorithm is developed for finding all non-discardable checkpoints, and we show that the number of non-discardable checkpoints cannot exceed N(N+1)/2, where N is the number of processors. Communication trace driven simulation for several hypercube programs is performed to show the benefit of the proposed algorithm for real applications.

A Novel Transient Fault Current Sensor Based on the PCB Rogowski Coil for Overhead Transmission Lines

PubMed Central

Liu, Yadong; Xie, Xiaolei; Hu, Yue; Qian, Yong; Sheng, Gehao; Jiang, Xiuchen

2016-01-01

The accurate detection of high-frequency transient fault currents in overhead transmission lines is the basis of malfunction detection and diagnosis. This paper proposes a novel differential winding printed circuit board (PCB) Rogowski coil for the detection of transient fault currents in overhead transmission lines. The interference mechanism of the sensor surrounding the overhead transmission line is analyzed and the guideline for the interference elimination is obtained, and then a differential winding printed circuit board (PCB) Rogowski coil is proposed, where the branch and return line of the PCB coil were designed to be strictly symmetrical by using a joining structure of two semi-rings and collinear twisted pair differential windings in each semi-ring. A serial test is conducted, including the frequency response, linearity, and anti-interference performance as well as a comparison with commercial sensors. Results show that a PCB Rogowski coil has good linearity and resistance to various external magnetic field interferences, thus enabling it to be widely applied in fault-current-collecting devices. PMID:27213402

The Use of Probability Theory as a Basis for Planning and Controlling Overhead Costs in Education and Industry. Final Report.

ERIC Educational Resources Information Center

Vinson, R. B.

In this report, the author suggests changes in the treatment of overhead costs by hypothesizing that "the effectiveness of standard costing in planning and controlling overhead costs can be increased through the use of probability theory and associated statistical techniques." To test the hypothesis, the author (1) presents an overview of the…

Débridement of Small Partial-thickness Rotator Cuff Tears in Elite Overhead Throwers

PubMed Central

Dugas, Jeffrey R.; Cain, E. Lyle; McMichael, Christopher S.; Andrews, James R.

2008-01-01

Elite overhead throwing athletes with rotator cuff tears represent a unique group of patients with an ultimate goal of returning to their previous level of competition. We hypothesized débridement of small partial-thickness rotator cuff tears would return the majority of elite overhead throwing athletes to their previous level of competition. Preoperative and intraoperative findings on 82 professional pitchers who had undergone débridement of partial-thickness rotator cuff tears were evaluated using our database. We obtained return to play data on 67 of the 82 players (82%); 51 (76%) were able to return to competitive pitching at the professional level and 37 (55%) were able to return to the same or higher level of competition. Of the 67 patients, 34 pitchers returned a questionnaire with a minimum followup of 18 months (mean 38 months; range 18 to 59 months). SF-12 scores were above average with a mean PSF-12 and MSF-12 of 55.04 and 56.49 respectively. An Athletic Shoulder Outcome Rating Scale score of greater than 60 was found in 76.5% of pitchers. Débridement of small partial-thickness rotator cuff tears allowed a majority of elite overhead throwing athletes to return to competitive pitching, however, returning to their previous level of competition remains a challenge for many of these players. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18264849

OMB revises overhead rules

NASA Astrophysics Data System (ADS)

Katzoff, Judith A.

After pressure from university administrators, the Office of Management and Budget (OMB) has issued a new plan for saving money on research overhead costs, in place of a controversial proposal that was originally published in February 1986 (Eos, May 20, 1986, p. 481). The agency made the new plan more palatable to administrators and faculty by choosing to cap the rate of reimbursement for the activity that researchers say they find among the most difficult to document: the time they spend on administration of federally sponsored grants and contracts. An amendment to a bill signed by President Ronald Reagan on July 2 might force OMB to make additional concessions to colleges and universities.How much money the federal government would save under this policy is a matter of dispute. The agency's revisions to OMB Circular A-21, “Cost Principles for Educational Institutions,” call for fixing the reimbursement rate at 3% of modified total direct costs for departmental administration work done by “department heads, directors of divisions faculty, and professional staff.” The 3% figure represents about half of the current national average rate of reimbursement for these costs and would lead to federal government savings of $100 million a year, according to OMB.

Self-actuating grapple automatically engages and releases loads from overhead cranes

NASA Technical Reports Server (NTRS)

Froehlich, J. A.; Karastas, G. A.

1966-01-01

Two-piece grapple mechanism consisting of a lift knob secured to the load and a grapple member connected to the crane or lift automatically disengages the load from the overhead lifting device when the load contacts the ground. The key feature is the sliding collar under the lift knob which enables the grapple latch to be stripped off over the lift knob.

Scapular Bracing and Alteration of Posture and Muscle Activity in Overhead Athletes With Poor Posture

PubMed Central

Cole, Ashley K; McGrath, Melanie L; Harrington, Shana E; Padua, Darin A; Rucinski, Terri J; Prentice, William E

2013-01-01

Context Overhead athletes commonly have poor posture. Commercial braces are used to improve posture and function, but few researchers have examined the effects of shoulder or scapular bracing on posture and scapular muscle activity. Objective To examine whether a scapular stabilization brace acutely alters posture and scapular muscle activity in healthy overhead athletes with forward-head, rounded-shoulder posture (FHRSP). Design Randomized controlled clinical trial. Setting Applied biomechanics laboratory. Patients or Other Participants Thirty-eight healthy overhead athletes with FHRSP. Intervention(s) Participants were assigned randomly to 2 groups: compression shirt with no strap tension (S) and compression shirt with the straps fully tensioned (S + T). Posture was measured using lateral-view photography with retroreflective markers. Electromyography (EMG) of the upper trapezius (UT), middle trapezius (MT), lower trapezius (LT), and serratus anterior (SA) in the dominant upper extremity was measured during 4 exercises (scapular punches, W's, Y's, T's) and 2 glenohumeral motions (forward flexion, shoulder extension). Posture and exercise EMG measurements were taken with and without the brace applied. Main Outcome Measure(s) Head and shoulder angles were measured from lateral-view digital photographs. Normalized surface EMG was used to assess mean muscle activation of the UT, MT, LT, and SA. Results Application of the brace decreased forward shoulder angle in the S + T condition. Brace application also caused a small increase in LT EMG during forward flexion and Y's and a small decrease in UT and MT EMG during shoulder extension. Brace application in the S + T group decreased UT EMG during W's, whereas UT EMG increased during W's in the S group. Conclusions Application of the scapular brace improved shoulder posture and scapular muscle activity, but EMG changes were highly variable. Use of a scapular brace might improve shoulder posture and muscle activity in

Exercise prescription for overhead athletes with shoulder pathology: a systematic review with best evidence synthesis.

PubMed

Wright, Alexis A; Hegedus, Eric J; Tarara, Daniel T; Ray, Samantha C; Dischiavi, Steven L

2018-02-01

To produce a best evidence synthesis of exercise prescription used when treating shoulder pathology in the overhead athlete. A systematic review of exercises used in overhead athletes including case studies and clinical commentaries. MEDLINE, PubMed, SPORTDiscus and CINAHL from database inception through July 8, 2016. We examined data from randomised controlled trials and prospective cohort (level I-IV evidence) studies that addressed exercise intervention in the rehabilitation of the overhead athlete with shoulder pathology. Case studies and clinical commentaries (level V evidence) were examined to account for expert opinion-based research. Data were combined using best evidence synthesis and graded (A-F) recommendations (Centre for Evidence-Based Medicine). There were 33 unique exercises in six level I-IV studies that met our inclusion criteria. Most exercises were single-plane, upper extremity exercises performed below 90 o of elevation. There were 102 unique exercises in 33 level V studies that met our inclusion criteria. These exercises emphasised plyometrics, kinetic chain and sport-specific training. Overall, evidence for exercise interventions in overhead athletes with shoulder pathology is dominated by expert opinion (grade D). There is great variability between exercise approaches suggested by experts and those investigated in research studies and the overall level of evidence is low. The strongest available evidence (level B) supports the use of single-plane, open chain upper extremity exercises performed below 90° of elevation and closed chain upper extremity exercises. Clinical expert pieces support a more advanced, global treatment approach consistent with the complex, multidimensional nature of sport. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Study of a phase-to-ground fault on a 400 kV overhead transmission line

NASA Astrophysics Data System (ADS)

Iagăr, A.; Popa, G. N.; Diniş, C. M.

2018-01-01

Power utilities need to supply their consumers at high power quality level. Because the faults that occur on High-Voltage and Extra-High-Voltage transmission lines can cause serious damages in underlying transmission and distribution systems, it is important to examine each fault in detail. In this work we studied a phase-to-ground fault (on phase 1) of 400 kV overhead transmission line Mintia-Arad. Indactic® 650 fault analyzing system was used to record the history of the fault. Signals (analog and digital) recorded by Indactic® 650 were visualized and analyzed by Focus program. Summary of fault report allowed evaluation of behavior of control and protection equipment and determination of cause and location of the fault.

The impact of overhead lines for employees with stents

NASA Astrophysics Data System (ADS)

Syrek, P.; Skowron, M.

2017-05-01

The aim of article is to discuss interaction between stents implanted in the body of worker and harmonic magnetic field in the vicinity of electric wires. In last decades, a growing proportion of people has any devices implanted, to list: cardiac pacemakers, cardioverter - defibrillators. Recommendations of International Commision on Non-ionizing Radiation Protection (ICNIRP), and resctrictions imposed in different states, may exlude specific individuals from their duties. The autors focused on the situation, when the employee with stent, works in the immediate vicinity of overhead electric wires, cleaning with dry ice the electric insulators.

49 CFR 214.515 - Overhead covers for existing on-track roadway maintenance machines.

Code of Federal Regulations, 2011 CFR

2011-10-01

... maintenance machines. 214.515 Section 214.515 Transportation Other Regulations Relating to Transportation... Roadway Maintenance Machines and Hi-Rail Vehicles § 214.515 Overhead covers for existing on-track roadway maintenance machines. (a) For those existing on-track roadway maintenance machines either currently or...

Activity of Shoulder Stabilizers and Prime Movers During an Unstable Overhead Press.

PubMed

Williams, Martin R; Hendricks, Dustin S; Dannen, Michael J; Arnold, Andrea M; Lawrence, Michael A

2018-06-08

Williams, MR Jr, Hendricks, DS, Dannen, MJ, Arnold, AM, and Lawrence, MA. Activity of shoulder stabilizers and prime movers during an unstable overhead press. J Strength Cond Res XX(X): 000-000, 2018-Overhead reaching is a common movement that relies heavily on muscles for dynamic stability. Stabilizer muscle activation increased during squatting and bench pressing with an unstable load, but the overhead press (OHP) has yet to be examined. The purpose of this study is to compare muscle activity of the shoulder stabilizers and prime movers and excursions of the center of pressure (CoP) during the OHP in 2 unstable and one stable conditions. Twelve men (aged 25.3 ± 2.7 years, mass: 91.5 ± 8.4 kg, height: 1.81 ± 0.06 m) pressed 50% of their 1 repetition maximum for 10 repetitions over 3 conditions: a straight stable barbell (SS), a straight unstable (SU) barbell with kettlebells suspend by elastic bands, and an unstable Earthquake (EU) bar with kettlebells suspended by elastic bands. Activity of the shoulder stabilizers and prime movers were measured via surface and indwelling electromyography. Center of pressure excursion of the right foot was also measured. A multivariate analysis was used to determine significant differences between conditions. Pressing with the EQ increased activation of the biceps brachii, erector spinae, latissimus dorsi, pectoralis major, rectus abdominus, rhomboids, and serratus anterior over the SS condition, whereas only the SU condition increased activation in the erector spinae and latissimus dorsi muscles. The EQ condition produced greater CoP excursion (35.3 ± 7.9% foot length) compared with the SU (28.0 ± 7.2% foot length) and SS (22.2 ± 6.3% foot length) conditions. Therefore, the EU condition may be an effective exercise to activate scapular stabilizers.

Uptake and Accumulation of Pharmaceuticals in Overhead- and Surface-Irrigated Greenhouse Lettuce.

PubMed

Bhalsod, Gemini D; Chuang, Ya-Hui; Jeon, Sangho; Gui, Wenjun; Li, Hui; Ryser, Elliot T; Guber, Andrey K; Zhang, Wei

2018-01-31

Understanding the uptake and accumulation of pharmaceuticals in vegetables under typical irrigation practices is critical to risk assessment of crop irrigation with reclaimed water. This study investigated the pharmaceutical residues in greenhouse lettuce under overhead and soil-surface irrigations using pharmaceutical-contaminated water. Compared to soil-surface irrigation, overhead irrigation substantially increased the pharmaceutical residues in lettuce shoots. The increased residue levels persisted even after washing for trimethoprim, monensin sodium, and tylosin, indicating their strong sorption to the shoots. The postwashing concentrations in fresh shoots varied from 0.05 ± 0.04 μg/kg for sulfadiazine to 345 ± 139 μg/kg for carbamazepine. Root concentration factors ranged from 0.04 ± 0.14 for tylosin to 19.2 ± 15.7 for sulfamethoxazole. Translocation factors in surface-irrigated lettuce were low for sulfamethoxalzole, trimethoprim, monensin sodium, and tylosin (0.07-0.15), but high for caffeine (4.28 ± 3.01) and carbamazepine (8.15 ± 2.87). Carbamazepine was persistent in soil and hyperaccumulated in shoots.

Adaptive output-based command shaping for sway control of a 3D overhead crane with payload hoisting and wind disturbance

NASA Astrophysics Data System (ADS)

Abdullahi, Auwalu M.; Mohamed, Z.; Selamat, H.; Pota, Hemanshu R.; Zainal Abidin, M. S.; Ismail, F. S.; Haruna, A.

2018-01-01

Payload hoisting and wind disturbance during crane operations are among the challenging factors that affect a payload sway and thus, affect the crane's performance. This paper proposes a new online adaptive output-based command shaping (AOCS) technique for an effective payload sway reduction of an overhead crane under the influence of those effects. This technique enhances the previously developed output-based command shaping (OCS) which was effective only for a fixed system and without external disturbances. Unlike the conventional input shaping design technique which requires the system's natural frequency and damping ratio, the proposed technique is designed by using the output signal and thus, an online adaptive algorithm can be formulated. To test the effectiveness of the AOCS, experiments are carried out using a laboratory overhead crane with a payload hoisting in the presence of wind, and with different payloads. The superiority of the method is confirmed by 82% and 29% reductions in the overall sway and the maximum transient sway respectively, when compared to the OCS, and two robust input shapers namely Zero Vibration Derivative-Derivative and Extra-Insensitive shapers. Furthermore, the method demonstrates a uniform crane's performance under all conditions. It is envisaged that the proposed method can be very useful in designing an effective controller for a crane system with an unknown payload and under the influence of external disturbances.

Relationship Between the Electromagnetic Wave Energy Coupled by Overhead Lines and the Radiation Source Current Explored in the Laboratory

NASA Astrophysics Data System (ADS)

Li, Xiangchao; Wan, Zhicheng

2018-04-01

In order to solve the damage and interference problems to the electronic devices, which are induced by overvoltage excited by the coupling process between lightning electromagnetic wave and overhead lines, the lightning channel is set to be equivalent to a radiant wire antenna. Based on the integration model of lightning return stroke channel, transmission line, and ground, we take advantage of the derived formula gotten from the transmission line model. By combing the theoretical and experimental methods, we conduct a comparative analysis on the coupling process between natural/simulated lightning and overhead line. Besides, we also calculate the amplitude and energy of overvoltage, which is caused by the coupling process between lightning electromagnetic wave and overhead lines. Upon these experimental results, we can draw several conclusions as follows: when the amplitude of the lightning current in the channel is between 5 kA and 41 kA, it takes on an excellent linear relation between the amplitude of overvoltage and the magnitude of the lightning current, the relation between coupling energy and magnitude of the lightning current takes on an exponential trend. When lightning wave transmits on the transmission lines, the high-order mode will be excited. Through analysis on the high-order mode's characteristics, we find that the theoretical analysis is consistent with the experimental results, which has a certain reference value to the protection on overhead lines.

Dynamics and Embedded Internet of Things Input Shaping Control for Overhead Cranes Transporting Multibody Payloads.

PubMed

Peláez, Gerardo; Vaugan, Joshua; Izquierdo, Pablo; Rubio, Higinio; García-Prada, Juan Carlos

2018-06-04

Input shaping is an Optimal Control feedforward strategy whose ability to define how and when a flexible dynamical system defined by Ordinary Differential Equations (ODEs) and computer controlled would move into its operative space, without command induced unwanted dynamics, has been exhaustively demonstrated. This work examines the issue of Embedded Internet of Things (IoT) Input Shaping with regard to real time control of multibody oscillatory systems whose dynamics are better described by differential algebraic equations (DAEs). An overhead crane hanging a double link multibody payload has been appointed as a benchmark case; it is a multibody, multimode system. This might be worst scenario to implement Input Shaping. The reasons can be found in the wide array of constraints that arise. Firstly, the reliability of the multibody model was tested on a Functional Mock-Up Interface (FMI) with the two link payload suspended from the trolley by comparing the experimental video tapping signals in time domain faced with the signals extracted from the multibody model. The FFTs of the simulated and the experimental signal contain the same frequency harmonics only with somewhat different power due to the real world light damping in the joints. The application of this approach may be extended to other cases i.e., the usefulness of mobile hydraulic cranes is limited because the payload is supported by an overhead cable under tension that allows oscillation to occur during crane motion. If the payload size is not negligible small when compared with the cable length may introduce an additional oscillatory mode that creates a multibody double pendulum. To give the insight into the double pendulum dynamics by Lagrangian methods two slender rods as payloads are analyzed dealing with the overhead crane and a composite revolute-revolute joint is proposed to model the cable of the hydraulic crane, both assumptions facilitates an affordable analysis. This allows developing a general

High sensitive FBG load cell for icing of overhead transmission lines

NASA Astrophysics Data System (ADS)

Mao, Naiqiang; Ma, Guoming; Li, Chengrong; Li, Yabo; Shi, Cheng; Du, Yue

2017-04-01

Heavy ice coating of overhead transmission lines created the serious threat on the safe operation of power grid. The measurement of conductor icing had been an effective and reliable methods to prevent potential risks, such as conductor breakage, insulator flashover and tower collapse. Because of the advantages of immunity to electromagnetic interference and no demand for power supply in site, the optical load cell has been widely applied in monitoring the ice coating of overhead transmission lines. In this paper, we have adopted the shearing structure with additional grooves as elastic element of load cell to detect the eccentric load. Then, two welding package fiber Bragg gratings (FBGs) were mounted onto the grooves of elastic element with a direction deviation of 90° to eliminate temperature effects on strain measurement without extra FBG. After that, to avoid the occurrence of load cell breakage in heavy load measurement, the protection part has been proposed and added to the elastic element. The results of tension experiments indicate that the resolution of the load cell is 7.78 N in the conventional measuring range (0-10 kN). And in addition, the load cell proposed in this paper also has a good performance in actual experiment in which the load and temperature change simultaneously.

The Locus of the Focus of a Rolling Parabola

ERIC Educational Resources Information Center

Agarwal, Anurag; Marengo, James

2010-01-01

The catenary is usually introduced as the shape assumed by a hanging flexible cable. This is a "physical" description of a catenary. In this article we give a "geometrical" description of a catenary. Specifically we show that the catenary is the locus of the focus of a certain parabola as it rolls on the x-axis.

GAMMA FACILITY, TRA611, INTERIOR. WITH HELP OF OVERHEAD CHAIN AND ...

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

GAMMA FACILITY, TRA-611, INTERIOR. WITH HELP OF OVERHEAD CHAIN AND HOOK, SCIENTIST GUIDES METAL CONTAINER (HOLDING POTATOES, IN THIS CASE) INTO RECEIVING "COLUMN" IN THE GAMMA CANAL. NOTE OTHER COLUMNS AT RIGHT AND LEFT WALLS OF CANAL. NEAR BOTTOM OF CANAL, SPENT MTR FUEL WILL IRRADIATE POTATOES. INL NEGATIVE NO. 56-439. R.G. Larsen, Photographer, 2/8/1956 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

An Insight on Right of Way and its Cost for Power Transmission Cable and Conventional Overhead Transmission Lines

NASA Astrophysics Data System (ADS)

Khandelwal, P.; Pachori, A.; Khandelwal, T.

2013-12-01

This paper provides the complete information related to Right of Way (RoW) for the construction of new power transmission line (TL) in terms of present cost for overhead transmission line and underground XLPE transmission cable. The former part of the paper describes the general procedure and rules for acquisition of land for RoW by transmission asset owner (TAO) while in the later part the cost associated to acquire RoW and its impact on the cost of adjacent land have been detailed. It also discusses the actual dismantling cost including the cost of waste metal what TAO get after completion of lifecycle of TL due to increase in metal prices. In this paper cost of RoW after completion of lifecycle of TL is also highlighted. This paper compares the cost of RoW for overhead transmission line and underground XLPE transmission cable for construction of new TL. Also for old transmission infrastructure cost of RoW for change from overhead transmission line to underground XLPE transmission cable is detailed by application of replacement model.

Analysis of Operating Modes of Stand-Alone Series Controller of Power Flows for Overhead Power Transmission Lines

NASA Astrophysics Data System (ADS)

Astashev, M. G.; Panfilov, D. I.; Seregin, D. A.; Chernyshev, A. A.

2017-12-01

The features of using the bridge voltage inverter in small-size stand-alone series controllers of power flows (PFSC) for overhead power transmission lines (OPTL) are examined. The basic processes in the converter during transient and steady state modes were analyzed. The basic relations for calculating the electromagnetic processes taking into account the energy loss in the circuit and without it were received. A simulation model is proposed of a converter that makes it possible to study its operating modes during the formation of reactance introduced into the overhead power transmission line. The results of simulation of operating modes of the PFSC are presented.

Use of high intensity reflective sheeting in lieu of external lighting of overhead roadway signs.

DOT National Transportation Integrated Search

2013-06-01

Effective highway signing is an important component of driver decision making, comfort, and : safety. Like many agencies across the country, overhead sign lighting has been used by the Florida : Department of Transportation (FDOT) to improve visibili...

Measurement and Modeling of Job Stress of Electric Overhead Traveling Crane Operators

PubMed Central

Krishna, Obilisetty B.; Maiti, Jhareswar; Ray, Pradip K.; Samanta, Biswajit; Mandal, Saptarshi; Sarkar, Sobhan

2015-01-01

Background In this study, the measurement of job stress of electric overhead traveling crane operators and quantification of the effects of operator and workplace characteristics on job stress were assessed. Methods Job stress was measured on five subscales: employee empowerment, role overload, role ambiguity, rule violation, and job hazard. The characteristics of the operators that were studied were age, experience, body weight, and body height. The workplace characteristics considered were hours of exposure, cabin type, cabin feature, and crane height. The proposed methodology included administration of a questionnaire survey to 76 electric overhead traveling crane operators followed by analysis using analysis of variance and a classification and regression tree. Results The key findings were: (1) the five subscales can be used to measure job stress; (2) employee empowerment was the most significant factor followed by the role overload; (3) workplace characteristics contributed more towards job stress than operator's characteristics; and (4) of the workplace characteristics, crane height was the major contributor. Conclusion The issues related to crane height and cabin feature can be fixed by providing engineering or foolproof solutions than relying on interventions related to the demographic factors. PMID:26929839

On the implementation of an auxiliary pantograph for speed increase on existing lines

NASA Astrophysics Data System (ADS)

Liu, Zhendong; Jönsson, Per-Anders; Stichel, Sebastian; Rønnquist, Anders

2016-08-01

The contact between pantograph and catenary at high speeds suffers from high dynamic contact force variation due to stiffness variations and wave propagation. To increase operational speed on an existing catenary system, especially for soft catenary systems, technical upgrading is usually necessary. Therefore, it is desirable to explore a more practical and cost-saving method to increase the operational speed. Based on a 3D pantograph-catenary finite element model, a parametric study on two-pantograph operation with short spacing distances at high speeds shows that, although the performance of the leading pantograph gets deteriorated, the trailing pantograph feels an improvement if pantographs are spaced at a proper distance. Then, two main positive effects, which can cause the improvement, are addressed. Based on a discussion on wear mechanisms, this paper suggests to use the leading pantograph as an auxiliary pantograph, which does not conduct any electric current, to minimise additional wear caused by the leading pantograph. To help implementation and achieve further improvement under this working condition, this paper investigates cases with optimised uplift force on the leading pantograph and with system parameter deviations. The results show that the two positive effects still remain even with some system parameter deviations. About 30% of speed increase should be possibly achieved still sustaining a good dynamic performance with help of the optimised uplift force.

76 FR 10476 - Special Conditions: Boeing Model 787-8 Airplane; Overhead Crew-Rest Compartment

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-25

...\\ in interior volume, the design must ensure the ability to contain a fire likely to occur within the... or unusual design features associated with installation of an overhead crew-rest (OCR) compartment... this design feature. These special conditions contain the additional safety standards that the...

Risk factors for, and prevention of, shoulder injuries in overhead sports: a systematic review with best-evidence synthesis.

PubMed

Asker, Martin; Brooke, Hannah L; Waldén, Markus; Tranaeus, Ulrika; Johansson, Fredrik; Skillgate, Eva; Holm, Lena W

2018-03-26

To assess the evidence for risk factors and prevention measures for shoulder injuries in overhead sports. Systematic review with best-evidence synthesis. Medline (Ovid), PubMed (complementary search), Embase (Elsevier), Cochrane (Wiley), SPORTDiscus (Ebsco) and Web of Science Core Collection (Thomson Reuters), from 1 January 1990 to 15 May 2017. Randomised controlled trials, cohort studies and case-control studies on risk factors or prevention measures for shoulder injuries in overhead sports. The eligible studies were quality assessed using the Scottish Intercollegiate Guidelines Network criteria. Of 4778 studies identified, 38 were eligible for quality review and 17 met the quality criteria to be included in the evidence synthesis. One additional quality study presented a shoulder injury prevention programme. Most studies focused on baseball, lacrosse or volleyball (n=13). The risk factors examined included participation level (competition vs training) (n=10), sex (n=4), biomechanics (n=2) and external workload (n=2). The evidence for all risk factors was limited or conflicting. The effect of the prevention programme within the subgroup of uninjured players at baseline was modest and possibly lacked statistical power. All investigated potential risk factors for shoulder injury in overhead sports had limited evidence, and most were non-modifiable (eg, sex). There is also limited evidence for the effect of shoulder injury prevention measures in overhead sports. CRD42015026850. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Reliable Multihop Broadcast Protocol with a Low-Overhead Link Quality Assessment for ITS Based on VANETs in Highway Scenarios

PubMed Central

Galaviz-Mosqueda, Alejandro; Villarreal-Reyes, Salvador; Galeana-Zapién, Hiram; Rubio-Loyola, Javier; Covarrubias-Rosales, David H.

2014-01-01

Vehicular ad hoc networks (VANETs) have been identified as a key technology to enable intelligent transport systems (ITS), which are aimed to radically improve the safety, comfort, and greenness of the vehicles in the road. However, in order to fully exploit VANETs potential, several issues must be addressed. Because of the high dynamic of VANETs and the impairments in the wireless channel, one key issue arising when working with VANETs is the multihop dissemination of broadcast packets for safety and infotainment applications. In this paper a reliable low-overhead multihop broadcast (RLMB) protocol is proposed to address the well-known broadcast storm problem. The proposed RLMB takes advantage of the hello messages exchanged between the vehicles and it processes such information to intelligently select a relay set and reduce the redundant broadcast. Additionally, to reduce the hello messages rate dependency, RLMB uses a point-to-zone link evaluation approach. RLMB performance is compared with one of the leading multihop broadcast protocols existing to date. Performance metrics show that our RLMB solution outperforms the leading protocol in terms of important metrics such as packet dissemination ratio, overhead, and delay. PMID:25133224

Tribologic analyses of a self-mated aluminium contact used for overhead transmission lines

NASA Astrophysics Data System (ADS)

Steier, V. Franco

2017-05-01

The lifetime of aluminium components is often limited to their poor wear resistance. One example for such aluminium applications are overhead transmission lines. The sore points of these lines are the segments where the aluminium conductors are fixed to the line supports. The fixation is commonly realized via aluminium suspension clamps. Here, a superposition of different loads like traction and bending stresses, clamping forces and different types of wear occurs. To investigate the wear behaviour in these peculiar points, tribologic model tests were carried out. Within the tests, overhead conductor wires and aluminium plates, extracted from suspension clamps were reciprocally slid against aluminium plates (cylinder-on-plate test). The COF and a wear related parameter were recorded constantly. Subsequently, the loaded surfaces were analysed using confocal laser and electron scanning microscopy as well as energy dispersive X-ray spectroscopy. The investigation detected the formation of an oxidized tribologic layer between both components. The tribolayer, which mayor part adhered on the suspension clamps, was mostly formed from material removed from the conductor wires.

THE RECOGNITION AND TREATMENT OF SUPERIOR LABRAL (SLAP) LESIONS IN THE OVERHEAD ATHLETE

PubMed Central

Macrina, Leonard C.; Cain, E. Lyle; Dugas, Jeffrey R.; Andrews, James R.

