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Sample records for optimized intermittent random

  1. Optimal chemotaxis in animal cell intermittent migration

    CERN Document Server

    Romanczuk, Pawel

    2015-01-01

    Animal cells can sense chemical gradients without moving, and are faced with the challenge of migrating towards a target despite noisy information on the target position. Here we discuss optimal search strategies for a chaser that moves by switching between two phases of motion ("run" and "tumble"), reorienting itself towards the target during tumble phases, and performing a persistent random walk during run phases. We show that the chaser average run time can be adjusted to minimize the target catching time or the spatial dispersion of the chasers. We obtain analytical results for the catching time and for the spatial dispersion in the limits of small and large ratios of run time to tumble time, and scaling laws for the optimal run times. Our findings have implications for optimal chemotactic strategies in animal cell migration.

  2. Nonlinear random optical waves: Integrable turbulence, rogue waves and intermittency

    Science.gov (United States)

    Randoux, Stéphane; Walczak, Pierre; Onorato, Miguel; Suret, Pierre

    2016-10-01

    We examine the general question of statistical changes experienced by ensembles of nonlinear random waves propagating in systems ruled by integrable equations. In our study that enters within the framework of integrable turbulence, we specifically focus on optical fiber systems accurately described by the integrable one-dimensional nonlinear Schrödinger equation. We consider random complex fields having a Gaussian statistics and an infinite extension at initial stage. We use numerical simulations with periodic boundary conditions and optical fiber experiments to investigate spectral and statistical changes experienced by nonlinear waves in focusing and in defocusing propagation regimes. As a result of nonlinear propagation, the power spectrum of the random wave broadens and takes exponential wings both in focusing and in defocusing regimes. Heavy-tailed deviations from Gaussian statistics are observed in focusing regime while low-tailed deviations from Gaussian statistics are observed in defocusing regime. After some transient evolution, the wave system is found to exhibit a statistically stationary state in which neither the probability density function of the wave field nor the spectrum changes with the evolution variable. Separating fluctuations of small scale from fluctuations of large scale both in focusing and defocusing regimes, we reveal the phenomenon of intermittency; i.e., small scales are characterized by large heavy-tailed deviations from Gaussian statistics, while the large ones are almost Gaussian.

  3. Optimizing intermittent water supply in urban pipe distribution networks

    CERN Document Server

    Lieb, Anna M; Wilkening, Jon

    2015-01-01

    In many urban areas of the developing world, piped water is supplied only intermittently, as valves direct water to different parts of the water distribution system at different times. The flow is transient, and may transition between free-surface and pressurized, resulting in complex dynamical features with important consequences for water suppliers and users. Here, we develop a computational model of transition, transient pipe flow in a network, accounting for a wide variety of realistic boundary conditions. We validate the model against several published data sets, and demonstrate its use on a real pipe network. The model is extended to consider several optimization problems motivated by realistic scenarios. We demonstrate how to infer water flow in a small pipe network from a single pressure sensor, and show how to control water inflow to minimize damaging pressure gradients.

  4. Quasi-steady-state analysis of two-dimensional random intermittent search processes

    KAUST Repository

    Bressloff, Paul C.

    2011-06-01

    We use perturbation methods to analyze a two-dimensional random intermittent search process, in which a searcher alternates between a diffusive search phase and a ballistic movement phase whose velocity direction is random. A hidden target is introduced within a rectangular domain with reflecting boundaries. If the searcher moves within range of the target and is in the search phase, it has a chance of detecting the target. A quasi-steady-state analysis is applied to the corresponding Chapman-Kolmogorov equation. This generates a reduced Fokker-Planck description of the search process involving a nonzero drift term and an anisotropic diffusion tensor. In the case of a uniform direction distribution, for which there is zero drift, and isotropic diffusion, we use the method of matched asymptotics to compute the mean first passage time (MFPT) to the target, under the assumption that the detection range of the target is much smaller than the size of the domain. We show that an optimal search strategy exists, consistent with previous studies of intermittent search in a radially symmetric domain that were based on a decoupling or moment closure approximation. We also show how the decoupling approximation can break down in the case of biased search processes. Finally, we analyze the MFPT in the case of anisotropic diffusion and find that anisotropy can be useful when the searcher starts from a fixed location. © 2011 American Physical Society.

  5. Optimal Intermittent Dose Schedules for Chemotherapy Using Genetic Algorithm

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    Nadia ALAM

    2013-08-01

    Full Text Available In this paper, a design method for optimal cancer chemotherapy schedules via genetic algorithm (GA is presented. The design targets the key objective of chemotherapy to minimize the size of cancer tumor after a predefined time with keeping toxic side effects in limit. This is a difficult target to achieve using conventional clinical methods due to poor therapeutic indices of existing anti-cancer drugs. Moreover, there are clinical limitations in treatment administration to maintain continuous treatment. Besides, carefully decided rest periods are recommended to for patient’s comfort. Three intermittent drug scheduling schemes are presented in this paper where GA is used to optimize the dose quantities and timings by satisfying several treatment constraints. All three schemes are found to be effective in total elimination of cancer tumor after an agreed treatment length. The number of cancer cells is found zero at the end of the treatment for all three cases with tolerable toxicity. Finally, two of the schemes, “Fixed interval variable dose (FIVD and “Periodic dose” that are periodic in characteristic have been emphasized due to their additional simplicity in administration along with friendliness to patients. responses to the designed treatment schedules. Therefore the proposed design method is capable of planning effective, simple, patient friendly and acceptable chemotherapy schedules.

  6. Guided randomness in optimization

    CERN Document Server

    Clerc, Maurice

    2015-01-01

    The performance of an algorithm used depends on the GNA. This book focuses on the comparison of optimizers, it defines a stress-outcome approach which can be derived all the classic criteria (median, average, etc.) and other more sophisticated.   Source-codes used for the examples are also presented, this allows a reflection on the ""superfluous chance,"" succinctly explaining why and how the stochastic aspect of optimization could be avoided in some cases.

  7. Randomness-optimal Steganography

    CERN Document Server

    Kiayias, Aggelos; Shashidhar, Narasimha

    2009-01-01

    Steganographic protocols enables one to "embed" covert messages into inconspicous data over a public communication channel in such a way that no one, aside from the sender and the intended receiver can even detect the presence of the secret message. In this paper, we provide a new provably-secure, private-key steganographic encryption protocol. We prove the security of our protocol in the complexity-theoretic framework where security is quantified as the advantage (compared to a random guess) that the adversary has in distinguishing between innocent covertext and stegotext that embeds a message of his choice. The fundamental building block of our steganographic encryption protocol is a "one-time stegosystem" that allows two parties to transmit messages of length at most that of the shared key with information-theoretic security guarantees. The employment of a pseudorandom generator (PRG) permits secure transmission of longer messages in the same way that such a generator allows the use of one-time pad encrypt...

  8. Random intermittent search and the tug-of-war model of motor-driven transport

    KAUST Repository

    Newby, Jay

    2010-04-16

    We formulate the \\'tug-of-war\\' model of microtubule cargo transport by multiple molecular motors as an intermittent random search for a hidden target. A motor complex consisting of multiple molecular motors with opposing directional preference is modeled using a discrete Markov process. The motors randomly pull each other off of the microtubule so that the state of the motor complex is determined by the number of bound motors. The tug-of-war model prescribes the state transition rates and corresponding cargo velocities in terms of experimentally measured physical parameters. We add space to the resulting Chapman-Kolmogorov (CK) equation so that we can consider delivery of the cargo to a hidden target at an unknown location along the microtubule track. The target represents some subcellular compartment such as a synapse in a neuron\\'s dendrites, and target delivery is modeled as a simple absorption process. Using a quasi-steady-state (QSS) reduction technique we calculate analytical approximations of the mean first passage time (MFPT) to find the target. We show that there exists an optimal adenosine triphosphate (ATP) concentration that minimizes the MFPT for two different cases: (i) the motor complex is composed of equal numbers of kinesin motors bound to two different microtubules (symmetric tug-of-war model) and (ii) the motor complex is composed of different numbers of kinesin and dynein motors bound to a single microtubule (asymmetric tug-of-war model). © 2010 IOP Publishing Ltd.

  9. Optimal randomized scheduling by replacement

    Energy Technology Data Exchange (ETDEWEB)

    Saias, I.

    1996-05-01

    In the replacement scheduling problem, a system is composed of n processors drawn from a pool of p. The processors can become faulty while in operation and faulty processors never recover. A report is issued whenever a fault occurs. This report states only the existence of a fault but does not indicate its location. Based on this report, the scheduler can reconfigure the system and choose another set of n processors. The system operates satisfactorily as long as, upon report of a fault, the scheduler chooses n non-faulty processors. We provide a randomized protocol maximizing the expected number of faults the system can sustain before the occurrence of a crash. The optimality of the protocol is established by considering a closely related dual optimization problem. The game-theoretic technical difficulties that we solve in this paper are very general and encountered whenever proving the optimality of a randomized algorithm in parallel and distributed computation.

  10. Cognitive-Behavioral Therapy for Intermittent Explosive Disorder: A Pilot Randomized Clinical Trial

    Science.gov (United States)

    McCloskey, Michael S.; Noblett, Kurtis L.; Deffenbacher, Jerry L.; Gollan, Jackie K.; Coccaro, Emil F.

    2008-01-01

    No randomized clinical trials have evaluated the efficacy of psychotherapy for intermittent explosive disorder (IED). In the present study, the authors tested the efficacy of 12-week group and individual cognitive-behavioral therapies (adapted from J. L. Deffenbacher & M. McKay, 2000) by comparing them with a wait-list control in a randomized…

  11. Cognitive-Behavioral Therapy for Intermittent Explosive Disorder: A Pilot Randomized Clinical Trial

    Science.gov (United States)

    McCloskey, Michael S.; Noblett, Kurtis L.; Deffenbacher, Jerry L.; Gollan, Jackie K.; Coccaro, Emil F.

    2008-01-01

    No randomized clinical trials have evaluated the efficacy of psychotherapy for intermittent explosive disorder (IED). In the present study, the authors tested the efficacy of 12-week group and individual cognitive-behavioral therapies (adapted from J. L. Deffenbacher & M. McKay, 2000) by comparing them with a wait-list control in a randomized…

  12. Safety of a New Compact Male Intermittent Catheter: Randomized, Cross-Over, Single-Blind Study in Healthy Male Volunteers

    DEFF Research Database (Denmark)

    Bagi, Per; Hannibalsen, Jane; Permild, Rikke

    2011-01-01

    Introduction: A new compact male intermittent catheter was compared with a regular intermittent male catheter in terms of safety and acceptability. Methods: In this randomized, single-blind, cross-over study, healthy male volunteers were catheterized twice with a compact catheter and twice with a...

  13. Optimal control strategies for hydrogen production when coupling solid oxide electrolysers with intermittent renewable energies

    Science.gov (United States)

    Cai, Qiong; Adjiman, Claire S.; Brandon, Nigel P.

    2014-12-01

    The penetration of intermittent renewable energies requires the development of energy storage technologies. High temperature electrolysis using solid oxide electrolyser cells (SOECs) as a potential energy storage technology, provides the prospect of a cost-effective and energy efficient route to clean hydrogen production. The development of optimal control strategies when SOEC systems are coupled with intermittent renewable energies is discussed. Hydrogen production is examined in relation to energy consumption. Control strategies considered include maximizing hydrogen production, minimizing SOEC energy consumption and minimizing compressor energy consumption. Optimal control trajectories of the operating variables over a given period of time show feasible control for the chosen situations. Temperature control of the SOEC stack is ensured via constraints on the overall temperature difference across the cell and the local temperature gradient within the SOEC stack, to link materials properties with system performance; these constraints are successfully managed. The relative merits of the optimal control strategies are analyzed.

  14. Intermittently Connected Cloudlet System to Obtain an Optimal Offloading Policy

    Directory of Open Access Journals (Sweden)

    Nadim Akhtar

    2016-09-01

    Full Text Available The great potential has been shown over the performance enhancement for offloading the mobile devices within intensive parts of computation within mobile cloud application. The complete realization for the potential which being mismatch within the particular mobile devices on the resource computing demand and that provide an offer. The request over offloading is connecting the variable network where cloud services are always being in the required process within infrequent, variable connectivity of network and quick response time for relatively incurring the times for long setup and quanta for long time are may be indifferent for the connectivity of network. The requirement over the mobile application is needed more resources for executing the single device task within the fact of mobile devices enhanced capabilities. The problems have been addressed for several computation of offloading the remote cloud services and resources which is locating the computing resources in the cloudlets. The proposed concept is proposing an experimental approach for highlighting the tradeoff of offloading. The proposed architecture of the generic algorithm is performing an integration of mobile cloud computing for automatic offloading to improve the application response time when minimizing the consumption of energy for mobile device. Offloading task within a remote machine is not better than performing task particularly. The particular performance of the task is always better than remote machine. The proposed system is developing an algorithm of optimal offloading for mobile user which considering over the cloudlets availability and local load of user’s. The solution and formulation of the MDP (Markov Decision Process model is for obtaining a policy to the user mobile and minimizing the objective of offloading cost and computation cost.

  15. Optimization of continuous and intermittent microwave extraction of pectin from banana peels.

    Science.gov (United States)

    Swamy, Gabriela John; Muthukumarappan, Kasiviswanathan

    2017-04-01

    Continuous and intermittent microwave-assisted extractions were used to extract pectin from banana peels. Extraction parameters which were employed in the continuous process were microwave power (300-900W), time (100-300s), pH (1-3) and in the intermittent process were microwave power (300-900W), pulse ratio (0.5-1), pH (1-3). The independent factors were optimized with the Box-Behnken response surface design (BBD) (three factor three level) with the desirability function methodology. Results indicate that the independent factors have substantial effect on the pectin yield. Optimized solutions for highest pectin yield (2.18%) from banana peels were obtained with microwave power of 900W, time 100s and pH 3.00 in the continuous method while the intermittent process yielded the highest pectin content (2.58%) at microwave power of 900W, pulse ratio of 0.5 and pH of 3.00. The optimized conditions were validated and close agreement was observed with the validation experiment and predicted value.

  16. A non-inferiority, individually randomized trial of intermittent screening and treatment versus intermittent preventive treatment in the control of malaria in pregnancy

    DEFF Research Database (Denmark)

    Tagbor, Harry; Cairns, Matthew; Bojang, Kalifa

    2015-01-01

    BACKGROUND: The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women...... (ISTp) is an alternative approach. METHODS AND FINDINGS: An open, individually randomized, non-inferiority trial of IPTp-SP versus ISTp was conducted in 5,354 primi- or secundigravidae in four West African countries with a low prevalence of resistance to SP (The Gambia, Mali, Burkina Faso and Ghana......-AL performed as well as IPTp-SP. In the absence of an effective alternative medication to SP for IPTp, ISTp-AL is a potential alternative to IPTp in areas where SP resistance is high. It may also have a role in areas where malaria transmission is low and for the prevention of malaria in HIV positive women...

  17. Robustness of optimal intermittent search strategies in one, two, and three dimensions.

    Science.gov (United States)

    Loverdo, C; Bénichou, O; Moreau, M; Voituriez, R

    2009-09-01

    Search problems at various scales involve a searcher, be it a molecule before reaction or a foraging animal, which performs an intermittent motion. Here we analyze a generic model based on such type of intermittent motion, in which the searcher alternates phases of slow motion allowing detection and phases of fast motion without detection. We present full and systematic results for different modeling hypotheses of the detection mechanism in space in one, two, and three dimensions. Our study completes and extends the results of our recent letter [Loverdo, Nat. Phys. 4, 134 (2008)] and gives the necessary calculation details. In addition, another modeling of the detection case is presented. We show that the mean target detection time can be minimized as a function of the mean duration of each phase in one, two, and three dimensions. Importantly, this optimal strategy does not depend on the details of the modeling of the slow detection phase, which shows the robustness of our results. We believe that this systematic analysis can be used as a basis to study quantitatively various real search problems involving intermittent behaviors.

  18. Randomized double-blind placebo-controlled crossover study of caffeine in patients with intermittent claudication

    DEFF Research Database (Denmark)

    Momsen, A H; Jensen, M B; Norager, C B

    2010-01-01

    Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication.......Intermittent claudication is a disabling symptom of peripheral arterial disease for which few medical treatments are available. This study investigated the effect of caffeine on physical capacity in patients with intermittent claudication....

  19. A New Range Sidelobe Suppression Technique for Randomly Intermittent Spectra HF Radar Signal

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong-po; LIU Xing-zhao

    2005-01-01

    The randomly intermittent spectra (RIS) signal is employed to combat spectrum congestion in radar and other radio services to evade the external interferences in high-frequency (HF) and ultrahigh-frequency (UHF)bands. However, the spectra discontinuity of the signal gets rise to high range sidelobes when matching the refleeted echo, which is much more difficult for targets detection. So it is indispensable to investigate the technique for sidelobes suppression of the range profile when RIS signal is utilized, This paper introduced a new processing technique based on time domain filtering to lower the range sidelobes. A robust and effetive algorithm is adopted to solve the coefficients of the filter, and the restriction on the desired response of the filter is derived. The simulation results show that the peak range sidelobe can be reduced to -27 dB from -9.5 dB while the frequency band span (FBS) is 200 kHz.

  20. Reliable H∞ control of discrete-time systems against random intermittent faults

    Science.gov (United States)

    Tao, Yuan; Shen, Dong; Fang, Mengqi; Wang, Youqing

    2016-07-01

    A passive fault-tolerant control strategy is proposed for systems subject to a novel kind of intermittent fault, which is described by a Bernoulli distributed random variable. Three cases of fault location are considered, namely, sensor fault, actuator fault, and both sensor and actuator faults. The dynamic feedback controllers are designed not only to stabilise the fault-free system, but also to guarantee an acceptable performance of the faulty system. The robust H∞ performance index is used to evaluate the effectiveness of the proposed control scheme. In terms of linear matrix inequality, the sufficient conditions of the existence of controllers are given. An illustrative example indicates the effectiveness of the proposed fault-tolerant control method.

  1. Passive target tracking with intermittent measurement based on random finite set

    Institute of Scientific and Technical Information of China (English)

    罗小波; 范红旗; 宋志勇; 付强

    2014-01-01

    In the tracking problem for the maritime radiation source by a passive sensor, there are three main difficulties, i.e., the poor observability of the radiation source, the detection uncertainty (false and missed detections) and the uncertainty of the target appearing/disappearing in the field of view. These difficulties can make the establishment or maintenance of the radiation source target track invalid. By incorporating the elevation information of the passive sensor into the automatic bearings-only tracking (BOT) and consolidating these uncertainties under the framework of random finite set (RFS), a novel approach for tracking maritime radiation source target with intermittent measurement was proposed. Under the RFS framework, the target state was represented as a set that can take on either an empty set or a singleton; meanwhile, the measurement uncertainty was modeled as a Bernoulli random finite set. Moreover, the elevation information of the sensor platform was introduced to ensure observability of passive measurements and obtain the unique target localization. Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source and demonstrate the superiority of the proposed approach in comparison with the traditional integrated probabilistic data association (IPDA) method. The tracking performance under different conditions, particularly involving different existence probabilities and different appearance durations of the target, indicates that the method to solve our problem is robust and effective.

  2. Nonlinear system identification for prostate cancer and optimality of intermittent androgen suppression therapy.

    Science.gov (United States)

    Suzuki, Taiji; Aihara, Kazuyuki

    2013-09-01

    These days prostate cancer is one of the most common types of malignant neoplasm in men. Androgen ablation therapy (hormone therapy) has been shown to be effective for advanced prostate cancer. However, continuous hormone therapy often causes recurrence. This results from the progression of androgen-dependent cancer cells to androgen-independent cancer cells during the continuous hormone therapy. One possible method to prevent the progression to the androgen-independent state is intermittent androgen suppression (IAS) therapy, which ceases dosing intermittently. In this paper, we propose two methods to estimate the dynamics of prostate cancer, and investigate the IAS therapy from the viewpoint of optimality. The two methods that we propose for dynamics estimation are a variational Bayesian method for a piecewise affine (PWA) system and a Gaussian process regression method. We apply the proposed methods to real clinical data and compare their predictive performances. Then, using the estimated dynamics of prostate cancer, we observe how prostate cancer behaves for various dosing schedules. It can be seen that the conventional IAS therapy is a way of imposing high cost for dosing while keeping the prostate cancer in a safe state. We would like to dedicate this paper to the memory of Professor Luigi M. Ricciardi.

  3. Optimal paths as correlated random walks

    Science.gov (United States)

    Perlsman, E.; Havlin, S.

    2006-01-01

    A numerical study of optimal paths in the directed polymer model shows that the paths are similar to correlated random walks. It is shown that when a directed optimal path of length t is divided into 3 segments whose length is t/3, the correlation between the transversal movements along the first and last path segments is independent of the path length t. It is also shown that the transversal correlations along optimal paths decrease as the paths approach their endpoints. The numerical results obtained for optimal paths in 1+4 dimensions are qualitatively similar to those obtained for optimal paths in lower dimensions, and the data supplies a strong numerical indication that 1+4 is not the upper critical dimension of this model, and of the associated KPZ equation.

  4. Does prolonged β-lactam infusions improve clinical outcomes compared to intermittent infusions? A meta-analysis and systematic review of randomized, controlled trials

    Directory of Open Access Journals (Sweden)

    Van Arendonk Kyle J

    2011-06-01

    Full Text Available Abstract Background The emergence of multi-drug resistant Gram-negatives (MDRGNs coupled with an alarming scarcity of new antibiotics has forced the optimization of the therapeutic potential of available antibiotics. To exploit the time above the minimum inhibitory concentration mechanism of β-lactams, prolonging their infusion may improve outcomes. The primary objective of this meta-analysis was to determine if prolonged β-lactam infusion resulted in decreased mortality and improved clinical cure compared to intermittent β-lactam infusion. Methods Relevant studies were identified from searches of MEDLINE, EMBASE, and CENTRAL. Heterogeneity was assessed qualitatively, in addition to I2 and Chi-square statistics. Pooled relative risks (RR and 95% confidence intervals (CI were calculated using Mantel-Haenszel random-effects models. Results Fourteen randomized controlled trials (RCTs were included. Prolonged infusion β-lactams were not associated with decreased mortality (n= 982; RR 0.92; 95% CI:0.61-1.37 or clinical cure (n = 1380; RR 1.00 95% CI:0.94-1.06 compared to intermittent infusions. Subgroup analysis for β-lactam subclasses and equivalent total daily β-lactam doses yielded similar results. Most studies had notable methodological flaws. Conclusions No clinical advantage was observed for prolonged infusion β-lactams. The limited number of studies with MDRGNs precluded evaluation of prolonged infusion of β-lactams for this subgroup. A large, multicenter RCT with critically ill patients infected with MDRGNs is needed.

  5. Filling of a Poisson trap by a population of random intermittent searchers

    KAUST Repository

    Bressloff, Paul C.

    2012-03-01

    We extend the continuum theory of random intermittent search processes to the case of N independent searchers looking to deliver cargo to a single hidden target located somewhere on a semi-infinite track. Each searcher randomly switches between a stationary state and either a leftward or rightward constant velocity state. We assume that all of the particles start at one end of the track and realize sample trajectories independently generated from the same underlying stochastic process. The hidden target is treated as a partially absorbing trap in which a particle can only detect the target and deliver its cargo if it is stationary and within range of the target; the particle is removed from the system after delivering its cargo. As a further generalization of previous models, we assume that up to n successive particles can find the target and deliver its cargo. Assuming that the rate of target detection scales as 1/N, we show that there exists a well-defined mean-field limit N→ in which the stochastic model reduces to a deterministic system of linear reaction-hyperbolic equations for the concentrations of particles in each of the internal states. These equations decouple from the stochastic process associated with filling the target with cargo. The latter can be modeled as a Poisson process in which the time-dependent rate of filling λ(t) depends on the concentration of stationary particles within the target domain. Hence, we refer to the target as a Poisson trap. We analyze the efficiency of filling the Poisson trap with n particles in terms of the waiting time density f n(t). The latter is determined by the integrated Poisson rate μ(t)=0tλ(s)ds, which in turn depends on the solution to the reaction-hyperbolic equations. We obtain an approximate solution for the particle concentrations by reducing the system of reaction-hyperbolic equations to a scalar advection-diffusion equation using a quasisteady-state analysis. We compare our analytical results for the

  6. Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment

    Science.gov (United States)

    Majaron, Boris; Svaasand, Lars O.; Aguilar, Guillermo; Nelson, J. Stuart

    2002-09-01

    Fast heat extraction is critically important to obtain the maximal benefit of cryogen spray cooling (CSC) during laser therapy of shallow skin lesions, such as port wine stain birthmarks. However, a film of liquid cryogen can build up on the skin surface, impairing heat transfer due to the relatively low thermal conductivity and higher temperature of the film as compared to the impinging spray droplets. In an attempt to optimize the cryogen mass flux, while minimally affecting other spray characteristics, we apply a series of 10 ms spurts with variable duty cycles. Heat extraction dynamics during such intermittent cryogen sprays were measured using a custom-made metal-disc detector. The highest cooling rates were observed at moderate duty cycle levels. This confirms the presence, and offers a practical way to eliminate the adverse effect of liquid cryogen build-up on the sprayed surface. On the other hand, lower duty cycles allow a substantial reduction in the average rate of heat extraction, enabling less aggressive and more efficient CSC for treatment of deeper targets, such as hair follicles.

  7. On Optimal Harvesting Problems in Random Environments

    CERN Document Server

    Song, Qingshuo; Zhu, Chao

    2010-01-01

    This paper investigates the optimal harvesting strategy for a single species living in random environments, whose growth is given by a regime-switching diffusion. Harvesting is introduced as a stochastic control. The objective is to find a harvesting strategy which maximizes the expected total discounted income from harvesting up to extinction. This is a singular stochastic control problem, with both the extinction time and harvesting policy depending on the initial condition. Consequently one no longer obtains continuity of the value function for free using the standard arguments as those in regular or singular stochastic control problems. This paper provides a sufficient condition under which the continuity of the value function is obtained. Further, we show that the value function is a viscosity solution of a coupled system of quasi-variational inequalities. A verification theorem is also established. Based upon the verification theorem, we explicitly construct an $\\varepsilon$-optimal harvesting strategy ...

  8. Dots, clumps and filaments: the intermittent images of synchrotron emission in random magnetic fields of young supernova remnants

    CERN Document Server

    Bykov, Andrei M; Ellison, Donald C

    2008-01-01

    Non-thermal X-ray emission in some supernova remnants originates from synchrotron radiation of ultra-relativistic particles in turbulent magnetic fields. We address the effect of a random magnetic field on synchrotron emission images and spectra. A random magnetic field is simulated to construct synchrotron emission maps of a source with a steady distribution of ultra-relativistic electrons. Non-steady localized structures (dots, clumps and filaments), in which the magnetic field reaches exceptionally high values, typically arise in the random field sample. These magnetic field concentrations dominate the synchrotron emission (integrated along the line of sight) from the highest energy electrons in the cut-off regime of the distribution, resulting in an evolving, intermittent, clumpy appearance. The simulated structures resemble those observed in X-ray images of some young supernova remnants. The lifetime of X-ray clumps can be short enough to be consistent with that observed even in the case of a steady part...

  9. A prospective, randomized, blinded-endpoint, controlled study - continuous epidural infusion versus programmed intermittent epidural bolus in labor analgesia

    Directory of Open Access Journals (Sweden)

    Joana Nunes

    Full Text Available Abstract Background: There is evidence that administration of a programmed intermittent epidural bolus (PIEB compared to continuous epidural infusion (CEI leads to greater analgesia efficacy and maternal satisfaction with decreased anesthetic interventions. Methods: In this study, 166 women with viable pregnancies were included. After an epidural loading dose of 10 mL with Ropivacaine 0.16% plus Sufentanil 10 µg, parturient were randomly assigned to one of three regimens: A - Ropivacaine 0.15% plus Sufentanil 0.2 µg/mL solution as continuous epidural infusion (5 mL/h, beginning immediately after the initial bolus; B - Ropivacaine 0.1% plus Sufentanil 0.2 µg/mL as programmed intermittent epidural bolus and C - Same solution as group A as programmed intermittent epidural bolus. PIEB regimens were programmed as 10 mL/h starting 60 min after the initial bolus. Rescue boluses of 5 mL of the same solution were administered, with the infusion pump. We evaluated maternal satisfaction using a verbal numeric scale from 0 to 10. We also evaluated adverse, maternal and neonatal outcomes. Results: We analyzed 130 pregnants (A = 60; B = 33; C = 37. The median verbal numeric scale for maternal satisfaction was 8.8 in group A; 8.6 in group B and 8.6 in group C (p = 0.83. We found a higher caesarean delivery rate in group A (56.7%; p = 0.02. No differences in motor block, instrumental delivery rate and neonatal outcomes were observed. Conclusions: Maintenance of epidural analgesia with programmed intermittent epidural bolus is associated with a reduced incidence of caesarean delivery with equally high maternal satisfaction and no adverse outcomes.

  10. A Non-Inferiority, Individually Randomized Trial of Intermittent Screening and Treatment versus Intermittent Preventive Treatment in the Control of Malaria in Pregnancy.

    Directory of Open Access Journals (Sweden)

    Harry Tagbor

    Full Text Available The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT and treatment of positive women (ISTp is an alternative approach.An open, individually randomized, non-inferiority trial of IPTp-SP versus ISTp was conducted in 5,354 primi- or secundigravidae in four West African countries with a low prevalence of resistance to SP (The Gambia, Mali, Burkina Faso and Ghana. Women in the IPTp-SP group received SP on two or three occasions whilst women in the ISTp group were screened two or three times with a RDT and treated if positive for malaria with artemether-lumefantrine (AL. ISTp-AL was non-inferior to IPTp-SP in preventing low birth weight (LBW, anemia and placental malaria, the primary trial endpoints. The prevalence of LBW was 15.1% and 15.6% in the IPTp-SP and ISTp-AL groups respectively (OR = 1.03 [95% CI: 0.88, 1.22]. The mean hemoglobin concentration at the last clinic attendance before delivery was 10.97g/dL and 10.94g/dL in the IPTp-SP and ISTp-AL groups respectively (mean difference: -0.03 g/dL [95% CI: -0.13, +0.06]. Active malaria infection of the placenta was found in 24.5% and in 24.2% of women in the IPTp-SP and ISTp-AL groups respectively (OR = 0.95 [95% CI 0.81, 1.12]. More women in the ISTp-AL than in the IPTp-SP group presented with malaria parasitemia between routine antenatal clinics (310 vs 182 episodes, rate difference: 49.4 per 1,000 pregnancies [95% CI 30.5, 68.3], but the number of hospital admissions for malaria was similar in the two groups.Despite low levels of resistance to SP in the study areas, ISTp-AL performed as well as IPTp-SP. In the absence of an effective alternative medication to SP for IPTp, ISTp-AL is a potential alternative to IPTp in areas where SP resistance is high. It may also have a role in areas where malaria

  11. Randomized controlled trial for intermittent versus continuous propofol sedation for pediatric brain and spine magnetic resonance imaging studies.

    Science.gov (United States)

    Hassan, Nabil E; Betz, Bradford W; Cole, Morgan R; Wincek, Jeni; Reischman, Diann; Sanfilippo, Dominic J; Winterhalter-Rzeszutko, Kim M; Kopec, John S

    2011-11-01

    Intermittent bolus propofol is an effective agent for pediatric magnetic resonance imaging sedation but requires constant vigilance and dose titration. Magnetic resonance imaging-compatible infusion pumps may make it possible to continuously infuse propofol, achieving a steady level of sedation at a lower total dose. This study investigates total propofol dose, recovery time, and magnetic resonance image quality in children receiving intermittent vs. continuously infused propofol sedation in children undergoing brain and spine magnetic resonance imaging studies. An open-label, prospective, randomized, controlled study. A single-blinded radiologist rated the quality of magnetic resonance images. Children's hospital pediatric radiology sedation center. One hundred seventy children age 1 month to 18 yrs undergoing deep sedation for brain, spine, or both brain and spine magnetic resonance imaging. After informed consent, patients were randomly assigned to two groups: group 1 (intermittent) received a propofol bolus of 2-4 mg/kg, followed by repeat boluses of 0.5-2 mg/kg/dose as needed. Group C (continuous) received a bolus of propofol 2-4 mg/kg, followed by a continuous infusion of 100 μg/kg/min with 1-mg/kg/dose boluses with drip titration to effect. Patient demographics, sedation risk assessment, propofol dose, sedation recovery times, incidence of complications, and quality of the magnetic resonance imaging studies were measured. A total of 170 children were enrolled in the study, with 75 in group C and 95 in group I. Both groups were similar with regard to age, weight, gender, and magnetic resonance imaging study type. Group C required a lesser dose of propofol (132 ± 54 μg/kg/min) compared to (162 ± 74 μg/kg/min) in that required in group I (p = .018). There were no differences between the two groups with regard to quality of the imaging study, recovery time, or incidence of complications. Compared to intermittent bolus dosing, continuous propofol infusion

  12. Optimal work-rest cycles for an isometric intermittent gripping task as a function of force, posture and grip span.

    Science.gov (United States)

    Eksioglu, Mahmut

    2006-02-10

    The aim of this study was to investigate the maximum acceptable contraction frequencies (i.e. work-rest cycles) for an isometric-intermittent handgrip task as a function of grip span, applied force and shoulder posture using psychophysical and physiological approaches. Twelve healthy males served as subjects. The three grip spans investigated were the optimal, 2 cm narrower than the optimal, and 2 cm wider than the optimal. The grip force levels studied were 15% and 30% of maximum voluntary grip force and the two shoulder postures were 25 degrees flexion and 30 degrees abduction. The psychophysical results indicate that subjects work faster with the narrower grip span at 15% of maximum voluntary grip force level in comparison to working with the optimal and the wider spans. However, when the task required 30% of maximum grip force level, the subjects worked faster with the optimal grip span. These findings were supported by the results of electromyography, heart rate, blood pressure and perceived discomfort. The study suggests that grip span of a tool is an important factor to be considered in predicting optimal work-rest cycles for hand grip tasks, and the optimum setting of grip span of the hand-tool depends on the required task force level. That is, the optimality is relative rather than absolute. In addition, it appears that weaker subjects can work at a higher rate than stronger ones at the same relative force level.

  13. Spatial optimization of an ideal wind energy system as a response to the intermittency of renewable energies?

    Science.gov (United States)

    Lassonde, Sylvain; Boucher, Olivier; Breon, François-Marie; Tobin, Isabelle; Vautard, Robert

    2016-04-01

    The share of renewable energies in the mix of electricity production is increasing worldwide. This trend is driven by environmental and economic policies aiming at a reduction of greenhouse gas emissions and an improvement of energy security. It is expected to continue in the forthcoming years and decades. Electricity production from renewables is related to weather and climate factors such as the diurnal and seasonal cycles of sunlight and wind, but is also linked to variability on all time scales. The intermittency in the renewable electricity production (solar, wind power) could eventually hinder their future deployment. Intermittency is indeed a challenge as demand and supply of electricity need to be balanced at any time. This challenge can be addressed by the deployment of an overcapacity in power generation (from renewable and/or thermal sources), a large-scale energy storage system and/or improved management of the demand. The main goal of this study is to optimize a hypothetical renewable energy system at the French and European scales in order to investigate if spatial diversity of the production (here electricity from wind energy) could be a response to the intermittency. We use ECMWF (European Centre for Medium-Range Weather Forecasts) ERA-interim meteorological reanalysis and meteorological fields from the Weather Research and Forecasts (WRF) model to estimate the potential for wind power generation. Electricity demand and production are provided by the French electricity network (RTE) at the scale of administrative regions for years 2013 and 2014. Firstly we will show how the simulated production of wind power compares against the measured production at the national and regional scale. Several modelling and bias correction methods of wind power production will be discussed. Secondly, we will present results from an optimization procedure that aims to minimize some measure of the intermittency of wind energy. For instance we estimate the optimal

  14. A Prospective, Randomized, Crossover, Multicenter Study Comparing Quality of Life Using Compact versus Standard Catheters for Intermittent Self-Catheterization

    DEFF Research Database (Denmark)

    Chartier-Kastler, Emmanuel; Amarenco, Gérard; Lindbo, Lena

    2013-01-01

    Intermittent catheterization is the recommended standard treatment for neurogenic bladder dysfunction. However, standard intermittent catheters can be unwieldy, difficult to use and carry discreetly. This can influence patient ability to perform catheterization efficiently, discreetly and private......, therefore, affecting patient quality of life. We evaluated whether the discreet design of the compact catheter would improve quality of life in intermittent catheterization users compared with standard catheters....

  15. Randomized trial of piperaquine with sulfadoxine-pyrimethamine or dihydroartemisinin for malaria intermittent preventive treatment in children.

    Directory of Open Access Journals (Sweden)

    Badara Cisse

    Full Text Available BACKGROUND: The long terminal half life of piperaquine makes it suitable for intermittent preventive treatment for malaria but no studies of its use for prevention have been done in Africa. We did a cluster randomized trial to determine whether piperaquine in combination with either dihydroartemisin (DHA or sulfadoxine-pyrimethamine (SP is as effective, and better tolerated, than SP plus amodiaquine (AQ, when used for intermittent preventive treatment in children delivered by community health workers in a rural area of Senegal. METHODS: Treatments were delivered to children 3-59 months of age in their homes once per month during the transmission season by community health workers. 33 health workers, each covering about 60 children, were randomized to deliver either SP+AQ, DHA+PQ or SP+PQ. Primary endpoints were the incidence of attacks of clinical malaria, and the incidence of adverse events. RESULTS: 1893 children were enrolled. Coverage of monthly rounds and compliance with daily doses was similar in all groups; 90% of children received at least 2 monthly doses. Piperaquine combinations were better tolerated than SP+AQ with a significantly lower risk of common, mild adverse events. 103 episodes of clinical malaria were recorded during the course of the trial. 68 children had malaria with parasitaemia >3000/microL, 29/671 (4.3% in the SP+AQ group, compared with 22/604 (3.6% in the DHA+PQ group (risk difference 0.47%, 95%CI -2.3%,+3.3%, and 17/618 (2.8% in the SP+PQ group (risk difference 1.2%, 95%CI -1.3%,+3.6%. Prevalences of parasitaemia and the proportion of children carrying Pfdhfr and Pfdhps mutations associated with resistance to SP were very low in all groups at the end of the transmission season. CONCLUSIONS: Seasonal IPT with SP+PQ in children is highly effective and well tolerated; the combination of two long-acting drugs is likely to impede the emergence of resistant parasites. TRIAL REGISTRATION: ClinicalTrials.gov NCT00529620.

  16. Time optimization in the intermittent handing%间歇过滤操作时间优化

    Institute of Scientific and Technical Information of China (English)

    卫阳; 胡明

    2001-01-01

    The pigment impurity was removed by adding active carbon in the phytic acid serous solution.The process used imtermittent filtration operation,and proceeding optimization of the operation time.(1)optimal time of maximum output in agreement with (dv)/(dt)=(v)/(t0+t);(2)optimal time of minimum cost in agreement with (dv)/(dt)=(v)/(t+(a0t0+a1)/a).The experiment results show the feasibility of the optimization method used in the process as well as in other intermittent handing.%利用活性碳,通过间歇过滤操作,除去植酸浆液的色素杂质,对过滤时间进行优化,使产量最大的优化时间t应满足(dv)/(dt)=(v)/(t0+t);使成本最低的优化时间t应满足(dv)/(dt)=(v)/(t+(a0t0+a1)/a) 。通过实验验证,该方法是切实可行的。该法也适用于其它间歇操作时间优化。

  17. Portfolio optimization and the random magnet problem

    Science.gov (United States)

    Rosenow, B.; Plerou, V.; Gopikrishnan, P.; Stanley, H. E.

    2002-08-01

    Diversification of an investment into independently fluctuating assets reduces its risk. In reality, movements of assets are mutually correlated and therefore knowledge of cross-correlations among asset price movements are of great importance. Our results support the possibility that the problem of finding an investment in stocks which exposes invested funds to a minimum level of risk is analogous to the problem of finding the magnetization of a random magnet. The interactions for this "random magnet problem" are given by the cross-correlation matrix C of stock returns. We find that random matrix theory allows us to make an estimate for C which outperforms the standard estimate in terms of constructing an investment which carries a minimum level of risk.

  18. A non-inferiority, individually randomized trial of intermittent screening and treatment versus intermittent preventive treatment in the control of malaria in pregnancy

    DEFF Research Database (Denmark)

    Tagbor, Harry; Cairns, Matthew; Bojang, Kalifa;

    2015-01-01

    BACKGROUND: The efficacy of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine (IPTp-SP) in pregnancy is threatened in parts of Africa by the emergence and spread of resistance to SP. Intermittent screening with a rapid diagnostic test (RDT) and treatment of positive women......). Women in the IPTp-SP group received SP on two or three occasions whilst women in the ISTp group were screened two or three times with a RDT and treated if positive for malaria with artemether-lumefantrine (AL). ISTp-AL was non-inferior to IPTp-SP in preventing low birth weight (LBW), anemia......-AL performed as well as IPTp-SP. In the absence of an effective alternative medication to SP for IPTp, ISTp-AL is a potential alternative to IPTp in areas where SP resistance is high. It may also have a role in areas where malaria transmission is low and for the prevention of malaria in HIV positive women...

  19. Random walk in genome space: A key ingredient of intermittent dynamics of community assembly on evolutionary time scales

    KAUST Repository

    Murase, Yohsuke

    2010-06-01

    Community assembly is studied using individual-based multispecies models. The models have stochastic population dynamics with mutation, migration, and extinction of species. Mutants appear as a result of mutation of the resident species, while migrants have no correlation with the resident species. It is found that the dynamics of community assembly with mutations are quite different from the case with migrations. In contrast to mutation models, which show intermittent dynamics of quasi-steady states interrupted by sudden reorganizations of the community, migration models show smooth and gradual renewal of the community. As a consequence, instead of the 1/f diversity fluctuations found for the mutation models, 1/f2, random-walk like fluctuations are observed for the migration models. In addition, a characteristic species-lifetime distribution is found: a power law that is cut off by a "skewed" distribution in the long-lifetime regime. The latter has a longer tail than a simple exponential function, which indicates an age-dependent species-mortality function. Since this characteristic profile has been observed, both in fossil data and in several other mathematical models, we conclude that it is a universal feature of macroevolution. © 2010 Elsevier Ltd.

  20. A prospective randomized comparison of continuous hemihepatic with intermittent total hepatic inflow occlusion in hepatectomy for liver tumors.

    Science.gov (United States)

    Liang, Guanlin; Wen, Tianfu; Yan, Lunan; Li, B O; Wu, Guochang; Yang, Jian; Lu, Bo; Chen, Zheyu; Liao, Zhixue; Ran, Shun; Yu, Zhang

    2009-01-01

    To evaluate whether continuous hemihepatic inflow occlusion (HHO) during hepatectomy can be safer than and be as effective as intermittent total hepatic inflow occlusion (THO) in reducing blood loss. Eighty patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under THO (n=40) or HHO (n=40). THO was performed with periods of 20 minutes of occlusion and 5 minutes of releasing, while HHO was performed with continuous occlusion. The surface area of liver transection, amount of blood loss, measurements of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and postoperative evolution were recorded. The two groups were similar at entry in terms of preoperative liver function and in the proportion of patients experiencing major hepatectomy. The total ischemic time of the two groups was similar (p=0.37), but the operative time in the THO group was longer than in the HHO group (p=0.02). No significant difference was found between the HHO and THO group in blood loss during liver parenchyma transection (p=0.14), the elevations of ALT and AST on the first postoperative day (ALT: p=0.12; AST: p=0.66) and postoperative morbidity (p=0.35). On the basis of our findings, if it is feasible, continuous HHO is recommended for complex liver resection.

  1. Accelerated intermittent Theta Burst stimulation for suicide risk in therapy-resistant depressed patients: a randomized, sham-controlled trial.

    Directory of Open Access Journals (Sweden)

    Stefanie Desmyter

    2016-09-01

    Full Text Available Objectives We aimed to examine the effects and safety of accelerated intermittent Theta Burst Stimulation (iTBS on suicide risk in a group of treatment-resistant unipolar depressed patients, using an extensive suicide assessment scale. Methods In 50 therapy-resistant, antidepressant-free depressed patients, an intensive protocol of accelerated iTBS was applied over the left dorsolateral prefrontal cortex in a randomized, sham-controlled cross-over design. Patients received 20 iTBS sessions over 4 days. Suicide risk was assessed using the Beck Scale of Suicide ideation (BSI. Results The iTBS protocol was safe and well-tolerated. We observed a significant decrease of the BSI score over time, unrelated to active or sham stimulation and unrelated to depression-response. No worsening of suicidal ideation was observed. The effects of accelerated iTBS on mood and depression severity are reported in Duprat et al. (2016. The decrease in suicide risk lasted up to one month after baseline, even in depression non-responders. Conclusions This accelerated iTBS protocol was safe. The observed significant decrease in suicide risk was unrelated to active or sham stimulation and unrelated to depression response. Further sham-controlled research in suicidal depressed patients is necessary.(clinicaltrials.gov identifier: NCT01832805

  2. Continuous versus intermittent treatment strategies during primary HIV-1 infection: the randomized ANRS INTERPRIM Trial.

    Science.gov (United States)

    Goujard, Cécile; Emilie, Dominique; Roussillon, Caroline; Godot, Véronique; Rouzioux, Christine; Venet, Alain; Colin, Céline; Pialoux, Gilles; Girard, Pierre-Marie; Boilet, Valérie; Chaix, Marie-Laure; Galanaud, Pierre; Chene, Geneviève

    2012-09-24

    The ANRS-112 INTERPRIM trial assessed whether fixed-cycles of antiretroviral treatment interruption (ART-STI) combined or not with pegylated interferon alpha-2b (peg-IFN) could lower viral load and achieve a healthier immune system in patients diagnosed during primary HIV-1-infection (PHI). Patients were randomized to receive either continuous ART (cART) during 72 weeks, or cART during 36 weeks followed by three ART-STIs, or the same ART-STIs associated with peg-IFN during the first 14 weeks and each interruption (ART-STI-IFN). Treatment was stopped at week 72. Final evaluation was based on plasma HIV-RNA level 6 months after the last treatment interruption. Eighty-seven percent of patients achieved undetectable HIV-RNA at week 32, with no deleterious impact of sequential treatment interruptions (STIs). Viral rebounds during interruptions were lower in the ART-STI-IFN than in the ART-STI group and during the second and third interruptions compared with the first one. However, HIV-RNA levels, CD4 T-cell counts and CD4 T/CD8 T ratios were similar between groups after the 6-month interruption, with a persistent effect on CD4 T cells and total cell-associated HIV-DNA levels. Predictive factors of virological outcome were HIV-RNA and HIV-DNA levels at PHI and HIV-DNA levels at treatment interruption. HIV-specific responses did not differ between strategies and were not associated with outcome. Forty-eight percent of patients experienced treatment resumption during long-term follow-up without difference between groups. When initiated during PHI, STIs associated or not with IFN did not result in a different outcome as compared to cART. All regimens showed a high response rate and a sustained immunological benefit after cessation.

  3. Decoherence in optimized quantum random-walk search algorithm

    Science.gov (United States)

    Zhang, Yu-Chao; Bao, Wan-Su; Wang, Xiang; Fu, Xiang-Qun

    2015-08-01

    This paper investigates the effects of decoherence generated by broken-link-type noise in the hypercube on an optimized quantum random-walk search algorithm. When the hypercube occurs with random broken links, the optimized quantum random-walk search algorithm with decoherence is depicted through defining the shift operator which includes the possibility of broken links. For a given database size, we obtain the maximum success rate of the algorithm and the required number of iterations through numerical simulations and analysis when the algorithm is in the presence of decoherence. Then the computational complexity of the algorithm with decoherence is obtained. The results show that the ultimate effect of broken-link-type decoherence on the optimized quantum random-walk search algorithm is negative. Project supported by the National Basic Research Program of China (Grant No. 2013CB338002).

  4. Power Optimization on a Network: The effects of randomness

    CERN Document Server

    Moustakas, Aris L

    2012-01-01

    Consider a wireless network of transmitter-receiver pairs. The transmitters adjust their powers to maintain a particular SINR target in the presence of interference from neighboring transmitters. In this paper we analyze the optimal power vector that may achieve this target in the presence of randomness in the network. Specifically, we start from a regular grid of transmitter-receiver pairs and randomly turn-off a finite fraction of them. We apply concepts from random matrix theory to evaluate the asymptotic mean optimal power per link, as well as its variance. Our analytical results show remarkable agreement with numerically generated networks, not only in one-dimensional network arrays but also in two dimensional network geometries. Remarkably, we observe that the optimal power in random networks does not go to infinity in a continuous fashion as in regular grids. Rather, beyond a certain point, no finite power solution exists.

  5. Tabu search method with random moves for globally optimal design

    Science.gov (United States)

    Hu, Nanfang

    1992-09-01

    Optimum engineering design problems are usually formulated as non-convex optimization problems of continuous variables. Because of the absence of convexity structure, they can have multiple minima, and global optimization becomes difficult. Traditional methods of optimization, such as penalty methods, can often be trapped at a local optimum. The tabu search method with random moves to solve approximately these problems is introduced. Its reliability and efficiency are examined with the help of standard test functions. By the analysis of the implementations, it is seen that this method is easy to use, and no derivative information is necessary. It outperforms the random search method and composite genetic algorithm. In particular, it is applied to minimum weight design examples of a three-bar truss, coil springs, a Z-section and a channel section. For the channel section, the optimal design using the tabu search method with random moves saved 26.14 percent over the weight of the SUMT method.

  6. Optimal Marketing Policy in a Random Network

    CERN Document Server

    Amini, Hamed

    2008-01-01

    Viral marketing takes advantage of preexisting social networks among customers to achieve large changes in behavior. Models of influence spread have been studied in a number of domains, including the effect of 'word of mouth' in the promotion of new products or the diffusion of technologies. A social network can be represented by a graph where the nodes are individuals and the edges indicate a form of social relationship. The flow of influence through this network can be thought of as an increasing process of active nodes: as individuals become aware of new technologies, they have the potential to pass them on to their neighbors. The goal of marketing is to trigger a large cascade of adoptions. In this paper, we present and solve an analytical model where the individuals are connected according to a large sparse random graph. Borrowing ideas and techniques from Markov random fields, we derive analytical results for various threshold models. The parameters of the model (like the initial fraction of active indi...

  7. Prospective Randomized Controlled Trial to Analyze the Effects of Intermittent Pneumatic Compression on Edema Following Autologous Femoropopliteal Bypass Surgery

    NARCIS (Netherlands)

    A. te Slaa (Alexander); D.E.J.G.J. Dolmans (Dennis); G.H. Ho (Gwan); P.G.H. Mulder (Paul); J.C.H. van der Waal (Jan); L. van der Laan (Lyckle)

    2011-01-01

    textabstractBackground: Patients who undergo autologous femoropopliteal bypass surgery develop postoperative edema in the revascularized leg. The effects of intermittent pneumatic compression (IPC) to treat and to prevent postreconstructive edema were examined in this study. Methods: In a prospectiv

  8. Optimal Operation of the Integrated Electrical and Heating Systems to Accommodate the Intermittent Renewable Sources

    DEFF Research Database (Denmark)

    Li, Jinghua; Fang, Jiakun; Zeng, Qing

    2016-01-01

    The integration of electrical and heating systems has great potential to enhance the flexibility of power systems to accommodate more renewable power such as the wind and solar. This study was to investigate an optimal way to integrate the energy of both systems in urban areas. The amount of energy...... conversion between the electrical system and heating system was optimally decided so that the demand within both systems could be met at the least operational cost. Besides, the best node to join with the electrical system and heating system was chosen by consideration of the energy transmission loss....... The mathematic formulation of the optimization problem was detailed as a large-scale non-linear program (LSNLP) in this paper. A decomposition-coordination algorithm was proposed to solve this LSNLP. At last, a 6-bus electrical power system with 31-node heating transmission system was studied to demonstrate...

  9. Optimal two qubit gate for generation of random bipartite entanglement

    CERN Document Server

    Znidaric, M

    2007-01-01

    We study protocols for generation of random pure states consisting of repeated applications of two qubit transformations. Necessary number of steps needed in order to generate states displaying bipartite entanglement typical of random states is obtained. We also find the optimal two qubit gate for which the convergence is the fastest. Perhaps surprisingly, applying the same good two qubit gate in addition to a random single qubit rotations at each step leads to a faster generation of entanglement than applying a random two qubit transformation at each step.

  10. Lack of difference between continuous versus intermittent heparin infusion on maintenance of intra-arterial catheter in postoperative pediatric surgery: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Maria Carolina Witkowski

    2013-12-01

    Full Text Available OBJECTIVE: To compare two systems of arterial catheters maintenance in postoperative pediatric surgery using intermittent or continuous infusion of heparin solution and to analyze adverse events related to the site of catheter insertion and the volume of infused heparin solution. METHODS: Randomized control trial with 140 patients selected for continuous infusion group (CIG and intermittent infusion group (IIG. The variables analyzed were: type of heart disease, permanence time and size of the catheter, insertion site, technique used, volume of heparin solution and adverse events. The descriptive variables were analyzed by Student's t-test and the categorical variables, by chi-square test, being significant p<0.05. RESULTS: The median age was 11 (0-22 months, and 77 (55% were females. No significant differences between studied variables were found, except for the volume used in CIG (12.0±1.2mL/24 hours when compared to IIG (5.3±3.5mL/24 hours with p<0.0003. CONCLUSIONS: The continuous infusion system and the intermittent infusion of heparin solution can be used for intra-arterial catheters maintenance in postoperative pediatric surgery, regardless of patient's clinical and demographic characteristics. Adverse events up to the third postoperative day occurred similarly in both groups. However, the intermittent infusion system usage in underweight children should be considered, due to the lower volume of infused heparin solution [ClinicalTrials.gov Identifier: NCT01097031].

  11. Lack of difference between continuous versus intermittent heparin infusion on maintenance of intra-arterial catheter in postoperative pediatric surgery: a randomized controlled study

    Science.gov (United States)

    Witkowski, Maria Carolina; de Moraes, Maria Antonieta P.; Firpo, Cora Maria F.

    2013-01-01

    OBJECTIVE: To compare two systems of arterial catheters maintenance in postoperative pediatric surgery using intermittent or continuous infusion of heparin solution and to analyze adverse events related to the site of catheter insertion and the volume of infused heparin solution. METHODS: Randomized control trial with 140 patients selected for continuous infusion group (CIG) and intermittent infusion group (IIG). The variables analyzed were: type of heart disease, permanence time and size of the catheter, insertion site, technique used, volume of heparin solution and adverse events. The descriptive variables were analyzed by Student's t-test and the categorical variables, by chi-square test, being significant p<0.05. RESULTS: The median age was 11 (0-22) months, and 77 (55%) were females. No significant differences between studied variables were found, except for the volume used in CIG (12.0±1.2mL/24 hours) when compared to IIG (5.3±3.5mL/24 hours) with p<0.0003. CONCLUSIONS: The continuous infusion system and the intermittent infusion of heparin solution can be used for intra-arterial catheters maintenance in postoperative pediatric surgery, regardless of patient's clinical and demographic characteristics. Adverse events up to the third postoperative day occurred similarly in both groups. However, the intermittent infusion system usage in underweight children should be considered, due to the lower volume of infused heparin solution [ClinicalTrials.gov Identifier: NCT01097031]. PMID:24473958

  12. Energy intermittency

    CERN Document Server

    Sorensen, Bent

    2014-01-01

    The first book to consider intermittency as a key point of an energy system, Energy Intermittency describes different levels of variability for traditional and renewable energy sources, presenting detailed solutions for handling energy intermittency through trade, collaboration, demand management, and active energy storage. Addressing energy supply intermittency systematically, this practical text:Analyzes typical time-distributions and intervals between episodes of demand-supply mismatch and explores their dependence on system layouts and energy source characteristicsSimulates scenarios regar

  13. Attractive and Repulsive Particle Swarm Optimization and Random Virus Algorithm for Solving Reactive Power Optimization Problem

    Directory of Open Access Journals (Sweden)

    K. Lenin

    2013-03-01

    Full Text Available Reactive Power Optimization is a complex combinatorial optimization problem involving non-linear function having multiple local minima, non-linear and discontinuous constrains. This paper presents Attractive and repulsive Particle Swarm Optimization (ARPSO and Random Virus Algorithm (RVA in trying to overcome the Problem of premature convergence. RVA and ARPSO is applied to Reactive Power Optimization problem and is evaluated on standard IEEE 30Bus System. The results show that RVA prevents premature convergence to high degree but still keeps a rapid convergence. It gives best solution when compared to Attractive and repulsive Particle Swarm Optimization (ARPSO and Particle Swarm Optimization (PSO.

  14. Randomized Optimal Consensus of Multi-agent Systems

    CERN Document Server

    Shi, Guodong

    2011-01-01

    In this paper, we formulate and solve a randomized optimal consensus problem for multi-agent systems with stochastically time-varying interconnection topology. The considered multi-agent system with a simple randomized iterating rule achieves an almost sure consensus meanwhile solving the optimization problem $\\min_{z\\in \\mathds{R}^d}\\ \\sum_{i=1}^n f_i(z),$ in which the optimal solution set of objective function $f_i$ corresponding to agent $i$ can only be observed by agent $i$ itself. At each time step, each agent independently and randomly chooses either taking an average among its neighbor set, or projecting onto the optimal solution set of its own optimization component. Both directed and bidirectional communication graphs are studied. Connectivity conditions are proposed to guarantee an optimal consensus almost surely with proper convexity and intersection assumptions. The convergence analysis is carried out using convex analysis. The results illustrate that a group of autonomous agents can reach an opti...

  15. Theory of Randomized Search Heuristics in Combinatorial Optimization

    DEFF Research Database (Denmark)

    The rigorous mathematical analysis of randomized search heuristics(RSHs) with respect to their expected runtime is a growing research area where many results have been obtained in recent years. This class of heuristics includes well-known approaches such as Randomized Local Search (RLS), the Metr......The rigorous mathematical analysis of randomized search heuristics(RSHs) with respect to their expected runtime is a growing research area where many results have been obtained in recent years. This class of heuristics includes well-known approaches such as Randomized Local Search (RLS...... analysis of randomized algorithms to RSHs. Mostly, the expected runtime of RSHs on selected problems is analzyed. Thereby, we understand why and when RSHs are efficient optimizers and, conversely, when they cannot be efficient. The tutorial will give an overview on the analysis of RSHs for solving...

  16. Strategies for optimal penetration of intermittent renewables in complex energy systems based on techno-operational objectives

    Energy Technology Data Exchange (ETDEWEB)

    Franco, Alessandro; Salza, Pasquale [Dipartimento di Energetica ' ' L. Poggi' ' , Universita di Pisa, Largo Lucio Lazzarino, 2, 56126 PISA (Italy)

    2011-02-15

    Renewable energy sources (RES) are mainly used in the electrical sector. Electricity is not a storable commodity. Hence it is necessary to produce the requested quantity and distribute it through the system in such a way as to ensure that electricity supply and demand are always evenly balanced. This constraint is actually the main problem related to the penetration of new renewables (wind and photovoltaic power) in the context of complex energy systems. Moreover the design of optimal energy resource mixes in climate change mitigation actions is a challenge faced in many places. The paper analyzes the problem of new renewable energy sources penetration. The case of Italian scenario is considered as a meaningful reference due to the characteristic size and the complexity of the same. The various energy scenarios are evaluated with the aid of a multipurpose software taking into account the interconnections between the different energetic uses. In particular it is shown how the penetration of new renewable energy sources is limited at an upper level by technological considerations and it will be more sustainable if an integration of the various energy uses (thermal, mobility and electrical) will be considered. A series of optimized scenarios are developed. In each case the maximum RES penetration feasible with the constraints was defined. Then analysis is applied to an energy system model of Italy showing how an integrated development of CHP and electric mobility can aid a further integration of wind and photovoltaic energy power. Finally the primary energy consumption saving possible in case of consistent penetration of intermittent renewables and CHP was identified. (author)

  17. Optimization, ex vivo permeation, and stability study of lipid nanocarrier loaded gelatin capsules for treatment of intermittent claudication

    Directory of Open Access Journals (Sweden)

    Sallam MA

    2015-07-01

    Full Text Available Marwa Ahmed Sallam,1 María Teresa Marín Boscá21Department of Industrial Pharmacy, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt; 2Department of Pharmacy and Pharmaceutical Technology, Faculty of Pharmacy, Granada University, Granada, Spain Abstract: In this study, an optimized nanodispersible oral dosage form (containing a lactate ester was developed for cilostazol (CZL. CZL is a phosphodiesterase inhibitor used for intermittent claudication. We aimed to improve the dissolution rate and absorption of CZL giving it a better chance of oral bioavailability, and to evaluate its stability on storage. Suitable compositions of nanoemulsion preconcentrate formulations were screened via solubility and compatibility tests. Response surface methodology and a desirability approach were applied to optimize preconcentrates containing minimum amount of surfactant mixture, maximum amount of lipid, and possessing the smallest globule size, with the highest emulsification and dissolution rates and minimum risk of drug precipitation. As part of the optimization process, the main effect, interaction effects and quadratic effects of amounts of lipid, and surfactant/co-surfactant ratio on % transmittance, globule size, emulsification time, drug precipitation, and drug release were investigated. The optimized formulation consisting of 28.9% butyl lactate, 28.9% Capryol®, 27.82% Solubilisant Gamma® 2429, and 14.18% Transcutol® possessing a globule size of 60 nm was mixed with Aerosil® 200. This gave uniform free flowing granules, which were characterized for surface and powder properties. The self-nanoemulsifying granules (SNEGs filled into hard gelatin capsules showed two- and threefold increase in CZL released compared with conventional tablet and pure drug, respectively. The amount of drug permeated using non-everted sac technique from the SNEGs was twofold higher than that permeated from the tablet suspension. The shelf life was 526 days at

  18. Near-Optimal Random Walk Sampling in Distributed Networks

    CERN Document Server

    Sarma, Atish Das; Pandurangan, Gopal

    2012-01-01

    Performing random walks in networks is a fundamental primitive that has found numerous applications in communication networks such as token management, load balancing, network topology discovery and construction, search, and peer-to-peer membership management. While several such algorithms are ubiquitous, and use numerous random walk samples, the walks themselves have always been performed naively. In this paper, we focus on the problem of performing random walk sampling efficiently in a distributed network. Given bandwidth constraints, the goal is to minimize the number of rounds and messages required to obtain several random walk samples in a continuous online fashion. We present the first round and message optimal distributed algorithms that present a significant improvement on all previous approaches. The theoretical analysis and comprehensive experimental evaluation of our algorithms show that they perform very well in different types of networks of differing topologies. In particular, our results show h...

  19. How Well Do Randomized Controlled Trials Reflect Standard Care: A Comparison between Scientific Research Data and Standard Care Data in Patients with Intermittent Claudication undergoing Supervised Exercise Therapy.

    Directory of Open Access Journals (Sweden)

    S Dörenkamp

    Full Text Available The aim of the present study was to assess the degree and impact of patient selection of patients with intermittent claudication undergoing supervised exercise therapy in Randomized Controlled Trials (RCTs by describing commonly used exclusion criteria, and by comparing baseline characteristics and treatment response measured as improvement in maximum walking distance of patients included in RCTs and patients treated in standard care.We compared data from RCTs with unselected standard care data. First, we systematically reviewed RCTs that investigated the effect of supervised exercise therapy in patients with intermittent claudication. For each of the RCTs, we extracted and categorized the eligibility criteria and their justifications. To assess whether people in RCTs (n = 1,440 differed from patients treated in daily practice (n = 3,513, in terms of demographics, comorbidity and walking capacity, we assessed between group-differences using t-tests. To assess differences in treatment response, we compared walking distances at three and six months between groups using t-tests. Differences of ≥15% were set as a marker for a clinically relevant difference.All 20 included RCTs excluded large segments of patients with intermittent claudication. One-third of the RCTs eligibility criteria were justified. Despite, the numerous eligibility criteria, we found that baseline characteristics were largely comparable. A statistically significant and (borderline clinically relevant difference in treatment response after three and six months between trial participants and standard care patients was found. Improvements in maximum walking distance after three and six months were significantly and clinically less in trial participants.The finding that baseline characteristics of patients included in RCTs and patients treated in standard care were comparable, may indicate that RCT eligibility criteria are used implicitly by professionals when referring patients to

  20. Optimization by GRASP greedy randomized adaptive search procedures

    CERN Document Server

    Resende, Mauricio G C

    2016-01-01

    This is the first book to cover GRASP (Greedy Randomized Adaptive Search Procedures), a metaheuristic that has enjoyed wide success in practice with a broad range of applications to real-world combinatorial optimization problems. The state-of-the-art coverage and carefully crafted pedagogical style lends this book highly accessible as an introductory text not only to GRASP, but also to combinatorial optimization, greedy algorithms, local search, and path-relinking, as well as to heuristics and metaheuristics, in general. The focus is on algorithmic and computational aspects of applied optimization with GRASP with emphasis given to the end-user, providing sufficient information on the broad spectrum of advances in applied optimization with GRASP. For the more advanced reader, chapters on hybridization with path-relinking and parallel and continuous GRASP present these topics in a clear and concise fashion. Additionally, the book offers a very complete annotated bibliography of GRASP and combinatorial optimizat...

  1. Optimizing Event Selection with the Random Grid Search

    Energy Technology Data Exchange (ETDEWEB)

    Bhat, Pushpalatha C. [Fermilab; Prosper, Harrison B. [Florida State U.; Sekmen, Sezen [Kyungpook Natl. U.; Stewart, Chip [Broad Inst., Cambridge

    2017-06-29

    The random grid search (RGS) is a simple, but efficient, stochastic algorithm to find optimal cuts that was developed in the context of the search for the top quark at Fermilab in the mid-1990s. The algorithm, and associated code, have been enhanced recently with the introduction of two new cut types, one of which has been successfully used in searches for supersymmetry at the Large Hadron Collider. The RGS optimization algorithm is described along with the recent developments, which are illustrated with two examples from particle physics. One explores the optimization of the selection of vector boson fusion events in the four-lepton decay mode of the Higgs boson and the other optimizes SUSY searches using boosted objects and the razor variables.

