Science.gov

Sample records for stochastic ad allocation

  1. Stochastic optimisation of water allocation on a global scale

    NASA Astrophysics Data System (ADS)

    Schmitz, Oliver; Straatsma, Menno; Karssenberg, Derek; Bierkens, Marc F. P.

    2014-05-01

    Climate change, increasing population and further economic developments are expected to increase water scarcity for many regions of the world. Optimal water management strategies are required to minimise the water gap between water supply and domestic, industrial and agricultural water demand. A crucial aspect of water allocation is the spatial scale of optimisation. Blue water supply peaks at the upstream parts of large catchments, whereas demands are often largest at the industrialised downstream parts. Two extremes exist in water allocation: (i) 'First come, first serve,' which allows the upstream water demands to be fulfilled without considerations of downstream demands, and (ii) 'All for one, one for all' that satisfies water allocation over the whole catchment. In practice, water treaties govern intermediate solutions. The objective of this study is to determine the effect of these two end members on water allocation optimisation with respect to water scarcity. We conduct this study on a global scale with the year 2100 as temporal horizon. Water supply is calculated using the hydrological model PCR-GLOBWB, operating at a 5 arcminutes resolution and a daily time step. PCR-GLOBWB is forced with temperature and precipitation fields from the Hadgem2-ES global circulation model that participated in the latest coupled model intercomparison project (CMIP5). Water demands are calculated for representative concentration pathway 6.0 (RCP 6.0) and shared socio-economic pathway scenario 2 (SSP2). To enable the fast computation of the optimisation, we developed a hydrologically correct network of 1800 basin segments with an average size of 100 000 square kilometres. The maximum number of nodes in a network was 140 for the Amazon Basin. Water demands and supplies are aggregated to cubic kilometres per month per segment. A new open source implementation of the water allocation is developed for the stochastic optimisation of the water allocation. We apply a Genetic Algorithm

  2. Stochastic does not equal ad hoc. [theories of lunar origin

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1984-01-01

    Some classes of influential events in solar system history are class-predictable but not event-predictable. Theories of lunar origin should not ignore class-predictable stochastic events. Impacts and close encounters with large objects during planet formation are class-predictable. These stochastic events, such as large impacts that triggered ejection of Earth-mantle material into a circum-Earth cloud, should not be rejected as ad hoc. A way to deal with such events scientifically is to investigate their consequences; if it can be shown that they might produce the Moon, they become viable concepts in theories of lunar origin.

  3. A stochasticity threshold in holography and the instability of AdS

    NASA Astrophysics Data System (ADS)

    Basu, Pallab; Krishnan, Chethan; Saurabh, Ayush

    2015-07-01

    We give strong numerical evidence that a self-interacting probe scalar field in AdS, with only a few modes turned on initially, will undergo fast thermalization only if it is above a certain energetic threshold. Below the threshold the energy stays close to constant in a few modes for a very long time instead of cascading quickly. This indicates the existence of a Strong Stochasticity Threshold (SST) in holography. The idea of SST is familiar from certain statistical mechanical systems, and we suggest that it exists also in AdS gravity. This would naturally reconcile the generic nonlinear instability of AdS observed by Bizon and Rostworowski, with the Fermi-Pasta-Ulam-Tsingou-like quasiperiodicity noticed recently for some classes of initial conditions. We show that our simple setup captures many of the relevant features of the full gravity-scalar system.

  4. Inexact rough-interval two-stage stochastic programming for conjunctive water allocation problems.

    PubMed

    Lu, Hongwei; Huang, Guohe; He, Li

    2009-10-01

    An inexact rough-interval two-stage stochastic programming (IRTSP) method is developed for conjunctive water allocation problems. Rough intervals (RIs), as a particular case of rough sets, are introduced into the modeling framework to tackle dual-layer information provided by decision makers. Through embeding upper and lower approximation intervals, rough intervals are capable of reflecting complex parameters with the most reliable and possible variation ranges being identified. An interactive solution method is also derived. A conjunctive water-allocation system is then structured for characterizing the proposed model. Solutions indicate a detailed optimal allocation scheme with a rough-interval form; a total of [[1048.83, 2078.29]:[1482.26, 2020.60

  5. Parameter allocation of parallel array bistable stochastic resonance and its application in communication systems

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Wang, You-Guo; Zhai, Qi-Qing; Liu, Jin

    2016-10-01

    In this paper, we propose a parameter allocation scheme in a parallel array bistable stochastic resonance-based communication system (P-BSR-CS) to improve the performance of weak binary pulse amplitude modulated (BPAM) signal transmissions. The optimal parameter allocation policy of the P-BSR-CS is provided to minimize the bit error rate (BER) and maximize the channel capacity (CC) under the adiabatic approximation condition. On this basis, we further derive the best parameter selection theorem in realistic communication scenarios via variable transformation. Specifically, the P-BSR structure design not only brings the robustness of parameter selection optimization, where the optimal parameter pair is not fixed but variable in quite a wide range, but also produces outstanding system performance. Theoretical analysis and simulation results indicate that in the P-BSR-CS the proposed parameter allocation scheme yields considerable performance improvement, particularly in very low signal-to-noise ratio (SNR) environments. Project supported by the National Natural Science Foundation of China (Grant No. 61179027), the Qinglan Project of Jiangsu Province of China (Grant No. QL06212006), and the University Postgraduate Research and Innovation Project of Jiangsu Province (Grant Nos. KYLX15_0829, KYLX15_0831).

  6. Dynamic fair node spectrum allocation for ad hoc networks using random matrices

    NASA Astrophysics Data System (ADS)

    Rahmes, Mark; Lemieux, George; Chester, Dave; Sonnenberg, Jerry

    2015-05-01

    Dynamic Spectrum Access (DSA) is widely seen as a solution to the problem of limited spectrum, because of its ability to adapt the operating frequency of a radio. Mobile Ad Hoc Networks (MANETs) can extend high-capacity mobile communications over large areas where fixed and tethered-mobile systems are not available. In one use case with high potential impact, cognitive radio employs spectrum sensing to facilitate the identification of allocated frequencies not currently accessed by their primary users. Primary users own the rights to radiate at a specific frequency and geographic location, while secondary users opportunistically attempt to radiate at a specific frequency when the primary user is not using it. We populate a spatial radio environment map (REM) database with known information that can be leveraged in an ad hoc network to facilitate fair path use of the DSA-discovered links. Utilization of high-resolution geospatial data layers in RF propagation analysis is directly applicable. Random matrix theory (RMT) is useful in simulating network layer usage in nodes by a Wishart adjacency matrix. We use the Dijkstra algorithm for discovering ad hoc network node connection patterns. We present a method for analysts to dynamically allocate node-node path and link resources using fair division. User allocation of limited resources as a function of time must be dynamic and based on system fairness policies. The context of fair means that first available request for an asset is not envied as long as it is not yet allocated or tasked in order to prevent cycling of the system. This solution may also save money by offering a Pareto efficient repeatable process. We use a water fill queue algorithm to include Shapley value marginal contributions for allocation.

  7. Development of a Computational Framework for Stochastic Co-optimization of Water and Energy Resource Allocations under Climatic Uncertainty

    NASA Astrophysics Data System (ADS)

    Xuan, Y.; Mahinthakumar, K.; Arumugam, S.; DeCarolis, J.

    2015-12-01

    Owing to the lack of a consistent approach to assimilate probabilistic forecasts for water and energy systems, utilization of climate forecasts for conjunctive management of these two systems is very limited. Prognostic management of these two systems presents a stochastic co-optimization problem that seeks to determine reservoir releases and power allocation strategies while minimizing the expected operational costs subject to probabilistic climate forecast constraints. To address these issues, we propose a high performance computing (HPC) enabled computational framework for stochastic co-optimization of water and energy resource allocations under climate uncertainty. The computational framework embodies a new paradigm shift in which attributes of climate (e.g., precipitation, temperature) and its forecasted probability distribution are employed conjointly to inform seasonal water availability and electricity demand. The HPC enabled cyberinfrastructure framework is developed to perform detailed stochastic analyses, and to better quantify and reduce the uncertainties associated with water and power systems management by utilizing improved hydro-climatic forecasts. In this presentation, our stochastic multi-objective solver extended from Optimus (Optimization Methods for Universal Simulators), is introduced. The solver uses parallel cooperative multi-swarm method to solve for efficient solution of large-scale simulation-optimization problems on parallel supercomputers. The cyberinfrastructure harnesses HPC resources to perform intensive computations using ensemble forecast models of streamflow and power demand. The stochastic multi-objective particle swarm optimizer we developed is used to co-optimize water and power system models under constraints over a large number of ensembles. The framework sheds light on the application of climate forecasts and cyber-innovation framework to improve management and promote the sustainability of water and energy systems.

  8. Examination-Related Anxiety in Students Diagnosed with AD/HD and the Case for an Allocation of Extra Time: Perspectives of Teachers, Mothers and Students

    ERIC Educational Resources Information Center

    Taylor, Myra; Houghton, Stephen

    2008-01-01

    This study details the perspectives of Western Australian teachers, students and mothers on the case for an allocation of extra exam time to students diagnosed with Attention-Deficit/Hyperactivity Disorder (AD/HD). Eighteen teachers of students with AD/HD (14 high and four primary), 15 students with AD/HD (10 high and 5 primary), and their mothers…

  9. Optimizing Real-Time Vaccine Allocation in a Stochastic SIR Model

    PubMed Central

    Nguyen, Chantal; Carlson, Jean M.

    2016-01-01

    Real-time vaccination following an outbreak can effectively mitigate the damage caused by an infectious disease. However, in many cases, available resources are insufficient to vaccinate the entire at-risk population, logistics result in delayed vaccine deployment, and the interaction between members of different cities facilitates a wide spatial spread of infection. Limited vaccine, time delays, and interaction (or coupling) of cities lead to tradeoffs that impact the overall magnitude of the epidemic. These tradeoffs mandate investigation of optimal strategies that minimize the severity of the epidemic by prioritizing allocation of vaccine to specific subpopulations. We use an SIR model to describe the disease dynamics of an epidemic which breaks out in one city and spreads to another. We solve a master equation to determine the resulting probability distribution of the final epidemic size. We then identify tradeoffs between vaccine, time delay, and coupling, and we determine the optimal vaccination protocols resulting from these tradeoffs. PMID:27043931

  10. Introducing health gains in location-allocation models: A stochastic model for planning the delivery of long-term care

    NASA Astrophysics Data System (ADS)

    Cardoso, T.; Oliveira, M. D.; Barbosa-Póvoa, A.; Nickel, S.

    2015-05-01

    Although the maximization of health is a key objective in health care systems, location-allocation literature has not yet considered this dimension. This study proposes a multi-objective stochastic mathematical programming approach to support the planning of a multi-service network of long-term care (LTC), both in terms of services location and capacity planning. This approach is based on a mixed integer linear programming model with two objectives - the maximization of expected health gains and the minimization of expected costs - with satisficing levels in several dimensions of equity - namely, equity of access, equity of utilization, socioeconomic equity and geographical equity - being imposed as constraints. The augmented ε-constraint method is used to explore the trade-off between these conflicting objectives, with uncertainty in the demand and delivery of care being accounted for. The model is applied to analyze the (re)organization of the LTC network currently operating in the Great Lisbon region in Portugal for the 2014-2016 period. Results show that extending the network of LTC is a cost-effective investment.

  11. Implementation of equity in resource allocation for regional earthquake risk mitigation using two-stage stochastic programming.

    PubMed

    Zolfaghari, Mohammad R; Peyghaleh, Elnaz

    2015-03-01

    This article presents a new methodology to implement the concept of equity in regional earthquake risk mitigation programs using an optimization framework. It presents a framework that could be used by decisionmakers (government and authorities) to structure budget allocation strategy toward different seismic risk mitigation measures, i.e., structural retrofitting for different building structural types in different locations and planning horizons. A two-stage stochastic model is developed here to seek optimal mitigation measures based on minimizing mitigation expenditures, reconstruction expenditures, and especially large losses in highly seismically active countries. To consider fairness in the distribution of financial resources among different groups of people, the equity concept is incorporated using constraints in model formulation. These constraints limit inequity to the user-defined level to achieve the equity-efficiency tradeoff in the decision-making process. To present practical application of the proposed model, it is applied to a pilot area in Tehran, the capital city of Iran. Building stocks, structural vulnerability functions, and regional seismic hazard characteristics are incorporated to compile a probabilistic seismic risk model for the pilot area. Results illustrate the variation of mitigation expenditures by location and structural type for buildings. These expenditures are sensitive to the amount of available budget and equity consideration for the constant risk aversion. Most significantly, equity is more easily achieved if the budget is unlimited. Conversely, increasing equity where the budget is limited decreases the efficiency. The risk-return tradeoff, equity-reconstruction expenditures tradeoff, and variation of per-capita expected earthquake loss in different income classes are also presented.

  12. Investigation and incorporation of water inflow uncertainties through stochastic modelling in a combined optimisation methodology for water allocation in Alfeios River (Greece)

    NASA Astrophysics Data System (ADS)

    Bekri, Eleni; Yannopoulos, Panayotis; Disse, Markus

    2014-05-01

    The Alfeios River plays a vital role for Western Peloponnisos in Greece from natural, ecological, social and economic aspect. The main river and its six tributaries, forming the longest watercourse and the highest streamflow rate of Peloponnisose, represent a significant source of water supply for the region, aiming at delivering and satisfying the expected demands from a variety of water users, including irrigation, drinking water supply, hydropower production and recreation. In the previous EGU General Assembly, a fuzzy-boundary-interval linear programming methodology, based on Li et al. (2010) and Bekri et al. (2012), has been presented for optimal water allocation under uncertain and vague system conditions in the Alfeios River Basin. Uncertainties associated with the benefit and cost coefficient in the objective function of the main water uses (hydropower production and irrigation) were expressed as probability distributions and fuzzy boundary intervals derived by associated α-cut levels. The uncertainty of the monthly water inflows was not incorporated in the previous initial application and the analysis of all other sources of uncertainty has been applied to two extreme hydrologic years represented by a selected wet and dry year. To manage and operate the river system, decision makers should be able to analyze and evaluate the impact of various hydrologic scenarios. In the present work, the critical uncertain parameter of water inflows is analyzed and its incorporation as an additional type of uncertainty in the suggested methodology is investigated, in order to enable the assessment of optimal water allocation for hydrologic and socio-economic scenarios based both on historical data and projected climate change conditions. For this purpose, stochastic simulation analysis for a part of the Alfeios river system is undertaken, testing various stochastic models from simple stationary ones (AR and ARMA), Thomas-Fiering, ARIMA as well as more sophisticated and

  13. Resource Allocation.

    ERIC Educational Resources Information Center

    Stennett, R. G.

    A research allocation formula employed in London, Ontario elementary schools, as well as supporting data on the method, are provided in this report. Attempts to improve on the traditional methods of resource allocation in London's schools were based on two principles: (1) that need for a particular service could and should be determined…

  14. Stochastic games

    PubMed Central

    Solan, Eilon; Vieille, Nicolas

    2015-01-01

    In 1953, Lloyd Shapley contributed his paper “Stochastic games” to PNAS. In this paper, he defined the model of stochastic games, which were the first general dynamic model of a game to be defined, and proved that it admits a stationary equilibrium. In this Perspective, we summarize the historical context and the impact of Shapley’s contribution. PMID:26556883

  15. Stochastic resonance

    NASA Astrophysics Data System (ADS)

    Gammaitoni, Luca; Hänggi, Peter; Jung, Peter; Marchesoni, Fabio

    1998-01-01

    Over the last two decades, stochastic resonance has continuously attracted considerable attention. The term is given to a phenomenon that is manifest in nonlinear systems whereby generally feeble input information (such as a weak signal) can be be amplified and optimized by the assistance of noise. The effect requires three basic ingredients: (i) an energetic activation barrier or, more generally, a form of threshold; (ii) a weak coherent input (such as a periodic signal); (iii) a source of noise that is inherent in the system, or that adds to the coherent input. Given these features, the response of the system undergoes resonance-like behavior as a function of the noise level; hence the name stochastic resonance. The underlying mechanism is fairly simple and robust. As a consequence, stochastic resonance has been observed in a large variety of systems, including bistable ring lasers, semiconductor devices, chemical reactions, and mechanoreceptor cells in the tail fan of a crayfish. In this paper, the authors report, interpret, and extend much of the current understanding of the theory and physics of stochastic resonance. They introduce the readers to the basic features of stochastic resonance and its recent history. Definitions of the characteristic quantities that are important to quantify stochastic resonance, together with the most important tools necessary to actually compute those quantities, are presented. The essence of classical stochastic resonance theory is presented, and important applications of stochastic resonance in nonlinear optics, solid state devices, and neurophysiology are described and put into context with stochastic resonance theory. More elaborate and recent developments of stochastic resonance theory are discussed, ranging from fundamental quantum properties-being important at low temperatures-over spatiotemporal aspects in spatially distributed systems, to realizations in chaotic maps. In conclusion the authors summarize the achievements

  16. Stochastic thermodynamics

    NASA Astrophysics Data System (ADS)

    Eichhorn, Ralf; Aurell, Erik

    2014-04-01

    'Stochastic thermodynamics as a conceptual framework combines the stochastic energetics approach introduced a decade ago by Sekimoto [1] with the idea that entropy can consistently be assigned to a single fluctuating trajectory [2]'. This quote, taken from Udo Seifert's [3] 2008 review, nicely summarizes the basic ideas behind stochastic thermodynamics: for small systems, driven by external forces and in contact with a heat bath at a well-defined temperature, stochastic energetics [4] defines the exchanged work and heat along a single fluctuating trajectory and connects them to changes in the internal (system) energy by an energy balance analogous to the first law of thermodynamics. Additionally, providing a consistent definition of trajectory-wise entropy production gives rise to second-law-like relations and forms the basis for a 'stochastic thermodynamics' along individual fluctuating trajectories. In order to construct meaningful concepts of work, heat and entropy production for single trajectories, their definitions are based on the stochastic equations of motion modeling the physical system of interest. Because of this, they are valid even for systems that are prevented from equilibrating with the thermal environment by external driving forces (or other sources of non-equilibrium). In that way, the central notions of equilibrium thermodynamics, such as heat, work and entropy, are consistently extended to the non-equilibrium realm. In the (non-equilibrium) ensemble, the trajectory-wise quantities acquire distributions. General statements derived within stochastic thermodynamics typically refer to properties of these distributions, and are valid in the non-equilibrium regime even beyond the linear response. The extension of statistical mechanics and of exact thermodynamic statements to the non-equilibrium realm has been discussed from the early days of statistical mechanics more than 100 years ago. This debate culminated in the development of linear response

  17. Making sense of peak load cost allocations

    SciTech Connect

    Power, T.M.

    1995-03-15

    When it comes to cost allocation, common wisdom assigns costs in proportion to class contributions to peak loads, The justification is simple: Since the equipment had to be sized to meet peak day loads, those costs should be allocated on the same basis. Many different peak allocators have been developed on this assumption: single coincident peak contribution, sum of coincident peaks, noncoincident peak, average and excess demand, peak and average demand, base and extra capacity, and so on. Such pure peak-load allocators may not be politically acceptable, but conceptually, at least, they appear to offer the only defensible approach. Nevertheless, where capacity can be added with significant economies of scale, making cost allocations in proportion to peak loads violates well-known relationships between economics and engineering. What is missing is any tracing of the way in which the peak-load design criteria actually influence the cost incurred.

  18. Computer Processor Allocator

    2004-03-01

    The Compute Processor Allocator (CPA) provides an efficient and reliable mechanism for managing and allotting processors in a massively parallel (MP) computer. It maintains information in a database on the health. configuration and allocation of each processor. This persistent information is factored in to each allocation decision. The CPA runs in a distributed fashion to avoid a single point of failure.

  19. Hairy AdS solitons

    NASA Astrophysics Data System (ADS)

    Anabalón, Andrés; Astefanesei, Dumitru; Choque, David

    2016-11-01

    We construct exact hairy AdS soliton solutions in Einstein-dilaton gravity theory. We examine their thermodynamic properties and discuss the role of these solutions for the existence of first order phase transitions for hairy black holes. The negative energy density associated to hairy AdS solitons can be interpreted as the Casimir energy that is generated in the dual filed theory when the fermions are antiperiodic on the compact coordinate.

  20. Latent IBP Compound Dirichlet Allocation.

    PubMed

    Archambeau, Cedric; Lakshminarayanan, Balaji; Bouchard, Guillaume

    2015-02-01

    We introduce the four-parameter IBP compound Dirichlet process (ICDP), a stochastic process that generates sparse non-negative vectors with potentially an unbounded number of entries. If we repeatedly sample from the ICDP we can generate sparse matrices with an infinite number of columns and power-law characteristics. We apply the four-parameter ICDP to sparse nonparametric topic modelling to account for the very large number of topics present in large text corpora and the power-law distribution of the vocabulary of natural languages. The model, which we call latent IBP compound Dirichlet allocation (LIDA), allows for power-law distributions, both, in the number of topics summarising the documents and in the number of words defining each topic. It can be interpreted as a sparse variant of the hierarchical Pitman-Yor process when applied to topic modelling. We derive an efficient and simple collapsed Gibbs sampler closely related to the collapsed Gibbs sampler of latent Dirichlet allocation (LDA), making the model applicable in a wide range of domains. Our nonparametric Bayesian topic model compares favourably to the widely used hierarchical Dirichlet process and its heavy tailed version, the hierarchical Pitman-Yor process, on benchmark corpora. Experiments demonstrate that accounting for the power-distribution of real data is beneficial and that sparsity provides more interpretable results. PMID:26353244

  1. Stochastic Cooling

    SciTech Connect

    Blaskiewicz, M.

    2011-01-01

    Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

  2. Immigration-extinction dynamics of stochastic populations

    NASA Astrophysics Data System (ADS)

    Meerson, Baruch; Ovaskainen, Otso

    2013-07-01

    How high should be the rate of immigration into a stochastic population in order to significantly reduce the probability of observing the population become extinct? Is there any relation between the population size distributions with and without immigration? Under what conditions can one justify the simple patch occupancy models, which ignore the population distribution and its dynamics in a patch, and treat a patch simply as either occupied or empty? We answer these questions by exactly solving a simple stochastic model obtained by adding a steady immigration to a variant of the Verhulst model: a prototypical model of an isolated stochastic population.

  3. Value Added?

    ERIC Educational Resources Information Center

    UCLA IDEA, 2012

    2012-01-01

    Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…

  4. Stochastic cooling in RHIC

    SciTech Connect

    Brennan,J.M.; Blaskiewicz, M. M.; Severino, F.

    2009-05-04

    After the success of longitudinal stochastic cooling of bunched heavy ion beam in RHIC, transverse stochastic cooling in the vertical plane of Yellow ring was installed and is being commissioned with proton beam. This report presents the status of the effort and gives an estimate, based on simulation, of the RHIC luminosity with stochastic cooling in all planes.

  5. Stochastic differential equations

    SciTech Connect

    Sobczyk, K. )

    1990-01-01

    This book provides a unified treatment of both regular (or random) and Ito stochastic differential equations. It focuses on solution methods, including some developed only recently. Applications are discussed, in particular an insight is given into both the mathematical structure, and the most efficient solution methods (analytical as well as numerical). Starting from basic notions and results of the theory of stochastic processes and stochastic calculus (including Ito's stochastic integral), many principal mathematical problems and results related to stochastic differential equations are expounded here for the first time. Applications treated include those relating to road vehicles, earthquake excitations and offshore structures.

  6. The Unobtrusive Memory Allocator

    2003-03-31

    This library implements a memory allocator/manager which ask its host program or library for memory refions to manage rather than requesting them from the operating system. This allocator supports multiple distinct heaps within a single executable, each of which may grow either upward or downward in memory. The GNU mmalloc library has been modified in such a way that its allocation algorithms have been preserved, but the manner in which it obtains regions to managemore » has been changed to request memory from the host program or library. Additional modifications allow the allocator to manage each heap as either upward or downward-growing. By allowing the hosting program or library to determine what memory is managed, this package allows a greater degree of control than other memory allocation/management libraries. Additional distinguishing features include the ability to manage multiple distinct heaps with in a single executable, each of which may grow either upward or downward in memory. The most common use of this library is in conjunction with the Berkeley Unified Parallel C (UPC) Runtime Library. This package is a modified version of the LGPL-licensed "mmalloc" allocator from release 5.2 of the "gdb" debugger's source code.« less

  7. DIS in AdS

    SciTech Connect

    Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios

    2009-03-23

    We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.

  8. Fluctuations as stochastic deformation

    NASA Astrophysics Data System (ADS)

    Kazinski, P. O.

    2008-04-01

    A notion of stochastic deformation is introduced and the corresponding algebraic deformation procedure is developed. This procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). This method is demonstrated on diverse relativistic and nonrelativistic models with finite and infinite degrees of freedom. It is shown that under stochastic deformation the model of a nonrelativistic particle interacting with the electromagnetic field on a curved background passes into the stochastic model described by the Fokker-Planck equation with the diffusion tensor being the inverse metric tensor. The first stochastic correction to the Newton equations for this system is found. The Klein-Kramers equation is also derived as the stochastic deformation of a certain classical model. Relativistic generalizations of the Fokker-Planck and Klein-Kramers equations are obtained by applying the procedure of stochastic deformation to appropriate relativistic classical models. The analog of the Fokker-Planck equation associated with the stochastic Lorentz-Dirac equation is derived too. The stochastic deformation of the models of a free scalar field and an electromagnetic field is investigated. It turns out that in the latter case the obtained stochastic model describes a fluctuating electromagnetic field in a transparent medium.

  9. Fluctuations as stochastic deformation.

    PubMed

    Kazinski, P O

    2008-04-01

    A notion of stochastic deformation is introduced and the corresponding algebraic deformation procedure is developed. This procedure is analogous to the deformation of an algebra of observables like deformation quantization, but for an imaginary deformation parameter (the Planck constant). This method is demonstrated on diverse relativistic and nonrelativistic models with finite and infinite degrees of freedom. It is shown that under stochastic deformation the model of a nonrelativistic particle interacting with the electromagnetic field on a curved background passes into the stochastic model described by the Fokker-Planck equation with the diffusion tensor being the inverse metric tensor. The first stochastic correction to the Newton equations for this system is found. The Klein-Kramers equation is also derived as the stochastic deformation of a certain classical model. Relativistic generalizations of the Fokker-Planck and Klein-Kramers equations are obtained by applying the procedure of stochastic deformation to appropriate relativistic classical models. The analog of the Fokker-Planck equation associated with the stochastic Lorentz-Dirac equation is derived too. The stochastic deformation of the models of a free scalar field and an electromagnetic field is investigated. It turns out that in the latter case the obtained stochastic model describes a fluctuating electromagnetic field in a transparent medium.

  10. Detecting non-binomial sex allocation when developmental mortality operates.

    PubMed

    Wilkinson, Richard D; Kapranas, Apostolos; Hardy, Ian C W

    2016-11-01

    Optimal sex allocation theory is one of the most intricately developed areas of evolutionary ecology. Under a range of conditions, particularly under population sub-division, selection favours sex being allocated to offspring non-randomly, generating non-binomial variances of offspring group sex ratios. Detecting non-binomial sex allocation is complicated by stochastic developmental mortality, as offspring sex can often only be identified on maturity with the sex of non-maturing offspring remaining unknown. We show that current approaches for detecting non-binomiality have limited ability to detect non-binomial sex allocation when developmental mortality has occurred. We present a new procedure using an explicit model of sex allocation and mortality and develop a Bayesian model selection approach (available as an R package). We use the double and multiplicative binomial distributions to model over- and under-dispersed sex allocation and show how to calculate Bayes factors for comparing these alternative models to the null hypothesis of binomial sex allocation. The ability to detect non-binomial sex allocation is greatly increased, particularly in cases where mortality is common. The use of Bayesian methods allows for the quantification of the evidence in favour of each hypothesis, and our modelling approach provides an improved descriptive capability over existing approaches. We use a simulation study to demonstrate substantial improvements in power for detecting non-binomial sex allocation in situations where current methods fail, and we illustrate the approach in real scenarios using empirically obtained datasets on the sexual composition of groups of gregarious parasitoid wasps.

  11. A Framework for Optimal Control Allocation with Structural Load Constraints

    NASA Technical Reports Server (NTRS)

    Frost, Susan A.; Taylor, Brian R.; Jutte, Christine V.; Burken, John J.; Trinh, Khanh V.; Bodson, Marc

    2010-01-01

    Conventional aircraft generally employ mixing algorithms or lookup tables to determine control surface deflections needed to achieve moments commanded by the flight control system. Control allocation is the problem of converting desired moments into control effector commands. Next generation aircraft may have many multipurpose, redundant control surfaces, adding considerable complexity to the control allocation problem. These issues can be addressed with optimal control allocation. Most optimal control allocation algorithms have control surface position and rate constraints. However, these constraints are insufficient to ensure that the aircraft's structural load limits will not be exceeded by commanded surface deflections. In this paper, a framework is proposed to enable a flight control system with optimal control allocation to incorporate real-time structural load feedback and structural load constraints. A proof of concept simulation that demonstrates the framework in a simulation of a generic transport aircraft is presented.

  12. Approaches to Resource Allocation

    ERIC Educational Resources Information Center

    Dressel, Paul; Simon, Lou Anna Kimsey

    1976-01-01

    Various budgeting patterns and strategies are currently in use, each with its own particular strengths and weaknesses. Neither cost-benefit analysis nor cost-effectiveness analysis offers any better solution to the allocation problem than do the unsupported contentions of departments or the historical unit costs. An operable model that performs…

  13. Stochastic Convection Parameterizations

    NASA Technical Reports Server (NTRS)

    Teixeira, Joao; Reynolds, Carolyn; Suselj, Kay; Matheou, Georgios

    2012-01-01

    computational fluid dynamics, radiation, clouds, turbulence, convection, gravity waves, surface interaction, radiation interaction, cloud and aerosol microphysics, complexity (vegetation, biogeochemistry, radiation versus turbulence/convection stochastic approach, non-linearities, Monte Carlo, high resolutions, large-Eddy Simulations, cloud structure, plumes, saturation in tropics, forecasting, parameterizations, stochastic, radiation-clod interaction, hurricane forecasts

  14. A Stochastic Employment Problem

    ERIC Educational Resources Information Center

    Wu, Teng

    2013-01-01

    The Stochastic Employment Problem(SEP) is a variation of the Stochastic Assignment Problem which analyzes the scenario that one assigns balls into boxes. Balls arrive sequentially with each one having a binary vector X = (X[subscript 1], X[subscript 2],...,X[subscript n]) attached, with the interpretation being that if X[subscript i] = 1 the ball…

  15. Stochastic volatility models and Kelvin waves

    NASA Astrophysics Data System (ADS)

    Lipton, Alex; Sepp, Artur

    2008-08-01

    We use stochastic volatility models to describe the evolution of an asset price, its instantaneous volatility and its realized volatility. In particular, we concentrate on the Stein and Stein model (SSM) (1991) for the stochastic asset volatility and the Heston model (HM) (1993) for the stochastic asset variance. By construction, the volatility is not sign definite in SSM and is non-negative in HM. It is well known that both models produce closed-form expressions for the prices of vanilla option via the Lewis-Lipton formula. However, the numerical pricing of exotic options by means of the finite difference and Monte Carlo methods is much more complex for HM than for SSM. Until now, this complexity was considered to be an acceptable price to pay for ensuring that the asset volatility is non-negative. We argue that having negative stochastic volatility is a psychological rather than financial or mathematical problem, and advocate using SSM rather than HM in most applications. We extend SSM by adding volatility jumps and obtain a closed-form expression for the density of the asset price and its realized volatility. We also show that the current method of choice for solving pricing problems with stochastic volatility (via the affine ansatz for the Fourier-transformed density function) can be traced back to the Kelvin method designed in the 19th century for studying wave motion problems arising in fluid dynamics.

  16. Myrmics Memory Allocator

    SciTech Connect

    Lymperis, S.

    2011-09-23

    MMA is a stand-alone memory management system for MPI clusters. It implements a shared Partitioned Global Address Space, where multiple MPI processes request objects from the allocator and the latter provides them with system-wide unique memory addresses for each object. It provides applications with an intuitive way of managing the memory system in a unified way, thus enabling easier writing of irregular application code.

  17. Synaptic Tagging During Memory Allocation

    PubMed Central

    Rogerson, Thomas; Cai, Denise; Frank, Adam; Sano, Yoshitake; Shobe, Justin; Aranda, Manuel L.; Silva, Alcino J.

    2014-01-01

    There is now compelling evidence that the allocation of memory to specific neurons (neuronal allocation) and synapses (synaptic allocation) in a neurocircuit is not random and that instead specific mechanisms, such as increases in neuronal excitability and synaptic tagging and capture, determine the exact sites where memories are stored. We propose an integrated view of these processes, such that neuronal allocation, synaptic tagging and capture, spine clustering and metaplasticity reflect related aspects of memory allocation mechanisms. Importantly, the properties of these mechanisms suggest a set of rules that profoundly affect how memories are stored and recalled. PMID:24496410

  18. 50 CFR 660.323 - Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Pacific whiting allocations, allocation attainment, and inseason allocation reapportionment. 660.323 Section 660.323 Wildlife and Fisheries FISHERY...) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries § 660.323 Pacific whiting...

  19. Quantum Stochastic Processes

    SciTech Connect

    Spring, William Joseph

    2009-04-13

    We consider quantum analogues of n-parameter stochastic processes, associated integrals and martingale properties extending classical results obtained in [1, 2, 3], and quantum results in [4, 5, 6, 7, 8, 9, 10].

  20. Dynamics of Double Stochastic Operators

    NASA Astrophysics Data System (ADS)

    Saburov, Mansoor

    2016-03-01

    A double stochastic operator is a generalization of a double stochastic matrix. In this paper, we study the dynamics of double stochastic operators. We give a criterion for a regularity of a double stochastic operator in terms of absences of its periodic points. We provide some examples to insure that, in general, a trajectory of a double stochastic operator may converge to any interior point of the simplex.

  1. Didactic discussion of stochastic resonance effects and weak signals

    SciTech Connect

    Adair, R.K.

    1996-12-01

    A simple, paradigmatic, model is used to illustrate some general properties of effects subsumed under the label stochastic resonance. In particular, analyses of the transparent model show that (1) a small amount of noise added to a much larger signal can greatly increase the response to the signal, but (2) a weak signal added to much larger noise will not generate a substantial added response. The conclusions drawn from the model illustrate the general result that stochastic resonance effects do not provide an avenue for signals that are much smaller than noise to affect biology. A further analysis demonstrates the effects of small signals in the shifting of biologically important chemical equilibria under conditions where stochastic resonance effects are significant.

  2. [Organ allocation. Ethical issues].

    PubMed

    Cattorini, P

    2010-01-01

    The criteria for allocating organs are one of the most debated ethical issue in the transplantation programs. The article examines some rules and principles followed by "Nord Italia Transplant program", summarized in its Principles' Charter and explained in a recent interdisciplinary book. General theories of justice and their application to individual clinical cases are commented and evaluated, in order to foster a public, democratic, transparent debate among professionals and citizens, scientific associations and customers' organizations. Some specific moral dilemmas are focused regarding the concepts of proportionate treatment, unselfish donation by living persons, promotion of local institutions efficiency. PMID:20677677

  3. Allocations for HANDI 2000 business management system

    SciTech Connect

    Wilson, D.

    1998-08-24

    The Data Integration 2000 Project will result in an integrated and comprehensive set of functional applications containing core information necessary to support the Project Hanford Management Contract. It is based on the Commercial-Off-The-Shelf product solution with commercially proven business processes. The COTS product solution set, of PassPort and People Soft software, supports finance, supply and chemical management/Material Safety Data Sheet, human resources. Allocations at Fluor Daniel Hanford are burdens added to base costs using a predetermined rate.

  4. Computationally efficient control allocation

    NASA Technical Reports Server (NTRS)

    Durham, Wayne (Inventor)

    2001-01-01

    A computationally efficient method for calculating near-optimal solutions to the three-objective, linear control allocation problem is disclosed. The control allocation problem is that of distributing the effort of redundant control effectors to achieve some desired set of objectives. The problem is deemed linear if control effectiveness is affine with respect to the individual control effectors. The optimal solution is that which exploits the collective maximum capability of the effectors within their individual physical limits. Computational efficiency is measured by the number of floating-point operations required for solution. The method presented returned optimal solutions in more than 90% of the cases examined; non-optimal solutions returned by the method were typically much less than 1% different from optimal and the errors tended to become smaller than 0.01% as the number of controls was increased. The magnitude of the errors returned by the present method was much smaller than those that resulted from either pseudo inverse or cascaded generalized inverse solutions. The computational complexity of the method presented varied linearly with increasing numbers of controls; the number of required floating point operations increased from 5.5 i, to seven times faster than did the minimum-norm solution (the pseudoinverse), and at about the same rate as did the cascaded generalized inverse solution. The computational requirements of the method presented were much better than that of previously described facet-searching methods which increase in proportion to the square of the number of controls.

  5. Generalized multidimensional dynamic allocation method.

    PubMed

    Lebowitsch, Jonathan; Ge, Yan; Young, Benjamin; Hu, Feifang

    2012-12-10

    Dynamic allocation has received considerable attention since it was first proposed in the 1970s as an alternative means of allocating treatments in clinical trials which helps to secure the balance of prognostic factors across treatment groups. The purpose of this paper is to present a generalized multidimensional dynamic allocation method that simultaneously balances treatment assignments at three key levels: within the overall study, within each level of each prognostic factor, and within each stratum, that is, combination of levels of different factors Further it offers capabilities for unbalanced and adaptive designs for trials. The treatment balancing performance of the proposed method is investigated through simulations which compare multidimensional dynamic allocation with traditional stratified block randomization and the Pocock-Simon method. On the basis of these results, we conclude that this generalized multidimensional dynamic allocation method is an improvement over conventional dynamic allocation methods and is flexible enough to be applied for most trial settings including Phases I, II and III trials.

  6. Research on allocation efficiency of the daisy chain allocation algorithm

    NASA Astrophysics Data System (ADS)

    Shi, Jingping; Zhang, Weiguo

    2013-03-01

    With the improvement of the aircraft performance in reliability, maneuverability and survivability, the number of the control effectors increases a lot. How to distribute the three-axis moments into the control surfaces reasonably becomes an important problem. Daisy chain method is simple and easy to be carried out in the design of the allocation system. But it can not solve the allocation problem for entire attainable moment subset. For the lateral-directional allocation problem, the allocation efficiency of the daisy chain can be directly measured by the area of its subset of attainable moments. Because of the non-linear allocation characteristic, the subset of attainable moments of daisy-chain method is a complex non-convex polygon, and it is difficult to solve directly. By analyzing the two-dimensional allocation problems with a "micro-element" idea, a numerical calculation algorithm is proposed to compute the area of the non-convex polygon. In order to improve the allocation efficiency of the algorithm, a genetic algorithm with the allocation efficiency chosen as the fitness function is proposed to find the best pseudo-inverse matrix.

  7. Segmented strings in AdS 3

    NASA Astrophysics Data System (ADS)

    Callebaut, Nele; Gubser, Steven S.; Samberg, Andreas; Toldo, Chiara

    2015-11-01

    We study segmented strings in flat space and in AdS 3. In flat space, these well known classical motions describe strings which at any instant of time are piecewise linear. In AdS 3, the worldsheet is composed of faces each of which is a region bounded by null geodesics in an AdS 2 subspace of AdS 3. The time evolution can be described by specifying the null geodesic motion of kinks in the string at which two segments are joined. The outcome of collisions of kinks on the worldsheet can be worked out essentially using considerations of causality. We study several examples of closed segmented strings in AdS 3 and find an unexpected quasi-periodic behavior. We also work out a WKB analysis of quantum states of yo-yo strings in AdS 5 and find a logarithmic term reminiscent of the logarithmic twist of string states on the leading Regge trajectory.

  8. Polarised black holes in AdS

    NASA Astrophysics Data System (ADS)

    Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.

    2016-06-01

    We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.

  9. On stochastic diffusion equations and stochastic Burgers' equations

    NASA Astrophysics Data System (ADS)

    Truman, A.; Zhao, H. Z.

    1996-01-01

    In this paper we construct a strong solution for the stochastic Hamilton Jacobi equation by using stochastic classical mechanics before the caustics. We thereby obtain the viscosity solution for a certain class of inviscid stochastic Burgers' equations. This viscosity solution is not continuous beyond the caustics of the corresponding Hamilton Jacobi equation. The Hopf-Cole transformation is used to identify the stochastic heat equation and the viscous stochastic Burgers' equation. The exact solutions for the above two equations are given in terms of the stochastic Hamilton Jacobi function under a no-caustic condition. We construct the heat kernel for the stochastic heat equation for zero potentials in hyperbolic space and for harmonic oscillator potentials in Euclidean space thereby obtaining the stochastic Mehler formula.

  10. Stochastically driven genetic circuits

    NASA Astrophysics Data System (ADS)

    Tsimring, L. S.; Volfson, D.; Hasty, J.

    2006-06-01

    Transcriptional regulation in small genetic circuits exhibits large stochastic fluctuations. Recent experiments have shown that a significant fraction of these fluctuations is caused by extrinsic factors. In this paper we review several theoretical and computational approaches to modeling of small genetic circuits driven by extrinsic stochastic processes. We propose a simplified approach to this problem, which can be used in the case when extrinsic fluctuations dominate the stochastic dynamics of the circuit (as appears to be the case in eukaryots). This approach is applied to a model of a single nonregulated gene that is driven by a certain gating process that affects the rate of transcription, and to a simplified version of the galactose utilization circuit in yeast.