2013-01-01

The overhead athlete presents with a unique profile that may predispose them to specific pathology. Injury to the superior aspect of the glenoid labrum (SLAP lesions) poses a significant challenge to the rehabilitation specialist due to the complex nature and wide variety of etiological factors associated with these lesions. A thorough clinical evaluation and proper identification of the extent of labral injury is important in order to determine the most appropriate non‐operative and/or surgical management. Postoperative rehabilitation is based on the specific surgical procedure that has been performed, as well as the extent, location, and mechanism of labral pathology and associated lesions. Emphasis is placed on protecting the healing labrum while gradually restoring range of motion, strength, and dynamic stability of the glenohumeral joint. The purpose of this paper is to provide an overview of the anatomy and pathomechanics of SLAP lesions and review specific clinical examination techniques used to identify these lesions in the overhead athlete. Furthermore, a review of the current surgical management and postoperative rehabilitation guidelines is provided. Level of Evidence: 5 PMID:24175139

Method and apparatus for production of subsea hydrocarbon formations

DOEpatents

Blandford, Joseph W.

1994-01-01

A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and export riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

Method and apparatus for production of subsea hydrocarbon formations

DOEpatents

Blandford, Joseph W.

1992-01-01

A well tender system for controlling, separating, storing and offloading well fluids produced from subsea hydrocarbon formations. The system comprises a vertically aligned series of tethered cylindrical tanks which are torsionally stabilized by flexible catenary production riser and expert riser bundles, and serviced by separate catenary pipe bundles. Piles are secured to the seabed, each pile assembly being pivotally connected to a lower rigid tendon, which is in turn connected to tendons arranged about the periphery of the interconnected cylindrical tanks.

Characterization Results For The 2013 HTF 3H Evaporator Overhead Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washington, A. L. II

2013-12-04

This report tabulates the radiochemical analysis of the 3H evaporator overhead sample for {sup 137}Cs, {sup 90}Sr, and {sup 129}I to meet the requirements in the Effluent Treatment Project (ETP) Waste Acceptance Criteria (WAC) (rev. 6). This report identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. All data was found to be within the ETP WAC (rev. 6) specification for the Waste Water Collection Tanks (WWCT).

Monitoring of Overhead Transmission Lines: A Review from the Perspective of Contactless Technologies

NASA Astrophysics Data System (ADS)

Khawaja, Arsalan Habib; Huang, Qi; Khan, Zeashan Hameed

2017-12-01

This paper describes a comprehensive review of non-contact technologies for overhead power transmission lines. Due to ever increasing emphasis on reducing accidents and speeding up diagnosis for automatically controlled grids, real time remote sensing and actuation is the new horizon for smart grid implementation. The technology overview with emphasis on the practical implementation of advanced non-contact technologies is discussed in this paper while considering optimization of the high voltage transmission lines parameters. In case of fault, the voltage and the current exceed limits of operation and hence real time reporting for control and diagnosis is a critical requirement. This paper aims to form a strong foundation for control and diagnosis of future power distribution systems so that a practitioner or researcher can make choices for a workable solution in smart grid implementation based on non-contact sensing.

Steps for arm and trunk actions of overhead forehand stroke used in badminton games across skill levels.

PubMed

Wang, Jianyu; Liu, Wenhao; Moffit, Jeffrey

2009-08-01

The purpose of this study was to examine arm and trunk actions in overhead forehand strokes used in badminton games across skill levels. The participants were 80 students (40 boys, 40 girls) who were randomly selected from video recordings of 300 students ages 16 to 19 years. The videotaped performances of overhead forehand strokes were coded based on three steps of arm action (elbow flexion, elbow and humeral flexion, and upward backswing) and three steps of trunk action (no trunk action, forward-backward movement, and trunk rotation). Students across the four skill levels exhibited different patterns of arm and trunk actions. Students at advanced levels used more mature arm and trunk actions.

Effects of rotation on the nighttime brightness of overhead highway signs utilizing high intensity sheeting.

DOT National Transportation Integrated Search

1974-01-01

As an initial step in the establishment of guidelines for the use of high intensity sheeting on overhead signs, a pilot study was made to investigate the effect of rotation on the average nighttime brightness of signs utilizing this material. Rotatio...

Cost Analysis and Overhead Charges at a Major Research University. AIR Forum 1982 Paper.

ERIC Educational Resources Information Center

Young, Michael E.; Geason, Ronald W.

The development of a cost allocation model at Ohio State University is discussed. The model was designed to measure the direct, indirect, and total operating costs of university operations and to recover general fund overhead costs associated with unrestricted general fund support of auxiliary enterprises and revenue-generating activities. The…

An assessment of alternatives to the Eichleay formula for unabsorbed overhead in delay claims : final report.

DOT National Transportation Integrated Search

1988-01-01

This report presents an assessment of the accuracy of alternatives available to calculate unabsorbed overhead in construction delay claims submitted by contractors. It reviews the alternatives available, concludes that the Eichleay method, used by ma...

Study of Corrosion Resistance Improvement by Metallic Coating for Overhead Transmission Line Conductor

NASA Astrophysics Data System (ADS)

Isozaki, Masanori; Adachi, Kouichi; Hita, Takanori; Asano, Yuji

Applying anti-corrosion grease and aluminum clad steel (AC) wires to ACSR has adopted as general methods to prevent overhead transmission line conductors and/or wires from corrosion. However, there are some cases that ineffectiveness of those means are reported on some transmission lines passing through acid atmosphere in the vicinity of a factory exhausting acid smoke. The feature of the corrosion caused by acid atmosphere is to show a higher speed in its progressing as well known. As means against such acid corrosion, application of high purity aluminum, selective removal of inter-metallic compound in aluminum and plastic coating wires has been reported before, and each has both of advantage and disadvantage actually. In the former letter, we reported the new type of anti-corrosion grease that shows an excellent property against acid atmosphere as well as in a salty circumstance. Here presents a new type of anti-corrosion technology of applying high corrosion resistance aluminum alloy or zinc coatings on each component wires of a conductor that we succeed in developing through a serial study of anti-corrosion methods on overhead transmission lines.

Overhead work and shoulder-neck pain in orchard farmers harvesting pears and apples.

PubMed

Sakakibara, H; Miyao, M; Kondo, T; Yamada, S

1995-04-01

The effects of overhead work were studied by comparing orchard farmers' musculoskeletal symptoms while bagging pears with those same symptoms while bagging apples. The subjects were 52 Japanese female farmers, who were examined twice an evening in late June for bagging pears, and during another evening of late July for bagging apples, when each task had been almost finished. They were questioned about musculoskeletal complaints of stiffness and pain during each job, and examined for muscle tenderness and pain from joint movement. Arm elevation angles during the work were measured for each type of bagging. The prevalence of stiffness and pain in the neck and shoulder, muscle tenderness in the shoulder regions, and pain in neck motion were found to be significantly higher when bagging pears than apples. Musculoskeletal symptoms of parts other than the neck and shoulder did not differ between the two types of bagging. The working posture of elevating the arm more than 90 degrees was assumed to account for 75% of the time bagging pears, against 40% for bagging apples. Overhead work requiring arm elevation and head extension was considered to be closely related with shoulder-neck disorders among farmers.

How To Set Up Your Own Small Business. Volumes I-II and Overhead Transparencies.

ERIC Educational Resources Information Center

Fallek, Max

This two-volume textbook and collection of overhead transparency masters is intended for use in a course in setting up a small business. The following topics are covered in the first volume: getting off to a good start, doing market research, forecasting sales, financing a small business, understanding the different legal needs of different types…

Evaluation of the Performance Characteristics of the CGLSS and NLDN Systems Based on Two Years of Ground-Truth Data from Launch Complex 39B, Kennedy Space Center, Florida

NASA Technical Reports Server (NTRS)

Mata, Carlos T.; Hill, Jonathan D.; Mata, Angel G.; Cummins, Kenneth L.

2014-01-01

From May 2011 through July 2013, the lightning instrumentation at Launch Complex 39B (LC39B) at the Kennedy Space Center, Florida, has obtained high-speed video records and field change waveforms (dE/dt and three-axis dH/dt) for 54 negative polarity return strokes whose strike termination locations and times are known with accuracy of the order of 10 m or less and 1 µs, respectively. A total of 18 strokes terminated directly to the LC39B lighting protection system (LPS), which contains three 181 m towers in a triangular configuration, an overhead catenary wire system on insulating masts, and nine down conductors. An additional 9 strokes terminated on the 106 m lightning protection mast of Launch Complex 39A (LC39A), which is located about 2.7 km southeast of LC39B. The remaining 27 return strokes struck either on the ground or attached to low-elevation grounded objects within about 500 m of the LC39B LPS. Leader/return stroke sequences were imaged at 3200 frames/sec by a network of six Phantom V310 high-speed video cameras. Each of the three towers on LC39B had two high-speed cameras installed at the 147 m level with overlapping fields of view of the center of the pad. The locations of the strike points of 54 return strokes have been compared to time-correlated reports of the Cloud-to-Ground Lightning Surveillance System (CGLSS) and the National Lightning Detection Network (NLDN), and the results of this comparison will be presented and discussed.

Unevenness of Sliding Surface of Overhead Rigid Conductor Lines and Method for Reducing Unevenness

NASA Astrophysics Data System (ADS)

Aboshi, Mitsuo; Shimizu, Masashi

Rigid conductor lines are used in many subways, because the use of such conductor lines reduces the risk of accidents and because less space is required for their installation. However, as the unevenness of the sliding surface of the rigid conductor lines significantly influences the fluctuations in the contact force between pantographs and contact lines, it is necessary to decrease the unevenness at the construction as well as the maintenance stages. In order to investigate the installation accuracy of overhead rigid conductor lines, we have developed a device that accurately and continuously measures the unevenness of the sliding surface. By using this measuring device, we have confirmed that the unevenness of the sliding surface depends on various factors such as the sag between the support points, the deformation of the aluminum base or the conductive rail in the case of a long wavelength, the slight sagging unevenness between the bolts of the long ear, the undulating wear etc. This paper describes the actual unevenness conditions and the technical methods for decreasing the unevenness of the sliding surface of overhead rigid conductor lines.

KSC-2009-2252

NASA Image and Video Library

2009-03-19

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, catenary wires are being suspended from the lighting masts on the lightning towers. The catenary wire system under development for the Constellation Program’s next-generation vehicles will significantly increase the shielding level, providing better protection, and further separate the electrical current from vital launch hardware. The system will help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers. Photo credit: NASA/Jack Pfaller

KSC-2009-2251

NASA Image and Video Library

2009-03-19

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, catenary wires are being suspended from the lighting masts on the lightning towers. The catenary wire system under development for the Constellation Program’s next-generation vehicles will significantly increase the shielding level, providing better protection, and further separate the electrical current from vital launch hardware. The system will help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers. Photo credit: NASA/Jack Pfaller

KSC-2009-2255

NASA Image and Video Library

2009-03-19

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, catenary wires are being suspended from the lighting masts on the lightning towers. The catenary wire system under development for the Constellation Program’s next-generation vehicles will significantly increase the shielding level, providing better protection, and further separate the electrical current from vital launch hardware. The system will help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers. Photo credit: NASA/Jack Pfaller

KSC-2009-2254

NASA Image and Video Library

2009-03-19

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, catenary wires are being suspended from the lighting masts on the lightning towers. The catenary wire system under development for the Constellation Program’s next-generation vehicles will significantly increase the shielding level, providing better protection, and further separate the electrical current from vital launch hardware. The system will help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers. Photo credit: NASA/Jack Pfaller

KSC-2009-2253

NASA Image and Video Library

2009-03-19

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, catenary wires are being suspended from the lighting masts on the lightning towers. The catenary wire system under development for the Constellation Program’s next-generation vehicles will significantly increase the shielding level, providing better protection, and further separate the electrical current from vital launch hardware. The system will help avoid delays to the launch schedule by collecting more information on the strike for analysis by launch managers. Photo credit: NASA/Jack Pfaller

Movement compatibility for configurations of displays located in three cardinal orientations and ipsilateral, contralateral and overhead controls.

PubMed

Chan, Alan H S; Hoffmann, Errol R

2012-01-01

Stereotype strength and reversibility were determined for displays that were in the Front, Right and Left orientations relative to the operator, along with rotary, horizontally and vertically-moving controls located in the overhead, left-sagittal and right-sagittal planes. In each case, responses were made using the left and right hands. The arrangements used were (i) rotary control with a circular display (ii) horizontal/transverse control moving forward/rearward in the left and right-sagittal planes or transversely in the overhead plane and (iii) vertical/longitudinal control moving vertically in the left and right-sagittal planes and longitudinally in the overhead plane. These are all combinations not previously researched. Stereotype strength varied with display plane, type of control and plane of control. Models for the stereotype strength are developed, showing the contribution of various components to the overall stereotype strength. The major component for horizontally-moving controls comes from the "visual field" model of Worringham and Beringer (1998); for the rotary control important factors are "clockwise-for-clockwise" and the hand/control location effect (Hoffmann, 2009a). Vertically-moving controls are governed by a simple 'up-for-up' relationship between displays and controls. Overall stereotype strength is a maximum when all components add positively. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Determination of remaining fatigue life of welded stud details on overhead aluminum sign panels in Virginia.

DOT National Transportation Integrated Search

2005-01-01

Some overhead highways signs in Virginia using a specific welded threaded stud and clip connection have failed while in service. From inspection of the signs it was determined that the failure was caused by fatigue of the weld connecting the threaded...

Triggered-Lightning Interaction with a Lightning Protective System: Current Distribution and Electromagnetic Environment

NASA Technical Reports Server (NTRS)

Mata, C. T.; Rakov, V. A.; Mata, A. G.

2010-01-01

A new comprehensive lightning instrumentation system has been designed for Launch Complex 39B (LC3913) at the Kennedy Space Center, Florida. This new instrumentation system includes the synchronized recording of six high-speed video cameras; currents through the nine downconductors of the new lightning protection system for LC3913; four dH/dt, 3-axis measurement stations; and five dE/dt stations composed of two antennas each. A 20:1 scaled down model of the new Lightning Protection System (LPS) of LC39B was built at the International Center for Lightning Research and Testing, Camp Blanding, FL. This scaled down lightning protection system was instrumented with the transient recorders, digitizers, and sensors to be used in the final instrumentation installation at LC3913. The instrumentation used at the ICLRT is also a scaled-down instrumentation of the LC39B instrumentation. The scaled-down LPS was subjected to seven direct lightning strikes and six (four triggered and two natural nearby flashes) in 2010. The following measurements were acquired at the ICLRT: currents through the nine downconductors; two dl-/dt, 3-axis stations, one at the center of the LPS (underneath the catenary wires), and another 40 meters south from the center of the LPS; ten dE/dt stations, nine of them on the perimeter of the LPS and one at the center of the LPS (underneath the catenary wire system); and the incident current. Data from representative events are presented and analyzed in this paper.

View northeast of a microchip based computer control system installed ...

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

View northeast of a microchip based computer control system installed in the early 1980's to replace Lamokin Tower, at center of photograph; panels 1 and 2 at right of photograph are part of main supervisory board; panel 1 controlled Allen Lane sub-station #7; responsiblity for this portion of the system was transferred to southeast Pennsylvania transit authority (septa) in 1985; panel 2 at extreme right controls catenary switches in a coach storage yard adjacent to the station - Thirtieth Street Station, Power Director Center, Thirtieth & Market Streets in Amtrak Railroad Station, Philadelphia, Philadelphia County, PA

Humeral stress edema: an injury in overhead athletes quarterback with humeral "shin" splints-a case report.

PubMed

Alpert, Justin; Flannery, Robert; Epstein, Robert; Monaco, Robert; Prendergast, Nancy

2014-09-01

Stress injury to the distal humerus has been reported as a cause of chronic arm pain among competitive tennis players. As the serve is technically similar to an overhead throwing motion, it is conceivable that this injury could occur in other overhead athletes. Overuse injuries, including rotator cuff tears, ulnar collateral ligament injuries, and joint sprains have routinely been reported in quarterbacks, but there are few reported cases of upper extremity bony stress injuries in these athletes. Magnetic resonance imaging aids in the diagnostic evaluation of an upper extremity injury as it can identify numerous structural injuries and early stress changes within bone. Accurately diagnosing stress reactions helps prevent progression toward stress fracture, which is possible if conservative measures are initiated early in the rehabilitation period. In this article, we report the case of an elite college quarterback who presented with localized elbow pain while throwing.

Allocating physicians' overhead costs to services: an econometric/accounting-activity based-approach.

PubMed

Peden, Al; Baker, Judith J

2002-01-01

Using the optimizing properties of econometric analysis, this study analyzes how physician overhead costs (OC) can be allocated to multiple activities to maximize precision in reimbursing the costs of services. Drawing on work by Leibenstein and Friedman, the analysis also shows that allocating OC to multiple activities unbiased by revenue requires controlling for revenue when making the estimates. Further econometric analysis shows that it is possible to save about 10 percent of OC by paying only for those that are necessary.

Functional Multijoint Position Reproduction Acuity in Overhead-Throwing Athletes

PubMed Central

Tripp, Brady L; Uhl, Timothy L; Mattacola, Carl G; Srinivasan, Cidambi; Shapiro, Robert

2006-01-01

Context: Baseball players rely on the sensorimotor system to uphold the balance between upper extremity stability and mobility while maintaining athletic performance. However, few researchers have studied functional multijoint measures of sensorimotor acuity in overhead-throwing athletes. Objective: To compare sensorimotor acuity between 2 high-demand functional positions and among planes of motion within individual joints and to describe a novel method of measuring sensorimotor function. Design: Single-session, repeated-measures design. Setting: University musculoskeletal research laboratory. Patients or Other Participants: Twenty-one National Collegiate Athletic Association Division I baseball players (age = 20.8 ± 1.5 years, height = 181.3 ± 5.1 cm, mass = 87.8 ± 9.1 kg) with no history of upper extremity injury or central nervous system disorder. Main Outcome Measure(s): We measured active multijoint position reproduction acuity in multiple planes using an electromagnetic tracking device. Subjects reproduced 2 positions: arm cock and ball release. We calculated absolute and variable error for individual motions at the scapulothoracic, glenohumeral, elbow, and wrist joints and calculated overall joint acuity with 3-dimensional variable error. Results: Acuity was significantly better in the arm-cock position compared with ball release at the scapulothoracic and glenohumeral joints. We observed significant differences among planes of motion within the scapulothoracic and glenohumeral joints at ball release. Scapulothoracic internal rotation and glenohumeral horizontal abduction and rotation displayed less acuity than other motions. Conclusions: We established the reliability of a functional measure of upper extremity sensorimotor system acuity in baseball players. Using this technique, we observed differences in acuity between 2 test positions and among planes of motion within the glenohumeral and scapulothoracic joints. Clinicians may consider these

Multivariable Time Series Prediction for the Icing Process on Overhead Power Transmission Line

PubMed Central

Li, Peng; Zhao, Na; Zhou, Donghua; Cao, Min; Li, Jingjie; Shi, Xinling

2014-01-01

The design of monitoring and predictive alarm systems is necessary for successful overhead power transmission line icing. Given the characteristics of complexity, nonlinearity, and fitfulness in the line icing process, a model based on a multivariable time series is presented here to predict the icing load of a transmission line. In this model, the time effects of micrometeorology parameters for the icing process have been analyzed. The phase-space reconstruction theory and machine learning method were then applied to establish the prediction model, which fully utilized the history of multivariable time series data in local monitoring systems to represent the mapping relationship between icing load and micrometeorology factors. Relevant to the characteristic of fitfulness in line icing, the simulations were carried out during the same icing process or different process to test the model's prediction precision and robustness. According to the simulation results for the Tao-Luo-Xiong Transmission Line, this model demonstrates a good accuracy of prediction in different process, if the prediction length is less than two hours, and would be helpful for power grid departments when deciding to take action in advance to address potential icing disasters. PMID:25136653

Improving nitrogen fertilizer use efficiency in surface- and overhead sprinkler-irrigated cotton in the desert southwest

USDA-ARS?s Scientific Manuscript database

Nitrogen fertilizer use efficiency (NUE) is low in surface-irrigated cotton (Gossypium hirsutum L.), especially when adding N to irrigation water. A NO3 soil-test algorithm was compared with canopy reflectance-based N management with surface- overhead sprinkler-irrigation in Central AZ. The surfac...

Longitudinal acceleration tests of overhead luggage bins and auxiliary fuel tank in a transport airplane airframe section

DOT National Transportation Integrated Search

1999-06-01

This report contains the description and test results of overhead stowage bin calibrations and longitudinal impact testing of a 10-foot transport airframe section conducted at the Transportation Research Center Inc. (TRC). The purpose of the tests wa...

Crash Simulation of a Vertical Drop Test of a B737 Fuselage Section with Overhead Bins and Luggage

NASA Technical Reports Server (NTRS)

Jackson, Karen E.; Fasanella, Edwin L.

2004-01-01

The focus of this paper is to describe a crash simulation of a 30-ft/s vertical drop test of a Boeing 737 (B737) fuselage section. The drop test of the 10-ft. long fuselage section of a B737 aircraft was conducted in November of 2000 at the FAA Technical Center in Atlantic City, NJ. The fuselage section was outfitted with two different commercial overhead stowage bins. In addition, 3,229-lbs. of luggage were packed in the cargo hold to represent a maximum take-off weight condition. The main objective of the test was to evaluate the response and failure modes of the overhead stowage bins in a narrow-body transport fuselage section when subjected to a severe, but survivable, impact. A secondary objective of the test was to generate experimental data for correlation with the crash simulation. A full-scale 3-dimensional finite element model of the fuselage section was developed and a crash simulation was conducted using the explicit, nonlinear transient dynamic code, MSC.Dytran. Pre-test predictions of the fuselage and overhead bin responses were generated for correlation with the drop test data. A description of the finite element model and an assessment of the analytical/experimental correlation are presented. In addition, suggestions for modifications to the model to improve correlation are proposed.

Does scapula stabilizing t-shirt help over-head athletes in shoulder discomfort? A randomized control study.

PubMed

Pellegrini, Andrea; Pogliacomi, Francesco; Costantino, Cosimo; Desimoni, Stefano; Giovanelli, Margherita; Golz, Andrew; Tonino, Pietro; Ceccarelli, Francesco

2016-04-15

Scapular dyskinesis in pitchers can potentially lead to impairments in the optimal performance of muscles of the shoulder complex. The purpose of this prospective study was to evaluate whether the use of a scapula stabilizing t-shirt can decrease stress and discomfort in over-head baseball pitchers. Thirty-two semi-professional baseball pitchers were divided into 2 groups. Group A dressed the scapula stabilizing t-shirt during the weekly practice while group B (control group) continued to follow their training program without the t-shirt. All pitchers underwent a clinical examination at the beginning of the study (T0), 4 weeks (T1) and 8 weeks after (T2). Data collected showed a better clinical outcome at T1 which increased in T2 for pitchers in Group A, while in Group B athletes these positive results were not observed. This study underlines that scapula-stabilizing t-shirt can have positive effects on shoulder discomfort in over-head athletes.

76 FR 44246 - Special Conditions: Boeing Model 747-8 Series Airplanes; Overhead Flight Attendant Rest Compartment

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-25

...; Special Conditions No. 25-442-SC] Special Conditions: Boeing Model 747-8 Series Airplanes; Overhead Flight... conditions. SUMMARY: These special conditions are issued for Boeing Model 747-8 series airplanes. These... applied for, and was granted, an extension of time for the amended type certificate, which changed the...

Growth, nitrogen use efficiency, and leachate comparison of subirrigated and overhead irrigated pale purple coneflower seedlings

Treesearch

Jeremy R. Pinto; Rhiannon A. Chandler; R. Kasten Dumroese

2008-01-01

Pale purple coneflower [Echinacea pallida (Nutt.) Nutt.] was grown within three container volumes (90, 105, and 340 cm3) under subirrigation and overhead irrigation treatments. Subirrigated coneflowers showed increased seedling quality with more biomass (14%), better nitrogen use efficiency (13%), greater nitrogen content (N; 11%), more height (15...

Demonstrating Biological Principles Efficiently and Effectively: The Overhead Is More than Just a Lighted Chalkboard

ERIC Educational Resources Information Center

Barden-Gabbei, Laura M.

2006-01-01

The overhead projector is an excellent tool for teachers at both the high school and college level. Teachers often use it to display class notes as they monitor students' actions and reactions to the concepts being presented and discussed, to display diagrams and figures too complex to draw on the chalkboard, and more recently to display computer…

Postural stability is compromised by fatiguing overhead work.

PubMed

Nussbaum, Maury A

2003-01-01

In a laboratory setting, 16 participants performed a repetitive overhead tapping task for 3 hours or until self-terminated due to substantial shoulder discomfort. Several measures of postural sway and stability were obtained using a force plate, both during quiet standing and during performance of the tapping task. Sway area and peak sway velocity showed consistent increases with time, whereas changes in average velocity and peak whole-body center-of-mass acceleration were either small or nonsignificant. Although relatively insensitive to several task variables, changes in sway areas and peak velocities were substantially larger in trials terminated by the participants. It is argued that fatigue plays a more important role than simple task duration in causing the observed increases in sway, and hence decreases in postural stability. Potential whole-body consequences of localized musculoskeletal stresses appear supported by the results, and implications for safety, risks of falls, and work scheduling are discussed.

Characterization Results for the 2014 HTF 3H & 2H Evaporator Overhead Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Washington, A.

2015-05-11

This report tabulates the radiochemical analysis of the 3H and 2H evaporator overhead samples for 137Cs, 90Sr, and 129I to meet the requirements in the Effluent Treatment Project (ETP) Waste Acceptance Criteria (WAC) (rev. 6). This report identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. All data was found to be within the ETP WAC (rev. 6) specification for the Waste Water Collection Tanks (WWCT).

The isokinetic rotator cuff strength ratios in overhead athletes: Assessment and exercise effect.

PubMed

Berckmans, Kelly; Maenhout, Annelies G; Matthijs, Lien; Pieters, Louise; Castelein, Birgit; Cools, Ann M

2017-09-01

Muscle strength imbalance in the shoulder region can be considered as a predisposing factor in the development of movement dysfunctions, possibly leading to overuse injuries. Repetitive overhead throwing, performed in sports, may result in muscle imbalance between the external (ER) and internal (IR) rotators. Muscle strength measured with an isokinetic device, is reported as a concentric (CON) or eccentric (ECC) force. The balance between an agonist and an antagonist is mentioned as a ratio (CON/CON or ECC/CON). The aim of this systematic literature review is to provide an overview of the existing evidence considering the isokinetic muscle strength ratios of ER and IR of the shoulder in healthy overhead athletes. In addition, the effect of exercise programs on these ratios was investigated. Two online databases (Web of Science and PubMed) were consulted using different search strategies. Articles were selected based on inclusion and exclusion criteria. All included articles were assessed on their methodological quality. There is moderate evidence for a lower functional deceleration ratio (ECC ER/CON IR) at the dominant side. This lower ratio is due to a large overweight of CON IR strength on that side. There is no consensus about which exercise program is the most effective in altering the shoulder isokinetic strength ratios. Copyright © 2017 Elsevier Ltd. All rights reserved.

Zero-overhead phase noise compensation via decision-directed phase equalizer for coherent optical OFDM.

PubMed

Mousa-Pasandi, Mohammad E; Plant, David V

2010-09-27

We report and investigate the feasibility of zero-overhead laser phase noise compensation (PNC) for long-haul coherent optical orthogonal frequency division multiplexing (CO-OFDM) transmission systems, using the decision-directed phase equalizer (DDPE). DDPE updates the equalization parameters on a symbol-by-symbol basis after an initial decision making stage and retrieves an estimation of the phase noise value by extracting and averaging the phase drift of all OFDM sub-channels. Subsequently, a second equalization is performed by using the estimated phase noise value which is followed by a final decision making stage. We numerically compare the performance of DDPE and the CO-OFDM conventional equalizer (CE) for different laser linewidth values after transmission over 2000 km of uncompensated single-mode fiber (SMF) at 40 Gb/s and investigate the effect of fiber nonlinearity and amplified spontaneous emission (ASE) noise on the received signal quality. Furthermore, we analytically analyze the complexity of DDPE versus CE in terms of the number of required complex multiplications per bit.

Assessing the effects of underground mining activities on high-voltage overhead power lines

NASA Astrophysics Data System (ADS)

Gusev, Vladimir; Zhuravlyov, Alexei; Maliukhina, Elena

2017-11-01

This paper introduces a technique for predictive assessment of changes in the position of power transmission towers and condition of overhead power lines, located in the zone of influence of displacements and deformations of the Earth's surface caused by mining activities. A special approach for monitoring the technical condition of towers and cables is proposed. It is intended to address the issue of controlling the condition of transmission lines that are under the influence of underground mining activities and to checkmate such impact.

An improved input shaping design for an efficient sway control of a nonlinear 3D overhead crane with friction

NASA Astrophysics Data System (ADS)

Maghsoudi, Mohammad Javad; Mohamed, Z.; Sudin, S.; Buyamin, S.; Jaafar, H. I.; Ahmad, S. M.

2017-08-01

This paper proposes an improved input shaping scheme for an efficient sway control of a nonlinear three dimensional (3D) overhead crane with friction using the particle swarm optimization (PSO) algorithm. Using this approach, a higher payload sway reduction is obtained as the input shaper is designed based on a complete nonlinear model, as compared to the analytical-based input shaping scheme derived using a linear second order model. Zero Vibration (ZV) and Distributed Zero Vibration (DZV) shapers are designed using both analytical and PSO approaches for sway control of rail and trolley movements. To test the effectiveness of the proposed approach, MATLAB simulations and experiments on a laboratory 3D overhead crane are performed under various conditions involving different cable lengths and sway frequencies. Their performances are studied based on a maximum residual of payload sway and Integrated Absolute Error (IAE) values which indicate total payload sway of the crane. With experiments, the superiority of the proposed approach over the analytical-based is shown by 30-50% reductions of the IAE values for rail and trolley movements, for both ZV and DZV shapers. In addition, simulations results show higher sway reductions with the proposed approach. It is revealed that the proposed PSO-based input shaping design provides higher payload sway reductions of a 3D overhead crane with friction as compared to the commonly designed input shapers.

