A new upper bound for the norm of interval matrices with application to robust stability analysis of delayed neural networks.

PubMed

Faydasicok, Ozlem; Arik, Sabri

2013-08-01

The main problem with the analysis of robust stability of neural networks is to find the upper bound norm for the intervalized interconnection matrices of neural networks. In the previous literature, the major three upper bound norms for the intervalized interconnection matrices have been reported and they have been successfully applied to derive new sufficient conditions for robust stability of delayed neural networks. One of the main contributions of this paper will be the derivation of a new upper bound for the norm of the intervalized interconnection matrices of neural networks. Then, by exploiting this new upper bound norm of interval matrices and using stability theory of Lyapunov functionals and the theory of homomorphic mapping, we will obtain new sufficient conditions for the existence, uniqueness and global asymptotic stability of the equilibrium point for the class of neural networks with discrete time delays under parameter uncertainties and with respect to continuous and slope-bounded activation functions. The results obtained in this paper will be shown to be new and they can be considered alternative results to previously published corresponding results. We also give some illustrative and comparative numerical examples to demonstrate the effectiveness and applicability of the proposed robust stability condition. Copyright © 2013 Elsevier Ltd. All rights reserved.

Stochastic parameter estimation in nonlinear time-delayed vibratory systems with distributed delay

NASA Astrophysics Data System (ADS)

Torkamani, Shahab; Butcher, Eric A.

2013-07-01

The stochastic estimation of parameters and states in linear and nonlinear time-delayed vibratory systems with distributed delay is explored. The approach consists of first employing a continuous time approximation to approximate the delayed integro-differential system with a large set of ordinary differential equations having stochastic excitations. Then the problem of state and parameter estimation in the resulting stochastic ordinary differential system is represented as an optimal filtering problem using a state augmentation technique. By adapting the extended Kalman-Bucy filter to the augmented filtering problem, the unknown parameters of the time-delayed system are estimated from noise-corrupted, possibly incomplete measurements of the states. Similarly, the upper bound of the distributed delay can also be estimated by the proposed technique. As an illustrative example to a practical problem in vibrations, the parameter, delay upper bound, and state estimation from noise-corrupted measurements in a distributed force model widely used for modeling machine tool vibrations in the turning operation is investigated.

A new delay-independent condition for global robust stability of neural networks with time delays.

PubMed

Samli, Ruya

2015-06-01

This paper studies the problem of robust stability of dynamical neural networks with discrete time delays under the assumptions that the network parameters of the neural system are uncertain and norm-bounded, and the activation functions are slope-bounded. By employing the results of Lyapunov stability theory and matrix theory, new sufficient conditions for the existence, uniqueness and global asymptotic stability of the equilibrium point for delayed neural networks are presented. The results reported in this paper can be easily tested by checking some special properties of symmetric matrices associated with the parameter uncertainties of neural networks. We also present a numerical example to show the effectiveness of the proposed theoretical results. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adjustment of Adaptive Gain with Bounded Linear Stability Analysis to Improve Time-Delay Margin for Metrics-Driven Adaptive Control

NASA Technical Reports Server (NTRS)

Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje Srinvas

2009-01-01

This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a linear damaged twin-engine generic transport model of aircraft. The analysis shows that the system with the adjusted adaptive gain becomes more robust to unmodeled dynamics or time delay.

Dwell time-based stabilisation of switched delay systems using free-weighting matrices

NASA Astrophysics Data System (ADS)

Koru, Ahmet Taha; Delibaşı, Akın; Özbay, Hitay

2018-01-01

In this paper, we present a quasi-convex optimisation method to minimise an upper bound of the dwell time for stability of switched delay systems. Piecewise Lyapunov-Krasovskii functionals are introduced and the upper bound for the derivative of Lyapunov functionals is estimated by free-weighting matrices method to investigate non-switching stability of each candidate subsystems. Then, a sufficient condition for the dwell time is derived to guarantee the asymptotic stability of the switched delay system. Once these conditions are represented by a set of linear matrix inequalities , dwell time optimisation problem can be formulated as a standard quasi-convex optimisation problem. Numerical examples are given to illustrate the improvements over previously obtained dwell time bounds. Using the results obtained in the stability case, we present a nonlinear minimisation algorithm to synthesise the dwell time minimiser controllers. The algorithm solves the problem with successive linearisation of nonlinear conditions.

Stochastic resonance in a tumor-immune system subject to bounded noises and time delay

NASA Astrophysics Data System (ADS)

Guo, Wei; Mei, Dong-Cheng

2014-12-01

Immunotherapy is one of the most recent approaches in cancer therapy. A mathematical model of tumor-immune interaction, subject to a periodic immunotherapy treatment (imitated by a periodic signal), correlative and bounded stochastic fluctuations and time delays, is investigated by numerical simulations for its signal power amplification (SPA). Within the tailored parameter regime, the synchronous response of tumor growth to the immunotherapy, stochastic resonance (SR), versus both the noises and delays is obtained. The details are as follows (i) the peak values of SPA versus the noise intensity (A) in the proliferation term of tumor cells decrease as the frequency of periodic signal increases, i.e. an increase of the frequency restrains the SR; (ii) an increase of the amplitude of periodic signal restrains the SR versus A, but boosts up the SR versus the noise intensity B in the immune term; (iii) there is an optimum cross-correlated degree between the two bounded noises, at which the system exhibits the strongest SR versus the delay time τα(the reaction time of tumor cell population to their surrounding environment constraints); (iv) upon increasing the delay time τα, double SR versus the delay time τβ (the time taken by both the tumor antigen identification and tumor-stimulated proliferation of effectors) emerges. These results may be helpful for an immunotherapy treatment for the sufferer.

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

NASA Astrophysics Data System (ADS)

Thanh, Vo Hong; Priami, Corrado; Zunino, Roberto

2014-10-01

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concrete biological models.

Evolutionary Calculations of Phase Separation in Crystallizing White Dwarf Stars

NASA Astrophysics Data System (ADS)

Montgomery, M. H.; Klumpe, E. W.; Winget, D. E.; Wood, M. A.

1999-11-01

We present an exploration of the significance of carbon/oxygen phase separation in white dwarf stars in the context of self-consistent evolutionary calculations. Because phase separation can potentially increase the calculated ages of the oldest white dwarfs, it can affect the age of the Galactic disk as derived from the downturn in the white dwarf luminosity function. We find that the largest possible increase in ages due to phase separation is ~1.5 Gyr, with a most likely value of approximately 0.6 Gyr, depending on the parameters of our white dwarf models. The most important factors influencing the size of this delay are the total stellar mass, the initial composition profile, and the phase diagram assumed for crystallization. We find a maximum age delay in models with masses of ~0.6 Msolar, which is near the peak in the observed white dwarf mass distribution. In addition, we note that the prescription that we have adopted for the mixing during crystallization provides an upper bound for the efficiency of this process, and hence a maximum for the age delays. More realistic treatments of the mixing process may reduce the size of this effect. We find that varying the opacities (via the metallicity) has little effect on the calculated age delays. In the context of Galactic evolution, age estimates for the oldest Galactic globular clusters range from 11.5 to 16 Gyr and depend on a variety of parameters. In addition, a 4-6 Gyr delay is expected between the formation of the globular clusters and the formation of the Galactic thin disk, while the observed white dwarf luminosity function gives an age estimate for the thin disk of 9.5+1.1-0.8 Gyr, without including the effect of phase separation. Using the above numbers, we see that phase separation could add between 0 and 3 Gyr to the white dwarf ages and still be consistent with the overall picture of Galaxy formation. Our calculated maximum value of <~1.5 Gyr fits within these bounds, as does our best-guess value of ~0.6 Gyr.

Efficient rejection-based simulation of biochemical reactions with stochastic noise and delays

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

Thanh, Vo Hong, E-mail: vo@cosbi.eu; Priami, Corrado, E-mail: priami@cosbi.eu; Department of Mathematics, University of Trento

2014-10-07

We propose a new exact stochastic rejection-based simulation algorithm for biochemical reactions and extend it to systems with delays. Our algorithm accelerates the simulation by pre-computing reaction propensity bounds to select the next reaction to perform. Exploiting such bounds, we are able to avoid recomputing propensities every time a (delayed) reaction is initiated or finished, as is typically necessary in standard approaches. Propensity updates in our approach are still performed, but only infrequently and limited for a small number of reactions, saving computation time and without sacrificing exactness. We evaluate the performance improvement of our algorithm by experimenting with concretemore » biological models.« less

Adaptive fuzzy predictive sliding control of uncertain nonlinear systems with bound-known input delay.

PubMed

Khazaee, Mostafa; Markazi, Amir H D; Omidi, Ehsan

2015-11-01

In this paper, a new Adaptive Fuzzy Predictive Sliding Mode Control (AFP-SMC) is presented for nonlinear systems with uncertain dynamics and unknown input delay. The control unit consists of a fuzzy inference system to approximate the ideal linearization control, together with a switching strategy to compensate for the estimation errors. Also, an adaptive fuzzy predictor is used to estimate the future values of the system states to compensate for the time delay. The adaptation laws are used to tune the controller and predictor parameters, which guarantee the stability based on a Lyapunov-Krasovskii functional. To evaluate the method effectiveness, the simulation and experiment on an overhead crane system are presented. According to the obtained results, AFP-SMC can effectively control the uncertain nonlinear systems, subject to input delays of known bound. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Delay Tracking of Spread-Spectrum Signals for Indoor Optical Ranging

PubMed Central

Salido-Monzú, David; Martín-Gorostiza, Ernesto; Lázaro-Galilea, José Luis; Martos-Naya, Eduardo; Wieser, Andreas

2014-01-01

Delay tracking of spread-spectrum signals is widely used for ranging in radio frequency based navigation. Its use in non-coherent optical ranging, however, has not been extensively studied since optical channels are less subject to narrowband interference situations where these techniques become more useful. In this work, an early-late delay-locked loop adapted to indoor optical ranging is presented and analyzed. The specific constraints of free-space infrared channels in this context substantially differ from those typically considered in radio frequency applications. The tracking stage is part of an infrared differential range measuring system with application to mobile target indoor localization. Spread-spectrum signals are used in this context to provide accurate ranging while reducing the effect of multipath interferences. The performance of the stage regarding noise and dynamic errors is analyzed and validated, providing expressions that allow an adequate selection of the design parameters depending on the expected input signal characteristics. The behavior of the stage in a general multipath scenario is also addressed to estimate the multipath error bounds. The results, evaluated under realistic conditions corresponding to an 870 nm link with 25 MHz chip-rate, built with low-cost up-to-date devices, show that an overall error below 6% of a chip time can be achieved. PMID:25490585

Local Bifurcations and Optimal Theory in a Delayed Predator-Prey Model with Threshold Prey Harvesting

NASA Astrophysics Data System (ADS)

Tankam, Israel; Tchinda Mouofo, Plaire; Mendy, Abdoulaye; Lam, Mountaga; Tewa, Jean Jules; Bowong, Samuel

2015-06-01

We investigate the effects of time delay and piecewise-linear threshold policy harvesting for a delayed predator-prey model. It is the first time that Holling response function of type III and the present threshold policy harvesting are associated with time delay. The trajectories of our delayed system are bounded; the stability of each equilibrium is analyzed with and without delay; there are local bifurcations as saddle-node bifurcation and Hopf bifurcation; optimal harvesting is also investigated. Numerical simulations are provided in order to illustrate each result.

Corrections of stratified tropospheric delays in SAR interferometry: Validation with global atmospheric models

NASA Astrophysics Data System (ADS)

Doin, Marie-Pierre; Lasserre, Cécile; Peltzer, Gilles; Cavalié, Olivier; Doubre, Cécile

2010-05-01

The main limiting factor on the accuracy of Interferometric SAR measurements (InSAR) comes from phase propagation delays through the troposphere. The delay can be divided into a stratified component, which correlates with the topography and often dominates the tropospheric signal, and a turbulent component. We use Global Atmospheric Models (GAM) to estimate the stratified phase delay and delay-elevation ratio at epochs of SAR acquisitions, and compare them to observed phase delay derived from SAR interferograms. Three test areas are selected with different geographic and climatic environments and with large SAR archive available. The Lake Mead, Nevada, USA is covered by 79 ERS1/2 and ENVISAT acquisitions, the Haiyuan Fault area, Gansu, China, by 24 ERS1/2 acquisitions, and the Afar region, Republic of Djibouti, by 91 Radarsat acquisitions. The hydrostatic and wet stratified delays are computed from GAM as a function of atmospheric pressure P, temperature T, and water vapor partial pressure e vertical profiles. The hydrostatic delay, which depends on ratio P/T, varies significantly at low elevation and cannot be neglected. The wet component of the delay depends mostly on the near surface specific humidity. GAM predicted delay-elevation ratios are in good agreement with the ratios derived from InSAR data away from deforming zones. Both estimations of the delay-elevation ratio can thus be used to perform a first order correction of the observed interferometric phase to retrieve a ground motion signal of low amplitude. We also demonstrate that aliasing of daily and seasonal variations in the stratified delay due to uneven sampling of SAR data significantly bias InSAR data stacks or time series produced after temporal smoothing. In all three test cases, the InSAR data stacks or smoothed time series present a residual stratified delay of the order of the expected deformation signal. In all cases, correcting interferograms from the stratified delay removes all these biases. We quantify the standard error associated with the correction of the stratified atmospheric delay. It varies from one site to another depending on the prevailing atmospheric conditions, but remains bounded by the standard deviation of the daily fluctuations of the stratified delay around the seasonal average. Finally we suggest that the phase delay correction can potentially be improved by introducing a non-linear dependence to the elevation derived from GAM.

Corrections of stratified tropospheric delays in SAR interferometry: Validation with global atmospheric models

NASA Astrophysics Data System (ADS)

Doin, M.-P.; Lasserre, C.; Peltzer, G.; Cavalié, O.; Doubre, C.

2009-09-01

The main limiting factor on the accuracy of Interferometric SAR measurements (InSAR) comes from phase propagation delays through the troposphere. The delay can be divided into a stratified component, which correlates with the topography and often dominates the tropospheric signal, and a turbulent component. We use Global Atmospheric Models (GAM) to estimate the stratified phase delay and delay-elevation ratio at epochs of SAR acquisitions, and compare them to observed phase delay derived from SAR interferograms. Three test areas are selected with different geographic and climatic environments and with large SAR archive available. The Lake Mead, Nevada, USA is covered by 79 ERS1/2 and ENVISAT acquisitions, the Haiyuan Fault area, Gansu, China, by 24 ERS1/2 acquisitions, and the Afar region, Republic of Djibouti, by 91 Radarsat acquisitions. The hydrostatic and wet stratified delays are computed from GAM as a function of atmospheric pressure P, temperature T, and water vapor partial pressure e vertical profiles. The hydrostatic delay, which depends on ratio P/ T, varies significantly at low elevation and cannot be neglected. The wet component of the delay depends mostly on the near surface specific humidity. GAM predicted delay-elevation ratios are in good agreement with the ratios derived from InSAR data away from deforming zones. Both estimations of the delay-elevation ratio can thus be used to perform a first order correction of the observed interferometric phase to retrieve a ground motion signal of low amplitude. We also demonstrate that aliasing of daily and seasonal variations in the stratified delay due to uneven sampling of SAR data significantly bias InSAR data stacks or time series produced after temporal smoothing. In all three test cases, the InSAR data stacks or smoothed time series present a residual stratified delay of the order of the expected deformation signal. In all cases, correcting interferograms from the stratified delay removes all these biases. We quantify the standard error associated with the correction of the stratified atmospheric delay. It varies from one site to another depending on the prevailing atmospheric conditions, but remains bounded by the standard deviation of the daily fluctuations of the stratified delay around the seasonal average. Finally we suggest that the phase delay correction can potentially be improved by introducing a non-linear dependence to the elevation derived from GAM.

Focusing Your E-Recruitment Efforts to Meet the Expectations of College-Bound Students. E-Expectations 2010

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2010

2010-01-01

Early in 2010, the E-Expectations research group surveyed more than 1,000 college-bound high school students, polling them on their online behaviors and expectations, as well as other key enrollment-related topics. Highlights of the study include: (1) 1 in 4 students reported removing a school from their prospective list because of a bad…

Call Admission Control on Single Node Networks under Output Rate-Controlled Generalized Processor Sharing (ORC-GPS) Scheduler

NASA Astrophysics Data System (ADS)

Hanada, Masaki; Nakazato, Hidenori; Watanabe, Hitoshi

Multimedia applications such as music or video streaming, video teleconferencing and IP telephony are flourishing in packet-switched networks. Applications that generate such real-time data can have very diverse quality-of-service (QoS) requirements. In order to guarantee diverse QoS requirements, the combined use of a packet scheduling algorithm based on Generalized Processor Sharing (GPS) and leaky bucket traffic regulator is the most successful QoS mechanism. GPS can provide a minimum guaranteed service rate for each session and tight delay bounds for leaky bucket constrained sessions. However, the delay bounds for leaky bucket constrained sessions under GPS are unnecessarily large because each session is served according to its associated constant weight until the session buffer is empty. In order to solve this problem, a scheduling policy called Output Rate-Controlled Generalized Processor Sharing (ORC-GPS) was proposed in [17]. ORC-GPS is a rate-based scheduling like GPS, and controls the service rate in order to lower the delay bounds for leaky bucket constrained sessions. In this paper, we propose a call admission control (CAC) algorithm for ORC-GPS, for leaky-bucket constrained sessions with deterministic delay requirements. This CAC algorithm for ORC-GPS determines the optimal values of parameters of ORC-GPS from the deterministic delay requirements of the sessions. In numerical experiments, we compare the CAC algorithm for ORC-GPS with one for GPS in terms of schedulable region and computational complexity.

Aspiration, Expectation, and Parental Influences among Upward Bound Students in Three Institutions.

ERIC Educational Resources Information Center

Mims, George L.

1985-01-01

The purpose of this study was to investigate aspiration, expectation, and parental influence and the extent to which these variables manifest themselves among 210 Upward Bound students in three institutions. (Author/LMO)

Minimum expected delay-based routing protocol (MEDR) for Delay Tolerant Mobile Sensor Networks.

PubMed

Feng, Yong; Liu, Ming; Wang, Xiaomin; Gong, Haigang

2010-01-01

It is a challenging work to develop efficient routing protocols for Delay Tolerant Mobile Sensor Networks (DTMSNs), which have several unique characteristics such as sensor mobility, intermittent connectivity, energy limit, and delay tolerability. In this paper, we propose a new routing protocol called Minimum Expected Delay-based Routing (MEDR) tailored for DTMSNs. MEDR achieves a good routing performance by finding and using the connected paths formed dynamically by mobile sensors. In MEDR, each sensor maintains two important parameters: Minimum Expected Delay (MED) and its expiration time. According to MED, messages will be delivered to the sensor that has at least a connected path with their hosting nodes, and has the shortest expected delay to communication directly with the sink node. Because of the changing network topology, the path is fragile and volatile, so we use the expiration time of MED to indicate the valid time of the path, and avoid wrong transmissions. Simulation results show that the proposed MEDR achieves a higher message delivery ratio with lower transmission overhead and data delivery delay than other DTMSN routing approaches.

Finite-time H∞ control for a class of discrete-time switched time-delay systems with quantized feedback

NASA Astrophysics Data System (ADS)

Song, Haiyu; Yu, Li; Zhang, Dan; Zhang, Wen-An

2012-12-01

This paper is concerned with the finite-time quantized H∞ control problem for a class of discrete-time switched time-delay systems with time-varying exogenous disturbances. By using the sector bound approach and the average dwell time method, sufficient conditions are derived for the switched system to be finite-time bounded and ensure a prescribed H∞ disturbance attenuation level, and a mode-dependent quantized state feedback controller is designed by solving an optimization problem. Two illustrative examples are provided to demonstrate the effectiveness of the proposed theoretical results.

Expectancy of an open-book test decreases performance on a delayed closed-book test.

PubMed

Agarwal, Pooja K; Roediger, Henry L

2011-11-01

Two experiments examined the influence of practice with, and the expectancy of, open-book tests (students viewed studied material while taking the test) versus closed-book tests (students completed the test without viewing the studied material) on delayed retention and transfer. Using GRE materials specifically designed for open-book testing, participants studied passages and then took initial open- or closed-book tests. Open-book testing led to better initial performance than closed-book testing, but on a delayed criterial (closed-book) test both types of testing produced similar retention after a two-day delay in Experiment 1. In Experiment 2 participants were informed in advance about the type of delayed criterial test to expect (open- or closed-book). Expecting an open-book test (relative to a closed-book test) decreased participants' time spent studying and their delayed test performance on closed-book comprehension and transfer tests, demonstrating that test expectancy can influence long-term learning. Expectancy of open-book tests may impair long-term retention and transfer compared to closed-book tests, despite superior initial performance on open-book tests and students' preference for open-book tests.

Approximate controllability of a system of parabolic equations with delay

NASA Astrophysics Data System (ADS)

Carrasco, Alexander; Leiva, Hugo

2008-09-01

In this paper we give necessary and sufficient conditions for the approximate controllability of the following system of parabolic equations with delay: where [Omega] is a bounded domain in , D is an n×n nondiagonal matrix whose eigenvalues are semi-simple with nonnegative real part, the control and B[set membership, variant]L(U,Z) with , . The standard notation zt(x) defines a function from [-[tau],0] to (with x fixed) by zt(x)(s)=z(t+s,x), -[tau][less-than-or-equals, slant]s[less-than-or-equals, slant]0. Here [tau][greater-or-equal, slanted]0 is the maximum delay, which is supposed to be finite. We assume that the operator is linear and bounded, and [phi]0[set membership, variant]Z, [phi][set membership, variant]L2([-[tau],0];Z). To this end: First, we reformulate this system into a standard first-order delay equation. Secondly, the semigroup associated with the first-order delay equation on an appropriate product space is expressed as a series of strongly continuous semigroups and orthogonal projections related with the eigenvalues of the Laplacian operator (); this representation allows us to reduce the controllability of this partial differential equation with delay to a family of ordinary delay equations. Finally, we use the well-known result on the rank condition for the approximate controllability of delay system to derive our main result.

Robust stability of interval bidirectional associative memory neural network with time delays.

PubMed

Liao, Xiaofeng; Wong, Kwok-wo

2004-04-01

In this paper, the conventional bidirectional associative memory (BAM) neural network with signal transmission delay is intervalized in order to study the bounded effect of deviations in network parameters and external perturbations. The resultant model is referred to as a novel interval dynamic BAM (IDBAM) model. By combining a number of different Lyapunov functionals with the Razumikhin technique, some sufficient conditions for the existence of unique equilibrium and robust stability are derived. These results are fairly general and can be verified easily. To go further, we extend our investigation to the time-varying delay case. Some robust stability criteria for BAM with perturbations of time-varying delays are derived. Besides, our approach for the analysis allows us to consider several different types of activation functions, including piecewise linear sigmoids with bounded activations as well as the usual C1-smooth sigmoids. We believe that the results obtained have leading significance in the design and application of BAM neural networks.

The Online Expectations of College-Bound Juniors and Seniors. E-Expectations Report, 2012

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2012

2012-01-01

Noel-Levitz, OmniUpdate, CollegeWeekLive, and NRCCUA[R] (National Research Center for College & University Admissions) conducted a survey of 2,000 college-bound juniors and seniors about their expectations for college Web sites, mobile usage, e-mail, and social media. Among the findings: (1) More than 50 percent of students said the Web played a…

Expected Time of Test and the Acquisition of Knowledge.

ERIC Educational Resources Information Center

D'Ydewalle, G.; And Others

1981-01-01

Subjects from four physics or literature classes expected a delayed or an immediate test after their class. All were tested immediately. Male subjects expecting the immediate test performed better than males expecting a delayed test. Absence of interaction effects with personality measurement suggested the inadequacy of the goal gradient…

Approaching system equilibrium with accurate or not accurate feedback information in a two-route system

NASA Astrophysics Data System (ADS)

Zhao, Xiao-mei; Xie, Dong-fan; Li, Qi

2015-02-01

With the development of intelligent transport system, advanced information feedback strategies have been developed to reduce traffic congestion and enhance the capacity. However, previous strategies provide accurate information to travelers and our simulation results show that accurate information brings negative effects, especially in delay case. Because travelers prefer to the best condition route with accurate information, and delayed information cannot reflect current traffic condition but past. Then travelers make wrong routing decisions, causing the decrease of the capacity and the increase of oscillations and the system deviating from the equilibrium. To avoid the negative effect, bounded rationality is taken into account by introducing a boundedly rational threshold BR. When difference between two routes is less than the BR, routes have equal probability to be chosen. The bounded rationality is helpful to improve the efficiency in terms of capacity, oscillation and the gap deviating from the system equilibrium.

Constraints on Born-Infeld gravity from the speed of gravitational waves after GW170817 and GRB 170817A

NASA Astrophysics Data System (ADS)

Jana, Soumya; Chakravarty, Girish Kumar; Mohanty, Subhendra

2018-04-01

The observations of gravitational waves from the binary neutron star merger event GW170817 and the subsequent observation of its electromagnetic counterparts from the gamma-ray burst GRB 170817A provide us a significant opportunity to study theories of gravity beyond general relativity. An important outcome of these observations is that they constrain the difference between the speed of gravity and the speed of light to less than 10-15c . Also, the time delay between the arrivals of gravitational waves at different detectors constrains the speed of gravity at the Earth to be in the range 0.55 c

Delay-slope-dependent stability results of recurrent neural networks.

PubMed

Li, Tao; Zheng, Wei Xing; Lin, Chong

2011-12-01

By using the fact that the neuron activation functions are sector bounded and nondecreasing, this brief presents a new method, named the delay-slope-dependent method, for stability analysis of a class of recurrent neural networks with time-varying delays. This method includes more information on the slope of neuron activation functions and fewer matrix variables in the constructed Lyapunov-Krasovskii functional. Then some improved delay-dependent stability criteria with less computational burden and conservatism are obtained. Numerical examples are given to illustrate the effectiveness and the benefits of the proposed method.

Finite-time robust stabilization of uncertain delayed neural networks with discontinuous activations via delayed feedback control.

PubMed

Wang, Leimin; Shen, Yi; Sheng, Yin

2016-04-01

This paper is concerned with the finite-time robust stabilization of delayed neural networks (DNNs) in the presence of discontinuous activations and parameter uncertainties. By using the nonsmooth analysis and control theory, a delayed controller is designed to realize the finite-time robust stabilization of DNNs with discontinuous activations and parameter uncertainties, and the upper bound of the settling time functional for stabilization is estimated. Finally, two examples are provided to demonstrate the effectiveness of the theoretical results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stability of uncertain impulsive complex-variable chaotic systems with time-varying delays.

PubMed

Zheng, Song

2015-09-01

In this paper, the robust exponential stabilization of uncertain impulsive complex-variable chaotic delayed systems is considered with parameters perturbation and delayed impulses. It is assumed that the considered complex-variable chaotic systems have bounded parametric uncertainties together with the state variables on the impulses related to the time-varying delays. Based on the theories of adaptive control and impulsive control, some less conservative and easily verified stability criteria are established for a class of complex-variable chaotic delayed systems with delayed impulses. Some numerical simulations are given to validate the effectiveness of the proposed criteria of impulsive stabilization for uncertain complex-variable chaotic delayed systems. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

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

NASA Astrophysics Data System (ADS)

Arik, Sabri

2006-02-01

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

Northwest Laboratory for Integrated Systems, University of Washington, Semiannual Technical Report Number 1, July 1-November 8, 1991

DTIC Science & Technology

1991-11-08

only simple bounds on delays but also relate the delays in linear inequalities so that tradeoffs are apparent. We model circuits as communicating...set of linear inequalities constraining the variables. These relations provide synthesis tools with information about tradeoffs between circuit delays...available to express the original circuit as a graph of elementary gates and then cover the graph’s fanout-free trees with collections of three-input

Autapse-induced multiple stochastic resonances in a modular neuronal network

NASA Astrophysics Data System (ADS)

Yang, XiaoLi; Yu, YanHu; Sun, ZhongKui

2017-08-01

This study investigates the nontrivial effects of autapse on stochastic resonance in a modular neuronal network subjected to bounded noise. The resonance effect of autapse is detected by imposing a self-feedback loop with autaptic strength and autaptic time delay to each constituent neuron. Numerical simulations have demonstrated that bounded noise with the proper level of amplitude can induce stochastic resonance; moreover, the noise induced resonance dynamics can be significantly shaped by the autapse. In detail, for a specific range of autaptic strength, multiple stochastic resonances can be induced when the autaptic time delays are appropriately adjusted. These appropriately adjusted delays are detected to nearly approach integer multiples of the period of the external weak signal when the autaptic strength is very near zero; otherwise, they do not match the period of the external weak signal when the autaptic strength is slightly greater than zero. Surprisingly, in both cases, the differences between arbitrary two adjacent adjusted autaptic delays are always approximately equal to the period of the weak signal. The phenomenon of autaptic delay induced multiple stochastic resonances is further confirmed to be robust against the period of the external weak signal and the intramodule probability of subnetwork. These findings could have important implications for weak signal detection and information propagation in realistic neural systems.

Bounds on invisible Higgs boson decays extracted from LHC ttH production data.

PubMed

Zhou, Ning; Khechadoorian, Zepyoor; Whiteson, Daniel; Tait, Tim M P

2014-10-10

We present an upper bound on the branching fraction of the Higgs boson to invisible particles by recasting a CMS Collaboration search for stop quarks decaying to tt + E(T)(miss). The observed (expected) bound, BF(H → inv.) < 0.40(0.65) at 95% C.L., is the strongest direct limit to date, benefiting from a downward fluctuation in the CMS data in that channel. In addition, we combine this new constraint with existing published constraints to give an observed (expected) bound of BF(H → inv.) < 0.40(0.40) at 95% C.L., and we show some of the implications for theories of dark matter which communicate through the Higgs portal.

Global robust stability of bidirectional associative memory neural networks with multiple time delays.

PubMed

Senan, Sibel; Arik, Sabri

2007-10-01

This correspondence presents a sufficient condition for the existence, uniqueness, and global robust asymptotic stability of the equilibrium point for bidirectional associative memory neural networks with discrete time delays. The results impose constraint conditions on the network parameters of the neural system independently of the delay parameter, and they are applicable to all bounded continuous nonmonotonic neuron activation functions. Some numerical examples are given to compare our results with the previous robust stability results derived in the literature.

Scrolling toward Enrollment: Web Site Content and the E-Expectations of College-Bound Seniors. E-Expectations

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2009

2009-01-01

Communicating with prospective students has undergone a profound transformation in the past ten years. Campus marketing--like marketing for any organization--had to adapt first to the Internet and e-mail and now to new social media formats like social networking and blogging. A recent survey of 1,000 college-bound seniors, however, shows that…

Robust reliable sampled-data control for switched systems with application to flight control

NASA Astrophysics Data System (ADS)

Sakthivel, R.; Joby, Maya; Shi, P.; Mathiyalagan, K.

2016-11-01

This paper addresses the robust reliable stabilisation problem for a class of uncertain switched systems with random delays and norm bounded uncertainties. The main aim of this paper is to obtain the reliable robust sampled-data control design which involves random time delay with an appropriate gain control matrix for achieving the robust exponential stabilisation for uncertain switched system against actuator failures. In particular, the involved delays are assumed to be randomly time-varying which obeys certain mutually uncorrelated Bernoulli distributed white noise sequences. By constructing an appropriate Lyapunov-Krasovskii functional (LKF) and employing an average-dwell time approach, a new set of criteria is derived for ensuring the robust exponential stability of the closed-loop switched system. More precisely, the Schur complement and Jensen's integral inequality are used in derivation of stabilisation criteria. By considering the relationship among the random time-varying delay and its lower and upper bounds, a new set of sufficient condition is established for the existence of reliable robust sampled-data control in terms of solution to linear matrix inequalities (LMIs). Finally, an illustrative example based on the F-18 aircraft model is provided to show the effectiveness of the proposed design procedures.

Entropy bounds in terms of the w parameter

NASA Astrophysics Data System (ADS)

Abreu, Gabriel; Barceló, Carlos; Visser, Matt

2011-12-01

In a pair of recent articles [PRL 105 (2010) 041302; JHEP 1103 (2011) 056] two of the current authors have developed an entropy bound for equilibrium uncollapsed matter using only classical general relativity, basic thermodynamics, and the Unruh effect. An odd feature of that bound, [InlineMediaObject not available: see fulltext.], was that the proportionality constant, 1/2 , was weaker than that expected from black hole thermodynamics, 1/4 . In the current article we strengthen the previous results by obtaining a bound involving the (suitably averaged) w parameter. Simple causality arguments restrict this averaged < w> parameter to be ≤ 1. When equality holds, the entropy bound saturates at the value expected based on black hole thermodynamics. We also add some clarifying comments regarding the (net) positivity of the chemical potential. Overall, we find that even in the absence of any black hole region, we can nevertheless get arbitrarily close to the Bekenstein entropy.

Both trace and delay conditioned eyeblink responding can be dissociated from outcome expectancy.

PubMed

Weidemann, Gabrielle; Broderick, Joshua; Lovibond, Peter F; Mitchell, Christopher J

2012-01-01

Squire and colleagues have proposed that trace and delay eyeblink conditioning are fundamentally different kinds of learning: trace conditioning requires acquisition of a conscious declarative memory for the stimulus contingencies whereas delay conditioning does not. Declarative memory in trace conditioning is thought to generate conditioned responding through the activation of a conscious expectancy for when the unconditioned stimulus (US) is going to occur. Perruchet (1985) has previously shown that in a 50% partial reinforcement design it is possible to dissociate single cue delay eyeblink conditioning from conscious expectancy for the US by examining performance over runs of reinforced and nonreinforced trials. Clark, Manns, and Squire (2001) claim that this dissociation does not occur in trace eyeblink conditioning. In the present experiment we examined the Perruchet effect for short, moderate, and long trace intervals (600, 1000, and 1400 ms) and for the equivalent interstimulus intervals (ISIs) in a delay conditioning procedure. We found evidence for a dissociation of eyeblink CRs and US expectancy over runs regardless of whether there was a delay or a trace arrangement of cues. The reasons for the Perruchet effect are still unclear, but the present data suggest that it does not depend on a separate nondeclarative system of the type proposed by Squire and colleagues. (c) 2012 APA, all rights reserved.

Risk aversion and risk seeking in multicriteria forest management: a Markov decision process approach

Treesearch

Joseph Buongiorno; Mo Zhou; Craig Johnston

2017-01-01

Markov decision process models were extended to reflect some consequences of the risk attitude of forestry decision makers. One approach consisted of maximizing the expected value of a criterion subject to an upper bound on the variance or, symmetrically, minimizing the variance subject to a lower bound on the expected value.  The other method used the certainty...

NYU Ada/Ed User’s Guide - Version 1.4 for VAX/VMS Systems.

DTIC Science & Technology

1984-07-01

Executble fie).M h le contains the Intermediate code from the alajie, bound togethr with the scomsary compilaton units bum libaries rquested by the pmn...3.5.4 bounds in -n integer type definition must be of sme intge type 3.5.7 Expect static expression for digits 3.5.7 Expect integer expression for...DI&13 3.5.7 Invalid digits value in real type dedwaation 3.5.7 Expect static expression for delta 3.5.9 Expression for delta must be of some real type

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

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

Gupta, Chinmaya; López, José Manuel; Azencott, Robert

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

Long-term consolidation of declarative memory: insight from temporal lobe epilepsy.

PubMed

Tramoni, Eve; Felician, Olivier; Barbeau, Emmanuel J; Guedj, Eric; Guye, Maxime; Bartolomei, Fabrice; Ceccaldi, Mathieu

2011-03-01

Several experiments carried out with a subset of patients with temporal lobe epilepsy have demonstrated normal memory performance at standard delays of recall (i.e. minutes to hours) but impaired performance over longer delays (i.e. days or weeks), suggesting altered long-term consolidation mechanisms. These mechanisms were specifically investigated in a group of five adult-onset pharmaco-sensitive patients with temporal lobe epilepsy, exhibiting severe episodic memory complaints despite normal performance at standardized memory assessment. In a first experiment, the magnitude of autobiographical memory loss was evaluated using retrograde personal memory tasks based on verbal and visual cues. In both conditions, results showed an unusual U-shaped pattern of personal memory impairment, encompassing most of the patients' life, sparing however, periods of the childhood, early adulthood and past several weeks. This profile was suggestive of a long-term consolidation impairment of personal episodes, adequately consolidated over 'short-term' delays but gradually forgotten thereafter. Therefore, in a subsequent experiment, patients were submitted to a protocol specifically devised to investigate short and long-term consolidation of contextually-bound experiences (episodic memory) and context-free information (semantic knowledge and single-items). In the short term (1 h), performance at both contextually-free and contextually-bound memory tasks was intact. After a 6-week delay, however, contextually-bound memory performance was impaired while contextually-free memory performance remained preserved. This effect was independent of task difficulty and the modality of retrieval (recall and recognition). Neuroimaging studies revealed the presence of mild metabolic changes within medial temporal lobe structures. Taken together, these results show the existence of different consolidation systems within declarative memory. They suggest that mild medial temporal lobe dysfunction can impede the building and stabilization of episodic memories but leaves long-term semantic and single-items mnemonic traces intact.

Molecular alignment effect on the photoassociation process via a pump-dump scheme.

PubMed

Wang, Bin-Bin; Han, Yong-Chang; Cong, Shu-Lin

2015-09-07

The photoassociation processes via the pump-dump scheme for the heternuclear (Na + H → NaH) and the homonuclear (Na + Na → Na2) molecular systems are studied, respectively, using the time-dependent quantum wavepacket method. For both systems, the initial atom pair in the continuum of the ground electronic state (X(1)Σ(+)) is associated into the molecule in the bound states of the excited state (A(1)Σ(+)) by the pump pulse. Then driven by a time-delayed dumping pulse, the prepared excited-state molecule can be transferred to the bound states of the ground electronic state. It is found that the pump process can induce a superposition of the rovibrational levels |v, j〉 on the excited state, which can lead to the field-free alignment of the excited-state molecule. The molecular alignment can affect the dumping process by varying the effective coupling intensity between the two electronic states or by varying the population transfer pathways. As a result, the final population transferred to the bound states of the ground electronic state varies periodically with the delay time of the dumping pulse.

Molecular alignment effect on the photoassociation process via a pump-dump scheme

NASA Astrophysics Data System (ADS)

Wang, Bin-Bin; Han, Yong-Chang; Cong, Shu-Lin

2015-09-01

The photoassociation processes via the pump-dump scheme for the heternuclear (Na + H → NaH) and the homonuclear (Na + Na → Na2) molecular systems are studied, respectively, using the time-dependent quantum wavepacket method. For both systems, the initial atom pair in the continuum of the ground electronic state (X1Σ+) is associated into the molecule in the bound states of the excited state (A1Σ+) by the pump pulse. Then driven by a time-delayed dumping pulse, the prepared excited-state molecule can be transferred to the bound states of the ground electronic state. It is found that the pump process can induce a superposition of the rovibrational levels |v, j> on the excited state, which can lead to the field-free alignment of the excited-state molecule. The molecular alignment can affect the dumping process by varying the effective coupling intensity between the two electronic states or by varying the population transfer pathways. As a result, the final population transferred to the bound states of the ground electronic state varies periodically with the delay time of the dumping pulse.

Delay Analysis and Optimization of Bandwidth Request under Unicast Polling in IEEE 802.16e over Gilbert-Elliot Error Channel

NASA Astrophysics Data System (ADS)

Hwang, Eunju; Kim, Kyung Jae; Roijers, Frank; Choi, Bong Dae

In the centralized polling mode in IEEE 802.16e, a base station (BS) polls mobile stations (MSs) for bandwidth reservation in one of three polling modes; unicast, multicast, or broadcast pollings. In unicast polling, the BS polls each individual MS to allow to transmit a bandwidth request packet. This paper presents an analytical model for the unicast polling of bandwidth request in IEEE 802.16e networks over Gilbert-Elliot error channel. We derive the probability distribution for the delay of bandwidth requests due to wireless transmission errors and find the loss probability of request packets due to finite retransmission attempts. By using the delay distribution and the loss probability, we optimize the number of polling slots within a frame and the maximum retransmission number while satisfying QoS on the total loss probability which combines two losses: packet loss due to the excess of maximum retransmission and delay outage loss due to the maximum tolerable delay bound. In addition, we obtain the utilization of polling slots, which is defined as the ratio of the number of polling slots used for the MS's successful transmission to the total number of polling slots used by the MS over a long run time. Analysis results are shown to well match with simulation results. Numerical results give examples of the optimal number of polling slots within a frame and the optimal maximum retransmission number depending on delay bounds, the number of MSs, and the channel conditions.

Experimental evidence for bounds on quantum correlations.

PubMed

Bovino, F A; Castagnoli, G; Degiovanni, I P; Castelletto, S

2004-02-13

We implemented the experiment proposed by Cabello in the preceding Letter to test the bounds of quantum correlation. As expected from the theory we found that, for certain choices of local observables, Tsirelson's bound of the Clauser-Horne-Shimony-Holt inequality (2 x square root of 2) is not reached by any quantum states.

Vehicle following controller design for autonomous intelligent vehicles

NASA Technical Reports Server (NTRS)

Chien, C. C.; Lai, M. C.; Mayr, R.

1994-01-01

A new vehicle following controller is proposed for autonomous intelligent vehicles. The proposed vehicle following controller not only provides smooth transient maneuvers for unavoidable nonzero initial conditions but also guarantees the asymptotic platoon stability without the availability of feedforward information. Furthermore, the achieved asymptotic platoon stability is shown to be robust to sensor delays and an upper bound for the allowable sensor delays is also provided in this paper.

Complex word reading in Dutch deaf children and adults.

PubMed

van Hoogmoed, Anne H; Knoors, Harry; Schreuder, Robert; Verhoeven, Ludo

2013-03-01

Children who are deaf are often delayed in reading comprehension. This delay could be due to problems in morphological processing during word reading. In this study, we investigated whether 6th grade deaf children and adults are delayed in comparison to their hearing peers in reading complex derivational words and compounds compared to monomorphemic words. The results show that deaf children are delayed in reading both derivational words and compounds as compared to hearing children, while both deaf and hearing adults performed equally well on a lexical decision task. However, deaf adults generally showed slower reaction times than hearing adults. For both deaf and hearing children, derivational words were more difficult than compounds, as reflected in hearing children's slower reaction times and in deaf children's lower accuracy scores. This finding likely reflects deaf children's lack of familiarity with the meaning of the bound morphemes attached to the stems in derivational words. Therefore, it might be beneficial to teach deaf children the meaning of bound morphemes and to train them to use morphology in word reading. Moreover, these findings imply that it is important to focus on both monomorphemic and polymorphemic words when assessing word reading ability in deaf children. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dual-user nonlinear teleoperation subjected to varying time delay and bounded inputs.

PubMed

Zakerimanesh, Amir; Hashemzadeh, Farzad; Ghiasi, Amir Rikhtehgar

2017-05-01

A novel trilateral control architecture for Dual-master/Single-slave teleoperation system with taking account of saturation in actuators, nonlinear dynamics for telemanipulators and bounded varying time delay which affects the transmitted signals in the communication channels, is proposed in this paper. In this research, we will address the stability and desired position coordination problem of trilateral teleoperation system by extension of (nP+D) controller that is used for Single-master/Single-slave teleoperation system. Our proposed controller is weighted summation of nonlinear Proportional plus Damping (nP+D) controller that incorporate gravity compensation and the weights are specified by the dominance factor, which determines the supremacy of each user over the slave robot and over the other user. The asymptotic stability of closed loop dynamics is studied using Lyapunov-Krasovskii functional under conditions on the controller parameters, the actuator saturation characteristics and the maximum values of varying time delays. It is shown that these controllers satisfy the desired position coordination problem in free motion condition. To show the effectiveness of the proposed method, a number of simulations have been conducted on a varying time delay Dual-master/Single-slave teleoperation system using 3-DOF planar robots for each telemanipulator subjected to actuator saturation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Time and outcome framing in intertemporal tradeoffs.

PubMed

Scholten, Marc; Read, Daniel

2013-07-01

A robust anomaly in intertemporal choice is the delay-speedup asymmetry: Receipts are discounted more, and payments are discounted less, when delayed than when expedited over the same interval. We developed 2 versions of the tradeoff model (Scholten & Read, 2010) to address such situations, in which an outcome is expected at a given time but then its timing is changed. The outcome framing model generalizes the approach taken by the hyperbolic discounting model (Loewenstein & Prelec, 1992): Not obtaining a positive outcome when expected is a worse than expected state, to which people are over-responsive, or hypersensitive, and not incurring a negative outcome when expected is a better than expected state, to which people are under-responsive, or hyposensitive. The time framing model takes a new approach: Delaying a positive outcome or speeding up a negative one involves a loss of time to which people are hypersensitive, and speeding up a positive outcome or delaying a negative one involves a gain of time to which people are hyposensitive. We compare the models on their quantitative predictions of indifference data from matching and preference data from choice. The time framing model systematically outperforms the outcome framing model. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Cluster-Based Maximum Consensus Time Synchronization for Industrial Wireless Sensor Networks.

PubMed

Wang, Zhaowei; Zeng, Peng; Zhou, Mingtuo; Li, Dong; Wang, Jintao

2017-01-13

Time synchronization is one of the key technologies in Industrial Wireless Sensor Networks (IWSNs), and clustering is widely used in WSNs for data fusion and information collection to reduce redundant data and communication overhead. Considering IWSNs' demand for low energy consumption, fast convergence, and robustness, this paper presents a novel Cluster-based Maximum consensus Time Synchronization (CMTS) method. It consists of two parts: intra-cluster time synchronization and inter-cluster time synchronization. Based on the theory of distributed consensus, the proposed method utilizes the maximum consensus approach to realize the intra-cluster time synchronization, and adjacent clusters exchange the time messages via overlapping nodes to synchronize with each other. A Revised-CMTS is further proposed to counteract the impact of bounded communication delays between two connected nodes, because the traditional stochastic models of the communication delays would distort in a dynamic environment. The simulation results show that our method reduces the communication overhead and improves the convergence rate in comparison to existing works, as well as adapting to the uncertain bounded communication delays.

Cluster-Based Maximum Consensus Time Synchronization for Industrial Wireless Sensor Networks †

PubMed Central

Wang, Zhaowei; Zeng, Peng; Zhou, Mingtuo; Li, Dong; Wang, Jintao

2017-01-01

Time synchronization is one of the key technologies in Industrial Wireless Sensor Networks (IWSNs), and clustering is widely used in WSNs for data fusion and information collection to reduce redundant data and communication overhead. Considering IWSNs’ demand for low energy consumption, fast convergence, and robustness, this paper presents a novel Cluster-based Maximum consensus Time Synchronization (CMTS) method. It consists of two parts: intra-cluster time synchronization and inter-cluster time synchronization. Based on the theory of distributed consensus, the proposed method utilizes the maximum consensus approach to realize the intra-cluster time synchronization, and adjacent clusters exchange the time messages via overlapping nodes to synchronize with each other. A Revised-CMTS is further proposed to counteract the impact of bounded communication delays between two connected nodes, because the traditional stochastic models of the communication delays would distort in a dynamic environment. The simulation results show that our method reduces the communication overhead and improves the convergence rate in comparison to existing works, as well as adapting to the uncertain bounded communication delays. PMID:28098750

A Novel Finite-Sum Inequality-Based Method for Robust H∞ Control of Uncertain Discrete-Time Takagi-Sugeno Fuzzy Systems With Interval-Like Time-Varying Delays.

PubMed

Zhang, Xian-Ming; Han, Qing-Long; Ge, Xiaohua

2017-09-22

This paper is concerned with the problem of robust H∞ control of an uncertain discrete-time Takagi-Sugeno fuzzy system with an interval-like time-varying delay. A novel finite-sum inequality-based method is proposed to provide a tighter estimation on the forward difference of certain Lyapunov functional, leading to a less conservative result. First, an auxiliary vector function is used to establish two finite-sum inequalities, which can produce tighter bounds for the finite-sum terms appearing in the forward difference of the Lyapunov functional. Second, a matrix-based quadratic convex approach is employed to equivalently convert the original matrix inequality including a quadratic polynomial on the time-varying delay into two boundary matrix inequalities, which delivers a less conservative bounded real lemma (BRL) for the resultant closed-loop system. Third, based on the BRL, a novel sufficient condition on the existence of suitable robust H∞ fuzzy controllers is derived. Finally, two numerical examples and a computer-simulated truck-trailer system are provided to show the effectiveness of the obtained results.

Synchronization error estimation and controller design for delayed Lur'e systems with parameter mismatches.

PubMed

He, Wangli; Qian, Feng; Han, Qing-Long; Cao, Jinde

2012-10-01

This paper investigates the problem of master-slave synchronization of two delayed Lur'e systems in the presence of parameter mismatches. First, by analyzing the corresponding synchronization error system, synchronization with an error level, which is referred to as quasi-synchronization, is established. Some delay-dependent quasi-synchronization criteria are derived. An estimation of the synchronization error bound is given, and an explicit expression of error levels is obtained. Second, sufficient conditions on the existence of feedback controllers under a predetermined error level are provided. The controller gains are obtained by solving a set of linear matrix inequalities. Finally, a delayed Chua's circuit is chosen to illustrate the effectiveness of the derived results.

Non-predictor control of a class of feedforward nonlinear systems with unknown time-varying delays

NASA Astrophysics Data System (ADS)

Koo, Min-Sung; Choi, Ho-Lim

2016-08-01

This paper generalises the several recent results on the control of feedforward time-delay nonlinear systems. First, in view of system formulation, there are unknown time-varying delays in both states and main control input. Also, the considered nonlinear system has extended feedforward nonlinearities. Second, in view of control solution, our proposed controller is a non-predictor feedback controller whereas smith-predictor type controllers are used in the several existing results. Moreover, our controller does not need any information on the unknown delays except their upper bounds. Thus, our result has certain merits in both system formulation and control solution perspective. The analysis and example are given for clear illustration.

Expected performance of m-solution backtracking

NASA Technical Reports Server (NTRS)

Nicol, D. M.

1986-01-01

This paper derives upper bounds on the expected number of search tree nodes visited during an m-solution backtracking search, a search which terminates after some preselected number m problem solutions are found. The search behavior is assumed to have a general probabilistic structure. The results are stated in terms of node expansion and contraction. A visited search tree node is said to be expanding if the mean number of its children visited by the search exceeds 1 and is contracting otherwise. It is shown that if every node expands, or if every node contracts, then the number of search tree nodes visited by a search has an upper bound which is linear in the depth of the tree, in the mean number of children a node has, and in the number of solutions sought. Also derived are bounds linear in the depth of the tree in some situations where an upper portion of the tree contracts (expands), while the lower portion expands (contracts). While previous analyses of 1-solution backtracking have concluded that the expected performance is always linear in the tree depth, the model allows superlinear expected performance.

Impact of MAC Delay on AUV Localization: Underwater Localization Based on Hyperbolic Frequency Modulation Signal

PubMed Central

2018-01-01

Medium Access Control (MAC) delay which occurs between the anchor node’s transmissions is one of the error sources in underwater localization. In particular, in AUV localization, the MAC delay significantly degrades the ranging accuracy. The Cramer-Rao Low Bound (CRLB) definition theoretically proves that the MAC delay significantly degrades the localization performance. This paper proposes underwater localization combined with multiple access technology to decouple the localization performance from the MAC delay. Towards this goal, we adopt hyperbolic frequency modulation (HFM) signal that provides multiplexing based on its good property, high-temporal correlation. Owing to the multiplexing ability of the HFM signal, the anchor nodes can transmit packets without MAC delay, i.e., simultaneous transmission is possible. In addition, the simulation results show that the simultaneous transmission is not an optional communication scheme, but essential for the localization of mobile object in underwater. PMID:29373518

Impact of MAC Delay on AUV Localization: Underwater Localization Based on Hyperbolic Frequency Modulation Signal.

PubMed

Kim, Sungryul; Yoo, Younghwan

2018-01-26

Medium Access Control (MAC) delay which occurs between the anchor node's transmissions is one of the error sources in underwater localization. In particular, in AUV localization, the MAC delay significantly degrades the ranging accuracy. The Cramer-Rao Low Bound (CRLB) definition theoretically proves that the MAC delay significantly degrades the localization performance. This paper proposes underwater localization combined with multiple access technology to decouple the localization performance from the MAC delay. Towards this goal, we adopt hyperbolic frequency modulation (HFM) signal that provides multiplexing based on its good property, high-temporal correlation. Owing to the multiplexing ability of the HFM signal, the anchor nodes can transmit packets without MAC delay, i.e., simultaneous transmission is possible. In addition, the simulation results show that the simultaneous transmission is not an optional communication scheme, but essential for the localization of mobile object in underwater.

34 CFR 645.14 - What additional services do Veterans Upward Bound projects provide?

Code of Federal Regulations, 2010 CFR

2010-07-01

... basic skills development in those academic subjects required for successful completion of a high school... refresher courses for veterans who are high school graduates but who have delayed pursuing postsecondary...

When, not if: the inescapability of an uncertain climate future.

PubMed

Ballard, Timothy; Lewandowsky, Stephan

2015-11-28

Climate change projections necessarily involve uncertainty. Analysis of the physics and mathematics of the climate system reveals that greater uncertainty about future temperature increases is nearly always associated with greater expected damages from climate change. In contrast to those normative constraints, uncertainty is frequently cited in public discourse as a reason to delay mitigative action. This failure to understand the actual implications of uncertainty may incur notable future costs. It is therefore important to communicate uncertainty in a way that improves people's understanding of climate change risks. We examined whether responses to projections were influenced by whether the projection emphasized uncertainty in the outcome or in its time of arrival. We presented participants with statements and graphs indicating projected increases in temperature, sea levels, ocean acidification and a decrease in arctic sea ice. In the uncertain-outcome condition, statements reported the upper and lower confidence bounds of the projected outcome at a fixed time point. In the uncertain time-of-arrival condition, statements reported the upper and lower confidence bounds of the projected time of arrival for a fixed outcome. Results suggested that people perceived the threat as more serious and were more likely to encourage mitigative action in the time-uncertain condition than in the outcome-uncertain condition. This finding has implications for effectively communicating the climate change risks to policy-makers and the general public. © 2015 The Author(s).

Robust stability for stochastic bidirectional associative memory neural networks with time delays

NASA Astrophysics Data System (ADS)

Shu, H. S.; Lv, Z. W.; Wei, G. L.

2008-02-01

In this paper, the asymptotic stability is considered for a class of uncertain stochastic bidirectional associative memory neural networks with time delays and parameter uncertainties. The delays are time-invariant and the uncertainties are norm-bounded that enter into all network parameters. The aim of this paper is to establish easily verifiable conditions under which the delayed neural network is robustly asymptotically stable in the mean square for all admissible parameter uncertainties. By employing a Lyapunov-Krasovskii functional and conducting the stochastic analysis, a linear matrix inequality matrix inequality (LMI) approach is developed to derive the stability criteria. The proposed criteria can be easily checked by the Matlab LMI toolbox. A numerical example is given to demonstrate the usefulness of the proposed criteria.

Teaching Effectiveness, Course Evaluation, and Academic Performance: The Role of Academic Delay of Gratification

ERIC Educational Resources Information Center

Bembenutty, Hefer

2009-01-01

Academic delay of gratification is a significant and positive predictor of students' final course grades, even after controlling for the effect of their rating of the course, expected grade, and degree of interest, importance, and utility of the academic task. Students' expected course grades are by far the strongest predictor of their final…

A hybrid approach to parameter identification of linear delay differential equations involving multiple delays

NASA Astrophysics Data System (ADS)

Marzban, Hamid Reza

2018-05-01

In this paper, we are concerned with the parameter identification of linear time-invariant systems containing multiple delays. The approach is based upon a hybrid of block-pulse functions and Legendre's polynomials. The convergence of the proposed procedure is established and an upper error bound with respect to the L2-norm associated with the hybrid functions is derived. The problem under consideration is first transformed into a system of algebraic equations. The least squares technique is then employed for identification of the desired parameters. Several multi-delay systems of varying complexity are investigated to evaluate the performance and capability of the proposed approximation method. It is shown that the proposed approach is also applicable to a class of nonlinear multi-delay systems. It is demonstrated that the suggested procedure provides accurate results for the desired parameters.

Observer-based output feedback control of networked control systems with non-uniform sampling and time-varying delay

NASA Astrophysics Data System (ADS)

Meng, Su; Chen, Jie; Sun, Jian

2017-10-01

This paper investigates the problem of observer-based output feedback control for networked control systems with non-uniform sampling and time-varying transmission delay. The sampling intervals are assumed to vary within a given interval. The transmission delay belongs to a known interval. A discrete-time model is first established, which contains time-varying delay and norm-bounded uncertainties coming from non-uniform sampling intervals. It is then converted to an interconnection of two subsystems in which the forward channel is delay-free. The scaled small gain theorem is used to derive the stability condition for the closed-loop system. Moreover, the observer-based output feedback controller design method is proposed by utilising a modified cone complementary linearisation algorithm. Finally, numerical examples illustrate the validity and superiority of the proposed method.

Stability analysis for discrete-time stochastic memristive neural networks with both leakage and probabilistic delays.

PubMed

Liu, Hongjian; Wang, Zidong; Shen, Bo; Huang, Tingwen; Alsaadi, Fuad E

2018-06-01

This paper is concerned with the globally exponential stability problem for a class of discrete-time stochastic memristive neural networks (DSMNNs) with both leakage delays as well as probabilistic time-varying delays. For the probabilistic delays, a sequence of Bernoulli distributed random variables is utilized to determine within which intervals the time-varying delays fall at certain time instant. The sector-bounded activation function is considered in the addressed DSMNN. By taking into account the state-dependent characteristics of the network parameters and choosing an appropriate Lyapunov-Krasovskii functional, some sufficient conditions are established under which the underlying DSMNN is globally exponentially stable in the mean square. The derived conditions are made dependent on both the leakage and the probabilistic delays, and are therefore less conservative than the traditional delay-independent criteria. A simulation example is given to show the effectiveness of the proposed stability criterion. Copyright © 2018 Elsevier Ltd. All rights reserved.

L∞-gain adaptive fuzzy fault accommodation control design for nonlinear time-delay systems.

PubMed

Wu, Huai-Ning; Qiang, Xiao-Hong; Guo, Lei

2011-06-01

In this paper, an adaptive fuzzy fault accommodation (FA) control design with a guaranteed L(∞)-gain performance is developed for a class of nonlinear time-delay systems with persistent bounded disturbances. Using the Lyapunov technique and the Razumikhin-type lemma, the existence condition of the L(∞) -gain adaptive fuzzy FA controllers is provided in terms of linear matrix inequalities (LMIs). In the proposed FA scheme, a fuzzy logic system is employed to approximate the unknown term in the derivative of the Lyapunov function due to the unknown fault function; a continuous-state feedback control strategy is adopted for the control design to avoid the undesirable chattering phenomenon. The resulting FA controllers can ensure that every response of the closed-loop system is uniformly ultimately bounded with a guaranteed L(∞)-gain performance in the presence of a fault. Moreover, by the existing LMI optimization technique, a suboptimal controller is obtained in the sense of minimizing an upper bound of the L(∞)-gain. Finally, the achieved simulation results on the FA control of a continuous stirred tank reactor (CSTR) show the effectiveness of the proposed design procedure.

Molecular alignment effect on the photoassociation process via a pump-dump scheme

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

Wang, Bin-Bin; Han, Yong-Chang, E-mail: ychan@dlut.edu.cn; Cong, Shu-Lin

The photoassociation processes via the pump-dump scheme for the heternuclear (Na + H → NaH) and the homonuclear (Na + Na → Na{sub 2}) molecular systems are studied, respectively, using the time-dependent quantum wavepacket method. For both systems, the initial atom pair in the continuum of the ground electronic state (X{sup 1}Σ{sup +}) is associated into the molecule in the bound states of the excited state (A{sup 1}Σ{sup +}) by the pump pulse. Then driven by a time-delayed dumping pulse, the prepared excited-state molecule can be transferred to the bound states of the ground electronic state. It is found thatmore » the pump process can induce a superposition of the rovibrational levels |v, j〉 on the excited state, which can lead to the field-free alignment of the excited-state molecule. The molecular alignment can affect the dumping process by varying the effective coupling intensity between the two electronic states or by varying the population transfer pathways. As a result, the final population transferred to the bound states of the ground electronic state varies periodically with the delay time of the dumping pulse.« less

SU-E-J-141: Assessment of the Magnitude and Impact of Trigger Delay in Respiratory Triggered Real-Time Imaging during Radiotherapy.