  11. Stochastic Thermal Convection

    NASA Astrophysics Data System (ADS)

    Venturi, Daniele

    2005-11-01

    Stochastic bifurcations and stability of natural convective flows in 2d and 3d enclosures are investigated by the multi-element generalized polynomial chaos (ME-gPC) method (Xiu and Karniadakis, SISC, vol. 24, 2002). The Boussinesq approximation for the variation of physical properties is assumed. The stability analysis is first carried out in a deterministic sense, to determine steady state solutions and primary and secondary bifurcations. Stochastic simulations are then conducted around discontinuities and transitional regimes. It is found that these highly non-linear phenomena can be efficiently captured by the ME-gPC method. Finally, the main findings of the stochastic analysis and their implications for heat transfer will be discussed.

  12. Stochastic cooling at Fermilab

    SciTech Connect

    Marriner, J.

    1986-08-01

    The topics discussed are the stochastic cooling systems in use at Fermilab and some of the techniques that have been employed to meet the particular requirements of the anti-proton source. Stochastic cooling at Fermilab became of paramount importance about 5 years ago when the anti-proton source group at Fermilab abandoned the electron cooling ring in favor of a high flux anti-proton source which relied solely on stochastic cooling to achieve the phase space densities necessary for colliding proton and anti-proton beams. The Fermilab systems have constituted a substantial advance in the techniques of cooling including: large pickup arrays operating at microwave frequencies, extensive use of cryogenic techniques to reduce thermal noise, super-conducting notch filters, and the development of tools for controlling and for accurately phasing the system.

  13. Nested versus non-nested decomposition for asset allocation problems

    SciTech Connect

    Fan, Yuan-An; Carino, D.

    1994-12-31

    In this paper, multi-period asset allocation problems are formulated as multistage stochastic linear programs. Two-stage and three-stage L-shaped decomposition codes are developed using IBM OSL to solve the problems. The purpose of this study is to find out how many scenarios can be considered in the model and solved within a reasonable solution time using an efficient algorithm. Furthermore, we examine the tree structure of the scenarios in terms of realistic representation of asset allocation problems and computational efficiency. Test problems range in size from 1,000 scenarios to 64,000 scenarios and are generated from a multivariate normal distribution. Computational results are presented and some observations are discussed.

  14. Stochastic optical active rheology

    NASA Astrophysics Data System (ADS)

    Lee, Hyungsuk; Shin, Yongdae; Kim, Sun Taek; Reinherz, Ellis L.; Lang, Matthew J.

    2012-07-01

    We demonstrate a stochastic based method for performing active rheology using optical tweezers. By monitoring the displacement of an embedded particle in response to stochastic optical forces, a rapid estimate of the frequency dependent shear moduli of a sample is achieved in the range of 10-1-103 Hz. We utilize the method to probe linear viscoelastic properties of hydrogels at varied cross-linker concentrations. Combined with fluorescence imaging, our method demonstrates non-linear changes of bond strength between T cell receptors and an antigenic peptide due to force-induced cell activation.

  15. Stochastic Feedforward Control Technique

    NASA Technical Reports Server (NTRS)

    Halyo, Nesim

    1990-01-01

    Class of commanded trajectories modeled as stochastic process. Advanced Transport Operating Systems (ATOPS) research and development program conducted by NASA Langley Research Center aimed at developing capabilities for increases in capacities of airports, safe and accurate flight in adverse weather conditions including shear, winds, avoidance of wake vortexes, and reduced consumption of fuel. Advances in techniques for design of modern controls and increased capabilities of digital flight computers coupled with accurate guidance information from Microwave Landing System (MLS). Stochastic feedforward control technique developed within context of ATOPS program.

  16. Stochastic Gauss equations

    NASA Astrophysics Data System (ADS)

    Pierret, Frédéric

    2016-02-01

    We derived the equations of Celestial Mechanics governing the variation of the orbital elements under a stochastic perturbation, thereby generalizing the classical Gauss equations. Explicit formulas are given for the semimajor axis, the eccentricity, the inclination, the longitude of the ascending node, the pericenter angle, and the mean anomaly, which are expressed in term of the angular momentum vector H per unit of mass and the energy E per unit of mass. Together, these formulas are called the stochastic Gauss equations, and they are illustrated numerically on an example from satellite dynamics.

  17. Structures and stochastic methods

    SciTech Connect

    Cakmak, A.S.

    1987-01-01

    Studies and research on structures and stochastic methods in the soil dynamics and earthquake engineering filed are covered in this book. The first section is on structures and includes studies on bridges, loaded tanks, sliding structures and wood-framed houses. The second section covers dams, retaining walls and slopes. The third section on underground structures covers pipelines, water supply, fire loss, buried lifeline, and underground transmission lines. The final section is on stochastic methods and includes applications in earthquake response spectra, lifeline aqueduct systems, and various other areas.

  18. The Principal as Resource Allocator.

    ERIC Educational Resources Information Center

    Peterson, Kent D.

    The effect of political influences on the allocation of personnel, money, facilities, and equipment by elementary school principals is discussed in this paper. The use of Zald's political economy framework as a tool for understanding the principal's role in allocating resources is described by the author. He suggests that the principal occupies a…

  19. Stochastic trajectories of succession initiated by extreme climatic events.

    PubMed

    Kreyling, J; Jentsch, A; Beierkuhnlein, C

    2011-08-01

    Deterministic or rule-based succession is expected under homogeneous biotic and abiotic starting conditions. Effects of extreme climatic events such as drought, however, may alter these assembly rules by adding stochastic elements. We monitored the succession of species composition of 30 twin grassland communities with identical biotic and abiotic starting conditions in an initially sown diversity gradient between 1 and 16 species over 13 years. The stochasticity of succession, measured as the synchrony in the development of the species compositions of the twin plots, was strongly altered by the extreme warm and dry summer of 2003. Moreover, it was independent from past and present plant diversity and neighbourhood species compositions. Extreme climatic events can induce stochastic effects in community development and therefore impair predictability even under homogeneous abiotic conditions. Stochastic events may result in lasting shifts of community composition, as well as adverse and unforeseeable effects on the stability of ecological services.

  20. STOCHASTIC COOLING FOR BUNCHED BEAMS.

    SciTech Connect

    BLASKIEWICZ, M.

    2005-05-16

    Problems associated with bunched beam stochastic cooling are reviewed. A longitudinal stochastic cooling system for RHIC is under construction and has been partially commissioned. The state of the system and future plans are discussed.

  1. Stochastic entrainment of a stochastic oscillator.

    PubMed

    Wang, Guanyu; Peskin, Charles S

    2015-01-01

    In this work, we consider a stochastic oscillator described by a discrete-state continuous-time Markov chain, in which the states are arranged in a circle, and there is a constant probability per unit time of jumping from one state to the next in a specified direction around the circle. At each of a sequence of equally spaced times, the oscillator has a specified probability of being reset to a particular state. The focus of this work is the entrainment of the oscillator by this periodic but stochastic stimulus. We consider a distinguished limit, in which (i) the number of states of the oscillator approaches infinity, as does the probability per unit time of jumping from one state to the next, so that the natural mean period of the oscillator remains constant, (ii) the resetting probability approaches zero, and (iii) the period of the resetting signal approaches a multiple, by a ratio of small integers, of the natural mean period of the oscillator. In this distinguished limit, we use analytic and numerical methods to study the extent to which entrainment occurs.

  2. A stochastic model of eye lens growth.

    PubMed

    Šikić, Hrvoje; Shi, Yanrong; Lubura, Snježana; Bassnett, Steven

    2015-07-01

    The size and shape of the ocular lens must be controlled with precision if light is to be focused sharply on the retina. The lifelong growth of the lens depends on the production of cells in the anterior epithelium. At the lens equator, epithelial cells differentiate into fiber cells, which are added to the surface of the existing fiber cell mass, increasing its volume and area. We developed a stochastic model relating the rates of cell proliferation and death in various regions of the lens epithelium to deposition of fiber cells and radial lens growth. Epithelial population dynamics were modeled as a branching process with emigration and immigration between proliferative zones. Numerical simulations were in agreement with empirical measurements and demonstrated that, operating within the strict confines of lens geometry, a stochastic growth engine can produce the smooth and precise growth necessary for lens function. PMID:25816743

  3. 24 CFR 92.50 - Formula allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Formula allocation. 92.50 Section... Development HOME INVESTMENT PARTNERSHIPS PROGRAM Allocation Formula § 92.50 Formula allocation. (a) Jurisdictions eligible for a formula allocation. HUD will provide allocations of funds in amounts determined...

  4. 23 CFR 1240.15 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 1240.15 Section 1240.15 Highways NATIONAL... GUIDELINES SAFETY INCENTIVE GRANTS FOR USE OF SEAT BELTS-ALLOCATIONS BASED ON SEAT BELT USE RATES Determination of Allocations § 1240.15 Allocations. (a) Funds allocated under this part shall be available...

  5. Stochastic Models of Human Growth.

    ERIC Educational Resources Information Center

    Goodrich, Robert L.

    Stochastic difference equations of the Box-Jenkins form provide an adequate family of models on which to base the stochastic theory of human growth processes, but conventional time series identification methods do not apply to available data sets. A method to identify structure and parameters of stochastic difference equation models of human…

  6. On Stochastic Approximation.

    ERIC Educational Resources Information Center

    Wolff, Hans

    This paper deals with a stochastic process for the approximation of the root of a regression equation. This process was first suggested by Robbins and Monro. The main result here is a necessary and sufficient condition on the iteration coefficients for convergence of the process (convergence with probability one and convergence in the quadratic…

  7. Focus on stochastic thermodynamics

    NASA Astrophysics Data System (ADS)

    Van den Broeck, Christian; Sasa, Shin-ichi; Seifert, Udo

    2016-02-01

    We introduce the thirty papers collected in this ‘focus on’ issue. The contributions explore conceptual issues within and around stochastic thermodynamics, use this framework for the theoretical modeling and experimental investigation of specific systems, and provide further perspectives on and for this active field.

  8. 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.

  9. INSTRUCTIONAL CONFERENCE ON THE THEORY OF STOCHASTIC PROCESSES: Operator stochastic differential equations and stochastic semigroups

    NASA Astrophysics Data System (ADS)

    Skorokhod, A. V.

    1982-12-01

    CONTENTSIntroduction § 1. The finite-dimensional case § 2. Stochastic semigroups in the L2-strong theory § 3. Homogeneous strongly continuous semigroups with the group of the first moments § 4. Stochastic equations of diffusion type with constant coefficients § 5. Continuous homogeneous stochastic semigroups in the presence of two moments References

  10. Adaptive stochastic cellular automata: Applications

    NASA Astrophysics Data System (ADS)

    Qian, S.; Lee, Y. C.; Jones, R. D.; Barnes, C. W.; Flake, G. W.; O'Rourke, M. K.; Lee, K.; Chen, H. H.; Sun, G. Z.; Zhang, Y. Q.; Chen, D.; Giles, C. L.

    1990-09-01

    The stochastic learning cellular automata model has been applied to the problem of controlling unstable systems. Two example unstable systems studied are controlled by an adaptive stochastic cellular automata algorithm with an adaptive critic. The reinforcement learning algorithm and the architecture of the stochastic CA controller are presented. Learning to balance a single pole is discussed in detail. Balancing an inverted double pendulum highlights the power of the stochastic CA approach. The stochastic CA model is compared to conventional adaptive control and artificial neural network approaches.

  11. Stochastic computing with biomolecular automata

    NASA Astrophysics Data System (ADS)

    Adar, Rivka; Benenson, Yaakov; Linshiz, Gregory; Rosner, Amit; Tishby, Naftali; Shapiro, Ehud

    2004-07-01

    Stochastic computing has a broad range of applications, yet electronic computers realize its basic step, stochastic choice between alternative computation paths, in a cumbersome way. Biomolecular computers use a different computational paradigm and hence afford novel designs. We constructed a stochastic molecular automaton in which stochastic choice is realized by means of competition between alternative biochemical pathways, and choice probabilities are programmed by the relative molar concentrations of the software molecules coding for the alternatives. Programmable and autonomous stochastic molecular automata have been shown to perform direct analysis of disease-related molecular indicators in vitro and may have the potential to provide in situ medical diagnosis and cure.

  12. Optimal vaccination in a stochastic epidemic model of two non-interacting populations.

    PubMed

    Yuan, Edwin C; Alderson, David L; Stromberg, Sean; Carlson, Jean M

    2015-01-01

    Developing robust, quantitative methods to optimize resource allocations in response to epidemics has the potential to save lives and minimize health care costs. In this paper, we develop and apply a computationally efficient algorithm that enables us to calculate the complete probability distribution for the final epidemic size in a stochastic Susceptible-Infected-Recovered (SIR) model. Based on these results, we determine the optimal allocations of a limited quantity of vaccine between two non-interacting populations. We compare the stochastic solution to results obtained for the traditional, deterministic SIR model. For intermediate quantities of vaccine, the deterministic model is a poor estimate of the optimal strategy for the more realistic, stochastic case.

  13. Collaborative Resource Allocation

    NASA Technical Reports Server (NTRS)

    Wang, Yeou-Fang; Wax, Allan; Lam, Raymond; Baldwin, John; Borden, Chester

    2007-01-01

    Collaborative Resource Allocation Networking Environment (CRANE) Version 0.5 is a prototype created to prove the newest concept of using a distributed environment to schedule Deep Space Network (DSN) antenna times in a collaborative fashion. This program is for all space-flight and terrestrial science project users and DSN schedulers to perform scheduling activities and conflict resolution, both synchronously and asynchronously. Project schedulers can, for the first time, participate directly in scheduling their tracking times into the official DSN schedule, and negotiate directly with other projects in an integrated scheduling system. A master schedule covers long-range, mid-range, near-real-time, and real-time scheduling time frames all in one, rather than the current method of separate functions that are supported by different processes and tools. CRANE also provides private workspaces (both dynamic and static), data sharing, scenario management, user control, rapid messaging (based on Java Message Service), data/time synchronization, workflow management, notification (including emails), conflict checking, and a linkage to a schedule generation engine. The data structure with corresponding database design combines object trees with multiple associated mortal instances and relational database to provide unprecedented traceability and simplify the existing DSN XML schedule representation. These technologies are used to provide traceability, schedule negotiation, conflict resolution, and load forecasting from real-time operations to long-range loading analysis up to 20 years in the future. CRANE includes a database, a stored procedure layer, an agent-based middle tier, a Web service wrapper, a Windows Integrated Analysis Environment (IAE), a Java application, and a Web page interface.

  14. AdS duals of matrix strings

    NASA Astrophysics Data System (ADS)

    Morales, Jose F.; Samtleben, Henning

    2003-06-01

    We review recent work on the holographic duals of type II and heterotic matrix string theories described by warped AdS3 supergravities. In particular, we compute the spectra of Kaluza-Klein primaries for type I, II supergravities on warped AdS3 × S7 and match them with the primary operators in the dual two-dimensional gauge theories. The presence of non-trivial warp factors and dilaton profiles requires a modification of the familiar dictionary between masses and 'scaling' dimensions of fields and operators. We present these modifications for the general case of domain wall/QFT correspondences between supergravities on warped AdSd+1 × Sq geometries and super Yang-Mills theories with 16 supercharges.

  15. On the Fair Division of Multiple Stochastic Pies to Multiple Agents within the Nash Bargaining Solution

    PubMed Central

    Karmperis, Athanasios C.; Aravossis, Konstantinos; Tatsiopoulos, Ilias P.; Sotirchos, Anastasios

    2012-01-01

    The fair division of a surplus is one of the most widely examined problems. This paper focuses on bargaining problems with fixed disagreement payoffs where risk-neutral agents have reached an agreement that is the Nash-bargaining solution (NBS). We consider a stochastic environment, in which the overall return consists of multiple pies with uncertain sizes and we examine how these pies can be allocated with fairness among agents. Specifically, fairness is based on the Aristotle’s maxim: “equals should be treated equally and unequals unequally, in proportion to the relevant inequality”. In this context, fairness is achieved when all the individual stochastic surplus shares which are allocated to agents are distributed in proportion to the NBS. We introduce a novel algorithm, which can be used to compute the ratio of each pie that should be allocated to each agent, in order to ensure fairness within a symmetric or asymmetric NBS. PMID:23024752

  16. Inverse Statistics and Asset Allocation Efficiency

    NASA Astrophysics Data System (ADS)

    Bolgorian, Meysam

    In this paper using inverse statistics analysis, the effect of investment horizon on the efficiency of portfolio selection is examined. Inverse statistics analysis is a general tool also known as probability distribution of exit time that is used for detecting the distribution of the time in which a stochastic process exits from a zone. This analysis was used in Refs. 1 and 2 for studying the financial returns time series. This distribution provides an optimal investment horizon which determines the most likely horizon for gaining a specific return. Using samples of stocks from Tehran Stock Exchange (TSE) as an emerging market and S&P 500 as a developed market, effect of optimal investment horizon in asset allocation is assessed. It is found that taking into account the optimal investment horizon in TSE leads to more efficiency for large size portfolios while for stocks selected from S&P 500, regardless of portfolio size, this strategy does not only not produce more efficient portfolios, but also longer investment horizons provides more efficiency.

  17. Beamlets from stochastic acceleration.

    PubMed

    Perri, Silvia; Carbone, Vincenzo

    2008-09-01

    We investigate the dynamics of a realization of the stochastic Fermi acceleration mechanism. The model consists of test particles moving between two oscillating magnetic clouds and differs from the usual Fermi-Ulam model in two ways. (i) Particles can penetrate inside clouds before being reflected. (ii) Particles can radiate a fraction of their energy during the process. Since the Fermi mechanism is at work, particles are stochastically accelerated, even in the presence of the radiated energy. Furthermore, due to a kind of resonance between particles and oscillating clouds, the probability density function of particles is strongly modified, thus generating beams of accelerated particles rather than a translation of the whole distribution function to higher energy. This simple mechanism could account for the presence of beamlets in some space plasma physics situations.

  18. Stochastic ice stream dynamics

    NASA Astrophysics Data System (ADS)

    Mantelli, Elisa; Bertagni, Matteo Bernard; Ridolfi, Luca

    2016-08-01

    Ice streams are narrow corridors of fast-flowing ice that constitute the arterial drainage network of ice sheets. Therefore, changes in ice stream flow are key to understanding paleoclimate, sea level changes, and rapid disintegration of ice sheets during deglaciation. The dynamics of ice flow are tightly coupled to the climate system through atmospheric temperature and snow recharge, which are known exhibit stochastic variability. Here we focus on the interplay between stochastic climate forcing and ice stream temporal dynamics. Our work demonstrates that realistic climate fluctuations are able to (i) induce the coexistence of dynamic behaviors that would be incompatible in a purely deterministic system and (ii) drive ice stream flow away from the regime expected in a steady climate. We conclude that environmental noise appears to be crucial to interpreting the past behavior of ice sheets, as well as to predicting their future evolution.

  19. STOCHASTIC COOLING FOR RHIC.

    SciTech Connect

    BLASKIEWICZ,M.BRENNAN,J.M.CAMERON,P.WEI,J.

    2003-05-12

    Emittance growth due to Intra-Beam Scattering significantly reduces the heavy ion luminosity lifetime in RHIC. Stochastic cooling of the stored beam could improve things considerably by counteracting IBS and preventing particles from escaping the rf bucket [1]. High frequency bunched-beam stochastic cooling is especially challenging but observations of Schottky signals in the 4-8 GHz band indicate that conditions are favorable in RHIC [2]. We report here on measurements of the longitudinal beam transfer function carried out with a pickup kicker pair on loan from FNAL TEVATRON. Results imply that for ions a coasting beam description is applicable and we outline some general features of a viable momentum cooling system for RHIC.

  20. Stochastic ice stream dynamics.

    PubMed

    Mantelli, Elisa; Bertagni, Matteo Bernard; Ridolfi, Luca

    2016-08-01

    Ice streams are narrow corridors of fast-flowing ice that constitute the arterial drainage network of ice sheets. Therefore, changes in ice stream flow are key to understanding paleoclimate, sea level changes, and rapid disintegration of ice sheets during deglaciation. The dynamics of ice flow are tightly coupled to the climate system through atmospheric temperature and snow recharge, which are known exhibit stochastic variability. Here we focus on the interplay between stochastic climate forcing and ice stream temporal dynamics. Our work demonstrates that realistic climate fluctuations are able to (i) induce the coexistence of dynamic behaviors that would be incompatible in a purely deterministic system and (ii) drive ice stream flow away from the regime expected in a steady climate. We conclude that environmental noise appears to be crucial to interpreting the past behavior of ice sheets, as well as to predicting their future evolution. PMID:27457960

  1. Entropy of stochastic flows

    SciTech Connect

    Dorogovtsev, Andrei A

    2010-06-29

    For sets in a Hilbert space the concept of quadratic entropy is introduced. It is shown that this entropy is finite for the range of a stochastic flow of Brownian particles on R. This implies, in particular, the fact that the total time of the free travel in the Arratia flow of all particles that started from a bounded interval is finite. Bibliography: 10 titles.

  2. Ultimate open pit stochastic optimization

    NASA Astrophysics Data System (ADS)

    Marcotte, Denis; Caron, Josiane

    2013-02-01

    Classical open pit optimization (maximum closure problem) is made on block estimates, without directly considering the block grades uncertainty. We propose an alternative approach of stochastic optimization. The stochastic optimization is taken as the optimal pit computed on the block expected profits, rather than expected grades, computed from a series of conditional simulations. The stochastic optimization generates, by construction, larger ore and waste tonnages than the classical optimization. Contrary to the classical approach, the stochastic optimization is conditionally unbiased for the realized profit given the predicted profit. A series of simulated deposits with different variograms are used to compare the stochastic approach, the classical approach and the simulated approach that maximizes expected profit among simulated designs. Profits obtained with the stochastic optimization are generally larger than the classical or simulated pit. The main factor controlling the relative gain of stochastic optimization compared to classical approach and simulated pit is shown to be the information level as measured by the boreholes spacing/range ratio. The relative gains of the stochastic approach over the classical approach increase with the treatment costs but decrease with mining costs. The relative gains of the stochastic approach over the simulated pit approach increase both with the treatment and mining costs. At early stages of an open pit project, when uncertainty is large, the stochastic optimization approach appears preferable to the classical approach or the simulated pit approach for fair comparison of the values of alternative projects and for the initial design and planning of the open pit.

  3. A robust optimisation approach to the problem of supplier selection and allocation in outsourcing

    NASA Astrophysics Data System (ADS)

    Fu, Yelin; Keung Lai, Kin; Liang, Liang

    2016-03-01

    We formulate the supplier selection and allocation problem in outsourcing under an uncertain environment as a stochastic programming problem. Both the decision-maker's attitude towards risk and the penalty parameters for demand deviation are considered in the objective function. A service level agreement, upper bound for each selected supplier's allocation and the number of selected suppliers are considered as constraints. A novel robust optimisation approach is employed to solve this problem under different economic situations. Illustrative examples are presented with managerial implications highlighted to support decision-making.

  4. Subpopulation triage: how to allocate conservation effort among populations.

    PubMed

    McDonald-Madden, Eve; Baxter, Peter W J; Possingham, Hugh P

    2008-06-01

    Threatened species often exist in a small number of isolated subpopulations. Given limitations on conservation spending, managers must choose from strategies that range from managing just one subpopulation and risking all other subpopulations to managing all subpopulations equally and poorly, thereby risking the loss of all subpopulations. We took an economic approach to this problem in an effort to discover a simple rule of thumb for optimally allocating conservation effort among subpopulations. This rule was derived by maximizing the expected number of extant subpopulations remaining given n subpopulations are actually managed. We also derived a spatiotemporally optimized strategy through stochastic dynamic programming. The rule of thumb suggested that more subpopulations should be managed if the budget increases or if the cost of reducing local extinction probabilities decreases. The rule performed well against the exact optimal strategy that was the result of the stochastic dynamic program and much better than other simple strategies (e.g., always manage one extant subpopulation or half of the remaining subpopulation). We applied our approach to the allocation of funds in 2 contrasting case studies: reduction of poaching of Sumatran tigers (Panthera tigris sumatrae) and habitat acquisition for San Joaquin kit foxes (Vulpes macrotis mutica). For our estimated annual budget for Sumatran tiger management, the mean time to extinction was about 32 years. For our estimated annual management budget for kit foxes in the San Joaquin Valley, the mean time to extinction was approximately 24 years. Our framework allows managers to deal with the important question of how to allocate scarce conservation resources among subpopulations of any threatened species. PMID:18477029

  5. 15 CFR 335.4 - Allocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Allocation. 335.4 Section 335.4... § 335.4 Allocation. (a) For HTS 9902.51.11 and HTS 9902.51.15 each Tariff Rate Quota will be allocated separately. Allocation will be based on an applicant's Worsted Wool Suit production, on a weighted...

  6. On impulsive integrated pest management models with stochastic effects

    PubMed Central

    Akman, Olcay; Comar, Timothy D.; Hrozencik, Daniel

    2015-01-01

    We extend existing impulsive differential equation models for integrated pest management (IPM) by including stage structure for both predator and prey as well as by adding stochastic elements in the birth rate of the prey. Based on our model, we propose an approach that incorporates various competing stochastic components. This approach enables us to select a model with optimally determined weights for maximum accuracy and precision in parameter estimation. This is significant in the case of IPM because the proposed model accommodates varying unknown environmental and climatic conditions, which affect the resources needed for pest eradication. PMID:25954144

  7. Preserving the allocation ratio at every allocation with biased coin randomization and minimization in studies with unequal allocation.

    PubMed

    Kuznetsova, Olga M; Tymofyeyev, Yevgen

    2012-04-13

    The demand for unequal allocation in clinical trials is growing. Most commonly, the unequal allocation is achieved through permuted block randomization. However, other allocation procedures might be required to better approximate the allocation ratio in small samples, reduce the selection bias in open-label studies, or balance on baseline covariates. When these allocation procedures are generalized to unequal allocation, special care is to be taken to preserve the allocation ratio at every allocation step. This paper offers a way to expand the biased coin randomization to unequal allocation that preserves the allocation ratio at every allocation. The suggested expansion works with biased coin randomization that balances only on treatment group totals and with covariate-adaptive procedures that use a random biased coin element at every allocation. Balancing properties of the allocation ratio preserving biased coin randomization and minimization are described through simulations. It is demonstrated that these procedures are asymptotically protected against the shift in the rerandomization distribution identified for some examples of minimization with 1:2 allocation. The asymptotic shift in the rerandomization distribution of the difference in treatment means for an arbitrary unequal allocation procedure is explicitly derived in the paper.

  8. Collective credit allocation in science

    PubMed Central

    Shen, Hua-Wei; Barabási, Albert-László

    2014-01-01

    Collaboration among researchers is an essential component of the modern scientific enterprise, playing a particularly important role in multidisciplinary research. However, we continue to wrestle with allocating credit to the coauthors of publications with multiple authors, because the relative contribution of each author is difficult to determine. At the same time, the scientific community runs an informal field-dependent credit allocation process that assigns credit in a collective fashion to each work. Here we develop a credit allocation algorithm that captures the coauthors’ contribution to a publication as perceived by the scientific community, reproducing the informal collective credit allocation of science. We validate the method by identifying the authors of Nobel-winning papers that are credited for the discovery, independent of their positions in the author list. The method can also compare the relative impact of researchers working in the same field, even if they did not publish together. The ability to accurately measure the relative credit of researchers could affect many aspects of credit allocation in science, potentially impacting hiring, funding, and promotion decisions. PMID:25114238

  9. Collective credit allocation in science.

    PubMed

    Shen, Hua-Wei; Barabási, Albert-László

    2014-08-26

    Collaboration among researchers is an essential component of the modern scientific enterprise, playing a particularly important role in multidisciplinary research. However, we continue to wrestle with allocating credit to the coauthors of publications with multiple authors, because the relative contribution of each author is difficult to determine. At the same time, the scientific community runs an informal field-dependent credit allocation process that assigns credit in a collective fashion to each work. Here we develop a credit allocation algorithm that captures the coauthors' contribution to a publication as perceived by the scientific community, reproducing the informal collective credit allocation of science. We validate the method by identifying the authors of Nobel-winning papers that are credited for the discovery, independent of their positions in the author list. The method can also compare the relative impact of researchers working in the same field, even if they did not publish together. The ability to accurately measure the relative credit of researchers could affect many aspects of credit allocation in science, potentially impacting hiring, funding, and promotion decisions. PMID:25114238

  10. Agricultural Education: Value Adding.

    ERIC Educational Resources Information Center

    Riesenberg, Lou E.; And Others

    1989-01-01

    This issue develops the theme of "Agricultural Education--Value Adding." The concept value adding has been a staple in the world of agricultural business for describing adding value to a commodity that would profit the producer and the local community. Agricultural education should add value to individuals and society to justify agricultural…

  11. Stochastic Flow Cascades

    NASA Astrophysics Data System (ADS)

    Eliazar, Iddo I.; Shlesinger, Michael F.

    2012-01-01

    We introduce and explore a Stochastic Flow Cascade (SFC) model: A general statistical model for the unidirectional flow through a tandem array of heterogeneous filters. Examples include the flow of: (i) liquid through heterogeneous porous layers; (ii) shocks through tandem shot noise systems; (iii) signals through tandem communication filters. The SFC model combines together the Langevin equation, convolution filters and moving averages, and Poissonian randomizations. A comprehensive analysis of the SFC model is carried out, yielding closed-form results. Lévy laws are shown to universally emerge from the SFC model, and characterize both heavy tailed retention times (Noah effect) and long-ranged correlations (Joseph effect).

  12. Stochastic thermodynamics of resetting

    NASA Astrophysics Data System (ADS)

    Fuchs, Jaco; Goldt, Sebastian; Seifert, Udo

    2016-03-01

    Stochastic dynamics with random resetting leads to a non-equilibrium steady state. Here, we consider the thermodynamics of resetting by deriving the first and second law for resetting processes far from equilibrium. We identify the contributions to the entropy production of the system which arise due to resetting and show that they correspond to the rate with which information is either erased or created. Using Landauer's principle, we derive a bound on the amount of work that is required to maintain a resetting process. We discuss different regimes of resetting, including a Maxwell demon scenario where heat is extracted from a bath at constant temperature.

  13. Stochastic ontogenetic growth model

    NASA Astrophysics Data System (ADS)

    West, B. J.; West, D.

    2012-02-01

    An ontogenetic growth model (OGM) for a thermodynamically closed system is generalized to satisfy both the first and second law of thermodynamics. The hypothesized stochastic ontogenetic growth model (SOGM) is shown to entail the interspecies allometry relation by explicitly averaging the basal metabolic rate and the total body mass over the steady-state probability density for the total body mass (TBM). This is the first derivation of the interspecies metabolic allometric relation from a dynamical model and the asymptotic steady-state distribution of the TBM is fit to data and shown to be inverse power law.

  14. Strategic planning for disaster recovery with stochastic last mile distribution

    SciTech Connect

    Bent, Russell Whitford; Van Hentenryck, Pascal; Coffrin, Carleton

    2010-01-01

    This paper considers the single commodity allocation problem (SCAP) for disaster recovery, a fundamental problem faced by all populated areas. SCAPs are complex stochastic optimization problems that combine resource allocation, warehouse routing, and parallel fleet routing. Moreover, these problems must be solved under tight runtime constraints to be practical in real-world disaster situations. This paper formalizes the specification of SCAPs and introduces a novel multi-stage hybrid-optimization algorithm that utilizes the strengths of mixed integer programming, constraint programming, and large neighborhood search. The algorithm was validated on hurricane disaster scenarios generated by Los Alamos National Laboratory using state-of-the-art disaster simulation tools and is deployed to aid federal organizations in the US.

  15. Software For Allocation Of Tolerances

    NASA Technical Reports Server (NTRS)

    Fernandez, Ken; Raman, Shivakumar; Pulat, Simin

    1992-01-01

    Collection of computer programs being developed to assist engineers in allocating tolerances to dimensions of components and assemblies. System reflects tolerancing expertise of design and manufacturing engineers; helps engineers maintain comprehensive tolerancing policy and overview that might otherwise get lost when attending to details of design and manufacturing processes. Necessary to allocate tolerances for three main reasons: tolerances allow for variations in dimensions of components as manufactured; assembly of two or more components, dimensions lie between specified limits; and part replaced must fit in place.

  16. Stochastic blind motion deblurring.

    PubMed

    Xiao, Lei; Gregson, James; Heide, Felix; Heidrich, Wolfgang

    2015-10-01

    Blind motion deblurring from a single image is a highly under-constrained problem with many degenerate solutions. A good approximation of the intrinsic image can, therefore, only be obtained with the help of prior information in the form of (often nonconvex) regularization terms for both the intrinsic image and the kernel. While the best choice of image priors is still a topic of ongoing investigation, this research is made more complicated by the fact that historically each new prior requires the development of a custom optimization method. In this paper, we develop a stochastic optimization method for blind deconvolution. Since this stochastic solver does not require the explicit computation of the gradient of the objective function and uses only efficient local evaluation of the objective, new priors can be implemented and tested very quickly. We demonstrate that this framework, in combination with different image priors produces results with Peak Signal-to-Noise Ratio (PSNR) values that match or exceed the results obtained by much more complex state-of-the-art blind motion deblurring algorithms. PMID:25974941

  17. Task allocation among multiple intelligent robots

    NASA Technical Reports Server (NTRS)

    Gasser, L.; Bekey, G.

    1987-01-01

    Researchers describe the design of a decentralized mechanism for allocating assembly tasks in a multiple robot assembly workstation. Currently, the approach focuses on distributed allocation to explore its feasibility and its potential for adaptability to changing circumstances, rather than for optimizing throughput. Individual greedy robots make their own local allocation decisions using both dynamic allocation policies which propagate through a network of allocation goals, and local static and dynamic constraints describing which robots are elibible for which assembly tasks. Global coherence is achieved by proper weighting of allocation pressures propagating through the assembly plan. Deadlock avoidance and synchronization is achieved using periodic reassessments of local allocation decisions, ageing of allocation goals, and short-term allocation locks on goals.

  18. Variance decomposition in stochastic simulators

    NASA Astrophysics Data System (ADS)

    Le Maître, O. P.; Knio, O. M.; Moraes, A.

    2015-06-01

    This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

  19. Variance decomposition in stochastic simulators.

    PubMed

    Le Maître, O P; Knio, O M; Moraes, A

    2015-06-28

    This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

  20. On the efficacy of stochastic collocation, stochastic Galerkin, and stochastic reduced order models for solving stochastic problems

    DOE PAGES

    Richard V. Field, Jr.; Emery, John M.; Grigoriu, Mircea Dan

    2015-05-19

    The stochastic collocation (SC) and stochastic Galerkin (SG) methods are two well-established and successful approaches for solving general stochastic problems. A recently developed method based on stochastic reduced order models (SROMs) can also be used. Herein we provide a comparison of the three methods for some numerical examples; our evaluation only holds for the examples considered in the paper. The purpose of the comparisons is not to criticize the SC or SG methods, which have proven very useful for a broad range of applications, nor is it to provide overall ratings of these methods as compared to the SROM method.more » Furthermore, our objectives are to present the SROM method as an alternative approach to solving stochastic problems and provide information on the computational effort required by the implementation of each method, while simultaneously assessing their performance for a collection of specific problems.« less

  1. Variance decomposition in stochastic simulators

    SciTech Connect

    Le Maître, O. P.; Knio, O. M.; Moraes, A.

    2015-06-28

    This work aims at the development of a mathematical and computational approach that enables quantification of the inherent sources of stochasticity and of the corresponding sensitivities in stochastic simulations of chemical reaction networks. The approach is based on reformulating the system dynamics as being generated by independent standardized Poisson processes. This reformulation affords a straightforward identification of individual realizations for the stochastic dynamics of each reaction channel, and consequently a quantitative characterization of the inherent sources of stochasticity in the system. By relying on the Sobol-Hoeffding decomposition, the reformulation enables us to perform an orthogonal decomposition of the solution variance. Thus, by judiciously exploiting the inherent stochasticity of the system, one is able to quantify the variance-based sensitivities associated with individual reaction channels, as well as the importance of channel interactions. Implementation of the algorithms is illustrated in light of simulations of simplified systems, including the birth-death, Schlögl, and Michaelis-Menten models.

  2. Stochastic simulation of transport phenomena

    SciTech Connect

    Wedgewood, L.E.; Geurts, K.R.

    1995-10-01

    In this paper, four examples are given to demonstrate how stochastic simulations can be used as a method to obtain numerical solutions to transport problems. The problems considered are two-dimensional heat conduction, mass diffusion with reaction, the start-up of Poiseuille flow, and Couette flow of a suspension of Hookean dumbbells. The first three examples are standard problems with well-known analytic solutions which can be used to verify the results of the stochastic simulation. The fourth example combines a Brownian dynamics simulation for Hookean dumbbells, a crude model of a dilute polymer suspension, and a stochastic simulation for the suspending, Newtonian fluid. These examples illustrate appropriate methods for handling source/sink terms and initial and boundary conditions. The stochastic simulation results compare well with the analytic solutions and other numerical solutions. The goal of this paper is to demonstrate the wide applicability of stochastic simulation as a numerical method for transport problems.

  3. On the efficacy of stochastic collocation, stochastic Galerkin, and stochastic reduced order models for solving stochastic problems

    SciTech Connect

    Richard V. Field, Jr.; Emery, John M.; Grigoriu, Mircea Dan

    2015-05-19

    The stochastic collocation (SC) and stochastic Galerkin (SG) methods are two well-established and successful approaches for solving general stochastic problems. A recently developed method based on stochastic reduced order models (SROMs) can also be used. Herein we provide a comparison of the three methods for some numerical examples; our evaluation only holds for the examples considered in the paper. The purpose of the comparisons is not to criticize the SC or SG methods, which have proven very useful for a broad range of applications, nor is it to provide overall ratings of these methods as compared to the SROM method. Furthermore, our objectives are to present the SROM method as an alternative approach to solving stochastic problems and provide information on the computational effort required by the implementation of each method, while simultaneously assessing their performance for a collection of specific problems.

  4. Regulating nutrient allocation in plants

    SciTech Connect

    Udvardi, Michael; Yang, Jiading; Worley, Eric

    2014-12-09

    The invention provides coding and promoter sequences for a VS-1 and AP-2 gene, which affects the developmental process of senescence in plants. Vectors, transgenic plants, seeds, and host cells comprising heterologous VS-1 and AP-2 genes are also provided. Additionally provided are methods of altering nutrient allocation and composition in a plant using the VS-1 and AP-2 genes.

  5. Administrators' Decisions about Resource Allocation

    ERIC Educational Resources Information Center

    Knight, William E.; Folkins, John W.; Hakel, Milton D.; Kennell, Richard P.

    2011-01-01

    Do academic administrators make decisions about resource allocation differently depending on the discipline receiving the funding? Does an administrator's academic identity influence these decisions? This study explored those questions with a sample of 1,690 academic administrators at doctoral-research universities. Participants used fictional…

  6. Report on Tribal Priority Allocations.

    ERIC Educational Resources Information Center

    Bureau of Indian Affairs (Dept. of Interior), Washington, DC.

    As part of Bureau of Indian Affairs (BIA) funding, Tribal Priority Allocations (TPA) are the principal source of funds for tribal governments and agency offices at the reservation level. According to their unique needs and circumstances, tribes may prioritize funding among eight general categories: government, human services, education, public…

  7. The Discipline of Asset Allocation.

    ERIC Educational Resources Information Center

    Petzel, Todd E.

    2000-01-01

    Discussion of asset allocation for college/university endowment funds focuses on three levels of risk: (1) the absolute risk of the portfolio (usually leading to asset diversification); (2) the benchmark risk (usually comparison with peer institutions; and (3) personal career risk (which may incline managers toward maximizing short-term returns,…

  8. Adding flavor to AdS4/CFT3

    NASA Astrophysics Data System (ADS)

    Ammon, Martin; Erdmenger, Johanna; Meyer, René; O'Bannon, Andy; Wrase, Timm

    2009-11-01

    Aharony, Bergman, Jafferis, and Maldacena have proposed that the low-energy description of multiple M2-branes at a Bbb C4/Bbb Zk singularity is a (2+1)-dimensional Script N = 6 supersymmetric U(Nc) × U(Nc) Chern-Simons matter theory, the ABJM theory. In the large-Nc limit, its holographic dual is supergravity in AdS4 × S7/Bbb Zk. We study various ways to add fields that transform in the fundamental representation of the gauge groups, i.e. flavor fields, to the ABJM theory. We work in a probe limit and perform analyses in both the supergravity and field theory descriptions. In the supergravity description we find a large class of supersymmetric embeddings of probe flavor branes. In the field theory description, we present a general method to determine the couplings of the flavor fields to the fields of the ABJM theory. We then study four examples in detail: codimension-zero Script N = 3 supersymmetric flavor, described in supergravity by Kaluza-Klein monopoles or D6-branes; codimension-one Script N = (0,6) supersymmetric chiral flavor, described by D8-branes; codimension-one Script N = (3,3) supersymmetric non-chiral flavor, described by M5/D4-branes; codimension-two Script N = 4 supersymmetric flavor, described by M2/D2-branes. Finally we discuss special physical equivalences between brane embeddings in M-theory, and their interpretation in the field theory description.