Development and Sensing Properties Study of Underwater Assembled Water Depth-Inclination Sensors for a Multi-Component Mooring System, Using a Self-Contained Technique

PubMed Central

Wu, Wenhua; Feng, Jiaguo; Xie, Bin; Tang, Da; Yue, Qianjin; Xie, Ribin

2016-01-01

Prototype monitoring techniques play an important role in the safety guarantee of mooring systems in marine engineering. In general, the complexities of harsh ocean environmental conditions bring difficulties to the traditional monitoring methods of application, implementation and maintenance. Large amounts of existing mooring systems still lack valid monitoring strategies. In this paper, an underwater monitoring method which may be used to achieve the mechanical responses of a multi-point catenary mooring system, is present. A novel self-contained assembled water depth-inclination (D-I) sensor is designed and manufactured. Several advanced technologies, such as standalone, low power consumption and synchronism, are considered to satisfy the long-term implementation requirements with low cost during the design process. The design scheme of the water resistance barrel and installation clamp, which satisfies the diver installation, are also provided in the paper. An on-site test has previously been carried out on a production semisubmersible platform in the South China Sea. The prototype data analyses, including the D-I value in the time domain (including the data recorded during the mooring retraction and release process) and spectral characteristics, are presented to reveal the accuracy, feasibility and stability of the sensor in terms of fitting for the prototype monitoring of catenary mooring systems, especially for in-service aging platforms. PMID:27854357

Calculating the Lightning Protection System Downconductors' Grounding Resistance at Launch Complex 39B, Kennedy Space Center

NASA Technical Reports Server (NTRS)

Mata, Carlos T.; Mata, Angel G.

2012-01-01

A new Lightning Protection System (LPS) was designed and built at Launch Complex 39B (LC39B), at the Kennedy Space Center (KSC), Florida, which consists of a catenary wire system (at a height of about 181 meters above ground level) supported by three insulators installed atop three towers in a triangular configuration. Nine downconductors (each about 250 meters long) are connected to the catenary wire system. Each downconductor is connected to a 7.62-meter-radius circular counterpoise conductor with six equally spaced, 6-meter-long vertical grounding rods. Grounding requirements at LC39B call for all underground and aboveground metallic piping, enclosures, raceways, and cable trays, within 7.62 meters of the counterpoise, to be bonded to the counterpoise, which results in a complex interconnected grounding system, given the many metallic piping, raceways, and cable trays that run in multiple directions around LC39B. The complexity of this grounding system makes the fall-of-potential method, which uses multiple metallic rods or stakes, unsuitable for measuring the grounding impedances of the downconductors. To calculate the grounding impedance of the downconductors, an Earth Ground Clamp (EGC) (a stakeless device for measuring grounding impedance) and an Alternative Transient Program (ATP) model of the LPS are used. The EGC is used to measure the loop impedance plus the grounding impedance of each downconductor, and the ATP model is used to calculate the loop impedance of each downconductor circuit. The grounding resistance of the downconductors is then calculated by subtracting the ATP calculated loop impedances from the EGC measurements.

Characterization Results for the January 2017 H-Tank Farm 2H Evaporator Overhead Sample

DOE Office of Scientific and Technical Information (OSTI.GOV)

Truong, T.; Nicholson, J.

2017-04-11

This report contains the radioanalytical results of the 2H evaporator overhead sample received at SRNL on January 19, 2017. Specifically, concentrations of 137Cs, 90Sr, and 129I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). All of the radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits.

Characterization results for the October 2015-Tank for farm 3H evaporator overhead examples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholson, J. C.

2016-01-28

This report contains the radioanalytical results of the 3H evaporator overhead sample received at SRNL on October 13, 2015. Specifically, concentrations of 137Cs, 90Sr, and 129I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). All of the radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits.

Characterization Results for the March 2016 H-Tank Farm 2H Evaporator Overhead Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholson, J. C.

2016-05-09

This report contains the radioanalytical results of the 2H evaporator overhead sample received at SRNL on March 16, 2016. Specifically, concentrations of 137Cs, 90Sr, and 129I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). All of the radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits.

Business Activity Monitoring: Real-Time Group Goals and Feedback Using an Overhead Scoreboard in a Distribution Center

ERIC Educational Resources Information Center

Goomas, David T.; Smith, Stuart M.; Ludwig, Timothy D.

2011-01-01

Companies operating large industrial settings often find delivering timely and accurate feedback to employees to be one of the toughest challenges they face in implementing performance management programs. In this report, an overhead scoreboard at a retailer's distribution center informed teams of order selectors as to how many tasks were…

STS-30 aft flight deck onboard view of overhead window, Earth limb, cow photo

NASA Technical Reports Server (NTRS)

1989-01-01

Since the beginning of manned space travel, astronauts have taken onboard with them items of person sentiment. During STS-30 onboard Atlantis, Orbiter Vehicle (OV) 104, Mission Specialist Mark C. Lee brought along a photograph of a cow. The photo testifies to his background as one reared on a Wisconsin farm and is displayed on aft flight deck alongside an overhead window. Outside the window, some 160 nautical miles away, is the cloud-covered Earth surface.

McrEngine: A Scalable Checkpointing System Using Data-Aware Aggregation and Compression

DOE PAGES

Islam, Tanzima Zerin; Mohror, Kathryn; Bagchi, Saurabh; ...

2013-01-01

High performance computing (HPC) systems use checkpoint-restart to tolerate failures. Typically, applications store their states in checkpoints on a parallel file system (PFS). As applications scale up, checkpoint-restart incurs high overheads due to contention for PFS resources. The high overheads force large-scale applications to reduce checkpoint frequency, which means more compute time is lost in the event of failure. We alleviate this problem through a scalable checkpoint-restart system, mcrEngine. McrEngine aggregates checkpoints from multiple application processes with knowledge of the data semantics available through widely-used I/O libraries, e.g., HDF5 and netCDF, and compresses them. Our novel scheme improves compressibility ofmore » checkpoints up to 115% over simple concatenation and compression. Our evaluation with large-scale application checkpoints show that mcrEngine reduces checkpointing overhead by up to 87% and restart overhead by up to 62% over a baseline with no aggregation or compression.« less

Improvement of automatic control system for high-speed current collectors

NASA Astrophysics Data System (ADS)

Sidorov, O. A.; Goryunov, V. N.; Golubkov, A. S.

2018-01-01

The article considers the ways of regulation of pantographs to provide quality and reliability of current collection at high speeds. To assess impact of regulation was proposed integral criterion of the quality of current collection, taking into account efficiency and reliability of operation of the pantograph. The study was carried out using mathematical model of interaction of pantograph and catenary system, allowing to assess contact force and intensity of arcing at the contact zone at different movement speeds. The simulation results allowed us to estimate the efficiency of different methods of regulation of pantographs and determine the best option.

Cross-cultural adaptation of Kerlan-Jobe Orthopaedic Clinic shoulder and elbow score: Reliability and validity in Turkish-speaking overhead athletes.

PubMed

Turgut, Elif; Tunay, Volga Bayrakci

2018-03-09

Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow Score (KJOC-SES) is a subjective assessment tool to measure functional status of the upper extremities in overhead athletes. The aim was to translate and culturally adapt the KJOC-SES and to evaluate the psychometric properties of the Turkish version (KJOC-SES-Tr) in overhead athletes. The forward and back-translation method was followed. One hundred and twenty-three overhead athletes completed the KJOC-SES-Tr, the Disabilities of the Arm, Shoulder, and Hand (DASH), and the American Shoulder and Elbow Surgeons Evaluation Form (ASES). Participants were assigned to one of the following subgroups: asymptomatic (playing without pain) or symptomatic (playing with pain, or not playing due to pain). Internal consistency, reliability, construct validity, discriminant validity, and content validity of the KJOC-SES-Tr were tested. The test-retest reliability of the KJOC-SES-Tr was excellent with an interclass coefficient of 0.93. There was a strong correlation between the KJOC-SES-Tr and the DASH and the ASES, indicating that the construct validity was good for all participants. Results of the KJOC-SES-Tr significantly differed between different subgroups and categories of athletes. The floor and ceiling effects were acceptable for symptomatic athletes. The KJOC-SES-Tr was shown to be valid, reliable tool to monitor the return to sports following injuries in athletes. Copyright © 2018 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

The effects of overhead transparency design on retention, recall, and application of data analysis content.

PubMed

Van Hoozer, H; Brink, P J; Oppliger, R

1989-04-01

This experimental study tested the effects of overhead transparency design in conjunction with live lecture on retention, recall, and application of data analysis content over three occasions using a Solomon Four-Group, pretest-posttest design. Pretested subjects showed significant (p less than .001) gains in test scores from pre to posttest. No significant differences were found in pretest scores between control and experimental treatment groups or among the posttest scores of either the experimental or control groups.

MIT-Skywalker: considerations on the Design of a Body Weight Support System.

PubMed

Gonçalves, Rogério Sales; Krebs, Hermano Igo

2017-09-06

To provide body weight support during walking and balance training, one can employ two distinct embodiments: support through a harness hanging from an overhead system or support through a saddle/seat type. This paper presents a comparison of these two approaches. Ultimately, this comparison determined our selection of the body weight support system employed in the MIT-Skywalker, a robotic device developed for the rehabilitation/habilitation of gait and balance after a neurological injury. Here we will summarize our results with eight healthy subjects walking on the treadmill without any support, with 30% unloading supported by a harness hanging from an overhead system, and with a saddle/seat-like support system. We compared the center of mass as well as vertical and mediolateral trunk displacements across different walking speeds and support. The bicycle/saddle system had the highest values for the mediolateral inclination, while the overhead harness body weight support showed the lowest values at all speeds. The differences were statistically significant. We selected the bicycle/saddle system for the MIT-Skywalker. It allows faster don-and-doff, better centers the patient to the split treadmill, and allows all forms of training. The overhead harness body weight support might be adequate for rhythmic walking training but limits any potential for balance training.

Systems and methods for reactive distillation with recirculation of light components

DOEpatents

Stickney, Michael J [Nassau Bay, TX; Jones, Jr., Edward M.

2011-07-26

Systems and methods for producing gas-to-liquids products using reactive distillation are provided. The method for producing gas-to-liquids products can include reacting a feedstock in a column having a distillation zone and a reaction zone to provide a bottoms stream and an overhead stream. A first portion of the overhead stream can be recycled to the column at the top of the reaction zone and second portion of the overhead stream can be recycled to the column at the bottom of the reaction zone.

Alternative majority-voting methods for real-time computing systems

NASA Technical Reports Server (NTRS)

Shin, Kang G.; Dolter, James W.

1989-01-01

Two techniques that provide a compromise between the high time overhead in maintaining synchronous voting and the difficulty of combining results in asynchronous voting are proposed. These techniques are specifically suited for real-time applications with a single-source/single-sink structure that need instantaneous error masking. They provide a compromise between a tightly synchronized system in which the synchronization overhead can be quite high, and an asynchronous system which lacks suitable algorithms for combining the output data. Both quorum-majority voting (QMV) and compare-majority voting (CMV) are most applicable to distributed real-time systems with single-source/single-sink tasks. All real-time systems eventually have to resolve their outputs into a single action at some stage. The development of the advanced information processing system (AIPS) and other similar systems serve to emphasize the importance of these techniques. Time bounds suggest that it is possible to reduce the overhead for quorum-majority voting to below that for synchronous voting. All the bounds assume that the computation phase is nonpreemptive and that there is no multitasking.

The Discrete Hanging Cable

ERIC Educational Resources Information Center

Peters, James V.

2004-01-01

Using the methods of finite difference equations the discrete analogue of the parabolic and catenary cable are analysed. The fibonacci numbers and the golden ratio arise in the treatment of the catenary.

Voltages induced on a power distribution line by overhead cloud lightning

NASA Technical Reports Server (NTRS)

Yacoub, Ziad; Rubinstein, Marcos; Uman, Martin A.; Thomson, Ewen M.; Medelius, Pedro J.

1991-01-01

Voltages induced by overhead cloud lightning on a 448 m open circuited power distribution line and the corresponding north-south component of the lightning magnetic field were simultaneously measured at the NASA Kennedy Space Center during the summer of 1986. The incident electric field was calculated from the measured magnetic field. The electric field was then used as an input to the computer program, EMPLIN, that calculated the voltages at the two ends of the power line. EMPLIN models the frequency domain field/power coupling theory found, for example, in Ianoz et al. The direction of the source, which is also one of the inputs to EMPLIN, was crudely determined from a three station time delay technique. The authors found reasonably good agreement between calculated and measured waveforms.

Evaluation of Grounding Impedance of a Complex Lightning Protective System Using Earth Ground Clamp Measurements and ATP Modeling

NASA Technical Reports Server (NTRS)

Mata, Carlos T.; Rakov, V. A.; Mata, Angel G.

2010-01-01

A new Lightning Protection System (LPS) was designed and built at Launch Complex 39B (LC39B), at the Kennedy Space Center (KSC), Florida, which consists of a catenary wire system (at a height of about 181 meters above ground level) supported by three insulators installed atop three towers in a triangular configuration. A total of nine downconductors (each about 250 meters long, on average) are connected to the catenary wire system. Each of the nine downconductors is connected to a 7.62-meter radius circular counterpoise conductor with six equally spaced 6-meter long vertical grounding rods. Grounding requirements at LC39B call for all underground and above ground metallic piping, enclosures, raceways, and cable trays, within 7.62 meters of the counterpoise, to be bounded to the counterpoise, which results in a complex interconnected grounding system, given the many metallic piping, raceways, and cable trays that run in multiple direction around LC39B. The complexity of this grounding system makes the fall of potential method, which uses multiple metallic rods or stakes, unsuitable for measuring the grounding impedances of the downconductors. To calculate the downconductors grounding impedance, an Earth Ground Clamp (a stakeless grounding resistance measuring device) and a LPS Alternative Transient Program (ATP) model are used. The Earth Ground Clamp is used to measure the loop impedance plus the grounding impedance of each downconductor and the ATP model is used to calculate the loop impedance of each downconductor circuit. The grounding impedance of the downconductors is then calculated by subtracting the ATP calculated loop impedances from the Earth Ground Clamp measurements.

Error rates and resource overheads of encoded three-qubit gates

NASA Astrophysics Data System (ADS)

Takagi, Ryuji; Yoder, Theodore J.; Chuang, Isaac L.

2017-10-01

A non-Clifford gate is required for universal quantum computation, and, typically, this is the most error-prone and resource-intensive logical operation on an error-correcting code. Small, single-qubit rotations are popular choices for this non-Clifford gate, but certain three-qubit gates, such as Toffoli or controlled-controlled-Z (ccz), are equivalent options that are also more suited for implementing some quantum algorithms, for instance, those with coherent classical subroutines. Here, we calculate error rates and resource overheads for implementing logical ccz with pieceable fault tolerance, a nontransversal method for implementing logical gates. We provide a comparison with a nonlocal magic-state scheme on a concatenated code and a local magic-state scheme on the surface code. We find the pieceable fault-tolerance scheme particularly advantaged over magic states on concatenated codes and in certain regimes over magic states on the surface code. Our results suggest that pieceable fault tolerance is a promising candidate for fault tolerance in a near-future quantum computer.

Warning systems evaluation for overhead clearance detection : final report.

DOT National Transportation Integrated Search

2017-02-01

This study reports on off-the-shelf systems designed to detect the heights of vehicles to minimize or eliminate collisions with roadway bridges. Implemented systems were identified, reviewed, and compared and relatively inexpensive options recommende...

SMAC: A soft MAC to reduce control overhead and latency in CDMA-based AMI networks

DOE PAGES

Garlapati, Shravan; Kuruganti, Teja; Buehrer, Michael R.; ...

2015-10-26

The utilization of state-of-the-art 3G cellular CDMA technologies in a utility owned AMI network results in a large amount of control traffic relative to data traffic, increases the average packet delay and hence are not an appropriate choice for smart grid distribution applications. Like the CDG, we consider a utility owned cellular like CDMA network for smart grid distribution applications and classify the distribution smart grid data as scheduled data and random data. Also, we propose SMAC protocol, which changes its mode of operation based on the type of the data being collected to reduce the data collection latency andmore » control overhead when compared to 3G cellular CDMA2000 MAC. The reduction in the data collection latency and control overhead aids in increasing the number of smart meters served by a base station within the periodic data collection interval, which further reduces the number of base stations needed by a utility or reduces the bandwidth needed to collect data from all the smart meters. The reduction in the number of base stations and/or the reduction in the data transmission bandwidth reduces the CAPital EXpenditure (CAPEX) and OPerational EXpenditure (OPEX) of the AMI network. Finally, the proposed SMAC protocol is analyzed using markov chain, analytical expressions for average throughput and average packet delay are derived, and simulation results are also provided to verify the analysis.« less

The perceived health risks of indoor radon gas and overhead powerlines: a comparative multilevel approach.

PubMed

Poortinga, Wouter; Cox, Patrick; Pidgeon, Nick F

2008-02-01

Radon and overhead powerlines are two radiation risk cases that have raised varying levels of concern among the general public and experts. Despite both involving radiation-a typically feared and unseen health hazard-individuals' perceptions of the two risk cases may invoke rather different factors. We examined individual and geographic-contextual factors influencing public perceptions of the health risks of indoor radon gas and overhead powerlines in a comparative research design, utilizing a postal questionnaire with 1,528 members of the general public (response rate 28%) and multilevel modeling techniques. This study found that beliefs about the two risk cases mainly differed according to the level of "exposure"-defined here in terms of spatial proximity. We argue that there are two alternative explanations for this pattern of findings: that risk perception itself varies directly with proximity, or that risk is more salient to concerned people in the exposed areas. We also found that while people living in high radon areas are more concerned about the risks of indoor radon gas, they find these risks more acceptable and have more trust in authorities. These results might reflect the positive effects of successive radon campaigns in high radon areas, which may have raised awareness and concern, and at the same time may have helped to increase trust by showing that the government takes the health risks of indoor radon gas seriously, suggesting that genuine risk communication initiatives may have positive impacts on trust in risk management institutions.

An amateur's contribution to the design of Telford's Menai Suspension Bridge: a commentary on Gilbert (1826) ‘On the mathematical theory of suspension bridges’

PubMed Central

Calladine, C. R.

2015-01-01

Davies Gilbert's work on the catenary is notable on two counts. First, it influenced Thomas Telford in formulating his final design for the Menai Strait suspension bridge (1826); and second, it established for the first time the form of the ‘catenary of equal strength’. The classical catenary is a uniform flexible chain or cable hanging freely under gravity between supports. The ‘catenary of equal strength’ is the form of a cable whose cross-sectional area is made proportional to the tension at each point, so that the tensile stress is uniform throughout. In this paper I provide a sketch of the lives and achievements of Gilbert and Telford, and of their interaction over the Menai Bridge. There follows a commentary on Gilbert's 1826 paper, and on his two related publications; and a brief sketch of the earlier history of the catenary. I then describe the development of the suspension bridge up to the present time. Finally, I discuss relations between mathematical analysts and practical engineers. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society. PMID:25750153

An amateur's contribution to the design of Telford's Menai Suspension Bridge: a commentary on Gilbert (1826) 'On the mathematical theory of suspension bridges'.

PubMed

Calladine, C R

2015-04-13

Davies Gilbert's work on the catenary is notable on two counts. First, it influenced Thomas Telford in formulating his final design for the Menai Strait suspension bridge (1826); and second, it established for the first time the form of the 'catenary of equal strength'. The classical catenary is a uniform flexible chain or cable hanging freely under gravity between supports. The 'catenary of equal strength' is the form of a cable whose cross-sectional area is made proportional to the tension at each point, so that the tensile stress is uniform throughout. In this paper I provide a sketch of the lives and achievements of Gilbert and Telford, and of their interaction over the Menai Bridge. There follows a commentary on Gilbert's 1826 paper, and on his two related publications; and a brief sketch of the earlier history of the catenary. I then describe the development of the suspension bridge up to the present time. Finally, I discuss relations between mathematical analysts and practical engineers. This commentary was written to celebrate the 350th anniversary of the journal Philosophical Transactions of the Royal Society.

A combined study of heat and mass transfer in an infant incubator with an overhead screen.

PubMed

Ginalski, Maciej K; Nowak, Andrzej J; Wrobel, Luiz C

2007-06-01

The main objective of this study is to investigate the major physical processes taking place inside an infant incubator, before and after modifications have been made to its interior chamber. The modification involves the addition of an overhead screen to decrease radiation heat losses from the infant placed inside the incubator. The present study investigates the effect of these modifications on the convective heat flux from the infant's body to the surrounding environment inside the incubator. A combined analysis of airflow and heat transfer due to conduction, convection, radiation and evaporation has been performed, in order to calculate the temperature and velocity fields inside the incubator before and after the design modification. Due to the geometrical complexity of the model, computer-aided design (CAD) applications were used to generate a computer-based model. All numerical calculations have been performed using the commercial computational fluid dynamics (CFD) package FLUENT, together with in-house routines used for managing purposes and user-defined functions (UDFs) which extend the basic solver capabilities. Numerical calculations have been performed for three different air inlet temperatures: 32, 34 and 36 degrees C. The study shows a decrease of the radiative and convective heat losses when the overhead screen is present. The results obtained were numerically verified as well as compared with results available in the literature from investigations of dry heat losses from infant manikins.

Overhead View of Area Surrounding Pathfinder

NASA Technical Reports Server (NTRS)

1997-01-01

Overhead view of the area surrounding the Pathfinder lander illustrating the Sojourner traverse. Red rectangles are rover positions at the end of sols 1-30. Locations of soil mechanics experiments, wheel abrasion experiments, and APXS measurements are shown. The A numbers refer to APXS measurements as discussed in the paper by Rieder et al. (p. 1770, Science Magazine, see image note). Coordinates are given in the LL frame.

The photorealistic, interactive, three-dimensional virtual reality (VR) terrain models were created from IMP images using a software package developed for Pathfinder by C. Stoker et al. as a participating science project. By matching features in the left and right camera, an automated machine vision algorithm produced dense range maps of the nearfield, which were projected into a three-dimensional model as a connected polygonal mesh. Distance and angle measurements can be made on features viewed in the model using a mouse-driven three-dimensional cursor and a point-and-click interface. The VR model also incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. As the rover moved, graphical models of the rover were added for each position that could be uniquely determined using stereo images of the rover taken by the IMP. Images taken by the rover were projected into the model as two-dimensional 'billboards' to show the proper perspective of these images.

NOTE: original caption as published in Science Magazine

Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

Analyzing checkpointing trends for applications on the IBM Blue Gene/P system.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naik, H.; Gupta, R.; Beckman, P.

Current petascale systems have tens of thousands of hardware components and complex system software stacks, which increase the probability of faults occurring during the lifetime of a process. Checkpointing has been a popular method of providing fault tolerance in high-end systems. While considerable research has been done to optimize checkpointing, in practice the method still involves a high-cost overhead for users. In this paper, we study the checkpointing overhead seen by applications running on leadership-class machines such as the IBM Blue Gene/P at Argonne National Laboratory. We study various applications and design a methodology to assist users in understanding andmore » choosing checkpointing frequency and reducing the overhead incurred. In particular, we study three popular applications -- the Grid-Based Projector-Augmented Wave application, the Carr-Parrinello Molecular Dynamics application, and a Nek5000 computational fluid dynamics application -- and analyze their memory usage and possible checkpointing trends on 32,768 processors of the Blue Gene/P system.« less

Effects of Water Sprinklers on the Performance of Low Level AFFF Aircraft Hangar Fire Suppression Systems

DTIC Science & Technology

2000-05-22

AFFF fire suppression system. The combined overhead water-only sprinkler and low level AFFF system is being considered as a new protection scheme for...performance of a low level system during AFFF discharge (4.0 Lpm/sq m (0.1 gpm/sq ft)). Based on the results of these tests, the design criteria for...Navy hangar protection may be revised to incorporate AFFF application from only the low level system, combined with overhead closed-head guide response water sprinklers.

Effect of shoulder taping on maximum shoulder external and internal rotation range in uninjured and previously injured overhead athletes during a seated throw.

PubMed

McConnell, Jenny; Donnelly, Cyril; Hamner, Samuel; Dunne, James; Besier, Thor

2011-09-01

The purpose of our study was to investigate whether shoulder taping affects shoulder kinematics in injured and previously injured overhead athletes during a seated throw. Twenty-six overhead college athletes threw a handball three times with and without tape, while seated on a chair. An 8-camera Vicon Motion Capture system recorded markers placed on the upper limb and trunk during each of the throwing conditions. Scaled musculoskeletal models of the upper limb were created using OpenSim and inverse kinematics used to obtain relevant joint angles. Shoulder taping had no main effect on external (ER) and internal (IR) rotation range (ROM) of the shoulder, but a significant interaction effect was found (p = 0.003 and 0.02, respectively), depending on previous injury status, whereby both the ER and IR ROM of the shoulder in the group of previously injured athletes decreased when taped (143-138° and 54-51°, respectively), but increased in the group who had never been injured (131-135° and 42-44°, respectively). Maximum abduction range and ball velocity were not affected by the application of shoulder taping, regardless of previous injury status. Thus, application of shoulder taping has a differential effect on maximum shoulder ER and IR ROM during throwing depending on previous injury status. These findings have implications for returning athletes to sport after injury and for screening athletes at risk of injury. Copyright © 2011 Orthopaedic Research Society.

Inexpensive, rapid prototyping of microfluidic devices using overhead transparencies and a laser print, cut and laminate fabrication method.

PubMed

Thompson, Brandon L; Ouyang, Yiwen; Duarte, Gabriela R M; Carrilho, Emanuel; Krauss, Shannon T; Landers, James P

2015-06-01

We describe a technique for fabricating microfluidic devices with complex multilayer architectures using a laser printer, a CO2 laser cutter, an office laminator and common overhead transparencies as a printable substrate via a laser print, cut and laminate (PCL) methodology. The printer toner serves three functions: (i) it defines the microfluidic architecture, which is printed on the overhead transparencies; (ii) it acts as the adhesive agent for the bonding of multiple transparency layers; and (iii) it provides, in its unmodified state, printable, hydrophobic 'valves' for fluidic flow control. By using common graphics software, e.g., CorelDRAW or AutoCAD, the protocol produces microfluidic devices with a design-to-device time of ∼40 min. Devices of any shape can be generated for an array of multistep assays, with colorimetric detection of molecular species ranging from small molecules to proteins. Channels with varying depths can be formed using multiple transparency layers in which a CO2 laser is used to remove the polyester from the channel sections of the internal layers. The simplicity of the protocol, availability of the equipment and substrate and cost-effective nature of the process make microfluidic devices available to those who might benefit most from expedited, microscale chemistry.

Simulation of wear in overhead current collection systems

NASA Astrophysics Data System (ADS)

Klapas, D.; Benson, F. A.; Hackam, R.

1985-09-01

Apparatus have been designed to simulate the wear from conductors in a railway current collection system. The main features of the wear machine include a continuous monitoring of the strip wear, strip traversing, and dwell-time test facilities for the investigation of oxidational wear on a copper disk, simulating the contact wire. Disk wear is measured in situ by the spherical indentations method. Typical results of the specific wear rate are also presented to demonstrate the capability of the apparatus.

Scheduling for energy and reliability management on multiprocessor real-time systems

NASA Astrophysics Data System (ADS)

Qi, Xuan

Scheduling algorithms for multiprocessor real-time systems have been studied for years with many well-recognized algorithms proposed. However, it is still an evolving research area and many problems remain open due to their intrinsic complexities. With the emergence of multicore processors, it is necessary to re-investigate the scheduling problems and design/develop efficient algorithms for better system utilization, low scheduling overhead, high energy efficiency, and better system reliability. Focusing cluster schedulings with optimal global schedulers, we study the utilization bound and scheduling overhead for a class of cluster-optimal schedulers. Then, taking energy/power consumption into consideration, we developed energy-efficient scheduling algorithms for real-time systems, especially for the proliferating embedded systems with limited energy budget. As the commonly deployed energy-saving technique (e.g. dynamic voltage frequency scaling (DVFS)) will significantly affect system reliability, we study schedulers that have intelligent mechanisms to recuperate system reliability to satisfy the quality assurance requirements. Extensive simulation is conducted to evaluate the performance of the proposed algorithms on reduction of scheduling overhead, energy saving, and reliability improvement. The simulation results show that the proposed reliability-aware power management schemes could preserve the system reliability while still achieving substantial energy saving.

Cogeneration Systems.

