A feedback control model for network flow with multiple pure time delays

Science.gov (United States)

Press, J.

1972-01-01

A control model describing a network flow hindered by multiple pure time (or transport) delays is formulated. Feedbacks connect each desired output with a single control sector situated at the origin. The dynamic formulation invokes the use of differential difference equations. This causes the characteristic equation of the model to consist of transcendental functions instead of a common algebraic polynomial. A general graphical criterion is developed to evaluate the stability of such a problem. A digital computer simulation confirms the validity of such criterion. An optimal decision making process with multiple delays is presented.

Flow information on organizational perspective

Directory of Open Access Journals (Sweden)

Danielly Oliveira Inomata

2015-09-01

Full Text Available Introduction: Information flows are vital for the support of processes, decision making and product development in organizations. Objective: To show and describe models of information flows found in the literature and disseminated in Information Science, highlighting the stages, contexts and key outcomes identified. Methodology: Exploratory Search, through the following criteria for the selection of the models: a presentation of a schematic model; b description of the steps that make up the flow. Results: eight models are detailed, which reproduce efficiently the process of information management based on information flows. The models have similar features, but have specific biases, on communication, information management or at the cognitive level. We identified elements and aspects that influence the flow of information. Conclusions: In the organizational context, information value adding should be aligned with the goals of the organization. The study of flows allows characterizing a lean and simple process, from the identification of its elements, and of humans as artifacts of knowledge and as part of this process.

On mill flow rate and fineness control in cement grinding circuits: instability and delayed measurements

International Nuclear Information System (INIS)

Lepore, R.; Boulvin, M.; Renotte, C.; Remy, M.

1999-01-01

A control structure for the mill flow rate and the product fineness is designed, with the feed flow rate and the classifier characteristic as the manipulated variables. Experimental results from a plant highlight the instability of the grinding circuit. A model previously developed by the authors stresses the major influence of the classifier nonlinearities onto this instability. A cascade control structure has been designed and implemented on site. The measurements of the product fineness, sensitive to material grindability fluctuations, are randomly time-delayed. The control structure uses a fineness estimator based on an adaptive scheme and a time delay compensator. (author)

Estimation of time-delayed mutual information and bias for irregularly and sparsely sampled time-series

International Nuclear Information System (INIS)

Albers, D.J.; Hripcsak, George

2012-01-01

Highlights: ► Time-delayed mutual information for irregularly sampled time-series. ► Estimation bias for the time-delayed mutual information calculation. ► Fast, simple, PDF estimator independent, time-delayed mutual information bias estimate. ► Quantification of data-set-size limits of the time-delayed mutual calculation. - Abstract: A method to estimate the time-dependent correlation via an empirical bias estimate of the time-delayed mutual information for a time-series is proposed. In particular, the bias of the time-delayed mutual information is shown to often be equivalent to the mutual information between two distributions of points from the same system separated by infinite time. Thus intuitively, estimation of the bias is reduced to estimation of the mutual information between distributions of data points separated by large time intervals. The proposed bias estimation techniques are shown to work for Lorenz equations data and glucose time series data of three patients from the Columbia University Medical Center database.

Transcranial magnetic stimulation-induced global propagation of transient phase resetting associated with directional information flow

Directory of Open Access Journals (Sweden)

Masahiro eKawasaki

2014-03-01

Full Text Available Electroencephalogram (EEG phase synchronization analyses can reveal large-scale communication between distant brain areas. However, it is not possible to identify the directional information flow between distant areas using conventional phase synchronization analyses. In the present study, we applied transcranial magnetic stimulation (TMS to the occipital area in subjects who were resting with their eyes closed, and analyzed the spatial propagation of transient TMS-induced phase resetting by using the transfer entropy (TE, to quantify the causal and directional flow of information. The time-frequency EEG analysis indicated that the theta (5 Hz phase locking factor (PLF reached its highest value at the distant area (the motor area in this study, with a time lag that followed the peak of the transient PLF enhancements of the TMS-targeted area at the TMS onset. PPI (phase-preservation index analyses demonstrated significant phase resetting at the TMS-targeted area and distant area. Moreover, the TE from the TMS-targeted area to the distant area increased clearly during the delay that followed TMS onset. Interestingly, the time lags were almost coincident between the PLF and TE results (152 vs. 165 ms, which provides strong evidence that the emergence of the delayed PLF reflects the causal information flow. Such tendencies were observed only in the higher-intensity TMS condition, and not in the lower-intensity or sham TMS conditions. Thus, TMS may manipulate large-scale causal relationships between brain areas in an intensity-dependent manner. We demonstrated that single-pulse TMS modulated global phase dynamics and directional information flow among synchronized brain networks. Therefore, our results suggest that single-pulse TMS can manipulate both incoming and outgoing information in the TMS-targeted area associated with functional changes.

Modelling information flow along the human connectome using maximum flow.

Science.gov (United States)

Lyoo, Youngwook; Kim, Jieun E; Yoon, Sujung

2018-01-01

The human connectome is a complex network that transmits information between interlinked brain regions. Using graph theory, previously well-known network measures of integration between brain regions have been constructed under the key assumption that information flows strictly along the shortest paths possible between two nodes. However, it is now apparent that information does flow through non-shortest paths in many real-world networks such as cellular networks, social networks, and the internet. In the current hypothesis, we present a novel framework using the maximum flow to quantify information flow along all possible paths within the brain, so as to implement an analogy to network traffic. We hypothesize that the connection strengths of brain networks represent a limit on the amount of information that can flow through the connections per unit of time. This allows us to compute the maximum amount of information flow between two brain regions along all possible paths. Using this novel framework of maximum flow, previous network topological measures are expanded to account for information flow through non-shortest paths. The most important advantage of the current approach using maximum flow is that it can integrate the weighted connectivity data in a way that better reflects the real information flow of the brain network. The current framework and its concept regarding maximum flow provides insight on how network structure shapes information flow in contrast to graph theory, and suggests future applications such as investigating structural and functional connectomes at a neuronal level. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bifurcation and stability of an improved time-delayed fluid flow model in internet congestion control

International Nuclear Information System (INIS)

Yu-Liang, Liu; Jie, Zhu; Xiao-Shu, Luo

2009-01-01

Based on the fluid flow time-delayed model proposed by Misra et al in internet congestion control, one modified time-delayed model is presented, where the influence of the communication delay on the router queue length is investigated in detail. The main advantage of the new model is that its stability domain is larger even without an extra controller. By linear stability analysis and numerical simulation, the effectiveness and feasibility of the novel model in internet congestion control are verified

Bifurcation and stability of an improved time-delayed fluid flow model in internet congestion control

Science.gov (United States)

Liu, Yu-Liang; Zhu, Jie; Luo, Xiao-Shu

2009-09-01

Based on the fluid flow time-delayed model proposed by Misra et al in internet congestion control, one modified time-delayed model is presented, where the influence of the communication delay on the router queue length is investigated in detail. The main advantage of the new model is that its stability domain is larger even without an extra controller. By linear stability analysis and numerical simulation, the effectiveness and feasibility of the novel model in internet congestion control are verified.

Impact of delayed information in sub-second complex systems

Science.gov (United States)

Manrique, Pedro D.; Zheng, Minzhang; Johnson Restrepo, D. Dylan; Hui, Pak Ming; Johnson, Neil F.

What happens when you slow down the delivery of information in large-scale complex systems that operate faster than the blink of an eye? This question just adopted immediate commercial, legal and political importance following U.S. regulators' decision to allow an intentional 350 microsecond delay to be added in the ultrafast network of financial exchanges. However there is still no scientific understanding available to policymakers of the potential system-wide impact of such delays. Here we take a first step in addressing this question using a minimal model of a population of competing, heterogeneous, adaptive agents which has previously been shown to produce similar statistical features to real markets. We find that while certain extreme system-level behaviors can be prevented by such delays, the duration of others is increased. This leads to a highly non-trivial relationship between delays and system-wide instabilities which warrants deeper empirical investigation. The generic nature of our model suggests there should be a fairly wide class of complex systems where such delay-driven extreme behaviors can arise, e.g. sub-second delays in brain function possibly impacting individuals' behavior, and sub-second delays in navigational systems potentially impacting the safety of driverless vehicles.

Impact of delayed information in sub-second complex systems

Directory of Open Access Journals (Sweden)

Pedro D. Manrique

Full Text Available What happens when you slow down the delivery of information in large-scale complex systems that operate faster than the blink of an eye? This question just adopted immediate commercial, legal and political importance following U.S. regulators’ decision to allow an intentional 350 microsecond delay to be added in the ultrafast network of financial exchanges. However there is still no scientific understanding available to policymakers of the potential system-wide impact of such delays. Here we take a first step in addressing this question using a minimal model of a population of competing, heterogeneous, adaptive agents which has previously been shown to produce similar statistical features to real markets. We find that while certain extreme system-level behaviors can be prevented by such delays, the duration of others is increased. This leads to a highly non-trivial relationship between delays and system-wide instabilities which warrants deeper empirical investigation. The generic nature of our model suggests there should be a fairly wide class of complex systems where such delay-driven extreme behaviors can arise, e.g. sub-second delays in brain function possibly impacting individuals’ behavior, and sub-second delays in navigational systems potentially impacting the safety of driverless vehicles. Keywords: Ultra-fast networks, Temporal perturbation, Competition, Modeling

Many-to-Many Information Flow Policies

DEFF Research Database (Denmark)

Baldan, Paolo; Beggiato, Alessandro; Lluch Lafuente, Alberto

2017-01-01

Information flow techniques typically classify information according to suitable security levels and enforce policies that are based on binary relations between individual levels, e.g., stating that information is allowed to flow from one level to another. We argue that some information flow...... of competing agencies might agree to disclose their secrets, with individual disclosures being undesired, etc. Motivated by this we propose a simple language for expressing information flow policies where the usual admitted flow relation between individual security levels is replaced by a relation between sets...... of security levels, thus allowing to capture coordinated flows of information. The flow of information is expressed in terms of causal dependencies and the satisfaction of a policy is defined with respect to an event structure that is assumed to capture the causal structure of system computations. We suggest...

Hepatobiliary system functional analysis by blood flow and clearance delay model

International Nuclear Information System (INIS)

Aboltins, A.; Reinholds, E.

2002-01-01

A mathematical model for describing liver uptake-excretion is developed and approved. Model is based on different timing delays in hepatobiliary and blood flow system elements. Series of scintigraphic images with 99m Tc-mebrofenins or 99m Tc-HIDA taken with standard nuclear medicine gamma camera are used as the real data for calculations. The time-activity curves are obtained from many regions of human body - heart, liver, gallbladder, spleen, aorta, vein, etc. Both first pass and dynamic acquisition data are used. Results are calculated using real system parameters and compared to real scintigraphy data. Mathematical simulations are made to show difference of hepatobiliary system function at three main points: normal function, good blood flow with bad hepatic function and bad blood flow with good hepatic function. (authors)

Characterization of water quality among direct and delayed wet -weather flows in an urban combined sewer catchment of Thailand

Directory of Open Access Journals (Sweden)

Anootnara Talkul Kuster

2017-08-01

Full Text Available The purpose of this research was to compare five water quality parameters (BOD, TSS, total zinc, TKN, and fecal coliform in wet-weather flow of a combined sewer catchment against dry-weather flow, while making a distinction between direct and delayed inflow, which has often not been made. Correlations and event mean concentrations (EMCs were also calculated. A total of 38 samples were collected from Khon Kaen’s combined sewer system between March and August 2015. Concentrations in direct inflow of three parameters: total zinc ( x = 0.24 mg/L, IQR = 0.12-0.34, TSS (240 mg/L, 176-356, and BOD (59.7 mg/L, 42.4-77.8 were higher than delayed inflow ( x = 0.04 mg/L, 36 mg/L, and 23.7 mg/L, respectively. Concentrations of delayed inflow were similar to or lower than dry-weather flow. Pollutant concentrations for particulatebased pollutants were much higher during the direct inflow phase of rain events compared to the delayed inflow phase. Dissolved-phased nutrients, however, were not different.

Communication Delays in the Cooperative Control of Wide Area Search Munitions Via Iterative Network Flow

National Research Council Canada - National Science Library

Mitchell, Jason

2003-01-01

.... This model is used to study the effect of communication delays on the performance of an iteractive network flow optimization model that results in a sequence of linear programs for the optimal...

Information flow analysis of interactome networks.

Directory of Open Access Journals (Sweden)

Patrycja Vasilyev Missiuro

2009-04-01

Full Text Available Recent studies of cellular networks have revealed modular organizations of genes and proteins. For example, in interactome networks, a module refers to a group of interacting proteins that form molecular complexes and/or biochemical pathways and together mediate a biological process. However, it is still poorly understood how biological information is transmitted between different modules. We have developed information flow analysis, a new computational approach that identifies proteins central to the transmission of biological information throughout the network. In the information flow analysis, we represent an interactome network as an electrical circuit, where interactions are modeled as resistors and proteins as interconnecting junctions. Construing the propagation of biological signals as flow of electrical current, our method calculates an information flow score for every protein. Unlike previous metrics of network centrality such as degree or betweenness that only consider topological features, our approach incorporates confidence scores of protein-protein interactions and automatically considers all possible paths in a network when evaluating the importance of each protein. We apply our method to the interactome networks of Saccharomyces cerevisiae and Caenorhabditis elegans. We find that the likelihood of observing lethality and pleiotropy when a protein is eliminated is positively correlated with the protein's information flow score. Even among proteins of low degree or low betweenness, high information scores serve as a strong predictor of loss-of-function lethality or pleiotropy. The correlation between information flow scores and phenotypes supports our hypothesis that the proteins of high information flow reside in central positions in interactome networks. We also show that the ranks of information flow scores are more consistent than that of betweenness when a large amount of noisy data is added to an interactome. Finally, we

Information Flow Analysis for VHDL

DEFF Research Database (Denmark)

Tolstrup, Terkel Kristian; Nielson, Flemming; Nielson, Hanne Riis

2005-01-01

We describe a fragment of the hardware description language VHDL that is suitable for implementing the Advanced Encryption Standard algorithm. We then define an Information Flow analysis as required by the international standard Common Criteria. The goal of the analysis is to identify the entire...... information flow through the VHDL program. The result of the analysis is presented as a non-transitive directed graph that connects those nodes (representing either variables or signals) where an information flow might occur. We compare our approach to that of Kemmerer and conclude that our approach yields...

Information flow dynamics in the brain

Science.gov (United States)

Rabinovich, Mikhail I.; Afraimovich, Valentin S.; Bick, Christian; Varona, Pablo

2012-03-01

Timing and dynamics of information in the brain is a hot field in modern neuroscience. The analysis of the temporal evolution of brain information is crucially important for the understanding of higher cognitive mechanisms in normal and pathological states. From the perspective of information dynamics, in this review we discuss working memory capacity, language dynamics, goal-dependent behavior programming and other functions of brain activity. In contrast with the classical description of information theory, which is mostly algebraic, brain flow information dynamics deals with problems such as the stability/instability of information flows, their quality, the timing of sequential processing, the top-down cognitive control of perceptual information, and information creation. In this framework, different types of information flow instabilities correspond to different cognitive disorders. On the other hand, the robustness of cognitive activity is related to the control of the information flow stability. We discuss these problems using both experimental and theoretical approaches, and we argue that brain activity is better understood considering information flows in the phase space of the corresponding dynamical model. In particular, we show how theory helps to understand intriguing experimental results in this matter, and how recent knowledge inspires new theoretical formalisms that can be tested with modern experimental techniques.

Designing reliability information flows

International Nuclear Information System (INIS)

Petkova, Valia T.; Lu Yuan; Ion, Roxana A.; Sander, Peter C.

2005-01-01

It is well-known [Reliab. Eng. Syst. Saf. 75 (2002) 295] that in modern development processes it is essential to have an information flow structure that facilitates fast feedback from product users (customers) to departments at the front end, in particular development and production. As information is only relevant if it is used when taking decisions, this paper presents a guideline for building field feedback information flows that facilitate the decision taking during the product creation and realisation process. The guideline takes into consideration that the type of decisions depends on the span-of-control, therefore following Parsons [Structure and Process in Modern Societies (1990)] the span-of-control is subdivided into the following three levels: strategic, tactic, and executive. The guideline is illustrated with a case in which it is used for analysing the quality of existing field feedback flows

Agricultural informational flow in informal communication networks ...

African Journals Online (AJOL)

Agricultural informational flow in informal communication networks of farmers in Ghana. ... should identify such farmers who can serve as intermediaries between actors to help disseminate information in rural communities. Keywords: key communicators, farmers, rural communities, social networks, extension agents ...

Content dependent information flow control

DEFF Research Database (Denmark)

Nielson, Hanne Riis; Nielson, Flemming

2017-01-01

Information flow control extends access control by not only regulating who is allowed to access what data but also the subsequent use of the data. Applications within communications systems require such information flow control to be dependent on the actual contents of the data. We develop...

Periodic flows to chaos in time-delay systems

CERN Document Server

Luo, Albert C J

2017-01-01

This book for the first time examines periodic motions to chaos in time-delay systems, which exist extensively in engineering. For a long time, the stability of time-delay systems at equilibrium has been of great interest from the Lyapunov theory-based methods, where one cannot achieve the ideal results. Thus, time-delay discretization in time-delay systems was used for the stability of these systems. In this volume, Dr. Luo presents an accurate method based on the finite Fourier series to determine periodic motions in nonlinear time-delay systems. The stability and bifurcation of periodic motions are determined by the time-delayed system of coefficients in the Fourier series and the method for nonlinear time-delay systems is equivalent to the Laplace transformation method for linear time-delay systems. Facilitates discovery of analytical solutions of nonlinear time-delay systems; Illustrates bifurcation trees of periodic motions to chaos; Helps readers identify motion complexity and singularity; Explains pro...

Thermodynamic efficiency of information and heat flow

International Nuclear Information System (INIS)

Allahverdyan, Armen E; Janzing, Dominik; Mahler, Guenter

2009-01-01

A basic task of information processing is information transfer (flow). Here we study a pair of Brownian particles each coupled to a thermal bath at temperatures T 1 and T 2 . The information flow in such a system is defined via the time-shifted mutual information. The information flow nullifies at equilibrium, and its efficiency is defined as the ratio of the flow to the total entropy production in the system. For a stationary state the information flows from higher to lower temperatures, and its efficiency is bounded from above by (max[T 1 ,T 2 ])/(|T 1 −T 2 |). This upper bound is imposed by the second law and it quantifies the thermodynamic cost for information flow in the present class of systems. It can be reached in the adiabatic situation, where the particles have widely different characteristic times. The efficiency of heat flow—defined as the heat flow over the total amount of dissipated heat—is limited from above by the same factor. There is a complementarity between heat and information flow: the set-up which is most efficient for the former is the least efficient for the latter and vice versa. The above bound for the efficiency can be (transiently) overcome in certain non-stationary situations, but the efficiency is still limited from above. We study yet another measure of information processing (transfer entropy) proposed in the literature. Though this measure does not require any thermodynamic cost, the information flow and transfer entropy are shown to be intimately related for stationary states

Photonic single nonlinear-delay dynamical node for information processing

Science.gov (United States)

Ortín, Silvia; San-Martín, Daniel; Pesquera, Luis; Gutiérrez, José Manuel

2012-06-01

An electro-optical system with a delay loop based on semiconductor lasers is investigated for information processing by performing numerical simulations. This system can replace a complex network of many nonlinear elements for the implementation of Reservoir Computing. We show that a single nonlinear-delay dynamical system has the basic properties to perform as reservoir: short-term memory and separation property. The computing performance of this system is evaluated for two prediction tasks: Lorenz chaotic time series and nonlinear auto-regressive moving average (NARMA) model. We sweep the parameters of the system to find the best performance. The results achieved for the Lorenz and the NARMA-10 tasks are comparable to those obtained by other machine learning methods.

Hoare Logic for Disjunctive Information Flow

DEFF Research Database (Denmark)

Nielson, Hanne Riis; Nielson, Flemming; Li, Ximeng

2015-01-01

Information flow control extends access control by not only regulating who is allowed to access what data but also the subsequent use of the data accessed. Applications within communication networks require such information flow control to depend on the actual data. For a concurrent language...... with synchronous communication and separate data domains we develop a Hoare logic for enforcing disjunctive information flow policies. We establish the soundness of the Hoare logic with respect to an operational semantics and illustrate the development on a running example....

75 FR 13238 - Processed Raspberry Promotion, Research, and Information Order; Delay of Referendum

Science.gov (United States)

2010-03-19

... Promotion, Research, and Information Order; Delay of Referendum AGENCY: Agricultural Marketing Service... further modifications to its proposal. FOR FURTHER INFORMATION CONTACT: Kimberly Coy, Marketing Specialist... Part 1208 Administrative practice and procedure, Advertising, Consumer information, Marketing...

Information Flow for Timed Automata

DEFF Research Database (Denmark)

Nielson, Flemming; Nielson, Hanne Riis; Vasilikos, Panagiotis

2017-01-01

One of the key demands of cyberphysical systems is that they meet their safety goals. Timed Automata has established itself as a formalism for modelling and analysing the real-time safety aspects of cyberphysical systems. Increasingly it is also demanded that cyberphysical systems meet a number o...... of security goals for confidentiality and integrity. Information Flow Control is an approach to ensuring that there are no flows of information that violate the stated security policy....

Disabilities Information Flow: A Disabilities Information Management System

Science.gov (United States)

Ling, Bin; Allison, Colin; Nicholl, J. Ross; Moodley, Luke; Roberts, Dave

2006-01-01

The Disabilities Information Flow (DIF) project at the University of St Andrews has sought to provide a means of efficiently managing all student disabilities information within the institution and provide appropriate role-based service interfaces for all staff who need to routinely interact with this information. This paper describes the software…

Determination of relevant neuron-neuron connections for neural prosthetics using time-delayed mutual information: tutorial and preliminary results.

Science.gov (United States)

Taghva, Alexander; Song, Dong; Hampson, Robert E; Deadwyler, Sam A; Berger, Theodore W

2012-12-01

Identification of functional dependence among neurons is a necessary component in both the rational design of neural prostheses as well as in the characterization of network physiology. The objective of this article is to provide a tutorial for neurosurgeons regarding information theory, specifically time-delayed mutual information, and to compare time-delayed mutual information, an information theoretic quantity based on statistical dependence, with cross-correlation, a commonly used metric for this task in a preliminary analysis of rat hippocampal neurons. Spike trains were recorded from rats performing delayed nonmatch-to-sample task using an array of electrodes surgically implanted into the hippocampus of each hemisphere of the brain. In addition, spike train simulations of positively correlated neurons, negatively correlated neurons, and neurons correlated by nonlinear functions were generated. These were evaluated by time-delayed mutual information (MI) and cross-correlation. Application of time-delayed MI to experimental data indicated the optimal bin size for information capture in the CA3-CA1 system was 40 ms, which may provide some insight into the spatiotemporal nature of encoding in the rat hippocampus. On simulated data, time-delayed MI showed peak values at appropriate time lags in positively correlated, negatively correlated, and complexly correlated data. Cross-correlation showed peak and troughs with positively correlated and negatively correlated data, but failed to capture some higher order correlations. Comparison of time-delayed MI to cross-correlation in identification of functionally dependent neurons indicates that the methods are not equivalent. Time-delayed MI appeared to capture some interactions between CA3-CA1 neurons at physiologically plausible time delays missed by cross-correlation. It should be considered as a method for identification of functional dependence between neurons and may be useful in the development of neural

Content analysis in information flows

Energy Technology Data Exchange (ETDEWEB)

Grusho, Alexander A. [Institute of Informatics Problems of Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova str., 44/2, Moscow (Russian Federation); Faculty of Computational Mathematics and Cybernetics, Moscow State University, Moscow (Russian Federation); Grusho, Nick A.; Timonina, Elena E. [Institute of Informatics Problems of Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova str., 44/2, Moscow (Russian Federation)

2016-06-08

The paper deals with architecture of content recognition system. To analyze the problem the stochastic model of content recognition in information flows was built. We proved that under certain conditions it is possible to solve correctly a part of the problem with probability 1, viewing a finite section of the information flow. That means that good architecture consists of two steps. The first step determines correctly certain subsets of contents, while the second step may demand much more time for true decision.

Nested sparse grid collocation method with delay and transformation for subsurface flow and transport problems

Science.gov (United States)

Liao, Qinzhuo; Zhang, Dongxiao; Tchelepi, Hamdi

2017-06-01

In numerical modeling of subsurface flow and transport problems, formation properties may not be deterministically characterized, which leads to uncertainty in simulation results. In this study, we propose a sparse grid collocation method, which adopts nested quadrature rules with delay and transformation to quantify the uncertainty of model solutions. We show that the nested Kronrod-Patterson-Hermite quadrature is more efficient than the unnested Gauss-Hermite quadrature. We compare the convergence rates of various quadrature rules including the domain truncation and domain mapping approaches. To further improve accuracy and efficiency, we present a delayed process in selecting quadrature nodes and a transformed process for approximating unsmooth or discontinuous solutions. The proposed method is tested by an analytical function and in one-dimensional single-phase and two-phase flow problems with different spatial variances and correlation lengths. An additional example is given to demonstrate its applicability to three-dimensional black-oil models. It is found from these examples that the proposed method provides a promising approach for obtaining satisfactory estimation of the solution statistics and is much more efficient than the Monte-Carlo simulations.

On the impact of information delay on location-based relaying: a markov modeling approach

DEFF Research Database (Denmark)

Nielsen, Jimmy Jessen; Olsen, Rasmus Løvenstein; Madsen, Tatiana Kozlova

2012-01-01

For centralized selection of communication relays, the necessary decision information needs to be collected from the mobile nodes by the access point (centralized decision point). In mobile scenarios, the required information collection and forwarding delays will affect the reliability of the col......For centralized selection of communication relays, the necessary decision information needs to be collected from the mobile nodes by the access point (centralized decision point). In mobile scenarios, the required information collection and forwarding delays will affect the reliability...... of the collected information and hence will influence the performance of the relay selection method. This paper analyzes this influence in the decision process for the example of a mobile location-based relay selection approach using a continuous time Markov chain model. The model is used to obtain optimal relay...

Hybrid Information Flow Analysis for Programs with Arrays

Directory of Open Access Journals (Sweden)

Gergö Barany

2016-07-01

Full Text Available Information flow analysis checks whether certain pieces of (confidential data may affect the results of computations in unwanted ways and thus leak information. Dynamic information flow analysis adds instrumentation code to the target software to track flows at run time and raise alarms if a flow policy is violated; hybrid analyses combine this with preliminary static analysis. Using a subset of C as the target language, we extend previous work on hybrid information flow analysis that handled pointers to scalars. Our extended formulation handles arrays, pointers to array elements, and pointer arithmetic. Information flow through arrays of pointers is tracked precisely while arrays of non-pointer types are summarized efficiently. A prototype of our approach is implemented using the Frama-C program analysis and transformation framework. Work on a full machine-checked proof of the correctness of our approach using Isabelle/HOL is well underway; we present the existing parts and sketch the rest of the correctness argument.

A Fault Prognosis Strategy Based on Time-Delayed Digraph Model and Principal Component Analysis

Directory of Open Access Journals (Sweden)

Ningyun Lu

2012-01-01

Full Text Available Because of the interlinking of process equipments in process industry, event information may propagate through the plant and affect a lot of downstream process variables. Specifying the causality and estimating the time delays among process variables are critically important for data-driven fault prognosis. They are not only helpful to find the root cause when a plant-wide disturbance occurs, but to reveal the evolution of an abnormal event propagating through the plant. This paper concerns with the information flow directionality and time-delay estimation problems in process industry and presents an information synchronization technique to assist fault prognosis. Time-delayed mutual information (TDMI is used for both causality analysis and time-delay estimation. To represent causality structure of high-dimensional process variables, a time-delayed signed digraph (TD-SDG model is developed. Then, a general fault prognosis strategy is developed based on the TD-SDG model and principle component analysis (PCA. The proposed method is applied to an air separation unit and has achieved satisfying results in predicting the frequently occurred “nitrogen-block” fault.

Border information flow architecture

Science.gov (United States)

2006-04-01

This brochure describes the Border Information Flow Architecture (BIFA). The Transportation Border Working Group, a bi-national group that works to enhance coordination and planning between the United States and Canada, identified collaboration on th...

Generalized HARQ Protocols with Delayed Channel State Information and Average Latency Constraints

DEFF Research Database (Denmark)

Trillingsgaard, Kasper Fløe; Popovski, Petar

2018-01-01

In many practical wireless systems, the signal-to-interference-and-noise ratio (SINR) that is applicable to a certain transmission, referred to as channel state information (CSI), can only be learned after the transmission has taken place and is thereby delayed (outdated). In such systems, hybrid...... automatic repeat request (HARQ) protocols are often used to achieve high throughput with low latency. This paper put forth the family of expandable message space (EMS) protocols that generalize the HARQ protocol and allow for rate adaptation based on delayed CSI at the transmitter (CSIT). Assuming a block...

Smart grids, information flows and emerging domestic energy practices

International Nuclear Information System (INIS)

Naus, Joeri; Spaargaren, Gert; Vliet, Bas J.M. van; Horst, Hilje M. van der

2014-01-01

Smart energy grids and smart meters are commonly expected to promote more sustainable ways of living. This paper presents a conceptual framework for analysing the different ways in which smart grid developments shape – and are shaped by – the everyday lives of residents. Drawing upon theories of social practices and the concept of informational governance, the framework discerns three categories of ‘information flows’: flows between household-members, flows between households and energy service providers, and flows between local and distant households. Based on interviews with Dutch stakeholders and observations at workshops we examine, for all three information flows, the changes in domestic energy practices and the social relations they help to create. The analysis reveals that new information flows may not produce more sustainable practices in linear and predictable ways. Instead, changes are contextual and emergent. Second, new possibilities for information sharing between households open up a terrain for new practices. Third, information flows affect social relationships in ways as illustrated by the debates on consumer privacy in the Netherlands. An exclusive focus on privacy, however, deviates attention from opportunities for information disclosure by energy providers, and from the significance of transparency issues in redefining relationships both within and between households. - Highlights: • Smart grids generate three key new information flows that affect social relations. • Practice theory can reveal the ways in which households handle/govern information. • Householders show ambivalence about the workings of the different information flows. • Policies should account for the ‘bright’ as well as the ‘dark’ sides of information

Comparing a Shipping Information Pipeline with a Thick Flow and a Thin Flow

NARCIS (Netherlands)

van Engelenburg, S.H.; Janssen, M.F.W.H.A.; Klievink, A.J.; Tan, Y.; Janssen, Marijn; Axelsson, Karin; Glassey, Olivier; Klievink, Bram; Krimmer, Robert; Lindgren, Ida; Parycek, Peter; Scholl, Hans J.; Trutnev, Dmitrii

2017-01-01

Advanced architectures for business-to-government (B2G) information sharing can benefit both businesses and government. An essential choice in the design of such an architecture is whether information is shared using a thick or a thin information flow. In an architecture with a thick flow, all

CPS Transformation of Flow Information, Part II

DEFF Research Database (Denmark)

Damian, D.; Danvy, Olivier

2003-01-01

consider the administrative reductions of a Plotkin-style transformation into Continuation-Passing Style (CPS), and how they affect the result of a constraint-based control-flow analysis and, in particular, the least element in the space of solutions. We show that administrative reductions preserve...... the least solution. Preservation of least solutions solves a problem that was left open in Palsberg and Wand's article ‘CPS Transformation of Flow Information.’ Together, Palsberg and Wand's article and the present article show how to map in linear time the least solution of the flow constraints...... of a program into the least solution of the flow constraints of the CPS counterpart of this program, after administrative reductions. Furthermore, we show how to CPS transform control-flow information in one pass....

Representing delayed force feedback as a combination of current and delayed states.

Science.gov (United States)

Avraham, Guy; Mawase, Firas; Karniel, Amir; Shmuelof, Lior; Donchin, Opher; Mussa-Ivaldi, Ferdinando A; Nisky, Ilana

2017-10-01

To adapt to deterministic force perturbations that depend on the current state of the hand, internal representations are formed to capture the relationships between forces experienced and motion. However, information from multiple modalities travels at different rates, resulting in intermodal delays that require compensation for these internal representations to develop. To understand how these delays are represented by the brain, we presented participants with delayed velocity-dependent force fields, i.e., forces that depend on hand velocity either 70 or 100 ms beforehand. We probed the internal representation of these delayed forces by examining the forces the participants applied to cope with the perturbations. The findings showed that for both delayed forces, the best model of internal representation consisted of a delayed velocity and current position and velocity. We show that participants relied initially on the current state, but with adaptation, the contribution of the delayed representation to adaptation increased. After adaptation, when the participants were asked to make movements with a higher velocity for which they had not previously experienced with the delayed force field, they applied forces that were consistent with current position and velocity as well as delayed velocity representations. This suggests that the sensorimotor system represents delayed force feedback using current and delayed state information and that it uses this representation when generalizing to faster movements. NEW & NOTEWORTHY The brain compensates for forces in the body and the environment to control movements, but it is unclear how it does so given the inherent delays in information transmission and processing. We examined how participants cope with delayed forces that depend on their arm velocity 70 or 100 ms beforehand. After adaptation, participants applied opposing forces that revealed a partially correct representation of the perturbation using the current and the

Inventory model with cash flow oriented and time-dependent holding cost under permissible delay in payments

Directory of Open Access Journals (Sweden)

Tripathi R.P.

2013-01-01

Full Text Available This study develops an inventory model for determining an optimal ordering policy for non-deteriorating items and time-dependent holding cost with delayed payments permitted by the supplier under inflation and time-discounting. The discounted cash flows approach is applied to study the problem analysis. Mathematical models have been derived under two different situations i.e. case I: The permissible delay period is less than cycle time for settling the account and case II: The permissible delay period is greater than or equal to cycle time for settling the account. An algorithm is used to obtain minimum total present value of the costs over the time horizon H. Finally, numerical example and sensitivity analysis demonstrate the applicability of the proposed model. The main purpose of this paper is to investigate the optimal cycle time and optimal payment time for an item so that annual total relevant cost is minimized.

Information Flows? A Critique of Transfer Entropies

Science.gov (United States)

James, Ryan G.; Barnett, Nix; Crutchfield, James P.

2016-06-01

A central task in analyzing complex dynamics is to determine the loci of information storage and the communication topology of information flows within a system. Over the last decade and a half, diagnostics for the latter have come to be dominated by the transfer entropy. Via straightforward examples, we show that it and a derivative quantity, the causation entropy, do not, in fact, quantify the flow of information. At one and the same time they can overestimate flow or underestimate influence. We isolate why this is the case and propose several avenues to alternate measures for information flow. We also address an auxiliary consequence: The proliferation of networks as a now-common theoretical model for large-scale systems, in concert with the use of transferlike entropies, has shoehorned dyadic relationships into our structural interpretation of the organization and behavior of complex systems. This interpretation thus fails to include the effects of polyadic dependencies. The net result is that much of the sophisticated organization of complex systems may go undetected.

Hodge Decomposition of Information Flow on Small-World Networks.

Science.gov (United States)

Haruna, Taichi; Fujiki, Yuuya

2016-01-01

We investigate the influence of the small-world topology on the composition of information flow on networks. By appealing to the combinatorial Hodge theory, we decompose information flow generated by random threshold networks on the Watts-Strogatz model into three components: gradient, harmonic and curl flows. The harmonic and curl flows represent globally circular and locally circular components, respectively. The Watts-Strogatz model bridges the two extreme network topologies, a lattice network and a random network, by a single parameter that is the probability of random rewiring. The small-world topology is realized within a certain range between them. By numerical simulation we found that as networks become more random the ratio of harmonic flow to the total magnitude of information flow increases whereas the ratio of curl flow decreases. Furthermore, both quantities are significantly enhanced from the level when only network structure is considered for the network close to a random network and a lattice network, respectively. Finally, the sum of these two ratios takes its maximum value within the small-world region. These findings suggest that the dynamical information counterpart of global integration and that of local segregation are the harmonic flow and the curl flow, respectively, and that a part of the small-world region is dominated by internal circulation of information flow.

Hodge decomposition of information flow on small-world networks

Directory of Open Access Journals (Sweden)

Taichi Haruna

2016-09-01

Full Text Available We investigate the influence of the small-world topology on the composition of information flow on networks. By appealing to the combinatorial Hodge theory, we decompose information flow generated by random threshold networks on the Watts-Strogatz model into three components: gradient, harmonic and curl flows. The harmonic and curl flows represent globally circular and locally circular components, respectively. The Watts-Strogatz model bridges the two extreme network topologies, a lattice network and a random network, by a single parameter that is the probability of random rewiring. The small-world topology is realized within a certain range between them. By numerical simulation we found that as networks become more random the ratio of harmonic flow to the total magnitude of information flow increases whereas the ratio of curl flow decreases. Furthermore, both quantities are significantly enhanced from the level when only network structure is considered for the network close to a random network and a lattice network, respectively. Finally, the sum of these two ratios takes its maximum value within the small-world region. These findings suggest that the dynamical information counterpart of global integration and that of local segregation are the harmonic flow and the curl flow, respectively, and that a part of the small-world region is dominated by internal circulation of information flow.

Bipartite consensus for multi-agent systems with antagonistic interactions and communication delays

Science.gov (United States)

Guo, Xing; Lu, Jianquan; Alsaedi, Ahmed; Alsaadi, Fuad E.

2018-04-01

This paper studies the consensus problems over signed digraphs with arbitrary finite communication delays. For the considered system, the information flow is directed and only locally delayed information can be used for each node. We derive that bipartite consensus of this system can be realized when the associated signed digraph is strongly connected. Furthermore, for structurally balanced networks, this paper studies the pinning partite consensus for the considered system. we design a pinning scheme to pin any one agent in the signed network, and obtain that the network achieves pinning bipartite consensus with any initial conditions. Finally, two examples are provided to demonstrate the effectiveness of our main results.

Disjunctive Information Flow for Communicating Processes

DEFF Research Database (Denmark)

Li, Ximeng; Nielson, Flemming; Nielson, Hanne Riis

2016-01-01

The security validation of practical computer systems calls for the ability to specify and verify information flow policies that are dependent on data content. Such policies play an important role in concurrent, communicating systems: consider a scenario where messages are sent to different...... processes according to their tagging. We devise a security type system that enforces content-dependent information flow policies in the presence of communication and concurrency. The type system soundly guarantees a compositional noninterference property. All theoretical results have been formally proved...

Flow Effects on the Flammability Diagrams of Solid Fuels: Microgravity Influence on Ignition Delay

Science.gov (United States)

Cordova, J. L.; Walther, D. C.; Fernandez-Pello, A. C.; Steinhaus, T.; Torero, J. L.; Quintere, J. G.; Ross, H. D.

1999-01-01

The possibility of an accidental fire in space-based facilities is a primary concern of space exploration programs. Spacecraft environments generally present low velocity air currents produced by ventilation and heating systems (of the order of 0.1 m/s), and fluctuating oxygen concentrations around that of air due to CO2 removal systems. Recent experiments of flame spread in microgravity show the spread rate to be faster and the limiting oxygen concentration lower than in normal-gravity. To date, there is not a material flammability-testing protocol that specifically addresses issues related to microgravity conditions. The present project (FIST) aims to establish a testing methodology that is suitable for the specific conditions of reduced gravity. The concepts underlying the operation of the LIFT apparatus, ASTM-E 1321-93, have been used to develop the Forced-flow Ignition and flame-Spread Test (FIST). As in the LIFT, the FIST is used to obtain the flammability diagrams of the material, i.e., graphs of ignition delay time and flame spread rate as a function of the externally applied radiant flux, but under forced flow rather than natural convection conditions, and for different oxygen concentrations. Although the flammability diagrams are similar, the flammability properties obtained with the FIST are found to depend on the flow characteristics. A research program is currently underway with the purpose of implementing the FIST as a protocol to characterize the flammability performance of solid materials to be used in microgravity facilities. To this point, tests have been performed with the FIST apparatus in both normal-gravity and microgravity conditions to determine the effects of oxidizer flow characteristics on the flammability diagrams of polymethylmethacrylate (PMMA) fuel samples. The experiments are conducted at reduced gravity in a KC- 135 aircraft following a parabolic flight trajectory that provides up to 25 seconds of low gravity. The objective of the

Consensus of discrete-time multi-agent systems with adversaries and time delays

Science.gov (United States)

Wu, Yiming; He, Xiongxiong; Liu, Shuai; Xie, Lihua

2014-05-01

This paper studies the resilient asymptotic consensus problem for discrete-time multi-agent systems in the presence of adversaries and transmission delays. The network is assumed to have ? loyal agents and ? adversarial agents, and each loyal agent in the network has no knowledge of the network topology other than an upper bound on the number of adversarial agents in its neighborhood. For the considered networked system, only locally delayed information is available for each loyal agent, and also the information flow is directed and a control protocol using only local information is designed to guarantee the realization of consensus with respect to communication graph, which satisfies a featured network robustness. Numerical examples are finally given to demonstrate the effectiveness of theoretical results.

Comparing the effect of temporal delay on the availability of egocentric and allocentric information in visual search.

Science.gov (United States)

Ball, Keira; Birch, Yan; Lane, Alison; Ellison, Amanda; Schenk, Thomas

2017-07-28

Frames of reference play a central role in perceiving an object's location and reaching to pick that object up. It is thought that the ventral stream, believed to subserve vision for perception, utilises allocentric coding, while the dorsal stream, argued to be responsible for vision for action, primarily uses an egocentric reference frame. We have previously shown that egocentric representations can survive a delay; however, it is possible that in comparison to allocentric information, egocentric information decays more rapidly. Here we directly compare the effect of delay on the availability of egocentric and allocentric representations. We used spatial priming in visual search and repeated the location of the target relative to either a landmark in the search array (allocentric condition) or the observer's body (egocentric condition). Three inter-trial intervals created minimum delays between two consecutive trials of 2, 4, or 8seconds. In both conditions, search times to primed locations were faster than search times to un-primed locations. In the egocentric condition the effects were driven by a reduction in search times when egocentric information was repeated, an effect that was observed at all three delays. In the allocentric condition while search times did not change when the allocentric information was repeated, search times to un-primed target locations became slower. We conclude that egocentric representations are not as transient as previously thought but instead this information is still available, and can influence behaviour, after lengthy periods of delay. We also discuss the possible origins of the differences between allocentric and egocentric priming effects. Copyright © 2017 Elsevier B.V. All rights reserved.

Information Flows in Networked Engineering Design Projects

DEFF Research Database (Denmark)

Parraguez, Pedro; Maier, Anja

Complex engineering design projects need to manage simultaneously multiple information flows across design activities associated with different areas of the design process. Previous research on this area has mostly focused on either analysing the “required information flows” through activity...... networks at the project level or in studying the social networks that deliver the “actual information flow”. In this paper we propose and empirically test a model and method that integrates both social and activity networks into one compact representation, allowing to compare actual and required...... information flows between design spaces, and to assess the influence that these misalignments could have on the performance of engineering design projects....

Measurement of 235U content and flow of UF6 using delayed neutrons or gamma rays following induced fission

International Nuclear Information System (INIS)

Stromswold, D.C.; Peurrung, A.J.; Reeder, P.L.; Perkins, R.W.

1996-06-01

Feasibility experiments conducted at Pacific Northwest National Laboratory demonstrate that either delayed neutrons or energetic gamma rays from short-lived fission products can be used to monitor the blending of UF 6 gas streams. A 252 Cf neutron source was used to induce 235 U fission in a sample, and delayed neutrons and gamma rays were measured after the sample moved open-quotes down-stream.close quotes The experiments used a UO 2 powder that was transported down the pipe to simulate the flowing UF 6 gas. Computer modeling and analytic calculation extended the test results to a flowing UF 6 gas system. Neutron or gamma-ray measurements made at two downstream positions can be used to indicate both the 235 U content and UF 6 flow rate. Both the neutron and gamma-ray techniques have the benefits of simplicity and long-term reliability, combined with adequate sensitivity for low-intrusion monitoring of the blending process. Alternatively, measuring the neutron emission rate from (a, n) reactions in the UF 6 provides an approximate measure of the 235 U content without using a neutron source to induce fission

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

Science.gov (United States)

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.