PubMed

Duan, J; Shen, S; Popple, R; Wu, X; Cardan, R; Brezovich, I

2012-06-01

To assess the trigger delay in respiratory triggered real-time imaging and its impact on image guided radiotherapy (IGRT) with Varian TrueBeam System. A sinusoidal motion phantom with 2cm motion amplitude was used. The trigger delay was determined directly with video image, and indirectly by the distance between expected and actual triggering phantom positions. For the direct method, a fluorescent screen was placed on the phantom to visualize the x-ray. The motion of the screen was recorded at 60 frames/second. The number of frames between the time when the phantom reached expected triggering position and the time when the screen was illuminated by the x-ray was used to determine the trigger delay. In the indirect method, triggered kV x-ray images were acquired in real-time during 'treatment' with triggers set at 25% and 75% respiratory phases where the phantom moved at the maximum speed. 39-40 triggered images were acquired continuously in each series. The distance between the expected and actual triggering points, d, was measured on the images to determine the delay time t by d=Asin(wt), where w=2π/T, T=period and A=amplitude. Motion periods of 2s and 4s were used in the measurement. The trigger delay time determined with direct video imaging was 125ms (7.5 video frames). The average distance between the expected and actual triggering positions determined by the indirect method was 3.93±0.74mm for T=4s and 7.02±1.25mm for T=2s, yielding mean trigger delay times of 126±24ms and 120±22ms, respectively. Although the mean over-travel distance is significant at 25% and 75% phases, clinically, the target over-travel resulted from the trigger delay at the end of expiration (50% phase) is negligibly small(< 0.5mm). The trigger delay in respiration-triggered imaging is in the range of 120-126ms. This delay has negligible clinical effect on gated IGRT. © 2012 American Association of Physicists in Medicine.

Consensus of satellite cluster flight using an energy-matching optimal control method

NASA Astrophysics Data System (ADS)

Luo, Jianjun; Zhou, Liang; Zhang, Bo

2017-11-01

This paper presents an optimal control method for consensus of satellite cluster flight under a kind of energy matching condition. Firstly, the relation between energy matching and satellite periodically bounded relative motion is analyzed, and the satellite energy matching principle is applied to configure the initial conditions. Then, period-delayed errors are adopted as state variables to establish the period-delayed errors dynamics models of a single satellite and the cluster. Next a novel satellite cluster feedback control protocol with coupling gain is designed, so that the satellite cluster periodically bounded relative motion consensus problem (period-delayed errors state consensus problem) is transformed to the stability of a set of matrices with the same low dimension. Based on the consensus region theory in the research of multi-agent system consensus issues, the coupling gain can be obtained to satisfy the requirement of consensus region and decouple the satellite cluster information topology and the feedback control gain matrix, which can be determined by Linear quadratic regulator (LQR) optimal method. This method can realize the consensus of satellite cluster period-delayed errors, leading to the consistency of semi-major axes (SMA) and the energy-matching of satellite cluster. Then satellites can emerge the global coordinative cluster behavior. Finally the feasibility and effectiveness of the present energy-matching optimal consensus for satellite cluster flight is verified through numerical simulations.

Temporal Influence on Awareness

DTIC Science & Technology

1995-12-01

43 38. Test Setup Timing: Measured vs Expected Modal Delays (in ms) ............. 46 39. Experiment I: visual and auditory stimuli...presented simultaneously; visual- auditory delay=Oms, visual-visual delay=0ms ....... .......................... 47 40. Experiment II: visual and auditory ...stimuli presented in order; visual- auditory de- lay=Oms, visual-visual delay=variable ................................ 48 41. Experiment II: visual and

Dynamical error bounds for continuum discretisation via Gauss quadrature rules—A Lieb-Robinson bound approach

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

Woods, M. P.; Centre for Quantum Technologies, National University of Singapore; QuTech, Delft University of Technology, Lorentzweg 1, 2611 CJ Delft

2016-02-15

Instances of discrete quantum systems coupled to a continuum of oscillators are ubiquitous in physics. Often the continua are approximated by a discrete set of modes. We derive error bounds on expectation values of system observables that have been time evolved under such discretised Hamiltonians. These bounds take on the form of a function of time and the number of discrete modes, where the discrete modes are chosen according to Gauss quadrature rules. The derivation makes use of tools from the field of Lieb-Robinson bounds and the theory of orthonormal polynomials.

Compensating for telecommunication delays during robotic telerehabilitation.

PubMed

Consoni, Leonardo J; Siqueira, Adriano A G; Krebs, Hermano I

2017-07-01

Rehabilitation robotic systems may afford better care and telerehabilitation may extend the use and benefits of robotic therapy to the home. Data transmissions over distance are bound by intrinsic communication delays which can be significant enough to deem the activity unfeasible. Here we describe an approach that combines unilateral robotic telerehabilitation and serious games. This approach has a modular and distributed design that permits different types of robots to interact without substantial code changes. We demonstrate the approach through an online multiplayer game. Two users can remotely interact with each other with no force exchanges, while a smoothing and prediction algorithm compensates motions for the delay in the Internet connection. We demonstrate that this approach can successfully compensate for data transmission delays, even when testing between the United States and Brazil. This paper presents the initial experimental results, which highlight the performance degradation with increasing delays as well as improvements provided by the proposed algorithm, and discusses planned future developments.

Robust exponential stability of uncertain delayed neural networks with stochastic perturbation and impulse effects.

PubMed

Huang, Tingwen; Li, Chuandong; Duan, Shukai; Starzyk, Janusz A

2012-06-01

This paper focuses on the hybrid effects of parameter uncertainty, stochastic perturbation, and impulses on global stability of delayed neural networks. By using the Ito formula, Lyapunov function, and Halanay inequality, we established several mean-square stability criteria from which we can estimate the feasible bounds of impulses, provided that parameter uncertainty and stochastic perturbations are well-constrained. Moreover, the present method can also be applied to general differential systems with stochastic perturbation and impulses.

A general theory of intertemporal decision-making and the perception of time.

PubMed

Namboodiri, Vijay M K; Mihalas, Stefan; Marton, Tanya M; Hussain Shuler, Marshall G

2014-01-01

Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier vs. later rewards (intertemporal decision-making) is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory-Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR)-that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval-over which experienced reward rate is estimated-as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the non-linearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception.

A general theory of intertemporal decision-making and the perception of time

PubMed Central

Namboodiri, Vijay M. K.; Mihalas, Stefan; Marton, Tanya M.; Hussain Shuler, Marshall G.

2014-01-01

Animals and humans make decisions based on their expected outcomes. Since relevant outcomes are often delayed, perceiving delays and choosing between earlier vs. later rewards (intertemporal decision-making) is an essential component of animal behavior. The myriad observations made in experiments studying intertemporal decision-making and time perception have not yet been rationalized within a single theory. Here we present a theory—Training-Integrated Maximized Estimation of Reinforcement Rate (TIMERR)—that explains a wide variety of behavioral observations made in intertemporal decision-making and the perception of time. Our theory postulates that animals make intertemporal choices to optimize expected reward rates over a limited temporal window which includes a past integration interval—over which experienced reward rate is estimated—as well as the expected delay to future reward. Using this theory, we derive mathematical expressions for both the subjective value of a delayed reward and the subjective representation of the delay. A unique contribution of our work is in finding that the past integration interval directly determines the steepness of temporal discounting and the non-linearity of time perception. In so doing, our theory provides a single framework to understand both intertemporal decision-making and time perception. PMID:24616677

Interpreting the Strongly Lensed Supernova iPTF16geu: Time Delay Predictions, Microlensing, and Lensing Rates

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

More, Anupreeta; Oguri, Masamune; More, Surhud

2017-02-01

We present predictions for time delays between multiple images of the gravitationally lensed supernova, iPTF16geu, which was recently discovered from the intermediate Palomar Transient Factory (iPTF). As the supernova is of Type Ia where the intrinsic luminosity is usually well known, accurately measured time delays of the multiple images could provide tight constraints on the Hubble constant. According to our lens mass models constrained by the Hubble Space Telescope F814W image, we expect the maximum relative time delay to be less than a day, which is consistent with the maximum of 100 hr reported by Goobar et al. but placesmore » a stringent upper limit. Furthermore, the fluxes of most of the supernova images depart from expected values suggesting that they are affected by microlensing. The microlensing timescales are small enough that they may pose significant problems to measure the time delays reliably. Our lensing rate calculation indicates that the occurrence of a lensed SN in iPTF is likely. However, the observed total magnification of iPTF16geu is larger than expected, given its redshift. This may be a further indication of ongoing microlensing in this system.« less

78 FR 59422 - Delayed Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-26

... Applications AGENCY: Office of Hazardous Materials Safety, Pipeline and Hazardous Materials Safety Administration (PHMSA), DOT. ACTION: List of applications delayed more than 180 days. SUMMARY: In accordance with... applications that have been in process for 180 days or more. The reason(s) for delay and the expected...

Synchronization of generalized reaction-diffusion neural networks with time-varying delays based on general integral inequalities and sampled-data control approach.

PubMed

Dharani, S; Rakkiyappan, R; Cao, Jinde; Alsaedi, Ahmed

2017-08-01

This paper explores the problem of synchronization of a class of generalized reaction-diffusion neural networks with mixed time-varying delays. The mixed time-varying delays under consideration comprise of both discrete and distributed delays. Due to the development and merits of digital controllers, sampled-data control is a natural choice to establish synchronization in continuous-time systems. Using a newly introduced integral inequality, less conservative synchronization criteria that assure the global asymptotic synchronization of the considered generalized reaction-diffusion neural network and mixed delays are established in terms of linear matrix inequalities (LMIs). The obtained easy-to-test LMI-based synchronization criteria depends on the delay bounds in addition to the reaction-diffusion terms, which is more practicable. Upon solving these LMIs by using Matlab LMI control toolbox, a desired sampled-data controller gain can be acuqired without any difficulty. Finally, numerical examples are exploited to express the validity of the derived LMI-based synchronization criteria.

The use of delay in multitrack production

NASA Astrophysics Data System (ADS)

Case, Alexander U.

2003-04-01

Delay, inevitable whenever sound propagates through space, is too often the bane of the acoustician's practice. An audible echo generally relegates a music performance hall-no matter how beautiful it otherwise might sound-to the lowest status. Multitrack music production on the other hand, with its aggressive use of overdubbing, editing, and signal processing, is not bound by those rules of time and space which determine the sound of a hall. In the recording studio, where music is synthesized for playback over loudspeakers, the delay is employed as a powerful, multipurpose tool. It is not avoided. It is in fact embraced. Echoes are used on purpose, strategically, to enhance the loudspeaker listening experience. Moreover, the humble delay is the basis for many nonecho effects. Flanging, chorus, and pitch shifting are delay-based effects regularly used in audio engineering practice. This paper discusses some of the more common delay-based effects, reviewing their technical structure, the psychoacoustic motivation behind them, and the musical value they create.

Comonotonic bounds on the survival probabilities in the Lee-Carter model for mortality projection

NASA Astrophysics Data System (ADS)

Denuit, Michel; Dhaene, Jan

2007-06-01

In the Lee-Carter framework, future survival probabilities are random variables with an intricate distribution function. In large homogeneous portfolios of life annuities, value-at-risk or conditional tail expectation of the total yearly payout of the company are approximately equal to the corresponding quantities involving random survival probabilities. This paper aims to derive some bounds in the increasing convex (or stop-loss) sense on these random survival probabilities. These bounds are obtained with the help of comonotonic upper and lower bounds on sums of correlated random variables.

Qualitative analysis of Cohen-Grossberg neural networks with multiple delays

NASA Astrophysics Data System (ADS)

Ye, Hui; Michel, Anthony N.; Wang, Kaining

1995-03-01

It is well known that a class of artificial neural networks with symmetric interconnections and without transmission delays, known as Cohen-Grossberg neural networks, possesses global stability (i.e., all trajectories tend to some equilibrium). We demonstrate in the present paper that many of the qualitative properties of Cohen-Grossberg networks will not be affected by the introduction of sufficiently small delays. Specifically, we establish some bound conditions for the time delays under which a given Cohen-Grossberg network with multiple delays is globally stable and possesses the same asymptotically stable equilibria as the corresponding network without delays. An effective method of determining the asymptotic stability of an equilibrium of a Cohen-Grossberg network with multiple delays is also presented. The present results are motivated by some of the authors earlier work [Phys. Rev. E 50, 4206 (1994)] and by some of the work of Marcus and Westervelt [Phys. Rev. A 39, 347 (1989)]. These works address qualitative analyses of Hopfield neural networks with one time delay. The present work generalizes these results to Cohen-Grossberg neural networks with multiple time delays. Hopfield neural networks constitute special cases of Cohen-Grossberg neural networks.

Application of Bounded Linear Stability Analysis Method for Metrics-Driven Adaptive Control

NASA Technical Reports Server (NTRS)

Bakhtiari-Nejad, Maryam; Nguyen, Nhan T.; Krishnakumar, Kalmanje

2009-01-01

This paper presents the application of Bounded Linear Stability Analysis (BLSA) method for metrics-driven adaptive control. The bounded linear stability analysis method is used for analyzing stability of adaptive control models, without linearizing the adaptive laws. Metrics-driven adaptive control introduces a notion that adaptation should be driven by some stability metrics to achieve robustness. By the application of bounded linear stability analysis method the adaptive gain is adjusted during the adaptation in order to meet certain phase margin requirements. Analysis of metrics-driven adaptive control is evaluated for a second order system that represents a pitch attitude control of a generic transport aircraft. The analysis shows that the system with the metrics-conforming variable adaptive gain becomes more robust to unmodeled dynamics or time delay. The effect of analysis time-window for BLSA is also evaluated in order to meet the stability margin criteria.

Frenetic Bounds on the Entropy Production

NASA Astrophysics Data System (ADS)

Maes, Christian

2017-10-01

We give a systematic derivation of positive lower bounds for the expected entropy production (EP) rate in classical statistical mechanical systems obeying a dynamical large deviation principle. The logic is the same for the return to thermodynamic equilibrium as it is for steady nonequilibria working under the condition of local detailed balance. We recover there recently studied "uncertainty" relations for the EP, appearing in studies about the effectiveness of mesoscopic machines. In general our refinement of the positivity of the expected EP rate is obtained in terms of a positive and even function of the expected current(s) which measures the dynamical activity in the system, a time-symmetric estimate of the changes in the system's configuration. Also underdamped diffusions can be included in the analysis.

Distributed containment control of heterogeneous fractional-order multi-agent systems with communication delays

NASA Astrophysics Data System (ADS)

Yang, Hongyong; Han, Fujun; Zhao, Mei; Zhang, Shuning; Yue, Jun

2017-08-01

Because many networked systems can only be characterized with fractional-order dynamics in complex environments, fractional-order calculus has been studied deeply recently. When diverse individual features are shown in different agents of networked systems, heterogeneous fractional-order dynamics will be used to describe the complex systems. Based on the distinguishing properties of agents, heterogeneous fractional-order multi-agent systems (FOMAS) are presented. With the supposition of multiple leader agents in FOMAS, distributed containment control of FOMAS is studied in directed weighted topologies. By applying Laplace transformation and frequency domain theory of the fractional-order operator, an upper bound of delays is obtained to ensure containment consensus of delayed heterogenous FOMAS. Consensus results of delayed FOMAS in this paper can be extended to systems with integer-order models. Finally, numerical examples are used to verify our results.

Academic Coping Skills and College Expectations of Learning Disabled High School Students.

ERIC Educational Resources Information Center

Dietrich, Amy P.; Kelly, Susan M.

This study assessed the level of academic coping skills being employed by 59 college-bound high school students with learning disabilities (LD), assessed the college-related expectations of these students, and compared these skills and expectations with those identified as essential by successful college students with learning disabilities.…

The Strong Lensing Time Delay Challenge (2014)

NASA Astrophysics Data System (ADS)

Liao, Kai; Dobler, G.; Fassnacht, C. D.; Treu, T.; Marshall, P. J.; Rumbaugh, N.; Linder, E.; Hojjati, A.

2014-01-01

Time delays between multiple images in strong lensing systems are a powerful probe of cosmology. At the moment the application of this technique is limited by the number of lensed quasars with measured time delays. However, the number of such systems is expected to increase dramatically in the next few years. Hundred such systems are expected within this decade, while the Large Synoptic Survey Telescope (LSST) is expected to deliver of order 1000 time delays in the 2020 decade. In order to exploit this bounty of lenses we needed to make sure the time delay determination algorithms have sufficiently high precision and accuracy. As a first step to test current algorithms and identify potential areas for improvement we have started a "Time Delay Challenge" (TDC). An "evil" team has created realistic simulated light curves, to be analyzed blindly by "good" teams. The challenge is open to all interested parties. The initial challenge consists of two steps (TDC0 and TDC1). TDC0 consists of a small number of datasets to be used as a training template. The non-mandatory deadline is December 1 2013. The "good" teams that complete TDC0 will be given access to TDC1. TDC1 consists of thousands of lightcurves, a number sufficient to test precision and accuracy at the subpercent level, necessary for time-delay cosmography. The deadline for responding to TDC1 is July 1 2014. Submissions will be analyzed and compared in terms of predefined metrics to establish the goodness-of-fit, efficiency, precision and accuracy of current algorithms. This poster describes the challenge in detail and gives instructions for participation.

National Airspace System Delay Estimation Using Weather Weighted Traffic Counts

NASA Technical Reports Server (NTRS)

Chatterji, Gano B.; Sridhar, Banavar

2004-01-01

Assessment of National Airspace System performance, which is usually measured in terms of delays resulting from the application of traffic flow management initiatives in response to weather conditions, volume, equipment outages and runway conditions, is needed both for guiding flow control decisions during the day of operations and for post operations analysis. Comparison of the actual delay, resulting from the traffic flow management initiatives, with the expected delay, based on traffic demand and other conditions, provides the assessment of the National Airspace System performance. This paper provides a method for estimating delay using the expected traffic demand and weather. In order to identify the cause of delays, 517 days of National Airspace System delay data reported by the Federal Aviation Administration s Operations Network were analyzed. This analysis shows that weather is the most important causal factor for delays followed by equipment and runway delays. Guided by these results, the concept of weather weighted traffic counts as a measure of system delay is described. Examples are given to show the variation of these counts as a function of time of the day. The various datasets, consisting of aircraft position data, enroute severe weather data, surface wind speed and visibility data, reported delay data and number of aircraft handled by the Centers data, and their sources are described. The procedure for selecting reference days on which traffic was minimally impacted by weather is described. Different traffic demand on each reference day of the week, determined by analysis of 42 days of traffic and delay data, was used as the expected traffic demand for each day of the week. Next, the method for computing the weather weighted traffic counts using the expected traffic demand, derived from reference days, and the expanded regions around severe weather cells is discussed. It is shown via a numerical example that this approach improves the dynamic range of the weather weighted traffic counts considerably. Time histories of these new weather weighted traffic counts are used for synthesizing two statistical features, six histogram features and six time domain features. In addition to these enroute weather features, two surface weather features of number of major airports in the United States with high mean winds and low mean visibility are also described. A least squares procedure for establishing a functional relation between the features, using combinations of these features, and system delays is explored using 36 days of data. Best correlations between the estimated delays using the functional relation and the actual delays provided by the Operations Network are obtained with two different combinations of features: 1) six time domain features of weather weighted traffic counts plus two surface weather features, and 2) six histogram features and mean of weather weighted traffic counts along with the two surface weather features. Correlation coefficient values of 0.73 and 0.83 were found in these two instances.

A time delay controller for magnetic bearings

NASA Technical Reports Server (NTRS)

Youcef-Toumi, K.; Reddy, S.

1991-01-01

The control of systems with unknown dynamics and unpredictable disturbances has raised some challenging problems. This is particularly important when high system performance needs to be guaranteed at all times. Recently, the Time Delay Control has been suggested as an alternative control scheme. The proposed control system does not require an explicit plant model nor does it depend on the estimation of specific plant parameters. Rather, it combines adaptation with past observations to directly estimate the effect of the plant dynamics. A control law is formulated for a class of dynamic systems and a sufficient condition is presented for control systems stability. The derivation is based on the bounded input-bounded output stability approach using L sub infinity function norms. The control scheme is implemented on a five degrees of freedom high speed and high precision magnetic bearing. The control performance is evaluated using step responses, frequency responses, and disturbance rejection properties. The experimental data show an excellent control performance despite the system complexity.

An efficient approach to ARMA modeling of biological systems with multiple inputs and delays

NASA Technical Reports Server (NTRS)

Perrott, M. H.; Cohen, R. J.

1996-01-01

This paper presents a new approach to AutoRegressive Moving Average (ARMA or ARX) modeling which automatically seeks the best model order to represent investigated linear, time invariant systems using their input/output data. The algorithm seeks the ARMA parameterization which accounts for variability in the output of the system due to input activity and contains the fewest number of parameters required to do so. The unique characteristics of the proposed system identification algorithm are its simplicity and efficiency in handling systems with delays and multiple inputs. We present results of applying the algorithm to simulated data and experimental biological data In addition, a technique for assessing the error associated with the impulse responses calculated from estimated ARMA parameterizations is presented. The mapping from ARMA coefficients to impulse response estimates is nonlinear, which complicates any effort to construct confidence bounds for the obtained impulse responses. Here a method for obtaining a linearization of this mapping is derived, which leads to a simple procedure to approximate the confidence bounds.

End-to-end QoS bounds for RTP-based service subnetworks

NASA Astrophysics Data System (ADS)

Pitts, Jonathan M.; Schormans, John A.

1999-11-01

With the increasing focus on traffic prioritization to support voice-data integration in corporate intranets, practical methods are needed to dimension and manage cost efficient service partitions. This is particularly important for the provisioning of real time, delay sensitive services such as telephony and voice/video conferencing applications. Typically these can be provided over RTP/UDP/IP or ATM DBR/SBR bearers but, irrespective of the specific networking technology, the switches or routers need to implement some form of virtual buffer management with queue scheduling mechanisms to provide partitioning. The key requirement is for operators of such networks to be able to dimension the partitions and virtual buffer sizes for efficient resource utilization, instead of simply over-dimensioning. This paper draws on recent work at Queen Mary, University of London, supported by the UK Engineering and Physical Sciences Research Council, to investigate approximate analytical methods for assessing end to end delay variation bounds in cell based and packet based networks.

Mice lacking the extracellular matrix protein MAGP1 display delayed thrombotic occlusion following vessel injury

PubMed Central

Werneck, Claudio C.; Vicente, Cristina P.; Weinberg, Justin S.; Shifren, Adrian; Pierce, Richard A.; Broekelmann, Thomas J.; Tollefsen, Douglas M.

2008-01-01

Mice lacking the extracellular matrix protein microfibril-associated glycoprotein-1 (MAGP1) display delayed thrombotic occlusion of the carotid artery following injury as well as prolonged bleeding from a tail vein incision. Normal occlusion times were restored when recombinant MAGP1 was infused into deficient animals prior to vessel wounding. Blood coagulation was normal in these animals as assessed by activated partial thromboplastin time and prothrombin time. Platelet number was lower in MAGP1-deficient mice, but the platelets showed normal aggregation properties in response to various agonists. MAGP1 was not found in normal platelets or in the plasma of wild-type mice. In ligand blot assays, MAGP1 bound to fibronectin, fibrinogen, and von Willebrand factor, but von Willebrand factor was the only protein of the 3 that bound to MAGP1 in surface plasmon resonance studies. These findings show that MAGP1, a component of microfibrils and vascular elastic fibers, plays a role in hemostasis and thrombosis. PMID:18281502

JPRS Report, Science & Technology USSR: Physics & Mathematics.

DTIC Science & Technology

1991-06-06

through a fixed delay line ( Porro prism ) and then a polarizer, the transmitted one passed through an adjustable delay line ( Porro prism ) and then a...radiation emitted by a plasma liner upon its compression into a plasma column. The target is a layer of material forming a resonance -bound ion pair...4.8338 nm wavelength corresponding to the resonance line of the 2s2 2S1/2 —> 3p 2P1/2° transition in the lithium-like A1XI ion pumping the 2s2 ’S0

The option value of delay in health technology assessment.

PubMed

Eckermann, Simon; Willan, Andrew R

2008-01-01

Processes of health technology assessment (HTA) inform decisions under uncertainty about whether to invest in new technologies based on evidence of incremental effects, incremental cost, and incremental net benefit monetary (INMB). An option value to delaying such decisions to wait for further evidence is suggested in the usual case of interest, in which the prior distribution of INMB is positive but uncertain. of estimating the option value of delaying decisions to invest have previously been developed when investments are irreversible with an uncertain payoff over time and information is assumed fixed. However, in HTA decision uncertainty relates to information (evidence) on the distribution of INMB. This article demonstrates that the option value of delaying decisions to allow collection of further evidence can be estimated as the expected value of sample of information (EVSI). For irreversible decisions, delay and trial (DT) is demonstrated to be preferred to adopt and no trial (AN) when the EVSI exceeds expected costs of information, including expected opportunity costs of not treating patients with the new therapy. For reversible decisions, adopt and trial (AT) becomes a potentially optimal strategy, but costs of reversal are shown to reduce the EVSI of this strategy due to both a lower probability of reversal being optimal and lower payoffs when reversal is optimal. Hence, decision makers are generally shown to face joint research and reimbursement decisions (AN, DT and AT), with the optimal choice dependent on costs of reversal as well as opportunity costs of delay and the distribution of prior INMB.

Bionic Control of Cheetah Bounding with a Segmented Spine.

PubMed

Wang, Chunlei; Wang, Shigang

2016-01-01

A cheetah model is built to mimic real cheetah and its mechanical and dimensional parameters are derived from the real cheetah. In particular, two joints in spine and four joints in a leg are used to realize the motion of segmented spine and segmented legs which are the key properties of the cheetah bounding. For actuating and stabilizing the bounding gait of cheetah, we present a bioinspired controller based on the state-machine. The controller mainly mimics the function of the cerebellum to plan the locomotion and keep the body balance. The haptic sensor and proprioception system are used to detect the trigger of the phase transition. Besides, the vestibular modulation could perceive the pitching angle of the trunk. At last, the cerebellum acts as the CPU to operate the information from the biological sensors. In addition, the calculated results are transmitted to the low-level controller to actuate and stabilize the cheetah bounding. Moreover, the delay feedback control method is employed to plan the motion of the leg joints to stabilize the pitching motion of trunk with the stability criterion. Finally, the cyclic cheetah bounding with biological properties is realized. Meanwhile, the stability and dynamic properties of the cheetah bounding gait are analyzed elaborately.

Dynamics of a neutral delay equation for an insect population with long larval and short adult phases

NASA Astrophysics Data System (ADS)

Gourley, Stephen A.; Kuang, Yang

We present a global study on the stability of the equilibria in a nonlinear autonomous neutral delay differential population model formulated by Bocharov and Hadeler. This model may be suitable for describing the intriguing dynamics of an insect population with long larval and short adult phases such as the periodical cicada. We circumvent the usual difficulties associated with the study of the stability of a nonlinear neutral delay differential model by transforming it to an appropriate non-neutral nonautonomous delay differential equation with unbounded delay. In the case that no juveniles give birth, we establish the positivity and boundedness of solutions by ad hoc methods and global stability of the extinction and positive equilibria by the method of iteration. We also show that if the time adjusted instantaneous birth rate at the time of maturation is greater than 1, then the population will grow without bound, regardless of the population death process.

Optimal exponential synchronization of general chaotic delayed neural networks: an LMI approach.

PubMed

Liu, Meiqin

2009-09-01

This paper investigates the optimal exponential synchronization problem of general chaotic neural networks with or without time delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality (LMI) technique. This general model, which is the interconnection of a linear delayed dynamic system and a bounded static nonlinear operator, covers several well-known neural networks, such as Hopfield neural networks, cellular neural networks (CNNs), bidirectional associative memory (BAM) networks, and recurrent multilayer perceptrons (RMLPs) with or without delays. Using the drive-response concept, time-delay feedback controllers are designed to synchronize two identical chaotic neural networks as quickly as possible. The control design equations are shown to be a generalized eigenvalue problem (GEVP) which can be easily solved by various convex optimization algorithms to determine the optimal control law and the optimal exponential synchronization rate. Detailed comparisons with existing results are made and numerical simulations are carried out to demonstrate the effectiveness of the established synchronization laws.

Sublinear Upper Bounds for Stochastic Programs with Recourse. Revision.

DTIC Science & Technology

1987-06-01

approximation procedures for (1.1) generally rely on discretizations of E (Huang, Ziemba , and Ben-Tal (1977), Kall and Stoyan (1982), Birge and Wets...Wright, Practical optimization (Academic Press, London and New York,1981). C.C. Huang, W. Ziemba , and A. Ben-Tal, "Bounds on the expectation of a con

Colorado Outward Bound School River Rafters' Manual.

ERIC Educational Resources Information Center

Leachman, Mark

Instructional sequences, safety rules, duties of crew members, and procedures for Colorado Outward Bound School river rafting trips are summarized in this manual. Designed to acquaint instructors with the duties expected of them on the trips, the information in the manual is presented in outline form and is intended for those with prior river…

Channel branching ratios in CH2CN- photodetachment: Rotational structure and vibrational energy redistribution in autodetachment

NASA Astrophysics Data System (ADS)

Lyle, Justin; Wedig, Olivia; Gulania, Sahil; Krylov, Anna I.; Mabbs, Richard

2017-12-01

We report photoelectron spectra of CH2CN-, recorded at photon energies between 13 460 and 15 384 cm-1, which show rapid intensity variations in particular detachment channels. The branching ratios for various spectral features reveal rotational structure associated with autodetachment from an intermediate anion state. Calculations using equation-of-motion coupled-cluster method with single and double excitations reveal the presence of two dipole-bound excited anion states (a singlet and a triplet). The computed oscillator strength for the transition to the singlet dipole-bound state provides an estimate of the autodetachment channel contribution to the total photoelectron yield. Analysis of the different spectral features allows identification of the dipole-bound and neutral vibrational levels involved in the autodetachment processes. For the most part, the autodetachment channels are consistent with the vibrational propensity rule and normal mode expectation. However, examination of the rotational structure shows that autodetachment from the ν3 (v = 1 and v = 2) levels of the dipole-bound state displays behavior counter to the normal mode expectation with the final state vibrational level belonging to a different mode.

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

NASA Astrophysics Data System (ADS)

Song, Qiankun; Cao, Jinde

2007-05-01

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

Stochastic hybrid delay population dynamics: well-posed models and extinction.

PubMed

Yuan, Chenggui; Mao, Xuerong; Lygeros, John

2009-01-01

Nonlinear differential equations have been used for decades for studying fluctuations in the populations of species, interactions of species with the environment, and competition and symbiosis between species. Over the years, the original non-linear models have been embellished with delay terms, stochastic terms and more recently discrete dynamics. In this paper, we investigate stochastic hybrid delay population dynamics (SHDPD), a very general class of population dynamics that comprises all of these phenomena. For this class of systems, we provide sufficient conditions to ensure that SHDPD have global positive, ultimately bounded solutions, a minimum requirement for a realistic, well-posed model. We then study the question of extinction and establish conditions under which an ecosystem modelled by SHDPD is doomed.

On Extended Dissipativity of Discrete-Time Neural Networks With Time Delay.

PubMed

Feng, Zhiguang; Zheng, Wei Xing

2015-12-01

In this brief, the problem of extended dissipativity analysis for discrete-time neural networks with time-varying delay is investigated. The definition of extended dissipativity of discrete-time neural networks is proposed, which unifies several performance measures, such as the H∞ performance, passivity, l2 - l∞ performance, and dissipativity. By introducing a triple-summable term in Lyapunov function, the reciprocally convex approach is utilized to bound the forward difference of the triple-summable term and then the extended dissipativity criterion for discrete-time neural networks with time-varying delay is established. The derived condition guarantees not only the extended dissipativity but also the stability of the neural networks. Two numerical examples are given to demonstrate the reduced conservatism and effectiveness of the obtained results.

A Distributed Algorithm for Economic Dispatch Over Time-Varying Directed Networks With Delays

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

Yang, Tao; Lu, Jie; Wu, Di

In power system operation, economic dispatch problem (EDP) is designed to minimize the total generation cost while meeting the demand and satisfying generator capacity limits. This paper proposes an algorithm based on the gradient-push method to solve the EDP in a distributed manner over communication networks potentially with time-varying topologies and communication delays. It has been shown that the proposed method is guaranteed to solve the EDP if the time-varying directed communication network is uniformly jointly strongly connected. Moreover, the proposed algorithm is also able to handle arbitrarily large but bounded time delays on communication links. Numerical simulations are usedmore » to illustrate and validate the proposed algorithm.« less

Adaptive output-feedback control for switched stochastic uncertain nonlinear systems with time-varying delay.

PubMed

Song, Zhibao; Zhai, Junyong

2018-04-01

This paper addresses the problem of adaptive output-feedback control for a class of switched stochastic time-delay nonlinear systems with uncertain output function, where both the control coefficients and time-varying delay are unknown. The drift and diffusion terms are subject to unknown homogeneous growth condition. By virtue of adding a power integrator technique, an adaptive output-feedback controller is designed to render that the closed-loop system is bounded in probability, and the state of switched stochastic nonlinear system can be globally regulated to the origin almost surely. A numerical example is provided to demonstrate the validity of the proposed control method. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Dynamic spin injection into a quantum well coupled to a spin-split bound state

NASA Astrophysics Data System (ADS)

Maslova, N. S.; Rozhansky, I. V.; Mantsevich, V. N.; Arseyev, P. I.; Averkiev, N. S.; Lähderanta, E.

2018-05-01

We present a theoretical analysis of dynamic spin injection due to spin-dependent tunneling between a quantum well (QW) and a bound state split in spin projection due to an exchange interaction or external magnetic field. We focus on the impact of Coulomb correlations at the bound state on spin polarization and sheet density kinetics of the charge carriers in the QW. The theoretical approach is based on kinetic equations for the electron occupation numbers taking into account high order correlation functions for the bound state electrons. It is shown that the on-site Coulomb repulsion leads to an enhanced dynamic spin polarization of the electrons in the QW and a delay in the carriers tunneling into the bound state. The interplay of these two effects leads to nontrivial dependence of the spin polarization degree, which can be probed experimentally using time-resolved photoluminescence experiments. It is demonstrated that the influence of the Coulomb interactions can be controlled by adjusting the relaxation rates. These findings open a new way of studying the Hubbard-like electron interactions experimentally.

Performance Analysis of the United States Marine Corps War Reserve Materiel Program Process Flow

DTIC Science & Technology

2016-12-01

or Less)............41 Figure 21. Tornado Diagram of Expected Delays Using 2016 Inputs ........................42 x Figure 22. Fishbone Diagram of...variability. Using Crystal Ball we produced a Tornado Diagram (similar to a Pareto Chart) in order to tell us where to focus our efforts. The results of...the Tornado Diagram are shown in Figure 21. Figure 21. Tornado Diagram of Expected Delays Using 2016 Inputs Using the results shown in the Tornado

Incorporating Active Runway Crossings in Airport Departure Scheduling

NASA Technical Reports Server (NTRS)

Gupta, Gautam; Malik, Waqar; Jung, Yoon C.

2010-01-01

A mixed integer linear program is presented for deterministically scheduling departure and ar rival aircraft at airport runways. This method addresses different schemes of managing the departure queuing area by treating it as first-in-first-out queues or as a simple par king area where any available aircraft can take-off ir respective of its relative sequence with others. In addition, this method explicitly considers separation criteria between successive aircraft and also incorporates an optional prioritization scheme using time windows. Multiple objectives pertaining to throughput and system delay are used independently. Results indicate improvement over a basic first-come-first-serve rule in both system delay and throughput. Minimizing system delay results in small deviations from optimal throughput, whereas minimizing throughput results in large deviations in system delay. Enhancements for computational efficiency are also presented in the form of reformulating certain constraints and defining additional inequalities for better bounds.

Stabilization strategies of a general nonlinear car-following model with varying reaction-time delay of the drivers.

PubMed

Li, Shukai; Yang, Lixing; Gao, Ziyou; Li, Keping

2014-11-01

In this paper, the stabilization strategies of a general nonlinear car-following model with reaction-time delay of the drivers are investigated. The reaction-time delay of the driver is time varying and bounded. By using the Lyapunov stability theory, the sufficient condition for the existence of the state feedback control strategy for the stability of the car-following model is given in the form of linear matrix inequality, under which the traffic jam can be well suppressed with respect to the varying reaction-time delay. Moreover, by considering the external disturbance for the running cars, the robust state feedback control strategy is designed, which ensures robust stability and a smaller prescribed H∞ disturbance attenuation level for the traffic flow. Numerical examples are given to illustrate the effectiveness of the proposed methods. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

Relative position coordinated control for spacecraft formation flying with communication delays

NASA Astrophysics Data System (ADS)

Ran, Dechao; Chen, Xiaoqian; Misra, Arun K.; Xiao, Bing

2017-08-01

This study addresses a relative position coordinated control problem for spacecraft formation flying subject to directed communication topology. Two different kinds of communication delay cases, including time-varying delays and arbitrarily bounded delays are investigated. Using the backstepping control technique, two virtual velocity control inputs are firstly designed to achieve coordinated position tracking for the kinematic subsystem. Furthermore, a hyperbolic tangent function is introduced to guarantee the boundedness of the virtual controller. Then, a finite-time control algorithm is designed for the dynamic subsystem. It can guarantee that the virtual velocity can be followed by the real velocity after finite time. It is theoretically proved that the proposed control scheme can asymptotically stabilize the closed-loop system. Numerical simulations are further presented that not only highlight closed-loop performance benefiting from the proposed control scheme, but also illustrate its superiority in comparison with conventional formation control schemes.

75 FR 45628 - Delayed Update of the HHS Poverty Guidelines for the Remainder of 2010

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-03

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Office of the Secretary Delayed Update of the HHS Poverty...: This notice provides a delayed update of the Department of Health and Human Services (HHS) poverty guidelines for the remainder of 2010, and until the 2011 poverty guidelines are published, which is expected...

Distributed Optimal Consensus Control for Multiagent Systems With Input Delay.

PubMed

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

2018-06-01

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

USING 19F-NMR SPECTROSCOPY TO DETERMINE TRIFLURALIN BINDING TO SOIL

EPA Science Inventory

Trifluralin is a widely used herbicide for the control of broad leaf weeds in a variety of crops. Its binding to soil may result in significant losses in herbicidal activity and a delayed pollution problem. To investigate the nature of soil-bound trifluralin residues, ¹⁴

Measuring border delay and crossing times at the US-Mexico border : final report on automated crossing and wait time measurement.

DOT National Transportation Integrated Search

2012-08-01

A pilot test implemented a radio frequency identification (RFID) system to automatically measure travel times of US-bound commercial vehicles at a selected Port of Entry (POE) on the USMexico border under long-term, real-world conditions. The init...

Serratia marcescens Is Able to Survive and Proliferate in Autophagic-Like Vacuoles inside Non-Phagocytic Cells

PubMed Central

Colombo, María Isabel; García Véscovi, Eleonora

2011-01-01

Serratia marcescens is an opportunistic human pathogen that represents a growing problem for public health, particularly in hospitalized or immunocompromised patients. However, little is known about factors and mechanisms that contribute to S. marcescens pathogenesis within its host. In this work, we explore the invasion process of this opportunistic pathogen to epithelial cells. We demonstrate that once internalized, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment. This structure displays autophagic-like features, acquiring LC3 and Rab7, markers described to be recruited throughout the progression of antibacterial autophagy. The majority of the autophagic-like vacuoles in which Serratia resides and proliferates are non-acidic and have no degradative properties, indicating that the bacteria are capable to either delay or prevent fusion with lysosomal compartments, altering the expected progression of autophagosome maturation. In addition, our results demonstrate that Serratia triggers a non-canonical autophagic process before internalization. These findings reveal that S. marcescens is able to manipulate the autophagic traffic, generating a suitable niche for survival and proliferation inside the host cell. PMID:21901159

Stability and Hopf bifurcation for a business cycle model with expectation and delay

NASA Astrophysics Data System (ADS)

Liu, Xiangdong; Cai, Wenli; Lu, Jiajun; Wang, Yangyang

2015-08-01

According to rational expectation hypothesis, the government will take into account the future capital stock in the process of investment decision. By introducing anticipated capital stock into an economic model with investment delay, we construct a mixed functional differential system including delay and advanced variables. The system is converted to the one containing only delay by variable substitution. The equilibrium point of the system is obtained and its dynamical characteristics such as stability, Hopf bifurcation and its stability and direction are investigated by using the related theories of nonlinear dynamics. We carry out some numerical simulations to confirm these theoretical conclusions. The results indicate that both capital stock's anticipation and investment lag are the certain factors leading to the occurrence of cyclical fluctuations in the macroeconomic system. Moreover, the level of economic fluctuation can be dampened to some extent if investment decisions are made by the reasonable short-term forecast on capital stock.

An exploratory study of the changes in benefits sought during an outward bound experience

Treesearch

Frederick Kacprzynski

1992-01-01

Participants in an eight-day Outward Bound program were asked about their motivations for participation before the experience began and at the mid-point of the actual experience. Although more anticipated differences were expected, based on motivational theory, only one of the twelve motivational domains was significantly different at the .001 level.

The Mobile Browsing Behaviors and Expectations of College-Bound High School Students. An E-Expectations Trend Report

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2012

2012-01-01

The last decade marked a dramatic change in the college search experience as students flocked to the Internet as their primary tool for researching colleges. Institutions had to transform their recruitment efforts to keep up with the online demands and expectations of prospective students. The proliferation of smartphones is transforming the…

Uncertainty, imprecision, and the precautionary principle in climate change assessment.

PubMed

Borsuk, M E; Tomassini, L

2005-01-01

Statistical decision theory can provide useful support for climate change decisions made under conditions of uncertainty. However, the probability distributions used to calculate expected costs in decision theory are themselves subject to uncertainty, disagreement, or ambiguity in their specification. This imprecision can be described using sets of probability measures, from which upper and lower bounds on expectations can be calculated. However, many representations, or classes, of probability measures are possible. We describe six of the more useful classes and demonstrate how each may be used to represent climate change uncertainties. When expected costs are specified by bounds, rather than precise values, the conventional decision criterion of minimum expected cost is insufficient to reach a unique decision. Alternative criteria are required, and the criterion of minimum upper expected cost may be desirable because it is consistent with the precautionary principle. Using simple climate and economics models as an example, we determine the carbon dioxide emissions levels that have minimum upper expected cost for each of the selected classes. There can be wide differences in these emissions levels and their associated costs, emphasizing the need for care when selecting an appropriate class.

Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography

NASA Astrophysics Data System (ADS)

Stagno, J. R.; Liu, Y.; Bhandari, Y. R.; Conrad, C. E.; Panja, S.; Swain, M.; Fan, L.; Nelson, G.; Li, C.; Wendel, D. R.; White, T. A.; Coe, J. D.; Wiedorn, M. O.; Knoska, J.; Oberthuer, D.; Tuckey, R. A.; Yu, P.; Dyba, M.; Tarasov, S. G.; Weierstall, U.; Grant, T. D.; Schwieters, C. D.; Zhang, J.; Ferré-D'Amaré, A. R.; Fromme, P.; Draper, D. E.; Liang, M.; Hunter, M. S.; Boutet, S.; Tan, K.; Zuo, X.; Ji, X.; Barty, A.; Zatsepin, N. A.; Chapman, H. N.; Spence, J. C. H.; Woodson, S. A.; Wang, Y.-X.

2017-01-01

Riboswitches are structural RNA elements that are generally located in the 5‧ untranslated region of messenger RNA. During regulation of gene expression, ligand binding to the aptamer domain of a riboswitch triggers a signal to the downstream expression platform. A complete understanding of the structural basis of this mechanism requires the ability to study structural changes over time. Here we use femtosecond X-ray free electron laser (XFEL) pulses to obtain structural measurements from crystals so small that diffusion of a ligand can be timed to initiate a reaction before diffraction. We demonstrate this approach by determining four structures of the adenine riboswitch aptamer domain during the course of a reaction, involving two unbound apo structures, one ligand-bound intermediate, and the final ligand-bound conformation. These structures support a reaction mechanism model with at least four states and illustrate the structural basis of signal transmission. The three-way junction and the P1 switch helix of the two apo conformers are notably different from those in the ligand-bound conformation. Our time-resolved crystallographic measurements with a 10-second delay captured the structure of an intermediate with changes in the binding pocket that accommodate the ligand. With at least a 10-minute delay, the RNA molecules were fully converted to the ligand-bound state, in which the substantial conformational changes resulted in conversion of the space group. Such notable changes in crystallo highlight the important opportunities that micro- and nanocrystals may offer in these and similar time-resolved diffraction studies. Together, these results demonstrate the potential of ‘mix-and-inject’ time-resolved serial crystallography to study biochemically important interactions between biomacromolecules and ligands, including those that involve large conformational changes.

Structures of riboswitch RNA reaction states by mix-and-inject XFEL serial crystallography

PubMed Central

Stagno, J. R.; Liu, Y.; Bhandari, Y. R.; Conrad, C. E.; Panja, S.; Swain, M.; Fan, L.; Nelson, G.; Li, C.; Wendel, D. R.; White, T. A.; Coe, J. D.; Wiedorn, M. O.; Knoska, J.; Oberthuer, D.; Tuckey, R. A.; Yu, P.; Dyba, M.; Tarasov, S. G.; Weierstall, U.; Grant, T. D.; Schwieters, C. D.; Zhang, J.; Ferré-D’Amaré, A. R.; Fromme, P.; Draper, D. E.; Liang, M.; Hunter, M. S.; Boutet, S.; Tan, K.; Zuo, X.; Ji, X.; Barty, A.; Zatsepin, N. A.; Chapman, H. N.; Spence, J. C. H.; Woodson, S. A.; Wang, Y.-X.

2017-01-01

Riboswitches are structural RNA elements that are generally located in the 5′ untranslated region of messenger RNA. During regulation of gene expression, ligand binding to the aptamer domain of a riboswitch triggers a signal to the downstream expression platform1–3. A complete understanding of the structural basis of this mechanism requires the ability to study structural changes over time4. Here we use femtosecond X-ray free electron laser (XFEL) pulses5,6 to obtain structural measurements from crystals so small that diffusion of a ligand can be timed to initiate a reaction before diffraction. We demonstrate this approach by determining four structures of the adenine riboswitch aptamer domain during the course of a reaction, involving two unbound apo structures, one ligand-bound intermediate, and the final ligand-bound conformation. These structures support a reaction mechanism model with at least four states and illustrate the structural basis of signal transmission. The three-way junction and the P1 switch helix of the two apo conformers are notably different from those in the ligand-bound conformation. Our time-resolved crystallographic measurements with a 10-second delay captured the structure of an intermediate with changes in the binding pocket that accommodate the ligand. With at least a 10-minute delay, the RNA molecules were fully converted to the ligand-bound state, in which the substantial conformational changes resulted in conversion of the space group. Such notable changes in crystallo highlight the important opportunities that micro- and nanocrystals may offer in these and similar time-resolved diffraction studies. Together, these results demonstrate the potential of ‘mix-and-inject’ time-resolved serial crystallography to study biochemically important interactions between biomacromolecules and ligands, including those that involve large conformational changes. PMID:27841871

Distributed Load Shedding over Directed Communication Networks with Time Delays

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

Yang, Tao; Wu, Di

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

Effect of antibodies on pathogen dynamics with delays and two routes of infection

NASA Astrophysics Data System (ADS)

Elaiw, A. M.; Almatrafi, A. A.; Hobiny, A. D.

2018-06-01

We study the global stability of pathogen dynamics models with saturated pathogen-susceptible and infected-susceptible incidence. The models incorporate antibody immune response and three types of discrete or distributed time delays. We first show that the solutions of the model are nonnegative and ultimately bounded. We determine two threshold parameters, the basic reproduction number and antibody response activation number. We establish the existence and stability of the steady states. We study the global stability analysis of models using Lyapunov method. The numerical simulations have shown that antibodies can reduce the pathogen progression.

Temporal analysis of nonresonant two-photon coherent control involving bound and dissociative molecular states

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

Su Jing; Chen Shaohao; Jaron-Becker, Agnieszka

We theoretically study the control of two-photon excitation to bound and dissociative states in a molecule induced by trains of laser pulses, which are equivalent to certain sets of spectral phase modulated pulses. To this end, we solve the time-dependent Schroedinger equation for the interaction of molecular model systems with an external intense laser field. Our numerical results for the temporal evolution of the population in the excited states show that, in the case of an excited dissociative state, control schemes, previously validated for the atomic case, fail due to the coupling of electronic and nuclear motion. In contrast, formore » excitation to bound states the two-photon excitation probability is controlled via the time delay and the carrier-envelope phase difference between two consecutive pulses in the train.« less

Effects of the gaseous and liquid water content of the atmosphere on range delay and Doppler frequency

NASA Technical Reports Server (NTRS)

Flock, W. L.

1981-01-01

When high precision is required for range measurement on Earth space paths, it is necessary to correct as accurately as possible for excess range delays due to the dry air, water vapor, and liquid water content of the atmosphere. Calculations based on representative values of atmospheric parameters are useful for illustrating the order of magnitude of the expected delays. Range delay, time delay, and phase delay are simply and directly related. Doppler frequency variations or noise are proportional to the time rate of change of excess range delay. Tropospheric effects were examined as part of an overall consideration of the capability of precision two way ranging and Doppler systems.

Exponential synchronization of neural networks with discrete and distributed delays under time-varying sampling.

PubMed

Wu, Zheng-Guang; Shi, Peng; Su, Hongye; Chu, Jian

2012-09-01

This paper investigates the problem of master-slave synchronization for neural networks with discrete and distributed delays under variable sampling with a known upper bound on the sampling intervals. An improved method is proposed, which captures the characteristic of sampled-data systems. Some delay-dependent criteria are derived to ensure the exponential stability of the error systems, and thus the master systems synchronize with the slave systems. The desired sampled-data controller can be achieved by solving a set of linear matrix inequalitys, which depend upon the maximum sampling interval and the decay rate. The obtained conditions not only have less conservatism but also have less decision variables than existing results. Simulation results are given to show the effectiveness and benefits of the proposed methods.

Binding among Select Episodic Elements Is Altered via Active Short-Term Retrieval

ERIC Educational Resources Information Center

Bridge, Donna J.; Voss, Joel L.

2015-01-01

Of the many elements that comprise an episode, are any disproportionately bound to the others? We tested whether active short-term retrieval selectively increases binding. Individual objects from multiobject displays were retrieved after brief delays. Memory was later tested for the other objects. Cueing with actively retrieved objects facilitated…

This Year, It's Prospective Freshmen Who Are Keeping Colleges in Suspense.

ERIC Educational Resources Information Center

Gose, Ben

2000-01-01

Finds that while more college-bound students are utilizing the early decision process, many others are delaying their decision until the last possible moment. Reasons cited include rising costs, need for more financial aid, and increasing selectivity. Notes that increased number of students graduating from high school and booming economy have made…

A Distance Bounding Protocol for Location-Cloaked Applications

PubMed Central

Molina-Martínez, Cristián; Galdames, Patricio

2018-01-01

Location-based services (LBSs) assume that users are willing to release trustworthy and useful details about their whereabouts. However, many location privacy concerns have arisen. For location privacy protection, several algorithms build a cloaking region to hide a user’s location. However, many applications may not operate adequately on cloaked locations. For example, a traditional distance bounding protocol (DBP)—which is run by two nodes called the prover and the verifier—may conclude an untight and useless distance between these two entities. An LBS (verifier) may use this distance as a metric of usefulness and trustworthiness of the location claimed by the user (prover). However, we show that if a tight distance is desired, traditional DBP can refine a user’s cloaked location and compromise its location privacy. To find a proper balance, we propose a location-privacy-aware DBP protocol. Our solution consists of adding some small delays before submitting any user’s response. We show that several issues arise when a certain delay is chosen, and we propose some solutions. The effectiveness of our techniques in balancing location refinement and utility is demonstrated through simulation. PMID:29701641

Barriers to help-seeking in men diagnosed with benign colorectal diseases.

PubMed

Oberoi, Devesh V; Jiwa, Moyez; McManus, Alexandra; Hodder, Rupert

2015-01-01

To explore the help-seeking pathway for lower bowel symptoms in men diagnosed with benign bowel diseases. Semi-structured interviews were conducted. The data were analyzed thematically using Andersen's Model of Patient Delay as the theoretical framework. The major delaying factors were attribution of symptoms to self-limiting conditions, failure to make time to visit a GP, low expectation of help from the GP, fear of cancer diagnosis and embarrassment. The major causes of delay in help-seeking were related to the participants, whereas factors associated with treatment delay were less prominent in diagnostic delay.

On constraining the speed of gravitational waves following GW150914

NASA Astrophysics Data System (ADS)

Blas, D.; Ivanov, M. M.; Sawicki, I.; Sibiryakov, S.

2016-05-01

We point out that the observed time delay between the detection of the signal at the Hanford and Livingston LIGO sites from the gravitational wave event GW150914 places an upper bound on the speed of propagation of gravitational waves, c gw ≲ 1.7 in the units of speed of light. Combined with the lower bound from the absence of gravitational Cherenkov losses by cosmic rays that rules out most of subluminal velocities, this gives a model-independent double-sided constraint 1 ≲ c gw ≲ 1.7. We compare this result to model-specific constraints from pulsar timing and cosmology.

Culturally Responsive Positive Behavior Supports: Considerations for Practice

ERIC Educational Resources Information Center

Banks, Tachelle; Obiakor, Festus E.

2015-01-01

Classrooms are not culturally neutral terrains, but rather are constructed around sets of norms, values, and expected behaviors that are culturally bound. Low tolerance levels and expectations are an indication of the incongruence between the education strategies utilized by teachers and the cultural and linguistic differences of students that are…

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

NASA Astrophysics Data System (ADS)

Smilansky, Uzy; Schanz, Holger

2018-02-01

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

Finite-time resilient decentralized control for interconnected impulsive switched systems with neutral delay.

PubMed

Ren, Hangli; Zong, Guangdeng; Hou, Linlin; Yang, Yi

2017-03-01

This paper is concerned with the problem of finite-time control for a class of interconnected impulsive switched systems with neutral delay in which the time-varying delay appears in both the state and the state derivative. The concepts of finite-time boundedness and finite-time stability are respectively extended to interconnected impulsive switched systems with neutral delay for the first time. By applying the average dwell time method, sufficient conditions are first derived to cope with the problem of finite-time boundedness and finite-time stability for interconnected impulsive switched systems with neutral delay. In addition, the purpose of finite-time resilient decentralized control is to construct a resilient decentralized state-feedback controller such that the closed-loop system is finite-time bounded and finite-time stable. All the conditions are formulated in terms of linear matrix inequalities to ensure finite-time boundedness and finite-time stability of the given system. Finally, an example is presented to illustrate the effectiveness of the proposed approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Do framing effects reveal irrational choice?

PubMed

Mandel, David R

2014-06-01

Framing effects have long been viewed as compelling evidence of irrationality in human decision making, yet that view rests on the questionable assumption that numeric quantifiers used to convey the expected values of choice options are uniformly interpreted as exact values. Two experiments show that when the exactness of such quantifiers is made explicit by the experimenter, framing effects vanish. However, when the same quantifiers are given a lower bound (at least) meaning, the typical framing effect is found. A 3rd experiment confirmed that most people spontaneously interpret the quantifiers in standard framing tests as lower bounded and that their interpretations strongly moderate the framing effect. Notably, in each experiment, a significant majority of participants made rational choices, either choosing the option that maximized expected value (i.e., lives saved) or choosing consistently across frames when the options were of equal expected value. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Cognitive and personality factors in the delay of gratification of hemodialysis patients.

PubMed

Rosenbaum, M; Ben-Ari Smira, K

1986-08-01

On the basis of Mischel's (1984) social learning analysis of the process of delay of gratification in children and in line with Bandura's (1977) self-efficacy theory, we developed a model of delay of gratification in adults and tested it on dialysis patients who were continuously required to comply with a stringent regimen of fluid-intake to keep alive. We hypothesized that patients' self-evaluations of their past compliance and their efficacy expectations would be associated with their actual delay behavior. Underlying these process-regulating cognitions would be stable competencies, such as learned resourcefulness (i.e., one's self-control skills). Fifty-three dialysis patients self-evaluated their fluid intake compliance, their efficacy expectations, and their health beliefs. Resourcefulness was assessed by Rosenbaum's Self-Control Schedule. Actual fluid-intake compliance was reliably assessed by the mean body weight increase between dialyses during the 3-month period prior to the study and during two follow-up periods. The results supported the model. On the one hand, self-efficacy expectations were related to persistence with the fluid diet and on the other hand to subjects' self-evaluation of their past adherence behavior as well as to their resourcefulness. Although the path model suggested a causal pattern, the correlational nature of the study precluded any conclusions on cause-effect relationship.

A Pulsed Sphere Tutorial

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

Cullen, Dermott E.

2017-01-30

Here I attempt to explain what physically happens when we pulse an object with neutrons, specifically what we expect the time dependent behavior of the neutron population to look like. Emphasis is on the time dependent emission of both prompt and delayed neutrons. I also describe how the TART Monte Carlo transport code models this situation; see the appendix for a complete description of the model used by TART. I will also show that, as we expect, MCNP and MERCURY, produce similar results using the same delayed neutron model (again, see the appendix).

Long-Delayed Aftershocks in New Zealand and the 2016 M7.8 Kaikoura Earthquake

NASA Astrophysics Data System (ADS)

Shebalin, P.; Baranov, S.

2017-10-01

We study aftershock sequences of six major earthquakes in New Zealand, including the 2016 M7.8 Kaikaoura and 2016 M7.1 North Island earthquakes. For Kaikaoura earthquake, we assess the expected number of long-delayed large aftershocks of M5+ and M5.5+ in two periods, 0.5 and 3 years after the main shocks, using 75 days of available data. We compare results with obtained for other sequences using same 75-days period. We estimate the errors by considering a set of magnitude thresholds and corresponding periods of data completeness and consistency. To avoid overestimation of the expected rates of large aftershocks, we presume a break of slope of the magnitude-frequency relation in the aftershock sequences, and compare two models, with and without the break of slope. Comparing estimations to the actual number of long-delayed large aftershocks, we observe, in general, a significant underestimation of their expected number. We can suppose that the long-delayed aftershocks may reflect larger-scale processes, including interaction of faults, that complement an isolated relaxation process. In the spirit of this hypothesis, we search for symptoms of the capacity of the aftershock zone to generate large events months after the major earthquake. We adapt an algorithm EAST, studying statistics of early aftershocks, to the case of secondary aftershocks within aftershock sequences of major earthquakes. In retrospective application to the considered cases, the algorithm demonstrates an ability to detect in advance long-delayed aftershocks both in time and space domains. Application of the EAST algorithm to the 2016 M7.8 Kaikoura earthquake zone indicates that the most likely area for a delayed aftershock of M5.5+ or M6+ is at the northern end of the zone in Cook Strait.

Capacity-Delay Trade-Off in Collaborative Hybrid Ad-Hoc Networks with Coverage Sensing.

PubMed

Chen, Lingyu; Luo, Wenbin; Liu, Chen; Hong, Xuemin; Shi, Jianghong

2017-01-26

The integration of ad hoc device-to-device (D2D) communications and open-access small cells can result in a networking paradigm called hybrid the ad hoc network, which is particularly promising in delivering delay-tolerant data. The capacity-delay performance of hybrid ad hoc networks has been studied extensively under a popular framework called scaling law analysis. These studies, however, do not take into account aspects of interference accumulation and queueing delay and, therefore, may lead to over-optimistic results. Moreover, focusing on the average measures, existing works fail to give finer-grained insights into the distribution of delays. This paper proposes an alternative analytical framework based on queueing theoretic models and physical interference models. We apply this framework to study the capacity-delay performance of a collaborative cellular D2D network with coverage sensing and two-hop relay. The new framework allows us to fully characterize the delay distribution in the transform domain and pinpoint the impacts of coverage sensing, user and base station densities, transmit power, user mobility and packet size on the capacity-delay trade-off. We show that under the condition of queueing equilibrium, the maximum throughput capacity per device saturates to an upper bound of 0.7239 λ b / λ u bits/s/Hz, where λ b and λ u are the densities of base stations and mobile users, respectively.