DTIC Science & Technology

1980-06-01

43 3000 TYPICAL MID-1978 COSTS, all overhead included 2000- Type of System: Double alkali flue gas desulfurization plus baghouse particulate removal...Figures 5, 6, and 8 also provide cost estimating data for oil- and natural gas -fired steam turbine systems. Figure 5 shows the steam- generating station of...to the ownership and operation of the system. For systems burning oil or natural gas , fuel will typically constitute 65-90% of the total life cycle

Clouds Sailing Overhead on Mars, Unenhanced

NASA Image and Video Library

2017-08-09

Wispy clouds float across the Martian sky in this accelerated sequence of images from NASA's Curiosity Mars rover. The rover's Navigation Camera (Navcam) took these eight images over a span of four minutes early in the morning of the mission's 1,758th Martian day, or sol (July 17, 2017), aiming nearly straight overhead. This sequence uses raw images, which include a bright ring around the center of the frame that is an artifact of sunlight striking the camera lens even though the Sun is not in the shot. A processed version removing that artifact and emphasizing changes between images is also available. The clouds resemble Earth's cirrus clouds, which are ice crystals at high altitudes. These Martian clouds are likely composed of crystals of water ice that condense onto dust grains in the cold Martian atmosphere. Cirrus wisps appear as ice crystals fall and evaporate in patterns known as "fall streaks" or "mare's tails." Such patterns have been seen before at high latitudes on Mars, for instance by the Phoenix Mars Lander in 2008, and seasonally nearer the equator, for instance by the Opportunity rover. However, Curiosity has not previously observed such clouds so clearly visible from the rover's study area about five degrees south of the equator. The Hubble Space Telescope and spacecraft orbiting Mars have observed a band of clouds to appear near the Martian equator around the time of the Martian year when the planet is farthest from the Sun. With a more elliptical orbit than Earth's, Mars experiences more annual variation than Earth in its distance from the Sun. The most distant point in an orbit around the Sun is called the aphelion. The near-equatorial Martian cloud pattern observed at that time of year is called the "aphelion cloud belt." These new images from Curiosity were taken about two months before aphelion, but the morning clouds observed may be an early stage of the aphelion cloud belt. An animation is available at https

Quantifying acromiohumeral distance in overhead athletes with glenohumeral internal rotation loss and the influence of a stretching program.

PubMed

Maenhout, Annelies; Van Eessel, Valerie; Van Dyck, Lieselot; Vanraes, Aagje; Cools, Ann

2012-09-01

Loss of internal rotation range of motion (ROM) on the dominant side is well documented in athletes performing overhead sports activity. This altered motion pattern has been shown to change glenohumeral and scapular kinematics. This could compromise the subacromial space and explain the association between glenohumeral internal rotation deficit (GIRD) and subacromial impingement. First, to quantify acromiohumeral distance (AHD) and compare between the dominant and nondominant side in overhead athletes with GIRD of more than 15°. Second, to investigate the effect of a sleeper stretch program on ROM and AHD. Controlled laboratory study. Range of motion was measured with a digital inclinometer and AHD was measured with ultrasound in 62 overhead athletes with GIRD (>15°) at baseline. Differences between sides were analyzed. Athletes were randomly allocated to the stretch (n = 30) or control group (n = 32). The stretch group performed a 6-week sleeper stretch program on the dominant side. Change of range of motion and AHD were measured and analyzed in both groups after 6 weeks. The dominant side showed a significant internal rotation deficit (-24.7° ± 6.3°) and horizontal adduction deficit (-11.8° ± 7.4°) and the dominant side AHD was significantly smaller with the arm at neutral (-0.4 ± 0.6 mm) and at 45° (-0.5 ± 0.8 mm) and 60° (-0.6 ± 0.7 mm) of active abduction compared with the nondominant side. After stretching, significant increase of internal rotation (+13.5° ± 0.8°), horizontal adduction (+10.6° ± 0.9°) ROM and AHD (+0.5 to +0.6mm) was observed at the dominant side of the stretch group compared with prestretching measurements. No significant change of AHD was seen in the nondominant side of the stretch group and in both sides of the control group. The AHD, a 2-dimensional measure for subacromial space, was found to be smaller on the dominant side in athletes with GIRD and was found to increase after a 6-week sleeper stretch program. These

Advanced Distributed Simulation Technology Advanced Rotary Wing Aircraft. System/Segment Specification. Volume 1. Simulation System Module

DTIC Science & Technology

1994-03-31

overhead water sprinklers in enclosed personnel areas not already protected by existing facility fire suppression systems. Sprinkler systems shall not...facilitate future changes and updates to remain current with the application aircraft. 3.4.4 Availabilit . The ARWA SS shall be designed and constructed to

Customized overhead cranes for installation of India's largest 3.6m optical telescope at Devasthal, Nainital, India

NASA Astrophysics Data System (ADS)

Bangia, Tarun; Yadava, Shobhit; Kumar, Brijesh; Ghanti, A. S.; Hardikar, P. M.

2016-07-01

India's largest 3.6 m aperture optical telescope facility has been recently established at Devasthal site by Aryabhatta Research Institute of Observation Sciences (ARIES), an autonomous Institute under Department of Science and Technology, Government of India. The telescope is equipped with active optics and it is designed to be used for seeinglimited observations at visible and near-infrared wavelengths. A steel building with rotating cylindrical steel Dome was erected to house 3.6m telescope and its accessories at hilltop of Devasthal site. Customized cranes were essentially required inside the building as there were space constraints around the telescope building for operating big external heavy duty cranes from outside, transportation constraints in route for bringing heavy weight cranes, altitude of observatory, and sharp bends etc. to site. To meet the challenge of telescope installation from inside the telescope building by lifting components through its hatch, two Single Girder cranes and two Under Slung cranes of 10 MT capacity each were specifically designed and developed. All the four overhead cranes were custom built to achieve the goal of handling telescope mirror and its various components during installation and assembly. Overhead cranes were installed in limited available space inside the building and tested as per IS 3177. Cranes were equipped with many features like VVVFD compatibility, provision for tandem operation, digital load display, anti-collision mechanism, electrical interlocks, radio remote, low hook height and compact carriage etc. for telescope integration at site.

A TOTP-Based Enhanced Route Optimization Procedure for Mobile IPv6 to Reduce Handover Delay and Signalling Overhead

PubMed Central

Shah, Peer Azmat; Hasbullah, Halabi B.; Lawal, Ibrahim A.; Aminu Mu'azu, Abubakar; Tang Jung, Low

2014-01-01

Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node's reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node's compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6's Return-Routability-based Route Optimization (RR-RO). PMID:24688398

A TOTP-based enhanced route optimization procedure for mobile IPv6 to reduce handover delay and signalling overhead.

PubMed

Shah, Peer Azmat; Hasbullah, Halabi B; Lawal, Ibrahim A; Aminu Mu'azu, Abubakar; Tang Jung, Low

2014-01-01

Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node's reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node's compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6's Return-Routability-based Route Optimization (RR-RO).

Characterization Results for the March 2016 H-Tank Farm 2H Evaporator Overhead Samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholson, J. C.

This report contains the radioanalytical results of the 2H evaporator overhead sample received at SRNL on March 16, 2016. Specifically, concentrations of 137Cs, 90Sr, and 129I are reported and compared to the corresponding Waste Acceptance Criteria (WAC) limits of the Effluent Treatment Project (ETP) Waste Water Collection Tank (WWCT) (rev. 6). All of the radionuclide concentrations in the sample were found to be in compliance with the ETP WAC limits. Revision 1 of this document corrects the cumulative beta count initially reported for 90Sr content with the sole 90Sr count obtained after recharacterization of the sample. The initial data wasmore » found to be a cumulative beta count rather than the 90Sr count requested.« less

Lightweight Monorail Transport System

NASA Technical Reports Server (NTRS)

Weir, Harold F.; Wood, Kenneth E.; Strecker, Myron T.

1987-01-01

Report proposes monorail transportation system for zero-gravity environment. System carries materials and parts between locations on space station. Includes tubular rails instead of open channels usually found in overhead conveyor systems. Since resistance to torque of closed tube greater than that of open channel for same amount of material, tubular monorail designed for higher loads or for greater spacing between support points.

Overhead spine arch analysis of dairy cows from three-dimensional video

NASA Astrophysics Data System (ADS)

Abdul Jabbar, K.; Hansen, M. F.; Smith, M. L.; Smith, L. N.

2017-02-01

We present a spine arch analysis method in dairy cows using overhead 3D video data. This method is aimed for early stage lameness detection. That is important in order to allow early treatment; and thus, reduce the animal suffering and minimize the high forecasted financial losses, caused by lameness. Our physical data collection setup is non-intrusive, covert and designed to allow full automation; therefore, it could be implemented on a large scale or daily basis with high accuracy. We track the animal's spine using shape index and curvedness measure from the 3D surface as she walks freely under the 3D camera. Our spinal analysis focuses on the thoracic vertebrae region, where we found most of the arching caused by lameness. A cubic polynomial is fitted to analyze the arch and estimate the locomotion soundness. We have found more accurate results by eliminating the regular neck/head movements' effect from the arch. Using 22-cow data set, we are able to achieve an early stage lameness detection accuracy of 95.4%.

46 CFR 108.411 - Smoke detection system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Smoke detection system. 108.411 Section 108.411 Shipping... EQUIPMENT Fire Extinguishing Systems § 108.411 Smoke detection system. Each smoke accumulator in a smoke detection system must be located on the overhead of the compartment protected by the system in a location...

Results of arthroscopic repair of type II superior labral anterior posterior lesions in overhead athletes: assessment of return to preinjury playing level and satisfaction.

PubMed

Neuman, Brian J; Boisvert, C Brittany; Reiter, Brian; Lawson, Kevin; Ciccotti, Michael G; Cohen, Steven B

2011-09-01

The majority of the literature on surgical outcomes of superior labral anterior posterior (SLAP) repairs has focused on short-term follow-up of 1 to 2 years, not allowing adequate time for full rehabilitation and return to maximum level of competition for all types of athletes. Also, previous studies have concentrated on using questionnaires that primarily evaluate patients' activities of daily living, which do not focus on sport-specific performance. To determine the midterm results of type II SLAP repairs in overhead athletes, focusing primarily on athletic performance as well as activities of daily living. Case series; Level of evidence, 4. A retrospective review of 30 overhead athletes, who underwent an arthroscopic superior labral repair for a symptomatic type II SLAP tear between 2002 and 2007, was performed. Our study population included 22 male and 8 female patients with a mean age at the time of surgery of 24 years. Twenty-one patients participated in baseball or softball, and the remainder of patients were involved in javelin throwing or tennis. The average follow-up was 3.5 years. The outcome of treatment was evaluated using the American Shoulder and Elbow Society (ASES) scoring system, assessing activities of daily living, and the Kerlan-Jobe Orthopaedic Clinic Shoulder and Elbow (KJOC) score, assessing sport-specific performance. In addition, the length of time to return to sport and the degree of successful performance were evaluated. Repairs resulted in ASES scores comparable with those from prior published studies (average ASES score, 87.9). The KJOC score averaged 73.6. The athletes' perception was that they returned to approximately 84.1% of their preinjury level of function with a mean time to return to play of 11.7 months. There was a significant drop in the ASES to KJOC score for the baseball/softball players (87.9 ± 14.94 and 72 ± 19.24, respectively; P = .006). Patients reported an overall satisfaction rate of 93.3% with the procedure, with

Adaptive neuro fuzzy system for modelling and prediction of distance pantograph catenary in railway transportation

NASA Astrophysics Data System (ADS)

Panoiu, M.; Panoiu, C.; Lihaciu, I. L.

2018-01-01

This research presents an adaptive neuro-fuzzy system which is used in the prediction of the distance between the pantograph and contact line of the electrical locomotives used in railway transportation. In railway transportation any incident that occurs in the electrical system can have major negative effects: traffic interrupts, equipment destroying. Therefore, a prediction as good as possible of such situations is very useful. In the paper was analyzing the possibility of modeling and prediction the variation of the distance between the pantograph and the contact line using intelligent techniques

Clouds Sailing Overhead on Mars, Enhanced

NASA Image and Video Library

2017-08-09

Wispy clouds float across the Martian sky in this accelerated sequence of enhanced images from NASA's Curiosity Mars rover. The rover's Navigation Camera (Navcam) took these eight images over a span of four minutes early in the morning of the mission's 1,758th Martian day, or sol (July 17, 2017), aiming nearly straight overhead. They have been processed by first making a "flat field' adjustment for known differences in sensitivity among pixels and correcting for camera artifacts due to light reflecting within the camera, and then generating an "average" of all the frames and subtracting that average from each frame. This subtraction results in emphasizing any changes due to movement or lighting. The clouds are also visible, though fainter, in a raw image sequence from these same observations. On the same Martian morning, Curiosity also observed clouds near the southern horizon. The clouds resemble Earth's cirrus clouds, which are ice crystals at high altitudes. These Martian clouds are likely composed of crystals of water ice that condense onto dust grains in the cold Martian atmosphere. Cirrus wisps appear as ice crystals fall and evaporate in patterns known as "fall streaks" or "mare's tails." Such patterns have been seen before at high latitudes on Mars, for instance by the Phoenix Mars Lander in 2008, and seasonally nearer the equator, for instance by the Opportunity rover. However, Curiosity has not previously observed such clouds so clearly visible from the rover's study area about five degrees south of the equator. The Hubble Space Telescope and spacecraft orbiting Mars have observed a band of clouds to appear near the Martian equator around the time of the Martian year when the planet is farthest from the Sun. With a more elliptical orbit than Earth's, Mars experiences more annual variation than Earth in its distance from the Sun. The most distant point in an orbit around the Sun is called the aphelion. The near-equatorial Martian cloud pattern observed at

A lightweight sensor network management system design

USGS Publications Warehouse

Yuan, F.; Song, W.-Z.; Peterson, N.; Peng, Y.; Wang, L.; Shirazi, B.; LaHusen, R.

2008-01-01

In this paper, we propose a lightweight and transparent management framework for TinyOS sensor networks, called L-SNMS, which minimizes the overhead of management functions, including memory usage overhead, network traffic overhead, and integration overhead. We accomplish this by making L-SNMS virtually transparent to other applications hence requiring minimal integration. The proposed L-SNMS framework has been successfully tested on various sensor node platforms, including TelosB, MICAz and IMote2. ?? 2008 IEEE.

Kepler Planetary Systems in Motion Artist Concept

NASA Image and Video Library

2012-01-26

This artist concept shows an overhead view of the orbital position of the planets in systems with multiple transiting planets discovered by NASA Kepler mission. All the colored planets have been verified.

A neural network-based input shaping for swing suppression of an overhead crane under payload hoisting and mass variations

NASA Astrophysics Data System (ADS)

Ramli, Liyana; Mohamed, Z.; Jaafar, H. I.

2018-07-01

This paper proposes an improved input shaping for minimising payload swing of an overhead crane with payload hoisting and payload mass variations. A real time unity magnitude zero vibration (UMZV) shaper is designed by using an artificial neural network trained by particle swarm optimisation. The proposed technique could predict and directly update the shaper's parameters in real time to handle the effects of time-varying parameters during the crane operation with hoisting. To evaluate the performances of the proposed method, experiments are conducted on a laboratory overhead crane with a payload hoisting, different payload masses and two different crane motions. The superiority of the proposed method is confirmed by reductions of at least 38.9% and 91.3% in the overall and residual swing responses, respectively over a UMZV shaper designed using an average operating frequency and a robust shaper namely Zero Vibration Derivative-Derivative (ZVDD). The proposed method also demonstrates a significant residual swing suppression as compared to a ZVDD shaper designed based on varying frequency. In addition, the significant reductions are achieved with a less shaper duration resulting in a satisfactory speed of response. It is envisaged that the proposed method can be used for designing effective input shapers for payload swing suppression of a crane with time-varying parameters and for a crane that employ finite actuation states.

Comparing methodologies for the allocation of overhead and capital costs to hospital services.

PubMed

Tan, Siok Swan; van Ineveld, Bastianus Martinus; Redekop, William Ken; Hakkaart-van Roijen, Leona

2009-06-01

Typically, little consideration is given to the allocation of indirect costs (overheads and capital) to hospital services, compared to the allocation of direct costs. Weighted service allocation is believed to provide the most accurate indirect cost estimation, but the method is time consuming. To determine whether hourly rate, inpatient day, and marginal mark-up allocation are reliable alternatives for weighted service allocation. The cost approaches were compared independently for appendectomy, hip replacement, cataract, and stroke in representative general hospitals in The Netherlands for 2005. Hourly rate allocation and inpatient day allocation produce estimates that are not significantly different from weighted service allocation. Hourly rate allocation may be a strong alternative to weighted service allocation for hospital services with a relatively short inpatient stay. The use of inpatient day allocation would likely most closely reflect the indirect cost estimates obtained by the weighted service method.

Headgear Accessories Classification Using an Overhead Depth Sensor

PubMed Central

Luna, Carlos A.; Marron-Romera, Marta; Mazo, Manuel; Luengo-Sanchez, Sara; Macho-Pedroso, Roberto

2017-01-01

In this paper, we address the generation of semantic labels describing the headgear accessories carried out by people in a scene under surveillance, only using depth information obtained from a Time-of-Flight (ToF) camera placed in an overhead position. We propose a new method for headgear accessories classification based on the design of a robust processing strategy that includes the estimation of a meaningful feature vector that provides the relevant information about the people’s head and shoulder areas. This paper includes a detailed description of the proposed algorithmic approach, and the results obtained in tests with persons with and without headgear accessories, and with different types of hats and caps. In order to evaluate the proposal, a wide experimental validation has been carried out on a fully labeled database (that has been made available to the scientific community), including a broad variety of people and headgear accessories. For the validation, three different levels of detail have been defined, considering a different number of classes: the first level only includes two classes (hat/cap, and no hat/cap), the second one considers three classes (hat, cap and no hat/cap), and the last one includes the full class set with the five classes (no hat/cap, cap, small size hat, medium size hat, and large size hat). The achieved performance is satisfactory in every case: the average classification rates for the first level reaches 95.25%, for the second one is 92.34%, and for the full class set equals 84.60%. In addition, the online stage processing time is 5.75 ms per frame in a standard PC, thus allowing for real-time operation. PMID:28796177

Investigation of lunar base thermal control system options

NASA Technical Reports Server (NTRS)

Ewart, Michael K.

1993-01-01

Long duration human exploration missions to the Moon will require active thermal control systems which have not previously been used in space. The two technologies which are most promising for long term lunar base thermal control are heat pumps and radiator shades. Recent trade-off studies at the Johnson Space Center have focused development efforts on the most promising heat pump and radiator shade technologies. Since these technologies are in the early stages of development and many parameters used in the study are not well defined, a parametric study was done to test the sensitivity to each assumption. The primary comparison factor in these studies was the total mass system, with power requirements included in the form of a mass penalty for power. Heat pump technologies considered were thermally driven heat pumps such as metal hydride, complex compound, absorption and zeolite. Also considered were electrically driven Stirling and vapor compression heat pumps. Radiator shade concepts considered included step shaped, V-shaped and parabolic (or catenary) shades and ground covers. A further trade study compared the masses of heat pump and radiator shade systems.

A STATE DEMONSTRATION AND EVALUATION IN DEVELOPING PILOT OVERHEAD TRANSPARENCIES FOR THE SUBJECT AREAS OF SECONDARY SCIENCE, MATHEMATICS, ENGLISH, MODERN FOREIGN LANGUAGES, AND GEOGRAPHY.

ERIC Educational Resources Information Center

KINNIELL, WILLIAM T.; AND OTHERS

A DEMONSTRATION PROGRAM WAS UNDERTAKEN FOR THE PURPOSE OF SHOWING HOW A STATE DEPARTMENT OF EDUCATION CAN UTILIZE ITS RESOURCES AND SUBJECT MATTER SPECIALISTS IN DEVELOPING OVERHEAD TRANSPARENCIES TO IMPLEMENT SECONDARY SCHOOL CURRICULUM IN THE STATE. SUBJECT SPECIALISTS (26) REPRESENTING 10 COURSE FIELDS WERE BROUGHT TOGETHER AT THE BEGINNING OF…

Optimized Temporal Monitors for SystemC

NASA Technical Reports Server (NTRS)

Tabakov, Deian; Rozier, Kristin Y.; Vardi, Moshe Y.

2012-01-01

SystemC is a modeling language built as an extension of C++. Its growing popularity and the increasing complexity of designs have motivated research efforts aimed at the verification of SystemC models using assertion-based verification (ABV), where the designer asserts properties that capture the design intent in a formal language such as PSL or SVA. The model then can be verified against the properties using runtime or formal verification techniques. In this paper we focus on automated generation of runtime monitors from temporal properties. Our focus is on minimizing runtime overhead, rather than monitor size or monitor-generation time. We identify four issues in monitor generation: state minimization, alphabet representation, alphabet minimization, and monitor encoding. We conduct extensive experimentation and identify a combination of settings that offers the best performance in terms of runtime overhead.

Evaluating Effects of H2O and overhead O3 on Global Mean Tropospheric OH Concentration

NASA Technical Reports Server (NTRS)

Nicely, Julie M.; Salawitch, R.J.; Canty, T.; Lang, Chang; Duncan, Bryan; Liang, Qing; Oman, Luke David; Stolarski, Richard S.; Waugh, Darryn

2012-01-01

The oxidizing capacity of the troposphere is controlled, to a large extent, by the abundance of hydroxyl radical (OH). The global mean concentration of OH, [OH]GLOBAL, inferred from measurements of methyl chloroform, has remained relatively constant during the past several decades, despite rising levels of CH4 that should have led to a steady decline. Here we examine other factors that may have affected [OH]GLOBAL, such as the overhead burden of stratospheric O3 and tropospheric H2O, using global OH fields from the GEOS-CHEM Chemistry-Climate Model. Our analysis suggests these factors may have contributed a positive trend to [OH]GLOBAL large enough to counter the decrease due to CH4.

Development and evaluation of a hand tracker using depth images captured from an overhead perspective.

PubMed

Czarnuch, Stephen; Mihailidis, Alex

2015-03-27

We present the development and evaluation of a robust hand tracker based on single overhead depth images for use in the COACH, an assistive technology for people with dementia. The new hand tracker was designed to overcome limitations experienced by the COACH in previous clinical trials. We train a random decision forest classifier using ∼5000 manually labeled, unbalanced, training images. Hand positions from the classifier are translated into task actions based on proximity to environmental objects. Tracker performance is evaluated using a large set of ∼24 000 manually labeled images captured from 41 participants in a fully-functional washroom, and compared to the system's previous colour-based hand tracker. Precision and recall were 0.994 and 0.938 for the depth tracker compared to 0.981 and 0.822 for the colour tracker with the current data, and 0.989 and 0.466 in the previous study. The improved tracking performance supports integration of the depth-based tracker into the COACH toward unsupervised, real-world trials. Implications for Rehabilitation The COACH is an intelligent assistive technology that can enable people with cognitive disabilities to stay at home longer, supporting the concept of aging-in-place. Automated prompting systems, a type of intelligent assistive technology, can help to support the independent completion of activities of daily living, increasing the independence of people with cognitive disabilities while reducing the burden of care experienced by caregivers. Robust motion tracking using depth imaging supports the development of intelligent assistive technologies like the COACH. Robust motion tracking also has application to other forms of assistive technologies including gaming, human-computer interaction and automated assessments.

49 CFR 611.105 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... public transportation and other high occupancy vehicles, or uses a fixed catenary system and a right of... rail, commuter rail, automated guideway transit, people movers, ferry boat service, and fixed-guideway facilities for buses (such as bus rapid transit) and other high occupancy vehicles. A new fixed guideway...

49 CFR 611.105 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... public transportation and other high occupancy vehicles, or uses a fixed catenary system and a right of... rail, commuter rail, automated guideway transit, people movers, ferry boat service, and fixed-guideway facilities for buses (such as bus rapid transit) and other high occupancy vehicles. A new fixed guideway...

A New Method for Interfacing Unsuited Subjects to Overhead Suspension Partial Gravity Simulators

NASA Technical Reports Server (NTRS)

Norcross, Jason R.; Chappell, Steve; Cowley, Matthew S.; Harvill, Lauren; Gernhardt, Michael L.

2010-01-01

The purpose of performing unsuited testing as part of a reduced gravity extravehicular (EVA) suited human performance research program is to define baseline performance. These results are then coupled with suited test results to evaluate how the suit system affects human performance at reduced gravity. The primary drawback to this approach is that previous studies used notably different systems to interface suited and unsuited subjects to overhead-suspension, partial-gravity simulators. A spreader bar (SB) assembly previously used for unsuited tests allowed limited pitch and roll of the subject, whereas the gimbal for suited tests allowed more pitch and roll, although the mass distribution led to large moments of inertia in the yaw axis. It is hypothesized that use of the same methods for offload of both unsuited and suited subjects is needed to make meaningful comparisons. A new gimbal (GIM) was designed with the idea that it could function with both suited and unsuited subjects. GIM was designed to minimize mass and moments of inertia and to be adjustable to co-locate the 3 axes of rotation with the subject s center of gravity. OBJECTIVE: To evaluate human performance differences between SB and GIM. METHODS: Ten unsuited subjects were off-loaded to 1/6-g using both interfaces. Subjects completed tasks including overground and treadmill ambulation, picking up objects, shoveling, postural stability, range of motion testing, and recovery from the kneeling and prone positions. Metabolic, biomechanical, and/or subjective data were collected based on task. RESULTS: Initial analyses suggest that subjects completed all tasks with lower levels of compensation and a more terrestrial approach to movement when suspended via GIM. With SB, subjects were not able to fall or get into a prone position and had increased difficulty both retrieving objects off the floor and with overground ambulation, especially at gait initiation, because they were unable to bend their torso. GIM

A New Method for Interfacing Unsuited Subjects to Overhead Suspension Partial Gravity Simulators

NASA Technical Reports Server (NTRS)

Norcross, Jason; Gernhardt, Michael; Chappell, Steve; Cowley, Matt

2011-01-01

The purpose of performing unsuited testing as part of a reduced gravity extravehicular (EVA) suited human performance research program is to define baseline performance. These results are then coupled with suited test results to evaluate how the suit system affects human performance at reduced gravity. The primary drawback to this approach is that previous studies used notably different systems to interface suited and unsuited subjects to overhead-suspension, partial-gravity simulators. A spreader bar (SB) assembly previously used for unsuited tests allowed limited pitch and roll of the subject, whereas the gimbal for suited tests allowed more pitch and roll, although the mass distribution led to large moments of inertia in the yaw axis. It is hypothesized that use of the same methods for offload of both unsuited and suited subjects is needed to make meaningful comparisons. A new gimbal (GIM) was designed with the idea that it could function with both suited and unsuited subjects. GIM was designed to minimize mass and moments of inertia and to be adjustable to co-locate the 3 axes of rotation with the subject s center of gravity. OBJECTIVE: To evaluate human performance differences between SB and GIM. METHODS: Ten unsuited subjects were offloaded to 1/6-g using both interfaces. Subjects completed tasks including overground and treadmill ambulation, picking up objects, shoveling, postural stability, range of motion testing, and recovery from the kneeling and prone positions. Metabolic, biomechanical, and/or subjective data were collected based on task. RESULTS: Initial analyses suggest that subjects completed all tasks with lower levels of compensation and a more terrestrial approach to movement when suspended via GIM. With SB, subjects were not able to fall or get into a prone position and had increased difficulty both retrieving objects off the floor and with overground ambulation, especially at gait initiation, because they were unable to bend their torso. GIM

Runtime Performance Monitoring Tool for RTEMS System Software

NASA Astrophysics Data System (ADS)

Cho, B.; Kim, S.; Park, H.; Kim, H.; Choi, J.; Chae, D.; Lee, J.

2007-08-01

RTEMS is a commercial-grade real-time operating system that supports multi-processor computers. However, there are not many development tools for RTEMS. In this paper, we report new RTEMS-based runtime performance monitoring tool. We have implemented a light weight runtime monitoring task with an extension to the RTEMS APIs. Using our tool, software developers can verify various performance- related parameters during runtime. Our tool can be used during software development phase and in-orbit operation as well. Our implemented target agent is light weight and has small overhead using SpaceWire interface. Efforts to reduce overhead and to add other monitoring parameters are currently under research.

Smart patch integration development of compression connector structural health monitoring in overhead transmission lines

NASA Astrophysics Data System (ADS)

Wang, Hong; Wang, Jy-An J.; Ren, Fei; Chan, John

2016-04-01

Integration of smart patches into full-tension splice connectors in overhead power transmission lines was investigated. Lead zirconate titanate (PZT) -5A was used as a smart material and an aluminum beam was used as a host structure. Negative electrode termination was examined by using copper adhesive tape and direct bonding methods. Various commercial adhesives were studied for PZT integration onto the host structure. Aluminum beam specimens with integrated PZT smart patches were tested under thermal cycling at a temperature of 125°C, which is the higher-end temperature experienced by in-service aluminum conductor steel-reinforced cables. Electromechanical impedance (EMI) measurements were conducted at room temperature, and the root mean square deviation (RMSD) of the conductance signals was used to analyze the EMI data. It has been shown that the negative electrode method has an important effect on the performance of the integrated PZT. The PZT displayed more susceptibility to cracking when copper tape was used than when direct bonding was used. The reliability of PZT in direct bonding depended on the adhesives used in bonding layers. Although a hard alumina-based adhesive can lead to cracking of the PZT, a high-temperature epoxy with adequate flexibility, such as Duralco 4538D, can provide the desired performance under target thermal cycling conditions. The RMSD parameter can characterize conductance signatures effectively. It also was demonstrated that RMSD can be used to quantify the fatigue of the PZT integration system, although RMSD is used primarily as a damage index in monitoring structural health.

Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems.

PubMed

Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D

2016-07-25

In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems.

Mechanical design of NASA Ames Research Center vertical motion simulator

NASA Technical Reports Server (NTRS)

Engelbert, D. F.; Bakke, A. P.; Chargin, M. K.; Vallotton, W. C.

1976-01-01

NASA has designed and is constructing a new flight simulator with large vertical travel. Several aspects of the mechanical design of this Vertical Motion Simulator (VMS) are discussed, including the multiple rack and pinion vertical drive, a pneumatic equilibration system, and the friction-damped rigid link catenaries used as cable supports.

Increasing the reliability of the shutdown of 500 - 750-kV overhead lines equipped with shunt reactors in an unsuccessful three-phase automatic repeated closure cycle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuz'micheva, K. I.; Merzlyakov, A. S.; Fokin, G. G.