Endogenous Information Flows and the Clustering of Announcements

OpenAIRE

Acharya, Viral; DeMarzo, Peter; Kremer, Ilan

2011-01-01

We consider the release of information by a firm when the manager has discretion regarding the timing of its release. While it is well known that firms appear to delay the release of bad news, we examine how external information about the state of the economy (or the industry) affects this decision. We develop a dynamic model of strategic disclosure in which a firm may privately receive information at a time that is random (and independent of the state of the economy). Because investors are u...

Cross-border flow of health information

DEFF Research Database (Denmark)

Di Iorio, Concetta Tania; Carinci, Fabrizio; Brillante, Massimo

2013-01-01

The EUBIROD project aims to perform a cross-border flow of diabetes information across 19 European countries using the BIRO information system, which embeds privacy principles and data protection mechanisms in its architecture (privacy by design). A specific task of EUBIROD was to investigate...

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

Science.gov (United States)

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

2014-05-28

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2014-05-28

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

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

International Nuclear Information System (INIS)

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

2014-01-01

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

Information flow in the DAMA Project beyond database managers: Information flow managers

Energy Technology Data Exchange (ETDEWEB)

Russell, L. [Argonne National Lab., IL (United States); Wolfson, O.; Yu, C. [Illinois Univ., Chicago, IL (United States)

1996-03-01

To meet the demands of commercial data traffic on the information highway, a new look at managing data is necessary. One projected activity, sharing of point-of-sale information, is being considered in the Demand Activated Manufacturing Project of the American Textile Partnership project. A scenario is examined in which 100,000 retail outlets communicate over a period of days. They provide the latest estimate of demand for sewn products across a chain of 26,000 suppliers through the use of bill-of-materials explosions at four levels of detail. A new paradign the information flow manager, is developed to handle this situation, including the case where members of the supply chain fail to communicate and go out of business. Techniques for approximation are introduced to keep estimates of demand as current as possible.

Developing measures for the evaluation of information flow efficiency in supply chains

Directory of Open Access Journals (Sweden)

Johanna A. Badenhorst

2013-05-01

Full Text Available Member organisations in a supply chain are dependent on each other to provide material, services and information to perform optimally in the supply chain. Efficient, unrestricted information flow is needed in supply chains to function properly. Information flow is thus an element of supply chain management that needs to be managed. Yet, no indication could be found in supply chain management literature of the measurement of information flow efficiency. Hence, the aim of this article is to explore the measurement of information flow efficiency in supply chain management (SCM and exploratively develop possible measures (indicators and associated metrics to measure the efficiency of information flow.In this research the theory of information and related concepts, the basic notions of information systems and the models of business performance measurement were explored. Based on information flow theory and information flow characteristics a research instrument was developed. It was used in a survey to seek inputs from supply chain managers as to the usefulness of characteristics as indicators and metrics for the measurement of information flow efficiency in a supply chain. The main contribution of the study is the development of a conceptual framework of indicators and metrics that may be used to evaluate the efficiency of information flows in supply chains. The results of this study can be used as a basis for further studies to validate the instrument for measuring information flow efficiency and to develop scales to actually measure information flow efficiency.

Guidelines on CV networking information flow optimization for Texas.

Science.gov (United States)

2017-03-01

Recognizing the fundamental role of information flow in future transportation applications, the research team investigated the quality and security of information flow in the connected vehicle (CV) environment. The research team identified key challe...

Journal information flow in nanotechnology

International Nuclear Information System (INIS)

Andrievski, Rostislav A.; Klyuchareva, Svetlana V.

2011-01-01

The nanotechnology development is accompanied by an intensive growth of information flow which is specially noticeable as applied to journal information flow. Now over the world there are the 69 nano-titled journals with the impact factor and/or a settled periodicity as well as the 70 those which lack stability periodicity and are in an organization stage. Only 49 nano-titled have the impact factor with the comparatively high mean value of about 3.44. The domestic nano-titled journals published in Russia, India, China, and other countries are also considered. The attention is taken that in the 2006–2010 period the 95 new nano-titled journals were organized and in 2011 this process is continuing and seems to be the most impressive. Many nano-related journals (including classical physical, chemical and materials science ones) are also described and discussed.

Probabilistic Routing Based on Two-Hop Information in Delay/Disruption Tolerant Networks

Directory of Open Access Journals (Sweden)

Xu Wang

2015-01-01

Full Text Available We investigate an opportunistic routing protocol in delay/disruption tolerant networks (DTNs where the end-to-end path between source and destination nodes may not exist for most of the time. Probabilistic routing protocol using history of encounters and transitivity (PRoPHET is an efficient history-based routing protocol specifically proposed for DTNs, which only utilizes the delivery predictability of one-hop neighbors to make a decision for message forwarding. In order to further improve the message delivery rate and to reduce the average overhead of PRoPHET, in this paper we propose an improved probabilistic routing algorithm (IPRA, where the history information of contacts for the immediate encounter and two-hop neighbors has been jointly used to make an informed decision for message forwarding. Based on the Opportunistic Networking Environment (ONE simulator, the performance of IPRA has been evaluated via extensive simulations. The results show that IPRA can significantly improve the average delivery rate while achieving a better or comparable performance with respect to average overhead, average delay, and total energy consumption compared with the existing algorithms.

Analysis of the brazilian scientific production about information flows

Directory of Open Access Journals (Sweden)

Danielly Oliveira Inomata

2015-07-01

Full Text Available Objective. This paper presents and discuss the concepts, contexts and applications involving information flows in organizations. Method. Systematic review, followed by a bibliometric analysis and system analysis. The systematic review aimed to search for, evaluate and review evidence about the research topic. The systematic review process comprised the following steps: 1 definition of keywords, 2 systematic review, 3 exploration and analysis of articles and 4 comparison and consolidation of results. Results. A bibliometric analysis aimed to provide a statement of the relevance of articles where the authors, dates of publications, citation index, and periodic keywords with higher occurrence. Conclusions. As survey results confirms the emphasis on information featured in the knowledge management process, and advancing years, it seems that the emphasis is on networks, ie, studies are turning to the operationalization and analysis of flows information networks. The literature produced demonstrates the relationship of information flow with its management, applied to different organizational contexts, including showing new trends in information science as the study and analysis of information flow in networks.

Effect of time delay on the upper bound of the time derivative of information entropy in a stochastic dynamical system

International Nuclear Information System (INIS)

Zhang Min-Min; Mei Dong-Cheng; Wang Can-Jun

2011-01-01

The effects of the time delay on the upper bound of the time derivative of information entropy are investigated in a time-delayed dynamical system driven by correlated noise. Using the Markov approximation of the stochastic delay differential equations and the Schwartz inequality principle, we obtain an analytical expression for the upper bound U B (t) of the time derivative of the information entropy. The results show that there is a critical value of τ (delay time), and U B (t) presents opposite behaviours on difference sides of the critical value. For the case of the weak additive noise, τ can induce a reentrance transition. Delay time τ also causes a reversal behaviour in U B (t)-λ plot, where λ denotes the degree of the correlation between the two noises. (general)

Homeland Security and Information Control: A Model of Asymmetric Information Flows.

Science.gov (United States)

Maxwell, Terrence A.

2003-01-01

Summarizes some of the activities the United States government has undertaken to control the dissemination of information since 2001. It also explores, through a conceptual model of information flows, potential impacts and discontinuities between policy purposes and outcomes. (AEF)

Incomplete Information about Social Preferences Explains Equal Division and Delay in Bargaining

Directory of Open Access Journals (Sweden)

Stefan Kohler

2012-09-01

Full Text Available Two deviations of alternating-offer bargaining behavior from economic theory are observed together, yet have been studied separately. Players who could secure themselves a large surplus share if bargainers were purely self-interested incompletely exploit their advantage. Delay in agreement occurs even if all experimentally controlled information is common knowledge. This paper rationalizes both regularities coherently by modeling heterogeneous social preferences, either self-interest or envy, of one bargaining party as private information in a three period game of bargaining and preference screening and signaling.

Information flow in the pharmaceutical supply chain.

Science.gov (United States)

Yousefi, Nazila; Alibabaei, Ahmad

2015-01-01

Managing the supply chain plays an important role in creating competitive advantages for companies. Adequate information flow in supply chain is one of the most important issues in SCM. Therefore, using certain Information Systems can have a significant role in managing and integrating data and information within the supply chain. Pharmaceutical supply chain is more complex than many other supply chains, in the sense that it can affect social and political perspectives. On the other hand, managing the pharmaceutical supply chain is difficult because of its complexity and also government regulations in this field. Although, Iran has progressed a lot in pharmaceutical manufacturing, still there are many unsolved issues in managing the information flow in the pharmaceutical supply chain. In this study, we reviewed the benefits of using different levels of an integrated information system in the supply chain and the possible challenges ahead.

Quantitative Information Flow as Safety and Liveness Hyperproperties

Directory of Open Access Journals (Sweden)

Hirotoshi Yasuoka

2012-07-01

Full Text Available We employ Clarkson and Schneider's "hyperproperties" to classify various verification problems of quantitative information flow. The results of this paper unify and extend the previous results on the hardness of checking and inferring quantitative information flow. In particular, we identify a subclass of liveness hyperproperties, which we call "k-observable hyperproperties", that can be checked relative to a reachability oracle via self composition.

Reward acts as a signal to control delay-period activity in delayed-response tasks.

Science.gov (United States)

Ichihara-Takeda, Satoe; Takeda, Kazuyoshi; Funahashi, Shintaro

2010-03-31

Prefrontal delay-period activity represents a neural mechanism for the active maintenance of information and needs to be controlled by some signal to appropriately operate working memory. To examine whether reward-delivery acts as this signal, the effects of delay-period activity in response to unexpected reward-delivery were examined by analyzing single-neuron activity recorded in the primate dorsolateral prefrontal cortex. Among neurons that showed delay-period activity, 34% showed inhibition of this activity in response to unexpected reward-delivery. The delay-period activity of these neurons was affected by the expectation of reward-delivery. The strength of the reward signal in controlling the delay-period activity is related to the strength of the effect of reward information on the delay-period activity. These results indicate that reward-delivery acts as a signal to control delay-period activity.

Information transmission and signal permutation in active flow networks

Science.gov (United States)

Woodhouse, Francis G.; Fawcett, Joanna B.; Dunkel, Jörn

2018-03-01

Recent experiments show that both natural and artificial microswimmers in narrow channel-like geometries will self-organise to form steady, directed flows. This suggests that networks of flowing active matter could function as novel autonomous microfluidic devices. However, little is known about how information propagates through these far-from-equilibrium systems. Through a mathematical analogy with spin-ice vertex models, we investigate here the input–output characteristics of generic incompressible active flow networks (AFNs). Our analysis shows that information transport through an AFN is inherently different from conventional pressure or voltage driven networks. Active flows on hexagonal arrays preserve input information over longer distances than their passive counterparts and are highly sensitive to bulk topological defects, whose presence can be inferred from marginal input–output distributions alone. This sensitivity further allows controlled permutations on parallel inputs, revealing an unexpected link between active matter and group theory that can guide new microfluidic mixing strategies facilitated by active matter and aid the design of generic autonomous information transport networks.

Mortality in patients with TIMI 3 flow after PCI in relation to time delay to reperfusion.

Science.gov (United States)

Vichova, Teodora; Maly, Marek; Ulman, Jaroslav; Motovska, Zuzana

2016-03-01

Percutaneous coronary intervention (PCI) performed within 12 h from symptom onset enables complete blood flow restoration in infarct-related artery in 90% of patients. Nevertheless, even with complete restoration of epicardial blood flow in culprit vessel (postprocedural Thrombolysis in Myocardial Infarction (TIMI) flow grade 3), myocardial perfusion at tissue level may be insufficient. We hypothesized that the outcome of patients with STEMI/bundle branch block (BBB)-myocardial infarction and post-PCI TIMI 3 flow is related to the time to reperfusion. Observational study based on a retrospective analysis of population of 635 consecutive patients with STEMI/BBB-MI and post-PCI TIMI 3 flow from January 2009 to December 2011 (mean age 63 years, 69.6% males). Mortality of patients was evaluated in relation to the time from symptom onset to reperfusion. A total of 83 patients (13.07%) with postprocedural TIMI 3 flow after PCI had died at 1-year follow-up. Median TD in patients who survived was 3.92 h (iqr 5.43), in patients who died 6.0 h (iqr 11.42), P = 0.004. Multiple logistic regression analysis identified time delay ≥ 9 h as significantly related to 1-year mortality of patients with STEMI/BBB-MI and post-PCI TIMI 3 flow (OR 1.958, P = 0.026). Other significant variables associated with mortality in multivariate regression analysis were: left ventricle ejection fraction 65 years (P 2 (P PCI.

Modeling of information flows in natural gas storage facility

Science.gov (United States)

Ranjbari, Leyla; Bahar, Arifah; Aziz, Zainal Abdul

2013-09-01

The paper considers the natural-gas storage valuation based on the information-based pricing framework of Brody-Hughston-Macrina (BHM). As opposed to many studies which the associated filtration is considered pre-specified, this work tries to construct the filtration in terms of the information provided to the market. The value of the storage is given by the sum of the discounted expectations of the cash flows under risk-neutral measure, conditional to the constructed filtration with the Brownian bridge noise term. In order to model the flow of information about the cash flows, we assume the existence of a fixed pricing kernel with liquid, homogenous and incomplete market without arbitrage.

Information flow in the DAMA project beyond database managers: information flow managers

Science.gov (United States)

Russell, Lucian; Wolfson, Ouri; Yu, Clement

1996-12-01

To meet the demands of commercial data traffic on the information highway, a new look at managing data is necessary. One projected activity, sharing of point of sale information, is being considered in the Demand Activated Manufacturing Project (DAMA) of the American Textile Partnership (AMTEX) project. A scenario is examined in which 100 000 retail outlets communicate over a period of days. They provide the latest estimate of demand for sewn products across a chain of 26 000 suppliers through the use of bill of materials explosions at four levels of detail. Enabling this communication requires an approach that shares common features with both workflows and database management. A new paradigm, the information flow manager, is developed to handle this situation, including the case where members of the supply chain fail to communicate and go out of business. Techniques for approximation are introduced so as to keep estimates of demand as current as possible.

Fine-grained Information Flow for Concurrent Computation

DEFF Research Database (Denmark)

Li, Ximeng

and reference monitors, have been proposed in the context of programming languages and process calculi, to enforce such properties. The most widely used definitions of information flow security are noninterference-like properties. For concurrent systems where processes communicate with each other to accomplish...... computational tasks, fine-grained security policies can be formulated by distinguishing between whether communication can happen, and what is communicated. As the first contribution of this PhD thesis, we formulate a noninterference-like property that takes all combinations of sensitivity levels for “whether...... to a classical one when the two dimensions are intentionally blurred. As the second contribution, we focus on the “what” dimension and further allow the flow policy to vary under different contents stored and communicated. This is the area of content-dependent (or conditional) information flow, which has...

Information Flow Analysis of Level 4 Payload Processing Operations

Science.gov (United States)

Danz, Mary E.

1991-01-01

The Level 4 Mission Sequence Test (MST) was studied to develop strategies and recommendations to facilitate information flow. Recommendations developed as a result of this study include revised format of the Test and Assembly Procedure (TAP) document and a conceptualized software based system to assist in the management of information flow during the MST.

Calculation of vehicle delay at signal-controlled intersections with adaptive traffic control algorithm

Directory of Open Access Journals (Sweden)

Andronov Roman

2018-01-01

Full Text Available By widely introducing information technology tools in the field of traffic control, it is possible to increase the capacity of hubs and reduce vehicle delays. Adaptive traffic light control is one of such tools. Its effectiveness can be assessed through traffic flow simulation. The aim of this study is to create a simulation model of a signal-controlled intersection that can be used to assess the effectiveness of adaptive control in various traffic situations, including the presence or absence of pedestrian traffic through an intersection. The model is based on a numerical experiment conducted using the Monte Carlo method. As a result of the study, vehicle delays, queue length and duration of traffic light cycles are calculated subject to different intensities of incoming traffic flows, and the presence or absence of pedestrian traffic.

Compatibility of Safety Properties and Possibilistic Information Flow Security in MAKS

OpenAIRE

Bauereiss , Thomas; Hutter , Dieter

2014-01-01

Part 6: Information Flow Control; International audience; Motivated by typical security requirements of workflow management systems, we consider the integrated verification of both safety properties (e.g. separation of duty) and information flow security predicates of the MAKS framework (e.g. modeling confidentiality requirements). Due to the refinement paradox, enforcement of safety properties might violate possibilistic information flow properties of a system. We present an approach where s...

UAS Air Traffic Controller Acceptability Study-2: Effects of Communications Delays and Winds in Simulation

Science.gov (United States)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2016-01-01

This study evaluated the effects of Communications Delays and Winds on Air Traffic Controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between UAS and manned aircraft in a simulation of the Dallas-Ft. Worth East-side airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from self-separation algorithms displayed on the Multi-Aircraft Simulation System. Winds tested did not affect the acceptability ratings. Communications delays tested included 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS.

Information Flow in Teachers' Organizations in Israel During Confrontations with Employers: I

Science.gov (United States)

Glasman, Naftaly S.

1975-01-01

First part of an article examining the content of information flow; the amount of information released; the mechanism of the flow; the factors affecting the content, amount, and mechanism; and the corollaries of information flow and the characteristics of the school system. Includes the questions put to the teachers. (Author/IRT)

Participative planning and information flow within management control

Directory of Open Access Journals (Sweden)

Tomasz Dyczkowski

2016-09-01

Full Text Available The paper examines the relationships between two different approaches to planning processes (participa- tive and non-participative and information flows within management control in companies. It augments the existing theoretical and empirical research by coupling management control and management infor- mation with participative planning, not only in operational but also in the strategic perspective. The re- sults presented in the paper stem from two consecutive studies, conducted between November 2010 and January 2012 and between November 2013 and January 2014. The studies comprised 397 and 179 Polish companies respectively. The authors formulated two hypotheses linking participative planning with upward and downward management information flows. The paper employed a quantitative approach, using the Spearman rank correlation analysis and hierarchical clustering using the Ward method, which enabled comparative analyses both in reference to various groups of companies included in particular research samples and over time. The results obtained showed the positive influence of participative plan- ning both on upward and downward information flows in enterprises. In particular, participative planning reduced information imbalances between top (the management and lower (employees of functional departments tiers in organisation structures.

Nursing Information Flow in Long-Term Care Facilities.

Science.gov (United States)

Wei, Quan; Courtney, Karen L

2018-04-01

 Long-term care (LTC), residential care requiring 24-hour nursing services, plays an important role in the health care service delivery system. The purpose of this study was to identify the needed clinical information and information flow to support LTC Registered Nurses (RNs) in care collaboration and clinical decision making.  This descriptive qualitative study combines direct observations and semistructured interviews, conducted at Alberta's LTC facilities between May 2014 and August 2015. The constant comparative method (CCM) of joint coding was used for data analysis.  Nine RNs from six LTC facilities participated in the study. The RN practice environment includes two essential RN information management aspects: information resources and information spaces. Ten commonly used information resources by RNs included: (1) RN-personal notes; (2) facility-specific templates/forms; (3) nursing processes/tasks; (4) paper-based resident profile; (5) daily care plans; (6) RN-notebooks; (7) medication administration records (MARs); (8) reporting software application (RAI-MDS); (9) people (care providers); and (10) references (i.e., books). Nurses used a combination of shared information spaces, such as the Nurses Station or RN-notebook, and personal information spaces, such as personal notebooks or "sticky" notes. Four essential RN information management functions were identified: collection, classification, storage, and distribution. Six sets of information were necessary to perform RN care tasks and communication, including: (1) admission, discharge, and transfer (ADT); (2) assessment; (3) care plan; (4) intervention (with two subsets: medication and care procedure); (5) report; and (6) reference. Based on the RN information management system requirements, a graphic information flow model was constructed.  This baseline study identified key components of a current LTC nursing information management system. The information flow model may assist health information

Automatically Tracing Information Flow of Vulnerability and Cyber-Attack Information through Text Strings

National Research Council Canada - National Science Library

Rowe, Neil C; Sjoberg, Eric; Adams, Paige

2008-01-01

... of it. We are developing data mining techniques to track the flow of such information by comparing important information-security Web sites, alert messages, and strings in packets to find similar words and sentences...

IFRS Mandatory Adoption Effect on the Information Asymmetry: Immediate or Delayed?

Directory of Open Access Journals (Sweden)

Hela Turki

2017-03-01

Full Text Available Abstract The purpose of this paper is to examine the relationship between the mandatory adoption of IFRS/IAS and the information content of earnings in the European Union. More accurately, this study aims to determine if the effect of IFRS adoption on the level of information asymmetry, apprehended by the cost of capital and the financial analysts’ forecasts, is immediate or delayed. Based on a longitudinal study, we find evidence that for the two first years of adoption, international standards reduces significantly the cost of capital and the dispersion of the financial analysts’ forecasts. Furthermore, the magnitude of this effect increases with increasing the number of years after IFRS adoption. The findings further show that the effect of IFRS adoption on financial analysts’ errors is not immediate and that the errors decrease from the third year following the date of the first adoption. Overall, the findings of this study highlight the importance of adopting IFRS in the reduction of information asymmetry.

Information spreading in Delay Tolerant Networks based on nodes' behaviors

Science.gov (United States)

Wu, Yahui; Deng, Su; Huang, Hongbin

2014-07-01

Information spreading in DTNs (Delay Tolerant Networks) adopts a store-carry-forward method, and nodes receive the message from others directly. However, it is hard to judge whether the information is safe in this communication mode. In this case, a node may observe other nodes' behaviors. At present, there is no theoretical model to describe the varying rule of the nodes' trusting level. In addition, due to the uncertainty of the connectivity in DTN, a node is hard to get the global state of the network. Therefore, a rational model about the node's trusting level should be a function of the node's own observing result. For example, if a node finds k nodes carrying a message, it may trust the information with probability p(k). This paper does not explore the real distribution of p(k), but instead presents a unifying theoretical framework to evaluate the performance of the information spreading in above case. This framework is an extension of the traditional SI (susceptible-infected) model, and is useful when p(k) conforms to any distribution. Simulations based on both synthetic and real motion traces show the accuracy of the framework. Finally, we explore the impact of the nodes' behaviors based on certain special distributions through numerical results.

Optimal nonlinear information processing capacity in delay-based reservoir computers

Science.gov (United States)

Grigoryeva, Lyudmila; Henriques, Julie; Larger, Laurent; Ortega, Juan-Pablo

2015-09-01

Reservoir computing is a recently introduced brain-inspired machine learning paradigm capable of excellent performances in the processing of empirical data. We focus in a particular kind of time-delay based reservoir computers that have been physically implemented using optical and electronic systems and have shown unprecedented data processing rates. Reservoir computing is well-known for the ease of the associated training scheme but also for the problematic sensitivity of its performance to architecture parameters. This article addresses the reservoir design problem, which remains the biggest challenge in the applicability of this information processing scheme. More specifically, we use the information available regarding the optimal reservoir working regimes to construct a functional link between the reservoir parameters and its performance. This function is used to explore various properties of the device and to choose the optimal reservoir architecture, thus replacing the tedious and time consuming parameter scannings used so far in the literature.

Predicting Information Flows in Network Traffic.

Science.gov (United States)

Hinich, Melvin J.; Molyneux, Robert E.

2003-01-01

Discusses information flow in networks and predicting network traffic and describes a study that uses time series analysis on a day's worth of Internet log data. Examines nonlinearity and traffic invariants, and suggests that prediction of network traffic may not be possible with current techniques. (Author/LRW)

'Informed and uninformed decision making'--women's reasoning, experiences and perceptions with regard to advanced maternal age and delayed childbearing: a meta-synthesis.

Science.gov (United States)

Cooke, Alison; Mills, Tracey A; Lavender, Tina

2010-10-01

To identify what factors affect women's decisions to delay childbearing, and to explore women's experiences and their perceptions of associated risks. Systematic procedures were used for search strategy, study selection, data extraction and analysis. Findings were synthesised using an approach developed from meta-ethnography. We included qualitative papers, not confined to geographical area (1980-2009). Databases included CINAHL, MEDLINE, EMBASE, PsycInfo, ASSIA, MIDIRS, British Nursing Index and the National Research Register. We selected qualitative empirical studies exploring the views and experiences of women of advanced maternal age who were childless or primigravidae with a singleton pregnancy or primiparous. Twelve papers fulfilled the selection criteria and were included for synthesis. Women appear to face an issue of 'informed and uninformed decision making'; those who believe they are informed but may not be, those who are not informed and find out they are at risk once pregnant, and those who are well informed but choose to delay pregnancy anyway. Maternity services could provide information to enable informed choice regarding timing of childbearing. Health professionals need to be mindful of the fact that women delay childbearing for various reasons. A strategy of pre-conception education may be beneficial in informing childbearing decisions. Obstetricians and midwives should be sensitive to the fact that women may not be aware of all the risks associated with delayed childbearing. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Priority Queues with Fractional Service for Tiered Delay QoS

Directory of Open Access Journals (Sweden)

Gary Chang

2015-12-01

Full Text Available Packet scheduling is key to quality of service (QoS capabilities of broadband wired and wireless networks. In a heterogeneous traffic environment, a comprehensive QoS packet scheduler must strike a balance between flow fairness and access delay. Many advanced packet scheduling solutions have targeted fair bandwidth allocation while protecting delay-constrained traffic by adding priority queue(s on top of a fair bandwidth scheduler. Priority queues are known to cause performance uncertainties and, thus, various modifications have been proposed. In this paper, we present a packet queueing engine dubbed Fractional Service Buffer (FSB, which, when coupled with a configurable flow scheduler, can achieve desired QoS objectives, such as fair throughputs and differentiated delay guarantees. Key performance metrics, such as delay limit and probability of delay limit violation, are derived as a function of key FSB parameters for each delay class in the packet queueing engine using diffusion approximations. OPNET simulations verify these analytical results.

A new car-following model with two delays

International Nuclear Information System (INIS)

Yu, Lei; Shi, Zhong-ke; Li, Tong

2014-01-01

A new car-following model is proposed by taking into account two different time delays in sensing headway and velocity. The effect of time delays on the stability analysis is studied. The theoretical and numerical results show that traffic jams are suppressed efficiently when the difference between two time delays decreases and those can be described by the solution of the modified Korteweg–de Vries (mKdV) equation. Traffic flow is more stable with two delays in headway and velocity than in the case with only one delay in headway. The impact of local small disturbance to the system is also studied.

Dynamics of Nonlinear Time-Delay Systems

CERN Document Server

Lakshmanan, Muthusamy

2010-01-01

Synchronization of chaotic systems, a patently nonlinear phenomenon, has emerged as a highly active interdisciplinary research topic at the interface of physics, biology, applied mathematics and engineering sciences. In this connection, time-delay systems described by delay differential equations have developed as particularly suitable tools for modeling specific dynamical systems. Indeed, time-delay is ubiquitous in many physical systems, for example due to finite switching speeds of amplifiers in electronic circuits, finite lengths of vehicles in traffic flows, finite signal propagation times in biological networks and circuits, and quite generally whenever memory effects are relevant. This monograph presents the basics of chaotic time-delay systems and their synchronization with an emphasis on the effects of time-delay feedback which give rise to new collective dynamics. Special attention is devoted to scalar chaotic/hyperchaotic time-delay systems, and some higher order models, occurring in different bran...

Developing measures for the evaluation of information flow efficiency in supply chains

OpenAIRE

Johanna A. Badenhorst; Claus Maurer; Tersia Brevis-Landsberg

2013-01-01

Member organisations in a supply chain are dependent on each other to provide material, services and information to perform optimally in the supply chain. Efficient, unrestricted information flow is needed in supply chains to function properly. Information flow is thus an element of supply chain management that needs to be managed. Yet, no indication could be found in supply chain management literature of the measurement of information flow efficiency. Hence, the aim of this article is to exp...

Information flow in the pharmaceutical supply chain

OpenAIRE

Yousefi, Nazila; Alibabaei, Ahmad

2015-01-01

Managing the supply chain plays an important role in creating competitive advantages for companies. Adequate information flow in supply chain is one of the most important issues in SCM. Therefore, using certain Information Systems can have a significant role in managing and integrating data and information within the supply chain. Pharmaceutical supply chain is more complex than many other supply chains, in the sense that it can affect social and political perspectives. On the other hand, man...

Secure Refactoring with Java Information Flow

DEFF Research Database (Denmark)

Helke, Steffen; Kammüunietd kller, Florian; Probst, Christian W.

2016-01-01

Refactoring means that a program is changed without changing its behaviour from an observer's point of view. Does the change of behaviour also imply that the security of the program is not affected by the changes? Using Myers and Liskov's distributed information flow control model DLM and its Java...

Tail dependence and information flow: Evidence from international equity markets

Science.gov (United States)

Al Rahahleh, Naseem; Bhatti, M. Ishaq; Adeinat, Iman

2017-05-01

Bhatti and Nguyen (2012) used the copula approach to measure the tail dependence between a number of international markets. They observed that some country pairs exhibit only left-tail dependence whereas others show only right-tail. However, the flow of information from uni-dimensional (one-tail) to bi-dimensional (two-tails) between various markets was not accounted for. In this study, we address the flow of information of this nature by using the dynamic conditional correlation (DCC-GARCH) model. More specifically, we use various versions of the DCC models to explain the nexus between the information flow of international equity and to explain the stochastic forward vs. backward dynamics of financial markets based on data for a 15-year period comprising 3,782 observations. We observed that the information flow between the US and Hong Kong markets and between the US and Australian markets are bi-directional. We also observed that the DCC model captures a wider co-movement structure and inter-connectedness compared to the symmetric Joe-Clayton copula.

Quantifying Information Flow between Two Chaotic Semiconductor Lasers Using Symbolic Transfer Entropy

International Nuclear Information System (INIS)

Li Nian-Qiang; Pan Wei; Yan Lian-Shan; Luo Bin; Xu Ming-Feng; Tang Yi-Long

2012-01-01

Symbolic transfer entropy (STE) is employed to quantify the dominant direction of information flow between two chaotic-semiconductor-laser time series. The information flow in unidirectionally and bidirectionally coupled systems was analyzed systematically. Numerical results show that the dependence relationship can be revealed if there exists any coupling between two chaotic semiconductor lasers. More importantly, in both unsynchronized and good synchronization regimes, the STE can be used to quantify the direction of information flow between the lasers, although the former case leads to a better identification. The results thus establish STE as an effective tool for quantifying the direction of information flow between chaotic-laser-based systems

The Role of the Hippocampus in Retaining Relational Information across Short Delays: The Importance of Memory Load

Science.gov (United States)

Jeneson, Annette; Mauldin, Kristin N.; Hopkins, Ramona O.; Squire, Larry R.

2011-01-01

Patients with hippocampal damage are sometimes impaired at remembering information across delays as short as a few seconds. How are these impairments to be understood? One possibility is that retention of some kinds of information is critically dependent on the hippocampus, regardless of the retention interval and regardless of whether the task…

Time-delayed chameleon: Analysis, synchronization and FPGA implementation

Science.gov (United States)

Rajagopal, Karthikeyan; Jafari, Sajad; Laarem, Guessas

2017-12-01

In this paper we report a time-delayed chameleon-like chaotic system which can belong to different families of chaotic attractors depending on the choices of parameters. Such a characteristic of self-excited and hidden chaotic flows in a simple 3D system with time delay has not been reported earlier. Dynamic analysis of the proposed time-delayed systems are analysed in time-delay space and parameter space. A novel adaptive modified functional projective lag synchronization algorithm is derived for synchronizing identical time-delayed chameleon systems with uncertain parameters. The proposed time-delayed systems and the synchronization algorithm with controllers and parameter estimates are then implemented in FPGA using hardware-software co-simulation and the results are presented.

Communication nets stochastic message flow and delay

CERN Document Server

Kleinrock, Leonard

2007-01-01

Considerable research has been devoted to the formulation and solution of problems involving flow within connected networks. Independent of these surveys, an extensive body of knowledge has accumulated on the subject of queues, particularly in regard to stochastic flow through single-node servicing facilities. This text combines studies of connected networks with those of stochastic flow, providing a basis for understanding the general behavior and operation of communication networks in realistic situations.Author Leonard Kleinrock of the Computer Science Department at UCLA created the basic p

ATFM airborne delays without extra fuel consumption in wind conditions

OpenAIRE

Delgado, L.; Prats, X.

2012-01-01

Air Traffic Flow Management (ATFM) regulations, such as ground holdings, are often canceled before their initially planned ending time. The ground delays impact on the cost of recovering part of the delay if the regulation is canceled, as aircraft are still at the origin airport. In previous publications, the authors have suggested a speed reduction strategy to split the assigned ATFM delay between ground delay and airborne delay. By flying at the the minimum speed that g...

Delayed complications after flow-diverter stenting: reactive in-stent stenosis and creeping stents.

Science.gov (United States)

Cohen, José E; Gomori, John Moshe; Moscovici, Samuel; Leker, Ronen R; Itshayek, Eyal

2014-07-01

We assessed the frequency and severity of changes in stent configuration and location after the treatment of intracranial aneurysms, and patterns of in-stent stenosis. We retrospectively reviewed data for consecutive aneurysm patients managed with endovascular implantation of flow-diverter stents (Silk Flow Diverter [Balt Extrusion, Montmorency, France] and Pipeline Embolization Device [ev3/Coviden, Minneapolis, MN, USA]) from October 2011 to July 2012. Routine 2, 6, 9-12, and 16-20 month follow-up angiograms were compared, with a focus on changes in stent configuration and location from immediately after deployment to angiographic follow-up, and the incidence and development of in-stent stenosis. Thirty-four patients with 42 aneurysms met inclusion criteria. The Silk device was implanted in 16 patients (47%, single device in 15), the Pipeline device in 18 (53%, single device in 16). On first follow-up angiography, in-stent stenosis was observed in 38% of Silk devices and 39% of Pipeline devices. In-stent stenosis was asymptomatic in 12 of 13 patients. One woman presented with transient ischemic attacks and required stent angioplasty due to end tapering and mild, diffuse in-stent stenosis. Configuration and location changes, including stent creeping and end tapering were seen in 2/16 patients (13%) with Silk devices, and 0/18 patients with Pipeline devices. We describe stent creeping and end tapering as unusual findings with the potential for delayed clinical complications. In-stent stenosis, with a unique behavior, is a frequent angiographic finding observed after flow-diverter stent implant. The stenosis is usually asymptomatic; however, close clinical and angiographic monitoring is mandatory for individualized management. Copyright © 2013 Elsevier Ltd. All rights reserved.

Information Graph Flow: A Geometric Approximation of Quantum and Statistical Systems

Science.gov (United States)

Vanchurin, Vitaly

2018-05-01

Given a quantum (or statistical) system with a very large number of degrees of freedom and a preferred tensor product factorization of the Hilbert space (or of a space of distributions) we describe how it can be approximated with a very low-dimensional field theory with geometric degrees of freedom. The geometric approximation procedure consists of three steps. The first step is to construct weighted graphs (we call information graphs) with vertices representing subsystems (e.g., qubits or random variables) and edges representing mutual information (or the flow of information) between subsystems. The second step is to deform the adjacency matrices of the information graphs to that of a (locally) low-dimensional lattice using the graph flow equations introduced in the paper. (Note that the graph flow produces very sparse adjacency matrices and thus might also be used, for example, in machine learning or network science where the task of graph sparsification is of a central importance.) The third step is to define an emergent metric and to derive an effective description of the metric and possibly other degrees of freedom. To illustrate the procedure we analyze (numerically and analytically) two information graph flows with geometric attractors (towards locally one- and two-dimensional lattices) and metric perturbations obeying a geometric flow equation. Our analysis also suggests a possible approach to (a non-perturbative) quantum gravity in which the geometry (a secondary object) emerges directly from a quantum state (a primary object) due to the flow of the information graphs.

From fear to flow personality and information interaction

CERN Document Server

Heinstrom, Jannica

2010-01-01

From Fear to Flow explores how personality traits may influence attitude, behaviour and reaction to information. Consideration is made for individual differences in information behaviour and reasons behind individual search differences. The book reviews personality and information behaviour and discusses how personality may influence the attitude towards information. Reaction to information is examined in contexts such as everyday life, decision-making, work, studies and human-computer interaction.Introduces a little researched area which is current and needed in our Informatio

Information flow through the disaster circle

DEFF Research Database (Denmark)

Egedorf, Maren Marie; Villanueva Holm-Nielsen, Pablo

The traditional view of the disaster circle is phase based. Disaster and development professionals recognize that the actions carried out in the various phases of the disaster management cycle are overlapping and build upon each other, having resilience as the overall goal. However information does...... not necessarily flow across the phases of the circle in an effective manner. This is particularly true for the information that crosses the disaster point of the circle. Organisations carry out assessments, surveys and baselines for various purposes, at various points of time in the disaster circle. Output...

Information Flow Scheduling in Concurrent Multi-Product Development Based on DSM

Science.gov (United States)

Sun, Qing-Chao; Huang, Wei-Qiang; Jiang, Ying-Jie; Sun, Wei

2017-09-01

Multi-product collaborative development is adopted widely in manufacturing enterprise, while the present multi-project planning models don't take technical/data interactions of multiple products into account. To decrease the influence of technical/data interactions on project progresses, the information flow scheduling models based on the extended DSM is presented. Firstly, information dependencies are divided into four types: series, parallel, coupling and similar. Secondly, different types of dependencies are expressed as DSM units, and the extended DSM model is brought forward, described as a block matrix. Furthermore, the information flow scheduling methods is proposed, which involves four types of operations, where partitioning and clustering algorithm are modified from DSM for ensuring progress of high-priority project, merging and converting is the specific computation of the extended DSM. Finally, the information flow scheduling of two machine tools development is analyzed with example, and different project priorities correspond to different task sequences and total coordination cost. The proposed methodology provides a detailed instruction for information flow scheduling in multi-product development, with specially concerning technical/data interactions.

Delayed early proprioceptive information processing in schizophrenia

DEFF Research Database (Denmark)

Arnfred, Sidse M; Hemmingsen, RP; Parnas, Josef

2006-01-01

. In the patients, the early contralateral parietal activity was delayed and later central activity had increased amplitude, but gating was unaffected. The results could be understood within the "deficiency of corollary discharge" model of schizophrenia but not within the "filtering" theory. Further studies...

Information Flow Through Stages of Complex Engineering Design Projects: A Dynamic Network Analysis Approach

DEFF Research Database (Denmark)

Parraguez, Pedro; Eppinger, Steven D.; Maier, Anja

2015-01-01

The pattern of information flow through the network of interdependent design activities is thought to be an important determinant of engineering design process results. A previously unexplored aspect of such patterns relates to the temporal dynamics of information transfer between activities...... design process and thus support theory-building toward the evolution of information flows through systems engineering stages. Implications include guidance on how to analyze and predict information flows as well as better planning of information flows in engineering design projects according...

A New Delay Connection for Long Short-Term Memory Networks.

Science.gov (United States)

Wang, Jianyong; Zhang, Lei; Chen, Yuanyuan; Yi, Zhang

2017-12-17

Connections play a crucial role in neural network (NN) learning because they determine how information flows in NNs. Suitable connection mechanisms may extensively enlarge the learning capability and reduce the negative effect of gradient problems. In this paper, a new delay connection is proposed for Long Short-Term Memory (LSTM) unit to develop a more sophisticated recurrent unit, called Delay Connected LSTM (DCLSTM). The proposed delay connection brings two main merits to DCLSTM with introducing no extra parameters. First, it allows the output of the DCLSTM unit to maintain LSTM, which is absent in the LSTM unit. Second, the proposed delay connection helps to bridge the error signals to previous time steps and allows it to be back-propagated across several layers without vanishing too quickly. To evaluate the performance of the proposed delay connections, the DCLSTM model with and without peephole connections was compared with four state-of-the-art recurrent model on two sequence classification tasks. DCLSTM model outperformed the other models with higher accuracy and F1[Formula: see text]score. Furthermore, the networks with multiple stacked DCLSTM layers and the standard LSTM layer were evaluated on Penn Treebank (PTB) language modeling. The DCLSTM model achieved lower perplexity (PPL)/bit-per-character (BPC) than the standard LSTM model. The experiments demonstrate that the learning of the DCLSTM models is more stable and efficient.

Climate Informed Low Flow Frequency Analysis Using Nonstationary Modeling

Science.gov (United States)

Liu, D.; Guo, S.; Lian, Y.

2014-12-01

Stationarity is often assumed for frequency analysis of low flows in water resources management and planning. However, many studies have shown that flow characteristics, particularly the frequency spectrum of extreme hydrologic events,were modified by climate change and human activities and the conventional frequency analysis without considering the non-stationary characteristics may lead to costly design. The analysis presented in this paper was based on the more than 100 years of daily flow data from the Yichang gaging station 44 kilometers downstream of the Three Gorges Dam. The Mann-Kendall trend test under the scaling hypothesis showed that the annual low flows had significant monotonic trend, whereas an abrupt change point was identified in 1936 by the Pettitt test. The climate informed low flow frequency analysis and the divided and combined method are employed to account for the impacts from related climate variables and the nonstationarities in annual low flows. Without prior knowledge of the probability density function for the gaging station, six distribution functions including the Generalized Extreme Values (GEV), Pearson Type III, Gumbel, Gamma, Lognormal, and Weibull distributions have been tested to find the best fit, in which the local likelihood method is used to estimate the parameters. Analyses show that GEV had the best fit for the observed low flows. This study has also shown that the climate informed low flow frequency analysis is able to exploit the link between climate indices and low flows, which would account for the dynamic feature for reservoir management and provide more accurate and reliable designs for infrastructure and water supply.

Engineering fluidic delays in paper-based devices using laser direct-writing.

Science.gov (United States)

He, P J W; Katis, I N; Eason, R W; Sones, C L

2015-10-21

We report the use of a new laser-based direct-write technique that allows programmable and timed fluid delivery in channels within a paper substrate which enables implementation of multi-step analytical assays. The technique is based on laser-induced photo-polymerisation, and through adjustment of the laser writing parameters such as the laser power and scan speed we can control the depth and/or the porosity of hydrophobic barriers which, when fabricated in the fluid path, produce controllable fluid delay. We have patterned these flow delaying barriers at pre-defined locations in the fluidic channels using either a continuous wave laser at 405 nm, or a pulsed laser operating at 266 nm. Using this delay patterning protocol we generated flow delays spanning from a few minutes to over half an hour. Since the channels and flow delay barriers can be written via a common laser-writing process, this is a distinct improvement over other methods that require specialist operating environments, or custom-designed equipment. This technique can therefore be used for rapid fabrication of paper-based microfluidic devices that can perform single or multistep analytical assays.

CPS Transformation of Flow Information, Part II: Administrative Reductions

DEFF Research Database (Denmark)

Damian, Daniel; Danvy, Olivier

2001-01-01

the least solution. Preservation of least solutions solves a problem that was left open in Palsberg and Wand's article ‘CPS Transformation of Flow Information.’ Together, Palsberg and Wand's article and the present article show how to map in linear time the least solution of the flow constraints...

75 FR 70714 - Global Free Flow of Information on the Internet

Science.gov (United States)

2010-11-18

.... 100921457-0561-02] RIN 0660-XA20 Global Free Flow of Information on the Internet AGENCY: National... of comment period. SUMMARY: The Department of Commerce's Internet Policy Task Force announces that... on the global free flow of information on the Internet has been reopened and will extend until 5 p.m...

Petri net modeling of encrypted information flow in federated cloud

Science.gov (United States)

Khushk, Abdul Rauf; Li, Xiaozhong

2017-08-01

Solutions proposed and developed for the cost-effective cloud systems suffer from a combination of secure private clouds and less secure public clouds. Need to locate applications within different clouds poses a security risk to the information flow of the entire system. This study addresses this by assigning security levels of a given lattice to the entities of a federated cloud system. A dynamic flow sensitive security model featuring Bell-LaPadula procedures is explored that tracks and authenticates the secure information flow in federated clouds. Additionally, a Petri net model is considered as a case study to represent the proposed system and further validate the performance of the said system.

Information flow to assess cardiorespiratory interactions in patients on weaning trials.

