WorldWideScience

Sample records for dynamic definition based

  1. Definition of an emotion-based controller for dynamical systems

    Directory of Open Access Journals (Sweden)

    José Danilo Rairán Antolines

    2012-09-01

    Full Text Available An enormous number of solutions have been proposed from the field of artificial intelligence in order to endow machines with the ability to make plans without human guidance. In this paper, we suggest emulated emotions to endow machines with the skills to make human-like decisions. The model is described using dynamical systems. Emotional states are defined in terms of the difference between a reference model and the trajectories of the system. For example, calmness is defined as the ideal emotional state, where there is agreement between the state of the system and the reference model. Finally, a basic architecture for this kind of emotional-based controller is provided together with some experimental results that illustrate its use.

  2. Dynamics of Situation Definition

    Science.gov (United States)

    Park, Dongseop; Moro, Yuji

    2006-01-01

    Situation definition is the process and product of actors' interpretive activities toward a given situation. By reviewing a number of psychological studies conducted in experimental settings, we found that the studies have only explicated a part of the situation definition process and have neglected its dynamic aspects. We need to focus on the…

  3. Dynamic HTML The Definitive Reference

    CERN Document Server

    Goodman, Danny

    2007-01-01

    Packed with information on the latest web specifications and browser features, this new edition is your ultimate one-stop resource for HTML, XHTML, CSS, Document Object Model (DOM), and JavaScript development. Here is the comprehensive reference for designers of Rich Internet Applications who need to operate in all modern browsers, including Internet Explorer 7, Firefox 2, Safari, and Opera. With this book, you can instantly see browser support for the latest standards-based technologies, including CSS Level 3, DOM Level 3, Web Forms 2.0, XMLHttpRequest for AJAX applications, JavaScript 1.7

  4. When does a protein become an allergen? Searching for a dynamic definition based on most advanced technology tools.

    Science.gov (United States)

    Mari, A

    2008-07-01

    Since the early beginning of allergology as a science considerable efforts have been made by clinicians and researchers to identify and characterize allergic triggers as raw allergenic materials, allergenic sources and tissues, and more recently basic allergenic structures defined as molecules. The last 15-20 years have witnessed many centres focusing on the identification and characterization of allergenic molecules leading to an expanding wealth of knowledge. The need to organize this information leads to the most important question 'when does a protein become an allergen?' In this article, I try to address this question by reviewing a few basic concepts of the immunology of IgE-mediated diseases, reporting on the current diagnostic and epidemiological tools used for allergic disease studies and discussing the usefulness of novel biotechnology tools (i.e. proteomics and molecular biology approaches), information technology tools (i.e. Internet-based resources) and microtechnology tools (i.e. proteomic microarray for IgE testing on molecular allergens). A step-wise staging of the identification and characterization process, including bench, clinical and epidemiological aspects, is proposed, in order to classify allergenic molecules dynamically. This proposal reflects the application and use of all the new tools available from current technologies.

  5. Definition of the key target volume in radiosurgical management of arteriovenous malformations: a new dynamic concept based on angiographic circulation time.

    Science.gov (United States)

    Valle, Ramiro Del; Zenteno, Marco; Jaramillo, José; Lee, Angel; De Anda, Salvador

    2008-12-01

    The cumulative experience worldwide indicates complete radiosurgical obliteration rates of brain arteriovenous malformations (AVMs) ranging from 35 to 90%. The purpose of this study was to propose a strategy to increase the obliteration rate for AVMs through the dynamic definition of the key target volume (KTV). A prospective series of patients harboring an AVM was assessed using digital subtraction angiography in which a digital counter was used to measure the several stages of the frame-by-frame circulation time. All the patients were analyzed using dynamic measurement planning to define the KTV, corresponding to the volume of the shunt with the least vascular resistance and the earliest venous drainage. All patients underwent catheter-based angiography, a subgroup was additionally assessed by means of a superselective catheterization, and among these a further subgroup received embolization. The shunts were also categorized according to their angioarchitectural type: fistulous, plexiform, or mixed. The authors applied the radiosurgery-based grading system (RBGS) as well to find a correlation with the obliteration rate. This series includes 44 patients treated by radiosurgery; global angiography was performed for all patients, including dynamic measurement planning. Eighty-four percent of them underwent superselective catheterization, and 50% of the total population underwent embolization. In the embolized arm of the study, the pretreatment volume was up to 120 ml. In patients with a single treatment, the mean volume was 8.5 ml, and the median volume was 6.95 +/- 4.56 ml (mean +/- standard deviation), with a KTV of up to 15 ml. For prospectively staged radiosurgery, the mean KTV was 28 ml. The marginal radiation dose was 18-22 Gy, with a mean of dose 20 Gy. The mean RBGS score was 1.70. The overall obliteration rate was 91%, including the repeated radiosurgery group (4 patients), in which 100% showed complete obliteration. The overall permanent deficit was 2 of

  6. Dual, use-based definition of "system"

    CSIR Research Space (South Africa)

    Gonçalves, DP

    2015-09-01

    Full Text Available The standard definition (ISO 15288, 2008) of the concept of a system is not complete and is the definition of a closed system. Such a definition is inadequate for systems engineering. A use-based definition is proposed which spans the open...

  7. Solar dynamic power system definition study

    Science.gov (United States)

    Wallin, Wayne E.; Friefeld, Jerry M.

    1988-01-01

    The solar dynamic power system design and analysis study compared Brayton, alkali-metal Rankine, and free-piston Stirling cycles with silicon planar and GaAs concentrator photovoltaic power systems for application to missions beyond the Phase 2 Space Station level of technology for all power systems. Conceptual designs for Brayton and Stirling power systems were developed for 35 kWe and 7 kWe power levels. All power systems were designed for 7-year end-of-life conditions in low Earth orbit. LiF was selected for thermal energy storage for the solar dynamic systems. Results indicate that the Stirling cycle systems have the highest performance (lowest weight and area) followed by the Brayton cycle, with photovoltaic systems considerably lower in performance. For example, based on the performance assumptions used, the planar silicon power system weight was 55 to 75 percent higher than for the Stirling system. A technology program was developed to address areas wherein significant performance improvements could be realized relative to the current state-of-the-art as represented by Space Station. In addition, a preliminary evaluation of hardenability potential found that solar dynamic systems can be hardened beyond the hardness inherent in the conceptual designs of this study.

  8. The Dynamic Definition of the Advertising Campaign Budget

    Directory of Open Access Journals (Sweden)

    Ostrianyn Serhii O.

    2017-10-01

    Full Text Available The article is aimed at exploring means for optimizing the budgeting of advertising activity, the optimal distribution of the advertising budget among several products, advertised by a company, and several advertising channels used during the distribution of an advertisement. The current status of the optimizationized budgeting models in the world and in Ukraine was analyzed. The topicality of scientific developments in this direction has been substantiated. The model is based on the non-linear logistics function of the response value of sales for the costs of placement of an advertising message, including market saturation effects and the accumulation of promotional effect. A complex advertising budgeting model has been proposed, which includes the dynamic definition of a budget constraint based on the expected sales return from a byed advertising campaign whose budget is being optimized. The proposed model allows to schedule advertising activities in conditions of uncertainty and rapid change of environment.

  9. Potential Originality and Effectiveness: The Dynamic Definition of Creativity

    Science.gov (United States)

    Corazza, Giovanni Emanuele

    2016-01-01

    Given the central role of creativity in the future post-information society, a call for a pragmatist approach to the study of creativity is advocated, that brings as a consequence the recognition of the dynamic nature of this phenomenon. At the foundation of the proposed new theoretical framework lies the definition of creativity itself, which is…

  10. based dynamic voltage restorer

    African Journals Online (AJOL)

    HOD

    operation due to presence of increased use of nonlinear loads (computers, microcontrollers ... simulations of a dynamic voltage restorer (DVR) was achieved using MATLAB/Simulink. ..... using Discrete PWM generator, then the IGBT inverter.

  11. Dynamic Target Definition: A novel approach for PTV definition in ion beam therapy

    International Nuclear Information System (INIS)

    Cabal, Gonzalo A.; Jäkel, Oliver

    2013-01-01

    Purpose: To present a beam arrangement specific approach for PTV definition in ion beam therapy. Materials and methods: By means of a Monte Carlo error propagation analysis a criteria is formulated to assess whether a voxel is safely treated. Based on this a non-isotropical expansion rule is proposed aiming to minimize the impact of uncertainties on the dose delivered. Results: The method is exemplified in two cases: a Head and Neck case and a Prostate case. In both cases the modality used is proton beam irradiation and the sources of uncertainties taken into account are positioning (set up) errors and range uncertainties. It is shown how different beam arrangements have an impact on plan robustness which leads to different target expansions necessary to assure a predefined level of plan robustness. The relevance of appropriate beam angle arrangements as a way to minimize uncertainties is demonstrated. Conclusions: A novel method for PTV definition in on beam therapy is presented. The method show promising results by improving the probability of correct dose CTV coverage while reducing the size of the PTV volume. In a clinical scenario this translates into an enhanced tumor control probability while reducing the volume of healthy tissue being irradiated

  12. Catalog of 199 register-based definitions of chronic conditions

    DEFF Research Database (Denmark)

    Hvidberg, Michael F; Johnsen, Søren P; Glümer, Charlotte

    2016-01-01

    INTRODUCTION: The aim of the current study was to present and discuss a broad range of register-based definitions of chronic conditions for use in register research, as well as the challenges and pitfalls when defining chronic conditions by the use of registers. MATERIALS AND METHODS: The definit......INTRODUCTION: The aim of the current study was to present and discuss a broad range of register-based definitions of chronic conditions for use in register research, as well as the challenges and pitfalls when defining chronic conditions by the use of registers. MATERIALS AND METHODS......: The definitions were defined based on information from nationwide Danish public healthcare registers. Medical and epidemiological specialists identified and grouped relevant diagnosis codes that covered chronic conditions, using the International Classification System version 10 (ICD-10). Where relevant...... definitions were proposed based on record linkage between multiple registers, including registers of prescribed drugs and use of general practitioners' services. CONCLUSIONS THIS STUDY PROVIDED A CATALOG OF REGISTER-BASED DEFINITIONS FOR CHRONIC CONDITIONS FOR USE IN HEALTHCARE PLANNING AND RESEARCH, WHICH IS...

  13. Second Law based definition of passivity/activity of devices

    Science.gov (United States)

    Sundqvist, Kyle M.; Ferry, David K.; Kish, Laszlo B.

    2017-10-01

    Recently, our efforts to clarify the old question, if a memristor is a passive or active device [1], triggered debates between engineers, who have had advanced definitions of passivity/activity of devices, and physicists with significantly different views about this seemingly simple question. This debate triggered our efforts to test the well-known engineering concepts about passivity/activity in a deeper way, challenging them by statistical physics. It is shown that the advanced engineering definition of passivity/activity of devices is self-contradictory when a thermodynamical system executing Johnson-Nyquist noise is present. A new, statistical physical, self-consistent definition based on the Second Law of Thermodynamics is introduced. It is also shown that, in a system with uniform temperature distribution, any rectifier circuitry that can rectify thermal noise must contain an active circuit element, according to both the engineering and statistical physical definitions.

  14. Contingent self-definition and amorphous regions: a dynamic approach to place brand architecture

    OpenAIRE

    Dinnie, Keith

    2017-01-01

    This article explores the concept of contingent self-definition, whereby place brands employ flexible self-definitional approaches in constructing their place brand architecture. Adopting a view of regions as social constructs, the article builds on and extends previous work on place brand architecture by identifying the underlying factors that drive contingent self-definition decisions. Based on an empirical study of professionals tasked with managing region brands in the Netherlands, eleven...

  15. A classical appraisal of quantum definitions of non-Markovian dynamics

    International Nuclear Information System (INIS)

    Vacchini, Bassano

    2012-01-01

    We consider the issue of non-Markovianity of a quantum dynamics starting from a comparison with the classical definition of Markovian processes. We point to the fact that two sufficient but not necessary signatures of non-Markovianity of a classical process find their natural quantum counterpart in recently introduced measures of quantum non-Markovianity. This behaviour is analysed in detail for quantum dynamics which can be built taking as input a class of classical processes. (paper)

  16. Definition of drug-resistant epilepsy: is it evidence based?

    Science.gov (United States)

    Wiebe, Samuel

    2013-05-01

    Clinical case definitions are the cornerstone of clinical communication and of clinical and epidemiologic research. The ramifications of establishing a case definition are extensive, including potentially large changes in epidemiologic estimates of frequency, and decisions for clinical management. Yet, defining a condition entails numerous challenges such as defining the scope and purpose, incorporating the strongest evidence base with clinical expertise, accounting for patients' values, and considering impact on care. The clinical case definition of drug-resistant epilepsy, in addition, must address what constitutes an adequate intervention for an individual drug, what are the outcomes of relevance, what period of observation is sufficient to determine success or failure, how many medications should be tried, whether seizure frequency should play a role, and what is the role of side effects and tolerability. On the other hand, the principles of evidence-based medicine (EBM) aim at providing a systematic approach to incorporating the best available evidence into the process of clinical decision for individual patients. The case definition of drug-resistant epilepsy proposed by the the International League Against Epilepsy (ILAE) in 2009 is evaluated in terms of the principles of EBM as well as the stated goals of the authors of the definition. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

  17. On the definition of equilibrium and non-equilibrium states in dynamical systems

    OpenAIRE

    Akimoto, Takuma

    2008-01-01

    We propose a definition of equilibrium and non-equilibrium states in dynamical systems on the basis of the time average. We show numerically that there exists a non-equilibrium non-stationary state in the coupled modified Bernoulli map lattice.

  18. Nonlinear dynamics based digital logic and circuits.

    Science.gov (United States)

    Kia, Behnam; Lindner, John F; Ditto, William L

    2015-01-01

    We discuss the role and importance of dynamics in the brain and biological neural networks and argue that dynamics is one of the main missing elements in conventional Boolean logic and circuits. We summarize a simple dynamics based computing method, and categorize different techniques that we have introduced to realize logic, functionality, and programmability. We discuss the role and importance of coupled dynamics in networks of biological excitable cells, and then review our simple coupled dynamics based method for computing. In this paper, for the first time, we show how dynamics can be used and programmed to implement computation in any given base, including but not limited to base two.

  19. Towards a formal definition of static and dynamic electronic correlations.

    Science.gov (United States)

    Benavides-Riveros, Carlos L; Lathiotakis, Nektarios N; Marques, Miguel A L

    2017-05-24

    Some of the most spectacular failures of density-functional and Hartree-Fock theories are related to an incorrect description of the so-called static electron correlation. Motivated by recent progress in the N-representability problem of the one-body density matrix for pure states, we propose a method to quantify the static contribution to the electronic correlation. By studying several molecular systems we show that our proposal correlates well with our intuition of static and dynamic electron correlation. Our results bring out the paramount importance of the occupancy of the highest occupied natural spin-orbital in such quantification.

  20. Towards a unified description of the hydrogen bond network of liquid water: A dynamics based approach

    International Nuclear Information System (INIS)

    Ozkanlar, Abdullah; Zhou, Tiecheng; Clark, Aurora E.

    2014-01-01

    The definition of a hydrogen bond (H-bond) is intimately related to the topological and dynamic properties of the hydrogen bond network within liquid water. The development of a universal H-bond definition for water is an active area of research as it would remove many ambiguities in the network properties that derive from the fixed definition employed to assign whether a water dimer is hydrogen bonded. This work investigates the impact that an electronic-structure based definition, an energetic, and a geometric definition of the H-bond has upon both topological and dynamic network behavior of simulated water. In each definition, the use of a cutoff (either geometric or energetic) to assign the presence of a H-bond leads to the formation of transiently bonded or broken dimers, which have been quantified within the simulation data. The relative concentration of transient species, and their duration, results in two of the three definitions sharing similarities in either topological or dynamic features (H-bond distribution, H-bond lifetime, etc.), however no two definitions exhibit similar behavior for both classes of network properties. In fact, two networks with similar local network topology (as indicated by similar average H-bonds) can have dramatically different global network topology (as indicated by the defect state distributions) and altered H-bond lifetimes. A dynamics based correction scheme is then used to remove artificially transient H-bonds and to repair artificially broken bonds within the network such that the corrected network exhibits the same structural and dynamic properties for two H-bond definitions (the properties of the third definition being significantly improved). The algorithm described represents a significant step forward in the development of a unified hydrogen bond network whose properties are independent of the original hydrogen bond definition that is employed

  1. Formal definition of coherency and computation of minimal cut sequences for binary dynamic and repairable systems

    International Nuclear Information System (INIS)

    Chaux, Pierre-Yves

    2013-01-01

    Preventive risk assessment of a complex system rely on a dynamic models which describe the link between the system failure and the scenarios of failure and repair events from its components. The qualitative analyses of a binary dynamic and repairable system is aiming at computing and analyse the scenarios that lead to the system failure. Since such systems describe a large set of those, only the most representative ones, called Minimal Cut Sequences (MCS), are of interest for the safety engineer. The lack of a formal definition for the MCS has generated multiple definitions either specific to a given model (and thus not generic) or informal. This work proposes i) a formal framework and definition for the MCS while staying independent of the reliability model used, ii) the methodology to compute them using property extracted from their formal definition, iii) an extension of the formal framework for multi-states components in order to perform the qualitative analyses of Boolean logic Driven Markov Processes (BDMP) models. Under the hypothesis that the scenarios implicitly described by any reliability model can always be represented by a finite automaton, this work is defining the coherency for dynamic and repairable systems as the way to give a minimal representation of all scenarios that are leading to the system failure. (author)

  2. Promoting Model-based Definition to Establish a Complete Product Definition.

    Science.gov (United States)

    Ruemler, Shawn P; Zimmerman, Kyle E; Hartman, Nathan W; Hedberg, Thomas; Feeny, Allison Barnard

    2017-05-01

    The manufacturing industry is evolving and starting to use 3D models as the central knowledge artifact for product data and product definition, or what is known as Model-based Definition (MBD). The Model-based Enterprise (MBE) uses MBD as a way to transition away from using traditional paper-based drawings and documentation. As MBD grows in popularity, it is imperative to understand what information is needed in the transition from drawings to models so that models represent all the relevant information needed for processes to continue efficiently. Finding this information can help define what data is common amongst different models in different stages of the lifecycle, which could help establish a Common Information Model. The Common Information Model is a source that contains common information from domain specific elements amongst different aspects of the lifecycle. To help establish this Common Information Model, information about how models are used in industry within different workflows needs to be understood. To retrieve this information, a survey mechanism was administered to industry professionals from various sectors. Based on the results of the survey a Common Information Model could not be established. However, the results gave great insight that will help in further investigation of the Common Information Model.

  3. The Dynamic Definition of the Advertising Campaign Budget

    OpenAIRE

    Ostrianyn Serhii O.

    2017-01-01

    The article is aimed at exploring means for optimizing the budgeting of advertising activity, the optimal distribution of the advertising budget among several products, advertised by a company, and several advertising channels used during the distribution of an advertisement. The current status of the optimizationized budgeting models in the world and in Ukraine was analyzed. The topicality of scientific developments in this direction has been substantiated. The model is based on the non-line...

  4. Feature-based tolerancing for intelligent inspection process definition

    International Nuclear Information System (INIS)

    Brown, C.W.

    1993-07-01

    This paper describes a feature-based tolerancing capability that complements a geometric solid model with an explicit representation of conventional and geometric tolerances. This capability is focused on supporting an intelligent inspection process definition system. The feature-based tolerance model's benefits include advancing complete product definition initiatives (e.g., STEP -- Standard for Exchange of Product model dam), suppling computer-integrated manufacturing applications (e.g., generative process planning and automated part programming) with product definition information, and assisting in the solution of measurement performance issues. A feature-based tolerance information model was developed based upon the notion of a feature's toleranceable aspects and describes an object-oriented scheme for representing and relating tolerance features, tolerances, and datum reference frames. For easy incorporation, the tolerance feature entities are interconnected with STEP solid model entities. This schema will explicitly represent the tolerance specification for mechanical products, support advanced dimensional measurement applications, and assist in tolerance-related methods divergence issues

  5. Definition of "banner clouds" based on time lapse movies

    OpenAIRE

    Schween , J. H.; Kuettner , J.; Reinert , D.; Reuder , J.; Wirth , V.

    2007-01-01

    International audience; Banner clouds appear on the leeward side of a mountain and resemble a banner or a flag. This article provides a comprehensive definition of "banner clouds". It is based primarily on an extensive collection of time lapse movies, but previous attempts at an explanation of this phenomenon are also taken into account. The following ingredients are considered essential: the cloud must be attached to the mountain but not appear on the windward side; the cloud must originate ...

  6. Definition of "banner clouds" based on time lapse movies

    Directory of Open Access Journals (Sweden)

    J. H. Schween

    2007-01-01

    Full Text Available Banner clouds appear on the leeward side of a mountain and resemble a banner or a flag. This article provides a comprehensive definition of "banner clouds". It is based primarily on an extensive collection of time lapse movies, but previous attempts at an explanation of this phenomenon are also taken into account. The following ingredients are considered essential: the cloud must be attached to the mountain but not appear on the windward side; the cloud must originate from condensation of water vapour contained in the air (rather than consist of blowing snow; the cloud must be persistent; and the cloud must not be of convective nature. The definition is illustrated and discussed with the help of still images and time lapse movies taken at Mount Zugspitze in the Bavarian Alps.

  7. Dynamics of subway networks based on vehicles operation timetable

    Science.gov (United States)

    Xiao, Xue-mei; Jia, Li-min; Wang, Yan-hui

    2017-05-01

    In this paper, a subway network is represented as a dynamic, directed and weighted graph, in which vertices represent subway stations and weights of edges represent the number of vehicles passing through the edges by considering vehicles operation timetable. Meanwhile the definitions of static and dynamic metrics which can represent vertices' and edges' local and global attributes are proposed. Based on the model and metrics, standard deviation is further introduced to study the dynamic properties (heterogeneity and vulnerability) of subway networks. Through a detailed analysis of the Beijing subway network, we conclude that with the existing network structure, the heterogeneity and vulnerability of the Beijing subway network varies over time when the vehicle operation timetable is taken into consideration, and the distribution of edge weights affects the performance of the network. In other words, although the vehicles operation timetable is restrained by the physical structure of the network, it determines the performances and properties of the Beijing subway network.

  8. Definition and dynamic control of a continuous chromatography process independent of cell culture titer and impurities.

    Science.gov (United States)

    Chmielowski, Rebecca A; Mathiasson, Linda; Blom, Hans; Go, Daniel; Ehring, Hanno; Khan, Heera; Li, Hong; Cutler, Collette; Lacki, Karol; Tugcu, Nihal; Roush, David

    2017-12-01

    Advances in cell culture technology have enabled the production of antibody titers upwards of 30g/L. These highly productive cell culture systems can potentially lead to productivity bottlenecks in downstream purification due to lower column loadings, especially in the primary capture chromatography step. Alternative chromatography solutions to help remedy this bottleneck include the utilization of continuous processing systems such as periodic counter-current chromatography (PCC). Recent studies have provided methods to optimize and improve the design of PCC for cell culture titers up to about 3g/L. This paper defines a continuous loading strategy for PCC that is independent of cell culture background and encompasses cell culture titers up to about 31g/L. Initial experimentation showed a challenge with determining a difference in change in UV280nm signal (ie. ΔUV) between cell culture feed and monoclonal antibody (mAb) concentration. Further investigation revealed UV280nm absorbance of the cell culture feedstock without antibody was outside of the linear range of detection for a given cell pathlength. Additional experimentation showed the difference in ΔUV for various cell culture feeds can be either theoretically predicted by Beer's Law given a known absorbance of the media background and impurities or experimentally determined using various UV280nm cell pathlengths. Based on these results, a 0.35mm pathlength at UV280nm was chosen for dynamic control to overcome the background signal. The pore diffusion model showed good agreement with the experimental frontal analysis data, which resulted in definition of a ΔUV setpoint range between 20 and 70% for 3C-PCC experiments. Product quality of the elution pools was acceptable between various cell culture feeds and titers up to about 41g/L. Results indicated the following ΔUV setpoints to achieve robust dynamic control and maintain 3C-PCC yield: ∼20-45% for titers greater than 10g/L depending on UV absorbance of

  9. Conceptual definition of a technology development mission for advanced solar dynamic power systems

    Science.gov (United States)

    Migra, R. P.

    1986-01-01

    An initial conceptual definition of a technology development mission for advanced solar dynamic power systems is provided, utilizing a space station to provide a dedicated test facility. The advanced power systems considered included Brayton, Stirling, and liquid metal Rankine systems operating in the temperature range of 1040 to 1400 K. The critical technologies for advanced systems were identified by reviewing the current state of the art of solar dynamic power systems. The experimental requirements were determined by planning a system test of a 20 kWe solar dynamic power system on the space station test facility. These requirements were documented via the Mission Requirements Working Group (MRWG) and Technology Development Advocacy Group (TDAG) forms. Various concepts or considerations of advanced concepts are discussed. A preliminary evolutionary plan for this technology development mission was prepared.

  10. Proposal for a definition of lifelong premature ejaculation based on epidemiological stopwatch data

    NARCIS (Netherlands)

    Waldinger, Marcel D.; Zwinderman, Aeilko H.; Olivier, Berend; Schweitzer, Dave H.

    2005-01-01

    Introduction. Consensus on a definition of premature ejaculation has not yet been reached because of debates based on subjective authority opinions and nonstandardized assessment methods to measure ejaculation time and ejaculation control. Aim. To provide a definition for lifelong premature

  11. Opinion dynamics model based on quantum formalism

    Energy Technology Data Exchange (ETDEWEB)

    Artawan, I. Nengah, E-mail: nengahartawan@gmail.com [Theoretical Physics Division, Department of Physics, Udayana University (Indonesia); Trisnawati, N. L. P., E-mail: nlptrisnawati@gmail.com [Biophysics, Department of Physics, Udayana University (Indonesia)

    2016-03-11

    Opinion dynamics model based on quantum formalism is proposed. The core of the quantum formalism is on the half spin dynamics system. In this research the implicit time evolution operators are derived. The analogy between the model with Deffuant dan Sznajd models is discussed.

  12. Color image definition evaluation method based on deep learning method

    Science.gov (United States)

    Liu, Di; Li, YingChun

    2018-01-01

    In order to evaluate different blurring levels of color image and improve the method of image definition evaluation, this paper proposed a method based on the depth learning framework and BP neural network classification model, and presents a non-reference color image clarity evaluation method. Firstly, using VGG16 net as the feature extractor to extract 4,096 dimensions features of the images, then the extracted features and labeled images are employed in BP neural network to train. And finally achieve the color image definition evaluation. The method in this paper are experimented by using images from the CSIQ database. The images are blurred at different levels. There are 4,000 images after the processing. Dividing the 4,000 images into three categories, each category represents a blur level. 300 out of 400 high-dimensional features are trained in VGG16 net and BP neural network, and the rest of 100 samples are tested. The experimental results show that the method can take full advantage of the learning and characterization capability of deep learning. Referring to the current shortcomings of the major existing image clarity evaluation methods, which manually design and extract features. The method in this paper can extract the images features automatically, and has got excellent image quality classification accuracy for the test data set. The accuracy rate is 96%. Moreover, the predicted quality levels of original color images are similar to the perception of the human visual system.

  13. Developing syndrome definitions based on consensus and current use

    Science.gov (United States)

    Dowling, John N; Baer, Atar; Buckeridge, David L; Cochrane, Dennis; Conway, Michael A; Elkin, Peter; Espino, Jeremy; Gunn, Julia E; Hales, Craig M; Hutwagner, Lori; Keller, Mikaela; Larson, Catherine; Noe, Rebecca; Okhmatovskaia, Anya; Olson, Karen; Paladini, Marc; Scholer, Matthew; Sniegoski, Carol; Thompson, David; Lober, Bill

    2010-01-01

    Objective Standardized surveillance syndromes do not exist but would facilitate sharing data among surveillance systems and comparing the accuracy of existing systems. The objective of this study was to create reference syndrome definitions from a consensus of investigators who currently have or are building syndromic surveillance systems. Design Clinical condition–syndrome pairs were catalogued for 10 surveillance systems across the United States and the representatives of these systems were brought together for a workshop to discuss consensus syndrome definitions. Results Consensus syndrome definitions were generated for the four syndromes monitored by the majority of the 10 participating surveillance systems: Respiratory, gastrointestinal, constitutional, and influenza-like illness (ILI). An important element in coming to consensus quickly was the development of a sensitive and specific definition for respiratory and gastrointestinal syndromes. After the workshop, the definitions were refined and supplemented with keywords and regular expressions, the keywords were mapped to standard vocabularies, and a web ontology language (OWL) ontology was created. Limitations The consensus definitions have not yet been validated through implementation. Conclusion The consensus definitions provide an explicit description of the current state-of-the-art syndromes used in automated surveillance, which can subsequently be systematically evaluated against real data to improve the definitions. The method for creating consensus definitions could be applied to other domains that have diverse existing definitions. PMID:20819870

  14. An evidence-based definition of lifelong premature ejaculation: report of the International Society for Sexual Medicine (ISSM) ad hoc committee for the definition of premature ejaculation

    NARCIS (Netherlands)

    McMahon, Chris G.; Althof, Stanley E.; Waldinger, Marcel D.; Porst, Hartmut; Dean, John; Sharlip, Ira D.; Adaikan, P. G.; Becher, Edgardo; Broderick, Gregory A.; Buvat, Jacques; Dabees, Khalid; Giraldi, Annamaria; Giuliano, François; Hellstrom, Wayne J. G.; Incrocci, Luca; Laan, Ellen; Meuleman, Eric; Perelman, Michael A.; Rosen, Raymond C.; Rowland, David L.; Segraves, Robert

    2008-01-01

    The medical literature contains several definitions of premature ejaculation (PE). The most commonly quoted definition, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision, and other definitions of PE are all authority based

  15. An evidence-based definition of lifelong premature ejaculation: report of the International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation

    NARCIS (Netherlands)

    McMahon, Chris G.; Althof, Stanley; Waldinger, Marcel D.; Porst, Hartmut; Dean, John; Sharlip, Ira; Adaikan, P. G.; Becher, Edgardo; Broderick, Gregory A.; Buvat, Jacques; Dabees, Khalid; Giraldi, Annamaria; Giuliano, François; Hellstrom, Wayne J. G.; Incrocci, Luca; Laan, Ellen; Meuleman, Eric; Perelman, Michael A.; Rosen, Raymond; Rowland, David; Segraves, Robert

    2008-01-01

    To develop a contemporary, evidence-based definition of premature ejaculation (PE). There are several definitions of PE; the most commonly quoted, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders - 4th Edition - Text Revision, and other definitions of PE,

  16. Dynamic Control Based Photovoltaic Illuminating System

    Directory of Open Access Journals (Sweden)

    Zhang Chengkai

    2016-01-01

    Full Text Available Smart LED illumination system can use the power from whether the photovoltaic cell or the power grid automatically based on the SOC (State Of Charge of the photovoltaic cell. This paper proposes a feedback control of the photovoltaic cells and a dynamic control strategy for the Energy system. The dynamic control strategy is used to determine the switching state of the photovoltaic cell based on the illumination load in the past one hour and the battery capacity. These controls are manifested by experimental prototype that the control scheme is correct and effective.

  17. Consensus Based Definition of Growth Restriction in the Newborn.

    Science.gov (United States)

    Beune, Irene M; Bloomfield, Frank H; Ganzevoort, Wessel; Embleton, Nicholas D; Rozance, Paul J; van Wassenaer-Leemhuis, Aleid G; Wynia, Klaske; Gordijn, Sanne J

    2018-05-01

    To develop a consensus definition of growth restriction in the newborn that can be used clinically to identify newborn infants at risk and in research to harmonize reporting and definition in the current absence of a gold standard. An international panel of pediatric leaders in the field of neonatal growth were invited to participate in an electronic Delphi procedure using standardized methods and predefined consensus rules. Responses were fed back at group-level and the list of participants was provided. Nonresponders were excluded from subsequent rounds. In the first round, variables were scored on a 5-point Likert scale; in subsequent rounds, inclusion of variables and cut-offs were determined with a 70% level of agreement. In the final round participants selected the ultimate algorithm. In total, 57 experts participated in the first round; 79% completed the procedure. Consensus was reached on the following definition: birth weight less than the third percentile, or 3 out of the following: birth weight definition for growth restriction in the newborn. This definition recognizes that infants with birth weights 10th percentile can be growth restricted. This definition can be adopted in clinical practice and in clinical trials to better focus on newborns at risk, and is complementary to the previously determined definition of fetal growth restriction. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Dendrimer-based dynamic combinatorial libraries

    NARCIS (Netherlands)

    Chang, T.; Meijer, E.W.

    2005-01-01

    The aim of this project is to create water-sol. dynamic combinatorial libraries based upon dendrimer-guest complexes. The guest mols. are designed to bind to dendrimers using multiple secondary interactions, such as electrostatics and hydrogen bonding. We have been able to incorporate various guest

  19. Validity of calendar day-based definitions for community-onset bloodstream infections.

    Science.gov (United States)

    Laupland, Kevin B; Gregson, Daniel B; Church, Deirdre L

    2015-04-02

    Community-onset (CO) bloodstream infections (BSI) are those BSI where the blood culture is drawn culture draw or hospital admission are not always available. We evaluated the validity of using 2- or 3- calendar day based definitions for CO-BSI by comparing to a "gold standard" 48-hour definition. Among the population-based cohort of 14,106 episodes of BSI studied, 10,543 were classified as CO based on "gold standard" 48-hour criteria. When 2-day and 3-day definitions were applied, 10,396 and 10,707 CO-BSI episodes were ascertained, respectively. All but 147 (1.4%) true CO-BSI cases were included by using the 2-day definition. When the 3-day definition was applied, all cases of CO-BSI were identified but and additional 164 (1.5%) cases of hospital-onset HO-BSI were also included. Thus the sensitivity and specificity of the 2-day definition was 98.6% and 100% and for the 3-day definition was 100% and 98.5%, respectively. Overall, only 311 (2.2%) cases were potentially miss-classifiable using either the 2- or 3-calendar day based definitions. Use of either a 2- or 3-day definition is highly accurate for classifying CO-BSI.

  20. Estimation of Cachexia among Cancer Patients Based on Four Definitions

    Directory of Open Access Journals (Sweden)

    Kathleen M. Fox

    2009-01-01

    Full Text Available Objectives. Estimate and compare the proportion of cancer patients with cachexia using different definitions from available clinical data. Methods. Electronic medical records were examined to estimate the proportion of cancer patients with cachexia using 4 definitions: (1 ICD-9 diagnostic code of 799.4 (cachexia, (2 ICD-9 diagnosis of cachexia, anorexia, abnormal weight loss, or feeding difficulties, (3 prescription for megestrol acetate, oxandrolone, somatropin, or dronabinol, and (4 ≥5% weight loss. Patients with cancer of the stomach, pancreas, lung, colon/rectum, head/neck, esophagus, prostate, breast, or liver diagnosed between 1999 and 2004 were followed for cachexia. Results. Of 8541 cancer patients (60% men and 55% Caucasian, cachexia was observed in 2.4% of patients using the cachexia diagnostic code, 5.5% expanded diagnoses, 6.4% prescription medication definition, and 14.7% with ≥5% weight loss. Conclusions. The proportion of patients with cachexia varied considerably depending upon the definition employed, indicating that a standard operational definition is needed.

  1. A definition for influenza pandemics based on historical records.

    Science.gov (United States)

    Potter, Chris W; Jennings, Roy

    2011-10-01

    To analyse the records of past influenza outbreaks to determine a definition for pandemics. Analysis of publications of large outbreaks of influenza which have occurred since 1889/90, and to match the results against the current definitions of an influenza pandemic. According to the general understanding of a pandemic, nine outbreaks of influenza since 1889/90 satisfy the definition; however, for two of these, occurring in 1900 and 1933, the data are limited. The special condition for an influenza pandemic requires, in one definition, that the virus strain responsible could not have arisen from the previous circulating strain by mutation; and in the second, that the new strain be a different subtype to the previously circulating strain. Both these restrictions deny pandemic status to two, and possibly three, influenza outbreaks which were pandemics according to the more general understanding of the term. These observations suggest that a re-evaluation of the criteria which define influenza pandemics should be carried out. The contradiction outlined above brings the previous definitions of an influenza pandemic into question; however, this can be resolved by defining an influenza pandemic by the following criteria. Thus, an influenza pandemic arises at a single, specific place and spreads rapidly to involve numerous countries. The haemagglutinin (HA) of the emergent virus does not cross-react serologically with the previously dominant virus strain(s), and there is a significant lack of immunity in the population against the emergent virus. These three criteria are interlinked and can be determined early to alert authorities who could respond appropriately. Other criteria associated with pandemics are necessarily retrospective, although important and valid. The implications of this definition are discussed. Copyright © 2011 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  2. Dynamic reliability of digital-based transmitters

    Energy Technology Data Exchange (ETDEWEB)

    Brissaud, Florent, E-mail: florent.brissaud.2007@utt.f [Institut National de l' Environnement Industriel et des Risques (INERIS), Parc Technologique Alata, BP 2, 60550 Verneuil-en-Halatte (France) and Universite de Technologie de Troyes - UTT, Institut Charles Delaunay - ICD and UMR CNRS 6279 STMR, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France); Smidts, Carol [Ohio State University (OSU), Nuclear Engineering Program, Department of Mechanical Engineering, Scott Laboratory, 201 W 19th Ave, Columbus OH 43210 (United States); Barros, Anne; Berenguer, Christophe [Universite de Technologie de Troyes (UTT), Institut Charles Delaunay (ICD) and UMR CNRS 6279 STMR, 12 rue Marie Curie, BP 2060, 10010 Troyes Cedex (France)

    2011-07-15

    Dynamic reliability explicitly handles the interactions between the stochastic behaviour of system components and the deterministic behaviour of process variables. While dynamic reliability provides a more efficient and realistic way to perform probabilistic risk assessment than 'static' approaches, its industrial level applications are still limited. Factors contributing to this situation are the inherent complexity of the theory and the lack of a generic platform. More recently the increased use of digital-based systems has also introduced additional modelling challenges related to specific interactions between system components. Typical examples are the 'intelligent transmitters' which are able to exchange information, and to perform internal data processing and advanced functionalities. To make a contribution to solving these challenges, the mathematical framework of dynamic reliability is extended to handle the data and information which are processed and exchanged between systems components. Stochastic deviations that may affect system properties are also introduced to enhance the modelling of failures. A formalized Petri net approach is then presented to perform the corresponding reliability analyses using numerical methods. Following this formalism, a versatile model for the dynamic reliability modelling of digital-based transmitters is proposed. Finally the framework's flexibility and effectiveness is demonstrated on a substantial case study involving a simplified model of a nuclear fast reactor.

  3. Interpreting Definitions of Public Relations: Self Assessment and a Symbolic Interactionism-Based Alternative.

    Science.gov (United States)

    Gordon, Joye C.

    1997-01-01

    Reviews several popular definitions of public relations; explicates the shared elements and assumptions inherent in these definitions. Presents an alternative conceptualization of public relations based upon Herbert Blumer's symbolic interactionism. Looks to stimulate questioning and self assessment and to introduce alternative goals, ideas, and…

  4. The Extremism of Two Variable Function Based on the Positive Definite Property

    Institute of Scientific and Technical Information of China (English)

    Lü Bao-xian; LI Xiu-li

    2004-01-01

    In this paper we give out a sufficientand solution of quadratic function's maximum with theory of quadratic form and give out the definition of the positivedefinite property of the following homogeneous polynomials of degree 2n two variables function, based on the definite of localmaximum of two variables function.

  5. Information model of trainee characteristics with definition of stochastic behavior of dynamic system

    Science.gov (United States)

    Sumin, V. I.; Smolentseva, T. E.; Belokurov, S. V.; Lankin, O. V.

    2018-03-01

    In the work the process of formation of trainee characteristics with their subsequent change is analyzed and analyzed. Characteristics of trainees were obtained as a result of testing for each section of information on the chosen discipline. The results obtained during testing were input to the dynamic system. The area of control actions consisting of elements of the dynamic system is formed. The limit of deterministic predictability of element trajectories in dynamical systems based on local or global attractors is revealed. The dimension of the phase space of the dynamic system is determined, which allows estimating the parameters of the initial system. On the basis of time series of observations, it is possible to determine the predictability interval of all parameters, which make it possible to determine the behavior of the system discretely in time. Then the measure of predictability will be the sum of Lyapunov’s positive indicators, which are a quantitative measure for all elements of the system. The components for the formation of an algorithm allowing to determine the correlation dimension of the attractor for known initial experimental values of the variables are revealed. The generated algorithm makes it possible to carry out an experimental study of the dynamics of changes in the trainee’s parameters with initial uncertainty.

  6. Towards the molecular bases of polymerase dynamics

    International Nuclear Information System (INIS)

    Chela Flores, J.

    1991-03-01

    One aspect of the strong relationship that is known to exist between the processes of DNA replication and transcription is manifest in the coupling of the rates of movement of the replication fork (r f ) and RNA polymerase (r t ). We address two issues concerning the largely unexplored area of polymerase dynamics: (i) The validity of an approximate kinematic formula linking r f and r t suggested by experiments in which transcription is initiated in some prokaryotes with the antibiotic streptolydigin, and (ii) What are the molecular bases of the kinematic formula? An analysis of the available data suggests possible molecular bases for polymerase dynamics. In particular, we are led to a hypothesis: In active chromatin r t may depend on the length (λ t ) of the transcript of the primary messenger RNA (pre-mRNA). This new effect is subject to experimental verification. We discuss possible experiments that may be performed in order to test this prediction. (author). Refs, 6 tabs

  7. Keystroke Dynamics-Based Credential Hardening Systems

    Science.gov (United States)

    Bartlow, Nick; Cukic, Bojan

    abstract Keystroke dynamics are becoming a well-known method for strengthening username- and password-based credential sets. The familiarity and ease of use of these traditional authentication schemes combined with the increased trustworthiness associated with biometrics makes them prime candidates for application in many web-based scenarios. Our keystroke dynamics system uses Breiman’s random forests algorithm to classify keystroke input sequences as genuine or imposter. The system is capable of operating at various points on a traditional ROC curve depending on application-specific security needs. As a username/password authentication scheme, our approach decreases the system penetration rate associated with compromised passwords up to 99.15%. Beyond presenting results demonstrating the credential hardening effect of our scheme, we look into the notion that a user’s familiarity to components of a credential set can non-trivially impact error rates.

  8. Recurrence of Dupuytren's contracture: A consensus-based definition.

    Directory of Open Access Journals (Sweden)

    Hester J Kan

    Full Text Available One of the major determinants of Dupyutren disease (DD treatment efficacy is recurrence of the contracture. Unfortunately, lack of agreement in the literature on what constitutes recurrence makes it nearly impossible to compare the multiple treatments alternatives available today. The aim of this study is to bring an unbiased pool of experts to agree upon what would be considered a recurrence of DD after treatment; and from that consensus establish a much-needed definition for DD recurrence.To reach an expert consensus on the definition of recurrence we used the Delphi method and invited 43 Dupuytren's research and treatment experts from 10 countries to participate by answering a series of questionnaire rounds. After each round the answers were analyzed and the experts received a feedback report with another questionnaire round to further hone in of the definition. We defined consensus when at least 70% of the experts agreed on a topic.Twenty-one experts agreed to participate in this study. After four consensus rounds, we agreed that DD recurrence should be defined as "more than 20 degrees of contracture recurrence in any treated joint at one year post-treatment compared to six weeks post-treatment". In addition, "recurrence should be reported individually for every treated joint" and afterwards measurements should be repeated and reported yearly.This study provides the most comprehensive to date definition of what should be considered recurrence of DD. These standardized criteria should allow us to better evaluate the many treatment alternatives.

  9. SLAM - Based Approach to Dynamic Ship Positioning

    Directory of Open Access Journals (Sweden)

    Krzysztof Wrobel

    2014-03-01

    Full Text Available Dynamically positioned vessels, used by offshore industry, use not only satellite navigation but also different positioning systems, often referred to as reference' systems. Most of them use multiple technical devices located outside the vessel which creates some problems with their accessibility and performance. In this paper, a basic concept of reference system independent from any external device is presented, basing on hydroacoustics and Simultaneous Localization and Mapping (SLAM method. Theoretical analysis of its operability is also performed.

  10. Extended definitions of wake fields and their influence on beam dynamics

    Directory of Open Access Journals (Sweden)

    V. Danilov

    2000-01-01

    Full Text Available Based on experience gained from present machines, a new generation of accelerators with high intensities and low losses is being designed. For example, the design for the Spallation Neutron Source storage ring specifies fractional beam losses of the order of 10^{-4}, so that even small instabilities or resonances can lead to the violation of this number. The purpose of this paper is to show that there exist potentially important beam fields, missing from standard analyses, that can lead either to instabilities or to large deviations of instability thresholds from their conventional values. Some of these fields and related effects, e.g., “fast damping,” were discovered earlier and are presented here in more standard form as an extension of the wake field's definition. In addition, nonrelativistic collective phenomena are analyzed. It is shown that the nonrelativistic case could be significantly different from the relativistic case.

  11. Claims-based definition of death in Japanese claims database: validity and implications.

    Science.gov (United States)

    Ooba, Nobuhiro; Setoguchi, Soko; Ando, Takashi; Sato, Tsugumichi; Yamaguchi, Takuhiro; Mochizuki, Mayumi; Kubota, Kiyoshi

    2013-01-01

    For the pending National Claims Database in Japan, researchers will not have access to death information in the enrollment files. We developed and evaluated a claims-based definition of death. We used healthcare claims and enrollment data between January 2005 and August 2009 for 195,193 beneficiaries aged 20 to 74 in 3 private health insurance unions. We developed claims-based definitions of death using discharge or disease status and Charlson comorbidity index (CCI). We calculated sensitivity, specificity and positive predictive values (PPVs) using the enrollment data as a gold standard in the overall population and subgroups divided by demographic and other factors. We also assessed bias and precision in two example studies where an outcome was death. The definition based on the combination of discharge/disease status and CCI provided moderate sensitivity (around 60%) and high specificity (99.99%) and high PPVs (94.8%). In most subgroups, sensitivity of the preferred definition was also around 60% but varied from 28 to 91%. In an example study comparing death rates between two anticancer drug classes, the claims-based definition provided valid and precise hazard ratios (HRs). In another example study comparing two classes of anti-depressants, the HR with the claims-based definition was biased and had lower precision than that with the gold standard definition. The claims-based definitions of death developed in this study had high specificity and PPVs while sensitivity was around 60%. The definitions will be useful in future studies when used with attention to the possible fluctuation of sensitivity in some subpopulations.