2013-05-15

The reasons for circuit-breaker failures during repeated disconnection of 500 - 750 kV overhead lines with shunt reactors in a cycle of unsuccessful three-phase automatic reconnection (TARC) are analyzed. Recommendations are made for increasing the operating reliability of power transmission lines with shunt reactors when there is unsuccessful reconnection.

Acute effects of scapular Kinesio Taping® on shoulder rotator strength, ROM and acromiohumeral distance in asymptomatic overhead athletes.

PubMed

Harput, Gulcan; Guney, Hande; Toprak, Ugur; Colakoglu, Filiz; Baltaci, Gul

2017-11-01

There is limited information in the literature that shows whether scapular taping has an effect on the acromiohumeral distance (AHD) and shoulder functions. The aim of this study was to investigate the acute effects of scapular Kinesio Taping® on shoulder internal rotation (IR) and external rotation (ER) strength, IR and ER range of motion (ROM) and AHD in asymptomatic overhead athletes. Forty-one volleyball athletes (24 men, 17 women; mean age: 16.1±1.5 years, body mass: 66.5±9.6 kg, body height: 179.6±8.4 cm, Body Mass Index: 20.5±2.3 kg/m2, time participating in overhead sports activity: 6.2±1.4 h/week, experience in sport: 4.1±2.4 years) were included in this study. Shoulder IR and ER ROM, total rotation ROM, AHD, shoulder isometric IR and ER strength and ER:IR strength ratio of the dominant side were tested before and after taping. Scapular taping increased the shoulder IR (P<0.001) and total ROM (P<0.001), AHD (P<0.001), shoulder IR (P=0.002) and ER (P=0.006) strength. ER ROM and ER:IR ratio did not change after taping (P=0.26, P=0.98, respectively). The results of this study suggest that scapular taping could be an effective method for enhancing the acromiohumeral distance, shoulder rotator strength and range of motion. Therefore, scapular taping could be recommended for not only in the asymptomatic athletes' shoulder exercise training but also in the prevention of subacromial impingement syndrome.

Effects of height and load weight on shoulder muscle work during overhead lifting task.

PubMed

Blache, Y; Desmoulins, L; Allard, P; Plamondon, A; Begon, M

2015-01-01

Few musculoskeletal models are available to assess shoulder deeper muscle demand during overhead lifting tasks. Our objective was to implement a musculoskeletal model to assess the effect of lifting height and load on shoulder muscle work. A musculoskeletal model scaled from 15 male subjects was used to calculate shoulder muscle work during six lifting tasks. Boxes containing three different loads (6, 12 and 18 kg) were lifted by the subjects from the waist to shoulder or eye level. After optimisation of the maximal isometric force of the model's muscles, the bio-fidelity of the model was improved by 19%. The latter was able to reproduce the subjects' lifting movements. Mechanical work of the rotator cuff muscles, upper trapezius and anterior deltoid was increased with lifting load and height augmentation. In conclusion, the use of a musculoskeletal model validated by electromyography enabled to evaluate the muscle demand of deep muscles during lifting tasks.

Feasibility study of a real-time operating system for a multichannel MPEG-4 encoder

NASA Astrophysics Data System (ADS)

Lehtoranta, Olli; Hamalainen, Timo D.

2005-03-01

Feasibility of DSP/BIOS real-time operating system for a multi-channel MPEG-4 encoder is studied. Performances of two MPEG-4 encoder implementations with and without the operating system are compared in terms of encoding frame rate and memory requirements. The effects of task switching frequency and number of parallel video channels to the encoding frame rate are measured. The research is carried out on a 200 MHz TMS320C6201 fixed point DSP using QCIF (176x144 pixels) video format. Compared to a traditional DSP implementation without an operating system, inclusion of DSP/BIOS reduces total system throughput only by 1 QCIF frames/s. The operating system has 6 KB data memory overhead and program memory requirement of 15.7 KB. Hence, the overhead is considered low enough for resource critical mobile video applications.

Reliability analysis of multicellular system architectures for low-cost satellites

NASA Astrophysics Data System (ADS)

Erlank, A. O.; Bridges, C. P.

2018-06-01

Multicellular system architectures are proposed as a solution to the problem of low reliability currently seen amongst small, low cost satellites. In a multicellular architecture, a set of independent k-out-of-n systems mimic the cells of a biological organism. In order to be beneficial, a multicellular architecture must provide more reliability per unit of overhead than traditional forms of redundancy. The overheads include power consumption, volume and mass. This paper describes the derivation of an analytical model for predicting a multicellular system's lifetime. The performance of such architectures is compared against that of several common forms of redundancy and proven to be beneficial under certain circumstances. In addition, the problem of peripheral interfaces and cross-strapping is investigated using a purpose-developed, multicellular simulation environment. Finally, two case studies are presented based on a prototype cell implementation, which demonstrate the feasibility of the proposed architecture.

Active Response Gravity Offload System

NASA Technical Reports Server (NTRS)

Valle, Paul; Dungan, Larry; Cunningham, Thomas; Lieberman, Asher; Poncia, Dina

2011-01-01

The Active Response Gravity Offload System (ARGOS) provides the ability to simulate with one system the gravity effect of planets, moons, comets, asteroids, and microgravity, where the gravity is less than Earth fs gravity. The system works by providing a constant force offload through an overhead hoist system and horizontal motion through a rail and trolley system. The facility covers a 20 by 40-ft (approximately equals 6.1 by 12.2m) horizontal area with 15 ft (approximately equals4.6 m) of lifting vertical range.

Logical Design of a Decision Support System to Forecast Technology, Prices and Costs for the National Communications System.

DTIC Science & Technology

1984-09-01

IN SOFTWARE DESIGN ......... .................... 39 P. PROCESS DESCRIPTIONS 43.............3 1. Model Euilding .............. 43 2. M1odel Management ... manager to model a wide variety of technology, price and cost situations without the associated overhead imposed by multiple application-specific systems...The Manager of the National Communications System (NCS) has been tasked by the National Security Telecommunications Policy of 3 August 1983 with

Measuring household consumption and waste in unmetered, intermittent piped water systems

NASA Astrophysics Data System (ADS)

Kumpel, Emily; Woelfle-Erskine, Cleo; Ray, Isha; Nelson, Kara L.

2017-01-01

Measurements of household water consumption are extremely difficult in intermittent water supply (IWS) regimes in low- and middle-income countries, where water is delivered for short durations, taps are shared, metering is limited, and household storage infrastructure varies widely. Nonetheless, consumption estimates are necessary for utilities to improve water delivery. We estimated household water use in Hubli-Dharwad, India, with a mixed-methods approach combining (limited) metered data, storage container inventories, and structured observations. We developed a typology of household water access according to infrastructure conditions based on the presence of an overhead storage tank and a shared tap. For households with overhead tanks, container measurements and metered data produced statistically similar consumption volumes; for households without overhead tanks, stored volumes underestimated consumption because of significant water use directly from the tap during delivery periods. Households that shared taps consumed much less water than those that did not. We used our water use calculations to estimate waste at the household level and in the distribution system. Very few households used 135 L/person/d, the Government of India design standard for urban systems. Most wasted little water even when unmetered, however, unaccounted-for water in the neighborhood distribution systems was around 50%. Thus, conservation efforts should target loss reduction in the network rather than at households.

Modelling of structural flexiblity in multibody railroad vehicle systems

NASA Astrophysics Data System (ADS)

Escalona, José L.; Sugiyama, Hiroyuki; Shabana, Ahmed A.

2013-07-01

This paper presents a review of recent research investigations on the computer modelling of flexible bodies in railroad vehicle systems. The paper will also discuss the influence of the structural flexibility of various components, including the wheelset, the truck frames, tracks, pantograph/catenary systems, and car bodies, on the dynamics of railroad vehicles. While several formulations and computer techniques for modelling structural flexibility are discussed in this paper, a special attention is paid to the floating frame of reference formulation which is widely used and leads to reduced-order finite-element models for flexible bodies by employing component modes synthesis techniques. Other formulations and numerical methods such as semi-analytical approaches, absolute nodal coordinate formulation, finite-segment method, boundary elements method, and discrete elements method are also discussed. This investigation is motivated by the fact that the structural flexibility can have a significant effect on the overall dynamics of railroad vehicles, ride comfort, vibration suppression and noise level reduction, lateral stability, track response to vehicle forces, stress analysis, wheel-rail contact forces, wear and crashworthiness.

Computation and Communication Evaluation of an Authentication Mechanism for Time-Triggered Networked Control Systems

PubMed Central

Martins, Goncalo; Moondra, Arul; Dubey, Abhishek; Bhattacharjee, Anirban; Koutsoukos, Xenofon D.

2016-01-01

In modern networked control applications, confidentiality and integrity are important features to address in order to prevent against attacks. Moreover, network control systems are a fundamental part of the communication components of current cyber-physical systems (e.g., automotive communications). Many networked control systems employ Time-Triggered (TT) architectures that provide mechanisms enabling the exchange of precise and synchronous messages. TT systems have computation and communication constraints, and with the aim to enable secure communications in the network, it is important to evaluate the computational and communication overhead of implementing secure communication mechanisms. This paper presents a comprehensive analysis and evaluation of the effects of adding a Hash-based Message Authentication (HMAC) to TT networked control systems. The contributions of the paper include (1) the analysis and experimental validation of the communication overhead, as well as a scalability analysis that utilizes the experimental result for both wired and wireless platforms and (2) an experimental evaluation of the computational overhead of HMAC based on a kernel-level Linux implementation. An automotive application is used as an example, and the results show that it is feasible to implement a secure communication mechanism without interfering with the existing automotive controller execution times. The methods and results of the paper can be used for evaluating the performance impact of security mechanisms and, thus, for the design of secure wired and wireless TT networked control systems. PMID:27463718

Lightning Protection System for Space Shuttle

NASA Technical Reports Server (NTRS)

1977-01-01

The suitability and cost effectiveness of using a lightning mast for the shuttle service and access tower (SSAT) similar to the type used for the Apollo Soyuz Test Project (ASTP) mobile launcher (ML) was evaluated. Topics covered include: (1) ASTP launch damage to mast, mast supports, grounded overhead wires, and the instrumentation system; (2) modifications required to permit reusing the ASTP mast on the SSAT; (3) comparative costing factors per launch over a 10 year period in repetitive maintenance and refurbishment of the existing and modified masts, mast supports, grounded overhead wires, and ground instrumentation required to sustain mechanical and electrical integrity of the masts; (4) effects of blast testing samples of the ASTP ML type mast (corrosion and electrical flashover); (5) comparison of damages from ASTP launch and from blast testing.

IMPROVING PROCEDURES FOR PRODUCING OVERHEAD TRANSPARENCIES WITH THE ULTIMATE AIM OF INCORPORATING THESE TECHNIQUES INTO THE DEVELOPMENT OF A REGIONAL CURRICULAR MATERIALS CENTER FOR VOCATIONAL EDUCATION. FINAL REPORT.

ERIC Educational Resources Information Center

JENSEN, ARTHUR K.

THE INVESTIGATION RESULTED IN THE PRODUCTION OF 88 LOW-COST OVERHEAD PROJECTION TRANSPARENCIES ON THE BASIC PRINCIPLES OF POWER TRANSMISSION IN AGRICULTURAL MACHINERY. DEVELOPING TECHNIQUES FOR OFFSET PRINTING ON PLASTIC REQUIRED OVERCOMING PROBLEMS OF STATIC ELECTRICITY, INK ADHESION, OFFSETTING, AND DRYING. MACHINERY, ENVIRONMENT, AND INK WERE…

Structural health monitoring of compression connectors for overhead transmission lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Hong; Wang, Jy-An John; Swindeman, Joseph P

Two-stage aluminum conductor steel-reinforced (ACSR) compression connectors are extensively used in US overhead transmission lines. The connectors are made by crimping a steel sleeve onto a steel core and an aluminum sleeve over aluminum conductive strands. The connectors are designed to operate at temperatures up to 125 C, but their performance is increasingly degrading because of overloading of lines. Currently, electric utilities conduct routine line inspections using thermal and electrical measurements. However, information about the structural integrity of connectors cannot be obtained. In this work, structural health monitoring (SHM) of compression connectors was studied using electromechanical impedance (EMI) analysis. Leadmore » zirconate titanate (PZT)-5A was identified as a smart material for SHM. A flexible high-temperature bonding layer was used to address challenges in PZT integration due to a significant difference in the coefficients of thermal expansion of PZT and the aluminum substrate. The steel joint on the steel core was investigated because it is responsible for the ultimate tensile strength of the connector. Tensile testing was used to create structural damage to the joint, or steel core pullout, and thermal cycling introduced additional structural perturbations. EMI measurements were conducted between the tests. The root mean square deviation (RMSD) of EMI was identified as a damage index. The use of steel joints has been shown to enable SHM under simulated conditions. The EMI signature is sensitive to variations in structural conditions. RMSD can be correlated to the structural health of a connector and has potential for use in the SHM and structural integrity evaluation.« less

Structural health monitoring of compression connectors for overhead transmission lines

NASA Astrophysics Data System (ADS)

Wang, Hong; Wang, Jy-An John; Swindeman, Joseph P.; Ren, Fei; Chan, John

2017-04-01

Two-stage aluminum conductor steel-reinforced (ACSR) compression connectors are extensively used in US overhead transmission lines. The connectors are made by crimping a steel sleeve onto a steel core and an aluminum sleeve over electrical conducting aluminum strands. The connectors are designed to operate at temperatures up to 125°C, but their performance is increasingly degrading because of overloading of lines. Currently, electric utilities conduct routine line inspections using thermal and electrical measurements, but these methods do not provide information about the structural integrity of connectors. In this work, structural health monitoring (SHM) of compression connectors was studied using electromechanical impedance (EMI) analysis. Lead zirconate titanate (PZT)-5A was identified as a smart material for SHM. A flexible high-temperature bonding layer was used to address challenges in PZT integration due to a significant difference in the coefficients of thermal expansion of PZT and the aluminum substrate. The steel joint on the steel core was investigated because it is responsible for the ultimate tensile strength of the connector. Tensile testing was used to induce structural damage to the joint, or steel core pullout, and thermal cycling introduced additional structural perturbations. EMI measurements were conducted between the tests. The root mean square deviation (RMSD) of EMI was identified as a damage index. The use of steel joints has been shown to enable SHM under simulated conditions. The EMI signature is sensitive to variations in structural conditions. RMSD can be correlated to the structural health of a connector and has potential for use in the SHM and structural integrity evaluation.

An ergonomics study on compatibility of controls of overhead cranes in a heavy engineering factory in West Bengal.

PubMed

Sen, R N; Das, S

2000-04-01

Ergonomics studies, on the machine control and the resultant movements of the cabins and the hooks in 51 electric overhead travelling cranes in a heavy engineering factory, showed that control-movement compatibility is absent in most of the cranes. Also, the layout of the groups of controls and the orientations of each of the individual controls with respect to the operators' seats varied from one crane to another. As the operators were shifted from one crane to another every week, there was a high chance of making mistakes during moving the controls, which might have resulted in severe accidents, especially during periods of high workload. A number of low-cost ergonomics solutions have been recommended to minimize these problems.

On-farm irrigatrion system design and operation

USDA-ARS?s Scientific Manuscript database

Most commercial blueberry fields are irrigated by overhead sprinklers or drip. Water is typically applied one to two times per week as needed with sprinklers, and every one to three days with drip. Sprinkler systems are relatively simple to install and maintain, and when designed properly, obtain re...

1. PERSPECTIVE VIEW FROM NORTHWEST OF NORTH SIDE. LOW BUILDING ...

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

1. PERSPECTIVE VIEW FROM NORTHWEST OF NORTH SIDE. LOW BUILDING IN CENTER IS A SIGNAL POWER GENERATING STATION (C. 1986). LOW TOWER STRUCTURE ON THE LEFT IS ANCHOR BRIDGE NUMBER 310, LOCATION OF POWER FEED TO THE CATENARY SYSTEM. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

MBus: An Ultra-Low Power Interconnect Bus for Next Generation Nanopower Systems.

PubMed

Pannuto, Pat; Lee, Yoonmyung; Kuo, Ye-Sheng; Foo, ZhiYoong; Kempke, Benjamin; Kim, Gyouho; Dreslinski, Ronald G; Blaauw, David; Dutta, Prabal

2015-06-01

As we show in this paper, I/O has become the limiting factor in scaling down size and power toward the goal of invisible computing. Achieving this goal will require composing optimized and specialized-yet reusable-components with an interconnect that permits tiny, ultra-low power systems. In contrast to today's interconnects which are limited by power-hungry pull-ups or high-overhead chip-select lines, our approach provides a superset of common bus features but at lower power, with fixed area and pin count, using fully synthesizable logic, and with surprisingly low protocol overhead. We present MBus , a new 4-pin, 22.6 pJ/bit/chip chip-to-chip interconnect made of two "shoot-through" rings. MBus facilitates ultra-low power system operation by implementing automatic power-gating of each chip in the system, easing the integration of active, inactive, and activating circuits on a single die. In addition, we introduce a new bus primitive: power oblivious communication, which guarantees message reception regardless of the recipient's power state when a message is sent. This disentangles power management from communication, greatly simplifying the creation of viable, modular, and heterogeneous systems that operate on the order of nanowatts. To evaluate the viability, power, performance, overhead, and scalability of our design, we build both hardware and software implementations of MBus and show its seamless operation across two FPGAs and twelve custom chips from three different semiconductor processes. A three-chip, 2.2 mm 3 MBus system draws 8 nW of total system standby power and uses only 22.6 pJ/bit/chip for communication. This is the lowest power for any system bus with MBus's feature set.

Data-Adaptable Modeling and Optimization for Runtime Adaptable Systems

DTIC Science & Technology

2016-06-08

execution scenarios e . Enables model -guided optimization algorithms that outperform state-of-the-art f. Understands the overhead of system...the Data-Adaptable System Model (DASM), that facilitates design by enabling the designer to: 1) specify both an application’s task flow as well as...systems. The MILAN [3] framework specializes in the design, simulation , and synthesis of System On Chip (SoC) applications using model -based techniques

Design of a radiator shade for testing in a simulated lunar environment

NASA Technical Reports Server (NTRS)

Huff, Jaimi; Remington, Randy; Tang, Toan

1992-01-01

The National Aeronautics and Space Administration (NASA) and The Universities Space Research Association (USRA) have chosen the parabolic/catenary concept from their sponsored Fall 1991 lunar radiation shade project for further testing and development. NASA asked the design team to build a shading device and support structure for testing in a vacuum chamber. Besides the support structure for the catenary shading device, the design team was asked to develop a system for varying the shade shape so that the device can be tested at different focal lengths. The design team developed concept variants and combined the concept variants to form overall designs. Using a decision matrix, an overall design was selected by the team from several overall design alternatives. Concept variants were developed for three primary functions. The three functions were structural support, shape adjustments, and end shielding. The shade adjustment function was divided into two sub-functions, arc length adjustment, and width adjustment.

Environmental factors affecting feed intake of steers in different housing systems in the summer

NASA Astrophysics Data System (ADS)

Koknaroglu, H.; Otles, Z.; Mader, T.; Hoffman, M. P.

2008-07-01

A total of 188 yearling steers of predominantly Angus and Hereford breeds, with mean body weight of 299 kg, were used in this study, which started on 8 April and finished on 3 October, to assess the effects of environmental factors on feed intake of steers in various housing systems. Housing consisted of outside lots with access to overhead shelter, outside lots with no overhead shelter and a cold confinement building. Ad libitum corn, 2.27 kg of 35% dry matter whole plant sorghum silage and 0.68 kg of a 61% protein-vitamin-mineral supplement was offered. Feed that was not consumed was measured to determine feed intake. The temperature data were recorded by hygro-thermographs. Hourly temperatures and humidity were used to develop weather variables. Regression analysis was used and weather variables were regressed on dry matter intake (DMI). When addition of a new variable did not improve R 2 more than one unit, then the number of variables in the model was truncated. Cattle in confinement had lower DMI than those in open lots and those in open lots with access to an overhead shelter ( P < 0.05). Cattle in outside lots with access to overhead shelter had similar DMI compared to those in open lots ( P = 0.065). Effect of heat was predominantly displayed in August in the three housing systems. In terms of explaining variation in DMI, in outside lots with access to overhead shelter, average and daytime temperatures were important factors, whereas in open lots, nocturnal, peak and average temperatures were important factors. In confinement buildings, the previous day’s temperature and humidity index were the most important factors explaining variation in DMI. Results show the effect of housing and weather variables on DMI in summer and when considering these results, cattle producers wishing to improve cattle feedlot performance should consider housing conditions providing less stress or more comfort.

Simulation study on electric field intensity above train roof

NASA Astrophysics Data System (ADS)

Fan, Yizhe; Li, Huawei; Yang, Shasha

2018-04-01

In order to understand the distribution of electric field in the space above the train roof accurately and select the installation position of the detection device reasonably, in this paper, the 3D model of pantograph-catenary is established by using SolidWorks software, and the spatial electric field distribution of pantograph-catenary model is simulated based on Comsol software. According to the electric field intensity analysis within the 0.4m space above train roof, we give a reasonable installation of the detection device.

Design and Experiment of FBG-Based Icing Monitoring on Overhead Transmission Lines with an Improvement Trial for Windy Weather

PubMed Central

Zhang, Min; Xing, Yimeng; Zhang, Zhiguo; Chen, Qiguan

2014-01-01

A scheme for monitoring icing on overhead transmission lines with fiber Bragg grating (FBG) strain sensors is designed and evaluated both theoretically and experimentally. The influences of temperature and wind are considered. The results of field experiments using simulated ice loading on windless days indicate that the scheme is capable of monitoring the icing thickness within 0–30 mm with an accuracy of ±1 mm, a load cell error of 0.0308v, a repeatability error of 0.3328v and a hysteresis error is 0.026%. To improve the measurement during windy weather, a correction factor is added to the effective gravity acceleration, and the absolute FBG strain is replaced by its statistical average. PMID:25615733

Design and experiment of FBG-based icing monitoring on overhead transmission lines with an improvement trial for windy weather.

PubMed

Zhang, Min; Xing, Yimeng; Zhang, Zhiguo; Chen, Qiguan

2014-12-12

A scheme for monitoring icing on overhead transmission lines with fiber Bragg grating (FBG) strain sensors is designed and evaluated both theoretically and experimentally. The influences of temperature and wind are considered. The results of field experiments using simulated ice loading on windless days indicate that the scheme is capable of monitoring the icing thickness within 0-30 mm with an accuracy of ±1 mm, a load cell error of 0.0308v, a repeatability error of 0.3328v and a hysteresis error is 0.026%. To improve the measurement during windy weather, a correction factor is added to the effective gravity acceleration, and the absolute FBG strain is replaced by its statistical average.

Fault-Tolerant Multiprocessor and VLSI-Based Systems.

DTIC Science & Technology

1987-03-15

54590 170 Table 1: Statistics for the Benchmark Programs pages are distributed amongst the groups of the reconfigured memory in proportion to the...distances are proportional to only the logarithm of the sure that possesses relevance to a system which consists of alare nmbe ofhomgenouseleent...and comn.unication overhead resulting from faults communicating with all of the other elements in the system the network to degrade proportionately to

Loading differences in single-leg landing in the forehand- and backhand-side courts after an overhead stroke in badminton: A novel tri-axial accelerometer research.

PubMed

Sasaki, Shogo; Nagano, Yasuharu; Ichikawa, Hiroshi

2018-05-10

Anterior cruciate ligament (ACL) injuries in badminton commonly occur during single-leg landing after an overhead stroke in the backhand-side court. This study compared differences in trunk acceleration and kinematic variables during single-leg landing in the forehand- and backhand-side courts after an overhead stroke. Eighteen female junior badminton players performed two singles games while wearing a tri-axial accelerometer. The moment that over 4g of resultant acceleration was generated was determined using synchronised video cameras. Trunk lateral inclination and hip abduction angles at the point of landing with over 4g of resultant acceleration were analysed. Mediolateral acceleration in the backhand-side court was greater than that in the opposite-side court (p < 0.001, ES = 0.840). Both trunk lateral angles were larger than those previously reported in injured participants and the hip abduction angle in the backhand-side court was larger than that in the forehand-side court (p < 0.001, ES = 2.357). The lateral and vertical acceleration in the backhand-side court showed moderate-to-strong correlations with the trunk and hip angles. The mediolateral physical demand and high-risk posture in the backhand-side court may be associated with a higher incidence of knee injuries during badminton games.

MBus: An Ultra-Low Power Interconnect Bus for Next Generation Nanopower Systems

PubMed Central

Pannuto, Pat; Lee, Yoonmyung; Kuo, Ye-Sheng; Foo, ZhiYoong; Kempke, Benjamin; Kim, Gyouho; Dreslinski, Ronald G.; Blaauw, David; Dutta, Prabal

2015-01-01

As we show in this paper, I/O has become the limiting factor in scaling down size and power toward the goal of invisible computing. Achieving this goal will require composing optimized and specialized—yet reusable—components with an interconnect that permits tiny, ultra-low power systems. In contrast to today’s interconnects which are limited by power-hungry pull-ups or high-overhead chip-select lines, our approach provides a superset of common bus features but at lower power, with fixed area and pin count, using fully synthesizable logic, and with surprisingly low protocol overhead. We present MBus, a new 4-pin, 22.6 pJ/bit/chip chip-to-chip interconnect made of two “shoot-through” rings. MBus facilitates ultra-low power system operation by implementing automatic power-gating of each chip in the system, easing the integration of active, inactive, and activating circuits on a single die. In addition, we introduce a new bus primitive: power oblivious communication, which guarantees message reception regardless of the recipient’s power state when a message is sent. This disentangles power management from communication, greatly simplifying the creation of viable, modular, and heterogeneous systems that operate on the order of nanowatts. To evaluate the viability, power, performance, overhead, and scalability of our design, we build both hardware and software implementations of MBus and show its seamless operation across two FPGAs and twelve custom chips from three different semiconductor processes. A three-chip, 2.2 mm3 MBus system draws 8 nW of total system standby power and uses only 22.6 pJ/bit/chip for communication. This is the lowest power for any system bus with MBus’s feature set. PMID:26855555

Scalable PGAS Metadata Management on Extreme Scale Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chavarría-Miranda, Daniel; Agarwal, Khushbu; Straatsma, TP

Programming models intended to run on exascale systems have a number of challenges to overcome, specially the sheer size of the system as measured by the number of concurrent software entities created and managed by the underlying runtime. It is clear from the size of these systems that any state maintained by the programming model has to be strictly sub-linear in size, in order not to overwhelm memory usage with pure overhead. A principal feature of Partitioned Global Address Space (PGAS) models is providing easy access to global-view distributed data structures. In order to provide efficient access to these distributedmore » data structures, PGAS models must keep track of metadata such as where array sections are located with respect to processes/threads running on the HPC system. As PGAS models and applications become ubiquitous on very large transpetascale systems, a key component to their performance and scalability will be efficient and judicious use of memory for model overhead (metadata) compared to application data. We present an evaluation of several strategies to manage PGAS metadata that exhibit different space/time tradeoffs. We use two real-world PGAS applications to capture metadata usage patterns and gain insight into their communication behavior.« less

Exploring a QoS Driven Scheduling Approach for Peer-to-Peer Live Streaming Systems with Network Coding

PubMed Central

Cui, Laizhong; Lu, Nan; Chen, Fu

2014-01-01

Most large-scale peer-to-peer (P2P) live streaming systems use mesh to organize peers and leverage pull scheduling to transmit packets for providing robustness in dynamic environment. The pull scheduling brings large packet delay. Network coding makes the push scheduling feasible in mesh P2P live streaming and improves the efficiency. However, it may also introduce some extra delays and coding computational overhead. To improve the packet delay, streaming quality, and coding overhead, in this paper are as follows. we propose a QoS driven push scheduling approach. The main contributions of this paper are: (i) We introduce a new network coding method to increase the content diversity and reduce the complexity of scheduling; (ii) we formulate the push scheduling as an optimization problem and transform it to a min-cost flow problem for solving it in polynomial time; (iii) we propose a push scheduling algorithm to reduce the coding overhead and do extensive experiments to validate the effectiveness of our approach. Compared with previous approaches, the simulation results demonstrate that packet delay, continuity index, and coding ratio of our system can be significantly improved, especially in dynamic environments. PMID:25114968

Comparison of the backward overhead medicine ball throw to power production in college football players.

PubMed

Mayhew, Jerry L; Bird, Michael; Cole, Mary L; Koch, Alex J; Jacques, Jeff A; Ware, John S; Buford, Brittney N; Fletcher, Kate M

2005-08-01

The purpose of this study was to determine the relationship of the backward overhead medicine ball (BOMB) throw to power production in college football players. Forty National Collegiate Athletic Association Division II college football players were studied at the end of an 8-week off-season conditioning program for power output determined from a countermovement vertical jump on a force plate and for maximal distance in the standing BOMB throw. Although the reliability of the BOMB test was high (interclass correlation coefficient = 0.86), there was a significant learning effect across 3 trials (p < 0.01). Peak and average powers generated during the vertical jump correlated moderately but significantly with the best BOMB throw distance (r = 0.59 and 0.63, respectively). Considering power relative to body mass or lean body mass failed to produce significant correlations with BOMB throw distance (r = 0.27 and 0.28, respectively). Therefore, the BOMB throw may have limited potential as a predictor of total body explosive power in college football players.

