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Sample records for achieve load balancing

  1. Dynamic load balancing of applications

    DOEpatents

    Wheat, S.R.

    1997-05-13

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers is disclosed. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated. 13 figs.

  2. Dynamic load balancing of applications

    DOEpatents

    Wheat, Stephen R.

    1997-01-01

    An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated.

  3. Load Balancing Scientific Applications

    SciTech Connect

    Pearce, Olga Tkachyshyn

    2014-12-01

    The largest supercomputers have millions of independent processors, and concurrency levels are rapidly increasing. For ideal efficiency, developers of the simulations that run on these machines must ensure that computational work is evenly balanced among processors. Assigning work evenly is challenging because many large modern parallel codes simulate behavior of physical systems that evolve over time, and their workloads change over time. Furthermore, the cost of imbalanced load increases with scale because most large-scale scientific simulations today use a Single Program Multiple Data (SPMD) parallel programming model, and an increasing number of processors will wait for the slowest one at the synchronization points. To address load imbalance, many large-scale parallel applications use dynamic load balance algorithms to redistribute work evenly. The research objective of this dissertation is to develop methods to decide when and how to load balance the application, and to balance it effectively and affordably. We measure and evaluate the computational load of the application, and develop strategies to decide when and how to correct the imbalance. Depending on the simulation, a fast, local load balance algorithm may be suitable, or a more sophisticated and expensive algorithm may be required. We developed a model for comparison of load balance algorithms for a specific state of the simulation that enables the selection of a balancing algorithm that will minimize overall runtime.

  4. Dynamic localized load balancing

    NASA Astrophysics Data System (ADS)

    Balandin, Sergey I.; Heiner, Andreas P.

    2003-08-01

    Traditionally dynamic load balancing is applied in resource-reserved connection-oriented networks with a large degree of managed control. Load balancing in connectionless networks is rather rudimentary and is either static or requires network-wide load information. This paper presents a fully automated, traffic driven dynamic load balancing mechanism that uses local load information. The proposed mechanism is easily deployed in a multi-vendor environment in which only a subset of routers supports the function. The Dynamic Localized Load Balancing (DLLB) mechanism distributes traffic based on two sets of weights. The first set is fixed and is inverse proportional to the path cost, typically the sum of reciprocal bandwidths along the path. The second weight reflects the utilization of the link to the first next hop along the path, and is therefore variable. The ratio of static weights defines the ideal load distribution, the ratio of variable weights the node-local load distribution estimate. By minimizing the difference between variable and fixed ratios the traffic distribution, with the available node-local knowledge, is optimal. The above mechanism significantly increases throughput and decreases delay from a network-wide perspective. Optionally the variable weight can include load information of nodes downstream to prevent congestion on those nodes. The latter function further improves network performance, and is easily implemented on top of the standard OSPF signaling. The mechanism does not require many node resources and can be implemented on existing router platforms.

  5. Multidimensional spectral load balancing

    DOEpatents

    Hendrickson, Bruce A.; Leland, Robert W.

    1996-12-24

    A method of and apparatus for graph partitioning involving the use of a plurality of eigenvectors of the Laplacian matrix of the graph of the problem for which load balancing is desired. The invention is particularly useful for optimizing parallel computer processing of a problem and for minimizing total pathway lengths of integrated circuits in the design stage.

  6. Multidimensional spectral load balancing

    SciTech Connect

    Hendrickson, B.; Leland, R.

    1993-01-01

    We describe an algorithm for the static load balancing of scientific computations that generalizes and improves upon spectral bisection. Through a novel use of multiple eigenvectors, our new spectral algorithm can divide a computation into 4 or 8 pieces at once. These multidimensional spectral partitioning algorithms generate balanced partitions that have lower communication overhead and are less expensive to compute than those produced by spectral bisection. In addition, they automatically work to minimize message contention on a hypercube or mesh architecture. These spectral partitions are further improved by a multidimensional generalization of the Kernighan-Lin graph partitioning algorithm. Results on several computational grids are given and compared with other popular methods.

  7. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  8. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  9. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  10. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  11. 14 CFR 23.421 - Balancing loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Balancing loads. 23.421 Section 23.421... Balancing Surfaces § 23.421 Balancing loads. (a) A horizontal surface balancing load is a load necessary to... balancing surfaces must be designed for the balancing loads occurring at any point on the limit...

  12. Control Allocation with Load Balancing

    NASA Technical Reports Server (NTRS)

    Bodson, Marc; Frost, Susan A.

    2009-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the actuator deflections. The paper discusses the alternative choice of the l(infinity) norm, or sup norm. Minimization of the control effort translates into the minimization of the maximum actuator deflection (min-max optimization). The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are also investigated through examples. In particular, the min-max criterion results in a type of load balancing, where the load is th desired command and the algorithm balances this load among various actuators. The solution using the l(infinity) norm also results in better robustness to failures and to lower sensitivity to nonlinearities in illustrative examples.

  13. Parallel Processing of Adaptive Meshes with Load Balancing

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Many scientific applications involve grids that lack a uniform underlying structure. These applications are often also dynamic in nature in that the grid structure significantly changes between successive phases of execution. In parallel computing environments, mesh adaptation of unstructured grids through selective refinement/coarsening has proven to be an effective approach. However, achieving load balance while minimizing interprocessor communication and redistribution costs is a difficult problem. Traditional dynamic load balancers are mostly inadequate because they lack a global view of system loads across processors. In this paper, we propose a novel and general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication topology, and compare its performance with a successful global load balancing environment, called PLUM, specifically created to handle adaptive unstructured applications. Our experimental results on an IBM SP2 demonstrate that the SBN-based load balancer achieves lower redistribution costs than that under PLUM by overlapping processing and data migration.

  14. Dynamic Load Balancing for Adaptive Meshes using Symmetric Broadcast Networks

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Saini, Subhash (Technical Monitor)

    1998-01-01

    Many scientific applications involve grids that lack a uniform underlying structure. These applications are often dynamic in the sense that the grid structure significantly changes between successive phases of execution. In parallel computing environments, mesh adaptation of grids through selective refinement/coarsening has proven to be an effective approach. However, achieving load balance while minimizing inter-processor communication and redistribution costs is a difficult problem. Traditional dynamic load balancers are mostly inadequate because they lack a global view across processors. In this paper, we compare a novel load balancer that utilizes symmetric broadcast networks (SBN) to a successful global load balancing environment (PLUM) created to handle adaptive unstructured applications. Our experimental results on the IBM SP2 demonstrate that performance of the proposed SBN load balancer is comparable to results achieved under PLUM.

  15. Dynamic Load Balancing of Parallel Monte Carlo Transport Calculations

    SciTech Connect

    O'Brien, M; Taylor, J; Procassini, R

    2004-12-22

    The performance of parallel Monte Carlo transport calculations which use both spatial and particle parallelism is increased by dynamically assigning processors to the most worked domains. Since the particle work load varies over the course of the simulation, this algorithm determines each cycle if dynamic load balancing would speed up the calculation. If load balancing is required, a small number of particle communications are initiated in order to achieve load balance. This method has decreased the parallel run time by more than a factor of three for certain criticality calculations.

  16. Balancing Loads Among Parallel Data Processors

    NASA Technical Reports Server (NTRS)

    Baffes, Paul Thomas

    1990-01-01

    Heuristic algorithm minimizes amount of memory used by multiprocessor system. Distributes load of many identical, short computations among multiple parallel digital data processors, each of which has its own (local) memory. Each processor operates on distinct and independent set of data in larger shared memory. As integral part of load-balancing scheme, total amount of space used in shared memory minimized. Possible applications include artificial neural networks or image processors for which "pipeline" and vector methods of load balancing inappropriate.

  17. Load-balancing algorithms for climate models

    NASA Astrophysics Data System (ADS)

    Foster, I. T.; Toonen, B. R.

    Implementations of climate models on scalable parallel computer systems can suffer from load imbalances due to temporal and spatial variations in the amount of computation required for physical parameterizations such as solar radiation and convective adjustment. We have developed specialized techniques for correcting such imbalances. These techniques are incorporated in a general-purpose, programmable load-balancing library that allows the mapping of computation to processors to be specified as a series of maps generated by a programmer-supplied load-balancing module. The communication required to move from one map to another is performed automatically by the library, without programmer intervention. In this paper, we describe the load-balancing problem and the techniques that we have developed to solve it. We also describe specific load-balancing algorithms that we have developed for PCCM2, a scalable parallel implementation of the community climate model, and present experimental results that demonstrate the effectiveness of these algorithms on parallel computers.

  18. BALANCING THE LOAD: A VORONOI BASED SCHEME FOR PARALLEL COMPUTATIONS

    SciTech Connect

    Steinberg, Elad; Yalinewich, Almog; Sari, Re'em; Duffell, Paul

    2015-01-01

    One of the key issues when running a simulation on multiple CPUs is maintaining a proper load balance throughout the run and minimizing communications between CPUs. We propose a novel method of utilizing a Voronoi diagram to achieve a nearly perfect load balance without the need of any global redistributions of data. As a show case, we implement our method in RICH, a two-dimensional moving mesh hydrodynamical code, but it can be extended trivially to other codes in two or three dimensions. Our tests show that this method is indeed efficient and can be used in a large variety of existing hydrodynamical codes.

  19. Internet traffic load balancing using dynamic hashing with flow volume

    NASA Astrophysics Data System (ADS)

    Jo, Ju-Yeon; Kim, Yoohwan; Chao, H. Jonathan; Merat, Francis L.

    2002-07-01

    Sending IP packets over multiple parallel links is in extensive use in today's Internet and its use is growing due to its scalability, reliability and cost-effectiveness. To maximize the efficiency of parallel links, load balancing is necessary among the links, but it may cause the problem of packet reordering. Since packet reordering impairs TCP performance, it is important to reduce the amount of reordering. Hashing offers a simple solution to keep the packet order by sending a flow over a unique link, but static hashing does not guarantee an even distribution of the traffic amount among the links, which could lead to packet loss under heavy load. Dynamic hashing offers some degree of load balancing but suffers from load fluctuations and excessive packet reordering. To overcome these shortcomings, we have enhanced the dynamic hashing algorithm to utilize the flow volume information in order to reassign only the appropriate flows. This new method, called dynamic hashing with flow volume (DHFV), eliminates unnecessary flow reassignments of small flows and achieves load balancing very quickly without load fluctuation by accurately predicting the amount of transferred load between the links. In this paper we provide the general framework of DHFV and address the challenges in implementing DHFV. We then introduce two algorithms of DHFV with different flow selection strategies and show their performances through simulation.

  20. Channel allocation and load balancing in totally mobile wireless networks

    NASA Astrophysics Data System (ADS)

    Cui, Wei; Bassiouni, Mostafa A.

    2000-07-01

    Previous studies on totally mobile wireless networks (TMWN) have been limited to non-hierarchical architectures. In this paper, we study a two-tier cellular architecture for TMWN. Under the constraints of equal power consumption, the two tier system achieves improvement over the one-tier system, especially at light and medium load levels. Performance tests have also shown that handoff prioritization can be achieved by restricting the use of the umbrella channels. Further improvement for the two-tier system was obtained by load balancing strategies with respect to the allocation of channels to the different cells.

  1. A single-stage optical load-balanced switch for data centers.

    PubMed

    Huang, Qirui; Yeo, Yong-Kee; Zhou, Luying

    2012-10-22

    Load balancing is an attractive technique to achieve maximum throughput and optimal resource utilization in large-scale switching systems. However current electronic load-balanced switches suffer from severe problems in implementation cost, power consumption and scaling. To overcome these problems, in this paper we propose a single-stage optical load-balanced switch architecture based on an arrayed waveguide grating router (AWGR) in conjunction with fast tunable lasers. By reuse of the fast tunable lasers, the switch achieves both functions of load balancing and switching through the AWGR. With this architecture, proof-of-concept experiments have been conducted to investigate the feasibility of the optical load-balanced switch and to examine its physical performance. Compared to three-stage load-balanced switches, the reported switch needs only half of optical devices such as tunable lasers and AWGRs, which can provide a cost-effective solution for future data centers.

  2. Static load balancing for CFD distributed simulations

    SciTech Connect

    Chronopoulos, A T; Grosu, D; Wissink, A; Benche, M

    2001-01-26

    The cost/performance ratio of networks of workstations has been constantly improving. This trend is expected to continue in the near future. The aggregate peak rate of such systems often matches or exceeds the peak rate offered by the fastest parallel computers. This has motivated research towards using a network of computers, interconnected via a fast network (cluster system) or a simple Local Area Network (LAN) (distributed system), for high performance concurrent computations. Some of the important research issues arise such as (1) Optimal problem partitioning and virtual interconnection topology mapping; (2) Optimal execution scheduling and load balancing. CFD codes have been efficiently implemented on homogeneous parallel systems in the past. In particular, the helicopter aerodynamics CFD code TURNS has been implemented with MPI on the IBM SP with parallel relaxation and Krylov iterative methods used in place of more traditional recursive algorithms to enhance performance. In this implementation the space domain is divided into equal subdomain which are mapped to the processors. We consider the implementation of TURNS on a LAN of heterogeneous workstations. In order to deal with the problem of load balancing due to the different processor speeds we propose a suboptimal algorithm of dividing the space domain into unequal subdomains and assign them to the different computers. The algorithm can apply to other CFD applications. We used our algorithm to schedule TURNS on a network of workstations and obtained significantly better results.

  3. Achieving the right balance with strategic planning.

    PubMed

    Martin, M

    1998-05-01

    Nurse executives must be involved with their organization's strategic management and marketing process, keep abreast of business trends and shifts, and at the same time find a good balance between nursing and business administration. An overview of the strategic planning models helps managers apply the process to health care, and in particular, nursing administration.

  4. The Balanced Reading Program: Helping All Students Achieve Success.

    ERIC Educational Resources Information Center

    Blair-Larsen, Susan M., Ed.; Williams, Kathryn A., Ed.

    This book explains the methodologies, techniques, strategies, and knowledge base necessary to achieve a balanced reading program. The book's contributors define the key elements in a balanced reading program and provide guidelines for implementing a balanced instructional program in the classroom. Following an introduction which addresses…

  5. Load balancing fictions, falsehoods and fallacies

    SciTech Connect

    HENDRICKSON,BRUCE A.

    2000-05-30

    Effective use of a parallel computer requires that a calculation be carefully divided among the processors. This load balancing problem appears in many guises and has been a fervent area of research for the past decade or more. Although great progress has been made, and useful software tools developed, a number of challenges remain. It is the conviction of the author that these challenges will be easier to address if programmers first come to terms with some significant shortcomings in their current perspectives. This paper tries to identify several areas in which the prevailing point of view is either mistaken or insufficient. The goal is to motivate new ideas and directions for this important field.

  6. Improving load balance with flexibly assignable tasks

    SciTech Connect

    Pinar, Ali; Hendrickson, Bruce

    2003-09-09

    In many applications of parallel computing, distribution ofthe data unambiguously implies distribution of work among processors. Butthere are exceptions where some tasks can be assigned to one of severalprocessors without altering the total volume of communication. In thispaper, we study the problem of exploiting this flexibility in assignmentof tasks to improve load balance. We first model the problem in terms ofnetwork flow and use combinatorial techniques for its solution. Ourparametric search algorithms use maximum flow algorithms for probing on acandidate optimal solution value. We describe two algorithms to solve theassignment problem with \\logW_T and vbar P vbar probe calls, w here W_Tand vbar P vbar, respectively, denote the total workload and number ofproce ssors. We also define augmenting paths and cuts for this problem,and show that anyalgorithm based on augmenting paths can be used to findan optimal solution for the task assignment problem. We then consideracontinuous version of the problem, and formulate it as a linearlyconstrained optimization problem, i.e., \\min\\|Ax\\|_\\infty,\\; {\\rms.t.}\\;Bx=d. To avoid solving an intractable \\infty-norm optimization problem,we show that in this case minimizing the 2-norm is sufficient to minimizethe \\infty-norm, which reduces the problem to the well-studiedlinearly-constrained least squares problem. The continuous version of theproblem has the advantage of being easily amenable to parallelization.Our experiments with molecular dynamics and overlapped domaindecomposition applications proved the effectiveness of our methods withsignificant improvements in load balance. We also discuss how ourtechniques can be enhanced for heterogeneous systems.

  7. Selective randomized load balancing and mesh networks with changing demands

    NASA Astrophysics Data System (ADS)

    Shepherd, F. B.; Winzer, P. J.

    2006-05-01

    We consider the problem of building cost-effective networks that are robust to dynamic changes in demand patterns. We compare several architectures using demand-oblivious routing strategies. Traditional approaches include single-hop architectures based on a (static or dynamic) circuit-switched core infrastructure and multihop (packet-switched) architectures based on point-to-point circuits in the core. To address demand uncertainty, we seek minimum cost networks that can carry the class of hose demand matrices. Apart from shortest-path routing, Valiant's randomized load balancing (RLB), and virtual private network (VPN) tree routing, we propose a third, highly attractive approach: selective randomized load balancing (SRLB). This is a blend of dual-hop hub routing and randomized load balancing that combines the advantages of both architectures in terms of network cost, delay, and delay jitter. In particular, we give empirical analyses for the cost (in terms of transport and switching equipment) for the discussed architectures, based on three representative carrier networks. Of these three networks, SRLB maintains the resilience properties of RLB while achieving significant cost reduction over all other architectures, including RLB and multihop Internet protocol/multiprotocol label switching (IP/MPLS) networks using VPN-tree routing.

  8. Achieving Integrated FEA Model and Loads Management

    NASA Astrophysics Data System (ADS)

    Lauzon, Dominick; Huf, Brian; Hagstrom, Dustin

    2012-07-01

    Recent developments in enterprise level simulation tools now enable CAE engineers and managers to keep up with today’s accelerating rate in the number and complexity of simulation models. All simulation related activities including Finite Element Models (FEM) variants and their respective results datasets can now be captured and managed. This provides valuable model pedigree from the source geometry referenced in the PDM system, spacecraft design and FEM configurations, external loads, simulation results and internal loads down to key results with the final critical design review and test correlation reports. The process presented in this paper demonstrates how simulation data capture and relationships can be achieved. Moreover, process management from conceptual design to spacecraft final proto-flight tests can now be achieved systematically and efficiently while performing and ensuring model quality, all the way from assembly level down to component level. MSC Software’s SimXpert and SimManager, two commercial off-the-shelf software codes, are used to highlight the benefits of this approach. In addition, an automation process that performs model validation per aerospace engineering best practice standards is also presented.

  9. Adaptive Load-Balancing Algorithms Using Symmetric Broadcast Networks

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Biswas, Rupak; Chancellor, Marisa K. (Technical Monitor)

    1997-01-01

    In a distributed-computing environment, it is important to ensure that the processor workloads are adequately balanced. Among numerous load-balancing algorithms, a unique approach due to Dam and Prasad defines a symmetric broadcast network (SBN) that provides a robust communication pattern among the processors in a topology-independent manner. In this paper, we propose and analyze three novel SBN-based load-balancing algorithms, and implement them on an SP2. A thorough experimental study with Poisson-distributed synthetic loads demonstrates that these algorithms are very effective in balancing system load while minimizing processor idle time. They also compare favorably with several other existing load-balancing techniques. Additional experiments performed with real data demonstrate that the SBN approach is effective in adaptive computational science and engineering applications where dynamic load balancing is extremely crucial.

  10. Dynamic load balance scheme for the DSMC algorithm

    SciTech Connect

    Li, Jin; Geng, Xiangren; Jiang, Dingwu; Chen, Jianqiang

    2014-12-09

    The direct simulation Monte Carlo (DSMC) algorithm, devised by Bird, has been used over a wide range of various rarified flow problems in the past 40 years. While the DSMC is suitable for the parallel implementation on powerful multi-processor architecture, it also introduces a large load imbalance across the processor array, even for small examples. The load imposed on a processor by a DSMC calculation is determined to a large extent by the total of simulator particles upon it. Since most flows are impulsively started with initial distribution of particles which is surely quite different from the steady state, the total of simulator particles will change dramatically. The load balance based upon an initial distribution of particles will break down as the steady state of flow is reached. The load imbalance and huge computational cost of DSMC has limited its application to rarefied or simple transitional flows. In this paper, by taking advantage of METIS, a software for partitioning unstructured graphs, and taking the total of simulator particles in each cell as a weight information, the repartitioning based upon the principle that each processor handles approximately the equal total of simulator particles has been achieved. The computation must pause several times to renew the total of simulator particles in each processor and repartition the whole domain again. Thus the load balance across the processors array holds in the duration of computation. The parallel efficiency can be improved effectively. The benchmark solution of a cylinder submerged in hypersonic flow has been simulated numerically. Besides, hypersonic flow past around a complex wing-body configuration has also been simulated. The results have displayed that, for both of cases, the computational time can be reduced by about 50%.

  11. Experience with automatic, dynamic load balancing and adaptive finite element computation

    SciTech Connect

    Wheat, S.R.; Devine, K.D.; Maccabe, A.B.

    1993-10-01

    Distributed memory, Massively Parallel (MP), MIMD technology has enabled the development of applications requiring computational resources previously unobtainable. Structural mechanics and fluid dynamics applications, for example, are often solved by finite element methods (FEMs) requiring, millions of degrees of freedom to accurately simulate physical phenomenon. Adaptive methods, which automatically refine or coarsen meshes and vary the order of accuracy of the numerical solution, offer greater robustness and computational efficiency than traditional FEMs by reducing the amount of computation required away from physical structures such as shock waves and boundary layers. On MP computers, FEMs frequently result in distributed processor load imbalances. To overcome load imbalance, many MP FEMs use static load balancing as a preprocessor to the finite element calculation. Adaptive methods complicate the load imbalance problem since the work per element is not uniform across the solution domain and changes as the computation proceeds. Therefore, dynamic load balancing is required to maintain global load balance. We describe a dynamic, fine-grained, element-based data migration system that maintains global load balance and is effective in the presence of changing work loads. Global load balance is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method utilizes an automatic element management system library to which a programmer integrates the application`s computational description. The library`s flexibility supports a large class of finite element and finite difference based applications.

  12. Load Balancing in Structured P2P Networks

    NASA Astrophysics Data System (ADS)

    Zhu, Yingwu

    In this chapter we start by addressing the importance and necessity of load balancing in structured P2P networks, due to three main reasons. First, structured P2P networks assume uniform peer capacities while peer capacities are heterogeneous in deployed P2P networks. Second, resorting to pseudo-uniformity of the hash function used to generate node IDs and data item keys leads to imbalanced overlay address space and item distribution. Lastly, placement of data items cannot be randomized in some applications (e.g., range searching). We then present an overview of load aggregation and dissemination techniques that are required by many load balancing algorithms. Two techniques are discussed including tree structure-based approach and gossip-based approach. They make different tradeoffs between estimate/aggregate accuracy and failure resilience. To address the issue of load imbalance, three main solutions are described: virtual server-based approach, power of two choices, and address-space and item balancing. While different in their designs, they all aim to improve balance on the address space and data item distribution. As a case study, the chapter discusses a virtual server-based load balancing algorithm that strives to ensure fair load distribution among nodes and minimize load balancing cost in bandwidth. Finally, the chapter concludes with future research and a summary.

  13. Fuzzy Pool Balance: An algorithm to achieve a two dimensional balance in distribute storage systems

    NASA Astrophysics Data System (ADS)

    Wu, Wenjing; Chen, Gang

    2014-06-01

    The limitation of scheduling modules and the gradual addition of disk pools in distributed storage systems often result in imbalances among their disk pools in terms of both disk usage and file count. This can cause various problems to the storage system such as single point of failure, low system throughput and imbalanced resource utilization and system loads. An algorithm named Fuzzy Pool Balance (FPB) is proposed here to solve this problem. The input of FPB is the current file distribution among disk pools and the output is a file migration plan indicating what files are to be migrated to which pools. FPB uses an array to classify the files by their sizes. The file classification array is dynamically calculated with a defined threshold named Tmax that defines the allowed pool disk usage deviations. File classification is the basis of file migration. FPB also defines the Immigration Pool (IP) and Emigration Pool (EP) according to the pool disk usage and File Quantity Ratio (FQR) that indicates the percentage of each category of files in each disk pool, so files with higher FQR in an EP will be migrated to IP(s) with a lower FQR of this file category. To verify this algorithm, we implemented FPB on an ATLAS Tier2 dCache production system. The results show that FPB can achieve a very good balance in both free space and file counts, and adjusting the threshold value Tmax and the correction factor to the average FQR can achieve a tradeoff between free space and file count.

  14. Adaptive Load-Balancing Algorithms using Symmetric Broadcast Networks

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    In a distributed computing environment, it is important to ensure that the processor workloads are adequately balanced, Among numerous load-balancing algorithms, a unique approach due to Das and Prasad defines a symmetric broadcast network (SBN) that provides a robust communication pattern among the processors in a topology-independent manner. In this paper, we propose and analyze three efficient SBN-based dynamic load-balancing algorithms, and implement them on an SGI Origin2000. A thorough experimental study with Poisson distributed synthetic loads demonstrates that our algorithms are effective in balancing system load. By optimizing completion time and idle time, the proposed algorithms are shown to compare favorably with several existing approaches.

  15. Design of dynamic load-balancing tools for parallel applications

    SciTech Connect

    Devine, K.D.; Hendrickson, B.A.; Boman, E.G.; St. John, M.; Vaughan, C.T.

    2000-01-03

    The design of general-purpose dynamic load-balancing tools for parallel applications is more challenging than the design of static partitioning tools. Both algorithmic and software engineering issues arise. The authors have addressed many of these issues in the design of the Zoltan dynamic load-balancing library. Zoltan has an object-oriented interface that makes it easy to use and provides separation between the application and the load-balancing algorithms. It contains a suite of dynamic load-balancing algorithms, including both geometric and graph-based algorithms. Its design makes it valuable both as a partitioning tool for a variety of applications and as a research test-bed for new algorithmic development. In this paper, the authors describe Zoltan's design and demonstrate its use in an unstructured-mesh finite element application.

  16. Detection of Unexpected High Correlations between Balance Calibration Loads and Load Residuals

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Volden, T.

    2014-01-01

    An algorithm was developed for the assessment of strain-gage balance calibration data that makes it possible to systematically investigate potential sources of unexpected high correlations between calibration load residuals and applied calibration loads. The algorithm investigates correlations on a load series by load series basis. The linear correlation coefficient is used to quantify the correlations. It is computed for all possible pairs of calibration load residuals and applied calibration loads that can be constructed for the given balance calibration data set. An unexpected high correlation between a load residual and a load is detected if three conditions are met: (i) the absolute value of the correlation coefficient of a residual/load pair exceeds 0.95; (ii) the maximum of the absolute values of the residuals of a load series exceeds 0.25 % of the load capacity; (iii) the load component of the load series is intentionally applied. Data from a baseline calibration of a six-component force balance is used to illustrate the application of the detection algorithm to a real-world data set. This analysis also showed that the detection algorithm can identify load alignment errors as long as repeat load series are contained in the balance calibration data set that do not suffer from load alignment problems.

  17. Performance Analysis and Portability of the PLUM Load Balancing System

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

    1998-01-01

    The ability to dynamically adapt an unstructured mesh is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive numerical computations in a message-passing environment. PLUM requires that all data be globally redistributed after each mesh adaption to achieve load balance. We present an algorithm for minimizing this remapping overhead by guaranteeing an optimal processor reassignment. We also show that the data redistribution cost can be significantly reduced by applying our heuristic processor reassignment algorithm to the default mapping of the parallel partitioner. Portability is examined by comparing performance on a SP2, an Origin2000, and a T3E. Results show that PLUM can be successfully ported to different platforms without any code modifications.

  18. Load Balancing Using Time Series Analysis for Soft Real Time Systems with Statistically Periodic Loads

    NASA Technical Reports Server (NTRS)

    Hailperin, Max

    1993-01-01

    This thesis provides design and analysis of techniques for global load balancing on ensemble architectures running soft-real-time object-oriented applications with statistically periodic loads. It focuses on estimating the instantaneous average load over all the processing elements. The major contribution is the use of explicit stochastic process models for both the loading and the averaging itself. These models are exploited via statistical time-series analysis and Bayesian inference to provide improved average load estimates, and thus to facilitate global load balancing. This thesis explains the distributed algorithms used and provides some optimality results. It also describes the algorithms' implementation and gives performance results from simulation. These results show that our techniques allow more accurate estimation of the global system load ing, resulting in fewer object migration than local methods. Our method is shown to provide superior performance, relative not only to static load-balancing schemes but also to many adaptive methods.

  19. PLUM: Parallel Load Balancing for Adaptive Unstructured Meshes

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak; Saini, Subhash (Technical Monitor)

    1998-01-01

    Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. We present a novel method called PLUM to dynamically balance the processor workloads with a global view. This paper presents the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. A data redistribution model is also presented that predicts the remapping cost on the SP2. This model is required to determine whether the gain from a balanced workload distribution offsets the cost of data movement. Results presented in this paper demonstrate that PLUM is an effective dynamic load balancing strategy which remains viable on a large number of processors.

  20. An Evaluation of the HVAC Load Potential for Providing Load Balancing Service

    SciTech Connect

    Lu, Ning

    2012-09-30

    This paper investigates the potential of providing aggregated intra-hour load balancing services using heating, ventilating, and air-conditioning (HVAC) systems. A direct-load control algorithm is presented. A temperature-priority-list method is used to dispatch the HVAC loads optimally to maintain consumer-desired indoor temperatures and load diversity. Realistic intra-hour load balancing signals were used to evaluate the operational characteristics of the HVAC load under different outdoor temperature profiles and different indoor temperature settings. The number of HVAC units needed is also investigated. Modeling results suggest that the number of HVACs needed to provide a {+-}1-MW load balancing service 24 hours a day varies significantly with baseline settings, high and low temperature settings, and the outdoor temperatures. The results demonstrate that the intra-hour load balancing service provided by HVAC loads meet the performance requirements and can become a major source of revenue for load-serving entities where the smart grid infrastructure enables direct load control over the HAVC loads.

  1. Load Balancing Unstructured Adaptive Grids for CFD Problems

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Oliker, Leonid

    1996-01-01

    Mesh adaption is a powerful tool for efficient unstructured-grid computations but causes load imbalance among processors on a parallel machine. A dynamic load balancing method is presented that balances the workload across all processors with a global view. After each parallel tetrahedral mesh adaption, the method first determines if the new mesh is sufficiently unbalanced to warrant a repartitioning. If so, the adapted mesh is repartitioned, with new partitions assigned to processors so that the redistribution cost is minimized. The new partitions are accepted only if the remapping cost is compensated by the improved load balance. Results indicate that this strategy is effective for large-scale scientific computations on distributed-memory multiprocessors.

  2. Load Balancing Using Time Series Analysis for Soft Real Time Systems with Statistically Periodic Loads

    NASA Technical Reports Server (NTRS)

    Hailperin, M.

    1993-01-01

    This thesis provides design and analysis of techniques for global load balancing on ensemble architectures running soft-real-time object-oriented applications with statistically periodic loads. It focuses on estimating the instantaneous average load over all the processing elements. The major contribution is the use of explicit stochastic process models for both the loading and the averaging itself. These models are exploited via statistical time-series analysis and Bayesian inference to provide improved average load estimates, and thus to facilitate global load balancing. This thesis explains the distributed algorithms used and provides some optimality results. It also describes the algorithms' implementation and gives performance results from simulation. These results show that the authors' techniques allow more accurate estimation of the global system loading, resulting in fewer object migrations than local methods. The authors' method is shown to provide superior performance, relative not only to static load-balancing schemes but also to many adaptive load-balancing methods. Results from a preliminary analysis of another system and from simulation with a synthetic load provide some evidence of more general applicability.

  3. A novel load balancing method for hierarchical federation simulation system

    NASA Astrophysics Data System (ADS)

    Bin, Xiao; Xiao, Tian-yuan

    2013-07-01

    In contrast with single HLA federation framework, hierarchical federation framework can improve the performance of large-scale simulation system in a certain degree by distributing load on several RTI. However, in hierarchical federation framework, RTI is still the center of message exchange of federation, and it is still the bottleneck of performance of federation, the data explosion in a large-scale HLA federation may cause overload on RTI, It may suffer HLA federation performance reduction or even fatal error. Towards this problem, this paper proposes a load balancing method for hierarchical federation simulation system based on queuing theory, which is comprised of three main module: queue length predicting, load controlling policy, and controller. The method promotes the usage of resources of federate nodes, and improves the performance of HLA simulation system with balancing load on RTIG and federates. Finally, the experiment results are presented to demonstrate the efficient control of the method.

  4. Achieving excellence in veterans healthcare--a balanced scorecard approach.

    PubMed

    Biro, Lawrence A; Moreland, Michael E; Cowgill, David E

    2003-01-01

    This article provides healthcare administrators and managers with a framework and model for developing a balanced scorecard and demonstrates the remarkable success of this process, which brings focus to leadership decisions about the allocation of resources. This scorecard was developed as a top management tool designed to structure multiple priorities of a large, complex, integrated healthcare system and to establish benchmarks to measure success in achieving targets for performance in identified areas. Significant benefits and positive results were derived from the implementation of the balanced scorecard, based upon benchmarks considered to be critical success factors. The network's chief executive officer and top leadership team set and articulated the network's primary operating principles: quality and efficiency in the provision of comprehensive healthcare and support services. Under the weighted benchmarks of the balanced scorecard, the facilities in the network were mandated to adhere to one non-negotiable tenet: providing care that is second to none. The balanced scorecard approach to leadership continuously ensures that this is the primary goal and focal point for all activity within the network. To that end, systems are always in place to ensure that the network is fully successful on all performance measures relating to quality.

  5. Dynamic Load Balancing Strategies for Parallel Reacting Flow Simulations

    NASA Astrophysics Data System (ADS)

    Pisciuneri, Patrick; Meneses, Esteban; Givi, Peyman

    2014-11-01

    Load balancing in parallel computing aims at distributing the work as evenly as possible among the processors. This is a critical issue in the performance of parallel, time accurate, flow simulators. The constraint of time accuracy requires that all processes must be finished with their calculation for a given time step before any process can begin calculation of the next time step. Thus, an irregularly balanced compute load will result in idle time for many processes for each iteration and thus increased walltimes for calculations. Two existing, dynamic load balancing approaches are applied to the simplified case of a partially stirred reactor for methane combustion. The first is Zoltan, a parallel partitioning, load balancing, and data management library developed at the Sandia National Laboratories. The second is Charm++, which is its own machine independent parallel programming system developed at the University of Illinois at Urbana-Champaign. The performance of these two approaches is compared, and the prospects for their application to full 3D, reacting flow solvers is assessed.

  6. Multithreaded Model for Dynamic Load Balancing Parallel Adaptive PDE Computations

    NASA Technical Reports Server (NTRS)

    Chrisochoides, Nikos

    1995-01-01

    We present a multithreaded model for the dynamic load-balancing of numerical, adaptive computations required for the solution of Partial Differential Equations (PDE's) on multiprocessors. Multithreading is used as a means of exploring concurrency in the processor level in order to tolerate synchronization costs inherent to traditional (non-threaded) parallel adaptive PDE solvers. Our preliminary analysis for parallel, adaptive PDE solvers indicates that multithreading can be used an a mechanism to mask overheads required for the dynamic balancing of processor workloads with computations required for the actual numerical solution of the PDE's. Also, multithreading can simplify the implementation of dynamic load-balancing algorithms, a task that is very difficult for traditional data parallel adaptive PDE computations. Unfortunately, multithreading does not always simplify program complexity, often makes code re-usability not an easy task, and increases software complexity.

  7. Performance tradeoffs in static and dynamic load balancing strategies

    NASA Technical Reports Server (NTRS)

    Iqbal, M. A.; Saltz, J. H.; Bokhart, S. H.

    1986-01-01

    The problem of uniformly distributing the load of a parallel program over a multiprocessor system was considered. A program was analyzed whose structure permits the computation of the optimal static solution. Then four strategies for load balancing were described and their performance compared. The strategies are: (1) the optimal static assignment algorithm which is guaranteed to yield the best static solution, (2) the static binary dissection method which is very fast but sub-optimal, (3) the greedy algorithm, a static fully polynomial time approximation scheme, which estimates the optimal solution to arbitrary accuracy, and (4) the predictive dynamic load balancing heuristic which uses information on the precedence relationships within the program and outperforms any of the static methods. It is also shown that the overhead incurred by the dynamic heuristic is reduced considerably if it is started off with a static assignment provided by either of the other three strategies.

  8. A comparative analysis of static and dynamic load balancing strategies

    NASA Technical Reports Server (NTRS)

    Iqbal, M. Ashraf; Bokhari, Shahid H.; Saltz, Joel H.

    1986-01-01

    The problem of uniformly distributing the load of a parallel program over a multiprocessor system was considered. A program was analyzed whose structure permits the computation of the optimal static solution. Then four strategies for load balancing were described and their performance compared. The strategies are: (1) the optimal static assignment algorithm which is guaranteed to yield the best static solution, (2) the static binary dissection method which is very fast but suboptimal, (3) the greedy algorithm, a static fully polynomial time approximation scheme, which estimates the optimal solution to arbitrary accuracy, and (4) the predictive dynamic load balancing heuristic which uses information on the precedence relationships within the program and outperforms any of the static methods. It is also shown that the overhead incurred by the dynamic heuristic is reduced considerably if it is started off with a static assignment provided by either of the three strategies.

  9. Parallel tetrahedral mesh adaptation with dynamic load balancing

    SciTech Connect

    Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

    2000-06-28

    The ability to dynamically adapt an unstructured grid is a powerful tool for efficiently solving computational problems with evolving physical features. In this paper, we report on our experience parallelizing an edge-based adaptation scheme, called 3D-TAG, using message passing. Results show excellent speedup when a realistic helicopter rotor mesh is randomly refined. However, performance deteriorates when the mesh is refined using a solution-based error indicator since mesh adaptation for practical problems occurs in a localized region, creating a severe load imbalance. To address this problem, we have developed PLUM, a global dynamic load balancing framework for adaptive numerical computations. Even though PLUM primarily balances processor workloads for the solution phase, it reduces the load imbalance problem within mesh adaptation by repartitioning the mesh after targeting edges for refinement but before the actual subdivision. This dramatically improves the performance of parallel 3D-TAG since refinement occurs in a more load balanced fashion. We also present optimal and heuristic algorithms that, when applied to the default mapping of a parallel repartitioner, significantly reduce the data redistribution overhead. Finally, portability is examined by comparing performance on three state-of-the-art parallel machines.

  10. Parallel Tetrahedral Mesh Adaptation with Dynamic Load Balancing

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

    1999-01-01

    The ability to dynamically adapt an unstructured grid is a powerful tool for efficiently solving computational problems with evolving physical features. In this paper, we report on our experience parallelizing an edge-based adaptation scheme, called 3D_TAG. using message passing. Results show excellent speedup when a realistic helicopter rotor mesh is randomly refined. However. performance deteriorates when the mesh is refined using a solution-based error indicator since mesh adaptation for practical problems occurs in a localized region., creating a severe load imbalance. To address this problem, we have developed PLUM, a global dynamic load balancing framework for adaptive numerical computations. Even though PLUM primarily balances processor workloads for the solution phase, it reduces the load imbalance problem within mesh adaptation by repartitioning the mesh after targeting edges for refinement but before the actual subdivision. This dramatically improves the performance of parallel 3D_TAG since refinement occurs in a more load balanced fashion. We also present optimal and heuristic algorithms that, when applied to the default mapping of a parallel repartitioner, significantly reduce the data redistribution overhead. Finally, portability is examined by comparing performance on three state-of-the-art parallel machines.

  11. Efficient Load Balancing and Data Remapping for Adaptive Grid Calculations

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak

    1997-01-01

    Mesh adaption is a powerful tool for efficient unstructured- grid computations but causes load imbalance among processors on a parallel machine. We present a novel method to dynamically balance the processor workloads with a global view. This paper presents, for the first time, the implementation and integration of all major components within our dynamic load balancing strategy for adaptive grid calculations. Mesh adaption, repartitioning, processor assignment, and remapping are critical components of the framework that must be accomplished rapidly and efficiently so as not to cause a significant overhead to the numerical simulation. Previous results indicated that mesh repartitioning and data remapping are potential bottlenecks for performing large-scale scientific calculations. We resolve these issues and demonstrate that our framework remains viable on a large number of processors.

  12. Load Balancing Strategies for Multi-Block Overset Grid Applications

    NASA Technical Reports Server (NTRS)

    Djomehri, M. Jahed; Biswas, Rupak; Lopez-Benitez, Noe; Biegel, Bryan (Technical Monitor)

    2002-01-01

    The multi-block overset grid method is a powerful technique for high-fidelity computational fluid dynamics (CFD) simulations about complex aerospace configurations. The solution process uses a grid system that discretizes the problem domain by using separately generated but overlapping structured grids that periodically update and exchange boundary information through interpolation. For efficient high performance computations of large-scale realistic applications using this methodology, the individual grids must be properly partitioned among the parallel processors. Overall performance, therefore, largely depends on the quality of load balancing. In this paper, we present three different load balancing strategies far overset grids and analyze their effects on the parallel efficiency of a Navier-Stokes CFD application running on an SGI Origin2000 machine.

  13. Scalable load-balance measurement for SPMD codes

    SciTech Connect

    Gamblin, T; de Supinski, B R; Schulz, M; Fowler, R; Reed, D

    2008-08-05

    Good load balance is crucial on very large parallel systems, but the most sophisticated algorithms introduce dynamic imbalances through adaptation in domain decomposition or use of adaptive solvers. To observe and diagnose imbalance, developers need system-wide, temporally-ordered measurements from full-scale runs. This potentially requires data collection from multiple code regions on all processors over the entire execution. Doing this instrumentation naively can, in combination with the application itself, exceed available I/O bandwidth and storage capacity, and can induce severe behavioral perturbations. We present and evaluate a novel technique for scalable, low-error load balance measurement. This uses a parallel wavelet transform and other parallel encoding methods. We show that our technique collects and reconstructs system-wide measurements with low error. Compression time scales sublinearly with system size and data volume is several orders of magnitude smaller than the raw data. The overhead is low enough for online use in a production environment.

  14. Monitoring dynamic loads on wind tunnel force balances

    NASA Technical Reports Server (NTRS)

    Ferris, Alice T.; White, William C.

    1989-01-01

    Two devices have been developed at NASA Langley to monitor the dynamic loads incurred during wind-tunnel testing. The Balance Dynamic Display Unit (BDDU), displays and monitors the combined static and dynamic forces and moments in the orthogonal axes. The Balance Critical Point Analyzer scales and sums each normalized signal from the BDDU to obtain combined dynamic and static signals that represent the dynamic loads at predefined high-stress points. The display of each instrument is a multiplex of six analog signals in a way that each channel is displayed sequentially as one-sixth of the horizontal axis on a single oscilloscope trace. Thus this display format permits the operator to quickly and easily monitor the combined static and dynamic level of up to six channels at the same time.

  15. 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.

  16. Dual strain gage balance system for measuring light loads

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W. (Inventor)

    1991-01-01

    A dual strain gage balance system for measuring normal and axial forces and pitching moment of a metric airfoil model imparted by aerodynamic loads applied to the airfoil model during wind tunnel testing includes a pair of non-metric panels being rigidly connected to and extending towards each other from opposite sides of the wind tunnel, and a pair of strain gage balances, each connected to one of the non-metric panels and to one of the opposite ends of the metric airfoil model for mounting the metric airfoil model between the pair of non-metric panels. Each strain gage balance has a first measuring section for mounting a first strain gage bridge for measuring normal force and pitching moment and a second measuring section for mounting a second strain gage bridge for measuring axial force.

  17. Simulation model of load balancing in distributed computing systems

    NASA Astrophysics Data System (ADS)

    Botygin, I. A.; Popov, V. N.; Frolov, S. G.

    2017-02-01

    The availability of high-performance computing, high speed data transfer over the network and widespread of software for the design and pre-production in mechanical engineering have led to the fact that at the present time the large industrial enterprises and small engineering companies implement complex computer systems for efficient solutions of production and management tasks. Such computer systems are generally built on the basis of distributed heterogeneous computer systems. The analytical problems solved by such systems are the key models of research, but the system-wide problems of efficient distribution (balancing) of the computational load and accommodation input, intermediate and output databases are no less important. The main tasks of this balancing system are load and condition monitoring of compute nodes, and the selection of a node for transition of the user’s request in accordance with a predetermined algorithm. The load balancing is one of the most used methods of increasing productivity of distributed computing systems through the optimal allocation of tasks between the computer system nodes. Therefore, the development of methods and algorithms for computing optimal scheduling in a distributed system, dynamically changing its infrastructure, is an important task.

  18. Static and dynamic load-balancing strategies for parallel reservoir simulation

    SciTech Connect

    Anguille, L.; Killough, J.E.; Li, T.M.C.; Toepfer, J.L.

    1995-12-31

    Accurate simulation of the complex phenomena that occur in flow in porous media can tax even the most powerful serial computers. Emergence of new parallel computer architectures as a future efficient tool in reservoir simulation may overcome this difficulty. Unfortunately, major problems remain to be solved before using parallel computers commercially: production serial programs must be rewritten to be efficient in parallel environments and load balancing methods must be explored to evenly distribute the workload on each processor during the simulation. This study implements both a static load-balancing algorithm and a receiver-initiated dynamic load-sharing algorithm to achieve high parallel efficiencies on both the IBM SP2 and Intel IPSC/860 parallel computers. Significant speedup improvement was recorded for both methods. Further optimization of these algorithms yielded a technique with efficiencies as high as 90% and 70% on 8 and 32 nodes, respectively. The increased performance was the result of the minimization of message-passing overhead.

  19. Transport aircraft loading and balancing system: Using a CLIPS expert system for military aircraft load planning

    NASA Technical Reports Server (NTRS)

    Richardson, J.; Labbe, M.; Belala, Y.; Leduc, Vincent

    1994-01-01

    The requirement for improving aircraft utilization and responsiveness in airlift operations has been recognized for quite some time by the Canadian Forces. To date, the utilization of scarce airlift resources has been planned mainly through the employment of manpower-intensive manual methods in combination with the expertise of highly qualified personnel. In this paper, we address the problem of facilitating the load planning process for military aircraft cargo planes through the development of a computer-based system. We introduce TALBAS (Transport Aircraft Loading and BAlancing System), a knowledge-based system designed to assist personnel involved in preparing valid load plans for the C130 Hercules aircraft. The main features of this system which are accessible through a convivial graphical user interface, consists of the automatic generation of valid cargo arrangements given a list of items to be transported, the user-definition of load plans and the automatic validation of such load plans.

  20. Estimating nutrient loadings using chemical mass balance approach.

    PubMed

    Jain, C K; Singhal, D C; Sharma, M K

    2007-11-01

    The river Hindon is one of the important tributaries of river Yamuna in western Uttar Pradesh (India) and carries pollution loads from various municipal and industrial units and surrounding agricultural areas. The main sources of pollution in the river include municipal wastes from Saharanpur, Muzaffarnagar and Ghaziabad urban areas and industrial effluents of sugar, pulp and paper, distilleries and other miscellaneous industries through tributaries as well as direct inputs. In this paper, chemical mass balance approach has been used to assess the contribution from non-point sources of pollution to the river. The river system has been divided into three stretches depending on the land use pattern. The contribution of point sources in the upper and lower stretches are 95 and 81% respectively of the total flow of the river while there is no point source input in the middle stretch. Mass balance calculations indicate that contribution of nitrate and phosphate from non-point sources amounts to 15.5 and 6.9% in the upper stretch and 13.1 and 16.6% in the lower stretch respectively. Observed differences in the load along the river may be attributed to uncharacterized sources of pollution due to agricultural activities, remobilization from or entrainment of contaminated bottom sediments, ground water contribution or a combination of these sources.

  1. Population-based learning of load balancing policies for a distributed computer system

    NASA Technical Reports Server (NTRS)

    Mehra, Pankaj; Wah, Benjamin W.

    1993-01-01

    Effective load-balancing policies use dynamic resource information to schedule tasks in a distributed computer system. We present a novel method for automatically learning such policies. At each site in our system, we use a comparator neural network to predict the relative speedup of an incoming task using only the resource-utilization patterns obtained prior to the task's arrival. Outputs of these comparator networks are broadcast periodically over the distributed system, and the resource schedulers at each site use these values to determine the best site for executing an incoming task. The delays incurred in propagating workload information and tasks from one site to another, as well as the dynamic and unpredictable nature of workloads in multiprogrammed multiprocessors, may cause the workload pattern at the time of execution to differ from patterns prevailing at the times of load-index computation and decision making. Our load-balancing policy accommodates this uncertainty by using certain tunable parameters. We present a population-based machine-learning algorithm that adjusts these parameters in order to achieve high average speedups with respect to local execution. Our results show that our load-balancing policy, when combined with the comparator neural network for workload characterization, is effective in exploiting idle resources in a distributed computer system.

  2. Work Stealing and Persistence-based Load Balancers for Iterative Overdecomposed Applications

    SciTech Connect

    Lifflander, Jonathan; Krishnamoorthy, Sriram; Kale, Laxmikant

    2012-06-18

    Applications often involve iterative execution of identical or slowly evolving calculations. Such applications require good initial load balance coupled with efficient periodic rebalancing. In this paper, we consider the design and evaluation of two distinct approaches to addressing this challenge: persistence-based load balancing and work stealing. The work to be performed is overdecomposed into tasks, enabling automatic rebalancing by the middleware. We present a hierarchical persistence-based rebalancing algorithm that performs localized incremental rebalancing. We also present an active-message-based retentive work stealing algorithm optimized for iterative applications on distributed memory machines. These are shown to incur low overheads and achieve over 90% efficiency on 76,800 cores.

  3. A Baseline Load Schedule for the Manual Calibration of a Force Balance

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Gisler, R.

    2013-01-01

    A baseline load schedule for the manual calibration of a force balance was developed that takes current capabilities at the NASA Ames Balance Calibration Laboratory into account. The load schedule consists of 18 load series with a total of 194 data points. It was designed to satisfy six requirements: (i) positive and negative loadings should be applied for each load component; (ii) at least three loadings should be applied between 0 % and 100 % load capacity; (iii) normal and side force loadings should be applied at the forward gage location, the aft gage location, and the balance moment center; (iv) the balance should be used in UP and DOWN orientation to get axial force loadings; (v) the constant normal and side force approaches should be used to get the rolling moment loadings; (vi) rolling moment loadings should be obtained for 0, 90, 180, and 270 degrees balance orientation. Three different approaches are also reviewed that may be used to independently estimate the natural zeros of the balance. These three approaches provide gage output differences that may be used to estimate the weight of both the metric and non-metric part of the balance. Manual calibration data of NASA s MK29A balance and machine calibration data of NASA s MC60D balance are used to illustrate and evaluate different aspects of the proposed baseline load schedule design.

  4. A Baseline Load Schedule for the Manual Calibration of a Force Balance

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Gisler, R.

    2013-01-01

    A baseline load schedule for the manual calibration of a force balance is defined that takes current capabilities at the NASA Ames Balance Calibration Laboratory into account. The chosen load schedule consists of 18 load series with a total of 194 data points. It was designed to satisfy six requirements: (i) positive and negative loadings should be applied for each load component; (ii) at least three loadings should be applied between 0 % and 100 % load capacity; (iii) normal and side force loadings should be applied at the forward gage location, aft gage location, and the balance moment center; (iv) the balance should be used in "up" and "down" orientation to get positive and negative axial force loadings; (v) the constant normal and side force approaches should be used to get the rolling moment loadings; (vi) rolling moment loadings should be obtained for 0, 90, 180, and 270 degrees balance orientation. In addition, three different approaches are discussed in the paper that may be used to independently estimate the natural zeros, i.e., the gage outputs of the absolute load datum of the balance. These three approaches provide gage output differences that can be used to estimate the weight of both the metric and non-metric part of the balance. Data from the calibration of a six-component force balance will be used in the final manuscript of the paper to illustrate characteristics of the proposed baseline load schedule.

  5. BALANCE

    DOEpatents

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  6. PLUM: Parallel Load Balancing for Unstructured Adaptive Meshes. Degree awarded by Colorado Univ.

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid

    1998-01-01

    Dynamic mesh adaption on unstructured grids is a powerful tool for computing large-scale problems that require grid modifications to efficiently resolve solution features. By locally refining and coarsening the mesh to capture physical phenomena of interest, such procedures make standard computational methods more cost effective. Unfortunately, an efficient parallel implementation of these adaptive methods is rather difficult to achieve, primarily due to the load imbalance created by the dynamically-changing nonuniform grid. This requires significant communication at runtime, leading to idle processors and adversely affecting the total execution time. Nonetheless, it is generally thought that unstructured adaptive- grid techniques will constitute a significant fraction of future high-performance supercomputing. Various dynamic load balancing methods have been reported to date; however, most of them either lack a global view of loads across processors or do not apply their techniques to realistic large-scale applications.

  7. Achieving Life Balance: Myths, Realities, and Developmental Perspectives. Information Series.

    ERIC Educational Resources Information Center

    Niles, Spencer G.; Herr, Edwin L.; Hartung, Paul J.

    The evolving role of work in society and the factors driving emerging trends in work were examined to assist career development practitioners in helping individuals deal with life-role balance. Donald Super's life-space theory was presented as a framework for adult career development and used as a backdrop for discussing how adults can crystallize…

  8. Combined Load Diagram for a Wind Tunnel Strain-Gage Balance

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2010-01-01

    Combined Load Diagrams for Direct-Read, Force, and Moment Balances are discussed in great detail in the paper. The diagrams, if compared with a corresponding combined load plot of a balance calibration data set, may be used to visualize and interpret basic relationships between the applied balance calibration loads and the load components at the forward and aft gage of a strain-age balance. Lines of constant total force and moment are identified in the diagrams. In addition, the lines of pure force and pure moment are highlighted. Finally, lines of constant moment arm are depicted. It is also demonstrated that each quadrant of a Combined Load Diagram has specific regions where the applied total calibration force is at, between, or outside of the balance gage locations. Data from the manual calibration of a Force Balance is used to illustrate the application of a Combined Load Diagram to a realistic data set.