Capacity-Delay Trade-Off in Collaborative Hybrid Ad-Hoc Networks with Coverage Sensing

PubMed Central

Chen, Lingyu; Luo, Wenbin; Liu, Chen; Hong, Xuemin; Shi, Jianghong

2017-01-01

The integration of ad hoc device-to-device (D2D) communications and open-access small cells can result in a networking paradigm called hybrid the ad hoc network, which is particularly promising in delivering delay-tolerant data. The capacity-delay performance of hybrid ad hoc networks has been studied extensively under a popular framework called scaling law analysis. These studies, however, do not take into account aspects of interference accumulation and queueing delay and, therefore, may lead to over-optimistic results. Moreover, focusing on the average measures, existing works fail to give finer-grained insights into the distribution of delays. This paper proposes an alternative analytical framework based on queueing theoretic models and physical interference models. We apply this framework to study the capacity-delay performance of a collaborative cellular D2D network with coverage sensing and two-hop relay. The new framework allows us to fully characterize the delay distribution in the transform domain and pinpoint the impacts of coverage sensing, user and base station densities, transmit power, user mobility and packet size on the capacity-delay trade-off. We show that under the condition of queueing equilibrium, the maximum throughput capacity per device saturates to an upper bound of 0.7239 λb/λu bits/s/Hz, where λb and λu are the densities of base stations and mobile users, respectively. PMID:28134769

Fusion protein based on Grb2-SH2 domain for cancer therapy

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

Saito, Yuriko; Graduate School of Pharmaceutical Sciences, Chiba University; Furukawa, Takako, E-mail: tfuru@nirs.go.jp

2010-08-20

Research highlights: {yields} Grb2 mediates EGFR signaling through binding to phosphorylate EGFR with SH2 domain. {yields} We generated fusion proteins containing 1 or 2 SH2 domains of Grb2 added with TAT. {yields} The one with 2 SH2 domains (TSSF) interfered ERK phosphorylation. {yields} TSSF significantly delayed the growth of EGFR overexpressing tumor in a mouse model. -- Abstract: Epidermal growth factor receptor (EGFR) is one of the very attractive targets for cancer therapy. In this study, we generated fusion proteins containing one or two Src-homology 2 (SH2) domains of growth factor receptor bound protein 2 (Grb2), which bind to phosphorylatedmore » EGFR, added with HIV-1 transactivating transcription for cell membrane penetration (termed TSF and TSSF, respectively). We examined if they can interfere Grb2-mediated signaling pathway and suppress tumor growth as expected from the lack of SH3 domain, which is necessary to intermediate EGFR-Grb2 cell signaling, in the fusion proteins. The transduction efficiency of TSSF was similar to that of TSF, but the binding activity of TSSF to EGFR was higher than that of TSF. Treatment of EGFR-overexpressing cells showed that TSSF decreased p42-ERK phosphorylation, while TSF did not. Both the proteins delayed cell growth but did not induce cell death in culture. TSSF also significantly suppressed tumor growth in vivo under consecutive administration. In conclusion, TSSF showed an ability to inhibit EGFR-Grb2 signaling and could have a potential to treat EGFR-activated cancer.« less

Two Upper Bounds for the Weighted Path Length of Binary Trees. Report No. UIUCDCS-R-73-565.

ERIC Educational Resources Information Center

Pradels, Jean Louis

Rooted binary trees with weighted nodes are structures encountered in many areas, such as coding theory, searching and sorting, information storage and retrieval. The path length is a meaningful quantity which gives indications about the expected time of a search or the length of a code, for example. In this paper, two sharp bounds for the total…

Effects of diet and host access on fecundity and lifespan in two fruit fly species with different life history patterns

PubMed Central

Harwood, James F.; Chen, Kehui; Müller, Hans-Georg; Wang, Jane-Ling; Vargas, Roger I.; Carey, James R.

2013-01-01

The reproductive ability of female tephritids can be limited and prevented by denying access to host plants and restricting the dietary precursors of vitellogenesis. The mechanisms underlying the delayed egg production in each case are initiated by different physiological processes that are anticipated to have dissimilar effects on lifespan and reproductive ability later in life. The egg laying abilities of laboratory reared females of the Mediterranean fruit fly (Ceratitis capitata Wiedmann) and melon fly (Bactrocera cucurbitae Coquillett) from Hawaii are delayed or suppressed by limiting access to host fruits and dietary protein. In each case, this is expected to prevent the loss of lifespan associated with reproduction until protein or hosts are introduced. Two trends are observed in each species: Firstly, access to protein at eclosion leads to a greater probability of survival and higher reproductive ability than if it is delayed, and secondly, that delayed host access reduces lifetime reproductive ability without improving life expectancy. When host access and protein availability are delayed, the rate of reproductive senescence is reduced in the medfly, whereas the rate of reproductive senescence is generally increased in the melon fly. Overall, delaying reproduction lowers the fitness of females by constraining their fecundity for the remainder of the lifespan without extending the lifespan. PMID:23483775

Synchronization Control of Neural Networks With State-Dependent Coefficient Matrices.

PubMed

Zhang, Junfeng; Zhao, Xudong; Huang, Jun

2016-11-01

This brief is concerned with synchronization control of a class of neural networks with state-dependent coefficient matrices. Being different from the existing drive-response neural networks in the literature, a novel model of drive-response neural networks is established. The concepts of uniformly ultimately bounded (UUB) synchronization and convex hull Lyapunov function are introduced. Then, by using the convex hull Lyapunov function approach, the UUB synchronization design of the drive-response neural networks is proposed, and a delay-independent control law guaranteeing the bounded synchronization of the neural networks is constructed. All present conditions are formulated in terms of bilinear matrix inequalities. By comparison, it is shown that the neural networks obtained in this brief are less conservative than those ones in the literature, and the bounded synchronization is suitable for the novel drive-response neural networks. Finally, an illustrative example is given to verify the validity of the obtained results.

Jewelry Portraits

ERIC Educational Resources Information Center

Fresia, Aimee

2010-01-01

The author is always on the lookout for new ideas, and found one with her state's new "grade-level expectations" in art. She had printed the expectations from the state department and bound them in book form for herself and other art teachers in her district. When the author was flipping through the booklet thinking, two things caught her eye:…

Coherent control of the formation of cold heteronuclear molecules by photoassociation

NASA Astrophysics Data System (ADS)

de Lima, Emanuel F.

2017-01-01

We consider the formation of cold diatomic molecules in the electronic ground state by photoassociation of atoms of dissimilar species. A combination of two transition pathways from the free colliding pair of atoms to a bound vibrational level of the electronic molecular ground state is envisioned. The first pathway consists of a pump-dump scheme with two time-delayed laser pulses in the near-infrared frequency domain. The pump pulse drives the transition to a bound vibrational level of an excited electronic state, while the dump pulse transfers the population to a bound vibrational level of the electronic ground state. The second pathway takes advantage of the existing permanent dipole moment and employs a single pulse in the far-infrared domain to drive the transition from the unbound atoms directly to a bound vibrational level in the electronic ground state. We show that this scheme offers the possibility to coherently control the photoassociation yield by manipulating the relative phase and timing of the pulses. The photoassociation mechanism is illustrated for the formation of cold LiCs molecules.

Apparent enrichment of organically bound tritium in rivers explained by the heritage of our past.

PubMed

Eyrolle-Boyer, Frédérique; Boyer, Patrick; Claval, David; Charmasson, Sabine; Cossonnet, Catherine

2014-10-01

The global inventory of naturally produced tritium (3H) is estimated at 2.65 kg, whereas more than 600 kg have been released during atmospheric nuclear tests (NCRP, 1979; UNSCEAR, 2000) constituting the main source of artificial tritium throughout the Anthropocene. The behaviour of this radioactive isotope in the environment has been widely studied since the 1950s, both through laboratory experiments and, more recently, through field observations (e.g., Cline, 1953; Kirchmann et al., 1979; Daillant et al., 2004; McCubbin et al., 2001; Kim et al., 2012). In its "free" forms, [i.e. 3H gas or 3H hydride (HT); methyl 3H gas (CH3T); tritiated H2O or 3H-oxide (HTO); and Tissue Free Water 3H (TFWT)], tritium closely follows the water cycle. However, 3H bound with organic compounds, mainly during the basic stages of photosynthesis or through weak hydrogen links, is less exchangeable with water, which explains its persistence in the carbon cycle as re underlined recently by Baglan et al. (2013), Jean-Batiste and Fourré (2013), Kim et al. (2013a,b). In this paper, we demonstrate that terrestrial biomass pools, historically contaminated by global atmospheric fallout from nuclear testing, have constituted a significant delayed source of organically bound tritium (OBT) for aquatic systems, resulting in an apparent enrichment of OBT as compared to HTO. This finding helps to explain concentration factors (tritium concentration in biota/concentration in water) greater than 1 observed in areas that are not directly affected by industrial radioactive wastes, and thus sheds light on the controversies regarding tritium 'bioaccumulation'. Such apparent enrichment of OBT is expected to be more pronounced in the Northern Hemisphere where fallout was most significant, depending on the nature and biodegradability of terrestrial biomass at the regional scale. We further believe that OBT transfers from the continent to oceans have been sufficient to affect tritium concentrations in coastal marine biota (i.e., near river inputs). Our findings demonstrate that the persistence of terrestrial organic (3)H explains imbalances between organically bound tritium and free (3)H in most river systems in particular those not impacted by releases from nuclear facilities. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bound states of moving potential wells in discrete wave mechanics

NASA Astrophysics Data System (ADS)

Longhi, S.

2017-10-01

Discrete wave mechanics describes the evolution of classical or matter waves on a lattice, which is governed by a discretized version of the Schrödinger equation. While for a vanishing lattice spacing wave evolution of the continuous Schrödinger equation is retrieved, spatial discretization and lattice effects can deeply modify wave dynamics. Here we discuss implications of breakdown of exact Galilean invariance of the discrete Schrödinger equation on the bound states sustained by a smooth potential well which is uniformly moving on the lattice with a drift velocity v. While in the continuous limit the number of bound states does not depend on the drift velocity v, as one expects from the covariance of ordinary Schrödinger equation for a Galilean boost, lattice effects can lead to a larger number of bound states for the moving potential well as compared to the potential well at rest. Moreover, for a moving potential bound states on a lattice become rather generally quasi-bound (resonance) states.

Person perception and the bounded rationality of social judgment.

PubMed

Wright, J C; Dawson, V L

1988-11-01

In this article, we develop a bounded rationality view of the relation between person perception and social behavior. Two theses of this approach are that behaviors vary in their significance to observers, and that observers pursue bounded rather than global utility in forming personality impressions. Observers are expected to be sensitive to targets' overall behavioral tendencies and to the variability of their behavior across situations, but both sensitivities are bounded, being greater for behaviors that directly affect observers' outcomes. In two investigations involving extensive hourly and 6-s observations, we examined the bounded utility of people's impressions of personality, demonstrating how impression accuracy is linked to the significance of behaviors. Observers were sensitive to the organization of aggressive behaviors, but less sensitive to the organization of withdrawn behaviors, even when the consistency of those behaviors was comparable. The results clarify the relation between people's inferential shortcomings in laboratory paradigms and the bounded utility of person perception in the natural environment.

Bound-Electron Nonlinearity Beyond the Ionization Threshold.

PubMed

Wahlstrand, J K; Zahedpour, S; Bahl, A; Kolesik, M; Milchberg, H M

2018-05-04

We present absolute space- and time-resolved measurements of the ultrafast laser-driven nonlinear polarizability in argon, krypton, xenon, nitrogen, and oxygen up to ionization fractions of a few percent. These measurements enable determination of the strongly nonperturbative bound-electron nonlinear polarizability well beyond the ionization threshold, where it is found to remain approximately quadratic in the laser field, a result normally expected at much lower intensities where perturbation theory applies.

Bound-Electron Nonlinearity Beyond the Ionization Threshold

NASA Astrophysics Data System (ADS)

Wahlstrand, J. K.; Zahedpour, S.; Bahl, A.; Kolesik, M.; Milchberg, H. M.

2018-05-01

We present absolute space- and time-resolved measurements of the ultrafast laser-driven nonlinear polarizability in argon, krypton, xenon, nitrogen, and oxygen up to ionization fractions of a few percent. These measurements enable determination of the strongly nonperturbative bound-electron nonlinear polarizability well beyond the ionization threshold, where it is found to remain approximately quadratic in the laser field, a result normally expected at much lower intensities where perturbation theory applies.

Neutrino mass implications for muon decay parameters

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

Erwin, Rebecca J.; Kile, Jennifer; Ramsey-Musolf, Michael J.

2007-02-01

We use the scale of neutrino mass and naturalness considerations to obtain model-independent expectations for the magnitude of possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we obtain a complete basis of dimension four and dimension six effective operators that are invariant under the gauge symmetry of the standard model and that contribute to both muon decay and neutrino mass. We show that - in the absence of fine tuning - the most stringent neutrino-mass naturalness bounds on chirality-changing vector operators relevant to muon decay arise from one-loop operatormore » mixing. The bounds we obtain on their contributions to the Michel parameters are 2 orders of magnitude stronger than bounds previously obtained in the literature. In addition, we analyze the implications of one-loop matching considerations and find that the expectations for the size of various scalar and tensor contributions to the Michel parameters are considerably smaller than derived from previous estimates of two-loop operator mixing. We also show, however, that there exist gauge-invariant operators that generate scalar and tensor contributions to muon decay but whose flavor structure allows them to evade neutrino-mass naturalness bounds. We discuss the implications of our analysis for the interpretation of muon-decay experiments.« less

Time delays in flight simulator visual displays

NASA Technical Reports Server (NTRS)

Crane, D. F.

1980-01-01

It is pointed out that the effects of delays of less than 100 msec in visual displays on pilot dynamic response and system performance are of particular interest at this time because improvements in the latest computer-generated imagery (CGI) systems are expected to reduce CGI displays delays to this range. Attention is given to data which quantify the effects of display delays in the range of 0-100 msec on system stability and performance, and pilot dynamic response for a particular choice of aircraft dynamics, display, controller, and task. The conventional control system design methods are reviewed, the pilot response data presented, and data for long delays, all suggest lead filter compensation of display delay. Pilot-aircraft system crossover frequency information guides compensation filter specification.

New bounding and decomposition approaches for MILP investment problems: Multi-area transmission and generation planning under policy constraints

DOE PAGES

Munoz, F. D.; Hobbs, B. F.; Watson, J. -P.

2016-02-01

A novel two-phase bounding and decomposition approach to compute optimal and near-optimal solutions to large-scale mixed-integer investment planning problems is proposed and it considers a large number of operating subproblems, each of which is a convex optimization. Our motivating application is the planning of power transmission and generation in which policy constraints are designed to incentivize high amounts of intermittent generation in electric power systems. The bounding phase exploits Jensen’s inequality to define a lower bound, which we extend to stochastic programs that use expected-value constraints to enforce policy objectives. The decomposition phase, in which the bounds are tightened, improvesmore » upon the standard Benders’ algorithm by accelerating the convergence of the bounds. The lower bound is tightened by using a Jensen’s inequality-based approach to introduce an auxiliary lower bound into the Benders master problem. Upper bounds for both phases are computed using a sub-sampling approach executed on a parallel computer system. Numerical results show that only the bounding phase is necessary if loose optimality gaps are acceptable. But, the decomposition phase is required to attain optimality gaps. Moreover, use of both phases performs better, in terms of convergence speed, than attempting to solve the problem using just the bounding phase or regular Benders decomposition separately.« less

New bounding and decomposition approaches for MILP investment problems: Multi-area transmission and generation planning under policy constraints

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

Munoz, F. D.; Hobbs, B. F.; Watson, J. -P.

A novel two-phase bounding and decomposition approach to compute optimal and near-optimal solutions to large-scale mixed-integer investment planning problems is proposed and it considers a large number of operating subproblems, each of which is a convex optimization. Our motivating application is the planning of power transmission and generation in which policy constraints are designed to incentivize high amounts of intermittent generation in electric power systems. The bounding phase exploits Jensen’s inequality to define a lower bound, which we extend to stochastic programs that use expected-value constraints to enforce policy objectives. The decomposition phase, in which the bounds are tightened, improvesmore » upon the standard Benders’ algorithm by accelerating the convergence of the bounds. The lower bound is tightened by using a Jensen’s inequality-based approach to introduce an auxiliary lower bound into the Benders master problem. Upper bounds for both phases are computed using a sub-sampling approach executed on a parallel computer system. Numerical results show that only the bounding phase is necessary if loose optimality gaps are acceptable. But, the decomposition phase is required to attain optimality gaps. Moreover, use of both phases performs better, in terms of convergence speed, than attempting to solve the problem using just the bounding phase or regular Benders decomposition separately.« less

Effect of temperature on residual force enhancement in single skeletal muscle fibers.

PubMed

Lee, Eun-Jeong; Herzog, Walter

2008-08-28

It is well accepted that the steady-state isometric force following active stretching of a muscle is greater than the steady-state isometric force obtained in a purely isometric contraction at the same length. This property of skeletal muscle has been called residual force enhancement (FE). Despite decades of research the mechanisms responsible for FE have remained largely unknown. Based on previous studies showing increases in FE in fibers in which cross-bridges were biased towards weakly bound states, we hypothesized that FE might be associated with a stretch-induced facilitation of transitioning from weakly to strongly bound cross-bridges. In order to test this hypothesis, single fibers (n=11) from the lumbrical muscles of frog (Rana pipiens) were used to determine FE at temperatures of 7 and 20 degrees C. At the cold temperature, cross-bridges are biased towards weakly bound states, therefore we expected FE to be greater at 7 degrees C compared to 20 degrees C. The average FE was significantly greater at 7 degrees C (11.5+/-1.1%) than at 20 degrees C (7.8+/-1.0%), as expected. The enhancement of force/stiffness was also significantly greater at the low (13.3+/-1.4%) compared to the high temperature (5.6+/-1.7%), indicating an increased conversion from weakly to strongly bound cross-bridges at the low temperature. We conclude from the results of this study that muscle preparations that are biased towards weakly bound cross-bridge states show increased FE for given stretch conditions, thereby supporting the idea that FE might be caused, in part, by a stretch-induced facilitation of the conversion of weakly to strongly bound cross-bridges.

Only Above Barrier Energy Components Contribute to Barrier Traversal Time

NASA Astrophysics Data System (ADS)

Galapon, Eric A.

2012-04-01

A time of arrival operator across a square potential barrier is constructed. The expectation value of the barrier time of arrival operator for a sufficiently localized incident wave packet is compared with the expectation value of the free particle time of arrival operator for the same wave packet. The comparison yields an expression for the expected traversal time across the barrier. It is shown that only the above barrier components of the momentum distribution of the incident wave packet contribute to the barrier traversal time, implying that below the barrier components are transmitted without delay. This is consistent with the recent experiment in attosecond ionization in helium indicating that there is no real tunneling delay time [P. Eckle , Science 322, 1525 (2008)SCIEAS0036-807510.1126/science.1163439].

[Social inequalities in health in the older population: an insight into the debate on delayed retirement age in Spain from a public health perspective].

PubMed

Martín, Unai; Domínguez-Rodríguez, Antía; Bacigalupe, Amaia

2017-12-30

To analyse the inequalities in life expectancy in the Spanish population over the age of 65 according to educational level. Cross sectional study on the Spanish population aged 65 years and over. Life expectancy and healthy life expectancy were calculated combining mortality, health and population data. People aged 65 and over with a lower educational level had shorter lives, with fewer years of good health and more years of poor health. Women lived longer, but with proportionally more years of poor health. Social inequalities in health must be considered in the current debate on delaying the age of retirement. Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

Analysis of Employee Engagement to Improve the Performance of Retail Risk Group PT Bank Mandiri

ERIC Educational Resources Information Center

Wiseto, Artody; Hubeis, Aida Vitayala; Sukandar, Dadang

2016-01-01

Nowadays, every company requires their employees have a bound sense to their company. It's called engagement. Also have that expectation, PT Bank Mandiri (Persero) Tbk, Bank with the largest assets in Indonesia. PT Bank Mandiri (Persero) Tbk expect which employee engagement can improve the performance such as financial, service, and production…

Delaying Anticancer Drug Delivery by Self-Assembly and Branching Effects of Minimalist Dendron-Drug Conjugates.

PubMed

Correard, Florian; Roy, Myriam; Terrasson, Vincent; Braguer, Diane; Estève, Marie-Anne; Gingras, Marc

2018-06-28

Self-assembly of a covalently-bound lipophilic drug to a dendronic scaffold for making organic nanoparticles is reported as a proof of concept in nanovectorization. A minimalist structural approach with a small PEG-dendron conjugated to paclitaxel (PTX), incorporating safe succinic and gallic acids, is efficient to provide the expected anticancer bioactivity, but also significantly retards and targets intracellular delivery of PTX in 2D and 3D lung cancer cell cultures. A branching effect of dendrons is crucial, when compared to linear PTX conjugates. Transmission electron microscopy (TEM) and dynamic light-scattering (DLS) studies indicate the formation of stable, low-disperse nanoparticles at 10 -5  m in H 2 0, which could also be responsible for the biological effects. An ultrasensitive LC-MS/MS method was used for the determination of intracellular PTX concentration over time, along with the survival rates of cancer cells. Similarly, cell survival assays were successfully correlated to a 3D cell culture with spheroids for mimicking tumors, when treated with PTX conjugates. Our work opens the way to a full evaluation program required for new chemical entities. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Continuous and lurching traveling pulses in neuronal networks with delay and spatially decaying connectivity

PubMed Central

Golomb, David; Ermentrout, G. Bard

1999-01-01

Propagation of discharges in cortical and thalamic systems, which is used as a probe for examining network circuitry, is studied by constructing a one-dimensional model of integrate-and-fire neurons that are coupled by excitatory synapses with delay. Each neuron fires only one spike. The velocity and stability of propagating continuous pulses are calculated analytically. Above a certain critical value of the constant delay, these pulses lose stability. Instead, lurching pulses propagate with discontinuous and periodic spatio-temporal characteristics. The parameter regime for which lurching occurs is strongly affected by the footprint (connectivity) shape; bistability may occur with a square footprint shape but not with an exponential footprint shape. For strong synaptic coupling, the velocity of both continuous and lurching pulses increases logarithmically with the synaptic coupling strength gsyn for an exponential footprint shape, and it is bounded for a step footprint shape. We conclude that the differences in velocity and shape between the front of thalamic spindle waves in vitro and cortical paroxysmal discharges stem from their different effective delay; in thalamic networks, large effective delay between inhibitory neurons arises from their effective interaction via the excitatory cells which display postinhibitory rebound. PMID:10557346

Noise interference with echo delay discrimination in bat biosonar.

PubMed

Simmons, J A

2017-11-01

Echolocating big brown bats (Eptesicus fuscus) were trained in a two-choice task to discriminate differences in the delay of electronic echoes at 1.7 ms delay (30 cm simulated range). Difference thresholds (∼45 μs) were comparable to previously published results. At selected above-threshold differences (116 and 232 μs delay), performance was measured in the presence of wideband random noise at increasing amplitudes in 10-dB steps to determine the noise level that prevented discrimination. Performance eventually failed, but the bats increased the amplitude and duration of their broadcasts to compensate for increasing noise, which allowed performance to persist at noise levels about 25 dB higher than without compensation. In the 232-μs delay discrimination condition, echo signal-to-noise ratio (2E/N 0 ) was 8-10 dB at the noise level that depressed performance to chance. Predicted echo-delay accuracy using big brown bat signals follows the Cramér-Rao bound for signal-to-noise ratios above 15 dB, but worsens below 15 dB due to side-peak ambiguity. At 2E/N 0  = 7-10 dB, predicted Cramér-Rao delay accuracy would be about 1 μs; considering side-peak ambiguity it would be about 200-300 μs. The bats' 232 μs performance reflects the intrusion of side-peak ambiguity into delay accuracy at low signal-to-noise ratios.

Computational work and time on finite machines.

NASA Technical Reports Server (NTRS)

Savage, J. E.

1972-01-01

Measures of the computational work and computational delay required by machines to compute functions are given. Exchange inequalities are developed for random access, tape, and drum machines to show that product inequalities between storage and time, number of drum tracks and time, number of bits in an address and time, etc., must be satisfied to compute finite functions on bounded machines.

Minimization of Delay Costs in the Realization of Production Orders in Two-Machine System

NASA Astrophysics Data System (ADS)

Dylewski, Robert; Jardzioch, Andrzej; Dworak, Oliver

2018-03-01

The article presents a new algorithm that enables the allocation of the optimal scheduling of the production orders in the two-machine system based on the minimum cost of order delays. The formulated algorithm uses the method of branch and bounds and it is a particular generalisation of the algorithm enabling for the determination of the sequence of the production orders with the minimal sum of the delays. In order to illustrate the proposed algorithm in the best way, the article contains examples accompanied by the graphical trees of solutions. The research analysing the utility of the said algorithm was conducted. The achieved results proved the usefulness of the proposed algorithm when applied to scheduling of orders. The formulated algorithm was implemented in the Matlab programme. In addition, the studies for different sets of production orders were conducted.

Constrained off-line synthesis approach of model predictive control for networked control systems with network-induced delays.

PubMed

Tang, Xiaoming; Qu, Hongchun; Wang, Ping; Zhao, Meng

2015-03-01

This paper investigates the off-line synthesis approach of model predictive control (MPC) for a class of networked control systems (NCSs) with network-induced delays. A new augmented model which can be readily applied to time-varying control law, is proposed to describe the NCS where bounded deterministic network-induced delays may occur in both sensor to controller (S-A) and controller to actuator (C-A) links. Based on this augmented model, a sufficient condition of the closed-loop stability is derived by applying the Lyapunov method. The off-line synthesis approach of model predictive control is addressed using the stability results of the system, which explicitly considers the satisfaction of input and state constraints. Numerical example is given to illustrate the effectiveness of the proposed method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

A Performance Prediction Model for a Fault-Tolerant Computer During Recovery and Restoration

NASA Technical Reports Server (NTRS)

Obando, Rodrigo A.; Stoughton, John W.

1995-01-01

The modeling and design of a fault-tolerant multiprocessor system is addressed. Of interest is the behavior of the system during recovery and restoration after a fault has occurred. The multiprocessor systems are based on the Algorithm to Architecture Mapping Model (ATAMM) and the fault considered is the death of a processor. The developed model is useful in the determination of performance bounds of the system during recovery and restoration. The performance bounds include time to recover from the fault, time to restore the system, and determination of any permanent delay in the input to output latency after the system has regained steady state. Implementation of an ATAMM based computer was developed for a four-processor generic VHSIC spaceborne computer (GVSC) as the target system. A simulation of the GVSC was also written on the code used in the ATAMM Multicomputer Operating System (AMOS). The simulation is used to verify the new model for tracking the propagation of the delay through the system and predicting the behavior of the transient state of recovery and restoration. The model is shown to accurately predict the transient behavior of an ATAMM based multicomputer during recovery and restoration.

EDDA: An Efficient Distributed Data Replication Algorithm in VANETs.

PubMed

Zhu, Junyu; Huang, Chuanhe; Fan, Xiying; Guo, Sipei; Fu, Bin

2018-02-10

Efficient data dissemination in vehicular ad hoc networks (VANETs) is a challenging issue due to the dynamic nature of the network. To improve the performance of data dissemination, we study distributed data replication algorithms in VANETs for exchanging information and computing in an arbitrarily-connected network of vehicle nodes. To achieve low dissemination delay and improve the network performance, we control the number of message copies that can be disseminated in the network and then propose an efficient distributed data replication algorithm (EDDA). The key idea is to let the data carrier distribute the data dissemination tasks to multiple nodes to speed up the dissemination process. We calculate the number of communication stages for the network to enter into a balanced status and show that the proposed distributed algorithm can converge to a consensus in a small number of communication stages. Most of the theoretical results described in this paper are to study the complexity of network convergence. The lower bound and upper bound are also provided in the analysis of the algorithm. Simulation results show that the proposed EDDA can efficiently disseminate messages to vehicles in a specific area with low dissemination delay and system overhead.

EDDA: An Efficient Distributed Data Replication Algorithm in VANETs

PubMed Central

Zhu, Junyu; Huang, Chuanhe; Fan, Xiying; Guo, Sipei; Fu, Bin

2018-01-01

Efficient data dissemination in vehicular ad hoc networks (VANETs) is a challenging issue due to the dynamic nature of the network. To improve the performance of data dissemination, we study distributed data replication algorithms in VANETs for exchanging information and computing in an arbitrarily-connected network of vehicle nodes. To achieve low dissemination delay and improve the network performance, we control the number of message copies that can be disseminated in the network and then propose an efficient distributed data replication algorithm (EDDA). The key idea is to let the data carrier distribute the data dissemination tasks to multiple nodes to speed up the dissemination process. We calculate the number of communication stages for the network to enter into a balanced status and show that the proposed distributed algorithm can converge to a consensus in a small number of communication stages. Most of the theoretical results described in this paper are to study the complexity of network convergence. The lower bound and upper bound are also provided in the analysis of the algorithm. Simulation results show that the proposed EDDA can efficiently disseminate messages to vehicles in a specific area with low dissemination delay and system overhead. PMID:29439443

A Distance Bounding Protocol for Location-Cloaked Applications.

PubMed

Molina-Martínez, Cristián; Galdames, Patricio; Duran-Faundez, Cristian

2018-04-26

Location-based services (LBSs) assume that users are willing to release trustworthy and useful details about their whereabouts. However, many location privacy concerns have arisen. For location privacy protection, several algorithms build a cloaking region to hide a user’s location. However, many applications may not operate adequately on cloaked locations. For example, a traditional distance bounding protocol (DBP)—which is run by two nodes called the prover and the verifier—may conclude an untight and useless distance between these two entities. An LBS (verifier) may use this distance as a metric of usefulness and trustworthiness of the location claimed by the user (prover). However, we show that if a tight distance is desired, traditional DBP can refine a user’s cloaked location and compromise its location privacy. To find a proper balance, we propose a location-privacy-aware DBP protocol. Our solution consists of adding some small delays before submitting any user’s response. We show that several issues arise when a certain delay is chosen, and we propose some solutions. The effectiveness of our techniques in balancing location refinement and utility is demonstrated through simulation.

Bound states for magic state distillation in fault-tolerant quantum computation.

PubMed

Campbell, Earl T; Browne, Dan E

2010-01-22

Magic state distillation is an important primitive in fault-tolerant quantum computation. The magic states are pure nonstabilizer states which can be distilled from certain mixed nonstabilizer states via Clifford group operations alone. Because of the Gottesman-Knill theorem, mixtures of Pauli eigenstates are not expected to be magic state distillable, but it has been an open question whether all mixed states outside this set may be distilled. In this Letter we show that, when resources are finitely limited, nondistillable states exist outside the stabilizer octahedron. In analogy with the bound entangled states, which arise in entanglement theory, we call such states bound states for magic state distillation.

Upper Bounds on the Expected Value of a Convex Function Using Gradient and Conjugate Function Information.

DTIC Science & Technology

1987-08-01

of the absolute difference between the random variable and its mean.Gassmann and Ziemba 119861 provide a weaker bound that does not require...2.8284, and EX4tV) -12 EX’iX) = -42. Hence C = -2 -€t* i-4’]= I-- . 1213. £1 2 5 COMPARISONS OF BOUNDS IN IIn Gassmann and Ziemba 11986) extend an idea...solution of the foLLowing Linear program: (see Gassmann, Ziemba (1986),Theorem 1) m m m-GZ=max(XT(vi) I: z. 1=1,Z vo=x io (5.1hk i-l i=i i=1 I I where 0

What we expect is not always what we get: evidence for both the direction-of-change and the specific-stimulus hypotheses of auditory attentional capture.

PubMed

Nöstl, Anatole; Marsh, John E; Sörqvist, Patrik

2014-01-01

Participants were requested to respond to a sequence of visual targets while listening to a well-known lullaby. One of the notes in the lullaby was occasionally exchanged with a pattern deviant. Experiment 1 found that deviants capture attention as a function of the pitch difference between the deviant and the replaced/expected tone. However, when the pitch difference between the expected tone and the deviant tone is held constant, a violation to the direction-of-pitch change across tones can also capture attention (Experiment 2). Moreover, in more complex auditory environments, wherein it is difficult to build a coherent neural model of the sound environment from which expectations are formed, deviations can capture attention but it appears to matter less whether this is a violation from a specific stimulus or a violation of the current direction-of-change (Experiment 3). The results support the expectation violation account of auditory distraction and suggest that there are at least two different expectations that can be violated: One appears to be bound to a specific stimulus and the other would seem to be bound to a more global cross-stimulus rule such as the direction-of-change based on a sequence of preceding sound events. Factors like base-rate probability of tones within the sound environment might become the driving mechanism of attentional capture--rather than violated expectations--in complex sound environments.

Prospection and emotional memory: how expectation affects emotional memory formation following sleep and wake

PubMed Central

Cunningham, Tony J.; Chambers, Alexis M.; Payne, Jessica D.

2014-01-01

Successful prospective memory is necessarily driven by an expectation that encoded information will be relevant in the future, leading to its preferential placement in memory storage. Like expectation, emotional salience is another type of cue that benefits human memory formation. Although separate lines of research suggest that both emotional information and information explicitly expected to be important in the future benefit memory consolidation, it is unknown how expectation affects the processing of emotional information and whether sleep, which is known to maximize memory consolidation, plays a critical role. The purpose of this study was to investigate how expectation would impact the consolidation of emotionally salient content, and whether this impact would differ across delays of sleep and wake. Participants encoded scenes containing an emotionally charged negative or neutral foreground object placed on a plausible neutral background. After encoding, half of the participants were informed they would later be tested on the scenes (expected condition), while the other half received no information about the test (unexpected condition). At recognition, following a 12-h delay of sleep or wakefulness, the scene components (objects and backgrounds) were presented separately and one at a time, and participants were asked to determine if each component was old or new. Results revealed a greater disparity for memory of negative objects over their paired neutral backgrounds for both the sleep and wake groups when the memory test was expected compared to when it was unexpected, while neutral memory remained unchanged. Analyzing each group separately, the wake group showed a threefold increase in the magnitude of this object/background trade-off for emotional scenes when the memory test was expected compared to when it was unexpected, while those who slept performed similarly across conditions. These results suggest that emotional salience and expectation cues interact to benefit emotional memory consolidation during a delay of wakefulness. The sleeping brain, however, may automatically tag emotionally salient information as important, such that explicit instruction of an upcoming memory test does not further improve memory performance. PMID:25136328

Time and Outcome Framing in Intertemporal Tradeoffs

ERIC Educational Resources Information Center

Scholten, Marc; Read, Daniel

2013-01-01

A robust anomaly in intertemporal choice is the delay-speedup asymmetry: Receipts are discounted more, and payments are discounted less, when delayed than when expedited over the same interval. We developed 2 versions of the tradeoff model (Scholten & Read, 2010) to address such situations, in which an outcome is expected at a given time but…

Minimally Invasive Radiation Biodosimetry and Evaluation of Organ Responses

DTIC Science & Technology

2016-10-01

radiation exposure, potentially leading to Acute Radiation Syndromes (ARS) and Delayed Effects of Acute ...underlying conditions and inherent variations. 2. KEYWORDS Radiation Biodosimetry, Radiation Biomarkers, microRNA, Acute Radiation Syndromes ... syndromes and delayed effects of acute radiation exposure. We expect to identify the circulating miRNA biomarkers as early predictors of late effects

Perception of Self-Efficacy, Academic Delay of Gratification, and Use of Learning Strategies among Korean College Students

ERIC Educational Resources Information Center

Bembenutty, Hefer

2004-01-01

The purpose of the present study was to examine the association between students' self-efficacy beliefs, satisfaction with their academic performance, expected grade, willingness to delay gratification, use of volitional strategies, and final course grade among Korean college students. The results support the hypothesized relationship between…

A Performance Prediction Model for a Fault-Tolerant Computer During Recovery and Restoration. Ph.D. Thesis Report, 1 Jan. - 31 Dec. 1992

NASA Technical Reports Server (NTRS)

Stoughton, John W.; Obando, Rodrigo A.

1993-01-01

The modeling and design of a fault-tolerant multiprocessor system is addressed. In particular, the behavior of the system during recovery and restoration after a fault has occurred is investigated. Given that a multicomputer system is designed using the Algorithm to Architecture to Mapping Model (ATAMM), and that a fault (death of a computing resource) occurs during its normal steady-state operation, a model is presented as a viable research tool for predicting the performance bounds of the system during its recovery and restoration phases. Furthermore, the bounds of the performance behavior of the system during this transient mode can be assessed. These bounds include: time to recover from the fault (t(sub rec)), time to restore the system (t(sub rec)) and whether there is a permanent delay in the system's Time Between Input and Output (TBIO) after the system has reached a steady state. An implementation of an ATAMM based computer was developed with the Generic VHSIC Spaceborne Computer (GVSC) as the target system. A simulation of the GVSC was also written based on the code used in ATAMM Multicomputer Operating System (AMOS). The simulation is in turn used to validate the new model in the usefulness and accuracy in tracking the propagation of the delay through the system and predicting the behavior in the transient state of recovery and restoration. The model is validated as an accurate method to predict the transient behavior of an ATAMM based multicomputer during recovery and restoration.

Robust master-slave synchronization for general uncertain delayed dynamical model based on adaptive control scheme.

PubMed

Wang, Tianbo; Zhou, Wuneng; Zhao, Shouwei; Yu, Weiqin

2014-03-01

In this paper, the robust exponential synchronization problem for a class of uncertain delayed master-slave dynamical system is investigated by using the adaptive control method. Different from some existing master-slave models, the considered master-slave system includes bounded unmodeled dynamics. In order to compensate the effect of unmodeled dynamics and effectively achieve synchronization, a novel adaptive controller with simple updated laws is proposed. Moreover, the results are given in terms of LMIs, which can be easily solved by LMI Toolbox in Matlab. A numerical example is given to illustrate the effectiveness of the method. Copyright © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

Precise estimation of tropospheric path delays with GPS techniques

NASA Technical Reports Server (NTRS)

Lichten, S. M.

1990-01-01

Tropospheric path delays are a major source of error in deep space tracking. However, the tropospheric-induced delay at tracking sites can be calibrated using measurements of Global Positioning System (GPS) satellites. A series of experiments has demonstrated the high sensitivity of GPS to tropospheric delays. A variety of tests and comparisons indicates that current accuracy of the GPS zenith tropospheric delay estimates is better than 1-cm root-mean-square over many hours, sampled continuously at intervals of six minutes. These results are consistent with expectations from covariance analyses. The covariance analyses also indicate that by the mid-1990s, when the GPS constellation is complete and the Deep Space Network is equipped with advanced GPS receivers, zenith tropospheric delay accuracy with GPS will improve further to 0.5 cm or better.

Neurocognitive outcomes in congenital diaphragmatic hernia survivors: a cross-sectional prospective study.

PubMed

Bojanić, Katarina; Grubić, Marina; Bogdanić, Ana; Vuković, Jurica; Weingarten, Toby N; Huebner, Andrea R; Sprung, Juraj; Schroeder, Darrell R; Grizelj, Ruža

2016-10-01

Congenital diaphragmatic hernia (CDH) survivors may have persistent neurocognitive delays. We assessed neurodevelopmental outcomes in CDH survivors from infancy to late teenage years. A cross-sectional study was conducted on 37 CDH survivors to examine neurocognitive functioning. Overall cognitive score was tested with the early learning composite (ELC) of Mullen Scales of Early Learning (n=19), and Full Scale IQ (FSIQ) of Wechsler Intelligence Scale for Children-Fourth Edition (n=18). ELC was 85.7±16.4, lower than the expected norm of 100, P=0.004, and 6 survivors had moderate, and 3 severe delay, which is not greater than expected in the general population (P=0.148). FSIQ was 99.6±19.1, consistent with the expected norm of 100, P=0.922, and 3 survivors had moderate and 2 severe delay, which is greater than expected (P=0.048). Although ELC was lower than FSIQ (P=0.024), within each testing group overall cognitive ability was not associated with participant age (ELC, P=0.732; FSIQ, P=0.909). Longer hospital stay was the only factor found to be consistently associated with a worse cognitive score across all participants in our cohort. A high percentage of survivors with CDH have moderate to severe cognitive impairment suggesting that these subjects warrant early testing with implementation of therapeutic and educational interventions. Published by Elsevier Inc.

[Evaluation of the effect of varicella outbreak control measures through a discrete time delay SEIR model].

PubMed

Pan, Jin-ren; Huang, Zheng-qiang; Chen, Kun

2012-04-01

forecast the epidemic trend and to evaluate the effect of outbreak control measures by investigation of a varicella outbreak event with a discrete time delay SEIR model. A discrete time delay model was formulated by discretization method based on a continuous SEIR model with the consideration of the time delay effect on latent period and communicable period. The epidemic trend forecast was carried out based on the number of expected cases. The theoretical effect evaluation was assessed by comparing the results from different emergency control measures. Without any control measures, the theoretical attack rate was 30.16% (504/1671). The course of the epidemic lasted for 4 months and the peak epidemic time was 78 days after the onset of the first case. 'Generation' phenomenon had been observed in the course of the epidemic with the interval of two weeks. The actual number of cases was decreased by 89.48% (451/504) compared with the number of expected cases under no control measure scenario. With the rigorous quarantine measure for all cases on their onset day, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 22, 59, 127 and 220 respectively. With the quarantine measure conducted on 14 days after the onset of the first case, when the proportion of quarantine was 30%, 50%, 70%, 90%, the total number of expected cases were 485, 457, 386 and 169, respectively. With the emergent vaccination for all persons, when the measure was conducted on 0, 14, 28, 42 days after the onset of the first case, the total numbers of expected cases were 7, 26, 81 and 202 respectively. With the emergent vaccination conducted on 14 days after the onset of the first case, when the immunization coverage rate was 30%, 50%, 70%, 90%, the total numbers of expected cases were 354, 246, 127 and 40, respectively. The number of expected cases can be regarded as the reference to evaluate the effect of control measures. The simulation results suggest that it will get more benefits to conduct control measures earlier in varicella outbreak events, and the effect of emergent vaccination is better than that of quarantine measure under the same conditions.

Improving the quality of vascular surgical discharge planning in a hub centre.

PubMed

Wariyapola, C; Littlehales, E; Abayasekara, K; Fall, D; Parker, V; Hatton, G

2016-04-01

Introduction Discharge planning improves patient outcomes, reduces hospital stay and readmission rates, and should involve a multidisciplinary team (MDT) approach. The efficacy of MDT meetings in discharge planning was examined, as well as reasons for delayed discharge among vascular surgical inpatients. Methods Dedicated weekly MDT meetings were held on the vascular ward in Royal Derby Hospital for three months. Each patient was presented to the discharge planning meeting and an expected date of discharge was decided prospectively. Patients who were discharged after this date were considered 'delayed' and reasons for delay were explored at the next meeting. Results Overall, 193 patients were included in the study. Of these, 42 patients (22%) had a delayed discharge while 29 (15%) had an early discharge. The main reasons for delay were awaiting beds (30%), social (14%) and medical (45%). In 64%, the cause for delay was avoidable. Two-thirds (67%) of all delays were >24 hours. This totalled 115 bed days, of which 67 could have been avoided. However, 32 bed days were saved by early discharge. This equates to a net loss of 35 bed days, at a net cost of £2,936 per month or £35,235 per year. The MDT meetings also improved the quality of discharge planning; the variability between expected and actual discharge dates decreased after the first month. Conclusions Discharge planning meetings help prepare for patient discharge and are most effective with multidisciplinary input. The majority of delayed discharges from hospital are preventable. The main causes are awaiting transfers, social services input and medical reasons (eg falls). There is an obvious financial incentive to improve discharge planning. The efficiency of the MDT at discharge planning improves with time and this should therefore be continued for best results.

Approximation-Based Adaptive Neural Tracking Control of Nonlinear MIMO Unknown Time-Varying Delay Systems With Full State Constraints.

PubMed

Li, Da-Peng; Li, Dong-Juan; Liu, Yan-Jun; Tong, Shaocheng; Chen, C L Philip

2017-10-01

This paper deals with the tracking control problem for a class of nonlinear multiple input multiple output unknown time-varying delay systems with full state constraints. To overcome the challenges which cause by the appearances of the unknown time-varying delays and full-state constraints simultaneously in the systems, an adaptive control method is presented for such systems for the first time. The appropriate Lyapunov-Krasovskii functions and a separation technique are employed to eliminate the effect of unknown time-varying delays. The barrier Lyapunov functions are employed to prevent the violation of the full state constraints. The singular problems are dealt with by introducing the signal function. Finally, it is proven that the proposed method can both guarantee the good tracking performance of the systems output, all states are remained in the constrained interval and all the closed-loop signals are bounded in the design process based on choosing appropriate design parameters. The practicability of the proposed control technique is demonstrated by a simulation study in this paper.

The Communication Expectations of College-Bound High School Students. An E-Expectations Trend Report

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2012

2012-01-01

How do prospective college students want to communicate with campuses? When do they want to interact with their target colleges? Which communication methods make them feel most comfortable? Noel-Levitz, OmniUpdate, CollegeWeekLive, and NRCCUA[R] (National Research Center for College & University Admissions) conducted a survey of more than 1,300…

Runway Scheduling Using Generalized Dynamic Programming

NASA Technical Reports Server (NTRS)

Montoya, Justin; Wood, Zachary; Rathinam, Sivakumar

2011-01-01

A generalized dynamic programming method for finding a set of pareto optimal solutions for a runway scheduling problem is introduced. The algorithm generates a set of runway fight sequences that are optimal for both runway throughput and delay. Realistic time-based operational constraints are considered, including miles-in-trail separation, runway crossings, and wake vortex separation. The authors also model divergent runway takeoff operations to allow for reduced wake vortex separation. A modeled Dallas/Fort Worth International airport and three baseline heuristics are used to illustrate preliminary benefits of using the generalized dynamic programming method. Simulated traffic levels ranged from 10 aircraft to 30 aircraft with each test case spanning 15 minutes. The optimal solution shows a 40-70 percent decrease in the expected delay per aircraft over the baseline schedulers. Computational results suggest that the algorithm is promising for real-time application with an average computation time of 4.5 seconds. For even faster computation times, two heuristics are developed. As compared to the optimal, the heuristics are within 5% of the expected delay per aircraft and 1% of the expected number of runway operations per hour ad can be 100x faster.

Thermalization Time Bounds for Pauli Stabilizer Hamiltonians

NASA Astrophysics Data System (ADS)

Temme, Kristan

2017-03-01

We prove a general lower bound to the spectral gap of the Davies generator for Hamiltonians that can be written as the sum of commuting Pauli operators. These Hamiltonians, defined on the Hilbert space of N-qubits, serve as one of the most frequently considered candidates for a self-correcting quantum memory. A spectral gap bound on the Davies generator establishes an upper limit on the life time of such a quantum memory and can be used to estimate the time until the system relaxes to thermal equilibrium when brought into contact with a thermal heat bath. The bound can be shown to behave as {λ ≥ O(N^{-1} exp(-2β overline{ɛ}))}, where {overline{ɛ}} is a generalization of the well known energy barrier for logical operators. Particularly in the low temperature regime we expect this bound to provide the correct asymptotic scaling of the gap with the system size up to a factor of N -1. Furthermore, we discuss conditions and provide scenarios where this factor can be removed and a constant lower bound can be proven.

Germination-defective mutant of Neurospora crassa that responds to siderophores

NASA Technical Reports Server (NTRS)

Charlang, G.; Williams, N. P.

1977-01-01

A conditionally germination-defective mutant of Neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. The mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. Germination is consequently delayed unless large numbers of conidia are present (positive population effect). This indicates that the mutant has a membrane defect involving the siderophore attachment site.

Analysis of a grid ionospheric vertical delay and its bounding errors over West African sub-Saharan region

NASA Astrophysics Data System (ADS)

Abe, O. E.; Otero Villamide, X.; Paparini, C.; Radicella, S. M.; Nava, B.

2017-02-01

Investigating the effects of the Equatorial Ionization Anomaly (EIA) ionosphere and space weather on Global Navigation Satellite Systems (GNSS) is very crucial, and a key to successful implementation of a GNSS augmentation system (SBAS) over the equatorial and low-latitude regions. A possible ionospheric vertical delay (GIVD, Grid Ionospheric Vertical Delay) broadcast at a Ionospheric Grid Point (IGP) and its confidence bounds errors (GIVE, Grid Ionospheric Vertical Error) are analyzed and compared with the ionospheric vertical delay estimated at a nearby user location over the West African Sub-Saharan region. Since African sub-Saharan ionosphere falls within the EIA region, which is always characterized by a disturbance in form of irregularities after sunset, and the disturbance is even more during the geomagnetically quiet conditions unlike middle latitudes, the need to have a reliable ionospheric threat model to cater for the nighttime ionospheric plasma irregularities for the future SBAS user is essential. The study was done during the most quiet and disturbed geomagnetic conditions on October 2013. A specific low latitude EGNOS-like algorithm, based on single thin layer model, was engaged to simulate SBAS message in the study. Our preliminary results indicate that, the estimated GIVE detects and protects a potential SBAS user against sampled ionospheric plasma irregularities over the region with a steep increment in GIVE to non-monitored after local sunset to post midnight. This corresponds to the onset of the usual ionospheric plasma irregularities in the region. The results further confirm that the effects of the geomagnetic storms on the ionosphere are not consistent in affecting GNSS applications over the region. Finally, this paper suggests further work to be investigated in order to improve the threat integrity model activity, and thereby enhance the availability of the future SBAS over African sub-Saharan region.

STATIC QUARK ANTI-QUARK FREE AND INTERNAL ENERGY IN 2-FLAVOR QCD AND BOUND STATES IN THE QGP.

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

ZANTOW, F.; KACZMAREK, O.

2005-07-25

We present results on heavy quark free energies in 2-flavour QCD. The temperature dependence of the interaction between static quark anti-quark pairs will be analyzed in terms of temperature dependent screening radii, which give a first estimate on the medium modification of (heavy quark) bound states in the quark gluon plasma. Comparing those radii to the (zero temperature) mean squared charge radii of chasmonium states indicates that the J/{Psi} may survive the phase transition as a bound state, while {chi}{sub c} and {Psi}{prime} are expected to show significant thermal modifications at temperatures close to the transition. Furthermore we will analyzemore » the relation between heavy quark free energies, entropy contributions and internal energy and discuss their relation to potential models used to analyze the melting of heavy quark bound states above the deconfinement temperature. Results of different groups and various potential models for bound states in the deconfined phase of QCD are compared.« less

Reduced order modelling in searches for continuous gravitational waves - I. Barycentring time delays

NASA Astrophysics Data System (ADS)

Pitkin, M.; Doolan, S.; McMenamin, L.; Wette, K.

2018-06-01

The frequencies and phases of emission from extra-solar sources measured by Earth-bound observers are modulated by the motions of the observer with respect to the source, and through relativistic effects. These modulations depend critically on the source's sky-location. Precise knowledge of the modulations are required to coherently track the source's phase over long observations, for example, in pulsar timing, or searches for continuous gravitational waves. The modulations can be modelled as sky-location and time-dependent time delays that convert arrival times at the observer to the inertial frame of the source, which can often be the Solar system barycentre. We study the use of reduced order modelling for speeding up the calculation of this time delay for any sky-location. We find that the time delay model can be decomposed into just four basis vectors, and with these the delay for any sky-location can be reconstructed to sub-nanosecond accuracy. When compared to standard routines for time delay calculation in gravitational wave searches, using the reduced basis can lead to speed-ups of 30 times. We have also studied components of time delays for sources in binary systems. Assuming eccentricities <0.25, we can reconstruct the delays to within 100 s of nanoseconds, with best case speed-ups of a factor of 10, or factors of two when interpolating the basis for different orbital periods or time stamps. In long-duration phase-coherent searches for sources with sky-position uncertainties, or binary parameter uncertainties, these speed-ups could allow enhancements in their scopes without large additional computational burdens.

Disfluent Responses to Job Interview Questions and What They Entail

ERIC Educational Resources Information Center

Brosy, Julie; Bangerter, Adrian; Mayor, Eric

2016-01-01

Conversation is governed by expectations of timely responding. Violations of these expectations are grounds for inference by other participants. These inferences may be at odds with identities respondents try to project. In job interviews, candidates' responses are used to make hiring decisions. Candidates trade off between (1) delaying response…

Stochastic Network Interdiction

DTIC Science & Technology

1998-04-01

UB(6, g) are monotonic in the sense that if 69 is a refinement of 6: wI~6! < wI~69! and w# ~6, g! > w# ~69, g!. See Hausch and Ziemba (1983) for...of Vulnerability—The Integrity Family. Networks 24, 207–213. HAUSCH, D. B., AND W. T. ZIEMBA . 1983. Bounds on the Value of Information in Uncertain...Decision Problems II. Stochastics 10, 181–217. HUANG, C. C., W. T. ZIEMBA , AND A. BEN-TAL. 1977. Bounds on the Expectation of a Convex Function of a

Neural-adaptive control of single-master-multiple-slaves teleoperation for coordinated multiple mobile manipulators with time-varying communication delays and input uncertainties.

PubMed

Li, Zhijun; Su, Chun-Yi

2013-09-01

In this paper, adaptive neural network control is investigated for single-master-multiple-slaves teleoperation in consideration of time delays and input dead-zone uncertainties for multiple mobile manipulators carrying a common object in a cooperative manner. Firstly, concise dynamics of teleoperation systems consisting of a single master robot, multiple coordinated slave robots, and the object are developed in the task space. To handle asymmetric time-varying delays in communication channels and unknown asymmetric input dead zones, the nonlinear dynamics of the teleoperation system are transformed into two subsystems through feedback linearization: local master or slave dynamics including the unknown input dead zones and delayed dynamics for the purpose of synchronization. Then, a model reference neural network control strategy based on linear matrix inequalities (LMI) and adaptive techniques is proposed. The developed control approach ensures that the defined tracking errors converge to zero whereas the coordination internal force errors remain bounded and can be made arbitrarily small. Throughout this paper, stability analysis is performed via explicit Lyapunov techniques under specific LMI conditions. The proposed adaptive neural network control scheme is robust against motion disturbances, parametric uncertainties, time-varying delays, and input dead zones, which is validated by simulation studies.

New exponential stability criteria for stochastic BAM neural networks with impulses

NASA Astrophysics Data System (ADS)

Sakthivel, R.; Samidurai, R.; Anthoni, S. M.

2010-10-01

In this paper, we study the global exponential stability of time-delayed stochastic bidirectional associative memory neural networks with impulses and Markovian jumping parameters. A generalized activation function is considered, and traditional assumptions on the boundedness, monotony and differentiability of activation functions are removed. We obtain a new set of sufficient conditions in terms of linear matrix inequalities, which ensures the global exponential stability of the unique equilibrium point for stochastic BAM neural networks with impulses. The Lyapunov function method with the Itô differential rule is employed for achieving the required result. Moreover, a numerical example is provided to show that the proposed result improves the allowable upper bound of delays over some existing results in the literature.

Factors Associated with Delayed Childbearing: From the Voices of Expectant Latina Adults and Teens in California

ERIC Educational Resources Information Center

Biggs, M. Antonia; Ralph, Lauren; Minnis, Alexandra M.; Arons, Abigail; Marchi, Kristen S.; Lehrer, Jocelyn A.; Braveman, Paula A.; Brindis, Claire D.

2010-01-01

There has been limited research on the protective factors that help Latinas delay childbearing until adulthood. In-depth interviews were conducted with 65 pregnant Latina teenage and adult women in California who were about to have their first child. Lack of or inconsistent birth control use as teens was attributed to wanting or ambivalence toward…

Resource Slack and Propensity to Discount Delayed Investments of Time Versus Money

ERIC Educational Resources Information Center

Zauberman, Gal; Lynch, John G.

2005-01-01

The authors demonstrate that people discount delayed outcomes as a result of perceived changes over time in supplies of slack. Slack is the perceived surplus of a given resource available to complete a focal task. The present research shows that, in general, people expect slack for time to be greater in the future than in the present. Typically,…

Improving the quality of vascular surgical discharge planning in a hub centre

PubMed Central

Wariyapola, C; Littlehales, E; Abayasekara, K; Fall, D; Parker, V; Hatton, G

2016-01-01

Introduction Discharge planning improves patient outcomes, reduces hospital stay and readmission rates, and should involve a multidisciplinary team (MDT) approach. The efficacy of MDT meetings in discharge planning was examined, as well as reasons for delayed discharge among vascular surgical inpatients. Methods Dedicated weekly MDT meetings were held on the vascular ward in Royal Derby Hospital for three months. Each patient was presented to the discharge planning meeting and an expected date of discharge was decided prospectively. Patients who were discharged after this date were considered ‘delayed’ and reasons for delay were explored at the next meeting. Results Overall, 193 patients were included in the study. Of these, 42 patients (22%) had a delayed discharge while 29 (15%) had an early discharge. The main reasons for delay were awaiting beds (30%), social (14%) and medical (45%). In 64%, the cause for delay was avoidable. Two-thirds (67%) of all delays were >24 hours. This totalled 115 bed days, of which 67 could have been avoided. However, 32 bed days were saved by early discharge. This equates to a net loss of 35 bed days, at a net cost of £2,936 per month or £35,235 per year. The MDT meetings also improved the quality of discharge planning; the variability between expected and actual discharge dates decreased after the first month. Conclusions Discharge planning meetings help prepare for patient discharge and are most effective with multidisciplinary input. The majority of delayed discharges from hospital are preventable. The main causes are awaiting transfers, social services input and medical reasons (eg falls). There is an obvious financial incentive to improve discharge planning. The efficiency of the MDT at discharge planning improves with time and this should therefore be continued for best results. PMID:26924480

Throughput analysis for the National Airspace System

NASA Astrophysics Data System (ADS)

Sureshkumar, Chandrasekar

The United States National Airspace System (NAS) network performance is currently measured using a variety of metrics based on delay. Developments in the fields of wireless communication, manufacturing and other modes of transportation like road, freight, etc. have explored various metrics that complement the delay metric. In this work, we develop a throughput concept for both the terminal and en-route phases of flight inspired by studies in the above areas and explore the applications of throughput metrics for the en-route airspace of the NAS. These metrics can be applied to the NAS performance at each hierarchical level—the sector, center, regional and national and will consist of multiple layers of networks with the bottom level comprising the traffic pattern modelled as a network of individual sectors acting as nodes. This hierarchical approach is especially suited for executive level decision making as it gives an overall picture of not just the inefficiencies but also the aspects where the NAS has performed well in a given situation from which specific information about the effects of a policy change on the NAS performance at each level can be determined. These metrics are further validated with real traffic data using the Future Air Traffic Management Concepts Evaluation Tool (FACET) for three en-route sectors and an Air Route Traffic Control Center (ARTCC). Further, this work proposes a framework to compute the minimum makespan and the capacity of a runway system in any configuration. Towards this, an algorithm for optimal arrival and departure flight sequencing is proposed. The proposed algorithm is based on a branch-and-bound technique and allows for the efficient computation of the best runway assignment and sequencing of arrival and departure operations that minimize the makespan at a given airport. The lower and upper bounds of the cost of each branch for the best first search in the branch-and-bound algorithm are computed based on the minimum separation standards between arrival and departure operations set by the Federal Aviation Administration. The optimal objective value is mathematically proved to lie between these bounds and the algorithm uses these bounds to efficiently find promising branches and discard all others and terminate with atleast one sequence with the minimal makespan. The proposed algorithm is analyzed and validated through real traffic operations data at the Hartsfield-Jackson Atlanta international airport.

Search for weakly decaying Λn ‾ and ΛΛ exotic bound states in central Pb-Pb collisions at √{sNN} = 2.76 TeV

NASA Astrophysics Data System (ADS)

Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, S.; Chattopadhyay, S.; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; De, S.; De Caro, A.; de Cataldo, G.; de Cuveland, J.; De Falco, A.; De Gruttola, D.; De Marco, N.; De Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; Di Bari, D.; Di Mauro, A.; Di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hilden, T. E.; Hillemanns, H.; Hippolyte, B.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jachołkowski, A.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Khan, K. H.; Khan, M. M.; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, M.; Kim, M.; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobayashi, T.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kouzinopoulos, C.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, J.; Kumar, L.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martin Blanco, J.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; Mcdonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Mulligan, J. D.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira Da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Pan, J.; Pandey, A. K.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira Da Costa, H.; Pereira De Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Seeder, K. S.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Symons, T. J. M.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tanaka, N.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; Van Der Maarel, J.; Van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yano, S.; Yasnopolskiy, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

2016-01-01

We present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possible Λn ‾ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at √{sNN} = 2.76 TeV, by invariant mass analysis in the decay modes Λn ‾ → d ‾π+ and H-dibaryon → Λpπ-. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.

Search for weakly decaying Λ n - and ΛΛ exotic bound states in central Pb–Pb collisions at s NN = 2.76  TeV

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

Adam, J.; Adamová, D.; Aggarwal, M. M.

Here, we present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possiblemore » $$\\overline{Λn}$$ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at $$\\sqrt{s}$$$_ {NN}$$ = 2.76 TeV, by invariant mass analysis in the decay modes $$\\overline{Λn}$$ → $$\\bar{d}$$π + and H-dibaryon →Λpπ -. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.« less

Search for weakly decaying Λ n - and ΛΛ exotic bound states in central Pb–Pb collisions at s NN = 2.76  TeV

DOE PAGES

Adam, J.; Adamová, D.; Aggarwal, M. M.; ...

2016-11-28

Here, we present results of a search for two hypothetical strange dibaryon states, i.e. the H-dibaryon and the possiblemore » $$\\overline{Λn}$$ bound state. The search is performed with the ALICE detector in central (0-10%) Pb-Pb collisions at $$\\sqrt{s}$$$_ {NN}$$ = 2.76 TeV, by invariant mass analysis in the decay modes $$\\overline{Λn}$$ → $$\\bar{d}$$π + and H-dibaryon →Λpπ -. No evidence for these bound states is observed. Upper limits are determined at 99% confidence level for a wide range of lifetimes and for the full range of branching ratios. The results are compared to thermal, coalescence and hybrid UrQMD model expectations, which describe correctly the production of other loosely bound states, like the deuteron and the hypertriton.« less

DARK Technology Transition Plan

DTIC Science & Technology

1990-04-01

or suspend/resume primitives , and bounded delays. Under the above circumstances, the extra language features, and the hidden system calls they... system , this implies that the mechanisms by which units interact - to synchronise , communicate, schedule one another, or alert one another - should be...the Kernel environment are: " The host system is a DEC VAX operating under VMS 5.0 (the specific host used at the SEI is a MicroVAX II operating under

Dynamic pricing of network goods with boundedly rational consumers.