  12. Claims-Based Definition of Death in Japanese Claims Database: Validity and Implications

    Science.gov (United States)

    Ooba, Nobuhiro; Setoguchi, Soko; Ando, Takashi; Sato, Tsugumichi; Yamaguchi, Takuhiro; Mochizuki, Mayumi; Kubota, Kiyoshi

    2013-01-01

    Background For the pending National Claims Database in Japan, researchers will not have access to death information in the enrollment files. We developed and evaluated a claims-based definition of death. Methodology/Principal Findings We used healthcare claims and enrollment data between January 2005 and August 2009 for 195,193 beneficiaries aged 20 to 74 in 3 private health insurance unions. We developed claims-based definitions of death using discharge or disease status and Charlson comorbidity index (CCI). We calculated sensitivity, specificity and positive predictive values (PPVs) using the enrollment data as a gold standard in the overall population and subgroups divided by demographic and other factors. We also assessed bias and precision in two example studies where an outcome was death. The definition based on the combination of discharge/disease status and CCI provided moderate sensitivity (around 60%) and high specificity (99.99%) and high PPVs (94.8%). In most subgroups, sensitivity of the preferred definition was also around 60% but varied from 28 to 91%. In an example study comparing death rates between two anticancer drug classes, the claims-based definition provided valid and precise hazard ratios (HRs). In another example study comparing two classes of anti-depressants, the HR with the claims-based definition was biased and had lower precision than that with the gold standard definition. Conclusions/Significance The claims-based definitions of death developed in this study had high specificity and PPVs while sensitivity was around 60%. The definitions will be useful in future studies when used with attention to the possible fluctuation of sensitivity in some subpopulations. PMID:23741526

  13. An evidence-based definition of lifelong premature ejaculation: report of the International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation.

    Science.gov (United States)

    McMahon, Chris G; Althof, Stanley; Waldinger, Marcel D; Porst, Hartmut; Dean, John; Sharlip, Ira; Adaikan, P G; Becher, Edgardo; Broderick, Gregory A; Buvat, Jacques; Dabees, Khalid; Giraldi, Annamaria; Giuliano, François; Hellstrom, Wayne J G; Incrocci, Luca; Laan, Ellen; Meuleman, Eric; Perelman, Michael A; Rosen, Raymond; Rowland, David; Segraves, Robert

    2008-08-01

    To develop a contemporary, evidence-based definition of premature ejaculation (PE). There are several definitions of PE; the most commonly quoted, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders - 4th Edition - Text Revision, and other definitions of PE, are all authority-based rather than evidence-based, and have no support from controlled clinical and/or epidemiological studies. Thus in August 2007, the International Society for Sexual Medicine (ISSM) appointed several international experts in PE to an Ad Hoc Committee for the Definition of PE. The committee met in Amsterdam in October 2007 to evaluate the strengths and weaknesses of current definitions of PE, to critically assess the evidence in support of the constructs of ejaculatory latency, ejaculatory control, sexual satisfaction and personal/interpersonal distress, and to propose a new evidence-based definition of PE. The Committee unanimously agreed that the constructs which are necessary to define PE are rapidity of ejaculation, perceived self-efficacy, and control and negative personal consequences from PE. The Committee proposed that lifelong PE be defined as a male sexual dysfunction characterized by ejaculation which always or nearly always occurs before or within about one minute of vaginal penetration, and the inability to delay ejaculation on all or nearly all vaginal penetrations, and negative personal consequences, such as distress, bother, frustration and/or the avoidance of sexual intimacy. This definition is limited to men with lifelong PE who engage in vaginal intercourse. The panel concluded that there are insufficient published objective data to propose an evidence-based definition of acquired PE. The ISSM definition of lifelong PE represents the first evidence-based definition of PE. This definition will hopefully lead to the development of new tools and patient-reported outcome measures for diagnosing and assessing the efficacy of treatment

  14. Cementing the foundations of thermodynamics: Comparison of system-based and surroundings-based definitions of work and heat

    International Nuclear Information System (INIS)

    Gislason, Eric A.; Craig, Norman C.

    2005-01-01

    The distinction between system-based and surroundings-based definitions of thermodynamic heat (q) and work (w), particularly pressure-volume work, in irreversible processes is introduced and cleanly drawn. A systematic presentation of system-based q and w is given for the first time. This development complements the authors' earlier presentation of surroundings-based work and heat. Either set of definitions can and has been used to develop the laws of thermodynamics. Both sets of definitions are used to analyze examples presented by Kivelson and Oppenheim (KO). It is seen for two KO processes that w(sys-based) and w(surr-based) are not equal. This not uncommon result does not violate the first law because the two q values are also different. One of the KO examples corresponds to a 'quasistatic' process, which is reversible from the point of view of the system but not from the point of view of the system plus surroundings taken together, and, therefore, not reversible overall. A number of reasons are given for preferring surroundings-based definitions of w and q to system-based definitions. Perhaps the most important is the fact that w(sys-based) does not always satisfy the theorem of maximum work in a constant temperature process. Finally, an explanation is presented for why the common use of two different sets of definitions for w and q has not led to greater confusion in the past

  15. Generic project definitions for improvement of health care delivery: a case-based approach.

    Science.gov (United States)

    Niemeijer, Gerard C; Does, Ronald J M M; de Mast, Jeroen; Trip, Albert; van den Heuvel, Jaap

    2011-01-01

    The purpose of this article is to create actionable knowledge, making the definition of process improvement projects in health care delivery more effective. This study is a retrospective analysis of process improvement projects in hospitals, facilitating a case-based reasoning approach to project definition. Data sources were project documentation and hospital-performance statistics of 271 Lean Six Sigma health care projects from 2002 to 2009 of general, teaching, and academic hospitals in the Netherlands and Belgium. Objectives and operational definitions of improvement projects in the sample, analyzed and structured in a uniform format and terminology. Extraction of reusable elements of earlier project definitions, presented in the form of 9 templates called generic project definitions. These templates function as exemplars for future process improvement projects, making the selection, definition, and operationalization of similar projects more efficient. Each template includes an explicated rationale, an operationalization in the form of metrics, and a prototypical example. Thus, a process of incremental and sustained learning based on case-based reasoning is facilitated. The quality of project definitions is a crucial success factor in pursuits to improve health care delivery. We offer 9 tried and tested improvement themes related to patient safety, patient satisfaction, and business-economic performance of hospitals.

  16. Dynamics-based centrality for directed networks.

    Science.gov (United States)

    Masuda, Naoki; Kori, Hiroshi

    2010-11-01

    Determining the relative importance of nodes in directed networks is important in, for example, ranking websites, publications, and sports teams, and for understanding signal flows in systems biology. A prevailing centrality measure in this respect is the PageRank. In this work, we focus on another class of centrality derived from the Laplacian of the network. We extend the Laplacian-based centrality, which has mainly been applied to strongly connected networks, to the case of general directed networks such that we can quantitatively compare arbitrary nodes. Toward this end, we adopt the idea used in the PageRank to introduce global connectivity between all the pairs of nodes with a certain strength. Numerical simulations are carried out on some networks. We also offer interpretations of the Laplacian-based centrality for general directed networks in terms of various dynamical and structural properties of networks. Importantly, the Laplacian-based centrality defined as the stationary density of the continuous-time random walk with random jumps is shown to be equivalent to the absorption probability of the random walk with sinks at each node but without random jumps. Similarly, the proposed centrality represents the importance of nodes in dynamics on the original network supplied with sinks but not with random jumps.

  17. Orthonormal Wavelet Bases for Quantum Molecular Dynamics

    International Nuclear Information System (INIS)

    Tymczak, C.; Wang, X.

    1997-01-01

    We report on the use of compactly supported, orthonormal wavelet bases for quantum molecular-dynamics (Car-Parrinello) algorithms. A wavelet selection scheme is developed and tested for prototypical problems, such as the three-dimensional harmonic oscillator, the hydrogen atom, and the local density approximation to atomic and molecular systems. Our method shows systematic convergence with increased grid size, along with improvement on compression rates, thereby yielding an optimal grid for self-consistent electronic structure calculations. copyright 1997 The American Physical Society

  18. Excited state dynamics of DNA bases

    Czech Academy of Sciences Publication Activity Database

    Kleinermanns, K.; Nachtigallová, Dana; de Vries, M. S.

    2013-01-01

    Roč. 32, č. 2 (2013), s. 308-342 ISSN 0144-235X R&D Projects: GA ČR GAP208/12/1318 Grant - others:National Science Foundation(US) CHE-0911564; NASA (US) NNX12AG77G; Deutsche Forschungsgemeinschaft(DE) SFB 663; Deutsche Forschungsgemeinschaft(DE) KI 531-29 Institutional support: RVO:61388963 Keywords : DNA bases * nucleobases * excited state * dynamics * computations * gas phase * conical intersections Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.920, year: 2013

  19. Agent-based modeling and network dynamics

    CERN Document Server

    Namatame, Akira

    2016-01-01

    The book integrates agent-based modeling and network science. It is divided into three parts, namely, foundations, primary dynamics on and of social networks, and applications. The book begins with the network origin of agent-based models, known as cellular automata, and introduce a number of classic models, such as Schelling’s segregation model and Axelrod’s spatial game. The essence of the foundation part is the network-based agent-based models in which agents follow network-based decision rules. Under the influence of the substantial progress in network science in late 1990s, these models have been extended from using lattices into using small-world networks, scale-free networks, etc. The book also shows that the modern network science mainly driven by game-theorists and sociophysicists has inspired agent-based social scientists to develop alternative formation algorithms, known as agent-based social networks. The book reviews a number of pioneering and representative models in this family. Upon the gi...

  20. Computer-based route-definition system for peripheral bronchoscopy.

    Science.gov (United States)

    Graham, Michael W; Gibbs, Jason D; Higgins, William E

    2012-04-01

    Multi-detector computed tomography (MDCT) scanners produce high-resolution images of the chest. Given a patient's MDCT scan, a physician can use an image-guided intervention system to first plan and later perform bronchoscopy to diagnostic sites situated deep in the lung periphery. An accurate definition of complete routes through the airway tree leading to the diagnostic sites, however, is vital for avoiding navigation errors during image-guided bronchoscopy. We present a system for the robust definition of complete airway routes suitable for image-guided bronchoscopy. The system incorporates both automatic and semiautomatic MDCT analysis methods for this purpose. Using an intuitive graphical user interface, the user invokes automatic analysis on a patient's MDCT scan to produce a series of preliminary routes. Next, the user visually inspects each route and quickly corrects the observed route defects using the built-in semiautomatic methods. Application of the system to a human study for the planning and guidance of peripheral bronchoscopy demonstrates the efficacy of the system.

  1. Validation of an algorithm-based definition of treatment resistance in patients with schizophrenia.

    Science.gov (United States)

    Ajnakina, Olesya; Horsdal, Henriette Thisted; Lally, John; MacCabe, James H; Murray, Robin M; Gasse, Christiane; Wimberley, Theresa

    2018-02-19

    Large-scale pharmacoepidemiological research on treatment resistance relies on accurate identification of people with treatment-resistant schizophrenia (TRS) based on data that are retrievable from administrative registers. This is usually approached by operationalising clinical treatment guidelines by using prescription and hospital admission information. We examined the accuracy of an algorithm-based definition of TRS based on clozapine prescription and/or meeting algorithm-based eligibility criteria for clozapine against a gold standard definition using case notes. We additionally validated a definition entirely based on clozapine prescription. 139 schizophrenia patients aged 18-65years were followed for a mean of 5years after first presentation to psychiatric services in South-London, UK. The diagnostic accuracy of the algorithm-based measure against the gold standard was measured with sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). A total of 45 (32.4%) schizophrenia patients met the criteria for the gold standard definition of TRS; applying the algorithm-based definition to the same cohort led to 44 (31.7%) patients fulfilling criteria for TRS with sensitivity, specificity, PPV and NPV of 62.2%, 83.0%, 63.6% and 82.1%, respectively. The definition based on lifetime clozapine prescription had sensitivity, specificity, PPV and NPV of 40.0%, 94.7%, 78.3% and 76.7%, respectively. Although a perfect definition of TRS cannot be derived from available prescription and hospital registers, these results indicate that researchers can confidently use registries to identify individuals with TRS for research and clinical practices. Copyright © 2018 Elsevier B.V. All rights reserved.

  2. A laser beam quality definition based on induced temperature rise.

    Science.gov (United States)

    Miller, Harold C

    2012-12-17

    Laser beam quality metrics like M(2) can be used to describe the spot sizes and propagation behavior of a wide variety of non-ideal laser beams. However, for beams that have been diffracted by limiting apertures in the near-field, or those with unusual near-field profiles, the conventional metrics can lead to an inconsistent or incomplete description of far-field performance. This paper motivates an alternative laser beam quality definition that can be used with any beam. The approach uses a consideration of the intrinsic ability of a laser beam profile to heat a material. Comparisons are made with conventional beam quality metrics. An analysis on an asymmetric Gaussian beam is used to establish a connection with the invariant beam propagation ratio.

  3. Making the Case for a Model-Based Definition of Engineering Materials (Postprint)

    Science.gov (United States)

    2017-09-12

    MBE relies on digi- tal representations, or a model-based definition (MBD), to define a product throughout design , manufacturing and sus- tainment...discovery through development, scale-up, product design and qualification, manufacture and sustainment have changed little over the past decades. This...testing data provided a certifiable material definition, so as to minimize risk and simplify procurement of materials during the design , manufacture , and

  4. Dynamic social networks based on movement

    Science.gov (United States)

    Scharf, Henry; Hooten, Mevin B.; Fosdick, Bailey K.; Johnson, Devin S.; London, Joshua M.; Durban, John W.

    2016-01-01

    Network modeling techniques provide a means for quantifying social structure in populations of individuals. Data used to define social connectivity are often expensive to collect and based on case-specific, ad hoc criteria. Moreover, in applications involving animal social networks, collection of these data is often opportunistic and can be invasive. Frequently, the social network of interest for a given population is closely related to the way individuals move. Thus, telemetry data, which are minimally invasive and relatively inexpensive to collect, present an alternative source of information. We develop a framework for using telemetry data to infer social relationships among animals. To achieve this, we propose a Bayesian hierarchical model with an underlying dynamic social network controlling movement of individuals via two mechanisms: an attractive effect and an aligning effect. We demonstrate the model and its ability to accurately identify complex social behavior in simulation, and apply our model to telemetry data arising from killer whales. Using auxiliary information about the study population, we investigate model validity and find the inferred dynamic social network is consistent with killer whale ecology and expert knowledge.

  5. Overdenture retained by teeth using a definitive denture base technique: a case report.

    Science.gov (United States)

    Nascimento, D F F; dos Santos, J F F; Marchini, L

    2010-09-01

    This paper presents a technique involving the use of a definitive denture base to make overdentures. Cores with ball attachments were cemented over remaining lower teeth. Impressions of the edentulous maxilla and mandible were taken to obtain a definitive acrylic resin base. The definitive base of the mandible was perforated at the location of ball attachments and its female components were fixed to the base using acrylic resin directly in the patient's mouth. Wax rims were then made, jaw relationships recorded, teeth mounted and tried in, and the dentures were cured. This technique allowed for easy fixing of female components and better retention during the recording of jaw relationships, and can also be used in the construction of implant retained dentures.

  6. Digital Communication Devices Based on Nonlinear Dynamics and Chaos

    National Research Council Canada - National Science Library

    Larson, Lawrence

    2003-01-01

    The final report of the ARO MURI "Digital Communications Based on Chaos and Nonlinear Dynamics" contains research results in the areas of chaos and nonlinear dynamics applied to wireless and optical communications...

  7. Base line definitions and methodological lessons from Zimbabwe

    International Nuclear Information System (INIS)

    Maya, R.S.

    1995-01-01

    The UNEP Greenhouse Gas Abatement Costing Studies carried out under the management of the UNEP Collaborating Centre On Energy and Environment at Risoe National Laboratories in Denmark has placed effort in generating methodological approaches to assessing the cost of abatement activities to reduce CO 2 emissions. These efforts have produced perhaps the most comprehensive set of methodological approaches to defining and assessing the cost of greenhouse gas abatement. Perhaps the most importance aspect of the UNEP study which involved teams of researchers from ten countries is the mix of countries in which the studies were conducted and hence the representation of views and concepts from researchers in these countries particularly those from developing countries namely, Zimbabwe, India, Venezuela, Brazil, Thailand and Senegal. Methodological lessons from Zimbabwe, therefore, would have benefited from the interactions with methodological experiences form the other participating countries. Methodological lessons from the Zimbabwean study can be placed in two categories. One relates to the modelling of tools to analyze economic trends and the various factors studied in order to determine the unit cost of CO 2 abatement. The other is the definition of factors influencing the levels of emissions reducible and those realised under specific economic trends. (au)

  8. Imaging-based logics for ornamental stone quality chart definition

    Science.gov (United States)

    Bonifazi, Giuseppe; Gargiulo, Aldo; Serranti, Silvia; Raspi, Costantino

    2007-02-01

    Ornamental stone products are commercially classified on the market according to several factors related both to intrinsic lythologic characteristics and to their visible pictorial attributes. Sometimes these latter aspects prevail in quality criteria definition and assessment. Pictorial attributes are in any case also influenced by the performed working actions and the utilized tools selected to realize the final stone manufactured product. Stone surface finishing is a critical task because it can contribute to enhance certain aesthetic features of the stone itself. The study was addressed to develop an innovative set of methodologies and techniques able to quantify the aesthetic quality level of stone products taking into account both the physical and the aesthetical characteristics of the stones. In particular, the degree of polishing of the stone surfaces and the presence of defects have been evaluated, applying digital image processing strategies. Morphological and color parameters have been extracted developing specific software architectures. Results showed as the proposed approaches allow to quantify the degree of polishing and to identify surface defects related to the intrinsic characteristics of the stone and/or the performed working actions.

  9. A new definition of burnout syndrome based on Farber's proposal

    Directory of Open Access Journals (Sweden)

    Mera Domingo

    2009-11-01

    Full Text Available Abstract Background Although diverse definitions have been construed for burnout syndrome, most authors consider it to be a single phenomenon, the result of chronic work-related stress. However, in order to enable specific intervention strategies to be adopted, it is first necessary to establish different profiles for the syndrome. In this respect, have been proposed three burnout types ("frenetic", "underchallenged" and "worn-out", each of which requires different means of dealing with frustration in the workplace. This study is an attempt to define and systematize the properties that characterize this typology proposal. Methods For this purpose, the documents considering preliminary typology were examined by means of qualitative content analysis supported by grounded theory. Semiotic analysis was then performed on the core category resulting from the previous analysis. Results A classification criterion, made up of three different burnout subtypes ("frenetic", "underchallenged", and "worn-out" capable of integrating the entire proposal was formulated. Discussion Understanding the development of burnout syndrome, as a succession of stages characterized by the progressive diminishing of dedication to work, could serve for the establishment of specific therapies and for the prevention of the syndrome.

  10. Update of the Case Definitions for Population-Based Surveillance of Periodontitis

    Science.gov (United States)

    Eke, Paul I.; Page, Roy C.; Wei, Liang; Thornton-Evans, Gina; Genco, Robert J.

    2018-01-01

    Background This report adds a new definition for mild periodontitis that allows for better descriptions of the overall prevalence of periodontitis in populations. In 2007, the Centers for Disease Control and Prevention in partnership with the American Academy of Periodontology developed and reported standard case definitions for surveillance of moderate and severe periodontitis based on measurements of probing depth (PD) and clinical attachment loss (AL) at interproximal sites. However, combined cases of moderate and severe periodontitis are insufficient to determine the total prevalence of periodontitis in populations. Methods The authors proposed a definition for mild periodontitis as ≥2 interproximal sites with AL ≥3 mm and ≥2 interproximal sites with PD ≥4 mm (not on the same tooth) or one site with PD ≥5 mm. The effect of the proposed definition on the total burden of periodontitis was assessed in a convenience sample of 456 adults ≥35 years old and compared with other previously reported definitions for similar categories of periodontitis. Results Addition of mild periodontitis increases the total prevalence of periodontitis by ≈31% in this sample when compared with the prevalence of severe and moderate disease. Conclusion Total periodontitis using the case definitions in this study should be based on the sum of mild, moderate, and severe periodontitis. PMID:22420873

  11. Mutually unbiased bases and semi-definite programming

    Energy Technology Data Exchange (ETDEWEB)

    Brierley, Stephen; Weigert, Stefan, E-mail: steve.brierley@ulb.ac.be, E-mail: stefan.weigert@york.ac.uk

    2010-11-01

    A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

  12. Mutually unbiased bases and semi-definite programming

    International Nuclear Information System (INIS)

    Brierley, Stephen; Weigert, Stefan

    2010-01-01

    A complex Hilbert space of dimension six supports at least three but not more than seven mutually unbiased bases. Two computer-aided analytical methods to tighten these bounds are reviewed, based on a discretization of parameter space and on Groebner bases. A third algorithmic approach is presented: the non-existence of more than three mutually unbiased bases in composite dimensions can be decided by a global optimization method known as semidefinite programming. The method is used to confirm that the spectral matrix cannot be part of a complete set of seven mutually unbiased bases in dimension six.

  13. Dynamics based alignment of proteins: an alternative approach to quantify dynamic similarity

    Directory of Open Access Journals (Sweden)

    Lyngsø Rune

    2010-04-01

    Full Text Available Abstract Background The dynamic motions of many proteins are central to their function. It therefore follows that the dynamic requirements of a protein are evolutionary constrained. In order to assess and quantify this, one needs to compare the dynamic motions of different proteins. Comparing the dynamics of distinct proteins may also provide insight into how protein motions are modified by variations in sequence and, consequently, by structure. The optimal way of comparing complex molecular motions is, however, far from trivial. The majority of comparative molecular dynamics studies performed to date relied upon prior sequence or structural alignment to define which residues were equivalent in 3-dimensional space. Results Here we discuss an alternative methodology for comparative molecular dynamics that does not require any prior alignment information. We show it is possible to align proteins based solely on their dynamics and that we can use these dynamics-based alignments to quantify the dynamic similarity of proteins. Our method was tested on 10 representative members of the PDZ domain family. Conclusions As a result of creating pair-wise dynamics-based alignments of PDZ domains, we have found evolutionarily conserved patterns in their backbone dynamics. The dynamic similarity of PDZ domains is highly correlated with their structural similarity as calculated with Dali. However, significant differences in their dynamics can be detected indicating that sequence has a more refined role to play in protein dynamics than just dictating the overall fold. We suggest that the method should be generally applicable.

  14. An evidence-based definition of lifelong premature ejaculation: report of the International Society for Sexual Medicine (ISSM) ad hoc committee for the definition of premature ejaculation.

    Science.gov (United States)

    McMahon, Chris G; Althof, Stanley E; Waldinger, Marcel D; Porst, Hartmut; Dean, John; Sharlip, Ira D; Adaikan, P G; Becher, Edgardo; Broderick, Gregory A; Buvat, Jacques; Dabees, Khalid; Giraldi, Annamaria; Giuliano, François; Hellstrom, Wayne J G; Incrocci, Luca; Laan, Ellen; Meuleman, Eric; Perelman, Michael A; Rosen, Raymond C; Rowland, David L; Segraves, Robert

    2008-07-01

    The medical literature contains several definitions of premature ejaculation (PE). The most commonly quoted definition, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision, and other definitions of PE are all authority based rather than evidence based, and have no support from controlled clinical and/or epidemiological studies. The aim of this article is to develop a contemporary, evidence-based definition of PE. In August 2007, the International Society for Sexual Medicine (ISSM) appointed several international experts in PE to an Ad Hoc Committee for the Definition of Premature Ejaculation. The committee met in Amsterdam in October 2007 to evaluate the strengths and weaknesses of current definitions of PE, to critique the evidence in support of the constructs of ejaculatory latency, ejaculatory control, sexual satisfaction, and personal/interpersonal distress, and to propose a new evidence-based definition of PE. The committee unanimously agreed that the constructs that are necessary to define PE are rapidity of ejaculation, perceived self-efficacy and control, and negative personal consequences from PE. The committee proposed that lifelong PE be defined as ". . . a male sexual dysfunction characterized by ejaculation which always or nearly always occurs prior to or within about one minute of vaginal penetration, and the inability to delay ejaculation on all or nearly all vaginal penetrations, and negative personal consequences, such as distress, bother, frustration and/or the avoidance of sexual intimacy." This definition is limited to men with lifelong PE who engage in vaginal intercourse. The panel concluded that there are insufficient published objective data to propose an evidence-based definition of acquired PE. The ISSM definition of lifelong PE represents the first evidence-based definition of PE. This definition will hopefully lead to the development of new tools and Patient Reported

  15. Diagnosing intramammary infections: evaluation of definitions based on a single milk sample.

    Science.gov (United States)

    Dohoo, I R; Smith, J; Andersen, S; Kelton, D F; Godden, S

    2011-01-01

    Criteria for diagnosing intramammary infections (IMI) have been debated for many years. Factors that may be considered in making a diagnosis include the organism of interest being found on culture, the number of colonies isolated, whether or not the organism was recovered in pure or mixed culture, and whether or not concurrent evidence of inflammation existed (often measured by somatic cell count). However, research using these criteria has been hampered by the lack of a "gold standard" test (i.e., a perfect test against which the criteria can be evaluated) and the need for very large data sets of culture results to have sufficient numbers of quarters with infections with a variety of organisms. This manuscript used 2 large data sets of culture results to evaluate several definitions (sets of criteria) for classifying a quarter as having, or not having an IMI by comparing the results from a single culture to a gold standard diagnosis based on a set of 3 milk samples. The first consisted of 38,376 milk samples from which 25,886 triplicate sets of milk samples taken 1 wk apart were extracted. The second consisted of 784 quarters that were classified as infected or not based on a set of 3 milk samples collected at 2-d intervals. From these quarters, a total of 3,136 additional samples were evaluated. A total of 12 definitions (named A to L) based on combinations of the number of colonies isolated, whether or not the organism was recovered in pure or mixed culture, and the somatic cell count were evaluated for each organism (or group of organisms) with sufficient data. The sensitivity (ability of a definition to detect IMI) and the specificity (Sp; ability of a definition to correctly classify noninfected quarters) were both computed. For all species, except Staphylococcus aureus, the sensitivity of all definitions was definition A). With the exception of "any organism" and coagulase-negative staphylococci, all Sp estimates were over 94% in the daily data and over 97

  16. High-definition velocity-space tomography of fast-ion dynamics

    DEFF Research Database (Denmark)

    Salewski, Mirko; Geiger, B.; Jacobsen, A.S.

    2016-01-01

    Velocity-space tomography of the fast-ion distribution function in a fusion plasma is usually a photon-starved tomography method due to limited optical access and signal-to-noise ratio of fast-ion Dα (FIDA) spectroscopy as well as the strive for high-resolution images. In high-definition tomography...... information to reconstruct where in velocity space the measurements and the simulation disagree. This alternative approach is demonstrated for four-view as well as for two-view FIDA measurements. The high-definition tomography tools allow us to study fast ions in sawtoothing plasmas and the formation of NBI...

  17. Component-Based Software Engineering and Runtime Type Definition

    OpenAIRE

    A. R. Shakurov

    2011-01-01

    The component-based approach to software engineering, its current implementations and their limitations are discussed. A new extended architecture for such systems is presented. Its main architectural concepts and principles are considered.

  18. Definition of a CDI metadata profile and its ISO 19139 based encoding

    Science.gov (United States)

    Boldrini, Enrico; de Korte, Arjen; Santoro, Mattia; Schaap, Dick M. A.; Nativi, Stefano; Manzella, Giuseppe

    2010-05-01

    The Common Data Index (CDI) is the middleware service adopted by SeaDataNet for discovery and query. The primary goal of the EU funded project SeaDataNet is to develop a system which provides transparent access to marine data sets and data products from 36 countries in and around Europe. The European context of SeaDataNet requires that the developed system complies with European Directive INSPIRE. In order to assure the required conformity a GI-cat based solution is proposed. GI-cat is a broker service able to mediate from different metadata sources and publish them through a consistent and unified interface. In this case GI-cat is used as a front end to the SeaDataNet portal publishing the original data, based on CDI v.1 XML schema, through an ISO 19139 application profile catalog interface (OGC CSW AP ISO). The choice of ISO 19139 is supported and driven by INSPIRE Implementing Rules, that have been used as a reference through the whole development process. A mapping from the CDI data model to the ISO 19139 was hence to be implemented in GI-cat and a first draft quickly developed, as both CDI v.1 and ISO 19139 happen to be XML implementations based on the same abstract data model (standard ISO 19115 - metadata about geographic information). This first draft mapping pointed out the CDI metadata model differences with respect to ISO 19115, as it was not possible to accommodate all the information contained in CDI v.1 into ISO 19139. Moreover some modifications were needed in order to reach INSPIRE compliance. The consequent work consisted in the definition of the CDI metadata model as a profile of ISO 19115. This included checking of all the metadata elements present in CDI and their cardinality. A comparison was made with respect to ISO 19115 and possible extensions were individuated. ISO 19139 was then chosen as a natural XML implementation of this new CDI metadata profile. The mapping and the profile definition processes were iteratively refined leading up to a

  19. Beyond Problem-Based Learning: Using Dynamic PBL in Chemistry

    Science.gov (United States)

    Overton, Tina L.; Randles, Christopher A.

    2015-01-01

    This paper describes the development and implementation of a novel pedagogy, dynamic problem-based learning. The pedagogy utilises real-world problems that evolve throughout the problem-based learning activity and provide students with choice and different data sets. This new dynamic problem-based learning approach was utilised to teach…

  20. Supply based on demand dynamical model

    Science.gov (United States)

    Levi, Asaf; Sabuco, Juan; Sanjuán, Miguel A. F.

    2018-04-01

    We propose and numerically analyze a simple dynamical model that describes the firm behaviors under uncertainty of demand. Iterating this simple model and varying some parameter values, we observe a wide variety of market dynamics such as equilibria, periodic, and chaotic behaviors. Interestingly, the model is also able to reproduce market collapses.

  1. Osteoporosis-related fracture case definitions for population-based administrative data

    Directory of Open Access Journals (Sweden)

    Lix Lisa M

    2012-05-01

    Full Text Available Abstract Background Population-based administrative data have been used to study osteoporosis-related fracture risk factors and outcomes, but there has been limited research about the validity of these data for ascertaining fracture cases. The objectives of this study were to: (a compare fracture incidence estimates from administrative data with estimates from population-based clinically-validated data, and (b test for differences in incidence estimates from multiple administrative data case definitions. Methods Thirty-five case definitions for incident fractures of the hip, wrist, humerus, and clinical vertebrae were constructed using diagnosis codes in hospital data and diagnosis and service codes in physician billing data from Manitoba, Canada. Clinically-validated fractures were identified from the Canadian Multicentre Osteoporosis Study (CaMos. Generalized linear models were used to test for differences in incidence estimates. Results For hip fracture, sex-specific differences were observed in the magnitude of under- and over-ascertainment of administrative data case definitions when compared with CaMos data. The length of the fracture-free period to ascertain incident cases had a variable effect on over-ascertainment across fracture sites, as did the use of imaging, fixation, or repair service codes. Case definitions based on hospital data resulted in under-ascertainment of incident clinical vertebral fractures. There were no significant differences in trend estimates for wrist, humerus, and clinical vertebral case definitions. Conclusions The validity of administrative data for estimating fracture incidence depends on the site and features of the case definition.

  2. Reconsidering the definition of Major Depression based on Collaborative Psychiatric Epidemiology Surveys.

    Science.gov (United States)

    Rosenström, Tom; Jokela, Markus

    2017-01-01

    Diagnostic definitions for depressive disorders remain a debated topic, despite their central role in clinical practice and research. We use both recent evidence and nationally representative data to derive an empirically-based modification of DSM-IV/-5 Major Depressive Disorder (MDD). A modified MDD diagnosis was derived by analyzing data from Collaborative Psychiatric Epidemiology Surveys, a multistage probability sample of adults (n=20 013; age ≥ 18 years) in coterminous USA, Alaska and Hawaii. The old and the newly suggested MDD definitions were compared for their associated disability (WHO Disability Assessment Schedule and number of disability days in past month), suicide attempt, and other covariates. Our data-driven definition for major depression was "lack of interest to all or most things" plus four other symptoms from the set {weight gain, weight loss, insomnia, psychomotor retardation, fatigue, feelings of worthlessness, diminished ability to think/concentrate, suicidal ideation/attempt}. The new definition captured all the disability implied by MDD and excluded cases that showed no greater disability than the general population nor increased risk of suicide attempts. The lifetime prevalence of the new diagnosis was 14.7% (95% CI=14-15.4%) of the population, slightly less than for the old definition (16.4%; CI=15.4-17.3%). Only conservative modifications of MDD could be studied, because of restrictions in the symptom data. With only small adjusting, the new definition for major depression may be more clinically relevant than the old one, and could serve as a conservative replacement for the old definition. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Generic project definitions for improvement of health care delivery: A case-base approach

    NARCIS (Netherlands)

    Niemeijer, G.C.; Does, R.J.M.M.; de Mast, J.; Trip, A.; van den Heuvel, J.

    2011-01-01

    Background: The purpose of this article is to create actionable knowledge, making the definition of process improvement projects in health care delivery more effective. Methods: This study is a retrospective analysis of process improvement projects in hospitals, facilitating a case-based reasoning

  4. Auditing description-logic-based medical terminological systems by detecting equivalent concept definitions

    NARCIS (Netherlands)

    Cornet, Ronald; Abu-Hanna, Ameen

    2008-01-01

    OBJECTIVE: To specify and evaluate a method for auditing medical terminological systems (TSs) based on detecting concepts with equivalent definitions. This method addresses two important problems: redundancy, where the same concept is represented more than once (described by different terms), and

  5. Computer holography: 3D digital art based on high-definition CGH

    International Nuclear Information System (INIS)

    Matsushima, K; Arima, Y; Nishi, H; Yamashita, H; Yoshizaki, Y; Ogawa, K; Nakahara, S

    2013-01-01

    Our recent works of high-definition computer-generated holograms (CGH) and the techniques used for the creation, such as the polygon-based method, silhouette method and digitized holography, are summarized and reviewed in this paper. The concept of computer holography is proposed in terms of integrating and crystalizing the techniques into novel digital art.

  6. Dynamic summarization of bibliographic-based data

    Directory of Open Access Journals (Sweden)

    Hurdle John F

    2011-02-01

    Full Text Available Abstract Background Traditional information retrieval techniques typically return excessive output when directed at large bibliographic databases. Natural Language Processing applications strive to extract salient content from the excessive data. Semantic MEDLINE, a National Library of Medicine (NLM natural language processing application, highlights relevant information in PubMed data. However, Semantic MEDLINE implements manually coded schemas, accommodating few information needs. Currently, there are only five such schemas, while many more would be needed to realistically accommodate all potential users. The aim of this project was to develop and evaluate a statistical algorithm that automatically identifies relevant bibliographic data; the new algorithm could be incorporated into a dynamic schema to accommodate various information needs in Semantic MEDLINE, and eliminate the need for multiple schemas. Methods We developed a flexible algorithm named Combo that combines three statistical metrics, the Kullback-Leibler Divergence (KLD, Riloff's RlogF metric (RlogF, and a new metric called PredScal, to automatically identify salient data in bibliographic text. We downloaded citations from a PubMed search query addressing the genetic etiology of bladder cancer. The citations were processed with SemRep, an NLM rule-based application that produces semantic predications. SemRep output was processed by Combo, in addition to the standard Semantic MEDLINE genetics schema and independently by the two individual KLD and RlogF metrics. We evaluated each summarization method using an existing reference standard within the task-based context of genetic database curation. Results Combo asserted 74 genetic entities implicated in bladder cancer development, whereas the traditional schema asserted 10 genetic entities; the KLD and RlogF metrics individually asserted 77 and 69 genetic entities, respectively. Combo achieved 61% recall and 81% precision, with an F

  7. A semantic-based method for extracting concept definitions from scientific publications: evaluation in the autism phenotype domain.

    Science.gov (United States)

    Hassanpour, Saeed; O'Connor, Martin J; Das, Amar K

    2013-08-12

    A variety of informatics approaches have been developed that use information retrieval, NLP and text-mining techniques to identify biomedical concepts and relations within scientific publications or their sentences. These approaches have not typically addressed the challenge of extracting more complex knowledge such as biomedical definitions. In our efforts to facilitate knowledge acquisition of rule-based definitions of autism phenotypes, we have developed a novel semantic-based text-mining approach that can automatically identify such definitions within text. Using an existing knowledge base of 156 autism phenotype definitions and an annotated corpus of 26 source articles containing such definitions, we evaluated and compared the average rank of correctly identified rule definition or corresponding rule template using both our semantic-based approach and a standard term-based approach. We examined three separate scenarios: (1) the snippet of text contained a definition already in the knowledge base; (2) the snippet contained an alternative definition for a concept in the knowledge base; and (3) the snippet contained a definition not in the knowledge base. Our semantic-based approach had a higher average rank than the term-based approach for each of the three scenarios (scenario 1: 3.8 vs. 5.0; scenario 2: 2.8 vs. 4.9; and scenario 3: 4.5 vs. 6.2), with each comparison significant at the p-value of 0.05 using the Wilcoxon signed-rank test. Our work shows that leveraging existing domain knowledge in the information extraction of biomedical definitions significantly improves the correct identification of such knowledge within sentences. Our method can thus help researchers rapidly acquire knowledge about biomedical definitions that are specified and evolving within an ever-growing corpus of scientific publications.

  8. Risk-Based Fire Safety Experiment Definition for Manned Spacecraft

    Science.gov (United States)

    Apostolakis, G. E.; Ho, V. S.; Marcus, E.; Perry, A. T.; Thompson, S. L.

    1989-01-01

    Risk methodology is used to define experiments to be conducted in space which will help to construct and test the models required for accident sequence identification. The development of accident scenarios is based on the realization that whether damage occurs depends on the time competition of two processes: the ignition and creation of an adverse environment, and the detection and suppression activities. If the fire grows and causes damage faster than it is detected and suppressed, then an accident occurred. The proposed integrated experiments will provide information on individual models that apply to each of the above processes, as well as previously unidentified interactions and processes, if any. Initially, models that are used in terrestrial fire risk assessments are considered. These include heat and smoke release models, detection and suppression models, as well as damage models. In cases where the absence of gravity substantially invalidates a model, alternate models will be developed. Models that depend on buoyancy effects, such as the multizone compartment fire models, are included in these cases. The experiments will be performed in a variety of geometries simulating habitable areas, racks, and other spaces. These simulations will necessitate theoretical studies of scaling effects. Sensitivity studies will also be carried out including the effects of varying oxygen concentrations, pressures, fuel orientation and geometry, and air flow rates. The experimental apparatus described herein includes three major modules: the combustion, the fluids, and the command and power modules.

  9. DYNAMICS OF Cercospora zeina POPULATIONS IN MAIZE-BASED ...

    African Journals Online (AJOL)

    ACSS

    DYNAMICS OFCercospora zeina POPULATIONS IN MAIZE-BASED AGRO- ..... Population differentiation of Cercospora zeina in three districts of Uganda based on analysis of molecular variance ..... interactions: The example of the Erysiphe.

  10. Definitions of medication-overuse headache in population-based studies and their implications on prevalence estimates

    DEFF Research Database (Denmark)

    Westergaard, Maria L; Hansen, Ebba Holme; Glümer, Charlotte

    2014-01-01

    Case definitions of medication-overuse headache (MOH) in population-based research have changed over time. This study aims to review MOH prevalence reports with respect to these changes, and to propose a practical case definition for future studies based on the ICHD-3 beta....

  11. Multiperipheral ring dynamics and a definition of the complete twisted Reggeon loop

    International Nuclear Information System (INIS)

    Lucht, P.H.

    1977-11-01

    The t less than 0 multiperipheral formalism of Ciafaloni, DeTar, Misheloff, Mueller, Muzinich and Yesian is reviewed, extended, and applied to the ordered S-matrix whose ring amplitudes comprise the zeroth level of the topological expansion. Toller M-function notation is used throughout. The bootstrap and cylinder problems are formulated in terms of a well defined helicity pole propagator; a definition of the complete twisted Reggeon loop, which appears in the one-twist term of the cylinder, is given as a helicity pole expansion. Some consideration is given to the following subjects: diagonalization, naturality, threshold behavior, Regge cuts, and complex helicity

  12. High-definition polymeric membranes: construction of 3D lithographed channel arrays through control of natural building blocks dynamics.

    Science.gov (United States)

    Speranza, Valentina; Trotta, Francesco; Drioli, Enrico; Gugliuzza, Annarosa

    2010-02-01

    The fabrication of well-defined interfaces is in high demand in many fields of biotechnologies. Here, high-definition membrane-like arrays are developed through the self-assembly of water droplets, which work as natural building blocks for the construction of ordered channels. Solution viscosity together with the dynamics of the water droplets can decide the final formation of three-dimensional well-ordered patterns resembling anodic structures, especially because solvents denser than water are used. Particularly, the polymer solution viscosity is demonstrated to be a powerful tool for control of the mobility of submerged droplets during the microfabrication process. The polymeric patterns are structured at very high levels of organization and exhibit well-established transport-surface property relationships, considered basics for any types of advanced biotechnologies.

  13. Arresting Strategy Based on Dynamic Criminal Networks Changing over Time

    Directory of Open Access Journals (Sweden)

    Junqing Yuan

    2013-01-01

    Full Text Available We investigate a sequence of dynamic criminal networks on a time series based on the dynamic network analysis (DNA. According to the change of networks’ structure, networks’ variation trend is analyzed to forecast its future structure. Finally, an optimal arresting time and priority list are designed based on our analysis. Better results can be expected than that based on social network analysis (SNA.

  14. Analysis of risk factors for schizophrenia with two different case definitions: a nationwide register-based external validation study.

    Science.gov (United States)

    Sørensen, Holger J; Larsen, Janne T; Mors, Ole; Nordentoft, Merete; Mortensen, Preben B; Petersen, Liselotte

    2015-03-01

    Different case definitions of schizophrenia have been used in register based research. However, no previous study has externally validated two different case definitions of schizophrenia against a wide range of risk factors for schizophrenia. We investigated hazard ratios (HRs) for a wide range of risk factors for ICD-10 DCR schizophrenia using a nationwide Danish sample of 2,772,144 residents born in 1955-1997. We compared one contact only (OCO) (the case definition of schizophrenia used in Danish register based studies) with two or more contacts (TMC) (a case definition of at least 2 inpatient contacts with schizophrenia). During the follow-up, the OCO definition included 15,074 and the TMC 7562 cases; i.e. half as many. The TMC case definition appeared to select for a worse illness course. A wide range of risk factors were uniformly associated with both case definitions and only slightly higher risk estimates were found for the TMC definition. Choosing at least 2 inpatient contacts with schizophrenia (TMC) instead of the currently used case definition would result in almost similar risk estimates for many well-established risk factors. However, this would also introduce selection and include considerably fewer cases and reduce power of e.g. genetic studies based on register-diagnosed cases only. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Fundamentals of structural dynamics

    CERN Document Server

    Craig, Roy R

    2006-01-01

    From theory and fundamentals to the latest advances in computational and experimental modal analysis, this is the definitive, updated reference on structural dynamics.This edition updates Professor Craig's classic introduction to structural dynamics, which has been an invaluable resource for practicing engineers and a textbook for undergraduate and graduate courses in vibrations and/or structural dynamics. Along with comprehensive coverage of structural dynamics fundamentals, finite-element-based computational methods, and dynamic testing methods, this Second Edition includes new and e

  16. High dynamic range image acquisition based on multiplex cameras

    Science.gov (United States)

    Zeng, Hairui; Sun, Huayan; Zhang, Tinghua

    2018-03-01

    High dynamic image is an important technology of photoelectric information acquisition, providing higher dynamic range and more image details, and it can better reflect the real environment, light and color information. Currently, the method of high dynamic range image synthesis based on different exposure image sequences cannot adapt to the dynamic scene. It fails to overcome the effects of moving targets, resulting in the phenomenon of ghost. Therefore, a new high dynamic range image acquisition method based on multiplex cameras system was proposed. Firstly, different exposure images sequences were captured with the camera array, using the method of derivative optical flow based on color gradient to get the deviation between images, and aligned the images. Then, the high dynamic range image fusion weighting function was established by combination of inverse camera response function and deviation between images, and was applied to generated a high dynamic range image. The experiments show that the proposed method can effectively obtain high dynamic images in dynamic scene, and achieves good results.

  17. Dynamics-based sequential memory: Winnerless competition of patterns

    International Nuclear Information System (INIS)

    Seliger, Philip; Tsimring, Lev S.; Rabinovich, Mikhail I.

    2003-01-01

    We introduce a biologically motivated dynamical principle of sequential memory which is based on winnerless competition (WLC) of event images. This mechanism is implemented in a two-layer neural model of sequential spatial memory. We present the learning dynamics which leads to the formation of a WLC network. After learning, the system is capable of associative retrieval of prerecorded sequences of patterns

  18. Likelihood-based Dynamic Factor Analysis for Measurement and Forecasting

    NARCIS (Netherlands)

    Jungbacker, B.M.J.P.; Koopman, S.J.

    2015-01-01

    We present new results for the likelihood-based analysis of the dynamic factor model. The latent factors are modelled by linear dynamic stochastic processes. The idiosyncratic disturbance series are specified as autoregressive processes with mutually correlated innovations. The new results lead to

  19. Dynamic market behaviour of autonomous network based power systems

    NARCIS (Netherlands)

    Jokic, A.; Wittebol, E.H.M.; Bosch, van den P.P.J.

    2006-01-01

    Dynamic models of real-time markets are important since they lead to additional insights of the behavior and stability of power system markets. The main topic of this paper is the analysis of real-time market dynamics in a novel power system structure that is based on the concept of autonomous

  20. A dynamic usage based perspective on L2 writing

    NARCIS (Netherlands)

    Verspoor, M.H.; Schmid, M.S.; Xu, X.

    The goal of this study was to explore the contribution that a dynamic usage based (DUB) perspective can bring to the establishment of objective measures to assess L2 learners' written texts and at the same time to gain insight into the dynamic process of language development. Four hundred and thirty

  1. The dynamics of a usage-based approach

    NARCIS (Netherlands)

    Verspoor, Marjolijn; Daems, Jocelyn; Zenner, Eline; Heylen, Kris; Speelman, Dirk; Cuyckens, Hubert

    2015-01-01

    This contribution seeks to connect usage based linguistics with dynamic systems theory, in particular as applied by Edelman (1989) and Thelen and Smith (1994). Edelman’s dynamic biological system starts off with a few simple sub-systems (perception, action, value), all of which interacting with each

  2. Proposal for a definition of lifelong premature ejaculation based on epidemiological stopwatch data.

    Science.gov (United States)

    Waldinger, Marcel D; Zwinderman, Aeilko H; Olivier, Berend; Schweitzer, Dave H

    2005-07-01

    Consensus on a definition of premature ejaculation has not yet been reached because of debates based on subjective authority opinions and nonstandardized assessment methods to measure ejaculation time and ejaculation control. To provide a definition for lifelong premature ejaculation that is based on epidemiological evidence including the neurobiological and psychological approach. We used the 0.5 and 2.5 percentiles as accepted standards of disease definition in a skewed distribution. We applied these percentiles in a stopwatch-determined intravaginal ejaculation latency time (IELT) distribution of 491 nonselected men from five different countries. The practical consequences of 0.5% and 2.5% cutoff points for disease definition were taken into consideration by reviewing current knowledge of feelings of control and satisfaction in relation to ejaculatory performance of the general male population. Literature arguments to be used in a proposed consensus on a definition of premature ejaculation. The stopwatch-determined IELT distribution is positively skewed. The 0.5 percentile equates to an IELT of 0.9 minute and the 2.5 percentile an IELT of 1.3 minutes. However, there are no available data in the literature on feelings of control or satisfaction in relation to ejaculatory latency time in the general male population. Random male cohort studies are needed to end all speculation on this subject. Exact stopwatch time assessment of IELT in a multinational study led us to propose that all men with an IELT of less than 1 minute (belonging to the 0.5 percentile) have "definite" premature ejaculation, while men with IELTs between 1 and 1.5 minutes (between 0.5 and 2.5 percentile) have "probable" premature ejaculation. Severity of premature ejaculation (nonsymptomatic, mild, moderate, severe) should be defined in terms of associated psychological problems. We define lifelong premature ejaculation as a neurobiological dysfunction with an unacceptable increase of risk to

  3. Thermosphere-ionosphere-mesosphere energetics and dynamics (TIMED). The TIMED mission and science program report of the science definition team. Volume 1: Executive summary

    Science.gov (United States)

    1991-01-01

    A Science Definition Team was established in December 1990 by the Space Physics Division, NASA, to develop a satellite program to conduct research on the energetics, dynamics, and chemistry of the mesosphere and lower thermosphere/ionosphere. This two-volume publication describes the TIMED (Thermosphere-Ionosphere-Mesosphere, Energetics and Dynamics) mission and associated science program. The report outlines the scientific objectives of the mission, the program requirements, and the approach towards meeting these requirements.