  9. The Power of Slightly More than One Sample in Randomized Load Balancing

    DTIC Science & Technology

    2015-04-26

    2015 Approved for public release; distribution is unlimited. The power of slightly more than one sample in randomized load balancing The views...Box 12211 Research Triangle Park, NC 27709-2211 Load Balancing , Mean-Field Analysis, Cloud Computing REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S...2820 ABSTRACT The power of slightly more than one sample in randomized load balancing Report Title In many computing and networking applications

  10. A novel load-balanced fixed routing (LBFR) algorithm for wavelength routed optical networks

    NASA Astrophysics Data System (ADS)

    Shen, Gangxiang; Li, Yongcheng; Peng, Limei

    2011-11-01

    In the wavelength-routed optical transport networks, fixed shortest path routing is one of major lightpath service provisioning strategies, which shows simplicity in network control and operation. Specifically, once a shortest route is found for a node pair, the route is always used for any future lightpath service provisioning, which therefore does not require network control and management system to maintain any active network-wide link state database. On the other hand, the fixed shortest path routing strategy suffers from the disadvantage of unbalanced network traffic load distribution and network congestion because it keeps on employing the same fixed shortest route between each pair of nodes. To avoid the network congestion and meanwhile retain the operational simplicity, in this study we develop a Load-Balanced Fixed Routing (LBFR) algorithm. Through a training process based on a forecasted network traffic load matrix, the proposed algorithm finds a fixed (or few) route(s) for each node pair and employs the fixed route(s) for lightpath service provisioning. Different from the fixed shortest path routes between node pairs, these routes can well balance traffic load within the network when they are used for lightpath service provisioning. Compared to the traditional fixed shortest path routing algorithm, the LBFR algorithm can achieve much better lightpath blocking performance according to our simulation and analytical studies. Moreover, the performance improvement is more significant with the increase of network nodal degree.

  11. Female family physicians in obstetrics: achieving personal balance.

    PubMed Central

    Carroll, J C; Brown, J B; Reid, A J

    1995-01-01

    OBJECTIVE: To describe the experiences of female family physicians who practise obstetrics in balancing professional obligations with personal and family needs, given the unique challenges that such practice poses for these physicians. DESIGN: Qualitative study. SETTING: Ontario. PARTICIPANTS: A purposefully selected sample of nine female family physicians who met the criteria of being married, having children and currently practising obstetrics. OUTCOME MEASURES: Experiences of female family physicians and their strategies in their personal, family and professional lives that enable them to continue practising obstetrics. RESULTS: All participants continued to practise obstetrics because of the pleasure they derived from it, despite the challenges of balancing the unpredictable demands of obstetrics with their personal and family needs. To continue in obstetrics, they needed to make changes in their lives, either through a gradual, evolutionary process or in response to a critical event. Alterations to work and family arrangements permitted them to meet the challenges and led to increased satisfaction. Changes included making supportive call-group arrangements, limiting work hours and the number of births attended and securing help with household duties. CONCLUSIONS: An in-depth examination, through the use of qualitative methods, showed the reasons why some female family physicians continue to practise obstetrics despite the stressful aspects of doing so. This knowledge may be useful for women who are residents or experienced clinicians and who are considering including obstetrics in their practice. PMID:7497390

  12. Latency Hiding in Dynamic Partitioning and Load Balancing of Grid Computing Applications

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak

    2001-01-01

    The Information Power Grid (IPG) concept developed by NASA is aimed to provide a metacomputing platform for large-scale distributed computations, by hiding the intricacies of highly heterogeneous environment and yet maintaining adequate security. In this paper, we propose a latency-tolerant partitioning scheme that dynamically balances processor workloads on the.IPG, and minimizes data movement and runtime communication. By simulating an unsteady adaptive mesh application on a wide area network, we study the performance of our load balancer under the Globus environment. The number of IPG nodes, the number of processors per node, and the interconnected speeds are parameterized to derive conditions under which the IPG would be suitable for parallel distributed processing of such applications. Experimental results demonstrate that effective solution are achieved when the IPG nodes are connected by a high-speed asynchronous interconnection network.

  13. Agent based modeling of "crowdinforming" as a means of load balancing at emergency departments.

    PubMed

    Neighbour, Ryan; Oppenheimer, Luis; Mukhi, Shamir N; Friesen, Marcia R; McLeod, Robert D

    2010-01-01

    This work extends ongoing development of a framework for modeling the spread of contact-transmission infectious diseases. The framework is built upon Agent Based Modeling (ABM), with emphasis on urban scale modelling integrated with institutional models of hospital emergency departments. The method presented here includes ABM modeling an outbreak of influenza-like illness (ILI) with concomitant surges at hospital emergency departments, and illustrates the preliminary modeling of 'crowdinforming' as an intervention. 'Crowdinforming', a component of 'crowdsourcing', is characterized as the dissemination of collected and processed information back to the 'crowd' via public access. The objective of the simulation is to allow for effective policy evaluation to better inform the public of expected wait times as part of their decision making process in attending an emergency department or clinic. In effect, this is a means of providing additional decision support garnered from a simulation, prior to real world implementation. The conjecture is that more optimal service delivery can be achieved under balanced patient loads, compared to situations where some emergency departments are overextended while others are underutilized. Load balancing optimization is a common notion in many operations, and the simulation illustrates that 'crowdinforming' is a potential tool when used as a process control parameter to balance the load at emergency departments as well as serving as an effective means to direct patients during an ILI outbreak with temporary clinics deployed. The information provided in the 'crowdinforming' model is readily available in a local context, although it requires thoughtful consideration in its interpretation. The extension to a wider dissemination of information via a web service is readily achievable and presents no technical obstacles, although political obstacles may be present. The 'crowdinforming' simulation is not limited to arrivals of patients at

  14. Priority-rotating DBA with adaptive load balance for reconfigurable WDM/TDM PON

    NASA Astrophysics Data System (ADS)

    Xia, Weidong; Gan, Chaoqin; Xie, Weilun; Ni, Cuiping

    2015-12-01

    To the wavelength-division multiplexing/time-division multiplexing passive optical network (WDM/TDM PON) architecture that implements wavelength sharing and traffic redirection, a priority-rotating dynamic bandwidth allocation (DBA) algorithm is proposed in this paper. The priority of each ONU is set and rotated to meet the bandwidth demand and guarantee the fairness among optical network units (ONUs). The bandwidth allocation for priority queues is employed to avoid bandwidth monopolization and over-allocation. The bandwidth allocation for high-loaded situation and redirected traffic are discussed to achieve adaptive load balance over wavelengths and among ONUs. The simulation results show a good performance of the proposed algorithm in throughput rate and average packet delay.

  15. Self-balancing beam permits safe, easy load handling under overhang

    NASA Technical Reports Server (NTRS)

    Edwards, O. H.

    1964-01-01

    The use of a self-balancing I-beam with a counterweight and motor simplifies moving heavy loads that are inaccessible for cranes. The beam cannot be overloaded, as the counterweight will not balance the load, and thus acts as an automatic safety device.

  16. Achieving the Proper Balance Between Crew and Public Safety

    NASA Technical Reports Server (NTRS)

    Gowan, John; Rosati, Paul; Silvestri, Ray; Stahl, Ben; Wilde, Paul

    2011-01-01

    A paramount objective of all human-rated launch and reentry vehicle developers is to ensure that the risks to both the crew onboard and the public are minimized within reasonable cost, schedule, and technical constraints. Past experience has shown that proper attention to range safety requirements necessary to ensure public safety must be given early in the design phase to avoid additional operational complexities or threats to the safety of people onboard. This paper will outline the policy considerations, technical issues, and operational impacts regarding launch and reentry vehicle failure scenarios where crew and public safety are intertwined and thus addressed optimally in an integrated manner. Historical examples and lessons learned from both the Space Shuttle and Constellation Programs will be presented. Using these examples as context, the paper will discuss some operational, design, and analysis approaches to mitigate and balance the risks to people onboard and in the public. Manned vehicle perspectives from the FAA and Air Force organizations that oversee public safety will also be summarized. Finally, the paper will emphasize the need to factor policy, operational, and analysis considerations into the early design trades of new vehicles to help ensure that both crew and public safety are maximized to the greatest extent possible.

  17. Selecting boundary conditions in physiological strain analysis of the femur: Balanced loads, inertia relief method and follower load.

    PubMed

    Heyland, Mark; Trepczynski, Adam; Duda, Georg N; Zehn, Manfred; Schaser, Klaus-Dieter; Märdian, Sven

    2015-12-01

    Selection of boundary constraints may influence amount and distribution of loads. The purpose of this study is to analyze the potential of inertia relief and follower load to maintain the effects of musculoskeletal loads even under large deflections in patient specific finite element models of intact or fractured bone compared to empiric boundary constraints which have been shown to lead to physiological displacements and surface strains. The goal is to elucidate the use of boundary conditions in strain analyses of bones. Finite element models of the intact femur and a model of clinically relevant fracture stabilization by locking plate fixation were analyzed with normal walking loading conditions for different boundary conditions, specifically re-balanced loading, inertia relief and follower load. Peak principal cortex surface strains for different boundary conditions are consistent (maximum deviation 13.7%) except for inertia relief without force balancing (maximum deviation 108.4%). Influence of follower load on displacements increases with higher deflection in fracture model (from 3% to 7% for force balanced model). For load balanced models, follower load had only minor influence, though the effect increases strongly with higher deflection. Conventional constraints of fixed nodes in space should be carefully reconsidered because their type and position are challenging to justify and for their potential to introduce relevant non-physiological reaction forces. Inertia relief provides an alternative method which yields physiological strain results.

  18. LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring

    PubMed Central

    Tseng, Chinyang Henry

    2016-01-01

    In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee’s AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee’s routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node’s distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee’s AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV. PMID:27258297

  19. LBMR: Load-Balanced Multipath Routing for Wireless Data-Intensive Transmission in Real-Time Medical Monitoring.

    PubMed

    Tseng, Chinyang Henry

    2016-05-31

    In wireless networks, low-power Zigbee is an excellent network solution for wireless medical monitoring systems. Medical monitoring generally involves transmission of a large amount of data and easily causes bottleneck problems. Although Zigbee's AODV mesh routing provides extensible multi-hop data transmission to extend network coverage, it originally does not, and needs to support some form of load balancing mechanism to avoid bottlenecks. To guarantee a more reliable multi-hop data transmission for life-critical medical applications, we have developed a multipath solution, called Load-Balanced Multipath Routing (LBMR) to replace Zigbee's routing mechanism. LBMR consists of three main parts: Layer Routing Construction (LRC), a Load Estimation Algorithm (LEA), and a Route Maintenance (RM) mechanism. LRC assigns nodes into different layers based on the node's distance to the medical data gateway. Nodes can have multiple next-hops delivering medical data toward the gateway. All neighboring layer-nodes exchange flow information containing current load, which is the used by the LEA to estimate future load of next-hops to the gateway. With LBMR, nodes can choose the neighbors with the least load as the next-hops and thus can achieve load balancing and avoid bottlenecks. Furthermore, RM can detect route failures in real-time and perform route redirection to ensure routing robustness. Since LRC and LEA prevent bottlenecks while RM ensures routing fault tolerance, LBMR provides a highly reliable routing service for medical monitoring. To evaluate these accomplishments, we compare LBMR with Zigbee's AODV and another multipath protocol, AOMDV. The simulation results demonstrate LBMR achieves better load balancing, less unreachable nodes, and better packet delivery ratio than either AODV or AOMDV.

  20. Achieving the Proper Balance Between Crew and Public Safety

    NASA Technical Reports Server (NTRS)

    Gowan, John; Silvestri, Ray; Stahl, Ben; Rosati, Paul; Wilde, Paul

    2011-01-01

    A paramount objective of all human-rated launch and reentry vehicle developers is to ensure that the risks to both the crew onboard and the public are minimized within reasonable cost, schedule, and technical constraints. Past experience has shown that proper attention to range safety requirements necessary to ensure public safety must be given early in the design phase to avoid additional operational complexities or threats to the safety of people onboard, and the design engineers must give these requirements the same consideration as crew safety requirements. For human spaceflight, the primary purpose and operational concept for any flight safety system is to protect the public while maximizing the likelihood of crew survival. This paper will outline the policy considerations, technical issues, and operational impacts regarding launch and reentry vehicle failure scenarios where crew and public safety are intertwined and thus addressed optimally in an integrated manner. An overview of existing range and crew safety policy requirements will be presented. Application of these requirements and lessons learned from both the Space Shuttle and Constellation Programs will also be discussed. Using these past programs as examples, the paper will detail operational, design, and analysis approaches to mitigate and balance the risks to people onboard and in the public. Manned vehicle perspectives from the Federal Aviation Administration (FAA) and Air Force organizations that oversee public safety will be summarized as well. Finally, the paper will emphasize the need to factor policy, operational, and analysis considerations into the early design trades of new vehicles to help ensure that both crew and public safety are maximized to the greatest extent possible.

  1. Achieving the Proper Balance between Crew & Public Safety

    NASA Astrophysics Data System (ADS)

    Wilde, P.; Gowan, J.; Silvestri, R.; Stahl, B.; Rosati, P.

    2012-01-01

    A paramount objective of all human-rated launch and reentry vehicle developers is to ensure that the risks to both the crew onboard and the public are minimized within reasonable cost, schedule, and technical constraints. Past experience has shown that proper attention to range safety requirements necessary to ensure public safety must be given early in the design phase to avoid additional operational complexities or threats to the safety of people onboard, and the design engineers must give these requirements the same consideration as crew safety requirements. For human spaceflight, the primary purpose and operational concept for any flight safety system is to protect the public while maximizing the likelihood of crew survival. This paper will outline the policy considerations, technical issues, and operational impacts regarding launch and reentry vehicle failure scenarios where crew and public safety are intertwined and thus addressed optimally in an integrated manner. An overview of existing range and crew safety policy requirements will be presented. Application of these requirements and lessons learned from both the Space Shuttle and Constellation Programs will also be discussed. Using these past programs as examples, the paper will detail operational, design, and analysis approaches to mitigate and balance the risks to people onboard and in the public. Crewed vehicle perspectives from the Federal Aviation Administration and Air Force organizations that oversee public safety will be summarized as well. Finally, the paper will emphasize the need to factor policy, operational, and analysis considerations into the early design trades of new vehicles to help ensure that both crew and public safety are maximized to the greatest extent possible.

  2. Comparison of Iterative and Non-Iterative Strain-Gage Balance Load Calculation Methods

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2010-01-01

    The accuracy of iterative and non-iterative strain-gage balance load calculation methods was compared using data from the calibration of a force balance. Two iterative and one non-iterative method were investigated. In addition, transformations were applied to balance loads in order to process the calibration data in both direct read and force balance format. NASA's regression model optimization tool BALFIT was used to generate optimized regression models of the calibration data for each of the three load calculation methods. This approach made sure that the selected regression models met strict statistical quality requirements. The comparison of the standard deviation of the load residuals showed that the first iterative method may be applied to data in both the direct read and force balance format. The second iterative method, on the other hand, implicitly assumes that the primary gage sensitivities of all balance gages exist. Therefore, the second iterative method only works if the given balance data is processed in force balance format. The calibration data set was also processed using the non-iterative method. Standard deviations of the load residuals for the three load calculation methods were compared. Overall, the standard deviations show very good agreement. The load prediction accuracies of the three methods appear to be compatible as long as regression models used to analyze the calibration data meet strict statistical quality requirements. Recent improvements of the regression model optimization tool BALFIT are also discussed in the paper.

  3. Influence of Primary Gage Sensitivities on the Convergence of Balance Load Iterations

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert Manfred

    2012-01-01

    The connection between the convergence of wind tunnel balance load iterations and the existence of the primary gage sensitivities of a balance is discussed. First, basic elements of two load iteration equations that the iterative method uses in combination with results of a calibration data analysis for the prediction of balance loads are reviewed. Then, the connection between the primary gage sensitivities, the load format, the gage output format, and the convergence characteristics of the load iteration equation choices is investigated. A new criterion is also introduced that may be used to objectively determine if the primary gage sensitivity of a balance gage exists. Then, it is shown that both load iteration equations will converge as long as a suitable regression model is used for the analysis of the balance calibration data, the combined influence of non linear terms of the regression model is very small, and the primary gage sensitivities of all balance gages exist. The last requirement is fulfilled, e.g., if force balance calibration data is analyzed in force balance format. Finally, it is demonstrated that only one of the two load iteration equation choices, i.e., the iteration equation used by the primary load iteration method, converges if one or more primary gage sensitivities are missing. This situation may occur, e.g., if force balance calibration data is analyzed in direct read format using the original gage outputs. Data from the calibration of a six component force balance is used to illustrate the connection between the convergence of the load iteration equation choices and the existence of the primary gage sensitivities.

  4. Application of self-balanced loading test to socketed pile in weak rock

    NASA Astrophysics Data System (ADS)

    Cheng, Ye; Gong, Weiming; Dai, Guoliang; Wu, JingKun

    2008-11-01

    Method of self-balanced loading test differs from the traditional methods of pile test. The key equipment of the test is a cell. The cell specially designed is used to exert load which is placed in pile body. During the test, displacement values of the top plate and the bottom plate of the cell are recorded according to every level of load. So Q-S curves can be obtained. In terms of test results, the bearing capacity of pile can be judged. Equipments of the test are simply and cost of it is low. Under some special conditions, the method will take a great advantage. In Guangxi Province, tertiary mudstone distributes widely which is typical weak rock. It is usually chosen as the bearing stratum of pile foundation. In order to make full use of its high bearing capacity, pile is generally designed as belled pile. Foundations of two high-rise buildings which are close to each other are made up of belled socketed piles in weak rock. To obtain the bearing capacity of the belled socketed pile in weak rock, loading test in situ should be taken since it is not reasonable that experimental compression strength of the mudstone is used for design. The self-balanced loading test was applied to eight piles of two buildings. To get the best test effect, the assembly of cell should be taken different modes in terms of the depth that pile socketed in rock and the dimension of the enlarged toe. The assembly of cells had been taken three modes, and tests were carried on successfully. By the self-balanced loading test, the large bearing capacities of belled socketed piles were obtained. Several key parameters required in design were achieved from the tests. For the data of tests had been analyzed, the bearing performance of pile tip, pile side and whole pile was revealed. It is further realized that the bearing capacity of belled socketed pile in the mudstone will decrease after the mudstone it socketed in has been immerged. Among kinds of mineral ingredient in the mudstone

  5. Assessment of the Uniqueness of Wind Tunnel Strain-Gage Balance Load Predictions

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2016-01-01

    A new test was developed to assess the uniqueness of wind tunnel strain-gage balance load predictions that are obtained from regression models of calibration data. The test helps balance users to gain confidence in load predictions of non-traditional balance designs. It also makes it possible to better evaluate load predictions of traditional balances that are not used as originally intended. The test works for both the Iterative and Non-Iterative Methods that are used in the aerospace testing community for the prediction of balance loads. It is based on the hypothesis that the total number of independently applied balance load components must always match the total number of independently measured bridge outputs or bridge output combinations. This hypothesis is supported by a control volume analysis of the inputs and outputs of a strain-gage balance. It is concluded from the control volume analysis that the loads and bridge outputs of a balance calibration data set must separately be tested for linear independence because it cannot always be guaranteed that a linearly independent load component set will result in linearly independent bridge output measurements. Simple linear math models for the loads and bridge outputs in combination with the variance inflation factor are used to test for linear independence. A highly unique and reversible mapping between the applied load component set and the measured bridge output set is guaranteed to exist if the maximum variance inflation factor of both sets is less than the literature recommended threshold of five. Data from the calibration of a six{component force balance is used to illustrate the application of the new test to real-world data.

  6. Dynamic load balancing of matrix-vector multiplications on roadrunner compute nodes

    SciTech Connect

    Sancho Pitarch, Jose Carlos

    2009-01-01

    Hybrid architectures that combine general purpose processors with accelerators are being adopted in several large-scale systems such as the petaflop Roadrunner supercomputer at Los Alamos. In this system, dual-core Opteron host processors are tightly coupled with PowerXCell 8i processors within each compute node. In this kind of hybrid architecture, an accelerated mode of operation is typically used to offload performance hotspots in the computation to the accelerators. In this paper we explore the suitability of a variant of this acceleration mode in which the performance hotspots are actually shared between the host and the accelerators. To achieve this we have designed a new load balancing algorithm, which is optimized for the Roadrunner compute nodes, to dynamically distribute computation and associated data between the host and the accelerators at runtime. Results are presented using this approach for sparse and dense matrix-vector multiplications that show load-balancing can improve performance by up to 24% over solely using the accelerators.

  7. Evaluating Zoltan for Static Load Balancing on BlueGene Architectures

    SciTech Connect

    Kumfert, G

    2007-11-15

    The purpose of this TechBase was to evaluate the Zoltan load-balancing library from Sandia National Laboratories as a possible replacement for ParMetis, which had been the load balancer of choice for nearly a decade but does not scale to the full 64,000 processors of BlueGene/L. This evaluation was successful in producing a clear result, but the result was unfortunately negative. Although Zoltan presents a collection load-balancing algorithms, none were able to meet or exceed the combined scalability and quality of ParMetis on representative datasets.

  8. Scalable load balancing for massively parallel distributed Monte Carlo particle transport

    SciTech Connect

    O'Brien, M. J.; Brantley, P. S.; Joy, K. I.

    2013-07-01

    In order to run computer simulations efficiently on massively parallel computers with hundreds of thousands or millions of processors, care must be taken that the calculation is load balanced across the processors. Examining the workload of every processor leads to an unscalable algorithm, with run time at least as large as O(N), where N is the number of processors. We present a scalable load balancing algorithm, with run time 0(log(N)), that involves iterated processor-pair-wise balancing steps, ultimately leading to a globally balanced workload. We demonstrate scalability of the algorithm up to 2 million processors on the Sequoia supercomputer at Lawrence Livermore National Laboratory. (authors)

  9. Working Sandwich Generation Women Utilize Strategies within and between Roles to Achieve Role Balance

    PubMed Central

    Girdler, Sonya J.

    2016-01-01

    Increasingly, women simultaneously balance the roles of mother, parental carer and worker. However, individual role balance strategies among these working ‘sandwich’ generation women have not been thoroughly explored. Eighteen women combining these three roles were interviewed about their individual role balance strategies. Findings were identified through the framework analysis technique, underpinned by the Model of Juggling Occupations. Achieving and maintaining role balance was explained as a complex process accomplished through a range of strategies. Findings revealed the women used six within-role balance strategies: living with integrity, being the best you can, doing what you love, loving what you do, remembering why and searching for signs of success. The women also described six between-role balance strategies: maintaining health and wellbeing, repressing perfectionism, managing time and energy, releasing responsibility, nurturing social connection and reciprocating. These findings provide a basis for health care providers to understand and potentially support working ‘sandwich’ generation women. PMID:27305074

  10. Assessment of New Load Schedules for the Machine Calibration of a Force Balance

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Gisler, R.; Kew, R.

    2015-01-01

    New load schedules for the machine calibration of a six-component force balance are currently being developed and evaluated at the NASA Ames Balance Calibration Laboratory. One of the proposed load schedules is discussed in the paper. It has a total of 2082 points that are distributed across 16 load series. Several criteria were applied to define the load schedule. It was decided, for example, to specify the calibration load set in force balance format as this approach greatly simplifies the definition of the lower and upper bounds of the load schedule. In addition, all loads are assumed to be applied in a calibration machine by using the one-factor-at-a-time approach. At first, all single-component loads are applied in six load series. Then, three two-component load series are applied. They consist of the load pairs (N1, N2), (S1, S2), and (RM, AF). Afterwards, four three-component load series are applied. They consist of the combinations (N1, N2, AF), (S1, S2, AF), (N1, N2, RM), and (S1, S2, RM). In the next step, one four-component load series is applied. It is the load combination (N1, N2, S1, S2). Finally, two five-component load series are applied. They are the load combination (N1, N2, S1, S2, AF) and (N1, N2, S1, S2, RM). The maximum difference between loads of two subsequent data points of the load schedule is limited to 33 % of capacity. This constraint helps avoid unwanted load "jumps" in the load schedule that can have a negative impact on the performance of a calibration machine. Only loadings of the single- and two-component load series are loaded to 100 % of capacity. This approach was selected because it keeps the total number of calibration points to a reasonable limit while still allowing for the application of some of the more complex load combinations. Data from two of NASA's force balances is used to illustrate important characteristics of the proposed 2082-point calibration load schedule.

  11. Wage-Earner or Family Member? FCS Students Learn How to Achieve a Balance

    ERIC Educational Resources Information Center

    McNabb, Tamra

    2004-01-01

    Successful business people in all walks of life recognize that achieving a balance between their work lives and their families is critical to their personal happiness. Although the subject is mentioned in textbooks and seminars, very little, if any, time is spent discussing how the young career person will achieve this goal. Fortunately, potential…

  12. Valiant load-balanced robust routing under hose model for WDM mesh networks

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoning; Li, Lemin; Wang, Sheng

    2006-09-01

    In this paper, we propose Valiant Load-Balanced robust routing scheme for WDM mesh networks under the model of polyhedral uncertainty (i.e., hose model), and the proposed routing scheme is implemented with traffic grooming approach. Our Objective is to maximize the hose model throughput. A mathematic formulation of Valiant Load-Balanced robust routing is presented and three fast heuristic algorithms are also proposed. When implementing Valiant Load-Balanced robust routing scheme to WDM mesh networks, a novel traffic-grooming algorithm called MHF (minimizing hop first) is proposed. We compare the three heuristic algorithms with the VPN tree under the hose model. Finally we demonstrate in the simulation results that MHF with Valiant Load-Balanced robust routing scheme outperforms the traditional traffic-grooming algorithm in terms of the throughput for the uniform/non-uniform traffic matrix under the hose model.

  13. Impact of Load Balancing on Unstructured Adaptive Grid Computations for Distributed-Memory Multiprocessors

    NASA Technical Reports Server (NTRS)

    Sohn, Andrew; Biswas, Rupak; Simon, Horst D.

    1996-01-01

    The computational requirements for an adaptive solution of unsteady problems change as the simulation progresses. This causes workload imbalance among processors on a parallel machine which, in turn, requires significant data movement at runtime. We present a new dynamic load-balancing framework, called JOVE, that balances the workload across all processors with a global view. Whenever the computational mesh is adapted, JOVE is activated to eliminate the load imbalance. JOVE has been implemented on an IBM SP2 distributed-memory machine in MPI for portability. Experimental results for two model meshes demonstrate that mesh adaption with load balancing gives more than a sixfold improvement over one without load balancing. We also show that JOVE gives a 24-fold speedup on 64 processors compared to sequential execution.

  14. Dynamic load balancing algorithm for molecular dynamics based on Voronoi cells domain decompositions

    SciTech Connect

    Fattebert, J.-L.; Richards, D.F.; Glosli, J.N.

    2012-12-01

    We present a new algorithm for automatic parallel load balancing in classical molecular dynamics. It assumes a spatial domain decomposition of particles into Voronoi cells. It is a gradient method which attempts to minimize a cost function by displacing Voronoi sites associated with each processor/sub-domain along steepest descent directions. Excellent load balance has been obtained for quasi-2D and 3D practical applications, with up to 440·106 particles on 65,536 MPI tasks.

  15. Agent Based Modeling of “Crowdinforming” as a Means of Load Balancing at Emergency Departments

    PubMed Central

    Neighbour, Ryan; Oppenheimer, Luis; Mukhi, Shamir N.; Friesen, Marcia R.; McLeod, Robert D.

    2010-01-01

    This work extends ongoing development of a framework for modeling the spread of contact-transmission infectious diseases. The framework is built upon Agent Based Modeling (ABM), with emphasis on urban scale modelling integrated with institutional models of hospital emergency departments. The method presented here includes ABM modeling an outbreak of influenza-like illness (ILI) with concomitant surges at hospital emergency departments, and illustrates the preliminary modeling of ‘crowdinforming’ as an intervention. ‘Crowdinforming’, a component of ‘crowdsourcing’, is characterized as the dissemination of collected and processed information back to the ‘crowd’ via public access. The objective of the simulation is to allow for effective policy evaluation to better inform the public of expected wait times as part of their decision making process in attending an emergency department or clinic. In effect, this is a means of providing additional decision support garnered from a simulation, prior to real world implementation. The conjecture is that more optimal service delivery can be achieved under balanced patient loads, compared to situations where some emergency departments are overextended while others are underutilized. Load balancing optimization is a common notion in many operations, and the simulation illustrates that ‘crowdinforming’ is a potential tool when used as a process control parameter to balance the load at emergency departments as well as serving as an effective means to direct patients during an ILI outbreak with temporary clinics deployed. The information provided in the ‘crowdinforming’ model is readily available in a local context, although it requires thoughtful consideration in its interpretation. The extension to a wider dissemination of information via a web service is readily achievable and presents no technical obstacles, although political obstacles may be present. The ‘crowdinforming’ simulation is not limited to

  16. Oxidative Balance in Rats during Adaptation to Swimming Load.

    PubMed

    Elikov, A V

    2016-12-01

    The main parameters of free radical oxidation and antioxidant defense in the blood plasma, erythrocytes, and homogenates of skeletal muscles, heart, liver, lungs, and kidneys were studied in adult outbred albino male rats with different degree of adaptation to moderate exposure to swimming. The rats were trained to swim regularly over 1 month. Changes in oxidative balance varied in organs and tissues and depended on the level of training. Malonic dialdehyde content in the erythrocytes after swimming increased by 13.8% in non-trained animals, but decreased by 19.2% in trained rats. Parameters of blood plasma reflect the general oxidative balance of organs and tissues.

  17. Dynamic load balancing for petascale quantum Monte Carlo applications: The Alias method

    SciTech Connect

    Sudheer, C. D.; Krishnan, S.; Srinivasan, A.; Kent, P. R. C.

    2013-02-01

    Diffusion Monte Carlo is the most accurate widely used Quantum Monte Carlo method for the electronic structure of materials, but it requires frequent load balancing or population redistribution steps to maintain efficiency and avoid accumulation of systematic errors on parallel machines. The load balancing step can be a significant factor affecting performance, and will become more important as the number of processing elements increases. We propose a new dynamic load balancing algorithm, the Alias Method, and evaluate it theoretically and empirically. An important feature of the new algorithm is that the load can be perfectly balanced with each process receiving at most one message. It is also optimal in the maximum size of messages received by any process. We also optimize its implementation to reduce network contention, a process facilitated by the low messaging requirement of the algorithm. Empirical results on the petaflop Cray XT Jaguar supercomputer at ORNL showing up to 30% improvement in performance on 120,000 cores. The load balancing algorithm may be straightforwardly implemented in existing codes. The algorithm may also be employed by any method with many near identical computational tasks that requires load balancing.

  18. Balancing the Load: How to Engage Counselors in School Improvement

    ERIC Educational Resources Information Center

    Mallory, Barbara J.; Jackson, Mary H.

    2007-01-01

    Principals cannot lead the school improvement process alone. They must enlist the help of others in the school community. School counselors, whose role is often viewed as peripheral and isolated from teaching and learning, can help principals, teachers, students, and parents balance the duties and responsibilities involved in continuous student…

  19. Dynamic load balancing data centric storage for wireless sensor networks.

    PubMed

    Song, Seokil; Bok, Kyoungsoo; Kwak, Yun Sik; Goo, Bongeun; Kwak, Youngsik; Ko, Daesik

    2010-01-01

    In this paper, a new data centric storage that is dynamically adapted to the work load changes is proposed. The proposed data centric storage distributes the load of hot spot areas to neighboring sensor nodes by using a multilevel grid technique. The proposed method is also able to use existing routing protocols such as GPSR (Greedy Perimeter Stateless Routing) with small changes. Through simulation, the proposed method enhances the lifetime of sensor networks over one of the state-of-the-art data centric storages. We implement the proposed method based on an operating system for sensor networks, and evaluate the performance through running based on a simulation tool.

  20. Using Multi-threading for the Automatic Load Balancing of 2D Adaptive Finite Element Meshes

    NASA Technical Reports Server (NTRS)

    Heber, Gerd; Biswas, Rupak; Thulasiraman, Parimala; Gao, Guang R.; Saini, Subhash (Technical Monitor)

    1998-01-01

    In this paper, we present a multi-threaded approach for the automatic load balancing of adaptive finite element (FE) meshes The platform of our choice is the EARTH multi-threaded system which offers sufficient capabilities to tackle this problem. We implement the adaption phase of FE applications oil triangular meshes and exploit the EARTH token mechanism to automatically balance the resulting irregular and highly nonuniform workload. We discuss the results of our experiments oil EARTH-SP2, on implementation of EARTH on the IBM SP2 with different load balancing strategies that are built into the runtime system.

  1. Exercise, muscle, and the applied load-bone strength balance.

    PubMed

    Giangregorio, L; El-Kotob, R

    2017-01-01

    A fracture occurs when the applied load is greater than the bone can withstand. Clinical practice guidelines for the management of osteoporosis include recommendations for exercise; one of the few therapies where the proposed anti-fracture mechanisms that include effects on both bone strength and applied loads, where applied loads can come in the form of a fall, externally applied loads, body weight, or muscle forces. The aim of this review is to provide an overview of the clinical evidence pertaining to the potential efficacy of exercise for preventing fractures in older adults, including its direct effects on outcomes along the causal pathway to fractures (e.g., falls, posture, bone strength) and the indirect effects on muscle or the muscle-bone relationship. The evidence is examined as it pertains to application in clinical practice. Considerations for future research are discussed, such as the need for trials in individuals with low bone mass or students that evaluate whether changes in muscle mediate changes in bone. Future trials should also consider adequacy of calorie or protein intake, the confounding effect of exercise-induced weight loss, or the most appropriate therapeutic goal (e.g., strength, weight bearing, or hypertrophy) and outcome measures (e.g., fracture, disability, cost-effectiveness).

  2. Comparison of hiking stick use on lateral stability while balancing with and without a load.

    PubMed

    Jacobson, B H; Caldwell, B; Kulling, F A

    1997-08-01

    To compare hiking stick use on lateral stability while balancing with or without a load (15-kg internal frame backpack) under conditions of no stick, 1 stick, and 2 sticks for six trials 15 volunteers ages 19 to 23 years (M = 21.7 yr.) were tested six separate times on a stability platform. During randomly ordered, 1-min. trials, the length of time (sec.) the subject maintained balance (+/-10 degrees of horizontal) and the number of deviations beyond 10 degrees were recorded simultaneously. Backpack and hiking sticks were individually adjusted for each subject. A 2 x 3 repeated factor analysis of variance indicated that subjects balanced significantly longer both with and without a load while using 2 hiking sticks than 1 or 0 sticks. Significantly fewer deviations beyond 10 degrees were found when subjects were without a load and using 1 or 2 sticks versus when they used none, and no significant difference in the number of deviations were found between 1 and 2 hiking sticks. When subjects were equipped with a load, significantly improved balance was found only between the 2 sticks and no sticks. Balance was significantly enhanced by using hiking sticks, and two sticks were more effective than one while carrying a load. An increase in maintenance of static balance may reduce the possibility of falling and injury while standing on loose alpine terrain.

  3. Effects of partitioning and scheduling sparse matrix factorization on communication and load balance

    NASA Technical Reports Server (NTRS)

    Venugopal, Sesh; Naik, Vijay K.

    1991-01-01

    A block based, automatic partitioning and scheduling methodology is presented for sparse matrix factorization on distributed memory systems. Using experimental results, this technique is analyzed for communication and load imbalance overhead. To study the performance effects, these overheads were compared with those obtained from a straightforward 'wrap mapped' column assignment scheme. All experimental results were obtained using test sparse matrices from the Harwell-Boeing data set. The results show that there is a communication and load balance tradeoff. The block based method results in lower communication cost whereas the wrap mapped scheme gives better load balance.

  4. Dynamic Load Balancing For Grid Partitioning on a SP-2 Multiprocessor: A Framework

    NASA Technical Reports Server (NTRS)

    Sohn, Andrew; Simon, Horst; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    Computational requirements of full scale computational fluid dynamics change as computation progresses on a parallel machine. The change in computational intensity causes workload imbalance of processors, which in turn requires a large amount of data movement at runtime. If parallel CFD is to be successful on a parallel or massively parallel machine, balancing of the runtime load is indispensable. Here a framework is presented for dynamic load balancing for CFD applications, called Jove. One processor is designated as a decision maker Jove while others are assigned to computational fluid dynamics. Processors running CFD send flags to Jove in a predetermined number of iterations to initiate load balancing. Jove starts working on load balancing while other processors continue working with the current data and load distribution. Jove goes through several steps to decide if the new data should be taken, including preliminary evaluate, partition, processor reassignment, cost evaluation, and decision. Jove running on a single IBM SP2 node has been completely implemented. Preliminary experimental results show that the Jove approach to dynamic load balancing can be effective for full scale grid partitioning on the target machine IBM SP2.

  5. Dynamic Load Balancing for Finite Element Calculations on Parallel Computers. Chapter 1

    NASA Technical Reports Server (NTRS)

    Pramono, Eddy; Simon, Horst D.; Sohn, Andrew; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    Computational requirements of full scale computational fluid dynamics change as computation progresses on a parallel machine. The change in computational intensity causes workload imbalance of processors, which in turn requires a large amount of data movement at runtime. If parallel CFD is to be successful on a parallel or massively parallel machine, balancing of the runtime load is indispensable. Here a frame work is presented for dynamic load balancing for CFD applications, called Jove. One processor is designated as a decision maker Jove while others are assigned to computational fluid dynamics. Processors running CFD send flags to Jove in a predetermined number of iterations to initiate load balancing. Jove starts working on load balancing while other processors continue working with the current data and load distribution. Jove goes through several steps to decide if the new data should be taken, including preliminary evaluate, partition, processor reassignment, cost evaluation, and decision. Jove running on a single SP2 node has been completely implemented. Preliminary experimental results show that the Jove approach to dynamic load balancing can be effective for full scale grid partitioning on the target machine SP2.

  6. Dynamic Load Balancing for Grid Partitioning on a SP-2 Multiprocessor: A Framework

    NASA Technical Reports Server (NTRS)

    Sohn, Andrew; Simon, Horst; Lasinski, T. A. (Technical Monitor)

    1994-01-01

    Computational requirements of full scale computational fluid dynamics change as computation progresses on a parallel machine. The change in computational intensity causes workload imbalance of processors, which in turn requires a large amount of data movement at runtime. If parallel CFD is to be successful on a parallel or massively parallel machine, balancing of the runtime load is indispensable. Here a framework is presented for dynamic load balancing for CFD applications, called Jove. One processor is designated as a decision maker Jove while others are assigned to computational fluid dynamics. Processors running CFD send flags to Jove in a predetermined number of iterations to initiate load balancing. Jove starts working on load balancing while other processors continue working with the current data and load distribution. Jove goes through several steps to decide if the new data should be taken, including preliminary evaluate, partition, processor reassignment, cost evaluation, and decision. Jove running on a single EBM SP2 node has been completely implemented. Preliminary experimental results show that the Jove approach to dynamic load balancing can be effective for full scale grid partitioning on the target machine IBM SP2.

  7. Hip joint contact loads in older adults during recovery from forward loss of balance by stepping.

    PubMed

    Graham, David F; Modenese, Luca; Trewartha, Grant; Carty, Christopher P; Constantinou, Maria; Lloyd, David G; Barrett, Rod S

    2016-09-06

    Hip joint contact loads during activities of daily living are not generally considered high enough to cause acute bone or joint injury. However there is some evidence that hip joint loads may be higher in stumble recovery from loss of balance. A common laboratory method used to evaluate balance recovery performance involves suddenly releasing participants from various static forward lean magnitudes (perturbation intensities). Prior studies have shown that when released from the same perturbation intensity, some older adults are able to recover with a single step, whereas others require multiple steps. The main purpose of this study was to use a musculoskeletal model to determine the effect of three balance perturbation intensities and the use of single versus multiple recovery steps on hip joint contact loads during recovery from forward loss of balance in community dwelling older adults (n=76). We also evaluated the association of peak hip contact loads with perturbation intensity, step length and trunk flexion angle at foot contact at each participant׳s maximum recoverable lean angle (MRLA). Peak hip joint contact loads were computed using muscle force estimates obtained using Static Optimisation and increased as lean magnitude was increased and were on average 32% higher for Single Steppers compared to Multiple Steppers. At the MRLA, peak hip contact loads ranged from 4.3 to 12.7 body weights and multiple linear stepwise regression further revealed that initial lean angle, step length and trunk angle at foot contact together explained 27% of the total variance in hip joint contact load. Overall findings indicated that older adults experience peak hip joint contact loads during maximal balance recovery by stepping that in some cases exceeded loads reported to cause mechanical failure of cadaver femurs. While step length and trunk flexion angle are strong predictors of step recovery performance they are at best moderate predictors of peak hip joint loading.

  8. Global Load Balancing with Parallel Mesh Adaption on Distributed-Memory Systems

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Oliker, Leonid; Sohn, Andrew

    1996-01-01

    Dynamic mesh adaption on unstructured grids is a powerful tool for efficiently computing unsteady problems to resolve solution features of interest. Unfortunately, this causes load imbalance among processors on a parallel machine. This paper describes the parallel implementation of a tetrahedral mesh adaption scheme and a new global load balancing method. A heuristic remapping algorithm is presented that assigns partitions to processors such that the redistribution cost is minimized. Results indicate that the parallel performance of the mesh adaption code depends on the nature of the adaption region and show a 35.5X speedup on 64 processors of an SP2 when 35% of the mesh is randomly adapted. For large-scale scientific computations, our load balancing strategy gives almost a sixfold reduction in solver execution times over non-balanced loads. Furthermore, our heuristic remapper yields processor assignments that are less than 3% off the optimal solutions but requires only 1% of the computational time.

  9. Global Load Balancing with Parallel Mesh Adaption on Distributed-Memory Systems

    NASA Technical Reports Server (NTRS)

    Biswas, Rupak; Oliker, Leonid; Sohn, Andrew

    1996-01-01

    Dynamic mesh adaptation on unstructured grids is a powerful tool for efficiently computing unsteady problems to resolve solution features of interest. Unfortunately, this causes load inbalances among processors on a parallel machine. This paper described the parallel implementation of a tetrahedral mesh adaption scheme and a new global load balancing method. A heuristic remapping algorithm is presented that assigns partitions to processors such that the redistribution coast is minimized. Results indicate that the parallel performance of the mesh adaption code depends on the nature of the adaption region and show a 35.5X speedup on 64 processors of an SP2 when 35 percent of the mesh is randomly adapted. For large scale scientific computations, our load balancing strategy gives an almost sixfold reduction in solver execution times over non-balanced loads. Furthermore, our heuristic remappier yields processor assignments that are less than 3 percent of the optimal solutions, but requires only 1 percent of the computational time.

  10. Biologically inspired load balancing mechanism in neocortical competitive learning

    PubMed Central

    Tal, Amir; Peled, Noam; Siegelmann, Hava T.

    2014-01-01

    A unique delayed self-inhibitory pathway mediated by layer 5 Martinotti Cells was studied in a biologically inspired neural network simulation. Inclusion of this pathway along with layer 5 basket cell lateral inhibition caused balanced competitive learning, which led to the formation of neuronal clusters as were indeed reported in the same region. Martinotti pathway proves to act as a learning “conscience,” causing overly successful regions in the network to restrict themselves and let others fire. It thus spreads connectivity more evenly throughout the net and solves the “dead unit” problem of clustering algorithms in a local and biologically plausible manner. PMID:24653679

  11. Balancing Dreams and Realities: The College Choice Process for High-Achieving Latinas

    ERIC Educational Resources Information Center

    Hernández, Ebelia

    2015-01-01

    This study's narratives of 17 high-achieving Latinas revealed how their college choice was a constant balancing of individual and family expectations, being "close, but far enough away," and "getting your money's worth." With the use of critical race theory, further analysis revealed the influence of "familismo" on…

  12. Dynamic load balancing for petascale quantum Monte Carlo applications: The Alias method

    NASA Astrophysics Data System (ADS)

    Sudheer, C. D.; Krishnan, S.; Srinivasan, A.; Kent, P. R. C.

    2013-02-01

    Diffusion Monte Carlo is a highly accurate Quantum Monte Carlo method for electronic structure calculations of materials, but it requires frequent load balancing or population redistribution steps to maintain efficiency on parallel machines. This step can be a significant factor affecting performance, and will become more important as the number of processing elements increases. We propose a new dynamic load balancing algorithm, the Alias Method, and evaluate it theoretically and empirically. An important feature of the new algorithm is that the load can be perfectly balanced with each process receiving at most one message. It is also optimal in the maximum size of messages received by any process. We also optimize its implementation to reduce network contention, a process facilitated by the low messaging requirement of the algorithm: a simple renumbering of the MPI ranks based on proximity and a space filling curve significantly improves the MPI Allgather performance. Empirical results on the petaflop Cray XT Jaguar supercomputer at ORNL show up to 30% improvement in performance on 120,000 cores. The load balancing algorithm may be straightforwardly implemented in existing codes. The algorithm may also be employed by any method with many near identical computational tasks that require load balancing.

  13. Rectangular Dielectric-loaded Structures for Achieving High Acceleration Gradients

    NASA Astrophysics Data System (ADS)

    Wang, Changbiao; Yakovlev, V. P.; Marshall, T. C.; LaPointe, M. A.; Hirshfield, J. L.

    2006-11-01

    Rectangular dielectric-loaded structures are described that may sustain higher acceleration gradients than conventional all-metal structures with similar apertures. One structure is a test cavity designed to ascertain the breakdown limits of dielectrics, while a second structure could be the basis for a two-beam accelerator. CVD diamond is an attractive dielectric for a high-gradient structure, since the published DC breakdown limit for CVD diamond is ˜ 2 GV/m, although the limit has never been determined for RF fields. Here we present a design of a diamond-lined test cavity to measure the breakdown limit. The designed cavity operates at 34 GHz, where with 10-MW input power it is expected to produce an ˜800 MV/m field on the diamond surface—provided breakdown is avoided. The two channel rectangular dielectric-loaded waveguide could be a two-beam accelerator structure, in which a drive beam is in one channel and an accelerated beam is in the other. The RF power produced by drive bunches in the drive channel is continuously coupled to the acceleration channel. The ratio of fields in the channels (transformer ratio) for the operating mode can be designed by adjusting the dimensions of the structure. An example of the two-channel structure is described, in which a train of five 3-nC drive bunches excites wake fields in the accelerator channel of up to 1.3 GV/m with a transformer ratio of 10 for the design mode.

  14. Load balancing and closed chain multiple arm control

    NASA Technical Reports Server (NTRS)

    Kreutz, Kenneth; Lokshin, Anatole

    1988-01-01

    The authors give the general dynamical equations for several rigid link manipulators rigidly grasping a commonly held rigid object. It is shown that the number of arm-configuration degrees of freedom lost due to imposing the closed-loop kinematic constraints is the same as the number of degrees of freedom gained for controlling the internal forces of the closed-chain system. This number is equal to the dimension of the kernel of the Jacobian operator which transforms contact forces to the net forces acting on the held object, and it is shown that this kernel can be identified with the subspace of controllable internal forces of the closed-chain system. Control of these forces makes it possible to regulate the grasping forces imparted to the held object or to control the load taken by each arm. It is shown that the internal forces can be influenced without affecting the control of the configuration degrees of freedom. Control laws of the feedback linearization type are shown to be useful for controlling the location and attitude of a frame fixed with respect to the held object, while simultaneously controlling the internal forces of the closed-chain system. Force feedback can be used to linearize and control the system even when the held object has unknown mass properties. If saturation effects are ignored, an unconstrained quadratic optimization can be performed to distribute the load optimally among the joint actuators.

  15. Dynamic Load-Balancing for Distributed Heterogeneous Computing of Parallel CFD Problems

    NASA Technical Reports Server (NTRS)

    Ecer, A.; Chien, Y. P.; Boenisch, T.; Akay, H. U.

    2000-01-01

    The developed methodology is aimed at improving the efficiency of executing block-structured algorithms on parallel, distributed, heterogeneous computers. The basic approach of these algorithms is to divide the flow domain into many sub- domains called blocks, and solve the governing equations over these blocks. Dynamic load balancing problem is defined as the efficient distribution of the blocks among the available processors over a period of several hours of computations. In environments with computers of different architecture, operating systems, CPU speed, memory size, load, and network speed, balancing the loads and managing the communication between processors becomes crucial. Load balancing software tools for mutually dependent parallel processes have been created to efficiently utilize an advanced computation environment and algorithms. These tools are dynamic in nature because of the chances in the computer environment during execution time. More recently, these tools were extended to a second operating system: NT. In this paper, the problems associated with this application will be discussed. Also, the developed algorithms were combined with the load sharing capability of LSF to efficiently utilize workstation clusters for parallel computing. Finally, results will be presented on running a NASA based code ADPAC to demonstrate the developed tools for dynamic load balancing.

  16. Dynamic Load Balancing for Adaptive Computations on Distributed-Memory Machines

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dynamic load balancing is central to adaptive mesh-based computations on large-scale parallel computers. The principal investigator has investigated various issues on the dynamic load balancing problem under NASA JOVE and JAG rants. The major accomplishments of the project are two graph partitioning algorithms and a load balancing framework. The S-HARP dynamic graph partitioner is known to be the fastest among the known dynamic graph partitioners to date. It can partition a graph of over 100,000 vertices in 0.25 seconds on a 64- processor Cray T3E distributed-memory multiprocessor while maintaining the scalability of over 16-fold speedup. Other known and widely used dynamic graph partitioners take over a second or two while giving low scalability of a few fold speedup on 64 processors. These results have been published in journals and peer-reviewed flagship conferences.

  17. A Universal Tare Load Prediction Algorithm for Strain-Gage Balance Calibration Data Analysis

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2011-01-01

    An algorithm is discussed that may be used to estimate tare loads of wind tunnel strain-gage balance calibration data. The algorithm was originally developed by R. Galway of IAR/NRC Canada and has been described in the literature for the iterative analysis technique. Basic ideas of Galway's algorithm, however, are universally applicable and work for both the iterative and the non-iterative analysis technique. A recent modification of Galway's algorithm is presented that improves the convergence behavior of the tare load prediction process if it is used in combination with the non-iterative analysis technique. The modified algorithm allows an analyst to use an alternate method for the calculation of intermediate non-linear tare load estimates whenever Galway's original approach does not lead to a convergence of the tare load iterations. It is also shown in detail how Galway's algorithm may be applied to the non-iterative analysis technique. Hand load data from the calibration of a six-component force balance is used to illustrate the application of the original and modified tare load prediction method. During the analysis of the data both the iterative and the non-iterative analysis technique were applied. Overall, predicted tare loads for combinations of the two tare load prediction methods and the two balance data analysis techniques showed excellent agreement as long as the tare load iterations converged. The modified algorithm, however, appears to have an advantage over the original algorithm when absolute voltage measurements of gage outputs are processed using the non-iterative analysis technique. In these situations only the modified algorithm converged because it uses an exact solution of the intermediate non-linear tare load estimate for the tare load iteration.

  18. Scan Directed Load Balancing for Highly-Parallel Mesh-Connected Computers

    DTIC Science & Technology

    1991-07-01

    DTIC ~ ELECTE OCT 2 41991 AD-A242 045 Scan Directed Load Balancing for Highly-Parallel Mesh-Connected Computers’ Edoardo S. Biagioni Jan F. Prins...Department of Computer Science University of North Carolina Chapel Hill, N.C. 27599-3175 USA biagioni @cs.unc.edu prinsOcs.unc.edu Abstract Scan Directed...MasPar Computer Corpora- tion. Bibliography [1] Edoardo S. Biagioni . Scan Directed Load Balancing. PhD thesis., University of North Carolina, Chapel Hill

  19. A Framework for Load Balancing of Tensor Contraction Expressions via Dynamic Task Partitioning

    SciTech Connect

    Lai, Pai-Wei; Stock, Kevin; Rajbhandari, Samyam; Krishnamoorthy, Sriram; Sadayappan, Ponnuswamy

    2013-11-17

    In this paper, we introduce the Dynamic Load-balanced Tensor Contractions (DLTC), a domain-specific library for efficient task parallel execution of tensor contraction expressions, a class of computation encountered in quantum chemistry and physics. Our framework decomposes each contraction into smaller unit of tasks, represented by an abstraction referred to as iterators. We exploit an extra level of parallelism by having tasks across independent contractions executed concurrently through a dynamic load balancing run- time. We demonstrate the improved performance, scalability, and flexibility for the computation of tensor contraction expressions on parallel computers using examples from coupled cluster methods.

  20. A dynamic ant colony optimization for load balancing in MRN/MLN

    NASA Astrophysics Data System (ADS)

    Lu, Le; Huang, Shanguo; Gu, Wanyi

    2011-12-01

    Ant Colony Optimization (ACO) is a popular research field these years. Ants choose paths where pheromone concentration is higher and modify the environment they visited. However, in the context of multi-service in multi-level and multi-domain optical network, the capacity of inter-domain links is limited. Congestion may be occurred at inter-domain links. In this paper, ant colony optimization algorithm based on load balancing is proposed. Ants follow paths not just depend on pheromone alone, we also take available resources on the link as a factor too. Simulations show the proposed method could reduce the traffic blocking probability, and realize load balancing within the network.

  1. Effect of armor and carrying load on body balance and leg muscle function.

    PubMed

    Park, Huiju; Branson, Donna; Kim, Seonyoung; Warren, Aric; Jacobson, Bert; Petrova, Adriana; Peksoz, Semra; Kamenidis, Panagiotis

    2014-01-01

    This study investigated the impact of weight and weight distribution of body armor and load carriage on static body balance and leg muscle function. A series of human performance tests were conducted with seven male, healthy, right-handed military students in seven garment conditions with varying weight and weight distributions. Static body balance was assessed by analyzing the trajectory of center of plantar pressure and symmetry of weight bearing in the feet. Leg muscle functions were assessed by analyzing the peak electromyography amplitude of four selected leg muscles during walking. Results of this study showed that uneven weight distribution of garment and load beyond an additional 9 kg impaired static body balance as evidenced by increased sway of center of plantar pressure and asymmetry of weight bearing in the feet. Added weight on non-dominant side of the body created greater impediment to static balance. Increased garment weight also elevated peak EMG amplitude in the rectus femoris to maintain body balance and in the medial gastrocnemius to increase propulsive force. Negative impacts on balance and leg muscle function with increased carrying loads, particularly with an uneven weight distribution, should be stressed to soldiers, designers, and sports enthusiasts.

  2. Prediction Interval Development for Wind-Tunnel Balance Check-Loading

    NASA Technical Reports Server (NTRS)

    Landman, Drew; Toro, Kenneth G.; Commo, Sean A.; Lynn, Keith C.

    2014-01-01

    Results from the Facility Analysis Verification and Operational Reliability project revealed a critical gap in capability in ground-based aeronautics research applications. Without a standardized process for check-loading the wind-tunnel balance or the model system, the quality of the aerodynamic force data collected varied significantly between facilities. A prediction interval is required in order to confirm a check-loading. The prediction interval provides an expected upper and lower bound on balance load prediction at a given confidence level. A method has been developed which accounts for sources of variability due to calibration and check-load application. The prediction interval method of calculation and a case study demonstrating its use is provided. Validation of the methods is demonstrated for the case study based on the probability of capture of confirmation points.

