WorldWideScience

Sample records for continuously distributed delays

  1. Novel delay-distribution-dependent stability analysis for continuous-time recurrent neural networks with stochastic delay

    Wang Shen-Quan; Feng Jian; Zhao Qing

    2012-01-01

    In this paper, the problem of delay-distribution-dependent stability is investigated for continuous-time recurrent neural networks (CRNNs) with stochastic delay. Different from the common assumptions on time delays, it is assumed that the probability distribution of the delay taking values in some intervals is known a priori. By making full use of the information concerning the probability distribution of the delay and by using a tighter bounding technique (the reciprocally convex combination method), less conservative asymptotic mean-square stable sufficient conditions are derived in terms of linear matrix inequalities (LMIs). Two numerical examples show that our results are better than the existing ones. (general)

  2. Global asymptotic stability of Cohen-Grossberg neural network with continuously distributed delays

    Wan Li; Sun Jianhua

    2005-01-01

    The convergence dynamical behaviors of Cohen-Grossberg neural network with continuously distributed delays are discussed. By using Brouwer's fixed point theorem, matrix theory and analysis techniques such as Gronwall inequality, some new sufficient conditions guaranteeing the existence, uniqueness of an equilibrium point and its global asymptotic stability are obtained. An example is given to illustrate the theoretical results

  3. Global exponential stability of cellular neural networks with continuously distributed delays and impulses

    Wang Yixuan; Xiong Wanmin; Zhou Qiyuan; Xiao Bing; Yu Yuehua

    2006-01-01

    In this Letter cellular neural networks with continuously distributed delays and impulses are considered. Sufficient conditions for the existence and global exponential stability of a unique equilibrium point are established by using the fixed point theorem and differential inequality techniques. The results of this Letter are new and they complement previously known results

  4. Existence and global exponential stability of periodic solution to BAM neural networks with periodic coefficients and continuously distributed delays

    Zhou Tiejun; Chen Anping; Zhou Yuyuan

    2005-01-01

    By using the continuation theorem of coincidence degree theory and Liapunov function, we obtain some sufficient criteria to ensure the existence and global exponential stability of periodic solution to the bidirectional associative memory (BAM) neural networks with periodic coefficients and continuously distributed delays. These results improve and generalize the works of papers [J. Cao, L. Wang, Phys. Rev. E 61 (2000) 1825] and [Z. Liu, A. Chen, J. Cao, L. Huang, IEEE Trans. Circuits Systems I 50 (2003) 1162]. An example is given to illustrate that the criteria are feasible

  5. Existence and global exponential stability of periodic solution to BAM neural networks with periodic coefficients and continuously distributed delays

    Zhou, distributed delays [rapid communication] T.; Chen, A.; Zhou, Y.

    2005-08-01

    By using the continuation theorem of coincidence degree theory and Liapunov function, we obtain some sufficient criteria to ensure the existence and global exponential stability of periodic solution to the bidirectional associative memory (BAM) neural networks with periodic coefficients and continuously distributed delays. These results improve and generalize the works of papers [J. Cao, L. Wang, Phys. Rev. E 61 (2000) 1825] and [Z. Liu, A. Chen, J. Cao, L. Huang, IEEE Trans. Circuits Systems I 50 (2003) 1162]. An example is given to illustrate that the criteria are feasible.

  6. A continuous time Cournot duopoly with delays

    Gori, Luca; Guerrini, Luca; Sodini, Mauro

    2015-01-01

    This paper extends the classical repeated duopoly model with quantity-setting firms of Bischi et al. (1998) by assuming that production of goods is subject to some gestation lags but exchanges take place continuously in the market. The model is expressed in the form of differential equations with discrete delays. By using some recent mathematical techniques and numerical experiments, results show some dynamic phenomena that cannot be observed when delays are absent. In addition, depending on the extent of time delays and inertia, synchronisation failure can arise even in the event of homogeneous firms.

  7. Time-delay analyzer with continuous discretization

    Bayatyan, G.L.; Darbinyan, K.T.; Mkrtchyan, K.K.; Stepanyan, S.S.

    1988-01-01

    A time-delay analyzer is described which when triggered by a start pulse of adjustable duration performs continuous discretization of the analyzed signal within nearly 22 ns time intervals, the recording in a memory unit with following slow read-out of the information to the computer and its processing. The time-delay analyzer consists of four CAMAC-VECTOR systems of unit width. With its help one can separate comparatively short, small-amplitude rare signals against the background of quasistationary noise processes. 4 refs.; 3 figs

  8. Distributed synthesis in continuous time

    Hermanns, Holger; Krčál, Jan; Vester, Steen

    2016-01-01

    We introduce a formalism modelling communication of distributed agents strictly in continuous-time. Within this framework, we study the problem of synthesising local strategies for individual agents such that a specified set of goal states is reached, or reached with at least a given probability....... The flow of time is modelled explicitly based on continuous-time randomness, with two natural implications: First, the non-determinism stemming from interleaving disappears. Second, when we restrict to a subclass of non-urgent models, the quantitative value problem for two players can be solved in EXPTIME....... Indeed, the explicit continuous time enables players to communicate their states by delaying synchronisation (which is unrestricted for non-urgent models). In general, the problems are undecidable already for two players in the quantitative case and three players in the qualitative case. The qualitative...

  9. A Discrete Model for HIV Infection with Distributed Delay

    Brahim EL Boukari

    2014-01-01

    Full Text Available We give a consistent discretization of a continuous model of HIV infection, with distributed time delays to express the lag between the times when the virus enters a cell and when the cell becomes infected. The global stability of the steady states of the model is determined and numerical simulations are presented to illustrate our theoretical results.

  10. Distributed Optimal Consensus Control for Multiagent Systems With Input Delay.

    Zhang, Huaipin; Yue, Dong; Zhao, Wei; Hu, Songlin; Dou, Chunxia; Huaipin Zhang; Dong Yue; Wei Zhao; Songlin Hu; Chunxia Dou; Hu, Songlin; Zhang, Huaipin; Dou, Chunxia; Yue, Dong; Zhao, Wei

    2018-06-01

    This paper addresses the problem of distributed optimal consensus control for a continuous-time heterogeneous linear multiagent system subject to time varying input delays. First, by discretization and model transformation, the continuous-time input-delayed system is converted into a discrete-time delay-free system. Two delicate performance index functions are defined for these two systems. It is shown that the performance index functions are equivalent and the optimal consensus control problem of the input-delayed system can be cast into that of the delay-free system. Second, by virtue of the Hamilton-Jacobi-Bellman (HJB) equations, an optimal control policy for each agent is designed based on the delay-free system and a novel value iteration algorithm is proposed to learn the solutions to the HJB equations online. The proposed adaptive dynamic programming algorithm is implemented on the basis of a critic-action neural network (NN) structure. Third, it is proved that local consensus errors of the two systems and weight estimation errors of the critic-action NNs are uniformly ultimately bounded while the approximated control policies converge to their target values. Finally, two simulation examples are presented to illustrate the effectiveness of the developed method.

  11. Derivation and computation of discrete-delay and continuous-delay SDEs in mathematical biology.

    Allen, Edward J

    2014-06-01

    Stochastic versions of several discrete-delay and continuous-delay differential equations, useful in mathematical biology, are derived from basic principles carefully taking into account the demographic, environmental, or physiological randomness in the dynamic processes. In particular, stochastic delay differential equation (SDDE) models are derived and studied for Nicholson's blowflies equation, Hutchinson's equation, an SIS epidemic model with delay, bacteria/phage dynamics, and glucose/insulin levels. Computational methods for approximating the SDDE models are described. Comparisons between computational solutions of the SDDEs and independently formulated Monte Carlo calculations support the accuracy of the derivations and of the computational methods.

  12. Fuzzy extractors for continuous distributions

    Buhan, I.R.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.

    2006-01-01

    We show that there is a direct relation between the maximum length of the keys extracted from biometric data and the error rates of the biometric system. The length of the bio-key depends on the amount of distinguishing information that can be extracted from the source data. This information can be used a-priori to evaluate the potential of the biometric data in the context of a specific cryptographic application. We model the biometric data more naturally as a continuous distribution and we ...

  13. Adaptive modification of the delayed feedback control algorithm with a continuously varying time delay

    Pyragas, V.; Pyragas, K.

    2011-01-01

    We propose a simple adaptive delayed feedback control algorithm for stabilization of unstable periodic orbits with unknown periods. The state dependent time delay is varied continuously towards the period of controlled orbit according to a gradient-descent method realized through three simple ordinary differential equations. We demonstrate the efficiency of the algorithm with the Roessler and Mackey-Glass chaotic systems. The stability of the controlled orbits is proven by computation of the Lyapunov exponents of linearized equations. -- Highlights: → A simple adaptive modification of the delayed feedback control algorithm is proposed. → It enables the control of unstable periodic orbits with unknown periods. → The delay time is varied continuously according to a gradient descend method. → The algorithm is embodied by three simple ordinary differential equations. → The validity of the algorithm is proven by computation of the Lyapunov exponents.

  14. Continuous sampling from distributed streams

    Graham, Cormode; Muthukrishnan, S.; Yi, Ke

    2012-01-01

    A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple distribu......A fundamental problem in data management is to draw and maintain a sample of a large data set, for approximate query answering, selectivity estimation, and query planning. With large, streaming data sets, this problem becomes particularly difficult when the data is shared across multiple...... distributed sites. The main challenge is to ensure that a sample is drawn uniformly across the union of the data while minimizing the communication needed to run the protocol on the evolving data. At the same time, it is also necessary to make the protocol lightweight, by keeping the space and time costs low...... for each participant. In this article, we present communication-efficient protocols for continuously maintaining a sample (both with and without replacement) from k distributed streams. These apply to the case when we want a sample from the full streams, and to the sliding window cases of only the W most...

  15. Dynamical Models For Prices With Distributed Delays

    Mircea Gabriela

    2015-06-01

    Full Text Available In the present paper we study some models for the price dynamics of a single commodity market. The quantities of supplied and demanded are regarded as a function of time. Nonlinearities in both supply and demand functions are considered. The inventory and the level of inventory are taken into consideration. Due to the fact that the consumer behavior affects commodity demand, and the behavior is influenced not only by the instantaneous price, but also by the weighted past prices, the distributed time delay is introduced. The following kernels are taken into consideration: demand price weak kernel and demand price Dirac kernel. Only one positive equilibrium point is found and its stability analysis is presented. When the demand price kernel is weak, under some conditions of the parameters, the equilibrium point is locally asymptotically stable. When the demand price kernel is Dirac, the existence of the local oscillations is investigated. A change in local stability of the equilibrium point, from stable to unstable, implies a Hopf bifurcation. A family of periodic orbits bifurcates from the positive equilibrium point when the time delay passes through a critical value. The last part contains some numerical simulations to illustrate the effectiveness of our results and conclusions.

  16. Continuous atmosperic pollutant distribution monitor

    Burger, L.W.

    1984-06-01

    The feasibility of an on-line continuous pollutant distribution monitor has been established. The device employs a small microprocessor to simulate atmospheric dispersion using the segmented Gaussian plume model, an anemometer-bivane to measure the wind conditions, and a control 'box' with which certain model parameters can be specified and changed without interrupting the execution of the computer program. The output of the device is in the form of contours of equal ground-level concentrations on a colour monitor, or a printer dump of the associated graphic screen. The device is only suitable for short range predictions due to the memory limitations of the microprocessor. Predictions are updated approximately once every minute. Various case studies were performed to investigate the behaviour of the model when subjected to controlled input data. A series of short-range experimental runs were conducted in which predicted SO 2 concentrations were compared with measured values. The performance of the model in the case studies was acceptable, and comparisons with the measured SO 2 concentration values proved the model to overpredict by about 30%, which is considered satisfactory. This study can be applied to radioactive effluents transport in the atmosphere

  17. Global robust stability of neural networks with multiple discrete delays and distributed delays

    Gao Ming; Cui Baotong

    2009-01-01

    The problem of global robust stability is investigated for a class of uncertain neural networks with both multiple discrete time-varying delays and distributed time-varying delays. The uncertainties are assumed to be of norm-bounded form and the activation functions are supposed to be bounded and globally Lipschitz continuous. Based on the Lyapunov stability theory and linear matrix inequality technique, some robust stability conditions guaranteeing the global robust convergence of the equilibrium point are derived. The proposed LMI-based criteria are computationally efficient as they can be easily checked by using recently developed algorithms in solving LMIs. Two examples are given to show the effectiveness of the proposed results.

  18. Spiking Activity of a LIF Neuron in Distributed Delay Framework

    Saket Kumar Choudhary

    2016-06-01

    Full Text Available Evolution of membrane potential and spiking activity for a single leaky integrate-and-fire (LIF neuron in distributed delay framework (DDF is investigated. DDF provides a mechanism to incorporate memory element in terms of delay (kernel function into a single neuron models. This investigation includes LIF neuron model with two different kinds of delay kernel functions, namely, gamma distributed delay kernel function and hypo-exponential distributed delay kernel function. Evolution of membrane potential for considered models is studied in terms of stationary state probability distribution (SPD. Stationary state probability distribution of membrane potential (SPDV for considered neuron models are found asymptotically similar which is Gaussian distributed. In order to investigate the effect of membrane potential delay, rate code scheme for neuronal information processing is applied. Firing rate and Fano-factor for considered neuron models are calculated and standard LIF model is used for comparative study. It is noticed that distributed delay increases the spiking activity of a neuron. Increase in spiking activity of neuron in DDF is larger for hypo-exponential distributed delay function than gamma distributed delay function. Moreover, in case of hypo-exponential delay function, a LIF neuron generates spikes with Fano-factor less than 1.

  19. Periodic bidirectional associative memory neural networks with distributed delays

    Chen, Anping; Huang, Lihong; Liu, Zhigang; Cao, Jinde

    2006-05-01

    Some sufficient conditions are obtained for the existence and global exponential stability of a periodic solution to the general bidirectional associative memory (BAM) neural networks with distributed delays by using the continuation theorem of Mawhin's coincidence degree theory and the Lyapunov functional method and the Young's inequality technique. These results are helpful for designing a globally exponentially stable and periodic oscillatory BAM neural network, and the conditions can be easily verified and be applied in practice. An example is also given to illustrate our results.

  20. Existence and stability of periodic solution in impulsive Hopfield neural networks with finite distributed delays

    Yang Xiaofan; Liao Xiaofeng; Evans, David J.; Tang Yuanyan

    2005-01-01

    In this Letter, we introduce a class of Hopfield neural networks with periodic impulses and finite distributed delays. We then derive a sufficient condition for the existence and global exponential stability of a unique periodic solution of the networks, which assumes neither the differentiability nor the monotonicity of the activation functions. Our condition extends and generalizes a known condition for the global exponential periodicity of continuous Hopfield neural networks with finite distributed delays

  1. Distributed optimisation problem with communication delay and external disturbance

    Tran, Ngoc-Tu; Xiao, Jiang-Wen; Wang, Yan-Wu; Yang, Wu

    2017-12-01

    This paper investigates the distributed optimisation problem for the multi-agent systems (MASs) with the simultaneous presence of external disturbance and the communication delay. To solve this problem, a two-step design scheme is introduced. In the first step, based on the internal model principle, the internal model term is constructed to compensate the disturbance asymptotically. In the second step, a distributed optimisation algorithm is designed to solve the distributed optimisation problem based on the MASs with the simultaneous presence of disturbance and communication delay. Moreover, in the proposed algorithm, each agent interacts with its neighbours through the connected topology and the delay occurs during the information exchange. By utilising Lyapunov-Krasovskii functional, the delay-dependent conditions are derived for both slowly and fast time-varying delay, respectively, to ensure the convergence of the algorithm to the optimal solution of the optimisation problem. Several numerical simulation examples are provided to illustrate the effectiveness of the theoretical results.

  2. A distributed delay approach for modeling delayed outcomes in pharmacokinetics and pharmacodynamics studies.

    Hu, Shuhua; Dunlavey, Michael; Guzy, Serge; Teuscher, Nathan

    2018-04-01

    A distributed delay approach was proposed in this paper to model delayed outcomes in pharmacokinetics and pharmacodynamics studies. This approach was shown to be general enough to incorporate a wide array of pharmacokinetic and pharmacodynamic models as special cases including transit compartment models, effect compartment models, typical absorption models (either zero-order or first-order absorption), and a number of atypical (or irregular) absorption models (e.g., parallel first-order, mixed first-order and zero-order, inverse Gaussian, and Weibull absorption models). Real-life examples were given to demonstrate how to implement distributed delays in Phoenix ® NLME™ 8.0, and to numerically show the advantages of the distributed delay approach over the traditional methods.

  3. Adaptive control of chaotic continuous-time systems with delay

    Tian, Yu-Chu; Gao, Furong

    1998-06-01

    A simple delay system governed by a first-order differential-delay equation may behave chaotically, but the conditions for the system to have such behaviors have not been well recognized. In this paper, a set of rules is postulated first for the conditions for the delay system to display chaos. A model-reference adaptive control scheme is then proposed to control the chaotic system state to converge to an arbitrarily given reference trajectory with certain and uncertain system parameters. Numerical examples are given to analyze the chaotic behaviors of the delay system and to demonstrate the effectiveness of the proposed adaptive control scheme.

  4. Delay-dependent exponential stability for neural networks with discrete and distributed time-varying delays

    Zhu Xunlin; Wang Youyi

    2009-01-01

    This Letter studies the exponential stability for a class of neural networks (NNs) with both discrete and distributed time-varying delays. Under weaker assumptions on the activation functions, by defining a more general type of Lyapunov functionals and developing a new convex combination technique, new less conservative and less complex stability criteria are established to guarantee the global exponential stability of the discussed NNs. The obtained conditions are dependent on both discrete and distributed delays, are expressed in terms of linear matrix inequalities (LMIs), and contain fewer decision variables. Numerical examples are given to illustrate the effectiveness and the less conservatism of the proposed conditions.

  5. Oscillation of second order neutral dynamic equations with distributed delay

    Qiaoshun Yang

    2016-06-01

    Full Text Available In this paper, we establish new oscillation criteria for second order neutral dynamic equations with distributed delay by employing the generalized Riccati transformation. The obtained theorems essentially improve the oscillation results in the literature. And two examples are provided to illustrate to the versatility of our main results.

  6. Stability Tests of Positive Fractional Continuous-time Linear Systems with Delays

    Tadeusz Kaczorek

    2013-06-01

    Full Text Available Necessary and sufficient conditions for the asymptotic stability of positive fractional continuous-time linear systems with many delays are established. It is shown that: 1 the asymptotic stability of the positive fractional system is independent of their delays, 2 the checking of the asymptotic stability of the positive fractional systems with delays can be reduced to checking of the asymptotic stability of positive standard linear systems without delays.

  7. Stability results for stochastic delayed recurrent neural networks with discrete and distributed delays

    Chen, Guiling; Li, Dingshi; Shi, Lin; van Gaans, Onno; Verduyn Lunel, Sjoerd

    2018-03-01

    We present new conditions for asymptotic stability and exponential stability of a class of stochastic recurrent neural networks with discrete and distributed time varying delays. Our approach is based on the method using fixed point theory, which do not resort to any Liapunov function or Liapunov functional. Our results neither require the boundedness, monotonicity and differentiability of the activation functions nor differentiability of the time varying delays. In particular, a class of neural networks without stochastic perturbations is also considered. Examples are given to illustrate our main results.

  8. Mean, covariance, and effective dimension of stochastic distributed delay dynamics

    René, Alexandre; Longtin, André

    2017-11-01

    Dynamical models are often required to incorporate both delays and noise. However, the inherently infinite-dimensional nature of delay equations makes formal solutions to stochastic delay differential equations (SDDEs) challenging. Here, we present an approach, similar in spirit to the analysis of functional differential equations, but based on finite-dimensional matrix operators. This results in a method for obtaining both transient and stationary solutions that is directly amenable to computation, and applicable to first order differential systems with either discrete or distributed delays. With fewer assumptions on the system's parameters than other current solution methods and no need to be near a bifurcation, we decompose the solution to a linear SDDE with arbitrary distributed delays into natural modes, in effect the eigenfunctions of the differential operator, and show that relatively few modes can suffice to approximate the probability density of solutions. Thus, we are led to conclude that noise makes these SDDEs effectively low dimensional, which opens the possibility of practical definitions of probability densities over their solution space.

  9. 12 CFR 563g.16 - Delayed or continuous offering and sale of securities.

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Delayed or continuous offering and sale of securities. 563g.16 Section 563g.16 Banks and Banking OFFICE OF THRIFT SUPERVISION, DEPARTMENT OF THE TREASURY SECURITIES OFFERINGS § 563g.16 Delayed or continuous offering and sale of securities. Any offer or...

  10. Neuronal model with distributed delay: analysis and simulation study for gamma distribution memory kernel.

    Karmeshu; Gupta, Varun; Kadambari, K V

    2011-06-01

    A single neuronal model incorporating distributed delay (memory)is proposed. The stochastic model has been formulated as a Stochastic Integro-Differential Equation (SIDE) which results in the underlying process being non-Markovian. A detailed analysis of the model when the distributed delay kernel has exponential form (weak delay) has been carried out. The selection of exponential kernel has enabled the transformation of the non-Markovian model to a Markovian model in an extended state space. For the study of First Passage Time (FPT) with exponential delay kernel, the model has been transformed to a system of coupled Stochastic Differential Equations (SDEs) in two-dimensional state space. Simulation studies of the SDEs provide insight into the effect of weak delay kernel on the Inter-Spike Interval(ISI) distribution. A measure based on Jensen-Shannon divergence is proposed which can be used to make a choice between two competing models viz. distributed delay model vis-á-vis LIF model. An interesting feature of the model is that the behavior of (CV(t))((ISI)) (Coefficient of Variation) of the ISI distribution with respect to memory kernel time constant parameter η reveals that neuron can switch from a bursting state to non-bursting state as the noise intensity parameter changes. The membrane potential exhibits decaying auto-correlation structure with or without damped oscillatory behavior depending on the choice of parameters. This behavior is in agreement with empirically observed pattern of spike count in a fixed time window. The power spectral density derived from the auto-correlation function is found to exhibit single and double peaks. The model is also examined for the case of strong delay with memory kernel having the form of Gamma distribution. In contrast to fast decay of damped oscillations of the ISI distribution for the model with weak delay kernel, the decay of damped oscillations is found to be slower for the model with strong delay kernel.

  11. Dynamical Analysis of SIR Epidemic Models with Distributed Delay

    Wencai Zhao

    2013-01-01

    Full Text Available SIR epidemic models with distributed delay are proposed. Firstly, the dynamical behaviors of the model without vaccination are studied. Using the Jacobian matrix, the stability of the equilibrium points of the system without vaccination is analyzed. The basic reproduction number R is got. In order to study the important role of vaccination to prevent diseases, the model with distributed delay under impulsive vaccination is formulated. And the sufficient conditions of globally asymptotic stability of “infection-free” periodic solution and the permanence of the model are obtained by using Floquet’s theorem, small-amplitude perturbation skills, and comparison theorem. Lastly, numerical simulation is presented to illustrate our main conclusions that vaccination has significant effects on the dynamical behaviors of the model. The results can provide effective tactic basis for the practical infectious disease prevention.

  12. Continuous particle spectra and their angular distributions

    Sastry, Ch.V.; Jain, R.K.; Rama Rao, J.; Ernst, J.; Machner, H.

    1996-01-01

    The angular distribution of continuous particle spectra in pre-equilibrium reactions is still an unsolved problem, particularly so at forward angles. In the present work, the angular distributions of alpha particles emitted in (α, α',x) reactions in the target elements gold and rhodium have been studied in detail. Alpha particle beams of energy 60 MeV from the Variable Energy Cyclotron of Calcutta were used in these experiments. The theoretical calculations were done using an extended exciton model of Kalbach incorporated into the Computer Code PRECO-D2. The formalism used in the exciton model was modified to include division of pre equilibrium cross section into multi-step direct (MSD) and multi-step compound (MSC) components. These MSD and MSC cross sections were used to calculate the angular distributions in terms of Legendre polynomials whose coefficients are given by simple phenomenological relations. Even with a reasonable set of parameters, the agreement between theory and experiment was far from satisfactory at forward angles. Similar conclusion was also drawn in the case of continuous particle spectra of deuterons in (d, d'x) reactions at 25 MeV in various targets. (author). 10 refs., 2 figs

  13. Design of Distributed Engine Control Systems with Uncertain Delay.

    Xiaofeng Liu

    Full Text Available Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS. Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method.

  14. Design of Distributed Engine Control Systems with Uncertain Delay.

    Liu, Xiaofeng; Li, Yanxi; Sun, Xu

    Future gas turbine engine control systems will be based on distributed architecture, in which, the sensors and actuators will be connected to the controllers via a communication network. The performance of the distributed engine control (DEC) is dependent on the network performance. This study introduces a distributed control system architecture based on a networked cascade control system (NCCS). Typical turboshaft engine-distributed controllers are designed based on the NCCS framework with a H∞ output feedback under network-induced time delays and uncertain disturbances. The sufficient conditions for robust stability are derived via the Lyapunov stability theory and linear matrix inequality approach. Both numerical and hardware-in-loop simulations illustrate the effectiveness of the presented method.

  15. System of delay difference equations with continuous time with lag function between two known functions

    Hajnalka Péics

    2016-08-01

    Full Text Available The asymptotic behavior of solutions of the system of difference equations with continuous time and lag function between two known real functions is studied. The cases when the lag function is between two linear delay functions, between two power delay functions and between two constant delay functions are observed and illustrated by examples. The asymptotic estimates of solutions of the considered system are obtained.

  16. Stationary distributions of stochastic processes described by a linear neutral delay differential equation

    Frank, T D

    2005-01-01

    Stationary distributions of processes are derived that involve a time delay and are defined by a linear stochastic neutral delay differential equation. The distributions are Gaussian distributions. The variances of the Gaussian distributions are either monotonically increasing or decreasing functions of the time delays. The variances become infinite when fixed points of corresponding deterministic processes become unstable. (letter to the editor)

  17. Topology Identification of General Dynamical Network with Distributed Time Delays

    Zhao-Yan, Wu; Xin-Chu, Fu

    2009-01-01

    General dynamical networks with distributed time delays are studied. The topology of the networks are viewed as unknown parameters, which need to be identified. Some auxiliary systems (also called the network estimators) are designed to achieve this goal. Both linear feedback control and adaptive strategy are applied in designing these network estimators. Based on linear matrix inequalities and the Lyapunov function method, the sufficient condition for the achievement of topology identification is obtained. This method can also better monitor the switching topology of dynamical networks. Illustrative examples are provided to show the effectiveness of this method. (general)

  18. About the distribution of delays in G.M counters

    Picard, E.; Rogozinski, A.

    1954-01-01

    We measure, with an oscillograph method the global time that pass between the time that a particle in a determined region of the studied counter and the answer of the amplifier associated to the counter. This delay is composed of the latency time T l and the T q delay, that result from the rise time finished of the impulse and whose value depends of the sensitivity threshold of the amplifier. The selection of (cosmic) particles generating discharge in the studied counter is obtained thanks to a telescope of two meters in coincidence whose opening is limited by a group of four counters in anti-coincidence with the first. The meter is arranged so that the median plan of the telescope crosses to a variable distance d of his axial thread. The measures have been done for different securities of the distance d and of the over-voltage V s applied to the counter. The results show that the statistical distribution of the delays is more spread especially when d is bigger and V s more reduced. The average values of the observed delays vary of 7.10 -8 s for d = 0 and V s es = 200 V, to 90.10 -8 s for d = 1,9 cm and V s = 50 V. The mobility of an free electron within the gaseous mixture filling the counter under a pressure of 10 cm.Hg was found equal: (2,1 ±0,2).10 4 cm 2 .s -1 .V -1 . (author) [fr

  19. Distributed Position-Based Consensus of Second-Order Multiagent Systems With Continuous/Intermittent Communication.

    Song, Qiang; Liu, Fang; Wen, Guanghui; Cao, Jinde; Yang, Xinsong

    2017-04-24

    This paper considers the position-based consensus in a network of agents with double-integrator dynamics and directed topology. Two types of distributed observer algorithms are proposed to solve the consensus problem by utilizing continuous and intermittent position measurements, respectively, where each observer does not interact with any other observers. For the case of continuous communication between network agents, some convergence conditions are derived for reaching consensus in the network with a single constant delay or multiple time-varying delays on the basis of the eigenvalue analysis and the descriptor method. When the network agents can only obtain intermittent position data from local neighbors at discrete time instants, the consensus in the network without time delay or with nonuniform delays is investigated by using the Wirtinger's inequality and the delayed-input approach. Numerical examples are given to illustrate the theoretical analysis.

  20. On the form of the forgetting function: the effects of arithmetic and logarithmic distributions of delays.

    Sargisson, Rebecca J; White, K Geoffrey

    2003-11-01

    Forgetting functions with 18 delay intervals were generated for delayed matching-to-sample performance in pigeons. Delay interval variation was achieved by arranging five different sets of five delays across daily sessions. In different conditions, the delays were distributed in arithmetic or logarithmic series. There was no convincing evidence for different effects on discriminability of the distributions of different delays. The mean data were better fitted by some mathematical functions than by others, but the best-fitting functions depended on the distribution of delays. In further conditions with a fixed set of five delays, discriminability was higher with a logarithmic distribution of delays than with an arithmetic distribution. This result is consistent with the treatment of the forgetting function in terms of generalization decrement.

  1. Synchronization of Markovian jumping stochastic complex networks with distributed time delays and probabilistic interval discrete time-varying delays

    Li Hongjie; Yue Dong

    2010-01-01

    The paper investigates the synchronization stability problem for a class of complex dynamical networks with Markovian jumping parameters and mixed time delays. The complex networks consist of m modes and the networks switch from one mode to another according to a Markovian chain with known transition probability. The mixed time delays are composed of discrete and distributed delays, the discrete time delay is assumed to be random and its probability distribution is known a priori. In terms of the probability distribution of the delays, the new type of system model with probability-distribution-dependent parameter matrices is proposed. Based on the stochastic analysis techniques and the properties of the Kronecker product, delay-dependent synchronization stability criteria in the mean square are derived in the form of linear matrix inequalities which can be readily solved by using the LMI toolbox in MATLAB, the solvability of derived conditions depends on not only the size of the delay, but also the probability of the delay-taking values in some intervals. Finally, a numerical example is given to illustrate the feasibility and effectiveness of the proposed method.

  2. Traveling waves in lattice differential equations with distributed maturation delay

    Hui-Ling Niu

    2013-07-01

    Full Text Available In this paper we derive a lattice model with infinite distributed delay to describe the growth of a single-species population in a 2D patchy environment with infinite number of patches connected locally by diffusion and global interaction. We consider the existence of traveling wave solutions when the birth rate is large enough that each patch can sustain a positive equilibrium. When the birth function is monotone, we prove that there exists a traveling wave solution connecting two equilibria with wave speed $c>c^*(\\theta$ by using the monotone iterative method and super and subsolution technique, where $\\theta\\in [0,2\\pi]$ is any fixed direction of propagation. When the birth function is non-monotone, we prove the existence of non-trivial traveling wave solutions by constructing two auxiliary systems satisfying quasi-monotonicity.

  3. Single-quadrature continuous-variable quantum key distribution

    Gehring, Tobias; Jacobsen, Christian Scheffmann; Andersen, Ulrik Lund

    2016-01-01

    Most continuous-variable quantum key distribution schemes are based on the Gaussian modulation of coherent states followed by continuous quadrature detection using homodyne detectors. In all previous schemes, the Gaussian modulation has been carried out in conjugate quadratures thus requiring two...... commercialization of continuous-variable quantum key distribution, provided that the low noise requirement can be achieved....

  4. Exponential stability of continuous-time and discrete-time bidirectional associative memory networks with delays

    Liang Jinling; Cao Jinde

    2004-01-01

    First, convergence of continuous-time Bidirectional Associative Memory (BAM) neural networks are studied. By using Lyapunov functionals and some analysis technique, the delay-independent sufficient conditions are obtained for the networks to converge exponentially toward the equilibrium associated with the constant input sources. Second, discrete-time analogues of the continuous-time BAM networks are formulated and studied. It is shown that the convergence characteristics of the continuous-time systems are preserved by the discrete-time analogues without any restriction imposed on the uniform discretionary step size. An illustrative example is given to demonstrate the effectiveness of the obtained results

  5. New distributions of the statistical time delay of electrical breakdown in nitrogen

    Markovic, V Lj; Gocic, S R; Stamenkovic, S N

    2006-01-01

    Two new distributions of the statistical time delay of electrical breakdown in nitrogen are reported in this paper. The Gaussian and Gauss-exponential distributions of statistical time delay have been obtained on the basis of thousands of time delay measurements on a gas tube with a plane-parallel electrode system. Distributions of the statistical time delay are theoretically founded on binomial distribution for the occurrence of initiating electrons and described by using simple analytical and numerical models. The shapes of distributions depend on the electron yields in the interelectrode space originating from residual states. It is shown that a distribution of the statistical time delay changes from exponential and Gauss-exponential to Gaussian distribution due to the influence of residual ionization

  6. Local and global stability for Lotka-Volterra systems with distributed delays and instantaneous negative feedbacks

    Faria, Teresa; Oliveira, José J.

    This paper addresses the local and global stability of n-dimensional Lotka-Volterra systems with distributed delays and instantaneous negative feedbacks. Necessary and sufficient conditions for local stability independent of the choice of the delay functions are given, by imposing a weak nondelayed diagonal dominance which cancels the delayed competition effect. The global asymptotic stability of positive equilibria is established under conditions slightly stronger than the ones required for the linear stability. For the case of monotone interactions, however, sharper conditions are presented. This paper generalizes known results for discrete delays to systems with distributed delays. Several applications illustrate the results.

  7. Velocity Distributions in Inelastic Granular Gases with Continuous Size Distributions

    Li Rui; Li Zhi-Hao; Zhang Duan-Ming

    2011-01-01

    We study by numerical simulation the property of velocity distributions of granular gases with a power-law size distribution, driven by uniform heating and boundary heating. It is found that the form of velocity distribution is primarily controlled by the restitution coefficient η and q, the ratio between the average number of heatings and the average number of collisions in the system. Furthermore, we show that uniform and boundary heating can be understood as different limits of q, with q ≫ 1 and q ≤ 1, respectively. (general)

  8. A note on exponential convergence of neural networks with unbounded distributed delays

    Chu Tianguang [Intelligent Control Laboratory, Center for Systems and Control, Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)]. E-mail: chutg@pku.edu.cn; Yang Haifeng [Intelligent Control Laboratory, Center for Systems and Control, Department of Mechanics and Engineering Science, Peking University, Beijing 100871 (China)

    2007-12-15

    This note examines issues concerning global exponential convergence of neural networks with unbounded distributed delays. Sufficient conditions are derived by exploiting exponentially fading memory property of delay kernel functions. The method is based on comparison principle of delay differential equations and does not need the construction of any Lyapunov functionals. It is simple yet effective in deriving less conservative exponential convergence conditions and more detailed componentwise decay estimates. The results of this note and [Chu T. An exponential convergence estimate for analog neural networks with delay. Phys Lett A 2001;283:113-8] suggest a class of neural networks whose globally exponentially convergent dynamics is completely insensitive to a wide range of time delays from arbitrary bounded discrete type to certain unbounded distributed type. This is of practical interest in designing fast and reliable neural circuits. Finally, an open question is raised on the nature of delay kernels for attaining exponential convergence in an unbounded distributed delayed neural network.

  9. A note on exponential convergence of neural networks with unbounded distributed delays

    Chu Tianguang; Yang Haifeng

    2007-01-01

    This note examines issues concerning global exponential convergence of neural networks with unbounded distributed delays. Sufficient conditions are derived by exploiting exponentially fading memory property of delay kernel functions. The method is based on comparison principle of delay differential equations and does not need the construction of any Lyapunov functionals. It is simple yet effective in deriving less conservative exponential convergence conditions and more detailed componentwise decay estimates. The results of this note and [Chu T. An exponential convergence estimate for analog neural networks with delay. Phys Lett A 2001;283:113-8] suggest a class of neural networks whose globally exponentially convergent dynamics is completely insensitive to a wide range of time delays from arbitrary bounded discrete type to certain unbounded distributed type. This is of practical interest in designing fast and reliable neural circuits. Finally, an open question is raised on the nature of delay kernels for attaining exponential convergence in an unbounded distributed delayed neural network

  10. FUNDAMENTAL MATRIX OF LINEAR CONTINUOUS SYSTEM IN THE PROBLEM OF ESTIMATING ITS TRANSPORT DELAY

    N. A. Dudarenko

    2014-09-01

    Full Text Available The paper deals with the problem of quantitative estimation for transport delay of linear continuous systems. The main result is received by means of fundamental matrix of linear differential equations solutions specified in the normal Cauchy form for the cases of SISO and MIMO systems. Fundamental matrix has the dual property. It means that the weight function of the system can be formed as a free motion of systems. Last one is generated by the vector of initial system conditions, which coincides with the matrix input of the system being researched. Thus, using the properties of the system- solving for fundamental matrix has given the possibility to solve the problem of estimating transport linear continuous system delay without the use of derivation procedure in hardware environment and without formation of exogenous Dirac delta function. The paper is illustrated by examples. The obtained results make it possible to solve the problem of modeling the pure delay links using consecutive chain of aperiodic links of the first order with the equal time constants. Modeling results have proved the correctness of obtained computations. Knowledge of transport delay can be used when configuring multi- component technological complexes and in the diagnosis of their possible functional degeneration.

  11. An approach to normal forms of Kuramoto model with distributed delays and the effect of minimal delay

    Niu, Ben, E-mail: niubenhit@163.com [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Guo, Yuxiao [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Jiang, Weihua [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China)

    2015-09-25

    Heterogeneous delays with positive lower bound (gap) are taken into consideration in Kuramoto model. On the Ott–Antonsen's manifold, the dynamical transitional behavior from incoherence to coherence is mediated by Hopf bifurcation. We establish a perturbation technique on complex domain, by which universal normal forms, stability and criticality of the Hopf bifurcation are obtained. Theoretically, a hysteresis loop is found near the subcritically bifurcated coherent state. With respect to Gamma distributed delay with fixed mean and variance, we find that the large gap decreases Hopf bifurcation value, induces supercritical bifurcations, avoids the hysteresis loop and significantly increases in the number of coexisting coherent states. The effect of gap is finally interpreted from the viewpoint of excess kurtosis of Gamma distribution. - Highlights: • Heterogeneously delay-coupled Kuramoto model with minimal delay is considered. • Perturbation technique on complex domain is established for bifurcation analysis. • Hysteresis phenomenon is investigated in a theoretical way. • The effect of excess kurtosis of distributed delays is discussed.

  12. Anticontrol of chaos in continuous-time systems via time-delay feedback.

    Wang, Xiao Fan; Chen, Guanrong; Yu, Xinghuo

    2000-12-01

    In this paper, a systematic design approach based on time-delay feedback is developed for anticontrol of chaos in a continuous-time system. This anticontrol method can drive a finite-dimensional, continuous-time, autonomous system from nonchaotic to chaotic, and can also enhance the existing chaos of an originally chaotic system. Asymptotic analysis is used to establish an approximate relationship between a time-delay differential equation and a discrete map. Anticontrol of chaos is then accomplished based on this relationship and the differential-geometry control theory. Several examples are given to verify the effectiveness of the methodology and to illustrate the systematic design procedure. (c) 2000 American Institute of Physics.

  13. A Realistic Framework for Delay-Tolerant Network Routing in Open Terrains with Continuous Churn

    Mahendran, Veeramani; Anirudh, Sivaraman K.; Murthy, C. Siva Ram

    The conventional analysis of Delay-Tolerant Network (DTN) routing assumes that the terrain over which nodes move is closed implying that when the nodes hit a boundary, they either wrap around or get reflected. In this work, we study the effect of relaxing this closed terrain assumption on the routing performance, where a continuous stream of nodes enter the terrain and get absorbed upon hitting the boundary.

  14. Global dissipativity of continuous-time recurrent neural networks with time delay

    Liao Xiaoxin; Wang Jun

    2003-01-01

    This paper addresses the global dissipativity of a general class of continuous-time recurrent neural networks. First, the concepts of global dissipation and global exponential dissipation are defined and elaborated. Next, the sets of global dissipativity and global exponentially dissipativity are characterized using the parameters of recurrent neural network models. In particular, it is shown that the Hopfield network and cellular neural networks with or without time delays are dissipative systems

  15. Steep Delay Discounting and Addictive Behavior: A Meta-Analysis of Continuous Associations

    Amlung, Michael; Vedelago, Lana; Acker, John; Balodis, Iris; MacKillop, James

    2016-01-01

    Aims To synthesize continuous associations between delayed reward discounting (DRD) and both addiction severity and quantity-frequency (QF); to examine moderators of these relationships; and to investigate publication bias. Methods Meta-analysis of published studies examining continuous associations between DRD and addictive behaviors. Published, peer-reviewed studies on addictive behaviors (alcohol, tobacco, cannabis, stimulants, opiates, and gambling) were identified via PubMed, MEDLINE, and PsycInfo. Studies were restricted to DRD measures of monetary gains. Random effects meta-analysis was conducted using Pearson’s r as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger’s tests, meta-regression of publication year and effect size, and imputation of missing studies. Results The primary meta-analysis revealed a small magnitude effect size that was highly significant (r = 0.14, p addictive behavior (p = 0.30) or DRD assessment (p = 0.90). Indices of publication bias suggested a modest impact of unpublished findings. Conclusions Delayed reward discounting is robustly associated with continuous measures of addiction severity and quantity-frequency. This relation is generally robust across type of addictive behavior and delayed reward discounting assessment modality. PMID:27450931

  16. Delayed Growth Suppression and Radioresistance Induced by Long-Term Continuous Gamma Irradiation.

    Nakajima, Hiroo; Furukawa, Chiharu; Chang, Young-Chae; Ogata, Hiromitsu; Magae, Junji

    2017-08-01

    Biological response to ionizing radiation depends not only on the type of radiation and dose, but also on the duration and dose rate of treatment. For a given radiation dose, the biological response may differ based on duration and dose rate. We studied the properties of two human cell lines, M059K glioma and U2OS osteosarcoma, continuously exposed to γ rays for long time periods of more than five months. Growth inhibition in both cell lines was dependent on total dose when exposed to acute radiation over several minutes, whereas prolonged growth inhibition was dependent on dose rate after continuous irradiation over several months. The minimum dose rate for growth inhibition was 53.6 mGy/h. Cell cycle analysis showed G 1 phase accumulation in cell populations continuously exposed to γ rays, and G 2 phase accumulation in cells acutely exposed to high-dose-rate γ rays. Cells continuously exposed to γ rays continued to exhibit delayed growth suppression even after one month in an environment of background radiation, and maintained a high-level expression of c-Jun and its phosphorylation forms, as well as resistance to apoptosis induced by staurosporine and chemotherapeutic agents. These delayed effects were not observed in cells acutely exposed to 5 Gy of radiation. These results suggest that optimization of the irradiation schedule is crucial for risk estimation, protection and therapeutic utilization of ionizing radiation.

  17. Stability diagrams for continuous wide-range control of two mutually delay-coupled semiconductor lasers

    Junges, Leandro; Gallas, Jason A C

    2015-01-01

    The dynamics of two mutually delay-coupled semiconductor lasers has been frequently studied experimentally, numerically, and analytically either for weak or strong detuning between the lasers. Here, we present a systematic numerical investigation spanning all detuning ranges. We report high-resolution stability diagrams for wide ranges of the main control parameters of the laser, as described by the Lang–Kobayashi model. In particular, we detail the parameter influence on dynamical performance and map the distribution of chaotic pulsations and self-generated periodic spiking with arbitrary periodicity. Special attention is given to the unfolding of regular pulse packages for both symmetric and non-symmetric configurations with respect to detuning. The influence of the delay –time on the self-organization of periodic and chaotic laser phases as a function of the coupling and detuning is also described in detail. (paper)

  18. Delay-distribution-dependent H∞ state estimation for delayed neural networks with (x,v)-dependent noises and fading channels.

    Sheng, Li; Wang, Zidong; Tian, Engang; Alsaadi, Fuad E

    2016-12-01

    This paper deals with the H ∞ state estimation problem for a class of discrete-time neural networks with stochastic delays subject to state- and disturbance-dependent noises (also called (x,v)-dependent noises) and fading channels. The time-varying stochastic delay takes values on certain intervals with known probability distributions. The system measurement is transmitted through fading channels described by the Rice fading model. The aim of the addressed problem is to design a state estimator such that the estimation performance is guaranteed in the mean-square sense against admissible stochastic time-delays, stochastic noises as well as stochastic fading signals. By employing the stochastic analysis approach combined with the Kronecker product, several delay-distribution-dependent conditions are derived to ensure that the error dynamics of the neuron states is stochastically stable with prescribed H ∞ performance. Finally, a numerical example is provided to illustrate the effectiveness of the obtained results. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Aging transition in systems of oscillators with global distributed-delay coupling.

    Rahman, B; Blyuss, K B; Kyrychko, Y N

    2017-09-01

    We consider a globally coupled network of active (oscillatory) and inactive (nonoscillatory) oscillators with distributed-delay coupling. Conditions for aging transition, associated with suppression of oscillations, are derived for uniform and gamma delay distributions in terms of coupling parameters and the proportion of inactive oscillators. The results suggest that for the uniform distribution increasing the width of distribution for the same mean delay allows aging transition to happen for a smaller coupling strength and a smaller proportion of inactive elements. For gamma distribution with sufficiently large mean time delay, it may be possible to achieve aging transition for an arbitrary proportion of inactive oscillators, as long as the coupling strength lies in a certain range.

  20. Continuous variable quantum key distribution with modulated entangled states

    Madsen, Lars S; Usenko, Vladyslav C.; Lassen, Mikael

    2012-01-01

    Quantum key distribution enables two remote parties to grow a shared key, which they can use for unconditionally secure communication over a certain distance. The maximal distance depends on the loss and the excess noise of the connecting quantum channel. Several quantum key distribution schemes...... based on coherent states and continuous variable measurements are resilient to high loss in the channel, but are strongly affected by small amounts of channel excess noise. Here we propose and experimentally address a continuous variable quantum key distribution protocol that uses modulated fragile...... entangled states of light to greatly enhance the robustness to channel noise. We experimentally demonstrate that the resulting quantum key distribution protocol can tolerate more noise than the benchmark set by the ideal continuous variable coherent state protocol. Our scheme represents a very promising...

  1. JENDL-4.0 benchmarking for effective delayed neutron fraction with a continuous-energy Monte Carlo code MVP

    Nagaya, Yasunobu

    2013-01-01

    Benchmark calculations with a continuous-energy Monte Carlo code have been performed for delayed neutron data of JENDL-4.0. JENDL-4.0 gives good prediction for the effective delayed neutron fraction in the present benchmarks but further detailed analysis is required for some cores. (author)

  2. Global exponential stability of mixed discrete and distributively delayed cellular neural network

    Yao Hong-Xing; Zhou Jia-Yan

    2011-01-01

    This paper concernes analysis for the global exponential stability of a class of recurrent neural networks with mixed discrete and distributed delays. It first proves the existence and uniqueness of the balance point, then by employing the Lyapunov—Krasovskii functional and Young inequality, it gives the sufficient condition of global exponential stability of cellular neural network with mixed discrete and distributed delays, in addition, the example is provided to illustrate the applicability of the result. (general)

  3. Stability analysis of impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms

    Li Zuoan; Li Kelin

    2009-01-01

    In this paper, we investigate a class of impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms. By employing the delay differential inequality with impulsive initial conditions and M-matrix theory, we find some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive fuzzy cellular neural networks with distributed delays and reaction-diffusion terms. In particular, the estimate of the exponential converging index is also provided, which depends on the system parameters. An example is given to show the effectiveness of the results obtained here.

  4. The rates and time-delay distribution of multiply imaged supernovae behind lensing clusters

    Li, Xue; Hjorth, Jens; Richard, Johan

    2012-11-01

    Time delays of gravitationally lensed sources can be used to constrain the mass model of a deflector and determine cosmological parameters. We here present an analysis of the time-delay distribution of multiply imaged sources behind 17 strong lensing galaxy clusters with well-calibrated mass models. We find that for time delays less than 1000 days, at z = 3.0, their logarithmic probability distribution functions are well represented by P(log Δt) = 5.3 × 10-4Δttilde beta/M2502tilde beta, with tilde beta = 0.77, where M250 is the projected cluster mass inside 250 kpc (in 1014M⊙), and tilde beta is the power-law slope of the distribution. The resultant probability distribution function enables us to estimate the time-delay distribution in a lensing cluster of known mass. For a cluster with M250 = 2 × 1014M⊙, the fraction of time delays less than 1000 days is approximately 3%. Taking Abell 1689 as an example, its dark halo and brightest galaxies, with central velocity dispersions σ>=500kms-1, mainly produce large time delays, while galaxy-scale mass clumps are responsible for generating smaller time delays. We estimate the probability of observing multiple images of a supernova in the known images of Abell 1689. A two-component model of estimating the supernova rate is applied in this work. For a magnitude threshold of mAB = 26.5, the yearly rate of Type Ia (core-collapse) supernovae with time delays less than 1000 days is 0.004±0.002 (0.029±0.001). If the magnitude threshold is lowered to mAB ~ 27.0, the rate of core-collapse supernovae suitable for time delay observation is 0.044±0.015 per year.

  5. Distributed continuous energy scheduling for dynamic virtual power plants

    Niesse, Astrid

    2015-01-01

    This thesis presents DynaSCOPE as distributed control method for continuous energy scheduling for dynamic virtual power plants (DVPP). DVPPs aggregate the flexibility of distributed energy units to address current energy markets. As an extension of the Virtual Power Plant concept they show high dynamics in aggregation and operation of energy units. Whereas operation schedules are set up for all energy units in a day-ahead planning procedure, incidents may render these schedules infeasible during execution, like deviation from prognoses or outages. Thus, a continuous scheduling process is needed to ensure product fulfillment. With DynaSCOPE, software agents representing single energy units solve this problem in a completely distributed heuristic approach. Using a stepped concept, several damping mechanisms are applied to allow minimum disturbance while continuously trying to fulfill the product as contracted at the market.

  6. On the continuity of the stationary state distribution of DPCM

    Naraghi-Pour, Morteza; Neuhoff, David L.

    1990-03-01

    Continuity and singularity properties of the stationary state distribution of differential pulse code modulation (DPCM) are explored. Two-level DPCM (i.e., delta modulation) operating on a first-order autoregressive source is considered, and it is shown that, when the magnitude of the DPCM prediciton coefficient is between zero and one-half, the stationary state distribution is singularly continuous; i.e., it is not discrete but concentrates on an uncountable set with a Lebesgue measure of zero. Consequently, it cannot be represented with a probability density function. For prediction coefficients with magnitude greater than or equal to one-half, the distribution is pure, i.e., either absolutely continuous and representable with a density function, or singular. This problem is compared to the well-known and still substantially unsolved problem of symmetric Bernoulli convolutions.

  7. Numerical Bifurcation Analysis of Delayed Recycle Stream in a Continuously Stirred Tank Reactor

    Gangadhar, Nalwala Rohitbabu; Balasubramanian, Periyasamy

    2010-10-01

    In this paper, we present the stability analysis of delay differential equations which arise as a result of transportation lag in the CSTR-mechanical separator recycle system. A first order irreversible elementary reaction is considered to model the system and is governed by the delay differential equations. The DDE-BIFTOOL software package is used to analyze the stability of the delay system. The present analysis reveals that the system exhibits delay independent stability for isothermal operation of the CSTR. In the absence of delay, the system is dynamically unstable for non-isothermal operation of the CSTR, and as a result of delay, the system exhibits delay dependent stability.

  8. Structured populations with distributed recruitment : from PDE to delay formulation

    Calsina, Àngel; Diekmann, Odo; Farkas, József Z.

    2016-01-01

    In this work, first, we consider a physiologically structured population model with a distributed recruitment process. That is, our model allows newly recruited individuals to enter the population at all possible individual states, in principle. The model can be naturally formulated as a first-order

  9. Distributed software framework and continuous integration in hydroinformatics systems

    Zhou, Jianzhong; Zhang, Wei; Xie, Mengfei; Lu, Chengwei; Chen, Xiao

    2017-08-01

    When encountering multiple and complicated models, multisource structured and unstructured data, complex requirements analysis, the platform design and integration of hydroinformatics systems become a challenge. To properly solve these problems, we describe a distributed software framework and it’s continuous integration process in hydroinformatics systems. This distributed framework mainly consists of server cluster for models, distributed database, GIS (Geographic Information System) servers, master node and clients. Based on it, a GIS - based decision support system for joint regulating of water quantity and water quality of group lakes in Wuhan China is established.

  10. How Can Histograms Be Useful for Introducing Continuous Probability Distributions?

    Derouet, Charlotte; Parzysz, Bernard

    2016-01-01

    The teaching of probability has changed a great deal since the end of the last century. The development of technologies is indeed part of this evolution. In France, continuous probability distributions began to be studied in 2002 by scientific 12th graders, but this subject was marginal and appeared only as an application of integral calculus.…

  11. Multiple-parameter bifurcation analysis in a Kuramoto model with time delay and distributed shear

    Niu, Ben; Zhang, Jiaming; Wei, Junjie

    2018-05-01

    In this paper, time delay effect and distributed shear are considered in the Kuramoto model. On the Ott-Antonsen's manifold, through analyzing the associated characteristic equation of the reduced functional differential equation, the stability boundary of the incoherent state is derived in multiple-parameter space. Moreover, very rich dynamical behavior such as stability switches inducing synchronization switches can occur in this equation. With the loss of stability, Hopf bifurcating coherent states arise, and the criticality of Hopf bifurcations is determined by applying the normal form theory and the center manifold theorem. On one hand, theoretical analysis indicates that the width of shear distribution and time delay can both eliminate the synchronization then lead the Kuramoto model to incoherence. On the other, time delay can induce several coexisting coherent states. Finally, some numerical simulations are given to support the obtained results where several bifurcation diagrams are drawn, and the effect of time delay and shear is discussed.