A physiology-based parametric imaging method for FDG-PET data

NASA Astrophysics Data System (ADS)

Scussolini, Mara; Garbarino, Sara; Sambuceti, Gianmario; Caviglia, Giacomo; Piana, Michele

2017-12-01

Parametric imaging is a compartmental approach that processes nuclear imaging data to estimate the spatial distribution of the kinetic parameters governing tracer flow. The present paper proposes a novel and efficient computational method for parametric imaging which is potentially applicable to several compartmental models of diverse complexity and which is effective in the determination of the parametric maps of all kinetic coefficients. We consider applications to [18 F]-fluorodeoxyglucose positron emission tomography (FDG-PET) data and analyze the two-compartment catenary model describing the standard FDG metabolization by an homogeneous tissue and the three-compartment non-catenary model representing the renal physiology. We show uniqueness theorems for both models. The proposed imaging method starts from the reconstructed FDG-PET images of tracer concentration and preliminarily applies image processing algorithms for noise reduction and image segmentation. The optimization procedure solves pixel-wise the non-linear inverse problem of determining the kinetic parameters from dynamic concentration data through a regularized Gauss-Newton iterative algorithm. The reliability of the method is validated against synthetic data, for the two-compartment system, and experimental real data of murine models, for the renal three-compartment system.

Remote sensing for industrial applications in the energy business: digital territorial data integration for planning of overhead power transmission lines (OHTLs)

NASA Astrophysics Data System (ADS)

Terrazzino, Alfonso; Volponi, Silvia; Borgogno Mondino, Enrico

2001-12-01

An investigation has been carried out, concerning remote sensing techniques, in order to assess their potential application to the energy system business: the most interesting results concern a new approach, based on digital data from remote sensing, to infrastructures with a large territorial distribution: in particular OverHead Transmission Lines, for the high voltage transmission and distribution of electricity on large distances. Remote sensing could in principle be applied to all the phases of the system lifetime, from planning to design, to construction, management, monitoring and maintenance. In this article, a remote sensing based approach is presented, targeted to the line planning: optimization of OHTLs path and layout, according to different parameters (technical, environmental and industrial). Planning new OHTLs is of particular interest in emerging markets, where typically the cartography is missing or available only on low accuracy scale (1:50.000 and lower), often not updated. Multi- spectral images can be used to generate thematic maps of the region of interest for the planning (soil coverage). Digital Elevation Models (DEMs), allow the planners to easily access the morphologic information of the surface. Other auxiliary information from local laws, environmental instances, international (IEC) standards can be integrated in order to perform an accurate optimized path choice and preliminary spotting of the OHTLs. This operation is carried out by an ABB proprietary optimization algorithm: the output is a preliminary path that bests fits the optimization parameters of the line in a life cycle approach.

Providing scalable system software for high-end simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenberg, D.

1997-12-31

Detailed, full-system, complex physics simulations have been shown to be feasible on systems containing thousands of processors. In order to manage these computer systems it has been necessary to create scalable system services. In this talk Sandia`s research on scalable systems will be described. The key concepts of low overhead data movement through portals and of flexible services through multi-partition architectures will be illustrated in detail. The talk will conclude with a discussion of how these techniques can be applied outside of the standard monolithic MPP system.

KENNEDY SPACE CENTER, FLA. - At the Astrotech Space Operations processing facilities, an overhead crane moves NASA’s MESSENGER spacecraft toward a work stand. There employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - At the Astrotech Space Operations processing facilities, an overhead crane moves NASA’s MESSENGER spacecraft toward a work stand. There employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

KENNEDY SPACE CENTER, FLA. - At the Astrotech Space Operations processing facilities, an overhead crane lowers NASA’s MESSENGER spacecraft onto a work stand. There employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - At the Astrotech Space Operations processing facilities, an overhead crane lowers NASA’s MESSENGER spacecraft onto a work stand. There employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

Expert system application for the loading capability assessment of transmission lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Le, T.L.; Negnevitsky, M.; Piekutowski, M.

1995-11-01

This paper describes the application of an expert system for the evaluation of the short time thermal rating and temperature rise of overhead conductors. The expert system has been developed using a database and Leonardo expert system shell which is gaining popularity among commercial tools for developing expert system applications. The expert system has been found to compare well when evaluated against the site tests. A practical application is given to demonstrate the usefulness of the expert system developed.

Academic Health Systems Management: The Rationale Behind Capitated Contracts

PubMed Central

Taheri, Paul A.; Butz, David A.; Greenfield, Lazar J.

2000-01-01

Objective To determine why hospitals enter into “capitated” contracts, which often generate accounting losses. The authors’ hypothesis is that hospitals coordinate contracts to keep beds full and that in principal, capitated contracts reflect sound capacity management. Summary Background Data In high-overhead industries, different consumers pay different prices for similar services (e.g., full-fare vs. advanced-purchase plane tickets, full tuition vs. financial aid). Some consumers gain access by paying less than total cost. Hospitals, like other high-overhead business enterprises, must optimize the use of their capacity, amortizing overhead over as many patients as possible. This necessity for enhanced throughput forces hospitals and health systems to discount empty beds, sometimes to the point where they incur accounting losses serving some payors. Methods The authors analyzed the cost accounting system at their university teaching hospital to compare hospital and intensive care unit (ICU) lengths of stay (LOS), variable direct costs (VDC), overhead of capitated patients, and reimbursement versus other payors for all hospital discharges (n = 29,036) in fiscal year 1998. The data were analyzed by diagnosis-related groups (DRGs), length of stay (LOS), insurance carrier, proximity to hospital, and discharge disposition. Patients were then distinguished across payor categories based on their resource utilization, proximity to the hospital, DRG, LOS, and discharge status. Results The mean cost for capitated patients was $4,887, less than half of the mean cost of $10,394 for the entire hospitalized population. The mean capitated reimbursement was $928/day, exceeding the mean daily VDC of $616 but not the total cost of $1,445/day. Moreover, the mean total cost per patient day of treating a capitated patient was $400 less than the mean total cost per day for noncapitated patients. The hospital’s capitated health maintenance organization (HMO) patients made up 16

Academic health systems management: the rationale behind capitated contracts.

PubMed

Taheri, P A; Butz, D A; Greenfield, L J

2000-06-01

To determine why hospitals enter into "capitated" contracts, which often generate accounting losses. The authors' hypothesis is that hospitals coordinate contracts to keep beds full and that in principal, capitated contracts reflect sound capacity management. In high-overhead industries, different consumers pay different prices for similar services (e.g., full-fare vs. advanced-purchase plane tickets, full tuition vs. financial aid). Some consumers gain access by paying less than total cost. Hospitals, like other high-overhead business enterprises, must optimize the use of their capacity, amortizing overhead over as many patients as possible. This necessity for enhanced throughput forces hospitals and health systems to discount empty beds, sometimes to the point where they incur accounting losses serving some payors. The authors analyzed the cost accounting system at their university teaching hospital to compare hospital and intensive care unit (ICU) lengths of stay (LOS), variable direct costs (VDC), overhead of capitated patients, and reimbursement versus other payors for all hospital discharges (n = 29,036) in fiscal year 1998. The data were analyzed by diagnosis-related groups (DRGs), length of stay (LOS), insurance carrier, proximity to hospital, and discharge disposition. Patients were then distinguished across payor categories based on their resource utilization, proximity to the hospital, DRG, LOS, and discharge status. The mean cost for capitated patients was $4,887, less than half of the mean cost of $10,394 for the entire hospitalized population. The mean capitated reimbursement was $928/day, exceeding the mean daily VDC of $616 but not the total cost of $1,445/day. Moreover, the mean total cost per patient day of treating a capitated patient was $400 less than the mean total cost per day for noncapitated patients. The hospital's capitated health maintenance organization (HMO) patients made up 16. 0% of the total admissions but only 9.4% of the total

Finding science is fun in a 'Magic Show of Light' from Optical Demonstrations on an Overhead Projector for elementary school students

NASA Astrophysics Data System (ADS)

Lones, Joe J.; Maltseva, Nadezhda K.; Peterson, Kurt N.

2007-09-01

We seek methods of stimulating young school children to develop an interest in science and engineering through a natural curiosity for the reaction of light. Science learning now begins fully at middle school. Reading skills develop with activity at home and progress through the elementary school curriculum, and in a like manner, a curious interest in science also should begin at that stage of life. Within the ranks of educators, knowledge of optical science needs to be presented to elementary school students in an entertaining manner. One such program used by the authors is Doug Goodman's Optics Demonstrations With the Overhead Projector, co-published by and available from OSA (Optical Society of America) and SPIE-The International Society of Optical Engineering. These demonstrations have been presented in middle and high schools; however, as a special approach, the authors have developed selected Goodman demonstrations as a "Magic Show of Light" for elementary schools. Teachers in the U.S. are overloaded with classroom instruction specifically targeted at improving reading and math scores on the Standard Achievement Test (SAT); therefore, science is getting "short changed" in the education system. For the sake of our future, industry volunteers must come forward to promote interest in science beginning with K-6.

Aircraft Hangar Fire Suppression System Evaluation-Intermediate- Scale Studies

DTIC Science & Technology

1999-12-23

aqueous film forming foam ( AFFF ) extinguishing systems [1]. The overhead AFFF system typically consists of standard closed head sprinklers that...of Water Spray on Fire-Fighting Foam ," Fire Journal, 63 (6), November 1969. 5. MIL-F-24385F, "Fire Extinguishing Agent, Aqueous Film Forming Foam ...extinguishing capability of the foam and the ability of the blanket to resist burnback. When AFFF is applied over a flammable liquid spill

Design Considerations for Abrasive Blast Rooms and Recovery Systems

DTIC Science & Technology

2010-02-01

COLUMN BOLT – ALLOWS FOR WIDER ENCLOSURES – STRONG ENOUGH TO SUPPORT MONORAIL Flange Bolt Room Column Bolt Room • Structural steel framework...OVERHEAD MONORAILS • EXTERIOR WORK STATIONS • TURNTABLES • HORIZONTAL ROTATION DEVICES OVERHEAD MONORAIL Workpiece Handling • Powered horizontal rotation

20. SIMILAR TO THE SYSTEM INSTALLED IN THE GREY IRON ...

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

20. SIMILAR TO THE SYSTEM INSTALLED IN THE GREY IRON FOUNDRY, MALLEABLE WORKERS FILLED MOLDS TRAVELING ON A CONVEYOR FROM LADLES ATTACHED TO OVERHEAD RAILS WHILE THEY STOOD ON A PLATFORM MOVING AT THE SAME SPEED AS THE CONVEYOR, CA. 1950 - Stockham Pipe & Fittings Company, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

Nested Interrupt Analysis of Low Cost and High Performance Embedded Systems Using GSPN Framework

NASA Astrophysics Data System (ADS)

Lin, Cheng-Min

Interrupt service routines are a key technology for embedded systems. In this paper, we introduce the standard approach for using Generalized Stochastic Petri Nets (GSPNs) as a high-level model for generating CTMC Continuous-Time Markov Chains (CTMCs) and then use Markov Reward Models (MRMs) to compute the performance for embedded systems. This framework is employed to analyze two embedded controllers with low cost and high performance, ARM7 and Cortex-M3. Cortex-M3 is designed with a tail-chaining mechanism to improve the performance of ARM7 when a nested interrupt occurs on an embedded controller. The Platform Independent Petri net Editor 2 (PIPE2) tool is used to model and evaluate the controllers in terms of power consumption and interrupt overhead performance. Using numerical results, in spite of the power consumption or interrupt overhead, Cortex-M3 performs better than ARM7.

A cost-benefit analysis of peer coaching for overhead lift use in the long-term care sector in Canada.

PubMed

Tompa, Emile; Dolinschi, Roman; Alamgir, Hasanat; Sarnocinska-Hart, Anna; Guzman, Jaime

2016-05-01

To evaluate whether a peer-coaching programme for patient lift use in British Columbia, Canada, was effective and cost-beneficial. We used monthly panel data from 15 long-term care facilities from 2004 to 2011 to estimate the number of patient-handling injuries averted by the peer-coaching programme using a generalised estimating equation model. Facilities that had not yet introduced the programme served as concurrent controls. Accepted lost-time claim counts related to patient handling were the outcome of interest with a denominator of full-time equivalents of nursing staff. A cost-benefit approach was used to estimate the net monetary gains at the system level. The coaching programme was found to be associated with a reduction in the injury rate of 34% during the programme and 56% after the programme concluded with an estimated 62 lost-time injury claims averted. 2 other factors were associated with changes in injury rates: larger facilities had a lower injury rate, and the more care hours per bed the lower the injury rate. We calculated monetary benefits to the system of $748 431 and costs of $894 000 (both in 2006 Canadian dollars) with a benefit-to-cost ratio of 0.84. The benefit-to-cost ratio was -0.05 in the worst case scenario and 2.31 in the best case scenario. The largest cost item was peer coaches' time. A simulation of the programme continuing for 5 years with the same coaching intensity would result in a benefit-to-cost ratio of 0.63. A peer-coaching programme to increase effective use of overhead lifts prevented additional patient-handling injuries but added modest incremental cost to the system. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Scapular Contribution for the End-Range of Shoulder Axial Rotation in Overhead Athletes

PubMed Central

Ribeiro, Andrea; Pascoal, Augusto Gil

2012-01-01

The aim of this study was to analyze the relative contribution of the scapular motion on the extreme range-of-motion of shoulder external and internal rotation, in overhead athletes. An electromagnetic tracking device (Flock of Birds) was used to record humeral and scapular kinematics. The dominant arm of 26 male subjects (13 athletes and 13 non-athletes) was studied while subjects actively reached end-range of internal and external rotation. Humeral and scapular angles were calculated and compared across groups by means of a t-test for independent samples. A bivariate correlation approach was used to describe the relationship between humeral angles and scapular variables. The range-of-motion of the thoracohumeral angles, during shoulder external rotation was significantly less (p < 0.05) on the athletes group, athletes also positioned their dominant scapula more retracted and posteriorly tilted. A positive correlation was found between glenohumeral angles and scapular tilt (r = 0.6777; p < 0.05). Concerning internal rotation; athletes showed significantly greater (highest) thoracohumeral angles (p < 0.05). Scapula assumed a position more in retraction and anterior tilt. Based on these findings, it is suggested that differences found in athletes seem to reveal an eventual shoulder adaptation to the throwing mechanics. Key points In external rotation end-range, athletes positioned their scapula more in retraction and posterior tilt. In internal rotation end-range, athletes positioned their scapula more in retraction and anterior tilt. Results seem to reveal a sport-related shoulder adaptation. PMID:24150078

System design of a large fuel cell hybrid locomotive

NASA Astrophysics Data System (ADS)

Miller, A. R.; Hess, K. S.; Barnes, D. L.; Erickson, T. L.

Fuel cell power for locomotives combines the environmental benefits of a catenary-electric locomotive with the higher overall energy efficiency and lower infrastructure costs of a diesel-electric. A North American consortium, a public-private partnership, is developing a prototype hydrogen-fueled fuel cell-battery hybrid switcher locomotive for urban and military-base rail applications. Switcher locomotives are used in rail yards for assembling and disassembling trains and moving trains from one point to another. At 127 tonnes (280,000 lb), continuous power of 250 kW from its (proton exchange membrane) PEM fuel cell prime mover, and transient power well in excess of 1 MW, the hybrid locomotive will be the heaviest and most powerful fuel cell land vehicle yet. This fast-paced project calls for completion of the vehicle itself near the end of 2007. Several technical challenges not found in the development of smaller vehicles arise when designing and developing such a large fuel cell vehicle. Weight, center of gravity, packaging, and safety were design factors leading to, among other features, the roof location of the lightweight 350 bar compressed hydrogen storage system. Harsh operating conditions, especially shock loads during coupling to railcars, require component mounting systems capable of absorbing high energy. Vehicle scale-up by increasing mass, density, or power presents new challenges primarily related to issues of system layout, hydrogen storage, heat transfer, and shock loads.

Control Transfer in Operating System Kernels

DTIC Science & Technology

1994-05-13

microkernel system that runs less code in the kernel address space. To realize the performance benefit of allocating stacks in unmapped kseg0 memory, the...review how I modified the Mach 3.0 kernel to use continuations. Because of Mach’s message-passing microkernel structure, interprocess communication was...critical control transfer paths, deeply- nested call chains are undesirable in any case because of the function call overhead. 4.1.3 Microkernel Operating

Experimental demonstration of an OFDM based visible light communication system using inter-block precoding and superimposed pilots

NASA Astrophysics Data System (ADS)

Zhang, Junwei; Hong, Xuezhi; Liu, Jie; Guo, Changjian

2018-04-01

In this work, we investigate and experimentally demonstrate an orthogonal frequency division multiplexing (OFDM) based high speed wavelength-division multiplexed (WDM) visible light communication (VLC) system using an inter-block data precoding and superimposed pilots (DP-SP) based channel estimation (CE) scheme. The residual signal-to-pilot interference (SPI) can be eliminated by using inter-block data precoding, resulting in a significant improvement in estimated accuracy and the overall system performance compared with uncoded SP based CE scheme. We also study the power allocation/overhead problem of the training for DP-SP, uncoded SP and conventional preamble based CE schemes, from which we obtain the optimum signal-to-pilot power ratio (SPR)/overhead percentage for all above cases. Intra-symbol frequency-domain averaging (ISFA) is also adopted to further enhance the accuracy of CE. By using the DP-SP based CE scheme, aggregate data rates of 1.87-Gbit/s and 1.57-Gbit/s are experimentally demonstrated over 0.8-m and 2-m indoor free space transmission, respectively, using a commercially available red, green and blue (RGB) light emitting diode (LED) with WDM. Experimental results show that the DP-SP based CE scheme is comparable to the conventional preamble based CE scheme in term of received Q factor and data rate while entailing a much smaller overhead-size.

The optimum spanning catenary cable

NASA Astrophysics Data System (ADS)

Wang, C. Y.

2015-03-01

A heavy cable spans two points in space. There exists an optimum cable length such that the maximum tension is minimized. If the two end points are at the same level, the optimum length is 1.258 times the distance between the ends. The optimum lengths for end points of different heights are also found.

Data base systems in electronic design engineering

NASA Technical Reports Server (NTRS)

Williams, D.

1980-01-01

The concepts of an integrated design data base system (DBMS) as it might apply to an electronic design company are discussed. Data elements of documentation, project specifications, project tracking, firmware, software, electronic and mechanical design can be integrated and managed through a single DBMS. Combining the attributes of a DBMS data handler with specialized systems and functional data can provide users with maximum flexibility, reduced redundancy, and increased overall systems performance. Although some system overhead is lost due to redundancy in transitory data, it is believed the combination of the two data types is advisable rather than trying to do all data handling through a single DBMS.

Expert systems tools for Hubble Space Telescope observation scheduling

NASA Technical Reports Server (NTRS)

Miller, Glenn; Rosenthal, Don; Cohen, William; Johnston, Mark

1987-01-01

The utility of expert systems techniques for the Hubble Space Telescope (HST) planning and scheduling is discussed and a plan for development of expert system tools which will augment the existing ground system is described. Additional capabilities provided by these tools will include graphics-oriented plan evaluation, long-range analysis of the observation pool, analysis of optimal scheduling time intervals, constructing sequences of spacecraft activities which minimize operational overhead, and optimization of linkages between observations. Initial prototyping of a scheduler used the Automated Reasoning Tool running on a LISP workstation.

47 CFR 76.1504 - Rates, terms and conditions for carriage on open video systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

....1504 Rates, terms and conditions for carriage on open video systems. (a) Reasonable rate principle. An... operator will bear the burden of proof to demonstrate, using the principles set forth below, that the...; (2) Packaging, including marketing and other fees; (3) Talent fees; and (4) A reasonable overhead...

System for Performing Single Query Searches of Heterogeneous and Dispersed Databases

NASA Technical Reports Server (NTRS)

Maluf, David A. (Inventor); Okimura, Takeshi (Inventor); Gurram, Mohana M. (Inventor); Tran, Vu Hoang (Inventor); Knight, Christopher D. (Inventor); Trinh, Anh Ngoc (Inventor)

2017-01-01

The present invention is a distributed computer system of heterogeneous databases joined in an information grid and configured with an Application Programming Interface hardware which includes a search engine component for performing user-structured queries on multiple heterogeneous databases in real time. This invention reduces overhead associated with the impedance mismatch that commonly occurs in heterogeneous database queries.

A diagnostic interface for the ICOsahedral Non-hydrostatic (ICON) modelling framework based on the Modular Earth Submodel System (MESSy v2.50)

NASA Astrophysics Data System (ADS)

Kern, Bastian; Jöckel, Patrick

2016-10-01

Numerical climate and weather models have advanced to finer scales, accompanied by large amounts of output data. The model systems hit the input and output (I/O) bottleneck of modern high-performance computing (HPC) systems. We aim to apply diagnostic methods online during the model simulation instead of applying them as a post-processing step to written output data, to reduce the amount of I/O. To include diagnostic tools into the model system, we implemented a standardised, easy-to-use interface based on the Modular Earth Submodel System (MESSy) into the ICOsahedral Non-hydrostatic (ICON) modelling framework. The integration of the diagnostic interface into the model system is briefly described. Furthermore, we present a prototype implementation of an advanced online diagnostic tool for the aggregation of model data onto a user-defined regular coarse grid. This diagnostic tool will be used to reduce the amount of model output in future simulations. Performance tests of the interface and of two different diagnostic tools show, that the interface itself introduces no overhead in form of additional runtime to the model system. The diagnostic tools, however, have significant impact on the model system's runtime. This overhead strongly depends on the characteristics and implementation of the diagnostic tool. A diagnostic tool with high inter-process communication introduces large overhead, whereas the additional runtime of a diagnostic tool without inter-process communication is low. We briefly describe our efforts to reduce the additional runtime from the diagnostic tools, and present a brief analysis of memory consumption. Future work will focus on optimisation of the memory footprint and the I/O operations of the diagnostic interface.

The Reusable Load Cell with Protection Applied for Online Monitoring of Overhead Transmission Lines Based on Fiber Bragg Grating

PubMed Central

Ma, Guoming; Mao, Naiqiang; Li, Yabo; Jiang, Jun; Zhou, Hongyang; Li, Chengrong

2016-01-01

Heavy ice coating of high–voltage overhead transmission lines may lead to conductor breakage and tower collapse causing the unexpected interrupt of power supply. The optical load cell applied in ice monitoring systems is immune to electromagnetic interference and has no need of a power supply on site. Therefore, it has become a hot research topic in China and other countries. In this paper, to solve the problem of eccentric load in measurement, we adopt the shearing structure with additional grooves to improve the strain distribution and acquire good repeatability. Then, the fiber Bragg grating (FBG) with a permanent weldable package are mounted onto the front/rear groove of the elastic element by spot welding, the direction deviation of FBGs is 90° from each other to achieve temperature compensation without an extra FBG. After that, protection parts are designed to guarantee high sensitivity for a light load condition and industrial safety under a heavy load up to 65 kN. The results of tension experiments indicate that the sensitivity and resolution of the load cell is 0.1285 pm/N and 7.782 N in the conventional measuring range (0–10 kN). Heavy load tension experiments prove that the protection structure works and the sensitivity and resolution are not changed after several high load (65 kN) cycles. In addition, the experiment shows that the resolution of the sensor is 87.79 N in the large load range, allowing the parameter to be used in heavy icing monitoring. PMID:27338403

Type of Material in the Pipes Overhead Power Lines Impact on the Distribution on the Size of the Overhang and the Tension

NASA Astrophysics Data System (ADS)

Pawlak, Urszula; Pawlak, Marcin

2017-10-01

The article presents the material type from which the conductors of the overhead power lines are produced influences on the size of the overhang and the tension. The aim of the calculations was to present the benefits of the mechanics of the cable resulting from the type of cable used. The analysis was performed for two types of cables: aluminium with steel core and aluminium with composite core, twice span power line section. 10 different conductor-to-strand coil, wind, icing, and temperature variations were included in the calculations. The string description was made by means of a chain curve, while the horizontal component H of the tension force was determined using the bisection method. The loads were collected in accordance with applicable Eurocode.

KSC-08pd4106

NASA Image and Video Library

2008-12-19

CAPE CANAVERAL, Fla. -- On Launch Pad 39B at NASA's Kennedy Space Center in Florida, one of the new lightning towers is under construction. The towers will hold catenary wires as part of the new lightning protection system for the Constellation Program and Ares/Orion launches. Pad 39B will be the site of the first Ares vehicle launch, including Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Tim Jacobs

NASA MSFC hardware in the loop simulations of automatic rendezvous and capture systems

NASA Technical Reports Server (NTRS)

Tobbe, Patrick A.; Naumann, Charles B.; Sutton, William; Bryan, Thomas C.

1991-01-01

Two complementary hardware-in-the-loop simulation facilities for automatic rendezvous and capture systems at MSFC are described. One, the Flight Robotics Laboratory, uses an 8 DOF overhead manipulator with a work volume of 160 by 40 by 23 feet to evaluate automatic rendezvous algorithms and range/rate sensing systems. The other, the Space Station/Station Operations Mechanism Test Bed, uses a 6 DOF hydraulic table to perform docking and berthing dynamics simulations.

Bidirectional DC-DC conversion device use at system of urban electric transport

NASA Astrophysics Data System (ADS)

Vilberger, M. E.; Vislogusov, D. P.; Kotin, D. A.; Kulekina, A. V.

2017-10-01

The paper considers questions of energy storage devices used in electric transport, especially in the electric traction drive of a trolley bus, in order to provide an autonomous motion, overhead system’s load leveling and energy recovering. For efficiency of the proposed system, a bidirectional DC-DC converter is used. During the simulation, regulation characteristics of the bidirectional DC-DC converters were obtained.

Multiprogramming performance degradation - Case study on a shared memory multiprocessor

NASA Technical Reports Server (NTRS)

Dimpsey, R. T.; Iyer, R. K.

1989-01-01

The performance degradation due to multiprogramming overhead is quantified for a parallel-processing machine. Measurements of real workloads were taken, and it was found that there is a moderate correlation between the completion time of a program and the amount of system overhead measured during program execution. Experiments in controlled environments were then conducted to calculate a lower bound on the performance degradation of parallel jobs caused by multiprogramming overhead. The results show that the multiprogramming overhead of parallel jobs consumes at least 4 percent of the processor time. When two or more serial jobs are introduced into the system, this amount increases to 5.3 percent

A privacy protection for an mHealth messaging system

NASA Astrophysics Data System (ADS)

Aaleswara, Lakshmipathi; Akopian, David; Chronopoulos, Anthony T.

2015-03-01

In this paper, we propose a new software system that employs features that help the organization to comply with USA HIPAA regulations. The system uses SMS as the primary way of communication to transfer information. Lack of knowledge about some diseases is still a major reason for some harmful diseases spreading. The developed system includes different features that may help to communicate amongst low income people who don't even have access to the internet. Since the software system deals with Personal Health Information (PHI) it is equipped with an access control authentication system mechanism to protect privacy. The system is analyzed for performance to identify how much overhead the privacy rules impose.

Principles and techniques in the design of ADMS+. [advanced data-base management system

NASA Technical Reports Server (NTRS)

Roussopoulos, Nick; Kang, Hyunchul

1986-01-01

'ADMS+/-' is an advanced data base management system whose architecture integrates the ADSM+ mainframe data base system with a large number of work station data base systems, designated ADMS-; no communications exist between these work stations. The use of this system radically decreases the response time of locally processed queries, since the work station runs in a single-user mode, and no dynamic security checking is required for the downloaded portion of the data base. The deferred update strategy used reduces overhead due to update synchronization in message traffic.

Knowledge-intensive software design systems: Can too much knowledge be a burden?

NASA Technical Reports Server (NTRS)

Keller, Richard M.

1992-01-01

While acknowledging the considerable benefits of domain-specific, knowledge-intensive approaches to automated software engineering, it is prudent to carefully examine the costs of such approaches, as well. In adding domain knowledge to a system, a developer makes a commitment to understanding, representing, maintaining, and communicating that knowledge. This substantial overhead is not generally associated with domain-independent approaches. In this paper, I examine the downside of incorporating additional knowledge, and illustrate with examples based on our experience in building the SIGMA system. I also offer some guidelines for developers building domain-specific systems.

Knowledge-intensive software design systems: Can too much knowledge be a burden?

NASA Technical Reports Server (NTRS)

Keller, Richard M.

1992-01-01

While acknowledging the considerable benefits of domain-specific, knowledge-intensive approaches to automated software engineering, it is prudent to carefully examine the costs of such approaches, as well. In adding domain knowledge to a system, a developer makes a commitment to understanding, representing, maintaining, and communicating that knowledge. This substantial overhead is not generally associated with domain-independent approaches. In this paper, I examine the downside of incorporating additional knowledge, and illustrate with examples based on our experiences building the SIGMA system. I also offer some guidelines for developers building domain-specific systems.

Radial Internal Material Handling System (RIMS) for Circular Habitat Volumes

NASA Technical Reports Server (NTRS)

Howe, Alan S.; Haselschwardt, Sally; Bogatko, Alex; Humphrey, Brian; Patel, Amit

2013-01-01

On planetary surfaces, pressurized human habitable volumes will require a means to carry equipment around within the volume of the habitat, regardless of the partial gravity (Earth, Moon, Mars, etc.). On the NASA Habitat Demonstration Unit (HDU), a vertical cylindrical volume, it was determined that a variety of heavy items would need to be carried back and forth from deployed locations to the General Maintenance Work Station (GMWS) when in need of repair, and other equipment may need to be carried inside for repairs, such as rover parts and other external equipment. The vertical cylindrical volume of the HDU lent itself to a circular overhead track and hoist system that allows lifting of heavy objects from anywhere in the habitat to any other point in the habitat interior. In addition, the system is able to hand-off lifted items to other material handling systems through the side hatches, such as through an airlock. The overhead system consists of two concentric circle tracks that have a movable beam between them. The beam has a hoist carriage that can move back and forth on the beam. Therefore, the entire system acts like a bridge crane curved around to meet itself in a circle. The novelty of the system is in its configuration, and how it interfaces with the volume of the HDU habitat. Similar to how a bridge crane allows coverage for an entire rectangular volume, the RIMS system covers a circular volume. The RIMS system is the first generation of what may be applied to future planetary surface vertical cylinder habitats on the Moon or on Mars.