  3. A survey on investigating the need for intelligent power-aware load balanced routing protocols for handling critical links in MANETs.

    PubMed

    Sivakumar, B; Bhalaji, N; Sivakumar, D

    2014-01-01

    In mobile ad hoc networks connectivity is always an issue of concern. Due to dynamism in the behavior of mobile nodes, efficiency shall be achieved only with the assumption of good network infrastructure. Presence of critical links results in deterioration which should be detected in advance to retain the prevailing communication setup. This paper discusses a short survey on the specialized algorithms and protocols related to energy efficient load balancing for critical link detection in the recent literature. This paper also suggests a machine learning based hybrid power-aware approach for handling critical nodes via load balancing.

  4. A Survey on Investigating the Need for Intelligent Power-Aware Load Balanced Routing Protocols for Handling Critical Links in MANETs

    PubMed Central

    Sivakumar, B.; Bhalaji, N.; Sivakumar, D.

    2014-01-01

    In mobile ad hoc networks connectivity is always an issue of concern. Due to dynamism in the behavior of mobile nodes, efficiency shall be achieved only with the assumption of good network infrastructure. Presence of critical links results in deterioration which should be detected in advance to retain the prevailing communication setup. This paper discusses a short survey on the specialized algorithms and protocols related to energy efficient load balancing for critical link detection in the recent literature. This paper also suggests a machine learning based hybrid power-aware approach for handling critical nodes via load balancing. PMID:24790546

  5. Balancing

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    At many occasions we are asked to achieve a “balance” in our lives: when it comes, for example, to work and food. Balancing is crucial in game design as well as many have pointed out. In games with a meaningful purpose, however, balancing is remarkably different. It involves the balancing of three different worlds, the worlds of Reality, Meaning, and Play. From the experience of designing Levee Patroller, I observed that different types of tensions can come into existence that require balancing. It is possible to conceive of within-worlds dilemmas, between-worlds dilemmas, and trilemmas. The first, the within-world dilemmas, only take place within one of the worlds. We can think, for example, of a user interface problem which just relates to the world of Play. The second, the between-worlds dilemmas, have to do with a tension in which two worlds are predominantly involved. Choosing between a cartoon or a realistic style concerns, for instance, a tension between Reality and Play. Finally, the trilemmas are those in which all three worlds play an important role. For each of the types of tensions, I will give in this level a concrete example from the development of Levee Patroller. Although these examples come from just one game, I think the examples can be exemplary for other game development projects as they may represent stereotypical tensions. Therefore, to achieve harmony in any of these forthcoming games, it is worthwhile to study the struggles we had to deal with.

  6. Neurons within the same network independently achieve conserved output by differentially balancing variable conductance magnitudes.

    PubMed

    Ransdell, Joseph L; Nair, Satish S; Schulz, David J

    2013-06-12

    Biological and theoretical evidence suggest that individual neurons may achieve similar outputs by differentially balancing variable underlying ionic conductances. Despite the substantial amount of data consistent with this idea, a direct biological demonstration that cells with conserved output, particularly within the same network, achieve these outputs via different solutions has been difficult to achieve. Here we demonstrate definitively that neurons from native neural networks with highly similar output achieve this conserved output by differentially tuning underlying conductance magnitudes. Multiple motor neurons of the crab (Cancer borealis) cardiac ganglion have highly conserved output within a preparation, despite showing a 2-4-fold range of conductance magnitudes. By blocking subsets of these currents, we demonstrate that the remaining conductances become unbalanced, causing disparate output as a result. Therefore, as strategies to understand neuronal excitability become increasingly sophisticated, it is important that such variability in excitability of neurons, even among those within the same individual, is taken into account.

  7. Design and implementation of web server soft load balancing in small and medium-sized enterprise

    NASA Astrophysics Data System (ADS)

    Yan, Liu

    2011-12-01

    With the expansion of business scale, small and medium-sized enterprises began to use information platform to improve their management and competition ability, the server becomes the core factor which restricts the enterprise's infomationization construction. This paper puts forward a suitable design scheme for small and medium-sized enterprise web server soft load balancing, and proved it effective through experiment.

  8. Accelerating Multiple Compound Comparison Using LINGO-Based Load-Balancing Strategies on Multi-GPUs

    PubMed Central

    Lin, Chun-Yuan; Wang, Chung-Hung; Hung, Che-Lun; Lin, Yu-Shiang

    2015-01-01

    Compound comparison is an important task for the computational chemistry. By the comparison results, potential inhibitors can be found and then used for the pharmacy experiments. The time complexity of a pairwise compound comparison is O(n2), where n is the maximal length of compounds. In general, the length of compounds is tens to hundreds, and the computation time is small. However, more and more compounds have been synthesized and extracted now, even more than tens of millions. Therefore, it still will be time-consuming when comparing with a large amount of compounds (seen as a multiple compound comparison problem, abbreviated to MCC). The intrinsic time complexity of MCC problem is O(k2n2) with k compounds of maximal length n. In this paper, we propose a GPU-based algorithm for MCC problem, called CUDA-MCC, on single- and multi-GPUs. Four LINGO-based load-balancing strategies are considered in CUDA-MCC in order to accelerate the computation speed among thread blocks on GPUs. CUDA-MCC was implemented by C+OpenMP+CUDA. CUDA-MCC achieved 45 times and 391 times faster than its CPU version on a single NVIDIA Tesla K20m GPU card and a dual-NVIDIA Tesla K20m GPU card, respectively, under the experimental results. PMID:26491652

  9. Accelerating Multiple Compound Comparison Using LINGO-Based Load-Balancing Strategies on Multi-GPUs.

    PubMed

    Lin, Chun-Yuan; Wang, Chung-Hung; Hung, Che-Lun; Lin, Yu-Shiang

    2015-01-01

    Compound comparison is an important task for the computational chemistry. By the comparison results, potential inhibitors can be found and then used for the pharmacy experiments. The time complexity of a pairwise compound comparison is O(n (2)), where n is the maximal length of compounds. In general, the length of compounds is tens to hundreds, and the computation time is small. However, more and more compounds have been synthesized and extracted now, even more than tens of millions. Therefore, it still will be time-consuming when comparing with a large amount of compounds (seen as a multiple compound comparison problem, abbreviated to MCC). The intrinsic time complexity of MCC problem is O(k (2) n (2)) with k compounds of maximal length n. In this paper, we propose a GPU-based algorithm for MCC problem, called CUDA-MCC, on single- and multi-GPUs. Four LINGO-based load-balancing strategies are considered in CUDA-MCC in order to accelerate the computation speed among thread blocks on GPUs. CUDA-MCC was implemented by C+OpenMP+CUDA. CUDA-MCC achieved 45 times and 391 times faster than its CPU version on a single NVIDIA Tesla K20m GPU card and a dual-NVIDIA Tesla K20m GPU card, respectively, under the experimental results.

  10. Gammon - A load balancing strategy for local computer systems with multiaccess networks

    NASA Technical Reports Server (NTRS)

    Baumgartner, Katherine M.; Wah, Benjamin W.

    1989-01-01

    Consideration is given to an efficient load-balancing strategy, Gammon (global allocation from maximum to minimum in constant time), for distributed computing systems connected by multiaccess local area networks. The broadcast capability of these networks is utilized to implement an identification procedure at the applications level for the maximally and the minimally loaded processors. The search technique has an average overhead which is independent of the number of participating stations. An implementation of Gammon on a network of Sun workstations is described. Its performance is found to be better than that of other known methods.

  11. Method of up-front load balancing for local memory parallel processors

    NASA Technical Reports Server (NTRS)

    Baffes, Paul Thomas (Inventor)

    1990-01-01

    In a parallel processing computer system with multiple processing units and shared memory, a method is disclosed for uniformly balancing the aggregate computational load in, and utilizing minimal memory by, a network having identical computations to be executed at each connection therein. Read-only and read-write memory are subdivided into a plurality of process sets, which function like artificial processing units. Said plurality of process sets is iteratively merged and reduced to the number of processing units without exceeding the balance load. Said merger is based upon the value of a partition threshold, which is a measure of the memory utilization. The turnaround time and memory savings of the instant method are functions of the number of processing units available and the number of partitions into which the memory is subdivided. Typical results of the preferred embodiment yielded memory savings of from sixty to seventy five percent.

  12. Heuristic procedure for the assembly line balancing problem with postural load smoothness.

    PubMed

    Jaturanonda, Chorkaew; Nanthavanij, Suebsak; Das, Sanchoy K

    2013-01-01

    This paper presents a heuristic procedure for assigning assembly tasks to workstations where both productivity and ergonomics issues are considered concurrently. The procedure uses Kilbridge and Wester's algorithm to obtain an initial task-workstation assignment solution which minimizes the balance delay of an assembly line. A task reassignment algorithm was applied to improve the initial solution by exchanging assembly tasks, which smooth postural load among workers, between workstations. A composite index of variation was used to measure the effectiveness of the task-workstation assignment solution. On the basis of clothes assembling, it was found that the task-workstation assignment solution with a minimum composite index of variation can be obtained with relatively equal weights in balance delay and postural load.

  13. Comparing Two Opacity Models in Monte Carlo Radiative Heat Transfer: Computational Efficiency and Parallel Load Balancing

    NASA Astrophysics Data System (ADS)

    Cleveland, Mathew A.; Palmer, Todd S.

    2013-09-01

    Thermal heating from radiative heat transfer can have a significant effect on combustion systems. A variety of models have been developed to represent the strongly varying opacities found in combustion gases (Goutiere et al., 2000). This work evaluates the computational efficiency and load balance issues associated with two opacity models implemented in a 3D parallel Monte Carlo solver: the spectral-line-based weighted sum of gray gases (SLW) (Denison and Webb, 1993) and the spectral line-by-line (LBL) (Wang and Modest, 2007) opacity models. The parallel performance of the opacity models is evaluated using the Su and Olson (1999) frequency-dependent semi-analytic benchmark problem. Weak scaling, strong scaling, and history scaling studies were performed and comparisons were made for each opacity model. Comparisons of load balance sensitivities to these types of scaling were also evaluated. It was found that the SLW model has some attributes that might be valuable in a select set of parallel problems.

  14. Characteristics of Nitrogen Balances of Large-scale Stock Farms and Reduction of Environmental Nitrogen Loads

    NASA Astrophysics Data System (ADS)

    Hattori, Toshihiro; Takamatsu, Rieko

    We calculated nitrogen balances on farm gate and soil surface on large-scale stock farms and discussed methods for reducing environmental nitrogen loads. Four different types of public stock farms (organic beef, calf supply and daily cows) were surveyed in Aomori Prefecture. (1) Farm gate and soil surface nitrogen inflows were both larger than the respective outflows on all types of farms. Farm gate nitrogen balance for beef farms were worse than that for dairy farms. (2) Soil surface nitrogen outflows and soil nitrogen retention were in proportion to soil surface nitrogen inflows. (3) Reductions in soil surface nitrogen retention were influenced by soil surface nitrogen inflows. (4) In order to reduce farm gate nitrogen retention, inflows of formula feed and chemical fertilizer need to be reduced. (5) In order to reduce soil surface nitrogen retention, inflows of fertilizer need to be reduced and nitrogen balance needs to be controlled.

  15. A hybrid approach to achieving both marginal and conditional balances for stratification variables in sequential clinical trials.

    PubMed

    Lin, Yunzhi; Su, Zheng

    2013-01-01

    Various methods exist in the literature for achieving marginal balance for baseline stratification variables in sequential clinical trials. One major limitation with balancing on the margins of the stratification variables is that there is an efficiency loss when the primary analysis is stratified. To preserve the efficiency of a stratified analysis one recently proposed approach balances on the crossing of the stratification variables included in the analysis, which achieves conditional balance for the variables. A hybrid approach to achieving both marginal and conditional balances in sequential clinical trials is proposed, which is applicable to both continuous and categorical stratification variables. Numerical results based on extensive simulation studies and a real dataset show that the proposed approach outperforms the existing ones and is particularly useful when both additive and stratified models are planned for a trial.

  16. Load Balancing and Data Locality in the Parallelization of the Fast Multipole Algorithm

    NASA Astrophysics Data System (ADS)

    Banicescu, Ioana

    Scientific problems are often irregular, large and computationally intensive. Efficient parallel implementations of algorithms that are employed in finding solutions to these problems play an important role in the development of science. This thesis studies the parallelization of a certain class of irregular scientific problems, the N -body problem, using a classical hierarchical algorithm: the Fast Multipole Algorithm (FMA). Hierarchical N-body algorithms in general, and the FMA in particular, are amenable to parallel execution. However, performance gains are difficult to obtain, due to load imbalances that are primarily caused by the irregular distribution of bodies and of computation domains. Understanding application characteristics is essential for obtaining high performance implementations on parallel machines. After surveying the available parallelism in the FMA, we address the problem of exploiting this parallelism with partitioning and scheduling techniques that optimally map it onto a parallel machine, the KSR1. The KSR1 is a parallel shared address-space machine with a hierarchical cache-only architecture. The tension between maintaining data locality and balancing processor loads requires a scheduling scheme that combines static techniques (that exploit data locality) with dynamic techniques (that improve load balancing). An effective combined scheduling scheme that balances processor loads and maintains locality, by exploiting self-similarity properties of fractals, is Fractiling. Fractiling is based on a probabilistic analysis. It thus accommodates load imbalances caused by predictable events (such as irregular data) as well as unpredictable events (such as data access latency). Fractiling adapts to algorithmic and system induced load imbalances while maximizing data locality. We used Fractiling to schedule a parallel FMA on the KSR1. Our parallel 2-d and 3-d FMA implementations were run using uniform and nonuniform data set distributions under a

  17. A network flow model for load balancing in circuit-switched multicomputers

    NASA Technical Reports Server (NTRS)

    Bokhari, Shahid H.

    1993-01-01

    In multicomputers that utilize circuit switching or wormhole routing, communication overhead depends largely on link contention - the variation due to distance between nodes is negligible. This has a major impact on the load balancing problem. In this case, there are some nodes with excess load (sources) and others with deficit load (sinks) and it is required to find a matching of sources to sinks that avoids contention. The problem is made complex by the hardwired routing on currently available machines: the user can control only which nodes communicate but not how the messages are routed. Network flow models of message flow in the mesh and the hypercube were developed to solve this problem. The crucial property of these models is the correspondence between minimum cost flows and correctly routed messages. To solve a given load balancing problem, a minimum cost flow algorithm is applied to the network. This permits one to determine efficiently a maximum contention free matching of sources to sinks which, in turn, tells one how much of the given imbalance can be eliminated without contention.

  18. A network flow model for load balancing in circuit-switched multicomputers

    NASA Technical Reports Server (NTRS)

    Bokhari, Shahid H.

    1990-01-01

    In multicomputers that utilize circuit switching or wormhole routing, communication overhead depends largely on link contention - the variation due to distance between nodes is negligible. This has a major impact on the load balancing problem. In this case, there are some nodes with excess load (sources) and others with deficit load (sinks) and it is required to find a matching of sources to sinks that avoids contention. The problem is made complex by the hardwired routing on currently available machines: the user can control only which nodes communicate but not how the messages are routed. Network flow models of message flow in the mesh and the hypercube were developed to solve this problem. The crucial property of these models is the correspondence between minimum cost flows and correctly routed messages. To solve a given load balancing problem, a minimum cost flow algorithm is applied to the network. This permits one to determine efficiently a maximum contention free matching of sources to sinks which, in turn, tells one how much of the given imbalance can be eliminated without contention.

  19. Development of a dual strain gage balance system for measuring light loads

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W.

    1989-01-01

    A strain-gage-balance (SGB) force-measurement system is described which was designed to meet light-load requirements for an airfoil model tested in the NASA Langley low-turbulence pressure tunnel (LTPT). This system was developed to obtain direct force data needed to verify calculated pressure/force correlations used in previous aerodynamic tests. The three-component force-measurement system was designed so that the SGBs would simultaneously support and measure the following loads: weight of the airfoil (approximately 3.0 lbf); 8.0 lbf of lift; 0.5 lbf of drag; and 16.0 in. lbf of pitching moment. In addition to these design loads, the system was required to withstand 100-percent overload on all three components. The system comprises an airfoil, two SGBs, a thermal flexure, and a mounting plate. The installation of the system in the LTPT is also discussed.

  20. The effects of load carriage and bracing on the balance of schoolgirls with adolescent idiopathic scoliosis.

    PubMed

    Chow, Daniel H K; Leung, Dawn S S; Holmes, Andrew D

    2007-09-01

    The balance function of children is known to be affected by carriage of a school backpack. Children with adolescent idiopathic scoliosis (AIS) tend to show poorer balance performance, and are typically treated by bracing, which further affects balance. The objective of this study is to examine the combined effects of school backpack carriage and bracing on girls with AIS. A force platform was used to record center of pressure (COP) motion in 20 schoolgirls undergoing thoraco-lumbar-sacral orthosis (TLSO brace) treatment for AIS. COP data were recorded with and without brace while carrying a backpack loaded at 0, 7.5, 10, 12.5 and 15% of the participant's bodyweight (BW). Ten participants stood on a solid base and ten stood on a foam base, while all participants kept their eyes closed throughout. Sway parameters were analyzed by repeated measures ANOVA. No effect of bracing was found for the participants standing on the solid base, but wearing the brace significantly increased the sway area, displacement and medio-lateral amplitude in the participants standing on the foam base. The medio-lateral sway amplitude of participants standing on the solid base significantly increased with backpack load, whereas significant increases in antero-posterior sway amplitude, sway path length, sway area per second and short term diffusion coefficient were found in participants standing on the foam base. The poorer balance performance exhibited by participants with AIS when visual and somatosensory input is challenged appears to be exacerbated by wearing a TLSO brace, but no interactive effect between bracing and backpack loading was found.

  1. Review: Balancing Limiting Factors and Economic Drivers to Achieve Sustainable Midwestern US Agricultural Residue Feedstock Supplies

    SciTech Connect

    Wally W. Wilhelm; J. Richard Hess; Douglas L. Karlen; David J. Muth; Jane M. F. Johnson; John M. Baker; Hero T. Gollany; Jeff M. Novak; Diane E. Stott; Gary E. Varvel

    2010-10-01

    Advanced biofuels will be developed using cellulosic feedstock rather than grain or oilseed crops that can also be used for food and feed. To be sustainable, these new agronomic production systems must be economically viable without degrading soil resources. This review examines six agronomic factors that collectively define many of the limits and opportunities for harvesting crop residue for biofuel feedstock. These six “limiting factors” are discussed in relationship to economic drivers associated with harvesting corn (Zea mays L.) stover as a potential cellulosic feedstock. The limiting factors include soil organic carbon, wind and water erosion, plant nutrient balance, soil water and temperature dynamics, soil compaction, and off-site environmental impacts. Initial evaluations using the Revised Universal Soil Loss Equation 2.0 (RUSLE2) show that a single factor analysis based on simply meeting tolerable soil loss might indicate stover could be harvested sustainably, but the same analysis based on maintaining soil organic carbon shows the practice to be non-sustainable. Modifying agricultural management to include either annual or perennial cover crops is shown to meet both soil erosion and soil carbon requirements. The importance of achieving high yields and planning in a holistic manner at the landscape scale are also shown to be crucial for balancing limitations and drivers associated with renewable bioenergy production.

  2. Load Balancing in Cloud Computing Environment Using Improved Weighted Round Robin Algorithm for Nonpreemptive Dependent Tasks.

    PubMed

    Devi, D Chitra; Uthariaraj, V Rhymend

    2016-01-01

    Cloud computing uses the concepts of scheduling and load balancing to migrate tasks to underutilized VMs for effectively sharing the resources. The scheduling of the nonpreemptive tasks in the cloud computing environment is an irrecoverable restraint and hence it has to be assigned to the most appropriate VMs at the initial placement itself. Practically, the arrived jobs consist of multiple interdependent tasks and they may execute the independent tasks in multiple VMs or in the same VM's multiple cores. Also, the jobs arrive during the run time of the server in varying random intervals under various load conditions. The participating heterogeneous resources are managed by allocating the tasks to appropriate resources by static or dynamic scheduling to make the cloud computing more efficient and thus it improves the user satisfaction. Objective of this work is to introduce and evaluate the proposed scheduling and load balancing algorithm by considering the capabilities of each virtual machine (VM), the task length of each requested job, and the interdependency of multiple tasks. Performance of the proposed algorithm is studied by comparing with the existing methods.

  3. Load Balancing in Cloud Computing Environment Using Improved Weighted Round Robin Algorithm for Nonpreemptive Dependent Tasks

    PubMed Central

    Devi, D. Chitra; Uthariaraj, V. Rhymend

    2016-01-01

    Cloud computing uses the concepts of scheduling and load balancing to migrate tasks to underutilized VMs for effectively sharing the resources. The scheduling of the nonpreemptive tasks in the cloud computing environment is an irrecoverable restraint and hence it has to be assigned to the most appropriate VMs at the initial placement itself. Practically, the arrived jobs consist of multiple interdependent tasks and they may execute the independent tasks in multiple VMs or in the same VM's multiple cores. Also, the jobs arrive during the run time of the server in varying random intervals under various load conditions. The participating heterogeneous resources are managed by allocating the tasks to appropriate resources by static or dynamic scheduling to make the cloud computing more efficient and thus it improves the user satisfaction. Objective of this work is to introduce and evaluate the proposed scheduling and load balancing algorithm by considering the capabilities of each virtual machine (VM), the task length of each requested job, and the interdependency of multiple tasks. Performance of the proposed algorithm is studied by comparing with the existing methods. PMID:26955656

  4. A Multiconstrained Grid Scheduling Algorithm with Load Balancing and Fault Tolerance.

    PubMed

    Keerthika, P; Suresh, P

    2015-01-01

    Grid environment consists of millions of dynamic and heterogeneous resources. A grid environment which deals with computing resources is computational grid and is meant for applications that involve larger computations. A scheduling algorithm is said to be efficient if and only if it performs better resource allocation even in case of resource failure. Allocation of resources is a tedious issue since it has to consider several requirements such as system load, processing cost and time, user's deadline, and resource failure. This work attempts to design a resource allocation algorithm which is budget constrained and also targets load balancing, fault tolerance, and user satisfaction by considering the above requirements. The proposed Multiconstrained Load Balancing Fault Tolerant algorithm (MLFT) reduces the schedule makespan, schedule cost, and task failure rate and improves resource utilization. The proposed MLFT algorithm is evaluated using Gridsim toolkit and the results are compared with the recent algorithms which separately concentrate on all these factors. The comparison results ensure that the proposed algorithm works better than its counterparts.

  5. A low overhead load balancing router for network-on-chip

    NASA Astrophysics Data System (ADS)

    Xiaofeng, Zhou; Lu, Liu; Zhangming, Zhu; Duan, Zhou

    2016-11-01

    The design of a router in a network-on-chip (NoC) system has an important impact on some performance criteria. In this paper, we propose a low overhead load balancing router (LOLBR) for 2D mesh NoC to enhance routing performance criteria with low hardware overhead. The proposed LOLBR employs a balance toggle identifier to control the initial routing direction of X or Y for flit injection. The simplified demultiplexers and multiplexers are used to handle output ports allocation and contention, which provide a guarantee of deadlock avoidance. Simulation results show that the proposed LOLBR yields an improvement of routing performance over the reported routing schemes in average packet latency by 26.5%. The layout area and power consumption of the network compared with the reported routing schemes are 15.3% and 11.6% less respectively. Project supported by the National Natural Science Foundation of China (Nos. 61474087, 61322405, 61376039).

  6. A High Performance Load Balance Strategy for Real-Time Multicore Systems

    PubMed Central

    Cho, Keng-Mao; Tsai, Chun-Wei; Chiu, Yi-Shiuan; Yang, Chu-Sing

    2014-01-01

    Finding ways to distribute workloads to each processor core and efficiently reduce power consumption is of vital importance, especially for real-time systems. In this paper, a novel scheduling algorithm is proposed for real-time multicore systems to balance the computation loads and save power. The developed algorithm simultaneously considers multiple criteria, a novel factor, and task deadline, and is called power and deadline-aware multicore scheduling (PDAMS). Experiment results show that the proposed algorithm can greatly reduce energy consumption by up to 54.2% and the deadline times missed, as compared to the other scheduling algorithms outlined in this paper. PMID:24955382

  7. Balancing Power Absorption and Fatigue Loads in Irregular Waves for an Oscillating Surge Wave Energy Converter

    SciTech Connect

    Tom, Nathan M.; Yu, Yi-Hsiang; Wright, Alan D.; Lawson, Michael

    2016-06-24

    The aim of this paper is to describe how to control the power-to-load ratio of a novel wave energy converter (WEC) in irregular waves. The novel WEC that is being developed at the National Renewable Energy Laboratory combines an oscillating surge wave energy converter (OSWEC) with control surfaces as part of the structure; however, this work only considers one fixed geometric configuration. This work extends the optimal control problem so as to not solely maximize the time-averaged power, but to also consider the power-take-off (PTO) torque and foundation forces that arise because of WEC motion. The objective function of the controller will include competing terms that force the controller to balance power capture with structural loading. Separate penalty weights were placed on the surge-foundation force and PTO torque magnitude, which allows the controller to be tuned to emphasize either power absorption or load shedding. Results of this study found that, with proper selection of penalty weights, gains in time-averaged power would exceed the gains in structural loading while minimizing the reactive power requirement.

  8. Sensor Deployment for Geographic, Load Balanced Hierarchical Organization in Wireless Sensor Networks

    NASA Astrophysics Data System (ADS)

    Gautam, Amit Kr.; Gautam, Ajay Kr.; Patel, R. B.

    2010-11-01

    In order to provide load balancing in clustered sensor deployment, the upstream clusters (near the BS) are kept smaller in size as compared to downstream ones (away from BS). Moreover, geographic awareness is also desirable in order to further enhance energy efficiency. But, this must be cost effective, since most of current location awareness strategies are either cost and weight inefficient (GPS) or are complex, inaccurate and unreliable in operation. This paper presents design and implementation of a Geographic LOad BALanced (GLOBAL) Clustering Protocol for Wireless Sensor Networks. A mathematical formulation is provided for determining the number of sensor nodes in each cluster. This enables uniform energy consumption after the multi-hop data transmission towards BS. Either the sensors can be manually deployed or the clusters be so formed that the sensor are efficiently distributed as per formulation. The latter strategy is elaborated in this contribution. Methods to provide static clustering and custom cluster sizes with location awareness are also provided in the given work. Finally, low mobility node applications can also implement the proposed work.

  9. A De-centralized Scheduling and Load Balancing Algorithm for Heterogeneous Grid Environments

    NASA Technical Reports Server (NTRS)

    Arora, Manish; Das, Sajal K.; Biswas, Rupak

    2002-01-01

    In the past two decades, numerous scheduling and load balancing techniques have been proposed for locally distributed multiprocessor systems. However, they all suffer from significant deficiencies when extended to a Grid environment: some use a centralized approach that renders the algorithm unscalable, while others assume the overhead involved in searching for appropriate resources to be negligible. Furthermore, classical scheduling algorithms do not consider a Grid node to be N-resource rich and merely work towards maximizing the utilization of one of the resources. In this paper, we propose a new scheduling and load balancing algorithm for a generalized Grid model of N-resource nodes that not only takes into account the node and network heterogeneity, but also considers the overhead involved in coordinating among the nodes. Our algorithm is decentralized, scalable, and overlaps the node coordination time with that of the actual processing of ready jobs, thus saving valuable clock cycles needed for making decisions. The proposed algorithm is studied by conducting simulations using the Message Passing Interface (MPI) paradigm.

  10. A De-Centralized Scheduling and Load Balancing Algorithm for Heterogeneous Grid Environments

    NASA Technical Reports Server (NTRS)

    Arora, Manish; Das, Sajal K.; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2002-01-01

    In the past two decades, numerous scheduling and load balancing techniques have been proposed for locally distributed multiprocessor systems. However, they all suffer from significant deficiencies when extended to a Grid environment: some use a centralized approach that renders the algorithm unscalable, while others assume the overhead involved in searching for appropriate resources to be negligible. Furthermore, classical scheduling algorithms do not consider a Grid node to be N-resource rich and merely work towards maximizing the utilization of one of the resources. In this paper we propose a new scheduling and load balancing algorithm for a generalized Grid model of N-resource nodes that not only takes into account the node and network heterogeneity, but also considers the overhead involved in coordinating among the nodes. Our algorithm is de-centralized, scalable, and overlaps the node coordination time of the actual processing of ready jobs, thus saving valuable clock cycles needed for making decisions. The proposed algorithm is studied by conducting simulations using the Message Passing Interface (MPI) paradigm.

  11. GRACOS: Scalable and Load Balanced P3M Cosmological N-body Code

    NASA Astrophysics Data System (ADS)

    Shirokov, Alexander; Bertschinger, Edmund

    2010-10-01

    The GRACOS (GRAvitational COSmology) code, a parallel implementation of the particle-particle/particle-mesh (P3M) algorithm for distributed memory clusters, uses a hybrid method for both computation and domain decomposition. Long-range forces are computed using a Fourier transform gravity solver on a regular mesh; the mesh is distributed across parallel processes using a static one-dimensional slab domain decomposition. Short-range forces are computed by direct summation of close pairs; particles are distributed using a dynamic domain decomposition based on a space-filling Hilbert curve. A nearly-optimal method was devised to dynamically repartition the particle distribution so as to maintain load balance even for extremely inhomogeneous mass distributions. Tests using 800(3) simulations on a 40-processor beowulf cluster showed good load balance and scalability up to 80 processes. There are limits on scalability imposed by communication and extreme clustering which may be removed by extending the algorithm to include adaptive mesh refinement.

  12. A Universal Threshold for the Assessment of Load and Output Residuals of Strain-Gage Balance Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Volden, T.

    2017-01-01

    A new universal residual threshold for the detection of load and gage output residual outliers of wind tunnel strain{gage balance data was developed. The threshold works with both the Iterative and Non{Iterative Methods that are used in the aerospace testing community to analyze and process balance data. It also supports all known load and gage output formats that are traditionally used to describe balance data. The threshold's definition is based on an empirical electrical constant. First, the constant is used to construct a threshold for the assessment of gage output residuals. Then, the related threshold for the assessment of load residuals is obtained by multiplying the empirical electrical constant with the sum of the absolute values of all first partial derivatives of a given load component. The empirical constant equals 2.5 microV/V for the assessment of balance calibration or check load data residuals. A value of 0.5 microV/V is recommended for the evaluation of repeat point residuals because, by design, the calculation of these residuals removes errors that are associated with the regression analysis of the data itself. Data from a calibration of a six-component force balance is used to illustrate the application of the new threshold definitions to real{world balance calibration data.

  13. Learning anatomy via mobile augmented reality: Effects on achievement and cognitive load.

    PubMed

    Küçük, Sevda; Kapakin, Samet; Göktaş, Yüksel

    2016-10-01

    Augmented reality (AR), a new generation of technology, has attracted the attention of educators in recent years. In this study, a MagicBook was developed for a neuroanatomy topic by using mobile augmented reality (mAR) technology. This technology integrates virtual learning objects into the real world and allow users to interact with the environment using mobile devices. The purpose of this study was to determine the effects of learning anatomy via mAR on medical students' academic achievement and cognitive load. The mixed method was applied in the study. The random sample consisted of 70 second-year undergraduate medical students: 34 in an experimental group and 36 in a control group. Academic achievement test and cognitive load scale were used as data collection tool. A one-way MANOVA test was used for analysis. The experimental group, which used mAR applications, reported higher achievement and lower cognitive load. The use of mAR applications in anatomy education contributed to the formation of an effective and productive learning environment. Student cognitive load decreased as abstract information became concrete in printed books via multimedia materials in mAR applications. Additionally, students were able to access the materials in the MagicBook anytime and anywhere they wanted. The mobile learning approach helped students learn better by exerting less cognitive effort. Moreover, the sensory experience and real time interaction with environment may provide learning satisfaction and enable students to structure their knowledge to complete the learning tasks. Anat Sci Educ 9: 411-421. © 2016 American Association of Anatomists.

  14. A New Load Residual Threshold Definition for the Evaluation of Wind Tunnel Strain-Gage Balance Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Volden, T.

    2016-01-01

    A new definition of a threshold for the detection of load residual outliers of wind tunnel strain-gage balance data was developed. The new threshold is defined as the product between the inverse of the absolute value of the primary gage sensitivity and an empirical limit of the electrical outputs of a strain{gage. The empirical limit of the outputs is either 2.5 microV/V for balance calibration or check load residuals. A reduced limit of 0.5 microV/V is recommended for the evaluation of differences between repeat load points because, by design, the calculation of these differences removes errors in the residuals that are associated with the regression analysis of the data itself. The definition of the new threshold and different methods for the determination of the primary gage sensitivity are discussed. In addition, calibration data of a six-component force balance and a five-component semi-span balance are used to illustrate the application of the proposed new threshold definition to different types of strain{gage balances. During the discussion of the force balance example it is also explained how the estimated maximum expected output of a balance gage can be used to better understand results of the application of the new threshold definition.

  15. Modified surface loading process for achieving improved performance of the quantum dot-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Liu, Feng; Jin, Zhongxiu; Zhu, Jun; Xu, Yafeng; Zhou, Li; Dai, Songyuan

    2016-06-01

    Achieving high surface coverage of the colloidal quantum dots (QDs) on TiO2 films has been challenging for quantum dot-sensitized solar cells (QDSCs). Herein, a general surface engineering approach was proposed to increase the loading of these QDs. It was found that S2- treatment/QD re-uptake process can significantly improve the attachment of the QDs on TiO2 films. Surface concentration of the QDs was improved by ∼60%, which in turn greatly enhances light absorption and decreases carrier recombination in QDSCs. Ensuing QDSCs with optimized QD loading exhibit a power conversion efficiency of 3.66%, 83% higher than those fabricated with standard procedures.

  16. Uncertainty analysis on simple mass balance model to calculate critical loads for soil acidity.

    PubMed

    Li, Harbin; McNulty, Steven G

    2007-10-01

    Simple mass balance equations (SMBE) of critical acid loads (CAL) in forest soil were developed to assess potential risks of air pollutants to ecosystems. However, to apply SMBE reliably at large scales, SMBE must be tested for adequacy and uncertainty. Our goal was to provide a detailed analysis of uncertainty in SMBE so that sound strategies for scaling up CAL estimates to the national scale could be developed. Specifically, we wanted to quantify CAL uncertainty under natural variability in 17 model parameters, and determine their relative contributions in predicting CAL. Results indicated that uncertainty in CAL came primarily from components of base cation weathering (BC(w); 49%) and acid neutralizing capacity (46%), whereas the most critical parameters were BC(w) base rate (62%), soil depth (20%), and soil temperature (11%). Thus, improvements in estimates of these factors are crucial to reducing uncertainty and successfully scaling up SMBE for national assessments of CAL.

  17. PARALLEL IMPLEMENTATION OF THE TOPAZ OPACITY CODE: ISSUES IN LOAD-BALANCING

    SciTech Connect

    Sonnad, V; Iglesias, C A

    2008-05-12

    The TOPAZ opacity code explicitly includes configuration term structure in the calculation of bound-bound radiative transitions. This approach involves myriad spectral lines and requires the large computational capabilities of parallel processing computers. It is important, however, to make use of these resources efficiently. For example, an increase in the number of processors should yield a comparable reduction in computational time. This proportional 'speedup' indicates that very large problems can be addressed with massively parallel computers. Opacity codes can readily take advantage of parallel architecture since many intermediate calculations are independent. On the other hand, since the different tasks entail significantly disparate computational effort, load-balancing issues emerge so that parallel efficiency does not occur naturally. Several schemes to distribute the labor among processors are discussed.

  18. Dynamic load balancing in a concurrent plasma PIC code on the JPL/Caltech Mark III hypercube

    SciTech Connect

    Liewer, P.C.; Leaver, E.W.; Decyk, V.K.; Dawson, J.M.

    1990-12-31

    Dynamic load balancing has been implemented in a concurrent one-dimensional electromagnetic plasma particle-in-cell (PIC) simulation code using a method which adds very little overhead to the parallel code. In PIC codes, the orbits of many interacting plasma electrons and ions are followed as an initial value problem as the particles move in electromagnetic fields calculated self-consistently from the particle motions. The code was implemented using the GCPIC algorithm in which the particles are divided among processors by partitioning the spatial domain of the simulation. The problem is load-balanced by partitioning the spatial domain so that each partition has approximately the same number of particles. During the simulation, the partitions are dynamically recreated as the spatial distribution of the particles changes in order to maintain processor load balance.

  19. Tuning charge balance in PHOLEDs with ambipolar host materials to achieve high efficiency

    SciTech Connect

    Padmaperuma, Asanga B.; Koech, Phillip K.; Cosimbescu, Lelia; Polikarpov, Evgueni; Swensen, James S.; Chopra, Neetu; So, Franky; Sapochak, Linda S.; Gaspar, Daniel J.

    2009-08-27

    operating voltages, particularly if this is to be achieved in a device that can be manufactured at low cost. To avoid the efficiency losses associated with phosphorescence quenching by back-energy transfer from the dopant onto the host, the triplet excited states of the host material must be higher in energy than the triplet excited state of the dopant.5 This must be accomplished without sacrificing the charge transporting properties of the composite.6 Similar problems limit the efficiency of OLED-based displays, where blue light emitters are the least efficient and least stable. We previously demonstrated the utility of organic phosphine oxide (PO) materials as electron transporting HMs for FIrpic in blue OLEDs.7 However, the high reluctance of PO materials to oxidation and thus, hole injection limits the ability to balance charge injection and transport in the EML without relying on charge transport by the phosphorescent dopant. PO host materials were engineered to transport both electrons and holes in the EML and still maintain high triplet exciton energy to ensure efficient energy transfer to the dopant (Figure 1). There are examples of combining hole transporting moieties (mainly aromatic amines) with electron transport moieties (e.g., oxadiazoles, triazines, boranes)8 to develop new emitter and host materials for small molecule and polymer9 OLEDs. The challenge is to combine the two moieties without lowering the triplet energy of the target molecule. For example, coupling of a dimesitylphenylboryl moiety with a tertiary aromatic amine (FIAMBOT) results in intramolecular electron transfer from the amine to the boron atom through the bridging phenyl. The mesomeric effect of the dimesitylphenylboryl unit acts to extend conjugation and lowers triplet exciton energies (< 2.8 eV) rendering such systems inadequate as ambipolar hosts for blue phosphors.

  20. Achieving Accurate Ligament Balancing Using Robotic-Assisted Unicompartmental Knee Arthroplasty

    PubMed Central

    Plate, Johannes F.; Mofidi, Ali; Mannava, Sandeep; Smith, Beth P.; Lang, Jason E.; Poehling, Gary G.; Conditt, Michael A.; Jinnah, Riyaz H.

    2013-01-01

    Unicompartmental knee arthroplasty (UKA) allows replacement of a single compartment in patients with limited disease. However, UKA is technically challenging and relies on accurate component positioning and restoration of natural knee kinematics. This study examined the accuracy of dynamic, real-time ligament balancing using a robotic-assisted UKA system. Surgical data obtained from the computer system were prospectively collected from 51 patients (52 knees) undergoing robotic-assisted medial UKA by a single surgeon. Dynamic ligament balancing of the knee was obtained under valgus stress prior to component implantation and then compared to final ligament balance with the components in place. Ligament balancing was accurate up to 0.53 mm compared to the preoperative plan, with 83% of cases within 1 mm at 0°, 30°, 60°, 90°, and 110° of flexion. Ligamentous laxity of 1.31 ± 0.13 mm at 30° of flexion was corrected successfully to 0.78 ± 0.17 mm (P < 0.05). Robotic-assisted UKA allows accurate and precise reproduction of a surgical balance plan using dynamic, real-time soft-tissue balancing to help restore natural knee kinematics, potentially improving implant survival and functional outcomes. PMID:23634304

  1. Balancing rotor speed regulation and drive train loads of floating wind turbines

    NASA Astrophysics Data System (ADS)

    Fischer, Boris; Loepelmann, Peter

    2016-09-01

    The interaction of the blade pitch controller with structural motion is particularly important for wind turbines mounted on floating platforms. A controls-based approach to overcome the related technical challenges is to feed back the nacelle's motion to the demanded generator torque. This work aims to further improve this approach by feeding back only a narrow fraction of the available frequency range. Simulations show that, in doing so, unrealistically high torque magnitudes are avoided, and better a trade-off between rotor speed regulation and drive train loads is achieved.

  2. Utilizing hydropower for load balancing non-storable renewable energy sources - technical and environmental challenges

    NASA Astrophysics Data System (ADS)

    Alfredsen, K. T.; Killingtveit, A.

    2011-12-01

    About 99% of the total energy production in Norway comes from hydropower, and the total production of about 120 TWh makes Norway Europe's largest hydropower producer. Most hydropower systems in Norway are based on high-head plants with mountain storage reservoirs and tunnels transporting water from the reservoirs to the power plants. In total, Norwegian reservoirs contributes around 50% of the total energy storage capacity in Europe. Current strategies to reduce emission of greenhouse gases from energy production involve increased focus on renewable energy sources, e.g. the European Union's 202020 goal in which renewable energy sources should be 20% of the total energy production by 2020. To meet this goal new renewable energy installations must be developed on a large scale in the coming years, and wind power is the main focus for new developments. Hydropower can contribute directly to increase renewable energy through new development or extensions to existing systems, but maybe even more important is the potential to use hydropower systems with storage for load balancing in a system with increased amount of non-storable renewable energies. Even if new storage technologies are under development, hydro storage is the only technology available on a large scale and the most economical feasible alternative. In this respect the Norwegian system has a high potential both through direct use of existing reservoirs and through an increased development of pump storage plants utilizing surplus wind energy to pump water and then producing during periods with low wind input. Through cables to Europe, Norwegian hydropower could also provide balance power for the North European market. Increased peaking and more variable operation of the current hydropower system will present a number of technical and environmental challenges that needs to be identified and mitigated. A more variable production will lead to fluctuating flow in receiving rivers and reservoirs, and it will also

  3. Food composition and acid-base balance: alimentary alkali depletion and acid load in herbivores.

    PubMed

    Kiwull-Schöne, Heidrun; Kiwull, Peter; Manz, Friedrich; Kalhoff, Hermann

    2008-02-01

    Alkali-enriched diets are recommended for humans to diminish the net acid load of their usual diet. In contrast, herbivores have to deal with a high dietary alkali impact on acid-base balance. Here we explore the role of nutritional alkali in experimentally induced chronic metabolic acidosis. Data were collected from healthy male adult rabbits kept in metabolism cages to obtain 24-h urine and arterial blood samples. Randomized groups consumed rabbit diets ad libitum, providing sufficient energy but variable alkali load. One subgroup (n = 10) received high-alkali food and approximately 15 mEq/kg ammonium chloride (NH4Cl) with its drinking water for 5 d. Another group (n = 14) was fed low-alkali food for 5 d and given approximately 4 mEq/kg NH4Cl daily for the last 2 d. The wide range of alimentary acid-base load was significantly reflected by renal base excretion, but normal acid-base conditions were maintained in the arterial blood. In rabbits fed a high-alkali diet, the excreted alkaline urine (pH(u) > 8.0) typically contained a large amount of precipitated carbonate, whereas in rabbits fed a low-alkali diet, both pH(u) and precipitate decreased considerably. During high-alkali feeding, application of NH4Cl likewise decreased pH(u), but arterial pH was still maintained with no indication of metabolic acidosis. During low-alkali feeding, a comparably small amount of added NH4Cl further lowered pH(u) and was accompanied by a significant systemic metabolic acidosis. We conclude that exhausted renal base-saving function by dietary alkali depletion is a prerequisite for growing susceptibility to NH4Cl-induced chronic metabolic acidosis in the herbivore rabbit.

  4. Description and development of the means of a model experiment for load balancing in distributed computing systems

    NASA Astrophysics Data System (ADS)

    Nagiyev, A. E.; Sherstnyova, A. I.; Botygin, I. A.; Galanova, N. Y.

    2016-06-01

    The results of the statistical model experiments research of various load balancing algorithms in distributed computing systems are presented. Software tools were developed. These tools, which allow to create a virtual infrastructure of distributed computing system in accordance with the intended objective of the research focused on multi-agent and multithreaded data processing were developed. A diagram of the control processing of requests from the terminal devices, providing an effective dynamic horizontal scaling of computing power at peak loads, is proposed.

  5. Improved Student Achievement Using Personalized Online Homework for a Course in Material and Energy Balances

    ERIC Educational Resources Information Center

    Liberatore, Matthew W.

    2011-01-01

    Personalized, online homework was used to supplement textbook homework, quizzes, and exams for one section of a course in material and energy balances. The objective of this study was to test the hypothesis that students using personalized, online homework earned better grades in the course. The online homework system asks the same questions of…

  6. Parallel implementation of the particle simulation method with dynamic load balancing: Toward realistic geodynamical simulation

    NASA Astrophysics Data System (ADS)

    Furuichi, M.; Nishiura, D.

    2015-12-01

    Fully Lagrangian methods such as Smoothed Particle Hydrodynamics (SPH) and Discrete Element Method (DEM) have been widely used to solve the continuum and particles motions in the computational geodynamics field. These mesh-free methods are suitable for the problems with the complex geometry and boundary. In addition, their Lagrangian nature allows non-diffusive advection useful for tracking history dependent properties (e.g. rheology) of the material. These potential advantages over the mesh-based methods offer effective numerical applications to the geophysical flow and tectonic processes, which are for example, tsunami with free surface and floating body, magma intrusion with fracture of rock, and shear zone pattern generation of granular deformation. In order to investigate such geodynamical problems with the particle based methods, over millions to billion particles are required for the realistic simulation. Parallel computing is therefore important for handling such huge computational cost. An efficient parallel implementation of SPH and DEM methods is however known to be difficult especially for the distributed-memory architecture. Lagrangian methods inherently show workload imbalance problem for parallelization with the fixed domain in space, because particles move around and workloads change during the simulation. Therefore dynamic load balance is key technique to perform the large scale SPH and DEM simulation. In this work, we present the parallel implementation technique of SPH and DEM method utilizing dynamic load balancing algorithms toward the high resolution simulation over large domain using the massively parallel super computer system. Our method utilizes the imbalances of the executed time of each MPI process as the nonlinear term of parallel domain decomposition and minimizes them with the Newton like iteration method. In order to perform flexible domain decomposition in space, the slice-grid algorithm is used. Numerical tests show that our

  7. Load-balancing techniques for a parallel electromagnetic particle-in-cell code

    SciTech Connect

    PLIMPTON,STEVEN J.; SEIDEL,DAVID B.; PASIK,MICHAEL F.; COATS,REBECCA S.

    2000-01-01

    QUICKSILVER is a 3-d electromagnetic particle-in-cell simulation code developed and used at Sandia to model relativistic charged particle transport. It models the time-response of electromagnetic fields and low-density-plasmas in a self-consistent manner: the fields push the plasma particles and the plasma current modifies the fields. Through an LDRD project a new parallel version of QUICKSILVER was created to enable large-scale plasma simulations to be run on massively-parallel distributed-memory supercomputers with thousands of processors, such as the Intel Tflops and DEC CPlant machines at Sandia. The new parallel code implements nearly all the features of the original serial QUICKSILVER and can be run on any platform which supports the message-passing interface (MPI) standard as well as on single-processor workstations. This report describes basic strategies useful for parallelizing and load-balancing particle-in-cell codes, outlines the parallel algorithms used in this implementation, and provides a summary of the modifications made to QUICKSILVER. It also highlights a series of benchmark simulations which have been run with the new code that illustrate its performance and parallel efficiency. These calculations have up to a billion grid cells and particles and were run on thousands of processors. This report also serves as a user manual for people wishing to run parallel QUICKSILVER.

  8. Distributed Parallel Processing and Dynamic Load Balancing Techniques for Multidisciplinary High Speed Aircraft Design

    NASA Technical Reports Server (NTRS)

    Krasteva, Denitza T.

    1998-01-01

    Multidisciplinary design optimization (MDO) for large-scale engineering problems poses many challenges (e.g., the design of an efficient concurrent paradigm for global optimization based on disciplinary analyses, expensive computations over vast data sets, etc.) This work focuses on the application of distributed schemes for massively parallel architectures to MDO problems, as a tool for reducing computation time and solving larger problems. The specific problem considered here is configuration optimization of a high speed civil transport (HSCT), and the efficient parallelization of the embedded paradigm for reasonable design space identification. Two distributed dynamic load balancing techniques (random polling and global round robin with message combining) and two necessary termination detection schemes (global task count and token passing) were implemented and evaluated in terms of effectiveness and scalability to large problem sizes and a thousand processors. The effect of certain parameters on execution time was also inspected. Empirical results demonstrated stable performance and effectiveness for all schemes, and the parametric study showed that the selected algorithmic parameters have a negligible effect on performance.

  9. STAR load balancing and tiered-storage infrastructure strategy for ultimate db access

    NASA Astrophysics Data System (ADS)

    Arkhipkin, D.; Lauret, J.; Betts, W.; Didenko, L.; Van Buren, G.

    2011-12-01

    In recent years, the STAR experiment's database demands have grown in accord not only with simple facility growth, but also with a growing physics program. In addition to the accumulated metadata from a decade of operations, refinements to detector calibrations force user analysis to access database information post data production. Users may access any year's data at any point in time, causing a near random access of the metadata queried, contrary to time-organized production cycles. Moreover, complex online event selection algorithms created a query scarcity ("sparsity") scenario for offline production further impacting performance. Fundamental changes in our hardware approach were hence necessary to improve query speed. Initial strategic improvements were focused on developing fault-tolerant, load-balanced access to a multi-slave infrastructure. Beyond that, we explored, tested and quantified the benefits of introducing a Tiered storage architecture composed of conventional drives, solid-state disks, and memory-resident databases as well as leveraging the use of smaller database services fitting in memory. The results of our extensive testing in real life usage are presented.

  10. The Plasma Simulation Code: A modern particle-in-cell code with patch-based load-balancing

    NASA Astrophysics Data System (ADS)

    Germaschewski, Kai; Fox, William; Abbott, Stephen; Ahmadi, Narges; Maynard, Kristofor; Wang, Liang; Ruhl, Hartmut; Bhattacharjee, Amitava

    2016-08-01

    This work describes the Plasma Simulation Code (PSC), an explicit, electromagnetic particle-in-cell code with support for different order particle shape functions. We review the basic components of the particle-in-cell method as well as the computational architecture of the PSC code that allows support for modular algorithms and data structure in the code. We then describe and analyze in detail a distinguishing feature of PSC: patch-based load balancing using space-filling curves which is shown to lead to major efficiency gains over unbalanced methods and a previously used simpler balancing method.

  11. New mechanisms that regulate Saccharomyces cerevisiae short peptide transporter achieve balanced intracellular amino acid concentrations.

    PubMed

    Melnykov, Artem V

    2016-01-01

    The budding yeast Saccharomyces cerevisiae is able to take up large quantities of amino acids in the form of di- and tripeptides via a short peptide transporter, Ptr2p. It is known that PTR2 can be induced by certain peptides and amino acids, and the mechanisms governing this upregulation are understood at the molecular level. We describe two new opposing mechanisms of regulation that emphasize potential toxicity of amino acids: the first is upregulation of PTR2 in a population of cells, caused by amino acid secretion that accompanies peptide uptake; the second is loss of Ptr2p activity, due to transporter internalization following peptide uptake. Our findings emphasize the importance of proper amino acid balance in the cell and extend understanding of peptide import regulation in yeast.

  12. Study of regeneration system of 300 MW power unit based on nondeaerating heat balance diagram at reduced load

    NASA Astrophysics Data System (ADS)

    Esin, S. B.; Trifonov, N. N.; Sukhorukov, Yu. G.; Yurchenko, A. Yu.; Grigor'eva, E. B.; Snegin, I. P.; Zhivykh, D. A.; Medvedkin, A. V.; Ryabich, V. A.

    2015-09-01

    More than 30 power units of thermal power stations, based on the nondeaerating heat balance diagram, successfully operate in the former Soviet Union. Most of them are power units with a power of 300 MW, equipped with HTGZ and LMZ turbines. They operate according to a variable electric load curve characterized by deep reductions when undergoing night minimums. Additional extension of the range of power unit adjustment makes it possible to maintain the dispatch load curve and obtain profit for the electric power plant. The objective of this research is to carry out estimated and experimental processing of the operating regimes of the regeneration system of steam-turbine plants within the extended adjustment range and under the conditions when the constraints on the regeneration system and its equipment are removed. Constraints concerning the heat balance diagram that reduce the power unit efficiency when extending the adjustment range have been considered. Test results are presented for the nondeaerating heat balance diagram with the HTGZ turbine. Turbine pump and feed electric pump operation was studied at a power unit load of 120-300 MW. The reliability of feed pump operation is confirmed by a stable vibratory condition and the absence of cavitation noise and vibration at a frequency that characterizes the cavitation condition, as well as by oil temperature maintenance after bearings within normal limits. Cavitation performance of pumps in the studied range of their operation has been determined. Technical solutions are proposed on providing a profitable and stable operation of regeneration systems when extending the range of adjustment of power unit load. A nondeaerating diagram of high-pressure preheater (HPP) condensate discharge to the mixer. A regeneration system has been developed and studied on the operating power unit fitted with a deaeratorless thermal circuit of the system for removing the high-pressure preheater heating steam condensate to the mixer

  13. Parental Behavioural Control and Academic Achievement: Striking the Balance between Control and Involvement

    ERIC Educational Resources Information Center

    Kramer, Karen Z.

    2012-01-01

    Using a longitudinal US dataset (N = 6,134) we examine the relationship between parental behavioural control and academic achievement and explore the moderating role of parental involvement and parental warmth. Analyses using multiple hierarchical regression with clustering controls shows that parental behavioural control is negatively associated…

  14. Performance Evaluation of Counter-Based Dynamic Load Balancing Schemes for Massive Contingency Analysis with Different Computing Environments

    SciTech Connect

    Chen, Yousu; Huang, Zhenyu; Chavarría-Miranda, Daniel

    2010-09-30

    Contingency analysis is a key function in the Energy Management System (EMS) to assess the impact of various combinations of power system component failures based on state estimation. Contingency analysis is also extensively used in power market operation for feasibility test of market solutions. High performance computing holds the promise of faster analysis of more contingency cases for the purpose of safe and reliable operation of today’s power grids with less operating margin and more intermittent renewable energy sources. This paper evaluates the performance of counter-based dynamic load balancing schemes for massive contingency analysis under different computing environments. Insights from the performance evaluation can be used as guidance for users to select suitable schemes in the application of massive contingency analysis. Case studies, as well as MATLAB simulations, of massive contingency cases using the Western Electricity Coordinating Council power grid model are presented to illustrate the application of high performance computing with counter-based dynamic load balancing schemes.