  4. A Dynamic Travel Time Estimation Model Based on Connected Vehicles

    Directory of Open Access Journals (Sweden)

    Daxin Tian

    2015-01-01

    Full Text Available With advances in connected vehicle technology, dynamic vehicle route guidance models gradually become indispensable equipment for drivers. Traditional route guidance models are designed to direct a vehicle along the shortest path from the origin to the destination without considering the dynamic traffic information. In this paper a dynamic travel time estimation model is presented which can collect and distribute traffic data based on the connected vehicles. To estimate the real-time travel time more accurately, a road link dynamic dividing algorithm is proposed. The efficiency of the model is confirmed by simulations, and the experiment results prove the effectiveness of the travel time estimation method.

  5. Simulation-based decision support framework for dynamic ambulance redeployment in Singapore.

    Science.gov (United States)

    Lam, Sean Shao Wei; Ng, Clarence Boon Liang; Nguyen, Francis Ngoc Hoang Long; Ng, Yih Yng; Ong, Marcus Eng Hock

    2017-10-01

    Dynamic ambulance redeployment policies tend to introduce much more flexibilities in improving ambulance resource allocation by capitalizing on the definite geospatial-temporal variations in ambulance demand patterns over the time-of-the-day and day-of-the-week effects. A novel modelling framework based on the Approximate Dynamic Programming (ADP) approach leveraging on a Discrete Events Simulation (DES) model for dynamic ambulance redeployment in Singapore is proposed in this paper. The study was based on the Singapore's national Emergency Medical Services (EMS) system. Based on a dataset comprising 216,973 valid incidents over a continuous two-years study period from 1 January 2011-31 December 2012, a DES model for the EMS system was developed. An ADP model based on linear value function approximations was then evaluated using the DES model via the temporal difference (TD) learning family of algorithms. The objective of the ADP model is to derive approximate optimal dynamic redeployment policies based on the primary outcome of ambulance coverage. Considering an 8min response time threshold, an estimated 5% reduction in the proportion of calls that cannot be reached within the threshold (equivalent to approximately 8000 dispatches) was observed from the computational experiments. The study also revealed that the redeployment policies which are restricted within the same operational division could potentially result in a more promising response time performance. Furthermore, the best policy involved the combination of redeploying ambulances whenever they are released from service and that of relocating ambulances that are idle in bases. This study demonstrated the successful application of an approximate modelling framework based on ADP that leverages upon a detailed DES model of the Singapore's EMS system to generate approximate optimal dynamic redeployment plans. Various policies and scenarios relevant to the Singapore EMS system were evaluated. Copyright © 2017

  6. Ground-based measurements of ionospheric dynamics

    Science.gov (United States)

    Kouba, Daniel; Chum, Jaroslav

    2018-05-01

    Different methods are used to research and monitor the ionospheric dynamics using ground measurements: Digisonde Drift Measurements (DDM) and Continuous Doppler Sounding (CDS). For the first time, we present comparison between both methods on specific examples. Both methods provide information about the vertical drift velocity component. The DDM provides more information about the drift velocity vector and detected reflection points. However, the method is limited by the relatively low time resolution. In contrast, the strength of CDS is its high time resolution. The discussed methods can be used for real-time monitoring of medium scale travelling ionospheric disturbances. We conclude that it is advantageous to use both methods simultaneously if possible. The CDS is then applied for the disturbance detection and analysis, and the DDM is applied for the reflection height control.

  7. An evidence-based unified definition of lifelong and acquired premature ejaculation

    DEFF Research Database (Denmark)

    Serefoglu, Ege Can; McMahon, Chris G; Waldinger, Marcel D

    2014-01-01

    INTRODUCTION: The International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation developed the first evidence-based definition for lifelong premature ejaculation (PE) in 2007 and concluded that there were insufficient published objective data...... appear to share the dimensions of short ejaculatory latency, reduced or absent perceived ejaculatory control, and the presence of negative personal consequences. Men with acquired PE are older, have higher incidences of erectile dysfunction, comorbid disease, and cardiovascular risk factors, and have...... as a male sexual dysfunction characterized by (i) ejaculation that always or nearly always occurs prior to or within about 1 minute of vaginal penetration from the first sexual experience (lifelong PE) or a clinically significant and bothersome reduction in latency time, often to about 3 minutes or less...

  8. An HVS-based location-sensitive definition of mutual information between two images

    Science.gov (United States)

    Zhu, Haijun; Wu, Huayi

    2006-10-01

    Quantitative measure of image information amount is of great importance in many image processing applications, e.g. image compression and image registration. Many commonly used metrics are defined mathematically. However, the ultimate consumers of images are human observers in most situations, thus such measures without consideration of internal mechanism of human visual system (HVS) may not be appropriate. This paper proposes an improved definition of mutual information between two images based on the visual information which is actually perceived by human beings in different subbands of image. This definition is both sensitive to the pixels' spatial location and correlates well with human perceptual feeling than mutual information purely calculated by pixels' grayscale value. Experimental results on images with different noises and JPEG&JPEG2000 compressed images are also given.

  9. Acute respiratory infection case definitions for young children: a systematic review of community-based epidemiologic studies in South Asia.

    Science.gov (United States)

    Roth, Daniel E; Gaffey, Michelle F; Smith-Romero, Evelyn; Fitzpatrick, Tiffany; Morris, Shaun K

    2015-12-01

    To explore the variability in childhood acute respiratory infection case definitions for research in low-income settings where there is limited access to laboratory or radiologic investigations. We conducted a systematic review of community-based, longitudinal studies in South Asia published from January 1990 to August 2013, in which childhood acute respiratory infection outcomes were reported. Case definitions were classified by their label (e.g. pneumonia, acute lower respiratory infection) and clinical content 'signatures' (array of clinical features that would be always present, conditionally present or always absent among cases). Case definition heterogeneity was primarily assessed by the number of unique case definitions overall and by label. We also compared case definition-specific acute respiratory infection incidence rates for studies reporting incidence rates for multiple case definitions. In 56 eligible studies, we found 124 acute respiratory infection case definitions. Of 90 case definitions for which clinical content was explicitly defined, 66 (73%) were unique. There was a high degree of content heterogeneity among case definitions with the same label, and some content signatures were assigned multiple labels. Within studies for which incidence rates were reported for multiple case definitions, variation in content was always associated with a change in incidence rate, even when the content differed by a single clinical feature. There has been a wide variability in case definition label and content combinations to define acute upper and lower respiratory infections in children in community-based studies in South Asia over the past two decades. These inconsistencies have important implications for the synthesis and translation of knowledge regarding the prevention and treatment of childhood acute respiratory infection. © 2015 John Wiley & Sons Ltd.

  10. Parameterizing Coefficients of a POD-Based Dynamical System

    Science.gov (United States)

    Kalb, Virginia L.

    2010-01-01

    A method of parameterizing the coefficients of a dynamical system based of a proper orthogonal decomposition (POD) representing the flow dynamics of a viscous fluid has been introduced. (A brief description of POD is presented in the immediately preceding article.) The present parameterization method is intended to enable construction of the dynamical system to accurately represent the temporal evolution of the flow dynamics over a range of Reynolds numbers. The need for this or a similar method arises as follows: A procedure that includes direct numerical simulation followed by POD, followed by Galerkin projection to a dynamical system has been proven to enable representation of flow dynamics by a low-dimensional model at the Reynolds number of the simulation. However, a more difficult task is to obtain models that are valid over a range of Reynolds numbers. Extrapolation of low-dimensional models by use of straightforward Reynolds-number-based parameter continuation has proven to be inadequate for successful prediction of flows. A key part of the problem of constructing a dynamical system to accurately represent the temporal evolution of the flow dynamics over a range of Reynolds numbers is the problem of understanding and providing for the variation of the coefficients of the dynamical system with the Reynolds number. Prior methods do not enable capture of temporal dynamics over ranges of Reynolds numbers in low-dimensional models, and are not even satisfactory when large numbers of modes are used. The basic idea of the present method is to solve the problem through a suitable parameterization of the coefficients of the dynamical system. The parameterization computations involve utilization of the transfer of kinetic energy between modes as a function of Reynolds number. The thus-parameterized dynamical system accurately predicts the flow dynamics and is applicable to a range of flow problems in the dynamical regime around the Hopf bifurcation. Parameter

  11. Experimental Research of Crosscorrelation-Based Virtual Dynamic Flowmeter

    International Nuclear Information System (INIS)

    Jiang, W L; Sun, H M; Niu, H F; Gao, M

    2006-01-01

    An innovated method for measuring dynamic flow is put forward, and a virtual dynamic flowmeter is established. Basing on the principle of pressure pulse containing the flow information, for the dynamic laminar flow, by means of collecting the pressure signals at two points at interval of L and processing them with crosscorrelation calculation, then the transit time is gained, consequently the average flow rate can be got. This calculation is prosecuted repeatedly according to a certain time step length, thus the average flow rates in each time slice can be acquired. If the step length is decreased to zero, the piecewise average flow rate is approximate to the instant dynamic flow. In order to calibrate the virtual dynamic flowmeter, the unloaded servo cylinder was used for the contrasting experiment. The accuracy and validity of this approach has been proved

  12. Gradient-based optimization in nonlinear structural dynamics

    DEFF Research Database (Denmark)

    Dou, Suguang

    The intrinsic nonlinearity of mechanical structures can give rise to rich nonlinear dynamics. Recently, nonlinear dynamics of micro-mechanical structures have contributed to developing new Micro-Electro-Mechanical Systems (MEMS), for example, atomic force microscope, passive frequency divider......, frequency stabilization, and disk resonator gyroscope. For advanced design of these structures, it is of considerable value to extend current optimization in linear structural dynamics into nonlinear structural dynamics. In this thesis, we present a framework for modelling, analysis, characterization......, and optimization of nonlinear structural dynamics. In the modelling, nonlinear finite elements are used. In the analysis, nonlinear frequency response and nonlinear normal modes are calculated based on a harmonic balance method with higher-order harmonics. In the characterization, nonlinear modal coupling...

  13. Dynamic Evolution Model Based on Social Network Services

    Science.gov (United States)

    Xiong, Xi; Gou, Zhi-Jian; Zhang, Shi-Bin; Zhao, Wen

    2013-11-01

    Based on the analysis of evolutionary characteristics of public opinion in social networking services (SNS), in the paper we propose a dynamic evolution model, in which opinions are coupled with topology. This model shows the clustering phenomenon of opinions in dynamic network evolution. The simulation results show that the model can fit the data from a social network site. The dynamic evolution of networks accelerates the opinion, separation and aggregation. The scale and the number of clusters are influenced by confidence limit and rewiring probability. Dynamic changes of the topology reduce the number of isolated nodes, while the increased confidence limit allows nodes to communicate more sufficiently. The two effects make the distribution of opinion more neutral. The dynamic evolution of networks generates central clusters with high connectivity and high betweenness, which make it difficult to control public opinions in SNS.

  14. Interactive definition of transfer functions in volume rendering based on image markers

    International Nuclear Information System (INIS)

    Teistler, Michael; Nowinski, Wieslaw L.; Breiman, Richard S.; Liong, Sauw Ming; Ho, Liang Yoong; Shahab, Atif

    2007-01-01

    Objectives A user interface for transfer function (TF) definition in volume rendering (VR) was developed that allows the user to intuitively assign color and opacity to the original image intensities. This software may surpass solutions currently deployed in clinical practice by simplifying the use of TFs beyond predefined settings that are not always applicable. Materials and methods The TF definition is usually a cumbersome task that requires the user to manipulate graphical representations of the TF (e.g. trapezoids). A new method that allows the user to place markers at points of interest directly on CT and MRI images or orthogonal reformations was developed based on two-dimensional region growing and a few user-definable marker-related parameters. For each user defined image marker, a segment of the transfer function is computed. The resulting TF can also be applied to the slice image views. Results were judged subjectively. Results Each individualized TF can be defined interactively in a few simple steps. For every user interaction, immediate visual feedback is given. Clinicians who tested the application appreciated being able to directly work on familiar slice images to generate the desired 3D views. Conclusion Interactive TF definition can increase the actual utility of VR, help to understand the role of the TF with its variations, and increase the acceptance of VR as a clinical tool. (orig.)

  15. A review of marine anthropogenic CO2 definitions: introducing a thermodynamic approach based on observations

    International Nuclear Information System (INIS)

    Friis, Karsten

    2006-01-01

    A review of existing methods that define anthropogenic CO 2 as deduced from total inorganic carbon is presented. A refined approach to define anthropogenic CO 2 is introduced that has a stronger thermodynamic orientation than current methods, and is based on a back-calculation technique by Chen and Millero and Poisson and Chen. Anthropogenic CO 2 results of the new technique are compared with results from the original technique as well as with results of the technique of Gruber et al. The new technique is furthermore applied to three time-separated data sets in the subpolar North Atlantic and shows consistent results with regard to available data quality and anthropogenic CO 2 quantities. The difference between the new thermodynamic approach and the anthropogenic CO 2 definition of Gruber et al., which is termed mechanistic, is discussed. Here likely changes in the CO 2 solubility pump are a thermodynamic property of this definition, whereas it is a separate phenomenon in the mechanistic definition. The thermodynamic approach is not without caveats, but points to improvements by the synergistic use of model results and those from observations. Future improvements are considered for the initial saturation state of oxygen and CO 2 , at the instant the surface water loses contact with the atmosphere and for variations in the Redfield ratio

  16. Acquisition-based Dynamic Reconfiguration Capabilities

    NARCIS (Netherlands)

    Amiryany Araghy, N.; Huysman, M.H.; de Man, A.P.; Cloodt, M.; Demetriss, V.; Weber, Y.; Kaufmann, R.; Tarba, S.

    2009-01-01

    The success of knowledge acquisitions is dependent upon firm’s ability to integrate knowledge-based resources and thus share knowledge, in order to innovate. Regardless of the increasing number of knowledge acquisitions, however, an understanding of how successful firms direct their knowledge

  17. Fundamental limits on quantum dynamics based on entropy change

    Science.gov (United States)

    Das, Siddhartha; Khatri, Sumeet; Siopsis, George; Wilde, Mark M.

    2018-01-01

    It is well known in the realm of quantum mechanics and information theory that the entropy is non-decreasing for the class of unital physical processes. However, in general, the entropy does not exhibit monotonic behavior. This has restricted the use of entropy change in characterizing evolution processes. Recently, a lower bound on the entropy change was provided in the work of Buscemi, Das, and Wilde [Phys. Rev. A 93(6), 062314 (2016)]. We explore the limit that this bound places on the physical evolution of a quantum system and discuss how these limits can be used as witnesses to characterize quantum dynamics. In particular, we derive a lower limit on the rate of entropy change for memoryless quantum dynamics, and we argue that it provides a witness of non-unitality. This limit on the rate of entropy change leads to definitions of several witnesses for testing memory effects in quantum dynamics. Furthermore, from the aforementioned lower bound on entropy change, we obtain a measure of non-unitarity for unital evolutions.

  18. High-definition video display based on the FPGA and THS8200

    Science.gov (United States)

    Qian, Jia; Sui, Xiubao

    2014-11-01

    This paper presents a high-definition video display solution based on the FPGA and THS8200. THS8200 is a video decoder chip launched by TI company, this chip has three 10-bit DAC channels which can capture video data in both 4:2:2 and 4:4:4 formats, and its data synchronization can be either through the dedicated synchronization signals HSYNC and VSYNC, or extracted from the embedded video stream synchronization information SAV / EAV code. In this paper, we will utilize the address and control signals generated by FPGA to access to the data-storage array, and then the FPGA generates the corresponding digital video signals YCbCr. These signals combined with the synchronization signals HSYNC and VSYNC that are also generated by the FPGA act as the input signals of THS8200. In order to meet the bandwidth requirements of the high-definition TV, we adopt video input in the 4:2:2 format over 2×10-bit interface. THS8200 is needed to be controlled by FPGA with I2C bus to set the internal registers, and as a result, it can generate the synchronous signal that is satisfied with the standard SMPTE and transfer the digital video signals YCbCr into analog video signals YPbPr. Hence, the composite analog output signals YPbPr are consist of image data signal and synchronous signal which are superimposed together inside the chip THS8200. The experimental research indicates that the method presented in this paper is a viable solution for high-definition video display, which conforms to the input requirements of the new high-definition display devices.

  19. A semantic-based method for extracting concept definitions from scientific publications: evaluation in the autism phenotype domain

    OpenAIRE

    Hassanpour, Saeed; O?Connor, Martin J; Das, Amar K

    2013-01-01

    Background A variety of informatics approaches have been developed that use information retrieval, NLP and text-mining techniques to identify biomedical concepts and relations within scientific publications or their sentences. These approaches have not typically addressed the challenge of extracting more complex knowledge such as biomedical definitions. In our efforts to facilitate knowledge acquisition of rule-based definitions of autism phenotypes, we have developed a novel semantic-based t...

  20. Scale-invariant entropy-based theory for dynamic ordering

    International Nuclear Information System (INIS)

    Mahulikar, Shripad P.; Kumari, Priti

    2014-01-01

    Dynamically Ordered self-organized dissipative structure exists in various forms and at different scales. This investigation first introduces the concept of an isolated embedding system, which embeds an open system, e.g., dissipative structure and its mass and/or energy exchange with its surroundings. Thereafter, scale-invariant theoretical analysis is presented using thermodynamic principles for Order creation, existence, and destruction. The sustainability criterion for Order existence based on its structured mass and/or energy interactions with the surroundings is mathematically defined. This criterion forms the basis for the interrelationship of physical parameters during sustained existence of dynamic Order. It is shown that the sufficient condition for dynamic Order existence is approached if its sustainability criterion is met, i.e., its destruction path is blocked. This scale-invariant approach has the potential to unify the physical understanding of universal dynamic ordering based on entropy considerations

  1. Dynamic model based on Bayesian method for energy security assessment

    International Nuclear Information System (INIS)

    Augutis, Juozas; Krikštolaitis, Ričardas; Pečiulytė, Sigita; Žutautaitė, Inga

    2015-01-01

    Highlights: • Methodology for dynamic indicator model construction and forecasting of indicators. • Application of dynamic indicator model for energy system development scenarios. • Expert judgement involvement using Bayesian method. - Abstract: The methodology for the dynamic indicator model construction and forecasting of indicators for the assessment of energy security level is presented in this article. An indicator is a special index, which provides numerical values to important factors for the investigated area. In real life, models of different processes take into account various factors that are time-dependent and dependent on each other. Thus, it is advisable to construct a dynamic model in order to describe these dependences. The energy security indicators are used as factors in the dynamic model. Usually, the values of indicators are obtained from statistical data. The developed dynamic model enables to forecast indicators’ variation taking into account changes in system configuration. The energy system development is usually based on a new object construction. Since the parameters of changes of the new system are not exactly known, information about their influences on indicators could not be involved in the model by deterministic methods. Thus, dynamic indicators’ model based on historical data is adjusted by probabilistic model with the influence of new factors on indicators using the Bayesian method

  2. A Novel Image Stream Cipher Based On Dynamic Substitution

    OpenAIRE

    Elsharkawi, A.; El-Sagheer, R. M.; Akah, H.; Taha, H.

    2016-01-01

    Recently, many chaos-based stream cipher algorithms have been developed. Traditional chaos stream cipher is based on XORing a generated secure random number sequence based on chaotic maps (e.g. logistic map, Bernoulli Map, Tent Map etc.) with the original image to get the encrypted image, This type of stream cipher seems to be vulnerable to chosen plaintext attacks. This paper introduces a new stream cipher algorithm based on dynamic substitution box. The new algorithm uses one substitution b...

  3. Construction Worker Fatigue Prediction Model Based on System Dynamic

    OpenAIRE

    Wahyu Adi Tri Joko; Ayu Ratnawinanda Lila

    2017-01-01

    Construction accident can be caused by internal and external factors such as worker fatigue and unsafe project environment. Tight schedule of construction project forcing construction worker to work overtime in long period. This situation leads to worker fatigue. This paper proposes a model to predict construction worker fatigue based on system dynamic (SD). System dynamic is used to represent correlation among internal and external factors and to simulate level of worker fatigue. To validate...

  4. Thermal behaviour in dynamic recrystallisation. Application for iron base alloys

    International Nuclear Information System (INIS)

    Belkebir, A.; Kobylanski, A.

    1995-01-01

    A constitutive relationship for predicting the flow stress with dynamic recrystallization were proposed. The approach is based on a phenomenological formalism of the law θ-ε where θ correspond to the work-hardening rate at constant strain rate and temperature. The equations proposed were justified by the experimental data collected by hot compression test of low-alloy steels. The model can be used to estimate the critical strain for the onset of dynamic recrystallization. (orig.)

  5. The 2018 Definition of Periprosthetic Hip and Knee Infection: An Evidence-Based and Validated Criteria.

    Science.gov (United States)

    Parvizi, Javad; Tan, Timothy L; Goswami, Karan; Higuera, Carlos; Della Valle, Craig; Chen, Antonia F; Shohat, Noam

    2018-05-01

    The introduction of the Musculoskeletal Infection Society (MSIS) criteria for periprosthetic joint infection (PJI) in 2011 resulted in improvements in diagnostic confidence and research collaboration. The emergence of new diagnostic tests and the lessons we have learned from the past 7 years using the MSIS definition, prompted us to develop an evidence-based and validated updated version of the criteria. This multi-institutional study of patients undergoing revision total joint arthroplasty was conducted at 3 academic centers. For the development of the new diagnostic criteria, PJI and aseptic patient cohorts were stringently defined: PJI cases were defined using only major criteria from the MSIS definition (n = 684) and aseptic cases underwent one-stage revision for a noninfective indication and did not fail within 2 years (n = 820). Serum C-reactive protein (CRP), D-dimer, erythrocyte sedimentation rate were investigated, as well as synovial white blood cell count, polymorphonuclear percentage, leukocyte esterase, alpha-defensin, and synovial CRP. Intraoperative findings included frozen section, presence of purulence, and isolation of a pathogen by culture. A stepwise approach using random forest analysis and multivariate regression was used to generate relative weights for each diagnostic marker. Preoperative and intraoperative definitions were created based on beta coefficients. The new definition was then validated on an external cohort of 222 patients with PJI who subsequently failed with reinfection and 200 aseptic patients. The performance of the new criteria was compared to the established MSIS and the prior International Consensus Meeting definitions. Two positive cultures or the presence of a sinus tract were considered as major criteria and diagnostic of PJI. The calculated weights of an elevated serum CRP (>1 mg/dL), D-dimer (>860 ng/mL), and erythrocyte sedimentation rate (>30 mm/h) were 2, 2, and 1 points, respectively. Furthermore, elevated

  6. Dynamic Strategic Planning in a Professional Knowledge-Based Organization

    Science.gov (United States)

    Olivarius, Niels de Fine; Kousgaard, Marius Brostrom; Reventlow, Susanne; Quelle, Dan Grevelund; Tulinius, Charlotte

    2010-01-01

    Professional, knowledge-based institutions have a particular form of organization and culture that makes special demands on the strategic planning supervised by research administrators and managers. A model for dynamic strategic planning based on a pragmatic utilization of the multitude of strategy models was used in a small university-affiliated…

  7. A Cumulant-based Analysis of Nonlinear Magnetospheric Dynamics

    International Nuclear Information System (INIS)

    Johnson, Jay R.; Wing, Simon

    2004-01-01

    Understanding magnetospheric dynamics and predicting future behavior of the magnetosphere is of great practical interest because it could potentially help to avert catastrophic loss of power and communications. In order to build good predictive models it is necessary to understand the most critical nonlinear dependencies among observed plasma and electromagnetic field variables in the coupled solar wind/magnetosphere system. In this work, we apply a cumulant-based information dynamical measure to characterize the nonlinear dynamics underlying the time evolution of the Dst and Kp geomagnetic indices, given solar wind magnetic field and plasma input. We examine the underlying dynamics of the system, the temporal statistical dependencies, the degree of nonlinearity, and the rate of information loss. We find a significant solar cycle dependence in the underlying dynamics of the system with greater nonlinearity for solar minimum. The cumulant-based approach also has the advantage that it is reliable even in the case of small data sets and therefore it is possible to avoid the assumption of stationarity, which allows for a measure of predictability even when the underlying system dynamics may change character. Evaluations of several leading Kp prediction models indicate that their performances are sub-optimal during active times. We discuss possible improvements of these models based on this nonparametric approach

  8. 77 FR 48207 - Further Definition of “Swap,” “Security-Based Swap,” and “Security-Based Swap Agreement”; Mixed...

    Science.gov (United States)

    2012-08-13

    ... Swaps and Cross-Currency Swaps (c) Interpretation Regarding Foreign Exchange Spot Transactions (d... Exchange Act, 15 U.S.C. 78c(a)(68). This new security-based swap definition also is cross-referenced in new... Securities and Exchange Commission 17 CFR Parts 230, 240 and 241 Further Definition of ``Swap,'' ``Security...

  9. Research on Automotive Dynamic Weighing Method Based on Piezoelectric Sensor

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2017-01-01

    Full Text Available In order to effectively measure the dynamic axle load of vehicles in motion, the dynamic weighing method of vehicles based on piezoelectric sensor was studied. Firstly, the influencing factors of the measurement accuracy in the dynamic weighing process were analyzed systematically, and the impacts of road irregularities and dynamic weighing system vibration on measurement error were discussed. On the basis of the analysis, the arithmetic mean filter method was used in the software algorithm to filter out the periodic interference added in the sensor signal, the most suitable n value was selected to get the better filtering result by simulation comparison. Then, the dynamic axle load calculation model of high speed vehicles was studied deeply, based on the theoretical response curve of the sensor, the dynamic axle load calculation method based on frequency reconstruction was established according to actual measurement signals of sensors and the analysis from time domain and frequency domain, also the least square method was used to realize the identification of temperature correction coefficient. A large amount of data that covered the usual vehicle weighing range was collected by experiment. The results show that the dynamic weighing signal system identification error all controlled within 10% at the same temperature and 60% of the vehicle data error can be controlled within 7%. The temperature correction coefficient and the correction formula at different temperatures ranges are well adapted to ensure that the vehicle temperature error at different temperatures can also be controlled within 10% and 70% of the vehicle data error within 7%. Furthermore, the weighing results remain stable regardless of the speed of the vehicle which meets the requirements for high-speed dynamic weighing.

  10. Discrete event dynamic system (DES)-based modeling for dynamic material flow in the pyroprocess

    International Nuclear Information System (INIS)

    Lee, Hyo Jik; Kim, Kiho; Kim, Ho Dong; Lee, Han Soo

    2011-01-01

    A modeling and simulation methodology was proposed in order to implement the dynamic material flow of the pyroprocess. Since the static mass balance provides the limited information on the material flow, it is hard to predict dynamic behavior according to event. Therefore, a discrete event system (DES)-based model named, PyroFlow, was developed at the Korea Atomic Energy Research Institute (KAERI). PyroFlow is able to calculate dynamic mass balance and also show various dynamic operational results in real time. By using PyroFlow, it is easy to rapidly predict unforeseeable results, such as throughput in unit process, accumulated product in buffer and operation status. As preliminary simulations, bottleneck analyses in the pyroprocess were carried out and consequently it was presented that operation strategy had influence on the productivity of the pyroprocess.

  11. System Dynamics as Model-Based Theory Building

    OpenAIRE

    Schwaninger, Markus; Grösser, Stefan N.

    2008-01-01

    This paper introduces model-based theory building as a feature of system dynamics (SD) with large potential. It presents a systemic approach to actualizing that potential, thereby opening up a new perspective on theory building in the social sciences. The question addressed is if and how SD enables the construction of high-quality theories. This contribution is based on field experiment type projects which have been focused on model-based theory building, specifically the construction of a mi...

  12. Structure-based control of complex networks with nonlinear dynamics.

    Science.gov (United States)

    Zañudo, Jorge Gomez Tejeda; Yang, Gang; Albert, Réka

    2017-07-11

    What can we learn about controlling a system solely from its underlying network structure? Here we adapt a recently developed framework for control of networks governed by a broad class of nonlinear dynamics that includes the major dynamic models of biological, technological, and social processes. This feedback-based framework provides realizable node overrides that steer a system toward any of its natural long-term dynamic behaviors, regardless of the specific functional forms and system parameters. We use this framework on several real networks, identify the topological characteristics that underlie the predicted node overrides, and compare its predictions to those of structural controllability in control theory. Finally, we demonstrate this framework's applicability in dynamic models of gene regulatory networks and identify nodes whose override is necessary for control in the general case but not in specific model instances.

  13. DYNAMICS BASED CONTROL OF A SKID STEERING MOBILE ROBOT

    Directory of Open Access Journals (Sweden)

    Osama Elshazly

    2016-06-01

    Full Text Available In this paper, development of a reduced order, augmented dynamics-drive model that combines both the dynamics and drive subsystems of the skid steering mobile robot (SSMR is presented. A Linear Quadratic Regulator (LQR control algorithm with feed-forward compensation of the disturbances part included in the reduced order augmented dynamics-drive model is designed. The proposed controller has many advantages such as its simplicity in terms of design and implementation in comparison with complex nonlinear control schemes that are usually designed for this system. Moreover, the good performance is also provided by the controller for the SSMR comparable with a nonlinear controller based on the inverse dynamics which depends on the availability of an accurate model describing the system. Simulation results illustrate the effectiveness and enhancement provided by the proposed controller.

  14. Exploratory analysis regarding the domain definitions for computer based analytical models

    Science.gov (United States)

    Raicu, A.; Oanta, E.; Barhalescu, M.

    2017-08-01

    Our previous computer based studies dedicated to structural problems using analytical methods defined the composite cross section of a beam as a result of Boolean operations with so-called ‘simple’ shapes. Using generalisations, in the class of the ‘simple’ shapes were included areas bounded by curves approximated using spline functions and areas approximated as polygons. However, particular definitions lead to particular solutions. In order to ascend above the actual limitations, we conceived a general definition of the cross sections that are considered now calculus domains consisting of several subdomains. The according set of input data use complex parameterizations. This new vision allows us to naturally assign a general number of attributes to the subdomains. In this way there may be modelled new phenomena that use map-wise information, such as the metal alloys equilibrium diagrams. The hierarchy of the input data text files that use the comma-separated-value format and their structure are also presented and discussed in the paper. This new approach allows us to reuse the concepts and part of the data processing software instruments already developed. The according software to be subsequently developed will be modularised and generalised in order to be used in the upcoming projects that require rapid development of computer based models.

  15. A conceptual definition of vocational rehabilitation based on the ICF: building a shared global model.

    Science.gov (United States)

    Escorpizo, Reuben; Reneman, Michiel F; Ekholm, Jan; Fritz, Julie; Krupa, Terry; Marnetoft, Sven-Uno; Maroun, Claude E; Guzman, Julietta Rodriguez; Suzuki, Yoshiko; Stucki, Gerold; Chan, Chetwyn C H

    2011-06-01

    The International Classification of Functioning, Disability and Health (ICF) is a conceptual framework and classification system by the World Health Organization (WHO) to understand functioning. The objective of this discussion paper is to offer a conceptual definition for vocational rehabilitation (VR) based on the ICF. We presented the ICF as a model for application in VR and the rationale for the integration of the ICF. We also briefly reviewed other work disability models. Five essential elements of foci were found towards a conceptual definition of VR: an engagement or re-engagement to work, along a work continuum, involved health conditions or events leading to work disability, patient-centered and evidence-based, and is multi-professional or multidisciplinary. VR refers to a multi-professional approach that is provided to individuals of working age with health-related impairments, limitations, or restrictions with work functioning and whose primary aim is to optimize work participation. We propose that the ICF and VR interface be explored further using empirical and qualitative works and encouraging stakeholders' participation.

  16. A definition of unknown parent groups based on bull usage patterns across herds.

    Science.gov (United States)

    Bouquet, A; Renand, G; Phocas, F

    2011-03-01

    In genetic evaluations, the definition of unknown parent groups (UPG) is usually based on time periods, selection path and flows of foreign founders. The definition of UPG may be more complex for populations presenting genetic heterogeneity due to both, large national expansion and coexistence of artificial insemination (AI) and natural service (NS). A UPG definition method accounting for beef bull flows was proposed and applied to the French Charolais cattle population. It assumed that, at a given time period, unknown parents belonged to the same UPG when their progeny were bred in herds that used bulls with similar origins (birth region and reproduction way). Thus, the birth period, region and AI rate of a herd were pointed out to be the three criteria reflecting genetic disparities at the national level in a beef cattle population. To deal with regional genetic disparities, 14 regions were identified using a factorial approach combining principal component analysis and Ward clustering. The selection nucleus of the French cattle population was dispersed over three main breeding areas. Flows of NS bulls were mainly carried out within each breeding area. On the contrary, the use and the selection of AI bulls were based on a national pool of candidates. Within a time period, herds of different regions were clustered together when they used bulls coming from the same origin and with an estimated difference of genetic level lower than 20% of genetic standard deviation (σg) for calf muscle and skeleton scores (SS) at weaning. This led to the definition of 16 UPG of sires, which were validated as robust and relevant in a sire model, meaning numerically stable and corresponding to distinct genetic subpopulations. The UPG genetic levels were estimated for muscle and SS under sire and animal models. Whatever the trait, differences between bull UPG estimates within a time period could reach 0.5 σg across regions. For a given time period, bull UPG estimates for muscle and

  17. Goal Definition

    DEFF Research Database (Denmark)

    Bjørn, Anders; Laurent, Alexis; Owsianiak, Mikołaj

    2018-01-01

    The goal definition is the first phase of an LCA and determines the purpose of a study in detail. This chapter teaches how to perform the six aspects of a goal definition: (1) Intended applications of the results, (2) Limitations due to methodological choices, (3) Decision context and reasons...... for carrying out the study, (4) Target audience , (5) Comparative studies to be disclosed to the public and (6) Commissioner of the study and other influential actors. The instructions address both the conduct and reporting of a goal definition and are largely based on the ILCD guidance document (EC...

  18. Agent Based Modeling on Organizational Dynamics of Terrorist Network

    Directory of Open Access Journals (Sweden)

    Bo Li

    2015-01-01

    Full Text Available Modeling organizational dynamics of terrorist network is a critical issue in computational analysis of terrorism research. The first step for effective counterterrorism and strategic intervention is to investigate how the terrorists operate with the relational network and what affects the performance. In this paper, we investigate the organizational dynamics by employing a computational experimentation methodology. The hierarchical cellular network model and the organizational dynamics model are developed for modeling the hybrid relational structure and complex operational processes, respectively. To intuitively elucidate this method, the agent based modeling is used to simulate the terrorist network and test the performance in diverse scenarios. Based on the experimental results, we show how the changes of operational environments affect the development of terrorist organization in terms of its recovery and capacity to perform future tasks. The potential strategies are also discussed, which can be used to restrain the activities of terrorists.

  19. Cultural-based particle swarm for dynamic optimisation problems

    Science.gov (United States)

    Daneshyari, Moayed; Yen, Gary G.

    2012-07-01

    Many practical optimisation problems are with the existence of uncertainties, among which a significant number belong to the dynamic optimisation problem (DOP) category in which the fitness function changes through time. In this study, we propose the cultural-based particle swarm optimisation (PSO) to solve DOP problems. A cultural framework is adopted incorporating the required information from the PSO into five sections of the belief space, namely situational, temporal, domain, normative and spatial knowledge. The stored information will be adopted to detect the changes in the environment and assists response to the change through a diversity-based repulsion among particles and migration among swarms in the population space, and also helps in selecting the leading particles in three different levels, personal, swarm and global levels. Comparison of the proposed heuristics over several difficult dynamic benchmark problems demonstrates the better or equal performance with respect to most of other selected state-of-the-art dynamic PSO heuristics.

  20. Prevalence of depression: Comparisons of different depression definitions in population-based samples of older adults.

    Science.gov (United States)

    Sjöberg, Linnea; Karlsson, Björn; Atti, Anna-Rita; Skoog, Ingmar; Fratiglioni, Laura; Wang, Hui-Xin

    2017-10-15

    Depression prevalence in older adults varies largely across studies, which probably reflects methodological rather than true differences. This study aims to explore whether and to what extent the prevalence of depression varies when using different diagnostic criteria and rating scales, and various samples of older adults. A population-based sample of 3353 individuals aged 60-104 years from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K) were examined in 2001-2004. Point prevalence of depression was estimated by: 1) diagnostic criteria, ICD-10 and DSM-IV-TR/DSM-5; 2) rating scales, MADRS and GDS-15; and 3) self-report. Depression prevalence in sub-samples by dementia status, living place, and socio-demographics were compared. The prevalence of any depression (including all severity grades) was 4.2% (moderate/severe: 1.6%) for ICD-10 and 9.3% (major: 2.1%) for DSM-IV-TR; 10.6% for MADRS and 9.2% for GDS-15; and 9.1% for self-report. Depression prevalence was lower in the dementia-free sample as compared to the total population. Furthermore, having poor physical function, or not having a partner were independently associated with higher depression prevalence, across most of the depression definitions. The response rate was 73.3% and this may have resulted in an underestimation of depression. Depression prevalence was similar across all depression definitions except for ICD-10, showing much lower figures. However, independent of the definition used, depression prevalence varies greatly by dementia status, physical functioning, and marital status. These findings may be useful for clinicians when assessing depression in older adults and for researchers when exploring and comparing depression prevalence across studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. What Is Real-World Data? A Review of Definitions Based on Literature and Stakeholder Interviews.

    Science.gov (United States)

    Makady, Amr; de Boer, Anthonius; Hillege, Hans; Klungel, Olaf; Goettsch, Wim

    Despite increasing recognition of the value of real-world data (RWD), consensus on the definition of RWD is lacking. To review definitions publicly available for RWD to shed light on similarities and differences between them. A literature review and stakeholder interviews were used to compile data from eight groups of stakeholders. Data from documents and interviews were subjected to coding analysis. Definitions identified were classified into four categories: 1) data collected in a non-randomized controlled trial setting, 2) data collected in a non-interventional/non-controlled setting, 3) data collected in a non-experimental setting, and 4) others (i.e., data that do not fit into the other three categories). The frequency of definitions identified per category was recorded. Fifty-three documents and 20 interviews were assessed. Thirty-eight definitions were identified: 20 out of 38 definitions (53%) were category 1 definitions, 9 (24%) were category 2 definitions, 5 (13%) were category 3 definitions, and 4 (11%) were category 4 definitions. Differences were identified between, and within, definition categories. For example, opinions differed on the aspects of intervention with which non-interventional/non-controlled settings should abide. No definitions were provided in two interviews or identified in 33 documents. Most of the definitions defined RWD as data collected in a non-randomized controlled trial setting. A considerable number of definitions, however, diverged from this concept. Moreover, a significant number of authors and stakeholders did not have an official, institutional definition for RWD. Persisting variability in stakeholder definitions of RWD may lead to disparities among different stakeholders when discussing RWD use in decision making. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  2. Systematic review of proposed definitions of nocturnal polyuria and population-based evidence of their diagnostic accuracy.

    Science.gov (United States)

    Olesen, Tine Kold; Denys, Marie-Astrid; Vande Walle, Johan; Everaert, Karel

    2018-02-06

    Background Evidence of diagnostic accuracy for proposed definitions of nocturnal polyuria is currently unclear. Purpose Systematic review to determine population-based evidence of the diagnostic accuracy of proposed definitions of nocturnal polyuria based on data from frequency-volume charts. Methods Seventeen pre-specified search terms identified 351 unique investigations published from 1990 to 2016 in BIOSIS, Embase, Embase Alerts, International Pharmaceutical Abstract, Medline, and Cochrane. Thirteen original communications were included in this review based on pre-specified exclusion criteria. Data were extracted from each paper regarding subject age, sex, ethnicity, health status, sample size, data collection methods, and diagnostic discrimination of proposed definitions including sensitivity, specificity, positive and negative predictive value. Results The sample size of study cohorts, participant age, sex, ethnicity, and health status varied considerably in 13 studies reporting on the diagnostic performance of seven different definitions of nocturnal polyuria using frequency-volume chart data from 4968 participants. Most study cohorts were small, mono-ethnic, including only Caucasian males aged 50 or higher with primary or secondary polyuria that were compared to a control group of healthy men without nocturia in prospective or retrospective settings. Proposed definitions had poor discriminatory accuracy in evaluations based on data from subjects independent from the original study cohorts with findings being similar regarding the most widely evaluated definition endorsed by ICS. Conclusions Diagnostic performance characteristics for proposed definitions of nocturnal polyuria show poor to modest discrimination and are not based on sufficient level of evidence from representative, multi-ethnic population-based data from both females and males of all adult ages.

  3. Overlapping community detection based on link graph using distance dynamics

    Science.gov (United States)

    Chen, Lei; Zhang, Jing; Cai, Li-Jun

    2018-01-01

    The distance dynamics model was recently proposed to detect the disjoint community of a complex network. To identify the overlapping structure of a network using the distance dynamics model, an overlapping community detection algorithm, called L-Attractor, is proposed in this paper. The process of L-Attractor mainly consists of three phases. In the first phase, L-Attractor transforms the original graph to a link graph (a new edge graph) to assure that one node has multiple distances. In the second phase, using the improved distance dynamics model, a dynamic interaction process is introduced to simulate the distance dynamics (shrink or stretch). Through the dynamic interaction process, all distances converge, and the disjoint community structure of the link graph naturally manifests itself. In the third phase, a recovery method is designed to convert the disjoint community structure of the link graph to the overlapping community structure of the original graph. Extensive experiments are conducted on the LFR benchmark networks as well as real-world networks. Based on the results, our algorithm demonstrates higher accuracy and quality than other state-of-the-art algorithms.

  4. Achieving a Consensual Definition of Phishing Based on a Systematic Review of the Literature

    NARCIS (Netherlands)

    Lastdrager, E.E.H.

    2014-01-01

    Background: Phishing is a widely known phenomenon, but currently lacks a commonly accepted definition. As a result, many studies about phishing use their own definition. The lack of a common definition prevents knowledge accumulation and makes analysing studies or aggregating data about phishing a

  5. Combining heterogeneous features for colonic polyp detection in CTC based on semi-definite programming

    Science.gov (United States)

    Wang, Shijun; Yao, Jianhua; Petrick, Nicholas A.; Summers, Ronald M.

    2009-02-01

    Colon cancer is the second leading cause of cancer-related deaths in the United States. Computed tomographic colonography (CTC) combined with a computer aided detection system provides a feasible combination for improving colonic polyps detection and increasing the use of CTC for colon cancer screening. To distinguish true polyps from false positives, various features extracted from polyp candidates have been proposed. Most of these features try to capture the shape information of polyp candidates or neighborhood knowledge about the surrounding structures (fold, colon wall, etc.). In this paper, we propose a new set of shape descriptors for polyp candidates based on statistical curvature information. These features, called histogram of curvature features, are rotation, translation and scale invariant and can be treated as complementing our existing feature set. Then in order to make full use of the traditional features (defined as group A) and the new features (group B) which are highly heterogeneous, we employed a multiple kernel learning method based on semi-definite programming to identify an optimized classification kernel based on the combined set of features. We did leave-one-patient-out test on a CTC dataset which contained scans from 50 patients (with 90 6-9mm polyp detections). Experimental results show that a support vector machine (SVM) based on the combined feature set and the semi-definite optimization kernel achieved higher FROC performance compared to SVMs using the two groups of features separately. At a false positive per patient rate of 7, the sensitivity on 6-9mm polyps using the combined features improved from 0.78 (Group A) and 0.73 (Group B) to 0.82 (p<=0.01).

  6. Accelerating convergence of molecular dynamics-based structural relaxation

    DEFF Research Database (Denmark)

    Christensen, Asbjørn

    2005-01-01

    We describe strategies to accelerate the terminal stage of molecular dynamics (MD)based relaxation algorithms, where a large fraction of the computational resources are used. First, we analyze the qualitative and quantitative behavior of the QuickMin family of MD relaxation algorithms and explore...

  7. New MPPT algorithm based on hybrid dynamical theory

    KAUST Repository

    Elmetennani, Shahrazed

    2014-11-01

    This paper presents a new maximum power point tracking algorithm based on the hybrid dynamical theory. A multiceli converter has been considered as an adaptation stage for the photovoltaic chain. The proposed algorithm is a hybrid automata switching between eight different operating modes, which has been validated by simulation tests under different working conditions. © 2014 IEEE.

  8. Dynamic Buffer Capacity in Acid-Base Systems.

    Science.gov (United States)

    Michałowska-Kaczmarczyk, Anna M; Michałowski, Tadeusz

    The generalized concept of 'dynamic' buffer capacity β V is related to electrolytic systems of different complexity where acid-base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton-Robinson buffers, taken as examples.

  9. Dynamic Frames Based Verification Method for Concurrent Java Programs

    NARCIS (Netherlands)

    Mostowski, Wojciech

    2016-01-01

    In this paper we discuss a verification method for concurrent Java programs based on the concept of dynamic frames. We build on our earlier work that proposes a new, symbolic permission system for concurrent reasoning and we provide the following new contributions. First, we describe our approach

  10. Exploring consumption- and asset-based poverty dynamics in Ethiopia

    African Journals Online (AJOL)

    This paper examines the dynamics of wellbeing in Ethiopia by assessing changes in poverty status based on consumption and asset ownership. Using panel data from the first two waves of the Ethiopia Socioeconomic Survey (ESS), we discover that although the cross-sectional poverty remains relatively unchanged ...

  11. Dynamic Buffer Capacity in Acid?Base Systems

    OpenAIRE

    Micha?owska-Kaczmarczyk, Anna M.; Micha?owski, Tadeusz

    2015-01-01

    The generalized concept of ?dynamic? buffer capacity ? V is related to electrolytic systems of different complexity where acid?base equilibria are involved. The resulting formulas are presented in a uniform and consistent form. The detailed calculations are related to two Britton?Robinson buffers, taken as examples.

  12. Individual based model of slug population and spatial dynamics

    NARCIS (Netherlands)

    Choi, Y.H.; Bohan, D.A.; Potting, R.P.J.; Semenov, M.A.; Glen, D.M.