PubMed

Radner, Roy; Radunskaya, Ami; Sundararajan, Arun

2014-01-07

We present a model of dynamic monopoly pricing for a good that displays network effects. In contrast with the standard notion of a rational-expectations equilibrium, we model consumers as boundedly rational and unable either to pay immediate attention to each price change or to make accurate forecasts of the adoption of the network good. Our analysis shows that the seller's optimal price trajectory has the following structure: The price is low when the user base is below a target level, is high when the user base is above the target, and is set to keep the user base stationary once the target level has been attained. We show that this pricing policy is robust to a number of extensions, which include the product's user base evolving over time and consumers basing their choices on a mixture of a myopic and a "stubborn" expectation of adoption. Our results differ significantly from those that would be predicted by a model based on rational-expectations equilibrium and are more consistent with the pricing of network goods observed in practice.

Dynamic pricing of network goods with boundedly rational consumers

PubMed Central

Radner, Roy; Radunskaya, Ami; Sundararajan, Arun

2014-01-01

We present a model of dynamic monopoly pricing for a good that displays network effects. In contrast with the standard notion of a rational-expectations equilibrium, we model consumers as boundedly rational and unable either to pay immediate attention to each price change or to make accurate forecasts of the adoption of the network good. Our analysis shows that the seller’s optimal price trajectory has the following structure: The price is low when the user base is below a target level, is high when the user base is above the target, and is set to keep the user base stationary once the target level has been attained. We show that this pricing policy is robust to a number of extensions, which include the product’s user base evolving over time and consumers basing their choices on a mixture of a myopic and a “stubborn” expectation of adoption. Our results differ significantly from those that would be predicted by a model based on rational-expectations equilibrium and are more consistent with the pricing of network goods observed in practice. PMID:24367101

Mass, height of burst, and source–receiver distance constraints on the acoustic coda phase delay method

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

Albert, Sarah; Bowman, Daniel; Rodgers, Arthur

Here, this research uses the acoustic coda phase delay method to estimate relative changes in air temperature between explosions with varying event masses and heights of burst. It also places a bound on source–receiver distance for the method. Previous studies used events with different shapes, height of bursts, and masses and recorded the acoustic codas at source–receiver distances less than 1 km. This research further explores the method using explosions that differ in mass (by up to an order of magnitude) and are placed at varying heights. Source–receiver distances also cover an area out to 7 km. Relative air temperaturemore » change estimates are compared to complementary meteorological observations. Results show that two explosions that differ by an order of magnitude cannot be used with this method because their propagation times in the near field and their fundamental frequencies are different. These differences are expressed as inaccuracies in the relative air temperature change estimates. An order of magnitude difference in mass is also shown to bias estimates higher. Small differences in height of burst do not affect the accuracy of the method. Finally, an upper bound of 1 km on source–receiver distance is provided based on the standard deviation characteristics of the estimates.« less

Mass, height of burst, and source–receiver distance constraints on the acoustic coda phase delay method

DOE PAGES

Albert, Sarah; Bowman, Daniel; Rodgers, Arthur; ...

2018-04-23

Here, this research uses the acoustic coda phase delay method to estimate relative changes in air temperature between explosions with varying event masses and heights of burst. It also places a bound on source–receiver distance for the method. Previous studies used events with different shapes, height of bursts, and masses and recorded the acoustic codas at source–receiver distances less than 1 km. This research further explores the method using explosions that differ in mass (by up to an order of magnitude) and are placed at varying heights. Source–receiver distances also cover an area out to 7 km. Relative air temperaturemore » change estimates are compared to complementary meteorological observations. Results show that two explosions that differ by an order of magnitude cannot be used with this method because their propagation times in the near field and their fundamental frequencies are different. These differences are expressed as inaccuracies in the relative air temperature change estimates. An order of magnitude difference in mass is also shown to bias estimates higher. Small differences in height of burst do not affect the accuracy of the method. Finally, an upper bound of 1 km on source–receiver distance is provided based on the standard deviation characteristics of the estimates.« less

Human middle-ear model with compound eardrum and airway branching in mastoid air cells

PubMed Central

Keefe, Douglas H.

2015-01-01

An acoustical/mechanical model of normal adult human middle-ear function is described for forward and reverse transmission. The eardrum model included one component bound along the manubrium and another bound by the tympanic cleft. Eardrum components were coupled by a time-delayed impedance. The acoustics of the middle-ear cleft was represented by an acoustical transmission-line model for the tympanic cavity, aditus, antrum, and mastoid air cell system with variable amounts of excess viscothermal loss. Model parameters were fitted to published measurements of energy reflectance (0.25–13 kHz), equivalent input impedance at the eardrum (0.25–11 kHz), temporal-bone pressure in scala vestibuli and scala tympani (0.1–11 kHz), and reverse middle-ear impedance (0.25–8 kHz). Inner-ear fluid motion included cochlear and physiological third-window pathways. The two-component eardrum with time delay helped fit intracochlear pressure responses. A multi-modal representation of the eardrum and high-frequency modeling of the middle-ear cleft helped fit ear-canal responses. Input reactance at the eardrum was small at high frequencies due to multiple modal resonances. The model predicted the middle-ear efficiency between ear canal and cochlea, and the cochlear pressures at threshold. PMID:25994701

Human middle-ear model with compound eardrum and airway branching in mastoid air cells.

PubMed

Keefe, Douglas H

2015-05-01

An acoustical/mechanical model of normal adult human middle-ear function is described for forward and reverse transmission. The eardrum model included one component bound along the manubrium and another bound by the tympanic cleft. Eardrum components were coupled by a time-delayed impedance. The acoustics of the middle-ear cleft was represented by an acoustical transmission-line model for the tympanic cavity, aditus, antrum, and mastoid air cell system with variable amounts of excess viscothermal loss. Model parameters were fitted to published measurements of energy reflectance (0.25-13 kHz), equivalent input impedance at the eardrum (0.25-11 kHz), temporal-bone pressure in scala vestibuli and scala tympani (0.1-11 kHz), and reverse middle-ear impedance (0.25-8 kHz). Inner-ear fluid motion included cochlear and physiological third-window pathways. The two-component eardrum with time delay helped fit intracochlear pressure responses. A multi-modal representation of the eardrum and high-frequency modeling of the middle-ear cleft helped fit ear-canal responses. Input reactance at the eardrum was small at high frequencies due to multiple modal resonances. The model predicted the middle-ear efficiency between ear canal and cochlea, and the cochlear pressures at threshold.

Optimizing Retransmission Threshold in Wireless Sensor Networks

PubMed Central

Bi, Ran; Li, Yingshu; Tan, Guozhen; Sun, Liang

2016-01-01

The retransmission threshold in wireless sensor networks is critical to the latency of data delivery in the networks. However, existing works on data transmission in sensor networks did not consider the optimization of the retransmission threshold, and they simply set the same retransmission threshold for all sensor nodes in advance. The method did not take link quality and delay requirement into account, which decreases the probability of a packet passing its delivery path within a given deadline. This paper investigates the problem of finding optimal retransmission thresholds for relay nodes along a delivery path in a sensor network. The object of optimizing retransmission thresholds is to maximize the summation of the probability of the packet being successfully delivered to the next relay node or destination node in time. A dynamic programming-based distributed algorithm for finding optimal retransmission thresholds for relay nodes along a delivery path in the sensor network is proposed. The time complexity is OnΔ·max1≤i≤n{ui}, where ui is the given upper bound of the retransmission threshold of sensor node i in a given delivery path, n is the length of the delivery path and Δ is the given upper bound of the transmission delay of the delivery path. If Δ is greater than the polynomial, to reduce the time complexity, a linear programming-based (1+pmin)-approximation algorithm is proposed. Furthermore, when the ranges of the upper and lower bounds of retransmission thresholds are big enough, a Lagrange multiplier-based distributed O(1)-approximation algorithm with time complexity O(1) is proposed. Experimental results show that the proposed algorithms have better performance. PMID:27171092

Cultural aspects of primary healthcare in india: A case- based analysis.

PubMed

Worthington, Roger P; Gogne, Anupriya

2011-06-16

Delivering quality primary care to large populations is always challenging, and that is certainly the case in India. While the sheer magnitude of patients can create difficulties, not all challenges are about logistics. Sometimes patient health-seeking behaviour leads to delays in obtaining medical help for reasons that have more to do with culture, social practice and religious belief. When primary care is accessed via busy state-run outpatient departments there is often little time for the physician to investigate causes behind a patient's condition, and these factors can adversely affect patient outcomes. We consider the case of a woman with somatic symptoms seemingly triggered by psychological stresses associated with social norms and familial cultural expectations. These expectations conflict with her personal and professional aspirations, and although she eventually receives psychiatric help and her problems are addressed, initially, psycho-social factors underlying her condition posed a hurdle in terms of accessing appropriate medical care. While for many people culture, belief and social norms exert a stabilising, positive influence, in situations where someone's personal expectations differ significantly from accepted social norms, individual autonomy can be directly challenged, and in which case, something has to give. The result of such challenges can negatively impact on health and well-being, and for patients with immature defence mechanisms for dealing with inner conflict, such an experience can be damaging and ensuing somatic disturbances are often difficult to treat. Patients with culture-bound symptoms are not uncommon within primary care in India or in other Asian countries and communities. We argue that such cases need to be properly understood if satisfactory patient outcomes are to be achieved. While some causes are structural, having to do with how healthcare is accessed and delivered, others are about cultural values, social practices and beliefs. We note how some young adult women are adversely affected and discuss some of the ethical issues that arise.

Cultural aspects of primary healthcare in india: A case- based analysis

PubMed Central

2011-01-01

Delivering quality primary care to large populations is always challenging, and that is certainly the case in India. While the sheer magnitude of patients can create difficulties, not all challenges are about logistics. Sometimes patient health-seeking behaviour leads to delays in obtaining medical help for reasons that have more to do with culture, social practice and religious belief. When primary care is accessed via busy state-run outpatient departments there is often little time for the physician to investigate causes behind a patient's condition, and these factors can adversely affect patient outcomes. We consider the case of a woman with somatic symptoms seemingly triggered by psychological stresses associated with social norms and familial cultural expectations. These expectations conflict with her personal and professional aspirations, and although she eventually receives psychiatric help and her problems are addressed, initially, psycho-social factors underlying her condition posed a hurdle in terms of accessing appropriate medical care. While for many people culture, belief and social norms exert a stabilising, positive influence, in situations where someone's personal expectations differ significantly from accepted social norms, individual autonomy can be directly challenged, and in which case, something has to give. The result of such challenges can negatively impact on health and well-being, and for patients with immature defence mechanisms for dealing with inner conflict, such an experience can be damaging and ensuing somatic disturbances are often difficult to treat. Patients with culture-bound symptoms are not uncommon within primary care in India or in other Asian countries and communities. We argue that such cases need to be properly understood if satisfactory patient outcomes are to be achieved. While some causes are structural, having to do with how healthcare is accessed and delivered, others are about cultural values, social practices and beliefs. We note how some young adult women are adversely affected and discuss some of the ethical issues that arise. PMID:21679415

Wigner time delay and spin-orbit activated confinement resonances

NASA Astrophysics Data System (ADS)

Keating, D. A.; Deshmukh, P. C.; Manson, S. T.

2017-09-01

A study of the photoionization of spin-orbit split subshells of high-Z atoms confined in C60 has been performed using the relativistic-random-phase approximation. Specifically, Hg@C60 5p, Rn@C60 6p and Ra@C60 5d were investigated and the near-threshold confinement resonances in the j = l - 1/2 channels were found to engender structures in the j = l + 1/2 cross sections via correlation in the form of interchannel coupling. These structures are termed spin-orbit induced confinement resonances and they are found to profoundly influence the Wigner time delay spectrum resulting in time delays of tens or hundreds of attoseconds along with dramatic swings in time delay over small energy intervals. Pronounced relativistic effects in time delay are also found. These structures, including their manifestation in time delay spectra, are expected to be general phenomena in the photoionization of spin-orbit doublets in confined high-Z atoms.

Oculomotor Capture by New and Unannounced Color Singletons during Visual Search.

PubMed

Retell, James D; Venini, Dustin; Becker, Stefanie I

2015-07-01

The surprise capture hypothesis states that a stimulus will capture attention to the extent that it is preattentively available and deviates from task-expectancies. Interestingly, it has been noted by Horstmann (Psychological Science 13: 499-505. doi: 10.1111/1467-9280.00488, 2002, Human Perception and Performance 31: 1039-1060. doi: 10.1037/00961523.31.5.1039, 2005, Psychological Research, 70, 13-25, 2006) that the time course of capture by such classes of stimuli appears distinct from that of capture by expected stimuli. Specifically, attention shifts to an unexpected stimulus are delayed relative to an expected stimulus (delayed onset account). Across two experiments, we investigated this claim under conditions of unguided (Exp. 1) and guided (Exp. 2) search using eye-movements as the primary index of attentional selection. In both experiments, we found strong evidence of surprise capture for the first presentation of an unannounced color singleton. However, in both experiments the pattern of eye-movements was not consistent with a delayed onset account of attention capture. Rather, we observed costs associated with the unexpected stimulus only once the target had been selected. We propose an interference account of surprise capture to explain our data and argue that this account also can explain existing patterns of data in the literature.

Global synchronization in finite time for fractional-order neural networks with discontinuous activations and time delays.

PubMed

Peng, Xiao; Wu, Huaiqin; Song, Ka; Shi, Jiaxin

2017-10-01

This paper is concerned with the global Mittag-Leffler synchronization and the synchronization in finite time for fractional-order neural networks (FNNs) with discontinuous activations and time delays. Firstly, the properties with respect to Mittag-Leffler convergence and convergence in finite time, which play a critical role in the investigation of the global synchronization of FNNs, are developed, respectively. Secondly, the novel state-feedback controller, which includes time delays and discontinuous factors, is designed to realize the synchronization goal. By applying the fractional differential inclusion theory, inequality analysis technique and the proposed convergence properties, the sufficient conditions to achieve the global Mittag-Leffler synchronization and the synchronization in finite time are addressed in terms of linear matrix inequalities (LMIs). In addition, the upper bound of the setting time of the global synchronization in finite time is explicitly evaluated. Finally, two examples are given to demonstrate the validity of the proposed design method and theoretical results. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stability and instability of a neuron network with excitatory and inhibitory small-world connections.

PubMed

Yu, Dongyuan; Xu, Xu; Zhou, Jing; Li, Eric

2017-05-01

This study considers a delayed neural network with excitatory and inhibitory shortcuts. The global stability of the trivial equilibrium is investigated based on Lyapunov's direct method and the delay-dependent criteria are obtained. It is shown that both the excitatory and inhibitory shortcuts decrease the stability interval, but a time delay can be employed as a global stabilizer. In addition, we analyze the bounds of the eigenvalues of the adjacent matrix using matrix perturbation theory and then obtain the generalized sufficient conditions for local stability. The possibility of small inhibitory shortcuts is helpful for maintaining stability. The mechanisms of instability, bifurcation modes, and chaos are also investigated. Compared with methods based on mean-field theory, the proposed method can guarantee the stability of the system in most cases with random events. The proposed method is effective for cases where excitatory and inhibitory shortcuts exist simultaneously in the network. Copyright © 2017 Elsevier Ltd. All rights reserved.

Robustness analysis of uncertain dynamical neural networks with multiple time delays.

PubMed

Senan, Sibel

2015-10-01

This paper studies the problem of global robust asymptotic stability of the equilibrium point for the class of dynamical neural networks with multiple time delays with respect to the class of slope-bounded activation functions and in the presence of the uncertainties of system parameters of the considered neural network model. By using an appropriate Lyapunov functional and exploiting the properties of the homeomorphism mapping theorem, we derive a new sufficient condition for the existence, uniqueness and global robust asymptotic stability of the equilibrium point for the class of neural networks with multiple time delays. The obtained stability condition basically relies on testing some relationships imposed on the interconnection matrices of the neural system, which can be easily verified by using some certain properties of matrices. An instructive numerical example is also given to illustrate the applicability of our result and show the advantages of this new condition over the previously reported corresponding results. Copyright © 2015 Elsevier Ltd. All rights reserved.

What Do Expectant Mothers Know about Neonatal Jaundice?

ERIC Educational Resources Information Center

Ogunfowora, Olusoga B.; Adefuye, Peter O.; Fetuga, Musili B.

2006-01-01

Neonatal jaundice (NNJ) is a common disorder worldwide and many affected babies become brain-damaged due to delay in seeking medical consultation. In order to assess the awareness and knowledge of expectant mothers about NNJ, women who registered for antenatal care at a tertiary health facility in the South-western part of Nigeria were…

Outcomes for Children Served through IDEA's Early Childhood Programs: 2014-15

ERIC Educational Resources Information Center

Early Childhood Technical Assistance Center, 2016

2016-01-01

In 2014-2015, children with delays or disabilities who received services under the Individuals with Disabilities Act (IDEA) showed greater than expected developmental progress. Many children exited the program functioning within age expectations, and most made progress. States' Part C and Part B Preschool programs report data annually on three…

Dynamics of solvation and desolvation of rubidium attached to He nanodroplets

NASA Astrophysics Data System (ADS)

von Vangerow, J.; John, O.; Stienkemeier, F.; Mudrich, M.

2015-07-01

The real-time dynamics of photoexcited and photoionized rubidium (Rb) atoms attached to helium (He) nanodroplets is studied by femtosecond pump-probe mass spectrometry. While excited Rb atoms in the perturbed 6p-state (Rb*) desorb off the He droplets, Rb+ photoions tend to sink into the droplet interior when created near the droplet surface. The transition from Rb+ solvation to full Rb* desorption is found to occur at a delay time τ ˜ 600 fs for Rb* in the 6pΣ-state and τ ˜ 1200 fs for the 6pΠ-state. Rb+He ions are found to be created by directly exciting bound Rb*He exciplex states as well as by populating bound Rb+He-states in a photoassociative ionization process.

Complex Nonlinear Dynamic System of Oligopolies Price Game with Heterogeneous Players Under Noise

NASA Astrophysics Data System (ADS)

Liu, Feng; Li, Yaguang

A nonlinear four oligopolies price game with heterogeneous players, that are boundedly rational and adaptive, is built using two different special demand costs. Based on the theory of complex discrete dynamical system, the stability and the existing equilibrium point are investigated. The complex dynamic behavior is presented via bifurcation diagrams, the Lyapunov exponents to show equilibrium state, bifurcation and chaos with the variation in parameters. As disturbance is ubiquitous in economic systems, this paper focuses on the analysis of delay feedback control method under noise circumstances. Stable dynamics is confirmed to depend mainly on the low price adjustment speed, and if all four players have limited opportunities to stabilize the market, the new adaptive player facing profits of scale are found to be higher than the incumbents of bounded rational.

Theoretical Prediction of Microgravity Ignition Delay of Polymeric Fuels in Low Velocity Flows

NASA Technical Reports Server (NTRS)

Fernandez-Pello, A. C.; Torero, J. L.; Zhou, Y. Y.; Walther, D.; Ross, H. D.

2001-01-01

A new flammability apparatus and protocol, FIST (Forced Flow Ignition and Flame Spread Test), is under development. Based on the LIFT (Lateral Ignition and Flame Spread Test) protocol, FIST better reflects the environments expected in spacebased facilities. The final objective of the FIST research is to provide NASA with a test methodology that complements the existing protocol and provides a more comprehensive assessment of material flammability of practical materials for space applications. Theoretical modeling, an extensive normal gravity data bank and a few validation space experiments will support the testing methodology. The objective of the work presented here is to predict the ignition delay and critical heat flux for ignition of solid fuels in microgravity at airflow velocities below those induced in normal gravity. This is achieved through the application of a numerical model previously developed of piloted ignition of solid polymeric materials exposed to an external radiant heat flux. The model predictions will provide quantitative results about ignition of practical materials in the limiting conditions expected in space facilities. Experimental data of surface temperature histories and ignition delay obtained in the KC-135 aircraft are used to determine the critical pyrolysate mass flux for ignition and this value is subsequently used to predict the ignition delay and the critical heat flux for ignition of the material. Surface temperature and piloted ignition delay calculations for Polymethylmethacrylate (PMMA) and a Polypropylene/Fiberglass (PP/GL) composite were conducted under both reduced and normal gravity conditions. It was found that ignition delay times are significantly shorter at velocities below those induced by natural convection.

Separate valuation subsystems for delay and effort decision costs.

PubMed

Prévost, Charlotte; Pessiglione, Mathias; Météreau, Elise; Cléry-Melin, Marie-Laure; Dreher, Jean-Claude

2010-10-20

Decision making consists of choosing among available options on the basis of a valuation of their potential costs and benefits. Most theoretical models of decision making in behavioral economics, psychology, and computer science propose that the desirability of outcomes expected from alternative options can be quantified by utility functions. These utility functions allow a decision maker to assign subjective values to each option under consideration by weighting the likely benefits and costs resulting from an action and to select the one with the highest subjective value. Here, we used model-based neuroimaging to test whether the human brain uses separate valuation systems for rewards (erotic stimuli) associated with different types of costs, namely, delay and effort. We show that humans devalue rewards associated with physical effort in a strikingly similar fashion to those they devalue that are associated with delays, and that a single computational model derived from economics theory can account for the behavior observed in both delay discounting and effort discounting. However, our neuroimaging data reveal that the human brain uses distinct valuation subsystems for different types of costs, reflecting in opposite fashion delayed reward and future energetic expenses. The ventral striatum and the ventromedial prefrontal cortex represent the increasing subjective value of delayed rewards, whereas a distinct network, composed of the anterior cingulate cortex and the anterior insula, represent the decreasing value of the effortful option, coding the expected expense of energy. Together, these data demonstrate that the valuation processes underlying different types of costs can be fractionated at the cerebral level.

HIV-1 Clinical Isolates Resistant to CCR5 Antagonists Exhibit Delayed Entry Kinetics That Are Corrected in the Presence of Drug

PubMed Central

Putcharoen, Opass; Lee, Sun Hee; Henrich, Timothy J.; Hu, Zixin; Vanichanan, Jakapat; Coakley, Eoin; Greaves, Wayne; Gulick, Roy M.; Kuritzkes, Daniel R.

2012-01-01

HIV CCR5 antagonists select for env gene mutations that enable virus entry via drug-bound coreceptor. To investigate the mechanisms responsible for viral adaptation to drug-bound coreceptor-mediated entry, we studied viral isolates from three participants who developed CCR5 antagonist resistance during treatment with vicriviroc (VCV), an investigational small-molecule CCR5 antagonist. VCV-sensitive and -resistant viruses were isolated from one HIV subtype C- and two subtype B-infected participants; VCV-resistant isolates had mutations in the V3 loop of gp120 and were cross-resistant to TAK-779, an investigational antagonist, and maraviroc (MVC). All three resistant isolates contained a 306P mutation but had variable mutations elsewhere in the V3 stem. We used a virus-cell β-lactamase (BlaM) fusion assay to determine the entry kinetics of recombinant viruses that incorporated full-length VCV-sensitive and -resistant envelopes. VCV-resistant isolates exhibited delayed entry rates in the absence of drug, relative to pretherapy VCV-sensitive isolates. The addition of drug corrected these delays. These findings were generalizable across target cell types with a range of CD4 and CCR5 surface densities and were observed when either population-derived or clonal envelopes were used to construct recombinant viruses. V3 loop mutations alone were sufficient to restore virus entry in the presence of drug, and the accumulation of V3 mutations during VCV therapy led to progressively higher rates of viral entry. We propose that the restoration of pre-CCR5 antagonist therapy HIV entry kinetics drives the selection of V3 loop mutations and may represent a common mechanism that underlies the emergence of CCR5 antagonist resistance. PMID:22090117

49 CFR 375.605 - How must I notify an individual shipper of any service delays?

Code of Federal Regulations, 2011 CFR

2011-10-01

... during the periods specified in the order for service and as soon as the delay becomes apparent to you... you expect to be able to pick up and/or deliver the shipment. You must consider the needs of the... your amended date or period for pick-up or delivery. (3) You must retain these records as a part of...

49 CFR 375.605 - How must I notify an individual shipper of any service delays?

Code of Federal Regulations, 2010 CFR

2010-10-01

... during the periods specified in the order for service and as soon as the delay becomes apparent to you... you expect to be able to pick up and/or deliver the shipment. You must consider the needs of the... your amended date or period for pick-up or delivery. (3) You must retain these records as a part of...

Doubly tagged delayed-choice tunable quantum eraser: coherence, information and measurement

NASA Astrophysics Data System (ADS)

Imran, Muhammad; Tariq, Hinna; Rameez-ul-Islam; Ikram, Manzoor

2018-01-01

We present an idea for the doubly tagged delayed-choice tunable quantum eraser in a cavity QED setup, based on fully controlled resonant as well as dispersive atom-field interactions. Two cavity fields, bound initially in the Bell state, are coupled to a three-level atom. Such an atom is initially prepared in the coherent superposition of the lower two levels and is quite capable of exhibiting Ramsey fringes if taken independently. It is shown that the coherence lost due to tagging can not only be retrieved but that the fringe visibility/path distinguishability can also be conditionally tuned in a delayed manner through local manipulation of the entangled cavity fields. The stringent condition here is the retainment of the system’s coherence during successive manipulations of the individual cavity fields. Such a quantum eraser, therefore, prominently highlights the links among all the counterintuitive features of quantum theory including the conception of time, measurement, state vector reduction, coherence and information in an unambiguous manner. The schematics can be straightforwardly extended to a multipartite scenario and employed to explore multi-player quantum games with the payoff being strangely decided through delayed choice setups.

A Deadline-Aware Scheduling and Forwarding Scheme in Wireless Sensor Networks.

PubMed

Dao, Thi-Nga; Yoon, Seokhoon; Kim, Jangyoung

2016-01-05

Many applications in wireless sensor networks (WSNs) require energy consumption to be minimized and the data delivered to the sink within a specific delay. A usual solution for reducing energy consumption is duty cycling, in which nodes periodically switch between sleep and active states. By increasing the duty cycle interval, consumed energy can be reduced more. However, a large duty cycle interval causes a long end-to-end (E2E) packet delay. As a result, the requirement of a specific delay bound for packet delivery may not be satisfied. In this paper, we aim at maximizing the duty cycle while still guaranteeing that the packets arrive at the sink with the required probability, i.e., the required delay-constrained success ratio (DCSR) is achieved. In order to meet this objective, we propose a novel scheduling and forwarding scheme, namely the deadline-aware scheduling and forwarding (DASF) algorithm. In DASF, the E2E delay distribution with the given network model and parameters is estimated in order to determine the maximum duty cycle interval, with which the required DCSR is satisfied. Each node independently selects a wake-up time using the selected interval, and packets are forwarded to a node in the potential forwarding set, which is determined based on the distance between nodes and the sink. DASF does not require time synchronization between nodes, and a node does not need to maintain neighboring node information in advance. Simulation results show that the proposed scheme can satisfy a required delay-constrained success ratio and outperforms existing algorithms in terms of E2E delay and DCSR.

A Deadline-Aware Scheduling and Forwarding Scheme in Wireless Sensor Networks

PubMed Central

Dao, Thi-Nga; Yoon, Seokhoon; Kim, Jangyoung

2016-01-01

Many applications in wireless sensor networks (WSNs) require energy consumption to be minimized and the data delivered to the sink within a specific delay. A usual solution for reducing energy consumption is duty cycling, in which nodes periodically switch between sleep and active states. By increasing the duty cycle interval, consumed energy can be reduced more. However, a large duty cycle interval causes a long end-to-end (E2E) packet delay. As a result, the requirement of a specific delay bound for packet delivery may not be satisfied. In this paper, we aim at maximizing the duty cycle while still guaranteeing that the packets arrive at the sink with the required probability, i.e., the required delay-constrained success ratio (DCSR) is achieved. In order to meet this objective, we propose a novel scheduling and forwarding scheme, namely the deadline-aware scheduling and forwarding (DASF) algorithm. In DASF, the E2E delay distribution with the given network model and parameters is estimated in order to determine the maximum duty cycle interval, with which the required DCSR is satisfied. Each node independently selects a wake-up time using the selected interval, and packets are forwarded to a node in the potential forwarding set, which is determined based on the distance between nodes and the sink. DASF does not require time synchronization between nodes, and a node does not need to maintain neighboring node information in advance. Simulation results show that the proposed scheme can satisfy a required delay-constrained success ratio and outperforms existing algorithms in terms of E2E delay and DCSR. PMID:26742046

Fundamental performance of transverse wind estimator from Shack-Hartmann wave-front sensor measurements.

PubMed

Li, Zhenghan; Li, Xinyang

2018-04-30

Real time transverse wind estimation contributes to predictive correction which is used to compensate for the time delay error in the control systems of adaptive optics (AO) system. Many methods that apply Shack-Hartmann wave-front sensor to wind profile measurement have been proposed. One of the obvious problems is the lack of a fundamental benchmark to compare the various methods. In this work, we present the fundamental performance limits for transverse wind estimator from Shack-Hartmann wave-front sensor measurements using Cramér-Rao lower bound (CRLB). The bound provides insight into the nature of the transverse wind estimation, thereby suggesting how to design and improve the estimator in the different application scenario. We analyze the theoretical bound and find that factors such as slope measurement noise, wind velocity and atmospheric coherence length r 0 have important influence on the performance. Then, we introduced the non-iterative gradient-based transverse wind estimator. The source of the deterministic bias of the gradient-based transverse wind estimators is analyzed for the first time. Finally, we derived biased CRLB for the gradient-based transverse wind estimators from Shack-Hartmann wave-front sensor measurements and the bound can predict the performance of estimator more accurately.

The effect of response-delay on estimating reachability.

PubMed

Gabbard, Carl; Ammar, Diala

2008-11-01

The experiment was conducted to compare visual imagery (VI) and motor imagery (MI) reaching tasks in a response-delay paradigm designed to explore the hypothesized dissociation between vision for perception and vision for action. Although the visual systems work cooperatively in motor control, theory suggests that they operate under different temporal constraints. From this perspective, we expected that delay would affect MI but not VI because MI operates in real time and VI is postulated to be memory-driven. Following measurement of actual reach, right-handers were presented seven (imagery) targets at midline in eight conditions: MI and VI with 0-, 1-, 2-, and 4-s delays. Results indicted that delay affected the ability to estimate reachability with MI but not with VI. These results are supportive of a general distinction between vision for perception and vision for action.

Decentralized control

NASA Technical Reports Server (NTRS)

Steffen, Chris

1990-01-01

An overview of the time-delay problem and the reliability problem which arise in trying to perform robotic construction operations at a remote space location are presented. The effects of the time-delay upon the control system design will be itemized. A high level overview of a decentralized method of control which is expected to perform better than the centralized approach in solving the time-delay problem is given. The lower level, decentralized, autonomous, Troter Move-Bar algorithm is also presented (Troters are coordinated independent robots). The solution of the reliability problem is connected to adding redundancy to the system. One method of adding redundancy is given.

Acoustic trapping in bubble-bounded micro-cavities

NASA Astrophysics Data System (ADS)

O'Mahoney, P.; McDougall, C.; Glynne-Jones, P.; MacDonald, M. P.

2016-12-01

We present a method for controllably producing longitudinal acoustic trapping sites inside microfluidic channels. Air bubbles are injected into a micro-capillary to create bubble-bounded `micro-cavities'. A cavity mode is formed that shows controlled longitudinal acoustic trapping between the two air/water interfaces along with the levitation to the centre of the channel that one would expect from a lower order lateral mode. 7 μm and 10 μm microspheres are trapped at the discrete acoustic trapping sites in these micro-cavities.We show this for several lengths of micro-cavity.

The effects of cholelithiasis and cholecystectomy on gastric emptying.

PubMed

Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y

In this clinical study, four groups, each consisting of 12 patients are established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy. 1. group: healthy people, 2. group: patients with dyspeptic cholelithiasis, 3. group: patients who have no dyspepsia after cholecystectomy, 4. group: patients whose dyspepsia is continued after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulfur colloid bound with scrambled eggs. Gastric emptying delayed in second (p < 0.001) and fourth (p < 0.005) groups postprandially and not differed in the third group (p > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy have a close relation with delay in gastric emptying.

Effects of cholelithiasis and cholecystectomy on gastric emptying.

PubMed

Köksoy, F N; Bulut, T; Köse, H; Soybir, G; Yalçin, O; Aker, Y

1994-06-01

In this prospective, clinical study, four groups, each consisting of 12 patients were established to determine how gastric emptying is influenced in cholelithiasis with accompanied flatulent dyspepsia and the relationship of symptoms and gastric emptying after cholecystectomy: group 1--healthy people; group 2--patients with dyspeptic cholelithiasis; group 3--patients with no dyspepsia after cholecystectomy; group 4--patients with dyspepsia after cholecystectomy. Groups are compared according to solid phase gastric emptying scintigraphies performed with Tc 99m sulphur colloid bound with scrambled eggs. Gastric emptying delayed in groups 2 (P < 0.001) and 4 (P < 0.005) postprandially and did not differ in the group 3 (P > 0.005). These results demonstrate that dyspepsia, in cholelithiasis and persisting after cholecystectomy, has a close relation with delay in gastric emptying.

Finite-time synchronization for memristor-based neural networks with time-varying delays.

PubMed

Abdurahman, Abdujelil; Jiang, Haijun; Teng, Zhidong

2015-09-01

Memristive network exhibits state-dependent switching behaviors due to the physical properties of memristor, which is an ideal tool to mimic the functionalities of the human brain. In this paper, finite-time synchronization is considered for a class of memristor-based neural networks with time-varying delays. Based on the theory of differential equations with discontinuous right-hand side, several new sufficient conditions ensuring the finite-time synchronization of memristor-based chaotic neural networks are obtained by using analysis technique, finite time stability theorem and adding a suitable feedback controller. Besides, the upper bounds of the settling time of synchronization are estimated. Finally, a numerical example is given to show the effectiveness and feasibility of the obtained results. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamic Routing for Delay-Tolerant Networking in Space Flight Operations

NASA Technical Reports Server (NTRS)

Burleigh, Scott C.

2008-01-01

Contact Graph Routing (CGR) is a dynamic routing system that computes routes through a time-varying topology composed of scheduled, bounded communication contacts in a network built on the Delay-Tolerant Networking (DTN) architecture. It is designed to support operations in a space network based on DTN, but it also could be used in terrestrial applications where operation according to a predefined schedule is preferable to opportunistic communication, as in a low-power sensor network. This paper will describe the operation of the CGR system and explain how it can enable data delivery over scheduled transmission opportunities, fully utilizing the available transmission capacity, without knowing the current state of any bundle protocol node (other than the local node itself) and without exhausting processing resources at any bundle router.

Adaptive neural control for a class of nonlinear time-varying delay systems with unknown hysteresis.

PubMed

Liu, Zhi; Lai, Guanyu; Zhang, Yun; Chen, Xin; Chen, Chun Lung Philip

2014-12-01

This paper investigates the fusion of unknown direction hysteresis model with adaptive neural control techniques in face of time-delayed continuous time nonlinear systems without strict-feedback form. Compared with previous works on the hysteresis phenomenon, the direction of the modified Bouc-Wen hysteresis model investigated in the literature is unknown. To reduce the computation burden in adaptation mechanism, an optimized adaptation method is successfully applied to the control design. Based on the Lyapunov-Krasovskii method, two neural-network-based adaptive control algorithms are constructed to guarantee that all the system states and adaptive parameters remain bounded, and the tracking error converges to an adjustable neighborhood of the origin. In final, some numerical examples are provided to validate the effectiveness of the proposed control methods.

Robust stochastic stability of discrete-time fuzzy Markovian jump neural networks.

PubMed

Arunkumar, A; Sakthivel, R; Mathiyalagan, K; Park, Ju H

2014-07-01

This paper focuses the issue of robust stochastic stability for a class of uncertain fuzzy Markovian jumping discrete-time neural networks (FMJDNNs) with various activation functions and mixed time delay. By employing the Lyapunov technique and linear matrix inequality (LMI) approach, a new set of delay-dependent sufficient conditions are established for the robust stochastic stability of uncertain FMJDNNs. More precisely, the parameter uncertainties are assumed to be time varying, unknown and norm bounded. The obtained stability conditions are established in terms of LMIs, which can be easily checked by using the efficient MATLAB-LMI toolbox. Finally, numerical examples with simulation result are provided to illustrate the effectiveness and less conservativeness of the obtained results. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

PWFQ: a priority-based weighted fair queueing algorithm for the downstream transmission of EPON

NASA Astrophysics Data System (ADS)

Xu, Sunjuan; Ye, Jiajun; Zou, Junni

2005-11-01

In the downstream direction of EPON, all ethernet frames share one downlink channel from the OLT to destination ONUs. To guarantee differentiated services, a scheduling algorithm is needed to solve the link-sharing issue. In this paper, we first review the classical WFQ algorithm and point out the shortcomings existing in the fair queueing principle of WFQ algorithm for EPON. Then we propose a novel scheduling algorithm called Priority-based WFQ (PWFQ) algorithm which distributes bandwidth based on priority. PWFQ algorithm can guarantee the quality of real-time services whether under light load or under heavy load. Simulation results also show that PWFQ algorithm not only can improve delay performance of real-time services, but can also meet the worst-case delay bound requirements.

A Simple Network Architecture Accounts for Diverse Reward Time Responses in Primary Visual Cortex

PubMed Central

Hussain Shuler, Marshall G.; Shouval, Harel Z.

2015-01-01

Many actions performed by animals and humans depend on an ability to learn, estimate, and produce temporal intervals of behavioral relevance. Exemplifying such learning of cued expectancies is the observation of reward-timing activity in the primary visual cortex (V1) of rodents, wherein neural responses to visual cues come to predict the time of future reward as behaviorally experienced in the past. These reward-timing responses exhibit significant heterogeneity in at least three qualitatively distinct classes: sustained increase or sustained decrease in firing rate until the time of expected reward, and a class of cells that reach a peak in firing at the expected delay. We elaborate upon our existing model by including inhibitory and excitatory units while imposing simple connectivity rules to demonstrate what role these inhibitory elements and the simple architectures play in sculpting the response dynamics of the network. We find that simply adding inhibition is not sufficient for obtaining the different distinct response classes, and that a broad distribution of inhibitory projections is necessary for obtaining peak-type responses. Furthermore, although changes in connection strength that modulate the effects of inhibition onto excitatory units have a strong impact on the firing rate profile of these peaked responses, the network exhibits robustness in its overall ability to predict the expected time of reward. Finally, we demonstrate how the magnitude of expected reward can be encoded at the expected delay in the network and how peaked responses express this reward expectancy. SIGNIFICANCE STATEMENT Heterogeneity in single-neuron responses is a common feature of neuronal systems, although sometimes, in theoretical approaches, it is treated as a nuisance and seldom considered as conveying a different aspect of a signal. In this study, we focus on the heterogeneous responses in the primary visual cortex of rodents trained with a predictable delayed reward time. We describe under what conditions this heterogeneity can arise by self-organization, and what information it can convey. This study, while focusing on a specific system, provides insight onto how heterogeneity can arise in general while also shedding light onto mechanisms of reinforcement learning using realistic biological assumptions. PMID:26377457

A Discounting Framework for Choice With Delayed and Probabilistic Rewards

PubMed Central

Green, Leonard; Myerson, Joel

2005-01-01

When choosing between delayed or uncertain outcomes, individuals discount the value of such outcomes on the basis of the expected time to or the likelihood of their occurrence. In an integrative review of the expanding experimental literature on discounting, the authors show that although the same form of hyperbola-like function describes discounting of both delayed and probabilistic outcomes, a variety of recent findings are inconsistent with a single-process account. The authors also review studies that compare discounting in different populations and discuss the theoretical and practical implications of the findings. The present effort illustrates the value of studying choice involving both delayed and probabilistic outcomes within a general discounting framework that uses similar experimental procedures and a common analytical approach. PMID:15367080

Robust H∞ cost guaranteed integral sliding mode control for the synchronization problem of nonlinear tele-operation system with variable time-delay.

PubMed

Al-Wais, Saba; Khoo, Suiyang; Lee, Tae Hee; Shanmugam, Lakshmanan; Nahavandi, Saeid

2018-01-01

This paper is devoted to the synchronization problem of tele-operation systems with time-varying delay, disturbances, and uncertainty. Delay-dependent sufficient conditions for the existence of integral sliding surfaces are given in the form of Linear Matrix Inequalities (LMIs). This guarantees the global stability of the tele-operation system with known upper bounds of the time-varying delays. Unlike previous work, in this paper, the controller gains are designed but not chosen, which increases the degree of freedom of the design. Moreover, Wirtinger based integral inequality and reciprocally convex combination techniques used in the constructed Lypunove-Krasoviskii Functional (LKF) are deemed to give less conservative stability condition for the system. Furthermore, to relax the analysis from any assumptions regarding the dynamics of the environment and human operator forces, H ∞ design method is used to involve the dynamics of these forces and ensure the stability of the system against these admissible forces in the H ∞ sense. This design scheme combines the strong robustness of the sliding mode control with the H ∞ design method for tele-operation systems which is coupled using state feedback controllers and inherit variable time-delays in their communication channels. Simulation examples are given to show the effectiveness of the proposed method. Copyright © 2017 ISA. All rights reserved.

Dual conception of risk in the Iowa Gambling Task: effects of sleep deprivation and test-retest gap.

PubMed

Singh, Varsha

2013-01-01

Risk in the Iowa Gambling Task (IGT) is often understood in terms of intertemporal choices, i.e., preference for immediate outcomes in favor of delayed outcomes is considered risky decision making. According to behavioral economics, healthy decision makers are expected to refrain from choosing the short-sighted immediate gain because, over time (10 trials of the IGT), the immediate gains result in a long term loss (net loss). Instead decision makers are expected to maximize their gains by choosing options that, over time (10 trials), result in delayed or long term gains (net gain). However, task choices are sometimes made on the basis of the frequency of reward and punishment such that frequent rewards/infrequent punishments are favored over infrequent rewards/frequent punishments. The presence of these two attributes (intertemporality and frequency of reward) in IGT decision making may correspond to the emotion-cognition dichotomy and reflect a dual conception of risk. Decision making on the basis of the two attributes was tested under two conditions: delay in retest and sleep deprivation. An interaction between sleep deprivation and time delay was expected to attenuate the difference between the two attributes. Participants were 40 male university students. Analysis of the effects of IGT attribute type (intertemporal vs. frequency of reinforcement), sleep deprivation (sleep deprivation vs. no sleep deprivation), and test-retest gap (short vs. long delay) showed a significant within-subjects effect of IGT attribute type thus confirming the difference between the two attributes. Sleep deprivation had no effect on the attributes, but test-retest gap and the three-way interaction between attribute type, test-retest gap, and sleep deprivation were significantly different. Post-hoc tests revealed that sleep deprivation and short test-retest gap attenuated the difference between the two attributes. Furthermore, the results showed an expected trend of increase in intertemporal decision making at retest suggesting that intertemporal decision making benefited from repeated task exposure. The present findings add to understanding of the emotion-cognition dichotomy. Further, they show an important time-dependent effect of a universally experienced constraint (sleep deprivation) on decision making. It is concluded that risky decision making in the IGT is contingent on the attribute under consideration and is affected by factors such as time elapsed and constraint experienced before the retest.

Expected Reachability-Time Games

NASA Astrophysics Data System (ADS)

Forejt, Vojtěch; Kwiatkowska, Marta; Norman, Gethin; Trivedi, Ashutosh

In an expected reachability-time game (ERTG) two players, Min and Max, move a token along the transitions of a probabilistic timed automaton, so as to minimise and maximise, respectively, the expected time to reach a target. These games are concurrent since at each step of the game both players choose a timed move (a time delay and action under their control), and the transition of the game is determined by the timed move of the player who proposes the shorter delay. A game is turn-based if at any step of the game, all available actions are under the control of precisely one player. We show that while concurrent ERTGs are not always determined, turn-based ERTGs are positionally determined. Using the boundary region graph abstraction, and a generalisation of Asarin and Maler's simple function, we show that the decision problems related to computing the upper/lower values of concurrent ERTGs, and computing the value of turn-based ERTGs are decidable and their complexity is in NEXPTIME ∩ co-NEXPTIME.

Generalized surface tension bounds in vacuum decay

NASA Astrophysics Data System (ADS)

Masoumi, Ali; Paban, Sonia; Weinberg, Erick J.

2018-02-01

Coleman and De Luccia (CDL) showed that gravitational effects can prevent the decay by bubble nucleation of a Minkowski or AdS false vacuum. In their thin-wall approximation this happens whenever the surface tension in the bubble wall exceeds an upper bound proportional to the difference of the square roots of the true and false vacuum energy densities. Recently it was shown that there is another type of thin-wall regime that differs from that of CDL in that the radius of curvature grows substantially as one moves through the wall. Not only does the CDL derivation of the bound fail in this case, but also its very formulation becomes ambiguous because the surface tension is not well defined. We propose a definition of the surface tension and show that it obeys a bound similar in form to that of the CDL case. We then show that both thin-wall bounds are special cases of a more general bound that is satisfied for all bounce solutions with Minkowski or AdS false vacua. We discuss the limit where the parameters of the theory attain critical values and the bound is saturated. The bounce solution then disappears and a static planar domain wall solution appears in its stead. The scalar field potential then is of the form expected in supergravity, but this is only guaranteed along the trajectory in field space traced out by the bounce.

Early hospital discharge of infants born to group B streptococci-positive mothers: a decision analysis.

PubMed

Berger, M B; Xu, X; Williams, J A; Van de Ven, C J M; Mozurkewich, E L

2012-03-01

To compare the cost-effectiveness of an additional 24-hour inpatient observation for asymptomatic term neonates born to group B streptococcus (GBS)-colonised mothers with adequate intrapartum antibiotic prophylaxis (IAP) after an initial 24-hour in-hospital observation. Cost-effectiveness analysis from a societal perspective. United States. Asymptomatic term neonates born to GBS-colonised mothers with IAP after an initial 24-hour in-hospital observation. Monte Carlo simulation for a decision tree model incorporating the following chance events: development of GBS sepsis during the second 24 hours of life, development of GBS sepsis between 48 hours and 7 days of life, prompt versus delayed treatment for sepsis, neonatal mortality and long-term health sequelae. Expected cost and quality-adjusted life years (QALYs), Incremental cost-effectiveness ratio (ICER). Delayed, versus early, hospital discharge results in similar mean expected QALYs, but substantially higher expected cost. The mean difference in QALY is 0.00016 (95% CI 0.00005-0.00040), whereas the mean difference in cost is $1170.96 (95% CI $750.13-1584.32). The ICER is estimated to be $9,771,520.87 per QALY (95% CI $2,573,139.89-24,407,017.82). The proportion of early-onset GBS that develops during the second 24 hours of life, the cost of 24 hours of inpatient observation, and the probability of long-term sequelae following prompt versus delayed treatment play important roles in determining the cost-effectiveness of delayed hospital discharge. Cost-effectiveness analysis suggests that with adequate IAP, discharging asymptomatic term neonates to home after 24 hours is the preferred approach compared with 48 hours inpatient observation. © 2012 The Authors BJOG An International Journal of Obstetrics and Gynaecology © 2012 RCOG.

Prehospital delay, contributing aspects and responses to symptoms among Norwegian women and men with first time acute myocardial infarction.

PubMed

Løvlien, M; Schei, B; Hole, T

2007-12-01

In patients with acute myocardial infarction (AMI), the delay between the onset of symptoms and hospital admission is a critical factor in reducing morbidity and mortality. To assess gender differences in prehospital delay among women and men with first time AMI, generate more knowledge about aspects influencing this delay and investigate responses to acute symptoms. Of 738 eligible patients, 149 women and 384 men responded to a questionnaire (72%). Over half of both women and men waited over one hour before they called for medical assistance and more than half the patients had a total prehospital delay exceeding two hours. Rapid development of symptoms and symptoms matching expectations reduced, self medication and consulting the spouse increased patient delay in both genders. Calling the Emergency Medical Service (EMS) reduced and calling a general practitioner increased total prehospital delay in both genders. ST-ELEVATION: (STEMI), symptoms experienced as unbearable and attributed as cardiac reduced patient delay, and symptoms from the back, shoulders or between scapulae increased prehospital delay, only in men. How patients responded to symptoms had vital impact on prehospital delay among both genders, but the experience and interpretation of symptoms had more influence in men than in women.

Constraining the right-handed gauge boson mass from lepton number violating meson decays in a low scale left-right model

NASA Astrophysics Data System (ADS)

Mandal, Sanjoy; Mitra, Manimala; Sinha, Nita

2017-08-01

We analyze the lepton number violating (LNV) meson decays that arise in a TeV scale left-right symmetry model. The right-handed Majorana neutrino N along with the right-handed or Standard Model gauge bosons mediate the meson decays and provide a resonant enhancement of the rates if the mass of N (MN) lies in the range ˜(100 MeV - 5 GeV ) . Using the expected upper limits on the number of events for the LNV decay modes M1+→ℓ+ℓ+ π- (M1=B,D,Ds, K ), we derive constraints plausible on the mass of the right handed charged gauge boson by future searches at the ongoing NA62 and LHCb experiments at CERN, the upcoming Belle II at SuperKEK, as well as at the proposed future experiments, SHiP and FCC-ee. These bounds are complimentary to the limits from the same-sign dilepton search at the Large Hadron Collider (LHC). The very high intensity of charmed mesons expected to be produced at SHiP will result in a far more stringent bound, MW R>18.4 TeV (corresponding to MN=1.46 GeV ), than the other existing bounds from collider and neutrinoless double beta decay searches.

Left Behind: A Bound Remnant from a White Dwarf Supernova?

NASA Astrophysics Data System (ADS)

Jha, Saurabh

2017-08-01

Type Ia supernovae (SN Ia) have enormous importance to cosmology and astrophysics, but their progenitors and explosion mechanisms are not understood in detail. Recently, observations and theoretical models have suggested that not all thermonuclear white-dwarf supernova explosions are normal SN Ia. In particular, type Iax supernovae (peculiar cousins to SN Ia), are thought to be exploding white dwarfs that are not completely disrupted, leaving behind a bound remnant. In deep and serendipitous HST pre-explosion data, we have discovered a luminous, blue progenitor system for the type Iax SN 2012Z in NGC 1309, which we interpret as a helium-star donor to the exploding white dwarf. HST observations of SN 2012Z in 2016, when the supernova light was expected to have faded away, still show a source at the location, as expected in our model where the pre-explosion flux was coming from the companion. However, the 2016 data also show a surprise: an excess flux compared to the progenitor system. Our proposed observations here will help unravel the mystery of that excess flux: is it from the bound ex-white dwarf remnant? Or is it from the shocked companion star that has been bombarded by supernova ejecta? Either of these possibilities would provide key new evidence as to the nature of these white dwarf supernovae.

Causes of shortage and delay in material supply: a preliminary study

NASA Astrophysics Data System (ADS)

Rahman, M. M.; Yap, Y. H.; Ramli, N. R.; Dullah, M. A.; Shamsuddin, M. S. W.

2017-11-01

Shortage and delay in materials supply is argued to be one of the most important factors that lead to delay in construction project delivery globally. However, the relevant underlying reasons vary from country to country. As such, this paper summarises the outcomes of a study that targeted identifying causes of shortage and delay in materials supply in Brunei Darussalam. The study was conducted through fifteen semi-structured interviews of contractors and materials suppliers in Brunei. The study identified six causes of shortageof materials and nine causes of delay in materials supply in Brunei. The most importantcausefor shortage of materials relates to the origin or availability of construction materials. On the other hand, the most influential cause of delay in material supply was found to be poor materials procurement and inventory management system, which has other underlying reasons such as late identification of the type of materials needed. The observations are expected to help in formulating or reviewing relevant policies, in order to ensure on-time project delivery.

Effects of general and alcohol-specific media literacy training on children's decision making about alcohol.

PubMed

Austin, E W; Johnson, K K

1997-01-01

This article examines the immediate and delayed effects of media literacy training on third-grade children's perceptions of alcohol advertising, alcohol norms, expectancies for drinking, and behaviors toward alcohol. A Solomon four-group style experiment (N = 225) with two levels of the treatment factor assessed the effectiveness of in-school media literacy training for alcohol. The experiment compared a treatment that included the viewing of a videotape about television advertising along with the viewing of video clips of alcohol ads and discussion pertaining to alcohol advertising specifically versus one that included the viewing of the same general purpose media literacy videotape along with video clips of non-alcohol advertising and then discussion of advertising in general. The treatment had both immediate and delayed effects. Immediate effects included the children's increased understanding of persuasive intent, viewing of characters as less similar to people they knew in real life and less desirable, decreased desire to be like the characters, decreased expectation of positive consequences from drinking alcohol, and decreased likelihood to choose an alcohol-related product. Indirect effects also were found on their perceptions of television's realism and their views of social norms related to alcohol. Delayed effects were examined and confirmed on expectancies and behavior. The treatment was more effective when alcohol-specific, and it also was more effective among girls than boys.

Quantized Synchronization of Chaotic Neural Networks With Scheduled Output Feedback Control.

PubMed

Wan, Ying; Cao, Jinde; Wen, Guanghui

In this paper, the synchronization problem of master-slave chaotic neural networks with remote sensors, quantization process, and communication time delays is investigated. The information communication channel between the master chaotic neural network and slave chaotic neural network consists of several remote sensors, with each sensor able to access only partial knowledge of output information of the master neural network. At each sampling instants, each sensor updates its own measurement and only one sensor is scheduled to transmit its latest information to the controller's side in order to update the control inputs for the slave neural network. Thus, such communication process and control strategy are much more energy-saving comparing with the traditional point-to-point scheme. Sufficient conditions for output feedback control gain matrix, allowable length of sampling intervals, and upper bound of network-induced delays are derived to ensure the quantized synchronization of master-slave chaotic neural networks. Lastly, Chua's circuit system and 4-D Hopfield neural network are simulated to validate the effectiveness of the main results.In this paper, the synchronization problem of master-slave chaotic neural networks with remote sensors, quantization process, and communication time delays is investigated. The information communication channel between the master chaotic neural network and slave chaotic neural network consists of several remote sensors, with each sensor able to access only partial knowledge of output information of the master neural network. At each sampling instants, each sensor updates its own measurement and only one sensor is scheduled to transmit its latest information to the controller's side in order to update the control inputs for the slave neural network. Thus, such communication process and control strategy are much more energy-saving comparing with the traditional point-to-point scheme. Sufficient conditions for output feedback control gain matrix, allowable length of sampling intervals, and upper bound of network-induced delays are derived to ensure the quantized synchronization of master-slave chaotic neural networks. Lastly, Chua's circuit system and 4-D Hopfield neural network are simulated to validate the effectiveness of the main results.

Learning monopolies with delayed feedback on price expectations

NASA Astrophysics Data System (ADS)

Matsumoto, Akio; Szidarovszky, Ferenc

2015-11-01

We call the intercept of the price function with the vertical axis the maximum price and the slope of the price function the marginal price. In this paper it is assumed that a monopolistic firm has full information about the marginal price and its own cost function but is uncertain on the maximum price. However, by repeated interaction with the market, the obtained price observations give a basis for an adaptive learning process of the maximum price. It is also assumed that the price observations have fixed delays, so the learning process can be described by a delayed differential equation. In the cases of one or two delays, the asymptotic behavior of the resulting dynamic process is examined, stability conditions are derived. Three main results are demonstrated in the two delay learning processes. First, it is possible to stabilize the equilibrium which is unstable in the one delay model. Second, complex dynamics involving chaos, which is impossible in the one delay model, can emerge. Third, alternations of stability and instability (i.e., stability switches) occur repeatedly.

Dealing with delays does not transfer across sensorimotor tasks.

PubMed

de la Malla, Cristina; López-Moliner, Joan; Brenner, Eli

2014-10-09

It is known that people can learn to deal with delays between their actions and the consequences of such actions. We wondered whether they do so by adjusting their anticipations about the sensory consequences of their actions or whether they simply learn to move in certain ways when performing specific tasks. To find out, we examined details of how people learn to intercept a moving target with a cursor that follows the hand with a delay and examined the transfer of learning between this task and various other tasks that require temporal precision. Subjects readily learned to intercept the moving target with the delayed cursor. The compensation for the delay generalized across modifications of the task, so subjects did not simply learn to move in a certain way in specific circumstances. The compensation did not generalize to completely different timing tasks, so subjects did not generally expect the consequences of their motor commands to be delayed. We conclude that people specifically learn to control the delayed visual consequences of their actions to perform certain tasks. © 2014 ARVO.

Deference in Indians' decision making: introjected goals or injunctive norms?

PubMed

Savani, Krishna; Morris, Michael W; Naidu, N V R

2012-04-01

We examine the claim that Indians are more likely than Americans to act deferentially in the presence of authority figures and explore 2 possible psychological mechanisms for this cultural difference: introjected goals and injunctive norms. Studies 1 and 2 showed that after reflecting upon an authority's expectations, Indians were more likely than Americans to make clothing and course choices consistent with the authority's expectations, but there was no such cultural difference for peers' expectations. Study 3 showed that merely activating the concept of authority figures, without highlighting specific expectations, was sufficient to influence Indians' choices but not their evaluations. Examining a more basic distinction underlying introjected goals versus injunctive norms, Study 4 showed that authority primes influenced Indians' sense of what they should do but not what they want to do. Study 5 showed that, inconsistent with the internalized goal mechanism, the effect of explicit authority primes did not increase after brief delays. However, Indian participants who were less likely to accommodate to the salient authority experienced more guilt across delay conditions, which supported the injunctive norms mechanism. The findings suggest that manipulating injunctive norms can be an effective means for inducing or eliminating deferential behaviors in Indian settings. (c) 2012 APA, all rights reserved.

Network Policy Management

DTIC Science & Technology

1999-09-01

In truth , there may be some overlap between the various events. This could reduce the total amount of time that the function was not available to...in int-serv provides hard bounds on the maximum delay that will be experienced by the packets. It does so by explicitly reserving resources along the ...network is a soft target. This was noted by Bellovin who coined the term " Hard on the outside, soft and chewy on the inside" [Ref. 26] to describe

Effects of a Conversation-Based Intervention on the Linguistic Skills of Children With Motor Speech Disorders Who Use Augmentative and Alternative Communication.

PubMed

Soto, Gloria; Clarke, Michael T

2017-07-12

This study was conducted to evaluate the effects of a conversation-based intervention on the expressive vocabulary and grammatical skills of children with severe motor speech disorders and expressive language delay who use augmentative and alternative communication. Eight children aged from 8 to 13 years participated in the study. After a baseline period, a conversation-based intervention was provided for each participant, in which they were supported to learn and use linguistic structures essential for the formation of clauses and the grammaticalization of their utterances, such as pronouns, verbs, and bound morphemes, in the context of personally meaningful and scaffolded conversations with trained clinicians. The conversations were videotaped, transcribed, and analyzed using the Systematic Analysis of Language Transcripts (SALT; Miller & Chapman, 1991). Results indicate that participants showed improvements in their use of spontaneous clauses, and a greater use of pronouns, verbs, and bound morphemes. These improvements were sustained and generalized to conversations with familiar partners. The results demonstrate the positive effects of the conversation-based intervention for improving the expressive vocabulary and grammatical skills of children with severe motor speech disorders and expressive language delay who use augmentative and alternative communication. Clinical and theoretical implications of conversation-based interventions are discussed and future research needs are identified. https://doi.org/10.23641/asha.5150113.

Effects of a Conversation-Based Intervention on the Linguistic Skills of Children With Motor Speech Disorders Who Use Augmentative and Alternative Communication

PubMed Central

Clarke, Michael T.

2017-01-01

Purpose This study was conducted to evaluate the effects of a conversation-based intervention on the expressive vocabulary and grammatical skills of children with severe motor speech disorders and expressive language delay who use augmentative and alternative communication. Method Eight children aged from 8 to 13 years participated in the study. After a baseline period, a conversation-based intervention was provided for each participant, in which they were supported to learn and use linguistic structures essential for the formation of clauses and the grammaticalization of their utterances, such as pronouns, verbs, and bound morphemes, in the context of personally meaningful and scaffolded conversations with trained clinicians. The conversations were videotaped, transcribed, and analyzed using the Systematic Analysis of Language Transcripts (SALT; Miller & Chapman, 1991). Results Results indicate that participants showed improvements in their use of spontaneous clauses, and a greater use of pronouns, verbs, and bound morphemes. These improvements were sustained and generalized to conversations with familiar partners. Conclusion The results demonstrate the positive effects of the conversation-based intervention for improving the expressive vocabulary and grammatical skills of children with severe motor speech disorders and expressive language delay who use augmentative and alternative communication. Clinical and theoretical implications of conversation-based interventions are discussed and future research needs are identified. Supplemental Materials https://doi.org/10.23641/asha.5150113 PMID:28672283

The time-delayed inverted pendulum: Implications for human balance control

NASA Astrophysics Data System (ADS)

Milton, John; Cabrera, Juan Luis; Ohira, Toru; Tajima, Shigeru; Tonosaki, Yukinori; Eurich, Christian W.; Campbell, Sue Ann

2009-06-01

The inverted pendulum is frequently used as a starting point for discussions of how human balance is maintained during standing and locomotion. Here we examine three experimental paradigms of time-delayed balance control: (1) mechanical inverted time-delayed pendulum, (2) stick balancing at the fingertip, and (3) human postural sway during quiet standing. Measurements of the transfer function (mechanical stick balancing) and the two-point correlation function (Hurst exponent) for the movements of the fingertip (real stick balancing) and the fluctuations in the center of pressure (postural sway) demonstrate that the upright fixed point is unstable in all three paradigms. These observations imply that the balanced state represents a more complex and bounded time-dependent state than a fixed-point attractor. Although mathematical models indicate that a sufficient condition for instability is for the time delay to make a corrective movement, τn, be greater than a critical delay τc that is proportional to the length of the pendulum, this condition is satisfied only in the case of human stick balancing at the fingertip. Thus it is suggested that a common cause of instability in all three paradigms stems from the difficulty of controlling both the angle of the inverted pendulum and the position of the controller simultaneously using time-delayed feedback. Considerations of the problematic nature of control in the presence of delay and random perturbations ("noise") suggest that neural control for the upright position likely resembles an adaptive-type controller in which the displacement angle is allowed to drift for small displacements with active corrections made only when θ exceeds a threshold. This mechanism draws attention to an overlooked type of passive control that arises from the interplay between retarded variables and noise.