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2014 CFR

2014-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2013 CFR

2013-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

30 CFR 250.907 - Where must I locate foundation boreholes?

Code of Federal Regulations, 2012 CFR

2012-07-01

... soil boring must not exceed 500 feet. (b) For deepwater floating platforms which utilize catenary or..., other points throughout the anchor pattern to establish the soil profile suitable for foundation design...

Distributed Compressive CSIT Estimation and Feedback for FDD Multi-User Massive MIMO Systems

NASA Astrophysics Data System (ADS)

Rao, Xiongbin; Lau, Vincent K. N.

2014-06-01

To fully utilize the spatial multiplexing gains or array gains of massive MIMO, the channel state information must be obtained at the transmitter side (CSIT). However, conventional CSIT estimation approaches are not suitable for FDD massive MIMO systems because of the overwhelming training and feedback overhead. In this paper, we consider multi-user massive MIMO systems and deploy the compressive sensing (CS) technique to reduce the training as well as the feedback overhead in the CSIT estimation. The multi-user massive MIMO systems exhibits a hidden joint sparsity structure in the user channel matrices due to the shared local scatterers in the physical propagation environment. As such, instead of naively applying the conventional CS to the CSIT estimation, we propose a distributed compressive CSIT estimation scheme so that the compressed measurements are observed at the users locally, while the CSIT recovery is performed at the base station jointly. A joint orthogonal matching pursuit recovery algorithm is proposed to perform the CSIT recovery, with the capability of exploiting the hidden joint sparsity in the user channel matrices. We analyze the obtained CSIT quality in terms of the normalized mean absolute error, and through the closed-form expressions, we obtain simple insights into how the joint channel sparsity can be exploited to improve the CSIT recovery performance.

ARGES: an Expert System for Fault Diagnosis Within Space-Based ECLS Systems

NASA Technical Reports Server (NTRS)

Pachura, David W.; Suleiman, Salem A.; Mendler, Andrew P.

1988-01-01

ARGES (Atmospheric Revitalization Group Expert System) is a demonstration prototype expert system for fault management for the Solid Amine, Water Desorbed (SAWD) CO2 removal assembly, associated with the Environmental Control and Life Support (ECLS) System. ARGES monitors and reduces data in real time from either the SAWD controller or a simulation of the SAWD assembly. It can detect gradual degradations or predict failures. This allows graceful shutdown and scheduled maintenance, which reduces crew maintenance overhead. Status and fault information is presented in a user interface that simulates what would be seen by a crewperson. The user interface employs animated color graphics and an object oriented approach to provide detailed status information, fault identification, and explanation of reasoning in a rapidly assimulated manner. In addition, ARGES recommends possible courses of action for predicted and actual faults. ARGES is seen as a forerunner of AI-based fault management systems for manned space systems.

System and method for refurbishing and processing parachutes. [monorial conveyor system

NASA Technical Reports Server (NTRS)

Crowell, R. T. (Inventor)

1980-01-01

A system and method for refurbishing and processing parachutes is disclosed including an overhead monorail conveyor system on which the parachute is suspended for horizontal conveyance. The parachute is first suspended in a partially opened tented configuration wherein open inspection of the canopy is permitted to remove debris and inspect all areas. Following inspection, the parachute is transported by the monorail conveyor to a washing and drying station with the parachute canopy mounted on the conveyor in a systematic arrangement which permits water and air to pass through the ribbon-like materials of the canopy. Following drying, the chute is conveyed into an interior space where it is finally inspected and removed from the monorial conveyor for folding. The chute is once again mounted on the conveyor and conveyed to a packing area.

73. TORPEDO WORK SHOP FORWARD LOOKING AFT SHOWING TORPEDO ...

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

73. TORPEDO WORK SHOP - FORWARD LOOKING AFT SHOWING TORPEDO ELEVATOR, HIGH PRESSURE AIR REDUCING STATION, SCUTTLEBUTT, TORPEDO AFTERBODY WORKSHOP, OVERHEAD CHAIN MOIST AND RAIL SYSTEM AND OVERHEAD SPRINKLER SYSTEM. - U.S.S. HORNET, Puget Sound Naval Shipyard, Sinclair Inlet, Bremerton, Kitsap County, WA

Overhead Bryant's Traction Does Not Improve the Success of Closed Reduction or Limit AVN in Developmental Dysplasia of the Hip.

PubMed

Sucato, Daniel J; De La Rocha, Adriana; Lau, Karlee; Ramo, Brandon A

2017-03-01

Preoperative Bryant's overhead traction before closed reduction (CR) in developmental dysplasia of the hip (DDH) remains controversial and its success in increasing CR rates and reducing avascular necrosis (AVN) rates has not been specifically reported in a large cohort. IRB-approved retrospective study of patients (below 3 y)who were treated with attempted CR for idiopathic DDH from 1980 to 2009. Successful CR was defined as a hip that remained reduced and did not require repeat CR or open reduction. Patients were grouped by age, hip instability [Ortolani positive (reducible) vs. fixed dislocation], and Tonnis classification and rates of successful CR were compared between groups with P<0.05. A total of 342 hips were included with a mean age of 0.9 years (0.2 to 2.8 y) and a mean follow-up of 10.4 years (2.0 to 27.7 y). There were 269 hips with fixed dislocations and 73 Ortolani-positive hips. Traction was used in 276 hips. There was no difference in traction utilization in the 3 age groups (below 1, below 1.5, and below 2 y) for either Ortolani-positive hips (P=0.947) or fixed dislocations (P=0.943). There was no difference in achieving a successful CR comparing traction (60.9%) and no-traction groups (60.6%) (P=1.00). For Ortolani-positive hips, traction did not improve the incidence of a successful CR for any age group: below 1 year: P=0.19; below 1.5 years: P=0.23; and below 2 years: P=0.25. Similarly, fixed dislocation patients had no benefit from traction: below 1 year: P=0.76; below 1.5 years: P=0.82; and below 2 years: P=0.85. Tonnis classification did predict success of CR but had no influence on traction success. There was no difference in the rate of AVN between the traction (18%) and no-traction (8%) groups for all patients (P=0.15). In this retrospective series, preoperative Bryant's traction does not improve the rate of a successful CR for patients with DDH and has no protective effect on the development of AVN of the femoral head. These results

KSC-2009-1330

NASA Image and Video Library

2009-01-26

CAPE CANAVERAL, Fla. – Construction of the towers on Launch Pad 39B at NASA's Kennedy Space Center in Florida continues on the new lightning protection system for the Constellation Program and Ares/Orion launches. Here, a 100-foot fiberglass lightning mast is being prepared to be lifted on top of one of the 500-foot towers. The mast will support a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009.

KSC-2009-1329

NASA Image and Video Library

2009-01-26

CAPE CANAVERAL, Fla. – In the rosy dawn light, construction of the towers on Launch Pad 39B at NASA's Kennedy Space Center in Florida continues on the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009.

KSC-2009-1328

NASA Image and Video Library

2009-01-26

CAPE CANAVERAL, Fla. – In the rosy dawn light, construction of the towers on Launch Pad 39B at NASA's Kennedy Space Center in Florida continues on the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009.

Transmission Line Ampacity Improvements of AltaLink Wind Plant Overhead Tie-Lines Using Weather-Based Dynamic Line Rating

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhattarai, Bishnu P.; Gentle, Jake P.; Hill, Porter

Abstract—Overhead transmission lines (TLs) are conventionally given seasonal ratings based on conservative environmental assumptions. Such an approach often results in underutilization of the line ampacity as the worst conditions prevail only for a short period over a year/season. We presents dynamic line rating (DLR) as an enabling smart grid technology that adaptively computes ratings of TLs based on local weather conditions to utilize additional headroom of existing lines. In particular, general line ampacity state solver utilizes measured weather data for computing the real-time thermal rating of the TLs. The performance of the presented method is demonstrated from a field studymore » of DLR technology implementation on four TL segments at AltaLink, Canada. The performance is evaluated and quantified by comparing the existing static and proposed dynamic line ratings, and the potential benefits of DLR for enhanced transmission assets utilization. For the given line segments, the proposed DLR results in real-time ratings above the seasonal static ratings for most of the time; up to 95.1% of the time, with a mean increase of 72% over static rating.« less

KENNEDY SPACE CENTER, FLA. - In the high bay clean room at the Astrotech Space Operations processing facilities near KSC, workers prepare to attach an overhead crane to NASA’s MESSENGER spacecraft. The spacecraft will be moved to a work stand where employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - In the high bay clean room at the Astrotech Space Operations processing facilities near KSC, workers prepare to attach an overhead crane to NASA’s MESSENGER spacecraft. The spacecraft will be moved to a work stand where employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

KENNEDY SPACE CENTER, FLA. - In the high bay clean room at the Astrotech Space Operations processing facilities near KSC, workers attach an overhead crane to NASA’s MESSENGER spacecraft. The spacecraft will be moved to a work stand where employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

NASA Image and Video Library

2004-03-10

KENNEDY SPACE CENTER, FLA. - In the high bay clean room at the Astrotech Space Operations processing facilities near KSC, workers attach an overhead crane to NASA’s MESSENGER spacecraft. The spacecraft will be moved to a work stand where employees of the Johns Hopkins University Applied Physics Laboratory, builders of the spacecraft, will perform an initial state-of-health check. Then processing for launch can begin, including checkout of the power systems, communications systems and control systems. The thermal blankets will also be attached for flight. MESSENGER - short for MErcury Surface, Space ENvironment, GEochemistry and Ranging - will be launched May 11 on a six-year mission aboard a Boeing Delta II rocket. Liftoff is targeted for 2:26 a.m. EDT on Tuesday, May 11.

Fault-tolerant clock synchronization in distributed systems

NASA Technical Reports Server (NTRS)

Ramanathan, Parameswaran; Shin, Kang G.; Butler, Ricky W.

1990-01-01

Existing fault-tolerant clock synchronization algorithms are compared and contrasted. These include the following: software synchronization algorithms, such as convergence-averaging, convergence-nonaveraging, and consistency algorithms, as well as probabilistic synchronization; hardware synchronization algorithms; and hybrid synchronization. The worst-case clock skews guaranteed by representative algorithms are compared, along with other important aspects such as time, message, and cost overhead imposed by the algorithms. More recent developments such as hardware-assisted software synchronization and algorithms for synchronizing large, partially connected distributed systems are especially emphasized.

Rotor Systems Research Aircraft /RSRA/ canopy explosive severance/fracture

NASA Technical Reports Server (NTRS)

Bement, L. J.

1976-01-01

The Rotor Systems Research Aircraft (RSRA), a compound rotor/fixed-wing aircraft, incorporates an emergency escape system for the three crew members; to achieve unobstructed egress, the overhead acrylic canopies of each crew member will be explosively severed and fractured into predictably small, low-mass pieces. A canopy explosive severance/fracture system was developed under this investigation that included the following system design considerations: selection of canopy and explosive materials, determining the acrylic's explosive severance and fracture characteristics, evaluating the effects of installation variables and temperature, determining the most effective explosive patterns, conducting full-scale, flat and double-curvature canopy tests, and evaluating the effects of back-blast of the explosive into the cockpit.

Data Partitioning and Load Balancing in Parallel Disk Systems

NASA Technical Reports Server (NTRS)

Scheuermann, Peter; Weikum, Gerhard; Zabback, Peter

1997-01-01

Parallel disk systems provide opportunities for exploiting I/O parallelism in two possible waves, namely via inter-request and intra-request parallelism. In this paper we discuss the main issues in performance tuning of such systems, namely striping and load balancing, and show their relationship to response time and throughput. We outline the main components of an intelligent, self-reliant file system that aims to optimize striping by taking into account the requirements of the applications and performs load balancing by judicious file allocation and dynamic redistributions of the data when access patterns change. Our system uses simple but effective heuristics that incur only little overhead. We present performance experiments based on synthetic workloads and real-life traces.

Study on Remote Monitoring System of Crossing and Spanning Tangent Tower

NASA Astrophysics Data System (ADS)

Chen, Da-bing; Zhang, Nai-long; Zhang, Meng-ge; Wang, Ze-hua; Zhang, Yan

2017-05-01

In order to grasp the vibration state of overhead transmission line and ensure the operational security of transmission line, the remote monitoring system of crossing and spanning tangent tower was studied. By use of this system, the displacement, velocity and acceleration of the tower, and the local weather data are collected automatically, displayed on computer of remote monitoring centre through wireless network, real-time collection and transmission of vibration signals are realized. The applying results show that the system is excellent in reliability and accuracy and so on. The system can be used to remote monitoring of transmission tower of UHV power transmission lines and in large spanning areas.

The USL NASA PC R and D interactive presentation development system

NASA Technical Reports Server (NTRS)

Dominick, Wayne D. (Editor); Moreau, Dennis R.

1984-01-01

The Interactive Presentation Development System (IPFS) is a highly interactive system for creating, editing, and displaying video presentation sequences, e.g., for developing and presenting displays of instructional material similiar to overhead transparency or slide presentations. However, since this system is PC-based, users (instructors) can step through sequences forward or backward, focusing attention to areas of the display with special cursor pointers. Additionally, screen displays may be dynamically modified during the presentation to show assignments or to answer questions, much like a traditional blackboard. This system is now implemented at the University of Southwestern Louisiana for use within the piloting phases of the NASA contract work.

Tailoring Systems Engineering Projects for Small Satellite Missions

NASA Technical Reports Server (NTRS)

Horan, Stephen; Belvin, Keith

2013-01-01

NASA maintains excellence in its spaceflight systems by utilizing rigorous engineering processes based on over 50 years of experience. The NASA systems engineering process for flight projects described in NPR 7120.5E was initially developed for major flight projects. The design and development of low-cost small satellite systems does not entail the financial and risk consequences traditionally associated with spaceflight projects. Consequently, an approach is offered to tailoring of the processes such that the small satellite missions will benefit from the engineering rigor without overly burdensome overhead. In this paper we will outline the approaches to tailoring the standard processes for these small missions and describe how it will be applied in a proposed small satellite mission.

Douglas flight deck design philosophy

NASA Technical Reports Server (NTRS)

Oldale, Paul

1990-01-01

The systems experience gained from 17 years of DC-10 operation was used during the design of the MD-11 to automate system operation and reduce crew workload. All functions, from preflight to shutdown at the termination of flight, require little input from the crew. The MD-11 aircraft systems are monitored for proper operation by the Aircraft Systems Controllers (ASC). In most cases, system reconfiguration as a result of a malfunction is automated. Manual input is required for irreversible actions such as engine shutdown, fuel dump, fire agent discharge, or Integrated Drive Generator (IDG) disconnect. During normal operations, when the cockpit is configured for flight, all annunciators on the overhead panel will be extinguished. This Dark Cockpit immediately confirms to the crew that the panels are correctly configured and that no abnormalities are present. Primary systems annunciations are shown in text on the Alert Area of the Engine and Alert Display (EAD). This eliminates the need to scan the overhead. The MD-11 aircraft systems can be manually controlled from the overhead area of the cockpit. The center portion of the overhead panel is composed of the primary aircraft systems panels, which include FUEL, AIR, Electrical (ELEC) and Hydraulic (HYD) systems, which are easily accessible from both flight crew positions. Each Aircraft Systems Controller (ASC) has two automatic channels and a manual mode. All rectangular lights are annunciators. All square lights are combined switches and annunciators called switch/lights. Red switch/lights on the overhead (Level 3 alerts) are for conditions requiring immediate crew action. Amber (Level 2 or Level 1 alerts) indicates a fault or switch out of position requiring awareness or crew interaction. Overhead switches used in normal operating conditions will illuminate blue when in use (Level 0 alerts) such as WING ANTI-ICE - ON. An overhead switch/light with BLACK LETTERING on an amber or red background indicates a system

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks

PubMed Central

Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research. PMID:28135288

A Temporal Credential-Based Mutual Authentication with Multiple-Password Scheme for Wireless Sensor Networks.

PubMed

Liu, Xin; Zhang, Ruisheng; Liu, Qidong

2017-01-01

Wireless sensor networks (WSNs), which consist of a large number of sensor nodes, have become among the most important technologies in numerous fields, such as environmental monitoring, military surveillance, control systems in nuclear reactors, vehicle safety systems, and medical monitoring. The most serious drawback for the widespread application of WSNs is the lack of security. Given the resource limitation of WSNs, traditional security schemes are unsuitable. Approaches toward withstanding related attacks with small overhead have thus recently been studied by many researchers. Numerous studies have focused on the authentication scheme for WSNs, but most of these works cannot achieve the security performance and overhead perfectly. Nam et al. proposed a two-factor authentication scheme with lightweight sensor computation for WSNs. In this paper, we review this scheme, emphasize its drawbacks, and propose a temporal credential-based mutual authentication with a multiple-password scheme for WSNs. Our scheme uses multiple passwords to achieve three-factor security performance and generate a session key between user and sensor nodes. The security analysis phase shows that our scheme can withstand related attacks, including a lost password threat, and the comparison phase shows that our scheme involves a relatively small overhead. In the comparison of the overhead phase, the result indicates that more than 95% of the overhead is composed of communication and not computation overhead. Therefore, the result motivates us to pay further attention to communication overhead than computation overhead in future research.

Rigid hoist articulated grapple system development for enhanced remote maintenance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witham, C.; White, P.; Garin, J.

1979-01-01

Remote maintenance and repair within nuclear environments have become more demanding of remote manipulation equipment in the last few years. A deficiency exists in the array of tools available for dexterous operations of loads in the 180-kg range. The development of a manipulation system with enhanced operator controls is discussed. This system is a six-degree-of-freedom manipulator with bilateral servo control. It is to be attached to a mobile support boom in order to operate throughout the nuclear cell. The manipulator is intended to work in conjunction with light duty servomanipulators, overhead crane systems, and through-the-wall mechanical master slaves.

PAVENET OS: A Compact Hard Real-Time Operating System for Precise Sampling in Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Saruwatari, Shunsuke; Suzuki, Makoto; Morikawa, Hiroyuki

The paper shows a compact hard real-time operating system for wireless sensor nodes called PAVENET OS. PAVENET OS provides hybrid multithreading: preemptive multithreading and cooperative multithreading. Both of the multithreading are optimized for two kinds of tasks on wireless sensor networks, and those are real-time tasks and best-effort ones. PAVENET OS can efficiently perform hard real-time tasks that cannot be performed by TinyOS. The paper demonstrates the hybrid multithreading realizes compactness and low overheads, which are comparable to those of TinyOS, through quantitative evaluation. The evaluation results show PAVENET OS performs 100 Hz sensor sampling with 0.01% jitter while performing wireless communication tasks, whereas optimized TinyOS has 0.62% jitter. In addition, PAVENET OS has a small footprint and low overheads (minimum RAM size: 29 bytes, minimum ROM size: 490 bytes, minimum task switch time: 23 cycles).

Procurement of a fully licensed radioisotope thermoelectric generator transportation system

NASA Astrophysics Data System (ADS)

Adkins, Harold E.; Bearden, Thomas E.

The present transportation system for radioisotope thermoelectric generators and heater units is being developed to comply with all applicable U.S. DOT regulations, including a doubly-contained 'bell jar' concept for the required double-containment of plutonium. Modifications in handling equipment and procedures are entailed by this novel packaging design, and will affect high-capacity forklifts, overhead cranes, He-backfilling equipment, etc. Attention is given to the design constraints involved, and to the Federal procurement process.

Power system analysis of Hanlim superconducting HVDC system using real time digital simulator

NASA Astrophysics Data System (ADS)

Won, Y. J.; Kim, J. G.; Kim, A. R.; Kim, G. H.; Park, M.; Yu, I. K.; Sim, K. D.; Cho, J.; Lee, S.; Jeong, K. W.; Watanabe, K.

2011-11-01

Jeju island is located approximately 100 km south from the mainland of Korea, and had a peak load of about 553 MW in 2008. The demand increases 7.2% a year over the last 5 years. Since the wind profiles of Jeju island are more favorable than mainland of Korea, many companies have shown interest in the wind power business at the Jeju island. Moreover KEPCO has a plan for renewable energy test too whose power will be delivered by HVDC system. One kilometer length of total 8 km was designed as superconducting DC cable. Rest 7 km will be the conventional overhead line. In this paper, the authors have developed a simulation model of the power network around 8 km HVDC system using real time digital simulator (RTDS).

Summary of JIP

DOT National Transportation Integrated Search

2008-04-01

The SCRIM (Steel Catenary Riser Integrity Management) Joint Industry Project was an industry-sponsored initiative, managed and delivered by MCS, to develop industry guidelines for the integrity management of offshore risers. The original scope of the...

Software Voting in Asynchronous NMR (N-Modular Redundancy) Computer Structures.

DTIC Science & Technology

1983-05-06

added reliability is exchanged for increased system cost and decreased throughput. Some applications require extremely reliable systems, so the only...not the other way around. Although no systems proidc abstract voting yet. as more applications are written for NMR systems, the programmers are going...throughput goes down, the overhead goes up. Mathematically : Overhead= Non redundant Throughput- Actual Throughput (1) In this section, the actual throughput

RESTOP: Retaining External Peripheral State in Intermittently-Powered Sensor Systems.

PubMed

Rodriguez Arreola, Alberto; Balsamo, Domenico; Merrett, Geoff V; Weddell, Alex S

2018-01-10

Energy harvesting sensor systems typically incorporate energy buffers (e.g., rechargeable batteries and supercapacitors) to accommodate fluctuations in supply. However, the presence of these elements limits the miniaturization of devices. In recent years, researchers have proposed a new paradigm, transient computing, where systems operate directly from the energy harvesting source and allow computation to span across power cycles, without adding energy buffers. Various transient computing approaches have addressed the challenge of power intermittency by retaining the processor's state using non-volatile memory. However, no generic approach has yet been proposed to retain the state of peripherals external to the processing element. This paper proposes RESTOP, flexible middleware which retains the state of multiple external peripherals that are connected to a computing element (i.e., a microcontroller) through protocols such as SPI or I 2 C. RESTOP acts as an interface between the main application and the peripheral, which keeps a record, at run-time, of the transmitted data in order to restore peripheral configuration after a power interruption. RESTOP is practically implemented and validated using three digitally interfaced peripherals, successfully restoring their configuration after power interruptions, imposing a maximum time overhead of 15% when configuring a peripheral. However, this represents an overhead of only 0.82% during complete execution of our typical sensing application, which is substantially lower than existing approaches.

RESTOP: Retaining External Peripheral State in Intermittently-Powered Sensor Systems

PubMed Central

Rodriguez Arreola, Alberto; Balsamo, Domenico

2018-01-01

Energy harvesting sensor systems typically incorporate energy buffers (e.g., rechargeable batteries and supercapacitors) to accommodate fluctuations in supply. However, the presence of these elements limits the miniaturization of devices. In recent years, researchers have proposed a new paradigm, transient computing, where systems operate directly from the energy harvesting source and allow computation to span across power cycles, without adding energy buffers. Various transient computing approaches have addressed the challenge of power intermittency by retaining the processor’s state using non-volatile memory. However, no generic approach has yet been proposed to retain the state of peripherals external to the processing element. This paper proposes RESTOP, flexible middleware which retains the state of multiple external peripherals that are connected to a computing element (i.e., a microcontroller) through protocols such as SPI or I2C. RESTOP acts as an interface between the main application and the peripheral, which keeps a record, at run-time, of the transmitted data in order to restore peripheral configuration after a power interruption. RESTOP is practically implemented and validated using three digitally interfaced peripherals, successfully restoring their configuration after power interruptions, imposing a maximum time overhead of 15% when configuring a peripheral. However, this represents an overhead of only 0.82% during complete execution of our typical sensing application, which is substantially lower than existing approaches. PMID:29320441

KSC-05pd2558

NASA Image and Video Library

2005-12-05

KENNEDY SPACE CENTER, FLA. - The Lockheed Martin Atlas V rocket (center) undergoes a tanking test on Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The rocket was fully fueled with liquid hydrogen, liquid oxygen and RP 1 kerosene fuel. Seen surrounding the rocket are lightning towers that support the catenary wire that provides lightning protection. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch during a 35-day window that opens Jan. 11, and fly through the Pluto system as early as summer 2015.

KSC-05pd2559

NASA Image and Video Library

2005-12-05

KENNEDY SPACE CENTER, FLA. - The Lockheed Martin Atlas V rocket (center) undergoes a tanking test on Launch Complex 41 at Cape Canaveral Air Force Station in Florida. The rocket was fully fueled with liquid hydrogen, liquid oxygen and RP 1 kerosene fuel. Seen surrounding the rocket are lightning towers that support the catenary wire that provides lightning protection. The Atlas V is the launch vehicle for NASA’s New Horizons spacecraft, scheduled to launch during a 35-day window that opens Jan. 11, and fly through the Pluto system as early as summer 2015.

Simulation of Trolleybus Traction Induction Drive With Supercapacitor Energy Storage System

NASA Astrophysics Data System (ADS)

Brazis, V.; Latkovskis, L.; Grigans, L.

2010-01-01

The article considers the possibilities of saving the regenerative braking energy in Škoda 24Tr type trolleybuses by installing the onboard supercapacitor energy storage system (ESS) and improving its performance with automated switching to the autonomous traction mode. Proposed is an ESS control system with constant DC bus voltage in the supercapacitor charging mode and supercapacitor current proportional to the AC drive current in the discharging mode. The authors investigate stability of the trolleybus ESS control system operating together with AC traction drive in various overhead voltage failure modes. The co-simulation of ESS operation was done by Matlab/Simulink AC drive and PSIM ESS continuous models.

Lightning Effects in the Payload Changeout Room

NASA Technical Reports Server (NTRS)

Thomas, Garland L.; Fisher, Franklin A.; Collier, Richard S.; Medelius, Pedro J.

1997-01-01

Analytical and empirical studies have been performed to provide better understanding of the electromagnetic environment inside the Payload Changeout Room and Orbiter payload bay resulting from lightning strikes to the launch pad lightning protection system. The analytical studies consisted of physical and mathematical modeling of the pad structure and the Payload Changeout Room. Empirical testing was performed using a lightning simulator to simulate controlled (8 kA) lightning strikes to the catenary wire lightning protection system. In addition to the analyses and testing listed above, an analysis of the configuration with the vehicle present was conducted, in lieu of testing, by the Finite Difference, Time Domain method.

KSC-2009-1300

NASA Image and Video Library

2009-01-22

CAPE CANAVERAL, Fla. – A giant crane is used to add additional segments to the new lightning towers on Launch Pad 39B at NASA's Kennedy Space Center in Florida. Three new lightning towers on the pad will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Photo credit: NASA/Kim Shiflett

KSC-2009-1004

NASA Image and Video Library

2009-01-02

CAPE CANAVERAL, Fla. – CAPE CANAVERAL, Fla. -- On Launch Pad 39B at NASA's Kennedy Space Center in Florida, another lightning tower is being constructed as part of the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Troy Cryder

KSC-2009-1003

NASA Image and Video Library

2009-01-02

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, a crane completes construction of one of the towers in the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Troy Cryder

The fall of a viscous thread onto a moving surface: a ‘fluid-mechanical sewing machine’

NASA Astrophysics Data System (ADS)

Chiu-Webster, S.; Lister, J. R.

2006-12-01

A viscous thread falling onto a steadily moving horizontal belt shows a surprisingly complex range of behaviour in experiments. Low belt speeds produce coiling, as might be expected from the behaviour of a thread falling onto a stationary surface. High belt speeds produce a steady thread, whose shape is predicted well by theory developed to describe a stretching viscous catenary with surface tension and inertia. Intermediate belt speeds show several novel modes of oscillation, which lay down a wide variety of patterns on the belt. The patterns include meanders, side kicks, slanted loops, braiding, figures-of-eight, Ws, and also period-doubled versions of figures-of-eight, meanders and coiling. The experimental boundary between steady and unsteady behaviour occurs at a slightly lower belt speed than the loss of the steady solution for a stretching catenary.

Subirrigation reduces water use, nitrogen loss, and moss growth in a container nursery

Treesearch

R. Kasten Dumroese; Jeremy R. Pinto; Douglass F. Jacobs; Anthony S. Davis; Baron Horiuchi

2006-01-01

With about half the amount of water, subirrigated Metrosideros polymorpha Gaud. (Myrtaceae) grown 9 mo in a greenhouse were similar to those irrigated with an existing fixed overhead irrigation system; moss growth was about 3X greater in the fixed overhead system after 3 mo. Moss growth was affected by the rate of preplant controlled release fertilizer added (more...

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

NASA Image and Video Library

2003-09-05

KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility, one of two orbital maneuvering system (OMS) pods removed from Endeavour is suspended overhead. The OMS pods are attached to the upper aft fuselage left and right sides. Fabricated primarily of graphite epoxy composite and aluminum, each pod is 21.8 feet long and 11.37 feet wide at its aft end and 8.41 feet wide at its forward end, with a surface area of approximately 435 square feet. Each pod houses the Reaction Control System propulsion components used for inflight maneuvering and is attached to the aft fuselage with 11 bolts. OMS pods are removed during Orbiter Major Modifications. Once removed, the OMS pods undergo in-depth structural inspections, system checks and the thrusters are changed out.