  2. Intermittent preventive treatment of malaria in pregnancy with mefloquine in HIV-negative women: a multicentre randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Raquel González

    2014-09-01

    Full Text Available Intermittent preventive treatment in pregnancy (IPTp with sulfadoxine-pyrimethamine (SP is recommended by WHO to prevent malaria in African pregnant women. The spread of SP parasite resistance has raised concerns regarding long-term use for IPT. Mefloquine (MQ is the most promising of available alternatives to SP based on safety profile, long half-life, and high efficacy in Africa. We evaluated the safety and efficacy of MQ for IPTp compared to those of SP in HIV-negative women.A total of 4,749 pregnant women were enrolled in an open-label randomized clinical trial conducted in Benin, Gabon, Mozambique, and Tanzania comparing two-dose MQ or SP for IPTp and MQ tolerability of two different regimens. The study arms were: (1 SP, (2 single dose MQ (15 mg/kg, and (3 split-dose MQ in the context of long lasting insecticide treated nets. There was no difference on low birth weight prevalence (primary study outcome between groups (360/2,778 [13.0%] for MQ group and 177/1,398 (12.7% for SP group; risk ratio [RR], 1.02 (95% CI 0.86-1.22; p=0.80 in the ITT analysis. Women receiving MQ had reduced risks of parasitemia (63/1,372 [4.6%] in the SP group and 88/2,737 [3.2%] in the MQ group; RR, 0.70 [95% CI 0.51-0.96]; p=0.03 and anemia at delivery (609/1,380 [44.1%] in the SP group and 1,110/2743 [40.5%] in the MQ group; RR, 0.92 [95% CI 0.85-0.99]; p=0.03, and reduced incidence of clinical malaria (96/551.8 malaria episodes person/year [PYAR] in the SP group and 130/1,103.2 episodes PYAR in the MQ group; RR, 0.67 [95% CI 0.52-0.88]; p=0.004 and all-cause outpatient attendances during pregnancy (850/557.8 outpatients visits PYAR in the SP group and 1,480/1,110.1 visits PYAR in the MQ group; RR, 0.86 [0.78-0.95]; p=0.003. There were no differences in the prevalence of placental infection and adverse pregnancy outcomes between groups. Tolerability was poorer in the two MQ groups compared to SP. The most frequently reported related adverse events were dizziness

  3. Near-Optimal Sublinear Time Bounds for Distributed Random Walks

    CERN Document Server

    Sarma, Atish Das; Pandurangan, Gopal; Tetali, Prasad

    2009-01-01

    We focus on the problem of performing random walks efficiently in a distributed network. Given bandwidth constraints, the goal is to minimize the number of rounds required to obtain a random walk sample on an undirected network. Despite the widespread use of random walks in distributed computing, most algorithms that compute a random walk sample of length $\\ell$ naively, i.e., in $O(\\ell)$ rounds. Recently, the first sublinear time distributed algorithm was presented that ran in $\\tilde{O}(\\ell^{2/3}D^{1/3})$ rounds {$\\tilde{O}$ hides polylog factors in the number of nodes in the network} where $D$ is the diameter of the network [Das Sarma et al. PODC 2009]. This work further conjectured that a running time of $\\tilde{O}(\\sqrt{\\ell D})$ is possible and that this is essentially optimal. In this paper, we resolve these conjectures by showing almost tight bounds on distributed random walks. We present a distributed algorithm that performs a random walk of length $\\ell$ in $\\tilde{O}(\\sqrt{\\ell D})$ rounds, where...

  4. Order-Optimal Consensus through Randomized Path Averaging

    CERN Document Server

    Benezit, F; Thiran, P; Vetterli, M

    2008-01-01

    Gossip algorithms have recently received significant attention, mainly because they constitute simple and robust message-passing schemes for distributed information processing over networks. However for many topologies that are realistic for wireless ad-hoc and sensor networks (like grids and random geometric graphs), the standard nearest-neighbor gossip converges as slowly as flooding ($O(n^2)$ messages). A recently proposed algorithm called geographic gossip improves gossip efficiency by a $\\sqrt{n}$ factor, by exploiting geographic information to enable multi-hop long distance communications. In this paper we prove that a variation of geographic gossip that averages along routed paths, improves efficiency by an additional $\\sqrt{n}$ factor and is order optimal ($O(n)$ messages) for grids and random geometric graphs. We develop a general technique (travel agency method) based on Markov chain mixing time inequalities, which can give bounds on the performance of randomized message-passing algorithms operating...

  5. Optimization of MIMO Systems Capacity Using Large Random Matrix Methods

    Directory of Open Access Journals (Sweden)

    Philippe Loubaton

    2012-11-01

    Full Text Available This paper provides a comprehensive introduction of large random matrix methods for input covariance matrix optimization of mutual information of MIMO systems. It is first recalled informally how large system approximations of mutual information can be derived. Then, the optimization of the approximations is discussed, and important methodological points that are not necessarily covered by the existing literature are addressed, including the strict concavity of the approximation, the structure of the argument of its maximum, the accuracy of the large system approach with regard to the number of antennas, or the justification of iterative water-filling optimization algorithms. While the existing papers have developed methods adapted to a specific model, this contribution tries to provide a unified view of the large system approximation approach.

  6. Comprehensive Optimal Allocation of Intermittent Distributed Generation Considering Reactive Power Compensation%考虑无功补偿影响因素的间歇性分布式电源综合优化配置

    Institute of Scientific and Technical Information of China (English)

    邓威; 李欣然; 刘志勇; 颜艳丽; 李金鑫; 马亚辉

    2012-01-01

    针对分布式风电(distributedwindgeneration,DWG)、光伏电池(photovoltaic,PV)等间歇性分布式电源(distributedgeneration,DG)输出功率的随机性以及负荷的不确定性。采用机会约束规划方法,以间歇性DG与补偿电容的投资支出、售电收益、系统降损收益、电压质量以及废气减排量综合效益为目标函数,建立间歇性DG与补偿电容的综合最优配置模型,并选择遗传算法进行最优求解。算例结果表明,其综合最优方案能提高节点电压期望水平及其处于正常范围内的概率,实现了经济效益、环境效益以及电压质量的综合最优,验证了所建模型的合理性和有效性。%The output power of intermittent distributed generation (DG) such as distributed wind generation (DWG) and photovoltaic (PV) is random and the load is uncertain. Aiming at the investment expenses of intermittent DG and compensation capacitor, income of electricity sale, reduction of system power loss, voltage quality and emission reductions, the optimal configuration models of intermittent DG and capacitor were built using chance constrained programming method. Genetic algorithm was chosen for the optimal solution. The simulation results show that the comprehensively optimized allocation model has improved expected value of node voltage and the probability within normal range. The comprehensive optimization of economic benefit, environ-mental benefit and voltage quality were achieved, and the rationality and availability of the proposed model is verified.

  7. Inner Random Restart Genetic Algorithm for Practical Delivery Schedule Optimization

    Science.gov (United States)

    Sakurai, Yoshitaka; Takada, Kouhei; Onoyama, Takashi; Tsukamoto, Natsuki; Tsuruta, Setsuo

    A delivery route optimization that improves the efficiency of real time delivery or a distribution network requires solving several tens to hundreds but less than 2 thousands cities Traveling Salesman Problems (TSP) within interactive response time (less than about 3 second), with expert-level accuracy (less than about 3% of error rate). Further, to make things more difficult, the optimization is subjects to special requirements or preferences of each various delivery sites, persons, or societies. To meet these requirements, an Inner Random Restart Genetic Algorithm (Irr-GA) is proposed and developed. This method combines meta-heuristics such as random restart and GA having different types of simple heuristics. Such simple heuristics are 2-opt and NI (Nearest Insertion) methods, each applied for gene operations. The proposed method is hierarchical structured, integrating meta-heuristics and heuristics both of which are multiple but simple. This method is elaborated so that field experts as well as field engineers can easily understand to make the solution or method easily customized and extended according to customers' needs or taste. Comparison based on the experimental results and consideration proved that the method meets the above requirements more than other methods judging from not only optimality but also simplicity, flexibility, and expandability in order for this method to be practically used.

  8. 'Help for Hay Fever', a goal-focused intervention for people with intermittent allergic rhinitis, delivered in Scottish community pharmacies: study protocol for a pilot cluster randomized controlled trial.

    Science.gov (United States)

    Porteous, Terry; Wyke, Sally; Smith, Sarah; Bond, Christine; Francis, Jill; Lee, Amanda J; Lowrie, Richard; Scotland, Graham; Sheikh, Aziz; Thomas, Mike; Smith, Lorraine

    2013-07-15

    Despite the availability of evidence-based guidelines for managing allergic rhinitis in primary care, management of the condition in the United Kingdom (UK) remains sub-optimal. Its high prevalence and negative effects on quality of life, school performance, productivity and co-morbid respiratory conditions (in particular, asthma), and high health and societal costs, make this a priority for developing novel models of care. Recent Australian research demonstrated the potential of a community pharmacy-based 'goal-focused' intervention to help people with intermittent allergic rhinitis to self-manage their condition better, reduce symptom severity and improve quality of life. In this pilot study we will assess the transferability of the goal-focused intervention to a UK context, the suitability of the intervention materials, procedures and outcome measures and collect data to inform a future definitive UK randomized controlled trial (RCT). A pilot cluster RCT with associated preliminary economic analysis and embedded qualitative evaluation. The pilot trial will take place in two Scottish Health Board areas: Grampian and Greater Glasgow & Clyde. Twelve community pharmacies will be randomly assigned to intervention or usual care group. Each will recruit 12 customers seeking advice or treatment for intermittent allergic rhinitis. Pharmacy staff in intervention pharmacies will support recruited customers in developing strategies for setting and achieving goals that aim to avoid/minimize triggers for, and eliminate/minimize symptoms of allergic rhinitis. Customers recruited in non-intervention pharmacies will receive usual care. The co-primary outcome measures, selected to inform a sample size calculation for a future RCT, are: community pharmacy and customer recruitment and completion rates; and effect size of change in the validated mini-Rhinoconjunctivitis Quality of Life Questionnaire between baseline, one-week and six-weeks post-intervention. Secondary outcome

  9. Asynchronous Code-Division Random Access Using Convex Optimization

    CERN Document Server

    Applebaum, Lorne; Duarte, Marco F; Calderbank, Robert

    2011-01-01

    Many applications in cellular systems and sensor networks involve a random subset of a large number of users asynchronously reporting activity to a base station. This paper examines the problem of multiuser detection (MUD) in random access channels for such applications. Traditional orthogonal signaling ignores the random nature of user activity in this problem and limits the total number of users to be on the order of the number of signal space dimensions. Contention-based schemes, on the other hand, suffer from delays caused by colliding transmissions and the hidden node problem. In contrast, this paper presents a novel asynchronous (non-orthogonal) code-division random access scheme along with a convex optimization-based MUD algorithm that overcomes the issues associated with orthogonal signaling and contention-based methods. Two key distinguishing features of the proposed algorithm are that it does not require knowledge of the delay or channel state information of every user and it has polynomial-time com...

  10. Remote optimal state estimation over communication channels with random delays

    KAUST Repository

    Mahmoud, Magdi S.

    2014-01-22

    This paper considers the optimal estimation of linear systems over unreliable communication channels with random delays. In this work, it is assumed that the system to be estimated is far away from the filter. The observations of the system are capsulized without time stamp and then transmitted to the network node at which the filter is located. The probabilities of time delays are assumed to be known. The event-driven estimation scheme is applied in this paper and the estimate of the states is updated only at each time instant when any measurement arrives. To capture the feature of communication, the system considered is augmented, and the arrived measurements are regarded as the uncertain observations of the augmented system. The corresponding optimal estimation algorithm is proposed and additionally, a numerical simulation represents the performance of this work. © 2014 The authors. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.

  11. Optimal state estimation over communication channels with random delays

    KAUST Repository

    Mahmoud, Magdi S.

    2013-04-01

    This paper is concerned with the optimal estimation of linear systems over unreliable communication channels with random delays. The measurements are delivered without time stamp, and the probabilities of time delays are assumed to be known. Since the estimation is time-driven, the actual time delays are converted into virtual time delays among the formulation. The receiver of estimation node stores the sum of arrived measurements between two adjacent processing time instants and also counts the number of arrived measurements. The original linear system is modeled as an extended system with uncertain observation to capture the feature of communication, then the optimal estimation algorithm of systems with uncertain observations is proposed. Additionally, a numerical simulation is presented to show the performance of this work. © 2013 The Franklin Institute.

  12. STOCHASTIC LINEAR QUADRATIC OPTIMAL CONTROL PROBLEMS WITH RANDOM COEFFICIENTS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper studies a stochastic linear quadratic optimal control problem (LQ problem, for short), for which the coefficients are allowed to be random and the cost functional is allowed to have a negative weight on the square of the control variable. The authors introduce the stochastic Riccati equation for the LQ problem. This is a backward SDE with a complicated nonlinearity and a singularity. The local solvability of such a backward SDE is established, which by no means is obvious. For the case of deterministic coefficients, some further discussions on the Riccati equations have been carried out. Finally, an illustrative example is presented.

  13. Scheduled Intermittent Screening with Rapid Diagnostic Tests and Treatment with Dihydroartemisinin-Piperaquine versus Intermittent Preventive Therapy with Sulfadoxine-Pyrimethamine for Malaria in Pregnancy in Malawi: An Open-Label Randomized Controlled Trial

    Science.gov (United States)

    Madanitsa, Mwayiwawo; Kalilani, Linda; Mwapasa, Victor; van Eijk, Anna M.; Khairallah, Carole; Ali, Doreen; Pace, Cheryl; Smedley, James; Thwai, Kyaw-Lay; Levitt, Brandt; Kang’ombe, Arthur; Faragher, Brian; Taylor, Steve M.; Meshnick, Steve; ter Kuile, Feiko O.

    2016-01-01

    Background In Africa, most plasmodium infections during pregnancy remain asymptomatic, yet are associated with maternal anemia and low birthweight. WHO recommends intermittent preventive therapy in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP). However, sulfadoxine-pyrimethamine (SP) efficacy is threatened by high-level parasite resistance. We conducted a trial to evaluate the efficacy and safety of scheduled intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with dihydroartemisinin-piperaquine (DP) as an alternative strategy to IPTp-SP. Methods and Findings This was an open-label, two-arm individually randomized superiority trial among HIV-seronegative women at three sites in Malawi with high SP resistance. The intervention consisted of three or four scheduled visits in the second and third trimester, 4 to 6 wk apart. Women in the IPTp-SP arm received SP at each visit. Women in the intermittent screening and treatment in pregnancy with DP (ISTp-DP) arm were screened for malaria at every visit and treated with DP if RDT-positive. The primary outcomes were adverse live birth outcome (composite of small for gestational age, low birthweight [<2,500 g], or preterm birth [<37 wk]) in paucigravidae (first or second pregnancy) and maternal or placental plasmodium infection at delivery in multigravidae (third pregnancy or higher). Analysis was by intention to treat. Between 21 July 2011 and 18 March 2013, 1,873 women were recruited (1,155 paucigravidae and 718 multigravidae). The prevalence of adverse live birth outcome was similar in the ISTp-DP (29.9%) and IPTp-SP (28.8%) arms (risk difference = 1.08% [95% CI −3.25% to 5.41%]; all women: relative risk [RR] = 1.04 [95% CI 0.90–1.20], p = 0.625; paucigravidae: RR = 1.10 [95% CI 0.92–1.31], p = 0.282; multigravidae: RR = 0.92 [95% CI 0.71–1.20], p = 0.543). The prevalence of malaria at delivery was higher in the ISTp-DP arm (48.7% versus 40.8%; risk difference

  14. Randomized controlled trial comparing nasal intermittent positive pressure ventilation and nasal continuous positive airway pressure in premature infants after tracheal extubation

    Directory of Open Access Journals (Sweden)

    Daniela Franco Rizzo Komatsu

    Full Text Available Summary Objective: To analyze the frequency of extubation failure in premature infants using conventional mechanical ventilation (MV after extubation in groups subjected to nasal intermittent positive pressure ventilation (nIPPV and continuous positive airway pressure (nCPAP. Method: Seventy-two premature infants with respiratory failure were studied, with a gestational age (GA ≤ 36 weeks and birth weight (BW > 750 g, who required tracheal intubation and mechanical ventilation. The study was controlled and randomized in order to ensure that the members of the groups used in the research were chosen at random. Randomization was performed at the time of extubation using sealed envelopes. Extubation failure was defined as the need for re-intubation and mechanical ventilation during the first 72 hours after extubation. Results: Among the 36 premature infants randomized to nIPPV, six (16.6% presented extubation failure in comparison to 11 (30.5% of the 36 premature infants randomized to nCPAP. There was no statistical difference between the two study groups regarding BW, GA, classification of the premature infant, and MV time. The main cause of extubation failure was the occurrence of apnea. Gastrointestinal and neurological complications did not occur in the premature infants participating in the study. Conclusion: We found that, despite the extubation failure of the group of premature infants submitted to nIPPV being numerically smaller than in premature infants submitted to nCPAP, there was no statistically significant difference between the two modes of ventilatory support after extubation.

  15. Seasonal intermittent preventive treatment for the prevention of anaemia and malaria in Ghanaian children: a randomized, placebo controlled trial.

    Directory of Open Access Journals (Sweden)

    Margaret Kweku

    Full Text Available BACKGROUND: Malaria and anaemia are the leading causes of morbidity and mortality in children in sub-Saharan Africa. We have investigated the effect of intermittent preventive treatment with sulphadoxine-pyrimethamine or artesunate plus amodiaquine on anaemia and malaria in children in an area of intense, prolonged, seasonal malaria transmission in Ghana. METHODS: 2451 children aged 3-59 months from 30 villages were individually randomised to receive placebo or artesunate plus amodiaquine (AS+AQ monthly or bimonthly, or sulphadoxine-pyrimethamine (SP bimonthly over a period of six months. The primary outcome measures were episodes of anaemia (Hb1 year old when they received IPTc compared to the placebo group. However the incidence of malaria in the post intervention period was higher in children who were <1 year old when they received AS+AQ monthly compared to the placebo group. INTERPRETATION: IPTc is safe and efficacious in reducing the burden of malaria in an area of Ghana with a prolonged, intense malaria transmission season. TRIAL REGISTRATION: ClinicalTrials.gov NCT00119132.

  16. Hormonal and metabolic stress responses after major surgery in children aged 0-3 years: a double-blind, randomized trial comparing the effects of continuous versus intermittent morphine

    NARCIS (Netherlands)

    J. Bouwmeester (Nancy); K.J.S. Anand (Kanwaljeet); M. van Dijk (Monique); W.C.J. Hop (Wim); F. Boomsma (Frans); D. Tibboel (Dick)

    2001-01-01

    textabstractChildren aged 0-3 yr were stratified for age and randomized to receive either continuous morphine (CM, 10 microg x kg(-1) x h(-1)) with three-hourly placebo boluses or intermittent morphine (IM, 30 microg x kg(-1) every 3 h) with a placebo infusion for postoperative ana

  17. Does intermittent pneumatic compression reduce the risk of post stroke deep vein thrombosis? The CLOTS 3 trial: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dennis Martin

    2012-03-01

    Full Text Available Abstract Background Approximately 80,000 patients each year are admitted to UK hospitals with an acute stroke and are immobile. At least 10% will develop a proximal Deep Vein Thrombosis in the first month and 1.5% a pulmonary embolus. Although hydration, antiplatelet treatment and early mobilisation may reduce the risk of deep vein thrombosis, there are currently no preventive strategies which have been clearly shown to be both effective and safe. Anticoagulation increases the risks of bleeding and compression stockings are ineffective. Systematic reviews of small randomized trials of intermittent pneumatic compression have shown that this reduces the risk of deep vein thrombosis in patients undergoing surgery, but that there are few data concerning its use after stroke. The CLOTS trial 3 aims to determine whether, compared with best medical care, best medical care plus intermittent pneumatic compression in immobile stroke patients reduces the risk of proximal deep vein thrombosis. Methods/Design CLOTS Trial 3 is a parallel group multicentre trial; with centralized randomisation (minimisation to ensure allocation concealment. Over 80 centres in the UK will recruit 2800 immobile stroke patients within the first 3 days of their hospital admission. Patients will be allocated to best medical care or best medical care plus intermittent pneumatic compression. Ultrasonographers will perform a Compression Duplex Ultrasound Scan to detect deep vein thrombosis in each treatment group at about 7-10 days and 25-30 days. The primary outcome cluster includes symptomatic or asymptomatic deep vein thrombosis in the popliteal or femoral veins detected on either scan. Patients are then followed up by postal or telephone questionnaire at 6 months from randomisation to detect later symptomatic deep vein thrombosis and pulmonary emboli and to establish their functional outcome (Oxford handicap scale and quality of life (EQ5D-3 L. The ultrasonographers performing the

  18. Intermittent versus continuous renal replacement therapy for acute kidney injury patients admitted to the intensive care unit: results of a randomized clinical trial.

    Science.gov (United States)

    Lins, Robert L; Elseviers, Monique M; Van der Niepen, Patricia; Hoste, Eric; Malbrain, Manu L; Damas, Pierre; Devriendt, Jacques

    2009-02-01

    There is uncertainty on the effect of different dialysis modalities for the treatment of patients with acute kidney injury (AKI), admitted to the intensive care unit (ICU). This controlled clinical trial performed in the framework of the multicentre SHARF 4 study (Stuivenberg Hospital Acute Renal Failure) aimed to investigate the outcome in patients with AKI, stratified according to severity of disease and randomized to different treatment options. This was a multicentre prospective randomized controlled trial with stratification according to severity of disease expressed by the SHARF score. ICU patients were eligible for inclusion when serum creatinine was >2 mg/dL, and RRT was initiated. The selected patients were randomized to intermittent (IRRT) or continuous renal replacement therapy (CRRT). A total of 316 AKI patients were randomly assigned to IRRT (n = 144) or CRRT (n = 172). The mean age was 66 (range 18-96); 59% were male. Intention-to-treat analysis revealed a mortality of 62.5% in IRRT compared to 58.1% in CRRT (P = 0.430). No difference between IRRT and CRRT could be observed in the duration of ICU stay or hospital stay. In survivors, renal recovery at hospital discharge was comparable between both groups. Multivariate analysis, including the SHARF score, APACHE II and SOFA scores for correction of disease severity, showed no difference in mortality between both treatment modalities. This result was confirmed in pre-specified subgroup analysis (elderly, patients with sepsis, heart failure, ventilation) and after exclusion of possible confounders (early mortality, delayed ICU admission). Modality of RRT, either CRRT or IRRT, had no impact on the outcome in ICU patients with AKI. Both modalities need to be considered as complementary in the treatment of AKI (Clinical Trial: SHARF 4, NCT00322933, http://ClinicalTrials.gov).

  19. Safety, adherence and acceptability of intermittent tenofovir/emtricitabine as HIV pre-exposure prophylaxis (PrEP among HIV-uninfected Ugandan volunteers living in HIV-serodiscordant relationships: a randomized, clinical trial.

    Directory of Open Access Journals (Sweden)

    Freddie M Kibengo

    Full Text Available BACKGROUND: Efficacy of oral pre-exposure prophylaxis (PrEP in prevention of HIV acquisition has been evaluated using a daily regimen. However, adherence to long term daily medication is rarely perfect. Intermittent regimen may be a feasible alternative. Preclinical studies have demonstrated effectiveness of intermittent PrEP in SHIV prevention among animals. However, little is known about intermittent PrEP regimens. DESIGN: Seventy two HIV-uninfected volunteers in HIV serodiscordant couple relationships in Uganda were randomly assigned to receive daily oral Tenofovir/Emtricitabine (TDF/FTC-Truvada or placebo, or intermittent (Monday, Friday and within 2 hours after sex, not to exceed one dose per day oral TDF/FTC or placebo in a 2:1:2:1 ratio. Volunteers and study staff were blinded to drug assignment, but not to regimen assignment. METHODS: Volunteers were followed for 4 months after randomization, with monthly clinical and laboratory safety assessments and comprehensive HIV risk reduction services. Adherence was monitored using medication event monitoring system (MEMS and self-report. Sexual activity data were collected via daily short text message (SMS and self-report. HIV-specific immune responses were assessed by IFN-γ ELISPOT. RESULTS: Both daily and intermittent oral TDF/FTC regimens were well tolerated. Median MEMS adherence rates were 98% (IQR: 93-100 for daily PrEP regimen, 91% (IQR: 73-97 for fixed intermittent dosing and 45% (IQR: 20-63 for post-coital dosing. SMS response rate was 74%, but increased to 80% after excluding server outages; results may have been affected by the novelty of this measure. The majority of volunteers expressed willingness with no particular preference for either regimen. CONCLUSIONS: Both daily and intermittent oral PrEP dosing regimens were safe. Adherence was high for daily and fixed intermittent dosing; post-coital dosing was associated with poor adherence. Fixed intermittent PrEP regimens may be

  20. Impact of combining intermittent preventive treatment with home management of malaria in children less than 10 years in a rural area of Senegal: a cluster randomized trial

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    Tine Roger CK

    2011-12-01

    Full Text Available Abstract Background Current malaria control strategies recommend (i early case detection using rapid diagnostic tests (RDT and treatment with artemisinin combination therapy (ACT, (ii pre-referral rectal artesunate, (iii intermittent preventive treatment and (iv impregnated bed nets. However, these individual malaria control interventions provide only partial protection in most epidemiological situations. Therefore, there is a need to investigate the potential benefits of integrating several malaria interventions to reduce malaria prevalence and morbidity. Methods A randomized controlled trial was carried out to assess the impact of combining seasonal intermittent preventive treatment in children (IPTc with home-based management of malaria (HMM by community health workers (CHWs in Senegal. Eight CHWs in eight villages covered by the Bonconto health post, (South Eastern part of Senegal were trained to diagnose malaria using RDT, provide prompt treatment with artemether-lumefantrine for uncomplicated malaria cases and pre-referral rectal artesunate for complicated malaria occurring in children under 10 years. Four CHWs were randomized to also administer monthly IPTc as single dose of sulphadoxine-pyrimethamine (SP plus three doses of amodiaquine (AQ in the malaria transmission season, October and November 2010. Primary end point was incidence of single episode of malaria attacks over 8 weeks of follow up. Secondary end points included prevalence of malaria parasitaemia, and prevalence of anaemia at the end of the transmission season. Primary analysis was by intention to treat. The study protocol was approved by the Senegalese National Ethical Committee (approval 0027/MSP/DS/CNRS, 18/03/2010. Results A total of 1,000 children were enrolled. The incidence of malaria episodes was 7.1/100 child months at risk [95% CI (3.7-13.7] in communities with IPTc + HMM compared to 35.6/100 child months at risk [95% CI (26.7-47.4] in communities with only HMM (a

  1. Effectiveness of two programs of intermittent ferrous supplementation for treating iron-deficiency anemia in infants: randomized clinical trial

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    Geraldo Gaspar Paes Leme Coutinho

    Full Text Available CONTEXT AND OBJECTIVE: Low compliance among mothers regarding the treatment of anemic children using daily doses of ferrous sulfate administered at home has been reported. This study aimed to establish the effectiveness of weekly doses administered by mothers at home compared with weekly supplements administered directly by healthcare professionals, to reduce the prevalence of anemia. DESIGN AND SETTING: This was a randomized clinical trial at a public healthcare clinic in São José do Rio Preto, Brazil. METHODS: This iron supplementation study was carried out using two intervention groups. The sample population was 130 infants, randomly allocated to two groups of 65 children. All of them received 12 weekly doses of 25 mg of elemental iron, administered either in the public healthcare clinic or at their homes. RESULTS: Treatment compliance was shown in both groups. The prevalence of anemia among all of the children was 75% at the beginning of supplementation and 46.3% at the end of the period (P < 0.0005, corresponding to a reduction in the number of anemic children of 38.3%. The average increases in hemoglobin concentration levels were 0.75 g/dl and 0.65 g/dl, respectively for home interventions and healthcare clinic administration (P < 0.00005. CONCLUSION: Weekly supplementation of 25 mg of iron was proven to be efficient in reducing anemia, using interventions both at home and in healthcare clinics. Compliance among the mothers was achieved because weekly supplementation was easy to administer and had few side effects. The results showed that the treatment presented low cost and fast benefits.

  2. Cluster-randomized study of intermittent preventive treatment for malaria in infants (IPTi in southern Tanzania: evaluation of impact on survival

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    Schellenberg Joanna

    2011-12-01

    Full Text Available Abstract Background Intermittent Preventive Treatment for malaria control in infants (IPTi consists of the administration of a treatment dose of an anti-malarial drug, usually sulphadoxine-pyrimethamine, at scheduled intervals, regardless of the presence of Plasmodium falciparum infection. A pooled analysis of individually randomized trials reported that IPTi reduced clinical episodes by 30%. This study evaluated the effect of IPTi on child survival in the context of a five-district implementation project in southern Tanzania. [Trial registration: clinical trials.gov NCT00152204]. Methods After baseline household and health facility surveys in 2004, five districts comprising 24 divisions were randomly assigned either to receive IPTi (n = 12 or not (n = 12. Implementation started in March 2005, led by routine health services with support from the research team. In 2007, a large household survey was undertaken to assess the impact of IPTi on survival in infants aged two-11 months through birth history interviews with all women aged 13-49 years. The analysis is based on an "intention-to-treat" ecological design, with survival outcomes analysed according to the cluster in which the mothers lived. Results Survival in infants aged two-11 months was comparable in IPTi and comparison areas at baseline. In intervention areas in 2007, 48% of children aged 12-23 months had documented evidence of receiving three doses of IPTi, compared to 2% in comparison areas (P P = 0.31. Conclusion The lack of evidence of an effect of IPTi on survival could be a false negative result due to a lack of power or imbalance of unmeasured confounders. Alternatively, there could be no mortality impact of IPTi due to low coverage, late administration, drug resistance, decreased malaria transmission or improvements in vector control and case management. This study raises important questions for programme evaluation design.

  3. A modelling breakthrough for market design analysis to test massive intermittent generation integration in markets results of selected OPTIMATE studies

    DEFF Research Database (Denmark)

    Beaude, Francois; Atayi, A.; Bourmaud, J.-Y.

    2013-01-01

    The OPTIMATE1 platform focuses on electricity system and market designs modelling in order to assess current and innovative designs in Europe. The current paper describes the results of the first validation studies' conducted with the tool. These studies deal with day-ahead market rules, load fle...

  4. Sub-optimal delivery of intermittent preventive treatment for malaria in pregnancy in Nigeria: influence of provider factors

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    Onoka Chima A

    2012-09-01

    Full Text Available Abstract Background The level of access to intermittent preventive treatment for malaria in pregnancy (IPTp in Nigeria is still low despite relatively high antenatal care coverage in the study area. This paper presents information on provider factors that affect the delivery of IPTp in Nigeria. Methods Data were collected from heads of maternal health units of 28 public and six private health facilities offering antenatal care (ANC services in two districts in Enugu State, south-east Nigeria. Provider knowledge of guidelines for IPTp was assessed with regard to four components: the drug used for IPTp, time of first dose administration, of second dose administration, and the strategy for sulphadoxine-pyrimethamine (SP administration (directly observed treatment, DOT. Provider practices regarding IPTp and facility-related factors that may explain observations such as availability of SP and water were also examined. Results Only five (14.7% of all 34 providers had correct knowledge of all four recommendations for provision of IPTp. None of them was a private provider. DOT strategy was practiced in only one and six private and public providers respectively. Overall, 22 providers supplied women with SP in the facility and women were allowed to take it at home. The most common reason for doing so amongst public providers was that women were required to come for antenatal care on empty stomachs to enhance the validity of manual fundal height estimation. Two private providers did not think it was necessary to use the DOT strategy because they assumed that women would take their drugs at home. Availability of SP and water in the facility, and concerns about side effects were not considered impediments to delivery of IPTp. Conclusion There was low level of knowledge of the guidelines for implementation of IPTp by all providers, especially those in the private sector. This had negative effects such as non-practice of DOT strategy by most of the providers

  5. The Optimization of Solutions of the Dynamic Systems with Random Structure

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    Miroslava Růžičková

    2011-01-01

    Full Text Available The paper deals with the class of jump control systems with semi-Markov coefficients. The control system is described as the system of linear differential equations. Every jump of the random process implies the random transformation of solutions of the considered system. Relations determining the optimal control to minimize the functional are derived using Lyapunov functions. Necessary conditions of optimization which enables the synthesis of the optimal control are established as well.

  6. Effect of intermittent hepatic inflow occlusion with the Pringle maneuver during donor hepatectomy in adult living donor liver transplantation with right hemiliver grafts: a prospective, randomized controlled study.

    Science.gov (United States)

    Park, Jae Berm; Joh, Jae-Won; Kim, Sung-Joo; Kwon, Choon-Hyuck David; Chun, Jae Min; Kim, Jong Man; Moon, Ju Ik; Lee, Suk-Koo

    2012-01-01

    To evaluate the effects of intermittent hepatic inflow occlusion (IHIO) during donor hepatectomy for living donor liver transplantation (LDLT) in recipients and donors, we performed a single-center, open-label, prospective, parallel, randomized controlled study. Adult donor-recipient pairs undergoing LDLT with right hemiliver grafts were randomized into IHIO and control groups (1:1). In the IHIO group, IHIO was performed during donor hepatectomy. The primary endpoint was the peak serum alanine aminotransferase (ALT) concentration in the recipients within 5 days after the operation. Blood samples for measurements of interleukin-6 (IL-6), IL-8, tumor necrosis factor α (TNF-α), and hepatocyte growth factor (HGF) were taken from the donors and the recipients during the operation and postoperatively. Biopsy samples for measurements of caspase-3 and malondialdehyde (MDA) were taken from the donors and the recipients. In all, 50 donor-recipient pairs (ie, 25 pairs in each group) completed this study. The mean peak serum ALT levels within 5 days after the operation did not differ in the recipients between the 2 groups (P = 0.32) but were higher in the donors of the IHIO group (P = 0.002). There were no differences in the prothrombin times or total bilirubin levels in the recipients or donors between the 2 groups. The amount of blood loss during donor hepatectomy was significantly lower in the IHIO group versus the control group (P = 0.02). The mean hospital stay for donors was 19.3 ± 7.2 days in the control group and 15.8 ± 4.6 days in the IHIO group (P = 0.046). There were no in-hospital deaths within 1 month and no cases of primary nonfunction or initially poor function in the 2 groups. The concentrations of IL-6, IL-8, TNF-α, and HGF did not differ between the 2 groups, nor did the concentrations of caspase-3 and MDA. In conclusion, although we found differences in postoperative peak serum ALT levels in donors, donor hepatectomy with IHIO for LDLT using a right

  7. Initial Treatment of Respiratory Distress Syndrome with Nasal Intermittent Mandatory Ventilation versus Nasal Continuous Positive Airway Pressure: A Randomized Controlled Trial

    Science.gov (United States)

    Armanian, Amir-Mohammad; Badiee, Zohreh; Heidari, Ghobad; Feizi, Awat; Salehimehr, Nima

    2014-01-01

    Background: Neonatal respiratory distress syndrome (RDS) in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV) nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW) preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV) compared with early nasal continuous positive airway pressure (early NCPAP) obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks) with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group). The Preventive power of MV of NIMV usage (95.5%) was not lower than the NCPAP (98.1%) strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66); P: 0.23). The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range) was 24 (18.00-48.00) h versus 48.00 (22.00-120.00) h in NIMV versus NCPAP groups; P < 0.001). Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range) was 96.00 (41.00-504.00) h versus144.00 (70.00-1130.00) h in NIMV versus NCPAP groups; P: 0.009). Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  8. Initial treatment of respiratory distress syndrome with nasal intermittent mandatory ventilation versus nasal continuous positive airway pressure: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2014-01-01

    Full Text Available Background: Neonatal respiratory distress syndrome (RDS in premature infants who survived and its complications are a common problem. Due to high morbidity and mechanical ventilation (MV nowadays researchers in interested minimizing MV. To determine, in very low birth weight (BW preterm neonates with RDS, if initial treatment with nasal intermittent mandatory ventilation (early NIMV compared with early nasal continuous positive airway pressure (early NCPAP obtains more favorable outcomes in terms of the duration of treatment, and the need for endotracheal tube ventilation. Methods: In this single-center randomized control trial study, infants (BW ≤ 1500 g and/or gestational age ≤ 34 weeks with respiratory distress were considered eligible. Forty-four infants were randomly assigned to receive early-NIMV and 54 comparable infants to early-NCPAP. Surfactants were given, when FIO 2 requirement was of >30%. Primary outcomes were failure of noninvasive respiratory support, that is, the need for MV in the first 48 h of life and for the duration of noninvasive respiratory support in each group. Results: 98 infants were enrolled (44 in the NIMV and 54 in the NCPAP group. The Preventive power of MV of NIMV usage (95.5% was not lower than the NCPAP (98.1% strength (hazard ratio: 0.21 (95% confidence interval: 0.02-2.66; P: 0.23. The duration of noninvasive respiratory support in the NIMV group was significantly shorter than NCPAP (the median (range was 24 (18.00-48.00 h versus 48.00 (22.00-120.00 h in NIMV versus NCPAP groups; P < 0.001. Similarly, the duration of dependency on oxygen was less, for NIMV (the median (range was 96.00 (41.00-504.00 h versus144.00 (70.00-1130.00 h in NIMV versus NCPAP groups; P: 0.009. Interestingly, time to full enteral feeds and length of hospital stay were more favorable in the NIMV versus the NCPAP group. Conclusions: Initial treatment of RDS with NIMV was safe, and well tolerated. Furthermore, NIMV had excellent

  9. Intermittent preventive treatment for malaria in Papua New Guinean infants exposed to Plasmodium falciparum and P. vivax: a randomized controlled trial.

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    Nicolas Senn

    Full Text Available BACKGROUND: Intermittent preventive treatment in infants (IPTi has been shown in randomized trials to reduce malaria-related morbidity in African infants living in areas of high Plasmodium falciparum (Pf transmission. It remains unclear whether IPTi is an appropriate prevention strategy in non-African settings or those co-endemic for P. vivax (Pv. METHODS AND FINDINGS: In this study, 1,121 Papua New Guinean infants were enrolled into a three-arm placebo-controlled randomized trial and assigned to sulfadoxine-pyrimethamine (SP (25 mg/kg and 1.25 mg/kg plus amodiaquine (AQ (10 mg/kg, 3 d, n = 374, SP plus artesunate (AS (4 mg/kg, 3 d, n = 374, or placebo (n = 373, given at 3, 6, 9 and 12 mo. Both participants and study teams were blinded to treatment allocation. The primary end point was protective efficacy (PE against all episodes of clinical malaria from 3 to 15 mo of age. Analysis was by modified intention to treat. The PE (compared to placebo against clinical malaria episodes (caused by all species was 29% (95% CI, 10-43, p ≤ 0.001 in children receiving SP-AQ and 12% (95% CI, -11 to 30, p = 0.12 in those receiving SP-AS. Efficacy was higher against Pf than Pv. In the SP-AQ group, Pf incidence was 35% (95% CI, 9-54, p = 0.012 and Pv incidence was 23% (95% CI, 0-41, p = 0.048 lower than in the placebo group. IPTi with SP-AS protected only against Pf episodes (PE = 31%, 95% CI, 4-51, p = 0.027, not against Pv episodes (PE = 6%, 95% CI, -24 to 26, p = 0.759. Number of observed adverse events/serious adverse events did not differ between treatment arms (p > 0.55. None of the serious adverse events were thought to be treatment-related, and the vomiting rate was low in both treatment groups (1.4%-2.0%. No rebound in malaria morbidity was observed for 6 mo following the intervention. CONCLUSIONS: IPTi using a long half-life drug combination is efficacious for the prevention of malaria and anemia in infants

  10. Optimization, Randomized Approximability, and Boolean Constraint Satisfaction Problems

    CERN Document Server

    Yamakami, Tomoyuki

    2011-01-01

    We give a unified treatment to optimization problems that can be expressed in the form of nonnegative-real-weighted Boolean constraint satisfaction problems. Creignou, Khanna, Sudan, Trevisan, and Williamson studied the complexity of approximating their optimal solutions whose optimality is measured by the sums of outcomes of constraints. To explore a wider range of optimization constraint satisfaction problems, following an early work of Marchetti-Spaccamela and Romano, we study the case where the optimality is measured by products of constraints' outcomes. We completely classify those problems into three categories: PO problems, NPO-hard problems, and intermediate problems that lie between the former two categories. To prove this trichotomy theorem, we analyze characteristics of nonnegative-real-weighted constraints using a variant of the notion of T-constructibility developed earlier for complex-weighted counting constraint satisfaction problems.

  11. Intermittent Chemotherapy as a Platform for Testing Novel Agents in Patients With Metastatic Castration-Resistant Prostate Cancer: A Department of Defense Prostate Cancer Clinical Trials Consortium Randomized Phase II Trial of Intermittent Docetaxel With Prednisone With or Without Maintenance GM-CSF.

    Science.gov (United States)

    Aggarwal, Rahul R; Beer, Tomasz M; Weinberg, Vivian K; Higano, Celestia; Taplin, Mary-Ellen; Ryan, Charles J; Lin, Amy M; Alumkal, Joshi; Graff, Julie N; Nordquist, Luke T; Herrera, Isheen; Small, Eric J

    2015-06-01

    Immunotherapy with granulocyte-macrophage colony-stimulating factor (GM-CSF), an agent that previously demonstrated antitumor activity, was evaluated within an intermittent chemotherapy framework of docetaxel with prednisone (D+P) in metastatic castration-resistant prostate cancer (mCRPC). mCRPC patients with ≥ 50% prostate-specific antigen (PSA) decline after 6 cycles of D+P were randomized to either GM-CSF or observation (Obs). At disease progression (PD), D+P was reinitiated for 6 cycles followed by the same "off chemotherapy" regimen in patients eligible for chemotherapy interruption. The sequence was repeated until PD during chemotherapy, lack of PSA response to chemotherapy, or unacceptable toxicity. The primary end point was time to chemotherapy resistance (TTCR). Of 125 patients enrolled, 52 (42%) experienced ≥ 50% PSA decline on induction D+P and were randomized to GM-CSF (n = 27) or Obs (n = 25). The median time to PD was 3.3 months (95% confidence interval [CI], 2.4-3.5) and 1.5 months (95% CI, 1.5-2.4) during the initial course of GM-CSF and Obs, respectively. Twelve of 26 (46%) patients responded to a second course of D+P. Eleven randomized patients (21%) experienced PD during chemotherapy, precluding accurate assessment of TTCR. The remaining 41 randomized patients discontinued study for lack of PSA response to chemotherapy (n = 8), patient choice to not restart chemotherapy with PSA PD (n = 13), toxicity (n = 7), or study withdrawal (n = 13). Conducting a prospective study in mCRPC with maintenance immunotherapy within the framework of intermittent chemotherapy was feasible. The use of PSA instead of radiographic end points limited the number of evaluable patients. This study provides important insight into designing contemporary intermittent chemotherapy trials with maintenance immunotherapy in patients with advanced prostate cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Optimal randomized EREW PRAM algorithms for finding spanning forests and for other basic graph connectivity problems

    Energy Technology Data Exchange (ETDEWEB)

    Halperin, S.; Zwick, U. [Tel Aviv Univ. (Israel)

    1996-12-31

    We present the first randomized O(log n) time and O(m + n) work EREW PRAM algorithm for finding a spanning forest of an undirected graph G = (V, E) with n vertices and m edges. Our algorithm is optimal with respect to time, work and space. As a consequence we get optimal randomized EREW PRAM algorithms for other basic connectivity problems such as finding a bipartite partition, finding bridges and biconnected components, and finding Euler tours in Eulerean graphs. For other problems such as finding an ear decomposition, finding an open ear decomposition, finding a strong orientation, and finding an st-numbering we get optimal randomized CREW PRAM algorithms.

  13. Bayesian Optimization in High Dimensions via Random Embeddings

    NARCIS (Netherlands)

    Wang, Z.; Zoghi, M.; Hutter, F.; Matheson, D.; de Freitas, N.; Rossi, F.

    2013-01-01

    Bayesian optimization techniques have been successfully applied to robotics, planning, sensor placement, recommendation, advertising, intelligent user interfaces and automatic algorithm configuration. Despite these successes, the approach is restricted to problems of moderate dimension, and several

  14. Moments of random sums and Robbins' problem of optimal stopping

    CERN Document Server

    Gnedin, Alexander

    2011-01-01

    Robbins' problem of optimal stopping asks one to minimise the expected {\\it rank} of observation chosen by some nonanticipating stopping rule. We settle a conjecture regarding the {\\it value} of the stopped variable under the rule optimal in the sense of the rank, by embedding the problem in a much more general context of selection problems with the nonanticipation constraint lifted, and with the payoff growing like a power function of the rank.

  15. Optimal epsilon-biased sets with just a little randomness

    CERN Document Server

    Moore, Cristopher

    2012-01-01

    Subsets of F_2^n that are eps-biased, meaning that the parity of any set of bits is even or odd with probability eps close to 1/2, are useful tools in derandomization. A simple randomized construction shows that such sets exist of size O(n/eps^2), and known deterministic constructions achieve sets of size O(n/eps^3), O(n^2/eps^2), and O((n/eps^2)^{5/4}). Rather than derandomizing these sets completely in exchange for making them larger, we attempt a partial derandomization while keeping them small, constructing sets of size O(n/eps^2) with as few random bits as possible. The naive randomized construction requires O(n^2/eps^2) random bits. We show that this can be reduced to O(n log (n/eps)) random bits. Our construction uses the Legendre symbol and Weil sums, but in a different way than the construction of Alon, Goldreich, Haastad, and Peralta.

  16. Randomized BioBrick assembly: a novel DNA assembly method for randomizing and optimizing genetic circuits and metabolic pathways.

    Science.gov (United States)

    Sleight, Sean C; Sauro, Herbert M

    2013-09-20

    The optimization of genetic circuits and metabolic pathways often involves constructing various iterations of the same construct or using directed evolution to achieve the desired function. Alternatively, a method that randomizes individual parts in the same assembly reaction could be used for optimization by allowing for the ability to screen large numbers of individual clones expressing randomized circuits or pathways for optimal function. Here we describe a new assembly method to randomize genetic circuits and metabolic pathways from modular DNA fragments derived from PCR-amplified BioBricks. As a proof-of-principle for this method, we successfully assembled CMY (Cyan-Magenta-Yellow) three-gene circuits using Gibson Assembly that express CFP, RFP, and YFP with independently randomized promoters, ribosome binding sites, transcriptional terminators, and all parts randomized simultaneously. Sequencing results from 24 CMY circuits with various parts randomized show that 20/24 circuits are distinct and expression varies over a 200-fold range above background levels. We then adapted this method to randomize the same parts with enzyme coding sequences from the lycopene biosynthesis pathway instead of fluorescent proteins, designed to independently express each enzyme in the pathway from a different promoter. Lycopene production is improved using this randomization method by about 30% relative to the highest polycistronic-expressing pathway. These results demonstrate the potential of generating nearly 20,000 unique circuit or pathway combinations when three parts are permutated at each position in a three-gene circuit or pathway, and the methodology can likely be adapted to other circuits and pathways to maximize products of interest.

  17. Memoryless Routing in Convex Subdivisions: Random Walks are Optimal

    CERN Document Server

    Chen, Dan; Dujmovic, Vida; Morin, Pat

    2009-01-01

    A memoryless routing algorithm is one in which the decision about the next edge on the route to a vertex t for a packet currently located at vertex v is made based only on the coordinates of v, t, and the neighbourhood, N(v), of v. The current paper explores the limitations of such algorithms by showing that, for any (randomized) memoryless routing algorithm A, there exists a convex subdivision on which A takes Omega(n^2) expected time to route a message between some pair of vertices. Since this lower bound is matched by a random walk, this result implies that the geometric information available in convex subdivisions is not helpful for this class of routing algorithms. The current paper also shows the existence of triangulations for which the Random-Compass algorithm proposed by Bose etal (2002,2004) requires 2^{\\Omega(n)} time to route between some pair of vertices.

  18. Intermittent preventive treatment of malaria in pregnancy with mefloquine in HIV-infected women receiving cotrimoxazole prophylaxis: a multicenter randomized placebo-controlled trial.

    Directory of Open Access Journals (Sweden)

    Raquel González

    2014-09-01

    Full Text Available BACKGROUND: Intermittent preventive treatment in pregnancy (IPTp with sulfadoxine-pyrimethamine (SP is recommended for malaria prevention in HIV-negative pregnant women, but it is contraindicated in HIV-infected women taking daily cotrimoxazole prophylaxis (CTXp because of potential added risk of adverse effects associated with taking two antifolate drugs simultaneously. We studied the safety and efficacy of mefloquine (MQ in women receiving CTXp and long-lasting insecticide treated nets (LLITNs. METHODS AND FINDINGS: A total of 1,071 HIV-infected women from Kenya, Mozambique, and Tanzania were randomized to receive either three doses of IPTp-MQ (15 mg/kg or placebo given at least one month apart; all received CTXp and a LLITN. IPTp-MQ was associated with reduced rates of maternal parasitemia (risk ratio [RR], 0.47 [95% CI 0.27-0.82]; p=0.008, placental malaria (RR, 0.52 [95% CI 0.29-0.90]; p=0.021, and reduced incidence of non-obstetric hospital admissions (RR, 0.59 [95% CI 0.37-0.95]; p=0.031 in the intention to treat (ITT analysis. There were no differences in the prevalence of adverse pregnancy outcomes between groups. Drug tolerability was poorer in the MQ group compared to the control group (29.6% referred dizziness and 23.9% vomiting after the first IPTp-MQ administration. HIV viral load at delivery was higher in the MQ group compared to the control group (p=0.048 in the ATP analysis. The frequency of perinatal mother to child transmission of HIV was increased in women who received MQ (RR, 1.95 [95% CI 1.14-3.33]; p=0.015. The main limitation of the latter finding relates to the exploratory nature of this part of the analysis. CONCLUSIONS: An effective antimalarial added to CTXp and LLITNs in HIV-infected pregnant women can improve malaria prevention, as well as maternal health through reduction in hospital admissions. However, MQ was not well tolerated, limiting its potential for IPTp and indicating the need to find alternatives with

  19. Random matrix theory for portfolio optimization: a stability approach

    Science.gov (United States)

    Sharifi, S.; Crane, M.; Shamaie, A.; Ruskin, H.

    2004-04-01

    We apply random matrix theory (RMT) to an empirically measured financial correlation matrix, C, and show that this matrix contains a large amount of noise. In order to determine the sensitivity of the spectral properties of a random matrix to noise, we simulate a set of data and add different volumes of random noise. Having ascertained that the eigenspectrum is independent of the standard deviation of added noise, we use RMT to determine the noise percentage in a correlation matrix based on real data from S&P500. Eigenvalue and eigenvector analyses are applied and the experimental results for each of them are presented to identify qualitatively and quantitatively different spectral properties of the empirical correlation matrix to a random counterpart. Finally, we attempt to separate the noisy part from the non-noisy part of C. We apply an existing technique to cleaning C and then discuss its associated problems. We propose a technique of filtering C that has many advantages, from the stability point of view, over the existing method of cleaning.

  20. Moments of random sums and Robbins' problem of optimal stopping

    NARCIS (Netherlands)

    Gnedin, A.V.; Iksanov, A.

    2011-01-01

    Robbins' problem of optimal stopping is that of minimising the expected rank of an observation chosen by some nonanticipating stopping rule. We settle a conjecture regarding the value of the stopped variable under the rule that yields the minimal expected rank, by embedding the problem in a much

  1. Moments of random sums and Robbins' problem of optimal stopping

    NARCIS (Netherlands)

    Gnedin, A.V.; Iksanov, A.

    2011-01-01

    Robbins' problem of optimal stopping is that of minimising the expected rank of an observation chosen by some nonanticipating stopping rule. We settle a conjecture regarding the value of the stopped variable under the rule that yields the minimal expected rank, by embedding the problem in a much mor

  2. In a Randomized Controlled Trial of Iron Fortification, Anthelmintic Treatment, and Intermittent Preventive Treatment of Malaria for Anemia Control in Ivorian Children, only Anthelmintic Treatment Shows Modest Benefit

    NARCIS (Netherlands)

    Rohner, F.; Zimmermann, M.B.; Amon, R.J.; Vounatsou, P.; Tschannen, A.B.; N'goran, E.K.; Nindjin, C.; Cacou, M.C.; Té-Bonlé, D.; Aka, H.; Sess, D.E.; Utzinger, J.; Hurrell, R.F.

    2010-01-01

    Anemia is common among children in sub-Saharan Africa and its etiology is multifactorial. Likely causes of anemia are low bioavailability of dietary iron, malaria, and helminth infection. In this study, we aimed to assess the effect of iron fortification, intermittent preventive treatment (IPT) of m

  3. Stochastic Optimal Estimation with Fuzzy Random Variables and Fuzzy Kalman Filtering

    Institute of Scientific and Technical Information of China (English)

    FENG Yu-hu

    2005-01-01

    By constructing a mean-square performance index in the case of fuzzy random variable, the optimal estimation theorem for unknown fuzzy state using the fuzzy observation data are given. The state and output of linear discrete-time dynamic fuzzy system with Gaussian noise are Gaussian fuzzy random variable sequences. An approach to fuzzy Kalman filtering is discussed. Fuzzy Kalman filtering contains two parts: a real-valued non-random recurrence equation and the standard Kalman filtering.

  4. Quasiparticle Random Phase Approximation with an optimal Ground State

    CERN Document Server

    Simkovic, F; Raduta, A A

    2001-01-01

    A new Quasiparticle Random Phase Approximation approach is presented. The corresponding ground state is variationally determined and exhibits a minimum energy. New solutions for the ground state, some with spontaneously broken symmetry, of a solvable Hamiltonian are found. A non-iterative procedure to solve the non-linear QRPA equations is used and thus all possible solutions are found. These are compared with the exact results as well as with the solutions provided by other approaches.

  5. Does continuous endurance exercise in water elicit a higher release of ANP and BNP and a higher plasma concentration of FFAs in pre-obese and obese men than high intensity intermittent endurance exercise? - study protocol for a randomized controlled trial.

    Science.gov (United States)

    Karner-Rezek, Klaus; Knechtle, Beat; Fenzl, Matthias; Gredig, Joeri; Rosemann, Thomas

    2013-10-10

    Atrial natriuretic peptides (ANP) and Brain natriuretic peptides (BNP) stimulate fat cell plasma membrane receptors. They are potent lipolytic agents on isolated fat cells from subcutaneous adipose tissue. The physiological effects of continuous endurance exercise on ANP release and plasma free fatty acids (FFA) concentrations have been well described. The enhancement of fat metabolism using high intensity intermittent exercise protocols has been assessed in more recent investigations. The combined effects of endurance exercise and water immersion on ANP and FFA plasma concentration and the magnitude of excess post-exercise oxygen consumption (EPOC) might be further enhanced by choosing the most effective exercise protocol. Exercise modalities may play a significant role in the future prevention and treatment of obesity. The two testing trials will be performed according to a randomized and cross-over design. Twenty healthy sedentary pre-obese and obese class-1 men will be scrutinized with regard to their metabolic responses to continuous exercise in water and to high intensity endurance exercise in water. Both trials will be matched for energy expenditure. After preliminary testing, the tests will be conducted as repeated measurements. The two different exercise protocols will be compared. The aims of the study are to investigate (1) whether continuous endurance exercise or high intensity intermittent endurance exercise in water elicits both a higher release of ANP and BNP and a higher plasma concentration of glycerol and (2) to determine whether continuous endurance exercise in water or a high intensity intermittent endurance exercise in water would lead to a more pronounced short term (two hours) EPOC effect. If our hypothesis would be confirmed, the most effective exercise protocol based on the combined effects of high intensity endurance exercise and water immersion on ANP and BNP release and glycerol plasma concentrations can be identified. Moreover, the

  6. Optimal evolution on random networks: from social to airports networks

    CERN Document Server

    Curty, P

    2005-01-01

    Social movements, neurons in the brain or even industrial suppliers are best described by agents evolving on networks with basic interaction rules. In these real systems, the connectivity between agents corresponds to the most efficient state of the system. The new idea is that connectivity adjusts itself because of two opposite tendencies: information percolation, decision making or coordination are better when the network connectivity is small. When agents have many connections, the opinion of a person or the state of a neuron tend to freeze: agents find always a minority among their advisors to support their opinion. A general and new model reproduces these features showing a clear transition between the two tendencies at some critical connectivity. Depending on the noise, the evolution of the system is optimal at a precise critical connectivity since, away from this critical point, the system always ends up in a static phase. When the error tolerance is very small, the optimal connectivity becomes very la...

  7. Local Law of Addition of Random Matrices on Optimal Scale

    Science.gov (United States)

    Bao, Zhigang; Erdős, László; Schnelli, Kevin

    2016-11-01

    The eigenvalue distribution of the sum of two large Hermitian matrices, when one of them is conjugated by a Haar distributed unitary matrix, is asymptotically given by the free convolution of their spectral distributions. We prove that this convergence also holds locally in the bulk of the spectrum, down to the optimal scales larger than the eigenvalue spacing. The corresponding eigenvectors are fully delocalized. Similar results hold for the sum of two real symmetric matrices, when one is conjugated by Haar orthogonal matrix.

  8. Random matrix theory and portfolio optimization in Moroccan stock exchange

    Science.gov (United States)

    El Alaoui, Marwane

    2015-09-01

    In this work, we use random matrix theory to analyze eigenvalues and see if there is a presence of pertinent information by using Marčenko-Pastur distribution. Thus, we study cross-correlation among stocks of Casablanca Stock Exchange. Moreover, we clean correlation matrix from noisy elements to see if the gap between predicted risk and realized risk would be reduced. We also analyze eigenvectors components distributions and their degree of deviations by computing the inverse participation ratio. This analysis is a way to understand the correlation structure among stocks of Casablanca Stock Exchange portfolio.

  9. Optimal resource allocation in random networks with transportation bandwidths

    Science.gov (United States)

    Yeung, C. H.; Wong, K. Y. Michael

    2009-03-01

    We apply statistical physics to study the task of resource allocation in random sparse networks with limited bandwidths for the transportation of resources along the links. Recursive relations from the Bethe approximation are converted into useful algorithms. Bottlenecks emerge when the bandwidths are small, causing an increase in the fraction of idle links. For a given total bandwidth per node, the efficiency of allocation increases with the network connectivity. In the high connectivity limit, we find a phase transition at a critical bandwidth, above which clusters of balanced nodes appear, characterized by a profile of homogenized resource allocation similar to the Maxwell construction.

  10. 热泵间歇干燥最优方式研究%Researches on the OPtimal Process of Heat PumP Intermittent Drying

    Institute of Scientific and Technical Information of China (English)

    赵海波; 杨昭; 朱宗升

    2014-01-01

    热泵间歇干燥是一种能耗低﹑干燥产品质量高的新型干燥方式,深入开展其工艺优化研究非常必要。以白菜种子热泵干燥为例,建立由干燥空气传热与传质模型﹑种子传热与传质模型组成的干燥模型,根据模拟结果确定了描述热泵间歇干燥性能的机组性能指标和干燥产品性能指标,运用模糊层次分析法获得热泵机组性能和干燥产品性能综合最优的热泵间歇干燥方式。结果表明,对白菜种子而言,干燥周期为3000 s﹑比例系数为1∕6的热泵间歇干燥的综合性能最优。%Heat pump intermittent drying(HPID) is an energy_efficient process with high quality products.It is necessary to carry on a further research on its optimal process.A heat pump drying model was built for the cabbage seed with heat pump drying.It included the heat and mass transfer models of the drying air and those of the cabbage seed.The simulation results were used to form the heat pump unit performance index and the dried product performance index.The fuzzy analytical hierarchy process method was used to obtain the optimal HPID process excelling in both the heat pump unit performance index and the dried product performance index.Results show that the HPID with drying period of 3000 s, proportion of 1 ∕6 can obtain the best comprehensive performance for the cabbage seed.

  11. Dialysis complications in acute kidney injury patients treated with prolonged intermittent renal replacement therapy sessions lasting 10 versus 6 hours: results of a randomized clinical trial.

    Science.gov (United States)

    Albino, Bianca Ballarin; Balbi, André Luis; Abrão, Juliana Maria Gera; Ponce, Daniela

    2015-05-01

    Prolonged intermittent renal replacement therapy (PIRRT) has emerged as an alternative to continuous renal replacement therapy in the management of acute kidney injury (AKI) patients. This trial aimed to compare the dialysis complications occurring during different durations of PIRRT sessions in critically ill AKI patients. We included patients older than 18 years with AKI associated with sepsis admitted to the intensive care unit and using noradrenaline doses ranging from 0.3 to 0.7 µg/kg/min. Patients were divided into two groups randomly: in G1, 6-h sessions were performed, and in G2, 10-h sessions were performed. Seventy-five patients were treated with 195 PIRRT sessions for 18 consecutive months. The prevalence of hypotension, filter clotting, hypokalemia, and hypophosphatemia was 82.6, 25.3, 20, and 10.6%, respectively. G1 was composed of 38 patients treated with 100 sessions, whereas G2 consisted of 37 patients treated with 95 sessions. G1 and G2 were similar in male predominance (65.7 vs. 75.6%, P = 0.34), age (63.6 ± 14 vs. 59.9 ± 15.5 years, P = 0.28) and Sequential Organ Failure Assessment score (SOFA; 13.1 ± 2.4 vs. 14.2 ± 3.0, P = 0.2). There was no significant difference between the two groups in hypotension (81.5 vs. 83.7%, P = 0.8), filter clotting (23.6 vs. 27%, P = 0.73), hypokalemia (13.1 vs. 8.1%, P = 0.71), and hypophosphatemia (18.4 vs. 21.6%, P = 0.72). However, the group treated with sessions of 10 h were refractory to clinical measures for hypotension, and dialysis sessions were interrupted more often (9.5 vs. 30.1%, P = 0.03). Metabolic control and fluid balance were similar between G1 and G2 (blood urea nitrogen [BUN]: 81 ± 30 vs. 73 ± 33 mg/dL, P = 1.0; delivered Kt/V: 1.09 ± 0.24 vs. 1.26 ± 0.26, P = 0.09; actual ultrafiltration: 1731 ± 818 vs. 2332 ± 947 mL, P = 0.13) and fluid balance (-731 ± 125 vs. -652 ± 141

  12. Scheduling in a random environment: stability and asymptotic optimality

    CERN Document Server

    Ayesta, U; Jonckheere, M; Verloop, I M

    2011-01-01

    We investigate the scheduling of a common resource between several concurrent users when the feasible transmission rate of each user varies randomly over time. Time is slotted and users arrive and depart upon service completion. This may model for example the flow-level behavior of end-users in a narrowband HDR wireless channel (CDMA 1xEV-DO). As performance criteria we consider the stability of the system and the mean delay experienced by the users. Given the complexity of the problem we investigate the fluid-scaled system, which allows to obtain important results and insights for the original system: (1) We characterize for a large class of scheduling policies the stability conditions and identify a set of maximum stable policies, giving in each time slot preference to users being in their best possible channel condition. We find in particular that many opportunistic scheduling policies like Score-Based, Proportionally Best or Potential Improvement are stable under the maximum stability conditions, whereas ...

  13. Intermittency in Complex Flows

    Science.gov (United States)

    Ben Mahjoub, Otman; Redondo, Jose M.

    2017-04-01

    Experimental results of the complex turbulent wake of a cilinder in 2D [1] and 3D flows [2] were used to investigate the scaling of structure functions, similar research was also performed on wave propagation and breaking in the Ocean [3], in the the stratified Atmosphere (ABL) [4] and in a 100large flume (UPC) for both regular and irregular waves, where long time series of waves propagating and generating breaking turbulence velocity rms and higher order measurements were taken in depth. [3,5] by means of a velocimeter SONTEK3-D. The probability distribution functions of the velocity differences and their non Gaussian distribution related to the energy spectrum indicate that irregularity is an important source of turbulence. From Kolmogorov's K41 and K61 intermittency correction: the p th-order longitudinal velocity structure function δul at scale l in the inertial range of three-dimensional fully developed turbulence is related by ⟨δup⟩ = ⟨(u(x+ l)- u(x))p⟩ ˜ ɛp0/3lp/3 l where ⟨...⟩ represents the spatial average over flow domain, with ɛ0 the mean energy dissipation per unit mass and l is the separation distance. The importance of the random nature of the energy dissipation led to the K62 theory of intermittency, but locality and non-homogeneity are key issues. p p/3 p/3 ξd ⟨δul⟩ ˜ ⟨ɛl ⟩l ˜ l and ξp = p 3 + τp/3 , where now ɛl is a fractal energy dissipation at scale l, τp/3 is the scaling of and ξp is the scaling exponent of the velocity structure function of order p. Both in K41 and K62, the structure functions of third order related to skewness is ξ3 = 1. But this is not true either. We show that scaling exponents ξp do deviate from early studies that only investigated homogeneous turbulence, where a large inertial range dominates. The use of multi-fractal analysis and improvements on Structure function calculations on standard Enhanced mixing is an essential property of turbulence and efforts to alter and to control

  14. Optimal wind farm sitting using high-resolution digital elevation models and randomized optimization

    Directory of Open Access Journals (Sweden)

    John Koutroumpas

    2015-09-01

    Full Text Available We investigate the problem of wind farm design in isolated mountainous areas. We first describe a remote sensing approach for the terrain reconstruction of complex terrains. We then employ a well--known evolutionary optimization algorithm to find the optimal wind farm layout. Although the algorithm has been efficiently used for off--shore or smooth on--shore areas, we show that its performance is significantly affected by the complex topography. Moreover, we illustrate how a priori information can be exploited to improve both the computational time and efficiency of the optimization algorithm.

  15. A Particle Swarm Optimization Algorithm with Variable Random Functions and Mutation

    Institute of Scientific and Technical Information of China (English)

    ZHOU Xiao-Jun; YANG Chun-Hua; GUI Wei-Hua; DONG Tian-Xue

    2014-01-01

    The convergence analysis of the standard particle swarm optimization (PSO) has shown that the changing of random functions, personal best and group best has the potential to improve the performance of the PSO. In this paper, a novel strategy with variable random functions and polynomial mutation is introduced into the PSO, which is called particle swarm optimization algorithm with variable random functions and mutation (PSO-RM). Random functions are adjusted with the density of the population so as to manipulate the weight of cognition part and social part. Mutation is executed on both personal best particle and group best particle to explore new areas. Experiment results have demonstrated the effectiveness of the strategy.

  16. STOCHASTIC OPTIMAL CONTROL OF STRONGLY NONLINEAR SYSTEMS UNDER WIDE-BAND RANDOM EXCITATION WITH ACTUATOR SATURATION

    Institute of Scientific and Technical Information of China (English)

    Changshui Feng; Weiqiu Zhu

    2008-01-01

    A bounded optimal control strategy for strongly non-linear systems under non-white wide-band random excitation with actuator saturation is proposed. First, the stochastic averaging method is introduced for controlled strongly non-linear systems under wide-band random excitation using generalized harmonic functions. Then, the dynamical programming equation for the saturated control problem is formulated from the partially averaged Ito equation based on the dynamical programming principle. The optimal control consisting of the unbounded optimal control and the bounded bang-bang control is determined by solving the dynamical programming equation. Finally, the response of the optimally controlled system is predicted by solving the reduced Fokker-Planck-Kolmogorov (FPK) equation associated with the completed averaged Ito equation. An example is given to illustrate the proposed control strategy. Numerical results show that the proposed control strategy has high control effectiveness and efficiency and the chattering is reduced significantly comparing with the bang-bang control strategy.

  17. Efficacy and Safety of Azithromycin-Chloroquine versus Sulfadoxine-Pyrimethamine for Intermittent Preventive Treatment of Plasmodium falciparum Malaria Infection in Pregnant Women in Africa: An Open-Label, Randomized Trial.