  9. Stochastic resonance in psychophysics and in animal behavior.

    PubMed

    Ward, Lawrence M; Neiman, Alexander; Moss, Frank

    2002-08-01

    A recent analysis of the energy detector model in sensory psychophysics concluded that stochastic resonance does not occur in a measure of signal detectability ( d'), but can occur in a percent-correct measure of performance as an epiphenomenon of nonoptimal criterion placement [Tougaard (2000) Biol Cybern 83: 471-480]. When generalized to signal detection in sensory systems in general, this conclusion is a serious challenge to the idea that stochastic resonance could play a significant role in sensory processing in humans and other animals. It also seems to be inconsistent with recent demonstrations of stochastic resonance in sensory systems of both nonhuman animals and humans using measures of system performance such as signal-to-noise ratio of power spectral densities and percent-correct detections in a two-interval forced-choice paradigm, both closely related to d'. In this paper we address this apparent dilemma by discussing several models of how stochastic resonance can arise in signal detection systems, including especially those that implement a "soft threshold" at the input transform stage. One example involves redefining d' for energy increments in terms of parameters of the spike-count distribution of FitzHugh-Nagumo neurons. Another involves a Poisson spike generator that receives an exponentially transformed noisy periodic signal. In this case it can be shown that the signal-to-noise ratio of the power spectral density at the signal frequency, which exhibits stochastic resonance, is proportional to d'. Finally, a variant of d' is shown to exhibit stochastic resonance when calculated directly from the distributions of power spectral densities at the signal frequency resulting from transformation of noise alone and a noisy signal by a sufficiently steep nonlinear response function. All of these examples, and others from the literature, imply that stochastic resonance is more than an epiphenomenon, although significant limitations to the extent to which

  10. Twistor methods for AdS5

    NASA Astrophysics Data System (ADS)

    Adamo, Tim; Skinner, David; Williams, Jack

    2016-08-01

    We consider the application of twistor theory to five-dimensional anti-de Sitter space. The twistor space of AdS5 is the same as the ambitwistor space of the four-dimensional conformal boundary; the geometry of this correspondence is reviewed for both the bulk and boundary. A Penrose transform allows us to describe free bulk fields, with or without mass, in terms of data on twistor space. Explicit representatives for the bulk-to-boundary propagators of scalars and spinors are constructed, along with twistor action functionals for the free theories. Evaluating these twistor actions on bulk-to-boundary propagators is shown to produce the correct two-point functions.

  11. AdS3: the NHEK generation

    NASA Astrophysics Data System (ADS)

    Bena, Iosif; Heurtier, Lucien; Puhm, Andrea

    2016-05-01

    It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.

  12. Switching of bound vector solitons for the coupled nonlinear Schroedinger equations with nonhomogenously stochastic perturbations

    SciTech Connect

    Sun Zhiyuan; Yu Xin; Liu Ying; Gao Yitian

    2012-12-15

    We investigate the dynamics of the bound vector solitons (BVSs) for the coupled nonlinear Schroedinger equations with the nonhomogenously stochastic perturbations added on their dispersion terms. Soliton switching (besides soliton breakup) can be observed between the two components of the BVSs. Rate of the maximum switched energy (absolute values) within the fixed propagation distance (about 10 periods of the BVSs) enhances in the sense of statistics when the amplitudes of stochastic perturbations increase. Additionally, it is revealed that the BVSs with enhanced coherence are more robust against the perturbations with nonhomogenous stochasticity. Diagram describing the approximate borders of the splitting and non-splitting areas is also given. Our results might be helpful in dynamics of the BVSs with stochastic noises in nonlinear optical fibers or with stochastic quantum fluctuations in Bose-Einstein condensates.

  13. Shadows, currents, and AdS fields

    SciTech Connect

    Metsaev, R. R.

    2008-11-15

    Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.

  14. Stochastic reconstruction of sandstones

    PubMed

    Manwart; Torquato; Hilfer

    2000-07-01

    A simulated annealing algorithm is employed to generate a stochastic model for a Berea sandstone and a Fontainebleau sandstone, with each a prescribed two-point probability function, lineal-path function, and "pore size" distribution function, respectively. We find that the temperature decrease of the annealing has to be rather quick to yield isotropic and percolating configurations. A comparison of simple morphological quantities indicates good agreement between the reconstructions and the original sandstones. Also, the mean survival time of a random walker in the pore space is reproduced with good accuracy. However, a more detailed investigation by means of local porosity theory shows that there may be significant differences of the geometrical connectivity between the reconstructed and the experimental samples.

  15. Stochastic patch exploitation model

    PubMed Central

    Rita, H.; Ranta, E.

    1998-01-01

    A solitary animal is foraging in a patch consisting of discrete prey items. We develop a stochastic model for the accumulation of gain as a function of elapsed time in the patch. The model is based on the waiting times between subsequent encounters with the prey items. The novelty of the model is in that it renders possible–via parameterization of the waiting time distributions: the incorporation of different foraging situations and patch structures into the gain process. The flexibility of the model is demonstrated with different foraging scenarios. Dependence of gain expectation and variance of the parameters of the waiting times is studied under these conditions. The model allows us to comment upon some of the basic concepts in contemporary foraging theory.

  16. Dynamic Resource Allocation in Disaster Response: Tradeoffs in Wildfire Suppression

    PubMed Central

    Petrovic, Nada; Alderson, David L.; Carlson, Jean M.

    2012-01-01

    Challenges associated with the allocation of limited resources to mitigate the impact of natural disasters inspire fundamentally new theoretical questions for dynamic decision making in coupled human and natural systems. Wildfires are one of several types of disaster phenomena, including oil spills and disease epidemics, where (1) the disaster evolves on the same timescale as the response effort, and (2) delays in response can lead to increased disaster severity and thus greater demand for resources. We introduce a minimal stochastic process to represent wildfire progression that nonetheless accurately captures the heavy tailed statistical distribution of fire sizes observed in nature. We then couple this model for fire spread to a series of response models that isolate fundamental tradeoffs both in the strength and timing of response and also in division of limited resources across multiple competing suppression efforts. Using this framework, we compute optimal strategies for decision making scenarios that arise in fire response policy. PMID:22514605

  17. Phase transitions in crowd dynamics of resource allocation.

    PubMed

    Ghosh, Asim; De Martino, Daniele; Chatterjee, Arnab; Marsili, Matteo; Chakrabarti, Bikas K

    2012-02-01

    We define and study a class of resource allocation processes where gN agents, by repeatedly visiting N resources, try to converge to an optimal configuration where each resource is occupied by at most one agent. The process exhibits a phase transition, as the density g of agents grows, from an absorbing to an active phase. In the latter, even if the number of resources is in principle enough for all agents (g<1), the system never settles to a frozen configuration. We recast these processes in terms of zero-range interacting particles, studying analytically the mean field dynamics and investigating numerically the phase transition in finite dimensions. We find a good agreement with the critical exponents of the stochastic fixed-energy sandpile. The lack of coordination in the active phase also leads to a nontrivial faster-is-slower effect.

  18. Finite-time state feedback stabilisation of stochastic high-order nonlinear feedforward systems

    NASA Astrophysics Data System (ADS)

    Xie, Xue-Jun; Zhang, Xing-Hui; Zhang, Kemei

    2016-07-01

    This paper studies the finite-time state feedback stabilisation of stochastic high-order nonlinear feedforward systems. Based on the stochastic Lyapunov theorem on finite-time stability, by using the homogeneous domination method, the adding one power integrator and sign function method, constructing a ? Lyapunov function and verifying the existence and uniqueness of solution, a continuous state feedback controller is designed to guarantee the closed-loop system finite-time stable in probability.

  19. A stochastic multi-symplectic scheme for stochastic Maxwell equations with additive noise

    SciTech Connect

    Hong, Jialin; Zhang, Liying

    2014-07-01

    In this paper we investigate a stochastic multi-symplectic method for stochastic Maxwell equations with additive noise. Based on the stochastic version of variational principle, we find a way to obtain the stochastic multi-symplectic structure of three-dimensional (3-D) stochastic Maxwell equations with additive noise. We propose a stochastic multi-symplectic scheme and show that it preserves the stochastic multi-symplectic conservation law and the local and global stochastic energy dissipative properties, which the equations themselves possess. Numerical experiments are performed to verify the numerical behaviors of the stochastic multi-symplectic scheme.

  20. A Systems Approach for Allocating Educational Space.

    ERIC Educational Resources Information Center

    Florida Univ., Gainesville. Center for Community Needs Assessment.

    A computer simulation model for allocating facilities and physical space is presented as a means of optimally allocating available educational resources. The model allows the decisionmaker to change specific program allocations, system parameters, and other controllable variables in order to determine the effects, both cost and utility, of these…

  1. 40 CFR 74.26 - Allocation formula.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) SULFUR DIOXIDE OPT-INS Allowance Calculations for Combustion Sources § 74.26 Allocation formula. (a) The Administrator will calculate the annual allowance allocation for a combustion source based on the data... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Allocation formula. 74.26 Section...

  2. 49 CFR 262.5 - Allocation requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Allocation requirements. 262.5 Section 262.5... IMPROVEMENT PROJECTS § 262.5 Allocation requirements. At least fifty percent of all grant funds awarded under... than $20,000,000 each. Designated, high-priority projects will be excluded from this allocation...

  3. 39 CFR 3060.12 - Asset allocation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Asset allocation. 3060.12 Section 3060.12 Postal... COMPETITIVE PRODUCTS ENTERPRISE § 3060.12 Asset allocation. Within 6 months of January 23, 2009, and for each... competitive products enterprise using a method of allocation based on appropriate revenue or cost...

  4. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Allocation formula. 923.110 Section... MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration Grants § 923.110 Allocation formula. (a) As required by subsection 306(a), the Secretary may make...

  5. 25 CFR 39.902 - Allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Allocation. 39.902 Section 39.902 Indians BUREAU OF... Maintenance and Minor Repair Fund § 39.902 Allocation. (a) Interim Maintenance and Minor Repair funds shall be... determining school allocations shall be taken from the facilities inventory maintained by the Division...

  6. 24 CFR 945.203 - Allocation plan.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Allocation plan. 945.203 Section... FAMILIES Application and Approval Procedures § 945.203 Allocation plan. (a) Applicable terminology. (1) As used in this section, the terms “initial allocation plan” refers to the PHA's first submission of...

  7. 24 CFR 594.15 - Allocation amounts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Allocation amounts. 594.15 Section... DEVELOPMENT COMMUNITY FACILITIES JOHN HEINZ NEIGHBORHOOD DEVELOPMENT PROGRAM Funding Allocation and Criteria § 594.15 Allocation amounts. (a) Amounts and match requirement. HUD will make grants, in the form...

  8. Communication patterns and allocation strategies.

    SciTech Connect

    Leung, Vitus Joseph; Mache, Jens Wolfgang; Bunde, David P.

    2004-01-01

    Motivated by observations about job runtimes on the CPlant system, we use a trace-driven microsimulator to begin characterizing the performance of different classes of allocation algorithms on jobs with different communication patterns in space-shared parallel systems with mesh topology. We show that relative performance varies considerably with communication pattern. The Paging strategy using the Hilbert space-filling curve and the Best Fit heuristic performed best across several communication patterns.

  9. Minority Transportation Expenditure Allocation Model

    SciTech Connect

    Vyas, Anant D.; Santini, Danilo J.; Marik, Sheri K.

    1993-04-12

    MITRAM (Minority TRansportation expenditure Allocation Model) can project various transportation related attributes of minority (Black and Hispanic) and majority (white) populations. The model projects vehicle ownership, vehicle miles of travel, workers, new car and on-road fleet fuel economy, amount and share of household income spent on gasoline, and household expenditures on public transportation and taxis. MITRAM predicts reactions to sustained fuel price changes for up to 10 years after the change.

  10. Stability analysis of multi-group deterministic and stochastic epidemic models with vaccination rate

    NASA Astrophysics Data System (ADS)

    Wang, Zhi-Gang; Gao, Rui-Mei; Fan, Xiao-Ming; Han, Qi-Xing

    2014-09-01

    We discuss in this paper a deterministic multi-group MSIR epidemic model with a vaccination rate, the basic reproduction number ℛ0, a key parameter in epidemiology, is a threshold which determines the persistence or extinction of the disease. By using Lyapunov function techniques, we show if ℛ0 is greater than 1 and the deterministic model obeys some conditions, then the disease will prevail, the infective persists and the endemic state is asymptotically stable in a feasible region. If ℛ0 is less than or equal to 1, then the infective disappear so the disease dies out. In addition, stochastic noises around the endemic equilibrium will be added to the deterministic MSIR model in order that the deterministic model is extended to a system of stochastic ordinary differential equations. In the stochastic version, we carry out a detailed analysis on the asymptotic behavior of the stochastic model. In addition, regarding the value of ℛ0, when the stochastic system obeys some conditions and ℛ0 is greater than 1, we deduce the stochastic system is stochastically asymptotically stable. Finally, the deterministic and stochastic model dynamics are illustrated through computer simulations.

  11. Stochastic roots of growth phenomena

    NASA Astrophysics Data System (ADS)

    De Lauro, E.; De Martino, S.; De Siena, S.; Giorno, V.

    2014-05-01

    We show that the Gompertz equation describes the evolution in time of the median of a geometric stochastic process. Therefore, we induce that the process itself generates the growth. This result allows us further to exploit a stochastic variational principle to take account of self-regulation of growth through feedback of relative density variations. The conceptually well defined framework so introduced shows its usefulness by suggesting a form of control of growth by exploiting external actions.

  12. Stochastic superparameterization in quasigeostrophic turbulence

    SciTech Connect

    Grooms, Ian; Majda, Andrew J.

    2014-08-15

    In this article we expand and develop the authors' recent proposed methodology for efficient stochastic superparameterization algorithms for geophysical turbulence. Geophysical turbulence is characterized by significant intermittent cascades of energy from the unresolved to the resolved scales resulting in complex patterns of waves, jets, and vortices. Conventional superparameterization simulates large scale dynamics on a coarse grid in a physical domain, and couples these dynamics to high-resolution simulations on periodic domains embedded in the coarse grid. Stochastic superparameterization replaces the nonlinear, deterministic eddy equations on periodic embedded domains by quasilinear stochastic approximations on formally infinite embedded domains. The result is a seamless algorithm which never uses a small scale grid and is far cheaper than conventional SP, but with significant success in difficult test problems. Various design choices in the algorithm are investigated in detail here, including decoupling the timescale of evolution on the embedded domains from the length of the time step used on the coarse grid, and sensitivity to certain assumed properties of the eddies (e.g. the shape of the assumed eddy energy spectrum). We present four closures based on stochastic superparameterization which elucidate the properties of the underlying framework: a ‘null hypothesis’ stochastic closure that uncouples the eddies from the mean, a stochastic closure with nonlinearly coupled eddies and mean, a nonlinear deterministic closure, and a stochastic closure based on energy conservation. The different algorithms are compared and contrasted on a stringent test suite for quasigeostrophic turbulence involving two-layer dynamics on a β-plane forced by an imposed background shear. The success of the algorithms developed here suggests that they may be fruitfully applied to more realistic situations. They are expected to be particularly useful in providing accurate and

  13. Stochastic Evolution of Halo Spin

    NASA Astrophysics Data System (ADS)

    Kim, Juhan

    2015-08-01

    We will introduce an excursion set model for the evolution of halo spin from cosmological N-body simulations. A stochastic differential equation is derived from the definition of halo spin and the distribution of angular momentum changes are measured from simulations. The log-normal distribution of halo spin is found to be a natural consequence of the stochastic differential equation and the resulting spin distribution is found be a function of local environments, halo mass, and redshift.

  14. Stochastic superparameterization in quasigeostrophic turbulence

    NASA Astrophysics Data System (ADS)

    Grooms, Ian; Majda, Andrew J.

    2014-08-01

    In this article we expand and develop the authors' recent proposed methodology for efficient stochastic superparameterization algorithms for geophysical turbulence. Geophysical turbulence is characterized by significant intermittent cascades of energy from the unresolved to the resolved scales resulting in complex patterns of waves, jets, and vortices. Conventional superparameterization simulates large scale dynamics on a coarse grid in a physical domain, and couples these dynamics to high-resolution simulations on periodic domains embedded in the coarse grid. Stochastic superparameterization replaces the nonlinear, deterministic eddy equations on periodic embedded domains by quasilinear stochastic approximations on formally infinite embedded domains. The result is a seamless algorithm which never uses a small scale grid and is far cheaper than conventional SP, but with significant success in difficult test problems. Various design choices in the algorithm are investigated in detail here, including decoupling the timescale of evolution on the embedded domains from the length of the time step used on the coarse grid, and sensitivity to certain assumed properties of the eddies (e.g. the shape of the assumed eddy energy spectrum). We present four closures based on stochastic superparameterization which elucidate the properties of the underlying framework: a ‘null hypothesis' stochastic closure that uncouples the eddies from the mean, a stochastic closure with nonlinearly coupled eddies and mean, a nonlinear deterministic closure, and a stochastic closure based on energy conservation. The different algorithms are compared and contrasted on a stringent test suite for quasigeostrophic turbulence involving two-layer dynamics on a β-plane forced by an imposed background shear. The success of the algorithms developed here suggests that they may be fruitfully applied to more realistic situations. They are expected to be particularly useful in providing accurate and

  15. Allocating Variability and Reserve Requirements (Presentation)

    SciTech Connect

    Kirby, B.; King, J.; Milligan, M.

    2011-10-01

    This presentation describes how you could conceivably allocate variability and reserve requirements, including how to allocate aggregation benefits. Conclusions of this presentation are: (1) Aggregation provides benefits because individual requirements are not 100% correlated; (2) Method needed to allocate reduced requirement among participants; (3) Differences between allocation results are subtle - (a) Not immediately obvious which method is 'better'; (b) Many are numerically 'correct', they sum to the physical requirement; (c) Many are not 'fair', Results depend on sub-aggregation and/or the order individuals are included; and (4) Vector allocation method is simple and fair.

  16. A stochastic conflict resolution model for water quality management in reservoir river systems

    NASA Astrophysics Data System (ADS)

    Kerachian, Reza; Karamouz, Mohammad

    2007-04-01

    In this paper, optimal operating rules for water quality management in reservoir-river systems are developed using a methodology combining a water quality simulation model and a stochastic GA-based conflict resolution technique. As different decision-makers and stakeholders are involved in the water quality management in reservoir-river systems, a new stochastic form of the Nash bargaining theory is used to resolve the existing conflict of interests related to water supply to different demands, allocated water quality and waste load allocation in downstream river. The expected value of the Nash product is considered as the objective function of the model which can incorporate the inherent uncertainty of reservoir inflow. A water quality simulation model is also developed to simulate the thermal stratification cycle in the reservoir, the quality of releases from different outlets as well as the temporal and spatial variation of the pollutants in the downstream river. In this study, a Varying Chromosome Length Genetic Algorithm (VLGA), which has computational advantages comparing to other alternative models, is used. VLGA provides a good initial solution for Simple Genetic Algorithms and comparing to Stochastic Dynamic Programming (SDP) reduces the number of state transitions checked in each stage. The proposed model, which is called Stochastic Varying Chromosome Length Genetic Algorithm with water Quality constraints (SVLGAQ), is applied to the Ghomrud Reservoir-River system in the central part of Iran. The results show, the proposed model for reservoir operation and waste load allocation can reduce the salinity of the allocated water demands as well as the salinity build-up in the reservoir.

  17. ADS pilot program Plan

    NASA Technical Reports Server (NTRS)

    Clauson, J.; Heuser, J.

    1981-01-01

    The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.

  18. Delayed stochastic control

    NASA Astrophysics Data System (ADS)

    Hosaka, Tadaaki; Ohira, Toru; Lucian, Christian; Milton, John

    2005-03-01

    Time-delayed feedback control becomes problematic in situations in which the time constant of the system is fast compared to the feedback reaction time. In particular, when perturbations are unpredictable, traditional feedback or feed-forward control schemes can be insufficient. Nonethless a human can balance a stick at their fingertip in the presence of fluctuations that occur on time scales shorter than their neural reaction times. Here we study a simple model of a repulsive delayed random walk and demonstrate that the interplay between noise and delay can transiently stabilize an unstable fixed-point. This observation leads to the concept of ``delayed stochastic control,'' i.e. stabilization of tasks, such as stick balancing at the fingertip, by optimally tuning the noise level with respect to the feedback delay time. References:(1)J.L.Cabrera and J.G.Milton, PRL 89 158702 (2002);(2) T. Ohira and J.G.Milton, PRE 52 3277 (1995);(3)T.Hosaka, T.Ohira, C.Lucian, J.L.Cabrera, and J.G.Milton, Prog. Theor. Phys. (to appear).

  19. Turbulence and Stochastic Processes

    NASA Astrophysics Data System (ADS)

    Celani, Antonio; Mazzino, Andrea; Pumir, Alain

    sec:08-1In 1931 the monograph Analytical Methods in Probability Theory appeared, in which A.N. Kolmogorov laid the foundations for the modern theory of Markov processes [1]. According to Gnedenko: "In the history of probability theory it is difficult to find other works that changed the established points of view and basic trends in research work in such a decisive way". Ten years later, his article on fully developed turbulence provided the framework within which most, if not all, of the subsequent theoretical investigations have been conducted [2] (see e.g. the review by Biferale et al. in this volume [3]. Remarkably, the greatest advances made in the last few years towards a thorough understanding of turbulence developed from the successful marriage between the theory of stochastic processes and the phenomenology of turbulent transport of scalar fields. In this article we will summarize these recent developments which expose the direct link between the intermittency of transported fields and the statistical properties of particle trajectories advected by the turbulent flow (see also [4], and, for a more thorough review, [5]. We also discuss the perspectives of the Lagrangian approach beyond passive scalars, especially for the modeling of hydrodynamic turbulence.

  20. 40 CFR 96.53 - Recordation of NOX allowance allocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE... allocated to an allocation set-aside. (c) Serial numbers for allocated NO X allowances. When allocating...

  1. 40 CFR 96.53 - Recordation of NOX allowance allocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO 2 TRADING PROGRAMS FOR STATE... allocated to an allocation set-aside. (c) Serial numbers for allocated NO X allowances. When allocating...

  2. 45 CFR 402.31 - Determination of allocations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... ASSISTANCE GRANTS State Allocations § 402.31 Determination of allocations. (a) Allocation formula. Allocations will be computed according to a formula using the following factors and weights: (1) 50...

  3. 45 CFR 402.31 - Determination of allocations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... State Allocations § 402.31 Determination of allocations. (a) Allocation formula. Allocations will be computed according to a formula using the following factors and weights: (1) 50 percent based on the...

  4. Age and equity in liver transplantation: An organ allocation model.

    PubMed

    Cucchetti, Alessandro; Ross, Lainie Friedman; Thistlethwaite, J Richard; Vitale, Alessandro; Ravaioli, Matteo; Cescon, Matteo; Ercolani, Giorgio; Burra, Patrizia; Cillo, Umberto; Pinna, Antonio Daniele

    2015-10-01

    A moral liver allocation policy must be fair. We considered a 2-step, 2-principle allocation system called "age mapping." Its first principle, equal opportunity, ensures that candidates of all ages have an equal chance of getting an organ. Its second principle, prudential lifespan equity, allocates younger donor grafts to younger candidates and older donors to older candidates in order to increase the likelihood that all recipients achieve a "full lifespan." Data from 2476 candidates and 1371 consecutive adult liver transplantations (from 1999 to 2012) were used to determine whether age mapping can reduce the gap in years of life lost (YLL) between younger and older recipients. A parametric Weibull prognostic model was developed to estimate total life expectancy after transplantation using survival of the general population matched by sex and age as a reference. Life expectancy from birth was calculated by adding age at transplant and total life expectancy after transplantation. In multivariate analysis, recipient age, hepatitis C virus status, Model for End-Stage Liver Disease score at transplant of >30, and donor age were significantly related to prognosis after surgery (P < 0.05). The mean (and standard deviation) number of years of life from birth, calculated from the current allocation model, for various age groups were: recipients 18-47 years (n = 340) = 65.2 (3.3); 48-55 years (n = 387) = 72.7 (2.1); 56-61 years (n = 372) = 74.7 (1.7) and for recipients >61 years (n = 272) = 77.4 (1.4). The total number of YLL equaled 523 years. Redistributing liver grafts, using an age mapping algorithm, reduces the lifespan gap between younger and older candidates by 33% (from 12.3% to 8.3%) and achieves a 14% overall reduction of YLL (73 years) compared to baseline liver distribution. In conclusion, deliberately incorporating age into an allocation algorithm promotes fairness and increases efficiency.

  5. Using genetic algorithm to solve a new multi-period stochastic optimization model

    NASA Astrophysics Data System (ADS)

    Zhang, Xin-Li; Zhang, Ke-Cun

    2009-09-01

    This paper presents a new asset allocation model based on the CVaR risk measure and transaction costs. Institutional investors manage their strategic asset mix over time to achieve favorable returns subject to various uncertainties, policy and legal constraints, and other requirements. One may use a multi-period portfolio optimization model in order to determine an optimal asset mix. Recently, an alternative stochastic programming model with simulated paths was proposed by Hibiki [N. Hibiki, A hybrid simulation/tree multi-period stochastic programming model for optimal asset allocation, in: H. Takahashi, (Ed.) The Japanese Association of Financial Econometrics and Engineering, JAFFE Journal (2001) 89-119 (in Japanese); N. Hibiki A hybrid simulation/tree stochastic optimization model for dynamic asset allocation, in: B. Scherer (Ed.), Asset and Liability Management Tools: A Handbook for Best Practice, Risk Books, 2003, pp. 269-294], which was called a hybrid model. However, the transaction costs weren't considered in that paper. In this paper, we improve Hibiki's model in the following aspects: (1) The risk measure CVaR is introduced to control the wealth loss risk while maximizing the expected utility; (2) Typical market imperfections such as short sale constraints, proportional transaction costs are considered simultaneously. (3) Applying a genetic algorithm to solve the resulting model is discussed in detail. Numerical results show the suitability and feasibility of our methodology.

  6. Water resources planning and management : A stochastic dual dynamic programming approach

    NASA Astrophysics Data System (ADS)

    Goor, Q.; Pinte, D.; Tilmant, A.

    2008-12-01

    Allocating water between different users and uses, including the environment, is one of the most challenging task facing water resources managers and has always been at the heart of Integrated Water Resources Management (IWRM). As water scarcity is expected to increase over time, allocation decisions among the different uses will have to be found taking into account the complex interactions between water and the economy. Hydro-economic optimization models can capture those interactions while prescribing efficient allocation policies. Many hydro-economic models found in the literature are formulated as large-scale non linear optimization problems (NLP), seeking to maximize net benefits from the system operation while meeting operational and/or institutional constraints, and describing the main hydrological processes. However, those models rarely incorporate the uncertainty inherent to the availability of water, essentially because of the computational difficulties associated stochastic formulations. The purpose of this presentation is to present a stochastic programming model that can identify economically efficient allocation policies in large-scale multipurpose multireservoir systems. The model is based on stochastic dual dynamic programming (SDDP), an extension of traditional SDP that is not affected by the curse of dimensionality. SDDP identify efficient allocation policies while considering the hydrologic uncertainty. The objective function includes the net benefits from the hydropower and irrigation sectors, as well as penalties for not meeting operational and/or institutional constraints. To be able to implement the efficient decomposition scheme that remove the computational burden, the one-stage SDDP problem has to be a linear program. Recent developments improve the representation of the non-linear and mildly non- convex hydropower function through a convex hull approximation of the true hydropower function. This model is illustrated on a cascade of 14

  7. Activation-induced B cell fates are selected by intracellular stochastic competition.

    PubMed

    Duffy, Ken R; Wellard, Cameron J; Markham, John F; Zhou, Jie H S; Holmberg, Ross; Hawkins, Edwin D; Hasbold, Jhagvaral; Dowling, Mark R; Hodgkin, Philip D

    2012-01-20

    In response to stimulation, B lymphocytes pursue a large number of distinct fates important for immune regulation. Whether each cell's fate is determined by external direction, internal stochastic processes, or directed asymmetric division is unknown. Measurement of times to isotype switch, to develop into a plasmablast, and to divide or to die for thousands of cells indicated that each fate is pursued autonomously and stochastically. As a consequence of competition between these processes, censorship of alternative outcomes predicts intricate correlations that are observed in the data. Stochastic competition can explain how the allocation of a proportion of B cells to each cell fate is achieved. The B cell may exemplify how other complex cell differentiation systems are controlled. PMID:22223740

  8. 10 CFR 217.53 - Types of allocation orders.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Types of allocation orders. 217.53 Section 217.53 Energy DEPARTMENT OF ENERGY OIL ENERGY PRIORITIES AND ALLOCATIONS SYSTEM Allocation Actions § 217.53 Types of allocation orders. There are three types of allocation orders available for communicating allocation...

  9. Resource allocation using constraint propagation

    NASA Technical Reports Server (NTRS)

    Rogers, John S.

    1990-01-01

    The concept of constraint propagation was discussed. Performance increases are possible with careful application of these constraint mechanisms. The degree of performance increase is related to the interdependence of the different activities resource usage. Although this method of applying constraints to activities and resources is often beneficial, it is obvious that this is no panacea cure for the computational woes that are experienced by dynamic resource allocation and scheduling problems. A combined effort for execution optimization in all areas of the system during development and the selection of the appropriate development environment is still the best method of producing an efficient system.

  10. A Stochastic Collocation Algorithm for Uncertainty Analysis

    NASA Technical Reports Server (NTRS)

    Mathelin, Lionel; Hussaini, M. Yousuff; Zang, Thomas A. (Technical Monitor)

    2003-01-01

    This report describes a stochastic collocation method to adequately handle a physically intrinsic uncertainty in the variables of a numerical simulation. For instance, while the standard Galerkin approach to Polynomial Chaos requires multi-dimensional summations over the stochastic basis functions, the stochastic collocation method enables to collapse those summations to a one-dimensional summation only. This report furnishes the essential algorithmic details of the new stochastic collocation method and provides as a numerical example the solution of the Riemann problem with the stochastic collocation method used for the discretization of the stochastic parameters.

  11. Constrained Allocation Flux Balance Analysis.

    PubMed

    Mori, Matteo; Hwa, Terence; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-06-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws.

  12. Constrained Allocation Flux Balance Analysis.

    PubMed

    Mori, Matteo; Hwa, Terence; Martin, Olivier C; De Martino, Andrea; Marinari, Enzo

    2016-06-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an "ensemble averaging" procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  13. Constrained Allocation Flux Balance Analysis

    PubMed Central

    Mori, Matteo; Hwa, Terence; Martin, Olivier C.

    2016-01-01

    New experimental results on bacterial growth inspire a novel top-down approach to study cell metabolism, combining mass balance and proteomic constraints to extend and complement Flux Balance Analysis. We introduce here Constrained Allocation Flux Balance Analysis, CAFBA, in which the biosynthetic costs associated to growth are accounted for in an effective way through a single additional genome-wide constraint. Its roots lie in the experimentally observed pattern of proteome allocation for metabolic functions, allowing to bridge regulation and metabolism in a transparent way under the principle of growth-rate maximization. We provide a simple method to solve CAFBA efficiently and propose an “ensemble averaging” procedure to account for unknown protein costs. Applying this approach to modeling E. coli metabolism, we find that, as the growth rate increases, CAFBA solutions cross over from respiratory, growth-yield maximizing states (preferred at slow growth) to fermentative states with carbon overflow (preferred at fast growth). In addition, CAFBA allows for quantitatively accurate predictions on the rate of acetate excretion and growth yield based on only 3 parameters determined by empirical growth laws. PMID:27355325

  14. Enhanced algorithms for stochastic programming

    SciTech Connect

    Krishna, A.S.

    1993-09-01

    In this dissertation, we present some of the recent advances made in solving two-stage stochastic linear programming problems of large size and complexity. Decomposition and sampling are two fundamental components of techniques to solve stochastic optimization problems. We describe improvements to the current techniques in both these areas. We studied different ways of using importance sampling techniques in the context of Stochastic programming, by varying the choice of approximation functions used in this method. We have concluded that approximating the recourse function by a computationally inexpensive piecewise-linear function is highly efficient. This reduced the problem from finding the mean of a computationally expensive functions to finding that of a computationally inexpensive function. Then we implemented various variance reduction techniques to estimate the mean of a piecewise-linear function. This method achieved similar variance reductions in orders of magnitude less time than, when we directly applied variance-reduction techniques directly on the given problem. In solving a stochastic linear program, the expected value problem is usually solved before a stochastic solution and also to speed-up the algorithm by making use of the information obtained from the solution of the expected value problem. We have devised a new decomposition scheme to improve the convergence of this algorithm.

  15. Stochastic models: theory and simulation.

    SciTech Connect

    Field, Richard V., Jr.

    2008-03-01

    Many problems in applied science and engineering involve physical phenomena that behave randomly in time and/or space. Examples are diverse and include turbulent flow over an aircraft wing, Earth climatology, material microstructure, and the financial markets. Mathematical models for these random phenomena are referred to as stochastic processes and/or random fields, and Monte Carlo simulation is the only general-purpose tool for solving problems of this type. The use of Monte Carlo simulation requires methods and algorithms to generate samples of the appropriate stochastic model; these samples then become inputs and/or boundary conditions to established deterministic simulation codes. While numerous algorithms and tools currently exist to generate samples of simple random variables and vectors, no cohesive simulation tool yet exists for generating samples of stochastic processes and/or random fields. There are two objectives of this report. First, we provide some theoretical background on stochastic processes and random fields that can be used to model phenomena that are random in space and/or time. Second, we provide simple algorithms that can be used to generate independent samples of general stochastic models. The theory and simulation of random variables and vectors is also reviewed for completeness.

  16. Improving interdependent networks robustness by adding connectivity links

    NASA Astrophysics Data System (ADS)

    Ji, Xingpei; Wang, Bo; Liu, Dichen; Chen, Guo; Tang, Fei; Wei, Daqian; Tu, Lian

    2016-02-01

    Compared with a single and isolated network, interdependent networks have two types of links: connectivity link and dependency link. This paper aims to improve the robustness of interdependent networks by adding connectivity links. Firstly, interdependent networks failure model and four frequently used link addition strategies are briefly reviewed. Furthermore, by defining inter degree-degree difference, two novel link addition strategies are proposed. Finally, we verify the effectiveness of our proposed link addition strategies by comparing with the current link addition strategies in three different network models. The simulation results show that, given the number of added links, link allocation strategies have great effects on the robustness of interdependent networks, i.e., the double-network link allocation strategy is superior to single-network link allocation strategy. Link addition strategies proposed in this paper excel the current strategies, especially for BA interdependent networks. Moreover, our work can provide guidance on how to allocate limited resources to an existing interdependent networks system and optimize its topology to avoid the potential cascade failures.

  17. What Value "Value Added"?

    ERIC Educational Resources Information Center

    Richards, Andrew

    2015-01-01

    Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…

  18. Nonlinear optimization for stochastic simulations.

    SciTech Connect

    Johnson, Michael M.; Yoshimura, Ann S.; Hough, Patricia Diane; Ammerlahn, Heidi R.

    2003-12-01

    This report describes research targeting development of stochastic optimization algorithms and their application to mission-critical optimization problems in which uncertainty arises. The first section of this report covers the enhancement of the Trust Region Parallel Direct Search (TRPDS) algorithm to address stochastic responses and the incorporation of the algorithm into the OPT++ optimization library. The second section describes the Weapons of Mass Destruction Decision Analysis Center (WMD-DAC) suite of systems analysis tools and motivates the use of stochastic optimization techniques in such non-deterministic simulations. The third section details a batch programming interface designed to facilitate criteria-based or algorithm-driven execution of system-of-system simulations. The fourth section outlines the use of the enhanced OPT++ library and batch execution mechanism to perform systems analysis and technology trade-off studies in the WMD detection and response problem domain.

  19. Stochastic determination of matrix determinants.

    PubMed

    Dorn, Sebastian; Ensslin, Torsten A

    2015-07-01

    Matrix determinants play an important role in data analysis, in particular when Gaussian processes are involved. Due to currently exploding data volumes, linear operations-matrices-acting on the data are often not accessible directly but are only represented indirectly in form of a computer routine. Such a routine implements the transformation a data vector undergoes under matrix multiplication. While efficient probing routines to estimate a matrix's diagonal or trace, based solely on such computationally affordable matrix-vector multiplications, are well known and frequently used in signal inference, there is no stochastic estimate for its determinant. We introduce a probing method for the logarithm of a determinant of a linear operator. Our method rests upon a reformulation of the log-determinant by an integral representation and the transformation of the involved terms into stochastic expressions. This stochastic determinant determination enables large-size applications in Bayesian inference, in particular evidence calculations, model comparison, and posterior determination.

  20. Mechanical autonomous stochastic heat engines

    NASA Astrophysics Data System (ADS)

    Serra-Garcia, Marc; Foehr, Andre; Moleron, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara; . Team

    Stochastic heat engines extract work from the Brownian motion of a set of particles out of equilibrium. So far, experimental demonstrations of stochastic heat engines have required extreme operating conditions or nonautonomous external control systems. In this talk, we will present a simple, purely classical, autonomous stochastic heat engine that uses the well-known tension induced nonlinearity in a string. Our engine operates between two heat baths out of equilibrium, and transfers energy from the hot bath to a work reservoir. This energy transfer occurs even if the work reservoir is at a higher temperature than the hot reservoir. The talk will cover a theoretical investigation and experimental results on a macroscopic setup subject to external noise excitations. This system presents an opportunity for the study of non equilibrium thermodynamics and is an interesting candidate for innovative energy conversion devices.

  1. Principal axes for stochastic dynamics

    NASA Astrophysics Data System (ADS)

    Vasconcelos, V. V.; Raischel, F.; Haase, M.; Peinke, J.; Wächter, M.; Lind, P. G.; Kleinhans, D.

    2011-09-01

    We introduce a general procedure for directly ascertaining how many independent stochastic sources exist in a complex system modeled through a set of coupled Langevin equations of arbitrary dimension. The procedure is based on the computation of the eigenvalues and the corresponding eigenvectors of local diffusion matrices. We demonstrate our algorithm by applying it to two examples of systems showing Hopf bifurcation. We argue that computing the eigenvectors associated to the eigenvalues of the diffusion matrix at local mesh points in the phase space enables one to define vector fields of stochastic eigendirections. In particular, the eigenvector associated to the lowest eigenvalue defines the path of minimum stochastic forcing in phase space, and a transform to a new coordinate system aligned with the eigenvectors can increase the predictability of the system.

  2. 47 CFR 2.105 - United States Table of Frequency Allocations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., rules for the use of the 849-851 MHz band have been added to Part 22—Public Mobile Services (47 CFR part... The Communications Act of 1934, as amended. (b) In the United States, radio spectrum may be allocated.... 6 The radio services are defined in 47 CFR 2.1. (c) Category of services. (1) Any segment of...

  3. Introducing ADS Labs

    NASA Astrophysics Data System (ADS)

    Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.

    2011-05-01

    ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org

  4. An intelligent allocation algorithm for parallel processing

    NASA Technical Reports Server (NTRS)

    Carroll, Chester C.; Homaifar, Abdollah; Ananthram, Kishan G.

    1988-01-01

    The problem of allocating nodes of a program graph to processors in a parallel processing architecture is considered. The algorithm is based on critical path analysis, some allocation heuristics, and the execution granularity of nodes in a program graph. These factors, and the structure of interprocessor communication network, influence the allocation. To achieve realistic estimations of the executive durations of allocations, the algorithm considers the fact that nodes in a program graph have to communicate through varying numbers of tokens. Coarse and fine granularities have been implemented, with interprocessor token-communication duration, varying from zero up to values comparable to the execution durations of individual nodes. The effect on allocation of communication network structures is demonstrated by performing allocations for crossbar (non-blocking) and star (blocking) networks. The algorithm assumes the availability of as many processors as it needs for the optimal allocation of any program graph. Hence, the focus of allocation has been on varying token-communication durations rather than varying the number of processors. The algorithm always utilizes as many processors as necessary for the optimal allocation of any program graph, depending upon granularity and characteristics of the interprocessor communication network.

  5. Computational models and resource allocation for supercomputers

    NASA Technical Reports Server (NTRS)

    Mauney, Jon; Agrawal, Dharma P.; Harcourt, Edwin A.; Choe, Young K.; Kim, Sukil

    1989-01-01

    There are several different architectures used in supercomputers, with differing computational models. These different models present a variety of resource allocation problems that must be solved. The computational needs of a program must be cast in terms of the computational model supported by the supercomputer, and this must be done in a way that makes effective use of the machine's resources. This is the resource allocation problem. The computational models of available supercomputers and the associated resource allocation techniques are surveyed. It is shown that many problems and solutions appear repeatedly in very different computing environments. Some case studies are presented, showing concrete computational models and the allocation strategies used.

  6. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    NASA Astrophysics Data System (ADS)

    Su, Dongxu; Zheng, Rencheng; Nakano, Kimihiko; Cartmell, Matthew P.

    2014-11-01

    Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation.