  15. Isometric Scaling in Developing Long Bones Is Achieved by an Optimal Epiphyseal Growth Balance.

    PubMed

    Stern, Tomer; Aviram, Rona; Rot, Chagai; Galili, Tal; Sharir, Amnon; Kalish Achrai, Noga; Keller, Yosi; Shahar, Ron; Zelzer, Elazar

    2015-08-01

    One of the major challenges that developing organs face is scaling, that is, the adjustment of physical proportions during the massive increase in size. Although organ scaling is fundamental for development and function, little is known about the mechanisms that regulate it. Bone superstructures are projections that typically serve for tendon and ligament insertion or articulation and, therefore, their position along the bone is crucial for musculoskeletal functionality. As bones are rigid structures that elongate only from their ends, it is unclear how superstructure positions are regulated during growth to end up in the right locations. Here, we document the process of longitudinal scaling in developing mouse long bones and uncover the mechanism that regulates it. To that end, we performed a computational analysis of hundreds of three-dimensional micro-CT images, using a newly developed method for recovering the morphogenetic sequence of developing bones. Strikingly, analysis revealed that the relative position of all superstructures along the bone is highly preserved during more than a 5-fold increase in length, indicating isometric scaling. It has been suggested that during development, bone superstructures are continuously reconstructed and relocated along the shaft, a process known as drift. Surprisingly, our results showed that most superstructures did not drift at all. Instead, we identified a novel mechanism for bone scaling, whereby each bone exhibits a specific and unique balance between proximal and distal growth rates, which accurately maintains the relative position of its superstructures. Moreover, we show mathematically that this mechanism minimizes the cumulative drift of all superstructures, thereby optimizing the scaling process. Our study reveals a general mechanism for the scaling of developing bones. More broadly, these findings suggest an evolutionary mechanism that facilitates variability in bone morphology by controlling the activity of

  16. Curriculum reform and choice of science: Consequences for balanced and equitable participation and achievement

    NASA Astrophysics Data System (ADS)

    Rennie, Léonie J.; Parker, Lesley H.

    In 1988, most schools in Western Australia adopted a Unit Curriculum structure in the first three years of high school, following piloting of the scheme in seven schools in 1987. The goais of the Unit Curriculum are stated to be excellence, equity, and relevance, and one of its key features is the increased flexibility students have in making their subject selection. This article reviews the science enrollment and achievement patterns of males and females studying in the pilot schools in 1987, and for the first three years of the operation of the Unit Curriculum in 1988, 1989, and 1990. The data indicate that lowering the age for subject choice is associated with a reduction in the amount of science studies, especially by females, and with the early manifestation of sex-stereotyped subject selection. It appears that if early sex stereotyping is to be avoided, then students need to be provided with more structure in their selection of units. This article emphasizes the need for all involved in system-wide curriculum change to be fully informed of the potential benefits and dangers of curriculum models which allow wide flexibility, especially where curriculum change affects students' choice point.

  17. A question of balance: achieving appropriate nutrient levels in biofortified staple crops.

    PubMed

    Sanahuja, Georgina; Farré, Gemma; Berman, Judit; Zorrilla-López, Uxue; Twyman, Richard M; Capell, Teresa; Christou, Paul; Zhu, Changfu

    2013-12-01

    The biofortification of staple crops with vitamins is an attractive strategy to increase the nutritional quality of human food, particularly in areas where the population subsists on a cereal-based diet. Unlike other approaches, biofortification is sustainable and does not require anything more than a standard food-distribution infrastructure. The health-promoting effects of vitamins depend on overall intake and bioavailability, the latter influenced by food processing, absorption efficiency and the utilisation or retention of the vitamin in the body. The bioavailability of vitamins in nutritionally enriched foods should ideally be adjusted to achieve the dietary reference intake in a reasonable portion. Current vitamin biofortification programmes focus on the fat-soluble vitamins A and E, and the water-soluble vitamins C and B9 (folate), but the control of dosage and bioavailability has been largely overlooked. In the present review, we discuss the vitamin content of nutritionally enhanced foods developed by conventional breeding and genetic engineering, focusing on dosage and bioavailability. Although the biofortification of staple crops could potentially address micronutrient deficiency on a global scale, further research is required to develop effective strategies that match the bioavailability of vitamins to the requirements of the human diet.

  18. The influence of oral water load on energy expenditure and sympatho-vagal balance in obese and normal weight women

    PubMed Central

    Żak-Gołąb, Agnieszka; Rzemieniuk, Anna; Smętek, Joanna; Sordyl, Ryszard; Tyrka, Agata; Sosnowski, Maciej; Zahorska-Markiewicz, Barbara; Chudek, Jerzy; Olszanecka-Glinianowicz, Magdalena

    2012-01-01

    Introduction Oral water load may increase the energy expenditure (EE) by stimulation of sympathetic dependent thermogenesis. Thus, drinking of water may be helpful in weight reduction. The aim of the study is to assess the influence of water load on energy expenditure and sympathetic activity in obese and normal weight women. Material and methods Forty-five women were included. Energy expenditure was measured twice, in the morning and after oral water load, by the indirect calorimetric method. The heart rate variability parameters low frequency (LF), high frequency (HF), LF/HF index, standard deviation of normal RR intervals (SDNN) and root mean square difference among successive RR normal intervals (rMSSD) were used for the indirect assessment of the sympatho-vagal balance. Results Resting energy expenditure (REE) was significantly higher in obese than in normal weight women (1529 ±396 kcal/day vs. 1198 ±373 kcal/day; p = 0.02). In both study groups after water load EE increased significantly (by 20% and by 12%, corresponding to 8.6 kcal/h and 5.2 kcal/h respectively), while, LF/HF index increased simultaneously. The increase of energy expenditure (EE) did not exceed the energetic cost of water heating, from room to body temperature – 15 kcal/1000 ml. There was no correlation between changes of energy expenditure (EE) and heart rate variability (HRV) parameters. Conclusions The increase of EE induced by water load is mostly related to the heating of the consumed water to body temperature. The assessment of autonomic balance by means of standard HRV indices had been found insufficient for detection of actually operating mechanisms. PMID:23319974

  19. Adding concentrated solar power plants to wind farms to achieve a good utility electrical load match

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Texas has the greatest installed wind turbine capacity of any state in the United States, the percentage of wind capacity approaches 10% of the utilities capacity (in 2010 the total wind generated capacity in Texas was 8%). It is becomimg increasingly difficult for the utility to balance the elec...

  20. Balancing Power Absorption and Fatigue Loads in Irregular Waves for an Oscillating Surge Wave Energy Converter: Preprint

    SciTech Connect

    Tom, Nathan M.; Yu, Yi-Hsiang; Wright, Alan D.; Lawson, Michael

    2016-06-01

    The aim of this paper is to describe how to control the power-to-load ratio of a novel wave energy converter (WEC) in irregular waves. The novel WEC that is being developed at the National Renewable Energy Laboratory combines an oscillating surge wave energy converter (OSWEC) with control surfaces as part of the structure; however, this work only considers one fixed geometric configuration. This work extends the optimal control problem so as to not solely maximize the time-averaged power, but to also consider the power-take-off (PTO) torque and foundation forces that arise because of WEC motion. The objective function of the controller will include competing terms that force the controller to balance power capture with structural loading. Separate penalty weights were placed on the surge-foundation force and PTO torque magnitude, which allows the controller to be tuned to emphasize either power absorption or load shedding. Results of this study found that, with proper selection of penalty weights, gains in time-averaged power would exceed the gains in structural loading while minimizing the reactive power requirement.

  1. Two Dimensional Array Based Overlay Network for Balancing Load of Peer-to-Peer Live Video Streaming

    NASA Astrophysics Data System (ADS)

    Faruq Ibn Ibrahimy, Abdullah; Rafiqul, Islam Md; Anwar, Farhat; Ibn Ibrahimy, Muhammad

    2013-12-01

    The live video data is streaming usually in a tree-based overlay network or in a mesh-based overlay network. In case of departure of a peer with additional upload bandwidth, the overlay network becomes very vulnerable to churn. In this paper, a two dimensional array-based overlay network is proposed for streaming the live video stream data. As there is always a peer or a live video streaming server to upload the live video stream data, so the overlay network is very stable and very robust to churn. Peers are placed according to their upload and download bandwidth, which enhances the balance of load and performance. The overlay network utilizes the additional upload bandwidth of peers to minimize chunk delivery delay and to maximize balance of load. The procedure, which is used for distributing the additional upload bandwidth of the peers, distributes the additional upload bandwidth to the heterogeneous strength peers in a fair treat distribution approach and to the homogeneous strength peers in a uniform distribution approach. The proposed overlay network has been simulated by Qualnet from Scalable Network Technologies and results are presented in this paper.

  2. Achieving pH control in microalgal cultures through fed-batch addition of stoichiometrically-balanced growth media

    PubMed Central

    2013-01-01

    Background Lack of accounting for proton uptake and secretion has confounded interpretation of the stoichiometry of photosynthetic growth of algae. This is also problematic for achieving growth of microalgae to high cell concentrations which is necessary to improve productivity and the economic feasibility of commercial-scale chemical production systems. Since microalgae are capable of consuming both nitrate and ammonium, this represents an opportunity to balance culture pH based on a nitrogen feeding strategy that does not utilize gas-phase CO2 buffering. Stoichiometry suggests that approximately 36 weight%N-NH4+ (balance nitrogen as NO3-) would minimize the proton imbalance and permit high-density photoautotrophic growth as it does in higher plant tissue culture. However, algal media almost exclusively utilize nitrate, and ammonium is often viewed as ‘toxic’ to algae. Results The microalgae Chlorella vulgaris and Chlamydomonas reinhardtii exclusively utilize ammonium when both ammonium and nitrate are provided during growth on excess CO2. The resulting proton imbalance from preferential ammonium utilization causes the pH to drop too low to sustain further growth when ammonium was only 9% of the total nitrogen (0.027 gN-NH4+/L). However, providing smaller amounts of ammonium sequentially in the presence of nitrate maintained the pH of a Chlorella vulgaris culture for improved growth on 0.3 gN/L to 5 gDW/L under 5% CO2 gas-phase supplementation. Bioreactor pH dynamics are shown to be predictable based on simple nitrogen assimilation as long as there is sufficient CO2 availability. Conclusions This work provides both a media formulation and a feeding strategy with a focus on nitrogen metabolism and regulation to support high-density algal culture without buffering. The instability in culture pH that is observed in microalgal cultures in the absence of buffers can be overcome through alternating utilization of ammonium and nitrate. Despite the highly regulated

  3. Validation of net joint loads calculated by inverse dynamics in case of complex movements: application to balance recovery movements.

    PubMed

    Robert, T; Chèze, L; Dumas, R; Verriest, J-P

    2007-01-01

    The joint forces and moments driving the motion of a human subject are classically computed by an inverse dynamic calculation. However, even if this process is theoretically simple, many sources of errors may lead to huge inaccuracies in the results. Moreover, a direct comparison with in vivo measured loads or with "gold standard" values from literature is only possible for very specific studies. Therefore, assessing the inaccuracy of inverse dynamic results is not a trivial problem and a simple method is still required. This paper presents a simple method to evaluate both: (1) the consistency of the results obtained by inverse dynamics; (2) the influence of possible modifications in the inverse dynamic hypotheses. This technique concerns recursive calculation performed on full kinematic chains, and consists in evaluating the loads obtained by two different recursive strategies. It has been applied to complex 3D whole body movements of balance recovery. A recursive Newton-Euler procedure was used to compute the net joint loads. Two models were used to represent the subject bodies, considering or not the upper body as a unique rigid segment. The inertial parameters of the body segments were estimated from two different sets of scaling equations [De Leva, P., 1996. Adjustments to Zatsiorsky-Suleyanov's segment inertia parameters. Journal of Biomechanics 29, 1223-1230; Dumas, R., Chèze, L., Verriest, J.-P., 2006b. Adjustments to McConville et al. and Young et al. Body Segment Inertial Parameters. Journal of Biomechanics, in press]. Using this comparison technique, it has been shown that, for the balance recovery motions investigated: (1) the use of the scaling equations proposed by Dumas et al., instead of those proposed by De Leva, improves the consistency of the results (average relative influence up to 30% for the transversal moment); (2) the arm motions dynamically influence the recovery motion in a non negligible way (average relative influence up to 15% and 30

  4. Load balancing prediction method of cloud storage based on analytic hierarchy process and hybrid hierarchical genetic algorithm.

    PubMed

    Zhou, Xiuze; Lin, Fan; Yang, Lvqing; Nie, Jing; Tan, Qian; Zeng, Wenhua; Zhang, Nian

    2016-01-01

    With the continuous expansion of the cloud computing platform scale and rapid growth of users and applications, how to efficiently use system resources to improve the overall performance of cloud computing has become a crucial issue. To address this issue, this paper proposes a method that uses an analytic hierarchy process group decision (AHPGD) to evaluate the load state of server nodes. Training was carried out by using a hybrid hierarchical genetic algorithm (HHGA) for optimizing a radial basis function neural network (RBFNN). The AHPGD makes the aggregative indicator of virtual machines in cloud, and become input parameters of predicted RBFNN. Also, this paper proposes a new dynamic load balancing scheduling algorithm combined with a weighted round-robin algorithm, which uses the predictive periodical load value of nodes based on AHPPGD and RBFNN optimized by HHGA, then calculates the corresponding weight values of nodes and makes constant updates. Meanwhile, it keeps the advantages and avoids the shortcomings of static weighted round-robin algorithm.

  5. An investigation into the sensitivity of the atmospheric chlorine and bromine loading using a globally averaged mass balance model

    NASA Astrophysics Data System (ADS)

    Dowdell, David C.; Matthews, G. Peter; Wells, Ian

    Two globally averaged mass balance models have been developed to investigate the sensitivity and future level of atmospheric chlorine and bromine as a result of the emission of 14 chloro- and 3 bromo-carbons. The models use production, growth, lifetime and concentration data for each of the halocarbons and divide the production into one of eight uses, these being aerosol propellants, cleaning agents, blowing agents in open and closed cell foams, non-hermetic and hermetic refrigeration, fire retardants and a residual "other" category. Each use category has an associated emission profile which is built into the models to take into account the proportion of halocarbon retained in equipment for a characteristic period of time before its release. Under the Montreal Protocol 3 requirements, a peak chlorine loading of 3.8 ppb is attained in 1994, which does not reduce to 2.0 ppb (the approximate level of atmospheric chlorine when the ozone hole formed) until 2053. The peak bromine loading is 22 ppt, also in 1994, which decays to 12 ppt by the end of next century. The models have been used to (i) compare the effectiveness of Montreal Protocols 1, 2 and 3 in removing chlorine from the atmosphere, (ii) assess the influence of the delayed emission assumptions used in these models compared to immediate emission assumptions used in previous models, (iii) assess the relative effect on the chlorine loading of a tightening of the Montreal Protocol 3 restrictions, and (iv) calculate the influence of chlorine and bromine chemistry as well as the faster phase out of man-made methyl bromide on the bromine loading.

  6. Need for optimizing catalyst loading for achieving affordable microbial fuel cells.

    PubMed

    Singh, Inderjeet; Chandra, Amreesh

    2013-08-01

    Microbial fuel cell (MFC) technology is a promising technology for electricity production together with simultaneous water treatment. Catalysts play an important role in deciding the MFC performance. In most reports, effect of catalyst - both type and quantity is not optimized. In this paper, synthesis of nanorods of MnO2-catalyst particles for application in Pt-free MFCs is reported. The effect of catalyst loading i.e., weight ratio, with respect to conducting element and binder has been optimized by employing large number of combinations. Using simple theoretical model, it is shown that too high (or low) concentration of catalysts result in loss of MFC performance. The operation of MFC has been investigated using domestic wastewater as source of bio-waste for obtaining real world situation. Maximum power density of ∼61 mW/m(2) was obtained when weight ratio of catalyst and conducting species was 1:1. Suitable reasons are given to explain the outcomes.

  7. Exploring the Causal Impact of the McREL Balanced Leadership Program on Leadership, Principal Efficacy, Instructional Climate, Educator Turnover, and Student Achievement

    ERIC Educational Resources Information Center

    Jacob, Robin; Goddard, Roger; Kim, Minjung; Miller, Robert; Goddard, Yvonne

    2015-01-01

    This study uses a randomized design to assess the impact of the Balanced Leadership program on principal leadership, instructional climate, principal efficacy, staff turnover, and student achievement in a sample of rural northern Michigan schools. Participating principals report feeling more efficacious, using more effective leadership practices,…

  8. Effects of nutrient loading on the carbon balance of coastal wetland sediments

    USGS Publications Warehouse

    Morris, J.T.; Bradley, P.M.

    1999-01-01

    Results of a 12-yr study in an oligotrophic South Carolina salt marsh demonstrate that soil respiration increased by 795 g C m-2 yr-1 and that carbon inventories decreased in sediments fertilized with nitrogen and phosphorus. Fertilized plots became net sources of carbon to the atmosphere, and sediment respiration continues in these plots at an accelerated pace. After 12 yr of treatment, soil macroorganic matter in the top 5 cm of sediment was 475 g C m-2 lower in fertilized plots than in controls, which is equivalent to a constant loss rate of 40 g C m-2 yr-1. It is not known whether soil carbon in fertilized plots has reached a new equilibrium or continues to decline. The increase in soil respiration in the fertilized plots was far greater than the loss of sediment organic matter, which indicates that the increase in soil respiration was largely due to an increase in primary production. Sediment respiration in laboratory incubations also demonstrated positive effects of nutrients. Thus, the results indicate that increased nutrient loading of oligotrophic wetlands can lead to an increased rate of sediment carbon turnover and a net loss of carbon from sediments.

  9. Balancing Power Absorption and Structural Loading for an Asymmetric Heave Wave-Energy Converter in Regular Waves

    SciTech Connect

    Tom, Nathan M.; Madhi, Farshad; Yeung, Ronald W.

    2016-06-24

    The aim of this paper is to maximize the power-to-load ratio of the Berkeley Wedge: a one-degree-of-freedom, asymmetrical, energy-capturing, floating breakwater of high performance that is relatively free of viscosity effects. Linear hydrodynamic theory was used to calculate bounds on the expected time-averaged power (TAP) and corresponding surge restraining force, pitch restraining torque, and power take-off (PTO) control force when assuming that the heave motion of the wave energy converter remains sinusoidal. This particular device was documented to be an almost-perfect absorber if one-degree-of-freedom motion is maintained. The success of such or similar future wave energy converter technologies would require the development of control strategies that can adapt device performance to maximize energy generation in operational conditions while mitigating hydrodynamic loads in extreme waves to reduce the structural mass and overall cost. This paper formulates the optimal control problem to incorporate metrics that provide a measure of the surge restraining force, pitch restraining torque, and PTO control force. The optimizer must now handle an objective function with competing terms in an attempt to maximize power capture while minimizing structural and actuator loads. A penalty weight is placed on the surge restraining force, pitch restraining torque, and PTO actuation force, thereby allowing the control focus to be placed either on power absorption or load mitigation. Thus, in achieving these goals, a per-unit gain in TAP would not lead to a greater per-unit demand in structural strength, hence yielding a favorable benefit-to-cost ratio. Demonstrative results in the form of TAP, reactive TAP, and the amplitudes of the surge restraining force, pitch restraining torque, and PTO control force are shown for the Berkeley Wedge example.

  10. Balancing Power Absorption and Structural Loading for an Assymmetric Heave Wave-Energy Converter in Regular Waves: Preprint

    SciTech Connect

    Tom, Nathan M.; Madhi, Farshad; Yeung, Ronald W.

    2016-07-01

    The aim of this paper is to maximize the power-to-load ratio of the Berkeley Wedge: a one-degree-of-freedom, asymmetrical, energy-capturing, floating breakwater of high performance that is relatively free of viscosity effects. Linear hydrodynamic theory was used to calculate bounds on the expected time-averaged power (TAP) and corresponding surge restraining force, pitch restraining torque, and power take-off (PTO) control force when assuming that the heave motion of the wave energy converter remains sinusoidal. This particular device was documented to be an almost-perfect absorber if one-degree-of-freedom motion is maintained. The success of such or similar future wave energy converter technologies would require the development of control strategies that can adapt device performance to maximize energy generation in operational conditions while mitigating hydrodynamic loads in extreme waves to reduce the structural mass and overall cost. This paper formulates the optimal control problem to incorporate metrics that provide a measure of the surge restraining force, pitch restraining torque, and PTO control force. The optimizer must now handle an objective function with competing terms in an attempt to maximize power capture while minimizing structural and actuator loads. A penalty weight is placed on the surge restraining force, pitch restraining torque, and PTO actuation force, thereby allowing the control focus to be placed either on power absorption or load mitigation. Thus, in achieving these goals, a per-unit gain in TAP would not lead to a greater per-unit demand in structural strength, hence yielding a favorable benefit-to-cost ratio. Demonstrative results in the form of TAP, reactive TAP, and the amplitudes of the surge restraining force, pitch restraining torque, and PTO control force are shown for the Berkeley Wedge example.

  11. Estimating sediment loads in an intra-Apennine catchments: balance between modeling and monitoring

    NASA Astrophysics Data System (ADS)

    Pelacani, Samanta; Cassi, Paola; Borselli, Lorenzo

    2010-05-01

    an 8 time increase in suspended sediment load. Furthermore, the fine-grained (<62.5 µm) sediments have been stored in the gravel river bed, where from deposit become a sediment supply. The presence of check dams and pools causes sedimentation, that plays an important role on degradation of fluvial habitat. Also, intrinsic to the process of mobilization, transport and sedimentation is the chemistry of the stream water, such as a high pH (8.15 - 9.15) and the E.C. (5.0-12.4 µs cm-1) that cause the dispersion of the sediments. On the other hand, the use of flocculants, Ca-salts, by the construction firms retards the sediment mobility. The sediment delivery is therefore the result of this interactions, that are not take into account by the soil erosion model. Salvador Sanchis M. P. , Torri D. ,Borselli L.,Poesen J.(2007). Climate effects on soil erodibility. Earth Surface Processes and Landforms 33 (7): 1082 - 1097. Borselli L., Cassi P., Torri D.(2008). Prolegomena to sediment and flow connectivity in the landscape: a Gis and field numerical assessment. Catena 75 (3): 268-277.

  12. Addition of hydrochlorothiazide to angiotensin receptor blocker therapy can achieve a lower sodium balance with no acceleration of intrarenal renin angiotensin system in patients with chronic kidney disease

    PubMed Central

    Fuwa, Daisuke; Fukuda, Michio; Ogiyama, Yoshiaki; Sato, Ryo; Mizuno, Masashi; Miura, Toshiyuki; Abe-Dohmae, Sumiko; Michikawa, Makoto; Kobori, Hiroyuki; Ohte, Nobuyuki

    2016-01-01

    Objective Angiotensin receptor blockers (ARBs) produce a lower sodium (Na) balance, and the natriuretic effect is enhanced under Na deprivation, despite falls in blood pressure (BP) and glomerular filtration rate (GFR). Methods The effect of additional hydrochlorothiazide (HCTZ; 12.5 mg/day) to ARB treatment (valsartan; 80 mg/day) on glomerulotubular Na balance was evaluated in 23 patients with chronic kidney disease. Results Add-on HCTZ decreased GFR, tubular Na load, and tubular Na reabsorption (tNa), although 24-hour urinary Na excretion (UNaV) remained constant. Daily urinary angiotensinogen excretion (UAGTV, 152±10→82±17 μg/g Cre) reduced (p=0.02). Changes in tubular Na load (r2=0.26) and tNa (r2=0.25) correlated with baseline 24-hour UAGTV. Changes in filtered Na load correlated with changes in nighttime systolic BP (r2=0.17), but not with changes in daytime systolic BP. The change in the tNa to filtered Na load ratio was influenced by the change in daytime UNaV (β=−0.67, F=16.8), rather than the change in nighttime UNaV. Conclusions Lower Na balance was produced by add-on HCTZ to ARB treatment without an increase of intra-renal renin-angiotensin system activity, leading to restoration of nocturnal hypertension. A further study is needed to demonstrate that the reduction of UAGTV by additional diuretics to ARBs prevents the progression of nephropathy or cardiovascular events. PMID:27283968

  13. Towards robust algorithms for current deposition and dynamic load-balancing in a GPU particle in cell code

    NASA Astrophysics Data System (ADS)

    Rossi, Francesco; Londrillo, Pasquale; Sgattoni, Andrea; Sinigardi, Stefano; Turchetti, Giorgio

    2012-12-01

    We present `jasmine', an implementation of a fully relativistic, 3D, electromagnetic Particle-In-Cell (PIC) code, capable of running simulations in various laser plasma acceleration regimes on Graphics-Processing-Units (GPUs) HPC clusters. Standard energy/charge preserving FDTD-based algorithms have been implemented using double precision and quadratic (or arbitrary sized) shape functions for the particle weighting. When porting a PIC scheme to the GPU architecture (or, in general, a shared memory environment), the particle-to-grid operations (e.g. the evaluation of the current density) require special care to avoid memory inconsistencies and conflicts. Here we present a robust implementation of this operation that is efficient for any number of particles per cell and particle shape function order. Our algorithm exploits the exposed GPU memory hierarchy and avoids the use of atomic operations, which can hurt performance especially when many particles lay on the same cell. We show the code multi-GPU scalability results and present a dynamic load-balancing algorithm. The code is written using a python-based C++ meta-programming technique which translates in a high level of modularity and allows for easy performance tuning and simple extension of the core algorithms to various simulation schemes.

  14. What Works to Improve Student Literacy Achievement? An Examination of Instructional Practices in a Balanced Literacy Approach

    ERIC Educational Resources Information Center

    Bitter, Catherine; O'Day, Jennifer; Gubbins, Paul; Socias, Miguel

    2009-01-01

    A core assumption of the San Diego City Schools (SDCS) reform effort was that improved instructional practices, aligned with a balanced literacy approach, would be effective in improving student outcomes. This article explores this hypothesis by presenting findings from an analysis of classroom instruction data collected in 101 classrooms in 9…

  15. Adolescent Boys' and Girls' Block Constructions Differ in Structural Balance: A Block-Building Characteristic Related to Math Achievement

    ERIC Educational Resources Information Center

    Casey, Beth M.; Pezaris, Elizabeth E.; Bassi, Julie

    2012-01-01

    Two studies were conducted on block building in adolescents, assessing middle school (Study 1) and high school students (Study 2). Students were asked to build something interesting with blocks. In both samples, the same pattern of gender differences were found; boys built taller structures than girls, and balanced a larger number of blocks on a…

  16. The effect of adjusting model inputs to achieve mass balance on time-dynamic simulations in a food-web model of Lake Huron

    USGS Publications Warehouse

    Langseth, Brian J.; Jones, Michael L.; Riley, Stephen C.

    2014-01-01

    Ecopath with Ecosim (EwE) is a widely used modeling tool in fishery research and management. Ecopath requires a mass-balanced snapshot of a food web at a particular point in time, which Ecosim then uses to simulate changes in biomass over time. Initial inputs to Ecopath, including estimates for biomasses, production to biomass ratios, consumption to biomass ratios, and diets, rarely produce mass balance, and thus ad hoc changes to inputs are required to balance the model. There has been little previous research of whether ad hoc changes to achieve mass balance affect Ecosim simulations. We constructed an EwE model for the offshore community of Lake Huron, and balanced the model using four contrasting but realistic methods. The four balancing methods were based on two contrasting approaches; in the first approach, production of unbalanced groups was increased by increasing either biomass or the production to biomass ratio, while in the second approach, consumption of predators on unbalanced groups was decreased by decreasing either biomass or the consumption to biomass ratio. We compared six simulation scenarios based on three alternative assumptions about the extent to which mortality rates of prey can change in response to changes in predator biomass (i.e., vulnerabilities) under perturbations to either fishing mortality or environmental production. Changes in simulated biomass values over time were used in a principal components analysis to assess the comparative effect of balancing method, vulnerabilities, and perturbation types. Vulnerabilities explained the most variation in biomass, followed by the type of perturbation. Choice of balancing method explained little of the overall variation in biomass. Under scenarios where changes in predator biomass caused large changes in mortality rates of prey (i.e., high vulnerabilities), variation in biomass was greater than when changes in predator biomass caused only small changes in mortality rates of prey (i.e., low

  17. Genotypic Variation in Grain P Loading across Diverse Rice Growing Environments and Implications for Field P Balances.

    PubMed

    Vandamme, Elke; Wissuwa, Matthias; Rose, Terry; Dieng, Ibnou; Drame, Khady N; Fofana, Mamadou; Senthilkumar, Kalimuthu; Venuprasad, Ramaiah; Jallow, Demba; Segda, Zacharie; Suriyagoda, Lalith; Sirisena, Dinarathna; Kato, Yoichiro; Saito, Kazuki

    2016-01-01

    More than 60% of phosphorus (P) taken up by rice (Oryza spp.) is accumulated in the grains at harvest and hence exported from fields, leading to a continuous removal of P. If P removed from fields is not replaced by P inputs then soil P stocks decline, with consequences for subsequent crops. Breeding rice genotypes with a low concentration of P in the grains could be a strategy to reduce maintenance fertilizer needs and slow soil P depletion in low input systems. This study aimed to assess variation in grain P concentrations among rice genotypes across diverse environments and evaluate the implications for field P balances at various grain yield levels. Multi-location screening experiments were conducted at different sites across Africa and Asia and yield components and grain P concentrations were determined at harvest. Genotypic variation in grain P concentration was evaluated while considering differences in P supply and grain yield using cluster analysis to group environments and boundary line analysis to determine minimum grain P concentrations at various yield levels. Average grain P concentrations across genotypes varied almost 3-fold among environments, from 1.4 to 3.9 mg g(-1). Minimum grain P concentrations associated with grain yields of 150, 300, and 500 g m(-2) varied between 1.2 and 1.7, 1.3 and 1.8, and 1.7 and 2.2 mg g(-1) among genotypes respectively. Two genotypes, Santhi Sufaid and DJ123, were identified as potential donors for breeding for low grain P concentration. Improvements in P balances that could be achieved by exploiting this genotypic variation are in the range of less than 0.10 g P m(-2) (1 kg P ha(-1)) in low yielding systems, and 0.15-0.50 g P m(-2) (1.5-5.0 kg P ha(-1)) in higher yielding systems. Improved crop management and alternative breeding approaches may be required to achieve larger reductions in grain P concentrations in rice.

  18. Genotypic Variation in Grain P Loading across Diverse Rice Growing Environments and Implications for Field P Balances

    PubMed Central

    Vandamme, Elke; Wissuwa, Matthias; Rose, Terry; Dieng, Ibnou; Drame, Khady N.; Fofana, Mamadou; Senthilkumar, Kalimuthu; Venuprasad, Ramaiah; Jallow, Demba; Segda, Zacharie; Suriyagoda, Lalith; Sirisena, Dinarathna; Kato, Yoichiro; Saito, Kazuki

    2016-01-01

    More than 60% of phosphorus (P) taken up by rice (Oryza spp.) is accumulated in the grains at harvest and hence exported from fields, leading to a continuous removal of P. If P removed from fields is not replaced by P inputs then soil P stocks decline, with consequences for subsequent crops. Breeding rice genotypes with a low concentration of P in the grains could be a strategy to reduce maintenance fertilizer needs and slow soil P depletion in low input systems. This study aimed to assess variation in grain P concentrations among rice genotypes across diverse environments and evaluate the implications for field P balances at various grain yield levels. Multi-location screening experiments were conducted at different sites across Africa and Asia and yield components and grain P concentrations were determined at harvest. Genotypic variation in grain P concentration was evaluated while considering differences in P supply and grain yield using cluster analysis to group environments and boundary line analysis to determine minimum grain P concentrations at various yield levels. Average grain P concentrations across genotypes varied almost 3-fold among environments, from 1.4 to 3.9 mg g−1. Minimum grain P concentrations associated with grain yields of 150, 300, and 500 g m−2 varied between 1.2 and 1.7, 1.3 and 1.8, and 1.7 and 2.2 mg g−1 among genotypes respectively. Two genotypes, Santhi Sufaid and DJ123, were identified as potential donors for breeding for low grain P concentration. Improvements in P balances that could be achieved by exploiting this genotypic variation are in the range of less than 0.10 g P m−2 (1 kg P ha−1) in low yielding systems, and 0.15–0.50 g P m−2 (1.5–5.0 kg P ha−1) in higher yielding systems. Improved crop management and alternative breeding approaches may be required to achieve larger reductions in grain P concentrations in rice. PMID:27729916

  19. Inter-model, analytical, and experimental validation of a heat balance based residential cooling load calculation procedure

    NASA Astrophysics Data System (ADS)

    Xiao, Dongyi

    Scope and method of study. A systematic validation of the ASHRAE heat balance based residential cooling load calculation procedure (RHB) has been performed with inter-model comparison, analytical verification and experimental validation. The inter-model validation was performed using ESP-r as the reference model. The testing process was automated through parametric generation and simulation of large sets of test cases for both RHB and ESP-r. The house prototypes covered include a simple Shoebox prototype and a real 4-bedroom house prototype. An analytical verification test suite for building fabric models of whole building energy simulation programs has been developed. The test suite consists of a series of sixteen tests covering convection, conduction, solar irradiation, long-wave radiation, infiltration and ground-coupled floors. Using the test suite, a total of twelve analytical tests have been done with the RHB procedure. The experimental validation has been conducted using experimental data collected from a Cardinal Project house located in Fort Wayne, Indiana. During the diagnostic process of the experimental validation, comparisons have also been made between ESP-r simulation results and experimental data. Findings and conclusions. It is concluded RHB is acceptable as a design tool on a typical North American house. Analytical tests confirmed the underlying mechanisms for modeling basic heat transfer phenomena in building fabric. The inter-model comparison showed that the differences found between RHB and ESP-r can be traced to the differences in sub-models used by RHB and ESP-r. It also showed that the RHB-designed systems can meet the design criteria and that the RHB temperature swing option is helpful in reducing system over-sizing. The experimental validation demonstrated that the systems designed with the method will have adequate size to meet the room temperatures specified in the design, whether or not swing is utilized. However, actual system

  20. Large-scale Particle Simulations for Debris Flows using Dynamic Load Balance on a GPU-rich Supercomputer

    NASA Astrophysics Data System (ADS)

    Tsuzuki, Satori; Aoki, Takayuki

    2016-04-01

    Numerical simulations for debris flows including a countless of objects is one of important topics in fluid dynamics and many engineering applications. Particle-based method is a promising approach to carry out the simulations for flows interacting with objects. In this paper, we propose an efficient method to realize a large-scale simulation for fluid-structure interaction by combining SPH (Smoothed Particle Hydrodynamics) method for fluid with DEM (Discrete Element Method) for objects on a multi-GPU system. By applying space filling curves to decomposition of the computational domain, we are able to contain the same number of particles in each decomposed domain. In our implementation, several techniques for particle counting and data movement have been introduced. Fragmentation of the memory used for particles happens during the time-integration and the frequency of de-fragmentation is examined by taking account for computational load balance and the communication cost between CPU and GPU. A link-list technique of the particle interaction is introduced to save the memory drastically. It is found that the sorting of particle data for the neighboring particle list using linked-list method improves the memory access greatly with a certain interval. The weak and strong scalabilities for a SPH simulation using 111 Million particles was measured from 4 GPUs to 512 GPUs for three types of space filling curves. A large-scale debris flow simulation of tsunami with 10,368 floating rubbles using 117 Million particles were successfully carried out with 256 GPUs on the TSUBAME 2.5 supercomputer at Tokyo Institute of Technology.

  1. An organizational cybernetics framework for achieving balance in evidence-based practice and practice-based evidence.

    PubMed

    Fitch, Dale

    2014-01-01

    This article applies the systems science of organizational cybernetics to the implementation of evidence-based practice (EBP) in the provision of social work services in a residential treatment center setting. It does so by systemically balancing EBP with practice-based evidence (PBE) with a focus on the organizational and information system infrastructures necessary to ensure successful implementation. This application is illustrated by discussing a residential treatment program that implemented evidence-based programming and evaluated the results; however, the systemic principles articulated can be applied to any human services organizational setting.

  2. Comparing Balance and Inverse Methods on Learning Conceptual and Procedural Knowledge in Equation Solving: A Cognitive Load Perspective

    ERIC Educational Resources Information Center

    Ngu, Bing Hiong; Phan, Huy Phuong

    2016-01-01

    We examined the use of balance and inverse methods in equation solving. The main difference between the balance and inverse methods lies in the operational line (e.g. +2 on both sides vs -2 becomes +2). Differential element interactivity favours the inverse method because the interaction between elements occurs on both sides of the equation for…

  3. Tenure Track Policy Increases Representation of Women in Senior Academic Positions, but Is Insufficient to Achieve Gender Balance

    PubMed Central

    Bakker, Martha M.; Jacobs, Maarten H.

    2016-01-01

    Underrepresentation of women in senior positions is a persistent problem in universities worldwide, and a wide range of strategies to combat this situation is currently being contemplated. One such strategy is the introduction of a tenure track system, in which decisions to promote scientific staff to higher ranks are guided by a set of explicit and transparent criteria, as opposed to earlier situations in which decisions were based on presumably more subjective impressions by superiors. We examined the effect of the introduction of a tenure track system at Wageningen University (The Netherlands) on male and female promotion rates. We found that chances on being promoted to higher levels were already fairly equal between men and women before the tenure track system was introduced, and improved–more for women than for men–after the introduction of the tenure track system. These results may partly be explained by affirmative actions, but also by the fact that legacy effects of historical discrimination have led to a more competitive female population of scientists. In spite of these outcomes, extrapolations of current promotion rates up to 2025 demonstrate that the equal or even higher female promotion rates do not lead to substantial improvement of the gender balance at higher levels (i.e., associate professor and higher). Since promotion rates are small compared to the total amount of staff, the current distribution of men and women will, especially at higher levels, exhibit a considerable degree of inertia—unless additional affirmative action is taken. PMID:27684072

  4. The Effect of Accents on Cognitive Load and Achievement: The Relationship between Students' Accent Perception and Accented Voice Instructions in Students' Achievement

    ERIC Educational Resources Information Center

    Ahn, Jeahyeon

    2010-01-01

    The purpose of this study was to investigate how an instructor's accent influences students' learning achievement. Furthermore, this study also explored how students' accent preference may affect their learning. Unlike native voices, accented voices were not natural to the native speakers; therefore, it required more cognitive resources for…

  5. Carbon mass balance and microbial ecology in a laboratory scale reactor achieving simultaneous sludge reduction and nutrient removal.

    PubMed

    Huang, Pei; Li, Liang; Kotay, Shireen Meher; Goel, Ramesh

    2014-04-15

    Solids reduction in activated sludge processes (ASP) at source using process manipulation has been researched widely over the last two-decades. However, the absence of nutrient removal component, lack of understanding on the organic carbon, and limited information on key microbial community in solids minimizing ASP preclude the widespread acceptance of sludge minimizing processes. In this manuscript, we report simultaneous solids reduction through anaerobiosis along with nitrogen and phosphorus removals. The manuscript also reports carbon mass balance using stable isotope of carbon, microbial ecology of nitrifiers and polyphosphate accumulating organisms (PAOs). Two laboratory scale reactors were operated in anaerobic-aerobic-anoxic (A(2)O) mode. One reactor was run in the standard mode (hereafter called the control-SBR) simulating conventional A(2)O type of activated sludge process and the second reactor was run in the sludge minimizing mode (called the modified-SBR). Unlike other research efforts where the sludge minimizing reactor was maintained at nearly infinite solids retention time (SRT). To sustain the efficient nutrient removal, the modified-SBR in this research was operated at a very small solids yield rather than at infinite SRT. Both reactors showed consistent NH3-N, phosphorus and COD removals over a period of 263 days. Both reactors also showed active denitrification during the anoxic phase even if there was no organic carbon source available during this phase, suggesting the presence of denitrifying PAOs (DNPAOs). The observed solids yield in the modified-SBR was 60% less than the observed solids yield in the control-SBR. Specific oxygen uptake rate (SOUR) for the modified-SBR was almost 44% more than the control-SBR under identical feeding conditions, but was nearly the same for both reactors under fasting conditions. The modified-SBR showed greater diversity of ammonia oxidizing bacteria and PAOs compared to the control-SBR. The diversity of PAOs

  6. Chronic metabolic acid load induced by changes in dietary electrolyte balance increased chloride retention but did not compromise bone in growing swine.

    PubMed

    Budde, R A; Crenshaw, T D

    2003-01-01

    The effects of chronic dietary acid loads on shifts in bone mineral reserves and physiological concentrations of cations and anions in extracellular fluids were assessed in growing swine. Four trials were conducted with a total of 38 (8.16 +/- 0.30 kg, mean +/- SEM) Large White x Landrace x Duroc pigs randomly assigned to one of three dietary treatments. Semipurified diets, fed for 13 to 17 d, provided an analyzed dietary electrolyte balance (dEB, meq/kg diet = Na+ + K+ - Cl-) of -35, 112, and 212 for the acidogenic, control, and alkalinogenic diets, respectively. Growth performance, arterial blood gas, serum chemistry, urine pH, mineral balance, bone mineral content gain, bone-breaking strength, bone ash, and percentage of bone ash were determined. Dietary treatments created a range of metabolic acid loads without affecting (P > 0.10) growth or feed intake. Urine pH was 5.71, 6.02, and 7.65 +/- 0.48 (mean +/- SEM) and arterial blood pH was 7.478, 7.485, and 7.526 +/- 0.006 for pigs fed acidogenic, control, and alkalinogenic treatments, respectively. A lower dEB resulted in an increased (P < 0.001) apparent Cl- retention (106.6, 55.4, and 41.2 +/- 6.3 meq/d), of which only 1.6% was accounted for by expansion of the extracellular fluid Cl- pool as calculated from serum Cl- (105.5, 103.4, 101.6 +/- 0.94 meq/L (mean +/- SEM) for pigs fed acidogenic, control, and alkalinogenic treatments, respectively. A lower dEB did not decrease (P > 0.10) bone mineral content gain, bone-breaking strength, bone ash, percentage of bone ash, or calcium and phosphate balance. In conclusion, bone mineral (phosphate) was not depleted to buffer the dietary acid load in growing pigs over a 3-wk period.

  7. Investigation of Unsteady Pressure-Sensitive Paint (uPSP) and a Dynamic Loads Balance to Predict Launch Vehicle Buffet Environments

    NASA Technical Reports Server (NTRS)

    Schuster, David M.; Panda, Jayanta; Ross, James C.; Roozeboom, Nettie H.; Burnside, Nathan J.; Ngo, Christina L.; Kumagai, Hiro; Sellers, Marvin; Powell, Jessica M.; Sekula, Martin K.; Piatak, David J.

    2016-01-01

    This NESC assessment examined the accuracy of estimating buffet loads on in-line launch vehicles without booster attachments using sparse unsteady pressure measurements. The buffet loads computed using sparse sensor data were compared with estimates derived using measurements with much higher spatial resolution. The current method for estimating launch vehicle buffet loads is through wind tunnel testing of models with approximately 400 unsteady pressure transducers. Even with this relatively large number of sensors, the coverage can be insufficient to provide reliable integrated unsteady loads on vehicles. In general, sparse sensor spacing requires the use of coherence-length-based corrections in the azimuthal and axial directions to integrate the unsteady pressures and obtain reasonable estimates of the buffet loads. Coherence corrections have been used to estimate buffet loads for a variety of launch vehicles with the assumption methodology results in reasonably conservative loads. For the Space Launch System (SLS), the first estimates of buffet loads exceeded the limits of the vehicle structure, so additional tests with higher sensor density were conducted to better define the buffet loads and possibly avoid expensive modifications to the vehicle design. Without the additional tests and improvements to the coherence-length analysis methods, there would have been significant impacts to the vehicle weight, cost, and schedule. If the load estimates turn out to be too low, there is significant risk of structural failure of the vehicle. This assessment used a combination of unsteady pressure-sensitive paint (uPSP), unsteady pressure transducers, and a dynamic force and moment balance to investigate the integration schemes used with limited unsteady pressure data by comparing them with direct integration of extremely dense fluctuating pressure measurements. An outfall of the assessment was to evaluate the potential of using the emerging uPSP technique in a production

  8. Achievement of balanced high frequency and high breakdown by InGaAs-based high-electron-mobility transistors with slant field plates

    NASA Astrophysics Data System (ADS)

    Hosotani, Tomotaka; Otsuji, Taiichi; Suemitsu, Tetsuya

    2016-11-01

    InGaAs-based high-electron-mobility transistors (HEMTs) with SiCN-based multistep slant field plates (FPs) and two-step recess (TSR) gates are fabricated and characterized. The slant FPs, which were originally developed for GaN-HEMTs, are integrated with InGaAs-HEMTs to increase the breakdown voltage (BV). The BVs of InGaAs-HEMTs increase by a factor of 1.5-2. However, FPs have a negative effect on the current gain cutoff frequency (f T). Consequently, BV and f T have a trade-off relationship. The combination of slant FPs and TSR gates enables the achievement of a balanced BV and f T of 8.0 V and 106 GHz, respectively, in 130-nm-gate-length InGaAs-HEMTs.

  9. Lipid nanoparticles: drug localization is substance-specific and achievable load depends on the size and physical state of the particles.

    PubMed

    Kupetz, Eva; Bunjes, Heike

    2014-09-10

    Lipid nanoemulsions and -suspensions are being intensively investigated as carriers for poorly water soluble drugs. The question on where model compounds or probes are localized within the dispersions has been the subject of several studies. However, only little data exists for pharmaceutically relevant molecules in dispersions composed of pharmaceutically relevant excipients. In this work, the localization of drugs and drug-like substances was studied in lipid nanoemulsions and -suspensions. Conclusions about the drug localization were drawn from the relations between lipid mass, specific particle surface area and drug load in the dispersions. Additionally, the achievable drug loads of the liquid and the solid lipid particles were compared. Nanoemulsions and -suspensions comprised trimyristin as lipid matrix and poloxamer 188 as emulsifier and were prepared with different well-defined particle sizes. These pre-formed dispersions were passively loaded with either amphotericin B, curcumin, dibucaine, fenofibrate, mefenamic acid, propofol, or a porphyrin derivative. The physico-chemical properties of the particles were characterized; drug load and lipid content were quantified by UV spectroscopy and high performance liquid chromatography, respectively. For all drugs the passive loading procedure was successful in both emulsions and suspensions. Solid particles accommodate drug molecules preferably at the particle surface. Liquid particles can accommodate drugs at the particle surface as well as in the core; the distribution between the two sites is drug specific. It is also drug specific whether solid or liquid particles yield higher drug loads. As a general rule, smaller particles led to higher drug loads than larger ones. Propofol and the porphyrin derivative displayed eutectic interaction with the lipid and crystal growth after loading, respectively.

  10. The Instructional Effects of Diagrams and Time-Compressed Instruction on Student Achievement and Learners' Perceptions of Cognitive Load

    ERIC Educational Resources Information Center

    Pastore, Raymond S.

    2009-01-01

    The purpose of this study was to examine the effects of visual representations and time-compressed instruction on learning and learners' perceptions of cognitive load. Time-compressed instruction refers to instruction that has been increased in speed without sacrificing quality. It was anticipated that learners would be able to gain a conceptual…

  11. The Effects of Social Cue Principles on Cognitive Load, Situational Interest, Motivation, and Achievement in Pedagogical Agent Multimedia Learning

    ERIC Educational Resources Information Center

    Park, Sanghoon

    2015-01-01

    Animated pedagogical agents have become popular in multimedia learning with combined delivery of verbal and non-verbal forms of information. In order to reduce unnecessary cognitive load caused by such multiple forms of information and also to foster generative cognitive processing, multimedia design principles with social cues are suggested…

  12. Development of a Two-Component Strain-Gauge-Balance Load-Measurement System for the DSTO Water Tunnel

    DTIC Science & Technology

    2006-03-01

    normal forces (Z) and pitching moments (m). The strain gauges have been glued onto the balance using a bonding material designated M-BOND 6003...compound designated M-coat C3, a solvent-thinned (naptha) RTV (room temperature vulcanizing ) silicone rubber. Care was taken to not use excessive...70º delta wing at high angles of attack and sideslip. Masters Thesis, Aeronautical Engineering Department, The Wichita State University, USA

  13. Novel techniques for data decomposition and load balancing for parallel processing of vision systems: Implementation and evaluation using a motion estimation system

    NASA Technical Reports Server (NTRS)

    Choudhary, Alok Nidhi; Leung, Mun K.; Huang, Thomas S.; Patel, Janak H.

    1989-01-01

    Computer vision systems employ a sequence of vision algorithms in which the output of an algorithm is the input of the next algorithm in the sequence. Algorithms that constitute such systems exhibit vastly different computational characteristics, and therefore, require different data decomposition techniques and efficient load balancing techniques for parallel implementation. However, since the input data for a task is produced as the output data of the previous task, this information can be exploited to perform knowledge based data decomposition and load balancing. Presented here are algorithms for a motion estimation system. The motion estimation is based on the point correspondence between the involved images which are a sequence of stereo image pairs. Researchers propose algorithms to obtain point correspondences by matching feature points among stereo image pairs at any two consecutive time instants. Furthermore, the proposed algorithms employ non-iterative procedures, which results in saving considerable amounts of computation time. The system consists of the following steps: (1) extraction of features; (2) stereo match of images in one time instant; (3) time match of images from consecutive time instants; (4) stereo match to compute final unambiguous points; and (5) computation of motion parameters.

  14. Universal electromagnetic suspension balance with nanogramme mass resolution for measurement of sorption on small samples in top and bottom loading configurations

    NASA Astrophysics Data System (ADS)

    Norton, C. G.; Petermann, M.; Fieback, T. M.

    2017-04-01

    Determination of mass increase or decrease of very small amplitude is a task which goes hand in hand with gravimetric adsorption and absorption measurement and thermogravimetry. Samples are subjected to various process conditions and as such can experience a change in mass, i.e. when adsorbing gas from the process atmosphere, or can decrease in mass, such as when being dried or when thermal decomposition takes place. Current instruments used for such analysis, especially at high pressures, are often based on magnetic suspension balances, and have a maximum mass resolution of a few 10‑6 g. This necessitates more often than not quite significant sample quantities, which can sometimes not easily be manufactured, e.g. in the case of metal organic framework adsorbents, or which in other cases do not have a sufficient specific surface area resulting in low measuring effect. A new apparatus based on a high resolution thermogravimetric analyser has been developed. This new apparatus combines very high resolution of up to a few 10‑8 g with a relatively high sample mass of up to 1.5 g, whilst eliminating many of the disadvantages of the microbalances previously used in magnetic suspension balances. An interface was developed which permits free configuration of the new balance as top or bottom loading. Validation measurements of known adsorbents were subsequently performed, with sample quantities up to a factor of 174 smaller than in literature.

  15. Using Simulink Simulation to Evaluate Load Following Characteristics of SOFC Generator with Heat Exchanger Considering Heat Balance

    NASA Astrophysics Data System (ADS)

    Tuyen, Nguyen Duc; Fujita, Goro; Yokoyama, Ryuichi; Koyanagi, Kaoru; Funabashi, Toshihisa; Nomura, Masakatsu

    That ever increasing electricity consumption, progress in power deregulation, and rising public awareness for environment have created more interest in fuel cell distributed generation. Among different types of fuel cells, solid oxide fuel cells (SOFCs) manifest themselves as great potential applications due to many advantages such as low emission, high efficiency, and high power rating. On the other hand, SOFC systems are beneficial because they can convert fuel such as natural gas (almost CH4) which is supplied by widespread systems in many countries into electricity efficiently using internal reforming. In facts, the load demand changes flexibly and fuel cell life time decreases by rapid thermal change. Its lifetime may be extended by maintaining in appropriate temperature. Therefore, it is important to acquire the load following performance as well as control of operation temperature. This paper addresses components of the simple SOFC power unit model with heat exchanger (HX) included. Typical dynamical submodels are used to follow the variation of load demand at a local location that considers temperature characteristics using the Matlab-SIMULINK program.

  16. Foraging grass-cutting ants (Atta vollenweideri) maintain stability by balancing their loads with controlled head movements.

    PubMed

    Moll, Karin; Roces, Flavio; Federle, Walter

    2010-07-01

    Grass-cutting ants (Atta vollenweideri) carry leaf fragments several times heavier and longer than the workers themselves over considerable distances back to their nest. Workers transport fragments in an upright, slightly backwards-tilted position. To investigate how they maintain stability and control the carried fragment's position, we measured head and fragment positions from video recordings. Load-transporting ants often fell over, demonstrating the biomechanical difficulty of this behavior. Long fragments were carried at a significantly steeper angle than short fragments of the same mass. Workers did not hold fragments differently between the mandibles, but performed controlled up and down head movements at the neck joint. By attaching additional mass at the fragment's tip to load-carrying ants, we demonstrated that they are able to adjust the fragment angle. When we forced ants to transport loads across inclines, workers walking uphill carried fragments at a significantly steeper angle, and downhill at a shallower angle than ants walking horizontally. However, we observed similar head movements in unladen workers, indicating a generalized reaction to slopes that may have other functions in addition to maintaining stability. Our results underline the importance of proximate, biomechanical factors for the understanding of the foraging process in leaf-cutting ants.

  17. Security-Oriented and Load-Balancing Wireless Data Routing Game in the Integration of Advanced Metering Infrastructure Network in Smart Grid

    SciTech Connect

    He, Fulin; Cao, Yang; Zhang, Jun Jason; Wei, Jiaolong; Zhang, Yingchen; Muljadi, Eduard; Gao, Wenzhong

    2016-11-21

    Ensuring flexible and reliable data routing is indispensable for the integration of Advanced Metering Infrastructure (AMI) networks, we propose a secure-oriented and load-balancing wireless data routing scheme. A novel utility function is designed based on security routing scheme. Then, we model the interactive security-oriented routing strategy among meter data concentrators or smart grid meters as a mixed-strategy network formation game. Finally, such problem results in a stable probabilistic routing scheme with proposed distributed learning algorithm. One contributions is that we studied that different types of applications affect the routing selection strategy and the strategy tendency. Another contributions is that the chosen strategy of our mixed routing can adaptively to converge to a new mixed strategy Nash equilibrium (MSNE) during the learning process in the smart grid.

  18. Effects of short-term aerobic exercise with and without external loading on bone metabolism and balance in postmenopausal women with osteoporosis.