    Directory of Open Access Journals (Sweden)

    Joshua Kimani

    Full Text Available The World Health Organization recommends intermittent preventive treatment in pregnancy (IPTp with sulfadoxine-pyrimethamine (SP in African regions with moderate to high malaria transmission. However, growing resistance to SP threatens the effectiveness of IPTp-SP, and alternative drugs are needed. This study tested the efficacy, tolerability, and safety of a fixed-dose combination azithromycin-chloroquine (AZCQ; 250 mg AZ/155 mg CQ base for IPTp relative to IPTp-SP.A randomized, Phase 3, open-label, multi-center study was conducted in sub-Saharan Africa (Benin, Kenya, Malawi, Tanzania, and Uganda between October 2010 and November 2013. Pregnant women received 3 IPTp courses with AZCQ (each course: 1,000/620 mg AZCQ QD for 3 days or SP (each course 1,500/75 mg SP QD for 1 day at 4- to 8-week intervals during the second and third trimester. Long-lasting insecticide-treated bednets were also provided at enrollment. Study participants were followed up until day 28 post delivery (time window: day 28-42. The primary endpoint was the proportion of participants with sub-optimal pregnancy outcomes (a composite endpoint comprising live-borne neonates with low birth weight [LBW, 28 weeks], abortion [≤28 weeks], lost to follow-up prior to observation of pregnancy outcome, or missing birth weight. The study was terminated early after recruitment of 2,891 of the planned 5,044 participants, due to futility observed in a pre-specified 35% interim analysis. In the final intent-to-treat dataset, 378/1,445 (26.2% participants in the AZCQ and 342/1,445 (23.7% in the SP group had sub-optimal pregnancy outcomes, with an estimated risk ratio (RR of 1.11 (95% CI: 0.97, 1.25; p = 0.12. There was no significant difference in the incidence of LBW between treatment groups (57/1138 [5.0%] in the AZCQ group, 68/1188 [5.7%] in the SP group, RR 0.87 [95% CI: 0.62, 1.23]; p = 0.44. IPTp-AZCQ was less well-tolerated in mothers than IPTp-SP. Occurrences of congenital anomalies

  18. Simultaneous seismic random noise attenuation and signal preservation by optimal spatiotemporal TFPF

    Science.gov (United States)

    Lin, Hongbo; Li, Yue; Ma, Haitao; Xu, Liping

    2016-05-01

    The time-frequency peak filtering (TFPF) algorithm has been successfully applied to seismic random noise attenuation. However, the time-frequency peak filtering with fixed-type spatiotemporal filtering trajectories fails to preserve reflected signals in seismic events which have complex geometric structure. An optimal spatiotemporal TFPF (OST-TFPF) is proposed here combining the Shapiro-Francia (S-F) statistic to reduce random noise and preserve seismic signals simultaneously. In the novel algorithm, the S-F statistic is first calculated for seismic data to detect seismic events based on the fact that the non-Gaussian seismic signals lead to smaller values of the S-F statistic comparing to seismic random noise which is general Gaussian. Then, optimal spatiotemporal filtering trajectory can be constructed based on the S-F statistic to coincide with the shape of each event. Finally, the optimal spatiotemporal TFPF de-noises seismic data along the optimal trajectories. Since the resampled signals along the trajectories matching the geometric structures of seismic events become more linear compared to signals in time, the OST-TFPF gives better signal estimation while attenuating random noise. Synthetic and field data examples demonstrate that the optimal spatiotemporal TFPF is effective in the denoising and signal-preserving of the seismic data with low signal-to-noise ratio. Moreover, the OST-TFPF also obtains good performance in preservation of seismic event with complex geometric structure.

  19. 含间歇性电源的电力系统动态有功优化调度的思路构建%Power System Containing Intermittent Power Supply Construction Dynamic Optimization Scheduling of Active Thinking

    Institute of Scientific and Technical Information of China (English)

    车轮

    2014-01-01

    近年来,随着风电场和光伏电站的大量并网,对电力系统的运行造成了一定影响。在电力系统中,可将风电场和光伏电站等作为间歇性电源。为了实现间歇性电源在电力系统内部的合理消纳,有必要制订合理、可行的调度策略,这样不仅可以提高间歇性电源本身的调节能力,还能提高电力系统运行的安全性和经济性。基于此,就含间歇性电源的电力系统动态有功优化调度思路的构建展开研究。%In recent years, with wind farms and solar power plants and a large network of operation of power systems caused some impact. In the power system can be such as wind farms and solar power plants, as intermittent power supply. In order to achieve intermittent electricity supply at a reasonable consumptive internal system, it is necessary to establish a reasonable and feasible scheduling policy, so not only can improve the intermittent ability to regulate its own power supply, but also improve the operation of the power system security and economy. Based on this, the intermittent power supply systems with active optimization of dynamic scheduling idea to build a study.

  20. Design of piezoelectric energy harvesting devices subjected to broadband random vibrations by applying topology optimization

    Institute of Scientific and Technical Information of China (English)

    Zhe-Qi Lin; Hae Chang Gea; Shu-Tian Liu

    2011-01-01

    Converting ambient vibration energy into electrical energy by using piezoelectric energy harvester has attracted a lot of interest in the past few years.In this paper,a topology optimization based method is applied to simultaneously determine the optimal layout of the piezoelectric energy harvesting devices and the optimal position of the mass loading.The objective function is to maximize the energy harvesting performance over a range of vibration frequencies.Pseudo excitation method (PEM) is adopted to analyze structural stationary random responses,and sensitivity analysis is then performed by using the adjoint method.Numerical examples are presented to demonstrate the validity of the proposed approach.

  1. Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope

    Science.gov (United States)

    Quan, Wei; Lv, Lin; Liu, Baiqi

    2014-11-01

    In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

  2. Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope

    Energy Technology Data Exchange (ETDEWEB)

    Quan, Wei; Lv, Lin, E-mail: lvlinlch1990@163.com; Liu, Baiqi [School of Instrument Science and Opto-Electronics Engineering, Beihang University, Beijing 100191 (China)

    2014-11-15

    In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

  3. Modeling and optimizing of the random atomic spin gyroscope drift based on the atomic spin gyroscope.

    Science.gov (United States)

    Quan, Wei; Lv, Lin; Liu, Baiqi

    2014-11-01

    In order to improve the atom spin gyroscope's operational accuracy and compensate the random error caused by the nonlinear and weak-stability characteristic of the random atomic spin gyroscope (ASG) drift, the hybrid random drift error model based on autoregressive (AR) and genetic programming (GP) + genetic algorithm (GA) technique is established. The time series of random ASG drift is taken as the study object. The time series of random ASG drift is acquired by analyzing and preprocessing the measured data of ASG. The linear section model is established based on AR technique. After that, the nonlinear section model is built based on GP technique and GA is used to optimize the coefficients of the mathematic expression acquired by GP in order to obtain a more accurate model. The simulation result indicates that this hybrid model can effectively reflect the characteristics of the ASG's random drift. The square error of the ASG's random drift is reduced by 92.40%. Comparing with the AR technique and the GP + GA technique, the random drift is reduced by 9.34% and 5.06%, respectively. The hybrid modeling method can effectively compensate the ASG's random drift and improve the stability of the system.

  4. Tight Bounds on the Optimization Time of a Randomized Search Heuristic on Linear Functions

    DEFF Research Database (Denmark)

    Witt, Carsten

    2013-01-01

    The analysis of randomized search heuristics on classes of functions is fundamental to the understanding of the underlying stochastic process and the development of suitable proof techniques. Recently, remarkable progress has been made in bounding the expected optimization time of a simple evolut...

  5. Best Spatiotemporal Performance Sustained by Optimal Number of Random Shortcuts on Complex Networks

    Institute of Scientific and Technical Information of China (English)

    WANG Mao-Sheng; HOU Zhong-Huai; XIN Hou-Wen

    2006-01-01

    @@ The spatial synchronization and temporal coherence of FitzHugh-Nagumo (FHN) neurons on complex networks are numerically investigated. When an optimal number of random shortcuts are added to a regular neural chain,the system can reach a state which is nearly periodic in time and almost synchronized in space.

  6. Selecting Optimal Parameters of Random Linear Network Coding for Wireless Sensor Networks

    DEFF Research Database (Denmark)

    Heide, Janus; Zhang, Qi; Fitzek, Frank

    2013-01-01

    This work studies how to select optimal code parameters of Random Linear Network Coding (RLNC) in Wireless Sensor Networks (WSNs). With Rateless Deluge [1] the authors proposed to apply Network Coding (NC) for Over-the-Air Programming (OAP) in WSNs, and demonstrated that with NC a significant...

  7. Optimizing Linear Functions with Randomized Search Heuristics - The Robustness of Mutation

    DEFF Research Database (Denmark)

    Witt, Carsten

    2012-01-01

    The analysis of randomized search heuristics on classes of functions is fundamental for the understanding of the underlying stochastic process and the development of suitable proof techniques. Recently, remarkable progress has been made in bounding the expected optimization time of the simple (1...

  8. Solving the wind farm layout optimization problem using random search algorithm

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong

    2015-01-01

    is presented, which starts from an initial feasible layout and then improves the layout iteratively in the feasible solution space. It was first proposed in our previous study and improved in this study by adding some adaptive mechanisms. It can serve both as a refinement tool to improve an initial design......Wind farm (WF) layout optimization is to find the optimal positions of wind turbines (WTs) inside a WF, so as to maximize and/or minimize a single objective or multiple objectives, while satisfying certain constraints. In this work, a random search (RS) algorithm based on continuous formulation...... by expert guesses or other optimization methods, and as an optimization tool to find the optimal layout of WF with a certain number of WTs. A new strategy to evaluate layouts is also used, which can largely save the computation cost. This method is first applied to a widely studied ideal test problem...

  9. Optimal paths planning in dynamic transportation networks with random link travel times

    Institute of Scientific and Technical Information of China (English)

    孙世超; 段征宇; 杨东援

    2014-01-01

    A theoretical study was conducted on finding optimal paths in transportation networks where link travel times were stochastic and time-dependent (STD). The methodology of relative robust optimization was applied as measures for comparing time-varying, random path travel times for a priori optimization. In accordance with the situation in real world, a stochastic consistent condition was provided for the STD networks and under this condition, a mathematical proof was given that the STD robust optimal path problem can be simplified into a minimum problem in specific time-dependent networks. A label setting algorithm was designed and tested to find travelers’ robust optimal path in a sampled STD network with computation complexity of O(n2+n·m). The validity of the robust approach and the designed algorithm were confirmed in the computational tests. Compared with conventional probability approach, the proposed approach is simple and efficient, and also has a good application prospect in navigation system.

  10. A dose optimization method for electron radiotherapy using randomized aperture beams.

    Science.gov (United States)

    Engel, Konrad; Gauer, Tobias

    2009-09-01

    The present paper describes the entire optimization process of creating a radiotherapy treatment plan for advanced electron irradiation. Special emphasis is devoted to the selection of beam incidence angles and beam energies as well as to the choice of appropriate subfields generated by a refined version of intensity segmentation and a novel random aperture approach. The algorithms have been implemented in a stand-alone programme using dose calculations from a commercial treatment planning system. For this study, the treatment planning system Pinnacle from Philips has been used and connected to the optimization programme using an ASCII interface. Dose calculations in Pinnacle were performed by Monte Carlo simulations for a remote-controlled electron multileaf collimator (MLC) from Euromechanics. As a result, treatment plans for breast cancer patients could be significantly improved when using randomly generated aperture beams. The combination of beams generated through segmentation and randomization achieved the best results in terms of target coverage and sparing of critical organs. The treatment plans could be further improved by use of a field reduction treatment plans could be further improved by use of a field reduction algorithm. Without a relevant loss in dose distribution, the total number of MLC fields and monitor units could be reduced by up to 20%. In conclusion, using randomized aperture beams is a promising new approach in radiotherapy and exhibits potential for further improvements in dose optimization through a combination of randomized electron and photon aperture beams.

  11. Optimized quantum random-walk search algorithm for multi-solution search

    Institute of Scientific and Technical Information of China (English)

    张宇超; 鲍皖苏; 汪翔; 付向群

    2015-01-01

    This study investigates the multi-solution search of the optimized quantum random-walk search algorithm on the hypercube. Through generalizing the abstract search algorithm which is a general tool for analyzing the search on the graph to the multi-solution case, it can be applied to analyze the multi-solution case of quantum random-walk search on the graph directly. Thus, the computational complexity of the optimized quantum random-walk search algorithm for the multi-solution search is obtained. Through numerical simulations and analysis, we obtain a critical value of the proportion of solutions q. For a given q, we derive the relationship between the success rate of the algorithm and the number of iterations when q is no longer than the critical value.

  12. Time reversal versus adaptive optimization for spatiotemporal nanolocalization in a random nanoantenna

    Science.gov (United States)

    Differt, Dominik; Hensen, Matthias; Pfeiffer, Walter

    2016-05-01

    Spatiotemporal nanolocalization of ultrashort pulses in a random scattering nanostructure via time reversal and adaptive optimization employing a genetic algorithm and a suitably defined fitness function is studied for two embedded nanoparticles that are separated by only a tenth of the free space wavelength. The nanostructure is composed of resonant core-shell nanoparticles (TiO2 core and Ag shell) placed randomly surrounding these two nanoparticles acting as targets. The time reversal scheme achieves selective nanolocalization only by chance if the incident radiation can couple efficiently to dipolar local modes interacting with the target/emitter particle. Even embedding the structure in a reverberation chamber fails improving the nanolocalization. In contrast, the adaptive optimization strategy reliably yields nanolocalization of the radiation and allows a highly selective excitation of either target position. This demonstrates that random scattering structures are interesting multi-purpose optical nanoantennas to realize highly flexible spatiotemporal optical near-field control.

  13. Probabilistic Design and Random Optimization of Aerofoil Wing by Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Mr.Sachin M. Shinde

    2013-09-01

    Full Text Available This study represents simulation of aerofoil composite beam by using Monte Carlo method i.e.direct sampling. A three dimensional transient analysis of large displacement type has been carried out.Finite element analysis of NACA0012 aerofoil composite structure has been carried out and uncertainty in bending stress is analyzed. More over optimization of selected design variables has been carried out by using random optimization method. Bending stress was objective function.Chord length , elastic modulus of epoxy graphite, ply angle of aerofoil section, Beam length , moment of inertia and force are randomly varied within effective range and their effect on bending stress has been analyzed.In order to validate the results, one loop of simulation is benchmarked from results in literature. Ultimately, best set of optimized design variable is proposed to reduce bending stress under different loading condition.

  14. A new logistic dynamic particle swarm optimization algorithm based on random topology.

    Science.gov (United States)

    Ni, Qingjian; Deng, Jianming

    2013-01-01

    Population topology of particle swarm optimization (PSO) will directly affect the dissemination of optimal information during the evolutionary process and will have a significant impact on the performance of PSO. Classic static population topologies are usually used in PSO, such as fully connected topology, ring topology, star topology, and square topology. In this paper, the performance of PSO with the proposed random topologies is analyzed, and the relationship between population topology and the performance of PSO is also explored from the perspective of graph theory characteristics in population topologies. Further, in a relatively new PSO variant which named logistic dynamic particle optimization, an extensive simulation study is presented to discuss the effectiveness of the random topology and the design strategies of population topology. Finally, the experimental data are analyzed and discussed. And about the design and use of population topology on PSO, some useful conclusions are proposed which can provide a basis for further discussion and research.

  15. Hierarchical random walks in trace fossils and the origin of optimal search behavior.

    Science.gov (United States)

    Sims, David W; Reynolds, Andrew M; Humphries, Nicolas E; Southall, Emily J; Wearmouth, Victoria J; Metcalfe, Brett; Twitchett, Richard J

    2014-07-29

    Efficient searching is crucial for timely location of food and other resources. Recent studies show that diverse living animals use a theoretically optimal scale-free random search for sparse resources known as a Lévy walk, but little is known of the origins and evolution of foraging behavior and the search strategies of extinct organisms. Here, using simulations of self-avoiding trace fossil trails, we show that randomly introduced strophotaxis (U-turns)--initiated by obstructions such as self-trail avoidance or innate cueing--leads to random looping patterns with clustering across increasing scales that is consistent with the presence of Lévy walks. This predicts that optimal Lévy searches may emerge from simple behaviors observed in fossil trails. We then analyzed fossilized trails of benthic marine organisms by using a novel path analysis technique and find the first evidence, to our knowledge, of Lévy-like search strategies in extinct animals. Our results show that simple search behaviors of extinct animals in heterogeneous environments give rise to hierarchically nested Brownian walk clusters that converge to optimal Lévy patterns. Primary productivity collapse and large-scale food scarcity characterizing mass extinctions evident in the fossil record may have triggered adaptation of optimal Lévy-like searches. The findings suggest that Lévy-like behavior has been used by foragers since at least the Eocene but may have a more ancient origin, which might explain recent widespread observations of such patterns among modern taxa.

  16. Comparison and optimization of randomly textured surfaces in thin-film solar cells.

    Science.gov (United States)

    Rockstuhl, C; Fahr, S; Bittkau, K; Beckers, T; Carius, R; Haug, F-J; Söderström, T; Ballif, C; Lederer, F

    2010-09-13

    Using rigorous diffraction theory we investigate the scattering properties of various random textures currently used for photon management in thin-film solar cells. We relate the haze and the angularly resolved scattering function of these cells to the enhancement of light absorption. A simple criterion is derived that provides an explanation why certain textures operate more beneficially than others. Using this criterion we propose a generic surface profile that outperforms the available substrates. This work facilitates the understanding of the effect of randomly textured surfaces and provides guidelines towards their optimization.

  17. The optimal dose of vitamin D in growing girls during academic years: a randomized trial

    OpenAIRE

    SHAKINBA, Mehrdad; TEFAGH, Samane; NAFEI, Zahra

    2011-01-01

    Prevalence of vitamin D deficiency is remarkable during childhood and adolescence throughout the world. Sufficient intake of vitamin D contributes to a number of health outcomes. The aim of this study was to specify the optimal dose of vitamin D in growing girls in a Muslim country during an academic year. Materials and methods: This randomized clinical trial study was carried out in Yazd in the center of Iran in 2007;120 junior high school girls (aged 12-15 years) were randomly divided into...

  18. Global optimization of manipulator base placement by means of rapidly-exploring random tree

    Institute of Scientific and Technical Information of China (English)

    赵京

    2016-01-01

    Due to the interrelationship between the base placement of the manipulator and its operation ob-ject , it is significant to analyze the accessibility and workspace of manipulators for the optimization of their base location.A new method is presented to optimize the base placement of manipulators through motion planning optimization and location optimization in the feasible area for manipulators. Firstly, research problems and contents are outlined.And then the feasible area for the manipulator base installation is discussed.Next, index depended on the joint movements and used to evaluate the kinematic performance of manipulators is defined.Although the mentioned indices in last section are regarded as the cost function of the latter,rapidly-exploring random tree ( RRT) and rapidly-ex-ploring random tree*( RRT*) algorithms are analyzed.And then, the proposed optimization method of manipulator base placement is studied by means of simulation research based on kinematic per-formance criteria.Finally, the conclusions could be proved effective from the simulation results.

  19. Optimization of Wind Farm Layout: A Refinement Method by Random Search

    DEFF Research Database (Denmark)

    Yang, Jianchuan; Feng, Ju; Shen, Wen Zhong

    2013-01-01

    turbines can be placed, hence, simplifying the problem from with continuous variables to with discrete variables. In this paper, a refinement method, based on continuous formulation, by using random search is proposed to improve the optimization results based on discrete formulations. Two sets...... of optimization results of a widely studied test case are refined using the proposed method. One set of the results is from a published work using GA based on discrete formulation, the other set is the improved results using authors’ own GA code. Steady improvements are obtained for both sets of results....

  20. Optimal random perturbations for stochastic approximation using a simultaneous perturbation gradient approximation

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1998-01-01

    The simultaneous perturbation stochastic approximation (SPSA) algorithm has attracted considerable attention for challenging optimization problems where it is difficult or impossible to obtain a direct gradient of the objective (say, loss) function. The approach is based on a highly efficient...... simultaneous perturbation approximation to the gradient based on loss function measurements. SPSA is based on picking a simultaneous perturbation (random) vector in a Monte Carlo fashion as part of generating the approximation to the gradient. This paper derives the optimal distribution for the Monte Carlo...

  1. Optimal random perturbations for stochastic approximation using a simultaneous perturbation gradient approximation

    DEFF Research Database (Denmark)

    Sadegh, Payman; Spall, J. C.

    1997-01-01

    The simultaneous perturbation stochastic approximation (SPSA) algorithm has recently attracted considerable attention for optimization problems where it is difficult or impossible to obtain a direct gradient of the objective (say, loss) function. The approach is based on a highly efficient...... simultaneous perturbation approximation to the gradient based on loss function measurements. SPSA is based on picking a simultaneous perturbation (random) vector in a Monte Carlo fashion as part of generating the approximation to the gradient. This paper derives the optimal distribution for the Monte Carlo...

  2. A randomized controlled trial testing an adherence-optimized Vitamin D regimen to mitigate bone change in adolescents being treated for acute lymphoblastic leukemia.

    Science.gov (United States)

    Orgel, Etan; Mueske, Nicole M; Sposto, Richard; Gilsanz, Vicente; Wren, Tishya A L; Freyer, David R; Butturini, Anna M; Mittelman, Steven D

    2017-10-01

    Adolescents with acute lymphoblastic leukemia (ALL) develop osteopenia early in therapy, potentially exacerbated by high rates of concurrent Vitamin D deficiency. We conducted a randomized clinical trial testing a Vitamin D-based intervention to improve Vitamin D status and reduce bone density decline. Poor adherence to home supplementation necessitated a change to directly observed therapy (DOT) with intermittent, high-dose Vitamin D3 randomized versus standard of care (SOC). Compared to SOC, DOT Vitamin D3 successfully increased trough Vitamin 25(OH)D levels (p = .026) with no residual Vitamin D deficiency, 100% adherence to DOT Vitamin D3, and without associated toxicity. However, neither Vitamin D status nor supplementation impacted bone density. Thus, this adherence-optimized intervention is feasible and effective to correct Vitamin D deficiency in adolescents during ALL therapy. Repletion of Vitamin D and calcium alone did not mitigate osteopenia, however, and new, comprehensive approaches are needed to address treatment-associated osteopenia during ALL therapy.

  3. Convergence of quasi-optimal Stochastic Galerkin methods for a class of PDES with random coefficients

    KAUST Repository

    Beck, Joakim

    2014-03-01

    In this work we consider quasi-optimal versions of the Stochastic Galerkin method for solving linear elliptic PDEs with stochastic coefficients. In particular, we consider the case of a finite number N of random inputs and an analytic dependence of the solution of the PDE with respect to the parameters in a polydisc of the complex plane CN. We show that a quasi-optimal approximation is given by a Galerkin projection on a weighted (anisotropic) total degree space and prove a (sub)exponential convergence rate. As a specific application we consider a thermal conduction problem with non-overlapping inclusions of random conductivity. Numerical results show the sharpness of our estimates. © 2013 Elsevier Ltd. All rights reserved.

  4. A Simulation Optimization Algorithm for CTMDPs Based on Randomized Stationary Policies1)

    Institute of Scientific and Technical Information of China (English)

    TANGHao; XIHong-Sheng; YINBao-Qun

    2004-01-01

    Based on the theory of Markov performance potentials and neuro-dynamic programming(NDP) methodology, we study simulation optimization algorithm for a class of continuous timeMarkov decision processes (CTMDPs) under randomized stationary policies. The proposed algo-rithm will estimate the gradient of average cost performance measure with respect to policy param-eters by transforming a continuous time Markov process into a uniform Markov chain and simula-ting a single sample path of the chain. The goal is to look for a suboptimal randomized stationarypolicy. The algorithm derived here can meet the needs of performance optimization of many diffi-cult systems with large-scale state space. Finally, a numerical example for a controlled Markovprocess is provided.

  5. Analysis and Optimization of Sparse Random Linear Network Coding for Reliable Multicast Services

    DEFF Research Database (Denmark)

    Tassi, Andrea; Chatzigeorgiou, Ioannis; Roetter, Daniel Enrique Lucani

    2016-01-01

    Point-to-multipoint communications are expected to play a pivotal role in next-generation networks. This paper refers to a cellular system transmitting layered multicast services to a multicast group of users. Reliability of communications is ensured via different random linear network coding (RL...... guarantees to predetermined fractions of users. The performance of the proposed optimization framework is then investigated in a LTE-A eMBMS network multicasting H.264/SVC video services....

  6. On dual descriptions of intermittency in a jet

    CERN Document Server

    Peschanski, R

    1996-01-01

    Models of intermittent behaviour are usually formulated using a set of multiplicative random weights on a Cayley tree. However, intermittency in particle multiproduction from QCD jets is related to fragmentation of an additive quantum number, e.g. energy-momentum. We exhibit the non-trivial stochastic mapping between these {\\it additive} and {\\it multiplicative} cascading processes.

  7. Interpolating between random walks and optimal transportation routes: Flow with multiple sources and targets

    Science.gov (United States)

    Guex, Guillaume

    2016-05-01

    In recent articles about graphs, different models proposed a formalism to find a type of path between two nodes, the source and the target, at crossroads between the shortest-path and the random-walk path. These models include a freely adjustable parameter, allowing to tune the behavior of the path toward randomized movements or direct routes. This article presents a natural generalization of these models, namely a model with multiple sources and targets. In this context, source nodes can be viewed as locations with a supply of a certain good (e.g. people, money, information) and target nodes as locations with a demand of the same good. An algorithm is constructed to display the flow of goods in the network between sources and targets. With again a freely adjustable parameter, this flow can be tuned to follow routes of minimum cost, thus displaying the flow in the context of the optimal transportation problem or, by contrast, a random flow, known to be similar to the electrical current flow if the random-walk is reversible. Moreover, a source-targetcoupling can be retrieved from this flow, offering an optimal assignment to the transportation problem. This algorithm is described in the first part of this article and then illustrated with case studies.

  8. Optimal state estimation for networked systems with random parameter matrices, correlated noises and delayed measurements

    Science.gov (United States)

    Caballero-Águila, R.; Hermoso-Carazo, A.; Linares-Pérez, J.

    2015-02-01

    In this paper, the optimal least-squares state estimation problem is addressed for a class of discrete-time multisensor linear stochastic systems with state transition and measurement random parameter matrices and correlated noises. It is assumed that at any sampling time, as a consequence of possible failures during the transmission process, one-step delays with different delay characteristics may occur randomly in the received measurements. The random delay phenomenon is modelled by using a different sequence of Bernoulli random variables in each sensor. The process noise and all the sensor measurement noises are one-step autocorrelated and different sensor noises are one-step cross-correlated. Also, the process noise and each sensor measurement noise are two-step cross-correlated. Based on the proposed model and using an innovation approach, the optimal linear filter is designed by a recursive algorithm which is very simple computationally and suitable for online applications. A numerical simulation is exploited to illustrate the feasibility of the proposed filtering algorithm.

  9. Intermittent degradation and schizotypy

    Directory of Open Access Journals (Sweden)

    Matthew W. Roché

    2015-06-01

    Full Text Available Intermittent degradation refers to transient detrimental disruptions in task performance. This phenomenon has been repeatedly observed in the performance data of patients with schizophrenia. Whether intermittent degradation is a feature of the liability for schizophrenia (i.e., schizotypy is an open question. Further, the specificity of intermittent degradation to schizotypy has yet to be investigated. To address these questions, 92 undergraduate participants completed a battery of self-report questionnaires assessing schizotypy and psychological state variables (e.g., anxiety, depression, and their reaction times were recorded as they did so. Intermittent degradation was defined as the number of times a subject’s reaction time for questionnaire items met or exceeded three standard deviations from his or her mean reaction time after controlling for each item’s information processing load. Intermittent degradation scores were correlated with questionnaire scores. Our results indicate that intermittent degradation is associated with total scores on measures of positive and disorganized schizotypy, but unrelated to total scores on measures of negative schizotypy and psychological state variables. Intermittent degradation is interpreted as potentially derivative of schizotypy and a candidate endophenotypic marker worthy of continued research.

  10. Particle swarm optimization with random keys applied to the nuclear reactor reload problem

    Energy Technology Data Exchange (ETDEWEB)

    Meneses, Anderson Alvarenga de Moura [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear; Fundacao Educacional de Macae (FUNEMAC), RJ (Brazil). Faculdade Professor Miguel Angelo da Silva Santos; Machado, Marcelo Dornellas; Medeiros, Jose Antonio Carlos Canedo; Schirru, Roberto [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE). Programa de Engenharia Nuclear]. E-mails: ameneses@con.ufrj.br; marcelo@lmp.ufrj.br; canedo@lmp.ufrj.br; schirru@lmp.ufrj.br

    2007-07-01

    In 1995, Kennedy and Eberhart presented the Particle Swarm Optimization (PSO), an Artificial Intelligence metaheuristic technique to optimize non-linear continuous functions. The concept of Swarm Intelligence is based on the socials aspects of intelligence, it means, the ability of individuals to learn with their own experience in a group as well as to take advantage of the performance of other individuals. Some PSO models for discrete search spaces have been developed for combinatorial optimization, although none of them presented satisfactory results to optimize a combinatorial problem as the nuclear reactor fuel reloading problem (NRFRP). In this sense, we developed the Particle Swarm Optimization with Random Keys (PSORK) in previous research to solve Combinatorial Problems. Experiences demonstrated that PSORK performed comparable to or better than other techniques. Thus, PSORK metaheuristic is being applied in optimization studies of the NRFRP for Angra 1 Nuclear Power Plant. Results will be compared with Genetic Algorithms and the manual method provided by a specialist. In this experience, the problem is being modeled for an eight-core symmetry and three-dimensional geometry, aiming at the minimization of the Nuclear Enthalpy Power Peaking Factor as well as the maximization of the cycle length. (author)

  11. The effects of continuous and intermittent aerobic exercise on lipid profile and fasting blood sugar in women with a body mass index more than 25 kg/m2: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Alizadeh Z

    2011-07-01

    Full Text Available "n 800x600 Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Background: Obesity is a major health problem all around the world. On the other hand, few people, especially women, are physically active to the levels recommended by Healthy People 2010 web site managed by the U.S. Department of Health and Human Services. The objective of this study was to compare the potential effects of intermittent and continuous exercise programs combined with concurrent calorie restriction diets on lipid profile and fasting blood sugar in overweight and obese females."n"nMethods : Forty-five women with a sedentary life style and a BMI greater than 25 kg/m2, were randomly assigned to one of the three groups (15 subjects in each group: a 40 minutes of medium-intensity intermittent exercise (64-76% of maximal heart rate, 3 bouts per day for 5 days a week, b a single bout of a 40-minute continuous exercise per day for 5 days a week, C the non-exercising control group. A self-monitored calorie restricted diet was recommended to all participants by a dietitian. The lipid profile, fasting blood sugar and blood pressure of all participants were assessed at baseline and 12 weeks after the intervention period."n"nResults : After the intervention, there were no significant differences among the groups in terms of lipid profile [cholesterol (P=0.94, triglyceride (P=0.62] fasting blood sugar (P=0.054, systolic blood pressure (P=0.84 or diastolic blood pressure (P=0.30."n"nConclusion: There seems to be no significant differences between short term continuous and intermittent aerobic

  12. Ultra low vertical emittance at SLS through systematic and random optimization

    CERN Document Server

    Aiba, M.; Milas, N.; Streun, A.

    2012-01-01

    A new vertical emittance record of 0.9+-0.4 pm rad was established in the storage ring of the Swiss Light Source (SLS) at 2.4 GeV by the application of a sequence of methods: Magnet girders were remotely vertically realigned in order to suppress the dipolar fields that produce the spurious dispersion in the vertical plane. A systematic optimization was then performed by measuring and correcting the betatron coupling and the vertical dispersion by means of 36 skew quadrupole correctors. The correction is performed until a limit is reached from the orbit response matrix (ORM) measurement errors and residual model deficiencies. At this point, the method of random optimization (RO), a multi-variable optimization procedure, was invoked. In the present experiment, the vertical beam size is the target function while the skew quadrupole currents act as the correction variables. The methodology of RO and the systematic correction scheme are described.

  13. Cooperative controls with intermittent communication

    Science.gov (United States)

    Shen, Dan; Chen, Genshe; Cruz, Jose B., Jr.; Pham, Khanh; Blasch, Erik; Lynch, Robert

    2010-04-01

    In this paper, we propose a solution to the cooperative path planning with limited communication problem in two phases. In the first (offline) phase, a Pareto-optimal path problem is formulated to find a reference path and the graph cuts minimization method is used to speedily calculate the optimal solution. In the second (online) phase, a foraging algorithm is used to dynamically refine the reference path to meet the dynamic constraints of unmanned aerial vehicle (UAVs), during which an open-loop feedback optimal (OLFO) controller is used to estimate the states which may be unavailable due to infrequent battlefield information updates. Furthermore, an adaptive Markov decision process is proposed to deal with intermittent asynchronous information flow. The method is demonstrated in a simulation for a swarm of Unmanned Air Vehicle (UAV) teams with various communication ranges.

  14. Optimal Attack Strategy in Random Scale-Free Networks Based on Incomplete Information

    Institute of Scientific and Technical Information of China (English)

    LI Jun; WU Jun; LI Yong; DENG Hong-Zhong; TAN Yue-Jin

    2011-01-01

    @@ We introduce an attack model based on incomplete information, which means that we can obtain the information from partial nodes.We investigate the optimal attack strategy in random scale-free networks both analytically and numerically.We show that the attack strategy can affect the attack effect remarkably and the OAS can achieve better attack effect than other typical attack strategies.It is found that when the attack intensity is small, the attacker should attack more nodes in the "white area" in which we can obtain attack information; when the attack intensity is greater, the attacker should attack more nodes in the "black area" in which we can not obtain attack information.Moreover, we show that there is an inflection point in the curve of optimal attack proportion.For a given magnitude of attack information, the optimal attack proportion decreases with the attack intensity before the inflection point and then increases after the inflection point.%We introduce an attack model based on incomplete information, which means that we can obtain the information from partial nodes. We investigate the optimal attack strategy in random scale-free networks both analytically and numerically. We show that the attack strategy can affect the attack effect remarkably and the OAS can achieve better attack effect than other typical attack strategies. It is found that when the attack intensity is small, the attacker should attack more nodes in the "white area" in which we can obtain attack information; when the attack intensity is greater, the attacker should attack more nodes in the "black area" in which we can not obtain attack information. Moreover, we show that there is an inflection point in the curve of optimal attack proportion. For a given magnitude of attack information, the optimal attack proportion decreases with the attack intensity before the inflection point and then increases after the inflection point.

  15. Defining "intermittent UVR exposure"

    DEFF Research Database (Denmark)

    Bodekær, Mette; Philipsen, Peter Alshede; Petersen, Bibi Øager;

    2016-01-01

    to define and quantify “intermittent UVR exposure” by an objective measure. Methods: A broad study population of adults and children had data collected during a summer period. Data were personal UVR dosimetry measurements, from which the number of “intermittent days” was derived, sun behaviour diaries.......001). The corresponding numbers for prediction of nevi and lentigo density by retrospective questionnaire data was lower (R2 = 0.11, R2 = 0.26, p defined objective measure of intermittent UVR exposure. This measure may provide a better prediction of solar skin damage and CMM...

  16. Stochastic optimal foraging: tuning intensive and extensive dynamics in random searches.

    Directory of Open Access Journals (Sweden)

    Frederic Bartumeus

    Full Text Available Recent theoretical developments had laid down the proper mathematical means to understand how the structural complexity of search patterns may improve foraging efficiency. Under information-deprived scenarios and specific landscape configurations, Lévy walks and flights are known to lead to high search efficiencies. Based on a one-dimensional comparative analysis we show a mechanism by which, at random, a searcher can optimize the encounter with close and distant targets. The mechanism consists of combining an optimal diffusivity (optimally enhanced diffusion with a minimal diffusion constant. In such a way the search dynamics adequately balances the tension between finding close and distant targets, while, at the same time, shifts the optimal balance towards relatively larger close-to-distant target encounter ratios. We find that introducing a multiscale set of reorientations ensures both a thorough local space exploration without oversampling and a fast spreading dynamics at the large scale. Lévy reorientation patterns account for these properties but other reorientation strategies providing similar statistical signatures can mimic or achieve comparable efficiencies. Hence, the present work unveils general mechanisms underlying efficient random search, beyond the Lévy model. Our results suggest that animals could tune key statistical movement properties (e.g. enhanced diffusivity, minimal diffusion constant to cope with the very general problem of balancing out intensive and extensive random searching. We believe that theoretical developments to mechanistically understand stochastic search strategies, such as the one here proposed, are crucial to develop an empirically verifiable and comprehensive animal foraging theory.

  17. Comparisons of treatment optimization directly incorporating random patient setup uncertainty with a margin-based approach.

    Science.gov (United States)

    Moore, Joseph A; Gordon, John J; Anscher, Mitchell S; Siebers, Jeffrey V

    2009-09-01

    The purpose of this study is to incorporate the dosimetric effect of random patient positioning uncertainties directly into a commercial treatment planning system's IMRT plan optimization algorithm through probabilistic treatment planning (PTP) and compare coverage of this method with margin-based planning. In this work, PTP eliminates explicit margins and optimizes directly on the estimated integral treatment dose to determine optimal patient dose in the presence of setup uncertainties. Twenty-eight prostate patient plans adhering to the RTOG-0126 criteria are optimized using both margin-based and PTP methods. Only random errors are considered. For margin-based plans, the planning target volume is created by expanding the clinical target volume (CTV) by 2.1 mm to accommodate the simulated 3 mm random setup uncertainty. Random setup uncertainties are incorporated into IMRT dose evaluation by convolving each beam's incident fluence with a sigma = 3 mm Gaussian prior to dose calculation. PTP optimization uses the convolved fluence to estimate dose to ensure CTV coverage during plan optimization. PTP-based plans are compared to margin-based plans with equal CTV coverage in the presence of setup errors based on dose-volume metrics. The sensitivity of the optimized plans to patient-specific setup uncertainty variations is assessed by evaluating dose metrics for dose distributions corresponding to halving and doubling of the random setup uncertainty used in the optimization. Margin-based and PTP-based plans show similar target coverage. A physician review shows that PTP is preferred for 21 patients, margin-based plans are preferred in 2 patients, no preference is expressed for 1 patient, and both autogenerated plans are rejected for 4 patients. For the PTP-based plans, the average CTV receiving the prescription dose decreases by 0.5%, while the mean dose to the CTV increases by 0.7%. The CTV tumor control probability (TCP) is the same for both methods with the exception

  18. Intermittent Explosive Disorder

    Directory of Open Access Journals (Sweden)

    Lut Tamam

    2011-09-01

    Full Text Available Intermittent explosive disorder is an impulse control disorder characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Though the prevalence intermittent explosive disorder has been reported to be relatively rare in frontier studies on the field, it is now common opinion that intermittent explosive disorder is far more common than previously thought especially in clinical psychiatry settings. Etiological studies displayed the role of both psychosocial factors like childhood traumas and biological factors like dysfunctional neurotransmitter systems and genetics. In differential diagnosis of the disorder, disorders involving agression as a symptom such as alcohol and drug intoxication, antisocial and borderline personality disorders, personality changes due to general medical conditions and behavioral disorder should be considered. A combination of pharmacological and psychotherapeutic approaches are suggested in the treatment of the disorder. This article briefly reviews the historical background, diagnostic criteria, epidemiology, etiology and treatment of intermittent explosive disorder.

  19. Sample size calculation in cost-effectiveness cluster randomized trials: optimal and maximin approaches.

    Science.gov (United States)

    Manju, Md Abu; Candel, Math J J M; Berger, Martijn P F

    2014-07-10

    In this paper, the optimal sample sizes at the cluster and person levels for each of two treatment arms are obtained for cluster randomized trials where the cost-effectiveness of treatments on a continuous scale is studied. The optimal sample sizes maximize the efficiency or power for a given budget or minimize the budget for a given efficiency or power. Optimal sample sizes require information on the intra-cluster correlations (ICCs) for effects and costs, the correlations between costs and effects at individual and cluster levels, the ratio of the variance of effects translated into costs to the variance of the costs (the variance ratio), sampling and measuring costs, and the budget. When planning, a study information on the model parameters usually is not available. To overcome this local optimality problem, the current paper also presents maximin sample sizes. The maximin sample sizes turn out to be rather robust against misspecifying the correlation between costs and effects at the cluster and individual levels but may lose much efficiency when misspecifying the variance ratio. The robustness of the maximin sample sizes against misspecifying the ICCs depends on the variance ratio. The maximin sample sizes are robust under misspecification of the ICC for costs for realistic values of the variance ratio greater than one but not robust under misspecification of the ICC for effects. Finally, we show how to calculate optimal or maximin sample sizes that yield sufficient power for a test on the cost-effectiveness of an intervention.

  20. Make Better Choices (MBC: Study design of a randomized controlled trial testing optimal technology-supported change in multiple diet and physical activity risk behaviors

    Directory of Open Access Journals (Sweden)

    Smith Malaina

    2010-09-01

    Full Text Available Abstract Background Suboptimal diet and physical inactivity are prevalent, co-occurring chronic disease risk factors, yet little is known about how to maximize multiple risk behavior change. Make Better Choices, a randomized controlled trial, tests competing hypotheses about the optimal way to promote healthy change in four bundled risk behaviors: high saturated fat intake, low fruit and vegetable intake, low physical activity, and high sedentary leisure screen time. The study aim is to determine which combination of two behavior change goals - one dietary, one activity - yields greatest overall healthy lifestyle change. Methods/Design Adults (n = 200 with poor quality diet and sedentary lifestyle will be recruited and screened for study eligibility. Participants will be trained to record their diet and activities onto a personal data assistant, and use it to complete two weeks of baseline. Those who continue to show all four risk behaviors after baseline recording will be randomized to one of four behavior change prescriptions: 1 increase fruits and vegetables and increase physical activity, 2 decrease saturated fat and increase physical activity, 3 increase fruits and vegetable and decrease saturated fat, or 4 decrease saturated fat and decrease sedentary activity. They will use decision support feedback on the personal digital assistant and receive counseling from a coach to alter their diet and activity during a 3-week prescription period when payment is contingent upon meeting behavior change goals. They will continue recording on an intermittent schedule during a 4.5-month maintenance period when payment is not contingent upon goal attainment. The primary outcome is overall healthy lifestyle change, aggregated across all four risk behaviors. Discussion The Make Better Choices trial tests a disseminable lifestyle intervention supported by handheld technology. Findings will fill a gap in knowledge about optimal goal prescription to

  1. Towards Optimal Degree-distributions for Left-perfect Matchings in Random Bipartite Graphs

    CERN Document Server

    Dietzfelbinger, Martin

    2012-01-01

    Consider a random bipartite multigraph $G$ with $n$ left nodes and $m \\geq n \\geq 2$ right nodes. Each left node $x$ has $d_x \\geq 1$ random right neighbors. The average left degree $\\Delta$ is fixed, $\\Delta \\geq 2$. We ask whether for the probability that $G$ has a left-perfect matching it is advantageous not to fix $d_x$ for each left node $x$ but rather choose it at random according to some (cleverly chosen) distribution. We show the following, provided that the degrees of the left nodes are independent: If $\\Delta$ is an integer then it is optimal to use a fixed degree of $\\Delta$ for all left nodes. If $\\Delta$ is non-integral then an optimal degree-distribution has the property that each left node $x$ has two possible degrees, $\\floor{\\Delta}$ and $\\ceil{\\Delta}$, with probability $p_x$ and $1-p_x$, respectively, where $p_x$ is from the closed interval $[0,1]$ and the average over all $p_x$ equals $\\ceil{\\Delta}-\\Delta$. Furthermore, if $n=c\\cdot m$ and $\\Delta>2$ is constant, then each distribution of...

  2. Submicron structure random field on granular soil material with retinex algorithm optimization

    Science.gov (United States)

    Liang, Yu; Tao, Chenyuan; Zhou, Bingcheng; Huang, Shuai; Huang, Linchong

    2017-06-01

    In this paper, a Retinex scale optimized image enhancement algorithm is proposed, which can enhance the micro vision image and eliminate the influence of the uneven illumination. Based on that, a random geometric model of the microstructure of granular materials is established with Monte-Carlo method, the numerical simulation including consolidation process of granular materials is compared with the experimental data. The results have proved that the random field method with Retinex image enhancement algorithm is effective, the image of microstructure of granular materials becomes clear and the contrast ratio is improved, after using Retinex image enhancement algorithm to enhance the CT image. The fidelity of enhanced image is higher than that dealing with other method, which have explained that the algorithm can preserve the microstructure information of the image well. The result of numerical simulation is similar with the one obtained from conventional three axis consolidation test, which proves that the simulation result is reliable.

  3. Implementation of unused production factors in agriculture by means of dynamic optimization models with random constraints

    Directory of Open Access Journals (Sweden)

    Jadwiga Zaród

    2011-01-01

    Full Text Available The farms of Western Pomerania province possess a large surplus of manpower. The dynamic optimization models with random constraints served the investigation of the possibilities of implementation of the unused man-hours. Those models regarded four successive years 2003-2006. The solution proceeded in two steps. The first step let us construct the assumption of the surplus or the deficiency of production factors. In the next step additional variables regarding the lease of arable grounds were introduced while the unused man-hours were implemented with various probability. The optimal solutions indicated the area of particular crops, the quantity of livestock and the farm income dependent on the use of the existing employment. This study aims at the presentation of the possibility of implementation of unused man-hours in farms dealing solely with the crop production and also the production of crop and livestock.

  4. On Generating Optimal Signal Probabilities for Random Tests: A Genetic Approach

    Directory of Open Access Journals (Sweden)

    M. Srinivas

    1996-01-01

    Full Text Available Genetic Algorithms are robust search and optimization techniques. A Genetic Algorithm based approach for determining the optimal input distributions for generating random test vectors is proposed in the paper. A cost function based on the COP testability measure for determining the efficacy of the input distributions is discussed. A brief overview of Genetic Algorithms (GAs and the specific details of our implementation are described. Experimental results based on ISCAS-85 benchmark circuits are presented. The performance of our GAbased approach is compared with previous results. While the GA generates more efficient input distributions than the previous methods which are based on gradient descent search, the overheads of the GA in computing the input distributions are larger.

  5. Managing Emergencies Optimally Using a Random Neural Network-Based Algorithm

    Directory of Open Access Journals (Sweden)

    Qing Han

    2013-10-01

    Full Text Available Emergency rescues require that first responders provide support to evacuate injured and other civilians who are obstructed by the hazards. In this case, the emergency personnel can take actions strategically in order to rescue people maximally, efficiently and quickly. The paper studies the effectiveness of a random neural network (RNN-based task assignment algorithm involving optimally matching emergency personnel and injured civilians, so that the emergency personnel can aid trapped people to move towards evacuation exits in real-time. The evaluations are run on a decision support evacuation system using the Distributed Building Evacuation Simulator (DBES multi-agent platform in various emergency scenarios. The simulation results indicate that the RNN-based task assignment algorithm provides a near-optimal solution to resource allocation problems, which avoids resource wastage and improves the efficiency of the emergency rescue process.

  6. Structured Home-Based Exercise Versus Invasive Treatment: A Mission Impossible? A Pilot Randomized Study in Elderly Patients With Intermittent Claudication.

    Science.gov (United States)

    Lamberti, Nicola; Malagoni, Anna Maria; Ficarra, Valentina; Basaglia, Nino; Manfredini, Roberto; Zamboni, Paolo; Mascoli, Francesco; Manfredini, Fabio

    2016-09-01

    We compared the effects of an original structured home-based exercise program and revascularization in elderly patients with peripheral arterial disease over a 4-month period. Twenty-seven participants (n = 21; age = 68 ± 7 years) with moderate to severe claudication were randomized into (1) a test in-train out group (Ti-To; n = 18) that performed a home-based walking program prescribed and controlled at the hospital or (2) a revascularization group (Rev; n = 9) that underwent an endovascular and/or surgical procedure. The primary end point was quality of life as evaluated by the physical component summary (PCS) score of the Medical Outcomes Study Short Form 36 questionnaire. Secondary outcome measures included initial claudication distance (ICD) and absolute claudication distance (ACD), 6-minute walk distance (6MWD) and pain-free walk distance (PFWD), ankle-brachial index (ABI), and cost per walking meter gained. The PCS score significantly increased for both treatments at follow-up without a significant intergroup difference, as did ICD, ACD, and PFWD. The 6MWD and ABI significantly improved in the Rev group, and the Ti-To group exhibited a markedly lower cost per meter gained. The comparable effects of the 2 treatments need to be confirmed in a larger, randomized controlled trial.

  7. A clinical observation on the far stereopsis examination for determine the optimal time for operation of the intermittent exotropia%远立体视测定对间歇性外斜视手术时机选择的临床观察

    Institute of Scientific and Technical Information of China (English)

    刘垠; 戴鸿斌; 宋天勤

    2000-01-01

    Objective To study the optimal time for operation of intermittent exotropia, so that we can orthopia strabismus and attain normal binocular function. Method Using the Yan′s far and near random-dot stereogram to examine 69 intermittent exotropia patient′s stereoacuity before and after the operation. Using the prism to examine the far and near of strabismus. Using the synoptophore to examine the binocular function. Result Among the 69 intermittent exotropia patients, only four had passed the far stereopsis before the operation and 47 had passed the near stereopsis. This difference between the two groups was statistically significant (P < 0.001 ). After the operation, 37patients had passed the far stereopsis and it was statistically significant different ( P < 0. 001 ) compared with that of pre-operation. There was no statisticaly significant difference between the pre-oeration group and the post-operation group concerning the near stereopsis. Patient with long course disease was more difficult to attain the stereopsis than that with shorter disease duration. Conclusion Examining the far and near stereoacuity is of benefit to determine the optimal time of the intermittent exotropia operation, and is valuable for evaluating the therapeutic effect.%目的 探讨间歇性外斜视最佳手术时机,以求达到矫正斜视并获得完善的双眼单视功能目的。方法 采用颜氏远用和近用随机点立体图,对69例间歇性外斜视进行手术前后立体视锐度测定;用三棱镜法测量远近斜视角;用同视机法测定双眼单视功能。结果69例间歇性外斜视中术前4例通过远立体视,47例通过近立体视,二者有高度显著性差异(P<0.001);术后37例通过远立体视,与术前比较有高度显著性差异(P<0.001),而近立体视手术前后无明显差异;病程愈长,术后获得立体视者愈少,病程短则相反。结论通过测定远近立体视,合理掌握间歇性外斜视手术

  8. Effects of a 12-week, short-interval, intermittent, low-intensity, slow-jogging program on skeletal muscle, fat infiltration, and fitness in older adults: randomized controlled trial.

    Science.gov (United States)

    Ikenaga, Masahiro; Yamada, Yosuke; Kose, Yujiro; Morimura, Kazuhiro; Higaki, Yasuki; Kiyonaga, Akira; Tanaka, Hiroaki

    2017-01-01

    We developed a short-interval, low-intensity, slow-jogging (SJ) program consisting of sets of 1 min of SJ at walking speed and 1 min of walking. We aimed to examine the effects of an easily performed SJ program on skeletal muscle, fat infiltration, and fitness in older adults. A total of 81 community-dwelling, independent, older adults (70.8 ± 4.0 years) were randomly assigned to the SJ or control group. The SJ group participants were encouraged to perform 90 min of SJ at their anaerobic threshold (AT) intensity and 90 min of walking intermittently per week. Aerobic capacity at the AT and sit-to-stand (STS) scores were measured. Intracellular water (ICW) in the legs was assessed by segmental multi-frequency bioelectrical impedance analysis. Subcutaneous (SAT) and intermuscular (IMAT) adipose tissue and muscle cross-sectional area (CSA) were measured at the mid-thigh using computed tomography. A total of 75 participants (37 SJ group, 38 controls) completed the 12-week intervention. The AT and STS improved in the SJ group compared with the controls (AT 15.7 vs. 4.9 %, p increased only in the SJ group (9.7 %, p decreased only in the SJ group (p muscle mass, improved aerobic capacity, muscle function, and muscle composition in older adults.

  9. Normobaric Intermittent Hypoxia over 8 Months Does Not Reduce Body Weight and Metabolic Risk Factors - a Randomized, Single Blind, Placebo-Controlled Study in Normobaric Hypoxia and Normobaric Sham Hypoxia

    Directory of Open Access Journals (Sweden)

    Hannes Gatterer

    2015-05-01

    Full Text Available Objective: Both a 1- to 4-week continuous or intermittent stay and moderate exercise in hypoxia versus normoxia can lead to weight loss. We examined the reproducibility and durability of added hypoxic exposure in a feasible health program of several months. Methods: 32 obese persons, randomly assigned to either a hypoxia (age 50.3 ± 10.3 years, BMI 37.9 ± 8.1 kg/m² or a normoxia (age 52.4 ± 7.9 years, BMI 36.3 ± 4.0 kg/m² group, completed 52 exercise sessions within 8 months. Participants exercised for 90 min (65-70% HRpeak either at a simulated altitude of 3,500 m or in normoxia, and rested for further 90 min at 4,500 m or normoxia. Before, after 5 weeks, after 3 months, and after the intervention, body composition and exercise capacity were determined. Risk markers (e.g., blood pressure, cholesterol were measured before, after 3 months, and after the intervention period. Results: Body weight, BMI, waist and hip circumference, Ppeak and BPsys improved over time (p Conclusion: Long-term, moderate intensity exercise and rest in hypoxia does not lead to higher reductions in body weight than normoxia alone. Therefore, for weight loss and metabolic markers hypoxic exposure does not add effects at least when stimuli (i.e., hypoxia dose, exercise intensity/duration are unaltered throughout the intervention.

  10. Optimal Feature Extraction Using Greedy Approach for Random Image Components and Subspace Approach in Face Recognition

    Institute of Scientific and Technical Information of China (English)

    Mathu Soothana S.Kumar Retna Swami; Muneeswaran Karuppiah

    2013-01-01

    An innovative and uniform framework based on a combination of Gabor wavelets with principal component analysis (PCA) and multiple discriminant analysis (MDA) is presented in this paper.In this framework,features are extracted from the optimal random image components using greedy approach.These feature vectors are then projected to subspaces for dimensionality reduction which is used for solving linear problems.The design of Gabor filters,PCA and MDA are crucial processes used for facial feature extraction.The FERET,ORL and YALE face databases are used to generate the results.Experiments show that optimal random image component selection (ORICS) plus MDA outperforms ORICS and subspace projection approach such as ORICS plus PCA.Our method achieves 96.25%,99.44% and 100% recognition accuracy on the FERET,ORL and YALE databases for 30% training respectively.This is a considerably improved performance compared with other standard methodologies described in the literature.

  11. Quasi optimal and adaptive sparse grids with control variates for PDEs with random diffusion coefficient

    KAUST Repository

    Tamellini, Lorenzo

    2016-01-05

    In this talk we discuss possible strategies to minimize the impact of the curse of dimensionality effect when building sparse-grid approximations of a multivariate function u = u(y1, ..., yN ). More precisely, we present a knapsack approach , in which we estimate the cost and the error reduction contribution of each possible component of the sparse grid, and then we choose the components with the highest error reduction /cost ratio. The estimates of the error reduction are obtained by either a mixed a-priori / a-posteriori approach, in which we first derive a theoretical bound and then tune it with some inexpensive auxiliary computations (resulting in the so-called quasi-optimal sparse grids ), or by a fully a-posteriori approach (obtaining the so-called adaptive sparse grids ). This framework is very general and can be used to build quasi-optimal/adaptive sparse grids on bounded and unbounded domains (e.g. u depending on uniform and normal random distributions for yn), using both nested and non-nested families of univariate collocation points. We present some theoretical convergence results as well as numerical results showing the efficiency of the proposed approach for the approximation of the solution of elliptic PDEs with random diffusion coefficients. In this context, to treat the case of rough permeability fields in which a sparse grid approach may not be suitable, we propose to use the sparse grids as a control variate in a Monte Carlo simulation.

  12. Second-line Erlotinib or Intermittent Erlotinib plus Docetaxel in Male Ex-smokers with Squamous NSCLC: The TALISMAN Randomized Trial.

    Science.gov (United States)

    Gridelli, Cesare; Chella, Antonio; Valmadre, Giuseppe; Allegrini, Giacomo; Brighenti, Matteo; Bidoli, Paolo; Rossi, Antonio; Maione, Paolo; Migliorino, Maria Rita; Ricciardi, Serena; DE Marinis, Filippo

    2016-12-01

    The TArceva and docetaxeL In former-Smokers MAle patients with recurrent non-small cell lung cancer (TALISMAN) phase II, open-label randomized trial evaluates the combination of erlotinib with docetaxel in the second-line therapy of ex-smoker males with advanced squamous non-small cell lung cancer (NSCLC). Patients received erlotinib 150 mg/day (arm A; n=36) or docetaxel 75 mg/m(2) on day 1 of each 3-week cycle and erlotinib 150 mg/day on days 2-16 of each cycle (arm B; n=38). The primary end-point was progression-free rate (PFR) at 6 months. The study was prematurely interrupted due to slow enrolment. Three (8.3%) patients in arm A and 3 (8.1%) in arm B remained progression-free at 6 months. Median progression-free survival (PFS) was 2.3 months in arm A and 2.8 months in arm B. Median overall survival (OS) was 5.6 and 8.9 months, respectively. Overall, 77.8% of patients in arm A and 89.2% in arm B experienced treatment-related adverse events (AEs). Results do not support further investigation of the combination of erlotinib and docetaxel in this setting. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  13. Reliability based multiobjective optimization for design of structures subject to random vibrations

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Based on a multiobjective approach whose objective function (OF) vector collects stochastic reliability performance and structural cost indices, a structural optimization criterion for mechanical systems subject to random vibrations is presented for supporting engineer's design. This criterion differs from the most commonly used conventional optimum design criterion for random vibrating structure, which is based on minimizing displacement or acceleration variance of main structure responses,without considering explicitly required performances against failure. The proposed criterion can properly take into account the design-reliability required performances, and it becomes a more efficient support for structural engineering decision making. The multiobjective optimum (MOO) design of a tuned mass damper (TMD) has been developed in a typical seismic design problem, to control structural vibration induced on a multi-storey building structure excited by nonstationary base acceleration random process.A numerical example for a three-storey building is developed and a sensitivity analysis is carried out. The results are shown in a useful manner for TMD design decision support.

  14. Dispatching Plan Based on Route Optimization Model Considering Random Wind for Aviation Emergency Rescue

    Directory of Open Access Journals (Sweden)

    Ming Zhang

    2016-01-01

    Full Text Available Aviation emergency rescue is an effective means of nature disaster relief that is widely used in many countries. The dispatching plan of aviation emergency rescue guarantees the efficient implementation of this relief measure. The conventional dispatching plan that does not consider random wind factors leads to a nonprecise quick-responsive scheme and serious safety issues. In this study, an aviation emergency rescue framework that considers the influence of random wind at flight trajectory is proposed. In this framework, the predicted wind information for a disaster area is updated by using unscented Kalman filtering technology. Then, considering the practical scheduling problem of aircraft emergency rescue at present, a multiobjective model is established in this study. An optimization model aimed at maximizing the relief supply satisfaction, rescue priority satisfaction, and minimizing total rescue flight distance is formulated. Finally, the transport times of aircraft with and without the influence of random wind are analyzed on the basis of the data of an earthquake disaster area. Results show that the proposed dispatching plan that considers the constraints of updated wind speed and direction is highly applicable in real operations.

  15. A Novel Path Planning for Robots Based on Rapidly-Exploring Random Tree and Particle Swarm Optimizer Algorithm

    Directory of Open Access Journals (Sweden)

    Zhou Feng

    2013-09-01

    Full Text Available A based on Rapidly-exploring Random Tree(RRT and Particle Swarm Optimizer (PSO for path planning of the robot is proposed.First the grid method is built to describe the working space of the mobile robot,then the Rapidly-exploring Random Tree algorithm is used to obtain the global navigation path,and the Particle Swarm Optimizer algorithm is adopted to get the better path.Computer experiment results demonstrate that this novel algorithm can plan an optimal path rapidly in a cluttered environment.The successful obstacle avoidance is achieved,and the model is robust and performs reliably.

  16. Optimizing LED lighting for space plant growth unit: Joint effects of photon flux density, red to white ratios and intermittent light pulses

    Science.gov (United States)

    Avercheva, O. V.; Berkovich, Yu. A.; Konovalova, I. O.; Radchenko, S. G.; Lapach, S. N.; Bassarskaya, E. M.; Kochetova, G. V.; Zhigalova, T. V.; Yakovleva, O. S.; Tarakanov, I. G.

    2016-11-01

    The aim of this work were to choose a quantitative optimality criterion for estimating the quality of plant LED lighting regimes inside space greenhouses and to construct regression models of crop productivity and the optimality criterion depending on the level of photosynthetic photon flux density (PPFD), the proportion of the red component in the light spectrum and the duration of the duty cycle (Chinese cabbage Brassica сhinensis L. as an example). The properties of the obtained models were described in the context of predicting crop dry weight and the optimality criterion behavior when varying plant lighting parameters. Results of the fractional 3-factor experiment demonstrated the share of the PPFD level participation in the crop dry weight accumulation was 84.4% at almost any combination of other lighting parameters, but when PPFD value increased up to 500 μmol m-2 s-1 the pulse light and supplemental light from red LEDs could additionally increase crop productivity. Analysis of the optimality criterion response to variation of lighting parameters showed that the maximum coordinates were the following: PPFD = 500 μmol m-2 s-1, about 70%-proportion of the red component of the light spectrum (PPFDLEDred/PPFDLEDwhite = 1.5) and the duty cycle with a period of 501 μs. Thus, LED crop lighting with these parameters was optimal for achieving high crop productivity and for efficient use of energy in the given range of lighting parameter values.

  17. Optimal Multi-Server Allocation to Parallel Queues With Independent Random Queue-Server Connectivity

    CERN Document Server

    Al-Zubaidy, Hussein; Viniotis, Yannis

    2011-01-01

    We investigate an optimal scheduling problem in a discrete-time system of L parallel queues that are served by K identical, randomly connected servers. Each queue may be connected to a subset of the K servers during any given time slot. This model has been widely used in studies of emerging 3G/4G wireless systems. We introduce the class of Most Balancing (MB) policies and provide their mathematical characterization. We prove that MB policies are optimal; we de?ne optimality as minimization, in stochastic ordering sense, of a range of cost functions of the queue lengths, including the process of total number of packets in the system. We use stochastic coupling arguments for our proof. We introduce the Least Connected Server First/Longest Connected Queue (LCSF/LCQ) policy as an easy-to-implement approximation of MB policies. We conduct a simulation study to compare the performance of several policies. The simulation results show that: (a) in all cases, LCSF/LCQ approximations to the MB policies outperform the o...

  18. Land cover classification using random forest with genetic algorithm-based parameter optimization

    Science.gov (United States)

    Ming, Dongping; Zhou, Tianning; Wang, Min; Tan, Tian

    2016-07-01

    Land cover classification based on remote sensing imagery is an important means to monitor, evaluate, and manage land resources. However, it requires robust classification methods that allow accurate mapping of complex land cover categories. Random forest (RF) is a powerful machine-learning classifier that can be used in land remote sensing. However, two important parameters of RF classification, namely, the number of trees and the number of variables tried at each split, affect classification accuracy. Thus, optimal parameter selection is an inevitable problem in RF-based image classification. This study uses the genetic algorithm (GA) to optimize the two parameters of RF to produce optimal land cover classification accuracy. HJ-1B CCD2 image data are used to classify six different land cover categories in Changping, Beijing, China. Experimental results show that GA-RF can avoid arbitrariness in the selection of parameters. The experiments also compare land cover classification results by using GA-RF method, traditional RF method (with default parameters), and support vector machine method. When the GA-RF method is used, classification accuracies, respectively, improved by 1.02% and 6.64%. The comparison results show that GA-RF is a feasible solution for land cover classification without compromising accuracy or incurring excessive time.

  19. Assessment of subjective and hemodynamic tolerance of different high- and low-flux dialysis membranes in patients undergoing chronic intermittent hemodialysis: a randomized controlled trial.

    Science.gov (United States)

    Bianchi, Giorgia; Salvadé, Vanja; Lucchini, Barbara; Schätti-Stählin, Sibylle; Salvadé, Igor; Burnier, Michel; Gabutti, Luca

    2014-10-01

    Clinical experience and experimental data suggest that intradialytic hemodynamic profiles could be influenced by the characteristics of the dialysis membranes. Even within the worldwide used polysulfone family, intolerance to specific membranes was occasionally evoked. The aim of this study was to compare hemodynamically some of the commonly used polysulfone dialyzers in Switzerland. We performed an open-label, randomized, cross-over trial, including 25 hemodialysis patients. Four polysulfone dialyzers, A (Revaclear high-flux, Gambro, Stockholm, Sweden), B (Helixone high-flux, Fresenius), C (Xevonta high-flux, BBraun, Melsungen, Germany), and D (Helixone low-flux, Fresenius, Bad Homburg vor der Höhe, Germany), were compared. The hemodynamic profile was assessed and patients were asked to provide tolerance feedback. The mean score (±SD) subjectively assigned to dialysis quality on a 1-10 scale was A 8.4 ± 1.3, B 8.6 ± 1.3, C 8.5 ± 1.6, D 8.5 ± 1.5. Kt/V was A 1.58 ± 0.30, B 1.67 ± 0.33, C 1.62 ± 0.32, D 1.45 ± 0.31. The low- compared with the high-flux membranes, correlated to higher systolic (128.1 ± 13.1 vs. 125.6 ± 12.1 mmHg, P mmHg; P mmHg/mL; P 20 mmHg) were 70 with A, 87 with B, 73 with C, and 75 with D (P < 0.01 B vs. A, 0.05 B vs. C and 0.07 B vs. D). The low-flux membrane correlated to higher blood pressure levels compared with the high-flux ones. The Helixone high-flux membrane ensured the best efficiency. Unfortunately, the very same dialyzer correlated to a higher incidence of hypotensive episodes.

  20. Optimizing LED lighting for space plant growth unit: Joint effects of photon flux density, red to white ratios and intermittent light pulses.

    Science.gov (United States)

    Avercheva, O V; Berkovich, Yu A; Konovalova, I O; Radchenko, S G; Lapach, S N; Bassarskaya, E M; Kochetova, G V; Zhigalova, T V; Yakovleva, O S; Tarakanov, I G

    2016-11-01

    The aim of this work were to choose a quantitative optimality criterion for estimating the quality of plant LED lighting regimes inside space greenhouses and to construct regression models of crop productivity and the optimality criterion depending on the level of photosynthetic photon flux density (PPFD), the proportion of the red component in the light spectrum and the duration of the duty cycle (Chinese cabbage Brassica сhinensis L. as an example). The properties of the obtained models were described in the context of predicting crop dry weight and the optimality criterion behavior when varying plant lighting parameters. Results of the fractional 3-factor experiment demonstrated the share of the PPFD level participation in the crop dry weight accumulation was 84.4% at almost any combination of other lighting parameters, but when PPFD value increased up to 500µmol m(-2)s(-1) the pulse light and supplemental light from red LEDs could additionally increase crop productivity. Analysis of the optimality criterion response to variation of lighting parameters showed that the maximum coordinates were the following: PPFD = 500µmol m(-2)s(-1), about 70%-proportion of the red component of the light spectrum (PPFDLEDred/PPFDLEDwhite = 1.5) and the duty cycle with a period of 501µs. Thus, LED crop lighting with these parameters was optimal for achieving high crop productivity and for efficient use of energy in the given range of lighting parameter values. Copyright © 2016 The Committee on Space Research (COSPAR). Published by Elsevier Ltd. All rights reserved.

  1. Intermittency and exotic channels

    CERN Document Server

    Bialas, A

    1994-01-01

    It is pointed out that accurate measurements of short-range two-particle correlations in like-charge K\\pi and in \\pi^ 0\\pi^ 0 channels should be very helpful in determining the origin of the \\lq\\lq intermittency\\rq\\rq\\ phenomenon observed recently for the like-charge pion pairs.

  2. Time-delayed feedback control optimization for quasi linear systems under random excitations

    Institute of Scientific and Technical Information of China (English)

    Xueping Li; Detain Wei; Weiqiu Zhu

    2009-01-01

    A strategy for time-delayed feedback control optimization of quasi linear systems with random excita-tion is proposed. First, the stochastic averaging method is used to reduce the dimension of the state space and to derive the stationary response of the system. Secondly, the control law is assumed to be velocity feedback control with time delay and the unknown control gains are determined by the performance indices. The response of the controlled system is predicted through solving the Fokker-Plank-Kolmogorov equation associated with the averaged It6 equation. Finally, numerical examples are used to illustrate the proposed con-trol method, and the numerical results are confirmed by Monte Carlo simulation.

  3. Statistical inference for response adaptive randomization procedures with adjusted optimal allocation proportions.

    Science.gov (United States)

    Zhu, Hongjian

    2016-12-12

    Seamless phase II/III clinical trials have attracted increasing attention recently. They mainly use Bayesian response adaptive randomization (RAR) designs. There has been little research into seamless clinical trials using frequentist RAR designs because of the difficulty in performing valid statistical inference following this procedure. The well-designed frequentist RAR designs can target theoretically optimal allocation proportions, and they have explicit asymptotic results. In this paper, we study the asymptotic properties of frequentist RAR designs with adjusted target allocation proportions, and investigate statistical inference for this procedure. The properties of the proposed design provide an important theoretical foundation for advanced seamless clinical trials. Our numerical studies demonstrate that the design is ethical and efficient.