  7. On square-wave-driven stochastic resonance for energy harvesting in a bistable system

    SciTech Connect

    Su, Dongxu; Zheng, Rencheng; Nakano, Kimihiko; Cartmell, Matthew P

    2014-11-15

    Stochastic resonance is a physical phenomenon through which the throughput of energy within an oscillator excited by a stochastic source can be boosted by adding a small modulating excitation. This study investigates the feasibility of implementing square-wave-driven stochastic resonance to enhance energy harvesting. The motivating hypothesis was that such stochastic resonance can be efficiently realized in a bistable mechanism. However, the condition for the occurrence of stochastic resonance is conventionally defined by the Kramers rate. This definition is inadequate because of the necessity and difficulty in estimating white noise density. A bistable mechanism has been designed using an explicit analytical model which implies a new approach for achieving stochastic resonance in the paper. Experimental tests confirm that the addition of a small-scale force to the bistable system excited by a random signal apparently leads to a corresponding amplification of the response that we now term square-wave-driven stochastic resonance. The study therefore indicates that this approach may be a promising way to improve the performance of an energy harvester under certain forms of random excitation.

  8. Stochastic Simulation of Turing Patterns

    NASA Astrophysics Data System (ADS)

    Fu, Zheng-Ping; Xu, Xin-Hang; Wang, Hong-Li; Ouyang, Qi

    2008-04-01

    We investigate the effects of intrinsic noise on Turing pattern formation near the onset of bifurcation from the homogeneous state to Turing pattern in the reaction-diffusion Brusselator. By performing stochastic simulations of the master equation and using Gillespie's algorithm, we check the spatiotemporal behaviour influenced by internal noises. We demonstrate that the patterns of occurrence frequency for the reaction and diffusion processes are also spatially ordered and temporally stable. Turing patterns are found to be robust against intrinsic fluctuations. Stochastic simulations also reveal that under the influence of intrinsic noises, the onset of Turing instability is advanced in comparison to that predicted deterministically.

  9. QB1 - Stochastic Gene Regulation

    SciTech Connect

    Munsky, Brian

    2012-07-23

    Summaries of this presentation are: (1) Stochastic fluctuations or 'noise' is present in the cell - Random motion and competition between reactants, Low copy, quantization of reactants, Upstream processes; (2) Fluctuations may be very important - Cell-to-cell variability, Cell fate decisions (switches), Signal amplification or damping, stochastic resonances; and (3) Some tools are available to mode these - Kinetic Monte Carlo simulations (SSA and variants), Moment approximation methods, Finite State Projection. We will see how modeling these reactions can tell us more about the underlying processes of gene regulation.

  10. Stochastic Optimization of Complex Systems

    SciTech Connect

    Birge, John R.

    2014-03-20

    This project focused on methodologies for the solution of stochastic optimization problems based on relaxation and penalty methods, Monte Carlo simulation, parallel processing, and inverse optimization. The main results of the project were the development of a convergent method for the solution of models that include expectation constraints as in equilibrium models, improvement of Monte Carlo convergence through the use of a new method of sample batch optimization, the development of new parallel processing methods for stochastic unit commitment models, and the development of improved methods in combination with parallel processing for incorporating automatic differentiation methods into optimization.

  11. Partial ASL extensions for stochastic programming.

    SciTech Connect

    Gay, David

    2010-03-31

    partially completed extensions for stochastic programming to the AMPL/solver interface library (ASL).modeling and experimenting with stochastic recourse problems. This software is not primarily for military applications

  12. Theory, technology, and technique of stochastic cooling

    SciTech Connect

    Marriner, J.

    1993-10-01

    The theory and technological implementation of stochastic cooling is described. Theoretical and technological limitations are discussed. Data from existing stochastic cooling systems are shown to illustrate some useful techniques.

  13. Divergence in plant and microbial allocation strategies explains continental patterns in microbial allocation and biogeochemical fluxes.

    PubMed

    Averill, Colin

    2014-10-01

    Allocation trade-offs shape ecological and biogeochemical phenomena at local to global scale. Plant allocation strategies drive major changes in ecosystem carbon cycling. Microbial allocation to enzymes that decompose carbon vs. organic nutrients may similarly affect ecosystem carbon cycling. Current solutions to this allocation problem prioritise stoichiometric tradeoffs implemented in plant ecology. These solutions may not maximise microbial growth and fitness under all conditions, because organic nutrients are also a significant carbon resource for microbes. I created multiple allocation frameworks and simulated microbial growth using a microbial explicit biogeochemical model. I demonstrate that prioritising stoichiometric trade-offs does not optimise microbial allocation, while exploiting organic nutrients as carbon resources does. Analysis of continental-scale enzyme data supports the allocation patterns predicted by this framework, and modelling suggests large deviations in soil C loss based on which strategy is implemented. Therefore, understanding microbial allocation strategies will likely improve our understanding of carbon cycling and climate.

  14. Constant time worker thread allocation via configuration caching

    DOEpatents

    Eichenberger, Alexandre E; O'Brien, John K. P.

    2014-11-04

    Mechanisms are provided for allocating threads for execution of a parallel region of code. A request for allocation of worker threads to execute the parallel region of code is received from a master thread. Cached thread allocation information identifying prior thread allocations that have been performed for the master thread are accessed. Worker threads are allocated to the master thread based on the cached thread allocation information. The parallel region of code is executed using the allocated worker threads.

  15. Stochastic simulation of karst conduit networks

    NASA Astrophysics Data System (ADS)

    Pardo-Igúzquiza, Eulogio; Dowd, Peter A.; Xu, Chaoshui; Durán-Valsero, Juan José

    2012-01-01

    Karst aquifers have very high spatial heterogeneity. Essentially, they comprise a system of pipes (i.e., the network of conduits) superimposed on rock porosity and on a network of stratigraphic surfaces and fractures. This heterogeneity strongly influences the hydraulic behavior of the karst and it must be reproduced in any realistic numerical model of the karst system that is used as input to flow and transport modeling. However, the directly observed karst conduits are only a small part of the complete karst conduit system and knowledge of the complete conduit geometry and topology remains spatially limited and uncertain. Thus, there is a special interest in the stochastic simulation of networks of conduits that can be combined with fracture and rock porosity models to provide a realistic numerical model of the karst system. Furthermore, the simulated model may be of interest per se and other uses could be envisaged. The purpose of this paper is to present an efficient method for conditional and non-conditional stochastic simulation of karst conduit networks. The method comprises two stages: generation of conduit geometry and generation of topology. The approach adopted is a combination of a resampling method for generating conduit geometries from templates and a modified diffusion-limited aggregation method for generating the network topology. The authors show that the 3D karst conduit networks generated by the proposed method are statistically similar to observed karst conduit networks or to a hypothesized network model. The statistical similarity is in the sense of reproducing the tortuosity index of conduits, the fractal dimension of the network, the direction rose of directions, the Z-histogram and Ripley's K-function of the bifurcation points (which differs from a random allocation of those bifurcation points). The proposed method (1) is very flexible, (2) incorporates any experimental data (conditioning information) and (3) can easily be modified when

  16. The Hamiltonian Mechanics of Stochastic Acceleration

    SciTech Connect

    Burby, J. W.

    2013-07-17

    We show how to nd the physical Langevin equation describing the trajectories of particles un- dergoing collisionless stochastic acceleration. These stochastic di erential equations retain not only one-, but two-particle statistics, and inherit the Hamiltonian nature of the underlying microscopic equations. This opens the door to using stochastic variational integrators to perform simulations of stochastic interactions such as Fermi acceleration. We illustrate the theory by applying it to two example problems.

  17. Transport in a stochastic magnetic field

    SciTech Connect

    White, R.B.; Wu, Yanlin . Plasma Physics Lab.); Rax, J.M. . Dept. de Recherches sur la Fusion Controlee)

    1992-01-01

    Collisional heat transport in a stochastic magnetic field configuration is investigated. Well above stochastic threshold, a numerical solution of a Chirikov-Taylor model shows a short-time nonlocal regime, but at large time the Rechester-Rosenbluth effective diffusion is confirmed. Near stochastic threshold, subdiffusive behavior is observed for short mean free paths. The nature of this subdiffusive behavior is understood in terms of the spectrum of islands in the stochastic sea.

  18. Transport in a stochastic magnetic field

    SciTech Connect

    White, R.B.; Wu, Yanlin; Rax, J.M.

    1992-09-01

    Collisional heat transport in a stochastic magnetic field configuration is investigated. Well above stochastic threshold, a numerical solution of a Chirikov-Taylor model shows a short-time nonlocal regime, but at large time the Rechester-Rosenbluth effective diffusion is confirmed. Near stochastic threshold, subdiffusive behavior is observed for short mean free paths. The nature of this subdiffusive behavior is understood in terms of the spectrum of islands in the stochastic sea.

  19. Optomechanically induced stochastic resonance and chaos transfer between optical fields

    NASA Astrophysics Data System (ADS)

    Monifi, Faraz; Zhang, Jing; Özdemir, Şahin Kaya; Peng, Bo; Liu, Yu-Xi; Bo, Fang; Nori, Franco; Yang, Lan

    2016-06-01

    Chaotic dynamics has been reported in many physical systems and has affected almost every field of science. Chaos involves hypersensitivity to the initial conditions of a system and introduces unpredictability into its output. Thus, it is often unwanted. Interestingly, the very same features make chaos a powerful tool to suppress decoherence, achieve secure communication and replace background noise in stochastic resonance—a counterintuitive concept that a system's ability to transfer information can be coherently amplified by adding noise. Here, we report the first demonstration of chaos-induced stochastic resonance in an optomechanical system, as well as the optomechanically mediated chaos transfer between two optical fields such that they follow the same route to chaos. These results will contribute to the understanding of nonlinear phenomena and chaos in optomechanical systems, and may find applications in the chaotic transfer of information and for improving the detection of otherwise undetectable signals in optomechanical systems.

  20. A new model for realistic random perturbations of stochastic oscillators

    NASA Astrophysics Data System (ADS)

    Dieci, Luca; Li, Wuchen; Zhou, Haomin

    2016-08-01

    Classical theories predict that solutions of differential equations will leave any neighborhood of a stable limit cycle, if white noise is added to the system. In reality, many engineering systems modeled by second order differential equations, like the van der Pol oscillator, show incredible robustness against noise perturbations, and the perturbed trajectories remain in the neighborhood of a stable limit cycle for all times of practical interest. In this paper, we propose a new model of noise to bridge this apparent discrepancy between theory and practice. Restricting to perturbations from within this new class of noise, we consider stochastic perturbations of second order differential systems that -in the unperturbed case- admit asymptotically stable limit cycles. We show that the perturbed solutions are globally bounded and remain in a tubular neighborhood of the underlying deterministic periodic orbit. We also define stochastic Poincaré map(s), and further derive partial differential equations for the transition density function.

  1. A stochastic analysis approach for the calculation of hydrodynamic dampings

    SciTech Connect

    Karadeniz, H.

    1995-12-31

    This paper introduces an alternative linearization algorithm for nonlinear loading terms occurring in the spectral analysis of offshore structures. The algorithm makes use of member consistent forces for the linearization unlike the traditional linearization method. Different linearization criteria are used for different components of the member consistent forces. An equivalent second moment criterion is used to linearize the force component due to wave velocities while the components due to current and structural velocities are kept being stochastic. Calculation of their mean values is presented for the analysis. A deterministic added mass matrix and a stochastic hydrodynamic damping matrix are derived from the force component due to structural deformations. It is demonstrated that the mean value hydrodynamic damping ratios which are calculated in the paper are more realistic than those resulted from the linearization of the Morison`s equation.

  2. Stochastic architecture for Hopfield neural nets

    NASA Technical Reports Server (NTRS)

    Pavel, Sandy

    1992-01-01

    An expandable stochastic digital architecture for recurrent (Hopfield like) neural networks is proposed. The main features and basic principles of stochastic processing are presented. The stochastic digital architecture is based on a chip with n full interconnected neurons with a pipeline, bit processing structure. For large applications, a flexible way to interconnect many such chips is provided.

  3. Stochasticity, succession, and environmental perturbations in a fluidic ecosystem

    PubMed Central

    Zhou, Jizhong; Deng, Ye; Zhang, Ping; Xue, Kai; Liang, Yuting; Van Nostrand, Joy D.; Yang, Yunfeng; He, Zhili; Wu, Liyou; Stahl, David A.; Hazen, Terry C.; Tiedje, James M.; Arkin, Adam P.

    2014-01-01

    Unraveling the drivers of community structure and succession in response to environmental change is a central goal in ecology. Although the mechanisms shaping community structure have been intensively examined, those controlling ecological succession remain elusive. To understand the relative importance of stochastic and deterministic processes in mediating microbial community succession, a unique framework composed of four different cases was developed for fluidic and nonfluidic ecosystems. The framework was then tested for one fluidic ecosystem: a groundwater system perturbed by adding emulsified vegetable oil (EVO) for uranium immobilization. Our results revealed that groundwater microbial community diverged substantially away from the initial community after EVO amendment and eventually converged to a new community state, which was closely clustered with its initial state. However, their composition and structure were significantly different from each other. Null model analysis indicated that both deterministic and stochastic processes played important roles in controlling the assembly and succession of the groundwater microbial community, but their relative importance was time dependent. Additionally, consistent with the proposed conceptual framework but contradictory to conventional wisdom, the community succession responding to EVO amendment was primarily controlled by stochastic rather than deterministic processes. During the middle phase of the succession, the roles of stochastic processes in controlling community composition increased substantially, ranging from 81.3% to 92.0%. Finally, there are limited successional studies available to support different cases in the conceptual framework, but further well-replicated explicit time-series experiments are needed to understand the relative importance of deterministic and stochastic processes in controlling community succession. PMID:24550501

  4. Stochasticity, succession, and environmental perturbations in a fluidic ecosystem.

    PubMed

    Zhou, Jizhong; Deng, Ye; Zhang, Ping; Xue, Kai; Liang, Yuting; Van Nostrand, Joy D; Yang, Yunfeng; He, Zhili; Wu, Liyou; Stahl, David A; Hazen, Terry C; Tiedje, James M; Arkin, Adam P

    2014-03-01

    Unraveling the drivers of community structure and succession in response to environmental change is a central goal in ecology. Although the mechanisms shaping community structure have been intensively examined, those controlling ecological succession remain elusive. To understand the relative importance of stochastic and deterministic processes in mediating microbial community succession, a unique framework composed of four different cases was developed for fluidic and nonfluidic ecosystems. The framework was then tested for one fluidic ecosystem: a groundwater system perturbed by adding emulsified vegetable oil (EVO) for uranium immobilization. Our results revealed that groundwater microbial community diverged substantially away from the initial community after EVO amendment and eventually converged to a new community state, which was closely clustered with its initial state. However, their composition and structure were significantly different from each other. Null model analysis indicated that both deterministic and stochastic processes played important roles in controlling the assembly and succession of the groundwater microbial community, but their relative importance was time dependent. Additionally, consistent with the proposed conceptual framework but contradictory to conventional wisdom, the community succession responding to EVO amendment was primarily controlled by stochastic rather than deterministic processes. During the middle phase of the succession, the roles of stochastic processes in controlling community composition increased substantially, ranging from 81.3% to 92.0%. Finally, there are limited successional studies available to support different cases in the conceptual framework, but further well-replicated explicit time-series experiments are needed to understand the relative importance of deterministic and stochastic processes in controlling community succession.

  5. Allocation Variable-Based Probabilistic Algorithm to Deal with Label Switching Problem in Bayesian Mixture Models

    PubMed Central

    Pan, Jia-Chiun; Liu, Chih-Min; Hwu, Hai-Gwo; Huang, Guan-Hua

    2015-01-01

    The label switching problem occurs as a result of the nonidentifiability of posterior distribution over various permutations of component labels when using Bayesian approach to estimate parameters in mixture models. In the cases where the number of components is fixed and known, we propose a relabelling algorithm, an allocation variable-based (denoted by AVP) probabilistic relabelling approach, to deal with label switching problem. We establish a model for the posterior distribution of allocation variables with label switching phenomenon. The AVP algorithm stochastically relabel the posterior samples according to the posterior probabilities of the established model. Some existing deterministic and other probabilistic algorithms are compared with AVP algorithm in simulation studies, and the success of the proposed approach is demonstrated in simulation studies and a real dataset. PMID:26458185

  6. Promotion of cooperation induced by nonuniform payoff allocation in spatial public goods game

    NASA Astrophysics Data System (ADS)

    Peng, D.; Yang, H.-X.; Wang, W.-X.; Chen, G. R.; Wang, B.-H.

    2010-02-01

    A nonuniform payoff allocation mechanism is proposed for spatial public goods games where individuals are nodes on a scale-free network. Each individual is assigned a weight ki α, where ki is the degree of individual i and α is an adjustable parameter that controls the degree of diversity in individuals’ profits. During the evolution progress, the allocation of payoff on individual i is assumed to be proportional to its weight. Individuals synchronously update their strategies according to the stochastic rule with a fixed noise level. It is found that there exists an optimal value of α which yields the highest level of cooperation. Other pertinent quantities, including the payoff and the probability of finding a node playing as cooperator versus the degree, are also investigated computationally and analytically. Our results suggest that a suitable degree of diversity among individuals can promote the emergence of cooperation.

  7. The stochastic dance of early HIV infection

    NASA Astrophysics Data System (ADS)

    Merrill, Stephen J.

    2005-12-01

    The stochastic nature of early HIV infection is described in a series of models, each of which captures aspects of the dance of HIV during the early stages of infection. It is to this highly variable target that the immune response must respond. The adaptability of the various components of the immune response is an important aspect of the system's operation, as the nature of the pathogens that the response will be required to respond to and the order in which those responses must be made cannot be known beforehand. As HIV infection has direct influence over cells responsible for the immune response, the dance predicts that the immune response will be also in a variable state of readiness and capability for this task of adaptation. The description of the stochastic dance of HIV here will use the tools of stochastic models, and for the most part, simulation. The justification for this approach is that the early stages and the development of HIV diversity require that the model to be able to describe both individual sample path and patient-to-patient variability. In addition, as early viral dynamics are best described using branching processes, the explosive growth of these models both predicts high variability and rapid response of HIV to changes in system parameters.In this paper, a basic viral growth model based on a time dependent continuous-time branching process is used to describe the growth of HIV infected cells in the macrophage and lymphocyte populations. Immigration from the reservoir population is added to the basic model to describe the incubation time distribution. This distribution is deduced directly from the modeling assumptions and the model of viral growth. A system of two branching processes, one in the infected macrophage population and one in the infected lymphocyte population is used to provide a description of the relationship between the development of HIV diversity as it relates to tropism (host cell preference). The role of the immune

  8. Stochastic-field cavitation model

    NASA Astrophysics Data System (ADS)

    Dumond, J.; Magagnato, F.; Class, A.

    2013-07-01

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian "particles" or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

  9. Stochastic-field cavitation model

    SciTech Connect

    Dumond, J.; Magagnato, F.; Class, A.

    2013-07-15

    Nonlinear phenomena can often be well described using probability density functions (pdf) and pdf transport models. Traditionally, the simulation of pdf transport requires Monte-Carlo codes based on Lagrangian “particles” or prescribed pdf assumptions including binning techniques. Recently, in the field of combustion, a novel formulation called the stochastic-field method solving pdf transport based on Eulerian fields has been proposed which eliminates the necessity to mix Eulerian and Lagrangian techniques or prescribed pdf assumptions. In the present work, for the first time the stochastic-field method is applied to multi-phase flow and, in particular, to cavitating flow. To validate the proposed stochastic-field cavitation model, two applications are considered. First, sheet cavitation is simulated in a Venturi-type nozzle. The second application is an innovative fluidic diode which exhibits coolant flashing. Agreement with experimental results is obtained for both applications with a fixed set of model constants. The stochastic-field cavitation model captures the wide range of pdf shapes present at different locations.

  10. Stochastic resonance on a circle

    SciTech Connect

    Wiesenfeld, K. ); Pierson, D.; Pantazelou, E.; Dames, C.; Moss, F. )

    1994-04-04

    We describe a new realization of stochastic resonance, applicable to a broad class of systems, based on an underlying excitable dynamics with deterministic reinjection. A simple but general theory of such single-trigger'' systems is compared with analog simulations of the Fitzhugh-Nagumo model, as well as experimental data obtained from stimulated sensory neurons in the crayfish.

  11. Universality in Stochastic Exponential Growth

    NASA Astrophysics Data System (ADS)

    Iyer-Biswas, Srividya; Crooks, Gavin E.; Scherer, Norbert F.; Dinner, Aaron R.

    2014-07-01

    Recent imaging data for single bacterial cells reveal that their mean sizes grow exponentially in time and that their size distributions collapse to a single curve when rescaled by their means. An analogous result holds for the division-time distributions. A model is needed to delineate the minimal requirements for these scaling behaviors. We formulate a microscopic theory of stochastic exponential growth as a Master Equation that accounts for these observations, in contrast to existing quantitative models of stochastic exponential growth (e.g., the Black-Scholes equation or geometric Brownian motion). Our model, the stochastic Hinshelwood cycle (SHC), is an autocatalytic reaction cycle in which each molecular species catalyzes the production of the next. By finding exact analytical solutions to the SHC and the corresponding first passage time problem, we uncover universal signatures of fluctuations in exponential growth and division. The model makes minimal assumptions, and we describe how more complex reaction networks can reduce to such a cycle. We thus expect similar scalings to be discovered in stochastic processes resulting in exponential growth that appear in diverse contexts such as cosmology, finance, technology, and population growth.

  12. How to Do Random Allocation (Randomization)

    PubMed Central

    Shin, Wonshik

    2014-01-01

    Purpose To explain the concept and procedure of random allocation as used in a randomized controlled study. Methods We explain the general concept of random allocation and demonstrate how to perform the procedure easily and how to report it in a paper. PMID:24605197

  13. 10 CFR 490.503 - Credit allocation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle... described in section 490.507 of this part, DOE shall allocate one credit for each alternative fueled...

  14. 10 CFR 490.503 - Credit allocation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle... described in section 490.507 of this part, DOE shall allocate one credit for each alternative fueled...

  15. 10 CFR 490.503 - Credit allocation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle... described in section 490.507 of this part, DOE shall allocate one credit for each alternative fueled...

  16. 10 CFR 490.503 - Credit allocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle... described in section 490.507 of this part, DOE shall allocate one credit for each alternative fueled...

  17. 10 CFR 490.503 - Credit allocation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Credit allocation. 490.503 Section 490.503 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Alternative Fueled Vehicle... described in section 490.507 of this part, DOE shall allocate one credit for each alternative fueled...

  18. Thematic Mapper data for forest resource allocation

    NASA Technical Reports Server (NTRS)

    Zeff, Ilene S.; Merry, Carolyn J.

    1993-01-01

    A technique for classifying a Landsat Thematic Mapper image was demonstrated on the Wayne National Forest of southeastern Ohio. The classified image was integrated into a geographic information system database, and prescriptive forest land use allocation models were developed using the techniques of cartographic modeling. Timber harvest sites and accompanying haul roads were allocated.

  19. 42 CFR 24.2 - Allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2 Allocation. (a) The Secretary, within the number authorized in the PHS Act, shall determine...

  20. 42 CFR 24.2 - Allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2 Allocation. (a) The Secretary, within the number authorized in the PHS Act, shall determine...

  1. 42 CFR 24.2 - Allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2 Allocation. (a) The Secretary, within the number authorized in the PHS Act, shall determine...

  2. 42 CFR 24.2 - Allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2 Allocation. (a) The Secretary, within the number authorized in the PHS Act, shall determine...

  3. 42 CFR 24.2 - Allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Allocation. 24.2 Section 24.2 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES PERSONNEL SENIOR BIOMEDICAL RESEARCH SERVICE § 24.2 Allocation. (a) The Secretary, within the number authorized in the PHS Act, shall determine...

  4. 45 CFR 304.15 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... FEDERAL FINANCIAL PARTICIPATION § 304.15 Cost allocation. A State agency in support of its claims under title IV-D of the Social Security Act must have an approved cost allocation plan on file with the Department in accordance with the requirements contained in Subpart E of 45 CFR part 95. Subpart E also...

  5. 45 CFR 304.15 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... FEDERAL FINANCIAL PARTICIPATION § 304.15 Cost allocation. A State agency in support of its claims under title IV-D of the Social Security Act must have an approved cost allocation plan on file with the Department in accordance with the requirements contained in Subpart E of 45 CFR part 95. Subpart E also...

  6. Resource Allocation in Classrooms. Final Report.

    ERIC Educational Resources Information Center

    Thomas, J. Alan

    This report deals with the allocation of resources within classrooms and homes. It is based on the assumption that learning occurs through a set of processes that require the utilization of human and material resources. It is assumed that the study of resource allocation at the micro level will help provide an understanding of the effect on…

  7. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 1 2013-10-01 2013-10-01 false Cost allocation. 98.55 Section 98.55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and...

  8. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 1 2012-10-01 2012-10-01 false Cost allocation. 98.55 Section 98.55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and...

  9. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 1 2014-10-01 2014-10-01 false Cost allocation. 98.55 Section 98.55 Public Welfare Department of Health and Human Services GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and...

  10. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Cost allocation. 98.55 Section 98.55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and...

  11. 45 CFR 98.55 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Cost allocation. 98.55 Section 98.55 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION CHILD CARE AND DEVELOPMENT FUND Use of Child Care and Development Funds § 98.55 Cost allocation. (a) The Lead Agency and...

  12. 50 CFR 600.517 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Allocations. 600.517 Section 600.517 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MAGNUSON-STEVENS ACT PROVISIONS Foreign Fishing § 600.517 Allocations. The...

  13. 24 CFR 594.15 - Allocation amounts.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Allocation amounts. 594.15 Section... § 594.15 Allocation amounts. (a) Amounts and match requirement. HUD will make grants, in the form of... for less than the maximum amount established by statute, and to limit the number of times a...

  14. 45 CFR 304.15 - Cost allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Welfare Regulations Relating to Public Welfare OFFICE OF CHILD SUPPORT ENFORCEMENT (CHILD SUPPORT... FEDERAL FINANCIAL PARTICIPATION § 304.15 Cost allocation. A State agency in support of its claims under title IV-D of the Social Security Act must have an approved cost allocation plan on file with...

  15. Acquisitions Allocations: Fairness, Equity and Bundled Pricing.

    ERIC Educational Resources Information Center

    Packer, Donna

    2001-01-01

    Examined the effect of an interdisciplinary Web-based citation database with full text, the ProQuest Research Library, on the Western State University library's acquisitions allocation plan. Used list price of full-text journals to calculate increases in acquisitions funding. A list of articles discussing formula allocation is appended.…

  16. 50 CFR 660.55 - Allocations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... PCGFMP. Allocation of black rockfish is described in paragraph (l) of this section. Allocation of Pacific... RF North of 40°10′ N. lat. 81 18 Minor Slope RF South of 40°10′ N. lat. 63 37 Dover Sole 95 5 English... through the biennial harvest specifications and management measures process. (k) (l) Black...

  17. 50 CFR 660.55 - Allocations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... PCGFMP. Allocation of black rockfish is described in paragraph (l) of this section. Allocation of Pacific... RF North of 40°10′ N. lat. 81 18 Minor Slope RF South of 40°10′ N. lat. 63 37 Dover Sole 95 5 English... through the biennial harvest specifications and management measures process. (k) (l) Black...

  18. 50 CFR 660.55 - Allocations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... PCGFMP. Allocation of black rockfish is described in paragraph (l) of this section. Allocation of Pacific... Dover Sole 95 5 English Sole 95 5 Petrale Sole 95 5 Arrowtooth Flounder 95 5 Starry Flounder 50 50 Other... measures process. (l) Black rockfish harvest guideline. The commercial tribal harvest guideline for...

  19. 44 CFR 304.4 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Allocations. 304.4 Section 304.4 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY PREPAREDNESS CONSOLIDATED GRANTS TO INSULAR AREAS § 304.4 Allocations. For each Federal...

  20. 23 CFR 660.107 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Allocations. 660.107 Section 660.107 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS SPECIAL PROGRAMS (DIRECT FEDERAL) Forest Highways § 660.107 Allocations. On October 1 of each fiscal year, the FHWA...

  1. 15 CFR 336.4 - Allocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 2 2010-01-01 2010-01-01 false Allocation. 336.4 Section 336.4 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued) INTERNATIONAL... § 336.4 Allocation. (a) The Tariff Rate Quota licenses will be issued to eligible manufacturers on...

  2. 48 CFR 5452.249 - Allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 7 2014-10-01 2014-10-01 false Allocation. 5452.249 Section 5452.249 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 5452.249 Allocation. The...

  3. 48 CFR 5452.249 - Allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 7 2012-10-01 2012-10-01 false Allocation. 5452.249 Section 5452.249 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 5452.249 Allocation. The...

  4. 48 CFR 5452.249 - Allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 7 2011-10-01 2011-10-01 false Allocation. 5452.249 Section 5452.249 Federal Acquisition Regulations System DEFENSE LOGISTICS AGENCY, DEPARTMENT OF DEFENSE SOLICITATION PROVISIONS AND CONTRACT CLAUSES Texts of Provisions and Clauses 5452.249 Allocation. The...

  5. 45 CFR 205.150 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... ASSISTANCE PROGRAMS § 205.150 Cost allocation. A State plan under title I, IV-A, X, XIV, or XVI (AABD) of the Social Security Act must provide that the State agency will have an approved cost allocation plan on file with the Department in accordance with the requirements contained in subpart E of 45 CFR part...

  6. Resource Allocation in Public Research Universities

    ERIC Educational Resources Information Center

    Santos, Jose L.

    2007-01-01

    The purpose of this study was to conduct an econometric analysis of internal resource allocation. Two theories are used for this study of resource allocation in public research universities, and these are: (1) Theory of the Firm; and (2) Resource Dependence Theory. This study used the American Association of Universities Data Exchange (AAUDE)…

  7. 42 CFR 457.228 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accordance with the requirements contained in subpart E of 45 CFR part 95. Subpart E also sets forth the... 42 Public Health 4 2011-10-01 2011-10-01 false Cost allocation. 457.228 Section 457.228 Public...; Reduction of Federal Medical Payments § 457.228 Cost allocation. A State plan must provide that the...

  8. 42 CFR 433.34 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Department in accordance with the requirements contained in subpart E of 45 CFR part 95. Subpart E also sets... 42 Public Health 4 2011-10-01 2011-10-01 false Cost allocation. 433.34 Section 433.34 Public... Provisions § 433.34 Cost allocation. A State plan under Title XIX of the Social Security Act must...

  9. Rethinking Reinforcement: Allocation, Induction, and Contingency

    ERIC Educational Resources Information Center

    Baum, William M.

    2012-01-01

    The concept of reinforcement is at least incomplete and almost certainly incorrect. An alternative way of organizing our understanding of behavior may be built around three concepts: "allocation," "induction," and "correlation." Allocation is the measure of behavior and captures the centrality of choice: All behavior entails choice and consists of…

  10. Two Virasoro symmetries in stringy warped AdS3

    NASA Astrophysics Data System (ADS)

    Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.

    2014-12-01

    We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.

  11. Algorithmic advances in stochastic programming

    SciTech Connect

    Morton, D.P.

    1993-07-01

    Practical planning problems with deterministic forecasts of inherently uncertain parameters often yield unsatisfactory solutions. Stochastic programming formulations allow uncertain parameters to be modeled as random variables with known distributions, but the size of the resulting mathematical programs can be formidable. Decomposition-based algorithms take advantage of special structure and provide an attractive approach to such problems. We consider two classes of decomposition-based stochastic programming algorithms. The first type of algorithm addresses problems with a ``manageable`` number of scenarios. The second class incorporates Monte Carlo sampling within a decomposition algorithm. We develop and empirically study an enhanced Benders decomposition algorithm for solving multistage stochastic linear programs within a prespecified tolerance. The enhancements include warm start basis selection, preliminary cut generation, the multicut procedure, and decision tree traversing strategies. Computational results are presented for a collection of ``real-world`` multistage stochastic hydroelectric scheduling problems. Recently, there has been an increased focus on decomposition-based algorithms that use sampling within the optimization framework. These approaches hold much promise for solving stochastic programs with many scenarios. A critical component of such algorithms is a stopping criterion to ensure the quality of the solution. With this as motivation, we develop a stopping rule theory for algorithms in which bounds on the optimal objective function value are estimated by sampling. Rules are provided for selecting sample sizes and terminating the algorithm under which asymptotic validity of confidence interval statements for the quality of the proposed solution can be verified. Issues associated with the application of this theory to two sampling-based algorithms are considered, and preliminary empirical coverage results are presented.

  12. Numerical considerations for Lagrangian stochastic dispersion models: Eliminating rogue trajectories, and the importance of numerical accuracy

    Technology Transfer Automated Retrieval System (TEKTRAN)

    When Lagrangian stochastic models for turbulent dispersion are applied to complex flows, some type of ad hoc intervention is almost always necessary to eliminate unphysical behavior in the numerical solution. This paper discusses numerical considerations when solving the Langevin-based particle velo...

  13. Camera scheduling and energy allocation for lifetime maximization in user-centric visual sensor networks.

    PubMed

    Yu, Chao; Sharma, Gaurav

    2010-08-01

    We explore camera scheduling and energy allocation strategies for lifetime optimization in image sensor networks. For the application scenarios that we consider, visual coverage over a monitored region is obtained by deploying wireless, battery-powered image sensors. Each sensor camera provides coverage over a part of the monitored region and a central processor coordinates the sensors in order to gather required visual data. For the purpose of maximizing the network operational lifetime, we consider two problems in this setting: a) camera scheduling, i.e., the selection, among available possibilities, of a set of cameras providing the desired coverage at each time instance, and b) energy allocation, i.e., the distribution of total available energy between the camera sensor nodes. We model the network lifetime as a stochastic random variable that depends upon the coverage geometry for the sensors and the distribution of data requests over the monitored region, two key characteristics that distinguish our problem from other wireless sensor network applications. By suitably abstracting this model of network lifetime and utilizing asymptotic analysis, we propose lifetime-maximizing camera scheduling and energy allocation strategies. The effectiveness of the proposed camera scheduling and energy allocation strategies is validated by simulations. PMID:20350857

  14. Optimal dynamic water allocation: Irrigation extractions and environmental tradeoffs in the Murray River, Australia

    NASA Astrophysics Data System (ADS)

    Grafton, R. Quentin; Chu, Hoang Long; Stewardson, Michael; Kompas, Tom

    2011-12-01

    A key challenge in managing semiarid basins, such as in the Murray-Darling in Australia, is to balance the trade-offs between the net benefits of allocating water for irrigated agriculture, and other uses, versus the costs of reduced surface flows for the environment. Typically, water planners do not have the tools to optimally and dynamically allocate water among competing uses. We address this problem by developing a general stochastic, dynamic programming model with four state variables (the drought status, the current weather, weather correlation, and current storage) and two controls (environmental release and irrigation allocation) to optimally allocate water between extractions and in situ uses. The model is calibrated to Australia's Murray River that generates: (1) a robust qualitative result that "pulse" or artificial flood events are an optimal way to deliver environmental flows over and above conveyance of base flows; (2) from 2001 to 2009 a water reallocation that would have given less to irrigated agriculture and more to environmental flows would have generated between half a billion and over 3 billion U.S. dollars in overall economic benefits; and (3) water markets increase optimal environmental releases by reducing the losses associated with reduced water diversions.

  15. 49 CFR 33.53 - Types of allocation orders.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Allocation Actions § 33.53 Types of allocation orders. There are three types of allocation orders available for communicating allocation actions. These are: (a) Set-aside: An official action that requires a... 49 Transportation 1 2013-10-01 2013-10-01 false Types of allocation orders. 33.53 Section...

  16. 7 CFR 761.205 - Computing the formula allocation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Computing the formula allocation. 761.205 Section 761... Funds to State Offices § 761.205 Computing the formula allocation. (a) The formula allocation for FO, CL... program that the National Office allocates to a State Office. formula allocation = (amount available...

  17. Leading Change, Adding Value.

    PubMed

    Evans, Nick

    2016-09-12

    Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573

  18. 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.

  19. Evaluation of municipal water supply operating rules using stochastic dominance

    NASA Astrophysics Data System (ADS)

    Su, Ming-Daw; Narayanan, Rangesan; Hughes, Trevor C.; Bishop, A. Bruce

    1991-07-01

    A procedure for evaluating and selecting among alternative rules for operating a municipal water supply system is outlined in this study. It is assumed that monthly water demands and supplies are random. The total cost, however, is affected by both current month and future water allocation decisions with respect to the operation of facilities. A perfect foresight model using mixed integer programming is developed and applied to 36 years of historical demand and supply data. Using the solutions to this model, several simple operating rules are derived. These rules are applied to the historical data to simulate system operation, and cumulative distribution of net revenue for each rule is derived. Based on first- and second-degree stochastic dominance criteria, the performance of alternative rules are evaluated. The procedure is also repeated with a set of generated data sequences to check the consistency of the solutions. Average reductions of up to 11% in annual net revenues from those of a perfect foresight model are observed, for various operating rules. Using stochastically dominant rules, annual revenues can be increased by 5% on the average from a commonly used rule based on unit cost.

  20. Nonlinear realization of local symmetries of AdS space

    SciTech Connect

    Clark, T.E.; Love, S.T.; Nitta, Muneto; Veldhuis, T. ter

    2005-10-15

    Coset methods are used to construct the action describing the dynamics associated with the spontaneous breaking of the local symmetries of AdS{sub d+1} space due to the embedding of an AdS{sub d} brane. The resulting action is an SO(2,d) invariant AdS form of the Einstein-Hilbert action, which in addition to the AdS{sub d} gravitational vielbein, also includes a massive vector field localized on the brane. Its long wavelength dynamics is the same as a massive Abelian vector field coupled to gravity in AdS{sub d} space.

  1. Shift-invariant target in allocation problems.

    PubMed

    Mandal, Saumen; Biswas, Atanu

    2014-07-10

    We provide a template for finding target allocation proportions in optimal allocation designs where the target will be invariant for both shifts in location and scale of the response distributions. One possible application of such target allocation proportions is to carry out a response-adaptive allocation. While most of the existing designs are invariant for any change in scale of the underlying distributions, they are not location invariant in most of the cases. First, we indicate this serious flaw in the existing literature and illustrate how this lack of location invariance makes the performance of the designs very poor in terms of allocation for any drastic change in location, such as the changes from degrees centigrade to degrees Fahrenheit. We illustrate that unless a target allocation is location invariant, it might lead to a completely irrelevant and useless target for allocation. Then we discuss how such location invariance can be achieved for general continuous responses. We illustrate the proposed method using some real clinical trial data. We also indicate the possible extension of the procedure for more than two treatments at hand and in the presence of covariates.

  2. 47 CFR 76.924 - Allocation to service cost categories.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... allocator has been specified by the Commission are to be allocated among the service cost categories and the... analysis is not possible, common costs for which no allocator has been specified by the Commission...

  3. 47 CFR 76.924 - Allocation to service cost categories.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... allocator has been specified by the Commission are to be allocated among the service cost categories and the... analysis is not possible, common costs for which no allocator has been specified by the Commission...

  4. 47 CFR 76.924 - Allocation to service cost categories.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... allocator has been specified by the Commission are to be allocated among the service cost categories and the... analysis is not possible, common costs for which no allocator has been specified by the Commission...

  5. Stochastic models of population extinction.

    PubMed

    Ovaskainen, Otso; Meerson, Baruch

    2010-11-01

    Theoretical ecologists have long sought to understand how the persistence of populations depends on biotic and abiotic factors. Classical work showed that demographic stochasticity causes the mean time to extinction to increase exponentially with population size, whereas variation in environmental conditions can lead to a power-law scaling. Recent work has focused especially on the influence of the autocorrelation structure ('color') of environmental noise. In theoretical physics, there is a burst of research activity in analyzing large fluctuations in stochastic population dynamics. This research provides powerful tools for determining extinction times and characterizing the pathway to extinction. It yields, therefore, sharp insights into extinction processes and has great potential for further applications in theoretical biology.

  6. Stochastic Aspects of Cardiac Arrhythmias

    NASA Astrophysics Data System (ADS)

    Lerma, Claudia; Krogh-Madsen, Trine; Guevara, Michael; Glass, Leon

    2007-07-01

    Abnormal cardiac rhythms (cardiac arrhythmias) often display complex changes over time that can have a random or haphazard appearance. Mathematically, these changes can on occasion be identified with bifurcations in difference or differential equation models of the arrhythmias. One source for the variability of these rhythms is the fluctuating environment. However, in the neighborhood of bifurcation points, the fluctuations induced by the stochastic opening and closing of individual ion channels in the cell membrane, which results in membrane noise, may lead to randomness in the observed dynamics. To illustrate this, we consider the effects of stochastic properties of ion channels on the resetting of pacemaker oscillations and on the generation of early afterdepolarizations. The comparison of the statistical properties of long records showing arrhythmias with the predictions from theoretical models should help in the identification of different mechanisms underlying cardiac arrhythmias.

  7. Stochastic kinetic mean field model

    NASA Astrophysics Data System (ADS)

    Erdélyi, Zoltán; Pasichnyy, Mykola; Bezpalchuk, Volodymyr; Tomán, János J.; Gajdics, Bence; Gusak, Andriy M.

    2016-07-01

    This paper introduces a new model for calculating the change in time of three-dimensional atomic configurations. The model is based on the kinetic mean field (KMF) approach, however we have transformed that model into a stochastic approach by introducing dynamic Langevin noise. The result is a stochastic kinetic mean field model (SKMF) which produces results similar to the lattice kinetic Monte Carlo (KMC). SKMF is, however, far more cost-effective and easier to implement the algorithm (open source program code is provided on http://skmf.eu website). We will show that the result of one SKMF run may correspond to the average of several KMC runs. The number of KMC runs is inversely proportional to the amplitude square of the noise in SKMF. This makes SKMF an ideal tool also for statistical purposes.