    PubMed

    Roghani, Tayebeh; Torkaman, Giti; Movasseghe, Shafieh; Hedayati, Mehdi; Goosheh, Babak; Bayat, Noushin

    2013-02-01

    The aim of this study is to evaluate the effect of submaximal aerobic exercise with and without external loading on bone metabolism and balance in postmenopausal women with osteoporosis (OP). Thirty-six volunteer, sedentary postmenopausal women with OP were randomly divided into three groups: aerobic, weighted vest, and control. Exercise for the aerobic group consisted of 18 sessions of submaximal treadmill walking, 30 min daily, 3 times a week. The exercise program for the weighted-vest group was identical to that of the aerobic group except that the subjects wore a weighted vest (4-8 % of body weight). Body composition, bone biomarkers, bone-specific alkaline phosphatase (BALP) and N-terminal telopeptide of type 1 collagen (NTX), and balance (near tandem stand, NTS, and star-excursion, SE) were measured before and after the 6-week exercise program. Fat decreased (p = 0.01) and fat-free mass increased (p = 0.005) significantly in the weighted-vest group. BALP increased and NTX decreased significantly in both exercise groups (p ≤ 0.05). After 6 weeks of exercise, NTS score increased in the exercise groups and decreased in the control group (aerobic: +49.68 %, weighted vest: +104.66 %, and control: -28.96 %). SE values for all directions increased significantly in the weighted-vest group. Results showed that the two exercise programs stimulate bone synthesis and decrease bone resorption in postmenopausal women with OP, but that exercise while wearing a weighted vest is better for improving balance.

  19. Daily energy balance in growth hormone receptor/binding protein (GHR -/-) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency.

    PubMed

    Longo, Kenneth A; Berryman, Darlene E; Kelder, Bruce; Charoenthongtrakul, Soratree; Distefano, Peter S; Geddes, Brad J; Kopchick, John J

    2010-02-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR -/- mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (M(b)) changes and physical activity in 17month-old female GHR -/- mice and their age-matched wild type littermates. The GHR -/- mice were smaller, consumed more food per unit M(b), had greater EE per unit M(b) and had an increase in 24-h EE/M(b) that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR -/- mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, M(b) and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for M(b) and LMA, the GHR -/- mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR -/- mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR -/- mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final 3h of the dark phase. Therefore, we conclude that GHR -/- mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable M(b). Relative to wild type mice, the GHR -/- mice consumed more calories per unit M(b), which offset the disproportionate increase in their daily energy expenditure. While GHR -/- mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA.

  20. Daily energy balance in growth hormone receptor/binding protein (GHR−/−) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

    PubMed Central

    Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

    2009-01-01

    The goal of this study was to examine factors that contribute to energy balance in female GHR −/− mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR −/− mice and their age-matched wild type littermates. The GHR −/− mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR −/− mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR −/− mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR −/− mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR −/− mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR −/− mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR −/− mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR −/− mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

  1. Teaching Gene Technology in an Outreach Lab: Students' Assigned Cognitive Load Clusters and the Clusters' Relationships to Learner Characteristics, Laboratory Variables, and Cognitive Achievement

    NASA Astrophysics Data System (ADS)

    Scharfenberg, Franz-Josef; Bogner, Franz X.

    2013-02-01

    This study classified students into different cognitive load (CL) groups by means of cluster analysis based on their experienced CL in a gene technology outreach lab which has instructionally been designed with regard to CL theory. The relationships of the identified student CL clusters to learner characteristics, laboratory variables, and cognitive achievement were examined using a pre-post-follow-up design. Participants of our day-long module Genetic Fingerprinting were 409 twelfth-graders. During the module instructional phases (pre-lab, theoretical, experimental, and interpretation phases), we measured the students' mental effort (ME) as an index of CL. By clustering the students' module-phase-specific ME pattern, we found three student CL clusters which were independent of the module instructional phases, labeled as low-level, average-level, and high-level loaded clusters. Additionally, we found two student CL clusters that were each particular to a specific module phase. Their members reported especially high ME invested in one phase each: within the pre-lab phase and within the interpretation phase. Differentiating the clusters, we identified uncertainty tolerance, prior experience in experimentation, epistemic interest, and prior knowledge as relevant learner characteristics. We found relationships to cognitive achievement, but no relationships to the examined laboratory variables. Our results underscore the importance of pre-lab and interpretation phases in hands-on teaching in science education and the need for teachers to pay attention to these phases, both inside and outside of outreach laboratory learning settings.

  2. Mass balance and mass loading of polybrominated diphenyl ethers (PBDEs) in a tertiary wastewater treatment plant using SBSE-TD-GC/MS.

    PubMed

    Rocha-Gutiérrez, Beatriz A; Lee, Wen-Yee; Shane Walker, W

    2016-01-01

    A mass loading and mass balance analysis was performed on selected polybromodiphenyl ethers (PBDEs) in the first full-scale indirect potable reuse treatment plant in the United States. Chemical analysis of PBDEs was performed using an environmentally friendly sample preparation technique, called stir-bar sorptive extraction (SBSE), coupled with thermal desorption and gas chromatography/mass spectrometry (GC/MS). The three most dominant PBDEs found in all the samples were: BDE-47, BDE-99 and BDE-100. In the wastewater influent, the concentrations of studied PBDEs ranged from 94 to 775 ng/L, and in the effluent, the levels were below the detection limit. Concentrations in sludge ranged from 50 to 182 ng/g. In general, a removal efficiency of 92-96% of the PBDEs in the plant was accomplished through primary and secondary processes. The tertiary treatment process was able to effectively reduce the aforementioned PBDEs to less than 10 ng/L (>96% removal efficiency) in the effluent. If PBDEs remain in the treated wastewater effluent, they may pose environmental and health impacts through aquifer recharge, irrigation, and sludge final disposal.

  3. Achieving Work-Life Balance in the National Collegiate Athletic Association Division I Setting, Part I: The Role of the Head Athletic Trainer

    PubMed Central

    Mazerolle, Stephanie M.; Goodman, Ashley; Pitney, William A.

    2015-01-01

    Context: Supervisor support has been identified as key to the fulfillment of work-life balance for the athletic trainer (AT), yet limited literature exists on the perspectives of supervisors. Objective: To investigate how the head AT facilitates work-life balance among staff members within the National Collegiate Athletic Association Division I setting. Design: Qualitative study. Setting: Web-based management system. Patients or Other Participants: A total of 18 head ATs (13 men, 5 women; age = 44 ± 8 years, athletic training experience = 22 ± 7 years) volunteered for an asynchronous, Web-based interview. Data Collection and Analysis: Participants responded to a series of questions by journaling their thoughts and experiences. We included multiple-analyst triangulation, stakeholder checks, and peer review to establish data credibility. We analyzed the data via a general inductive approach. Results: Four prevailing themes emerged from the data: modeling work-life balance, encouraging disengagement from the AT role, cooperation and community workplace, and administrative support and understanding. Conclusions: Head ATs at the Division I level recognized the need to promote work-life balance among their staffs. They not only were supportive of policies that promote work-life balance, including spending time away from the role of the AT and teamwork among staff members, but also modeled and practiced the strategies that they promoted. PMID:25343530

  4. Energy savings and higher volumetric loading rate achieved in the conventional anoxic-oxic process for sewage treatment by enhancing biomass retention in the secondary clarifier.

    PubMed

    Zhang, Xueyu; Liu, Fengyuan; Zheng, Shaokui

    2017-06-01

    This is the first study to achieve a short HRT (∼2h for the A/O reactor), high MLSS (∼10gL(-1)), and high volumetric loading (∼3.7kg CODm(-3)d(-1) and ∼0.6kg NH4-Nm(-3)d(-1)) in the A/O process for sewage treatment by enhancing biomass retention in the secondary clarifier (∼4h settling time), which we refer to as the high-performance A/O process (HP-A/O) in this paper. Over 258days of continuous operation, with a decrease in HRT from 12 to 2h, remarkable COD (95±3%), NH4(+)-N (98±2%), TN (79±5%), and TP (74±10%) removals were stably achieved, while the air requirement significantly decreased by 22%. The HP-A/O process offers advantages over the conventional A/O process (6-8h for A/O reactor, 3-5gL(-1)MLSS, and ∼1.0kg CODm(-3)d(-1)) for sewage treatment in terms of its lower energy consumption, smaller footprint and reactor requirements.

  5. Better Bonded Ethernet Load Balancing

    SciTech Connect

    Gabler, Jason

    2006-09-29

    When a High Performance Storage System's mover shuttles large amounts of data to storage over a single Ethernet device that single channel can rapidly become saturated. Using Linux Ethernet channel bonding to address this and similar situations was not, until now, a viable solution. The various modes in which channel bonding could be configured always offered some benefit but only under strict conditions or at a system resource cost that was greater than the benefit gained by using channel bonding. Newer bonding modes designed by various networking hardware companies, helpful in such networking scenarios, were already present in their own switches. However, Linux-based systems were unable to take advantage of those new modes as they had not yet been implemented in the Linux kernel bonding driver. So, except for basic fault tolerance, Linux channel bonding could not positively combine separate Ethernet devices to provide the necessary bandwidth.

  6. People First Mission Always: A Historical Examination of the Need to Find the Balance Between Protecting the Force and Achieving the Mission

    DTIC Science & Technology

    2013-06-13

    protection policy must balance the competing interests of the state in order to allow for mission success, while still maintaining the combat effectiveness...people, can be equated to the possible effects of force protection on the success of the mission. Political and military resolve encapsulates two parts

  7. Automatic force balance calibration system

    NASA Technical Reports Server (NTRS)

    Ferris, Alice T. (Inventor)

    1996-01-01

    A system for automatically calibrating force balances is provided. The invention uses a reference balance aligned with the balance being calibrated to provide superior accuracy while minimizing the time required to complete the calibration. The reference balance and the test balance are rigidly attached together with closely aligned moment centers. Loads placed on the system equally effect each balance, and the differences in the readings of the two balances can be used to generate the calibration matrix for the test balance. Since the accuracy of the test calibration is determined by the accuracy of the reference balance and current technology allows for reference balances to be calibrated to within .+-.0.05%, the entire system has an accuracy of a .+-.0.2%. The entire apparatus is relatively small and can be mounted on a movable base for easy transport between test locations. The system can also accept a wide variety of reference balances, thus allowing calibration under diverse load and size requirements.

  8. On enforcing maximum principles and achieving element-wise species balance for advection-diffusion-reaction equations under the finite element method

    NASA Astrophysics Data System (ADS)

    Mudunuru, M. K.; Nakshatrala, K. B.

    2016-01-01

    We present a robust computational framework for advective-diffusive-reactive systems that satisfies maximum principles, the non-negative constraint, and element-wise species balance property. The proposed methodology is valid on general computational grids, can handle heterogeneous anisotropic media, and provides accurate numerical solutions even for very high Péclet numbers. The significant contribution of this paper is to incorporate advection (which makes the spatial part of the differential operator non-self-adjoint) into the non-negative computational framework, and overcome numerical challenges associated with advection. We employ low-order mixed finite element formulations based on least-squares formalism, and enforce explicit constraints on the discrete problem to meet the desired properties. The resulting constrained discrete problem belongs to convex quadratic programming for which a unique solution exists. Maximum principles and the non-negative constraint give rise to bound constraints while element-wise species balance gives rise to equality constraints. The resulting convex quadratic programming problems are solved using an interior-point algorithm. Several numerical results pertaining to advection-dominated problems are presented to illustrate the robustness, convergence, and the overall performance of the proposed computational framework.

  9. Balance Problems

    MedlinePlus

    ... version of this page please turn Javascript on. Balance Problems About Balance Problems Have you ever felt dizzy, lightheaded, or ... dizziness problem during the past year. Why Good Balance is Important Having good balance means being able ...

  10. First-line cART regimen impacts the course of CD8+ T-cell counts in HIV-infected patients that achieve sustained undetectable viral load.

    PubMed Central

    Poizot-Martin, Isabelle; Allavena, Clotilde; Delpierre, Cyrille; Duvivier, Claudine; Obry-Roguet, Véronique; Cano, Carla E.; Guillouet de Salvador, Francine; Rey, David; Dellamonica, Pierre; Cheret, Antoine; Cuzin, Lise; Katlama, Christine; Cabié, André; Hoen, Bruno

    2016-01-01

    Abstract The aim of the study was to investigate the impact of first-line combined antiretroviral therapy (cART) regimen on the course of CD8+ T-cell counts in human immunodeficiency virus (HIV)-infected patients. A retrospective observational study conducted on the French DAT’AIDS Cohort of HIV-infected patients. We selected 605 patients initiating a first-line cART between 2002 and 2009, and which achieved a sustained undetectable HIV plasma viral load (pVL) for at least 12 months without cART modification. The evolution of CD8+ T-cell counts according to cART regimen was assessed. CD8+ T-cell counts were assessed in 572 patients treated with 2NRTIs+1PI/r (n= 297), 2NRTIs+1NNRTI (n= 207) and 3NRTIs (n= 68). In multivariate analysis, after 12 months of follow-up, the 3NRTIs regimen was associated with a significantly smaller decrease of CD8+ T-cell count compared with NNRTI-containing regimens (–10.2 cells/μL in 3NRTIs vs –105.1 cells/μL; P=0.02) but not compared with PI-containing regimens (10.2 vs –60.9 cells/μL; P=0.21). After 24 months, the 3NRTIs regimen was associated with a smaller decrease of CD8+ T-cell count and % compared with PI/r- and NNRTI-containing regimens (0.2 in 3NRTIs vs –9.9 with PI/r-regimens, P=0.001, and vs –11.1 with NNRTI-regimens, p < 0.0001). A focus analysis on 11 patients treated with an INSTI-containing cART regimen during the study period showed after 12 months of follow-up, a median decrease of CD8+ T-cell count of –155 [inter quartile range: –302; –22] cells/μL. Our data highlight the fact that cART regimens have differential effects on CD8 pool down regulation. PMID:27741125

  11. The effectiveness of plug-in hybrid electric vehicles and renewable power in support of holistic environmental goals: Part 2 - Design and operation implications for load-balancing resources on the electric grid

    NASA Astrophysics Data System (ADS)

    Tarroja, Brian; Eichman, Joshua D.; Zhang, Li; Brown, Tim M.; Samuelsen, Scott

    2015-03-01

    A study has been performed that analyzes the effectiveness of utilizing plug-in vehicles to meet holistic environmental goals across the combined electricity and transportation sectors. In this study, plug-in hybrid electric vehicle (PHEV) penetration levels are varied from 0 to 60% and base renewable penetration levels are varied from 10 to 63%. The first part focused on the effect of installing plug-in hybrid electric vehicles on the environmental performance of the combined electricity and transportation sectors. The second part addresses impacts on the design and operation of load-balancing resources on the electric grid associated with fleet capacity factor, peaking and load-following generator capacity, efficiency, ramp rates, start-up events and the levelized cost of electricity. PHEVs using smart charging are found to counteract many of the disruptive impacts of intermittent renewable power on balancing generators for a wide range of renewable penetration levels, only becoming limited at high renewable penetration levels due to lack of flexibility and finite load size. This study highlights synergy between sustainability measures in the electric and transportation sectors and the importance of communicative dispatch of these vehicles.

  12. Shaft balancing

    DOEpatents

    Irwin, John A.

    1979-01-01

    A gas turbine engine has an internal drive shaft including one end connected to a driven load and an opposite end connected to a turbine wheel and wherein the shaft has an in situ adjustable balance system near the critical center of a bearing span for the shaft including two 360.degree. rings piloted on the outer diameter of the shaft at a point accessible through an internal engine panel; each of the rings has a small amount of material removed from its periphery whereby both of the rings are precisely unbalanced an equivalent amount; the rings are locked circumferentially together by radial serrations thereon; numbered tangs on the outside diameter of each ring identify the circumferential location of unbalance once the rings are locked together; an aft ring of the pair of rings has a spline on its inside diameter that mates with a like spline on the shaft to lock the entire assembly together.

  13. Balance Problems

    MedlinePlus

    ... often, it could be a sign of a balance problem. Balance problems can make you feel unsteady or as ... fall-related injuries, such as hip fracture. Some balance problems are due to problems in the inner ...

  14. Teaching Gene Technology in an Outreach Lab: Students' Assigned Cognitive Load Clusters and the Clusters' Relationships to Learner Characteristics, Laboratory Variables, and Cognitive Achievement

    ERIC Educational Resources Information Center

    Scharfenberg, Franz-Josef; Bogner, Franz X.

    2013-01-01

    This study classified students into different cognitive load (CL) groups by means of cluster analysis based on their experienced CL in a gene technology outreach lab which has instructionally been designed with regard to CL theory. The relationships of the identified student CL clusters to learner characteristics, laboratory variables, and…

  15. Protecting the green behind the gold: catchment-wide restoration efforts necessary to achieve nutrient and sediment load reduction targets in Gold Coast City, Australia.

    PubMed

    Waltham, Nathan J; Barry, Michael; McAlister, Tony; Weber, Tony; Groth, Dominic

    2014-10-01

    The Gold Coast City is the tourist center of Australia and has undergone rapid and massive urban expansion over the past few decades. The Broadwater estuary, in the heart of the City, not only offers an array of ecosystems services for many important aquatic wildlife species, but also supports the livelihood and lifestyles of residents. Not surprisingly, there have been signs of imbalance between these two major services. This study combined a waterway hydraulic and pollutant transport model to simulate diffuse nutrient and sediment loads under past and future proposed land-use changes. A series of catchment restoration initiatives were modeled in an attempt to define optimal catchment scale restoration efforts necessary to protect and enhance the City's waterways. The modeling revealed that for future proposed development, a business as usual approach to catchment management will not reduce nutrient and sediment loading sufficiently to protect the community values. Considerable restoration of upper catchment tributaries is imperative, combined with treatment of stormwater flow from intensively developed sub-catchment areas. Collectively, initiatives undertaken by regulatory authorities to date have successfully reduced nutrient and sediment loading reaching adjoining waterways, although these programs have been ad hoc without strategic systematic planning and vision. Future conservation requires integration of multidisciplinary science and proactive management driven by the high ecological, economical, and community values placed on the City's waterways. Long-term catchment restoration and conservation planning requires an extensive budget (including political and societal support) to handle ongoing maintenance issues associated with scale of restoration determined here.

  16. Protecting the Green Behind the Gold: Catchment-Wide Restoration Efforts Necessary to Achieve Nutrient and Sediment Load Reduction Targets in Gold Coast City, Australia

    NASA Astrophysics Data System (ADS)

    Waltham, Nathan J.; Barry, Michael; McAlister, Tony; Weber, Tony; Groth, Dominic

    2014-10-01

    The Gold Coast City is the tourist center of Australia and has undergone rapid and massive urban expansion over the past few decades. The Broadwater estuary, in the heart of the City, not only offers an array of ecosystems services for many important aquatic wildlife species, but also supports the livelihood and lifestyles of residents. Not surprisingly, there have been signs of imbalance between these two major services. This study combined a waterway hydraulic and pollutant transport model to simulate diffuse nutrient and sediment loads under past and future proposed land-use changes. A series of catchment restoration initiatives were modeled in an attempt to define optimal catchment scale restoration efforts necessary to protect and enhance the City's waterways. The modeling revealed that for future proposed development, a business as usual approach to catchment management will not reduce nutrient and sediment loading sufficiently to protect the community values. Considerable restoration of upper catchment tributaries is imperative, combined with treatment of stormwater flow from intensively developed sub-catchment areas. Collectively, initiatives undertaken by regulatory authorities to date have successfully reduced nutrient and sediment loading reaching adjoining waterways, although these programs have been ad hoc without strategic systematic planning and vision. Future conservation requires integration of multidisciplinary science and proactive management driven by the high ecological, economical, and community values placed on the City's waterways. Long-term catchment restoration and conservation planning requires an extensive budget (including political and societal support) to handle ongoing maintenance issues associated with scale of restoration determined here.

  17. The effect of dDAVP with saline loading on fluid balance during LBNP and standing after 24-hr head-down bedrest

    NASA Technical Reports Server (NTRS)

    Simanonok, K. E.; Fortney, S. M.; Ford, S. R.; Charles, J. B.; Ward, D. F.

    1994-01-01

    Shuttle astronauts currently drink approximately a quart of water with eight salt tablets before reentry to restore lost body fluid and thereby reduce the likelihood of cardiovascular instability and syncope during reentry and after landing. However, the saline loading countermeasure is not entirely effective in restoring orthostatic tolerance to preflight levels. We tested the hypothesis that the effectiveness of this countermeasure could be improved with the use of a vasopressin analog, 1-deamino-8-D-arginine vasopressin (dDAVP). The rationale for this approach is that reducing urine formation with exogenous vasopressin should increase the magnitude and duration of the vascular volume expansion produced by the saline load, and in so doing improve orthostatic tolerance during reentry and postflight.

  18. Sharing the rivers: Balancing the needs of people and fish against the backdrop of heavy sediment loads downstream from Mount Rainier, Washington

    NASA Astrophysics Data System (ADS)

    Magirl, C. S.; Czuba, J. A.; Czuba, C. R.; Curran, C. A.

    2012-12-01

    Despite heavy sediment loads, large winter floods, and floodplain development, the rivers draining Mount Rainier, a 4,392-m glaciated stratovolcano within 85 km of sea level at Puget Sound, Washington, support important populations of anadromous salmonids, including Chinook salmon and steelhead trout, both listed as threatened under the Endangered Species Act. Aggressive river-management approaches of the early 20th century, such as bank armoring and gravel dredging, are being replaced by more ecologically sensitive approaches including setback levees. However, ongoing aggradation rates of up to 8 cm/yr in lowland reaches present acute challenges for resource managers tasked with ensuring flood protection without deleterious impacts to aquatic ecology. Using historical sediment-load data and a recent reservoir survey of sediment accumulation, rivers draining Mount Rainer were found to carry total sediment yields of 350 to 2,000 tonnes/km2/yr, notably larger than sediment yields of 50 to 200 tonnes/km2/yr typical for other Cascade Range rivers. An estimated 70 to 94% of the total sediment load in lowland reaches originates from the volcano. Looking toward the future, transport-capacity analyses and sediment-transport modeling suggest that large increases in bedload and associated aggradation will result from modest increases in rainfall and runoff that are predicted under future climate conditions. If large sediment loads and associated aggradation continue, creative solutions and long-term management strategies are required to protect people and structures in the floodplain downstream of Mount Rainier while preserving aquatic ecosystems.

  19. Computer simulation of the effect of dDAVP with saline loading on fluid balance after 24-hour head-down tilt

    NASA Technical Reports Server (NTRS)

    Srinivasan, R. S.; Simanonok, K. E.; Charles, J. B.

    1994-01-01

    Fluid loading (FL) before Shuttle reentry is a countermeasure currently in use by NASA to improve the orthostatic tolerance of astronauts during reentry and postflight. The fluid load consists of water and salt tablets equivalent to 32 oz (946 ml) of isotonic saline. However, the effectiveness of this countermeasure has been observed to decrease with the duration of spaceflight. The countermeasure's effectiveness may be improved by enhancing fluid retention using analogs of vasopressin such as lypressin (LVP) and desmopressin (dDAVP). In a computer simulation study reported previously, we attempted to assess the improvement in fluid retention obtained by the use of LVP administered before FL. The present study is concerned with the use of dDAVP. In a recent 24-hour, 6 degree head-down tilt (HDT) study involving seven men, dDAVP was found to improve orthostatic tolerance as assessed by both lower body negative pressure (LBNP) and stand tests. The treatment restored Luft's cumulative stress index (cumulative product of magnitude and duration of LBNP) to nearly pre-bedrest level. The heart rate was lower and stroke volume was marginally higher at the same LBNP levels with administration of dDAVP compared to placebo. Lower heart rates were also observed with dDAVP during stand test, despite the lower level of cardiovascular stress. These improvements were seen with only a small but significant increase in plasma volume of approximately 3 percent. This paper presents a computer simulation analysis of some of the results of this HDT study.

  20. Energy Balance and Obesity

    PubMed Central

    Hill, James O.; Wyatt, Holly R.; Peters, John C.

    2012-01-01

    This paper describes the interplay among energy intake, energy expenditure and body energy stores and illustrates how an understanding of energy balance can help develop strategies to reduce obesity. First, reducing obesity will require modifying both energy intake and energy expenditure and not simply focusing on either alone. Food restriction alone will not be effective in reducing obesity if human physiology is biased toward achieving energy balance at a high energy flux (i.e. at a high level of energy intake and expenditure). In previous environments a high energy flux was achieved with a high level of physical activity but in today's sedentary environment it is increasingly achieved through weight gain. Matching energy intake to a high level of energy expenditure will likely be more a more feasible strategy for most people to maintain a healthy weight than restricting food intake to meet a low level of energy expenditure. Second, from an energy balance point of view we are likely to be more successful in preventing excessive weight gain than in treating obesity. This is because the energy balance system shows much stronger opposition to weight loss than to weight gain. While large behavior changes are needed to produce and maintain reductions in body weight, small behavior changes may be sufficient to prevent excessive weight gain. In conclusion, the concept of energy balance combined with an understanding of how the body achieves balance may be a useful framework in helping develop strategies to reduce obesity rates. PMID:22753534

  1. Radar channel balancing with commutation

    SciTech Connect

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  2. Evolved strains of Scheffersomyces stipitis achieving high ethanol productivity on acid- and base-pretreated biomass hydrolyzate at high solids loading

    DOE PAGES

    Slininger, Patricia J.; Shea-Andersh, Maureen A.; Thompson, Stephanie R.; ...

    2015-04-09

    Lignocellulosic biomass is an abundant, renewable feedstock useful for the production of fuel-grade ethanol via the processing steps of pretreatment, enzyme hydrolysis, and microbial fermentation. Traditional industrial yeasts do not ferment xylose and are not able to grow, survive, or ferment in concentrated hydrolyzates that contain enough sugar to support economical ethanol recovery since they are laden with toxic byproducts generated during pretreatment. Repetitive culturing in two types of concentrated hydrolyzates was applied along with ethanol challenged xylose-fed continuous culture to force targeted evolution of the native pentose fermenting yeast Scheffersomyces (Pichia) stipitis strain NRRL Y-7124 maintained in the ARSmore » Culture Collection, Peoria, IL. Isolates collected from various enriched populations were screened and ranked based on relative xylose uptake rate and ethanol yield. Ranking on hydrolyzates with and without nutritional supplementation was used to identify those isolates with best performance across diverse conditions. Robust S. stipitis strains adapted to perform very well in enzyme hydrolyzates of high solids loading ammonia fiber expansion-pretreated corn stover (18% weight per volume solids) and dilute sulfuric acid-pretreated switchgrass (20% w/v solids) were obtained. Improved features include reduced initial lag phase preceding growth, significantly enhanced fermentation rates, improved ethanol tolerance and yield, reduced diauxic lag during glucose-xylose transition, and ability to accumulate >40 g/L ethanol in <167 h when fermenting hydrolyzate at low initial cell density of 0.5 absorbance units and pH 5 to 6.« less

  3. HASEonGPU-An adaptive, load-balanced MPI/GPU-code for calculating the amplified spontaneous emission in high power laser media

    NASA Astrophysics Data System (ADS)

    Eckert, C. H. J.; Zenker, E.; Bussmann, M.; Albach, D.

    2016-10-01

    We present an adaptive Monte Carlo algorithm for computing the amplified spontaneous emission (ASE) flux in laser gain media pumped by pulsed lasers. With the design of high power lasers in mind, which require large size gain media, we have developed the open source code HASEonGPU that is capable of utilizing multiple graphic processing units (GPUs). With HASEonGPU, time to solution is reduced to minutes on a medium size GPU cluster of 64 NVIDIA Tesla K20m GPUs and excellent speedup is achieved when scaling to multiple GPUs. Comparison of simulation results to measurements of ASE in Y b 3 + : Y AG ceramics show perfect agreement.

  4. Tibiofemoral alignment in posterior stabilized total knee arthroplasty: Static alignment does not predict dynamic tibial plateau loading.

    PubMed

    Miller, Emily J; Pagnano, Mark W; Kaufman, Kenton R

    2014-08-01

    For total knee arthroplasty (TKA), neutral mechanical alignment produces balanced static knee loading. Dynamically, knee loading is affected by more than limb static alignment. We compared static and dynamic knee loading following TKA. Fifteen TKA patients were evaluated pre-operatively and 2 months and 2 years post-operatively. Tibiofemoral angles and medial tibial plateau loading were calculated. Pre-operatively, static medial load was greater for varus than valgus knees. Post-operatively, no relationship existed between tibiofemoral angle and static medial plateau load. Pre-operatively and post-operatively, dynamic medial load was not dependent on tibiofemoral angle. While all patients achieved equal static plateau load distributions at 2 years, only 47% had dynamic medial load distributions of 50 ± 10%. Static tibiofemoral alignment alone does not predict dynamic tibial loading.

  5. Evolved strains of Scheffersomyces stipitis achieving high ethanol productivity on acid- and base-pretreated biomass hydrolyzate at high solids loading

    SciTech Connect

    Slininger, Patricia J.; Shea-Andersh, Maureen A.; Thompson, Stephanie R.; Dien, Bruce S.; Kurtzman, Cletus P.; Balan, Venkatesh; da Costa Sousa, Leonardo; Uppugundla, Nirmal; Dale, Bruce E; Cotta, Michael A

    2015-04-09

    Lignocellulosic biomass is an abundant, renewable feedstock useful for the production of fuel-grade ethanol via the processing steps of pretreatment, enzyme hydrolysis, and microbial fermentation. Traditional industrial yeasts do not ferment xylose and are not able to grow, survive, or ferment in concentrated hydrolyzates that contain enough sugar to support economical ethanol recovery since they are laden with toxic byproducts generated during pretreatment. Repetitive culturing in two types of concentrated hydrolyzates was applied along with ethanol challenged xylose-fed continuous culture to force targeted evolution of the native pentose fermenting yeast Scheffersomyces (Pichia) stipitis strain NRRL Y-7124 maintained in the ARS Culture Collection, Peoria, IL. Isolates collected from various enriched populations were screened and ranked based on relative xylose uptake rate and ethanol yield. Ranking on hydrolyzates with and without nutritional supplementation was used to identify those isolates with best performance across diverse conditions. Robust S. stipitis strains adapted to perform very well in enzyme hydrolyzates of high solids loading ammonia fiber expansion-pretreated corn stover (18% weight per volume solids) and dilute sulfuric acid-pretreated switchgrass (20% w/v solids) were obtained. Improved features include reduced initial lag phase preceding growth, significantly enhanced fermentation rates, improved ethanol tolerance and yield, reduced diauxic lag during glucose-xylose transition, and ability to accumulate >40 g/L ethanol in <167 h when fermenting hydrolyzate at low initial cell density of 0.5 absorbance units and pH 5 to 6.

  6. Laser Balancing

    NASA Astrophysics Data System (ADS)

    1981-01-01

    Mechanical Technology, Incorporated developed a fully automatic laser machining process that allows more precise balancing removes metal faster, eliminates excess metal removal and other operator induced inaccuracies, and provides significant reduction in balancing time. Manufacturing costs are reduced as a result.

  7. Baby Carriage: Infants Walking with Loads

    ERIC Educational Resources Information Center

    Garciaguirre, Jessie S.; Adolph, Karen E.; Shrout, Patrick E.

    2007-01-01

    Maintaining balance is a central problem for new walkers. To examine how infants cope with the additional balance control problems induced by load carriage, 14-month-olds were loaded with 15% of their body weight in shoulder-packs. Both symmetrical and asymmetrical loads disrupted alternating gait patterns and caused less mature footfall patterns.…

  8. Balancing Acts

    MedlinePlus

    ... a new type of balance therapy using computerized, virtual reality. UPMC associate professor Susan Whitney, Ph.D., ... involves simulated trips down the aisles of a virtual grocery store in the university's Medical Virtual Reality ...

  9. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Horizontal Stabilizing and Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and...

  10. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Horizontal Stabilizing and Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and...

  11. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Horizontal Stabilizing and Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and...

  12. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Horizontal Stabilizing and Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and...

  13. 14 CFR 23.423 - Maneuvering loads.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Structure Horizontal Stabilizing and Balancing Surfaces § 23.423 Maneuvering loads. Each horizontal surface and its supporting structure, and...

  14. Balance System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    TherEx Inc.'s AT-1 Computerized Ataxiameter precisely evaluates posture and balance disturbances that commonly accompany neurological and musculoskeletal disorders. Complete system includes two-strain gauged footplates, signal conditioning circuitry, a computer monitor, printer and a stand-alone tiltable balance platform. AT-1 serves as assessment tool, treatment monitor, and rehabilitation training device. It allows clinician to document quantitatively the outcome of treatment and analyze data over time to develop outcome standards for several classifications of patients. It can evaluate specifically the effects of surgery, drug treatment, physical therapy or prosthetic devices.

  15. Structural Integrity of a Wind Tunnel Balance

    NASA Technical Reports Server (NTRS)

    Karkehabadi, R.; Rhew, R. D.

    2004-01-01

    The National Aeronautics and Space Administration (NASA) Langley Research Center (LaRC) has been designing strain-gage balances for utilization in wind tunnels since its inception. The utilization of balances span over a wide variety of aerodynamic tests. A force balance is an inherently critically stressed component due to the requirements of measurement sensitivity. Research and analyses are done in order to investigate the structural integrity of the balances as well as developing an understanding of their performance in order to enhance their capability. Maximum loading occurs when all 6 components of the loads are applied simultaneously with their maximum value allowed (limit load). This circumstance normally does not occur in the wind tunnel. However, if it occurs, is the balance capable of handling the loads with an acceptable factor of safety? LaRC Balance 1621 was modeled and meshed in PATRAN for analysis in NASTRAN. For a complete analysis, it is necessary to consider all the load cases as well as use dense mesh near all the edges. Because of computer limitations, it is not possible to have one model with the dense mesh near all edges. In the present study, a dense mesh is limited to the surface corners where the cage and axial sections meet. Four different load combinations are used for the current analysis. Linear analysis is performed for each load case. In the case where the stress value is above linear elastic region, it is necessary to perform nonlinear analysis. It is also important to investigate the variables limiting the structural integrity of the balances. In order to investigate the possibility of modifying the existing balances to enhance the structural integrity, some modifications are done on this balance. The structural integrity of the balance after modification is investigated.

  16. Balancing Eggs

    ERIC Educational Resources Information Center

    Mills, Allan

    2014-01-01

    Theory predicts that an egg-shaped body should rest in stable equilibrium when on its side, balance vertically in metastable equilibrium on its broad end and be completely unstable on its narrow end. A homogeneous solid egg made from wood, clay or plastic behaves in this way, but a real egg will not stand on either end. It is shown that this…

  17. Balance (or Vestibular) Rehabilitation

    MedlinePlus

    ... the Public / Hearing and Balance Balance (or Vestibular) Rehabilitation Audiologic (hearing), balance, and medical diagnostic tests help ... whether you are a candidate for vestibular (balance) rehabilitation. Vestibular rehabilitation is an individualized balance retraining exercise ...

  18. Impacts of groundwater metal loads from bedrock fractures on water quality of a mountain stream.

    PubMed

    Caruso, Brian S; Dawson, Helen E

    2009-06-01

    Acid mine drainage and metal loads from hardrock mines to surface waters is a significant problem in the western USA and many parts of the world. Mines often occur in mountain environments with fractured bedrock aquifers that serve as pathways for metals transport to streams. This study evaluates impacts from current and potential future groundwater metal (Cd, Cu, and Zn) loads from fractures underlying the Gilt Edge Mine, South Dakota, on concentrations in Strawberry Creek using existing flow and water quality data and simple mixing/dilution mass balance models. Results showed that metal loads from bedrock fractures to the creek currently contribute <1% of total loads. Even if background water quality is achieved upstream in Strawberry Creek, fracture metal loads would be <5%. Fracture loads could increase substantially and cause stream water quality standards exceedances once groundwater with elevated metals concentrations in the aquifer matrix migrates to the fractures and discharges to the stream. Potential future metal loads from an upstream fracture would contribute a small proportion of the total load relative to current loads in the stream. Cd has the highest stream concentrations relative to standards. Even if all stream water was treated to remove 90% of the Cd, the standard would still not be achieved. At a fracture farther downstream, the Cd standard can only be met if the upstream water is treated achieving a 90% reduction in Cd concentrations and the median stream flow is maintained.

  19. Elastomeric load sharing device

    NASA Technical Reports Server (NTRS)

    Isabelle, Charles J. (Inventor); Kish, Jules G. (Inventor); Stone, Robert A. (Inventor)

    1992-01-01

    An elastomeric load sharing device, interposed in combination between a driven gear and a central drive shaft to facilitate balanced torque distribution in split power transmission systems, includes a cylindrical elastomeric bearing and a plurality of elastomeric bearing pads. The elastomeric bearing and bearing pads comprise one or more layers, each layer including an elastomer having a metal backing strip secured thereto. The elastomeric bearing is configured to have a high radial stiffness and a low torsional stiffness and is operative to radially center the driven gear and to minimize torque transfer through the elastomeric bearing. The bearing pads are configured to have a low radial and torsional stiffness and a high axial stiffness and are operative to compressively transmit torque from the driven gear to the drive shaft. The elastomeric load sharing device has spring rates that compensate for mechanical deviations in the gear train assembly to provide balanced torque distribution between complementary load paths of split power transmission systems.

  20. Watt and joule balances

    NASA Astrophysics Data System (ADS)

    Robinson, Ian A.

    2014-04-01

    prior to a decision on redefinition. The CCM had already recognized that agreement was close and has set in place a process whereby redefinition can take place by 2018. The final decision will be in the hands of the Conférence Générale des Poids et Mesures (CGPM) but the results reported here should aid a positive decision. Figure 1. Figure 1. Results from recent measurements of the Planck constant. The reference for the results h 90 is derived from the conventional values of the Josephson constant K J-90 and the von Klitzing constant R K-90. The factor of ten improvement in uncertainty of the NRC watt balance result, over that achieved by the same apparatus at NPL a few years earlier, can be understood as a factor of five improvement arising from the elimination of an effect discovered at NPL that could not be eliminated before shipment to Canada and a factor of two arising from the considerable improvements made by NRC. Once the kilogram has been redefined, the watt and joule balances will complete their transitions from instruments that are primarily of interest to the electrical community for determining the SI electrical units from the mechanical units, to the principal methods by which an individual National Measurement Institute (NMI) can make an independent determination of the SI unit of mass and thereby contribute to the maintenance of national and international mass scales. This special issue gives an introduction to the diversity of techniques which are required for the operation of watt and joule balances. However it does not contain a review of existing balances; this was a deliberate decision, as a number of such review papers have been published in the past five years [3-7] and it was felt that it was not yet time for another. The first technique considered is that of gravimetry; the watt balance measures the weight Mg of a mass M , and to convert the measured weight into a mass, the value of the acceleration due to gravity g must be known, at the

  1. Leadership and Work-Life Balance.

    PubMed

    Mattock, Sarah L

    2015-01-01

    Simply stated, work-life balance is something that is both difficult to define and difficult to achieve. Leaders, throughout the continuum of trauma care, need to have a sound understanding of what work-life balance means and set an example of a healthy work-life balance for those they lead. This article offers strategies for enhancing work-life balance and challenges individuals to use self-reflection as a means to furthering their personal and professional growth.

  2. Microprocessor-Controlled Laser Balancing System

    NASA Technical Reports Server (NTRS)

    Demuth, R. S.

    1985-01-01

    Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

  3. Balancing up and downregulation of the C. elegans X chromosomes

    PubMed Central

    Lau, Alyssa C.; Csankovszki, Györgyi

    2015-01-01

    In Caenorhabditis elegans, males have one X chromosome and hermaphrodites have two. Emerging evidence indicates that the male X is transcriptionally more active than autosomes to balance the single X to two sets of autosomes. Because upregulation is not limited to males, hermaphrodites need to strike back and downregulate expression from the two X chromosomes to balance gene expression in their genome. Hermaphrodite-specific downregulation involves binding of the dosage compensation complex to both Xs. Advances in recent years revealed that the action of the dosage compensation complex results in compaction of the X chromosomes, changes in the distribution of histone modifications, and ultimately limiting RNA Polymerase II loading to achieve chromosome-wide gene repression. PMID:25966908

  4. Wind tunnel balance

    NASA Technical Reports Server (NTRS)

    Horne, Warren L. (Inventor); Kunz, Nans (Inventor); Luna, Phillip M. (Inventor); Roberts, Andrew C. (Inventor); Smith, Kenneth M. (Inventor); Smith, Ronald C. (Inventor)

    1989-01-01

    A flow-through balance is provided which includes a non-metric portion and a metric portion which form a fluid-conducting passage in fluid communication with an internal bore in the sting. The non-metric and metric portions of the balance are integrally connected together by a plurality of flexure beams such that the non-metric portion, the metric portion and the flexure beams form a one-piece construction which eliminates mechanical hysteresis between the non-metric and the metric portion. The system includes structures for preventing the effects of temperature, pressure and pressurized fluid from producing asymmetric loads on the flexure beams. A temperature sensor and a pressure sensor are located within the fluid-conducting passage of the balance. The system includes a longitudinal bellows member connected at two ends to one of the non-metric portion and the metric portion and at an intermediate portion thereof to the other of (1) and (2). A plurality of strain gages are mounted on the flexure beams to measure strain forces on the flexure beams. The flexure beams are disposed so as to enable symmetric forces on the flexure beams to cancel out so that only asymmetric forces are measured as deviations by the strain gages.

  5. Load cell

    DOEpatents

    Spletzer, Barry L.

    1998-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

  6. Load cell

    DOEpatents

    Spletzer, B.L.

    1998-12-15

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

  7. Load cell

    DOEpatents

    Spletzer, Barry L.

    2001-01-01

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

  8. Power Balance Estimation in Long Duration Discharges on QUEST

    NASA Astrophysics Data System (ADS)

    Hanada, K.; Zushi, H.; Idei, H.; Nakamura, K.; Ishiguro, M.; Tashima, S.; I. Kalinnikova, E.; Nagashima, Y.; Hasegawa, M.; Fujisawa, A.; Higashijima, A.; Kawasaki, S.; Nakashima, H.; Mitarai, O.; Fukuyama, A.; Takase, Y.; Gao, X.; H., Liu; Qian, J.; Ono, M.; Raman, R.

    2016-11-01

    Fully non-inductive plasma start-up was successfully achieved by using a well-controlled microwave source on the spherical tokamak, QUEST. Non-inductive plasmas were maintained for approximately 3-5 min, during which time power balance estimates could be achieved by monitoring wall and cooling-water temperatures. Approximately 70%-90% of the injected power could be accounted for by calorimetric measurements and approximately half of the injected power was found to be deposited on the vessel wall, which is slightly dependent on the magnetic configuration. The power distribution to water-cooled limiters, which are expected to be exposed to local heat loads, depends significantly on the magnetic configuration, however some of the deposited power is due to energetic electrons, which have large poloidal orbits and are likely to be deposited on the plasma facing components.

  9. BAS: balanced acceptance sampling of natural resources.

    PubMed

    Robertson, B L; Brown, J A; McDonald, T; Jaksons, P

    2013-09-01

    To design an efficient survey or monitoring program for a natural resource it is important to consider the spatial distribution of the resource. Generally, sample designs that are spatially balanced are more efficient than designs which are not. A spatially balanced design selects a sample that is evenly distributed over the extent of the resource. In this article we present a new spatially balanced design that can be used to select a sample from discrete and continuous populations in multi-dimensional space. The design, which we call balanced acceptance sampling, utilizes the Halton sequence to assure spatial diversity of selected locations. Targeted inclusion probabilities are achieved by acceptance sampling. The BAS design is conceptually simpler than competing spatially balanced designs, executes faster, and achieves better spatial balance as measured by a number of quantities. The algorithm has been programed in an R package freely available for download.

  10. Reframing our pursuit of life balance.

    PubMed

    Fuentes, David G; Ogden, Rachel R; Ryan-Haddad, Ann; Strang, Aimee F

    2015-04-25

    During our time in the 2013 Academic Leadership Fellows Program, we explored what it takes to achieve life balance through a framework presented in a Harvard Business Review article. In this Statement, we describe 5 different areas from the article that provide infrastructure for reflecting on how we have learned to approach life balance in academia. We also provide brief messages based on this reading and others to help academics' pursuit of life balance.

  11. Reframing Our Pursuit of Life Balance

    PubMed Central

    Ogden, Rachel R.; Ryan-Haddad, Ann; Strang, Aimee F.

    2015-01-01

    During our time in the 2013 Academic Leadership Fellows Program, we explored what it takes to achieve life balance through a framework presented in a Harvard Business Review article. In this Statement, we describe 5 different areas from the article that provide infrastructure for reflecting on how we have learned to approach life balance in academia. We also provide brief messages based on this reading and others to help academics’ pursuit of life balance. PMID:25995509

  12. Field balancing in the real world

    SciTech Connect

    Bracher, B.

    1997-09-05

    Field balancing can achieve significant results when other problems are present in the frequency spectrum and multiple vibrations are evident in the waveform. Many references suggest eliminating other problems before attempting to balance. That`s great - if you can do it. There are valid reasons for this approach, and it would be much easier to balance machinery when other problems have been corrected. It is the theoretical ideal in field balancing. However, in the real world of machinery maintained for years by reacting to immediate problems, the classic vibration signature for unbalance is rarely seen. Maintenance personnel make most of their decisions with limited information. The decision to balance or not to balance is usually made the same way. This paper will demonstrate significant results of field balancing in the presence of multiple problems. By examining the data available and analyzing the probabilities, a reasonable chance for success can be assured.

  13. The Global Challenge: A Matter of Balance.

    ERIC Educational Resources Information Center

    Mulford, Bill

    2002-01-01

    Argues that global challenge created by the pressure for change requires educators to understand the balance between continuity and constant change dependence and independence, individualism and community, homogeneity and heterogeneity. To achieve balanced learning and development, education should place greater emphasis on continuity,…

  14. Balance Food and Activity

    MedlinePlus

    ... eNewsletters Calendar Balance Food and Activity What is Energy Balance? Energy is another word for "calories." Your ... adults, fewer calories are needed at older ages. Energy Balance in Real Life Think of it as ...

  15. Dizziness and Balance

    MedlinePlus

    AUDIOLOGY Dizziness and Balance Inform ation Seri es Our balance system helps us walk, run, and move without falling. ... if I have a problem with balance or dizziness? It is important to see your doctor if ...

  16. Automated load management for spacecraft power systems

    NASA Technical Reports Server (NTRS)

    Lollar, Louis F.

    1987-01-01

    An account is given of the results of a study undertaken by NASA's Marshall Space Flight Center to design and implement the load management techniques for autonomous spacecraft power systems, such as the Autonomously Managed Power System Test Facility. Attention is given to four load-management criteria, which encompass power bus balancing on multichannel power systems, energy balancing in such systems, power quality matching of loads to buses, and contingency load shedding/adding. Full implementation of these criteria calls for the addition of a second power channel.

  17. Split torque transmission load sharing

    NASA Technical Reports Server (NTRS)

    Krantz, T. L.; Rashidi, M.; Kish, J. G.

    1992-01-01

    Split torque transmissions are attractive alternatives to conventional planetary designs for helicopter transmissions. The split torque designs can offer lighter weight and fewer parts but have not been used extensively for lack of experience, especially with obtaining proper load sharing. Two split torque designs that use different load sharing methods have been studied. Precise indexing and alignment of the geartrain to produce acceptable load sharing has been demonstrated. An elastomeric torque splitter that has large torsional compliance and damping produces even better load sharing while reducing dynamic transmission error and noise. However, the elastomeric torque splitter as now configured is not capable over the full range of operating conditions of a fielded system. A thrust balancing load sharing device was evaluated. Friction forces that oppose the motion of the balance mechanism are significant. A static analysis suggests increasing the helix angle of the input pinion of the thrust balancing design. Also, dynamic analysis of this design predicts good load sharing and significant torsional response to accumulative pitch errors of the gears.

  18. Automatic load sharing in inverter modules

    NASA Technical Reports Server (NTRS)

    Nagano, S.

    1979-01-01

    Active feedback loads transistor equally with little power loss. Circuit is suitable for balancing modular inverters in spacecraft, computer power supplies, solar-electric power generators, and electric vehicles. Current-balancing circuit senses differences between collector current for power transistor and average value of load currents for all power transistors. Principle is effective not only in fixed duty-cycle inverters but also in converters operating at variable duty cycles.

  19. Resource Balancing Control Allocation

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Bodson, Marc

    2010-01-01

    Next generation aircraft with a large number of actuators will require advanced control allocation methods to compute the actuator commands needed to follow desired trajectories while respecting system constraints. Previously, algorithms were proposed to minimize the l1 or l2 norms of the tracking error and of the control effort. The paper discusses the alternative choice of using the l1 norm for minimization of the tracking error and a normalized l(infinity) norm, or sup norm, for minimization of the control effort. The algorithm computes the norm of the actuator deflections scaled by the actuator limits. Minimization of the control effort then translates into the minimization of the maximum actuator deflection as a percentage of its range of motion. The paper shows how the problem can be solved effectively by converting it into a linear program and solving it using a simplex algorithm. Properties of the algorithm are investigated through examples. In particular, the min-max criterion results in a type of resource balancing, where the resources are the control surfaces and the algorithm balances these resources to achieve the desired command. A study of the sensitivity of the algorithms to the data is presented, which shows that the normalized l(infinity) algorithm has the lowest sensitivity, although high sensitivities are observed whenever the limits of performance are reached.

  20. Balance in Assessment

    ERIC Educational Resources Information Center

    White, Richard

    2007-01-01

    The review by Black and Wiliam of national systems makes clear the complexity of assessment, and identifies important issues. One of these is "balance": balance between local and central responsibilities, balance between the weights given to various purposes of schooling, balance between weights for various functions of assessment, and balance…

  1. A Question of Balance

    ERIC Educational Resources Information Center

    Claxton, David B.; Troy, Maridy; Dupree, Sarah

    2006-01-01

    Most authorities consider balance to be a component of skill-related physical fitness. Balance, however, is directly related to health, especially for older adults. Falls are a leading cause of injury and death among the elderly. Improved balance can help reduce falls and contribute to older people remaining physically active. Balance is a…

  2. Dynamic balance improvement program

    NASA Technical Reports Server (NTRS)

    Butner, M. F.

    1983-01-01

    The reduction of residual unbalance in the space shuttle main engine (SSME) high pressure turbopump rotors was addressed. Elastic rotor response to unbalance and balancing requirements, multiplane and in housing balancing, and balance related rotor design considerations were assessed. Recommendations are made for near term improvement of the SSME balancing and for future study and development efforts.

  3. Balancing Vanguard Satellites

    NASA Technical Reports Server (NTRS)

    Simkovich, A.; Baumann, Robert C.

    1961-01-01

    The Vanguard satellites and component parts were balanced within the specified limits by using a Gisholt Type-S balancer in combination with a portable International Research and Development vibration analyzer and filter, with low-frequency pickups. Equipment and procedures used for balancing are described; and the determination of residual imbalance is accomplished by two methods: calculation, and graphical interpretation. Between-the-bearings balancing is recommended for future balancing of payloads.

  4. Relative Harmony: Achieving Balance in Your Brand Family

    ERIC Educational Resources Information Center

    Collins, Mary Ellen

    2011-01-01

    Educational institutions understand the importance of having a positive image among their target audiences, but the process of creating, enhancing, and managing that image remains challenging to many. Confusion over what branding is only adds to the challenge. Consultants define "brand" as promising an experience and delivering on that…

  5. Feedback and assessment for clinical placements: achieving the right balance

    PubMed Central

    Burgess, Annette; Mellis, Craig

    2015-01-01

    During clinical placements, the provision of feedback forms an integral part of the learning process and enriches students’ learning experiences. The purpose of feedback is to improve the learner’s knowledge, skills, or behavior. Receipt of accurate feedback can help to narrow the gap between actual and desired performance. Effective and regular feedback has the potential to reinforce good practice and motivate the learner toward the desired outcome. Despite the obvious role of feedback in effective teaching and learning, a common complaint from students is that they do not receive adequate feedback. Unfortunately, skills in giving and receiving feedback are rarely taught to students or clinicians. This study aims to provide an understanding of the role of feedback within the learning process, consider consequences of inadequate or poorly given feedback, consider the barriers to the feedback process, provide practical guidelines for providing feedback, and consider the need for student and faculty development in feedback skills. PMID:26056511

  6. Calcium and Calcium Supplements: Achieving the Right Balance

    MedlinePlus

    ... be found in a variety of foods, including: Dairy products, such as cheese, milk and yogurt Dark green ... a vegan diet Have lactose intolerance and limit dairy products Consume large amounts of protein or sodium, which ...

  7. Focus on the Future: Achieving Balance in Career & Life Integration.

    ERIC Educational Resources Information Center

    Walz, Garry R., Ed.; Knowdell, Richard, Ed.

    This book contains conference papers from the 2000 International Career Development Conference. The intent is to broaden the dissemination of the ideas presented at the conference, and to provide the authors with an international platform for communicating their ideas. The presentations include the following: (1) "Retaining Knowledge Workers:…

  8. The Right Balance: Helping Cancer Survivors Achieve a Healthy Weight

    Cancer.gov

    An article about interventions that aim to help survivors maintain a healthy weight to reduce the risk of cancer recurrence and death and decrease the likelihood of chronic and late effects of cancer treatment.

  9. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Gust loads. 23.425 Section 23.425 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must...

  10. 14 CFR 23.425 - Gust loads.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Balancing Surfaces § 23.425 Gust loads. (a) Each horizontal surface, other than a main wing, must be designed for loads resulting from— (1) Gust velocities specified in § 23.333(c) with flaps retracted; and... unaccelerated flight at the pertinent design speeds VF, VC, and VD must first be determined. The...

  11. Modeling efficiency and water balance in PEM fuel cell systems with liquid fuel processing and hydrogen membranes

    NASA Astrophysics Data System (ADS)

    Pearlman, Joshua B.; Bhargav, Atul; Shields, Eric B.; Jackson, Gregory S.; Hearn, Patrick L.

    Integrating PEM fuel cells effectively with liquid hydrocarbon reforming requires careful system analysis to assess trade-offs associated with H 2 production, purification, and overall water balance. To this end, a model of a PEM fuel cell system integrated with an autothermal reformer for liquid hydrocarbon fuels (modeled as C 12H 23) and with H 2 purification in a water-gas-shift/membrane reactor is developed to do iterative calculations for mass, species, and energy balances at a component and system level. The model evaluates system efficiency with parasitic loads (from compressors, pumps, and cooling fans), system water balance, and component operating temperatures/pressures. Model results for a 5-kW fuel cell generator show that with state-of-the-art PEM fuel cell polarization curves, thermal efficiencies >30% can be achieved when power densities are low enough for operating voltages >0.72 V per cell. Efficiency can be increased by operating the reformer at steam-to-carbon ratios as high as constraints related to stable reactor temperatures allow. Decreasing ambient temperature improves system water balance and increases efficiency through parasitic load reduction. The baseline configuration studied herein sustained water balance for ambient temperatures ≤35 °C at full power and ≤44 °C at half power with efficiencies approaching ∼27 and ∼30%, respectively.