    2006-01-01

    The slug, Deroceras reticulatum, is one of the most important pests of agricultural and horticultural crops in UK and Europe. In this paper, a spatially explicit individual based model (IbM) is developed to study the dynamics of a population of D. reticulatum. The IbM establishes a virtual field

  13. New MPPT algorithm based on hybrid dynamical theory

    KAUST Repository

    Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem; Benmansour, K.; Boucherit, M. S.; Tadjine, M.

    2014-01-01

    This paper presents a new maximum power point tracking algorithm based on the hybrid dynamical theory. A multiceli converter has been considered as an adaptation stage for the photovoltaic chain. The proposed algorithm is a hybrid automata switching between eight different operating modes, which has been validated by simulation tests under different working conditions. © 2014 IEEE.

  14. Foreign Language Instruction from a dynamic usage-based (DUB) perspective

    NARCIS (Netherlands)

    Rousse-Malpat, Audrey; Verspoor, Marjolijn; Tyler, Andrea E.; Ortega, Lourdes; Uno, Mariko; Park, Hae In

    2018-01-01

    In this chapter we combine ideas of usage based linguistics and dynamic systems theory to argue that language is a dynamic usage based system and L2 learning is a dynamic process. Two teaching approaches based on Dynamic Usage-based (DUB) principles with mainly implicit attention to form--a movie

  15. Computer Vision Based Measurement of Wildfire Smoke Dynamics

    Directory of Open Access Journals (Sweden)

    BUGARIC, M.

    2015-02-01

    Full Text Available This article presents a novel method for measurement of wildfire smoke dynamics based on computer vision and augmented reality techniques. The aspect of smoke dynamics is an important feature in video smoke detection that could distinguish smoke from visually similar phenomena. However, most of the existing smoke detection systems are not capable of measuring the real-world size of the detected smoke regions. Using computer vision and GIS-based augmented reality, we measure the real dimensions of smoke plumes, and observe the change in size over time. The measurements are performed on offline video data with known camera parameters and location. The observed data is analyzed in order to create a classifier that could be used to eliminate certain categories of false alarms induced by phenomena with different dynamics than smoke. We carried out an offline evaluation where we measured the improvement in the detection process achieved using the proposed smoke dynamics characteristics. The results show a significant increase in algorithm performance, especially in terms of reducing false alarms rate. From this it follows that the proposed method for measurement of smoke dynamics could be used to improve existing smoke detection algorithms, or taken into account when designing new ones.

  16. Next Generation Extended Lagrangian Quantum-based Molecular Dynamics

    Science.gov (United States)

    Negre, Christian

    2017-06-01

    A new framework for extended Lagrangian first-principles molecular dynamics simulations is presented, which overcomes shortcomings of regular, direct Born-Oppenheimer molecular dynamics, while maintaining important advantages of the unified extended Lagrangian formulation of density functional theory pioneered by Car and Parrinello three decades ago. The new framework allows, for the first time, energy conserving, linear-scaling Born-Oppenheimer molecular dynamics simulations, which is necessary to study larger and more realistic systems over longer simulation times than previously possible. Expensive, self-consinstent-field optimizations are avoided and normal integration time steps of regular, direct Born-Oppenheimer molecular dynamics can be used. Linear scaling electronic structure theory is presented using a graph-based approach that is ideal for parallel calculations on hybrid computer platforms. For the first time, quantum based Born-Oppenheimer molecular dynamics simulation is becoming a practically feasible approach in simulations of +100,000 atoms-representing a competitive alternative to classical polarizable force field methods. In collaboration with: Anders Niklasson, Los Alamos National Laboratory.

  17. A thermodynamically based definition of fast verses slow heating in secondary explosives

    Science.gov (United States)

    Henson, Bryan; Smilowitz, Laura

    2013-06-01

    The thermal response of energetic materials is often categorized according to the rate of heating as either fast or slow, e.g. slow cook-off. Such categorizations have most often followed some operational rationale, without a material based definition. We have spent several years demonstrating that for the energetic material octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) a single mechanism of thermal response reproduces times to ignition independent of rate or means of heating over the entire range of thermal response. HMX is unique in that bulk melting is rarely observed in either thermal ignition or combustion. We have recently discovered a means of expressing this mechanism for HMX in a reduced form applicable to many secondary explosives. We will show that with this mechanism a natural definition of fast versus slow rates of heating emerges, related to the rate of melting, and we use this to illustrate why HMX does not exhibit melting, and why a number of other secondary explosives do, and require the two separate categories.

  18. Ontology-based composition and matching for dynamic service coordination

    OpenAIRE

    Pahl, Claus; Gacitua-Decar, Veronica; Wang, MingXue; Yapa Bandara, Kosala

    2011-01-01

    Service engineering needs to address integration problems allowing services to collaborate and coordinate. The need to address dynamic automated changes - caused by on-demand environments and changing requirements - can be addressed through service coordination based on ontology-based composition and matching techniques. Our solution to composition and matching utilises a service coordination space that acts as a passive infrastructure for collaboration. We discuss the information models an...

  19. A framework of region-based dynamic image fusion

    Institute of Scientific and Technical Information of China (English)

    WANG Zhong-hua; QIN Zheng; LIU Yu

    2007-01-01

    A new framework of region-based dynamic image fusion is proposed. First, the technique of target detection is applied to dynamic images (image sequences) to segment images into different targets and background regions. Then different fusion rules are employed in different regions so that the target information is preserved as much as possible. In addition, steerable non-separable wavelet frame transform is used in the process of multi-resolution analysis, so the system achieves favorable characters of orientation and invariant shift. Compared with other image fusion methods, experimental results showed that the proposed method has better capabilities of target recognition and preserves clear background information.

  20. Dynamic contact angle of water-based titanium oxide nanofluid

    Science.gov (United States)

    2013-01-01

    This paper presents an investigation into spreading dynamics and dynamic contact angle of TiO2-deionized water nanofluids. Two mechanisms of energy dissipation, (1) contact line friction and (2) wedge film viscosity, govern the dynamics of contact line motion. The primary stage of spreading has the contact line friction as the dominant dissipative mechanism. At the secondary stage of spreading, the wedge film viscosity is the dominant dissipative mechanism. A theoretical model based on combination of molecular kinetic theory and hydrodynamic theory which incorporates non-Newtonian viscosity of solutions is used. The model agreement with experimental data is reasonable. Complex interparticle interactions, local pinning of the contact line, and variations in solid–liquid interfacial tension are attributed to errors. PMID:23759071

  1. A fast dynamic mode in rare earth based glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, L. Z.; Xue, R. J.; Zhu, Z. G.; Wang, W. H.; Bai, H. Y., E-mail: hybai@iphy.ac.cn [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Ngai, K. L. [Dipartimento di Fisica, Università di Pisa, Largo B. Pontecorvo 3, I-56127 Pisa (Italy)

    2016-05-28

    Metallic glasses (MGs) usually exhibit only slow β-relaxation peak, and the signature of the fast dynamic is challenging to be observed experimentally in MGs. We report a general and unusual fast dynamic mode in a series of rare earth based MGs manifested as a distinct fast β′-relaxation peak in addition to slow β-relaxation and α-relaxation peaks. We show that the activation energy of the fast β′-relaxation is about 12RT{sub g} and is equivalent to the activation of localized flow event. The coupling of these dynamic processes as well as their relationship with glass transition and structural heterogeneity is discussed.

  2. A Reconfigurable Logic Cell Based on a Simple Dynamical System

    Directory of Open Access Journals (Sweden)

    Lixiang Li

    2013-01-01

    Full Text Available This paper introduces a new scheme to achieve a dynamic logic gate which can be adjusted flexibly to obtain different logic functions by adjusting specific parameters of a dynamical system. Based on graphical tools and the threshold mechanism, the distribution of different logic gates is studied, and a transformation method between different logics is given. Analyzing the performance of the dynamical system in the presence of noise, we discover that it is resistant to system noise. Moreover, we find some part of the system can be considered as a leaky integrator which has been already widely applied in engineering. Finally, we provide a proof-of-principle hardware implementation of the proposed scheme to illustrate its effectiveness. With the proposed scheme in hand, it is convenient to build the flexible, robust, and general purpose computing devices such as various network coding routers, communication encoders or decoders, and reconfigurable computer chips.

  3. Scope Definition

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikołaj; Laurent, Alexis

    2018-01-01

    The scope definition is the second phase of an LCA. It determines what product systems are to be assessed and how this assessment should take place. This chapter teaches how to perform a scope definition. First, important terminology and key concepts of LCA are introduced. Then, the nine items...... making up a scope definition are elaborately explained: (1) Deliverables. (2) Object of assessment, (3) LCI modelling framework and handling of multifunctional processes, (4) System boundaries and completeness requirements, (5) Representativeness of LCI data, (6) Preparing the basis for the impact...... assessment, (7) Special requirements for system comparisons, (8) Critical review needs and (9) Planning reporting of results. The instructions relate both to the performance and reporting of a scope definition and are largely based on ILCD....

  4. Dynamic Garment Simulation based on Hybrid Bounding Volume Hierarchy

    Directory of Open Access Journals (Sweden)

    Zhu Dongyong

    2016-12-01

    Full Text Available In order to solve the computing speed and efficiency problem of existing dynamic clothing simulation, this paper presents a dynamic garment simulation based on a hybrid bounding volume hierarchy. It firstly uses MCASG graph theory to do the primary segmentation for a given three-dimensional human body model. And then it applies K-means cluster to do the secondary segmentation to collect the human body’s upper arms, lower arms, upper legs, lower legs, trunk, hip and woman’s chest as the elementary units of dynamic clothing simulation. According to different shapes of these elementary units, it chooses the closest and most efficient hybrid bounding box to specify these units, such as cylinder bounding box and elliptic cylinder bounding box. During the process of constructing these bounding boxes, it uses the least squares method and slices of the human body to get the related parameters. This approach makes it possible to use the least amount of bounding boxes to create close collision detection regions for the appearance of the human body. A spring-mass model based on a triangular mesh of the clothing model is finally constructed for dynamic simulation. The simulation result shows the feasibility and superiority of the method described.

  5. Neural network based adaptive control for nonlinear dynamic regimes

    Science.gov (United States)

    Shin, Yoonghyun

    Adaptive control designs using neural networks (NNs) based on dynamic inversion are investigated for aerospace vehicles which are operated at highly nonlinear dynamic regimes. NNs play a key role as the principal element of adaptation to approximately cancel the effect of inversion error, which subsequently improves robustness to parametric uncertainty and unmodeled dynamics in nonlinear regimes. An adaptive control scheme previously named 'composite model reference adaptive control' is further developed so that it can be applied to multi-input multi-output output feedback dynamic inversion. It can have adaptive elements in both the dynamic compensator (linear controller) part and/or in the conventional adaptive controller part, also utilizing state estimation information for NN adaptation. This methodology has more flexibility and thus hopefully greater potential than conventional adaptive designs for adaptive flight control in highly nonlinear flight regimes. The stability of the control system is proved through Lyapunov theorems, and validated with simulations. The control designs in this thesis also include the use of 'pseudo-control hedging' techniques which are introduced to prevent the NNs from attempting to adapt to various actuation nonlinearities such as actuator position and rate saturations. Control allocation is introduced for the case of redundant control effectors including thrust vectoring nozzles. A thorough comparison study of conventional and NN-based adaptive designs for a system under a limit cycle, wing-rock, is included in this research, and the NN-based adaptive control designs demonstrate their performances for two highly maneuverable aerial vehicles, NASA F-15 ACTIVE and FQM-117B unmanned aerial vehicle (UAV), operated under various nonlinearities and uncertainties.

  6. An evidence-based unified definition of lifelong and acquired premature ejaculation : report of the second International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation

    NARCIS (Netherlands)

    Serefoglu, Ege Can; McMahon, Chris G; Waldinger, Marcel D|info:eu-repo/dai/nl/163958564; Althof, Stanley E; Shindel, Alan; Adaikan, Ganesh; Becher, Edgardo F; Dean, John; Giuliano, Francois; Hellstrom, Wayne J G; Giraldi, Annamaria; Glina, Sidney; Incrocci, Luca; Jannini, Emmanuele; McCabe, Marita; Parish, Sharon; Rowland, David; Segraves, R Taylor; Sharlip, Ira; Torres, Luiz Otavio

    INTRODUCTION: The International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation developed the first evidence-based definition for lifelong premature ejaculation (PE) in 2007 and concluded that there were insufficient published objective data at that

  7. An evidence-based unified definition of lifelong and acquired premature ejaculation : report of the second international society for sexual medicine ad hoc committee for the definition of premature ejaculation

    NARCIS (Netherlands)

    Serefoglu, Ege Can; McMahon, Chris G; Waldinger, Marcel D|info:eu-repo/dai/nl/163958564; Althof, Stanley E; Shindel, Alan; Adaikan, Ganesh; Becher, Edgardo F; Dean, John; Giuliano, Francois; Hellstrom, Wayne Jg; Giraldi, Annamaria; Glina, Sidney; Incrocci, Luca; Jannini, Emmanuele; McCabe, Marita; Parish, Sharon; Rowland, David; Segraves, R Taylor; Sharlip, Ira; Torres, Luiz Otavio

    INTRODUCTION: The International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation developed the first evidence-based definition for lifelong premature ejaculation (PE) in 2007 and concluded that there were insufficient published objective data at that

  8. Dynamically Authorized Role-Based Access Control for Grid Applications

    Institute of Scientific and Technical Information of China (English)

    YAO Hanbing; HU Heping; LU Zhengding; LI Ruixuan

    2006-01-01

    Grid computing is concerned with the sharing and coordinated use of diverse resources in distributed "virtual organizations". The heterogeneous, dynamic and multi-domain nature of these environments makes challenging security issues that demand new technical approaches. Despite the recent advances in access control approaches applicable to Grid computing, there remain issues that impede the development of effective access control models for Grid applications. Among them there are the lack of context-based models for access control, and reliance on identity or capability-based access control schemes. An access control scheme that resolve these issues is presented, and a dynamically authorized role-based access control (D-RBAC) model extending the RBAC with context constraints is proposed. The D-RABC mechanisms dynamically grant permissions to users based on a set of contextual information collected from the system and user's environments, while retaining the advantages of RBAC model. The implementation architecture of D-RBAC for the Grid application is also described.

  9. Dynamic reasoning in a knowledge-based system

    Science.gov (United States)

    Rao, Anand S.; Foo, Norman Y.

    1988-01-01

    Any space based system, whether it is a robot arm assembling parts in space or an onboard system monitoring the space station, has to react to changes which cannot be foreseen. As a result, apart from having domain-specific knowledge as in current expert systems, a space based AI system should also have general principles of change. This paper presents a modal logic which can not only represent change but also reason with it. Three primitive operations, expansion, contraction and revision are introduced and axioms which specify how the knowledge base should change when the external world changes are also specified. Accordingly the notion of dynamic reasoning is introduced, which unlike the existing forms of reasoning, provide general principles of change. Dynamic reasoning is based on two main principles, namely minimize change and maximize coherence. A possible-world semantics which incorporates the above two principles is also discussed. The paper concludes by discussing how the dynamic reasoning system can be used to specify actions and hence form an integral part of an autonomous reasoning and planning system.

  10. Prediction-based dynamic load-sharing heuristics

    Science.gov (United States)

    Goswami, Kumar K.; Devarakonda, Murthy; Iyer, Ravishankar K.

    1993-01-01

    The authors present dynamic load-sharing heuristics that use predicted resource requirements of processes to manage workloads in a distributed system. A previously developed statistical pattern-recognition method is employed for resource prediction. While nonprediction-based heuristics depend on a rapidly changing system status, the new heuristics depend on slowly changing program resource usage patterns. Furthermore, prediction-based heuristics can be more effective since they use future requirements rather than just the current system state. Four prediction-based heuristics, two centralized and two distributed, are presented. Using trace driven simulations, they are compared against random scheduling and two effective nonprediction based heuristics. Results show that the prediction-based centralized heuristics achieve up to 30 percent better response times than the nonprediction centralized heuristic, and that the prediction-based distributed heuristics achieve up to 50 percent improvements relative to their nonprediction counterpart.

  11. Tensor-based Dictionary Learning for Dynamic Tomographic Reconstruction

    Science.gov (United States)

    Tan, Shengqi; Zhang, Yanbo; Wang, Ge; Mou, Xuanqin; Cao, Guohua; Wu, Zhifang; Yu, Hengyong

    2015-01-01

    In dynamic computed tomography (CT) reconstruction, the data acquisition speed limits the spatio-temporal resolution. Recently, compressed sensing theory has been instrumental in improving CT reconstruction from far few-view projections. In this paper, we present an adaptive method to train a tensor-based spatio-temporal dictionary for sparse representation of an image sequence during the reconstruction process. The correlations among atoms and across phases are considered to capture the characteristics of an object. The reconstruction problem is solved by the alternating direction method of multipliers. To recover fine or sharp structures such as edges, the nonlocal total variation is incorporated into the algorithmic framework. Preclinical examples including a sheep lung perfusion study and a dynamic mouse cardiac imaging demonstrate that the proposed approach outperforms the vectorized dictionary-based CT reconstruction in the case of few-view reconstruction. PMID:25779991

  12. Tensor-based dictionary learning for dynamic tomographic reconstruction

    International Nuclear Information System (INIS)

    Tan, Shengqi; Wu, Zhifang; Zhang, Yanbo; Mou, Xuanqin; Wang, Ge; Cao, Guohua; Yu, Hengyong

    2015-01-01

    In dynamic computed tomography (CT) reconstruction, the data acquisition speed limits the spatio-temporal resolution. Recently, compressed sensing theory has been instrumental in improving CT reconstruction from far few-view projections. In this paper, we present an adaptive method to train a tensor-based spatio-temporal dictionary for sparse representation of an image sequence during the reconstruction process. The correlations among atoms and across phases are considered to capture the characteristics of an object. The reconstruction problem is solved by the alternating direction method of multipliers. To recover fine or sharp structures such as edges, the nonlocal total variation is incorporated into the algorithmic framework. Preclinical examples including a sheep lung perfusion study and a dynamic mouse cardiac imaging demonstrate that the proposed approach outperforms the vectorized dictionary-based CT reconstruction in the case of few-view reconstruction. (paper)

  13. Prediction-based Dynamic Energy Management in Wireless Sensor Networks

    Science.gov (United States)

    Wang, Xue; Ma, Jun-Jie; Wang, Sheng; Bi, Dao-Wei

    2007-01-01

    Energy consumption is a critical constraint in wireless sensor networks. Focusing on the energy efficiency problem of wireless sensor networks, this paper proposes a method of prediction-based dynamic energy management. A particle filter was introduced to predict a target state, which was adopted to awaken wireless sensor nodes so that their sleep time was prolonged. With the distributed computing capability of nodes, an optimization approach of distributed genetic algorithm and simulated annealing was proposed to minimize the energy consumption of measurement. Considering the application of target tracking, we implemented target position prediction, node sleep scheduling and optimal sensing node selection. Moreover, a routing scheme of forwarding nodes was presented to achieve extra energy conservation. Experimental results of target tracking verified that energy-efficiency is enhanced by prediction-based dynamic energy management.

  14. Node-Dependence-Based Dynamic Incentive Algorithm in Opportunistic Networks

    Directory of Open Access Journals (Sweden)

    Ruiyun Yu

    2014-01-01

    Full Text Available Opportunistic networks lack end-to-end paths between source nodes and destination nodes, so the communications are mainly carried out by the “store-carry-forward” strategy. Selfish behaviors of rejecting packet relay requests will severely worsen the network performance. Incentive is an efficient way to reduce selfish behaviors and hence improves the reliability and robustness of the networks. In this paper, we propose the node-dependence-based dynamic gaming incentive (NDI algorithm, which exploits the dynamic repeated gaming to motivate nodes relaying packets for other nodes. The NDI algorithm presents a mechanism of tolerating selfish behaviors of nodes. Reward and punishment methods are also designed based on the node dependence degree. Simulation results show that the NDI algorithm is effective in increasing the delivery ratio and decreasing average latency when there are a lot of selfish nodes in the opportunistic networks.

  15. Offset Free Tracking Predictive Control Based on Dynamic PLS Framework

    Directory of Open Access Journals (Sweden)

    Jin Xin

    2017-10-01

    Full Text Available This paper develops an offset free tracking model predictive control based on a dynamic partial least square (PLS framework. First, state space model is used as the inner model of PLS to describe the dynamic system, where subspace identification method is used to identify the inner model. Based on the obtained model, multiple independent model predictive control (MPC controllers are designed. Due to the decoupling character of PLS, these controllers are running separately, which is suitable for distributed control framework. In addition, the increment of inner model output is considered in the cost function of MPC, which involves integral action in the controller. Hence, the offset free tracking performance is guaranteed. The results of an industry background simulation demonstrate the effectiveness of proposed method.

  16. Prediction-based Dynamic Energy Management in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Dao-Wei Bi

    2007-03-01

    Full Text Available Energy consumption is a critical constraint in wireless sensor networks. Focusing on the energy efficiency problem of wireless sensor networks, this paper proposes a method of prediction-based dynamic energy management. A particle filter was introduced to predict a target state, which was adopted to awaken wireless sensor nodes so that their sleep time was prolonged. With the distributed computing capability of nodes, an optimization approach of distributed genetic algorithm and simulated annealing was proposed to minimize the energy consumption of measurement. Considering the application of target tracking, we implemented target position prediction, node sleep scheduling and optimal sensing node selection. Moreover, a routing scheme of forwarding nodes was presented to achieve extra energy conservation. Experimental results of target tracking verified that energy-efficiency is enhanced by prediction-based dynamic energy management.

  17. Distance learning, problem based learning and dynamic knowledge networks.

    Science.gov (United States)

    Giani, U; Martone, P

    1998-06-01

    This paper is an attempt to develop a distance learning model grounded upon a strict integration of problem based learning (PBL), dynamic knowledge networks (DKN) and web tools, such as hypermedia documents, synchronous and asynchronous communication facilities, etc. The main objective is to develop a theory of distance learning based upon the idea that learning is a highly dynamic cognitive process aimed at connecting different concepts in a network of mutually supporting concepts. Moreover, this process is supposed to be the result of a social interaction that has to be facilitated by the web. The model was tested by creating a virtual classroom of medical and nursing students and activating a learning session on the concept of knowledge representation in health sciences.

  18. Systems and methods for interpolation-based dynamic programming

    KAUST Repository

    Rockwood, Alyn

    2013-01-03

    Embodiments of systems and methods for interpolation-based dynamic programming. In one embodiment, the method includes receiving an object function and a set of constraints associated with the objective function. The method may also include identifying a solution on the objective function corresponding to intersections of the constraints. Additionally, the method may include generating an interpolated surface that is in constant contact with the solution. The method may also include generating a vector field in response to the interpolated surface.

  19. Systems and methods for interpolation-based dynamic programming

    KAUST Repository

    Rockwood, Alyn

    2013-01-01

    Embodiments of systems and methods for interpolation-based dynamic programming. In one embodiment, the method includes receiving an object function and a set of constraints associated with the objective function. The method may also include identifying a solution on the objective function corresponding to intersections of the constraints. Additionally, the method may include generating an interpolated surface that is in constant contact with the solution. The method may also include generating a vector field in response to the interpolated surface.

  20. Optimization of dynamic envelope measurement system for high speed train based on monocular vision

    Science.gov (United States)

    Wu, Bin; Liu, Changjie; Fu, Luhua; Wang, Zhong

    2018-01-01

    The definition of dynamic envelope curve is the maximum limit outline caused by various adverse effects during the running process of the train. It is an important base of making railway boundaries. At present, the measurement work of dynamic envelope curve of high-speed vehicle is mainly achieved by the way of binocular vision. There are some problems of the present measuring system like poor portability, complicated process and high cost. A new measurement system based on the monocular vision measurement theory and the analysis on the test environment is designed and the measurement system parameters, the calibration of camera with wide field of view, the calibration of the laser plane are designed and optimized in this paper. The accuracy has been verified to be up to 2mm by repeated tests and experimental data analysis. The feasibility and the adaptability of the measurement system is validated. There are some advantages of the system like lower cost, a simpler measurement and data processing process, more reliable data. And the system needs no matching algorithm.

  1. Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems.

    Science.gov (United States)

    Adams, Alyssa; Zenil, Hector; Davies, Paul C W; Walker, Sara Imari

    2017-04-20

    Open-ended evolution (OEE) is relevant to a variety of biological, artificial and technological systems, but has been challenging to reproduce in silico. Most theoretical efforts focus on key aspects of open-ended evolution as it appears in biology. We recast the problem as a more general one in dynamical systems theory, providing simple criteria for open-ended evolution based on two hallmark features: unbounded evolution and innovation. We define unbounded evolution as patterns that are non-repeating within the expected Poincare recurrence time of an isolated system, and innovation as trajectories not observed in isolated systems. As a case study, we implement novel variants of cellular automata (CA) where the update rules are allowed to vary with time in three alternative ways. Each is capable of generating conditions for open-ended evolution, but vary in their ability to do so. We find that state-dependent dynamics, regarded as a hallmark of life, statistically out-performs other candidate mechanisms, and is the only mechanism to produce open-ended evolution in a scalable manner, essential to the notion of ongoing evolution. This analysis suggests a new framework for unifying mechanisms for generating OEE with features distinctive to life and its artifacts, with broad applicability to biological and artificial systems.

  2. An Evidence-Based Unified Definition of Lifelong and Acquired Premature Ejaculation: Report of the Second International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation

    Directory of Open Access Journals (Sweden)

    Ege Can Serefoglu, MD

    2014-06-01

    Conclusion: The ISSM unified definition of lifelong and acquired PE represents the first evidence-based definition for these conditions. This definition will enable researchers to design methodologically rigorous studies to improve our understanding of acquired PE. Serefoglu EC, McMahon CG, Waldinger MD, Althof SE, Shindel A, Adaikan G, Becher EF, Dean J, Giuliano F, Hellstrom WJG, Giraldi A, Glina S, Incrocci L, Jannini E, McCabe M, Parish S, Rowland D, Segraves RT, Sharlip I, and Torres LO. An evidence-based unified definition of lifelong and acquired premature ejaculation: Report of the second International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation. Sex Med 2014;2:41–59.

  3. Vehicle Unsteady Dynamics Characteristics Based on Tire and Road Features

    Directory of Open Access Journals (Sweden)

    Bin Ma

    2013-01-01

    Full Text Available During automotive related accidents, tire and road play an important role in vehicle unsteady dynamics as they have a significant impact on the sliding friction. The calculation of the rubber viscoelastic energy loss modulus and the true contact area model is improved based on the true contact area and the rubber viscoelastic theory. A 10 DOF full vehicle dynamic model in consideration of the kinetic sliding friction coefficient which has good accuracy and reality is developed. The stability test is carried out to evaluate the effectiveness of the model, and the simulation test is done in MATLAB to analyze the impact of tire feature and road self-affine characteristics on the sport utility vehicle (SUV unsteady dynamics under different weights. The findings show that it is a great significance to analyze the SUV dynamics equipped with different tire on different roads, which may provide useful insights into solving the explicit-implicit features of tire prints in systematically and designing active safety systems.

  4. Dynamic managerial capability of technology-based international new ventures

    DEFF Research Database (Denmark)

    Altshuler, Liliya

    2014-01-01

    case study of a technology-based INV conducted over the period of 3.5 years, starting 8 years into the firm’s history. This unique design has enabled close observation of the specific events and challenges the firm has been facing after its initial success, and of the aspects in the firm’s management...... to resource availability. The study takes the dynamic capability perspective and focuses on INVs’ management, which are seen as founders and builders of the processes, rules and structures that lay the basis for long-term competitive advantage for such firms. Based on the findings, specific aspects...

  5. What Is Real-World Data? A Review of Definitions Based on Literature and Stakeholder Interviews

    NARCIS (Netherlands)

    Makady, Amr; de Boer, Anthonius; Hillege, Hans; Klungel, Olaf; Goettsch, Wim

    2017-01-01

    Background: Despite increasing recognition of the value of real-world data (RWD), consensus on the definition of RWD is lacking.  Objectives: To review definitions publicly available for RWD to shed light on similarities and differences between them.  Methods: A literature review and stakeholder

  6. Standardization of whole slide image morphologic assessment with definition of a new application: Digital slide dynamic morphometry

    Directory of Open Access Journals (Sweden)

    Giacomo Puppa

    2011-01-01

    Full Text Available Background: In histopathology, the quantitative assessment of various morphologic features is based on methods originally conceived on specific areas observed through the microscope used. Failure to reproduce the same reference field of view using a different microscope will change the score assessed. Visualization of a digital slide on a screen through a dedicated viewer allows selection of the magnification. However, the field of view is rectangular, unlike the circular field of optical microscopy. In addition, the size of the selected area is not evident, and must be calculated. Materials and Methods: A digital slide morphometric system was conceived to reproduce the various methods published for assessing tumor budding in colorectal cancer. Eighteen international experts in colorectal cancer were invited to participate in a web-based study by assessing tumor budding with five different methods in 100 digital slides. Results: The specific areas to be tested by each method were marked by colored circles. The areas were grouped in a target-like pattern and then saved as an .xml file. When a digital slide was opened, the .xml file was imported in order to perform the measurements. Since the morphometric tool is composed of layers that can be freely moved on top of the digital slide, the technique was named digital slide dynamic morphometry. Twelve investigators completed the task, the majority of them performing the multiple evaluations of each of the cases in less than 12 minutes. Conclusions: Digital slide dynamic morphometry has various potential applications and might be a useful tool for the assessment of histologic parameters originally conceived for optical microscopy that need to be quantified.

  7. An evidence-based definition of lifelong premature ejaculation: Report of the International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation

    DEFF Research Database (Denmark)

    McMahon, C.G.; Althof, S.E.; Waldinger, M.D.

    2008-01-01

    Introduction. The medical literature contains several definitions of premature ejaculation (PE). The most commonly quoted definition, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revision, and other definitions of PE are all auth...

  8. Quantification of cardiorespiratory interactions based on joint symbolic dynamics.

    Science.gov (United States)

    Kabir, Muammar M; Saint, David A; Nalivaiko, Eugene; Abbott, Derek; Voss, Andreas; Baumert, Mathias

    2011-10-01

    Cardiac and respiratory rhythms are highly nonlinear and nonstationary. As a result traditional time-domain techniques are often inadequate to characterize their complex dynamics. In this article, we introduce a novel technique to investigate the interactions between R-R intervals and respiratory phases based on their joint symbolic dynamics. To evaluate the technique, electrocardiograms (ECG) and respiratory signals were recorded in 13 healthy subjects in different body postures during spontaneous and controlled breathing. Herein, the R-R time series were extracted from ECG and respiratory phases were obtained from abdomen impedance belts using the Hilbert transform. Both time series were transformed into ternary symbol vectors based on the changes between two successive R-R intervals or respiratory phases. Subsequently, words of different symbol lengths were formed and the correspondence between the two series of words was determined to quantify the interaction between cardiac and respiratory cycles. To validate our results, respiratory sinus arrhythmia (RSA) was further studied using the phase-averaged characterization of the RSA pattern. The percentage of similarity of the sequence of symbols, between the respective words of the two series determined by joint symbolic dynamics, was significantly reduced in the upright position compared to the supine position (26.4 ± 4.7 vs. 20.5 ± 5.4%, p cardiorespiratory interaction that is highly sensitive to the effects of orthostatic challenge.

  9. A Dynamic Attitude Measurement System Based on LINS

    Directory of Open Access Journals (Sweden)

    Hanzhou Li

    2014-08-01

    Full Text Available A dynamic attitude measurement system (DAMS is developed based on a laser inertial navigation system (LINS. Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG. The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min.

  10. A Dynamic Attitude Measurement System Based on LINS

    Science.gov (United States)

    Li, Hanzhou; Pan, Quan; Wang, Xiaoxu; Zhang, Juanni; Li, Jiang; Jiang, Xiangjun

    2014-01-01

    A dynamic attitude measurement system (DAMS) is developed based on a laser inertial navigation system (LINS). Three factors of the dynamic attitude measurement error using LINS are analyzed: dynamic error, time synchronization and phase lag. An optimal coning errors compensation algorithm is used to reduce coning errors, and two-axis wobbling verification experiments are presented in the paper. The tests indicate that the attitude accuracy is improved 2-fold by the algorithm. In order to decrease coning errors further, the attitude updating frequency is improved from 200 Hz to 2000 Hz. At the same time, a novel finite impulse response (FIR) filter with three notches is designed to filter the dither frequency of the ring laser gyro (RLG). The comparison tests suggest that the new filter is five times more effective than the old one. The paper indicates that phase-frequency characteristics of FIR filter and first-order holder of navigation computer constitute the main sources of phase lag in LINS. A formula to calculate the LINS attitude phase lag is introduced in the paper. The expressions of dynamic attitude errors induced by phase lag are derived. The paper proposes a novel synchronization mechanism that is able to simultaneously solve the problems of dynamic test synchronization and phase compensation. A single-axis turntable and a laser interferometer are applied to verify the synchronization mechanism. The experiments results show that the theoretically calculated values of phase lag and attitude error induced by phase lag can both match perfectly with testing data. The block diagram of DAMS and physical photos are presented in the paper. The final experiments demonstrate that the real-time attitude measurement accuracy of DAMS can reach up to 20″ (1σ) and the synchronization error is less than 0.2 ms on the condition of three axes wobbling for 10 min. PMID:25177802

  11. A new ODE tumor growth modeling based on tumor population dynamics

    International Nuclear Information System (INIS)

    Oroji, Amin; Omar, Mohd bin; Yarahmadian, Shantia

    2015-01-01

    In this paper a new mathematical model for the population of tumor growth treated by radiation is proposed. The cells dynamics population in each state and the dynamics of whole tumor population are studied. Furthermore, a new definition of tumor lifespan is presented. Finally, the effects of two main parameters, treatment parameter (q), and repair mechanism parameter (r) on tumor lifespan are probed, and it is showed that the change in treatment parameter (q) highly affects the tumor lifespan

  12. A new ODE tumor growth modeling based on tumor population dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Oroji, Amin; Omar, Mohd bin [Institute of Mathematical Sciences, Faculty of Science University of Malaya, 50603 Kuala Lumpur, Malaysia amin.oroji@siswa.um.edu.my, mohd@um.edu.my (Malaysia); Yarahmadian, Shantia [Mathematics Department Mississippi State University, USA Syarahmadian@math.msstate.edu (United States)

    2015-10-22

    In this paper a new mathematical model for the population of tumor growth treated by radiation is proposed. The cells dynamics population in each state and the dynamics of whole tumor population are studied. Furthermore, a new definition of tumor lifespan is presented. Finally, the effects of two main parameters, treatment parameter (q), and repair mechanism parameter (r) on tumor lifespan are probed, and it is showed that the change in treatment parameter (q) highly affects the tumor lifespan.

  13. Ultrafast Dynamic Pressure Sensors Based on Graphene Hybrid Structure.

    Science.gov (United States)

    Liu, Shanbiao; Wu, Xing; Zhang, Dongdong; Guo, Congwei; Wang, Peng; Hu, Weida; Li, Xinming; Zhou, Xiaofeng; Xu, Hejun; Luo, Chen; Zhang, Jian; Chu, Junhao

    2017-07-19

    Mechanical flexible electronic skin has been focused on sensing various physical parameters, such as pressure and temperature. The studies of material design and array-accessible devices are the building blocks of strain sensors for subtle pressure sensing. Here, we report a new and facile preparation of a graphene hybrid structure with an ultrafast dynamic pressure response. Graphene oxide nanosheets are used as a surfactant to prevent graphene restacking in aqueous solution. This graphene hybrid structure exhibits a frequency-independent pressure resistive sensing property. Exceeding natural skin, such pressure sensors, can provide transient responses from static up to 10 000 Hz dynamic frequencies. Integrated by the controlling system, the array-accessible sensors can manipulate a robot arm and self-rectify the temperature of a heating blanket. This may pave a path toward the future application of graphene-based wearable electronics.

  14. Construction Worker Fatigue Prediction Model Based on System Dynamic

    Directory of Open Access Journals (Sweden)

    Wahyu Adi Tri Joko

    2017-01-01

    Full Text Available Construction accident can be caused by internal and external factors such as worker fatigue and unsafe project environment. Tight schedule of construction project forcing construction worker to work overtime in long period. This situation leads to worker fatigue. This paper proposes a model to predict construction worker fatigue based on system dynamic (SD. System dynamic is used to represent correlation among internal and external factors and to simulate level of worker fatigue. To validate the model, 93 construction workers whom worked in a high rise building construction projects, were used as case study. The result shows that excessive workload, working elevation and age, are the main factors lead to construction worker fatigue. Simulation result also shows that these factors can increase worker fatigue level to 21.2% times compared to normal condition. Beside predicting worker fatigue level this model can also be used as early warning system to prevent construction worker accident

  15. Dynamical theory of subconstituents based on ternary algebras

    International Nuclear Information System (INIS)

    Bars, I.; Guenaydin, M.

    1980-01-01

    We propose a dynamical theory of possible fundamental constituents of matter. Our scheme is based on (super) ternary algebras which are building blocks of Lie (super) algebras. Elementary fields, called ''ternons,'' are associated with the elements of a (super) ternary algebra. Effective gauge bosons, ''quarks,'' and ''leptons'' are constructed as composite fields from ternons. We propose two- and four-dimensional (super) ternon theories whose structures are closely related to CP/sub N/ and Yang-Mills theories and their supersymmetric extensions. We conjecture that at large distances (low energies) the ternon theories dynamically produce effective gauge theories and thus may be capable of explaining the present particle-physics phenomenology. Such a scenario is valid in two dimensions

  16. Dynamic Sensor Management Algorithm Based on Improved Efficacy Function

    Directory of Open Access Journals (Sweden)

    TANG Shujuan

    2016-01-01

    Full Text Available A dynamic sensor management algorithm based on improved efficacy function is proposed to solve the multi-target and multi-sensory management problem. The tracking task precision requirements (TPR, target priority and sensor use cost were considered to establish the efficacy function by weighted sum the normalized value of the three factors. The dynamic sensor management algorithm was accomplished through control the diversities of the desired covariance matrix (DCM and the filtering covariance matrix (FCM. The DCM was preassigned in terms of TPR and the FCM was obtained by the centralized sequential Kalman filtering algorithm. The simulation results prove that the proposed method could meet the requirements of desired tracking precision and adjust sensor selection according to target priority and cost of sensor source usage. This makes sensor management scheme more reasonable and effective.

  17. Monte Carlo-based simulation of dynamic jaws tomotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S. [Department of Molecular Imaging, Radiotherapy and Oncology, Universite Catholique de Louvain, 54 Avenue Hippocrate, 1200 Brussels, Belgium and Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); TomoTherapy Inc., 1240 Deming Way, Madison, Wisconsin 53717 (United States); 21 Century Oncology., 1240 D' onofrio, Madison, Wisconsin 53719 (United States); TomoTherapy Inc., 1240 Deming Way, Madison, Wisconsin 53717 and Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53705 (United States); Department of Radiotherapy and Oncology, Universite Catholique de Louvain, St-Luc University Hospital, 10 Avenue Hippocrate, 1200 Brussels (Belgium)

    2011-09-15

    Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is

  18. Monte Carlo-based simulation of dynamic jaws tomotherapy

    International Nuclear Information System (INIS)

    Sterpin, E.; Chen, Y.; Chen, Q.; Lu, W.; Mackie, T. R.; Vynckier, S.

    2011-01-01

    Purpose: Original TomoTherapy systems may involve a trade-off between conformity and treatment speed, the user being limited to three slice widths (1.0, 2.5, and 5.0 cm). This could be overcome by allowing the jaws to define arbitrary fields, including very small slice widths (<1 cm), which are challenging for a beam model. The aim of this work was to incorporate the dynamic jaws feature into a Monte Carlo (MC) model called TomoPen, based on the MC code PENELOPE, previously validated for the original TomoTherapy system. Methods: To keep the general structure of TomoPen and its efficiency, the simulation strategy introduces several techniques: (1) weight modifiers to account for any jaw settings using only the 5 cm phase-space file; (2) a simplified MC based model called FastStatic to compute the modifiers faster than pure MC; (3) actual simulation of dynamic jaws. Weight modifiers computed with both FastStatic and pure MC were compared. Dynamic jaws simulations were compared with the convolution/superposition (C/S) of TomoTherapy in the ''cheese'' phantom for a plan with two targets longitudinally separated by a gap of 3 cm. Optimization was performed in two modes: asymmetric jaws-constant couch speed (''running start stop,'' RSS) and symmetric jaws-variable couch speed (''symmetric running start stop,'' SRSS). Measurements with EDR2 films were also performed for RSS for the formal validation of TomoPen with dynamic jaws. Results: Weight modifiers computed with FastStatic were equivalent to pure MC within statistical uncertainties (0.5% for three standard deviations). Excellent agreement was achieved between TomoPen and C/S for both asymmetric jaw opening/constant couch speed and symmetric jaw opening/variable couch speed, with deviations well within 2%/2 mm. For RSS procedure, agreement between C/S and measurements was within 2%/2 mm for 95% of the points and 3%/3 mm for 98% of the points, where dose is greater than 30% of the prescription dose (gamma analysis

  19. Dynamical Languages

    Science.gov (United States)

    Xie, Huimin

    The following sections are included: * Definition of Dynamical Languages * Distinct Excluded Blocks * Definition and Properties * L and L″ in Chomsky Hierarchy * A Natural Equivalence Relation * Symbolic Flows * Symbolic Flows and Dynamical Languages * Subshifts of Finite Type * Sofic Systems * Graphs and Dynamical Languages * Graphs and Shannon-Graphs * Transitive Languages * Topological Entropy

  20. Dynamic Hydrological Modeling in Drylands with TRMM Based Rainfall

    Directory of Open Access Journals (Sweden)

    Elena Tarnavsky

    2013-12-01

    Full Text Available This paper introduces and evaluates DryMOD, a dynamic water balance model of the key hydrological process in drylands that is based on free, public-domain datasets. The rainfall model of DryMOD makes optimal use of spatially disaggregated Tropical Rainfall Measuring Mission (TRMM datasets to simulate hourly rainfall intensities at a spatial resolution of 1-km. Regional-scale applications of the model in seasonal catchments in Tunisia and Senegal characterize runoff and soil moisture distribution and dynamics in response to varying rainfall data inputs and soil properties. The results highlight the need for hourly-based rainfall simulation and for correcting TRMM 3B42 rainfall intensities for the fractional cover of rainfall (FCR. Without FCR correction and disaggregation to 1 km, TRMM 3B42 based rainfall intensities are too low to generate surface runoff and to induce substantial changes to soil moisture storage. The outcomes from the sensitivity analysis show that topsoil porosity is the most important soil property for simulation of runoff and soil moisture. Thus, we demonstrate the benefit of hydrological investigations at a scale, for which reliable information on soil profile characteristics exists and which is sufficiently fine to account for the heterogeneities of these. Where such information is available, application of DryMOD can assist in the spatial and temporal planning of water harvesting according to runoff-generating areas and the runoff ratio, as well as in the optimization of agricultural activities based on realistic representation of soil moisture conditions.

  1. Definition of Iron Deficiency Based on the Gold Standard of Bone Marrow Iron Staining in Heart Failure Patients.

    Science.gov (United States)

    Grote Beverborg, Niels; Klip, IJsbrand T; Meijers, Wouter C; Voors, Adriaan A; Vegter, Eline L; van der Wal, Haye H; Swinkels, Dorine W; van Pelt, Joost; Mulder, Andre B; Bulstra, Sjoerd K; Vellenga, Edo; Mariani, Massimo A; de Boer, Rudolf A; van Veldhuisen, Dirk J; van der Meer, Peter

    2018-02-01

    The most commonly used definition of iron deficiency (ID; ferritin the biomarker-based definition of ID in HF, using bone marrow iron staining as the gold standard. Second, we aimed to assess the prognostic value of the optimized definition. Bone marrow aspiration with iron staining was performed in 42 patients with HF and a reduced left ventricular ejection fraction (≤45%) undergoing median sternotomy for coronary artery bypass grafting. Patients were mostly male (76%) with mild-to-moderate HF and a mean age of 68±10 years. Bone marrow ID was found in 17 (40%) of the HF patients. The most commonly used definition of ID had a sensitivity of 82% and a specificity of 72%. A definition solely based on TSAT ≤19.8% or serum iron ≤13 µmol/L had a sensitivity of 94% and specificity of 84% and 88%, respectively ( P the former definition). Subsequently, we assessed the incidence of all-cause mortality in 387 consecutive outpatient HF patients (left ventricular ejection fraction ≤45%). In these patients, TSAT ≤19.8% and serum iron ≤13 µmol/L, and not ferritin, were independently associated with mortality. A TSAT ≤19.8% or a serum iron ≤13 µmol/L shows the best performance in selecting patients with ID and identifies HF patients at the highest risk of death. Our findings validate the currently used TSAT cutoff of the identification of ID in HF patients, but question the diagnostic value of ferritin. © 2018 American Heart Association, Inc.

  2. Nonequilibrium molecular dynamics simulation of coupling between nanoparticles and base-fluid in a nanofluid

    International Nuclear Information System (INIS)

    Kang, Hongbo; Zhang, Yuwen; Yang, Mo; Li, Ling

    2012-01-01

    The intent of this study is to examine nonequilibrium heat transfer in a copper–argon nanofluid by molecular dynamics simulation. Two different methods, the physical definition method and the curve fitting method, are introduced to calculate the coupling factor between nanoparticles and base fluid. The results show that the coupling factors obtained by these two methods are consistent. The coupling factor is proportional to the volume fraction of the nanoparticle and inversely proportional to nanoparticle diameter. In the temperature range of 90–200 K, the coupling factor is not affected by temperature. The nanoparticle aggregation results in a decrease of the coupling factor. -- Highlights: ► Nonequilibrium heat transfer in a copper–argon nanofluid is investigated by molecular dynamics simulation. ► The coupling factor is proportion to the volume fraction of the nanoparticle and inverse proportion to nanoparticle diameter. ► In the temperature range of 90–200 K, there is no temperature effect on the coupling factor. ► The nanoparticle aggregation results in a decrease of the coupling factor.

  3. A simplified CT-based definition of the lymph node levels in the node negative neck

    International Nuclear Information System (INIS)

    Wijers, O.B.; Levendag, P.C.; Tan, T.; Dieren, E.B. van; Sornsen de Koste, J. van; Est, H. van der; Senan, S.; Nowak, P.J.C.M.