  4. Optimal Control of a Surge-Mode WEC in Random Waves

    Energy Technology Data Exchange (ETDEWEB)

    Chertok, Allan [Resolute Marine Energy, Inc., Boston, MA (United States); Ceberio, Olivier [Resolute Marine Energy, Inc., Boston, MA (United States); Staby, Bill [Resolute Marine Energy, Inc., Boston, MA (United States); Previsic, Mirko [Re Vision Consulting, Sacramento, CA (United States); Scruggs, Jeffrey [Univ. of Michigan, Ann Arbor, MI (United States); Van de Ven, James [Univ. of Minnesota, Minneapolis, MN (United States)

    2016-08-30

    The objective of this project was to develop one or more real-time feedback and feed-forward (MPC) control algorithms for an Oscillating Surge Wave Converter (OSWC) developed by RME called SurgeWEC™ that leverages recent innovations in wave energy converter (WEC) control theory to maximize power production in random wave environments. The control algorithms synthesized innovations in dynamic programming and nonlinear wave dynamics using anticipatory wave sensors and localized sensor measurements; e.g. position and velocity of the WEC Power Take Off (PTO), with predictive wave forecasting data. The result was an advanced control system that uses feedback or feed-forward data from an array of sensor channels comprised of both localized and deployed sensors fused into a single decision process that optimally compensates for uncertainties in the system dynamics, wave forecasts, and sensor measurement errors.

  5. Optimization of random PEGylation reactions by means of high throughput screening.

    Science.gov (United States)

    Maiser, Benjamin; Dismer, Florian; Hubbuch, Jürgen

    2014-01-01

    Since the first FDA approval of a PEGylated product in 1990, so called random PEGylation reactions are still used to increase the efficacy of biopharmaceuticals and represent the major technology of all approved PEG-modified drugs. However, the great influence of process parameters on PEGylation degree and the PEG-binding site results in a lack of reaction specificity which can have severe impact on the product profile. Consequently, reproducible and well characterized processes are essential to meet increasing regulative requirements resulting from the quality-by-design (QbD) initiative, especially for this kind of modification type. In this study we present a general approach which combines the simple chemistry of random PEGylation reactions with high throughput experimentation (HTE) to achieve a well-defined process. Robotic based batch experiments have been established in a 96-well plate format and were analyzed to investigate the influence of different PEGylation conditions for lysozyme as model protein. With common SEC analytics highly reproducible reaction kinetics were measured and a significant influence of PEG-excess, buffer pH, and reaction time could be investigated. Additional mono-PEG-lysozyme analytics showed the impact of varying buffer pH on the isoform distribution, which allowed us to identify optimal process parameters to get a maximum concentration of each isoform. Employing Micrococcus lysodeikticus based activity assays, PEG-lysozyme33 was identified to be the isoform with the highest residual activity, followed by PEG-lysozyme1 . Based on these results, a control space for a PEGylation reaction was defined with respect to an optimal overall volumetric activity of mono-PEG-lysozyme isoform mixtures.

  6. The Sexunzipped trial: optimizing the design of online randomized controlled trials.

    Science.gov (United States)

    Bailey, Julia V; Pavlou, Menelaos; Copas, Andrew; McCarthy, Ona; Carswell, Ken; Rait, Greta; Hart, Graham; Nazareth, Irwin; Free, Caroline; French, Rebecca; Murray, Elizabeth

    2013-12-11

    outcomes and 47.4% (118/249) for return of chlamydia urine samples by post. It was quick and efficient to recruit young people to this online trial. Our procedures for obtaining online consent, verifying participant identity, automated randomization, and concealment of allocation worked well. The optimal response rate for the online sexual health outcome measurement was comparable to face-to-face trials. Multiple methods of participant contact, requesting online data only, and higher value compensation increased trial retention at 3-month follow-up. International Standard Randomized Controlled Trial Number (ISRCTN): 55651027; http://www.controlled-trials.com/ISRCTN55651027 (Archived by WebCite at http://www.webcitation.org/6LbkxdPKf).

  7. MATHEMATICAL MODEL OF OPTIMAL PROJECT PORTFOLIO FORMING BASED ON RANDOM FACTORS

    Directory of Open Access Journals (Sweden)

    I. A. Korkhina

    2014-03-01

    Full Text Available Purpose. To identify the ways of perspective development for railway transport one should solve the problem of forming the investment project portfolio. Thus, it is necessary to deal with uncertainty in the input data (prices of services, materials, energy products. To take into account this uncertainty it is proposed to use the developed model of stochastic programming. Methodology. For accounting of uncertain data the probabilistic limits on the quantities of resources, which are used in the project portfolio are imposed. As the objective function it is proposed to maximize the threshold, which with a given probability may exceed the planning interval of the net income. Findings. Stochastic programming model with line-by-line probabilistic constraints was obtained. Coefficients of this model are normally distributed random variables. Ratios, which allow calculating mathematical expectations and covariance matrices of these coefficients, were concluded. Originality. Known methods of forming the optimal project portfolio are based on the fact that all inputs are known exactly. On the basis of this consideration, the authors of works on the creating an optimal project portfolio have come to a scheme of deterministic mathematical programming. In this article we propose to take into account the uncertainty in the input data, which will increase the reliability of the portfolio effectiveness estimation through the use of stochastic mathematical programming scheme. Practical value. The developed model can be used in order to solve the planning problems of railway transport development.

  8. Regionalization of patterns of flow intermittence from gauging station records

    Science.gov (United States)

    Snelder, T. H.; Datry, T.; Lamouroux, N.; Larned, S. T.; Sauquet, E.; Pella, H.; Catalogne, C.

    2013-07-01

    Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow) in each year of record (FREQ; yr-1), and the total number of zero-flow days in each year of record (DUR; days). These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr-1), and the mean duration of zero-flow periods (mDUR; days). Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR) and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF) models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35). Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also catchment area, shape

  9. Overall instability and optimization of bar structures with random defects in case of constraints on faultless operation probability

    Directory of Open Access Journals (Sweden)

    O.A. Sergeyev

    2013-12-01

    Full Text Available The aim of this paper is to pose and solve weight optimization problem of bar structures with constraints on faultless operation probability of a structure and constraints on design variables. Optimization method is based on a quadratic approximation of the objective function and a linear approximation of constraints on faultless operation probability of rod structures with random defects. In this paper, the initial global imperfections are considered as small independent random variables distributed according to normal law, and buckling load value is also a random variable. We study a case when under random imperfections non-multiple buckling load value is changed and non-multiple critical point type – the limit point is not changed.

  10. A cloud theory-based particle swarm optimization for multiple decision maker vehicle routing problems with fuzzy random time windows

    Science.gov (United States)

    Ma, Yanfang; Xu, Jiuping

    2015-06-01

    This article puts forward a cloud theory-based particle swarm optimization (CTPSO) algorithm for solving a variant of the vehicle routing problem, namely a multiple decision maker vehicle routing problem with fuzzy random time windows (MDVRPFRTW). A new mathematical model is developed for the proposed problem in which fuzzy random theory is used to describe the time windows and bi-level programming is applied to describe the relationship between the multiple decision makers. To solve the problem, a cloud theory-based particle swarm optimization (CTPSO) is proposed. More specifically, this approach makes improvements in initialization, inertia weight and particle updates to overcome the shortcomings of the basic particle swarm optimization (PSO). Parameter tests and results analysis are presented to highlight the performance of the optimization method, and comparison of the algorithm with the basic PSO and the genetic algorithm demonstrates its efficiency.

  11. Fate in intermittent claudication

    DEFF Research Database (Denmark)

    Jelnes, Rolf; Gaardsting, O; Hougaard Jensen, K

    1986-01-01

    The fate of 257 consecutive patients (100 women) aged 36-85 years (mean 65) first seen with intermittent claudication in 1977 was analysed after a mean of 6.5 (SD 0.5) years. When first seen none of the patients complained of rest pain or had ulcers or gangrenous lesions on the feet. At follow up....... The rate of clinical progression of the arteriosclerotic disease (that is, rest pain or gangrene) of the worst affected leg was 7.5% in the first year after referral. Thereafter the rate was 2.2% a year. An ankle systolic blood pressure below 70 mm Hg, a toe systolic blood pressure below 40 mm Hg......, or an ankle/arm pressure index below 50% were individually significantly associated with progression of the arteriosclerotic disease. These findings show the importance of peripheral blood pressure measurements in the management of patients with intermittent claudication due to arteriosclerotic disease....

  12. Feigning Acute Intermittent Porphyria

    Directory of Open Access Journals (Sweden)

    Rania Elkhatib

    2014-01-01

    Full Text Available Acute intermittent porphyria (AIP is an autosomal dominant genetic defect in heme synthesis. Patients with this illness can have episodic life-threatening attacks characterized by abdominal pain, neurological deficits, and psychiatric symptoms. Feigning this illness has not been reported in the English language literature to date. Here, we report on a patient who presented to the hospital with an acute attack of porphyria requesting opiates. Diligent assessment of extensive prior treatment records revealed thirteen negative tests for AIP.

  13. Optimized rapeseed oil enriched with healthy micronutrients: a relevant nutritional approach to prevent cardiovascular diseases. Results of the Optim'Oils randomized intervention trial.

    Science.gov (United States)

    Gladine, Cécile; Combe, Nicole; Vaysse, Carole; Pereira, Bruno; Huertas, Alain; Salvati, Serafina; Rossignol-Castera, Anne; Cano, Noël; Chardigny, Jean-Michel

    2013-03-01

    Rapeseeds are naturally rich in cardioprotective micronutrients but refining leads to substantial losses or the production of undesirable compounds. The Optim'Oils European project proposed innovative refining conditions to produce an optimized rapeseed oil enriched in micronutrients and low in trans linolenic acid. We aimed to investigate cardioprotective properties of this Optimized oil. In a randomized, double-blind, controlled, cross-over study, 59 healthy normolipidaemic men consumed either Optimized or Standard rapeseed oils (20 g/d) and margarines (22 g/d) for 3 weeks. The Optimized oil reduced the trans FA concentration (p=0.009) and increased the contents of alpha-tocopherol (p=0.022) and coenzyme Q10 (poil. Over the 3-week trial, Total-/HDL-cholesterol and LDL-/HDL-cholesterol were increased by 4% (poil consumption whereas none of them rose with the Optimized rapeseed oil which increased the HDL-cholesterol and ApoA1 plasma content (+2%, NS and +3%, prapeseed oil. Finally, the Optimized oil reduced the plasma content of LDLox (-6%, NS), this effect being significantly different from the Standard oil (p=0.050). In conclusion, reasonable intake of an Optimized rapeseed oil resulting from innovative refining processes and enriched in cardioprotective micronutrients represent a relevant nutritional approach to prevent the risk of cardiovascular diseases by improving the cholesterol profile and reducing LDL oxidation.

  14. Optimization of the Dutch Matrix Test by Random Selection of Sentences From a Preselected Subset

    Directory of Open Access Journals (Sweden)

    Rolph Houben

    2015-04-01

    Full Text Available Matrix tests are available for speech recognition testing in many languages. For an accurate measurement, a steep psychometric function of the speech materials is required. For existing tests, it would be beneficial if it were possible to further optimize the available materials by increasing the function’s steepness. The objective is to show if the steepness of the psychometric function of an existing matrix test can be increased by selecting a homogeneous subset of recordings with the steepest sentence-based psychometric functions. We took data from a previous multicenter evaluation of the Dutch matrix test (45 normal-hearing listeners. Based on half of the data set, first the sentences (140 out of 311 with a similar speech reception threshold and with the steepest psychometric function (≥9.7%/dB were selected. Subsequently, the steepness of the psychometric function for this selection was calculated from the remaining (unused second half of the data set. The calculation showed that the slope increased from 10.2%/dB to 13.7%/dB. The resulting subset did not allow the construction of enough balanced test lists. Therefore, the measurement procedure was changed to randomly select the sentences during testing. Random selection may interfere with a representative occurrence of phonemes. However, in our material, the median phonemic occurrence remained close to that of the original test. This finding indicates that phonemic occurrence is not a critical factor. The work highlights the possibility that existing speech tests might be improved by selecting sentences with a steep psychometric function.

  15. Optimization of the Dutch matrix test by random selection of sentences from a preselected subset.

    Science.gov (United States)

    Houben, Rolph; Dreschler, Wouter A

    2015-05-11

    Matrix tests are available for speech recognition testing in many languages. For an accurate measurement, a steep psychometric function of the speech materials is required. For existing tests, it would be beneficial if it were possible to further optimize the available materials by increasing the function's steepness. The objective is to show if the steepness of the psychometric function of an existing matrix test can be increased by selecting a homogeneous subset of recordings with the steepest sentence-based psychometric functions. We took data from a previous multicenter evaluation of the Dutch matrix test (45 normal-hearing listeners). Based on half of the data set, first the sentences (140 out of 311) with a similar speech reception threshold and with the steepest psychometric function (≥9.7%/dB) were selected. Subsequently, the steepness of the psychometric function for this selection was calculated from the remaining (unused) second half of the data set. The calculation showed that the slope increased from 10.2%/dB to 13.7%/dB. The resulting subset did not allow the construction of enough balanced test lists. Therefore, the measurement procedure was changed to randomly select the sentences during testing. Random selection may interfere with a representative occurrence of phonemes. However, in our material, the median phonemic occurrence remained close to that of the original test. This finding indicates that phonemic occurrence is not a critical factor. The work highlights the possibility that existing speech tests might be improved by selecting sentences with a steep psychometric function.

  16. Tuning of an optimal fuzzy PID controller with stochastic algorithms for networked control systems with random time delay.

    Science.gov (United States)

    Pan, Indranil; Das, Saptarshi; Gupta, Amitava

    2011-01-01

    An optimal PID and an optimal fuzzy PID have been tuned by minimizing the Integral of Time multiplied Absolute Error (ITAE) and squared controller output for a networked control system (NCS). The tuning is attempted for a higher order and a time delay system using two stochastic algorithms viz. the Genetic Algorithm (GA) and two variants of Particle Swarm Optimization (PSO) and the closed loop performances are compared. The paper shows that random variation in network delay can be handled efficiently with fuzzy logic based PID controllers over conventional PID controllers.

  17. CURE-SMOTE algorithm and hybrid algorithm for feature selection and parameter optimization based on random forests.

    Science.gov (United States)

    Ma, Li; Fan, Suohai

    2017-03-14

    The random forests algorithm is a type of classifier with prominent universality, a wide application range, and robustness for avoiding overfitting. But there are still some drawbacks to random forests. Therefore, to improve the performance of random forests, this paper seeks to improve imbalanced data processing, feature selection and parameter optimization. We propose the CURE-SMOTE algorithm for the imbalanced data classification problem. Experiments on imbalanced UCI data reveal that the combination of Clustering Using Representatives (CURE) enhances the original synthetic minority oversampling technique (SMOTE) algorithms effectively compared with the classification results on the original data using random sampling, Borderline-SMOTE1, safe-level SMOTE, C-SMOTE, and k-means-SMOTE. Additionally, the hybrid RF (random forests) algorithm has been proposed for feature selection and parameter optimization, which uses the minimum out of bag (OOB) data error as its objective function. Simulation results on binary and higher-dimensional data indicate that the proposed hybrid RF algorithms, hybrid genetic-random forests algorithm, hybrid particle swarm-random forests algorithm and hybrid fish swarm-random forests algorithm can achieve the minimum OOB error and show the best generalization ability. The training set produced from the proposed CURE-SMOTE algorithm is closer to the original data distribution because it contains minimal noise. Thus, better classification results are produced from this feasible and effective algorithm. Moreover, the hybrid algorithm's F-value, G-mean, AUC and OOB scores demonstrate that they surpass the performance of the original RF algorithm. Hence, this hybrid algorithm provides a new way to perform feature selection and parameter optimization.

  18. A Fast Reactive Power Optimization in Distribution Network Based on Large Random Matrix Theory and Data Analysis

    Directory of Open Access Journals (Sweden)

    Wanxing Sheng

    2016-05-01

    Full Text Available In this paper, a reactive power optimization method based on historical data is investigated to solve the dynamic reactive power optimization problem in distribution network. In order to reflect the variation of loads, network loads are represented in a form of random matrix. Load similarity (LS is defined to measure the degree of similarity between the loads in different days and the calculation method of the load similarity of load random matrix (LRM is presented. By calculating the load similarity between the forecasting random matrix and the random matrix of historical load, the historical reactive power optimization dispatching scheme that most matches the forecasting load can be found for reactive power control usage. The differences of daily load curves between working days and weekends in different seasons are considered in the proposed method. The proposed method is tested on a standard 14 nodes distribution network with three different types of load. The computational result demonstrates that the proposed method for reactive power optimization is fast, feasible and effective in distribution network.

  19. Comparison of Clenshaw–Curtis and Leja Quasi-Optimal Sparse Grids for the Approximation of Random PDEs

    KAUST Repository

    Nobile, Fabio

    2015-11-26

    In this work we compare different families of nested quadrature points, i.e. the classic Clenshaw–Curtis and various kinds of Leja points, in the context of the quasi-optimal sparse grid approximation of random elliptic PDEs. Numerical evidence suggests that both families perform comparably within such framework.

  20. Manual complementariness optimization of electrical source involving intermittent power%含间歇性电源的发电资源互补优化研究

    Institute of Scientific and Technical Information of China (English)

    李洪美; 罗建裕; 万秋兰

    2013-01-01

    In order to maximize the usage of renewable generation, compensate its fluctuation and acquire a continuous and smooth output, this paper defines two indices. Complementary degree is defined for measuring the natural complementary characteristics of the stochastic generations, and smoothness is defined for measuring the effect of manual complementariness between adjustable and stochastic generations. These two indices are employed to study the natural complementary characteristic involving wind power and PV, and the manual complementariness involving wind power, PV and energy storage system, respectively. Finally, analyses of two indices are synthesized to form a complementary strategy. This study is a guidance to determine the ratio of stochastic generations and the capacity configuration of adjustable generations as well as a good reference for optimizing the size of ESS in this site. This work is supported by National High-tech Research and Development Program of China (863 Program) (No. 2011AA05A105).%  为最大限度实现可再生资源的合理利用和有效平缓可再生能源的波动性,实现发电的连续性和平滑性,定义了不可调资源之间的自然互补特性的定量评价指标——互补率:定义了可调资源和不可调资源之间的人工互补特性的定量评价指标——平滑度。应用互补率和平滑度指标分别研究了风、光的自然互补特性和风、光、储的人工互补特性。综合利用上述两个指标进行了含间歇性电源的发电资源互补优化策略研究。研究结果表明,互补率和平滑性指标提供了不可调资源容量的配比和可调资源的配置容量的定量分析方法,可实现含间歇性电源的发电资源综合互补优化。

  1. Impact of Markov Random Field Optimizer on MRI-based Tissue Segmentation in the Aging Brain

    Science.gov (United States)

    Schwarz, Christopher G.; Tsui, Alex; Fletcher, Evan; Singh, Baljeet; DeCarli, Charles; Carmichael, Owen

    2013-01-01

    Automatically segmenting brain magnetic resonance images into grey matter, white matter, and cerebrospinal fluid compartments is a fundamentally important neuroimaging problem whose difficulty is heightened in the presence of aging and neurodegenerative disease. Current methods overlap greatly in terms of identifiable algorithmic components, and the impact of specific components on performance is generally unclear in important real-world scenarios involving serial scanning, multiple scanners, and neurodegenerative disease. Therefore we evaluated the impact that one such component, the Markov Random Field (MRF) optimizer that encourages spatially-smooth tissue labelings, has on brain tissue segmentation performance. Two challenging elderly sets were used to test segmentation consistency across scanners and biological plausibility of tissue change estimates; and a simulated young brain data set was used to test accuracy against ground truth. Comparisons among Graph Cuts (GC), Belief Propagation (BP), and Iterative Conditional Modes (ICM) suggested that in the elderly brain, BP and GC provide the highest segmentation performance, with a slight advantage to BP, and that performance is often superior to that provided by popular methods SPM and FAST. Conversely, SPM and FAST excelled in the young brain, thus emphasizing the unique challenges involved in imaging the aging brain. PMID:22256150

  2. Randomly organized lipids and marginally stable proteins: a coupling of weak interactions to optimize membrane signaling.

    Science.gov (United States)

    Rice, Anne M; Mahling, Ryan; Fealey, Michael E; Rannikko, Anika; Dunleavy, Katie; Hendrickson, Troy; Lohese, K Jean; Kruggel, Spencer; Heiling, Hillary; Harren, Daniel; Sutton, R Bryan; Pastor, John; Hinderliter, Anne

    2014-09-01

    Eukaryotic lipids in a bilayer are dominated by weak cooperative interactions. These interactions impart highly dynamic and pliable properties to the membrane. C2 domain-containing proteins in the membrane also interact weakly and cooperatively giving rise to a high degree of conformational plasticity. We propose that this feature of weak energetics and plasticity shared by lipids and C2 domain-containing proteins enhance a cell's ability to transduce information across the membrane. We explored this hypothesis using information theory to assess the information storage capacity of model and mast cell membranes, as well as differential scanning calorimetry, carboxyfluorescein release assays, and tryptophan fluorescence to assess protein and membrane stability. The distribution of lipids in mast cell membranes encoded 5.6-5.8bits of information. More information resided in the acyl chains than the head groups and in the inner leaflet of the plasma membrane than the outer leaflet. When the lipid composition and information content of model membranes were varied, the associated C2 domains underwent large changes in stability and denaturation profile. The C2 domain-containing proteins are therefore acutely sensitive to the composition and information content of their associated lipids. Together, these findings suggest that the maximum flow of signaling information through the membrane and into the cell is optimized by the cooperation of near-random distributions of membrane lipids and proteins. This article is part of a Special Issue entitled: Interfacially Active Peptides and Proteins. Guest Editors: William C. Wimley and Kalina Hristova.

  3. Optimal performance of NdAl3(BO3)4 nanocrystals random lasers

    Science.gov (United States)

    Moura, André L.; Maia, Lauro J. Q.; Gomes, Anderson S. L.; de Araújo, Cid B.

    2016-12-01

    Resonant pumping associated with the influence of the quantum-defect between the excitation and the emitted laser photons allow optimal performance of neodymium ions (Nd3+) based random lasers (RLs), as demonstrated here for the first time. The RL emission at 1063.5 nm due to the Nd3+ transition 4F3/2 → 4I11/2 in a powder consisting of NdAl3(BO3)4 nanocrystals, was investigated by exciting the powder at 690 nm, 750 nm, 810 nm, and 884 nm in resonance with the Nd3+ transitions from the ground state (4I9/2) to the 4F9/2, {4F7/2,4S3/2}, {4F5/2,4H9/2}, and 4F3/2 states, respectively. Although the Nd3+ absorption cross-section at 884 nm is smaller than those centered at 810 and 750 nm, excitation at 884 nm, that is in resonance with the emitting level, provided the smaller excitation pulse energy threshold and the larger slope efficiency due to the lower quantum defect.

  4. Increase in EPI vaccines coverage after implementation of intermittent preventive treatment of malaria in infant with Sulfadoxine -pyrimethamine in the district of Kolokani, Mali: Results from a cluster randomized control trial

    Directory of Open Access Journals (Sweden)

    Salomon Roger

    2011-07-01

    Full Text Available Abstract Background Even though the efficacy of Intermittent Preventive Treatment in infants (IPTi with Sulfadoxine-Pyrimethamine (SP against clinical disease and the absence of its interaction with routine vaccines of the Expanded Immunization Programme (EPI have been established, there are still some concerns regarding the addition of IPTi, which may increase the work burden and disrupt the routine EPI services especially in Africa where the target immunization coverage remains to be met. However IPTi may also increase the adherence of the community to EPI services and improve EPI coverage, once the benefice of strategy is perceived. Methods To assess the impact of IPTi implementation on the coverage of EPI vaccines, 22 health areas of the district of Kolokani were randomized at a 1:1 ratio to either receive IPTi-SP or to serve as a control. The EPI vaccines coverage was assessed using cross-sectional surveys at baseline in November 2006 and after one year of IPTi pilot-implementation in December 2007. Results At baseline, the proportion of children of 9-23 months who were completely vaccinated (defined as children who received BGG, 3 doses of DTP/Polio, measles and yellow fever vaccines was 36.7% (95% CI 25.3% -48.0%. After one year of implementation of IPTi-SP using routine health services, the proportion of children completely vaccinated rose to 53.8% in the non intervention zone and 69.5% in the IPTi intervention zone (P The proportion of children in the target age groups who received IPTi with each of the 3 vaccinations DTP2, DTP3 and Measles, were 89.2% (95% CI 85.9%-92.0%, 91.0% (95% CI 87.6% -93.7% and 77.4% (95% CI 70.7%-83.2% respectively. The corresponding figures in non intervention zone were 2.3% (95% CI 0.9% -4.7%, 2.6% (95% CI 1.0% -5.6% and 1.7% (95% CI 0.4% - 4.9%. Conclusion This study shows that high coverage of the IPTi can be obtained when the strategy is implemented using routine health services and implementation results

  5. Intermittent hypoxia and neurorehabilitation.

    Science.gov (United States)

    Gonzalez-Rothi, Elisa J; Lee, Kun-Ze; Dale, Erica A; Reier, Paul J; Mitchell, Gordon S; Fuller, David D

    2015-12-15

    In recent years, it has become clear that brief, repeated presentations of hypoxia [i.e., acute intermittent hypoxia (AIH)] can boost the efficacy of more traditional therapeutic strategies in certain cases of neurologic dysfunction. This hypothesis derives from a series of studies in animal models and human subjects performed over the past 35 yr. In 1980, Millhorn et al. (Millhorn DE, Eldridge FL, Waldrop TG. Respir Physiol 41: 87-103, 1980) showed that electrical stimulation of carotid chemoafferent neurons produced a persistent, serotonin-dependent increase in phrenic motor output that outlasts the stimulus for more than 90 min (i.e., a "respiratory memory"). AIH elicits similar phrenic "long-term facilitation" (LTF) by a mechanism that requires cervical spinal serotonin receptor activation and de novo protein synthesis. From 2003 to present, a series of studies demonstrated that AIH can induce neuroplasticity in the injured spinal cord, causing functional recovery of breathing capacity after cervical spinal injury. Subsequently, it was demonstrated that repeated AIH (rAIH) can induce recovery of limb function, and the functional benefits of rAIH are greatest when paired with task-specific training. Since uncontrolled and/or prolonged intermittent hypoxia can elicit pathophysiology, a challenge of intermittent hypoxia research is to ensure that therapeutic protocols are well below the threshold for pathogenesis. This is possible since many low dose rAIH protocols have induced functional benefits without evidence of pathology. We propose that carefully controlled rAIH is a safe and noninvasive modality that can be paired with other neurorehabilitative strategies including traditional activity-based physical therapy or cell-based therapies such as intraspinal transplantation of neural progenitors.

  6. A simple model for turbulence intermittencies

    CERN Document Server

    Rimbert, Nicolas

    2009-01-01

    Whether turbulence intermittencies shall be described by a log-Poisson, a log-stable pdf or other distributions is still debated nowadays. In this paper, a bridge between polymer physics, self-avoiding walk and random vortex stretching is established which may help in getting a new insight on this topics. Actually a very simple relationship between stability index of the stable law and the well known Flory exponent stemming from polymer physics is established. Moreover the scaling of turbulence intermittencies with Reynolds number is also obtained and the overall picture is very close to Tennekes' simple model for the fine scale structure of turbulence [Phys. Fluids, 11, 3 (1968)] : vortex tubes of Kolmogorov length width are bend by bigger vortices of Taylor length scale. This thus results in both a simple and sound model with no fitting parameter needed.

  7. Scaling and Intermittency in Animal Behavior

    CERN Document Server

    Harnos, A; Lawrence, A B; Vattay, G

    1999-01-01

    Scale-invariant spatial or temporal patterns and Lévy flight motion have been observed in a large variety of biological systems. It has been argued that animals in general might perform Lévy flight motion with power law distribution of times between two changes of the direction of motion. Here we study the temporal behaviour of nesting gilts. The time spent by a gilt in a given form of activity has power law probability distribution without finite average. Further analysis reveals intermittent eruption of certain periodic behavioural sequences which are responsible for the scaling behaviour and indicates the existence of a critical state. We show that this behaviour is in close analogy with temporal sequences of velocity found in turbulent flows, where random and regular sequences alternate and form an intermittent sequence.

  8. Optimal Tests of Treatment Effects for the Overall Population and Two Subpopulations in Randomized Trials, using Sparse Linear Programming.

    Science.gov (United States)

    Rosenblum, Michael; Liu, Han; Yen, En-Hsu

    2014-01-01

    We propose new, optimal methods for analyzing randomized trials, when it is suspected that treatment effects may differ in two predefined subpopulations. Such subpopulations could be defined by a biomarker or risk factor measured at baseline. The goal is to simultaneously learn which subpopulations benefit from an experimental treatment, while providing strong control of the familywise Type I error rate. We formalize this as a multiple testing problem and show it is computationally infeasible to solve using existing techniques. Our solution involves a novel approach, in which we first transform the original multiple testing problem into a large, sparse linear program. We then solve this problem using advanced optimization techniques. This general method can solve a variety of multiple testing problems and decision theory problems related to optimal trial design, for which no solution was previously available. In particular, we construct new multiple testing procedures that satisfy minimax and Bayes optimality criteria. For a given optimality criterion, our new approach yields the optimal tradeoff between power to detect an effect in the overall population versus power to detect effects in subpopulations. We demonstrate our approach in examples motivated by two randomized trials of new treatments for HIV.

  9. Comment on "Intermittent plate tectonics?".

    Science.gov (United States)

    Korenaga, Jun

    2008-06-06

    Silver and Behn (Reports, 4 January 2008, p. 85) proposed that intermittent plate tectonics may resolve a long-standing paradox in Earth's thermal evolution. However, their analysis misses one important term, which subsequently brings their main conclusion into question. In addition, the Phanerozoic eustasy record indicates that the claimed effect of intermittency is probably weak.

  10. Forecasting for intermittent spare parts in single-echelon multi-location and multi-item logistics network: Case KONE Global Spares Supply

    OpenAIRE

    Oguji, Nnamdi

    2013-01-01

    The objective of this thesis is to test existing forecasting models for intermittence demand SKU's and implement the best forecast model that suits the inventory control policy of the case company. The optimal forecasting model was selected based on the model that produces optimal performance in terms of customer service levels, inventory total cost and inventory value. Intermittence demand type was categorized based on degree of lumpiness, erratic, smooth-intermittence and intermittent ...

  11. Metabolic Effects of Intermittent Fasting.

    Science.gov (United States)

    Patterson, Ruth E; Sears, Dorothy D

    2017-08-21

    The objective of this review is to provide an overview of intermittent fasting regimens, summarize the evidence on the health benefits of intermittent fasting, and discuss physiological mechanisms by which intermittent fasting might lead to improved health outcomes. A MEDLINE search was performed using PubMed and the terms "intermittent fasting," "fasting," "time-restricted feeding," and "food timing." Modified fasting regimens appear to promote weight loss and may improve metabolic health. Several lines of evidence also support the hypothesis that eating patterns that reduce or eliminate nighttime eating and prolong nightly fasting intervals may result in sustained improvements in human health. Intermittent fasting regimens are hypothesized to influence metabolic regulation via effects on (a) circadian biology, (b) the gut microbiome, and (c) modifiable lifestyle behaviors, such as sleep. If proven to be efficacious, these eating regimens offer promising nonpharmacological approaches to improving health at the population level, with multiple public health benefits.

  12. Acute intermittent porphyria.

    Science.gov (United States)

    Herrick, Ariane L; McColl, Kenneth E L

    2005-04-01

    Acute intermittent porphyria (AIP) is characterised by neurovisceral crises the most common clinical presentation of which is abdominal pain. It is an autosomal dominant condition with incomplete penetrance and is potentially life-threatening. The key point in management is to suspect and confirm the diagnosis as early as possible in order to treat the attack and to avoid inappropriate treatments which may exacerbate the crisis. In this chapter we briefly outline the haem biosynthetic pathway and how deficiencies in individual enzymes give rise to the different porphyrias. We then describe the clinical features and diagnosis of AIP, followed by a discussion of pathogenesis, highlighting advances in the molecular biology of AIP and introducing the debate as to whether neurovisceral crises might result from porphyrin precursor neurotoxicity or from haem deficiency. Finally we discuss management, including family screening, avoidance of triggering factors, analgesia, maintenance of a high calorie intake, and administration of haem derivatives.

  13. Intermittent targeting as a tool to minimize toxicity of tyrosine kinase inhibitor therapy.

    Science.gov (United States)

    Martinelli, Giovanni; Soverini, Simona; Iacobucci, Ilaria; Baccarani, Michele

    2009-02-01

    Tyrosine kinase inhibitor therapy has revolutionized the outcome of chronic myeloid leukemia (CML), and has transformed a fatal disease into a chronic condition for most patients. At present, the therapeutic armamentarium against CML includes imatinib for newly diagnosed patients, and dasatinib and nilotinib, which have both received marketing approval, for imatinib-resistant and imatinib-intolerant disease. Research efforts are now focused on how to optimize therapeutic strategies in an attempt to improve clinical results further, counteract the development of drug resistance and reduce adverse effects. A randomized, international, phase III study of dasatinib dose and schedule optimization in imatinib-resistant and imatinib-intolerant patients with CML has demonstrated that intermittent target inhibition can preserve therapeutic efficacy and reduce toxicity. This finding has important implications, not only for patients with CML, but also for the development of targeted therapies for human malignancies in general.

  14. Critical velocity during continuous and intermittent exercises in children.

    Science.gov (United States)

    Berthoin, Serge; Baquet, Georges; Dupont, Gregory; Van Praagh, Emmanuel

    2006-09-01

    The purpose of this study was to apply the "critical velocity" concept to short intermittent high-intensity running exercises in prepubescent girls and boys and to compare the running performances obtained either by intermittent or continuous exercise runs. Eleven 8 to 11-year-old children underwent a maximal graded field test to determine peak oxygen uptake (peakVO2) and maximal aerobic velocity (MAV). During the six following sessions, they randomly performed three continuous runs (90, 100, and 110% of MAV) and three intermittent runs (120, 130, and 140% of MAV) until exhaustion. Intermittent exercises consisted of repeated 15 s runs each one separated by a 15 s passive recovery interval. For continuous as well as intermittent exercises, distance versus time to exhaustion (TTE) relationships were calculated to determine continuous (CVc) and intermittent (CVi) critical velocities. Values for peakVO2 and MAV were 45.8 +/- 5.3 ml x kg(-1) x min(-1) and 10.5 +/- 1.0 km h(-1), respectively. For the whole population, a significant relationship was found between the distance to exhaustion (DTE) and TTE for continuous (r2= 0.99, P < 0.05) and intermittent exercises (r2 = 0.99, P < 0.05). Significant relationships were found between peakVO2 and both CVc (r2= 0.60, P < 0.01) and CVi (r2= 0.47, P < 0.05). In conclusion, as for continuous exercises, a linear relationship was found between DTE and TTE for short high-intensity intermittent exercises. CVc was significantly related to peakVO2, while a significant lower relationship was found between peakVO2 and CVi.

  15. Multi-objective random search algorithm for simultaneously optimizing wind farm layout and number of turbines

    DEFF Research Database (Denmark)

    Feng, Ju; Shen, Wen Zhong; Xu, Chang

    2016-01-01

    A new algorithm for multi-objective wind farm layout optimization is presented. It formulates the wind turbine locations as continuous variables and is capable of optimizing the number of turbines and their locations in the wind farm simultaneously. Two objectives are considered. One is to maximi...

  16. Optimal illumination and wave form design for imaging in random media.

    Science.gov (United States)

    Borcea, Liliana; Papanicolaou, George; Tsogka, Chrysoula

    2007-12-01

    The problem of optimal illumination for selective array imaging of small and not well separated scatterers in clutter is considered. The imaging algorithms introduced are based on the coherent interferometric (CINT) imaging functional, which can be viewed as a smoothed version of travel-time migration. The smoothing gives statistical stability to the image but it also causes blurring. The trade-off between statistical stability and blurring is optimized with an adaptive version of CINT. The algorithm for optimal illumination and for selective array imaging uses CINT. It is a constrained optimization problem that is based on the quality of the image obtained with adaptive CINT. The resulting optimal illuminations and selectivity improve the resolution of the images significantly, as can be seen in the numerical simulations presented in the paper.

  17. Efficient generation of correlated random numbers using Chebyshev-optimal magnitude-only IIR filters

    CERN Document Server

    Rodríguez, A; Johnson, Steven G.; Rodriguez, Alejandro

    2007-01-01

    We compare several methods for the efficient generation of correlated random sequences (colored noise) by filtering white noise to achieve a desired correlation spectrum. We argue that a class of IIR filter-design techniques developed in the 1970s, which obtain the global Chebyshev-optimum minimum-phase filter with a desired magnitude and arbitrary phase, are uniquely suited for this problem but have seldom been used. The short filters that result from such techniques are crucial for applications of colored noise in physical simulations involving random processes, for which many long random sequences must be generated and computational time and memory are at a premium.

  18. Intermedia and Intermittency

    Directory of Open Access Journals (Sweden)

    Veres Bálint

    2014-12-01

    Full Text Available It is commonly known that medial reflections have been initiated by attempts to secure the borders of discrete medial forms and to define the modus operandi of each essentialized medial area. Later on, the focus of study has shifted to plurimedial formations and the interactions between predefined medial genres. In the last few decades, taxonomic approaches to various multi-, inter-, and transmedial phenomena dominated the discussions, which offered invaluable support in mapping the terrain, but at the same time hindered the analysis of the ephemeral, time-dependent aspects of plurimedial operations. While we explore the properties of each medial configuration, we lose sight of the actual historical drivers that produce ever-new configurations. My thesis is that any discourse on intermediality should be paralleled by a discourse on cultural intermittency, and consequently, media studies should involve an approach that focuses on the “ecosystem” of the constantly renewing media configurations from the point of view of their vitalizing potential and capability to trigger heightened experiences. This approach draws much inspiration from K. Ludwig Pfeiffer’s media anthropology that gives orientation in my paper.

  19. Dispatching Plan Based on Route Optimization Model Considering Random Wind for Aviation Emergency Rescue

    OpenAIRE

    Ming Zhang; Hui Yu; Jue Yu; Yifan Zhang

    2016-01-01

    Aviation emergency rescue is an effective means of nature disaster relief that is widely used in many countries. The dispatching plan of aviation emergency rescue guarantees the efficient implementation of this relief measure. The conventional dispatching plan that does not consider random wind factors leads to a nonprecise quick-responsive scheme and serious safety issues. In this study, an aviation emergency rescue framework that considers the influence of random wind at flight trajectory i...

  20. Intermittency in spiral Poiseuille flow

    Energy Technology Data Exchange (ETDEWEB)

    Heise, M; Abshagen, J; Menck, A; Pflster, G [Institute of Experimental and Applied Physics, University of Kiel, 24098 Kiel (Germany)

    2005-01-01

    The results of an experimental study on intermittent spiral vortices observed in a counter-rotating Taylor-Couette system with an additional axial through flow, i.e. Spiral-Poiseuille flow, are presented. Convectively unstable upstream propagating spiral vortices appear in the laminar basic flow from an oscillatory instability and in general become absolutely unstable at higher inner cylinder Reynolds number. It is found that at Reynolds numbers above the absolute stability border the spiral vortices become unstable and a complex flow state showing intermittent bursts appears. The intermittent flow state is characterised by an irregular alternation between clearly distinguishable 'laminar' phases corresponding to up-and downstream propagating spiral vortices as well as propagating Taylor vortices. For a sufficiently high rate of axial through flow it is found that intermittency can occur directly from the convectively unstable regime of the upstream propagating spiral vortices.

  1. Coho salmon dependence on intermittent streams.

    Science.gov (United States)

    P.J. Wigington; J.L. Ebersole; M.E. Colvin; S.G. Leibowitz; B. Miller; B. Hansen; H. Lavigne; D. White; J.P. Baker; M.R. Church; J.R. Brooks; M.A. Cairns; J.E. Compton

    2006-01-01

    In this paper, we quantify the contributions of intermittent streams to coho salmon production in an Oregon coastal watershed. We provide estimates of (1) proportion of spawning that occurred in intermittent streams, (2) movement of juveniles into intermittent streams, (3) juvenile survival in intermittent and perennial streams during winter, and (4) relative size of...

  2. Anisotropic Homogeneous Turbulence: Hierarchy and Intermittency of Scaling Exponents in the Anisotropic Sectors

    NARCIS (Netherlands)

    Biferale, Luca; Toschi, Federico

    2001-01-01

    We present the first measurements of anisotropic statistical fluctuations in perfectly homogeneous turbulent flows. We address both problems of intermittency in anisotropic sectors and hierarchical ordering of anisotropies on a direct numerical simulation of a three dimensional random Kolmogorov flo

  3. THE DECISION OF THE OPTIMAL PARAMETERS IN MARKOV RANDOM FIELDS OF IMAGES BY GENETIC ALGORITHM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper introduces the principle of genetic algorithm and the basic method of solving Markov random field parameters.Focusing on the shortcomings in present methods,a new method based on genetic algorithms is proposed to solve the parameters in the Markov random field.The detailed procedure is discussed.On the basis of the parameters solved by genetic algorithms,some experim ents on classification of aerial images are given.Experimental results show that the proposed method is effective and the classification results are satisfactory.

  4. Regionalization of patterns of flow intermittence from gauging station records

    Directory of Open Access Journals (Sweden)

    T. H. Snelder

    2013-07-01

    Full Text Available Understanding large-scale patterns in flow intermittence is important for effective river management. The duration and frequency of zero-flow periods are associated with the ecological characteristics of rivers and have important implications for water resources management. We used daily flow records from 628 gauging stations on rivers with minimally modified flows distributed throughout France to predict regional patterns of flow intermittence. For each station we calculated two annual times series describing flow intermittence; the frequency of zero-flow periods (consecutive days of zero flow in each year of record (FREQ; yr−1, and the total number of zero-flow days in each year of record (DUR; days. These time series were used to calculate two indices for each station, the mean annual frequency of zero-flow periods (mFREQ; yr−1, and the mean duration of zero-flow periods (mDUR; days. Approximately 20% of stations had recorded at least one zero-flow period in their record. Dissimilarities between pairs of gauges calculated from the annual times series (FREQ and DUR and geographic distances were weakly correlated, indicating that there was little spatial synchronization of zero flow. A flow-regime classification for the gauging stations discriminated intermittent and perennial stations, and an intermittence classification grouped intermittent stations into three classes based on the values of mFREQ and mDUR. We used random forest (RF models to relate the flow-regime and intermittence classifications to several environmental characteristics of the gauging station catchments. The RF model of the flow-regime classification had a cross-validated Cohen's kappa of 0.47, indicating fair performance and the intermittence classification had poor performance (cross-validated Cohen's kappa of 0.35. Both classification models identified significant environment-intermittence associations, in particular with regional-scale climate patterns and also

  5. Calculation of quantum discord and entanglement measures using the random mutations optimization algorithm

    OpenAIRE

    Chernyavskiy, A. Yu.

    2013-01-01

    The simple and universal global optimization method based on simplified multipopulation genetic algorithm is presented. The method is applied to quantum information problems. It is compared to the genetic algorithm on standard test functions, and also tested on the calculation of quantum discord and minimal entanglement entropy, which is an entanglement measure for pure multipartite states.

  6. Randomly distributed unit sources to enhance optimization in tsunami waveform inversion

    Directory of Open Access Journals (Sweden)

    I. E. Mulia

    2014-05-01

    Full Text Available Determination of sea surface deformation generated by earthquakes is crucial to the success of tsunami modeling. Using waveforms recorded at measurement stations and assuming that the rupture velocity is much faster than the tsunami wave celerity, sea surface deformation caused by a tsunamigenic earthquake can be inferred through an inversion operation using the Green's function technique. However, this inversion method for tsunami waveforms possesses a limitation, in that the inverse matrix does not always exist because of the non-uniqueness of the solution. In addition to the large number of unknown parameters, which might produce many local optima on the misfit function measure, the search towards optimality is confined by the uniform distance of unit sources used in the regular Green's function. This study proposes a new method to both optimize the determination of the unknown parameters and introduce a global optimization method for tsunami waveform inversion. The method has been tested using an artificial tsunami source with real bathymetry data. A significant improvement is achieved by stochastically searching for an optimal distribution of unit source locations prior to the inversion.

  7. Using rapidly-exploring random tree-based algorithms to find smooth and optimal trajectories

    CSIR Research Space (South Africa)

    Matebese, B

    2012-10-01

    Full Text Available feasible solution faster than other algorithms. The drawback of using RRT is that, as the number of samples increases, the probability that the algorithm converges to a sub-optimal solution increases. Furthermore, the path generated by this algorithm...

  8. A random optimization approach for inherent optic properties of nearshore waters

    Science.gov (United States)

    Zhou, Aijun; Hao, Yongshuai; Xu, Kuo; Zhou, Heng

    2016-10-01

    Traditional method of water quality sampling is time-consuming and highly cost. It can not meet the needs of social development. Hyperspectral remote sensing technology has well time resolution, spatial coverage and more general segment information on spectrum. It has a good potential in water quality supervision. Via the method of semi-analytical, remote sensing information can be related with the water quality. The inherent optical properties are used to quantify the water quality, and an optical model inside the water is established to analysis the features of water. By stochastic optimization algorithm Threshold Acceptance, a global optimization of the unknown model parameters can be determined to obtain the distribution of chlorophyll, organic solution and suspended particles in water. Via the improvement of the optimization algorithm in the search step, the processing time will be obviously reduced, and it will create more opportunity for the increasing the number of parameter. For the innovation definition of the optimization steps and standard, the whole inversion process become more targeted, thus improving the accuracy of inversion. According to the application result for simulated data given by IOCCG and field date provided by NASA, the approach model get continuous improvement and enhancement. Finally, a low-cost, effective retrieval model of water quality from hyper-spectral remote sensing can be achieved.

  9. The optimized acupuncture treatment for neck pain caused by cervical spondylosis: a study protocol of a multicentre randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Liang Zhao-Hui

    2012-07-01

    Full Text Available Abstract Background Neck pain is one of the chief symptoms of cervical spondylosis (CS. Acupuncture is a well-accepted and widely used complementary therapy for the management of neck pain caused by CS. In this paper, we present a randomized controlled trial protocol evaluating the use of acupuncture for CS neck pain, comparing the effects of the optimized acupuncture therapy in real practice compared with sham and shallow acupuncture. Methods/Design This trial uses a multicentre, parallel-group, randomized, sham acupuncture and shallow acupuncture, controlled single-blind design. Nine hospitals are involved as trial centres. 945 patients who meet inclusion criteria are randomly assigned to receive optimized acupuncture therapy, sham acupuncture or shallow acupuncture by a computerized central randomization system. The interventions past for 4 weeks with eight to ten treatments in total. The group allocations and interventions are concealed to patients and statisticians. The Northwick Park Neck Pain Questionnaire (NPQ is used as the primary outcome measure, and the McGill Pain Questionnaire (MPQ and The Short Form (36 Health Survey (SF-36 are applied as secondary outcome measures. The evaluation is performed at baseline, at the end of the intervention, and at the end of the first month and the third month during follow-up. The statistical analyses will include baseline data comparison and repeated measures of analysis of variance (ANOVA for primary and secondary outcomes of group and time differences. Adverse events (AEs will be reported if they occur. Discussion This trial is a multicentre randomized control trial (RCT on the efficacy of acupuncture for CS neck pain and has a large sample size and central randomization in China. It will strictly follow the CONSORT statement and STRICTA extension guideline to report high-quality study results. By setting the control groups as sham and shallow acupuncture, this study attempts to reveal the

  10. Intermittent Microwave Drying of Wheat (Triticum aestivum L. Seeds

    Directory of Open Access Journals (Sweden)

    Yan Li

    2014-02-01

    Full Text Available The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s without significantly decreasing the germination rate was obtained at initial moisture content≤ 20.3% along with 20% MOTP. While, if initial moisture content of seeds was ≤ 16.7%, the seeds can be dried more rapidly using MOTP 30% without affecting germination capacity. The results obtained from this study would provide technical basis to select optimal wheat seed processing and design seed drying equipments.

  11. Optimization by Estimation of Distribution with DEUM Framework Based on Markov Random Fields

    Institute of Scientific and Technical Information of China (English)

    Siddhartha Shakya; John McCall

    2007-01-01

    This paper presents a Markov random field (MRP) approach to estimating and sampling the probability distribution in populations of solutions. The approach is used to define a class of algorithms under the general heading distribution estimation using Markov random fields (DEUM). DEUM is a subclass of estimation of distribution algorithms (EDAs) where interaction between solution variables is represented as an undirected graph and the joint probability of a solution is factorized as a Gibbs distribution derived from the structure of the graph. The focus of this paper will be on describing the three main characteristics of DEUM framework, which distinguishes it from the traditional EDA. They are: 1) use of MRF models, 2) fitness modeling approach to estimating the parameter of the model and 3) Monte Carlo approach to sampling from the model.

  12. Using pilot data to size a two-arm randomized trial to find a nearly optimal personalized treatment strategy.

    Science.gov (United States)

    Laber, Eric B; Zhao, Ying-Qi; Regh, Todd; Davidian, Marie; Tsiatis, Anastasios; Stanford, Joseph B; Zeng, Donglin; Song, Rui; Kosorok, Michael R

    2016-04-15

    A personalized treatment strategy formalizes evidence-based treatment selection by mapping patient information to a recommended treatment. Personalized treatment strategies can produce better patient outcomes while reducing cost and treatment burden. Thus, among clinical and intervention scientists, there is a growing interest in conducting randomized clinical trials when one of the primary aims is estimation of a personalized treatment strategy. However, at present, there are no appropriate sample size formulae to assist in the design of such a trial. Furthermore, because the sampling distribution of the estimated outcome under an estimated optimal treatment strategy can be highly sensitive to small perturbations in the underlying generative model, sample size calculations based on standard (uncorrected) asymptotic approximations or computer simulations may not be reliable. We offer a simple and robust method for powering a single stage, two-armed randomized clinical trial when the primary aim is estimating the optimal single stage personalized treatment strategy. The proposed method is based on inverting a plugin projection confidence interval and is thereby regular and robust to small perturbations of the underlying generative model. The proposed method requires elicitation of two clinically meaningful parameters from clinical scientists and uses data from a small pilot study to estimate nuisance parameters, which are not easily elicited. The method performs well in simulated experiments and is illustrated using data from a pilot study of time to conception and fertility awareness.

  13. Reflected BSDEs with Random Default Time and Related Mixed Optimal Stopping-control Problems

    Institute of Scientific and Technical Information of China (English)

    Dong-mei Guo; Xiao-ming Xu

    2013-01-01

    In this paper we study the one-dimensional reflected backward stochastic differential equations which are driven by Brownian motion as well as a mutually independent martingale appearing in a defaultable setting.Using a penalization method,we prove the existence and uniqueness of the solutions to these equations.As an application,we show that under proper assumptions the solution of the reflected equation is the value of the related mixed optimal stopping-control problem.

  14. Optimizing a Military Supply Chain in the Presence of Random, Non-Stationary Demands

    Science.gov (United States)

    2003-12-01

    The challenge is to design an efficient military logistics supply chain that satisfies uncertain, non-stationary demands, while taking into account the...deployment of transportation assets and supplies at the operational level, with possible interdiction by enemy forces, We term this model, Optimal Military ... Logistics Supply Chain (OPTiMiLSC), This is a two-level, multiple time period scenario-based stochastic model OPTiMiLSC uses a combination of

  15. Randomized Search Methods for Solving Markov Decision Processes and Global Optimization

    Science.gov (United States)

    2006-01-01

    over relaxation (SOR) method ([81]). Puterman and Shin [62] proposed a modified policy iteration algorithm, which takes the basic form of PI, with the...99018) (1999). [61] Pintér, J. D., Global Optimization in Action, Kluwer Academic Publisher, The Netherlands, 1996. [62] Puterman , M. L. and Shin, M. C...Modified policy iteration algorithms for dis- counted Markov decision processes,” Management Science, 24, 1127–1137 (1978). [63] Puterman , M. L

  16. Multi-Objective Random Search Algorithm for Simultaneously Optimizing Wind Farm Layout and Number of Turbines

    Science.gov (United States)

    Feng, Ju; Shen, Wen Zhong; Xu, Chang

    2016-09-01

    A new algorithm for multi-objective wind farm layout optimization is presented. It formulates the wind turbine locations as continuous variables and is capable of optimizing the number of turbines and their locations in the wind farm simultaneously. Two objectives are considered. One is to maximize the total power production, which is calculated by considering the wake effects using the Jensen wake model combined with the local wind distribution. The other is to minimize the total electrical cable length. This length is assumed to be the total length of the minimal spanning tree that connects all turbines and is calculated by using Prim's algorithm. Constraints on wind farm boundary and wind turbine proximity are also considered. An ideal test case shows the proposed algorithm largely outperforms a famous multi-objective genetic algorithm (NSGA-II). In the real test case based on the Horn Rev 1 wind farm, the algorithm also obtains useful Pareto frontiers and provides a wide range of Pareto optimal layouts with different numbers of turbines for a real-life wind farm developer.

  17. Bursts in intermittent aeolian saltation

    CERN Document Server

    Carneiro, M V; Herrmann, H J

    2014-01-01

    Close to the onset of Aeolian particle transport through saltation we find in wind tunnel experiments a regime of intermittent flux characterized by bursts of activity. Scaling laws are observed in the time delay between each burst and in the measurements of the wind fluctuations at the critical Shields number $\\theta_c$. The time delay between each burst decreases on average with the increase of the Shields number until saltation becomes non-intermittent and the sand flux becomes continuous. A numerical model for saltation including the wind-entrainment from the turbulent fluctuations can reproduce these observations and gives insight about their origin. We present here also for the first time measurements showing that with feeding it becomes possible to sustain intermittent flux even below the threshold $\\theta_c$ for natural saltation initiation.

  18. Study protocol: optimization of complex palliative care at home via telemedicine. A cluster randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Hasselaar Jeroen

    2011-08-01

    Full Text Available Abstract Background Due to the growing number of elderly with advanced chronic conditions, healthcare services will come under increasing pressure. Teleconsultation is an innovative approach to deliver quality of care for palliative patients at home. Quantitative studies assessing the effect of teleconsultation on clinical outcomes are scarce. The aim of this present study is to investigate the effectiveness of teleconsultation in complex palliative homecare. Methods/Design During a 2-year recruitment period, GPs are invited to participate in this cluster randomized controlled trial. When a GP refers an eligible patient for the study, the GP is randomized to the intervention group or the control group. Patients in the intervention group have a weekly teleconsultation with a nurse practitioner and/or a physician of the palliative consultation team. The nurse practitioner, in cooperation with the palliative care specialist of the palliative consultation team, advises the GP on treatment policy of the patient. The primary outcome of patient symptom burden is assessed at baseline and weekly using the Edmonton Symptom Assessment Scale (ESAS and at baseline and every four weeks using the Hospital Anxiety and Depression Scale (HADS. Secondary outcomes are self-perceived burden from informal care (EDIZ, patient experienced continuity of medical care (NCQ, patient and caregiver satisfaction with the teleconsultation (PSQ, the experienced problems and needs in palliative care (PNPC-sv and the number of hospital admissions. Discussion This is one of the first randomized controlled trials in palliative telecare. Our data will verify whether telemedicine positively affects palliative homecare. Trial registration The Netherlands National Trial Register NTR2817

  19. Intermittency in spherical Couette dynamos

    CERN Document Server

    Raynaud, Raphaël; 10.1103/PhysRevE.87.033011

    2013-01-01

    We investigate dynamo action in three-dimensional numerical simulations of turbulent spherical Couette flows. Close to the onset of dynamo action, the magnetic field exhibits an intermittent behavior, characterized by a series of short bursts of the magnetic energy separated by low-energy phases. We show that this behavior corresponds to the so-called on-off intermittency. This behavior is here reported for dynamo action with realistic boundary conditions. We investigate the role of magnetic boundary conditions in this phenomenon.

  20. Optimization of Phenolic Antioxidant Extraction from Wuweizi (Schisandra chinensis Pulp Using Random-Centroid Optimazation Methodology

    Directory of Open Access Journals (Sweden)

    Xiong Yu

    2011-09-01

    Full Text Available The extraction optimization and composition analysis of polyphenols in the fresh pulp of Wuweizi (Schisandra chinensis have been investigated in this study. The extraction process of polyphenols from Wuweizi pulp was optimized using Random-Centroid Optimization (RCO methodology. Six factors including liquid and solid ratio, ethanol concentration, pH, temperature, heating time and extraction times, and three extraction targets of polyphenol content, antioxidant activity and extract yield were considered in the RCO program. Three sets of optimum proposed factor values were obtained corresponding to three extraction targets respectively. The set of optimum proposed factor values for polyphenol extraction given was chosen in further experiments as following: liquid and solid ratio (v/w 8, ethanol 67.3% (v/v, initial pH 1.75, temperature 55 °C for 4 h and extraction repeated for 4 times. The Wuweizi polyphenol extract (WPE was obtained with a yield of 16.37 mg/g and composition of polyphenols 1.847 mg/g, anthocyanins 0.179 mg/g, sugar 9.573 mg/g and protein 0.327 mg/g. The WPE demonstrated high scavenging activities against DPPH radicals.

  1. Optimal hand washing technique to minimize bacterial contamination before neuraxial anesthesia: a randomized control trial.

    Science.gov (United States)

    Siddiqui, N; Friedman, Z; McGeer, A; Yousefzadeh, A; Carvalho, J C; Davies, S

    2017-02-01

    Infectious complications related to neuraxial anesthesia may result in adverse outcomes. There are no best practice guidelines regarding hand-sanitizing measures specifically for these procedures. The objective of this study was to compare the growth of microbial organisms on the operator's forearm between five common techniques of hand washing for labor epidurals. In this single blind randomized controlled trial, all anesthesiologists performing labor epidurals in a tertiary care hospital were randomized into five study groups: hand washing with alcohol gel only up to elbows (Group A); hand washing with soap up to elbows, sterile towel to dry, followed by alcohol gel (Group B); hand washing with soap up to elbows, non-sterile towel to dry, followed by alcohol gel (Group C); hand washing with soap up to elbows, non-sterile towel to dry (Group D) or hand washing with soap up to elbows, sterile towel to dry (Group E). The number of colonies for each specimen/rate per 100 specimens on one or both arms per group was measured. The incidence of colonization was 2.5, 23.0, 18.5, 114.5, and 53.0 in Groups A, B, C, D and E, respectively. Compared to Group A, the odds ratio of bacterial growth for Group B was 1.52 (P=0.519), Group C 5.44 (P=0.003), Group D 13.82 (Phand-sanitizing practices among epidural practitioners. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Pregnancy Research on Osteopathic Manipulation Optimizing Treatment Effects: The PROMOTE Study A Randomized Controlled Trial

    Science.gov (United States)

    HENSEL, Kendi L.; BUCHANAN, Steve; BROWN, Sarah K.; RODRIGUEZ, Mayra; CRUSER, des Anges

    2014-01-01

    Objective To evaluate the efficacy of Osteopathic Manipulative Treatment (OMT) to reduce low back pain and improve functioning during the third trimester in pregnancy and improve selected outcomes of labor and delivery. Study Design PROMOTE was a randomized, placebo-controlled trial of 400 women in their third trimester. Women were randomized to usual care only (UCO), usual care plus OMT (OMT), or usual care plus placebo ultrasound treatment (PUT). The study included seven treatments over nine weeks. The OMT protocol included specific techniques administered by board-certified OMT specialists. Outcomes were assessed using self-report measures for pain and back-related functioning, and medical records for delivery outcomes. Results There were 136 women in the OMT group, 131 in PUT, and 133 in UCO. Characteristics at baseline were similar across groups. Findings indicate significant treatment effects for pain and back related functioning (POMT group similar to that of the PUT, but both groups were significantly improved compared to UCO. For secondary outcome of meconium- stained amniotic fluid there were no differences between the groups. Conclusion OMT was effective for mitigating pain and functional deterioration compared to the UCO group; however OMT did not differ significantly from PUT. This may be attributed to PUT being a more active treatment than intended. There was no higher likelihood of conversion to high risk status based on treatment group. Therefore, OMT is a safe, effective adjunctive modality to improve pain and functioning during their third trimester. PMID:25068560

  3. Optimization of random amplified polymorphic DNA techniques for use in genetic studies of Cuban Triatominae.

    Science.gov (United States)

    Fraga, Jorge; Rodriguez, Jinnay; Fuentes, Omar; Fernandez-Calienes, Aymé; Castex, Mayda

    2005-01-01

    Random amplified polymorphic DNA (RAPD) technique is a simple and reliable method to detect DNA polymorphism. Several factors can affect the amplification profiles, thereby causing false bands and non-reproducibility of assay. In this study, we analyzed the effect of changing the concentration of primer, magnesium chloride, template DNA and Taq DNA polymerase with the objective of determining their optimum concentration for the standardization of RAPD technique for genetic studies of Cuban Triatominae. Reproducible amplification patterns were obtained using 5 pmoL of primer, 2.5 mM of MgCl2, 25 ng of template DNA and 2 U of Taq DNA polymerase in 25 microL of the reaction. A panel of five random primers was used to evaluate the genetic variability of T. flavida. Three of these (OPA-1, OPA-2 and OPA-4) generated reproducible and distinguishable fingerprinting patterns of Triatominae. Numerical analysis of 52 RAPD amplified bands generated for all five primers was carried out with unweighted pair group method analysis (UPGMA). Jaccard's Similarity Coefficient data were used to construct a dendrogram. Two groups could be distinguished by RAPD data and these groups coincided with geographic origin, i.e. the populations captured in areas from east and west of Guanahacabibes, Pinar del Río. T. flavida present low interpopulation variability that could result in greater susceptibility to pesticides in control programs. The RAPD protocol and the selected primers are useful for molecular characterization of Cuban Triatominae.

  4. Improving the quality of sleep with an optimal pillow: a randomized, comparative study.

    Science.gov (United States)

    Jeon, Mi Yang; Jeong, HyeonCheol; Lee, SeungWon; Choi, Wonjae; Park, Jun Hyuck; Tak, Sa Jin; Choi, Dae Ho; Yim, Jongeun

    2014-07-01

    Because sleep comprises one-third of a person's life, using an optimal pillow for appropriate neck support to maintain cervical curve may contribute to improve quality of sleep. Design of orthopedic pillow conforms to orthopedic guidelines to ensure the right support of the cervical curve. The aim of this study was to investigate effect of different pillow shape and content on cervical curve, pillow temperature, and pillow comfort. A feather pillow is regarded as a standard pillow, and a memory foam pillow is one of the most popular pillows among pillow users. We, therefore, compared these two pillows with an orthopedic pillow. Twenty healthy subjects (10 men and 10 women; age range, 21-30 years) participated in the study. Each subject was asked to assume the supine position with 3 different pillows for 30 minute in each trial and then cervical curve, pillow temperature, and pillow comfort were measured. When comparing the cervical curve of the 3 different pillows, that of the orthopedic pillow was significantly higher than that of the other 2 pillows (p optimal pillow for sleep quality.

  5. Can racial disparities in optimal gout treatment be reduced? evidence from a randomized trial

    Directory of Open Access Journals (Sweden)

    Singh Jasvinder A

    2012-02-01

    Full Text Available Abstract There is a disproportionate burden of gout in African-Americans in the U.S. due to a higher disease prevalence and lower likelihood of receiving urate-lowering therapy (ULT, compared to Caucasians. There is an absence of strong data as to whether the response to ULT differs by race/ethnicity. BMC Musculoskeletal Disorders recently published a secondary analyses of the CONFIRMS trial, a large randomized controlled, double-blind trial of 2,269 gout patients. The authors reported that the likelihood of achieving the primary study efficacy end-point of achieving serum urate Please see related article: http://www.biomedcentral.com/1471-2474/13/15

  6. Prospective randomized study for optimal insulin therapy in type 2 diabetic patients with secondary failure

    Directory of Open Access Journals (Sweden)

    Tojo Katsuyoshi

    2008-05-01

    Full Text Available Abstract Background The large clinical trials proved that Basal-Bolus (BB insulin therapy was effective in the prevention of diabetic complications and their progression. However, BB therapy needs multiple insulin injections per a day. In this regard, a biphasic insulin analogue needs only twice-daily injections, and is able to correct postprandial hyperglycemia. Therefore it may achieve the blood glucose control as same as that of BB therapy and prevent the diabetic complications including macroangiopathy. Methods In PROBE (Prospective, Randomized, Open, Blinded-Endpoint design, forty-two type 2 diabetic patients (male: 73.8%, median(inter quartile range age: 64.5(56.8~71.0years with secondary failure of sulfonylurea (SU were randomly assigned to BB therapy with a thrice-daily insulin aspart and once-daily basal insulin (BB group or to conventional therapy with a twice-daily biphasic insulin analogue (30 Mix group, and were followed up for 6 months to compare changes in HbA1c, daily glycemic profile, intima-media thickness (IMT of carotid artery, adiponectin levels, amounts of insulin used, and QOL between the two groups. Results After 6 months, HbA1c was significantly reduced in both groups compared to baseline (30 Mix; 9.3(8.1~11.3 → 7.4(6.9~8.7%, p Conclusion Both BB and 30 mix group produced comparable reductions in HbA1c in type 2 diabetic patients with secondary failure. There was no significant change in IMT as an indicator of early atherosclerotic changes between the two groups. The basal-bolus insulin therapy may not be necessarily needed if the type 2 diabetic patients have become secondary failure. Trial registration Current Controlled Trials number, NCT00348231

  7. Embedded Platform for Automatic Testing and Optimizing of FPGA Based Cryptographic True Random Number Generators

    Directory of Open Access Journals (Sweden)

    M. Varchola

    2009-12-01

    Full Text Available This paper deals with an evaluation platform for cryptographic True Random Number Generators (TRNGs based on the hardware implementation of statistical tests for FPGAs. It was developed in order to provide an automatic tool that helps to speed up the TRNG design process and can provide new insights on the TRNG behavior as it will be shown on a particular example in the paper. It enables to test sufficient statistical properties of various TRNG designs under various working conditions on the fly. Moreover, the tests are suitable to be embedded into cryptographic hardware products in order to recognize TRNG output of weak quality and thus increase its robustness and reliability. Tests are fully compatible with the FIPS 140 standard and are implemented by the VHDL language as an IP-Core for vendor independent FPGAs. A recent Flash based Actel Fusion FPGA was chosen for preliminary experiments. The Actel version of the tests possesses an interface to the Actel’s CoreMP7 softcore processor that is fully compatible with the industry standard ARM7TDMI. Moreover, identical tests suite was implemented to the Xilinx Virtex 2 and 5 in order to compare the performance of the proposed solution with the performance of already published one based on the same FPGAs. It was achieved 25% and 65% greater clock frequency respectively while consuming almost equal resources of the Xilinx FPGAs. On the top of it, the proposed FIPS 140 architecture is capable of processing one random bit per one clock cycle which results in 311.5 Mbps throughput for Virtex 5 FPGA.