A Solid-State Fault Current Limiting Device for VSC-HVDC Systems

NASA Astrophysics Data System (ADS)

Larruskain, D. Marene; Zamora, Inmaculada; Abarrategui, , Oihane; Iturregi, Araitz

2013-08-01

Faults in the DC circuit constitute one of the main limitations of voltage source converter VSC-HVDC systems, as the high fault currents can damage seriously the converters. In this article, a new design for a fault current limiter (FCL) is proposed, which is capable of limiting the fault current as well as interrupting it, isolating the DC grid. The operation of the proposed FCL is analysed and verified with the most usual faults that can occur in overhead lines.

LDEF grappled by remote manipulator system (RMS) during STS-32 retrieval

NASA Image and Video Library

1990-01-20

This view taken through overhead window W7 on Columbia's, Orbiter Vehicle (OV) 102's, aft flight deck shows the Long Duration Exposure Facility (LDEF) in the grasp of the remote manipulator system (RMS) during STS-32 retrieval activities. Other cameras at eye level were documenting the bus-sized spacecraft at various angles as the RMS manipulated LDEF for a lengthy photo survey. The glaring celestial body in the upper left is the sun with the Earth's surface visible below.

48 CFR 1352.215-76 - Cost or pricing data.

Code of Federal Regulations, 2014 CFR

2014-10-01

...: The offeror shall list the categories of professional or technical personnel required to perform the....—should be discussed. (3) Overhead Costs. Generally, the offeror's accounting system and estimating... in accordance with generally accepted accounting principles, will be accepted. Proposed overhead...

48 CFR 1352.215-76 - Cost or pricing data.

Code of Federal Regulations, 2011 CFR

2011-10-01

...: The offeror shall list the categories of professional or technical personnel required to perform the....—should be discussed. (3) Overhead Costs. Generally, the offeror's accounting system and estimating... in accordance with generally accepted accounting principles, will be accepted. Proposed overhead...

48 CFR 1352.215-76 - Cost or pricing data.

Code of Federal Regulations, 2010 CFR

2010-10-01

...: The offeror shall list the categories of professional or technical personnel required to perform the....—should be discussed. (3) Overhead Costs. Generally, the offeror's accounting system and estimating... in accordance with generally accepted accounting principles, will be accepted. Proposed overhead...

48 CFR 1352.215-76 - Cost or pricing data.

Code of Federal Regulations, 2013 CFR

2013-10-01

...: The offeror shall list the categories of professional or technical personnel required to perform the....—should be discussed. (3) Overhead Costs. Generally, the offeror's accounting system and estimating... in accordance with generally accepted accounting principles, will be accepted. Proposed overhead...

48 CFR 1352.215-76 - Cost or pricing data.

Code of Federal Regulations, 2012 CFR

2012-10-01

...: The offeror shall list the categories of professional or technical personnel required to perform the....—should be discussed. (3) Overhead Costs. Generally, the offeror's accounting system and estimating... in accordance with generally accepted accounting principles, will be accepted. Proposed overhead...

Understanding security failures of two authentication and key agreement schemes for telecare medicine information systems.

PubMed

Mishra, Dheerendra

2015-03-01

Smart card based authentication and key agreement schemes for telecare medicine information systems (TMIS) enable doctors, nurses, patients and health visitors to use smart cards for secure login to medical information systems. In recent years, several authentication and key agreement schemes have been proposed to present secure and efficient solution for TMIS. Most of the existing authentication schemes for TMIS have either higher computation overhead or are vulnerable to attacks. To reduce the computational overhead and enhance the security, Lee recently proposed an authentication and key agreement scheme using chaotic maps for TMIS. Xu et al. also proposed a password based authentication and key agreement scheme for TMIS using elliptic curve cryptography. Both the schemes provide better efficiency from the conventional public key cryptography based schemes. These schemes are important as they present an efficient solution for TMIS. We analyze the security of both Lee's scheme and Xu et al.'s schemes. Unfortunately, we identify that both the schemes are vulnerable to denial of service attack. To understand the security failures of these cryptographic schemes which are the key of patching existing schemes and designing future schemes, we demonstrate the security loopholes of Lee's scheme and Xu et al.'s scheme in this paper.

A database paradigm for the management of DICOM-RT structure sets using a geographic information system

NASA Astrophysics Data System (ADS)

Shao, Weber; Kupelian, Patrick A.; Wang, Jason; Low, Daniel A.; Ruan, Dan

2014-03-01

We devise a paradigm for representing the DICOM-RT structure sets in a database management system, in such way that secondary calculations of geometric information can be performed quickly from the existing contour definitions. The implementation of this paradigm is achieved using the PostgreSQL database system and the PostGIS extension, a geographic information system commonly used for encoding geographical map data. The proposed paradigm eliminates the overhead of retrieving large data records from the database, as well as the need to implement various numerical and data parsing routines, when additional information related to the geometry of the anatomy is desired.

Bulk material handling system

DOEpatents

Kleysteuber, William K.; Mayercheck, William D.

1979-01-01

This disclosure relates to a bulk material handling system particularly adapted for underground mining and includes a monorail supported overhead and carrying a plurality of conveyors each having input and output end portions with the output end portion of a first of the conveyors positioned above an input end portion of a second of the conveyors, a device for imparting motion to the conveyors to move the material from the input end portions toward the output end portions thereof, a device for supporting at least one of the input and output end portions of the first and second conveyors from the monorail, and the supporting device including a plurality of trolleys rollingly supported by the monorail whereby the conveyors can be readily moved therealong.

Validation of Objective Based Measures and Development of a Performance-Based Ranking Method for Load Carriage Systems

DTIC Science & Technology

2001-05-01

Shoulder Discomfort, March Thermal Comfort z * Front Mobility, Overhead Mobility, March Thermal Comfort r Moment (Amp, Nm/kg) x * Torsional Mobility...0 Fit El Manoeuverability U Acceptability M Integration 0 Mobility 0 Physical Comfort 0 Thermal Comfort Figure 3. Overall Ratings for Four Systems. A... Thermal Comfort ) Total 71.1 % Factor 1 described the balance and general ability to move with the pack in place. Variables included lateral bending

KSC-2009-1005

NASA Image and Video Library

2009-01-02

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, a crane (at left) completes construction of one of the towers in the new lightning protection system for the Constellation Program and Ares/Orion launches. At right, another tower is being constructed. Each of the three new lightning towers will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Troy Cryder

KSC-2009-1563

NASA Image and Video Library

2009-02-12

CAPE CANAVERAL, Fla. – A lightning mast remains to be lifted atop the third and final lightning tower erected on Launch Pad 39B at NASA's Kennedy Space Center. Three towers surround the pad. The new lightning protection system is being built for the Constellation Program and Ares/Orion launches. Each of the towers is 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Jack Pfaller

KSC-2009-1008

NASA Image and Video Library

2009-01-02

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, a crane places the 100-foot fiberglass mast atop the new lightning tower constructed on the pad. The towers are part of the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with the additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Kim Shiflett

KSC-2009-1006

NASA Image and Video Library

2009-01-02

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, a crane places the 100-foot fiberglass mast atop the new lightning tower constructed on the pad. The towers are part of the new lightning protection system for the Constellation Program and Ares/Orion launches. Each of the three new lightning towers will be 500 feet tall with the additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Kim Shiflett

High-performance parallel interface to synchronous optical network gateway

DOEpatents

St. John, Wallace B.; DuBois, David H.

1998-08-11

A digital system provides sending and receiving gateways for HIPPI interfaces. Electronic logic circuitry formats data signals and overhead signals in a data frame that is suitable for transmission over a connecting fiber optic link. Multiplexers route the data and overhead signals to a framer module. The framer module allocates the data and overhead signals to a plurality of 9-byte words that are arranged in a selected protocol. The formatted words are stored in a storage register for output through the gateway.

KSC-2009-1299

NASA Image and Video Library

2009-01-22

CAPE CANAVERAL, Fla. – Progress is being made on construction of the new lightning towers on Launch Pad 39B at NASA's Kennedy Space Center in Florida. New sections are being added with the help of a giant crane. Three new lightning towers on the pad will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Photo credit: NASA/Kim Shiflett

KSC-2009-1301

NASA Image and Video Library

2009-01-22

CAPE CANAVERAL, Fla. – Brilliant beams of sunlight bounce off the new lightning tower under construction on Launch Pad 39B at NASA's Kennedy Space Center in Florida. New sections are being added with the help of a giant crane (at right). Three new lightning towers on the pad will be 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Photo credit: NASA/Kim Shiflett

KSC-2010-4941

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the rotating service structure (RSS) on Launch Pad 39B is being dismantled. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4942

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, crews are dismantling the rotating service structure (RSS) on Launch Pad 39B. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4946

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, crews are dismantling the rotating service structure (RSS) on Launch Pad 39B. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4944

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, crews are dismantling the rotating service structure (RSS) on Launch Pad 39B. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4943

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the rotating service structure (RSS) on Launch Pad 39B is being dismantled. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4945

NASA Image and Video Library

2010-09-30

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, the rotating service structure (RSS) on Launch Pad 39B is being dismantled. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jim Grossmann

KSC-2010-4987

NASA Image and Video Library

2010-10-04

CAPE CANAVERAL, Fla. -- At NASA's Kennedy Space Center in Florida, crews continue dismantling the rotating service structure (RSS) on Launch Pad 39B. Sand, reinforcing steel and large wooden mats were put down under the RSS to protect the structure's concrete from falling debris during deconstruction. Starting in 2009, the structure at the pad was no longer needed for NASA's Space Shuttle Program, so it is being restructured for future use. The new design will feature a "clean pad" for rockets to come with their own launcher, making it more versatile for a number of vehicles. The new lightning protection system, consisting of three lightning towers and a wire catenary system will remain. Photo credit: NASA/Jack Pfaller

LEVELS OF EXTREMELY LOW-FREQUENCY ELECTRIC AND MAGNETIC FIELDS FROM OVERHEAD POWER LINES IN THE OUTDOOR ENVIRONMENT OF RAMALLAH CITY-PALESTINE.

PubMed

Abuasbi, Falastine; Lahham, Adnan; Abdel-Raziq, Issam Rashid

2018-05-01

In this study, levels of extremely low-frequency electric and magnetic fields originated from overhead power lines were investigated in the outdoor environment in Ramallah city, Palestine. Spot measurements were applied to record fields intensities over 6-min period. The Spectrum Analyzer NF-5035 was used to perform measurements at 1 m above ground level and directly underneath 40 randomly selected power lines distributed fairly within the city. Levels of electric fields varied depending on the line's category (power line, transformer or distributor), a minimum mean electric field of 3.9 V/m was found under a distributor line, and a maximum of 769.4 V/m under a high-voltage power line (66 kV). However, results of electric fields showed a log-normal distribution with the geometric mean and the geometric standard deviation of 35.9 and 2.8 V/m, respectively. Magnetic fields measured at power lines, on contrast, were not log-normally distributed; the minimum and maximum mean magnetic fields under power lines were 0.89 and 3.5 μT, respectively. As a result, none of the measured fields exceeded the ICNIRP's guidelines recommended for general public exposures to extremely low-frequency fields.

Partial rotator cuff repair and biceps tenotomy for the treatment of patients with massive cuff tears and retained overhead elevation: midterm outcomes with a minimum 5 years of follow-up.

PubMed

Cuff, Derek J; Pupello, Derek R; Santoni, Brandon G

2016-11-01

A subset of patients with massive irreparable rotator cuff tears present with retained overhead elevation and pain as their primary complaint. Our aim was to evaluate the outcomes of partial arthroscopic rotator cuff repair with biceps tenotomy and to report the failure rate of this procedure for patients with >5 years of follow-up. Thirty-four patients underwent partial rotator cuff repair and biceps tenotomy for treatment of a massive rotator cuff tear. Patients had preoperative active forward elevation >120° and no radiographic evidence of glenohumeral arthritis. Patients were followed up clinically and radiographically, and 28 patients had a minimum of 5 years of follow-up. Failure was defined as an American Shoulder and Elbow Surgeons score of <70, loss of active elevation >90°, or revision to reverse shoulder arthroplasty during the study period. Patients demonstrated improvements in average preoperative to postoperative American Shoulder and Elbow Surgeons scores (46.6 to 79.3 [P < .001]) and Simple Shoulder Test scores (5.7 to 9.1 [P < .001]) along with decrease in visual analog scale for pain scores (6.9 to 1.9 [P < .001]). No significant change in forward elevation (168° to 154° [P = .07]), external rotation (38° to 39° [P = 1.0]), or internal rotation (84% to 80% [P = 1.0]) was identified; 36% of patients had progression of the Hamada stage. The failure rate was 29%; 75% of patients were satisfied with their index procedure. Partial rotator cuff repair and biceps tenotomy for patients with massive irreparable rotator cuff tears with retained overhead elevation and pain as the primary complaint produced reasonable outcomes at midterm follow-up of at least 5 years. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

48 CFR 3416.702 - Basic agreements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Basic agreements. 3416.702... CONTRACTING METHODS AND CONTRACT TYPES TYPES OF CONTRACTS Agreements 3416.702 Basic agreements. (a)-(d) [Reserved] (e) Negotiated overhead rates. Basic agreements may include negotiated overhead rates for cost...

The use of soil pollen to determine the sex of overhead individuals of a temperate dioecious shrub.

PubMed

Sugiyama, Anna; Shichi, Koji; Masaki, Takashi; Hubbell, Stephen P

2017-04-01

In dioecious species, determining the sex of individual plants from one-time phenological observations is rarely feasible when some individuals capable of reproducing are not flowering or fruiting at the time of observation. Currently, sexing those individuals requires long-term phenological data on individuals and populations, but such data are rarely available or feasible to collect. We tested the hypothesis that differences in soil pollen concentrations beneath the crowns of female and male plants would exist and be sufficient to reliably determine the sex of the individual plant overhead in a dioecious species. We predicted that soil pollen concentrations beneath male plants would be significantly higher than beneath female plants because only males produce pollen and pollen should accumulate in the soil underneath the male plants over repeated flowering events. We collected samples from surface soil under both sexes of the insect-pollinated dioecious shrub, Aucuba japonica (Garryaceae). Pollen grains were present in surface soil in both Oe and A horizons, and mean pollen concentration under males was significantly higher than under females. Pollen concentrations beneath males were positively correlated with male plant height, potentially reflecting greater pollen production by larger individuals. Considering the small plant size and relatively low pollen production of A. japonica , this method may hold promise for sexing other dioecious species in the absence of direct phenological data. Our phenology-free and relatively low-cost method for sexing dioecious plants may be especially useful in tropical forests where many species are dioecious. © 2017 Botanical Society of America.

Resilient Systemics to Telehealth Support for Clinical Psychiatry and Psychology.

PubMed

Fiorini, Rodolfo A; De Giacomo, Piero; L'Abate, Luciano

2015-01-01

Reliably expanding our clinical practice and lowering our overhead with telepsychiatry, telepsychology, distance counseling and online therapy, requires resilient and antifragile system and tools. When utilized appropriately these technologies may provide greater access to needed services to include more reliable treatment, consultation, supervision, and training. The wise and proper use of technology is fundamental to create and boost outstanding social results. We present, as an example, the main steps to achieve application resilience and antifragility at system level, for diagnostic and therapeutic telepractice and telehealth support, devoted to psychiatry and psychology application. This article presents a number of innovations that can take psychotherapy treatment, supervision, training, and research forward, towards increased effectiveness application.

airborne data analysis/monitor system

NASA Technical Reports Server (NTRS)

Stephison, D. B.

1981-01-01

An Airborne Data Analysis/Monitor System (ADAMS), a ROLM 1666 computer based system installed onboard test airplanes used during experimental testing is evaluated. In addition to the 1666 computer, the ADAMS hardware includes a DDC System 90 fixed head disk and a Miltape DD400 floppy disk. Boeing designed a DMA interface to the data acquisition system and an intelligent terminal to reduce system overhead and simplify operator commands. The ADAMS software includes RMX/RTOS and both ROLM FORTRAN and assembly language are used. The ADAMS provides real time displays that enable onboard test engineers to make rapid decisions about test conduct thus reducing the cost and time required to certify new model airplanes, and improved the quality of data derived from the test, leading to more rapid development of improvements resulting in quieter, safer, and more efficient airplanes. The availability of airborne data processing removes most of the weather and geographical restrictions imposed by telemetered flight test data systems. A data base is maintained to describe the airplane, the data acquisition system, the type of testing, and the conditions under which the test is performed.

VME rollback hardware for time warp multiprocessor systems

NASA Technical Reports Server (NTRS)

Robb, Michael J.; Buzzell, Calvin A.

1992-01-01

The purpose of the research effort is to develop and demonstrate innovative hardware to implement specific rollback and timing functions required for efficient queue management and precision timekeeping in multiprocessor discrete event simulations. The previously completed phase 1 effort demonstrated the technical feasibility of building hardware modules which eliminate the state saving overhead of the Time Warp paradigm used in distributed simulations on multiprocessor systems. The current phase 2 effort will build multiple pre-production rollback hardware modules integrated with a network of Sun workstations, and the integrated system will be tested by executing a Time Warp simulation. The rollback hardware will be designed to interface with the greatest number of multiprocessor systems possible. The authors believe that the rollback hardware will provide for significant speedup of large scale discrete event simulation problems and allow multiprocessors using Time Warp to dramatically increase performance.

Cooling Computers.

ERIC Educational Resources Information Center

Birken, Marvin N.

1967-01-01

Numerous decisions must be made in the design of computer air conditioning, each determined by a combination of economics, physical, and esthetic characteristics, and computer requirements. Several computer air conditioning systems are analyzed--(1) underfloor supply and overhead return, (2) underfloor plenum and overhead supply with computer unit…

General view of the flight deck of the orbiter Discovery ...

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

General view of the flight deck of the orbiter Discovery looking forward and overhead at the overhead instrumentation and control panels. This view was taken at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

Level 1 Daq System for Kloe

NASA Astrophysics Data System (ADS)

Aloisio, A.; Cavaliere, S.; Cevenini, F.; Della Volpe, D.; Merola, L.; Anastasio, A.; Fiore, D. J.

KLOE is a general purpose detector optimized to observe CP violation in K0 decays. This detector will be installed at the DAΦNE Φ-factory, in Frascati (Italy) and it is expected to run at the end of 1997. The KLOE DAQ system can be divided mainly into the front-end fast readout section (the Level 1 DAQ), the FDDI Switch and the processor farm. The total bandwidth requirement is estimated to be of the order of 50 Mbyte/s. In this paper, we describe the Level 1 DAQ section, which is based on custom protocols and hardware controllers, developed to achieve high data transfer rates and event building capabilities without software overhead.

Ant Colony Optimization for Mapping, Scheduling and Placing in Reconfigurable Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrandi, Fabrizio; Lanzi, Pier Luca; Pilato, Christian

Modern heterogeneous embedded platforms, com- posed of several digital signal, application specific and general purpose processors, also include reconfigurable devices support- ing partial dynamic reconfiguration. These devices can change the behavior of some of their parts during execution, allowing hardware acceleration of more sections of the applications. Never- theless, partial dynamic reconfiguration imposes severe overheads in terms of latency. For such systems, a critical part of the design phase is deciding on which processing elements (mapping) and when (scheduling) executing a task, but also how to place them on the reconfigurable device to guarantee the most efficient reuse of themore » programmable logic. In this paper we propose an algorithm based on Ant Colony Optimization (ACO) that simultaneously executes the scheduling, the mapping and the linear placing of tasks, hiding reconfiguration overheads through prefetching. Our heuristic gradually constructs solutions and then searches around the best ones, cutting out non-promising areas of the design space. We show how to consider the partial dynamic reconfiguration constraints in the scheduling, placing and mapping problems and compare our formulation to other heuristics that address the same problems. We demonstrate that our proposal is more general and robust, and finds better solutions (16.5% in average) with respect to competing solutions.« less

The storage system of PCM based on random access file system

NASA Astrophysics Data System (ADS)

Han, Wenbing; Chen, Xiaogang; Zhou, Mi; Li, Shunfen; Li, Gezi; Song, Zhitang

2016-10-01

Emerging memory technologies such as Phase change memory (PCM) tend to offer fast, random access to persistent storage with better scalability. It's a hot topic of academic and industrial research to establish PCM in storage hierarchy to narrow the performance gap. However, the existing file systems do not perform well with the emerging PCM storage, which access storage medium via a slow, block-based interface. In this paper, we propose a novel file system, RAFS, to bring about good performance of PCM, which is built in the embedded platform. We attach PCM chips to the memory bus and build RAFS on the physical address space. In the proposed file system, we simplify traditional system architecture to eliminate block-related operations and layers. Furthermore, we adopt memory mapping and bypassed page cache to reduce copy overhead between the process address space and storage device. XIP mechanisms are also supported in RAFS. To the best of our knowledge, we are among the first to implement file system on real PCM chips. We have analyzed and evaluated its performance with IOZONE benchmark tools. Our experimental results show that the RAFS on PCM outperforms Ext4fs on SDRAM with small record lengths. Based on DRAM, RAFS is significantly faster than Ext4fs by 18% to 250%.

Christiaan Huygens and the Problem of the Hanging Chain

ERIC Educational Resources Information Center

Bukowski, John F.

2008-01-01

The seventeen-year-old Christiaan Huygens was the first to prove that a hanging chain did not take the form of the parabola, as was commonly thought in the early seventeenth century. We will examine Huygen's geometrical proof, and we will investigate the later history of the catenary.

75 FR 26743 - Pacific Gas and Electric Company; Notice of Environmental Site Review and Technical Meetings To...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-12

... Ocean, 2.5 to 3.0 nautical miles west of Manila on Samoa Peninsula of Humboldt Bay, near Eureka... Conversion devises (WEC), including multi-point catenary moorings and anchors; (2) marker buoys, navigation... interconnection to the electrical grid; and (6) appurtenant facilities. WEC types that may be installed may...

A direct-to-drive neural data acquisition system.

PubMed

Kinney, Justin P; Bernstein, Jacob G; Meyer, Andrew J; Barber, Jessica B; Bolivar, Marti; Newbold, Bryan; Scholvin, Jorg; Moore-Kochlacs, Caroline; Wentz, Christian T; Kopell, Nancy J; Boyden, Edward S

2015-01-01

Driven by the increasing channel count of neural probes, there is much effort being directed to creating increasingly scalable electrophysiology data acquisition (DAQ) systems. However, all such systems still rely on personal computers for data storage, and thus are limited by the bandwidth and cost of the computers, especially as the scale of recording increases. Here we present a novel architecture in which a digital processor receives data from an analog-to-digital converter, and writes that data directly to hard drives, without the need for a personal computer to serve as an intermediary in the DAQ process. This minimalist architecture may support exceptionally high data throughput, without incurring costs to support unnecessary hardware and overhead associated with personal computers, thus facilitating scaling of electrophysiological recording in the future.

A direct-to-drive neural data acquisition system

PubMed Central

Kinney, Justin P.; Bernstein, Jacob G.; Meyer, Andrew J.; Barber, Jessica B.; Bolivar, Marti; Newbold, Bryan; Scholvin, Jorg; Moore-Kochlacs, Caroline; Wentz, Christian T.; Kopell, Nancy J.; Boyden, Edward S.

2015-01-01

Driven by the increasing channel count of neural probes, there is much effort being directed to creating increasingly scalable electrophysiology data acquisition (DAQ) systems. However, all such systems still rely on personal computers for data storage, and thus are limited by the bandwidth and cost of the computers, especially as the scale of recording increases. Here we present a novel architecture in which a digital processor receives data from an analog-to-digital converter, and writes that data directly to hard drives, without the need for a personal computer to serve as an intermediary in the DAQ process. This minimalist architecture may support exceptionally high data throughput, without incurring costs to support unnecessary hardware and overhead associated with personal computers, thus facilitating scaling of electrophysiological recording in the future. PMID:26388740

A numerical method for solving systems of linear ordinary differential equations with rapidly oscillating solutions

NASA Technical Reports Server (NTRS)

Bernstein, Ira B.; Brookshaw, Leigh; Fox, Peter A.

1992-01-01

The present numerical method for accurate and efficient solution of systems of linear equations proceeds by numerically developing a set of basis solutions characterized by slowly varying dependent variables. The solutions thus obtained are shown to have a computational overhead largely independent of the small size of the scale length which characterizes the solutions; in many cases, the technique obviates series solutions near singular points, and its known sources of error can be easily controlled without a substantial increase in computational time.

L-Py: An L-System Simulation Framework for Modeling Plant Architecture Development Based on a Dynamic Language

PubMed Central

Boudon, Frédéric; Pradal, Christophe; Cokelaer, Thomas; Prusinkiewicz, Przemyslaw; Godin, Christophe

2012-01-01

The study of plant development requires increasingly powerful modeling tools to help understand and simulate the growth and functioning of plants. In the last decade, the formalism of L-systems has emerged as a major paradigm for modeling plant development. Previous implementations of this formalism were made based on static languages, i.e., languages that require explicit definition of variable types before using them. These languages are often efficient but involve quite a lot of syntactic overhead, thus restricting the flexibility of use for modelers. In this work, we present an adaptation of L-systems to the Python language, a popular and powerful open-license dynamic language. We show that the use of dynamic language properties makes it possible to enhance the development of plant growth models: (i) by keeping a simple syntax while allowing for high-level programming constructs, (ii) by making code execution easy and avoiding compilation overhead, (iii) by allowing a high-level of model reusability and the building of complex modular models, and (iv) by providing powerful solutions to integrate MTG data-structures (that are a common way to represent plants at several scales) into L-systems and thus enabling to use a wide spectrum of computer tools based on MTGs developed for plant architecture. We then illustrate the use of L-Py in real applications to build complex models or to teach plant modeling in the classroom. PMID:22670147

L-py: an L-system simulation framework for modeling plant architecture development based on a dynamic language.

PubMed

Boudon, Frédéric; Pradal, Christophe; Cokelaer, Thomas; Prusinkiewicz, Przemyslaw; Godin, Christophe

2012-01-01

The study of plant development requires increasingly powerful modeling tools to help understand and simulate the growth and functioning of plants. In the last decade, the formalism of L-systems has emerged as a major paradigm for modeling plant development. Previous implementations of this formalism were made based on static languages, i.e., languages that require explicit definition of variable types before using them. These languages are often efficient but involve quite a lot of syntactic overhead, thus restricting the flexibility of use for modelers. In this work, we present an adaptation of L-systems to the Python language, a popular and powerful open-license dynamic language. We show that the use of dynamic language properties makes it possible to enhance the development of plant growth models: (i) by keeping a simple syntax while allowing for high-level programming constructs, (ii) by making code execution easy and avoiding compilation overhead, (iii) by allowing a high-level of model reusability and the building of complex modular models, and (iv) by providing powerful solutions to integrate MTG data-structures (that are a common way to represent plants at several scales) into L-systems and thus enabling to use a wide spectrum of computer tools based on MTGs developed for plant architecture. We then illustrate the use of L-Py in real applications to build complex models or to teach plant modeling in the classroom.

An overview of natural hazard impacts to railways and urban transportation systems

NASA Astrophysics Data System (ADS)

Bíl, Michal; Nezval, Vojtěch; Bílová, Martina; Andrášik, Richard; Kubeček, Jan

2017-04-01

We present an overview and two case studies of natural hazard impacts on rail transportation systems in the Czech Republic. Flooding, landsliding, heavy snowfall, windstorms and glaze (black ice) are the most common natural processes which occur in this region. Whereas flooding and landsliding usually cause direct damage to the transportation infrastructure, other hazards predominantly cause indirect losses. Railway and urban tramline networks are almost fully dependent on electricity which is provided by a system of overhead lines (electric lines above the tracks). These lines are extremely susceptible to formation of glaze which blocks conduction of electric current. A December 2014 glaze event caused significant indirect losses in the largest Czech cities and railways due to the above-mentioned process. Details of this event will be provided during the presentation. Windstorms usually cause tree falls which can affect overhead lines and physically block railway tracks. Approximately 30 % of the Czech railway network is closer than 50 m from the nearest forest. This presents significant potential for transport interruption due to falling trees. Complicated legal relations among the owners of the plots of land along railways, the environment (full-grown trees and related habitat), and the railway administrator are behind many traffic interruptions due to falling trees. We have registered 2040 tree falls between 2012 and 2015 on the railway network. A model of the fallen tree hazard was created for the entire Czech railway network. Both above-mentioned case studies provide illustrative examples of the increased fragility of the modern transportation systems which fully rely on electricity. Natural processes with a low destructive power are thereby able to cause network wide service cut-offs.

KSC-2009-1584

NASA Image and Video Library

2009-02-13

CAPE CANAVERAL, Fla. – On Launch Pad 39B at NASA's Kennedy Space Center in Florida, the 100-foot lightning mast has been raised to vertical. It will be lifted and installed on top of the third and final new lightning tower being erected around the pad. The new lightning protection system is being built for the Constellation Program and Ares/Orion launches. Each of the towers is 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Tim Jacobs

KSC-2009-1562

NASA Image and Video Library

2009-02-12

CAPE CANAVERAL, Fla. – The faint sunrise sky over NASA's Kennedy Space Center casts the newly erected lightning towers on Launch Pad 39B in silhouette. They surround the fixed and rotating service structures at center that have served the Space Shuttle Program. The new lightning protection system is being built for the Constellation Program and Ares/Orion launches. Each of the towers is 500 feet tall with an additional 100-foot fiberglass mast atop supporting a wire catenary system. This improved lightning protection system allows for the taller height of the Ares I rocket compared to the space shuttle. Pad 39B will be the site of the first Ares vehicle launch, including the Ares I-X test flight that is targeted for July 2009. Photo credit: NASA/Jack Pfaller