  12. Sharp conditions for global stability of Lotka-Volterra systems with distributed delays

    Faria, Teresa

    We give a criterion for the global attractivity of a positive equilibrium of n-dimensional non-autonomous Lotka-Volterra systems with distributed delays. For a class of autonomous Lotka-Volterra systems, we show that such a criterion is sharp, in the sense that it provides necessary and sufficient conditions for the global asymptotic stability independently of the choice of the delay functions. The global attractivity of positive equilibria is established by imposing a diagonal dominance of the instantaneous negative feedback terms, and relies on auxiliary results showing the boundedness of all positive solutions. The paper improves and generalizes known results in the literature, namely by considering systems with distributed delays rather than discrete delays.

  13. On global stability criterion for neural networks with discrete and distributed delays

    Park, Ju H.

    2006-01-01

    Based on the Lyapunov functional stability analysis for differential equations and the linear matrix inequality (LMI) optimization approach, a new delay-dependent criterion for neural networks with discrete and distributed delays is derived to guarantee global asymptotic stability. The criterion is expressed in terms of LMIs, which can be solved easily by various convex optimization algorithms. Some numerical examples are given to show the effectiveness of proposed method

  14. Analysis of Distributed Consensus Time Synchronization with Gaussian Delay over Wireless Sensor Networks

    Xiong Gang

    2009-01-01

    Full Text Available This paper presents theoretical results on the convergence of the distributed consensus timing synchronization (DCTS algorithm for wireless sensor networks assuming general Gaussian delay between nodes. The asymptotic expectation and mean square of the global synchronization error are computed. The results lead to the definition of a time delay balanced network in which average timing consensus between nodes can be achieved despite random delays. Several structured network architectures are studied as examples, and their associated simulation results are used to validate analytical findings.

  15. Dynamic autofocus for continuous-scanning time-delay-and-integration image acquisition in automated microscopy.

    Bravo-Zanoguera, Miguel E; Laris, Casey A; Nguyen, Lam K; Oliva, Mike; Price, Jeffrey H

    2007-01-01

    Efficient image cytometry of a conventional microscope slide means rapid acquisition and analysis of 20 gigapixels of image data (at 0.3-microm sampling). The voluminous data motivate increased acquisition speed to enable many biomedical applications. Continuous-motion time-delay-and-integrate (TDI) scanning has the potential to speed image acquisition while retaining sensitivity, but the challenge of implementing high-resolution autofocus operating simultaneously with acquisition has limited its adoption. We develop a dynamic autofocus system for this need using: 1. a "volume camera," consisting of nine fiber optic imaging conduits to charge-coupled device (CCD) sensors, that acquires images in parallel from different focal planes, 2. an array of mixed analog-digital processing circuits that measure the high spatial frequencies of the multiple image streams to create focus indices, and 3. a software system that reads and analyzes the focus data streams and calculates best focus for closed feedback loop control. Our system updates autofocus at 56 Hz (or once every 21 microm of stage travel) to collect sharply focused images sampled at 0.3x0.3 microm(2)/pixel at a stage speed of 2.3 mms. The system, tested by focusing in phase contrast and imaging long fluorescence strips, achieves high-performance closed-loop image-content-based autofocus in continuous scanning for the first time.

  16. Distributed public key schemes secure against continual leakage

    Akavia, Adi; Goldwasser, Shafi; Hazay, Carmit

    2012-01-01

    -secure against continual memory leakage. Our DPKE scheme also implies a secure storage system on leaky devices, where a value s can be secretely stored on devices that continually leak information about their internal state to an external attacker. The devices go through a periodic refresh protocol......In this work we study distributed public key schemes secure against continual memory leakage. The secret key will be shared among two computing devices communicating over a public channel, and the decryption operation will be computed by a simple 2-party protocol between the devices. Similarly...... against continual memory leakage, under the Bilinear Decisional Diffie-Hellman and $2$-linear assumptions. Our schemes have the following properties: 1. Our DPKE and DIBE schemes tolerate leakage at all times, including during refresh. During refresh the tolerated leakage is a (1/2-o (1),1)-fraction...

  17. Design and FPGA Implementation of Variable Cutoff Frequency Filter based on Continuously Variable Fractional Delay Structure and Interpolation Technique

    Sumedh Dhabu

    2015-09-01

    Full Text Available This paper presents the design and FPGA implementation of interpolated continuously variable fractional delay structure based filter (ICVFD filter with fine control over the cutoff frequency. In the ICVFD filter, each unit delay of the prototype lowpass filter is replaced by a continuously variable fractional delay (CVFD element proposed in this paper. The CVFD element requires the same number of multiplications as that of the second-order fractional delay structure used in the existing fractional delay structure based variable filter (FDS based filter, however it provides fractional delays corresponding to the higher-order fractional delay structures. Hence, the proposed ICVFD filter provides wider cutoff frequency range compared to the FDS based filter. The ICVFD filter is also capable of providing variable bandpass and highpass responses. We use two-stage approach for the FPGA implementation of the ICVFD filter. First, we use pipelining stages to shorten the critical path and improve the operating frequency. Then, we make use of specific hardware resource, i.e. RAM-based Shift Register (SRL to further improve the operating frequency and resource usage.

  18. Continuous Variable Quantum Key Distribution with a Noisy Laser

    Jacobsen, Christian Scheffmann; Gehring, Tobias; Andersen, Ulrik Lund

    2015-01-01

    Existing experimental implementations of continuous-variable quantum key distribution require shot-noise limited operation, achieved with shot-noise limited lasers. However, loosening this requirement on the laser source would allow for cheaper, potentially integrated systems. Here, we implement...... a theoretically proposed prepare-and-measure continuous-variable protocol and experimentally demonstrate the robustness of it against preparation noise stemming for instance from technical laser noise. Provided that direct reconciliation techniques are used in the post-processing we show that for small distances...

  19. Occam factors and model independent Bayesian learning of continuous distributions

    Nemenman, Ilya; Bialek, William

    2002-01-01

    Learning of a smooth but nonparametric probability density can be regularized using methods of quantum field theory. We implement a field theoretic prior numerically, test its efficacy, and show that the data and the phase space factors arising from the integration over the model space determine the free parameter of the theory ('smoothness scale') self-consistently. This persists even for distributions that are atypical in the prior and is a step towards a model independent theory for learning continuous distributions. Finally, we point out that a wrong parametrization of a model family may sometimes be advantageous for small data sets

  20. Cell-cycle distributions and radiation responses of Chinese hamster cells cultured continuously under hypoxic conditions

    Tokita, N.; Carpenter, S.G.; Raju, M.R.

    1984-01-01

    Cell-cycle distributions were measured by flow cytometry for Chinese hamster (CHO) cells cultured continuously under hypoxic conditions. DNA histograms showed an accumulation of cells in the early S phase followed by a traverse delay through the S phase, and a G 2 block. During hypoxic culturing, cell viability decreased rapidly to less than 0.1% at 120 h. Radiation responses for cells cultured under these conditions showed an extreme radioresistance at 72 h. Results suggest that hypoxia induces a condition similar to cell synchrony which itself changes the radioresistance of hypoxic cells. (author)

  1. Evaluation of performance of distributed delay model for chemotherapy-induced myelosuppression.

    Krzyzanski, Wojciech; Hu, Shuhua; Dunlavey, Michael

    2018-04-01

    The distributed delay model has been introduced that replaces the transit compartments in the classic model of chemotherapy-induced myelosuppression with a convolution integral. The maturation of granulocyte precursors in the bone marrow is described by the gamma probability density function with the shape parameter (ν). If ν is a positive integer, the distributed delay model coincides with the classic model with ν transit compartments. The purpose of this work was to evaluate performance of the distributed delay model with particular focus on model deterministic identifiability in the presence of the shape parameter. The classic model served as a reference for comparison. Previously published white blood cell (WBC) count data in rats receiving bolus doses of 5-fluorouracil were fitted by both models. The negative two log-likelihood objective function (-2LL) and running times were used as major markers of performance. Local sensitivity analysis was done to evaluate the impact of ν on the pharmacodynamics response WBC. The ν estimate was 1.46 with 16.1% CV% compared to ν = 3 for the classic model. The difference of 6.78 in - 2LL between classic model and the distributed delay model implied that the latter performed significantly better than former according to the log-likelihood ratio test (P = 0.009), although the overall performance was modestly better. The running times were 1 s and 66.2 min, respectively. The long running time of the distributed delay model was attributed to computationally intensive evaluation of the convolution integral. The sensitivity analysis revealed that ν strongly influences the WBC response by controlling cell proliferation and elimination of WBCs from the circulation. In conclusion, the distributed delay model was deterministically identifiable from typical cytotoxic data. Its performance was modestly better than the classic model with significantly longer running time.

  2. Wigner time-delay distribution in chaotic cavities and freezing transition.

    Texier, Christophe; Majumdar, Satya N

    2013-06-21

    Using the joint distribution for proper time delays of a chaotic cavity derived by Brouwer, Frahm, and Beenakker [Phys. Rev. Lett. 78, 4737 (1997)], we obtain, in the limit of the large number of channels N, the large deviation function for the distribution of the Wigner time delay (the sum of proper times) by a Coulomb gas method. We show that the existence of a power law tail originates from narrow resonance contributions, related to a (second order) freezing transition in the Coulomb gas.

  3. Global asymptotic stability analysis of bidirectional associative memory neural networks with distributed delays and impulse

    Huang Zaitang; Luo Xiaoshu; Yang Qigui

    2007-01-01

    Many systems existing in physics, chemistry, biology, engineering and information science can be characterized by impulsive dynamics caused by abrupt jumps at certain instants during the process. These complex dynamical behaviors can be model by impulsive differential system or impulsive neural networks. This paper formulates and studies a new model of impulsive bidirectional associative memory (BAM) networks with finite distributed delays. Several fundamental issues, such as global asymptotic stability and existence and uniqueness of such BAM neural networks with impulse and distributed delays, are established

  4. Continuous-variable quantum key distribution with Gaussian source noise

    Shen Yujie; Peng Xiang; Yang Jian; Guo Hong

    2011-01-01

    Source noise affects the security of continuous-variable quantum key distribution (CV QKD) and is difficult to analyze. We propose a model to characterize Gaussian source noise through introducing a neutral party (Fred) who induces the noise with a general unitary transformation. Without knowing Fred's exact state, we derive the security bounds for both reverse and direct reconciliations and show that the bound for reverse reconciliation is tight.

  5. Generating Li–Yorke chaos in a stable continuous-time T–S fuzzy model via time-delay feedback control

    Qiu-Ye, Sun; Hua-Guang, Zhang; Yan, Zhao

    2010-01-01

    This paper investigates the chaotification problem of a stable continuous-time T–S fuzzy system. A simple nonlinear state time-delay feedback controller is designed by parallel distributed compensation technique. Then, the asymptotically approximate relationship between the controlled continuous-time T–S fuzzy system with time-delay and a discrete-time T–S fuzzy system is established. Based on the discrete-time T–S fuzzy system, it proves that the chaos in the discrete-time T–S fuzzy system satisfies the Li–Yorke definition by choosing appropriate controller parameters via the revised Marotto theorem. Finally, the effectiveness of the proposed chaotic anticontrol method is verified by a practical example. (general)

  6. Categorical working memory representations are used in delayed estimation of continuous colors.

    Hardman, Kyle O; Vergauwe, Evie; Ricker, Timothy J

    2017-01-01

    In the last decade, major strides have been made in understanding visual working memory through mathematical modeling of color production responses. In the delayed color estimation task (Wilken & Ma, 2004), participants are given a set of colored squares to remember, and a few seconds later asked to reproduce those colors by clicking on a color wheel. The degree of error in these responses is characterized with mathematical models that estimate working memory precision and the proportion of items remembered by participants. A standard mathematical model of color memory assumes that items maintained in memory are remembered through memory for precise details about the particular studied shade of color. We contend that this model is incomplete in its present form because no mechanism is provided for remembering the coarse category of a studied color. In the present work, we remedy this omission and present a model of visual working memory that includes both continuous and categorical memory representations. In 2 experiments, we show that our new model outperforms this standard modeling approach, which demonstrates that categorical representations should be accounted for by mathematical models of visual working memory. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  7. Categorical Working Memory Representations are used in Delayed Estimation of Continuous Colors

    Hardman, Kyle O; Vergauwe, Evie; Ricker, Timothy J

    2016-01-01

    In the last decade, major strides have been made in understanding visual working memory through mathematical modeling of color production responses. In the delayed color estimation task (Wilken & Ma, 2004), participants are given a set of colored squares to remember and a few seconds later asked to reproduce those colors by clicking on a color wheel. The degree of error in these responses is characterized with mathematical models that estimate working memory precision and the proportion of items remembered by participants. A standard mathematical model of color memory assumes that items maintained in memory are remembered through memory for precise details about the particular studied shade of color. We contend that this model is incomplete in its present form because no mechanism is provided for remembering the coarse category of a studied color. In the present work we remedy this omission and present a model of visual working memory that includes both continuous and categorical memory representations. In two experiments we show that our new model outperforms this standard modeling approach, which demonstrates that categorical representations should be accounted for by mathematical models of visual working memory. PMID:27797548

  8. Continuous quality improvement process pin-points delays, speeds STEMI patients to life-saving treatment.

    2011-11-01

    Using a multidisciplinary team approach, the University of California, San Diego, Health System has been able to significantly reduce average door-to-balloon angioplasty times for patients with the most severe form of heart attacks, beating national recommendations by more than a third. The multidisciplinary team meets monthly to review all cases involving patients with ST-segment-elevation myocardial infarctions (STEMI) to see where process improvements can be made. Using this continuous quality improvement (CQI) process, the health system has reduced average door-to-balloon times from 120 minutes to less than 60 minutes, and administrators are now aiming for further progress. Among the improvements instituted by the multidisciplinary team are the implementation of a "greeter" with enough clinical expertise to quickly pick up on potential STEMI heart attacks as soon as patients walk into the ED, and the purchase of an electrocardiogram (EKG) machine so that evaluations can be done in the triage area. ED staff have prepared "STEMI" packets, including items such as special IV tubing and disposable leads, so that patients headed for the catheterization laboratory are prepared to undergo the procedure soon after arrival. All the clocks and devices used in the ED are synchronized so that analysts can later review how long it took to complete each step of the care process. Points of delay can then be targeted for improvement.

  9. Distributed Consensus of Stochastic Delayed Multi-agent Systems Under Asynchronous Switching.

    Wu, Xiaotai; Tang, Yang; Cao, Jinde; Zhang, Wenbing

    2016-08-01

    In this paper, the distributed exponential consensus of stochastic delayed multi-agent systems with nonlinear dynamics is investigated under asynchronous switching. The asynchronous switching considered here is to account for the time of identifying the active modes of multi-agent systems. After receipt of confirmation of mode's switching, the matched controller can be applied, which means that the switching time of the matched controller in each node usually lags behind that of system switching. In order to handle the coexistence of switched signals and stochastic disturbances, a comparison principle of stochastic switched delayed systems is first proved. By means of this extended comparison principle, several easy to verified conditions for the existence of an asynchronously switched distributed controller are derived such that stochastic delayed multi-agent systems with asynchronous switching and nonlinear dynamics can achieve global exponential consensus. Two examples are given to illustrate the effectiveness of the proposed method.

  10. Assessment of energy supply and continuity of service in distribution network with renewable distributed generation

    Abdullah, M.A.; Agalgaonkar, A.P.; Muttaqi, K.M.

    2014-01-01

    Highlights: • Difficulties in assessing distribution network adequacy with DG are addressed. • Indices are proposed to assess adequacy of energy supply and service continuity. • Analytical methodology is developed to assess the proposed indices. • Concept of joint probability distribution of demand and generation is applied. - Abstract: Continuity of electricity supply with renewable distributed generation (DG) is a topical issue for distribution system planning and operation, especially due to the stochastic nature of power generation and time varying load demand. The conventional adequacy and reliability analysis methods related to bulk generation systems cannot be applied directly for the evaluation of adequacy criteria such as ‘energy supply’ and ‘continuity of service’ for distribution networks embedded with renewable DG. In this paper, new indices highlighting ‘available supply capacity’ and ‘continuity of service’ are proposed for ‘energy supply’ and ‘continuation of service’ evaluation of generation-rich distribution networks, and analytical techniques are developed for their quantification. A probability based analytical method has been developed using the joint probability of the demand and generation, and probability distributions of the proposed indices have been used to evaluate the network adequacy in energy supply and service continuation. A data clustering technique has been used to evaluate the joint probability between coincidental demand and renewable generation. Time sequential Monte Carlo simulation has been used to compare the results obtained using the proposed analytical method. A standard distribution network derived from Roy Billinton test system and a practical radial distribution network have been used to test the proposed method and demonstrate the estimation of the well-being of a system for hosting renewable DG units. It is found that renewable DG systems improve the ‘energy supply’ and ‘continuity

  11. Continuous electroencephalography predicts delayed cerebral ischemia after subarachnoid hemorrhage: A prospective study of diagnostic accuracy.

    Rosenthal, Eric S; Biswal, Siddharth; Zafar, Sahar F; O'Connor, Kathryn L; Bechek, Sophia; Shenoy, Apeksha V; Boyle, Emily J; Shafi, Mouhsin M; Gilmore, Emily J; Foreman, Brandon P; Gaspard, Nicolas; Leslie-Mazwi, Thabele M; Rosand, Jonathan; Hoch, Daniel B; Ayata, Cenk; Cash, Sydney S; Cole, Andrew J; Patel, Aman B; Westover, M Brandon

    2018-04-16

    Delayed cerebral ischemia (DCI) is a common, disabling complication of subarachnoid hemorrhage (SAH). Preventing DCI is a key focus of neurocritical care, but interventions carry risk and cannot be applied indiscriminately. Although retrospective studies have identified continuous electroencephalographic (cEEG) measures associated with DCI, no study has characterized the accuracy of cEEG with sufficient rigor to justify using it to triage patients to interventions or clinical trials. We therefore prospectively assessed the accuracy of cEEG for predicting DCI, following the Standards for Reporting Diagnostic Accuracy Studies. We prospectively performed cEEG in nontraumatic, high-grade SAH patients at a single institution. The index test consisted of clinical neurophysiologists prospectively reporting prespecified EEG alarms: (1) decreasing relative alpha variability, (2) decreasing alpha-delta ratio, (3) worsening focal slowing, or (4) late appearing epileptiform abnormalities. The diagnostic reference standard was DCI determined by blinded, adjudicated review. Primary outcome measures were sensitivity and specificity of cEEG for subsequent DCI, determined by multistate survival analysis, adjusted for baseline risk. One hundred three of 227 consecutive patients were eligible and underwent cEEG monitoring (7.7-day mean duration). EEG alarms occurred in 96.2% of patients with and 19.6% without subsequent DCI (1.9-day median latency, interquartile range = 0.9-4.1). Among alarm subtypes, late onset epileptiform abnormalities had the highest predictive value. Prespecified EEG findings predicted DCI among patients with low (91% sensitivity, 83% specificity) and high (95% sensitivity, 77% specificity) baseline risk. cEEG accurately predicts DCI following SAH and may help target therapies to patients at highest risk of secondary brain injury. Ann Neurol 2018. © 2018 American Neurological Association.

  12. Spherical reconciliation for a continuous-variable quantum key distribution

    Lu Zhao; Shi Jian-Hong; Li Feng-Guang

    2017-01-01

    Information reconciliation is a significant step for a continuous-variable quantum key distribution (CV-QKD) system. We propose a reconciliation method that allows two authorized parties to extract a consistent and secure binary key in a CV-QKD protocol, which is based on Gaussian-modulated coherent states and homodyne detection. This method named spherical reconciliation is based on spherical quantization and non-binary low-density parity-check (LDPC) codes. With the suitable signal-to-noise ratio (SNR) and code rate of non-binary LDPC codes, spherical reconciliation algorithm has a high efficiency and can extend the transmission distance of CV-QKD. (paper)

  13. Absolute continuity of the distribution of some Markov geometric series

    Ai-hua; FAN; Ji-hong; ZHANG

    2007-01-01

    Let (∈n)≥0 be the Markov chain of two states with respect to the probability measure of the maximal entropy on the subshift space ∑A defined by Fibonacci incident matrix A.We consider the measure μλ of the probability distribution of the random series ∑∞n=0 εnλn (0 <λ< 1).It is proved that μλ is singular if λ∈ (0,√5-1/2) and that μλ is absolutely continuous for almost all λ∈ (√5-1/2,0.739).

  14. A dynamic control water distribution model of steel in continuous casting

    Fu Jianxun; Hwang, Weng-Sing; Tsai, De-Chang; Tsai, Ming Hsiu; Wang, Chien-Hsun

    2012-01-01

    After investigation in many continuous casting shop of steel, a dynamic water distribution model is proposed for flexible control on secondary cooling in continuous casting. In this model, the water cooling intensity is determined by the model casting speed instead of the real casting speed. When the casting speed is steady, the model casting speed is equal to the real casting speed. When the real casting speed is changing, the model casting speed according to calculating algorithm to adjust and approaches to the real one, but there is a time delay between them, so it can avoid the slab surface temperature fluctuated due to casting speed changes. The secondary cooling can be dynamically controlled by monitoring the model casting speed. The compare of the simulation results and the measured results reveals that the temperature field and thickness of slab shell in simulations agree very well with the real production situations.

  15. Probability distribution of wave packet delay time for strong overlapping of resonance levels

    Lyuboshits, V.L.

    1983-01-01

    Time behaviour of nuclear reactions in the case of high level densities is investigated basing on the theory of overlapping resonances. In the framework of a model of n equivalent channels an analytical expression is obtained for the probability distribution function for wave packet delay time at the compound nucleus production. It is shown that at strong overlapping of the resonance levels the relative fluctuation of the delay time is small at the stage of compound nucleus production. A possible increase in the duration of nuclear reactions with the excitation energy rise is discussed

  16. Convergence dynamics of hybrid bidirectional associative memory neural networks with distributed delays

    Liao Xiaofeng; Wong, K.-W.; Yang Shizhong

    2003-01-01

    In this Letter, the characteristics of the convergence dynamics of hybrid bidirectional associative memory neural networks with distributed transmission delays are studied. Without assuming the symmetry of synaptic connection weights and the monotonicity and differentiability of activation functions, the Lyapunov functionals are constructed and the generalized Halanay-type inequalities are employed to derive the delay-independent sufficient conditions under which the networks converge exponentially to the equilibria associated with temporally uniform external inputs. Some examples are given to illustrate the correctness of our results

  17. Global Exponential Stability of Periodic Oscillation for Nonautonomous BAM Neural Networks with Distributed Delay

    Hongli Liu

    2009-01-01

    Full Text Available We derive a new criterion for checking the global stability of periodic oscillation of bidirectional associative memory (BAM neural networks with periodic coefficients and distributed delay, and find that the criterion relies on the Lipschitz constants of the signal transmission functions, weights of the neural network, and delay kernels. The proposed model transforms the original interacting network into matrix analysis problem which is easy to check, thereby significantly reducing the computational complexity and making analysis of periodic oscillation for even large-scale networks.

  18. Channel access delay and buffer distribution of two-user opportunistic scheduling schemes in wireless networks

    Hossain, Md Jahangir

    2010-07-01

    In our earlier works, we proposed rate adaptive hierarchical modulation-assisted two-best user opportunistic scheduling (TBS) and hybrid two-user scheduling (HTS) schemes. The proposed schemes are innovative in the sense that they include a second user in the transmission opportunistically using hierarchical modulations. As such the frequency of information access of the users increases without any degradation of the system spectral efficiency (SSE) compared to the classical opportunistic scheduling scheme. In this paper, we analyze channel access delay of an incoming packet at the base station (BS) buffer when our proposed TBS and HTS schemes are employed at the BS. Specifically, using a queuing analytic model we derive channel access delay as well as buffer distribution of the packets that wait at BS buffer for down-link (DL) transmission. We compare performance of the TBS and HTS schemes with that of the classical single user opportunistic schemes namely, absolute carrier-to-noise ratio (CNR)-based single user scheduling (ASS) and normalized CNR-based single user scheduling (NSS). For an independent and identically distributed (i.i.d.) fading environment, our proposed scheme can improve packet\\'s access delay performance compared to the ASS. Selected numerical results in an independent but non-identically distributed (i.n.d.) fading environment show that our proposed HTS achieves overall good channel access delay performance. © 2010 IEEE.

  19. Multiagent System-Based Distributed Coordinated Control for Radial DC Microgrid Considering Transmission Time Delays

    Dou, Chun-Xia; Yue, Dong; Guerrero, Josep M.

    2017-01-01

    This paper focuses on a multi-agent based distributed coordinated control for radial DC microgrid considering trans-mission time delays. Firstly, a two-level multi-agent system is constructed, where local control is formulated based on local states and executed by means of the first-level agent......, and dis-tributed coordinated control law is formulated based on wide-area information and executed by means of the secondary- level agent in order to improve the voltage control performances. Afterwards, the research mainly focuses on designing the local controller and the distributed coordinated...

  20. A robust control strategy for a class of distributed network with transmission delays

    Vahid Naghavi, S.; A. Safavi, A.; Khooban, Mohammad Hassan

    2016-01-01

    Purpose The purpose of this paper is to concern the design of a robust model predictive controller for distributed networked systems with transmission delays. Design/methodology/approach The overall system is composed of a number of interconnected nonlinear subsystems with time-varying transmission...... as an optimization problem of a “worst-case” objective function over an infinite moving horizon. Findings The aim is to propose control synthesis approach that depends on nonlinearity and time varying delay characteristics. The MPC problem is represented in a time varying delayed state feedback structure....... Then the synthesis sufficient condition is provided in the form of a linear matrix inequality (LMI) optimization and is solved online at each time instant. In the rest, an LMI-based decentralized observer-based robust model predictive control strategy is proposed. Originality/value The authors develop RMPC...

  1. Oscillation for equations with positive and negative coefficients and with distributed delay I: General results

    Leonid Berezansky

    2003-02-01

    Full Text Available We study a scalar delay differential equation with a bounded distributed delay, $$ dot{x}(t+ int_{h(t}^t x(s,d_s R(t,s - int_{g(t}^t x(s,d_s T(t,s=0, $$ where $R(t,s$, $T(t,s$ are nonnegative nondecreasing in $s$ for any $t$, $$ R(t,h(t=T(t,g(t=0, quad R(t,s geq T(t,s. $$ We establish a connection between non-oscillation of this differential equation and the corresponding differential inequalities, and between positiveness of the fundamental function and the existence of a nonnegative solution for a nonlinear integral inequality that constructed explicitly. We also present comparison theorems, and explicit non-oscillation and oscillation results. In a separate publication (part II, we will consider applications of this theory to differential equations with several concentrated delays, integrodifferential, and mixed equations.

  2. The application of convolution-based statistical model on the electrical breakdown time delay distributions in neon

    Maluckov, Cedomir A.; Karamarkovic, Jugoslav P.; Radovic, Miodrag K.; Pejovic, Momcilo M.

    2004-01-01

    The convolution-based model of the electrical breakdown time delay distribution is applied for statistical analysis of experimental results obtained in neon-filled diode tube at 6.5 mbar. At first, the numerical breakdown time delay density distributions are obtained by stochastic modeling as the sum of two independent random variables, the electrical breakdown statistical time delay with exponential, and discharge formative time with Gaussian distribution. Then, the single characteristic breakdown time delay distribution is obtained as the convolution of these two random variables with previously determined parameters. These distributions show good correspondence with the experimental distributions, obtained on the basis of 1000 successive and independent measurements. The shape of distributions is investigated, and corresponding skewness and kurtosis are plotted, in order to follow the transition from Gaussian to exponential distribution

  3. A monolithic constant-fraction discriminator using distributed R-C delay-line shaping

    Simpson, M.L.; Young, G.R.; Xu, M.

    1995-01-01

    A monolithic, CMOS, constant-fraction discriminator (CFD) was fabricated in the Orbit Semiconductor, 1.2 μ N-well process. This circuit uses an on-chip, distributed, R-C delay-line to realize the constant-fraction shaping. The delay-line is constructed from a narrow, 500-μ serpentine layer of polysilicon above a wide, grounded, second layer of polysilicon. This R-C delay-line generates about 1.1 ns of delay for 5 ns risetime signals with a slope degradation of only ≅ 15% and an amplitude reduction of about 6.1%. The CFD also features an automatic walk adjustment. The entire circuit, including the delay line, has a 200 μ pitch and is 950 μ long. The walk for a 5 ns risetime signal was measured as ± 100 ps over the 100:1 dynamic range from -15 mV to -1.5 mV. to -1.5 V. The CFD consumes 15 mW

  4. Improved Delay-Dependent Robust Stability Criteria for a Class of Uncertain Neutral Type Lur’e Systems with Discrete and Distributed Delays

    Kaibo Shi

    2014-01-01

    Full Text Available This paper is concerned with the problem of delay-dependent robust stability analysis for a class of uncertain neutral type Lur’e systems with mixed time-varying delays. The system has not only time-varying uncertainties and sector-bounded nonlinearity, but also discrete and distributed delays, which has never been discussed in the previous literature. Firstly, by employing one effective mathematical technique, some less conservative delay-dependent stability results are established without employing the bounding technique and the mode transformation approach. Secondly, by constructing an appropriate new type of Lyapunov-Krasovskii functional with triple terms, improved delay-dependent stability criteria in terms of linear matrix inequalities (LMIs derived in this paper are much brief and valid. Furthermore, both nonlinearities located in finite sector and infinite one have been also fully taken into account. Finally, three numerical examples are presented to illustrate lesser conservatism and the advantage of the proposed main results.

  5. Continuous Variable Quantum Key Distribution Using Polarized Coherent States

    Vidiella-Barranco, A.; Borelli, L. F. M.

    We discuss a continuous variables method of quantum key distribution employing strongly polarized coherent states of light. The key encoding is performed using the variables known as Stokes parameters, rather than the field quadratures. Their quantum counterpart, the Stokes operators Ŝi (i=1,2,3), constitute a set of non-commuting operators, being the precision of simultaneous measurements of a pair of them limited by an uncertainty-like relation. Alice transmits a conveniently modulated two-mode coherent state, and Bob randomly measures one of the Stokes parameters of the incoming beam. After performing reconciliation and privacy amplification procedures, it is possible to distill a secret common key. We also consider a non-ideal situation, in which coherent states with thermal noise, instead of pure coherent states, are used for encoding.

  6. BAYESIAN DATA AUGMENTATION DOSE FINDING WITH CONTINUAL REASSESSMENT METHOD AND DELAYED TOXICITY

    Liu, Suyu; Yin, Guosheng; Yuan, Ying

    2014-01-01

    A major practical impediment when implementing adaptive dose-finding designs is that the toxicity outcome used by the decision rules may not be observed shortly after the initiation of the treatment. To address this issue, we propose the data augmentation continual re-assessment method (DA-CRM) for dose finding. By naturally treating the unobserved toxicities as missing data, we show that such missing data are nonignorable in the sense that the missingness depends on the unobserved outcomes. The Bayesian data augmentation approach is used to sample both the missing data and model parameters from their posterior full conditional distributions. We evaluate the performance of the DA-CRM through extensive simulation studies, and also compare it with other existing methods. The results show that the proposed design satisfactorily resolves the issues related to late-onset toxicities and possesses desirable operating characteristics: treating patients more safely, and also selecting the maximum tolerated dose with a higher probability. The new DA-CRM is illustrated with two phase I cancer clinical trials. PMID:24707327

  7. An analysis of global robust stability of uncertain cellular neural networks with discrete and distributed delays

    Park, Ju H.

    2007-01-01

    This paper considers the robust stability analysis of cellular neural networks with discrete and distributed delays. Based on the Lyapunov stability theory and linear matrix inequality (LMI) technique, a novel stability criterion guaranteeing the global robust convergence of the equilibrium point is derived. The criterion can be solved easily by various convex optimization algorithms. An example is given to illustrate the usefulness of our results

  8. Angular momentum distributions and delayed feeding in (d,3n) reaction to deformed nuclei

    Dracoulis, G.D.; Ferguson, S.M.; Newton, J.O.; Slocombe, M.G.

    1976-11-01

    The relative intensities of ground state rotational band transitions in 158 Dy, 164 Er, 168 Yb, 174 Hf and 180 W have been studied with particular emphasis on the identification of delayed feeding from high K isomers. The results are interpreted in terms of a simple formulation of the K-conservation model which is introduced to explain the discrepancy between the observed intensity distributions and those expected from the statistical model. (Author)

  9. 17 CFR 230.415 - Delayed or continuous offering and sale of securities.

    2010-04-01

    ... majority-owned subsidiary; or (xi) Shares of common stock which are to be offered and sold on a delayed or... an existing trading market for outstanding shares of the same class at other than a fixed price. (5... and sale of securities. 230.415 Section 230.415 Commodity and Securities Exchanges SECURITIES AND...

  10. The WS transform for the Kuramoto model with distributed amplitudes, phase lag and time delay

    Lohe, M. A.

    2017-12-01

    We apply the Watanabe-Strogatz (WS) transform to a generalized Kuramoto model with distributed parameters describing the amplitude of oscillation, phase lag, and time delay at each node of the system. The model has global coupling and identical frequencies, but allows for repulsive interactions at arbitrary nodes leading to conformist-contrarian phenomena together with variable amplitude and time-delay effects. We show how to determine the initial values of the WS system for any initial conditions for the Kuramoto system, and investigate the asymptotic behaviour of the WS variables. For the case of zero time delay the possible asymptotic configurations are determined by the sign of a single parameter μ which measures whether or not the attractive nodes dominate the repulsive nodes. If μ>0 the system completely synchronizes from general initial conditions, whereas if μ<0 one of two types of phase-locked synchronization occurs, depending on the initial values, while for μ=0 periodic solutions can occur. For the case of arbitrary non-uniform time delays we derive a stability condition for completely synchronized solutions.

  11. Multimoded rf delay line distribution system for the Next Linear Collider

    S. G. Tantawi

    2002-03-01

    Full Text Available The delay line distribution system is an alternative to conventional pulse compression, which enhances the peak power of rf sources while matching the long pulse of those sources to the shorter filling time of accelerator structures. We present an implementation of this scheme that combines pairs of parallel delay lines of the system into single lines. The power of several sources is combined into a single waveguide delay line using a multimode launcher. The output mode of the launcher is determined by the phase coding of the input signals. The combined power is extracted from the delay line using mode-selective extractors, each of which extracts a single mode. Hence, the phase coding of the sources controls the output port of the combined power. The power is then fed to the local accelerator structures. We present a detailed design of such a system, including several implementation methods for the launchers, extractors, and ancillary high power rf components. The system is designed so that it can handle the 600 MW peak power required by the Next Linear Collider design while maintaining high efficiency.

  12. Practical continuous-variable quantum key distribution without finite sampling bandwidth effects.

    Li, Huasheng; Wang, Chao; Huang, Peng; Huang, Duan; Wang, Tao; Zeng, Guihua

    2016-09-05

    In a practical continuous-variable quantum key distribution system, finite sampling bandwidth of the employed analog-to-digital converter at the receiver's side may lead to inaccurate results of pulse peak sampling. Then, errors in the parameters estimation resulted. Subsequently, the system performance decreases and security loopholes are exposed to eavesdroppers. In this paper, we propose a novel data acquisition scheme which consists of two parts, i.e., a dynamic delay adjusting module and a statistical power feedback-control algorithm. The proposed scheme may improve dramatically the data acquisition precision of pulse peak sampling and remove the finite sampling bandwidth effects. Moreover, the optimal peak sampling position of a pulse signal can be dynamically calibrated through monitoring the change of the statistical power of the sampled data in the proposed scheme. This helps to resist against some practical attacks, such as the well-known local oscillator calibration attack.

  13. Global stability results for a generalized Lotka-Volterra system with distributed delays. Applications to predator-prey and to epidemic systems.

    Beretta, E; Capasso, V; Rinaldi, F

    1988-01-01

    The paper contains an extension of the general ODE system proposed in previous papers by the same authors, to include distributed time delays in the interaction terms. The new system describes a large class of Lotka-Volterra like population models and epidemic models with continuous time delays. Sufficient conditions for the boundedness of solutions and for the global asymptotic stability of nontrivial equilibrium solutions are given. A detailed analysis of the epidemic system is given with respect to the conditions for global stability. For a relevant subclass of these systems an existence criterion for steady states is also given.

  14. Analysis of a Dynamical Cournot Duopoly Game with Distributed Time Delay

    SÎrghi Nicoleta

    2015-03-01

    Full Text Available The aim of the paper is to analyze the dynamic model of the Cournot duopoly game with bounded rationality associated to two firms. We consider the cost function of the first firm as nonlinear and for the second firm as linear. The players do not have a complete knowledge of the market and they follow a bounded rationality adjustment process based on the estimation of the marginal profit. Also, the distributed time delay is introduced, because the decisions at the current time depend on the average past decisions. The mathematical model is described by a distributed delay differential system with two nonlinear equations. The study for the local stability of the Nash equilibrium point is carried out in the case of two types of kernels: weak (exponential and Dirac. A change in local stability of the equilibrium point, from stable to unstable, implies a Hopf bifurcation. The delays are considered as bifurcation parameters. In some conditions of the parameters of the model, we have proved that a family of periodic solutions bifurcates from the equilibrium point when the bifurcation parameter passes through a critical value. Numerical simulations are performed to illustrate the effectiveness of our results. Finally, conclusions and future researches are provided.

  15. Cooperative Content Distribution over Wireless Networks for Energy and Delay Minimization

    Atat, Rachad

    2012-06-01

    Content distribution with mobile-to-mobile cooperation is studied. Data is sent to mobile terminals on a long range link then the terminals exchange the content using an appropriate short range wireless technology. Unicasting and multicasting are investigated, both on the long range and short range links. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form. Moreover, the schemes are applied in public safety vehicular networks, where Long Term Evolution (LTE) network is used for the long range link, while IEEE 802.11 p is considered for inter-vehicle collaboration on the short range links. Finally, relay-based multicasting is applied in high speed trains for energy and delay minimization. Results show that cooperative schemes outperform non-cooperative ones and other previous related work in terms of energy and delay savings. Furthermore, practical implementation aspects of the proposed methods are also discussed.

  16. Distributed Containment Control of Networked Fractional-Order Systems with Delay-Dependent Communications

    Xueliang Liu

    2012-01-01

    Full Text Available This paper is concerned with a containment problem of networked fractional-order system with multiple leaders under a fixed directed interaction graph. Based on the neighbor rule, a distributed protocol is proposed in delayed communication channels. By employing the algebraic graph theory, matrix theory, Nyquist stability theorem, and frequency domain method, it is analytically proved that the whole follower agents will flock to the convex hull which is formed by the leaders. Furthermore, a tight upper bound on the communication time-delay that can be tolerated in the dynamic network is obtained. As a special case, the interconnection topology under the undirected case is also discussed. Finally, some numerical examples with simulations are presented to demonstrate the effectiveness and correctness of the theoretical results.

  17. Global exponential stability of bidirectional associative memory neural networks with distributed delays

    Song, Qiankun; Cao, Jinde

    2007-05-01

    A bidirectional associative memory neural network model with distributed delays is considered. By constructing a new Lyapunov functional, employing the homeomorphism theory, M-matrix theory and the inequality (a[greater-or-equal, slanted]0,bk[greater-or-equal, slanted]0,qk>0 with , and r>1), a sufficient condition is obtained to ensure the existence, uniqueness and global exponential stability of the equilibrium point for the model. Moreover, the exponential converging velocity index is estimated, which depends on the delay kernel functions and the system parameters. The results generalize and improve the earlier publications, and remove the usual assumption that the activation functions are bounded . Two numerical examples are given to show the effectiveness of the obtained results.

  18. Distributed estimation and control for mobile sensor networks with coupling delays.

    Su, Housheng; Chen, Xuan; Chen, Michael Z Q; Wang, Lei

    2016-09-01

    This paper deals with the issue of distributed estimation and control for mobile sensor networks with coupling delays. Based on the Kalman-Consensus filter and the flocking algorithm, all mobile sensors move to a target to increase the quality of gathered data, and achieve consensus on the estimation values of the target in the presence of time-delay and noises. By applying an effective cascading Lyapunov method and matrix theory, stability analysis is carried out. Furthermore, a necessary condition for the convergence is presented via the boundary conditions of feedback coefficients. Some numerical examples are provided to validate the effectiveness of theoretical results. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Investigation of the delay time distribution of high power microwave surface flashover

    Foster, J.; Krompholz, H.; Neuber, A.

    2011-01-01

    Characterizing and modeling the statistics associated with the initiation of gas breakdown has proven to be difficult due to a variety of rather unexplored phenomena involved. Experimental conditions for high power microwave window breakdown for pressures on the order of 100 to several 100 torr are complex: there are little to no naturally occurring free electrons in the breakdown region. The initial electron generation rate, from an external source, for example, is time dependent and so is the charge carrier amplification in the increasing radio frequency (RF) field amplitude with a rise time of 50 ns, which can be on the same order as the breakdown delay time. The probability of reaching a critical electron density within a given time period is composed of the statistical waiting time for the appearance of initiating electrons in the high-field region and the build-up of an avalanche with an inherent statistical distribution of the electron number. High power microwave breakdown and its delay time is of critical importance, since it limits the transmission through necessary windows, especially for high power, high altitude, low pressure applications. The delay time distribution of pulsed high power microwave surface flashover has been examined for nitrogen and argon as test gases for pressures ranging from 60 to 400 torr, with and without external UV illumination. A model has been developed for predicting the discharge delay time for these conditions. The results provide indications that field induced electron generation, other than standard field emission, plays a dominant role, which might be valid for other gas discharge types as well.

  20. Continued use of an interactive computer game-based visual perception learning system in children with developmental delay.

    Lin, Hsien-Cheng; Chiu, Yu-Hsien; Chen, Yenming J; Wuang, Yee-Pay; Chen, Chiu-Ping; Wang, Chih-Chung; Huang, Chien-Ling; Wu, Tang-Meng; Ho, Wen-Hsien

    2017-11-01

    This study developed an interactive computer game-based visual perception learning system for special education children with developmental delay. To investigate whether perceived interactivity affects continued use of the system, this study developed a theoretical model of the process in which learners decide whether to continue using an interactive computer game-based visual perception learning system. The technology acceptance model, which considers perceived ease of use, perceived usefulness, and perceived playfulness, was extended by integrating perceived interaction (i.e., learner-instructor interaction and learner-system interaction) and then analyzing the effects of these perceptions on satisfaction and continued use. Data were collected from 150 participants (rehabilitation therapists, medical paraprofessionals, and parents of children with developmental delay) recruited from a single medical center in Taiwan. Structural equation modeling and partial-least-squares techniques were used to evaluate relationships within the model. The modeling results indicated that both perceived ease of use and perceived usefulness were positively associated with both learner-instructor interaction and learner-system interaction. However, perceived playfulness only had a positive association with learner-system interaction and not with learner-instructor interaction. Moreover, satisfaction was positively affected by perceived ease of use, perceived usefulness, and perceived playfulness. Thus, satisfaction positively affects continued use of the system. The data obtained by this study can be applied by researchers, designers of computer game-based learning systems, special education workers, and medical professionals. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Distributed Interplanetary Delay/Disruption Tolerant Network (DTN) Monitor and Control System

    Wang, Shin-Ywan

    2012-01-01

    The main purpose of Distributed interplanetary Delay Tolerant Network Monitor and Control System as a DTN system network management implementation in JPL is defined to provide methods and tools that can monitor the DTN operation status, detect and resolve DTN operation failures in some automated style while either space network or some heterogeneous network is infused with DTN capability. In this paper, "DTN Monitor and Control system in Deep Space Network (DSN)" exemplifies a case how DTN Monitor and Control system can be adapted into a space network as it is DTN enabled.

  2. Cluster synchronization of community network with distributed time delays via impulsive control

    Leng Hui; Wu Zhao-Yan

    2016-01-01

    Cluster synchronization is an important dynamical behavior in community networks and deserves further investigations. A community network with distributed time delays is investigated in this paper. For achieving cluster synchronization, an impulsive control scheme is introduced to design proper controllers and an adaptive strategy is adopted to make the impulsive controllers unified for different networks. Through taking advantage of the linear matrix inequality technique and constructing Lyapunov functions, some synchronization criteria with respect to the impulsive gains, instants, and system parameters without adaptive strategy are obtained and generalized to the adaptive case. Finally, numerical examples are presented to demonstrate the effectiveness of the theoretical results. (paper)

  3. Global exponential stability analysis on impulsive BAM neural networks with distributed delays

    Li, Yao-Tang; Yang, Chang-Bo

    2006-12-01

    Using M-matrix and topological degree tool, sufficient conditions are obtained for the existence, uniqueness and global exponential stability of the equilibrium point of bidirectional associative memory (BAM) neural networks with distributed delays and subjected to impulsive state displacements at fixed instants of time by constructing a suitable Lyapunov functional. The results remove the usual assumptions that the boundedness, monotonicity, and differentiability of the activation functions. It is shown that in some cases, the stability criteria can be easily checked. Finally, an illustrative example is given to show the effectiveness of the presented criteria.

  4. On delay adjustment for dynamic load balancing in distributed virtual environments.

    Deng, Yunhua; Lau, Rynson W H

    2012-04-01

    Distributed virtual environments (DVEs) are becoming very popular in recent years, due to the rapid growing of applications, such as massive multiplayer online games (MMOGs). As the number of concurrent users increases, scalability becomes one of the major challenges in designing an interactive DVE system. One solution to address this scalability problem is to adopt a multi-server architecture. While some methods focus on the quality of partitioning the load among the servers, others focus on the efficiency of the partitioning process itself. However, all these methods neglect the effect of network delay among the servers on the accuracy of the load balancing solutions. As we show in this paper, the change in the load of the servers due to network delay would affect the performance of the load balancing algorithm. In this work, we conduct a formal analysis of this problem and discuss two efficient delay adjustment schemes to address the problem. Our experimental results show that our proposed schemes can significantly improve the performance of the load balancing algorithm with neglectable computation overhead.

  5. Influence of distributed delays on the dynamics of a generalized immune system cancerous cells interactions model

    Piotrowska, M. J.; Bodnar, M.

    2018-01-01

    We present a generalisation of the mathematical models describing the interactions between the immune system and tumour cells which takes into account distributed time delays. For the analytical study we do not assume any particular form of the stimulus function describing the immune system reaction to presence of tumour cells but we only postulate its general properties. We analyse basic mathematical properties of the considered model such as existence and uniqueness of the solutions. Next, we discuss the existence of the stationary solutions and analytically investigate their stability depending on the forms of considered probability densities that is: Erlang, triangular and uniform probability densities separated or not from zero. Particular instability results are obtained for a general type of probability densities. Our results are compared with those for the model with discrete delays know from the literature. In addition, for each considered type of probability density, the model is fitted to the experimental data for the mice B-cell lymphoma showing mean square errors at the same comparable level. For estimated sets of parameters we discuss possibility of stabilisation of the tumour dormant steady state. Instability of this steady state results in uncontrolled tumour growth. In order to perform numerical simulation, following the idea of linear chain trick, we derive numerical procedures that allow us to solve systems with considered probability densities using standard algorithm for ordinary differential equations or differential equations with discrete delays.

  6. Distribution of intraarterially administered papaverine in endovascular treatment of delayed cerebral vasospasm

    Touho, Hajime; Fukuoka, Norihiko; Karasawa, Jun [Osaka Neurological Inst., Toyonaka (Japan)

    1997-02-01

    The distribution of selectively administered papaverine was determined in nine patients with delayed cerebral vasospasm in the territories of the anterior (ACA) and/or middle cerebral arteries (MCA) secondary to aneurysmal subarachnoid hemorrhage by simultaneous infusion with technetium-99m-hexamethyl-propyleneamine oxime ({sup 99m}Tc-HMPAO). Four of the nine patients had a ruptured anterior communicating artery aneurysm, four had an internal carotid artery aneurysm, and the remaining one had a MCA aneurysm. Trapping of anterior communicating artery was carried out in one case and clipping of aneurysms in other eight cases. Neurological deterioration with hemiparesis, paraparesis, and/or somnolence appeared between postsurgical days 8 and 13 due to delayed cerebral vasospasm in all patients. Intraarterial infusion of 40 mg of papaverine containing 37 MBq of {sup 99m}Tc-HMPAO was performed from the C{sub 1} segment in seven of the nine patients and from the C{sub 4} segment in the other two patients. {sup 99m}Tc-HMPAO was distributed in the territories of the ACA and MCA in the two patients who were treated with intraarterial infusion of papaverine from the C{sub 4} segment, but was distributed only to the territory of the ACA in four patients who were treated with intraarterial infusion of papaverine from the C{sub 1} segment at 1 ml/min. In contrast, {sup 99m}Tc-HMPAO was distributed in the territories of the ACA and MCA in the three patients who were treated with papaverine from the C{sub 1} segment at 2 ml/min, although most {sup 99m}Tc-HMPAO was distributed in the territory of the ACA. Vasospasm of the ACA can be treated by intraarterial infusion of papaverine from the C{sub 1} segment at 1 ml/min when selective catheterization to the ACA is difficult to perform. (author)

  7. The Study of Prompt and Delayed Muon Induced Fission. I.Total kinetic energies and mass distributions

    David, P; Hartfiel, J.; Janszen, H.; Petitjean, C.; Reist, H.W.; Polikanov, S.M.; Konijn, J.; Laat, de C.T.A.M.; Taal, A.; Krogulski, T.; Johansson, T.; Tibell, G.; Achard van Enschut, d' J.F.M.

    1987-01-01

    Mass yield and total kinetic energy release (TKE) distributions of fragments from prompt and delayed muon induced fission, separately, have been measured for the isotopes235U,238U,237Np and242Pu. The distributions from prompt muon induced fission are compared with the corresponding distributions

  8. A continuous time delay-difference type model (CTDDM) applied to stock assessment of the southern Atlantic albacore Thunnus alalunga

    LIAO Baochao; LIU Qun; ZHANG Kui; Abdul BASET; Aamir Mahmood MEMON; Khadim Hussain MEMON; HAN Yanan

    2016-01-01

    A continuous time delay-difference model (CTDDM) has been established that considers continuous time delays of biological processes.The southern Atlantic albacore (Thunnus alalunga) stock is the one of the commercially important tuna population in the marine world.The age structured production model (ASPM) and the surplus production model (SPM) have already been used to assess the albacore stock.However,the ASPM requires detailed biological information and the SPM lacks the biological realism.In this study,we focus on applying a CTDDM to the southern Atlantic albacore (T.alalunga) species,which provides an alternative method to assess this fishery.It is the first time that CTDDM has been provided for assessing the Atlantic albacore (T.alalunga) fishery.CTDDM obtained the 80% confidence interval of MSY (maximum sustainable yield) of(21510 t,23118 t).The catch in 2011 (24100 t) is higher than the MSY values and the relative fishing mortality ratio (F2011/FMSY) is higher than 1.0.The results of CTDDM were analyzed to verify the proposed methodology and provide reference information for the sustainable management of the southern Atlantic albacore stock.The CTDDM treats the recruitment,the growth,and the mortality rates as all varying continuously over time and fills gaps between ASPM and SPM in this stock assessment.

  9. D-DSC: Decoding Delay-based Distributed Source Coding for Internet of Sensing Things.

    Aktas, Metin; Kuscu, Murat; Dinc, Ergin; Akan, Ozgur B

    2018-01-01

    Spatial correlation between densely deployed sensor nodes in a wireless sensor network (WSN) can be exploited to reduce the power consumption through a proper source coding mechanism such as distributed source coding (DSC). In this paper, we propose the Decoding Delay-based Distributed Source Coding (D-DSC) to improve the energy efficiency of the classical DSC by employing the decoding delay concept which enables the use of the maximum correlated portion of sensor samples during the event estimation. In D-DSC, network is partitioned into clusters, where the clusterheads communicate their uncompressed samples carrying the side information, and the cluster members send their compressed samples. Sink performs joint decoding of the compressed and uncompressed samples and then reconstructs the event signal using the decoded sensor readings. Based on the observed degree of the correlation among sensor samples, the sink dynamically updates and broadcasts the varying compression rates back to the sensor nodes. Simulation results for the performance evaluation reveal that D-DSC can achieve reliable and energy-efficient event communication and estimation for practical signal detection/estimation applications having massive number of sensors towards the realization of Internet of Sensing Things (IoST).

  10. Exploiting geo-distributed clouds for a e-health monitoring system with minimum service delay and privacy preservation.

    Shen, Qinghua; Liang, Xiaohui; Shen, Xuemin; Lin, Xiaodong; Luo, Henry Y

    2014-03-01

    In this paper, we propose an e-health monitoring system with minimum service delay and privacy preservation by exploiting geo-distributed clouds. In the system, the resource allocation scheme enables the distributed cloud servers to cooperatively assign the servers to the requested users under the load balance condition. Thus, the service delay for users is minimized. In addition, a traffic-shaping algorithm is proposed. The traffic-shaping algorithm converts the user health data traffic to the nonhealth data traffic such that the capability of traffic analysis attacks is largely reduced. Through the numerical analysis, we show the efficiency of the proposed traffic-shaping algorithm in terms of service delay and privacy preservation. Furthermore, through the simulations, we demonstrate that the proposed resource allocation scheme significantly reduces the service delay compared to two other alternatives using jointly the short queue and distributed control law.

  11. Delayed vocal fold paralysis after continuous interscalene level brachial plexus block with catheter placement: a case report.