  8. Radiotherapy for calcaneodynia. Results of a single center prospective randomized dose optimization trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, O.J.; Jeremias, C.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

    2013-04-15

    The aim of this work was to compare the efficacy of two different dose fractionation schedules for radiotherapy of patients with calcaneodynia. Between February 2006 and April 2010, 457 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received radiotherapy using the orthovoltage technique. One radiotherapy series consisted of 6 single fractions/3 weeks. In case of insufficient remission of pain after 6 weeks a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. Endpoint was pain reduction. Pain was measured before, immediately after, and 6 weeks after radiotherapy using a visual analogue scale (VAS) and a comprehensive pain score (CPS). The overall response rate for all patients was 87 % directly after and 88 % 6 weeks after radiotherapy. The mean VAS values before, immediately after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 65.5 {+-} 22.1 and 64.0 {+-} 20.5 (p = 0.188), 34.8 {+-} 24.7 and 39.0 {+-} 26.3 (p = 0.122), and 25.1 {+-} 26.8 and 28.9 {+-} 26.8 (p = 0.156), respectively. The mean CPS before, immediately after, and 6 weeks after treatment was 10.1 {+-} 2.7 and 10.0 {+-} 3.0 (p = 0.783), 5.6 {+-} 3.7 and 6.0 {+-} 3.9 (p = 0.336), 4.0 {+-} 4.1 and 4.3 {+-} 3.6 (p = 0.257), respectively. No statistically significant differences between the two single dose trial arms for early (p = 0.216) and delayed response (p = 0.080) were found. Radiotherapy is an effective treatment option for the management of calcaneodynia. For radiation protection reasons, the dose for a radiotherapy series is recommended not to exceed 3-6 Gy. (orig.)

  9. Intermittent control of coexisting attractors.

    Science.gov (United States)

    Liu, Yang; Wiercigroch, Marian; Ing, James; Pavlovskaia, Ekaterina

    2013-06-28

    This paper proposes a new control method applicable for a class of non-autonomous dynamical systems that naturally exhibit coexisting attractors. The central idea is based on knowledge of a system's basins of attraction, with control actions being applied intermittently in the time domain when the actual trajectory satisfies a proximity constraint with regards to the desired trajectory. This intermittent control uses an impulsive force to perturb one of the system attractors in order to switch the system response onto another attractor. This is carried out by bringing the perturbed state into the desired basin of attraction. The method has been applied to control both smooth and non-smooth systems, with the Duffing and impact oscillators used as examples. The strength of the intermittent control force is also considered, and a constrained intermittent control law is introduced to investigate the effect of limited control force on the efficiency of the controller. It is shown that increasing the duration of the control action and/or the number of control actuations allows one to successfully switch between the stable attractors using a lower control force. Numerical and experimental results are presented to demonstrate the effectiveness of the proposed method.

  10. Voltage Stability Evaluation Incorporating Wind Power Intermittency

    Institute of Scientific and Technical Information of China (English)

    Libao SHI; Yang ZHAO; Yixin NI; Liangzhong YAO; Masoud BAZARGAN

    2013-01-01

    A simulation framework is proposed to evaluate the voltage stability of power systems incorporating wind power intermittency.Firstly,the power output modelings of three types of wind turbines are discussed.Secondly,the Jensen model is employed to simulate the wind farm with the wake effect.The Monte Carlo based technique is used to conduct the voltage stability evaluation incorporating the randomness of the wind speed based on the Weibull probability distribution.Thirdly,the relative sensitivity index (RSI) is calculated to identify weak buses during analysis.Finally,case studies with different simulation scenarios are carried out.Some statistical results involving weakness probability,expected value and variance of RSI as well as preliminary conclusions are drawn based on numerical simulation results.

  11. Compensatory mechanisms activated with intermittent energy restriction

    DEFF Research Database (Denmark)

    Coutinho, Sílvia Ribeiro; Halset, Eline Holli; Gåsbakk, Sigrid

    2017-01-01

    : 39 ± 9 y) with obesity (BMI: 36 ± 4 kg/m2) were randomized to lose a similar weight with an IER (N = 18) or a CER (N = 17) diet over a 12 week period. Macronutrient composition and overall energy restriction (33% reduction) were similar between groups. Body weight/composition, RMR, fasting......) were measured before and after WL. Results: Changes in body weight (≈12.5% WL) and composition were similar in both groups. Fasting RQ and ExEff at 10 W increased in both groups. Losing weight, either by IER or CER dieting, did not induce significant changes in subjective appetite ratings. RMR......Background & aims: Strong compensatory responses, with reduced resting metabolic rate (RMR), increased exercise efficiency (ExEff) and appetite, are activated when weight loss (WL) is achieved with continuous energy restriction (CER), which try to restore energy balance. Intermittent energy...

  12. Benign painful elbow syndrome. First results of a single center prospective randomized radiotherapy dose optimization trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, O.J.; Hertel, S.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

    2012-10-15

    Background and purpose: The goal of the present study was to evaluate the efficacy of two different dose-fractionation schedules for radiotherapy (RT) of patients with painful elbow syndrome. Patients and methods: Between February 2006 and February 2010, 199 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received RT in orthovoltage technique. One RT course consisted of 6 single fractions/3 weeks. In case of insufficient remission of pain after 6 weeks a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. Endpoint was pain reduction. Pain was measured before, right after, and 6 weeks after RT by a visual analogue scale (VAS) and a comprehensive pain score (CPS). Results: The overall response rate for all patients was 80% direct after and 91% 6 weeks after RT. The mean VAS values before, after and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 59.6 {+-} 20.2 and 55.7 {+-} 18.0 (p = 0.463), 32.1 {+-} 24.5 and 34.4 {+-} 22.5 (p = 0.256), and 27.0 {+-} 27.7 and 23.5 {+-} 21.6 (p = 0.818). The mean CPS before, after, and 6 weeks after treatment was 8.7 {+-} 2.9 and 8.1 {+-} 3.1 (p = 0.207), 4.5 {+-} 3.2 and 5.0 {+-} 3.4 (p = 0.507), 3.9 {+-} 3.6 and 2.8 {+-} 2.8 (p = 0.186), respectively. No statistically significant differences between the two single dose trial arms for early (p = 0.103) and delayed response (p = 0.246) were found. Conclusion: RT is an effective treatment option for the management of benign painful elbow syndrome. For radiation protection reasons the dose for a RT series is recommended not to exceed 3.0 Gy. (orig.)

  13. Radiotherapy for achillodynia. Results of a single-center prospective randomized dose-optimization trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, O.J.; Jeremias, C.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Dept. of Radiation Oncology

    2013-02-15

    Background and purpose: The aim of this study was to compare the efficacy of two different dose-fractionation schedules for radiotherapy of patients with achillodynia. Patients and methods: Between February 2006 and February 2010, 112 consecutive evaluable patients were recruited for this prospective randomized trial. All patients underwent radiotherapy with an orthovoltage technique. One radiotherapy course consisted of 6 single fractions over 3 weeks. In case of insufficient remission of pain after 6 weeks, a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. The endpoint was pain reduction. Pain was measured before, right after, and 6 weeks after radiotherapy with a visual analogue scale (VAS) and a comprehensive pain score (CPS). Results: The overall response rate for all patients was 84% directly after and 88% 6 weeks after radiotherapy. The mean VAS values before, directly after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 55.7 {+-} 21.0 and 58.2 {+-} 23.5 (p = 0.526), 38.0 {+-} 23.2 and 30.4 {+-} 22.6 (p = 0.076), and 35.4 {+-} 25.9 and 30.9 {+-} 25.4 (p = 0.521), respectively. The mean CPS before, directly after, and 6 weeks after treatment was 8.2 {+-} 3.0 and 8.9 {+-} 3.3 (p = 0.239), 5.6 {+-} 3.1 and 5.4 {+-} 3.3 (p = 0.756), 4.4 {+-} 2.6 and 5.3 {+-} 3.8 (p = 0.577), respectively. No statistically significant differences were found between the two single-dose trial arms for early (p = 0.366) and delayed response (p = 0.287). Conclusion: Radiotherapy is an effective treatment option for the management of achillodynia. For radiation protection, the dose of a radiotherapy series is recommended not to exceed 3-6 Gy. (orig.)

  14. Linear Unbiased Optimal Filter for Discrete-Time Systems with One-Step Random Delays and Inconsecutive Packet Dropouts

    Directory of Open Access Journals (Sweden)

    Jian Ding

    2013-11-01

    Full Text Available This paper is concerned with the linear unbiased minimum variance estimation problem for discrete-time stochastic linear control systems with one-step random delay and inconsecutive packet dropout. A new model is developed to describe the phenomena of the one-step delay and inconsecutive packet dropout by employing a Bernoulli distributed stochastic variable. Based on the model, a recursive linear unbiased optimal filter in the linear minimum variance sense is designed by the method of completing the square. The solution to the linear filter is given by three equations including a Riccati equation, a Lyapunov equation and a simple difference equation. A sufficient condition for the existence of the steady-state filter is given. A simulation shows the effectiveness of the proposed algorithm.    

  15. Optimization of Quick Curing Process for Preserved Egg by Intermittent Pressurization%间歇式加压技术快速腌制皮蛋工艺研究

    Institute of Scientific and Technical Information of China (English)

    孙静; 杜金平; 马美湖

    2012-01-01

    为缩短皮蛋的生产周期,按照U10(108)均匀试验设计,采用间歇式加压技术进行腌制,利用压力控制程序调控腌制罐中的加压及卸压过程,利用高压加快腌制液中碱向蛋内渗透,低压时,蛋内压力小于蛋外环境的压力,从而加速蛋内产生的水分和H2S、NH3及CO2等气体向外逸出,有利于碱进一步向蛋内渗透,起到加快皮蛋成熟的作用。通过对皮蛋蛋清、外层蛋黄及内层蛋黄的游离碱度、蛋黄硬化率和感官等指标进行综合评分,选出最优工艺条件组合为:碱(食品级氢氧化钠)质量分数5%,高压180kPa保持40min,低压保持12min,腌制206h;用此法腌制皮蛋最多可将生产周期缩短到传统工艺的78%,可以大幅提高生产效率;各因素对皮蛋品质的影响均具有显著性(P〈0.05),影响作用按大小顺序排列为腌制时长〉低压保持时间〉高压保持时间〉碱质量分数〉高压压力,综合品质与高压值呈负相关关系,在腌制时长一定的条件下,高低压分配对皮蛋品质具有重要作用,其中低压保持时间对内层蛋黄游离碱度影响最显著。%In order to shorten the production period of preserved egg,intermittent pressurization was used to develop a rapid curing device.In the curing tank,pressurized and depressurized was under the control of a pressure control program.The permeation of alkali from the curing solution into eggs was accelerated at high pressure.Conversely,when the pressure inside eggs was lower than that outside eggs at low pressure,the leakage of water,H2S,NH3 and CO2 generated in eggs was accelerated,thereby being beneficial to further permeation of alkali into eggs and accelerating the ripening of preserved eggs.Based on a comprehensive evaluation of free alkalinity in egg white and yolk,the hardening rate of egg yolk and sensory characteristics,the optimum curing conditions were determined as follows:the optimal alkali concentration was 5

  16. Random networks of carbon nanotubes optimized for transistor mass-production: searching for ultimate performance

    Science.gov (United States)

    Žeželj, M.; Stanković, I.

    2016-10-01

    Random networks of as-grown single-walled carbon nanotubes (CNTs) contain both metallic (m-CNTs) and semiconducting (s-CNTs) nanotubes in an approximate ratio of 1:2, which leads to a trade-off between on-conductance and the on/off ratio. We demonstrate how this design problem can be solved with a realistic numerical approach. We determine the CNT density, length, and channel dimensions under which CNT thin-film transistors simultaneously attain on-conductance higher than 1 μS and an on/off ratio higher than 104. The fact that asymmetric systems have more pronounced finite-size scaling behavior than symmetric systems allows us additional design freedom. A realization probability of the desired characteristics higher than 99% is obtained for the channels with aspect ratio {L}{{CH}}/{W}{{CH}}\\lt 1.2 and normalized size {L}{{CH}}{W}{{CH}}/{l}{{CNT}}2\\gt 250 when the CNT length is {l}{{CNT}}=4-20 μ {{m}} and the normalized density of CNTs is close to the value where the probability of percolation through only s-CNT pathways reaches its maximum.

  17. Optimism

    Science.gov (United States)

    Carver, Charles S.; Scheier, Michael F.; Segerstrom, Suzanne C.

    2010-01-01

    Optimism is an individual difference variable that reflects the extent to which people hold generalized favorable expectancies for their future. Higher levels of optimism have been related prospectively to better subjective well-being in times of adversity or difficulty (i.e., controlling for previous well-being). Consistent with such findings, optimism has been linked to higher levels of engagement coping and lower levels of avoidance, or disengagement, coping. There is evidence that optimism is associated with taking proactive steps to protect one's health, whereas pessimism is associated with health-damaging behaviors. Consistent with such findings, optimism is also related to indicators of better physical health. The energetic, task-focused approach that optimists take to goals also relates to benefits in the socioeconomic world. Some evidence suggests that optimism relates to more persistence in educational efforts and to higher later income. Optimists also appear to fare better than pessimists in relationships. Although there are instances in which optimism fails to convey an advantage, and instances in which it may convey a disadvantage, those instances are relatively rare. In sum, the behavioral patterns of optimists appear to provide models of living for others to learn from. PMID:20170998

  18. Neural-Fuzzy Digital Strategy of Continuous-Time Nonlinear Systems Using Adaptive Prediction and Random-Local-Optimization Design

    Directory of Open Access Journals (Sweden)

    Zhi-Ren Tsai

    2013-01-01

    Full Text Available A tracking problem, time-delay, uncertainty and stability analysis of a predictive control system are considered. The predictive control design is based on the input and output of neural plant model (NPM, and a recursive fuzzy predictive tracker has scaling factors which limit the value zone of measured data and cause the tuned parameters to converge to obtain a robust control performance. To improve the further control performance, the proposed random-local-optimization design (RLO for a model/controller uses offline initialization to obtain a near global optimal model/controller. Other issues are the considerations of modeling error, input-delay, sampling distortion, cost, greater flexibility, and highly reliable digital products of the model-based controller for the continuous-time (CT nonlinear system. They are solved by a recommended two-stage control design with the first-stage (offline RLO and second-stage (online adaptive steps. A theorizing method is then put forward to replace the sensitivity calculation, which reduces the calculation of Jacobin matrices of the back-propagation (BP method. Finally, the feedforward input of reference signals helps the digital fuzzy controller improve the control performance, and the technique works to control the CT systems precisely.

  19. Discrete-Time Pricing and Optimal Exercise of American Perpetual Warrants in the Geometric Random Walk Model

    Energy Technology Data Exchange (ETDEWEB)

    Vanderbei, Robert J., E-mail: rvdb@princeton.edu [Princeton University, Department of Operations Research and Financial Engineering (United States); P Latin-Small-Letter-Dotless-I nar, Mustafa C., E-mail: mustafap@bilkent.edu.tr [Bilkent University, Department of Industrial Engineering (Turkey); Bozkaya, Efe B. [Sabanc Latin-Small-Letter-Dotless-I University, Faculty of Administrative Sciences (Turkey)

    2013-02-15

    An American option (or, warrant) is the right, but not the obligation, to purchase or sell an underlying equity at any time up to a predetermined expiration date for a predetermined amount. A perpetual American option differs from a plain American option in that it does not expire. In this study, we solve the optimal stopping problem of a perpetual American option (both call and put) in discrete time using linear programming duality. Under the assumption that the underlying stock price follows a discrete time and discrete state Markov process, namely a geometric random walk, we formulate the pricing problem as an infinite dimensional linear programming (LP) problem using the excessive-majorant property of the value function. This formulation allows us to solve complementary slackness conditions in closed-form, revealing an optimal stopping strategy which highlights the set of stock-prices where the option should be exercised. The analysis for the call option reveals that such a critical value exists only in some cases, depending on a combination of state-transition probabilities and the economic discount factor (i.e., the prevailing interest rate) whereas it ceases to be an issue for the put.

  20. Distance stereo acuity improvement in intermittent exotropic patients following strabismus surgery.

    Science.gov (United States)

    O'Neal, T D; Rosenbaum, A L; Stathacopoulos, R A

    1995-01-01

    To determine whether distance stereo acuity improved following strabismus surgery in patients with intermittent exotropia, we tested 20 patients (5 to 87 years old) preoperatively and postoperatively using the Mentor BVAT II Video acuity tester (Santa Barbara, Calif) and binocular visual system. Acuity improved in 75% as assessed by contour circles and in 45% as assessed by random dot E tests at distance. Our results suggest that surgical realignment of intermittent exotropia restores distance stereo acuity. We conclude that measuring distance stereo acuity offers valuable information in the evaluation of the intermittent exotropic patient.

  1. Optimization

    CERN Document Server

    Pearce, Charles

    2009-01-01

    Focuses on mathematical structure, and on real-world applications. This book includes developments in several optimization-related topics such as decision theory, linear programming, turnpike theory, duality theory, convex analysis, and queuing theory.

  2. Intermittent exotropia: Surgical treatment strategies

    Directory of Open Access Journals (Sweden)

    Jai Aditya Kelkar

    2015-01-01

    Full Text Available Surgical management of intermittent exotropias (IXTs is ambiguous, with techniques of management varying widely between institutions. This review aims to examine available literature on the surgical management of IXT. A literature search was performed using PubMed, Web of Knowledge, LILACS, and the University of Liverpool Orthoptic Journals and Conference Transactions Database. All English-language papers published between 1958 and the present day were considered.

  3. Power-constrained intermittent control

    OpenAIRE

    Gawthrop, P.; Wagg, D.; Neild, S.; Wang, L

    2013-01-01

    In this article, input power, as opposed to the usual input amplitude, constraints are introduced in the context of intermittent control. They are shown to result in a combination of quadratic optimisation and quadratic constraints. The main motivation for considering input power constraints is its similarity with semi-active control. Such methods are commonly used to provide damping in mechanical systems and structures. It is shown that semi-active control can be re-expressed and generalised...

  4. Sulfide elimination by intermittent nitrate dosing in sewer sediments

    Institute of Scientific and Technical Information of China (English)

    Yanchen Liu; Chen Wu; Xiaohong Zhou; David Z.Zhu; Hanchang Shi

    2015-01-01

    The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards,and requires expensive programs for its prevention.The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments.The study was carried out based on lab-scale experiments and batch tests using real sewer sediments.The intermittent nitrate dosing mode and the optimal control condition were investigated.The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment.The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide)ratio with slight excess nitrate is necessary for optimal conditions ofefficient sulfide control with lower carbon source loss.The opth-nal control condition is feasible for the sulfide elimination in sewer systems.

  5. 'Help for Hay Fever', a goal-focused intervention for people with intermittent allergic rhinitis, delivered in Scottish community pharmacies: study protocol for a pilot cluster randomized controlled trial

    NARCIS (Netherlands)

    Porteous, T.; Wyke, S.; Smith, S.; Bond, C.; Francis, J.; Lee, A.J.; Lowrie, R.; Scotland, G.; Sheikh, A.; Thomas, M.; Smith, Lorraine

    2013-01-01

    BACKGROUND: Despite the availability of evidence-based guidelines for managing allergic rhinitis in primary care, management of the condition in the United Kingdom (UK) remains sub-optimal. Its high prevalence and negative effects on quality of life, school performance, productivity and co-morbid

  6. 'Help for Hay Fever', a goal-focused intervention for people with intermittent allergic rhinitis, delivered in Scottish community pharmacies: study protocol for a pilot cluster randomized controlled trial

    NARCIS (Netherlands)

    Porteous, T.; Wyke, S.; Smith, S.; Bond, C.; Francis, J.; Lee, A.J.; Lowrie, R.; Scotland, G.; Sheikh, A.; Thomas, M.; Smith, Lorraine

    2013-01-01

    BACKGROUND: Despite the availability of evidence-based guidelines for managing allergic rhinitis in primary care, management of the condition in the United Kingdom (UK) remains sub-optimal. Its high prevalence and negative effects on quality of life, school performance, productivity and co-morbid re

  7. Optimized Axillary Vein Technique versus Subclavian Vein Technique in Cardiovascular Implantable Electronic Device Implantation: A Randomized Controlled Study

    Institute of Scientific and Technical Information of China (English)

    Peng Liu; Yi-Feng Zhou; Peng Yang; Yan-Sha Gao; Gui-Ru Zhao; Shi-Yan Ren; Xian-Lun Li

    2016-01-01

    Background:The conventional venous access for cardiovascular implantable electronic device (CIED) is the subclavian vein,which is often accompanied by high complication rate.The aim of this study was to assess the efficacy and safety of optimized axillary vein technique.Methods:A total of 247 patients undergoing CIED implantation were included and assigned to the axillary vein group or the subclavian vein group randomly.Success rate of puncture and complications in the perioperative period and follow-ups were recorded.Results:The overall success rate (95.7% vs.96.0%) and one-time success rate (68.4% vs.66.1%) of punctures were similar between the two groups.In the subclavian vein group,pneumothorax occurred in three patients.The subclavian gaps of three patients were too tight to allow operation of the electrode lead.In contrast,there were no puncture-associated complications in the axillary vein group.In the patient follow-ups,two patients in the subclavian vein group had subclavian crush syndrome and both of them received lead replacement.The incidence of complications during the perioperative period and follow-ups of the axillary vein group and the subclavian vein group was 1.6% (2/125) and 8.2% (10/122),respectively (x2=5.813,P =0.016).Conclusion:Optimized axillary vein technique may be superior to the conventional subclavian vein technique for CIED lead placement.

  8. Optimizing linkage and retention to hypertension care in rural Kenya (LARK hypertension study): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Vedanthan, Rajesh; Kamano, Jemima H; Naanyu, Violet; Delong, Allison K; Were, Martin C; Finkelstein, Eric A; Menya, Diana; Akwanalo, Constantine O; Bloomfield, Gerald S; Binanay, Cynthia A; Velazquez, Eric J; Hogan, Joseph W; Horowitz, Carol R; Inui, Thomas S; Kimaiyo, Sylvester; Fuster, Valentin

    2014-04-27

    Hypertension is the leading global risk factor for mortality. Hypertension treatment and control rates are low worldwide, and delays in seeking care are associated with increased mortality. Thus, a critical component of hypertension management is to optimize linkage and retention to care. This study investigates whether community health workers, equipped with a tailored behavioral communication strategy and smartphone technology, can increase linkage and retention of hypertensive individuals to a hypertension care program and significantly reduce blood pressure among them. The study will be conducted in the Kosirai and Turbo Divisions of western Kenya. An initial phase of qualitative inquiry will assess facilitators and barriers of linkage and retention to care using a modified Health Belief Model as a conceptual framework. Subsequently, we will conduct a cluster randomized controlled trial with three arms: 1) usual care (community health workers with the standard level of hypertension care training); 2) community health workers with an additional tailored behavioral communication strategy; and 3) community health workers with a tailored behavioral communication strategy who are also equipped with smartphone technology. The co-primary outcome measures are: 1) linkage to hypertension care, and 2) one-year change in systolic blood pressure among hypertensive individuals. Cost-effectiveness analysis will be conducted in terms of costs per unit decrease in blood pressure and costs per disability-adjusted life year gained. This study will provide evidence regarding the effectiveness and cost-effectiveness of strategies to optimize linkage and retention to hypertension care that can be applicable to non-communicable disease management in low- and middle-income countries. This trial is registered with (NCT01844596) on 30 April 2013.

  9. Optimal Subset Selection of Time-Series MODIS Images and Sample Data Transfer with Random Forests for Supervised Classification Modelling.

    Science.gov (United States)

    Zhou, Fuqun; Zhang, Aining

    2016-10-25

    Nowadays, various time-series Earth Observation data with multiple bands are freely available, such as Moderate Resolution Imaging Spectroradiometer (MODIS) datasets including 8-day composites from NASA, and 10-day composites from the Canada Centre for Remote Sensing (CCRS). It is challenging to efficiently use these time-series MODIS datasets for long-term environmental monitoring due to their vast volume and information redundancy. This challenge will be greater when Sentinel 2-3 data become available. Another challenge that researchers face is the lack of in-situ data for supervised modelling, especially for time-series data analysis. In this study, we attempt to tackle the two important issues with a case study of land cover mapping using CCRS 10-day MODIS composites with the help of Random Forests' features: variable importance, outlier identification. The variable importance feature is used to analyze and select optimal subsets of time-series MODIS imagery for efficient land cover mapping, and the outlier identification feature is utilized for transferring sample data available from one year to an adjacent year for supervised classification modelling. The results of the case study of agricultural land cover classification at a regional scale show that using only about a half of the variables we can achieve land cover classification accuracy close to that generated using the full dataset. The proposed simple but effective solution of sample transferring could make supervised modelling possible for applications lacking sample data.

  10. Construction and optimization of an efficient amplification method of a random ssDNA library by asymmetric emulsion PCR.

    Science.gov (United States)

    Shao, Keke; Shi, Xinhui; Zhu, Xiangjun; Cui, Leilei; Shao, Qixiang; Ma, Da

    2017-03-01

    Construction of a random ssDNA sublibrary is an important step of the aptamer screening process. The available construction methods include asymmetric PCR, biotin-streptavidin separation, and lambda exonuclease digestions, in which PCR amplification is a key step. The main drawback of PCR amplification is overamplification increasing nonspecific hybridization among different products and by-products, which may cause the loss of potential high-quality aptamers, inefficient screening, and even screening failure. Cycle number optimization in PCR amplification is the main way to avoid overamplification but does not fundamentally eliminate the nonspecific hybridization, and the decreased cycle number may lead to insufficient product amounts. Here, we developed a new method, "asymmetric emulsion PCR," which could overcome the shortcomings of conventional PCR. In asymmetric emulsion PCR, different templates were separated by emulsion particles, allowing single-molecule PCR, in which each template was separately amplified, and the nonspecific hybridization was avoided. Overamplification or formation of by-products was not observed. The method is so simple that direct amplification of 40 or more cycles can provide a high-quality ssDNA library. Therefore, the asymmetric emulsion PCR would improve the screening efficiency of systematic evolution of ligands by exponential enrichment. © 2015 The Authors. Biotechnology and Applied Biochemistry published by Wiley Periodicals, Inc. on behalf of the International Union of Biochemistry and Molecular Biology, Inc.

  11. Scaling and intermittency of brain events as a manifestation of consciousness

    Science.gov (United States)

    Paradisi, P.; Allegrini, P.; Gemignani, A.; Laurino, M.; Menicucci, D.; Piarulli, A.

    2013-01-01

    We discuss the critical brain hypothesis and its relationship with intermittent renewal processes displaying power-law decay in the distribution of waiting times between two consecutive renewal events. In particular, studies on complex systems in a "critical" condition show that macroscopic variables, integrating the activities of many individual functional units, undergo fluctuations with an intermittent serial structure characterized by avalanches with inverse-power-law (scale-free) distribution densities of sizes and inter-event times. This condition, which is denoted as "fractal intermittency", was found in the electroencephalograms of subjects observed during a resting state wake condition. It remained unsolved whether fractal intermittency correlates with the stream of consciousness or with a non-task-driven default mode activity, also present in non-conscious states, like deep sleep. After reviewing a method of scaling analysis of intermittent systems based of eventdriven random walks, we show that during deep sleep fractal intermittency breaks down, and reestablishes during REM (Rapid Eye Movement) sleep, with essentially the same anomalous scaling of the pre-sleep wake condition. From the comparison of the pre-sleep wake, deep sleep and REM conditions we argue that the scaling features of intermittent brain events are related to the level of consciousness and, consequently, could be exploited as a possible indicator of consciousness in clinical applications.

  12. DEMAND CATEGORISATION, FORECASTING, AND INVENTORY CONTROL FOR INTERMITTENT DEMAND ITEMS

    Directory of Open Access Journals (Sweden)

    E. Babiloni

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: It is commonly assumed that intermittent demand appears randomly, with many periods without demand; but that when it does appear, it tends to be higher than unit size. Basic and well-known forecasting techniques and stock policies perform very poorly with intermittent demand, making new approaches necessary. To select the appropriate inventory management policy, it is important to understand the demand pattern for the items, especially when demand is intermittent. The use of a forecasting method designed for an intermittent demand pattern, such as Croston’s method, is required instead of a simpler and more common approach such as exponential smoothing. The starting point is to establish taxonomic rules to select efficiently the most appropriate forecasting and stock control policy to cope with thousands of items found in real environments. This paper contributes to the state of the art in: (i categorisation of the demand pattern; (ii methods to forecast intermittent demand; and (iii stock control methods for items with intermittent demand patterns. The paper first presents a structured literature review to introduce managers to the theoretical research about how to deal with intermittent demand items in both forecasting and stock control methods, and then it points out some research gaps for future development for the three topics.

    AFRIKAANSE OPSOMMING: Daar word algemeen aanvaar dat intermitterende vraag op toevalswyse voorkom, met verskeie periodes waar daar geen vraag is nie. Wanneer die vraag dan wel materialiseer, oorskry dit dikwels die eenheidsgrootte. Die bekende vooruitskattingstegnieke en voorraadbeleidstellings het min sukses waar intermitterende vraag voorkom, sodat nuwe benaderings nodig is om die problem aan te spreek. Om ‘n geskikte voorraadbestuur-beleid te selekteer, is dit noodsaaklik om die vraagpatroon van die items te verstaan, juis in gevalle van intermitterende patrone. Die gebruik van

  13. 基于2层规划的间歇性分布式电源及无功补偿综合优化配置%Comprehensive Optimal Allocation of Intermittent Distributed Generation and Reactive Power Compensation Based on Bilevel Planning

    Institute of Scientific and Technical Information of China (English)

    郭金明; 李欣然; 邓威; 何春光; 刘卫健

    2013-01-01

    目前分布式风电(distributed wind generation, DWG)、光伏电池(photovoltaic, PV)等间歇性分布式电源(distributed generation, DG)优化配置对象单一而难以全面反映间歇性DG优化配置的综合效益,且不宜采用确定性的变量和约束来处理间歇性DG出力不确定性和波动性的问题,针对此状况,采用机会约束规划方法,基于随机潮流计算结果,建立2层优化配置模型,对间歇性DG和补偿电容进行综合优化配置,并选择带精英策略的遗传算法进行优化求解。算例结果表明,补偿电容的优化投切效益会影响间歇性DG和补偿电容的优化配置,而补偿电容的配置容量及其最大日允许投切次数、间歇性DG出力和负荷功率期望值的季节性变化对补偿电容的优化投切效益均有显著的影响。2层优化配置的最优方案在兼顾间歇性 DG 和补偿电容的规划经济效益与补偿电容优化投切效益的同时,还可利用补偿电容进一步改善系统的电压质量,从而获得经济效益与电压质量的综合最优,算例分析结果验证了该模型的有效性和合理性。%The optimal allocation of current distributed generations (DG) such as distributed wind generation (DWG) and photovoltaic (PV) is usually single-object oriented, as a result, it is hard to reflect overall benefits of intermittent DGs`optimal allocation. And it is also inappropriate to use fixed variables and constraints to handle the uncertainty and fluctuation of DGs` power output. Aiming to solve the problems, based on the calculation of probabilistic power flow, a bilevel optimal allocation model was established with opportunity-constrained planning method to carry out comprehensive optimal allocation of intermittent DGs and compensation capacitors. And genetic algorithm with elitist strategy was used for the optimal solution. Results of the example demonstrated that optimized operational benefit of

  14. Intermittent redesign of continuous controllers

    Science.gov (United States)

    Gawthrop, Peter J.; Wang, Liuping

    2010-08-01

    The reverse-engineering idea developed by Maciejowski in the context of model-based predictive control is applied to the redesign of continuous-time compensators as intermittent controllers. Not only does this give a way of designing constrained input and state versions of continuous-time compensators but also provides a method for turning continuous-time compensators into event-driven versions. The procedure is illustrated by three examples: an event-driven PID controller relevant to the human balance control problem, a constrained version of the classical mechanical vibration absorber of den Hartog and an event driven and constrained vibration absorber.

  15. Intermittent aeration to improve wastewater treatment efficiency in pilot-scale constructed wetland.

    Science.gov (United States)

    Uggetti, Enrica; Hughes-Riley, Theodore; Morris, Robert H; Newton, Michael I; Trabi, Christophe L; Hawes, Patrick; Puigagut, Jaume; García, Joan

    2016-07-15

    Forced aeration of horizontal subsurface flow constructed wetlands (HSSF CWs) is nowadays a recognized method to improve treatment efficiency, mainly in terms of ammonium removal. While numerous investigations have been reported testing constant aeration, scarce information can be found about the efficiency of intermittent aeration. This study aims at comparing continuous and intermittent aeration, establishing if there is an optimal regime that will increase treatment efficiency of HSSF CWs whilst minimizing the energy requirement. Full and intermittent aeration were tested in a pilot plant of three HSSF CWs (2.64m(2) each) fed with primary treated wastewater. One unit was fully aerated; one intermittently aerated (i.e. by setting a limit of 0.5mg/L dissolved oxygen within the bed) with the remaining unit not aerated as a control. Results indicated that intermittent aeration was the most successful operating method. Indeed, the coexistence of aerobic and anoxic conditions promoted by the intermittent aeration resulted in the highest COD (66%), ammonium (99%) and total nitrogen (79%) removals. On the other hand, continuous aeration promotes ammonium removal (99%), but resulted in nitrate concentrations in the effluent of up to 27mg/L. This study demonstrates the high potential of the intermittent aeration to increase wastewater treatment efficiency of CWs providing an extreme benefit in terms of the energy consumption.

  16. Treatment, rationale, and study design of TALISMAN study: a randomized phase II open-label study of second-line erlotinib versus intermittent erlotinib dosing with docetaxel in the treatment of former-smoker men affected by recurrent squamous non-small-cell lung cancer.

    Science.gov (United States)

    Gridelli, Cesare; Rossi, Antonio; Venturino, Paola; de Marinis, Filippo

    2011-01-01

    We present the treatment rationale and study design of the TALISMAN (TArceva and docetaxeL In former-Smokers MAle patients with recurrent Non-small-cell lung cancer) study, an open-label, randomized phase II trial of erlotinib (arm A) or intermittent erlotinib and docetaxel (arm B) in male former smokers affected by recurrent squamous non-small-cell lung cancer (NSCLC). In arm A, treatment consists of erlotinib 150 mg daily orally until progression or inacceptable toxicity; in arm B, treatment consists of docetaxel 75 mg/m² on day 1 and erlotinib 150 mg orally on days 2-16, recycled every 3 weeks up to 4 cycles followed, in patients not progressed, by erlotinib 150 mg daily orally until disease progression or inacceptable toxicity. The primary endpoint of this study is the rate of patients without progression at 6 months, and secondary objectives include median progression-free survival, median overall survival, activity, and toxicity. In addition, translational research evaluating EGFR and KRAS mutational status will be investigated for both arms.

  17. The effects of a psychological intervention directed at optimizing immune function: study protocol for a randomized controlled trial.

    Science.gov (United States)

    Schakel, Lemmy; Veldhuijzen, Dieuwke S; van Middendorp, Henriët; Prins, Corine; Joosten, Simone A; Ottenhoff, Tom H M; Visser, Leo G; Evers, Andrea W M

    2017-05-26

    Previous research has provided evidence for the link between psychological processes and psychophysiological health outcomes. Psychological interventions, such as face-to-face or online cognitive behavioral therapy (CBT) and serious games aimed at improving health, have shown promising results in promoting health outcomes. Few studies so far, however, have examined whether Internet-based CBT combined with serious gaming elements is effective in modulating health outcomes. Moreover, studies often did not incorporate psychophysiological or immunological challenges in order to gain insight into physiological responses to real-life challenges after psychological interventions. The overall aim of this study is to investigate the effects of a psychological intervention on self-reported and physiological health outcomes in response to immune and psychophysiological challenges. In a randomized controlled trial, 60 healthy men are randomly assigned to either an experimental condition, receiving guided Internet-based (e-health) CBT combined with health-related serious gaming elements for 6 weeks, or a control condition receiving no intervention. After the psychological intervention, self-reported vitality is measured, and participants are given an immunological challenge in the form of a Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccination. One day after the vaccination, participants are asked to perform several psychophysiological tasks in order to explore the effects of the psychological intervention on participants' stress response following the immune challenge. To assess the delayed effects of vaccination on self-reported and physiological health outcomes, a follow-up visit is planned 4 weeks later. Total study duration is approximately 14 weeks. The primary outcome measure is self-reported vitality measured directly after the intervention. Secondary outcome measures include inflammatory and endocrine markers, as well as psychophysiological measures of

  18. Intermittent hypoxia and isoniazid plus rifampicin affect hepatic ultrastructure in mice

    Institute of Scientific and Technical Information of China (English)

    WU Run-hua; ZENG Yi-ming; CHEN Xiao-yang

    2011-01-01

    Background Chronic intermittent hypoxia is the most important pathophysiologic feature of sleep apnea syndrome.The present study aimed to determine whether chronic intermittent hypoxia,which is associated with sleep apnea syndrome,can cause or increase damage to liver cell ultrastructure induced by isoniazid and rifampicin in mice.Methods Based on a 2x2 full factorial design consisting of two factors of chronic intermittent hypoxia and isoniazid plus rifampicin,32 male C57B6J mice were randomized into the control group,the chronic intermittent hypoxia group,the isoniazid plus rifampicin group,and the chronic intermittent hypoxia + isoniazid plus rifampicin group.Twelve weeks after treatment,we examined the ultrastructure of liver cells and quantitatively analyzed mitochondrial morphology in C57B6J mice.Results Chronic intermittent hypoxia did not significantly affect the ultrastructure of liver cells.The main effect of chronic intermittent hypoxia did not lead to an increase of mean profile area or mean perimeter of mitochondria,and a decrease of numerical density on area of mitochondria (all P >0.05).Isoniazid plus rifampicin significantly affected liver cell ultrastructure.The main effect of isoniazid plus rifampicin resulted in an increase of mean profile area and mean perimeter of mitochondria,and a decrease of numerical density on area of mitochondria (all P <0.05).Moreover,there was a positive interaction among the chronic intermittent hypoxia and the isoniazid plus rifampicin groups for mean profile area,mean perimeter,and numerical density on area of mitochondria (all P<0.05).Conclusion Chronic intermittent hypoxia and isoniazid plus rifampicin treatment lead to synergistic liver cell ultrastructural injury.

  19. International Study to Predict Optimized Treatment for Depression (iSPOT-D, a randomized clinical trial: rationale and protocol

    Directory of Open Access Journals (Sweden)

    Cooper Nicholas J

    2011-01-01

    Full Text Available Abstract Background Clinically useful treatment moderators of Major Depressive Disorder (MDD have not yet been identified, though some baseline predictors of treatment outcome have been proposed. The aim of iSPOT-D is to identify pretreatment measures that predict or moderate MDD treatment response or remission to escitalopram, sertraline or venlafaxine; and develop a model that incorporates multiple predictors and moderators. Methods/Design The International Study to Predict Optimized Treatment - in Depression (iSPOT-D is a multi-centre, international, randomized, prospective, open-label trial. It is enrolling 2016 MDD outpatients (ages 18-65 from primary or specialty care practices (672 per treatment arm; 672 age-, sex- and education-matched healthy controls. Study-eligible patients are antidepressant medication (ADM naïve or willing to undergo a one-week wash-out of any non-protocol ADM, and cannot have had an inadequate response to protocol ADM. Baseline assessments include symptoms; distress; daily function; cognitive performance; electroencephalogram and event-related potentials; heart rate and genetic measures. A subset of these baseline assessments are repeated after eight weeks of treatment. Outcomes include the 17-item Hamilton Rating Scale for Depression (primary and self-reported depressive symptoms, social functioning, quality of life, emotional regulation, and side-effect burden (secondary. Participants may then enter a naturalistic telephone follow-up at weeks 12, 16, 24 and 52. The first half of the sample will be used to identify potential predictors and moderators, and the second half to replicate and confirm. Discussion First enrolment was in December 2008, and is ongoing. iSPOT-D evaluates clinical and biological predictors of treatment response in the largest known sample of MDD collected worldwide. Trial registration International Study to Predict Optimised Treatment - in Depression (iSPOT-D ClinicalTrials.gov Identifier

  20. Radiation characteristics of intermittence exhaust noise

    Institute of Scientific and Technical Information of China (English)

    ZHAO Shengdun; SHANG Chunyang; ZHAO Zhigang; SHI Weixiang

    2000-01-01

    Aerodynamic characteristics, the noise characteristics in the course of intermittence exhaust are investigated and the expressions for sound pressure level of the noise generated by single-pole source and quadrupole source in the intermittence exhaust noise are established. The effects of all parameters in pneumatic system on the noise are also comprehensively studied.

  1. COHO SALMON DEPENDENCE ON INTERMITTENT STREAMS

    Science.gov (United States)

    In February 2006, the US Supreme Court heard cases that may affect whether intermittent streams are jurisdictional waters under the Clean Water Act. In June 2006, however, the cases were remanded to the circuit court, leaving the status of intermittent streams uncertain once agai...

  2. On the effect of intermittency of turbulence on the parabolic relation between skewness and kurtosis in magnetized plasmas

    CERN Document Server

    Guszejnov, Dávid; Zoletnik, Sándor; Lazányi, Nóra

    2014-01-01

    This paper is aimed to contribute to the scientific discussions that have been triggered by the experimental observation of a quadratic relation between the kurtosis and skewness of turbulent fluctuations present in fusion plasmas and other nonlinear physical systems. In this paper we offer a general statistical model which attributes the observed $K = aS^2 + b$ relation to the varying intermittency of the experimental signals. The model is a two random variable model constructed to catch the essential intermittent feature of the real signal. One of the variables is the amplitude of the underlying intermittent event (e.g. turbulent structure) while the other is connected to the intermittency level of the system. This simple model can attribute physical meaning to the $a$ and $b$ coefficients, as they characterize the spatio-temporal statistics of intermittent events. By constructing a particle-conserving Gaussian model for the underlying coherent structures the experimentally measured $a$ and $b$ coefficients...

  3. Kinetic intermittency in magnetized plasma turbulence

    CERN Document Server

    Teaca, Bogdan; Told, Daniel; Jenko, Frank

    2016-01-01

    We employ magnetized plasma turbulence, described by a gyrokinetic formalism in an interval ranging from the end of the fluid scales to the electron gyroradius, to introduce the first study of kinetic intermittency, in which nonlinear structures formed directly in the distribution functions are analyzed by accounting for velocity space correlations generated by linear (Landau resonance) and nonlinear phase mixing. Electron structures are found to be strongly intermittent and dominated by linear phase mixing, while nonlinear phase mixing dominates the weakly intermittent ions. This is the first time spatial intermittency and linear phase mixing are shown to be self-consistently linked for the electrons and, as the magnetic field follows the intermittency of the electrons at small scales, explain why magnetic islands are places dominated by Landau damping in steady state turbulence.

  4. Optical diagnostics of intermittent flows

    DEFF Research Database (Denmark)

    Okulov, V.L.; Naumov, I.V.; Sørensen, Jens Nørkær

    2007-01-01

    The efficiency of combined use of different optical techniques for flow diagnostics is demonstrated with the practically important case of intense swirling flows. It is shown that, when applied separately, commonly used optical measuring techniques, such as laser Doppler anemometry and particle...... image velocimetry, frequently give erroneous results, especially for the transition flow and developed nonstationary flow. However, their combined use in diagnostics of unsteady (intermittent) flows significantly improves both the temporal and spatial resolution of measurements. Such a complex approach...... is for the first time applied for diagnostics of the flow pattern in a closed cylinder with a rotating end face with the aim of studying the changeover from the steady axisymmetric to unsteady asymmetric flow over a wide range of flow parameters. It is found that such a transition is notable for azimuthal...

  5. Intermittent transport in edge plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, O.E.; Naulin, V.; Nielsen, A.H.; Juul Rasmussen, J. [Association EURATOM-Riso National Laboratory, Optics and Plasma Research, Roskilde (Denmark)

    2004-07-01

    The properties of low-frequency convective fluctuations and transport are investigated for the boundary region of magnetized plasmas. We employ a two-dimensional fluid model for the evolution of the global plasma quantities in a geometry and with parameters relevant to the scrape-off layer of confined toroidal plasmas. Strongly intermittent plasma transport is regulated by self-consistently generated sheared poloidal flows and is mediated by burst ejection of particles and heat from the bulk plasma in the form of blobs. Coarse grained probe signals reveal a highly skewed and flat distribution on short time scales, but tends towards a normal distribution at large time scales. Conditionally averaged signals are in perfect agreement with experimental measurements. (authors)

  6. Intermittent dystonia in Hartnup disease.

    Science.gov (United States)

    Darras, B T; Ampola, M G; Dietz, W H; Gilmore, H E

    1989-01-01

    A 6-month-old girl developed intermittent dystonic posture of the legs and eczematous dermatitis without ataxia. Qualitative and quantitative urine amino acid testing confirmed the diagnosis of Hartnup disease. Cranial computed tomography, electroencephalogram, electromyogram/nerve conduction study, posterior tibial somatosensory evoked potentials, 24-hour electroencephalographic telemetry, and metrizamide myelogram were normal. Spinal fluid hydroxy-indoleacetic acid concentration was less than or equal to 2 S.D. of normal; oral tryptophan loading (70 mg/kg) resulted in a two-fold rise in cerebrospinal fluid 5-hydroxy-indoleacetic acid concentration. Tryptophan administered alone or with nicotinic acid failed to improve the dystonia; however, trihexyphenidyl (1-2 mg/kg/day) dramatically improved it. Hartnup disease should be considered in children with unexplained dystonia.

  7. Lattice splitting under intermittent flows

    CERN Document Server

    Schläpfer, Markus

    2010-01-01

    We study the splitting of regular square lattices subject to stochastic intermittent flows. By extensive Monte Carlo simulations we reveal how the time span until the occurence of a splitting depends on various flow patterns imposed on the lattices. Increasing the flow fluctuation frequencies shortens this time span which reaches a minimum before rising again due to inertia effects incorporated in the model. The size of the largest connected component after the splitting is rather independent of the flow fluctuations but sligthly decreases with the link capacities. Our results are relevant for assessing the robustness of real-life systems, such as electric power grids with a large share of renewable energy sources including wind turbines and photovoltaic systems.

  8. Autonomous change of behavior for environmental context: An intermittent search model with misunderstanding search pattern

    Science.gov (United States)

    Murakami, Hisashi; Gunji, Yukio-Pegio

    2017-07-01

    Although foraging patterns have long been predicted to optimally adapt to environmental conditions, empirical evidence has been found in recent years. This evidence suggests that the search strategy of animals is open to change so that animals can flexibly respond to their environment. In this study, we began with a simple computational model that possesses the principal features of an intermittent strategy, i.e., careful local searches separated by longer steps, as a mechanism for relocation, where an agent in the model follows a rule to switch between two phases, but it could misunderstand this rule, i.e., the agent follows an ambiguous switching rule. Thanks to this ambiguity, the agent's foraging strategy can continuously change. First, we demonstrate that our model can exhibit an optimal change of strategy from Brownian-type to Lévy-type depending on the prey density, and we investigate the distribution of time intervals for switching between the phases. Moreover, we show that the model can display higher search efficiency than a correlated random walk.

  9. Prevention of Stress Related Mucosal Disease with Intermittent

    Directory of Open Access Journals (Sweden)

    Farshid Rahimi-Bashar

    2015-10-01

    Full Text Available Background: This study aimed to compare intermittent intravenous (IV pantoprazole and ranitidine for control of gastric acid secretion and the possible prevention of Upper Gastrointestinal Bleeding (UGIB in critical care patients.Methods: This was a randomized, double blind clinical trial study of IV pantoprazole (40 mg every12 hour or intermittent IV ranitidine (50 mg bolus every 8 hour in patients at risk for UGIB. The primary endpoint was gastric pH. UGIB was measured as secondary endpoint.Results: ninety two Critical care patients were enrolled. Gastric pH was well controlled by two study drugs. Gastric pH increased in pantoprazole group than in the ranitidine group (4.40±0.39 versus 3.32±0.28; P=0.000. Upper GI bleeding was higher in ranitidine group than pantoprazole group (4/46 versus 2/46; P=0.404.Conclusion: This  study  indicates  that  intermittent  IV pantoprazole  compared  with  bolus  IV ranitidine, more effectively controls gastric pH and may prevent UGIB in high risk critical care patients without the development of tolerance.

  10. The influence of respiratory muscle training upon intermittent exercise performance.

    Science.gov (United States)

    Nicks, C R; Morgan, D W; Fuller, D K; Caputo, J L

    2009-01-01

    The purpose of this study was to determine the effect of respiratory muscle training (RMT) on intermittent exercise performance, respiratory muscle strength (PI (max)), respiratory muscle fatigue (RMF), and dyspnea in soccer athletes. Collegiate soccer athletes (20 male, 7 female) were randomly divided into either a RMT or control condition during off-season conditioning. The RMT group performed a 30RM protocol (10 times weekly) for 5 weeks using a commercially-available training device, while the controls received no RMT. Performance was evaluated utilizing Level 1 of the Yo-Yo Intermittent Recovery Test (IRT) and dyspnea was assessed during and immediately following the IRT. RMF was quantified within 2 minutes (RMF2) and 10 minutes (RMF10) after completing the IRT. Following training, the RMT group significantly increased IRT performance by 216.6 +/- 231.0 meters (p = .008) while the 49.2 +/- 75.1 meter increase observed in the controls was not significant. PI (max) in the RMT group increased from 138.1 +/- 19.6 to 165.3 +/- 23.5 cmH (2)O (p RMT did not significantly affect RMF or dyspnea. In conclusion, RMT improved intermittent exercise performance in these soccer athletes. The mechanisms by which RMT improves performance warrant further study.

  11. Analytical approach to continuous and intermittent bottleneck flows

    DEFF Research Database (Denmark)

    Helbing, D.; Johansson, A.; Mathiesen, Joachim Kaj;

    2006-01-01

    Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20......Many-particle-inspired theory, Continuous and Intermittent Bottleneck Flows Udgivelsesdato: Oct. 20...

  12. Defining the Optimal Planning Target Volume in Image-Guided Stereotactic Radiosurgery of Brain Metastases: Results of a Randomized Trial

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, John P., E-mail: john.kirkpatrick@dm.duke.edu [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Surgery, Duke University, Durham, North Carolina (United States); Wang, Zhiheng [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Sampson, John H. [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Department of Surgery, Duke University, Durham, North Carolina (United States); McSherry, Frances; Herndon, James E. [Department of Biostatistics and Bioinformatics, Duke University, Durham, North Carolina (United States); Allen, Karen J.; Duffy, Eileen [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States); Hoang, Jenny K. [Department of Radiology, Duke University, Durham, North Carolina (United States); Chang, Zheng; Yoo, David S.; Kelsey, Chris R.; Yin, Fang-Fang [Department of Radiation Oncology, Duke University, Durham, North Carolina (United States)

    2015-01-01

    Purpose: To identify an optimal margin about the gross target volume (GTV) for stereotactic radiosurgery (SRS) of brain metastases, minimizing toxicity and local recurrence. Methods and Materials: Adult patients with 1 to 3 brain metastases less than 4 cm in greatest dimension, no previous brain radiation therapy, and Karnofsky performance status (KPS) above 70 were eligible for this institutional review board–approved trial. Individual lesions were randomized to 1- or 3- mm uniform expansion of the GTV defined on contrast-enhanced magnetic resonance imaging (MRI). The resulting planning target volume (PTV) was treated to 24, 18, or 15 Gy marginal dose for maximum PTV diameters less than 2, 2 to 2.9, and 3 to 3.9 cm, respectively, using a linear accelerator–based image-guided system. The primary endpoint was local recurrence (LR). Secondary endpoints included neurocognition Mini-Mental State Examination, Trail Making Test Parts A and B, quality of life (Functional Assessment of Cancer Therapy-Brain), radionecrosis (RN), need for salvage radiation therapy, distant failure (DF) in the brain, and overall survival (OS). Results: Between February 2010 and November 2012, 49 patients with 80 brain metastases were treated. The median age was 61 years, the median KPS was 90, and the predominant histologies were non–small cell lung cancer (25 patients) and melanoma (8). Fifty-five, 19, and 6 lesions were treated to 24, 18, and 15 Gy, respectively. The PTV/GTV ratio, volume receiving 12 Gy or more, and minimum dose to PTV were significantly higher in the 3-mm group (all P<.01), and GTV was similar (P=.76). At a median follow-up time of 32.2 months, 11 patients were alive, with median OS 10.6 months. LR was observed in only 3 lesions (2 in the 1 mm group, P=.51), with 6.7% LR 12 months after SRS. Biopsy-proven RN alone was observed in 6 lesions (5 in the 3-mm group, P=.10). The 12-month DF rate was 45.7%. Three months after SRS, no significant change in

  13. Three hours of intermittent hypoxia increases circulating glucose levels in healthy adults.

    Science.gov (United States)

    Newhouse, Lauren P; Joyner, Michael J; Curry, Timothy B; Laurenti, Marcello C; Man, Chiara Dalla; Cobelli, Claudio; Vella, Adrian; Limberg, Jacqueline K

    2017-01-01

    An independent association exists between sleep apnea and diabetes. Animal models suggest exposure to intermittent hypoxia, a consequence of sleep apnea, results in altered glucose metabolism and fasting hyperglycemia. However, it is unknown if acute exposure to intermittent hypoxia increases glucose concentrations in nondiabetic humans. We hypothesized plasma glucose would be increased from baseline following 3 h of intermittent hypoxia in healthy humans independent of any effect on insulin sensitivity. Eight (7M/1F, 21-34 years) healthy subjects completed two study visits randomized to 3 h of intermittent hypoxia or continuous normoxia, followed by an oral glucose tolerance test. Intermittent hypoxia consisted of 25 hypoxic events per hour where oxygen saturation (SpO2) was significantly reduced (Normoxia: 97 ± 1%, Hypoxia: 90 ± 2%, P  0.05). In contrast, circulating glucose concentrations were increased after 3 h of intermittent hypoxia when compared to baseline (5.0 ± 0.2 vs. 5.3 ± 0.2 mmol/L, P = 0.01). There were no detectable changes in insulin sensitivity following intermittent hypoxia when compared to continuous normoxia, as assessed by the oral glucose tolerance test (P > 0.05). Circulating glucose is increased after 3 h of intermittent hypoxia in healthy humans, independent of any lasting changes in insulin sensitivity. These novel findings could explain, in part, the high prevalence of diabetes in patients with sleep apnea and warrant future studies to identify underlying mechanisms.

  14. Assessing Relative Volatility/Intermittency/Energy Dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko; Schmiegel, Jürgen

    We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency even when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... process in particular. While this estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, we apply it also to energy price data. Moreover, we develop a probabilistic asymptotic theory for relative power variations of Brownian semistationary...... processes and Ito semimartingales and discuss how it can be used for inference on relative volatility/intermittency....

  15. Prevention of urethral stricture recurrence using clean intermittent self-catheterization

    DEFF Research Database (Denmark)

    Kjaergaard, B; Walter, S; Bartholin, J;

    1994-01-01

    OBJECTIVE: To investigate the effect of clean intermittent catheterization (CIC) on prevention of urethral stricture recurrence after internal urethrotomy. PATIENTS AND METHODS: Of 55 men who were randomly selected, 43 completed the investigation. Of these, 21 patients performed CIC weekly for 1...

  16. A botanical compound, Padma 28, increases walking distance in stable intermittent claudication

    DEFF Research Database (Denmark)

    Drabaek, H; Mehlsen, J; Himmelstrup, H;

    1993-01-01

    Thirty-six patients with a median age of sixty-seven years and a median duration of intermittent claudication of five years were randomized to either active treatment with Padma 28 or placebo. The effect of treatment was quantified by measurements of systemic and peripheral systolic blood pressur...

  17. Double-blind, controlled, multicenter study of indobufen versus placebo in patients with intermittent claudication

    DEFF Research Database (Denmark)

    Tönnesen, K H; Albuquerque, P; Baitsch, G;

    1993-01-01

    The objective of the study was to evaluate the efficacy and safety of indobufen compared with placebo in the treatment of moderately severe intermittent claudication. The study consisted of a four-week single-blind, placebo-controlled run-in phase, followed by a six-month double-blind randomized ...

  18. Human control of an inverted pendulum: is continuous control necessary? Is intermittent control effective? Is intermittent control physiological?

    Science.gov (United States)

    Loram, Ian D; Gollee, Henrik; Lakie, Martin; Gawthrop, Peter J

    2011-01-15

    Human motor control is often explained in terms of engineering 'servo' theory. Recently, continuous, optimal control using internal models has emerged as a leading paradigm for voluntary movement. However, these engineering paradigms are designed for high band-width, inflexible, consistent systems whereas human control is low bandwidth and flexible using noisy sensors and actuators. By contrast, engineering intermittent control was designed for bandwidth-limited applications. Our general interest is whether intermittent rather than continuous control is generic to human motor control. Currently, it would be assumed that continuous control is the superior and physiologically natural choice for controlling unstable loads, for example as required for maintaining human balance. Using visuo-manual tracking of an unstable load, we show that control using gentle, intermittent taps is entirely natural and effective. The gentle tapping method resulted in slightly superior position control and velocity minimisation, a reduced feedback time delay, greater robustness to changing actuator gain and equal or greater linearity with respect to the external disturbance. Control was possible with a median contact rate of 0.8±0.3 s(-1). However, when optimising position or velocity regulation, a modal contact rate of 2 s(-1) was observed. This modal rate was consistent with insignificant disturbance-joystick coherence beyond 1-2 Hz in both tapping and continuous contact methods. For this load, these results demonstrate a motor control process of serial ballistic trajectories limited to an optimum rate of 2 s(-1). Consistent with theoretical reasoning, our results suggest that intermittent open loop action is a natural consequence of human physiology.

  19. Sky dancer: an intermittent system

    Science.gov (United States)

    Cros, Anne; Rodríguez Romero, Jesse Alexander; Damián Díaz Andrade, Oscar

    2009-11-01

    Sky dancers attract people sight to make advertising. What is the origin of those large vertical tubes fluctuations above an air blower? This study complements the previous one [1] about the system analysis from a dynamical system point of view. As a difference from the ``garden hose-instability'' [2], the tube shape has got ``break points''. Those ``break points'' separate the air-filled bottom tube portion from its deflated top portion. We record the tube dynamics with a high-speed videocamera simultaneously that we measure the pressure at the air blower exit. The intermittent pressure evolution displays picks when the tube fluctuates. We compare those overpressure values with the ones that appears in a rigid tube whose exit is partially obstructed. [1] F. Castillo Flores & A. Cros ``Transition to chaos of a vertical collapsible tube conveying air flow'' J. Phys.: Conf. Ser. 166, 012017 (2009). [2] A. S. Greenwald & J. Dungundji ``Static and dynamic instabilities of a propellant line'' MIT Aeroelastic and Structures Research Lab, AFOSR Sci. Report: AFOSR 67-1395 (1967).

  20. An approach for evaluating the impact of an intermittent renewable energy source on transmission expansion planning

    Institute of Scientific and Technical Information of China (English)

    Rongrit CHATTHAWORN; Surachai CHAITUSANEY

    2015-01-01

    We propose a new robust optimization approach to evaluate the impact of an intermittent renewable energy source on transmission expansion planning (TEP). The objective function of TEP is composed of the investment cost of the transmission line and the operating cost of conventional generators. A method to select suitable scenarios representing the intermittent renewable energy generation and loads is proposed to obtain robust expansion planning for all possible scenarios. A meta-heuristic algorithm called adaptive tabu search (ATS) is employed in the proposed TEP. ATS iterates between the main problem, which minimizes the investment and operating costs, and the subproblem, which minimizes the cost of power generation from conventional generators and curtailments of renewable energy generation and loads. The subproblem is solved by nonlinear programming (NLP) based on an interior point method. Moreover, the impact of an intermittent renewable energy source on TEP was evaluated by comparing expansion planning with and without consideration of a renewable energy source. The IEEE Reliability Test System 79 (RTS 79) was used for testing the proposed method and evaluating the impact of an intermittent renewable energy source on TEP. The results show that the proposed robust optimization approach provides a more robust solution than other methods and that the impact of an intermittent renewable energy source on TEP should be considered.

  1. Intermittent chaotic chimeras for coupled rotators

    DEFF Research Database (Denmark)

    Olmi, Simona; Martens, Erik Andreas; Thutupalli, Shashi

    2015-01-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other...

  2. Improved Intermittency Analysis of Single Event Data

    OpenAIRE

    Janik, R. A.; Ziaja, B.

    1998-01-01

    The intermittency analysis of single event data (particle moments) in multiparticle production is improved, taking into account corrections due to the reconstruction of history of a particle cascade. This approach is tested within the framework of the $\\alpha$-model.

  3. On-line intermittent connector anomaly detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper investigates a non-traditional use of differential current sensor and current sensor to detect intermittent disconnection problems in connectors. An...

  4. Beneficial effects of intermittent suction and pressure treatment in intermittent claudication

    DEFF Research Database (Denmark)

    Mehlsen, J; Himmelstrup, H; Himmelstrup, Bodil

    1993-01-01

    The present study reports on the effects of a physical treatment modality in patients with intermittent claudication. During this treatment a major part of the skin surface is subjected to intermittent suction and pressure. In a previous, preliminary study the authors found a beneficial effect...... administration. The treatment caused significant increments in the ADP thresholds for platelet aggregation, while the effects on fibrinolysis were uncertain. It is concluded that intermittent suction and pressure treatment offers a new approach for conservative treatment of intermittent claudication....

  5. Lacunarity and intermittency in fluid turbulence

    Science.gov (United States)

    Smith, L. A.; Fournier, J.-D.; Spiegel, E. A.

    1986-01-01

    It is shown that oscillations in the high-order moments of turbulent velocity fields are inherent to the fractal character of intermittent turbulence and are a feature of the lacunarity of fractal sets. Oscillations in simple Cantor sets are described, and a single parameter to measure lacunarity is identified. The connection between oscillations in fractals and in the turbulent velocity correlations is discussed using the phenomenological beta model of intermittent turbulence (Frisch et al., 1978).

  6. Low nitrous oxide production in intermittent-feed high performance nitritating reactors

    DEFF Research Database (Denmark)

    Su, Qingxian; Jensen, Malene M.; Smets, Barth F.

    was converted to nitrite, with the average total net N2O production of 2.1 ± 0.7% of the ammonium oxidized. Operation with intermittent feeding appears an effective optimization approach to mitigate N2O emissions from nitritating systems. Net N2O production rates transiently increased with a rise in pH after...

  7. Effect of detailed information in the minority game: optimality of 2-day memory and enhanced efficiency due to random exogenous data

    Science.gov (United States)

    Sasidevan, V.

    2016-07-01

    In the minority game (MG), an odd number of heterogeneous and adaptive agents choose between two alternatives and those who end up on the minority side win. When the information available to the agents to make their choice is the identity of the minority side for the past m days, it is well-known that the emergent coordination among the agents is maximum when m∼ {{log}2}(N) . The optimal memory-length thus increases with the system size. In this work we show that, in MG when the information available to the agents to make their choice is the strength of the minority side for the past m days, the optimal memory length for the agents is always two (m  =  2) for large enough system sizes. The system is inefficient for m  =  1 and converges to random choice behaviour for m>2 for large N. Surprisingly, providing the agents with uniformly and randomly sampled m  =  1 exogenous information results in an increase in coordination between them compared to the case of endogenous information with any value of m. This is in stark contrast to the conventional MG, where agent’s coordination is invariant or gets worse with respect to such random exogenous information.

  8. OPTIMIZING OVERALL FUNCTION OF THE UPPER LIMB IS EFFECTIVE TREATMENT FOR SHOULDER PAIN IN INDIVIDUALS WITH STROKE: A RANDOMIZED CONTROLLED TRIAL

    Directory of Open Access Journals (Sweden)

    Mohamed E Khallaf, PhD PT

    2014-04-01

    Full Text Available Background: Shoulder pain is frequent after stroke and interferes with the rehabilitative process and functional outcomes. Treatments used for post-stroke shoulder pain are limited and largely ineffective. Objectives: This randomized controlled study was conducted to study the effect of optimizing overall function of upper limb on the basis of pathomechanics and motor relearning as a treatment of hemiparetic shoulder pain. Subjects and methods: Thirty patients with first ever stroke suffering shoulder pain on movement and at rest were included in this study. Pain was measured by the Visual Analogue Scale (VAS and Chedoke-McMaster Stroke Assessment (CMSA was used for measuring motor recovery and functional level. Shoulder abduction, flexion and external rotation ranges of motion (ROM were also measured. The participants were randomly assigned into two equal groups (G1 and G2. Those in G1 received an exercise therapy based on optimizing overall function of upper limb as a treatment of hemiparetic shoulder pain. Shoulder range of motion exercises were done for the patients represented G2. Treatments were applied for twelve weeks 5 times per week for 60 minutes. Results: shoulder pain and motor recovery scores improved significantly in addition to a significant increase in the shoulder ROMs (p < 0.05. Conclusion: These results suggest that exercise therapy which emphasize interrelationship of all areas of the upper limb to optimize overall function exerts positive effects on shoulder pain and functional recovery in participants with stroke.

  9. Muscle involvement during intermittent contraction patterns with different target force feedback modes

    DEFF Research Database (Denmark)

    Sjøgaard, G; Jørgensen, L V; Ekner, D

    2000-01-01

    and following 30 min of intermittent contractions showed larger fatigue development with proprioceptive feedback than visual feedback. Also rating of perceived exertion increased more during proprioceptive feedback than visual feedback. This may in part be explained by small differences in the mechanics during...... timing and force level is generally not specified. DESIGN: Repeated measure design in which six subjects in randomized order performed two experimental conditions only differing in feedback mode. METHODS: Intermittent static elbow flexion was performed against either a fixed-force transducer (visual...... and consequently the development muscle fatigue and disorders....

  10. Noise-driven activation in human intermittent control: a double-well potential model

    CERN Document Server

    Zgonnikov, Arkady

    2014-01-01

    In controlling unstable systems humans switch intermittently between the passive and active behavior instead of controlling the system in a continuous manner. The notion of noise-driven control activation provides a richer alternative to the conventional threshold-based models of intermittent motor control. The present study represents the control activation as a random walk in a continuously changing double-well potential. The match between the proposed model and the previous data on human balancing of virtual stick prompts that the double-well approach can aid in explaining complex dynamics of human behavior in control processes.

  11. A conditional simulation model of intermittent rain fields

    Directory of Open Access Journals (Sweden)

    L. G. Lanza

    2000-01-01

    Full Text Available The synthetic generation of random fields with specified probability distribution, correlation structure and probability of no-rain areas is used as the basis for the formulation of a stochastic space-time rainfall model conditional on rain gauge observations. A new procedure for conditioning while preserving intermittence is developed to provide constraints to Monte Carlo realisations of possible rainfall scenarios. The method addresses the properties of the convolution operator involved in generating random field realisations and is actually independent of the numerical algorithm used for unconditional simulation. It requires only the solution of a linear system of algebraic equations the order of which is given by the number of the conditioning nodes. Applications of the methodology are expected in rainfall field reconstruction from sparse rain gauge data and in rainfall downscaling from the large scale information that may be provided by remote sensing devices or numerical weather prediction models. Keywords: Space-time rainfall; Conditioning; Stochastic models

  12. Optimal Decisions in a Single-Period Supply Chain with Price-Sensitive Random Demand under a Buy-Back Contract

    Directory of Open Access Journals (Sweden)

    Feng Wang

    2014-01-01

    Full Text Available This paper studies a single-period supply chain with a buy-back contract under a Stackelberg game model, in which the supplier (leader decides on the wholesale price, and the retailer (follower responds to determine the retail price and the order quantity. We analytically investigate the decentralized retailer’s optimal decision. Our results demonstrate that the retailer has a unique optimal simultaneous decision on the retail price and the order quantity, under a mild restriction on the demand distribution. Moreover, as it can be shown that the decentralized supply chain facing price-sensitive random demand cannot be coordinated with buy-back contract, we propose a scheme for the system to achieve Pareto-improvement. Theoretical analysis suggests that there exists a unique Pareto-equilibrium for the supply chain. In particular, when the Pareto-equilibrium is reached, the supply chain is coordinated. Numerical experiments confirm our results.