  8. Wavelet entropy of stochastic processes

    NASA Astrophysics Data System (ADS)

    Zunino, L.; Pérez, D. G.; Garavaglia, M.; Rosso, O. A.

    2007-06-01

    We compare two different definitions for the wavelet entropy associated to stochastic processes. The first one, the normalized total wavelet entropy (NTWS) family [S. Blanco, A. Figliola, R.Q. Quiroga, O.A. Rosso, E. Serrano, Time-frequency analysis of electroencephalogram series, III. Wavelet packets and information cost function, Phys. Rev. E 57 (1998) 932-940; O.A. Rosso, S. Blanco, J. Yordanova, V. Kolev, A. Figliola, M. Schürmann, E. Başar, Wavelet entropy: a new tool for analysis of short duration brain electrical signals, J. Neurosci. Method 105 (2001) 65-75] and a second introduced by Tavares and Lucena [Physica A 357(1) (2005) 71-78]. In order to understand their advantages and disadvantages, exact results obtained for fractional Gaussian noise ( -1<α< 1) and fractional Brownian motion ( 1<α< 3) are assessed. We find out that the NTWS family performs better as a characterization method for these stochastic processes.

  9. Stochastic scanning multiphoton multifocal microscopy.

    PubMed

    Jureller, Justin E; Kim, Hee Y; Scherer, Norbert F

    2006-04-17

    Multiparticle tracking with scanning confocal and multiphoton fluorescence imaging is increasingly important for elucidating biological function, as in the transport of intracellular cargo-carrying vesicles. We demonstrate a simple rapid-sampling stochastic scanning multifocal multiphoton microscopy (SS-MMM) fluorescence imaging technique that enables multiparticle tracking without specialized hardware at rates 1,000 times greater than conventional single point raster scanning. Stochastic scanning of a diffractive optic generated 10x10 hexagonal array of foci with a white noise driven galvanometer yields a scan pattern that is random yet space-filling. SS-MMM creates a more uniformly sampled image with fewer spatio-temporal artifacts than obtained by conventional or multibeam raster scanning. SS-MMM is verified by simulation and experimentally demonstrated by tracking microsphere diffusion in solution. PMID:19516485

  10. Linear modelling of attentional resource allocation

    NASA Technical Reports Server (NTRS)

    Pierce, B.

    1978-01-01

    Eight subjects time-shared performance of two compensatory tracking tasks under conditions when both were of constant difficulty, and when the control order of one task (designated primary) was varied over time within a trial. On line performance feedback was presented on half of the trials. The data are interpreted in terms of a linear model of the operator's attention allocation system, and suggest that this allocation is strongly suboptimal. Furthermore, the limitations in reallocating attentional resources between tasks, in response to difficulty fluctuations were not reduced by augmented performance feedback. Some characteristics of the allocation system are described, and reasons for its limitations suggested.

  11. Stochastic background of atmospheric cascades

    SciTech Connect

    Wilk, G. ); Wlodarczyk, Z. )

    1993-06-15

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions.

  12. Dressing phases of AdS3/CFT2

    NASA Astrophysics Data System (ADS)

    Borsato, Riccardo; Ohlsson Sax, Olof; Sfondrini, Alessandro; Stefański, Bogdan, Jr.; Torrielli, Alessandro

    2013-09-01

    We determine the all-loop dressing phases of the AdS3/CFT2 integrable system related to type IIB string theory on AdS3×S3×T4 by solving the recently found crossing relations and studying their singularity structure. The two resulting phases present a novel structure with respect to the ones appearing in AdS5/CFT4 and AdS4/CFT3. In the strongly coupled regime, their leading order reduces to the universal Arutyunov-Frolov-Staudacher phase as expected. We also compute their subleading order and compare it with recent one-loop perturbative results and comment on their weak-coupling expansion.

  13. Bubbling geometries for AdS2× S2

    NASA Astrophysics Data System (ADS)

    Lunin, Oleg

    2015-10-01

    We construct BPS geometries describing normalizable excitations of AdS2×S2. All regular horizon-free solutions are parameterized by two harmonic functions in R 3 with sources along closed curves. This local structure is reminiscent of the "bubbling solutions" for the other AdS p ×S q cases, however, due to peculiar asymptotic properties of AdS2, one copy of R 3 does not cover the entire space, and we discuss the procedure for analytic continuation, which leads to a nontrivial topological structure of the new geometries. We also study supersymmetric brane probes on the new geometries, which represent the AdS2×S2 counterparts of the giant gravitons.

  14. Mechanical Autonomous Stochastic Heat Engine.

    PubMed

    Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

    2016-07-01

    Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

  15. Mechanical Autonomous Stochastic Heat Engine

    NASA Astrophysics Data System (ADS)

    Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

    2016-07-01

    Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir.

  16. Stochastic resonance in binocular rivalry.

    PubMed

    Kim, Yee-Joon; Grabowecky, Marcia; Suzuki, Satoru

    2006-02-01

    When a different image is presented to each eye, visual awareness spontaneously alternates between the two images--a phenomenon called binocular rivalry. Because binocular rivalry is characterized by two marginally stable perceptual states and spontaneous, apparently stochastic, switching between them, it has been speculated that switches in perceptual awareness reflect a double-well-potential type computational architecture coupled with noise. To characterize this noise-mediated mechanism, we investigated whether stimulus input, neural adaptation, and inhibitory modulations (thought to underlie perceptual switches) interacted with noise in such a way that the system produced stochastic resonance. By subjecting binocular rivalry to weak periodic contrast modulations spanning a range of frequencies, we demonstrated quantitative evidence of stochastic resonance in binocular rivalry. Our behavioral results combined with computational simulations provided insights into the nature of the internal noise (its magnitude, locus, and calibration) that is relevant to perceptual switching, as well as provided novel dynamic constraints on computational models designed to capture the neural mechanisms underlying perceptual switching.

  17. Mechanical Autonomous Stochastic Heat Engine.

    PubMed

    Serra-Garcia, Marc; Foehr, André; Molerón, Miguel; Lydon, Joseph; Chong, Christopher; Daraio, Chiara

    2016-07-01

    Stochastic heat engines are devices that generate work from random thermal motion using a small number of highly fluctuating degrees of freedom. Proposals for such devices have existed for more than a century and include the Maxwell demon and the Feynman ratchet. Only recently have they been demonstrated experimentally, using, e.g., thermal cycles implemented in optical traps. However, recent experimental demonstrations of classical stochastic heat engines are nonautonomous, since they require an external control system that prescribes a heating and cooling cycle and consume more energy than they produce. We present a heat engine consisting of three coupled mechanical resonators (two ribbons and a cantilever) subject to a stochastic drive. The engine uses geometric nonlinearities in the resonating ribbons to autonomously convert a random excitation into a low-entropy, nonpassive oscillation of the cantilever. The engine presents the anomalous heat transport property of negative thermal conductivity, consisting in the ability to passively transfer energy from a cold reservoir to a hot reservoir. PMID:27419553

  18. Model of quantum stochastic absorption in absorbing disordered media

    NASA Astrophysics Data System (ADS)

    Pradhan, Prabhakar

    2006-08-01

    Wave propagation in coherently absorbing disordered media is generally modeled by adding a complex part to the real part of the potential. In such a case, it is already understood that the complex potential plays a duel role; it acts as an absorber as well as a reflector due to the mismatch of the phase of the real and complex parts of the potential. Although this model gives expected results for weakly absorbing disordered media, it gives unphysical results for the strong-absorption regime where it causes the system to behave like a perfect reflector. To overcome this issue, we develop a model here for one-dimentional systems using stochastic absorption for the modeling of absorption by “fake,” or “side,” channels, obviating the need for a complex potential. This model of stochastic absorption eliminates the reflection that is coupled with the absorption in the complex potential model and absorption is proportional to the magnitude of the absorbing parameter. Solving the statistics of the reflection coefficient and its phase for both the models, we argue that stochastic absorption is a potentially better way of modeling absorbing disordered media.

  19. [Value-Added--Adding Economic Value in the Food Industry].

    ERIC Educational Resources Information Center

    Welch, Mary A., Ed.

    1989-01-01

    This booklet focuses on the economic concept of "value added" to goods and services. A student activity worksheet illustrates how the steps involved in processing food are examples of the concept of value added. The booklet further links food processing to the idea of value added to the Gross National Product (GNP). Discussion questions, a student…

  20. Enhanced corticomuscular coherence by external stochastic noise

    PubMed Central

    Trenado, Carlos; Mendez-Balbuena, Ignacio; Manjarrez, Elias; Huethe, Frank; Schulte-Mönting, Jürgen; Feige, Bernd; Hepp-Reymond, Marie-Claude; Kristeva, Rumyana

    2014-01-01

    Noise can have beneficial effects as shown by the stochastic resonance (SR) phenomenon which is characterized by performance improvement when an optimal noise is added. Modern attempts to improve human performance utilize this phenomenon. The purpose of the present study was to investigate whether performance improvement by addition of optimum noise (ON) is related to increased cortical motor spectral power (SP) and increased corticomuscular coherence. Eight subjects performed a visuomotor task requiring to compensate with the right index finger a static force (SF) generated by a manipulandum on which Gaussian noise was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a green bigger circle. Electroencephalogram from the contralateral motor area, electromyogram from active muscles and finger position were recorded. The performance was measured by the mean absolute deviation (MAD) of the white dot from the zero position. ON compared to the zero noise condition induced an improvement in motor accuracy together with an enhancement of cortical motor SP and corticomuscular coherence in beta-range. These data suggest that the improved sensorimotor performance via SR is consistent with an increase in the cortical motor SP and in the corticomuscular coherence. PMID:24904365

  1. Enhanced corticomuscular coherence by external stochastic noise.

    PubMed

    Trenado, Carlos; Mendez-Balbuena, Ignacio; Manjarrez, Elias; Huethe, Frank; Schulte-Mönting, Jürgen; Feige, Bernd; Hepp-Reymond, Marie-Claude; Kristeva, Rumyana

    2014-01-01

    Noise can have beneficial effects as shown by the stochastic resonance (SR) phenomenon which is characterized by performance improvement when an optimal noise is added. Modern attempts to improve human performance utilize this phenomenon. The purpose of the present study was to investigate whether performance improvement by addition of optimum noise (ON) is related to increased cortical motor spectral power (SP) and increased corticomuscular coherence. Eight subjects performed a visuomotor task requiring to compensate with the right index finger a static force (SF) generated by a manipulandum on which Gaussian noise was applied. The finger position was displayed on-line on a monitor as a small white dot which the subjects had to maintain in the center of a green bigger circle. Electroencephalogram from the contralateral motor area, electromyogram from active muscles and finger position were recorded. The performance was measured by the mean absolute deviation (MAD) of the white dot from the zero position. ON compared to the zero noise condition induced an improvement in motor accuracy together with an enhancement of cortical motor SP and corticomuscular coherence in beta-range. These data suggest that the improved sensorimotor performance via SR is consistent with an increase in the cortical motor SP and in the corticomuscular coherence.

  2. Stochastic resonance in human vision and audition

    NASA Astrophysics Data System (ADS)

    Ward, Lawrence M.; Desai, Simren; Rootman, Daniel; Tata, Matthew; Moss, Frank

    2001-03-01

    Stochastic resonance (SR) has been demonstrated in numerous dynamical systems, both model and real, including peripheral sensory neurons and whole animal behavior. We present the first direct evidence that SR is demonstrable also, at a level relevant to behavior in the natural environment, in human visual and auditory signal detection. Human subjects detected either square or sine wave gratings presented mixed with different amounts of pixel noise in the dark on a high-resolution computer monitor, or 3 Hz beats in a 70-Hz base tone, again mixed with different amounts of auditory noise and presented in a sound attenuation chamber while wearing industrial-quality sound-attenuating headphones. In both cases an unbiased index of performance was maximal for intermediate amounts of added noise, indicating that SR enhanced detection of subthreshold signals in both modalities. We present simple and approximate theories of performance in these experiments based on a nondynamical, or threshold, version of SR. We also discuss the possibility that SR is a general property of biological information processing that has been utilized by evolutionary processes.

  3. Doubly stochastic coherence in complex neuronal networks

    NASA Astrophysics Data System (ADS)

    Gao, Yang; Wang, Jianjun

    2012-11-01

    A system composed of coupled FitzHugh-Nagumo neurons with various topological structures is investigated under the co-presence of two independently additive and multiplicative Gaussian white noises, in which particular attention is paid to the neuronal networks spiking regularity. As the additive noise intensity and the multiplicative noise intensity are simultaneously adjusted to optimal values, the temporal periodicity of the output of the system reaches the maximum, indicating the occurrence of doubly stochastic coherence. The network topology randomness exerts different influences on the temporal coherence of the spiking oscillation for dissimilar coupling strength regimes. At a small coupling strength, the spiking regularity shows nearly no difference in the regular, small-world, and completely random networks. At an intermediate coupling strength, the temporal periodicity in a small-world neuronal network can be improved slightly by adding a small fraction of long-range connections. At a large coupling strength, the dynamical behavior of the neurons completely loses the resonance property with regard to the additive noise intensity or the multiplicative noise intensity, and the spiking regularity decreases considerably with the increase of the network topology randomness. The network topology randomness plays more of a depressed role than a favorable role in improving the temporal coherence of the spiking oscillation in the neuronal network research study.

  4. Optimal Resource Allocation in Library Systems

    ERIC Educational Resources Information Center

    Rouse, William B.

    1975-01-01

    Queueing theory is used to model processes as either waiting or balking processes. The optimal allocation of resources to these processes is defined as that which maximizes the expected value of the decision-maker's utility function. (Author)

  5. METHODS OF ANALYSIS FOR WASTE LOAD ALLOCATION

    EPA Science Inventory

    This research has addressed several unresolved questions concerning the allocation of allowable waste loads among multiple wastewater dischargers within a water quality limited stream segment. First, the traditional assumptions about critical design conditions for waste load allo...

  6. AESS: Accelerated Exact Stochastic Simulation

    NASA Astrophysics Data System (ADS)

    Jenkins, David D.; Peterson, Gregory D.

    2011-12-01

    The Stochastic Simulation Algorithm (SSA) developed by Gillespie provides a powerful mechanism for exploring the behavior of chemical systems with small species populations or with important noise contributions. Gene circuit simulations for systems biology commonly employ the SSA method, as do ecological applications. This algorithm tends to be computationally expensive, so researchers seek an efficient implementation of SSA. In this program package, the Accelerated Exact Stochastic Simulation Algorithm (AESS) contains optimized implementations of Gillespie's SSA that improve the performance of individual simulation runs or ensembles of simulations used for sweeping parameters or to provide statistically significant results. Program summaryProgram title: AESS Catalogue identifier: AEJW_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: University of Tennessee copyright agreement No. of lines in distributed program, including test data, etc.: 10 861 No. of bytes in distributed program, including test data, etc.: 394 631 Distribution format: tar.gz Programming language: C for processors, CUDA for NVIDIA GPUs Computer: Developed and tested on various x86 computers and NVIDIA C1060 Tesla and GTX 480 Fermi GPUs. The system targets x86 workstations, optionally with multicore processors or NVIDIA GPUs as accelerators. Operating system: Tested under Ubuntu Linux OS and CentOS 5.5 Linux OS Classification: 3, 16.12 Nature of problem: Simulation of chemical systems, particularly with low species populations, can be accurately performed using Gillespie's method of stochastic simulation. Numerous variations on the original stochastic simulation algorithm have been developed, including approaches that produce results with statistics that exactly match the chemical master equation (CME) as well as other approaches that approximate the CME. Solution

  7. Optimality versus stability in water resource allocation.

    PubMed

    Read, Laura; Madani, Kaveh; Inanloo, Bahareh

    2014-01-15

    Water allocation is a growing concern in a developing world where limited resources like fresh water are in greater demand by more parties. Negotiations over allocations often involve multiple groups with disparate social, economic, and political status and needs, who are seeking a management solution for a wide range of demands. Optimization techniques for identifying the Pareto-optimal (social planner solution) to multi-criteria multi-participant problems are commonly implemented, although often reaching agreement for this solution is difficult. In negotiations with multiple-decision makers, parties who base decisions on individual rationality may find the social planner solution to be unfair, thus creating a need to evaluate the willingness to cooperate and practicality of a cooperative allocation solution, i.e., the solution's stability. This paper suggests seeking solutions for multi-participant resource allocation problems through an economics-based power index allocation method. This method can inform on allocation schemes that quantify a party's willingness to participate in a negotiation rather than opt for no agreement. Through comparison of the suggested method with a range of distance-based multi-criteria decision making rules, namely, least squares, MAXIMIN, MINIMAX, and compromise programming, this paper shows that optimality and stability can produce different allocation solutions. The mismatch between the socially-optimal alternative and the most stable alternative can potentially result in parties leaving the negotiation as they may be too dissatisfied with their resource share. This finding has important policy implications as it justifies why stakeholders may not accept the socially optimal solution in practice, and underlies the necessity of considering stability where it may be more appropriate to give up an unstable Pareto-optimal solution for an inferior stable one. Authors suggest assessing the stability of an allocation solution as an

  8. Neural-Network Processor Would Allocate Resources

    NASA Technical Reports Server (NTRS)

    Eberhardt, Silvio P.; Moopenn, Alexander W.

    1990-01-01

    Global optimization problems solved quickly. Neural-network processor optimizes allocation of M resources among N expenditures according to cost of pairing each resource with each expenditure and subject to limit on number of resources feeding into each expenditure and/or limit on number of expenditures to which each resource allocated. One cell performs several analog and digital functions. Potential applications include assignment of jobs, scheduling, dispatching, and planning of military maneuvers.

  9. Frequency allocations accommodate new commercial applications

    NASA Astrophysics Data System (ADS)

    Stiglitz, Martin R.; Blanchard, Christine

    1992-07-01

    An overview is presented of the 1992 World Administrative Radio Frequency Conference whose principal responsibility is to review and update the International Radio Regulations, including the International Table of Frequency Allocations and the procedures for utilizing the allocations. Consideration is given to the earth exploration-satellite service, the space research space operation, general-satellite service, and wind profiler radar. Attention is given to shortwave or HF broadcasting, mobile and mobile-satellite services and future public land mobile telecommunications systems.

  10. Allocation of authority in European health policy.

    PubMed

    Adolph, Christopher; Greer, Scott L; Massard da Fonseca, Elize

    2012-11-01

    Although many study the effects of different allocations of health policy authority, few ask why countries assign responsibility over different policies as they do. We test two broad theories: fiscal federalism, which predicts rational governments will concentrate information-intensive operations at lower levels, and redistributive and regulatory functions at higher levels; and "politicized federalism", which suggests a combination of systematic and historically idiosyncratic political variables interfere with efficient allocation of authority. Drawing on the WHO Health in Transition country profiles, we present new data on the allocation of responsibility for key health care policy tasks (implementation, provision, finance, regulation, and framework legislation) and policy areas (primary, secondary and tertiary care, public health and pharmaceuticals) in the 27 EU member states and Switzerland. We use a Bayesian multinomial mixed logit model to analyze how different countries arrive at different allocations of authority over each task and area of health policy, and find the allocation of powers broadly follows fiscal federalism. Responsibility for pharmaceuticals, framework legislation, and most finance lodges at the highest levels of government, acute and primary care in the regions, and provision at the local and regional levels. Where allocation does not follow fiscal federalism, it appears to reflect ethnic divisions, the population of states and regions, the presence of mountainous terrain, and the timing of region creation. PMID:22858423

  11. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-01

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison. PMID:26061700

  12. Allocation Games: Addressing the Ill-Posed Nature of Allocation in Life-Cycle Inventories.

    PubMed

    Hanes, Rebecca J; Cruze, Nathan B; Goel, Prem K; Bakshi, Bhavik R

    2015-07-01

    Allocation is required when a life cycle contains multi-functional processes. One approach to allocation is to partition the embodied resources in proportion to a criterion, such as product mass or cost. Many practitioners apply multiple partitioning criteria to avoid choosing one arbitrarily. However, life cycle results from different allocation methods frequently contradict each other, making it difficult or impossible for the practitioner to draw any meaningful conclusions from the study. Using the matrix notation for life-cycle inventory data, we show that an inventory that requires allocation leads to an ill-posed problem: an inventory based on allocation is one of an infinite number of inventories that are highly dependent upon allocation methods. This insight is applied to comparative life-cycle assessment (LCA), in which products with the same function but different life cycles are compared. Recently, there have been several studies that applied multiple allocation methods and found that different products were preferred under different methods. We develop the Comprehensive Allocation Investigation Strategy (CAIS) to examine any given inventory under all possible allocation decisions, enabling us to detect comparisons that are not robust to allocation, even when the comparison appears robust under conventional partitioning methods. While CAIS does not solve the ill-posed problem, it provides a systematic way to parametrize and examine the effects of partitioning allocation. The practical usefulness of this approach is demonstrated with two case studies. The first compares ethanol produced from corn stover hydrolysis, corn stover gasification, and corn grain fermentation. This comparison was not robust to allocation. The second case study compares 1,3-propanediol (PDO) produced from fossil fuels and from biomass, which was found to be a robust comparison.

  13. Action growth for AdS black holes

    NASA Astrophysics Data System (ADS)

    Cai, Rong-Gen; Ruan, Shan-Ming; Wang, Shao-Jiang; Yang, Run-Qiu; Peng, Rong-Hui

    2016-09-01

    Recently a Complexity-Action (CA) duality conjecture has been proposed, which relates the quantum complexity of a holographic boundary state to the action of a Wheeler-DeWitt (WDW) patch in the anti-de Sitter (AdS) bulk. In this paper we further investigate the duality conjecture for stationary AdS black holes and derive some exact results for the growth rate of action within the Wheeler-DeWitt (WDW) patch at late time approximation, which is supposed to be dual to the growth rate of quantum complexity of holographic state. Based on the results from the general D-dimensional Reissner-Nordström (RN)-AdS black hole, rotating/charged Bañados-Teitelboim-Zanelli (BTZ) black hole, Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a universal formula for the action growth expressed in terms of some thermodynamical quantities associated with the outer and inner horizons of the AdS black holes. And we leave the conjecture unchanged that the stationary AdS black hole in Einstein gravity is the fastest computer in nature.

  14. An inexact mixed risk-aversion two-stage stochastic programming model for water resources management under uncertainty.

    PubMed

    Li, W; Wang, B; Xie, Y L; Huang, G H; Liu, L

    2015-02-01

    Uncertainties exist in the water resources system, while traditional two-stage stochastic programming is risk-neutral and compares the random variables (e.g., total benefit) to identify the best decisions. To deal with the risk issues, a risk-aversion inexact two-stage stochastic programming model is developed for water resources management under uncertainty. The model was a hybrid methodology of interval-parameter programming, conditional value-at-risk measure, and a general two-stage stochastic programming framework. The method extends on the traditional two-stage stochastic programming method by enabling uncertainties presented as probability density functions and discrete intervals to be effectively incorporated within the optimization framework. It could not only provide information on the benefits of the allocation plan to the decision makers but also measure the extreme expected loss on the second-stage penalty cost. The developed model was applied to a hypothetical case of water resources management. Results showed that that could help managers generate feasible and balanced risk-aversion allocation plans, and analyze the trade-offs between system stability and economy. PMID:25226833

  15. An inexact mixed risk-aversion two-stage stochastic programming model for water resources management under uncertainty.

    PubMed

    Li, W; Wang, B; Xie, Y L; Huang, G H; Liu, L

    2015-02-01

    Uncertainties exist in the water resources system, while traditional two-stage stochastic programming is risk-neutral and compares the random variables (e.g., total benefit) to identify the best decisions. To deal with the risk issues, a risk-aversion inexact two-stage stochastic programming model is developed for water resources management under uncertainty. The model was a hybrid methodology of interval-parameter programming, conditional value-at-risk measure, and a general two-stage stochastic programming framework. The method extends on the traditional two-stage stochastic programming method by enabling uncertainties presented as probability density functions and discrete intervals to be effectively incorporated within the optimization framework. It could not only provide information on the benefits of the allocation plan to the decision makers but also measure the extreme expected loss on the second-stage penalty cost. The developed model was applied to a hypothetical case of water resources management. Results showed that that could help managers generate feasible and balanced risk-aversion allocation plans, and analyze the trade-offs between system stability and economy.

  16. Stochastic Turing patterns on a network.

    PubMed

    Asslani, Malbor; Di Patti, Francesca; Fanelli, Duccio

    2012-10-01

    The process of stochastic Turing instability on a scale-free network is discussed for a specific case study: the stochastic Brusselator model. The system is shown to spontaneously differentiate into activator-rich and activator-poor nodes outside the region of parameters classically deputed to the deterministic Turing instability. This phenomenon, as revealed by direct stochastic simulations, is explained analytically and eventually traced back to the finite-size corrections stemming from the inherent graininess of the scrutinized medium. PMID:23214650

  17. Stochastic Turing patterns on a network

    NASA Astrophysics Data System (ADS)

    Asslani, Malbor; Di Patti, Francesca; Fanelli, Duccio

    2012-10-01

    The process of stochastic Turing instability on a scale-free network is discussed for a specific case study: the stochastic Brusselator model. The system is shown to spontaneously differentiate into activator-rich and activator-poor nodes outside the region of parameters classically deputed to the deterministic Turing instability. This phenomenon, as revealed by direct stochastic simulations, is explained analytically and eventually traced back to the finite-size corrections stemming from the inherent graininess of the scrutinized medium.

  18. Ant colony optimization and stochastic gradient descent.

    PubMed

    Meuleau, Nicolas; Dorigo, Marco

    2002-01-01

    In this article, we study the relationship between the two techniques known as ant colony optimization (ACO) and stochastic gradient descent. More precisely, we show that some empirical ACO algorithms approximate stochastic gradient descent in the space of pheromones, and we propose an implementation of stochastic gradient descent that belongs to the family of ACO algorithms. We then use this insight to explore the mutual contributions of the two techniques. PMID:12171633

  19. Stochastic Vorticity and Associated Filtering Theory

    SciTech Connect

    Amirdjanova, A.; Kallianpur, G.

    2002-12-19

    The focus of this work is on a two-dimensional stochastic vorticity equation for an incompressible homogeneous viscous fluid. We consider a signed measure-valued stochastic partial differential equation for a vorticity process based on the Skorohod-Ito evolution of a system of N randomly moving point vortices. A nonlinear filtering problem associated with the evolution of the vorticity is considered and a corresponding Fujisaki-Kallianpur-Kunita stochastic differential equation for the optimal filter is derived.

  20. Hierarchical dynamic allocation procedures based on modified Zelen's approach in multiregional studies with unequal allocation.

    PubMed

    Kuznetsova, Olga M; Tymofyeyev, Yevgen

    2014-01-01

    Morrissey, McEntegart, and Lang (2010) showed that in multicenter studies with equal allocation to several treatment arms, the modified Zelen's approach provides excellent within-center and across-study balance in treatment assignments. In this article, hierarchical balancing procedures for equal allocation to more than two arms (with some elements different from earlier versions) and their unequal allocation expansions that incorporate modified Zelen's approach at the center level are described. The balancing properties of the described procedures for a case study of a multiregional clinical trial with 1:2 allocation where balance within regions as well as in other covariates is required are examined through simulations.

  1. Attainability analysis in the stochastic sensitivity control

    NASA Astrophysics Data System (ADS)

    Bashkirtseva, Irina

    2015-02-01

    For nonlinear dynamic stochastic control system, we construct a feedback regulator that stabilises an equilibrium and synthesises a required dispersion of random states around this equilibrium. Our approach is based on the stochastic sensitivity functions technique. We focus on the investigation of attainability sets for 2-D systems. A detailed parametric description of the attainability domains for various types of control inputs for stochastic Brusselator is presented. It is shown that the new regulator provides a low level of stochastic sensitivity and can suppress oscillations of large amplitude.

  2. Optimal reservoir operation considering the water quality issues: A stochastic conflict resolution approach

    NASA Astrophysics Data System (ADS)

    Kerachian, Reza; Karamouz, Mohammad

    2006-12-01

    In this study, an algorithm combining a water quality simulation model and a deterministic/stochastic conflict resolution technique is developed for determining optimal reservoir operating rules. As different decision makers and stakeholders are involved in reservoir operation, the Nash bargaining theory is used to resolve the existing conflict of interests. The utility functions of the proposed models are developed on the basis of the reliability of the water supply to downstream demands, water storage, and the quality of the withdrawn water. The expected value on the Nash product is considered as the objective function of the stochastic model, which can incorporate the inherent uncertainty of reservoir inflow. A water quality simulation model is also developed to simulate the thermal stratification cycle and the reservoir discharge quality through a selective withdrawal structure. The optimization models are solved using a new version of genetic algorithms called varying chromosome length genetic algorithm (VLGA). In this algorithm the chromosome length is sequentially increased to provide a good initial solution for the final traditional GA-based optimization model. The proposed stochastic optimization model can also reduce the computational burden of the previously proposed models such as stochastic dynamic programming (SDP) by reducing the number of state transitions in each stage. The proposed models which are called VLGAQ and SVLGAQ are applied to the 15-Khordad Reservoir in the central part of Iran. The results show that the proposed models can reduce the salinity of allocated water to different water demands as well as the salinity buildup in the reservoir.

  3. Superstring theory in AdS(3) and plane waves

    NASA Astrophysics Data System (ADS)

    Son, John Sang Won

    This thesis is devoted to the study of string theory in AdS 3 and its applications to recent developments in string theory. The difficulties associated with formulating a consistent string theory in AdS3 and its underlying SL(2, R) WZW model are explained. We describe how these difficulties can be overcome by assuming that the SL(2, R) WZW model contains spectral flow symmetry. The existence of spectral flow symmetry in the fully quantum treatment is proved by a calculation of the one-loop string partition function. We consider Euclidean AdS 3 with the time direction periodically identified, and compute the torus partition function in this background. The string spectrum can be reproduced by viewing the one-loop calculation as the free energy of a gas of strings, thus providing a rigorous proof of the results based on spectral flow arguments. Next, we turn to spacetimes that are quotients of AdS 3, which include the BTZ black hole and conical spaces. Strings propagating in the conical space are described by taking an orbifold of strings in AdS3. We show that the twisted states of these orbifolds can be obtained by fractional spectral flow. We show that the shift in the ground state energy usually associated with orbifold twists is absent in this case, and offer a unified framework in which to view spectral flow. Lastly, we consider the RNS superstrings in AdS 3 x S3 x M , where M may be K3 or T 4, based on supersymmetric extensions of SL(2, R) and SU(2) WZW models. We construct the physical states and calculate the spectrum. A subsector of this theory describes strings propagating in the six dimensional plane wave obtained by the Penrose limit of AdS3 x S3 x M . We reproduce the plane wave spectrum by taking J and the radius to infinity. We show that the plane wave spectrum actually coincides with the large J spectrum at fixed radius, i.e. in AdS3 x S3. Relation to some recent topics of interest such as the Frolov-Tseytlin string and strings with critical tension

  4. Stochastic solution to quantum dynamics

    NASA Technical Reports Server (NTRS)

    John, Sarah; Wilson, John W.

    1994-01-01

    The quantum Liouville equation in the Wigner representation is solved numerically by using Monte Carlo methods. For incremental time steps, the propagation is implemented as a classical evolution in phase space modified by a quantum correction. The correction, which is a momentum jump function, is simulated in the quasi-classical approximation via a stochastic process. The technique, which is developed and validated in two- and three- dimensional momentum space, extends an earlier one-dimensional work. Also, by developing a new algorithm, the application to bound state motion in an anharmonic quartic potential shows better agreement with exact solutions in two-dimensional phase space.

  5. Hamilton's principle in stochastic mechanics

    NASA Astrophysics Data System (ADS)

    Pavon, Michele

    1995-12-01

    In this paper we establish three variational principles that provide new foundations for Nelson's stochastic mechanics in the case of nonrelativistic particles without spin. The resulting variational picture is much richer and of a different nature with respect to the one previously considered in the literature. We first develop two stochastic variational principles whose Hamilton-Jacobi-like equations are precisely the two coupled partial differential equations that are obtained from the Schrödinger equation (Madelung equations). The two problems are zero-sum, noncooperative, stochastic differential games that are familiar in the control theory literature. They are solved here by means of a new, absolutely elementary method based on Lagrange functionals. For both games the saddle-point equilibrium solution is given by the Nelson's process and the optimal controls for the two competing players are precisely Nelson's current velocity v and osmotic velocity u, respectively. The first variational principle includes as special cases both the Guerra-Morato variational principle [Phys. Rev. D 27, 1774 (1983)] and Schrödinger original variational derivation of the time-independent equation. It also reduces to the classical least action principle when the intensity of the underlying noise tends to zero. It appears as a saddle-point action principle. In the second variational principle the action is simply the difference between the initial and final configurational entropy. It is therefore a saddle-point entropy production principle. From the variational principles it follows, in particular, that both v(x,t) and u(x,t) are gradients of appropriate principal functions. In the variational principles, the role of the background noise has the intuitive meaning of attempting to contrast the more classical mechanical features of the system by trying to maximize the action in the first principle and by trying to increase the entropy in the second. Combining the two variational

  6. Stochastic thermodynamics of information processing

    NASA Astrophysics Data System (ADS)

    Cardoso Barato, Andre

    2015-03-01

    We consider two recent advancements on theoretical aspects of thermodynamics of information processing. First we show that the theory of stochastic thermodynamics can be generalized to include information reservoirs. These reservoirs can be seen as a sequence of bits which has its Shannon entropy changed due to the interaction with the system. Second we discuss bipartite systems, which provide a convenient description of Maxwell's demon. Analyzing a special class of bipartite systems we show that they can be used to study cellular information processing, allowing for the definition of an entropic rate that quantifies how much a cell learns about a fluctuating external environment and that is bounded by the thermodynamic entropy production.

  7. Constrained Stochastic Extended Redundancy Analysis.

    PubMed

    DeSarbo, Wayne S; Hwang, Heungsun; Stadler Blank, Ashley; Kappe, Eelco

    2015-06-01

    We devise a new statistical methodology called constrained stochastic extended redundancy analysis (CSERA) to examine the comparative impact of various conceptual factors, or drivers, as well as the specific predictor variables that contribute to each driver on designated dependent variable(s). The technical details of the proposed methodology, the maximum likelihood estimation algorithm, and model selection heuristics are discussed. A sports marketing consumer psychology application is provided in a Major League Baseball (MLB) context where the effects of six conceptual drivers of game attendance and their defining predictor variables are estimated. Results compare favorably to those obtained using traditional extended redundancy analysis (ERA). PMID:24327066

  8. Constrained Stochastic Extended Redundancy Analysis.

    PubMed

    DeSarbo, Wayne S; Hwang, Heungsun; Stadler Blank, Ashley; Kappe, Eelco

    2015-06-01

    We devise a new statistical methodology called constrained stochastic extended redundancy analysis (CSERA) to examine the comparative impact of various conceptual factors, or drivers, as well as the specific predictor variables that contribute to each driver on designated dependent variable(s). The technical details of the proposed methodology, the maximum likelihood estimation algorithm, and model selection heuristics are discussed. A sports marketing consumer psychology application is provided in a Major League Baseball (MLB) context where the effects of six conceptual drivers of game attendance and their defining predictor variables are estimated. Results compare favorably to those obtained using traditional extended redundancy analysis (ERA).

  9. Stochastic dynamics on slow manifolds

    NASA Astrophysics Data System (ADS)

    Constable, George W. A.; McKane, Alan J.; Rogers, Tim

    2013-07-01

    The theory of slow manifolds is an important tool in the study of deterministic dynamical systems, giving a practical method by which to reduce the number of relevant degrees of freedom in a model, thereby often resulting in a considerable simplification. In this paper we demonstrate how the same basic methodology may also be applied to stochastic dynamical systems, by examining the behaviour of trajectories conditioned on the event that they do not depart the slow manifold. We apply the method to two models: one from ecology and one from epidemiology, achieving a reduction in model dimension and illustrating the high quality of the analytical approximations.

  10. 24 CFR 791.404 - Field Office allocation planning.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Field Office allocation planning... Allocation of Budget Authority for Housing Assistance § 791.404 Field Office allocation planning. (a) General objective. The allocation planning process should provide for the equitable distribution of available...

  11. 10 CFR 217.54 - Elements of an allocation order.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Allocations System regulation (10 CFR part 217), which is part of the Federal Priorities and Allocations System”; and (e) A current copy of the Energy Priorities and Allocations System regulation (10 CFR part... 10 Energy 3 2014-01-01 2014-01-01 false Elements of an allocation order. 217.54 Section...

  12. 49 CFR 33.54 - Elements of an allocation order.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Transportation Priorities and Allocations System regulation (49 CFR Part 33)”; and (e) A current copy of the Transportation Priorities and Allocations System regulation (49 CFR Part 33) as of the date of the allocation... 49 Transportation 1 2012-10-01 2012-10-01 false Elements of an allocation order. 33.54 Section...

  13. 49 CFR 33.54 - Elements of an allocation order.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Transportation Priorities and Allocations System regulation (49 CFR Part 33)”; and (e) A current copy of the Transportation Priorities and Allocations System regulation (49 CFR Part 33) as of the date of the allocation... 49 Transportation 1 2013-10-01 2013-10-01 false Elements of an allocation order. 33.54 Section...

  14. 49 CFR 33.54 - Elements of an allocation order.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Transportation Priorities and Allocations System regulation (49 CFR Part 33)”; and (e) A current copy of the Transportation Priorities and Allocations System regulation (49 CFR Part 33) as of the date of the allocation... 49 Transportation 1 2014-10-01 2014-10-01 false Elements of an allocation order. 33.54 Section...

  15. 10 CFR 217.54 - Elements of an allocation order.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Allocations System regulation (10 CFR part 217), which is part of the Federal Priorities and Allocations System”; and (e) A current copy of the Energy Priorities and Allocations System regulation (10 CFR part... 10 Energy 3 2012-01-01 2012-01-01 false Elements of an allocation order. 217.54 Section...

  16. 10 CFR 217.54 - Elements of an allocation order.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Allocations System regulation (10 CFR part 217), which is part of the Federal Priorities and Allocations System”; and (e) A current copy of the Energy Priorities and Allocations System regulation (10 CFR part... 10 Energy 3 2013-01-01 2013-01-01 false Elements of an allocation order. 217.54 Section...

  17. The Use of Different Rules to Allocate Reward and Punishment.

    ERIC Educational Resources Information Center

    Mueller, Charles W.

    Much research has been conducted about how and when individuals allocate rewards, yet little research exists concerning the allocation of punishment. The process of allocating negative outcomes may be different from the decision making process for positive outcomes. To examine the decision making process for allocating rewards and punishment,…

  18. 49 CFR 198.13 - Grant allocation formula.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Grant allocation formula. 198.13 Section 198.13... PIPELINE SAFETY PROGRAMS Grant Allocation § 198.13 Grant allocation formula. (a) Beginning in calendar year... state agency comments on any proposed changes to the allocation formula. (f) Grants are limited to...

  19. 49 CFR 198.13 - Grant allocation formula.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Grant allocation formula. 198.13 Section 198.13... PIPELINE SAFETY PROGRAMS Grant Allocation § 198.13 Grant allocation formula. (a) Beginning in calendar year... state agency comments on any proposed changes to the allocation formula. (f) Grants are limited to...

  20. 49 CFR 198.13 - Grant allocation formula.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Grant allocation formula. 198.13 Section 198.13... PIPELINE SAFETY PROGRAMS Grant Allocation § 198.13 Grant allocation formula. (a) Beginning in calendar year... state agency comments on any proposed changes to the allocation formula. (f) Grants are limited to...

  1. 47 CFR 64.903 - Cost allocation manuals.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 3 2010-10-01 2010-10-01 false Cost allocation manuals. 64.903 Section 64.903... RULES RELATING TO COMMON CARRIERS Allocation of Costs § 64.903 Cost allocation manuals. (a) Each... mid-sized incumbent local exchange carriers is required to file a cost allocation manual...

  2. 40 CFR 96.53 - Recordation of NOX allowance allocations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... allocated to an allocation set-aside. (c) Serial numbers for allocated NO X allowances. When allocating NOX... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Recordation of NOX allowance... PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR...

  3. 26 CFR 1.514(e)-1 - Allocation rules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 7 2010-04-01 2010-04-01 true Allocation rules. 1.514(e)-1 Section 1.514(e)-1... Allocation rules. Where only a portion of property is debt-financed property, proper allocation of the basis...)(iii) of § 1.514(b)-1 for illustrations of proper allocation....

  4. 7 CFR 761.202 - Timing of allocations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Timing of allocations. 761.202 Section 761.202... AGRICULTURE SPECIAL PROGRAMS GENERAL PROGRAM ADMINISTRATION Allocation of Farm Loan Programs Funds to State Offices § 761.202 Timing of allocations. The Agency's National Office allocates funds for FO and OL...

  5. 24 CFR 791.404 - Field Office allocation planning.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 4 2011-04-01 2011-04-01 false Field Office allocation planning... Allocation of Budget Authority for Housing Assistance § 791.404 Field Office allocation planning. (a) General... authority, consistent with the relative housing needs of each allocation area within the field...

  6. 26 CFR 1.141-6 - Allocation and accounting rules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Allocation and accounting rules. 1.141-6 Section... Allocation and accounting rules. (a) Allocation of proceeds to expenditures. For purposes of §§ 1.141-1.... Thus, allocations generally may be made using any reasonable, consistently applied accounting...

  7. 26 CFR 1.141-6 - Allocation and accounting rules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Allocation and accounting rules. 1.141-6 Section... Allocation and accounting rules. (a) Allocation of proceeds to expenditures. For purposes of §§ 1.141-1.... Thus, allocations generally may be made using any reasonable, consistently applied accounting...