    Gollapalli, Lakshman; McKelvey, George; Wang, Hong

    2014-08-01

    We report an incident of delayed onset of true vocal fold paralysis with continuous interscalene brachial plexus block. A 51 year old woman underwent left shoulder manipulation and lysis of adhesions with fluoroscopy and general anesthesia. An interscalene brachial plexus block was performed and a catheter with a continuous infusion pump was placed for postoperative pain control. Following hospital discharge, approximately 8 hours after the initial catheter bolus the patient developed hoarseness, dysphagia, and dyspnea, secondary to left vocal fold palsy. The patient was admitted for observation and the catheter was discontinued with no intubation required. By the next morning, the patient's dysphagia and dyspnea had resolved and her hoarseness improved. Copyright © 2014. Published by Elsevier Inc.

  12. stress distribution in continuo ribution in continuous thin ribution

    eobe

    studied stresses in thin-walled box girder bridges but stress distribution walled box girder bridges .... the classical thin plate theory and trigonometric series. Lertsima et al. ..... remedied by applying spline finite strip method. Compared to other ...

  13. A rationale for continuing mass antibiotic distributions for trachoma

    House Jenafir

    2007-08-01

    Full Text Available Abstract Background The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. Methods We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Results Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Conclusion Local

  14. A rationale for continuing mass antibiotic distributions for trachoma.

    Ray, Kathryn J; Porco, Travis C; Hong, Kevin C; Lee, David C; Alemayehu, Wondu; Melese, Muluken; Lakew, Takele; Yi, Elizabeth; House, Jenafir; Chidambaram, Jaya D; Whitcher, John P; Gaynor, Bruce D; Lietman, Thomas M

    2007-08-07

    The World Health Organization recommends periodic mass antibiotic distributions to reduce the ocular strains of chlamydia that cause trachoma, the world's leading cause of infectious blindness. Their stated goal is to control infection, not to completely eliminate it. A single mass distribution can dramatically reduce the prevalence of infection. However, if infection is not eliminated in every individual in the community, it may gradually return back into the community, so often repeated treatments are necessary. Since public health groups are reluctant to distribute antibiotics indefinitely, we are still in need of a proven long-term rationale. Here we use mathematical models to demonstrate that repeated antibiotic distributions can eliminate infection in a reasonable time period. We fit parameters of a stochastic epidemiological transmission model to data collected before and 6 months after a mass antibiotic distribution in a region of Ethiopia that is one of the most severely affected areas in the world. We validate the model by comparing our predicted results to Ethiopian data which was collected biannually for two years past the initial mass antibiotic distribution. We use the model to simulate the effect of different treatment programs in terms of local elimination of infection. Simulations show that the average prevalence of infection across all villages progressively decreases after each treatment, as long as the frequency and coverage of antibiotics are high enough. Infection can be eliminated in more villages with each round of treatment. However, in the communities where infection is not eliminated, it returns to the same average level, forming the same stationary distribution. This phenomenon is also seen in subsequent epidemiological data from Ethiopia. Simulations suggest that a biannual treatment plan implemented for 5 years will lead to elimination in 95% of all villages. Local elimination from a community is theoretically possible, even in the

  15. Electrons with continuous energy distribution from energetic heavy ion collisions

    Berenyi, D.

    1984-01-01

    The properties and origin of continuous electron spectrum emitted in high energy heavy ion collisions are reviewed. The basic processes causing the characteristic regions of the continuous spectrum are described. The contribution of electrons ejected from the target and from the projectile are investigated in detail in the cases of light and heavy projectiles. The recently recognized mechanisms, electron-capture-to-continuum (ECC) and electron-loss-to-continuum (ELC), leading to a cusp in forward direction, and their theoretical interpretations are discussed. The importance of data from ion-atom collisions in the field of atomic physics and in applications are briefly summarized. (D.Gy)

  16. Global stability of stochastic high-order neural networks with discrete and distributed delays

    Wang Zidong; Fang Jianan; Liu Xiaohui

    2008-01-01

    High-order neural networks can be considered as an expansion of Hopfield neural networks, and have stronger approximation property, faster convergence rate, greater storage capacity, and higher fault tolerance than lower-order neural networks. In this paper, the global asymptotic stability analysis problem is considered for a class of stochastic high-order neural networks with discrete and distributed time-delays. Based on an Lyapunov-Krasovskii functional and the stochastic stability analysis theory, several sufficient conditions are derived, which guarantee the global asymptotic convergence of the equilibrium point in the mean square. It is shown that the stochastic high-order delayed neural networks under consideration are globally asymptotically stable in the mean square if two linear matrix inequalities (LMIs) are feasible, where the feasibility of LMIs can be readily checked by the Matlab LMI toolbox. It is also shown that the main results in this paper cover some recently published works. A numerical example is given to demonstrate the usefulness of the proposed global stability criteria

  17. Simultaneous classical communication and quantum key distribution using continuous variables*

    Qi, Bing

    2016-10-01

    Presently, classical optical communication systems employing strong laser pulses and quantum key distribution (QKD) systems working at single-photon levels are very different communication modalities. Dedicated devices are commonly required to implement QKD. In this paper, we propose a scheme which allows classical communication and QKD to be implemented simultaneously using the same communication infrastructure. More specially, we propose a coherent communication scheme where both the bits for classical communication and the Gaussian distributed random numbers for QKD are encoded on the same weak coherent pulse and decoded by the same coherent receiver. Simulation results based on practical system parameters show that both deterministic classical communication with a bit error rate of 10-9 and secure key distribution could be achieved over tens of kilometers of single-mode fibers. It is conceivable that in the future coherent optical communication network, QKD will be operated in the background of classical communication at a minimal cost.

  18. New Measures of Central Tendency and Variability of Continuous Distributions

    Fabián, Zdeněk

    2008-01-01

    Roč. 37, č. 2 (2008), s. 159-174 ISSN 0361-0926 R&D Projects: GA AV ČR 1ET400300513 Institutional research plan: CEZ:AV0Z10300504 Keywords : basic statistics * description of distributions * Johnson score * point estimates * score function Subject RIV: BA - General Mathematics Impact factor: 0.324, year: 2008

  19. Global Robust Stability of Switched Interval Neural Networks with Discrete and Distributed Time-Varying Delays of Neural Type

    Huaiqin Wu

    2012-01-01

    Full Text Available By combing the theories of the switched systems and the interval neural networks, the mathematics model of the switched interval neural networks with discrete and distributed time-varying delays of neural type is presented. A set of the interval parameter uncertainty neural networks with discrete and distributed time-varying delays of neural type are used as the individual subsystem, and an arbitrary switching rule is assumed to coordinate the switching between these networks. By applying the augmented Lyapunov-Krasovskii functional approach and linear matrix inequality (LMI techniques, a delay-dependent criterion is achieved to ensure to such switched interval neural networks to be globally asymptotically robustly stable in terms of LMIs. The unknown gain matrix is determined by solving this delay-dependent LMIs. Finally, an illustrative example is given to demonstrate the validity of the theoretical results.

  20. Delay-time distribution of core-collapse supernovae with late events resulting from binary interaction

    Zapartas, E.; de Mink, S. E.; Izzard, R. G.; Yoon, S.-C.; Badenes, C.; Götberg, Y.; de Koter, A.; Neijssel, C. J.; Renzo, M.; Schootemeijer, A.; Shrotriya, T. S.

    2017-05-01

    Most massive stars, the progenitors of core-collapse supernovae, are in close binary systems and may interact with their companion through mass transfer or merging. We undertake a population synthesis study to compute the delay-time distribution of core-collapse supernovae, that is, the supernova rate versus time following a starburst, taking into account binary interactions. We test the systematic robustness of our results by running various simulations to account for the uncertainties in our standard assumptions. We find that a significant fraction, %, of core-collapse supernovae are "late", that is, they occur 50-200 Myr after birth, when all massive single stars have already exploded. These late events originate predominantly from binary systems with at least one, or, in most cases, with both stars initially being of intermediate mass (4-8 M⊙). The main evolutionary channels that contribute often involve either the merging of the initially more massive primary star with its companion or the engulfment of the remaining core of the primary by the expanding secondary that has accreted mass at an earlier evolutionary stage. Also, the total number of core-collapse supernovae increases by % because of binarity for the same initial stellar mass. The high rate implies that we should have already observed such late core-collapse supernovae, but have not recognized them as such. We argue that φ Persei is a likely progenitor and that eccentric neutron star - white dwarf systems are likely descendants. Late events can help explain the discrepancy in the delay-time distributions derived from supernova remnants in the Magellanic Clouds and extragalactic type Ia events, lowering the contribution of prompt Ia events. We discuss ways to test these predictions and speculate on the implications for supernova feedback in simulations of galaxy evolution.

  1. Energy decay in a Timoshenko-type system for thermoelasticity of type III with distributed delay and past history

    Jianghao Hao

    2018-03-01

    Full Text Available In this work, we consider a one-dimensional Timoshenko system of thermoelasticity of type III with past history and distributive delay. It is known that an arbitrarily small delay may be the source of instability. We establish the well-posedness and the stability of the system for the cases of equal and nonequal speeds of wave propagation respectively. Our results show that the damping effect is strong enough to uniformly stabilize the system even in the presence of time delay under suitable conditions and improve the related results.

  2. Exponential stability for stochastic delayed recurrent neural networks with mixed time-varying delays and impulses: the continuous-time case

    Karthik Raja, U; Leelamani, A; Raja, R; Samidurai, R

    2013-01-01

    In this paper, the exponential stability for a class of stochastic neural networks with time-varying delays and impulsive effects is considered. By constructing suitable Lyapunov functionals and by using the linear matrix inequality optimization approach, we obtain sufficient delay-dependent criteria to ensure the exponential stability of stochastic neural networks with time-varying delays and impulses. Two numerical examples with simulation results are provided to illustrate the effectiveness of the obtained results over those already existing in the literature. (paper)

  3. Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

    Atat, Rachad

    2012-11-20

    Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

  4. Cooperative ad hoc networks for energy and delay efficient content distribution with fast channel variations

    Atat, Rachad; Yaacoub, Elias E.; Alouini, Mohamed-Slim; Abu-Dayya, Adnan A.

    2012-01-01

    Cooperative ad hoc networks for the efficient distribution of content of common interest are studied in the case of fast channel variations. Mobiles are grouped into cooperative clusters for the purpose of receiving the content with optimized energy efficiency. Data are sent to mobile terminals on a long range (LR) link, and then, the terminals exchange the content by using an appropriate short range wireless technology. When channel state information is available for the LR links, unicasting is used on the LR. When accurate channel state information is not available, threshold-based multicasting is implemented on the LR. Energy minimization is formulated as an optimization problem for each scenario, and the optimal solutions are determined in closed form in scenarios with fast channel variations. Results show significant energy savings in the proposed schemes compared with the noncooperative case and other previous related work. Furthermore, the energy minimizing solutions are shown to lead to reduced delay in the content distribution process. Practical implementation aspects of the proposed methods are also discussed. © 2012 John Wiley & Sons, Ltd.

  5. Delay-time distribution in the scattering of time-narrow wave packets (II)—quantum graphs

    Smilansky, Uzy; Schanz, Holger

    2018-02-01

    We apply the framework developed in the preceding paper in this series (Smilansky 2017 J. Phys. A: Math. Theor. 50 215301) to compute the time-delay distribution in the scattering of ultra short radio frequency pulses on complex networks of transmission lines which are modeled by metric (quantum) graphs. We consider wave packets which are centered at high wave number and comprise many energy levels. In the limit of pulses of very short duration we compute upper and lower bounds to the actual time-delay distribution of the radiation emerging from the network using a simplified problem where time is replaced by the discrete count of vertex-scattering events. The classical limit of the time-delay distribution is also discussed and we show that for finite networks it decays exponentially, with a decay constant which depends on the graph connectivity and the distribution of its edge lengths. We illustrate and apply our theory to a simple model graph where an algebraic decay of the quantum time-delay distribution is established.

  6. Vibration analysis of continuous maglev guideways with a moving distributed load model

    Teng, N G; Qiao, B P

    2008-01-01

    A model of moving distributed load with a constant speed is established for vertical vibration analysis of a continuous guideway in maglev transportation system. The guideway is considered as a continuous structural system and the action of maglev vehicles on guideways is considered as a moving distributed load. Vibration of the continuous guideways used in Shanghai maglev line is analyzed with this model. The factors that affect the vibration of the guideways, such as speeds, guideway's spans, frequency and damping, are discussed

  7. Critical capacity, travel time delays and travel time distribution of rapid mass transit systems

    Legara, Erika Fille; Monterola, Christopher; Lee, Kee Khoon; Hung, Gih Guang

    2014-07-01

    We set up a mechanistic agent-based model of a rapid mass transit system. Using empirical data from Singapore's unidentifiable smart fare card, we validate our model by reconstructing actual travel demand and duration of travel statistics. We subsequently use this model to investigate two phenomena that are known to significantly affect the dynamics within the RTS: (1) overloading in trains and (2) overcrowding in the RTS platform. We demonstrate that by varying the loading capacity of trains, a tipping point emerges at which an exponential increase in the duration of travel time delays is observed. We also probe the impact on the rail system dynamics of three types of passenger growth distribution across stations: (i) Dirac delta, (ii) uniform and (iii) geometric, which is reminiscent of the effect of land use on transport. Under the assumption of a fixed loading capacity, we demonstrate the dependence of a given origin-destination (OD) pair on the flow volume of commuters in station platforms.

  8. Positive periodic solutions of periodic neutral Lotka-Volterra system with distributed delays

    Li Yongkun

    2008-01-01

    By using a fixed point theorem of strict-set-contraction, some criteria are established for the existence of positive periodic solutions of the following periodic neutral Lotka-Volterra system with distributed delays (dx i (t))/(dt) =x i (t)[a i (t)-Σ j=1 n b ij (t)∫ -T ij 0 K ij (θ)x j ( t+θ)dθ-Σ j=1 n c ij (t)∫ -T ij 0 K ij (θ) x j ' (t+θ)dθ],i=1,2,...,n, where a i ,b ij ,c ij element of C(R,R + ) (i, j = 1, 2, ..., n) are ω-periodic functions, T ij ,T ij element of (0,∞) (i, j = 1, 2, ..., n) and K ij ,K ij element of (R,R + ) satisfying ∫ -T ij 0 K ij (θ)dθ=1,∫ -T ij 0 K ij (θ)dθ=1, i, j = 1, 2, ..., n

  9. Permanence of a predator-prey discrete system with Holling-IV functional response and distributed delays.

    Zhang, X; Wu, Z; Zhou, T

    2016-01-01

    A predator-prey discrete-time model with Holling-IV functional response and distributed delays is investigated in this paper. By using the comparison theorem of the difference equation and some analysis technique, some sufficient conditions are obtained for the permanence of the discrete predator-prey system. Two examples are given to illustrate the feasibility of the obtained result.

  10. On the Asymptotic Properties of Nonlinear Third-Order Neutral Delay Differential Equations with Distributed Deviating Arguments

    Youliang Fu

    2016-01-01

    Full Text Available This paper is concerned with the asymptotic properties of solutions to a third-order nonlinear neutral delay differential equation with distributed deviating arguments. Several new theorems are obtained which ensure that every solution to this equation either is oscillatory or tends to zero. Two illustrative examples are included.

  11. Adaptive Variance Scaling in Continuous Multi-Objective Estimation-of-Distribution Algorithms

    P.A.N. Bosman (Peter); D. Thierens (Dirk); D. Thierens (Dirk)

    2007-01-01

    htmlabstractRecent research into single-objective continuous Estimation-of-Distribution Algorithms (EDAs) has shown that when maximum-likelihood estimations are used for parametric distributions such as the normal distribution, the EDA can easily suffer from premature convergence. In this paper we

  12. Effects of the randomly distributed magnetic field on the phase diagrams of the Ising Nanowire II: Continuous distributions

    Akıncı, Ümit

    2012-01-01

    The effect of the random magnetic field distribution on the phase diagrams and ground state magnetizations of the Ising nanowire has been investigated with effective field theory with correlations. Gaussian distribution has been chosen as a random magnetic field distribution. The variation of the phase diagrams with that distribution parameters has been obtained and some interesting results have been found such as disappearance of the reentrant behavior and first order transitions which appear in the case of discrete distributions. Also for single and double Gaussian distributions, ground state magnetizations for different distribution parameters have been determined which can be regarded as separate partially ordered phases of the system. - Highlights: ► We give the phase diagrams of the Ising nanowire under the continuous randomly distributed magnetic field. ► Ground state magnetization values obtained. ► Different partially ordered phases observed.

  13. The probability distribution of the delay time of a wave packet in strong overlap of resonance levels

    Lyuboshitz, V.L.

    1982-01-01

    The time development of nuclear reactions at a large density of levels is investigated using the theory of overlapping resonances. The analytical expression for the function describing the time delay probability distribution of a wave packet is obtained in the framework of the model of n equi - valent channels. It is shown that a relative fluctuation of the time delay at the stage of the compound nucleus is snall. The possibility is discussed of increasing the duration of nuclear raactions with rising excitation energy

  14. Relation of immediate and delayed thallium-201 distribution to localization of iodine-125 antimyosin antibody in acute experimental myocardial infarction

    Khaw, B.A.; Strauss, H.W.; Pohost, G.M.; Fallon, J.T.; Katus, H.A.; Haber, E.

    1983-01-01

    Thallium-201 (TI-201) distribution in acute experimental myocardial infarction (MI) (n . 18) was compared with cardiac-specific antimyosin Fab (AM-Fab) uptake, a specific marker for myocardial necrosis. When antimyosin was injected 4 hours after ligation with TI-201 administered 23 hours 55 minutes later and measurement of myocardial distribution determined 5 minutes after intravenous administration of TI-201, (1) TI-201 distribution closely correlated with microsphere regional blood flow, and (2) an inverse exponential relation to iodine-125 (I-125) AM-Fab uptake was apparent. In another group of 4 animals, TI-201 and AM-Fab were administered intravenously 4 hours after MI, and 36 hours later myocardial distribution was measured. This delayed TI-201 distribution had a close inverse linear correlation with I-125 AM-Fab uptake. This inverse linear relation also was apparent in 28-hour-old MIs in dogs (n . 4) where collateral circulation had been established. TI-201 was administered intravenously at 27 hours after MI, and TI-201 distribution was determined 1 hour later. The present study demonstrated that whereas immediate TI-201 distribution is flow-limited, delayed TI-201 distribution is a marker of cell viability which, due to prolonged circulation time and redistribution, is not flow-limited

  15. Delayed neutrons as a probe of nuclear charge distribution in fission of heavy nuclei by neutrons

    Isaev, S G; Piksaikin, V M; Roshchenko, V A

    2001-01-01

    A method of the determination of cumulative yields of delayed neutron precursors is developed. This method is based on the iterative least-square procedure applied to delayed neutron decay curves measured after irradiation of sup 2 sup 3 sup 5 U sample by thermal neutrons. Obtained cumulative yields in turns were used for deriving the values of the most probable charge in low-energy fission of the above-mentioned nucleus.

  16. Delayed neutrons as a probe of nuclear charge distribution in fission of heavy nuclei by neutrons

    Isaev, S.G.; Piksaikin, V.M.; Kazakov, L.E.; Roshchenko, V.A.

    2002-01-01

    A method of the determination of cumulative yields of delayed neutron precursors is developed. This method is based on the iterative least-square procedure applied to delayed neutron decay curves measured after irradiation of 235 U sample by thermal neutrons. Obtained cumulative yields in turns were used for deriving the values of the most probable charge in low-energy fission of the above-mentioned nucleus. (author)

  17. Teaching Students to Request the Continuation of Routine Activities by Using Time Delay and Decreasing Physical Assistance in the Context of Chain Interruption.

    Gee, Kathleen; And Others

    1991-01-01

    Three students (ages 5-10) with profound intellectual, sensory, and physical disabilities were taught to activate a communication device to request the continuation of activities in which they were involved. The intervention consisted of a consistent response interval and increasing time delay paired with decreasing physical assistance in…

  18. Estimation of effective population size in continuously distributed populations: There goes the neighborhood

    M. C. Neel; K. McKelvey; N. Ryman; M. W. Lloyd; R. Short Bull; F. W. Allendorf; M. K. Schwartz; R. S. Waples

    2013-01-01

    Use of genetic methods to estimate effective population size (Ne) is rapidly increasing, but all approaches make simplifying assumptions unlikely to be met in real populations. In particular, all assume a single, unstructured population, and none has been evaluated for use with continuously distributed species. We simulated continuous populations with local mating...

  19. Vibration analysis of continuous maglev guideways with a moving distributed load model

    Teng, N G; Qiao, B P [Department of Civil Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240 (China)

    2008-02-15

    A model of moving distributed load with a constant speed is established for vertical vibration analysis of a continuous guideway in maglev transportation system. The guideway is considered as a continuous structural system and the action of maglev vehicles on guideways is considered as a moving distributed load. Vibration of the continuous guideways used in Shanghai maglev line is analyzed with this model. The factors that affect the vibration of the guideways, such as speeds, guideway's spans, frequency and damping, are discussed.

  20. A continuous variable quantum deterministic key distribution based on two-mode squeezed states

    Gong, Li-Hua; Song, Han-Chong; Liu, Ye; Zhou, Nan-Run; He, Chao-Sheng

    2014-01-01

    The distribution of deterministic keys is of significance in personal communications, but the existing continuous variable quantum key distribution protocols can only generate random keys. By exploiting the entanglement properties of two-mode squeezed states, a continuous variable quantum deterministic key distribution (CVQDKD) scheme is presented for handing over the pre-determined key to the intended receiver. The security of the CVQDKD scheme is analyzed in detail from the perspective of information theory. It shows that the scheme can securely and effectively transfer pre-determined keys under ideal conditions. The proposed scheme can resist both the entanglement and beam splitter attacks under a relatively high channel transmission efficiency. (paper)

  1. Stereo side information generation in low-delay distributed stereo video coding

    Salmistraro, Matteo; Forchhammer, Søren

    2012-01-01

    to create SI exploiting the inter-view spatial redundancy. A careful fusion of the two SI should be done in order to use the best part of each SI. In this work we study a Stereo Low-Delay scenario using only two views. Due to the delay constraint we use only past frames of the sequence we are decoding...... the two SIs, inspired by Multi-Hypothesis decoding. In this work the multiple hypotheses are used to fuse the SIs. Preliminary results show improvements up to 1 dB....

  2. Robust stability analysis for Markovian jumping interval neural networks with discrete and distributed time-varying delays

    Balasubramaniam, P.; Lakshmanan, S.; Manivannan, A.

    2012-01-01

    Highlights: ► Robust stability analysis for Markovian jumping interval neural networks is considered. ► Both linear fractional and interval uncertainties are considered. ► A new LKF is constructed with triple integral terms. ► MATLAB LMI control toolbox is used to validate theoretical results. ► Numerical examples are given to illustrate the effectiveness of the proposed method. - Abstract: This paper investigates robust stability analysis for Markovian jumping interval neural networks with discrete and distributed time-varying delays. The parameter uncertainties are assumed to be bounded in given compact sets. The delay is assumed to be time-varying and belong to a given interval, which means that the lower and upper bounds of interval time-varying delays are available. Based on the new Lyapunov–Krasovskii functional (LKF), some inequality techniques and stochastic stability theory, new delay-dependent stability criteria have been obtained in terms of linear matrix inequalities (LMIs). Finally, two numerical examples are given to illustrate the less conservative and effectiveness of our theoretical results.

  3. An extended continuous estimation of distribution algorithm for solving the permutation flow-shop scheduling problem

    Shao, Zhongshi; Pi, Dechang; Shao, Weishi

    2017-11-01

    This article proposes an extended continuous estimation of distribution algorithm (ECEDA) to solve the permutation flow-shop scheduling problem (PFSP). In ECEDA, to make a continuous estimation of distribution algorithm (EDA) suitable for the PFSP, the largest order value rule is applied to convert continuous vectors to discrete job permutations. A probabilistic model based on a mixed Gaussian and Cauchy distribution is built to maintain the exploration ability of the EDA. Two effective local search methods, i.e. revolver-based variable neighbourhood search and Hénon chaotic-based local search, are designed and incorporated into the EDA to enhance the local exploitation. The parameters of the proposed ECEDA are calibrated by means of a design of experiments approach. Simulation results and comparisons based on some benchmark instances show the efficiency of the proposed algorithm for solving the PFSP.

  4. Understanding the Effect of Audio Communication Delay on Distributed Team Interaction

    2013-06-01

    means for members to socialize and learn about each other, engenders development cooperative relationships, and lays a foundation for future interaction...length will result in increases in task completion time and mental workload. 3. Audiovisual technology will moderate the effect of communication...than audio alone. 4. Audiovisual technology will moderate the effect of communication delays such that task completion time and mental workload will

  5. Elimination of mode coupling in multimode continuous-variable key distribution

    Filip, Radim; Mista, Ladislav; Marek, Petr

    2005-01-01

    A multimode channel can be utilized to substantially increase the capacity of quantum continuous-variable key distribution. Beyond losses in the channel, an uncontrollable coupling between the modes of the channel typically degrades the capacity of multimode channels. For the key distribution protocol with simultaneous measurement of both complementary quadratures we propose a feasible method to eliminate any undesirable mode coupling by only the receiver's appropriate measurement and data manipulation. It can be used to substantially increase the capacity of the channel, which has an important application in practical continuous-variable quantum cryptography

  6. Thermoluminescence glow-curve deconvolution functions for mixed order of kinetics and continuous trap distribution

    Kitis, G.; Gomez-Ros, J.M.

    2000-01-01

    New glow-curve deconvolution functions are proposed for mixed order of kinetics and for continuous-trap distribution. The only free parameters of the presented glow-curve deconvolution functions are the maximum peak intensity (I m ) and the maximum peak temperature (T m ), which can be estimated experimentally together with the activation energy (E). The other free parameter is the activation energy range (ΔE) for the case of the continuous-trap distribution or a constant α for the case of mixed-order kinetics

  7. Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

    Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

    2017-05-24

    In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

  8. Stability analysis of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time varying delays

    Ali, M. Syed

    2014-01-01

    In this paper, the global asymptotic stability problem of Markovian jumping stochastic Cohen—Grossberg neural networks with discrete and distributed time-varying delays (MJSCGNNs) is considered. A novel LMI-based stability criterion is obtained by constructing a new Lyapunov functional to guarantee the asymptotic stability of MJSCGNNs. Our results can be easily verified and they are also less restrictive than previously known criteria and can be applied to Cohen—Grossberg neural networks, recurrent neural networks, and cellular neural networks. Finally, the proposed stability conditions are demonstrated with numerical examples

  9. New results on global exponential dissipativity analysis of memristive inertial neural networks with distributed time-varying delays.

    Zhang, Guodong; Zeng, Zhigang; Hu, Junhao

    2018-01-01

    This paper is concerned with the global exponential dissipativity of memristive inertial neural networks with discrete and distributed time-varying delays. By constructing appropriate Lyapunov-Krasovskii functionals, some new sufficient conditions ensuring global exponential dissipativity of memristive inertial neural networks are derived. Moreover, the globally exponential attractive sets and positive invariant sets are also presented here. In addition, the new proposed results here complement and extend the earlier publications on conventional or memristive neural network dynamical systems. Finally, numerical simulations are given to illustrate the effectiveness of obtained results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Robust output observer-based control of neutral uncertain systems with discrete and distributed time delays: LMI optimization approach

    Chen, J.-D.

    2007-01-01

    In this paper, the robust control problem of output dynamic observer-based control for a class of uncertain neutral systems with discrete and distributed time delays is considered. Linear matrix inequality (LMI) optimization approach is used to design the new output dynamic observer-based controls. Three classes of observer-based controls are proposed and the maximal perturbed bound is given. Based on the results of this paper, the constraint of matrix equality is not necessary for designing the observer-based controls. Finally, a numerical example is given to illustrate the usefulness of the proposed method

  11. Evaluating sample allocation and effort in detecting population differentiation for discrete and continuously distributed individuals

    Erin L. Landguth; Michael K. Schwartz

    2014-01-01

    One of the most pressing issues in spatial genetics concerns sampling. Traditionally, substructure and gene flow are estimated for individuals sampled within discrete populations. Because many species may be continuously distributed across a landscape without discrete boundaries, understanding sampling issues becomes paramount. Given large-scale, geographically broad...

  12. Delayed radiation injury of gut-exposed and gut-shielded mice. I. The decrement in resistance to continuous gamma-ray stress

    Spalding, J.F.; Archuleta, R.F.; London, J.E.; Prine, J.R.

    1977-02-01

    Two mouse strains (RF/J and C57B1/6J) were exposed to x-ray doses totaling 400, 800, or 1200 rad. Total doses were given in 200-rad fractions at 7-day intervals to the whole body, gut only, or gut shielded. Animals treated as above (conditioned) were divided into 2 groups to form a two-part investigation. X-ray-conditioned and control mice were subjected to a continuous gamma-ray stress (challenge exposure) 28 days after the last x-ray dose. Delayed injury was measured as a reduction in mean after-survival (MAS) time and was observed in whole-body, gut-conditioned, and gut-shielded groups. The cause of death was attributed to hemopoietic hypoplasia in all groups. MAS reduction in all conditioned groups in both strains was linear with dose within the dose range used. Delayed injury per volume dose (measured as a reduction in MAS) was independent of the tissue initially conditioned with an acute dose of x rays. Thus, delayed injury per unit weight of gut tissue exposed was equal to that of either whole-body or gut-shielded radiation injury. Comparative weight loss observations during the continuous gamma-ray challenge exposure revealed a decrement in metabolic processes associated with body weight maintenance. This decrement was seen in all x-ray-conditioned groups

  13. POSITIVE SOLUTIONS TO TWO TYPES OF NEUTRAL DIFFERENTIAL EQUATIONS WITH DISTRIBUTED DELAY

    2012-01-01

    In this paper, we study two types of neutral functional differential equations with finite or unbounded distributed deviating arguments. By Banach contraction princi-ple, we obtain some sufficient conditions for the existence of positive solutions to such equations.

  14. Analysis of discrete and continuous distributions of ventilatory time constants from dynamic computed tomography

    Doebrich, Marcus; Markstaller, Klaus; Karmrodt, Jens; Kauczor, Hans-Ulrich; Eberle, Balthasar; Weiler, Norbert; Thelen, Manfred; Schreiber, Wolfgang G

    2005-01-01

    In this study, an algorithm was developed to measure the distribution of pulmonary time constants (TCs) from dynamic computed tomography (CT) data sets during a sudden airway pressure step up. Simulations with synthetic data were performed to test the methodology as well as the influence of experimental noise. Furthermore the algorithm was applied to in vivo data. In five pigs sudden changes in airway pressure were imposed during dynamic CT acquisition in healthy lungs and in a saline lavage ARDS model. The fractional gas content in the imaged slice (FGC) was calculated by density measurements for each CT image. Temporal variations of the FGC were analysed assuming a model with a continuous distribution of exponentially decaying time constants. The simulations proved the feasibility of the method. The influence of experimental noise could be well evaluated. Analysis of the in vivo data showed that in healthy lungs ventilation processes can be more likely characterized by discrete TCs whereas in ARDS lungs continuous distributions of TCs are observed. The temporal behaviour of lung inflation and deflation can be characterized objectively using the described new methodology. This study indicates that continuous distributions of TCs reflect lung ventilation mechanics more accurately compared to discrete TCs

  15. Hierarchical Delay-Dependent Distributed Coordinated Control for DC Ring-Bus Microgrids

    Dou, Chunxia; Yue, Dong; Zhang, Zhanqiang

    2017-01-01

    In this paper, a hierarchical distributed coordinated control method is proposed based on the multi-agent system for dc ring-bus microgrids to improve the bus voltage performance. First, a two-level multi-agent system is built, where each first-level unit control agent is associated with a distri......In this paper, a hierarchical distributed coordinated control method is proposed based on the multi-agent system for dc ring-bus microgrids to improve the bus voltage performance. First, a two-level multi-agent system is built, where each first-level unit control agent is associated...

  16. Saddlepoint approximation to the distribution of the total distance of the continuous time random walk

    Gatto, Riccardo

    2017-12-01

    This article considers the random walk over Rp, with p ≥ 2, where a given particle starts at the origin and moves stepwise with uniformly distributed step directions and step lengths following a common distribution. Step directions and step lengths are independent. The case where the number of steps of the particle is fixed and the more general case where it follows an independent continuous time inhomogeneous counting process are considered. Saddlepoint approximations to the distribution of the distance from the position of the particle to the origin are provided. Despite the p-dimensional nature of the random walk, the computations of the saddlepoint approximations are one-dimensional and thus simple. Explicit formulae are derived with dimension p = 3: for uniformly and exponentially distributed step lengths, for fixed and for Poisson distributed number of steps. In these situations, the high accuracy of the saddlepoint approximations is illustrated by numerical comparisons with Monte Carlo simulation. Contribution to the "Topical Issue: Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  17. Convergence of carbon dioxide emissions in Chinese cities: A continuous dynamic distribution approach

    Wu, Jianxin; Wu, Yanrui; Guo, Xiumei; Cheong, Tsun Se

    2016-01-01

    This paper investigates the spatial dynamics of per capita carbon dioxide (CO_2) emissions in China. The analyses are conducted by employing a continuous dynamic distribution approach and panel data of 286 cities at the prefecture and above-prefecture level. The results show that per capita CO_2 emissions tend to converge during the sample period of 2002–2011. However, multimodality is found in the ergodic distribution of the full sample. It is also found that there is more persistence in cities with low per capita CO_2 emissions, and more mobility in cities with high per capita CO_2 emissions. The analyses also show that the dynamics of per capita CO_2 emissions are significantly different among various geographical, income and environmental policy groups. The conditional distribution analyses indicate that multimodality cannot be explained independently by any one of the two factors, namely geographical location or income level. The findings in this study may have important policy implications for CO_2 abatement in China. - Highlights: •Spatial dynamics of per capita carbon dioxide (CO_2) emissions in 286 Chinese cities. •A continuous dynamic distribution approach and panel data. •Multimodality is found in the ergodic distribution of the full sample. •Significantly different dynamics among various city groups.

  18. Noiseless Linear Amplifiers in Entanglement-Based Continuous-Variable Quantum Key Distribution

    Yichen Zhang

    2015-06-01

    Full Text Available We propose a method to improve the performance of two entanglement-based continuous-variable quantum key distribution protocols using noiseless linear amplifiers. The two entanglement-based schemes consist of an entanglement distribution protocol with an untrusted source and an entanglement swapping protocol with an untrusted relay. Simulation results show that the noiseless linear amplifiers can improve the performance of these two protocols, in terms of maximal transmission distances, when we consider small amounts of entanglement, as typical in realistic setups.

  19. Effect of feedback on delaying deterioration in quality of compressions during 2 minutes of continuous chest compressions

    Lyngeraa, Tobias S; Hjortrup, Peter Buhl; Wulff, Nille B

    2012-01-01

    delays deterioration of quality of compressions. METHODS: Participants attending a national one-day conference on cardiac arrest and CPR in Denmark were randomized to perform single-rescuer BLS with (n = 26) or without verbal and visual feedback (n = 28) on a manikin using a ZOLL AED plus. Data were...... analyzed using Rescuenet Code Review. Blinding of participants was not possible, but allocation concealment was performed. Primary outcome was the proportion of delivered compressions within target depth compared over a 2-minute period within the groups and between the groups. Secondary outcome...... was the proportion of delivered compressions within target rate compared over a 2-minute period within the groups and between the groups. Performance variables for 30-second intervals were analyzed and compared. RESULTS: 24 (92%) and 23 (82%) had CPR experience in the group with and without feedback respectively. 14...

  20. Distributed continuous media streaming - Using redundant hierarchy (RED-Hi) servers

    Shah, Mohammad Ahmed

    2014-01-01

    ABSTRACT: The first part of this thesis provides a survey of continuous media serves, including discussions on streaming protocols, models and techniques. In the second part, a novel distributed media streaming system is introduced. In order to manage the traffic in a fault tolerant and effective manner a hierarchical topology, so called redundant hierarchy (RED-Hi) is used. The proposed system works in three steps, namely, object location, path reservation and object delivery. Simulations ar...

  1. Transforming between discrete and continuous angle distribution models: application to protein χ1 torsions

    Schmidt, Jürgen M.

    2012-01-01

    Two commonly employed angular-mobility models for describing amino-acid side-chain χ 1 torsion conformation, the staggered-rotamer jump and the normal probability density, are discussed and performance differences in applications to scalar-coupling data interpretation highlighted. Both models differ in their distinct statistical concepts, representing discrete and continuous angle distributions, respectively. Circular statistics, introduced for describing torsion-angle distributions by using a universal circular order parameter central to all models, suggest another distribution of the continuous class, here referred to as the elliptic model. Characteristic of the elliptic model is that order parameter and circular variance form complementary moduli. Transformations between the parameter sets that describe the probability density functions underlying the different models are provided. Numerical aspects of parameter optimization are considered. The issues are typified by using a set of χ 1 related 3 J coupling constants available for FK506-binding protein. The discrete staggered-rotamer model is found generally to produce lower order parameters, implying elevated rotatory variability in the amino-acid side chains, whereas continuous models tend to give higher order parameters that suggest comparatively less variation in angle conformations. The differences perceived regarding angular mobility are attributed to conceptually different features inherent to the models.

  2. Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach.

    Un, M Kerem; Kaghazchi, Hamed

    2018-01-01

    When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem. This is usually achieved by dividing the fibers into a finite number of diameter groups and solve a corresponding linear system to optimize FDD. However, number of fibers in a nerve can be measured sometimes in thousands and it is possible to assume a continuous distribution for the fiber diameters which leads to a gradient optimization problem. In this paper, we have evaluated this continuous approach to the solution of the inverse problem. We have utilized an analytical function for SFAP and an assumed a polynomial form for FDD. The inverse problem involves the optimization of polynomial coefficients to obtain the best estimate for the FDD. We have observed that an eighth order polynomial for FDD can capture both unimodal and bimodal fiber distributions present in vivo, even in case of noisy CAP data. The assumed FDD distribution regularizes the ill-conditioned inverse problem and produces good results.

  3. Continuous-variable quantum key distribution in uniform fast-fading channels

    Papanastasiou, Panagiotis; Weedbrook, Christian; Pirandola, Stefano

    2018-03-01

    We investigate the performance of several continuous-variable quantum key distribution protocols in the presence of uniform fading channels. These are lossy channels whose transmissivity changes according to a uniform probability distribution. We assume the worst-case scenario where an eavesdropper induces a fast-fading process, where she chooses the instantaneous transmissivity while the remote parties may only detect the mean statistical effect. We analyze coherent-state protocols in various configurations, including the one-way switching protocol in reverse reconciliation, the measurement-device-independent protocol in the symmetric configuration, and its extension to a three-party network. We show that, regardless of the advantage given to the eavesdropper (control of the fading), these protocols can still achieve high rates under realistic attacks, within reasonable values for the variance of the probability distribution associated with the fading process.

  4. An Event-Based Approach to Distributed Diagnosis of Continuous Systems

    Daigle, Matthew; Roychoudhurry, Indranil; Biswas, Gautam; Koutsoukos, Xenofon

    2010-01-01

    Distributed fault diagnosis solutions are becoming necessary due to the complexity of modern engineering systems, and the advent of smart sensors and computing elements. This paper presents a novel event-based approach for distributed diagnosis of abrupt parametric faults in continuous systems, based on a qualitative abstraction of measurement deviations from the nominal behavior. We systematically derive dynamic fault signatures expressed as event-based fault models. We develop a distributed diagnoser design algorithm that uses these models for designing local event-based diagnosers based on global diagnosability analysis. The local diagnosers each generate globally correct diagnosis results locally, without a centralized coordinator, and by communicating a minimal number of measurements between themselves. The proposed approach is applied to a multi-tank system, and results demonstrate a marked improvement in scalability compared to a centralized approach.

  5. AN ACCURATE MODELING OF DELAY AND SLEW METRICS FOR ON-CHIP VLSI RC INTERCONNECTS FOR RAMP INPUTS USING BURR’S DISTRIBUTION FUNCTION

    Rajib Kar

    2010-09-01

    Full Text Available This work presents an accurate and efficient model to compute the delay and slew metric of on-chip interconnect of high speed CMOS circuits foe ramp input. Our metric assumption is based on the Burr’s Distribution function. The Burr’s distribution is used to characterize the normalized homogeneous portion of the step response. We used the PERI (Probability distribution function Extension for Ramp Inputs technique that extends delay metrics and slew metric for step inputs to the more general and realistic non-step inputs. The accuracy of our models is justified with the results compared with that of SPICE simulations.

  6. Finite Time Fault Tolerant Control for Robot Manipulators Using Time Delay Estimation and Continuous Nonsingular Fast Terminal Sliding Mode Control.

    Van, Mien; Ge, Shuzhi Sam; Ren, Hongliang

    2016-04-28

    In this paper, a novel finite time fault tolerant control (FTC) is proposed for uncertain robot manipulators with actuator faults. First, a finite time passive FTC (PFTC) based on a robust nonsingular fast terminal sliding mode control (NFTSMC) is investigated. Be analyzed for addressing the disadvantages of the PFTC, an AFTC are then investigated by combining NFTSMC with a simple fault diagnosis scheme. In this scheme, an online fault estimation algorithm based on time delay estimation (TDE) is proposed to approximate actuator faults. The estimated fault information is used to detect, isolate, and accommodate the effect of the faults in the system. Then, a robust AFTC law is established by combining the obtained fault information and a robust NFTSMC. Finally, a high-order sliding mode (HOSM) control based on super-twisting algorithm is employed to eliminate the chattering. In comparison to the PFTC and other state-of-the-art approaches, the proposed AFTC scheme possess several advantages such as high precision, strong robustness, no singularity, less chattering, and fast finite-time convergence due to the combined NFTSMC and HOSM control, and requires no prior knowledge of the fault due to TDE-based fault estimation. Finally, simulation results are obtained to verify the effectiveness of the proposed strategy.

  7. Global exponential stability and periodicity of reaction-diffusion recurrent neural networks with distributed delays and Dirichlet boundary conditions

    Lu Junguo; Lu Linji

    2009-01-01

    In this paper, global exponential stability and periodicity of a class of reaction-diffusion recurrent neural networks with distributed delays and Dirichlet boundary conditions are studied by constructing suitable Lyapunov functionals and utilizing some inequality techniques. We first prove global exponential convergence to 0 of the difference between any two solutions of the original neural networks, the existence and uniqueness of equilibrium is the direct results of this procedure. This approach is different from the usually used one where the existence, uniqueness of equilibrium and stability are proved in two separate steps. Secondly, we prove periodicity. Sufficient conditions ensuring the existence, uniqueness, and global exponential stability of the equilibrium and periodic solution are given. These conditions are easy to verify and our results play an important role in the design and application of globally exponentially stable neural circuits and periodic oscillatory neural circuits.

  8. Delay-sensitive content distribution via peer-to-peer collaboration in public safety vehicular ad-hoc networks

    Atat, Rachad; Yaacoub, Elias E.; Alouini, Mohamed-Slim; Filali, Fethi; Abu-Dayya, Adnan A.

    2014-01-01

    Delay-sensitive content distribution with peer-to-peer (P2P) cooperation in public safety vehicular networks is investigated. Two cooperative schemes are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range (LR) communications with the base station (BS) and IEEE 802.11p is considered for inter-vehicle collaboration on the short range (SR). The first scheme is shown to outperform non-cooperative unicasting and multicasting, while the second scheme outperforms non-cooperative unicasting beyond a specific number of cooperating vehicles, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2014 Elsevier B.V. All rights reserved.

  9. Delay-sensitive content distribution via peer-to-peer collaboration in public safety vehicular ad-hoc networks

    Atat, Rachad

    2014-05-01

    Delay-sensitive content distribution with peer-to-peer (P2P) cooperation in public safety vehicular networks is investigated. Two cooperative schemes are presented and analyzed. The first scheme is based on unicasting from the base station, whereas the second is based on threshold based multicasting. Long Term Evolution (LTE) is used for long range (LR) communications with the base station (BS) and IEEE 802.11p is considered for inter-vehicle collaboration on the short range (SR). The first scheme is shown to outperform non-cooperative unicasting and multicasting, while the second scheme outperforms non-cooperative unicasting beyond a specific number of cooperating vehicles, when the appropriate 802.11p power class is used. The first scheme achieves the best performance among the compared methods, and a practical approximation of that scheme is shown to be close to optimal performance. © 2014 Elsevier B.V. All rights reserved.

  10. Continuous tissue glucose monitoring correlates with measurement of intermittent capillary glucose in patients with distributive shock.

    Ballesteros, D; Martínez, Ó; Blancas Gómez-Casero, R; Martín Parra, C; López Matamala, B; Estébanez, B; Chana, M

    2015-10-01

    Intermittent glycemic measurements in patients admitted to the intensive care unit (ICU) can result in episodes of severe hypoglycemia or in a poor control of glycemia range. We designed a study to assess accuracy and reliability of continuous monitoring of tissue glucose for patients with distributive shock. Consecutive patients admitted to the ICU with a diagnosis of distributive shock and the need of insulin infusion for glycemic control were included in the study. These patients were implanted a Continuous Glucose Control Monitoring System (CGMS) with the sensor inserted subcutaneously into the abdominal wall. CGMS values were recorded every 5min. Capillary glucose (CG) was monitored for adjusting insulin perfusion according to the ICU protocol. Correlation between both methods was assessed. A total of 11,673 CGMS and 348 CG values were recorded. In five patients, CGMS failed to detect tissue glucose. A glucose value <3.33mmol/l (<60mg/dl) was observed in 3.6% of CGMS and in 0.29% CG values. 295 pairs of measurements were included in the statistical analysis for correlation assessment. The intraclass correlation coefficient was 0.706. The Pearson correlation coefficient was 0.71 (p<0.0001, 95% CI 0.65-0.76). The mean of differences between both measurement methods was 0.22mmol/l (3.98mg/dl) (95% CI 0.66-7.31). When the Continuous Glucose Control Monitoring System (CGMS) is able to obtain data (75% of the patients), there is correlation between the values obtained by this method and capillary blood glucose in patients with distributive shock. CGMS can detect more episodes of glycemic excursions outside the normal range than intermittent capillary glucose monitoring. Variables that may impair glucose metabolism and peripheral soft tissues perfusion could impair CGMS measurements. Copyright © 2014 Elsevier España, S.L.U. and SEMICYUC. All rights reserved.

  11. Security proof of continuous-variable quantum key distribution using three coherent states

    Brádler, Kamil; Weedbrook, Christian

    2018-02-01

    We introduce a ternary quantum key distribution (QKD) protocol and asymptotic security proof based on three coherent states and homodyne detection. Previous work had considered the binary case of two coherent states and here we nontrivially extend this to three. Our motivation is to leverage the practical benefits of both discrete and continuous (Gaussian) encoding schemes creating a best-of-both-worlds approach; namely, the postprocessing of discrete encodings and the hardware benefits of continuous ones. We present a thorough and detailed security proof in the limit of infinite signal states which allows us to lower bound the secret key rate. We calculate this is in the context of collective eavesdropping attacks and reverse reconciliation postprocessing. Finally, we compare the ternary coherent state protocol to other well-known QKD schemes (and fundamental repeaterless limits) in terms of secret key rates and loss.

  12. Field test of a continuous-variable quantum key distribution prototype

    Fossier, S; Debuisschert, T; Diamanti, E; Villing, A; Tualle-Brouri, R; Grangier, P

    2009-01-01

    We have designed and realized a prototype that implements a continuous-variable quantum key distribution (QKD) protocol based on coherent states and reverse reconciliation. The system uses time and polarization multiplexing for optimal transmission and detection of the signal and phase reference, and employs sophisticated error-correction codes for reconciliation. The security of the system is guaranteed against general coherent eavesdropping attacks. The performance of the prototype was tested over preinstalled optical fibres as part of a quantum cryptography network combining different QKD technologies. The stable and automatic operation of the prototype over 57 h yielded an average secret key distribution rate of 8 kbit s -1 over a 3 dB loss optical fibre, including the key extraction process and all quantum and classical communication. This system is therefore ideal for securing communications in metropolitan size networks with high-speed requirements.

  13. Integration of quantum key distribution and private classical communication through continuous variable

    Wang, Tianyi; Gong, Feng; Lu, Anjiang; Zhang, Damin; Zhang, Zhengping

    2017-12-01

    In this paper, we propose a scheme that integrates quantum key distribution and private classical communication via continuous variables. The integrated scheme employs both quadratures of a weak coherent state, with encrypted bits encoded on the signs and Gaussian random numbers encoded on the values of the quadratures. The integration enables quantum and classical data to share the same physical and logical channel. Simulation results based on practical system parameters demonstrate that both classical communication and quantum communication can be implemented over distance of tens of kilometers, thus providing a potential solution for simultaneous transmission of quantum communication and classical communication.

  14. Security bound of continuous-variable quantum key distribution with noisy coherent states and channel

    Shen Yong; Yang Jian; Guo Hong

    2009-01-01

    Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.

  15. Robust shot-noise measurement for continuous-variable quantum key distribution

    Kunz-Jacques, Sébastien; Jouguet, Paul

    2015-02-01

    We study a practical method to measure the shot noise in real time in continuous-variable quantum key distribution systems. The amount of secret key that can be extracted from the raw statistics depends strongly on this quantity since it affects in particular the computation of the excess noise (i.e., noise in excess of the shot noise) added by an eavesdropper on the quantum channel. Some powerful quantum hacking attacks relying on faking the estimated value of the shot noise to hide an intercept and resend strategy were proposed. Here, we provide experimental evidence that our method can defeat the saturation attack and the wavelength attack.

  16. Continuously distributed magnetization profile for millimeter-scale elastomeric undulatory swimming

    Diller, Eric; Zhuang, Jiang; Zhan Lum, Guo; Edwards, Matthew R.; Sitti, Metin

    2014-04-01

    We have developed a millimeter-scale magnetically driven swimming robot for untethered motion at mid to low Reynolds numbers. The robot is propelled by continuous undulatory deformation, which is enabled by the distributed magnetization profile of a flexible sheet. We demonstrate control of a prototype device and measure deformation and speed as a function of magnetic field strength and frequency. Experimental results are compared with simple magnetoelastic and fluid propulsion models. The presented mechanism provides an efficient remote actuation method at the millimeter scale that may be suitable for further scaling down in size for micro-robotics applications in biotechnology and healthcare.

  17. Continuous time modelling of dynamical spatial lattice data observed at sparsely distributed times

    Rasmussen, Jakob Gulddahl; Møller, Jesper

    2007-01-01

    Summary. We consider statistical and computational aspects of simulation-based Bayesian inference for a spatial-temporal model based on a multivariate point process which is only observed at sparsely distributed times. The point processes are indexed by the sites of a spatial lattice......, and they exhibit spatial interaction. For specificity we consider a particular dynamical spatial lattice data set which has previously been analysed by a discrete time model involving unknown normalizing constants. We discuss the advantages and disadvantages of using continuous time processes compared...... with discrete time processes in the setting of the present paper as well as other spatial-temporal situations....

  18. On continuous lifetime distributions with polynomial failure rate with an application in reliability

    Csenki, Attila

    2011-01-01

    It is shown that the Laplace transform of a continuous lifetime random variable with a polynomial failure rate function satisfies a certain differential equation. This generates a set of differential equations which can be used to express the polynomial coefficients in terms of the derivatives of the Laplace transform at the origin. The technique described here establishes a procedure for estimating the polynomial coefficients from the sample moments of the distribution. Some special cases are worked through symbolically using computer algebra. Real data from the literature recording bus motor failures is used to compare the proposed approach with results based on the least squares procedure.

  19. Security bound of continuous-variable quantum key distribution with noisy coherent states and channel

    Shen Yong; Yang Jian; Guo Hong, E-mail: hongguo@pku.edu.c [CREAM Group, State Key Laboratory of Advanced Optical Communication Systems and Networks (Peking University) and Institute of Quantum Electronics, School of Electronics Engineering and Computer Science, Peking University, Beijing 100871 (China)

    2009-12-14

    Security of a continuous-variable quantum key distribution protocol based on noisy coherent states and channel is analysed. Assuming that the noise of coherent states is induced by Fred, a neutral party relative to others, we prove that the prepare-and-measurement scheme (P and M) and entanglement-based scheme (E-B) are equivalent. Then, we show that this protocol is secure against Gaussian collective attacks even if the channel is lossy and noisy, and, further, a lower bound to the secure key rate is derived.

  20. Continuous energy Monte Carlo calculations for randomly distributed spherical fuels based on statistical geometry model

    Murata, Isao [Osaka Univ., Suita (Japan); Mori, Takamasa; Nakagawa, Masayuki; Itakura, Hirofumi

    1996-03-01

    The method to calculate neutronics parameters of a core composed of randomly distributed spherical fuels has been developed based on a statistical geometry model with a continuous energy Monte Carlo method. This method was implemented in a general purpose Monte Carlo code MCNP, and a new code MCNP-CFP had been developed. This paper describes the model and method how to use it and the validation results. In the Monte Carlo calculation, the location of a spherical fuel is sampled probabilistically along the particle flight path from the spatial probability distribution of spherical fuels, called nearest neighbor distribution (NND). This sampling method was validated through the following two comparisons: (1) Calculations of inventory of coated fuel particles (CFPs) in a fuel compact by both track length estimator and direct evaluation method, and (2) Criticality calculations for ordered packed geometries. This method was also confined by applying to an analysis of the critical assembly experiment at VHTRC. The method established in the present study is quite unique so as to a probabilistic model of the geometry with a great number of spherical fuels distributed randomly. Realizing the speed-up by vector or parallel computations in future, it is expected to be widely used in calculation of a nuclear reactor core, especially HTGR cores. (author).