[The inner barrier: how health psychology concepts contribute to the explanation of prehospital delays in acute myocardial infarction: a systematic analysis of the current state of knowledge].

PubMed

Ladwig, Karl-Heinz; Gärtner, Cornelia; Walz, Linda Maria; Smenes, Kerstin Regina; Ronel, Joram

2009-12-01

During onset of an acute myocardial infarction (AMI), less than 20 % of patients reach the hospital within an optimal time window. About 75 % of pre-hospital delay time is caused by deficits in the patients' subjective decision making. To date, little is known about the course of threat appraisal during AMI. We aim to show here that health psychology related concepts offer an attractive conceptual frame to understand paradoxical reactions of AMI patients during this life threatening phase of their life. Only if patients overcome a complex network of barriers in perception and interpretation of symptoms, AMI symptoms will become effective as cues-to-action. Perception of symptoms may be compromised by a wide range of nociceptive stimuli originating from the heart. Symptom vagueness and a mismatch between expected and perceived symptoms may limit interpretation of the threat, yet active misattributing coping strategies may be even more present. Negative outcome expectancies and an impaired perceived self-efficacy, predominately in subjects with co-morbid negative affectivity are likely to contribute to delay.

Ohio River Denial as a Transportation Corridor and Its Economic Impacts on the Energy Industry

DTIC Science & Technology

2009-03-01

of freight transport market demand elasiticities, and mode choice probability elasticities of rail and full truck load carriers in the intercity ...obvious that under real conditions, travel demand would alter if time and duration of delay could be anticipated. First, cost of delay was defined...replication was expressed in terms of duration of the simulation interval, simulated travel time for this interval time, and expected travel time. Then

Salivary Alpha Amylase and Cortisol Levels in Children with Global Developmental Delay and Their Relation with the Expectation of Dental Care and Behavior during the Intervention

ERIC Educational Resources Information Center

dos Santos, Marcio Jose Possari; Bernabe, Daniel Galera; Nakamune, Ana Claudia de Melo Stevanato; Perri, Silvia Helena Venturoli; de Aguiar, Sandra Maria Herondina Coelho Avila; de Oliveira, Sandra Helena Penha

2012-01-01

The purpose of this study was to analyze the alpha-amylase (sAA) and cortisol levels in children with Global developmental delay (GDD) before and after dental treatment and its association with the children's behavior during treatment. The morning salivary cortisol levels and activity of sAA of 33 children with GDD were evaluated before and after…

Heterogeneity of residuals from comparison of GNSS and raytracing based troposphere slant total delays, as an indicator of hydrometeors

NASA Astrophysics Data System (ADS)

Hordyniec, Paweł; Rohm, Witold; Kapłon, Jan

2017-04-01

Post-fit residuals from Precise Point Positioning (PPP) carry the troposphere information except of multipath and residual antenna Phase Centre Variations (PCVs), when precise satellite orbits and clocks were introduced. Slant total delay (STD) of GNSS signal is a sum of a priori slant hydrostatic delay, estimated wet delay, asymetry introduced by the estimated zenith total delay (ZTD) horizontal gradients and a post-fit residual reduced by the systematic (site-dependant) effect. It was revealed, that application of reduced post-fit residuls to the slant total delays obtained from GNSS data processing increases the discrepancy with slant delays from raytracing (RT) through the Numerical Weather Model (NWM). One of the possible sources of that effect is neglected influence of hydrometeors in raytracing procedures. If the assumption of hydrometeor information existence in the PPP post-fit residuals is correct, we expect the diversity of slant delay discrepancies for satellite-receiver rays pointing or not the hydrometeors. Paper presents the spatial and temporal correlation analysis of the slant delay residuals (GNSS - RT) with hydrometeor phenomena recorded during the COST ES1206 GNSS4SWEC benchmark period (May 5th - June 29th, 2013). It presents the discussion of the results from different GNSS PPP slant delay estimation approaches including coordinates unconstraining or heavy constraining, and the calculation of slant delays with and without ZTD horizontal gradients estimation.

Effect of attochirp on attosecond streaking time delay in photoionization of atoms

NASA Astrophysics Data System (ADS)

Goldsmith, C.; Jaroń-Becker, A.; Becker, A.

2018-01-01

We present a theoretical analysis of the effect of the attochirp on the streaking time delay, intrinsic to photoionization of an atom by an attosecond laser pulse at extreme ultraviolet wavelengths superposed by a femtosecond streaking pulse. To this end, we determine the expectation value of the delay in a chirped pulse using a recently developed model formula. Results of our calculations show that the attochirp can be relevant for photoemission from the 3p shell in argon atom at frequencies near the Cooper minimum, while it is negligible if the photoionization cross section as a function of frequency varies smoothly.

Measurement of optical to electrical and electrical to optical delays with ps-level uncertainty.

PubMed

Peek, H Z; Pinkert, T J; Jansweijer, P P M; Koelemeij, J C J

2018-05-28

We present a new measurement principle to determine the absolute time delay of a waveform from an optical reference plane to an electrical reference plane and vice versa. We demonstrate a method based on this principle with 2 ps uncertainty. This method can be used to perform accurate time delay determinations of optical transceivers used in fiber-optic time-dissemination equipment. As a result the time scales in optical and electrical domain can be related to each other with the same uncertainty. We expect this method will be a new breakthrough in high-accuracy time transfer and absolute calibration of time-transfer equipment.

Timing and adequate attendance of antenatal care visits among women in Ethiopia.

PubMed

Yaya, Sanni; Bishwajit, Ghose; Ekholuenetale, Michael; Shah, Vaibhav; Kadio, Bernard; Udenigwe, Ogochukwu

2017-01-01

Although ANC services are increasingly available to women in low and middle-income countries, their inadequate use persists. This suggests a misalignment between aims of the services and maternal beliefs and circumstances. Owing to the dearth of studies examining the timing and adequacy of content of care, this current study aims to investigate the timing and frequency of ANC visits in Ethiopia. Data was obtained from the nationally representative 2011 Ethiopian Demographic and Health Survey (EDHS) which used a two-stage cluster sampling design to provide estimates for the health and demographic variables of interest for the country. Our study focused on a sample of 10,896 women with history of at least one childbirth event. Percentages of timing and adequacy of ANC visits were conducted across the levels of selected factors. Variables which were associated at 5% significance level were examined in the multivariable logistic regression model for association between timing and frequency of ANC visits and the explanatory variables while controlling for covariates. Furthermore, we presented the approach to estimate marginal effects involving covariate-adjusted logistic regression with corresponding 95%CI of delayed initiation of ANC visits and inadequate ANC attendance. The method used involved predicted probabilities added up to a weighted average showing the covariate distribution in the population. Results indicate that 66.3% of women did not use ANC at first trimester and 22.3% had ANC less than 4 visits. The results of this study were unique in that the association between delayed ANC visits and adequacy of ANC visits were examined using multivariable logistic model and the marginal effects using predicted probabilities. Results revealed that older age interval has higher odds of inadequate ANC visits. More so, type of place of residence was associated with delayed initiation of ANC visits, with rural women having the higher odds of delayed initiation of ANC visits (OR = 1.65; 95%CI: 1.26-2.18). However, rural women had 44% reduction in the odds of having inadequate ANC visits. In addition, multi-parity showed higher odds of delayed initiation of ANC visit when compared to the primigravida (OR = 2.20; 95%CI: 1.07-2.69). On the contrary, there was 36% reduction in the odds of multigravida having inadequate ANC visits when compared to the women who were primigravida. There were higher odds of inadequacy in ANC visits among women who engaged in sales/business, agriculture, skilled manual and other jobs when compared to women who currently do not work, after adjusting for covariates. From the predictive margins, assuming the distribution of all covariates remained the same among respondents, but everyone was aged 15-19 years, we would expect 71.8% delayed initiation of ANC visit. If everyone was aged 20-24years, 73.4%; 25-29years, 66.5%; 30-34years, 64.8%; 35-39years, 65.6%; 40-44years, 59.6% and 45-49years, we would expect 70.1% delayed initiation of ANC visit. If instead the distribution of age was as observed and for other covariates remained the same among respondents, but no respondent lived in the rural, we would expect about 61.4% delayed initiation of ANC visit; if however, everyone lived in the rural, and we would expect 71.6% delayed initiation in ANC visit. Model III revealed the predictive margins of all factors examined for delayed initiation for ANC visits, while Model IV presented the predictive marginal effects of the determinants of adequacy of ANC visits. The precise mechanism by which these factors affect ANC visits remain blurred at best. There may be factors on the demand side like the women's empowerment, financial support of the husband, knowledge of ANC visits in the context of timing, frequency and the expectations of ANC visits might be mediating the effects through the factors found associated in this study. Supply side factors like the quality of ANC services, skilled staff, and geographic location of the health centers also mediate their effects through the highlighted factors. Irrespective of the knowledge about the precise mechanism of action, policy makers could focus on improving women's empowerment, improving women's education, reducing wealth inequity and facilitating improved utilization of ANC through modifications on the supply side factors such as geographic location and focus on hard to reach women.

Adaptive iterative learning control of a class of nonlinear time-delay systems with unknown backlash-like hysteresis input and control direction.

PubMed

Wei, Jianming; Zhang, Youan; Sun, Meimei; Geng, Baoliang

2017-09-01

This paper presents an adaptive iterative learning control scheme for a class of nonlinear systems with unknown time-varying delays and control direction preceded by unknown nonlinear backlash-like hysteresis. Boundary layer function is introduced to construct an auxiliary error variable, which relaxes the identical initial condition assumption of iterative learning control. For the controller design, integral Lyapunov function candidate is used, which avoids the possible singularity problem by introducing hyperbolic tangent funciton. After compensating for uncertainties with time-varying delays by combining appropriate Lyapunov-Krasovskii function with Young's inequality, an adaptive iterative learning control scheme is designed through neural approximation technique and Nussbaum function method. On the basis of the hyperbolic tangent function's characteristics, the system output is proved to converge to a small neighborhood of the desired trajectory by constructing Lyapunov-like composite energy function (CEF) in two cases, while keeping all the closed-loop signals bounded. Finally, a simulation example is presented to verify the effectiveness of the proposed approach. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Factors affecting presentation and delay in patients with testicular cancer: results of a qualitative study.

PubMed

Gascoigne, P; Mason, M D; Roberts, E

1999-01-01

A qualitative study was undertaken with men treated for testicular tumours, to ascertain how they interpreted their symptoms and the factors which influenced a decision to consult a physician. The research was undertaken with six men who had been diagnosed as having testicular tumours. Interviews were also conducted with four wives and one mother. The findings showed that giving men information on testicular cancer may not guarantee early presentation. Symptoms were not generally attributed to cancer and the one patient who practised self-examination had delayed seeking help for 6 months. The extent to which symptoms affected the patient's lifestyle was also a factor in the decision-making process, as was the checking of symptoms with other family members. Wives were often pivotal in persuading men to seek help. The discovery of testicular symptoms produced emotional responses which included embarrassment and fear of both cancer and castration. There was evidence of strong feelings of masculine identity bound up with the appearance of 'normal' genitals. Provider-delay was identified in four cases and was associated with misattribution of symptoms by physicians and the failure to initiate specialist referral. Delay was under-recorded in the hospital notes in all cases where presentation was not immediate.

Use of the VLBI delay observable for orbit determination of Earth-orbiting VLBI satellites

NASA Technical Reports Server (NTRS)

Ulvestad, J. S.

1992-01-01

Very long-baseline interferometry (VLBI) observations using a radio telescope in Earth orbit were performed first in the 1980s. Two spacecraft dedicated to VLBI are scheduled for launch in 1995; the primary scientific goals of these missions will be astrophysical in nature. This article addresses the use of space VLBI delay data for the additional purpose of improving the orbit determination of the Earth-orbiting spacecraft. In an idealized case of quasi-simultaneous observations of three radio sources in orthogonal directions, analytical expressions are found for the instantaneous spacecraft position and its error. The typical position error is at least as large as the distance corresponding to the delay measurement accuracy but can be much greater for some geometries. A number of practical considerations, such as system noise and imperfect calibrations, set bounds on the orbit-determination accuracy realistically achievable using space VLBI delay data. These effects limit the spacecraft position accuracy to at least 35 cm (and probably 3 m or more) for the first generation of dedicated space VLBI experiments. Even a 35-cm orbital accuracy would fail to provide global VLBI astrometry as accurate as ground-only VLBI. Recommended charges in future space VLBI missions are unlikely to make space VLBI competitive with ground-only VLBI in global astrometric measurements.

[Waiting list in general and digestive surgery: patient expectations, quality of life during waiting time and overall satisfaction].

PubMed

Parés, D; Duran, E; Hermoso, J; Comajuncosas, J; Gris, P; Lopez-Negre, J L; Urgellés, J; Orbeal, R; Vallverdú, H; Jimeno, J

2013-01-01

The structural resources of the National Health system are limited, and therefore early surgery cannot be performed on all patients. The objective was to analyse the satisfaction perceived by the patient as regards the delay of treatment by waiting list of three types of surgery. The influence of expectations on waiting times, and impaired quality of life due to the clinical symptoms during the delay, were studied. A prospective study was conducted using a postal questionnaire. We compared the expectations (scale of 1 to 5), the impact on quality of life for symptoms (scale of 1 to 5) and the level of patient satisfaction (scale of 1 to 5) with respect to time on the waitng list for cholelithiasis, inguinal hernia and haemorrhoids. The predictors of patient dissatisfaction were analysed. A total of 57 patients were included. When comparing the characteristics of patients with and without satisfaction over time on the waiting list, days on the waiting list (P=.044), the change in the quality of life due to the symptoms (P=.028), and expectations (P<.001) were significantly different between the two groups. In the multivariate analysis, the expectation was associated with patient dissatisfaction as regards the time on waiting list (OR: 3.14 95% CI: 5.91 to 220.73, P<.001). The level of patient dissatisfaction is associated with expectations about time in waiting list. Copyright © 2012 SECA. Published by Elsevier Espana. All rights reserved.

A Reward-Maximizing Spiking Neuron as a Bounded Rational Decision Maker.

PubMed

Leibfried, Felix; Braun, Daniel A

2015-08-01

Rate distortion theory describes how to communicate relevant information most efficiently over a channel with limited capacity. One of the many applications of rate distortion theory is bounded rational decision making, where decision makers are modeled as information channels that transform sensory input into motor output under the constraint that their channel capacity is limited. Such a bounded rational decision maker can be thought to optimize an objective function that trades off the decision maker's utility or cumulative reward against the information processing cost measured by the mutual information between sensory input and motor output. In this study, we interpret a spiking neuron as a bounded rational decision maker that aims to maximize its expected reward under the computational constraint that the mutual information between the neuron's input and output is upper bounded. This abstract computational constraint translates into a penalization of the deviation between the neuron's instantaneous and average firing behavior. We derive a synaptic weight update rule for such a rate distortion optimizing neuron and show in simulations that the neuron efficiently extracts reward-relevant information from the input by trading off its synaptic strengths against the collected reward.

Uncertainty relations as Hilbert space geometry

NASA Technical Reports Server (NTRS)

Braunstein, Samuel L.

1994-01-01

Precision measurements involve the accurate determination of parameters through repeated measurements of identically prepared experimental setups. For many parameters there is a 'natural' choice for the quantum observable which is expected to give optimal information; and from this observable one can construct an Heinsenberg uncertainty principle (HUP) bound on the precision attainable for the parameter. However, the classical statistics of multiple sampling directly gives us tools to construct bounds for the precision available for the parameters of interest (even when no obvious natural quantum observable exists, such as for phase, or time); it is found that these direct bounds are more restrictive than those of the HUP. The implication is that the natural quantum observables typically do not encode the optimal information (even for observables such as position, and momentum); we show how this can be understood simply in terms of the Hilbert space geometry. Another striking feature of these bounds to parameter uncertainty is that for a large enough number of repetitions of the measurements all V quantum states are 'minimum uncertainty' states - not just Gaussian wave-packets. Thus, these bounds tell us what precision is achievable as well as merely what is allowed.

Frequency dependence of sensitivities in second-order RC active filters

NASA Astrophysics Data System (ADS)

Kunieda, T.; Hiramatsu, Y.; Fukui, A.

1980-02-01

This paper presents that gain and phase sensitivities to some element in biquadratic filters approximately constitute a circle on the complex sensitivity plane, provided that the quality factor Q of the circuit is appreciably larger than unity. Moreover, the group delay sensitivity is represented by the imaginary part of a cardioid. Using these results, bounds of maximum values of gain, phase, and group delay sensitivities are obtained. Further, it is proved that the maximum values of these sensitivities can be simultaneously minimized by minimizing the absolute value of the transfer function sensitivity at the center frequency provided that w(0)-sensitivities are constant and do not contain design parameters. Next, a statistical variability measure for the optimal-filter design is proposed. Finally, the relation between some variability measures proposed to the present time is made clear.

Resignation Syndrome: Catatonia? Culture-Bound?

PubMed Central

Sallin, Karl; Lagercrantz, Hugo; Evers, Kathinka; Engström, Ingemar; Hjern, Anders; Petrovic, Predrag

2016-01-01

Resignation syndrome (RS) designates a long-standing disorder predominately affecting psychologically traumatized children and adolescents in the midst of a strenuous and lengthy migration process. Typically a depressive onset is followed by gradual withdrawal progressing via stupor into a state that prompts tube feeding and is characterized by failure to respond even to painful stimuli. The patient is seemingly unconscious. Recovery ensues within months to years and is claimed to be dependent on the restoration of hope to the family. Descriptions of disorders resembling RS can be found in the literature and the condition is unlikely novel. Nevertheless, the magnitude and geographical distribution stand out. Several hundred cases have been reported exclusively in Sweden in the past decade prompting the Swedish National Board of Health and Welfare to recognize RS as a separate diagnostic entity. The currently prevailing stress hypothesis fails to account for the regional distribution and contributes little to treatment. Consequently, a re-evaluation of diagnostics and treatment is required. Psychogenic catatonia is proposed to supply the best fit with the clinical presentation. Treatment response, altered brain metabolism or preserved awareness would support this hypothesis. Epidemiological data suggests culture-bound beliefs and expectations to generate and direct symptom expression and we argue that culture-bound psychogenesis can accommodate the endemic distribution. Last, we review recent models of predictive coding indicating how expectation processes are crucially involved in the placebo and nocebo effect, delusions and conversion disorders. Building on this theoretical framework we propose a neurobiological model of RS in which the impact of overwhelming negative expectations are directly causative of the down-regulation of higher order and lower order behavioral systems in particularly vulnerable individuals. PMID:26858615

An economic evaluation of planned immediate versus delayed birth for preterm prelabour rupture of membranes: findings from the PPROMT randomised controlled trial.

PubMed

Lain, S J; Roberts, C L; Bond, D M; Smith, J; Morris, J M

2017-03-01

This study is an economic evaluation of immediate birth compared with expectant management in women with preterm prelabour rupture of the membranes near term (PPROMT). A cost-effectiveness analysis alongside the PPROMT randomised controlled trial. Obstetric departments in 65 hospitals across 11 countries. Women with a singleton pregnancy with ruptured membranes between 34 +0 and 36 +6 weeks gestation. Women were randomly allocated to immediate birth or expectant management. Costs to the health system were identified and valued. National hospital costing data from both the UK and Australia were used. Average cost per recruit in each arm was calculated and 95% confidence intervals were estimated using bootstrap re-sampling. Averages costs during antenatal care, delivery and postnatal care, and by country were estimated. Total mean cost difference between immediate birth and expectant management arms of the trial. From 11 countries 923 women were randomised to immediate birth and 912 were randomised to expectant management. Total mean costs per recruit were £8852 for immediate birth and £8740 for expectant delivery resulting in a mean difference in costs of £112 (95% CI: -431 to 662). The expectant management arm had significantly higher antenatal costs, whereas the immediate birth arm had significantly higher delivery and neonatal costs. There was large variation between total mean costs by country. This economic evaluation found no evidence that expectant management was more or less costly than immediate birth. Outpatient management may offer opportunities for cost savings for those women with delayed delivery. For women with preterm prelabour rupture of the membranes, the relative benefits and harms of immediate and expectant management should inform counselling as costs are similar. © 2016 Royal College of Obstetricians and Gynaecologists.

Bounds on the minimum number of recombination events in a sample history.

PubMed Central

Myers, Simon R; Griffiths, Robert C

2003-01-01

Recombination is an important evolutionary factor in many organisms, including humans, and understanding its effects is an important task facing geneticists. Detecting past recombination events is thus important; this article introduces statistics that give a lower bound on the number of recombination events in the history of a sample, on the basis of the patterns of variation in the sample DNA. Such lower bounds are appropriate, since many recombination events in the history are typically undetectable, so the true number of historical recombinations is unobtainable. The statistics can be calculated quickly by computer and improve upon the earlier bound of Hudson and Kaplan 1985. A method is developed to combine bounds on local regions in the data to produce more powerful improved bounds. The method is flexible to different models of recombination occurrence. The approach gives recombination event bounds between all pairs of sites, to help identify regions with more detectable recombinations, and these bounds can be viewed graphically. Under coalescent simulations, there is a substantial improvement over the earlier method (of up to a factor of 2) in the expected number of recombination events detected by one of the new minima, across a wide range of parameter values. The method is applied to data from a region within the lipoprotein lipase gene and the amount of detected recombination is substantially increased. Further, there is strong clustering of detected recombination events in an area near the center of the region. A program implementing these statistics, which was used for this article, is available from http://www.stats.ox.ac.uk/mathgen/programs.html. PMID:12586723

The Cramér-Rao Bounds and Sensor Selection for Nonlinear Systems with Uncertain Observations.

PubMed

Wang, Zhiguo; Shen, Xiaojing; Wang, Ping; Zhu, Yunmin

2018-04-05

This paper considers the problems of the posterior Cramér-Rao bound and sensor selection for multi-sensor nonlinear systems with uncertain observations. In order to effectively overcome the difficulties caused by uncertainty, we investigate two methods to derive the posterior Cramér-Rao bound. The first method is based on the recursive formula of the Cramér-Rao bound and the Gaussian mixture model. Nevertheless, it needs to compute a complex integral based on the joint probability density function of the sensor measurements and the target state. The computation burden of this method is relatively high, especially in large sensor networks. Inspired by the idea of the expectation maximization algorithm, the second method is to introduce some 0-1 latent variables to deal with the Gaussian mixture model. Since the regular condition of the posterior Cramér-Rao bound is unsatisfied for the discrete uncertain system, we use some continuous variables to approximate the discrete latent variables. Then, a new Cramér-Rao bound can be achieved by a limiting process of the Cramér-Rao bound of the continuous system. It avoids the complex integral, which can reduce the computation burden. Based on the new posterior Cramér-Rao bound, the optimal solution of the sensor selection problem can be derived analytically. Thus, it can be used to deal with the sensor selection of a large-scale sensor networks. Two typical numerical examples verify the effectiveness of the proposed methods.

Does NGAL reduce costs? A cost analysis of urine NGAL (uNGAL) & serum creatinine (sCr) for acute kidney injury (AKI) diagnosis.

PubMed

Parikh, Amay; Rizzo, John A; Canetta, Pietro; Forster, Catherine; Sise, Meghan; Maarouf, Omar; Singer, Eugenia; Elger, Antje; Elitok, Saban; Schmidt-Ott, Kai; Barasch, Jonathon; Nickolas, Thomas L

2017-01-01

Urine neutrophil gelatinase-associated lipocalin (uNGAL) is a sensitive and specific diagnostic test for acute kidney injury (AKI) in the Emergency Department (ED), but its economic impact has not been investigated. We hypothesized that uNGAL used in combination with serum creatinine (sCr) would reduce costs in the management of AKI in patients presenting to the ED in comparison to using sCr alone. A cost simulation model was developed for clinical algorithms to diagnose AKI based on sCr alone vs. uNGAL plus sCr (uNGAL+sCr). A cost minimization analysis was performed to determine total expected costs for patients with AKI. uNGAL test characteristics were validated with eight-hundred forty-nine patients with sCr ≥1.5 from a completed study of 1635 patients recruited from EDs at two U.S. hospitals from 2007-8. Biomarker test, AKI work-up, and diagnostic imaging costs were incorporated. For a hypothetical cohort of 10,000 patients, the model predicted that the expected costs were $900 per patient (pp) in the sCr arm and $950 in the uNGAL+sCr arm. uNGAL+sCr resulted in 1,578 fewer patients with delayed diagnosis and treatment than sCr alone (2,013 vs. 436 pts) at center 1 and 1,973 fewer patients with delayed diagnosis and treatment than sCr alone at center 2 (2,227 vs. 254 patients). Although initial evaluation costs at each center were $50 pp higher in with uNGAL+sCr, total costs declined by $408 pp at Center 1 and by $522 pp at Center 2 due to expected reduced delays in diagnosis and treatment. Sensitivity analyses confirmed savings with uNGAL + sCr for a range of cost inputs. Using uNGAL with sCr as a clinical diagnostic test for AKI may improve patient management and reduce expected costs. Any cost savings would likely result from avoiding delays in diagnosis and treatment and from avoidance of unnecessary testing in patients given a false positive AKI diagnosis by use of sCr alone.

Toward allocative efficiency in the prescription drug industry.

PubMed

Guell, R C; Fischbaum, M

1995-01-01

Traditionally, monopoly power in the pharmaceutical industry has been measured by profits. An alternative method estimates the deadweight loss of consumer surplus associated with the exercise of monopoly power. Although upper and lower bound estimates for this inefficiency are far apart, they at least suggest a dramatically greater welfare loss than measures of industry profitability would imply. A proposed system would have the U.S. government employing its power of eminent domain to "take" and distribute pharmaceutical patents, providing as "just compensation" the present value of the patent's expected future monopoly profits. Given the allocative inefficiency of raising taxes to pay for the program, the impact of the proposal on allocative efficiency would be at least as good at our lower bound estimate of monopoly costs while substantially improving efficiency at or near our upper bound estimate.

Quasi-soliton scattering in quantum spin chains

NASA Astrophysics Data System (ADS)

Vlijm, R.; Ganahl, M.; Fioretto, D.; Brockmann, M.; Haque, M.; Evertz, H. G.; Caux, J.-S.

2015-12-01

The quantum scattering of magnon bound states in the anisotropic Heisenberg spin chain is shown to display features similar to the scattering of solitons in classical exactly solvable models. Localized colliding Gaussian wave packets of bound magnons are constructed from string solutions of the Bethe equations and subsequently evolved in time, relying on an algebraic Bethe ansatz based framework for the computation of local expectation values in real space-time. The local magnetization profile shows the trajectories of colliding wave packets of bound magnons, which obtain a spatial displacement upon scattering. Analytic predictions on the displacements for various values of anisotropy and string lengths are derived from scattering theory and Bethe ansatz phase shifts, matching time-evolution fits on the displacements. The time-evolved block decimation algorithm allows for the study of scattering displacements from spin-block states, showing similar scattering displacement features.

Quasi-soliton scattering in quantum spin chains

NASA Astrophysics Data System (ADS)

Fioretto, Davide; Vljim, Rogier; Ganahl, Martin; Brockmann, Michael; Haque, Masud; Evertz, Hans-Gerd; Caux, Jean-Sébastien

The quantum scattering of magnon bound states in the anisotropic Heisenberg spin chain is shown to display features similar to the scattering of solitons in classical exactly solvable models. Localized colliding Gaussian wave packets of bound magnons are constructed from string solutions of the Bethe equations and subsequently evolved in time, relying on an algebraic Bethe ansatz based framework for the computation of local expectation values in real space-time. The local magnetization profile shows the trajectories of colliding wave packets of bound magnons, which obtain a spatial displacement upon scattering. Analytic predictions on the displacements for various values of anisotropy and string lengths are derived from scattering theory and Bethe ansatz phase shifts, matching time evolution fits on the displacements. The TEBD algorithm allows for the study of scattering displacements from spin-block states, showing similar displacement scattering features.

β-delayed γ decay of 20Mg and the 19Ne(p , γ) 20 Na breakout reaction in Type I X-ray bursts

NASA Astrophysics Data System (ADS)

Glassman, B. E.; Pérez-Loureiro, D.; Wrede, C.; Allen, J.; Bardayan, D. W.; Bennett, M. B.; Brown, B. A.; Chipps, K. A.; Febbraro, M.; Friedman, M.; Fry, C.; Hall, M. R.; Hall, O.; Liddick, S. N.; O'Malley, P.; Ong, W. J.; Pain, S. D.; Prokop, C.; Schwartz, S. B.; Shidling, P.; Sims, H.; Thompson, P.; Zhang, H.

2018-03-01

Certain astrophysical environments such as thermonuclear outbursts on accreting neutron stars (Type-I X-ray bursts) are hot enough to allow for breakout from the Hot CNO hydrogen burning cycles to the rapid proton capture (rp) process. An important breakout reaction sequence is 15O(α,γ)19Ne(p,γ)20Na and the 19Ne(p,γ)20Na reaction rate is expected to be dominated by a single resonance at 457 keV above the proton threshold in 20Na. The resonance strength and, hence, reaction rate depends strongly on whether this 20Na state at an excitation energy of 2647 keV has spin and parity of 1+ or 3+. Previous 20Mg (Jπ =0+) β+ decay experiments have relied almost entirely on searches for β-delayed proton emission from this resonance in 20Na to limit the log ft value and, hence, Jπ. However there is a non-negligible γ-ray branch expected that must also be limited experimentally to determine the log ft value and constrain Jπ. We have measured the β-delayed γ decay of 20Mg to complement previous β-delayed proton decay work and provide the first complete limit based on all energetically allowed decay channels through the 2647 keV state. Our limit confirms that a 1+ assignment for this state is highly unlikely.

Spectral Changes of Erythrosin B Luminescence Upon Binding to Bovine Serum Albumin

NASA Astrophysics Data System (ADS)

Sablin, N. V.; Gerasimova, M. A.; Nemtseva, E. V.

2016-04-01

Changes in absorption, fluorescence, phosphorescence, and delayed fluorescence spectra of erythrosin B are studied in the presence of bovine serum albumin at room temperature. Spectral and chronoscopic characteristics of the observed photophysical processes are defined. The binding of erythrosin B with the protein followed by spectral changes is demonstrated. Absorption and fluorescence spectra of the dye in the bound state are described, the binding mechanism is analyzed. The binding parameters of the dye-protein complex are estimated.

Unclassified Publications of Lincoln Laboratory, 1 January - 31 December 1991. Volume 17

DTIC Science & Technology

1991-12-31

FIBER OPTIC ANALOG LINK MS-9183 MS-8873 FABRY - PEROT LASER FIBER OPTIC APPLICATIONS JA-6656 JA-6686 FABRY - PEROT SCANNING FIBER OPTIC LINK JA-6567 MS...8532, MS-9353 FABRY - PEROT SPECTRUM ANALYZER FIBER OPTICS TECHNOLOGY JA-6682 JA-6458 FAR-FIELD BEAM DIVERGENCE FIELD EFFECT TRANSISTORS JA-6505 JA-6662...8734 JA-6604, JA-6680 CRAMER-RAO LOWER BOUND DELAY LINES JA-6461 MS-8890 CROSS-CORRELATION DEMODULATION MS-8734 TR-91 0 CROSSLINK DEPOSITION METHODS JA

Open Smart Energy Gateway (OpenSEG)

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

The Open Smart Energy Gateway (OpenSEG) aims to provide near-real time smart meter data to consumers without the delays or latencies associated with it being transported to the utility data center and then back to the consumer's application. To do this, the gateway queries the local Smart Meter to which it is bound to get energy consumption information at pre-defined intervals (minimum interval is 4 seconds). OpenSEG then stores the resulting data internally for retrieval by an external application.

On the rarity of X-ray binaries with Wolf-Rayet donors

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

Linden, T.; Valsecchi, F.; Kalogera, V.

The paucity of High mass X-Ray binaries (HMXB) consisting of a neutron star (NS) accretor and Wolf-Rayet (WR) donor has long been at odds with expectations from population synthesis studies indicating that these systems should survive as the evolved offspring of the observed HMXB population. This tension is particularly troubling in light of recent observations uncovering a preponderance of HMXBs containing loosely bound Be donors which would be expected to naturally evolve into WR-HMXBs. Reconciling the unexpectedly large population of Be-HMXBs with the lack of observed WR-HMXB sources thus serves to isolate the dynamics of CE physics from other binarymore » evolution parameters. We find that binary mergers during CE events must be common in order to resolve tension between these observed populations. Furthermore, future observations which better constrain the background population of loosely bound O/B-NS binaries are likely to place significant constraints on the efficiency of CE removal.« less

Designed Long‐Lived Emission from CdSe Quantum Dots through Reversible Electronic Energy Transfer with a Surface‐Bound Chromophore

PubMed Central

La Rosa, Marcello; Denisov, Sergey A.

2018-01-01

Abstract The size‐tunable emission of luminescent quantum dots (QDs) makes them highly interesting for applications that range from bioimaging to optoelectronics. For the same applications, engineering their luminescence lifetime, in particular, making it longer, would be as important; however, no rational approach to reach this goal is available to date. We describe a strategy to prolong the emission lifetime of QDs through electronic energy shuttling to the triplet excited state of a surface‐bound molecular chromophore. To implement this idea, we made CdSe QDs of different sizes and carried out self‐assembly with a pyrene derivative. We observed that the conjugates exhibit delayed luminescence, with emission decays that are prolonged by more than 3 orders of magnitude (lifetimes up to 330 μs) compared to the parent CdSe QDs. The mechanism invokes unprecedented reversible quantum dot to organic chromophore electronic energy transfer. PMID:29383800

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

Allahverdi, Rouzbeh; Gao, Yu; Knockel, Bradley

In this paper, we study indirect detection signals from solar annihilation of dark matter (DM) particles into light right-handed (RH) neutrinos with a mass in a 1–5 GeV range. These RH neutrinos can have a sufficiently long lifetime to allow them to decay outside the Sun, and their delayed decays can result in a signal in gamma rays from the otherwise “dark” solar direction, and also a neutrino signal that is not suppressed by the interactions with solar medium. We find that the latest Fermi-LAT and IceCube results place limits on the gamma ray and neutrino signals, respectively. Combined photonmore » and neutrino bounds can constrain the spin-independent DM-nucleon elastic scattering cross section better than direct detection experiments for DM masses from 200 GeV up to several TeV. Finally, the bounds on spin-dependent scattering are also much tighter than the strongest limits from direct detection experiments.« less

Analyzing the evolutionary mechanisms of the Air Transportation System-of-Systems using network theory and machine learning algorithms

NASA Astrophysics Data System (ADS)

Kotegawa, Tatsuya

Complexity in the Air Transportation System (ATS) arises from the intermingling of many independent physical resources, operational paradigms, and stakeholder interests, as well as the dynamic variation of these interactions over time. Currently, trade-offs and cost benefit analyses of new ATS concepts are carried out on system-wide evaluation simulations driven by air traffic forecasts that assume fixed airline routes. However, this does not well reflect reality as airlines regularly add and remove routes. A airline service route network evolution model that projects route addition and removal was created and combined with state-of-the-art air traffic forecast methods to better reflect the dynamic properties of the ATS in system-wide simulations. Guided by a system-of-systems framework, network theory metrics and machine learning algorithms were applied to develop the route network evolution models based on patterns extracted from historical data. Constructing the route addition section of the model posed the greatest challenge due to the large pool of new link candidates compared to the actual number of routes historically added to the network. Of the models explored, algorithms based on logistic regression, random forests, and support vector machines showed best route addition and removal forecast accuracies at approximately 20% and 40%, respectively, when validated with historical data. The combination of network evolution models and a system-wide evaluation tool quantified the impact of airline route network evolution on air traffic delay. The expected delay minutes when considering network evolution increased approximately 5% for a forecasted schedule on 3/19/2020. Performance trade-off studies between several airline route network topologies from the perspectives of passenger travel efficiency, fuel burn, and robustness were also conducted to provide bounds that could serve as targets for ATS transformation efforts. The series of analysis revealed that high robustness is achievable only in exchange of lower passenger travel and fuel burn efficiency. However, increase in the network density can mitigate this trade-off.

Logistic analysis of OBT dynamics.

PubMed

Baumgaertner, Franz; Yankovich, Tamara L; Kim, Sang Bog

2009-12-01

Formation and depuration of non-exchangeable organically bound tritium (OBT) is measured in mussel dry tissue on expanding time scales. The OBT course of time is analyzed by means of the Verhulst logistic growth function. Two separate routes are found as well for OBT formation as depuration, i.e., restoration of organically bound hydrogen (OBH). Routes which arrive at saturation earlier than sampling started are assigned to respiration. Other routes which start with one-day delay are attributed to metabolc pathways. The metabolic route of OBT formation includes, in addition to the logistic growth function, one rapid mechanism with

A Simple Network Architecture Accounts for Diverse Reward Time Responses in Primary Visual Cortex.

PubMed

Huertas, Marco A; Hussain Shuler, Marshall G; Shouval, Harel Z

2015-09-16

Many actions performed by animals and humans depend on an ability to learn, estimate, and produce temporal intervals of behavioral relevance. Exemplifying such learning of cued expectancies is the observation of reward-timing activity in the primary visual cortex (V1) of rodents, wherein neural responses to visual cues come to predict the time of future reward as behaviorally experienced in the past. These reward-timing responses exhibit significant heterogeneity in at least three qualitatively distinct classes: sustained increase or sustained decrease in firing rate until the time of expected reward, and a class of cells that reach a peak in firing at the expected delay. We elaborate upon our existing model by including inhibitory and excitatory units while imposing simple connectivity rules to demonstrate what role these inhibitory elements and the simple architectures play in sculpting the response dynamics of the network. We find that simply adding inhibition is not sufficient for obtaining the different distinct response classes, and that a broad distribution of inhibitory projections is necessary for obtaining peak-type responses. Furthermore, although changes in connection strength that modulate the effects of inhibition onto excitatory units have a strong impact on the firing rate profile of these peaked responses, the network exhibits robustness in its overall ability to predict the expected time of reward. Finally, we demonstrate how the magnitude of expected reward can be encoded at the expected delay in the network and how peaked responses express this reward expectancy. Heterogeneity in single-neuron responses is a common feature of neuronal systems, although sometimes, in theoretical approaches, it is treated as a nuisance and seldom considered as conveying a different aspect of a signal. In this study, we focus on the heterogeneous responses in the primary visual cortex of rodents trained with a predictable delayed reward time. We describe under what conditions this heterogeneity can arise by self-organization, and what information it can convey. This study, while focusing on a specific system, provides insight onto how heterogeneity can arise in general while also shedding light onto mechanisms of reinforcement learning using realistic biological assumptions. Copyright © 2015 the authors 0270-6474/15/3512659-14$15.00/0.

Tidal Love numbers of neutron and self-bound quark stars

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

Postnikov, Sergey; Prakash, Madappa; Lattimer, James M.

Gravitational waves from the final stages of inspiraling binary neutron stars are expected to be one of the most important sources for ground-based gravitational wave detectors. The masses of the components are determinable from the orbital and chirp frequencies during the early part of the evolution, and large finite-size (tidal) effects are measurable toward the end of inspiral, but the gravitational wave signal is expected to be very complex at this time. Tidal effects during the early part of the evolution will form a very small correction, but during this phase the signal is relatively clean. The accumulated phase shiftmore » due to tidal corrections is characterized by a single quantity related to a star's tidal Love number. The Love number is sensitive, in particular, to the compactness parameter M/R and the star's internal structure, and its determination could provide an important constraint to the neutron star radius. We show that Love numbers of self-bound strange quark matter stars are qualitatively different from those of normal neutron stars. Observations of the tidal signature from coalescing compact binaries could therefore provide an important, and possibly unique, way to distinguish self-bound strange quark stars from normal neutron stars. Tidal signatures from self-bound strange quark stars with masses smaller than 1M{sub {center_dot}}are substantially smaller than those of normal stars owing to their smaller radii. Thus tidal signatures of stars less massive than 1M{sub {center_dot}}are probably not detectable with Advanced LIGO. For stars with masses in the range 1-2M{sub {center_dot},} the anticipated efficiency of the proposed Einstein telescope would be required for the detection of tidal signatures.« less

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

NASA Astrophysics Data System (ADS)

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-01

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1-3 electrons, we include for the first time events corresponding to about 4-7 electrons. Assuming the scattering is momentum independent (FDM=1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4-50 electrons, and leads to a constraint that is comparable to the XENON10 bound above 50 MeV for FDM=1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data ("S2") data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.

W-Z-top-quark bags

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

Crichigno, Marcos P.; Shuryak, Edward; Flambaum, Victor V.

2010-10-01

We discuss a new family of multiquanta-bound states in the standard model which exist due to the mutual Higgs-based attraction of the heaviest members of the standard model, namely, gauge quanta W, Z, and (anti)top quarks, t, t. We use a self-consistent mean-field approximation, up to a rather large particle number N. In this paper we do not focus on weakly bound, nonrelativistic bound states, but rather on 'bags' in which the Higgs vacuum expectation value is significantly modified or depleted. The minimal number N above which such states appear strongly depends on the ratio of the Higgs mass tomore » the masses of W, Z, t, t: For a light Higgs mass, m{sub H{approx}}50 GeV, bound states start from N{approx}O(10), but for a ''realistic'' Higgs mass, m{sub H{approx}}100 GeV, one finds metastable/bound W, Z bags only for N{approx}O(1000). We also found that in the latter case pure top bags disappear for all N, although top quarks can still be well bound to the W bags. Anticipating the cosmological applications (discussed in the following Article [Phys. Rev. D 82, 073019]) of these bags as 'doorway states' for baryosynthesis, we also consider here the existence of such metastable bags at finite temperatures, when standard-model parameters such as Higgs, gauge, and top masses are significantly modified.« less

Micromachined silicon acoustic delay line with improved structural stability and acoustic directivity for real-time photoacoustic tomography

NASA Astrophysics Data System (ADS)

Cho, Young; Kumar, Akhil; Xu, Song; Zou, Jun

2017-03-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. However, as its length increases to provide longer delay time, the delay line becomes more vulnerable to structural instability due to reduced mechanical stiffness. In addition, the small cross-section area of the delay line results in a large acoustic acceptance angle and therefore poor directivity. To address these two issues, this paper reports the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, a new tapered design for the input terminal of the delay line was also investigate to improve its acoustic directivity by reducing the acoustic acceptance angle. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

Micromachined silicon acoustic delay line with 3D-printed micro linkers and tapered input for improved structural stability and acoustic directivity

NASA Astrophysics Data System (ADS)

Cho, Y.; Kumar, A.; Xu, S.; Zou, J.

2016-10-01

Recent studies have shown that micromachined silicon acoustic delay lines can provide a promising solution to achieve real-time photoacoustic tomography without the need for complex transducer arrays and data acquisition electronics. To achieve deeper imaging depth and wider field of view, a longer delay time and therefore delay length are required. However, as the length of the delay line increases, it becomes more vulnerable to structural instability due to reduced mechanical stiffness. In this paper, we report the design, fabrication, and testing of a new silicon acoustic delay line enhanced with 3D printed polymer micro linker structures. First, mechanical deformation of the silicon acoustic delay line (with and without linker structures) under gravity was simulated by using finite element method. Second, the acoustic crosstalk and acoustic attenuation caused by the polymer micro linker structures were evaluated with both numerical simulation and ultrasound transmission testing. The result shows that the use of the polymer micro linker structures significantly improves the structural stability of the silicon acoustic delay lines without creating additional acoustic attenuation and crosstalk. In addition, the improvement of the acoustic acceptance angle of the silicon acoustic delay lines was also investigated to better suppress the reception of unwanted ultrasound signals outside of the imaging plane. These two improvements are expected to provide an effective solution to eliminate current limitations on the achievable acoustic delay time and out-of-plane imaging resolution of micromachined silicon acoustic delay line arrays.

China's Progress toward Gender Equity: From Bound Feet to Boundless Possibilities

ERIC Educational Resources Information Center

Hagedorn, Linda Serra; Zhang, Yi

2010-01-01

Throughout the world, gender defines an omnipresent and personal identity. Historically gender effects have ventured far beyond the biological aspects of reproduction and deep into societal constraints of action, appearance, freedom, and destiny. Gender provides convenient labels, descriptions, and expectations. Unfortunately history provides many…

Power, Agency and Middle Leadership in English Primary Schools

ERIC Educational Resources Information Center

Hammersley-Fletcher, Linda; Strain, Michael

2011-01-01

English primary schools are considered quasi-collegial institutions within which staff communicate regularly and openly. The activities of staff, however, are bound by institutional norms and conditions and by societal expectations. Wider agendas of governmental control over the curriculum and external controls to ensure accountability and…

Near-toll quality digital speech transmission in the mobile satellite service

NASA Technical Reports Server (NTRS)

Townes, S. A.; Divsalar, D.

1986-01-01

This paper discusses system considerations for near-toll quality digital speech transmission in a 5 kHz mobile satellite system channel. Tradeoffs are shown for power performance versus delay for a 4800 bps speech compression system in conjunction with a 16 state rate 2/3 trellis coded 8PSK modulation system. The suggested system has an additional 150 ms of delay beyond the propagation delay and requires an E(b)/N(0) of about 7 dB for a Ricean channel assumption with line-of-sight to diffuse component ratio of 10 assuming ideal synchronization. An additional loss of 2 to 3 dB is expected for synchronization in fading environment.

Delocalization of frontier orbitals induced red emission for heptazine based thermally activated delayed fluorescence molecule: First-principles study

NASA Astrophysics Data System (ADS)

Kang, Yongxiang; Zhao, Liyun; Leng, Jiancai

2018-04-01

Design of red organic emitting molecules with characteristic of thermally activated delayed fluorescence (TADF) remains a great challenge. Here, electronic and optical properties of a series of multi-branched TADF molecules have been investigated based on the newly-proposed optimal Hartree-Fock percentage method. Results show that, though enlarging the delocalization of HOMO and LUMO, the emission wavelength is redshift. The designed red TADF molecule possesses smaller reorganization energy than these for reported molecules. This indicates the non-radiative energy consumption of excited state is small and effective luminescence can be expected. Thus, a promising red thermally activated delayed fluorescence molecule is proposed.

A longitudinal study of lexical and grammar development in deaf Italian children provided with early cochlear implantation.

PubMed

Chilosi, Anna Maria; Comparini, Alessandro; Scusa, Maria Flora; Orazini, Laura; Forli, Francesca; Cipriani, Paola; Berrettini, Stefano

2013-01-01

A growing number of studies on deaf children with cochlear implant (CI) document a significant improvement in receptive and expressive language skills after implantation, even if they show language delay when compared with normal-hearing peers. Data on language acquisition in CI Italian children are still scarce and limited to only certain aspects of language. The purpose of this study is to prospectively describe the trajectories of language development in early CI Italian children, with particular attention to the transition from first words to combinatorial speech and to acquisition of complex grammar in a language with rich morphology, such as Italian. Six children, with profound prelingual deafness, provided with CI, between 16 and 24 months of age were prospectively assessed and followed over a mean period of up to 34.8 months postimplant. During follow-up, each child received between four to five individual language evaluations through a combination of indirect procedures (parent reports of early lexical and grammar development) and direct ones (administration of standardized receptive and expressive language tests with Italian norms and collection of spontaneous language samples). In relation to chronological age, the acquisition of expressive vocabulary was delayed. However, considering the duration of hearing experience, most CI participants showed an earlier start and faster growth of expressive rather than receptive vocabulary in comparison with typically developing children. This quite atypical result persisted right up until the end of the follow-up. The acquisition of expressive grammar was delayed relative to chronological age, though all but one CI participant achieved the expected grammar level after approximately 3 years of CI use. In addition, the rate of grammar acquisition was not homogeneous during development, showing two different paces: one comparable with normal hearing in the transition from holophrastic to primitive combinatorial speech and a much slower one to attain more advanced levels of morphosyntactic control. From a rehabilitative viewpoint, our results suggest the importance of implementing rehabilitation in lexical comprehension, even when expressive vocabulary appears to be within normal range. Moreover, assessment of language acquisition in CI Italian children should focus on those grammar aspects that are more vulnerable to early acoustic deprivation (such as free and bound morphology) to ensure enhanced language therapy planning.

Detection of time delays and directional interactions based on time series from complex dynamical systems

NASA Astrophysics Data System (ADS)

Ma, Huanfei; Leng, Siyang; Tao, Chenyang; Ying, Xiong; Kurths, Jürgen; Lai, Ying-Cheng; Lin, Wei

2017-07-01

Data-based and model-free accurate identification of intrinsic time delays and directional interactions is an extremely challenging problem in complex dynamical systems and their networks reconstruction. A model-free method with new scores is proposed to be generally capable of detecting single, multiple, and distributed time delays. The method is applicable not only to mutually interacting dynamical variables but also to self-interacting variables in a time-delayed feedback loop. Validation of the method is carried out using physical, biological, and ecological models and real data sets. Especially, applying the method to air pollution data and hospital admission records of cardiovascular diseases in Hong Kong reveals the major air pollutants as a cause of the diseases and, more importantly, it uncovers a hidden time delay (about 30-40 days) in the causal influence that previous studies failed to detect. The proposed method is expected to be universally applicable to ascertaining and quantifying subtle interactions (e.g., causation) in complex systems arising from a broad range of disciplines.

Adaptive Baseline Enhances EM-Based Policy Search: Validation in a View-Based Positioning Task of a Smartphone Balancer

PubMed Central

Wang, Jiexin; Uchibe, Eiji; Doya, Kenji

2017-01-01

EM-based policy search methods estimate a lower bound of the expected return from the histories of episodes and iteratively update the policy parameters using the maximum of a lower bound of expected return, which makes gradient calculation and learning rate tuning unnecessary. Previous algorithms like Policy learning by Weighting Exploration with the Returns, Fitness Expectation Maximization, and EM-based Policy Hyperparameter Exploration implemented the mechanisms to discard useless low-return episodes either implicitly or using a fixed baseline determined by the experimenter. In this paper, we propose an adaptive baseline method to discard worse samples from the reward history and examine different baselines, including the mean, and multiples of SDs from the mean. The simulation results of benchmark tasks of pendulum swing up and cart-pole balancing, and standing up and balancing of a two-wheeled smartphone robot showed improved performances. We further implemented the adaptive baseline with mean in our two-wheeled smartphone robot hardware to test its performance in the standing up and balancing task, and a view-based approaching task. Our results showed that with adaptive baseline, the method outperformed the previous algorithms and achieved faster, and more precise behaviors at a higher successful rate. PMID:28167910

ON THE RARITY OF X-RAY BINARIES WITH NAKED HELIUM DONORS

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

Linden, T.; Valsecchi, F.; Kalogera, V.

The paucity of known high-mass X-ray binaries (HMXBs) with naked He donor stars (hereafter He star) in the Galaxy has been noted over the years as a surprising fact, given the significant number of Galactic HMXBs containing H-rich donors, which are expected to be their progenitors. This contrast has further sharpened in light of recent observations uncovering a preponderance of HMXBs hosting loosely bound Be donors orbiting neutron stars (NSs), which would be expected to naturally evolve into He-HMXBs through dynamical mass transfer onto the NS and a common-envelope (CE) phase. Hence, reconciling the large population of Be-HMXBs with themore » observation of only one He-HMXB can help constrain the dynamics of CE physics. Here, we use detailed stellar structure and evolution models and show that binary mergers of HMXBs during CE events must be common in order to resolve the tension between these observed populations. We find that, quantitatively, this scenario remains consistent with the typically adopted energy parameterization of CE evolution, yielding expected populations which are not at odds with current observations. However, future observations which better constrain the underlying population of loosely bound O/B-NS binaries are likely to place significant constraints on the efficiency of CE ejection.« less

Calculation of energy-deposition distributions and microdosimetric estimation of the biological effect of a 9C beam.

PubMed

Mancusi, Davide; Sihver, Lembit; Niita, Koji; Li, Qiang; Sato, Tatsuhiko; Iwase, Hiroshi; Iwamoto, Yosuke; Matsuda, Norihiro; Sakamoto, Yukio; Nakashima, Hiroshi

2009-04-01

Among the alternative beams being recently considered for external cancer radiotherapy, (9)C has received some attention because it is expected that its biological effectiveness could be boosted by the beta-delayed emission of two alpha particles and a proton that takes place at the ion-stopping site. Experiments have been performed to characterise this exotic beam physically and models have been developed to estimate quantitatively its biological effect. Here, the particle and heavy-ion transport code system ( PHITS ) is used to calculate energy-deposition and linear energy transfer distributions for a (9)C beam in water and the results are compared with published data. Although PHITS fails to reproduce some of the features of the distributions, it suggests that the decay of (9)C contributes negligibly to the energy-deposition distributions, thus contradicting the previous interpretation of the measured data. We have also performed a microdosimetric calculation to estimate the biological effect of the decay, which was found to be negligible; previous microdosimetric Monte-Carlo calculations were found to be incorrect. An analytical argument, of geometrical nature, confirms this conclusion and gives a theoretical upper bound on the additional biological effectiveness of the decay. However, no explanation can be offered at present for the observed difference in the biological effectiveness between (9)C and (12)C; the reproducibility of this surprising result will be verified in coming experiments.

TIME STRUCTURE OF GAMMA-RAY SIGNALS GENERATED IN LINE-OF-SIGHT INTERACTIONS OF COSMIC RAYS FROM DISTANT BLAZARS

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

Prosekin, Anton; Aharonian, Felix; Essey, Warren

2012-10-01

Blazars are expected to produce both gamma rays and cosmic rays. Therefore, observed high-energy gamma rays from distant blazars may contain a significant contribution from secondary gamma rays produced along the line of sight by the interactions of cosmic-ray protons with background photons. Unlike the standard models of blazars that consider only the primary photons emitted at the source, models that include the cosmic-ray contribution predict that even {approx}10 TeV photons should be detectable from distant objects with redshifts as high as z {>=} 0.1. Secondary photons contribute to signals of point sources only if the intergalactic magnetic fields aremore » very small, B {approx}< 10{sup -14} G, and their detection can be used to set upper bounds on magnetic fields along the line of sight. Secondary gamma rays have distinct spectral and temporal features. We explore the temporal properties of such signals using a semi-analytical formalism and detailed numerical simulations, which account for all the relevant processes, including magnetic deflections. In particular, we elucidate the interplay of time delays coming from the proton deflections and from the electromagnetic cascade, and we find that, at multi-TeV energies, secondary gamma rays can show variability on timescales of years for B {approx} 10{sup -15} G.« less

Reduced Plasminogen Binding and Delayed Activation Render γ′-Fibrin More Resistant to Lysis than γA-Fibrin*

PubMed Central

Kim, Paul Y.; Vu, Trang T.; Leslie, Beverly A.; Stafford, Alan R.; Fredenburgh, James C.; Weitz, Jeffrey I.

2014-01-01

Fibrin (Fn) clots formed from γ′-fibrinogen (γ′-Fg), a variant with an elongated γ-chain, are resistant to lysis when compared with clots formed from the predominant γA-Fg, a finding previously attributed to differences in clot structure due to delayed thrombin-mediated fibrinopeptide (FP) B release or impaired cross-linking by factor XIIIa. We investigated whether slower lysis of γ′-Fn reflects delayed plasminogen (Pg) binding and/or activation by tissue plasminogen activator (tPA), reduced plasmin-mediated proteolysis of γ′-Fn, and/or altered cross-linking. Clots formed from γ′-Fg lysed more slowly than those formed from γA-Fg when lysis was initiated with tPA/Pg when FPA and FPB were both released, but not when lysis was initiated with plasmin, or when only FPA was released. Pg bound to γ′-Fn with an association rate constant 22% lower than that to γA-Fn, and the lag time for initiation of Pg activation by tPA was longer with γ′-Fn than with γA-Fn. Once initiated, however, Pg activation kinetics were similar. Factor XIIIa had similar effects on clots formed from both Fg isoforms. Therefore, slower lysis of γ′-Fn clots reflects delayed FPB release, which results in delayed binding and activation of Pg. When clots were formed from Fg mixtures containing more than 20% γ′-Fg, the upper limit of the normal level, the delay in lysis was magnified. These data suggest that circulating levels of γ′-Fg modulate the susceptibility of clots to lysis by slowing Pg activation by tPA and provide another example of the intimate connections between coagulation and fibrinolysis. PMID:25128532

Single generation cycles and delayed feedback cycles are not separate phenomena.

PubMed

Pfaff, T; Brechtel, A; Drossel, B; Guill, C

2014-12-01

We study a simple model for generation cycles, which are oscillations with a period of one or a few generation times of the species. The model is formulated in terms of a single delay-differential equation for the population density of an adult stage, with recruitment to the adult stage depending on the intensity of competition during the juvenile phase. This model is a simplified version of a group of models proposed by Gurney and Nisbet, who were the first to distinguish between single-generation cycles and delayed-feedback cycles. According to these authors, the two oscillation types are caused by different mechanisms and have periods in different intervals, which are one to two generation times for single-generation cycles and two to four generation times for delayed-feedback cycles. By abolishing the strict coupling between the maturation time and the time delay between competition and its effect on the population dynamics, we find that single-generation cycles and delayed-feedback cycles occur in the same model version, with a gradual transition between the two as the model parameters are varied over a sufficiently large range. Furthermore, cycle periods are not bounded to lie within single octaves. This implies that a clear distinction between different types of generation cycles is not possible. Cycles of all periods and even chaos can be generated by varying the parameters that determine the time during which individuals from different cohorts compete with each other. This suggests that life-cycle features in the juvenile stage and during the transition to the adult stage are important determinants of the dynamics of density limited populations. Copyright © 2014 Elsevier Inc. All rights reserved.

Kinetic studies of a doubly bound red cell antigen-antibody system.

PubMed

Oberhardt, B J; Miller, I F

1972-08-01

The Polybrene method for detection of red cell antibodies which utilizes continuous flow equipment was modified so that kinetic studies could be performed on red cell antibodies doubly bound between adjacent red cells. In the anti-Rh(o)-Rh(o) erythrocyte system, deaggregation by temperature was studied over an antibody concentration range of from approximately 1 to 500 antibody molecules per erythrocyte, a residence time range of approximately eightfold, and a temperature range of from 10 to 55 degrees C. The rate of dissociation of antigen-antibody complex, as determined from deaggregation of antibody-dependent red cell aggregates, was found to be of apparent zero order. The apparent activation energy for the antigen-antibody reaction under the experimental conditions was determined and found to be higher than would be expected for singly bound antigen-antibody systems. Possible explanations are considered for these findings in terms of an antigen-antibody bond-breaking model.

Open Systems with Error Bounds: Spin-Boson Model with Spectral Density Variations.

PubMed

Mascherpa, F; Smirne, A; Huelga, S F; Plenio, M B

2017-03-10

In the study of open quantum systems, one of the most common ways to describe environmental effects on the reduced dynamics is through the spectral density. However, in many models this object cannot be computed from first principles and needs to be inferred on phenomenological grounds or fitted to experimental data. Consequently, some uncertainty regarding its form and parameters is unavoidable; this in turn calls into question the accuracy of any theoretical predictions based on a given spectral density. Here, we focus on the spin-boson model as a prototypical open quantum system, find two error bounds on predicted expectation values in terms of the spectral density variation considered, and state a sufficient condition for the strongest one to apply. We further demonstrate an application of our result, by bounding the error brought about by the approximations involved in the hierarchical equations of motion resolution method for spin-boson dynamics.

Systematics of intermediate-energy single-nucleon removal cross sections

NASA Astrophysics Data System (ADS)

Tostevin, J. A.; Gade, A.

2014-11-01

There is now a large and increasing body of experimental data and theoretical analyses for reactions that remove a single nucleon from an intermediate-energy beam of neutron- or proton-rich nuclei. In each such measurement, one obtains the inclusive cross section for the population of all bound final states of the mass A -1 reaction residue. These data, from different regions of the nuclear chart, and that involve weakly and strongly bound nucleons, are compared with theoretical expectations. These calculations include an approximate treatment of the reaction dynamics and shell-model descriptions of the projectile initial state, the bound final states of the residues, and the single-particle strengths computed from their overlap functions. The results are discussed in the light of recent data, more exclusive tests of the eikonal dynamical description, and calculations that take input from more microscopic nuclear structure models.