  13. Automatised selection of load paths to construct reduced-order models in computational damage micromechanics: from dissipation-driven random selection to Bayesian optimization

    Science.gov (United States)

    Goury, Olivier; Amsallem, David; Bordas, Stéphane Pierre Alain; Liu, Wing Kam; Kerfriden, Pierre

    2016-08-01

    In this paper, we present new reliable model order reduction strategies for computational micromechanics. The difficulties rely mainly upon the high dimensionality of the parameter space represented by any load path applied onto the representative volume element. We take special care of the challenge of selecting an exhaustive snapshot set. This is treated by first using a random sampling of energy dissipating load paths and then in a more advanced way using Bayesian optimization associated with an interlocked division of the parameter space. Results show that we can insure the selection of an exhaustive snapshot set from which a reliable reduced-order model can be built.

  14. Optimal Systolic Blood Pressure Target After SPRINT: Insights from a Network Meta-Analysis of Randomized Trials.

    Science.gov (United States)

    Bangalore, Sripal; Toklu, Bora; Gianos, Eugenia; Schwartzbard, Arthur; Weintraub, Howard; Ogedegbe, Gbenga; Messerli, Franz H

    2017-06-01

    The optimal on-treatment blood pressure (BP) target has been a matter of debate. The recent SPRINT trial showed significant benefits of a BP target of targets. Trial arms were grouped into 5 systolic BP target categories: 1) targets. However, the point estimate favored lower BP targets (targets (targets of target. There was a significant increase in serious adverse effects with systolic BP targets of target for the outcome of serious adverse effects. Cluster plots for combined efficacy and safety showed that a systolic BP target of target of <130 mm Hg achieved optimal balance between efficacy and safety. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Sparse Stochastic Optimization Algorithm with Optimal Individual Convergence Rate Based on Random Step-Size%基于随机步长具有最优瞬时收敛速率的稀疏随机优化算法

    Institute of Scientific and Technical Information of China (English)

    周柏; 陶卿; 储德军

    2015-01-01

    几乎所有的稀疏随机算法都来源于在线形式,只能获得平均输出方式的收敛速率,对于强凸优化问题无法达到最优的瞬时收敛速率.文中避开在线形式转到随机模式,直接研究随机优化算法.首先在含有 L1正则化项的稀疏优化问题中加入 L2正则化项,使之具有强凸特性.然后将黑箱优化方法中的随机步长策略引入到当前通用的结构优化算法 COMID 中,得到基于随机步长的混合正则化镜面下降稀疏随机优化算法.最后通过分析 L1正则化问题中软阈值方法的求解特点,证明算法具有最优的瞬时收敛速率.实验表明,文中算法的稀疏性优于 COMID.%Almost all sparse stochastic algorithms are developed from the online setting, and only the convergence rate of average output can be obtained. The optimal rate for strongly convex optimization problems can not be reached as well. The stochastic optimization algorithms are directly studied instead of the online to batch conversation in this paper. Firstly, by incorporating the L2 regularizer into the L1-regularized sparse optimization problems, the strong convexity can be obtained. Then, by introducing the random step-size strategy from the black-box optimization method to the state-of-the-art algorithm-composite objective mirror descent (COMID), a sparse stochastic optimization algorithm based introducing on random step-size hybrid regularized mirror descent ( RS-HMD) is achieved. Finally, based on the analysis of characteristics of soft threshold methods in solving the L1-regularized problem, the optimal individual convergence rate is proved. Experimental results demonstrate that sparsity of RS-HMD is better than that of COMID.

  16. Modeling Integrated Water-User Decisions with Intermittent Supplies

    Science.gov (United States)

    Lund, J. R.; Rosenberg, D.

    2006-12-01

    We present an economic-engineering method to estimate urban water use demands with intermittent water supplies. A two-stage, probabilistic optimization formulation includes a wide variety of water supply enhancement and conservation actions that individual households can adopt to meet multiple water quality uses with uncertain water availability. We embed the optimization in Monte-Carlo simulations to show aggregate effects at a utility (citywide) scale for a population of user conditions and decisions. Parametric analysis provides derivations of supply curves to subsidize conservation, demand responses to alternative pricing, and customer willingness-to-pay to avoid shortages. Results show a good empirical fit for the average and distribution of billed residential water use in Amman, Jordan. Additional outputs give likely market penetration rates for household conservation actions, associated water savings, and subsidies required to entice further adoption. We discuss new insights to size, target, market, and finance conservation programs and interpret a demand curve with block pricing.

  17. BCR Routing for Intermittently Connected Mobile Ad hoc Networks

    Directory of Open Access Journals (Sweden)

    S. RAMESH

    2014-03-01

    Full Text Available The Wireless and the Mobile Networks appear to provide a wide range of applications. Following these, the Mobile Ad hoc Networks (MANET aid in wide development of many applications. The achievement of the real world applications are attained through effective routing. The Intermittently Connected Mobile Ad hoc Network (ICMANET is a sparse network where a full connectivity is never possible. ICMANET is a disconnected MANET and is also a Delay Tolerant Network (DTN that sustains for higher delays. The routing in a disseminated network is a difficult task. A new routing scheme called Bee Colony Routing (BCR is been proposed with a motto of achieving optimal result in delivering the data packet towards the destined node. BCR is proposed with the basis of Bee Colony Optimization technique (BCO. The routing in ICMNAET is done by means of Bee routing protocol. This paper enchants a novel routing methodology for data transmission in ICMANET.

  18. Pancreatitis of biliary origin, optimal timing of cholecystectomy (PONCHO trial: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Bouwense Stefan A

    2012-11-01

    Full Text Available Abstract Background After an initial attack of biliary pancreatitis, cholecystectomy minimizes the risk of recurrent biliary pancreatitis and other gallstone-related complications. Guidelines advocate performing cholecystectomy within 2 to 4 weeks after discharge for mild biliary pancreatitis. During this waiting period, the patient is at risk of recurrent biliary events. In current clinical practice, surgeons usually postpone cholecystectomy for 6 weeks due to a perceived risk of a more difficult dissection in the early days following pancreatitis and for logistical reasons. We hypothesize that early laparoscopic cholecystectomy minimizes the risk of recurrent biliary pancreatitis or other complications of gallstone disease in patients with mild biliary pancreatitis without increasing the difficulty of dissection and the surgical complication rate compared with interval laparoscopic cholecystectomy. Methods/Design PONCHO is a randomized controlled, parallel-group, assessor-blinded, superiority multicenter trial. Patients are randomly allocated to undergo early laparoscopic cholecystectomy, within 72 hours after randomization, or interval laparoscopic cholecystectomy, 25 to 30 days after randomization. During a 30-month period, 266 patients will be enrolled from 18 hospitals of the Dutch Pancreatitis Study Group. The primary endpoint is a composite endpoint of mortality and acute re-admissions for biliary events (that is, recurrent biliary pancreatitis, acute cholecystitis, symptomatic/obstructive choledocholithiasis requiring endoscopic retrograde cholangiopancreaticography including cholangitis (with/without endoscopic sphincterotomy, and uncomplicated biliary colics occurring within 6 months following randomization. Secondary endpoints include the individual endpoints of the composite endpoint, surgical and other complications, technical difficulty of cholecystectomy and costs. Discussion The PONCHO trial is designed to show that early

  19. Impact of syllable stress and phonetic vowel context on the distribution of intermittent aphonia

    DEFF Research Database (Denmark)

    Iwarsson, Jenny; Fredsø, Julie

    2014-01-01

    The occurrence of intermittent aphonia, perceived as sudden interruptions of voicing in connected speech, often reflects high stiffness of the vocal fold mucosa as part of a voice disorder. This retrospective study aimed to investigate the overarching hypothesis that the aphonic instances in voices...... with intermittent aphonia are not totally randomly appearing, but related to syllable stress and phonetic context. Recordings of 31 dysphonic patients with intermittent aphonia reading a standard text were analyzed perceptually. All vowels of the text were labelled and categorized with regard to syllable stress...... in unstressed syllables as opposed to stressed, in vowels following an unvoiced phoneme as opposed to a voiced, and in vowels following two or more unvoiced phonemes as opposed to one unvoiced phoneme. No significant difference was found between vowels following aspirated stops [p], [t], [k] as opposed...

  20. Dietary nitrate supplementation improves team sport-specific intense intermittent exercise performance.

    Science.gov (United States)

    Wylie, Lee J; Mohr, Magni; Krustrup, Peter; Jackman, Sarah R; Ermιdis, Georgios; Kelly, James; Black, Matthew I; Bailey, Stephen J; Vanhatalo, Anni; Jones, Andrew M

    2013-07-01

    Recent studies have suggested that dietary inorganic nitrate (NO₃(-)) supplementation may improve muscle efficiency and endurance exercise tolerance but possible effects during team sport-specific intense intermittent exercise have not been examined. We hypothesized that NO₃(-) supplementation would enhance high-intensity intermittent exercise performance. Fourteen male recreational team-sport players were assigned in a double-blind, randomized, crossover design to consume 490 mL of concentrated, nitrate-rich beetroot juice (BR) and nitrate-depleted placebo juice (PL) over ~30 h preceding the completion of a Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1). Resting plasma nitrite concentration ([NO₂(-)]) was ~400% greater in BR compared to PL. Plasma [NO₂(-)] declined by 20% in PL (P exercise to end-exercise. Performance in the Yo-Yo IR1 was 4.2% greater (P exercise and may be a useful ergogenic aid for team sports players.

  1. Preservation of micronutrients during rapeseed oil refining: a tool to optimize the health value of edible vegetable oils? Rationale and design of the Optim'Oils randomized clinical trial.

    Science.gov (United States)

    Gladine, C; Meunier, N; Blot, Adeline; Bruchet, Lucile; Pagès, X; Gaud, M; Floter, E; Metin, Z; Rossignol, A; Cano, N; Chardigny, J M

    2011-03-01

    Numerous micronutrients naturally abundant in oilseeds prevent the risk of cardiovascular diseases by reducing cholesterolemia and oxidative stress. These micronutrients include phytosterols and various antioxidants such as polyphenols, tocopherols and coenzyme Q10/Q9 but most of them are lost during the oilseed oil refining. The main objective of the Optim'Oil project was to modify the processes of oil refining in order to reduce the lost of micronutrients. Two clinical trials (cross-over, monocentric, randomized, double-blind and controlled) were designed to investigate the effect of an optimized rapeseed oil 1) on cardiovascular biomarkers (long-term study) and 2) on oxidative stress parameters (post-prandial study). For the long-term study, 59 volunteers ingested daily 20 g of oil and 22 g of margarine (optimized or standard) for 2 periods of 3 weeks separated by a 3-week wash-out period. Blood samples were collected at the beginning and at the end of each period. For the post-prandial study, a sub-group of 16 volunteers came fasted at the laboratory and took 300 mL of a test meal containing 60% of the optimized or standard oils. Blood samples were collected before and during 6h after the test meal intake. In comparison with the standard oil and margarine, the optimized oil and margarine exhibit as expected an increased content of phytosterol (+22%), polyphenols (× 11), tocopherols (+131%) and coenzyme Q10/Q9 (+165%). Overall, conditions of this study were relevant to investigate the effect of the optimized rapeseed oil and margarine on the cardiovascular risk and the oxidative stress.

  2. Intermittent changing axis deviation with intermittent left anterior hemiblock during atrial flutter with subclinical hyperthyroidism.

    Science.gov (United States)

    Patanè, Salvatore; Marte, Filippo

    2009-06-26

    Subclinical hyperthyroidism is an increasingly recognized entity that is defined as a normal serum free thyroxine and free triiodothyronine levels with a thyroid-stimulating hormone level suppressed below the normal range and usually undetectable. It has been reported that subclinical hyperthyroidism is not associated with CHD or mortality from cardiovascular causes but it is usually associated with a higher heart rate and a higher risk of supraventricular arrhythmias including atrial fibrillation and atrial flutter. Intermittent changing axis deviation during atrial fibrillation has also rarely been reported. We present a case of intermittent changing axis deviation with intermittent left anterior hemiblock in a 59-year-old Italian man with atrial flutter and subclinical hyperthyroidism. To our knowledge, this is the first report of intermittent changing axis deviation with intermittent left anterior hemiblock in a patient with atrial flutter.

  3. Convergence of quasi-optimal sparse-grid approximation of Hilbert-space-valued functions: application to random elliptic PDEs

    KAUST Repository

    Nobile, F.

    2015-10-30

    In this work we provide a convergence analysis for the quasi-optimal version of the sparse-grids stochastic collocation method we presented in a previous work: “On the optimal polynomial approximation of stochastic PDEs by Galerkin and collocation methods” (Beck et al., Math Models Methods Appl Sci 22(09), 2012). The construction of a sparse grid is recast into a knapsack problem: a profit is assigned to each hierarchical surplus and only the most profitable ones are added to the sparse grid. The convergence rate of the sparse grid approximation error with respect to the number of points in the grid is then shown to depend on weighted summability properties of the sequence of profits. This is a very general argument that can be applied to sparse grids built with any uni-variate family of points, both nested and non-nested. As an example, we apply such quasi-optimal sparse grids to the solution of a particular elliptic PDE with stochastic diffusion coefficients, namely the “inclusions problem”: we detail the convergence estimates obtained in this case using polynomial interpolation on either nested (Clenshaw–Curtis) or non-nested (Gauss–Legendre) abscissas, verify their sharpness numerically, and compare the performance of the resulting quasi-optimal grids with a few alternative sparse-grid construction schemes recently proposed in the literature.

  4. Optimal step-down approach for pediatric asthma controlled by salmeterol/fluticasone: A randomized, controlled trial (OSCAR study

    Directory of Open Access Journals (Sweden)

    Kenichi Akashi

    2016-07-01

    Conclusions: A high level of asthma control was maintained with both approaches. The use of SFC step-down resulted in somewhat better respiratory function, with no worsening of airway inflammation. However, halving the dose of SFC and switching to FP alone are both optimal step-down approaches.

  5. Optimizing prophylactic antibiotic regimen in patients admitted for transrectal ultrasound-guided prostate biopsies: A prospective randomized study

    Directory of Open Access Journals (Sweden)

    Ahmed Fahmy

    2016-09-01

    Conclusion: Determining the prevalence of fluoroquinolone resistance in rectal flora has important implications in the selection of targeted prophylactic antibiotic regimens. Antimicrobial profiles guided by rectal swabs may prove useful to optimize prophylaxis prior to TRUSBx; this strategy is effective at reducing the rates of infectious complications, including sepsis, especially in men at higher risk of infectious complications.

  6. Intermittent ephemeral river-breaching

    Science.gov (United States)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  7. Indwelling versus Intermittent Urinary Catheterization following Total Joint Arthroplasty: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    Full Text Available The purpose of this study is to compare the rates of urinary tract infection (UTI and postoperative urinary retention (POUR in patients undergoing lower limb arthroplasty after either indwelling urinary catheterization or intermittent urinary catheterization.We conducted a meta-analysis of relevant randomized controlled trials (RCT to compare the rates of UTI and POUR in patients undergoing total joint arthroplasty after either indwelling urinary catheterization or intermittent urinary catheterization. A comprehensive search was carried out to identify RCTs. Study-specific risk ratios (RR with 95% confidence intervals (CI were pooled. Additionally, a meta-regression analysis, as well as a sensitivity analysis, was performed to evaluate the heterogeneity.Nine RCTs with 1771 patients were included in this meta-analysis. The results showed that there was no significant difference in the rate of UTIs between indwelling catheterization and intermittent catheterization groups (P>0.05. Moreover, indwelling catheterization reduced the risk of POUR, versus intermittent catheterization, in total joint surgery (P<0.01.Based on the results of the meta-analysis, indwelling urinary catheterization, removed 24-48 h postoperatively, was superior to intermittent catheterization in preventing POUR. Furthermore, indwelling urinary catheterization with removal 24 to 48 hours postoperatively did not increase the risk of UTI. In patients with multiple risk factors for POUR undergoing total joint arthroplasty of lower limb, the preferred option should be indwelling urinary catheterization removed 24-48 h postoperatively.Level I.

  8. Influence of carbohydrate supplementation on plasma cytokine and neutrophil degranulation responses to high intensity intermittent exercise.

    Science.gov (United States)

    Bishop, Nicolette C; Gleeson, Michael; Nicholas, Ceri W; Ali, Ajmol

    2002-06-01

    Ingesting carbohydrate (CHO) beverages during prolonged, continuous heavy exercise results in smaller changes in the plasma concentrations of several cytokines and attenuates a decline in neutrophil function. In contrast, ingesting CHO during prolonged intermittent exercise appears to have negligible influence on these responses, probably due to the overall moderate intensity of these intermittent exercise protocols. Therefore, we examine the effect of CHO ingestion on plasma interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and lipopolysaccharide (LPS)-stimulated neutrophil degranulation responses to high-intensity intermittent running. Six trained male soccer players performed 2 exercise trials, 7 days apart, in a randomized, counterbalanced design. On each occasion, they completed six 15-min periods of intermittent running consisting of maximal sprinting interspersed with less intense periods of running and walking. Subjects consumed either CHO or artificially sweetened placebo (PLA) beverages immediately before and at 15-min intervals during the exercise. At 30 min post-exercise, CHO versus PLA was associated with a higher plasma glucose concentration (p exercise, LPS-stimulated elastase release per neutrophil fell 31% below baseline values on the PLA trial (p = .06) compared with 17% on the CHO trial (p = .30). Plasma TNF-alpha concentration increased following the exercise (main effect of time, p attenuates changes in plasma IL-6 concentration, neutrophil trafficking, and LPS-stimulated neutrophil degranulation in response to intermittent exercise that involves bouts of very high intensity exercise.

  9. Outdoor validation of the 30 minutes intermittent tracking of 100 x CPV

    Science.gov (United States)

    Araki, Kenji; Ota, Yasuyuki; Lee, Kan-Hua; Nishioka, Kensuke; Yamaguchi, Masafumi

    2017-09-01

    HCPV uses trackers, but their cost and reliability have raised problems. These problems may be solved by substantially increasing acceptance angle and mechanical tolerance. For a demonstration of the possibility of such substantial improvement, a 30 minutes intermittent tracking in high concentration applications was examined. To allow for 30 minutes intermittent tracking, both advanced optics and an advanced tracking control were investigated. For advanced optics, a 100 x refractive and dielectric concentrator was designed. It had about plus or minus 5° of acceptance angle. For advanced tracking control, a feed-forward control with a linear error correction was investigated. With combining both optimizations, it was shown that 30 minutes intermittent tracking was validated in outdoor experiments even for an as high as 100 x concentration.

  10. Intermittency in 2D soap film turbulence

    CERN Document Server

    Cerbus, R T

    2013-01-01

    The Reynolds number dependency of intermittency for 2D turbulence is studied in a flowing soap film. The Reynolds number used here is the Taylor microscale Reynolds number R_{\\lambda}, which ranges from 20 to 800. Strong intermittency is found for both the inverse energy and direct enstrophy cascades as measured by (a) the pdf of velocity differences P(\\delta u(r)) at inertial scales r, (b) the kurtosis of P(\\partial_x u), and (c) the scaling of the so-called intermittency exponent \\mu, which is zero if intermittency is absent. Measures (b) and (c) are quantitative, while (a) is qualitative. These measurements are in disagreement with some previous results but not all. The velocity derivatives are nongaussian at all R_{\\lambda} but show signs of becoming gaussian as R_{\\lambda} increases beyond the largest values that could be reached. The kurtosis of P(\\delta u(r)) at various r indicates that the intermittency is scale dependent. The structure function scaling exponents also deviate strongly from the Kraichn...

  11. Two complementary descriptions of intermittency

    CERN Document Server

    Balkovsky, E

    1998-01-01

    We describe two complementary formalisms designed for the description of probability density function (PDF) of the gradients of turbulent fields. The first approach, we call it adiabatic, describes PDF at the values much less than dispersion. The second, instanton, approach gives the tails of PDF at the values of the gradient much larger than dispersion. Together, both approaches give satisfactory description of gradient PDFs, as illustrated here by an example of a passive scalar advected by a one-dimensional compressible random flow.

  12. On intermittent flow characteristics of gas–liquid two-phase flow

    Energy Technology Data Exchange (ETDEWEB)

    Thaker, Jignesh; Banerjee, Jyotirmay, E-mail: jbaner@gmail.com

    2016-12-15

    Highlights: • Unified correlations for intermittent flow characteristics are developed. • Influence of inflow conditions on intermittent flow characteristics is analysed. • Developed correlations can be used for effective design of piping components. - Abstract: Flow visualisation experiments are reported for intermittent regime of gas–liquid two-phase flow. Intermittent flow characteristics, which include plug/slug frequency, liquid plug/slug velocity, liquid plug/slug length, and plug/slug bubble length are determined by image processing of flow patterns captured at a rate of 1600 frames per second (FPS). Flow characteristics are established as a function of inlet superficial velocity of both the phases (in terms of Re{sub SL} and Re{sub SG}). The experimental results are first validated with the existing correlations for slug flow available in literature. It is observed that the correlations proposed in literature for slug flow do not accurately predict the flow characteristics in the plug flow regime. The differences are clearly highlighted in this paper. Based on the measured database for both plug and slug flow regime, modified correlations for the intermittent flow regime are proposed. The correlations reported in the present paper, which also include plug flow characteristics will aid immensely to the effective design and optimization of operating conditions for safer operation of two-phase flow piping systems.

  13. Study of the Fatigue Life and Weight Optimization of an Automobile Aluminium Alloy Part under Random Road Excitation

    Directory of Open Access Journals (Sweden)

    A. Saoudi

    2010-01-01

    Full Text Available Weight optimization of aluminium alloy automobile parts reduces their weight while maintaining their natural frequency away from the frequency range of the power spectral density (PSD that describes the roadway profile. We present our algorithm developed to optimize the weight of an aluminium alloy sample relative to its fatigue life. This new method reduces calculation time; It takes into account the multipoint excitation signal shifted in time, giving a tangle of the constraint signals of the material mesh elements; It also reduces programming costs. We model an aluminium alloy lower vehicle suspension arm under real conditions. The natural frequencies of the part are inversely proportional to the mass and proportional to flexural stiffness, and assumed to be invariable during the process of optimization. The objective function developed in this study is linked directly to the notion of fatigue. The method identifies elements that have less than 10% of the fatigue life of the part's critical element. We achieved a weight loss of 5 to 11% by removing the identified elements following the first iteration.

  14. Intermittent rainfall in dynamic multimedia fate modeling.

    Science.gov (United States)

    Hertwich, E G

    2001-03-01

    It has been shown that steady-state multimedia models (level III fugacity models) lead to a substantial underestimate of air concentrations for chemicals with a low Henry's law constant (H multimedia models are used to estimate the spatial range or inhalation exposure. A dynamic model of pollutant fate is developed for conditions of intermittent rainfall to calculate the time profile of pollutant concentrations in different environmental compartments. The model utilizes a new, mathematically efficient approach to dynamic multimedia fate modeling that is based on the convolution of solutions to the initial conditions problem. For the first time, this approach is applied to intermittent conditions. The investigation indicates that the time-averaged pollutant concentrations under intermittent rainfall can be approximated by the appropriately weighted average of steady-state concentrations under conditions with and without rainfall.

  15. The Yo-Yo intermittent recovery test

    DEFF Research Database (Denmark)

    Bangsbo, Jens; Iaia, F. Marcello; Krustrup, Peter

    2008-01-01

    The two Yo-Yo intermittent recovery (IR) tests evaluate an individual's ability to repeatedly perform intense exercise. The Yo-Yo IR level 1 (Yo-Yo IR1) test focuses on the capacity to carry out intermittent exercise leading to a maximal activation of the aerobic system, whereas Yo-Yo IR level 2...... (Yo-Yo IR2) determines an individual's ability to recover from repeated exercise with a high contribution from the anaerobic system. Evaluations of elite athletes in various sports involving intermittent exercise showed that the higher the level of competition the better an athlete performs in the Yo-Yo...... IR tests. Performance in the Yo-Yo IR tests for young athletes increases with rising age. The Yo-Yo IR tests have shown to be a more sensitive measure of changes in performance than maximum oxygen uptake. The Yo-Yo IR tests provide a simple and valid way to obtain important information...

  16. Magnetic field generation by intermittent convection

    CERN Document Server

    Chertovskih, R; Chimanski, E V

    2016-01-01

    Magnetic field generation by convective flows in transition to weak turbulence is studied numerically. By fixing the Prandtl number at P=0.3 and varying the Rayleigh number (Ra) as a control parameter in three-dimensional Rayleigh-Benard convection of an electrically conducting fluid, a recently reported route to hyperchaos involving quasiperiodic regimes, crises and chaotic intermittent attractors is followed, and the critical magnetic Prandtl number ($P_m^c$) for dynamo action is determined as a function of Ra. A mechanism for the onset of on-off intermittency in the magnetic energy is described, the most beneficial convective regimes for dynamo action are identified, and how intermittency affects the dependence of $P_m^c$ on Ra is discussed.

  17. Chaos synchronization based on intermittent state observer

    Institute of Scientific and Technical Information of China (English)

    Li Guo-Hui; Zhou Shi-Ping; Xu De-Ming

    2004-01-01

    This paper describes the method of synchronizing slave to the master trajectory using an intermittent state observer by constructing a synchronizer which drives the response system globally tracing the driving system asymptotically. It has been shown from the theory of synchronization error-analysis that a satisfactory result of chaos synchronization is expected under an appropriate intermittent period and state observer. Compared with continuous control method,the proposed intermittent method can target the desired orbit more efficiently. The application of the method is demonstrated on the hyperchaotic Rossler systems. Numerical simulations show that the length of the synchronization interval rs is of crucial importance for our scheme, and the method is robust with respect to parameter mismatch.

  18. Forces and energetics of intermittent swimming

    Science.gov (United States)

    Floryan, Daniel; Van Buren, Tyler; Smits, Alexander J.

    2017-08-01

    Experiments are reported on intermittent swimming motions. Water tunnel experiments on a nominally two-dimensional pitching foil show that the mean thrust and power scale linearly with the duty cycle, from a value of 0.2 all the way up to continuous motions, indicating that individual bursts of activity in intermittent motions are independent of each other. This conclusion is corroborated by particle image velocimetry (PIV) flow visualizations, which show that the main vortical structures in the wake do not change with duty cycle. The experimental data also demonstrate that intermittent motions are generally energetically advantageous over continuous motions. When metabolic energy losses are taken into account, this conclusion is maintained for metabolic power fractions less than 1.

  19. Intermittency in Switching Power Converters: Theoretical Analysis

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yu-fei; CHEN Jun-ning; TSE Chi K.; QIU Shui-sheng; KE Dao-ming; SHI Long-xing; SUN Wei-feng

    2006-01-01

    In view of reasonable explanation of intermittent subharmonics and chaos that can be gained from coupling filter between circuits,this paper discusses a method that maps time bifurcation with parameter bifurcation.Based on this mapping method,the general analysis method of characteristic multiplier,which is originally aimed at parameter bifurcation,can be used for the study of intermittency,i.e.,time bifurcation.In this paper,all researches coming from characteristic multipliers,parameter-bifurcation diagrams,and the largest Lyapunov exponent indicate the same results as those produced by simulation and experiment.Thus,it is proved theoretically that the intermittency in switching power converter can be explained in terms of coupling of spurious interference.

  20. Assessing relative volatility/intermittency/energy dissipation

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole E.; Pakkanen, Mikko S.; Schmiegel, Jürgen

    2014-01-01

    We introduce the notion of relative volatility/intermittency and demonstrate how relative volatility statistics can be used to estimate consistently the temporal variation of volatility/intermittency when the data of interest are generated by a non-semimartingale, or a Brownian semistationary...... process in particular. This estimation method is motivated by the assessment of relative energy dissipation in empirical data of turbulence, but it is also applicable in other areas. We develop a probabilistic asymptotic theory for realised relative power variations of Brownian semistationary processes......, and introduce inference methods based on the theory. We also discuss how to extend the asymptotic theory to other classes of processes exhibiting stochastic volatility/intermittency. As an empirical application, we study relative energy dissipation in data of atmospheric turbulence....

  1. Synchronization of Intermittently Coupled Dynamical Networks

    Directory of Open Access Journals (Sweden)

    Gang Zhang

    2013-01-01

    Full Text Available This paper investigates the synchronization phenomenon of an intermittently coupled dynamical network in which the coupling among nodes can occur only at discrete instants and the coupling configuration of the network is time varying. A model of intermittently coupled dynamical network consisting of identical nodes is introduced. Based on the stability theory for impulsive differential equations, some synchronization criteria for intermittently coupled dynamical networks are derived. The network synchronizability is shown to be related to the second largest and the smallest eigenvalues of the coupling matrix, the coupling strength, and the impulsive intervals. Using the chaotic Chua system and Lorenz system as nodes of a dynamical network for simulation, respectively, the theoretical results are verified and illustrated.

  2. Intermittency and Topology of Shock Induced Mixing

    Science.gov (United States)

    Tellez, Jackson; Redondo, Jose M.; Ben Mahjoub, Otman; Malik, Nadeem; Vila, Teresa

    2016-04-01

    The advance of a Rayleigh-Taylor front is described in Linden & Redondo (1991),[1-3] and may be shown to follow a quadratic law in time where the width of the growing region of instability depends on the local mixing efficiency of the different density fluids that accelerate against each other g is the acceleration and A is the Atwood number defined as the diference of densities divided by their sum. This results show the independence of the large amplitude structures on the initial conditions the width of the mixing region depends also on the intermittency of the turbulence. Then dimensional analysis may also depend on the relevant reduced acceleration driven time and the molecular reactive time akin to Damkholer number and the fractal structure of the contact zone [2,4]. Detailed experiments and simulations on RT and RM shock induced fronts analized with respect to structure functions are able to determine which mechanisms are most effective in local mixing which increase the effective fractal dimension, as well as the effect of higher order geometrical parameters, such as the structure functions, in non-homogeneous fluids (Mahjoub et al 1998)[5]. The structure of a Mixing blob shows a relatively sharp head with most of the mixing taking place at the sides due to what seems to be shear instability very similar to the Kelvin-Helmholtz instabilities, but with sideways accelerations. The formation of the blobs and spikes with their secondary instabilities produces a turbulent cascade, evident just after about 1 non-dimensional time unit, from a virtual time origin that takes into account the linear growth phase, as can be seen by the growth of the fractal dimension for different volume fractions. Two-dimensional cuts of the 3D flow also show that vortex flows have closed or spiral streamlines around their core. Examples of such flows can be also seen in the laboratory, for example at the interface of atwo-layer stratified fluid in a tank in which case streamlines

  3. The feasibility of using acoustic markers of speech for optimizing patient outcomes during randomized amplitude variation in deep brain stimulation: a proof of principle methods study

    Directory of Open Access Journals (Sweden)

    Adam P Vogel

    2015-07-01

    Full Text Available Background: Deep brain stimulation (DBS is an effective treatment for reducing symptoms of tremor. A common and typically subjectively determined adverse effect of DBS is dysarthria. Current assessment protocols are driven by the qualitative judgements of treating clinicians and lack the sensitivity and objectivity required to optimize patient outcomes where multiple stimulation parameters are trialled. Objective: To examine the effect of DBS on speech in patients receiving stimulation to the posterior sub-thalamic area (PSA via randomized manipulation of amplitude parameters.Methods: Six patients diagnosed with tremor receiving treatment via DBS of the PSA were assessed within a double-blinded, within-subjects experimental protocol. Amplitude (i.e., voltage or current was randomly adjusted across 10 settings while speech samples (e.g., sustained vowel, counting to 10 were recorded to identify the patient-specific settings required for optimal therapeutic benefit (reduced tremor with minimal adverse effects (altered speech. Speech production between stimulation parameters was quantified using acoustic analysis.Results: Speech changed as a response to DBS but those changes were not uniform across patients nor were they generally in line with changes in amplitude with the exception of reduced vocal control and increased mean silence length in two patients. Speech outcomes did not correlate with changes in tremor.Conclusion(s: Intra-individual changes in speech were detected as a response to modified amplitude however no clear pattern was observed across patients as a group. The use of objective acoustic measures allows for quantification of speech changes during DBS optimization protocols, even when those changes are subtle and potentially difficult to detect perceptually.

  4. Intermittently connected mobile ad hoc networks

    CERN Document Server

    Jamalipour, Abbas

    2011-01-01

    In the last few years, there has been extensive research activity in the emerging area of Intermittently Connected Mobile Ad Hoc Networks (ICMANs). By considering the nature of intermittent connectivity in most real word mobile environments without any restrictions placed on users' behavior, ICMANs are eventually formed without any assumption with regard to the existence of a end-to-end path between two nodes wishing to communicate. It is different from the conventional Mobile Ad Hoc Networks (MANETs), which have been implicitly viewed as a connected graph with established complete paths betwe

  5. Optimal filtering for uncertain systems with stochastic nonlinearities, correlated noises and missing measurements

    Institute of Scientific and Technical Information of China (English)

    Shuo Zhang,Yan Zhao,Min Li,; Jianhui Zhao

    2015-01-01

    The global y optimal recursive filtering problem is stu-died for a class of systems with random parameter matrices, stochastic nonlinearities, correlated noises and missing measure-ments. The stochastic nonlinearities are presented in the system model to reflect multiplicative random disturbances, and the addi-tive noises, process noise and measurement noise, are assumed to be one-step autocorrelated as wel as two-step cross-correlated. A series of random variables is introduced as the missing rates governing the intermittent measurement losses caused by un-favorable network conditions. The aim of the addressed filtering problem is to design an optimal recursive filter for the uncertain systems based on an innovation approach such that the filtering error is global y minimized at each sampling time. A numerical simulation example is provided to il ustrate the effectiveness and applicability of the proposed algorithm.

  6. Intermittent Flow Regimes in a Transonic Fan Airfoil Cascade

    Science.gov (United States)

    Lepicovsky, J.; McFarland, E. R.; Chima, R. V.; Capece, V. R.; Hayden, J.

    2002-01-01

    A study was conducted in the NASA Glenn Research Center linear cascade on the intermittent flow on the suction surface of an airfoil section from the tip region of a modern low aspect ratio fan blade. Experimental results revealed that, at a large incidence angle, a range of transonic inlet Mach numbers exist where the leading-edge shock-wave pattern was unstable. Flush mounted high frequency response pressure transducers indicated large local jumps in the pressure in the leading edge area, which generates large intermittent loading on the blade leading edge. These measurements suggest that for an inlet Mach number between 0.9 and 1.0 the flow is bi-stable, randomly switching between subsonic and supersonic flows. Hence, it appears that the change in overall flow conditions in the transonic region is based on the frequency of switching between two stable flow states rather than on the continuous increase of the flow velocity. To date, this flow behavior has only been observed in a linear transonic cascade. Further research is necessary to confirm this phenomenon occurs in actual transonic fans and is not the byproduct of an endwall restricted linear cascade.

  7. The optimal strategy of percutaneous coronary intervention for ST-elevation myocardial infarction patients with multivessel disease: an updated meta-analysis of 9 randomized controlled trials.

    Science.gov (United States)

    Fan, Zhong G; Gao, Xiao F; Li, Xiao B; Mao, Wen X; Chen, Li W; Tian, Nai L

    2017-04-01

    The optimal strategy of percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI) and multivessel disease (MVD) still remains controversial. This study sought to explore the optimal PCI strategy for those patients. Medline, EMBASE and the Cochrane Controlled Trials Registry were searched for relevant studies. We analyzed the comparison of major adverse cardiac events (MACEs) as the primary end point between the preventive PCI strategy and the culprit only PCI strategy (CV-PCI). The further analysis of two subgroups described as the complete multivessel PCI strategy during primary procedure (CMV-PCI) and the staged PCI strategy (S-PCI) was also performed. Nine randomized trials were identified. The risk of MACEs was reduced significantly regarding to preventive PCI strategy (OR=0.41, 95% CI: 0.31-0.53, Pstrategy. There were lower risks of long-term mortality, reinfarction and repeat revascularization in the preventive PCI group compared to the CV-PCI group (OR=0.41, 95% CI: 0.27-0.62, Pstrategy reduced the incidence of long-term mortality versus CMV-PCI strategy. The preventive PCI is associated with the lower risk of MACEs in STEMI patients with MVD compared to the CV-PCI strategy, and the S-PCI strategy seems to be an optimal choice for these patients rather than the CMV-PCI.

  8. Optimally Stopped Optimization

    Science.gov (United States)

    Vinci, Walter; Lidar, Daniel A.

    2016-11-01

    We combine the fields of heuristic optimization and optimal stopping. We propose a strategy for benchmarking randomized optimization algorithms that minimizes the expected total cost for obtaining a good solution with an optimal number of calls to the solver. To do so, rather than letting the objective function alone define a cost to be minimized, we introduce a further cost-per-call of the algorithm. We show that this problem can be formulated using optimal stopping theory. The expected cost is a flexible figure of merit for benchmarking probabilistic solvers that can be computed when the optimal solution is not known and that avoids the biases and arbitrariness that affect other measures. The optimal stopping formulation of benchmarking directly leads to a real-time optimal-utilization strategy for probabilistic optimizers with practical impact. We apply our formulation to benchmark simulated annealing on a class of maximum-2-satisfiability (MAX2SAT) problems. We also compare the performance of a D-Wave 2X quantum annealer to the Hamze-Freitas-Selby (HFS) solver, a specialized classical heuristic algorithm designed for low-tree-width graphs. On a set of frustrated-loop instances with planted solutions defined on up to N =1098 variables, the D-Wave device is 2 orders of magnitude faster than the HFS solver, and, modulo known caveats related to suboptimal annealing times, exhibits identical scaling with problem size.

  9. Optimizing Household Chlorination Marketing Strategies: A Randomized Controlled Trial on the Effect of Price and Promotion on Adoption in Haiti.

    Science.gov (United States)

    Ritter, Michael; Camille, Eveline; Velcine, Christophe; Guillaume, Rose-Kerline; Lantagne, Daniele

    2017-07-01

    Household water treatment can reduce diarrheal morbidity and mortality in developing countries, but adoption remains low and supply is often unreliable. To test effects of marketing strategies on consumers and suppliers, we randomized 1,798 households in rural Haiti and collected data on purchases of a household chlorination product for 4 months. Households received randomly selected prices ($0.11-$0.56 per chlorine bottle), and half received monthly visits from sales agents. Each $0.22 drop in price increased purchases by 0.10 bottles per household per month (P sales agents increased purchases at mid-range prices; however, the additional revenue did not offset visit cost. Choosing the lowest price and conducting visits maximizes chlorine purchase, whereas slightly raising the retail price and not conducting visits maximizes cost recovery. For the equivalent cost, price discounts increase purchases 4.2 times as much as adding visits at the current retail price. In this context, price subsidies may be a more cost-effective use of resources than household visits, though all marketing strategies tested offer cost-effective ways to achieve incremental health impact. Decisions about pricing and promotion for health products in developing countries affect health impact, cost recovery, and cost-effectiveness, and tradeoffs between these goals should be made explicit in program design.

  10. Optimizing exposure-based CBT for anxiety disorders via enhanced extinction: Design and methods of a multicentre randomized clinical trial.

    Science.gov (United States)

    Heinig, Ingmar; Pittig, Andre; Richter, Jan; Hummel, Katrin; Alt, Isabel; Dickhöver, Kristina; Gamer, Jennifer; Hollandt, Maike; Koelkebeck, Katja; Maenz, Anne; Tennie, Sophia; Totzeck, Christina; Yang, Yunbo; Arolt, Volker; Deckert, Jürgen; Domschke, Katharina; Fydrich, Thomas; Hamm, Alfons; Hoyer, Jürgen; Kircher, Tilo; Lueken, Ulrike; Margraf, Jürgen; Neudeck, Peter; Pauli, Paul; Rief, Winfried; Schneider, Silvia; Straube, Benjamin; Ströhle, Andreas; Wittchen, Hans-Ulrich

    2017-06-01

    Exposure-based psychological interventions currently represent the empirically best established first line form of cognitive-behavioural therapy for all types of anxiety disorders. Although shown to be highly effective in both randomized clinical and other studies, there are important deficits: (1) the core mechanisms of action are still under debate, (2) it is not known whether such treatments work equally well in all forms of anxiety disorders, including comorbid diagnoses like depression, (3) it is not known whether an intensified treatment with more frequent sessions in a shorter period of time provides better outcome than distributed sessions over longer time intervals. This paper reports the methods and design of a large-scale multicentre randomized clinical trial (RCT) involving up to 700 patients designed to answer these questions. Based on substantial advances in basic research we regard extinction as the putative core candidate model to explain the mechanism of action of exposure-based treatments. The RCT is flanked by four add-on projects that apply experimental neurophysiological and psychophysiological, (epi)genetic and ecological momentary assessment methods to examine extinction and its potential moderators. Beyond the focus on extinction we also involve stakeholders and routine psychotherapists in preparation for more effective dissemination into clinical practice. Copyright © 2017 John Wiley & Sons, Ltd.

  11. Biological Nutrient Removal in an Intermittently Aerated Bioreactor

    Directory of Open Access Journals (Sweden)

    J. Derco

    2017-07-01

    Full Text Available The extension of biological processes from carbonaceous impurities removal to nitrogen and phosphorus removal had an impact on the biological system configuration. The system must be well designed, optimized, and operated at its optimum in order to meet the ever more stringent effluent standards. An intermittently aerated completely mixed lab-scale activated sludge bioreactor (IACMB has been used for modelling biological processes of nutrients removal. Concerning the nitrogen removal, the operating cycles 15–30 (15 minutes of aeration, 30 minutes of only mixing without aeration and 30–30 were tested. For the experiments with luxury uptake processes, the operating cycles 15–45, 15–90, 30–60 and 15–75 were used. The cycle 15–75 was the most satisfactory with convenient lengths of aerobic, anoxic, and anaerobic period, high efficiency of the nitrification and denitrification processes, and significant decrease in phosphorus concentration. The results have shown that the intermittently aerated bioreactors are suitable for nitrogen removal as well as luxury uptake of phosphorus. The main advantage is high flexibility in maintenance and control of biochemical environments in the bioreactor.

  12. Intermittent oral iron supplementation during pregnancy.

    Science.gov (United States)

    Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Gomez Malave, Heber; Flores-Urrutia, Monica C; Dowswell, Therese

    2015-10-19

    Anaemia is a frequent condition during pregnancy, particularly among women in low- and middle-income countries. Traditionally, gestational anaemia has been prevented with daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. two or three times a week on non-consecutive days) supplementation has been proposed as an alternative to daily supplementation. To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 July 2015), the WHO International Clinical Trials Registry Platform (ICTRP) (31 July 2015) and contacted relevant organisations for the identification of ongoing and unpublished studies (31 July 2015). Randomised or quasi-randomised trials. We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. This review includes 27 trials from 15 countries, but only 21 trials (with 5490 women) contributed data to the review. All studies compared daily versus intermittent iron supplementation. The methodological quality of included studies was mixed and most had high levels of attrition.The overall assessment of the quality of the evidence for primary infant outcomes was low and for maternal outcomes very low.Of the 21 trials contributing data, three studies provided intermittent iron alone, 14 intermittent iron + folic acid and four intermittent iron plus multiple vitamins and minerals in comparison with the same composition of supplements provided in a daily regimen.Overall, for women receiving any intermittent

  13. Influence of work-interval intensity and duration on time spent at a high percentage of VO2max during intermittent supramaximal exercise.

    Science.gov (United States)

    Wakefield, Benjamin R; Glaister, Mark

    2009-12-01

    The purpose of this study was to examine the effect of work-interval duration (WID) and intensity on the time spent at, or above, 95% VO2max (T95 VO2max) during intermittent bouts of supramaximal exercise. Over a 5-week period, 7 physically active men with a mean (+/-SD) age, height, body mass, and VO2max of 22 +/- 5 years, 181.5 +/- 5.6 cm, 86.4 +/- 11.4 kg, and 51.5 +/- 1.5 ml.kg-1.min-1, respectively, attended 7 testing sessions. After completing a submaximal incremental test on a treadmill to identify individual oxygen uptake/running velocity relationships, subjects completed a maximal incremental test to exhaustion to VO2max and subsequently (from the aforementioned relationship) the minimum velocity required to elicit VO2max (vVO2max). In a random order, subjects then carried out 3 intermittent runs to exhaustion at both 105% and 115% vVO2max. Each test used a different WID (20 s, 25 s, or 30 s) interspersed with 20-second passive recovery periods. Results revealed no significant difference in T95 vVO2max for intermittent runs at 105% versus 115% vVO2max (p = 0.142). There was, however, a significant effect (p VO2max, with WIDs of 30 seconds enabling more time relative to WIDs of 20 seconds (p = 0.018) and 25 seconds (p = 0.009). Moreover, there was an interaction between intensity and duration such that the effect of WID was magnified at the lower exercise intensity (p = 0.046). In conclusion, despite a number of limitations, the results of this investigation suggest that exercise intensities of approximately 105% vVO2max combined with WIDs greater than 25 seconds provide the best way of optimizing T95 VO2max when using fixed 20-second stationary rest periods.

  14. Enhanced recovery pathways optimize health outcomes and resource utilization: A meta-analysis of randomized controlled trials in colorectal surgery

    DEFF Research Database (Denmark)

    Adamina, Michel; Kehlet, Henrik; Tomlinson, George A;

    2011-01-01

    Background Health care systems provide care to increasingly complex and elderly patients. Colorectal surgery is a prime example, with high volumes of major procedures, significant morbidity, prolonged hospital stays, and unplanned readmissions. This situation is exacerbated by an exponential rise...... in costs that threatens the stability of health care systems. Enhanced recovery pathways (ERP) have been proposed as a means to reduce morbidity and improve effectiveness of care. We have reviewed the evidence supporting the implementation of ERP in clinical practice. Methods Medline, Embase......, and the Cochrane library were searched for randomized, controlled trials comparing ERP with traditional care in colorectal surgery. Systematic reviews and papers on ERP based on data published in major surgical and anesthesiology journals were critically reviewed by international contributors, experienced...

  15. Virtual fabrication using directed self-assembly for process optimization in a 14-nm dynamic random access memory

    Science.gov (United States)

    Kamon, Mattan; Akbulut, Mustafa; Yan, Yiguang; Faken, Daniel; Pap, Andras; Allampalli, Vasanth; Greiner, Ken; Fried, David

    2016-07-01

    For directed self-assembly (DSA) to be deployed in advanced semiconductor technologies, it must reliably integrate into a full process flow. We present a methodology for using virtual fabrication software, including predictive DSA process models, to develop and analyze the replacement of self-aligned quadruple patterning with Liu-Nealey chemoepitaxy on a 14-nm dynamic random access memory (DRAM) process. To quantify the impact of this module replacement, we investigated a key process yield metric for DRAM, interface area between the capacitor contacts and transistor source/drain. Additionally, we demonstrate virtual fabrication of the DRAM cell's hexagonally packed capacitors patterned with an array of diblock copolymer cylinders in place of fourfold litho-etch (LE4) patterning.

  16. Pharm GKB: Porphyria, Acute Intermittent [PharmGKB

    Lifescience Database Archive (English)

    Full Text Available Overview Alternate Names: PharmGKB Accession Id: PA166048717 External Vocabularies NDFRT: Porphyria, Acute... Intermittent (N0000003536) Common Searches Search Medline Plus Search CTD Pharm GKB: Porphyria, Acute Intermittent ...

  17. Comparison of dexmedetomidine, midazolam, and propofol as an optimal sedative for upper gastrointestinal endoscopy: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Sumanth Samson

    2014-01-01

    Full Text Available Context: Midazolam and propofol are effective sedatives for use in upper gastrointestinal endoscopy (UGIE; however, their utility is limited when used alone. In this regard, dexmedetomidine seems to be a promising sedative. Aims: The aim was to compare the hemodynamic effects and sedation efficacy of these drugs in patients undergoing elective diagnostic UGIE. Settings and Design: Randomized control double-blind study was conducted at a teaching hospital. Subjects and Methods: Patients belonging to ASA Grade I or II, undergoing diagnostic elective UGIE were enrolled in the study and randomized into three groups; Group I received midazolam infusion, Group II received propofol infusion and Group III received dexmedetomidine infusion. Hemodynamic parameters and adverse events were recorded during the procedure (intra-operative period [IOP]. Both patient and endoscopist satisfaction were rated on visual analog scale (0 = no pain/least difficulty to 10 = worst pain/maximum difficulty. Recovery was recorded as time to achieve modified Aldrete score of 10/10. Statistical Analysis: Parametric test analysis of variance was applied to compare the means of three groups of continuous data. Results: Ninety patients were analyzed. Mean arterial pressure was significantly lower in the propofol group at IOP 2 , IOP 4 , IOP 8 , and IOP 10 compared with dexmedetomidine and midazolam group. The endoscopist satisfaction level was significantly higher in dexmedetomidine group as compared to propofol and midazolam (60%, 56.7%, 13.3%; P < 0.001. Significantly faster recovery was observed in dexmedetomidine group compared to midazolam and propofol group (7.7 ± 3.9, 18.3 ± 3.8, 12.7 ± 2.9 min; P = 0.001. Conclusions: Use of dexmedetomidine was associated with greater hemodynamic stability and faster recovery when compared to propofol and midazolam.

  18. Intermittent demand : Linking forecasting to inventory obsolescence

    NARCIS (Netherlands)

    Teunter, Ruud H.; Syntetos, Aris A.; Babai, M. Zied

    2011-01-01

    The standard method to forecast intermittent demand is that by Croston. This method is available in ERP-type solutions such as SAP and specialised forecasting software packages (e.g. Forecast Pro), and often applied in practice. It uses exponential smoothing to separately update the estimated demand

  19. Intermittent resistive faults in digital cmos circuits

    NARCIS (Netherlands)

    Kerkhoff, Hans G.; Ebrahimi, H.

    2015-01-01

    A major threat in extremely dependable high-end process node integrated systems in e.g. Avionics are no failures found (NFF). One category of NFFs is the intermittent resistive fault, often originating from bad (e.g. Via or TSV-based) interconnections. This paper will show the impact of these faults

  20. Current drive induced by intermittent trapping

    Energy Technology Data Exchange (ETDEWEB)

    Nakach, R. [Association Euratom-CEA, CEA/Cadarache, Dept. de Recherches sur la Fusion Controlee (DRFC), 13 - Saint-Paul-lez-Durance (France); Gell, Y. [CET, Israel (Israel)

    1999-02-01

    We propose a mechanism for driving a current in a dispersive plasma based on intermittent trapping of electrons in a ponderomotive well generated by two- counterpropagating electron cyclotron waves. By choosing properly the parameters of the system, this mechanism is expected to induce a high efficiency current drive. (authors)

  1. Intermittent Swimming with a Flexible Propulsor

    Science.gov (United States)

    Akoz, Emre; Zeyghami, Samane; Moored, Keith

    2016-11-01

    Some animals propel themselves by using an intermittent swimming gait known as a burst-and-glide or a burst-and-coast motion. These swimmers tend to have a more pronounced pitching of their caudal fins than heaving leading to low non-dimensional heave-to-pitch ratios. Recent work has shown that when this ratio is sufficiently low the efficiency of an intermittently heaving/pitching airfoil can be significantly improved over a continuously oscillating airfoil. However, fish that swim with an intermittent gait, such as cod and saithe, do not have rigid fins, but instead have highly flexible fins. To examine the performance and flow structures of an intermittent swimmer with a flexible propulsor, a fast boundary element method solver strongly coupled with a torsional-spring structural model was developed. A self-propelled virtual body combined with a flexible-hinged pitching airfoil is used to model a free-swimming animal and its flexible caudal fin. The duty cycle of the active to the coasting phase of motion, the torsional spring flexibility and the forcing frequency are all varied. The cost-of-transport and the swimming speed are measured and connected to the observed wake patterns. Supported by the Office of Naval Research under Program Director Dr. Bob Brizzolara, MURI Grant Number N00014-14-1-0533.

  2. INTERMITTENCY, A TEST FOR STRING FRAGMENTATION PROCESSES

    NARCIS (Netherlands)

    SCHOLTEN, O

    The Artru-Mennessier and the string fragmentation procedure as implemented in the code VENUS have been compared. The two fragmentation prescriptions predict a similar rapidity spectrum including its energy dependence and event multiplicities, but give rise to very different intermittency results.

  3. Management of patients with intermittent claudication

    NARCIS (Netherlands)

    S. Spronk (Sandra)

    2008-01-01

    textabstractIntermittent claudication is the first and mildest manifestation of peripheral arterial disease, caused by the atherosclerotic process of progressive narrowing of one or more of the arteries of the peripheral circulation.1 If the arterial system fails, it results in a progressive oxygen

  4. Kalman Filtering with Intermittent Observations: Weak Convergence and Moderate Deviations

    CERN Document Server

    Kar, Soummya

    2009-01-01

    The paper considers the problem of Kalman filtering with intermittent observations, where the observation packet arrival process is modeled as a Bernoulli process. We start by extending the results of \\cite{Riccati-weakconv} to show that the sequence of random conditional error covariance matrices converges in distribution to a unique invariant distribution $\\mathbb{\\mu}^{\\bar{\\gamma}}$, as long as the packet arrival probability $\\bar{\\gamma}>0$. We completely characterize the sequence ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ of invariant distributions as $\\bar{\\gamma}\\uparrow 1$, by showing that the sequence ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ satisfies a moderate deviations principle (MDP) with a good rate function $I$, which is explicitly characterized. We then study the sequence of invariant distributions ${\\mathbb{\\mu}^{\\bar{\\gamma}}}$ as $\\bar{\\gamma}\\uparrow 1$. We show that, as $\\bar{\\gamma}\\uparrow 1$, ...

  5. The dialysis catheter and infectious peritonitis in intermittent peritoneal dialysis

    DEFF Research Database (Denmark)

    Kolmos, Hans Jørn; Hemmeløff Andersen, Karl Erik; Hansen, Lise

    1984-01-01

    118 episodes of infectious peritonitis registered among 156 patients treated with intermittent peritoneal dialysis over a 5-yr period were analysed with special reference to potential routes of infection associated with the dialysis catheter. Peritonitis was randomly distributed among the patients......, and the change of keeping free of peritonitis declined exponentially with time. The main factor determining the individual number of episodes was the total space of time, in which a patient had been wearing a dialysis catheter, whereas the number of catheter disconnections played no significant role. A relative...... preponderance of cases due to Enterobacteriaceae was noted within the first week after catheter implantation. In contrast with this, peritonitis with skin microorganisms was not associated with the implantation of catheters....

  6. Intermittent inhaled corticosteroids in infants with episodic wheezing

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Hermansen, Mette Northman; Loland, Lotte

    2006-01-01

    secondary outcomes were the time to discontinuation due to persistent wheezing and safety, as evaluated by height and bone mineral density at the end of the study. RESULTS: We enrolled 411 infants and randomly assigned 294 to receive budesonide at a first episode of wheezing. The proportion of symptom...... not affected by treatment. CONCLUSIONS: Intermittent inhaled corticosteroid therapy had no effect on the progression from episodic to persistent wheezing and no short-term benefit during episodes of wheezing in the first three years of life. (ClinicalTrials.gov number, NCT00234390.).......BACKGROUND: We hypothesized that asthma is preceded by a stage of recurrent episodes of wheezing during the first years of life and that inhaled corticosteroid therapy during symptomatic episodes in this early phase may delay progression to persistent wheezing. METHODS: We assigned one...

  7. Suppression of spiral waves using intermittent local electric shock

    Institute of Scientific and Technical Information of China (English)

    Ma Jun; Ying He-Ping; Li Yan-Long

    2007-01-01

    In this paper, an intermittent local electric shock scheme is proposed to suppress stable spiral waves in the Barkley model by a weak electric shock (about 0.4 to 0.7) imposed on a random selected n × n grids (n = 1-5, compared with the original 256×256 lattice) and monitored synchronically the evolutions of the activator on the grids as the sampled signal of the activator steps out a given threshold (i.e., the electric shock works on the n × n grids if the activator u (≤) 0.4 or u (≥) 0.8). The numerical simulations show that a breakup of spiral is observed in the media state evolution to finally obtain homogeneous states if the electric shock with appropriate intensity is imposed.

  8. Intermittent Aeration in Biological Treatment of Wastewater

    Directory of Open Access Journals (Sweden)

    H. Doan

    2009-01-01

    Full Text Available Problem statement: E-coating process is widely used to provide a protective coating layer on metal parts in the automotive and metal finishing industry. The wastewater from the coating process contains organic compounds that are used in the cleaning, pretreatment and coating steps. Organic pollutants can be removed biologically. In the aerobic biological treatment, water aeration accounts for a significant portion of the total operating cost of the treatment process. Intermittent aeration is thus of benefit since it would reduce the energy consumption in the wastewater treatment. In the present study, wastewater from an electro-coating process was treated biologically using a packed column as an aerator where the wastewater was aerated by a countercurrent air flow. The objective was to obtain an optimum aeration cycle. Approach: Intermittent aeration time was varied at different preset cycles. An operational optimum of the aeration time (or air-water contacting time in the column was determined from the BOD5 removal after a certain treatment period. For continuous aeration of the wastewater, the air-liquid contacting time in the column was 52 min for 24 h of treatment. A unit energy consumption for pumping liquid and air, which was defined as the energy consumption per percent BOD5 removed, was used as a criterion to determine the optimum contacting time. Results: Optimum air-liquid contacting times were found to be about 38, 26 and 22 min for the treatment times of 24, 48 and 72 h, consecutively. This indicates that 27-58% saving on the unit energy consumption can be achieved using intermittent aeration of the wastewater. On the basis of the overall BOD5 removal, 17% and 23% savings in energy were observed with the intermittent aeration as compared to the continuous aeration of the wastewater for 48 and 72 h. Conclusion: The results obtained indicate that an appropriate intermittent aeration cycle can bring about a substantial energy saving

  9. Water quality effects of intermittent water supply in Arraiján, Panama.

    Science.gov (United States)

    Erickson, John J; Smith, Charlotte D; Goodridge, Amador; Nelson, Kara L

    2017-05-01

    Intermittent drinking water supply is common in low- and middle-income countries throughout the world and can cause water quality to degrade in the distribution system. In this study, we characterized water quality in one study zone with continuous supply and three zones with intermittent supply in the drinking water distribution network in Arraiján, Panama. Low or zero pressures occurred in all zones, and negative pressures occurred in the continuous zone and two of the intermittent zones. Despite hydraulic conditions that created risks for backflow and contaminant intrusion, only four of 423 (0.9%) grab samples collected at random times were positive for total coliform bacteria and only one was positive for E. coli. Only nine of 496 (1.8%) samples had turbidity >1.0 NTU and all samples had ≥0.2 mg/L free chlorine residual. In contrast, water quality was often degraded during the first-flush period (when supply first returned after an outage). Still, routine and first-flush water quality under intermittent supply was much better in Arraiján than that reported in a previous study conducted in India. Better water quality in Arraiján could be due to better water quality leaving the treatment plant, shorter supply outages, higher supply pressures, a more consistent and higher chlorine residual, and fewer contaminant sources near pipes. The results illustrate that intermittent supply and its effects on water quality can vary greatly between and within distribution networks. The study also demonstrated that monitoring techniques designed specifically for intermittent supply, such as continuous pressure monitoring and sampling the first flush, can detect water quality threats and degradation that would not likely be detected with conventional monitoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Biotrickling filtration of isopropanol under intermittent loading conditions.

    Science.gov (United States)

    San-Valero, Pau; Penya-Roja, Josep M; Sempere, Feliu; Gabaldón, Carmen

    2013-07-01

    This paper investigates the removal of isopropanol by gas-phase biotrickling filtration. Two plastic packing materials, one structured and one random, have been evaluated in terms of oxygen mass transfer and isopropanol removal efficiency. Oxygen mass transfer experiments were performed at gas velocities of 104 and 312 m h⁻¹ and liquid velocities between 3 and 33 m h⁻¹. Both materials showed similar mass transfer coefficients up to liquid velocities of 15 m h⁻¹. At greater liquid velocities, the structured packing exhibited greater oxygen mass transfer coefficients. Biotrickling filtration experiments were carried out at inlet loads (IL) from 20 to 65 g C m⁻³ h⁻¹ and empty bed residence times (EBRT) from 14 to 160 s. To simulate typical industrial emissions, intermittent isopropanol loading (16 h/day, 5 day/week) and intermittent spraying frequency (15 min/1.5 h) were applied. Maximum elimination capacity of 51 g C m⁻³ h⁻¹ has been obtained for the random packing (IL of 65 g C m⁻³ h⁻¹, EBRT of 50 s). The decrease in irrigation frequency to 15 min every 3 h caused a decrease in the outlet emissions from 86 to 59 mg C Nm⁻³ (inlet of 500 mg C Nm⁻³). The expansion of spraying to night and weekend periods promoted the degradation of the isopropanol accumulated in the water tank during the day, reaching effluent concentrations as low as 44 mg C Nm⁻³. After a 7-week starvation period, the performance was recovered in less than 10 days, proving the robustness of the process.

  11. 40 CFR 51.119 - Intermittent control systems.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Intermittent control systems. 51.119... Intermittent control systems. (a) The use of an intermittent control system (ICS) may be taken into account in... of any constant pollution control system which was in use before December 31, 1970, or the...

  12. Benign painful shoulder syndrome. Initial results of a single-center prospective randomized radiotherapy dose-optimization trial

    Energy Technology Data Exchange (ETDEWEB)

    Ott, O.J.; Hertel, S.; Gaipl, U.S.; Frey, B.; Schmidt, M.; Fietkau, R. [University Hospital Erlangen (Germany). Department of Radiation Oncology

    2012-12-15

    Background and purpose: To compare the efficacy of two different dose-fractionation schedules for radiotherapy of patients with benign painful shoulder syndrome. Patients and methods: Between February 2006 and February 2010, 312 consecutive evaluable patients were recruited for this prospective randomized trial. All patients received radiotherapy with an orthovoltage technique. One radiotherapy course consisted of 6 single fractions in 3 weeks. In case of insufficient remission of pain after 6 weeks, a second radiation series was performed. Patients were randomly assigned to receive either single doses of 0.5 or 1.0 Gy. The endpoint was pain reduction. Pain was measured before, right after, and 6 weeks after radiotherapy using a visual analogue scale (VAS) and a comprehensive pain score (CPS). Results: The overall response rate for all patients was 83% directly after and 85% 6 weeks after radiotherapy. The mean VAS values before, directly after, and 6 weeks after treatment for the 0.5 and 1.0 Gy groups were 56.8 {+-} 23.7 and 53.2 {+-} 21.8 (p = 0.158), 38.2 {+-} 26.1 and 34.0 {+-} 24.5 (p = 0.189), and 33.0 {+-} 27.2 and 23.7 {+-} 22.7 (p = 0.044), respectively. The mean CPS before, directly after, and 6 weeks after treatment was 9.7 {+-} 3.0 and 9.5 {+-} 2.7 (p = 0.309), 6.1 {+-} 3.6 and 5.4 {+-} 3.6 (p = 0.096), 5.3 {+-} 3.7 and 4.1 {+-} 3.7 (p = 0.052), respectively. Despite a slight advantage in the VAS analysis for the 1.0 Gy group for delayed response, the CPS analysis revealed no statistically significant differences between the two single-dose trial arms for early (p = 0.652) and delayed response quality (p = 0.380). Conclusion: Radiotherapy is an effective treatment option for the management of benign painful shoulder syndrome. Concerning radiation protection, the dose for a radiotherapy series is recommended not to exceed 3-6 Gy. (orig.)

  13. Random-phase approximation correlation energies from Lanczos chains and an optimal basis set: theory and applications to the benzene dimer.

    Science.gov (United States)

    Rocca, Dario

    2014-05-14

    A new ab initio approach is introduced to compute the correlation energy within the adiabatic connection fluctuation dissipation theorem in the random phase approximation. First, an optimally small basis set to represent the response functions is obtained by diagonalizing an approximate dielectric matrix containing the kinetic energy contribution only. Then, the Lanczos algorithm is used to compute the full dynamical dielectric matrix and the correlation energy. The convergence issues with respect to the number of empty states or the dimension of the basis set are avoided and the dynamical effects are easily kept into account. To demonstrate the accuracy and efficiency of this approach the binding curves for three different configurations of the benzene dimer are computed: T-shaped, sandwich, and slipped parallel.

  14. The Parameters Optimizing Design of Double Suspension Arm Torsion Bar in the Electric Sight-Seeing Car by Random Vibration Analyzing Method

    Directory of Open Access Journals (Sweden)

    Shui-Ting Zhou

    2017-01-01

    Full Text Available This study is about the impact of the performance and the sensitivity analysis for parameters of the torsion bar suspension in the electric sight-seeing car, which the authors’ laboratory designed and which is used in the authors’ university. The suspension stiffness was calculated by using the virtual work principle, the vector algebra, and tensor of finite rotation methods and was verified by the ADAMS software. Based on the random vibration analysis method, the paper analyzed the dynamic tire load (DTL, suspension working space (SWS, and comfort performance parameters. For the purpose of decreasing the displacement of the suspension and limiting the frequency of impacting the stop block, the paper examined the three parameters and optimized the basic parameters of the torsion bar. The results show that the method achieves a great effect and contributes an accurate value for the general layout design.

  15. Distributed Particle Filter Implementation with Intermittent/Irregular Consensus Convergence

    CERN Document Server

    Mohammadi, Arash

    2011-01-01

    Motivated by non-linear, non-Gaussian, distributed multi-sensor/agent navigation and tracking applications, we propose a multi-rate consensus/fusion based framework for distributed implementation of the particle filter (CF/DPF). The CF/DPF framework is based on running localized particle filters to estimate the overall state vector at each observation node. Separate fusion filters are designed to consistently assimilate the local filtering distributions into the global posterior by compensating for the common past information between neighbouring nodes. The CF/DPF offers two distinct advantages over its counterparts. First, the CF/DPF framework is suitable for scenarios where network connectivity is intermittent and consensus can not be reached between two consecutive observations. Second, the CF/DPF is not limited to the Gaussian approximation for the global posterior density. A third contribution of the paper is the derivation of the optimal posterior Cram\\'er-Rao lower bound (PCRLB) for the distributed arc...

  16. Modeling integrated water user decisions in intermittent supply systems

    Science.gov (United States)

    Rosenberg, David E.; Tarawneh, Tarek; Abdel-Khaleq, Rania; Lund, Jay R.

    2007-07-01

    We apply systems analysis to estimate household water use in an intermittent supply system considering numerous interdependent water user behaviors. Some 39 household actions include conservation; improving local storage or water quality; and accessing sources having variable costs, availabilities, reliabilities, and qualities. A stochastic optimization program with recourse decisions identifies the infrastructure investments and short-term coping actions a customer can adopt to cost-effectively respond to a probability distribution of piped water availability. Monte Carlo simulations show effects for a population of customers. Model calibration reproduces the distribution of billed residential water use in Amman, Jordan. Parametric analyses suggest economic and demand responses to increased availability and alternative pricing. It also suggests potential market penetration for conservation actions, associated water savings, and subsidies to entice further adoption. We discuss new insights to size, target, and finance conservation.

  17. Determination of the structure factor of simple liquid metals from the pseudopotential theory and optimized random-phase approximation: Application to Al and Ga

    Science.gov (United States)

    Bretonnet, J. L.; Regnaut, C.

    1985-04-01

    We present the results of calculations of the static structure factor S(q) of liquid Al and Ga at the melting point. These calculations were motivated because many simple liquid metals exhibit structure anomalies taking the form of a shoulder on the main peak or even an asymmetry in the peak itself, while other liquid metals are correctly predicted by the standard models of liquid structure. Al and Ga have similar valence, electronic density, and size of their ionic radius; therefore, their pair potentials are somewhat similar. Despite this, their structure factors display most of the differences that can be observed among the variety of liquid metals. Starting from the Shaw optimized model potential [Phys. Rev. 174, 769 (1968)], a pair potential is constructed. A comparative examination of the electron-gas response function of Vashishta and Singwi [Phys. Rev. B 6, 875 (1972)] and of Ichimaru and Utsumi [Phys. Rev. B 24, 7385 (1981)] is carried out. Different depletion hole distributions are also used and full nonlocality is taken into account through effective masses. So S(q) is calculated by means of the optimized random-phase approximation. Particular attention is also devoted to the low-q region. By comparison with Monte Carlo computation, we show the limitation of various thermodynamic perturbation methods, such as the random-phase approximation or the soft-sphere model. The study of S(q) provides a stringent test of the model potential, where the electron-ion pseudopotential and the local-field correction are of prime importance, but where effective masses and depletion hole distribution may also have a role to play.