  1. THE SUPERNOVA DELAY TIME DISTRIBUTION IN GALAXY CLUSTERS AND IMPLICATIONS FOR TYPE-Ia PROGENITORS AND METAL ENRICHMENT

    Maoz, Dan; Sharon, Keren; Avishay Gal-Yam

    2010-01-01

    Knowledge of the supernova (SN) delay time distribution (DTD)-the SN rate versus time that would follow a hypothetical brief burst of star formation-can shed light on SN progenitors and physics, as well as on the timescales of chemical enrichment in different environments. We compile recent measurements of the Type-Ia SN (SN Ia) rate in galaxy clusters at redshifts from z = 0 out to z = 1.45, just 2 Gyr after cluster star formation at z ∼ 3. We review the plausible range for the observed total iron-to-stellar mass ratio in clusters, based on the latest data and analyses, and use it to constrain the time-integrated number of SN Ia events in clusters. With these data, we recover the DTD of SNe Ia in cluster environments. The DTD is sharply peaked at the shortest time-delay interval we probe, 0Gyr -1.2±0.3 from t = 400 Myr to a Hubble time can satisfy both constraints. Shallower power laws such as t -1/2 cannot, assuming a single DTD, and a single star formation burst (either brief or extended) at high z. This implies that 50%-85% of SNe Ia explode within 1 Gyr of star formation. DTDs from double-degenerate (DD) models, which generically have ∼t -1 shapes over a wide range of timescales, match the data, but only if their predictions are scaled up by factors of 5-10. Single-degenerate (SD) DTDs always give poor fits to the data, due to a lack of delayed SNe and overall low numbers of SNe. The observations can also be reproduced with a combination of two SN Ia populations-a prompt SD population of SNe Ia that explodes within a few Gyr of star formation, and produces about 60% of the iron mass in clusters, and a DD population that contributes the events seen at z < 1.5. An alternative scenario of a single, prompt, SN Ia population, but a composite star formation history in clusters, consisting of a burst at high z, followed by a constant star formation rate, can reproduce the SN rates, but is at odds with direct measurements of star formation in clusters at 0 < z

  2. Continuous-variable measurement-device-independent quantum key distribution with virtual photon subtraction

    Zhao, Yijia; Zhang, Yichen; Xu, Bingjie; Yu, Song; Guo, Hong

    2018-04-01

    The method of improving the performance of continuous-variable quantum key distribution protocols by postselection has been recently proposed and verified. In continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocols, the measurement results are obtained from untrusted third party Charlie. There is still not an effective method of improving CV-MDI QKD by the postselection with untrusted measurement. We propose a method to improve the performance of coherent-state CV-MDI QKD protocol by virtual photon subtraction via non-Gaussian postselection. The non-Gaussian postselection of transmitted data is equivalent to an ideal photon subtraction on the two-mode squeezed vacuum state, which is favorable to enhance the performance of CV-MDI QKD. In CV-MDI QKD protocol with non-Gaussian postselection, two users select their own data independently. We demonstrate that the optimal performance of the renovated CV-MDI QKD protocol is obtained with the transmitted data only selected by Alice. By setting appropriate parameters of the virtual photon subtraction, the secret key rate and tolerable excess noise are both improved at long transmission distance. The method provides an effective optimization scheme for the application of CV-MDI QKD protocols.

  3. Preparation of ring-shaped composite bonded magnets with continuously controlled anisotropy distribution for internal space

    Yamashita, F; Yamada, O; Ohya, S; Kobayashi, O; Nakano, M; Fukunaga, H

    2010-01-01

    We have already reported an advanced method for producing a radially-anisotropic rare earth composite bonded magnet with continuously controlled direction of anisotropy. The magnet has been applied to an inner rotor as a practical usage. In this study, the outstanding preparation method was adopted into the preparation of a magnet applied for an outer rotor. An optimized condition of extrusion and compaction at an elevated temperature could be obtained. In addition, a low pressure configuration to the ring-shaped magnet from plural preformed magnets was carried out, which had specific distribution of magnetic anisotropy for internal space for a small motor, by using self recoverability based on the viscous deformation without an alignment field. No deterioration of magnetic properties was detected through the process even if those magnets were miniaturized. Resultantly, the (BH) max of a ring-shaped magnet with the continuously controlled direction of magnetic anisotropy attained the value of 186 kJ/m 3 , and we obtained sine-wave magnetic anisotropy distribution, even if those magnets were miniaturized.

  4. About the distribution of delays in G.M counters; Sur la distribution des retards dans les compteurs G.M

    Picard, E; Rogozinski, A [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

    1954-07-01

    We measure, with an oscillograph method the global time that pass between the time that a particle in a determined region of the studied counter and the answer of the amplifier associated to the counter. This delay is composed of the latency time T{sub l} and the T{sub q} delay, that result from the rise time finished of the impulse and whose value depends of the sensitivity threshold of the amplifier. The selection of (cosmic) particles generating discharge in the studied counter is obtained thanks to a telescope of two meters in coincidence whose opening is limited by a group of four counters in anti-coincidence with the first. The meter is arranged so that the median plan of the telescope crosses to a variable distance d of his axial thread. The measures have been done for different securities of the distance d and of the over-voltage V{sub s} applied to the counter. The results show that the statistical distribution of the delays is more spread especially when d is bigger and V{sub s} more reduced. The average values of the observed delays vary of 7.10{sup -8} s for d = 0 and V{sub s}es = 200 V, to 90.10{sup -8} s for d = 1,9 cm and V{sub s} = 50 V. The mobility of an free electron within the gaseous mixture filling the counter under a pressure of 10 cm.Hg was found equal: (2,1 {+-}0,2).10{sup 4} cm{sup 2}.s{sup -1}.V{sup -1}. (author) [French] On mesure, par une methode oscillographique le temps global qui s'ecoule entre le passage de la particule dans une region determinee du compteur etudie et la reponse de l'amplificateur associe au compteur. Ce retard se compose du temps de latence T{sub l} proprement dit et du retard T{sub q}, qui resulte du temps de montee fini de l'impulsion et dont la valeur depend du seuil de sensibilite de l'amplificateur. La selection des particules (cosmiques) generatrices de la decharge dans le compteur etudie est obtenue grace a un telescope de deux compteurs en coincidence dont l'ouverture est limitee par un groupe de quatre

  5. Mass distribution of free insecticide-treated nets do not interfere with continuous net distribution in Tanzania.

    Eze, Ikenna C; Kramer, Karen; Msengwa, Amina; Mandike, Renata; Lengeler, Christian

    2014-05-27

    To protect the most vulnerable groups from malaria (pregnant women and infants) the Tanzanian Government introduced a subsidy (voucher) scheme in 2004, on the basis of a public-private partnership. These vouchers are provided to pregnant women at their first antenatal care visit and mothers of infants at first vaccination. The vouchers are redeemed at registered retailers for a long-lasting insecticidal net against the payment of a modest top-up price. The present work analysed a large body of data from the Tanzanian National Voucher Scheme, focusing on interactions with concurrent mass distribution campaigns of free nets. In an ecologic study involving all regions of Tanzania, voucher redemption data for the period 2007-2011, as well as data on potential determinants of voucher redemption were analysed. The four outcome variables were: pregnant woman and infant voucher redemption rates, use of treated bed nets by all household members and by under- five children. Each of the outcomes was regressed with selected determinants, using a generalized estimating equation model and accounting for regional data clustering. There was a consistent improvement in voucher redemption rates over the selected time period, with rates >80% in 2011. The major determinants of redemption rates were the top-up price paid by the voucher beneficiary, the retailer- clinic ratio, and socio-economic status. Improved redemption rates after 2009 were most likely due to reduced top-up prices (following a change in policy). Redemption rates were not affected by two major free net distribution campaigns. During this period, there was a consistent improvement in net use across all the regions, with rates of up to 75% in 2011. The key components of the National Treated Nets Programme (NATNETS) seem to work harmoniously, leading to a high level of net use in the entire population. This calls for the continuation of this effort in Tanzania and for emulation by other countries with endemic malaria.

  6. A Distributed Approach to Continuous Monitoring of Constrained k-Nearest Neighbor Queries in Road Networks

    Hyung-Ju Cho

    2012-01-01

    Full Text Available Given two positive parameters k and r, a constrained k-nearest neighbor (CkNN query returns the k closest objects within a network distance r of the query location in road networks. In terms of the scalability of monitoring these CkNN queries, existing solutions based on central processing at a server suffer from a sudden and sharp rise in server load as well as messaging cost as the number of queries increases. In this paper, we propose a distributed and scalable scheme called DAEMON for the continuous monitoring of CkNN queries in road networks. Our query processing is distributed among clients (query objects and server. Specifically, the server evaluates CkNN queries issued at intersections of road segments, retrieves the objects on the road segments between neighboring intersections, and sends responses to the query objects. Finally, each client makes its own query result using this server response. As a result, our distributed scheme achieves close-to-optimal communication costs and scales well to large numbers of monitoring queries. Exhaustive experimental results demonstrate that our scheme substantially outperforms its competitor in terms of query processing time and messaging cost.

  7. Distribution of blood derivatives by registered blood establishments that qualify as health care entities; Prescription Drug Marketing Act of 1987; Prescription Drug Amendments of 1992; delay of applicability date. Final rule; delay of applicability date.

    2006-11-13

    The Food and Drug Administration (FDA) is further delaying, until December 1, 2008, the applicability date of a certain requirement of a final rule published in the Federal Register of December 3, 1999 (64 FR 67720) (the final rule). The final rule implements the Prescription Drug Marketing Act of 1987 (PDMA), as modified by the Prescription Drug Amendments of 1992 (PDA), and the Food and Drug Administration Modernization Act of 1997 (the Modernization Act). The provisions of the final rule became effective on December 4, 2000, except for certain provisions whose effective or applicability dates were delayed in five subsequent Federal Register notices, until December 1, 2006. The provision with the delayed applicability date would prohibit wholesale distribution of blood derivatives by registered blood establishments that meet the definition of a "health care entity." In the Federal Register of February 1, 2006 (71 FR 5200), FDA published a proposed rule specific to the distribution of blood derivatives by registered blood establishments that qualify as health care entities (the proposed rule). The proposed rule would amend certain limited provisions of the final rule to allow certain registered blood establishments that qualify as health care entities to distribute blood derivatives. In response to the proposed rule, FDA received substantive comments. As explained in the SUPPLEMENTARY INFORMATION section of this document, further delaying the applicability of Sec. 203.3(q) (21 CFR 203.3(q)) to the wholesale distribution of blood derivatives by health care entities is necessary to give the agency additional time to address comments on the proposed rule, consider whether regulatory changes are appropriate, and, if so, to initiate such changes.

  8. Time delay occultation data of the Helios spacecraft for probing the electron density distribution in the solar corona

    Edenhofer, P.; Lueneburg, E.; Esposito, P. B.; Martin, W. L.; Zygielbaum, A. I.; Hansen, R. T.; Hansen, S. F.

    1978-01-01

    S-band time delay measurements were collected from the spacecraft Helios A and B during three solar occultations in 1975/76 within heliocentric distances of about 3 and 215 earth radius in terms of range, Doppler frequency shift, and electron content. Characteristic features of measurement and data processing are described. Typical data sets are discussed to probe the electron density distribution near the sun (west and east limb as well) including the outer and extended corona. Steady-state and dynamical aspects of the solar corona are presented and compared with earth-bound-K-coronagraph measurements. Using a weighted least squares estimation, parameters of an average coronal electron density profile are derived in a preliminary analysis to yield electron densities at r = 3, 65, 215 earth radius. Transient phenomena are discussed and a velocity of propagation v is nearly equal to 900 km/s is determined for plasma ejecta from a solar flare observed during an extraordinary set of Helios B electron content measurements.

  9. Improvement of two-way continuous-variable quantum key distribution using optical amplifiers

    Zhang, Yi-Chen; Yu, Song; Gu, Wanyi; Li, Zhengyu; Sun, Maozhu; Peng, Xiang; Guo, Hong; Weedbrook, Christian

    2014-01-01

    The imperfections of a receiver's detector affect the performance of two-way continuous-variable (CV) quantum key distribution (QKD) protocols and are difficult to adjust in practical situations. We propose a method to improve the performance of two-way CV-QKD by adding a parameter-adjustable optical amplifier at the receiver. A security analysis is derived against a two-mode collective entangling cloner attack. Our simulations show that the proposed method can improve the performance of protocols as long as the inherent noise of the amplifier is lower than a critical value, defined as the tolerable amplifier noise. Furthermore, the optimal performance can approach the scenario where a perfect detector is used. (paper)

  10. High performance reconciliation for continuous-variable quantum key distribution with LDPC code

    Lin, Dakai; Huang, Duan; Huang, Peng; Peng, Jinye; Zeng, Guihua

    2015-03-01

    Reconciliation is a significant procedure in a continuous-variable quantum key distribution (CV-QKD) system. It is employed to extract secure secret key from the resulted string through quantum channel between two users. However, the efficiency and the speed of previous reconciliation algorithms are low. These problems limit the secure communication distance and the secure key rate of CV-QKD systems. In this paper, we proposed a high-speed reconciliation algorithm through employing a well-structured decoding scheme based on low density parity-check (LDPC) code. The complexity of the proposed algorithm is reduced obviously. By using a graphics processing unit (GPU) device, our method may reach a reconciliation speed of 25 Mb/s for a CV-QKD system, which is currently the highest level and paves the way to high-speed CV-QKD.

  11. Implementation of continuous-variable quantum key distribution with discrete modulation

    Hirano, Takuya; Ichikawa, Tsubasa; Matsubara, Takuto; Ono, Motoharu; Oguri, Yusuke; Namiki, Ryo; Kasai, Kenta; Matsumoto, Ryutaroh; Tsurumaru, Toyohiro

    2017-06-01

    We have developed a continuous-variable quantum key distribution (CV-QKD) system that employs discrete quadrature-amplitude modulation and homodyne detection of coherent states of light. We experimentally demonstrated automated secure key generation with a rate of 50 kbps when a quantum channel is a 10 km optical fibre. The CV-QKD system utilises a four-state and post-selection protocol and generates a secure key against the entangling cloner attack. We used a pulsed light source of 1550 nm wavelength with a repetition rate of 10 MHz. A commercially available balanced receiver is used to realise shot-noise-limited pulsed homodyne detection. We used a non-binary LDPC code for error correction (reverse reconciliation) and the Toeplitz matrix multiplication for privacy amplification. A graphical processing unit card is used to accelerate the software-based post-processing.

  12. High-efficiency Gaussian key reconciliation in continuous variable quantum key distribution

    Bai, ZengLiang; Wang, XuYang; Yang, ShenShen; Li, YongMin

    2016-01-01

    Efficient reconciliation is a crucial step in continuous variable quantum key distribution. The progressive-edge-growth (PEG) algorithm is an efficient method to construct relatively short block length low-density parity-check (LDPC) codes. The qua-sicyclic construction method can extend short block length codes and further eliminate the shortest cycle. In this paper, by combining the PEG algorithm and qua-si-cyclic construction method, we design long block length irregular LDPC codes with high error-correcting capacity. Based on these LDPC codes, we achieve high-efficiency Gaussian key reconciliation with slice recon-ciliation based on multilevel coding/multistage decoding with an efficiency of 93.7%.

  13. Continuous-variable measurement-device-independent quantum key distribution with photon subtraction

    Ma, Hong-Xin; Huang, Peng; Bai, Dong-Yun; Wang, Shi-Yu; Bao, Wan-Su; Zeng, Gui-Hua

    2018-04-01

    It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and one-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.

  14. Quantum key distribution using continuous-variable non-Gaussian states

    Borelli, L. F. M.; Aguiar, L. S.; Roversi, J. A.; Vidiella-Barranco, A.

    2016-02-01

    In this work, we present a quantum key distribution protocol using continuous-variable non-Gaussian states, homodyne detection and post-selection. The employed signal states are the photon added then subtracted coherent states (PASCS) in which one photon is added and subsequently one photon is subtracted from the field. We analyze the performance of our protocol, compared with a coherent state-based protocol, for two different attacks that could be carried out by the eavesdropper (Eve). We calculate the secret key rate transmission in a lossy line for a superior channel (beam-splitter) attack, and we show that we may increase the secret key generation rate by using the non-Gaussian PASCS rather than coherent states. We also consider the simultaneous quadrature measurement (intercept-resend) attack, and we show that the efficiency of Eve's attack is substantially reduced if PASCS are used as signal states.

  15. VORTICAL MODEL OF THE WING COVERED WITH CONTINUOUSLY DISTRIBUTED CIRCULATION OF THE VORTICAL LAYER

    B. L. Artamonov

    2014-01-01

    Full Text Available The linear vortical model ot the final scope of a wing is exsamined. It representis the flat rectangular spatial veil covered with continuously distributed vortical layer. Elements of digitization of a veil are the quadrangular panels laying on its surface. Method, algorithms and the program of calculation of three making vectors of inductive speed from any guided rectangular platform covered with a vortical layer are created. Its intensity linearly changes on the surface of a platform. The decision is received in elementary functions. The numerical way solves the task of a definition of the law of circulation of the attached whirlwinds in scope of a wing and calculation of its aerodynamic characteristics, being based on the accepted vortical model and a hypothesis of flat sections.

  16. Self-referenced continuous-variable measurement-device-independent quantum key distribution

    Wang, Yijun; Wang, Xudong; Li, Jiawei; Huang, Duan; Zhang, Ling; Guo, Ying

    2018-05-01

    We propose a scheme to remove the demand of transmitting a high-brightness local oscillator (LO) in continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, which we call as the self-referenced (SR) CV-MDI QKD. We show that our scheme is immune to the side-channel attacks, such as the calibration attacks, the wavelength attacks and the LO fluctuation attacks, which are all exploiting the security loopholes introduced by transmitting the LO. Besides, the proposed scheme waives the necessity of complex multiplexer and demultiplexer, which can greatly simplify the QKD processes and improve the transmission efficiency. The numerical simulations under collective attacks show that all the improvements brought about by our scheme are only at the expense of slight transmission distance shortening. This scheme shows an available method to mend the security loopholes incurred by transmitting LO in CV-MDI QKD.

  17. Finite-size analysis of continuous-variable measurement-device-independent quantum key distribution

    Zhang, Xueying; Zhang, Yichen; Zhao, Yijia; Wang, Xiangyu; Yu, Song; Guo, Hong

    2017-10-01

    We study the impact of the finite-size effect on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI QKD) protocol, mainly considering the finite-size effect on the parameter estimation procedure. The central-limit theorem and maximum likelihood estimation theorem are used to estimate the parameters. We also analyze the relationship between the number of exchanged signals and the optimal modulation variance in the protocol. It is proved that when Charlie's position is close to Bob, the CV-MDI QKD protocol has the farthest transmission distance in the finite-size scenario. Finally, we discuss the impact of finite-size effects related to the practical detection in the CV-MDI QKD protocol. The overall results indicate that the finite-size effect has a great influence on the secret-key rate of the CV-MDI QKD protocol and should not be ignored.

  18. Practical security analysis of continuous-variable quantum key distribution with jitter in clock synchronization

    Xie, Cailang; Guo, Ying; Liao, Qin; Zhao, Wei; Huang, Duan; Zhang, Ling; Zeng, Guihua

    2018-03-01

    How to narrow the gap of security between theory and practice has been a notoriously urgent problem in quantum cryptography. Here, we analyze and provide experimental evidence of the clock jitter effect on the practical continuous-variable quantum key distribution (CV-QKD) system. The clock jitter is a random noise which exists permanently in the clock synchronization in the practical CV-QKD system, it may compromise the system security because of its impact on data sampling and parameters estimation. In particular, the practical security of CV-QKD with different clock jitter against collective attack is analyzed theoretically based on different repetition frequencies, the numerical simulations indicate that the clock jitter has more impact on a high-speed scenario. Furthermore, a simplified experiment is designed to investigate the influence of the clock jitter.

  19. Synchronization of conference presentation sequence using delay equalization approach

    Godavari, Rakesh K.; Celenk, Mehmet

    2001-11-01

    In this paper, a delay equalization approach is proposed for cohesive conference presentation with minimal screen- freezing effect. The underlying screen-freezing effect is due to varying delays in the communication channels involved in broadcasting. In turn, this poses a threat to the goal of uniform delay distribution among data packets for synchronized presentation broadcast. We wish to achieve uniformity among packet arrival times to the recipients. This objective is achieved by transforming a given input delay distribution (D) to the desired output density through a delay equalization process. Considering a general case of between packet and frame delay distributions for a given input, the desired output is obtained through a delay equalization process. In case of a specific normal delay distribution, a memory-less system g(D) is determined as an approximation to the delay equalizer such that the equalizer output O(t)equalsg[D(t)] is uniformly distributed in the allowable delay limits of (a,b) assuring the specified quality of service (QoS) parameters. The corresponding delay is added at each recipient workstation, which acts as the wait period required before it begins its designated presentation.For a zero mean normal delay density case, the equalizer transfer function can be given in a closed from solution as O(t)equalsg[D(t)[equals(b-a)]0.5+eft(-D/$RO OTR(0)))[+a, where erf(x) is the standard error function. The histogram approximation is adopted as an asymptotically delay equalization means for general cases. This technique provides a means for modifying the dynamic range of data acquired by altering it into a desired distribution. In experimentation, equalizer characteristic functions are derived for a set of selected input delays to obtain the desired output. The delay equalizer system developed here is suited for deployment in a distributed hierarchical conferencing environment. To accommodate a broadcast continuity, the multimedia presentation is

  20. Security of Continuous-Variable Quantum Key Distribution via a Gaussian de Finetti Reduction

    Leverrier, Anthony

    2017-05-01

    Establishing the security of continuous-variable quantum key distribution against general attacks in a realistic finite-size regime is an outstanding open problem in the field of theoretical quantum cryptography if we restrict our attention to protocols that rely on the exchange of coherent states. Indeed, techniques based on the uncertainty principle are not known to work for such protocols, and the usual tools based on de Finetti reductions only provide security for unrealistically large block lengths. We address this problem here by considering a new type of Gaussian de Finetti reduction, that exploits the invariance of some continuous-variable protocols under the action of the unitary group U (n ) (instead of the symmetric group Sn as in usual de Finetti theorems), and by introducing generalized S U (2 ,2 ) coherent states. Crucially, combined with an energy test, this allows us to truncate the Hilbert space globally instead as at the single-mode level as in previous approaches that failed to provide security in realistic conditions. Our reduction shows that it is sufficient to prove the security of these protocols against Gaussian collective attacks in order to obtain security against general attacks, thereby confirming rigorously the widely held belief that Gaussian attacks are indeed optimal against such protocols.

  1. Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

    Rastogi, Achal

    2017-08-15

    Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

  2. Continuous gene flow contributes to low global species abundance and distribution of a marine model diatom

    Rastogi, Achal; Deton-Cabanillas, Anne-Flore; Rocha Jimenez Vieira, Fabio; Veluchamy, Alaguraj; Cantrel, Catherine; Wang, Gaohong; Vanormelingen, Pieter; Bowler, Chris; Piganeau, Gwenael; Tirichine, Leila; Hu, Hanhua

    2017-01-01

    Unlike terrestrial ecosystems where geographical isolation often leads to a restricted gene flow between species, genetic admixing in aquatic micro-eukaryotes is likely to be frequent. Diatoms inhabit marine ecosystems since the Mesozoic period and presently constitute one of the major primary producers in the world ocean. They are a highly diversified group of eukaryotic phytoplankton with estimates of up to 200,000 species. Since decades, Phaeodactylum tricornutum is used as a model diatom species to characterize the functional pathways, physiology and evolution of diatoms in general. In the current study, using whole genome sequencing of ten P. tricornutum strains, sampled at broad geospatial and temporal scales, we show a continuous dispersal and genetic admixing between geographically isolated strains. We also describe a very high level of heterozygosity and propose it to be a consequence of frequent ancestral admixture. Our finding that P. tricornutum sequences are plausibly detectable at low but broadly distributed levels in the world ocean further suggests that high admixing between geographically isolated strains may create a significant bottleneck, thus influencing their global abundance and distribution in nature. Finally, in an attempt to understand the functional implications of genetic diversity between different P. tricornutum ecotypes, we show the effects of domestication in inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success.

  3. Continuous Real-time Measurements of Vertical Distribution of Magnetic Susceptibility In Soils

    Petrovsky, E.; Hulka, Z.; Kapicka, A.; Magprox Team

    Measurements of top-soil magnetic susceptibility are used in approximative outlining polluted areas. However, one of the serious limitations of the method is discrimina- tion between top-soil layers enhanced by atmospherically deposited anthropogenic particles from those dominated by natural particles migrating from magnetically-rich basement rocks. For this purpose, measurements of vertical distribution of magnetic susceptibility along soil profiles is one of the most effective ways in estimating the effect of lithogenic contribution. Up to now, in most cases soil cores have to be mea- sured in laboratory. This method is quite time consuming and does not allow flexible decision about the suitability of the measured site for surface magnetic mapping. In our contribution we will present a new device enabling continuous real-time measure- ments of vertical distribution of magnetic susceptibility directly in field, performed in holes after soil coring. The method is fast, yielding smooth curves (6 data points per 1 mm dept), at least as sensitive as laboratory methods available until now, and at- tached notebook enables direct, on-line control of the lithogenic versus anthropogenic contributions.

  4. Gauss-Kronrod-Trapezoidal Integration Scheme for Modeling Biological Tissues with Continuous Fiber Distributions

    Hou, Chieh; Ateshian, Gerard A.

    2015-01-01

    Fibrous biological tissues may be modeled using a continuous fiber distribution (CFD) to capture tension-compression nonlinearity, anisotropic fiber distributions, and load-induced anisotropy. The CFD framework requires spherical integration of weighted individual fiber responses, with fibers contributing to the stress response only when they are in tension. The common method for performing this integration employs the discretization of the unit sphere into a polyhedron with nearly uniform triangular faces (finite element integration or FEI scheme). Although FEI has proven to be more accurate and efficient than integration using spherical coordinates, it presents three major drawbacks: First, the number of elements on the unit sphere needed to achieve satisfactory accuracy becomes a significant computational cost in a finite element analysis. Second, fibers may not be in tension in some regions on the unit sphere, where the integration becomes a waste. Third, if tensed fiber bundles span a small region compared to the area of the elements on the sphere, a significant discretization error arises. This study presents an integration scheme specialized to the CFD framework, which significantly mitigates the first drawback of the FEI scheme, while eliminating the second and third completely. Here, integration is performed only over the regions of the unit sphere where fibers are in tension. Gauss-Kronrod quadrature is used across latitudes and the trapezoidal scheme across longitudes. Over a wide range of strain states, fiber material properties, and fiber angular distributions, results demonstrate that this new scheme always outperforms FEI, sometimes by orders of magnitude in the number of computational steps and relative accuracy of the stress calculation. PMID:26291492

  5. A Gauss-Kronrod-Trapezoidal integration scheme for modeling biological tissues with continuous fiber distributions.

    Hou, Chieh; Ateshian, Gerard A

    2016-01-01

    Fibrous biological tissues may be modeled using a continuous fiber distribution (CFD) to capture tension-compression nonlinearity, anisotropic fiber distributions, and load-induced anisotropy. The CFD framework requires spherical integration of weighted individual fiber responses, with fibers contributing to the stress response only when they are in tension. The common method for performing this integration employs the discretization of the unit sphere into a polyhedron with nearly uniform triangular faces (finite element integration or FEI scheme). Although FEI has proven to be more accurate and efficient than integration using spherical coordinates, it presents three major drawbacks: First, the number of elements on the unit sphere needed to achieve satisfactory accuracy becomes a significant computational cost in a finite element (FE) analysis. Second, fibers may not be in tension in some regions on the unit sphere, where the integration becomes a waste. Third, if tensed fiber bundles span a small region compared to the area of the elements on the sphere, a significant discretization error arises. This study presents an integration scheme specialized to the CFD framework, which significantly mitigates the first drawback of the FEI scheme, while eliminating the second and third completely. Here, integration is performed only over the regions of the unit sphere where fibers are in tension. Gauss-Kronrod quadrature is used across latitudes and the trapezoidal scheme across longitudes. Over a wide range of strain states, fiber material properties, and fiber angular distributions, results demonstrate that this new scheme always outperforms FEI, sometimes by orders of magnitude in the number of computational steps and relative accuracy of the stress calculation.

  6. Effects of High Frequency Repeated Transcranial Magnetic Stimulation and Continuous Theta Burst Stimulation on Gambling Reinforcement, Delay Discounting, and Stroop Interference in Men with Pathological Gambling.

    Zack, Martin; Cho, Sang Soo; Parlee, Jennifer; Jacobs, Mark; Li, Crystal; Boileau, Isabelle; Strafella, Antonio

    Repeated transcranial magnetic stimulation (rTMS) can reduce cravings and improve cognitive function in substance dependent individuals. Whether these benefits extend to individuals with pathological gambling (PG) is unclear. High-frequency rTMS of the medial prefrontal cortex (PFC) and continuous theta burst stimulation (cTBS) of the right dorsolateral PFC can reduce impulsive choice in healthy volunteers. This study aimed to assess the effects of these two protocols on gambling reinforcement and related responses in otherwise healthy men with PG. Participants (n = 9) underwent active or sham treatments at weekly intervals in a repeated-measures, Latin square design. Subjective and physiological responses were assessed before and after a 15-min slot machine game on each session. Delay discounting and Stroop tasks measured post-game impulsive choice and attentional control. Multivariate analysis of covariance, controlling for winnings on the slot machine under each treatment, found that rTMS reduced the post-game increase in Desire to Gamble; cTBS reduced amphetamine-like effects, and decreased diastolic blood pressure. Treatment had no significant univariate effects on bet size or speed of play in the game; however, a multivariate effect for the two indices suggested that treatment decreased behavioral activation. Neither treatment reduced impulsive choice, while both treatments increased Stroop interference. rTMS and cTBS can reduce gambling reinforcement in non-comorbid men with PG. Separate processes appear to mediate gambling reinforcement and betting behavior as against delay discounting and Stroop interference. Interventions that modify risky as opposed to temporal aspects of decision making may better predict therapeutic response in PG. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Finite-time hybrid projective synchronization of the drive-response complex networks with distributed-delay via adaptive intermittent control

    Cheng, Lin; Yang, Yongqing; Li, Li; Sui, Xin

    2018-06-01

    This paper studies the finite-time hybrid projective synchronization of the drive-response complex networks. In the model, general transmission delays and distributed delays are also considered. By designing the adaptive intermittent controllers, the response network can achieve hybrid projective synchronization with the drive system in finite time. Based on finite-time stability theory and several differential inequalities, some simple finite-time hybrid projective synchronization criteria are derived. Two numerical examples are given to illustrate the effectiveness of the proposed method.

  8. Impact of different satellite soil moisture products on the predictions of a continuous distributed hydrological model

    Laiolo, P.; Gabellani, S.; Campo, L.; Silvestro, F.; Delogu, F.; Rudari, R.; Pulvirenti, L.; Boni, G.; Fascetti, F.; Pierdicca, N.; Crapolicchio, R.; Hasenauer, S.; Puca, S.

    2016-06-01

    The reliable estimation of hydrological variables in space and time is of fundamental importance in operational hydrology to improve the flood predictions and hydrological cycle description. Nowadays remotely sensed data can offer a chance to improve hydrological models especially in environments with scarce ground based data. The aim of this work is to update the state variables of a physically based, distributed and continuous hydrological model using four different satellite-derived data (three soil moisture products and a land surface temperature measurement) and one soil moisture analysis to evaluate, even with a non optimal technique, the impact on the hydrological cycle. The experiments were carried out for a small catchment, in the northern part of Italy, for the period July 2012-June 2013. The products were pre-processed according to their own characteristics and then they were assimilated into the model using a simple nudging technique. The benefits on the model predictions of discharge were tested against observations. The analysis showed a general improvement of the model discharge predictions, even with a simple assimilation technique, for all the assimilation experiments; the Nash-Sutcliffe model efficiency coefficient was increased from 0.6 (relative to the model without assimilation) to 0.7, moreover, errors on discharge were reduced up to the 10%. An added value to the model was found in the rainfall season (autumn): all the assimilation experiments reduced the errors up to the 20%. This demonstrated that discharge prediction of a distributed hydrological model, which works at fine scale resolution in a small basin, can be improved with the assimilation of coarse-scale satellite-derived data.

  9. Integration of genetic and demographic data to assess population risk in a continuously distributed species

    Fedy, Bradley C.; Row, Jeffery R.; Oyler-McCance, Sara J.

    2017-01-01

    The identification and demographic assessment of biologically meaningful populations is fundamental to species’ ecology and management. Although genetic tools are used frequently to identify populations, studies often do not incorporate demographic data to understand their respective population trends. We used genetic data to define subpopulations in a continuously distributed species. We assessed demographic independence and variation in population trends across the distribution. Additionally, we identified potential barriers to gene flow among subpopulations. We sampled greater sage-grouse (Centrocercus urophasianus) leks from across their range (≈175,000 Km2) in Wyoming and amplified DNA at 14 microsatellite loci for 1761 samples. Subsequently, we assessed population structure in unrelated individuals (n = 872) by integrating results from multiple Bayesian clustering approaches and used the boundaries to inform our assessment of long-term population trends and lek activity over the period of 1995–2013. We identified four genetic clusters of which two northern ones showed demographic independence from the others. Trends in population size for the northwest subpopulation were statistically different from the other three genetic clusters and the northeast and southwest subpopulations demonstrated a general trend of increasing proportion of inactive leks over time. Population change from 1996 to 2012 suggested population growth in the southern subpopulations and decline, or neutral, change in the northern subpopulations. We suggest that sage-grouse subpopulations in northern Wyoming are at greater risk of extirpation than the southern subpopulations due to smaller census and effective population sizes and higher variability within subpopulations. Our research is an example of incorporating genetic and demographic data and provides guidance on the identification of subpopulations of conservation concern.

  10. Assimilation of remote sensing observations into a continuous distributed hydrological model: impacts on the hydrologic cycle

    Laiolo, Paola; Gabellani, Simone; Campo, Lorenzo; Cenci, Luca; Silvestro, Francesco; Delogu, Fabio; Boni, Giorgio; Rudari, Roberto

    2015-04-01

    The reliable estimation of hydrological variables (e.g. soil moisture, evapotranspiration, surface temperature) in space and time is of fundamental importance in operational hydrology to improve the forecast of the rainfall-runoff response of catchments and, consequently, flood predictions. Nowadays remote sensing can offer a chance to provide good space-time estimates of several hydrological variables and then improve hydrological model performances especially in environments with scarce in-situ data. This work investigates the impact of the assimilation of different remote sensing products on the hydrological cycle by using a continuous physically based distributed hydrological model. Three soil moisture products derived by ASCAT (Advanced SCATterometer) are used to update the model state variables. The satellite-derived products are assimilated into the hydrological model using different assimilation techniques: a simple nudging and the Ensemble Kalman Filter. Moreover two assimilation strategies are evaluated to assess the impact of assimilating the satellite products at model spatial resolution or at the satellite scale. The experiments are carried out for three Italian catchments on multi year period. The benefits on the model predictions of discharge, LST, evapotranspiration and soil moisture dynamics are tested and discussed.

  11. Quantum hacking: Saturation attack on practical continuous-variable quantum key distribution

    Qin, Hao; Kumar, Rupesh; Alléaume, Romain

    2016-07-01

    We identify and study a security loophole in continuous-variable quantum key distribution (CVQKD) implementations, related to the imperfect linearity of the homodyne detector. By exploiting this loophole, we propose an active side-channel attack on the Gaussian-modulated coherent-state CVQKD protocol combining an intercept-resend attack with an induced saturation of the homodyne detection on the receiver side (Bob). We show that an attacker can bias the excess noise estimation by displacing the quadratures of the coherent states received by Bob. We propose a saturation model that matches experimental measurements on the homodyne detection and use this model to study the impact of the saturation attack on parameter estimation in CVQKD. We demonstrate that this attack can bias the excess noise estimation beyond the null key threshold for any system parameter, thus leading to a full security break. If we consider an additional criterion imposing that the channel transmission estimation should not be affected by the attack, then the saturation attack can only be launched if the attenuation on the quantum channel is sufficient, corresponding to attenuations larger than approximately 6 dB. We moreover discuss the possible countermeasures against the saturation attack and propose a countermeasure based on Gaussian postselection that can be implemented by classical postprocessing and may allow one to distill the secret key when the raw measurement data are partly saturated.

  12. Entanglement-distillation attack on continuous-variable quantum key distribution in a turbulent atmospheric channel

    Guo, Ying; Xie, Cailang; Liao, Qin; Zhao, Wei; Zeng, Guihua; Huang, Duan

    2017-08-01

    The survival of Gaussian quantum states in a turbulent atmospheric channel is of crucial importance in free-space continuous-variable (CV) quantum key distribution (QKD), in which the transmission coefficient will fluctuate in time, thus resulting in non-Gaussian quantum states. Different from quantum hacking of the imperfections of practical devices, here we propose a different type of attack by exploiting the security loopholes that occur in a real lossy channel. Under a turbulent atmospheric environment, the Gaussian states are inevitably afflicted by decoherence, which would cause a degradation of the transmitted entanglement. Therefore, an eavesdropper can perform an intercept-resend attack by applying an entanglement-distillation operation on the transmitted non-Gaussian mixed states, which allows the eavesdropper to bias the estimation of the parameters and renders the final keys shared between the legitimate parties insecure. Our proposal highlights the practical CV QKD vulnerabilities with free-space quantum channels, including the satellite-to-earth links, ground-to-ground links, and a link from moving objects to ground stations.

  13. Pilot-multiplexed continuous-variable quantum key distribution with a real local oscillator

    Wang, Tao; Huang, Peng; Zhou, Yingming; Liu, Weiqi; Zeng, Guihua

    2018-01-01

    We propose a pilot-multiplexed continuous-variable quantum key distribution (CVQKD) scheme based on a local local oscillator (LLO). Our scheme utilizes time-multiplexing and polarization-multiplexing techniques to dramatically isolate the quantum signal from the pilot, employs two heterodyne detectors to separately detect the signal and the pilot, and adopts a phase compensation method to almost eliminate the multifrequency phase jitter. In order to analyze the performance of our scheme, a general LLO noise model is constructed. Besides the phase noise and the modulation noise, the photon-leakage noise from the reference path and the quantization noise due to the analog-to-digital converter (ADC) are also considered, which are first analyzed in the LLO regime. Under such general noise model, our scheme has a higher key rate and longer secure distance compared with the preexisting LLO schemes. Moreover, we also conduct an experiment to verify our pilot-multiplexed scheme. Results show that it maintains a low level of the phase noise and is expected to obtain a 554-Kbps secure key rate within a 15-km distance under the finite-size effect.

  14. An integral equation method for discrete and continuous distribution of centres in thermoluminescence kinetics

    Kantorovich, L.N.; Fogel, G.M.; Gotlib, V.I.

    1990-01-01

    Thermoluminescence kinetics is discussed within the framework of a band model containing an arbitrary number of types of recombination and trapping centres at an arbitrary correlation of all centre parameters. It is shown that the initial system of kinetic equations is reduced to an equivalent system consisting of two integro-differential equations which permit one to perform an accurate generalisation, in the case of a continuous centre distribution, to their parameters for the description of irradiation and thermoluminescence, taking into account charge carrier redistribution to both types of centre. In addition, if only one electron (hole) channel is taken into account, only one integro-differential equation is obtained. On the basis of this equation a precise algebraic equation is obtained for calculation of the area of an arbitrary part of the thermoluminescence curve (TLC), consisting of one or several peaks, which slightly overlap with other peaks. It is shown that at doses which are less than the saturation dose, when the centres are not completely filled by the charge carriers, the dose dependences of such a part of the TLC may have a non-linear character at a simultaneous linear dependence of the area of the whole TLC. At doses which are greater than the saturation dose, the dose dependences of the area of the whole TLC, as well as of its separate parts, undergo breaks at the saturation doses. (author)

  15. Four-State Continuous-Variable Quantum Key Distribution with Photon Subtraction

    Li, Fei; Wang, Yijun; Liao, Qin; Guo, Ying

    2018-06-01

    Four-state continuous-variable quantum key distribution (CVQKD) is one of the discretely modulated CVQKD which generates four nonorthogonal coherent states and exploits the sign of the measured quadrature of each state to encode information rather than uses the quadrature \\hat {x} or \\hat {p} itself. It has been proven that four-state CVQKD is more suitable than Gaussian modulated CVQKD in terms of transmission distance. In this paper, we propose an improved four-state CVQKD using an non-Gaussian operation, photon subtraction. A suitable photon-subtraction operation can be exploited to improve the maximal transmission of CVQKD in point-to-point quantum communication since it provides a method to enhance the performance of entanglement-based (EB) CVQKD. Photon subtraction not only can lengthen the maximal transmission distance by increasing the signal-to-noise rate but also can be easily implemented with existing technologies. Security analysis shows that the proposed scheme can lengthen the maximum transmission distance. Furthermore, by taking finite-size effect into account we obtain a tighter bound of the secure distance, which is more practical than that obtained in the asymptotic limit.

  16. Pulsar discoveries by volunteer distributed computing and the strongest continuous gravitational wave signal

    Knispel, Benjamin

    2011-07-01

    Neutron stars are the endpoints of stellar evolution and one of the most compact forms of matter in the universe. They can be observed as radio pulsars and are promising sources for the emission of continuous gravitational waves. Discovering new radio pulsars in tight binary orbits offers the opportunity to conduct very high precision tests of General Relativity and to further our understanding of neutron star structure and matter at super-nuclear densities. The direct detection of gravitational waves would validate Einstein's theory of Relativity and open a new window to the universe by offering a novel astronomical tool. This thesis addresses both of these scientific fields: the first fully coherent search for radio pulsars in tight, circular orbits has been planned, set up and conducted in the course of this thesis. Two unusual radio pulsars, one of them in a binary system, have been discovered. The other half of this thesis is concerned with the simulation of the Galactic neutron star population to predict their emission of continuous gravitational waves. First realistic statistical upper limits on the strongest continuous gravitational-wave signal and detection predictions for realistic all-sky blind searches have been obtained. The data from a large-scale pulsar survey with the 305-m Arecibo radio telescope were searched for signals from radio pulsars in binary orbits. The massive amount of computational work was done on hundreds of thousands of computers volunteered by members of the general public through the distributed computing project Einstein@Home. The newly developed analysis pipeline searched for pulsar spin frequencies below 250 Hz and for orbital periods as short as 11 min. The structure of the search pipeline consisting of data preparation, data analysis, result post-processing, and set-up of the pipeline components is presented in detail. The first radio pulsar, discovered with this search, PSR J2007+2722, is an isolated radio pulsar, likely from

  17. Existence and Globally Asymptotic Stability of Equilibrium Solution for Fractional-Order Hybrid BAM Neural Networks with Distributed Delays and Impulses

    Hai Zhang

    2017-01-01

    Full Text Available This paper investigates the existence and globally asymptotic stability of equilibrium solution for Riemann-Liouville fractional-order hybrid BAM neural networks with distributed delays and impulses. The factors of such network systems including the distributed delays, impulsive effects, and two different fractional-order derivatives between the U-layer and V-layer are taken into account synchronously. Based on the contraction mapping principle, the sufficient conditions are derived to ensure the existence and uniqueness of the equilibrium solution for such network systems. By constructing a novel Lyapunov functional composed of fractional integral and definite integral terms, the globally asymptotic stability criteria of the equilibrium solution are obtained, which are dependent on the order of fractional derivative and network parameters. The advantage of our constructed method is that one may directly calculate integer-order derivative of the Lyapunov functional. A numerical example is also presented to show the validity and feasibility of the theoretical results.

  18. Stiffness distribution in insect cuticle: a continuous or a discontinuous profile?

    Rajabi, H; Jafarpour, M; Darvizeh, A; Dirks, J-H; Gorb, S N

    2017-07-01

    Insect cuticle is a biological composite with a high degree of complexity in terms of both architecture and material composition. Given the complex morphology of many insect body parts, finite-element (FE) models play an important role in the analysis and interpretation of biomechanical measurements, taken by either macroscopic or nanoscopic techniques. Many previous studies show that the interpretation of nanoindentation measurements of this layered composite material is very challenging. To develop accurate FE models, it is of particular interest to understand more about the variations in the stiffness through the thickness of the cuticle. Considering the difficulties of making direct measurements, in this study, we use the FE method to analyse previously published data and address this issue numerically. For this purpose, sets of continuous or discontinuous stiffness profiles through the thickness of the cuticle were mathematically described. The obtained profiles were assigned to models developed based on the cuticle of three insect species with different geometries and layer configurations. The models were then used to simulate the mechanical behaviour of insect cuticles subjected to nanoindentation experiments. Our results show that FE models with discontinuous exponential stiffness gradients along their thickness were able to predict the stress and deformation states in insect cuticle very well. Our results further suggest that, for more accurate measurements and interpretation of nanoindentation test data, the ratio of the indentation depth to cuticle thickness should be limited to 7% rather than the traditional '10% rule'. The results of this study thus might be useful to provide a deeper insight into the biomechanical consequences of the distinct material distribution in insect cuticle and also to form a basis for more realistic modelling of this complex natural composite. © 2017 The Author(s).

  19. Free-volume distributions of polymers by positron annihilation spectroscopy: further experiences in using CONTIN for continuous lifetime distributions

    Dai, G.H.; Jean, Y.C.

    1995-01-01

    Thorough examinations of the CONTIN program were carried out by using the simulated positron lifetime spectra, to reveal the capability of CONTIN in the reconstruction of the positron lifetime distributions. It is shown that: 1. very high statistics is strongly desired by CONTIN to reproduce reliable lifetime distributions; 2. improving the time resolution of the measurement system, to the level of 0.030 ns full width at half maximum, does not significantly improve the resolving power of CONTIN; and 3. reducing the time width per channel is a practical way of improving the reconstruction of the lifetime probability density functions by CONTIN. (orig.)

  20. Continuous Distributed Top-k Monitoring over High-Speed Rail Data Stream in Cloud Computing Environment

    Hanning Wang

    2013-01-01

    Full Text Available In the environment of cloud computing, real-time mass data about high-speed rail which is based on the intense monitoring of large scale perceived equipment provides strong support for the safety and maintenance of high-speed rail. In this paper, we focus on the Top-k algorithm of continuous distribution based on Multisource distributed data stream for high-speed rail monitoring. Specifically, we formalized Top-k monitoring model of high-speed rail and proposed DTMR that is the Top-k monitoring algorithm with random, continuous, or strictly monotone aggregation functions. The DTMR was proved to be valid by lots of experiments.

  1. Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks.

    Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F; Schnabel, Roman

    2015-10-30

    Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.

  2. Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks

    Gehring, Tobias; Händchen, Vitus; Duhme, Jörg; Furrer, Fabian; Franz, Torsten; Pacher, Christoph; Werner, Reinhard F.; Schnabel, Roman

    2015-10-01

    Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our implementation is based on the distribution of continuous-variable Einstein-Podolsky-Rosen entangled light. It is one-sided device independent, which means the security of the generated key is independent of any memoryfree attacks on the remote detector. Since continuous-variable encoding is compatible with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components.

  3. Implementation of continuous-variable quantum key distribution with composable and one-sided-device-independent security against coherent attacks

    Gehring, Tobias; Haendchen, Vitus; Duhme, Joerg

    2015-01-01

    Secret communication over public channels is one of the central pillars of a modern information society. Using quantum key distribution this is achieved without relying on the hardness of mathematical problems, which might be compromised by improved algorithms or by future quantum computers. State......-of-the-art quantum key distribution requires composable security against coherent attacks for a finite number of distributed quantum states as well as robustness against implementation side channels. Here we present an implementation of continuous-variable quantum key distribution satisfying these requirements. Our...... with conventional optical communication technology, our work is a step towards practical implementations of quantum key distribution with state-of-the-art security based solely on telecom components....

  4. Damage identification method for continuous girder bridges based on spatially-distributed long-gauge strain sensing under moving loads

    Wu, Bitao; Wu, Gang; Yang, Caiqian; He, Yi

    2018-05-01

    A novel damage identification method for concrete continuous girder bridges based on spatially-distributed long-gauge strain sensing is presented in this paper. First, the variation regularity of the long-gauge strain influence line of continuous girder bridges which changes with the location of vehicles on the bridge is studied. According to this variation regularity, a calculation method for the distribution regularity of the area of long-gauge strain history is investigated. Second, a numerical simulation of damage identification based on the distribution regularity of the area of long-gauge strain history is conducted, and the results indicate that this method is effective for identifying damage and is not affected by the speed, axle number and weight of vehicles. Finally, a real bridge test on a highway is conducted, and the experimental results also show that this method is very effective for identifying damage in continuous girder bridges, and the local element stiffness distribution regularity can be revealed at the same time. This identified information is useful for maintaining of continuous girder bridges on highways.

  5. Effect of tillage on water advance and distribution under surge and continuous furrow irrigation methods for cotton in Egypt

    Ismail, S.M.

    2006-01-01

    A field experiment was carried out to assess the effect of tillage on water advance and water distribution in the root zone area (0.5 m) under continuous and surge flow irrigation in a cotton field. The experiment was conducted at the Agriculture Experimental Station, Assiut University, Assiut,

  6. Distribution of sulfur aerosol precursors in the SPCZ released by continuous volcanic degassing at Ambrym, Vanuatu

    Lefèvre, Jérôme; Menkes, Christophe; Bani, Philipson; Marchesiello, Patrick; Curci, Gabriele; Grell, Georg A.; Frouin, Robert

    2016-08-01

    The Melanesian Volcanic Arc (MVA) emits about 12 kT d- 1 of sulfur dioxide (SO2) to the atmosphere from continuous passive (non-explosive) volcanic degassing, which contributes 20% of the global SO2 emission from volcanoes. Here we assess, from up-to-date and long-term observations, the SO2 emission of the Ambrym volcano, one of the dominant volcanoes in the MVA, and we investigate its role as sulfate precursor on the regional distribution of aerosols, using both satellite observations and model results at 1° × 1° spatial resolution from WRF-Chem/GOCART. Without considering aerosol forcing on clouds, our model parameterizations for convection, vertical mixing and cloud properties provide a reliable chemical weather representation, making possible a cross-examination of model solution and observations. This preliminary work enables the identification of biases and limitations affecting both the model (missing sources) and satellite sensors and algorithms (for aerosol detection and classification) and leads to the implementation of improved transport and aerosol processes in the modeling system. On the one hand, the model confirms a 50% underestimation of SO2 emissions due to satellite swath sampling of the Ozone Monitoring Instrument (OMI), consistent with field studies. The OMI irregular sampling also produces a level of noise that impairs its monitoring capacity during short-term volcanic events. On the other hand, the model reveals a large sensitivity on aerosol composition and Aerosol Optical Depth (AOD) due to choices of both the source function in WRF-Chem and size parameters for sea-salt in FlexAOD, the post-processor used to compute offline the simulated AOD. We then proceed to diagnosing the role of SO2 volcanic emission in the regional aerosol composition. The model shows that both dynamics and cloud properties associated with the South Pacific Convergence Zone (SPCZ) have a large influence on the oxidation of SO2 and on the transport pathways of

  7. Effect of feedback on delaying deterioration in quality of compressions during 2 minutes of continuous chest compressions: a randomized manikin study investigating performance with and without feedback

    Lyngeraa Tobias

    2012-02-01

    Full Text Available Abstract Background Good quality basic life support (BLS improves outcome following cardiac arrest. As BLS performance deteriorates over time we performed a parallel group, superiority study to investigate the effect of feedback on quality of chest compression with the hypothesis that feedback delays deterioration of quality of compressions. Methods Participants attending a national one-day conference on cardiac arrest and CPR in Denmark were randomized to perform single-rescuer BLS with (n = 26 or without verbal and visual feedback (n = 28 on a manikin using a ZOLL AED plus. Data were analyzed using Rescuenet Code Review. Blinding of participants was not possible, but allocation concealment was performed. Primary outcome was the proportion of delivered compressions within target depth compared over a 2-minute period within the groups and between the groups. Secondary outcome was the proportion of delivered compressions within target rate compared over a 2-minute period within the groups and between the groups. Performance variables for 30-second intervals were analyzed and compared. Results 24 (92% and 23 (82% had CPR experience in the group with and without feedback respectively. 14 (54% were CPR instructors in the feedback group and 18 (64% in the group without feedback. Data from 26 and 28 participants were analyzed respectively. Although median values for proportion of delivered compressions within target depth were higher in the feedback group (0-30 s: 54.0%; 30-60 s: 88.0%; 60-90 s: 72.6%; 90-120 s: 87.0%, no significant difference was found when compared to without feedback (0-30 s: 19.6%; 30-60 s: 33.1%; 60-90 s: 44.5%; 90-120 s: 32.7% and no significant deteriorations over time were found within the groups. In the feedback group a significant improvement was found in the proportion of delivered compressions below target depth when the subsequent intervals were compared to the first 30 seconds (0-30 s: 3.9%; 30-60 s: 0.0%; 60-90 s: 0

  8. Visualization and understanding of the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging.

    Vercruysse, Jurgen; Toiviainen, Maunu; Fonteyne, Margot; Helkimo, Niko; Ketolainen, Jarkko; Juuti, Mikko; Delaet, Urbain; Van Assche, Ivo; Remon, Jean Paul; Vervaet, Chris; De Beer, Thomas

    2014-04-01

    Over the last decade, there has been increased interest in the application of twin screw granulation as a continuous wet granulation technique for pharmaceutical drug formulations. However, the mixing of granulation liquid and powder material during the short residence time inside the screw chamber and the atypical particle size distribution (PSD) of granules produced by twin screw granulation is not yet fully understood. Therefore, this study aims at visualizing the granulation liquid mixing and distribution during continuous twin screw granulation using NIR chemical imaging. In first instance, the residence time of material inside the barrel was investigated as function of screw speed and moisture content followed by the visualization of the granulation liquid distribution as function of different formulation and process parameters (liquid feed rate, liquid addition method, screw configuration, moisture content and barrel filling degree). The link between moisture uniformity and granule size distributions was also studied. For residence time analysis, increased screw speed and lower moisture content resulted to a shorter mean residence time and narrower residence time distribution. Besides, the distribution of granulation liquid was more homogenous at higher moisture content and with more kneading zones on the granulator screws. After optimization of the screw configuration, a two-level full factorial experimental design was performed to evaluate the influence of moisture content, screw speed and powder feed rate on the mixing efficiency of the powder and liquid phase. From these results, it was concluded that only increasing the moisture content significantly improved the granulation liquid distribution. This study demonstrates that NIR chemical imaging is a fast and adequate measurement tool for allowing process visualization and hence for providing better process understanding of a continuous twin screw granulation system. Copyright © 2013 Elsevier B.V. All

  9. The relative roles of ANC and EPI in the continuous distribution of LLINs: a qualitative study in four countries.

    Theiss-Nyland, Katherine; Koné, Diakalia; Karema, Corine; Ejersa, Waqo; Webster, Jayne; Lines, Jo

    2017-05-01

    The continuous distribution of long-lasting insecticidal nets (LLINs) for malaria prevention, through the antenatal care (ANC) and the Expanded Programme on Immunizations (EPI), is recommended by the WHO to improve and maintain LLIN coverage. Despite these recommendations, little is known about the relative strengths and weaknesses of the ANC and EPI-based LLIN distribution. This study aimed to explore and compare the roles of the ANC and EPI for LLIN distribution in four African countries. In a qualitative evaluation of continuous distribution through the ANC and EPI, semi-structured, individual and group interviews were conducted in Kenya, Malawi, Mali, and Rwanda. Respondents included national, sub-national, and facility-level health staff, and were selected to capture a range of roles related to malaria, ANC and EPI programmes. Policies, guidelines, and data collection tools were reviewed as a means of triangulation to assess the structure of LLIN distribution, and the methods of data collection and reporting for malaria, ANC and EPI programmes. In the four countries visited, distribution of LLINs was more effectively integrated through ANC than through EPI because of a) stronger linkages and involvement between malaria and reproductive health programmes, as compared to malaria and EPI, and b) more complete programme monitoring for ANC-based distribution, compared to EPI-based distribution. Opportunities for improving the distribution of LLINs through these channels exist, especially in the case of EPI. For both ANC and EPI, integrated distribution of LLINs has the potential to act as an incentive, improving the already strong coverage of both these essential services. The collection and reporting of data on LLINs distributed through the ANC and EPI can provide insight into the performance of LLIN distribution within these programmes. Greater attention to data collection and use, by both the global malaria community, and the integrated programmes, can improve

  10. 131I distribution in mice after continuous exposure to ionizing radiation of 0.39 C/kg

    Mraz, L.; Stollarova, N.