    1999-01-01

    Using three dimensional (3D) conformal radiotherapy (CRT) techniques for elective neck irradiation (ENI) may allow for local disease control to be maintained while diminishing xerostomia by eliminating major salivary glands (or parts thereof) from the treatment portals. The standardization of CT based target volumes for the clinically negative (elective) neck is a prerequisite for 3DCRT. The aim of the present study was to substantially modify an existing ('original') CT-based protocol for the delineation of the neck tar-et volume, into a more practical ('simplified') protocol. This will allow for rapid contouring and the implementation of conformal ENI in routine clinical procedures. An earlier ('original') version of the CT-based definition for elective neck node re-ions 2-5 was re-evaluated, using 15 planning CT scans of previously treated patients. The contouring guidelines were simplified by (1) using a smaller number of easily identifiable soft tissue- and bony anatomical landmarks, which in turn had to be identified in only a limited number of CT slices, and (2) by subsequently interpolating the contoured lymph node regions. The adequacy of target coverage and the sparing using both 'original' and 'simplified' delineation protocols was evaluated by DVH analysis after contouring the primary tumor, the neck and the major salivary glands in a patient with supraglottic laryngeal (SGL) carcinoma who was treated using a 3DCRT technique. The BEV projections of the 'original' and the 'simplified' versions of the 3D elective neck target showed good agreement and were found to be reproducible. The DVH's of the target and parotid glands were not significantly different using both contouring protocols. The 'simplified' protocol for the delineation of the 3D elective neck target produced both comparable target coverage and sparing of the major salivary glands. When used together with an interpolation program, this 'simplified' protocol substantial reduced the contouring

  4. A three-dimensional CT-based target definition for elective irradiation of the neck

    International Nuclear Information System (INIS)

    Nowak, Peter J.C.M.; Wijers, Oda B.; Lagerwaard, Frank J.; Levendag, Peter C.

    1999-01-01

    Introduction: Elective treatment of the clinically node-negative neck by radiation results in excellent control rates. However, radiation therapy with its organ-preserving properties is not without morbidity. Side effects of elective neck irradiation are mainly due to damage of the major and minor salivary glands, resulting in the dry mouth syndrome. Given that RT is the preferred treatment modality in case of elective treatment of the neck in many institutions, it is of utmost importance to try and reduce the associated sequelae of RT. Material and Methods: With the introduction of CT-planning systems and the development of 3D conformal radiation therapy (3D CRT) techniques, it has become feasible to deliver adequate doses of radiation to the target (neck) and at the same time saving (parts of) the salivary glands from doses beyond tolerance. A prerequisite for these techniques is that they require a precise knowledge of the target (i.e., of the elective neck) on CT. To be able to correlate borders of the surgical levels in the neck (I-VI) with structures seen on CT, an anatomical study, using two fixed (phenol, formaldehyde) human cadavers, was performed. Subsequently, the 6 potential lymph node regions in the neck on CT were defined. Results and Discussion: The reference for the current 3D CT-based definition of the lymph node regions in the neck is the official report of the American Academy of Otolaryngology, describing, based on surgical anatomy, the lymph node groups in the neck by Levels I-VI. The present investigation depicts reproducible landmarks on transversal CT images, corresponding to anatomical reference structures known from surgical levels (I-VI) and, this way, CT-based lymph node regions (1-6) were constructed

  5. Dynamic Chest Image Analysis: Model-Based Perfusion Analysis in Dynamic Pulmonary Imaging

    Directory of Open Access Journals (Sweden)

    Kiuru Aaro

    2003-01-01

    Full Text Available The "Dynamic Chest Image Analysis" project aims to develop model-based computer analysis and visualization methods for showing focal and general abnormalities of lung ventilation and perfusion based on a sequence of digital chest fluoroscopy frames collected with the dynamic pulmonary imaging technique. We have proposed and evaluated a multiresolutional method with an explicit ventilation model for ventilation analysis. This paper presents a new model-based method for pulmonary perfusion analysis. According to perfusion properties, we first devise a novel mathematical function to form a perfusion model. A simple yet accurate approach is further introduced to extract cardiac systolic and diastolic phases from the heart, so that this cardiac information may be utilized to accelerate the perfusion analysis and improve its sensitivity in detecting pulmonary perfusion abnormalities. This makes perfusion analysis not only fast but also robust in computation; consequently, perfusion analysis becomes computationally feasible without using contrast media. Our clinical case studies with 52 patients show that this technique is effective for pulmonary embolism even without using contrast media, demonstrating consistent correlations with computed tomography (CT and nuclear medicine (NM studies. This fluoroscopical examination takes only about 2 seconds for perfusion study with only low radiation dose to patient, involving no preparation, no radioactive isotopes, and no contrast media.

  6. Acidity constants from DFT-based molecular dynamics simulations

    International Nuclear Information System (INIS)

    Sulpizi, Marialore; Sprik, Michiel

    2010-01-01

    In this contribution we review our recently developed method for the calculation of acidity constants from density functional theory based molecular dynamics simulations. The method is based on a half reaction scheme in which protons are formally transferred from solution to the gas phase. The corresponding deprotonation free energies are computed from the vertical energy gaps for insertion or removal of protons. Combined to full proton transfer reactions, the deprotonation energies can be used to estimate relative acidity constants and also the Broensted pK a when the deprotonation free energy of a hydronium ion is used as a reference. We verified the method by investigating a series of organic and inorganic acids and bases spanning a wide range of pK a values (20 units). The thermochemical corrections for the biasing potentials assisting and directing the insertion are discussed in some detail.

  7. A comparison of heat wave climatologies and trends in China based on multiple definitions

    Science.gov (United States)

    You, Qinglong; Jiang, Zhihong; Kong, Lei; Wu, Zhiwei; Bao, Yutao; Kang, Shichang; Pepin, Nick

    2017-06-01

    Heat waves (HWs) can have disastrous impacts on human activities and natural systems, and are one of the current foci of scientific research, particularly in the context of global warming. However, there is no standard definition of a HW, which makes assessment of temporal trends a challenge. In this study, based on daily mean, maximum and minimum temperature, and relative humidity datasets from China Meteorological Administration, the patterns, trends and variations of HW in China during 1961-2014 are investigated. Sixteen previously published HW indices (HIs) are calculated, which are divided into two types using relative and absolute threshold temperatures, respectively. During 1961-2014, both relative and absolute threshold HIs show the highest number of HW in Jianghua and South China, geographically consistent with the climate characteristics of China. The majority of HIs shows negative/positive trends of HW days before/after 1990 over the whole of China, but especially in Jianghua and South China, which reflects rapid warming since 1990. There are significant correlations among different HIs in the same type (both absolute and relative), but correlations are weak between relative and absolute threshold HIs. Because relative and absolute HIs show contrasting trends, the choice of HI is therefore critical for future analysis

  8. Landmark Agnosia: Evaluating the Definition of Landmark-based Navigation Impairment.

    Science.gov (United States)

    van der Ham, Ineke J M; Martens, Marieke A G; Claessen, Michiel H G; van den Berg, Esther

    2017-06-01

    Landmark agnosia is a rare type of navigation impairment, for which various definitions have been presented. From a clinical as well as theoretical perspective, consensus on the characteristics of landmark agnosia would be valuable. In the current study we review the literature concerning landmark agnosia and present a new case study. Existing literature highlights the importance of examining familiar as well as novel landmark processing and substantial variation in performance patterns of individual patients. We performed a case study with patient KS, a 53-year-old male, suffering from landmark agnosia, making use of elaborate neuropsychological screening and virtual reality-based tests of navigation ability. Our extensive examination of his impairment shows that landmark agnosia can be very narrow; in KS it is restricted to recognition of newly learned landmarks only. Also, he has no trouble recognizing familiar landmarks that are not part of a navigated route. The literature review shows that the right temporal lobe, and the right hippocampus in particular are the main lesion sites for landmark agnosia. Furthermore, our case study substantiates that this disorder can occur for both familiar and novel landmarks, and can affect novel landmarks in isolation from familiar landmarks. Moreover, it can occur in isolation from problems with processing route information. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  9. A novel grid-based mesoscopic model for evacuation dynamics

    Science.gov (United States)

    Shi, Meng; Lee, Eric Wai Ming; Ma, Yi

    2018-05-01

    This study presents a novel grid-based mesoscopic model for evacuation dynamics. In this model, the evacuation space is discretised into larger cells than those used in microscopic models. This approach directly computes the dynamic changes crowd densities in cells over the course of an evacuation. The density flow is driven by the density-speed correlation. The computation is faster than in traditional cellular automata evacuation models which determine density by computing the movements of each pedestrian. To demonstrate the feasibility of this model, we apply it to a series of practical scenarios and conduct a parameter sensitivity study of the effect of changes in time step δ. The simulation results show that within the valid range of δ, changing δ has only a minor impact on the simulation. The model also makes it possible to directly acquire key information such as bottleneck areas from a time-varied dynamic density map, even when a relatively large time step is adopted. We use the commercial software AnyLogic to evaluate the model. The result shows that the mesoscopic model is more efficient than the microscopic model and provides more in-situ details (e.g., pedestrian movement pattern) than the macroscopic models.

  10. Cross-covariance based global dynamic sensitivity analysis

    Science.gov (United States)

    Shi, Yan; Lu, Zhenzhou; Li, Zhao; Wu, Mengmeng

    2018-02-01

    For identifying the cross-covariance source of dynamic output at each time instant for structural system involving both input random variables and stochastic processes, a global dynamic sensitivity (GDS) technique is proposed. The GDS considers the effect of time history inputs on the dynamic output. In the GDS, the cross-covariance decomposition is firstly developed to measure the contribution of the inputs to the output at different time instant, and an integration of the cross-covariance change over the specific time interval is employed to measure the whole contribution of the input to the cross-covariance of output. Then, the GDS main effect indices and the GDS total effect indices can be easily defined after the integration, and they are effective in identifying the important inputs and the non-influential inputs on the cross-covariance of output at each time instant, respectively. The established GDS analysis model has the same form with the classical ANOVA when it degenerates to the static case. After degeneration, the first order partial effect can reflect the individual effects of inputs to the output variance, and the second order partial effect can reflect the interaction effects to the output variance, which illustrates the consistency of the proposed GDS indices and the classical variance-based sensitivity indices. The MCS procedure and the Kriging surrogate method are developed to solve the proposed GDS indices. Several examples are introduced to illustrate the significance of the proposed GDS analysis technique and the effectiveness of the proposed solution.

  11. Osmosis-Based Pressure Generation: Dynamics and Application

    Science.gov (United States)

    Li, Suyi; Billeh, Yazan N.; Wang, K. W.; Mayer, Michael

    2014-01-01

    This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators. PMID:24614529

  12. Algorithm for Stabilizing a POD-Based Dynamical System

    Science.gov (United States)

    Kalb, Virginia L.

    2010-01-01

    This algorithm provides a new way to improve the accuracy and asymptotic behavior of a low-dimensional system based on the proper orthogonal decomposition (POD). Given a data set representing the evolution of a system of partial differential equations (PDEs), such as the Navier-Stokes equations for incompressible flow, one may obtain a low-dimensional model in the form of ordinary differential equations (ODEs) that should model the dynamics of the flow. Temporal sampling of the direct numerical simulation of the PDEs produces a spatial time series. The POD extracts the temporal and spatial eigenfunctions of this data set. Truncated to retain only the most energetic modes followed by Galerkin projection of these modes onto the PDEs obtains a dynamical system of ordinary differential equations for the time-dependent behavior of the flow. In practice, the steps leading to this system of ODEs entail numerically computing first-order derivatives of the mean data field and the eigenfunctions, and the computation of many inner products. This is far from a perfect process, and often results in the lack of long-term stability of the system and incorrect asymptotic behavior of the model. This algorithm describes a new stabilization method that utilizes the temporal eigenfunctions to derive correction terms for the coefficients of the dynamical system to significantly reduce these errors.

  13. Experimental oligopolies modeling: A dynamic approach based on heterogeneous behaviors

    Science.gov (United States)

    Cerboni Baiardi, Lorenzo; Naimzada, Ahmad K.

    2018-05-01

    In the rank of behavioral rules, imitation-based heuristics has received special attention in economics (see [14] and [12]). In particular, imitative behavior is considered in order to understand the evidences arising in experimental oligopolies which reveal that the Cournot-Nash equilibrium does not emerge as unique outcome and show that an important component of the production at the competitive level is observed (see e.g.[1,3,9] or [7,10]). By considering the pioneering groundbreaking approach of [2], we build a dynamical model of linear oligopolies where heterogeneous decision mechanisms of players are made explicit. In particular, we consider two different types of quantity setting players characterized by different decision mechanisms that coexist and operate simultaneously: agents that adaptively adjust their choices towards the direction that increases their profit are embedded with imitator agents. The latter ones use a particular form of proportional imitation rule that considers the awareness about the presence of strategic interactions. It is noteworthy that the Cournot-Nash outcome is a stationary state of our models. Our thesis is that the chaotic dynamics arousing from a dynamical model, where heterogeneous players are considered, are capable to qualitatively reproduce the outcomes of experimental oligopolies.

  14. Osmosis-based pressure generation: dynamics and application.

    Science.gov (United States)

    Bruhn, Brandon R; Schroeder, Thomas B H; Li, Suyi; Billeh, Yazan N; Wang, K W; Mayer, Michael

    2014-01-01

    This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators.

  15. Osmosis-based pressure generation: dynamics and application.

    Directory of Open Access Journals (Sweden)

    Brandon R Bruhn

    Full Text Available This paper describes osmotically-driven pressure generation in a membrane-bound compartment while taking into account volume expansion, solute dilution, surface area to volume ratio, membrane hydraulic permeability, and changes in osmotic gradient, bulk modulus, and degree of membrane fouling. The emphasis lies on the dynamics of pressure generation; these dynamics have not previously been described in detail. Experimental results are compared to and supported by numerical simulations, which we make accessible as an open source tool. This approach reveals unintuitive results about the quantitative dependence of the speed of pressure generation on the relevant and interdependent parameters that will be encountered in most osmotically-driven pressure generators. For instance, restricting the volume expansion of a compartment allows it to generate its first 5 kPa of pressure seven times faster than without a restraint. In addition, this dynamics study shows that plants are near-ideal osmotic pressure generators, as they are composed of many small compartments with large surface area to volume ratios and strong cell wall reinforcements. Finally, we demonstrate two applications of an osmosis-based pressure generator: actuation of a soft robot and continuous volume delivery over long periods of time. Both applications do not need an external power source but rather take advantage of the energy released upon watering the pressure generators.

  16. General Dynamic Equivalent Modeling of Microgrid Based on Physical Background

    Directory of Open Access Journals (Sweden)

    Changchun Cai

    2015-11-01

    Full Text Available Microgrid is a new power system concept consisting of small-scale distributed energy resources; storage devices and loads. It is necessary to employ a simplified model of microgrid in the simulation of a distribution network integrating large-scale microgrids. Based on the detailed model of the components, an equivalent model of microgrid is proposed in this paper. The equivalent model comprises two parts: namely, equivalent machine component and equivalent static component. Equivalent machine component describes the dynamics of synchronous generator, asynchronous wind turbine and induction motor, equivalent static component describes the dynamics of photovoltaic, storage and static load. The trajectory sensitivities of the equivalent model parameters with respect to the output variables are analyzed. The key parameters that play important roles in the dynamics of the output variables of the equivalent model are identified and included in further parameter estimation. Particle Swarm Optimization (PSO is improved for the parameter estimation of the equivalent model. Simulations are performed in different microgrid operation conditions to evaluate the effectiveness of the equivalent model of microgrid.

  17. Power system dynamic state estimation using prediction based evolutionary technique

    International Nuclear Information System (INIS)

    Basetti, Vedik; Chandel, Ashwani K.; Chandel, Rajeevan

    2016-01-01

    In this paper, a new robust LWS (least winsorized square) estimator is proposed for dynamic state estimation of a power system. One of the main advantages of this estimator is that it has an inbuilt bad data rejection property and is less sensitive to bad data measurements. In the proposed approach, Brown's double exponential smoothing technique has been utilised for its reliable performance at the prediction step. The state estimation problem is solved as an optimisation problem using a new jDE-self adaptive differential evolution with prediction based population re-initialisation technique at the filtering step. This new stochastic search technique has been embedded with different state scenarios using the predicted state. The effectiveness of the proposed LWS technique is validated under different conditions, namely normal operation, bad data, sudden load change, and loss of transmission line conditions on three different IEEE test bus systems. The performance of the proposed approach is compared with the conventional extended Kalman filter. On the basis of various performance indices, the results thus obtained show that the proposed technique increases the accuracy and robustness of power system dynamic state estimation performance. - Highlights: • To estimate the states of the power system under dynamic environment. • The performance of the EKF method is degraded during anomaly conditions. • The proposed method remains robust towards anomalies. • The proposed method provides precise state estimates even in the presence of anomalies. • The results show that prediction accuracy is enhanced by using the proposed model.

  18. Dynamics and Thermodynamics of Artificial Muscles Based on Nematic Gels

    Science.gov (United States)

    Hébert, M.; Kant, R.; de Gennes, P.-G.

    1997-07-01

    A scheme based on nemato-mechanical conversion has been proposed for potential artificial muscle applications (de Gennes P.-G., Hébert M. and Kant R., to appear in Macromol. Symp. (1996)). As the temperature in a nematic gel is reduced through the transition temperature, strong uniaxial deformation is encountered. We briefly expose the dynamics of contraction/elongation in this system. Work and dissipative losses are calculated for an operating cycle to get an approximative expression of the ratio work/losses, which can then be compared with real muscular efficiencies.

  19. Dynamic performance analysis of diaphragm coupling base on ABAQUS

    Directory of Open Access Journals (Sweden)

    You Wen

    2017-04-01

    Full Text Available Base on the diaphragm coupling of driving system of a rotation testing machine,FEA software ABAQUS is used to simulate the force which the coupling gets when it is working,to obtain the stress and stain during the coupling with axial misalignment and degree misalignment and to find where the maximal stress is as well as its distribution.Then the nature frequency of the coupling is calculated by use of finite element software and rotor dynamics and compared with the date of misalignment and maximum speed from the manufacture,which verifies the correctness of the model and the reliability of the calculation method.

  20. Chaos synchronization basing on symbolic dynamics with nongenerating partition.

    Science.gov (United States)

    Wang, Xingyuan; Wang, Mogei; Liu, Zhenzhen

    2009-06-01

    Using symbolic dynamics and information theory, we study the information transmission needed for synchronizing unidirectionally coupled oscillators. It is found that when sustaining chaos synchronization with nongenerating partition, the synchronization error will be larger than a critical value, although the required coupled channel capacity can be smaller than the case of using a generating partition. Then we show that no matter whether a generating or nongenerating partition is in use, a high-quality detector can guarantee the lead of the response oscillator, while the lag responding can make up the low precision of the detector. A practicable synchronization scheme basing on a nongenerating partition is also proposed in this paper.

  1. Morphing-Based Shape Optimization in Computational Fluid Dynamics

    Science.gov (United States)

    Rousseau, Yannick; Men'Shov, Igor; Nakamura, Yoshiaki

    In this paper, a Morphing-based Shape Optimization (MbSO) technique is presented for solving Optimum-Shape Design (OSD) problems in Computational Fluid Dynamics (CFD). The proposed method couples Free-Form Deformation (FFD) and Evolutionary Computation, and, as its name suggests, relies on the morphing of shape and computational domain, rather than direct shape parameterization. Advantages of the FFD approach compared to traditional parameterization are first discussed. Then, examples of shape and grid deformations by FFD are presented. Finally, the MbSO approach is illustrated and applied through an example: the design of an airfoil for a future Mars exploration airplane.

  2. Dynamic optical tweezers based assay for monitoring early drug resistance

    International Nuclear Information System (INIS)

    Wu, Xiaojing; Zhu, Siwei; Feng, Jie; Zhang, Yuquan; Min, Changjun; Yuan, X-C

    2013-01-01

    In this letter, a dynamic optical tweezers based assay is proposed and investigated for monitoring early drug resistance with Pemetrexed-resistant non-small cell lung cancer (NSCLC) cell lines. The validity and stability of the method are verified experimentally in terms of the physical parameters of the optical tweezers system. The results demonstrate that the proposed technique is more convenient and faster than traditional techniques when the capability of detecting small variations of the response of cells to a drug is maintained. (letter)

  3. Optimization algorithm based on densification and dynamic canonical descent

    Science.gov (United States)

    Bousson, K.; Correia, S. D.

    2006-07-01

    Stochastic methods have gained some popularity in global optimization in that most of them do not assume the cost functions to be differentiable. They have capabilities to avoid being trapped by local optima, and may converge even faster than gradient-based optimization methods on some problems. The present paper proposes an optimization method, which reduces the search space by means of densification curves, coupled with the dynamic canonical descent algorithm. The performances of the new method are shown on several known problems classically used for testing optimization algorithms, and proved to outperform competitive algorithms such as simulated annealing and genetic algorithms.

  4. The Role of Fast Carrier Dynamics in SOA Based Devices

    DEFF Research Database (Denmark)

    Mørk, Jesper; Berg, Tommy Winther; Nielsen, Mads Lønstrup

    2004-01-01

    and the properties of schemes relying on cross-gain as well as cross-phase modulation are discussed. The possible benefits of using SOAs with quantum dot active regions are theoretically analyzed. The bandfilling characteristics and the presence of fast capture processes may allow to reach bitrates in excess of 100......We describe the characteristics of all-optical switching schemes based on semiconductor optical amplifiers (SOAs), with particular emphasis on the role of the fast carrier dynamics. The SOA response to a single short pulse as well as to a data-modulated pulse train is investigated...

  5. A Conceptual Definition of Vocational Rehabilitation Based on the ICF : building a shared global model

    NARCIS (Netherlands)

    Escorpizo, Reuben; Reneman, Michiel F.; Ekholm, Jan; Fritz, Julie; Krupa, Terry; Marnetoft, Sven-Uno; Maroun, Claude E.; Guzman, Julietta Rodriguez; Suzuki, Yoshiko; Stucki, Gerold; Chan, Chetwyn C. H.

    Background The International Classification of Functioning, Disability and Health (ICF) is a conceptual framework and classification system by the World Health Organization (WHO) to understand functioning. The objective of this discussion paper is to offer a conceptual definition for vocational

  6. Dynamic Simulation of a Trigeneration Scheme for Domestic Purposes Based on Hybrid Techniques

    Directory of Open Access Journals (Sweden)

    Luis Acevedo

    2016-11-01

    Full Text Available In this paper, the design of a system providing electricity by coupling photovoltaic/thermal (PVT collectors and a wind turbine (WT, sanitary hot water (SHW coming from the PVT and evacuated tube collectors (ETCs and fresh water (FW produced in two seawater desalting facilities (membrane distillation, MD, and reverse osmosis, RO, has been carefully analyzed by means of a dynamic model developed in TRNSYS®. This analysis is compulsory to operate a lab-scale pilot plant that is being erected at Zaragoza, Spain. A new model-type has been included in TRNSYS® in order to include the MD unit in the scheme. A sensitivity analysis of some free-design variables, such that the ETC surface, PVT and ETC tilt, water storage tank, batteries capacities, and mass flow rates delivered to the SHW service and/or feeding the MD unit has been performed in order to propose the definite design of the scheme. The proposed base case was able to produce up to 15,311 L per year in the MD system and cover an electric energy demand of 1890 kWh. Coverage of SHW, water (including RO and MD and power is respectively 99.3%, 100% and 70%. However, daily and yearly assessment of FW, SHW and power produced with the optimized design gave a better coverage of water and energy demands for a typical single family home. The improved and definite design was able to increase its MD production in 35% and the electric energy in 7% compared with base case.

  7. An evidence-based unified definition of lifelong and acquired premature ejaculation: report of the second international society for sexual medicine ad hoc committee for the definition of premature ejaculation.

    Science.gov (United States)

    Serefoglu, Ege Can; McMahon, Chris G; Waldinger, Marcel D; Althof, Stanley E; Shindel, Alan; Adaikan, Ganesh; Becher, Edgardo F; Dean, John; Giuliano, Francois; Hellstrom, Wayne Jg; Giraldi, Annamaria; Glina, Sidney; Incrocci, Luca; Jannini, Emmanuele; McCabe, Marita; Parish, Sharon; Rowland, David; Segraves, R Taylor; Sharlip, Ira; Torres, Luiz Otavio

    2014-06-01

    The International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation developed the first evidence-based definition for lifelong premature ejaculation (PE) in 2007 and concluded that there were insufficient published objective data at that time to develop a definition for acquired PE. The aim of this article is to review and critique the current literature and develop a contemporary, evidence-based definition for acquired PE and/or a unified definition for both lifelong and acquired PE. In April 2013, the ISSM convened a second Ad Hoc Committee for the Definition of Premature Ejaculation in Bangalore, India. The same evidence-based systematic approach to literature search, retrieval, and evaluation used by the original committee was adopted. The committee unanimously agreed that men with lifelong and acquired PE appear to share the dimensions of short ejaculatory latency, reduced or absent perceived ejaculatory control, and the presence of negative personal consequences. Men with acquired PE are older, have higher incidences of erectile dysfunction, comorbid disease, and cardiovascular risk factors, and have a longer intravaginal ejaculation latency time (IELT) as compared with men with lifelong PE. A self-estimated or stopwatch IELT of 3 minutes was identified as a valid IELT cut-off for diagnosing acquired PE. On this basis, the committee agreed on a unified definition of both acquired and lifelong PE as a male sexual dysfunction characterized by (i) ejaculation that always or nearly always occurs prior to or within about 1 minute of vaginal penetration from the first sexual experience (lifelong PE) or a clinically significant and bothersome reduction in latency time, often to about 3 minutes or less (acquired PE); (ii) the inability to delay ejaculation on all or nearly all vaginal penetrations; and (iii) negative personal consequences, such as distress, bother, frustration, and/or the avoidance of sexual intimacy. The

  8. An Evidence-Based Unified Definition of Lifelong and Acquired Premature Ejaculation: Report of the Second International Society for Sexual Medicine Ad Hoc Committee for the Definition of Premature Ejaculation

    Science.gov (United States)

    Serefoglu, Ege Can; McMahon, Chris G; Waldinger, Marcel D; Althof, Stanley E; Shindel, Alan; Adaikan, Ganesh; Becher, Edgardo F; Dean, John; Giuliano, Francois; Hellstrom, Wayne JG; Giraldi, Annamaria; Glina, Sidney; Incrocci, Luca; Jannini, Emmanuele; McCabe, Marita; Parish, Sharon; Rowland, David; Segraves, R Taylor; Sharlip, Ira; Torres, Luiz Otavio

    2014-01-01

    Introduction The International Society for Sexual Medicine (ISSM) Ad Hoc Committee for the Definition of Premature Ejaculation developed the first evidence-based definition for lifelong premature ejaculation (PE) in 2007 and concluded that there were insufficient published objective data at that time to develop a definition for acquired PE. Aim The aim of this article is to review and critique the current literature and develop a contemporary, evidence-based definition for acquired PE and/or a unified definition for both lifelong and acquired PE. Methods In April 2013, the ISSM convened a second Ad Hoc Committee for the Definition of Premature Ejaculation in Bangalore, India. The same evidence-based systematic approach to literature search, retrieval, and evaluation used by the original committee was adopted. Results The committee unanimously agreed that men with lifelong and acquired PE appear to share the dimensions of short ejaculatory latency, reduced or absent perceived ejaculatory control, and the presence of negative personal consequences. Men with acquired PE are older, have higher incidences of erectile dysfunction, comorbid disease, and cardiovascular risk factors, and have a longer intravaginal ejaculation latency time (IELT) as compared with men with lifelong PE. A self-estimated or stopwatch IELT of 3 minutes was identified as a valid IELT cut-off for diagnosing acquired PE. On this basis, the committee agreed on a unified definition of both acquired and lifelong PE as a male sexual dysfunction characterized by (i) ejaculation that always or nearly always occurs prior to or within about 1 minute of vaginal penetration from the first sexual experience (lifelong PE) or a clinically significant and bothersome reduction in latency time, often to about 3 minutes or less (acquired PE); (ii) the inability to delay ejaculation on all or nearly all vaginal penetrations; and (iii) negative personal consequences, such as distress, bother, frustration, and/or the

  9. Cyberbullying or Cyber Aggression?: A Review of Existing Definitions of Cyber-Based Peer-to-Peer Aggression

    Directory of Open Access Journals (Sweden)

    Lucie Corcoran

    2015-03-01

    Full Text Available Due to the ongoing debate regarding the definitions and measurement of cyberbullying, the present article critically appraises the existing literature and offers direction regarding the question of how best to conceptualise peer-to-peer abuse in a cyber context. Variations across definitions are problematic as it has been argued that inconsistencies with regard to definitions result in researchers examining different phenomena, whilst the absence of an agreed conceptualisation of the behaviour(s involved hinders the development of reliable and valid measures. Existing definitions of cyberbullying often incorporate the criteria of traditional bullying such as intent to harm, repetition, and imbalance of power. However, due to the unique nature of cyber-based communication, it can be difficult to identify such criteria in relation to cyber-based abuse. Thus, for these reasons cyberbullying may not be the most appropriate term. Rather than attempting to “shoe-horn” this abusive behaviour into the preconceived conceptual framework that provides an understanding of traditional bullying, it is timely to take an alternative approach. We argue that it is now time to turn our attention to the broader issue of cyber aggression, rather than persist with the narrow focus that is cyberbullying.

  10. A repository based on a dynamically extensible data model supporting multidisciplinary research in neuroscience.

    Science.gov (United States)

    Corradi, Luca; Porro, Ivan; Schenone, Andrea; Momeni, Parastoo; Ferrari, Raffaele; Nobili, Flavio; Ferrara, Michela; Arnulfo, Gabriele; Fato, Marco M

    2012-10-08

    Robust, extensible and distributed databases integrating clinical, imaging and molecular data represent a substantial challenge for modern neuroscience. It is even more difficult to provide extensible software environments able to effectively target the rapidly changing data requirements and structures of research experiments. There is an increasing request from the neuroscience community for software tools addressing technical challenges about: (i) supporting researchers in the medical field to carry out data analysis using integrated bioinformatics services and tools; (ii) handling multimodal/multiscale data and metadata, enabling the injection of several different data types according to structured schemas; (iii) providing high extensibility, in order to address different requirements deriving from a large variety of applications simply through a user runtime configuration. A dynamically extensible data structure supporting collaborative multidisciplinary research projects in neuroscience has been defined and implemented. We have considered extensibility issues from two different points of view. First, the improvement of data flexibility has been taken into account. This has been done through the development of a methodology for the dynamic creation and use of data types and related metadata, based on the definition of "meta" data model. This way, users are not constrainted to a set of predefined data and the model can be easily extensible and applicable to different contexts. Second, users have been enabled to easily customize and extend the experimental procedures in order to track each step of acquisition or analysis. This has been achieved through a process-event data structure, a multipurpose taxonomic schema composed by two generic main objects: events and processes. Then, a repository has been built based on such data model and structure, and deployed on distributed resources thanks to a Grid-based approach. Finally, data integration aspects have been

  11. A repository based on a dynamically extensible data model supporting multidisciplinary research in neuroscience

    Directory of Open Access Journals (Sweden)

    Corradi Luca

    2012-10-01

    Full Text Available Abstract Background Robust, extensible and distributed databases integrating clinical, imaging and molecular data represent a substantial challenge for modern neuroscience. It is even more difficult to provide extensible software environments able to effectively target the rapidly changing data requirements and structures of research experiments. There is an increasing request from the neuroscience community for software tools addressing technical challenges about: (i supporting researchers in the medical field to carry out data analysis using integrated bioinformatics services and tools; (ii handling multimodal/multiscale data and metadata, enabling the injection of several different data types according to structured schemas; (iii providing high extensibility, in order to address different requirements deriving from a large variety of applications simply through a user runtime configuration. Methods A dynamically extensible data structure supporting collaborative multidisciplinary research projects in neuroscience has been defined and implemented. We have considered extensibility issues from two different points of view. First, the improvement of data flexibility has been taken into account. This has been done through the development of a methodology for the dynamic creation and use of data types and related metadata, based on the definition of “meta” data model. This way, users are not constrainted to a set of predefined data and the model can be easily extensible and applicable to different contexts. Second, users have been enabled to easily customize and extend the experimental procedures in order to track each step of acquisition or analysis. This has been achieved through a process-event data structure, a multipurpose taxonomic schema composed by two generic main objects: events and processes. Then, a repository has been built based on such data model and structure, and deployed on distributed resources thanks to a Grid-based approach

  12. Accuracy of dynamical-decoupling-based spectroscopy of Gaussian noise

    Science.gov (United States)

    Szańkowski, Piotr; Cywiński, Łukasz

    2018-03-01

    The fundamental assumption of dynamical-decoupling-based noise spectroscopy is that the coherence decay rate of qubit (or qubits) driven with a sequence of many pulses, is well approximated by the environmental noise spectrum spanned on frequency comb defined by the sequence. Here we investigate the precise conditions under which this commonly used spectroscopic approach is quantitatively correct. To this end we focus on two representative examples of spectral densities: the long-tailed Lorentzian, and finite-ranged Gaussian—both expected to be encountered when using the qubit for nanoscale nuclear resonance imaging. We have found that, in contrast to Lorentz spectrum, for which the corrections to the standard spectroscopic formulas can easily be made negligible, the spectra with finite range are more challenging to reconstruct accurately. For Gaussian line shape of environmental spectral density, direct application of the standard dynamical-decoupling-based spectroscopy leads to erroneous attribution of long-tail behavior to the reconstructed spectrum. Fortunately, artifacts such as this, can be completely avoided with the simple extension to standard reconstruction method.

  13. Transcriptome dynamics-based operon prediction in prokaryotes.

    Science.gov (United States)

    Fortino, Vittorio; Smolander, Olli-Pekka; Auvinen, Petri; Tagliaferri, Roberto; Greco, Dario

    2014-05-16

    Inferring operon maps is crucial to understanding the regulatory networks of prokaryotic genomes. Recently, RNA-seq based transcriptome studies revealed that in many bacterial species the operon structure vary with the change of environmental conditions. Therefore, new computational solutions that use both static and dynamic data are necessary to create condition specific operon predictions. In this work, we propose a novel classification method that integrates RNA-seq based transcriptome profiles with genomic sequence features to accurately identify the operons that are expressed under a measured condition. The classifiers are trained on a small set of confirmed operons and then used to classify the remaining gene pairs of the organism studied. Finally, by linking consecutive gene pairs classified as operons, our computational approach produces condition-dependent operon maps. We evaluated our approach on various RNA-seq expression profiles of the bacteria Haemophilus somni, Porphyromonas gingivalis, Escherichia coli and Salmonella enterica. Our results demonstrate that, using features depending on both transcriptome dynamics and genome sequence characteristics, we can identify operon pairs with high accuracy. Moreover, the combination of DNA sequence and expression data results in more accurate predictions than each one alone. We present a computational strategy for the comprehensive analysis of condition-dependent operon maps in prokaryotes. Our method can be used to generate condition specific operon maps of many bacterial organisms for which high-resolution transcriptome data is available.

  14. Rumor Diffusion in an Interests-Based Dynamic Social Network

    Directory of Open Access Journals (Sweden)

    Mingsheng Tang

    2013-01-01

    Full Text Available To research rumor diffusion in social friend network, based on interests, a dynamic friend network is proposed, which has the characteristics of clustering and community, and a diffusion model is also proposed. With this friend network and rumor diffusion model, based on the zombie-city model, some simulation experiments to analyze the characteristics of rumor diffusion in social friend networks have been conducted. The results show some interesting observations: (1 positive information may evolve to become a rumor through the diffusion process that people may modify the information by word of mouth; (2 with the same average degree, a random social network has a smaller clustering coefficient and is more beneficial for rumor diffusion than the dynamic friend network; (3 a rumor is spread more widely in a social network with a smaller global clustering coefficient than in a social network with a larger global clustering coefficient; and (4 a network with a smaller clustering coefficient has a larger efficiency.

  15. Medical applications of model-based dynamic thermography

    Science.gov (United States)

    Nowakowski, Antoni; Kaczmarek, Mariusz; Ruminski, Jacek; Hryciuk, Marcin; Renkielska, Alicja; Grudzinski, Jacek; Siebert, Janusz; Jagielak, Dariusz; Rogowski, Jan; Roszak, Krzysztof; Stojek, Wojciech

    2001-03-01

    The proposal to use active thermography in medical diagnostics is promising in some applications concerning investigation of directly accessible parts of the human body. The combination of dynamic thermograms with thermal models of investigated structures gives attractive possibility to make internal structure reconstruction basing on different thermal properties of biological tissues. Measurements of temperature distribution synchronized with external light excitation allow registration of dynamic changes of local temperature dependent on heat exchange conditions. Preliminary results of active thermography applications in medicine are discussed. For skin and under- skin tissues an equivalent thermal model may be determined. For the assumed model its effective parameters may be reconstructed basing on the results of transient thermal processes. For known thermal diffusivity and conductivity of specific tissues the local thickness of a two or three layer structure may be calculated. Results of some medical cases as well as reference data of in vivo study on animals are presented. The method was also applied to evaluate the state of the human heart during the open chest cardio-surgical interventions. Reference studies of evoked heart infarct in pigs are referred, too. We see the proposed new in medical applications technique as a promising diagnostic tool. It is a fully non-invasive, clean, handy, fast and affordable method giving not only qualitative view of investigated surfaces but also an objective quantitative measurement result, accurate enough for many applications including fast screening of affected tissues.

  16. Binaural model-based dynamic-range compression.

    Science.gov (United States)

    Ernst, Stephan M A; Kortlang, Steffen; Grimm, Giso; Bisitz, Thomas; Kollmeier, Birger; Ewert, Stephan D

    2018-01-26

    Binaural cues such as interaural level differences (ILDs) are used to organise auditory perception and to segregate sound sources in complex acoustical environments. In bilaterally fitted hearing aids, dynamic-range compression operating independently at each ear potentially alters these ILDs, thus distorting binaural perception and sound source segregation. A binaurally-linked model-based fast-acting dynamic compression algorithm designed to approximate the normal-hearing basilar membrane (BM) input-output function in hearing-impaired listeners is suggested. A multi-center evaluation in comparison with an alternative binaural and two bilateral fittings was performed to assess the effect of binaural synchronisation on (a) speech intelligibility and (b) perceived quality in realistic conditions. 30 and 12 hearing impaired (HI) listeners were aided individually with the algorithms for both experimental parts, respectively. A small preference towards the proposed model-based algorithm in the direct quality comparison was found. However, no benefit of binaural-synchronisation regarding speech intelligibility was found, suggesting a dominant role of the better ear in all experimental conditions. The suggested binaural synchronisation of compression algorithms showed a limited effect on the tested outcome measures, however, linking could be situationally beneficial to preserve a natural binaural perception of the acoustical environment.

  17. A Dynamic Neighborhood Learning-Based Gravitational Search Algorithm.

    Science.gov (United States)

    Zhang, Aizhu; Sun, Genyun; Ren, Jinchang; Li, Xiaodong; Wang, Zhenjie; Jia, Xiuping

    2018-01-01

    Balancing exploration and exploitation according to evolutionary states is crucial to meta-heuristic search (M-HS) algorithms. Owing to its simplicity in theory and effectiveness in global optimization, gravitational search algorithm (GSA) has attracted increasing attention in recent years. However, the tradeoff between exploration and exploitation in GSA is achieved mainly by adjusting the size of an archive, named , which stores those superior agents after fitness sorting in each iteration. Since the global property of remains unchanged in the whole evolutionary process, GSA emphasizes exploitation over exploration and suffers from rapid loss of diversity and premature convergence. To address these problems, in this paper, we propose a dynamic neighborhood learning (DNL) strategy to replace the model and thereby present a DNL-based GSA (DNLGSA). The method incorporates the local and global neighborhood topologies for enhancing the exploration and obtaining adaptive balance between exploration and exploitation. The local neighborhoods are dynamically formed based on evolutionary states. To delineate the evolutionary states, two convergence criteria named limit value and population diversity, are introduced. Moreover, a mutation operator is designed for escaping from the local optima on the basis of evolutionary states. The proposed algorithm was evaluated on 27 benchmark problems with different characteristic and various difficulties. The results reveal that DNLGSA exhibits competitive performances when compared with a variety of state-of-the-art M-HS algorithms. Moreover, the incorporation of local neighborhood topology reduces the numbers of calculations of gravitational force and thus alleviates the high computational cost of GSA.

  18. Dynamic Frames Based Generation of 3D Scenes and Applications

    Directory of Open Access Journals (Sweden)

    Danijel Radošević

    2015-05-01

    Full Text Available Modern graphic/programming tools like Unity enables the possibility of creating 3D scenes as well as making 3D scene based program applications, including full physical model, motion, sounds, lightning effects etc. This paper deals with the usage of dynamic frames based generator in the automatic generation of 3D scene and related source code. The suggested model enables the possibility to specify features of the 3D scene in a form of textual specification, as well as exporting such features from a 3D tool. This approach enables higher level of code generation flexibility and the reusability of the main code and scene artifacts in a form of textual templates. An example of the generated application is presented and discussed.

  19. A dynamic bead-based microarray for parallel DNA detection

    International Nuclear Information System (INIS)

    Sochol, R D; Lin, L; Casavant, B P; Dueck, M E; Lee, L P

    2011-01-01

    A microfluidic system has been designed and constructed by means of micromachining processes to integrate both microfluidic mixing of mobile microbeads and hydrodynamic microbead arraying capabilities on a single chip to simultaneously detect multiple bio-molecules. The prototype system has four parallel reaction chambers, which include microchannels of 18 × 50 µm 2 cross-sectional area and a microfluidic mixing section of 22 cm length. Parallel detection of multiple DNA oligonucleotide sequences was achieved via molecular beacon probes immobilized on polystyrene microbeads of 16 µm diameter. Experimental results show quantitative detection of three distinct DNA oligonucleotide sequences from the Hepatitis C viral (HCV) genome with single base-pair mismatch specificity. Our dynamic bead-based microarray offers an effective microfluidic platform to increase parallelization of reactions and improve microbead handling for various biological applications, including bio-molecule detection, medical diagnostics and drug screening

  20. A network-based dynamical ranking system for competitive sports

    Science.gov (United States)

    Motegi, Shun; Masuda, Naoki

    2012-12-01

    From the viewpoint of networks, a ranking system for players or teams in sports is equivalent to a centrality measure for sports networks, whereby a directed link represents the result of a single game. Previously proposed network-based ranking systems are derived from static networks, i.e., aggregation of the results of games over time. However, the score of a player (or team) fluctuates over time. Defeating a renowned player in the peak performance is intuitively more rewarding than defeating the same player in other periods. To account for this factor, we propose a dynamic variant of such a network-based ranking system and apply it to professional men's tennis data. We derive a set of linear online update equations for the score of each player. The proposed ranking system predicts the outcome of the future games with a higher accuracy than the static counterparts.

  1. Ensemble-based Kalman Filters in Strongly Nonlinear Dynamics

    Institute of Scientific and Technical Information of China (English)

    Zhaoxia PU; Joshua HACKER

    2009-01-01

    This study examines the effectiveness of ensemble Kalman filters in data assimilation with the strongly nonlinear dynamics of the Lorenz-63 model, and in particular their use in predicting the regime transition that occurs when the model jumps from one basin of attraction to the other. Four configurations of the ensemble-based Kalman filtering data assimilation techniques, including the ensemble Kalman filter, ensemble adjustment Kalman filter, ensemble square root filter and ensemble transform Kalman filter, are evaluated with their ability in predicting the regime transition (also called phase transition) and also are compared in terms of their sensitivity to both observational and sampling errors. The sensitivity of each ensemble-based filter to the size of the ensemble is also examined.

  2. Mineralization dynamics of metakaolin-based alkali-activated cements

    Science.gov (United States)

    Gevaudan, Juan Pablo; Campbell, Kate M.; Kane, Tyler; Shoemaker, Richard K.; Srubar, Wil V.

    2017-01-01

    This paper investigates the early-age dynamics of mineral formation in metakaolin-based alkali-activated cements. The effects of silica availability and alkali content on mineral formation were investigated via X-ray diffraction and solid-state 29Si magic-angle spinning nuclear magnetic resonance spectroscopy at 2, 7, 14, and 28 days. Silica availability was controlled by using either liquid- (immediate) or solid-based (gradual) sodium silicate supplements. Mineral (zeolitic) and amorphous microstructural characteristics were correlated with observed changes in bulk physical properties, namely shrinkage, density, and porosity. Results demonstrate that, while alkali content controls the mineralization in immediately available silica systems, alkali content controls the silica availability in gradually available silica systems. Immediate silica availability generally leads to a more favorable mineral formation as demonstrated by correlated improvements in bulk physical properties.

  3. Mineralization dynamics of metakaolin-based alkali-activated cements

    International Nuclear Information System (INIS)

    Gevaudan, Juan Pablo; Campbell, Kate M.; Kane, Tyler J.; Shoemaker, Richard K.; Srubar, Wil V.

    2017-01-01

    This paper investigates the early-age dynamics of mineral formation in metakaolin-based alkali-activated cements. The effects of silica availability and alkali content on mineral formation were investigated via X-ray diffraction and solid-state 29 Si magic-angle spinning nuclear magnetic resonance spectroscopy at 2, 7, 14, and 28 days. Silica availability was controlled by using either liquid- (immediate) or solid-based (gradual) sodium silicate supplements. Mineral (zeolitic) and amorphous microstructural characteristics were correlated with observed changes in bulk physical properties, namely shrinkage, density, and porosity. Results demonstrate that, while alkali content controls the mineralization in immediately available silica systems, alkali content controls the silica availability in gradually available silica systems. Immediate silica availability generally leads to a more favorable mineral formation as demonstrated by correlated improvements in bulk physical properties.

  4. Design of a dynamic model for nuclear energy management based on European Foundation for Quality Management

    International Nuclear Information System (INIS)

    Fam, I. M.; Shekari, A.

    2008-01-01

    The Business excellence model has been developed to improve and promote business levels. In business excellence model such as European Foundation for Quality Management model, the important role of resource management is emphasizes. In this paper, we have tried with consideration to tendency progressive concepts of nuclear energy management; a dynamic model has been presented for energy management within the scope of European Foundation for Quality Management model. Population growth could cause increasing of the level of energy demands. No doubt, the confidence of this developed phenomenon with the limits of environment will create greater challenges for the world and its inhabitants. Considering the shortage of energy supply all over the world, nuclear energy management has been studied with a view to fourth and fifth criterions included in European Foundation for Quality Management model (Partnership and resource and Process criteria's). In addition to it, a dynamic model has been presented for nuclear energy management within the scope of European Foundation for Quality Management model. In this dynamic model, with differential equation definition for each of the presented communications of defined causal model, input variable impacts on output ones have been determined and considered. They can be reviewed, based on six scenario plans, the importance of nuclear energy management of a business has been properly shown, and similarly the rate of investment on systems as a factor affecting the level of attention paid to the future of business enterprises, has been specified. This paper conceives nuclear energy management as an instrument to contribute to the growth and fall of a business. It is therefore, imperative to attach more importance at nuclear energy demand management in the business and an attempt should be made to keep it under our control

  5. OOK power model based dynamic error testing for smart electricity meter

    International Nuclear Information System (INIS)

    Wang, Xuewei; Chen, Jingxia; Jia, Xiaolu; Zhu, Meng; Yuan, Ruiming; Jiang, Zhenyu

    2017-01-01

    This paper formulates the dynamic error testing problem for a smart meter, with consideration and investigation of both the testing signal and the dynamic error testing method. To solve the dynamic error testing problems, the paper establishes an on-off-keying (OOK) testing dynamic current model and an OOK testing dynamic load energy (TDLE) model. Then two types of TDLE sequences and three modes of OOK testing dynamic power are proposed. In addition, a novel algorithm, which helps to solve the problem of dynamic electric energy measurement’s traceability, is derived for dynamic errors. Based on the above researches, OOK TDLE sequence generation equipment is developed and a dynamic error testing system is constructed. Using the testing system, five kinds of meters were tested in the three dynamic power modes. The test results show that the dynamic error is closely related to dynamic power mode and the measurement uncertainty is 0.38%. (paper)

  6. OOK power model based dynamic error testing for smart electricity meter

    Science.gov (United States)

    Wang, Xuewei; Chen, Jingxia; Yuan, Ruiming; Jia, Xiaolu; Zhu, Meng; Jiang, Zhenyu

    2017-02-01

    This paper formulates the dynamic error testing problem for a smart meter, with consideration and investigation of both the testing signal and the dynamic error testing method. To solve the dynamic error testing problems, the paper establishes an on-off-keying (OOK) testing dynamic current model and an OOK testing dynamic load energy (TDLE) model. Then two types of TDLE sequences and three modes of OOK testing dynamic power are proposed. In addition, a novel algorithm, which helps to solve the problem of dynamic electric energy measurement’s traceability, is derived for dynamic errors. Based on the above researches, OOK TDLE sequence generation equipment is developed and a dynamic error testing system is constructed. Using the testing system, five kinds of meters were tested in the three dynamic power modes. The test results show that the dynamic error is closely related to dynamic power mode and the measurement uncertainty is 0.38%.