  8. 26 CFR 1.141-6 - Allocation and accounting rules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Allocation and accounting rules. 1.141-6 Section... Allocation and accounting rules. (a) Allocation of proceeds to expenditures. For purposes of §§ 1.141-1.... Thus, allocations generally may be made using any reasonable, consistently applied accounting...

  9. 10 CFR 455.30 - Allocation of funds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Allocation of funds. 455.30 Section 455.30 Energy... § 455.30 Allocation of funds. (a) DOE will allocate available funds among the States for two purposes... that are eligible pursuant to § 455.91, up to 100 percent of the funds allocated to the State by...

  10. 26 CFR 1.141-6 - Allocation and accounting rules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Thus, allocations generally may be made using any reasonable, consistently applied accounting method... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Allocation and accounting rules. 1.141-6 Section... Allocation and accounting rules. (a) Allocation of proceeds to expenditures. For purposes of §§...

  11. Stochastic ordering properties and optimal routing control for a class of finite capacity queueing systems

    NASA Technical Reports Server (NTRS)

    Towsley, Don; Sparaggis, Panayotis D.; Cassandras, Christos G.

    1990-01-01

    The problem of routing jobs to parallel queues with identical exponential servers and unequal finite buffer capacities is considered. Stochastic ordering and weak majorization properties on critical performance measures are established by means of event-driven inductions. In particular, it is shown that the intuitive 'join the shortest non-full queue' (SNQ) policy is optimal with respect to an overall function that accounts for holding and blocking costs. Moreover, the buffer allocation problem is solved by proving the intuitive result that, for a fixed total buffer capacity, the optimal allocation scheme is the one in which the difference between the maximum and minimum queue capacities is minimized, i.e., becomes either 0 or 1.

  12. Entanglement entropy for free scalar fields in AdS

    NASA Astrophysics Data System (ADS)

    Sugishita, Sotaro

    2016-09-01

    We compute entanglement entropy for free massive scalar fields in anti-de Sitter (AdS) space. The entangling surface is a minimal surface whose boundary is a sphere at the boundary of AdS. The entropy can be evaluated from the thermal free energy of the fields on a topological black hole by using the replica method. In odd-dimensional AdS, exact expressions of the Rényi entropy S n are obtained for arbitrary n. We also evaluate 1-loop corrections coming from the scalar fields to holographic entanglement entropy. Applying the results, we compute the leading difference of entanglement entropy between two holographic CFTs related by a renormalization group flow triggered by a double trace deformation. The difference is proportional to the shift of a central charge under the flow.

  13. Asymptotically AdS spacetimes with a timelike Kasner singularity

    NASA Astrophysics Data System (ADS)

    Ren, Jie

    2016-07-01

    Exact solutions to Einstein's equations for holographic models are presented and studied. The IR geometry has a timelike cousin of the Kasner singularity, which is the less generic case of the BKL (Belinski-Khalatnikov-Lifshitz) singularity, and the UV is asymptotically AdS. This solution describes a holographic RG flow between them. The solution's appearance is an interpolation between the planar AdS black hole and the AdS soliton. The causality constraint is always satisfied. The entanglement entropy and Wilson loops are discussed. The boundary condition for the current-current correlation function and the Laplacian in the IR is examined. There is no infalling wave in the IR, but instead, there is a normalizable solution in the IR. In a special case, a hyperscaling-violating geometry is obtained after a dimensional reduction.

  14. New massive gravity and AdS(4) counterterms.

    PubMed

    Jatkar, Dileep P; Sinha, Aninda

    2011-04-29

    We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026

  15. Detailed ultraviolet asymptotics for AdS scalar field perturbations

    NASA Astrophysics Data System (ADS)

    Evnin, Oleg; Jai-akson, Puttarak

    2016-04-01

    We present a range of methods suitable for accurate evaluation of the leading asymptotics for integrals of products of Jacobi polynomials in limits when the degrees of some or all polynomials inside the integral become large. The structures in question have recently emerged in the context of effective descriptions of small amplitude perturbations in anti-de Sitter (AdS) spacetime. The limit of high degree polynomials corresponds in this situation to effective interactions involving extreme short-wavelength modes, whose dynamics is crucial for the turbulent instabilities that determine the ultimate fate of small AdS perturbations. We explicitly apply the relevant asymptotic techniques to the case of a self-interacting probe scalar field in AdS and extract a detailed form of the leading large degree behavior, including closed form analytic expressions for the numerical coefficients appearing in the asymptotics.

  16. Carbon allocation to ectomycorrhizal fungi correlates with belowground allocation in culture studies.

    PubMed

    Hobbie, Erik A

    2006-03-01

    Ectomycorrhizal fungi form symbioses with most temperate and boreal tree species, but difficulties in measuring carbon allocation to these symbionts have prevented the assessment of their importance in forest ecosystems. Here, I surveyed allocation patterns in 14 culture studies and five field studies of ectomycorrhizal plants. In culture studies, allocation to ectomycorrhizal fungi (NPPf) was linearly related to total belowground net primary production (NPPb) by the equation NPPf = 41.5% x NPPb - 11.3% (r2 = 0.55, P < 0.001) and ranged from 1% to 21% of total net primary production. As a percentage of NPP, allocation to ectomycorrhizal fungi was highest at lowest plant growth rates and lowest nutrient availabilities. Because total belowground allocation can be estimated using carbon balance techniques, these relationships should allow ecologists to incorporate mycorrhizal fungi into existing ecosystem models. In field studies, allocation to ectomycorrhizal fungi ranged from 0% to 22% of total allocation, but wide differences in measurement techniques made intercomparisons difficult. Techniques such as fungal in-growth cores, root branching-order studies, and isotopic analyses could refine our estimates of turnover rates of fine roots, mycorrhizae, and extraradical hyphae. Together with ecosystem modeling, such techniques could soon provide good estimates of the relative importance of root vs. fungal allocation in belowground carbon budgets.

  17. An Analysis and Allocation System for Library Collections Budgets: The Comprehensive Allocation Process (CAP)

    ERIC Educational Resources Information Center

    Lyons, Lucy Eleonore; Blosser, John

    2012-01-01

    The "Comprehensive Allocation Process" (CAP) is a reproducible decision-making structure for the allocation of new collections funds, for the reallocation of funds within stagnant budgets, and for budget cuts in the face of reduced funding levels. This system was designed to overcome common shortcomings of current methods. Its philosophical…

  18. Holography and AdS4 self-gravitating dyons

    NASA Astrophysics Data System (ADS)

    Lugo, A. R.; Moreno, E. F.; Schaposnik, F. A.

    2010-11-01

    We present a self-gravitating dyon solution of the Einstein-Yang-Mills-Higgs equations of motion in asymptotically AdS space. The back reaction of gauge and Higgs fields on the space-time geometry leads to the metric of an asymptotically AdS black hole. Using the gauge/gravity correspondence we analyze relevant properties of the finite temperature quantum field theory defined on the boundary. In particular we identify an order operator, characterize a phase transition of the dual theory on the border and also compute the expectation value of the finite temperature Wilson loop.

  19. AdS box graphs, unitarity and operator product expansions

    NASA Astrophysics Data System (ADS)

    Hoffmann, L.; Mesref, L.; Rühl, W.

    2000-11-01

    We develop a method of singularity analysis for conformal graphs which, in particular, is applicable to the holographic image of AdS supergravity theory. It can be used to determine the critical exponents for any such graph in a given channel. These exponents determine the towers of conformal blocks that are exchanged in this channel. We analyze the scalar AdS box graph and show that it has the same critical exponents as the corresponding CFT box graph. Thus pairs of external fields couple to the same exchanged conformal blocks in both theories. This is looked upon as a general structural argument supporting the Maldacena hypothesis.

  20. Phases of global AdS black holes

    NASA Astrophysics Data System (ADS)

    Basu, Pallab; Krishnan, Chethan; Subramanian, P. N. Bala

    2016-06-01

    We study the phases of gravity coupled to a charged scalar and gauge field in an asymptotically Anti-de Sitter spacetime ( AdS 4) in the grand canonical ensemble. For the conformally coupled scalar, an intricate phase diagram is charted out between the four relevant solutions: global AdS, boson star, Reissner-Nordstrom black hole and the hairy black hole. The nature of the phase diagram undergoes qualitative changes as the charge of the scalar is changed, which we discuss. We also discuss the new features that arise in the extremal limit.

  1. MCdevelop - a universal framework for Stochastic Simulations

    NASA Astrophysics Data System (ADS)

    Slawinska, M.; Jadach, S.

    2011-03-01

    ://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 48 136 No. of bytes in distributed program, including test data, etc.: 355 698 Distribution format: tar.gz Programming language: ANSI C++ Computer: Any computer system or cluster with C++ compiler and UNIX-like operating system. Operating system: Most UNIX systems, Linux. The application programs were thoroughly tested under Ubuntu 7.04, 8.04 and CERN Scientific Linux 5. Has the code been vectorised or parallelised?: Tools (scripts) for optional parallelisation on a PC farm are included. RAM: 500 bytes Classification: 11.3 External routines: ROOT package version 5.0 or higher ( http://root.cern.ch/drupal/). Nature of problem: Developing any type of stochastic simulation program for high energy physics and other areas. Solution method: Object Oriented programming in C++ with added persistency mechanism, batch scripts for running on PC farms and Autotools.

  2. RHIC stochastic cooling motion control

    SciTech Connect

    Gassner, D.; DeSanto, L.; Olsen, R.H.; Fu, W.; Brennan, J.M.; Liaw, CJ; Bellavia, S.; Brodowski, J.

    2011-03-28

    Relativistic Heavy Ion Collider (RHIC) beams are subject to Intra-Beam Scattering (IBS) that causes an emittance growth in all three-phase space planes. The only way to increase integrated luminosity is to counteract IBS with cooling during RHIC stores. A stochastic cooling system for this purpose has been developed, it includes moveable pick-ups and kickers in the collider that require precise motion control mechanics, drives and controllers. Since these moving parts can limit the beam path aperture, accuracy and reliability is important. Servo, stepper, and DC motors are used to provide actuation solutions for position control. The choice of motion stage, drive motor type, and controls are based on needs defined by the variety of mechanical specifications, the unique performance requirements, and the special needs required for remote operations in an accelerator environment. In this report we will describe the remote motion control related beam line hardware, position transducers, rack electronics, and software developed for the RHIC stochastic cooling pick-ups and kickers.

  3. Stochastic Methods for Aircraft Design

    NASA Technical Reports Server (NTRS)

    Pelz, Richard B.; Ogot, Madara

    1998-01-01

    The global stochastic optimization method, simulated annealing (SA), was adapted and applied to various problems in aircraft design. The research was aimed at overcoming the problem of finding an optimal design in a space with multiple minima and roughness ubiquitous to numerically generated nonlinear objective functions. SA was modified to reduce the number of objective function evaluations for an optimal design, historically the main criticism of stochastic methods. SA was applied to many CFD/MDO problems including: low sonic-boom bodies, minimum drag on supersonic fore-bodies, minimum drag on supersonic aeroelastic fore-bodies, minimum drag on HSCT aeroelastic wings, FLOPS preliminary design code, another preliminary aircraft design study with vortex lattice aerodynamics, HSR complete aircraft aerodynamics. In every case, SA provided a simple, robust and reliable optimization method which found optimal designs in order 100 objective function evaluations. Perhaps most importantly, from this academic/industrial project, technology has been successfully transferred; this method is the method of choice for optimization problems at Northrop Grumman.

  4. Numerical tests of stochastic tomography

    NASA Astrophysics Data System (ADS)

    Ru-Shan, Wu; Xiao-Bi, Xie

    1991-05-01

    The method of stochastic tomography proposed by Wu is tested numerically. This method reconstructs the heterospectra (power spectra of heterogeneities) at all depths of a non-uniform random medium using measured joint transverse-angular coherence functions (JTACF) of transmission fluctuations on an array. The inversion method is based on a constrained least-squares inversion implemented via the singular value decomposition. The inversion is also applicable to reconstructions using transverse coherence functions (TCF) or angular coherence functions (ACF); these are merely special cases of JTACF. Through the analysis of sampling functions and singular values, and through numerical examples of reconstruction using theoretically generated coherence functions, we compare the resolution and robustness of reconstructions using TCF, ACF and JTACF. The JTACF can `focus' the coherence analysis at different depths and therefore has a better depth resolution than TCF and ACF. In addition, the JTACF contains much more information than the sum of TCF and ACF, and has much better noise resistance properties than TCF and ACF. Inversion of JTACF can give a reliable reconstruction of heterospectra at different depths even for data with 20% noise contamination. This demonstrates the feasibility of stochastic tomography using JTACF.

  5. Allocating health resources ethically: new roles for administrators and clinicians.

    PubMed

    Veatch, R M

    1991-01-01

    Rationing of health care is an inevitable correlate of living in a world of finite resources. It is morally necessary. The Hippocratic ethic commits clinicians to do whatever will benefit the patient and therefore must be abandoned in a world of moral rationing. After looking at some unacceptable preliminary strategies, two patient-centered adjustments in the Hippocratic ethic, adopting a more objective standard of patient benefit and adding a principle of patient autonomy, are defended. Still, however, cutting the fat out of the system will not be sufficient. A true social ethic of resource allocation will be necessary. A social contract approach supports a principle of equity as a necessary supplement to utility and cost-benefit analysis. It does not follow, however, that clinicians must take on these social ethical decisions. Clinicians should be exempt from normal social ethics so they are free to pursue the objective welfare of patients (provided they consent to such benefit). Administrators are in no better position to allocate scarce resources. What is needed is input from patients to (a) set categorical limits on their own care, (b) articulate principles for fine-tuning the allocation decisions, and (c) supervise professional agents who will make specific gatekeeping decisions for allocating a pool of resources legitimately thought to belong to the patient population. Neither administrators nor clinicians will be responsible for rationing decisions. In 1989 we spent $604.1 billion on health (U.S. Department of Health and Human Services 1990). That is almost $2 billion a day. Sometimes the benefits are dramatic: the pneumonia cured, the heart transplanted, the children spared from infectious diseases with immunizations that cost only pennies. Even so, the American health care system leaves much to be desired. Many other countries have higher life expectancy at birth. Infant mortality in the United States is far higher than countries like Japan and Sweden

  6. Optimal allocation of conservation effort among subpopulations of a threatened species: how important is patch quality?

    PubMed

    Chauvenet, Aliénor L M; Baxter, Peter W J; McDonald-Madden, Eve; Possingham, Hugh P

    2010-04-01

    Money is often a limiting factor in conservation, and attempting to conserve endangered species can be costly. Consequently, a framework for optimizing fiscally constrained conservation decisions for a single species is needed. In this paper we find the optimal budget allocation among isolated subpopulations of a threatened species to minimize local extinction probability. We solve the problem using stochastic dynamic programming, derive a useful and simple alternative guideline for allocating funds, and test its performance using forward simulation. The model considers subpopulations that persist in habitat patches of differing quality, which in our model is reflected in different relationships between money invested and extinction risk. We discover that, in most cases, subpopulations that are less efficient to manage should receive more money than those that are more efficient to manage, due to higher investment needed to reduce extinction risk. Our simple investment guideline performs almost as well as the exact optimal strategy. We illustrate our approach with a case study of the management of the Sumatran tiger, Panthera tigris sumatrae, in Kerinci Seblat National Park (KSNP), Indonesia. We find that different budgets should be allocated to the separate tiger subpopulations in KSNP. The subpopulation that is not at risk of extinction does not require any management investment. Based on the combination of risks of extinction and habitat quality, the optimal allocation for these particular tiger subpopulations is an unusual case: subpopulations that occur in higher-quality habitat (more efficient to manage) should receive more funds than the remaining subpopulation that is in lower-quality habitat. Because the yearly budget allocated to the KSNP for tiger conservation is small, to guarantee the persistence of all the subpopulations that are currently under threat we need to prioritize those that are easier to save. When allocating resources among subpopulations

  7. Optimal allocation of conservation effort among subpopulations of a threatened species: how important is patch quality?

    PubMed

    Chauvenet, Aliénor L M; Baxter, Peter W J; McDonald-Madden, Eve; Possingham, Hugh P

    2010-04-01

    Money is often a limiting factor in conservation, and attempting to conserve endangered species can be costly. Consequently, a framework for optimizing fiscally constrained conservation decisions for a single species is needed. In this paper we find the optimal budget allocation among isolated subpopulations of a threatened species to minimize local extinction probability. We solve the problem using stochastic dynamic programming, derive a useful and simple alternative guideline for allocating funds, and test its performance using forward simulation. The model considers subpopulations that persist in habitat patches of differing quality, which in our model is reflected in different relationships between money invested and extinction risk. We discover that, in most cases, subpopulations that are less efficient to manage should receive more money than those that are more efficient to manage, due to higher investment needed to reduce extinction risk. Our simple investment guideline performs almost as well as the exact optimal strategy. We illustrate our approach with a case study of the management of the Sumatran tiger, Panthera tigris sumatrae, in Kerinci Seblat National Park (KSNP), Indonesia. We find that different budgets should be allocated to the separate tiger subpopulations in KSNP. The subpopulation that is not at risk of extinction does not require any management investment. Based on the combination of risks of extinction and habitat quality, the optimal allocation for these particular tiger subpopulations is an unusual case: subpopulations that occur in higher-quality habitat (more efficient to manage) should receive more funds than the remaining subpopulation that is in lower-quality habitat. Because the yearly budget allocated to the KSNP for tiger conservation is small, to guarantee the persistence of all the subpopulations that are currently under threat we need to prioritize those that are easier to save. When allocating resources among subpopulations

  8. Stochastic non-linear oscillator models of EEG: the Alzheimer's disease case.

    PubMed

    Ghorbanian, Parham; Ramakrishnan, Subramanian; Ashrafiuon, Hashem

    2015-01-01

    In this article, the Electroencephalography (EEG) signal of the human brain is modeled as the output of stochastic non-linear coupled oscillator networks. It is shown that EEG signals recorded under different brain states in healthy as well as Alzheimer's disease (AD) patients may be understood as distinct, statistically significant realizations of the model. EEG signals recorded during resting eyes-open (EO) and eyes-closed (EC) resting conditions in a pilot study with AD patients and age-matched healthy control subjects (CTL) are employed. An optimization scheme is then utilized to match the output of the stochastic Duffing-van der Pol double oscillator network with EEG signals recorded during each condition for AD and CTL subjects by selecting the model physical parameters and noise intensity. The selected signal characteristics are power spectral densities in major brain frequency bands Shannon and sample entropies. These measures allow matching of linear time varying frequency content as well as non-linear signal information content and complexity. The main finding of the work is that statistically significant unique models represent the EC and EO conditions for both CTL and AD subjects. However, it is also shown that the inclusion of sample entropy in the optimization process, to match the complexity of the EEG signal, enhances the stochastic non-linear oscillator model performance. PMID:25964756

  9. Stochastic non-linear oscillator models of EEG: the Alzheimer's disease case

    PubMed Central

    Ghorbanian, Parham; Ramakrishnan, Subramanian; Ashrafiuon, Hashem

    2015-01-01

    In this article, the Electroencephalography (EEG) signal of the human brain is modeled as the output of stochastic non-linear coupled oscillator networks. It is shown that EEG signals recorded under different brain states in healthy as well as Alzheimer's disease (AD) patients may be understood as distinct, statistically significant realizations of the model. EEG signals recorded during resting eyes-open (EO) and eyes-closed (EC) resting conditions in a pilot study with AD patients and age-matched healthy control subjects (CTL) are employed. An optimization scheme is then utilized to match the output of the stochastic Duffing—van der Pol double oscillator network with EEG signals recorded during each condition for AD and CTL subjects by selecting the model physical parameters and noise intensity. The selected signal characteristics are power spectral densities in major brain frequency bands Shannon and sample entropies. These measures allow matching of linear time varying frequency content as well as non-linear signal information content and complexity. The main finding of the work is that statistically significant unique models represent the EC and EO conditions for both CTL and AD subjects. However, it is also shown that the inclusion of sample entropy in the optimization process, to match the complexity of the EEG signal, enhances the stochastic non-linear oscillator model performance. PMID:25964756

  10. Stochastic Modeling of Laminar-Turbulent Transition

    NASA Technical Reports Server (NTRS)

    Rubinstein, Robert; Choudhari, Meelan

    2002-01-01

    Stochastic versions of stability equations are developed in order to develop integrated models of transition and turbulence and to understand the effects of uncertain initial conditions on disturbance growth. Stochastic forms of the resonant triad equations, a high Reynolds number asymptotic theory, and the parabolized stability equations are developed.

  11. Attainability analysis in stochastic controlled systems

    SciTech Connect

    Ryashko, Lev

    2015-03-10

    A control problem for stochastically forced nonlinear continuous-time systems is considered. We propose a method for construction of the regulator that provides a preassigned probabilistic distribution of random states in stochastic equilibrium. Geometric criteria of the controllability are obtained. Constructive technique for the specification of attainability sets is suggested.

  12. From Complex to Simple: Interdisciplinary Stochastic Models

    ERIC Educational Resources Information Center

    Mazilu, D. A.; Zamora, G.; Mazilu, I.

    2012-01-01

    We present two simple, one-dimensional, stochastic models that lead to a qualitative understanding of very complex systems from biology, nanoscience and social sciences. The first model explains the complicated dynamics of microtubules, stochastic cellular highways. Using the theory of random walks in one dimension, we find analytical expressions…

  13. Variational principles for stochastic fluid dynamics

    PubMed Central

    Holm, Darryl D.

    2015-01-01

    This paper derives stochastic partial differential equations (SPDEs) for fluid dynamics from a stochastic variational principle (SVP). The paper proceeds by taking variations in the SVP to derive stochastic Stratonovich fluid equations; writing their Itô representation; and then investigating the properties of these stochastic fluid models in comparison with each other, and with the corresponding deterministic fluid models. The circulation properties of the stochastic Stratonovich fluid equations are found to closely mimic those of the deterministic ideal fluid models. As with deterministic ideal flows, motion along the stochastic Stratonovich paths also preserves the helicity of the vortex field lines in incompressible stochastic flows. However, these Stratonovich properties are not apparent in the equivalent Itô representation, because they are disguised by the quadratic covariation drift term arising in the Stratonovich to Itô transformation. This term is a geometric generalization of the quadratic covariation drift term already found for scalar densities in Stratonovich's famous 1966 paper. The paper also derives motion equations for two examples of stochastic geophysical fluid dynamics; namely, the Euler–Boussinesq and quasi-geostropic approximations. PMID:27547083

  14. The forecaster's added value

    NASA Astrophysics Data System (ADS)

    Turco, M.; Milelli, M.

    2009-09-01

    skill scores of two competitive forecast. It is important to underline that the conclusions refer to the analysis of the Piemonte operational alert system, so they cannot be directly taken as universally true. But we think that some of the main lessons that can be derived from this study could be useful for the meteorological community. In details, the main conclusions are the following: - despite the overall improvement in global scale and the fact that the resolution of the limited area models has increased considerably over recent years, the QPF produced by the meteorological models involved in this study has not improved enough to allow its direct use, that is, the subjective HQPF continues to offer the best performance; - in the forecast process, the step where humans have the largest added value with respect to mathematical models, is the communication. In fact the human characterisation and communication of the forecast uncertainty to end users cannot be replaced by any computer code; - eventually, although there is no novelty in this study, we would like to show that the correct application of appropriated statistical techniques permits a better definition and quantification of the errors and, mostly important, allows a correct (unbiased) communication between forecasters and decision makers.

  15. Stochastic ion acceleration by beating electrostatic waves.

    PubMed

    Jorns, B; Choueiri, E Y

    2013-01-01

    A study is presented of the stochasticity in the orbit of a single, magnetized ion produced by the particle's interaction with two beating electrostatic waves whose frequencies differ by the ion cyclotron frequency. A second-order Lie transform perturbation theory is employed in conjunction with a numerical analysis of the maximum Lyapunov exponent to determine the velocity conditions under which stochasticity occurs in this dynamical system. Upper and lower bounds in ion velocity are found for stochastic orbits with the lower bound approximately equal to the phase velocity of the slower wave. A threshold condition for the onset of stochasticity that is linear with respect to the wave amplitudes is also derived. It is shown that the onset of stochasticity occurs for beating electrostatic waves at lower total wave energy densities than for the case of a single electrostatic wave or two nonbeating electrostatic waves. PMID:23410446

  16. On controllability of nonlinear stochastic systems

    NASA Astrophysics Data System (ADS)

    Sakthivel, R.; Kim, J.-H.; Mahmudov, N. I.

    2006-12-01

    In this paper, complete controllability for nonlinear stochastic systems is studied. First this paper addresses the problem of complete controllability of nonlinear stochastic systems with standard Brownian motion. Then this result is extended to establish complete controllability criterion for stochastic systems with fractional Brownian motion. A fixed point approach is employed for achieving the required result. The solutions are given by a variation of constants formula which allows us to study the complete controllability for nonlinear stochastic systems. In this paper, we prove the complete controllability of nonlinear stochastic system under the natural assumption that the associated linear control system is completely controllable. Finally, an illustrative example is provided to show the usefulness of the proposed technique.

  17. Biomass Resource Allocation among Competing End Uses

    SciTech Connect

    Newes, E.; Bush, B.; Inman, D.; Lin, Y.; Mai, T.; Martinez, A.; Mulcahy, D.; Short, W.; Simpkins, T.; Uriarte, C.; Peck, C.

    2012-05-01

    The Biomass Scenario Model (BSM) is a system dynamics model developed by the U.S. Department of Energy as a tool to better understand the interaction of complex policies and their potential effects on the biofuels industry in the United States. However, it does not currently have the capability to account for allocation of biomass resources among the various end uses, which limits its utilization in analysis of policies that target biomass uses outside the biofuels industry. This report provides a more holistic understanding of the dynamics surrounding the allocation of biomass among uses that include traditional use, wood pellet exports, bio-based products and bioproducts, biopower, and biofuels by (1) highlighting the methods used in existing models' treatments of competition for biomass resources; (2) identifying coverage and gaps in industry data regarding the competing end uses; and (3) exploring options for developing models of biomass allocation that could be integrated with the BSM to actively exchange and incorporate relevant information.

  18. Task mapping for non-contiguous allocations.

    SciTech Connect

    Leung, Vitus Joseph; Bunde, David P.; Ebbers, Johnathan; Price, Nicholas W.; Swank, Matthew.; Feer, Stefan P.; Rhodes, Zachary D.

    2013-02-01

    This paper examines task mapping algorithms for non-contiguously allocated parallel jobs. Several studies have shown that task placement affects job running time for both contiguously and non-contiguously allocated jobs. Traditionally, work on task mapping either uses a very general model where the job has an arbitrary communication pattern or assumes that jobs are allocated contiguously, making them completely isolated from each other. A middle ground between these two cases is the mapping problem for non-contiguous jobs having a specific communication pattern. We propose several task mapping algorithms for jobs with a stencil communication pattern and evaluate them using experiments and simulations. Our strategies improve the running time of a MiniApp by as much as 30% over a baseline strategy. Furthermore, this improvement increases markedly with the job size, demonstrating the importance of task mapping as systems grow toward exascale.

  19. Allocation of Attention by Fishing Vessel Watchkeepers

    NASA Astrophysics Data System (ADS)

    Findlay, Malcolm

    2006-05-01

    This study examines the way in which attention is allocated by watchkeepers on fishing vessels and identifies differences in the approach displayed by individuals with different levels of training and experience. A method of analysing the way in which attention is allocated on a sample of UK fishing vessels is described. It was found that both skippers and mates allocated disproportionate amounts of attention to fishfinding equipment at certain stages of the fishing trip, while crewmen were heavily reliant upon the track plotter both while fishing and on passage. Those with more training and experience appeared to treat the array of navigation and control components as an integrated system, while untrained crewmen dealt with each aspect in isolation.

  20. Competing Principles for Allocating Health Care Resources.

    PubMed

    Carter, Drew; Gordon, Jason; Watt, Amber M

    2016-10-01

    We clarify options for conceptualizing equity, or what we refer to as justice, in resource allocation. We do this by systematically differentiating, expounding, and then illustrating eight different substantive principles of justice. In doing this, we compare different meanings that can be attributed to "need" and "the capacity to benefit" (CTB). Our comparison is sharpened by two analytical tools. First, quantification helps to clarify the divergent consequences of allocations commended by competing principles. Second, a diagrammatic approach developed by economists Culyer and Wagstaff offers a visual and conceptual aid. Of the eight principles we illustrate, only two treat as relevant both a person's initial health state and a person's CTB per resource unit expended: (1) allocate resources so as to most closely equalize final health states and (2) allocate resources so as to equally restore health states to population norms. These allocative principles ought to be preferred to the alternatives if one deems relevant both a person's initial health state and a person's CTB per resource unit expended. Finally, we examine some possibilities for conceptualizing benefits as relative to how badly off someone is, extending Parfit's thought on Prioritarianism (a prioritizing of the worst off). Questions arise as to how much intervention effects accruing to the worse off count for more and how this changes with improving health. We explicate some recent efforts to answer these questions, including in Dutch and British government circles. These efforts can be viewed as efforts to operationalize need as an allocative principle. Each effort seeks to maximize in the aggregate quanta of effect that are differentially valued in favor of the worst off. In this respect, each effort constitutes one type of Prioritarianism, which Parfit failed to differentiate from other types.

  1. D-branes on AdS flux compactifications

    NASA Astrophysics Data System (ADS)

    Koerber, Paul; Martucci, Luca

    2008-01-01

    We study D-branes in Script N = 1 flux compactifications to AdS4. We derive their supersymmetry conditions and express them in terms of background generalized calibrations. Basically because AdS has a boundary, the analysis of stability is more subtle and qualitatively different from the usual case of Minkowski compactifications. For instance, stable D-branes filling AdS4 may wrap trivial internal cycles. Our analysis gives a geometric realization of the four-dimensional field theory approach of Freedman and collaborators. Furthermore, the one-to-one correspondence between the supersymmetry conditions of the background and the existence of generalized calibrations for D-branes is clarified and extended to any supersymmetric flux background that admits a time-like Killing vector and for which all fields are time-independent with respect to the associated time. As explicit examples, we discuss supersymmetric D-branes on IIA nearly Kähler AdS4 flux compactifications.

  2. Dyonic AdS black holes from magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Caldarelli, Marco M.; Dias, Óscar J. C.; Klemm, Dietmar

    2009-03-01

    We use the AdS/CFT correspondence to argue that large dyonic black holes in anti-de Sitter spacetime are dual to stationary solutions of the equations of relativistic magnetohydrodynamics on the conformal boundary of AdS. The dyonic Kerr-Newman-AdS4 solution corresponds to a charged diamagnetic fluid not subject to any net Lorentz force, due to orthogonal magnetic and electric fields compensating each other. The conserved charges, stress tensor and R-current of the fluid are shown to be in exact agreement with the corresponding quantities of the black hole. Furthermore, we obtain stationary solutions of the Navier-Stokes equations in four dimensions, which yield predictions for (yet to be constructed) charged rotating black strings in AdS5 carrying nonvanishing momentum along the string. Finally, we consider Scherk-Schwarz reduced AdS gravity on a circle. In this theory, large black holes and black strings are dual to lumps of deconfined plasma of the associated CFT. We analyze the effects that a magnetic field introduces in the Rayleigh-Plateau instability of a plasma tube, which is holographically dual to the Gregory-Laflamme instability of a magnetically charged black string.

  3. AdS Branes from Partial Breaking of Superconformal Symmetries

    SciTech Connect

    Ivanov, E.A.

    2005-10-01

    It is shown how the static-gauge world-volume superfield actions of diverse superbranes on the AdS{sub d+1} superbackgrounds can be systematically derived from nonlinear realizations of the appropriate AdS supersymmetries. The latter are treated as superconformal symmetries of flat Minkowski superspaces of the bosonic dimension d. Examples include the N = 1 AdS{sub 4} supermembrane, which is associated with the 1/2 partial breaking of the OSp(1|4) supersymmetry down to the N = 1, d = 3 Poincare supersymmetry, and the T-duality related L3-brane on AdS{sub 5} and scalar 3-brane on AdS{sub 5} x S{sup 1}, which are associated with two different patterns of 1/2 breaking of the SU(2, 2|1) supersymmetry. Another (closely related) topic is the AdS/CFT equivalence transformation. It maps the world-volume actions of the codimension-one AdS{sub d+1} (super)branes onto the actions of the appropriate Minkowski (super)conformal field theories in the dimension d.

  4. Worldsheet dilatation operator for the AdS superstring

    NASA Astrophysics Data System (ADS)

    Ramírez, Israel; Vallilo, Brenno Carlini

    2016-05-01

    In this work we propose a systematic way to compute the logarithmic divergences of composite operators in the pure spinor description of the AdS 5 × S 5 superstring. The computations of these divergences can be summarized in terms of a dilatation operator acting on the local operators. We check our results with some important composite operators of the formalism.

  5. Stochastic regularization operators on unstructured meshes

    NASA Astrophysics Data System (ADS)

    Jordi, Claudio; Doetsch, Joseph; Günther, Thomas; Schmelzbach, Cedric; Robertsson, Johan

    2016-04-01

    Most geophysical inverse problems require the solution of underdetermined systems of equations. In order to solve such inverse problems, appropriate regularization is required. Ideally, this regularization includes information on the expected model variability and spatial correlation. Based on geostatistical covariance functions, which can be adapted to the specific situation, stochastic regularization can be used to add auxiliary constraints to the given inverse problem. Stochastic regularization operators have been successfully applied to geophysical inverse problems formulated on regular grids. Here, we demonstrate the calculation of stochastic regularization operators for unstructured meshes. Unstructured meshes are advantageous with regards to incorporating arbitrary topography, undulating geological interfaces and complex acquisition geometries into the inversion. However, compared to regular grids, unstructured meshes have variable cell sizes, complicating the calculation of stochastic operators. The stochastic operators proposed here are based on a 2D exponential correlation function, allowing to predefine spatial correlation lengths. The regularization thus acts over an imposed correlation length rather than only taking into account neighbouring cells as in regular smoothing constraints. Correlation over a spatial length partly removes the effects of variable cell sizes of unstructured meshes on the regularization. Synthetic models having large-scale interfaces as well as small-scale stochastic variations are used to analyse the performance and behaviour of the stochastic regularization operators. The resulting inverted models obtained with stochastic regularization are compare against the results of standard regularization approaches (damping and smoothing). Besides using stochastic operators for regularization, we plan to incorporate the footprint of the stochastic operator in further applications such as the calculation of the cross-gradient functions

  6. The Allocation of Federal Expenditures Among States

    NASA Technical Reports Server (NTRS)

    Lee, Maw Lin

    1967-01-01

    This study explores factors associated with the allocation offederal expenditures by states and examines the implications of theseexpenditures on the state by state distribution of incomes. Theallocation of federal expenditures is functionally oriented toward theobjectives for which various government programs are set up. Thegeographical distribution of federal expenditures, therefore, washistorically considered to be a problem incidental to governmentactivity. Because of this, relatively little attention was given tothe question of why some states receive more federal allocation thanothers. In addition, the implications of this pattern of allocationamong the several states have not been intensively investigated.

  7. Entanglement temperature and perturbed AdS3 geometry

    NASA Astrophysics Data System (ADS)

    Levine, G. C.; Caravan, B.

    2016-06-01

    Generalizing the first law of thermodynamics, the increase in entropy density δ S (x ) of a conformal field theory (CFT) is proportional to the increase in energy density, δ E (x ) , of a subsystem divided by a spatially dependent entanglement temperature, TE(x ) , a fixed parameter determined by the geometry of the subsystem, crossing over to thermodynamic temperature at high temperatures. In this paper we derive a generalization of the thermodynamic Clausius relation, showing that deformations of the CFT by marginal operators are associated with spatial temperature variations, δ TE(x ) , and spatial energy correlations play the role of specific heat. Using AdS/CFT duality we develop a relationship between a perturbation in the local entanglement temperature of the CFT and the perturbation of the bulk AdS metric. In two dimensions, we demonstrate a method through which direct diagonalizations of the boundary quantum theory may be used to construct geometric perturbations of AdS3 .

  8. Stochastic Drift in Mitochondrial DNA Point Mutations: A Novel Perspective Ex Silico

    PubMed Central

    Poovathingal, Suresh Kumar; Gruber, Jan; Halliwell, Barry; Gunawan, Rudiyanto

    2009-01-01

    The mitochondrial free radical theory of aging (mFRTA) implicates Reactive Oxygen Species (ROS)-induced mutations of mitochondrial DNA (mtDNA) as a major cause of aging. However, fifty years after its inception, several of its premises are intensely debated. Much of this uncertainty is due to the large range of values in the reported experimental data, for example on oxidative damage and mutational burden in mtDNA. This is in part due to limitations with available measurement technologies. Here we show that sample preparations in some assays necessitating high dilution of DNA (single molecule level) may introduce significant statistical variability. Adding to this complexity is the intrinsically stochastic nature of cellular processes, which manifests in cells from the same tissue harboring varying mutation load. In conjunction, these random elements make the determination of the underlying mutation dynamics extremely challenging. Our in silico stochastic study reveals the effect of coupling the experimental variability and the intrinsic stochasticity of aging process in some of the reported experimental data. We also show that the stochastic nature of a de novo point mutation generated during embryonic development is a major contributor of different mutation burdens in the individuals of mouse population. Analysis of simulation results leads to several new insights on the relevance of mutation stochasticity in the context of dividing tissues and the plausibility of ROS ”vicious cycle” hypothesis. PMID:19936024

  9. Deterministic and stochastic bifurcations in the Hindmarsh-Rose neuronal model.

    PubMed

    Dtchetgnia Djeundam, S R; Yamapi, R; Kofane, T C; Aziz-Alaoui, M A

    2013-09-01

    We analyze the bifurcations occurring in the 3D Hindmarsh-Rose neuronal model with and without random signal. When under a sufficient stimulus, the neuron activity takes place; we observe various types of bifurcations that lead to chaotic transitions. Beside the equilibrium solutions and their stability, we also investigate the deterministic bifurcation. It appears that the neuronal activity consists of chaotic transitions between two periodic phases called bursting and spiking solutions. The stochastic bifurcation, defined as a sudden change in character of a stochastic attractor when the bifurcation parameter of the system passes through a critical value, or under certain condition as the collision of a stochastic attractor with a stochastic saddle, occurs when a random Gaussian signal is added. Our study reveals two kinds of stochastic bifurcation: the phenomenological bifurcation (P-bifurcations) and the dynamical bifurcation (D-bifurcations). The asymptotical method is used to analyze phenomenological bifurcation. We find that the neuronal activity of spiking and bursting chaos remains for finite values of the noise intensity.

  10. Stochastic inflation and nonlinear gravity

    NASA Astrophysics Data System (ADS)

    Salopek, D. S.; Bond, J. R.

    1991-02-01

    We show how nonlinear effects of the metric and scalar fields may be included in stochastic inflation. Our formalism can be applied to non-Gaussian fluctuation models for galaxy formation. Fluctuations with wavelengths larger than the horizon length are governed by a network of Langevin equations for the physical fields. Stochastic noise terms arise from quantum fluctuations that are assumed to become classical at horizon crossing and that then contribute to the background. Using Hamilton-Jacobi methods, we solve the Arnowitt-Deser-Misner constraint equations which allows us to separate the growing modes from the decaying ones in the drift phase following each stochastic impulse. We argue that the most reasonable choice of time hypersurfaces for the Langevin system during inflation is T=ln(Ha), where H and a are the local values of the Hubble parameter and the scale factor, since T is the natural time for evolving the short-wavelength scalar field fluctuations in an inhomogeneous background. We derive a Fokker-Planck equation which describes how the probability distribution of scalar field values at a given spatial point evolves in T. Analytic Green's-function solutions obtained for a single scalar field self-interacting through an exponential potential are used to demonstrate (1) if the initial condition of the Hubble parameter is chosen to be consistent with microwave-background limits, H(φ0)/mρ<~10-4, then the fluctuations obey Gaussian statistics to a high precision, independent of the time hypersurface choice and operator-ordering ambiguities in the Fokker-Planck equation, and (2) for scales much larger than our present observable patch of the Universe, the distribution is non-Gaussian, with a tail extending to large energy densities; although there are no observable manifestations, it does show eternal inflation. Lattice simulations of our Langevin network for the exponential potential demonstrate how spatial correlations are incorporated. An initially

  11. Impact of deterministic and stochastic updates on network reciprocity in the prisoner's dilemma game.

    PubMed

    Tanimoto, Jun

    2014-08-01

    In 2 × 2 prisoner's dilemma games, network reciprocity is one mechanism for adding social viscosity, which leads to cooperative equilibrium. This study introduced an intriguing framework for the strategy update rule that allows any combination of a purely deterministic method, imitation max (IM), and a purely probabilistic one, pairwise Fermi (Fermi-PW). A series of simulations covering the whole range from IM to Fermi-PW reveals that, as a general tendency, the larger fractions of stochastic updating reduce network reciprocity, so long as the underlying lattice contains no noise in the degree of distribution. However, a small amount of stochastic flavor added to an otherwise perfectly deterministic update rule was actually found to enhance network reciprocity. This occurs because a subtle stochastic effect in the update rule improves the evolutionary trail in games having more stag-hunt-type dilemmas, although the same stochastic effect degenerates evolutionary trails in games having more chicken-type dilemmas. We explain these effects by dividing evolutionary trails into the enduring and expanding periods defined by Shigaki et al. [Phys. Rev. E 86, 031141 (2012)].