Science.gov (United States)

Vallverdú, M; Tibaduisa, O; Clariá, F; Hoyer, D; Giraldo, B; Benito, S; Caminal, P

2006-01-01

Nonlinear processes of the autonomic nervous system (ANS) can produce breath-to-breath variability in the pattern of breathing. In order to provide assess to these nonlinear processes, nonlinear statistical dependencies between heart rate variability and respiratory pattern variability are analyzed. In this way, auto-mutual information and cross-mutual information concepts are applied. This information flow analysis is presented as a short-term non linear analysis method to investigate the information flow interactions in patients on weaning trials. 78 patients from mechanical ventilation were studied: Group A of 28 patients that failed to maintain spontaneous breathing and were reconnected; Group B of 50 patients with successful trials. The results show lower complexity with an increase of information flow in group A than in group B. Furthermore, a more (weakly) coupled nonlinear oscillator behavior is observed in the series of group A than in B.

Information about the new 8-group delayed neutron set preparation

International Nuclear Information System (INIS)

Svarny, J.

1998-01-01

Some comments to the present state concerning delayed neutron data preparation is given and preliminary analysis of the new 8-group delayed data (relative abundances) is presented. Comparisons of the 8-group to 6-group set is given for rod drop experiment (Unit 1, Cycle 14, NPP Dukovany).(Author)

Delay-feedback control strategy for reducing CO2 emission of traffic flow system

Science.gov (United States)

Zhang, Li-Dong; Zhu, Wen-Xing

2015-06-01

To study the signal control strategy for reducing traffic emission theoretically, we first presented a kind of discrete traffic flow model with relative speed term based on traditional coupled map car-following model. In the model, the relative speed difference between two successive running cars is incorporated into following vehicle's acceleration running equation. Then we analyzed its stability condition with discrete control system stability theory. Third, we designed a delay-feedback controller to suppress traffic jam and decrease traffic emission based on modern controller theory. Last, numerical simulations are made to support our theoretical results, including the comparison of models' stability analysis, the influence of model type and signal control on CO2 emissions. The results show that the temporal behavior of our model is superior to other models, and the traffic signal controller has good effect on traffic jam suppression and traffic CO2 emission, which fully supports the theoretical conclusions.

Brain network clustering with information flow motifs

NARCIS (Netherlands)

Märtens, M.; Meier, J.M.; Hillebrand, Arjan; Tewarie, Prejaas; Van Mieghem, P.F.A.

2017-01-01

Recent work has revealed frequency-dependent global patterns of information flow by a network analysis of magnetoencephalography data of the human brain. However, it is unknown which properties on a small subgraph-scale of those functional brain networks are dominant at different frequencies bands.

Information flow in a network of dispersed signalers-receivers

Science.gov (United States)

Halupka, Konrad

2017-11-01

I consider a stochastic model of multi-agent communication in regular network. The model describes how dispersed animals exchange information. Each agent can initiate and transfer the signal to its nearest neighbors, who may pass it farther. For an external observer of busy networks, signaling activity may appear random, even though information flow actually thrives. Only when signal initiation and transfer are at low levels do spatiotemporal autocorrelations emerge as clumping signaling activity in space and pink noise time series. Under such conditions, the costs of signaling are moderate, but the signaler can reach a large audience. I propose that real-world networks of dispersed signalers-receivers may self-organize into this state and the flow of information maintains their integrity.

How does variability in input load relate to the probability of critically delayed delivery in a simple Multipart Re-entrant Flow-line problem?

DEFF Research Database (Denmark)

Nielsen, Erland Hejn

2003-01-01

of the estimation of the probability of critically delayed delivery beyond a specified threshold value given a certain production batch size and try to establish a relation to certain parameters that can be linked to the degree of regularity of the arrival stream of parts to the job/flow-shop. This last aspect...... relates remotely to the Lean Thinking philosophy that praises the smooth and uninterrupted production flow to be beneficial to the overall operation of productive plants in general, and we will link our findings to this discussion as well....

Information-flow-based Access Control for Virtualized Systems

Directory of Open Access Journals (Sweden)

Dmitriy Aleksandrovich Postoev

2014-12-01

Full Text Available The article is devoted to the method of information-flow-based access control, adopted for virtualized systems. General structure of access control system for virtual infrastructure is proposed.

Breaking camouflage and detecting targets require optic flow and image structure information.

Science.gov (United States)

Pan, Jing Samantha; Bingham, Ned; Chen, Chang; Bingham, Geoffrey P

2017-08-01

Use of motion to break camouflage extends back to the Cambrian [In the Blink of an Eye: How Vision Sparked the Big Bang of Evolution (New York Basic Books, 2003)]. We investigated the ability to break camouflage and continue to see camouflaged targets after motion stops. This is crucial for the survival of hunting predators. With camouflage, visual targets and distracters cannot be distinguished using only static image structure (i.e., appearance). Motion generates another source of optical information, optic flow, which breaks camouflage and specifies target locations. Optic flow calibrates image structure with respect to spatial relations among targets and distracters, and calibrated image structure makes previously camouflaged targets perceptible in a temporally stable fashion after motion stops. We investigated this proposal using laboratory experiments and compared how many camouflaged targets were identified either with optic flow information alone or with combined optic flow and image structure information. Our results show that the combination of motion-generated optic flow and target-projected image structure information yielded efficient and stable perception of camouflaged targets.

INFORMATION FLOW ASSURED BY ITC CONTINUITY PLANNING

Directory of Open Access Journals (Sweden)

Gabriel Cozgarea

2009-05-01

Full Text Available Forwarding the frequent usage of complex processes and the big volume of information, it is imperative to manage the automatic circuit of the document flow in a company activity. The main advantage of such a system consist in document waiting to be proces

Energy Demodulation Algorithm for Flow Velocity Measurement of Oil-Gas-Water Three-Phase Flow

Directory of Open Access Journals (Sweden)

Yingwei Li

2014-01-01

Full Text Available Flow velocity measurement was an important research of oil-gas-water three-phase flow parameter measurements. In order to satisfy the increasing demands for flow detection technology, the paper presented a gas-liquid phase flow velocity measurement method which was based on energy demodulation algorithm combing with time delay estimation technology. First, a gas-liquid phase separation method of oil-gas-water three-phase flow based on energy demodulation algorithm and blind signal separation technology was proposed. The separation of oil-gas-water three-phase signals which were sampled by conductance sensor performed well, so the gas-phase signal and the liquid-phase signal were obtained. Second, we used the time delay estimation technology to get the delay time of gas-phase signals and liquid-phase signals, respectively, and the gas-phase velocity and the liquid-phase velocity were derived. At last, the experiment was performed at oil-gas-water three-phase flow loop, and the results indicated that the measurement errors met the need of velocity measurement. So it provided a feasible method for gas-liquid phase velocity measurement of the oil-gas-water three-phase flow.

Systematic Sampling and Cluster Sampling of Packet Delays

OpenAIRE

Lindh, Thomas

2006-01-01

Based on experiences of a traffic flow performance meter this papersuggests and evaluates cluster sampling and systematic sampling as methods toestimate average packet delays. Systematic sampling facilitates for exampletime analysis, frequency analysis and jitter measurements. Cluster samplingwith repeated trains of periodically spaced sampling units separated by randomstarting periods, and systematic sampling are evaluated with respect to accuracyand precision. Packet delay traces have been ...

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

International Nuclear Information System (INIS)

Wang Shen-Quan; Feng Jian; Zhao Qing

2012-01-01

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

Controlled Nonlinear Stochastic Delay Equations: Part II: Approximations and Pipe-Flow Representations

International Nuclear Information System (INIS)

Kushner, Harold J.

2012-01-01

This is the second part of a work dealing with key issues that have not been addressed in the modeling and numerical optimization of nonlinear stochastic delay systems. We consider new classes of models, such as those with nonlinear functions of several controls (such as products), each with is own delay, controlled random Poisson measure driving terms, admissions control with delayed retrials, and others. Part I was concerned with issues concerning the class of admissible controls and their approximations, since the classical definitions are inadequate for our models. This part is concerned with transportation equation representations and their approximations. Such representations of nonlinear stochastic delay models have been crucial in the development of numerical algorithms with much reduced memory and computational requirements. The representations for the new models are not obvious and are developed. They also provide a template for the adaptation of the Markov chain approximation numerical methods.

Quantifying, characterizing, and controlling information flow in ultracold atomic gases

International Nuclear Information System (INIS)

Haikka, P.; McEndoo, S.; Maniscalco, S.; De Chiara, G.; Palma, G. M.

2011-01-01

We study quantum information flow in a model comprised of a trapped impurity qubit immersed in a Bose-Einstein-condensed reservoir. We demonstrate how information flux between the qubit and the condensate can be manipulated by engineering the ultracold reservoir within experimentally realistic limits. We show that this system undergoes a transition from Markovian to non-Markovian dynamics, which can be controlled by changing key parameters such as the condensate scattering length. In this way, one can realize a quantum simulator of both Markovian and non-Markovian open quantum systems, the latter ones being characterized by a reverse flow of information from the background gas (reservoir) to the impurity (system).

Control of Thermodynamical System with Input-Dependent State Delays

DEFF Research Database (Denmark)

Bendtsen, Jan Dimon; Krstic, Miroslav

2013-01-01

We consider control of a cooling system with several consumers that require cooling from a common source. The flow feeding coolant to the consumers can be controlled, but due to significant physical distances between the common source and the consumers, the coolant flow takes a non......-negligible amount of time to travel to the consumers, giving rise to input-dependent state delays. We first present a simple bilinear model of the system, followed by a state feedback control design that is able to stabilize the system at a chosen equilibrium in spite of the delays. We also present a heuristic...

Exploring default mode and information flow on the web.

Science.gov (United States)

Oka, Mizuki; Ikegami, Takashi

2013-01-01

Social networking services (e.g., Twitter, Facebook) are now major sources of World Wide Web (called "Web") dynamics, together with Web search services (e.g., Google). These two types of Web services mutually influence each other but generate different dynamics. In this paper, we distinguish two modes of Web dynamics: the reactive mode and the default mode. It is assumed that Twitter messages (called "tweets") and Google search queries react to significant social movements and events, but they also demonstrate signs of becoming self-activated, thereby forming a baseline Web activity. We define the former as the reactive mode and the latter as the default mode of the Web. In this paper, we investigate these reactive and default modes of the Web's dynamics using transfer entropy (TE). The amount of information transferred between a time series of 1,000 frequent keywords in Twitter and the same keywords in Google queries is investigated across an 11-month time period. Study of the information flow on Google and Twitter revealed that information is generally transferred from Twitter to Google, indicating that Twitter time series have some preceding information about Google time series. We also studied the information flow among different Twitter keywords time series by taking keywords as nodes and flow directions as edges of a network. An analysis of this network revealed that frequent keywords tend to become an information source and infrequent keywords tend to become sink for other keywords. Based on these findings, we hypothesize that frequent keywords form the Web's default mode, which becomes an information source for infrequent keywords that generally form the Web's reactive mode. We also found that the Web consists of different time resolutions with respect to TE among Twitter keywords, which will be another focal point of this paper.

A Reduced-Order Controller Considering High-Order Modal Information of High-Rise Buildings for AMD Control System with Time-Delay

Directory of Open Access Journals (Sweden)

Zuo-Hua Li

2017-01-01

Full Text Available Time-delays of control force calculation, data acquisition, and actuator response will degrade the performance of Active Mass Damper (AMD control systems. To reduce the influence, model reduction method is used to deal with the original controlled structure. However, during the procedure, the related hierarchy information of small eigenvalues will be directly discorded. As a result, the reduced-order model ignores the information of high-order mode, which will reduce the design accuracy of an AMD control system. In this paper, a new reduced-order controller based on the improved Balanced Truncation (BT method is designed to reduce the calculation time and to retain the abandoned high-order modal information. It includes high-order natural frequency, damping ratio, and vibration modal information of the original structure. Then, a control gain design method based on Guaranteed Cost Control (GCC algorithm is presented to eliminate the adverse effects of data acquisition and actuator response time-delays in the design process of the reduced-order controller. To verify its effectiveness, the proposed methodology is applied to a numerical example of a ten-storey frame and an experiment of a single-span four-storey steel frame. Both numerical and experimental results demonstrate that the reduced-order controller with GCC algorithm has an excellent control effect; meanwhile it can compensate time-delays effectively.

Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography

International Nuclear Information System (INIS)

Ryding, E.; Sjoeholm, H.; Skeidsvoll, H.; Elmqvist, D.

1989-01-01

We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis). (author)

Analysis Of Primary Coolant Suction Side Pressure In The Delay Chamber Of The RSG-GAS

International Nuclear Information System (INIS)

Dibyo, Sukmanto

2000-01-01

Delay chamber is a tank to delay flow that located in the primary cooling suction side of RSG-GAS. A void occurred when operation reactor caused by too high the delta P at inlet suction pump. The condition may be avoided by using one line mode of the cooling flow. The analysis show that void volume in the delay chamber is occurred because the coolant negative pressure lowers the saturation pressure should be avoided though decreasing the delta P until about 0.1 bar at about 45 exp 0 C. Solution suggested are to use bypass flow from the spent fuel to the delay chamber. Coolant temperature can be also decreased by decreasing the power level of the reactor as well as improving the heat exchanger and cooling tower performances

Decision making and information flows in precision agriculture

DEFF Research Database (Denmark)

Fountas, S.; Wulfsohn, Dvora-Laiô; Blackmore, B.S.

A participative methology was developed in which farm managers decomposed their process of decision making in Precision Agriculture (PA) into brief secision statesments along with associated information requirements. The methodology was first developed on a university research farm in Denmark...... and further revised during testing on a number of research and commercial farms in Indiana, USA. Twenty-one decision analysis factors were idebfied to characterise a farm manager's decision-making process. Then a general data flow diagram (DFD) was constructed that describes the information flows "from data...... to decision". Illustrative examples of the model in the form of DFDs are presented for a strategic and an operational decision. The model was validated for a range of decisions related to operations by three university farm managers and by five commercial farmers practicing PA for cereal, corn and soybean...

New Results on Passivity Analysis of Stochastic Neural Networks with Time-Varying Delay and Leakage Delay

Directory of Open Access Journals (Sweden)

YaJun Li

2015-01-01

Full Text Available The passivity problem for a class of stochastic neural networks systems (SNNs with varying delay and leakage delay has been further studied in this paper. By constructing a more effective Lyapunov functional, employing the free-weighting matrix approach, and combining with integral inequality technic and stochastic analysis theory, the delay-dependent conditions have been proposed such that SNNs are asymptotically stable with guaranteed performance. The time-varying delay is divided into several subintervals and two adjustable parameters are introduced; more information about time delay is utilised and less conservative results have been obtained. Examples are provided to illustrate the less conservatism of the proposed method and simulations are given to show the impact of leakage delay on stability of SNNs.

INFORMATION FLOW IN SUPPLY CHAIN MANAGEMENT WITH AN EXAMPLE OF WASTE MANAGEMENT COMPANY

OpenAIRE

Joanna Nowakowska-Grunt; Janusz Grabara

2007-01-01

The paper presents information flow process in management of supply chains. Authors notices information flows as a driving element of the global supply chain. Authors points also on the logistics aspects in supply chain of waste management company

Information systems for material flow management in construction processes

Science.gov (United States)

Mesároš, P.; Mandičák, T.

2015-01-01

The article describes the options for the management of material flows in the construction process. Management and resource planning is one of the key factors influencing the effectiveness of construction project. It is very difficult to set these flows correctly. The current period offers several options and tools to do this. Information systems and their modules can be used just for the management of materials in the construction process.

Topology identification of the complex networks with non-delayed and delayed coupling

International Nuclear Information System (INIS)

Guo Wanli; Chen Shihua; Sun Wen

2009-01-01

In practical situation, there exists many uncertain information in complex networks, such as the topological structures. So the topology identification is an important issue in the research of the complex networks. Based on LaSalle's invariance principle, in this Letter, an adaptive controlling method is proposed to identify the topology of a weighted general complex network model with non-delayed and delayed coupling. Finally, simulation results show that the method is effective.

Discretionary Information Flow Control for Interaction-Oriented Specifications

DEFF Research Database (Denmark)

Lluch Lafuente, Alberto; Nielson, Flemming; Nielson, Hanne Riis

2015-01-01

system for statically checking if a system specification ensures an information flow policy. The approach is illustrated with two archetypal examples of distributed and parallel computing systems: a protocol for an identity-secured data providing service and a parallel MapReduce computation....

Spatially dynamic recurrent information flow across long-range dorsal motor network encodes selective motor goals.

Science.gov (United States)

Yoo, Peter E; Hagan, Maureen A; John, Sam E; Opie, Nicholas L; Ordidge, Roger J; O'Brien, Terence J; Oxley, Thomas J; Moffat, Bradford A; Wong, Yan T

2018-03-08

Performing voluntary movements involves many regions of the brain, but it is unknown how they work together to plan and execute specific movements. We recorded high-resolution ultra-high-field blood-oxygen-level-dependent signal during a cued ankle-dorsiflexion task. The spatiotemporal dynamics and the patterns of task-relevant information flow across the dorsal motor network were investigated. We show that task-relevant information appears and decays earlier in the higher order areas of the dorsal motor network then in the primary motor cortex. Furthermore, the results show that task-relevant information is encoded in general initially, and then selective goals are subsequently encoded in specifics subregions across the network. Importantly, the patterns of recurrent information flow across the network vary across different subregions depending on the goal. Recurrent information flow was observed across all higher order areas of the dorsal motor network in the subregions encoding for the current goal. In contrast, only the top-down information flow from the supplementary motor cortex to the frontoparietal regions, with weakened recurrent information flow between the frontoparietal regions and bottom-up information flow from the frontoparietal regions to the supplementary cortex were observed in the subregions encoding for the opposing goal. We conclude that selective motor goal encoding and execution rely on goal-dependent differences in subregional recurrent information flow patterns across the long-range dorsal motor network areas that exhibit graded functional specialization. © 2018 Wiley Periodicals, Inc.

Directional information flow in patients with Alzheimer's disease. A source-space resting-state MEG study.

Science.gov (United States)

Engels, M M A; Yu, M; Stam, C J; Gouw, A A; van der Flier, W M; Scheltens, Ph; van Straaten, E C W; Hillebrand, A

2017-01-01

In a recent magnetoencephalography (MEG) study, we found posterior-to-anterior information flow over the cortex in higher frequency bands in healthy subjects, with a reversed pattern in the theta band. A disruption of information flow may underlie clinical symptoms in Alzheimer's disease (AD). In AD, highly connected regions (hubs) in posterior areas are mostly disrupted. We therefore hypothesized that in AD the information flow from these hub regions would be disturbed. We used resting-state MEG recordings from 27 early-onset AD patients and 26 healthy controls. Using beamformer-based virtual electrodes, we estimated neuronal oscillatory activity for 78 cortical regions of interest (ROIs) and 12 subcortical ROIs of the AAL atlas, and calculated the directed phase transfer entropy (dPTE) as a measure of information flow between these ROIs. Group differences were evaluated using permutation tests and, for the AD group, associations between dPTE and general cognition or CSF biomarkers were determined using Spearman correlation coefficients. We confirmed the previously reported posterior-to-anterior information flow in the higher frequency bands in the healthy controls, and found it to be disturbed in the beta band in AD. Most prominently, the information flow from the precuneus and the visual cortex, towards frontal and subcortical structures, was decreased in AD. These disruptions did not correlate with cognitive impairment or CSF biomarkers. We conclude that AD pathology may affect the flow of information between brain regions, particularly from posterior hub regions, and that changes in the information flow in the beta band indicate an aspect of the pathophysiological process in AD.

Hybrid static-runtime information flow and declassification enforcement

NARCIS (Netherlands)

Pontes Soares Rocha, B.; Conti, M.; Etalle, S.; Crispo, B.

2013-01-01

There are different paradigms for enforcing information flow and declassification policies. These approaches can be divided into static analyzers and runtime enforcers. Each class has its own strengths and weaknesses, each being able to enforce a different set of policies. In this paper we introduce

Hybrid static-runtime information flow and declassification enforcement

NARCIS (Netherlands)

Rocha, Bruno P.S.; Conti, Mauro; Etalle, Sandro; Crispo, Bruno

There are different paradigms for enforcing information flow and declassification policies. These approaches can be divided into static analyzers and runtime enforcers. Each class has its own strengths and weaknesses, each being able to enforce a different set of policies. In this paper, we

Delay Variation Model with RTP Flows Behavior in Accordance with M/D/1 Kendall's Notation

Directory of Open Access Journals (Sweden)

Miroslav Voznak

2010-01-01

Full Text Available This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, its generation, facilities and its mathematical formulations. A new approach to the delay variation model is presented; its validation has been done by an experiment.

Comparison of blood flow and cell function in ischemic skin flaps

International Nuclear Information System (INIS)

Bean, D.; Rees, R.S.; O'Leary, J.P.; Lynch, J.B.

1984-01-01

Cellular function and blood flow in acute, steroid-treated, and surgically delayed random skin flaps have been examined. In these studies, the period following flap elevation could be divided into early (0-2 hr), intermediate (4-6 hr), and late (12 hr) periods of ischemia, based on the cutaneous blood flow and cellular function measured by thallium-201 uptake. There was a close correlation between blood flow and cellular function during the early period of ischemia which became worse with time. Blood flow studies demonstrated a significant difference between the early and intermediate periods of ischemia which was abolished by surgical delay. Improvement in cellular function was accomplished by improved blood flow in the surgically delayed flaps, while steroid-treated flaps enhanced cellular metabolism by another mechanism. Cellular function approximated blood flow during the early and immediate period of ischemia. Steroids may augment cellular function without improving blood flow, while surgical delay improves cellular function by improving blood flow

Delay-Range-Dependent H∞ Control for Automatic Mooring Positioning System with Time-Varying Input Delay

Directory of Open Access Journals (Sweden)

Xiaoyu Su

2014-01-01

Full Text Available Aiming at the economy and security of the positioning system in semi-submersible platform, the paper presents a new scheme based on the mooring line switching strategy. Considering the input delay in switching process, H∞ control with time-varying input delay is designed to calculate the control forces to resist disturbing forces. In order to reduce the conservativeness, the information of the lower bound of delay is taken into account, and a Lyapunov function which contains the range of delay is constructed. Besides, the input constraint is considered to avoid breakage of mooring lines. The sufficient conditions for delay-range-dependent stabilization are derived in terms of LMI, and the controller is also obtained. The effectiveness of the proposed approach is illustrated by a realistic design example.

Analytical applications for delayed neutrons

International Nuclear Information System (INIS)

Eccleston, G.W.

1983-01-01

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

Direction of information flow in large-scale resting-state networks is frequency-dependent.

Science.gov (United States)

Hillebrand, Arjan; Tewarie, Prejaas; van Dellen, Edwin; Yu, Meichen; Carbo, Ellen W S; Douw, Linda; Gouw, Alida A; van Straaten, Elisabeth C W; Stam, Cornelis J

2016-04-05

Normal brain function requires interactions between spatially separated, and functionally specialized, macroscopic regions, yet the directionality of these interactions in large-scale functional networks is unknown. Magnetoencephalography was used to determine the directionality of these interactions, where directionality was inferred from time series of beamformer-reconstructed estimates of neuronal activation, using a recently proposed measure of phase transfer entropy. We observed well-organized posterior-to-anterior patterns of information flow in the higher-frequency bands (alpha1, alpha2, and beta band), dominated by regions in the visual cortex and posterior default mode network. Opposite patterns of anterior-to-posterior flow were found in the theta band, involving mainly regions in the frontal lobe that were sending information to a more distributed network. Many strong information senders in the theta band were also frequent receivers in the alpha2 band, and vice versa. Our results provide evidence that large-scale resting-state patterns of information flow in the human brain form frequency-dependent reentry loops that are dominated by flow from parieto-occipital cortex to integrative frontal areas in the higher-frequency bands, which is mirrored by a theta band anterior-to-posterior flow.

Delays in the operating room: signs of an imperfect system.

Science.gov (United States)

Wong, Janice; Khu, Kathleen Joy; Kaderali, Zul; Bernstein, Mark

2010-06-01

Delays in the operating room have a negative effect on its efficiency and the working environment. In this prospective study, we analyzed data on perioperative system delays. One neurosurgeon prospectively recorded all errors, including perioperative delays, for consecutive patients undergoing elective procedures from May 2000 to February 2009. We analyzed the prevalence, causes and impact of perioperative system delays that occurred in one neurosurgeon's practice. A total of 1531 elective surgical cases were performed during the study period. Delays were the most common type of error (33.6%), and more than half (51.4%) of all cases had at least 1 delay. The most common cause of delay was equipment failure. The first cases of the day and cranial cases had more delays than subsequent cases and spinal cases, respectively. A delay in starting the first case was associated with subsequent delays. Delays frequently occur in the operating room and have a major effect on patient flow and resource utilization. Thorough documentation of perioperative delays provides a basis for the development of solutions for improving operating room efficiency and illustrates the principles underlying the causes of operating room delays across surgical disciplines.

Delay signatures in the chaotic intensity output of a quantum dot ...

Indian Academy of Sciences (India)

Delay identification from the chaotic intensity output of a quantum dot laser with optical feedback is done using numerical and information theoretic techniques. Four quantifiers, namely autocorrelation function, delayed mutual information, permutation entropy and permutation statistical complexity, are employed in delay ...

Development of a methodology for analysis of delayed-neutron signals

International Nuclear Information System (INIS)

Gross, K.C.; Strain, R.V.; Fryer, R.M.

1980-02-01

Experimental and analytical techniques have been developed for analysis and characterization of delayed-neutron (DN) signals that can provide diagnostic information to augment data from cover-gas analyses in the detection and identification of breached elements in an LMFBR. Eleven flow-reduction tests have been run in EBR-II to provide base data support for predicting DN signal characteristics during exposed-fuel operation. Results from the tests demonstrate the feasibility and practicability of response-analysis techniques for determining (a) the transit time, T/sub tr/, for DN emitters traveling from the core to the detector and (b) the isotropic holdup time, T/sub h/, of DN precursors in the fuel element

Concept and development of information flow diagram for literature survey

International Nuclear Information System (INIS)

Noda, Masaru; Sato, Shoko; Ueda, Tadashi; Tsuchi, Hiroyuki; Koike, Akihisa

2007-01-01

The Information Flow Diagram for Literature Survey (IFDLS) has been developed to manage information and procedure in the literature survey phase of the PTAs selection process. It is a tool utilizing information technology, which can organize, analyze, and evaluate information from literature survey and manage their process systematically. IFDLS is able to show the flow of information and data, and the history of information management processing. Information coverage and quality is not homogenous throughout the country and, in some areas, there may not even be sufficient data available to be able to reach a judgment on conformity with the site-specific evaluation factors (SSEF). Literature surveys could only be conducted on a volunteer area before it is nominated as a PIA. However, the absence of information on any factor mentioned will not constitute disqualification of the area. On the contrary, an attempt to compare these sites with analogous areas in Japan will be done to assemble sufficient data and consequently make a decision on whether to proceed further. The application of IFDLS to literature survey phase of the PIA selection process is being proposed. The concept, construction, application and evolution of IFDLS towards application phase on a trial basis are discussed. (authors)

UAS Air Traffic Controller Acceptability Study. 2; Evaluating Detect and Avoid Technology and Communication Delays in Simulation

Science.gov (United States)

Comstock, James R., Jr.; Ghatas, Rania W.; Consiglio, Maria C.; Chamberlain, James P.; Hoffler, Keith D.

2015-01-01

This study evaluated the effects of communications delays and winds on air traffic controller ratings of acceptability of horizontal miss distances (HMDs) for encounters between Unmanned Aircraft Systems (UAS) and manned aircraft in a simulation of the Dallas-Ft. Worth (DFW) airspace. Fourteen encounters per hour were staged in the presence of moderate background traffic. Seven recently retired controllers with experience at DFW served as subjects. Guidance provided to the UAS pilots for maintaining a given HMD was provided by information from Detect and Avoid (DAA) self-separation algorithms (Stratway+) displayed on the Multi-Aircraft Control System. This guidance consisted of amber "bands" on the heading scale of the UAS navigation display indicating headings that would result in a loss of well clear between the UAS and nearby traffic. Winds tested were successfully handled by the DAA algorithms and did not affect the controller acceptability ratings of the HMDs. Voice communications delays for the UAS were also tested and included one-way delay times of 0, 400, 1200, and 1800 msec. For longer communications delays, there were changes in strategy and communications flow that were observed and reported by the controllers. The aim of this work is to provide useful information for guiding future rules and regulations applicable to flying UAS in the NAS. Information from this study will also be of value to the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 - Minimum Performance Standards for UAS.

A Simple CPS Transformation of Control-Flow Information

DEFF Research Database (Denmark)

Damian, Daniel; Danvy, Olivier

2002-01-01

We build on Danvy and Nielsen's first-order program transformation into continuation-passing style (CPS) to design a new CPS transformation of flow information that is simpler and more efficient than what has been presented in previous work. The key to simplicity and efficiency is that our CPS tr...

Breaking down the silos to decrease internal diversions and patient flow delays.

Science.gov (United States)

Driscoll, Molly; Tobis, Kristen; Gurka, David; Serafin, Frederick; Carlson, Elizabeth

2015-01-01

Hospitals strive to admit patients to the units where caregiver competencies align with the patient's condition. When the hospital's census peaks, internal diversions and the associated risks increase, which are intensified when silos exist, as segregated care negatively impacts collaboration and patient safety. In this study, a 600+-bed academic, tertiary care specialty hospital experienced an increase in internal diversions. Within the neuroscience service line, emergent neuroscience transfers from outside hospitals had been declined or internally diverted because of capacity limitations. Formalized processes for improving collaboration between health care providers related to capacity issues were required to decrease internal diversions and improve patient flow and patient safety. A pilot project was conducted on neuroscience units during a process improvement initiative. A hospital-wide internal diversion plan was developed, identifying primary and secondary placement options for all patients requiring hospitalization to support patient flow and patient safety. Forecasting tools were developed to provide units' leadership with current information on expected admissions. Daily capacity huddles were instituted to increase collaboration between patient care units. The interventions trialed during the pilot decreased internal diversions and improved patient flow. The improved collaboration resulted in an 80% decrease in declinations of emergent intensive care unit transfers from outside hospitals due to capacity limitations and a 50% decrease in the number of these patients being internally diverted to alternate intensive care units. The interventions implemented minimized internal diversions and improved patient flow. The transparency of the patient placement process led to an increased collaboration between all participants.

DEVELOPING AND PROPOSING A CONCEPTUAL MODEL OF THE FLOW EXPERIENCE DURING ONLINE INFORMATION SEARCH

Directory of Open Access Journals (Sweden)

Lazoc Alina

2012-07-01

Full Text Available Information search is an essential part of the consumer`s decision making process. The online medium offers new opportunities and challenges for information search activities (in and outside the marketing context. We are interested in the way human information experiences and behaviors are affected by this. Very often online games and social web activities are perceived as challenging, engaging and enjoyable, while online information search is far below this evaluation. Our research proposal implies that using the online medium for information search may provoke enjoyable experiences through the flow state, which may in turn positively influence an individual`s exploratory information behavior and encourage his/her pro-active market behavior. The present study sets out to improve the understanding of the online medium`s impact on human`s exploratory behavior. We hypothesize that the inclusion of the online flow experience in our research model will better explain exploratory information search behaviors. A 11-component conceptual framework is proposed to explain the manifestations of flow, its personal and technological determinants and its behavioral consequence in the context of online information search. Our research has the primary purpose to present an integrated online flow model. Its secondary objective is to stimulate extended research in the area of informational behaviors in the digital age. The paper is organized in three sections. In the first section we briefly report the analysis results of the most relevant online flow theory literature and, drawing on it, we are trying to identify variables and relationships among these. In the second part we propose a research model and use prior flow models to specify a range of testable hypothesis. Drawing on the conceptual model developed, the last section of our study presents the final conclusions and proposes further steps in evaluating the model`s validity. Future research directions

A Neuroeconomics Analysis of Investment Process with Money Flow Information: The Error-Related Negativity

Directory of Open Access Journals (Sweden)

Cuicui Wang

2015-01-01

Full Text Available This investigation is among the first ones to analyze the neural basis of an investment process with money flow information of financial market, using a simplified task where volunteers had to choose to buy or not to buy stocks based on the display of positive or negative money flow information. After choosing “to buy” or “not to buy,” participants were presented with feedback. At the same time, event-related potentials (ERPs were used to record investor’s brain activity and capture the event-related negativity (ERN and feedback-related negativity (FRN components. The results of ERN suggested that there might be a higher risk and more conflict when buying stocks with negative net money flow information than positive net money flow information, and the inverse was also true for the “not to buy” stocks option. The FRN component evoked by the bad outcome of a decision was more negative than that by the good outcome, which reflected the difference between the values of the actual and expected outcome. From the research, we could further understand how investors perceived money flow information of financial market and the neural cognitive effect in investment process.

A Neuroeconomics Analysis of Investment Process with Money Flow Information: The Error-Related Negativity

Science.gov (United States)

Wang, Cuicui; Vieito, João Paulo; Ma, Qingguo

2015-01-01

This investigation is among the first ones to analyze the neural basis of an investment process with money flow information of financial market, using a simplified task where volunteers had to choose to buy or not to buy stocks based on the display of positive or negative money flow information. After choosing “to buy” or “not to buy,” participants were presented with feedback. At the same time, event-related potentials (ERPs) were used to record investor's brain activity and capture the event-related negativity (ERN) and feedback-related negativity (FRN) components. The results of ERN suggested that there might be a higher risk and more conflict when buying stocks with negative net money flow information than positive net money flow information, and the inverse was also true for the “not to buy” stocks option. The FRN component evoked by the bad outcome of a decision was more negative than that by the good outcome, which reflected the difference between the values of the actual and expected outcome. From the research, we could further understand how investors perceived money flow information of financial market and the neural cognitive effect in investment process. PMID:26557139

Delay Variation Model with Two Service Queues

Directory of Open Access Journals (Sweden)

Filip Rezac

2010-01-01

Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

Delay functions in trip assignment for transport planning process

Science.gov (United States)

Leong, Lee Vien

2017-10-01

In transportation planning process, volume-delay and turn-penalty functions are the functions needed in traffic assignment to determine travel time on road network links. Volume-delay function is the delay function describing speed-flow relationship while turn-penalty function is the delay function associated to making a turn at intersection. The volume-delay function used in this study is the revised Bureau of Public Roads (BPR) function with the constant parameters, α and β values of 0.8298 and 3.361 while the turn-penalty functions for signalized intersection were developed based on uniform, random and overflow delay models. Parameters such as green time, cycle time and saturation flow were used in the development of turn-penalty functions. In order to assess the accuracy of the delay functions, road network in areas of Nibong Tebal, Penang and Parit Buntar, Perak was developed and modelled using transportation demand forecasting software. In order to calibrate the models, phase times and traffic volumes at fourteen signalised intersections within the study area were collected during morning and evening peak hours. The prediction of assigned volumes using the revised BPR function and the developed turn-penalty functions show close agreement to actual recorded traffic volume with the lowest percentage of accuracy, 80.08% and the highest, 93.04% for the morning peak model. As for the evening peak model, they were 75.59% and 95.33% respectively for lowest and highest percentage of accuracy. As for the yield left-turn lanes, the lowest percentage of accuracy obtained for the morning and evening peak models were 60.94% and 69.74% respectively while the highest percentage of accuracy obtained for both models were 100%. Therefore, can be concluded that the development and utilisation of delay functions based on local road conditions are important as localised delay functions can produce better estimate of link travel times and hence better planning for future

VOLUNTARY DISCLOSURE OF CASH FLOWS INFORMATION AND COMPANY'S CHARACTERISTICS: EVIDENCE FROM THE CROATIAN CAPITAL MARKET

Directory of Open Access Journals (Sweden)

Željana Aljinović Barać

2012-12-01

Full Text Available This paper focuses on the voluntary disclosure of cash flows information of Croatian large companies whose shares are listed on the Zagreb Stock Exchange, with the aim to identify characteristics of companies that provide extensive disclosures. In order to conduct the research and test the likelihood that company publicly announces wealth of information about cash flows, three groups of company’s features are defined as variables: accounting data, capital market information and company’s qualitative characteristics. Verification of empirical evidence was provided through the sample of Croatian listed companies using logistic regression analysis. Obtained results indicate that despite the desire of the regulatory authorities that capital market investors receive all relevant information, companies voluntarily disclose information about cash flows very rarely. Those companies are young (i.e. their shares are listed on an organized securities market for a short time and profitable, with growing net income and growing cash flow from operating activities and usually use indirect method for operating cash flow report. The provision of features of Croatian companies that voluntary disclose cash flow information can be found as contribution of our research, because this topic in a cases of macro-oriented accounting system economies, i.e. bank oriented economies with emerging capital market is still unexplored.

Fusion Kalman filtration with k-step delay sharing pattern

Directory of Open Access Journals (Sweden)

Duda Zdzisław

2015-09-01

Full Text Available A fusion hierarchical state filtration with k−step delay sharing pattern for a multisensor system is considered. A global state estimate depends on local state estimates determined by local nodes using local information. Local available information consists of local measurements and k−step delay global information - global estimate sent from a central node. Local estimates are transmitted to the central node to be fused. The synthesis of local and global filters is presented. It is shown that a fusion filtration with k−step delay sharing pattern is equivalent to the optimal centralized classical Kalman filtration when local measurements are transmitted to the center node and used to determine a global state estimate. It is proved that the k−step delay sharing pattern can reduce covariances of local state errors.

Mixing-induced quantum non-Markovianity and information flow

Science.gov (United States)

Breuer, Heinz-Peter; Amato, Giulio; Vacchini, Bassano

2018-04-01

Mixing dynamical maps describing open quantum systems can lead from Markovian to non-Markovian processes. Being surprising and counter-intuitive, this result has been used as argument against characterization of non-Markovianity in terms of information exchange. Here, we demonstrate that, quite the contrary, mixing can be understood in a natural way which is fully consistent with existing theories of memory effects. In particular, we show how mixing-induced non-Markovianity can be interpreted in terms of the distinguishability of quantum states, system-environment correlations and the information flow between system and environment.

Nonlinear delay monopoly with bounded rationality

International Nuclear Information System (INIS)

Matsumoto, Akio; Szidarovszky, Ferenc

2012-01-01

The purpose of this paper is to study the dynamics of a monopolistic firm in a continuous-time framework. The firm is assumed to be boundedly rational and to experience time delays in obtaining and implementing information on output. The dynamic adjustment process is based on the gradient of the expected profit. The paper is divided into three parts: we examine delay effects on dynamics caused by one-time delay and two-time delays in the first two parts. Global dynamics and analytical results on local dynamics are numerically confirmed in the third part. Four main results are demonstrated. First, the stability switch from stability to instability occurs only once in the case of a single delay. Second, the alternation of stability and instability can continue if two time delays are involved. Third, the occurence of Hopf bifurcation is analytically shown if stability is lost. Finally, in a bifurcation process, there are a period-doubling cascade to chaos and a period-halving cascade to the equilibrium point in the case of two time delays if the difference between the two delays is large.

Predictive Flow Control to Minimize Convective Time Delays

Science.gov (United States)

2013-08-19

external flows around air vehicles or ground based systems such as bridges and buildings, internal flows in pipes and propulsion systems, acoustical...3437, 1977. [4] Bridges , D. H., "The Asymmetric Vortex Wake Problem - Asking the Right Question," A/AA Paper 2006-3553, 2006. [5) Deng, X. Y., Tian, W...Aircraft, Vol. 42, No. 2, 2003, pp. 42~23. [8] Darden, L. and Komerath, N., "Forebody Vortex Control at High Incidence using a Moveable Nose Stagnation

Information related to postal flows and big data analysis potential. The case of Spain

Energy Technology Data Exchange (ETDEWEB)

Martinez Alvaro, O.; Nuñez Gonzalez, A.

2016-07-01

National Post Offices manage huge volumes of letters and parcels. Data associated to these flows are growing fast, with a great variety related to the diversity of postal products. The research described in this paper has classified all information flows of Correos, the Spanish National Post Office. In spite of the complexity of the current postal service portfolio, only four categories of matrices allow the classification of all postal information flows. Thanks to the migration towards new products, analyses with simple techniques will provide more and better information in the future, due to the structured nature of existing databases. (Author)

A novel perspective to calibrate temporal delays in cerebrovascular reactivity using hypercapnic and hyperoxic respiratory challenges.

Science.gov (United States)

Champagne, Allen A; Bhogal, Alex A; Coverdale, Nicole S; Mark, Clarisse I; Cook, Douglas J

2017-12-05

Redistribution of blood flow across different brain regions, arising from the vasoactive nature of hypercapnia, can introduce errors when examining cerebrovascular reactivity (CVR) response delays. In this study, we propose a novel analysis method to characterize hemodynamic delays in the blood oxygen level dependent (BOLD) response to hypercapnia, and hyperoxia, as a way to provide insight into transient differences in vascular reactivity between cortical regions, and across tissue depths. A pseudo-continuous arterial spin labeling sequence was used to acquire BOLD and cerebral blood flow simultaneously in 19 healthy adults (12 F; 20 ± 2 years) during boxcar CO 2 and O 2 gas inhalation paradigms. Despite showing distinct differences in hypercapnia-induced response delay times (P  0.05) once calibrated for bolus arrival time derived using non-vasoactive hyperoxic gas challenges. Longer hypercapnic temporal delays were observed as the depth of the white matter tissue increased, although no significant differences in response lag were found during hyperoxia across tissue depth, or between grey and white matter. Furthermore, calibration of hypercapnic delays using hyperoxia revealed that deeper white matter layers may be more prone to dynamic redistribution of blood flow, which introduces response lag times ranging between 1 and 3 s in healthy subjects. These findings suggest that the combination of hypercapnic and hyperoxic gas-inhalation MRI can be used to distinguish between differences in CVR that arise as a result of delayed stimulus arrival time (due to the local architecture of the cerebrovasculature), or preferential blood flow distribution. Calibrated response delays to hypercapnia provide important insights into cerebrovascular physiology, and may be used to correct response delays associated with vascular impairment. Copyright © 2017. Published by Elsevier Inc.

Quantifying Information Flow During Emergencies

Science.gov (United States)

Gao, Liang; Song, Chaoming; Gao, Ziyou; Barabási, Albert-László; Bagrow, James P.; Wang, Dashun

2014-02-01

Recent advances on human dynamics have focused on the normal patterns of human activities, with the quantitative understanding of human behavior under extreme events remaining a crucial missing chapter. This has a wide array of potential applications, ranging from emergency response and detection to traffic control and management. Previous studies have shown that human communications are both temporally and spatially localized following the onset of emergencies, indicating that social propagation is a primary means to propagate situational awareness. We study real anomalous events using country-wide mobile phone data, finding that information flow during emergencies is dominated by repeated communications. We further demonstrate that the observed communication patterns cannot be explained by inherent reciprocity in social networks, and are universal across different demographics.

The comparing results of carcinoma between three-phase and delayed whole body bone scan

International Nuclear Information System (INIS)

Si Hongwei; Li Xianfeng

2004-01-01

Purpose: Three phase bone scan is an imaging technology in nuclear medicine, which composed of blood flow phase, blood pool phase and delayed phase and the last one is often performed in routine works in department of nuclear medicine. The purpose of this study is to evaluate the merit of three-phase bone scan.Methods: In this study, we chose 54 patients who were having an regional pain which caused by benign or malignant carcinoma that diagnosed by CT, X-ray, ECT, MRI or other examinations. The imaging were acquired simultaneously from both anterior and posterior views, after a bolus injection of 1110 MBq technetium-99m-labelled methylene diphosphonate (MDP), blood phase contains 20 frame sand 3 seconds per frame, blood pool phase contains 5 frames and 1 minute per frame, delayed phase was performed 2.5 hour later. According to the results of three-phase bone scan, the patients were divided into 2 groups: normal and abnormal groups. The abnormal group includes early phase positive,delay positive and all three phase positive sets. The comparing among the 3 sets were analyzed by chi-square test and other statistic means.Results: There were 54 patients who had suffered lung cancer, breast cancer and other cancer,involved in this study, 34 males and 20 females, ranged age 17 to 88 years, were normal in 15 cases,positive in 22 cases, the results in delayed phase were positive in 9 cases, blood flow and blood pool phase showed blood flow changes in 4 cases and soft tissue tumors were seen in 4 cases. Three phase bone scan was more sensitive than delayed whole body bone scan in detecting the abnormal sites (p 0.05) The sensitivity of detecting tumors in blood flow and blood pool phase,delayed phase were respectively lower than in three phase bone scan (p<0.001).Conclusion: It is more sensitivity of detecting tumor lesions in three phase bone scan than in delayed phase whole body bone scan and the changes of blood flow and soft tissue can be seen in three phase bone scan

Reentrant Information Flow in Electrophysiological Rat Default Mode Network.