IMPROVING THE QUALITY, AVAILABILITY AND SUSTAINABILITY OF DRINKING WATER SUPPLIES THROUGH ANTIFOULING AND ANTISCALING DESALINATION MEMBRANES

EPA Science Inventory

Surface modification with the selected polymers is expected to reduce the fouling and scaling propensity of desalination membranes by strongly binding water at the membrane surface. Foulants will interact with this bound water layer and not with the membrane surface itself....

Quartified leptonic color, bound states, and future electron–positron collider

DOE PAGES

Kownacki, Corey; Ma, Ernest; Pollard, Nicholas; ...

2017-04-04

The [SU(3)] 4 quartification model of Babu, Ma, and Willenbrock (BMW), proposed in 2003, predicts a confining leptonic color SU(2)gauge symmetry, which becomes strong at the keV scale. Also, it predicts the existence of three families of half-charged leptons (hemions) below the TeV scale. These hemions are confined to form bound states which are not so easy to discover at the Large Hadron Collider (LHC). But, just as J/ψand Υ appeared as sharp resonances in e -e +colliders of the 20th century, the corresponding ‘hemionium’ states are expected at a future e -e +collider of the 21st century.

Effects of the Carrier-Envelope Phase in the Multiphoton Ionization Regime

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

Nakajima, Takashi; Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581; Watanabe, Shuntaro

2006-06-02

We theoretically investigate the effects of the carrier-envelope phase of few-cycle laser pulses in the multiphoton ionization regime. For atoms with low ionization potential, total ionization yield barely exhibits phase dependence, as expected. However, population of some bound states clearly shows phase dependence. This implies that the measurement of the carrier-envelope phase would be possible through the photoemission between bound states without energy-and-angle-resolved photoelectron detection. The considered scheme could be particularly useful to measure the carrier-envelope phase for a light source without an amplifier, such as a laser oscillator, which cannot provide sufficient pulse energy to induce tunneling ionization.

[Characteristics of growth and development in children from families at social risk].

PubMed

Stojadinović, A

2001-01-01

Body height and weight are important indicators of children's health status. There are many evidences that children from disadvantaged families have lower height and weight than children of the same age from families without social risk. The aim of this study was to investigate characteristics of growth and development of children from economically disadvantaged families. The study was partly retrospective and partly prospective. The retrospective study included 509 children from disadvantaged families hospitalized at the Institute of Child and Adolescent Health Care in Novi Sad, during a five-year period. The prospective study included 90 children from disadvantaged families (experimental group) and 132 children from families without social risk (control group) hospitalized at the Institute during a six month period. Height/length, weight, head circumference, and psychomotor/intellectual development have been examined. In the retrospective study results were compared with theoretically expected values, whereas the prospective study results of experimental and control group were compared. In the retrospective study that included only children from disadvantaged families, 136 (26.7%) children had height/length, 173 (34%) had weight, and 86 (16.9%) children had head circumference below 10th percentile. Delay in psychomotor/intellectual development was established in 177 (34.8%) children. Children from families with social risk have significantly more often height/length, weight, head circumference and developmental delay than theoretically expected. In the prospective study 40 (44.4%) children from experimental group had height/length, 29 (32.2%) had weight, 20 (22.2%) children had head circumference below 10th percentile, and 17 (26.2%) had delay in psychomotor/intellectual development. Children from disadvantaged families (experimental group) significantly more often had delay in growth and development comparing with children from families without social risk (control group). Children from disadvantaged families significantly more often exhibit delay in growth and development, comparing with children of the same age from families without social risk. Therefore, pediatricians should consider social risk factors whenever treating children with growth or developmental delay.

Slow-onset myocardial infarction and its influence on help-seeking behaviors.

PubMed

O'Donnell, Sharon; Moser, Debra K

2012-01-01

Patient decision delay continues to be a major factor of delay along the pathway of care for patients with myocardial infarction (MI). Although potentially modifiable, efforts to reduce these delays through educational and media interventions have been relatively unsuccessful. This failure has been due, in part, to the lack of understanding about the complex sociopsychological and clinical dimensions associated with the phenomenon of help-seeking behavior. The aims of this study were to (1) perform an in-depth analysis of patients' MI symptom experiences and (2) describe their help-seeking behavior in response to these symptom experiences. In-depth interviews were used to examine the symptom experiences and help-seeking behavior of men and women with MI. Participants (n = 42) were interviewed 2 to 4 days after their admission to 1 of 2 hospitals in Dublin, Ireland. Two new discrete MI categories emerged from the findings-slow-onset MI and fast-onset MI. Slow-onset MI is characterized by the gradual onset of mild symptoms, whereas fast-onset MI describes the sudden onset of severe chest pain. Most participants (n = 27) experienced slow-onset MI but expected the symptom presentation associated with fast-onset MI. The mismatch of expected and experienced symptoms for participants with slow-onset MI led to the mislabeling of symptoms to a noncardiac cause and protracted help-seeking delays. Participants with fast-onset MI (n = 15) quickly attributed their symptoms to a cardiac cause, which expedited appropriate help-seeking behaviors. Definitions of MI and the educational information provided to the public need to be reviewed. Slow-onset MI and fast-onset MI provide plausible definition alternatives and, possibly, a more authentic version of real MI events than what is currently used. They also provide a unique "delay" perspective, which may inform future educational initiatives targeted at decision delay reduction.

IR signature of the photoionization-induced hydrophobic-->hydrophilic site switching in phenol-Arn clusters

NASA Astrophysics Data System (ADS)

Ishiuchi, Shun-ichi; Sakai, Makoto; Tsuchida, Yuji; Takeda, Akihiro; Kawashima, Yasutake; Dopfer, Otto; Müller-Dethlefs, Klaus; Fujii, Masaaki

2007-09-01

IR spectra of phenol-Arn (PhOH-Arn) clusters with n =1 and 2 were measured in the neutral and cationic electronic ground states in order to determine the preferential intermolecular ligand binding motifs, hydrogen bonding (hydrophilic interaction) versus π bonding (hydrophobic interaction). Analysis of the vibrational frequencies of the OH stretching motion, νOH, observed in nanosecond IR spectra demonstrates that neutral PhOH-Ar and PhOH -Ar2 as well as cationic PhOH +-Ar have a π-bound structure, in which the Ar atoms bind to the aromatic ring. In contrast, the PhOH +-Ar2 cluster cation is concluded to have a H-bound structure, in which one Ar atom is hydrogen-bonded to the OH group. This π →H binding site switching induced by ionization was directly monitored in real time by picosecond time-resolved IR spectroscopy. The π-bound νOH band is observed just after the ionization and disappears simultaneously with the appearance of the H-bound νOH band. The analysis of the picosecond IR spectra demonstrates that (i) the π →H site switching is an elementary reaction with a time constant of ˜7ps, which is roughly independent of the available internal vibrational energy, (ii) the barrier for the isomerization reaction is rather low(<100cm-1), (iii) both the position and the width of the H-bound νOH band change with the delay time, and the time evolution of these spectral changes can be rationalized by intracluster vibrational energy redistribution occurring after the site switching. The observation of the ionization-induced switch from π bonding to H bonding in the PhOH +-Ar2 cation corresponds to the first manifestation of an intermolecular isomerization reaction in a charged aggregate.

Structured Uncertainty Bound Determination From Data for Control and Performance Validation

NASA Technical Reports Server (NTRS)

Lim, Kyong B.

2003-01-01

This report attempts to document the broad scope of issues that must be satisfactorily resolved before one can expect to methodically obtain, with a reasonable confidence, a near-optimal robust closed loop performance in physical applications. These include elements of signal processing, noise identification, system identification, model validation, and uncertainty modeling. Based on a recently developed methodology involving a parameterization of all model validating uncertainty sets for a given linear fractional transformation (LFT) structure and noise allowance, a new software, Uncertainty Bound Identification (UBID) toolbox, which conveniently executes model validation tests and determine uncertainty bounds from data, has been designed and is currently available. This toolbox also serves to benchmark the current state-of-the-art in uncertainty bound determination and in turn facilitate benchmarking of robust control technology. To help clarify the methodology and use of the new software, two tutorial examples are provided. The first involves the uncertainty characterization of a flexible structure dynamics, and the second example involves a closed loop performance validation of a ducted fan based on an uncertainty bound from data. These examples, along with other simulation and experimental results, also help describe the many factors and assumptions that determine the degree of success in applying robust control theory to practical problems.

Role of working memory in transformation of visual and motor representations for use in mental simulation.

PubMed

Gabbard, Carl; Lee, Jihye; Caçola, Priscila

2013-01-01

This study examined the role of visual working memory when transforming visual representations to motor representations in the context of motor imagery. Participants viewed randomized number sequences of three, four, and five digits, and then reproduced the sequence by finger tapping using motor imagery or actually executing the movements; movement duration was recorded. One group viewed the stimulus for three seconds and responded immediately, while the second group had a three-second view followed by a three-second blank screen delay before responding. As expected, delay group times were longer with each condition and digit load. Whereas correlations between imagined and executed actions (temporal congruency) were significant in a positive direction for both groups, interestingly, the delay group's values were significantly stronger. That outcome prompts speculation that delay influenced the congruency between motor representation and actual execution.

Risk attitude in small timesaving decisions.

PubMed

Munichor, Nira; Erev, Ido; Lotem, Arnon

2006-09-01

Four experiments are presented that explore situations in which a decision maker has to rely on personal experience in an attempt to minimize delays. Experiment 1 shows that risk-attitude in these timesaving decisions is similar to risk-attitude in money-related decisions from experience: A risky prospect is more attractive than a safer prospect with the same expected value only when it leads to a better outcome most of the time. Experiment 2 highlights a boundary condition: It suggests that a difficulty in ranking the relevant delays moves behavior toward random choice. Experiments 3 and 4 show that when actions must be taken during the delay (thereby helping compare delays), this increases the similarity of timesaving decisions to money-related decisions. In these settings the results reflect an increase in risk aversion with experience. The relationship of the results to the study of non-human time-related decisions, human money-related decisions and human time perception is discussed.

The Hubble Constant from SN Refsdal

NASA Astrophysics Data System (ADS)

Vega-Ferrero, J.; Diego, J. M.; Miranda, V.; Bernstein, G. M.

2018-02-01

Hubble Space Telescope observations from 2015 December 11 detected the expected fifth counter-image of supernova (SN) Refsdal at z = 1.49. In this Letter, we compare the time-delay predictions from numerous models with the measured value derived by Kelly et al. from very early data in the light curve of the SN Refsdal and find a best value for {H}0={64}-11+9 {km} {{{s}}}-1 {{Mpc}}-1 (68% CL), in excellent agreement with predictions from cosmic microwave background and recent weak lensing data + baryon acoustic oscillations + Big Bang nucleosynthesis (from the DES Collaboration). This is the first constraint on H 0 derived from time delays between multiple-lensed SN images, and the first with a galaxy cluster lens, subject to systematic effects different from other time-delay H 0 estimates. Additional time-delay measurements from new multiply imaged SNe will allow derivation of competitive constraints on H 0.

Risk-Taking and the Feedback Negativity Response to Loss among At-Risk Adolescents

PubMed Central

Crowley, Michael J.; Wu, Jia; Crutcher, Clifford; Bailey, Christopher A.; Lejuez, C.W.; Mayes, Linda C.

2009-01-01

Event-related brain potentials were examined in 32 adolescents (50% female) from a high-risk sample, who were exposed to cocaine and other drugs prenatally. Adolescents were selected for extreme high- or low-risk behavior on the Balloon Analog Risk Task, a measure of real-world risk-taking propensity. The feedback error-related negativity (fERN), an event-related potential (ERP) that occurs when an expected reward does not occur, was examined in a game in which choices lead to monetary gains and losses with feedback delayed 1 or 2 s. The fERN was clearly visible in the fronto-central scalp region in this adolescent sample. Feedback type, feedback delay, risk status, and sex were all associated with fERN variability. Monetary feedback also elicited a P300-like component, moderated by delay and sex. Delaying reward feedback may provide a means for studying complementary functioning of dopamine and norepinephrine systems. PMID:19372694

Positive mood effects on delay discounting.

PubMed

Hirsh, Jacob B; Guindon, Alex; Morisano, Dominique; Peterson, Jordan B

2010-10-01

Delay discounting is the process by which the value of an expected reward decreases as the delay to obtaining that reward increases. Individuals with higher discounting rates tend to prefer smaller immediate rewards over larger delayed rewards. Previous research has indicated that personality can influence an individual's discounting rates, with higher levels of Extraversion predicting a preference for immediate gratification. The current study examined how this relationship would be influenced by situational mood inductions. While main effects were observed for both Extraversion and cognitive ability in the prediction of discounting rates, a significant interaction was also observed between Extraversion and positive affect. Extraverted individuals were more likely to prefer an immediate reward when first put in a positive mood. Extraverts thus appear particularly sensitive to impulsive, incentive-reward-driven behavior by temperament and by situational factors heightening positive affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved).

Antigen localization controls T cell-mediated tumor immunity.

PubMed

Zeelenberg, Ingrid S; van Maren, Wendy W C; Boissonnas, Alexandre; Van Hout-Kuijer, Maaike A; Den Brok, Martijn H M G M; Wagenaars, Jori A L; van der Schaaf, Alie; Jansen, Eric J R; Amigorena, Sebastian; Théry, Clotilde; Figdor, Carl G; Adema, Gosse J

2011-08-01

Effective antitumor immunotherapy requires the identification of suitable target Ags. Interestingly, many of the tumor Ags used in clinical trials are present in preparations of secreted tumor vesicles (exosomes). In this study, we compared T cell responses elicited by murine MCA101 fibrosarcoma tumors expressing a model Ag at different localizations within the tumor cell in association with secreted vesicles (exosomes), as a nonsecreted cell-associated protein, or as secreted soluble protein. Remarkably, we demonstrated that only the tumor-secreting vesicle-bound Ag elicited a strong Ag-specific CD8(+) T cell response, CD4(+) T cell help, Ag-specific Abs, and a decrease in the percentage of immunosuppressive regulatory T cells in the tumor. Moreover, in a therapeutic tumor model of cryoablation, only in tumors secreting vesicle-bound Ag could Ag-specific CD8(+) T cells still be detected up to 16 d after therapy. We concluded that the localization of an Ag within the tumor codetermines whether a robust immunostimulatory response is elicited. In vivo, vesicle-bound Ag clearly skews toward a more immunogenic phenotype, whereas soluble or cell-associated Ag expression cannot prevent or even delay outgrowth and results in tumor tolerance. This may explain why particular immunotherapies based on these vesicle-bound tumor Ags are potentially successful. Therefore, we conclude that this study may have significant implications in the discovery of new tumor Ags suitable for immunotherapy and that their location should be taken into account to ensure a strong antitumor immune response.

β -delayed γ decay of P 26 : Possible evidence of a proton halo

DOE PAGES

Pérez-Loureiro, D.; Wrede, C.; Bennett, M. B.; ...

2016-06-01

Background: Measurements of β decay provide important nuclear structure information that can be used to probe isospin asymmetries and inform nuclear astrophysics studies. Purpose: To measure the β-delayed γ decay of 26P and compare the results with previous experimental results and shell-model calculations. Method: A 26P fast beam produced using nuclear fragmentation was implanted into a planar germanium detector. Its β-delayed γ-ray emission was measured with an array of 16 high-purity germanium detectors. Positrons emitted in the decay were detected in coincidence to reduce the background. Results: The absolute intensities of 26P β-delayed γ-rays were determined. A total of sixmore » new β-decay branches and 15 new γ-ray lines have been observed for the first time in 26P β-decay. A complete β-decay scheme was built for the allowed transitions to bound excited states of 26Si. ft values and Gamow-Teller strengths were also determined for these transitions and compared with shell model calculations and the mirror β-decay of 26Na, revealing significant mirror asymmetries. Conclusions: A very good agreement with theoretical predictions based on the USDB shell model is observed. The significant mirror asymmetry observed for the transition to the first excited state (δ=51(10)%) may be evidence for a proton halo in 26P.« less

Enuresis: An Historical, Cultural, and Contemporary Account of Etiology and Treatment

ERIC Educational Resources Information Center

McDonald, James E.; Trepper, Terry

1977-01-01

The authors discuss the cultural relativism of enuresis and the subsequent notion that urinary incontinence may not be a disease or psychopathy, but, rather, a problem associated with social expectations and developmental delays. (Author)

Improving the accuracy of camber predictions for precast pretensioned concrete beams : [tech transfer summary].

DOT National Transportation Integrated Search

2015-07-01

Implementing the recommendations of this study is expected to significantly : improve the accuracy of camber measurements and predictions and to : ultimately help reduce construction delays, improve bridge serviceability, : and decrease costs.

Components of visual search in childhood-onset schizophrenia and attention-deficit/hyperactivity disorder.

PubMed

Karatekin, C; Asarnow, R F

1998-10-01

This study tested the hypotheses that visual search impairments in schizophrenia are due to a delay in initiation of search or a slow rate of serial search. We determined the specificity of these impairments by comparing children with schizophrenia to children with attention-deficit hyperactivity disorder (ADHD) and age-matched normal children. The hypotheses were tested within the framework of feature integration theory by administering children tasks tapping parallel and serial search. Search rate was estimated from the slope of the search functions, and duration of the initial stages of search from time to make the first saccade on each trial. As expected, manual response times were elevated in both clinical groups. Contrary to expectation, ADHD, but not schizophrenic, children were delayed in initiation of serial search. Finally, both groups showed a clear dissociation between intact parallel search rates and slowed serial search rates.

Frequency-domain coherent multidimensional spectroscopy when dephasing rivals pulsewidth: Disentangling material and instrument response

DOE PAGES

Kohler, Daniel D.; Thompson, Blaise J.; Wright, John C.

2017-08-31

Ultrafast spectroscopy is often collected in the mixed frequency/time domain, where pulse durations are similar to system dephasing times. In these experiments, expectations derived from the familiar driven and impulsive limits are not valid. This work simulates the mixed-domain four-wave mixing response of a model system to develop expectations for this more complex field-matter interaction. We also explore frequency and delay axes. We show that these line shapes are exquisitely sensitive to excitation pulse widths and delays. Near pulse overlap, the excitation pulses induce correlations that resemble signatures of dynamic inhomogeneity. We describe these line shapes using an intuitive picturemore » that connects to familiar field-matter expressions. We develop strategies for distinguishing pulse-induced correlations from true system inhomogeneity. Our simulations provide a foundation for interpretation of ultrafast experiments in the mixed domain.« less

Sentinel lymph node biopsy before mastectomy and immediate breast reconstruction may predict post-mastectomy radiotherapy, reduce delayed complications and improve the choice of reconstruction.

PubMed

Mannu, G S; Navi, A; Morgan, A; Mirza, S M; Down, S K; Farooq, N; Burger, A; Hussien, M I

2012-01-01

Adjuvant post-mastectomy radiotherapy (RT), which is often unpredicted, is known to increase complications following immediate breast reconstruction (IBR). To investigate the role of sentinel lymph node biopsy (SLN) in predicting RT and improving the choice of IBR. All patients who had mastectomy and IBR between January 2004 and January 2007 were reviewed retrospectively. Axillary staging (clearance or SLN) was performed at the same time until October 2005 (Group 1), when the Unit's protocol was updated to perform SLN initially prior to mastectomy and IBR (Group 2). Patients in Group 2 with positive SLN were offered either a delayed reconstruction or a temporary subpectoral immediate tissue expander, while all options were offered if SLN was negative and in Group 1 patients. One hundred and thirty-nine patients were reviewed. 20 patients received unexpected RT in Group 1 (14 tissue expander, 4 Latissimus Dorsi flap with an implant and 2 DIEP flaps) compared to 11 patients in Group 2 who had a temporary tissue expander due to expected RT (P=0.03). Unexpected RT caused delayed complications in 14 patients (70%) compared to no delayed complications in patients who received expected RT in Group 2. SLN biopsy before IBR helps to predict RT and avoids its complications on breast reconstruction. Patients with positive SLN biopsy are best offered a temporary subpectoral tissue expander for IBR. Copyright © 2012 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking.

PubMed

Allan, David S; Scrivens, Nicholas; Lawless, Tiffany; Mostert, Karen; Oppenheimer, Lawrence; Walker, Mark; Petraszko, Tanya; Elmoazzen, Heidi

2016-03-01

Public banking of umbilical cord blood units (CBUs) containing higher numbers of cells ensures timely engraftment after transplantation for increasing numbers of patients. Delayed clamping of the umbilical cord after birth may benefit some infants by preventing iron deficiency. Implications of delayed cord clamping for public cord blood banking remains unclear. CBUs collected by Canadian Blood Services at one collection site between November 1, 2014, and March 17, 2015, were analyzed. The delay in cord clamping after birth was timed and classified as "no delay," 20 to 60 seconds, more than 60 seconds, or more than 120 seconds. Of 367 collections, 100 reported no delay in clamping while clamping was delayed by 20 to 60 seconds (n = 69), more than 60 seconds (n = 98), or more than 120 seconds (n = 100) in the remaining cases. The mean volume and total nucleated cells (TNCs) in units with no delay in clamping were significantly greater than mean volumes for all categories of delayed clamping (Tukey's test, p < 0.05 for each comparison). The proportion of units with more than 1.5 × 10(9) TNCs was significantly reduced when clamping was delayed (p = 5.5 × 10(-8) ). The difference was most marked for cords that were clamped more than 120 seconds after delivery (6.2% compared with 39%). Delayed cord clamping greatly diminishes the volume and TNC count of units collected for a public cord blood bank. Creating an inventory of CBUs with high TNC content may take more time than expected. © 2015 AABB.

Decentralized adaptive neural control for high-order interconnected stochastic nonlinear time-delay systems with unknown system dynamics.

PubMed

Si, Wenjie; Dong, Xunde; Yang, Feifei

2018-03-01

This paper is concerned with the problem of decentralized adaptive backstepping state-feedback control for uncertain high-order large-scale stochastic nonlinear time-delay systems. For the control design of high-order large-scale nonlinear systems, only one adaptive parameter is constructed to overcome the over-parameterization, and neural networks are employed to cope with the difficulties raised by completely unknown system dynamics and stochastic disturbances. And then, the appropriate Lyapunov-Krasovskii functional and the property of hyperbolic tangent functions are used to deal with the unknown unmatched time-delay interactions of high-order large-scale systems for the first time. At last, on the basis of Lyapunov stability theory, the decentralized adaptive neural controller was developed, and it decreases the number of learning parameters. The actual controller can be designed so as to ensure that all the signals in the closed-loop system are semi-globally uniformly ultimately bounded (SGUUB) and the tracking error converges in the small neighborhood of zero. The simulation example is used to further show the validity of the design method. Copyright © 2018 Elsevier Ltd. All rights reserved.

Texture analysis of common renal masses in multiple MR sequences for prediction of pathology

NASA Astrophysics Data System (ADS)

Hoang, Uyen N.; Malayeri, Ashkan A.; Lay, Nathan S.; Summers, Ronald M.; Yao, Jianhua

2017-03-01

This pilot study performs texture analysis on multiple magnetic resonance (MR) images of common renal masses for differentiation of renal cell carcinoma (RCC). Bounding boxes are drawn around each mass on one axial slice in T1 delayed sequence to use for feature extraction and classification. All sequences (T1 delayed, venous, arterial, pre-contrast phases, T2, and T2 fat saturated sequences) are co-registered and texture features are extracted from each sequence simultaneously. Random forest is used to construct models to classify lesions on 96 normal regions, 87 clear cell RCCs, 8 papillary RCCs, and 21 renal oncocytomas; ground truths are verified through pathology reports. The highest performance is seen in random forest model when data from all sequences are used in conjunction, achieving an overall classification accuracy of 83.7%. When using data from one single sequence, the overall accuracies achieved for T1 delayed, venous, arterial, and pre-contrast phase, T2, and T2 fat saturated were 79.1%, 70.5%, 56.2%, 61.0%, 60.0%, and 44.8%, respectively. This demonstrates promising results of utilizing intensity information from multiple MR sequences for accurate classification of renal masses.

Fast and secure handover of intra-ASN IEEE802.16 network by proposed certificate based pre-authentication

NASA Astrophysics Data System (ADS)

Sridevi, B.; Supriya, T. S.; Rajaram, S.

2013-01-01

The current generation of wireless networks has been designed predominantly to support voice and more recently data traffic. WiMAX is currently one of the hottest technologies in wireless. The main motive of the mobile technologies is to provide seamless cost effective mobility. But this is affected by Authentication cost and handover delay since on each handoff the Mobile Station (MS) has to undergo all steps of authentication. Pre-Authentication is used to reduce the handover delay and increase the speed of the Intra-ASN Handover. Proposed Pre-Authentication method is intended to reduce the authentication delay by getting pre authenticated by central authority called Pre Authentication Authority (PAA). MS requests PAA for Pre Authentication Certificate (PAC) before performing handoff. PAA verifies the identity of MS and provides PAC to MS and also to the neighboring target Base Stations (tBSs). MS having time bound PAC can skip the authentication process when recognized by target BS during handoff. It also prevents the DOS (Denial Of Service) attack and Replay attack. It has no wastage of unnecessary key exchange of the resources. The proposed work is simulated by NS2 model and by MATLAB.

Comparison of an extended-release formulation of granisetron (APF530) versus palonosetron for the prevention of chemotherapy-induced nausea and vomiting associated with moderately or highly emetogenic chemotherapy: results of a prospective, randomized, double-blind, noninferiority phase 3 trial.

PubMed

Raftopoulos, Harry; Cooper, William; O'Boyle, Erin; Gabrail, Nashat; Boccia, Ralph; Gralla, Richard J

2015-03-01

Subcutaneous APF530 provides controlled sustained release of granisetron to prevent acute (0-24 h) and delayed (24-120 h) chemotherapy-induced nausea and vomiting (CINV). This randomized, double-blind phase 3 trial compared APF530 and palonosetron in preventing acute and delayed CINV after moderately (MEC) or highly emetogenic chemotherapy (HEC). Patients receiving single-day MEC or HEC received single-dose APF530 250 or 500 mg subcutaneously (SC) (granisetron 5 or 10 mg) or intravenous palonosetron 0.25 mg. Primary objectives were to establish APF530 noninferiority to palonosetron for preventing acute CINV following MEC or HEC and delayed CINV following MEC and to determine APF530 superiority to palonosetron for preventing delayed CINV following HEC. The primary efficacy end point was complete response (CR [using CI difference for APF530-palonosetron]). A lower confidence bound greater than -15 % indicated noninferiority. In the modified intent-to-treat population (MEC = 634; HEC = 707), both APF530 doses were noninferior to palonosetron in preventing acute CINV after MEC (CRs 74.8 % [-9.8, 9.3] and 76.9 % [-7.5, 11.4], respectively, vs. 75.0 % palonosetron) and after HEC (CRs 77.7 % [-11.5, 5.5] and 81.3 % [-7.7, 8.7], respectively, vs. 80.7 % palonosetron). APF530 500 mg was noninferior to palonosetron in preventing delayed CINV after MEC (CR 58.5 % [-9.5, 12.1] vs. 57.2 % palonosetron) but not superior in preventing delayed CINV after HEC. Adverse events were generally mild and unrelated to treatment, the most common (excluding injection-site reactions) being constipation. A single subcutaneous APF530 injection offers a convenient alternative to palonosetron for preventing acute and delayed CINV after MEC or HEC.

Network coding based joint signaling and dynamic bandwidth allocation scheme for inter optical network unit communication in passive optical networks

NASA Astrophysics Data System (ADS)

Wei, Pei; Gu, Rentao; Ji, Yuefeng

2014-06-01

As an innovative and promising technology, network coding has been introduced to passive optical networks (PON) in recent years to support inter optical network unit (ONU) communication, yet the signaling process and dynamic bandwidth allocation (DBA) in PON with network coding (NC-PON) still need further study. Thus, we propose a joint signaling and DBA scheme for efficiently supporting differentiated services of inter ONU communication in NC-PON. In the proposed joint scheme, the signaling process lays the foundation to fulfill network coding in PON, and it can not only avoid the potential threat to downstream security in previous schemes but also be suitable for the proposed hybrid dynamic bandwidth allocation (HDBA) scheme. In HDBA, a DBA cycle is divided into two sub-cycles for applying different coding, scheduling and bandwidth allocation strategies to differentiated classes of services. Besides, as network traffic load varies, the entire upstream transmission window for all REPORT messages slides accordingly, leaving the transmission time of one or two sub-cycles to overlap with the bandwidth allocation calculation time at the optical line terminal (the OLT), so that the upstream idle time can be efficiently eliminated. Performance evaluation results validate that compared with the existing two DBA algorithms deployed in NC-PON, HDBA demonstrates the best quality of service (QoS) support in terms of delay for all classes of services, especially guarantees the end-to-end delay bound of high class services. Specifically, HDBA can eliminate queuing delay and scheduling delay of high class services, reduce those of lower class services by at least 20%, and reduce the average end-to-end delay of all services over 50%. Moreover, HDBA also achieves the maximum delay fairness between coded and uncoded lower class services, and medium delay fairness for high class services.

Beyond pragmatics: morphosyntactic development in autism.

PubMed

Eigsti, Inge-Marie; Bennetto, Loisa; Dadlani, Mamta B

2007-07-01

Language acquisition research in autism has traditionally focused on high-level pragmatic deficits. Few studies have examined grammatical abilities in autism, with mixed findings. The present study addresses this gap in the literature by providing a detailed investigation of syntactic and higher-level discourse abilities in verbal children with autism, age 5 years. Findings indicate clear language difficulties that go beyond what would be expected based on developmental level; specifically, syntactic delays, impairments in discourse management and increased production of non-meaningful words (jargon). The present study indicates a highly specific pattern of language impairments, and importantly, syntactic delays, in a group of children with autism carefully matched on lexical level and non-verbal mental age with children with developmental delays and typical development.

Detection of special nuclear material by observation of delayed neutrons with a novel fast neutron composite detector

NASA Astrophysics Data System (ADS)

Mayer, Michael; Nattress, Jason; Barhoumi Meddeb, Amira; Foster, Albert; Trivelpiece, Cory; Rose, Paul; Erickson, Anna; Ounaies, Zoubeida; Jovanovic, Igor

2015-10-01

Detection of shielded special nuclear material is crucial to countering nuclear terrorism and proliferation, but its detection is challenging. By observing the emission of delayed neutrons, which is a unique signature of nuclear fission, the presence of nuclear material can be inferred. We report on the observation of delayed neutrons from natural uranium by using monoenergetic photons and neutrons to induce fission. An interrogating beam of 4.4 MeV and 15.1 MeV gamma-rays and neutrons was produced using the 11B(d,n-γ)12C reaction and used to probe different targets. Neutron detectors with complementary Cherenkov detectors then discriminate material undergoing fission. A Li-doped glass-polymer composite neutron detector was used, which displays excellent n/ γ discrimination even at low energies, to observe delayed neutrons from uranium fission. Delayed neutrons have relatively low energies (~0.5 MeV) compared to prompt neutrons, which makes them difficult to detect using recoil-based detectors. Neutrons were counted and timed after the beam was turned off to observe the characteristic decaying time profile of delayed neutrons. The expected decay of neutron emission rate is in agreement with the common parametrization into six delayed neutron groups.

Theoretical and simulated performance for a novel frequency estimation technique

NASA Technical Reports Server (NTRS)

Crozier, Stewart N.

1993-01-01

A low complexity, open-loop, discrete-time, delay-multiply-average (DMA) technique for estimating the frequency offset for digitally modulated MPSK signals is investigated. A nonlinearity is used to remove the MPSK modulation and generate the carrier component to be extracted. Theoretical and simulated performance results are presented and compared to the Cramer-Rao lower bound (CRLB) for the variance of the frequency estimation error. For all signal-to-noise ratios (SNR's) above threshold, it is shown that the CRLB can essentially be achieved with linear complexity.

Timing and adequate attendance of antenatal care visits among women in Ethiopia

PubMed Central

Bishwajit, Ghose; Ekholuenetale, Michael; Shah, Vaibhav; Kadio, Bernard; Udenigwe, Ogochukwu

2017-01-01

Introduction Although ANC services are increasingly available to women in low and middle-income countries, their inadequate use persists. This suggests a misalignment between aims of the services and maternal beliefs and circumstances. Owing to the dearth of studies examining the timing and adequacy of content of care, this current study aims to investigate the timing and frequency of ANC visits in Ethiopia. Methods Data was obtained from the nationally representative 2011 Ethiopian Demographic and Health Survey (EDHS) which used a two-stage cluster sampling design to provide estimates for the health and demographic variables of interest for the country. Our study focused on a sample of 10,896 women with history of at least one childbirth event. Percentages of timing and adequacy of ANC visits were conducted across the levels of selected factors. Variables which were associated at 5% significance level were examined in the multivariable logistic regression model for association between timing and frequency of ANC visits and the explanatory variables while controlling for covariates. Furthermore, we presented the approach to estimate marginal effects involving covariate-adjusted logistic regression with corresponding 95%CI of delayed initiation of ANC visits and inadequate ANC attendance. The method used involved predicted probabilities added up to a weighted average showing the covariate distribution in the population. Results Results indicate that 66.3% of women did not use ANC at first trimester and 22.3% had ANC less than 4 visits. The results of this study were unique in that the association between delayed ANC visits and adequacy of ANC visits were examined using multivariable logistic model and the marginal effects using predicted probabilities. Results revealed that older age interval has higher odds of inadequate ANC visits. More so, type of place of residence was associated with delayed initiation of ANC visits, with rural women having the higher odds of delayed initiation of ANC visits (OR = 1.65; 95%CI: 1.26–2.18). However, rural women had 44% reduction in the odds of having inadequate ANC visits. In addition, multi-parity showed higher odds of delayed initiation of ANC visit when compared to the primigravida (OR = 2.20; 95%CI: 1.07–2.69). On the contrary, there was 36% reduction in the odds of multigravida having inadequate ANC visits when compared to the women who were primigravida. There were higher odds of inadequacy in ANC visits among women who engaged in sales/business, agriculture, skilled manual and other jobs when compared to women who currently do not work, after adjusting for covariates. From the predictive margins, assuming the distribution of all covariates remained the same among respondents, but everyone was aged 15–19 years, we would expect 71.8% delayed initiation of ANC visit. If everyone was aged 20-24years, 73.4%; 25-29years, 66.5%; 30-34years, 64.8%; 35-39years, 65.6%; 40-44years, 59.6% and 45-49years, we would expect 70.1% delayed initiation of ANC visit. If instead the distribution of age was as observed and for other covariates remained the same among respondents, but no respondent lived in the rural, we would expect about 61.4% delayed initiation of ANC visit; if however, everyone lived in the rural, and we would expect 71.6% delayed initiation in ANC visit. Model III revealed the predictive margins of all factors examined for delayed initiation for ANC visits, while Model IV presented the predictive marginal effects of the determinants of adequacy of ANC visits. Conclusion The precise mechanism by which these factors affect ANC visits remain blurred at best. There may be factors on the demand side like the women’s empowerment, financial support of the husband, knowledge of ANC visits in the context of timing, frequency and the expectations of ANC visits might be mediating the effects through the factors found associated in this study. Supply side factors like the quality of ANC services, skilled staff, and geographic location of the health centers also mediate their effects through the highlighted factors. Irrespective of the knowledge about the precise mechanism of action, policy makers could focus on improving women’s empowerment, improving women’s education, reducing wealth inequity and facilitating improved utilization of ANC through modifications on the supply side factors such as geographic location and focus on hard to reach women. PMID:28922383

Timing and delay in children vaccination; evaluation of expanded program of immunization in outskirt of Iranian cities.

PubMed

Rejali, Mehri; Mohammadbeigi, Abolfazl; Mokhtari, Mohsen; Zahraei, Seyed Mohsen; Eshrati, Babak

2015-01-01

Most studies evaluated the vaccine coverage, but the time of vaccination is important as coverage. This study was conducted to evaluate the Expanded Program of Immunization (EPI) in outskirt of Iranian cities regarding to incidence of delay vaccination among children less than 4 years. This cross sectional descriptive study was conducted among children 24-47 months old, living in the suburbs of five metropolises of Iran. Totally, 3610 eligible children selected with proportioned cluster sampling method and data of vaccination card extracted after interview with child parents. Delayed incidence rate reported and predictive factors assessed by Chi square test and Multivariate logistic regression. Overall, 56.6% to 93.2% vaccines were administered out of time. Delayed vaccination incidence with more than one-week delay varies from 5.5% to 74.9% for polio at birth and MMR2 at 18 month, respectively. Mother's educational level and birth order were the most important predictors of delayed vaccination. Incidence of delayed vaccination was enlarged by increasing birth order and decreased in lower educated mothers. Incidence rate of delayed vaccination is more than expectation. Regarding to high coverage vaccines in Iran, heath officers and health policy makers should attempt for on-time vaccination beside of high immunization coverage especially in slum areas with more concentrated immigrants due to low literature and crowded families.

Distortion-product otoacoustic emission reflection-component delays and cochlear tuning: estimates from across the human lifespan.

PubMed

Abdala, Carolina; Guérit, François; Luo, Ping; Shera, Christopher A

2014-04-01

A consistent relationship between reflection-emission delay and cochlear tuning has been demonstrated in a variety of mammalian species, as predicted by filter theory and models of otoacoustic emission (OAE) generation. As a step toward the goal of studying cochlear tuning throughout the human lifespan, this paper exploits the relationship and explores two strategies for estimating delay trends-energy weighting and peak picking-both of which emphasize data at the peaks of the magnitude fine structure. Distortion product otoacoustic emissions (DPOAEs) at 2f1-f2 were recorded, and their reflection components were extracted in 184 subjects ranging in age from prematurely born neonates to elderly adults. DPOAEs were measured from 0.5-4 kHz in all age groups and extended to 8 kHz in young adults. Delay trends were effectively estimated using either energy weighting or peak picking, with the former method yielding slightly shorter delays and the latter somewhat smaller confidence intervals. Delay and tuning estimates from young adults roughly match those obtained from SFOAEs. Although the match is imperfect, reflection-component delays showed the expected bend (apical-basal transition) near 1 kHz, consistent with a break in cochlear scaling. Consistent with other measures of tuning, the term newborn group showed the longest delays and sharpest tuning over much of the frequency range.

Positive parenting mitigates the effects of poor self-regulation on body mass index trajectories from ages 4-15 years.

PubMed

Connell, Lauren E; Francis, Lori A

2014-08-01

This study sought to determine whether parenting style moderates the effects of delay of gratification on body mass index (BMI) trajectories from ages 4-15 years. Longitudinal data were analyzed for 778 children drawn from the Study of Early Child Care and Youth Development. Parenting style (i.e., authoritative, authoritarian, permissive, and neglectful) was created from measures of mothers' sensitivity and expectations for self-control when children were age 4 years. Self-regulation was also measured at 4 years using a well-known delay of gratification protocol. BMI was calculated from measured height and weight at each time point. Mixed modeling was used to test the interaction of parenting styles and ability to delay gratification on BMI trajectories from 4-15 years. There was a significant interaction effect of parenting and ability to delay on BMI growth from 4-15 years for boys. Boys who had authoritarian mothers and failed to delay gratification had a significantly steeper rate of growth in BMI from childhood through adolescence than children in any other parenting by delay group. Authoritative and permissive parenting styles were protective against more rapid BMI gains for boys who could not delay gratification. Ability to delay gratification was protective against BMI gains for boys who had parents with authoritarian or neglectful parenting styles.

Positive parenting mitigates the effects of poor self-regulation on BMI trajectories from age 4 to 15 years

PubMed Central

Connell, Lauren E.; Francis, Lori A.

2014-01-01

Objective This study sought to determine whether parenting style moderated the effects of delay of gratification on BMI trajectories from age 4 to 15 years. Methods Longitudinal data were analyzed on 778 children drawn from the Study of Early Child Care and Youth Development. Parenting style (authoritative, authoritarian, permissive, neglectful) was created from measures of mothers’ sensitivity and expectations for self-control when children were age 4 years. Self-regulation was also measured at 4 years using a well-known delay of gratification protocol. BMI was calculated from measured height and weight at each time point. Mixed modeling was used to test the interaction of parenting styles and ability to delay gratification on BMI trajectories from 4 to 15 years. Results There was a significant interaction effect of parenting and ability to delay on BMI growth from 4 to 15 years for boys. Boys who had authoritarian mothers and failed to delay gratification had a significantly steeper rate of growth in BMI from childhood through adolescence than children in any other parenting x delay group. Conclusions Authoritative and permissive parenting styles were protective against more rapid BMI gains for boys who could not delay gratification. Ability to delay gratification was protective against BMI gains for boys who had parents with authoritarian or neglectful parenting styles. PMID:23977874

Better concrete mixes for rapid repair in Wisconsin.

DOT National Transportation Integrated Search

2017-04-01

With the increasing demands on the highway system and increasing costs of user delay, the use and development of rapid-repairtechniques are expected to grow rapidly. High early strength (HES) portland cement concrete can help reduce the duration oftr...

Does NGAL reduce costs? A cost analysis of urine NGAL (uNGAL) & serum creatinine (sCr) for acute kidney injury (AKI) diagnosis

PubMed Central

Canetta, Pietro; Forster, Catherine; Sise, Meghan; Maarouf, Omar; Singer, Eugenia; Elger, Antje; Elitok, Saban; Schmidt-Ott, Kai; Barasch, Jonathon

2017-01-01

Introduction Urine neutrophil gelatinase-associated lipocalin (uNGAL) is a sensitive and specific diagnostic test for acute kidney injury (AKI) in the Emergency Department (ED), but its economic impact has not been investigated. We hypothesized that uNGAL used in combination with serum creatinine (sCr) would reduce costs in the management of AKI in patients presenting to the ED in comparison to using sCr alone. Materials and methods A cost simulation model was developed for clinical algorithms to diagnose AKI based on sCr alone vs. uNGAL plus sCr (uNGAL+sCr). A cost minimization analysis was performed to determine total expected costs for patients with AKI. uNGAL test characteristics were validated with eight-hundred forty-nine patients with sCr ≥1.5 from a completed study of 1635 patients recruited from EDs at two U.S. hospitals from 2007–8. Biomarker test, AKI work-up, and diagnostic imaging costs were incorporated. Results For a hypothetical cohort of 10,000 patients, the model predicted that the expected costs were $900 per patient (pp) in the sCr arm and $950 in the uNGAL+sCr arm. uNGAL+sCr resulted in 1,578 fewer patients with delayed diagnosis and treatment than sCr alone (2,013 vs. 436 pts) at center 1 and 1,973 fewer patients with delayed diagnosis and treatment than sCr alone at center 2 (2,227 vs. 254 patients). Although initial evaluation costs at each center were $50 pp higher in with uNGAL+sCr, total costs declined by $408 pp at Center 1 and by $522 pp at Center 2 due to expected reduced delays in diagnosis and treatment. Sensitivity analyses confirmed savings with uNGAL + sCr for a range of cost inputs. Discussion Using uNGAL with sCr as a clinical diagnostic test for AKI may improve patient management and reduce expected costs. Any cost savings would likely result from avoiding delays in diagnosis and treatment and from avoidance of unnecessary testing in patients given a false positive AKI diagnosis by use of sCr alone. PMID:28542336

Foregone benefits of important food crop improvements in Sub-Saharan Africa

PubMed Central

2017-01-01

A number of new crops have been developed that address important traits of particular relevance for smallholder farmers in Africa. Scientists, policy makers, and other stakeholders have raised concerns that the approval process for these new crops causes delays that are often scientifically unjustified. This article develops a real option model for the optimal regulation of a risky technology that enhances economic welfare and reduces malnutrition. We consider gradual adoption of the technology and show that delaying approval reduces uncertainty about perceived risks of the technology. Optimal conditions for approval incorporate parameters of the stochastic processes governing the dynamics of risk. The model is applied to three cases of improved crops, which either are, or are expected to be, delayed by the regulatory process. The benefits and costs of the crops are presented in a partial equilibrium that considers changes in adoption over time and the foregone benefits caused by a delay in approval under irreversibility and uncertainty. We derive the equilibrium conditions where the net-benefits of the technology equal the costs that would justify a delay. The sooner information about the safety of the technology arrive, the lower the costs for justifying a delay need to be i.e. it pays more to delay. The costs of a delay can be substantial: e.g. a one year delay in approval of the pod-borer resistant cowpea in Nigeria will cost the country about 33 million USD to 46 million USD and between 100 and 3,000 lives. PMID:28749984

Expecting More: On Elevating Academic Standards in Public Universities

ERIC Educational Resources Information Center

Stewart, Kenneth D.; Schlegel, Keith W.

2009-01-01

If one hangs around public universities that have less than selective admissions policies, one is bound to hear a litany of complaints about today's students. They lack the attitude required for productive and serious academic work, and too many lack disciplined study habits; they have short attention spans and very little patience with academic…

Importance-Performance Evaluation: A Method of Discerning Successful Program Components.

ERIC Educational Resources Information Center

Hollenhorst, Steven; Ewert, Alan

Questionnaires completed by 53 high school age students from the Voyaguer Outward Bound School (VOBS) were analyzed to determine how well the program met the perceived needs/expectations of the students. Prior to the course, participants ranked the 17 course components in order of perceived importance, and following the course they indicated how…

Development and Evaluation of a Percutaneous Technique for Repairing Proximal Femora With Metastatic Lesions

DTIC Science & Technology

2006-05-01

bedridden , who are wheel-chair bound, or who have short life expectancies). Key Research Accomplishments • 27 FE models were created and analyzed...minimally invasive procedure is a viable option for, at a minimum, situations with low cyclic loading, such as for patients who are bedridden , who are wheel

There is No Shortage of Teachers, Just Skilled Teachers

ERIC Educational Resources Information Center

Freeland, Richard M.

2001-01-01

A wave of teacher retirements is expected just as fewer college-bound students express a preference for teaching careers, and more diverse students reach school age. Former U.S. Education Secretary Richard Riley suggested the nation would need more than 2 million new teachers over the next decade. This article presents some perspectives on…

Quantum error correction of continuous-variable states against Gaussian noise

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

Ralph, T. C.

2011-08-15

We describe a continuous-variable error correction protocol that can correct the Gaussian noise induced by linear loss on Gaussian states. The protocol can be implemented using linear optics and photon counting. We explore the theoretical bounds of the protocol as well as the expected performance given current knowledge and technology.

Joint Chance-Constrained Dynamic Programming

NASA Technical Reports Server (NTRS)

Ono, Masahiro; Kuwata, Yoshiaki; Balaram, J. Bob

2012-01-01

This paper presents a novel dynamic programming algorithm with a joint chance constraint, which explicitly bounds the risk of failure in order to maintain the state within a specified feasible region. A joint chance constraint cannot be handled by existing constrained dynamic programming approaches since their application is limited to constraints in the same form as the cost function, that is, an expectation over a sum of one-stage costs. We overcome this challenge by reformulating the joint chance constraint into a constraint on an expectation over a sum of indicator functions, which can be incorporated into the cost function by dualizing the optimization problem. As a result, the primal variables can be optimized by a standard dynamic programming, while the dual variable is optimized by a root-finding algorithm that converges exponentially. Error bounds on the primal and dual objective values are rigorously derived. We demonstrate the algorithm on a path planning problem, as well as an optimal control problem for Mars entry, descent and landing. The simulations are conducted using a real terrain data of Mars, with four million discrete states at each time step.

Hierarchical decision processes that operate over distinct timescales underlie choice and changes in strategy

PubMed Central

Purcell, Braden A.; Kiani, Roozbeh

2016-01-01

Decision-making in a natural environment depends on a hierarchy of interacting decision processes. A high-level strategy guides ongoing choices, and the outcomes of those choices determine whether or not the strategy should change. When the right decision strategy is uncertain, as in most natural settings, feedback becomes ambiguous because negative outcomes may be due to limited information or bad strategy. Disambiguating the cause of feedback requires active inference and is key to updating the strategy. We hypothesize that the expected accuracy of a choice plays a crucial rule in this inference, and setting the strategy depends on integration of outcome and expectations across choices. We test this hypothesis with a task in which subjects report the net direction of random dot kinematograms with varying difficulty while the correct stimulus−response association undergoes invisible and unpredictable switches every few trials. We show that subjects treat negative feedback as evidence for a switch but weigh it with their expected accuracy. Subjects accumulate switch evidence (in units of log-likelihood ratio) across trials and update their response strategy when accumulated evidence reaches a bound. A computational framework based on these principles quantitatively explains all aspects of the behavior, providing a plausible neural mechanism for the implementation of hierarchical multiscale decision processes. We suggest that a similar neural computation—bounded accumulation of evidence—underlies both the choice and switches in the strategy that govern the choice, and that expected accuracy of a choice represents a key link between the levels of the decision-making hierarchy. PMID:27432960

Hierarchical decision processes that operate over distinct timescales underlie choice and changes in strategy.

PubMed

Purcell, Braden A; Kiani, Roozbeh

2016-08-02

Decision-making in a natural environment depends on a hierarchy of interacting decision processes. A high-level strategy guides ongoing choices, and the outcomes of those choices determine whether or not the strategy should change. When the right decision strategy is uncertain, as in most natural settings, feedback becomes ambiguous because negative outcomes may be due to limited information or bad strategy. Disambiguating the cause of feedback requires active inference and is key to updating the strategy. We hypothesize that the expected accuracy of a choice plays a crucial rule in this inference, and setting the strategy depends on integration of outcome and expectations across choices. We test this hypothesis with a task in which subjects report the net direction of random dot kinematograms with varying difficulty while the correct stimulus-response association undergoes invisible and unpredictable switches every few trials. We show that subjects treat negative feedback as evidence for a switch but weigh it with their expected accuracy. Subjects accumulate switch evidence (in units of log-likelihood ratio) across trials and update their response strategy when accumulated evidence reaches a bound. A computational framework based on these principles quantitatively explains all aspects of the behavior, providing a plausible neural mechanism for the implementation of hierarchical multiscale decision processes. We suggest that a similar neural computation-bounded accumulation of evidence-underlies both the choice and switches in the strategy that govern the choice, and that expected accuracy of a choice represents a key link between the levels of the decision-making hierarchy.

Reactor shutdown delays medical procedures

NASA Astrophysics Data System (ADS)

Gwynne, Peter

2008-01-01

A longer-than-expected maintenance shutdown of the Canadian nuclear reactor that produces North America's entire supply of molybdenum-99 - from which the radioactive isotopes technetium-99 and iodine-131 are made - caused delays to the diagnosis and treatment of thousands of seriously ill patients last month. Technetium-99 is a key component of nuclear-medicine scans, while iodine-131 is used to treat cancer and other diseases of the thyroid. Production eventually resumed, but only after the Canadian government had overruled the Canadian Nuclear Safety Commission (CNSC), which was still concerned about the reactor's safety.

How the Brain Decides When to Work and When to Rest: Dissociation of Implicit-Reactive from Explicit-Predictive Computational Processes

PubMed Central

Meyniel, Florent; Safra, Lou; Pessiglione, Mathias

2014-01-01

A pervasive case of cost-benefit problem is how to allocate effort over time, i.e. deciding when to work and when to rest. An economic decision perspective would suggest that duration of effort is determined beforehand, depending on expected costs and benefits. However, the literature on exercise performance emphasizes that decisions are made on the fly, depending on physiological variables. Here, we propose and validate a general model of effort allocation that integrates these two views. In this model, a single variable, termed cost evidence, accumulates during effort and dissipates during rest, triggering effort cessation and resumption when reaching bounds. We assumed that such a basic mechanism could explain implicit adaptation, whereas the latent parameters (slopes and bounds) could be amenable to explicit anticipation. A series of behavioral experiments manipulating effort duration and difficulty was conducted in a total of 121 healthy humans to dissociate implicit-reactive from explicit-predictive computations. Results show 1) that effort and rest durations are adapted on the fly to variations in cost-evidence level, 2) that the cost-evidence fluctuations driving the behavior do not match explicit ratings of exhaustion, and 3) that actual difficulty impacts effort duration whereas expected difficulty impacts rest duration. Taken together, our findings suggest that cost evidence is implicitly monitored online, with an accumulation rate proportional to actual task difficulty. In contrast, cost-evidence bounds and dissipation rate might be adjusted in anticipation, depending on explicit task difficulty. PMID:24743711

A speed limit for evolution.

PubMed

Worden, R P

1995-09-07

An upper bound on the speed of evolution is derived. The bound concerns the amount of genetic information which is expressed in observable ways in various aspects of the phenotype. The genetic information expressed in some part of the phenotype of a species cannot increase faster than a given rate, determined by the selection pressure on that part. This rate is typically a small fraction of a bit per generation. Total expressed genetic information cannot increase faster than a species-specific rate--typically a few bits per generation. These bounds apply to all aspects of the phenotype, but are particularly relevant to cognition. As brains are highly complex, we expect large amounts of expressed genetic information in the brain--of the order of 100 kilobytes--yet evolutionary changes in brain genetic information are only a fraction of a bit per generation. This has important consequences for cognitive evolution. The limit implies that the human brain differs from the chimpanzee brain by at most 5 kilobytes of genetic design information. This is not enough to define a Language Acquisition Device, unless it depends heavily on pre-existing primate symbolic cognition. Subject to the evolutionary speed limit, in changing environments a simple, modular brain architecture is fitter than more complex ones. This encourages us to look for simplicity in brain design, rather than expecting the brain to be a patchwork of ad hoc adaptations. The limit implies that pure species selection is not an important mechanism of evolutionary change.

Posttraumatic stress symptoms and tobacco abstinence effects in a non-clinical sample: evaluating the mediating role of negative affect reduction smoking expectancies.

PubMed

Langdon, Kirsten J; Leventhal, Adam M

2014-11-01

The relation between posttraumatic stress symptoms and smoking is well documented but poorly understood. The present investigation sought to evaluate the impact of posttraumatic stress symptoms on subjective and behavioral tobacco abstinence effects both directly and indirectly through negative affect reduction smoking outcome expectancies. Participants included 275 (68.7% male; Mage =43.9, 10+ cig/day) adult non-treatment seeking smokers, who attended two counterbalanced laboratory sessions (16 h of smoking deprivation vs ad libitum smoking), during which they completed self-report measures of withdrawal symptoms and mood followed by a smoking lapse task in which they could earn money for delaying smoking and purchase cigarettes to smoke. Results supported a mediational pathway whereby higher baseline symptoms of posttraumatic stress predicted greater endorsement of expectancies that smoking will effectively reduce negative affect, which in turn predicted greater abstinence-provoked exacerbations in nicotine withdrawal symptoms and negative affect. Posttraumatic stress symptoms also predicted number of cigarettes purchased independent of negative affect reduction expectancies, but did not predict delaying smoking for money. Findings highlight tobacco abstinence effects as a putative mechanism underlying posttraumatic stress disorder (PTSD)-smoking comorbidity, indicate an important mediating role of beliefs for smoking-induced negative affect reduction, and shed light on integrated treatment approaches for these two conditions. © The Author(s) 2014.

The behavioral economics of will in recovery from addiction.

PubMed

Monterosso, John; Ainslie, George

2007-09-01

Behavioral economic studies demonstrate that rewards are discounted proportionally with their delay (hyperbolic discounting). Hyperbolic discounting implies temporary preference for smaller rewards when they are imminent, and this concept has been widely considered by researchers interested in the causes of addictive behavior. Far less consideration has been given to the fact that systematic preference reversal also predicts various self-control phenomena, which may also be analyzed from a behavioral economic perspective. Here we summarize self-control phenomena predicted by hyperbolic discounting, particularly with application to the field of addiction. Of greatest interest is the phenomenon of choice bundling, an increase in motivation to wait for delayed rewards that can be expected to result from making choices in whole categories. Specifically, when a person's expectations about her own future behavior are conditional upon her current behavior, the value of these expectations is added to the contingencies for the current behavior, resulting in reduced impulsivity. Hyperbolic discounting provides a bottom-up basis for the intuitive learning of choice bundling, the properties of which match common descriptions of willpower. We suggest that the bundling effect can also be discerned in the advice of 12-step programs.

The behavioral economics of will in recovery from addiction

PubMed Central

Monterosso, John; Ainslie, George

2007-01-01

Behavioral economic studies demonstrate that rewards are discounted proportionally with their delay (hyperbolic discounting). Hyperbolic discounting implies temporary preference for smaller rewards when they are imminent, and this concept has been widely considered by researchers interested in the causes of addictive behavior. Far less consideration has been given to the fact that systematic preference reversal also predicts various self-control phenomena, which may also be analyzed from a behavioral economic perspective. Here we summarize self-control phenomena predicted by hyperbolic discounting, particularly with application to the field of addiction. Of greatest interest is the phenomenon of choice bundling, an increase in motivation to wait for delayed rewards that can be expected to result from making choices in whole categories. Specifically, when a person’s expectations about her own future behavior are conditional upon her current behavior, the value of these expectations is added to the contingencies for the current behavior, resulting in reduced impulsivity. Hyperbolic discounting provides a bottom-up basis for the intuitive learning of choice bundling, the properties of which match common descriptions of willpower. We suggest that the bundling effect can also be discerned in the advice of 12-step programs. PMID:17034958

Delayed repair of distal biceps tendon ruptures is successful: a case-control study.

PubMed

Haverstock, John; Grewal, Ruby; King, Graham J W; Athwal, George S

2017-06-01

The literature has shown an increased complication rate with a delay to surgical repair of acute distal biceps tendon ruptures; however, little has been documented regarding the outcome of delayed repairs. This case-control study compared a study cohort of delayed (>21 days) distal biceps tendon repairs with a control cohort repaired acutely (<21 days). Sixteen delayed repair cases were reviewed and matched with acute controls (1:3) based on repair technique, age, and workers' compensation status. The delayed cohort was reviewed and completed isometric strength testing and the Disabilities of the Arm, Shoulder and Hand questionnaire; Patient-Rated Elbow Evaluation; and American Shoulder and Elbow Surgeons elbow questionnaire. The time to surgery averaged 37 ± 12 days in the delayed cohort versus 10 ± 6 days in the acute cohort. Complications occurred in 63% of patients in the delayed cohort versus 29% in the acute cohort (P = .04); however, 90% of the delayed cohort's complications consisted of transient paresthesias. Follow-up scores on the Patient-Rated Elbow Evaluation, Disabilities of the Arm, Shoulder and Hand questionnaire, and American Shoulder and Elbow Surgeons elbow questionnaire were not statistically different between cohorts (P > .37, P > .22, and P > .46, respectively). Despite a high rate of initial complications, patients treated with distal biceps tendon repair after a delay (>21 days) can expect similar functional outcomes to those treated acutely. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Modelling the impact of causal and non-causal factors on disruption duration for Toronto's subway system: An exploratory investigation using hazard modelling.

PubMed

Louie, Jacob; Shalaby, Amer; Habib, Khandker Nurul

2017-01-01

Most investigations of incident-related delay duration in the transportation context are restricted to highway traffic, with little attention given to delays due to transit service disruptions. Studies of transit-based delay duration are also considerably less comprehensive than their highway counterparts with respect to examining the effects of non-causal variables on the delay duration. However, delays due to incidents in public transit service can have serious consequences on the overall urban transportation system due to the pivotal and vital role of public transit. The ability to predict the durations of various types of transit system incidents is indispensable for better management and mitigation of service disruptions. This paper presents a detailed investigation on incident delay durations in Toronto's subway system over the year 2013, focusing on the effects of the incidents' location and time, the train-type involved, and the non-adherence to proper recovery procedures. Accelerated Failure Time (AFT) hazard models are estimated to investigate the relationship between these factors and the resulting delay duration. The empirical investigation reveals that incident types that impact both safety and operations simultaneously generally have longer expected delays than incident types that impact either safety or operations alone. Incidents at interchange stations are cleared faster than incidents at non-interchange stations. Incidents during peak periods have nearly the same delay durations as off-peak incidents. The estimated models are believed to be useful tools in predicting the relative magnitude of incident delay duration for better management of subway operations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Two synthetic Sp1-binding sites functionally substitute for the 21-base-pair repeat region to activate simian virus 40 growth in CV-1 cells.

PubMed Central

Lednicky, J; Folk, W R

1992-01-01

The 21-bp repeat region of simian virus 40 (SV40) activates viral transcription and DNA replication and contains binding sites for many cellular proteins, including Sp1, LSF, ETF, Ap2, Ap4, GT-1B, H16, and p53, and for the SV40 large tumor antigen. We have attempted to reduce the complexity of this region while maintaining its growth-promoting capacity. Deletion of the 21-bp repeat region from the SV40 genome delays the expression of viral early proteins and DNA replication and reduces virus production in CV-1 cells. Replacement of the 21-bp repeat region with two copies of DNA sequence motifs bound with high affinities by Sp1 promotes SV40 growth in CV-1 cells to nearly wild-type levels, but substitution by motifs bound less avidly by Sp1 or bound by other activator proteins does not restore growth. This indicates that Sp1 or a protein with similar sequence specificity is primarily responsible for the function of the 21-bp repeat region. We speculate about how Sp1 activates both SV40 transcription and DNA replication. Images PMID:1328672

Delay in disclosure of non-parental child sexual abuse in the context of emotional and physical maltreatment: A pilot study.