  7. A dynamic regrouping based sequential dynamic programming algorithm for unit commitment of combined heat and power systems

    DEFF Research Database (Denmark)

    Rong, Aiying; Hakonen, Henri; Lahdelma, Risto

    2009-01-01

    efficiency of the plants. We introduce in this paper the DRDP-RSC algorithm, which is a dynamic regrouping based dynamic programming (DP) algorithm based on linear relaxation of the ON/OFF states of the units, sequential commitment of units in small groups. Relaxed states of the plants are used to reduce...... the dimension of the UC problem and dynamic regrouping is used to improve the solution quality. Numerical results based on real-life data sets show that this algorithm is efficient and optimal or near-optimal solutions with very small optimality gap are obtained....

  8. Flatness-based adaptive fuzzy control of chaotic finance dynamics

    Science.gov (United States)

    Rigatos, G.; Siano, P.; Loia, V.; Tommasetti, A.; Troisi, O.

    2017-11-01

    A flatness-based adaptive fuzzy control is applied to the problem of stabilization of the dynamics of a chaotic finance system, describing interaction between the interest rate, the investment demand and the price exponent. By proving that the system is differentially flat and by applying differential flatness diffeomorphisms, its transformation to the linear canonical (Brunovsky) is performed. For the latter description of the system, the design of a stabilizing state feedback controller becomes possible. A first problem in the design of such a controller is that the dynamic model of the finance system is unknown and thus it has to be identified with the use neurofuzzy approximators. The estimated dynamics provided by the approximators is used in the computation of the control input, thus establishing an indirect adaptive control scheme. The learning rate of the approximators is chosen from the requirement the system's Lyapunov function to have always a negative first-order derivative. Another problem that has to be dealt with is that the control loop is implemented only with the use of output feedback. To estimate the non-measurable state vector elements of the finance system, a state observer is implemented in the control loop. The computation of the feedback control signal requires the solution of two algebraic Riccati equations at each iteration of the control algorithm. Lyapunov stability analysis demonstrates first that an H-infinity tracking performance criterion is satisfied. This signifies elevated robustness against modelling errors and external perturbations. Moreover, the global asymptotic stability is proven for the control loop.

  9. A process-based model for the definition of hydrological alert systems in landslide risk mitigation

    Directory of Open Access Journals (Sweden)

    M. Floris

    2012-11-01

    Full Text Available The definition of hydrological alert systems for rainfall-induced landslides is strongly related to a deep knowledge of the geological and geomorphological features of the territory. Climatic conditions, spatial and temporal evolution of the phenomena and characterization of landslide triggering, together with propagation mechanisms, are the key elements to be considered. Critical steps for the development of the systems consist of the identification of the hydrological variable related to landslide triggering and of the minimum rainfall threshold for landslide occurrence.

    In this paper we report the results from a process-based model to define a hydrological alert system for the Val di Maso Landslide, located in the northeastern Italian Alps and included in the Vicenza Province (Veneto region, NE Italy. The instability occurred in November 2010, due to an exceptional rainfall event that hit the Vicenza Province and the entire NE Italy. Up to 500 mm in 3-day cumulated rainfall generated large flood conditions and triggered hundreds of landslides. During the flood, the Soil Protection Division of the Vicenza Province received more than 500 warnings of instability phenomena. The complexity of the event and the high level of risk to infrastructure and private buildings are the main reasons for deepening the specific phenomenon occurred at Val di Maso.

    Empirical and physically-based models have been used to identify the minimum rainfall threshold for the occurrence of instability phenomena in the crown area of Val di Maso landslide, where a retrogressive evolution by multiple rotational slides is expected. Empirical models helped in the identification and in the evaluation of recurrence of critical rainfall events, while physically-based modelling was essential to verify the effects on the slope stability of determined rainfall depths. Empirical relationships between rainfall and landslide consist of the calculation of rainfall

  10. Modeling Apple Surface Temperature Dynamics Based on Weather Data

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-10-01

    Full Text Available The exposure of fruit surfaces to direct sunlight during the summer months can result in sunburn damage. Losses due to sunburn damage are a major economic problem when marketing fresh apples. The objective of this study was to develop and validate a model for simulating fruit surface temperature (FST dynamics based on energy balance and measured weather data. A series of weather data (air temperature, humidity, solar radiation, and wind speed was recorded for seven hours between 11:00–18:00 for two months at fifteen minute intervals. To validate the model, the FSTs of “Fuji” apples were monitored using an infrared camera in a natural orchard environment. The FST dynamics were measured using a series of thermal images. For the apples that were completely exposed to the sun, the RMSE of the model for estimating FST was less than 2.0 °C. A sensitivity analysis of the emissivity of the apple surface and the conductance of the fruit surface to water vapour showed that accurate estimations of the apple surface emissivity were important for the model. The validation results showed that the model was capable of accurately describing the thermal performances of apples under different solar radiation intensities. Thus, this model could be used to more accurately estimate the FST relative to estimates that only consider the air temperature. In addition, this model provides useful information for sunburn protection management.

  11. Modeling apple surface temperature dynamics based on weather data.

    Science.gov (United States)

    Li, Lei; Peters, Troy; Zhang, Qin; Zhang, Jingjin; Huang, Danfeng

    2014-10-27

    The exposure of fruit surfaces to direct sunlight during the summer months can result in sunburn damage. Losses due to sunburn damage are a major economic problem when marketing fresh apples. The objective of this study was to develop and validate a model for simulating fruit surface temperature (FST) dynamics based on energy balance and measured weather data. A series of weather data (air temperature, humidity, solar radiation, and wind speed) was recorded for seven hours between 11:00-18:00 for two months at fifteen minute intervals. To validate the model, the FSTs of "Fuji" apples were monitored using an infrared camera in a natural orchard environment. The FST dynamics were measured using a series of thermal images. For the apples that were completely exposed to the sun, the RMSE of the model for estimating FST was less than 2.0 °C. A sensitivity analysis of the emissivity of the apple surface and the conductance of the fruit surface to water vapour showed that accurate estimations of the apple surface emissivity were important for the model. The validation results showed that the model was capable of accurately describing the thermal performances of apples under different solar radiation intensities. Thus, this model could be used to more accurately estimate the FST relative to estimates that only consider the air temperature. In addition, this model provides useful information for sunburn protection management.

  12. Modelling of subject specific based segmental dynamics of knee joint

    Science.gov (United States)

    Nasir, N. H. M.; Ibrahim, B. S. K. K.; Huq, M. S.; Ahmad, M. K. I.

    2017-09-01

    This study determines segmental dynamics parameters based on subject specific method. Five hemiplegic patients participated in the study, two men and three women. Their ages ranged from 50 to 60 years, weights from 60 to 70 kg and heights from 145 to 170 cm. Sample group included patients with different side of stroke. The parameters of the segmental dynamics resembling the knee joint functions measured via measurement of Winter and its model generated via the employment Kane's equation of motion. Inertial parameters in the form of the anthropometry can be identified and measured by employing Standard Human Dimension on the subjects who are in hemiplegia condition. The inertial parameters are the location of centre of mass (COM) at the length of the limb segment, inertia moment around the COM and masses of shank and foot to generate accurate motion equations. This investigation has also managed to dig out a few advantages of employing the table of anthropometry in movement biomechanics of Winter's and Kane's equation of motion. A general procedure is presented to yield accurate measurement of estimation for the inertial parameters for the joint of the knee of certain subjects with stroke history.

  13. Residential Consumption Scheduling Based on Dynamic User Profiling

    Science.gov (United States)

    Mangiatordi, Federica; Pallotti, Emiliano; Del Vecchio, Paolo; Capodiferro, Licia

    Deployment of household appliances and of electric vehicles raises the electricity demand in the residential areas and the impact of the building's electrical power. The variations of electricity consumption across the day, may affect both the design of the electrical generation facilities and the electricity bill, mainly when a dynamic pricing is applied. This paper focuses on an energy management system able to control the day-ahead electricity demand in a residential area, taking into account both the variability of the energy production costs and the profiling of the users. The user's behavior is dynamically profiled on the basis of the tasks performed during the previous days and of the tasks foreseen for the current day. Depending on the size and on the flexibility in time of the user tasks, home inhabitants are grouped in, one over N, energy profiles, using a k-means algorithm. For a fixed energy generation cost, each energy profile is associated to a different hourly energy cost. The goal is to identify any bad user profile and to make it pay a highest bill. A bad profile example is when a user applies a lot of consumption tasks and low flexibility in task reallocation time. The proposed energy management system automatically schedules the tasks, solving a multi-objective optimization problem based on an MPSO strategy. The goals, when identifying bad users profiles, are to reduce the peak to average ratio in energy demand, and to minimize the energy costs, promoting virtuous behaviors.

  14. Dynamic calibration of agent-based models using data assimilation.

    Science.gov (United States)

    Ward, Jonathan A; Evans, Andrew J; Malleson, Nicolas S

    2016-04-01

    A widespread approach to investigating the dynamical behaviour of complex social systems is via agent-based models (ABMs). In this paper, we describe how such models can be dynamically calibrated using the ensemble Kalman filter (EnKF), a standard method of data assimilation. Our goal is twofold. First, we want to present the EnKF in a simple setting for the benefit of ABM practitioners who are unfamiliar with it. Second, we want to illustrate to data assimilation experts the value of using such methods in the context of ABMs of complex social systems and the new challenges these types of model present. We work towards these goals within the context of a simple question of practical value: how many people are there in Leeds (or any other major city) right now? We build a hierarchy of exemplar models that we use to demonstrate how to apply the EnKF and calibrate these using open data of footfall counts in Leeds.

  15. Dynamic airspace configuration method based on a weighted graph model

    Directory of Open Access Journals (Sweden)

    Chen Yangzhou

    2014-08-01

    Full Text Available This paper proposes a new method for dynamic airspace configuration based on a weighted graph model. The method begins with the construction of an undirected graph for the given airspace, where the vertices represent those key points such as airports, waypoints, and the edges represent those air routes. Those vertices are used as the sites of Voronoi diagram, which divides the airspace into units called as cells. Then, aircraft counts of both each cell and of each air-route are computed. Thus, by assigning both the vertices and the edges with those aircraft counts, a weighted graph model comes into being. Accordingly the airspace configuration problem is described as a weighted graph partitioning problem. Then, the problem is solved by a graph partitioning algorithm, which is a mixture of general weighted graph cuts algorithm, an optimal dynamic load balancing algorithm and a heuristic algorithm. After the cuts algorithm partitions the model into sub-graphs, the load balancing algorithm together with the heuristic algorithm transfers aircraft counts to balance workload among sub-graphs. Lastly, airspace configuration is completed by determining the sector boundaries. The simulation result shows that the designed sectors satisfy not only workload balancing condition, but also the constraints such as convexity, connectivity, as well as minimum distance constraint.

  16. Nanoscale dynamics and aging of fibrous peptide-based gels

    Energy Technology Data Exchange (ETDEWEB)

    Dudukovic, Nikola A., E-mail: dudukov1@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Zukoski, Charles F. [Department of Chemical and Biological Engineering, University at Buffalo, Buffalo, New York 14222 (United States)

    2014-10-28

    Solutions of the aromatic dipeptide derivative molecule fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) in dimethyl sulfoxide produce fibrous gels when mixed with water. We study the evolution of density fluctuations of this three-component system using X-ray photon correlation spectroscopy (XPCS) and compare these results to the macroscopic rheology of the gels and optical observations of the microstructure evolution. At the investigated scattering angles, the intensity autocorrelation functions do not follow behavior expected for simple diffusion of individual Fmoc-FF molecules localized within cages of nearest neighbors. Instead, the dynamics are associated with density fluctuations on length scales of ∼10–100 nm arising from disaggregation and reformation of fibers, leading to an increasingly uniform network. This process is correlated with the growth of the elastic modulus, which saturates at long times. Autocorrelation functions and relaxation times acquired from XPCS measurements are consistent with relaxation rates of structures at dynamic equilibrium. This study provides further support to the concept of exploring peptide-based gelators as valence-limited patchy particles capable of forming equilibrium gels.

  17. DYNAMIC AUTHORIZATION BASED ON THE HISTORY OF EVENTS

    Directory of Open Access Journals (Sweden)

    Maxim V. Baklanovsky

    2016-11-01

    Full Text Available The new paradigm in the field of access control systems with fuzzy authorization is proposed. Let there is a set of objects in a single data transmissionnetwork. The goal is to develop dynamic authorization protocol based on correctness of presentation of events (news occurred earlier in the network. We propose mathematical method that keeps compactly the history of events, neglects more distant and least-significant events, composes and verifies authorization data. The history of events is represented as vectors of numbers. Each vector is multiplied by several stochastic vectors. The result is known that if vectors of events are sparse, then by solving the problem of -optimization they can be restored with high accuracy. Results of experiments for vectors restoring have shown that the greater the number of stochastic vectors is, the better accuracy of restored vectors is observed. It has been established that the largest absolute components are restored earlier. Access control system with the proposed dynamic authorization method enables to compute fuzzy confidence coefficients in networks with frequently changing set of participants, mesh-networks, multi-agent systems.

  18. Some implications of an event-based definition of exposure to the risk of road accident

    DEFF Research Database (Denmark)

    Elvik, Rune

    2015-01-01

    This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving the road......This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving...

  19. Simulation-Based Dynamic Passenger Flow Assignment Modelling for a Schedule-Based Transit Network

    Directory of Open Access Journals (Sweden)

    Xiangming Yao

    2017-01-01

    Full Text Available The online operation management and the offline policy evaluation in complex transit networks require an effective dynamic traffic assignment (DTA method that can capture the temporal-spatial nature of traffic flows. The objective of this work is to propose a simulation-based dynamic passenger assignment framework and models for such applications in the context of schedule-based rail transit systems. In the simulation framework, travellers are regarded as individual agents who are able to obtain complete information on the current traffic conditions. A combined route selection model integrated with pretrip route selection and entrip route switch is established for achieving the dynamic network flow equilibrium status. The train agent is operated strictly with the timetable and its capacity limitation is considered. A continuous time-driven simulator based on the proposed framework and models is developed, whose performance is illustrated through a large-scale network of Beijing subway. The results indicate that more than 0.8 million individual passengers and thousands of trains can be simulated simultaneously at a speed ten times faster than real time. This study provides an efficient approach to analyze the dynamic demand-supply relationship for large schedule-based transit networks.

  20. Dynamic functional connectivity using state-based dynamic community structure: method and application to opioid analgesia.

    Science.gov (United States)

    Robinson, Lucy F; Atlas, Lauren Y; Wager, Tor D

    2015-03-01

    We present a new method, State-based Dynamic Community Structure, that detects time-dependent community structure in networks of brain regions. Most analyses of functional connectivity assume that network behavior is static in time, or differs between task conditions with known timing. Our goal is to determine whether brain network topology remains stationary over time, or if changes in network organization occur at unknown time points. Changes in network organization may be related to shifts in neurological state, such as those associated with learning, drug uptake or experimental conditions. Using a hidden Markov stochastic blockmodel, we define a time-dependent community structure. We apply this approach to data from a functional magnetic resonance imaging experiment examining how contextual factors influence drug-induced analgesia. Results reveal that networks involved in pain, working memory, and emotion show distinct profiles of time-varying connectivity. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. A consensus-based dynamics for market volumes

    Science.gov (United States)

    Sabatelli, Lorenzo; Richmond, Peter

    2004-12-01

    We develop a model of trading orders based on opinion dynamics. The agents may be thought as the share holders of a major mutual fund rather than as direct traders. The balance between their buy and sell orders determines the size of the fund order (volume) and has an impact on prices and indexes. We assume agents interact simultaneously to each other through a Sznajd-like interaction. Their degree of connection is determined by the probability of changing opinion independently of what their neighbours are doing. We assume that such a probability may change randomly, after each transaction, of an amount proportional to the relative difference between the volatility then measured and a benchmark that we assume to be an exponential moving average of the past volume values. We show how this simple model is compatible with some of the main statistical features observed for the asset volumes in financial markets.

  2. Dynamic biogas upgrading based on the Sabatier process

    DEFF Research Database (Denmark)

    Jurgensen, Lars; Ehimen, Ehiazesebhor Augustine; Born, Jens

    2015-01-01

    index, CO2 content and calorific value were found to be controllable by the H2/CO2 ratio fed the methanation reactor. An optimal H2/CO2 ratio of 3.45–3.7 was seen to result in a product gas with high calorific value and Wobbe index. The dynamic reactor simulation verified that the process start......This study aimed to investigate the feasibility of substitute natural gas (SNG) generation using biogas from anaerobic digestion and hydrogen from renewable energy systems. Using thermodynamic equilibrium analysis, kinetic reactor modeling and transient simulation, an integrated approach...... for the operation of a biogas-based Sabatier process was put forward, which was then verified using a lab scale heterogenous methanation reactor. The process simulation using a kinetic reactor model demonstrated the feasibility of the production of SNG at gas grid standards using a single reactor setup. The Wobbe...

  3. The sequence relay selection strategy based on stochastic dynamic programming

    Science.gov (United States)

    Zhu, Rui; Chen, Xihao; Huang, Yangchao

    2017-07-01

    Relay-assisted (RA) network with relay node selection is a kind of effective method to improve the channel capacity and convergence performance. However, most of the existing researches about the relay selection did not consider the statically channel state information and the selection cost. This shortage limited the performance and application of RA network in practical scenarios. In order to overcome this drawback, a sequence relay selection strategy (SRSS) was proposed. And the performance upper bound of SRSS was also analyzed in this paper. Furthermore, in order to make SRSS more practical, a novel threshold determination algorithm based on the stochastic dynamic program (SDP) was given to work with SRSS. Numerical results are also presented to exhibit the performance of SRSS with SDP.

  4. A model of gene expression based on random dynamical systems reveals modularity properties of gene regulatory networks.

    Science.gov (United States)

    Antoneli, Fernando; Ferreira, Renata C; Briones, Marcelo R S

    2016-06-01

    Here we propose a new approach to modeling gene expression based on the theory of random dynamical systems (RDS) that provides a general coupling prescription between the nodes of any given regulatory network given the dynamics of each node is modeled by a RDS. The main virtues of this approach are the following: (i) it provides a natural way to obtain arbitrarily large networks by coupling together simple basic pieces, thus revealing the modularity of regulatory networks; (ii) the assumptions about the stochastic processes used in the modeling are fairly general, in the sense that the only requirement is stationarity; (iii) there is a well developed mathematical theory, which is a blend of smooth dynamical systems theory, ergodic theory and stochastic analysis that allows one to extract relevant dynamical and statistical information without solving the system; (iv) one may obtain the classical rate equations form the corresponding stochastic version by averaging the dynamic random variables (small noise limit). It is important to emphasize that unlike the deterministic case, where coupling two equations is a trivial matter, coupling two RDS is non-trivial, specially in our case, where the coupling is performed between a state variable of one gene and the switching stochastic process of another gene and, hence, it is not a priori true that the resulting coupled system will satisfy the definition of a random dynamical system. We shall provide the necessary arguments that ensure that our coupling prescription does indeed furnish a coupled regulatory network of random dynamical systems. Finally, the fact that classical rate equations are the small noise limit of our stochastic model ensures that any validation or prediction made on the basis of the classical theory is also a validation or prediction of our model. We illustrate our framework with some simple examples of single-gene system and network motifs. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Adverse events after cervical spinal manipulative therapy: consensus based classification and definitions

    NARCIS (Netherlands)

    Dr. C.P. van der Schans; M. Schmitt; dr. S.E. Lakke; H.A. Kranenburg

    2015-01-01

    Cervical spinal manipulations (CSM) are frequently employed techniques to alleviate neck pain and headache. Minor and major complications following CSM have been described, though clear consensus on definition and the classification of the complications had not yet been achieved. As a result,

  6. Late presentation to HIV testing is overestimated when based on the consensus definition.

    Science.gov (United States)

    Sasse, A; Florence, E; Pharris, A; De Wit, S; Lacor, P; Van Beckhoven, D; Deblonde, J; Delforge, M-L; Fransen, K; Goffard, J-C; Legrand, J-C; Moutschen, M; Piérard, D; Ruelle, J; Vaira, D; Vandercam, B; Van Ranst, M; Van Wijngaerden, E; Vandekerckhove, L; Verhofstede, C

    2016-03-01

    In 2011, a consensus was reached defining "late presenters" (LPs) as individuals presenting for care with a CD4 count account. Case surveillance data for newly diagnosed patients in Belgium in 1998-2012 were analysed, including CD4 count at diagnosis, the presence of AIDS-defining events, and recent infections (definition. Secondly, LPs were reclassified as "nonlate" if infections were reported as recent. A total of 7949 HIV diagnoses were included in the study. Recent infections were increasingly reported over time, accounting for 8.2% of new infections in 1998 and 37.5% in 2012. The consideration of clinical stage significantly modified the proportion of LPs: 18.2% of men who have sex with men (MSM) diagnosed in 2012 would be classified as LPs instead of 30.9% using the consensus definition (P definition. The impact of transient CD4 count on late presentation estimates should be assessed and, if relevant, the introduction of clinical stage in the definition of late presentation should be considered. © 2015 British HIV Association.

  7. Adverse events after cervical spinal manipulative therapy: consensus based classification and definitions

    NARCIS (Netherlands)

    Kranenburg, Rik; Jorna-Lakke, Sandra; Schmitt, M.A.; van der Schans, Cees

    2016-01-01

    Cervical spinal manipulations (CSM) are frequently employed techniques to alleviate neck pain and headache. Minor and major complications following CSM have been described, though clear consensus on definition and the classification of the complications had not yet been achieved. As a result,

  8. Optimal diabatic dynamics of Majorana-based quantum gates

    Science.gov (United States)

    Rahmani, Armin; Seradjeh, Babak; Franz, Marcel

    2017-08-01

    In topological quantum computing, unitary operations on qubits are performed by adiabatic braiding of non-Abelian quasiparticles, such as Majorana zero modes, and are protected from local environmental perturbations. In the adiabatic regime, with timescales set by the inverse gap of the system, the errors can be made arbitrarily small by performing the process more slowly. To enhance the performance of quantum information processing with Majorana zero modes, we apply the theory of optimal control to the diabatic dynamics of Majorana-based qubits. While we sacrifice complete topological protection, we impose constraints on the optimal protocol to take advantage of the nonlocal nature of topological information and increase the robustness of our gates. By using the Pontryagin's maximum principle, we show that robust equivalent gates to perfect adiabatic braiding can be implemented in finite times through optimal pulses. In our implementation, modifications to the device Hamiltonian are avoided. Focusing on thermally isolated systems, we study the effects of calibration errors and external white and 1 /f (pink) noise on Majorana-based gates. While a noise-induced antiadiabatic behavior, where a slower process creates more diabatic excitations, prohibits indefinite enhancement of the robustness of the adiabatic scheme, our fast optimal protocols exhibit remarkable stability to noise and have the potential to significantly enhance the practical performance of Majorana-based information processing.

  9. Energetics and dynamics of the non-natural fluorescent 4AP:DAP base pair

    KAUST Repository

    Chawla, Mohit; Autiero, Ida; Oliva, Romina; Cavallo, Luigi

    2018-01-01

    the experimental studies and rationalize the impact of the above non-natural bases on the structure, stability and dynamics of nucleic acid structures, we performed quantum mechanics (QM) calculations along with classical molecular dynamics (MD) simulations. QM

  10. Simulations of the structure and dynamics of nanoparticle-based ionic liquids

    KAUST Repository

    Hong, Bingbing; Chremos, Alexandros; Panagiotopoulos, Athanassios Z.

    2012-01-01

    We use molecular dynamics simulations over microsecond time scales to study the structure and dynamics of coarse-grained models for nanoparticle-based ionic liquids. The systems of interest consist of particles with charged surface groups and linear

  11. Finite Element Based Lagrangian Vortex Dynamics Model for Wind Turbine Aerodynamics

    International Nuclear Information System (INIS)

    McWilliam, Michael K; Crawford, Curran

    2014-01-01

    This paper presents a novel aerodynamic model based on Lagrangian Vortex Dynamics (LVD) formulated using a Finite Element (FE) approach. The advantage of LVD is improved fidelity over Blade Element Momentum Theory (BEMT) while being faster than Numerical Navier-Stokes Models (NNSM) in either primitive or velocity-vorticity formulations. The model improves on conventional LVD in three ways. First, the model is based on an error minimization formulation that can be solved with fast root finding algorithms. In addition to improving accuracy, this eliminates the intrinsic numerical instability of conventional relaxed wake simulations. The method has further advantages in optimization and aero-elastic simulations for two reasons. The root finding algorithm can solve the aerodynamic and structural equations simultaneously, avoiding Gauss-Seidel iteration for compatibility constraints. The second is that the formulation allows for an analytical definition for sensitivity calculations. The second improvement comes from a new discretization scheme based on an FE formulation and numerical quadrature that decouples the spatial, influencing and temporal meshes. The shape for each trailing filament uses basis functions (interpolating splines) that allow for both local polynomial order and element size refinement. A completely independent scheme distributes the influencing (vorticity) elements along the basis functions. This allows for concentrated elements in the near wake for accuracy and progressively less in the far-wake for efficiency. Finally the third improvement is the use of a far-wake model based on semi-infinite vortex cylinders where the radius and strength are related to the wake state. The error-based FE formulation allows the transition to the far wake to occur across a fixed plane

  12. Spin dynamics in 122-type iron-based superconductors

    International Nuclear Information System (INIS)

    Park, Jitae

    2012-01-01

    In this thesis, we present the experimental data on four different iron-based SC materials. It is mainly about the magnetic-dynamics study in the FeSC that is assumed to be among the most crucial ingredients for superconductivity in this system. Thus, the main goal of this thesis is to figure out the exact relationship between spin dynamics and superconductivity, and then further to realize what is the contribution of magnetic fluctuations for superconductivity by providing experimental data for modeling a microscopic mechanism of electron pairing in the FeSC system. In Chap. 2, we first discuss basic characteristics of FeSC, such as crystal structure and electron band-structure by briefly reviewing the relevant literature. Then, an introduction about magnetic and SC phases will follow based on the generic phase diagram. Details about current understanding of magnetic ground state in the parent compounds will be discussed in terms of spin-wave excitations which would be important when we are considering the spin dynamics in doped materials. To study magnetic dynamics in FeSC, we employed the inelastic-neutron-scattering (INS) method which can uniquely probe the underlying spin dynamics in the four dimensional energy and momentum space in a wide range. By taking advantage of the well developed theory for the magnetic neutron-scattering process, one can quantify the imaginary part of spin susceptibility that is an essential physical quantity the description of elementary magnetic excitations and can be compared with theoretical calculations directly. Moreover, the technique's energy-resolving scale spans over the most relevant energy range of magnetic fluctuations (from 0 to 100 meV). For these reasons, neutron scattering is a very powerful technique for magnetism study, and we introduce how neutron-scattering experiment works theoretically and practically in Chap. 3. For a slightly underdoped Ba 1-x K x Fe 2 As 2 compound, we report the phase separation between

  13. Spin dynamics in 122-type iron-based superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jitae

    2012-07-16

    In this thesis, we present the experimental data on four different iron-based SC materials. It is mainly about the magnetic-dynamics study in the FeSC that is assumed to be among the most crucial ingredients for superconductivity in this system. Thus, the main goal of this thesis is to figure out the exact relationship between spin dynamics and superconductivity, and then further to realize what is the contribution of magnetic fluctuations for superconductivity by providing experimental data for modeling a microscopic mechanism of electron pairing in the FeSC system. In Chap. 2, we first discuss basic characteristics of FeSC, such as crystal structure and electron band-structure by briefly reviewing the relevant literature. Then, an introduction about magnetic and SC phases will follow based on the generic phase diagram. Details about current understanding of magnetic ground state in the parent compounds will be discussed in terms of spin-wave excitations which would be important when we are considering the spin dynamics in doped materials. To study magnetic dynamics in FeSC, we employed the inelastic-neutron-scattering (INS) method which can uniquely probe the underlying spin dynamics in the four dimensional energy and momentum space in a wide range. By taking advantage of the well developed theory for the magnetic neutron-scattering process, one can quantify the imaginary part of spin susceptibility that is an essential physical quantity the description of elementary magnetic excitations and can be compared with theoretical calculations directly. Moreover, the technique's energy-resolving scale spans over the most relevant energy range of magnetic fluctuations (from 0 to 100 meV). For these reasons, neutron scattering is a very powerful technique for magnetism study, and we introduce how neutron-scattering experiment works theoretically and practically in Chap. 3. For a slightly underdoped Ba{sub 1-x}K{sub x}Fe{sub 2}As{sub 2} compound, we report the phase

  14. Revisiting essential hypertension--a "mechanism-based" approach may argue for a better definition of hypertension.

    Science.gov (United States)

    Calò, L A

    2009-08-01

    Several major overarching themes have recently emerged in our understanding of the pathophysiology of hypertension which may allow to revisit essential hypertension with an eye towards the possibility of adopting a more rational "mechanistic-based" definition of hypertension and moving away from the unsatisfactory "essential" label for hypertension from unknown cause. As our understanding of the biochemical and physiological mechanisms that control blood pressure rapidly evolves, the "essential" label of hypertension is losing both value as well as utility as it will describe an increasingly small number of hypertensive patients. This paper uses some recently identified pathways central to hypertension and uses this understanding of pathophysiology to argue for a better definition of hypertension.

  15. Model-based dynamic control and optimization of gas networks

    Energy Technology Data Exchange (ETDEWEB)

    Hofsten, Kai

    2001-07-01

    by a structured sequential quadratic programming algorithm of Newton type. Each open loop problem is specified using a nonlinear prediction model. For each iteration of the quadratic programming procedure, a linear time variant prediction model is formulated. The suggested controller also handles time varying source capacity. Potential problems such as infeasibility and the security of the supply when facing a change in the status of the infrastructure of the transmission system under a transient customer load are treated. Comments on the infeasibility due to errors such as load forecast error, model error and state estimation error are also discussed. A simplified nonlinear model called the creep flow model is used to describe the fluid dynamics inside a natural gas transmission line. Different assumptions and reformulations of this model yield the different control, simulation and optimization models used in this thesis. The control of a single gas transmission line is investigated using linear model predictive control based on instant linearization of the nonlinear model. Model predictive control using a bi quadratic optimization model formulated from the creep flow model is also investigated. A distributed parameter control model of the gas dynamics for a transmission line is formulated. An analytic solution of this model is given with both Neuman boundary conditions and distributed supplies and loads. A transfer function model is developed expressing the dynamics between the defined output and the control and disturbance inputs of the transmission line. Based on the qualitative behaviour observed from the step responses of the solutions of the distributed parameter model formulated in this thesis, simplified transfer function models were developed. These control models expresses the dynamics of a natural gas transmission line with Neuman boundary control and load. Further, these models were used to design a control law, which is a combination of a Smith

  16. Dynamical Constants and Time Universals: A First Step toward a Metrical Definition of Ordered and Abnormal Cognition.

    Science.gov (United States)

    Elliott, Mark A; du Bois, Naomi

    2017-01-01

    From the point of view of the cognitive dynamicist the organization of brain circuitry into assemblies defined by their synchrony at particular (and precise) oscillation frequencies is important for the correct correlation of all independent cortical responses to the different aspects of a given complex thought or object. From the point of view of anyone operating complex mechanical systems, i.e., those comprising independent components that are required to interact precisely in time, it follows that the precise timing of such a system is essential - not only essential but measurable, and scalable. It must also be reliable over observations to bring about consistent behavior, whatever that behavior is. The catastrophic consequence of an absence of such precision, for instance that required to govern the interference engine in many automobiles, is indicative of how important timing is for the function of dynamical systems at all levels of operation. The dynamics and temporal considerations combined indicate that it is necessary to consider the operating characteristic of any dynamical, cognitive brain system in terms, superficially at least, of oscillation frequencies. These may, themselves, be forensic of an underlying time-related taxonomy. Currently there are only two sets of relevant and necessarily systematic observations in this field: one of these reports the precise dynamical structure of the perceptual systems engaged in dynamical binding across form and time; the second, derived both empirically from perceptual performance data, as well as obtained from theoretical models, demonstrates a timing taxonomy related to a fundamental operator referred to as the time quantum. In this contribution both sets of theory and observations are reviewed and compared for their predictive consistency. Conclusions about direct comparability are discussed for both theories of cognitive dynamics and time quantum models. Finally, a brief review of some experimental data

  17. Manipulation of Microobjects Based on Dynamic Adhesion Control

    Directory of Open Access Journals (Sweden)

    Tao Chen

    2012-09-01

    Full Text Available Due to scale effects, microoperation, especially the releasing of microobjects, has been a long-standing challenge in micromanipulation applications. In this paper a micromanipulation method is presented based on dynamic adhesion control with compound vibration. This adhesion control technique employs inertia force to overcome adhesion force achieving 100% repeatability with releasing accuracy of 4± 0.5μm, which was experimentally quantified through the manipulation of 20–100μm polystyrene spheres under an optical microscope. The micromanipulation system consists of a microgripper and a piezoelectric ceramics module. The compound vibration comes from the electrostatic actuator and the piezoelectrically driven actuator. Surface and bulk micromachining technology is employed to fabricate the microgripper used in the system from a single crystal silicon wafer. Experimental results confirmed that this adhesion control technique is independent of substrate. Theoretical analyses were conducted to understand the picking up and releasing mechanism. Based on this preliminary study, the micromanipulation system proved to be an effective solution for active picking up and releasing of micromanipulation.

  18. A new feedback image encryption scheme based on perturbation with dynamical compound chaotic sequence cipher generator

    Science.gov (United States)

    Tong, Xiaojun; Cui, Minggen; Wang, Zhu

    2009-07-01

    The design of the new compound two-dimensional chaotic function is presented by exploiting two one-dimensional chaotic functions which switch randomly, and the design is used as a chaotic sequence generator which is proved by Devaney's definition proof of chaos. The properties of compound chaotic functions are also proved rigorously. In order to improve the robustness against difference cryptanalysis and produce avalanche effect, a new feedback image encryption scheme is proposed using the new compound chaos by selecting one of the two one-dimensional chaotic functions randomly and a new image pixels method of permutation and substitution is designed in detail by array row and column random controlling based on the compound chaos. The results from entropy analysis, difference analysis, statistical analysis, sequence randomness analysis, cipher sensitivity analysis depending on key and plaintext have proven that the compound chaotic sequence cipher can resist cryptanalytic, statistical and brute-force attacks, and especially it accelerates encryption speed, and achieves higher level of security. By the dynamical compound chaos and perturbation technology, the paper solves the problem of computer low precision of one-dimensional chaotic function.

  19. The population dynamics of the parasitic copepode Lernaeocera lusci (Bassett-Smith, 1896) on its definitive host

    Science.gov (United States)

    van Damme, P. A.; Hamerlynck, O.; Ollevier, F.

    1996-06-01

    The mesoparasitic copepod Lernaeocera lusci (Bassett-Smith, 1896) was recovered from first-year bib ( Trisopterus luscus L.) in the Voordelta (Southern Bight of the North Sea) from May until December 1989. Analysis of the seasonal abundance and of the population structure showed that transmission of infective stages to bib mainly occurred from June to September. From September to December the overall prevalence fluctuated around 70%. Maximum parasite population size (47/104m2) and the highest total egg number were recorded in September and October, respectively. It was found that total parasite mortality was significantly influenced by mortality of hosts carrying parasites. Natural mortality probably contributed a small percentage to total parasite mortality. Calculation of the temporal mean-variance regression equation revealed that the parasites were aggregated within the definitive host population.

  20. A constraint-based bottom-up counterpart to definite clause grammars

    DEFF Research Database (Denmark)

    Christiansen, Henning

    2004-01-01

    A new grammar formalism, CHR Grammars (CHRG), is proposed that provides a constraint-solving approach to language analysis, built on top of the programming language of Constraint Handling Rules in the same way as Definite Clause Grammars (DCG) on Prolog. CHRG works bottom-up and adds the following......, integrity constraints, operators a la assumption grammars, and to incorporate other constraint solvers. (iv)~Context-sensitive rules that apply for disambiguation, coordination in natural language and tagger-like rules....

  1. Agent Based Modeling on Organizational Dynamics of Terrorist Network

    OpenAIRE

    Bo Li; Duoyong Sun; Renqi Zhu; Ze Li

    2015-01-01

    Modeling organizational dynamics of terrorist network is a critical issue in computational analysis of terrorism research. The first step for effective counterterrorism and strategic intervention is to investigate how the terrorists operate with the relational network and what affects the performance. In this paper, we investigate the organizational dynamics by employing a computational experimentation methodology. The hierarchical cellular network model and the organizational dynamics model ...

  2. The quest for a universal definition of polytrauma: a trauma registry-based validation study.

    Science.gov (United States)

    Butcher, Nerida E; D'Este, Catherine; Balogh, Zsolt J

    2014-10-01

    A pilot validation recommended defining polytrauma as patients with an Abbreviated Injury Scale (AIS) score greater than 2 in at least two Injury Severity Score (ISS) body regions (2 × AIS score > 2). This study aimed to validate this definition on larger data set. We hypothesized that patients defined by the 2 × AIS score > 2 cutoff have worse outcomes and use more resources than those without 2 × AIS score > 2 and that this would therefore be a better definition of polytrauma. Patients injured between 2009 and 2011, with complete documentation of AIS by New South Wales Trauma Registry and 16 years and older were selected. Age and sex were obtained in addition to outcomes of ISS, hospital length of stay (LOS), intensive care unit (ICU) admission, ICU LOS, and mortality. We compared demographic characteristics and outcomes between patients with ISS greater than 15 who did and did not meet the 2 × AIS score > 2 definition. We then undertook regression analyses (logistic regression for binary outcomes [ICU admission and death] and linear regression for hospital and ICU LOS) to compare outcomes for patients with and without 2 × AIS score > 2, adjusting for sex and age categories. In the adjusted analyses, patients with 2 × AIS score > 2 had twice the odds of being admitted to the ICU compared with those without 2 × AIS score > 2 (odds ratio, 2.5; 95% confidence interval [CI], 2.2-2.8) and 1.7 times the odds of dying (95% CI, 1.4-2.0; p 2 also had a mean difference of 1.5 days longer stay in the hospital compared with those without 2 × AIS score > 2 (95% CI, 1.4-1.7) and 1.6 days longer ICU stay (95% CI, 1.4-1.8; p 2 had higher mortality, more frequent ICU admissions, and longer hospital and ICU stay than those without 2 × AIS score > 2 and represents a superior definition to the definitions for polytrauma currently in use. Diagnostic test/ criteria, level III.

  3. Measurement of elastic modulus and Vickers hardness of surround bone implant using dynamic microindentation--parameters definition.

    Science.gov (United States)

    Soares, Priscilla Barbosa Ferreira; Nunes, Sarah Arantes; Franco, Sinésio Domingues; Pires, Raphael Rezende; Zanetta-Barbosa, Darceny; Soares, Carlos José

    2014-01-01

    The clinical performance of dental implants is strongly defined by biomechanical principles. The aim of this study was to quantify the Vicker's hardness (VHN) and elastic modulus (E) surround bone to dental implant in different regions, and to discuss the parameters of dynamic microindantion test. Ten cylindrical implants with morse taper interface (Titamax CM, Neodent; 3.5 mm diameter and 7 mm a height) were inserted in rabbit tibia. The mechanical properties were analyzed using microhardness dynamic indenter with 200 mN load and 15 s penetration time. Seven continuous indentations were made distancing 0.08 mm between each other perpendicularly to the implant-bone interface towards the external surface, at the limit of low (Lp) and high implant profile (Hp). Data were analyzed by Student's t-test (a=0.05) to compare the E and VHN values obtained on both regions. Mean and standard deviation of E (GPa) were: Lp. 16.6 ± 1.7, Hp. 17.0 ± 2.5 and VHN (N/mm2): Lp. 12.6 ± 40.8, Hp. 120.1 ± 43.7. No statistical difference was found between bone mechanical properties of high and low profile of the surround bone to implant, demonstrating that the bone characterization homogeneously is pertinent. Dynamic microindantion method proved to be highly useful in the characterization of the individual peri-implant bone tissue.

  4. Dynamic Optimization Design of Cranes Based on Human–Crane–Rail System Dynamics and Annoyance Rate

    Directory of Open Access Journals (Sweden)

    Yunsheng Xin

    2017-01-01

    Full Text Available The operators of overhead traveling cranes experience discomfort as a result of the vibrations of crane structures. These vibrations are produced by defects in the rails on which the cranes move. To improve the comfort of operators, a nine-degree-of-freedom (nine-DOF mathematical model of a “human–crane–rail” system was constructed. Based on the theoretical guidance provided in ISO 2631-1, an annoyance rate model was established, and quantization results were determined. A dynamic optimization design method for overhead traveling cranes is proposed. A particle swarm optimization (PSO algorithm was used to optimize the crane structural design, with the structure parameters as the basic variables, the annoyance rate model as the objective function, and the acceleration amplitude and displacement amplitude of the crane as the constraint conditions. The proposed model and method were used to optimize the design of a double-girder 100 t–28.5 m casting crane, and the optimal parameters are obtained. The results show that optimization decreases the human annoyance rate from 28.3% to 9.8% and the root mean square of the weighted acceleration of human vibration from 0.59 m/s2 to 0.38 m/s2. These results demonstrate the effectiveness and practical applicability of the models and method proposed in this paper.

  5. A forecasting performance comparison of dynamic factor models based on static and dynamic methods

    Directory of Open Access Journals (Sweden)

    Marra Fabio Della

    2017-03-01

    Full Text Available We present a comparison of the forecasting performances of three Dynamic Factor Models on a large monthly data panel of macroeconomic and financial time series for the UE economy. The first model relies on static principal-component and was introduced by Stock and Watson (2002a, b. The second is based on generalized principal components and it was introduced by Forni, Hallin, Lippi and Reichlin (2000, 2005. The last model has been recently proposed by Forni, Hallin, Lippi and Zaffaroni (2015, 2016. The data panel is split into two parts: the calibration sample, from February 1986 to December 2000, is used to select the most performing specification for each class of models in a in- sample environment, and the proper sample, from January 2001 to November 2015, is used to compare the performances of the selected models in an out-of-sample environment. The metholodogical approach is analogous to Forni, Giovannelli, Lippi and Soccorsi (2016, but also the size of the rolling window is empirically estimated in the calibration process to achieve more robustness. We find that, on the proper sample, the last model is the most performing for the Inflation. However, mixed evidencies appear over the proper sample for the Industrial Production.

  6. Creating lift versus building the base : Current trends in marketing dynamics

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Bijmolt, T.H.A.; van Doorn, J.; Hanssens, D.M.; van Heerde, H.J.; Verhoef, P.C.; Wieringa, J.E.

    Markets are dynamic by nature; and marketing-efforts can be directed to stimulate, reduce, or to utilize these dynamics. The field of marketing dynamics aims at modeling the effects of marketing actions and policies on short-term performance ("lift") and on long-term performance ("base"). One of the

  7. An individual-based model of Zebrafish population dynamics accounting for energy dynamics

    DEFF Research Database (Denmark)

    Beaudouin, Remy; Goussen, Benoit; Piccini, Benjamin

    2015-01-01

    Developing population dynamics models for zebrafish is crucial in order to extrapolate from toxicity data measured at the organism level to biological levels relevant to support and enhance ecological risk assessment. To achieve this, a dynamic energy budget for individual zebrafish (DEB model...

  8. Discrete opinion dynamics on networks based on social influence

    International Nuclear Information System (INIS)

    Hu Haibo; Wang Xiaofan

    2009-01-01

    A model of opinion dynamics based on social influence on networks was studied. The opinion of each agent can have integer values i = 1, 2, ..., I and opinion exchanges are restricted to connected agents. It was found that for any I ≥ 2 and self-confidence parameter 0 ≤ u i ) of the population that hold a given opinion i is a martingale, and the fraction q i of opinion i will gradually converge to (q i ). The tendency can slow down with the increase of degree assortativity of networks. When u is degree dependent, (q i ) does not possess the martingale property, however q i still converges to it. In both cases for a finite network the states of all agents will finally reach consensus. Further if there exist stubborn persons in the population whose opinions do not change over time, it was found that for degree-independent constant u, both q i and (q i ) will converge to fixed proportions which only depend on the distribution of initial obstinate persons, and naturally the final equilibrium state will be the coexistence of diverse opinions held by the stubborn people. The analytical results were verified by numerical simulations on Barabasi-Albert (BA) networks. The model highlights the influence of high-degree agents on the final consensus or coexistence state and captures some realistic features of the diffusion of opinions in social networks

  9. Electron accommodation dynamics in the DNA base thymine

    Science.gov (United States)

    King, Sarah B.; Stephansen, Anne B.; Yokoi, Yuki; Yandell, Margaret A.; Kunin, Alice; Takayanagi, Toshiyuki; Neumark, Daniel M.

    2015-07-01

    The dynamics of electron attachment to the DNA base thymine are investigated using femtosecond time-resolved photoelectron imaging of the gas phase iodide-thymine (I-T) complex. An ultraviolet pump pulse ejects an electron from the iodide and prepares an iodine-thymine temporary negative ion that is photodetached with a near-IR probe pulse. The resulting photoelectrons are analyzed with velocity-map imaging. At excitation energies ranging from -120 meV to +90 meV with respect to the vertical detachment energy (VDE) of 4.05 eV for I-T, both the dipole-bound and valence-bound negative ions of thymine are observed. A slightly longer rise time for the valence-bound state than the dipole-bound state suggests that some of the dipole-bound anions convert to valence-bound species. No evidence is seen for a dipole-bound anion of thymine at higher excitation energies, in the range of 0.6 eV above the I-T VDE, which suggests that if the dipole-bound anion acts as a "doorway" to the valence-bound anion, it only does so at excitation energies near the VDE of the complex.