    1982-01-01

    The distribution of 131 I in mice has been investigated under the condition of continuous exposure to daily doses of 0.013 C/kg up to a total dose of 0.39 C/kg. Radioiodine distribution in exposed animals was compared with that in laboratory and field controls at intervals ranging from 0.5 to 24 hours. The group of experimental animals was simultaneously exposed to ionizing radiation and the climatic conditions of the open-air gamma field. Consequently, the metabolic activity of organs decreased during the distribution measurements as is also shown by the low radioiodine level in the thyroid gland. Differences in the distribution in exposed animals as compared with field controls are characteristic of changes caused by ionizing radiation. (author)

  11. Asymptotic Comparison of the Solutions of Linear Time-Delay Systems with Point and Distributed Lags with Those of Their Limiting Equations

    M. De la Sen

    2009-01-01

    Full Text Available This paper investigates the relations between the particular eigensolutions of a limiting functional differential equation of any order, which is the nominal (unperturbed linear autonomous differential equations, and the associate ones of the corresponding perturbed functional differential equation. Both differential equations involve point and distributed delayed dynamics including Volterra class dynamics. The proofs are based on a Perron-type theorem for functional equations so that the comparison is governed by the real part of a dominant zero of the characteristic equation of the nominal differential equation. The obtained results are also applied to investigate the global stability of the perturbed equation based on that of its corresponding limiting equation.

  12. Improving the maximum transmission distance of continuous-variable quantum key distribution with noisy coherent states using a noiseless amplifier

    Wang, Tianyi; Yu, Song; Zhang, Yi-Chen; Gu, Wanyi; Guo, Hong

    2014-01-01

    By employing a nondeterministic noiseless linear amplifier, we propose to increase the maximum transmission distance of continuous-variable quantum key distribution with noisy coherent states. With the covariance matrix transformation, the expression of secret key rate under reverse reconciliation is derived against collective entangling cloner attacks. We show that the noiseless linear amplifier can compensate the detrimental effect of the preparation noise with an enhancement of the maximum transmission distance and the noise resistance. - Highlights: • Noiseless amplifier is applied in noisy coherent state quantum key distribution. • Negative effect of preparation noise is compensated by noiseless amplification. • Maximum transmission distance and noise resistance are both enhanced

  13. Quantum hacking of two-way continuous-variable quantum key distribution using Trojan-horse attack

    Ma Hong-Xin; Bao Wan-Su; Li Hong-Wei; Chou Chun

    2016-01-01

    We present a Trojan-horse attack on the practical two-way continuous-variable quantum key distribution system. Our attack mainly focuses on the imperfection of the practical system that the modulator has a redundancy of modulation pulse-width, which leaves a loophole for the eavesdropper inserting a Trojan-horse pulse. Utilizing the unique characteristics of two-way continuous-variable quantum key distribution that Alice only takes modulation operation on the received mode without any measurement, this attack allows the eavesdropper to render all of the final keys shared between the legitimate parties insecure without being detected. After analyzing the feasibility of the attack, the corresponding countermeasures are put forward. (paper)

  14. Quantum hacking of two-way continuous-variable quantum key distribution using Trojan-horse attack

    Ma, Hong-Xin; Bao, Wan-Su; Li, Hong-Wei; Chou, Chun

    2016-08-01

    We present a Trojan-horse attack on the practical two-way continuous-variable quantum key distribution system. Our attack mainly focuses on the imperfection of the practical system that the modulator has a redundancy of modulation pulse-width, which leaves a loophole for the eavesdropper inserting a Trojan-horse pulse. Utilizing the unique characteristics of two-way continuous-variable quantum key distribution that Alice only takes modulation operation on the received mode without any measurement, this attack allows the eavesdropper to render all of the final keys shared between the legitimate parties insecure without being detected. After analyzing the feasibility of the attack, the corresponding countermeasures are put forward. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002) and the National Natural Science Foundation of China (Grant Nos. 11304397 and 61505261).

  15. A hierarchical model for estimating the spatial distribution and abundance of animals detected by continuous-time recorders.

    Robert M Dorazio

    Full Text Available Several spatial capture-recapture (SCR models have been developed to estimate animal abundance by analyzing the detections of individuals in a spatial array of traps. Most of these models do not use the actual dates and times of detection, even though this information is readily available when using continuous-time recorders, such as microphones or motion-activated cameras. Instead most SCR models either partition the period of trap operation into a set of subjectively chosen discrete intervals and ignore multiple detections of the same individual within each interval, or they simply use the frequency of detections during the period of trap operation and ignore the observed times of detection. Both practices make inefficient use of potentially important information in the data.We developed a hierarchical SCR model to estimate the spatial distribution and abundance of animals detected with continuous-time recorders. Our model includes two kinds of point processes: a spatial process to specify the distribution of latent activity centers of individuals within the region of sampling and a temporal process to specify temporal patterns in the detections of individuals. We illustrated this SCR model by analyzing spatial and temporal patterns evident in the camera-trap detections of tigers living in and around the Nagarahole Tiger Reserve in India. We also conducted a simulation study to examine the performance of our model when analyzing data sets of greater complexity than the tiger data.Our approach provides three important benefits: First, it exploits all of the information in SCR data obtained using continuous-time recorders. Second, it is sufficiently versatile to allow the effects of both space use and behavior of animals to be specified as functions of covariates that vary over space and time. Third, it allows both the spatial distribution and abundance of individuals to be estimated, effectively providing a species distribution model, even in

  16. Factors affecting continued use of ceramic water purifiers distributed to Tsunami-affected Communities in Sri Lanka

    Casanova, Lisa M; Walters, Adam; Naghawatte, Ajith; Sobsey, Mark D

    2012-01-01

    Objectives  There is little information about continued use of point-of-use technologies after disaster relief efforts. After the 2004 tsunami, the Red Cross distributed ceramic water filters in Sri Lanka. This study determined factors associated with filter disuse and evaluate the quality of household drinking water. Methods  A cross-sectional survey of water sources and treatment, filter use and household characteristics was administered by in-person oral interview, and household water qual...

  17. A theoretical framework for convergence and continuous dependence of estimates in inverse problems for distributed parameter systems

    Banks, H. T.; Ito, K.

    1988-01-01

    Numerical techniques for parameter identification in distributed-parameter systems are developed analytically. A general convergence and stability framework (for continuous dependence on observations) is derived for first-order systems on the basis of (1) a weak formulation in terms of sesquilinear forms and (2) the resolvent convergence form of the Trotter-Kato approximation. The extension of this framework to second-order systems is considered.

  18. Vacuum Simulations in High Energy Accelerators and Distribution Properties of Continuous and Discrete Particle Motions

    Aichinger, Ida; Larcher, Gerhard; Kersevan, Roberto

    2017-01-01

    The underlying thesis on mathematical simulation methods in application and theory is structured into three parts. The first part sets up a mathematical model capable of predicting the performance and operation of an accelerator’s vacuum system based on analytical methods. A coupled species-balance equation system describes the distribution of the gas dynamics in an ultra-high vacuum system considering impacts of conductance limitations, beam induced effects (ion-, electron-, and photon-induc...

  19. Impact of continuous training through distributed practice for acquisition of minimally invasive surgical skills.

    Nakata, Bruce Negrello; Cavalini, Worens; Bonin, Eduardo A; Salvalaggio, Paolo R; Loureiro, Marcelo P

    2017-10-01

    Minimally invasive surgery (MIS) requires the mastery of manual skills and a specific training is required. Apart from residencies and fellowships in MIS, other learning opportunities utilize massive training, mainly with use of simulators in short courses. A long-term postgraduate course represents an opportunity to learn through training using distributed practice. The objective of this study is to assess the use of distributed practice for acquisition of basic minimally invasive skills in surgeons who participated in a long-term MIS postgraduate course. A prospective, longitudinal and quantitative study was conducted among surgeons who attended a 1-year postgraduate course of MIS in Brazil, from 2012 to 2014. They were tested through five different exercises in box trainers (peg-transfer, passing, cutting, intracorporeal knot, and suture) in the first (t0), fourth (t1) and last, eighth, (t2) meetings of this course. The time and penalties of each exercise were collected for each participant. Participant skills were assessed based on time and accuracy on a previously tested score. Fifty-seven surgeons (participants) from three consecutive groups participated in this study. There was a significant improvement in scores in all exercises. The average increase in scores between t0 and t2 was 88% for peg-transfer, 174% for passing, 149% for cutting, 130% for intracorporeal knot, and 120% for suture (p < 0.001 for all exercises). Learning through distributed practice is effective and should be integrated into a MIS postgraduate course curriculum for acquisition of core skills.

  20. Security of continuous-variable quantum key distribution: towards a de Finetti theorem for rotation symmetry in phase space

    Leverrier, A; Karpov, E; Cerf, N J; Grangier, P

    2009-01-01

    Proving the unconditional security of quantum key distribution (QKD) is a highly challenging task as one needs to determine the most efficient attack compatible with experimental data. This task is even more demanding for continuous-variable QKD as the Hilbert space where the protocol is described is infinite dimensional. A possible strategy to address this problem is to make an extensive use of the symmetries of the protocol. In this paper, we investigate a rotation symmetry in phase space that is particularly relevant to continuous-variable QKD, and explore the way towards a new quantum de Finetti theorem that would exploit this symmetry and provide a powerful tool to assess the security of continuous-variable protocols. As a first step, a single-party asymptotic version of this quantum de Finetti theorem in phase space is derived.

  1. Continuous Exercise but Not High Intensity Interval Training Improves Fat Distribution in Overweight Adults

    Shelley E. Keating

    2014-01-01

    Full Text Available Objective. The purpose of this study was to assess the effect of high intensity interval training (HIIT versus continuous aerobic exercise training (CONT or placebo (PLA on body composition by randomized controlled design. Methods. Work capacity and body composition (dual-energy X-ray absorptiometry were measured before and after 12 weeks of intervention in 38 previously inactive overweight adults. Results. There was a significant group × time interaction for change in work capacity (P<0.001, which increased significantly in CONT (23.8±3.0% and HIIT (22.3±3.5% but not PLA (3.1±5.0%. There was a near-significant main effect for percentage trunk fat, with trunk fat reducing in CONT by 3.1±1.6% and in PLA by 1.1±0.4%, but not in HIIT (increase of 0.7±1.0% (P=0.07. There was a significant reduction in android fat percentage in CONT (2.7±1.3% and PLA (1.4±0.8% but not HIIT (increase of 0.8±0.7% (P=0.04. Conclusion. These data suggest that HIIT may be advocated as a time-efficient strategy for eliciting comparable fitness benefits to traditional continuous exercise in inactive, overweight adults. However, in this population HIIT does not confer the same benefit to body fat levels as continuous exercise training.

  2. Influence of the catheter-top-position upon the distribution pattern of continuous intra-arterially infused chemotherapeutic agent

    Ichinohe, Hyobu

    1980-01-01

    The whole body scanning showed the distribution pattern of infused drug in continuous intra-arterially infused chemotherapy by using a gamma camera and infused RI (sup(99m)Tc-MAA) from catheter. I measured the whole body scanning counts without shield (A) and with lead shield (B) on ROI and natural back ground counts (BG). Then I calculated the distribution ratio on ROI as following. [(A-B)/(A-BG)] x 100(%). It was easy to find a certain relation between the catheter-top-position and the distribution ratio. As a result of investigating data, there were about 4 catheter-top-positions in aorta. Case by case, we putted the catheter-top in better position and prevented technical side effects and measured roughly total dose on ROI. (author)

  3. Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

    Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

    2018-06-01

    The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

  4. Stress and Friction Distribution around Slab Corner in Continuous Casting Mold with Different Corner Structures

    Yu, Sheng; Long, Mujun; Chen, Huabiao; Chen, Dengfu; Liu, Tao; Duan, Huamei; Cao, Junsheng

    2018-02-01

    The non-uniform friction and thermal stress in the mold are important as causes of the transverse cracks around strand corner. To analyze the stress distribution features around strand corner, a three-dimensional thermo-elastoplastic finite-element mold model with different corner structures (right-angle, big-chamfer, multi-chamfer, and fillet) was established. The temperature field in the mold was indirectly coupled through a three-dimensional fluid flow and heat transfer model. In addition, the non-uniform mold friction stress loaded on the strand surface was calculated through a friction model. The results show that the stress distribution on the shell is similar to the temperature distribution. The stress concentration appears in the strand corner and the lower part of wide face. The friction stress enhances the corner stress around the edge of the air-gap. For chamfered molds, the stress around the corner between the wide face and chamfer face is larger than that between the narrow face and chamfer face. Around the corner region, both the stress peak and the area of the large stress zone of the right-angle strand are the largest, while those of big-chamfered, multi-chamfered, and fillet strands decrease in that order. The stress peak position of the chamfered strands is closer to the mold exit than that of the right-angle strand. Compared with the use of the right-angle mold, the application of chamfered molds is able to reduce the stress concentration around the strand corner.

  5. Continuous solutions to a viral infection model with general incidence rate, discrete state-dependent delay, CTL and antibody immune responses

    Rezunenko, Oleksandr

    2016-01-01

    Roč. 2016, č. 79 (2016), s. 1-15 ISSN 1417-3875 R&D Projects: GA ČR(CZ) GA16-06678S Institutional support: RVO:67985556 Keywords : evolution equations * Lyapunov stability * state-dependent delay * virus infection model Subject RIV: BC - Control Systems Theory Impact factor: 0.926, year: 2016 http://library.utia.cas.cz/separaty/2016/AS/rezunenko-0464066.pdf

  6. Factors Contributing to the Delay in Diagnosis and Continued Transmission of Leprosy in Brazil – An Explorative, Quantitative, Questionnaire Based Study

    Henry, Mary; GalAn, Noêmi; Teasdale, Katherine; Prado, Renata; Amar, Harpreet; Rays, Marina S.; Roberts, Lesley; Siqueira, Pedro; de Wildt, Gilles; Virmond, Marcos; Das, Pranab K.

    2016-01-01

    Background Leprosy is a leading cause of preventable disability worldwide. Delay in diagnosis of patients augments the transmission of infection, and allows progression of disease and more severe disability. Delays in diagnosis greater than ten years have been reported in Brazil. To reduce this delay, it is important to identify factors that hinder patients from presenting to doctors, and those that delay doctors from diagnosing patients once they have presented. This study aimed to explore factors associated with the delayed diagnosis of leprosy in Brazil. Methodology/ Principal Findings This is an exploratory study using a self-constructed questionnaire delivered to patients attending three leprosy referral clinics across three states in Brazil. Data were analysed to determine associations between variables and the time taken for participants to present to the health-service, and between variables and the time taken for doctors to diagnose participants once they had presented. Participants who suspected they had leprosy but feared community isolation were 10 times more likely to wait longer before consulting a doctor for their symptoms (OR 10.37, 95% CI 2.18–49.45, p = 0.003). Participants who thought their symptoms were not serious had a threefold greater chance of waiting longer before consulting than those who did (OR 3.114, 95% CI 1.235–7.856, p = 0.016). Forty-two point six per cent of participants reported initially receiving a diagnosis besides leprosy. These had a three times greater chance of receiving a later diagnosis of leprosy compared to those not misdiagnosed or not given a diagnosis (OR 2.867, 95% CI 1.288–6.384, p = 0.010). Conclusions/ Significance This study implies a need for patient education regarding leprosy symptoms and the reduction of stigma to encourage patients to present. The high rate of misdiagnosis reported suggests a need to increase clinician suspicion of leprosy. Further education regarding disease symptoms in medical

  7. Vacuum Simulations in High Energy Accelerators and Distribution Properties of Continuous and Discrete Particle Motions

    Aichinger, Ida; Kersevan, Roberto

    The underlying thesis on mathematical simulation methods in application and theory is structured into three parts. The first part sets up a mathematical model capable of predicting the performance and operation of an accelerator’s vacuum system based on analytical methods. A coupled species-balance equation system describes the distribution of the gas dynamics in an ultra-high vacuum system considering impacts of conductance limitations, beam induced effects (ion-, electron-, and photon-induced de- sorption), thermal outgassing and sticking probabilities of the chamber materials. A new solving algorithm based on sparse matrix representations, is introduced and presents a closed form solution of the equation system. The model is implemented in a Python environment, named PyVasco, and is supported by a graphical user interface to make it easy available for everyone. A sensitivity analysis, a cross-check with the Test-Particle Monte Carlo simulation program Molflow+ and a comparison of the simulation results t...

  8. Mapping the continuous reciprocal space intensity distribution of X-ray serial crystallography.

    Yefanov, Oleksandr; Gati, Cornelius; Bourenkov, Gleb; Kirian, Richard A; White, Thomas A; Spence, John C H; Chapman, Henry N; Barty, Anton

    2014-07-17

    Serial crystallography using X-ray free-electron lasers enables the collection of tens of thousands of measurements from an equal number of individual crystals, each of which can be smaller than 1 µm in size. This manuscript describes an alternative way of handling diffraction data recorded by serial femtosecond crystallography, by mapping the diffracted intensities into three-dimensional reciprocal space rather than integrating each image in two dimensions as in the classical approach. We call this procedure 'three-dimensional merging'. This procedure retains information about asymmetry in Bragg peaks and diffracted intensities between Bragg spots. This intensity distribution can be used to extract reflection intensities for structure determination and opens up novel avenues for post-refinement, while observed intensity between Bragg peaks and peak asymmetry are of potential use in novel direct phasing strategies.

  9. Periodic solutions of delayed predator-prey model with the Beddington-DeAngelis functional response

    Huo Haifeng [Institute of Applied Mathematics, Lanzhou University of Technology, Lanzhou, Gansu 730050 (China)]. E-mail: hfhuo@lut.cn; Li Wantong [Department of Mathematics, Lanzhou University Lanzhou, Gansu 730000 (China)]. E-mail: wtli@lzu.edu.cn; Nieto, Juan J. [Departamento de Analisis Matematico, Facultad de Matematicas, Universidad de Santiago de Compostela 15782 (Spain)]. E-mail: amnieto@usc.es

    2007-07-15

    By using the continuation theorem based on Gaines and Mawhin's coincidence degree, sufficient and realistic conditions are obtained for the global existence of positive periodic solutions for a delayed predator-prey model with the Beddington-DeAngelis functional response. Our results are applicable to state dependent and distributed delays.

  10. Mentalizing regions represent distributed, continuous, and abstract dimensions of others' beliefs.

    Koster-Hale, Jorie; Richardson, Hilary; Velez, Natalia; Asaba, Mika; Young, Liane; Saxe, Rebecca

    2017-11-01

    The human capacity to reason about others' minds includes making causal inferences about intentions, beliefs, values, and goals. Previous fMRI research has suggested that a network of brain regions, including bilateral temporo-parietal junction (TPJ), superior temporal sulcus (STS), and medial prefrontal-cortex (MPFC), are reliably recruited for mental state reasoning. Here, in two fMRI experiments, we investigate the representational content of these regions. Building on existing computational and neural evidence, we hypothesized that social brain regions contain at least two functionally and spatially distinct components: one that represents information related to others' motivations and values, and another that represents information about others' beliefs and knowledge. Using multi-voxel pattern analysis, we find evidence that motivational versus epistemic features are independently represented by theory of mind (ToM) regions: RTPJ contains information about the justification of the belief, bilateral TPJ represents the modality of the source of knowledge, and VMPFC represents the valence of the resulting emotion. These representations are found only in regions implicated in social cognition and predict behavioral responses at the level of single items. We argue that cortical regions implicated in mental state inference contain complementary, but distinct, representations of epistemic and motivational features of others' beliefs, and that, mirroring the processes observed in sensory systems, social stimuli are represented in distinct and distributed formats across the human brain. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Delay-dependent stability of neural networks of neutral type with time delay in the leakage term

    Li, Xiaodi; Cao, Jinde

    2010-01-01

    This paper studies the global asymptotic stability of neural networks of neutral type with mixed delays. The mixed delays include constant delay in the leakage term (i.e. 'leakage delay'), time-varying delays and continuously distributed delays. Based on the topological degree theory, Lyapunov method and linear matrix inequality (LMI) approach, some sufficient conditions are derived ensuring the existence, uniqueness and global asymptotic stability of the equilibrium point, which are dependent on both the discrete and distributed time delays. These conditions are expressed in terms of LMI and can be easily checked by the MATLAB LMI toolbox. Even if there is no leakage delay, the obtained results are less restrictive than some recent works. It can be applied to neural networks of neutral type with activation functions without assuming their boundedness, monotonicity or differentiability. Moreover, the differentiability of the time-varying delay in the non-neutral term is removed. Finally, two numerical examples are given to show the effectiveness of the proposed method

  12. An improved two-way continuous-variable quantum key distribution protocol with added noise in homodyne detection

    Sun Maozhu; Peng Xiang; Guo Hong

    2013-01-01

    We propose an improved two-way continuous-variable quantum key distribution (CV QKD) protocol by adding proper random noise on the receiver’s homodyne detection, the security of which is analysed against general collective attacks. The simulation result under the collective entangling cloner attack indicates that despite the correlation between two-way channels decreasing the secret key rate relative to the uncorrelated channels slightly, the performance of the two-way protocol is still far beyond that of the one-way protocols. Importantly, the added noise in detection is beneficial for the secret key rate and the tolerable excess noise of this two-way protocol. With the reasonable reconciliation efficiency of 90%, the two-way CV QKD with added noise allows the distribution of secret keys over 60 km fibre distance. (paper)

  13. Delayed fission

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  14. Factors affecting continued use of ceramic water purifiers distributed to tsunami-affected communities in Sri Lanka.

    Casanova, Lisa M; Walters, Adam; Naghawatte, Ajith; Sobsey, Mark D

    2012-11-01

    There is little information about continued use of point-of-use technologies after disaster relief efforts. After the 2004 tsunami, the Red Cross distributed ceramic water filters in Sri Lanka. This study determined factors associated with filter disuse and evaluate the quality of household drinking water. A cross-sectional survey of water sources and treatment, filter use and household characteristics was administered by in-person oral interview, and household water quality was tested. Multivariable logistic regression was used to model probability of filter non-use. At the time of survey, 24% of households (107/452) did not use filters; the most common reason given was breakage (42%). The most common household water sources were taps and wells. Wells were used by 45% of filter users and 28% of non-users. Of households with taps, 75% had source water Escherichia coli in the lowest World Health Organisation risk category (<1/100 ml), vs. only 30% of households reporting wells did. Tap households were approximately four times more likely to discontinue filter use than well households. After 2 years, 24% of households were non-users. The main factors were breakage and household water source; households with taps were more likely to stop use than households with wells. Tap water users also had higher-quality source water, suggesting that disuse is not necessarily negative and monitoring of water quality can aid decision-making about continued use. To promote continued use, disaster recovery filter distribution efforts must be joined with capacity building for long-term water monitoring, supply chains and local production. © 2012 Blackwell Publishing Ltd.

  15. Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique.

    Pant, H J; Sharma, V K; Shenoy, K T; Sreenivas, T

    2015-03-01

    An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40-60MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Measurements of liquid phase residence time distributions in a pilot-scale continuous leaching reactor using radiotracer technique

    Pant, H.J.; Sharma, V.K.; Shenoy, K.T.; Sreenivas, T.

    2015-01-01

    An alkaline based continuous leaching process is commonly used for extraction of uranium from uranium ore. The reactor in which the leaching process is carried out is called a continuous leaching reactor (CLR) and is expected to behave as a continuously stirred tank reactor (CSTR) for the liquid phase. A pilot-scale CLR used in a Technology Demonstration Pilot Plant (TDPP) was designed, installed and operated; and thus needed to be tested for its hydrodynamic behavior. A radiotracer investigation was carried out in the CLR for measurement of residence time distribution (RTD) of liquid phase with specific objectives to characterize the flow behavior of the reactor and validate its design. Bromine-82 as ammonium bromide was used as a radiotracer and about 40–60 MBq activity was used in each run. The measured RTD curves were treated and mean residence times were determined and simulated using a tanks-in-series model. The result of simulation indicated no flow abnormality and the reactor behaved as an ideal CSTR for the range of the operating conditions used in the investigation. - Highlights: • Radiotracer technique was applied for evaluation of design of a pilot-scale continuous leaching reactor. • Mean residence time and dead volume were estimated. Dead volume was found to be ranging from 4% to 15% at different operating conditions. • Tank-in-series model was used to simulate the measured RTD data and was found suitable to describe the flow in the reactor. • No flow abnormality was found and the reactor behaved as a well-mixed system. The design of the reactor was validated

  17. Delayed-enhancement MRI of apical hypertrophic cardiomyopathy: assessment of the intramural distribution and comparison with clinical symptoms, ventricular arrhythmias, and cine MRI

    Amano, Yasuo; Fukushima, Yoshimitsu; Kumita, Shinichiro; Takayama, Morimasa; Kitamura, Mitsunobu

    2011-01-01

    Background: Hypertrophic cardiomyopathy (HCM) is reported to show patchy midwall myocardial hyper enhancement on delayed-enhancement magnetic resonance imaging (DE-MRI). The intramural distribution of myocardial hyper enhancement and its correlation with clinical symptoms, ventricular arrhythmias, and cardiac function have not been described for symptomatic apical HCM. Purpose: To evaluate the features and significance of myocardial hyper enhancement on DE-MRI in symptomatic apical HCM. Material and Methods: Thirteen patients with symptomatic apical HCM and their 65 apical segments were investigated. Myocardial hyper enhancement and regional and global functional parameters were determined with MRI. We investigated the intramural distribution and frequencies of this myocardial hyper enhancement and compared them with the patients' clinical symptoms, the presence of ventricular arrhythmias, and cine MRI. Results: Eight (61.5%) patients with symptomatic apical HCM displayed apical myocardial hyper enhancement, and 22 (33.8%) of the 65 apical segments examined showed myocardial hyper enhancement. Of the myocardial hyper enhancement observed, 81.8% showed a subendocardial pattern.The Hyperenhanced apical myocardium had a lower percentage of systolic myocardial thickening, and was associated with serious symptoms (e.g. syncope) and ventricular arrhythmias. Conclusion: Patients with symptomatic apical HCM showed myocardial hyper enhancement involving the subendocardial layer, which might be related to regional systolic dysfunction, serious clinical symptoms, and ventricular arrhythmias

  18. Asymptotic Delay Analysis for Cross-Layer Delay-Based Routing in Ad Hoc Networks

    Philippe Jacquet

    2007-01-01

    Full Text Available This paper addresses the problem of the evaluation of the delay distribution via analytical means in IEEE 802.11 wireless ad hoc networks. We show that the asymptotic delay distribution can be expressed as a power law. Based on the latter result, we present a cross-layer delay estimation protocol and we derive new delay-distribution-based routing algorithms, which are well adapted to the QoS requirements of real-time multimedia applications. In fact, multimedia services are not sensitive to average delays, but rather to the asymptotic delay distributions. Indeed, video streaming applications drop frames when they are received beyond a delay threshold, determined by the buffer size. Although delay-distribution-based routing is an NP-hard problem, we show that it can be solved in polynomial time when the delay threshold is large, because of the asymptotic power law distribution of the link delays.

  19. Mean square exponential stability of stochastic delayed Hopfield neural networks

    Wan Li; Sun Jianhua

    2005-01-01

    Stochastic effects to the stability property of Hopfield neural networks (HNN) with discrete and continuously distributed delay are considered. By using the method of variation parameter, inequality technique and stochastic analysis, the sufficient conditions to guarantee the mean square exponential stability of an equilibrium solution are given. Two examples are also given to demonstrate our results

  20. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    Meng, Yiqing; Lucas, Gary P

    2017-01-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas–water and oil–gas–water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the

  1. Imaging water velocity and volume fraction distributions in water continuous multiphase flows using inductive flow tomography and electrical resistance tomography

    Meng, Yiqing; Lucas, Gary P.

    2017-05-01

    This paper presents the design and implementation of an inductive flow tomography (IFT) system, employing a multi-electrode electromagnetic flow meter (EMFM) and novel reconstruction techniques, for measuring the local water velocity distribution in water continuous single and multiphase flows. A series of experiments were carried out in vertical-upward and upward-inclined single phase water flows and ‘water continuous’ gas-water and oil-gas-water flows in which the velocity profiles ranged from axisymmetric (single phase and vertical-upward multiphase flows) to highly asymmetric (upward-inclined multiphase flows). Using potential difference measurements obtained from the electrode array of the EMFM, local axial velocity distributions of the continuous water phase were reconstructed using two different IFT reconstruction algorithms denoted RT#1, which assumes that the overall water velocity profile comprises the sum of a series of polynomial velocity components, and RT#2, which is similar to RT#1 but which assumes that the zero’th order velocity component may be replaced by an axisymmetric ‘power law’ velocity distribution. During each experiment, measurement of the local water volume fraction distribution was also made using the well-established technique of electrical resistance tomography (ERT). By integrating the product of the local axial water velocity and the local water volume fraction in the cross section an estimate of the water volumetric flow rate was made which was compared with a reference measurement of the water volumetric flow rate. In vertical upward flows RT#2 was found to give rise to water velocity profiles which are consistent with the previous literature although the profiles obtained in the multiphase flows had relatively higher central velocity peaks than was observed for the single phase profiles. This observation was almost certainly a result of the transfer of axial momentum from the less dense dispersed phases to the water

  2. Free vibration analysis of a robotic fish based on a continuous and non-uniform flexible backbone with distributed masses

    Coral, W.; Rossi, C.; Curet, O. M.

    2015-12-01

    This paper presents a Differential Quadrature Element Method for free transverse vibration of a robotic fish based on a continuous and non-uniform flexible backbone with distributed masses (fish ribs). The proposed method is based on the theory of a Timoshenko cantilever beam. The effects of the masses (number, magnitude and position) on the value of natural frequencies are investigated. Governing equations, compatibility and boundary conditions are formulated according to the Differential Quadrature rules. The convergence, efficiency and accuracy are compared to other analytical solution proposed in the literature. Moreover, the proposed method has been validate against the physical prototype of a flexible fish backbone. The main advantages of this method, compared to the exact solutions available in the literature are twofold: first, smaller computational cost and second, it allows analysing the free vibration in beams whose section is an arbitrary function, which is normally difficult or even impossible with other analytical methods.

  3. Practical performance of real-time shot-noise measurement in continuous-variable quantum key distribution

    Wang, Tao; Huang, Peng; Zhou, Yingming; Liu, Weiqi; Zeng, Guihua

    2018-01-01

    In a practical continuous-variable quantum key distribution (CVQKD) system, real-time shot-noise measurement (RTSNM) is an essential procedure for preventing the eavesdropper exploiting the practical security loopholes. However, the performance of this procedure itself is not analyzed under the real-world condition. Therefore, we indicate the RTSNM practical performance and investigate its effects on the CVQKD system. In particular, due to the finite-size effect, the shot-noise measurement at the receiver's side may decrease the precision of parameter estimation and consequently result in a tight security bound. To mitigate that, we optimize the block size for RTSNM under the ensemble size limitation to maximize the secure key rate. Moreover, the effect of finite dynamics of amplitude modulator in this scheme is studied and its mitigation method is also proposed. Our work indicates the practical performance of RTSNM and provides the real secret key rate under it.

  4. Security analysis of orthogonal-frequency-division-multiplexing-based continuous-variable quantum key distribution with imperfect modulation

    Zhang, Hang; Mao, Yu; Huang, Duan; Li, Jiawei; Zhang, Ling; Guo, Ying

    2018-05-01

    We introduce a reliable scheme for continuous-variable quantum key distribution (CV-QKD) by using orthogonal frequency division multiplexing (OFDM). As a spectrally efficient multiplexing technique, OFDM allows a large number of closely spaced orthogonal subcarrier signals used to carry data on several parallel data streams or channels. We place emphasis on modulator impairments which would inevitably arise in the OFDM system and analyze how these impairments affect the OFDM-based CV-QKD system. Moreover, we also evaluate the security in the asymptotic limit and the Pirandola-Laurenza-Ottaviani-Banchi upper bound. Results indicate that although the emergence of imperfect modulation would bring about a slight decrease in the secret key bit rate of each subcarrier, the multiplexing technique combined with CV-QKD results in a desirable improvement on the total secret key bit rate which can raise the numerical value about an order of magnitude.

  5. Recurrent neural network approach to quantum signal: coherent state restoration for continuous-variable quantum key distribution

    Lu, Weizhao; Huang, Chunhui; Hou, Kun; Shi, Liting; Zhao, Huihui; Li, Zhengmei; Qiu, Jianfeng

    2018-05-01

    In continuous-variable quantum key distribution (CV-QKD), weak signal carrying information transmits from Alice to Bob; during this process it is easily influenced by unknown noise which reduces signal-to-noise ratio, and strongly impacts reliability and stability of the communication. Recurrent quantum neural network (RQNN) is an artificial neural network model which can perform stochastic filtering without any prior knowledge of the signal and noise. In this paper, a modified RQNN algorithm with expectation maximization algorithm is proposed to process the signal in CV-QKD, which follows the basic rule of quantum mechanics. After RQNN, noise power decreases about 15 dBm, coherent signal recognition rate of RQNN is 96%, quantum bit error rate (QBER) drops to 4%, which is 6.9% lower than original QBER, and channel capacity is notably enlarged.

  6. Measurement of residence time distribution of liquid phase in an industrial-scale continuous pulp digester using radiotracer technique.

    Sheoran, Meenakshi; Goswami, Sunil; Pant, Harish J; Biswal, Jayashree; Sharma, Vijay K; Chandra, Avinash; Bhunia, Haripada; Bajpai, Pramod K; Rao, S Madhukar; Dash, A

    2016-05-01

    A series of radiotracer experiments was carried out to measure residence time distribution (RTD) of liquid phase (alkali) in an industrial-scale continuous pulp digester in a paper industry in India. Bromine-82 as ammonium bromide was used as a radiotracer. Experiments were carried out at different biomass and white liquor flow rates. The measured RTD data were treated and mean residence times in individual digester tubes as well in the whole digester were determined. The RTD was also analyzed to identify flow abnormalities and investigate flow dynamics of the liquid phase in the pulp digester. Flow channeling was observed in the first section (tube 1) of the digester. Both axial dispersion and tanks-in-series with backmixing models preceded with a plug flow component were used to simulate the measured RTD and quantify the degree of axial mixing. Based on the study, optimum conditions for operating the digester were proposed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. An approach for characterizing the distribution of shrubland ecosystem components as continuous fields as part of NLCD

    Xian, George Z.; Homer, Collin G.; Meyer, Debbie; Granneman, Brian J.

    2013-01-01

    Characterizing and quantifying distributions of shrubland ecosystem components is one of the major challenges for monitoring shrubland vegetation cover change across the United States. A new approach has been developed to quantify shrubland components as fractional products within National Land Cover Database (NLCD). This approach uses remote sensing data and regression tree models to estimate the fractional cover of shrubland ecosystem components. The approach consists of three major steps: field data collection, high resolution estimates of shrubland ecosystem components using WorldView-2 imagery, and coarse resolution estimates of these components across larger areas using Landsat imagery. This research seeks to explore this method to quantify shrubland ecosystem components as continuous fields in regions that contain wide-ranging shrubland ecosystems. Fractional cover of four shrubland ecosystem components, including bare ground, herbaceous, litter, and shrub, as well as shrub heights, were delineated in three ecological regions in Arizona, Florida, and Texas. Results show that estimates for most components have relatively small normalized root mean square errors and significant correlations with validation data in both Arizona and Texas. The distribution patterns of shrub height also show relatively high accuracies in these two areas. The fractional cover estimates of shrubland components, except for litter, are not well represented in the Florida site. The research results suggest that this method provides good potential to effectively characterize shrubland ecosystem conditions over perennial shrubland although it is less effective in transitional shrubland. The fractional cover of shrub components as continuous elements could offer valuable information to quantify biomass and help improve thematic land cover classification in arid and semiarid areas.

  8. Depth distribution of abiotic drivers of N mineralization and methane emission from a continuously and intermittently flooded Bangladeshi paddy soil

    Akter, Masuda; Kader, Md. Abdul; Pierreux, Sofie; Boeckx, Pascal; Kamal, Ahammad Mostafa; Sleutel, Steven

    2016-04-01

    Water-saving irrigation such as AWD may significantly alter depth profiles of moisture content, pH, Eh and soil microbial activity. Modelling the effect of irrigation management on soil N mineralization, therefore requires detailed insight into depth distribution of these variables and dissolved organic carbon (DOC), and evolution of electron acceptors. We set up a field experiment at Bangladesh Agricultural University from January to May' 2015. The cultivated rice variety (BRRI dhan28) was grown under continuous flooding (CF) and alternate wetting and drying (AWD) management, with 120 kg N ha-1(N120) or without (N0)N fertilizer application. We measured soil mineral N and plant N uptake to evaluate N mineralization. CH4 emissions were monitored with timely gas sample collection and GC-analysis. Soil Eh at four depths and temperature at two depths were monitored continuously by Eh/T°-probes connected to a HYPNOS III data logger (MVH, The Netherlands). Simultaneously, soil solution from three depths were sampled with rhizon samplers to track DOC, Fe and Mn in solution. Over the growing season soil and air temperature increased by 8°C, and soil pH stayed near neutral (6.7 to 7.8). In all depths of AWD and CF, Eh dropped sharply to methanic conditions within 21 days after transplanting (DAT). Low redox-potential continued until 77DAT in all cases, except in the puddle layers under AWD, where redox raised to -200mV during drainage. Fe and Mn in soil solution increased gradually over the growing season, indicating continued reductive dissolution of Fe and Mn (hydro-)oxides. DOC increased continuously as well in all depths. Besides to release of DOC bound to pedogenic oxides upon their reductive dissolution, higher plant and soil microbial activity with increasing soil temperature (till 28°C) through the growing season explains the increasing DOC levels. Increasing methanogenic activity as indicated by the high CH4 emissions at 70-84DAT under both CF and AWD is

  9. Distributed computing strategies for processing of FT-ICR MS imaging datasets for continuous mode data visualization

    Smith, Donald F.; Schulz, Carl; Konijnenburg, Marco; Kilic, Mehmet; Heeren, Ronald M.

    2015-03-01

    High-resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry imaging enables the spatial mapping and identification of biomolecules from complex surfaces. The need for long time-domain transients, and thus large raw file sizes, results in a large amount of raw data (“big data”) that must be processed efficiently and rapidly. This can be compounded by largearea imaging and/or high spatial resolution imaging. For FT-ICR, data processing and data reduction must not compromise the high mass resolution afforded by the mass spectrometer. The continuous mode “Mosaic Datacube” approach allows high mass resolution visualization (0.001 Da) of mass spectrometry imaging data, but requires additional processing as compared to featurebased processing. We describe the use of distributed computing for processing of FT-ICR MS imaging datasets with generation of continuous mode Mosaic Datacubes for high mass resolution visualization. An eight-fold improvement in processing time is demonstrated using a Dutch nationally available cloud service.

  10. Continuous-wave dual-wavelength operation of a distributed feedback laser diode with an external cavity using a volume Bragg grating

    Zheng, Yujin; Sekine, Takashi; Kurita, Takashi; Kato, Yoshinori; Kawashima, Toshiyuki

    2018-03-01

    We demonstrate continuous-wave dual-wavelength operation of a broad-area distributed feedback (DFB) laser diode with a single external-cavity configuration. This high-power DFB laser has a narrow bandwidth (current and temperature ranges.

  11. Delayed Ejaculation

    ... cases, it is due to a combination of physical and psychological concerns. Psychological causes of delayed ejaculation include: Depression, anxiety or other mental health conditions Relationship problems due to stress, poor communication ...

  12. Delayed growth

    ... Slow rate of growth; Retarded growth and development; Growth delay Images Toddler development References Cooke DW, Divall SA, Radovick S. Normal and aberrant growth in children. In: Melmed S, Polonsky KS, Larsen PR, ...

  13. Inferring Population Genetic Structure in Widely and Continuously Distributed Carnivores: The Stone Marten (Martes foina) as a Case Study.

    Vergara, María; Basto, Mafalda P; Madeira, María José; Gómez-Moliner, Benjamín J; Santos-Reis, Margarida; Fernandes, Carlos; Ruiz-González, Aritz

    2015-01-01

    The stone marten is a widely distributed mustelid in the Palaearctic region that exhibits variable habitat preferences in different parts of its range. The species is a Holocene immigrant from southwest Asia which, according to fossil remains, followed the expansion of the Neolithic farming cultures into Europe and possibly colonized the Iberian Peninsula during the Early Neolithic (ca. 7,000 years BP). However, the population genetic structure and historical biogeography of this generalist carnivore remains essentially unknown. In this study we have combined mitochondrial DNA (mtDNA) sequencing (621 bp) and microsatellite genotyping (23 polymorphic markers) to infer the population genetic structure of the stone marten within the Iberian Peninsula. The mtDNA data revealed low haplotype and nucleotide diversities and a lack of phylogeographic structure, most likely due to a recent colonization of the Iberian Peninsula by a few mtDNA lineages during the Early Neolithic. The microsatellite data set was analysed with a) spatial and non-spatial Bayesian individual-based clustering (IBC) approaches (STRUCTURE, TESS, BAPS and GENELAND), and b) multivariate methods [discriminant analysis of principal components (DAPC) and spatial principal component analysis (sPCA)]. Additionally, because isolation by distance (IBD) is a common spatial genetic pattern in mobile and continuously distributed species and it may represent a challenge to the performance of the above methods, the microsatellite data set was tested for its presence. Overall, the genetic structure of the stone marten in the Iberian Peninsula was characterized by a NE-SW spatial pattern of IBD, and this may explain the observed disagreement between clustering solutions obtained by the different IBC methods. However, there was significant indication for contemporary genetic structuring, albeit weak, into at least three different subpopulations. The detected subdivision could be attributed to the influence of the

  14. Inferring Population Genetic Structure in Widely and Continuously Distributed Carnivores: The Stone Marten (Martes foina as a Case Study.

    María Vergara

    Full Text Available The stone marten is a widely distributed mustelid in the Palaearctic region that exhibits variable habitat preferences in different parts of its range. The species is a Holocene immigrant from southwest Asia which, according to fossil remains, followed the expansion of the Neolithic farming cultures into Europe and possibly colonized the Iberian Peninsula during the Early Neolithic (ca. 7,000 years BP. However, the population genetic structure and historical biogeography of this generalist carnivore remains essentially unknown. In this study we have combined mitochondrial DNA (mtDNA sequencing (621 bp and microsatellite genotyping (23 polymorphic markers to infer the population genetic structure of the stone marten within the Iberian Peninsula. The mtDNA data revealed low haplotype and nucleotide diversities and a lack of phylogeographic structure, most likely due to a recent colonization of the Iberian Peninsula by a few mtDNA lineages during the Early Neolithic. The microsatellite data set was analysed with a spatial and non-spatial Bayesian individual-based clustering (IBC approaches (STRUCTURE, TESS, BAPS and GENELAND, and b multivariate methods [discriminant analysis of principal components (DAPC and spatial principal component analysis (sPCA]. Additionally, because isolation by distance (IBD is a common spatial genetic pattern in mobile and continuously distributed species and it may represent a challenge to the performance of the above methods, the microsatellite data set was tested for its presence. Overall, the genetic structure of the stone marten in the Iberian Peninsula was characterized by a NE-SW spatial pattern of IBD, and this may explain the observed disagreement between clustering solutions obtained by the different IBC methods. However, there was significant indication for contemporary genetic structuring, albeit weak, into at least three different subpopulations. The detected subdivision could be attributed to the influence

  15. The Mediating Roles of Internal Context Variables in the Relationship between Distributed Leadership Perceptions and Continuous Change Behaviours of Public School Teachers

    Kondakci, Yasar; Zayim, Merve; Beycioglu, Kadir; Sincar, Mehmet; Ugurlu, Celal T

    2016-01-01

    This study aims at building a theoretical base for continuous change in education and using this base to test the mediating roles of two key contextual variables, knowledge sharing and trust, in the relationship between the distributed leadership perceptions and continuous change behaviours of teachers. Data were collected from 687 public school…

  16. Molecular weight​/branching distribution modeling of low-​density-​polyethylene accounting for topological scission and combination termination in continuous stirred tank reactor

    Yaghini, N.; Iedema, P.D.

    2014-01-01

    We present a comprehensive model to predict the molecular weight distribution (MWD),(1) and branching distribution of low-density polyethylene (IdPE),(2) for free radical polymerization system in a continuous stirred tank reactor (CSTR).(3) The model accounts for branching, by branching moment or

  17. Heteroresistance to Fluconazole Is a Continuously Distributed Phenotype among Candida glabrata Clinical Strains Associated with In Vivo Persistence

    Ronen Ben-Ami

    2016-08-01

    Full Text Available Candida glabrata causes persistent infections in patients treated with fluconazole and often acquires resistance following exposure to the drug. Here we found that clinical strains of C. glabrata exhibit cell-to-cell variation in drug response (heteroresistance. We used population analysis profiling (PAP to assess fluconazole heteroresistance (FLCHR and to ask if it is a binary trait or a continuous phenotype. Thirty (57.6% of 52 fluconazole-sensitive clinical C. glabrata isolates met accepted dichotomous criteria for FLCHR. However, quantitative grading of FLCHR by using the area under the PAP curve (AUC revealed a continuous distribution across a wide range of values, suggesting that all isolates exhibit some degree of heteroresistance. The AUC correlated with rhodamine 6G efflux and was associated with upregulation of the CDR1 and PDH1 genes, encoding ATP-binding cassette (ABC transmembrane transporters, implying that HetR populations exhibit higher levels of drug efflux. Highly FLCHRC. glabrata was recovered more frequently than nonheteroresistant C. glabrata from hematogenously infected immunocompetent mice following treatment with high-dose fluconazole (45.8% versus 15%, P = 0.029. Phylogenetic analysis revealed some phenotypic clustering but also variations in FLCHR within clonal groups, suggesting both genetic and epigenetic determinants of heteroresistance. Collectively, these results establish heteroresistance to fluconazole as a graded phenotype associated with ABC transporter upregulation and fluconazole efflux. Heteroresistance may explain the propensity of C. glabrata for persistent infection and the emergence of breakthrough resistance to fluconazole.

  18. Measurement of residence time distribution of liquid phase in an industrial-scale continuous pulp digester using radiotracer technique

    Sheoran, Meenakshi; Goswami, Sunil; Pant, Harish J.; Biswal, Jayashree; Sharma, Vijay K.; Chandra, Avinash; Bhunia, Haripada; Bajpai, Pramod K.; Rao, S. Madhukar; Dash, A.

    2016-01-01

    A series of radiotracer experiments was carried out to measure residence time distribution (RTD) of liquid phase (alkali) in an industrial-scale continuous pulp digester in a paper industry in India. Bromine-82 as ammonium bromide was used as a radiotracer. Experiments were carried out at different biomass and white liquor flow rates. The measured RTD data were treated and mean residence times in individual digester tubes as well in the whole digester were determined. The RTD was also analyzed to identify flow abnormalities and investigate flow dynamics of the liquid phase in the pulp digester. Flow channeling was observed in the first section (tube 1) of the digester. Both axial dispersion and tanks-in-series with backmixing models preceded with a plug flow component were used to simulate the measured RTD and quantify the degree of axial mixing. Based on the study, optimum conditions for operating the digester were proposed. - Highlights: • Radiotracer experiments were conducted to measure RTD of liquid phase in a pulp digester • Mean residence times of white liquor were measured • Axial dispersion and tanks-in-series models were used to investigate flow patterns • Parallel flow paths were observed in first section of the digester • Optimized flow rates of biomass and liquor were obtained

  19. Developmental delay

    Nutrition support is essential for the care of the child with developmental delay. After a thorough evaluation, an individualized intervention plan that accounts for the child’s nutrition status, feeding ability, and medical condition may be determined. Nutrition assessments may be performed at leas...

  20. THE MULTI-EPOCH NEARBY CLUSTER SURVEY: TYPE Ia SUPERNOVA RATE MEASUREMENT IN z ∼ 0.1 CLUSTERS AND THE LATE-TIME DELAY TIME DISTRIBUTION

    Sand, David J.; Graham, Melissa L.; Bildfell, Chris; Pritchet, Chris; Zaritsky, Dennis; Just, Dennis W.; Herbert-Fort, Stéphane; Hoekstra, Henk; Sivanandam, Suresh; Foley, Ryan J.; Mahdavi, Andisheh

    2012-01-01

    We describe the Multi-Epoch Nearby Cluster Survey, designed to measure the cluster Type Ia supernova (SN Ia) rate in a sample of 57 X-ray selected galaxy clusters, with redshifts of 0.05 200 (1 Mpc) of 0.042 +0.012 –0.010 +0.010 –0.008 SNuM (0.049 +0.016 –0.014 +0.005 –0.004 SNuM) and an SN Ia rate within red-sequence galaxies of 0.041 +0.015 –0.015 +0.005 –0.010 SNuM (0.041 +0.019 –0.015 +0.005 –0.004 SNuM). The red-sequence SN Ia rate is consistent with published rates in early-type/elliptical galaxies in the 'field'. Using our red-sequence SN Ia rate, and other cluster SN measurements in early-type galaxies up to z ∼ 1, we derive the late-time (>2 Gyr) delay time distribution (DTD) of SN Ia assuming a cluster early-type galaxy star formation epoch of z f = 3. Assuming a power-law form for the DTD, Ψ(t)∝t s , we find s = –1.62 ± 0.54. This result is consistent with predictions for the double degenerate SN Ia progenitor scenario (s ∼ –1) and is also in line with recent calculations for the double detonation explosion mechanism (s ∼ –2). The most recent calculations of the single degenerate scenario DTD predicts an order-of-magnitude drop-off in SN Ia rate ∼6-7 Gyr after stellar formation, and the observed cluster rates cannot rule this out.

  1. Cell-size distribution and scaling in a one-dimensional Kolmogorov-Johnson-Mehl-Avrami lattice model with continuous nucleation

    Néda, Zoltán; Járai-Szabó, Ferenc; Boda, Szilárd

    2017-10-01

    The Kolmogorov-Johnson-Mehl-Avrami (KJMA) growth model is considered on a one-dimensional (1D) lattice. Cells can grow with constant speed and continuously nucleate on the empty sites. We offer an alternative mean-field-like approach for describing theoretically the dynamics and derive an analytical cell-size distribution function. Our method reproduces the same scaling laws as the KJMA theory and has the advantage that it leads to a simple closed form for the cell-size distribution function. It is shown that a Weibull distribution is appropriate for describing the final cell-size distribution. The results are discussed in comparison with Monte Carlo simulation data.