  12. Impact of deterministic and stochastic updates on network reciprocity in the prisoner's dilemma game.

    PubMed

    Tanimoto, Jun

    2014-08-01

    In 2 × 2 prisoner's dilemma games, network reciprocity is one mechanism for adding social viscosity, which leads to cooperative equilibrium. This study introduced an intriguing framework for the strategy update rule that allows any combination of a purely deterministic method, imitation max (IM), and a purely probabilistic one, pairwise Fermi (Fermi-PW). A series of simulations covering the whole range from IM to Fermi-PW reveals that, as a general tendency, the larger fractions of stochastic updating reduce network reciprocity, so long as the underlying lattice contains no noise in the degree of distribution. However, a small amount of stochastic flavor added to an otherwise perfectly deterministic update rule was actually found to enhance network reciprocity. This occurs because a subtle stochastic effect in the update rule improves the evolutionary trail in games having more stag-hunt-type dilemmas, although the same stochastic effect degenerates evolutionary trails in games having more chicken-type dilemmas. We explain these effects by dividing evolutionary trails into the enduring and expanding periods defined by Shigaki et al. [Phys. Rev. E 86, 031141 (2012)]. PMID:25215687

  13. Stochastic thermodynamics for active matter

    NASA Astrophysics Data System (ADS)

    Speck, Thomas

    2016-05-01

    The theoretical understanding of active matter, which is driven out of equilibrium by directed motion, is still fragmental and model oriented. Stochastic thermodynamics, on the other hand, is a comprehensive theoretical framework for driven systems that allows to define fluctuating work and heat. We apply these definitions to active matter, assuming that dissipation can be modelled by effective non-conservative forces. We show that, through the work, conjugate extensive and intensive observables can be defined even in non-equilibrium steady states lacking a free energy. As an illustration, we derive the expressions for the pressure and interfacial tension of active Brownian particles. The latter becomes negative despite the observed stable phase separation. We discuss this apparent contradiction, highlighting the role of fluctuations, and we offer a tentative explanation.

  14. Thermodynamics of stochastic Turing machines.

    PubMed

    Strasberg, Philipp; Cerrillo, Javier; Schaller, Gernot; Brandes, Tobias

    2015-10-01

    In analogy to Brownian computers we explicitly show how to construct stochastic models which mimic the behavior of a general-purpose computer (a Turing machine). Our models are discrete state systems obeying a Markovian master equation, which are logically reversible and have a well-defined and consistent thermodynamic interpretation. The resulting master equation, which describes a simple one-step process on an enormously large state space, allows us to thoroughly investigate the thermodynamics of computation for this situation. Especially in the stationary regime we can well approximate the master equation by a simple Fokker-Planck equation in one dimension. We then show that the entropy production rate at steady state can be made arbitrarily small, but the total (integrated) entropy production is finite and grows logarithmically with the number of computational steps. PMID:26565165

  15. Stochastic dynamics of dengue epidemics

    NASA Astrophysics Data System (ADS)

    de Souza, David R.; Tomé, Tânia; Pinho, Suani T. R.; Barreto, Florisneide R.; de Oliveira, Mário J.

    2013-01-01

    We use a stochastic Markovian dynamics approach to describe the spreading of vector-transmitted diseases, such as dengue, and the threshold of the disease. The coexistence space is composed of two structures representing the human and mosquito populations. The human population follows a susceptible-infected-recovered (SIR) type dynamics and the mosquito population follows a susceptible-infected-susceptible (SIS) type dynamics. The human infection is caused by infected mosquitoes and vice versa, so that the SIS and SIR dynamics are interconnected. We develop a truncation scheme to solve the evolution equations from which we get the threshold of the disease and the reproductive ratio. The threshold of the disease is also obtained by performing numerical simulations. We found that for certain values of the infection rates the spreading of the disease is impossible, for any death rate of infected mosquitoes.

  16. Stochastic sensing through covalent interactions

    DOEpatents

    Bayley, Hagan; Shin, Seong-Ho; Luchian, Tudor; Cheley, Stephen

    2013-03-26

    A system and method for stochastic sensing in which the analyte covalently bonds to the sensor element or an adaptor element. If such bonding is irreversible, the bond may be broken by a chemical reagent. The sensor element may be a protein, such as the engineered P.sub.SH type or .alpha.HL protein pore. The analyte may be any reactive analyte, including chemical weapons, environmental toxins and pharmaceuticals. The analyte covalently bonds to the sensor element to produce a detectable signal. Possible signals include change in electrical current, change in force, and change in fluorescence. Detection of the signal allows identification of the analyte and determination of its concentration in a sample solution. Multiple analytes present in the same solution may be detected.

  17. Stochastic low Reynolds number swimmers.

    PubMed

    Golestanian, Ramin; Ajdari, Armand

    2009-05-20

    As technological advances allow us to fabricate smaller autonomous self-propelled devices, it is clear that at some point directed propulsion could not come from pre-specified deterministic periodic deformation of the swimmer's body and we need to develop strategies for extracting a net directed motion from a series of random transitions in the conformation space of the swimmer. We present a theoretical formulation for describing the 'stochastic motor' that drives the motion of low Reynolds number swimmers based on this concept, and use it to study the propulsion of a simple low Reynolds number swimmer, namely, the three-sphere swimmer model. When the detailed balanced is broken and the motor is driven out of equilibrium, it can propel the swimmer in the required direction. The formulation can be used to study optimal design strategies for molecular scale low Reynolds number swimmers.

  18. Heuristic-biased stochastic sampling

    SciTech Connect

    Bresina, J.L.

    1996-12-31

    This paper presents a search technique for scheduling problems, called Heuristic-Biased Stochastic Sampling (HBSS). The underlying assumption behind the HBSS approach is that strictly adhering to a search heuristic often does not yield the best solution and, therefore, exploration off the heuristic path can prove fruitful. Within the HBSS approach, the balance between heuristic adherence and exploration can be controlled according to the confidence one has in the heuristic. By varying this balance, encoded as a bias function, the HBSS approach encompasses a family of search algorithms of which greedy search and completely random search are extreme members. We present empirical results from an application of HBSS to the realworld problem of observation scheduling. These results show that with the proper bias function, it can be easy to outperform greedy search.

  19. Multiscale Stochastic Simulation and Modeling

    SciTech Connect

    James Glimm; Xiaolin Li

    2006-01-10

    Acceleration driven instabilities of fluid mixing layers include the classical cases of Rayleigh-Taylor instability, driven by a steady acceleration and Richtmyer-Meshkov instability, driven by an impulsive acceleration. Our program starts with high resolution methods of numerical simulation of two (or more) distinct fluids, continues with analytic analysis of these solutions, and the derivation of averaged equations. A striking achievement has been the systematic agreement we obtained between simulation and experiment by using a high resolution numerical method and improved physical modeling, with surface tension. Our study is accompanies by analysis using stochastic modeling and averaged equations for the multiphase problem. We have quantified the error and uncertainty using statistical modeling methods.

  20. Effective Ad-Hoc Committees.

    ERIC Educational Resources Information Center

    Young, David G.

    1983-01-01

    Ad-hoc committees may be symbolic, informational, or action committees. A literature survey indicates such committees' structural components include a suprasystem and three subsystems involving linkages, production, and implementation. Other variables include size, personal factors, and timing. All the factors carry implications about ad-hoc…

  1. Lorentzian AdS geometries, wormholes, and holography

    SciTech Connect

    Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo

    2011-03-15

    We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.

  2. One-loop diagrams in AdS space

    SciTech Connect

    Hung Lingyan; Shang Yanwen

    2011-01-15

    We study the complex scalar loop corrections to the boundary-boundary gauge two-point function in pure AdS space in Poincare coordinates, in the presence of boundary quadratic perturbations to the scalar. These perturbations correspond to double-trace perturbations in the dual CFT and modify the boundary conditions of the bulk scalars in AdS. We find that, in addition to the usual UV divergences, the one-loop calculation suffers from a divergence originating in the limit as the loop vertices approach the AdS horizon. We show that this type of divergence is independent of the boundary coupling; making use of this we extract the finite relative variation of the imaginary part of the loop via Cutkosky rules as the boundary perturbation varies. Applying our methods to compute the effects of a time-dependent impurity to the conductivities using the replica trick in AdS/CFT, we find that generally an IR-relevant disorder reduces the conductivity and that in the extreme low frequency limit the correction due to the impurities overwhelms the planar CFT result even though it is supposedly 1/N{sup 2} suppressed. We also comment on the more physical scenario of a time-independent impurity.

  3. Stochastic inversion by ray continuation

    SciTech Connect

    Haas, A.; Viallix

    1989-05-01

    The conventional tomographic inversion consists in minimizing residuals between measured and modelled traveltimes. The process tends to be unstable and some additional constraints are required to stabilize it. The stochastic formulation generalizes the technique and sets it on firmer theoretical bases. The Stochastic Inversion by Ray Continuation (SIRC) is a probabilistic approach, which takes a priori geological information into account and uses probability distributions to characterize data correlations and errors. It makes it possible to tie uncertainties to the results. The estimated parameters are interval velocities and B-spline coefficients used to represent smoothed interfaces. Ray tracing is done by a continuation technique between source and receives. The ray coordinates are computed from one path to the next by solving a linear system derived from Fermat's principle. The main advantages are fast computations, accurate traveltimes and derivatives. The seismic traces are gathered in CMPs. For a particular CMP, several reflecting elements are characterized by their time gradient measured on the stacked section, and related to a mean emergence direction. The program capabilities are tested on a synthetic example as well as on a field example. The strategy consists in inverting the parameters for one layer, then for the next one down. An inversion step is divided in two parts. First the parameters for the layer concerned are inverted, while the parameters for the upper layers remain fixed. Then all the parameters are reinverted. The velocity-depth section computed by the program together with the corresponding errors can be used directly for the interpretation, as an initial model for depth migration or for the complete inversion program under development.

  4. Stochastic dynamics of cancer initiation

    NASA Astrophysics Data System (ADS)

    Foo, Jasmine; Leder, Kevin; Michor, Franziska

    2011-02-01

    Most human cancer types result from the accumulation of multiple genetic and epigenetic alterations in a single cell. Once the first change (or changes) have arisen, tumorigenesis is initiated and the subsequent emergence of additional alterations drives progression to more aggressive and ultimately invasive phenotypes. Elucidation of the dynamics of cancer initiation is of importance for an understanding of tumor evolution and cancer incidence data. In this paper, we develop a novel mathematical framework to study the processes of cancer initiation. Cells at risk of accumulating oncogenic mutations are organized into small compartments of cells and proliferate according to a stochastic process. During each cell division, an (epi)genetic alteration may arise which leads to a random fitness change, drawn from a probability distribution. Cancer is initiated when a cell gains a fitness sufficiently high to escape from the homeostatic mechanisms of the cell compartment. To investigate cancer initiation during a human lifetime, a 'race' between this fitness process and the aging process of the patient is considered; the latter is modeled as a second stochastic Markov process in an aging dimension. This model allows us to investigate the dynamics of cancer initiation and its dependence on the mutational fitness distribution. Our framework also provides a methodology to assess the effects of different life expectancy distributions on lifetime cancer incidence. We apply this methodology to colorectal tumorigenesis while considering life expectancy data of the US population to inform the dynamics of the aging process. We study how the probability of cancer initiation prior to death, the time until cancer initiation, and the mutational profile of the cancer-initiating cell depends on the shape of the mutational fitness distribution and life expectancy of the population.

  5. Stochastic Water Quality Optimization Using Imbedded Chance Constraints

    NASA Astrophysics Data System (ADS)

    Ellis, J. Hugh

    1987-12-01

    A chance-constrained stochastic programming model is developed for water quality optimization. It determines the least cost allocation of waste treatment plant biochemical oxygen demand (BOD) removal efficiencies, subject to probabilistic restrictions on maximum allowable instream dissolved oxygen deficit. The new model extends well beyond traditional approaches that assume streamflow is the sole random variable. In addition to streamflow, other random variables in the model are initial in-stream BOD level and dissolved oxygen (DO) deficit; waste outfall flow rates, BOD levels and DO deficits; deoxygenation k1, reaeration k2, and sedimentation-scour rate k3 coefficients of the Streeter-Phelps DO sag model; photosynthetic input-benthic depletion rates Ai, and nonpoint source BOD input rate Pi for the Camp-Dobbins extensions to the Streeter-Phelps model. These random variables appear in more highly aggregated terms which in turn form part of the probabilistic constraints of the water quality optimization model. Stochastic simulation procedures for estimating the probability density functions and covariances of these aggregated terms are discussed. A new chance-constrained programming variant, imbedded chance constraints, is presented along with an example application. In effect, this method imbeds a chance constraint within a chance constraint in a manner which is loosely associated with the distribution-free method of chance-constrained programming. It permits the selection of nonexpected value realizations of the mean and variance estimates employed in the deterministic equivalents of traditional chance-constrained models. As well, it provides a convenient mechanism for generating constraint probability response surfaces. A joint chance-constrained formulation is also presented which illustrates the possibility for prescription of an overall system reliability level, rather than reach-by-reach reliability assignment.

  6. Final Technical Report - Stochastic Nonlinear Data-Reduction Methods with Detection and Prediction of Critical Rare Event

    SciTech Connect

    Karniadakis, George Em; Vanden-Eijnden, Eric; Lin, Guang; Wan, Xiaoliang

    2013-04-03

    In this project, the collective efforts of all co-PIs aim to address three current limitations in modeling stochastic systems: (1) the inputs are mostly based on ad hoc models, (2) the number of independent parameters is very high, and (3) rare and critical events are difficult to capture with existing algorithms

  7. Multiple Stochastic Point Processes in Gene Expression

    NASA Astrophysics Data System (ADS)

    Murugan, Rajamanickam

    2008-04-01

    We generalize the idea of multiple-stochasticity in chemical reaction systems to gene expression. Using Chemical Langevin Equation approach we investigate how this multiple-stochasticity can influence the overall molecular number fluctuations. We show that the main sources of this multiple-stochasticity in gene expression could be the randomness in transcription and translation initiation times which in turn originates from the underlying bio-macromolecular recognition processes such as the site-specific DNA-protein interactions and therefore can be internally regulated by the supra-molecular structural factors such as the condensation/super-coiling of DNA. Our theory predicts that (1) in case of gene expression system, the variances ( φ) introduced by the randomness in transcription and translation initiation-times approximately scales with the degree of condensation ( s) of DNA or mRNA as φ ∝ s -6. From the theoretical analysis of the Fano factor as well as coefficient of variation associated with the protein number fluctuations we predict that (2) unlike the singly-stochastic case where the Fano factor has been shown to be a monotonous function of translation rate, in case of multiple-stochastic gene expression the Fano factor is a turn over function with a definite minimum. This in turn suggests that the multiple-stochastic processes can also be well tuned to behave like a singly-stochastic point processes by adjusting the rate parameters.

  8. Behind the Resource Domino. Part II: Allocation

    ERIC Educational Resources Information Center

    Thiemann, F. C.; Bumbarger, C. S.

    1972-01-01

    Discusses the problem of allocation and acquisition of resources from an administrative point of view. Suggests that an administrator's accountability as a leader is fixed in how efficiently and effectively resources are deployed in the organizational goal attainment efforts. (Author/DN)

  9. Ground data systems resource allocation process

    NASA Technical Reports Server (NTRS)

    Berner, Carol A.; Durham, Ralph; Reilly, Norman B.

    1989-01-01

    The Ground Data Systems Resource Allocation Process at the Jet Propulsion Laboratory provides medium- and long-range planning for the use of Deep Space Network and Mission Control and Computing Center resources in support of NASA's deep space missions and Earth-based science. Resources consist of radio antenna complexes and associated data processing and control computer networks. A semi-automated system was developed that allows operations personnel to interactively generate, edit, and revise allocation plans spanning periods of up to ten years (as opposed to only two or three weeks under the manual system) based on the relative merit of mission events. It also enhances scientific data return. A software system known as the Resource Allocation and Planning Helper (RALPH) merges the conventional methods of operations research, rule-based knowledge engineering, and advanced data base structures. RALPH employs a generic, highly modular architecture capable of solving a wide variety of scheduling and resource sequencing problems. The rule-based RALPH system has saved significant labor in resource allocation. Its successful use affirms the importance of establishing and applying event priorities based on scientific merit, and the benefit of continuity in planning provided by knowledge-based engineering. The RALPH system exhibits a strong potential for minimizing development cycles of resource and payload planning systems throughout NASA and the private sector.

  10. 45 CFR 1355.57 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare Regulations Relating to Public Welfare (Continued) OFFICE OF HUMAN DEVELOPMENT SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION ON CHILDREN, YOUTH AND FAMILIES, FOSTER CARE MAINTENANCE PAYMENTS, ADOPTION ASSISTANCE, AND CHILD AND FAMILY SERVICES GENERAL § 1355.57 Cost allocation....

  11. 42 CFR 457.228 - Cost allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false Cost allocation. 457.228 Section 457.228 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STATE CHILDREN'S HEALTH INSURANCE PROGRAMS (SCHIPs) ALLOTMENTS AND GRANTS TO STATES...

  12. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... costs, both direct and indirect, appropriately between the Refugee Resettlement Program (RRP) and other programs which it administers. (b) Within the RRP, a State must allocate costs appropriately among its CMA grant, social services grant, and any other Refugee Resettlement Program (RRP) grants which it...

  13. Issues in organ procurement, allocation, and transplantation.

    PubMed

    Nierste, Deborah

    2013-01-01

    Organ transplantation extends lives and improves health but presents complex ethical dilemmas for nurses caring for donors, recipients, and their families. This article overviews organ procurement and allocation, discusses ethical dilemmas in transplantation, and offers strategies from professional and biblical perspectives for coping with moral distress and maintaining compassionate care. PMID:23607154

  14. 50 CFR 660.320 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allocations. 660.320 Section 660.320 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE (CONTINUED) FISHERIES OFF WEST COAST STATES West Coast Groundfish Fisheries §...

  15. 42 CFR 433.34 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Department in accordance with the requirements contained in subpart E of 45 CFR part 95. Subpart E also sets... 42 Public Health 4 2010-10-01 2010-10-01 false Cost allocation. 433.34 Section 433.34 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  16. 42 CFR 457.228 - Cost allocation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accordance with the requirements contained in subpart E of 45 CFR part 95. Subpart E also sets forth the... 42 Public Health 4 2010-10-01 2010-10-01 false Cost allocation. 457.228 Section 457.228 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  17. 20 CFR 631.82 - Substate allocation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... THE JOB TRAINING PARTNERSHIP ACT Disaster Relief Employment Assistance § 631.82 Substate allocation..., within such disaster areas. The remainder of such funds may be reserved by the Governor for use, in... with such major disaster. (b) The JTPA title III program substate grantee for the disaster area...

  18. 50 CFR 660.55 - Allocations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... whiting is described in paragraph (i) of this section and in the PCGFMP. Allocation of black rockfish is... Slope RF South of 40°10′ N. lat. 63 37 Dover Sole 95 5 English Sole 95 5 Petrale Sole 95 5 Arrowtooth... management measures process. (l) Black rockfish harvest guideline. The commercial tribal harvest...

  19. 50 CFR 660.55 - Allocations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... whiting is described in paragraph (i) of this section and in the PCGFMP. Allocation of black rockfish is... Dover Sole 95 5 English Sole 95 5 Petrale Sole 95 5 Arrowtooth Flounder 95 5 Starry Flounder 50 50 Other... through the biennial harvest specifications and management measures process. (l) Black rockfish...

  20. Resource Allocation in High Schools. Final Report.

    ERIC Educational Resources Information Center

    Hartman, William T.

    This study investigated the resource allocation process--how school administrators obtain the proper resources to operate their schools, distribute the available resources among the various school programs appropriately, and manage resources for effective educational results--in four high schools during the 1984-85 school year. Information was…

  1. 20 CFR 631.82 - Substate allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Substate allocation. 631.82 Section 631.82 Employees' Benefits EMPLOYMENT AND TRAINING ADMINISTRATION, DEPARTMENT OF LABOR PROGRAMS UNDER TITLE III OF THE JOB TRAINING PARTNERSHIP ACT Disaster Relief Employment Assistance § 631.82 Substate...

  2. Discrete Resource Allocation in Visual Working Memory

    ERIC Educational Resources Information Center

    Barton, Brian; Ester, Edward F.; Awh, Edward

    2009-01-01

    Are resources in visual working memory allocated in a continuous or a discrete fashion? On one hand, flexible resource models suggest that capacity is determined by a central resource pool that can be flexibly divided such that items of greater complexity receive a larger share of resources. On the other hand, if capacity in working memory is…

  3. 45 CFR 400.13 - Cost allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Welfare Regulations Relating to Public Welfare OFFICE OF REFUGEE RESETTLEMENT, ADMINISTRATION FOR CHILDREN AND FAMILIES, DEPARTMENT OF HEALTH AND HUMAN SERVICES REFUGEE RESETTLEMENT PROGRAM Grants to States for Refugee Resettlement Award of Grants to States § 400.13 Cost allocation. (a) A State must...

  4. Allocation of Resources. SPEC Kit 31.

    ERIC Educational Resources Information Center

    Association of Research Libraries, Washington, DC. Office of Management Studies.

    This kit on resource allocation in academic and research libraries contains nine primary source documents and a concise summary of a 1976 Association of Research Libraries (ARL) survey on management of fiscal spending activities in ARL libraries. Based on responses from 70 libraries, the summary discusses 3 specific subjects within the general…

  5. 50 CFR 648.87 - Sector allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... permit sanctions pursuant to 15 CFR part 904. If an ACE allocated to a sector is not exceeded in a given... CFR part 904, each sector, permit/vessel owner, and vessel operator participating in the sector may be..., the stock-level ACL plus the carryover amount, does not exceed the stock overfishing limit. Any...

  6. Principles of allocation of health care resources.

    PubMed Central

    Knox, E G

    1978-01-01

    The methods and principles of allocating centrally provided health care resources to regions and areas are reviewed using the report of the Resource Allocation Working Party (RAWP) (Department of Health and Social Security, 1976) and the consultative document (Department of Health and Social Security, 1976a) as a basis. A range of practical problems arising from these papers (especially the report of the RAWP) is described and traced to the terms of reference. It is concluded that the RAWP misinterpreted aspects of social and administrative reality, and it failed to recognise clearly that the several principles on which it had to work conflicted with each other and demanded decisions of priority. The consequential errors led to (a) an injudicious imposition of 'objectivity' at all levels of allocation, (b) an unjustified insistence that the same method be used at each administrative level in an additive and transitive manner, (c) the exclusion of general practitioner services from their considerations, (d) a failure to delineate those decisions which are in fact political decisions, thus to concatenate them, inappropriately, with technical and professional issues. The main requirement in a revised system is for a mechanism which allocates different priorities to different principles at each appropriate administrative and distributive level, and adapts the working methods of each tier to meet separately defined objectives. PMID:262585

  7. Ethics and resource allocation: an economist's view.

    PubMed

    McGuire, A

    1986-01-01

    This paper debates some of the issues involved in attempting to apply economic analysis to the health care sector when medical ethics plays such an important part in determining the allocation of resources in that sector. Two distinct ethical positions are highlighted as being fundamental to the understanding of resource allocation in this sector -- deontological and utilitarian theories of ethics. It is argued that medical ethics are often narrowly conceived in that there is a tendency for the individual, rather than society at large, to form the focal point of the production of the service "health care'. Thus medical ethics have been dominated by individualistic ethical coded which do not fully consider questions relating to resource allocation at a social level. It is further argued that the structure of the health care sector augments these "individualistic' ethics. It is also suggested that different actors in the health care sector address questions of resource allocation with respect to different time periods, and that this serves to further enhance the influence of "individualistic' ethical codes in this sector.

  8. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration... Coastal Zone Act Reauthorization Amendments of 1990, 1 to 1 for any fiscal year. (2) For programs...

  9. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration... Coastal Zone Act Reauthorization Amendments of 1990, 1 to 1 for any fiscal year. (2) For programs...

  10. 15 CFR 923.110 - Allocation formula.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT COASTAL ZONE MANAGEMENT PROGRAM REGULATIONS Allocation of Section 306 Program Administration... Coastal Zone Act Reauthorization Amendments of 1990, 1 to 1 for any fiscal year. (2) For programs...

  11. Resource Allocation Patterns and Student Achievement

    ERIC Educational Resources Information Center

    James, Lori; Pate, James; Leech, Donald; Martin, Ellice; Brockmeier, Lantry; Dees, Elizabeth

    2011-01-01

    This quantitative research study was designed to examine the relationship between system resource allocation patterns and student achievement, as measured by eighth grade Criterion-Referenced Competency Test (CRCT) mathematics, eighth grade CRCT reading, eleventh grade Georgia High School Graduation Test (GHSGT) mathematics, eleventh grade and…

  12. 23 CFR 660.107 - Allocations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 23 Highways 1 2012-04-01 2012-04-01 false Allocations. 660.107 Section 660.107 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS SPECIAL PROGRAMS... approved Federal Lands Coordinated Technology Implementation Program studies....

  13. 24 CFR 574.130 - Formula allocations.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...-five percent is allocated among qualifying cities, but not States, where the per capita incidence of...'s with higher than average per capita incidence of AIDS. The high incidence factor is computed by... the high incidence factors for all EMSA's with higher than average per capita incidence of AIDS....

  14. 24 CFR 574.130 - Formula allocations.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...-five percent is allocated among qualifying cities, but not States, where the per capita incidence of...'s with higher than average per capita incidence of AIDS. The high incidence factor is computed by... the high incidence factors for all EMSA's with higher than average per capita incidence of AIDS....

  15. Kolmogorov-Zakharov spectrum in AdS gravitational collapse.

    PubMed

    de Oliveira, H P; Pando Zayas, Leopoldo A; Rodrigues, E L

    2013-08-01

    We study black hole formation during the gravitational collapse of a massless scalar field in asymptotically D-dimensional anti-de Sitter AdS(D) spacetimes for D = 4, 5. We conclude that spherically symmetric gravitational collapse in asymptotically AdS spaces is turbulent and characterized by a Kolmogorov-Zakharov spectrum. Namely, we find that after an initial period of weakly nonlinear evolution, there is a regime where the power spectrum of the Ricci scalar evolves as ω(-s) with the frequency, ω, and s ≈ 1.7 ± 0.1.

  16. Solving stochastic epidemiological models using computer algebra

    NASA Astrophysics Data System (ADS)

    Hincapie, Doracelly; Ospina, Juan

    2011-06-01

    Mathematical modeling in Epidemiology is an important tool to understand the ways under which the diseases are transmitted and controlled. The mathematical modeling can be implemented via deterministic or stochastic models. Deterministic models are based on short systems of non-linear ordinary differential equations and the stochastic models are based on very large systems of linear differential equations. Deterministic models admit complete, rigorous and automatic analysis of stability both local and global from which is possible to derive the algebraic expressions for the basic reproductive number and the corresponding epidemic thresholds using computer algebra software. Stochastic models are more difficult to treat and the analysis of their properties requires complicated considerations in statistical mathematics. In this work we propose to use computer algebra software with the aim to solve epidemic stochastic models such as the SIR model and the carrier-borne model. Specifically we use Maple to solve these stochastic models in the case of small groups and we obtain results that do not appear in standard textbooks or in the books updated on stochastic models in epidemiology. From our results we derive expressions which coincide with those obtained in the classical texts using advanced procedures in mathematical statistics. Our algorithms can be extended for other stochastic models in epidemiology and this shows the power of computer algebra software not only for analysis of deterministic models but also for the analysis of stochastic models. We also perform numerical simulations with our algebraic results and we made estimations for the basic parameters as the basic reproductive rate and the stochastic threshold theorem. We claim that our algorithms and results are important tools to control the diseases in a globalized world.

  17. Rhazes (865-925 AD), the icon of Persian cardiology.

    PubMed

    Nezhad, Golnoush Sadat Mahmoudi; Dalfardi, Behnam

    2014-12-20

    For many long centuries, the function of the human cardiovascular system was an important issue among scholars of different eras and areas. Abubakr Muhammad ibn Zakariyya al-Razi (865-925 AD), known by the Latin name Rhazes, was one of the scholars concerned with this issue. This physician is recognized as the first great scientist of the Golden Age of Islamic Medicine (9th-12th centuries AD). He authored Kitab al-Mansuri (Liber Al-Mansuri), a ten-volume medical encyclopedia that covers a large number of medical subjects. The first chapter of this book is allocated to human anatomy and functions. In this article, we review the chapter from Al-Mansuri that deals with Rhazes' views on the cardiovascular system. PMID:25465822

  18. Stochastic system identification in structural dynamics

    USGS Publications Warehouse

    Safak, Erdal

    1988-01-01

    Recently, new identification methods have been developed by using the concept of optimal-recursive filtering and stochastic approximation. These methods, known as stochastic identification, are based on the statistical properties of the signal and noise, and do not require the assumptions of current methods. The criterion for stochastic system identification is that the difference between the recorded output and the output from the identified system (i.e., the residual of the identification) should be equal to white noise. In this paper, first a brief review of the theory is given. Then, an application of the method is presented by using ambient vibration data from a nine-story building.

  19. Connecting deterministic and stochastic metapopulation models.

    PubMed

    Barbour, A D; McVinish, R; Pollett, P K

    2015-12-01

    In this paper, we study the relationship between certain stochastic and deterministic versions of Hanski's incidence function model and the spatially realistic Levins model. We show that the stochastic version can be well approximated in a certain sense by the deterministic version when the number of habitat patches is large, provided that the presence or absence of individuals in a given patch is influenced by a large number of other patches. Explicit bounds on the deviation between the stochastic and deterministic models are given. PMID:25735440

  20. Stochastic deformation of a thermodynamic symplectic structure.

    PubMed

    Kazinski, P O

    2009-01-01

    A stochastic deformation of a thermodynamic symplectic structure is studied. The stochastic deformation is analogous to the deformation of an algebra of observables such as deformation quantization, but for an imaginary deformation parameter (the Planck constant). Gauge symmetries of thermodynamics and corresponding stochastic mechanics, which describes fluctuations of a thermodynamic system, are revealed and gauge fields are introduced. A physical interpretation to the gauge transformations and gauge fields is given. An application of the formalism to a description of systems with distributed parameters in a local thermodynamic equilibrium is considered.

  1. Stochastic deformation of a thermodynamic symplectic structure

    NASA Astrophysics Data System (ADS)

    Kazinski, P. O.

    2009-01-01

    A stochastic deformation of a thermodynamic symplectic structure is studied. The stochastic deformation is analogous to the deformation of an algebra of observables such as deformation quantization, but for an imaginary deformation parameter (the Planck constant). Gauge symmetries of thermodynamics and corresponding stochastic mechanics, which describes fluctuations of a thermodynamic system, are revealed and gauge fields are introduced. A physical interpretation to the gauge transformations and gauge fields is given. An application of the formalism to a description of systems with distributed parameters in a local thermodynamic equilibrium is considered.

  2. Stochastic string models with continuous semimartingales

    NASA Astrophysics Data System (ADS)

    Bueno-Guerrero, Alberto; Moreno, Manuel; Navas, Javier F.

    2015-09-01

    This paper reformulates the stochastic string model of Santa-Clara and Sornette using stochastic calculus with continuous semimartingales. We present some new results, such as: (a) the dynamics of the short-term interest rate, (b) the PDE that must be satisfied by the bond price, and (c) an analytic expression for the price of a European bond call option. Additionally, we clarify some important features of the stochastic string model and show its relevance to price derivatives and the equivalence with an infinite dimensional HJM model to price European options.

  3. Functional Stochastic Resonance in the Human Brain: Noise Induced Sensitization of Baroreflex System

    NASA Astrophysics Data System (ADS)

    Hidaka, Ichiro; Nozaki, Daichi; Yamamoto, Yoshiharu

    2000-10-01

    We demonstrate experimentally that noise can enhance the homeostatic function in the human blood pressure regulatory system. The results show that the compensatory heart rate response to the weak periodic signal introduced at the venous blood pressure receptor is optimized by adding noise to the arterial blood pressure receptor. We conclude that this functional stochastic resonance most likely results from the interaction of noise with signal in the brain stem, where the neuronal inputs from these two different receptors first join together.

  4. Semiclassical Virasoro blocks from AdS3 gravity

    NASA Astrophysics Data System (ADS)

    Hijano, Eliot; Kraus, Per; Perlmutter, Eric; Snively, River

    2015-12-01

    We present a unified framework for the holographic computation of Virasoro conformal blocks at large central charge. In particular, we provide bulk constructions that correctly reproduce all semiclassical Virasoro blocks that are known explicitly from conformal field theory computations. The results revolve around the use of geodesic Witten diagrams, recently introduced in [1], evaluated in locally AdS3 geometries generated by backreaction of heavy operators. We also provide an alternative computation of the heavy-light semiclassical block — in which two external operators become parametrically heavy — as a certain scattering process involving higher spin gauge fields in AdS3; this approach highlights the chiral nature of Virasoro blocks. These techniques may be systematically extended to compute corrections to these blocks and to interpolate amongst the different semiclassical regimes.

  5. AdS6 solutions of type II supergravity

    NASA Astrophysics Data System (ADS)

    Apruzzi, Fabio; Fazzi, Marco; Passias, Achilleas; Rosa, Dario; Tomasiello, Alessandro

    2014-11-01

    Very few AdS6 × M 4 supersymmetric solutions are known: one in massive IIA, and two IIB solutions dual to it. The IIA solution is known to be unique; in this paper, we use the pure spinor approach to give a classification for IIB supergravity. We reduce the problem to two PDEs on a two-dimensional space Σ. M 4 is then a fibration of S 2 over Σ; the metric and fluxes are completely determined in terms of the solution to the PDEs. The results seem likely to accommodate near-horizon limits of ( p, q)-fivebrane webs studied in the literature as a source of CFT5's. We also show that there are no AdS6 solutions in eleven-dimensional supergravity.

  6. Postural Stability in Parkinson's Disease Patients Is Improved after Stochastic Resonance Therapy.

    PubMed

    Kaut, Oliver; Brenig, Daniel; Marek, Milena; Allert, Niels; Wüllner, Ullrich

    2016-01-01

    Background. Postural instability in Parkinson's disease (PD) increases the risk of falls and is not improved by pharmacological therapy. Objective. We performed a double-blind, randomized sham-controlled study to test the effects of stochastic resonance (whole body vibration) therapy on postural stability in PD. Methods. Fifty-six PD participants were allocated to either experimental or sham groups. The experimental group received four series of vibration over eight days, with each series consisting of six stimulus trains of 60-second duration using a randomized whole body vibration. Participants allocated to the control group received a sham treatment. Results. Within-group analysis revealed that postural stability in the experimental group improved by 17.5% (p = 0.005) comparing experimental and sham groups. The between-group analysis of change after treatment comparing both groups also showed a significant improvement of postural stability (p = 0.03). Only in the within-group analysis several items were improved after Bonferroni correction, too, rigor 41.6% (p = 0.001), bradykinesia 23.7% (p = 0.001), tremor 30.8% (p = 0.006), and UPDRSIII sum score 23.9% (p = 0.000), but did not reach the level of significance in the between-group analysis. Conclusions. Stochastic resonance therapy significantly enhanced postural stability even in individuals with increased risk of falling. Thus it offers a potential supplementation to canonical treatments of PD.

  7. Interactive two-stage stochastic fuzzy programming for water resources management.

    PubMed

    Wang, S; Huang, G H

    2011-08-01

    In this study, an interactive two-stage stochastic fuzzy programming (ITSFP) approach has been developed through incorporating an interactive fuzzy resolution (IFR) method within an inexact two-stage stochastic programming (ITSP) framework. ITSFP can not only tackle dual uncertainties presented as fuzzy boundary intervals that exist in the objective function and the left- and right-hand sides of constraints, but also permit in-depth analyses of various policy scenarios that are associated with different levels of economic penalties when the promised policy targets are violated. A management problem in terms of water resources allocation has been studied to illustrate applicability of the proposed approach. The results indicate that a set of solutions under different feasibility degrees has been generated for planning the water resources allocation. They can help the decision makers (DMs) to conduct in-depth analyses of tradeoffs between economic efficiency and constraint-violation risk, as well as enable them to identify, in an interactive way, a desired compromise between satisfaction degree of the goal and feasibility of the constraints (i.e., risk of constraint violation).

  8. Conserved higher-spin charges in AdS4

    NASA Astrophysics Data System (ADS)

    Gelfond, O. A.; Vasiliev, M. A.

    2016-03-01

    Gauge invariant conserved conformal currents built from massless fields of all spins in 4d Minkowski space-time and AdS4 are described in the unfolded dynamics approach. The current cohomology associated with non-zero conserved charges is found. The resulting list of charges is shown to match the space of parameters of the conformal higher-spin symmetry algebra in four dimensions.

  9. On information loss in AdS3/CFT2

    DOE PAGES

    Fitzpatrick, A. Liam; Kaplan, Jared; Li, Daliang; Wang, Junpu

    2016-05-18

    We discuss information loss from black hole physics in AdS3, focusing on two sharp signatures infecting CFT2 correlators at large central charge c: ‘forbidden singularities’ arising from Euclidean-time periodicity due to the effective Hawking temperature, and late-time exponential decay in the Lorentzian region. We study an infinite class of examples where forbidden singularities can be resolved by non-perturbative effects at finite c, and we show that the resolution has certain universal features that also apply in the general case. Analytically continuing to the Lorentzian regime, we find that the non-perturbative effects that resolve forbidden singularities qualitatively change the behavior ofmore » correlators at times t ~SBH, the black hole entropy. This may resolve the exponential decay of correlators at late times in black hole backgrounds. By Borel resumming the 1/c expansion of exact examples, we explicitly identify ‘information-restoring’ effects from heavy states that should correspond to classical solutions in AdS3. Lastly, our results suggest a line of inquiry towards a more precise formulation of the gravitational path integral in AdS3.« less

  10. Stochastic pump effect and geometric phases in dissipative and stochastic systems

    SciTech Connect

    Sinitsyn, Nikolai

    2008-01-01

    The success of Berry phases in quantum mechanics stimulated the study of similar phenomena in other areas of physics, including the theory of living cell locomotion and motion of patterns in nonlinear media. More recently, geometric phases have been applied to systems operating in a strongly stochastic environment, such as molecular motors. We discuss such geometric effects in purely classical dissipative stochastic systems and their role in the theory of the stochastic pump effect (SPE).

  11. A Fractional Order Recovery SIR Model from a Stochastic Process.

    PubMed

    Angstmann, C N; Henry, B I; McGann, A V

    2016-03-01

    Over the past several decades, there has been a proliferation of epidemiological models with ordinary derivatives replaced by fractional derivatives in an ad hoc manner. These models may be mathematically interesting, but their relevance is uncertain. Here we develop an SIR model for an epidemic, including vital dynamics, from an underlying stochastic process. We show how fractional differential operators arise naturally in these models whenever the recovery time from the disease is power-law distributed. This can provide a model for a chronic disease process where individuals who are infected for a long time are unlikely to recover. The fractional order recovery model is shown to be consistent with the Kermack-McKendrick age-structured SIR model, and it reduces to the Hethcote-Tudor integral equation SIR model. The derivation from a stochastic process is extended to discrete time, providing a stable numerical method for solving the model equations. We have carried out simulations of the fractional order recovery model showing convergence to equilibrium states. The number of infecteds in the endemic equilibrium state increases as the fractional order of the derivative tends to zero. PMID:26940822

  12. Fisher-information condition for enhanced signal detection via stochastic resonance.

    PubMed

    Duan, Fabing; Chapeau-Blondeau, François; Abbott, Derek

    2011-11-01

    Various situations where a signal is enhanced by noise through stochastic resonance are now known. This paper contributes to determining general conditions under which improvement by noise can be a priori decided as feasible or not. We focus on the detection of a known signal in additive white noise. Under the assumptions of a weak signal and a sufficiently large sample size, it is proved, with an inequality based on the Fisher information, that improvement by adding noise is never possible, generically, in these conditions. However, under less restrictive conditions, an example of signal detection is shown with favorable action of adding noise.

  13. A risk-based interactive multi-stage stochastic programming approach for water resources planning under dual uncertainties

    NASA Astrophysics Data System (ADS)

    Wang, Y. Y.; Huang, G. H.; Wang, S.; Li, W.; Guan, P. B.

    2016-08-01

    In this study, a risk-based interactive multi-stage stochastic programming (RIMSP) approach is proposed through incorporating the fractile criterion method and chance-constrained programming within a multi-stage decision-making framework. RIMSP is able to deal with dual uncertainties expressed as random boundary intervals that exist in the objective function and constraints. Moreover, RIMSP is capable of reflecting dynamics of uncertainties, as well as the trade-off between the total net benefit and the associated risk. A water allocation problem is used to illustrate applicability of the proposed methodology. A set of decision alternatives with different combinations of risk levels applied to the objective function and constraints can be generated for planning the water resources allocation system. The results can help decision makers examine potential interactions between risks related to the stochastic objective function and constraints. Furthermore, a number of solutions can be obtained under different water policy scenarios, which are useful for decision makers to formulate an appropriate policy under uncertainty. The performance of RIMSP is analyzed and compared with an inexact multi-stage stochastic programming (IMSP) method. Results of comparison experiment indicate that RIMSP is able to provide more robust water management alternatives with less system risks in comparison with IMSP.