Science.gov (United States)

Jing, Wei; Guo, Daqing; Zhang, Yunxiang; Guo, Fengru; Valdés-Sosa, Pedro A; Xia, Yang; Yao, Dezhong

2017-01-01

Functional MRI (fMRI) studies have demonstrated that the rodent brain shows a default mode network (DMN) activity similar to that in humans, offering a potential preclinical model both for physiological and pathophysiological studies. However, the neuronal mechanism underlying rodent DMN remains poorly understood. Here, we used electrophysiological data to analyze the power spectrum and estimate the directed phase transfer entropy (dPTE) within rat DMN across three vigilance states: wakeful rest (WR), slow-wave sleep (SWS), and rapid-eye-movement sleep (REMS). We observed decreased gamma powers during SWS compared with WR in most of the DMN regions. Increased gamma powers were found in prelimbic cortex, cingulate cortex, and hippocampus during REMS compared with WR, whereas retrosplenial cortex showed a reverse trend. These changed gamma powers are in line with the local metabolic variation of homologous brain regions in humans. In the analysis of directional interactions, we observed well-organized anterior-to-posterior patterns of information flow in the delta band, while opposite patterns of posterior-to-anterior flow were found in the theta band. These frequency-specific opposite patterns were only observed in WR and REMS. Additionally, most of the information senders in the delta band were also the receivers in the theta band, and vice versa. Our results provide electrophysiological evidence that rat DMN is similar to its human counterpart, and there is a frequency-dependent reentry loop of anterior-posterior information flow within rat DMN, which may offer a mechanism for functional integration, supporting conscious awareness.

Case Flow Management: A Format for Making Change

Directory of Open Access Journals (Sweden)

Kerry Connelly

2009-08-01

Full Text Available At the International Association for Court Administration (IACA Conference in 2008 in Dublin Barry Mahoney, President Emeritus, Justice Management Institute did an excellent job at presenting some of the major sources of delay in case processing. He identified both case-specific and systemic factors. He also identified the goals of case flow management. I was impressed by the thoroughness and succinctness of what he was presenting. On my way back home I thought about how I might present the same information to my judges and court staff and how the information might be used to make positive changes in one of my courts. The following is a description of what took place at our one-day workshop on felony case management, and the positive results we obtained in working with judges, court staff and our justice partners. The process described below identified specific barriers to case processing and resulted in the development of workable solutions to case delay.

49 CFR 831.13 - Flow and dissemination of accident or incident information.

Science.gov (United States)

2010-10-01

... dissemination of accident or incident information. (a) Release of information during the field investigation... 49 Transportation 7 2010-10-01 2010-10-01 false Flow and dissemination of accident or incident information. 831.13 Section 831.13 Transportation Other Regulations Relating to Transportation (Continued...

Entanglement revive and information flow within the decoherent environment.

Science.gov (United States)

Shi, Jia-Dong; Wang, Dong; Ye, Liu

2016-08-10

In this paper, the dynamics of entanglement is investigated in the presence of a noisy environment. We reveal its revival behavior and probe the mechanisms of this behavior via an information-theoretic approach. By analyzing the correlation distribution and the information flow within the composite system including the qubit subsystem and a noisy environment, it has been found that the subsystem-environment coupling can induce the quasi-periodic entanglement revival. Furthermore, the dynamical relationship among tripartite correlations, bipartite entanglement and local state information is explored, which provides a new insight into the non-Markovian mechanisms during the evolution.

Contralateral delay activity tracks object identity information in visual short term memory.

Science.gov (United States)

Gao, Zaifeng; Xu, Xiaotian; Chen, Zhibo; Yin, Jun; Shen, Mowei; Shui, Rende

2011-08-11

Previous studies suggested that ERP component contralateral delay activity (CDA) tracks the number of objects containing identity information stored in visual short term memory (VSTM). Later MEG and fMRI studies implied that its neural source lays in superior IPS. However, since the memorized stimuli in previous studies were displayed in distinct spatial locations, hence possibly CDA tracks the object-location information instead. Moreover, a recent study implied the activation in superior IPS reflected the location load. The current research thus explored whether CDA tracks the object-location load or the object-identity load, and its neural sources. Participants were asked to remember one color, four identical colors or four distinct colors. The four-identical-color condition was the critical one because it contains the same amount of identity information as that of one color while the same amount of location information as that of four distinct colors. To ensure the participants indeed selected four colors in the four-identical-color condition, we also split the participants into two groups (low- vs. high-capacity), analyzed late positive component (LPC) in the prefrontal area, and collected participant's subjective-report. Our results revealed that most of the participants selected four identical colors. Moreover, regardless of capacity-group, there was no difference on CDA between one color and four identical colors yet both were lower than 4 distinct colors. Besides, the source of CDA was located in the superior parietal lobule, which is very close to the superior IPS. These results support the statement that CDA tracks the object identity information in VSTM. Copyright © 2011 Elsevier B.V. All rights reserved.

Novel Methods for Measuring Depth of Anesthesia by Quantifying Dominant Information Flow in Multichannel EEGs

Directory of Open Access Journals (Sweden)

Kab-Mun Cha

2017-01-01

Full Text Available In this paper, we propose novel methods for measuring depth of anesthesia (DOA by quantifying dominant information flow in multichannel EEGs. Conventional methods mainly use few EEG channels independently and most of multichannel EEG based studies are limited to specific regions of the brain. Therefore the function of the cerebral cortex over wide brain regions is hardly reflected in DOA measurement. Here, DOA is measured by the quantification of dominant information flow obtained from principle bipartition. Three bipartitioning methods are used to detect the dominant information flow in entire EEG channels and the dominant information flow is quantified by calculating information entropy. High correlation between the proposed measures and the plasma concentration of propofol is confirmed from the experimental results of clinical data in 39 subjects. To illustrate the performance of the proposed methods more easily we present the results for multichannel EEG on a two-dimensional (2D brain map.

Airport Network Flow Simulator

Science.gov (United States)

1978-10-01

The Airport Network Flow Simulator is a FORTRAN IV simulation of the flow of air traffic in the nation's 600 commercial airports. It calculates for any group of selected airports: (a) the landing and take-off (Type A) delays; and (b) the gate departu...

Analysis and improvement measures of flight delay in China

Science.gov (United States)

Zang, Yuhang

2017-03-01

Firstly, this paper establishes the principal component regression model to analyze the data quantitatively, based on principal component analysis to get the three principal component factors of flight delays. Then the least square method is used to analyze the factors and obtained the regression equation expression by substitution, and then found that the main reason for flight delays is airlines, followed by weather and traffic. Aiming at the above problems, this paper improves the controllable aspects of traffic flow control. For reasons of traffic flow control, an adaptive genetic queuing model is established for the runway terminal area. This paper, establish optimization method that fifteen planes landed simultaneously on the three runway based on Beijing capital international airport, comparing the results with the existing FCFS algorithm, the superiority of the model is proved.

Traffic Scheduling in WDM Passive Optical Network with Delay Guarantee

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

WDM passive optical network becomes more favorable as the required bandwidth increases, but currently few media access control algorithms adapted to WDM access network. This paper presented a new scheduling algorithm for bandwidth sharing in WDM passive optical networks, which provides per-flow delay guarantee and supports variable-length packets scheduling. Through theoretical analysis and simulation, the end-to-end delay bound and throughput fairness of the algorithm was demonstrated.

The Obstacles Facing the Flow of the Electronic Information in the Arab World

Directory of Open Access Journals (Sweden)

Samir Yahya Umri

2006-12-01

Full Text Available This research views the most important obstacles facing the flow of electronic information in Arab world; with an illustration about the effect of each obstacle on the flowing of the information, and the special recommendation to overcome it. the research states 4 main obstacles; they are: number of internet users and the weakness of the infrastructure in our Arab world, the spam e-mails, the Bugs and vulnerabilities in the operating systems that allow hackers to attack the information systems, and the spread of the electronic pornography on the internet

The impact of delaying an investment decision on R&D projects in real option game

International Nuclear Information System (INIS)

Chang, Shuhua; Li, Yue; Gao, Fanglu

2016-01-01

In a research and development (R&D) investment, the cost and the project value of such an investment are usually uncertain, which thus increases its complexity. Correspondingly, the NPV (Net Present Value) rule fails to evaluate the value of this project exactly, because this method does not take into account the market uncertainty, irreversibility of investment and ability of delay entry. In this paper, we employ the real option theory to evaluate the project value of a R&D investment. Since the cost of a R&D investment is very high and the flow of the information is crowded, an investor cannot make an immediate decision every time. So, the proposed real option model is an exchange option. At the same time, combining the real option and the game theory, we can find the Nash equilibrium which is the optimal strategy. Moreover, we also study how the delayed time influences the price of the project investment and how the different delayed times effect the choice of the optimal strategies.

Delay propagation and process management at railway stations

NARCIS (Netherlands)

Goverde, R.M.P.; Hansen, I.A.

2001-01-01

Process operators at large railway stations have the difficult task to secure a fluent train traffic flow while minimizing deviations from established timetables. Variation in actual train departure times is inevitable due to many circumstances such as arrival delays and fluctuations in alighting

Delayed child-bearing.

Science.gov (United States)

Johnson, Jo-Ann; Tough, Suzanne

2012-01-01

To provide an overview of delayed child-bearing and to describe the implications for women and health care providers. Delayed child-bearing, which has increased greatly in recent decades, is associated with an increased risk of infertility, pregnancy complications, and adverse pregnancy outcome. This guideline provides information that will optimize the counselling and care of Canadian women with respect to their reproductive choices. Maternal age is the most important determinant of fertility, and obstetric and perinatal risks increase with maternal age. Many women are unaware of the success rates or limitations of assisted reproductive technology and of the increased medical risks of delayed child-bearing, including multiple births, preterm delivery, stillbirth, and Caesarean section. This guideline provides a framework to address these issues. Studies published between 2000 and August 2010 were retrieved through searches of PubMed and the Cochrane Library using appropriate key words (delayed child-bearing, deferred pregnancy, maternal age, assisted reproductive technology, infertility, and multiple births) and MeSH terms (maternal age, reproductive behaviour, fertility). The Internet was also searched using similar key words, and national and international medical specialty societies were searched for clinical practice guidelines and position statements. Data were extracted based on the aims, sample, authors, year, and results. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). The Society of Obstetricians and Gynaecologists of Canada. RECOMMENDATIONS 1. Women who delay child-bearing are at increased risk of infertility. Prospective parents, especially women, should know that their fecundity and fertility begin to decline significantly after 32 years of age. Prospective parents should know that assisted reproductive technologies cannot guarantee a live birth or completely

Event-Triggered Control for Multiagent Systems with the Problem of Packet Losses and Communication Delays When Using the Second-Order Neighbors’ Information

Directory of Open Access Journals (Sweden)

Chuan Yan

2014-01-01

Full Text Available This paper mainly investigates the event-triggered control for discrete-time multiagent systems with the problem of packet losses and communication delays when both the first-order and the second-order neighbors’ information are used. Event-triggered control laws are adopted so as to reduce the frequency of individual actuation updating under the sampled-data framework for discrete-time agent dynamics. The communication graph is undirected and the loss of data across each communication link occurs at certain probability, which is governed by a Bernoulli process. It is found that the distributed consensus speeds up by using the second-order neighbors’ information when packet losses and communication delays occur. Numerical examples are given to demonstrate the effectiveness of the proposed methods.

Information flow security for business process models - just one click away

NARCIS (Netherlands)

Lehmann, A.; Fahland, D.; Lohmann, N.; Moser, S.

2012-01-01

When outsourcing tasks of a business process to a third party, information flow security becomes a critical issue. In particular implicit information leaks are an intriguing problem. Given a business process one could ask whether the execution of a confidential task is kept secret to a third party

On the Impact of information access delays on remote control of a wind turbine

DEFF Research Database (Denmark)

Madsen, Jacob Theilgaard; Barradas Berglind, Jose de Jesus; Madsen, Tatiana Kozlova

2015-01-01

farm controller. The controller attempts to reduce fatigue on the wind turbine, which is used as a measure of the controller performance. Via simulation analysis, we show the degradation of the controller performance when subject to network delays. We analyse different access strategies useable...... by the controller to gather sensor information and and quantitatively characterize the impact of these access strategies on the controller performance......It is important to reduce the impact of renewable production in the power grid by means of control, due to increased frequency deviations and imbalances caused by these assets. Cost efficient deployment of asset control frequently results in a distributed control architecture where the controller...

Hopf Bifurcation of a Delayed Epidemic Model with Information Variable and Limited Medical Resources

Directory of Open Access Journals (Sweden)

Caijuan Yan

2014-01-01

Full Text Available We consider SIR epidemic model in which population growth is subject to logistic growth in absence of disease. We get the condition for Hopf bifurcation of a delayed epidemic model with information variable and limited medical resources. By analyzing the corresponding characteristic equations, the local stability of an endemic equilibrium and a disease-free equilibrium is discussed. If the basic reproduction ratio ℛ01, we obtain sufficient conditions under which the endemic equilibrium E* of system is locally asymptotically stable. And we also have discussed the stability and direction of Hopf bifurcations. Numerical simulations are carried out to explain the mathematical conclusions.

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

DEFF Research Database (Denmark)

Salmistraro, Matteo; Forchhammer, Søren

2012-01-01

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

ELABORATING A MEASUREMENT INSTRUMENT FOR THE FLOW EXPERIENCE DURING ONLINE INFORMATION SEARCH

Directory of Open Access Journals (Sweden)

Caraivan Luiza

2012-12-01

Full Text Available Flow is a construct imported in marketing research from social sciences in order to examine consumer behavior in the online medium. The construct describes a state of deep involvement in a challenging activity, most frequently characterized by high levels of enjoyment, control and concentration. Researchers found that the degree to which online experience is challenging can be defined, measured, and related well to important marketing variables. As shown by our extensive literature review, flow measurements include antecedents, dimensions and consequences of flow. The present paper represents a detailed description of the construct`s operationalization in the context of online information search. In this respect, our main goal is to produce a basic instrument to evaluate the flow experience of online search, in order to capitalize on the premises of an interactive, complex informational medium – the World Wide Web – and on the consequence of an exploratory informational behavior of users. The instrument is conceived to offer a primal possibility to collect data. The composition, source and significance of the 11 scales used to measure the multiple factors of the flow experience during online search are detailed in this study with the aim to ensure the compliance with scientific rigors and to facilitate correct reports of data related to the reliability and validity of measurements. For further research, we propose factor analysis to test the resulted instrument and to ensure that the measures employed are psychometrically sound. Factor analysis refers to a wide range of statistic techniques used to represent a set of variables in concordance with a reduced number of hypothetical variables called factors. Factorial analysis is used to solve two types of problems: reducing the number of variables to increase data processing speed and identifying hidden patterns in the existent data relations. However, we expect our scales to perform

Novel Resuscitation from Lethal Hemorrhage - Suspended Animation for Delayed Resuscitation

National Research Council Canada - National Science Library

Safar, Peter

2002-01-01

.... We have conceived and documented "suspended animation for delayed resuscitation" with the use of hypothermic saline flush into the aorta within the first 5 minute of no blood flow, using novel...

A flood-based information flow analysis and network minimization method for gene regulatory networks.

Science.gov (United States)

Pavlogiannis, Andreas; Mozhayskiy, Vadim; Tagkopoulos, Ilias

2013-04-24

Biological networks tend to have high interconnectivity, complex topologies and multiple types of interactions. This renders difficult the identification of sub-networks that are involved in condition- specific responses. In addition, we generally lack scalable methods that can reveal the information flow in gene regulatory and biochemical pathways. Doing so will help us to identify key participants and paths under specific environmental and cellular context. This paper introduces the theory of network flooding, which aims to address the problem of network minimization and regulatory information flow in gene regulatory networks. Given a regulatory biological network, a set of source (input) nodes and optionally a set of sink (output) nodes, our task is to find (a) the minimal sub-network that encodes the regulatory program involving all input and output nodes and (b) the information flow from the source to the sink nodes of the network. Here, we describe a novel, scalable, network traversal algorithm and we assess its potential to achieve significant network size reduction in both synthetic and E. coli networks. Scalability and sensitivity analysis show that the proposed method scales well with the size of the network, and is robust to noise and missing data. The method of network flooding proves to be a useful, practical approach towards information flow analysis in gene regulatory networks. Further extension of the proposed theory has the potential to lead in a unifying framework for the simultaneous network minimization and information flow analysis across various "omics" levels.

Travel Times, Congestion Levels, and Delays at Intersections Calculated on the Basis of Floating Car Data

DEFF Research Database (Denmark)

Lahrmann, Harry; Torp, Kristian

2010-01-01

Traditionally, the mapping of flow rate in a road network has been based on spot and intersection counting. Using these counting techniques, detailed information about traffic at a few well-picked spots in the road network is obtained. However, these techniques give no exact information about tra...... of the cars. This paper presents a method to determine travel time, congestion levels and delays using GPS data from moving vehicles – the so-called floating car data....... traffic only a few meters away from the measuring spots. The situation is totally the opposite when it comes to log data from GPS receivers in cars. Here detailed information about individual cars in the entire road network is obtained. However, the GPS data is only available from a small subset...

Delay-enhanced coherence of spiral waves in noisy Hodgkin-Huxley neuronal networks

International Nuclear Information System (INIS)

Wang Qingyun; Perc, Matjaz; Duan Zhisheng; Chen Guanrong

2008-01-01

We study the spatial dynamics of spiral waves in noisy Hodgkin-Huxley neuronal ensembles evoked by different information transmission delays and network topologies. In classical settings of coherence resonance the intensity of noise is fine-tuned so as to optimize the system's response. Here, we keep the noise intensity constant, and instead, vary the length of information transmission delay amongst coupled neurons. We show that there exists an intermediate transmission delay by which the spiral waves are optimally ordered, hence indicating the existence of delay-enhanced coherence of spatial dynamics in the examined system. Additionally, we examine the robustness of this phenomenon as the diffusive interaction topology changes towards the small-world type, and discover that shortcut links amongst distant neurons hinder the emergence of coherent spiral waves irrespective of transmission delay length. Presented results thus provide insights that could facilitate the understanding of information transmission delay on realistic neuronal networks

A model for integrating elementary neural functions into delayed-response behavior.

Directory of Open Access Journals (Sweden)

Thomas Gisiger

2006-04-01

Full Text Available It is well established that various cortical regions can implement a wide array of neural processes, yet the mechanisms which integrate these processes into behavior-producing, brain-scale activity remain elusive. We propose that an important role in this respect might be played by executive structures controlling the traffic of information between the cortical regions involved. To illustrate this hypothesis, we present a neural network model comprising a set of interconnected structures harboring stimulus-related activity (visual representation, working memory, and planning, and a group of executive units with task-related activity patterns that manage the information flowing between them. The resulting dynamics allows the network to perform the dual task of either retaining an image during a delay (delayed-matching to sample task, or recalling from this image another one that has been associated with it during training (delayed-pair association task. The model reproduces behavioral and electrophysiological data gathered on the inferior temporal and prefrontal cortices of primates performing these same tasks. It also makes predictions on how neural activity coding for the recall of the image associated with the sample emerges and becomes prospective during the training phase. The network dynamics proves to be very stable against perturbations, and it exhibits signs of scale-invariant organization and cooperativity. The present network represents a possible neural implementation for active, top-down, prospective memory retrieval in primates. The model suggests that brain activity leading to performance of cognitive tasks might be organized in modular fashion, simple neural functions becoming integrated into more complex behavior by executive structures harbored in prefrontal cortex and/or basal ganglia.

A model for integrating elementary neural functions into delayed-response behavior.

Science.gov (United States)

Gisiger, Thomas; Kerszberg, Michel

2006-04-01

It is well established that various cortical regions can implement a wide array of neural processes, yet the mechanisms which integrate these processes into behavior-producing, brain-scale activity remain elusive. We propose that an important role in this respect might be played by executive structures controlling the traffic of information between the cortical regions involved. To illustrate this hypothesis, we present a neural network model comprising a set of interconnected structures harboring stimulus-related activity (visual representation, working memory, and planning), and a group of executive units with task-related activity patterns that manage the information flowing between them. The resulting dynamics allows the network to perform the dual task of either retaining an image during a delay (delayed-matching to sample task), or recalling from this image another one that has been associated with it during training (delayed-pair association task). The model reproduces behavioral and electrophysiological data gathered on the inferior temporal and prefrontal cortices of primates performing these same tasks. It also makes predictions on how neural activity coding for the recall of the image associated with the sample emerges and becomes prospective during the training phase. The network dynamics proves to be very stable against perturbations, and it exhibits signs of scale-invariant organization and cooperativity. The present network represents a possible neural implementation for active, top-down, prospective memory retrieval in primates. The model suggests that brain activity leading to performance of cognitive tasks might be organized in modular fashion, simple neural functions becoming integrated into more complex behavior by executive structures harbored in prefrontal cortex and/or basal ganglia.

Anteseden Dan Konsekuensi Audit Delay Pada Perusahaan Perbankan Perioda 2011-2014

Directory of Open Access Journals (Sweden)

Ronald Tehupuring

2016-10-01

Full Text Available Timeliness in financial reporting can contribute to efficient performance for the stock market because it can reduce the asymmetry information, mitigate insider trading, and improve the usefulness decision of information to stakeholders. There were inconsistencies in prior research and the case of delay submission on issuer financial statements to the Financial Service Authority.  There were 30 cases for each in 2013 and 2014. This study aimed to examine (1 the negative impact between the company size, profitability, leverage, and the auditor quality on audit delay; (2 the positive impact of audit delay on audit switching; and (3 the positive impact of audit delay and audit delay switching on audit quality in banking companies listed on the Stock Exchange 2011-2014 period. A purposive sampling method is used and as the sample, 30 companies are obtained in four years so the analyzed data was based on 120 observations. The data analysis technique used is multiple linear and logistic regression. Results showed that (1 the size of the company and leverage have no impact on audit delay, while the return on assets and the auditor quality have a negative impact and significantly related to audit delay; (2 audit delay has a positive impact and significantly related to audit switching; (3 audit delay has a positive impact and significantly related to audit quality, while audit switching has no impact on audit quality. This study has contributed in optimizing timeliness performance of financial information reporting, effectiveness and efficiency of audit time range so that general  information increased, and The implication for audit quality of financial statements become more reliable.

An investigation of multitasking information behavior and the influence of working memory and flow

Science.gov (United States)

Alexopoulou, Peggy; Hepworth, Mark; Morris, Anne

2015-02-01

This study explored the multitasking information behaviour of Web users and how this is influenced by working memory, flow and Personal, Artefact and Task characteristics, as described in the PAT model. The research was exploratory using a pragmatic, mixed method approach. Thirty University students participated; 10 psychologists, 10 accountants and 10 mechanical engineers. The data collection tools used were: pre and post questionnaires, a working memory test, a flow state scale test, audio-visual data, web search logs, think aloud data, observation, and the critical decision method. All participants searched information on the Web for four topics: two for which they had prior knowledge and two more without prior knowledge. Perception of task complexity was found to be related to working memory. People with low working memory reported a significant increase in task complexity after they had completed information searching tasks for which they had no prior knowledge, this was not the case for tasks with prior knowledge. Regarding flow and task complexity, the results confirmed the suggestion of the PAT model (Finneran and Zhang, 2003), which proposed that a complex task can lead to anxiety and low flow levels as well as to perceived challenge and high flow levels. However, the results did not confirm the suggestion of the PAT model regarding the characteristics of web search systems and especially perceived vividness. All participants experienced high vividness. According to the PAT model, however, only people with high flow should experience high levels of vividness. Flow affected the degree of change of knowledge of the participants. People with high flow gained more knowledge for tasks without prior knowledge rather than people with low flow. Furthermore, accountants felt that tasks without prior knowledge were less complex at the end of the web seeking procedure than psychologists and mechanical engineers. Finally, the three disciplines appeared to differ

The Incremental Information Content of the Cash Flow Statement: An Australian Empirical Investigation

OpenAIRE

Hadri Kusuma

2014-01-01

The general objective of the present study is to investigate and assess the incremental information content of cash flow disclosures as required by the AASB 1026 ¡°Statement of Cash Flows¡±. This test addresses the issue of whether a change in cash flow components has the same relationship with security prices as that in earnings. Several previous studies indicate both income and cash flow statements may be mutually exclusive or mutually inclusive statements. The data to test three hypotheses...

Reducing communication delays and improving quality of care with a tuberculosis laboratory information system in resource poor environments: a cluster randomized controlled trial.

Science.gov (United States)

Blaya, Joaquín A; Shin, Sonya S; Yagui, Martin; Contreras, Carmen; Cegielski, Peter; Yale, Gloria; Suarez, Carmen; Asencios, Luis; Bayona, Jaime; Kim, Jihoon; Fraser, Hamish S F

2014-01-01

Lost, delayed or incorrect laboratory results are associated with delays in initiating treatment. Delays in treatment for Multi-Drug Resistant Tuberculosis (MDR-TB) can worsen patient outcomes and increase transmission. The objective of this study was to evaluate the impact of a laboratory information system in reducing delays and the time for MDR-TB patients to culture convert (stop transmitting). 78 primary Health Centers (HCs) in Lima, Peru. Participants lived within the catchment area of participating HCs and had at least one MDR-TB risk factor. The study design was a cluster randomized controlled trial with baseline data. The intervention was the e-Chasqui web-based laboratory information system. Main outcome measures were: times to communicate a result; to start or change a patient's treatment; and for that patient to culture convert. 1671 patients were enrolled. Intervention HCs took significantly less time to receive drug susceptibility test (DST) (median 11 vs. 17 days, Hazard Ratio 0.67 [0.62-0.72]) and culture (5 vs. 8 days, 0.68 [0.65-0.72]) results. The time to treatment was not significantly different, but patients in intervention HCs took 16 days (20%) less time to culture convert (p = 0.047). The eChasqui system reduced the time to communicate results between laboratories and HCs and time to culture conversion. It is now used in over 259 HCs covering 4.1 million people. This is the first randomized controlled trial of a laboratory information system in a developing country for any disease and the only study worldwide to show clinical impact of such a system. ClinicalTrials.gov NCT01201941.

Metropolises in the Twittersphere: An Informetric Investigation of Informational Flows and Networks

Directory of Open Access Journals (Sweden)

Thorsten Förster

2015-09-01

Full Text Available Information flows on social media platforms are able to show trends and user interests as well as connections between users. In this paper, we present a method how to analyze city related networks on the social media platform Twitter based on the user content. Forty million tweets have been downloaded via Twitter’s REST API (application programming interface and Twitter’s Streaming API. The investigation focuses on two aspects: firstly, trend detection has been done to analyze 31 informational world cities, according the user activity, popularity of shared websites and topics defined by hashtags. Secondly, a hint of how connected informational cities are to each other is given by creating a clustered network based on the number of connections between different city pairs. Tokyo, New York City, London and Paris clearly lead the ranking of the most active cities if compared by the total number of tweets. The investigation shows that Twitter is very frequently used to share content from other services like Instagram or YouTube. The most popular topics in tweets reveal great differences between the cities. In conclusion, the investigation shows that social media services like Twitter also can be a mirror of the society they are used in and bring to light information flows of connected cities in a global network. The presented method can be applied in further research to analyze information flows regarding specific topics and/or geographical locations.

Fractal analysis of intraflow unidirectional delay over w-lan and w-wan environments

OpenAIRE

Pezaros, D. P.; Sifalakis, M.; Mathy, Laurent

2007-01-01

We have analysed unidirectional delay traces of a diverse set of IPv6 microflows routed over W-LAN and W-WAN environments. Using a number of time-domain and frequency-domain estimators we have examined the existence and intensity of long-range dependence in packet delay when viewed as time-series data. The correlation structures of packet delay on bulk TCP data path and UDP flows follow asymptotic decay while Hurst exponent estimates suggest from moderate to strong intensity(H->1).

Evaluating delay factors in the construction and operation of port ...

African Journals Online (AJOL)

In Iran, between 30% and 40% of the total budget of the country `is allocated to this ... improper allocation of resources (24%), cash flows changes(28%), failure to ... Keywords: Delay Factors, Port Construction Projects, Project Management.

Investigation of relation between operator's mental workload and information flow in accident diagnosis tasks of nuclear power plant

International Nuclear Information System (INIS)

Ha, Chang Hoon; Kim, Jong Hyun; Seong, Poong Hyun

2004-01-01

In the main control room (MCR) of a nuclear power plant (NPP), there are lots of dynamic information sources for MCR operator's situation awareness. As the human-machine interface in MCR is advanced, operator's information acquisition, information gathering and decision-making is becoming an important part to maintain the effective and safe operation of NPPs. Diagnostic task in complex and huge systems like NPP is the most difficult and mental effort-demanding for operators. This research investigates the relation between operator's mental workload and information flow in accident diagnosis tasks. The amount of information flow is quantified, using information flow model and Conant's model, a kind of information theory. For the mental workload measure, eye blink rate, blink duration, fixation time, number of fixation, and gaze direction are measured during accident diagnosis tasks. Subjective methods such as NASA-Task Load Index (NASA-TLX) and Modified Cooper-Harper (MCH) method are also used in the experiment. It is shown that the operator's mental workload has significant relation to information flow of diagnosis task. It makes possible to predict the mental workload through the quantity of the information flow of a system

Smooth Information Flow in Temperature Climate Network Reflects Mass Transport

Czech Academy of Sciences Publication Activity Database

Hlinka, Jaroslav; Jajcay, Nikola; Hartman, David; Paluš, Milan

2017-01-01

Roč. 27, č. 3 (2017), č. článku 035811. ISSN 1054-1500 R&D Projects: GA ČR GCP103/11/J068; GA MŠk LH14001 Institutional support: RVO:67985807 Keywords : directed network * causal network * Granger causality * climate network * information flow * temperature network Subject RIV: IN - Informatics, Computer Science OBOR OECD: Computer sciences, information science, bioinformathics (hardware development to be 2.2, social aspect to be 5.8) Impact factor: 2.283, year: 2016

#FluxFlow: Visual Analysis of Anomalous Information Spreading on Social Media.

Science.gov (United States)

Zhao, Jian; Cao, Nan; Wen, Zhen; Song, Yale; Lin, Yu-Ru; Collins, Christopher

2014-12-01

We present FluxFlow, an interactive visual analysis system for revealing and analyzing anomalous information spreading in social media. Everyday, millions of messages are created, commented, and shared by people on social media websites, such as Twitter and Facebook. This provides valuable data for researchers and practitioners in many application domains, such as marketing, to inform decision-making. Distilling valuable social signals from the huge crowd's messages, however, is challenging, due to the heterogeneous and dynamic crowd behaviors. The challenge is rooted in data analysts' capability of discerning the anomalous information behaviors, such as the spreading of rumors or misinformation, from the rest that are more conventional patterns, such as popular topics and newsworthy events, in a timely fashion. FluxFlow incorporates advanced machine learning algorithms to detect anomalies, and offers a set of novel visualization designs for presenting the detected threads for deeper analysis. We evaluated FluxFlow with real datasets containing the Twitter feeds captured during significant events such as Hurricane Sandy. Through quantitative measurements of the algorithmic performance and qualitative interviews with domain experts, the results show that the back-end anomaly detection model is effective in identifying anomalous retweeting threads, and its front-end interactive visualizations are intuitive and useful for analysts to discover insights in data and comprehend the underlying analytical model.

Information flow among researchers at IPEN - Instituto de Pesquisas Energeticas e Nucleares

International Nuclear Information System (INIS)

Sugai, Mioka

1986-01-01

The information flow among a group of researchers at the Instituto de Pesquisas Energeticas e Nucleares of the Comissao Nacional de Energia Nuclear/Sao Paulo (IPEN-CNEN/SP) was analysed by means of a study of use and non-use of formal and informal information channels. The study proposed suggesting ideas for the improvement of the information network, as a means of contributing to the future planning of the information transfer structure among the I PEN technical-scientific community. A structural interview was used to collect the data. The researchers were characterized under functional, academic and professional aspects. Their information needs were identified as well as the factors which affect such needs. The researchers behaviour while searching for information was analysed by means of the critical incident technique. The informal communication networks were also identified according to a sociometric technique. The results show that in the Department included in the study, information flows equally through formal and informal channels. It is evident that there is a small correlation between degree of use and degree of importance of information sources. There is no evidence that those who make little use of formal channels supply their information needs by use of informal channels. It was patent that non-accessibility is the key factor which influences the non-use of information. The motivation of the use of formal sources is significantly inhibited by the fact that the library collection is not brought up-to-date. Relatively intense informal communication was verified both inter and intra-divisions. It is also evident that researchers with higher academic degree make more frequent use of formal channels, and stand a greater possibility of being identified as gatekeepers. However, those researchers who are considered more productive, at their present function, are not always those who make more frequent use of formal channels. The conclusions show that in order

Boarding is associated with higher rates of medication delays and adverse events but fewer laboratory-related delays.

Science.gov (United States)

Sri-On, Jiraporn; Chang, Yuchiao; Curley, David P; Camargo, Carlos A; Weissman, Joel S; Singer, Sara J; Liu, Shan W

2014-09-01

Hospital crowding and emergency department (ED) boarding are large and growing problems. To date, there has been a paucity of information regarding the quality of care received by patients boarding in the ED compared with the care received by patients on an inpatient unit. We compared the rate of delays and adverse events at the event level that occur while boarding in the ED vs while on an inpatient unit. This study was a secondary analysis of data from medical record review and administrative databases at 2 urban academic teaching hospitals from August 1, 2004, through January 31, 2005. We measured delayed repeat cardiac enzymes, delayed partial thromboplastin time level checks, delayed antibiotic administration, delayed administration of home medications, and adverse events. We compared the incidence of events during ED boarding vs while on an inpatient unit. Among 1431 patient medical records, we identified 1016 events. Emergency department boarding was associated with an increased risk of home medication delays (risk ratio [RR], 1.54; 95% confidence interval [CI], 1.26-1.88), delayed antibiotic administration (RR, 2.49; 95% CI, 1.72-3.52), and adverse events (RR, 2.36; 95% CI, 1.15-4.72). On the contrary, ED boarding was associated with fewer delays in repeat cardiac enzymes (RR, 0.17; 95% CI, 0.09-0.27) and delayed partial thromboplastin time checks (RR, 0.54; 95% CI, 0.27-0.96). Compared with inpatient units, ED boarding was associated with more medication-related delays and adverse events but fewer laboratory-related delays. Until we can eliminate ED boarding, it is critical to identify areas for improvement. Copyright © 2014 Elsevier Inc. All rights reserved.

The reasons for delay lumbar puncture

Directory of Open Access Journals (Sweden)

MH. Lotfi

2017-04-01

Full Text Available Early diagnosis of meningitis and encephalitis and prompt initiation of appropriate therapy is vital and any delay will lead to high mortality and serious and permanent morbidity. The main purpose of this study was to evaluate the management of 220 patients with suspected central nervous system (CNS infections (meningitis and encephalitis to determine the percentage of patients’ suspected CNS infection undergo lumbar puncture in acceptable time (in accordance with conventional algorithms. In this descriptive study, patients with suspected CNS infections admitted to Bu-Ali and Qods hospitals, in the period July 2013 to December 2015 were studied. Information of 220 patients was collected. Continuous variables were summarized as means ± standard deviation and categorical variables as frequencies and percentages. Lumbar puncture (LP in patients was delayed in 200 cases (91%. Most common causes of delay in performing LP were prolongation of the process of determining patient needs to puncture, satisfying patients, CT scan delay and the delay in allowing LP by neurologist. In this study, delaying LP rate was higher than other studies. It seems certain pattern in assistants’ visits for counseling. CT requests and neurologic consultation before LP performed for all adult patients.

Causal inference in nonlinear systems: Granger causality versus time-delayed mutual information

Science.gov (United States)

Li, Songting; Xiao, Yanyang; Zhou, Douglas; Cai, David

2018-05-01

The Granger causality (GC) analysis has been extensively applied to infer causal interactions in dynamical systems arising from economy and finance, physics, bioinformatics, neuroscience, social science, and many other fields. In the presence of potential nonlinearity in these systems, the validity of the GC analysis in general is questionable. To illustrate this, here we first construct minimal nonlinear systems and show that the GC analysis fails to infer causal relations in these systems—it gives rise to all types of incorrect causal directions. In contrast, we show that the time-delayed mutual information (TDMI) analysis is able to successfully identify the direction of interactions underlying these nonlinear systems. We then apply both methods to neuroscience data collected from experiments and demonstrate that the TDMI analysis but not the GC analysis can identify the direction of interactions among neuronal signals. Our work exemplifies inference hazards in the GC analysis in nonlinear systems and suggests that the TDMI analysis can be an appropriate tool in such a case.

Time delayed Ensemble Nudging Method

Science.gov (United States)

An, Zhe; Abarbanel, Henry

Optimal nudging method based on time delayed embedding theory has shows potentials on analyzing and data assimilation in previous literatures. To extend the application and promote the practical implementation, new nudging assimilation method based on the time delayed embedding space is presented and the connection with other standard assimilation methods are studied. Results shows the incorporating information from the time series of data can reduce the sufficient observation needed to preserve the quality of numerical prediction, making it a potential alternative in the field of data assimilation of large geophysical models.

Coronary grafts flow and cardiac pacing modalities: how to improve perioperative myocardial perfusion.

LENUS (Irish Health Repository)

D'Ancona, Giuseppe

2012-02-03

OBJECTIVE: Aim of this study was to investigate modifications of coronary grafts flow during different pacing modalities after CABG. MATERIALS AND METHODS: Two separate prospective studies were conducted in patients undergoing CABG and requiring intraoperative epicardial pacing. In a first study (22 patients) coronary grafts flows were measured during dual chamber pacing (DDD) and during ventricular pacing (VVI). In a second study (10 patients) flows were measured during DDD pacing at different atrio-ventricular (A-V) delay periods. A-V delay was adjusted in 25 ms increments from 25 to 250 ms and flow measurements were performed for each A-V delay increment. A transit time flowmeter was used for the measurements. RESULTS: An average of 3.4 grafts\\/patient were performed. In the first study, average coronary graft flow was 47.4+\\/-20.8 ml\\/min during DDD pacing and 41.8+\\/-18.2 ml\\/min during VVI pacing (P = 0.0004). Furthermore average systolic pressure was 94.3+\\/-10.1 mmHg during DDD pacing and 89.6+\\/-12.2 mmHg during VVV pacing (P = 0.0007). No significant differences in diastolic pressure were recorded during the two different pacing modalities. In the second study, maximal flows were achieved during DDD pacing with an A-V delay of 175 ms (54+\\/-9.6 ml\\/min) and minimal flows were detected at 25 ms A-V delay (38.1+\\/-4.7 ml\\/min) (P=ns). No significant differences in systolic or diastolic blood pressure were noticed during the different A-V delays. CONCLUSION: Grafts flowmetry provides an extra tool to direct supportive measures such as cardiac pacing after CABG. DDD mode with A-V delay around 175 ms. should be preferred to allow for maximal myocardial perfusion via the grafts.

Three-dimensional Improved Delayed Detached Eddy Simulation of a two-bladed vertical axis wind turbine

International Nuclear Information System (INIS)

Lei, Hang; Zhou, Dai; Bao, Yan; Li, Ye; Han, Zhaolong

2017-01-01

Highlights: • The Improved Delayed Detached Eddy Simulation and polyhedral mesh are utilized. • Power coefficient and wake velocity are compared between experiments and simulations. • Improved Delayed Detached Eddy Simulation shows more vortices under dynamic stall. • Different scales of flow separations are distinguished by these two models. - Abstract: The aerodynamic performance of a two-bladed vertical axis wind turbine is investigated using the turbulence model of the Improved Delayed Detached Eddy Simulation and the polyhedral mesh. The sliding mesh technique is used to simulate the rotation of the rotor. Meanwhile, the results obtained by the shear stress transport k-ω model are presented as contrast. Then, the simulated power coefficients at different tip speed ratios and the wake velocity are validated by comparison with the experimental data from available literature. It is shown that the power coefficients and wake velocity predicted by the Improved Delayed Detached Eddy Simulation are closer to the experimental data than those by the shear stress transport k-ω model. The pressure distributions predicted by the two turbulence models show different degrees of discrepancies in different scales of flow separation. By comparing the vorticity magnitude graphs, the Improved Delayed Detached Eddy Simulation is found to be able to capture more exquisite vortices after the flow separations. Limited by its inherent ability, the shear stress transport k-ω model predicts vortices that are less realistic than those of Improved Delayed Detached Eddy Simulation. Hence, it may cause some errors in predicting the pressure distributions, especially when the blades suffer dynamic stall. It is demonstrated that the Improved Delayed Detached Eddy Simulation is regarded as a reliable model to analyze the aerodynamic performance of vertical axis wine turbines.

Correction of misleading information in prescription drug television advertising: The roles of advertisement similarity and time delay.

Science.gov (United States)

Aikin, Kathryn J; Southwell, Brian G; Paquin, Ryan S; Rupert, Douglas J; O'Donoghue, Amie C; Betts, Kevin R; Lee, Philip K

Prescription drug television advertisements containing potentially consequential misinformation sometimes appear in the United States. When that happens, the U.S. Food and Drug Administration can request that companies distribute corrective advertisements to address misinformation and inaccurate claims. Previous research has demonstrated effectiveness in corrective advertising for various products. The present article builds on that work with a randomized experimental study (n = 6454) of corrective advertising investigating the extent to which visual similarity matters between violative and corrective ads and the extent to which time delay matters between violative and corrective advertisement exposure. Our study sample included overweight or obese U.S. adults recruited from an existing online consumer panel representative of the U.S. adult population. We created a brand for a fictitious prescription weight-loss drug and produced corresponding direct-to-consumer (DTC) television ads. All participants viewed the same violative ad, but were randomly assigned to view corrective ads with different levels of visual similarity and exposure time delay using a 4 × 4 between-subjects factorial design. Results suggest corrective ad exposure can influence consumer perceptions of drug efficacy, risks, and benefits previously established by violative ads that overstated drug efficacy, broadened drug indication, and omitted important risk information. Corrective ads also can weaken consumer intentions to consider and investigate a drug. However, ad similarity does not appear to affect consumer perceptions and preferences. Although we found that the effects of violative ad exposure tend to diminish over time, the length of the delay between violative and corrective ad exposure has limited influence. An exception to this was observed with regard to recall of drug benefits and risks, where the impact of corrective ad exposure increases with greater time delay. These results

Social adaptation in multi-agent model of linguistic categorization is affected by network information flow.

Science.gov (United States)

Zubek, Julian; Denkiewicz, Michał; Barański, Juliusz; Wróblewski, Przemysław; Rączaszek-Leonardi, Joanna; Plewczynski, Dariusz

2017-01-01

This paper explores how information flow properties of a network affect the formation of categories shared between individuals, who are communicating through that network. Our work is based on the established multi-agent model of the emergence of linguistic categories grounded in external environment. We study how network information propagation efficiency and the direction of information flow affect categorization by performing simulations with idealized network topologies optimizing certain network centrality measures. We measure dynamic social adaptation when either network topology or environment is subject to change during the experiment, and the system has to adapt to new conditions. We find that both decentralized network topology efficient in information propagation and the presence of central authority (information flow from the center to peripheries) are beneficial for the formation of global agreement between agents. Systems with central authority cope well with network topology change, but are less robust in the case of environment change. These findings help to understand which network properties affect processes of social adaptation. They are important to inform the debate on the advantages and disadvantages of centralized systems.

Dissolvable fluidic time delays for programming multi-step assays in instrument-free paper diagnostics.

Science.gov (United States)

Lutz, Barry; Liang, Tinny; Fu, Elain; Ramachandran, Sujatha; Kauffman, Peter; Yager, Paul

2013-07-21

Lateral flow tests (LFTs) are an ingenious format for rapid and easy-to-use diagnostics, but they are fundamentally limited to assay chemistries that can be reduced to a single chemical step. In contrast, most laboratory diagnostic assays rely on multiple timed steps carried out by a human or a machine. Here, we use dissolvable sugar applied to paper to create programmable flow delays and present a paper network topology that uses these time delays to program automated multi-step fluidic protocols. Solutions of sucrose at different concentrations (10-70% of saturation) were added to paper strips and dried to create fluidic time delays spanning minutes to nearly an hour. A simple folding card format employing sugar delays was shown to automate a four-step fluidic process initiated by a single user activation step (folding the card); this device was used to perform a signal-amplified sandwich immunoassay for a diagnostic biomarker for malaria. The cards are capable of automating multi-step assay protocols normally used in laboratories, but in a rapid, low-cost, and easy-to-use format.