  10. Electron accommodation dynamics in the DNA base thymine

    Energy Technology Data Exchange (ETDEWEB)

    King, Sarah B.; Yandell, Margaret A.; Kunin, Alice [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Stephansen, Anne B. [Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 København Ø (Denmark); Yokoi, Yuki; Takayanagi, Toshiyuki [Department of Chemistry, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama City, Saitama 338-8570 (Japan); Neumark, Daniel M., E-mail: dneumark@berkeley.edu [Department of Chemistry, University of California, Berkeley, California 94720 (United States); Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2015-07-14

    The dynamics of electron attachment to the DNA base thymine are investigated using femtosecond time-resolved photoelectron imaging of the gas phase iodide-thymine (I{sup −}T) complex. An ultraviolet pump pulse ejects an electron from the iodide and prepares an iodine-thymine temporary negative ion that is photodetached with a near-IR probe pulse. The resulting photoelectrons are analyzed with velocity-map imaging. At excitation energies ranging from −120 meV to +90 meV with respect to the vertical detachment energy (VDE) of 4.05 eV for I{sup −}T, both the dipole-bound and valence-bound negative ions of thymine are observed. A slightly longer rise time for the valence-bound state than the dipole-bound state suggests that some of the dipole-bound anions convert to valence-bound species. No evidence is seen for a dipole-bound anion of thymine at higher excitation energies, in the range of 0.6 eV above the I{sup −}T VDE, which suggests that if the dipole-bound anion acts as a “doorway” to the valence-bound anion, it only does so at excitation energies near the VDE of the complex.

  11. Early Seizure Detection Based on Cardiac Autonomic Regulation Dynamics

    Directory of Open Access Journals (Sweden)

    Jonatas Pavei

    2017-10-01

    Full Text Available Epilepsy is a neurological disorder that causes changes in the autonomic nervous system. Heart rate variability (HRV reflects the regulation of cardiac activity and autonomic nervous system tone. The early detection of epileptic seizures could foster the use of new treatment approaches. This study presents a new methodology for the prediction of epileptic seizures using HRV signals. Eigendecomposition of HRV parameter covariance matrices was used to create an input for a support vector machine (SVM-based classifier. We analyzed clinical data from 12 patients (9 female; 3 male; age 34.5 ± 7.5 years, involving 34 seizures and a total of 55.2 h of interictal electrocardiogram (ECG recordings. Data from 123.6 h of ECG recordings from healthy subjects were used to test false positive rate per hour (FP/h in a completely independent data set. Our methodological approach allowed the detection of impending seizures from 5 min to just before the onset of a clinical/electrical seizure with a sensitivity of 94.1%. The FP rate was 0.49 h−1 in the recordings from patients with epilepsy and 0.19 h−1 in the recordings from healthy subjects. Our results suggest that it is feasible to use the dynamics of HRV parameters for the early detection and, potentially, the prediction of epileptic seizures.

  12. POTENTIALS OF IMAGE BASED ACTIVE RANGING TO CAPTURE DYNAMIC SCENES

    Directory of Open Access Journals (Sweden)

    B. Jutzi

    2012-09-01

    Full Text Available Obtaining a 3D description of man-made and natural environments is a basic task in Computer Vision and Remote Sensing. To this end, laser scanning is currently one of the dominating techniques to gather reliable 3D information. The scanning principle inherently needs a certain time interval to acquire the 3D point cloud. On the other hand, new active sensors provide the possibility of capturing range information by images with a single measurement. With this new technique image-based active ranging is possible which allows capturing dynamic scenes, e.g. like walking pedestrians in a yard or moving vehicles. Unfortunately most of these range imaging sensors have strong technical limitations and are not yet sufficient for airborne data acquisition. It can be seen from the recent development of highly specialized (far-range imaging sensors – so called flash-light lasers – that most of the limitations could be alleviated soon, so that future systems will be equipped with improved image size and potentially expanded operating range. The presented work is a first step towards the development of methods capable for application of range images in outdoor environments. To this end, an experimental setup was set up for investigating these proposed possibilities. With the experimental setup a measurement campaign was carried out and first results will be presented within this paper.

  13. Dynamically fluctuating electric dipole moments in fullerene-based magnets.

    Science.gov (United States)

    Kambe, Takashi; Oshima, Kokichi

    2014-09-19

    We report here the direct evidence of the existence of a permanent electric dipole moment in both crystal phases of a fullerene-based magnet--the ferromagnetic α-phase and the antiferromagnetic α'-phase of tetra-kis-(dimethylamino)-ethylene-C60 (TDAE-C60)--as determined by dielectric measurements. We propose that the permanent electric dipole originates from the pairing of a TDAE molecule with surrounding C60 molecules. The two polymorphs exhibit clear differences in their dielectric responses at room temperature and during the freezing process with dynamically fluctuating electric dipole moments, although no difference in their room-temperature structures has been previously observed. This result implies that two polymorphs have different local environment around the molecules. In particular, the ferromagnetism of the α-phase is founded on the homogeneous molecule displacement and orientational ordering. The formation of the different phases with respect to the different rotational states in the Jahn-Teller distorted C60s is also discussed.

  14. Enabling full field physics based OPC via dynamic model generation

    Science.gov (United States)

    Lam, Michael; Clifford, Chris; Raghunathan, Ananthan; Fenger, Germain; Adam, Kostas

    2017-03-01

    As EUV lithography marches closer to reality for high volume production, its peculiar modeling challenges related to both inter- and intra- field effects has necessitated building OPC infrastructure that operates with field position dependency. Previous state of the art approaches to modeling field dependency used piecewise constant models where static input models are assigned to specific x/y-positions within the field. OPC and simulation could assign the proper static model based on simulation-level placement. However, in the realm of 7nm and 5nm feature sizes, small discontinuities in OPC from piecewise constant model changes can cause unacceptable levels of EPE errors. The introduction of Dynamic Model Generation (DMG) can be shown to effectively avoid these dislocations by providing unique mask and optical models per simulation region, allowing a near continuum of models through field. DMG allows unique models for EMF, apodization, aberrations, etc to vary through the entire field and provides a capability to precisely and accurately model systematic field signatures.

  15. Description of children identified as suffering from MAM in Bangladesh: Varying results based on case definitions

    International Nuclear Information System (INIS)

    Waid, Jillian

    2014-01-01

    Full text: Background: There is a wide discrepancy between the proportion of children classified as acutely malnourished when MUAC criteria are used compared to weight for height. This has greatly complicated setting targets for the coverage of SAM and MAM programs in Bangladesh. This difference is much larger for children identified with MAM than for those with SAM, largely because identification as MAM can overlap both with SAM and with children not identified as acutely malnourished. Objective: To review existing data sets in order to determine the relationship between MUAC and other anthropometric measures, helping to provide a better understanding of the implications of different admission criteria to therapeutic and supplementary feeding programs. Methodology: This study uses data collected through national nutritional surveillance projects over multiple seasons in Bangladesh. For the years 1990 to 2006, sub-samples of data from the Nutritional Surveillance Project were pulled from areas of the country that remained constant over a set period. Data from 2010 to 2012 was pulled from the Food Security and Nutrition Surveillance Project. Case definition: Cases of moderate acute malnutrition were identified using MUAC- for-age z-scores (-3>z-score>-2), MUAC cut-offs (115mm>MUAC>125mm), and weight-for-height z-scores (-3>z-score>-2). Results: In all years more than 50% of all children identified as moderately malnourished were classified as such by only one measure (1990 selected sub-districts: 52%, 2012 national sample: 69%) In 1990 a higher proportion of children were categorized as moderately malnourished based on MUAC-for-age z-scores than by weight for height z-scores, but since 2000 the opposite has been true. This change is closely tied to the increasing height of children sampled, due to the declining rates of stunting in the country. After controlling for age and weight-for-height z-scores, an increase in height of one cm was associated with an increase

  16. Evidence-Based Design and Research-Informed Design: What's the Difference? Conceptual Definitions and Comparative Analysis.

    Science.gov (United States)

    Peavey, Erin; Vander Wyst, Kiley B

    2017-10-01

    This article provides critical examination and comparison of the conceptual meaning and underlying assumptions of the concepts evidence-based design (EBD) and research-informed design (RID) in order to facilitate practical use and theoretical development. In recent years, EBD has experienced broad adoption, yet it has been simultaneously critiqued for rigidity and misapplication. Many practitioners are gravitating to the term RID to describe their method of integrating knowledge into the design process. However, the term RID lacks a clear definition and the blurring of terms has the potential to weaken advances made integrating research into practice. Concept analysis methods from Walker and Avant were used to define the concepts for comparison. Conceptual definitions, process descriptions, examples (i.e., model cases), and methods of evaluation are offered for EBD and RID. Although EBD and RID share similarities in meaning, the two terms are distinct. When comparing evidence based (EB) and research informed, EB is a broad base of information types (evidence) that are narrowly applied (based), while the latter references a narrow slice of information (research) that is broadly applied (informed) to create an end product of design. Much of the confusion between the use of the concepts EBD and RID arises out of differing perspectives between the way practitioners and academics understand the underlying terms. The authors hope this article serves to generate thoughtful dialogue, which is essential to the development of a discipline, and look forward to the contribution of the readership.

  17. Dynamic combinatorial libraries based on hydrogen-bonde molecular boxes

    NARCIS (Netherlands)

    Kerckhoffs, J.M.C.A.; Mateos timoneda, Miguel; Reinhoudt, David; Crego Calama, Mercedes

    2007-01-01

    This article describes two different types of dynamic combinatorial libraries of host and guest molecules. The first part of this article describes the encapsulation of alizarin trimer 2 a3 by dynamic mixtures of up to twenty different self-assembled molecular receptors together with the

  18. Language-Based Caching of Dynamically Generated HTML

    DEFF Research Database (Denmark)

    Brabrand, Claus; Møller, Anders; Olesen, Steffan

    2002-01-01

    Increasingly, HTML documents are dynamically generated by interactive Web services. To ensure that the client is presented with the newest versions of such documents it is customary to disable client caching causing a seemingly inevitable performance penalty. In the system, dynamic HTML documents...

  19. Research on Generating Method of Embedded Software Test Document Based on Dynamic Model

    Science.gov (United States)

    Qu, MingCheng; Wu, XiangHu; Tao, YongChao; Liu, Ying

    2018-03-01

    This paper provides a dynamic model-based test document generation method for embedded software that provides automatic generation of two documents: test requirements specification documentation and configuration item test documentation. This method enables dynamic test requirements to be implemented in dynamic models, enabling dynamic test demand tracking to be easily generated; able to automatically generate standardized, standardized test requirements and test documentation, improved document-related content inconsistency and lack of integrity And other issues, improve the efficiency.

  20. Effect of Disease Definition on Perceived Burden of Acute Respiratory Infections in Children: A Prospective Cohort Study Based on Symptom Diaries.

    Science.gov (United States)

    Zoch, Beate; Günther, Annette; Karch, André; Mikolajczyk, Rafael

    2017-10-01

    Acute respiratory infections (ARIs) are among the most frequent childhood diseases in Western countries. Assessment of ARI episodes for research purposes is usually based on parent-administered retrospective questionnaires or prospective symptom diaries. The aim of our analysis was to compare the effect of ARI definitions on the corresponding disease burden in a prospective cohort study using symptom diaries. A literature search was performed to identify definitions of ARI used in research studies. The definitions were applied to a symptom diary dataset from a cohort study of 1-3-year-old children conducted in the winter season 2013/2014. We compared the total number of ARI episodes, the total number of days with ARI and the median and mean duration of ARI episodes resulting from the use of the different definitions. Six ARI definitions were identified in the literature. Depending on ARI definition, the total number of ARI episodes and the total number of days with ARI in our dataset varied by a factor of 1.69 and 1.53, respectively, between the lowest and the highest. The median duration of the episodes ranged from 7 to 10 days. Different definitions led to considerable differences in the number and duration of ARI episodes, making direct comparisons of studies with different methods questionable. We propose the use of a standardized ARI definition in upcoming cohort studies working with diary data. This process could be conducted using a Delphi survey with experts in this study field.

  1. Risk stratification of periprocedural myocardial infarction after percutaneous coronary intervention: Analysis based on the SCAI definition.

    Science.gov (United States)

    Zhang, Dong; Li, Yiping; Yin, Dong; He, Yuan; Chen, Changzhe; Song, Chenxi; Yan, Ruohua; Zhu, Chen'gang; Xu, Bo; Dou, Kefei

    2017-03-01

    To investigate the predictors of and generate a risk prediction method for periprocedural myocardial infarction (PMI) after percutaneous coronary intervention (PCI) using the new PMI definition proposed by the Society for Cardiovascular Angiography and Interventions (SCAI). The SCAI-defined PMI was found to be associated with worse prognosis than the PMI diagnosed by other definitions. However, few large-sample studies have attempted to predict the risk of SCAI-defined PMI. A total of 3,371 patients (3,516 selective PCIs) were included in this single-center retrospective analysis. The diagnostic criteria for PMI were set according to the SCAI definition. All clinical characteristics, coronary angiography findings and PCI procedural factors were collected. Multivariate logistic regression analysis was performed to identify independent predictors of PMI. To evaluate the risk of PMI, a multivariable risk score (PMI score) was constructed with incremental weights attributed to each component variable according to their estimated coefficients. PMI occurred in 108 (3.1%) of all patients. Age, multivessel treatment, at least one bifurcation treatment and total treated lesion length were independent predictors of SCAI-defined PMI. PMI scores ranged from 0 to 20. The C-statistic of PMI score was 0.71 (95% confidence interval: 0.66-0.76). PMI rates increased significantly from 1.96% in the non-high-risk group (PMI score < 10) to 6.26% in the high-risk group (PMI score ≥ 10) (P < 0.001). Age, multivessel treatment, at least one bifurcation treatment, and total treated lesion length are predictive of PMI. The PMI score could help identify patients at high risk of PMI after PCI. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Optimal definition of inter-residual contact in globular proteins based on pairwise interaction energy calculations, its robustness, and applications.

    Science.gov (United States)

    Fačkovec, Boris; Vondrášek, Jiří

    2012-10-25

    Although a contact is an essential measurement for the topology as well as strength of non-covalent interactions in biomolecules and their complexes, there is no general agreement in the definition of this feature. Most of the definitions work with simple geometric criteria which do not fully reflect the energy content or ability of the biomolecular building blocks to arrange their environment. We offer a reasonable solution to this problem by distinguishing between "productive" and "non-productive" contacts based on their interaction energy strength and properties. We have proposed a method which converts the protein topology into a contact map that represents interactions with statistically significant high interaction energies. We do not prove that these contacts are exclusively stabilizing, but they represent a gateway to thermodynamically important rather than geometry-based contacts. The process is based on protein fragmentation and calculation of interaction energies using the OPLS force field and relies on pairwise additivity of amino acid interactions. Our approach integrates the treatment of different types of interactions, avoiding the problems resulting from different contributions to the overall stability and the different effect of the environment. The first applications on a set of homologous proteins have shown the usefulness of this classification for a sound estimate of protein stability.

  3. Hiding Techniques for Dynamic Encryption Text based on Corner Point

    Science.gov (United States)

    Abdullatif, Firas A.; Abdullatif, Alaa A.; al-Saffar, Amna

    2018-05-01

    Hiding technique for dynamic encryption text using encoding table and symmetric encryption method (AES algorithm) is presented in this paper. The encoding table is generated dynamically from MSB of the cover image points that used as the first phase of encryption. The Harris corner point algorithm is applied on cover image to generate the corner points which are used to generate dynamic AES key to second phase of text encryption. The embedded process in the LSB for the image pixels except the Harris corner points for more robust. Experimental results have demonstrated that the proposed scheme have embedding quality, error-free text recovery, and high value in PSNR.

  4. A Low-Cost PC-Based Image Workstation for Dynamic Interactive Display of Three-Dimensional Anatomy

    Science.gov (United States)

    Barrett, William A.; Raya, Sai P.; Udupa, Jayaram K.

    1989-05-01

    A system for interactive definition, automated extraction, and dynamic interactive display of three-dimensional anatomy has been developed and implemented on a low-cost PC-based image workstation. An iconic display is used for staging predefined image sequences through specified increments of tilt and rotation over a solid viewing angle. Use of a fast processor facilitates rapid extraction and rendering of the anatomy into predefined image views. These views are formatted into a display matrix in a large image memory for rapid interactive selection and display of arbitrary spatially adjacent images within the viewing angle, thereby providing motion parallax depth cueing for efficient and accurate perception of true three-dimensional shape, size, structure, and spatial interrelationships of the imaged anatomy. The visual effect is that of holding and rotating the anatomy in the hand.

  5. Definition of onset in the development of onset-based alcoholism typologies.

    Science.gov (United States)

    Parrella, D P; Filstead, W J

    1988-01-01

    Age of onset of alcoholism is gaining prominence as an explanatory construct in the development of models of alcoholism. Recently, at least one investigator has cited its potential as a simple means for deriving a typological classification scheme that could have great impact, both in terms of future research and in devising treatment strategies. Various investigators, however, operationalize alcoholism onset in different ways. By comparing five definitions of the concept, we show that the proportion of individuals classified as early or late onset can vary dramatically, depending on the interpretation given to phrases such as "subjective problems." Gender differences in early-late proportions are demonstrated, and the statistical relationship of the five items used as onset indicators is described. We suggest that collecting multiple convergent definitions of onset constitutes a structured recall aid that may ameliorate some of the problems to which self-report data are subject, while additionally providing the data necessary to create an aggregate measure that will increase reliability in comparison with the items individually. Finally, we encourage description of alcoholism onset as a developmental process rather than a single event, and urge investigators to increased precision in the operationalization of this construct as research in this area progresses.

  6. A dynamic case definition is warranted for adequate notification in an extended epidemic setting: the Dutch Q fever outbreak 2007-2009 as exemplar.

    Science.gov (United States)

    Jaramillo-Gutierrez, G; Wegdam-Blans, M C; ter Schegget, R; Korbeeck, J M; van Aken, R; Bijlmer, H A; Tjhie, J H; Koopmans, M P

    2013-10-10

    Q fever is a notifiable disease in the Netherlands:laboratories are obliged to notify possible cases to the Municipal Health Services. These services then try to reconfirm cases with additional clinical and epidemiological data and provide anonymised reports to the national case register of notifiable diseases. Since the start of the 2007–2009 Dutch Q fever outbreak,notification rules remained unchanged, despite new laboratory insights and altered epidemiology. In this study, we retrospectively analysed how these changes influenced the proportion of laboratory-defined acute Q fever cases (confirmed, probable and possible)that were included in the national case register, during(2009) and after the outbreak (2010 and 2011).The number of laboratory-defined cases notified to the Municipal Health Services was 377 in 2009, 96 in 2010 and 50 in 2011. Of these, 186 (49.3%) in 2009, 12(12.5%) in 2010 and 9 (18.0%) in 2011 were confirmed as acute infection by laboratory interpretation. The proportion of laboratory-defined acute Q fever cases that was reconfirmed by the Municipal Health Services and that were included in the national case register decreased from 90% in 2009, to 22% and 24% in 2010 and 2011, respectively. The decrease was observed in all categories of cases, including those considered to be confirmed by laboratory criteria. Continued use ofa pre-outbreak case definition led to over-reporting of cases to the Municipal Health Services in the post-epidemic years. Therefore we recommend dynamic laboratory notification rules, by reviewing case definitions periodically in an ongoing epidemic, as in the Dutch Q fever outbreak.

  7. Definition of treatment response in rheumatoid arthritis based on the simplified and the clinical disease activity index.

    Science.gov (United States)

    Aletaha, Daniel; Martinez-Avila, Jose; Kvien, Tore K; Smolen, Josef S

    2012-07-01

    The simplified disease activity index (SDAI) and the clinical disease activity index (CDAI) are established instruments to measure disease activity in rheumatoid arthritis (RA). To date, no validated response definitions for the SDAI and CDAI are available. The authors aimed to define minor, moderate and major response criteria for the SDAI. The authors used data from two clinical trials on infliximab versus methotrexate in early (ASPIRE) or established (ATTRACT) RA, and identified the three SDAI cutpoints based on the best agreement (by κ statistics) with the American College of Rheumatology (ACR)20/50/70 responses. Cutpoints were then tested for different aspects of validity in the trial datasets and in a Norwegian disease modifying antirheumatic drug prescription dataset (NOR-DMARD). Based on agreement with the ACR response, the minor, moderate and major responses were identified as SDAI 50%, 70% and 85% improvement. These cutpoints had good face validity concerning the disease activity states achieved by the different response definitions. Construct validity was shown by a clear association of increasing SDAI response categories with increasing levels of functional improvement, achievement of better functional states and lower annual radiographic progression. Across SDAI 50/70/85, the sensitivities regarding a patient-perceived improvement decreased (73%/39%/22%) and the specificities increased (61%/89%/96%) in a meaningful way. Further, the cutpoints discriminated the different treatment arms in ASPIRE and ATTRACT. The same cutpoints were used for the CDAI, with similar results in the validation analyses. These new response criteria expand the usefulness of the SDAI and CDAI for their use as endpoints in clinical trials beyond the definition of disease activity categories.

  8. Sensor-Based Activity Recognition with Dynamically Added Context

    Directory of Open Access Journals (Sweden)

    Jiahui Wen

    2015-08-01

    Full Text Available An activity recognition system essentially processes raw sensor data and maps them into latent activity classes. Most of the previous systems are built with supervised learning techniques and pre-defined data sources, and result in static models. However, in realistic and dynamic environments, original data sources may fail and new data sources become available, a robust activity recognition system should be able to perform evolution automatically with dynamic sensor availability in dynamic environments. In this paper, we propose methods that automatically incorporate dynamically available data sources to adapt and refine the recognition system at run-time. The system is built upon ensemble classifiers which can automatically choose the features with the most discriminative power. Extensive experimental results with publicly available datasets demonstrate the effectiveness of our methods.

  9. Dynamic imaging through turbid media based on digital holography.

    Science.gov (United States)

    Li, Shiping; Zhong, Jingang

    2014-03-01

    Imaging through turbid media using visible or IR light instead of harmful x ray is still a challenging problem, especially in dynamic imaging. A method of dynamic imaging through turbid media using digital holography is presented. In order to match the coherence length between the dynamic object wave and the reference wave, a cw laser is used. To solve the problem of difficult focusing in imaging through turbid media, an autofocus technology is applied. To further enhance the image contrast, a spatial filtering technique is used. A description of digital holography and experiments of imaging the objects hidden in turbid media are presented. The experimental result shows that dynamic images of the objects can be achieved by the use of digital holography.

  10. Discrete opinion dynamics on networks based on social influence

    Energy Technology Data Exchange (ETDEWEB)

    Hu Haibo; Wang Xiaofan [Complex Networks and Control Lab, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2009-06-05

    A model of opinion dynamics based on social influence on networks was studied. The opinion of each agent can have integer values i = 1, 2, ..., I and opinion exchanges are restricted to connected agents. It was found that for any I {>=} 2 and self-confidence parameter 0 {<=} u < 1, when u is a degree-independent constant, the weighted proportion (q{sub i}) of the population that hold a given opinion i is a martingale, and the fraction q{sub i} of opinion i will gradually converge to (q{sub i}). The tendency can slow down with the increase of degree assortativity of networks. When u is degree dependent, (q{sub i}) does not possess the martingale property, however q{sub i} still converges to it. In both cases for a finite network the states of all agents will finally reach consensus. Further if there exist stubborn persons in the population whose opinions do not change over time, it was found that for degree-independent constant u, both q{sub i} and (q{sub i}) will converge to fixed proportions which only depend on the distribution of initial obstinate persons, and naturally the final equilibrium state will be the coexistence of diverse opinions held by the stubborn people. The analytical results were verified by numerical simulations on Barabasi-Albert (BA) networks. The model highlights the influence of high-degree agents on the final consensus or coexistence state and captures some realistic features of the diffusion of opinions in social networks.

  11. A particle based simulation model for glacier dynamics

    Directory of Open Access Journals (Sweden)

    J. A. Åström

    2013-10-01

    Full Text Available A particle-based computer simulation model was developed for investigating the dynamics of glaciers. In the model, large ice bodies are made of discrete elastic particles which are bound together by massless elastic beams. These beams can break, which induces brittle behaviour. At loads below fracture, beams may also break and reform with small probabilities to incorporate slowly deforming viscous behaviour in the model. This model has the advantage that it can simulate important physical processes such as ice calving and fracturing in a more realistic way than traditional continuum models. For benchmarking purposes the deformation of an ice block on a slip-free surface was compared to that of a similar block simulated with a Finite Element full-Stokes continuum model. Two simulations were performed: (1 calving of an ice block partially supported in water, similar to a grounded marine glacier terminus, and (2 fracturing of an ice block on an inclined plane of varying basal friction, which could represent transition to fast flow or surging. Despite several approximations, including restriction to two-dimensions and simplified water-ice interaction, the model was able to reproduce the size distributions of the debris observed in calving, which may be approximated by universal scaling laws. On a moderate slope, a large ice block was stable and quiescent as long as there was enough of friction against the substrate. For a critical length of frictional contact, global sliding began, and the model block disintegrated in a manner suggestive of a surging glacier. In this case the fragment size distribution produced was typical of a grinding process.

  12. Vision-based threat detection in dynamic environments.

    Energy Technology Data Exchange (ETDEWEB)

    Carlson, Jeffrey J.

    2007-08-01

    This report addresses the development of automated video-screening technology to assist security forces in protecting our homeland against terrorist threats. A prevailing threat is the covert placement of bombs inside crowded public facilities. Although video-surveillance systems are increasingly common, current systems cannot detect the placement of bombs. It is also unlikely that security personnel could detect a bomb or its placement by observing video from surveillance cameras. The problems lie in the large number of cameras required to monitor large areas, the limited number of security personnel employed to protect these areas, and the intense diligence required to effectively screen live video from even a single camera. Different from existing video-detection systems designed to operate in nearly static environments, we are developing technology to detect changes in the background of dynamic environments: environments where motion and human activities are persistent over long periods. Our goal is to quickly detect background changes, even if the background is visible to the camera less than 5 percent of the time and possibly never free from foreground activity. Our approach employs statistical scene models based on mixture densities. We hypothesized that the background component of the mixture has a small variance compared to foreground components. Experiments demonstrate this hypothesis is true under a wide variety of operating conditions. A major focus involved the development of robust background estimation techniques that exploit this property. We desire estimation algorithms that can rapidly produce accurate background estimates and detection algorithms that can reliably detect background changes with minimal nuisance alarms. Another goal is to recognize unusual activities or foreground conditions that could signal an attack (e.g., large numbers of running people, people falling to the floor, etc.). Detection of background changes and/or unusual

  13. A Dual-Based Procedure for Dynamic Facility Location

    OpenAIRE

    Tony J. Van Roy; Donald Erlenkotter

    1982-01-01

    In dynamic facility location problems, one desires to select the time-staged establishment of facilities at different locations so as to minimize the total discounted costs for meeting demands specified over time at various customer locations. We formulate a particular dynamic facility location problem as a combinatorial optimization problem. The formulation permits both the opening of new facilities and the closing of existing ones. A branch-and-bound procedure incorporating a dual ascent me...

  14. Transient Dynamics Analysis of The Reachstacker Speader Based On ANSYS

    Directory of Open Access Journals (Sweden)

    Shu Yu Feng

    2016-01-01

    Full Text Available Reachstacker is an indispensable handling machinery, it will inevitably lead to unbalanced force at the job site. This paper does transient dynamics analysis for the spreader mechanism, which is one of the most significance key components. We get dynamic response of the spreader in lifting instant, results not only provide a reference for designers to understand the mechanical characteristics of spreader comprehensively, but also bedding for the future research.

  15. A Satellite-Based Lagrangian View on Phytoplankton Dynamics

    Science.gov (United States)

    Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan

    2018-01-01

    The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter—the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this Lagrangian perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the Lagrangian view of phytoplankton dynamics.

  16. A Total Variation-Based Reconstruction Method for Dynamic MRI

    Directory of Open Access Journals (Sweden)

    Germana Landi

    2008-01-01

    Full Text Available In recent years, total variation (TV regularization has become a popular and powerful tool for image restoration and enhancement. In this work, we apply TV minimization to improve the quality of dynamic magnetic resonance images. Dynamic magnetic resonance imaging is an increasingly popular clinical technique used to monitor spatio-temporal changes in tissue structure. Fast data acquisition is necessary in order to capture the dynamic process. Most commonly, the requirement of high temporal resolution is fulfilled by sacrificing spatial resolution. Therefore, the numerical methods have to address the issue of images reconstruction from limited Fourier data. One of the most successful techniques for dynamic imaging applications is the reduced-encoded imaging by generalized-series reconstruction method of Liang and Lauterbur. However, even if this method utilizes a priori data for optimal image reconstruction, the produced dynamic images are degraded by truncation artifacts, most notably Gibbs ringing, due to the spatial low resolution of the data. We use a TV regularization strategy in order to reduce these truncation artifacts in the dynamic images. The resulting TV minimization problem is solved by the fixed point iteration method of Vogel and Oman. The results of test problems with simulated and real data are presented to illustrate the effectiveness of the proposed approach in reducing the truncation artifacts of the reconstructed images.

  17. A Satellite-Based Lagrangian View on Phytoplankton Dynamics.

    Science.gov (United States)

    Lehahn, Yoav; d'Ovidio, Francesco; Koren, Ilan

    2018-01-03

    The well-lit upper layer of the open ocean is a dynamical environment that hosts approximately half of global primary production. In the remote parts of this environment, distant from the coast and from the seabed, there is no obvious spatially fixed reference frame for describing the dynamics of the microscopic drifting organisms responsible for this immense production of organic matter-the phytoplankton. Thus, a natural perspective for studying phytoplankton dynamics is to follow the trajectories of water parcels in which the organisms are embedded. With the advent of satellite oceanography, this Lagrangian perspective has provided valuable information on different aspects of phytoplankton dynamics, including bloom initiation and termination, spatial distribution patterns, biodiversity, export of carbon to the deep ocean, and, more recently, bottom-up mechanisms that affect the distribution and behavior of higher-trophic-level organisms. Upcoming submesoscale-resolving satellite observations and swarms of autonomous platforms open the way to the integration of vertical dynamics into the Lagrangian view of phytoplankton dynamics.

  18. A new definition for the mole based on the Avogadro constant: a journey from physics to chemistry.

    Science.gov (United States)

    Milton, Martin J T

    2011-10-28

    The mole is the most recent addition to the set of base units that form the International System of Units, although its pre-cursor the 'gram-molecule', had been in use by both physicists and chemists for more than 120 years. A proposal has been published recently to establish a new definition for the mole based on a fixed value for the Avogadro constant. This would introduce consistent relative uncertainties for the molar and the atomic masses while making no change to the system of relative atomic masses ('atomic weights'). Although the proposal would have little impact on the measurement uncertainty of practical work, it has stimulated considerable debate about the mole and the nature of the quantity amount of substance. In this paper, the rationale for the new definition is explained against the background of changes in the way the quantity amount of substance has been used, from its first use during the early development of thermodynamics through to the use of the 'number of gram-molecules' at the end of the nineteenth century.

  19. A screw-based dynamic balancing approach, applied to a 5-bar mechanism

    NARCIS (Netherlands)

    de Jong, Jan Johannes; van Dijk, Johannes; Herder, Justus Laurens; Lenarcic, Jadran; Merlet, Jean-Pierre

    2016-01-01

    Dynamic balancing aims to reduce or eliminate the shaking base reaction forces and moments of mechanisms, in order to minimize vibration and wear. The derivation of the dynamic balance conditions requires significant algebraic effort, even for simple mechanisms. In this study, a screw-based

  20. Web-based Toolkit for Dynamic Generation of Data Processors

    Science.gov (United States)

    Patel, J.; Dascalu, S.; Harris, F. C.; Benedict, K. K.; Gollberg, G.; Sheneman, L.

    2011-12-01

    All computation-intensive scientific research uses structured datasets, including hydrology and all other types of climate-related research. When it comes to testing their hypotheses, researchers might use the same dataset differently, and modify, transform, or convert it to meet their research needs. Currently, many researchers spend a good amount of time performing data processing and building tools to speed up this process. They might routinely repeat the same process activities for new research projects, spending precious time that otherwise could be dedicated to analyzing and interpreting the data. Numerous tools are available to run tests on prepared datasets and many of them work with datasets in different formats. However, there is still a significant need for applications that can comprehensively handle data transformation and conversion activities and help prepare the various processed datasets required by the researchers. We propose a web-based application (a software toolkit) that dynamically generates data processors capable of performing data conversions, transformations, and customizations based on user-defined mappings and selections. As a first step, the proposed solution allows the users to define various data structures and, in the next step, can select various file formats and data conversions for their datasets of interest. In a simple scenario, the core of the proposed web-based toolkit allows the users to define direct mappings between input and output data structures. The toolkit will also support defining complex mappings involving the use of pre-defined sets of mathematical, statistical, date/time, and text manipulation functions. Furthermore, the users will be allowed to define logical cases for input data filtering and sampling. At the end of the process, the toolkit is designed to generate reusable source code and executable binary files for download and use by the scientists. The application is also designed to store all data

  1. Can a science-based definition of acupuncture improve clinical outcomes?

    Science.gov (United States)

    Priebe, Ted; Stumpf, Steven H; Zalunardo, Rod

    2017-05-01

    Research on acupuncture has been muddled by attempts to bridge the ancient with the modern. Barriers to effectiveness research are reflected in recurring conflicts that include disagreement on use of the most basic terms, lack of standard intervention controls, and the absence of functional measures for assessing treatment effect. Acupuncture research has stalled at the "placebo barrier" wherein acupuncture is "no better than placebo." The most widely recognized comparative effectiveness research in acupuncture does not compare acupuncture treatment protocols within groups, thereby, mutating large scale effectiveness studies into large scale efficacy trials. Too often research in acupuncture attempts to tie outcomes to traditional belief systems thereby limiting usefulness of the research. The acupuncture research paradigm needs to focus more closely on a scientific definition of treatments and outcomes that compare protocols in terms of prevalent clinical issues such as relative effectiveness for treating pain.

  2. Transmission probability-based dynamic power control for multi-radio mesh networks

    CSIR Research Space (South Africa)

    Olwal, TO

    2008-09-01

    Full Text Available This paper presents an analytical model for the selection of the transmission power based on the bi-directional medium access information. Most of dynamic transmission power control algorithms are based on the single directional channel...

  3. Efficient Kinect Sensor-Based Reactive Path Planning Method for Autonomous Mobile Robots in Dynamic Environments

    Energy Technology Data Exchange (ETDEWEB)

    Tuvshinjargal, Doopalam; Lee, Deok Jin [Kunsan National University, Gunsan (Korea, Republic of)

    2015-06-15

    In this paper, an efficient dynamic reactive motion planning method for an autonomous vehicle in a dynamic environment is proposed. The purpose of the proposed method is to improve the robustness of autonomous robot motion planning capabilities within dynamic, uncertain environments by integrating a virtual plane-based reactive motion planning technique with a sensor fusion-based obstacle detection approach. The dynamic reactive motion planning method assumes a local observer in the virtual plane, which allows the effective transformation of complex dynamic planning problems into simple stationary ones proving the speed and orientation information between the robot and obstacles. In addition, the sensor fusion-based obstacle detection technique allows the pose estimation of moving obstacles using a Kinect sensor and sonar sensors, thus improving the accuracy and robustness of the reactive motion planning approach. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles in hostile dynamic environments.

  4. Efficient Kinect Sensor-Based Reactive Path Planning Method for Autonomous Mobile Robots in Dynamic Environments

    International Nuclear Information System (INIS)

    Tuvshinjargal, Doopalam; Lee, Deok Jin

    2015-01-01

    In this paper, an efficient dynamic reactive motion planning method for an autonomous vehicle in a dynamic environment is proposed. The purpose of the proposed method is to improve the robustness of autonomous robot motion planning capabilities within dynamic, uncertain environments by integrating a virtual plane-based reactive motion planning technique with a sensor fusion-based obstacle detection approach. The dynamic reactive motion planning method assumes a local observer in the virtual plane, which allows the effective transformation of complex dynamic planning problems into simple stationary ones proving the speed and orientation information between the robot and obstacles. In addition, the sensor fusion-based obstacle detection technique allows the pose estimation of moving obstacles using a Kinect sensor and sonar sensors, thus improving the accuracy and robustness of the reactive motion planning approach. The performance of the proposed method was demonstrated through not only simulation studies but also field experiments using multiple moving obstacles in hostile dynamic environments

  5. Research on pipeline leak detection method based on pressure and dynamic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Likun; Xiong, Min; Zhao, Jinyun; Wang, Hongchao; Xu, Bin; Yu, DongLiang; Sun, Yi; Cai, Yongjun [RnD center of PetroChina Pipeline Company, Langfang, Hebei, (China)

    2010-07-01

    Pipeline leakages are very frequent and need to be detected as fast as possible to avoid safety and environment issues. Many leakage detection processes have been developed. Acoustic wave methods based on static pressure and dynamic pressure are both used for pipeline leakage detection. This study investigated a new pipeline leak detection method based on joint pressure and dynamic pressure. A dynamic pressure transmitter was designed based on a piezoelectric dynamic pressure sensor. The study showed that the dynamic pressure signal should be used for pipeline leak detection with a quick-change in pipeline internal pressure, while the static pressure signal provides better results with a slow-change of pipeline internal pressure. The in-field results showed that the location error of dynamic pressure is reduced to 80 m with a leakage ratio of 0.6 % pipeline throughput.

  6. Particle-based solid for nonsmooth multidomain dynamics

    Science.gov (United States)

    Nordberg, John; Servin, Martin

    2018-04-01

    A method for simulation of elastoplastic solids in multibody systems with nonsmooth and multidomain dynamics is developed. The solid is discretised into pseudo-particles using the meshfree moving least squares method for computing the strain tensor. The particle's strain and stress tensor variables are mapped to a compliant deformation constraint. The discretised solid model thus fit a unified framework for nonsmooth multidomain dynamics simulations including rigid multibodies with complex kinematic constraints such as articulation joints, unilateral contacts with dry friction, drivelines, and hydraulics. The nonsmooth formulation allows for impact impulses to propagate instantly between the rigid multibody and the solid. Plasticity is introduced through an associative perfectly plastic modified Drucker-Prager model. The elastic and plastic dynamics are verified for simple test systems, and the capability of simulating tracked terrain vehicles driving on a deformable terrain is demonstrated.

  7. Chaotic Dynamical State Variables Selection Procedure Based Image Encryption Scheme

    Directory of Open Access Journals (Sweden)

    Zia Bashir

    2017-12-01

    Full Text Available Nowadays, in the modern digital era, the use of computer technologies such as smartphones, tablets and the Internet, as well as the enormous quantity of confidential information being converted into digital form have resulted in raised security issues. This, in turn, has led to rapid developments in cryptography, due to the imminent need for system security. Low-dimensional chaotic systems have low complexity and key space, yet they achieve high encryption speed. An image encryption scheme is proposed that, without compromising the security, uses reasonable resources. We introduced a chaotic dynamic state variables selection procedure (CDSVSP to use all state variables of a hyper-chaotic four-dimensional dynamical system. As a result, less iterations of the dynamical system are required, and resources are saved, thus making the algorithm fast and suitable for practical use. The simulation results of security and other miscellaneous tests demonstrate that the suggested algorithm excels at robustness, security and high speed encryption.

  8. A dynamically-tunable graphene-based fano metasurface

    KAUST Repository

    Amin, Muhammad

    2013-09-01

    A planar graphene metasurface with rectangular holes, which is capable of supporting a dynamically tunable Fano resonance at Terahertz (THz) frequencies, is proposed. The rectangular hole is patterned asymmetrically within the metasurface\\'s unit cell to \\'brighten\\' an originally-dark quadrupolar surface plasmon mode. Fano resonance is achieved via the destructive interference of this mode with a dipolar surface plasmon. The spectral location and line shape of the Fano resonance can be dynamically tuned via a gate voltage applied to the metasurface to change graphene\\'s optical properties. The dynamic tunability of the Fano resonance suggests the applicability of the proposed metasurface in designing THz wave modulators and band-pass filters. © 2013 IEEE.

  9. Dynamic facial expression recognition based on geometric and texture features

    Science.gov (United States)

    Li, Ming; Wang, Zengfu

    2018-04-01

    Recently, dynamic facial expression recognition in videos has attracted growing attention. In this paper, we propose a novel dynamic facial expression recognition method by using geometric and texture features. In our system, the facial landmark movements and texture variations upon pairwise images are used to perform the dynamic facial expression recognition tasks. For one facial expression sequence, pairwise images are created between the first frame and each of its subsequent frames. Integration of both geometric and texture features further enhances the representation of the facial expressions. Finally, Support Vector Machine is used for facial expression recognition. Experiments conducted on the extended Cohn-Kanade database show that our proposed method can achieve a competitive performance with other methods.

  10. ABCD3-I score and the risk of early or 3-month stroke recurrence in tissue- and time-based definitions of TIA and minor stroke.

    Science.gov (United States)

    Mayer, Lukas; Ferrari, Julia; Krebs, Stefan; Boehme, Christian; Toell, Thomas; Matosevic, Benjamin; Tinchon, Alexander; Brainin, Michael; Gattringer, Thomas; Sommer, Peter; Thun, Peter; Willeit, Johann; Lang, Wilfried; Kiechl, Stefan; Knoflach, Michael

    2018-03-01

    Changing definition of TIA from time to a tissue basis questions the validity of the well-established ABCD3-I risk score for recurrent ischemic cerebrovascular events. We analyzed patients with ischemic stroke with mild neurological symptoms arriving TIA or minor stroke, in the prospective multi-center Austrian Stroke Unit Registry. Patients were retrospectively categorized according to a time-based (symptom duration below/above 24 h) and tissue-based (without/with corresponding brain lesion on CT or MRI) definition of TIA or minor stroke. Outcome parameters were early stroke during stroke unit stay and 3-month ischemic stroke. Of the 5237 TIA and minor stroke patients with prospectively documented ABCD3-I score, 2755 (52.6%) had a TIA by the time-based and 2183 (41.7%) by the tissue-based definition. Of the 2457 (46.9%) patients with complete 3-month followup, corresponding numbers were 1195 (48.3%) for the time- and 971 (39.5%) for the tissue-based definition of TIA. Early and 3-month ischemic stroke occurred in 1.1 and 2.5% of time-based TIA, 3.8 and 5.9% of time-based minor stroke, 1.2 and 2.3% of tissue-based TIA as well as in 3.1 and 5.5% of tissue-based minor stroke patients. Irrespective of the definition of TIA and minor stroke, the risk of early and 3-month ischemic stroke steadily increased with increasing ABCD3-I score points. The ABCD3-I score performs equally in TIA patients in tissue- as well as time-based definition and the same is true for minor stroke patients.

  11. Sampling Based Trajectory Planning for Robots in Dynamic Human Environments

    DEFF Research Database (Denmark)

    Svenstrup, Mikael

    2010-01-01

    Open-ended human environments, such as pedestrian streets, hospital corridors, train stations etc., are places where robots start to emerge. Hence, being able to plan safe and natural trajectories in these dynamic environments is an important skill for future generations of robots. In this work...... the problem is formulated as planning a minimal cost trajectory through a potential field, defined from the perceived position and motion of persons in the environment. A modified Rapidlyexploring Random Tree (RRT) algorithm is proposed as a solution to the planning problem. The algorithm implements a new...... for the uncertainty in the dynamic environment. The planning algorithm is demonstrated in a simulated pedestrian street environment....

  12. Coherent Exciton Dynamics in GaAs-Based Semiconductor Structures

    Science.gov (United States)

    Colocci, M.; Bogani, F.; Ceccherini, S.; Gurioli, M.

    We show that a very powerful tool in the investigation of the coherent exciton dynamics in semiconductors is provided by the study of the emitted light after resonant excitation from pairs of phase-locked femtosecond pulses. Under these conditions, not only the full dynamics of the coherent transients (dephasing times, quantum beat periods, etc.) can be obtained from linear experiments, but it can also be obtained a straightforward discrimination between the coherent or incoherent character of the emission by means of spectral filtering.

  13. L-py: an L-system simulation framework for modeling plant architecture development based on a dynamic language.

    Science.gov (United States)

    Boudon, Frédéric; Pradal, Christophe; Cokelaer, Thomas; Prusinkiewicz, Przemyslaw; Godin, Christophe

    2012-01-01

    The study of plant development requires increasingly powerful modeling tools to help understand and simulate the growth and functioning of plants. In the last decade, the formalism of L-systems has emerged as a major paradigm for modeling plant development. Previous implementations of this formalism were made based on static languages, i.e., languages that require explicit definition of variable types before using them. These languages are often efficient but involve quite a lot of syntactic overhead, thus restricting the flexibility of use for modelers. In this work, we present an adaptation of L-systems to the Python language, a popular and powerful open-license dynamic language. We show that the use of dynamic language properties makes it possible to enhance the development of plant growth models: (i) by keeping a simple syntax while allowing for high-level programming constructs, (ii) by making code execution easy and avoiding compilation overhead, (iii) by allowing a high-level of model reusability and the building of complex modular models, and (iv) by providing powerful solutions to integrate MTG data-structures (that are a common way to represent plants at several scales) into L-systems and thus enabling to use a wide spectrum of computer tools based on MTGs developed for plant architecture. We then illustrate the use of L-Py in real applications to build complex models or to teach plant modeling in the classroom.

  14. Three-dimensional sensing methodology combining stereo vision and phase-measuring profilometry based on dynamic programming

    Science.gov (United States)

    Lee, Hyunki; Kim, Min Young; Moon, Jeon Il

    2017-12-01

    Phase measuring profilometry and moiré methodology have been widely applied to the three-dimensional shape measurement of target objects, because of their high measuring speed and accuracy. However, these methods suffer from inherent limitations called a correspondence problem, or 2π-ambiguity problem. Although a kind of sensing method to combine well-known stereo vision and phase measuring profilometry (PMP) technique simultaneously has been developed to overcome this problem, it still requires definite improvement for sensing speed and measurement accuracy. We propose a dynamic programming-based stereo PMP method to acquire more reliable depth information and in a relatively small time period. The proposed method efficiently fuses information from two stereo sensors in terms of phase and intensity simultaneously based on a newly defined cost function of dynamic programming. In addition, the important parameters are analyzed at the view point of the 2π-ambiguity problem and measurement accuracy. To analyze the influence of important hardware and software parameters related to the measurement performance and to verify its efficiency, accuracy, and sensing speed, a series of experimental tests were performed with various objects and sensor configurations.

  15. L-Py: an L-System simulation framework for modeling plant development based on a dynamic language

    Directory of Open Access Journals (Sweden)

    Frederic eBoudon

    2012-05-01

    Full Text Available The study of plant development requires increasingly powerful modeling tools to help understand and simulate the growth and functioning of plants. In the last decade, the formalism of L-systems has emerged as a major paradigm for modeling plant development. Previous implementations of this formalism were made based on static languages, i.e. languages that require explicit definition of variable types before using them. These languages are often efficient but involve quite a lot of syntactic overhead, thus restricting the flexibility of use for modelers. In this work, we present an adaptation of L-systems to the Python language, a popular and powerful open-license dynamic language. We show that the use of dynamic language properties makes it possible to enhance the development of plant growth models: i by keeping a simple syntax while allowing for high-level programming constructs, ii by making code execution easy and avoiding compilation overhead iii allowing a high level of model reusability and the building of complex modular models iv and by providing powerful solutions to integrate MTG data-structures (that are a common way to represent plants at several scales into L-systems and thus enabling to use a wide spectrum of computer tools based on MTGs developed for plant architecture. We then illustrate the use of L-Py in real applications to build complex models or to teach plant modeling in the classroom.