  18. A Simulation Optimization Algorithm for CTMDPs Based on Randomized Stationary Policies%CTMDP基于随机平稳策略的仿真优化算法

    Institute of Scientific and Technical Information of China (English)

    唐昊; 奚宏生; 殷保群

    2004-01-01

    基于Markov性能势理论和神经元动态规划(NDP)方法,研究一类连续时间Markov决策过程(MDP)在随机平稳策略下的仿真优化问题,给出的算法是把一个连续时间过程转换成其一致化Markov链,然后通过其单个样本轨道来估计平均代价性能指标关于策略参数的梯度,以寻找次优策略,该方法适合于解决大状态空间系统的性能优化问题.并给出了一个受控Markov过程的数值实例.%Based on the theory of Markov performance potentials and neuro-dynamic programming (NDP) methodology, we study simulation optimization algorithm for a class of continuous time Markov decision processes (CTMDPs) under randomized stationary policies. The proposed algorithm will estimate the gradient of average cost performance measure with respect to policy parameters by transforming a continuous time Markov process into a uniform Markov chain and simulating a single sample path of the chain. The goal is to look for a suboptimal randomized stationary policy. The algorithm derived here can meet the needs of performance optimization of many difficult systems with large-scale state space. Finally, a numerical example for a controlled Markov process is provided.

  19. Optimization of vitamin suppletion after Roux-en-Y gastric bypass surgery can lower postoperative deficiencies: a randomized controlled trial.

    Science.gov (United States)

    Dogan, Kemal; Aarts, Edo O; Koehestanie, Parweez; Betzel, Bark; Ploeger, Nadine; de Boer, Hans; Aufenacker, Theo J; van Laarhoven, Kees J H M; Janssen, Ignace M C; Berends, Frits J

    2014-11-01

    Iron, vitamin B12, and folic acid deficiencies are among the most common deficiencies occurring after laparoscopic Roux-en-Y gastric bypass (LRYGB). The present study evaluates the effectiveness of a specially designed multivitamin supplement (WLS Forte, FitForMe, Rotterdam, the Netherlands) specifically developed for LRYGB patients.A triple-blind, randomized, 12-month study was conducted comparing WLS forte with a standard multivitamin supplement (sMVS) containing approximately 100% of the recommended daily allowance (RDA) for iron, vitamin B12, and folic acid. WLS Forte contains vitamin B12 14000% RDA, iron 500% RDA, and folic acid 300% RDA.In total, 148 patients (74 in each group) underwent a LRYGB procedure. Baseline characteristics were similar for both groups. Per protocol analysis demonstrated that sMVS treatment was associated with a decline in ferritin (-24.4 ± 70.1 μg/L) and vitamin B12 (-45.9 ± 150.3 pmol/L) over 12 months, whereas in WLS Forte patients, ferritin remained stable (+3.2 ± 93.2 μg/L) and vitamin B12 increased significantly (+55.1 ± 144.2 pmol/L). The number of patients developing ferritin or vitamin B12 deficiency was significantly lower with WLS Forte compared with sMVS (P vitamin B12 deficiencies after LRYGB.

  20. Polarimetric SAR decomposition parameter subset selection and their optimal dynamic range evaluation for urban area classification using Random Forest

    Science.gov (United States)

    Hariharan, Siddharth; Tirodkar, Siddhesh; Bhattacharya, Avik

    2016-02-01

    Urban area classification is important for monitoring the ever increasing urbanization and studying its environmental impact. Two NASA JPL's UAVSAR datasets of L-band (wavelength: 23 cm) were used in this study for urban area classification. The two datasets used in this study are different in terms of urban area structures, building patterns, their geometric shapes and sizes. In these datasets, some urban areas appear oriented about the radar line of sight (LOS) while some areas appear non-oriented. In this study, roll invariant polarimetric SAR decomposition parameters were used to classify these urban areas. Random Forest (RF), which is an ensemble decision tree learning technique, was used in this study. RF performs parameter subset selection as a part of its classification procedure. In this study, parameter subsets were obtained and analyzed to infer scattering mechanisms useful for urban area classification. The Cloude-Pottier α, the Touzi dominant scattering amplitude αs1 and the anisotropy A were among the top six important parameters selected for both the datasets. However, it was observed that these parameters were ranked differently for the two datasets. The urban area classification using RF was compared with the Support Vector Machine (SVM) and the Maximum Likelihood Classifier (MLC) for both the datasets. RF outperforms SVM by 4% and MLC by 12% in Dataset 1. It also outperforms SVM and MLC by 3.5% and 11% respectively in Dataset 2.

  1. A Randomized Comparative Study of Two Techniques to Optimize the Root Coverage Using a Porcine Collagen Matrix.

    Science.gov (United States)

    Reino, Danilo Maeda; Maia, Luciana Prado; Fernandes, Patrícia Garani; Souza, Sergio Luis Scombatti de; Taba Junior, Mario; Palioto, Daniela Bazan; Grisi, Marcio Fermandes de Moraes; Jr, Arthur Belém Novaes

    2015-10-01

    The aim of this randomized controlled clinical study was to compare the extended flap technique (EFT) with the coronally advanced flap technique (CAF) using a porcine collagen matrix (PCM) for root coverage. Twenty patients with two bilateral gingival recessions, Miller class I or II on non-molar teeth were treated with CAF+PCM (control group) or EFT+PCM (test group). Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized tissue height (KTH), keratinized mucosa thickness (KMT) were determined at baseline, 3 and 6 months post-surgery. At 6 months, the mean root coverage for test group was 81.89%, and for control group it was 62.80% (p<0.01). The change of recession depth from baseline was statistically significant between test and control groups, with an mean of 2.21 mm gained at the control sites and 2.84 mm gained at the test sites (p=0.02). There were no statistically significant differences for KTH, PPD or CAL comparing the two therapies. The extended flap technique presented better root coverage than the coronally advanced flap technique when PCM was used.

  2. Estudo prospectivo e randomizado entre cardioplegia sangüínea com reperfusão quente (37ºC e o pinçamento intermitente da aorta na revascularização do miocárdio Randomized controlled trial between blood cardioplegia with warm reperfusion and intermittent aortic cross-clamping in myocardial revascularization

    Directory of Open Access Journals (Sweden)

    Luís Roberto Gerola

    1991-08-01

    Full Text Available No Instituto do Coração, foi realizado um estudo prospectivo e randomizado entre a utilização de cardioplegia sangüínea com reperfusão aquecida e enriquecida com aspartate e glutamato e o pinçamento intermitente da aorta na revascularização do miocárdio. Sessenta pacientes foram operados, sendo 30 com cardioplegia (Grupo C e 30 com pinçamento intermitente da aorta (Grupo P. Não houve diferenças quanto aos antecedentes patológicos e as condiçõs clínicas pré-operatórias. Quinze pacientes estavam em classe funcional III ou IV (Angina no grupo C e 20 no grupo P. Seis pacientes apresentavam aneurisma do ventrículo esquerdo, três em cada grupo, e nove pacientes eram reoperações. No grupo C foi realizada uma média de 2,93 enxertos por paciente e no grupo P de 3,13. O tempo de circulação extracorpórea no grupo P foi de 85 ± 23 min e no grupo C de 100 ± 2 8 min (p A prospective and randomized study was performed to compare blood cardioplegia with warm reperfusion to intermittent aortic cross-clamping in the myocardial revascularization. Sixty patients were operated upon, 30 with blood cardioplegia (Group I and 30 with aortic cross-clamping (Group II. There were no differences between the two groups in regard to preoperative data. Fifteen patients were in NYHA class III or IV (angina in the group I and 20 patients in the group II. Six patients had left ventricular aneurysms, three in each group. An average number of 2.93 grafts per patient were performed in the group I and 3.13 in the group II. The cardiopulmonary bypass time was 85 ± 23 min in the group II and 100 ± 28 min in the group I (p < 0.05. The aortic cross-clamping time was 44.3 ± 14.9 min in the group II and 62.8 ± 24.5 min in the group I (p < 0.01. The average ischemic time per anastomosis in the group II was 8.6 ± 2.2 min. The postoperative variations of the cardiac index, left ventricular stroke work index and right ventricular stroke work index were

  3. Electricity generation by intermittent sources

    Science.gov (United States)

    Wagner, F.

    2015-08-01

    This paper deals with the production of electricity by wind and photovoltaic (PV) power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES) instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  4. Electricity generation by intermittent sources

    Directory of Open Access Journals (Sweden)

    Wagner F.

    2015-01-01

    Full Text Available This paper deals with the production of electricity by wind and photovoltaic (PV power mostly in Germany. The German data of 2012 are scaled to a 100% supply of the electricity consumption by renewable sources. Wind and PV power are mixed in a ratio which minimises back-up energy. The 100%, optimal mix data are used to identify the powers to be installed, the accumulating backup and surplus energies, the size of storage to replace thermal back-up power, the possibilities of demand-side-management, and the specific CO2 production. The benefits of using an EU-wide field of renewable energies (RES instead of the national one are quantified and the interconnection capacities specified. Finally, the costs of installing RES are discussed. The conclusion is that a 100% supply by RES may not be meaningful. Large-scale supply by RES alone has deficiencies and it will remain a major task for science and technology to either improve such a system or find a suitable replacement.

  5. Optimizing PMTCT service delivery in rural North-Central Nigeria: protocol and design for a cluster randomized study.

    Science.gov (United States)

    Aliyu, Muktar H; Blevins, Meridith; Audet, Carolyn; Shepherd, Bryan E; Hassan, Adiba; Onwujekwe, Obinna; Gebi, Usman I; Kalish, Marcia; Lindegren, Mary Lou; Vermund, Sten H; Wester, C William

    2013-09-01

    Nigeria has more HIV-infected women who do not receive needed services for the prevention of mother-to-child transmission of HIV (PMTCT) than any other nation in the world. To meet the UNAIDS/WHO goal of eliminating mother-to-child HIV transmission by 2015, multiple interventions will be required to scale up PMTCT services, especially to lower-level, rural health facilities. To address this, we are conducting a cluster-randomized controlled study to evaluate the impact and cost-effectiveness of a novel, family-focused integrated package of PMTCT services. A systematic re-assignment of patient care responsibilities coupled with the adoption of point-of-care CD4 + cell count testing could facilitate the ability of lower-cadre health providers to manage PMTCT care, including the provision and scale-up of antiretroviral therapy (ART) to pregnant women in rural settings. Additionally, as influential community members, male partners could support their partners' uptake of and adherence to PMTCT care. We describe an innovative approach to scaling up PMTCT service provision that incorporates considerations of where and from whom women can access services (task-shifting), ease of obtaining a CD4 + cell count result (point-of-care testing), the degree of HIV service integration for HIV-infected women and their infants, and the level of family and community involvement (specifically male partner involvement). This systematic approach, if proven feasible and effective, could be scaled up in Nigeria and similar resource-limited settings as a means to accelerate progress toward eliminating mother-to-child transmission of HIV and help women with HIV infection take ART and live long, healthy lives (Trial registration: NCT01805752).

  6. Treatment of Metabolic syndrome by combination of physical activity and diet needs an optimal protein intake: a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Dutheil Frédéric

    2012-09-01

    Full Text Available Abstract Background The recommended dietary allowance (RDA for protein intake has been set at 1.0-1.3 g/kg/day for senior. To date, no consensus exists on the lower threshold intake (LTI = RDA/1.3 for the protein intake (PI needed in senior patients ongoing both combined caloric restriction and physical activity treatment for metabolic syndrome. Considering that age, caloric restriction and exercise are three increasing factors of protein need, this study was dedicated to determine the minimal PI in this situation, through the determination of albuminemia that is the blood marker of protein homeostasis. Methods Twenty eight subjects (19 M, 9 F, 61.8 ± 6.5 years, BMI 33.4 ± 4.1 kg/m2 with metabolic syndrome completed a three-week residential programme (Day 0 to Day 21 controlled for nutrition (energy balance of −500 kcal/day and physical activity (3.5 hours/day. Patients were randomly assigned in two groups: Normal-PI (NPI: 1.0 g/kg/day and High-PI (HPI: 1.2 g/kg/day. Then, patients returned home and were followed for six months. Albuminemia was measured at D0, D21, D90 and D180. Results At baseline, PI was spontaneously 1.0 g/kg/day for both groups. Albuminemia was 40.6 g/l for NPI and 40.8 g/l for HPI. A marginal protein under-nutrition appeared in NPI with a decreased albuminemia at D90 below 35 g/l (34.3 versus 41.5 g/l for HPI, p  Conclusion During the treatment based on restricted diet and exercise in senior people with metabolic syndrome, the lower threshold intake for protein must be set at 1.2 g/kg/day to maintain blood protein homeostasis.

  7. A stochastic space-time model for intermittent precipitation occurrences

    KAUST Repository

    Sun, Ying

    2016-01-28

    Modeling a precipitation field is challenging due to its intermittent and highly scale-dependent nature. Motivated by the features of high-frequency precipitation data from a network of rain gauges, we propose a threshold space-time t random field (tRF) model for 15-minute precipitation occurrences. This model is constructed through a space-time Gaussian random field (GRF) with random scaling varying along time or space and time. It can be viewed as a generalization of the purely spatial tRF, and has a hierarchical representation that allows for Bayesian interpretation. Developing appropriate tools for evaluating precipitation models is a crucial part of the model-building process, and we focus on evaluating whether models can produce the observed conditional dry and rain probabilities given that some set of neighboring sites all have rain or all have no rain. These conditional probabilities show that the proposed space-time model has noticeable improvements in some characteristics of joint rainfall occurrences for the data we have considered.

  8. An Ant Colony Optimization algorithm for solving the fixed destination multi-depot multiple traveling salesman problem with non-random parameters

    Science.gov (United States)

    Ramadhani, T.; Hertono, G. F.; Handari, B. D.

    2017-07-01

    The Multiple Traveling Salesman Problem (MTSP) is the extension of the Traveling Salesman Problem (TSP) in which the shortest routes of m salesmen all of which start and finish in a single city (depot) will be determined. If there is more than one depot and salesmen start from and return to the same depot, then the problem is called Fixed Destination Multi-depot Multiple Traveling Salesman Problem (MMTSP). In this paper, MMTSP will be solved using the Ant Colony Optimization (ACO) algorithm. ACO is a metaheuristic optimization algorithm which is derived from the behavior of ants in finding the shortest route(s) from the anthill to a form of nourishment. In solving the MMTSP, the algorithm is observed with respect to different chosen cities as depots and non-randomly three parameters of MMTSP: m, K, L, those represents the number of salesmen, the fewest cities that must be visited by a salesman, and the most number of cities that can be visited by a salesman, respectively. The implementation is observed with four dataset from TSPLIB. The results show that the different chosen cities as depots and the three parameters of MMTSP, in which m is the most important parameter, affect the solution.

  9. Optimal production lot size and reorder point of a two-stage supply chain while random demand is sensitive with sales teams' initiatives

    Science.gov (United States)

    Sankar Sana, Shib

    2016-01-01

    The paper develops a production-inventory model of a two-stage supply chain consisting of one manufacturer and one retailer to study production lot size/order quantity, reorder point sales teams' initiatives where demand of the end customers is dependent on random variable and sales teams' initiatives simultaneously. The manufacturer produces the order quantity of the retailer at one lot in which the procurement cost per unit quantity follows a realistic convex function of production lot size. In the chain, the cost of sales team's initiatives/promotion efforts and wholesale price of the manufacturer are negotiated at the points such that their optimum profits reached nearer to their target profits. This study suggests to the management of firms to determine the optimal order quantity/production quantity, reorder point and sales teams' initiatives/promotional effort in order to achieve their maximum profits. An analytical method is applied to determine the optimal values of the decision variables. Finally, numerical examples with its graphical presentation and sensitivity analysis of the key parameters are presented to illustrate more insights of the model.

  10. Affinity Maturation of Monoclonal Antibody 1E11 by Targeted Randomization in CDR3 Regions Optimizes Therapeutic Antibody Targeting of HER2-Positive Gastric Cancer.

    Science.gov (United States)

    Ko, Bong-Kook; Choi, Soyoung; Cui, Lei Guang; Lee, Young-Ha; Hwang, In-Sik; Kim, Kyu-Tae; Shim, Hyunbo; Lee, Jong-Seo

    2015-01-01

    Anti-HER2 murine monoclonal antibody 1E11 has strong and synergistic anti-tumor activity in HER2-overexpressing gastric cancer cells when used in combination with trastuzumab. We presently optimized this antibody for human therapeutics. First, the complementarity determining regions (CDRs) of the murine antibody were grafted onto human germline immunoglobulin variable genes. No difference in affinity and biological activity was observed between chimeric 1E11 (ch1E11) and humanized 1E11 (hz1E11). Next, affinity maturation of hz1E11 was performed by the randomization of CDR-L3 and H3 residues followed by stringent biopanning selection. Milder selection pressure favored the selection of more diverse clones, whereas higher selection stringency resulted in the convergence of the panning output to a smaller number of clones with improved affinity. Clone 1A12 had four amino acid substitutions in CDR-L3, and showed a 10-fold increase in affinity compared to the parental clone and increased potency in an in vitro anti-proliferative activity assay with HER2-overepxressing gastric cancer cells. Clone 1A12 inhibited tumor growth of NCI-N87 xenograft model with similar efficacy to trastuzumab alone, and the combination treatment of 1A12 and trastuzumab completely removed the established tumors. These results suggest that humanized and affinity matured monoclonal antibody 1A12 is a highly optimized molecule for future therapeutic development against HER2-positive tumors.

  11. Intermittent screening and treatment or intermittent preventive treatment with dihydroartemisinin-piperaquine versus intermittent preventive treatment with sulfadoxine-pyrimethamine for the control of malaria during pregnancy in western Kenya: an open-label, three-group, randomised controlled superiority trial.

    Science.gov (United States)

    Desai, Meghna; Gutman, Julie; L'lanziva, Anne; Otieno, Kephas; Juma, Elizabeth; Kariuki, Simon; Ouma, Peter; Were, Vincent; Laserson, Kayla; Katana, Abraham; Williamson, John; ter Kuile, Feiko O

    2015-12-19

    Every year, more than 32 million pregnancies in sub-Saharan Africa are at risk of malaria infection and its adverse consequences. The effectiveness of the intermittent preventive treatment with sulfadoxine-pyrimethamine strategy recommended by WHO is threatened by high levels of parasite resistance. We aimed to assess the efficacy and safety of two alternative strategies: intermittent screening with malaria rapid diagnostic tests and treatment of women who test positive with dihydroartemisinin-piperaquine, and intermittent preventive treatment with dihydroartemisinin-piperaquine. We did this open-label, three-group, randomised controlled superiority trial at four sites in western Kenya with high malaria transmission and sulfadoxine-pyrimethamine resistance. HIV-negative pregnant women between 16 and 32 weeks' gestation were randomly assigned (1:1:1), via computer-generated permuted-block randomisation (block sizes of three, six, and nine), to receive intermittent screening and treatment with dihydroartemisinin-piperaquine, intermittent preventive treatment with dihydroartemisinin-piperaquine, or intermittent preventive treatment with sulfadoxine-pyrimethamine. Study participants, study clinic nurses, and the study coordinator were aware of treatment allocation, but allocation was concealed from study investigators, delivery unit nurses, and laboratory staff. The primary outcome was malaria infection at delivery, defined as a composite of peripheral or placental parasitaemia detected by placental histology, microscopy, or rapid diagnostic test. The primary analysis was by modified intention to treat. This study is registered with ClinicalTrials.gov, number NCT01669941. Between Aug 21, 2012, and June 19, 2014, we randomly assigned 1546 women to receive intermittent screening and treatment with dihydroartemisinin-piperaquine (n=515), intermittent preventive treatment with dihydroartemisinin-piperaquine (n=516), or intermittent preventive treatment with sulfadoxine

  12. Primary care management for optimized antithrombotic treatment [PICANT]: study protocol for a cluster-randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Siebenhofer Andrea

    2012-08-01

    Full Text Available Abstract Background Antithrombotic treatment is a continuous therapy that is often performed in general practice and requires careful safety management. The aim of this study is to investigate whether a best-practice model that applies major elements of case management and patient education, can improve antithrombotic management in primary healthcare in terms of reducing major thromboembolic and bleeding events. Methods This 24-month cluster-randomized trial will be performed with 690 adult patients from 46 practices. The trial intervention will be a complex intervention involving general practitioners, healthcare assistants, and patients with an indication for oral anticoagulation. To assess adherence to medication and symptoms in patients, as well as to detect complications early, healthcare assistants will be trained in case management and will use the Coagulation-Monitoring List (Co-MoL to regularly monitor patients. Patients will receive information (leaflets and a video, treatment monitoring via the Co-MoL and be motivated to perform self-management. Patients in the control group will continue to receive treatment as usual from their general practitioners. The primary endpoint is the combined endpoint of all thromboembolic events requiring hospitalization and all major bleeding complications. Secondary endpoints are mortality, hospitalization, strokes, major bleeding and thromboembolic complications, severe treatment interactions, the number of adverse events, quality of anticoagulation, health-related quality of life, and costs. Further secondary objectives will be investigated to explain the mechanism by which the intervention is effective: patients’ assessment of chronic illness care, self-reported adherence to medication, general practitioners’ and healthcare assistants’ knowledge, and patients’ knowledge and satisfaction with shared decision making. Practice recruitment is expected to take place between July and December 2012

  13. Insights from intermittent binocular rivalry and EEG

    Directory of Open Access Journals (Sweden)

    Michael A Pitts

    2011-09-01

    Full Text Available Novel stimulation and analytical approaches employed in EEG studies of ambiguous figures have recently been applied to binocular rivalry. The combination of intermittent stimulus presentation and EEG source imaging has begun to shed new light on the neural underpinnings of binocular rivalry. Here, we review the basics of the intermittent paradigm and highlight methodological issues important for interpreting previous results and designing future experiments. We then outline current analytical approaches, including EEG microstates, event-related potentials, and statistically-based source estimation, and propose a spatio-temporal model that integrates findings from several studies. Finally, we discuss the advantages and limitations of using binocular rivalry as a tool to investigate the neural basis of perceptual awareness.

  14. Towards an intermittency-friendly energy system

    DEFF Research Database (Denmark)

    Blarke, Morten

    2012-01-01

    . However, well-designed heat pump concepts are more cost-effective than electric boilers, and in future markets where the gas/electricity price ratio is likely to increase, compression heat pumps in combination with intermediate thermal storages represent a superior potential for combining an intermittency-friendly...... are capitulating as wind power penetration levels are moving above 25%; some operators are retiring cogeneration units entirely, while other operators are making way for heat-only boilers. This development is jeopardizing the system-wide energy, economic, and environmental benefits that distributed cogeneration...... using low-temperature heat recovered from flue gasses in combination with an intermediate cold storage, which enables the independent operation of heat pump and cogenerator. It is found that an electric boiler provides consistent improvements in the intermittency-friendliness of distributed cogeneration...

  15. INTERMITTENCY AND SCALING IN TURBULENT CONVECTION

    Institute of Scientific and Technical Information of China (English)

    Emily S. C. CHING

    2003-01-01

    Both the velocity and temperature measurements taken in turbulent Rayleigh-B'enard convection experiments have been analyzed. It is found that both the velocity and temperature fluctuations are intermittent and can be well-described by the She-Leveque hierarchical structure. A positive correlation between the vertical velocity and the temperature differences is found both at the center,near the sidewall and near the bottom of the convection cell, supporting that buoyancy is significant in the Bolgiano regime. Moreover, the intermittent nature of the temperature fluctuations in the Bolgiano regime can be attributed to the variations in the temperature dissipation rate. However, the relations between the velocity and temperature structure functions and their correlations implied by the Bolgiano-Obukhov scaling are not supported by experimental measurements.

  16. Impact of syllable stress and phonetic context on the distribution of intermittent aphonia.

    Science.gov (United States)

    Iwarsson, Jenny; Fredsø, Julie

    2014-10-01

    The occurrence of intermittent aphonia, perceived as sudden interruptions of voicing in connected speech, often reflects high stiffness of the vocal fold mucosa as part of a voice disorder. This retrospective study aimed to investigate the overarching hypothesis that the aphonic instances in voices with intermittent aphonia are not totally randomly appearing, but related to syllable stress and phonetic context. Recordings of 31 dysphonic patients with intermittent aphonia reading a standard text were analyzed perceptually. All vowels of the text were labelled and categorized with regard to syllable stress and character of the phoneme preceding the vowel. The occurrence of aphonic instances within each syllable category was analyzed. Four different hypotheses were formulated and analyzed by the non-parametric Wilcoxon's signed-ranks test. The results showed a significantly higher occurrence of aphonic instances in unstressed syllables as opposed to stressed, in vowels following an unvoiced phoneme as opposed to a voiced, and in vowels following two or more unvoiced phonemes as opposed to one unvoiced phoneme. No significant difference was found between vowels following aspirated stops [p], [t], [k] as opposed to unaspirated stops [b], [d], [g]. The findings support the theory that both physiological and functional aspects may contribute to the phenomenon of intermittent aphonia.

  17. Intermittency transition to generalized synchronization in coupled time-delay systems.

    Science.gov (United States)

    Senthilkumar, D V; Lakshmanan, M

    2007-12-01

    We report the nature of the transition to generalized synchronization (GS) in a system of two coupled scalar piecewise linear time-delay systems using the auxiliary system approach. We demonstrate that the transition to GS occurs via an on-off intermittency route and that it also exhibits characteristically distinct behaviors for different coupling configurations. In particular, the intermittency transition occurs in a rather broad range of coupling strength for the error feedback coupling configuration and in a narrow range of coupling strength for the direct feedback coupling configuration. It is also shown that the intermittent dynamics displays periodic bursts of periods equal to the delay time of the response system in the former case, while they occur in random time intervals of finite duration in the latter case. The robustness of these transitions with system parameters and delay times has also been studied for both linear and nonlinear coupling configurations. The results are corroborated analytically by suitable stability conditions for asymptotically stable synchronized states and numerically by the probability of synchronization and by the transition of sub-Lyapunov exponents of the coupled time-delay systems. We have also indicated the reason behind these distinct transitions by referring to the unstable periodic orbit theory of intermittency synchronization in low-dimensional systems.

  18. The effect of an intermittent, high-intensity warm-up on supramaximal kayak ergometer performance.

    Science.gov (United States)

    Bishop, David; Bonetti, Darrel; Spencer, Matthew

    2003-01-01

    It has previously been shown that the metabolic acidaemia induced by a continuous warm-up at the 'lactate threshold' is associated with a reduced accumulated oxygen deficit and decreased supramaximal performance. The aim of this study was to determine if an intermittent, high-intensity warm-up could increase oxygen uptake (VO2) without reducing the accumulated oxygen deficit, and thus improve supramaximal performance. Seven male 500 m kayak paddlers, who had represented their state, volunteered for this study. Each performed a graded exercise test to determine VO2max and threshold parameters. On subsequent days and in a random, counterbalanced order, the participants then performed a continuous or intermittent, high-intensity warm-up followed by a 2 min, all-out kayak ergometer test. The continuous warm-up consisted of 15 min of exercise at approximately 65% VO2max. The intermittent, high-intensity warm-up was similar, except that the last 5 min was replaced with five 10 s sprints at 200% VO2max, separated by 50 s of recovery at approximately 55% VO2max. Significantly greater (P kayak ergometer performance is significantly better after an intermittent rather than a continuous warm-up.

  19. Time to exhaustion at continuous and intermittent maximal lactate steady state during running exercise.

    Science.gov (United States)

    Dittrich, Naiandra; de Lucas, Ricardo Dantas; Beneke, Ralph; Guglielmo, Luiz Guilherme

    2014-09-01

    The purpose of this study was to determine and compare the time to exhaustion (TE) and the physiological responses at continuous and intermittent (ratio 5:1) maximal lactate steady state (MLSS) in well-trained runners. Ten athletes (32.7 ± 6.9 y, VO2max 61.7 ± 3.9 mL · kg-1 · min-1) performed an incremental treadmill test, three to five 30-min constant-speed tests to determine the MLSS continuous and intermittent (5 min of running, interspaced by 1 min of passive rest), and 2 randomized TE tests at such intensities. Two-way ANOVA with repeated measures was used to compare the changes in physiological variables during the TE tests and between continuous and intermittent exercise. The intermittent MLSS velocity (MLSSint = 15.26 ± 0.97 km/h) was higher than in the continuous model (MLSScon = 14.53 ± 0.93 km/h), while the TE at MLSScon was longer than MLSSint (68 ± 11 min and 58 ± 15 min, P heart rate, ventilation, and rating of perceived exertion presented a significant increase in the last portion of the tests. The results showed a higher tolerance to exercising during MLSScon than during MLSSint in trained runners. Thus, the training volume of an extensive interval session (ratio 5:1) designed at MLSS intensity should take into consideration this higher speed at MLSS and also the lower TE than with continuous exercise.

  20. Bladder calculi complicating intermittent clean catheterization.

    Science.gov (United States)

    Amendola, M A; Sonda, L P; Diokno, A C; Vidyasagar, M

    1983-10-01

    Eight male patients on clean intermittent catheterization programs for neurogenic bladder dysfunction developed vesical calculi around pubic hairs inadvertently introduced into the bladder, acting as a nidus for incrustation. In three patients, the radiographic appearance of serpentine calcifications in the pelvis was highly consistent with calcareous deposits on strands of hair. Familiarity with this radiologic appearance should suggest the diagnosis in the appropriate clinical setting and help avoid misinterpretation of these calcifications, atypical of usual bladder stones.

  1. Intermittent chaotic chimeras for coupled rotators.

    Science.gov (United States)

    Olmi, Simona; Martens, Erik A; Thutupalli, Shashi; Torcini, Alessandro

    2015-09-01

    Two symmetrically coupled populations of N oscillators with inertia m display chaotic solutions with broken symmetry similar to experimental observations with mechanical pendulums. In particular, we report evidence of intermittent chaotic chimeras, where one population is synchronized and the other jumps erratically between laminar and turbulent phases. These states have finite lifetimes diverging as a power law with N and m. Lyapunov analyses reveal chaotic properties in quantitative agreement with theoretical predictions for globally coupled dissipative systems.

  2. AN ELDERLY WOMAN WITH INTERMITTENT CLAUDICATION

    Directory of Open Access Journals (Sweden)

    Nayyer Naveed Wazir

    2006-01-01

    Full Text Available This case report illustrates the misdiagnosis of intermittent claudication in an elderly with multiple cardiac risk factors. Careful clinical evaluation and imaging shifts the diagnosis from peripheral vascular disease to spinal stenosis. The decision whether to offer conservative therapy or proceed to spinal surgery requires an accurate assessment of the severity of the symptoms without ignoring the important role of patient preferences.

  3. Cardiac calcification in acute intermittent porphyria

    Directory of Open Access Journals (Sweden)

    Tanmoy Ghatak

    2011-01-01

    Full Text Available Aetiology of pericardial calcifications can be multifactorial. Tuberculosis has been reported as the most common cause. Other known causes include uraemia, asbestosis, post-traumatic or postoperative. We report a rare case of pericardial calcification seen in a patient with established acute intermittent porphyria. A direct causal relationship cannot be established between porphyria and pericardial calcification, but it may be due to deposition of the porphyrin in the pericardium.

  4. Treatment of febrile seizures with intermittent clobazam

    OpenAIRE

    1997-01-01

    Fifty children, 24 female and 26 male, with ages varying from 6 to 72 months (mean=23.7 m.) that experienced at least one febrile seizure (FS) entered a prospective study of intermittent therapy with clobazam. Cases with severe neurological abnormalities, progressive neurological disease, afebrile seizures, symptomatic seizures of other nature, or seizures during a central nervous system infection were excluded. Seizures were of the simple type in 25 patients, complex in 20 and unclassified i...

  5. Intermittent radio galaxies and source statistics

    CERN Document Server

    Reynolds, C S

    1997-01-01

    We suggest that extragalactic radio sources are intermittent on timescales of 10^4-10^5 yr. Using a simple spherical model of a cocoon/shock system, it is found that inactive sources fade rapidly in radio luminosity but the shock in the ambient medium continues to expand supersonically, thereby keeping the whole source structure intact during the inactive phases. The fading of inactive sources, and the effect of the intermittency on the expansion velocity, can readily explain the observed over-abundance of small radio sources. In particular, the plateau in the observed distribution of sizes found by O'Dea & Baum (1997) can be interpreted as being due to intermittency. The model predicts that very young sources will be particularly radio luminous, once the effects of absorption have been accounted for. Furthermore, it predicts the existence of a significant number of faint `coasting' sources. These might be detectable in deep, low-frequency radio maps, or via the X-ray and optical emission line properties ...

  6. Role of the latest endovascular technology in the treatment of intermittent claudication

    Directory of Open Access Journals (Sweden)

    Ichihashi S

    2014-06-01

    Full Text Available Shigeo Ichihashi, Kimihiko Kichikawa Department of Radiology, Nara Medical University, Kashihara, Nara, Japan Abstract: Intermittent claudication is a serious symptom in patients with peripheral arterial disease, and severely limits activities of daily living. Conservative treatment (optimal medical therapy and exercise rehabilitation programs and revascularization procedures (endovascular treatment [EVT] or open bypass surgery can relieve intermittent claudication. Among these treatment options, EVT has developed dramatically during the past decade, and has enabled physicians to offer less invasive treatment options with increasing durability. EVT for aortoiliac lesions has matured, and its long-term patency now approaches that of open bypass surgery. The latest EVT technologies include drug-eluting stents, stent grafts, drug-coated balloons, and bioresorbable stents. The recently reported patency of stent grafts in the femoropopliteal lesions was comparable with that of the prosthetic bypass graft. In the course of the paradigm shift from bypass surgery to EVT, evidence of any long-term benefit of EVT compared with supervised exercise is still inconclusive. EVT could improve walking performance in the short-term, while supervised exercise could improve walking performance more efficiently in the long-term. Combined treatment with EVT and exercise may offer the most sustainable and effective symptom relief. This paper reviews the relevant literature on the treatment of intermittent claudication, focusing on the latest EVT technologies, and outlines a strategy for achieving long-term benefits. Keywords: endovascular treatment, intermittent claudication, peripheral arterial disease, stent, exercise therapy

  7. ImOSM: intermittent evolution and robustness of phylogenetic methods.

    Science.gov (United States)

    Thi Nguyen, Minh Anh; Gesell, Tanja; von Haeseler, Arndt

    2012-02-01

    Among the criteria to evaluate the performance of a phylogenetic method, robustness to model violation is of particular practical importance as complete a priori knowledge of evolutionary processes is typically unavailable. For studies of robustness in phylogenetic inference, a utility to add well-defined model violations to the simulated data would be helpful. We therefore introduce ImOSM, a tool to imbed intermittent evolution as model violation into an alignment. Intermittent evolution refers to extra substitutions occurring randomly on branches of a tree, thus changing alignment site patterns. This means that the extra substitutions are placed on the tree after the typical process of sequence evolution is completed. We then study the robustness of widely used phylogenetic methods: maximum likelihood (ML), maximum parsimony (MP), and a distance-based method (BIONJ) to various scenarios of model violation. Violation of rates across sites (RaS) heterogeneity and simultaneous violation of RaS and the transition/transversion ratio on two nonadjacent external branches hinder all the methods recovery of the true topology for a four-taxon tree. For an eight-taxon balanced tree, the violations cause each of the three methods to infer a different topology. Both ML and MP fail, whereas BIONJ, which calculates the distances based on the ML estimated parameters, reconstructs the true tree. Finally, we report that a test of model homogeneity and goodness of fit tests have enough power to detect such model violations. The outcome of the tests can help to actually gain confidence in the inferred trees. Therefore, we recommend using these tests in practical phylogenetic analyses.

  8. Risk of Stroke in Patients with Stable Coronary Artery Disease Undergoing Percutaneous Coronary Intervention versus Optimal Medical Therapy: Systematic Review and Meta-Analysis of Randomized Controlled Trials

    Science.gov (United States)

    Taglieri, Nevio; Bacchi Reggiani, Maria Letizia; Ghetti, Gabriele; Saia, Francesco; Dall’Ara, Gianni; Gallo, Pamela; Moretti, Carolina; Palmerini, Tullio; Marrozzini, Cinzia; Marzocchi, Antonio; Rapezzi, Claudio

    2016-01-01

    Background Stroke is a rare but serious adverse event associated with percutaneous coronary intervention (PCI). However, the relative risk of stroke between stable patients undergoing a direct PCI strategy and those undergoing an initial optimal medical therapy (OMT) strategy has not been established yet. This study sought to investigate if, in patients with stable coronary artery disease (SCAD), an initial strategy PCI is associated with a higher risk of stroke than a strategy based on OMT alone. Methods We performed a meta-analysis of 6 contemporary randomized control trials in which 5673 patients with SCAD were randomized to initial PCI or OMT. Only trials with stent utilization more than 50% were included. Study endpoint was the rate of stroke during follow up. Results Mean age of patients ranged from 60 to 65 years and stent utilization ranged from 72% to 100%. Rate of stroke was 2.0% at a weighted mean follow up of 55.3 months. On pooled analysis, the risk of stroke was similar between patients undergoing a PCI plus OMT and those receiving only OMT (2.2% vs. 1.8%, OR on fixed effect = 1.24 95%CI: 0.85–1.79). There was no heterogeneity among the studies (I2 = 0.0%, P = 0.15). On sensitivity analysis after removing each individual study the pooled effect estimate remains unchanged. Conclusions In patients with SCAD an initial strategy based on a direct PCI is not associated with an increased risk of stroke during long-term follow up compared to an initial strategy based on OMT alone. PMID:27391212

  9. Risk of Stroke in Patients with Stable Coronary Artery Disease Undergoing Percutaneous Coronary Intervention versus Optimal Medical Therapy: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

    Directory of Open Access Journals (Sweden)

    Nevio Taglieri

    Full Text Available Stroke is a rare but serious adverse event associated with percutaneous coronary intervention (PCI. However, the relative risk of stroke between stable patients undergoing a direct PCI strategy and those undergoing an initial optimal medical therapy (OMT strategy has not been established yet. This study sought to investigate if, in patients with stable coronary artery disease (SCAD, an initial strategy PCI is associated with a higher risk of stroke than a strategy based on OMT alone.We performed a meta-analysis of 6 contemporary randomized control trials in which 5673 patients with SCAD were randomized to initial PCI or OMT. Only trials with stent utilization more than 50% were included. Study endpoint was the rate of stroke during follow up.Mean age of patients ranged from 60 to 65 years and stent utilization ranged from 72% to 100%. Rate of stroke was 2.0% at a weighted mean follow up of 55.3 months. On pooled analysis, the risk of stroke was similar between patients undergoing a PCI plus OMT and those receiving only OMT (2.2% vs. 1.8%, OR on fixed effect = 1.24 95%CI: 0.85-1.79. There was no heterogeneity among the studies (I2 = 0.0%, P = 0.15. On sensitivity analysis after removing each individual study the pooled effect estimate remains unchanged.In patients with SCAD an initial strategy based on a direct PCI is not associated with an increased risk of stroke during long-term follow up compared to an initial strategy based on OMT alone.

  10. Ranolazine versus placebo in patients with ischemic cardiomyopathy and persistent chest pain or dyspnea despite optimal medical and revascularization therapy: randomized, double-blind crossover pilot study

    Directory of Open Access Journals (Sweden)

    Shammas NW

    2015-03-01

    Full Text Available Nicolas W Shammas,1 Gail A Shammas,1 Kathleen Keyes,2 Shawna Duske,1 Ryan Kelly,1 Michael Jerin3 1Midwest Cardiovascular Research Foundation, 2Cardiovascular Medicine, Private Corporation, 3St Ambrose University, Davenport, IA, USA Background: Patients with ischemic cardiomyopathy (ICM may continue to experience persistent chest pain and/or dyspnea despite pharmacologic therapy and revascularization. We hypothesized that ranolazine would reduce anginal symptoms or dyspnea in optimally treated ICM patients.Methods: In this randomized, double-blind, crossover-design pilot study, 28 patients with ICM (ejection fraction less or equal 40% were included after providing informed consent. A total of 24 patients completed both placebo and ranolazine treatments and were analyzed. All patients were on treatment with a beta blocker, an angiotensin-converting enzyme inhibitor (or angiotensin receptor blocker, and at least one additional antianginal drug. After randomization, patients received up to 1,000 mg ranolazine orally twice a day, as tolerated, versus placebo. The primary end point was change in angina as assessed by the Seattle Angina Questionnaire (SAQ, or in dyspnea as assessed by the Rose Dyspnea Scale (RDS. Change in the RDS and SAQ score from baseline was compared, for ranolazine and placebo, using the Wilcoxon signed rank test or paired t-test.Results: Patients had the following demographic and clinical variables: mean age of 71.5 years; male (82.1%; prior coronary bypass surgery (67.9%; prior coronary percutaneous intervention (85.7%; prior myocardial infarction (82.1%; diabetes (67.9%; and mean ejection fraction of 33.1%. No statistical difference was seen between baseline RDS score and that after placebo or ranolazine (n=20 (P≥0.05. There was however, an improvement in anginal frequency (8/10 patients (P=0.058, quality of life (8/10 patients (P=0.048, and mean score of all components of the SAQ questionnaire (n=10 (P=0.047 with ranolazine

  11. Comparison of Urinary Tract Infection Rates Associated with Transurethral Catheterization, Suprapubic Tube and Clean Intermittent Catheterization in the Postoperative Setting: A Network Meta-Analysis.

    Science.gov (United States)

    Han, Christopher S; Kim, Sinae; Radadia, Kushan D; Zhao, Philip T; Elsamra, Sammy E; Olweny, Ephrem O; Weiss, Robert E

    2017-07-20

    We performed a network meta-analysis of available randomized, controlled trials to elucidate the risks of urinary tract infection associated with transurethral catheterization, suprapubic tubes and intermittent catheterization in the postoperative setting. PubMed®, EMBASE® and Google Scholar™ searches were performed for eligible randomized, controlled trials from January 1980 to July 2015 that included patients who underwent transurethral catheterization, suprapubic tube placement or intermittent catheterization at the time of surgery and catheterization lasting up to postoperative day 30. The primary outcome of comparison was the urinary tract infection rate via a network meta-analysis with random effects model using the netmeta package in R 3.2 (www.r-project.org/). Included in analysis were 14 randomized, controlled trials in a total of 1,391 patients. Intermittent catheterization and suprapubic tubes showed no evidence of decreased urinary tract infection rates compared to transurethral catheterization. Suprapubic tubes and intermittent catheterization had comparable urinary tract infection rates (OR 0.903, 95% CI 0.479-2.555). On subgroup analysis of 10 randomized, controlled trials with available mean catheterization duration data in a total of 928 patients intermittent catheterization and suprapubic tube were associated with significantly decreased risk of urinary tract infection compared to transurethral catheterization when catheterization duration was greater than 5 days (OR 0.173, 95% CI 0.073-0.412 and OR 0.142, 95% CI 0.073-0.276, respectively). Transurethral catheterization is not associated with an increased urinary tract infection risk compared to suprapubic tubes and intermittent catheterization if catheterization duration is 5 days or less. However, a suprapubic tube or intermittent catheterization is associated with a lower rate of urinary tract infection if longer term catheterization is expected in the postoperative period. Copyright

  12. Smoking patterns and stimulus control in intermittent and daily smokers.

    Directory of Open Access Journals (Sweden)

    Saul Shiffman

    Full Text Available Intermittent smokers (ITS - who smoke less than daily - comprise an increasing proportion of adult smokers. Their smoking patterns challenge theoretical models of smoking motivation, which emphasize regular and frequent smoking to maintain nicotine levels and avoid withdrawal, but yet have gone largely unexamined. We characterized smoking patterns among 212 ITS (smoking 4-27 days per month compared to 194 daily smokers (DS; smoking 5-30 cigarettes daily who monitored situational antecedents of smoking using ecological momentary assessment. Subjects recorded each cigarette on an electronic diary, and situational variables were assessed in a random subset (n=21,539 smoking episodes; parallel assessments were obtained by beeping subjects at random when they were not smoking (n=26,930 non-smoking occasions. Compared to DS, ITS' smoking was more strongly associated with being away from home, being in a bar, drinking alcohol, socializing, being with friends and acquaintances, and when others were smoking. Mood had only modest effects in either group. DS' and ITS' smoking were substantially and equally suppressed by smoking restrictions, although ITS more often cited self-imposed restrictions. ITS' smoking was consistently more associated with environmental cues and contexts, especially those associated with positive or "indulgent" smoking situations. Stimulus control may be an important influence in maintaining smoking and making quitting difficult among ITS.

  13. Intermittent But Not Continuous Static Stretching Improves Subsequent Vertical Jump Performance In Flexibility-Trained Athletes.

    Science.gov (United States)

    Bogdanis, Gregory C; Donti, Olyvia; Tsolakis, Charilaos; Smilios, Ilias; Bishop, David J

    2017-02-23

    This study examined changes in countermovement jump (CMJ) height after an intermittent or a continuous static stretching protocol of equal total duration. Sixteen male, elite-level gymnasts performed 90 s of intermittent (3 x 30 s with 30 s rest) or continuous stretching (90 s) of the quadriceps muscle. A single-leg stretching and jumping design was used, with the contra-lateral limb serving as a control. The same individuals performed both conditions with alternate legs in a randomized, counterbalanced order. One leg CMJ height was measured for the stretched and the control leg after warm-up, immediately after stretching, and at regular intervals for 10 min after stretching. Range of motion (ROM) of the hip and knee joints was measured before, after, and 10 min post-stretching. Compared to the control leg, intermittent stretching increased CMJ height by 8.1±2.0%, 4 min into recovery (+2.2±2.0 cm, 95%CI: 1.0-3.4 cm, p=0.001), while continuous stretching decreased CMJ height by 17.5±3.3% immediately after (-2.9±1.7 cm, 95%CI: -2.0 to -3.7 cm, p=0.001) and by 12.0±2.7% one min after stretching (-2.2±2.1 cm, 95%CI: -1.2 to -3.2 cm, p=0.001). The increases in hip (2.9 and 3.6, p=0.001. d=2.4) and knee joint ROM (5.1 and 6.1, p=0.001. d=0.85) after the intermittent and continuous stretching protocols were not different. The opposite effects of intermittent vs. continuous stretching on subsequent CMJ performance suggests that stretching mode is an important variable when examining the acute effects of static stretching on performance in flexibility-trained athletes.

  14. Functional electrical stimulation improves quality of life by reducing intermittent claudication.

    Science.gov (United States)

    Embrey, David G; Alon, Gad; Brandsma, Brenna A; Vladimir, Felix; Silva, Angela; Pflugeisen, Bethann M; Amoroso, Paul J

    2017-09-15

    To determine if Functional Electrical Stimulation (FES) would improve ischemic pain, walking distance, and quality of life of patients with intermittent claudication. Single blind, randomized block, two factorial design. Patients diagnosed with Peripheral Artery Disease (PAD) and intermittent claudication (IC). Ankle Brachial Index ranged 0.4-0.9 on at least one leg. Patients were randomly assigned to experimental (FES+Walk, N=13) or control (WALK, N=14) groups. Experimental group patients received FES to the dorsiflexor and plantarflexor muscles while walking for 1h/day, six days/week for eight weeks. Control group patients received similar intervention without FES. A Follow-up period of both groups lasted eight weeks. Outcome measures were taken at baseline (T0), after intervention (T1), and after follow-up (T2). Primary measures included Perceived Pain Intensity (PPI), Six minute walk (6MW), and Peripheral Arterial Disease Quality of Life (PADQOL). Secondary measures included Intermittent Claudication Questionnaire (ICQ) and Timed Up and Go (TUG). Group by time interactions in PPI were significant (Phttps://projectreporter.nih.gov/project_info_description.cfm?aid=8748641&icde=30695377&ddparam=&ddvalue=&ddsub=&cr=1&csb=default&cs=ASC. https://clinicaltrials.gov/ct2/show/NCT02384980?term=David+Embrey&rank=1. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  15. Parameter Identification with the Random Perturbation Particle Swarm Optimization Method and Sensitivity Analysis of an Advanced Pressurized Water Reactor Nuclear Power Plant Model for Power Systems

    Directory of Open Access Journals (Sweden)

    Li Wang

    2017-02-01

    Full Text Available The ability to obtain appropriate parameters for an advanced pressurized water reactor (PWR unit model is of great significance for power system analysis. The attributes of that ability include the following: nonlinear relationships, long transition time, intercoupled parameters and difficult obtainment from practical test, posed complexity and difficult parameter identification. In this paper, a model and a parameter identification method for the PWR primary loop system were investigated. A parameter identification process was proposed, using a particle swarm optimization (PSO algorithm that is based on random perturbation (RP-PSO. The identification process included model variable initialization based on the differential equations of each sub-module and program setting method, parameter obtainment through sub-module identification in the Matlab/Simulink Software (Math Works Inc., Natick, MA, USA as well as adaptation analysis for an integrated model. A lot of parameter identification work was carried out, the results of which verified the effectiveness of the method. It was found that the change of some parameters, like the fuel temperature and coolant temperature feedback coefficients, changed the model gain, of which the trajectory sensitivities were not zero. Thus, obtaining their appropriate values had significant effects on the simulation results. The trajectory sensitivities of some parameters in the core neutron dynamic module were interrelated, causing the parameters to be difficult to identify. The model parameter sensitivity could be different, which would be influenced by the model input conditions, reflecting the parameter identifiability difficulty degree for various input conditions.

  16. UNSTEADY INTERMITTENT FLOW IN A ROTATING CURVED PIPE

    Institute of Scientific and Technical Information of China (English)

    YIN Jian-an; SHEN Xin-rong; CHEN Hua-jun; ZHANG Ben-zhao

    2004-01-01

    The effects of rotation and intermittent fre quency on the flow transition of secondary flow and, main flow were examined in detail. Certain hitherto unknown flow patterns were found. A numerical study was performed to study the characteristics of unsteady intermittent flow in a rotating curved pipe. Due to the rotation, both the Coriolis force and the centrifugal force could contribute to the unsteady intermittent flow and some complicated phenomena can be found. The results indicate that the unsteady intermittent flow are mainly characterized by five parameters: the Dean number Dn , the curvatureκ, the maximal force ratio F (of the Coriolis force to the centrifugal force in a cycle), the intermittent frequency parameter η(the ratio of a pulslating time to the cycle period), and the Womersley number α. Present works shows the natures of the unsteady intermittent flow in a rotating curved pipe.

  17. Risks of Serious Toxicities from Intermittent versus Continuous Androgen Deprivation Therapy for Advanced Prostate Cancer: A Population Based Study.

    Science.gov (United States)

    Tsai, Huei-Ting; Pfeiffer, Ruth M; Philips, George K; Barac, Ana; Fu, Alex Z; Penson, David F; Zhou, Yingjun; Potosky, Arnold L

    2017-05-01

    Randomized trials have shown that intermittent androgen deprivation therapy for patients with advanced prostate cancer may improve sexual and physical functioning compared to continuous androgen deprivation therapy without compromising survival. To our knowledge it is unknown whether intermittent androgen deprivation therapy alters the risk of serious toxicities associated with continuous androgen deprivation therapy. We performed a population based cohort study of 9,772 men 66 years old or older who were diagnosed with advanced prostate cancer from 2002 to 2011 and treated with androgen deprivation therapy. Intermittent androgen deprivation therapy was defined as a single 90-day interval between 2 androgen deprivation therapy sessions during which patients visited their physicians or underwent prostate specific antigen testing. Outcomes included acute myocardial infarction, stroke, heart failure, type 2 diabetes and fracture. We used Cox proportional hazard models to estimate the HRs of the comparative risk of serious toxicities between intermittent and continuous androgen deprivation therapy. A total of 2,113 (22%), 769 (9%) and 899 men (9%) had a new cardiovascular event, diabetes or fracture, respectively, within 5 years of starting androgen deprivation therapy. Compared to the continuous androgen deprivation therapy group, the intermittent therapy group was at lower risk for serious cardiovascular events (HR 0.64, 95% CI 0.53-0.77), particularly in reducing the risk of heart failure (HR 0.62, 95% CI 0.49-0.78) and fracture (HR 0.52, 95% CI 0.38-0.70, each p deprivation therapy was associated with a lower risk of heart failure and fracture compared to continuous androgen deprivation therapy. This raises toxicity concerns for continuous relative to intermittent therapy and suggests that intermittent androgen deprivation therapy may represent a safer therapeutic choice in elderly men with advanced prostate cancer. Copyright © 2017 American Urological Association

  18. Intermittency in processing explains the diversity and shape of functional grazing responses.

    Science.gov (United States)

    Wirtz, Kai W

    2012-08-01

    Central to theoretical studies of trophic interactions is the formulation of the consumer response to varying food availability. Response functions, however, are only rarely derived in mechanistic ways. As a consequence, the uncertainty in the functional representation of feeding remains large, as, e.g., evident from the ongoing debate on the usage of Ivlev, or Holling type I, II, and III functions in aquatic ecosystem models. Here, I refer to the work of Sjöberg in Ecol Model 10:215-225 (1980) who proposed to apply elements of the queuing theory developed in operational research to plankton-plankton interactions. Within this frame, food item processing is subdivided into two major stages which may operate with variable synchronicity. Asynchronous phasing of the two stages enhances the probability of long total processing times. This phenomenon is here termed feeding intermittency. Intermittency is assumed to determine the functional form of grazing kinetics, for which a novel grazing function containing a "shape" parameter is derived. Using this function, I evaluate the hypotheses that intermittency is influenced by (1) patchiness in the prey field (e.g., related to turbulence), and (2) the ratio of actual prey size to optimal prey size. Evidence for the first hypothesis arises from explaining reported variations in clearance rates of Acartia tonsa under different turbulence regimes. Further model applications to ingestion data for rotifers, copepods, and ciliates support the view that an increasing food size enhances intermittency and, this way, affects functional grazing responses. In the application to ciliate grazing, a possible prey density effect appears, possibly due to an intermittent activation of a feeding sub-stage. Queueing theory offers mechanistic explanations for transitions between Holling I-, II-, and Ivlev-type grazing. In doing so for variable prey size ratios, it may also refine size-based ecosystem models which are increasingly emerging in

  19. Clinical investigation of surgery for intermittent exotropia

    Institute of Scientific and Technical Information of China (English)

    Chong-qing YANG; Ye SHEN; Yang-shun GU; Wei HAN

    2008-01-01

    Objective: To investigate the time and postoperative binocular vision of strabismus surgery for children with intermittent exotropia (X (T)). Methods: A retrospective investigation was conducted in 80 child patients with intermittent exotropia. Pre- and postoperative angles of deviation fixating at near (33cm) and distant targets (6m) were measured with the prolonged alternate cover testing. The binocular function was assessed with synoptophore. Twenty-one patients took the postoperative synoptophore exercise. Results: (1) A week after surgery, 96.2% of the 80 patients had binocular normotopia, while a year after surgery, 91.3% of the 80 patients had binocular normotopia; (2) Preoperatively, 58 patients had near stereoacuity, while postoperatively, 72 patients achieved near stereoacuity (P<0.05); (3) Preoperatively, 64 patients had Grade I for the synoptophore evaluation and postoperatively, 76 patients achieved Grade I. Meanwhile, 55 patients had Grade Ⅱpreoperatively and 72 achieved Grade Ⅱ postoperatively. For Grade Ⅲ, there were 49 patients preoperatively and 64 patients postoperatively (P<0.05); (4) Patients of 5~8 years old had a significantly better recovery rate of binocular vision than those of 9~18 years old (P<0.05); (5)Patients taking postoperative synoptophore exercise had a better binocular vision than those taking no exercise (P<0.05). Conclusions: (1) Strabismus surgery can help to preserve or restore the binocular vision for intermittent exotropia; (2) Receiving the surgery at young ages may develop better postoperative binocular vision; (3) The postoperative synoptophore exercise can help to restore the binocular vision.

  20. Hovering and intermittent flight in birds

    Energy Technology Data Exchange (ETDEWEB)

    Tobalske, Bret W, E-mail: bret.tobalske@mso.umt.ed [Field Research Station at Fort Missoula, Division of Biological Sciences, University of Montana, Missoula, MT 59812 (United States)

    2010-12-15

    Two styles of bird locomotion, hovering and intermittent flight, have great potential to inform future development of autonomous flying vehicles. Hummingbirds are the smallest flying vertebrates, and they are the only birds that can sustain hovering. Their ability to hover is due to their small size, high wingbeat frequency, relatively large margin of mass-specific power available for flight and a suite of anatomical features that include proportionally massive major flight muscles (pectoralis and supracoracoideus) and wing anatomy that enables them to leave their wings extended yet turned over (supinated) during upstroke so that they can generate lift to support their weight. Hummingbirds generate three times more lift during downstroke compared with upstroke, with the disparity due to wing twist during upstroke. Much like insects, hummingbirds exploit unsteady mechanisms during hovering including delayed stall during wing translation that is manifest as a leading-edge vortex (LEV) on the wing and rotational circulation at the end of each half stroke. Intermittent flight is common in small- and medium-sized birds and consists of pauses during which the wings are flexed (bound) or extended (glide). Flap-bounding appears to be an energy-saving style when flying relatively fast, with the production of lift by the body and tail critical to this saving. Flap-gliding is thought to be less costly than continuous flapping during flight at most speeds. Some species are known to shift from flap-gliding at slow speeds to flap-bounding at fast speeds, but there is an upper size limit for the ability to bound ({approx}0.3 kg) and small birds with rounded wings do not use intermittent glides.

  1. Acute intermittent porphyria in the puerperium

    Directory of Open Access Journals (Sweden)

    Sparić Radmila

    2010-01-01

    Full Text Available Introduction. Acute intermittent porphyria emerges as a result of partial defect of porphobilinogen deaminase and is manifested by repeated episodes of somatic, psychiatric and neurological disorders. The disease is conducted via the autosomaldominant gene of variable penetration, so most of the carriers never experience seizures. Timely making of diagnosis, screening of blood relatives of the patient and education of patients on avoidance of provoking factors are the key to adequate treatment. Case Outline. A 23-year-old patient having born the third child was hospitalized due to pains in the abdomen and convulsive seizures nine days after the vaginal delivery. At admittance, she suffered a generalized convulsive seizure of clonic-tonic type. The patient immediately underwent a complete clinical, laboratory, bacteriological and ultrasound examination. Bearing in mind the fact that the patient had several convulsive seizures even after the given neurological therapy, haem-arginate was introduced into therapy during four days. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The administration of haem-arginate led to the normalization of blood pressure, pulse and bowel function. The patient was treated by a team of doctors, in the intensive care ward, with the use of medicaments, which are allowed in the case of acute porphyria. Sixteen days after the admittance, with clean neurological status and gynaecological and ultra-sound findings, she was released for ambulatory treatment. Conclusion. The presented case exhibits the gravity of making a diagnosis of acute intermittent porphyria in puerperium and the necessity of multi-disciplinary approach in treating this disease. Acute intermittent porphyria should be considered in cases of ambiguous abdominal pain, as well as in patients having abdominal pains followed by neuro-psychiatric disorders.

  2. Intermittent Microwave Drying of Wheat (Triticum aestivum L.) Seeds

    OpenAIRE

    Yan Li; Tao Zhang; Chenglai Wu; Chunqing Zhang

    2014-01-01

    The purpose of present study was to characterize the intermittent microwave drying of wheat seeds. Results revealed that microwave on time percentage (MOTP) and initial moisture content were the main parameters which influenced the intermittent microwave drying rate and the germination capacity of dried seeds. Best intermittent microwave drying (power: 800 W; seed sample weight: 100 g, microwave on time in each cycle: 32 s) without significantly decreasing the germination rate was...

  3. Long term and transitional intermittent smokers: a longitudinal study.

    OpenAIRE

    Lindström, Martin; Isacsson, Sven-Olof

    2002-01-01

    Objective: To investigate differences in snuff consumption, sociodemographic and psychosocial characteristics between baseline intermittent smokers that had become daily smokers, stopped smoking or remained intermittent smokers at the one year follow up. Design/setting/participants/measurements: A population of 12 507 individuals interviewed at baseline in 1992-94 and at a one year follow up, aged 45-69 years, was investigated in a longitudinal study. The three groups of baseline intermittent...

  4. Intermittent fasting: a "new" historical strategy for controlling seizures?

    Science.gov (United States)

    Hartman, Adam L; Rubenstein, James E; Kossoff, Eric H

    2013-05-01

    In antiquity, fasting was a treatment for epilepsy and a rationale for the ketogenic diet (KD). Preclinical data indicate the KD and intermittent fasting do not share identical anticonvulsant mechanisms. We implemented an intermittent fasting regimen in six children with an incomplete response to a KD. Three patients adhered to the combined intermittent fasting/KD regimen for 2 months and four had transient improvement in seizure control, albeit with some hunger-related adverse reactions.

  5. Vancomycin-associated nephrotoxicity: A meta-analysis of administration by continuous versus intermittent infusion.

    Science.gov (United States)

    Hanrahan, Timothy; Whitehouse, Tony; Lipman, Jeffrey; Roberts, Jason A

    2015-09-01

    Vancomycin is a glycopeptide antibiotic widely used in the management of meticillin-resistant Staphylococcus aureus (MRSA). Guidelines currently recommend vancomycin be administered by intermittent infusion, despite recent research suggesting that continuous infusion (CI) may be associated with lower rates of vancomycin-associated nephrotoxicity. In 2012, Cataldo et al. presented a meta-analysis supporting the use of CI. Here we present an updated meta-analysis, inclusive of a recently published large-scale retrospective study. PubMed, EMBASE and Cochrane Reviews databases were searched using the keywords 'vancomycin' and 'continuous' or 'intermittent' or 'infusion' or 'discontinuous' or 'administration'. Seven studies were included in the final analysis. Using a random-effects model, a non-significant trend of reduced nephrotoxicity in those who received vancomycin by CI (risk ratio=0.799, 95% confidence interval 0.523-1.220; P=0.299) was identified. A large, randomised controlled trial is necessary to confirm these results.

  6. Impact of syllable stress and phonetic vowel context on the distribution of intermittent aphonia

    DEFF Research Database (Denmark)

    Iwarsson, Jenny; Fredsø, Julie

    2014-01-01

    with intermittent aphonia are not totally randomly appearing, but related to syllable stress and phonetic context. Recordings of 31 dysphonic patients with intermittent aphonia reading a standard text were analyzed perceptually. All vowels of the text were labelled and categorized with regard to syllable stress...... and character of the phoneme preceding the vowel. The occurrence of aphonic instances within each syllable category was analyzed. Four different hypotheses were formulated and analyzed by the non-parametric Wilcoxon’s signedranks test. The results showed a significantly higher occurrence of aphonic instances...... in unstressed syllables as opposed to stressed, in vowels following an unvoiced phoneme as opposed to a voiced, and in vowels following two or more unvoiced phonemes as opposed to one unvoiced phoneme. No significant difference was found between vowels following aspirated stops [p], [t], [k] as opposed...

  7. Probabilistic description of extreme events in intermittently unstable systems excited by correlated stochastic processes

    CERN Document Server

    Mohamad, Mustafa A

    2015-01-01

    In this work, we consider systems that are subjected to intermittent instabilities due to external stochastic excitation. These intermittent instabilities, though rare, have a large impact on the probabilistic response of the system and give rise to heavy-tailed probability distributions. By making appropriate assumptions on the form of these instabilities, which are valid for a broad range of systems, we formulate a method for the analytical approximation of the probability distribution function (pdf) of the system response (both the main probability mass and the heavy-tail structure). In particular, this method relies on conditioning the probability density of the response on the occurrence of an instability and the separate analysis of the two states of the system, the unstable and stable state. In the stable regime we employ steady state assumptions, which lead to the derivation of the conditional response pdf using standard methods for random dynamical systems. The unstable regime is inherently transient...

  8. Intermittent oral iron supplementation during pregnancy (Review)

    Science.gov (United States)

    Peña-Rosas, Juan Pablo; De-Regil, Luz Maria; Dowswell, Therese; Viteri, Fernando E

    2014-01-01

    Background Anaemia is a frequent condition during pregnancy, particularly among women from developing countries who have insufficient iron intake to meet increased iron needs of both the mother and the fetus. Traditionally, gestational anaemia has been prevented with the provision of daily iron supplements throughout pregnancy, but adherence to this regimen due to side effects, interrupted supply of the supplements, and concerns about safety among women with an adequate iron intake, have limited the use of this intervention. Intermittent (i.e. one, two or three times a week on non-consecutive days) supplementation with iron alone or in combination with folic acid or other vitamins and minerals has recently been proposed as an alternative to daily supplementation. Objectives To assess the benefits and harms of intermittent supplementation with iron alone or in combination with folic acid or other vitamins and minerals to pregnant women on neonatal and pregnancy outcomes. Search methods We searched the Cochrane Pregnancy and Childbirth Group’s Trials Register (23 March 2012). We also searched the WHO International Clinical Trials Registry Platform (ICTRP) for ongoing studies and contacted relevant organisations for the identification of ongoing and unpublished studies (23 March 2012). Selection criteria Randomised or quasi-randomised trials. Data collection and analysis We assessed the methodological quality of trials using standard Cochrane criteria. Two review authors independently assessed trial eligibility, extracted data and conducted checks for accuracy. Main results This review includes 21 trials from 13 different countries, but only 18 trials (with 4072 women) reported on our outcomes of interest and contributed data to the review. All of these studies compared daily versus intermittent iron supplementation. Three studies provided iron alone, 12 iron+folic acid and three more iron plus multiple vitamins and minerals. Their methodological quality was mixed

  9. [Acute intermittent porphyria and inappropriate ADH syndrome].

    Science.gov (United States)

    Tébar, M T; Aguilera, L

    2010-05-01

    A 44-year-old woman complained of abdominal pain of 4 days' duration accompanied by vomiting and painful urination. The admitting physician noted neurologic signs consistent with axonal polyneuropathy and hyponatremia. In the absence of other explanations for the syndrome, SIADH was diagnosed. Because of the nonspecific nature of the observations, the patient was assessed by various specialists and admitted to the anesthetic recovery unit due to worsening of neurologic signs and suspicion of acute intermittent porphyria. The diagnosis was confirmed by laboratory findings of elevated d-aminolevulinic acid and porphobilinogen levels and normal stool porphyrins. The patient improved with intravenous hematin infused over 4 days.

  10. Intermittent Atrioventricular Block following Fingolimod Initiation

    Directory of Open Access Journals (Sweden)

    E. Gialafos

    2014-01-01

    Full Text Available A 47-year-old female patient with multiple sclerosis (MS developed symptomatic intermittent 2nd degree atrioventricular block (AVB of five-hour duration, five hours after the first two doses of fingolimod, that resolved completely. Frequency domain analysis of heart rate variability (HRV revealed increased parasympathetic activity and decreased sympathetic tone, while modified Ewing tests were suggestive of impaired cardiac sympathetic function. We hypothesize that expression of this particular arrhythmia might be related to autonomic nervous system (ANS dysfunction due to demyelinating lesions in the upper thoracic spinal cord, possibly augmented by the parasympathetic effect of the drug.

  11. Muscle coordination changes during intermittent cycling sprints.

    Science.gov (United States)

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-03

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, Pcycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue.

  12. Transition to turbulence, intermittence, and vortex fluctuations

    Energy Technology Data Exchange (ETDEWEB)

    Bershadskii, A.G.

    1985-09-01

    A model is developed which describes the fluctuation coalescence of vortices at moderately high Reynolds numbers. The model is found to be in good agreement with experimental data on (1) flow intermittence in a boundary layer, a round jet, and a plane wake; (2) the effect of a magnetic field on the formation of a turbulent energy spectrum behind a grid and on turbulent fluctuations and friction in ducts; (3) formation of a turbulent energy spectrum in a boundary layer and in ducts. 12 references.