Investigation of relationship between mental workload and information flow rate of accident diagnosis tasks in NPPs

International Nuclear Information System (INIS)

Ha, Chang Hoon

2005-02-01

The objective of this study is to investigate experimentally the relationship between an operator's mental workload and the information flow rate of accident diagnosis tasks and further to propose the information flow rate as an analytic method for measuring the mental workload. There are two types of mental workload in the advanced MCR of NPPs: the information processing workload, which is the processing that the human operator must actually perform in order to complete the diagnosis task, and emotional stress workload experienced by the operator. In this study, the focus is on the former. Three kinds of methods are used to measure the operator's workload: information flow rate, subjective methods, and physiological measures. Information flows for eight accident diagnosis tasks are modeled qualitatively using a stage model and are quantified using Conant's model. The eight accident cases are considered here are: Loss Of Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Steam Line Break (SLB), Feedwater Line Break (FLB), Pressurizer (PZR) spray and heater failure, Reactor Coolant Pump (RCP) trip, Main Steam Isolation Valve (MSIV) failure, and PZR spray failure. The information flow rate is obtained for each diagnosis task by imposing time limit restrictions for the tasks. Subjective methods require the operators to respond to questionnaires to rate their level of mental effort. NASA-TLX and MCH scale are selected as subjective methods. NASA-TLX is a subjective method used in the various fields including the aviation, automobile, and nuclear industries. It has a multi-dimensional rating technique and provides an overall workload score based on a weighted average on six subscales using pair-wise comparison tests. MCH, on the other hand, is one-dimensional and uses a 10- point rating technique. As with NASA-TLX, the higher the score is, the higher the subjective workload is. For the physiological measurements, an eye tracking system analyzes eye movements

Improved visualization of delayed perfusion in lung MRI

International Nuclear Information System (INIS)

Risse, Frank; Eichinger, Monika; Kauczor, Hans-Ulrich; Semmler, Wolfhard; Puderbach, Michael

2011-01-01

Introduction: The investigation of pulmonary perfusion by three-dimensional (3D) dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was proposed recently. Subtraction images are generated for clinical evaluation, but temporal information is lost and perfusion defects might therefore be masked in this process. The aim of this study is to demonstrate a simple analysis strategy and classification for 3D-DCE-MRI perfusion datasets in the lung without omitting the temporal information. Materials and methods: Pulmonary perfusion measurements were performed in patients with different lung diseases using a 1.5 T MR-scanner with a time-resolved 3D-GRE pulse sequence. 25 3D-volumes were acquired after iv-injection of 0.1 mmol/kg KG Gadolinium-DTPA. Three parameters were determined for each pixel: (1) peak enhancement S n,max normalized to the arterial input function to detect regions of reduced perfusion; (2) time between arterial peak enhancement in the large pulmonary artery and tissue peak enhancement τ to visualize regions with delayed bolus onset; and (3) ratio R = S n,max /τ was calculated to visualize impaired perfusion, irrespectively of whether related to reduced or delayed perfusion. Results: A manual selection of peak perfusion images is not required. Five different types of perfusion can be found: (1) normal perfusion; (2) delayed non-reduced perfusion; (3) reduced non-delayed perfusion; (4) reduced and delayed perfusion; and (5) no perfusion. Types II and IV could not be seen in subtraction images since the temporal information is necessary for this purpose. Conclusions: The analysis strategy in this study allows for a simple and observer-independent visualization and classification of impaired perfusion in dynamic contrast-enhanced pulmonary perfusion MRI by using the temporal information of the datasets.

Optimal Re-Routes and Ground Delays Using a Route-Based Aggregate Air Traffic Flow Model

Science.gov (United States)

Soler, Lluis

The National Airspace System (NAS) is very complex and with a high level of uncertainty. For this reason, developing an automated conflict resolution tool at NAS level is presented as a big challenge. One way to address the problem is by using aggregate models, which can significantly reduce its dimension and complexity. Significant effort has been made to develop an air traffic aggregate model capable to effectively state and solve the problem. In this study, a Route-Based Aggregate Model is developed and tested. It consists in a modification of several existing models and overcomes some issues identified in previous aggregate models. It allows the implementation of Traffic Flow Management conventional controls, such as ground delay and rerouting. These control strategies can be used to avoid congestion conflicts based on sectors and airports capacity as well as regions affected by convective weather. The optimization problem is posed as a Linear Programming routine, which guarantees an optimal solution that minimizes the total accumulated delay required to avoid such capacity conflicts. The solutions can be directly translated into specific instructions at aircraft level, via modification of the times of departure and flight plans. The model is integrated with Future Air Traffic Management Concepts Evaluation Tool (FACET), a state of the art air traffic simulation tool, and uses its files as both input and output. This allows simulating in FACET the solution obtained from the aggregate domain. The approach is validated by applying it in three realistic scenarios at different scales. Results show that, for time horizons larger than 2 hours, the accuracy of the aggregate model is similar to other simulation tools. Also, the modified flight plans, the product of the disaggregated solution, reduce the number of capacity conflicts in the FACET simulation. Future research will study the robustness of these solutions and determine the most appropriate scenarios where to

Fractal analysis of intraflow unidirectional\\ud delay over W-LAN and W-WAN environments

OpenAIRE

Pezaros, D.; Sifalakis, M.; Mathy, L.

2007-01-01

We have analysed unidirectional delay traces of a diverse\\ud set of IPv6 microflows routed over W-LAN and W-WAN\\ud environments. Using a number of time-domain and frequency-domain estimators we have examined the existence and intensity of long-range dependence in packet delay when viewed as time-series data. The correlation structures of packet delay on bulk TCP data path and UDP flows follow asymptotic decay while Hurst exponent estimates suggest from moderate to strong intensity(H->1).

Cerebrospinal fluid pulsation amplitude and its quantitative relationship to cerebral blood flow pulsations: a phase-contrast MR flow imaging study

International Nuclear Information System (INIS)

Bhadelia, R.A.; Bogdan, A.R.; Kaplan, R.F.; Wolpert, S.M.

1997-01-01

Our purpose in this investigation was to explain the heterogeneity in the cerebrospinal fluid (CSF) flow pulsation amplitudes. To this end, we determined the contributions of the cerebral arterial and jugular venous flow pulsations to the amplitude of the CSF pulsation. We examined 21 healthy subjects by cine phase-contrast MRI at the C2-3 disc level to demonstrate the CSF and vascular flows as waveforms. Multiple regression analysis was performed to calculate the contributions of (a) the arterial and venous waveform amplitudes and (b) the delay between the maximum systolic slopes of the arterial and venous waveforms (AV delay), in order to predict the amplitude of the CSF waveform. The contribution of the arterial waveform amplitude was positive (r = 0.61; p 0.003) to the CSF waveform amplitude and that of the venous waveform amplitude was negative (r = -0.50; p = 0.006). Both in combination accounted for 56 % of the variance in predicting the CSF waveform amplitude (p < 0.0006). The contribution of AV delay was not significant. The results show that the variance in the CSF flow pulsation amplitudes can be explained by concurrent evaluation of the CSF and vascular flows. Improvement in the techniques, and controlled experiments, may allow use of CSF flow pulsation amplitudes for clinical applications in the non-invasive assessment of intracranial dynamics by MRI. (orig.). With 3 figs., 2 tabs

Delay line MWPC hazard signals inspector

International Nuclear Information System (INIS)

Turner, D.B.; Kirsten, F.; Guiragossian, Z.G.T.; Schilling, R.

1976-01-01

The Hazard Inspector is a CAMAC module which divides a MWPC delay line into 8 independent signal monitor and control segments. Independent control effectively reduces delay line occupation time and cuts the number of background and non-trigger particles accepted by the 4XQT charge-time-pulse-width digitizer, a device presented in a separate communication. Only segments containing legitimate information are digitized. Non-trigger related events are gated out at the digitizer, and contaminating hits are noted for computer correction

Modeling the Structure and Effectiveness of Intelligence Organizations: Dynamic Information Flow Simulation

National Research Council Canada - National Science Library

Behrman, Robert; Carley, Kathleen

2003-01-01

This paper describes the Dynamic Information Flow Simulation (DIFS), an abstract model for analyzing the structure and function of intelligence support organizations and the activities of entities within...

Design of delay insensitive circuits using multi-ring structures

DEFF Research Database (Denmark)

Sparsø, Jens; Staunstrup, Jørgen; Dantzer-Sørensen, Michael

1992-01-01

The design and VLSI implementation of a delay insensitive circuit that computes the inner product of two vec·tors is described. The circuit is based on an iterative serial-parallel multiplication algorithm. The design is based on a data flow approach using pipelines and rings that are combined...

Information Flow Analysis for Human-System Interaction in the SG Level Control

International Nuclear Information System (INIS)

Kim, Jong Hyun; Shin, Yeong Cheol

2008-01-01

Interaction between automatic control and operators is one of main issues in the application of automation technology. Inappropriate information from automatic control systems causes unexpected problems in human-automation collaboration. Poor information becomes critical, especially when the operator takes over the control from an automation system. Operators cannot properly handle the situation transferred from the automatic mode because of inadequate situation awareness, if the operator is out-of-the loop and the automatic control system fails. Some cases of unplanned reactor trips during the transition between the manual mode and the automatic mode are reported in nuclear power plants (NPPs). Among unplanned reactor trips since 2002, two cases were partially caused by automation-related failures of steam generator (SG) level control. This paper conducts information flow analysis to identify information and control requirement for human-system interaction of SG level control. At first, this paper identifies the level of automation in SG level control systems and then function allocation between system control and human operators. Then information flow analysis for monitoring and transition of automation is performed by adapting job process chart. Information and control requirements will be useful as an input for the human-system interface (HSI) design of SG level control

Development and application of traffic flow information collecting and analysis system based on multi-type video

Science.gov (United States)

Lu, Mujie; Shang, Wenjie; Ji, Xinkai; Hua, Mingzhuang; Cheng, Kuo

2015-12-01

Nowadays, intelligent transportation system (ITS) has already become the new direction of transportation development. Traffic data, as a fundamental part of intelligent transportation system, is having a more and more crucial status. In recent years, video observation technology has been widely used in the field of traffic information collecting. Traffic flow information contained in video data has many advantages which is comprehensive and can be stored for a long time, but there are still many problems, such as low precision and high cost in the process of collecting information. This paper aiming at these problems, proposes a kind of traffic target detection method with broad applicability. Based on three different ways of getting video data, such as aerial photography, fixed camera and handheld camera, we develop a kind of intelligent analysis software which can be used to extract the macroscopic, microscopic traffic flow information in the video, and the information can be used for traffic analysis and transportation planning. For road intersections, the system uses frame difference method to extract traffic information, for freeway sections, the system uses optical flow method to track the vehicles. The system was applied in Nanjing, Jiangsu province, and the application shows that the system for extracting different types of traffic flow information has a high accuracy, it can meet the needs of traffic engineering observations and has a good application prospect.

Information flow between weakly interacting lattices of coupled maps

Energy Technology Data Exchange (ETDEWEB)

Dobyns, York [PEAR, Princeton University, Princeton, NJ 08544-5263 (United States); Atmanspacher, Harald [Institut fuer Grenzgebiete der Psychologie und Psychohygiene, Wilhelmstr. 3a, 79098 Freiburg (Germany)]. E-mail: haa@igpp.de

2006-05-15

Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary.

Information flow between weakly interacting lattices of coupled maps

International Nuclear Information System (INIS)

Dobyns, York; Atmanspacher, Harald

2006-01-01

Weakly interacting lattices of coupled maps can be modeled as ordinary coupled map lattices separated from each other by boundary regions with small coupling parameters. We demonstrate that such weakly interacting lattices can nevertheless have unexpected and striking effects on each other. Under specific conditions, particular stability properties of the lattices are significantly influenced by their weak mutual interaction. This observation is tantamount to an efficacious information flow across the boundary

Data Mining for Understanding and Impriving Decision-Making Affecting Ground Delay Programs

Science.gov (United States)

Kulkarni, Deepak; Wang, Yao Xun; Sridhar, Banavar

2013-01-01

The continuous growth in the demand for air transportation results in an imbalance between airspace capacity and traffic demand. The airspace capacity of a region depends on the ability of the system to maintain safe separation between aircraft in the region. In addition to growing demand, the airspace capacity is severely limited by convective weather. During such conditions, traffic managers at the FAA's Air Traffic Control System Command Center (ATCSCC) and dispatchers at various Airlines' Operations Center (AOC) collaborate to mitigate the demand-capacity imbalance caused by weather. The end result is the implementation of a set of Traffic Flow Management (TFM) initiatives such as ground delay programs, reroute advisories, flow metering, and ground stops. Data Mining is the automated process of analyzing large sets of data and then extracting patterns in the data. Data mining tools are capable of predicting behaviors and future trends, allowing an organization to benefit from past experience in making knowledge-driven decisions. The work reported in this paper is focused on ground delay programs. Data mining algorithms have the potential to develop associations between weather patterns and the corresponding ground delay program responses. If successful, they can be used to improve and standardize TFM decision resulting in better predictability of traffic flows on days with reliable weather forecasts. The approach here seeks to develop a set of data mining and machine learning models and apply them to historical archives of weather observations and forecasts and TFM initiatives to determine the extent to which the theory can predict and explain the observed traffic flow behaviors.

Investigation of relationship between mental workload and information flow rate of accident diagnosis tasks in NPPs

Energy Technology Data Exchange (ETDEWEB)

Ha, Chang Hoon

2005-02-15

The objective of this study is to investigate experimentally the relationship between an operator's mental workload and the information flow rate of accident diagnosis tasks and further to propose the information flow rate as an analytic method for measuring the mental workload. There are two types of mental workload in the advanced MCR of NPPs: the information processing workload, which is the processing that the human operator must actually perform in order to complete the diagnosis task, and emotional stress workload experienced by the operator. In this study, the focus is on the former. Three kinds of methods are used to measure the operator's workload: information flow rate, subjective methods, and physiological measures. Information flows for eight accident diagnosis tasks are modeled qualitatively using a stage model and are quantified using Conant's model. The eight accident cases are considered here are: Loss Of Coolant Accident (LOCA), Steam Generator Tube Rupture (SGTR), Steam Line Break (SLB), Feedwater Line Break (FLB), Pressurizer (PZR) spray and heater failure, Reactor Coolant Pump (RCP) trip, Main Steam Isolation Valve (MSIV) failure, and PZR spray failure. The information flow rate is obtained for each diagnosis task by imposing time limit restrictions for the tasks. Subjective methods require the operators to respond to questionnaires to rate their level of mental effort. NASA-TLX and MCH scale are selected as subjective methods. NASA-TLX is a subjective method used in the various fields including the aviation, automobile, and nuclear industries. It has a multi-dimensional rating technique and provides an overall workload score based on a weighted average on six subscales using pair-wise comparison tests. MCH, on the other hand, is one-dimensional and uses a 10- point rating technique. As with NASA-TLX, the higher the score is, the higher the subjective workload is. For the physiological measurements, an eye tracking system analyzes

Time-delay analyzer with continuous discretization

International Nuclear Information System (INIS)

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

1988-01-01

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

Information flow in layered networks of non-monotonic units

International Nuclear Information System (INIS)

Neves, Fabio Schittler; Schubert, Benno Martim; Erichsen, Rubem Jr

2015-01-01

Layered neural networks are feedforward structures that yield robust parallel and distributed pattern recognition. Even though much attention has been paid to pattern retrieval properties in such systems, many aspects of their dynamics are not yet well characterized or understood. In this work we study, at different temperatures, the memory activity and information flows through layered networks in which the elements are the simplest binary odd non-monotonic function. Our results show that, considering a standard Hebbian learning approach, the network information content has its maximum always at the monotonic limit, even though the maximum memory capacity can be found at non-monotonic values for small enough temperatures. Furthermore, we show that such systems exhibit rich macroscopic dynamics, including not only fixed point solutions of its iterative map, but also cyclic and chaotic attractors that also carry information. (paper)

Information flow in layered networks of non-monotonic units

Science.gov (United States)

Schittler Neves, Fabio; Martim Schubert, Benno; Erichsen, Rubem, Jr.

2015-07-01

Layered neural networks are feedforward structures that yield robust parallel and distributed pattern recognition. Even though much attention has been paid to pattern retrieval properties in such systems, many aspects of their dynamics are not yet well characterized or understood. In this work we study, at different temperatures, the memory activity and information flows through layered networks in which the elements are the simplest binary odd non-monotonic function. Our results show that, considering a standard Hebbian learning approach, the network information content has its maximum always at the monotonic limit, even though the maximum memory capacity can be found at non-monotonic values for small enough temperatures. Furthermore, we show that such systems exhibit rich macroscopic dynamics, including not only fixed point solutions of its iterative map, but also cyclic and chaotic attractors that also carry information.

Informing the Financing of Universal Energy Access: An Assessment of Current Flows

Energy Technology Data Exchange (ETDEWEB)

Bazilian, Morgan; Nussbaumer, Patrick [United Nations Industrial Development Organization, Vienna (Austria); Gualberti, Giorgio [Technical University of Lisbon, Lisbon (Portugal); Haites, Erik [Margaree Consultants Inc., Toronto (Canada); Levi, Michael [Council on Foreign Relations, New York, NY (United States); Siegel, Judy [Energy and Security Group, Reston, VA (United States); Kammen, Daniel [The World Bank, Washington, DC (United States); Fenhann, Joergen [UNEP Risoe Centre, Technical University of Denmark (Denmark)

2011-07-15

Energy poverty is widely recognized as a major obstacle to economic and social development and poverty alleviation. To help inform the design of appropriate and effective policies to reduce energy poverty, we present a brief analysis of the current macro financial flows in the electricity and gas distribution sectors in developing countries. We build on the methodology used to quantify the flows of investment in the climate change area. This methodology relies on national gross fixed capital formation, overseas development assistance, and foreign direct investment. These high-level and aggregated investment figures provide a sense of scale to policy-makers, but are only a small part of the information required to design financial vehicles. In addition, these figures tend to mask numerous variations between sectors and countries, as well as trends and other temporal fluctuations. Nonetheless, for the poorest countries, one can conclude that the current flows are considerably short (at least five times) of what will be required to provide a basic level of access to clean, modern energy services to the 'energy poor'.

The Impact of the Information Logistics Flows on the Processes of Municipal Wastes Management

Directory of Open Access Journals (Sweden)

Samohovych Oleksandr S.

2017-06-01

Full Text Available The article is aimed at identifying the impact of information incompleteness and asymmetry, irrational behavior of actors on the processes of municipal wastes management. It has been found that, at the present moment in Ukraine, quality of the transfer of information flows on the municipal wastes management between the State authority, local government bodies, enterprises, and the public stays at a low level. The urban sanitation schemes are being adopted and waste management technologies are being introduced at the local level, but the local government bodies have not been provided with sufficient information to make optimal decisions. Acting independently, the market mechanism would not be able to overcome the asymmetry of information in the short terms, and the State intervention would be needed to correct the information inadequacy of the municipal waste market. Prospect for future research will be determining conditions for an effective distribution of information flows in the process of municipal wastes management.

Are large-scale flow experiments informing the science and management of freshwater ecosystems?

Science.gov (United States)

Olden, Julian D.; Konrad, Christopher P.; Melis, Theodore S.; Kennard, Mark J.; Freeman, Mary C.; Mims, Meryl C.; Bray, Erin N.; Gido, Keith B.; Hemphill, Nina P.; Lytle, David A.; McMullen, Laura E.; Pyron, Mark; Robinson, Christopher T.; Schmidt, John C.; Williams, John G.

2013-01-01

Greater scientific knowledge, changing societal values, and legislative mandates have emphasized the importance of implementing large-scale flow experiments (FEs) downstream of dams. We provide the first global assessment of FEs to evaluate their success in advancing science and informing management decisions. Systematic review of 113 FEs across 20 countries revealed that clear articulation of experimental objectives, while not universally practiced, was crucial for achieving management outcomes and changing dam-operating policies. Furthermore, changes to dam operations were three times less likely when FEs were conducted primarily for scientific purposes. Despite the recognized importance of riverine flow regimes, four-fifths of FEs involved only discrete flow events. Over three-quarters of FEs documented both abiotic and biotic outcomes, but only one-third examined multiple taxonomic responses, thus limiting how FE results can inform holistic dam management. Future FEs will present new opportunities to advance scientifically credible water policies.

Low Delay Wyner-Ziv Coding Using Optical Flow

DEFF Research Database (Denmark)

Salmistraro, Matteo; Forchhammer, Søren

2014-01-01

on preceding frames for the generation of the SI by means of Optical Flow (OF), which is also used in the refinement step of the SI for enhanced RD performance. Compared with a state-of-the-art extrapolation-based decoder the proposed solution achieves RD Bjontegaard gains up to 1.3 dB....

A neural flow estimator

DEFF Research Database (Denmark)

Jørgensen, Ivan Harald Holger; Bogason, Gudmundur; Bruun, Erik

1995-01-01

This paper proposes a new way to estimate the flow in a micromechanical flow channel. A neural network is used to estimate the delay of random temperature fluctuations induced in a fluid. The design and implementation of a hardware efficient neural flow estimator is described. The system...... is implemented using switched-current technique and is capable of estimating flow in the μl/s range. The neural estimator is built around a multiplierless neural network, containing 96 synaptic weights which are updated using the LMS1-algorithm. An experimental chip has been designed that operates at 5 V...

The source of investment cash flow sensitivity in manufacturing firms: Is it asymmetric information or agency costs?

Directory of Open Access Journals (Sweden)

Daniel Makina

2016-09-01

Full Text Available In the literature, positive investment cash flow sensitivity is attributed to either asymmetric information induced financing constraints or the agency costs of free cash flow. Using data from a sample of 68 manufacturing firms listed on the South African JSE, this paper contributes to the literature by investigating the source of investment cash flow sensitivity. We have found that asymmetric information explains the positive investment cash flow sensitivity better than agency costs. Furthermore, asymmetric information has been observed to be more pronounced in low-dividend-paying firms and small firms. Despite South Africa’s having a developed financial system by international standards, small firms are seen to be financially constrained. We attribute the absence of investment cash flow sensitivity due to agency costs to good corporate governance of South African listed firms. Thus the paper provides further evidence in support of the proposition in the literature that the source of investment cash flow sensitivity may depend on the institutional setting of a country, such as its corporate governance.

Management of delayed nuclear power plant projects

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-09-01

According to the available information at the IAEA PRIS (Power Reactor Information System) at the end of 1998 there were more than 40 nuclear power plant projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules showed large variations due to several issues, including financial, economic and public opinion factors. Taking into account the number of projects with several years delay in their original schedules, it was considered useful to identify the subject areas where exchange of experience among Member States would be mutually beneficial in identification of problems and development of guidance for successful management of the completion of these delayed projects. A joint programme of the IAEA Departments of Nuclear Energy (Nuclear Power Engineering Section) and Technical Co-operation (Europe Section, with additional support from the Latin America and West Asia Sections) was set up during the period 1997-1998. The specific aim of the programme was to provide assistance in the management of delayed nuclear power plants regarding measures to maintain readiness for resuming the project implementation schedule when the conditions permit. The integration of IAEA interdepartmental resources enabled the participation of 53 experts from 14 Member States resulting in a wider exchange of experience and dissemination of guidance. Under the framework of the joint programme, senior managers directly responsible for delayed nuclear power plant projects identified several issues or problem areas that needed to be addressed and guidance on management be provided. A work plan for the development of several working documents, addressing the different issues, was established. Subsequently these documents were merged into a single one to produce the present publication. This publication provides information and practical examples on necessary management actions to preserve

Management of delayed nuclear power plant projects

International Nuclear Information System (INIS)

1999-09-01

According to the available information at the IAEA PRIS (Power Reactor Information System) at the end of 1998 there were more than 40 nuclear power plant projects with delays of five or more years with respect to the originally scheduled commercial operation. The degree of conformance with original construction schedules showed large variations due to several issues, including financial, economic and public opinion factors. Taking into account the number of projects with several years delay in their original schedules, it was considered useful to identify the subject areas where exchange of experience among Member States would be mutually beneficial in identification of problems and development of guidance for successful management of the completion of these delayed projects. A joint programme of the IAEA Departments of Nuclear Energy (Nuclear Power Engineering Section) and Technical Co-operation (Europe Section, with additional support from the Latin America and West Asia Sections) was set up during the period 1997-1998. The specific aim of the programme was to provide assistance in the management of delayed nuclear power plants regarding measures to maintain readiness for resuming the project implementation schedule when the conditions permit. The integration of IAEA interdepartmental resources enabled the participation of 53 experts from 14 Member States resulting in a wider exchange of experience and dissemination of guidance. Under the framework of the joint programme, senior managers directly responsible for delayed nuclear power plant projects identified several issues or problem areas that needed to be addressed and guidance on management be provided. A work plan for the development of several working documents, addressing the different issues, was established. Subsequently these documents were merged into a single one to produce the present publication. This publication provides information and practical examples on necessary management actions to preserve

Delayed interval delivery in twin pregnancy without cerclage: Case ...

African Journals Online (AJOL)

After the loss of the first foetus, delayed delivery in multiple pregnancies can be successful in selected cases as exemplified by the case presentation. In well prepared perinatal centers, with physically and psychologically balanced patients who are well informed about the risks and benefits of the procedure, delayed interval ...

Ground Tilt Time Delays between Kilauea Volcano's Summit and East Rift Zone Caused by Magma Reservoir Buffering

Science.gov (United States)

Haney, M. M.; Patrick, M. R.; Anderson, K. R.

2016-12-01

A cyclic pattern of ground deformation, called a deflation-inflation (DI) cycle, is commonly observed at Kilauea Volcano, Hawai`i. These cycles are an important part of Kilauea's eruptive activity because they directly influence the level of the summit lava lake as well as the effusion rate (and resulting lava flow hazard) at the East Rift Zone eruption site at Pu`u `O`o. DI events normally span several days, and are measured both at the summit and at Pu`u `O`o cone (20 km distance). Signals appear first at the summit and are then observed at Pu`u `O`o after an apparent delay of between 0.5 and 10 hours, which has been previously interpreted as reflecting magma transport time. We propose an alternate explanation, in which the apparent delay is an artifact of buffering by the small magma reservoir thought to exist at Pu`u `O`o. Simple Poiseuille flow modeling demonstrates that this apparent delay can be reproduced by the changing balance of inflow (from the summit) and outflow (to surface lava flows) at the Pu`u `O`o magma reservoir. The apparent delay is sensitive to the geometry of the conduit leaving Pu`u `O`o, feeding surface lava flows. We demonstrate how the reservoir buffering is quantitatively equivalent to a causal low-pass filter, which explains both the apparent delay as well as the smoothed, skewed nature of the signal at Pu`u `O`o relative to the summit. By comparing summit and Pu`u `O`o ground tilt signals over an extended time period, it may be possible to constrain the changing geometry of the shallow magmatic system through time.

Turn-Taking Based on Information Flow for Fluent Human-Robot Interaction

OpenAIRE

Thomaz, Andrea L.; Chao, Crystal

2011-01-01

Turn-taking is a fundamental part of human communication. Our goal is to devise a turn-taking framework for human-robot interaction that, like the human skill, represents something fundamental about interaction, generic to context or domain. We propose a model of turn-taking, and conduct an experiment with human subjects to inform this model. Our findings from this study suggest that information flow is an integral part of human floor-passing behavior. Following this, we implement autonomous ...

Effects of time delay on stochastic resonance of the stock prices in financial system

Energy Technology Data Exchange (ETDEWEB)

Li, Jiang-Cheng [Department of Physics, Yunnan University, Kunming, 650091 (China); Li, Chun [Department of Computer Science, Puer Teachers' College, Puer 665000 (China); Mei, Dong-Cheng, E-mail: meidch@ynu.edu.cn [Department of Physics, Yunnan University, Kunming, 650091 (China)

2014-06-13

The effect of time delay on stochastic resonance of the stock prices in finance system was investigated. The time delay is introduced into the Heston model driven by the extrinsic and intrinsic periodic information for stock price. The signal power amplification (SPA) was calculated by numerical simulation. The results indicate that an optimal critical value of delay time maximally enhances the reverse-resonance in the behaviors of SPA as a function of long-run variance of volatility or cross correlation coefficient between noises for both cases of intrinsic and extrinsic periodic information. Moreover, in both cases, being a critical value in the delay time, when the delay time takes value below the critical value, reverse-resonance increases with the delay time increasing, however, when the delay time takes value above the critical value, the reverse-resonance decrease with the delay time increasing. - Highlights: • The effects of delay time on stochastic resonance of the stock prices was investigated. • There is an optimal critical value of delay time maximally enhances the reverse-resonance • The reverse-resonance increases with the delay time increasing as the delay time takes value below the critical value • The reverse-resonance decrease with the delay time increasing as the delay time takes value above the critical value.

Effects of time delay on stochastic resonance of the stock prices in financial system

International Nuclear Information System (INIS)

Li, Jiang-Cheng; Li, Chun; Mei, Dong-Cheng

2014-01-01

The effect of time delay on stochastic resonance of the stock prices in finance system was investigated. The time delay is introduced into the Heston model driven by the extrinsic and intrinsic periodic information for stock price. The signal power amplification (SPA) was calculated by numerical simulation. The results indicate that an optimal critical value of delay time maximally enhances the reverse-resonance in the behaviors of SPA as a function of long-run variance of volatility or cross correlation coefficient between noises for both cases of intrinsic and extrinsic periodic information. Moreover, in both cases, being a critical value in the delay time, when the delay time takes value below the critical value, reverse-resonance increases with the delay time increasing, however, when the delay time takes value above the critical value, the reverse-resonance decrease with the delay time increasing. - Highlights: • The effects of delay time on stochastic resonance of the stock prices was investigated. • There is an optimal critical value of delay time maximally enhances the reverse-resonance • The reverse-resonance increases with the delay time increasing as the delay time takes value below the critical value • The reverse-resonance decrease with the delay time increasing as the delay time takes value above the critical value

Flow-Tagging Velocimetry for Hypersonic Flows Using Fluorescence of Nitric Oxide

Science.gov (United States)

Danehy, P. M.; OByrne, S.; Houwing, A. F. P.

2001-01-01

We investigate a new type of flow-tagging velocimetry technique for hypersonic flows. The technique involves exciting a thin line of nitric oxide molecules with a laser beam and then, after some delay, acquiring an image of the displaced line. One component of velocity is determined from the time of flight. This method is applied to measure the velocity profile in a Mach 8.5 laminar, hypersonic boundary layer in the Australian National Universities T2 free-piston shock tunnel. The velocity is measured with an uncertainty of approximately 2%. Comparison with a CFD simulation of the flow shows reasonable agreement.

Statistical delay estimation in digital circuits using VHDL

Directory of Open Access Journals (Sweden)

Milić Miljana Lj.

2014-01-01

Full Text Available The most important feature of modern integrated circuit is the speed. It depends on circuit's delay. For the design of high-speed digital circuits, it is necessary to evaluate delays in the earliest stages of design, thus making it easy to modify and redesign a circuit if it's too slow. This paper gives an approach for efficient delay estimation in the describing phase of the circuit design. The method can statistically estimate the minimum and maximum delay of all possible paths and signal transitions in the circuit, considering the practical implementation of circuits, and information about the parameters' tolerances. The method uses a VHDL description and is verified on ISCAS85 benchmark circuits. Matlab was used for data processing.

Optimal Joint Expected Delay Forwarding in Delay Tolerant Networks

OpenAIRE

Jia Xu; Xin Feng; Wen Jun Yang; Ru Chuan Wang; Bing Qing Han

2013-01-01

Multicopy forwarding schemes have been employed in delay tolerant network (DTN) to improve the delivery delay and delivery rate. Much effort has been focused on reducing the routing cost while retaining high performance. This paper aims to provide an optimal joint expected delay forwarding (OJEDF) protocol which minimizes the expected delay while satisfying a certain constant on the number of forwardings per message. We propose a comprehensive forwarding metric called joint expected delay (JE...

Dynamic logics of networks: Information flow and the spread of opinion

NARCIS (Netherlands)

Christoff, Z.L.

2016-01-01

This thesis uses logical tools to investigate a number of basic features of social networks and their evolution over time, including flow of information and spread of opinions. Part I contains the preliminaries, including an introduction to the basic phenomena in social networks that call for a

A family of spatial interaction models incorporating information flows and choice set constraints applied to U.S. interstate labor flows.

Science.gov (United States)

Smith, T R; Slater, P B

1981-01-01

"A new family of migration models belonging to the elimination by aspects family is examined, with the spatial interaction model shown to be a special case. The models have simple forms; they incorporate information flow processes and choice set constraints; they are free of problems raised by the Luce Choice Axiom; and are capable of generating intransitive flows. Preliminary calibrations using the Continuous Work History Sample [time] series data indicate that the model fits the migration data well, while providing estimates of interstate job message flows. The preliminary calculations also indicate that care is needed in assuming that destination [attraction] are independent of origins." excerpt

Cell cycle delays induced by heavy ion irradiation of synchronous mammalian cells

International Nuclear Information System (INIS)

Scholz, M.; Kraft-Weyrather, W.; Ritter, S.; Kraft, G.

1994-01-01

Cell cycle delays in V79 Chinese hamster cells induced by heavy ion exposure have been investigated using flow cytometry. Synchronous cell populations in G 1 -, S- and late-S/G 2 M-phase were used. Cells were irradiated with particles from Z = 10 (neon) up to Z = 96 (uranium) in the energy range from 2.4 to 17.4 MeV/u and the LET range from 415 to 16225 keV/μm at the UNILAC at GSI, Darmstadt. For comparison, experiments with 250 kV X-rays were performed. For light particles like neon, cell cycle perturbations comparable to those after X-ray irradiation were found, and with increasing LET an increasing delay per particle traversal was observed. For the highest LET-values, extended delays in G 1 -, S- and G 2 M-phase were detected immediately after irradiation. A large fraction of the cells remained in S-phase or G 2 M-phase up to 48 h or longer after irradiation. No significant cell age dependence of cycle delays was detected for the very high LET values. In addition to cell cycle delays, two effects related to the DNA-content as determined by flow cytometry were found after irradiation with very high LET particles, which were attributed to cell fusion and to drastic morphological changes of the cells. Estimations based on the dose deposited by a single particle hit in the cell nucleus and the actual number of hits show, that the basic trend of the experimental results can be explained by the stochastic properties of particle radiation. (orig.)

Experimental Study of Flow Through Carotid Aneurysms

Science.gov (United States)

Masoomi, Faezeh; Mejia-Alvarez, Ricardo

2017-11-01

There is evidence that traditional endovascular techniques like coiling are not effective for treatment of wide-neck cerebral aneurysms. Flow Diverter Stents (FDS) have emerged as promising devices for treating complex aneurysms since they enable treatment of aneurysms that were considered untreatable before. Recent studies suggest a number of associated risks with FDS, including in-stent thrombosis, perianeurysmal edema, delayed hemorrhage, and perforator occlusions. Chong et al. simulated hemodynamic behavior using patient-specific data. From their study, it is possible to infer that the standard deviation of energy loss could be a good predictor for intervention success. The aim of this study is to investigate the flow in models of cerebral aneurysms before and after FDS insertion using PIV. These models will be based on actual clinical studies and will be fabricated with advanced additive manufacturing techniques. These data will then be used to explore flow parameters that could inform the likelihood of post-intervention aneurysm rupture, and help determine FDS designs that better suit any particular patient before its procedure.

Informed Decision Making Process for Managing Environmental Flows in Small River Basins

Science.gov (United States)

Padikkal, S.; Rema, K. P.

2013-03-01

Numerous examples exist worldwide of partial or complete alteration to the natural flow regime of river systems as a consequence of large scale water abstraction from upstream reaches. The effects may not be conspicuous in the case of very large rivers, but the ecosystems of smaller rivers or streams may be completely destroyed over a period of time. While restoration of the natural flow regime may not be possible, at present there is increased effort to implement restoration by regulating environmental flow. This study investigates the development of an environmental flow management model at an icon site in the small river basin of Bharathapuzha, west India. To determine optimal environmental flow regimes, a historic flow model based on data assimilated since 1978 indicated a satisfactory minimum flow depth for river ecosystem sustenance is 0.907 m (28.8 m3/s), a value also obtained from the hydraulic model; however, as three of the reservoirs were already operational at this time a flow depth of 0.922 m is considered a more viable estimate. Analysis of daily stream flow in 1997-2006, indicated adequate flow regimes during the monsoons in June-November, but that sections of the river dried out in December-May with alarming water quality conditions near the river mouth. Furthermore, the preferred minimum `dream' flow regime expressed by stakeholders of the region is a water depth of 1.548 m, which exceeds 50 % of the flood discharge in July. Water could potentially be conserved for environmental flow purposes by (1) the de-siltation of existing reservoirs or (2) reducing water spillage in the transfer between river basins. Ultimately environmental flow management of the region requires the establishment of a co-ordinated management body and the regular assimilation of water flow information from which science based decisions are made, to ensure both economic and environmental concerns are adequately addressed.

Learning monopolies with delayed feedback on price expectations

Science.gov (United States)

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.

A constructive logic for services and information flow in computer networks

NARCIS (Netherlands)

Borghuis, V.A.J.; Feijs, L.M.G.

2000-01-01

In this paper we introduce a typed -calculus in which computer networks can be formalized and directed at situations where the services available on the network are stationary, while the information can flow freely. For this calculus, an analogue of the ‘propositions-as-types ’interpretation of

Correction for Delay and Dispersion Results in More Accurate Cerebral Blood Flow Ischemic Core Measurement in Acute Stroke.

Science.gov (United States)

Lin, Longting; Bivard, Andrew; Kleinig, Timothy; Spratt, Neil J; Levi, Christopher R; Yang, Qing; Parsons, Mark W

2018-04-01

This study aimed to assess how the ischemic core measured by perfusion computed tomography (CTP) was affected by the delay and dispersion effect. Ischemic stroke patients having CTP performed within 6 hours of onset were included. The CTP data were processed twice, generating standard cerebral blood flow (sCBF) and delay- and dispersion-corrected CBF (ddCBF), respectively. Ischemic core measured by the sCBF and ddCBF was then compared at the relative threshold core were used: acute diffusion-weighted imaging or 24-hour diffusion-weighted imaging in patients with complete recanalization. Difference of core volume between CTP and diffusion-weighted imaging was estimated by Mann-Whitney U test and limits of agreement. Patients were also classified into favorable and unfavorable CTP patterns. The imaging pattern classification by sCBF and ddCBF was compared by the χ 2 test; their respective ability to predict good clinical outcome (3-month modified Rankin Scale score) was tested in logistic regression. Fifty-five patients were included in this study. Median sCBF ischemic core volume was 38.5 mL (12.4-61.9 mL), much larger than the median core volume of 17.2 mL measured by ddCBF (interquartile range, 5.5-38.8; P core much closer to diffusion-weighted imaging core references, with the mean volume difference of -0.1 mL (95% limits of agreement, -25.4 to 25.2; P =0.97) and 16.7 mL (95% limits of agreement, -21.7 to 55.2; P core measurement on CTP. © 2018 American Heart Association, Inc.

Electrical Activity in a Time-Delay Four-Variable Neuron Model under Electromagnetic Induction

Directory of Open Access Journals (Sweden)

Keming Tang

2017-11-01

Full Text Available To investigate the effect of electromagnetic induction on the electrical activity of neuron, the variable for magnetic flow is used to improve Hindmarsh–Rose neuron model. Simultaneously, due to the existence of time-delay when signals are propagated between neurons or even in one neuron, it is important to study the role of time-delay in regulating the electrical activity of the neuron. For this end, a four-variable neuron model is proposed to investigate the effects of electromagnetic induction and time-delay. Simulation results suggest that the proposed neuron model can show multiple modes of electrical activity, which is dependent on the time-delay and external forcing current. It means that suitable discharge mode can be obtained by selecting the time-delay or external forcing current, which could be helpful for further investigation of electromagnetic radiation on biological neuronal system.

Stability of formation control using a consensus protocol under directed communications with two time delays and delay scheduling

Science.gov (United States)

Cepeda-Gomez, Rudy; Olgac, Nejat

2016-01-01

We consider a linear algorithm to achieve formation control in a group of agents which are driven by second-order dynamics and affected by two rationally independent delays. One of the delays is in the position and the other in the velocity information channels. These delays are taken as constant and uniform throughout the system. The communication topology is assumed to be directed and fixed. The formation is attained by adding a supplementary control term to the stabilising consensus protocol. In preparation for the formation control logic, we first study the stability of the consensus, using the recent cluster treatment of characteristic roots (CTCR) paradigm. This effort results in a unique depiction of the non-conservative stability boundaries in the domain of the delays. However, CTCR requires the knowledge of the potential stability switching loci exhaustively within this domain. The creation of these loci is done in a new surrogate coordinate system, called the 'spectral delay space (SDS)'. The relative stability is also investigated, which has to do with the speed of reaching consensus. This step leads to a paradoxical control design concept, called the 'delay scheduling', which highlights the fact that the group behaviour may be enhanced by increasing the delays. These steps lead to a control strategy to establish a desired group formation that guarantees spacing among the agents. Example case studies are presented to validate the underlying analytical derivations.

Directedness of information flow in mobile phone communication networks.

Directory of Open Access Journals (Sweden)

Fernando Peruani

Full Text Available Without having direct access to the information that is being exchanged, traces of information flow can be obtained by looking at temporal sequences of user interactions. These sequences can be represented as causality trees whose statistics result from a complex interplay between the topology of the underlying (social network and the time correlations among the communications. Here, we study causality trees in mobile-phone data, which can be represented as a dynamical directed network. This representation of the data reveals the existence of super-spreaders and super-receivers. We show that the tree statistics, respectively the information spreading process, are extremely sensitive to the in-out degree correlation exhibited by the users. We also learn that a given information, e.g., a rumor, would require users to retransmit it for more than 30 hours in order to cover a macroscopic fraction of the system. Our analysis indicates that topological node-node correlations of the underlying social network, while allowing the existence of information loops, they also promote information spreading. Temporal correlations, and therefore causality effects, are only visible as local phenomena and during short time scales. Consequently, the very idea that there is (intentional information spreading beyond a small vecinity is called into question. These results are obtained through a combination of theory and data analysis techniques.

Spatial-Aided Low-Delay Wyner-Ziv Video Coding

Directory of Open Access Journals (Sweden)

Bo Wu

2009-01-01

Full Text Available In distributed video coding, the side information (SI quality plays an important role in Wyner-Ziv (WZ frame coding. Usually, SI is generated at the decoder by the motion-compensated interpolation (MCI from the past and future key frames under the assumption that the motion trajectory between the adjacent frames is translational with constant velocity. However, this assumption is not always true and thus, the coding efficiency for WZ coding is often unsatisfactory in video with high and/or irregular motion. This situation becomes more serious in low-delay applications since only motion-compensated extrapolation (MCE can be applied to yield SI. In this paper, a spatial-aided Wyner-Ziv video coding (WZVC in low-delay application is proposed. In SA-WZVC, at the encoder, each WZ frame is coded as performed in the existing common Wyner-Ziv video coding scheme and meanwhile, the auxiliary information is also coded with the low-complexity DPCM. At the decoder, for the WZ frame decoding, auxiliary information should be decoded firstly and then SI is generated with the help of this auxiliary information by the spatial-aided motion-compensated extrapolation (SA-MCE. Theoretical analysis proved that when a good tradeoff between the auxiliary information coding and WZ frame coding is achieved, SA-WZVC is able to achieve better rate distortion performance than the conventional MCE-based WZVC without auxiliary information. Experimental results also demonstrate that SA-WZVC can efficiently improve the coding performance of WZVC in low-delay application.

Effective information flow through efficient supply chain management - Value stream mapping approach Case Outokumpu Tornio Works

OpenAIRE

Juvonen, Piia

2012-01-01

ABSTRACT Juvonen, Piia Suvi Päivikki 2012. Effective information flow through efficient supply chain management -Value stream mapping approach - Case Outokumpu Tornio Works. Master`s Thesis. Kemi-Tornio University of Applied Sciences. Business and Culture. Pages 63. Appendices 2. The general aim of this thesis is to explore effective information flow through efficient supply chain management by following one of the lean management principles, value stream mapping. The specific research...