  2. Seasonal variability of aerosol concentration and size distribution in Cape Verde using a continuous aerosol optical spectrometer

    Casimiro Adrião Pio

    2014-05-01

    Full Text Available One year of, almost continuous, measurements of aerosol optical properties and chemical composition were performed at the outskirts of Praia, Santiago Island, Cape Verde, within the framework of CV-DUST (Atmospheric aerosol in Cape Verde region: seasonal evaluation of composition, sources and transport research project, during 2011. This article reports the aerosol number and mass concentration measurements using a GRIMM Optical Aerosol Spectrometer that provides number size discrimination into 31 size ranges from 0.25 to 32 µm. Time series of 5 min average PM10 concentrations revealed peak values higher than 1000 µg.m-3 during winter dust storm events originating over Northern Africa. The 24 hours average concentrations exceeded the World Health Organization (WHO guidelines for PM2.5 and PM10 in 20% and 30% of the 2001 days, respectively. Annual average mass concentrations (±standard deviation for PM1, PM2.5 and PM10 were 5±5, 19±21 and 48±64 µg.m-3, respectively. The annual PM2.5 and PM10 values were also above the limits prescribed by the WHO (10 and 20 µg.m-3, respectively. The aerosol mass size distribution revealed two main modes for particles smaller than 10 µm: a fine mode (0.7-0.8 µm, which possibly results of gas to particle conversion processes; and a coarse mode with maxima at 3-4 µm, which is associated with desert dust and sea salt sources. Within the coarse mode two sub-modes with maxima at 5-6 µm and 10-12 µm were frequently present.

  3. THE MULTI-EPOCH NEARBY CLUSTER SURVEY: TYPE Ia SUPERNOVA RATE MEASUREMENT IN z {approx} 0.1 CLUSTERS AND THE LATE-TIME DELAY TIME DISTRIBUTION

    Sand, David J.; Graham, Melissa L. [Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States); Bildfell, Chris; Pritchet, Chris [Department of Physics and Astronomy, University of Victoria, P.O. Box 3055, STN CSC, Victoria BC V8W 3P6 (Canada); Zaritsky, Dennis; Just, Dennis W.; Herbert-Fort, Stephane [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Hoekstra, Henk [Leiden Observatory, Leiden University, Niels Bohrweg 2, NL-2333 CA Leiden (Netherlands); Sivanandam, Suresh [Dunlap Institute for Astronomy and Astrophysics, 50 St. George Street, Toronto, ON M5S 3H4 (Canada); Foley, Ryan J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Mahdavi, Andisheh, E-mail: dsand@lcogt.net [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States)

    2012-02-20

    We describe the Multi-Epoch Nearby Cluster Survey, designed to measure the cluster Type Ia supernova (SN Ia) rate in a sample of 57 X-ray selected galaxy clusters, with redshifts of 0.05 < z < 0.15. Utilizing our real-time analysis pipeline, we spectroscopically confirmed twenty-three cluster SNe Ia, four of which were intracluster events. Using our deep Canada-France-Hawaii Telescope/MegaCam imaging, we measured total stellar luminosities in each of our galaxy clusters, and we performed detailed supernova (SN) detection efficiency simulations. Bringing these ingredients together, we measure an overall cluster SN Ia rate within R{sub 200} (1 Mpc) of 0.042{sup +0.012}{sub -0.010}{sup +0.010}{sub -0.008} SNuM (0.049{sup +0.016}{sub -0.014}{sup +0.005}{sub -0.004} SNuM) and an SN Ia rate within red-sequence galaxies of 0.041{sup +0.015}{sub -0.015}{sup +0.005}{sub -0.010} SNuM (0.041{sup +0.019}{sub -0.015}{sup +0.005}{sub -0.004} SNuM). The red-sequence SN Ia rate is consistent with published rates in early-type/elliptical galaxies in the 'field'. Using our red-sequence SN Ia rate, and other cluster SN measurements in early-type galaxies up to z {approx} 1, we derive the late-time (>2 Gyr) delay time distribution (DTD) of SN Ia assuming a cluster early-type galaxy star formation epoch of z{sub f} = 3. Assuming a power-law form for the DTD, {Psi}(t){proportional_to}t{sup s} , we find s = -1.62 {+-} 0.54. This result is consistent with predictions for the double degenerate SN Ia progenitor scenario (s {approx} -1) and is also in line with recent calculations for the double detonation explosion mechanism (s {approx} -2). The most recent calculations of the single degenerate scenario DTD predicts an order-of-magnitude drop-off in SN Ia rate {approx}6-7 Gyr after stellar formation, and the observed cluster rates cannot rule this out.

  4. Proof-of-principle test of coherent-state continuous variable quantum key distribution through turbulent atmosphere (Conference Presentation)

    Derkach, Ivan D.; Peuntinger, Christian; Ruppert, László; Heim, Bettina; Gunthner, Kevin; Usenko, Vladyslav C.; Elser, Dominique; Marquardt, Christoph; Filip, Radim; Leuchs, Gerd

    2016-10-01

    Continuous-variable quantum key distribution is a practical application of quantum information theory that is aimed at generation of secret cryptographic key between two remote trusted parties and that uses multi-photon quantum states as carriers of key bits. Remote parties share the secret key via a quantum channel, that presumably is under control of of an eavesdropper, and which properties must be taken into account in the security analysis. Well-studied fiber-optical quantum channels commonly possess stable transmittance and low noise levels, while free-space channels represent a simpler, less demanding and more flexible alternative, but suffer from atmospheric effects such as turbulence that in particular causes a non-uniform transmittance distribution referred to as fading. Nonetheless free-space channels, providing an unobstructed line-of-sight, are more apt for short, mid-range and potentially long-range (using satellites) communication and will play an important role in the future development and implementation of QKD networks. It was previously theoretically shown that coherent-state CV QKD should be in principle possible to implement over a free-space fading channel, but strong transmittance fluctuations result in the significant modulation-dependent channel excess noise. In this regime the post-selection of highly transmitting sub-channels may be needed, which can even restore the security of the protocol in the strongly turbulent channels. We now report the first proof-of-principle experimental test of coherent state CV QKD protocol using different levels Gaussian modulation over a mid-range (1.6-kilometer long) free-space atmospheric quantum channel. The transmittance of the link was characterized using intensity measurements for the reference but channel estimation using the modulated coherent states was also studied. We consider security against Gaussian collective attacks, that were shown to be optimal against CV QKD protocols . We assumed a

  5. Modeling delay in genetic networks: from delay birth-death processes to delay stochastic differential equations.

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Bennett, Matthew R; Josić, Krešimir; Ott, William

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  6. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Bennett, Matthew R. [Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77204, USA and Institute of Biosciences and Bioengineering, Rice University, Houston, Texas 77005 (United States); Josić, Krešimir [Department of Mathematics, University of Houston, Houston, Texas 77004 (United States); Department of Biology and Biochemistry, University of Houston, Houston, Texas 77204 (United States)

    2014-05-28

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay.

  7. Modeling delay in genetic networks: From delay birth-death processes to delay stochastic differential equations

    Gupta, Chinmaya; López, José Manuel; Azencott, Robert; Ott, William; Bennett, Matthew R.; Josić, Krešimir

    2014-01-01

    Delay is an important and ubiquitous aspect of many biochemical processes. For example, delay plays a central role in the dynamics of genetic regulatory networks as it stems from the sequential assembly of first mRNA and then protein. Genetic regulatory networks are therefore frequently modeled as stochastic birth-death processes with delay. Here, we examine the relationship between delay birth-death processes and their appropriate approximating delay chemical Langevin equations. We prove a quantitative bound on the error between the pathwise realizations of these two processes. Our results hold for both fixed delay and distributed delay. Simulations demonstrate that the delay chemical Langevin approximation is accurate even at moderate system sizes. It captures dynamical features such as the oscillatory behavior in negative feedback circuits, cross-correlations between nodes in a network, and spatial and temporal information in two commonly studied motifs of metastability in biochemical systems. Overall, these results provide a foundation for using delay stochastic differential equations to approximate the dynamics of birth-death processes with delay

  8. Global asymptotic stability of hybrid bidirectional associative memory neural networks with time delays

    Arik, Sabri

    2006-01-01

    This Letter presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. The results are also compared with the previous results derived in the literature

  9. Global asymptotic stability of hybrid bidirectional associative memory neural networks with time delays

    Arik, Sabri

    2006-02-01

    This Letter presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all bounded continuous non-monotonic neuron activation functions. The results are also compared with the previous results derived in the literature.

  10. Delayed Puberty

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    . The underlying reasons for the large variation in the age at pubertal onset are not fully established; however, nutritional status and socioeconomic and environmental factors are known to be influencing, and a significant amount of influencing genetic factors have also been identified. The challenges...... optimal in discriminating especially CDGP from HH. Management of the delayed puberty depends on the etiology. For boys with CDGP an observational period will often reveal imminent puberty. If puberty is not progressing spontaneously, sex steroid replacement is effective in stimulating the development...

  11. Network-scale spatial and temporal variation in Chinook salmon (Oncorhynchus tshawytscha) redd distributions: patterns inferred from spatially continuous replicate surveys

    Daniel J. Isaak; Russell F. Thurow

    2006-01-01

    Spatially continuous sampling designs, when temporally replicated, provide analytical flexibility and are unmatched in their ability to provide a dynamic system view. We have compiled such a data set by georeferencing the network-scale distribution of Chinook salmon (Oncorhynchus tshawytscha) redds across a large wilderness basin (7330 km2) in...

  12. Research on Soft Reduction Amount Distribution to Eliminate Typical Inter-dendritic Crack in Continuous Casting Slab of X70 Pipeline Steel by Numerical Model

    Liu, Ke; Wang, Chang; Liu, Guo-liang; Ding, Ning; Sun, Qi-song; Tian, Zhi-hong

    2017-04-01

    To investigate the formation of one kind of typical inter-dendritic crack around triple point region in continuous casting(CC) slab during the operation of soft reduction, fully coupled 3D thermo-mechanical finite element models was developed, also plant trials were carried out in a domestic continuous casting machine. Three possible types of soft reduction amount distribution (SRAD) in the soft reduction region were analyzed. The relationship between the typical inter-dendritic cracks and soft reduction conditions is presented and demonstrated in production practice. Considering the critical strain of internal crack formation, a critical tolerance for the soft reduction amount distribution and related casing parameters have been proposed for better contribution of soft reduction to the internal quality of slabs. The typical inter-dendritic crack around the triple point region had been eliminated effectively through the application of proposed suggestions for continuous casting of X70 pipeline steel in industrial practice.

  13. Time Delay of CGM Sensors

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  14. Continued Development of Environmentally COnscious "ECO" Transport Aircraft Concepts as Hybrid Electric Distributed Propulsion Research Platforms, Phase II

    National Aeronautics and Space Administration — ESAero's vast TeDP and HEDP-specific experience, Helden Aerospace's distributed propulsion airframe integration effects (2) Advance the TMS design with a new TMS...

  15. Synchronization in networks with heterogeneous coupling delays

    Otto, Andreas; Radons, Günter; Bachrathy, Dániel; Orosz, Gábor

    2018-01-01

    Synchronization in networks of identical oscillators with heterogeneous coupling delays is studied. A decomposition of the network dynamics is obtained by block diagonalizing a newly introduced adjacency lag operator which contains the topology of the network as well as the corresponding coupling delays. This generalizes the master stability function approach, which was developed for homogenous delays. As a result the network dynamics can be analyzed by delay differential equations with distributed delay, where different delay distributions emerge for different network modes. Frequency domain methods are used for the stability analysis of synchronized equilibria and synchronized periodic orbits. As an example, the synchronization behavior in a system of delay-coupled Hodgkin-Huxley neurons is investigated. It is shown that the parameter regions where synchronized periodic spiking is unstable expand when increasing the delay heterogeneity.

  16. Continuous soil maps - a fuzzy set approach to bridge the gap between aggregation levels of process and distribution models

    Gruijter, de J.J.; Walvoort, D.J.J.; Gaans, van P.F.M.

    1997-01-01

    Soil maps as multi-purpose models of spatial soil distribution have a much higher level of aggregation (map units) than the models of soil processes and land-use effects that need input from soil maps. This mismatch between aggregation levels is particularly detrimental in the context of precision

  17. Drop size distribution evolution after continuous or intermittent injection of butane or propane in a confined air flow

    Knubben, G.; Geld, van der C.W.M.

    1999-01-01

    Drop size distributions and velocities have been measured of n-butane and propane sprays, rapidly evaporating in air flowing at constant velocity, 15 m/s typically. The inlet air temperature has been found to be of main importance in the evaporation process. After a period of the order of the

  18. Prediction of δ-ferrite distribution in continuously cast type 304 stainless steel slabs by diffusion transformation analysis

    Kim, J. Joon; Kim, Sun K.; Kim, Jong W.

    1998-01-01

    Retained δ-ferrite in 304 stainless steel is known to prevent hot cracking during continuous casting. Excess content of retained δ-ferrite lowers the hot workability. So it is necessary to control the amount of retained δ-ferrite in stainless steel. A numerical model based on coupled analysis of macro heat transfer and micro diffusion transformation has been developed in order to predict retained δ-ferrite in continuously cast 304 stainless steel slab. The finite difference technique for moving boundary problem has been formulated utilizing 'murray-landis variable-grid method'. The reliability of numerical model is compared with the other results. The prediction of δ-ferrite content in CC type 304 stainless steel slabs shows good agreement between measured and predicted results. Effect of secondary cooling condition on the δ-ferrite has been also investigated

  19. Continuous passive motion and physical therapy (CPM) versus physical therapy (PT) versus delayed physical therapy (DPT) after surgical release for elbow contractures; a study protocol for a prospective randomized controlled trial.

    Viveen, Jetske; Doornberg, Job N; Kodde, Izaak F; Goossens, Pjotr; Koenraadt, Koen L M; The, Bertram; Eygendaal, Denise

    2017-11-22

    The elbow is prone to stiffness after trauma. To regain functional elbow motion several conservative- and surgical treatment options are available. Conservative treatment includes physical therapy, intra-articular injections with corticosteroids and a static progressive or dynamic splinting program. If conservative treatment fails, an operative release of the posttraumatic stiff elbow is often performed. The best Evidence-Based rehabilitation protocol for patients after an operative release is unknown to date and differs per surgeon, hospital and country. Options include early- or delayed motion supervised by a physical therapist, immediate continuous passive motion (CPM), (night) splinting and a static progressive or dynamic splinting program. The SET-Study (Stiff Elbow Trial) is a single-centre, prospective, randomized controlled trial. The primary objective of this study is to compare the active Range of Motion (ROM) (flexion arc and rotational arc) twelve months after surgery between three groups. The first group will receive in-hospital CPM in combination with early motion Physical Therapy (PT) supervised by a physical therapist, the second group will receive only in-hospital early motion PT supervised by a physical therapist and the third group will receive outpatient supervised PT from postoperative day seven till ten. Secondary outcome measures will be Patient Reported Outcome Measures (PROMs) including the Mayo Elbow Performance Score (MEPS), the Oxford Elbow Score (OES), the quick Disabilities of Arm, Shoulder and Hand (qDASH) score, Visual Analogue pain Scale in rest and activity (VAS), Pain Catastrophizing Scale (PCS), the Short Form (SF)-36, the Centre for Epidemiological Studies Depression Scale Revised (CESD-R) and the Work Rehabilitation Questionnaire (WORQ) for the upper limb. A successful completion of this trial will provide evidence on the best rehabilitation protocol in order to (re)gain optimal motion after surgical release of the stiff elbow

  20. CITRATE 1.0: Phytoplankton continuous trait-distribution model with one-dimensional physical transport applied to the North Pacific

    B. Chen

    2018-02-01

    Full Text Available Diversity plays critical roles in ecosystem functioning, but it remains challenging to model phytoplankton diversity in order to better understand those roles and reproduce consistently observed diversity patterns in the ocean. In contrast to the typical approach of resolving distinct species or functional groups, we present a ContInuous TRAiT-basEd phytoplankton model (CITRATE that focuses on macroscopic system properties such as total biomass, mean trait values, and trait variance. This phytoplankton component is embedded within a nitrogen–phytoplankton-zooplankton–detritus–iron model that itself is coupled with a simplified one-dimensional ocean model. Size is used as the master trait for phytoplankton. CITRATE also incorporates trait diffusion for sustaining diversity and simple representations of physiological acclimation, i.e., flexible chlorophyll-to-carbon and nitrogen-to-carbon ratios. We have implemented CITRATE at two contrasting stations in the North Pacific where several years of observational data are available. The model is driven by physical forcing including vertical eddy diffusivity imported from three-dimensional general ocean circulation models (GCMs. One common set of model parameters for the two stations is optimized using the Delayed-Rejection Adaptive Metropolis–Hasting Monte Carlo (DRAM algorithm. The model faithfully reproduces most of the observed patterns and gives robust predictions on phytoplankton mean size and size diversity. CITRATE is suitable for applications in GCMs and constitutes a prototype upon which more sophisticated continuous trait-based models can be developed.

  1. CITRATE 1.0: Phytoplankton continuous trait-distribution model with one-dimensional physical transport applied to the North Pacific

    Chen, Bingzhang; Smith, Sherwood Lan

    2018-02-01

    Diversity plays critical roles in ecosystem functioning, but it remains challenging to model phytoplankton diversity in order to better understand those roles and reproduce consistently observed diversity patterns in the ocean. In contrast to the typical approach of resolving distinct species or functional groups, we present a ContInuous TRAiT-basEd phytoplankton model (CITRATE) that focuses on macroscopic system properties such as total biomass, mean trait values, and trait variance. This phytoplankton component is embedded within a nitrogen-phytoplankton-zooplankton-detritus-iron model that itself is coupled with a simplified one-dimensional ocean model. Size is used as the master trait for phytoplankton. CITRATE also incorporates trait diffusion for sustaining diversity and simple representations of physiological acclimation, i.e., flexible chlorophyll-to-carbon and nitrogen-to-carbon ratios. We have implemented CITRATE at two contrasting stations in the North Pacific where several years of observational data are available. The model is driven by physical forcing including vertical eddy diffusivity imported from three-dimensional general ocean circulation models (GCMs). One common set of model parameters for the two stations is optimized using the Delayed-Rejection Adaptive Metropolis-Hasting Monte Carlo (DRAM) algorithm. The model faithfully reproduces most of the observed patterns and gives robust predictions on phytoplankton mean size and size diversity. CITRATE is suitable for applications in GCMs and constitutes a prototype upon which more sophisticated continuous trait-based models can be developed.

  2. Application of the single-channel continuous synthesis method to criticity and power distribution calculations in thermal reactors

    Medrano Asensio, Gregorio.

    1976-06-01

    A detailed power distribution calculation in a large power reactor requires the solution of the multigroup 3D diffusion equations. Using the finite difference method, this computation is too expensive to be performed for design purposes. This work is devoted to the single channel continous synthesis method: the choice of the trial functions and the determination of the mixing functions are discussed in details; 2D and 3D results are presented. The method is applied to the calculation of the IAEA ''Benchmark'' reactor and the results obtained are compared with a finite element resolution and with published results [fr

  3. The NOvA Data Acquistion System: A highly distributed, synchronized, continuous readout system for a long baseline neutrino experiment

    CERN. Geneva

    2012-01-01

    The NOvA experiment at Fermi National Accelerator Lab, has been designed and optimized to perform a suite of measurements critical to our understanding of the neutrino’s properties, their oscillations and their interactions. NOvA presents a unique set of data acquisition and computing challenges due to the immense size of the detectors, the data volumes that are generated through the continuous digitization of the frontend systems, and the need to buffer the full data stream to allow for highly asynchronous triggering and extraction of physics events. These challenges are compounded by the stringent timing and synchronization requirements that are placed on the acquisition systems by the need to precisely correlate information between the accelerator complex and the remote detector locations. The NOvA Data Acquisition system has been designed and built to meets these challenges. The system utilizes a highly modular, novel acquisition and event building scheme, which has been deployed on a large hierarch...

  4. Analytical applications for delayed neutrons

    Eccleston, G.W.

    1983-01-01

    Analytical formulations that describe the time dependence of neutron populations in nuclear materials contain delayed-neutron dependent terms. These terms are important because the delayed neutrons, even though their yields in fission are small, permit control of the fission chain reaction process. Analytical applications that use delayed neutrons range from simple problems that can be solved with the point reactor kinetics equations to complex problems that can only be solved with large codes that couple fluid calculations with the neutron dynamics. Reactor safety codes, such as SIMMER, model transients of the entire reactor core using coupled space-time neutronics and comprehensive thermal-fluid dynamics. Nondestructive delayed-neutron assay instruments are designed and modeled using a three-dimensional continuous-energy Monte Carlo code. Calculations on high-burnup spent fuels and other materials that contain a mix of uranium and plutonium isotopes require accurate and complete information on the delayed-neutron periods, yields, and energy spectra. A continuing need exists for delayed-neutron parameters for all the fissioning isotopes

  5. Delays and networked control systems

    Hetel, Laurentiu; Daafouz, Jamal; Johansson, Karl

    2016-01-01

    This edited monograph includes state-of-the-art contributions on continuous time dynamical networks with delays. The book is divided into four parts. The first part presents tools and methods for the analysis of time-delay systems with a particular attention on control problems of large scale or infinite-dimensional systems with delays. The second part of the book is dedicated to the use of time-delay models for the analysis and design of Networked Control Systems. The third part of the book focuses on the analysis and design of systems with asynchronous sampling intervals which occur in Networked Control Systems. The last part of the book exposes several contributions dealing with the design of cooperative control and observation laws for networked control systems. The target audience primarily comprises researchers and experts in the field of control theory, but the book may also be beneficial for graduate students. .

  6. Delayed Senescence

    2004-01-01

    Researcher Dr. Yi Li developed a technique to manipulate certain characteristics of plant growth such as anit-senescence. For example, the tobacco leaf was clipped from a transgenic plant (right), and a wildtype plant (left). During ground-based laboratory studies, both leaves were left in a darkened area for 4 months. When retrieved, the wildtype plant leaf was dried-out and the transgenic leaf remained fresh and green. A variation of this technology that involves manipulating plant hormones has been conducted in space-based studies on tomato plants through BioServe Space Technologies. The transport and distribution of auxin, an important plant hormone has shown to be influenced by microgravity, which could lead to improving the quality of fruits and vegetables grown on Earth.

  7. Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function.

    Qin, Qin; Huang, Alan J; Hua, Jun; Desmond, John E; Stevens, Robert D; van Zijl, Peter C M

    2014-02-01

    Measurement of the cerebral blood flow (CBF) with whole-brain coverage is challenging in terms of both acquisition and quantitative analysis. In order to fit arterial spin labeling-based perfusion kinetic curves, an empirical three-parameter model which characterizes the effective impulse response function (IRF) is introduced, which allows the determination of CBF, the arterial transit time (ATT) and T(1,eff). The accuracy and precision of the proposed model were compared with those of more complicated models with four or five parameters through Monte Carlo simulations. Pseudo-continuous arterial spin labeling images were acquired on a clinical 3-T scanner in 10 normal volunteers using a three-dimensional multi-shot gradient and spin echo scheme at multiple post-labeling delays to sample the kinetic curves. Voxel-wise fitting was performed using the three-parameter model and other models that contain two, four or five unknown parameters. For the two-parameter model, T(1,eff) values close to tissue and blood were assumed separately. Standard statistical analysis was conducted to compare these fitting models in various brain regions. The fitted results indicated that: (i) the estimated CBF values using the two-parameter model show appreciable dependence on the assumed T(1,eff) values; (ii) the proposed three-parameter model achieves the optimal balance between the goodness of fit and model complexity when compared among the models with explicit IRF fitting; (iii) both the two-parameter model using fixed blood T1 values for T(1,eff) and the three-parameter model provide reasonable fitting results. Using the proposed three-parameter model, the estimated CBF (46 ± 14 mL/100 g/min) and ATT (1.4 ± 0.3 s) values averaged from different brain regions are close to the literature reports; the estimated T(1,eff) values (1.9 ± 0.4 s) are higher than the tissue T1 values, possibly reflecting a contribution from the microvascular arterial blood compartment

  8. Continuous Steering Stability Control Based on an Energy-Saving Torque Distribution Algorithm for a Four in-Wheel-Motor Independent-Drive Electric Vehicle

    Li Zhai

    2018-02-01

    Full Text Available In this paper, a continuous steering stability controller based on an energy-saving torque distribution algorithm is proposed for a four in-wheel-motor independent-drive electric vehicle (4MIDEV to improve the energy consumption efficiency while maintaining the stability in steering maneuvers. The controller is designed as a hierarchical structure, including the reference model level, the upper-level controller, and the lower-level controller. The upper-level controller adopts the direct yaw moment control (DYC, which is designed to work continuously during the steering maneuver to better ensure steering stability in extreme situations, rather than working only after the vehicle is judged to be unstable. An adaptive two-hierarchy energy-saving torque distribution algorithm is developed in the lower-level controller with the friction ellipse constraint as a basis for judging whether the algorithm needs to be switched, so as to achieve a more stable and energy-efficient steering operation. The proposed stability controller was validated in a co-simulation of CarSim and Matlab/Simulink. The simulation results under different steering maneuvers indicate that the proposed controller, compared with the conventional servo controller and the ordinary continuous controller, can reduce energy consumption up to 23.68% and improve the vehicle steering stability.

  9. Mathematical modeling of methyl ester concentration distribution in a continuous membrane tubular reactor and comparison with conventional tubular reactor

    Talaghat, M. R.; Jokar, S. M.; Modarres, E.

    2017-10-01

    The reduction of fossil fuel resources and environmental issues made researchers find alternative fuels include biodiesels. One of the most widely used methods for production of biodiesel on a commercial scale is transesterification method. In this work, the biodiesel production by a transesterification method was modeled. Sodium hydroxide was considered as a catalyst to produce biodiesel from canola oil and methanol in a continuous tubular ceramic membranes reactor. As the Biodiesel production reaction from triglycerides is an equilibrium reaction, the reaction rate constants depend on temperature and related linearly to catalyst concentration. By using the mass balance for a membrane tubular reactor and considering the variation of raw materials and products concentration with time, the set of governing equations were solved by numerical methods. The results clearly show the superiority of membrane reactor than conventional tubular reactors. Afterward, the influences of molar ratio of alcohol to oil, weight percentage of the catalyst, and residence time on the performance of biodiesel production reactor were investigated.

  10. Distribution

    John R. Jones

    1985-01-01

    Quaking aspen is the most widely distributed native North American tree species (Little 1971, Sargent 1890). It grows in a great diversity of regions, environments, and communities (Harshberger 1911). Only one deciduous tree species in the world, the closely related Eurasian aspen (Populus tremula), has a wider range (Weigle and Frothingham 1911)....

  11. Using continuous sampling to examine the distribution of traffic related air pollution in proximity to a major road

    McAdam, Kim; Steer, Peter; Perrotta, Kim

    2011-04-01

    A study to characterize the distribution of vehicle related air pollution in proximity to a major arterial road was undertaken to inform local land use planning and policy regarding separation distances that could help reduce exposure for new sensitive land use development. Measurements of criteria air contaminants were made at ground level, 10 m, 30 m, and 60 m from curb side, and at 9 m height, 10 m from curb side along a traffic corridor carrying over 34,000 vehicles per day. Pollutant decay with distance or height was not statistically significant for O 3, CO, or SO 2. No clear distance decay pattern emerged for PM 2.5. Compared to concentrations at ground level 30 m from curb side, concentrations at 10 m, 60 m, and 10 m at 9 m height were 83%, 45% and 54% higher, respectively. For NO, NO 2, and NO x, however, there was a statistically significant decline in concentrations with distance with the decay most apparent from 30 m to 60 m from the road. Concentrations at 10 m from curb side at 9 m height were equivalent to (all wind conditions) or less than (downwind conditions) those at 30 m and ground level. These findings suggest that for protection of public health in the near road environment, vertical distance is an important determinant of exposure to pollutants that are key indicators of traffic related air pollution. This has implications for sensitive land use development in proximity to high volume traffic corridors.

  12. Delayed puberty in girls

    ... sexual development - girls; Pubertal delay - girls; Constitutional delayed puberty ... In most cases of delayed puberty, growth changes just begin later than usual, sometimes called a late bloomer. Once puberty begins, it progresses normally. This pattern runs ...

  13. Delayed Puberty (For Teens)

    ... Safe Videos for Educators Search English Español Delayed Puberty KidsHealth / For Teens / Delayed Puberty What's in this ... wonder if there's anything wrong. What Is Delayed Puberty? Puberty is the time when your body grows ...

  14. Highly efficient single-pass frequency doubling of a continuous-wave distributed feedback laser diode using a PPLN waveguide crystal at 488 nm.

    Jechow, Andreas; Schedel, Marco; Stry, Sandra; Sacher, Joachim; Menzel, Ralf

    2007-10-15

    A continuous-wave distributed feedback diode laser emitting at 976 nm was frequency doubled by the use of a periodically poled lithium niobate waveguide crystal with a channel size of 3 microm x 5 microm and an interaction length of 10 mm. A laser to waveguide coupling efficiency of 75% could be achieved resulting in 304 mW of incident infrared light inside the waveguide. Blue laser light emission of 159 mW at 488 nm has been generated, which equals to a conversion efficiency of 52%. The resulting wall plug efficiency was 7.4%.

  15. Low endemism, continued deep-shallow interchanges, and evidence for cosmopolitan distributions in free-living marine nematodes (order Enoplida

    Thomas W Kelley

    2010-12-01

    Full Text Available Abstract Background Nematodes represent the most abundant benthic metazoa in one of the largest habitats on earth, the deep sea. Characterizing major patterns of biodiversity within this dominant group is a critical step towards understanding evolutionary patterns across this vast ecosystem. The present study has aimed to place deep-sea nematode species into a phylogenetic framework, investigate relationships between shallow water and deep-sea taxa, and elucidate phylogeographic patterns amongst the deep-sea fauna. Results Molecular data (18 S and 28 S rRNA confirms a high diversity amongst deep-sea Enoplids. There is no evidence for endemic deep-sea lineages in Maximum Likelihood or Bayesian phylogenies, and Enoplids do not cluster according to depth or geographic location. Tree topologies suggest frequent interchanges between deep-sea and shallow water habitats, as well as a mixture of early radiations and more recently derived lineages amongst deep-sea taxa. This study also provides convincing evidence of cosmopolitan marine species, recovering a subset of Oncholaimid nematodes with identical gene sequences (18 S, 28 S and cox1 at trans-Atlantic sample sites. Conclusions The complex clade structures recovered within the Enoplida support a high global species richness for marine nematodes, with phylogeographic patterns suggesting the existence of closely related, globally distributed species complexes in the deep sea. True cosmopolitan species may additionally exist within this group, potentially driven by specific life history traits of Enoplids. Although this investigation aimed to intensively sample nematodes from the order Enoplida, specimens were only identified down to genus (at best and our sampling regime focused on an infinitesimal small fraction of the deep-sea floor. Future nematode studies should incorporate an extended sample set covering a wide depth range (shelf, bathyal, and abyssal sites, utilize additional genetic loci (e

  16. Precise delay measurement through combinatorial logic

    Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

    2010-01-01

    A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

  17. Modeling of gas condensates properties using continuous distribution functions for the characterization of the plus fraction; Modelisation des proprietes thermodynamiques des gaz a condensat par representation de la fraction lourde a l`aide de fonctions de distribution

    Sportisse, M.

    1996-12-20

    The modeling of thermodynamic behaviour for gas condensates is not yet satisfactory and it involves an adjustment of thermodynamic models. We propose here a fitting based on the characterization of the plus fraction using three continuous distribution functions associated to the following families: n-alkanes, n-alkylbenzenes and poly-aromatics. No continuous thermodynamic model is used and PVT calculations are made with the Peng-Robinson equation of state. For poly-aromatics, a simple correlation of {l_brace} T{sub c}, P{sub c}, {omega} {r_brace} is given. The parameters of the distributions are fitted in order to improve the accuracy of the liquid deposit curve calculation. A continuous minimization by simulated annealing has been used to avoid local minima. Good results on fitting PVT properties have been obtained with more than twenty gas condensates from different areas. Moreover, the prediction of tank liquid and heavy-plus fraction densities are given with an average deviation of 1.2 % and 3.6 %. Tests on temperature extrapolation show that our modeling yields a good representation of pressure and temperature influence on gas condensates behaviour. (author) 89 refs.

  18. A delay-dependent approach to robust control for neutral uncertain neural networks with mixed interval time-varying delays

    Lu, Chien-Yu

    2011-01-01

    This paper considers the problem of delay-dependent global robust stabilization for discrete, distributed and neutral interval time-varying delayed neural networks described by nonlinear delay differential equations of the neutral type. The parameter uncertainties are norm bounded. The activation functions are assumed to be bounded and globally Lipschitz continuous. Using a Lyapunov functional approach and linear matrix inequality (LMI) techniques, the stability criteria for the uncertain neutral neural networks with interval time-varying delays are established in the form of LMIs, which can be readily verified using the standard numerical software. An important feature of the result reported is that all the stability conditions are dependent on the upper and lower bounds of the delays. Another feature of the results lies in that it involves fewer free weighting matrix strategy, and upper bounds of the inner product between two vectors are not introduced to reduce the conservatism of the criteria. Two illustrative examples are provided to demonstrate the effectiveness and the reduced conservatism of the proposed method

  19. Speech and Language Delay

    ... OTC Relief for Diarrhea Home Diseases and Conditions Speech and Language Delay Condition Speech and Language Delay Share Print Table of Contents1. ... Treatment6. Everyday Life7. Questions8. Resources What is a speech and language delay? A speech and language delay ...

  20. Fuzzy extractors for continuous distributions

    Buhan, I.R.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.; Deng, R.; Samarati, P.

    We show that there is a direct relation between the maximum length of the keys extracted from biometric data and the error rates of the biometric system. The length of the bio-key depends on the amount of information that can be extracted from the source data. This information can be used a-priori

  1. Fuzzy extractors for continuous distributions

    Buhan, I.R.; Doumen, J.M.; Hartel, Pieter H.; Veldhuis, Raymond N.J.

    2006-01-01

    We show that there is a direct relation between the maximum length of the keys extracted from biometric data and the error rates of the biometric system. The length of the bio-key depends on the amount of distinguishing information that can be extracted from the source data. This information can be

  2. On the problem of non-zero word error rates for fixed-rate error correction codes in continuous variable quantum key distribution

    Johnson, Sarah J; Ong, Lawrence; Shirvanimoghaddam, Mahyar; Lance, Andrew M; Symul, Thomas; Ralph, T C

    2017-01-01

    The maximum operational range of continuous variable quantum key distribution protocols has shown to be improved by employing high-efficiency forward error correction codes. Typically, the secret key rate model for such protocols is modified to account for the non-zero word error rate of such codes. In this paper, we demonstrate that this model is incorrect: firstly, we show by example that fixed-rate error correction codes, as currently defined, can exhibit efficiencies greater than unity. Secondly, we show that using this secret key model combined with greater than unity efficiency codes, implies that it is possible to achieve a positive secret key over an entanglement breaking channel—an impossible scenario. We then consider the secret key model from a post-selection perspective, and examine the implications for key rate if we constrain the forward error correction codes to operate at low word error rates. (paper)

  3. A Path-Based Gradient Projection Algorithm for the Cost-Based System Optimum Problem in Networks with Continuously Distributed Value of Time

    Wen-Xiang Wu

    2014-01-01

    Full Text Available The cost-based system optimum problem in networks with continuously distributed value of time is formulated as a path-based form, which cannot be solved by the Frank-Wolfe algorithm. In light of magnitude improvement in the availability of computer memory in recent years, path-based algorithms have been regarded as a viable approach for traffic assignment problems with reasonably large network sizes. We develop a path-based gradient projection algorithm for solving the cost-based system optimum model, based on Goldstein-Levitin-Polyak method which has been successfully applied to solve standard user equilibrium and system optimum problems. The Sioux Falls network tested is used to verify the effectiveness of the algorithm.

  4. Continuous scanning of the mobility and size distribution of charged clusters and nanometer particles in atmospheric air and the Balanced Scanning Mobility Analyzer BSMA

    Tammet, H.

    2006-12-01

    Measuring of charged nanometer particles in atmospheric air is a routine task in research on atmospheric electricity, where these particles are called the atmospheric ions. An aspiration condenser is the most popular instrument for measuring atmospheric ions. Continuous scanning of a mobility distribution is possible when the aspiration condenser is connected as an arm of a balanced bridge. Transfer function of an aspiration condenser is calculated according to the measurements of geometric dimensions, air flow rate, driving voltage, and electric current. The most complicated phase of the calibration is the estimation of the inlet loss of ions due to the Brownian deposition. The available models of ion deposition on the protective inlet screen and the inlet control electrofilter have the uncertainty of about 20%. To keep the uncertainty of measurements low the adsorption should not exceed a few tens of percent. The online conversion of the mobility distribution to the size distribution and a correct reduction of inlet losses are possible when air temperature and pressure are measured simultaneously with the mobility distribution. Two instruments called the Balanced Scanning Mobility Analyzers (BSMA) were manufactured and tested in routine atmospheric measurements. The concentration of atmospheric ions of the size of about a few nanometers is very low and a high air flow rate is required to collect enough of ion current. The air flow of 52 l/s exceeds the air flow in usual aerosol instruments by 2-3 orders of magnitude. The high flow rate reduces the time of ion passage to 60 ms and the heating of air in an analyzer to 0.2 K, which suppresses a possible transformation of ions inside the instrument. The mobility range of the BSMA of 0.032-3.2 cm 2 V - 1 s - 1 is logarithmically uniformly divided into 16 fractions. The size distribution is presented by 12 fractions in the diameter range of 0.4-7.5 nm. The measurement noise of a fraction concentration is typically

  5. UAVs and Control Delays

    de Vries, S. C

    2005-01-01

    .... Delays of about 250-300 ms often lead to unacceptable airplane handling qualities. Techniques such as filtering and predictive displays may extend the range of acceptable delays up to about 400 ms...

  6. Delayed puberty in boys

    ... page: //medlineplus.gov/ency/article/007695.htm Delayed puberty in boys To use the sharing features on this page, please enable JavaScript. Delayed puberty in boys is when puberty does not begin ...

  7. Chemical Continuous Time Random Walks

    Aquino, T.; Dentz, M.

    2017-12-01

    Traditional methods for modeling solute transport through heterogeneous media employ Eulerian schemes to solve for solute concentration. More recently, Lagrangian methods have removed the need for spatial discretization through the use of Monte Carlo implementations of Langevin equations for solute particle motions. While there have been recent advances in modeling chemically reactive transport with recourse to Lagrangian methods, these remain less developed than their Eulerian counterparts, and many open problems such as efficient convergence and reconstruction of the concentration field remain. We explore a different avenue and consider the question: In heterogeneous chemically reactive systems, is it possible to describe the evolution of macroscopic reactant concentrations without explicitly resolving the spatial transport? Traditional Kinetic Monte Carlo methods, such as the Gillespie algorithm, model chemical reactions as random walks in particle number space, without the introduction of spatial coordinates. The inter-reaction times are exponentially distributed under the assumption that the system is well mixed. In real systems, transport limitations lead to incomplete mixing and decreased reaction efficiency. We introduce an arbitrary inter-reaction time distribution, which may account for the impact of incomplete mixing. This process defines an inhomogeneous continuous time random walk in particle number space, from which we derive a generalized chemical Master equation and formulate a generalized Gillespie algorithm. We then determine the modified chemical rate laws for different inter-reaction time distributions. We trace Michaelis-Menten-type kinetics back to finite-mean delay times, and predict time-nonlocal macroscopic reaction kinetics as a consequence of broadly distributed delays. Non-Markovian kinetics exhibit weak ergodicity breaking and show key features of reactions under local non-equilibrium.

  8. Optimal control for parabolic-hyperbolic system with time delay

    Kowalewski, A.

    1985-07-01

    In this paper we consider an optimal control problem for a system described by a linear partial differential equation of the parabolic-hyperbolic type with time delay in the state. The right-hand side of this equation and the initial conditions are not continuous functions usually, but they are measurable functions belonging to L 2 or Lsup(infinity) spaces. Therefore, the solution of this equation is given by a certain Sobolev space. The time delay in the state is constant, but it can be also a function of time. The control time T is fixed in our problem. Making use of the Milutin-Dubovicki theorem, necessary and sufficient conditions of optimality with the quadratic performance functional and constrained control are derived for the Dirichlet problem. The flow chart of the algorithm which can be used in the numerical solving of certain optimization problems for distributed systems is also presented. (author)

  9. Delayed Orgasm and Anorgasmia

    Jenkins, Lawrence C.; Mulhall, John P.

    2015-01-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies; which include: medications, penile sensation loss, endocrinopathies, penile hyperstimulation and psychological etiologies, amongst others. Unfortunately, ...

  10. Global asymptotic stability analysis of bidirectional associative memory neural networks with time delays.

    Arik, Sabri

    2005-05-01

    This paper presents a sufficient condition for the existence, uniqueness and global asymptotic stability of the equilibrium point for bidirectional associative memory (BAM) neural networks with distributed time delays. The results impose constraint conditions on the network parameters of neural system independently of the delay parameter, and they are applicable to all continuous nonmonotonic neuron activation functions. It is shown that in some special cases of the results, the stability criteria can be easily checked. Some examples are also given to compare the results with the previous results derived in the literature.

  11. Continuous multivariate exponential extension

    Block, H.W.

    1975-01-01

    The Freund-Weinman multivariate exponential extension is generalized to the case of nonidentically distributed marginal distributions. A fatal shock model is given for the resulting distribution. Results in the bivariate case and the concept of constant multivariate hazard rate lead to a continuous distribution related to the multivariate exponential distribution (MVE) of Marshall and Olkin. This distribution is shown to be a special case of the extended Freund-Weinman distribution. A generalization of the bivariate model of Proschan and Sullo leads to a distribution which contains both the extended Freund-Weinman distribution and the MVE

  12. Nonlinear delay monopoly with bounded rationality

    Matsumoto, Akio; Szidarovszky, Ferenc

    2012-01-01

    The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

  13. Communication key using delay times in time-delayed chaos synchronization

    Kim, Chil-Min; Kye, Won-Ho; Rim, Sunghwan; Lee, Soo-Young

    2004-01-01

    We propose an efficient key scheme, which can generate a great number of communication keys, for communication using chaos synchronization. We have attained the keys from delay times of time-delay coupled chaotic systems. We explain the scheme and the efficiency by coupling Henon and logistic maps and illustrate them by coupling Navier-Stokes and Lorenz equations as a continuous system

  14. Hedgehog signaling pathway is active in GBM with GLI1 mRNA expression showing a single continuous distribution rather than discrete high/low clusters.

    Chandra, Vikas; Das, Tapojyoti; Gulati, Puneet; Biswas, Nidhan K; Rote, Sarang; Chatterjee, Uttara; Ghosh, Samarendra N; Deb, Sumit; Saha, Suniti K; Chowdhury, Anup K; Ghosh, Subhashish; Rudin, Charles M; Mukherjee, Ankur; Basu, Analabha; Dhara, Surajit

    2015-01-01

    Hedgehog (Hh) signaling pathway is a valid therapeutic target in a wide range of malignancies. We focus here on glioblastoma multiforme (GBM), a lethal malignancy of the central nervous system (CNS). By analyzing RNA-sequencing based transcriptomics data on 149 clinical cases of TCGA-GBM database we show here a strong correlation (r = 0.7) between GLI1 and PTCH1 mRNA expression--as a hallmark of the canonical Hh-pathway activity in this malignancy. GLI1 mRNA expression varied in 3 orders of magnitude among the GBM patients of the same cohort showing a single continuous distribution-unlike the discrete high/low-GLI1 mRNA expressing clusters of medulloblastoma (MB). When compared with MB as a reference, the median GLI1 mRNA expression in GBM appeared 14.8 fold lower than that of the "high-Hh" cluster of MB but 5.6 fold higher than that of the "low-Hh" cluster of MB. Next, we demonstrated statistically significant up- and down-regulation of GLI1 mRNA expressions in GBM patient-derived low-passage neurospheres in vitro by sonic hedgehog ligand-enriched conditioned media (shh-CM) and by Hh-inhibitor drug vismodegib respectively. We also showed clinically achievable dose (50 μM) of vismodegib alone to be sufficient to induce apoptosis and cell cycle arrest in these low-passage GBM neurospheres in vitro. Vismodegib showed an effect on the neurospheres, both by down-regulating GLI1 mRNA expression and by inducing apoptosis/cell cycle arrest, irrespective of their relative endogenous levels of GLI1 mRNA expression. We conclude from our study that this single continuous distribution pattern of GLI1 mRNA expression technically puts almost all GBM patients in a single group rather than discrete high- or low-clusters in terms of Hh-pathway activity. That is suggestive of therapies with Hh-pathway inhibitor drugs in this malignancy without a need for further stratification of patients on the basis of relative levels of Hh-pathway activity among them.

  15. Evaluation of biomolecular distributions in rat brain tissues by means of ToF-SIMS using a continuous beam of Ar clusters.

    Nakano, Shusuke; Yokoyama, Yuta; Aoyagi, Satoka; Himi, Naoyuki; Fletcher, John S; Lockyer, Nicholas P; Henderson, Alex; Vickerman, John C

    2016-06-08

    Time-of-flight secondary ion mass spectrometry (ToF-SIMS) provides detailed chemical structure information and high spatial resolution images. Therefore, ToF-SIMS is useful for studying biological phenomena such as ischemia. In this study, in order to evaluate cerebral microinfarction, the distribution of biomolecules generated by ischemia was measured with ToF-SIMS. ToF-SIMS data sets were analyzed by means of multivariate analysis for interpreting complex samples containing unknown information and to obtain biomolecular mapping indicated by fragment ions from the target biomolecules. Using conventional ToF-SIMS (primary ion source: Bi cluster ion), it is difficult to detect secondary ions beyond approximately 1000 u. Moreover, the intensity of secondary ions related to biomolecules is not always high enough for imaging because of low concentration even if the masses are lower than 1000 u. However, for the observation of biomolecular distributions in tissues, it is important to detect low amounts of biological molecules from a particular area of tissue. Rat brain tissue samples were measured with ToF-SIMS (J105, Ionoptika, Ltd., Chandlers Ford, UK), using a continuous beam of Ar clusters as a primary ion source. ToF-SIMS with Ar clusters efficiently detects secondary ions related to biomolecules and larger molecules. Molecules detected by ToF-SIMS were examined by analyzing ToF-SIMS data using multivariate analysis. Microspheres (45 μm diameter) were injected into the rat unilateral internal carotid artery (MS rat) to cause cerebral microinfarction. The rat brain was sliced and then measured with ToF-SIMS. The brain samples of a normal rat and the MS rat were examined to find specific secondary ions related to important biomolecules, and then the difference between them was investigated. Finally, specific secondary ions were found around vessels incorporating microspheres in the MS rat. The results suggest that important biomolecules related to cerebral

  16. [The Continuity Between World War II and the Postwar Period: Grant Distribution by the Japan Society for the Promotion of Science and the Subsidiary Fund for Scientific Research].

    Mizusawa, Hikari

    2015-01-01

    This paper analyzes the distribution of the Subsidiary Fund for Scientific Research, a predecessor to the Grant-in-Aid for Scientific Research (KAKENHI), which operated in Japan from the 1930s to 1950s. It reveals that the Japanese government maintained this wide-ranging promotion system since its establishment during the war until well into the postwar period. Previous studies insist that, at the end of the war, the Japanese government generally only funded the research that it considered immediately and practically useful. In contrast to this general perception, my analysis illustrates that both before and after the war, funding was allotted to four research areas: natural science, engineering, agriculture, and medicine. In order to illuminate this continuity, I compare the Subsidiary Fund with another research fund existing from 1933 to 1947: the Grant of the Japan Society for the Promotion of Science (JSPS). The comparison demonstrates that the JSPS received externally raised capital from the military and munitions companies. However, while this group focused upon engineering and military-related research as the war dragged on, the Subsidiary Fund has consistently entrusted scientists with the authority to decide the allocation of financial support.

  17. Predicting criteria continuous concentrations of 34 metals or metalloids by use of quantitative ion character-activity relationships–species sensitivity distributions (QICAR–SSD) model

    Mu, Yunsong; Wu, Fengchang; Chen, Cheng; Liu, Yuedan; Zhao, Xiaoli; Haiqing Liao; Giesy, John P.

    2014-01-01

    Criteria continuous concentrations (CCCs) are useful for describing chronic exposure to pollutants and setting water quality standards to protect aquatic life. However, because of financial, practical, or ethical restrictions on toxicity testing, few data are available to derive CCCs. In this study, CCCs for 34 metals or metalloids were derived using quantitative ion character-activity relationships–species sensitivity distributions (QICAR–SSD) and the final acute-chronic ratio (FACR) method. The results showed that chronic toxic potencies were correlated with several physico-chemical properties among eight species chosen, where the softness index was the most predictive characteristic. Predicted CCCs for most of the metals, except for Lead and Iron, were within a range of 10-fold of values recommended by the U.S. EPA. The QICAR–SSD model was superior to the FACR method for prediction of data-poor metals. This would have significance for predicting toxic potencies and criteria thresholds of more metals or metalloids. - Highlights: • We investigate relationships between σp and log-NOEC in eight species. • The QICAR–SSD model, FACR, and CMC/CCC were used to predict CCCs. • They are as a supplement to screening for toxicities, criteria and standards. - CCCs for 34 metals/metalloids were predicted by use of QICAR–SSD model and FACR method

  18. Predicting criteria continuous concentrations of 34 metals or metalloids by use of quantitative ion character-activity relationships-species sensitivity distributions (QICAR-SSD) model.

    Mu, Yunsong; Wu, Fengchang; Chen, Cheng; Liu, Yuedan; Zhao, Xiaoli; Haiqing Liao; Giesy, John P

    2014-05-01

    Criteria continuous concentrations (CCCs) are useful for describing chronic exposure to pollutants and setting water quality standards to protect aquatic life. However, because of financial, practical, or ethical restrictions on toxicity testing, few data are available to derive CCCs. In this study, CCCs for 34 metals or metalloids were derived using quantitative ion character-activity relationships-species sensitivity distributions (QICAR-SSD) and the final acute-chronic ratio (FACR) method. The results showed that chronic toxic potencies were correlated with several physico-chemical properties among eight species chosen, where the softness index was the most predictive characteristic. Predicted CCCs for most of the metals, except for Lead and Iron, were within a range of 10-fold of values recommended by the U.S. EPA. The QICAR-SSD model was superior to the FACR method for prediction of data-poor metals. This would have significance for predicting toxic potencies and criteria thresholds of more metals or metalloids. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Delayed orgasm and anorgasmia.

    Jenkins, Lawrence C; Mulhall, John P

    2015-11-01

    Delayed orgasm/anorgasmia defined as the persistent or recurrent difficulty, delay in, or absence of attaining orgasm after sufficient sexual stimulation, which causes personal distress. Delayed orgasm and anorgasmia are associated with significant sexual dissatisfaction. A focused medical history can shed light on the potential etiologies, which include medications, penile sensation loss, endocrinopathies, penile hyperstimulation, and psychological etiologies. Unfortunately, there are no excellent pharmacotherapies for delayed orgasm/anorgasmia, and treatment revolves largely around addressing potential causative factors and psychotherapy. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

  20. Delay in polling systems in heavy traffic

    van der Mei, Robert D.

    1998-10-01

    We study the delay in asymmetric cyclic polling systems with general mixtures of gated and exhaustive service, with generally distributed service times and switch-over times, in heavy traffic. We obtain closed-form expressions for all moments of the delay incurred at each of the queues. The expressions are strikingly simple and can even be expressed as finite products of known factors. The results provide new insights into the heavy-traffic behavior of polling systems.

  1. Analyzing delay causes in Egyptian construction projects

    Mohamed M. Marzouk

    2014-01-01

    Full Text Available Construction delays are common problems in civil engineering projects in Egypt. These problems occur frequently during project life-time leading to disputes and litigation. Therefore, it is essential to study and analyze causes of construction delays. This research presents a list of construction delay causes retrieved from literature. The feedback of construction experts was obtained through interviews. Subsequently, a questionnaire survey was prepared. The questionnaire survey was distributed to thirty-three construction experts who represent owners, consultants, and contractor’s organizations. Frequency Index, Severity Index, and Importance Index are calculated and according to the highest values of them the top ten delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the research. Statistical analysis is carried out using analysis of variance ANOVA method to test delay causes, obtained from the survey. The test results reveal good correlation between groups while there is significant difference between them for some delay causes and finally roadmap for prioritizing delay causes groups is presented.

  2. American Dream Delayed

    Khorunzhina, Natalia; Miller, Robert A.

    This paper investigates the delay in homeownership and a subsequent reduction in homeownership rate observed over the past decades. We focus on the delay in giving birth to children and increased labor market participation as contributing factors to homeownership dynamics for prime-age female hou...

  3. Delayed power analysis

    Adamovich, L.A.; Azarov, V.V.

    1999-01-01

    Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

  4. A novel perspective to calibrate temporal delays in cerebrovascular reactivity using hypercapnic and hyperoxic respiratory challenges.

    Champagne, Allen A; Bhogal, Alex A; Coverdale, Nicole S; Mark, Clarisse I; Cook, Douglas J

    2017-12-05

    Redistribution of blood flow across different brain regions, arising from the vasoactive nature of hypercapnia, can introduce errors when examining cerebrovascular reactivity (CVR) response delays. In this study, we propose a novel analysis method to characterize hemodynamic delays in the blood oxygen level dependent (BOLD) response to hypercapnia, and hyperoxia, as a way to provide insight into transient differences in vascular reactivity between cortical regions, and across tissue depths. A pseudo-continuous arterial spin labeling sequence was used to acquire BOLD and cerebral blood flow simultaneously in 19 healthy adults (12 F; 20 ± 2 years) during boxcar CO 2 and O 2 gas inhalation paradigms. Despite showing distinct differences in hypercapnia-induced response delay times (P  0.05) once calibrated for bolus arrival time derived using non-vasoactive hyperoxic gas challenges. Longer hypercapnic temporal delays were observed as the depth of the white matter tissue increased, although no significant differences in response lag were found during hyperoxia across tissue depth, or between grey and white matter. Furthermore, calibration of hypercapnic delays using hyperoxia revealed that deeper white matter layers may be more prone to dynamic redistribution of blood flow, which introduces response lag times ranging between 1 and 3 s in healthy subjects. These findings suggest that the combination of hypercapnic and hyperoxic gas-inhalation MRI can be used to distinguish between differences in CVR that arise as a result of delayed stimulus arrival time (due to the local architecture of the cerebrovasculature), or preferential blood flow distribution. Calibrated response delays to hypercapnia provide important insights into cerebrovascular physiology, and may be used to correct response delays associated with vascular impairment. Copyright © 2017. Published by Elsevier Inc.