  12. Weight/balance portable test equipment

    SciTech Connect

    Whitlock, R.W.

    1994-11-03

    This document shows the general layout, and gives a part description for the weight/balance test equipment. This equipment will aid in the regulation of the leachate loading of tanker trucks. The report contains four drawings with part specifications. The leachate originates from lined trenches.

  13. Stepwise Regression Analysis of MDOE Balance Calibration Data Acquired at DNW

    NASA Technical Reports Server (NTRS)

    DeLoach, RIchard; Philipsen, Iwan

    2007-01-01

    This paper reports a comparison of two experiment design methods applied in the calibration of a strain-gage balance. One features a 734-point test matrix in which loads are varied systematically according to a method commonly applied in aerospace research and known in the literature of experiment design as One Factor At a Time (OFAT) testing. Two variations of an alternative experiment design were also executed on the same balance, each with different features of an MDOE experiment design. The Modern Design of Experiments (MDOE) is an integrated process of experiment design, execution, and analysis applied at NASA's Langley Research Center to achieve significant reductions in cycle time, direct operating cost, and experimental uncertainty in aerospace research generally and in balance calibration experiments specifically. Personnel in the Instrumentation and Controls Department of the German Dutch Wind Tunnels (DNW) have applied MDOE methods to evaluate them in the calibration of a balance using an automated calibration machine. The data have been sent to Langley Research Center for analysis and comparison. This paper reports key findings from this analysis. The chief result is that a 100-point calibration exploiting MDOE principles delivered quality comparable to a 700+ point OFAT calibration with significantly reduced cycle time and attendant savings in direct and indirect costs. While the DNW test matrices implemented key MDOE principles and produced excellent results, additional MDOE concepts implemented in balance calibrations at Langley Research Center are also identified and described.

  14. SSME alternate turbopump (pump section) axial load analysis

    NASA Technical Reports Server (NTRS)

    Crease, G. A.; Rosello, A., Jr.; Fetfatsidis, A. K.

    1989-01-01

    A flow balancing computer program constructed to calculate the axial loads on the Space Shuttle Main Engine (SSME) alternate turbopumps (ATs) pump sections are described. The loads are used in turn to determine load balancing piston design requirements. The application of the program to the inlet section, inducer/impeller/stage, bearings, seals, labyrinth, damper, piston, face and corner, and stationary/rotating surfaces is indicated. Design analysis results are reported which show that the balancing piston's designs are adequate and that performance and life will not be degraded by the turbopump's axial load characteristics.

  15. Exercise for Mild Balance Dysfunction: Research into Practice.

    PubMed

    Williams, Susan; Meyer, Claudia; Batchelor, Frances; Hill, Keith

    2015-10-01

    The objective of this study was to determine whether improved balance outcomes achieved in a randomized controlled trial (RCT) using balance screening to identify mild balance dysfunction and home exercises could be translated into community settings. Community-dwelling people aged over 65 who expressed concerns about their balance, had less than two falls in the preceding 12 months, and who had mild balance impairment on screening were given an individualized home-based balance and strengthening exercise program with intermittent home-visit support by a physiotherapist. Of 71 participants assessed (mean age 77.3 years, 76% female), 58 (82%) completed the six-month intervention. Twenty six percent of participants regained balance performance within normal limits--similar to those achieved in the previous RCT. Successful results from a previous RCT were able to be translated into community settings, with a similar magnitude of effect on balance and mobility.

  16. Inducer Hydrodynamic Load Measurement Devices

    NASA Technical Reports Server (NTRS)

    Skelley, Stephen E.; Zoladz, Thomas F.

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This "rotating balance" was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  17. Inducer Hydrodynamic Load Measurement Devices

    NASA Technical Reports Server (NTRS)

    Skelley, Stephen E.; Zoladz, Thomas F.; Turner, Jim (Technical Monitor)

    2002-01-01

    Marshall Space Flight Center (MSFC) has demonstrated two measurement devices for sensing and resolving the hydrodynamic loads on fluid machinery. The first - a derivative of the six-component wind tunnel balance - senses the forces and moments on the rotating device through a weakened shaft section instrumented with a series of strain gauges. This rotating balance was designed to directly measure the steady and unsteady hydrodynamic loads on an inducer, thereby defining both the amplitude and frequency content associated with operating in various cavitation modes. The second device - a high frequency response pressure transducer surface mounted on a rotating component - was merely an extension of existing technology for application in water. MSFC has recently completed experimental evaluations of both the rotating balance and surface-mount transducers in a water test loop. The measurement bandwidth of the rotating balance was severely limited by the relative flexibility of the device itself, resulting in an unexpectedly low structural bending mode and invalidating the higher-frequency response data. Despite these limitations, measurements confirmed that the integrated loads on the four-bladed inducer respond to both cavitation intensity and cavitation phenomena. Likewise, the surface-mount pressure transducers were subjected to a range of temperatures and flow conditions in a non-rotating environment to record bias shifts and transfer functions between the transducers and a reference device. The pressure transducer static performance was within manufacturer's specifications and dynamic response accurately followed that of the reference.

  18. Occlusal cranial balancing technique.

    PubMed

    Smith, Gerald H

    2007-01-01

    The acronym for Occlusal Cranial Balancing Technique is OCB. The OCB concept is based on the architectural principle of a level foundation. The principles of Occlusal Cranial Balancing are a monumental discovery and if applied will enhance total body function.

  19. Skylab water balance analysis

    NASA Technical Reports Server (NTRS)

    Leonard, J. I.

    1977-01-01

    The water balance of the Skylab crew was analyzed. Evaporative water loss using a whole body input/output balance equation, water, body tissue, and energy balance was analyzed. The approach utilizes the results of several major Skylab medical experiments. Subsystems were designed for the use of the software necessary for the analysis. A partitional water balance that graphically depicts the changes due to water intake is presented. The energy balance analysis determines the net available energy to the individual crewman during any period. The balances produce a visual description of the total change of a particular body component during the course of the mission. The information is salvaged from metabolic balance data if certain techniques are used to reduce errors inherent in the balance method.

  20. Polarization-balanced beamsplitter

    DOEpatents

    Decker, Derek E.

    1998-01-01

    A beamsplitter assembly that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting.

  1. Polarization-balanced beamsplitter

    DOEpatents

    Decker, D.E.

    1998-02-17

    A beamsplitter assembly is disclosed that includes several beamsplitter cubes arranged to define a plurality of polarization-balanced light paths. Each polarization-balanced light path contains one or more balanced pairs of light paths, where each balanced pair of light paths includes either two transmission light paths with orthogonal polarization effects or two reflection light paths with orthogonal polarization effects. The orthogonal pairing of said transmission and reflection light paths cancels polarization effects otherwise caused by beamsplitting. 10 figs.

  2. 1994 Pacific Northwest Loads and Resources Study.

    SciTech Connect

    United States. Bonneville Power Administration.

    1994-12-01

    The 1994 Pacific Northwest Loads and Resources Study presented herein establishes a picture of how the agency is positioned today in its loads and resources balance. It is a snapshot of expected resource operation, contractual obligations, and rights. This study does not attempt to present or analyze future conservation or generation resource scenarios. What it does provide are base case assumptions from which scenarios encompassing a wide range of uncertainties about BPA`s future may be evaluated. The Loads and Resources Study is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates the 1993 Pacific Northwest Loads and Resources Study, published in December 1993. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The Federal system and regional analyses for medium load forecast are presented.

  3. Thermal balance in convective therapies.

    PubMed

    Santoro, Antonio; Mancini, Elena; Canova, Cristina; Mambelli, Emanuele

    2003-08-01

    Among the factors causing intradialytic haemodynamic instability, dialysate temperature has been shown to play a relevant role. An improved cardiovascular response during isolated ultrafiltration or with cooled dialysate has been described in the past. Cold dialysate may increase the external heat loss compensating for the increase in core temperature, thus avoiding vasodilatation, but it also increases myocardial contractility. However, a better haemodynamic response to dialysis treatment has long been known in convective therapies as well, and the hypothesis of a leading role for thermal balance is under discussion. In conventional haemofiltration (HF), venous blood cooling is expected, on the basis of the infusate temperature and the filtration fraction. In on-line HF, the infusate temperature and its volume may have a different impact on thermal balance depending on the site of infusion (pre- or post-dialyser). In an in vitro study comparing haemodialysis (HD) (conventional HD, dialysate 37 degrees C; and cold HD, dialysate 35.5 degrees C) with HF (pre- and post-dilution, 37 degrees C), we observed a more negative thermal balance with cold HD (-130 kJ/h) and with post-dilution HF (-75 kJ/h). The beneficial pressor effects of HF have been confirmed even in on-line HF, which actually has very few differences in the thermal balance compared with conventional HD (dialysate 37 degrees C). In on-line HF, the amount of warm infusion, often exceeding the blood flow, makes the achievement of a negative thermal balance highly unlikely. Thus, there is not sufficient evidence that vascular stability in on-line HF is solely related to different thermal energy balances. Other factors playing a relevant role in the cardiocirculatory response to convective dialysis should thus be considered.

  4. Wind Tunnel Balances

    NASA Technical Reports Server (NTRS)

    Warner, Edward P; Norton, F H

    1920-01-01

    Report embodies a description of the balance designed and constructed for the use of the National Advisory Committee for Aeronautics at Langley Field, and also deals with the theory of sensitivity of balances and with the errors to which wind tunnel balances of various types are subject.

  5. Coaching for Balance.

    ERIC Educational Resources Information Center

    Larson, Bonnie

    2001-01-01

    Discusses coaching for balance the integration of the whole self: physical (body), intellectual (mind), spiritual (soul), and emotional (heart). Offers four ways to identify problems and tell whether someone is out of balance and four coaching techniques for creating balance. (Contains 11 references.) (JOW)

  6. Human Balance System

    MedlinePlus

    ... and vision problems, and difficulty with concentration and memory. What is balance? Balance is the ability to maintain the body’s center of mass over its base of support. 1 A properly functioning balance system allows humans to see clearly while moving, identify orientation with ...

  7. Model-based Assessment for Balancing Privacy Requirements and Operational Capabilities

    SciTech Connect

    Knirsch, Fabian; Engel, Dominik; Frincu, Marc; Prasanna, Viktor

    2015-02-17

    The smart grid changes the way energy is produced and distributed. In addition both, energy and information is exchanged bidirectionally among participating parties. Therefore heterogeneous systems have to cooperate effectively in order to achieve a common high-level use case, such as smart metering for billing or demand response for load curtailment. Furthermore, a substantial amount of personal data is often needed for achieving that goal. Capturing and processing personal data in the smart grid increases customer concerns about privacy and in addition, certain statutory and operational requirements regarding privacy aware data processing and storage have to be met. An increase of privacy constraints, however, often limits the operational capabilities of the system. In this paper, we present an approach that automates the process of finding an optimal balance between privacy requirements and operational requirements in a smart grid use case and application scenario. This is achieved by formally describing use cases in an abstract model and by finding an algorithm that determines the optimum balance by forward mapping privacy and operational impacts. For this optimal balancing algorithm both, a numeric approximation and – if feasible – an analytic assessment are presented and investigated. The system is evaluated by applying the tool to a real-world use case from the University of Southern California (USC) microgrid.

  8. Reconceptualizing balance: attributes associated with balance performance.

    PubMed

    Thomas, Julia C; Odonkor, Charles; Griffith, Laura; Holt, Nicole; Percac-Lima, Sanja; Leveille, Suzanne; Ni, Pensheng; Latham, Nancy K; Jette, Alan M; Bean, Jonathan F

    2014-09-01

    Balance tests are commonly used to screen for impairments that put older adults at risk for falls. The purpose of this study was to determine the attributes that were associated with balance performance as measured by the Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) balance test. This study was a cross-sectional secondary analysis of baseline data from a longitudinal cohort study, the Boston Rehabilitative Impairment Study of the Elderly (Boston RISE). Boston RISE was performed in an outpatient rehabilitation research center and evaluated Boston area primary care patients aged 65 to 96 (N=364) with self-reported difficulty or task-modification climbing a flight of stairs or walking 1/2 of a mile. The outcome measure was standing balance as measured by the FICSIT-4 balance assessment. Other measures included: self-efficacy, pain, depression, executive function, vision, sensory loss, reaction time, kyphosis, leg range of motion, trunk extensor muscle endurance, leg strength and leg velocity at peak power. Participants were 67% female, had an average age of 76.5 (±7.0) years, an average of 4.1 (±2.0) chronic conditions, and an average FICSIT-4 score of 6.7 (±2.2) out of 9. After adjusting for age and gender, attributes significantly associated with balance performance were falls self-efficacy, trunk extensor muscle endurance, sensory loss, and leg velocity at peak power. FICSIT-4 balance performance is associated with a number of behavioral and physiologic attributes, many of which are amenable to rehabilitative treatment. Our findings support a consideration of balance as multidimensional activity as proposed by the current International Classification of Functioning, Disability, and Health (ICF) model.

  9. LOADING DEVICE

    DOEpatents

    Ohlinger, L.A.

    1958-10-01

    A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

  10. Optimal Load Control via Frequency Measurement and Neighborhood Area Communication

    SciTech Connect

    Zhao, CH; Topcu, U; Low, SH

    2013-11-01

    We propose a decentralized optimal load control scheme that provides contingency reserve in the presence of sudden generation drop. The scheme takes advantage of flexibility of frequency responsive loads and neighborhood area communication to solve an optimal load control problem that balances load and generation while minimizing end-use disutility of participating in load control. Local frequency measurements enable individual loads to estimate the total mismatch between load and generation. Neighborhood area communication helps mitigate effects of inconsistencies in the local estimates due to frequency measurement noise. Case studies show that the proposed scheme can balance load with generation and restore the frequency within seconds of time after a generation drop, even when the loads use a highly simplified power system model in their algorithms. We also investigate tradeoffs between the amount of communication and the performance of the proposed scheme through simulation-based experiments.

  11. Carbohydrate Loading.

    ERIC Educational Resources Information Center

    Csernus, Marilyn

    Carbohydrate loading is a frequently used technique to improve performance by altering an athlete's diet. The objective is to increase glycogen stored in muscles for use in prolonged strenuous exercise. For two to three days, the athlete consumes a diet that is low in carbohydrates and high in fat and protein while continuing to exercise and…

  12. Graded Achievement, Tested Achievement, and Validity

    ERIC Educational Resources Information Center

    Brookhart, Susan M.

    2015-01-01

    Twenty-eight studies of grades, over a century, were reviewed using the argument-based approach to validity suggested by Kane as a theoretical framework. The review draws conclusions about the meaning of graded achievement, its relation to tested achievement, and changes in the construct of graded achievement over time. "Graded…

  13. Analysis of Sting Balance Calibration Data Using Optimized Regression Models

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.; Bader, Jon B.

    2010-01-01

    Calibration data of a wind tunnel sting balance was processed using a candidate math model search algorithm that recommends an optimized regression model for the data analysis. During the calibration the normal force and the moment at the balance moment center were selected as independent calibration variables. The sting balance itself had two moment gages. Therefore, after analyzing the connection between calibration loads and gage outputs, it was decided to choose the difference and the sum of the gage outputs as the two responses that best describe the behavior of the balance. The math model search algorithm was applied to these two responses. An optimized regression model was obtained for each response. Classical strain gage balance load transformations and the equations of the deflection of a cantilever beam under load are used to show that the search algorithm s two optimized regression models are supported by a theoretical analysis of the relationship between the applied calibration loads and the measured gage outputs. The analysis of the sting balance calibration data set is a rare example of a situation when terms of a regression model of a balance can directly be derived from first principles of physics. In addition, it is interesting to note that the search algorithm recommended the correct regression model term combinations using only a set of statistical quality metrics that were applied to the experimental data during the algorithm s term selection process.

  14. Study and Analyses on the Structural Performance of a Balance

    NASA Technical Reports Server (NTRS)

    Karkehabadi, R.; Rhew, R. D.; Hope, D. J.

    2004-01-01

    Strain-gauge balances for use in wind tunnels have been designed at Langley Research Center (LaRC) since its inception. Currently Langley has more than 300 balances available for its researchers. A force balance is inherently a critically stressed component due to the requirements of measurement sensitivity. The strain-gauge balances have been used in Langley s wind tunnels for a wide variety of aerodynamic tests, and the designs encompass a large array of sizes, loads, and environmental effects. There are six degrees of freedom that a balance has to measure. The balance s task to measure these six degrees of freedom has introduced challenging work in transducer development technology areas. As the emphasis increases on improving aerodynamic performance of all types of aircraft and spacecraft, the demand for improved balances is at the forefront. Force balance stress analysis and acceptance criteria are under review due to LaRC wind tunnel operational safety requirements. This paper presents some of the analyses and research done at LaRC that influence structural integrity of the balances. The analyses are helpful in understanding the overall behavior of existing balances and can be used in the design of new balances to enhance performance. Initially, a maximum load combination was used for a linear structural analysis. When nonlinear effects were encountered, the analysis was extended to include nonlinearities using MSC.Nastran . Because most of the balances are designed using Pro/Mechanica , it is desirable and efficient to use Pro/Mechanica for stress analysis. However, Pro/Mechanica is limited to linear analysis. Both Pro/Mechanica and MSC.Nastran are used for analyses in the present work. The structural integrity of balances and the possibility of modifying existing balances to enhance structural integrity are investigated.

  15. Balancing Conflicting Requirements for Grid and Particle Decomposition in Continuum-Lagrangian Solvers

    SciTech Connect

    Sitaraman, Hariswaran; Grout, Ray

    2015-10-30

    The load balancing strategies for hybrid solvers that involve grid based partial differential equation solution coupled with particle tracking are presented in this paper. A typical Message Passing Interface (MPI) based parallelization of grid based solves are done using a spatial domain decomposition while particle tracking is primarily done using either of the two techniques. One of the techniques is to distribute the particles to MPI ranks to whose grid they belong to while the other is to share the particles equally among all ranks, irrespective of their spatial location. The former technique provides spatial locality for field interpolation but cannot assure load balance in terms of number of particles, which is achieved by the latter. The two techniques are compared for a case of particle tracking in a homogeneous isotropic turbulence box as well as a turbulent jet case. We performed a strong scaling study for more than 32,000 cores, which results in particle densities representative of anticipated exascale machines. The use of alternative implementations of MPI collectives and efficient load equalization strategies are studied to reduce data communication overheads.

  16. LOADED WAVEGUIDES

    DOEpatents

    Mullett, L.B.; Loach, B.G.; Adams, G.L.

    1958-06-24

    >Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

  17. Linear and Nonlinear Analyses of a Wind-Tunnel Balance

    NASA Technical Reports Server (NTRS)

    Karkehabadi, R.; Rhew, R. D.

    2004-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gauge balances for utilization in wind tunnels since its inception. The utilization of balances span a wide variety of aerodynamic tests. A force balance is an inherently critically stressed component due to the requirements of measurement sensitivity. Force balance stress analysis and acceptance criteria are under review due to LaRC wind tunnel operational safety requirements. This paper presents some of the analyses done at NASA LaRC. Research and analyses were performed in order to investigate the structural integrity of the balances and better understand their performance. The analyses presented in this paper are helpful in understanding the overall behavior of an existing balance and can also be used in design of new balances to enhance their performance. As a first step, maximum load combination is used for linear structural analysis. When nonlinear effects are encountered, the analysis is extended to include the nonlinearities. Balance 1621 is typical for LaRC designed balances and was chosen for this study due to its traditional high load capacity, Figure 1. Maximum loading occurs when all 6 components are applied simultaneously with their maximum value allowed (limit load). This circumstance normally will not occur in the wind tunnel. However, if it occurs, is the balance capable of handling the loads with an acceptable factor of safety? Preliminary analysis using Pro/Mechanica indicated that this balance might experience nonlinearity. It was decided to analyze this balance by using NASTRAN so that a nonlinear analysis could be conducted. Balance 1621 was modeled and meshed in PATRAN for analysis in NASTRAN. The model from PATRAN/NASTRAN is compared to the one from Pro/Mechanica. For a complete analysis, it is necessary to consider all the load cases as well as use a dense mesh near all the edges. Because of computer limitations, it is not feasible to analyze model with the dense mesh near

  18. Understanding basic carbohydrate counting, glycemic index, and glycemic load for improved glycemic control in Hispanic patients with type 2 diabetes mellitus.

    PubMed

    Ortiz, Lidia Guadalupe Compeán; Berry, Diane C; Ruiz, Octelina Castillo; González, Eunice Reséndiz; Pérez, Paulina Aguilera; Rivas, Elva Del Ángel

    2014-01-01

    Hispanic patients with type 2 diabetes mellitus generally have poor glycemic control. Constant hyperglycemia in individuals with type 2 diabetes can cause microvascular and macrovascular complications that lead to early morbidity and mortality. Good glycemic control requires a balance between diet, exercise, and medication, but dietary balance is difficult to achieve for many patients. Of the macronutrients, carbohydrates mostly affect blood glucose levels. Basic carbohydrate counting, glycemic index, and glycemic load are important tools for patients to master to control their blood glucose levels.

  19. Identifying Balance in a Balanced Scorecard System

    ERIC Educational Resources Information Center

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of…

  20. Judicial Checks and Balances

    ERIC Educational Resources Information Center

    La Porta, Rafael; Lopez-de-Silanes, Florencio; Pop-Eleches, Cristian; Shleifer, Andrei

    2004-01-01

    In the Anglo-American constitutional tradition, judicial checks and balances are often seen as crucial guarantees of freedom. Hayek distinguishes two ways in which the judiciary provides such checks and balances: judicial independence and constitutional review. We create a new database of constitutional rules in 71 countries that reflect these…

  1. Leadership: A Balancing Act

    ERIC Educational Resources Information Center

    Hines, Thomas E.

    2011-01-01

    Maintaining balance in leadership can be difficult because balance is affected by the personality, strengths, and attitudes of the leader as well as the complicated environment within and outside the community college itself. This article explores what being a leader at the community college means, what the threats are to effective leadership, and…

  2. A Balance of Power?

    ERIC Educational Resources Information Center

    Mosey, Edward

    1991-01-01

    The booming economy of the Pacific Northwest region promotes the dilemma of balancing the need for increased electrical power with the desire to maintain that region's unspoiled natural environment. Pertinent factors discussed within the balance equation are population trends, economic considerations, industrial power requirements, and…

  3. Chemical Equation Balancing.

    ERIC Educational Resources Information Center

    Blakley, G. R.

    1982-01-01

    Reviews mathematical techniques for solving systems of homogeneous linear equations and demonstrates that the algebraic method of balancing chemical equations is a matter of solving a system of homogeneous linear equations. FORTRAN programs using this matrix method to chemical equation balancing are available from the author. (JN)

  4. A smartphone inertial balance

    NASA Astrophysics Data System (ADS)

    Barrera-Garrido, Azael

    2017-04-01

    In order to measure the mass of an object in the absence of gravity, one useful tool for many decades has been the inertial balance. One of the simplest forms of inertial balance is made by two mass holders or pans joined together with two stiff metal plates, which act as springs.

  5. Fifty years of genetic load

    SciTech Connect

    Wallace, B.

    1991-01-01

    This book discusses the radiation effects on Drosophila. It was originally thought that irradiating Drosophila would decrease the average fitness of the population, thereby leading to information about the detrimental effects of mutations. Surprisingly, the fitness of the irradiated population turned out to be higher than that of the control population. The original motivation for the experiment was as a test of genetic load theory. The average fitness of a population is depressed by deleterious alleles held in the population by the balance between mutation and natural selection. The depression is called the genetic load of the population. The load dose not depend on the magnitude of the deleterious effect of alleles, but only on the mutation rate.

  6. Load Dependency of Postural Control - Kinematic and Neuromuscular Changes in Response to over and under Load Conditions

    PubMed Central

    Ritzmann, Ramona; Freyler, Kathrin; Weltin, Elmar; Krause, Anne; Gollhofer, Albert

    2015-01-01

    Introduction Load variation is associated with changes in joint torque and compensatory reflex activation and thus, has a considerable impact on balance control. Previous studies dealing with over (OL) and under loading (UL) used water buoyancy or additional weight with the side effects of increased friction and inertia, resulting in substantially modified test paradigms. The purpose of this study was to identify gravity-induced load dependency of postural control in comparable experimental conditions and to determine the underlying neuromuscular mechanisms. Methods Balance performance was recorded under normal loading (NL, 1g), UL (0.16g; 0.38g) and OL (1.8g) in monopedal stance. Center of pressure (COP) displacement and frequency distribution (low 0.15-0.5Hz (LF), medium 0.5-2Hz (MF), high 2-6Hz (HF)) as well as ankle, knee and hip joint kinematics were assessed. Soleus spinal excitability was determined by H/M-recruitment curves (H/M-ratios). Results Compared to NL, OL caused an increase in ankle joint excursion, COP HF domain and H/M-ratio. Concomitantly, hip joint excursion and COP LF decreased. Compared to NL, UL caused modulations in the opposite direction: UL decreased ankle joint excursions, COP HF and H/M-ratio. Collaterally, hip joint excursion and COP LF increased. COP was augmented both in UL and in OL compared to NL. Conclusion Subjects achieved postural stability in OL and UL with greater difficulty compared to NL. Reduced postural control was accompanied by modified balance strategies and compensatory reflex activation. With increasing load, a shift from hip to ankle strategy was observed. Accompanying, COP frequency distribution shifted from LF to HF and spinal excitability was enhanced. It is suggested that in OL, augmented ankle joint torques are compensated by quick reflex-induced postural reactions in distal muscles. Contrarily, UL is associated with diminished joint torques and thus, postural equilibrium may be controlled by the proximal

  7. Load cell having strain gauges of arbitrary location

    DOEpatents

    Spletzer, Barry

    2007-03-13

    A load cell utilizes a plurality of strain gauges mounted upon the load cell body such that there are six independent load-strain relations. Load is determined by applying the inverse of a load-strain sensitivity matrix to a measured strain vector. The sensitivity matrix is determined by performing a multivariate regression technique on a set of known loads correlated to the resulting strains. Temperature compensation is achieved by configuring the strain gauges as co-located orthogonal pairs.

  8. Dilemmas in Balancing a University Literature Collection

    ERIC Educational Resources Information Center

    Isaacson, David

    2004-01-01

    This essay explores some of the conflicts faced by the author, a liaison with book-selection responsibilities to a university English Department. These conflicts include: trying to fill gaps missed by profiles set up with our book vendor; trying to achieve a reasonable balance between canonical and non-canonical texts; between primary texts and…

  9. Balancing Certainty and Uncertainty in Clinical Practice

    ERIC Educational Resources Information Center

    Kamhi, Alan G.

    2011-01-01

    Purpose: In this article, I question how practitioners can balance the certainty and confidence that they can help their patients with the uncertainty that makes them continually question their beliefs and assumptions. Method: I compare the mechanisms of science and models of clinical practice that may help practitioners achieve the right balance…

  10. Active balance system and vibration balanced machine

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  11. Load Balancing in Stochastic Networks: Algorithms, Analysis, and Game Theory

    DTIC Science & Technology

    2014-04-16

    expansion. How 41 44 do these results change with general service times or heterogeneous service times? Is it possible to provide an incentive that will move...opinions and/or findings contained in this report are those of the author(s) and should not contrued as an official Department of the Army position...geometric with parameter ?, and thus has an exponential decay rate. When d ? 2, the model is not exactly solvable, but asymptotic results show that as n

  12. Query Optimization in Distributed Databases through Load Balancing.

    DTIC Science & Technology

    1986-08-06

    bound solution methods to the 0-1 integer programming problem. Although their approaches were more efficient, they still required about a second of...return to the value that it had before the large increase). We did -.- not carry out sufficiently long measurements to feel confident enough to draw any...easily implemented in such a system, we can be more confident that we can adapt them to less sophisticated DDBMS’s. Furthermore, a lot of effort has been

  13. Consideration of Dynamical Balances

    NASA Technical Reports Server (NTRS)

    Errico, Ronald M.

    2015-01-01

    The quasi-balance of extra-tropical tropospheric dynamics is a fundamental aspect of nature. If an atmospheric analysis does not reflect such balance sufficiently well, the subsequent forecast will exhibit unrealistic behavior associated with spurious fast-propagating gravity waves. Even if these eventually damp, they can create poor background fields for a subsequent analysis or interact with moist physics to create spurious precipitation. The nature of this problem will be described along with the reasons for atmospheric balance and techniques for mitigating imbalances. Attention will be focused on fundamental issues rather than on recipes for various techniques.

  14. Balance Evaluation Systems

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NeuroCom's Balance Master is a system to assess and then retrain patients with balance and mobility problems and is used in several medical centers. NeuroCom received assistance in research and funding from NASA, and incorporated technology from testing mechanisms for astronauts after shuttle flights. The EquiTest and Balance Master Systems are computerized posturography machines that measure patient responses to movement of a platform on which the subject is standing or sitting, then provide assessments of the patient's postural alignment and stability.

  15. Errors in potassium balance

    SciTech Connect

    Forbes, G.B.; Lantigua, R.; Amatruda, J.M.; Lockwood, D.H.

    1981-01-01

    Six overweight adult subjects given a low calorie diet containing adequate amounts of nitrogen but subnormal amounts of potassium (K) were observed on the Clinical Research Center for periods of 29 to 40 days. Metabolic balance of potassium was measured together with frequent assays of total body K by /sup 40/K counting. Metabolic K balance underestimated body K losses by 11 to 87% (average 43%): the intersubject variability is such as to preclude the use of a single correction value for unmeasured losses in K balance studies.

  16. Thermal-Balance Strip for Fluted LFC Panels

    NASA Technical Reports Server (NTRS)

    Bono, P.

    1985-01-01

    Waviness of less than 0.004 inch achieved using titanium strips. Process uses titanium balancing strips to keep waviness within 0.004inch limit. Balancing strips reduce thermal bonding stresses on lower fiberglass fluted sections and placed so fiberglass ends up sandwiched between porous titanium skin and titanium balance strip. Method requires less skill and less labor intensive than composite-wrapped-mandrel method.

  17. Balance Devices Train Golfers for a Consistent Swing

    NASA Technical Reports Server (NTRS)

    2015-01-01

    As part of the effort to understand the effects of spaceflight on astronauts, NASA funded research that resulted in a commercial product to treat balance disorders. West Palm Beach, Florida-based Sports Therapy Inc. worked with the inventor to modify the technology, creating the Dynamic Balance System (DBS) for sports applications. DBS is now used by Professional Golfers' Association-owned facilities and golf academies to help players achieve an effective, balanced swing.

  18. Leader as achiever.

    PubMed

    Dienemann, Jacqueline

    2002-01-01

    This article examines one outcome of leadership: productive achievement. Without achievement one is judged to not truly be a leader. Thus, the ideal leader must be a visionary, a critical thinker, an expert, a communicator, a mentor, and an achiever of organizational goals. This article explores the organizational context that supports achievement, measures of quality nursing care, fiscal accountability, leadership development, rewards and punishments, and the educational content and teaching strategies to prepare graduates to be achievers.

  19. Aggregated Residential Load Modeling Using Dynamic Bayesian Networks

    SciTech Connect

    Vlachopoulou, Maria; Chin, George; Fuller, Jason C.; Lu, Shuai

    2014-09-28

    Abstract—It is already obvious that the future power grid will have to address higher demand for power and energy, and to incorporate renewable resources of different energy generation patterns. Demand response (DR) schemes could successfully be used to manage and balance power supply and demand under operating conditions of the future power grid. To achieve that, more advanced tools for DR management of operations and planning are necessary that can estimate the available capacity from DR resources. In this research, a Dynamic Bayesian Network (DBN) is derived, trained, and tested that can model aggregated load of Heating, Ventilation, and Air Conditioning (HVAC) systems. DBNs can provide flexible and powerful tools for both operations and planing, due to their unique analytical capabilities. The DBN model accuracy and flexibility of use is demonstrated by testing the model under different operational scenarios.

  20. Mars Balance Challenge

    NASA Video Gallery

    The Challenge is to develop ideas for how NASA can turn available entry, descent, and landing balance mass on a future Mars mission into a scientific or technological payload. Proposed concepts sho...

  1. Strength and Balance Exercises

    MedlinePlus

    ... Venous Thromboembolism Aortic Aneurysm More Strength and Balance Exercises Updated:Sep 8,2016 If you have medical ... if you have been inactive and want to exercise vigorously, check with your doctor before beginning a ...

  2. Balancing Work & Family.

    ERIC Educational Resources Information Center

    Lee, Chris

    1991-01-01

    Describes the responses of some companies to increasing demands for family-work balance in terms of flexibility in working hours and leave policies, child care, and fringe benefits. Identifies some of the effects on the "bottom line." (SK)

  3. The Balanced Literacy Diet.

    ERIC Educational Resources Information Center

    Willows, Dale

    2002-01-01

    Describes professional development program in Ontario school district to improve student reading and writing skills. Program used food-pyramid concepts to help teacher learn to provide a balanced and flexible approach to literacy instruction based on student needs. (PKP)

  4. Balance Function Disorders

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Researchers at the Balance Function Laboratory and Clinic at the Minneapolis (MN) Neuroscience Institute on the Abbot Northwestern Hospital Campus are using a rotational chair (technically a "sinusoidal harmonic acceleration system") originally developed by NASA to investigate vestibular (inner ear) function in weightlessness to diagnose and treat patients with balance function disorders. Manufactured by ICS Medical Corporation, Schaumberg, IL, the chair system turns a patient and monitors his or her responses to rotational stimulation.

  5. Control of an afterburner in a diesel fuel cell power unit under variable load

    NASA Astrophysics Data System (ADS)

    Dolanc, Gregor; Pregelj, Boštjan; Petrovčič, Janko; Samsun, Remzi Can

    2017-01-01

    In this paper, the control system for a catalytic afterburner in a diesel fuel cell auxiliary power unit is presented. The catalytic afterburner is used to burn the non-utilised hydrogen and other possible combustible components of the fuel cell anode off-gas. To increase the energy efficiency of the auxiliary power unit, the thermal energy released in the catalytic afterburner is utilised to generate the steam for the fuel processor. For optimal operation of the power unit in all modes of operation including load change, stable steam generation is required and overall energy balance must be kept within design range. To achieve this, the reaction temperature of the catalytic afterburner must be stable in all modes of operation. Therefore, we propose the afterburner temperature control based on mass and thermal balances. Finally, we demonstrate the control system using the existing prototype of the diesel fuel cell auxiliary power unit.

  6. PRB rail loadings shatter record

    SciTech Connect

    Buchsbaum, L.

    2008-09-15

    Rail transport of coal in the Powder River Basin has expanded, with a record 2,197 trains loaded in a month. Arch Coal's Thunder basin mining complex has expanded by literally bridging the joint line railway. The dry fork mine has also celebrated its safety achievements. 4 photos.

  7. A world in balance.

    PubMed

    Westing, A H

    1981-01-01

    The objectives of this paper are to define the scope of global population growth within the uncompromising everyday realities of technology, economies, and politics and to demonstrate the intimate between the human population problem and the increasing problem of Nature's destruction. It is hoped that the human species will come to its sense in time to create an adequate standard of living of all of its members in peace and environmental balance. The number of people the world can support is considered in terms of 1) the provision for a standard of living adequate for everyone's health and wellbeing, 2) consideration for wildlife and nature, and 3) reliance on existing levels of technology and politics. Standards of living are suggested for the affluent and the austere. The focus on the discussion is on standards of living, global carrying capacity, the imperatives of population control and respect for nature, humans versus wildlife, and the need for a universal declaration of respect for nature. Carrying capacity is determined by total land area, cultivated land area, forest land area, cereals (grain), and wood. Use per capita of each of the 5 essentials is determined for the affluent or austere standard of living. An affluent standard means that world population would be limited to 2 billion, which is 50% of the current population. An austere standard of living means a limit of 3 billion, or 33% less than the existing population. The unfortunate reality is that today's total population of 4.5 billion is increasing at an annual rate of 1.9% and is not expected to level off until it has increased 3 times. This population growth occurs at the expense of wildlife. Of the total terrestrial animal biomass, humans constitute 4% and domestic livestock 15%, which, in 40 years, will reach a combined 40% and lead to more species extinction. One species of bird or mammal will become extinct for each increase of 220 million people, which happens every 3 years. The solution is

  8. Balancing continuous covariates based on Kernel densities.

    PubMed

    Ma, Zhenjun; Hu, Feifang

    2013-03-01

    The balance of important baseline covariates is essential for convincing treatment comparisons. Stratified permuted block design and minimization are the two most commonly used balancing strategies, both of which require the covariates to be discrete. Continuous covariates are typically discretized in order to be included in the randomization scheme. But breakdown of continuous covariates into subcategories often changes the nature of the covariates and makes distributional balance unattainable. In this article, we propose to balance continuous covariates based on Kernel density estimations, which keeps the continuity of the covariates. Simulation studies show that the proposed Kernel-Minimization can achieve distributional balance of both continuous and categorical covariates, while also keeping the group size well balanced. It is also shown that the Kernel-Minimization is less predictable than stratified permuted block design and minimization. Finally, we apply the proposed method to redesign the NINDS trial, which has been a source of controversy due to imbalance of continuous baseline covariates. Simulation shows that imbalances such as those observed in the NINDS trial can be generally avoided through the implementation of the new method.

  9. Hidden Connections between Regression Models of Strain-Gage Balance Calibration Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert

    2013-01-01

    Hidden connections between regression models of wind tunnel strain-gage balance calibration data are investigated. These connections become visible whenever balance calibration data is supplied in its design format and both the Iterative and Non-Iterative Method are used to process the data. First, it is shown how the regression coefficients of the fitted balance loads of a force balance can be approximated by using the corresponding regression coefficients of the fitted strain-gage outputs. Then, data from the manual calibration of the Ames MK40 six-component force balance is chosen to illustrate how estimates of the regression coefficients of the fitted balance loads can be obtained from the regression coefficients of the fitted strain-gage outputs. The study illustrates that load predictions obtained by applying the Iterative or the Non-Iterative Method originate from two related regression solutions of the balance calibration data as long as balance loads are given in the design format of the balance, gage outputs behave highly linear, strict statistical quality metrics are used to assess regression models of the data, and regression model term combinations of the fitted loads and gage outputs can be obtained by a simple variable exchange.

  10. Cavendish Balance Automation

    NASA Technical Reports Server (NTRS)

    Thompson, Bryan

    2000-01-01

    This is the final report for a project carried out to modify a manual commercial Cavendish Balance for automated use in cryostat. The scope of this project was to modify an off-the-shelf manually operated Cavendish Balance to allow for automated operation for periods of hours or days in cryostat. The purpose of this modification was to allow the balance to be used in the study of effects of superconducting materials on the local gravitational field strength to determine if the strength of gravitational fields can be reduced. A Cavendish Balance was chosen because it is a fairly simple piece of equipment for measuring gravity, one the least accurately known and least understood physical constants. The principle activities that occurred under this purchase order were: (1) All the components necessary to hold and automate the Cavendish Balance in a cryostat were designed. Engineering drawings were made of custom parts to be fabricated, other off-the-shelf parts were procured; (2) Software was written in LabView to control the automation process via a stepper motor controller and stepper motor, and to collect data from the balance during testing; (3)Software was written to take the data collected from the Cavendish Balance and reduce it to give a value for the gravitational constant; (4) The components of the system were assembled and fitted to a cryostat. Also the LabView hardware including the control computer, stepper motor driver, data collection boards, and necessary cabling were assembled; and (5) The system was operated for a number of periods, data collected, and reduced to give an average value for the gravitational constant.

  11. Comparing Science Achievement Constructs: Targeted and Achieved

    ERIC Educational Resources Information Center

    Ferrara, Steve; Duncan, Teresa

    2011-01-01

    This article illustrates how test specifications based solely on academic content standards, without attention to other cognitive skills and item response demands, can fall short of their targeted constructs. First, the authors inductively describe the science achievement construct represented by a statewide sixth-grade science proficiency test.…

  12. Automatic balancing of AMB systems using plural notch filter and adaptive synchronous compensation

    NASA Astrophysics Data System (ADS)

    Xu, Xiangbo; Chen, Shao; Zhang, Yanan

    2016-07-01

    To achieve automatic balancing in active magnetic bearing (AMB) system, a control method with notch filters and synchronous compensators is widely employed. However, the control precision is significantly affected by the synchronous compensation error, which is caused by parameter errors and variations of the power amplifiers. Furthermore, the computation effort may become intolerable if a 4-degree-of-freedom (dof) AMB system is studied. To solve these problems, an adaptive automatic balancing control method in the AMB system is presented in this study. Firstly, a 4-dof radial AMB system is described and analyzed. To simplify the controller design, the 4-dof dynamic equations are transferred into two plural functions related to translation and rotation, respectively. Next, to achieve automatic balancing of the AMB system, two synchronous equations are formed. Solution of them leads to a control strategy based on notch filters and feedforward controllers with an inverse function of the power amplifier. The feedforward controllers can be simplified as synchronous phases and amplitudes. Then, a plural phase-shift notch filter which can identify the synchronous components in 2-dof motions is formulated, and an adaptive compensation method that can form two closed-loop systems to tune the synchronous amplitude of the feedforward controller and the phase of the plural notch filter is proposed. Finally, the proposed control strategy is verified by both simulations and experiments on a test rig of magnetically suspended control moment gyro. The results indicate that this method can fulfill the automatic balancing of the AMB system with a light computational load.

  13. Which Achievement Gap?

    ERIC Educational Resources Information Center

    Anderson, Sharon; Medrich, Elliott; Fowler, Donna

    2007-01-01

    From the halls of Congress to the local elementary school, conversations on education reform have tossed around the term "achievement gap" as though people all know precisely what that means. As it's commonly used, "achievement gap" refers to the differences in scores on state or national achievement tests between various…

  14. Performance of on-site pilot static granular bed reactor (SGBR) for treating dairy processing wastewater and chemical oxygen demand balance modeling under different operational conditions.

    PubMed

    Oh, Jin Hwan; Park, Jaeyoung; Ellis, Timothy G

    2015-02-01

    The performance and operational stability of a pilot-scale static granular bed reactor (SGBR) for the treatment of dairy processing wastewater were investigated under a wide range of organic and hydraulic loading rates and temperature conditions. The SGBR achieved average chemical oxygen demand (COD), biological oxygen demand (BOD), and total suspended solids (TSS)-removal efficiencies higher than 90% even at high loading rates up to 7.3 kg COD/m(3)/day, with an hydraulic retention time (HRT) of 9 h, and at low temperatures of 11 °C. The average methane yield of 0.26 L CH4/g COD(removed) was possibly affected by a high fraction of particulate COD and operation at low temperatures. The COD mass balance indicated that soluble COD was responsible for most of the methane production. The reactor showed the capacity of the methanogens to maintain their activity and withstand organic and hydraulic shock loads.

  15. Evaluation of total phosphorus mass balance in the lower Boise River and selected tributaries, southwestern Idaho

    USGS Publications Warehouse

    Etheridge, Alexandra B.

    2013-01-01

    phosphorus in the lower Boise River in October 2012 and March 2013. Model results indicate that point sources represent the largest contribution of phosphorus to the Boise River year round, but that reductions in point and nonpoint source phosphorus loads may be necessary to achieve seasonal total phosphorus concentration targets at Parma (RM 3.8) from May 1 through September 30, as set by the 2004 Snake River-Hells Canyon Total Maximum Daily Load document. The mass-balance models do not account for biological or depositional instream processes, but are useful indicators of locations where appreciable phosphorus uptake or release by aquatic plants may occur.

  16. Wind Energy Management System Integration Project Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations

    SciTech Connect

    Makarov, Yuri V.; Huang, Zhenyu; Etingov, Pavel V.; Ma, Jian; Guttromson, Ross T.; Subbarao, Krishnappa; Chakrabarti, Bhujanga B.

    2010-09-01

    The power system balancing process, which includes the scheduling, real time dispatch (load following) and regulation processes, is traditionally based on deterministic models. Since the conventional generation needs time to be committed and dispatched to a desired megawatt level, the scheduling and load following processes use load and wind power production forecasts to achieve future balance between the conventional generation and energy storage on the one side, and system load, intermittent resources (such as wind and solar generation) and scheduled interchange on the other side. Although in real life the forecasting procedures imply some uncertainty around the load and wind forecasts (caused by forecast errors), only their mean values are actually used in the generation dispatch and commitment procedures. Since the actual load and intermittent generation can deviate from their forecasts, it becomes increasingly unclear (especially, with the increasing penetration of renewable resources) whether the system would be actually able to meet the conventional generation requirements within the look-ahead horizon, what the additional balancing efforts would be needed as we get closer to the real time, and what additional costs would be incurred by those needs. In order to improve the system control performance characteristics, maintain system reliability, and minimize expenses related to the system balancing functions, it becomes necessary to incorporate the predicted uncertainty ranges into the scheduling, load following, and, in some extent, into the regulation processes. It is also important to address the uncertainty problem comprehensively, by including all sources of uncertainty (load, intermittent generation, generators’ forced outages, etc.) into consideration. All aspects of uncertainty such as the imbalance size (which is the same as capacity needed to mitigate the imbalance) and generation ramping requirement must be taken into account. The latter unique

  17. A joined multi-metric calibration of river discharge and nitrate loads with different performance measures

    NASA Astrophysics Data System (ADS)

    Haas, Marcelo B.; Guse, Björn; Pfannerstill, Matthias; Fohrer, Nicola

    2016-05-01

    Hydrological models are useful tools to investigate hydrology and water quality in catchments. The calibration of these models is a crucial step to adapt the model to the catchment conditions, allowing effective simulations of environmental processes. In the model calibration, different performance measures need to be considered to represent different hydrology and water quality conditions in combination. This study presents a joined multi-metric calibration of discharge and nitrate loads simulated with the ecohydrological model SWAT. For this purpose, a calibration approach based on flow duration curves (FDC) is advanced by also considering nitrate duration curves (NDC). Five segments of FDCs and of NDCs are evaluated separately to consider the different phases of hydrograph and nitrograph. To consider both magnitude and dynamics in river discharge and nitrate loads, the Kling-Gupta Efficiency (KGE) is used additionally as a statistical performance metric to achieve a joined multi-variable calibration. The results show that a separate assessment of five different magnitudes improves the calibrated nitrate loads. Subsequently, adequate model runs with good performance for different hydrological conditions both for discharge and nitrate are detected in a joined approach based on FDC, NDC, and KGE. In that manner, plausible results were obtained for discharge and nitrate loads in the same model run. Using a multi-metric performance approach, the simultaneous multi-variable calibration led to a balanced model result for all magnitudes of discharge and nitrate loads.

  18. Balancing low cost with reliable operation in the rotordynamic design of the ALS Liquid Hydrogen Fuel Turbopump

    NASA Technical Reports Server (NTRS)

    Greenhill, L. M.

    1990-01-01

    The Air Force/NASA Advanced Launch System (ALS) Liquid Hydrogen Fuel Turbopump (FTP) has primary design goals of low cost and high reliability, with performance and weight having less importance. This approach is atypical compared with other rocket engine turbopump design efforts, such as on the Space Shuttle Main Engine (SSME), which emphasized high performance and low weight. Similar to the SSME turbopumps, the ALS FTP operates supercritically, which implies that stability and bearing loads strongly influence the design. In addition, the use of low cost/high reliability features in the ALS FTP such as hydrostatic bearings, relaxed seal clearances, and unshrouded turbine blades also have a negative influence on rotordynamics. This paper discusses the analysis conducted to achieve a balance between low cost and acceptable rotordynamic behavior, to ensure that the ALS FTP will operate reliably without subsynchronous instabilities or excessive bearing loads.

  19. Balanced ultrafiltration: inflammatory mediator removal capacity.

    PubMed

    Guan, Yulong; Wan, Caihong; Wang, Shigang; Sun, Peng; Long, Cun

    2012-10-01

    Ultrafiltration with a hemoconcentrator may remove excess fluid load and alleviate tissue edema and has been universally adopted in extracorporeal circulation protocols during pediatric cardiac surgery. Balanced ultrafiltration is advocated to remove inflammatory mediators generated during surgery. However, whether balanced ultrafiltration can remove all or a portion of the inflammatory mediator load remains unclear. The inflammatory mediator removal capacity of zero-balanced ultrafiltration was measured during pediatric extracorporeal circulation in vitro. Extracorporeal circulation was composed of cardiotomy reservoir, D902 Lilliput 2 membrane oxygenator, and Capiox AF02 pediatric arterial line filter. The Hemoconcentrator BC 20 plus was placed between arterial purge line and oxygenator venous reservoir. Fresh donor human whole blood was added into the circuit and mixed with Ringer's solution to obtain a final hematocrit of 24-28%. After 2 h of extracorporeal circulation, zero-balanced ultrafiltration was initiated and arterial line pressure was maintained at approximately 100 mmHg with Hoffman clamp. The rate of ultrafiltration (12 mL/min) was controlled by ultrafiltrate outlet pressure. Identical volume of plasmaslyte A was dripped into the circuit to maintain stable hematocrit during the 45 min of the experiment. Plasma and ultrafiltrate samples were drawn every 5 min, and concentrations of inflammatory mediators including interleukin-1β (IL-1β), IL-6, IL-10, neutrophil elastase (NE), and tumor necrosis factor-α (TNF-α) were measured. All assayed inflammatory mediators were detected in the ultrafiltrate, demonstrating that the ultrafiltrator may remove inflammatory mediators. However, dynamic observations suggested that the concentration of NE was highest among the five inflammatory mediators in both plasma and ultrafiltrate (P < 0.001). IL-1β had the lowest concentration in plasma, whereas the concentration of TNF-α was the lowest in ultrafiltrate (P

  20. Balancing Teacher Quality and Quantity

    NASA Astrophysics Data System (ADS)

    Bond, Helen

    The world is facing a shortage of trained teachers. According to the 2010 Global Monitoring Report approximately 10.3 million teachers will be needed globally to staff classrooms from Bangkok to Canada. The situation is worse in Sub-Saharan Africa. Estimates suggest that approximately 1.2 million new teachers will be needed in Sub-Saharan Africa alone to achieve universal primary education goals by 2015. Increases in primary school enrollments, drought, and HIV-AIDS have exacerbated the need for well trained teachers. Despite the need, the focus is on balancing quality with quantity. An effective teacher is deemed a critical element, although not the only one, in a student's success in the classroom. This paper focuses on the dilemma of meeting universal primary education goals in Sub-Saharan Africa, while maintaining teacher quality in fragile contexts.

  1. Sport-specific balance.

    PubMed

    Zemková, Erika

    2014-05-01

    This review includes the latest findings based on experimental studies addressing sport-specific balance, an area of research that has grown dramatically in recent years. The main objectives of this work were to investigate the postural sway response to different forms of exercise under laboratory and sport-specific conditions, to examine how this effect can vary with expertise, and to provide examples of the association of impaired balance with sport performance and/or increasing risk of injury. In doing so, sports where body balance is one of the limiting factors of performance were analyzed. While there are no significant differences in postural stability between athletes of different specializations and physically active individuals during standing in a standard upright position (e.g., bipedal stance), they have a better ability to maintain balance in specific conditions (e.g., while standing on a narrow area of support). Differences in magnitude of balance impairment after specific exercises (rebound jumps, repeated rotations, etc.) and mainly in speed of its readjustment to baseline are also observed. Besides some evidence on an association of greater postural sway with the increasing risk of injuries, there are many myths related to the negative influence of impaired balance on sport performance. Though this may be true for shooting or archery, findings have shown that in many other sports, highly skilled athletes are able to perform successfully in spite of increased postural sway. These findings may contribute to better understanding of the postural control system under various performance requirements. It may provide useful knowledge for designing training programs for specific sports.

  2. Calibration Variable Selection and Natural Zero Determination for Semispan and Canard Balances

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert M.

    2013-01-01

    Independent calibration variables for the characterization of semispan and canard wind tunnel balances are discussed. It is shown that the variable selection for a semispan balance is determined by the location of the resultant normal and axial forces that act on the balance. These two forces are the first and second calibration variable. The pitching moment becomes the third calibration variable after the normal and axial forces are shifted to the pitch axis of the balance. Two geometric distances, i.e., the rolling and yawing moment arms, are the fourth and fifth calibration variable. They are traditionally substituted by corresponding moments to simplify the use of calibration data during a wind tunnel test. A canard balance is related to a semispan balance. It also only measures loads on one half of a lifting surface. However, the axial force and yawing moment are of no interest to users of a canard balance. Therefore, its calibration variable set is reduced to the normal force, pitching moment, and rolling moment. The combined load diagrams of the rolling and yawing moment for a semispan balance are discussed. They may be used to illustrate connections between the wind tunnel model geometry, the test section size, and the calibration load schedule. Then, methods are reviewed that may be used to obtain the natural zeros of a semispan or canard balance. In addition, characteristics of three semispan balance calibration rigs are discussed. Finally, basic requirements for a full characterization of a semispan balance are reviewed.

  3. NASA LaRC Strain Gage Balance Design Concepts

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.

    1999-01-01

    The NASA Langley Research Center (LaRC) has been designing strain-gage balances for more than fifty years. These balances have been utilized in Langley's wind tunnels, which span over a wide variety of aerodynamic test regimes, as well as other ground based test facilities and in space flight applications. As a result, the designs encompass a large array of sizes, loads, and environmental effects. Currently Langley has more than 300 balances available for its researchers. This paper will focus on the design concepts for internal sting mounted strain-gage balances. However, these techniques can be applied to all force measurement design applications. Strain-gage balance concepts that have been developed over the years including material selection, sting, model interfaces, measuring, sections, fabrication, strain-gaging and calibration will be discussed.

  4. Constant current load matches impedances of electronic components

    NASA Technical Reports Server (NTRS)

    Alexander, R. M.

    1970-01-01

    Constant current load with negative resistance characteristics actively compensates for impedance variations in circuit components. Through a current-voltage balancing operation the internal impedance of the diodes is maintained at a constant value. This constant current load circuit can be used in simple telemetry systems.

  5. Single Vector Calibration System for Multi-Axis Load Cells and Method for Calibrating a Multi-Axis Load Cell

    NASA Technical Reports Server (NTRS)

    Parker, Peter A. (Inventor)

    2003-01-01

    A single vector calibration system is provided which facilitates the calibration of multi-axis load cells, including wind tunnel force balances. The single vector system provides the capability to calibrate a multi-axis load cell using a single directional load, for example loading solely in the gravitational direction. The system manipulates the load cell in three-dimensional space, while keeping the uni-directional calibration load aligned. The use of a single vector calibration load reduces the set-up time for the multi-axis load combinations needed to generate a complete calibration mathematical model. The system also reduces load application inaccuracies caused by the conventional requirement to generate multiple force vectors. The simplicity of the system reduces calibration time and cost, while simultaneously increasing calibration accuracy.