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

Science.gov (United States)

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.

Investigation of relation between operator's mental workload and information flow in accident diagnosis tasks of nuclear power plant

Energy Technology Data Exchange (ETDEWEB)

Ha, Chang Hoon; Kim, Jong Hyun; Seong, Poong Hyun [KAIST, Taejon (Korea, Republic of)

2004-07-01

In the main control room (MCR) of a nuclear power plant (NPP), there are lots of dynamic information sources for MCR operator's situation awareness. As the human-machine interface in MCR is advanced, operator's information acquisition, information gathering and decision-making is becoming an important part to maintain the effective and safe operation of NPPs. Diagnostic task in complex and huge systems like NPP is the most difficult and mental effort-demanding for operators. This research investigates the relation between operator's mental workload and information flow in accident diagnosis tasks. The amount of information flow is quantified, using information flow model and Conant's model, a kind of information theory. For the mental workload measure, eye blink rate, blink duration, fixation time, number of fixation, and gaze direction are measured during accident diagnosis tasks. Subjective methods such as NASA-Task Load Index (NASA-TLX) and Modified Cooper-Harper (MCH) method are also used in the experiment. It is shown that the operator's mental workload has significant relation to information flow of diagnosis task. It makes possible to predict the mental workload through the quantity of the information flow of a system.

Identification of optimal inspection interval via delay-time concept

Directory of Open Access Journals (Sweden)

Glauco Ricardo Simões Gomes

2016-06-01

Full Text Available This paper presents an application of mathematical modeling aimed at managing maintenance based on the delay-time concept. The study scenario was the manufacturing sector of an industrial unit, which operates 24 hours a day in a continuous flow of production. The main idea was to use the concepts of this approach to determine the optimal time of preventive action by the maintenance department in order to ensure the greatest availability of equipment and facilities at appropriate maintenance costs. After a brief introduction of the subject, the article presents topics that illustrate the importance of mathematical modeling in maintenance management and the delay-time concept. It also describes the characteristics of the company where the study was conducted, as well as the data related to the production process and maintenance actions. Finally, the results obtained after applying the delay-time concept are presented and discussed, as well as the limitations of the article and the proposals for future research.

Side Information and Noise Learning for Distributed Video Coding using Optical Flow and Clustering

DEFF Research Database (Denmark)

Luong, Huynh Van; Rakêt, Lars Lau; Huang, Xin

2012-01-01

Distributed video coding (DVC) is a coding paradigm which exploits the source statistics at the decoder side to reduce the complexity at the encoder. The coding efficiency of DVC critically depends on the quality of side information generation and accuracy of noise modeling. This paper considers...... Transform Domain Wyner-Ziv (TDWZ) coding and proposes using optical flow to improve side information generation and clustering to improve noise modeling. The optical flow technique is exploited at the decoder side to compensate weaknesses of block based methods, when using motion-compensation to generate...... side information frames. Clustering is introduced to capture cross band correlation and increase local adaptivity in the noise modeling. This paper also proposes techniques to learn from previously decoded (WZ) frames. Different techniques are combined by calculating a number of candidate soft side...

Complex Time-Delay Systems Theory and Applications

CERN Document Server

Atay, Fatihcan M

2010-01-01

Time delays in dynamical systems arise as an inevitable consequence of finite speeds of information transmission. Realistic models increasingly demand the inclusion of delays in order to properly understand, analyze, design, and control real-life systems. The goal of this book is to present the state-of-the-art in research on time-delay dynamics in the framework of complex systems and networks. While the mathematical theory of delay equations is quite mature, its application to the particular problems of complex systems and complexity is a newly emerging field, and the present volume aims to play a pioneering role in this perspective. The chapters in this volume are authored by renowned experts and cover both theory and applications in a wide range of fields, with examples extending from neuroscience and biology to laser physics and vehicle traffic. Furthermore, all chapters include sufficient introductory material and extensive bibliographies, making the book a self-contained reference for both students and ...

Stability and delay sensitivity of neutral fractional-delay systems.

Science.gov (United States)

Xu, Qi; Shi, Min; Wang, Zaihua

2016-08-01

This paper generalizes the stability test method via integral estimation for integer-order neutral time-delay systems to neutral fractional-delay systems. The key step in stability test is the calculation of the number of unstable characteristic roots that is described by a definite integral over an interval from zero to a sufficient large upper limit. Algorithms for correctly estimating the upper limits of the integral are given in two concise ways, parameter dependent or independent. A special feature of the proposed method is that it judges the stability of fractional-delay systems simply by using rough integral estimation. Meanwhile, the paper shows that for some neutral fractional-delay systems, the stability is extremely sensitive to the change of time delays. Examples are given for demonstrating the proposed method as well as the delay sensitivity.

Bridging Inter-flow and Intra-flow Network Coding for Video Applications

DEFF Research Database (Denmark)

Hansen, Jonas; Krigslund, Jeppe; Roetter, Daniel Enrique Lucani

2013-01-01

transmission approach to decide how much and when to send redundancy in the network, and a minimalistic feedback mechanism to guarantee delivery of generations of the different flows. Given the delay constraints of video applications, we proposed a simple yet effective coding mechanism, Block Coding On The Fly...

The Web 2.0 concept of urban disaster information in Taipei city: Mobile application development

Science.gov (United States)

Tsai, Yuan-Fan; Chan, Chun-Hsiang; Wang, Han; Pan, Yun-Xing; Lin, Gine-Jie

2014-05-01

In recent years, due to the global warming and global climate anomaly, more and more disasters appear such as flood and debris flow. The disasters always cause loss of life and property. However, the cross-aged invention, smart phone, makes our life more conveniently for delivering lots of information instantly. This study uses Eclipse as the development platform, and designs the urban disaster information mobile Application (APP) which is for debris flow and flood in Taipei city area. In this study, an urban disaster information APP, Taipei Let You Know, has successfully developed under android development environment, combined disaster indicators and the warming value of disaster. In order to ameliorate official information delay problem, this APP not only shows official information, but also offers a WEB 2.0 platform for public users to upload all disaster information instantly. As the result, the losses of life and property can decrease, and the disaster information delivery can be faster and more accurate by utilizing this APP in the future.

Eye movements in interception with delayed visual feedback.

Science.gov (United States)

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

2018-04-19

The increased reliance on electronic devices such as smartphones in our everyday life exposes us to various delays between our actions and their consequences. Whereas it is known that people can adapt to such delays, the mechanisms underlying such adaptation remain unclear. To better understand these mechanisms, the current study explored the role of eye movements in interception with delayed visual feedback. In two experiments, eye movements were recorded as participants tried to intercept a moving target with their unseen finger while receiving delayed visual feedback about their own movement. In Experiment 1, the target randomly moved in one of two different directions at one of two different velocities. The delay between the participant's finger movement and movement of the cursor that provided feedback about the finger movements was gradually increased. Despite the delay, participants followed the target with their gaze. They were quite successful at hitting the target with the cursor. Thus, they moved their finger to a position that was ahead of where they were looking. Removing the feedback showed that participants had adapted to the delay. In Experiment 2, the target always moved in the same direction and at the same velocity, while the cursor's delay varied across trials. Participants still always directed their gaze at the target. They adjusted their movement to the delay on each trial, often succeeding to intercept the target with the cursor. Since their gaze was always directed at the target, and they could not know the delay until the cursor started moving, participants must have been using peripheral vision of the delayed cursor to guide it to the target. Thus, people deal with delays by directing their gaze at the target and using both experience from previous trials (Experiment 1) and peripheral visual information (Experiment 2) to guide their finger in a way that will make the cursor hit the target.

Theory of attosecond delays in molecular photoionization.

Science.gov (United States)

Baykusheva, Denitsa; Wörner, Hans Jakob

2017-03-28

We present a theoretical formalism for the calculation of attosecond delays in molecular photoionization. It is shown how delays relevant to one-photon-ionization, also known as Eisenbud-Wigner-Smith delays, can be obtained from the complex dipole matrix elements provided by molecular quantum scattering theory. These results are used to derive formulae for the delays measured by two-photon attosecond interferometry based on an attosecond pulse train and a dressing femtosecond infrared pulse. These effective delays are first expressed in the molecular frame where maximal information about the molecular photoionization dynamics is available. The effects of averaging over the emission direction of the electron and the molecular orientation are introduced analytically. We illustrate this general formalism for the case of two polyatomic molecules. N 2 O serves as an example of a polar linear molecule characterized by complex photoionization dynamics resulting from the presence of molecular shape resonances. H 2 O illustrates the case of a non-linear molecule with comparably simple photoionization dynamics resulting from a flat continuum. Our theory establishes the foundation for interpreting measurements of the photoionization dynamics of all molecules by attosecond metrology.

Delayed neutrons in liquid metal spallation targets

International Nuclear Information System (INIS)

Ridikas, D.; Bokov, P.; David, J.C.; Dore, D.; Giacri, M.L.; Van Lauwe, A.; Plukiene, R.; Plukis, A.; Ignatiev, S.; Pankratov, D.

2003-01-01

The next generation spallation neutron sources, neutrino factories or RIB production facilities currently being designed and constructed around the world will increase the average proton beam power on target by a few orders of magnitude. Increased proton beam power results in target thermal hydraulic issues leading to new target designs, very often based on flowing liquid metal targets such as Hg, Pb, Pb-Bi. Radioactive nuclides produced in liquid metal targets are transported into hot cells, past electronics, into pumps with radiation sensitive components, etc. Besides the considerable amount of photon activity in the irradiated liquid metal, a significant amount of the delayed neutron precursor activity can be accumulated in the target fluid. The transit time from the front of a liquid metal target into areas, where delayed neutrons may be important, can be as short as a few seconds, well within one half-life of many delayed neutron precursors. Therefore, it is necessary to evaluate the total neutron flux (including delayed neutrons) as a function of time and determine if delayed neutrons contribute significantly to the dose rate. In this study the multi-particle transport code MCNPX combined with the material evolution program CINDER'90 will be used to evaluate the delayed neutron flux and spectra. The following scientific issues will be addressed in this paper: - Modeling of a typical geometry of the liquid metal spallation target; - Predictions of the prompt neutron fluxes, fission fragment and spallation product distributions; - Comparison of the above parameters with existing experimental data; - Time-dependent calculations of delayed neutron precursors; - Neutron flux estimates due to the prompt and delayed neutron emission; - Proposal of an experimental program to measure delayed neutron spectra from high energy spallation-fission reactions. The results of this study should be directly applicable in the design study of the European MegaPie (1 MW

Assessment of blood stasis in left-atrial appendage with electron-beam CT: filling delay in atrial fibrillation

International Nuclear Information System (INIS)

Nakanishi, Tadashi; Hamada, Seiki; Takamiya, Makoto; Kuribayashi, Sachio; Naito, Hiroaki

1994-01-01

The left-atrial appendage (LAA) is the most frequent site of thrombus formation. The most probable reason is its anatomical structure and blood stasis. We hypothesized that peak time delay should occur in the LAA with stagnant blood flow. We measured peak time delay in LAA against left atrium with the flow-mode study of electron-beam CT for 49 patients (including 23 patients with atrial fibrillation [AF]). Volume-mode scannings were also performed to detect intracardiac thrombi. Patients with atrial fibrillation showed a larger value than those with sinus rhythm. Some AF patients with no filling of contrast media into the LAA and/or thrombus showed a larger value than the others. The value obtained by the flow-mode study might have the potential by the flow-mode study might have the potential to assess blood stasis and to predict the jeopardized state in the LAA. (orig.)

Assessment of blood stasis in left-atrial appendage with electron-beam CT: filling delay in atrial fibrillation

Energy Technology Data Exchange (ETDEWEB)

Nakanishi, Tadashi [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Hamada, Seiki [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Takamiya, Makoto [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Kuribayashi, Sachio [Dept. of Radiology, National Cardiovascular Center, Suita, Osaka (Japan); Naito, Hiroaki [Biomedical Research Center, Osaka Univ. School of Medicine, Suita (Japan)

1994-10-01

The left-atrial appendage (LAA) is the most frequent site of thrombus formation. The most probable reason is its anatomical structure and blood stasis. We hypothesized that peak time delay should occur in the LAA with stagnant blood flow. We measured peak time delay in LAA against left atrium with the flow-mode study of electron-beam CT for 49 patients (including 23 patients with atrial fibrillation [AF]). Volume-mode scannings were also performed to detect intracardiac thrombi. Patients with atrial fibrillation showed a larger value than those with sinus rhythm. Some AF patients with no filling of contrast media into the LAA and/or thrombus showed a larger value than the others. The value obtained by the flow-mode study might have the potential by the flow-mode study might have the potential to assess blood stasis and to predict the jeopardized state in the LAA. (orig.)

A flow-control mechanism for distributed systems

Science.gov (United States)

Maitan, J.

1991-01-01

A new approach to the rate-based flow control in store-and-forward networks is evaluated. Existing methods display oscillations in the presence of transport delays. The proposed scheme is based on the explicit use of an embedded dynamic model of a store-and-forward buffer in a controller's feedback loop. It is shown that the use of the model eliminates the oscillations caused by the transport delays. The paper presents simulation examples and assesses the applicability of the scheme in the new generation of high-speed photonic networks where transport delays must be considered.

Delay-Induced Consensus and Quasi-Consensus in Multi-Agent Dynamical Systems

NARCIS (Netherlands)

Yu, Wenwu; Chen, Guanrong; Cao, Ming; Ren, Wei

2013-01-01

This paper studies consensus and quasi-consensus in multi-agent dynamical systems. A linear consensus protocol in the second-order dynamics is designed where both the current and delayed position information is utilized. Time delay, in a common perspective, can induce periodic oscillations or even

Delay in treatment seeking of smear positive tuberculous patients

International Nuclear Information System (INIS)

Bhatti, A.T.; Zahid, M.

2010-01-01

To assess and identify the causes and circumstances leading to delays in health seeking and diagnosis of tuberculosis patients as they often present with advance disease resulting in increased morbidity and mortality. Settings Department of Tuberculosis, DOTS clinic DHQ Hospital, Vehari. Methodology One (author) inspiration diagnosed smear positive pulmonary tuberculosis patients were included. Information was gathered through interviews and from TB-01 card. Results Maximum patients were in age group of 16-40 years. Median patient delay was 4-6 months; jobless, homeless personnel had longer delay. The main reason for delay was that the symptoms were not considered serious enough. Delay in presentation of smear positive cases may be due to the lack of awareness of patients and the incompetence of some health workers. Training and supervision of staff and awareness campaigns targeted at the population and involvement of private sector will improve TB control in Vehari. (author)

Conversational flow promotes solidarity.

Science.gov (United States)

Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H

2013-01-01

Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here). The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay). Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition) increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

Conversational flow promotes solidarity.

Directory of Open Access Journals (Sweden)

Namkje Koudenburg

Full Text Available Social interaction is fundamental to the development of various aspects of "we-ness". Previous research has focused on the role the content of interaction plays in establishing feelings of unity, belongingness and shared reality (a cluster of variables referred to as solidarity here. The present paper is less concerned with content, but focuses on the form of social interaction. We propose that the degree to which conversations flow smoothly or not is, of itself, a cue to solidarity. We test this hypothesis in samples of unacquainted and acquainted dyads who communicate via headsets. Conversational flow is disrupted by introducing a delay in the auditory feedback (vs. no delay. Results of three studies show that smoothly coordinated conversations (compared with disrupted conversations and a control condition increase feelings of belonging and perceptions of group entitativity, independently of conversation content. These effects are driven by the subjective experience of conversational flow. Our data suggest that this process occurs largely beyond individuals' control. We conclude that the form of social interaction is a powerful cue for inferring group solidarity. Implications for the impact of modern communication technology on developing a shared social identity are discussed.

Factors influencing diagnosis delay of advanced breast cancer in Moroccan women.

Science.gov (United States)

Maghous, A; Rais, F; Ahid, S; Benhmidou, N; Bellahamou, K; Loughlimi, H; Marnouche, E; Elmajjaoui, S; Elkacemi, H; Kebdani, T; Benjaafar, N

2016-06-07

Delay in the diagnosis of breast cancer in symptomatic women of 3 months or more is associated with advanced stage and low survival. We conducted this study to learn more about the extent and reasons behind diagnosis delay of advanced breast cancer in Moroccan women. A group of patients with advanced breast cancer were interviewed at the National Institute of Oncology in Rabat during the period from February to December 2014. Diagnosis delay was devised into patient delay and system delay. Patient delay was defined as time from first symptoms until first medical consultation. System delay was defined as time from first presentation to a health care provider until definite diagnosis or treatment. Prospective information and clinical data were collected on a form during an interview with each patient and from medical records. In all, 137 patients were interviewed. The mean age of women was 48.3 ± 10.4 years. The median of consultation time was 6[4,12] months and the median of diagnosis time was 1[1,3] months. Diagnosis delay was associated to a personal reason in 96 (70.1 %) patients and to a medical reason in 19 (13.9 %) patients. A number of factors predicted diagnosis delay: symptoms were not considered serious in 66 (55.9 %) patients; traditional therapy was applied in 15 (12.7 %) patients and fear of cancer diagnosis and/or treatment in 14 (11.9 %) patients. A use of traditional methods was significantly associated with rural residence and far away from basic health center (p = 0.000). Paradoxically, a family history of breast cancer was significantly higher in who report a fear of cancer diagnosis and/or treatment to diagnosis delay (p Diagnosis delay is very serious problem in Morocco. Diagnosis delay was associated with complex interactions between several factors and with advanced stages. There is a need for improving breast cancer information in our populations and training of general practitioners to reduce advanced breast cancer by

Modified Beer-Lambert law for blood flow.

Science.gov (United States)

Baker, Wesley B; Parthasarathy, Ashwin B; Busch, David R; Mesquita, Rickson C; Greenberg, Joel H; Yodh, A G

2014-11-01

We develop and validate a Modified Beer-Lambert law for blood flow based on diffuse correlation spectroscopy (DCS) measurements. The new formulation enables blood flow monitoring from temporal intensity autocorrelation function data taken at single or multiple delay-times. Consequentially, the speed of the optical blood flow measurement can be substantially increased. The scheme facilitates blood flow monitoring of highly scattering tissues in geometries wherein light propagation is diffusive or non-diffusive, and it is particularly well-suited for utilization with pressure measurement paradigms that employ differential flow signals to reduce contributions of superficial tissues.

Spiking Activity of a LIF Neuron in Distributed Delay Framework

Directory of Open Access Journals (Sweden)

Saket Kumar Choudhary

2016-06-01

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

Congenital rubella syndrome and delayed manifestations

DEFF Research Database (Denmark)

Dammeyer, Jesper Herup

2010-01-01

Objective: Several hypotheses of different medical and psychological delayed manifestations among people who have congenital rubella syndrome (CRS) have been discussed. This study tests some of these hypotheses of delayed manifestations. Methods: Gathering information about 35 individuals who hav...... which people with CRS face must primarily be understood in relation to congenital deafblindness and dual sensory and communicative deprivation....... CRS and who are congenitally deafblind. Results: None of the hypotheses could be confirmed when individuals with CRS were compared to a control group of individuals who were congenital deafblind with different aetiology than CRS. Conclusions: This study concludes that those health related problems...

Gain scheduling for non-linear time-delay systems using approximated model

NARCIS (Netherlands)

Pham, H.T.; Lim, J.T

2012-01-01

The authors investigate a regulation problem of non-linear systems driven by an exogenous signal and time-delay in the input. In order to compensate for the input delay, they propose a reduction transformation containing the past information of the control input. Then, by utilising the Euler

Control-based method to identify underlying delays of a nonlinear dynamical system.

Science.gov (United States)

Yu, Dongchuan; Frasca, Mattia; Liu, Fang

2008-10-01

We suggest several stationary state control-based delay identification methods which do not require any structural information about the controlled systems and are applicable to systems described by delayed ordinary differential equations. This proposed technique includes three steps: (i) driving a system to a steady state; (ii) perturbing the control signal for shifting the steady state; and (iii) identifying all delays by detecting the time that the system is abruptly drawn out of stationarity. Some aspects especially important for applications are discussed as well, including interaction delay identification, stationary state convergence speed, performance comparison, and the influence of noise on delay identification. Several examples are presented to illustrate the reliability and robustness of all delay identification methods suggested.

Functions of delay-period activity in the prefrontal cortex and mnemonic scotomas revisited

Directory of Open Access Journals (Sweden)

Shintaro eFunahashi

2015-02-01

Full Text Available Working memory is one of key concepts to understand functions of the prefrontal cortex. Delay-period activity is an important neural correlate to understand the role of working memory in prefrontal functions. The importance of delay-period activity is that this activity can encode not only visuospatial information but also a variety of information including non-spatial visual features, auditory and tactile stimuli, task rules, expected reward, and numerical quantity. This activity also participates in a variety of information processing including sensory-to-motor information transformation. These mnemonic features of delay-period activity enable to perform various important operations that the prefrontal cortex participates in, such as executive controls, and therefore, support the notion that working memory is an important function to understand prefrontal functions. On the other hand, although experiments using manual versions of the delayed-response task had revealed many important findings, an oculomotor version of this task enabled us to use multiple cue positions, exclude postural orientation during the delay period, and further prove the importance of mnemonic functions of the prefrontal cortex. In addition, monkeys with unilateral lesions exhibited specific impairment only in the performance of memory-guided saccades directed toward visual cues in the visual field contralateral to the lesioned hemisphere. This result indicates that memories for visuospatial coordinates in each hemifield are processed primarily in the contralateral prefrontal cortex. This result further strengthened the idea of mnemonic functions of the prefrontal cortex. Thus, the mnemonic functions of the prefrontal cortex and delay-period activity may not need to be reconsidered, but should be emphasized.

Distributed optimisation problem with communication delay and external disturbance

Science.gov (United States)

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

2017-12-01

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

The interaction evolution model of mass incidents with delay in a social network

Science.gov (United States)

Huo, Liang'an; Ma, Chenyang

2017-10-01

Recent years have witnessed rapid development of information technology. Today, modern media is widely used for the purpose of spreading information rapidly and widely. In particular, through micro-blog promotions, individuals tend to express their viewpoints and spread information on the internet, which could easily lead to public opinions. Moreover, government authorities also disseminate official information to guide public opinion and eliminate any incorrect conjecture. In this paper, a dynamical model with two delays is investigated to exhibit the interaction evolution between the public and official opinion fields in network mass incidents. Based on the theory of differential equations, the interaction mechanism between two public opinion fields in a micro-blog environment is analyzed. Two delays are proposed in the model to depict the response delays of public and official opinion fields. Some stable conditions are obtained, which shows that Hopf bifurcation can occur as delays cross critical values. Further, some numerical simulations are carried out to verify theoretical results. Our model indicates that there exists a golden time for government intervention, which should be emphasized given the impact of modern media and inaccurate rumors. If the government releases official information during the golden time, mass incidents on the internet can be controlled effectively.

Experimental study of transition from laminar to turbulent flow in vertical narrow channel

International Nuclear Information System (INIS)

Wang Chang; Gao Puzhen; Wang Zhanwei; Tan Sichao

2012-01-01

Highlights: ► The effect of wall heating on the laminar to turbulent transition is experimentally studied. ► The flow characteristic demonstrates that heating leads to the delay of transition from laminar to turbulent regimes. ► The heat transfer characteristics also indicates that heating leads to the delay of flow regime transition. - Abstract: Experimental investigation of flow and heat transfer characteristics of a vertical narrow channel with uniform heat flux condition are conducted to analysis the effect of wall heating on the laminar to turbulent transition. The friction factor in the heating condition is compared with that in the adiabatic condition and the results show that wall heating leads to the delay of laminar to turbulent transition. In addition, the heat transfer characteristic indicates that the critical Reynolds number at the point of laminar flow breakdown increases with the increase of fluid temperature difference, and the local Nusselt number at the point of laminar breakdown increases with the increase of the inlet Reynolds number. The analyses of the flow and heat transfer characteristics both indicate that the heating has a stabilizing effect on the water flow at present experimental scale.

Intraventricular flow alterations due to dyssynchronous wall motion

Science.gov (United States)

Pope, Audrey M.; Lai, Hong Kuan; Samaee, Milad; Santhanakrishnan, Arvind

2015-11-01

Roughly 30% of patients with systolic heart failure suffer from left ventricular dyssynchrony (LVD), in which mechanical discoordination of the ventricle walls leads to poor hemodynamics and suboptimal cardiac function. There is currently no clear mechanistic understanding of how abnormalities in septal-lateral (SL) wall motion affects left ventricle (LV) function, which is needed to improve the treatment of LVD using cardiac resynchronization therapy. We use an experimental flow phantom with an LV physical model to study mechanistic effects of SL wall motion delay on LV function. To simulate mechanical LVD, two rigid shafts were coupled to two segments (apical and mid sections) along the septal wall of the LV model. Flow through the LV model was driven using a piston pump, and stepper motors coupled to the above shafts were used to locally perturb the septal wall segments relative to the pump motion. 2D PIV was used to examine the intraventricular flow through the LV physical model. Alterations to SL delay results in a reduction in the kinetic energy (KE) of the flow field compared to synchronous SL motion. The effect of varying SL motion delay from 0% (synchronous) to 100% (out-of-phase) on KE and viscous dissipation will be presented. This research was supported by the Oklahoma Center for Advancement of Science and Technology (HR14-022).

A Prototype of Tropospheric Delay Correction in L1-SAIF Augmentation

Science.gov (United States)

Takeichi, Noboru; Sakai, Takeyasu; Fukushima, Sounosuke; Ito, Ken

L1-SAIF signal is one of the navigation signals of Quasi-Zenith Satellite System, which provides an augmentation function for mobile users in Japan. This paper presents the detail of the tropospheric delay correction in L1-SAIF augmentation. The tropospheric delay correction information is generated at the ground station using the data collected at GEONET (GPS Earth Observation NETwork) stations. The correction message contains the information of the zenith tropospheric delay (ZTD) values at 105 Tropospheric Grid Points (TGP) in the experiment area. From this message a mobile user can acquire the ZTD value at some neighboring TGPs, and estimate the local ZTD value accurately by using a suitable ZTD model function. Only 3 L1-SAIF messages are necessary to provide all of the tropospheric correction information. Several investigations using the actual data observed at many GEONET stations overall Japan have proved that it is possible to achieve the correction accuracy of 13.2mm (rms).

Time delay control of power converters: Mixed frame and stationary-frame variants

DEFF Research Database (Denmark)

Blaabjerg, Frede; Loh, P.C.; Tang, Y.

2008-01-01

In this paper, a mixed-frame and a stationary-frame time delay current controller are proposed for high precision reference tracking and disturbance rejection of power converters. In particular, the controllers use a proportional-resonant regulator in the stationary frame for regulating...... the positive and negative-sequence fundamental currents, which are known to directly influence the flow of active and reactive power in most energy conversion systems. Moreover, for the tracking or compensation of harmonics, the controllers include a time delay control path in either the synchronous...... or stationary frame, whose inherent feedback and feedforward structure can be proven to resemble a bank of resonant filters in either reference frames. Unlike other existing controllers, the proposed time delay controllers function by introducing multiple resonant peaks at only those harmonic frequencies...

Fuzzy delay model based fault simulator for crosstalk delay fault test ...

Indian Academy of Sciences (India)

In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design trends move towards nanometer technologies, more number of new parameters affects the delay of the component. Fuzzy delay models are ideal for modelling the uncertainty found in the design and manufacturing steps.

Delay-dependent exponential stability analysis of bi-directional associative memory neural networks with time delay: an LMI approach

International Nuclear Information System (INIS)

Li Chuandong; Liao Xiaofeng; Zhang Rong

2005-01-01

For bi-directional associative memory (BAM) neural networks (NNs) with different constant or time-varying delays, the problems of determining the exponential stability and estimating the exponential convergence rate are investigated in this paper. An approach combining the Lyapunov-Krasovskii functional with the linear matrix inequality (LMI) is taken to study the problems, which provide bounds on the interconnection matrix and the activation functions, so as to guarantee the system's exponential stability. Some criteria for the exponential stability, which give information on the delay-dependent property, are derived. The results obtained in this paper provide one more set of easily verified guidelines for determining the exponential stability of delayed BAM (DBAM) neural networks, which are less conservative and less restrictive than the ones reported so far in the literature. Some typical examples are presented to show the application of the criteria obtained in this paper

Test and Diagnosis for Small-Delay Defects

CERN Document Server

Tehranipoor, Mohammad; Chakrabarty, Krishnendu

2012-01-01

This book introduces new techniques for detecting and diagnosing small-delay defects (SDD) in integrated circuits. Although this sort of timing defect is commonly found in integrated circuits manufactured with nanometer technology, this will be the first book to introduce effective and scalable methodologies for screening and diagnosing small-delay defects, including important parameters such as process variations, crosstalk, and power supply noise. This book presents new techniques and methodologies to improve overall SDD detection with very small pattern sets. These methods can result in pattern counts as low as a traditional 1-detect pattern set and long path sensitization and SDD detection similar to or even better than n-detect or timing-aware pattern sets. The important design parameters and pattern-induced noises such as process variations,power supply noise (PSN) and crosstalk are taken into account in the methodologies presented. A diagnostic flow is also presented to identify whether the failure is ...

Flight delay performance at Hartsfield-Jackson Atlanta International Airport

Directory of Open Access Journals (Sweden)

Grigoriy Yablonsky

2014-01-01

Full Text Available Purpose: The main objective of this paper is to determine the annual cyclical flight delays at Hartsfield-Jackson Atlanta International Airport. Then using other data such as annual precipitation, passenger and aircraft traffic volumes and other factors, we attempted to correlate these factors with overall delays. These data could assist airport management in predicting periods of flight delay.Design/methodology/approach: Data were taken and analyzed from the data base “Research and Innovation Technology Administration” (RITA for the years 2005-2011 for Hartsfield-Jackson Atlanta International Airport. The data included 2.8 million flights originating and departing from this airport. Data were also gathered from the National Oceanic and Atmospheric Administration (NOAA showing precipitation. Additional data were gathered from the FAA regarding delay causes, number and types of delays and changes to the infrastructure of ATL airportFindings: There is a repeatable annual pattern of delays at ATL that can be modeled using delay data from the Bureau of Transportation Statistics. This pattern appears to be caused primarily by the frequency and amount of precipitation that falls at ATL and by the amount of flights that arrive and depart at ATL.Originality/value: This information could assist airport operations personnel, FAA air traffic controllers and airlines in anticipating and mitigating delays at specific times of the year.

Application of a film flow model to predicting burnout under transient conditions

International Nuclear Information System (INIS)

Leslie, D.C.; Kirby, G.J.

1967-08-01

The film flow model developed previously has been generalised to transient situations by assuming that only convection is changed by the transient; evaporation, deposition and entrainment are assumed to be unaffected. A computer code TRABUT computes the time behaviour of the mass velocity and the quality by the method of characteristics, and then integrates the film flow equations along the same characteristics until the point of burn-out or zero film flow is reached. The time delay between the onset of a transient and burn-out has been computed both for flux and flow transients. These computations have been compared with those made using the standard local conditions hypothesis. The film flow model gives shorter delays in almost all cases, but the difference would not be detectable with present experimental techniques. (author)

Online Scheduling in Manufacturing A Cumulative Delay Approach

CERN Document Server

Suwa, Haruhiko

2013-01-01

Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

CALINX (California Information Exchange): a multi-stakeholder statewide initiative to improve healthcare information flows.

Science.gov (United States)

Hopkins, D S; Oswald, N; McCaffrey, K; Bressler, S; Davidson, N; Vela, L

2000-01-01

Given the diffusion of responsibilities for gathering and reporting healthcare information in a managed care environment, California stakeholders are taking concrete steps to break the deadlock on data and information flows that has characterized the industry for some time. The California Information Exchange (CALINX) was established to facilitate the implementation of the Health Insurance Portability and Accountability Act (HIPAA) standards in California and to create trust for data exchange between trading partners, without which data exchange still will not occur. Strategic directions are set by the chief executives of key associations and organizations representing purchasers, plans, providers, and consumers. Multi-stakeholder workgroups have produced detailed data guidelines for the HIPAA standards along with rules for exchange of key data sets between trading partners. These rules address frequency, timeliness, and accuracy of data submission. Both the data guidelines and the rules have been tested in live demonstration projects, and the results of these projects have been reported to substantiate the business case for implementation. Further incentives are being built into contracts between purchasers and plans, and between plans and providers. CALINX is currently promoting widespread adoption of the data guidelines and rules for exchange with all members of the industry.

Development of Methods for Obtaining Position Image and Chemical Binding Information from Flow Experiments of Porous Media

Energy Technology Data Exchange (ETDEWEB)

Haugan, Are

1998-12-01

Existing oil reservoirs might be more fully exploited if the properties of the flow of oil and water in porous media were better known. In laboratory experiments it is important to collect as much information as possible to make a descriptive model of the system, including position imaging and chemical binding information. This thesis develops nuclear methods for obtaining position image and chemical binding information from flow experiments of porous media. A combined positron emission tomography and single photon emission computed tomography system to obtain position images, and a time-differential perturbed angular correlation system to obtain chemical binding information, have been built and thoroughly tested. 68 refs., 123 figs., 14 tabs.

Delay generation methods with reduced memory requirements

DEFF Research Database (Denmark)

Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

2003-01-01

Modern diagnostic ultrasound beamformers require delay information for each sample along the image lines. In order to avoid storing large amounts of focusing data, delay generation techniques have to be used. In connection with developing a compact beamformer architecture, recursive algorithms were......) For the best parametric approach, the gate count was 2095, the maximum operation speed was 131.9 MHz, the power consumption at 40 MHz was 10.6 mW, and it requires 4 12-bit words for each image line and channel. 2) For the piecewise-linear approximation, the corresponding numbers are 1125 gates, 184.9 MHz, 7...

On the cost/delay tradeoff of wireless delay tolerant geographic routing

OpenAIRE

Tasiopoulos, Argyrios; Tsiaras, Christos; Toumpis, Stavros

2012-01-01

In Delay Tolerant Networks (DTNs), there is a fundamental tradeoff between the aggregate transport cost of a packet and the delay in its delivery. We study this tradeoff in the context of geographical routing in wireless DTNs.We ?rst specify the optimal cost/delay tradeoff, i.e., the tradeoff under optimal network operation, using a dynamic network construction termed the Cost/Delay Evolving Graph (C/DEG) and the Optimal Cost/Delay Curve (OC/DC), a function that gives the minimum possible agg...

Temporal-contextual processing in working memory: evidence from delayed cued recall and delayed free recall tests.

Science.gov (United States)

Loaiza, Vanessa M; McCabe, David P

2012-02-01

Three experiments are reported that addressed the nature of processing in working memory by investigating patterns of delayed cued recall and free recall of items initially studied during complex and simple span tasks. In Experiment 1, items initially studied during a complex span task (i.e., operation span) were more likely to be recalled after a delay in response to temporal-contextual cues, relative to items from subspan and supraspan list lengths in a simple span task (i.e., word span). In Experiment 2, items initially studied during operation span were more likely to be recalled from neighboring serial positions during delayed free recall than were items studied during word span trials. Experiment 3 demonstrated that the number of attentional refreshing opportunities strongly predicts episodic memory performance, regardless of whether the information is presented in a spaced or massed format in a modified operation span task. The results indicate that the content-context bindings created during complex span trials reflect attentional refreshing opportunities that are used to maintain items in working memory.

Detection and characterization of Budd-Chiari syndrome with inferior vena cava obstruction: Comparison of fixed and flexible delayed scan time of computed tomography venography.

Science.gov (United States)

Zhou, Peng-Li; Wu, Gang; Han, Xin-Wei; Bi, Yong-Hua; Zhang, Wen-Guang; Wu, Zheng-Yang

2017-06-01

To compare the results of computed tomography venography (CTV) with a fixed and a flexible delayed scan time for Budd-Chiari syndrome (BCS) with inferior vena cava (IVC) obstruction. A total of 209 consecutive BCS patients with IVC obstruction underwent either a CTV with a fixed delayed scan time of 180s (n=87) or a flexible delayed scan time for good image quality according to IVC blood flow in color Doppler ultrasonography (n=122). The IVC blood flow velocity was measured using a color Doppler ultrasound prior to CT scan. Image quality was classified as either good, moderate, or poor. Image quality, surrounding structures and the morphology of the IVC obstruction were compared between the two groups using a χ 2 -test or paired or unpaired t-tests as appropriate. Inter-observer agreement was assessed using Kappa statistics. There was no significant difference in IVC blood flow velocity between the two groups. Overall image quality, surrounding structures and IVC obstruction morphology delineation on the flexible delayed scan time of CTV images were rated better relative to those obtained by fixed delayed scan time of CTV images (ptime of CTV. There were no significant differences in Kappa statistics between Group A and Group B. The flexible delayed scan time of CTV was associated with better detection and more reliable characterization of BCS with IVC obstruction compared to a fixed delayed scan time. Copyright © 2017 Elsevier B.V. All rights reserved.

Leveraging delay discounting for health: Can time delays influence food choice?

Science.gov (United States)

Appelhans, Bradley M; French, Simone A; Olinger, Tamara; Bogucki, Michael; Janssen, Imke; Avery-Mamer, Elizabeth F; Powell, Lisa M

2018-03-15

Delay discounting, the tendency to choose smaller immediate rewards over larger delayed rewards, is theorized to promote consumption of immediately rewarding but unhealthy foods at the expense of long-term weight maintenance and nutritional health. An untested implication of delay discounting models of decision-making is that selectively delaying access to less healthy foods may promote selection of healthier (immediately available) alternatives, even if they may be less desirable. The current study tested this hypothesis by measuring healthy versus regular vending machine snack purchasing before and during the implementation of a 25-s time delay on the delivery of regular snacks. Purchasing was also examined under a $0.25 discount on healthy snacks, a $0.25 tax on regular snacks, and the combination of both pricing interventions with the 25-s time delay. Across 32,019 vending sales from three separate vending locations, the 25-s time delay increased healthy snack purchasing from 40.1% to 42.5%, which was comparable to the impact of a $0.25 discount (43.0%). Combining the delay and the discount had a roughly additive effect (46.0%). However, the strongest effects were seen under the $0.25 tax on regular snacks (53.7%) and the combination of the delay and the tax (50.2%). Intervention effects varied substantially between vending locations. Importantly, time delays did not harm overall vending sales or revenue, which is relevant to the real-world feasibility of this intervention. More investigation is needed to better understand how the impact of time delays on food choice varies across populations, evaluate the effects of time delays on beverage vending choices, and extend this approach to food choices in contexts other than vending machines. ClinicalTrials.gov, NCT02359916. Copyright © 2018 Elsevier Ltd. All rights reserved.

Simulating The Impact Of The Material Flow In The Jordanian Construction Supply Chain And Its Impact On Project Performance

Directory of Open Access Journals (Sweden)

Dr. Ghaith Al-Werikat

2017-03-01

Full Text Available With the new developments and challenges within the construction industry improving the construction supply chain is becoming a major concern to both governments and industries. Improving the construction supply chain helps in improving the quality of construction projects reducing cost wastes delays and other disruptions. This paper discusses the analysis of material flow in the construction supply chain. The methodology consisted of preliminary investigations survey and simulation development to analyse the extent of impact that material flow has on construction projects in Jordan. Both the main survey and the investigations revealed that material flow delays are caused mainly by 3 types of delays late delivery wrong specification and material damaged on site. The highest impact regarding late deliveries was scaffolding with a 16 probability of occurrence a 2-day delay on the activitys duration. Concrete ranked highest regarding wrong specification with a 19 probability of occurrence an 8-day delay the activitys duration. Regarding materials damaged on site bricks ranked highest with a 9 probability of occurrence a 3-day delay on the duration. The simulation results exhibited a delay of 50 on the projects duration and a probability of a delay occurring is 9.2.

Integration of three echelon supply chain (supplier-manufacturer-distributor-drop shipper) with permissible delay in payment and penalty contract

Science.gov (United States)

Ibrahim, M. F.; Suparno

2018-04-01

Supply Chain Management (SCM) has to be considered in the company in order to improve the sustainability and competitiveness. SCM executed to integrating any companies on the supply chain in a way of coordinating the flow of goods, information, and financial. Permissible delay in payment is one of the coordination ways with allowing the costumers delay the payments to a vendor in some certain periods without any interest charges. In the supply chain system, drop-shipping player already familiar in this era. In drop-shipping internet retailing, the supplier will hold supplies and also carry out physical distribution service on behalf of drop-shipper. Drop-shipper will just focus on selling, on the other hand, their supplier will be responsible for the physical process. Generally, drop-shipper have information of the customer demands better than the distributor. But, it is also unrare when the drop-shipper send the estimation of demands which bigger than their own estimation in order to maximize their own interest, so they hope supplies of the distributor will always enough to accommodate their demands. Contributions in this research will be focused on integration of three echelons supply chain, which are the supplier, manufacturer, distributor, and drop-shipper. With considering delay in payment on first and second echelons, and also the contract penalty on third echelon. The problem on this research will be modeled in some kind of cases which can represent the problem of real supply chain system. Sensitivity analysis will be done on certain significant variables toward the changes of total supply chain cost. Coordination with delay in payment success to integrate supply chain. Contract penalty plan success to maintain the profit of distributor and drop-shipper.

Information flow between interacting human brains: Identification, validation, and relationship to social expertise.

Science.gov (United States)

Bilek, Edda; Ruf, Matthias; Schäfer, Axel; Akdeniz, Ceren; Calhoun, Vince D; Schmahl, Christian; Demanuele, Charmaine; Tost, Heike; Kirsch, Peter; Meyer-Lindenberg, Andreas

2015-04-21

Social interactions are fundamental for human behavior, but the quantification of their neural underpinnings remains challenging. Here, we used hyperscanning functional MRI (fMRI) to study information flow between brains of human dyads during real-time social interaction in a joint attention paradigm. In a hardware setup enabling immersive audiovisual interaction of subjects in linked fMRI scanners, we characterize cross-brain connectivity components that are unique to interacting individuals, identifying information flow between the sender's and receiver's temporoparietal junction. We replicate these findings in an independent sample and validate our methods by demonstrating that cross-brain connectivity relates to a key real-world measure of social behavior. Together, our findings support a central role of human-specific cortical areas in the brain dynamics of dyadic interactions and provide an approach for the noninvasive examination of the neural basis of healthy and disturbed human social behavior with minimal a priori assumptions.

Survey of Media Forms and Information Flow Models in Microsystems Companies

Science.gov (United States)

Durugbo, Christopher; Tiwari, Ashutosh; Alcock, Jeffery R.

The paper presents the findings of a survey of 40 microsystems companies that was carried out to determine the use and the purpose of use of media forms and information flow models within these companies. These companies as 'product-service systems' delivered integrated products and services to realise customer solutions. Data collection was carried out by means of an online survey over 3 months. The survey revealed that 42.5% of respondents made use of data flow diagrams and 10% made use of design structure matrices. The survey also suggests that a majority of companies (75%) made use of textual and diagrammatic media forms for communication, analysis, documentation and representation during design and development processes. The paper also discusses the implications of the survey findings to product-service systems.

Statistical theory for calculating energy spectra of β-delayed neutrons

International Nuclear Information System (INIS)

Kawano, Toshihiko; Moeller, Peter; Wilson, William B.

2008-01-01

Theoretical β-delayed neutron spectra are calculated based on the Quasi-particle Random Phase Approximation (QRPA) and the Hauser-Feshbach statistical model. Neutron emissions from an excited daughter nucleus after β-decay to the granddaughter residual are more accurately calculated than previous evaluations, including all the microscopic nuclear structure information, such as a Gamow-Teller strength distribution and discrete states in the granddaughter. The calculated delayed-neutron spectra reasonably agree with those evaluations in the ENDF decay library, which are based on experimental data. The model was adopted to generate the delayed-neutron spectra for all 271 precursors. (authors)

Investigation into information flow during the accident at Three Mile Island

International Nuclear Information System (INIS)

1981-01-01

This report was prepared in response to a request from NRC Chairman Ahearne that directed the Office of Inspection and Enforcement to resume its investigation of information flow during the accident at Three Mile Island (TMI) that occurred on March 28, 1979. This investigation was resumed on March 21, 1980. The transfer of information among individuals, agencies, and personnel from Metropolitan Edison was analyzed to ascertain what knowledge was held by various individuals of the specific events, parameters, and systems during the accident at TMI. Maximum use was made of existing records, and additional interviews were conducted to clarify areas that had not been pursued during earlier investigations. Although the passage of time between the accident and post-accident interviews hampered precise recollections of events and circumstances, the investigation revealed that information was not intentionally withheld during the accident and that the system for effective transfer of information was inadequate during the accident

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

Directory of Open Access Journals (Sweden)

Philippe Jacquet

2007-01-01

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

Delay-related cerebral activity and motor preparation

NARCIS (Netherlands)

Mars, R.B.; Coles, M.G.H.; Hulstijn, W.