  5. Continuous auditing & continuous monitoring : Continuous value?

    van Hillo, Rutger; Weigand, Hans; Espana, S; Ralyte, J; Souveyet, C

    2016-01-01

    Advancements in information technology, new laws and regulations and rapidly changing business conditions have led to a need for more timely and ongoing assurance with effectively working controls. Continuous Auditing (CA) and Continuous Monitoring (CM) technologies have made this possible by

  6. Neutron delayed choice experiments

    Bernstein, H.J.

    1986-01-01

    Delayed choice experiments for neutrons can help extend the interpretation of quantum mechanical phenomena. They may also rule out alternative explanations which static interference experiments allow. A simple example of a feasible neutron test is presented and discussed. (orig.)

  7. Quad nanosecond delay module

    McDonald, R.J.; Hunter, J.B.; Wozniak, G.J.

    1986-04-01

    Four nanosecond (ns) delay units have been designed to fit in a single-width NIM module. This module is particularly suited for use in conjunction with quad constant fraction timing discriminators (CFTDs) since it has four delay units that can be placed adjacent to the four units of the CFTD. A series of different length cables connected via DIP toggle switches provide delays of 0.60 ns in 4 ns increments. Thus, the CFTD delay can be optimized for pulses of different rise times from approx.10-100 ns. Design work for the PC board and silkscreening of the front panel were done with the MacDraw program on the Apple Mackintosh computer and printed with the Lasewriter printer. 6 refs

  8. Compensating for telecommunication delays during robotic telerehabilitation.

    Consoni, Leonardo J; Siqueira, Adriano A G; Krebs, Hermano I

    2017-07-01

    Rehabilitation robotic systems may afford better care and telerehabilitation may extend the use and benefits of robotic therapy to the home. Data transmissions over distance are bound by intrinsic communication delays which can be significant enough to deem the activity unfeasible. Here we describe an approach that combines unilateral robotic telerehabilitation and serious games. This approach has a modular and distributed design that permits different types of robots to interact without substantial code changes. We demonstrate the approach through an online multiplayer game. Two users can remotely interact with each other with no force exchanges, while a smoothing and prediction algorithm compensates motions for the delay in the Internet connection. We demonstrate that this approach can successfully compensate for data transmission delays, even when testing between the United States and Brazil. This paper presents the initial experimental results, which highlight the performance degradation with increasing delays as well as improvements provided by the proposed algorithm, and discusses planned future developments.

  9. Delayed rule following

    Schmitt, David R.

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [SD], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the SD. The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative even...

  10. Vernier Delay Unit

    Pierce, W.B.

    1984-10-01

    This module will accept differential ECL pulses from the auxiliary rear panel or NIM level pulses from the front panel. The pulses are produced at the output with a fixed delay that is software programmable in steps of 0.1 ns over the range of 0.1 to 10.5 ns. Multiple outputs are available at the front panel. Minimum delay through the module is 9 ns

  11. Quad precision delay generator

    Krishnan, Shanti; Gopalakrishnan, K.R.; Marballi, K.R.

    1997-01-01

    A Quad Precision Delay Generator delays a digital edge by a programmed amount of time, varying from nanoseconds to microseconds. The output of this generator has an amplitude of the order of tens of volts and rise time of the order of nanoseconds. This was specifically designed and developed to meet the stringent requirements of the plasma focus experiments. Plasma focus is a laboratory device for producing and studying nuclear fusion reactions in hot deuterium plasma. 3 figs

  12. Modelling delays in pharmacokinetics

    Farooqi, Z.H.; Lambrecht, R.M.

    1990-01-01

    Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

  13. On stochastic differential equations with random delay

    Krapivsky, P L; Luck, J M; Mallick, K

    2011-01-01

    We consider stochastic dynamical systems defined by differential equations with a uniform random time delay. The latter equations are shown to be equivalent to deterministic higher-order differential equations: for an nth-order equation with random delay, the corresponding deterministic equation has order n + 1. We analyze various examples of dynamical systems of this kind, and find a number of unusual behaviors. For instance, for the harmonic oscillator with random delay, the energy grows as exp((3/2) t 2/3 ) in reduced units. We then investigate the effect of introducing a discrete time step ε. At variance with the continuous situation, the discrete random recursion relations thus obtained have intrinsic fluctuations. The crossover between the fluctuating discrete problem and the deterministic continuous one as ε goes to zero is studied in detail on the example of a first-order linear differential equation

  14. Analytical solution of transient temperature in continuous wave end-pumped laser slab: Reduction of temperature distribution and time of thermal response

    Shibib Khalid S.

    2017-01-01

    Full Text Available An analytical solution of transient 3-D heat equation based on integral transform method is derived. The result are compared with numerical solution, and good agreements are obtained. Minimization of response time and temperature distribution through a laser slab are tested. It is found that the increasing in the lateral convection heat transfer coefficient can significantly reduce the response time and the temperature distribution while no effect on response time is observed when changing pumping profile from Gaussian to top hat beam in spite of the latter reduce the temperature distribution, also it is found that dividing the pumping power between two slab ends might reduce the temperature distribution and it has no effect on thermal response time.

  15. Synchronization of nonidentical chaotic neural networks with leakage delay and mixed time-varying delays

    Cao Jinde

    2011-01-01

    Full Text Available Abstract In this paper, an integral sliding mode control approach is presented to investigate synchronization of nonidentical chaotic neural networks with discrete and distributed time-varying delays as well as leakage delay. By considering a proper sliding surface and constructing Lyapunov-Krasovskii functional, as well as employing a combination of the free-weighting matrix method, Newton-Leibniz formulation and inequality technique, a sliding mode controller is designed to achieve the asymptotical synchronization of the addressed nonidentical neural networks. Moreover, a sliding mode control law is also synthesized to guarantee the reachability of the specified sliding surface. The provided conditions are expressed in terms of linear matrix inequalities, and are dependent on the discrete and distributed time delays as well as leakage delay. A simulation example is given to verify the theoretical results.

  16. The effects of the framing of time on delay discounting.

    DeHart, William Brady; Odum, Amy L

    2015-01-01

    We examined the effects of the framing of time on delay discounting. Delay discounting is the process by which delayed outcomes are devalued as a function of time. Time in a titrating delay discounting task is often framed in calendar units (e.g., as 1 week, 1 month, etc.). When time is framed as a specific date, delayed outcomes are discounted less compared to the calendar format. Other forms of framing time; however, have not been explored. All participants completed a titrating calendar unit delay-discounting task for money. Participants were also assigned to one of two delay discounting tasks: time as dates (e.g., June 1st, 2015) or time in units of days (e.g., 5000 days), using the same delay distribution as the calendar delay-discounting task. Time framed as dates resulted in less discounting compared to the calendar method, whereas time framed as days resulted in greater discounting compared to the calendar method. The hyperboloid model fit best compared to the hyperbola and exponential models. How time is framed may alter how participants attend to the delays as well as how the delayed outcome is valued. Altering how time is framed may serve to improve adherence to goals with delayed outcomes. © Society for the Experimental Analysis of Behavior.

  17. Concordance between monetary and sexual delay discounting in men who have sex with men.

    Jones, Jeb; Guest, Jodie L; Sullivan, Patrick S; Kramer, Michael R; Jenness, Samuel M; Sales, Jessica M

    2017-12-07

    Background: Delay discounting has been found to be associated with numerous health-related outcomes, including risky sexual behaviour. To date, it is unclear whether delay discounting measured in different domains is associated within individuals. The goal of this study was to assess the concordance of monetary and sexual delay discounting in men who have sex with men. Methods: Participants completed an online survey, including the Monetary Choice Questionnaire and the Sexual Discounting Task. Linear regression models were used to assess the association between monetary and sexual discount rates. Results: Sexual discount rates did not predict monetary discount rates. There was a substantial amount of clustering of sexual discount rates, requiring sexual discounting data to be categorised. Conclusions: Monetary and sexual delay discounting are distinct processes that are not necessarily associated within individuals, and monetary delay discounting is not an appropriate proxy measure for sexual impulsivity. Data from the Sexual Discounting Task are typically rank-transformed for analysis. These data suggest that this might be an invalid method of analysis. Future studies should investigate the distribution of their data to determine if it is appropriate to analyse sexual discounting data as a continuous measure.

  18. Time-Delay Effects on Constitutive Gene Expression*

    Feng Yan-Ling; Wang Dan; Tang Xu-Lei; Dong Jian-Min

    2017-01-01

    The dynamics of constitutive gene expression with delayed mRNA degradation is investigated, where the intrinsic noise caused by the small number of reactant molecules is introduced. It is found that the oscillatory behavior claimed in previous investigations does not appear in the approximation of small time delay, and the steady state distribution still follows the Poisson law. Furthermore, we introduce the extrinsic noise induced by surrounding environment to explore the effects of this noise and time delay on the Fano factor. Based on a delay Langevin equation and the corresponding Fokker–Planck equation, the distribution of mRNA copy-number is achieved analytically. The time delay and extrinsic noise play similar roles in the gene expression system, that is, they are able to result in the deviation of the Fano factor from 1 evidently. The measured Fano factor for constitutive gene expression is slightly larger than 1, which is perhaps attributed to the time-delay effect. (paper)

  19. The reasons for delay lumbar puncture

    MH. Lotfi

    2017-04-01

    Full Text Available Early diagnosis of meningitis and encephalitis and prompt initiation of appropriate therapy is vital and any delay will lead to high mortality and serious and permanent morbidity. The main purpose of this study was to evaluate the management of 220 patients with suspected central nervous system (CNS infections (meningitis and encephalitis to determine the percentage of patients’ suspected CNS infection undergo lumbar puncture in acceptable time (in accordance with conventional algorithms. In this descriptive study, patients with suspected CNS infections admitted to Bu-Ali and Qods hospitals, in the period July 2013 to December 2015 were studied. Information of 220 patients was collected. Continuous variables were summarized as means ± standard deviation and categorical variables as frequencies and percentages. Lumbar puncture (LP in patients was delayed in 200 cases (91%. Most common causes of delay in performing LP were prolongation of the process of determining patient needs to puncture, satisfying patients, CT scan delay and the delay in allowing LP by neurologist. In this study, delaying LP rate was higher than other studies. It seems certain pattern in assistants’ visits for counseling. CT requests and neurologic consultation before LP performed for all adult patients.

  20. Optimal Joint Expected Delay Forwarding in Delay Tolerant Networks

    Jia Xu; Xin Feng; Wen Jun Yang; Ru Chuan Wang; Bing Qing Han

    2013-01-01

    Multicopy forwarding schemes have been employed in delay tolerant network (DTN) to improve the delivery delay and delivery rate. Much effort has been focused on reducing the routing cost while retaining high performance. This paper aims to provide an optimal joint expected delay forwarding (OJEDF) protocol which minimizes the expected delay while satisfying a certain constant on the number of forwardings per message. We propose a comprehensive forwarding metric called joint expected delay (JE...

  1. RATES AND DELAY TIMES OF TYPE Ia SUPERNOVAE

    Ruiter, Ashley J.; Belczynski, Krzysztof; Fryer, Chris

    2009-01-01

    We analyze the evolution of binary stars to calculate synthetic rates and delay times of the most promising Type Ia Supernovae (SNe Ia) progenitors. We present and discuss evolutionary scenarios in which a white dwarf (WD) reaches the Chandrasekhar mass and potentially explodes in a SNe Ia. We consider Double Degenerate (DDS; merger of two WDs), Single Degenerate (SDS; WD accreting from H-rich companion), and AM Canum Venaticorum (AM CVn; WD accreting from He-rich companion) scenarios. The results are presented for two different star formation histories: burst (elliptical-like galaxies) and continuous (spiral-like galaxies). It is found that delay times for the DDS in our standard model (with common envelope efficiency α CE = 1) follow a power-law distribution. For the SDS we note a wide range of delay times, while AM CVn progenitors produce a short burst of SNe Ia at early times. The DDS median delay time falls between ∼0.5 and 1 Gyr; the SDS between ∼2 and 3 Gyr; and the AM CVn between ∼0.8 and 0.6 Gyr depending on the assumed α CE . For a Milky-Way-like (MW-like) galaxy, we estimate the rates of SNe Ia arising from different progenitors as: ∼10 -4 yr -1 for the SDS and AM CVn, and ∼10 -3 yr -1 for the DDS. We point out that only the rates for two merging carbon-oxygen WDs, the only systems found in the DDS, are consistent with the observed rates for typical MW-like spirals. We also note that DDS progenitors are the dominant population in elliptical galaxies. The fact that the delay time distribution for the DDS follows a power law implies more SNe Ia (per unit mass) in young rather than in aged populations. Our results do not exclude other scenarios, but strongly indicate that the DDS is the dominant channel generating SNe Ia in spiral galaxies, at least in the framework of our adopted evolutionary models. Since it is believed that WD mergers cannot produce a thermonuclear explosion given the current understanding of accreting WDs, either the

  2. Stability analysis of linear switching systems with time delays

    Li Ping; Zhong Shouming; Cui Jinzhong

    2009-01-01

    The issue of stability analysis of linear switching system with discrete and distributed time delays is studied in this paper. An appropriate switching rule is applied to guarantee the stability of the whole switching system. Our results use a Riccati-type Lyapunov functional under a condition on the time delay. So, switching systems with mixed delays are developed. A numerical example is given to illustrate the effectiveness of our results.

  3. Results of the deepest all-sky survey for continuous gravitational waves on LIGO S6 data running on the Einstein@Home volunteer distributed computing project

    Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acemese, F.; Ackley, K.; Adams, C.; Phythian-Adams, A.T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwa, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Arker, Bd.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Bejger, M.; Be, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, M.J.; Birney, R.; Biscans, S.; Bisht, A.; Bitoss, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Boer, M.; Bogaert, J.G.; Bogan, C.; Bohe, A.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Boutfanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, A.D.; Brown, D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, O.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, C.; Cahillane, C.; Bustillo, J. Calderon; Callister, T. A.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Diaz, J. Casanueva; Casentini, C.; Caudill, S.; Cavaglia, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Baiardi, L. Cerboni; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, D. S.; Charlton, P.; Chassande-Mottin, E.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S. S. Y.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P. -F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M., Jr.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J. -P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, Laura; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dasgupta, A.; Costa, C. F. Da Silva; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; De, S.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De laurentis, M.; Deleglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.A.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devine, R. C.; Dhurandhar, S.; Diaz, M. C.; Di Fiore, L.; Giovanni, M. Di; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Dreyer, R. W. P.; Driggers, J. C.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Egizenstein, H. -B.; Ehrens, P.; Eichholel, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, O.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Far, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Fenyvesi, E.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.M.; Fournier, J. -D.; Frasca, J. -D; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fritsche, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garuti, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Geng, P.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gi, K.; Glaetke, A.; Goetz, E.; Goetz, R.; Gondan, L.; Gonzalez, Idelmis G.; Castro, J. M. Gonzalez; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Lee-Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Granta, A.; Gras, S.; Cray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C. -J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, S.; Hennig, J.; Henry, J.A.; Heptonsta, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Hough, J.; Houston, E. A.; Howel, E. J.; Hu, Y. M.; Huang, O.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J. -M.; Isi, M.; Isogai, T.; Lyer, B. R.; Fzumi, K.; Jaccimin, T.; Jang, D.H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jian, L.; Jimenez-Forteza, F.; Johnson, W.; Jones, I.D.; Jones, R.; Jones, R.; Jonker, R. J. G.; Ju, L.; Wads, k; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kefelian, F.; Keh, M. S.; Keite, D.; Kelley, D. B.; Kells, W.; Kennedy, R.E.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chi-Woong; Kim, Chunglee; Kim, J.; Kim, K.; Kim, Namjun; Kim, W.; Kimbre, S. J.; King, E. J.; King, P. J.; Kisse, J. S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringe, V.; Krishnan, B.; Krolak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Laxen, M.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, K.H.; Lee, M.H.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Lewis, J. B.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Liick, H.; Lundgren, A. P.; Lynch, R.; Ivia, Y.; Machenschalk, B.; Maclnnis, M.; Macleod, D. M.; Magafia-Sandoval, F.; Zertuche, L. Magafia; Magee, R. M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Manse, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marka, S.; Marka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matiehard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mende, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Miche, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B.C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, S.D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P.G.; Mytidis, A.; Nardecehia, I.; Naticchioni, L.; Nayak, R. K.; Nedkova, K.; Nelemans, G.; Nelson, T. J. N.; Gutierrez-Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Hang, S.; Ohme, F.; Oliver, M.; Oppermann, P.; Ram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.S; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Perri, L. M.; Phelps, M.; Piccinni, . J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powel, J.; Prasad, J.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L. G.; Puncken, .; Punturo, M.; Purrer, PuppoM.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romanov, G.; Romie, J. H.; Rowan, RosiliskaS.; Ruggi, RiidigerP.; Ryan, K.; Sachdev, Perminder S; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Saulson, P. R.; Sauter, E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J; Schmidt, P.; Schnabe, R.; Schofield, R. M. S.; Schonbeck, A.; Schreiber, K.E.C.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T. J.; Shahriar, M. S.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Sielleez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, António Dias da; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, R. J. E.; Smith, N.D.; Smith, R. J. E.; Son, E. J.; Sorazus, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S. E.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sunil, Suns; Sutton, P. J.; Swinkels, B. L.; Szczepariczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tapai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, W.R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tomasi, Z.; Torres, C. V.; Tome, C.; Tot, D.; Travasso, F.; Traylor, G.; Trifire, D.; Tringali, M. C.; Trozz, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Valente, G.; Valdes, G.; van Bake, N.; Van Beuzekom, Martin; Van den Brand, J. F. J.; Van Den Broeck, C.F.F.; Vander-Hyde, D. C.; van der Schaaf, L.; Van Heilningen, J. V.; Van Vegge, A. A.; Vardaro, M.; Vass, S.; Vaslith, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P.J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J. -Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, MT; Walker, M.; Wallace, L.; Walsh, S.; Vvang, G.; Wang, O.; Wang, X.; Wiang, Y.; Ward, R. L.; Wiarner, J.; Was, M.; Weaver, B.; Wei, L. -W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Weliels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Williams, D.R.; Williamson, A. R.; Willis, J. L.; WilIke, B.; Wimmer, M. H.; Whinkler, W.; Wipf, C. C.; De Witte, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J.L.; Wu, D. S.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yu, H.; Yvert, M.; Zadrozny, A.; Zangrando, L.; Zanolin, M.; Zendri, J. P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S.J.; Zhu, X.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.

    2016-01-01

    We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the S6 LIGO science run. The search was possible thanks to the computing power provided by the volunteers of the Einstein@Home distributed computing project. We find no significant

  4. New models of radical polymerization with branching and scission predicting molecular weight distribution in tubular and series of continuous stirred tank reactors allowing for multiradicals and gelation

    Yaghini, N.; Iedema, P.D.

    2015-01-01

    Modeling of the mol. wt. distribution (MWD) of low-​d. Polyethylene (ldPE) has been carried out for a tubular reactor under realistic non-​isothermal conditions and for a series of CSTR's. The model allows for the existence of multiradicals and the occurrence of gelation. The deterministic model is

  5. Multi-scale modeling for prediction of distributed cellular properties in response to substrate spatial gradients in a continuously run microreactor

    Lencastre Fernandes, Rita; Krühne, Ulrich; Nopens, Ingmar

    2012-01-01

    microbioreactor is simulated. A multiscale model consisting of the coupling of a population balance model, a kinetic model and a flow model was developed in order to predict simultaneously local concentrations of substrate (glucose), product (ethanol) and biomass, as well as the local cell size distributions....

  6. On Network Coded Distributed Storage

    Cabrera Guerrero, Juan Alberto; Roetter, Daniel Enrique Lucani; Fitzek, Frank Hanns Paul

    2016-01-01

    systems typically rely on expensive infrastructure with centralized control to store, repair and access the data. This approach introduces a large delay for accessing and storing the data driven in part by a high RTT between users and the cloud. These characteristics are at odds with the massive increase......This paper focuses on distributed fog storage solutions, where a number of unreliable devices organize themselves in Peer-to-Peer (P2P) networks with the purpose to store reliably their data and that of other devices and/or local users and provide lower delay and higher throughput. Cloud storage...... of devices and generated data in coming years as well as the requirements of low latency in many applications. We focus on characterizing optimal solutions for maintaining data availability when nodes in the fog continuously leave the network. In contrast with state-of-the-art data repair formulations, which...

  7. Continuous Problem of Function Continuity

    Jayakody, Gaya; Zazkis, Rina

    2015-01-01

    We examine different definitions presented in textbooks and other mathematical sources for "continuity of a function at a point" and "continuous function" in the context of introductory level Calculus. We then identify problematic issues related to definitions of continuity and discontinuity: inconsistency and absence of…

  8. Linear measure functional differential equations with infinite delay

    Monteiro, G. (Giselle Antunes); Slavík, A.

    2014-01-01

    We use the theory of generalized linear ordinary differential equations in Banach spaces to study linear measure functional differential equations with infinite delay. We obtain new results concerning the existence, uniqueness, and continuous dependence of solutions. Even for equations with a finite delay, our results are stronger than the existing ones. Finally, we present an application to functional differential equations with impulses.

  9. Assessing delay discounting in mice

    Mitchell, Suzanne H.

    2014-01-01

    Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

  10. Prescription Drug Marketing Act of 1987; Prescription Drug Amendments of 1992; policies, requirements, and administrative procedures; delay of effective date. Final rule; delay of effective date.

    2004-02-23

    . Sec. 203.3(u) and 203.50 (21 CFR 203.3(u) and 203.50) until December 1, 2007 to allow stakeholders time to continue to move toward this goal. In addition, the further delay of the applicability of Sec. 203.3(q) to wholesale distribution of blood derivatives by health care entities is necessary to give the agency additional time to consider whether regulatory changes are appropriate and, if so, to initiate such changes.

  11. Estimating Delays In ASIC's

    Burke, Gary; Nesheiwat, Jeffrey; Su, Ling

    1994-01-01

    Verification is important aspect of process of designing application-specific integrated circuit (ASIC). Design must not only be functionally accurate, but must also maintain correct timing. IFA, Intelligent Front Annotation program, assists in verifying timing of ASIC early in design process. This program speeds design-and-verification cycle by estimating delays before layouts completed. Written in C language.

  12. Permissible Delay in Payments

    Yung-Fu Huang

    2007-01-01

    Full Text Available The main purpose of this paper wants to investigate the optimal retailer's lot-sizing policy with two warehouses under partially permissible delay in payments within the economic order quantity (EOQ framework. In this paper, we want to extend that fully permissible delay in payments to the supplier would offer the retailer partially permissible delay in payments. That is, the retailer must make a partial payment to the supplier when the order is received. Then the retailer must pay off the remaining balance at the end of the permissible delay period. In addition, we want to add the assumption that the retailer's storage space is limited. That is, the retailer will rent the warehouse to store these exceeding items when the order quantity is larger than retailer's storage space. Under these conditions, we model the retailer's inventory system as a cost minimization problem to determine the retailer's optimal cycle time and optimal order quantity. Three theorems are developed to efficiently determine the optimal replenishment policy for the retailer. Finally, numerical examples are given to illustrate these theorems and obtained a lot of managerial insights.

  13. Delayed neutrons in ANSTO

    Wall, T.

    1988-01-01

    Delayed neutron analysis carried out at the Australian Nuclear Scientific and Technology Organization facilities, provides a fast, high sensitivity, low cost, reliable method, particularly suitable for large batches of samples, and for non destructive analysis of a range of materials. While its main use has been in uranium exploration, other applications include archeological investigations, agriculture, oceanography and biology

  14. Delay-induced wave instabilities in single-species reaction-diffusion systems

    Otto, Andereas; Wang, Jian; Radons, Günter

    2017-11-01

    The Turing (wave) instability is only possible in reaction-diffusion systems with more than one (two) components. Motivated by the fact that a time delay increases the dimension of a system, we investigate the presence of diffusion-driven instabilities in single-species reaction-diffusion systems with delay. The stability of arbitrary one-component systems with a single discrete delay, with distributed delay, or with a variable delay is systematically analyzed. We show that a wave instability can appear from an equilibrium of single-species reaction-diffusion systems with fluctuating or distributed delay, which is not possible in similar systems with constant discrete delay or without delay. More precisely, we show by basic analytic arguments and by numerical simulations that fast asymmetric delay fluctuations or asymmetrically distributed delays can lead to wave instabilities in these systems. Examples, for the resulting traveling waves are shown for a Fisher-KPP equation with distributed delay in the reaction term. In addition, we have studied diffusion-induced instabilities from homogeneous periodic orbits in the same systems with variable delay, where the homogeneous periodic orbits are attracting resonant periodic solutions of the system without diffusion, i.e., periodic orbits of the Hutchinson equation with time-varying delay. If diffusion is introduced, standing waves can emerge whose temporal period is equal to the period of the variable delay.

  15. Global exponential stability and lag synchronization for delayed memristive fuzzy Cohen-Grossberg BAM neural networks with impulses.

    Yang, Wengui; Yu, Wenwu; Cao, Jinde; Alsaadi, Fuad E; Hayat, Tasawar

    2018-02-01

    This paper investigates the stability and lag synchronization for memristor-based fuzzy Cohen-Grossberg bidirectional associative memory (BAM) neural networks with mixed delays (asynchronous time delays and continuously distributed delays) and impulses. By applying the inequality analysis technique, homeomorphism theory and some suitable Lyapunov-Krasovskii functionals, some new sufficient conditions for the uniqueness and global exponential stability of equilibrium point are established. Furthermore, we obtain several sufficient criteria concerning globally exponential lag synchronization for the proposed system based on the framework of Filippov solution, differential inclusion theory and control theory. In addition, some examples with numerical simulations are given to illustrate the feasibility and validity of obtained results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Thermal Aware Floorplanning Incorporating Temperature Dependent Wire Delay Estimation

    Winther, AndreasThor; Liu, Wei; Nannarelli, Alberto

    2015-01-01

    Temperature has a negative impact on metal resistance and thus wire delay. In state-of-the-art VLSI circuits, large thermal gradients usually exist due to the uneven distribution of heat sources. The difference in wire temperature can lead to performance mismatch because wires of the same length...... can have different delay. Traditional floorplanning algorithms use wirelength to estimate wire performance. In this work, we show that this does not always produce a design with the shortest delay and we propose a floorplanning algorithm taking into account temperature dependent wire delay as one...

  17. Robust stability bounds for multi-delay networked control systems

    Seitz, Timothy; Yedavalli, Rama K.; Behbahani, Alireza

    2018-04-01

    In this paper, the robust stability of a perturbed linear continuous-time system is examined when controlled using a sampled-data networked control system (NCS) framework. Three new robust stability bounds on the time-invariant perturbations to the original continuous-time plant matrix are presented guaranteeing stability for the corresponding discrete closed-loop augmented delay-free system (ADFS) with multiple time-varying sensor and actuator delays. The bounds are differentiated from previous work by accounting for the sampled-data nature of the NCS and for separate communication delays for each sensor and actuator, not a single delay. Therefore, this paper expands the knowledge base in multiple inputs multiple outputs (MIMO) sampled-data time delay systems. Bounds are presented for unstructured, semi-structured, and structured perturbations.

  18. Topological Acoustic Delay Line

    Zhang, Zhiwang; Tian, Ye; Cheng, Ying; Wei, Qi; Liu, Xiaojun; Christensen, Johan

    2018-03-01

    Topological protected wave engineering in artificially structured media is at the frontier of ongoing metamaterials research that is inspired by quantum mechanics. Acoustic analogues of electronic topological insulators have recently led to a wealth of new opportunities in manipulating sound propagation with strikingly unconventional acoustic edge modes immune to backscattering. Earlier fabrications of topological insulators are characterized by an unreconfigurable geometry and a very narrow frequency response, which severely hinders the exploration and design of useful devices. Here we establish topologically protected sound in reconfigurable phononic crystals that can be switched on and off simply by rotating its three-legged "atoms" without altering the lattice structure. In particular, we engineer robust phase delay defects that take advantage of the ultrabroadband reflection-free sound propagation. Such topological delay lines serve as a paradigm in compact acoustic devices, interconnects, and electroacoustic integrated circuits.

  19. Delayed traumatic intracranial hematoma

    Tomita, Hiroki

    1984-01-01

    CT was performed serially within 24 hours after head injury in 64 patients having Glasgow Coma Scale of 14 or less or cranial fracture shown on roentgenogram. Delayed traumatic extradural hematoma was observed within 7-12 hours after head injury in 6 cases (9.4%). This was prominent in the frontal and occipital regions (67%). Good recovery was seen in 83.3%. Delayed traumatic intracerebral hematoma was observed within 6-24 hours after head injury in 17 cases (26.6%). This higher incidence was related to contre coup injury. Conservative treatment was possible in 14 of the 17 patients (82.4%), showing good recovery in 70%. (Namekawa, K.)

  20. Charge characteristics of humic and fulvic acids: comparative analysis by colloid titration and potentiometric titration with continuous pK-distribution function model.

    Bratskaya, S; Golikov, A; Lutsenko, T; Nesterova, O; Dudarchik, V

    2008-09-01

    Charge characteristics of humic and fulvic acids of a different origin (inshore soils, peat, marine sediments, and soil (lysimetric) waters) were evaluated by means of two alternative methods - colloid titration and potentiometric titration. In order to elucidate possible limitations of the colloid titration as an express method of analysis of low content of humic substances we monitored changes in acid-base properties and charge densities of humic substances with soil depth, fractionation, and origin. We have shown that both factors - strength of acidic groups and molecular weight distribution in humic and fulvic acids - can affect the reliability of colloid titration. Due to deviations from 1:1 stoichiometry in interactions of humic substances with polymeric cationic titrant, the colloid titration can underestimate total acidity (charge density) of humic substances with domination of weak acidic functional groups (pK>6) and high content of the fractions with molecular weight below 1kDa.

  1. Business continuity

    Breunhoelder, Gert

    2002-01-01

    This presentation deals with the following keypoints: Information Technology (IT) Business Continuity and Recovery essential for any business; lessons learned after Sept. 11 event; Detailed planning, redundancy and testing being the key elements for probability estimation of disasters

  2. Time-Delay Interferometry

    Massimo Tinto

    2014-08-01

    Full Text Available Equal-arm detectors of gravitational radiation allow phase measurements many orders of magnitude below the intrinsic phase stability of the laser injecting light into their arms. This is because the noise in the laser light is common to both arms, experiencing exactly the same delay, and thus cancels when it is differenced at the photo detector. In this situation, much lower level secondary noises then set the overall performance. If, however, the two arms have different lengths (as will necessarily be the case with space-borne interferometers, the laser noise experiences different delays in the two arms and will hence not directly cancel at the detector. In order to solve this problem, a technique involving heterodyne interferometry with unequal arm lengths and independent phase-difference readouts has been proposed. It relies on properly time-shifting and linearly combining independent Doppler measurements, and for this reason it has been called time-delay interferometry (TDI. This article provides an overview of the theory, mathematical foundations, and experimental aspects associated with the implementation of TDI. Although emphasis on the application of TDI to the Laser Interferometer Space Antenna (LISA mission appears throughout this article, TDI can be incorporated into the design of any future space-based mission aiming to search for gravitational waves via interferometric measurements. We have purposely left out all theoretical aspects that data analysts will need to account for when analyzing the TDI data combinations.

  3. Continuous tokamaks

    Peng, Y.K.M.

    1978-04-01

    A tokamak configuration is proposed that permits the rapid replacement of a plasma discharge in a ''burn'' chamber by another one in a time scale much shorter than the elementary thermal time constant of the chamber first wall. With respect to the chamber, the effective duty cycle factor can thus be made arbitrarily close to unity minimizing the cyclic thermal stress in the first wall. At least one plasma discharge always exists in the new tokamak configuration, hence, a continuous tokamak. By incorporating adiabatic toroidal compression, configurations of continuous tokamak compressors are introduced. To operate continuous tokamaks, it is necessary to introduce the concept of mixed poloidal field coils, which spatially groups all the poloidal field coils into three sets, all contributing simultaneously to inducing the plasma current and maintaining the proper plasma shape and position. Preliminary numerical calculations of axisymmetric MHD equilibria in continuous tokamaks indicate the feasibility of their continued plasma operation. Advanced concepts of continuous tokamaks to reduce the topological complexity and to allow the burn plasma aspect ratio to decrease for increased beta are then suggested

  4. Heterogeneous delay-induced asynchrony and resonance in a small-world neuronal network system

    Yu, Wen-Ting; Tang, Jun; Ma, Jun; Yang, Xianqing

    2016-06-01

    A neuronal network often involves time delay caused by the finite signal propagation time in a given biological network. This time delay is not a homogenous fluctuation in a biological system. The heterogeneous delay-induced asynchrony and resonance in a noisy small-world neuronal network system are numerically studied in this work by calculating synchronization measure and spike interval distribution. We focus on three different delay conditions: double-values delay, triple-values delay, and Gaussian-distributed delay. Our results show the following: 1) the heterogeneity in delay results in asynchronous firing in the neuronal network, and 2) maximum synchronization could be achieved through resonance given that the delay values are integer or half-integer times of each other.

  5. Delayed frost growth on jumping-drop superhydrophobic surfaces.

    Boreyko, Jonathan B; Collier, C Patrick

    2013-02-26

    Self-propelled jumping drops are continuously removed from a condensing superhydrophobic surface to enable a micrometric steady-state drop size. Here, we report that subcooled condensate on a chilled superhydrophobic surface are able to repeatedly jump off the surface before heterogeneous ice nucleation occurs. Frost still forms on the superhydrophobic surface due to ice nucleation at neighboring edge defects, which eventually spreads over the entire surface via an interdrop frost wave. The growth of this interdrop frost front is shown to be up to 3 times slower on the superhydrophobic surface compared to a control hydrophobic surface, due to the jumping-drop effect dynamically minimizing the average drop size and surface coverage of the condensate. A simple scaling model is developed to relate the success and speed of interdrop ice bridging to the drop size distribution. While other reports of condensation frosting on superhydrophobic surfaces have focused exclusively on liquid-solid ice nucleation for isolated drops, these findings reveal that the growth of frost is an interdrop phenomenon that is strongly coupled to the wettability and drop size distribution of the surface. A jumping-drop superhydrophobic condenser minimized frost formation relative to a conventional dropwise condenser in two respects: preventing heterogeneous ice nucleation by continuously removing subcooled condensate, and delaying frost growth by limiting the success of interdrop ice bridge formation.

  6. Isotopic composition and distribution of plutonium in northern South China Sea sediments revealed continuous release and transport of Pu from the Marshall Islands.

    Wu, Junwen; Zheng, Jian; Dai, Minhan; Huh, Chih-An; Chen, Weifang; Tagami, Keiko; Uchida, Shigeo

    2014-03-18

    The (239+240)Pu activities and (240)Pu/(239)Pu atom ratios in sediments of the northern South China Sea and its adjacent Pearl River Estuary were determined to examine the spatial and temporal variations of Pu inputs. We clarified that Pu in the study area is sourced from a combination of global fallout and close-in fallout from the Pacific Proving Grounds in the Marshall Islands where above-ground nuclear weapons testing was carried out during the period of 1952-1958. The latter source dominated the Pu input in the 1950s, as evidenced by elevated (240)Pu/(239)Pu atom ratios (>0.30) in a dated sediment core. Even after the 1950s, the Pacific Proving Grounds was still a dominant Pu source due to continuous transport of remobilized Pu from the Marshall Islands, about 4500 km away, along the North Equatorial Current followed by the transport of the Kuroshio current and its extension into the South China Sea through the Luzon Strait. Using a simple two end-member mixing model, we have quantified the contributions of Pu from the Pacific Proving Grounds to the northern South China Sea shelf and the Pearl River Estuary are 68% ± 1% and 30% ± 5%, respectively. This study also confirmed that there were no clear signals of Pu from the Fukushima Daiichi Nuclear Power Plant accident impacting the South China Sea.

  7. Continuous Dropout.

    Shen, Xu; Tian, Xinmei; Liu, Tongliang; Xu, Fang; Tao, Dacheng

    2017-10-03

    Dropout has been proven to be an effective algorithm for training robust deep networks because of its ability to prevent overfitting by avoiding the co-adaptation of feature detectors. Current explanations of dropout include bagging, naive Bayes, regularization, and sex in evolution. According to the activation patterns of neurons in the human brain, when faced with different situations, the firing rates of neurons are random and continuous, not binary as current dropout does. Inspired by this phenomenon, we extend the traditional binary dropout to continuous dropout. On the one hand, continuous dropout is considerably closer to the activation characteristics of neurons in the human brain than traditional binary dropout. On the other hand, we demonstrate that continuous dropout has the property of avoiding the co-adaptation of feature detectors, which suggests that we can extract more independent feature detectors for model averaging in the test stage. We introduce the proposed continuous dropout to a feedforward neural network and comprehensively compare it with binary dropout, adaptive dropout, and DropConnect on Modified National Institute of Standards and Technology, Canadian Institute for Advanced Research-10, Street View House Numbers, NORB, and ImageNet large scale visual recognition competition-12. Thorough experiments demonstrate that our method performs better in preventing the co-adaptation of feature detectors and improves test performance.

  8. On minimizing the maximum broadcast decoding delay for instantly decodable network coding

    Douik, Ahmed S.

    2014-09-01

    In this paper, we consider the problem of minimizing the maximum broadcast decoding delay experienced by all the receivers of generalized instantly decodable network coding (IDNC). Unlike the sum decoding delay, the maximum decoding delay as a definition of delay for IDNC allows a more equitable distribution of the delays between the different receivers and thus a better Quality of Service (QoS). In order to solve this problem, we first derive the expressions for the probability distributions of maximum decoding delay increments. Given these expressions, we formulate the problem as a maximum weight clique problem in the IDNC graph. Although this problem is known to be NP-hard, we design a greedy algorithm to perform effective packet selection. Through extensive simulations, we compare the sum decoding delay and the max decoding delay experienced when applying the policies to minimize the sum decoding delay and our policy to reduce the max decoding delay. Simulations results show that our policy gives a good agreement among all the delay aspects in all situations and outperforms the sum decoding delay policy to effectively minimize the sum decoding delay when the channel conditions become harsher. They also show that our definition of delay significantly improve the number of served receivers when they are subject to strict delay constraints.

  9. Stable transmission of radio frequency signals on fiber links using interferomectric delay sensing

    Wilcox, Russell B.; Byrd, J.M.; Doolittle, Lawrence; Huang, Gang; Staples, J.W.

    2009-01-01

    The authors demonstrate distribution of a 2850 MHz rf signal over stabilized optical fiber links. For a 2.2 km link they measure an rms drift of 19.4 fs over 60 h, and for a 200 m link an rms drift of 8.4 fs over 20 h. The rf signals are transmitted as amplitude modulation on a continuous optical carrier. Variations in the delay length are sensed using heterodyne interferometry and used to correct the rf phase. The system uses standard fiber telecommunications components.

  10. MRI demonstration of cortical laminar necrosis and delayed white matter injury in anoxic encephalopathy

    Sawada, H.; Udaka, F.; Seriu, N.; Shindou, K.; Kameyama, M.; Tsujimura, M.

    1990-01-01

    We performed serial radiological examinations on a patient with anoxic encephalopathy. In the early term after the anoxic insult, T1-weighted MRI revealed high signal intensity area distributed laminarly in the cerebral cortex and diffusely in the putamen, which were thought to refect the cortical necrosis and necrosis in the putamen. Single photon emission computed tomography using I-123 isopropylamphetamine showed persistent hypoperfusion in the arterial watershed zones. T2-weighted MRI performed several months after the anoxic episode revealed diffuse high-intensity lesions in the arterial watershed zones. These delayed-onset white matter lesions continued to extend over several months. (orig.)

  11. Global Exponential Stability of Delayed Cohen-Grossberg BAM Neural Networks with Impulses on Time Scales

    Yongkun Li

    2009-01-01

    Full Text Available Based on the theory of calculus on time scales, the homeomorphism theory, Lyapunov functional method, and some analysis techniques, sufficient conditions are obtained for the existence, uniqueness, and global exponential stability of the equilibrium point of Cohen-Grossberg bidirectional associative memory (BAM neural networks with distributed delays and impulses on time scales. This is the first time applying the time-scale calculus theory to unify the discrete-time and continuous-time Cohen-Grossberg BAM neural network with impulses under the same framework.

  12. Continuity theory

    Nel, Louis

    2016-01-01

    This book presents a detailed, self-contained theory of continuous mappings. It is mainly addressed to students who have already studied these mappings in the setting of metric spaces, as well as multidimensional differential calculus. The needed background facts about sets, metric spaces and linear algebra are developed in detail, so as to provide a seamless transition between students' previous studies and new material. In view of its many novel features, this book will be of interest also to mature readers who have studied continuous mappings from the subject's classical texts and wish to become acquainted with a new approach. The theory of continuous mappings serves as infrastructure for more specialized mathematical theories like differential equations, integral equations, operator theory, dynamical systems, global analysis, topological groups, topological rings and many more. In light of the centrality of the topic, a book of this kind fits a variety of applications, especially those that contribute to ...

  13. Periodicity and global exponential stability of generalized Cohen-Grossberg neural networks with discontinuous activations and mixed delays.

    Wang, Dongshu; Huang, Lihong

    2014-03-01

    In this paper, we investigate the periodic dynamical behaviors for a class of general Cohen-Grossberg neural networks with discontinuous right-hand sides, time-varying and distributed delays. By means of retarded differential inclusions theory and the fixed point theorem of multi-valued maps, the existence of periodic solutions for the neural networks is obtained. After that, we derive some sufficient conditions for the global exponential stability and convergence of the neural networks, in terms of nonsmooth analysis theory with generalized Lyapunov approach. Without assuming the boundedness (or the growth condition) and monotonicity of the discontinuous neuron activation functions, our results will also be valid. Moreover, our results extend previous works not only on discrete time-varying and distributed delayed neural networks with continuous or even Lipschitz continuous activations, but also on discrete time-varying and distributed delayed neural networks with discontinuous activations. We give some numerical examples to show the applicability and effectiveness of our main results. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Adaptation to delayed auditory feedback induces the temporal recalibration effect in both speech perception and production.

    Yamamoto, Kosuke; Kawabata, Hideaki

    2014-12-01

    We ordinarily speak fluently, even though our perceptions of our own voices are disrupted by various environmental acoustic properties. The underlying mechanism of speech is supposed to monitor the temporal relationship between speech production and the perception of auditory feedback, as suggested by a reduction in speech fluency when the speaker is exposed to delayed auditory feedback (DAF). While many studies have reported that DAF influences speech motor processing, its relationship to the temporal tuning effect on multimodal integration, or temporal recalibration, remains unclear. We investigated whether the temporal aspects of both speech perception and production change due to adaptation to the delay between the motor sensation and the auditory feedback. This is a well-used method of inducing temporal recalibration. Participants continually read texts with specific DAF times in order to adapt to the delay. Then, they judged the simultaneity between the motor sensation and the vocal feedback. We measured the rates of speech with which participants read the texts in both the exposure and re-exposure phases. We found that exposure to DAF changed both the rate of speech and the simultaneity judgment, that is, participants' speech gained fluency. Although we also found that a delay of 200 ms appeared to be most effective in decreasing the rates of speech and shifting the distribution on the simultaneity judgment, there was no correlation between these measurements. These findings suggest that both speech motor production and multimodal perception are adaptive to temporal lag but are processed in distinct ways.

  15. Apparatus for the measurement of the distribution of neutron flux (band and wire continuous recorders); Appareillage pour la mesure des repartitions de flux neutroniques (derouleurs a bandes et a fils)

    Derrien, H; Lemerle, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    The apparatus of which we describe the principles and the operation, makes it possible to know the thermal neutron flux distribution in a pile channel or along a fuel element by the measurement of the {beta} activity of continuous detectors. It is also possible thereby to show the presence of a very localised sudden discontinuity in the distribution curve. (authors) [French] Les appareils dont nous decrivons le principe et le fonctionnement, permettent de connaitre la repartition du flux de neutrons thermiques dans un canal de pile ou le long d'un element combustible, par la mesure de l'activite {beta} de detecteurs continus. Ils permettent en outre de mettre en evidence un accident brutal, tres localise, de la courbe de repartition. (auteurs)

  16. Delayed child-bearing.

    Johnson, Jo-Ann; Tough, Suzanne

    2012-01-01

    To provide an overview of delayed child-bearing and to describe the implications for women and health care providers. Delayed child-bearing, which has increased greatly in recent decades, is associated with an increased risk of infertility, pregnancy complications, and adverse pregnancy outcome. This guideline provides information that will optimize the counselling and care of Canadian women with respect to their reproductive choices. Maternal age is the most important determinant of fertility, and obstetric and perinatal risks increase with maternal age. Many women are unaware of the success rates or limitations of assisted reproductive technology and of the increased medical risks of delayed child-bearing, including multiple births, preterm delivery, stillbirth, and Caesarean section. This guideline provides a framework to address these issues. Studies published between 2000 and August 2010 were retrieved through searches of PubMed and the Cochrane Library using appropriate key words (delayed child-bearing, deferred pregnancy, maternal age, assisted reproductive technology, infertility, and multiple births) and MeSH terms (maternal age, reproductive behaviour, fertility). The Internet was also searched using similar key words, and national and international medical specialty societies were searched for clinical practice guidelines and position statements. Data were extracted based on the aims, sample, authors, year, and results. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). The Society of Obstetricians and Gynaecologists of Canada. RECOMMENDATIONS 1. Women who delay child-bearing are at increased risk of infertility. Prospective parents, especially women, should know that their fecundity and fertility begin to decline significantly after 32 years of age. Prospective parents should know that assisted reproductive technologies cannot guarantee a live birth or completely

  17. Delaying information search

    Yaniv Shani

    2012-11-01

    Full Text Available In three studies, we examined factors that may temporarily attenuate information search. People are generally curious and dislike uncertainty, which typically encourages them to look for relevant information. Despite these strong forces that promote information search, people sometimes deliberately delay obtaining valuable information. We find they may do so when they are concerned that the information might interfere with future pleasurable activities. Interestingly, the decision to search or to postpone searching for information is influenced not only by the value and importance of the information itself but also by well-being maintenance goals related to possible detrimental effects that negative knowledge may have on unrelated future plans.

  18. Continuation calculus

    Geron, B.; Geuvers, J.H.; de'Liguoro, U.; Saurin, A.

    2013-01-01

    Programs with control are usually modeled using lambda calculus extended with control operators. Instead of modifying lambda calculus, we consider a different model of computation. We introduce continuation calculus, or CC, a deterministic model of computation that is evaluated using only head

  19. Dynamics in a delayed-neural network

    Yuan Yuan

    2007-01-01

    In this paper, we consider a neural network of four identical neurons with time-delayed connections. Some parameter regions are given for global, local stability and synchronization using the theory of functional differential equations. The root distributions in the corresponding characteristic transcendental equation are analyzed, Pitchfork bifurcation, Hopf and equivariant Hopf bifurcations are investigated by revealing the center manifolds and normal forms. Numerical simulations are shown the agreements with the theoretical results

  20. Delayed neutrons in liquid metal spallation targets

    Ridikas, D.; Bokov, P.; David, J.C.; Dore, D.; Giacri, M.L.; Van Lauwe, A.; Plukiene, R.; Plukis, A.; Ignatiev, S.; Pankratov, D.

    2003-01-01

    The next generation spallation neutron sources, neutrino factories or RIB production facilities currently being designed and constructed around the world will increase the average proton beam power on target by a few orders of magnitude. Increased proton beam power results in target thermal hydraulic issues leading to new target designs, very often based on flowing liquid metal targets such as Hg, Pb, Pb-Bi. Radioactive nuclides produced in liquid metal targets are transported into hot cells, past electronics, into pumps with radiation sensitive components, etc. Besides the considerable amount of photon activity in the irradiated liquid metal, a significant amount of the delayed neutron precursor activity can be accumulated in the target fluid. The transit time from the front of a liquid metal target into areas, where delayed neutrons may be important, can be as short as a few seconds, well within one half-life of many delayed neutron precursors. Therefore, it is necessary to evaluate the total neutron flux (including delayed neutrons) as a function of time and determine if delayed neutrons contribute significantly to the dose rate. In this study the multi-particle transport code MCNPX combined with the material evolution program CINDER'90 will be used to evaluate the delayed neutron flux and spectra. The following scientific issues will be addressed in this paper: - Modeling of a typical geometry of the liquid metal spallation target; - Predictions of the prompt neutron fluxes, fission fragment and spallation product distributions; - Comparison of the above parameters with existing experimental data; - Time-dependent calculations of delayed neutron precursors; - Neutron flux estimates due to the prompt and delayed neutron emission; - Proposal of an experimental program to measure delayed neutron spectra from high energy spallation-fission reactions. The results of this study should be directly applicable in the design study of the European MegaPie (1 MW

  1. Vehicle barrier with access delay

    Swahlan, David J; Wilke, Jason

    2013-09-03

    An access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools.

  2. Continuous Reinforced Concrete Beams

    Hoang, Cao Linh; Nielsen, Mogens Peter

    1996-01-01

    This report deals with stress and stiffness estimates of continuous reinforced concrete beams with different stiffnesses for negative and positive moments e.g. corresponding to different reinforcement areas in top and bottom. Such conditions are often met in practice.The moment distribution...

  3. Delayed rule following.

    Schmitt, D R

    2001-01-01

    Although the elements of a fully stated rule (discriminative stimulus [S(D)], some behavior, and a consequence) can occur nearly contemporaneously with the statement of the rule, there is often a delay between the rule statement and the S(D). The effects of this delay on rule following have not been studied in behavior analysis, but they have been investigated in rule-like settings in the areas of prospective memory (remembering to do something in the future) and goal pursuit. Discriminative events for some behavior can be event based (a specific setting stimulus) or time based. The latter are more demanding with respect to intention following and show age-related deficits. Studies suggest that the specificity with which the components of a rule (termed intention) are stated has a substantial effect on intention following, with more detailed specifications increasing following. Reminders of an intention, too, are most effective when they refer specifically to both the behavior and its occasion. Covert review and written notes are two effective strategies for remembering everyday intentions, but people who use notes appear not to be able to switch quickly to covert review. By focusing on aspects of the setting and rule structure, research on prospective memory and goal pursuit expands the agenda for a more complete explanation of rule effects.

  4. Pseudotumoral delayed cerebral radionecrosis

    Ciaudo-Lacroix, C.; Lapresle, J.

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. γEG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed [fr

  5. Pseudotumoral delayed cerebral radionecrosis

    Ciaudo-Lacroix, C; Lapresle, J [Centre Hospitalier de Bicetre, 94 - Le Kremlin-Bicetre (France)

    1985-01-01

    A 60 year-old woman with a scalp epithelioma underwent radiotherapy, the dose being 57 Gray. A first epileptic seizure occurred twenty months later. Neurological examination revealed signs of left hemisphere involvement. ..gamma..EG, angiography, CT scans, demonstrated a pseudotumoral avascular process. On account of the localisation, the patient being right-handed, no surgical procedure was performed. In spite of corticotherapy and anticonvulsive treatment, seizures recurred and neurological signs slowly progressed. The patient died, 22 months after the first seizure, of an associated disseminated carcinoma with cachexia. Neuropathological examination showed a massive lesion presenting all the features of delayed radionecrosis in the left hemisphere: situated mainly in the white matter; numerous vascular abnormalities; wide-spread demyelination; disappearance of oligoglial cells. The Authors recall the clinical and anatomical aspects of this condition for which the only successful treatment is surgical removal when location and size of the lesion permit. Finally, the mechanisms which have been proposed to explain this delayed cerebral radionecrosis are discussed.

  6. An Empirical Study of Synchrophasor Communication Delay in a Utility TCP/IP Network

    Zhu, Kun; Chenine, Moustafa; Nordström, Lars; Holmström, Sture; Ericsson, Göran

    2013-07-01

    Although there is a plethora of literature dealing with Phasor Measurement Unit (PMU) communication delay, there has not been any effort made to generalize empirical delay results by identifying the distribution with the best fit. The existing studies typically assume a distribution or simply build on analogies to communication network routing delay. Specifically, this study provides insight into the characterization of the communication delay of both unprocessed PMU data and synchrophasors sorted by a Phasor Data Concentrator (PDC). The results suggest that a bi-modal distribution containing two normal distributions offers the best fit of the delay of the unprocessed data, whereas the delay profile of the sorted synchrophasors resembles a normal distribution based on these results, the possibility of evaluating the reliability of a synchrophasor application with respect to a particular choice of PDC timeout is discussed.

  7. Improved work zone design guidelines and enhanced model of travel delays in work zones : Phase I, portability and scalability of interarrival and service time probability distribution functions for different locations in Ohio and the establishment of impr

    2006-01-01

    The project focuses on two major issues - the improvement of current work zone design practices and an analysis of : vehicle interarrival time (IAT) and speed distributions for the development of a digital computer simulation model for : queues and t...

  8. Continuation calculus

    Bram Geron

    2013-09-01

    Full Text Available Programs with control are usually modeled using lambda calculus extended with control operators. Instead of modifying lambda calculus, we consider a different model of computation. We introduce continuation calculus, or CC, a deterministic model of computation that is evaluated using only head reduction, and argue that it is suitable for modeling programs with control. It is demonstrated how to define programs, specify them, and prove them correct. This is shown in detail by presenting in CC a list multiplication program that prematurely returns when it encounters a zero. The correctness proof includes termination of the program. In continuation calculus we can model both call-by-name and call-by-value. In addition, call-by-name functions can be applied to call-by-value results, and conversely.