  6. Rotary and Magnus balances

    NASA Technical Reports Server (NTRS)

    Malcolm, G. N.

    1981-01-01

    Two wind tunnel techniques for determining part of the aerodynamic information required to describe the dynamic bahavior of various types of vehicles in flight are described. Force and moment measurements are determined with a rotary-balance apparatus in a coning motion and with a Magnus balance in a high-speed spinning motion. Coning motion is pertinent to both aircraft and missiles, and spinning is important for spin stabilized missiles. Basic principles of both techniques are described, and specific examples of each type of apparatus are presented. Typical experimental results are also discussed.

  7. Development of the NTF-117S Semi-Span Balance

    NASA Technical Reports Server (NTRS)

    Lynn, Keith C.

    2010-01-01

    A new high-capacity semi-span force and moment balance has recently been developed for use at the National Transonic Facility at the NASA Langley Research Center. This new semi-span balance provides the NTF a new measurement capability that will support testing of semi-span test models at transonic high-lift testing regimes. Future testing utilizing this new balance capability will include active circulation control and propulsion simulation testing of semi-span transonic wing models. The NTF has recently implemented a new highpressure air delivery station that will provide both high and low mass flow pressure lines that are routed out to the semi-span models via a set high/low pressure bellows that are indirectly linked to the metric end of the NTF-117S balance. A new check-load stand is currently being developed to provide the NTF with an in-house capability that will allow for performing check-loads on the NTF-117S balance in order to determine the pressure tare affects on the overall performance of the balance. An experimental design is being developed that will allow for experimentally assessing the static pressure tare affects on the balance performance.

  8. Wind Energy Management System EMS Integration Project: Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations

    SciTech Connect

    Makarov, Yuri V.; Huang, Zhenyu; Etingov, Pavel V.; Ma, Jian; Guttromson, Ross T.; Subbarao, Krishnappa; Chakrabarti, Bhujanga B.

    2010-01-01

    The power system balancing process, which includes the scheduling, real time dispatch (load following) and regulation processes, is traditionally based on deterministic models. Since the conventional generation needs time to be committed and dispatched to a desired megawatt level, the scheduling and load following processes use load and wind and solar power production forecasts to achieve future balance between the conventional generation and energy storage on the one side, and system load, intermittent resources (such as wind and solar generation), and scheduled interchange on the other side. Although in real life the forecasting procedures imply some uncertainty around the load and wind/solar forecasts (caused by forecast errors), only their mean values are actually used in the generation dispatch and commitment procedures. Since the actual load and intermittent generation can deviate from their forecasts, it becomes increasingly unclear (especially, with the increasing penetration of renewable resources) whether the system would be actually able to meet the conventional generation requirements within the look-ahead horizon, what the additional balancing efforts would be needed as we get closer to the real time, and what additional costs would be incurred by those needs. To improve the system control performance characteristics, maintain system reliability, and minimize expenses related to the system balancing functions, it becomes necessary to incorporate the predicted uncertainty ranges into the scheduling, load following, and, in some extent, into the regulation processes. It is also important to address the uncertainty problem comprehensively by including all sources of uncertainty (load, intermittent generation, generators’ forced outages, etc.) into consideration. All aspects of uncertainty such as the imbalance size (which is the same as capacity needed to mitigate the imbalance) and generation ramping requirement must be taken into account. The latter

  9. Analyzing Hydrological Sustainability Through Water Balance

    NASA Astrophysics Data System (ADS)

    Menció, Anna; Folch, Albert; Mas-Pla, Josep

    2010-05-01

    The objective of the Water Framework Directive (2000/60/EC) is to assist in the development of management plans that will lead to the sustainable use of water resources in all EU member states. However, defining the degree of sustainability aimed at is not a straightforward task. It requires detailed knowledge of the hydrogeological characteristics of the basin in question, its environmental needs, the amount of human water demand, and the opportunity to construct a proper water balance that describes the behavior of the hydrological system and estimates available water resources. An analysis of the water balance in the Selva basin (Girona, NE Spain) points to the importance of regional groundwater fluxes in satisfying current exploitation rates, and shows that regional scale approaches are often necessary to evaluate water availability. In addition, we discuss the pressures on water resources, and analyze potential actions, based on the water balance results, directed towards achieving sustainable water management in the basin.

  10. Termination of Nutrient Import and Development of Vein Loading Capacity in Albino Tobacco Leaves

    PubMed Central

    Turgeon, Robert

    1984-01-01

    The sink-source conversion in developing leaves of tobacco (Nicotiana tabacum L.) was studied to determine whether import termination is caused by the onset of export or is related to achievement of positive carbon balance. Albino shoots were grown in vitro and grafted to detopped stems of green tobacco plants. Termination of import was studied by providing mature leaves of the stock plant with 14CO2 and detecting the presence of labeled nutrient in developing albino leaves by whole-leaf autoradiography. In albino leaves, import terminated progressively in the basipetal direction at the same stage of development as in leaves of green shoots. Starch was not present in the plastids of mesophyll cells of mature albino leaves but starch was synthesized when discs were cut from these leaves and incubated on 3 millimolar sucrose. Import ceased progressively in developing green leaves even when photosynthesis was prevented by darkening. It was concluded that cessation of import does not require achievement of positive carbon balance and is not the direct result of export initiation. To determine whether vein loading capacity develops in albino leaves, discs were cut from mature leaves and floated on [14C]sucrose solution. Uptake of label into the veins was detected by autoradiography and this uptake was sensitive to the phloem loading inhibitor p-chloromercuribenzenesulfonic acid. However, the amount of label taken up by veins in albino leaves was less than that taken up by veins of mature green leaves. Images Fig. 2 Fig. 4 Fig. 5 PMID:16663820

  11. Offshore tanker loading system

    SciTech Connect

    Baan, J. de; Heijst, W.J. van.

    1994-01-04

    The present invention relates to an improved flexible loading system which provides fluid communication between a subsea pipeline and a surface vessel including a hose extending from the subsea pipeline to a first buoyancy tank, a second hose extending from the first buoyancy tank to a central buoyancy tank, a second buoyancy tank, means connecting said second buoyancy tank to the sea floor and to the central buoyancy tank whereby the forces exerted on said central buoyant tank by said second hose and said connecting means are balanced to cause said central buoyancy tank to maintain a preselected position, a riser section extending upwardly from said central buoyancy tank and means on the upper termination for engagement by a vessel on the surface to raise said upper termination onto the vessel to complete the communication for moving fluids between the subsea pipeline and the vessel. In one form the means for connecting between the sea floor to the second buoyancy tank includes an anchor on the sea floor and lines extending from the anchor to the second buoyancy tank and from the second buoyancy tank to the central buoyancy tank. In another form of the invention the means for connecting is a third hose extending from a second subsea pipeline to the second buoyancy tank and a fourth hose extending from the second buoyancy tank to the central buoyancy tank. The central buoyancy tank is preferred to be maintained at a level below the water surface which allows full movement of the vessel while connected to the riser section. A swivel may be positioned in the riser section and a pressure relief system may be included in the loading system to protect it from sudden excess pressures. 17 figs.

  12. Distributed Load Shedding over Directed Communication Networks with Time Delays

    SciTech Connect

    Yang, Tao; Wu, Di

    2016-07-25

    When generation is insufficient to support all loads under emergencies, effective and efficient load shedding needs to be deployed in order to maintain the supply-demand balance. This paper presents a distributed load shedding algorithm, which makes efficient decision based on the discovered global information. In the global information discovery process, each load only communicates with its neighboring load via directed communication links possibly with arbitrarily large but bounded time varying communication delays. We propose a novel distributed information discovery algorithm based on ratio consensus. Simulation results are used to validate the proposed method.

  13. Single-Vector Calibration of Wind-Tunnel Force Balances

    NASA Technical Reports Server (NTRS)

    Parker, P. A.; DeLoach, R.

    2003-01-01

    An improved method of calibrating a wind-tunnel force balance involves the use of a unique load application system integrated with formal experimental design methodology. The Single-Vector Force Balance Calibration System (SVS) overcomes the productivity and accuracy limitations of prior calibration methods. A force balance is a complex structural spring element instrumented with strain gauges for measuring three orthogonal components of aerodynamic force (normal, axial, and side force) and three orthogonal components of aerodynamic torque (rolling, pitching, and yawing moments). Force balances remain as the state-of-the-art instrument that provide these measurements on a scale model of an aircraft during wind tunnel testing. Ideally, each electrical channel of the balance would respond only to its respective component of load, and it would have no response to other components of load. This is not entirely possible even though balance designs are optimized to minimize these undesirable interaction effects. Ultimately, a calibration experiment is performed to obtain the necessary data to generate a mathematical model and determine the force measurement accuracy. In order to set the independent variables of applied load for the calibration 24 NASA Tech Briefs, October 2003 experiment, a high-precision mechanical system is required. Manual deadweight systems have been in use at Langley Research Center (LaRC) since the 1940s. These simple methodologies produce high confidence results, but the process is mechanically complex and labor-intensive, requiring three to four weeks to complete. Over the past decade, automated balance calibration systems have been developed. In general, these systems were designed to automate the tedious manual calibration process resulting in an even more complex system which deteriorates load application quality. The current calibration approach relies on a one-factor-at-a-time (OFAT) methodology, where each independent variable is

  14. A Balancing Act

    ERIC Educational Resources Information Center

    Lewis, Tamika; Mobley, Mary; Huttenlock, Daniel

    2013-01-01

    It's the season for the job hunt, whether one is looking for their first job or taking the next step along their career path. This article presents first-person accounts to see how teachers balance the rewards and challenges of working in different types of schools. Tamica Lewis, a third-grade teacher, states that faculty at her school is…

  15. Balancing Family and Work.

    ERIC Educational Resources Information Center

    Yahnke, Sally; And Others

    The purpose of this monograph is to present a series of activities designed to teach strategies needed for effectively managing the multiple responsibilities of family and work. The guide contains 11 lesson plans dealing with balancing family and work that can be used in any home economics class, from middle school through college. The lesson…

  16. Balancing Your Evaluation Act.

    ERIC Educational Resources Information Center

    Willyerd, Karie A.

    1997-01-01

    Looks at different performance-measurement tools than can ensure that a training or performance solution is strategically aligned, objectively evaluated, and quantitatively measured for results. Suggests aiming for a balance among the financial, customer, and internal perspectives and the innovation and learning that can result. (Author/JOW)

  17. Balance functions reexamined

    SciTech Connect

    Bialas, A.

    2011-02-15

    The idea of glue clusters, i.e., short-range correlations in the quark-gluon plasma close to freeze-out, is used to estimate the width of balance functions in momentum space. A good agreement is found with the recent measurements of the STAR Collaboration for central Au-Au collisions.

  18. Regulation of Energy Balance.

    ERIC Educational Resources Information Center

    Bray, George A.

    1985-01-01

    Explains relationships between energy intake and expenditure focusing on the cellular, chemical and neural mechanisms involved in regulation of energy balance. Information is referenced specifically to conditions of obesity. (Physicians may earn continuing education credit by completing an appended test). (ML)

  19. Finding a Balance.

    ERIC Educational Resources Information Center

    Gordon, Milton A.; Gordon, Margaret F.

    1996-01-01

    New college presidents are inundated with requests for their time, and their private life is often sacrificed. Each administrator must decide what is the appropriate balance among various aspects of his/her position. Physical separation of public and private lives is essential, and the role of the spouse, who may have other professional…

  20. Lives in the Balance.

    ERIC Educational Resources Information Center

    Our Children, 1997

    1997-01-01

    Changes in the workplace that would provide flexibility for working parents are slowly developing and receiving government, business, and societal attention. A sidebar, "Mother, Professional, Volunteer: One Woman's Balancing Act," presents an account of how one woman rearranged her professional life to enable her to do full-time…

  1. Maintaining an Environmental Balance

    ERIC Educational Resources Information Center

    Environmental Science and Technology, 1976

    1976-01-01

    A recent conference of the National Environmental Development Association focused on the concepts of environment, energy and economy and underscored the necessity for balancing the critical needs embodied in these issues. Topics discussed included: nuclear energy and wastes, water pollution control, federal regulations, environmental technology…

  2. A novel dual-frequency loading system for studying mechanobiology of load-bearing tissue.

    PubMed

    Zhang, Chunqiu; Qiu, Lulu; Gao, Lilan; Guan, Yinjie; Xu, Qiang; Zhang, Xizheng; Chen, Qian

    2016-12-01

    In mechanobiological research, an appropriate loading system is an essential tool to mimic mechanical signals in a native environment. To achieve this goal, we have developed a novel loading system capable of applying dual-frequency loading including both a low-frequency high-amplitude loading and a high-frequency low-amplitude loading, according to the mechanical conditions experienced by bone and articular cartilage tissues. The low-frequency high-amplitude loading embodies the main force from muscular contractions and/or reaction forces while the high-frequency low-amplitude loading represents an assistant force from small muscles, ligaments and/or other tissue in order to maintain body posture during human activities. Therefore, such dual frequency loading system may reflect the natural characteristics of complex mechanical load on bone or articular cartilage than the single frequency loading often applied during current mechanobiological experiments. The dual-frequency loading system is validated by experimental tests using precision miniature plane-mirror interferometers. The dual-frequency loading results in significantly more solute transport in articular cartilage than that of the low-frequency high-amplitude loading regiment alone, as determined by quantitative fluorescence microscopy of tracer distribution in articular cartilage. Thus, the loading system can provide a new method to mimic mechanical environment in bone and cartilage, thereby revealing the in vivo mechanisms of mechanosensation, mechanotransduction and mass-transport, and improving mechanical conditioning of cartilage and/or bone constructs for tissue engineering.

  3. Drug Loading of Mesoporous Silicon

    NASA Astrophysics Data System (ADS)

    Moffitt, Anne; Coffer, Jeff; Wang, Mengjia

    2011-03-01

    The nanostructuring of crystalline solids with low aqueous solubilities by their incorporation into mesoporous host materials is one route to improve the bioavailability of such solids. Earlier studies suggest that mesoporous Si (PSi), with pore widths in the range of 5-50 nm, is a candidate for such an approach. In this presentation, we describe efforts to load curcumin into free-standing microparticles of PSi. Curcumin is a compound extracted from turmeric root, which is an ingredient of curry. Curucmin has shown activity against selected cancer cell lines, bacteria, and other medical conditions. However, curcumin has a very low bioavailability due to its extremely low water solubility (0.6 μ g/mL). Incorporation of curcumin was achieved by straightforward loading of the molten solid at 185circ; C. Loading experiments were performed using PSi particles of two different size ranges, 45-75 μ m and 150-250 μ m. Longer loading times and ratio of curcumin to PSi leads to a higher percentage of loaded curcumin in both PSi particle sizes (as determined by weight difference). The extent of curcumin crystallinity was assessed by x-ray diffraction (XRD). The solubility and release kinetics of loaded curcumin from the PSi was determined by extraction into water at 37circ; C, with analysis using UV-VIS spectrometry. NSF-REU and TCU.

  4. Maximizing TDRS Command Load Lifetime

    NASA Technical Reports Server (NTRS)

    Brown, Aaron J.

    2002-01-01

    was therefore the key to achieving this goal. This goal was eventually realized through development of an Excel spreadsheet tool called EMMIE (Excel Mean Motion Interactive Estimation). EMMIE utilizes ground ephemeris nodal data to perform a least-squares fit to inferred mean anomaly as a function of time, thus generating an initial estimate for mean motion. This mean motion in turn drives a plot of estimated downtrack position difference versus time. The user can then manually iterate the mean motion, and determine an optimal value that will maximize command load lifetime. Once this optimal value is determined, the mean motion initially calculated by the command builder tool is overwritten with the new optimal value, and the command load is built for uplink to ISS. EMMIE also provides the capability for command load lifetime to be tracked through multiple TORS ephemeris updates. Using EMMIE, TORS command load lifetimes of approximately 30 days have been achieved.

  5. 'No delays achiever'.

    PubMed

    2007-05-01

    The latest version of the NHS Institute for Innovation and Improvement's 'no delays achiever', a web based tool created to help NHS organisations achieve the 18-week target for GP referrals to first treatment, is available at www.nodelaysachiever.nhs.uk.

  6. Vicarious Achievement Orientation.

    ERIC Educational Resources Information Center

    Leavitt, Harold J.; And Others

    This study tests hypotheses about achievement orientation, particularly vicarious achievement. Undergraduate students (N=437) completed multiple-choice questionnaires, indicating likely responses of one person to the success of another. The sex of succeeder and observer, closeness of relationship, and setting (medical school or graduate school of…

  7. Heritability of Creative Achievement

    ERIC Educational Resources Information Center

    Piffer, Davide; Hur, Yoon-Mi

    2014-01-01

    Although creative achievement is a subject of much attention to lay people, the origin of individual differences in creative accomplishments remain poorly understood. This study examined genetic and environmental influences on creative achievement in an adult sample of 338 twins (mean age = 26.3 years; SD = 6.6 years). Twins completed the Creative…

  8. Confronting the Achievement Gap

    ERIC Educational Resources Information Center

    Gardner, David

    2007-01-01

    This article talks about the large achievement gap between children of color and their white peers. The reasons for the achievement gap are varied. First, many urban minorities come from a background of poverty. One of the detrimental effects of growing up in poverty is receiving inadequate nourishment at a time when bodies and brains are rapidly…

  9. Achievement-Based Resourcing.

    ERIC Educational Resources Information Center

    Fletcher, Mike; And Others

    1992-01-01

    This collection of seven articles examines achievement-based resourcing (ABR), the concept that the funding of educational institutions should be linked to their success in promoting student achievement, with a focus on the application of ABR to postsecondary education in the United Kingdom. The articles include: (1) "Introduction" (Mick…

  10. States Address Achievement Gaps.

    ERIC Educational Resources Information Center

    Christie, Kathy

    2002-01-01

    Summarizes 2 state initiatives to address the achievement gap: North Carolina's report by the Advisory Commission on Raising Achievement and Closing Gaps, containing an 11-point strategy, and Kentucky's legislation putting in place 10 specific processes. The North Carolina report is available at www.dpi.state.nc.us.closingthegap; Kentucky's…

  11. The Copper Balance of Cities

    PubMed Central

    Kral, Ulrich; Lin, Chih-Yi; Kellner, Katharina; Ma, Hwong-wen; Brunner, Paul H

    2014-01-01

    Material management faces a dual challenge: on the one hand satisfying large and increasing demands for goods and on the other hand accommodating wastes and emissions in sinks. Hence, the characterization of material flows and stocks is relevant for both improving resource efficiency and environmental protection. This article focuses on the urban scale, a dimension rarely investigated in past metal flow studies. We compare the copper (Cu) metabolism of two cities in different economic states, namely, Vienna (Europe) and Taipei (Asia). Substance flow analysis is used to calculate urban Cu balances in a comprehensive and transparent form. The main difference between Cu in the two cities appears to be the stock: Vienna seems close to saturation with 180 kilograms per capita (kg/cap) and a growth rate of 2% per year. In contrast, the Taipei stock of 30 kg/cap grows rapidly by 26% per year. Even though most Cu is recycled in both cities, bottom ash from municipal solid waste incineration represents an unused Cu potential accounting for 1% to 5% of annual demand. Nonpoint emissions are predominant; up to 50% of the loadings into the sewer system are from nonpoint sources. The results of this research are instrumental for the design of the Cu metabolism in each city. The outcomes serve as a base for identification and recovery of recyclables as well as for directing nonrecyclables to appropriate sinks, avoiding sensitive environmental pathways. The methodology applied is well suited for city benchmarking if sufficient data are available. PMID:25866460

  12. OVERVIEW AND STATUS OF LAKE MICHIGAN MASS BALANCE MODELLING PROJECT

    EPA Science Inventory

    With most of the data available from the Lake Michigan Mass Balance Project field program, the modeling efforts have begun in earnest. The tributary and atmospheric load estimates are or will be completed soon, so realistic simulations for calibration are beginning. A Quality Ass...

  13. A Force Transducer from a Junk Electronic Balance

    ERIC Educational Resources Information Center

    Aguilar, Horacio Munguia; Aguilar, Francisco Armenta

    2009-01-01

    It is shown how the load cell from a junk electronic balance can be used as a force transducer for physics experiments. Recovering this device is not only an inexpensive way of getting a valuable laboratory tool but also very useful didactic work on electronic instrumentation. Some experiments on mechanics with this transducer are possible after a…

  14. Achievability for telerobotic systems

    NASA Astrophysics Data System (ADS)

    Kress, Reid L.; Draper, John V.; Hamel, William R.

    2001-02-01

    Methods are needed to improve the capabilities of autonomous robots to perform tasks that are difficult for contemporary robots, and to identify those tasks that robots cannot perform. Additionally, in the realm of remote handling, methods are needed to assess which tasks and/or subtasks are candidates for automation. We are developing a new approach to understanding the capability of autonomous robotic systems. This approach uses formalized methods for determining the achievability of tasks for robots, that is, the likelihood that an autonomous robot or telerobot can successfully complete a particular task. Any autonomous system may be represented in achievability space by the volume describing that system's capabilities within the 3-axis space delineated by perception, cognition, and action. This volume may be thought of as a probability density with achievability decreasing as the distance from the centroid of the volume increases. Similarly, any task may be represented within achievability space. However, as tasks have more finite requirements for perception, cognition, and action, each may be represented as a point (or, more accurately, as a small sphere) within achievability space. Analysis of achievability can serve to identify, a priori, the survivability of robotic systems and the likelihood of mission success; it can be used to plan a mission or portions of a mission; it can be used to modify a mission plan to accommodate unpredicted occurrences; it can also serve to identify needs for modifications to robotic systems or tasks to improve achievability. .

  15. Experimental performance evaluation of human balance control models.

    PubMed

    Huryn, Thomas P; Blouin, Jean-Sébastien; Croft, Elizabeth A; Koehle, Michael S; Van der Loos, H F Machiel

    2014-11-01

    Two factors commonly differentiate proposed balance control models for quiet human standing: 1) intermittent muscle activation and 2) prediction that overcomes sensorimotor time delays. In this experiment we assessed the viability and performance of intermittent activation and prediction in a balance control loop that included the neuromuscular dynamics of human calf muscles. Muscles were driven by functional electrical stimulation (FES). The performance of the different controllers was compared based on sway patterns and mechanical effort required to balance a human body load on a robotic balance simulator. All evaluated controllers balanced subjects with and without a neural block applied to their common peroneal and tibial nerves, showing that the models can produce stable balance in the absence of natural activation. Intermittent activation required less stimulation energy than continuous control but predisposed the system to increased sway. Relative to intermittent control, continuous control reproduced the sway size of natural standing better. Prediction was not necessary for stable balance control but did improve stability when control was intermittent, suggesting a possible benefit of a predictor for intermittent activation. Further application of intermittent activation and predictive control models may drive prolonged, stable FES-controlled standing that improves quality of life for people with balance impairments.

  16. Lunar Balance and Locomotion

    NASA Technical Reports Server (NTRS)

    Paloski, William H.

    2008-01-01

    Balance control and locomotor patterns were altered in Apollo crewmembers on the lunar surface, owing, presumably, to a combination of sensory-motor adaptation during transit and lunar surface operations, decreased environmental affordances associated with the reduced gravity, and restricted joint mobility as well as altered center-of-gravity caused by the EVA pressure suits. Dr. Paloski will discuss these factors, as well as the potential human and mission impacts of falls and malcoordination during planned lunar sortie and outpost missions. Learning objectives: What are the potential impacts of postural instabilities on the lunar surface? CME question: What factors affect balance control and gait stability on the moon? Answer: Sensory-motor adaptation to the lunar environment, reduced mechanical and visual affordances, and altered biomechanics caused by the EVA suit.

  17. Wind Tunnel Force Balance Calibration Study - Interim Results

    NASA Technical Reports Server (NTRS)

    Rhew, Ray D.

    2012-01-01

    Wind tunnel force balance calibration is preformed utilizing a variety of different methods and does not have a direct traceable standard such as standards used for most calibration practices (weights, and voltmeters). These different calibration methods and practices include, but are not limited to, the loading schedule, the load application hardware, manual and automatic systems, re-leveling and non-re-leveling. A study of the balance calibration techniques used by NASA was undertaken to develop metrics for reviewing and comparing results using sample calibrations. The study also includes balances of different designs, single and multi-piece. The calibration systems include, the manual, and the automatic that are provided by NASA and its vendors. The results to date will be presented along with the techniques for comparing the results. In addition, future planned calibrations and investigations based on the results will be provided.

  18. Seismic offset balancing

    SciTech Connect

    Ross, C.P.; Beale, P.L.

    1994-01-01

    The ability to successfully predict lithology and fluid content from reflection seismic records using AVO techniques is contingent upon accurate pre-analysis conditioning of the seismic data. However, all too often, residual amplitude effects remain after the many offset-dependent processing steps are completed. Residual amplitude effects often represent a significant error when compared to the amplitude variation with offset (AVO) response that the authors are attempting to quantify. They propose a model-based, offset-dependent amplitude balancing method that attempts to correct for these residuals and other errors due to sub-optimal processing. Seismic offset balancing attempts to quantify the relationship between the offset response of back-ground seismic reflections and corresponding theoretical predictions for average lithologic interfaces thought to cause these background reflections. It is assumed that any deviation from the theoretical response is a result of residual processing phenomenon and/or suboptimal processing, and a simple offset-dependent scaling function is designed to correct for these differences. This function can then be applied to seismic data over both prospective and nonprospective zones within an area where the theoretical values are appropriate and the seismic characteristics are consistent. A conservative application of the above procedure results in an AVO response over both gas sands and wet sands that is much closer to theoretically expected values. A case history from the Gulf of Mexico Flexure Trend is presented as an example to demonstrate the offset balancing technique.

  19. Gait and balance disorders.

    PubMed

    Masdeu, Joseph C

    2016-01-01

    This chapter focuses on one of the most common types of neurologic disorders: altered walking. Walking impairment often reflects disease of the neurologic structures mediating gait, balance or, most often, both. These structures are distributed along the neuraxis. For this reason, this chapter is introduced by a brief description of the neurobiologic underpinning of walking, stressing information that is critical for imaging, namely, the anatomic representation of gait and balance mechanisms. This background is essential not only in order to direct the relevant imaging tools to the regions more likely to be affected but also to interpret correctly imaging findings that may not be related to the walking deficit object of clinical study. The chapter closes with a discussion on how to image some of the most frequent etiologies causing gait or balance impairment. However, it focuses on syndromes not already discussed in other chapters of this volume, such as Parkinson's disease and other movement disorders, already discussed in Chapter 48, or cerebellar ataxia, in Chapter 23, in the previous volume. As regards vascular disease, the spastic hemiplegia most characteristic of brain disease needs little discussion, while the less well-understood effects of microvascular disease are extensively reviewed here, together with the imaging approach.

  20. Simple Cell Balance Circuit

    NASA Technical Reports Server (NTRS)

    Johnson, Steven D.; Byers, Jerry W.; Martin, James A.

    2012-01-01

    A method has been developed for continuous cell voltage balancing for rechargeable batteries (e.g. lithium ion batteries). A resistor divider chain is provided that generates a set of voltages representing the ideal cell voltage (the voltage of each cell should be as if the cells were perfectly balanced). An operational amplifier circuit with an added current buffer stage generates the ideal voltage with a very high degree of accuracy, using the concept of negative feedback. The ideal voltages are each connected to the corresponding cell through a current- limiting resistance. Over time, having the cell connected to the ideal voltage provides a balancing current that moves the cell voltage very close to that ideal level. In effect, it adjusts the current of each cell during charging, discharging, and standby periods to force the cell voltages to be equal to the ideal voltages generated by the resistor divider. The device also includes solid-state switches that disconnect the circuit from the battery so that it will not discharge the battery during storage. This solution requires relatively few parts and is, therefore, of lower cost and of increased reliability due to the fewer failure modes. Additionally, this design uses very little power. A preliminary model predicts a power usage of 0.18 W for an 8-cell battery. This approach is applicable to a wide range of battery capacities and voltages.

  1. FRICTION-FREE BALANCE

    DOEpatents

    Carson, N.J. Jr.; Ostrander, H.W.; Munter, C.N.

    1964-03-01

    A weighing device having a load-supporting vertical shaft buoyed up by mutually repellant magnets is described. The shaft is aligned by an air bearing and has an air gage to sense vertical displacement caused by weights placed on the top end of the shaft. (AEC)

  2. Selenium mass balance in the Great Salt Lake, Utah

    USGS Publications Warehouse

    Diaz, X.; Johnson, W.P.; Naftz, D.L.

    2009-01-01

    A mass balance for Se in the south arm of the Great Salt Lake was developed for September 2006 to August 2007 of monitoring for Se loads and removal flows. The combined removal flows (sedimentation and volatilization) totaled to a geometric mean value of 2079??kg Se/yr, with the estimated low value being 1255??kg Se/yr, and an estimated high value of 3143??kg Se/yr at the 68% confidence level. The total (particulates + dissolved) loads (via runoff) were about 1560??kg Se/yr, for which the error is expected to be ?? 15% for the measured loads. Comparison of volatilization to sedimentation flux demonstrates that volatilization rather than sedimentation is likely the major mechanism of selenium removal from the Great Salt Lake. The measured loss flows balance (within the range of uncertainties), and possibly surpass, the measured annual loads. Concentration histories were modeled using a simple mass balance, which indicated that no significant change in Se concentration was expected during the period of study. Surprisingly, the measured total Se concentration increased during the period of the study, indicating that the removal processes operate at their low estimated rates, and/or there are unmeasured selenium loads entering the lake. The selenium concentration trajectories were compared to those of other trace metals to assess the significance of selenium concentration trends. ?? 2008 Elsevier B.V.

  3. Selenium mass balance in the Great Salt Lake, Utah.

    PubMed

    Diaz, Ximena; Johnson, William P; Naftz, David L

    2009-03-15

    A mass balance for Se in the south arm of the Great Salt Lake was developed for September 2006 to August 2007 of monitoring for Se loads and removal flows. The combined removal flows (sedimentation and volatilization) totaled to a geometric mean value of 2079 kg Se/yr, with the estimated low value being 1255 kg Se/yr, and an estimated high value of 3143 kg Se/yr at the 68% confidence level. The total (particulates+dissolved) loads (via runoff) were about 1560 kg Se/yr, for which the error is expected to be +/-15% for the measured loads. Comparison of volatilization to sedimentation flux demonstrates that volatilization rather than sedimentation is likely the major mechanism of selenium removal from the Great Salt Lake. The measured loss flows balance (within the range of uncertainties), and possibly surpass, the measured annual loads. Concentration histories were modeled using a simple mass balance, which indicated that no significant change in Se concentration was expected during the period of study. Surprisingly, the measured total Se concentration increased during the period of the study, indicating that the removal processes operate at their low estimated rates, and/or there are unmeasured selenium loads entering the lake. The selenium concentration trajectories were compared to those of other trace metals to assess the significance of selenium concentration trends.

  4. Efficient Solutions in Load Planning

    DTIC Science & Technology

    2004-04-01

    The current load planning capability is achieved through a conference and the use of a trim and stability tool. In order to make this process more...mathematical modelling of combustion processes , especially concentrating on spontaneous ignition. Jane works in the Amphibious and Mine Warfare...directives, (b) amphibious planning process and (c) mounting, embarkation and landing planning. It is with stage (c) that this paper is concerned. "Plans

  5. Culture and Achievement Motivation

    ERIC Educational Resources Information Center

    Maehr, Martin L.

    1974-01-01

    A framework is suggested for the cross-cultural study of motivation that stresses the importance of contextual conditions in eliciting achievement motivation and emphasizes cultural relativity in the definition of the concept. (EH)

  6. Achieving Salary Equity

    ERIC Educational Resources Information Center

    Nevill, Dorothy D.

    1975-01-01

    Three techniques are outlined for use by higher education institutions to achieve salary equity: salary prediction (using various statistical procedures), counterparting (comparing salaries of persons of similar rank), and grievance procedures. (JT)

  7. Rotating Balances Used for Fluid Pump Testing

    NASA Technical Reports Server (NTRS)

    Skelley, Stephen; Mulder, Andrew

    2014-01-01

    Marshall Space Flight Center has developed and demonstrated two direct read force and moment balances for sensing and resolving the hydrodynamic loads on rotating fluid machinery. These rotating balances consist of a series of stainless steel flexures instrumented with semiconductor type, unidirectional strain gauges arranged into six bridges, then sealed and waterproofed, for use fully submerged in degassed water at rotational speeds up to six thousand revolutions per minute. The balances are used to measure the forces and moments due to the onset and presence of cavitation or other hydrodynamic phenomena on subscale replicas of rocket engine turbomachinery, principally axial pumps (inducers) designed specifically to operate in a cavitating environment. The balances are inserted into the drive assembly with power to and signal from the sensors routed through the drive shaft and out through an air-cooled twenty-channel slip ring. High frequency data - balance forces and moments as well as extensive, flush-mounted pressures around the rotating component periphery - are acquired via a high-speed analog to digital data acquisition system while the test rig conditions are varied continuously. The data acquisition and correction process is described, including the in-situ verifications that are performed to quantify and correct for known system effects such as mechanical imbalance, "added mass," buoyancy, mechanical resonance, and electrical bias. Examples of four types of cavitation oscillations for two typical inducers are described in the laboratory (pressure) and rotating (force) frames: 1) attached, symmetric cavitation, 2) rotating cavitation, 3) attached, asymmetric cavitation, and 4) cavitation surge. Rotating and asymmetric cavitation generate a corresponding unbalanced radial force on the rotating assembly while cavitation surge generates an axial force. Attached, symmetric cavitation induces no measurable force. The frequency of the forces can be determined a

  8. Improving Balance with Tai Chi

    MedlinePlus

    ... 8428 · INFO @ VESTIBULAR . ORG · WWW . VESTIBULAR . ORG Improving Balance with Tai Chi By the Vestibular Disorders Association ... symptoms commonly experi- enced with vestibular (inner ear balance) disorders can cause overwhelming fatigue and anxiety. Many ...

  9. 46 CFR 39.4005 - Operational requirements for vapor balancing-TB/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 1 2014-10-01 2014-10-01 false Operational requirements for vapor balancing-TB/ALL. 39... SYSTEMS Vessel-to-Vessel Transfers Using Vapor Balancing § 39.4005 Operational requirements for vapor balancing—TB/ALL. (a) During a vessel-to-vessel transfer operation, each cargo tank being loaded must...

  10. 46 CFR 39.4005 - Operational requirements for vapor balancing-TB/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 1 2013-10-01 2013-10-01 false Operational requirements for vapor balancing-TB/ALL. 39... SYSTEMS Vessel-to-Vessel Transfers Using Vapor Balancing § 39.4005 Operational requirements for vapor balancing—TB/ALL. (a) During a vessel-to-vessel transfer operation, each cargo tank being loaded must...

  11. A MASS BALANCE OF SURFACE WATER GENOTOXICITY IN PROVIDENCE RIVER (RHODE ISLAND USA)

    EPA Science Inventory

    White and Rasmussen (Mutation Res. 410:223-236) used a mass balance approach to demonstrate that over 85% of the total genotoxic loading to the St. Lawrence River at Montreal is non-industrial. To validate the mass balance approach and investigate the sources of genotoxins in sur...

  12. Simultaneous saccharification and ethanol fermentation at high corn stover solids loading in a helical stirring bioreactor.

    PubMed

    Zhang, Jian; Chu, Deqiang; Huang, Juan; Yu, Zhanchun; Dai, Gance; Bao, Jie

    2010-03-01

    The higher ethanol titer inevitably requires higher solids loading during the simultaneous enzymatic saccharification and fermentation (SSF) using lignocellulose as the feedstock. The mixing between the solid lignocellulose and the liquid enzyme is crucially important. In this study, a bioreactor with a novel helical impeller was designed and applied to the SSF operation of the steam explosion pretreated corn stover under different solids loadings and different enzyme dosages. The performances using the helical impeller and the common Rushton impeller were compared and analyzed by measuring rheological properties and the mixing energy consumption. The results showed that the new designed stirring system had better performances in the saccharification yield, ethanol titer, and energy cost than those of the Rushton impeller stirring. The mixing energy consumption under different solids loadings and enzyme dosages during SSF operation were analyzed and compared to the thermal energy in the ethanol produced. A balance for achieving the optimal energy cost between the increased mixing energy cost and the reduced distillation energy cost at the high solids loading should be made. The potentials of the new bioreactor were tested under various SSF conditions for obtaining optimal ethanol yield and titer.

  13. More on Chemical Reaction Balancing.

    ERIC Educational Resources Information Center

    Swinehart, D. F.

    1985-01-01

    A previous article stated that only the matrix method was powerful enough to balance a particular chemical equation. Shows how this equation can be balanced without using the matrix method. The approach taken involves writing partial mathematical reactions and redox half-reactions, and combining them to yield the final balanced reaction. (JN)

  14. The balanced scorecard: an integrative approach to performance evaluation.

    PubMed

    Oliveira, J

    2001-05-01

    In addition to strict financial outcomes, healthcare financial managers should assess intangible assets that affect the organization's bottom line, such as clinical processes, staff skills, and patient satisfaction and loyalty. The balanced scorecard, coupled with data-warehousing capabilities, offers a way to measure an organization's performance against its strategic objectives while focusing on building capabilities to achieve these objectives. The balanced scorecard examines performance related to finance, human resources, internal processes, and customers. Because the balanced scorecard requires substantial amounts of data, it is a necessity to establish an organizational data warehouse of clinical, operational, and financial data that can be used in decision support. Because it presents indicators that managers and staff can influence directly by their actions, the balanced-scorecard approach to performance measurement encourages behavioral changes aimed at achieving corporate strategies.

  15. Dynamic balance abilities of collegiate men for the bench press.

    PubMed

    Piper, Timothy J; Radlo, Steven J; Smith, Thomas J; Woodward, Ryan W

    2012-12-01

    This study investigated the dynamic balance detection ability of college men for the bench press exercise. Thirty-five college men (mean ± SD: age = 22.4 ± 2.76 years, bench press experience = 8.3 ± 2.79 years, and estimated 1RM = 120.1 ± 21.8 kg) completed 1 repetition of the bench press repetitions for each of 3 bar loading arrangements. In a randomized fashion, subjects performed the bench press with a 20-kg barbell loaded with one of the following: a balanced load, one 20-kg plate on each side; an imbalanced asymmetrical load, one 20-kg plate on one side and a 20-kg plate plus a 1.25-kg plate on the other side; or an imbalanced asymmetrical center of mass, 20-kg plate on one side and sixteen 1.25-kg plates on the other side. Subjects were blindfolded and wore ear protection throughout all testing to decrease the ability to otherwise detect loads. Binomial data analysis indicated that subjects correctly detected the imbalance of the imbalanced asymmetrical center of mass condition (p[correct detection] = 0.89, p < 0.01) but did not correctly detect the balanced condition (p[correct detection] = 0.46, p = 0.74) or the imbalanced asymmetrical condition (p[correct detection] = 0.60, p = 0.31). Although it appears that a substantial shift in the center of mass of plates leads to the detection of barbell imbalance, minor changes of the addition of 1.25 kg (2.5 lb) to the asymmetrical condition did not result in consistent detection. Our data indicate that the establishment of a biofeedback loop capable of determining balance detection was only realized under a high degree of imbalance. Although balance detection was not present in either the even or the slightly uneven loading condition, the inclusion of balance training for upper body may be futile if exercises are unable to establish such a feedback loop and thus eliciting an improvement of balance performance.

  16. Lesson "Balance in Nature

    NASA Astrophysics Data System (ADS)

    Chapanova, V.

    2012-04-01

    Lesson "Balance in Nature" This simulation game-lesson (Balance in Nature) gives an opportunity for the students to show creativity, work independently, and to create models and ideas. It creates future-oriented thought connected to their experience, allowing them to propose solutions for global problems and personal responsibility for their activities. The class is divided in two teams. Each team chooses questions. 1. Question: Pollution in the environment. 2. Question: Care for nature and climate. The teams work on the chosen tasks. They make drafts, notes and formulate their solutions on small pieces of paper, explaining the impact on nature and society. They express their points of view using many different opinions. This generates alternative thoughts and results in creative solutions. With the new knowledge and positive behaviour defined, everybody realizes that they can do something positive towards nature and climate problems and the importance of individuals for solving global problems is evident. Our main goal is to recover the ecological balance, and everybody explains his or her own well-grounded opinions. In this work process the students obtain knowledge, skills and more responsible behaviour. This process, based on his or her own experience, dialogue and teamwork, helps the participant's self-development. Making the model "human↔ nature" expresses how human activities impact the natural Earth and how these impacts in turn affect society. Taking personal responsibility, we can reduce global warming and help the Earth. By helping nature we help ourselves. Teacher: Veselina Boycheva-Chapanova " Saint Patriarch Evtimii" Scholl Str. "Ivan Vazov"-19 Plovdiv Bulgaria

  17. Supporting clinician educators to achieve “work-work balance”

    PubMed Central

    Maniate, Jerry; Dath, Deepak; Cooke, Lara; Leslie, Karen; Snell, Linda; Busari, Jamiu

    2016-01-01

    Clinician Educators (CE) have numerous responsibilities in different professional domains, including clinical, education, research, and administration. Many CEs face tensions trying to manage these often competing professional responsibilities and achieve “work-work balance.” Rich discussions of techniques for work-work balance amongst CEs at a medical education conference inspired the authors to gather, analyze, and summarize these techniques to share with others. In this paper we present the CE’s “Four Ps”; these are practice points that support both the aspiring and established CE to help improve their performance and productivity as CEs, and allow them to approach work-work balance. PMID:28344698

  18. The balanced scorecard: sustainable performance assessment for forensic laboratories.

    PubMed

    Houck, Max; Speaker, Paul J; Fleming, Arron Scott; Riley, Richard A

    2012-12-01

    The purpose of this article is to introduce the concept of the balanced scorecard into the laboratory management environment. The balanced scorecard is a performance measurement matrix designed to capture financial and non-financial metrics that provide insight into the critical success factors for an organization, effectively aligning organization strategy to key performance objectives. The scorecard helps organizational leaders by providing balance from two perspectives. First, it ensures an appropriate mix of performance metrics from across the organization to achieve operational excellence; thereby the balanced scorecard ensures that no single or limited group of metrics dominates the assessment process, possibly leading to long-term inferior performance. Second, the balanced scorecard helps leaders offset short term performance pressures by giving recognition and weight to long-term laboratory needs that, if not properly addressed, might jeopardize future laboratory performance.

  19. Micromechanical Oscillating Mass Balance

    NASA Technical Reports Server (NTRS)

    Altemir, David A. (Inventor)

    1997-01-01

    A micromechanical oscillating mass balance and method adapted for measuring minute quantities of material deposited at a selected location, such as during a vapor deposition process. The invention comprises a vibratory composite beam which includes a dielectric layer sandwiched between two conductive layers. The beam is positioned in a magnetic field. An alternating current passes through one conductive layers, the beam oscillates, inducing an output current in the second conductive layer, which is analyzed to determine the resonant frequency of the beam. As material is deposited on the beam, the mass of the beam increases and the resonant frequency of the beam shifts, and the mass added is determined.

  20. Neurofeedback and physical balance in Parkinson's patients.

    PubMed

    Azarpaikan, Atefeh; Torbati, Hamidreza Taherii; Sohrabi, Mehdi

    2014-01-01

    The primary goal of the present research is to study the effect of a neurofeedback training (NFT) period on balance problems associated with Parkinson's disease. Sixteen patients were selected through purposive sampling and were randomly divided into experimental and control groups. The research procedure included eight sessions. Prior to and after training, pre-tests and post-tests of static and dynamic balance were administered using "limit of stability" for the Biodex as well as the Berg scale. The results revealed that, after neurofeedback training, a statistically significant improvement in both static and dynamic balance in the experimental group was achieved. The means of the Biodex and Berg scores in the experimental group increased from 18.87 to 42.87 and 17.62 to 46.37, respectively. The means of the Biodex and Berg scores in the control group in the pretest were 18.25 and 17.75 and increased to 20.00 and 20.50, respectively. The results suggest that NFT can improve static and dynamic balance in PD patients.

  1. Citraturic response to oral citric acid load

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Alpern, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    It is possible that some orally administered citrate may appear in urine by escaping oxidation in vivo. To determine whether this mechanism contributes to the citraturic response to potassium citrate, we measured serum and urinary citrate for 4 hours after a single oral load of citric acid (40 mEq.) in 6 normal subjects. Since citric acid does not alter acid-base balance, the effect of absorbed citrate could be isolated from that of alkali load. Serum citrate concentration increased significantly (p less than 0.05) 30 minutes after a single oral dose of citric acid and remained significantly elevated for 3 hours after citric acid load. Commensurate with this change, urinary citrate excretion peaked at 2 hours and gradually decreased during the next 2 hours after citric acid load. In contrast, serum and urinary citrate remained unaltered following the control load (no drug). Differences of the citratemic and citraturic effects between phases were significant (p less than 0.05) at 2 and 3 hours. Urinary pH, carbon dioxide pressure, bicarbonate, total carbon dioxide and ammonium did not change at any time after citric acid load, and did not differ between the 2 phases. No significant difference was noted in serum electrolytes, arterialized venous pH and carbon dioxide pressure at any time after citric acid load and between the 2 phases. Thus, the citraturic and citratemic effects of oral citric acid are largely accountable by provision of absorbed citrate, which has escaped in vivo degradation.

  2. Analysis of Sting Balance Calibration Data Using Optimized Regression Models

    NASA Technical Reports Server (NTRS)

    Ulbrich, Norbert; Bader, Jon B.

    2009-01-01

    Calibration data of a wind tunnel sting balance was processed using a search algorithm that identifies an optimized regression model for the data analysis. The selected sting balance had two moment gages that were mounted forward and aft of the balance moment center. The difference and the sum of the two gage outputs were fitted in the least squares sense using the normal force and the pitching moment at the balance moment center as independent variables. The regression model search algorithm predicted that the difference of the gage outputs should be modeled using the intercept and the normal force. The sum of the two gage outputs, on the other hand, should be modeled using the intercept, the pitching moment, and the square of the pitching moment. Equations of the deflection of a cantilever beam are used to show that the search algorithm s two recommended math models can also be obtained after performing a rigorous theoretical analysis of the deflection of the sting balance under load. The analysis of the sting balance calibration data set is a rare example of a situation when regression models of balance calibration data can directly be derived from first principles of physics and engineering. In addition, it is interesting to see that the search algorithm recommended the same regression models for the data analysis using only a set of statistical quality metrics.

  3. Balance ability and athletic performance.

    PubMed

    Hrysomallis, Con

    2011-03-01

    The relationship between balance ability and sport injury risk has been established in many cases, but the relationship between balance ability and athletic performance is less clear. This review compares the balance ability of athletes from different sports, determines if there is a difference in balance ability of athletes at different levels of competition within the same sport, determines the relationship of balance ability with performance measures and examines the influence of balance training on sport performance or motor skills. Based on the available data from cross-sectional studies, gymnasts tended to have the best balance ability, followed by soccer players, swimmers, active control subjects and then basketball players. Surprisingly, no studies were found that compared the balance ability of rifle shooters with other athletes. There were some sports, such as rifle shooting, soccer and golf, where elite athletes were found to have superior balance ability compared with their less proficient counterparts, but this was not found to be the case for alpine skiing, surfing and judo. Balance ability was shown to be significantly related to rifle shooting accuracy, archery shooting accuracy, ice hockey maximum skating speed and simulated luge start speed, but not for baseball pitching accuracy or snowboarding ranking points. Prospective studies have shown that the addition of a balance training component to the activities of recreationally active subjects or physical education students has resulted in improvements in vertical jump, agility, shuttle run and downhill slalom skiing. A proposed mechanism for the enhancement in motor skills from balance training is an increase in the rate of force development. There are limited data on the influence of balance training on motor skills of elite athletes. When the effectiveness of balance training was compared with resistance training, it was found that resistance training produced superior performance results for

  4. SALT and Spelling Achievement.

    ERIC Educational Resources Information Center

    Nelson, Joan

    A study investigated the effects of suggestopedic accelerative learning and teaching (SALT) on the spelling achievement, attitudes toward school, and memory skills of fourth-grade students. Subjects were 20 male and 28 female students from two self-contained classrooms at Kennedy Elementary School in Rexburg, Idaho. The control classroom and the…

  5. Iowa Women of Achievement.

    ERIC Educational Resources Information Center

    Ohrn, Deborah Gore, Ed.

    1993-01-01

    This issue of the Goldfinch highlights some of Iowa's 20th century women of achievement. These women have devoted their lives to working for human rights, education, equality, and individual rights. They come from the worlds of politics, art, music, education, sports, business, entertainment, and social work. They represent Native Americans,…

  6. Schools Achieving Gender Equity.

    ERIC Educational Resources Information Center

    Revis, Emma

    This guide is designed to assist teachers presenting the Schools Achieving Gender Equity (SAGE) curriculum for vocational education students, which was developed to align gender equity concepts with the Kentucky Education Reform Act (KERA). Included in the guide are lesson plans for classes on the following topics: legal issues of gender equity,…

  7. Achieving Peace through Education.

    ERIC Educational Resources Information Center

    Clarken, Rodney H.

    While it is generally agreed that peace is desirable, there are barriers to achieving a peaceful world. These barriers are classified into three major areas: (1) an erroneous view of human nature; (2) injustice; and (3) fear of world unity. In a discussion of these barriers, it is noted that although the consciousness and conscience of the world…

  8. Explorations in achievement motivation

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.

    1982-01-01

    Recent research on the nature of achievement motivation is reviewed. A three-factor model of intrinsic motives is presented and related to various criteria of performance, job satisfaction and leisure activities. The relationships between intrinsic and extrinsic motives are discussed. Needed areas for future research are described.

  9. Increasing Male Academic Achievement

    ERIC Educational Resources Information Center

    Jackson, Barbara Talbert

    2008-01-01

    The No Child Left Behind legislation has brought greater attention to the academic performance of American youth. Its emphasis on student achievement requires a closer analysis of assessment data by school districts. To address the findings, educators must seek strategies to remedy failing results. In a mid-Atlantic district of the Unites States,…

  10. Appraising Reading Achievement.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    To determine quality sequence in pupil progress, evaluation approaches need to be used which guide the teacher to assist learners to attain optimally. Teachers must use a variety of procedures to appraise student achievement in reading, because no one approach is adequate. Appraisal approaches might include: (1) observation and subsequent…

  11. Cognitive Processes and Achievement.

    ERIC Educational Resources Information Center

    Hunt, Dennis; Randhawa, Bikkar S.

    For a group of 165 fourth- and fifth-grade students, four achievement test scores were correlated with success on nine tests designed to measure three cognitive functions: sustained attention, successive processing, and simultaneous processing. This experiment was designed in accordance with Luria's model of the three functional units of the…

  12. Graders' Mathematics Achievement

    ERIC Educational Resources Information Center

    Bond, John B.; Ellis, Arthur K.

    2013-01-01

    The purpose of this experimental study was to investigate the effects of metacognitive reflective assessment instruction on student achievement in mathematics. The study compared the performance of 141 students who practiced reflective assessment strategies with students who did not. A posttest-only control group design was employed, and results…

  13. Achieving All Our Ambitions

    ERIC Educational Resources Information Center

    Hartley, Tricia

    2009-01-01

    National learning and skills policy aims both to build economic prosperity and to achieve social justice. Participation in higher education (HE) has the potential to contribute substantially to both aims. That is why the Campaign for Learning has supported the ambition to increase the proportion of the working-age population with a Level 4…

  14. Improving Educational Achievement.

    ERIC Educational Resources Information Center

    New York University Education Quarterly, 1979

    1979-01-01

    This is a slightly abridged version of the report of the National Academy of Education panel, convened at the request of HEW Secretary Joseph Califano and Assistant Secretary for Education Mary F. Berry, to study recent declines in student achievement and methods of educational improvement. (SJL)

  15. The Achievement Club

    ERIC Educational Resources Information Center

    Rogers, Ibram

    2009-01-01

    When Gabrielle Carpenter became a guidance counselor in Northern Virginia nine years ago, she focused on the academic achievement gap and furiously tried to close it. At first, she was compelled by tremendous professional interest. However, after seeing her son lose his zeal for school, Carpenter joined forces with other parents to form an…

  16. Achievement in Problem Solving

    ERIC Educational Resources Information Center

    Friebele, David

    2010-01-01

    This Action Research Project is meant to investigate the effects of incorporating research-based instructional strategies into instruction and their subsequent effect on student achievement in the area of problem-solving. The two specific strategies utilized are the integration of manipulatives and increased social interaction on a regular basis.…

  17. Essays on Educational Achievement

    ERIC Educational Resources Information Center

    Ampaabeng, Samuel Kofi

    2013-01-01

    This dissertation examines the determinants of student outcomes--achievement, attainment, occupational choices and earnings--in three different contexts. The first two chapters focus on Ghana while the final chapter focuses on the US state of Massachusetts. In the first chapter, I exploit the incidence of famine and malnutrition that resulted to…

  18. Advancing Student Achievement

    ERIC Educational Resources Information Center

    Walberg, Herbert J.

    2010-01-01

    For the last half century, higher spending and many modern reforms have failed to raise the achievement of students in the United States to the levels of other economically advanced countries. A possible explanation, says Herbert Walberg, is that much current education theory is ill informed about scientific psychology, often drawing on fads and…

  19. NCLB: Achievement Robin Hood?

    ERIC Educational Resources Information Center

    Bracey, Gerald W.

    2008-01-01

    In his "Wall Street Journal" op-ed on the 25th of anniversary of "A Nation At Risk", former assistant secretary of education Chester E. Finn Jr. applauded the report for turning U.S. education away from equality and toward achievement. It was not surprising, then, that in mid-2008, Finn arranged a conference to examine the…

  20. "Postural first" principle when balance is challenged in elderly people.

    PubMed

    Lion, Alexis; Spada, Rosario S; Bosser, Gilles; Gauchard, Gérome C; Anello, Guido; Bosco, Paolo; Calabrese, Santa; Iero, Antonella; Stella, Giuseppe; Elia, Maurizio; Perrin, Philippe P

    2014-08-01

    Human cognitive processing limits can lead to difficulties in performing two tasks simultaneously. This study aimed to evaluate the effect of cognitive load on both simple and complex postural tasks. Postural control was evaluated in 128 noninstitutionalized elderly people (mean age = 73.6 ± 5.6 years) using a force platform on a firm support in control condition (CC) and mental counting condition (MCC) with eyes open (EO) and eyes closed (EC). Then, the same tests were performed on a foam support. Sway path traveled and area covered by the center of foot pressure were recorded, low values indicating efficient balance. On firm support, sway path was higher in MCC than in CC both in EO and EC conditions (p < 0.001). On foam support, sway path was higher in CC than in MCC in EC condition (p < 0.001), area being higher in CC than in MCC both in EO (p < 0.05) and EC (p < 0.001) conditions. The results indicate that cognitive load alters balance control in a simple postural task (i.e. on firm support), which is highlighted by an increase of energetic expenditure (i.e. increase of the sway path covered) to balance. Awareness may not be increased and the attentional demand may be shared between balance and mental task. Conversely, cognitive load does not perturb the realization of a new complex postural task. This result showed that postural control is prioritized ("postural first" principle) when seriously challenged.