PubMed

Tashjian, Sarah M; Goldfarb, Deborah; Goodman, Gail S; Quas, Jodi A; Edelstein, Robin

2016-08-01

The present pilot study sought to identify predictors of delays in child sexual abuse (CSA) disclosure, specifically whether emotional and physical abuse by a parental figure contributes to predicting delays over and above other important victim factors. Alleged CSA victims (N=79), whose parental figures were not the purported sexual abuse perpetrators, were interviewed and their case files reviewed, across two waves of a longitudinal study. Regression analyses indicated that experiencing both emotional and physical abuse by a parental figure was uniquely predictive of longer delays in disclosure of CSA perpetrated by someone other than a parental figure. Victim-CSA perpetrator relationship type and sexual abuse duration also significantly predicted CSA disclosure delay, whereas victim age at the time of the police report, victim gender, and victims' feelings of complicity were not significant unique predictors. Child abuse victims' expectations of lack of parental support may underlie these findings. Parent-child relationships are likely crucial to timely disclosure of CSA, even when a parent is not the CSA perpetrator. Copyright © 2016 Elsevier Ltd. All rights reserved.

Statistical Mechanics of the Delayed Reward-Based Learning with Node Perturbation

NASA Astrophysics Data System (ADS)

Hiroshi Saito,; Kentaro Katahira,; Kazuo Okanoya,; Masato Okada,

2010-06-01

In reward-based learning, reward is typically given with some delay after a behavior that causes the reward. In machine learning literature, the framework of the eligibility trace has been used as one of the solutions to handle the delayed reward in reinforcement learning. In recent studies, the eligibility trace is implied to be important for difficult neuroscience problem known as the “distal reward problem”. Node perturbation is one of the stochastic gradient methods from among many kinds of reinforcement learning implementations, and it searches the approximate gradient by introducing perturbation to a network. Since the stochastic gradient method does not require a objective function differential, it is expected to be able to account for the learning mechanism of a complex system, like a brain. We study the node perturbation with the eligibility trace as a specific example of delayed reward-based learning, and analyzed it using a statistical mechanics approach. As a result, we show the optimal time constant of the eligibility trace respect to the reward delay and the existence of unlearnable parameter configurations.

Networked iterative learning control design for discrete-time systems with stochastic communication delay in input and output channels

NASA Astrophysics Data System (ADS)

Liu, Jian; Ruan, Xiaoe

2017-07-01

This paper develops two kinds of derivative-type networked iterative learning control (NILC) schemes for repetitive discrete-time systems with stochastic communication delay occurred in input and output channels and modelled as 0-1 Bernoulli-type stochastic variable. In the two schemes, the delayed signal of the current control input is replaced by the synchronous input utilised at the previous iteration, whilst for the delayed signal of the system output the one scheme substitutes it by the synchronous predetermined desired trajectory and the other takes it by the synchronous output at the previous operation, respectively. In virtue of the mathematical expectation, the tracking performance is analysed which exhibits that for both the linear time-invariant and nonlinear affine systems the two kinds of NILCs are convergent under the assumptions that the probabilities of communication delays are adequately constrained and the product of the input-output coupling matrices is full-column rank. Last, two illustrative examples are presented to demonstrate the effectiveness and validity of the proposed NILC schemes.

A search theory model of patch-to-patch forager movement with application to pollinator-mediated gene flow.

PubMed

Hoyle, Martin; Cresswell, James E

2007-09-07

We present a spatially implicit analytical model of forager movement, designed to address a simple scenario common in nature. We assume minimal depression of patch resources, and discrete foraging bouts, during which foragers fill to capacity. The model is particularly suitable for foragers that search systematically, foragers that deplete resources in a patch only incrementally, and for sit-and-wait foragers, where harvesting does not affect the rate of arrival of forage. Drawing on the theory of job search from microeconomics, we estimate the expected number of patches visited as a function of just two variables: the coefficient of variation of the rate of energy gain among patches, and the ratio of the expected time exploiting a randomly chosen patch and the expected time travelling between patches. We then consider the forager as a pollinator and apply our model to estimate gene flow. Under model assumptions, an upper bound for animal-mediated gene flow between natural plant populations is approximately proportional to the probability that the animal rejects a plant population. In addition, an upper bound for animal-mediated gene flow in any animal-pollinated agricultural crop from a genetically modified (GM) to a non-GM field is approximately proportional to the proportion of fields that are GM and the probability that the animal rejects a field.

On the possibility of observing bound soliton pairs in a wave-breaking-free mode-locked fiber laser

NASA Astrophysics Data System (ADS)

Martel, G.; Chédot, C.; Réglier, V.; Hideur, A.; Ortaç, B.; Grelu, Ph.

2007-02-01

On the basis of numerical simulations, we explain the formation of the stable bound soliton pairs that were experimentally reported in a high-power mode-locked ytterbium fiber laser [Opt. Express 14, 6075 (2006)], in a regime where wave-breaking-free operation is expected. A fully vectorial model allows one to rigorously reproduce the nonmonotonic nature for the nonlinear polarization effect that generally limits the power scalability of a single-pulse self-similar regime. Simulations show that a self-similar regime is not fully obtained, although positive linear chirps and parabolic spectra are always reported. As a consequence, nonvanishing pulse tails allow distant stable binding of highly-chirped pulses.

Asymptotics of the evolution semigroup associated with a scalar field in the presence of a non-linear electromagnetic field

NASA Astrophysics Data System (ADS)

Albeverio, Sergio; Tamura, Hiroshi

2018-04-01

We consider a model describing the coupling of a vector-valued and a scalar homogeneous Markovian random field over R4, interpreted as expressing the interaction between a charged scalar quantum field coupled with a nonlinear quantized electromagnetic field. Expectations of functionals of the random fields are expressed by Brownian bridges. Using this, together with Feynman-Kac-Itô type formulae and estimates on the small time and large time behaviour of Brownian functionals, we prove asymptotic upper and lower bounds on the kernel of the transition semigroup for our model. The upper bound gives faster than exponential decay for large distances of the corresponding resolvent (propagator).

Language in boys with fragile X syndrome.

PubMed

Levy, Yonata; Gottesman, Riki; Borochowitz, Zvi; Frydman, Moshe; Sagi, Michal

2006-02-01

The current paper reports of language production in 15 Hebrew-speaking boys, aged 9;0-13;0, with fully methylated, non-mosaic fragile X syndrome and no concomitant diagnosis of autism. Contrary to expectations, seven children were non-verbal. Language production in the verbal children was studied in free conversations and in context-bound speech. Despite extra caution in calculating MLU, participants' language level was not predicted by mean utterance length. Context bound speech resulted in grammatically more advanced performance than free conversation, and performance in both contexts differed in important ways from performance of typically developing MLU-matched controls. The relevance of MLU as a predictor of productive grammar in disordered populations is briefly discussed.

Current-sheet formation in two-dimensional coronal fields

NASA Astrophysics Data System (ADS)

Billinghurst, M. N.; Craig, I. J. D.; Sneyd, A. D.

1993-11-01

The formation of current sheets by shearing motions in line-tied twin-lobed fields is examined. A general analytic argument shows that current sheets form along the fieldline bounding the two lobes in the case of both symmetric and asymmetric footpoint motions. In the case of strictly antisymmetric motions however no current sheets can form. These findings are reinforced by magnetic relaxation experiments involving sheared two-lobed fields represented by Clebsh variables. It is pointed out that, although current singularites cannot be expected to form when the line-tying assumption is relaxed, the two-lobed geometry is still consistent with the formation of highly localised currents - and strong resistive dissipation - along field lines close to the bounding fieldline.

On the Q-dependence of the lowest-order QED corrections and other properties of the ground 11S-states in the two-electron ions

NASA Astrophysics Data System (ADS)

Frolov, Alexei M.

2015-10-01

Formulas and expectation values which are need to determine the lowest-order QED corrections (∼α3) and corresponding recoil (or finite mass) corrections in the two-electron helium-like ions are presented. Other important properties of the two-electron ions are also determined to high accuracy, including the expectation values of the quasi-singular Vinti operator and < reN-2> and < ree-2> expectation values. Elastic scattering of fast electrons by the two-electron ions in the Born approximation is considered. Interpolation formulas are derived for the bound state properties of the two-electron ions as the function of the nuclear electric charge Q.

The best of both worlds? A review of delayed selfing in flowering plants.

PubMed

Goodwillie, Carol; Weber, Jennifer J

2018-04-01

In a seminal body of theory, Lloyd showed that the fitness consequences of selfing will depend on its timing in anthesis. Selfing that occurs after opportunities for outcrossing or pollen dispersal can provide reproductive assurance when pollinators are limited and is expected to incur little cost, even when inbreeding depression is high. As a result, delayed selfing is often interpreted as a "best-of-both-worlds" mating system that combines the advantages of selfing and outcrossing. We surveyed 65 empirical studies of delayed selfing, recording floral mechanisms and examining information on inbreeding depression, autofertility, and other parameters to test the support for delayed selfing as a best-of-both-worlds strategy. Phylogenetic distribution of the diverse floral mechanisms suggests that some basic floral structures may predispose plant taxa to evolve delayed selfing. Delayed selfing appears to serve as a best-of-both-worlds strategy in some but not all species. While the capacity for autonomous selfing is often high, it is lower, in some cases, than in related species with earlier modes of selfing. In other delayed-selfers, low inbreeding depression and reduced investment in corollas and pollen suggest limited benefits from outcrossing. Despite a growing literature on the subject, experimental evidence for delayed selfing is limited and major gaps in knowledge remain, particularly with respect to the stability of delayed selfing and the conditions that may favor transitions between delayed and earlier selfing. Finally, we suggest a potential role of delayed selfing in facilitating transitions from self-incompatibility to selfing. © 2018 The Authors. American Journal of Botany is published by Wiley Periodicals, Inc. on behalf of the Botanical Society of America.

Short Range Photoassociation of Rb2 by a high power fiber laser

NASA Astrophysics Data System (ADS)

Passagem, Henry; Rodriguez, Ricardo; Ventura, Paulo; Bouloufa, Nadia; Dulieu, Olivier; Marcassa, Luis

2016-05-01

Photoassociation has been studied using cold trapped atomic samples for the last 20 years. Due to poor Franck-Condon overlap, a free-to-bound transition followed by spontaneous decay results in a small production of electronic ground state molecules. If the photoassociation is done at short range, deeply bound ground state molecules can be formed. Optical pumping schemes can be used to populate a single state. In our experiment, we have performed trap loss spectroscopy on trapped 85 Rb atoms in a MOT using a high power fiber laser. Our single mode fiber laser (linewidth < 1 MHz) produces about 50 W, which can be tuned in the 1060-1070 nm range. Two vibrational bound states of the 0u+ potential were observed (ν = 137 and 138). The frequency positions as well as the rotational constants of these states are in good agreement with theoretical predictions. We have also measured the lifetime of a crossed optical dipole trap using such fiber laser. The lifetime on resonance is shorter than off resonance as expected. A simple theoretical model indicates that the molecules decay to deeply bound vibrational levels in the ground state. This work was supported by Fapesp and INCT-IQ.

A time scheduling model of logistics service supply chain based on the customer order decoupling point: a perspective from the constant service operation time.

PubMed

Liu, Weihua; Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

2014-01-01

In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC.

Never Say No … How the Brain Interprets the Pregnant Pause in Conversation

PubMed Central

Bögels, Sara; Kendrick, Kobin H.; Levinson, Stephen C.

2015-01-01

In conversation, negative responses to invitations, requests, offers, and the like are more likely to occur with a delay–conversation analysts talk of them as dispreferred. Here we examine the contrastive cognitive load ‘yes’ and ‘no’ responses make, either when relatively fast (300 ms after question offset) or delayed (1000 ms). Participants heard short dialogues contrasting in speed and valence of response while having their EEG recorded. We found that a fast ‘no’ evokes an N400-effect relative to a fast ‘yes’; however, this contrast disappeared in the delayed responses. 'No' responses, however, elicited a late frontal positivity both if they were fast and if they were delayed. We interpret these results as follows: a fast ‘no’ evoked an N400 because an immediate response is expected to be positive–this effect disappears as the response time lengthens because now in ordinary conversation the probability of a ‘no’ has increased. However, regardless of the latency of response, a ‘no’ response is associated with a late positivity, since a negative response is always dispreferred. Together these results show that negative responses to social actions exact a higher cognitive load, but especially when least expected, in immediate response. PMID:26699335

Effects of lisdexamfetamine dimesylate treatment for ADHD on growth.

PubMed

Faraone, Stephen V; Spencer, Thomas J; Kollins, Scott H; Glatt, Stephen J

2010-01-01

To complete an exploratory uncontrolled study of the effects of lisdexamfetamine dimesylate (LDX) on growth of children treated for attention-deficit/hyperactivity disorder (ADHD). Height, weight, and body mass index (BMI) from 281 children ages 6 to 13 years from longitudinal assessments up to 15 months were compared to norms from the Centers for Disease Control. At study entry, children were taller and heavier than average. Growth delays were largest for weight and BMI, and there was a 13 percentile point decrease in height. Children continued to grow in terms of height while treated with LDX; we found no increase in raw weight or BMI during the study period. LDX treatment was significantly associated with diminished gains in height, weight, and BMI compared to levels that would be expected based on age-appropriate standards from the Centers for Disease Control. Growth delays were greatest for the heaviest and tallest children, for those who had not previously received stimulant therapy, and for those with a greater cumulative exposure to LDX. More work is needed to determine effects on ultimate adult height. Consistent with prior studies of stimulants, treatment with LDX leads to statistically significant reductions in expected height, weight, and BMI. Growth of patients with ADHD treated with LDX should be closely monitored and corrective action taken should growth delays be observed.

A Time Scheduling Model of Logistics Service Supply Chain Based on the Customer Order Decoupling Point: A Perspective from the Constant Service Operation Time

PubMed Central

Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

2014-01-01

In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC. PMID:24715818

Breast implants and breast cancer: a review of incidence, detection, mortality, and survival.

PubMed

Deapen, Dennis

2007-12-01

Soon after breast implants were commercially introduced over 30 years ago, questions about potential carcinogenicity were raised. Animal experiments dating back to the mid-twentieth century demonstrated that foreign body implantation of many materials, including silicone, can induce sarcomas. Indeed, female breast cancer incidence rates in the United States have increased substantially over that period. Of the several published studies from various countries that have formally investigated the risk of breast cancer among augmentation mammaplasty patients, none show any evidence of increased risk. In fact, most find lower than expected risk, some with statistically significant reductions. Similarly, breast cancer mortality among these patients is generally found to be below that expected of other similar women. Delayed detection of breast cancer is a concern for these patients because implants can interfere with mammography. However, using indicators such as stage at diagnosis and tumor size, current research shows that augmentation patients do not experience delayed detection. Furthermore, several comparisons of post-breast cancer survival of augmented versus nonaugmented patients have found no significant differences. In summary, breast implants are not associated with an increased risk of breast cancer incidence or death, and these patients do not experience delayed detection or poorer post-breast cancer survival.

Designed Long-Lived Emission from CdSe Quantum Dots through Reversible Electronic Energy Transfer with a Surface-Bound Chromophore.

PubMed

La Rosa, Marcello; Denisov, Sergey A; Jonusauskas, Gediminas; McClenaghan, Nathan D; Credi, Alberto

2018-03-12

The size-tunable emission of luminescent quantum dots (QDs) makes them highly interesting for applications that range from bioimaging to optoelectronics. For the same applications, engineering their luminescence lifetime, in particular, making it longer, would be as important; however, no rational approach to reach this goal is available to date. We describe a strategy to prolong the emission lifetime of QDs through electronic energy shuttling to the triplet excited state of a surface-bound molecular chromophore. To implement this idea, we made CdSe QDs of different sizes and carried out self-assembly with a pyrene derivative. We observed that the conjugates exhibit delayed luminescence, with emission decays that are prolonged by more than 3 orders of magnitude (lifetimes up to 330 μs) compared to the parent CdSe QDs. The mechanism invokes unprecedented reversible quantum dot to organic chromophore electronic energy transfer. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Airborne laser ranging system for monitoring regional crustal deformation

NASA Technical Reports Server (NTRS)

Degnan, J. J.

1981-01-01

Alternate approaches for making the atmospheric correction without benefit of a ground-based meteorological network are discussed. These include (1) a two-color channel that determines the atmospheric correction by measuring the time delay induced by dispersion between pulses at two optical frequencies; (2) single-color range measurements supported by an onboard temperature sounder, pressure altimeter readings, and surface measurements by a few existing meteorological facilities; and (3) inclusion of the quadratic polynomial coefficients as variables to be solved for along with target coordinates in the reduction of the single-color range data. It is anticipated that the initial Airborne Laser Ranging System (ALRS) experiments will be carried out in Southern California in a region bounded by Santa Barbara on the norht and the Mexican border on the south. The target area will be bounded by the Pacific Ocean to the west and will extend eastward for approximately 400 km. The unique ability of the ALRS to provide a geodetic 'snapshot' of such a large area will make it a valuable geophysical tool.

Rapamycin mitigates erythrocyte membrane transport functions and oxidative stress during aging in rats.

PubMed

Singh, Abhishek Kumar; Singh, Sandeep; Garg, Geetika; Rizvi, Syed Ibrahim

2018-02-01

Erythrocyte membrane is a suitable model to study various metabolic and physiological functions as it undergoes variety of biochemical changes during aging. An age-dependent modulatory effect of rapamycin on erythrocyte membrane functions is completely unknown. Therefore, the present study was undertaken to investigate the effect of rapamycin on age-dependent impaired activities of transporters/exchangers, altered levels of redox biomarkers, viz. protein carbonyl (PC), lipid hydroperoxides (LHs), total thiol (-SH), sialic acid (SA) and intracellular calcium ion [Ca 2+ ]i, and osmotic fragility of erythrocyte membrane. A significant reduction in membrane-bound activities of Na + /K + -ATPase (NKA) and Ca 2+ -ATPase (PMCA), and levels of -SH and SA was observed along with a simultaneous induction in Na + /H + exchanger (NHE) activity and levels of [Ca 2+ ]i, PC, LH and osmotic fragility in old-aged rats. Rapamycin was found to be a promising age-delaying drug that significantly reversed the aging-induced impaired activities of membrane-bound ATPases and altered levels of redox biomarkers.

Indirect signals from solar dark matter annihilation to long-lived right-handed neutrinos

DOE PAGES

Allahverdi, Rouzbeh; Gao, Yu; Knockel, Bradley; ...

2017-04-04

In this paper, we study indirect detection signals from solar annihilation of dark matter (DM) particles into light right-handed (RH) neutrinos with a mass in a 1–5 GeV range. These RH neutrinos can have a sufficiently long lifetime to allow them to decay outside the Sun, and their delayed decays can result in a signal in gamma rays from the otherwise “dark” solar direction, and also a neutrino signal that is not suppressed by the interactions with solar medium. We find that the latest Fermi-LAT and IceCube results place limits on the gamma ray and neutrino signals, respectively. Combined photonmore » and neutrino bounds can constrain the spin-independent DM-nucleon elastic scattering cross section better than direct detection experiments for DM masses from 200 GeV up to several TeV. Finally, the bounds on spin-dependent scattering are also much tighter than the strongest limits from direct detection experiments.« less

Attosecond transient absorption probing of electronic superpositions of bound states in neon. Detection of quantum beats

DOE PAGES

Beck, Annelise R; Bernhardt, Birgitta; Warrick, Erika R.; ...

2014-11-07

Electronic wavepackets composed of multiple bound excited states of atomic neon lying between 19.6 and 21.5 eV are launched using an isolated attosecond pulse. Individual quantum beats of the wavepacket are detected by perturbing the induced polarization of the medium with a time-delayed few-femtosecond near-infrared (NIR) pulse via coupling the individual states to multiple neighboring levels. All of the initially excited states are monitored simultaneously in the attosecond transient absorption spectrum, revealing Lorentzian to Fano lineshape spectral changes as well as quantum beats. The most prominent beating of the several that were observed was in the spin–orbit split 3d absorptionmore » features, which has a 40 femtosecond period that corresponds to the spin–orbit splitting of 0.1 eV. The few-level models and multilevel calculations confirm that the observed magnitude of oscillation depends strongly on the spectral bandwidth and tuning of the NIR pulse and on the location of possible coupling states.« less

Autoradiographic visualization of the mouse egg's sperm receptor bound to sperm

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

Bleil, J.D.; Wassarman, P.M.

1986-04-01

The extracellular coat, or zona pellucida, of mammalian eggs contains species-specific receptors to which sperm bind as a prelude to fertilization. In mice, ZP3, one of only three zona pellucida glycoproteins, serves as sperm receptor. Acrosome-intact, but not acrosome-reacted, mouse sperm recognize and interact with specific O-linked oligosaccharides of ZP3 resulting in sperm-egg binding. Binding, in turn, causes sperm to undergo the acrosome reaction; a membrane fusion event that results in loss of plasma membrane at the anterior region of the head and exposure of inner acrosomal membrane with its associated acrosomal contents. Bound, acrosome-reacted sperm are able to penetratemore » the zona pellucida and fuse with the egg's plasma membrane (fertilization). In the present report, we examined binding of radioiodinated, purified, egg ZP3 to both acrosome intact and acrosome reacted sperm by whole-mount autoradiography. Silver grains due to bound 125I-ZP3 were found localized to the acrosomal cap region of heads of acrosome-reacted sperm. Under the same conditions, 125I-fetuin bound at only background levels to heads of both acrosome-intact and -reacted sperm, and 125I-ZP2, another zona pellucida glycoprotein, bound preferentially to acrosome-reacted sperm. These results provide visual evidence that ZP3 binds preferentially and specifically to heads of acrosome intact sperm; properties expected of the mouse egg's sperm receptor.« less

30-Second bound and pore water concentration mapping of cortical bone using 2D UTE with optimized half-pulses.

PubMed

Manhard, Mary Kate; Harkins, Kevin D; Gochberg, Daniel F; Nyman, Jeffry S; Does, Mark D

2017-03-01

MRI of cortical bone has the potential to offer new information about fracture risk. Current methods are typically performed with 3D acquisitions, which suffer from long scan times and are generally limited to extremities. This work proposes using 2D UTE with half pulses for quantitatively mapping bound and pore water in cortical bone. Half-pulse 2D UTE methods were implemented on a 3T Philips Achieva scanner using an optimized slice-select gradient waveform, with preparation pulses to selectively image bound or pore water. The 2D methods were quantitatively compared with previously implemented 3D methods in the tibia in five volunteers. The mean difference between bound and pore water concentration acquired from 3D and 2D sequences was 0.6 and 0.9 mol 1 H/L bone (3 and 12%, respectively). While 2D pore water methods tended to slightly overestimate concentrations relative to 3D methods, differences were less than scan-rescan uncertainty and expected differences between healthy and fracture-prone bones. Quantitative bound and pore water concentration mapping in cortical bone can be accelerated by 2 orders of magnitude using 2D protocols with optimized half-pulse excitation. Magn Reson Med 77:945-950, 2017. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Trapping of quantum particles and light beams by switchable potential wells

NASA Astrophysics Data System (ADS)

Sonkin, Eduard; Malomed, Boris A.; Granot, Er'El; Marchewka, Avi

2010-09-01

We consider basic dynamical effects in settings based on a pair of local potential traps that may be effectively switched on and off, or suddenly displaced, by means of appropriate control mechanisms, such as scanning tunneling microscopy or photo-switchable quantum dots. The same models, based on the linear Schrödinger equation with time-dependent trapping potentials, apply to the description of optical planar systems designed for the switching of trapped light beams. The analysis is carried out in the analytical form, using exact solutions of the Schrödinger equation. The first dynamical problem considered in this work is the retention of a particle released from a trap which was suddenly turned off, while another local trap was switched on at a distance—immediately or with a delay. In this case, we demonstrate that the maximum of the retention rate is achieved at a specific finite value of the strength of the new trap, and at a finite value of the temporal delay, depending on the distance between the two traps. Another problem is retrapping of the bound particle when the addition of the second trap transforms the single-well setting into a double-well potential (DWP). In that case, we find probabilities for the retrapping into the ground or first excited state of the DWP. We also analyze effects entailed by the application of a kick to a bound particle, the most interesting one being a kick-induced transition between the DWP’s ground and excited states. In the latter case, the largest transition probability is achieved at a particular strength of the kick.

[Delayed identity development, family relationships and psychopathology: Links between healthy and clinically disturbed youth].

PubMed

Seiffge-Krenke, Inge; Escher, Fabian J

2018-05-01

This study compared three groups of various age and health status (total N = 732) with respect to their identity status, stress level, and parental behavior. As expected, patients were characterized by delayed identity development, particularly ruminative exploration. Further, patients experienced high identity stress and described high levels of anxious paternal rearing and intrusive maternal psychological control. The patients‘ levels of both internalizing and externalizing symptomatology were high, and the impact of externalizing symptoms on identity arrest was strong. Identity status was delayed, albeit age adequate in both groups of healthy youths, with comparably high levels of anxious parental monitoring. Compared to adolescents, young adults were particularly active in their identity development, showing a high level of identity stress but no increase in psychopathology.

Immediate effects of form-class constraints on spoken word recognition

PubMed Central

Magnuson, James S.; Tanenhaus, Michael K.; Aslin, Richard N.

2008-01-01

In many domains of cognitive processing there is strong support for bottom-up priority and delayed top-down (contextual) integration. We ask whether this applies to supra-lexical context that could potentially constrain lexical access. Previous findings of early context integration in word recognition have typically used constraints that can be linked to pair-wise conceptual relations between words. Using an artificial lexicon, we found immediate integration of syntactic expectations based on pragmatic constraints linked to syntactic categories rather than words: phonologically similar “nouns” and “adjectives” did not compete when a combination of syntactic and visual information strongly predicted form class. These results suggest that predictive context is integrated continuously, and that previous findings supporting delayed context integration stem from weak contexts rather than delayed integration. PMID:18675408

Working memory effects of gap-predictions in normal adults: an event-related potentials study.

PubMed

Hestvik, Arild; Bradley, Evan; Bradley, Catherine

2012-12-01

The current study examined the relationship between verbal memory span and the latency with which a filler-gap dependency is constructed. A previous behavioral study found that low span listeners did not exhibit antecedent reactivation at gap sites in relative clauses, in comparison to high verbal memory span subjects (Roberts et al. in J Psycholinguist Res 36(2):175-188, 2007), which suggests that low span subjects are delayed at gap filling. This possibility was examined in the current study. Using an event-related potentials paradigm, it was found that low span subjects have an onset latency delay of about 200 ms in brain responses to violations of syntactic expectancies after the gap site, thus providing a time course measure of the delay hypothesized by previous literature.

Uganda Country Analysis Brief

EIA Publications

2016-01-01

Uganda does not produce hydrocarbons currently, but after discovering oil ten years ago, the country is expected to start producing oil within the next decade. Commercial oil production is expected to start at the earliest in 2020 but most likely beyond this period. The production start date has been pushed back several times in the past. Contractual and tax disputes, differences between the Ugandan government and international investors over the portion of oil production to be exported versus refined locally, and disagreements over the export pipeline route have all contributed to a later-than-expected production start date. Sustained low global oil prices have also contributed to delays.

A Prospective Study of Adolescent Pregnancy.

ERIC Educational Resources Information Center

Hockaday, Cathy; Crase, Sedahlia Jasper; Shelley, Mack C., II; Stockdale, Dahlia F.

2000-01-01

Examines prospectively the characteristics contributing to adolescent pregnancy in a pregnant and comparison group of adolescents. Adolescent pregnancy in Blacks was predicted by approval of delaying a family and pursuing a career, aspirations of working, and lower educational expectations. Higher educational wishes, lower educational…

Screening actuator locations for static shape control

NASA Technical Reports Server (NTRS)

Haftka, Raphael T.

1990-01-01

Correction of shape distortion due to zero-mean normally distributed errors in structural sizes which are random variables is examined. A bound on the maximum improvement in the expected value of the root-mean-square shape error is obtained. The shape correction associated with the optimal actuators is also characterized. An actuator effectiveness index is developed and shown to be helpful in screening actuator locations in the structure. The results are specialized to a simple form for truss structures composed of nominally identical members. The bound and effectiveness index are tested on a 55-m radiometer antenna truss structure. It is found that previously obtained results for optimum actuators had a performance close to the bound obtained here. Furthermore, the actuators associated with the optimum design are shown to have high effectiveness indices. Since only a small fraction of truss elements tend to have high effectiveness indices, the proposed screening procedure can greatly reduce the number of truss members that need to be considered as actuator sites.

Parent Perceptions of the Anticipated Needs and Expectations for Support for Their College-Bound Students with Asperger's Syndrome

ERIC Educational Resources Information Center

Morrison, Julie Q.; Sansosti, Frank J.; Hadley, Wanda M.

2009-01-01

Many students with Asperger's Syndrome have the cognitive ability and specific interests to be successful academically at the college level. However, these students often have difficulties navigating social systems, and higher education presents great challenges. The purpose of this study was to explore parent perceptions regarding the: (a)…

New constraints and prospects for sub-GeV dark matter scattering off electrons in xenon

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

Essig, Rouven; Volansky, Tomer; Yu, Tien-Tien

2017-08-30

We study in detail sub-GeV dark matter scattering off electrons in xenon, including the expected electron recoil spectra and annual modulation spectra. We derive improved constraints using low-energy XENON10 and XENON100 ionization-only data. For XENON10, in addition to including electron-recoil data corresponding to about 1–3 electrons, we include for the first time events corresponding to about 4–7 electrons. Assuming the scattering is momentum independent (F DM = 1 ), this strengthens a previous cross-section bound by almost an order of magnitude for dark matter masses above 50 MeV. The available XENON100 data corresponds to events with about 4–50 electrons, andmore » leads to a constraint that is comparable to the XENON10 bound above 50 MeV for F DM = 1 . We demonstrate that a search for an annual modulation signal in upcoming xenon experiments (XENON1T, XENONnT, LZ) could substantially improve the above bounds even in the presence of large backgrounds. We also emphasize that in simple benchmark models of sub-GeV dark matter, the dark matter-electron scattering rate can be as high as one event every ten (two) seconds in the XENON1T (XENONnT or LZ) experiments, without being in conflict with any other known experimental bounds. While there are several sources of backgrounds that can produce single- or few-electron events, a large event rate can be consistent with a dark matter signal and should not be simply written off as purely a detector curiosity. This fact motivates a detailed analysis of the ionization-data (“S2”) data, taking into account the expected annual modulation spectrum of the signal rate, as well as the DM-induced electron-recoil spectra, which are another powerful discriminant between signal and background.« less

Multiple nitrogen isotope recorders for surface ocean nitrate utilization in the Subarctic North Pacific and the Bering Sea

NASA Astrophysics Data System (ADS)

Ren, H. A.; Anderson, R.; Sigman, D. M.; Studer, A.; Winckler, G.; Haugh, G.; Serno, S.; Gersonde, R.

2017-12-01

Sedimentary nitrogen isotopes have been developed as a proxy to reconstruct the degree of nitrate utilization in the polar surface oceans. But its application could be compromised by 1) uncertainties on the biological production, transport, and preservation of the organic material in the sediments, and 2) potential changes in the isotopic composition of the nitrate source, that is remotely controlled by processes in other regions. In this study, we map and compare spatial patterns of three d15N recorders (bulk sedimentary nitrogen, the organic nitrogen within cleaned diatom frustules or diatom-bound N, and within planktonic foraminifera tests or foraminifera-bound N) from multicore surface sediments across the Subarctic North Pacific (SNP) and the Bering Sea between 60°N and 35°N. Diatom-bound d15N varies between 3.5 and 8.5‰. Its spatial variation is reversely correlated with changes in the surface nitrate concentration, and is consistent with the expected d15N change of the export production in a simple nitrate assimilation model. Similar to previous findings, diatom-bound d15N is generally 2 4‰ higher than the modeled d15N value of the export production, likely reflecting a biomass to frustual-bound N difference. However, the greater d15N elevation observed in the eastern open SNP may be best explained by lateral transport of residual surface nitrate enriched in 15N from the western SNP. The d15N of Neogloboquadrina pachyderma (sinistral) is similar to the diatom-bound d15N within 1‰. Bulk sedimentary d15N generally agrees with diatom-bound d15N, but is more variable. It is higher than diatom-bound d15N in the eastern and western transect close to the shelf area, likely reflecting a terrigenous source, while exceptionally low d15N values were found on the Bering Sea shelf, possibly due to contamination by mineral-associated inorganic N.

Acute ethanol effects on neural encoding of reward size and delay in the nucleus accumbens

PubMed Central

Gutman, Andrea L.

2016-01-01

Acute ethanol administration can cause impulsivity, resulting in increased preference for immediately available rewards over delayed but more valuable alternatives. The manner in which reward size and delay are represented in neural firing is not fully understood, and very little is known about ethanol effects on this encoding. To address this issue, we used in vivo electrophysiology to characterize neural firing in the core of the nucleus accumbens (NAcc) in rats responding for rewards that varied in size or delay after vehicle or ethanol administration. The NAcc is a central element in the circuit that governs decision-making and importantly, promotes choice of delayed rewards. We found that NAcc firing in response to reward-predictive cues encoded anticipated reward value after vehicle administration, but ethanol administration disrupted this encoding, resulting in a loss of discrimination between immediate and delayed rewards in cue-evoked neural responses. In addition, NAcc firing occurring at the time of the operant response (lever pressing) was inversely correlated with behavioral response latency, such that increased firing rates were associated with decreased latencies to lever press. Ethanol administration selectively attenuated this lever press-evoked firing when delayed but not immediate rewards were expected. These effects on neural firing were accompanied by increased behavioral latencies to respond for delayed rewards. Our results suggest that ethanol effects on NAcc cue- and lever press-evoked encoding may contribute to ethanol-induced impulsivity. PMID:27169507

Cascading Delay Risk of Airline Workforce Deployments with Crew Pairing and Schedule Optimization.

PubMed

Chung, Sai Ho; Ma, Hoi Lam; Chan, Hing Kai

2017-08-01

This article concerns the assignment of buffer time between two connected flights and the number of reserve crews in crew pairing to mitigate flight disruption due to flight arrival delay. Insufficient crew members for a flight will lead to flight disruptions such as delays or cancellations. In reality, most of these disruption cases are due to arrival delays of the previous flights. To tackle this problem, many research studies have examined the assignment method based on the historical flight arrival delay data of the concerned flights. However, flight arrival delays can be triggered by numerous factors. Accordingly, this article proposes a new forecasting approach using a cascade neural network, which considers a massive amount of historical flight arrival and departure data. The approach also incorporates learning ability so that unknown relationships behind the data can be revealed. Based on the expected flight arrival delay, the buffer time can be determined and a new dynamic reserve crew strategy can then be used to determine the required number of reserve crews. Numerical experiments are carried out based on one year of flight data obtained from 112 airports around the world. The results demonstrate that by predicting the flight departure delay as the input for the prediction of the flight arrival delay, the prediction accuracy can be increased. Moreover, by using the new dynamic reserve crew strategy, the total crew cost can be reduced. This significantly benefits airlines in flight schedule stability and cost saving in the current big data era. © 2016 Society for Risk Analysis.

Measuring Information-Transfer Delays

PubMed Central

Wibral, Michael; Pampu, Nicolae; Priesemann, Viola; Siebenhühner, Felix; Seiwert, Hannes; Lindner, Michael; Lizier, Joseph T.; Vicente, Raul

2013-01-01

In complex networks such as gene networks, traffic systems or brain circuits it is important to understand how long it takes for the different parts of the network to effectively influence one another. In the brain, for example, axonal delays between brain areas can amount to several tens of milliseconds, adding an intrinsic component to any timing-based processing of information. Inferring neural interaction delays is thus needed to interpret the information transfer revealed by any analysis of directed interactions across brain structures. However, a robust estimation of interaction delays from neural activity faces several challenges if modeling assumptions on interaction mechanisms are wrong or cannot be made. Here, we propose a robust estimator for neuronal interaction delays rooted in an information-theoretic framework, which allows a model-free exploration of interactions. In particular, we extend transfer entropy to account for delayed source-target interactions, while crucially retaining the conditioning on the embedded target state at the immediately previous time step. We prove that this particular extension is indeed guaranteed to identify interaction delays between two coupled systems and is the only relevant option in keeping with Wiener’s principle of causality. We demonstrate the performance of our approach in detecting interaction delays on finite data by numerical simulations of stochastic and deterministic processes, as well as on local field potential recordings. We also show the ability of the extended transfer entropy to detect the presence of multiple delays, as well as feedback loops. While evaluated on neuroscience data, we expect the estimator to be useful in other fields dealing with network dynamics. PMID:23468850

Time-resolved delayed luminescence image microscopy using an europium ion chelate complex.

PubMed Central

Marriott, G.; Heidecker, M.; Diamandis, E. P.; Yan-Marriott, Y.

1994-01-01

Improvements and extended applications of time-resolved delayed luminescence imaging microscopy (TR-DLIM) in cell biology are described. The emission properties of europium ion complexed to a fluorescent chelating group capable of labeling proteins are exploited to provide high contrast images of biotin labeled ligands through detection of the delayed emission. The streptavidin-based macromolecular complex (SBMC) employs streptavidin cross-linked to thyroglobulin multiply labeled with the europium-fluorescent chelate. The fluorescent chelate is efficiently excited with 340-nm light, after which it sensitizes europium ion emission at 612 nm hundreds of microseconds later. The SBMC complex has a high quantum yield orders of magnitude higher than that of eosin, a commonly used delayed luminescent probe, and can be readily seen by the naked eye, even in specimens double-labeled with prompt fluorescent probes. Unlike triplet-state phosphorescent probes, sensitized europium ion emission is insensitive to photobleaching and quenching by molecular oxygen; these properties have been exploited to obtain delayed luminescence images of living cells in aerated medium thus complementing imaging studies using prompt fluorescent probes. Since TR-DLIM has the unique property of rejecting enormous signals that originate from scattered light, autofluorescence, and prompt fluorescence it has been possible to resolve double emission images of living amoeba cells containing an intensely stained lucifer yellow in pinocytosed vesicles and membrane surface-bound SBMC-labeled biotinylated concanavalin A. Images of fixed cells represented in terms of the time decay of the sensitized emission show the lifetime of the europium ion emission is sensitive to the environment in which it is found. Through the coupling of SBMC to streptavidin,a plethora of biotin-based tracer molecules are available for immunocytochemical studies. Images FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 PMID:7811952

The neural basis of cultural differences in delay discounting

PubMed Central

Kim, Bokyung; Sung, Young Shin; McClure, Samuel M.

2012-01-01

People generally prefer to receive rewarding outcomes sooner rather than later. Such preferences result from delay discounting, or the process by which outcomes are devalued for the expected delay until their receipt. We investigated cultural differences in delay discounting by contrasting behaviour and brain activity in separate cohorts of Western (American) and Eastern (Korean) subjects. Consistent with previous reports, we find a dramatic difference in discounting behaviour, with Americans displaying much greater present bias and elevated discount rates. Recent neuroimaging findings suggest that differences in discounting may arise from differential involvement of either brain reward areas or regions in the prefrontal and parietal cortices associated with cognitive control. We find that the ventral striatum is more greatly recruited in Americans relative to Koreans when discounting future rewards, but there is no difference in prefrontal or parietal activity. This suggests that a cultural difference in emotional responsivity underlies the observed behavioural effect. We discuss the implications of this research for strategic interrelations between Easterners and Westerners. PMID:22271781

Emotional arousal and discount rate in intertemporal choice are reference dependent.

PubMed

Lempert, Karolina M; Glimcher, Paul W; Phelps, Elizabeth A

2015-04-01

Many decisions involve weighing immediate gratification against future consequences. In such intertemporal choices, people often choose smaller, immediate rewards over larger delayed rewards. It has been proposed that emotional responses to immediate rewards lead us to choose them at our long-term expense. Here we utilize an objective measure of emotional arousal-pupil dilation-to examine the role of emotion in these decisions. We show that emotional arousal responses, as well as choices, in intertemporal choice tasks are reference-dependent and reflect the decision-maker's recent history of offers. Arousal increases when less predictable rewards are better than expected, whether those rewards are immediate or delayed. Furthermore, when immediate rewards are less predictable than delayed rewards, participants tend to be patient. When delayed rewards are less predictable, immediate rewards are preferred. Our findings suggest that we can encourage people to be more patient by changing the context in which intertemporal choices are made. (c) 2015 APA, all rights reserved).

Delayed system response times affect immediate physiology and the dynamics of subsequent button press behavior.

PubMed

Kohrs, Christin; Hrabal, David; Angenstein, Nicole; Brechmann, André

2014-11-01

System response time research is an important issue in human-computer interactions. Experience with technical devices and general rules of human-human interactions determine the user's expectation, and any delay in system response time may lead to immediate physiological, emotional, and behavioral consequences. We investigated such effects on a trial-by-trial basis during a human-computer interaction by measuring changes in skin conductance (SC), heart rate (HR), and the dynamics of button press responses. We found an increase in SC and a deceleration of HR for all three delayed system response times (0.5, 1, 2 s). Moreover, the data on button press dynamics was highly informative since subjects repeated a button press with more force in response to delayed system response times. Furthermore, the button press dynamics could distinguish between correct and incorrect decisions and may thus even be used to infer the uncertainty of a user's decision. Copyright © 2014 Society for Psychophysiological Research.

Decomposing Differences in Medical Care Access Among Cancer Survivors by Race and Ethnicity

PubMed Central

Chen, Jie; Dagher, Rada K.; Holt, Cheryl L.; Thomas, Stephen B.

2014-01-01

More research is needed to identify significant factors that explain why minority cancer survivors ages 18-64 are more likely to delay or forgo care when compared with whites. Data were merged from the 2000-2011 National Health Interview Survey to identify 12,125 adult survivors who delayed care due to cost, organization and transportation barriers. The Fairlie decomposition technique was applied to explore contributing factors. Compared to whites, Hispanics were more likely to delay medical or treatment due to organizational barriers (OR: 1.38; p<.05) and African Americans were more likely to delay care due to transportation barriers (OR: 1.54; p<.05). Age, insurance, perceived health, comorbidity, nativity and year were leading factors that contributed to the disparities. While expanded insurance coverage through the Affordable Care Act is expected to increase access, it is important to recognize the role of organizational convenience and transportation in facilitating timely health services for survivors. PMID:24904178

Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns

PubMed Central

Matsubara, Takashi

2017-01-01

Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning. PMID:29209191

Conduction Delay Learning Model for Unsupervised and Supervised Classification of Spatio-Temporal Spike Patterns.

PubMed

Matsubara, Takashi

2017-01-01

Precise spike timing is considered to play a fundamental role in communications and signal processing in biological neural networks. Understanding the mechanism of spike timing adjustment would deepen our understanding of biological systems and enable advanced engineering applications such as efficient computational architectures. However, the biological mechanisms that adjust and maintain spike timing remain unclear. Existing algorithms adopt a supervised approach, which adjusts the axonal conduction delay and synaptic efficacy until the spike timings approximate the desired timings. This study proposes a spike timing-dependent learning model that adjusts the axonal conduction delay and synaptic efficacy in both unsupervised and supervised manners. The proposed learning algorithm approximates the Expectation-Maximization algorithm, and classifies the input data encoded into spatio-temporal spike patterns. Even in the supervised classification, the algorithm requires no external spikes indicating the desired spike timings unlike existing algorithms. Furthermore, because the algorithm is consistent with biological models and hypotheses found in existing biological studies, it could capture the mechanism underlying biological delay learning.

The effect of aperture averaging upon tropospheric delay fluctuations seen with a DSN antenna

NASA Technical Reports Server (NTRS)

Linfield, R.

1996-01-01

The spectrum of tropospheric delay fluctuations expected for a DSN antenna at time scales less than 100 s has been calculated. A new feature included in these calculations is the effect of aperture averaging, which causes a reduction in delay fluctuations on time scales less than the antenna wind speed crossing time, approximately equal to 5-10 s. On time scales less than a few seconds, the Allan deviation sigma(sub y)(Delta(t)) varies as (Delta(t))(sup +1), rather than sigma(sub y)(Delta(t)) varies as (Delta(t))(exp -1/6) without aperture averaging. Due to thermal radiometer noise, calibration of tropospheric delay fluctuations with water vapor radiometers will not be possible on time scales less than approximately 10 s. However, the tropospheric fluctuation level will be small enough that radio science measurements with a spacecraft on time scales less than a few seconds will be limited by the stability of frequency standards and/or other nontropospheric effects.

Biochemical transport modeling, estimation, and detection in realistic environments

NASA Astrophysics Data System (ADS)

Ortner, Mathias; Nehorai, Arye

2006-05-01

Early detection and estimation of the spread of a biochemical contaminant are major issues for homeland security applications. We present an integrated approach combining the measurements given by an array of biochemical sensors with a physical model of the dispersion and statistical analysis to solve these problems and provide system performance measures. We approximate the dispersion model of the contaminant in a realistic environment through numerical simulations of reflected stochastic diffusions describing the microscopic transport phenomena due to wind and chemical diffusion using the Feynman-Kac formula. We consider arbitrary complex geometries and account for wind turbulence. Localizing the dispersive sources is useful for decontamination purposes and estimation of the cloud evolution. To solve the associated inverse problem, we propose a Bayesian framework based on a random field that is particularly powerful for localizing multiple sources with small amounts of measurements. We also develop a sequential detector using the numerical transport model we propose. Sequential detection allows on-line analysis and detecting wether a change has occurred. We first focus on the formulation of a suitable sequential detector that overcomes the presence of unknown parameters (e.g. release time, intensity and location). We compute a bound on the expected delay before false detection in order to decide the threshold of the test. For a fixed false-alarm rate, we obtain the detection probability of a substance release as a function of its location and initial concentration. Numerical examples are presented for two real-world scenarios: an urban area and an indoor ventilation duct.

Reversible geminate recombination of hydrogen-bonded water molecule pair

NASA Astrophysics Data System (ADS)

Markovitch, Omer; Agmon, Noam

2008-08-01

The (history independent) autocorrelation function for a hydrogen-bonded water molecule pair, calculated from classical molecular dynamics trajectories of liquid water, exhibits a t-3/2 asymptotic tail. Its whole time dependence agrees quantitatively with the solution for reversible diffusion-influenced geminate recombination derived by Agmon and Weiss [J. Chem. Phys. 91, 6937 (1989)]. Agreement with diffusion theory is independent of the precise definition of the bound state. Given the water self-diffusion constant, this theory enables us to determine the dissociation and bimolecular recombination rate parameters for a water dimer. (The theory is indispensable for obtaining the bimolecular rate coefficient.) Interestingly, the activation energies obtained from the temperature dependence of these rate coefficients are similar, rather than differing by the hydrogen-bond (HB) strength. This suggests that recombination requires displacing another water molecule, which meanwhile occupied the binding site. Because these activation energies are about twice the HB strength, cleavage of two HBs may be required to allow pair separation. The autocorrelation function without the HB angular restriction yields a recombination rate coefficient that is larger than that for rebinding to all four tetrahedral water sites (with angular restrictions), suggesting the additional participation of interstitial sites. Following dissociation, the probability of the pair to be unbound but within the reaction sphere rises more slowly than expected, possibly because binding to the interstitial sites delays pair separation. An extended diffusion model, which includes an additional binding site, can account for this behavior.

How CMB and large-scale structure constrain chameleon interacting dark energy

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

Boriero, Daniel; Das, Subinoy; Wong, Yvonne Y.Y., E-mail: boriero@physik.uni-bielefeld.de, E-mail: subinoy@iiap.res.in, E-mail: yvonne.y.wong@unsw.edu.au

2015-07-01

We explore a chameleon type of interacting dark matter-dark energy scenario in which a scalar field adiabatically traces the minimum of an effective potential sourced by the dark matter density. We discuss extensively the effect of this coupling on cosmological observables, especially the parameter degeneracies expected to arise between the model parameters and other cosmological parameters, and then test the model against observations of the cosmic microwave background (CMB) anisotropies and other cosmological probes. We find that the chameleon parameters α and β, which determine respectively the slope of the scalar field potential and the dark matter-dark energy coupling strength,more » can be constrained to α < 0.17 and β < 0.19 using CMB data and measurements of baryon acoustic oscillations. The latter parameter in particular is constrained only by the late Integrated Sachs-Wolfe effect. Adding measurements of the local Hubble expansion rate H{sub 0} tightens the bound on α by a factor of two, although this apparent improvement is arguably an artefact of the tension between the local measurement and the H{sub 0} value inferred from Planck data in the minimal ΛCDM model. The same argument also precludes chameleon models from mimicking a dark radiation component, despite a passing similarity between the two scenarios in that they both delay the epoch of matter-radiation equality. Based on the derived parameter constraints, we discuss possible signatures of the model for ongoing and future large-scale structure surveys.« less

Rapid genetic restoration of a keystone species exhibiting delayed demographic response

USDA-ARS?s Scientific Manuscript database

Genetic founder effects are often expected when animals colonize restored habitat in fragmented landscapes, but empirical data on genetic responses to restoration are limited. We examined the genetic response of banner-tailed kangaroo rats (Dipodomys spectabilis) to landscape-scale grassland restor...

Emotional Memory Persists Longer than Event Memory

ERIC Educational Resources Information Center

Kuriyama, Kenichi; Soshi, Takahiro; Fujii, Takeshi; Kim, Yoshiharu

2010-01-01

The interaction between amygdala-driven and hippocampus-driven activities is expected to explain why emotion enhances episodic memory recognition. However, overwhelming behavioral evidence regarding the emotion-induced enhancement of immediate and delayed episodic memory recognition has not been obtained in humans. We found that the recognition…

Periodic protein adsorption at the gold/biotin aqueous solution interface: evidence of kinetics with time delay

NASA Astrophysics Data System (ADS)

Neff, H.; Laborde, H. M.; Lima, A. M. N.

2016-11-01

An oscillatory molecular adsorption pattern of the protein neutravidin from aqueous solution onto gold, in presence of a pre-deposited self assembled mono-molecular biotin film, is reported. Real time surface Plasmon resonance sensing was utilized for evaluation of the adsorption kinetics. Two different fractions were identified: in the initial phase, protein molecules attach irreversibly onto the Biotin ligands beneath towards the jamming limit, forming a neutravidin-biotin fraction. Afterwards, the growth rate exhibits distinct, albeit damped adsorption-desorption oscillations over an extended time span, assigned to a quasi reversibly bound fraction. These findings agree with, and firstly confirm a previously published model, proposing macro-molecular adsorption with time delay. The non-linear dynamic model is applicable to and also resembles non-damped oscillatory binding features of the hetero-catalytic oxidation of carbon monoxide molecules on platinum in the gas phase. An associated surface residence time can be linked to the dynamics and time scale required for self-organization.

Warm Dark Matter and Cosmic Reionization

DOE PAGES

Villanueva-Domingo, Pablo; Gnedin, Nickolay Y.; Mena, Olga

2018-01-10

In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3 keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn–Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in bothmore » CDM and WDM models, the full distribution of Gunn–Peterson optical depth retains the strong signature of delayed reionization in the WDM model. Furthermore, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent.« less

Flight parameter estimation using instantaneous frequency and time delay measurements from a three-element planar acoustic array.

PubMed

Lo, Kam W

2016-05-01

The acoustic signal emitted by a turbo-prop aircraft consists of a strong narrowband tone superimposed on a broadband random component. A ground-based three-element planar acoustic array can be used to estimate the full set of flight parameters of a turbo-prop aircraft in transit by measuring the time delay (TD) between the signal received at the reference sensor and the signal received at each of the other two sensors of the array over a sufficiently long period of time. This paper studies the possibility of using instantaneous frequency (IF) measurements from the reference sensor to improve the precision of the flight parameter estimates. A simplified Cramer-Rao lower bound analysis shows that the standard deviations in the estimates of the aircraft velocity and altitude can be greatly reduced when IF measurements are used together with TD measurements. Two flight parameter estimation algorithms that utilize both IF and TD measurements are formulated and their performances are evaluated using both simulated and real data.

Warm Dark Matter and Cosmic Reionization

NASA Astrophysics Data System (ADS)

Villanueva-Domingo, Pablo; Gnedin, Nickolay Y.; Mena, Olga

2018-01-01

In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3 keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn–Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in both CDM and WDM models, the full distribution of Gunn–Peterson optical depth retains the strong signature of delayed reionization in the WDM model. However, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent.

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

NASA Technical Reports Server (NTRS)

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

1978-01-01

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

Adaptive Backstepping-Based Neural Tracking Control for MIMO Nonlinear Switched Systems Subject to Input Delays.

PubMed

Niu, Ben; Li, Lu

2018-06-01

This brief proposes a new neural-network (NN)-based adaptive output tracking control scheme for a class of disturbed multiple-input multiple-output uncertain nonlinear switched systems with input delays. By combining the universal approximation ability of radial basis function NNs and adaptive backstepping recursive design with an improved multiple Lyapunov function (MLF) scheme, a novel adaptive neural output tracking controller design method is presented for the switched system. The feature of the developed design is that different coordinate transformations are adopted to overcome the conservativeness caused by adopting a common coordinate transformation for all subsystems. It is shown that all the variables of the resulting closed-loop system are semiglobally uniformly ultimately bounded under a class of switching signals in the presence of MLF and that the system output can follow the desired reference signal. To demonstrate the practicability of the obtained result, an adaptive neural output tracking controller is designed for a mass-spring-damper system.

Warm Dark Matter and Cosmic Reionization

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

Villanueva-Domingo, Pablo; Gnedin, Nickolay Y.; Mena, Olga

In models with dark matter made of particles with keV masses, such as a sterile neutrino, small-scale density perturbations are suppressed, delaying the period at which the lowest mass galaxies are formed and therefore shifting the reionization processes to later epochs. In this study, focusing on Warm Dark Matter (WDM) with masses close to its present lower bound, i.e., around the 3 keV region, we derive constraints from galaxy luminosity functions, the ionization history and the Gunn–Peterson effect. We show that even if star formation efficiency in the simulations is adjusted to match the observed UV galaxy luminosity functions in bothmore » CDM and WDM models, the full distribution of Gunn–Peterson optical depth retains the strong signature of delayed reionization in the WDM model. Furthermore, until the star formation and stellar feedback model used in modern galaxy formation simulations is constrained better, any conclusions on the nature of dark matter derived from reionization observables remain model-dependent.« less

BPTAP: A New Approach to IP over DTN

NASA Technical Reports Server (NTRS)

Tsao, Philip; Nguyen, Sam

2012-01-01

Traditional Internet protocols have been widely deployed for a variety of applications. However such protocols generally perform poorly in situations in which, round trip delays are very large (interplanetary distances) or . persistent connectivity is not always available (widely dispersed MANET). Delay/Disruption Tolerant Network (DTN) technology was invented to address these issues: (1) . Relay nodes "take custody" of blocks of network traffic on a hop-by -hop basis and retransmit them in cases of expected or unexpected link outage (2) Bundle lifetime may be configured for long round trip light times. BPTAP is novel by encapsulating Ethernet frames in BP

Care Utilization with China's New Rural Cooperative Medical Scheme: Updated Evidence from the China Health and Retirement Longitudinal Study 2011-2012.

PubMed

Zhang, Donglan; Shi, Lu; Tian, Fang; Zhang, Lingling

2016-12-01

China's New Rural Cooperative Medical Scheme (NRCMS), a healthcare financing system for rural residents in China, underwent significant enhancement since 2008. Studies based on pre-2008 NRCMS data showed an increase in inpatient care utilization after NRCMS coverage. However evidence was mixed for the relationship between outpatient care use and NRCMS coverage. We assessed whether enrollment in the enhanced NRCMS was associated with less delaying or foregoing medical care, as a reduction in foregoing needed care signals about removing liquidity constraint among the enrollees. Using a national sample of rural residents (N = 12,740) from the 2011-2012 wave of China Health and Retirement Longitudinal Study, we examined the association between NRCMS coverage and the likelihood of delaying or foregoing medical care (outpatient and inpatient) by survey-weighted regression models controlling for demographics, education, geographic regions, household expenditures, pre-existing chronic diseases, and access to local healthcare facilities. Zero-inflated negative binomial model was used to estimate the association between NRCMS coverage and number of medical visits. NRCMS coverage was significantly associated with lower odds of delaying or foregoing inpatient care (OR: 0.42, 95 % CI: 0.22-0.81). A negative but insignificant association was found between NRCMS coverage and delaying/foregoing outpatient care when ill. Among those who needed health care, the expected number of outpatient visits for NRCMS enrollees was 1.35 (95 % CI: 1.03-1.77) times of those uninsured, and the expected number of inpatient visits for NRCMS enrollees was 1.83 (95 % CI: 1.16-2.88) times of those uninsured. This study shows that the enhanced NRCMS coverage was associated with less delaying or foregoing inpatient care deemed as necessary by health professionals, which is likely to result from improved financial reimbursement of the NRCMS.

A statistical study of radio-source structure effects on astrometric very long baseline interferometry observations

NASA Technical Reports Server (NTRS)

Ulvestad, J. S.

1989-01-01

Errors from a number of sources in astrometric very long baseline interferometry (VLBI) have been reduced in recent years through a variety of methods of calibration and modeling. Such reductions have led to a situation in which the extended structure of the natural radio sources used in VLBI is a significant error source in the effort to improve the accuracy of the radio reference frame. In the past, work has been done on individual radio sources to establish the magnitude of the errors caused by their particular structures. The results of calculations on 26 radio sources are reported in which an effort is made to determine the typical delay and delay-rate errors for a number of sources having different types of structure. It is found that for single observations of the types of radio sources present in astrometric catalogs, group-delay and phase-delay scatter in the 50 to 100 psec range due to source structure can be expected at 8.4 GHz on the intercontinental baselines available in the Deep Space Network (DSN). Delay-rate scatter of approx. 5 x 10(exp -15) sec sec(exp -1) (or approx. 0.002 mm sec (exp -1) is also expected. If such errors mapped directly into source position errors, they would correspond to position uncertainties of approx. 2 to 5 nrad, similar to the best position determinations in the current JPL VLBI catalog. With the advent of wider bandwidth VLBI systems on the large DSN antennas, the system noise will be low enough so that the structure-induced errors will be a significant part of the error budget. Several possibilities for reducing the structure errors are discussed briefly, although it is likely that considerable effort will have to be devoted to the structure problem in order to reduce the typical error by a factor of two or more.

Strong expectations cancel locality effects: evidence from Hindi.

PubMed

Husain, Samar; Vasishth, Shravan; Srinivasan, Narayanan

2014-01-01

Expectation-driven facilitation (Hale, 2001; Levy, 2008) and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005) are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

Strong Expectations Cancel Locality Effects: Evidence from Hindi

PubMed Central

Husain, Samar; Vasishth, Shravan; Srinivasan, Narayanan

2014-01-01

Expectation-driven facilitation (Hale, 2001; Levy, 2008) and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005) are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech “verb” is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge. PMID:25010700

No spreading across the southern Juan de Fuca ridge axial cleft during 1994-1996

USGS Publications Warehouse

Chadwell, C.D.; Hildebrand, J.A.; Spiess, Fred N.; Morton, J.L.; Normark, W.R.; Reiss, C.A.

1999-01-01

Direct-path acoustic measurements between seafloor transponders observed no significant extension (-10 ?? 14 mm/yr) from August 1994 to September 1996 at the southern Juan de Fuca Ridge (44??40' N and 130??20' W). The acoustic path for the measurement is a 691-m baseline straddling the axial cleft, which bounds the Pacific and Juan de Fuca plates. Given an expected full-spreading rate of 56 mm/yr, these data suggest that extension across this plate boundary occurs episodically within the narrow (~1 km) region of the axial valley floor, and that active deformation is occurring between the axial cleft and the plate interior. A cleft-parallel 714-m baseline located 300 m to the west of the cleft on the Pacific plate monitored system performance and, as expected, observed no motion (+5??7 mm/yr) between the 1994 and 1996 surveys.Direct-path acoustic measurements between seafloor transponders observed no significant extension (-10 ?? 14 mm/yr) from August 1994 to September 1996 at the southern Juan de Fuca Ridge (44??40 minutes N and 130??20 minutes W). The acoustic path for the measurement is a 691-m baseline straddling the axial cleft, which bounds the Pacific and Juan de Fuca plates. Given an expected full-spreading rate of 56 mm/yr, these data suggest that extension across this plate boundary occurs episodically within the narrow (approx. 1 km) region of the axial valley floor, and that active deformation is occurring between the axial cleft and the plate interior. A cleft-parallel 714-m baseline located 300 m to the west of the cleft on the Pacific plate monitored system performance and, as expected, observed no motion (+5 ?? 7 mm/yr) between the 1994 and 1996 surveys.