  13. Diagnosing Intermittent and Persistent Faults using Static Bayesian Networks

    Science.gov (United States)

    Megshoel, Ole Jakob

    2010-01-01

    Both intermittent and persistent faults may occur in a wide range of systems. We present in this paper the introduction of intermittent fault handling techniques into ProDiagnose, an algorithm that previously only handled persistent faults. We discuss novel algorithmic techniques as well as how our static Bayesian networks help diagnose, in an integrated manner, a range of intermittent and persistent faults. Through experiments with data from the ADAPT electrical power system test bed, generated as part of the Second International Diagnostic Competition (DXC-10), we show that this novel variant of ProDiagnose diagnoses intermittent faults accurately and quickly, while maintaining strong performance on persistent faults.

  14. Control of on-off intermittency by slow parametric modulation.

    Science.gov (United States)

    Reategui, Rider Jaimes; Pisarchik, Alexander N

    2004-06-01

    We study on-off intermittent behavior in two coupled double-well Duffing oscillators with stochastic driving and demonstrate that, by using slow harmonic modulation applied to an accessible system parameter, the intermittent attractors can be completely eliminated. The influence of noise is also investigated. Power-law scaling of the average laminar time with a critical exponent of -1 as a function of both the amplitude and frequency of the control modulation is found near the onset of intermittency, which is a signature of on-off intermittency.

  15. Intermittent lag synchronization in a driven system of coupled oscillators

    Indian Academy of Sciences (India)

    Alexander N Pisarchik; Rider Jaimes-Reátegui

    2005-04-01

    We study intermittent lag synchronization in a system of two identical mutually coupled Duffing oscillators with parametric modulation in one of them. This phenomenon in a periodically forced system can be seen as intermittent jump from phase to lag synchronization, during which the chaotic trajectory visits a periodic orbit closely. We demonstrate different types of intermittent lag synchronizations, that occur in the vicinity of saddle-node bifurcations where the system changes its dynamical state, and characterize the simplest case of period-one intermittent lag synchronization.

  16. Adaptive intermittent control: A computational model explaining motor intermittency observed in human behavior.

    Science.gov (United States)

    Sakaguchi, Yutaka; Tanaka, Masato; Inoue, Yasuyuki

    2015-07-01

    It is a fundamental question how our brain performs a given motor task in a real-time fashion with the slow sensorimotor system. Computational theory proposed an influential idea of feed-forward control, but it has mainly treated the case that the movement is ballistic (such as reaching) because the motor commands should be calculated in advance of movement execution. As a possible mechanism for operating feed-forward control in continuous motor tasks (such as target tracking), we propose a control model called "adaptive intermittent control" or "segmented control," that brain adaptively divides the continuous time axis into discrete segments and executes feed-forward control in each segment. The idea of intermittent control has been proposed in the fields of control theory, biological modeling and nonlinear dynamical system. Compared with these previous models, the key of the proposed model is that the system speculatively determines the segmentation based on the future prediction and its uncertainty. The result of computer simulation showed that the proposed model realized faithful visuo-manual tracking with realistic sensorimotor delays and with less computational costs (i.e., with fewer number of segments). Furthermore, it replicated "motor intermittency", that is, intermittent discontinuities commonly observed in human movement trajectories. We discuss that the temporally segmented control is an inevitable strategy for brain which has to achieve a given task with small computational (or cognitive) cost, using a slow control system in an uncertain variable environment, and the motor intermittency is the side-effect of this strategy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Childhood trauma predicts antidepressant response in adults with major depression: data from the randomized international study to predict optimized treatment for depression.

    Science.gov (United States)

    Williams, L M; Debattista, C; Duchemin, A-M; Schatzberg, A F; Nemeroff, C B

    2016-05-03

    Few reliable predictors indicate which depressed individuals respond to antidepressants. Several studies suggest that a history of early-life trauma predicts poorer response to antidepressant therapy but results are variable and limited in adults. The major goal of the present study was to evaluate the role of early-life trauma in predicting acute response outcomes to antidepressants in a large sample of well-characterized patients with major depressive disorder (MDD). The international Study to Predict Optimized Treatment for Depression (iSPOT-D) is a randomized clinical trial with enrollment from December 2008 to January 2012 at eight academic and nine private clinical settings in five countries. Patients (n=1008) meeting DSM-IV criteria for MDD and 336 matched healthy controls comprised the study sample. Six participants withdrew due to serious adverse events. Randomization was to 8 weeks of treatment with escitalopram, sertraline or venlafaxine with dosage adjusted by the participant's treating clinician per routine clinical practice. Exposure to 18 types of traumatic events before the age of 18 was assessed using the Early-Life Stress Questionnaire. Impact of early-life stressors-overall trauma 'load' and specific type of abuse-on treatment outcomes measures: response: (⩾50% improvement on the 17-item Hamilton Rating Scale for Depression, HRSD17 or on the 16-item Quick Inventory of Depressive Symptomatology-Self-Rated, QIDS_SR16) and remission (score ⩽7 on the HRSD17 and ⩽5 on the QIDS_SR16). Trauma prevalence in MDD was compared with controls. Depressed participants were significantly more likely to report early-life stress than controls; 62.5% of MDD participants reported more than two traumatic events compared with 28.4% of controls. The higher rate of early-life trauma was most apparent for experiences of interpersonal violation (emotional, sexual and physical abuses). Abuse and notably abuse occurring at ⩽7 years of age predicted poorer outcomes

  18. Influence of Dehydration on Intermittent Sprint Performance.

    Science.gov (United States)

    Davis, Jon-Kyle; Laurent, C Matt; Allen, Kimberly E; Green, J Matt; Stolworthy, Nicola I; Welch, Taylor R; Nevett, Michael E

    2015-09-01

    This study examined the effects of dehydration on intermittent sprint performance and perceptual responses. Eight male collegiate baseball players completed intermittent sprints either dehydrated (DEHY) by 3% body mass or euhydrated (EU). Body mass was reduced through exercise in the heat with controlled fluid restriction occurring 1 day before the trial. Participants completed twenty-four 30-m sprints divided into 3 bouts of 8 sprints with 45 seconds of rest between each sprint and 3 minutes between each bout. Perceived recovery status (PRS) scale was recorded before the start of each trial. Heart rate (HR), ratings of perceived exertion (RPE) (0-10 OMNI scale), and perceived readiness (PR) scale were recorded after every sprint, and session RPE (SRPE) was recorded 20 minutes after completing the entire session. A 2 (condition) × 3 (bout of sprints) repeated-measures ANOVA revealed a significant main effect of condition on mean sprint time (p = 0.03), HR (p Dehydration impaired sprint performance, negatively altered perception of recovery status before exercise, and increased RPE and HR response.

  19. Intermittent heat instabilities in an air plume

    Science.gov (United States)

    Le Mouël, Jean-Louis; Kossobokov, Vladimir G.; Perrier, Frederic; Morat, Pierre

    2016-08-01

    We report the results of heating experiments carried out in an abandoned limestone quarry close to Paris, in an isolated room of a volume of about 400 m3. A heat source made of a metallic resistor of power 100 W was installed on the floor of the room, at distance from the walls. High-quality temperature sensors, with a response time of 20 s, were fixed on a 2 m long bar. In a series of 24 h heating experiments the bar had been set up horizontally at different heights or vertically along the axis of the plume to record changes in temperature distribution with a sampling time varying from 20 to 120 s. When taken in averages over 24 h, the temperatures present the classical shape of steady-state plumes, as described by classical models. On the contrary, the temperature time series show a rich dynamic plume flow with intermittent trains of oscillations, spatially coherent, of large amplitude and a period around 400 s, separated by intervals of relative quiescence whose duration can reach several hours. To our knowledge, no specific theory is available to explain this behavior, which appears to be a chaotic interaction between a turbulent plume and a stratified environment. The observed behavior, with first-order factorization of a smooth spatial function with a global temporal intermittent function, could be a universal feature of some turbulent plumes in geophysical environments.

  20. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Directory of Open Access Journals (Sweden)

    Lindsay B. Baker

    2015-07-01

    Full Text Available Intermittent sports (e.g., team sports are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h. Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1 potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2 the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3 what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports. Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before

  1. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance

    Science.gov (United States)

    Baker, Lindsay B.; Rollo, Ian; Stein, Kimberly W.; Jeukendrup, Asker E.

    2015-01-01

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1–2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30–60 g/h in the form of a 6%–7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a

  2. Acute Effects of Carbohydrate Supplementation on Intermittent Sports Performance.

    Science.gov (United States)

    Baker, Lindsay B; Rollo, Ian; Stein, Kimberly W; Jeukendrup, Asker E

    2015-07-14

    Intermittent sports (e.g., team sports) are diverse in their rules and regulations but similar in the pattern of play; that is, intermittent high-intensity movements and the execution of sport-specific skills over a prolonged period of time (~1-2 h). Performance during intermittent sports is dependent upon a combination of anaerobic and aerobic energy systems, both of which rely on muscle glycogen and/or blood glucose as an important substrate for energy production. The aims of this paper are to review: (1) potential biological mechanisms by which carbohydrate may impact intermittent sport performance; (2) the acute effects of carbohydrate ingestion on intermittent sport performance, including intermittent high-intensity exercise capacity, sprinting, jumping, skill, change of direction speed, and cognition; and (3) what recommendations can be derived for carbohydrate intake before/during exercise in intermittent sports based on the available evidence. The most researched intermittent sport is soccer but some sport-specific studies have also been conducted in other sports (e.g., rugby, field hockey, basketball, American football, and racquet sports). Carbohydrate ingestion before/during exercise has been shown in most studies to enhance intermittent high-intensity exercise capacity. However, studies have shown mixed results with regards to the acute effects of carbohydrate intake on sprinting, jumping, skill, change of direction speed, and cognition. In most of these studies the amount of carbohydrate consumed was ~30-60 g/h in the form of a 6%-7% carbohydrate solution comprised of sucrose, glucose, and/or maltodextrin. The magnitude of the impact that carbohydrate ingestion has on intermittent sport performance is likely dependent on the carbohydrate status of the individual; that is, carbohydrate ingestion has the greatest impact on performance under circumstances eliciting fatigue and/or hypoglycemia. Accordingly, carbohydrate ingestion before and during a game

  3. Computer-assisted resilience training to prepare healthcare workers for pandemic influenza: a randomized trial of the optimal dose of training

    Directory of Open Access Journals (Sweden)

    Vincent Leslie

    2010-03-01

    Full Text Available Abstract Background Working in a hospital during an extraordinary infectious disease outbreak can cause significant stress and contribute to healthcare workers choosing to reduce patient contact. Psychological training of healthcare workers prior to an influenza pandemic may reduce stress-related absenteeism, however, established training methods that change behavior and attitudes are too resource-intensive for widespread use. This study tests the feasibility and effectiveness of a less expensive alternative - an interactive, computer-assisted training course designed to build resilience to the stresses of working during a pandemic. Methods A "dose-finding" study compared pre-post changes in three different durations of training. We measured variables that are likely to mediate stress-responses in a pandemic before and after training: confidence in support and training, pandemic-related self-efficacy, coping style and interpersonal problems. Results 158 hospital workers took the course and were randomly assigned to the short (7 sessions, median cumulative duration 111 minutes, medium (12 sessions, 158 minutes or long (17 sessions, 223 minutes version. Using an intention-to-treat analysis, the course was associated with significant improvements in confidence in support and training, pandemic self-efficacy and interpersonal problems. Participants who under-utilized coping via problem-solving or seeking support or over-utilized escape-avoidance experienced improved coping. Comparison of doses showed improved interpersonal problems in the medium and long course but not in the short course. There was a trend towards higher drop-out rates with longer duration of training. Conclusions Computer-assisted resilience training in healthcare workers appears to be of significant benefit and merits further study under pandemic conditions. Comparing three "doses" of the course suggested that the medium course was optimal.

  4. Optimizing Rehabilitation for Phantom Limb Pain Using Mirror Therapy and Transcranial Direct Current Stimulation: A Randomized, Double-Blind Clinical Trial Study Protocol.

    Science.gov (United States)

    Pinto, Camila Bonin; Saleh Velez, Faddi Ghassan; Bolognini, Nadia; Crandell, David; Merabet, Lotfi B; Fregni, Felipe

    2016-07-06

    intervention. This clinical trial received institutional review board (IRB) approval in July of 2015 and enrollment started in December of 2015. To date 2 participants have been enrolled. The estimate enrollment rate is about 30 to 35 patients per year; thus we expect to complete enrollment in 4 years. This factorial design will provide relevant data to evaluate whether tDCS combined with MT is more effective than each therapy alone, as well as with no intervention (sham/sham) in patients with chronic PLP after unilateral lower limb amputation. In addition, this randomized clinical trial will help to investigate the neurophysiological mechanisms underlying the disease, which could potentially provide relevant findings for further management of this chronic condition and also help to optimize the use of this novel intervention. Clinicaltrials.gov NCT02487966; https://clinicaltrials.gov/ct2/show/NCT02487966 (Archived by WebCite at http://www.webcitation.org/6i3GrKMyf).

  5. Reactive power optimization of distribution network considering PV station random output%计及光伏电站随机出力的配电网无功优化

    Institute of Scientific and Technical Information of China (English)

    郭康; 徐玉琴; 张丽; 岳建房; 孙利芳

    2012-01-01

    This paper considers reactive power of PV station as reactive power optimization control variables, and discusses the reactive power optimization problem in distribution power system with photovoltaic power station. Due to the randomness output of photovoltaic power station, the voltage of distribution network with photovoltaic power station distribution also shows randomness, as a result, the constraint of the determined voltage in traditional reactive power optimization model is inaccurate. For the randomness of the output of PV power plant, we use random flow algorithm to obtain the probability distribution of each node voltage, put chance constraints on the voltage, take the minimum of power loss as the objective function and then build mathematical model of reactive power optimization for distribution network connected with PV power plant. Using the above reactive power optimization mathematical model based on random constraints, we optimize an example by using the stardard particle swarm algorithm. The optimization results verify the accuracy and the effectiveness of the model and algorithm.%将光伏电站的无功功率作为无功优化的控制变量,研究了含光伏电站配电网无功优化问题.由于光伏电站出力的随机性,使得含光伏电站配电网各节点的电压也具有随机性,所以传统无功优化模型中对确定电压的约束已不精确.在此采用随机潮流算法,求得各节点电压的概率分布,对电压进行机会约束,以有功损耗期望值最小为目标函数,建立了含光伏电站配电网的无功优化数学模型.运用上述基于随机约束的无功优化数学模型,采用标准的粒子群算法对算例进行优化,优化结果验证了该模型与算法的准确性与有效性.

  6. Bound by Children: Intermittent Cohabitation and Living Together Apart

    Science.gov (United States)

    Cross-Barnet, Caitlin; Cherlin, Andrew; Burton, Linda

    2011-01-01

    In this article, we examine variations in low-income mothers' patterns of intermittent cohabitation and the voluntary and involuntary nature of these unions. Intermittent cohabitation involves couples living together and separating in repeating cycles. Using Three-City Study ethnographic data, we identified 45 low-income mothers involved in these…

  7. Intermittent Turbulence in Stratified Flow over a Canopy

    NARCIS (Netherlands)

    Boing, S.; Jonker, H.J.J.; Wiel, van de B.J.H.; Moene, A.F.

    2010-01-01

    During the night turbulence can often be very intermittent, occurring in sudden vigorous bursts after prolonged periods of low-intensity. Several mechanisms have been proposed to explain intermittency. The present study focuses on the role of porous surface elements, which influence the mean wind

  8. Environmental heat stress, hyperammonemia and nucleotide metabolism during intermittent exercise

    DEFF Research Database (Denmark)

    Mohr, Magni; Rasmussen, Peter; Drust, Barry

    2006-01-01

    Abstract  This study investigated the influence of environmental heat stress on ammonia (NH3) accumulation in relation to nucleotide metabolism and fatigue during intermittent exercise. Eight males performed 40 min of intermittent exercise (15 s at 306±22 W alternating with 15 s of unloaded cycli...

  9. Intermittent versus Continuous Physiotherapy in Children with Cerebral Palsy

    Science.gov (United States)

    Christiansen, Annette Sandahl; Lange, Christa

    2008-01-01

    The aim of this study was to compare the effect of the delivery of the same amount of intermittent versus continuous physiotherapy given to children with cerebral palsy (CP). This was organized either in an intermittent regime four times a week for 4 weeks alternating with a 6-week treatment pause, or a continuous once or twice a week regime, both…

  10. 21 CFR 868.5955 - Intermittent mandatory ventilation attachment.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Intermittent mandatory ventilation attachment. 868.5955 Section 868.5955 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... mandatory ventilation attachment. (a) Identification. An intermittent mandatory ventilation (IMV)...

  11. Stochastic optimization methods

    CERN Document Server

    Marti, Kurt

    2008-01-01

    Optimization problems arising in practice involve random model parameters. This book features many illustrations, several examples, and applications to concrete problems from engineering and operations research.

  12. Intermittent Oral Versus Intravenous Alfacalcidol in Dialysis Patients

    Directory of Open Access Journals (Sweden)

    Mitwalli Ahmed

    2000-01-01

    Full Text Available Patients with end-stage renal failure (ESRF on maintenance dialysis, commonly develop secondary hyperparathyroidism and renal osteodystrophy (ROD. Alfacalcidol, taken orally or administered intravenously, is known to reverse these complications. In this study, 19 ESRF patients, who were on dialysis (13 on hemodialysis and six on peritoneal dialysis for longer than six months and having serum parathormone levels at least four times normal and serum calcium less than 2.1 mmol/L, were randomly allocated to treatment with oral or intravenous (i.v. alfacalcidol for a period of 12 months. There were six patients on hemodialysis (HD and three on peritoneal dialysis (PD in the oral treatment group while in the i.v. group there were seven patients on HD and three on PD. Clinical and serial biochemical assessments showed no statistically significant difference between the orally- and i.v.-treated patients in terms of suppressing secondary hyperparathyroidism and osteodystrophy. However, patients with features of mild ROD on bone histology, had more satisfactory changes in biochemistry when compared to others. Our results further support the use of intermittent oral alfacalcidol in ESRF patients because of its cost effectiveness, ease of administration and convenience, especially for peritoneal dialysis patients.

  13. Intermittent Behavior and Synchronization of Two Coupled Noisy Driven Oscillators

    Directory of Open Access Journals (Sweden)

    Ângela Maria dos Santos

    2009-01-01

    Full Text Available The coupled system of two forced Liénard-type oscillators has applications in diode-based electric circuits and phenomenological models for the heartbeat. These systems typically exhibit intermittent transitions between laminar and chaotic states; what affects their performance and, since noise is always present in such systems, dynamical models should include these effects. Accordingly, we investigated numerically the effect of noise in two intermittent phenomena: the intermittent transition to synchronized behavior for identical and unidirectionally coupled oscillators, and the intermittent transition to chaos near a periodic window of bidirectionally coupled oscillators. We found that the transition from a nonsynchronized to a synchronized state exhibits a power-law scaling with exponent 3/2 characterizing on-off intermittency. The inclusion of noise adds an exponential tail to this scaling.

  14. Magnetic Reconnection and Intermittent Turbulence in the Solar Wind

    CERN Document Server

    Osman, K T; Gosling, J T; Greco, A; Servidio, S; Hnat, B; Chapman, S C; Phan, T D

    2014-01-01

    A statistical relationship between magnetic reconnection, current sheets and intermittent turbulence in the solar wind is reported for the first time using in-situ measurements from the Wind spacecraft at 1 AU. We identify intermittency as non-Gaussian fluctuations in increments of the magnetic field vector, $\\mathbf{B}$, that are spatially and temporally non-uniform. The reconnection events and current sheets are found to be concentrated in intervals of intermittent turbulence, identified using the partial variance of increments method: within the most non-Gaussian 1% of fluctuations in $\\mathbf{B}$, we find 87%-92% of reconnection exhausts and $\\sim$9% of current sheets. Also, the likelihood that an identified current sheet will also correspond to a reconnection exhaust increases dramatically as the least intermittent fluctuations are removed from the dataset. Hence, the turbulent solar wind contains a hierarchy of intermittent magnetic field structures that are increasingly linked to current sheets, which ...

  15. Intermittent drying of beans in a spouted bed

    Directory of Open Access Journals (Sweden)

    C. A. Oliveira

    2007-12-01

    Full Text Available Carioca beans are a highly nutritious grain, in terms of the amount of protein, iron and potassium as well as carbohydrates and fiber and as a source of vitamins. The moisture content of recently picked beans is too high for good preservation and storage, resulting in the need for drying before packaging. In this work, the drying of Carioca beans in a laboratory scale spouted bed under intermittent conditions of the drying air was experimentally analyzed. Experiments carried out consisted of two types of intermittent regime: intermittence in the spout regime, referred to as spouted/fixed bed and intermittence of the air supply to the bed, called spouted bed/rest. The results were compared to those for bean drying in a spouted bed dryer without intermittence.

  16. Scintillation-Induced Intermittency in SETI

    CERN Document Server

    Cordes, J M; Sagan, Carl Edward; Cordes, James M.; Sagan, Carl

    1997-01-01

    We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant sources (> 100 pc), while making redetections improbable. We consider three models in order to assess the non-repeating, narrowband events found in recent SETI and to analyze large surveys in general: (I) Radiometer noise; (II) A population of constant Galactic sources undergoing interstellar scintillation,; and (III) Real, transient signals (or hardware errors) of either terrestrial or ET origin. We apply likelihood and Bayesian tests of the models to The Planetary Society/Harvard META data. We find that Models II and III are both highly preferred to Model I, but that Models II and III are about equally likely. Ruling out Model II in favor of Model III requires many more reobservations than were conducted in META *or* the reobservation threshold must be much lower than wa...

  17. [Intermittent compression of the subclavian vein].

    Science.gov (United States)

    Maraval, M

    1980-01-01

    The pathology of the cervico-thoracic channel is now well understood. Intermittent venous compression in the costo-clavicular space by the subclavian muscle can lead to acute occlusion of the venous trunk. It is important to make an early diagnosis of such compression before the stage of occlusive phlebitis. Clinical examination and dynamic phlebography allow the diagnosis to be made. Resection of the first rib is the ideal treatment. The mode of approach to the first rib is debatable since it seems that when venous symptomatology is dominant, the axillary method of Roos is not the best approach. A combined sub- and supra-clavicular approach permits a wide decompression of the vein and a more complete excision of the rib.

  18. Scale Dependence of Spatiotemporal Intermittence of Rain

    Science.gov (United States)

    Kundu, Prasun K.; Siddani, Ravi K.

    2011-01-01

    It is a common experience that rainfall is intermittent in space and time. This is reflected by the fact that the statistics of area- and/or time-averaged rain rate is described by a mixed distribution with a nonzero probability of having a sharp value zero. In this paper we have explored the dependence of the probability of zero rain on the averaging space and time scales in large multiyear data sets based on radar and rain gauge observations. A stretched exponential fannula fits the observed scale dependence of the zero-rain probability. The proposed formula makes it apparent that the space-time support of the rain field is not quite a set of measure zero as is sometimes supposed. We also give an ex.planation of the observed behavior in tenus of a simple probabilistic model based on the premise that rainfall process has an intrinsic memory.

  19. Turbulent flows and intermittency in laboratory experiments

    Science.gov (United States)

    Anselmet, F.; Antonia, R. A.; Danaila, L.

    2001-10-01

    In turbulent flows, the transfer of energy from large to small scales is strongly intermittent, in contradiction with Kolmogorov's (Dokl. Akad. Nauk. SSSR 30 (1941) 299; hereafter K41) assumptions. The statistical properties associated with these energy transfer fluctuations at a given scale r have been widely studied theoretically, experimentally and numerically over the last 30 years or so. Such fluctuations are also encountered in various Planetary and Space Science domains. The present paper presents a review of laboratory experiments which clearly display the fractal nature of the (spatial or temporal) energy distribution at scale r, the departures from the K41 predictions being generally quantified through high-order moments of velocity increments.

  20. Population dynamics in an intermittent refuge

    Science.gov (United States)

    Colombo, E. H.; Anteneodo, C.

    2016-10-01

    Population dynamics is constrained by the environment, which needs to obey certain conditions to support population growth. We consider a standard model for the evolution of a single species population density, which includes reproduction, competition for resources, and spatial spreading, while subject to an external harmful effect. The habitat is spatially heterogeneous, there existing a refuge where the population can be protected. Temporal variability is introduced by the intermittent character of the refuge. This scenario can apply to a wide range of situations, from a laboratory setting where bacteria can be protected by a blinking mask from ultraviolet radiation, to large-scale ecosystems, like a marine reserve where there can be seasonal fishing prohibitions. Using analytical and numerical tools, we investigate the asymptotic behavior of the total population as a function of the size and characteristic time scales of the refuge. We obtain expressions for the minimal size required for population survival, in the slow and fast time scale limits.

  1. Clinical relevance of intermittent tumour blood flow

    Energy Technology Data Exchange (ETDEWEB)

    Durand, Ralph E.; Aquino-Parsons, Christina [British Columbia Cancer Research Centre, Vancouver (Canada)

    2001-12-01

    One of the goals of translational cancer research is to understand basic 'phenomena' so that tumour response to therapy can be improved. One such phenomenon is intermittent tumour blood flow. The impact of the transient hypoxia that results from decreased tumour blood flow is now beginning to be appreciated in preclinical systems, and also receiving some attention in clinical practise. Thus in this article we review the nature and frequency of microregional blood flow changes in preclinical and clinical tumours and examine the impact of those changes on response to both radiotherapy and chemotherapy. Additionally, the implications of non-constant blood flow for both the growth of the unperturbed tumour and the regrowth of surviving tumour clonogens during and after therapy are examined.

  2. [Intermittent Explosive Disorder: A Controversial Diagnosis].

    Science.gov (United States)

    Zapata, Juan Pablo; Palacio, Juan David

    2016-01-01

    Intermittent explosive disorder (IED) is aan externalizing externalising disorder characterized characterised by recurrent aggression episodes. Even though this disorder was described several decades ago, and it carries personal and social consequences, there is little in the medical scientific literature on this. bibliographic production about it is scanty. To perform a conceptualization conceptualisation of this disorder, through the review and bibliometric analysis of the available scientific articles. A search was performed in databases with the english English terms intermittent explosive disorder, impulse disorders control [MeSH], in combination with other terms. A bibliometric analysis in the GoPubMed® search engineer was also performed using all data obtained in the search. was also perfomed. IED prevalence ranges from 1.4% to 7%, it presents more frequently during middle adolescence, and with more noticeable repercussions in men males than in womenfemales. The psychopathological core of IED is the impulsive aggressive behaviour that presents in the form of «attacks» that occurs in response to a lower precipitating stimulus. Scientific publications about IED are few and relatively recent, and the vast majority is provided bycomes from the United States (56.56%), and headed by a single author. This fact highlights the need to replicate the findings described about the IED in order to demonstrate the validity and reliability of its diagnostic criteria. It is possible that doubts about the existence of a diagnosis lead have led to such a scant literature about the IED. Available studies about IED allow have allowed characterizing a group of subjects with episodes of impulsive aggression to be characterised, but this description requires replication in different latitudesneeds to be repeated in different areas. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  3. Treatment of febrile seizures with intermittent clobazam.

    Science.gov (United States)

    Manreza, M L; Gherpelli, J L; Machado-Haertel, L R; Pedreira, C C; Heise, C O; Diament, A

    1997-12-01

    Fifty children, 24 female and 26 male, with ages varying from 6 to 72 months (mean = 23.7 m.) that experienced at least one febrile seizure (FS) entered a prospective study of intermittent therapy with clobazam. Cases with severe neurological abnormalities, progressive neurological disease, afebrile seizures, symptomatic seizures of other nature, or seizures during a central nervous system infection were excluded. Seizures were of the simple type in 25 patients, complex in 20 and unclassified in 5. The mean follow-up period was 7.9 months (range = 1 to 23 m.), and the age at the first seizure varied from 5 to 42 months (mean = 16.8 m.). Clobazam was administered orally during the febrile episode according to the child's weight: up to 5 kg, 5 mg/day; from 5 to 10 kg, 10 mg/day; from 11 to 15 kg, 15 mg/day, and over 15 kg, 20 mg/day. There were 219 febrile episodes, with temperature above 37.8 degrees C, in 40 children during the study period. Twelve children never received clobazam and 28 received the drug at least once. Drug efficacy was measured by comparing FS recurrence in the febrile episodes that were treated with clobazam with those in which only antipyretic measures were taken. Ten children (20%) experienced a FS during the study period. Of the 171 febrile episodes treated with clobazam there were only 3 recurrences (1.7%), while of the 48 episodes treated only with antipyretic measures there were 11 recurrences (22.9%), a difference highly significant (p diazepam in the intermittent treatment of FS recurrence.

  4. Commercial and Industrial Base Intermittent Resource Management Pilot

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila; Sporborg, Pamela; Sheik, Imran; Huffaker, Erich; Piette, Mary Ann

    2010-11-30

    This scoping study summarizes the challenges with integrating wind and solar generation into the California's electricity grid. These challenges include: Smoothing intra-hour variability; - Absorbing excess renewable energy during over-generation periods; - Addressing morning and evening ramping periods. In addition, there are technical challenges to integrating retail demand response (DR) triggered by the wholesale conditions into the CAISO markets. The study describes the DR programs available to the consumers through the utilities in California and CAISO's ancillary services market because an integration of the wholesale and retail DR requires an understanding of these different offerings and the costs associated with acquiring them. Demand-side active and passive storage systems are proposed as technologies that may be used to mitigate the effects of intermittence due to renewable generation. Commercial building technologies as well as industrial facilities with storage capability are identified as targets for the field tests. Two systems used for ancillary services communications are identified as providing the triggers for DR enablement. Through the field tests, issues related to communication, automation and flexibility of demand-side resources will be explored and the performance of technologies that participate in the field tests will be evaluated. The major outcome of this research is identifying and defining flexibility of DR resources and optimized use of these resources to respond to grid conditions.

  5. Congestion Control Mechanism for Intermittently Connected Wireless Network

    Directory of Open Access Journals (Sweden)

    Ruyan Wang

    2016-01-01

    Full Text Available Based on the “storing-carrying-forwarding” transmission manner, the packets are forwarded flexibly in Intermittently Connected Wireless Network (ICWN. However, due to its limited resources, ICWN can easily become congested as a large number of packets entering into it. In such situation, the network performance is seriously deteriorated. To solve this problem, we propose a congestion control mechanism that is based on the network state dynamic perception. Specifically, through estimating the congestion risk when a node receives packets, ICWN can reduce the probability of becoming congested. Moreover, due to ICWN’s network dynamics, we determine the congestion risk threshold by jointly taking into account the average packet size, average forwarding risk, and available buffer resources. Further, we also evaluate the service ability of a node in a distributed manner by integrating the recommendation information from other intermediate nodes. Additionally, a node is selected as a relay node according to both the congestion risk and service ability. Simulation results show that the network performance can be greatly optimized by reducing the overhead of packet forwarding.

  6. Effectiveness of intermittent diazepam prophylaxis in febrile seizures: long-term prospective controlled study.

    Science.gov (United States)

    Pavlidou, Efterpi; Tzitiridou, Maria; Panteliadis, Christos

    2006-12-01

    The efficacy of intermittent rectal diazepam prophylaxis is assessed in the prevention of febrile seizures. In a prospective randomized cohort trial, 139 children (77 girls, 62 boys) who experienced a first febrile seizure were allocated to two groups: group A, which received intermittent diazepam (n = 68), and group B, which received no prophylaxis (n = 71). All children had a 3-year follow-up. The inclusion criteria were no personal history of afebrile seizures, normal neurodevelopment, no previous anticonvulsant therapy, and age between 6 months and 3 years. Each group was stratified to low, intermediate, and high risk according to the available clinical data. The 36-month recurrence rates in the no-prophylaxis group were 83% in high-risk patients, 55% in intermediate-risk patients, and 46% in low-risk patients. In the prophylaxis group, the recurrence rates were reduced in all risk groups: 38%, 35%, and 33%, respectively. Intermittent diazepam prophylaxis reduces the recurrence rate mainly in high-risk children provided that sufficient doses are given on time and adequately.

  7. Optimization and universality of Brownian search in a basic model of quenched heterogeneous media

    Science.gov (United States)

    Godec, Aljaž; Metzler, Ralf

    2015-05-01

    The kinetics of a variety of transport-controlled processes can be reduced to the problem of determining the mean time needed to arrive at a given location for the first time, the so-called mean first-passage time (MFPT) problem. The occurrence of occasional large jumps or intermittent patterns combining various types of motion are known to outperform the standard random walk with respect to the MFPT, by reducing oversampling of space. Here we show that a regular but spatially heterogeneous random walk can significantly and universally enhance the search in any spatial dimension. In a generic minimal model we consider a spherically symmetric system comprising two concentric regions with piecewise constant diffusivity. The MFPT is analyzed under the constraint of conserved average dynamics, that is, the spatially averaged diffusivity is kept constant. Our analytical calculations and extensive numerical simulations demonstrate the existence of an optimal heterogeneity minimizing the MFPT to the target. We prove that the MFPT for a random walk is completely dominated by what we term direct trajectories towards the target and reveal a remarkable universality of the spatially heterogeneous search with respect to target size and system dimensionality. In contrast to intermittent strategies, which are most profitable in low spatial dimensions, the spatially inhomogeneous search performs best in higher dimensions. Discussing our results alongside recent experiments on single-particle tracking in living cells, we argue that the observed spatial heterogeneity may be beneficial for cellular signaling processes.

  8. New Zealand Blackcurrant Extract Improves High-Intensity Intermittent Running.

    Science.gov (United States)

    Perkins, Ian Craig; Vine, Sarah Anne; Blacker, Sam David; Willems, Mark Elisabeth Theodorus

    2015-10-01

    We examined the effect of New Zealand blackcurrant (NZBC) extract on high-intensity intermittent running and postrunning lactate responses. Thirteen active males (age: 25 ± 4 yrs, height: 1.82 ± 0.07 m, body mass: 81 ± 14 kg, VO2max: 56 ± 4 ml·kg-1·min-1, vVO2max: 17.6 ± 0.8 km·h-1) performed a treadmill running protocol to exhaustion, which consisted of stages with 6 × 19 s of sprints with 15 s of low-intensity running between sprints. Interstage rest time was 1 min and stages were repeated with increasing sprint speeds. Subjects consumed capsuled NZBC extract (300 mg·day-1 CurraNZ; containing 105 mg anthocyanin) or placebo for 7 days (double-blind, randomized, crossover design, wash-out at least 14 days). Blood lactate was collected for 30 min postexhaustion. NZBC increased total running distance by 10.6% (NZBC: 4282 ± 833 m, placebo: 3871 ± 622 m, p = .02), with the distance during sprints increased by 10.8% (p = .02). Heart rate, oxygen uptake, lactate and rating of perceived exertion were not different between conditions for the first 4 stages completed by all subjects. At exhaustion, blood lactate tended to be higher for NZBC (NZBC: 6.01 ± 1.07 mmol·L-1, placebo: 5.22 ± 1.52 mmol·L-1, p = .07). There was a trend for larger changes in lactate following 15 min (NZBC: -2.89 ± 0.51 mmol·L-1, placebo: -2.46 ± 0.39 mmol·L-1, p = .07) of passive recovery. New Zealand blackcurrant extract (CurraNZ) may enhance performance in sports characterized by high-intensity intermittent exercise as greater distances were covered with repeated sprints, there was higher lactate at exhaustion, and larger changes in lactate during early recovery after repeated sprints to exhaustion.

  9. Short-term intermittent energy restriction interventions for weight management: a systematic review and meta-analysis.

    Science.gov (United States)

    Harris, L; McGarty, A; Hutchison, L; Ells, L; Hankey, C

    2017-10-04

    This systematic review synthesized the available evidence on the effect of short-term periods of intermittent energy restriction (weekly intermittent energy restriction; ≥7-d energy restriction) in comparison with usual care (daily continuous energy restriction), in the treatment of overweight and obesity in adults. Six electronic databases were searched from inception to October 2016. Only randomized controlled trials of interventions (≥12 weeks) in adults with overweight and obesity were included. Five studies were included in this review. Weekly intermittent energy restriction periods ranged from an energy intake between 1757 and 6276 kJ/d(-1) . The mean duration of the interventions was 26 (range 14 to 48) weeks. Meta-analysis demonstrated no significant difference in weight loss between weekly intermittent energy restriction and continuous energy restriction post-intervention (weighted mean difference: -1.36 [-3.23, 0.51], p = 0.15) and at follow-up (weighted mean difference: -0.82 [-3.76, 2.11], p = 0.58). Both interventions achieved comparable weight loss of >5 kg and therefore were associated with clinical benefits to health. The findings support the use of weekly intermittent energy restriction as an alternative option for the treatment of obesity. Currently, there is insufficient evidence to support the long-term sustainable effects of weekly intermittent energy restriction on weight management. © 2017 The Authors. Obesity Reviews published by John Wiley & Sons Ltd on behalf of World Obesity.

  10. A Conservation Voltage Reduction Scheme for a Distribution Systems with Intermittent Distributed Generators

    Directory of Open Access Journals (Sweden)

    Pyeong-Ik Hwang

    2016-08-01

    Full Text Available In this paper, a conservation voltage reduction (CVR scheme is proposed for a distribution system with intermittent distributed generators (DGs, such as photovoltaics and wind turbines. The CVR is a scheme designed to reduce energy consumption by lowering the voltages supplied to customers. Therefore, an unexpected under-voltage violation can occur due to the variation of active power output from the intermittent DGs. In order to prevent the under-voltage violation and improve the CVR effect, a new reactive power controller which complies with the IEEE Std. 1547TM, and a parameter determination method for the controller are proposed. In addition, an optimal power flow (OPF problem to determine references for the resources of CVR is formulated with consideration of the intermittent DGs. The proposed method is validated using a modified IEEE 123-node test feeder. With the proposed method, the voltages of the test system are maintained to be greater than the lower bound, even though the active power outputs of the DGs are varied. Moreover, the CVR effect is improved compared to that used with the conventional reactive power control methods.

  11. Enteral nutrition in critical patients; should the administration be continuous or intermittent?

    Science.gov (United States)

    Tavares de Araujo, Viviane Maeve; Gomes, Paulo César; Caporossi, Cervantes

    2014-03-01

    Enteral nutrition therapy (ENT) is an essential part in the management of critically ill patients, having a significant impact on these patients' clinical results. It can be administered on a continuous or intermittent basis using an infusion pump. There is a discussion on which of these techniques has the best performance, involving a number of factors such as nausea, diarrhea, and particularly the relationship between diet volume and the ratio of programed calories to calories effectively supplied to the critical patients. To compare the forms of continuous or intermittent infusion of enteral nutrition, using as primary outcome the level of estimated caloric needs daily supplied. Observational prospective randomized clinical study carried out in an intensive care unit on 41 patients divided into two groups, of intermittent (ENT during 18 hours with a 6-hour nocturnal pause), or continuous (ENT during 24 hours continuously) administration. The secondary outcome variables measured in this study were bowel evacuation, distension, emesis, with the primary outcome variable being the relationship between infusion volume and the estimated-to-supplied ratio of caloric needs. The rejection index of the null hypothesis was established at 5% for all the tests. Most of the patients received more than 60% infusion of enteral diet over the 5 days of study (p = 1.0), with no difference regarding the provision of caloric needs. No statistically significant difference between groups was found in the variables vomiting, abdominal distension or diarrhea. The administration modalities of continuous or intermittent enteral nutrition are similar in which regards the comparison of the variables included in this study. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

  12. Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players

    Science.gov (United States)

    Nyakayiru, Jean; Jonvik, Kristin L.; Trommelen, Jorn; Pinckaers, Philippe J. M.; Senden, Joan M.; van Loon, Luc J. C.; Verdijk, Lex B.

    2017-01-01

    It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club) participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR) or a nitrate-depleted beetroot juice (PLA) for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR) was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA (p < 0.001), and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027). Mean HR was lower in the BR (172 ± 2) vs. PLA trial (175 ± 2; p = 0.014). Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players. PMID:28327503

  13. Beetroot Juice Supplementation Improves High-Intensity Intermittent Type Exercise Performance in Trained Soccer Players

    Directory of Open Access Journals (Sweden)

    Jean Nyakayiru

    2017-03-01

    Full Text Available It has been shown that nitrate supplementation can enhance endurance exercise performance. Recent work suggests that nitrate ingestion can also increase intermittent type exercise performance in recreational athletes. We hypothesized that six days of nitrate supplementation can improve high-intensity intermittent type exercise performance in trained soccer players. Thirty-two male soccer players (age: 23 ± 1 years, height: 181 ± 1 m, weight: 77 ± 1 kg, playing experience: 15.2 ± 0.5 years, playing in the first team of a 2nd or 3rd Dutch amateur league club participated in this randomized, double-blind cross-over study. All subjects participated in two test days in which high-intensity intermittent running performance was assessed using the Yo-Yo IR1 test. Subjects ingested nitrate-rich (140 mL; ~800 mg nitrate/day; BR or a nitrate-depleted beetroot juice (PLA for six subsequent days, with at least eight days of wash-out between trials. The distance covered during the Yo-Yo IR1 was the primary outcome measure, while heart rate (HR was measured continuously throughout the test, and a single blood and saliva sample were collected just prior to the test. Six days of BR ingestion increased plasma and salivary nitrate and nitrite concentrations in comparison to PLA (p < 0.001, and enhanced Yo-Yo IR1 test performance by 3.4 ± 1.3% (from 1574 ± 47 to 1623 ± 48 m; p = 0.027. Mean HR was lower in the BR (172 ± 2 vs. PLA trial (175 ± 2; p = 0.014. Six days of BR ingestion effectively improves high-intensity intermittent type exercise performance in trained soccer players.

  14. A wavelet-based intermittency detection technique from PIV investigations in transitional boundary layers

    Science.gov (United States)

    Simoni, Daniele; Lengani, Davide; Guida, Roberto

    2016-09-01

    The transition process of the boundary layer growing over a flat plate with pressure gradient simulating the suction side of a low-pressure turbine blade and elevated free-stream turbulence intensity level has been analyzed by means of PIV and hot-wire measurements. A detailed view of the instantaneous flow field in the wall-normal plane highlights the physics characterizing the complex process leading to the formation of large-scale coherent structures during breaking down of the ordered motion of the flow, thus generating randomized oscillations (i.e., turbulent spots). This analysis gives the basis for the development of a new procedure aimed at determining the intermittency function describing (statistically) the transition process. To this end, a wavelet-based method has been employed for the identification of the large-scale structures created during the transition process. Successively, a probability density function of these events has been defined so that an intermittency function is deduced. This latter strictly corresponds to the intermittency function of the transitional flow computed trough a classic procedure based on hot-wire data. The agreement between the two procedures in the intermittency shape and spot production rate proves the capability of the method in providing the statistical representation of the transition process. The main advantages of the procedure here proposed concern with its applicability to PIV data; it does not require a threshold level to discriminate first- and/or second-order time-derivative of hot-wire time traces (that makes the method not influenced by the operator); and it provides a clear evidence of the connection between the flow physics and the statistical representation of transition based on theory of turbulent spot propagation.

  15. Enteral nutrition in critical patients: should the administration be continuous or intermittent?

    Directory of Open Access Journals (Sweden)

    Viviane Maeve Tavares de Araujo

    2014-03-01

    Full Text Available Enteral nutrition therapy (ENT is an essential part in the management of critically ill patients, having a significant impact on these patients´ clinical results. It can be administered on a continuous or intermittent basis using an infusion pump. There is a discussion on which of these techniques has the best performance, involving a number of factors such as nausea, diarrhea, and particularly the relationship between diet volume and the ratio of programed calories to calories effectively supplied to the critical patients. Objectives: To compare the forms of continuous or intermittent infusion of enteral nutrition, using as primary outcome the level of estimated caloric needs daily supplied. Methods: Observational prospective randomized clinical study carried out in an intensive care unit on 41 patients divided into two groups, of intermittent (ENT during 18 hours with a 6-hour nocturnal pause, or continuous (ENT during 24 hours continuously administration. The secondary outcome variables measured in this study were bowel evacuation, distension, emesis, with the primary outcome variable being the relationship between infusion volume and the estimated-to-supplied ratio of caloric needs. The rejection index of the null hypothesis was established at 5% for all the tests. Results: Most of the patients received more than 60% infusion of enteral diet over the 5 days of study (p = 1.0, with no difference regarding the provision of caloric needs. No statistically significant difference between groups was found in the variables vomiting, abdominal distension or diarrhea. Conclusion: The administration modalities of continuous or intermittent enteral nutrition are similar in which regards the comparison of the variables included in this study.

  16. High-intensity intermittent swimming improves cardiovascular health status for women with mild hypertension

    DEFF Research Database (Denmark)

    Mohr, Magni; Nordsborg, Nikolai Baastrup; Lindenskov, Annika;

    2014-01-01

    To test the hypothesis that high-intensity swim training improves cardiovascular health status in sedentary premenopausal women with mild hypertension, sixty-two women were randomized into high-intensity (n = 21; HIT), moderate-intensity (n = 21; MOD), and control groups (n = 20; CON). HIT...... high-intensity intermittent swimming is an effective training strategy to improve cardiovascular health and physical performance...... in sedentary women with mild hypertension. Adaptations are similar with high- and moderate-intensity training, despite markedly less total time spent and distance covered in the high-intensity group....

  17. The effect of high-intensity intermittent exercise on body composition of overweight young males.

    Science.gov (United States)

    Heydari, M; Freund, J; Boutcher, S H

    2012-01-01

    To determine the effect of a 12-week high intensity intermittent exercise (HIIE) intervention on total body, abdominal, trunk, visceral fat mass, and fat free mass of young overweight males. Participants were randomly assigned to either exercise or control group. The intervention group received HIIE three times per week, 20 min per session, for 12 weeks. Aerobic power improved significantly (P 0.05) occurred in levels of insulin, HOMA-IR, and blood lipids. Twelve weeks of HIIE resulted in significant reductions in total, abdominal, trunk, and visceral fat and significant increases in fat free mass and aerobic power.

  18. FBSDE with Poisson Process and Its Application to Linear Quadratic Stochastic Optimal Control Problem with Random Jumps%带有随机跳跃干扰的线性二次随机最优控制问题

    Institute of Scientific and Technical Information of China (English)

    吴臻; 王向荣

    2003-01-01

    给出一类布朗运动和泊松过程混合驱动的正倒向随机微分方程解的存在唯一性结果,应用这一结果研究带有随机跳跃干扰的线性二次随机最优控制问题,并得到最优控制的显式形式,可以证明最优控制是唯一的.然后,引入和研究一类推广的黎卡提方程系统,讨论该方程系统的可解性并由该方程的解得到带有随机跳跃干扰的线性二次随机最优控制问题最优的线性反馈.%One kind of existence and uniqueness result of forward-backward stochastic differential equations with Brownian motion and Poisson process is given. The result is applied to get the explicit form of the optimal control for linear quadratic stochastic optimal control problem with random jumps. The optimal control can be proved to be unique. One kind of generalized Riccati equation system is introduced and its solvability is discussed. The linear feedback regulator for the optimal control problem with random jump is given by the solution of the generalized Riccati equation system

  19. Intermittency as a universal characteristic of the complete chromosome DNA sequences of eukaryotes: From protozoa to human genomes

    Science.gov (United States)

    Rybalko, S.; Larionov, S.; Poptsova, M.; Loskutov, A.

    2011-10-01

    Large-scale dynamical properties of complete chromosome DNA sequences of eukaryotes are considered. Using the proposed deterministic models with intermittency and symbolic dynamics we describe a wide spectrum of large-scale patterns inherent in these sequences, such as segmental duplications, tandem repeats, and other complex sequence structures. It is shown that the recently discovered gene number balance on the strands is not of a random nature, and certain subsystems of a complete chromosome DNA sequence exhibit the properties of deterministic chaos.

  20. Enhanced sarcoplasmic reticulum Ca(2+) release following intermittent sprint training

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Lunde, Per; Levin, Kasper

    2000-01-01

    To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after...... the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% (P training. The 5-wk sprint training induced a significantly higher (P ...-977) arbitrary units Ca(2+). g protein(-1). min(-1) (after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% (P

  1. Evaluation of continuous and intermittent myocardial topical negative pressure

    DEFF Research Database (Denmark)

    Lindstedt, Sandra; Malmsjö, Malin; Gesslein, Bodil

    2008-01-01

    to intermittent therapy shows twice as much granulation tissue formation than that exposed to continuous pressure after 2 weeks of therapy. The present study was designed to elucidate the differences in microvascular blood flow in the left anterior descending artery area between continuous and intermittent......Topical negative pressure, commonly used in wound therapy, has been shown to increase blood flow and stimulate angiogenesis in subcutaneous tissue and skeletal muscle. In wound therapy, intermittent negative pressure is often preferred to continuous negative pressure as tissue exposed...... myocardial topical negative pressure of -50 mmHg....

  2. Enhanced sarcoplasmic reticulum Ca(2+) release following intermittent sprint training

    DEFF Research Database (Denmark)

    Ørtenblad, Niels; Lunde, Per; Levin, Kasper

    2000-01-01

    To evaluate the effect of intermittent sprint training on sarcoplasmic reticulum (SR) function, nine young men performed a 5 wk high-intensity intermittent bicycle training, and six served as controls. SR function was evaluated from resting vastus lateralis muscle biopsies, before and after...... the training period. Intermittent sprint performance (ten 8-s all-out periods alternating with 32-s recovery) was enhanced 12% (P training. The 5-wk sprint training induced a significantly higher (P ...-977) arbitrary units Ca(2+). g protein(-1). min(-1) (after). The relative SR density of functional ryanodine receptors (RyR) remained unchanged after training; there was, however, a 48% (P

  3. Photoluminescence intermittency of semiconductor quantum dots in dielectric environments

    Energy Technology Data Exchange (ETDEWEB)

    Isaac, A.

    2006-08-11

    The experimental studies presented in this thesis deal with the photoluminescence intermittency of semiconductor quantum dots in different dielectric environments. Detailed analysis of intermittency statistics from single capped CdSe/ZnS, uncapped CdSe and water dispersed CdSe/ZnS QDs in different matrices provide experimental evidence for the model of photoionization with a charge ejected into the surrounding matrix as the source of PL intermittency phenomenon. We propose a self-trapping model to explain the increase of dark state lifetimes with the dielectric constant of the matrix. (orig.)

  4. Characterizing and Comparing Young Adult Intermittent and Daily Smokers

    OpenAIRE

    Lenk, Kathleen M.; Chen, Vincent; Bernat, Debra H.; Forster, Jean L.; Rode, Peter A.

    2009-01-01

    To examine young adult smoking patterns, we interviewed 732 smokers (from five U.S. upper Midwestern states) via telephone in 2006. We first defined two groups of intermittent smokers—low (smoked 1–14 days in past 30) and high (smoked 15–29 days in past 30), and then analyzed differences between these two groups and daily smokers. Low intermittent smokers were much less likely than high intermittent smokers to consider themselves smokers, feel addicted, or smoke with friends. Daily smokers we...

  5. Removing Barriers for Effective Deployment of Intermittent Renewable Generation

    Science.gov (United States)

    Arabali, Amirsaman

    The stochastic nature of intermittent renewable resources is the main barrier to effective integration of renewable generation. This problem can be studied from feeder-scale and grid-scale perspectives. Two new stochastic methods are proposed to meet the feeder-scale controllable load with a hybrid renewable generation (including wind and PV) and energy storage system. For the first method, an optimization problem is developed whose objective function is the cost of the hybrid system including the cost of renewable generation and storage subject to constraints on energy storage and shifted load. A smart-grid strategy is developed to shift the load and match the renewable energy generation and controllable load. Minimizing the cost function guarantees minimum PV and wind generation installation, as well as storage capacity selection for supplying the controllable load. A confidence coefficient is allocated to each stochastic constraint which shows to what degree the constraint is satisfied. In the second method, a stochastic framework is developed for optimal sizing and reliability analysis of a hybrid power system including renewable resources (PV and wind) and energy storage system. The hybrid power system is optimally sized to satisfy the controllable load with a specified reliability level. A load-shifting strategy is added to provide more flexibility for the system and decrease the installation cost. Load shifting strategies and their potential impacts on the hybrid system reliability/cost analysis are evaluated trough different scenarios. Using a compromise-solution method, the best compromise between the reliability and cost will be realized for the hybrid system. For the second problem, a grid-scale stochastic framework is developed to examine the storage application and its optimal placement for the social cost and transmission congestion relief of wind integration. Storage systems are optimally placed and adequately sized to minimize the sum of operation

  6. Intermittent Renewable Management Pilot Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Kiliccote, Sila [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Homan, Gregory [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Anderson, Robert [Olivine, Inc., San Ramon, CA (United States); Hernandez, John [Pacific Gas & Electric Company, San Francisco, CA (United States)

    2015-04-01

    The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with direct participation of third-parties and customers including customer acceptance; market transformation challenges (wholesale market, technology); technical and operational feasibility; and value to the rate payers, DR resource owners and the utility on providing an enabling mechanism for DR resources into the wholesale markets. The customer had the option of committing to either three contiguous hour blocks for 24 days or six contiguous hours for 12 days a month with day-ahead notification that aligned with the CAISO integrated forward market. As a result of their being available, the customer was paid $10/ kilowatt (kW)-month for capacity in addition to CAISO energy settlements. The participants were limited to no more than a 2 megawatt (MW) capacity with a six-month commitment. Four participants successfully engaged in the pilot. In this report, we provide the description of the pilot, participant performance results, costs and value to participants as well as outline some of the issues encountered through the pilot. Results show that participants chose to participate with storage and the value of CAISO settlements were significantly lower than the capacity payments provided by the utility as incentive payments. In addition, this pilot revealed issues both on the participant side and system operations side. These issues are summarized in the report.The Intermittent Renewable Management Pilot - Phase 2 (IRM2) was designed to study the feasibility of demand-side resources to participate into the California Independent System Operator (CAISO) wholesale market as proxy demand resources (PDR). The pilot study focused on understanding the issues related with

  7. Random broadcast on random geometric graphs

    Energy Technology Data Exchange (ETDEWEB)

    Bradonjic, Milan [Los Alamos National Laboratory; Elsasser, Robert [UNIV OF PADERBORN; Friedrich, Tobias [ICSI/BERKELEY; Sauerwald, Tomas [ICSI/BERKELEY

    2009-01-01

    In this work, we consider the random broadcast time on random geometric graphs (RGGs). The classic random broadcast model, also known as push algorithm, is defined as: starting with one informed node, in each succeeding round every informed node chooses one of its neighbors uniformly at random and informs it. We consider the random broadcast time on RGGs, when with high probability: (i) RGG is connected, (ii) when there exists the giant component in RGG. We show that the random broadcast time is bounded by {Omicron}({radical} n + diam(component)), where diam(component) is a diameter of the entire graph, or the giant component, for the regimes (i), or (ii), respectively. In other words, for both regimes, we derive the broadcast time to be {Theta}(diam(G)), which is asymptotically optimal.

  8. Cutaneous sporotrichosis. Intermittent treatment (pulses) with itraconazole.

    Science.gov (United States)

    Bonifaz, Alexandro; Fierro, Leonel; Saúl, Amado; Ponce, Rosa María

    2008-01-01

    Sporotrichosis is a subcutaneous and exceptionally deep mycosis caused by a dimorphic fungus, Sporothrix schenckii. Itraconazole is a triazole derivative leading to good results in the treatment of sporotrichosis. Patients with cutaneous sporotrichosis proven with mycological tests (direct examination and culture) were enrolled. All patients underwent laboratory tests (at baseline and on a monthly basis) and received oral itraconazole 400 mg/day for one week with a 3-week break (pulses); thereafter the drug was administered as pulses until clinical and mycological cure was achieved. Five patients with sporotrichosis were enrolled, 4 with cutaneous lymphangitic form and one with fixed cutaneous form. Clinical and mycological cure was achieved in 4/5 cases (80%), with a mean number of pulses of 3.5. No patient had side effects and no laboratory test abnormalities occurred. Intermittent or pulsed itraconazole was effective in treating cutaneous sporotrichosis. It may be considered as a new treatment choice that entails an important reduction in total medication use.

  9. Contraction stress test by intermittent nipple stimulation.

    Science.gov (United States)

    Huddleston, J F; Sutliff, G; Robinson, D

    1984-05-01

    Although the nonstress test has generally supplanted the contraction stress test as the primary test for assessment of fetal well-being, the contraction stress test continues to be useful. Objectionable factors of the contraction stress test have included the time required to complete the test and the frequent necessity for intravenous oxytocin. The authors developed a contraction stress test protocol using contractions produced by intermittent nipple stimulation and used the method for 345 tests on 193 high-risk pregnancies during a 15-month period. The women were instructed to stimulate one breast, through their clothes, for two minutes and then to rest for five minutes. This cycle was repeated as necessary, but was interrupted whenever contractions began. Using this protocol, the authors were successful in achieving an adequate contraction frequency with every attempt, and hyperstimulation was not more frequent than previously reported with the standard contraction stress test. The average time requirement was 45 minutes. No unexplained stillbirths occurred after a negative test.

  10. Acute Intermittent Porphyria in Argentina: An Update

    Directory of Open Access Journals (Sweden)

    Gabriela Nora Cerbino

    2015-01-01

    Full Text Available Porphyrias are a group of metabolic diseases that arise from deficiencies in the heme biosynthetic pathway. A partial deficiency in hydroxymethylbilane synthase (HMBS produces a hepatic disorder named Acute Intermittent Porphyria (AIP; the acute porphyria is more frequent in Argentina. In this paper we review the results obtained for 101 Argentinean AIP families and 6 AIP families from foreign neighbour countries studied at molecular level at Centro de Investigaciones sobre Porfirinas y Porfirias (CIPYP. Thirty-five different mutations were found, of which 14 were described for the first time in our population. The most prevalent type of mutations was the missense mutations (43% followed by splice defects (26% and small deletions (20%. An odd case of a double heterozygous presentation of AIP in a foreign family from Paraguay is discussed. Moreover, it can be noted that 38 new families were found carrying the most frequent mutation in Argentina (p.G111R, increasing to 55.66% the prevalence of this genetic change in our population and adding further support to our previous hypothesis of a founder effect for this mutation in Argentina. Identification of patients with an overt AIP is important because treatment depends on an accurate diagnosis, but more critical is the identification of asymptomatic relatives to avoid acute attacks which may progress to death.

  11. Intermittent everolimus administration for malignant insulinoma

    Science.gov (United States)

    Brizzi, Maria Pia; Tampellini, Marco; Scagliotti, Giorgio Vittorio; Priola, Adriano; Terzolo, Massimo; Pia, Anna; Berruti, Alfredo

    2014-01-01

    Summary Insulinoma is a rare form of insulin-secreting pancreatic islet cell neuroendocrine (NE) tumor. The medical treatment of the malignant NE disease of the pancreas deeply changed in the last years, thanks to the introduction of new target molecules, as everolimus. Even if the exact mechanism is not actually known, one of the side effects of everolimus, hyperglycemia, has been demonstrated to be useful to contrast the typical hypoglycemia of the insulinoma. We report the case of a patient with a metastatic malignant insulinoma treated with intermittent everolimus, obtaining an important improvement in the quality of life; this suggests the necessity of preclinical studies to analyze the cellular pathways involved in insulin-independent gluconeogenesis. Learning points Effect of somatostatin analogs is long-lasting in the control of functioning NE tumors.Persistent everolimus control of hypoglycemia despite serum insulin levels and disease progression.Open issue: are disease progression and the increase in serum markers the only valid criteria to reject a treatment? PMID:25298880

  12. Long-range forecasting of intermittent streamflow

    Directory of Open Access Journals (Sweden)

    F. F. van Ogtrop

    2011-01-01

    Full Text Available Long-range forecasting of intermittent streamflow in semi-arid Australia poses a number of major challenges. One of the challenges relates to modelling zero, skewed, non-stationary, and non-linear data. To address this, a probabilistic statistical model to forecast streamflow 12 months ahead is applied to five semi-arid catchments in South Western Queensland. The model uses logistic regression through Generalised Additive Models for Location, Scale and Shape (GAMLSS to determine the probability of flow occurring in any of the systems. We then use the same regression framework in combination with a right-skewed distribution, the Box-Cox t distribution, to model the intensity (depth of the non-zero streamflows. Time, seasonality and climate indices, describing the Pacific and Indian Ocean sea surface temperatures, are tested as covariates in the GAMLSS model to make probabilistic 12-month forecasts of the occurrence and intensity of streamflow. The output reveals that in the study region the occurrence and variability of flow is driven by sea surface temperatures and therefore forecasts can be made with some skill.

  13. Multifractality and intermittency in the solar wind

    Directory of Open Access Journals (Sweden)

    W. M. Macek

    2007-11-01

    Full Text Available Within the complex dynamics of the solar wind's fluctuating plasma parameters, there is a detectable, hidden order described by a chaotic strange attractor which has a multifractal structure. The multifractal spectrum has been investigated using Voyager (magnetic field data in the outer heliosphere and using Helios (plasma data in the inner heliosphere. We have also analyzed the spectrum for the solar wind attractor. The spectrum is found to be consistent with that for the multifractal measure of the self-similar one-scale weighted Cantor set with two parameters describing uniform compression and natural invariant probability measure of the attractor of the system. In order to further quantify the multifractality, we also consider a generalized weighted Cantor set with two different scales describing nonuniform compression. We investigate the resulting multifractal spectrum depending on two scaling parameters and one probability measure parameter, especially for asymmetric scaling. We hope that this generalized model will also be a useful tool for analysis of intermittent turbulence in space plasmas.

  14. Challenges, developments and perspectives in intermittent ...

    Science.gov (United States)

    Although more than half the world's river networks comprise channels that periodically cease to flow and dry [intermittent rivers (IRs)], river ecology was largely developed from and for perennial systems. Ecological knowledge of IRs is rapidly increasing, so there is a need to synthesise this knowledge and deepen ecological understanding.In this Special Issue, we bring together 13 papers spanning observational case studies, field and laboratory experiments and reviews to guide research and management in this productive field of freshwater science. We summarise new developments in IR ecology, identify research gaps and needs, and address how the study of IRs as highly dynamic ecosystems informs ecological understanding more broadly.This series of articles reveals that contemporary IR ecology is a multifaceted and maturing field of research at the interface between aquatic and terrestrial ecology. This research contributes to fresh water and general ecology by testing concepts across a range of topics, including disturbance ecology, metacommunity ecology and coupled aquatic-terrestrial ecosystems.Drying affects flow continuity through time and flow connectivity across longitudinal, lateral and vertical dimensions of space, which aligns well with the recent emphasis of mainstream ecology on meta-system perspectives. Although most articles here focus on the wet phase, there is growing interest in dry phases, and in the terrestrial vegetation and invertebrate assemb

  15. Sex differences associated with intermittent swim stress.

    Science.gov (United States)

    Warner, Timothy A; Libman, Matthew K; Wooten, Katherine L; Drugan, Robert C

    2013-11-01

    Various animal models of depression have been used to seek a greater understanding of stress-related disorders. However, there is still a great need for novel research in this area, as many individuals suffering from depression are resistant to current treatment methods. Women have a higher rate of depression, highlighting the need to investigate mechanisms of sex differences. Therefore, we employed a new animal model to assess symptoms of depression, known as intermittent swim stress (ISS). In this model, the animal experiences 100 trials of cold water swim stress. ISS has already been shown to cause signs of behavioral depression in males, but has yet to be assessed in females. Following ISS exposure, we looked at sex differences in the Morris water maze and forced swim test. The results indicated a spatial learning effect only in the hidden platform task between male and female controls, and stressed and control males. A consistent spatial memory effect was only seen for males exposed to ISS. In the forced swim test, both sexes exposed to ISS exhibited greater immobility, and the same males and females also showed attenuated climbing and swimming, respectively. The sex differences could be due to different neural substrates for males and females. The goal of this study was to provide the first behavioral examination of sex differences following ISS exposure, so the stage of estrous cycle was not assessed for the females. This is a necessary future direction for subsequent experiments. The current article highlights the importance of sex differences in response to stress.

  16. Finite dissipation and intermittency in magnetohydrodynamics.

    Science.gov (United States)

    Mininni, P D; Pouquet, A

    2009-08-01

    We present an analysis of data stemming from numerical simulations of decaying magnetohydrodynamic (MHD) turbulence up to grid resolution of 1536(3) points and up to Taylor Reynolds number of approximately 1200 . The initial conditions are such that the initial velocity and magnetic fields are helical and in equipartition, while their correlation is negligible. Analyzing the data at the peak of dissipation, we show that the dissipation in MHD seems to asymptote to a constant as the Reynolds number increases, thereby strengthening the possibility of fast reconnection events in the solar environment for very large Reynolds numbers. Furthermore, intermittency of MHD flows, as determined by the spectrum of anomalous exponents of structure functions of the velocity and the magnetic field, is stronger than that of fluids, confirming earlier results; however, we also find that there is a measurable difference between the exponents of the velocity and those of the magnetic field, reminiscent of recent solar wind observations. Finally, we discuss the spectral scaling laws that arise in this flow.

  17. Intermittent priapism as a clinical feature of lumbar spinal stenosis

    National Research Council Canada - National Science Library

    Rojas, J I; Zurrú-Ganen, M C; Romano, M; Patrucco, L; Cristiano, E

    2007-01-01

    .... Patients with lumbar spinal stenosis may present a variety of signs and symptoms. One such syndrome is neurogenic intermittent claudication, characterized by radicular symptoms exacerbated by walking or standing and relieved by rest...

  18. Isolated intermittent vertigo: A presenting feature of persistent trigeminal artery

    Directory of Open Access Journals (Sweden)

    Rajsrinivas Parthasarathy

    2016-01-01

    Full Text Available Embryonic carotid – basilar anastomosis when persistent in adult life can present with a variety of neurological symptoms. We present a patient with isolated intermittent vertigo attributable to the embryonic anastomosis and describe the different types of persistent trigeminal artery. A 76-year-old Caucasian man presented with isolated intermittent vertigo and symptoms suggestive of anterior and posterior circulation strokes. Impaired vasomotor reactivity was demonstrated on insonation of the anterior and posterior cerebral arteries in this patient with a persistent left trigeminal artery and 75% stenosis of the left internal carotid artery (ICA. The symptom of intermittent vertigo resolved with carotid endarterectomy. Decreased flow across the stenotic segment of the ICA which subserved the posterior circulation resulted in basilar insufficiency. Hypoperfusion to the flocculonodular lobe supplied by the anterior inferior cerebellar artery is a likely cause for the intermittent vertigo.

  19. Revealing Intermittency in Nuclear Multifragmentation with 4$\\PI$ Detectors

    CERN Document Server

    Baldo, Marcello; Rapisarda, A

    1993-01-01

    The distortion on the intermittency signal, due to detection efficiency and to the presence of pre--equilibrium emitted particles, is studied in a schematic model of nuclear multi- fragmentation. The source of the intermittency signal is modeled with a percolating system. The efficiency is schematized by a simple function of the fragment size, and the presence of pre--equilibrium particles is simulated by an additional non--critical fragment source. No selection on the events is considered, and therefore all events are used to calculate the moments. It is found that, despite the absence of event selection, the intermittency signal is quite resistant to the distortion due to the apparatus efficiency, while the inclusion of pre--equilibrium particles in the moment calculation can substantially reduce the strength of the signal. Pre--equilibrium particles should be therefore carefully separated from the rest of the detected fragments, before the intermittency analysis on experimental charge or mass distributions...

  20. Sensing and characterization of EMI during intermittent connector anomalies

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents a new on-line methodology for detecting intermittent disconnection failures. The detection principle operates on the fundamental Lorentz Law that...