  1. Effects of Deployment on Musculoskeletal and Physiological Characteristics and Balance.

    PubMed

    Nagai, Takashi; Abt, John P; Sell, Timothy C; Keenan, Karen A; McGrail, Mark A; Smalley, Brian W; Lephart, Scott M

    2016-09-01

    Despite many nonbattle injuries reported during deployment, few studies have been conducted to evaluate the effects of deployment on musculoskeletal and physiological characteristics and balance. A total of 35 active duty U.S. Army Soldiers participated in laboratory testing before and after deployment to Afghanistan. The following measures were obtained for each Soldier: shoulder, trunk, hip, knee, and ankle strength and range of motion (ROM), balance, body composition, aerobic capacity, and anaerobic power/capacity. Additionally, Soldiers were asked about their physical activity and load carriage. Paired t tests or Wilcoxon tests with an α = 0.05 set a priori were used for statistical analyses. Shoulder external rotation ROM, torso rotation ROM, ankle dorsiflexion ROM, torso rotation strength, and anaerobic power significantly increased following deployment (p < 0.05). Shoulder extension ROM, shoulder external rotation strength, and eyes-closed balance (p < 0.05) were significantly worse following deployment. The majority of Soldiers (85%) engaged in physical activity. In addition, 58% of Soldiers reported regularly carrying a load (22 kg average). The deployment-related changes in musculoskeletal and physiological characteristics and balance as well as physical activity and load carriage during deployment may assist with proper preparation with the intent to optimize tactical readiness and mitigate injury risk.

  2. Development of a 5-Component Balance for Water Tunnel Applications

    NASA Technical Reports Server (NTRS)

    Suarez, Carlos J.; Kramer, Brian R.; Smith, Brooke C.

    1999-01-01

    The principal objective of this research/development effort was to develop a multi-component strain gage balance to measure both static and dynamic forces and moments on models tested in flow visualization water tunnels. A balance was designed that allows measuring normal and side forces, and pitching, yawing and rolling moments (no axial force). The balance mounts internally in the model and is used in a manner typical of wind tunnel balances. The key differences between a water tunnel balance and a wind tunnel balance are the requirement for very high sensitivity since the loads are very low (typical normal force is 90 grams or 0.2 lbs), the need for water proofing the gage elements, and the small size required to fit into typical water tunnel models. The five-component balance was calibrated and demonstrated linearity in the responses of the primary components to applied loads, very low interactions between the sections and no hysteresis. Static experiments were conducted in the Eidetics water tunnel with delta wings and F/A-18 models. The data were compared to forces and moments from wind tunnel tests of the same or similar configurations. The comparison showed very good agreement, providing confidence that loads can be measured accurately in the water tunnel with a relatively simple multi-component internal balance. The success of the static experiments encouraged the use of the balance for dynamic experiments. Among the advantages of conducting dynamic tests in a water tunnel are less demanding motion and data acquisition rates than in a wind tunnel test (because of the low-speed flow) and the capability of performing flow visualization and force/moment (F/M) measurements simultaneously with relative simplicity. This capability of simultaneous flow visualization and for F/M measurements proved extremely useful to explain the results obtained during these dynamic tests. In general, the development of this balance should encourage the use of water tunnels for a

  3. Implications of Dynamic Loading and Changing Climate on Mercury Bioaccumulation in a Planktivorous Fish (Orthodon microlepidotus)

    NASA Astrophysics Data System (ADS)

    Carroll, R. W. H.; Flickinger, A.; Warwick, J. J.; Schumer, R.

    2015-12-01

    A bioenergetic and mercury (Hg) mass balance (BioHg) model is developed for the Sacramento blackfish (Orthodon microlepidotus), a filter feeding cyprinid found in northern California and Nevada. Attention focuses on the Lahontan Reservoir in northern Nevada, which receives a strong temporally varying load of dissolved methylmercury (DMeHg) from the Carson River. Hg loads are the result of contaminated bank erosion during high flows and diffusion from bottom sediments during low flows. Coupling of dynamic reservoir loading with periods of maximum plankton growth and maximum fish consumption rates are required to explain the largest body burdens observed in the planktivore. In contrast, the large body burdens cannot be achieved using average water column concentrations. The United States Bureau of Reclamation has produced future streamflow estimates for 2000-2099 using 112 CMIP3 climate projections and the Variable Infiltration Capacity (VIC) model. These are used to drive a fully dynamic Hg transport model to assess changes in contaminant loading to the reservoir and implications on planktivorous bioaccumulation. Model results suggest the future loads of DMeHg entering the Lahontan Reservoir will decrease most significantly in the spring and summer due to channel width increases and depth decreases in the Carson River which reduce bank erosion over the century. The modeled concentrations of DMeHg in the reservoir are expected to increase during the summer due to a decrease in reservoir volume affecting the concentrations more than the decrease in loads, and the model results show that bioaccumulation levels may increase in the upstream sections of the reservoir while maintaining contamination levels above the federal action limit for human consumption in the lower reservoir.

  4. Micropollutant loads in the urban water cycle.

    PubMed

    Musolff, Andreas; Leschik, Sebastian; Reinstorf, Frido; Strauch, Gerhard; Schirmer, Mario

    2010-07-01

    The assessment of micropollutants in the urban aquatic environment is a challenging task since both the water balance and the contaminant concentrations are characterized by a pronounced variability in time and space. In this study the water balance of a central European urban drainage catchment is quantified for a period of one year. On the basis of a concentration monitoring of several micropollutants, a contaminant mass balance for the study area's wastewater, surface water, and groundwater is derived. The release of micropollutants from the catchment was mainly driven by the discharge of the wastewater treatment plant. However, combined sewer overflows (CSO) released significant loads of caffeine, bisphenol A, and technical 4-nonylphenol. Since an estimated fraction of 9.9-13.0% of the wastewater's dry weather flow was lost as sewer leakages to the groundwater, considerable loads of bisphenol A and technical 4-nonylphenol were also released by the groundwater pathway. The different temporal dynamics of release loads by CSO as an intermittent source and groundwater as well as treated wastewater as continuous pathways may induce acute as well as chronic effects on the receiving aquatic ecosystem. This study points out the importance of the pollution pathway CSO and groundwater for the contamination assessments of urban water resources.

  5. Evolving Sensitivity Balances Boolean Networks

    PubMed Central

    Luo, Jamie X.; Turner, Matthew S.

    2012-01-01

    We investigate the sensitivity of Boolean Networks (BNs) to mutations. We are interested in Boolean Networks as a model of Gene Regulatory Networks (GRNs). We adopt Ribeiro and Kauffman’s Ergodic Set and use it to study the long term dynamics of a BN. We define the sensitivity of a BN to be the mean change in its Ergodic Set structure under all possible loss of interaction mutations. Insilico experiments were used to selectively evolve BNs for sensitivity to losing interactions. We find that maximum sensitivity was often achievable and resulted in the BNs becoming topologically balanced, i.e. they evolve towards network structures in which they have a similar number of inhibitory and excitatory interactions. In terms of the dynamics, the dominant sensitivity strategy that evolved was to build BNs with Ergodic Sets dominated by a single long limit cycle which is easily destabilised by mutations. We discuss the relevance of our findings in the context of Stem Cell Differentiation and propose a relationship between pluripotent stem cells and our evolved sensitive networks. PMID:22586459

  6. SiGe BiCMOS balanced transmission line based on coplanar waveguide and split ring resonator

    NASA Astrophysics Data System (ADS)

    Serrano, Enrique; Borja, Alejandro L.; Boccia, Luigi; Cascon, Joaquin; Ibrahim, Safwat; Calzona, D.; Amendola, G.

    2016-06-01

    In this work, the design of a right-/left-handed composite transmission line implementation with passband characteristics is demonstrated on 0.13 µm silicon-germanium bipolar CMOS (SiGe BiCMOS) technology. The proposed structure is formed by a shorted coplanar waveguide transmission line loaded with split ring resonators (SRRs). As it will be shown, by controlling the geometry of the SRRs as well as their electric coupling with the host line, it is possible to achieve a balanced passband response with widespread bandwidth at millimeter wave frequencies. Besides, this paper introduces a configuration that allows to significantly lower the resonant frequency of the SRRs by loading the rings with Metal-Insulator-Metal capacitors. It will be illustrated how this approach allows to reduce the center band frequency of about 40% preserving the balanced behavior and without increasing the resonator size. Finally, the proposed design was experimentally validated with a prototype exhibiting an extended passband with a fractional bandwidth of 19.3% and -3.2 dB of insertion loss around the central frequency of 60 GHz. The use of these transmission lines can be foreseeing in high-capacity millimeter wave communication systems which require compact passband blocks integrated on chip.

  7. Calibration and Data Analysis of the MC-130 Air Balance

    NASA Technical Reports Server (NTRS)

    Booth, Dennis; Ulbrich, N.

    2012-01-01

    Design, calibration, calibration analysis, and intended use of the MC-130 air balance are discussed. The MC-130 balance is an 8.0 inch diameter force balance that has two separate internal air flow systems and one external bellows system. The manual calibration of the balance consisted of a total of 1854 data points with both unpressurized and pressurized air flowing through the balance. A subset of 1160 data points was chosen for the calibration data analysis. The regression analysis of the subset was performed using two fundamentally different analysis approaches. First, the data analysis was performed using a recently developed extension of the Iterative Method. This approach fits gage outputs as a function of both applied balance loads and bellows pressures while still allowing the application of the iteration scheme that is used with the Iterative Method. Then, for comparison, the axial force was also analyzed using the Non-Iterative Method. This alternate approach directly fits loads as a function of measured gage outputs and bellows pressures and does not require a load iteration. The regression models used by both the extended Iterative and Non-Iterative Method were constructed such that they met a set of widely accepted statistical quality requirements. These requirements lead to reliable regression models and prevent overfitting of data because they ensure that no hidden near-linear dependencies between regression model terms exist and that only statistically significant terms are included. Finally, a comparison of the axial force residuals was performed. Overall, axial force estimates obtained from both methods show excellent agreement as the differences of the standard deviation of the axial force residuals are on the order of 0.001 % of the axial force capacity.

  8. Improved Regression Analysis of Temperature-Dependent Strain-Gage Balance Calibration Data

    NASA Technical Reports Server (NTRS)

    Ulbrich, N.

    2015-01-01

    An improved approach is discussed that may be used to directly include first and second order temperature effects in the load prediction algorithm of a wind tunnel strain-gage balance. The improved approach was designed for the Iterative Method that fits strain-gage outputs as a function of calibration loads and uses a load iteration scheme during the wind tunnel test to predict loads from measured gage outputs. The improved approach assumes that the strain-gage balance is at a constant uniform temperature when it is calibrated and used. First, the method introduces a new independent variable for the regression analysis of the balance calibration data. The new variable is designed as the difference between the uniform temperature of the balance and a global reference temperature. This reference temperature should be the primary calibration temperature of the balance so that, if needed, a tare load iteration can be performed. Then, two temperature{dependent terms are included in the regression models of the gage outputs. They are the temperature difference itself and the square of the temperature difference. Simulated temperature{dependent data obtained from Triumph Aerospace's 2013 calibration of NASA's ARC-30K five component semi{span balance is used to illustrate the application of the improved approach.

  9. Balancing Family and Career

    NASA Astrophysics Data System (ADS)

    Andam, Aba Bentil; Dawson, Silvina Ponce; Horton, K. Renee; Sandow, Barbara

    2005-10-01

    In essentially all countries, responsibilities for child care, cooking, cleaning, and other homemaking tasks fall predominantly on the wife and mother. In addition, the childbearing years come during the period when a physicist must study hard, work long hours on research, and take temporary positions, often abroad. Thus, balancing family and career has long been one of the major barriers to women's participation in science and engineering fields, including physics. While many young women believe that they must choose between having children and having a science career, the fact is that the majority of women physicists in both developing and developed countries have successfully done both. This paper summarizes some ideas and recommendations raised in discussions, especially focused on easing the challenges of having children while in temporary jobs, returning to physics after a career break, the need for "family-friendly" working conditions, and the dual-career problem facing couples where both are scientists.

  10. Energy balance climate models

    NASA Technical Reports Server (NTRS)

    North, G. R.; Cahalan, R. F.; Coakley, J. A., Jr.

    1981-01-01

    An introductory survey of the global energy balance climate models is presented with an emphasis on analytical results. A sequence of increasingly complicated models involving ice cap and radiative feedback processes are solved, and the solutions and parameter sensitivities are studied. The model parameterizations are examined critically in light of many current uncertainties. A simple seasonal model is used to study the effects of changes in orbital elements on the temperature field. A linear stability theorem and a complete nonlinear stability analysis for the models are developed. Analytical solutions are also obtained for the linearized models driven by stochastic forcing elements. In this context the relation between natural fluctuation statistics and climate sensitivity is stressed.

  11. Skin friction balance

    NASA Technical Reports Server (NTRS)

    Ping, Tcheng (Inventor); Supplee, Frank H., Jr. (Inventor)

    1989-01-01

    A skin friction balance uses a parallel linkage mechanism to avoid inaccuracies in skin friction measurement attributable to off-center normal forces. The parallel linkage mechanism includes a stationary plate mounted in a cage, and an upper and lower movable plate which are linked to each other and to the stationary plate throught three vertical links. Flexure pivots are provided for pivotally connecting the links and the plates. A sensing element connected to the upper plate moves in response to skin friction, and the lower plate moves in the opposite direction of the upper plate. A force motor maintains a null position of the sensing element by exerting a restoring force in response to a signal generated by a linear variable differential transformer (LVDT).

  12. Complementary mechanisms for upright balance during walking

    PubMed Central

    Fettrow, Tyler D.; Thompson, Elizabeth D.; Agada, Peter; McFadyen, Bradford J.; Jeka, John J.

    2017-01-01

    Lateral balance is a critical factor in keeping the human body upright during walking. Two important mechanisms for balance control are the stepping strategy, in which the foot placement is changed in the direction of a sensed fall to modulate how the gravitational force acts on the body, and the lateral ankle strategy, in which the body mass is actively accelerated by an ankle torque. Currently, there is minimal evidence about how these two strategies complement one another to achieve upright balance during locomotion. We use Galvanic vestibular stimulation (GVS) to induce the sensation of a fall at heel-off during gait initiation. We found that young healthy adults respond to the illusory fall using both the lateral ankle strategy and the stepping strategy. The stance foot center of pressure (CoP) is shifted in the direction of the perceived fall by ≈2.5 mm, starting ≈247 ms after stimulus onset. The foot placement of the following step is shifted by ≈15 mm in the same direction. The temporal delay between these two mechanisms suggests that they independently contribute to upright balance during locomotion, potentially in a serially coordinated manner. Modeling results indicate that without the lateral ankle strategy, a much larger step width is required to maintain upright balance, suggesting that the small but early CoP shift induced by the lateral ankle strategy is critical for upright stability during locomotion. The relative importance of each mechanism and how neurological disorders may affect their implementation remain an open question. PMID:28234936

  13. Energy balance in peridynamics.

    SciTech Connect

    Lehoucq, Richard B.; Silling, Stewart Andrew

    2010-09-01

    The peridynamic model of solid mechanics treats internal forces within a continuum through interactions across finite distances. These forces are determined through a constitutive model that, in the case of an elastic material, permits the strain energy density at a point to depend on the collective deformation of all the material within some finite distance of it. The forces between points are evaluated from the Frechet derivative of this strain energy density with respect to the deformation map. The resulting equation of motion is an integro-differential equation written in terms of these interparticle forces, rather than the traditional stress tensor field. Recent work on peridynamics has elucidated the energy balance in the presence of these long-range forces. We have derived the appropriate analogue of stress power, called absorbed power, that leads to a satisfactory definition of internal energy. This internal energy is additive, allowing us to meaningfully define an internal energy density field in the body. An expression for the local first law of thermodynamics within peridynamics combines this mechanical component, the absorbed power, with heat transport. The global statement of the energy balance over a subregion can be expressed in a form in which the mechanical and thermal terms contain only interactions between the interior of the subregion and the exterior, in a form anticipated by Noll in 1955. The local form of this first law within peridynamics, coupled with the second law as expressed in the Clausius-Duhem inequality, is amenable to the Coleman-Noll procedure for deriving restrictions on the constitutive model for thermomechanical response. Using an idea suggested by Fried in the context of systems of discrete particles, this procedure leads to a dissipation inequality for peridynamics that has a surprising form. It also leads to a thermodynamically consistent way to treat damage within the theory, shedding light on how damage, including the

  14. Faculty achievement tracking tool.

    PubMed

    Pettus, Sarah; Reifschneider, Ellen; Burruss, Nancy

    2009-03-01

    Faculty development and scholarship is an expectation of nurse educators. Accrediting institutions, such as the Commission on Collegiate Nursing Education, the National League for Nursing Accrediting Commission, and the Higher Learning Commission, all have criteria regarding faculty achievement. A faculty achievement tracking tool (FATT) was developed to facilitate documentation of accreditation criteria attainment. Based on criteria from accrediting organizations, the roles that are addressed include scholarship, service, and practice. Definitions and benchmarks for the faculty as an aggregate are included. Undergoing reviews from different accrediting organizations, the FATT has been used once for accreditation of the undergraduate program and once for accreditation of the graduate program. The FATT is easy to use and has become an excellent adjunct for the preparation for accreditation reports. In addition, the FATT may be used for yearly evaluations, advancement, and merit.

  15. Project ACHIEVE final report

    SciTech Connect

    1997-06-13

    Project ACHIEVE was a math/science academic enhancement program aimed at first year high school Hispanic American students. Four high schools -- two in El Paso, Texas and two in Bakersfield, California -- participated in this Department of Energy-funded program during the spring and summer of 1996. Over 50 students, many of whom felt they were facing a nightmare future, were given the opportunity to work closely with personal computers and software, sophisticated calculators, and computer-based laboratories -- an experience which their regular academic curriculum did not provide. Math and science projects, exercises, and experiments were completed that emphasized independent and creative applications of scientific and mathematical theories to real world problems. The most important outcome was the exposure Project ACHIEVE provided to students concerning the college and technical-field career possibilities available to them.

  16. The Balanced Scorecard

    ERIC Educational Resources Information Center

    Kaplan, Robert S.; Miyake, Dylan N.

    2010-01-01

    Ten years ago, the Atlanta Public Schools had low and declining student achievement, demoralized teachers, crumbling buildings, high turnover among superintendents (average tenure of two years) and disaffected parents pulling their children out of the system. More than 60 percent of the city's high school students missed at least two weeks of…

  17. Load sensing system

    DOEpatents

    Sohns, Carl W.; Nodine, Robert N.; Wallace, Steven Allen

    1999-01-01

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

  18. Using Zero Balance Ultrafiltration with Dialysate as a Replacement Fluid for Hyperkalemia during Cardiopulmonary Bypass.

    PubMed

    Heath, Michele; Raghunathan, Karthik; Welsby, Ian; Maxwell, Cory

    2014-09-01

    Avoiding or managing hyperkalemia during cardiac surgery, especially in a patient with chronic renal insufficiency, can be challenging. Hyperkalemic cardioplegia solution is usually administered to achieve and maintain an electrical arrest of the heart. This solution eventually mixes in with the systemic circulation, contributing to elevated systemic potassium levels. Administration of packed red blood cells, hemolysis, tissue damage, and acidosis are also common causes of hyperkalemia. Current strategies to avoid or manage hyperkalemia include minimizing the volume of cardioplegia administered, shifting potassium from the extracellular into the intracellular space (by the administration of sodium bicarbonate when the pH is low and/or dextrose-insulin when effects relatively independent of serum pH are desired), using zero-balanced ultrafiltration (Z-BUF) with normal saline as the replacement fluid (to remove potassium from the body rather than simply shift the electrolyte across cellular membranes), and, occasionally, hemodialysis (1). We report the application of Z-BUF using an electrolyte-balanced, low potassium dialysate solution rather than isotonic saline to avoid a high chloride load and the potential for hyperchloremic acidosis to successfully treat hyperkalemia while on cardiopulmonary bypass.

  19. Rotor balancing apparatus and system

    NASA Technical Reports Server (NTRS)

    Lyman, Frank (Inventor); Lyman, Joseph (Inventor)

    1976-01-01

    Rotor balancing apparatus and a system comprising balance probes for measuring unbalance at the ends of a magnetically suspended rotor are disclosed. Each balance probe comprises a photocell which is located in relationship to the magnetically suspended rotor such that unbalance of the rotor changes the amount of light recorded by each photocell. The signal from each photocell is electrically amplified and displayed by a suitable device, such as an oscilloscope.

  20. The Effect of Load Position on Biomechanical and Physiological Measures during a Short Duration March

    DTIC Science & Technology

    2001-05-01

    completed subjective evaluations of the load location after each loaded trial. The questionnaire asked about overall acceptability, balance, thermal comfort , load... thermal comfort when marching Results The results of this study are summarized in Table 2. Oxygen consumption levels across load distributions were not...acceptable in 7 out of 8 categories that were examined. The alternate configuration ranked most acceptable in all categories except thermal comfort , where

  1. Haemostatic balance in cirrhosis.

    PubMed

    Baccouche, Héla; Labidi, Asma; Fekih, Monia; Mahjoub, Sonia; Kaabi, Houda; Hmida, Slama; Filali, Azza; Romdhane, Neila B

    2017-03-01

    Despite the prolongation of coagulation tests, recent studies reported an increased frequency of thromboembolic events in patients with cirrhosis. The aim of this study was to evaluate the haemostatic balance in cirrhotic patients through assessing the variation of pro- and anticoagulant factors and evaluating the in-vitro thrombin generation in patients with cirrhosis and in healthy patients. Fifty-one cirrhotic patients with or without thromboembolic events and 50 controls matched by age and sex were enrolled. Procoagulant (factors VII, II, V, VIII, and XII) and inhibitor (protein C, protein S and antithrombin) factor activities were determined. Thrombin generation was measured as endogenous thrombin potential (ETP). Haemostatic balance was assessed by means of both procoagulant to inhibitor coagulation factor ratios and ETP with to without protein C activation ratios. There were 24 males and 27 females. The mean age was 57.8 years [16-91 years]. Pro and anticoagulant factors were significantly lower in patients than in controls (P < 0.001) except for factor VIII and protein S. In fact factor VIII level was significantly higher in patients than in controls and protein S levels were not significantly different between patients and controls. Almost all the pro to anticoagulant factor ratios were higher in cirrhotics than in controls, especially the factor VIII to protein C ratios which increased significantly from Child Pugh A to C (P < 0.001), the ratio of ETP with to without protein C activator was higher in patients than in controls, but did not reach a significant level (0.8 vs. 0.52) There was no statistically significant difference between Child classes. When comparing patients with history of thrombosis (n = 7) to those matched by age and sex and without history of thrombosis (n = 14), the ratios were not statistically different between the two groups. Haemostatic changes in cirrhosis tend to rebalance the haemostatic system. This state often

  2. Load Model Data Tool

    SciTech Connect

    David Chassin, Pavel Etingov

    2013-04-30

    The LMDT software automates the process of the load composite model data preparation in the format supported by the major power system software vendors (GE and Siemens). Proper representation of the load composite model in power system dynamic analysis is very important. Software tools for power system simulation like GE PSLF and Siemens PSSE already include algorithms for the load composite modeling. However, these tools require that the input information on composite load to be provided in custom formats. Preparation of this data is time consuming and requires multiple manual operations. The LMDT software enables to automate this process. Software is designed to generate composite load model data. It uses the default load composition data, motor information, and bus information as an input. Software processes the input information and produces load composition model. Generated model can be stored in .dyd format supported by GE PSLF package or .dyr format supported by Siemens PSSE package.

  3. Load Induced Blindness

    PubMed Central

    Macdonald, James S. P.; Lavie, Nilli

    2008-01-01

    Although the perceptual load theory of attention has stimulated a great deal of research, evidence for the role of perceptual load in determining perception has typically relied on indirect measures that infer perception from distractor effects on reaction times or neural activity (see N. Lavie, 2005d`) was consistently reduced with high, compared to low, perceptual load but was unaffected by the level of working memory load. Because alternative accounts in terms of expectation, memory, response bias, and goal-neglect due to the more strenuous high load task were ruled out, these experiments clearly demonstrate that high perceptual load determines conscious perception, impairing the ability to merely detect the presence of a stimulus—a phenomenon of load induced blindness. PMID:18823196

  4. Characterization of flexure hinges for the French watt balance experiment

    NASA Astrophysics Data System (ADS)

    Pinot, Patrick; Genevès, Gérard

    2014-08-01

    In the French watt balance experiment, the translation and rotation functions must have no backlash, no friction, nor the need for lubricants. In addition errors in position and movement must be below 100 nm. Flexure hinges can meet all of these criteria. Different materials, profile shapes and machining techniques have been studied. The flexure pivots have been characterized using three techniques: 1) an optical microscope and, if necessary, a SEM to observe the surface inhomogeneities; 2) a mass comparator to determine the bending stiffness of unloaded pivots; 3) a loaded beam oscillating freely under vacuum to study the dynamic behavior of loaded pivots.

  5. Simulation of demand management and grid balancing with electric vehicles

    NASA Astrophysics Data System (ADS)

    Druitt, James; Früh, Wolf-Gerrit

    2012-10-01

    This study investigates the potential role of electric vehicles in an electricity network with a high contribution from variable generation such as wind power. Electric vehicles are modelled to provide demand management through flexible charging requirements and energy balancing for the network. Balancing applications include both demand balancing and vehicle-to-grid discharging. This study is configured to represent the UK grid with balancing requirements derived from wind generation calculated from weather station wind speeds on the supply side and National Grid data from on the demand side. The simulation models 1000 individual vehicle entities to represent the behaviour of larger numbers of vehicles. A stochastic trip generation profile is used to generate realistic journey characteristics, whilst a market pricing model allows charging and balancing decisions to be based on realistic market price conditions. The simulation has been tested with wind generation capacities representing up to 30% of UK consumption. Results show significant improvements to load following conditions with the introduction of electric vehicles, suggesting that they could substantially facilitate the uptake of intermittent renewable generation. Electric vehicle owners would benefit from flexible charging and selling tariffs, with the majority of revenue derived from vehicle-to-grid participation in balancing markets.

  6. Dynamic Balancing Of Turbomachinery Shafts And Rotors

    NASA Technical Reports Server (NTRS)

    Verhoff, Vincent G.

    1993-01-01

    Method for dynamic balancing of turbomachinery shafts and rotors developed with view toward reducing time spent in balancing process. Improved method based on existing dynamic-balancing techniques and equipment, incorporating use of balancing arbor, which is mandrel duplicating mounting geometry and dynamic-balance properties of shaft balanced. Once shaft balanced, not necessary to disassemble machinery and/or shaft completely and rebalance shaft when replacing rotor on shaft. Instead, one balances replacement rotor on balancing arbor, then installs balanced rotor on shaft.

  7. In the Balance:

    PubMed Central

    Weaver, Lawrence T.

    2010-01-01

    Summary The nineteenth century saw the incorporation of technology, such as the stethoscope, microscope, and thermometer, into clinical medicine. An instrument that has received less attention in the history of the role of technology in medicine is the weighing balance, or scale. Although not new to nineteenth-century medicine, it played an important part in the rise of the numerical method and its application to the development and shaping of pediatrics. This article explores the origin and development of the weighing of babies. During its clinical and scientific adoption, this simple procedure was refined and applied in a number of increasingly sophisticated and far-reaching ways: as a measure of the dimensions of the fetus and newborn, as an index of the viability of the newborn, as a means of estimating milk intake, as a way of distinguishing normality from abnormality, as a summary measure of infant health, and as an instrument of mass surveillance. In so doing it changed the way in which medical care was delivered to infants. PMID:20632732

  8. A Balanced Memory Network

    PubMed Central

    Roudi, Yasser; Latham, Peter E

    2007-01-01

    A fundamental problem in neuroscience is understanding how working memory—the ability to store information at intermediate timescales, like tens of seconds—is implemented in realistic neuronal networks. The most likely candidate mechanism is the attractor network, and a great deal of effort has gone toward investigating it theoretically. Yet, despite almost a quarter century of intense work, attractor networks are not fully understood. In particular, there are still two unanswered questions. First, how is it that attractor networks exhibit irregular firing, as is observed experimentally during working memory tasks? And second, how many memories can be stored under biologically realistic conditions? Here we answer both questions by studying an attractor neural network in which inhibition and excitation balance each other. Using mean-field analysis, we derive a three-variable description of attractor networks. From this description it follows that irregular firing can exist only if the number of neurons involved in a memory is large. The same mean-field analysis also shows that the number of memories that can be stored in a network scales with the number of excitatory connections, a result that has been suggested for simple models but never shown for realistic ones. Both of these predictions are verified using simulations with large networks of spiking neurons. PMID:17845070

  9. Balancing "we" and "me".

    PubMed

    Congdon, Christine; Flynn, Donna; Redman, Melanie

    2014-10-01

    The open office is the dominant form of workspace design for good reason: It fosters collaboration, promotes learning, and nurtures strong culture. But what most companies fail to realize is that collaboration has a natural rhythm that requires both interaction and private contemplation. Companies have been trying for decades to find the balance between public and private workspace that best supports collaboration. In 1980 52% of U.S. employees lacked workspaces where they could concentrate without distraction. In response, high-walled cubicles took over the corporate landscape. By the late 1990s, the tide had turned, and only 23% of employees wanted more privacy, and 50% wanted more access to other people. Ever since, firms have been beefing up spaces that support collaboration and shrinking areas for individual work. But the pendulum seems to have swung too far: Once again, people feel a pressing need for privacy, not only to do heads-down work but to cope with the intensity of work today. To address these needs, according to the authors, we have to rethink our assumptions about privacy. Traditionally defined in physical terms, privacy is now about the individual's ability to control information and stimulation. In this article, the authors examine workspace design through the new lens of privacy and offer insights on how to foster teamwork and solitude.

  10. Role of distal reabsorption and peritubular environment in glomerulotubular balance.

    NASA Technical Reports Server (NTRS)

    Schrier, R. W.; Humphreys, M. H.

    1972-01-01

    Total kidney glomerulotubular balance was examined during aortic constriction and release in saline-loaded dogs and in dogs undergoing water diuresis. Aortic constriction lowered the glomerular filtration rate by 45% in both groups, and glomerulotubular balance, as judged by changes in absolute sodium reabsorption, was also comparable. During water diuresis, a linear relationship was observed between free water clearance and urine flow during all maneuvers, suggesting that distal sodium reabsorption is related primarily to distal delivery. The results suggest that if alterations in the peritubular environment are responsible for the changes in tubular sodium reabsorption during aortic constriction in the saline- or water-loaded dog, then a change in renal plasma flow, and presumably delivery rate of oncotic force, may be the most likely mediator.

  11. Heat balance of the Earth

    NASA Technical Reports Server (NTRS)

    Budyko, M. I.; Berlyand, T. G.; Yefimova, N. A.; Zubenok, L. I.; Strokina, L. A.

    1980-01-01

    Results of improved calculations of the heat balance components of Earth's surface are reported for yearly average conditions. The technique used to determine the heat-balance components from land- and sea-based actinometric observations as well as from satellite data on the radiation balance of the Earth-atmosphere system is described, with special attention given to short-wavelength solar radiation on the continents, effective radiation from the land surface, the radiation balance of the ocean surface, heat expended by both evaporation from the ocean surface, and turbulent heat transfer between the ocean surface and the atmosphere. World maps of heat-balance components show yearly average values of total radiation, radiation balance, heat expended by evaporation, the turbulent heat flow between Earth's surface and atmosphere, and heat transfer between the ocean surface and underlying waters. The global surface heat balance is estimated along with global values of the various components and the heat-balance components for different latitude zones.

  12. Balancing Safety and Free Speech

    ERIC Educational Resources Information Center

    Hudson, David L., Jr.

    2004-01-01

    According to Jay Worona, general counsel for the New York State School Board Association, "Balancing safety and student constitutional rights is not easy. It has to be a careful balance. School officials must be prudent and not overreact. But one part of the equation has to be paramount. And safety should be the primary concern"…

  13. Vertical load capacities of roof truss cross members

    PubMed Central

    Gearhart, David F.; Morsy, Mohamed Khaled

    2016-01-01

    Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were conducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nominally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and 67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross members yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively. PMID:27547484

  14. Vertical load capacities of roof truss cross members.

    PubMed

    Gearhart, David F; Morsy, Mohamed Khaled

    2016-05-01

    Trusses used for roof support in coal mines are constructed of two grouted bolts installed at opposing forty-five degree angles into the roof and a cross member that ties the angled bolts together. The load on the cross member is vertical, which is transverse to the longitudinal axis, and therefore the cross member is loaded in the weakest direction. Laboratory tests were conducted to determine the vertical load capacity and deflection of three different types of cross members. Single-point load tests, with the load applied in the center of the specimen and double-point load tests, with a span of 2.4 m, were conducted. For the single-point load configuration, the yield of the 25 mm solid bar cross member was nominally 98 kN of vertical load, achieved at 42 cm of deflection. For cable cross members, yield was not achieved even after 45 cm of deflection. Peak vertical loads were about 89 kN for 17 mm cables and 67 kN for the 15 mm cables. For the double-point load configurations, the 25 mm solid bar cross members yielded at 150 kN of vertical load and 25 cm of deflection. At 25 cm of deflection individual cable strands started breaking at 133 and 111 kN of vertical load for the 17 and 15 mm cable cross members respectively.

  15. Achieving closure at Fernald

    SciTech Connect

    Bradburne, John; Patton, Tisha C.

    2001-02-25

    When Fluor Fernald took over the management of the Fernald Environmental Management Project in 1992, the estimated closure date of the site was more than 25 years into the future. Fluor Fernald, in conjunction with DOE-Fernald, introduced the Accelerated Cleanup Plan, which was designed to substantially shorten that schedule and save taxpayers more than $3 billion. The management of Fluor Fernald believes there are three fundamental concerns that must be addressed by any contractor hoping to achieve closure of a site within the DOE complex. They are relationship management, resource management and contract management. Relationship management refers to the interaction between the site and local residents, regulators, union leadership, the workforce at large, the media, and any other interested stakeholder groups. Resource management is of course related to the effective administration of the site knowledge base and the skills of the workforce, the attraction and retention of qualified a nd competent technical personnel, and the best recognition and use of appropriate new technologies. Perhaps most importantly, resource management must also include a plan for survival in a flat-funding environment. Lastly, creative and disciplined contract management will be essential to effecting the closure of any DOE site. Fluor Fernald, together with DOE-Fernald, is breaking new ground in the closure arena, and ''business as usual'' has become a thing of the past. How Fluor Fernald has managed its work at the site over the last eight years, and how it will manage the new site closure contract in the future, will be an integral part of achieving successful closure at Fernald.

  16. [Soft tissue balancing in total condylar knee arthroplasty].

    PubMed

    Trepte, C T; Pfanzelt, K

    2003-01-01

    Soft tissue balancing and correct bone cuts are an entity in correcting malalignment in total knee arthroplasty, and cannot be considered isolated. Distinct bony deformations/deviations need enlarged soft tissue management. The extent of resection of the bone stock has to be planned exactly before the operation. Exact soft tissue balancing is necessary to stabilize the corrected knee. Soft tissue balancing has to be done primarily on the side of the contracture by lengthening of the shortened and contracted structures. After balancing the ligaments should have the same tension in extension and flexion together with the same height of the extension and flexion gap. Because of the classic resection of the tibial head, the femoral resection must follow the Insall-Line, that means 3 degrees to 5 degrees outer rotation in relation to the condyles. Only in this way a symmetric flexion gap can be achieved in combination with ligamentous stability in extension and flexion.

  17. A Monte Carlo Analysis of Gas Centrifuge Enrichment Plant Process Load Cell Data

    SciTech Connect

    Garner, James R; Whitaker, J Michael

    2013-01-01

    As uranium enrichment plants increase in number, capacity, and types of separative technology deployed (e.g., gas centrifuge, laser, etc.), more automated safeguards measures are needed to enable the IAEA to maintain safeguards effectiveness in a fiscally constrained environment. Monitoring load cell data can significantly increase the IAEA s ability to efficiently achieve the fundamental safeguards objective of confirming operations as declared (i.e., no undeclared activities), but care must be taken to fully protect the operator s proprietary and classified information related to operations. Staff at ORNL, LANL, JRC/ISPRA, and University of Glasgow are investigating monitoring the process load cells at feed and withdrawal (F/W) stations to improve international safeguards at enrichment plants. A key question that must be resolved is what is the necessary frequency of recording data from the process F/W stations? Several studies have analyzed data collected at a fixed frequency. This paper contributes to load cell process monitoring research by presenting an analysis of Monte Carlo simulations to determine the expected errors caused by low frequency sampling and its impact on material balance calculations.

  18. Optimal Operation Method of Smart House by Controllable Loads based on Smart Grid Topology

    NASA Astrophysics Data System (ADS)

    Yoza, Akihiro; Uchida, Kosuke; Yona, Atsushi; Senju, Tomonobu

    2013-08-01

    From the perspective of global warming suppression and depletion of energy resources, renewable energy such as wind generation (WG) and photovoltaic generation (PV) are getting attention in distribution systems. Additionally, all electrification apartment house or residence such as DC smart house have increased in recent years. However, due to fluctuating power from renewable energy sources and loads, supply-demand balancing fluctuations of power system become problematic. Therefore, "smart grid" has become very popular in the worldwide. This article presents a methodology for optimal operation of a smart grid to minimize the interconnection point power flow fluctuations. To achieve the proposed optimal operation, we use distributed controllable loads such as battery and heat pump. By minimizing the interconnection point power flow fluctuations, it is possible to reduce the maximum electric power consumption and the electric cost. This system consists of photovoltaics generator, heat pump, battery, solar collector, and load. In order to verify the effectiveness of the proposed system, MATLAB is used in simulations.

  19. The consequences of balanced harvesting of fish communities

    PubMed Central

    Jacobsen, Nis S.; Gislason, Henrik; Andersen, Ken H.

    2014-01-01

    Balanced harvesting, where species or individuals are exploited in accordance with their productivity, has been proposed as a way to minimize the effects of fishing on marine fish communities and ecosystems. This calls for a thorough examination of the consequences balanced harvesting has on fish community structure and yield. We use a size- and trait-based model that resolves individual interactions through competition and predation to compare balanced harvesting with traditional selective harvesting, which protects juvenile fish from fishing. Four different exploitation patterns, generated by combining selective or unselective harvesting with balanced or unbalanced fishing, are compared. We find that unselective balanced fishing, where individuals are exploited in proportion to their productivity, produces a slightly larger total maximum sustainable yield than the other exploitation patterns and, for a given yield, the least change in the relative biomass composition of the fish community. Because fishing reduces competition, predation and cannibalism within the community, the total maximum sustainable yield is achieved at high exploitation rates. The yield from unselective balanced fishing is dominated by small individuals, whereas selective fishing produces a much higher proportion of large individuals in the yield. Although unselective balanced fishing is predicted to produce the highest total maximum sustainable yield and the lowest impact on trophic structure, it is effectively a fishery predominantly targeting small forage fish. PMID:24307676

  20. Nexus of poverty, energy balance and health.

    PubMed

    Mishra, C P

    2012-04-01

    Since the inception of planning process in India, health planning was an integral component of socio-economic planning. Recommendations of several committees, policy documents and Millennium development goals were instrumental in development of impressive health infrastructure. Several anti-poverty and employment generation programmes were instituted to remove poverty. Spectacular achievements took place in terms of maternal and child health indicators and expectancy of life at birth. However, communicable diseases and undernutrition remain cause of serious concern and non-communicable diseases are imposing unprecedented challenge to planners and policy makers. Estimates of poverty based on different criteria point that it has remained a sustained problem in the country and emphasizes on revisiting anti-poverty programmes, economic policies and social reforms. Poverty affects purchasing power and thereby, food consumption. Energy intake data has inherent limitations. It must be assessed in terms of energy expenditure. Energy balance has been least explored area of research. The studies conducted in three different representative population group of Eastern Uttar Pradesh revealed that 69.63% rural adolescent girls (10-19 years), 79.9% rural reproductive age group females and 62.3% rural geriatric subjects were in negative energy balance. Negative energy balance was significantly less in adolescent girls belonging to high SES (51.37%), having main occupation of family as business (55.3%), and highest per capita income group (57.1%) with respect to their corresponding sub-categories. In case of rural reproductive age groups, this was maximum (93.0%) in SC/ST category and least (65.7%) in upper caste group. In case of geriatric group, higher adjusted Odd's Ratio for negative energy balance for subjects not cared by family members (AOR 23.43, CI 3.93-139.56), not kept money (AOR 5.27, CI 1.58-17.56), belonging to lower and upper middle SES by Udai Pareekh Classification

  1. Integration of the response to a dietary potassium load: a paleolithic perspective.

    PubMed

    Kamel, Kamel S; Schreiber, Martin; Halperin, Mitchell L

    2014-05-01

    Our purpose is to integrate new insights in potassium (K(+)) physiology to understand K(+) homeostasis and illustrate some of their clinical implications. Since control mechanisms that are essential for survival were likely developed in Paleolithic times, we think the physiology of K(+) homeostasis can be better revealed when viewed from what was required to avoid threats and achieve balance in Paleolithic times. Three issues will be highlighted. First, we shall consider the integrative physiology of the gastrointestinal tract and the role of lactic acid released from enterocytes following absorption of sugars (fruit and berries) to cause a shift of this K(+) load into the liver. Second, we shall discuss the integrative physiology of WNK kinases and modulation of delivery of bicarbonate to the distal nephron to switch the aldosterone response from sodium chloride retention to K(+) secretion when faced with a K(+) load. Third, we shall emphasize the role of intra-renal recycling of urea in achieving K(+) homeostasis when the diet contains protein and K(+).

  2. Perceptual load influences selective attention across development.

    PubMed

    Couperus, Jane W

    2011-09-01

    Research suggests that visual selective attention develops across childhood. However, there is relatively little understanding of the neurological changes that accompany this development, particularly in the context of adult theories of selective attention, such as N. Lavie's (1995) perceptual load theory of attention. This study examined visual selective attention across development from 7 years of age to adulthood. Specifically, the author examined if changes in processing as a function of selective attention are similarly influenced by perceptual load across development. Participants were asked to complete a task at either low or high perceptual load while processing of an unattended probe stimulus was examined using event related potentials. Similar to adults, children and teens showed reduced processing of the unattended stimulus as perceptual load increased at the P1 visual component. However, although there were no qualitative differences in changes in processing, there were quantitative differences, with shorter P1 latencies in teens and adults compared with children, suggesting increases in the speed of processing across development. In addition, younger children did not need as high a perceptual load to achieve the same difference in performance between low and high perceptual load as adults. Thus, this study demonstrates that although there are developmental changes in visual selective attention, the mechanisms by which visual selective attention is achieved in children may share similarities with adults.

  3. Achievement Goals and Achievement Emotions: A Meta-Analysis

    ERIC Educational Resources Information Center

    Huang, Chiungjung

    2011-01-01

    This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

  4. Balance perturbation system to improve balance compensatory responses during walking in old persons

    PubMed Central

    2010-01-01

    Ageing commonly disrupts the balance control and compensatory postural responses that contribute to maintaining balance and preventing falls during perturbation of posture. This can lead to increased risk of falling in old adults (65 years old and over). Therefore, improving compensatory postural responses during walking is one of the goals in fall prevention programs. Training is often used to achieve this goal. Most fall prevention programs are usually directed towards improving voluntary postural control. Since compensatory postural responses triggered by a slip or a trip are not under direct volitional control these exercises are less expected to improve compensatory postural responses due to lack of training specificity. Thus, there is a need to investigate the use balance perturbations during walking to train more effectively compensatory postural reactions during walking. This paper describes the Balance Measure & Perturbation System (BaMPer System) a system that provides small, controlled and unpredictable perturbations during treadmill walking providing valuable perturbation, which allows training compensatory postural responses during walking which thus hypothesize to improve compensatory postural responses in older adults. PMID:20630113

  5. Phalange Tactile Load Cell

    NASA Technical Reports Server (NTRS)

    Ihrke, Chris A. (Inventor); Diftler, Myron A. (Inventor); Linn, Douglas Martin (Inventor); Platt, Robert (Inventor); Griffith, Bryan Kristian (Inventor)

    2010-01-01

    A tactile load cell that has particular application for measuring the load on a phalange in a dexterous robot system. The load cell includes a flexible strain element having first and second end portions that can be used to mount the load cell to the phalange and a center portion that can be used to mount a suitable contact surface to the load cell. The strain element also includes a first S-shaped member including at least three sections connected to the first end portion and the center portion and a second S-shaped member including at least three sections coupled to the second end portion and the center portion. The load cell also includes eight strain gauge pairs where each strain gauge pair is mounted to opposing surfaces of one of the sections of the S-shaped members where the strain gauge pairs provide strain measurements in six-degrees of freedom.

  6. Balancing Fun and Learning in a Serious Game Design

    ERIC Educational Resources Information Center

    Franzwa, Christopher; Tang, Ying; Johnson, Aaron; Bielefeldt, Talbot

    2014-01-01

    This article presents the underlying philosophy of Sustain City, an educational serious game system that engages students, particularly prospective and beginning science and engineering students, in a series of engineering design challenges. Various strategies implemented in Sustain City for achieving a balance of fun and learning are discussed,…

  7. Balancing Leadership and Personal Growth: The School Administrator's Guide

    ERIC Educational Resources Information Center

    Metzger, Christa

    2006-01-01

    After conducting intensive research and observations of school district superintendents, administrators, and school principals, the author offers strategies for achieving a healthy work and life balance, including: (1) Taking care of yourself as well as you do others; (2) Defining and applying the six themes of personal growth; (3) Nourishing your…

  8. Work-Family Balance and Academic Advancement in Medical Schools

    ERIC Educational Resources Information Center

    Fox, Geri; Schwartz, Alan; Hart, Katherine M.

    2006-01-01

    Objective: This study examines various options that a faculty member might exercise to achieve work-family balance in academic medicine and their consequences for academic advancement. Method: Three data sets were analyzed: an anonymous web-administered survey of part-time tenure track-eligible University of Illinois College of Medicine (UI-COM)…

  9. Balancing Process and Content in Groups: A Metaphor.

    ERIC Educational Resources Information Center

    Kraus, Kurt; Hulse-Killacky, Diana

    1996-01-01

    Through the use of a culinary metaphor, the authors depict common problems that can occur when process is overlooked in group settings. The metaphor offers "food for thought" for helping leaders achieve a balance between process and content in effective group work. (Author)

  10. Transportation Requirements for Improved Racial Balance. Research Memorandum No. 6.

    ERIC Educational Resources Information Center

    Ross, Howard R.; Moon, Albert E.

    This memorandum presents the costs of transporting students to achieve racial balance in the San Francisco public schools. The costs of a district owned school bus system are analyzed for a four year implementation period. Costs of different sizes and types of buses and of major operating requirements (including parking, buildings, staff, and…

  11. Antarctic mass balance changes from GRACE

    NASA Astrophysics Data System (ADS)

    Kallenberg, B.; Tregoning, P.

    2012-04-01

    The Antarctic ice sheet contains ~30 million km3 of ice and constitutes a significant component of the global water balance with enough freshwater to raise global sea level by ~60 m. Altimetry measurements and climate models suggest variable behaviour across the Antarctic ice sheet, with thickening occurring in a vast area of East Antarctica and substantial thinning in West Antarctica caused by increased temperature gradients in the surrounding ocean. However, the rate at which the polar ice cap is melting is still poorly constrained. To calculate the mass loss of an ice sheet it is necessary to separate present day mass balance changes from glacial isostatic adjustment (GIA), the response of the Earth's crust to mass loss, wherefore it is essential to undertake sufficient geological and geomorphological sampling. As there is only a limited possibility for this in Antarctica, all models (i.e. geological, hydrological as well as atmospheric) are very poorly constrained. Therefore, space-geodetic observations play an important role in detecting changes in mass and spatial variations in the Earth's gravity field. The Gravity Recovery And Climate Experiment (GRACE) observed spatial variations in the Earth's gravity field over the past ten years. The satellite detects mass variations in the Earth system including geophysical, hydrological and atmospheric shifts. GRACE itself is not able to separate the GIA from mass balance changes and, due to the insufficient geological and geomorphological database, it is not possible to model the GIA effect accurately for Antarctica. However, the results from GRACE can be compared with other scientific results, coming from other geodetic observations such as satellite altimetry and GPS or by the use of geological observations. In our contribution we compare the GRACE data with recorded precipitation patterns and mass anomalies over East Antarctica to separate the observed GRACE signal into its two components: GIA as a result of mass

  12. Voltage balanced multilevel voltage source converter system

    DOEpatents

    Peng, F.Z.; Lai, J.S.

    1997-07-01

    Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

  13. Voltage balanced multilevel voltage source converter system

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    1997-01-01

    A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

  14. Multiple needle puncturing: balancing the varus knee.

    PubMed

    Bellemans, Johan

    2011-09-09

    The so-called "pie crusting" technique using multiple stab incisions is a well-established procedure for correcting tightness of the iliotibial band in the valgus knee. It is, however, not applicable for balancing the medial side in varus knees because of the risk for iatrogenic transsection of the medial collateral ligament (MCL). This article presents our experience with a safer alternative and minimally invasive technique for medial soft tissue balancing, where we make multiple punctures in the MCL using a 19-gauge needle to progressively stretch the MCL until a correct ligament balance is achieved. Our technique requires minimal to no additional soft tissue dissection and can even be performed percutaneously when necessary. This technique, therefore, does not impact the length of the skin or soft tissue incisions. We analyzed 61 cases with varus deformity that were intraoperatively treated using this technique. In 4 other cases, the technique was used as a percutaneous procedure to correct postoperative medial tightness that caused persistent pain on the medial side. The procedure was considered successful when a 2- to 4-mm mediolateral joint line opening was obtained in extension and 2 to 6 mm in flexion. In 62 cases (95%), a progressive correction of medial tightness was achieved according to the above-described criteria. Three cases were overreleased and required compensatory release of the lateral structures and use of a thicker insert. Based on these results, we consider needle puncturing an effective and safe technique for progressive correction of MCL tightness during minimally invasive total knee arthroplasty.

  15. Development of Zinc/Bromine Batteries for Load-Leveling Applications: Phase 1 Final Report

    SciTech Connect

    Eidler, Phillip

    1999-07-01

    The Zinc/Bromine Load-Leveling Battery Development contract (No. 40-8965) was partitioned at the outset into two phases of equal length. Phase 1 started in September 1990 and continued through December 1991. In Phase 1, zinc/bromine battery technology was to be advanced to the point that it would be clear that the technology was viable and would be an appropriate choice for electric utilities wishing to establish stationary energy-storage facilities. Criteria were established that addressed most of the concerns that had been observed in the previous development efforts. The performances of 8-cell and 100-cell laboratory batteries demonstrated that the criteria were met or exceeded. In Phase 2, 100-kWh batteries will be built and demonstrated, and a conceptual design for a load-leveling plant will be presented. At the same time, work will continue to identify improved assembly techniques and operating conditions. This report details the results of the efforts carried out in Phase 1. The highlights are: (1) Four 1-kWh stacks achieved over 100 cycles, One l-kWh stack achieved over 200 cycles, One 1-kWh stack achieved over 300 cycles; (2) Less than 10% degradation in performance occurred in the four stacks that achieved over 100 cycles; (3) The battery used for the zinc loading investigation exhibited virtually no loss in performance for loadings up to 130 mAh/cm{sup 2}; (4) Charge-current densities of 50 ma/cm{sup 2} have been achieved in minicells; (5) Fourteen consecutive no-strip cycles have been conducted on the stack with 300+ cycles; (6) A mass and energy balance spreadsheet that describes battery operation was completed; (7) Materials research has continued to provide improvements in the electrode, activation layer, and separator; and (8) A battery made of two 50-cell stacks (15 kWh) was produced and delivered to Sandia National Laboratories (SNL) for testing. The most critical development was the ability to assemble a battery stack that remained leak free. The

  16. Load regulating expansion fixture

    DOEpatents

    Wagner, Lawrence M.; Strum, Michael J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components.

  17. Load regulating expansion fixture

    DOEpatents

    Wagner, L.M.; Strum, M.J.

    1998-12-15

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located therebetween. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig.

  18. Load sensing system

    DOEpatents

    Sohns, C.W.; Nodine, R.N.; Wallace, S.A.

    1999-05-04

    A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast inventories of stored nuclear material can be continuously monitored and inventoried of minimal cost. 4 figs.

  19. Modelling Continuing Load at Disaggregated Levels

    ERIC Educational Resources Information Center

    Seidel, Ewa

    2014-01-01

    The current methodology of estimating load in the following year at Flinders University has achieved reasonable accuracy in the previous capped funding environment, particularly at the university level, due largely to our university having stable intakes and student profiles. While historically within reasonable limits, variation in estimates at…

  20. Fruit load governs transpiration of olive trees.

    PubMed

    Bustan, Amnon; Dag, Arnon; Yermiyahu, Uri; Erel, Ran; Presnov, Eugene; Agam, Nurit; Kool, Dilia; Iwema, Joost; Zipori, Isaac; Ben-Gal, Alon

    2016-03-01

    We tested the hypothesis that whole-tree water consumption of olives (Olea europaea L.) is fruit load-dependent and investigated the driving physiological mechanisms. Fruit load was manipulated in mature olives grown in weighing-drainage lysimeters. Fruit was thinned or entirely removed from trees at three separate stages of growth: early, mid and late in the season. Tree-scale transpiration, calculated from lysimeter water balance, was found to be a function of fruit load, canopy size and weather conditions. Fruit removal caused an immediate decline in water consumption, measured as whole-plant transpiration normalized to tree size, which persisted until the end of the season. The later the execution of fruit removal, the greater was the response. The amount of water transpired by a fruit-loaded tree was found to be roughly 30% greater than that of an equivalent low- or nonyielding tree. The tree-scale response to fruit was reflected in stem water potential but was not mirrored in leaf-scale physiological measurements of stomatal conductance or photosynthesis. Trees with low or no fruit load had higher vegetative growth rates. However, no significant difference was observed in the overall aboveground dry biomass among groups, when fruit was included. This case, where carbon sources and sinks were both not limiting, suggests that the role of fruit on water consumption involves signaling and alterations in hydraulic properties of vascular tissues and tree organs.