Methodology for Analysis, Modeling and Simulation of Airport Gate-waiting Delays

NASA Astrophysics Data System (ADS)

Wang, Jianfeng

This dissertation presents methodologies to estimate gate-waiting delays from historical data, to identify gate-waiting-delay functional causes in major U.S. airports, and to evaluate the impact of gate operation disruptions and mitigation strategies on gate-waiting delay. Airport gates are a resource of congestion in the air transportation system. When an arriving flight cannot pull into its gate, the delay it experiences is called gate-waiting delay. Some possible reasons for gate-waiting delay are: the gate is occupied, gate staff or equipment is unavailable, the weather prevents the use of the gate (e.g. lightning), or the airline has a preferred gate assignment. Gate-waiting delays potentially stay with the aircraft throughout the day (unless they are absorbed), adding costs to passengers and the airlines. As the volume of flights increases, ensuring that airport gates do not become a choke point of the system is critical. The first part of the dissertation presents a methodology for estimating gate-waiting delays based on historical, publicly available sources. Analysis of gate-waiting delays at major U.S. airports in the summer of 2007 identifies the following. (i) Gate-waiting delay is not a significant problem on majority of days; however, the worst delay days (e.g. 4% of the days at LGA) are extreme outliers. (ii) The Atlanta International Airport (ATL), the John F. Kennedy International Airport (JFK), the Dallas/Fort Worth International Airport (DFW) and the Philadelphia International Airport (PHL) experience the highest gate-waiting delays among major U.S. airports. (iii) There is a significant gate-waiting-delay difference between airlines due to a disproportional gate allocation. (iv) Gate-waiting delay is sensitive to time of a day and schedule peaks. According to basic principles of queueing theory, gate-waiting delay can be attributed to over-scheduling, higher-than-scheduled arrival rate, longer-than-scheduled gate-occupancy time, and reduced gate availability. Analysis of the worst days at six major airports in the summer of 2007 indicates that major gate-waiting delays are primarily due to operational disruptions---specifically, extended gate occupancy time, reduced gate availability and higher-than-scheduled arrival rate (usually due to arrival delay). Major gate-waiting delays are not a result of over-scheduling. The second part of this dissertation presents a simulation model to evaluate the impact of gate operational disruptions and gate-waiting-delay mitigation strategies, including building new gates, implementing common gates, using overnight off-gate parking and adopting self-docking gates. Simulation results show the following effects of disruptions: (i) The impact of arrival delay in a time window (e.g. 7 pm to 9 pm) on gate-waiting delay is bounded. (ii) The impact of longer-than-scheduled gate-occupancy times in a time window on gate-waiting delay can be unbounded and gate-waiting delay can increase linearly as the disruption level increases. (iii) Small reductions in gate availability have a small impact on gate-waiting delay due to slack gate capacity, while larger reductions have a non-linear impact as slack gate capacity is used up. Simulation results show the following effects of mitigation strategies: (i) Implementing common gates is an effective mitigation strategy, especially for airports with a flight schedule not dominated by one carrier, such as LGA. (ii) The overnight off-gate rule is effective in mitigating gate-waiting delay for flights stranded overnight following departure cancellations. This is especially true at airports where the gate utilization is at maximum overnight, such as LGA and DFW. The overnight off-gate rule can also be very effective to mitigate gate-waiting delay due to operational disruptions in evenings. (iii) Self-docking gates are effective in mitigating gate-waiting delay due to reduced gate availability.

Inactivation properties of voltage-gated K+ channels altered by presence of beta-subunit.

PubMed

Rettig, J; Heinemann, S H; Wunder, F; Lorra, C; Parcej, D N; Dolly, J O; Pongs, O

1994-05-26

Structural and functional diversity of voltage-gated Kv1-type potassium channels in rat brain is enhanced by the association of two different types of subunits, the membrane-bound, poreforming alpha-subunits and a peripheral beta-subunit. We have cloned a beta-subunit (Kv beta 1) that is specifically expressed in the rat nervous system. Association of Kv beta 1 with alpha-subunits confers rapid A-type inactivation on non-inactivating Kv1 channels (delayed rectifiers) in expression systems in vitro. This effect is mediated by an inactivating ball domain in the Kv beta 1 amino terminus.

Sum rules for quasifree scattering of hadrons

NASA Astrophysics Data System (ADS)

Peterson, R. J.

2018-02-01

The areas d σ /d Ω of fitted quasifree scattering peaks from bound nucleons for continuum hadron-nucleus spectra measuring d2σ /d Ω d ω are converted to sum rules akin to the Coulomb sums familiar from continuum electron scattering spectra from nuclear charge. Hadronic spectra with or without charge exchange of the beam are considered. These sums are compared to the simple expectations of a nonrelativistic Fermi gas, including a Pauli blocking factor. For scattering without charge exchange, the hadronic sums are below this expectation, as also observed with Coulomb sums. For charge exchange spectra, the sums are near or above the simple expectation, with larger uncertainties. The strong role of hadron-nucleon in-medium total cross sections is noted from use of the Glauber model.

Echo-level compensation and delay tuning in the auditory cortex of the mustached bat.

PubMed

Macías, Silvio; Mora, Emanuel C; Hechavarría, Julio C; Kössl, Manfred

2016-06-01

During echolocation, bats continuously perform audio-motor adjustments to optimize detection efficiency. It has been demonstrated that bats adjust the amplitude of their biosonar vocalizations (known as 'pulses') to stabilize the amplitude of the returning echo. Here, we investigated this echo-level compensation behaviour by swinging mustached bats on a pendulum towards a reflective surface. In such a situation, the bats lower the amplitude of their emitted pulses to maintain the amplitude of incoming echoes at a constant level as they approach a target. We report that cortical auditory neurons that encode target distance have receptive fields that are optimized for dealing with echo-level compensation. In most cortical delay-tuned neurons, the echo amplitude eliciting the maximum response matches the echo amplitudes measured from the bats' biosonar vocalizations while they are swung in a pendulum. In addition, neurons tuned to short target distances are maximally responsive to low pulse amplitudes while neurons tuned to long target distances respond maximally to high pulse amplitudes. Our results suggest that bats dynamically adjust biosonar pulse amplitude to match the encoding of target range and to keep the amplitude of the returning echo within the bounds of the cortical map of echo delays. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Robust PI and PID design for first- and second-order processes with zeros, time-delay and structured uncertainties

NASA Astrophysics Data System (ADS)

Parada, M.; Sbarbaro, D.; Borges, R. A.; Peres, P. L. D.

2017-01-01

The use of robust design techniques such as the one based on ? and ? for tuning proportional integral (PI) and proportional integral derivative (PID) controllers have been limited to address a small set of processes. This work addresses the problem by considering a wide set of possible plants, both first- and second-order continuous-time systems with time delays and zeros, leading to PI and PID controllers. The use of structured uncertainties to handle neglected dynamics allows to expand the range of processes to be considered. The proposed approach takes into account the robustness of the controller with respect to these structured uncertainties by using the small-gain theorem. In addition, improved performance is sought through the minimisation of an upper bound to the closed-loop system ? norm. A Lyapunov-Krasovskii-type functional is used to obtain delay-dependent design conditions. The controller design is accomplished by means of a convex optimisation procedure formulated using linear matrix inequalities. In order to illustrate the flexibility of the approach, several examples considering recycle compensation, reduced-order controller design and a practical implementation are addressed. Numerical experiments are provided in each case to highlight the main characteristics of the proposed design method.

Time-Varying Delay Estimation Applied to the Surface Electromyography Signals Using the Parametric Approach

NASA Astrophysics Data System (ADS)

Luu, Gia Thien; Boualem, Abdelbassit; Duy, Tran Trung; Ravier, Philippe; Butteli, Olivier

Muscle Fiber Conduction Velocity (MFCV) can be calculated from the time delay between the surface electromyographic (sEMG) signals recorded by electrodes aligned with the fiber direction. In order to take into account the non-stationarity during the dynamic contraction (the most daily life situation) of the data, the developed methods have to consider that the MFCV changes over time, which induces time-varying delays and the data is non-stationary (change of Power Spectral Density (PSD)). In this paper, the problem of TVD estimation is considered using a parametric method. First, the polynomial model of TVD has been proposed. Then, the TVD model parameters are estimated by using a maximum likelihood estimation (MLE) strategy solved by a deterministic optimization technique (Newton) and stochastic optimization technique, called simulated annealing (SA). The performance of the two techniques is also compared. We also derive two appropriate Cramer-Rao Lower Bounds (CRLB) for the estimated TVD model parameters and for the TVD waveforms. Monte-Carlo simulation results show that the estimation of both the model parameters and the TVD function is unbiased and that the variance obtained is close to the derived CRBs. A comparison with non-parametric approaches of the TVD estimation is also presented and shows the superiority of the method proposed.

CAN LARGE TIME DELAYS OBSERVED IN LIGHT CURVES OF CORONAL LOOPS BE EXPLAINED IN IMPULSIVE HEATING?

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

Lionello, Roberto; Linker, Jon A.; Mikić, Zoran

The light curves of solar coronal loops often peak first in channels associated with higher temperatures and then in those associated with lower temperatures. The delay times between the different narrowband EUV channels have been measured for many individual loops and recently for every pixel of an active region observation. The time delays between channels for an active region exhibit a wide range of values. The maximum time delay in each channel pair can be quite large, i.e., >5000 s. These large time delays make-up 3%–26% (depending on the channel pair) of the pixels where a trustworthy, positive time delaymore » is measured. It has been suggested that these time delays can be explained by simple impulsive heating, i.e., a short burst of energy that heats the plasma to a high temperature, after which the plasma is allowed to cool through radiation and conduction back to its original state. In this paper, we investigate whether the largest observed time delays can be explained by this hypothesis by simulating a series of coronal loops with different heating rates, loop lengths, abundances, and geometries to determine the range of expected time delays between a set of four EUV channels. We find that impulsive heating cannot address the largest time delays observed in two of the channel pairs and that the majority of the large time delays can only be explained by long, expanding loops with photospheric abundances. Additional observations may rule out these simulations as an explanation for the long time delays. We suggest that either the time delays found in this manner may not be representative of real loop evolution, or that the impulsive heating and cooling scenario may be too simple to explain the observations, and other potential heating scenarios must be explored.« less

PIPS-SBB: A Parallel Distributed-Memory Branch-and-Bound Algorithm for Stochastic Mixed-Integer Programs

DOE PAGES

Munguia, Lluis-Miquel; Oxberry, Geoffrey; Rajan, Deepak

2016-05-01

Stochastic mixed-integer programs (SMIPs) deal with optimization under uncertainty at many levels of the decision-making process. When solved as extensive formulation mixed- integer programs, problem instances can exceed available memory on a single workstation. In order to overcome this limitation, we present PIPS-SBB: a distributed-memory parallel stochastic MIP solver that takes advantage of parallelism at multiple levels of the optimization process. We also show promising results on the SIPLIB benchmark by combining methods known for accelerating Branch and Bound (B&B) methods with new ideas that leverage the structure of SMIPs. Finally, we expect the performance of PIPS-SBB to improve furthermore » as more functionality is added in the future.« less

Optimization of fringe-type laser anemometers for turbine engine component testing

NASA Technical Reports Server (NTRS)

Seasholtz, R. G.; Oberle, L. G.; Weikle, D. H.

1984-01-01

The fringe type laser anemometer is analyzed using the Cramer-Rao bound for the variance of the estimate of the Doppler frequency as a figure of merit. Mie scattering theory is used to calculate the Doppler signal wherein both the amplitude and phase of the scattered light are taken into account. The noise from wall scatter is calculated using the wall bidirectional reflectivity and the irradiance of the incident beams. A procedure is described to determine the optimum aperture mask for the probe volume located a given distance from a wall. The expected performance of counter type processors is also discussed in relation to the Cramer-Rao bound. Numerical examples are presented for a coaxial backscatter anemometer.

Bounds on quantum communication via Newtonian gravity

NASA Astrophysics Data System (ADS)

Kafri, D.; Milburn, G. J.; Taylor, J. M.

2015-01-01

Newtonian gravity yields specific observable consequences, the most striking of which is the emergence of a 1/{{r}2} force. In so far as communication can arise via such interactions between distant particles, we can ask what would be expected for a theory of gravity that only allows classical communication. Many heuristic suggestions for gravity-induced decoherence have this restriction implicitly or explicitly in their construction. Here we show that communication via a 1/{{r}2} force has a minimum noise induced in the system when the communication cannot convey quantum information, in a continuous time analogue to Bell's inequalities. Our derived noise bounds provide tight constraints from current experimental results on any theory of gravity that does not allow quantum communication.

A pleiotropy-informed Bayesian false discovery rate adapted to a shared control design finds new disease associations from GWAS summary statistics.

PubMed

Liley, James; Wallace, Chris

2015-02-01

Genome-wide association studies (GWAS) have been successful in identifying single nucleotide polymorphisms (SNPs) associated with many traits and diseases. However, at existing sample sizes, these variants explain only part of the estimated heritability. Leverage of GWAS results from related phenotypes may improve detection without the need for larger datasets. The Bayesian conditional false discovery rate (cFDR) constitutes an upper bound on the expected false discovery rate (FDR) across a set of SNPs whose p values for two diseases are both less than two disease-specific thresholds. Calculation of the cFDR requires only summary statistics and have several advantages over traditional GWAS analysis. However, existing methods require distinct control samples between studies. Here, we extend the technique to allow for some or all controls to be shared, increasing applicability. Several different SNP sets can be defined with the same cFDR value, and we show that the expected FDR across the union of these sets may exceed expected FDR in any single set. We describe a procedure to establish an upper bound for the expected FDR among the union of such sets of SNPs. We apply our technique to pairwise analysis of p values from ten autoimmune diseases with variable sharing of controls, enabling discovery of 59 SNP-disease associations which do not reach GWAS significance after genomic control in individual datasets. Most of the SNPs we highlight have previously been confirmed using replication studies or larger GWAS, a useful validation of our technique; we report eight SNP-disease associations across five diseases not previously declared. Our technique extends and strengthens the previous algorithm, and establishes robust limits on the expected FDR. This approach can improve SNP detection in GWAS, and give insight into shared aetiology between phenotypically related conditions.

Analysis of Optimal Jitter Buffer Size for VoIP QoS under WiMAX Power-Saving Mode

NASA Astrophysics Data System (ADS)

Kim, Hyungsuk; Kim, Taehyoun

VoIP service is expected as one of the key applications of Mobile WiMAX, but the speech quality of VoIP service often suffers deterioration due to the fluctuating transmission delay called jitter. This is commonly ameliorated by a de-jitter buffer, and we aim to find the optimal size of de-jitter buffer to achieve speech quality comparable to PSTN. We developed a new model of the packet drops at the de-jitter buffer and the end-to-end packet delay which takes account of the additional delay introduced by the WiMAX power-saving mode. Using our model, we analyzed the optimal size of the de-jitter buffer for various network parameters, and showed that the results obtained by analysis accord with simulation results.

Hierarchical Type Stability Criteria for Delayed Neural Networks via Canonical Bessel-Legendre Inequalities.

PubMed

Zhang, Xian-Ming; Han, Qing-Long; Zeng, Zhigang

2018-05-01

This paper is concerned with global asymptotic stability of delayed neural networks. Notice that a Bessel-Legendre inequality plays a key role in deriving less conservative stability criteria for delayed neural networks. However, this inequality is in the form of Legendre polynomials and the integral interval is fixed on . As a result, the application scope of the Bessel-Legendre inequality is limited. This paper aims to develop the Bessel-Legendre inequality method so that less conservative stability criteria are expected. First, by introducing a canonical orthogonal polynomial sequel, a canonical Bessel-Legendre inequality and its affine version are established, which are not explicitly in the form of Legendre polynomials. Moreover, the integral interval is shifted to a general one . Second, by introducing a proper augmented Lyapunov-Krasovskii functional, which is tailored for the canonical Bessel-Legendre inequality, some sufficient conditions on global asymptotic stability are formulated for neural networks with constant delays and neural networks with time-varying delays, respectively. These conditions are proven to have a hierarchical feature: the higher level of hierarchy, the less conservatism of the stability criterion. Finally, three numerical examples are given to illustrate the efficiency of the proposed stability criteria.

Joint Maximum Likelihood Time Delay Estimation of Unknown Event-Related Potential Signals for EEG Sensor Signal Quality Enhancement

PubMed Central

Kim, Kyungsoo; Lim, Sung-Ho; Lee, Jaeseok; Kang, Won-Seok; Moon, Cheil; Choi, Ji-Woong

2016-01-01

Electroencephalograms (EEGs) measure a brain signal that contains abundant information about the human brain function and health. For this reason, recent clinical brain research and brain computer interface (BCI) studies use EEG signals in many applications. Due to the significant noise in EEG traces, signal processing to enhance the signal to noise power ratio (SNR) is necessary for EEG analysis, especially for non-invasive EEG. A typical method to improve the SNR is averaging many trials of event related potential (ERP) signal that represents a brain’s response to a particular stimulus or a task. The averaging, however, is very sensitive to variable delays. In this study, we propose two time delay estimation (TDE) schemes based on a joint maximum likelihood (ML) criterion to compensate the uncertain delays which may be different in each trial. We evaluate the performance for different types of signals such as random, deterministic, and real EEG signals. The results show that the proposed schemes provide better performance than other conventional schemes employing averaged signal as a reference, e.g., up to 4 dB gain at the expected delay error of 10°. PMID:27322267

Delaying the international spread of pandemic influenza.

PubMed

Cooper, Ben S; Pitman, Richard J; Edmunds, W John; Gay, Nigel J

2006-06-01

The recent emergence of hypervirulent subtypes of avian influenza has underlined the potentially devastating effects of pandemic influenza. Were such a virus to acquire the ability to spread efficiently between humans, control would almost certainly be hampered by limited vaccine supplies unless global spread could be substantially delayed. Moreover, the large increases that have occurred in international air travel might be expected to lead to more rapid global dissemination than in previous pandemics. To evaluate the potential of local control measures and travel restrictions to impede global dissemination, we developed stochastic models of the international spread of influenza based on extensions of coupled epidemic transmission models. These models have been shown to be capable of accurately forecasting local and global spread of epidemic and pandemic influenza. We show that under most scenarios restrictions on air travel are likely to be of surprisingly little value in delaying epidemics, unless almost all travel ceases very soon after epidemics are detected. Interventions to reduce local transmission of influenza are likely to be more effective at reducing the rate of global spread and less vulnerable to implementation delays than air travel restrictions. Nevertheless, under the most plausible scenarios, achievable delays are small compared with the time needed to accumulate substantial vaccine stocks.

The Clustering of Galaxies and Dark Matter at Intermediate Redshifts

NASA Technical Reports Server (NTRS)

Jain, Bhuvnesh; Szalay, Alexander

2003-01-01

Theoretical work in the study of weak lensing was begun while the Scientific PI (Jain) was at the Johns Hopkins University. A new postdoctoral fellow, Rita Kim, was hired to work for 0.5 years on the proposed research. She was unable to join JHU until March 2001 owing to delays in her PhD work. Meanwhile PI Jain moved to the University of Pennsylvania in January 2001. Owing to the above circumstances, the work for the proposed research was delayed and was expected to be carried out in the remainder of 2001. New measures of lensing based on the magnification effect were to be investigated by Drs. Jain and Kim. The simulations needed to test the analytical computations were already in place; hence the work was expected to proceed fairly rapidly. Owing to the close proximity of JHU and UPenn, the collaborative work was expected to proceed smoothly. It was requested therefore that the funds for the first grant year (2000-2001) be transferred to the second year. Part of the funding was spent at JHU on the salary for the Postdoctoral Fellow, Rita Kim, and the remainder at the University of Pennsylvania. The work from this grant is incomplete and will be continued under another grant.

Adolescents’ Changing Future Expectations Predict the Timing of Adult Role Transitions

PubMed Central

Beal, Sarah J.; Crockett, Lisa J.; Peugh, James

2016-01-01

Individual differences in the transition to adulthood are well established. This study examines the extent to which heterogeneity in pathways to adulthood that have been observed in the broader U.S. population are mirrored in adolescents’ expectations regarding when they will experience key adult role transitions (e.g., marriage). Patterns of change in adolescents’ expectations and the relations between their expectations and subsequent role transitions are also explored. Data from 626 youth in Grade 11 (M age = 16), Grade 12, and early adulthood (M age = 23) are analyzed using mover-stayer latent transition analysis. Results indicate three profiles of expected timing, corresponding to youth who anticipate early role entry (i.e., early starters), youth who anticipate earlier entry into employment but no other roles (i.e., employment-focused), and youth who anticipate delays in role transitions favoring increased education (i.e., education-focused). Two-thirds of youths changed their expectations from Grade 11 to 12. Grade 11 and 12 profile membership predicted role transitions in early adulthood. These findings highlight the importance of adolescents’ expectations and changes in expectations across time in shaping entry into adulthood. PMID:27548390

Home Visitation Assessing Progress, Managing Expectations

ERIC Educational Resources Information Center

Daro, Deborah

2006-01-01

Early intervention efforts to promote healthy child development have long been a central feature of social service and public health reforms. Today, prenatal care, well-baby visits, and assessments to detect possible developmental delays are commonplace in most communities. Recently, child abuse prevention advocates have applied a developmental…

Absent Apologies

ERIC Educational Resources Information Center

Drew, Paul; Hepburn, Alexa

2016-01-01

Absent apologies--apologies that were expected but are not forthcoming--are quite frequently identified and commented on, for instance in the media. In this article we discuss two kinds of evidence that apologies can be "noticeably" absent for participants in ordinary interactions. The first kind is the delays that can occur in the…

Speckle-Suppression Apparatus

NASA Technical Reports Server (NTRS)

Taback, Israel

1989-01-01

Technique and apparatus developed to reduce speckle in unmodulated laser pulses, using reduced number of optical fibers. Expected to decrease costs of bundles of optical fibers used to transmit unmodulated laser pulses. New apparatus reduces speckle in optically transmitted, unmodulated laser input pulse by introducing number of independent delays into pulse.

Development of a Traffic Management Decision Support Tool for Freeway Incident Traffic Management (FITM) Plan Deployment : Research Summary

DOT National Transportation Integrated Search

2017-12-01

In designing an effective traffic management plan for non-recurrent congestion, it is critical for responsible highway agencies to have some vital information, such as estimated incident duration, resulting traffic queues, and the expected delays. Ov...

Whose Writing Is it Anyway?: Issues of Control in the Teaching of Writing

ERIC Educational Resources Information Center

Fisher, Ros

2006-01-01

In the UK, teachers have moved from a process approach to the teaching of writing to a more didactic and objectives led programme. This has given rise to concerns about the suppression of creativity and enjoyment. Writing is a convention bound activity where spelling, punctuation and expectations about different text types imply a right and wrong…

EVALUATION OF RISKS AND WASTE CHARACTERIZATION REQUIREMENTS FOR THE TRANSURANIC WASTE EMPLACED IN WIPP DURING 1999

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

Channell, J.K.; Walker, B.A.

2000-05-01

Specifically this report: 1. Compares requirements of the WAP that are pertinent from a technical viewpoint with the WIPP pre-Permit waste characterization program, 2. Presents the results of a risk analysis of the currently emplaced wastes. Expected and bounding risks from routine operations and possible accidents are evaluated; and 3. Provides conclusions and recommendations.

Academic Preparedness and College Preparation Efforts: A Comparative Analysis of Perception of High School Advanced Placement Teachers and College Admissions Personnel

ERIC Educational Resources Information Center

Driver, Jason Hughes

2014-01-01

This study examines the relationship between high school efforts at post-secondary preparation for college bound students and the expectations of college and university admissions personnel. The Advanced Placement (AP) teachers and administrators at a rural Northwest Florida high school were administered a quantitative survey in order to collect…

Pseudospectral calculation of helium wave functions, expectation values, and oscillator strength

NASA Astrophysics Data System (ADS)

Grabowski, Paul E.; Chernoff, David F.

2011-10-01

We show that the pseudospectral method is a powerful tool for finding precise solutions of Schrödinger’s equation for two-electron atoms with general angular momentum. Realizing the method’s full promise for atomic calculations requires special handling of singularities due to two-particle Coulomb interactions. We give a prescription for choosing coordinates and subdomains whose efficacy we illustrate by solving several challenging problems. One test centers on the determination of the nonrelativistic electric dipole oscillator strength for the helium 11S→21P transition. The result achieved, 0.27616499(27), is comparable to the best in the literature. The formally equivalent length, velocity, and acceleration expressions for the oscillator strength all yield roughly the same accuracy. We also calculate a diverse set of helium ground-state expectation values, reaching near state-of-the-art accuracy without the necessity of implementing any special-purpose numerics. These successes imply that general matrix elements are directly and reliably calculable with pseudospectral methods. A striking result is that all the relevant quantities tested in this paper—energy eigenvalues, S-state expectation values and a bound-bound dipole transition between the lowest energy S and P states—converge exponentially with increasing resolution and at roughly the same rate. Each individual calculation samples and weights the configuration space wave function uniquely but all behave in a qualitatively similar manner. These results suggest that the method has great promise for similarly accurate treatment of few-particle systems.

The anatomy of choice: dopamine and decision-making

PubMed Central

Friston, Karl; Schwartenbeck, Philipp; FitzGerald, Thomas; Moutoussis, Michael; Behrens, Timothy; Dolan, Raymond J.

2014-01-01

This paper considers goal-directed decision-making in terms of embodied or active inference. We associate bounded rationality with approximate Bayesian inference that optimizes a free energy bound on model evidence. Several constructs such as expected utility, exploration or novelty bonuses, softmax choice rules and optimism bias emerge as natural consequences of free energy minimization. Previous accounts of active inference have focused on predictive coding. In this paper, we consider variational Bayes as a scheme that the brain might use for approximate Bayesian inference. This scheme provides formal constraints on the computational anatomy of inference and action, which appear to be remarkably consistent with neuroanatomy. Active inference contextualizes optimal decision theory within embodied inference, where goals become prior beliefs. For example, expected utility theory emerges as a special case of free energy minimization, where the sensitivity or inverse temperature (associated with softmax functions and quantal response equilibria) has a unique and Bayes-optimal solution. Crucially, this sensitivity corresponds to the precision of beliefs about behaviour. The changes in precision during variational updates are remarkably reminiscent of empirical dopaminergic responses—and they may provide a new perspective on the role of dopamine in assimilating reward prediction errors to optimize decision-making. PMID:25267823

The anatomy of choice: dopamine and decision-making.

PubMed

Friston, Karl; Schwartenbeck, Philipp; FitzGerald, Thomas; Moutoussis, Michael; Behrens, Timothy; Dolan, Raymond J

2014-11-05

This paper considers goal-directed decision-making in terms of embodied or active inference. We associate bounded rationality with approximate Bayesian inference that optimizes a free energy bound on model evidence. Several constructs such as expected utility, exploration or novelty bonuses, softmax choice rules and optimism bias emerge as natural consequences of free energy minimization. Previous accounts of active inference have focused on predictive coding. In this paper, we consider variational Bayes as a scheme that the brain might use for approximate Bayesian inference. This scheme provides formal constraints on the computational anatomy of inference and action, which appear to be remarkably consistent with neuroanatomy. Active inference contextualizes optimal decision theory within embodied inference, where goals become prior beliefs. For example, expected utility theory emerges as a special case of free energy minimization, where the sensitivity or inverse temperature (associated with softmax functions and quantal response equilibria) has a unique and Bayes-optimal solution. Crucially, this sensitivity corresponds to the precision of beliefs about behaviour. The changes in precision during variational updates are remarkably reminiscent of empirical dopaminergic responses-and they may provide a new perspective on the role of dopamine in assimilating reward prediction errors to optimize decision-making.

The use of artificially intelligent agents with bounded rationality in the study of economic markets

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

Rajan, V.; Slagle, J.R.

The concepts of {open_quote}knowledge{close_quote} and {open_quote}rationality{close_quote} are of central importance to fields of science that are interested in human behavior and learning, such as artificial intelligence, economics, and psychology. The similarity between artificial intelligence and economics - both are concerned with intelligent thought, rational behavior, and the use and acquisition of knowledge - has led to the use of economic models as a paradigm for solving problems in distributed artificial intelligence (DAI) and multi agent systems (MAS). What we propose is the opposite; the use of artificial intelligence in the study of economic markets. Over the centuries various theories ofmore » market behavior have been advanced. The prevailing theory holds that an asset`s current price converges to the risk adjusted value of the rationally expected dividend stream. While this rational expectations model holds in equilibrium or near-equilibrium conditions, it does not sufficiently explain conditions of market disequilibrium. An example of market disequilibrium is the phenomenon of a speculative bubble. We present an example of using artificially intelligent agents with bounded rationality in the study of speculative bubbles.« less

Optimism in the face of uncertainty supported by a statistically-designed multi-armed bandit algorithm.

PubMed

Kamiura, Moto; Sano, Kohei

2017-10-01

The principle of optimism in the face of uncertainty is known as a heuristic in sequential decision-making problems. Overtaking method based on this principle is an effective algorithm to solve multi-armed bandit problems. It was defined by a set of some heuristic patterns of the formulation in the previous study. The objective of the present paper is to redefine the value functions of Overtaking method and to unify the formulation of them. The unified Overtaking method is associated with upper bounds of confidence intervals of expected rewards on statistics. The unification of the formulation enhances the universality of Overtaking method. Consequently we newly obtain Overtaking method for the exponentially distributed rewards, numerically analyze it, and show that it outperforms UCB algorithm on average. The present study suggests that the principle of optimism in the face of uncertainty should be regarded as the statistics-based consequence of the law of large numbers for the sample mean of rewards and estimation of upper bounds of expected rewards, rather than as a heuristic, in the context of multi-armed bandit problems. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of Dementia and Alzheimer’s Disease in an Older Population: Updated Incidence and Life Expectancy With and Without Dementia

PubMed Central

Tom, Sarah E.; Hubbard, Rebecca A.; Crane, Paul K.; Haneuse, Sebastien J.; Bowen, James; McCormick, Wayne C.; McCurry, Susan; Larson, Eric B.

2015-01-01

Objectives. We estimated dementia incidence rates, life expectancies with and without dementia, and percentage of total life expectancy without dementia. Methods. We studied 3605 members of Group Health (Seattle, WA) aged 65 years or older who did not have dementia at enrollment to the Adult Changes in Thought study between 1994 and 2008. We estimated incidence rates of Alzheimer’s disease and dementia, as well as life expectancies with and without dementia, defined as the average number of years one is expected to live with and without dementia, and percentage of total life expectancy without dementia. Results. Dementia incidence increased through ages 85 to 89 years (74.2 cases per 1000 person-years) and 90 years or older (105 cases per 1000 person-years). Life expectancy without dementia and percentage of total life expectancy without dementia decreased with age. Life expectancy with dementia was longer in women and people with at least a college degree. Percentage of total life expectancy without dementia was greater in younger age groups, men, and those with more education. Conclusions. Efforts to delay onset of dementia, if successful, would likely benefit older adults of all ages. PMID:25033130

Semilocal density functional obeying a strongly tightened bound for exchange

PubMed Central

Sun, Jianwei; Perdew, John P.; Ruzsinszky, Adrienn

2015-01-01

Because of its useful accuracy and efficiency, density functional theory (DFT) is one of the most widely used electronic structure theories in physics, materials science, and chemistry. Only the exchange-correlation energy is unknown, and needs to be approximated in practice. Exact constraints provide useful information about this functional. The local spin-density approximation (LSDA) was the first constraint-based density functional. The Lieb–Oxford lower bound on the exchange-correlation energy for any density is another constraint that plays an important role in the development of generalized gradient approximations (GGAs) and meta-GGAs. Recently, a strongly and optimally tightened lower bound on the exchange energy was proved for one- and two-electron densities, and conjectured for all densities. In this article, we present a realistic “meta-GGA made very simple” (MGGA-MVS) for exchange that respects this optimal bound, which no previous beyond-LSDA approximation satisfies. This constraint might have been expected to worsen predicted thermochemical properties, but in fact they are improved over those of the Perdew–Burke–Ernzerhof GGA, which has nearly the same correlation part. MVS exchange is however radically different from that of other GGAs and meta-GGAs. Its exchange enhancement factor has a very strong dependence upon the orbital kinetic energy density, which permits accurate energies even with the drastically tightened bound. When this nonempirical MVS meta-GGA is hybridized with 25% of exact exchange, the resulting global hybrid gives excellent predictions for atomization energies, reaction barriers, and weak interactions of molecules. PMID:25561554

Semilocal density functional obeying a strongly tightened bound for exchange.

PubMed

Sun, Jianwei; Perdew, John P; Ruzsinszky, Adrienn

2015-01-20

Because of its useful accuracy and efficiency, density functional theory (DFT) is one of the most widely used electronic structure theories in physics, materials science, and chemistry. Only the exchange-correlation energy is unknown, and needs to be approximated in practice. Exact constraints provide useful information about this functional. The local spin-density approximation (LSDA) was the first constraint-based density functional. The Lieb-Oxford lower bound on the exchange-correlation energy for any density is another constraint that plays an important role in the development of generalized gradient approximations (GGAs) and meta-GGAs. Recently, a strongly and optimally tightened lower bound on the exchange energy was proved for one- and two-electron densities, and conjectured for all densities. In this article, we present a realistic "meta-GGA made very simple" (MGGA-MVS) for exchange that respects this optimal bound, which no previous beyond-LSDA approximation satisfies. This constraint might have been expected to worsen predicted thermochemical properties, but in fact they are improved over those of the Perdew-Burke-Ernzerhof GGA, which has nearly the same correlation part. MVS exchange is however radically different from that of other GGAs and meta-GGAs. Its exchange enhancement factor has a very strong dependence upon the orbital kinetic energy density, which permits accurate energies even with the drastically tightened bound. When this nonempirical MVS meta-GGA is hybridized with 25% of exact exchange, the resulting global hybrid gives excellent predictions for atomization energies, reaction barriers, and weak interactions of molecules.

Integrity modelling of tropospheric delay models

NASA Astrophysics Data System (ADS)

Rózsa, Szabolcs; Bastiaan Ober, Pieter; Mile, Máté; Ambrus, Bence; Juni, Ildikó

2017-04-01

The effect of the neutral atmosphere on signal propagation is routinely estimated by various tropospheric delay models in satellite navigation. Although numerous studies can be found in the literature investigating the accuracy of these models, for safety-of-life applications it is crucial to study and model the worst case performance of these models using very low recurrence frequencies. The main objective of the INTegrity of TROpospheric models (INTRO) project funded by the ESA PECS programme is to establish a model (or models) of the residual error of existing tropospheric delay models for safety-of-life applications. Such models are required to overbound rare tropospheric delays and should thus include the tails of the error distributions. Their use should lead to safe error bounds on the user position and should allow computation of protection levels for the horizontal and vertical position errors. The current tropospheric model from the RTCA SBAS Minimal Operational Standards has an associated residual error that equals 0.12 meters in the vertical direction. This value is derived by simply extrapolating the observed distribution of the residuals into the tail (where no data is present) and then taking the point where the cumulative distribution has an exceedance level would be 10-7.While the resulting standard deviation is much higher than the estimated standard variance that best fits the data (0.05 meters), it surely is conservative for most applications. In the context of the INTRO project some widely used and newly developed tropospheric delay models (e.g. RTCA MOPS, ESA GALTROPO and GPT2W) were tested using 16 years of daily ERA-INTERIM Reanalysis numerical weather model data and the raytracing technique. The results showed that the performance of some of the widely applied models have a clear seasonal dependency and it is also affected by a geographical position. In order to provide a more realistic, but still conservative estimation of the residual error of tropospheric delays, the mathematical formulation of the overbounding models are currently under development. This study introduces the main findings of the residual error analysis of the studied tropospheric delay models, and discusses the preliminary analysis of the integrity model development for safety-of-life applications.

Thermodynamic approach to oxygen delivery in vivo by natural and artificial oxygen carriers.

PubMed

Bucci, Enrico

2009-06-01

Oxygen is a toxic gas, still indispensable to aerobic life. This paper explores how normal physiology uses the physico-chemical and thermodynamic characteristics of oxygen for transforming a toxic gas into a non toxic indispensable metabolite. Plasma oxygen concentration is in the range of 10(-5) M, insufficient to sustain metabolism. Oxygen carriers, present in blood, release oxygen into plasma, thereby replacing consumed oxygen and buffering PO(2) near their P(50). They are the natural cell-bound carriers, like hemoglobin inside red cells, myoglobin inside myocytes, and artificial cell-free hemoglobin-based oxygen carriers (HBOC) dissolved in plasma. Metabolic oxygen replacement can be defined as cell-bound and cell-free delivery. Cell-bound delivery is retarded by the slow diffusion of oxygen in plasma and interstitial fluids. The 40% hematocrit of normal blood compensates for the delay, coping with the fast oxygen consumption by mitochondria. Facilitated oxygen diffusion by HBOCs corrects for the slow diffusion, making cell-free delivery relatively independent from P(50). At all oxygen affinities, HBOCs produce hyperoxygenations that are compensated by vasoconstrictions. There is a strict direct correlation between the rate of oxygen replacement and hemoglobin content of blood. The free energy loss of the gradient adds a relevant regulation of tissues oxygenation. Oxygen is retained intravascularly by the limited permeability to gases of vessel walls.

Immunopathology of experimental Chagas' disease: binding of T cells to Trypanosoma cruzi-infected heart tissue.

PubMed Central

Mortatti, R C; Maia, L C; de Oliveira, A V; Munk, M E

1990-01-01

The immunopathology of Chagas' disease was studied in the experimental model of chronic infection in C57BL/10JT or mice. Sublethal infection with Trypanosoma cruzi, Y strain, induced specific antibodies and a delayed hypersensitivity response to parasite antigens. Mice developed chronic chagasic myocarditis but not skeletal muscle myositis. Binding of T cells to infected heart tissue was investigated during short-term cocultivation of lymphocytes with heart cryostat sections. T cells from infected mice and from normal controls bound equally to myocardium and liver sections from both infected and normal mice. A search in depth was attempted with cells heavily tagged with 99mTc. Labeled T cells from chagasic mice bound to both normal and infected myocardium slices. 99mTc-labeled T cells from controls gave the same binding values. Glass-adherent spleen cells behaved identically to T cells. Prior treatment of the tissue with serum from chronically infected mice did not increase the number of binding cells. Peritoneal macrophages tagged with 99mTc-sulfur colloid also bound to infected myocardium slices. The binding of macrophages was not changed by pretreatment of infected tissue with anti-T, cruzi antibodies. In short, this work did not detect any population of T cells or macrophages which could bind specifically to infected heart tissue to initiate an autoreactive process. Images PMID:2228230

Mechanism of the Exchange Reaction in HRAS from Multiscale Modeling

PubMed Central

Kapoor, Abhijeet; Travesset, Alex

2014-01-01

HRAS regulates cell growth promoting signaling processes by cycling between active (GTP-bound) and inactive (GDP-bound) states. Understanding the transition mechanism is central for the design of small molecules to inhibit the formation of RAS-driven tumors. Using a multiscale approach involving coarse-grained (CG) simulations, all-atom classical molecular dynamics (CMD; total of 3.02 µs), and steered molecular dynamics (SMD) in combination with Principal Component Analysis (PCA), we identified the structural features that determine the nucleotide (GDP) exchange reaction. We show that weakening the coupling between the SwitchI (residues 25–40) and SwitchII (residues 59–75) accelerates the opening of SwitchI; however, an open conformation of SwitchI is unstable in the absence of guanine nucleotide exchange factors (GEFs) and rises up towards the bound nucleotide to close the nucleotide pocket. Both I21 and Y32, play a crucial role in SwitchI transition. We show that an open SwitchI conformation is not necessary for GDP destabilization but is required for GDP/Mg escape from the HRAS. Further, we present the first simulation study showing displacement of GDP/Mg away from the nucleotide pocket. Both SwitchI and SwitchII, delays the escape of displaced GDP/Mg in the absence of GEF. Based on these results, a model for the mechanism of GEF in accelerating the exchange process is hypothesized. PMID:25272152

A Distribution-Free Description of Fragmentation by Blasting Based on Dimensional Analysis

NASA Astrophysics Data System (ADS)

Sanchidrián, José A.; Ouchterlony, Finn

2017-04-01

A model for fragmentation in bench blasting is developed from dimensional analysis adapted from asteroid collision theory, to which two factors have been added: one describing the discontinuities spacing and orientation and another the delay between successive contiguous shots. The formulae are calibrated by nonlinear fits to 169 bench blasts in different sites and rock types, bench geometries and delay times, for which the blast design data and the size distributions of the muckpile obtained by sieving were available. Percentile sizes of the fragments distribution are obtained as the product of a rock mass structural factor, a rock strength-to-explosive energy ratio, a bench shape factor, a scale factor or characteristic size and a function of the in-row delay. The rock structure is described by means of the joints' mean spacing and orientation with respect to the free face. The strength property chosen is the strain energy at rupture that, together with the explosive energy density, forms a combined rock strength/explosive energy factor. The model is applicable from 5 to 100 percentile sizes, with all parameters determined from the fits significant to a 0.05 level. The expected error of the prediction is below 25% at any percentile. These errors are half to one-third of the errors expected with the best prediction models available to date.

Is Parenting Associated with Teenagers' Early Sexual Risk-Taking, Autonomy And Relationship with Sexual Partners?

PubMed Central

Parkes, Alison; Henderson, Marion; Wight, Daniel; Nixon, Catherine

2011-01-01

CONTEXT: Extensive research has explored the relationship between parenting and teenagers’ sexual risk-taking. Whether parenting is associated with wider aspects of teenagers’ capacity to form satisfying sexual relationships is unknown. METHODS: Self-reported data were collected in 2007 from 1,854 students, whose average age was 15.5 years, in central Scotland. Multivariate analyses examined associations between parenting processes and sexual outcomes (delayed first intercourse, condom use and several measures reflecting the context or anticipated context of first sex). RESULTS: Parental supportiveness was positively associated with all outcomes (betas, 0.1–0.4), and parental values restricting intercourse were positively associated with all outcomes except condom use (0.1–0.5). Parental monitoring was associated only with delayed intercourse (0.2) and condom use (0.2); parental rules about TV content were associated with delayed intercourse (0.7) and expecting sex in a relationship, rather than casually (0.8). Frequency of parental communication about sex and parental values endorsing contraceptive use were negatively associated with teenagers’ delayed intercourse (–0.5 and –0.3, respectively), and parents’ contraceptive values were negatively associated with teenagers’ expecting sex in a relationship (–0.5). Associations were partly mediated by teenagers’ attitudes, including value placed on having sex in a relationship. CONCLUSIONS: Parents may develop teenagers’ capacity for positive and safe early sex by promoting skills and values that build autonomy and encourage sex only within a relationship. Interventions should promote supportive parenting and transmission of values, avoid mixed messages about abstinence and contraception, and acknowledge that teenagers may learn more indirectly than directly from parents about sex. PMID:21388503

Dread and the disvalue of future pain.

PubMed

Story, Giles W; Vlaev, Ivaylo; Seymour, Ben; Winston, Joel S; Darzi, Ara; Dolan, Raymond J

2013-01-01

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as 'dread'. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice.

H0LiCOW - I. H0 Lenses in COSMOGRAIL's Wellspring: program overview

NASA Astrophysics Data System (ADS)

Suyu, S. H.; Bonvin, V.; Courbin, F.; Fassnacht, C. D.; Rusu, C. E.; Sluse, D.; Treu, T.; Wong, K. C.; Auger, M. W.; Ding, X.; Hilbert, S.; Marshall, P. J.; Rumbaugh, N.; Sonnenfeld, A.; Tewes, M.; Tihhonova, O.; Agnello, A.; Blandford, R. D.; Chen, G. C.-F.; Collett, T.; Koopmans, L. V. E.; Liao, K.; Meylan, G.; Spiniello, C.

2017-07-01

Strong gravitational lens systems with time delays between the multiple images allow measurements of time-delay distances, which are primarily sensitive to the Hubble constant that is key to probing dark energy, neutrino physics and the spatial curvature of the Universe, as well as discovering new physics. We present H0LiCOW (H0 Lenses in COSMOGRAIL's Wellspring), a program that aims to measure H0 with <3.5 per cent uncertainty from five lens systems (B1608+656, RXJ1131-1231, HE 0435-1223, WFI2033-4723 and HE 1104-1805). We have been acquiring (1) time delays through COSMOGRAIL and Very Large Array monitoring, (2) high-resolution Hubble Space Telescope imaging for the lens mass modelling, (3) wide-field imaging and spectroscopy to characterize the lens environment and (4) moderate-resolution spectroscopy to obtain the stellar velocity dispersion of the lenses for mass modelling. In cosmological models with one-parameter extension to flat Λ cold dark matter, we expect to measure H0 to <3.5 per cent in most models, spatial curvature Ωk to 0.004, w to 0.14 and the effective number of neutrino species to 0.2 (1σ uncertainties) when combined with current cosmic microwave background (CMB) experiments. These are, respectively, a factor of ˜15, ˜2 and ˜1.5 tighter than CMB alone. Our data set will further enable us to study the stellar initial mass function of the lens galaxies, and the co-evolution of supermassive black holes and their host galaxies. This program will provide a foundation for extracting cosmological distances from the hundreds of time-delay lenses that are expected to be discovered in current and future surveys.

Dread and the Disvalue of Future Pain

PubMed Central

Story, Giles W.; Vlaev, Ivaylo; Seymour, Ben; Winston, Joel S.; Darzi, Ara; Dolan, Raymond J.

2013-01-01

Standard theories of decision-making involving delayed outcomes predict that people should defer a punishment, whilst advancing a reward. In some cases, such as pain, people seem to prefer to expedite punishment, implying that its anticipation carries a cost, often conceptualized as ‘dread’. Despite empirical support for the existence of dread, whether and how it depends on prospective delay is unknown. Furthermore, it is unclear whether dread represents a stable component of value, or is modulated by biases such as framing effects. Here, we examine choices made between different numbers of painful shocks to be delivered faithfully at different time points up to 15 minutes in the future, as well as choices between hypothetical painful dental appointments at time points of up to approximately eight months in the future, to test alternative models for how future pain is disvalued. We show that future pain initially becomes increasingly aversive with increasing delay, but does so at a decreasing rate. This is consistent with a value model in which moment-by-moment dread increases up to the time of expected pain, such that dread becomes equivalent to the discounted expectation of pain. For a minority of individuals pain has maximum negative value at intermediate delay, suggesting that the dread function may itself be prospectively discounted in time. Framing an outcome as relief reduces the overall preference to expedite pain, which can be parameterized by reducing the rate of the dread-discounting function. Our data support an account of disvaluation for primary punishments such as pain, which differs fundamentally from existing models applied to financial punishments, in which dread exerts a powerful but time-dependent influence over choice. PMID:24277999

Energy latency tradeoffs for medium access and sleep scheduling in wireless sensor networks

NASA Astrophysics Data System (ADS)

Gang, Lu

Wireless sensor networks are expected to be used in a wide range of applications from environment monitoring to event detection. The key challenge is to provide energy efficient communication; however, latency remains an important concern for many applications that require fast response. The central thesis of this work is that energy efficient medium access and sleep scheduling mechanisms can be designed without necessarily sacrificing application-specific latency performance. We validate this thesis through results from four case studies that cover various aspects of medium access and sleep scheduling design in wireless sensor networks. Our first effort, DMAC, is to design an adaptive low latency and energy efficient MAC for data gathering to reduce the sleep latency. We propose staggered schedule, duty cycle adaptation, data prediction and the use of more-to-send packets to enable seamless packet forwarding under varying traffic load and channel contentions. Simulation and experimental results show significant energy savings and latency reduction while ensuring high data reliability. The second research effort, DESS, investigates the problem of designing sleep schedules in arbitrary network communication topologies to minimize the worst case end-to-end latency (referred to as delay diameter). We develop a novel graph-theoretical formulation, derive and analyze optimal solutions for the tree and ring topologies and heuristics for arbitrary topologies. The third study addresses the problem of minimum latency joint scheduling and routing (MLSR). By constructing a novel delay graph, the optimal joint scheduling and routing can be solved by M node-disjoint paths algorithm under multiple channel model. We further extended the algorithm to handle dynamic traffic changes and topology changes. A heuristic solution is proposed for MLSR under single channel interference. In the fourth study, EEJSPC, we first formulate a fundamental optimization problem that provides tunable energy-latency-throughput tradeoffs with joint scheduling and power control and present both exponential and polynomial complexity solutions. Then we investigate the problem of minimizing total transmission energy while satisfying transmission requests within a latency bound, and present an iterative approach which converges rapidly to the optimal parameter settings.

Exact results for the finite time thermodynamic uncertainty relation

NASA Astrophysics Data System (ADS)

Manikandan, Sreekanth K.; Krishnamurthy, Supriya

2018-03-01

We obtain exact results for the recently discovered finite-time thermodynamic uncertainty relation, for the dissipated work W d , in a stochastically driven system with non-Gaussian work statistics, both in the steady state and transient regimes, by obtaining exact expressions for any moment of W d at arbitrary times. The uncertainty function (the Fano factor of W d ) is bounded from below by 2k_BT as expected, for all times τ, in both steady state and transient regimes. The lower bound is reached at τ=0 as well as when certain system parameters vanish (corresponding to an equilibrium state). Surprisingly, we find that the uncertainty function also reaches a constant value at large τ for all the cases we have looked at. For a system starting and remaining in steady state, the uncertainty function increases monotonically, as a function of τ as well as other system parameters, implying that the large τ value is also an upper bound. For the same system in the transient regime, however, we find that the uncertainty function can have a local minimum at an accessible time τm , for a range of parameter values. The large τ value for the uncertainty function is hence not a bound in this case. The non-monotonicity suggests, rather counter-intuitively, that there might be an optimal time for the working of microscopic machines, as well as an optimal configuration in the phase space of parameter values. Our solutions show that the ratios of higher moments of the dissipated work are also bounded from below by 2k_BT . For another model, also solvable by our methods, which never reaches a steady state, the uncertainty function, is in some cases, bounded from below by a value less than 2k_BT .

Bound Magnon Dominance of the Magnetic Susceptibility of the One-Dimensional Heisenberg Spin One-Half Ferromagnet Cyclohexylammonium Trichlorocuprate

NASA Astrophysics Data System (ADS)

Haines, Donald Noble

1987-09-01

This study is an experimental investigation of the differential magnetic susceptibility of the spin one -half, one-dimensional, Ising-Heisenberg ferromagnet (S = 1over 2,1d,HIF). Recent theoretical work predicts the existence of magnon bound states in this model system, and that these bound spin wave states dominate its thermodynamic properties. Further, the theories indicate that classical linearized spin wave theory fails completely in such systems, and may also be intrinsically incorrect in certain higher dimensional systems. The purpose of this research is to confirm the existence of bound magnons in the S = 1over 2,1d,HIF for the nearly Heisenberg case, and demonstrate the dominance of the bound states over the spin wave states in determining thermodynamic behavior. A preliminary numerical study was performed to determine the ranges of magnetic field and temperature at which bound magnons might be expected to make a significant contribution to the magnetic susceptibility and specific heat of the S = 1over 2,1d,HIF. It was found that bound magnons dominate at low and high fields, and spin waves dominate at intermediate fields. For anisotropies less than 2% bound magnons dominate the low temperature regime for all fields. To test the theoretical predictions cyclohexylammonium trichlorocuprate(II) (CHAC) was chosen as a model S = 1over 2,1d,HIF compound for experimental study. The differential susceptibility of a powder sample of CHAC was measured as a function of temperature in fields of 0, 1, 2, and 3T. The temperature range for these studies was 4.2K to 40K. Susceptibility measurements were performed using an ac mutual inductance bridge which employs a SQUID (Superconducting Quantum Interference Device) as a null detector. The design, calibration, and operation of this instrument are described. Data from the experiments compare favorably with the theoretical predictions, confirming the existence of bound magnons in the nearly Heisenberg S = 1over 2,1d,HIF. Further, the experimental results clearly show that bound magnons are the dominant excitation determining the susceptibility for all fields and temperatures studied. Spin wave theory cannot describe the data for any values of the adjustable parameters.

Robust optimization for nonlinear time-delay dynamical system of dha regulon with cost sensitivity constraint in batch culture

NASA Astrophysics Data System (ADS)

Yuan, Jinlong; Zhang, Xu; Liu, Chongyang; Chang, Liang; Xie, Jun; Feng, Enmin; Yin, Hongchao; Xiu, Zhilong

2016-09-01

Time-delay dynamical systems, which depend on both the current state of the system and the state at delayed times, have been an active area of research in many real-world applications. In this paper, we consider a nonlinear time-delay dynamical system of dha-regulonwith unknown time-delays in batch culture of glycerol bioconversion to 1,3-propanediol induced by Klebsiella pneumonia. Some important properties and strong positive invariance are discussed. Because of the difficulty in accurately measuring the concentrations of intracellular substances and the absence of equilibrium points for the time-delay system, a quantitative biological robustness for the concentrations of intracellular substances is defined by penalizing a weighted sum of the expectation and variance of the relative deviation between system outputs before and after the time-delays are perturbed. Our goal is to determine optimal values of the time-delays. To this end, we formulate an optimization problem in which the time delays are decision variables and the cost function is to minimize the biological robustness. This optimization problem is subject to the time-delay system, parameter constraints, continuous state inequality constraints for ensuring that the concentrations of extracellular and intracellular substances lie within specified limits, a quality constraint to reflect operational requirements and a cost sensitivity constraint for ensuring that an acceptable level of the system performance is achieved. It is approximated as a sequence of nonlinear programming sub-problems through the application of constraint transcription and local smoothing approximation techniques. Due to the highly complex nature of this optimization problem, the computational cost is high. Thus, a parallel algorithm is proposed to solve these nonlinear programming sub-problems based on the filled function method. Finally, it is observed that the obtained optimal estimates for the time-delays are highly satisfactory via numerical simulations.

Prolonged longevity of hypopituitary dwarf mice.

PubMed

Bartke, A; Brown-Borg, H; Mattison, J; Kinney, B; Hauck, S; Wright, C

2001-01-01

In two types of mutant dwarf mice, congenital deficiencies in pituitary function are associated with remarkably increased life expectancy. In this review, we will describe the key phenotypic characteristics of these animals, the evidence that they exhibit delayed aging, and the mechanisms that are suspected to account for their prolonged longevity.

Academic Procrastination in Linking Motivation and Achievement-Related Behaviours: A Perspective of Expectancy-Value Theory

ERIC Educational Resources Information Center

Wu, Fan; Fan, Weihua

2017-01-01

The objective of the present study was to investigate the relationships among college students' achievement motivation (subjective task value and academic self-efficacy), academic procrastination (delay and missing deadlines) and achievement-related behaviours (effort and persistence). More specifically, the study investigated the mediating role…

33 CFR 230.25 - Environmental review and consultation requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Principles and Guidelines for Water and Related Land Resources Implementation Studies. Reviews and... of the ongoing studies are not expected to materially affect the decision on the proposed action, the filing of the final EIS need not be delayed. (b) Executive Order 12114, Environmental Effects Abroad of...

33 CFR 230.25 - Environmental review and consultation requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Principles and Guidelines for Water and Related Land Resources Implementation Studies. Reviews and... of the ongoing studies are not expected to materially affect the decision on the proposed action, the filing of the final EIS need not be delayed. (b) Executive Order 12114, Environmental Effects Abroad of...

33 CFR 230.25 - Environmental review and consultation requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Principles and Guidelines for Water and Related Land Resources Implementation Studies. Reviews and... of the ongoing studies are not expected to materially affect the decision on the proposed action, the filing of the final EIS need not be delayed. (b) Executive Order 12114, Environmental Effects Abroad of...

33 CFR 230.25 - Environmental review and consultation requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Principles and Guidelines for Water and Related Land Resources Implementation Studies. Reviews and... of the ongoing studies are not expected to materially affect the decision on the proposed action, the filing of the final EIS need not be delayed. (b) Executive Order 12114, Environmental Effects Abroad of...

33 CFR 230.25 - Environmental review and consultation requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Principles and Guidelines for Water and Related Land Resources Implementation Studies. Reviews and... of the ongoing studies are not expected to materially affect the decision on the proposed action, the filing of the final EIS need not be delayed. (b) Executive Order 12114, Environmental Effects Abroad of...

Effect of the antitumoral alkylating agent 3-bromopyruvate on mitochondrial respiration: role of mitochondrially bound hexokinase.

PubMed

Rodrigues-Ferreira, Clara; da Silva, Ana Paula Pereira; Galina, Antonio

2012-02-01

The alkylating agent 3-Bromopyruvate (3-BrPA) has been used as an anti-tumoral drug due to its anti-proliferative property in hepatomas cells. This propriety is believed to disturb glycolysis and respiration, which leads to a decreased rate of ATP synthesis. In this study, we evaluated the effects of the alkylating agent 3-BrPA on the respiratory states and the metabolic steps of the mitochondria of mice liver, brain and in human hepatocarcinoma cell line HepG2. The mitochondrial membrane potential (ΔΨ(m)), O(2) consumption and dehydrogenase activities were rapidly dissipated/or inhibited by 3-BrPA in respiration medium containing ADP and succinate as respiratory substrate. 3-BrPA inhibition was reverted by reduced glutathione (GSH). Respiration induced by yeast soluble hexokinase (HK) was rapidly inhibited by 3-BrPA. Similar results were observed using mice brain mitochondria that present HK naturally bound to the outer mitochondrial membrane. When the adenine nucleotide transporter (ANT) was blocked by the carboxyatractiloside, the 3-BrPA effect was significantly delayed. In permeabilized human hepatoma HepG2 cells that present HK type II bound to mitochondria (mt-HK II), the inhibiting effect occurred faster when the endogenous HK activity was activated by 2-deoxyglucose (2-DOG). Inhibition of mt-HK II by glucose-6-phosphate retards the mitochondria to react with 3-BrPA. The HK activities recovered in HepG2 cells treated or not with 3-BrPA were practically the same. These results suggest that mitochondrially bound HK supporting the ADP/ATP exchange activity levels facilitates the 3-BrPA inhibition reaction in tumors mitochondria by a proton motive force-dependent dynamic equilibrium between sensitive and less sensitive SDH in the electron transport system.

EGF receptor lysosomal degradation is delayed in the cells stimulated with EGF-Quantum dot bioconjugate but earlier key events of endocytic degradative pathway are similar to that of native EGF

PubMed Central

Leontieva, Ekaterina A.; Kornilova, Elena S.

2017-01-01

Quantum dots (QDs) complexed to ligands recognizing surface receptors undergoing internalization are an attractive tool for live cell imaging of ligand-receptor complexes behavior and for specific tracking of the cells of interest. However, conjugation of quasi-multivalent large QD-particle to monovalent small growth factors like EGF that bound their tyrosine-kinase receptors may affect key endocytic events tightly bound to signaling. Here, by means of confocal microscopy we have addressed the key endocytic events of lysosomal degradative pathway stimulated by native EGF or EGF-QD bioconjugate. We have demonstrated that the decrease in endosome number, increase in mean endosome integrated density and the pattern of EEA1 co-localization with EGF-EGFR complexes at early stages of endocytosis were similar for the both native and QD-conjugated ligands. In both cases enlarged hollow endosomes appeared after wortmannin treatment. This indicates that early endosomal fusions and their maturation proceed similar for both ligands. EGF-QD and native EGF similarly accumulated in juxtanuclear region, and live cell imaging of endosome motion revealed the behavior described elsewhere for microtubule-facilitated motility. Finally, EGF-QD and the receptor were found in lysosomes. However, degradation of receptor part of QD-EGF-EGFR-complex was delayed compared to native EGF, but not inhibited, while QDs fluorescence was detected in lysosomes even after 24 hours. Importantly, in HeLa and A549 cells the both ligands behaved similarly. We conclude that during endocytosis EGF-QD behaves as a neutral marker for degradative pathway up to lysosomal stage and can also be used as a long-term cell marker. PMID:28574831

Dynamic Fatigue of ULE Glass

NASA Technical Reports Server (NTRS)

Tucker, Dennis S.; Nettles, Alan T.; Brantley, Lott W. (Technical Monitor)

2001-01-01

Ultra Low Expansion (ULE) glass is used in a number of applications which require a low thermal expansion coefficient. One such application is telescope mirror elements. An allowable stress can be calculated for this material based upon modulus of rupture data; however, this does not take into account the problem of delayed failure. Delayed failure, due to stress corrosion can significantly shorten the lifetime of a glass article. Knowledge of the factors governing the rate of subcritical flaw growth in a given environment enables the development of relations between lifetime, applied stress and failure probability for the material under study. Dynamic fatigue is one method of obtaining the necessary information to develop these relationships. In this study, the dynamic fatigue method was used to construct time-to-failure diagrams for both 230/270 ground and optically polished samples. The grinding and polishing process reduces the surface flaw size and subsurface damage, and relieves residual stress by removing materials with successively smaller grinding media. This resulted in an increase in the strength of the optic during the grinding and polishing sequence. There was also an increase in the lifetime due to grinding and polishing. It was found that using the fatigue parameters determined from the 230/270 grit surface are not significantly different from the optically polished values. Although the lower bound of the polished samples is more conservative, neither time-to-failure curves lie beyond the upper or lower bound of the confidence limits. Therefore, designers preferring conservative limits could use samples without residual stress present (polished samples) to determine the fatigue parameters and inert Weibull parameters from samples with the service condition surface, to determine time-to-failure of the optical element.