  9. Modelling biochemical networks with intrinsic time delays: a hybrid semi-parametric approach

    Oliveira Rui

    2010-09-01

    Full Text Available Abstract Background This paper presents a method for modelling dynamical biochemical networks with intrinsic time delays. Since the fundamental mechanisms leading to such delays are many times unknown, non conventional modelling approaches become necessary. Herein, a hybrid semi-parametric identification methodology is proposed in which discrete time series are incorporated into fundamental material balance models. This integration results in hybrid delay differential equations which can be applied to identify unknown cellular dynamics. Results The proposed hybrid modelling methodology was evaluated using two case studies. The first of these deals with dynamic modelling of transcriptional factor A in mammalian cells. The protein transport from the cytosol to the nucleus introduced a delay that was accounted for by discrete time series formulation. The second case study focused on a simple network with distributed time delays that demonstrated that the discrete time delay formalism has broad applicability to both discrete and distributed delay problems. Conclusions Significantly better prediction qualities of the novel hybrid model were obtained when compared to dynamical structures without time delays, being the more distinctive the more significant the underlying system delay is. The identification of the system delays by studies of different discrete modelling delays was enabled by the proposed structure. Further, it was shown that the hybrid discrete delay methodology is not limited to discrete delay systems. The proposed method is a powerful tool to identify time delays in ill-defined biochemical networks.

  10. Generation of wideband chaos with suppressed time-delay signature by delayed self-interference.

    Wang, Anbang; Yang, Yibiao; Wang, Bingjie; Zhang, Beibei; Li, Lei; Wang, Yuncai

    2013-04-08

    We demonstrate experimentally and numerically a method using the incoherent delayed self-interference (DSI) of chaotic light from a semiconductor laser with optical feedback to generate wideband chaotic signal. The results show that, the DSI can eliminate the domination of laser relaxation oscillation existing in the chaotic laser light and therefore flatten and widen the power spectrum. Furthermore, the DSI depresses the time-delay signature induced by external cavity modes and improves the symmetry of probability distribution by more than one magnitude. We also experimentally show that this DSI signal is beneficial to the random number generation.

  11. Stability and delay sensitivity of neutral fractional-delay systems.

    Xu, Qi; Shi, Min; Wang, Zaihua

    2016-08-01

    This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

  12. Design and implementation of high-precision and low-jitter programmable delay circuitry

    Gao Yuan; Cui Ke; Zhang Hongfei; Luo Chunli; Yang Dongxu; Liang Hao; Wang Jian

    2011-01-01

    A programmable delay circuit design which has characteristics of high-precision, low-jitter, wide-programmable-range and low power is introduced. The delay circuitry uses the scheme which has two parts: the coarse delay and the fine delay that could be controlled separately. Using different coarse delay chip can reach different maximum programmable range. And the fine delay programmable chip has the minimum step which is down to 10 ps. The whole circuitry jitter will be less than 100 ps. The design has been successfully applied in Quantum Key Distribution experiment. (authors)

  13. Optimal Control for Stochastic Delay Evolution Equations

    Meng, Qingxin, E-mail: mqx@hutc.zj.cn [Huzhou University, Department of Mathematical Sciences (China); Shen, Yang, E-mail: skyshen87@gmail.com [York University, Department of Mathematics and Statistics (Canada)

    2016-08-15

    In this paper, we investigate a class of infinite-dimensional optimal control problems, where the state equation is given by a stochastic delay evolution equation with random coefficients, and the corresponding adjoint equation is given by an anticipated backward stochastic evolution equation. We first prove the continuous dependence theorems for stochastic delay evolution equations and anticipated backward stochastic evolution equations, and show the existence and uniqueness of solutions to anticipated backward stochastic evolution equations. Then we establish necessary and sufficient conditions for optimality of the control problem in the form of Pontryagin’s maximum principles. To illustrate the theoretical results, we apply stochastic maximum principles to study two examples, an infinite-dimensional linear-quadratic control problem with delay and an optimal control of a Dirichlet problem for a stochastic partial differential equation with delay. Further applications of the two examples to a Cauchy problem for a controlled linear stochastic partial differential equation and an optimal harvesting problem are also considered.

  14. Delayed breast implant reconstruction

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... of radiation therapy was associated with a non-significantly increased risk of reoperation after both 1-stage (HR = 1.4; 95% CI: 0.7-2.5) and 2-stage (HR = 1.6; 95% CI: 0.9-3.1) procedures. Reconstruction failure was highest (13.2%) in the 2-stage procedures with a history of radiation therapy. Breast...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  15. Delay tolerant networks

    Gao, Longxiang; Luan, Tom H

    2015-01-01

    This brief presents emerging and promising communication methods for network reliability via delay tolerant networks (DTNs). Different from traditional networks, DTNs possess unique features, such as long latency and unstable network topology. As a result, DTNs can be widely applied to critical applications, such as space communications, disaster rescue, and battlefield communications. The brief provides a complete investigation of DTNs and their current applications, from an overview to the latest development in the area. The core issue of data forward in DTNs is tackled, including the importance of social characteristics, which is an essential feature if the mobile devices are used for human communication. Security and privacy issues in DTNs are discussed, and future work is also discussed.

  16. Electrically tunable photonic true-time-delay line.

    Barmenkov, Yuri O; Cruz, José Luis; Díez, Antonio; Andrés, Miguel V

    2010-08-16

    We present a new application of the acousto-optic superlattice modulation of a fiber Bragg grating based on the dynamic phase and group delay properties of this fiber-optic component. We demonstrate a tunable photonic true-time-delay line based on the group delay change of the light reflected from the grating sidebands. The delay is electrically tuned by adjusting the voltage applied to a piezoelectric transducer that generates the acoustic wave propagating along the grating. In our experiments, a true-time delay of 400 ps is continuously adjusted (300 ps within the 3 dB amplitude range of the first sideband), using a 12 cm long uniform grating.

  17. Diagnosis delay in Libyan female breast cancer.

    Ermiah, Eramah; Abdalla, Fathi; Buhmeida, Abdelbaset; Larbesh, Entesar; Pyrhönen, Seppo; Collan, Yrjö

    2012-08-21

    To study the diagnosis delay and its impact on stage of disease among women with breast cancer on Libya. 200 women, aged 22 to 75 years with breast cancer diagnosed during 2008-2009 were interviewed about the period from the first symptoms to the final histological diagnosis of breast cancer. This period (diagnosis time) was categorized into 3 periods: 6 months. If diagnosis time was longer than 3 months, the diagnosis was considered delayed (diagnosis delay). Consultation time was the time taken to visit the general practitioner after the first symptoms. Retrospective preclinical and clinical data were collected on a form (questionnaire) during an interview with each patient and from medical records. The median of diagnosis time was 7.5 months. Only 30.0% of patients were diagnosed within 3 months after symptoms. 14% of patients were diagnosed within 3-6 months and 56% within a period longer than 6 months. A number of factors predicted diagnosis delay: Symptoms were not considered serious in 27% of patients. Alternative therapy (therapy not associated with cancer) was applied in 13.0% of the patients. Fear and shame prevented the visit to the doctor in 10% and 4.5% of patients, respectively. Inappropriate reassurance that the lump was benign was an important reason for prolongation of the diagnosis time. Diagnosis delay was associated with initial breast symptom(s) that did not include a lump (p diagnosis, the clinical stage distribution was as follows: 9.0% stage I, 25.5% stage II, 54.0% stage III and 11.5% stage IV.Diagnosis delay was associated with bigger tumour size (p Diagnosis delay is very serious problem in Libya. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer awareness and training of general practitioners to reduce breast cancer mortality by promoting early detection. The treatment guidelines should pay more attention to the early phases of breast

  18. Mitotic delay of irradiated cells and its connection with quantity of radiation injuries

    Lobachevskij, P.N.; Fominykh, E.V.

    1989-01-01

    The study is dedicated to development of mathematical approach to interpret radiation-induced mitosic delay. An assumption is made that mitotic delay is conditioned by discrete injuries distributed in cells according to stochasticity of interaction of radiation and target substance. It is supposed to consider the problem on injuries nature causing mitotic delay and to use the developed method for accounting the effect of radiation-induced mitotic delay on registered chromosomal aberration yield. 10 refs.; 2 figs.; 3 tabs

  19. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays

    Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and di...

  20. Heterogeneity of time delays determines synchronization of coupled oscillators.

    Petkoski, Spase; Spiegler, Andreas; Proix, Timothée; Aram, Parham; Temprado, Jean-Jacques; Jirsa, Viktor K

    2016-07-01

    Network couplings of oscillatory large-scale systems, such as the brain, have a space-time structure composed of connection strengths and signal transmission delays. We provide a theoretical framework, which allows treating the spatial distribution of time delays with regard to synchronization, by decomposing it into patterns and therefore reducing the stability analysis into the tractable problem of a finite set of delay-coupled differential equations. We analyze delay-structured networks of phase oscillators and we find that, depending on the heterogeneity of the delays, the oscillators group in phase-shifted, anti-phase, steady, and non-stationary clusters, and analytically compute their stability boundaries. These results find direct application in the study of brain oscillations.

  1. Location Estimation using Delayed Measurements

    Bak, Martin; Larsen, Thomas Dall; Nørgård, Peter Magnus

    1998-01-01

    When combining data from various sensors it is vital to acknowledge possible measurement delays. Furthermore, the sensor fusion algorithm, often a Kalman filter, should be modified in order to handle the delay. The paper examines different possibilities for handling delays and applies a new techn...... technique to a sensor fusion system for estimating the location of an autonomous guided vehicle. The system fuses encoder and vision measurements in an extended Kalman filter. Results from experiments in a real environment are reported...

  2. Continuous and distributed systems theory and applications

    Sadovnichiy, Victor

    2014-01-01

    In this volume, the authors close the gap between abstract mathematical approaches, such as abstract algebra, number theory, nonlinear functional analysis, partial differential equations, methods of nonlinear and multi-valued analysis, on the one hand, and practical applications in nonlinear mechanics, decision making theory and control theory on the other. Readers will also benefit from the presentation of modern mathematical modeling methods for the numerical solution of complicated engineering problems in hydromechanics, geophysics and mechanics of continua. This compilation will be of interest to mathematicians and engineers working at the interface of these field. It presents selected works of the open seminar series of Lomonosov Moscow State University and the National Technical University of Ukraine “Kyiv Polytechnic Institute”. The authors come from Germany, Italy, Spain, Russia, Ukraine, and the USA.

  3. Robotic reactions: Delay-induced patterns in autonomous vehicle systems

    Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

    2010-02-01

    Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation.

  4. Robotic reactions: delay-induced patterns in autonomous vehicle systems.

    Orosz, Gábor; Moehlis, Jeff; Bullo, Francesco

    2010-02-01

    Fundamental design principles are presented for vehicle systems governed by autonomous cruise control devices. By analyzing the corresponding delay differential equations, it is shown that for any car-following model short-wavelength oscillations can appear due to robotic reaction times, and that there are tradeoffs between the time delay and the control gains. The analytical findings are demonstrated on an optimal velocity model using numerical continuation and numerical simulation.

  5. Dyadic distributions

    Golubov, B I

    2007-01-01

    On the basis of the concept of pointwise dyadic derivative dyadic distributions are introduced as continuous linear functionals on the linear space D d (R + ) of infinitely differentiable functions compactly supported by the positive half-axis R + together with all dyadic derivatives. The completeness of the space D' d (R + ) of dyadic distributions is established. It is shown that a locally integrable function on R + generates a dyadic distribution. In addition, the space S d (R + ) of infinitely dyadically differentiable functions on R + rapidly decreasing in the neighbourhood of +∞ is defined. The space S' d (R + ) of dyadic distributions of slow growth is introduced as the space of continuous linear functionals on S d (R + ). The completeness of the space S' d (R + ) is established; it is proved that each integrable function on R + with polynomial growth at +∞ generates a dyadic distribution of slow growth. Bibliography: 25 titles.

  6. Systematic of delayed neutron parameters

    Isaev, S.G.; Piksaikin, V.M.

    2000-01-01

    The experimental studies of the energy dependence of the delayed neutron (DN) parameters for various fission systems has shown that the behaviour of a some combination of delayed neutron parameters has a similar features. On the basis of this findings the systematics of delayed neutron experimental data for thorium, uranium, plutonium and americium isotopes have been investigated with the purpose to find a correlation of DN parameters with characteristics of fissioning system as well as a correlation between the delayed neutron parameters themselves. It was presented the preliminary results which were obtained during study the physics interpretation of the results [ru

  7. Development of a statistically based access delay timeline methodology.

    Rivera, W. Gary; Robinson, David Gerald; Wyss, Gregory Dane; Hendrickson, Stacey M. Langfitt

    2013-02-01

    The charter for adversarial delay is to hinder access to critical resources through the use of physical systems increasing an adversarys task time. The traditional method for characterizing access delay has been a simple model focused on accumulating times required to complete each task with little regard to uncertainty, complexity, or decreased efficiency associated with multiple sequential tasks or stress. The delay associated with any given barrier or path is further discounted to worst-case, and often unrealistic, times based on a high-level adversary, resulting in a highly conservative calculation of total delay. This leads to delay systems that require significant funding and personnel resources in order to defend against the assumed threat, which for many sites and applications becomes cost prohibitive. A new methodology has been developed that considers the uncertainties inherent in the problem to develop a realistic timeline distribution for a given adversary path. This new methodology incorporates advanced Bayesian statistical theory and methodologies, taking into account small sample size, expert judgment, human factors and threat uncertainty. The result is an algorithm that can calculate a probability distribution function of delay times directly related to system risk. Through further analysis, the access delay analyst or end user can use the results in making informed decisions while weighing benefits against risks, ultimately resulting in greater system effectiveness with lower cost.

  8. Programmable delay unit incorporating a semi-custom integrated circuit

    Linstadt, E.

    1985-04-01

    The synchronization of SLC accelerator control and monitoring functions is realized by a CAMAC module, the PDU II (Programmable Delay Unit II, SLAC 253-002), which includes a semi-custom gate array integrated circuit. The PDU II distributes 16 channels of independently programmable delayed pulses to other modules within the same CAMAC crate. The delays are programmable in increments of 8.4 ns. Functional descriptions of both the module and the semi-custom integrated circuit used to generate the output pulses are given

  9. New Delay-Dependent Stability Criteria for Uncertain Neutral Systems with Mixed Time-Varying Delays and Nonlinear Perturbations

    Hamid Reza Karimi

    2009-01-01

    Full Text Available The problem of stability analysis for a class of neutral systems with mixed time-varying neutral, discrete and distributed delays and nonlinear parameter perturbations is addressed. By introducing a novel Lyapunov-Krasovskii functional and combining the descriptor model transformation, the Leibniz-Newton formula, some free-weighting matrices, and a suitable change of variables, new sufficient conditions are established for the stability of the considered system, which are neutral-delay-dependent, discrete-delay-range-dependent, and distributed-delay-dependent. The conditions are presented in terms of linear matrix inequalities (LMIs and can be efficiently solved using convex programming techniques. Two numerical examples are given to illustrate the efficiency of the proposed method.

  10. Predictors of Delayed Healthcare Seeking Among American Muslim Women.

    Vu, Milkie; Azmat, Alia; Radejko, Tala; Padela, Aasim I

    2016-06-01

    Delayed care seeking is associated with adverse health outcomes. For Muslim women, delayed care seeking might include religion-related motivations, such as a preference for female clinicians, concerns about preserving modesty, and fatalistic beliefs. Our study assesses associations between religion-related factors and delayed care seeking due to a perceived lack of female clinicians. Surveys were distributed to Muslim women attending mosque and community events in Chicago. Survey items included measures of religiosity, religious fatalism, discrimination, modesty, and alternative medicine utilization and worship practices. The outcome measure asked for levels of agreement to the statement "I have delayed seeking medical care when no woman doctor is available to see me." Two hundred fifty-four women completed the survey with nearly equal numbers of African Americans (26%), Arab Americans (33%), and South Asians (33%). Fifty-three percent reported delays in care seeking due to a perceived lack of female clinicians. In multivariate analysis adjusting for sociodemographic factors, higher religiosity (odds ratio [OR] = 5.2, p 20 years (OR = 0.22, p American Muslim women reported delays in care seeking due to a perceived lack of female clinicians. Women with higher levels of modesty and self-rated religiosity had higher odds of delaying care. Women who had lived in the United States for longer durations had lower odds of delaying care. Our research highlights the need for gender-concordant providers and culturally sensitive care for American Muslims.

  11. Delayed Auditory Feedback and Movement

    Pfordresher, Peter Q.; Dalla Bella, Simone

    2011-01-01

    It is well known that timing of rhythm production is disrupted by delayed auditory feedback (DAF), and that disruption varies with delay length. We tested the hypothesis that disruption depends on the state of the movement trajectory at the onset of DAF. Participants tapped isochronous rhythms at a rate specified by a metronome while hearing DAF…

  12. #FakeNobelDelayReasons

    2013-01-01

    Tuesday’s hour-long delay of the Nobel Prize in Physics announcement was (and still is) quite the cause for speculation. But on the Twittersphere, it was simply the catalyst for some fantastic puns, so-bad-they're-good physics jokes and other shenanigans. Here are some of our favourite #FakeNobelDelayReasons.    

  13. Picosecond resolution programmable delay line

    Suchenek, Mariusz

    2009-01-01

    The note presents implementation of a programmable delay line for digital signals. The tested circuit has a subnanosecond delay range programmable with a resolution of picoseconds. Implementation of the circuit was based on low-cost components, easily available on the market. (technical design note)

  14. Project delay analysis of HRSG

    Silvianita; Novega, A. S.; Rosyid, D. M.; Suntoyo

    2017-08-01

    Completion of HRSG (Heat Recovery Steam Generator) fabrication project sometimes is not sufficient with the targeted time written on the contract. The delay on fabrication process can cause some disadvantages for fabricator, including forfeit payment, delay on HRSG construction process up until HRSG trials delay. In this paper, the author is using semi quantitative on HRSG pressure part fabrication delay with configuration plant 1 GT (Gas Turbine) + 1 HRSG + 1 STG (Steam Turbine Generator) using bow-tie analysis method. Bow-tie analysis method is a combination from FTA (Fault tree analysis) and ETA (Event tree analysis) to develop the risk matrix of HRSG. The result from FTA analysis is use as a threat for preventive measure. The result from ETA analysis is use as impact from fabrication delay.

  15. Delayed radiation neuropathy

    Nagashima, T.; Miyamoto, K.; Beppu, H.; Hirose, K.; Yamada, K. (Tokyo Metropolitan Neurological Hospital (Japan))

    1981-07-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author).

  16. Delayed radiation neuropathy

    Nagashima, Toshiko; Miyamoto, Kazuto; Beppu, Hirokuni; Hirose, Kazuhiko; Yamada, Katsuhiro

    1981-01-01

    A case of cervical plexus neuropathy was reported in association with chronic radio-dermatitis, myxedema with thyroid adenoma and epiglottic tumor. A 38-year-old man has noticed muscle weakness and wasting of the right shoulder girdle since age 33. A detailed history taking revealed a previous irradiation to the neck because of the cervical lymphadenopathy at age 10 (X-ray 3,000 rads), keroid skin change at age 19, obesity and edema since 26, and hoarseness at 34. Laryngoscopic examination revealed a tumor on the right vocal cord, diagnosed as benign papilloma by histological study. In addition, there were chronic radio-dermatitis around the neck, primary hypothyroidism with a benign functioning adenoma on the right lobe of the thyroid, the right phrenic nerve palsy and the right recurrent nerve palsy. All these lesions were considered to be the late sequellae of radiation to the neck in childhood. Other neurological signs were weakness and amyotrophy of the right shoulder girdle with patchy sensory loss, and areflexia of the right arm. Gross power was fairly well preserved in the right hand. EMG showed neurogenic changes in the tested muscles, suggesting a peripheral nerve lesion. Nerve conduction velocities were normal. No abnormal findings were revealed by myelography and spinal CT. The neurological findings of the patient were compatible with the diagnosis of middle cervical plexus palsy apparently due to late radiation effect. In the literature eight cases of post-radiation neuropathy with a long latency have been reported. The present case with the longest latency after the radiation should be included in the series of the reported cases of ''delayed radiation neuropathy.'' (author)

  17. Continuous Markovian Logics

    Mardare, Radu Iulian; Cardelli, Luca; Larsen, Kim Guldstrand

    2012-01-01

    Continuous Markovian Logic (CML) is a multimodal logic that expresses quantitative and qualitative properties of continuous-time labelled Markov processes with arbitrary (analytic) state-spaces, henceforth called continuous Markov processes (CMPs). The modalities of CML evaluate the rates...... of the exponentially distributed random variables that characterize the duration of the labeled transitions of a CMP. In this paper we present weak and strong complete axiomatizations for CML and prove a series of metaproperties, including the finite model property and the construction of canonical models. CML...... characterizes stochastic bisimilarity and it supports the definition of a quantified extension of the satisfiability relation that measures the "compatibility" between a model and a property. In this context, the metaproperties allows us to prove two robustness theorems for the logic stating that one can...

  18. Comment on the paper "Thermoluminescence glow-curve deconvolution functions for mixed order of kinetics and continuous trap distribution by G. Kitis, J.M. Gomez-Ros, Nuclear Instruments and Methods in Physics Research A 440, 2000, pp 224-231"

    Kazakis, Nikolaos A.

    2018-01-01

    The present comment concerns the correct presentation of an algorithm proposed in the above paper for the glow-curve deconvolution in the case of continuous distribution of trapping states. Since most researchers would use directly the proposed algorithm as published, they should be notified of its correct formulation during the fitting of TL glow curves of materials with continuous trap distribution using this Equation.

  19. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don’t include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results. PMID:28931066

  20. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

    Chen, Chuan; Li, Lixiang; Peng, Haipeng; Yang, Yixian

    2017-01-01

    Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs) with both discrete delay and distributed delay (mixed delays). By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

  1. Finite time synchronization of memristor-based Cohen-Grossberg neural networks with mixed delays.

    Chuan Chen

    Full Text Available Finite time synchronization, which means synchronization can be achieved in a settling time, is desirable in some practical applications. However, most of the published results on finite time synchronization don't include delays or only include discrete delays. In view of the fact that distributed delays inevitably exist in neural networks, this paper aims to investigate the finite time synchronization of memristor-based Cohen-Grossberg neural networks (MCGNNs with both discrete delay and distributed delay (mixed delays. By means of a simple feedback controller and novel finite time synchronization analysis methods, several new criteria are derived to ensure the finite time synchronization of MCGNNs with mixed delays. The obtained criteria are very concise and easy to verify. Numerical simulations are presented to demonstrate the effectiveness of our theoretical results.

  2. Discretization-induced delays and their role in the dynamics

    Ramani, A; Grammaticos, B; Satsuma, J; Willox, R

    2008-01-01

    We show that a discretization of a continuous system may entail 'hidden' delays and thus introduce instabilities. In this case, while the continuous system has an attractive fixed point, the instabilities present in the equivalent discrete one may lead to the appearance of a limit cycle. We explain that it is possible, thanks to the proper staggering of the discrete variables, to eliminate the hidden delay. However, in general, other instabilities may appear in the discrete system which can even lead to chaotic behaviour

  3. Attosecond Delays in Molecular Photoionization.

    Huppert, Martin; Jordan, Inga; Baykusheva, Denitsa; von Conta, Aaron; Wörner, Hans Jakob

    2016-08-26

    We report measurements of energy-dependent photoionization delays between the two outermost valence shells of N_{2}O and H_{2}O. The combination of single-shot signal referencing with the use of different metal foils to filter the attosecond pulse train enables us to extract delays from congested spectra. Remarkably large delays up to 160 as are observed in N_{2}O, whereas the delays in H_{2}O are all smaller than 50 as in the photon-energy range of 20-40 eV. These results are interpreted by developing a theory of molecular photoionization delays. The long delays measured in N_{2}O are shown to reflect the population of molecular shape resonances that trap the photoelectron for a duration of up to ∼110 as. The unstructured continua of H_{2}O result in much smaller delays at the same photon energies. Our experimental and theoretical methods make the study of molecular attosecond photoionization dynamics accessible.

  4. Atrial fibrillation and delayed gastric emptying.

    Isadora C Botwinick

    Full Text Available BACKGROUND: Atrial fibrillation and delayed gastric emptying (DGE are common after pancreaticoduodenectomy. Our aim was to investigate a potential relationship between atrial fibrillation and DGE, which we defined as failure to tolerate a regular diet by the 7(th postoperative day. METHODS: We performed a retrospective chart review of 249 patients who underwent pancreaticoduodenectomy at our institution between 2000 and 2009. Data was analyzed with Fisher exact test for categorical variables and Mann-Whitney U or unpaired T-test for continuous variables. RESULTS: Approximately 5% of the 249 patients included in the analysis experienced at least one episode of postoperative atrial fibrillation. Median age of patients with atrial fibrillation was 74 years, compared with 66 years in patients without atrial fibrillation (p = 0.0005. Patients with atrial fibrillation were more likely to have a history of atrial fibrillation (p = 0.03. 92% of the patients with atrial fibrillation suffered from DGE, compared to 46% of patients without atrial fibrillation (p = 0.0007. This association held true when controlling for age. CONCLUSION: Patients with postoperative atrial fibrillation are more likely to experience delayed gastric emptying. Interventions to manage delayed gastric function might be prudent in patients at high risk for postoperative atrial fibrillation.

  5. Projective synchronization of time-varying delayed neural network with adaptive scaling factors

    Ghosh, Dibakar; Banerjee, Santo

    2013-01-01

    Highlights: • Projective synchronization in coupled delayed neural chaotic systems with modulated delay time is introduced. • An adaptive rule for the scaling factors is introduced. • This scheme is highly applicable in secure communication. -- Abstract: In this work, the projective synchronization between two continuous time delayed neural systems with time varying delay is investigated. A sufficient condition for synchronization for the coupled systems with modulated delay is presented analytically with the help of the Krasovskii–Lyapunov approach. The effect of adaptive scaling factors on synchronization are also studied in details. Numerical simulations verify the effectiveness of the analytic results

  6. New approach to design and performance assessment of delay lines for radioactive rare gases

    Wilhelmova, L.; Dvorak, Z.; Cejnar, F.

    1981-01-01

    The evaluation and analysis are discussed of the dynamic adsorption of rare gases in the delay lines of nuclear power plants. The method of statistical momenta was used for deriving relations for the calculation of penetration curves of radioactive isotopes of rare gases through a delay line. Relations were also derived for the calculation of the capacity of delay line adsorption beds for both continuous and discontinuous operation. The procedures for the design and the derivation of the function of delay lines take into account the actual conditions of delay line operation in nuclear power plants. (author)

  7. General distributions in process algebra

    Katoen, Joost P.; d' Argenio, P.R.; Brinksma, Hendrik; Hermanns, H.; Katoen, Joost P.

    2001-01-01

    This paper is an informal tutorial on stochastic process algebras, i.e., process calculi where action occurrences may be subject to a delay that is governed by a (mostly continuous) random variable. Whereas most stochastic process algebras consider delays determined by negative exponential

  8. Cooperative relay-based multicasting for energy and delay minimization

    Atat, Rachad

    2012-08-01

    Relay-based multicasting for the purpose of cooperative content distribution is studied. Optimized relay selection is performed with the objective of minimizing the energy consumption or the content distribution delay within a cluster of cooperating mobiles. Two schemes are investigated. The first consists of the BS sending the data only to the relay, and the second scheme considers the scenario of threshold-based multicasting by the BS, where a relay is selected to transmit the data to the mobiles that were not able to receive the multicast data. Both schemes show significant superiority compared to the non-cooperative scenarios, in terms of energy consumption and delay reduction. © 2012 IEEE.

  9. PROMPT Ia SUPERNOVAE ARE SIGNIFICANTLY DELAYED

    Raskin, Cody; Scannapieco, Evan; Rhoads, James; Della Valle, Massimo

    2009-01-01

    The time delay between the formation of a population of stars and the onset of type Ia supernovae (SNe Ia) sets important limits on the masses and nature of SN Ia progenitors. Here, we use a new observational technique to measure this time delay by comparing the spatial distributions of SNe Ia to their local environments. Previous work attempted such analyses encompassing the entire host of each SN Ia, yielding inconclusive results. Our approach confines the analysis only to the relevant portions of the hosts, allowing us to show that even so-called prompt SNe Ia that trace star formation on cosmic timescales exhibit a significant delay time of 200-500 million years. This implies that either the majority of Ia companion stars have main-sequence masses less than 3 M sun , or that most SNe Ia arise from double white dwarf binaries. Our results are also consistent with a SNe Ia rate that traces the white dwarf formation rate, scaled by a fixed efficiency factor.

  10. All-optical delay technique for supporting multiple antennas in a hybrid optical - wireless transmission system

    Prince, Kamau; Chiuchiarelli, A; Presi, M

    2008-01-01

    We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency.......We introduce a novel continuously-variable optical delay technique to support beam-forming wireless communications systems using antenna arrays. We demonstrate delay with 64-QAM modulated signals at a rate of 15 Msymbol/sec with 2.5 GHz carrier frequency....

  11. Effects of Delayed Metamorphosis on Larval Survival, Metamorphosis, and Juvenile Performance of Four Closely Related Species of Tropical Sea Urchins (Genus Echinometra

    M. Aminur Rahman

    2014-01-01

    Full Text Available We report here, the effects of extended competency on larval survival, metamorphosis, and postlarval juvenile growth of four closely related species of tropical sea urchins, Echinometra sp. A (Ea, E. mathaei (Em, Echinometra sp. C (Ec, and E. oblonga (Eo. Planktotrophic larvae of all four species fed on cultured phytoplankton (Chaetoceros gracilis attained metamorphic competence within 22–24 days after fertilization. Competent larvae were forced to delay metamorphosis for up to 5 months by preventing them from settling in culture bottles with continuous stirring on a set of 10 rpm rotating rollers and larval survival per monthly intervals was recorded. Larval survival was highest at 24 days, when competence was attained (0 delayed period, and there were no significant differences among the four species. Larvae that had experienced a prolonged delay had reduced survival rate, metamorphosis success, and juvenile survival, but among older larvae, Em had the highest success followed by Ea, Eo, and Ec. Juveniles from larvae of all four species that metamorphosed soon after becoming competent tended to have higher growth rates (test diameter and length of spines than juveniles from larvae that metamorphosed after a prolonged period of competence with progressively slower growth the longer the prolonged period. Despite the adverse effects of delaying metamorphosis on growth parameters, competent larvae of all four species were able to survive up to 5 months and after metamorphosis grew into 1-month-old juveniles in lab condition. Overall, delayed larvae of Em showed significantly higher larval survival, metamorphosis, and juvenile survival than Ea and Eo, while Ec showed the lowest values in these performances. Em has the most widespread distribution of these species ranging from Africa to Hawaii, while Ec probably has the most restricted distribution. Consequently, differences in distribution may be related to differences in the ability to delay

  12. Effects of delayed metamorphosis on larval survival, metamorphosis, and juvenile performance of four closely related species of tropical sea urchins (genus Echinometra).

    Rahman, M Aminur; Yusoff, Fatimah Md; Arshad, A; Uehara, Tsuyoshi

    2014-01-01

    We report here, the effects of extended competency on larval survival, metamorphosis, and postlarval juvenile growth of four closely related species of tropical sea urchins, Echinometra sp. A (Ea), E. mathaei (Em), Echinometra sp. C (Ec), and E. oblonga (Eo). Planktotrophic larvae of all four species fed on cultured phytoplankton (Chaetoceros gracilis) attained metamorphic competence within 22-24 days after fertilization. Competent larvae were forced to delay metamorphosis for up to 5 months by preventing them from settling in culture bottles with continuous stirring on a set of 10 rpm rotating rollers and larval survival per monthly intervals was recorded. Larval survival was highest at 24 days, when competence was attained (0 delayed period), and there were no significant differences among the four species. Larvae that had experienced a prolonged delay had reduced survival rate, metamorphosis success, and juvenile survival, but among older larvae, Em had the highest success followed by Ea, Eo, and Ec. Juveniles from larvae of all four species that metamorphosed soon after becoming competent tended to have higher growth rates (test diameter and length of spines) than juveniles from larvae that metamorphosed after a prolonged period of competence with progressively slower growth the longer the prolonged period. Despite the adverse effects of delaying metamorphosis on growth parameters, competent larvae of all four species were able to survive up to 5 months and after metamorphosis grew into 1-month-old juveniles in lab condition. Overall, delayed larvae of Em showed significantly higher larval survival, metamorphosis, and juvenile survival than Ea and Eo, while Ec showed the lowest values in these performances. Em has the most widespread distribution of these species ranging from Africa to Hawaii, while Ec probably has the most restricted distribution. Consequently, differences in distribution may be related to differences in the ability to delay metamorphosis.

  13. Opportunities for Process Monitoring Techniques at Delayed Access Facilities

    Curtis, Michael M.; Gitau, Ernest TN; Johnson, Shirley J.; Schanfein, Mark; Toomey, Christopher

    2013-09-20

    Except for specific cases where the International Atomic Energy Agency (IAEA) maintains a continuous presence at a facility (such as the Japanese Rokkasho Reprocessing Plant), there is always a period of time or delay between the moment a State is notified or aware of an upcoming inspection, and the time the inspector actually enters the material balance area or facility. Termed by the authors as “delayed access,” this period of time between inspection notice and inspector entrance to a facility poses a concern. Delayed access also has the potential to reduce the effectiveness of measures applied as part of the Safeguards Approach for a facility (such as short-notice inspections). This report investigates the feasibility of using process monitoring to address safeguards challenges posed by delayed access at a subset of facility types.

  14. Sliding Intermittent Control for BAM Neural Networks with Delays

    Jianqiang Hu

    2013-01-01

    Full Text Available This paper addresses the exponential stability problem for a class of delayed bidirectional associative memory (BAM neural networks with delays. A sliding intermittent controller which takes the advantages of the periodically intermittent control idea and the impulsive control scheme is proposed and employed to the delayed BAM system. With the adjustable parameter taking different particular values, such a sliding intermittent control method can comprise several kinds of control schemes as special cases, such as the continuous feedback control, the impulsive control, the periodically intermittent control, and the semi-impulsive control. By using analysis techniques and the Lyapunov function methods, some sufficient criteria are derived for the closed-loop delayed BAM neural networks to be globally exponentially stable. Finally, two illustrative examples are given to show the effectiveness of the proposed control scheme and the obtained theoretical results.

  15. Climate models with delay differential equations

    Keane, Andrew; Krauskopf, Bernd; Postlethwaite, Claire M.

    2017-11-01

    A fundamental challenge in mathematical modelling is to find a model that embodies the essential underlying physics of a system, while at the same time being simple enough to allow for mathematical analysis. Delay differential equations (DDEs) can often assist in this goal because, in some cases, only the delayed effects of complex processes need to be described and not the processes themselves. This is true for some climate systems, whose dynamics are driven in part by delayed feedback loops associated with transport times of mass or energy from one location of the globe to another. The infinite-dimensional nature of DDEs allows them to be sufficiently complex to reproduce realistic dynamics accurately with a small number of variables and parameters. In this paper, we review how DDEs have been used to model climate systems at a conceptual level. Most studies of DDE climate models have focused on gaining insights into either the global energy balance or the fundamental workings of the El Niño Southern Oscillation (ENSO) system. For example, studies of DDEs have led to proposed mechanisms for the interannual oscillations in sea-surface temperature that is characteristic of ENSO, the irregular behaviour that makes ENSO difficult to forecast and the tendency of El Niño events to occur near Christmas. We also discuss the tools used to analyse such DDE models. In particular, the recent development of continuation software for DDEs makes it possible to explore large regions of parameter space in an efficient manner in order to provide a "global picture" of the possible dynamics. We also point out some directions for future research, including the incorporation of non-constant delays, which we believe could improve the descriptive power of DDE climate models.

  16. Climate models with delay differential equations.

    Keane, Andrew; Krauskopf, Bernd; Postlethwaite, Claire M

    2017-11-01

    A fundamental challenge in mathematical modelling is to find a model that embodies the essential underlying physics of a system, while at the same time being simple enough to allow for mathematical analysis. Delay differential equations (DDEs) can often assist in this goal because, in some cases, only the delayed effects of complex processes need to be described and not the processes themselves. This is true for some climate systems, whose dynamics are driven in part by delayed feedback loops associated with transport times of mass or energy from one location of the globe to another. The infinite-dimensional nature of DDEs allows them to be sufficiently complex to reproduce realistic dynamics accurately with a small number of variables and parameters. In this paper, we review how DDEs have been used to model climate systems at a conceptual level. Most studies of DDE climate models have focused on gaining insights into either the global energy balance or the fundamental workings of the El Niño Southern Oscillation (ENSO) system. For example, studies of DDEs have led to proposed mechanisms for the interannual oscillations in sea-surface temperature that is characteristic of ENSO, the irregular behaviour that makes ENSO difficult to forecast and the tendency of El Niño events to occur near Christmas. We also discuss the tools used to analyse such DDE models. In particular, the recent development of continuation software for DDEs makes it possible to explore large regions of parameter space in an efficient manner in order to provide a "global picture" of the possible dynamics. We also point out some directions for future research, including the incorporation of non-constant delays, which we believe could improve the descriptive power of DDE climate models.

  17. Earth system commitments due to delayed mitigation

    Pfister, Patrik L; Stocker, Thomas F

    2016-01-01

    As long as global CO 2 emissions continue to increase annually, long-term committed Earth system changes grow much faster than current observations. A novel metric linking this future growth to policy decisions today is the mitigation delay sensitivity (MDS), but MDS estimates for Earth system variables other than peak temperature (ΔT max ) are missing. Using an Earth System Model of Intermediate Complexity, we show that the current emission increase rate causes a ΔT max increase roughly 3–7.5 times as fast as observed warming, and a millenial steric sea level rise (SSLR) 7–25 times as fast as observed SSLR, depending on the achievable rate of emission reductions after the peak of emissions. These ranges are only slightly affected by the uncertainty range in equilibrium climate sensitivity, which is included in the above values. The extent of ocean acidification at the end of the century is also strongly dependent on the starting time and rate of emission reductions. The preservable surface ocean area with sufficient aragonite supersaturation for coral reef growth is diminished globally at an MDS of roughly 25%–80% per decade. A near-complete loss of this area becomes unavoidable if mitigation is delayed for a few years to decades. Also with respect to aragonite, 12%–18% of the Southern Ocean surface become undersaturated per decade, if emission reductions are delayed beyond 2015–2040. We conclude that the consequences of delaying global emission reductions are much better captured if the MDS of relevant Earth system variables is communicated in addition to current trends and total projected future changes. (letter)

  18. Linear rotary optical delay lines

    Guerboukha, Hichem; Qu, Hang; Skorobogatiy, Maksim

    2016-03-01

    We present a semi-analytical solution for the design of a high-speed rotary optical delay line that use a combination of two rotating curvilinear reflectors. We demonstrate that it is possible to design an infinite variety of the optical delay lines featuring linear dependence of the optical delay on the rotation angle. This is achieved via shape optimization of the rotating reflector surfaces. Moreover, a convenient spatial separation of the incoming and outgoing beams is possible. For the sake of example, we present blades that fit into a circle of 10cm diameter. Finally, a prototype of a rotary delay line is fabricated using CNC machining, and its optical properties are characterized.

  19. Transmission Delay Modeling of Packet Communication over Digital Subscriber Line

    Jiri Vodrazka

    2013-01-01

    Full Text Available Certain multimedia and voice services, such as VoIP, IPTV, etc., are significantly delay sensitive and their performance is influenced by the overall transmission delay and its variance. One of the most common solutions used in access networks are xDSL lines, especially ADSL2+ or VDSL2. Although these subscriber lines also use packet communication, there are several differences and mechanisms, which influence their resulting delay. Their delay characteristics are also dependent on the individual settings of each xDSL provider, therefore we decided to investigate this area for typical commercially available lines in Czech Republic. Based on the measured values and experiments with real ADSL2+ lines we also developed a potential modeling method, which is presented in this article as well. The parameters for packet jitter based on the generalized Pareto distribution were modeled.

  20. Systematics in delayed neutron yields

    Ohsawa, Takaaki [Kinki Univ., Higashi-Osaka, Osaka (Japan). Atomic Energy Research Inst.

    1998-03-01

    An attempt was made to reproduce the systematic trend observed in the delayed neutron yields for actinides on the basis of the five-Gaussian representation of the fission yield together with available data sets for delayed neutron emission probability. It was found that systematic decrease in DNY for heavier actinides is mainly due to decrease of fission yields of precursors in the lighter side of the light fragment region. (author)

  1. Global exponential stability of octonion-valued neural networks with leakage delay and mixed delays.

    Popa, Călin-Adrian

    2018-06-08

    This paper discusses octonion-valued neural networks (OVNNs) with leakage delay, time-varying delays, and distributed delays, for which the states, weights, and activation functions belong to the normed division algebra of octonions. The octonion algebra is a nonassociative and noncommutative generalization of the complex and quaternion algebras, but does not belong to the category of Clifford algebras, which are associative. In order to avoid the nonassociativity of the octonion algebra and also the noncommutativity of the quaternion algebra, the Cayley-Dickson construction is used to decompose the OVNNs into 4 complex-valued systems. By using appropriate Lyapunov-Krasovskii functionals, with double and triple integral terms, the free weighting matrix method, and simple and double integral Jensen inequalities, delay-dependent criteria are established for the exponential stability of the considered OVNNs. The criteria are given in terms of complex-valued linear matrix inequalities, for two types of Lipschitz conditions which are assumed to be satisfied by the octonion-valued activation functions. Finally, two numerical examples illustrate the feasibility, effectiveness, and correctness of the theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

  2. Editorial Commentary: "Defer No Time, Delays Have Dangerous Ends" (Henry VI, Shakespeare): Delayed Anterior Cruciate Ligament Reconstruction Has Consequences.

    Siegel, Mark G

    2018-06-01

    There continues to be controversy over the timing of anterior cruciate ligament (ACL) surgery. Early or delayed intervention after ACL injury is a topic that has not been settled. The issue is whether ACL tears should have surgery performed in an expedient manner. Or is delay an option with no repercussions to the health of the knee? My associates in nonsurgical specialties wave the New England Journal of Medicine to support their view that surgery is not needed. I routinely espouse the literature confirming that delay of surgery may cause future damage. It is now established that a failure to intervene in a timely manner does cause additional damage. I stand vindicated and can affirm to my colleagues that I have found the answer. There is no longer any doubt or equivocation. Delay in reconstructing an unstable knee does cause damage. Copyright © 2018 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  3. Maturational delay in ADHD: Evidence from CPT

    Itai eBerger

    2013-10-01

    Full Text Available While data from behavioural, neuropsychological, and brain studies suggested that Attention-Deficit/Hyperactivity Disorder (ADHD is related to a developmental lag that reduces with age, other studies have proposed that ADHD represents a deviant brain function. The present study used a cross-sectional approach to examine whether ADHD children show a developmental delay in cognitive performance measured by continuous performance test (CPT. We thus compared six age groups of ADHD children (N=559 and their unaffected peers (N=365, aged 6-11, in four parameters of MOXO-CPT performance: Attention, Timing, Hyperactivity and Impulsivity. Results have shown that despite improvement in CPT performance with age, ADHD children continued to demonstrate impaired performance as compared to controls. In most parameters, CPT performance of ADHD children matched that of 1-3 years younger normal controls, with a delay most prominent in older children. However, in the Hyperactivity parameter, ADHD children’s performance resembled that of much younger healthy children, with almost no evidence for a developmental catch up. This study suggests that while some cognitive functions develop slower but normally, other functions (e.g., inhibitory control show a different sequel.

  4. Exploring delay causes of road construction projects in

    Remon F. Aziz

    2016-06-01

    Full Text Available Construction delays are a common phenomenon in civil engineering projects in Egypt including road construction projects. Therefore, it is essential to study and analyze causes of road construction delays. This paper studied a list of construction delay causes gathered from literature having different types of construction, different countries, different periods and different numbers of delay causes and delay groups. A questionnaire and personal interviews have formed the basis of this paper listing 293 delay causes. The questionnaire survey was distributed to 500 construction participants and 389 were received who represent consultants, contractors and site/design engineers excluding the owner representing the government in road projects as one party only. Relative Importance Index (RII is calculated and according to the highest values the top twenty and the least twenty delay causes of construction projects in Egypt are determined. A case study is analyzed and compared to the most important delay causes in the paper. The test results reveal good correlation of causes and groups between contractors and site/design engineers and between consultants and site design engineers and a somewhat low correlation between contractors and consultants. So there are no root causes that can be taking for granted to be most or least effective delay causes. Proposed model for predicting actual road construction project duration was developed; a real case study tested the accuracy of proposed model. According to the analysis of case study, the most contributing causes and groups to delays were discussed, and some future recommendations were proposed in order to control and minimize delays in road construction projects. These findings can be helpful for project managers to mitigate the road construction delays in Egypt. In order to effectively overcome the road construction delays in developing countries, suggestions are made for fundamental and large

  5. Delayed Self-Recognition in Children with Autism Spectrum Disorder

    Lind, Sophie E.; Bowler, Dermot M.

    2009-01-01

    This study aimed to investigate temporally extended self-awareness (awareness of one's place in and continued existence through time) in autism spectrum disorder (ASD), using the delayed self-recognition (DSR) paradigm (Povinelli et al., Child Development 67:1540-1554, 1996). Relative to age and verbal ability matched comparison children, children…

  6. Application of data clustering to railway delay pattern recognition

    Cerreto, Fabrizio; Nielsen, Bo Friis; Nielsen, Otto Anker

    2018-01-01

    K-means clustering is employed to identify recurrent delay patterns on a high traffic railway line north of Copenhagen, Denmark. The clusters identify behavioral patterns in the very large (“big data”) data sets generated automatically and continuously by the railway signal system. The results re...

  7. Fundamentals of Delayed Coking Joint Industry Project

    Michael Volk; Keith Wisecarver

    2003-09-26

    Delayed coking evolved steadily over the early to mid 1900s to enable refiners to convert high boiling, residual petroleum fractions to light products such as gasoline. Pound for pound, coking is the most energy intensive of any operation in a modern refinery. Large amounts of energy are required to heat the thick, poor-quality petroleum residuum to the 900 to 950 degrees F required to crack the heavy hydrocarbon molecules into lighter, more valuable products. One common misconception of delayed coking is that the product coke is a disadvantage. Although coke is a low valued (near zero economic value) byproduct, compared to transportation fuels, there is a significant worldwide trade and demand for coke as it is an economical fuel. Coke production has increased steadily over the last ten years, with further increases forecast for the foreseeable future. Current domestic production is near 111,000 tons per day. A major driving force behind this increase is the steady decline in crude quality available to refiners. Crude slates are expected to grow heavier with higher sulfur contents while environmental restrictions are expected to significantly reduce the demand for high-sulfur residual fuel oil. Light sweet crudes will continue to be available and in even greater demand than they are today. Refiners will be faced with the choice of purchasing light sweet crudes at a premium price, or adding bottom of the barrel upgrading capability, through additional new investments, to reduce the production of high-sulfur residual fuel oil and increase the production of low-sulfur distillate fuels. A second disadvantage is that liquid products from cokers frequently are unstable, i.e., they rapidly form gum and sediments. Because of intermediate investment and operating costs, delayed coking has increased in popularity among refiners worldwide. Based on the 2000 Worldwide Refining Survey published in the Oil and Gas, the delayed coking capacity for 101 refineries around the world

  8. Parameter Estimation of a Delay Time Model of Wearing Parts Based on Objective Data

    Y. Tang

    2015-01-01

    Full Text Available The wearing parts of a system have a very high failure frequency, making it necessary to carry out continual functional inspections and maintenance to protect the system from unscheduled downtime. This allows for the collection of a large amount of maintenance data. Taking the unique characteristics of the wearing parts into consideration, we establish their respective delay time models in ideal inspection cases and nonideal inspection cases. The model parameters are estimated entirely using the collected maintenance data. Then, a likelihood function of all renewal events is derived based on their occurring probability functions, and the model parameters are calculated with the maximum likelihood function method, which is solved by the CRM. Finally, using two wearing parts from the oil and gas drilling industry as examples—the filter element and the blowout preventer rubber core—the parameters of the distribution function of the initial failure time and the delay time for each example are estimated, and their distribution functions are obtained. Such parameter estimation based on objective data will contribute to the optimization of the reasonable function inspection interval and will also provide some theoretical models to support the integrity management of equipment or systems.

  9. The energy spectrum of delayed neutrons from thermal neutron induced fission of 235U and its analytical approximation

    Doroshenko, A.Yu.; Tarasko, M.Z.; Piksaikin, V.M.

    2002-01-01

    The energy spectrum of the delayed neutrons is the poorest known of all input data required in the calculation of the effective delayed neutron fractions. In addition to delayed neutron spectra based on the aggregate spectrum measurements there are two different approaches for deriving the delayed neutron energy spectra. Both of them are based on the data related to the delayed neutron spectra from individual precursors of delayed neutrons. In present work these two different data sets were compared with the help of an approximation by gamma-function. The choice of this approximation function instead of the Maxwellian or evaporation type of distribution is substantiated. (author)

  10. Synchronization of time-delayed systems with chaotic modulation and cryptography

    Banerjee, Santo

    2009-01-01

    This paper presents a method of synchronization between two time-delayed systems where the delay times are modulated by a common chaotic signal of the driving system. The technique is well applied to two identical autonomous continuous-time-delayed systems with numerical simulations. Finally, a new method of encryption is generated for digital messages. This method is illustrated with two different encryption processes for text as well as picture messages.

  11. Delays at signalised intersections with exhaustive traffic control

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2010-01-01

    In this paper we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under Heavy Traffic (HT) conditions,

  12. Power and delay optimisation in multi-hop wireless networks

    Xia, Li; Shihada, Basem

    2014-01-01

    in order to minimise the power consumption and the queueing delay of the whole network. With the assumptions of interference-free links and independently and identically distributed (i.i.d.) channel states, we formulate this problem using a semi

  13. A Monte Carlo approach to combating delayed completion of ...

    The objective of this paper is to unveil the relevance of Monte Carlo critical path analysis in resolving problem of delays in scheduled completion of development projects. Commencing with deterministic network scheduling, Monte Carlo critical path analysis was advanced by assigning probability distributions to task times.

  14. Delays at signalized intersections with exhaustive traffic control

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2012-01-01

    In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

  15. Delays at signalised intersections with exhaustive traffic control

    Boon, M.A.A.; Adan, I.J.B.F.; Winands, E.M.M.; Down, D.G.

    2012-01-01

    In this paper, we study a traffic intersection with vehicle-actuated traffic signal control. Traffic lights stay green until all lanes within a group are emptied. Assuming general renewal arrival processes, we derive exact limiting distributions of the delays under heavy traffic (HT) conditions.

  16. Diffusion model of delayed hydride cracking in zirconium alloys

    Shmakov, AA; Kalin, BA; Matvienko, YG; Singh, RN; De, PK

    2004-01-01

    We develop a method for the evaluation of the rate of delayed hydride cracking in zirconium alloys. The model is based on the stationary solution of the phenomenological diffusion equation and the detailed analysis of the distribution of hydrostatic stresses in the plane of a sharp tensile crack.

  17. Delayed fission of the 238U muonic atom

    Ganzorig, Dz.; Krogulski, T.; Kuznetsov, V.D.; Polikanov, S.M.; Sabirov, B.M.

    1975-01-01

    The time distributions of fission and muon free decay events with respect to the moment of the muon-stop event have been measured for double and triple coincidences between these three events. The triple-coincidence time distributions give an indication of the o-curence of two new effects: the delayed fission of muonic 238 U atom and conversion of muons from the fission fragments

  18. Continuous EEG Monitoring in Aneurysmal Subarachnoid Hemorrhage

    Kondziella, Daniel; Friberg, Christian Kærsmose; Wellwood, Ian

    2015-01-01

    BACKGROUND: Continuous EEG (cEEG) may allow monitoring of patients with aneurysmal subarachnoid hemorrhage (SAH) for delayed cerebral ischemia (DCI) and seizures, including non-convulsive seizures (NCSz), and non-convulsive status epilepticus (NCSE). We aimed to evaluate: (a) the diagnostic...

  19. Relation between delay and survival in 596 patients with breast cancer.

    Machiavelli, M; Leone, B; Romero, A; Perez, J; Vallejo, C; Bianco, A; Rodriguez, R; Estevez, R; Chacon, R; Dansky, C

    1989-01-01

    To evaluate the influence of delay between first symptom and first treatment upon survival the medical records of 596 patients with breast cancer were reviewed. The following intervals were considered: less than 3 months; 3-6 months and greater than 6 months. Patients in the less than 3 months delay group had a better distribution by clinical stages and a 10-year survival rate higher than those in the longer delay groups (p = 0.034). However, within each stage no statistically significant difference in survival according to delay was observed. A Cox multivariate analysis revealed that performance status and stage of disease were independent predictors of survival, but not delay. Assuming the best prognosis for patients with clinical stages I and II and less than 3 months delay, the group with longer delay times had 15 deaths over what would have been predicted. This adverse effect was observed almost exclusively among patients over age 50 (14/15).

  20. Probability distribution relationships

    Yousry Abdelkader

    2013-05-01

    Full Text Available In this paper, we are interesting to show the most famous distributions and their relations to the other distributions in collected diagrams. Four diagrams are sketched as networks. The first one is concerned to the continuous distributions and their relations. The second one presents the discrete distributions. The third diagram is depicted the famous limiting distributions. Finally, the Balakrishnan skew-normal density and its relationship with the other distributions are shown in the fourth diagram.