  14. Bootstrap performance profiles in stochastic algorithms assessment

    SciTech Connect

    Costa, Lino; Espírito Santo, Isabel A.C.P.; Oliveira, Pedro

    2015-03-10

    Optimization with stochastic algorithms has become a relevant research field. Due to its stochastic nature, its assessment is not straightforward and involves integrating accuracy and precision. Performance profiles for the mean do not show the trade-off between accuracy and precision, and parametric stochastic profiles require strong distributional assumptions and are limited to the mean performance for a large number of runs. In this work, bootstrap performance profiles are used to compare stochastic algorithms for different statistics. This technique allows the estimation of the sampling distribution of almost any statistic even with small samples. Multiple comparison profiles are presented for more than two algorithms. The advantages and drawbacks of each assessment methodology are discussed.

  15. Perspective: Stochastic algorithms for chemical kinetics

    NASA Astrophysics Data System (ADS)

    Gillespie, Daniel T.; Hellander, Andreas; Petzold, Linda R.

    2013-05-01

    We outline our perspective on stochastic chemical kinetics, paying particular attention to numerical simulation algorithms. We first focus on dilute, well-mixed systems, whose description using ordinary differential equations has served as the basis for traditional chemical kinetics for the past 150 years. For such systems, we review the physical and mathematical rationale for a discrete-stochastic approach, and for the approximations that need to be made in order to regain the traditional continuous-deterministic description. We next take note of some of the more promising strategies for dealing stochastically with stiff systems, rare events, and sensitivity analysis. Finally, we review some recent efforts to adapt and extend the discrete-stochastic approach to systems that are not well-mixed. In that currently developing area, we focus mainly on the strategy of subdividing the system into well-mixed subvolumes, and then simulating diffusional transfers of reactant molecules between adjacent subvolumes together with chemical reactions inside the subvolumes.

  16. Stochasticity in plant cellular growth and patterning

    PubMed Central

    Meyer, Heather M.; Roeder, Adrienne H. K.

    2014-01-01

    Plants, along with other multicellular organisms, have evolved specialized regulatory mechanisms to achieve proper tissue growth and morphogenesis. During development, growing tissues generate specialized cell types and complex patterns necessary for establishing the function of the organ. Tissue growth is a tightly regulated process that yields highly reproducible outcomes. Nevertheless, the underlying cellular and molecular behaviors are often stochastic. Thus, how does stochasticity, together with strict genetic regulation, give rise to reproducible tissue development? This review draws examples from plants as well as other systems to explore stochasticity in plant cell division, growth, and patterning. We conclude that stochasticity is often needed to create small differences between identical cells, which are amplified and stabilized by genetic and mechanical feedback loops to begin cell differentiation. These first few differentiating cells initiate traditional patterning mechanisms to ensure regular development. PMID:25250034

  17. Communication: Embedded fragment stochastic density functional theory

    SciTech Connect

    Neuhauser, Daniel; Baer, Roi; Rabani, Eran

    2014-07-28

    We develop a method in which the electronic densities of small fragments determined by Kohn-Sham density functional theory (DFT) are embedded using stochastic DFT to form the exact density of the full system. The new method preserves the scaling and the simplicity of the stochastic DFT but cures the slow convergence that occurs when weakly coupled subsystems are treated. It overcomes the spurious charge fluctuations that impair the applications of the original stochastic DFT approach. We demonstrate the new approach on a fullerene dimer and on clusters of water molecules and show that the density of states and the total energy can be accurately described with a relatively small number of stochastic orbitals.

  18. Communication: Embedded fragment stochastic density functional theory

    NASA Astrophysics Data System (ADS)

    Neuhauser, Daniel; Baer, Roi; Rabani, Eran

    2014-07-01

    We develop a method in which the electronic densities of small fragments determined by Kohn-Sham density functional theory (DFT) are embedded using stochastic DFT to form the exact density of the full system. The new method preserves the scaling and the simplicity of the stochastic DFT but cures the slow convergence that occurs when weakly coupled subsystems are treated. It overcomes the spurious charge fluctuations that impair the applications of the original stochastic DFT approach. We demonstrate the new approach on a fullerene dimer and on clusters of water molecules and show that the density of states and the total energy can be accurately described with a relatively small number of stochastic orbitals.

  19. Perspective: Stochastic algorithms for chemical kinetics.

    PubMed

    Gillespie, Daniel T; Hellander, Andreas; Petzold, Linda R

    2013-05-01

    We outline our perspective on stochastic chemical kinetics, paying particular attention to numerical simulation algorithms. We first focus on dilute, well-mixed systems, whose description using ordinary differential equations has served as the basis for traditional chemical kinetics for the past 150 years. For such systems, we review the physical and mathematical rationale for a discrete-stochastic approach, and for the approximations that need to be made in order to regain the traditional continuous-deterministic description. We next take note of some of the more promising strategies for dealing stochastically with stiff systems, rare events, and sensitivity analysis. Finally, we review some recent efforts to adapt and extend the discrete-stochastic approach to systems that are not well-mixed. In that currently developing area, we focus mainly on the strategy of subdividing the system into well-mixed subvolumes, and then simulating diffusional transfers of reactant molecules between adjacent subvolumes together with chemical reactions inside the subvolumes.

  20. Stochastic differential equation model to Prendiville processes

    SciTech Connect

    Granita; Bahar, Arifah

    2015-10-22

    The Prendiville process is another variation of the logistic model which assumes linearly decreasing population growth rate. It is a continuous time Markov chain (CTMC) taking integer values in the finite interval. The continuous time Markov chain can be approximated by stochastic differential equation (SDE). This paper discusses the stochastic differential equation of Prendiville process. The work started with the forward Kolmogorov equation in continuous time Markov chain of Prendiville process. Then it was formulated in the form of a central-difference approximation. The approximation was then used in Fokker-Planck equation in relation to the stochastic differential equation of the Prendiville process. The explicit solution of the Prendiville process was obtained from the stochastic differential equation. Therefore, the mean and variance function of the Prendiville process could be easily found from the explicit solution.

  1. A mechanistic stochastic framework for regulating bacterial cell division

    PubMed Central

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A.; Singh, Abhyudai

    2016-01-01

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size. PMID:27456660

  2. Stochastic Resonance in Time-to-Contact Judgments

    NASA Astrophysics Data System (ADS)

    Ranjit, Manish; Gazula, Harshvardhan; Hsiang, Simon M.; Delucia, Patricia R.

    2015-04-01

    Stochastic resonance (SR) is a counterintuitive phenomenon in which additive noise enhances performance of a nonlinear system. Previous studies demonstrated SR effect on human tactile sensitivity by adding noise of same modality and cross modality. Similarly, enhancement of human hearing through additive noise has been studied. In this study, we investigate the effect of noise in visual perception, specifically time-to-contact (TTC) judgments. This study explores four research questions: (1) Does noise help in TTC judgments? (2) How does noise affect speed and accuracy of TTC judgments? (3) Does cross modal noise help in TTC judgments? (4) How does cross modal noise affect speed and accuracy of TTC judgments? Through simulation, we show that noise in optical cue can enhance weak signals. We also demonstrate that noise can improve speed of TTC judgments at the expense of accuracy. Similarly, we demonstrate SR by adding noise of cross modality. These findings provide plausible hypotheses regarding how much noise should be added to enhance TTC judgments.

  3. A mechanistic stochastic framework for regulating bacterial cell division.

    PubMed

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A; Singh, Abhyudai

    2016-01-01

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size. PMID:27456660

  4. A mechanistic stochastic framework for regulating bacterial cell division.

    PubMed

    Ghusinga, Khem Raj; Vargas-Garcia, Cesar A; Singh, Abhyudai

    2016-07-26

    How exponentially growing cells maintain size homeostasis is an important fundamental problem. Recent single-cell studies in prokaryotes have uncovered the adder principle, where cells add a fixed size (volume) from birth to division, irrespective of their size at birth. To mechanistically explain the adder principle, we consider a timekeeper protein that begins to get stochastically expressed after cell birth at a rate proportional to the volume. Cell-division time is formulated as the first-passage time for protein copy numbers to hit a fixed threshold. Consistent with data, the model predicts that the noise in division timing increases with size at birth. Intriguingly, our results show that the distribution of the volume added between successive cell-division events is independent of the newborn cell size. This was dramatically seen in experimental studies, where histograms of the added volume corresponding to different newborn sizes collapsed on top of each other. The model provides further insights consistent with experimental observations: the distribution of the added volume when scaled by its mean becomes invariant of the growth rate. In summary, our simple yet elegant model explains key experimental findings and suggests a mechanism for regulating both the mean and fluctuations in cell-division timing for controlling size.

  5. THE 1985 NAPAP EMISSIONS INVENTORY: DEVELOPMENT OF SPECIES ALLOCATION FACTORS

    EPA Science Inventory

    The report describes the methodologies and data bases used to develop species allocation factors and data processing software used to develop the 1985 National Acid Precipitation Assessment Program (NAPAP) Modelers' Emissions Inventory (Version 2). Species allocation factors were...

  6. Stochastic description of quantum Brownian dynamics

    NASA Astrophysics Data System (ADS)

    Yan, Yun-An; Shao, Jiushu

    2016-08-01

    Classical Brownian motion has well been investigated since the pioneering work of Einstein, which inspired mathematicians to lay the theoretical foundation of stochastic processes. A stochastic formulation for quantum dynamics of dissipative systems described by the system-plus-bath model has been developed and found many applications in chemical dynamics, spectroscopy, quantum transport, and other fields. This article provides a tutorial review of the stochastic formulation for quantum dissipative dynamics. The key idea is to decouple the interaction between the system and the bath by virtue of the Hubbard-Stratonovich transformation or Itô calculus so that the system and the bath are not directly entangled during evolution, rather they are correlated due to the complex white noises introduced. The influence of the bath on the system is thereby defined by an induced stochastic field, which leads to the stochastic Liouville equation for the system. The exact reduced density matrix can be calculated as the stochastic average in the presence of bath-induced fields. In general, the plain implementation of the stochastic formulation is only useful for short-time dynamics, but not efficient for long-time dynamics as the statistical errors go very fast. For linear and other specific systems, the stochastic Liouville equation is a good starting point to derive the master equation. For general systems with decomposable bath-induced processes, the hierarchical approach in the form of a set of deterministic equations of motion is derived based on the stochastic formulation and provides an effective means for simulating the dissipative dynamics. A combination of the stochastic simulation and the hierarchical approach is suggested to solve the zero-temperature dynamics of the spin-boson model. This scheme correctly describes the coherent-incoherent transition (Toulouse limit) at moderate dissipation and predicts a rate dynamics in the overdamped regime. Challenging problems

  7. Assessing the performance of life-cycle portfolio allocation strategies for retirement saving: a simulation study.

    PubMed

    Bridges, Benjamin; Gesumaria, Robert; Leonesio, Michael V

    2010-01-01

    This article examines the performance of four life-cycle portfolio allocation strategies through stochastic simulation based on observed U.S. asset returns during 1926-2008. Annual worker contributions to retirement savings accounts are based on the actual lifetime earnings histories maintained by the Social Security Administration for 12,871 workers born during 1915-1942. Each strategy's performance is evaluated primarily on the basis of the distributions of internal rates of return on investments calculated at the time of retirement. Comparisons are made with the performance of four other investment strategies that vary in terms of their exposure to stock and bond market risk. Life-cycle plans with larger portfolio weights assigned to equities have higher average returns, but those gains come at the cost of increased risk of infrequent bad outcomes.

  8. A Framework for Incorporating General Domain Knowledge into Latent Dirichlet Allocation using First-Order Logic

    SciTech Connect

    Andrzejewski, D; Zhu, X; Craven, M; Recht, B

    2011-01-18

    Topic models have been used successfully for a variety of problems, often in the form of application-specific extensions of the basic Latent Dirichlet Allocation (LDA) model. Because deriving these new models in order to encode domain knowledge can be difficult and time-consuming, we propose the Fold-all model, which allows the user to specify general domain knowledge in First-Order Logic (FOL). However, combining topic modeling with FOL can result in inference problems beyond the capabilities of existing techniques. We have therefore developed a scalable inference technique using stochastic gradient descent which may also be useful to the Markov Logic Network (MLN) research community. Experiments demonstrate the expressive power of Fold-all, as well as the scalability of our proposed inference method.

  9. ADS/CFT and QCD

    SciTech Connect

    Brodsky, Stanley J.; de Teramond, Guy F.; /Costa Rica U. /SLAC

    2007-02-21

    The AdS/CFT correspondence between string theory in AdS space and conformal .eld theories in physical spacetime leads to an analytic, semi-classical model for strongly-coupled QCD which has scale invariance and dimensional counting at short distances and color confinement at large distances. Although QCD is not conformally invariant, one can nevertheless use the mathematical representation of the conformal group in five-dimensional anti-de Sitter space to construct a first approximation to the theory. The AdS/CFT correspondence also provides insights into the inherently non-perturbative aspects of QCD, such as the orbital and radial spectra of hadrons and the form of hadronic wavefunctions. In particular, we show that there is an exact correspondence between the fifth-dimensional coordinate of AdS space z and a specific impact variable {zeta} which measures the separation of the quark and gluonic constituents within the hadron in ordinary space-time. This connection allows one to compute the analytic form of the frame-independent light-front wavefunctions, the fundamental entities which encode hadron properties and allow the computation of decay constants, form factors, and other exclusive scattering amplitudes. New relativistic lightfront equations in ordinary space-time are found which reproduce the results obtained using the 5-dimensional theory. The effective light-front equations possess remarkable algebraic structures and integrability properties. Since they are complete and orthonormal, the AdS/CFT model wavefunctions can also be used as a basis for the diagonalization of the full light-front QCD Hamiltonian, thus systematically improving the AdS/CFT approximation.

  10. Stochastic resonance in the brusselator model

    PubMed

    Osipov; Ponizovskaya

    2000-04-01

    Using the Brusselator model, we show that in a simple dynamical system small noise can be converted into stochastic spikewise oscillations of huge amplitude (bursting noises) in the vicinity of a Hopf bifurcation. Small periodic signals with amplitude several times less than the noise intensity transform these stochastic oscillations into quasiperiodic large-amplitude spikewise oscillations or small-amplitude quasiharmonic oscillations, depending on the signal form. PMID:11088262

  11. Structural model uncertainty in stochastic simulation

    SciTech Connect

    McKay, M.D.; Morrison, J.D.

    1997-09-01

    Prediction uncertainty in stochastic simulation models can be described by a hierarchy of components: stochastic variability at the lowest level, input and parameter uncertainty at a higher level, and structural model uncertainty at the top. It is argued that a usual paradigm for analysis of input uncertainty is not suitable for application to structural model uncertainty. An approach more likely to produce an acceptable methodology for analyzing structural model uncertainty is one that uses characteristics specific to the particular family of models.

  12. Desynchronization of stochastically synchronized chemical oscillators

    SciTech Connect

    Snari, Razan; Tinsley, Mark R. E-mail: kshowalt@wvu.edu; Faramarzi, Sadegh; Showalter, Kenneth E-mail: kshowalt@wvu.edu; Wilson, Dan; Moehlis, Jeff; Netoff, Theoden Ivan

    2015-12-15

    Experimental and theoretical studies are presented on the design of perturbations that enhance desynchronization in populations of oscillators that are synchronized by periodic entrainment. A phase reduction approach is used to determine optimal perturbation timing based upon experimentally measured phase response curves. The effectiveness of the perturbation waveforms is tested experimentally in populations of periodically and stochastically synchronized chemical oscillators. The relevance of the approach to therapeutic methods for disrupting phase coherence in groups of stochastically synchronized neuronal oscillators is discussed.

  13. A discussion of bunched beam stochastic cooling

    SciTech Connect

    Neuffer, David; /Fermilab

    2005-08-01

    The analysis of Herr and Mohl[1] is used as a basis for a discussion of bunched beam cooling in the Fermilab recycler and the Tevatron. Differences between the two cooling regimes are discussed. Criteria discussed in that paper imply the failure of stochastic cooling in the Tevatron while permitting the success of stochastic cooling in the Recycler. These ''predictions'' are in agreement with observations.

  14. Stochastic differential games with inside information

    NASA Astrophysics Data System (ADS)

    Draouil, Olfa; Øksendal, Bernt

    2016-08-01

    We study stochastic differential games of jump diffusions, where the players have access to inside information. Our approach is based on anticipative stochastic calculus, white noise, Hida-Malliavin calculus, forward integrals and the Donsker delta functional. We obtain a characterization of Nash equilibria of such games in terms of the corresponding Hamiltonians. This is used to study applications to insider games in finance, specifically optimal insider consumption and optimal insider portfolio under model uncertainty.

  15. Behavioral Stochastic Resonance within the Human Brain

    NASA Astrophysics Data System (ADS)

    Kitajo, Keiichi; Nozaki, Daichi; Ward, Lawrence M.; Yamamoto, Yoshiharu

    2003-05-01

    We provide the first evidence that stochastic resonance within the human brain can enhance behavioral responses to weak sensory inputs. We asked subjects to adjust handgrip force to a slowly changing, subthreshold gray level signal presented to their right eye. Behavioral responses were optimized by presenting randomly changing gray levels separately to the left eye. The results indicate that observed behavioral stochastic resonance was mediated by neural activity within the human brain where the information from both eyes converges.

  16. Complexity and synchronization in stochastic chaotic systems

    NASA Astrophysics Data System (ADS)

    Son Dang, Thai; Palit, Sanjay Kumar; Mukherjee, Sayan; Hoang, Thang Manh; Banerjee, Santo

    2016-02-01

    We investigate the complexity of a hyperchaotic dynamical system perturbed by noise and various nonlinear speech and music signals. The complexity is measured by the weighted recurrence entropy of the hyperchaotic and stochastic systems. The synchronization phenomenon between two stochastic systems with complex coupling is also investigated. These criteria are tested on chaotic and perturbed systems by mean conditional recurrence and normalized synchronization error. Numerical results including surface plots, normalized synchronization errors, complexity variations etc show the effectiveness of the proposed analysis.

  17. Recently fixed carbon allocation in strawberry plants and concurrent inorganic nitrogen uptake through arbuscular mycorrhizal fungi.

    PubMed

    Tomè, Elisabetta; Tagliavini, Massimo; Scandellari, Francesca

    2015-05-01

    Most crop species form a symbiotic association with arbuscular mycorrhizal (AM) fungi, receiving plant photosynthate and exchanging nutrients from the soil. The plant carbon (C) allocation to AM fungi and the nitrogen feedback are rarely studied together. In this study, a dual (13)CO2 and (15)NH4(15)NO3 pulse labeling experiment was carried out to determine the allocation of recent photosynthates to mycorrhizal hyphae and the translocation of N absorbed by hyphae to strawberry plants. Plants were grown in pots in which a 50 μm mesh net allowed the physical separation of the mycorrhizal hyphae from the roots in one portion of the pot. An inorganic source of (15)N was added to the hyphal compartment at the same time of the (13)CO2 pulse labeling. One and seven days after pulse labeling, the plants were destructively harvested and the amount of the recently fixed carbon (C) and of the absorbed N was determined. (13)C allocated to belowground organs such as roots and mycorrhizal hyphae accounted for an average of 10%, with 4.3% allocated to mycorrhizal hyphae within the first 24h after the pulse labeling. Mycorrhizae absorbed labeled inorganic nitrogen, of which almost 23% was retained in the fungal mycelium. The N uptake was linearly correlated with the (13)C fixed by the plants suggesting a positive correlation between a plant photosynthetic rate and the hyphal absorption capacity. PMID:25841208

  18. The allocation of ecosystem net primary productivity in tropical forests

    PubMed Central

    Malhi, Yadvinder; Doughty, Christopher; Galbraith, David

    2011-01-01

    The allocation of the net primary productivity (NPP) of an ecosystem between canopy, woody tissue and fine roots is an important descriptor of the functioning of that ecosystem, and an important feature to correctly represent in terrestrial ecosystem models. Here, we collate and analyse a global dataset of NPP allocation in tropical forests, and compare this with the representation of NPP allocation in 13 terrestrial ecosystem models. On average, the data suggest an equal partitioning of allocation between all three main components (mean 34 ± 6% canopy, 39 ± 10% wood, 27 ± 11% fine roots), but there is substantial site-to-site variation in allocation to woody tissue versus allocation to fine roots. Allocation to canopy (leaves, flowers and fruit) shows much less variance. The mean allocation of the ecosystem models is close to the mean of the data, but the spread is much greater, with several models reporting allocation partitioning outside of the spread of the data. Where all main components of NPP cannot be measured, litterfall is a good predictor of overall NPP (r2 = 0.83 for linear fit forced through origin), stem growth is a moderate predictor and fine root production a poor predictor. Across sites the major component of variation of allocation is a shifting allocation between wood and fine roots, with allocation to the canopy being a relatively invariant component of total NPP. This suggests the dominant allocation trade-off is a ‘fine root versus wood’ trade-off, as opposed to the expected ‘root–shoot’ trade-off; such a trade-off has recently been posited on theoretical grounds for old-growth forest stands. We conclude by discussing the systematic biases in estimates of allocation introduced by missing NPP components, including herbivory, large leaf litter and root exudates production. These biases have a moderate effect on overall carbon allocation estimates, but are smaller than the observed range in allocation values across sites. PMID

  19. Stochastic Particle Real Time Analyzer (SPARTA) Validation and Verification Suite

    SciTech Connect

    Gallis, Michael A.; Koehler, Timothy P.; Plimpton, Steven J.

    2014-10-01

    This report presents the test cases used to verify, validate and demonstrate the features and capabilities of the first release of the 3D Direct Simulation Monte Carlo (DSMC) code SPARTA (Stochastic Real Time Particle Analyzer). The test cases included in this report exercise the most critical capabilities of the code like the accurate representation of physical phenomena (molecular advection and collisions, energy conservation, etc.) and implementation of numerical methods (grid adaptation, load balancing, etc.). Several test cases of simple flow examples are shown to demonstrate that the code can reproduce phenomena predicted by analytical solutions and theory. A number of additional test cases are presented to illustrate the ability of SPARTA to model flow around complicated shapes. In these cases, the results are compared to other well-established codes or theoretical predictions. This compilation of test cases is not exhaustive, and it is anticipated that more cases will be added in the future.

  20. A Simulated Annealing Methodology to Multiproduct Capacitated Facility Location with Stochastic Demand

    PubMed Central

    Xiang, Hui; Ye, Yong; Ni, Linglin

    2015-01-01

    A stochastic multiproduct capacitated facility location problem involving a single supplier and multiple customers is investigated. Due to the stochastic demands, a reasonable amount of safety stock must be kept in the facilities to achieve suitable service levels, which results in increased inventory cost. Based on the assumption of normal distributed for all the stochastic demands, a nonlinear mixed-integer programming model is proposed, whose objective is to minimize the total cost, including transportation cost, inventory cost, operation cost, and setup cost. A combined simulated annealing (CSA) algorithm is presented to solve the model, in which the outer layer subalgorithm optimizes the facility location decision and the inner layer subalgorithm optimizes the demand allocation based on the determined facility location decision. The results obtained with this approach shown that the CSA is a robust and practical approach for solving a multiple product problem, which generates the suboptimal facility location decision and inventory policies. Meanwhile, we also found that the transportation cost and the demand deviation have the strongest influence on the optimal decision compared to the others. PMID:25834839

  1. Stochastic learning via optimizing the variational inequalities.

    PubMed

    Tao, Qing; Gao, Qian-Kun; Chu, De-Jun; Wu, Gao-Wei

    2014-10-01

    A wide variety of learning problems can be posed in the framework of convex optimization. Many efficient algorithms have been developed based on solving the induced optimization problems. However, there exists a gap between the theoretically unbeatable convergence rate and the practically efficient learning speed. In this paper, we use the variational inequality (VI) convergence to describe the learning speed. To this end, we avoid the hard concept of regret in online learning and directly discuss the stochastic learning algorithms. We first cast the regularized learning problem as a VI. Then, we present a stochastic version of alternating direction method of multipliers (ADMMs) to solve the induced VI. We define a new VI-criterion to measure the convergence of stochastic algorithms. While the rate of convergence for any iterative algorithms to solve nonsmooth convex optimization problems cannot be better than O(1/√t), the proposed stochastic ADMM (SADMM) is proved to have an O(1/t) VI-convergence rate for the l1-regularized hinge loss problems without strong convexity and smoothness. The derived VI-convergence results also support the viewpoint that the standard online analysis is too loose to analyze the stochastic setting properly. The experiments demonstrate that SADMM has almost the same performance as the state-of-the-art stochastic learning algorithms but its O(1/t) VI-convergence rate is capable of tightly characterizing the real learning speed.

  2. Stochastic resonance during a polymer translocation process

    NASA Astrophysics Data System (ADS)

    Mondal, Debasish; Muthukumar, M.

    2016-04-01

    We have studied the occurrence of stochastic resonance when a flexible polymer chain undergoes a single-file translocation through a nano-pore separating two spherical cavities, under a time-periodic external driving force. The translocation of the chain is controlled by a free energy barrier determined by chain length, pore length, pore-polymer interaction, and confinement inside the donor and receiver cavities. The external driving force is characterized by a frequency and amplitude. By combining the Fokker-Planck formalism for polymer translocation and a two-state model for stochastic resonance, we have derived analytical formulas for criteria for emergence of stochastic resonance during polymer translocation. We show that no stochastic resonance is possible if the free energy barrier for polymer translocation is purely entropic in nature. The polymer chain exhibits stochastic resonance only in the presence of an energy threshold in terms of polymer-pore interactions. Once stochastic resonance is feasible, the chain entropy controls the optimal synchronization conditions significantly.

  3. Automated Flight Routing Using Stochastic Dynamic Programming

    NASA Technical Reports Server (NTRS)

    Ng, Hok K.; Morando, Alex; Grabbe, Shon

    2010-01-01

    Airspace capacity reduction due to convective weather impedes air traffic flows and causes traffic congestion. This study presents an algorithm that reroutes flights in the presence of winds, enroute convective weather, and congested airspace based on stochastic dynamic programming. A stochastic disturbance model incorporates into the reroute design process the capacity uncertainty. A trajectory-based airspace demand model is employed for calculating current and future airspace demand. The optimal routes minimize the total expected traveling time, weather incursion, and induced congestion costs. They are compared to weather-avoidance routes calculated using deterministic dynamic programming. The stochastic reroutes have smaller deviation probability than the deterministic counterpart when both reroutes have similar total flight distance. The stochastic rerouting algorithm takes into account all convective weather fields with all severity levels while the deterministic algorithm only accounts for convective weather systems exceeding a specified level of severity. When the stochastic reroutes are compared to the actual flight routes, they have similar total flight time, and both have about 1% of travel time crossing congested enroute sectors on average. The actual flight routes induce slightly less traffic congestion than the stochastic reroutes but intercept more severe convective weather.

  4. Criteria for fairly allocating scarce health-care resources to genetic tests: which matter most?

    PubMed

    Rogowski, Wolf H; Grosse, Scott D; Schmidtke, Jörg; Marckmann, Georg

    2014-01-01

    The use of genetic tests is expanding rapidly. Given limited health-care budgets throughout Europe and few national coverage decisions specifically for genetic tests, decisions about allocating scarce resources to genetic tests are frequently ad hoc and left to lower-level decision makers. This study assesses substantive ethical and economic criteria to prioritize genetic services in a reasonable and fair manner. Principles for allocating health-care resources can be classified into four categories: need-based allocation; maximizing total benefits; treating people equally; and promoting and rewarding social usefulness. In the face of scarcity, the degree of an individual's need for medical intervention is an important criterion. Also, different economic concepts of efficiency are of relevance in the theory and practice of prioritizing genetic tests. Equity concerns are most likely to be relevant in terms of avoiding undesirable inequities, which may also set boundaries to the use of efficiency as a prioritization criterion. The aim of promoting and rewarding social usefulness is unlikely to be relevant to the question of what priority a genetic test should have in clinical practice. Further work is needed to select an appropriate set of criteria; operationalize them; and assign weights before some kind of standardized priority information can be added to information sources for genetic services. Besides the substantive criteria, formal considerations like those pointed out in the framework of accountability for reasonableness need to be considered in decision making. PMID:23921536

  5. 7 CFR 3430.311 - Allocation of research funds.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Allocation of research funds. 3430.311 Section 3430... ADMINISTRATIVE PROVISIONS Agriculture and Food Research Initiative § 3430.311 Allocation of research funds. (a) Fundamental research. Of the amount allocated by the Director for research, not less than 60 percent shall...

  6. 7 CFR 3430.311 - Allocation of research funds.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Allocation of research funds. 3430.311 Section 3430... ADMINISTRATIVE PROVISIONS Agriculture and Food Research Initiative § 3430.311 Allocation of research funds. (a) Fundamental research. Of the amount allocated by the Director for research, not less than 60 percent shall...

  7. Reward Allocation and Academic versus Social Orientation toward School.

    ERIC Educational Resources Information Center

    Peterson, Candida C.; Peterson, James L.

    1978-01-01

    Correlates 138 elementary school children's views about the purposes of school to their styles of reward allocation: academically motivated students allocated rewards equally to two hypothetical performers who had unequally helped a teacher perform a manual chore, while socially motivated children allocated rewards in an equity (performance-based)…

  8. 40 CFR 97.142 - CAIR NOX allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false CAIR NOX allowance allocations. 97.142... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR NOX Allowance Allocations § 97.142 CAIR NOX allowance allocations. (a)(1) The baseline heat input (in mmBtu) used...

  9. 40 CFR 96.42 - NOX allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  10. 40 CFR 97.42 - NOX allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  11. 40 CFR 96.142 - CAIR NOX allowance allocations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false CAIR NOX allowance allocations. 96.142... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Allowance Allocations § 96.142 CAIR NOX allowance allocations. (a)(1) The baseline heat...

  12. 14 CFR 93.215 - Initial allocation of slots.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Carrier IFR Operations at High Density Traffic Airports § 93.215 Initial allocation of slots. (a) Each air... of the air carrier and commuter operator scheduling committees, shall be allocated those slots... records of the scheduling committees, shall be allocated in conformity with those records. The...

  13. 14 CFR 93.215 - Initial allocation of slots.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Allocation of Commuter and Air Carrier IFR Operations at High Density Traffic Airports § 93.215 Initial allocation of slots. (a) Each air... of the air carrier and commuter operator scheduling committees, shall be allocated those...

  14. 14 CFR 93.215 - Initial allocation of slots.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES Allocation of Commuter and Air Carrier IFR Operations at High Density Traffic Airports § 93.215 Initial allocation of slots. (a) Each air... of the air carrier and commuter operator scheduling committees, shall be allocated those...

  15. 7 CFR 761.205 - Computing the formula allocation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 7 2012-01-01 2012-01-01 false Computing the formula allocation. 761.205 Section 761... Farm Loan Programs Funds to State Offices § 761.205 Computing the formula allocation. (a) The formula... funds for a loan program that the National Office allocates to a State Office. formula...

  16. 7 CFR 761.205 - Computing the formula allocation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 7 2013-01-01 2013-01-01 false Computing the formula allocation. 761.205 Section 761... Farm Loan Programs Funds to State Offices § 761.205 Computing the formula allocation. (a) The formula... funds for a loan program that the National Office allocates to a State Office. formula...

  17. 47 CFR 76.924 - Allocation to service cost categories.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... equipment basket based on direct analysis of the origin of the costs. (ii) Where allocation based on direct analysis is not possible, common costs for which no allocator has been specified by the Commission shall... be found, common costs shall be allocated to each service cost category based on the ratio of...

  18. 5 CFR 319.202 - Allocation of positions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 1 2014-01-01 2014-01-01 false Allocation of positions. 319.202 Section 319.202 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS EMPLOYMENT IN SENIOR-LEVEL AND SCIENTIFIC AND PROFESSIONAL POSITIONS Position Allocations and Establishment § 319.202 Allocation of positions. SL and...

  19. Motivation and Competence as Determinants of Young Children's Reward Allocation

    ERIC Educational Resources Information Center

    Nelson, Sharon A.; Dweck, Carol S.

    1977-01-01

    This study examined the effects of allocation instructions and self-interest on preschool children's use of the rule of equity in situations involving reward allocation. Results showed that when the demand for equity was explicit and self-interest was removed, all children used equity in allocating rewards. (Author/JMB)

  20. 10 CFR 490.703 - Biodiesel fuel use credit allocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Biodiesel fuel use credit allocation. 490.703 Section 490.703 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Biodiesel Fuel Use Credit § 490.703 Biodiesel fuel use credit allocation. (a) DOE shall allocate to a fleet...

  1. Reward Allocation among Chinese High School Students in Hong Kong.

    ERIC Educational Resources Information Center

    Chiu, Chi-Yue

    1989-01-01

    Examined effects of personality and performance on reward allocation. Subjects were 89 Hong Kong senior high school students. Results showed that the subjects took into consideration the recipient's personality when they allocated reward to a relatively low performer. Personality was not a factor in allocation of reward to a high performer. (GG)

  2. 47 CFR 32.22 - Comprehensive interperiod tax allocation.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false Comprehensive interperiod tax allocation. 32.22... interperiod tax allocation. (a) Companies shall apply interperiod tax allocation (tax normalization) to all book/tax temporary differences which would be considered material for published financial...

  3. 47 CFR 32.22 - Comprehensive interperiod tax allocation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Comprehensive interperiod tax allocation. 32.22... interperiod tax allocation. (a) Companies shall apply interperiod tax allocation (tax normalization) to all book/tax temporary differences which would be considered material for published financial...

  4. 47 CFR 32.22 - Comprehensive interperiod tax allocation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false Comprehensive interperiod tax allocation. 32.22... interperiod tax allocation. (a) Companies shall apply interperiod tax allocation (tax normalization) to all book/tax temporary differences which would be considered material for published financial...

  5. 47 CFR 32.22 - Comprehensive interperiod tax allocation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false Comprehensive interperiod tax allocation. 32.22... interperiod tax allocation. (a) Companies shall apply interperiod tax allocation (tax normalization) to all book/tax temporary differences which would be considered material for published financial...

  6. 40 CFR 97.142 - CAIR NOX allowance allocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CAIR NOX allowance allocations. 97.142... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS CAIR NOX Allowance Allocations § 97.142 CAIR NOX allowance allocations. (a)(1) The baseline heat input (in mmBtu) used...

  7. 40 CFR 96.42 - NOX allowance allocations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  8. 40 CFR 96.42 - NOX allowance allocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  9. 40 CFR 97.42 - NOX allowance allocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  10. 40 CFR 97.42 - NOX allowance allocations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  11. 40 CFR 96.42 - NOX allowance allocations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  12. 40 CFR 96.42 - NOX allowance allocations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false NOX allowance allocations. 96.42... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO 2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS NOX Allowance Allocations § 96.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used...

  13. 40 CFR 96.142 - CAIR NOX allowance allocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CAIR NOX allowance allocations. 96.142... (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Allowance Allocations § 96.142 CAIR NOX allowance allocations. (a)(1) The baseline heat...

  14. 40 CFR 97.42 - NOX allowance allocations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false NOX allowance allocations. 97.42... (CONTINUED) FEDERAL NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS NOX Allowance Allocations § 97.42 NOX allowance allocations. (a)(1) The heat input (in mmBtu) used for calculating...

  15. 20 CFR 632.252 - Allocation of funds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 20 Employees' Benefits 3 2010-04-01 2010-04-01 false Allocation of funds. 632.252 Section 632.252... EMPLOYMENT AND TRAINING PROGRAMS Summer Youth Employment and Training Programs § 632.252 Allocation of funds... available in the CETA, IV-C Fiscal Year 1983 program. (b) Allocations shall be made to eligible...

  16. 14 CFR 1260.61 - Allocation of risk/liability.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Allocation of risk/liability. 1260.61 Section 1260.61 Aeronautics and Space NATIONAL AERONAUTICS AND SPACE ADMINISTRATION GRANTS AND COOPERATIVE AGREEMENTS General Special Conditions § 1260.61 Allocation of risk/liability. Allocation of...

  17. 26 CFR 1.652(b)-3 - Allocation of deductions.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 8 2010-04-01 2010-04-01 false Allocation of deductions. 1.652(b)-3 Section 1... (CONTINUED) INCOME TAXES Trusts Which Distribute Current Income Only § 1.652(b)-3 Allocation of deductions... not included in distributable net income does not affect allocation under this paragraph. For...

  18. 48 CFR 408.705-3 - Allocation process.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Allocation process. 408... Employing People Who Are Blind or Severely Disabled 408.705-3 Allocation process. (a) The chief of a contracting office may apply to a central nonprofit agency for a production allocation of specific supplies...

  19. 17 CFR 256.01-11 - Methods of allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Methods of allocation. 256.01... HOLDING COMPANY ACT OF 1935 General Instructions § 256.01-11 Methods of allocation. Indirect costs and... applicable and currently effective methods of allocation filed with the Commission. Both direct and...

  20. 26 CFR 1.456-3 - Method of allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Method of allocation. 1.456-3 Section 1.456-3...) INCOME TAXES Taxable Year for Which Items of Gross Income Included § 1.456-3 Method of allocation. (a... method of aggregation and allocation is consistently followed....

  1. 45 CFR 152.33 - Initial allocation of funds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 1 2010-10-01 2010-10-01 false Initial allocation of funds. 152.33 Section 152.33...-EXISTING CONDITION INSURANCE PLAN PROGRAM Funding § 152.33 Initial allocation of funds. HHS will establish... State using a methodology consistent with that used to established allocations under the...

  2. 26 CFR 1.455-3 - Method of allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 6 2010-04-01 2010-04-01 false Method of allocation. 1.455-3 Section 1.455-3...) INCOME TAXES Taxable Year for Which Items of Gross Income Included § 1.455-3 Method of allocation. (a... reasonable manner, provided the method of aggregation and allocation is consistently followed....

  3. 10 CFR 470.15 - Allocation of funds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Allocation of funds. 470.15 Section 470.15 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION APPROPRIATE TECHNOLOGY SMALL GRANTS PROGRAM § 470.15 Allocation of funds. (a) DOE shall annually allocate fiscal year funds available for support among the 10...

  4. 30 CFR 1206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Allocation of washed coal. 1206.260 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  5. 30 CFR 1206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Allocation of washed coal. 1206.260 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  6. 30 CFR 1206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Allocation of washed coal. 1206.459 Section... RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  7. 30 CFR 1206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Allocation of washed coal. 1206.260 Section... RESOURCES REVENUE PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  8. 30 CFR 1206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Allocation of washed coal. 1206.459 Section... RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  9. 30 CFR 1206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Allocation of washed coal. 1206.459 Section... INTERIOR Natural Resources Revenue PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it...

  10. 30 CFR 1206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false Allocation of washed coal. 1206.260 Section... INTERIOR Natural Resources Revenue PRODUCT VALUATION Federal Coal § 1206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it...

  11. 30 CFR 206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Allocation of washed coal. 206.459 Section 206... MANAGEMENT PRODUCT VALUATION Indian Coal § 206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b) When the...

  12. 30 CFR 1206.459 - Allocation of washed coal.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false Allocation of washed coal. 1206.459 Section... RESOURCES REVENUE PRODUCT VALUATION Indian Coal § 1206.459 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b)...

  13. 30 CFR 206.260 - Allocation of washed coal.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Allocation of washed coal. 206.260 Section 206... MANAGEMENT PRODUCT VALUATION Federal Coal § 206.260 Allocation of washed coal. (a) When coal is subjected to washing, the washed coal must be allocated to the leases from which it was extracted. (b) When the...

  14. 77 FR 54482 - Allocation of Costs Under the Simplified Methods

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-05

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BG07 Allocation of Costs Under the Simplified Methods... document contains proposed regulations on allocating costs to certain property produced by the taxpayer or... resellers of property that are required to capitalize certain costs to the property and that allocate...

  15. 7 CFR 761.205 - Computing the formula allocation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Computing the formula allocation. 761.205 Section 761.205 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY... Funds to State Offices § 761.205 Computing the formula allocation. (a) The formula allocation for FO...

  16. 18 CFR 367.28 - Methods of allocation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Methods of allocation... Instructions § 367.28 Methods of allocation. Indirect costs and compensation for use of capital must be allocated to projects in accordance with the service company's applicable and currently effective methods...

  17. 12 CFR 211.43 - Allocated transfer risk reserve.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 2 2010-01-01 2010-01-01 false Allocated transfer risk reserve. 211.43 Section... risk reserve. (a) Establishment of Allocated Transfer Risk Reserve. A banking institution shall establish an allocated transfer risk reserve (ATRR) for specified international assets when required by...

  18. 10 CFR 490.703 - Biodiesel fuel use credit allocation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Biodiesel fuel use credit allocation. 490.703 Section 490.703 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Biodiesel Fuel Use Credit § 490.703 Biodiesel fuel use credit allocation. (a) DOE shall allocate to a fleet...

  19. 10 CFR 490.703 - Biodiesel fuel use credit allocation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Biodiesel fuel use credit allocation. 490.703 Section 490.703 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ALTERNATIVE FUEL TRANSPORTATION PROGRAM Biodiesel Fuel Use Credit § 490.703 Biodiesel fuel use credit allocation. (a) DOE shall allocate to a fleet...

  20. 26 CFR 1.642(h)-4 - Allocation.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 8 2011-04-01 2011-04-01 false Allocation. 1.642(h)-4 Section 1.642(h)-4...) INCOME TAXES (CONTINUED) Estates, Trusts, and Beneficiaries § 1.642(h)-4 Allocation. The carryovers and excess deductions to which section 642(h) applies are allocated among the beneficiaries succeeding to...