2008-01-01

Flexible goal-oriented behavior requires the ability to carry information across temporal delays. This ability is associated with sustained neural firing. In cognitive terms, this ability has often been associated with the maintenance of sensory material online, as during short-term memory tasks, or

Numerical simulation of flow around the NREL S826 airfoil at moderate Reynolds number using delayed detached Eddy simulation (DDES)

Science.gov (United States)

Prytz, Erik R.; Huuse, Øyvind; Müller, Bernhard; Bartl, Jan; Sætran, Lars Roar

2017-07-01

Turbulent flow at Reynolds numbers 5 . 104 to 106 around the NREL S826 airfoil used for wind turbine blades is simulated using delayed detached eddy simulation (DDES). The 3D domain is built as a replica of the low speed wind tunnel at the Norwegian University of Science and Technology (NTNU) with the wind tunnel walls considered as slip walls. The subgrid turbulent kinetic energy is used to model the sub-grid scale in the large eddy simulation (LES) part of DDES. Different Reynoldsaveraged Navier-Stokes (RANS) models are tested in ANSYS Fluent. The realizable k - ∈ model as the RANS model in DDES is found to yield the best agreement of simulated pressure distributions with the experimental data both from NTNU and the Technical University of Denmark (DTU), the latter for a shorter spanwise domain. The present DDES results are in excellent agreement with LES results from DTU. Since DDES requires much fewer cells in the RANS region near the wing surface than LES, DDES is computationally much more efficient than LES. Whereas DDES is able to predict lift and drag in close agreement with experiment up to stall, pure 2D RANS simulations fail near stall. After testing different numerical settings, time step sizes and grids for DDES, a Reynolds number study is conducted. Near stall, separated flow structures, so-called stall cells, are observed in the DDES results.

Identification method of gas-liquid two-phase flow regime based on image wavelet packet information entropy and genetic neural network

International Nuclear Information System (INIS)

Zhou Yunlong; Chen Fei; Sun Bin

2008-01-01

Based on the characteristic that wavelet packet transform image can be decomposed by different scales, a flow regime identification method based on image wavelet packet information entropy feature and genetic neural network was proposed. Gas-liquid two-phase flow images were captured by digital high speed video systems in horizontal pipe. The information entropy feature from transformation coefficients were extracted using image processing techniques and multi-resolution analysis. The genetic neural network was trained using those eigenvectors, which was reduced by the principal component analysis, as flow regime samples, and the flow regime intelligent identification was realized. The test result showed that image wavelet packet information entropy feature could excellently reflect the difference between seven typical flow regimes, and the genetic neural network with genetic algorithm and BP algorithm merits were with the characteristics of fast convergence for simulation and avoidance of local minimum. The recognition possibility of the network could reach up to about 100%, and a new and effective method was presented for on-line flow regime. (authors)

Stable Formation Control of Multi-Robot System with Communication Delay

Directory of Open Access Journals (Sweden)

Limei Jiang

2012-03-01

Full Text Available In this paper, a distributed formation control algorithm with delayed information exchange is discussed. The algorithm, which is derived from the flocking behaviour of birds and consensus theory, enables robots to move in formation at a desired velocity. After a series of orthogonal transformations to the original formation system, the upper bound tolerable delay is obtained by using matrix theory and the Nyquist criterion. According to the results, the upper bound tolerable delay depends on the control parameters and eigenvalues of the Laplacian matrix. Therefore, the effect of the parameters on the maximum tolerable delay is analysed, obtaining the following conclusions: the upper bound tolerable delay is proportional to the parameters associated with the velocity, inversely proportional to the parameters associated with the position, and inversely proportional to the difference between the eigenvalue of Laplacian matrix and 1. The simulation results of a four-robot formation system with different communication delays verify the effectiveness of the formation control algorithm and the correctness of the theoretical analysis.

Boundary delineation for regional groundwater flow through geographic information system (Contract research)

International Nuclear Information System (INIS)

Yamakawa, Tadashi; Munakata, Masahiro; Kimura, Hideo; Hyodo, Hiroshi

2007-03-01

Radionuclide migration toward the human environment is to be assessed as the part of long-term safety assessments of geologic disposal of radioactive waste. Geologic processes, which include volcanic activity, hydrothermal activity, seismicity and deformation, bring about hydrogeologic changes in the regional groundwater flow system around a repository site. Groundwater flow systems in Japan have been studied in several sites such as Tono mine, Kamaishi mine and Horonobe area, but methodology of studies in these sites does not have fully developed. This study was conducted to develop methodologies of boundary delineation for regional groundwater flow systems. Geographic Information System, GIS, was applied using available topographic, hydrologic and geologic data for an area of interest. Miyakoji in the Abukuma Mountains was selected as the area, for the reason of its simple geologic setting formed by granitic rocks and topographically gentle hills of drainage basin. Data used in this study cover topographic sheets, digital elevation model, satellite imagery, geologic maps, topographic classification maps, soil distribution maps and landuse maps. Through the GIS techniques using these data, thematic maps on topographic features, surface conditions, land coverage, geology and geologic structure and weathered crust were developed, and these thematic maps were further applied to extract four factors affecting the regional groundwater flows: topographic condition, precipitation recharge, fracture characteristics and potential flows. The present study revealed that, taking the potential groundwater flows and characteristics of fractured zones in the area into consideration, the groundwater flow system in Miyakoji drainage basin should be bounded by the Otakine Mountain and the northern part of Tokoha Drainage Basin. The delineated area is larger than understood before. (author)

Granger causality mapping during joint actions reveals evidence for forward models that could overcome sensory-motor delays.

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Idil Kokal

Full Text Available Studies investigating joint actions have suggested a central role for the putative mirror neuron system (pMNS because of the close link between perception and action provided by these brain regions [1], [2], [3]. In contrast, our previous functional magnetic resonance imaging (fMRI experiment demonstrated that the BOLD response of the pMNS does not suggest that it directly integrates observed and executed actions during joint actions [4]. To test whether the pMNS might contribute indirectly to the integration process by sending information to brain areas responsible for this integration (integration network, here we used Granger causality mapping (GCM [5]. We explored the directional information flow between the anterior sites of the pMNS and previously identified integrative brain regions. We found that the left BA44 sent more information than it received to both the integration network (left thalamus, right middle occipital gyrus and cerebellum and more posterior nodes of the pMNS (BA2. Thus, during joint actions, two anatomically separate networks therefore seem effectively connected and the information flow is predominantly from anterior to posterior areas of the brain. These findings suggest that the pMNS is involved indirectly in joint actions by transforming observed and executed actions into a common code and is part of a generative model that could predict the future somatosensory and visual consequences of observed and executed actions in order to overcome otherwise inevitable neural delays.

Inhibition of Information Flow to the Default Mode Network During Self-Reference Versus Reference to Others.

Science.gov (United States)

Soch, Joram; Deserno, Lorenz; Assmann, Anne; Barman, Adriana; Walter, Henrik; Richardson-Klavehn, Alan; Schott, Björn H

2017-08-01

The default mode network (DMN), a network centered around the cortical midline, shows deactivation during most cognitive tasks and pronounced resting-state connectivity, but is actively engaged in self-reference and social cognition. It is, however, yet unclear how information reaches the DMN during social cognitive processing. Here, we addressed this question using dynamic causal modeling (DCM) of functional magnetic resonance imaging (fMRI) data acquired during self-reference (SR) and reference to others (OR). Both conditions engaged the left inferior frontal gyrus (LIFG), most likely reflecting semantic processing. Within the DMN, self-reference preferentially elicited rostral anterior cingulate and ventromedial prefrontal cortex (rACC/vmPFC) activity, whereas OR engaged posterior cingulate and precuneus (PCC/PreCun). DCM revealed that the regulation of information flow to the DMN was primarily inhibitory. Most prominently, SR elicited inhibited information flow from the LIFG to the PCC/PreCun, while OR was associated with suppression of the connectivity from the LIFG to the rACC/vmPFC. These results suggest that task-related DMN activation is enabled by inhibitory down-regulation of task-irrelevant information flow when switching from rest to stimulus-specific processing. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Delayed fission

Energy Technology Data Exchange (ETDEWEB)

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

1997-07-01

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

Delay Tolerant Networking with Data Triage Method based on Emergent User Policies for Disaster Information Network System

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Noriki Uchida

2014-01-01

Full Text Available When Disaster Information Network System is considered in local areas that were heavy damaged by the East Japan Great Earthquake in 2011, the resiliency of the network system is one of significant subjects for the restoration of the areas. DTN (Delay Tolerant Network has been focused for the effective methods for such inoperable network circumstances. However, when DTN is applied for the local areas, there are some problems such as message delivery rate and latency because there are fewer roads, cars, and pedestrians than in urban areas. In this paper, we propose the Enhanced Media Coordinate System for its architecture, and Data Triage method by emergent user policies is introduced to improve the QoS in Disaster Information Network System in local areas. In the proposed method, every message is tagged with the priority levels by data types with considering emergent user policies, and the high priority messages are firstly duplicated to transmittable nodes. Then, the experimental results by the GIS map of a Japanese coastal town and the future studies are discussed.

Preparing a Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) compliant manuscript using the International Society for Advancement of Cytometry (ISAC) FCS file repository (FlowRepository.org).

Science.gov (United States)

Spidlen, Josef; Breuer, Karin; Brinkman, Ryan

2012-07-01

FlowRepository.org is a Web-based flow cytometry data repository provided by the International Society for Advancement of Cytometry (ISAC). It supports storage, annotation, analysis, and sharing of flow cytometry datasets. A fundamental tenet of scientific research is that published results should be open to independent validation and refutation. With FlowRepository, researchers can annotate their datasets in compliance with the Minimum Information about a Flow Cytometry Experiment (MIFlowCyt) standard, thus greatly facilitating third-party interpretation of their data. In this unit, we will mainly focus on the deposition, sharing, and annotation of flow cytometry data.

Delayed neutron spectra and their uncertainties in fission product summation calculations

Energy Technology Data Exchange (ETDEWEB)

Miyazono, T.; Sagisaka, M.; Ohta, H.; Oyamatsu, K.; Tamaki, M. [Nagoya Univ. (Japan)

1997-03-01

Uncertainties in delayed neutron summation calculations are evaluated with ENDF/B-VI for 50 fissioning systems. As the first step, uncertainty calculations are performed for the aggregate delayed neutron activity with the same approximate method as proposed previously for the decay heat uncertainty analyses. Typical uncertainty values are about 6-14% for {sup 238}U(F) and about 13-23% for {sup 243}Am(F) at cooling times 0.1-100 (s). These values are typically 2-3 times larger than those in decay heat at the same cooling times. For aggregate delayed neutron spectra, the uncertainties would be larger than those for the delayed neutron activity because much more information about the nuclear structure is still necessary. (author)

Time delay induced different synchronization patterns in repulsively coupled chaotic oscillators

Science.gov (United States)

Yao, Chenggui; Yi, Ming; Shuai, Jianwei

2013-09-01

Time delayed coupling plays a crucial role in determining the system's dynamics. We here report that the time delay induces transition from the asynchronous state to the complete synchronization (CS) state in the repulsively coupled chaotic oscillators. In particular, by changing the coupling strength or time delay, various types of synchronous patterns, including CS, antiphase CS, antiphase synchronization (ANS), and phase synchronization, can be generated. In the transition regions between different synchronous patterns, bistable synchronous oscillators can be observed. Furthermore, we show that the time-delay-induced phase flip bifurcation is of key importance for the emergence of CS. All these findings may light on our understanding of neuronal synchronization and information processing in the brain.

Development of a statistically based access delay timeline methodology.

Energy Technology Data Exchange (ETDEWEB)

Rivera, W. Gary; Robinson, David Gerald; Wyss, Gregory Dane; Hendrickson, Stacey M. Langfitt

2013-02-01

The charter for adversarial delay is to hinder access to critical resources through the use of physical systems increasing an adversarys task time. The traditional method for characterizing access delay has been a simple model focused on accumulating times required to complete each task with little regard to uncertainty, complexity, or decreased efficiency associated with multiple sequential tasks or stress. The delay associated with any given barrier or path is further discounted to worst-case, and often unrealistic, times based on a high-level adversary, resulting in a highly conservative calculation of total delay. This leads to delay systems that require significant funding and personnel resources in order to defend against the assumed threat, which for many sites and applications becomes cost prohibitive. A new methodology has been developed that considers the uncertainties inherent in the problem to develop a realistic timeline distribution for a given adversary path. This new methodology incorporates advanced Bayesian statistical theory and methodologies, taking into account small sample size, expert judgment, human factors and threat uncertainty. The result is an algorithm that can calculate a probability distribution function of delay times directly related to system risk. Through further analysis, the access delay analyst or end user can use the results in making informed decisions while weighing benefits against risks, ultimately resulting in greater system effectiveness with lower cost.

Simulation of queue length and vehicle delays on signal-controlled intersection

Directory of Open Access Journals (Sweden)

Leverents Evgeny

2018-01-01

Full Text Available The extensive use of information technology in the field of traffic control will increase the traffic capacity of intersection points and transports. To assess the efficacy of changing options for the road traffic organization or the reorganization of intersection points, you need to know the average delay in vehicles and the length of the queue. The adaptive traffic light control is one of such tools. Simulation modeling of traffic flows use for the definition of its work. The aim of this work is to create a simulation model of controlled intersection, which can evaluate the efficiency of the application the adaptive regulation in various traffic situations, including the availability or deficiency of pedestrian traffic through the intersection. The numerical experiment in in the model pass with using of the Monte Carlo method, which can to draw a conclusion about the calculated parameter on the basis of the result of the reproduction of the calculation model.

Delayed transitions in non-linear replicator networks: About ghosts and hypercycles

International Nuclear Information System (INIS)

Sardanyes, Josep; Sole, Ricard V.

2007-01-01

In this paper we analyze delayed transition phenomena associated to extinction thresholds in a mean field model for hypercycles composed of three and four units, respectively. Hence, we extend a previous analysis carried out with the two-membered hypercycle [see Sardanyes J, Sole RV. Ghosts in the origins of life? Int J Bifurcation Chaos 2006;16(9), in press]. The models we analyze show that, after the tangent bifurcation, these hypercycles also leave a ghost in phase space. These ghosts, which actually conserve the dynamical properties of the coalesced coexistence fixed point, delay the flows before hypercycle extinction. In contrast with the two-component hypercycle, both ghosts show a plateau in the delay as φ → 0, thus displacing the power-law dependence to higher values of φ, in which the scaling law is now given by τ ∼ φ β , with β = -1/3 (where τ is the delay and φ = ε - ε c , the parametric distance above the extinction bifurcation point). These results suggest that the presence of the ghost is a general property of hypercycles. Such ghosts actually cause a memory effect which might increase hypercycle survival chances in fluctuating environments

Phase-coherence transitions and communication in the gamma range between delay-coupled neuronal populations.

Directory of Open Access Journals (Sweden)

Alessandro Barardi

2014-07-01

Full Text Available Synchronization between neuronal populations plays an important role in information transmission between brain areas. In particular, collective oscillations emerging from the synchronized activity of thousands of neurons can increase the functional connectivity between neural assemblies by coherently coordinating their phases. This synchrony of neuronal activity can take place within a cortical patch or between different cortical regions. While short-range interactions between neurons involve just a few milliseconds, communication through long-range projections between different regions could take up to tens of milliseconds. How these heterogeneous transmission delays affect communication between neuronal populations is not well known. To address this question, we have studied the dynamics of two bidirectionally delayed-coupled neuronal populations using conductance-based spiking models, examining how different synaptic delays give rise to in-phase/anti-phase transitions at particular frequencies within the gamma range, and how this behavior is related to the phase coherence between the two populations at different frequencies. We have used spectral analysis and information theory to quantify the information exchanged between the two networks. For different transmission delays between the two coupled populations, we analyze how the local field potential and multi-unit activity calculated from one population convey information in response to a set of external inputs applied to the other population. The results confirm that zero-lag synchronization maximizes information transmission, although out-of-phase synchronization allows for efficient communication provided the coupling delay, the phase lag between the populations, and the frequency of the oscillations are properly matched.

Is Investment-Cash Flow Sensitivity Caused by the Agency Costs or Asymmetric Information? Evidence from the UK

NARCIS (Netherlands)

Pawlina, G.; Renneboog, L.D.R.

2005-01-01

We investigate the investment-cash flow sensitivity of a large sample of the UK listed firms and confirm that investment is strongly cash flow-sensitive.Is this suboptimal investment policy the result of agency problems when managers with high discretion overinvest, or of asymmetric information when

Fuzzy delay model based fault simulator for crosstalk delay fault test ...

Indian Academy of Sciences (India)

In this paper, a fuzzy delay model based crosstalk delay fault simulator is proposed. As design .... To find the quality of non-robust tests, a fuzzy delay ..... Dubois D and Prade H 1989 Processing Fuzzy temporal knowledge. IEEE Transactions ...

Multifractal chaotic attractors in a system of delay-differential equations modeling road traffic.

Science.gov (United States)

Safonov, Leonid A.; Tomer, Elad; Strygin, Vadim V.; Ashkenazy, Yosef; Havlin, Shlomo

2002-12-01

We study a system of delay-differential equations modeling single-lane road traffic. The cars move in a closed circuit and the system's variables are each car's velocity and the distance to the car ahead. For low and high values of traffic density the system has a stable equilibrium solution, corresponding to the uniform flow. Gradually decreasing the density from high to intermediate values we observe a sequence of supercritical Hopf bifurcations forming multistable limit cycles, corresponding to flow regimes with periodically moving traffic jams. Using an asymptotic technique we find approximately small limit cycles born at Hopf bifurcations and numerically preform their global continuations with decreasing density. For sufficiently large delay the system passes to chaos following the Ruelle-Takens-Newhouse scenario (limit cycles-two-tori-three-tori-chaotic attractors). We find that chaotic and nonchaotic attractors coexist for the same parameter values and that chaotic attractors have a broad multifractal spectrum. (c) 2002 American Institute of Physics.

Delayed power analysis

International Nuclear Information System (INIS)

Adamovich, L.A.; Azarov, V.V.

1999-01-01

Time dependent core power behavior in a nuclear reactor is described with well-known neutron kinetics equations. At the same time, two portions are distinguished in energy released from uranium nuclei fission; one released directly at fission and another delayed (residual) portion produced during radioactive decay of fission products. While prompt power is definitely described with kinetics equations, the delayed power presentation still remains outstanding. Since in operation the delayed power part is relatively small (about 6%) operation, it can be neglected for small reactivity disturbances assuming that entire power obeys neutron kinetics equations. In case of a high negative reactivity rapidly inserted in core (e.g. reactor scram initiation) the prompt and delayed components can be calculated separately with practically no impact on each other, employing kinetics equations for prompt power and known approximation formulas for delayed portion, named residual in this specific case. Under substantial disturbances the prompt component in the dynamic process becomes commensurable with delayed portion, thus making necessary to take into account their cross impact. A system of differential equations to describe time-dependent behavior of delayed power is presented. Specific NPP analysis shows a way to significantly simplify the task formulation. (author)

Inhibition delay increases neural network capacity through Stirling transform

Science.gov (United States)

Nogaret, Alain; King, Alastair

2018-03-01

Inhibitory neural networks are found to encode high volumes of information through delayed inhibition. We show that inhibition delay increases storage capacity through a Stirling transform of the minimum capacity which stabilizes locally coherent oscillations. We obtain both the exact and asymptotic formulas for the total number of dynamic attractors. Our results predict a (ln2) -N-fold increase in capacity for an N -neuron network and demonstrate high-density associative memories which host a maximum number of oscillations in analog neural devices.

Real-time traffic signal optimization model based on average delay time per person

Directory of Open Access Journals (Sweden)

Pengpeng Jiao

2015-10-01

Full Text Available Real-time traffic signal control is very important for relieving urban traffic congestion. Many existing traffic control models were formulated using optimization approach, with the objective functions of minimizing vehicle delay time. To improve people’s trip efficiency, this article aims to minimize delay time per person. Based on the time-varying traffic flow data at intersections, the article first fits curves of accumulative arrival and departure vehicles, as well as the corresponding functions. Moreover, this article transfers vehicle delay time to personal delay time using average passenger load of cars and buses, employs such time as the objective function, and proposes a signal timing optimization model for intersections to achieve real-time signal parameters, including cycle length and green time. This research further implements a case study based on practical data collected at an intersection in Beijing, China. The average delay time per person and queue length are employed as evaluation indices to show the performances of the model. The results show that the proposed methodology is capable of improving traffic efficiency and is very effective for real-world applications.

Patient Delay, Diagnosis Delay and Treatment Delay for Breast Cancer: Comparison of the Pattern between Patients in Public and Private Health Sectors

Directory of Open Access Journals (Sweden)

Iraj Harirchi

2015-05-01

Full Text Available Background: The purpose of this study was to compare patient delay, diagnosis delay and treatment delay in breast cancer patients of selected public and private health centers in Tehran, Iran.Methods: In this cross-sectional study, female patients with newly diagnosed breast cancer in a public medical complex and a private breast clinic within one year were included. Patient delay was considered positive, if the interval between the detection of the first symptom by the patient and the first visit to a health care provider took longer than one month. Delay in diagnosis was defined as the period of more than one week between the first medical visit for the symptoms and the diagnosis of breast cancer. Following the confirmed diagnosis of breast malignancy, if the medical treatment was initiated later than one week, treatment delay had occurred. The potential reasons for patient, diagnosis and treatment delay according to the patients’ reports were also recorded.Results: Overall, 385 patients were included of whom 52.7% were recruited from the public hospitals and 47.3% from a private clinic. The prevalence of patient delay, diagnosis delay and treatment delay were 31.7%, 17.9% and 28.3%, respectively. Patient delay was significantly more common among patients with lower socio-economic status and those recruited from the public hospitals. All the patients with diagnosis delay were in the group recruited from the public hospitals.Conclusions: Gaps between women of different socio-economic levels of the society need to be addressed in order to decrease patient, diagnosis and treatment delay.

Speech and Language Delay

Science.gov (United States)

... OTC Relief for Diarrhea Home Diseases and Conditions Speech and Language Delay Condition Speech and Language Delay Share Print Table of Contents1. ... Treatment6. Everyday Life7. Questions8. Resources What is a speech and language delay? A speech and language delay ...

Visual prediction: psychophysics and neurophysiology of compensation for time delays.

Science.gov (United States)

Nijhawan, Romi

2008-04-01

A necessary consequence of the nature of neural transmission systems is that as change in the physical state of a time-varying event takes place, delays produce error between the instantaneous registered state and the external state. Another source of delay is the transmission of internal motor commands to muscles and the inertia of the musculoskeletal system. How does the central nervous system compensate for these pervasive delays? Although it has been argued that delay compensation occurs late in the motor planning stages, even the earliest visual processes, such as phototransduction, contribute significantly to delays. I argue that compensation is not an exclusive property of the motor system, but rather, is a pervasive feature of the central nervous system (CNS) organization. Although the motor planning system may contain a highly flexible compensation mechanism, accounting not just for delays but also variability in delays (e.g., those resulting from variations in luminance contrast, internal body temperature, muscle fatigue, etc.), visual mechanisms also contribute to compensation. Previous suggestions of this notion of "visual prediction" led to a lively debate producing re-examination of previous arguments, new analyses, and review of the experiments presented here. Understanding visual prediction will inform our theories of sensory processes and visual perception, and will impact our notion of visual awareness.

A study on quantification of the information flow and effectiveness of information aids for diagnosis tasks in nuclear power plants

International Nuclear Information System (INIS)

Kim, Jong Hyun

2004-02-01

Diagnosis is one of the most complex and mental resource-demanding tasks in nuclear power plants (NPPs), especially, to main control room (MCR) operators. Diagnosis is a crucial part of disturbance control in NPPs, since it is a prerequisite task for initiating operating procedures. In order to design a control room feature for NPPs, three elements need to be considered: 1) the operational tasks that must be performed, 2) a model of human performance for these tasks, and 3) a model of how control room features are intended to support performance. The operational tasks define the classes of performance that must be considered. A model of human performance makes more explicit the requirements for accurate and efficient performance and reveals potential sources of error. Finally, the model of support allows the generation of specific hypotheses about how performance is facilitated in the control room. The model of support needs to be developed based on the human performance model. This paper proposes three approaches for the system design of operator support systems to aid MCR operators' diagnosis tasks in NPPs, considering the above three elements. This paper presents 1) a quantitative approach to modeling the information flow of diagnosis tasks, 2) strategy-based evaluation of information aids for diagnosis tasks, and 3) quantitative evaluation of NPP decision support systems. As an analysis of diagnosis tasks, this paper presents a method to quantify the cognitive information flow of diagnosis tasks, integrating a stage model (a qualitative approach) with information theory (a quantitative approach). The method includes: 1) constructing the information flow model, which consists of four stages based on operating procedures of NPPs: and 2) quantifying the information flow using Conant's model, a kind of information theory. Then, three experiments were conducted to evaluate the effectiveness of the proposed approach to predicting human performances, especially in

[Factors linked to delayed diagnosis of tuberculosis in Conakry (Guinea)].

Science.gov (United States)

Camara, A; Diallo, A; Camara, L M; Fielding, K; Sow, O Y; Chaperon, J

2006-03-01

Untreated smear-positive pulmonary tuberculosis constitutes a reservoir of infection which is highly contagious. The present study was conducted in Conakry, Guinea, to determine the different options which are available when seeking treatment or care, and to ascertain the average delay in diagnosis of pulmonary tuberculosis and the main factors linked to the delay in diagnosis after the initial onset of symptoms. Through a cross-sectional study, 113 consecutive patients with smear-positive pulmonary tuberculosis were interviewed through the use of a questionnaire. The median total delay from the onset of symptoms of pulmonary tuberculosis until the diagnosis was 11 weeks. This delay period exceeded 4 weeks for 90 of the patients (80%). The average delay linked to the conventional health care system was double that of the one at the fault of the patient (6 weeks versus 3 weeks, respectively). 54% of the patients had initially resorted to non-conventional care. To shorten this mean delay period, it is necessary to both strengthen the professional abilities and skills which train for one to better to detect tuberculosis and to sensitize the population to the subject matter and information on the illness and its symptoms.

Variable cycle control model for intersection based on multi-source information

Science.gov (United States)

Sun, Zhi-Yuan; Li, Yue; Qu, Wen-Cong; Chen, Yan-Yan

2018-05-01

In order to improve the efficiency of traffic control system in the era of big data, a new variable cycle control model based on multi-source information is presented for intersection in this paper. Firstly, with consideration of multi-source information, a unified framework based on cyber-physical system is proposed. Secondly, taking into account the variable length of cell, hysteresis phenomenon of traffic flow and the characteristics of lane group, a Lane group-based Cell Transmission Model is established to describe the physical properties of traffic flow under different traffic signal control schemes. Thirdly, the variable cycle control problem is abstracted into a bi-level programming model. The upper level model is put forward for cycle length optimization considering traffic capacity and delay. The lower level model is a dynamic signal control decision model based on fairness analysis. Then, a Hybrid Intelligent Optimization Algorithm is raised to solve the proposed model. Finally, a case study shows the efficiency and applicability of the proposed model and algorithm.

Collective Influence of Multiple Spreaders Evaluated by Tracing Real Information Flow in Large-Scale Social Networks.

Science.gov (United States)

Teng, Xian; Pei, Sen; Morone, Flaviano; Makse, Hernán A

2016-10-26

Identifying the most influential spreaders that maximize information flow is a central question in network theory. Recently, a scalable method called "Collective Influence (CI)" has been put forward through collective influence maximization. In contrast to heuristic methods evaluating nodes' significance separately, CI method inspects the collective influence of multiple spreaders. Despite that CI applies to the influence maximization problem in percolation model, it is still important to examine its efficacy in realistic information spreading. Here, we examine real-world information flow in various social and scientific platforms including American Physical Society, Facebook, Twitter and LiveJournal. Since empirical data cannot be directly mapped to ideal multi-source spreading, we leverage the behavioral patterns of users extracted from data to construct "virtual" information spreading processes. Our results demonstrate that the set of spreaders selected by CI can induce larger scale of information propagation. Moreover, local measures as the number of connections or citations are not necessarily the deterministic factors of nodes' importance in realistic information spreading. This result has significance for rankings scientists in scientific networks like the APS, where the commonly used number of citations can be a poor indicator of the collective influence of authors in the community.

Improving the security of optoelectronic delayed feedback system by parameter modulation and system coupling

Science.gov (United States)

Liu, Lingfeng; Miao, Suoxia; Cheng, Mengfan; Gao, Xiaojing

2016-02-01

A coupled system with varying parameters is proposed to improve the security of optoelectronic delayed feedback system. This system is coupled by two parameter-varied optoelectronic delayed feedback systems with chaotic modulation. Dynamics performance results show that this system has a higher complexity compared to the original one. Furthermore, this system can conceal the time delay effectively against the autocorrelation function and delayed mutual information method and can increase the dimension space of secure parameters to resist brute-force attack by introducing the digital chaotic systems.

Stroboscopic visual training improves information encoding in short-term memory.

Science.gov (United States)

Appelbaum, L Gregory; Cain, Matthew S; Schroeder, Julia E; Darling, Elise F; Mitroff, Stephen R

2012-11-01

The visual system has developed to transform an undifferentiated and continuous flow of information into discrete and manageable representations, and this ability rests primarily on the uninterrupted nature of the input. Here we explore the impact of altering how visual information is accumulated over time by assessing how intermittent vision influences memory retention. Previous work has shown that intermittent, or stroboscopic, visual training (i.e., practicing while only experiencing snapshots of vision) can enhance visual-motor control and visual cognition, yet many questions remain unanswered about the mechanisms that are altered. In the present study, we used a partial-report memory paradigm to assess the possible changes in visual memory following training under stroboscopic conditions. In Experiment 1, the memory task was completed before and immediately after a training phase, wherein participants engaged in physical activities (e.g., playing catch) while wearing either specialized stroboscopic eyewear or transparent control eyewear. In Experiment 2, an additional group of participants underwent the same stroboscopic protocol but were delayed 24 h between training and assessment, so as to measure retention. In comparison to the control group, both stroboscopic groups (immediate and delayed retest) revealed enhanced retention of information in short-term memory, leading to better recall at longer stimulus-to-cue delays (640-2,560 ms). These results demonstrate that training under stroboscopic conditions has the capacity to enhance some aspects of visual memory, that these faculties generalize beyond the specific tasks that were trained, and that trained improvements can be maintained for at least a day.

A work process and information flow description of control room operations

International Nuclear Information System (INIS)

Davey, E.; Matthews, G.

2007-01-01

The control room workplace is the location from which all plant operations are supervised and controlled on a shift-to-shift basis. The activities comprising plant operations are structured into a number of work processes, and information is the common currency that is used to convey work requirements, communicate business and operating decisions, specify work practice, and describe the ongoing plant and work status. This paper describes the motivation for and early experience with developing a work process and information flow model of CANDU control room operations, and discusses some of the insights developed from model examination that suggest ways in which changes in control centre work specification, organization of resources, or asset layout could be undertaken to achieve operational improvements. (author)

Synchronization of delayed systems in the presence of delay time modulation

International Nuclear Information System (INIS)

Kye, Won-Ho; Choi, Muhan; Kim, Myung-Woon; Lee, Soo-Young; Rim, Sunghwan; Kim, Chil-Min; Park, Young-Jai

2004-01-01

We investigate synchronization in the presence of delay time modulation for application to communication. We have observed that the robust synchronization is established by a common delay signal and its threshold is presented using Lyapunov exponents analysis. The influence of the delay time modulation in chaotic oscillators is also discussed

Experimental resource pulses influence social-network dynamics and the potential for information flow in tool-using crows.

Science.gov (United States)

St Clair, James J H; Burns, Zackory T; Bettaney, Elaine M; Morrissey, Michael B; Otis, Brian; Ryder, Thomas B; Fleischer, Robert C; James, Richard; Rutz, Christian

2015-11-03

Social-network dynamics have profound consequences for biological processes such as information flow, but are notoriously difficult to measure in the wild. We used novel transceiver technology to chart association patterns across 19 days in a wild population of the New Caledonian crow--a tool-using species that may socially learn, and culturally accumulate, tool-related information. To examine the causes and consequences of changing network topology, we manipulated the environmental availability of the crows' preferred tool-extracted prey, and simulated, in silico, the diffusion of information across field-recorded time-ordered networks. Here we show that network structure responds quickly to environmental change and that novel information can potentially spread rapidly within multi-family communities, especially when tool-use opportunities are plentiful. At the same time, we report surprisingly limited social contact between neighbouring crow communities. Such scale dependence in information-flow dynamics is likely to influence the evolution and maintenance of material cultures.

Integrated Traffic Flow Management Decision Making

Science.gov (United States)

Grabbe, Shon R.; Sridhar, Banavar; Mukherjee, Avijit

2009-01-01

A generalized approach is proposed to support integrated traffic flow management decision making studies at both the U.S. national and regional levels. It can consider tradeoffs between alternative optimization and heuristic based models, strategic versus tactical flight controls, and system versus fleet preferences. Preliminary testing was accomplished by implementing thirteen unique traffic flow management models, which included all of the key components of the system and conducting 85, six-hour fast-time simulation experiments. These experiments considered variations in the strategic planning look-ahead times, the replanning intervals, and the types of traffic flow management control strategies. Initial testing indicates that longer strategic planning look-ahead times and re-planning intervals result in steadily decreasing levels of sector congestion for a fixed delay level. This applies when accurate estimates of the air traffic demand, airport capacities and airspace capacities are available. In general, the distribution of the delays amongst the users was found to be most equitable when scheduling flights using a heuristic scheduling algorithm, such as ration-by-distance. On the other hand, equity was the worst when using scheduling algorithms that took into account the number of seats aboard each flight. Though the scheduling algorithms were effective at alleviating sector congestion, the tactical rerouting algorithm was the primary control for avoiding en route weather hazards. Finally, the modeled levels of sector congestion, the number of weather incursions, and the total system delays, were found to be in fair agreement with the values that were operationally observed on both good and bad weather days.

Bullwhip Effect in the Information Flow of a Supply Chain: A Role of Culture

Directory of Open Access Journals (Sweden)

Lampret Tadeja

2014-11-01

Full Text Available The main goal of our research is to analyze and display causes of a bullwhip effect formation within a supply chain, as well as to provide the appropriate solutions to limit the occurrence of the bullwhip effect by using the proper information flow and partners’ cooperation within the supply chain. The bullwhip effect is one of the most important issues in the supply chain management and it is present in many companies. It preserves a character of invisibility because there are lots of causes for its formation and they are usually difficult to discern. The bullwhip effect is a phenomenon of an increase in the order variability within a supply chain. The higher we are within the supply chain, the higher is the order variability. The company encountered with the whip effect can successfully reduce its impact by improving the information flow, as well as improving partners’ cooperation within the supply chain. In this way the company can limit its negative repercussions and increase the profit. The article focuses on the overview of the bullwhip effect within a distribution chain, from its causes to suggestions and measures how to ease its negative repercussions on the organisation. Part of the causes could be found in the market demand variability and in the lack of communication about the actual marked demand within the supply chain. The rest of the causes are related to obstacles that emerge among different partners within the supply chain (role of culture. A qualitative analysis is applied on the basis of the selected cognitions from the supply chain management. The quantitative analysis is based on the theoretical research of the effective flow of information among the participants and its contribution to the reduction of the bullwhip impact. The article discusses two research questions: 1 The correct information flow within the supply chain and the improvement of the communication among partners can lead to the bullwhip effect reduction

Simulation of wing-body junction flows with hybrid RANS/LES methods

International Nuclear Information System (INIS)

Fu Song; Xiao Zhixiang; Chen Haixin; Zhang Yufei; Huang Jingbo

2007-01-01

In this paper, flows past two wing-body junctions, the Rood at zero angle of attack and NASA TN D-712 at 12.5 o angle of attack, are investigated with two Reynolds-Averaged Navier-Stokes (RANS) and large eddy simulation (LES) hybrid methods. One is detached eddy simulation (DES) and the other is delayed-DES, both are based on a weakly nonlinear two-equation k-ω model. While the RANS method can predict the mean flow behaviours reasonably accurately, its performance for the turbulent kinetic energy and shear stress, as compared with available experimental data, is not satisfactory. DES, through introducing a length scale in the dissipation terms of the turbulent kinetic energy equation, delivers flow separation, a vortex or the onset of vortex breakdown too early. DDES, with its delayed effect, shows a great improvement in flow structures and turbulence characteristics, and agrees well with measurements

Plasma flow discharge researches at the PIRIT-2000 facility

International Nuclear Information System (INIS)

Popkov, N.F.; Ryaslov, E.A.; Kargin, V.I.; Pikar', A.S.; Vorontsov, V.I.; Kotel'nikov, D.V.; Melkozerov, A.V.

1996-01-01

Investigation of a plasma flow switch at the PIRIT-2000 fast operating capacitor bank is reported. The maximum current of the plasma flow discharge (PFD) reaches 5 MA, the current rise time being as low as 100 ns. The magnetic field strength of the plasma flow switch (0.15 T) is about 15 times higher than that of the plasma erosion switch used earlier. Both magnetic probe and optical methods were used in the experiments. From the magnetic probes data the propagating velocity of a current carrying shell (205 cm/s) has been derived, while the optical method is used for determining the velocity of a glowing plasma layer. At varying the operation delay in the range 2-10 s the PFD load current rise time increases up to 150-200 ns, the prepulse increment reaching its maximum at the delays higher than 6 s. (J.U.). 5 figs., 5 refs

Plasma flow discharge researches at the PIRIT-2000 facility

Energy Technology Data Exchange (ETDEWEB)

Popkov, N F; Ryaslov, E A; Kargin, V I; Pikar` , A S; Vorontsov, V I; Kotel` nikov, D V; Melkozerov, A V [All-Russian Scientific Research Inst. of Experimental Physics, Sarov (Russian Federation)

1997-12-31

Investigation of a plasma flow switch at the PIRIT-2000 fast operating capacitor bank is reported. The maximum current of the plasma flow discharge (PFD) reaches 5 MA, the current rise time being as low as 100 ns. The magnetic field strength of the plasma flow switch (0.15 T) is about 15 times higher than that of the plasma erosion switch used earlier. Both magnetic probe and optical methods were used in the experiments. From the magnetic probes data the propagating velocity of a current carrying shell (205 cm/s) has been derived, while the optical method is used for determining the velocity of a glowing plasma layer. At varying the operation delay in the range 2-10 s the PFD load current rise time increases up to 150-200 ns, the prepulse increment reaching its maximum at the delays higher than 6 s. (J.U.). 5 figs., 5 refs.

Granger causality estimate of information flow in temperature fields is consistent with wind direction

Czech Academy of Sciences Publication Activity Database

Jajcay, Nikola; Hlinka, Jaroslav; Hartman, David; Paluš, Milan

2014-01-01

Roč. 16, - (2014), EGU2014-12768 ISSN 1607-7962. [EGU General Assembly /11./. 27.04.2014-02.05.2014, Vienna] Institutional support: RVO:67985807 Keywords : Granger causality * climate * information flow * surface air temperature * wind Subject RIV: BB - Applied Statistics, Operational Research

Determination of Uncalibrated Phase Delays for Real-Time PPP

Science.gov (United States)

Hinterberger, Fabian; Weber, Robert; Huber, Katrin; Lesjak, Roman

2014-05-01

Today PPP is a well-known technique of GNSS based positioning used for a wide range of post-processing applications. Using observations of a single GNSS receiver and applying precise orbit and clock information derived from global GNSS networks highly precise positions can be obtained. The atmospheric delays are usually mitigated by linear combination (ionosphere) and parameter estimation (troposphere). Within the last years also the demand for real-time PPP increased. In 2012, the IGS real-time working group started a pilot project to broadcast real-time precise orbits and clock correction streams. Nevertheless, real-time PPP is in its starting phase and currently only few applications make use of the technique although SSR-Messages are already implemented in RTCM3.1. The problems of still limited accuracy compared to Network-RTK as well as long convergence times might be solved by almost instantaneous integer ambiguity resolution at zero-difference level which is a major topic of current scientific investigations. Therefore a national consortium has carried out over the past 2 years the research project PPP-Serve (funded by the Austrian Research Promotion Agency - FFG), which aimed at the development of appropriate algorithms for real-time PPP with special emphasis on the ambiguity resolution of zero-difference observations. We have established a module which calculates based on GPS-reference station data-streams of a dense network (obtained from IGS via BKG) so-called wide-lane and narrow-lane satellite specific calibration phase delays. While the wide-lane phase delays are almost stable over longer periods, the estimation of narrow-lane phase delays has to be re-established every 24 hours. These phase-delays are submitted via a real-time module to the rover where they are used for point positioning via a PPP-model. This presentation deals with the process and obstacles of calculating the wide-lane and narrow-lane phase-delays (based on SD -observations between

Modelling Compensation Policy for Quality and Delay Deterioration in Rail Transport

Directory of Open Access Journals (Sweden)

Tatiana Molkova

2013-06-01

Full Text Available The contribution deals with the customers’ claims on provided services during train delay in personal railway transport. There is comparison between the situation in the Czech Republic (Brno main station and Austria (Wien Westbahnhof in the contribution. Development of the compensation policy cannot be based only on customer requirements. If the railway company focuses on providing compensation for delays, it must follow its economic balance. However, as the passengers' opinion survey showed, the negative impact of delays can be reduced by providing adequate information to passengers. Based on the passengers' opinion survey, it is necessary to consider the Regulation 1371/2007/ES as the minimum of the possible and on the basis of this reasoning to compile a compensation policy. The costs associated with compensation for the delay should be divided according to the causes of the delay among the individual culprits, so that railway undertakings bear the responsibility even for delays arising from reasons that are beyond the control of the railway undertaking itself. 

Chaos synchronization in time-delayed systems with parameter mismatches and variable delay times

International Nuclear Information System (INIS)

Shahverdiev, E.M.; Nuriev, R.A.; Hashimov, R.H.; Shore, K.A.

2004-06-01

We investigate synchronization between two undirectionally linearly coupled chaotic nonidentical time-delayed systems and show that parameter mismatches are of crucial importance to achieve synchronization. We establish that independent of the relation between the delay time in the coupled systems and the coupling delay time, only retarded synchronization with the coupling delay time is obtained. We show that with parameter mismatch or without it neither complete nor anticipating synchronization occurs. We derive existence and stability conditions for the retarded synchronization manifold. We demonstrate our approach using examples of the Ikeda and Mackey Glass models. Also for the first time we investigate chaos synchronization in time-delayed systems with variable delay time and find both existence and sufficient stability conditions for the retarded synchronization manifold with the coupling-delay lag time. (author)

Bearing fault detection utilizing group delay and the Hilbert-Huang transform

International Nuclear Information System (INIS)

Jin, Shuai; Lee, Sang-Kwon

2017-01-01

Vibration signals measured from a mechanical system are useful to detect system faults. Signal processing has been used to extract fault information in bearing systems. However, a wide vibration signal frequency band often affects the ability to obtain the effective fault features. In addition, a few oscillation components are not useful at the entire frequency band in a vibration signal. By contrast, useful fatigue information can be embedded in the noise oscillation components. Thus, a method to estimate which frequency band contains fault information utilizing group delay was proposed in this paper. Group delay as a measure of phase distortion can indicate the phase structure relationship in the frequency domain between original (with noise) and denoising signals. We used the empirical mode decomposition of a Hilbert-Huang transform to sift the useful intrinsic mode functions based on the results of group delay after determining the valuable frequency band. Finally, envelope analysis and the energy distribution after the Hilbert transform were used to complete the fault diagnosis. The practical bearing fault data, which were divided into inner and outer race faults, were used to verify the efficiency and quality of the proposed method

Bearing fault detection utilizing group delay and the Hilbert-Huang transform

Energy Technology Data Exchange (ETDEWEB)

Jin, Shuai; Lee, Sang-Kwon [Inha University, Incheon (Korea, Republic of)

2017-03-15

Vibration signals measured from a mechanical system are useful to detect system faults. Signal processing has been used to extract fault information in bearing systems. However, a wide vibration signal frequency band often affects the ability to obtain the effective fault features. In addition, a few oscillation components are not useful at the entire frequency band in a vibration signal. By contrast, useful fatigue information can be embedded in the noise oscillation components. Thus, a method to estimate which frequency band contains fault information utilizing group delay was proposed in this paper. Group delay as a measure of phase distortion can indicate the phase structure relationship in the frequency domain between original (with noise) and denoising signals. We used the empirical mode decomposition of a Hilbert-Huang transform to sift the useful intrinsic mode functions based on the results of group delay after determining the valuable frequency band. Finally, envelope analysis and the energy distribution after the Hilbert transform were used to complete the fault diagnosis. The practical bearing fault data, which were divided into inner and outer race faults, were used to verify the efficiency and quality of the proposed method.

First-Case Operating Room Delays: Patterns Across Urban Hospitals of a Single Health Care System

Directory of Open Access Journals (Sweden)

Callie M. Cox Bauer

2016-08-01

Full Text Available Purpose: Operating room delays decrease health care system efficiency and increase costs. To improve operating room efficiency in our system, we retrospectively investigated delay frequencies, causes and costs. Methods: We studied all first-of-the-day nonemergent surgical cases performed at three high-volume urban hospitals of a large health system from July 2012 to November 2013. Times for patient flow from arrival to procedure start and documented reasons for delay were obtained from electronic medical records. Delay was defined as patient placement in the operating room later than scheduled surgery time. Effects of patient characteristics, late patient arrival to the hospital, number of planned procedures, years of surgeon experience, service department and hospital facility on odds of delay were examined using logistic regression. Results: Of 5,598 cases examined, 88% were delayed. Patients arrived late to the hospital (surgery in 65% of first cases. Mean time from arrival to scheduled surgery and in-room placement was 104.6 and 127.4 minutes, respectively. Mean delay time was 28.2 minutes. Nearly 60% of delayed cases had no documented reason for delay. For cases with documentation, causes included the physician (52%, anesthesia (15%, patient (13%, staff (9%, other sources (6% and facility (5%. Regression analysis revealed age, late arrival, department and facility as significant predictors of delay. Estimated delay costs, based on published figures and representing lost revenue, were $519,388. Conclusions: To improve operating room efficiency, multidisciplinary strategies are needed for increasing patient adherence to recommended arrival times, documentation of delay by medical staff and consistency in workflow patterns among facilities and departments.

Is central dogma a global property of cellular information flow?

Science.gov (United States)

Piras, Vincent; Tomita, Masaru; Selvarajoo, Kumar

2012-01-01

The central dogma of molecular biology has come under scrutiny in recent years. Here, we reviewed high-throughput mRNA and protein expression data of Escherichia coli, Saccharomyces cerevisiae, and several mammalian cells. At both single cell and population scales, the statistical comparisons between the entire transcriptomes and proteomes show clear correlation structures. In contrast, the pair-wise correlations of single transcripts to proteins show nullity. These data suggest that the organizing structure guiding cellular processes is observed at omics-wide scale, and not at single molecule level. The central dogma, thus, globally emerges as an average integrated flow of cellular information.

Complex-Vector Time-Delay Control of Power Converters

DEFF Research Database (Denmark)

Blaabjerg, Frede; Loh, P. C.; Tang, Y.

2008-01-01

Precise controlling of current produced by power converters is an important topic that has attracted interests over the last few decades. With the recent proliferation of grid-tied converters where the control of power flow is indirectly governed by the accuracy of current tracking, motivation...... since only a small amount of memory space for storing time-delayed values and simple arithmetic computations are needed for its physical realization. In addition to that, other advantages of the scheme include its abilities to compensate for negative-sequence, load and grid harmonic components using...

Spectra and pseudospectra of neutral delay differential equations with application to real-time substructuring

NARCIS (Netherlands)

Green, K.; Wagenknecht, T.

2010-01-01

This paper deals with the computation of pseudospectra of neutral delay differential equations (NDDEs) with fixed finite delays. This method provides information on the sensitivity of eigenvalues of the system under perturbations of a given size, allowing one to analyse uncertainties in, for

Optimal control for parabolic-hyperbolic system with time delay

International Nuclear Information System (INIS)

Kowalewski, A.

1985-07-01

In this paper we consider an optimal control problem for a system described by a linear partial differential equation of the parabolic-hyperbolic type with time delay in the state. The right-hand side of this equation and the initial conditions are not continuous functions usually, but they are measurable functions belonging to L 2 or Lsup(infinity) spaces. Therefore, the solution of this equation is given by a certain Sobolev space. The time delay in the state is constant, but it can be also a function of time. The control time T is fixed in our problem. Making use of the Milutin-Dubovicki theorem, necessary and sufficient conditions of optimality with the quadratic performance functional and constrained control are derived for the Dirichlet problem. The flow chart of the algorithm which can be used in the numerical solving of certain optimization problems for distributed systems is also presented. (author)

Managing Returnable Containers Logistics - A Case Study Part I - Physical and Information Flow Analysis

Directory of Open Access Journals (Sweden)

Reza A. Maleki

2011-05-01

Full Text Available This case study paper is the result of a project conducted on behalf of a company, hereon referred to as Midwest Assembly and Manufacturing or MAAN. The company's operations include component manufacturing, painting, and assembling products. The company also purchases a relatively large percentage of components and major assemblies that are needed to support final assembly operations. MAAN uses its own returnable containers to transport purchased parts from suppliers. Due to poor tracking of the containers, the company has been experiencing lost containers and occasional production disruptions at its facility well as at the supplier sites. The objective of this project was to develop a proposal to enable MAAN to more effectively track and manage its returnable containers. The research activities in support of this project included the analysis and documentation of both the physical flow and the information flow associated with the containers as well as some of the technologies that can help with automatic identification and tracking of containers. The focal point of this paper is on a macro?level approach for the analysis of container and information flow within the logistics chain. A companion paper deals with several of the automatic identification technologies that have the potential to improve the management of MAAN's returnable containers.

Real Options in Capital Budgeting. Pricing the Option to Delay and the Option to Abandon a Project

Directory of Open Access Journals (Sweden)

Nicoleta Vintila

2007-07-01

Full Text Available Traditional discounted cash-flows method for assessing projects assumes that investment decision is an irreversible one, which is not correct. Managers can and must reconsider their initial decision as the new information arises during the project life. This is managerial flexibility and it creates strategic value for a project, only if management takes advantage of the opportunities associated with an analyzed project. Real options represent a new approach in capital budgeting, using the theory of pricing financial options for investments in real assets. In this paper, we emphasize the characteristics and valuation methodologies of real options. The objective in the last section is pricing the option to delay and the option to abandon a project in construction materials field.

Construction schedule delay risk assessment by using combined AHP-RII methodology for an international NPP project

Directory of Open Access Journals (Sweden)

Muhammed Mufazzal Hossen

2015-04-01

The proposed combined AHP-RII methodology is capable of assessing delay risk effectively and efficiently. Decision makers can apply risk informed decision making to avoid unexpected construction delays of NPPs.

Humans Optimize Decision-Making by Delaying Decision Onset

Science.gov (United States)

Teichert, Tobias; Ferrera, Vincent P.; Grinband, Jack

2014-01-01

Why do humans make errors on seemingly trivial perceptual decisions? It has been shown that such errors occur in part because the decision process (evidence accumulation) is initiated before selective attention has isolated the relevant sensory information from salient distractors. Nevertheless, it is typically assumed that subjects increase accuracy by prolonging the decision process rather than delaying decision onset. To date it has not been tested whether humans can strategically delay decision onset to increase response accuracy. To address this question we measured the time course of selective attention in a motion interference task using a novel variant of the response signal paradigm. Based on these measurements we estimated time-dependent drift rate and showed that subjects should in principle be able trade speed for accuracy very effectively by delaying decision onset. Using the time-dependent estimate of drift rate we show that subjects indeed delay decision onset in addition to raising response threshold when asked to stress accuracy over speed in a free reaction version of the same motion-interference task. These findings show that decision onset is a critical aspect of the decision process that can be adjusted to effectively improve decision accuracy. PMID:24599295

Adaptation to delayed force perturbations in reaching movements.

Directory of Open Access Journals (Sweden)

Noa Levy

Full Text Available Adaptation to deterministic force perturbations during reaching movements was extensively studied in the last few decades. Here, we use this methodology to explore the ability of the brain to adapt to a delayed velocity-dependent force field. Two groups of subjects preformed a standard reaching experiment under a velocity dependent force field. The force was either immediately proportional to the current velocity (Control or lagged it by 50 ms (Test. The results demonstrate clear adaptation to the delayed force perturbations. Deviations from a straight line during catch trials were shifted in time compared to post-adaptation to a non-delayed velocity dependent field (Control, indicating expectation to the delayed force field. Adaptation to force fields is considered to be a process in which the motor system predicts the forces to be expected based on the state that a limb will assume in response to motor commands. This study demonstrates for the first time that the temporal window of this prediction needs not to be fixed. This is relevant to the ability of the adaptive mechanisms to compensate for variability in the transmission of information across the sensory-motor system.

Classic conditioning in aged rabbits: delay, trace, and long-delay conditioning.

Science.gov (United States)

Solomon, P R; Groccia-Ellison, M E

1996-06-01

Young (0.5 years) and aged (2+, 3+, and 4+ years) rabbits underwent acquisition of the classically conditioned nictitating membrane response in a delay (500-ms conditioned stimulus [CS], 400-ms interstimulus interval [ISI]), long-delay (1,000-ms CS, 900-ms ISI), or trace (500-ms CS, 400-ms stimulus-free period) paradigm. Collapsing across age groups, there is a general tendency for animals to acquire trace conditioning more slowly than delay conditioning. Collapsing across conditioning paradigms, there is a general tendency for aged animals to acquire more slowly than younger animals. Of greater significance, however, are the age differences in the different conditioning paradigms. In the delay and long-delay paradigms, significant conditioning deficits first appeared in the 4(+)-year-old group. In the trace conditioning paradigm, significant conditioning deficits became apparent in the 2(+)-year-old animals.

Vertex centrality as a measure of information flow in Italian Corporate Board Networks

Science.gov (United States)

Grassi, Rosanna

2010-06-01

The aim of this article is to investigate the governance models of companies listed on the Italian Stock Exchange by using a network approach, which describes the interlinks between boards of directors. Following mainstream literature, I construct a weighted graph representing the listed companies (vertices) and their relationships (weighted edges), the Corporate Board Network; I then apply three different vertex centrality measures: degree, betweenness and flow betweenness. What emerges from the network construction and by applying the degree centrality is a structure with a large number of connections but not particularly dense, where the presence of a small number of highly connected nodes (hubs) is evident. Then I focus on betweenness and flow betweenness; indeed I expect that these centrality measures may give a representation of the intensity of the relationship between companies, capturing the volume of information flowing from one vertex to another. Finally, I investigate the possible scale-free structure of the network.

Decoding complex flow-field patterns in visual working memory.

Science.gov (United States)

Christophel, Thomas B; Haynes, John-Dylan

2014-05-01

There has been a long history of research on visual working memory. Whereas early studies have focused on the role of lateral prefrontal cortex in the storage of sensory information, this has been challenged by research in humans that has directly assessed the encoding of perceptual contents, pointing towards a role of visual and parietal regions during storage. In a previous study we used pattern classification to investigate the storage of complex visual color patterns across delay periods. This revealed coding of such contents in early visual and parietal brain regions. Here we aim to investigate whether the involvement of visual and parietal cortex is also observable for other types of complex, visuo-spatial pattern stimuli. Specifically, we used a combination of fMRI and multivariate classification to investigate the retention of complex flow-field stimuli defined by the spatial patterning of motion trajectories of random dots. Subjects were trained to memorize the precise spatial layout of these stimuli and to retain this information during an extended delay. We used a multivariate decoding approach to identify brain regions where spatial patterns of activity encoded the memorized stimuli. Content-specific memory signals were observable in motion sensitive visual area MT+ and in posterior parietal cortex that might encode spatial information in a modality independent manner. Interestingly, we also found information about the memorized visual stimulus in somatosensory cortex, suggesting a potential crossmodal contribution to memory. Our findings thus indicate that working memory storage of visual percepts might be distributed across unimodal, multimodal and even crossmodal brain regions. Copyright © 2014 Elsevier Inc. All rights reserved.

Attosecond delay in the molecular photoionization of asymmetric molecules.

Science.gov (United States)

Chacón, Alexis; Ruiz, Camilo

2018-02-19

We report theoretical calculations of the delay in photoemission from CO with particular emphasis on the role of the ultrafast electronic bound dynamics. We study the delays in photoionization in the HOMO and HOMO-1 orbitals of the CO molecule by looking into the stereo Wigner time delay technique. That compares the delay in photoemission from electrons emitted to the left and right to extract structural and dynamical information of the ionization process. For this we apply two techniques: The attosecond streak camera and the time of flight technique. Although they should provide the same results we have found large discrepancies of up to 36 in the case of HOMO, while for the HOMO-1 we obtain the same results with the two techniques. We have found that the large time delays observed in the HOMO orbital with the streaking technique are a consequence of the resonant transition triggered by the streaking field. This resonant transition produces a bound electron wavepacket that modifies the measurements of delay in photoionization. As a result of this observation, our technique allows us to reconstruct the bound wavepacket dynamics induced by the streaking field. By measuring the expected value of the electron momentum along the polarization direction after the streaking field has finished, we can recover the relative phase between the complex amplitudes of the HOMO and LUMO orbitals. These theoretical calculations pave the way for the measurement of ultrafast bound-bound electron transitionsand its crucial role for the delay in photoemission observation.

Regenerative memory in time-delayed neuromorphic photonic resonators

Science.gov (United States)

Romeira, B.; Avó, R.; Figueiredo, José M. L.; Barland, S.; Javaloyes, J.

2016-01-01

We investigate a photonic regenerative memory based upon a neuromorphic oscillator with a delayed self-feedback (autaptic) connection. We disclose the existence of a unique temporal response characteristic of localized structures enabling an ideal support for bits in an optical buffer memory for storage and reshaping of data information. We link our experimental implementation, based upon a nanoscale nonlinear resonant tunneling diode driving a laser, to the paradigm of neuronal activity, the FitzHugh-Nagumo model with delayed feedback. This proof-of-concept photonic regenerative memory might constitute a building block for a new class of neuron-inspired photonic memories that can handle high bit-rate optical signals.

Factors influencing delay in the diagnosis of colorectal cancer: a study protocol

International Nuclear Information System (INIS)

Esteva, Magdalena; Ramos, Maria; Cabeza, Elena; Llobera, Joan; Ruiz, Amador; Pita, Salvador; Segura, Josep M; Cortés, Jose M; González-Lujan, Luis

2007-01-01

Colorectal cancer (CRC) is the second most frequent tumor in developed countries. Since survival from CRC depends mostly on disease stage at the time of diagnosis, individuals with symptoms or signs suspicious of CRC should be examined without delay. Many factors, however, intervene between symptom onset and diagnosis. This study was designed to: 1) Describe the diagnostic process of CRC from the onset of first symptoms to diagnosis and treatment. 2) Establish the time interval from initial symptoms to diagnosis and treatment, globally and considering patient's and doctors' delay, with the latter due to family physician and/or hospital services. 3) Identify the factors related to defined types of delay. 4) Assess the concordance between information included in primary health care and hospital clinical records regarding onset of first symptoms. Descriptive study, coordinated, with 5 participant groups of 5 different Spanish regions (Balearic Islands, Galicia, Catalunya, Aragón and Valencia Health Districts), with a total of 8 acute public hospitals and 140 primary care centers. Incident cases of CRC during the study period, as identified from pathology services at the involved hospitals. A sample size of 896 subjects has been estimated, 150 subjects for each participant group. Information will be collected through patient interviews and primary health care and hospital clinical records. Patient variables will include sociodemographic variables, family history of cancer, symptom perception, and confidence in the family physician; tumor variables will include tumor site, histological type, grade and stage; symptom variables will include date of onset, type and number of symptoms; health system variables will include number of patient contacts with family physician, type and content of the referral, hospital services attending the patient, diagnostic modalities and results; and delay intervals, including global delays and delays attributed to the patient

Influence of the heart rate and atrioventricular delays on vortex evolution and blood transport inside the left ventricle

Science.gov (United States)

Hendabadi, Sahar; Martinez-Legazpi, Pablo; Benito, Yolanda; Bermejo, Javier; Del Alamo, Juan Carlos; Shadden, Shawn

2013-11-01

Cardiac resynchronization therapy (CRT) is used to help restore coordinated pumping of the ventricles by overcoming delays in electrical conduction due to cardiac disease. This is accomplished by a specialized cardiac pacemaker that is able to adjust the atrioventricular (AV) delay.A major clinical challenge is to adjust the pacing strategy to best coordinate the blood flow mechanics of ventricular filling and ejection. To this end, we have studied the difference in the vortex formation and its evolution inside the left ventricle (LV) for 4 different AV delays in a cohort of patients with implanted pacemakers. A reconstruction algorithm was used to obtain 2D velocity over the apical long-axis view of the LV from color Doppler and B-mode ultrasound data. To study blood transport, we have identified Lagrangian coherent structures to determine moving boundaries of the blood volumes injected to the LV in diastole and ejected to the aorta in systole. In all cases, we have analyzed the differences in filling and ejection patterns and the blood transport during the E-wave and A-wave formation.Finally we have assessed the influence of the AV delay on 2 indices of stasis, direct flow and residence time.The findings shed insight to the optimization of AV delays in patients undergoing CRT. NIH award 5R21HL108268 and grants PIS09/02603 and RD06/0010 from the Plan Nacional de Investigacion Cientifica, Spain.

Collective Influence of Multiple Spreaders Evaluated by Tracing Real Information Flow in Large-Scale Social Networks

Science.gov (United States)

Teng, Xian; Pei, Sen; Morone, Flaviano; Makse, Hernán A.

2016-01-01

Identifying the most influential spreaders that maximize information flow is a central question in network theory. Recently, a scalable method called “Collective Influence (CI)” has been put forward through collective influence maximization. In contrast to heuristic methods evaluating nodes’ significance separately, CI method inspects the collective influence of multiple spreaders. Despite that CI applies to the influence maximization problem in percolation model, it is still important to examine its efficacy in realistic information spreading. Here, we examine real-world information flow in various social and scientific platforms including American Physical Society, Facebook, Twitter and LiveJournal. Since empirical data cannot be directly mapped to ideal multi-source spreading, we leverage the behavioral patterns of users extracted from data to construct “virtual” information spreading processes. Our results demonstrate that the set of spreaders selected by CI can induce larger scale of information propagation. Moreover, local measures as the number of connections or citations are not necessarily the deterministic factors of nodes’ importance in realistic information spreading. This result has significance for rankings scientists in scientific networks like the APS, where the commonly used number of citations can be a poor indicator of the collective influence of authors in the community. PMID:27782207

Global synchronization criteria with channel time-delay for chaotic time-delay system

International Nuclear Information System (INIS)

Sun Jitao

2004-01-01

Based on the Lyapunov stabilization theory, matrix measure, and linear matrix inequality (LMIs), this paper studies the chaos synchronization of time-delay system using the unidirectional linear error feedback coupling with time-delay. Some generic conditions of chaos synchronization with time-delay in the transmission channel is established. The chaotic Chua's circuit is used for illustration, where the coupling parameters are determined according to the criteria under which the global chaos synchronization of the time-delay coupled systems is achieved

Stability switches, oscillatory multistability, and spatio-temporal patterns of nonlinear oscillations in recurrently delay coupled neural networks.

Science.gov (United States)

Song, Yongli; Makarov, Valeri A; Velarde, Manuel G

2009-08-01

A model of time-delay recurrently coupled spatially segregated neural assemblies is here proposed. We show that it operates like some of the hierarchical architectures of the brain. Each assembly is a neural network with no delay in the local couplings between the units. The delay appears in the long range feedforward and feedback inter-assemblies communications. Bifurcation analysis of a simple four-units system in the autonomous case shows the richness of the dynamical behaviors in a biophysically plausible parameter region. We find oscillatory multistability, hysteresis, and stability switches of the rest state provoked by the time delay. Then we investigate the spatio-temporal patterns of bifurcating periodic solutions by using the symmetric local Hopf bifurcation theory of delay differential equations and derive the equation describing the flow on the center manifold that enables us determining the direction of Hopf bifurcations and stability of the bifurcating periodic orbits. We also discuss computational properties of the system due to the delay when an external drive of the network mimicks external sensory input.

Emergency surgery pre-operative delays - realities and economic impacts.

Science.gov (United States)

O'Leary, D P; Beecher, S; McLaughlin, R

2014-12-01

A key principle of acute surgical service provision is the establishment of a distinct patient flow process and an emergency theatre. Time-to-theatre (TTT) is a key performance indicator of theatre efficiency. The combined impacts of an aging population, increasing demands and complexity associated with centralisation of emergency and oncology services has placed pressure on emergency theatre access. We examined our institution's experience with running a designated emergency theatre for acute surgical patients. A retrospective review of an electronic prospectively maintained database was performed between 1/1/12 and 31/12/13. A cost analysis was conducted to assess the economic impact of delayed TTT, with every 24hr delay incurring the cost of an additional overnight bed. Delays and the economic effects were assessed only after the first 24 h as an in-patient had elapsed. In total, 7041 procedures were performed. Overall mean TTT was 26 h, 2 min. There were significant differences between different age groups, with those aged under 16 year and over 65 having mean TTT at 6 h, 34 min (95% C.I. 0.51-2.15, p 65 years age group had a mean TTT of 23 h, 41 min which was significantly longer than the overall mean TTT Vascular and urological emergencies are significantly disadvantaged in competition with other services for a shared emergency theatre. The economic impact of delayed TTT was calculated at €7,116,000, or €9880/day of additional costs generated from delayed TTT over a 24 month period. One third of patients waited longer than 24 h for emergency surgery, with the elderly disproportionately represented in this group. Aside from the clinical risks of delayed and out of hours surgery, such practices incur significant additional costs. New strategies must be devised to ensure efficient access to emergency theatres, investment in such services is likely to be financially and clinically beneficial. Copyright © 2014 Surgical Associates Ltd. Published by Elsevier

Delayed minocycline but not delayed mild hypothermia protects against embolic stroke

Directory of Open Access Journals (Sweden)

Noor Raza

2002-04-01

Full Text Available Abstract Background Inflammatory reactions occurring in the brain after ischemia may contribute to secondary damage. In the present study, effects of minocycline, an anti-inflammatory agent, alone or in combination with mild hypothermia on focal embolic cerebral ischemia have been examined. Methods Focal ischemic injury was induced by embolizing a preformed clot into the middle cerebral artery (MCA. Infarction volume was measured at 48 h after the injury. Mortality was also recorded. Results Delayed administration of minocycline alone or delayed minocycline plus delayed mild hypothermia reduced the infarction volume significantly. However, delayed mild hypothermia alone was not protective and delayed mild hypothermia in combination with minocycline did not show any additive effect. Conclusions These results suggest that minocycline is beneficial in focal ischemic brain injury, and the lack of the enhanced neuroprotection may be due to the brief exposure to hypothermia.

Owner and Contractor Perceptions Toward Factors Causing Delays in Structural and Finishing Works

Directory of Open Access Journals (Sweden)

Loanata V.R.

2010-01-01

Full Text Available A construction project comprises of a number of work packages, which are subjected to delays. These delays may be caused by many on-site factors. The aim of this research is to represent owner and contractors perceptions towards delay factors that frequently occur in structural and finishing works. Data for analysis were gathered by distributing questionnaire. A total of 198 sets of questionnaire were gathered and used for subsequent analyses. In general, design changes during construction are perceived by respondents as the most frequent factor to cause delay in all structural and finishing works. The results also show that there are a number of differences between owner’s and contractor’s perceptions towards the occurrences of the factors. Whilst most contractors concern that information factors related to project design and scope frequently causing delays in construction works, owners consider many contractor originated factors, as most frequent delay causes.

A method for identifying gas-liquid two-phase flow patterns on the basis of wavelet packet multi-scale information entropy and HMM

International Nuclear Information System (INIS)

Zhou Yunlong; Zhang Xueqing; Gao Yunpeng; Cheng Yue

2009-01-01

For studying flow regimes of gas/liquid two-phase in a vertical upward pipe, the conductance fluctuation information of four typical flow regimes was collected by a measuring the system with self-made multiple conductivity probes. Owing to the non-stationarity of conductance fluctuation signals of gas-liquid two-phase flow, a kind of' flow regime identification method based on wavelet packet Multi-scale Information Entropy and Hidden Markov Model (HMM) was put forward. First of all, the collected conductance fluctuation signals were decomposed into eight different frequency bands signals. Secondly, the wavelet packet multi-scale information entropy of different frequency bands signals were regarded as the input characteristic vectors of all states HMM which had been trained. In the end the regime identification of' the gas-liquid two-phase flow could be performed. The study showed that the method that HMM was applied to identify the flow regime was superior to the one that BP neural network was used, and the results proved that the method was efficient and feasible. (authors)

Delayed puberty in girls

Science.gov (United States)

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

Visual search guidance is best after a short delay.

Science.gov (United States)

Schmidt, Joseph; Zelinsky, Gregory J

2011-03-25

Search displays are typically presented immediately after a target cue, but in the real-world, delays often exist between target designation and search. Experiments 1 and 2 asked how search guidance changes with delay. Targets were cued using a picture or text label, each for 3000ms, followed by a delay up to 9000ms before the search display. Search stimuli were realistic objects, and guidance was quantified using multiple eye movement measures. Text-based cues showed a non-significant trend towards greater guidance following any delay relative to a no-delay condition. However, guidance from a pictorial cue increased sharply 300-600ms after preview offset. Experiment 3 replicated this guidance enhancement using shorter preview durations while equating the time from cue onset to search onset, demonstrating that the guidance benefit is linked to preview offset rather than a more complete encoding of the target. Experiment 4 showed that enhanced guidance persists even with a mask flashed at preview offset, suggesting an explanation other than visual priming. We interpret our findings as evidence for the rapid consolidation of target information into a guiding representation, which attains its maximum effectiveness shortly after preview offset. Copyright © 2011 Elsevier Ltd. All rights reserved.

Delayed Puberty (For Teens)

Science.gov (United States)

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

Disclosure of price-sensitive information

DEFF Research Database (Denmark)

Schaumburg-Müller, Peer; Werlauff, Erik

2013-01-01

to handle the Daimler judgment’s consequences with regard to “intermediate steps” in practical terms. In light of the Court’s relatively restrictive interpretation, a listed company in a similar situation really only has three options: (1) Delay: The company can delay disclosure of the inside information...... “on its own responsibility” in order not to damage the company’s legitimate interests – cf. on this Article 6(2) of Directive 2003/6/EC, which provides that “An issuer may, on his own responsibility, delay the public disclosure of inside information … so as not to prejudice his legitimate interests......, provided that such omission would not be likely to mislead the public…” It is a condition for delaying disclosure that doing so will not mislead the public, and the issuer can ensure that the information remains confidential. Member states can, but are not required to, demand (and so far Denmark for one...

Fast calculation of microphone array steering vectors with shear flow

NARCIS (Netherlands)

Sijtsma, P.

2018-01-01

This paper proposes a fast method for calculating the acoustic time delay between an observer and a receiver in a shear flow. This method is applied to an outdoor microphone array measurement on a large-scale wind turbine. In such a set-up, a shear flow represents the actual wind field better than a

Is central dogma a global property of cellular information flow?

Directory of Open Access Journals (Sweden)

Vincent ePiras

2012-11-01

Full Text Available The central dogma of molecular biology has come under scrutiny in recent years. Here, we reviewed high-throughput mRNA and protein expression data of Escherichia coli, Saccharomyces cerevisiae, and several mammalian cells. At both single cell and population scales, the statistical comparisons between the entire transcriptomes and proteomes show clear correlation structures. In contrast, the pair-wise correlations of single transcript to protein show nullity. These data suggest that the organizing structure guiding cellular processes is observed at omics-wide scale and not at single molecule level. The central dogma, thus, globally emerges as an average integrated flow of cellular information.

An information system for sustainable materials management with material flow accounting and waste input–output analysis

Directory of Open Access Journals (Sweden)

Pi-Cheng Chen

2017-05-01

Full Text Available Sustainable materials management focuses on the dynamics of materials in economic and environmental activities to optimize material use efficiency and reduce environmental impact. A preliminary web-based information system is thus developed to analyze the issues of resource consumption and waste generation, enabling countries to manage resources and wastes from a life cycle perspective. This pioneering system features a four-layer framework that integrates information on physical flows and economic activities with material flow accounting and waste input–output table analysis. Within this framework, several applications were developed for different waste and resource management stakeholders. The hierarchical and interactive dashboards allow convenient overview of economy-wide material accounts, waste streams, and secondary resource circulation. Furthermore, the system can trace material flows through associated production supply chain and consumption activities. Integrated with economic models; this system can predict the possible overloading on the current waste management facility capacities and provide decision support for designing strategies to approach resource sustainability. The limitations of current system are specified for directing further enhancement of functionalities.

"Glitch Logic" and Applications to Computing and Information Security

Science.gov (United States)

Stoica, Adrian; Katkoori, Srinivas

2009-01-01

This paper introduces a new method of information processing in digital systems, and discusses its potential benefits to computing and information security. The new method exploits glitches caused by delays in logic circuits for carrying and processing information. Glitch processing is hidden to conventional logic analyses and undetectable by traditional reverse engineering techniques. It enables the creation of new logic design methods that allow for an additional controllable "glitch logic" processing layer embedded into a conventional synchronous digital circuits as a hidden/covert information flow channel. The combination of synchronous logic with specific glitch logic design acting as an additional computing channel reduces the number of equivalent logic designs resulting from synthesis, thus implicitly reducing the possibility of modification and/or tampering with the design. The hidden information channel produced by the glitch logic can be used: 1) for covert computing/communication, 2) to prevent reverse engineering, tampering, and alteration of design, and 3) to act as a channel for information infiltration/exfiltration and propagation of viruses/spyware/Trojan horses.

Identification of calculation hierarchy and information flow for postclosure performance assessment

International Nuclear Information System (INIS)

Avci, H.I.; Cunnane, J.C.; Brandstetter, A.

1990-01-01

A management tool consisting of calculation hierarchy and information flow diagrams is being prepared to address the resolution of major postclosure performance issues for a geologic high-level radioactive waste repository in the U.S.A. The diagrams will indicate the types of calculations and data needed to assess the postclosure performance of the repository. Separate diagrams will be generated for different scenario classes and conceptual models. The methodology used in developing these diagrams and their contents are illustrated for a single scenario and conceptual model. 5 refs., 5 figs

An Application of Alloy to Static Analysis for Secure Information Flow and Verification of Software Systems

National Research Council Canada - National Science Library

Shaffer, Alan B

2008-01-01

Within a multilevel secure (MLS) system, flaws in design and implementation can result in overt and covert channels, both of which may be exploited by malicious software to cause unauthorized information flows...

FAKTOR-FAKTOR YANG MEMPENGARUHI AUDIT DELAY PADA PERUSAHAAN-PERUSAHAAN GO PUBLIC DI BEJ

Directory of Open Access Journals (Sweden)

Reni Yendrawati

2017-03-01

Full Text Available Timeliness represented a very important matter in determining financial statementvalue. This research was purposed to investigate the influence of audit delay factors, namelycompany size, company that announced loss, level of company profitability, auditor’s opinionand industrial sector. Audit delay could affect the timeliness of accounting information releases,and it would be known that timeliness was associated with the market reaction to theinformation released. Sampels were selected by method of purposive sampling. Regressionanalysis was used to investigate audit delay factors. The results could be interpreted thataudit delays tended to be longer for the company that announced loss in non-manufacture’ssampel, auditor’s opinion in overall sampel and auditor’s opinion in non-manufacture’s sampel.

Delay-dependent exponential stability of cellular neural networks with time-varying delays

International Nuclear Information System (INIS)

Zhang Qiang; Wei Xiaopeng; Xu Jin

2005-01-01

The global exponential stability of cellular neural networks (CNNs) with time-varying delays is analyzed. Two new sufficient conditions ensuring global exponential stability for delayed CNNs are obtained. The conditions presented here are related to the size of delay. The stability results improve the earlier publications. Two examples are given to demonstrate the effectiveness of the obtained results

Denials and Delays of Radioactive Material Shipments

International Nuclear Information System (INIS)

El-Shinawy, R.M.K.

2011-01-01

delays of shipments of radioactive materials forms an important issue today. Radioactive materials need to be transported using all modes of transport for use in different applications such as public health, industry, research and production of nuclear power. The transport of radioactive materials is governed by national and international regulations, which are based on the International Atomic Energy Agency (IAEA) regulations for safe transport of radioactive materials (TS-R-1). These regulations ensure high standards of safety. Recently there were increasing numbers of instances of denials and delays of shipments of radioactive materials even when complying with the regulations. The denials and delays can result in difficulties to patients and others who rely on products sterilized by radiation. Therefore there is an urgent need for a universally accepted approach to solve this problem. In response, the IAEA has formed an International Steering Committee (ISC) on denials and delays of radioactive materials. Also, it designate the National Focal Points (NFP) representative to help the ISC members and the IAEA by informing about denial operations and how they can help. The Steering Committee developed and adopted an action plan which includes the action to be taken. This plan is based on: Awareness, Training, Communication, Lobbying for marketing, Economic and Harmonization among member states. It is important to work within the mandate of the ISC and in the line of action plan on denials and delays. It identified the following network members such as: National Focal Points, Regional Coordinators, National Committee, National Representative for different modes of transport and similar bodies, Carriers, Producers and Suppliers, Different civil societies, NGO's, Ministry of transport and others.

Factors influencing delay time and coronary arterial density during coronary angiography with DSCT.

Science.gov (United States)

Tang, Lijun; Zhu, Xiaomei; Xu, Yi; Yu, Tongfu; Xu, Hai; Tang, Jinhua; Dogra, Vikram; Wang, Dehang

2011-02-01

CT angiography (CTA) plays an important role in diagnosing coronary arterial disease. Delay time and density of the coronary arteries related with patient-specific factors are essential for getting an optimal CTA image. To investigate various factors influencing delay time and coronary arterial density during coronary CTA with dual source CT. One hundred and sixteen consecutive subjects who underwent cardiac DSCT with retrospective ECG-gating were included. Factors including gender, age, height, weight, transversal cardiac diameter (TCD), transversal thoracic diameter (TTD), heart rate (HR), body surface area (BSA = [weight × height/3600](1/2)) and cardiothoracic ratio (CTR = TCD/TTD) were recorded, measured and calculated before administration of contrast media during coronary CT angiography. Delay time was determined as duration from the beginning of the injection to the density in the descending aorta at the level of right main pulmonary artery reaching a threshold of 100 HU. Coronary arterial density was measured at the mid portion of the right coronary artery. Regression analysis and stepwise regression analysis were used to investigate the influence of these factors on delay time and coronary arterial density. Delay time decreased with an increasing HR and it was shorter in women than men. Delay time increased with an increasing TCD. Delay time could be predicted by the formula: DT = 16.651-0.110 × HR + 1.902 × gender + 0.394 × TCD (where DT is abbreviation for delay time, gender is 0 for women and 1 for men). Coronary arterial density decreased with an increasing HR and weight. Coronary arterial density could be predicted by the formula: CAD = 923.42-4.099 × HR-3.293 × weight (CAD = coronary arterial density). There was no relationship between the other factors mentioned above and delay time or coronary arterial density. Delay time is influenced by HR, gender and TCD. Coronary arterial density also changes with HR and weight. So HR, gender, TCD and

Stability switches, Hopf bifurcation and chaos of a neuron model with delay-dependent parameters

International Nuclear Information System (INIS)

Xu, X.; Hu, H.Y.; Wang, H.L.

2006-01-01

It is very common that neural network systems usually involve time delays since the transmission of information between neurons is not instantaneous. Because memory intensity of the biological neuron usually depends on time history, some of the parameters may be delay dependent. Yet, little attention has been paid to the dynamics of such systems. In this Letter, a detailed analysis on the stability switches, Hopf bifurcation and chaos of a neuron model with delay-dependent parameters is given. Moreover, the direction and the stability of the bifurcating periodic solutions are obtained by the normal form theory and the center manifold theorem. It shows that the dynamics of the neuron model with delay-dependent parameters is quite different from that of systems with delay-independent parameters only

When Delays Improve Memory: Stabilizing Memory in Children May Require Time.

Science.gov (United States)

Darby, Kevin P; Sloutsky, Vladimir M

2015-12-01

Memory is critical for learning, cognition, and cognitive development. Recent work has suggested that preschool-age children are vulnerable to catastrophic levels of memory interference, in which new learning dramatically attenuates memory for previously acquired knowledge. In the work reported here, we investigated the effects of consolidation on children's memory by introducing a 48-hr delay between learning and testing. In Experiment 1, the delay improved children's memory and eliminated interference. Results of Experiment 2 suggest that the benefit of this delay is limited to situations in which children are given enough information to form complex memory structures. These findings have important implications for understanding consolidation processes and memory development. © The Author(s) 2015.

Refuses and delays in the transportation by ship of radioactive material

International Nuclear Information System (INIS)

Xavier, Clarice; Sobreira, Ana Celia

2011-01-01

Some Class 7 materials can only be transported by ship, making that load and unload activities can be done in a port. In the Brazil, the port of Santos posses the most volume of cargo manipulation, and cargoes which contain radioactive material are always present with all manipulation requisites according to applicable regulations. The transport and manipulation operations of radioactive material are performed in accordance with national and international requisites but, some individuals posses yet a high risk perception according to our experience, involving members of Brazilian port authorities, the Navy and cargoes handlers at the ports. So, exist yet a high quantity of refuses and delays during the transport by ship. Therefore, a communication strategy was developed and applied, to inform the risk perception, supplying information on the very principles of ionizing radiation, legislation and uses of radiation, and so, diminishing the quantity of refuses and delays. From that initial communication strategy on, it becomes evident the necessity of training and conscience making a movement for the problem of refuses and delays be diminished

Assessing delay discounting in mice

OpenAIRE

Mitchell, Suzanne H.

2014-01-01

Delay discounting (also intertemporal choice or impulsive choice) is the process by which delayed outcomes, such as delayed food delivery, are valued less than the same outcomes delivered immediately or with a shorter delay. This process is of interest because many psychopathologies, including substance dependence, pathological gambling, attention deficit hyperactivity disorder and conduct disorder, are characterized by heightened levels of delay discounting. Some of these disorders are herit...

Modelling delays in pharmacokinetics

International Nuclear Information System (INIS)

Farooqi, Z.H.; Lambrecht, R.M.

1990-01-01

Linear system analysis has come to form the backbone of pharmacokinetics. Natural systems usually involve time delays, thus models incorporating them would be an order closer approximation to the real world compared to those that do not. Delays may be modelled in several ways. The approach considered in this study is to have a discrete-time delay dependent rate with the delay respresenting the duration between the entry of a drug into a compartment and its release in some form (may be as a metabolite) from the compartment. Such a delay may be because of one or more of several physiological reasons, like, formation of a reservoir, slow metabolism, or receptor binding. The mathematical structure this gives rise to is a system of delay-differential equations. Examples are given of simple one and two compartment systems with drugs like bumetanide, carbamazepine, and quinolone-caffeine interaction. In these examples generally a good fit is obtained and the suggested models form a good approximation. 21 refs., 6 figs

Dynamics of circadian thalamocortical flow of information during a peripheral neuropathic pain condition

Directory of Open Access Journals (Sweden)

Helder eCardoso-Cruz

2011-08-01

Full Text Available It is known that the thalamocortical loop plays a crucial role in the encoding of sensory-discriminative features of painful stimuli. However, only a few studies have addressed the changes in thalamocortical dynamics that may occur after the onset of chronic pain. Our goal was to evaluate how the induction of chronic neuropathic pain affected the flow of information within the thalamocortical loop throughout the brain states of the sleep-wake cycle. To address this issue we recorded local field potentials – LFPs – both before and after the establishment of neuropathic pain in awake freely moving adult rats chronically implanted with arrays of multielectrodes in the lateral thalamus and primary somatosensory cortex. Our results show that the neuropathic injury induced changes in the number of wake and slow-wave-sleep state episodes, and especially in the total number of transitions between brain states. Moreover, partial directed coherence – PDC – analysis revealed that the amount of information flow between cortex and thalamus in neuropathic animals decreased significantly, indicating that the overall thalamic activity had less weight over the cortical activity. However, thalamocortical LFPs displayed higher phase-locking during awake and slow-wave-sleep episodes after the nerve lesion, suggesting faster transmission of relevant information along the thalamocortical loop. The observed changes are in agreement with the hypothesis of thalamic dysfunction after the onset of chronic pain, and may result from diminished inhibitory effect of the primary somatosensory cortex over the lateral thalamus.

Perception of GMOs by scientists and practitioners--the critical role of information flow about transgenic organisms.

Science.gov (United States)

Małyska, Aleksandra; Maciąg, Kamil; Twardowski, Tomasz

2014-03-25

The issue of GMOs arouses constantly strong emotions in public discourse. At the same time opinions of people particularly interested in this issues such as researchers, or potential users of this technology (e.g. farmers) are rarely subjected to analysis. Moreover, lack of knowledge about the flow of information "from the laboratory to the consumer" hinders implementation of any changes in this field. By using triangulation (combining quantitative and qualitative research and the use of various research tools) we explored the attitudes of Polish scientists, agricultural advisers and farmers (large scale agricultural producers) to the use of GMOs in the economy. On the basis of the performed research we diagnosed the effectiveness of information flow among these groups about transgenic organisms. Copyright © 2013 Elsevier B.V. All rights reserved.

A case study on multi-lane roundabouts under congestion: Comparing software capacity and delay estimates with field data

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Xuanwu Chen

2016-04-01

Full Text Available Existing studies on modern roundabouts performance are mostly based on data from singe lane roundabouts that are not heavily congested. For planners and designers interested in building multilane roundabouts for intersections with potential growth in future traffic, there has been a lack of existing studies with field data that provide reference values in terms of capacity and delay measurements. With the intent of providing such reference values, a case study was conducted by using the East Dowling Road Roundabouts in Anchorage, Alaska, which are currently operating with extensive queues during the evening peak hours. This research used multiple video camcorders to capture vehicle turning movements at the roundabouts as well as the progression of vehicle queues at the roundabout entrance approaches. With these video records, the number of vehicles in the queues can be accurately counted in any single minute during the peak hours. This study shows that unbalanced entrance flow patterns (i.e., one entrance has significant higher flow than others can intensify the queue and delay for the overall roundabouts. Then various software packages including RODEL, SIDRA and VISSIM were used to estimate several performance measurements, such as capacity, queue length, and delay, compared with the collected field data. With the comparison, it is found that all the three software packages overestimate multi-lane roundabout capacity before calibration. With default parameters, SIDRA and VISSIM tend to underestimate delays and queue lengths for the multi-lane roundabouts under congestion, while RODEL results in higher delay and queue length estimations at most of the entrance approaches.

Dynamics of the congestion control model in underwater wireless sensor networks with time delay

International Nuclear Information System (INIS)

Dong, Tao; Hu, Wenjie; Liao, Xiaofeng

2016-01-01

In this paper, a congestion control model in underwater wireless sensor network with time delay is considered. First, the boundedness of the positive equilibrium, where the samples density is positive for each node and the different event flows coexist, is investigated, which implies that the samples density of sensor node cannot exceed the Environmental carrying capacity. Then, by considering the time delay can be regarded as a bifurcating parameter, the dynamical behaviors, which include local stability and Hopf bifurcation, are investigated. It is found that when the communication time delay passes a critical value, the system loses its stability and a Hopf bifurcation occurs, which means the underwater wireless sensor network will be congested, even collapsed. Furthermore, the direction and stability of the bifurcating periodic solutions are derived by applying the normal form theory and the center manifold theorem. Finally, some numerical examples are finally performed to verify the theoretical results.