  16. Augmented Virtuality for Coastal Management: A Holistic Use of In Situ and Remote Sensing for Large Scale Definition of Coastal Dynamics

    Directory of Open Access Journals (Sweden)

    Sandro Bartolini

    2018-03-01

    Full Text Available In this paper, the authors describe the architecture of a multidisciplinary data acquisition and visualization platform devoted to the management of coastal environments. The platform integrates heterogeneous data acquisition sub-systems that can be roughly divided into two main categories: remote sensing systems and in situ sensing systems. Remote sensing solutions that are going to be implemented include aerial and underwater data acquisition while in situ sensing solutions include the use of Radio Frequency IDentification (RFID tracers, Wireless Sensor Networks and imaging techniques. All the data collected by these subsystems are stored, integrated and fused on a single platform that is also in charge of data visualization and analysis. This last task is carried out according to the paradigm of Augmented Virtuality that foresees the augmentation of a virtually reconstructed environment with data collected in the real world. The described solution proposes a novel holistic approach where different disciplines concur, with different data acquisition techniques, to a large scale definition of coastal dynamics, in order to better describe and face the coastal erosion phenomenon. The overall framework has been conceived by the so-called Team COSTE, a joint research team between the Universities of Pisa, Siena and Florence.

  17. Adaptive control of structural balance for complex dynamical networks based on dynamic coupling of nodes

    Science.gov (United States)

    Gao, Zilin; Wang, Yinhe; Zhang, Lili

    2018-02-01

    In the existing research results of the complex dynamical networks controlled, the controllers are mainly used to guarantee the synchronization or stabilization of the nodes’ state, and the terms coupled with connection relationships may affect the behaviors of nodes, this obviously ignores the dynamic common behavior of the connection relationships between the nodes. In fact, from the point of view of large-scale system, a complex dynamical network can be regarded to be composed of two time-varying dynamic subsystems, which can be called the nodes subsystem and the connection relationships subsystem, respectively. Similar to the synchronization or stabilization of the nodes subsystem, some characteristic phenomena can be also emerged in the connection relationships subsystem. For example, the structural balance in the social networks and the synaptic facilitation in the biological neural networks. This paper focuses on the structural balance in dynamic complex networks. Generally speaking, the state of the connection relationships subsystem is difficult to be measured accurately in practical applications, and thus it is not easy to implant the controller directly into the connection relationships subsystem. It is noted that the nodes subsystem and the relationships subsystem are mutually coupled, which implies that the state of the connection relationships subsystem can be affected by the controllable state of nodes subsystem. Inspired by this observation, by using the structural balance theory of triad, the controller with the parameter adaptive law is proposed for the nodes subsystem in this paper, which may ensure the connection relationship matrix to approximate a given structural balance matrix in the sense of the uniformly ultimately bounded (UUB). That is, the structural balance may be obtained by employing the controlling state of the nodes subsystem. Finally, the simulations are used to show the validity of the method in this paper.

  18. Dynamic intervention: pathogen disarmament of mitochondrial-based immune surveillance.

    Science.gov (United States)

    Holland, Robin L; Blanke, Steven R

    2014-11-12

    In this issue of Cell Host & Microbe, Suzuki et al. (2014) describe a Vibrio cholerae Type-III-secreted effector that targets mitochondrial dynamics to dampen host innate immune signaling. This suggests that mammalian hosts possess surveillance mechanisms to monitor pathogen-mediated alterations in the integrity of normal cellular processes and organelles. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. An Integrated Dynamic Weighing System Based on SCADA

    Directory of Open Access Journals (Sweden)

    Piotr Bazydło

    2015-01-01

    Full Text Available A prototyped dynamic weighing system has been presented which integrates together three advanced software environments: MATLAB, LabVIEW and iFIX SCADA. They were used for advanced signal processing, data acquisition, as well as visualization and process control. Dynamic weighing is a constantly developing field of metrology. Because of the highly complicated structure of any electronic weighing module, it is vulnerable to many sources of environmental disturbances. For this reason, there is a lot of research concerned with weighing signal processing, mechanical matters and functionality of the system. In the paper, some issues connected with dynamic weighing have been presented, and the necessity of implementing signal processing methods has been discussed. Implementation of this feature is impossible in the majority of SCADA systems. The integration of the three environments mentioned above is an attempt to create an industrial system with capabilities to deal with major dynamic weighing problems. It is innovative because it connects the industrial SCADA, laboratory/industrial product LabVIEW and MATLAB. In addition, the algorithms responsible for process control and data exchange are presented. The paper includes a description of the capabilities, performance tests, as well as benefits and drawbacks, of the system. The outcome of the research is a prototyped system and evaluation of its usefulness. (original abstract

  20. Component Based System Framework for Dynamic B2B Interaction

    NARCIS (Netherlands)

    Hu jinmin, Jinmin; Grefen, P.W.P.J.

    Business-to-Business (B2B) collaboration is becoming a pivotal way to bring today's enterprises to success in the dynamically changing e-business environment. Though many business-to-business protocols are developed to support B2B interaction, none are generally accepted. A B2B system should support

  1. Reliability-based Dynamic Network Design with Stochastic Networks

    NARCIS (Netherlands)

    Li, H.

    2009-01-01

    Transportation systems are stochastic and dynamic systems. The road capacities and the travel demand are fluctuating from time to time within a day and at the same time from day to day. For road users, the travel time and travel costs experienced over time and space are stochastic, thus desire

  2. Measuring Clearance Mechanics Based on Dynamic Leg Length

    Science.gov (United States)

    Khamis, Sam; Danino, Barry; Hayek, Shlomo; Carmeli, Eli

    2018-01-01

    The aim of this study was to quantify clearance mechanics during gait. Seventeen children diagnosed with hemiplegic cerebral palsy underwent a three-dimensional gait analysis evaluation. Dynamic leg lengths were measured from the hip joint center to the heel, to the ankle joint center and to the forefoot throughout the gait cycle. Significant…

  3. based 2D dynamic metal-organic framework showing selective

    Indian Academy of Sciences (India)

    materials have been extensively studied for storage, separation, magnetism, sensing, biomedical and very recently for ion conduction applications.14–21 Hydrogen ... thesis of dynamic MOF with high affinity for water becomes handy in separation applications. Also, for a material to be smart sorbent, in addition to selective ...

  4. High tech supply chain simulation based on dynamical systems model

    NARCIS (Netherlands)

    Yuan, X.; Ashayeri, J.

    2013-01-01

    During the last 45 years, system dynamics as a continuous type of simulation has been used for simulating various problems, ranging from economic to engineering and managerial when limited (historical) information is available. Control theory is another alternative for continuous simulation that

  5. Satellite image based quantification of invasion and patch dynamics ...

    Indian Academy of Sciences (India)

    dynamics of mesquite (Prosopis juliflora) in Great Rann ... The present study was conducted in the Great Rann of Kachchh, part of Kachchh ... The process of Prosopis invasion shows high patch initiation, followed by .... formed by determining the percentage relationship .... poor women in northwestern India benefit from the.

  6. A dynamic data based model describing nephropathia epidemica in Belgium

    NARCIS (Netherlands)

    Amirpour Haredasht, S.; Barrios, J.M.; Maes, P.; Verstraeten, W.W.; Clement, J.; Ducoffre, G.; Lagrou, K.; Van Ranst, M.; Coppin, P.; Berckmans, D.; Aerts, J.M.F.G.

    2011-01-01

    ropathia epidemica (NE) is a human infection caused by Puumala virus (PUUV), which is naturally carried and shed by bank voles (Myodes glareolus). Population dynamics and infectious diseases in general, such as NE, have often been modelled with mechanistic SIR (Susceptible, Infective and Remove with

  7. Efficient graph-based dynamic load-balancing for parallel large-scale agent-based traffic simulation

    NARCIS (Netherlands)

    Xu, Y.; Cai, W.; Aydt, H.; Lees, M.; Tolk, A.; Diallo, S.Y.; Ryzhov, I.O.; Yilmaz, L.; Buckley, S.; Miller, J.A.

    2014-01-01

    One of the issues of parallelizing large-scale agent-based traffic simulations is partitioning and load-balancing. Traffic simulations are dynamic applications where the distribution of workload in the spatial domain constantly changes. Dynamic load-balancing at run-time has shown better efficiency

  8. A Memory Hierarchy Model Based on Data Reuse for Full-Search Motion Estimation on High-Definition Digital Videos

    Directory of Open Access Journals (Sweden)

    Alba Sandyra Bezerra Lopes

    2012-01-01

    Full Text Available The motion estimation is the most complex module in a video encoder requiring a high processing throughput and high memory bandwidth, mainly when the focus is high-definition videos. The throughput problem can be solved increasing the parallelism in the internal operations. The external memory bandwidth may be reduced using a memory hierarchy. This work presents a memory hierarchy model for a full-search motion estimation core. The proposed memory hierarchy model is based on a data reuse scheme considering the full search algorithm features. The proposed memory hierarchy expressively reduces the external memory bandwidth required for the motion estimation process, and it provides a very high data throughput for the ME core. This throughput is necessary to achieve real time when processing high-definition videos. When considering the worst bandwidth scenario, this memory hierarchy is able to reduce the external memory bandwidth in 578 times. A case study for the proposed hierarchy, using 32×32 search window and 8×8 block size, was implemented and prototyped on a Virtex 4 FPGA. The results show that it is possible to reach 38 frames per second when processing full HD frames (1920×1080 pixels using nearly 299 Mbytes per second of external memory bandwidth.

  9. Symptomatic carotid stenosis and stroke risk in patients with transient ischemic attack according to the tissue-based definition.

    Science.gov (United States)

    Al-Khaled, Mohamed; Scheef, Björn

    2016-10-01

    Symptomatic carotid stenosis (sCS), a common cause of transient ischemic attack (TIA), is correlated with higher stroke risk. We investigated the frequency and associated factors of sCS in patients with TIA and the association between sCS and stroke risk following TIA. Over a three-year period (2011-2013), 861 consecutive patients with TIA, who were admitted to the Department of Neurology at the University of Lübeck, Germany, were included in a monocenter study and prospectively evaluated. Diagnosis of TIA was in accordance with the tissue-based definition (transient neurological symptoms without evidence of infarction by brain imaging). Of 827 patients (mean age, 70 ± 13.2 years; 49.7% women), 64 patients (7.7%; 95% confidence interval [CI], 5.9%-9.7%) exhibited sCS and 3 patients (0.3%) showed an occlusion of the corresponding internal carotid artery. Logistic regression revealed that sCS was associated with male sex (odds ratio [OR], 2.7; 95% CI, 1.2-3.6; p = 0.012), amaurosis fugax (OR, 8.1; 95% CI, 3.4-19-4; p definition.

  10. Model-based analysis of postprandial glycemic response dynamics for different types of food

    Directory of Open Access Journals (Sweden)

    Yvonne J. Rozendaal

    2018-06-01

    Full Text Available Summary: Background & aims: Knowledge of postprandial glycemic response (PPGR dynamics is important in nutrition management and diabetes research, care and (selfmanagement. In daily life, food intake is the most important factor influencing the occurrence of hyperglycemia. However, the large variability in PPGR dynamics to different types of food is inadequately predicted by existing glycemic measures. The objective of this study was therefore to quantitatively describe PPGR dynamics using a systems approach. Methods: Postprandial glucose and insulin data were collected from literature for many different food products and mixed meals. The predictive value of existing measures, such as the Glycemic Index, was evaluated. A physiology-based dynamic model was used to reconstruct the full postprandial response profiles of both glucose and insulin simultaneously. Results: We collected a large range of postprandial glucose and insulin dynamics for 53 common food products and mixed meals. Currently available glycemic measures were found to be inadequate to describe the heterogeneity in postprandial dynamics. By estimating model parameters from glucose and insulin data, the physiology-based dynamic model accurately describes the measured data whilst adhering to physiological constraints. Conclusions: The physiology-based dynamic model provides a systematic framework to analyze postprandial glucose and insulin profiles. By changing parameter values the model can be adjusted to simulate impaired glucose tolerance and insulin resistance. Keywords: Postprandial glycemic response, Physiology-based dynamic model, Food intake, Computational modeling, Glucose, Insulin

  11. Gaps Analysis of Integrating Product Design, Manufacturing, and Quality Data in The Supply Chain Using Model-Based Definition.

    Science.gov (United States)

    Trainer, Asa; Hedberg, Thomas; Feeney, Allison Barnard; Fischer, Kevin; Rosche, Phil

    2016-01-01

    Advances in information technology triggered a digital revolution that holds promise of reduced costs, improved productivity, and higher quality. To ride this wave of innovation, manufacturing enterprises are changing how product definitions are communicated - from paper to models. To achieve industry's vision of the Model-Based Enterprise (MBE), the MBE strategy must include model-based data interoperability from design to manufacturing and quality in the supply chain. The Model-Based Definition (MBD) is created by the original equipment manufacturer (OEM) using Computer-Aided Design (CAD) tools. This information is then shared with the supplier so that they can manufacture and inspect the physical parts. Today, suppliers predominantly use Computer-Aided Manufacturing (CAM) and Coordinate Measuring Machine (CMM) models for these tasks. Traditionally, the OEM has provided design data to the supplier in the form of two-dimensional (2D) drawings, but may also include a three-dimensional (3D)-shape-geometry model, often in a standards-based format such as ISO 10303-203:2011 (STEP AP203). The supplier then creates the respective CAM and CMM models and machine programs to produce and inspect the parts. In the MBE vision for model-based data exchange, the CAD model must include product-and-manufacturing information (PMI) in addition to the shape geometry. Today's CAD tools can generate models with embedded PMI. And, with the emergence of STEP AP242, a standards-based model with embedded PMI can now be shared downstream. The on-going research detailed in this paper seeks to investigate three concepts. First, that the ability to utilize a STEP AP242 model with embedded PMI for CAD-to-CAM and CAD-to-CMM data exchange is possible and valuable to the overall goal of a more efficient process. Second, the research identifies gaps in tools, standards, and processes that inhibit industry's ability to cost-effectively achieve model-based-data interoperability in the pursuit of the

  12. Definition of a VR-based protocol to treat social phobia.

    Science.gov (United States)

    Roy, S; Klinger, E; Légeron, P; Lauer, F; Chemin, I; Nugues, P

    2003-08-01

    Social phobia is an anxiety disorder that is accessible to two forms of treatment yielding scientifically validated results: drugs and cognitive-behavioral therapies. Graded exposure to feared social situations is fundamental to obtain an improvement of the anxious symptoms. Traditionally, exposure therapies are done either in vivo or by imagining the situations. In vivo exposure is sometimes difficult to control and many patients have some difficulties in using imagination. Virtual reality (VR) seems to bring significant advantages. It allows exposures to numerous and varied situations. This paper reports the definition of a clinical protocol whose purpose is to assess the efficiency of a VR therapy compared to a CBT and to the absence of treatment for social phobic patients. It explains the illness' diagnosis and its usual treatments. It exposes all the architecture of the study, the assessment tools, the content and unfold of the therapy sessions. It finally reports first results of a clinical trial in a between-group design in 10 patients suffering from social phobia. The virtual environments used in the treatment reproduce four situations that social phobics feel the most threatening: performance, intimacy, scrutiny and assertiveness. With the help of the therapist, the patient learns adapted cognitions and behaviors with the aim of reducing her or his anxiety in the corresponding real situations. The novelty of our work is to address a group of situations that the phobic patient is most likely to experience and to treat patients according to a precise protocol.

  13. Prevalence of metabolic syndrome and its components based on a harmonious definition among adults in Morocco

    Directory of Open Access Journals (Sweden)

    El Brini O

    2014-07-01

    Full Text Available Otmane El Brini,1 Omar Akhouayri,1 Allal Gamal,2 Abdelhalem Mesfioui,1 Bouchra Benazzouz1 1Laboratory of Genetic, Neuroendocrinology and Biotechnology, University Ibn Tofail, Faculty of Sciences, Kenitra, Morocco; 2Diagnostic center, Rabat, Morocco Purpose: Metabolic syndrome is a cluster of risk factors for diabetes and cardiovascular diseases that includes central obesity, hypertension, glucose intolerance, high triglyceride, and low high-density lipoprotein cholesterol. Its prevalence is rapidly increasing worldwide. This study aimed to estimate the prevalence of the metabolic syndrome and associated risk factors in a representative sample of Morocco adults using the 2009 joint interim statement definition. Patients and methods: We analyzed data of 820 patients aged 19 years and older. For metabolic syndrome diagnosis, we used the criteria of the recently published joint interim statement (2009. Results: The prevalence of metabolic syndrome is 35.73% among all adults, 18.56% among men, and 40.12% among women. Prevalence increased with age, peaking among those aged 50–59 years. The most common abnormality highlights abdominal obesity (49.15%. Also, half of patients have one or two risk factors for developing this syndrome. Conclusion: The prevalence of metabolic syndrome and associated risk factors is high among adults in Morocco, especially in women. The most prevalent component of metabolic syndrome in our population was abdominal obesity. Keywords: central obesity, hypertension, glucose intolerance, triglyceride, cholesterol

  14. Objective and quantitative definitions of modified food textures based on sensory and rheological methodology.

    Science.gov (United States)

    Wendin, Karin; Ekman, Susanne; Bülow, Margareta; Ekberg, Olle; Johansson, Daniel; Rothenberg, Elisabet; Stading, Mats

    2010-06-28

    Patients who suffer from chewing and swallowing disorders, i.e. dysphagia, may have difficulties ingesting normal food and liquids. In these patients a texture modified diet may enable that the patient maintain adequate nutrition. However, there is no generally accepted definition of 'texture' that includes measurements describing different food textures. Objectively define and quantify categories of texture-modified food by conducting rheological measurements and sensory analyses. A further objective was to facilitate the communication and recommendations of appropriate food textures for patients with dysphagia. About 15 food samples varying in texture qualities were characterized by descriptive sensory and rheological measurements. Soups were perceived as homogenous; thickened soups were perceived as being easier to swallow, more melting and creamy compared with soups without thickener. Viscosity differed between the two types of soups. Texture descriptors for pâtés were characterized by high chewing resistance, firmness, and having larger particles compared with timbales and jellied products. Jellied products were perceived as wobbly, creamy, and easier to swallow. Concerning the rheological measurements, all solid products were more elastic than viscous (G'>G''), belonging to different G' intervals: jellied products (low G') and timbales together with pâtés (higher G'). By combining sensory and rheological measurements, a system of objective, quantitative, and well-defined food textures was developed that characterizes the different texture categories.

  15. Some implications of an event-based definition of exposure to the risk of road accident.

    Science.gov (United States)

    Elvik, Rune

    2015-03-01

    This paper proposes a new definition of exposure to the risk of road accident as any event, limited in space and time, representing a potential for an accident to occur by bringing road users close to each other in time or space of by requiring a road user to take action to avoid leaving the roadway. A typology of events representing a potential for an accident is proposed. Each event can be interpreted as a trial as defined in probability theory. Risk is the proportion of events that result in an accident. Defining exposure as events demanding the attention of road users implies that road users will learn from repeated exposure to these events, which in turn implies that there will normally be a negative relationship between exposure and risk. Four hypotheses regarding the relationship between exposure and risk are proposed. Preliminary tests support these hypotheses. Advantages and disadvantages of defining exposure as specific events are discussed. It is argued that developments in vehicle technology are likely to make events both observable and countable, thus ensuring that exposure is an operational concept. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Dynamic Data Management Based on Archival Process Integration at the Centre for Environmental Data Archival

    Science.gov (United States)

    Conway, Esther; Waterfall, Alison; Pepler, Sam; Newey, Charles

    2015-04-01

    In this paper we decribe a business process modelling approach to the integration of exisiting archival activities. We provide a high level overview of existing practice and discuss how procedures can be extended and supported through the description of preservation state. The aim of which is to faciliate the dynamic controlled management of scientific data through its lifecycle. The main types of archival processes considered are: • Management processes that govern the operation of an archive. These management processes include archival governance (preservation state management, selection of archival candidates and strategic management) . • Operational processes that constitute the core activities of the archive which maintain the value of research assets. These operational processes are the acquisition, ingestion, deletion, generation of metadata and preservation actvities, • Supporting processes, which include planning, risk analysis and monitoring of the community/preservation environment. We then proceed by describing the feasability testing of extended risk management and planning procedures which integrate current practices. This was done through the CEDA Archival Format Audit which inspected British Atmospherics Data Centre and National Earth Observation Data Centre Archival holdings. These holdings are extensive, comprising of around 2PB of data and 137 million individual files which were analysed and characterised in terms of format based risk. We are then able to present an overview of the risk burden faced by a large scale archive attempting to maintain the usability of heterogeneous environmental data sets. We conclude by presenting a dynamic data management information model that is capable of describing the preservation state of archival holdings throughout the data lifecycle. We provide discussion of the following core model entities and their relationships: • Aspirational entities, which include Data Entity definitions and their associated

  17. Two-Dimensional High Definition Versus Three-Dimensional Endoscopy in Endonasal Skull Base Surgery: A Comparative Preclinical Study.

    Science.gov (United States)

    Rampinelli, Vittorio; Doglietto, Francesco; Mattavelli, Davide; Qiu, Jimmy; Raffetti, Elena; Schreiber, Alberto; Villaret, Andrea Bolzoni; Kucharczyk, Walter; Donato, Francesco; Fontanella, Marco Maria; Nicolai, Piero

    2017-09-01

    Three-dimensional (3D) endoscopy has been recently introduced in endonasal skull base surgery. Only a relatively limited number of studies have compared it to 2-dimensional, high definition technology. The objective was to compare, in a preclinical setting for endonasal endoscopic surgery, the surgical maneuverability of 2-dimensional, high definition and 3D endoscopy. A group of 68 volunteers, novice and experienced surgeons, were asked to perform 2 tasks, namely simulating grasping and dissection surgical maneuvers, in a model of the nasal cavities. Time to complete the tasks was recorded. A questionnaire to investigate subjective feelings during tasks was filled by each participant. In 25 subjects, the surgeons' movements were continuously tracked by a magnetic-based neuronavigator coupled with dedicated software (ApproachViewer, part of GTx-UHN) and the recorded trajectories were analyzed by comparing jitter, sum of square differences, and funnel index. Total execution time was significantly lower with 3D technology (P < 0.05) in beginners and experts. Questionnaires showed that beginners preferred 3D endoscopy more frequently than experts. A minority (14%) of beginners experienced discomfort with 3D endoscopy. Analysis of jitter showed a trend toward increased effectiveness of surgical maneuvers with 3D endoscopy. Sum of square differences and funnel index analyses documented better values with 3D endoscopy in experts. In a preclinical setting for endonasal skull base surgery, 3D technology appears to confer an advantage in terms of time of execution and precision of surgical maneuvers. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Dynamic analysis of the urban-based low-carbon policy using system dynamics: Focused on housing and green space

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Taehoon, E-mail: hong7@yonsei.ac.kr [Associate Professor, Department of Architectural Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Kim, Jimin, E-mail: cookie6249@yonsei.ac.kr; Jeong, Kwangbok, E-mail: kbjeong7@yonsei.ac.kr [Research Assistant and Ph.D. Student, Department of Architectural Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Koo, Choongwan, E-mail: cwkoo@yonsei.ac.kr [Postdoctoral Fellow, Department of Architectural Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of)

    2015-02-09

    To systematically manage the energy consumption of existing buildings, the government has to enforce greenhouse gas reduction policies. However, most of the policies are not properly executed because they do not consider various factors from the urban level perspective. Therefore, this study aimed to conduct a dynamic analysis of an urban-based low-carbon policy using system dynamics, with a specific focus on housing and green space. This study was conducted in the following steps: (i) establishing the variables of urban-based greenhouse gases (GHGs) emissions; (ii) creating a stock/flow diagram of urban-based GHGs emissions; (iii) conducting an information analysis using the system dynamics; and (iv) proposing the urban-based low-carbon policy. If a combined energy policy that uses the housing sector (30%) and the green space sector (30%) at the same time is implemented, 2020 CO{sub 2} emissions will be 7.23 million tons (i.e., 30.48% below 2020 business-as-usual), achieving the national carbon emissions reduction target (26.9%). The results of this study could contribute to managing and improving the fundamentals of the urban-based low-carbon policies to reduce greenhouse gas emissions.

  19. Dynamic analysis of the urban-based low-carbon policy using system dynamics: Focused on housing and green space

    International Nuclear Information System (INIS)

    Hong, Taehoon; Kim, Jimin; Jeong, Kwangbok; Koo, Choongwan

    2015-01-01

    To systematically manage the energy consumption of existing buildings, the government has to enforce greenhouse gas reduction policies. However, most of the policies are not properly executed because they do not consider various factors from the urban level perspective. Therefore, this study aimed to conduct a dynamic analysis of an urban-based low-carbon policy using system dynamics, with a specific focus on housing and green space. This study was conducted in the following steps: (i) establishing the variables of urban-based greenhouse gases (GHGs) emissions; (ii) creating a stock/flow diagram of urban-based GHGs emissions; (iii) conducting an information analysis using the system dynamics; and (iv) proposing the urban-based low-carbon policy. If a combined energy policy that uses the housing sector (30%) and the green space sector (30%) at the same time is implemented, 2020 CO 2 emissions will be 7.23 million tons (i.e., 30.48% below 2020 business-as-usual), achieving the national carbon emissions reduction target (26.9%). The results of this study could contribute to managing and improving the fundamentals of the urban-based low-carbon policies to reduce greenhouse gas emissions

  20. School-Based Mental Health Services: Definitions and Models of Effective Practice

    Science.gov (United States)

    Doll, Beth; Nastasi, Bonnie K.; Cornell, Laura; Song, Samuel Y.

    2017-01-01

    School-based mental health services are those delivered by school-employed and community-employed providers in school buildings. With the implementation of provisions of the Patient Protection and Affordable Care Act (2010) that funds school-based health centers, school-based mental health services could become more broadly available in…

  1. Dynamic and resuspension by waves and sedimentation pattern definition in low energy environments: guaíba lake (Brazil

    Directory of Open Access Journals (Sweden)

    João Luiz Nicolodi

    2013-03-01

    Full Text Available Little research has been undertaken into sediment dynamics in lakes, and most of it only analyses particular aspects such as the texture of the sediments. In this study, the characteristics of the wave field in Guaíba Lake are investigated. The parameters significant wave height (Hs, period (T and direction of wave propagation are examined together with their relation to the resuspension of sediments at the bottom. For this purpose, the mathematical model SWAN (Simulating Waves Nearshore has been validated and employed. The results pointed out that the highest waves modeled reached 0.55 m at a few points in the lake, particularly when winds were blowing from the S and SE quadrants with an intensity over 7 m.s-1. Generally speaking, waves follow wind intensity and direction patterns, and reach maximum height in about 1 to 2 hours after wind speed peaks. Whenever winds were stronger, waves took some 2 hours to reach 0.10 m. However, with weak to moderate winds, the waves took around 3 hours to achieve this value in significant wave height. In addition to speed and direction, wind regularity proved relevant in generating and propagating waves on Lake Guaíba. In conclusion the lake's sediment environments were mapped and classified as follows: 1 Depositional Environments (51% of the lake; 2 Transitional Environments (41%; and 3 Erosional or Non-Depositional Environments (8%. As a contribution to the region's environmental management, elements have been created relating to the concentration of suspended particulate matter.Pesquisas referentes à dinâmica sedimentar em lagos são escassas e a maioria trata da distribuição e textura dos sedimentos, sendo raras aquelas que fazem menção ao padrão de ondas e suas relações com a ressuspensão destes sedimentos e suas consequências. Este trabalho analisa as características das ondas incidentes no Lago Guaíba (Brasil por meio da utilização do SWAN (Simulating Waves Nearshore e suas rela

  2. Monitoring the Como Railway Bridge based on dynamic FBG sensor system

    Science.gov (United States)

    Zhang, Jianzhong; Sun, Weimin; Peng, G. D.; Yuan, Libo

    2007-07-01

    A FBG-based dynamic strain sensor system, whose responding frequency and resolution can be high as 16Hz and ~1μɛ respectively, is described and the system is applied to monitor the dynamic strain of Como Railway Bridge in Australia. The results of one-month long measurement show that the system can figure out all dynamic strain caused by passed trains and also prove the stability of the sensor system.

  3. Dynamic load balancing algorithm for molecular dynamics based on Voronoi cells domain decompositions

    Energy Technology Data Exchange (ETDEWEB)

    Fattebert, J.-L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Richards, D.F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Glosli, J.N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2012-12-01

    We present a new algorithm for automatic parallel load balancing in classical molecular dynamics. It assumes a spatial domain decomposition of particles into Voronoi cells. It is a gradient method which attempts to minimize a cost function by displacing Voronoi sites associated with each processor/sub-domain along steepest descent directions. Excellent load balance has been obtained for quasi-2D and 3D practical applications, with up to 440·106 particles on 65,536 MPI tasks.

  4. Supervision and prognosis architecture based on dynamical classification method for the predictive maintenance of dynamical evolving systems

    International Nuclear Information System (INIS)

    Traore, M.; Chammas, A.; Duviella, E.

    2015-01-01

    In this paper, we are concerned by the improvement of the safety, availability and reliability of dynamical systems’ components subjected to slow degradations (slow drifts). We propose an architecture for efficient Predictive Maintenance (PM) according to the real time estimate of the future state of the components. The architecture is built on supervision and prognosis tools. The prognosis method is based on an appropriated supervision technique that consists in drift tracking of the dynamical systems using AUDyC (AUto-adaptive and Dynamical Clustering), that is an auto-adaptive dynamical classifier. Thus, due to the complexity and the dynamical of the considered systems, the Failure Mode Effect and Criticity Analysis (FMECA) is used to identify the key components of the systems. A component is defined as an element of the system that can be impacted by only one failure. A failure of a key component causes a long downtime of the system. From the FMECA, a Fault Tree Analysis (FTA) of the system are built to determine the propagation laws of a failure on the system by using a deductive method. The proposed architecture is implemented for the PM of a thermoregulator. The application on this real system highlights the interests and the performances of the proposed architecture

  5. Dynamics Analysis for Hydroturbine Regulating System Based on Matrix Model

    Directory of Open Access Journals (Sweden)

    Jiafu Wei

    2017-01-01

    Full Text Available The hydraulic turbine model is the key factor which affects the analysis precision of the hydraulic turbine governing system. This paper discusses the basic principle of the hydraulic turbine matrix model and gives two methods to realize. Using the characteristic matrix to describe unit flow and torque and their relationship with the opening and unit speed, it can accurately represent the nonlinear characteristics of the turbine, effectively improve the convergence of simulation process, and meet the needs of high precision real-time simulation of power system. Through the simulation of a number of power stations, it indicates that, by analyzing the dynamic process of the hydraulic turbine regulating with 5-order matrix model, the calculation results and field test data will have good consistency, and it can better meet the needs of power system dynamic simulation.

  6. Dynamic Socio-technical System Design based on Stakeholder Interaction

    Directory of Open Access Journals (Sweden)

    Albert Fleischmann

    2015-07-01

    Full Text Available In order to directly involve stakeholders in socio-technical system design, we argue for streamlining executable process specifications with business process modeling. Due to current agility requirements of organizations, socio-technical system development is considered one of the key activities of members of the organizations. Dynamic process adaptation enable handling the volatility of business operation and IT infrastructure. Subject-oriented process representations are key enablers to dynamic adaptation due to their capability for stakeholders to create directly executable models. In this way stakeholder can be involved in change management pro-actively. Subject-oriented models (i represent all relevant features required for system control and decision making, and (ii are executable on demand. This effectiveness enables organizational change in a creative and efficient way, while establishing innovative design and change management tools. Subject-oriented Business Process Management capabilities are reflected in this realm revealing benefits and potential for further research.

  7. Dynamic logic architecture based on piecewise-linear systems

    International Nuclear Information System (INIS)

    Peng Haipeng; Liu Fei; Li Lixiang; Yang Yixian; Wang Xue

    2010-01-01

    This Letter explores piecewise-linear systems to construct dynamic logic architecture. The proposed schemes can discriminate the two input signals and obtain 16 kinds of logic operations by different combinations of parameters and conditions for determining the output. Each logic cell performs more flexibly, that makes it possible to achieve complex logic operations more simply and construct computing architecture with less logic cells. We also analyze the various performances of our schemes under different conditions and the characteristics of these schemes.

  8. Kowledge-based dynamic network safety calculations. Wissensbasierte dynamische Netzsicherheitsberechnungen

    Energy Technology Data Exchange (ETDEWEB)

    Kulicke, B [Inst. fuer Hochspannungstechnik und Starkstromanlagen, Berlin (Germany); Schlegel, S [Inst. fuer Hochspannungstechnik und Starkstromanlagen, Berlin (Germany)

    1993-06-28

    An important part of network operation management is the estimation and maintenance of the security of supply. So far the control personnel has only been supported by static network analyses and safety calculations. The authors describe an expert system, which is coupled to a real time simulation program on a transputer basis, for dynamic network safety calculations. They also introduce the system concept and the most important functions of the expert system. (orig.)

  9. Aeroelastic Dynamics Simulation of Two BaffleBased Connected Shells

    Directory of Open Access Journals (Sweden)

    G. A. Shcheglov

    2015-01-01

    Full Text Available The present work is an extention study of aeroelastic vibrations of thin-walled structures with a spatial subsonic flow. An original algorithm for solving complex conjugated aeroelasticity problem, allowing to carry out direct numerical simulation of structural oscillations in the spatial flow of an incompressible medium are developed and tested. On the basis of this simulation study of the spectrum comes the driving forces acting on the flow in a spatial component elastic structure mounted on an impenetrable screen.Currently, updating the mathematical models of unsteady loads that act on the spacepurpose elastic designs such as launch vehicles, service tower installed on the launch pad is a challenge. We consider two thin-walled cantilevered rotating shells connected by a system of elastic couplings, installed next to the impenetrable baffle so that the axes of rotation are perpendicular to the baffle. Dynamics of elastic system is investigated numerically, using the vortex element method with the spatial separated flow of an incompressible medium. A feature of the algorithm is the common commercial complex MSC Patran / Nastran which is used in preparing data to calculate the shell dynamics thereby allowing to consider very complex dynamic schemes.The work performs the first calculations of the model problem concerning the forced oscillations of two coupled cylindrical shells in the flow of an incompressible medium. Comparing the load spectra for the elastic and absolutely rigid structure has shown that the frequency spectra vary slightly. Further calculations are required in which it will be necessary to increase the duration of the calculations, sampling in construction of design scheme, and given the large number of vibration modes that require increasing computing power.Experience in calculating aeroelastic dynamics of complex elastic structures taking into account the screen proved to be successful as a whole, thereby allowing to turn to

  10. Approximate Dynamic Programming Based on High Dimensional Model Representation

    Czech Academy of Sciences Publication Activity Database

    Pištěk, Miroslav

    2013-01-01

    Roč. 49, č. 5 (2013), s. 720-737 ISSN 0023-5954 R&D Projects: GA ČR(CZ) GAP102/11/0437 Institutional support: RVO:67985556 Keywords : approximate dynamic programming * Bellman equation * approximate HDMR minimization * trust region problem Subject RIV: BC - Control Systems Theory Impact factor: 0.563, year: 2013 http://library.utia.cas.cz/separaty/2013/AS/pistek-0399560.pdf

  11. A Dynamic Probabilistic Based Broadcasting Scheme for MANETs

    Science.gov (United States)

    Shanmugam, Kannan; Subburathinam, Karthik; Velayuthampalayam Palanisamy, Arunachalam

    2016-01-01

    MANET is commonly known as Mobile Ad Hoc Network in which cluster of mobile nodes can communicate with each other without having any basic infrastructure. The basic characteristic of MANET is dynamic topology. Due to the dynamic behavior nature, the topology of the network changes very frequently, and this will lead to the failure of the valid route repeatedly. Thus, the process of finding the valid route leads to notable drop in the throughput of the network. To identify a new valid path to the targeted mobile node, available proactive routing protocols use simple broadcasting method known as simple flooding. The simple flooding method broadcasts the RREQ packet from the source to the rest of the nodes in mobile network. But the problem with this method is disproportionate repetitive retransmission of RREQ packet which could result in high contention on the available channel and packet collision due to extreme traffic in the network. A reasonable number of routing algorithms have been suggested for reducing the lethal impact of flooding the RREQ packets. However, most of the algorithms have resulted in considerable amount of complexity and deduce the throughput by depending on special hardware components and maintaining complex information which will be less frequently used. By considering routing complexity with the goal of increasing the throughput of the network, in this paper, we have introduced a new approach called Dynamic Probabilistic Route (DPR) discovery. The Node's Forwarding Probability (NFP) is dynamically calculated by the DPR mobile nodes using Probability Function (PF) which depends on density of local neighbor nodes and the cumulative number of its broadcast covered neighbors. PMID:27019868

  12. Issue Definition in Rights-Based Policy Focused on the Experiences of Individuals with Disabilities: An Examination of Canadian Parliamentary Discourse

    Science.gov (United States)

    Baker, Dana Lee

    2008-01-01

    In issue definition in rights-based policy Canada stereotypically embraces a more positive, human rights-centered approach as compared with the American stereotype associated with the USA's more presumptively negative, civil rights-based tack. Since exclusionary infrastructures violate the core values of democratic governance, a failure to address…

  13. Capturing the Diversity of Successful Aging: An Operational Definition Based on 16-Year Trajectories of Functioning.

    Science.gov (United States)

    Kok, Almar A L; Aartsen, Marja J; Deeg, Dorly J H; Huisman, Martijn

    2017-04-01

    To determine the prevalence and extent of successful aging (SA) when various suggestions proposed in the previous literature for improving models of SA are incorporated into one holistic operational definition. These suggestions include defining and measuring SA as a developmental process, including subjective indicators alongside more objective ones, and expressing SA on a continuum. Data were used from 2,241 respondents in the Longitudinal Aging Study Amsterdam, a multidisciplinary study in a nationally representative sample of older adults in the Netherlands. Latent class growth analysis was used to identify successful 16-year trajectories within nine indicators of physical, cognitive, emotional, and social functioning. SA was quantified as the number of indicators in which individual respondents showed successful trajectories (range 0-9). Successful trajectories were characterized by stability, limited decline, or even improvement of functioning over time. Of the respondents, 39.6% of men and 29.3% of women were successful in at least seven indicators; 7% of men and 11% of women were successful in less than three indicators. Proportions of successful respondents were largest in life satisfaction (>85%) and smallest in social activity (<25%). Correlations of success between separate indicators were low to moderate (range r = .02-.37). Many older adults age relatively successfully, but the character of successful functioning over time varies between indicators, and the combinations of successful indicators vary between individuals. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. Automatic anatomical structures location based on dynamic shape measurement

    Science.gov (United States)

    Witkowski, Marcin; Rapp, Walter; Sitnik, Robert; Kujawinska, Malgorzata; Vander Sloten, Jos; Haex, Bart; Bogaert, Nico; Heitmann, Kjell

    2005-09-01

    New image processing methods and active photonics apparatus have made possible the development of relatively inexpensive optical systems for complex shape and object measurements. We present dynamic 360° scanning method for analysis of human lower body biomechanics, with an emphasis on the analysis of the knee joint. The anatomical structure (of high medical interest) that is possible to scan and analyze, is patella. Tracking of patella position and orientation under dynamic conditions may lead to detect pathological patella movements and help in knee joint disease diagnosis. The processed data is obtained from a dynamic laser triangulation surface measurement system, able to capture slow to normal movements with a scan frequency between 15 and 30 Hz. These frequency rates are enough to capture controlled movements used e.g. for medical examination purposes. The purpose of the work presented is to develop surface analysis methods that may be used as support of diagnosis of motoric abilities of lower limbs. The paper presents algorithms used to process acquired lower limbs surface data in order to find the position and orientation of patella. The algorithms implemented include input data preparation, curvature description methods, knee region discrimination and patella assumed position/orientation calculation. Additionally, a method of 4D (3D + time) medical data visualization is proposed. Also some exemplary results are presented.

  15. Security Analysis of Dynamic SDN Architectures Based on Game Theory

    Directory of Open Access Journals (Sweden)

    Chao Qi

    2018-01-01

    Full Text Available Security evaluation of SDN architectures is of critical importance to develop robust systems and address attacks. Focused on a novel-proposed dynamic SDN framework, a game-theoretic model is presented to analyze its security performance. This model can represent several kinds of players’ information, simulate approximate attack scenarios, and quantitatively estimate systems’ reliability. And we explore several typical game instances defined by system’s capability, players’ objects, and strategies. Experimental results illustrate that the system’s detection capability is not a decisive element to security enhancement as introduction of dynamism and redundancy into SDN can significantly improve security gain and compensate for its detection weakness. Moreover, we observe a range of common strategic actions across environmental conditions. And analysis reveals diverse defense mechanisms adopted in dynamic systems have different effect on security improvement. Besides, the existence of equilibrium in particular situations further proves the novel structure’s feasibility, flexibility, and its persistent ability against long-term attacks.

  16. Dynamic Systems Analysis for Turbine Based Aero Propulsion Systems

    Science.gov (United States)

    Csank, Jeffrey T.

    2016-01-01

    The aircraft engine design process seeks to optimize the overall system-level performance, weight, and cost for a given concept. Steady-state simulations and data are used to identify trade-offs that should be balanced to optimize the system in a process known as systems analysis. These systems analysis simulations and data may not adequately capture the true performance trade-offs that exist during transient operation. Dynamic systems analysis provides the capability for assessing the dynamic tradeoffs at an earlier stage of the engine design process. The dynamic systems analysis concept, developed tools, and potential benefit are presented in this paper. To provide this capability, the Tool for Turbine Engine Closed-loop Transient Analysis (TTECTrA) was developed to provide the user with an estimate of the closed-loop performance (response time) and operability (high pressure compressor surge margin) for a given engine design and set of control design requirements. TTECTrA along with engine deterioration information, can be used to develop a more generic relationship between performance and operability that can impact the engine design constraints and potentially lead to a more efficient engine.

  17. Field-based dynamic light scattering microscopy: theory and numerical analysis.

    Science.gov (United States)

    Joo, Chulmin; de Boer, Johannes F

    2013-11-01

    We present a theoretical framework for field-based dynamic light scattering microscopy based on a spectral-domain optical coherence phase microscopy (SD-OCPM) platform. SD-OCPM is an interferometric microscope capable of quantitative measurement of amplitude and phase of scattered light with high phase stability. Field-based dynamic light scattering (F-DLS) analysis allows for direct evaluation of complex-valued field autocorrelation function and measurement of localized diffusive and directional dynamic properties of biological and material samples with high spatial resolution. In order to gain insight into the information provided by F-DLS microscopy, theoretical and numerical analyses are performed to evaluate the effect of numerical aperture of the imaging optics. We demonstrate that sharp focusing of fields affects the measured diffusive and transport velocity, which leads to smaller values for the dynamic properties in the sample. An approach for accurately determining the dynamic properties of the samples is discussed.

  18. Stability of Mixed-Strategy-Based Iterative Logit Quantal Response Dynamics in Game Theory

    Science.gov (United States)

    Zhuang, Qian; Di, Zengru; Wu, Jinshan

    2014-01-01

    Using the Logit quantal response form as the response function in each step, the original definition of static quantal response equilibrium (QRE) is extended into an iterative evolution process. QREs remain as the fixed points of the dynamic process. However, depending on whether such fixed points are the long-term solutions of the dynamic process, they can be classified into stable (SQREs) and unstable (USQREs) equilibriums. This extension resembles the extension from static Nash equilibriums (NEs) to evolutionary stable solutions in the framework of evolutionary game theory. The relation between SQREs and other solution concepts of games, including NEs and QREs, is discussed. Using experimental data from other published papers, we perform a preliminary comparison between SQREs, NEs, QREs and the observed behavioral outcomes of those experiments. For certain games, we determine that SQREs have better predictive power than QREs and NEs. PMID:25157502

  19. An Energy-Based State Observer for Dynamical Subsystems with Inaccessible State Variables

    NARCIS (Netherlands)

    Khalil, I.S.M.; Sabanovic, Asif; Misra, Sarthak

    2012-01-01

    This work presents an energy-based state estimation formalism for a class of dynamical systems with inaccessible/unknown outputs, and systems at which sensor utilization is impractical, or when measurements can not be taken. The power-conserving physical interconnections among most of the dynamical

  20. Perceptions of the Effectiveness of System Dynamics-Based Interactive Learning Environments: An Empirical Study

    Science.gov (United States)

    Qudrat-Ullah, Hassan

    2010-01-01

    The use of simulations in general and of system dynamics simulation based interactive learning environments (SDILEs) in particular is well recognized as an effective way of improving users' decision making and learning in complex, dynamic tasks. However, the effectiveness of SDILEs in classrooms has rarely been evaluated. This article describes…

  1. An Exploration of the System Dynamics Field : A Model-Based Policy Analysis

    NARCIS (Netherlands)

    Rose, A.C.

    2014-01-01

    This report presents a first look study at the field of System Dynamics. The objective of the study is to perform a model-based policy analysis in order to investigate the future advancement of the System Dynamics field. The aim of this investigation is to determine what this advancement should look

  2. The effect of dynamic workstations on the performance of various computer and office-based tasks

    NARCIS (Netherlands)

    Burford, E.M.; Botter, J.; Commissaris, D.; Könemann, R.; Hiemstra-Van Mastrigt, S.; Ellegast, R.P.

    2013-01-01

    The effect of different workstations, conventional and dynamic, on different types of performance measures for several different office and computer based task was investigated in this research paper. The two dynamic workstations assessed were the Lifespan Treadmill Desk and the RightAngle

  3. Collaborative multi-agent reinforcement learning based on a novel coordination tree frame with dynamic partition

    NARCIS (Netherlands)

    Fang, M.; Groen, F.C.A.; Li, H.; Zhang, J.

    2014-01-01

    In the research of team Markov games, computing the coordinate team dynamically and determining the joint action policy are the main problems. To deal with the first problem, a dynamic team partitioning method is proposed based on a novel coordinate tree frame. We build a coordinate tree with

  4. Dynamic Security Assessment of Danish Power System Based on Decision Trees: Today and Tomorrow

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Liu, Leo; Chen, Zhe

    2013-01-01

    The research work presented in this paper analyzes the impact of wind energy, phasing out of central power plants and cross border power exchange on dynamic security of Danish Power System. Contingency based decision tree (DT) approach is used to assess the dynamic security of present and future...

  5. A unifying energy-based approach to stability of power grids with market dynamics

    NARCIS (Netherlands)

    Stegink, Tjerk; De Persis, Claudio; van der Schaft, Arjan

    2017-01-01

    In this paper a unifying energy-based approach is provided to the modeling and stability analysis of power systems coupled with market dynamics. We consider a standard model of the power network with a third-order model for the synchronous generators involving voltage dynamics. By applying the

  6. A port-Hamiltonian approach to image-based visual servo control for dynamic systems

    NARCIS (Netherlands)

    Mahony, R.; Stramigioli, Stefano

    2012-01-01

    This paper introduces a port-Hamiltonian framework for the design of image-based visual servo control for dynamic mechanical systems. The approach taken introduces the concept of an image effort and provides an interpretation of energy exchange between the dynamics of the physical system and virtual

  7. Students' Geometrical Perception on a Task-Based Dynamic Geometry Platform

    Science.gov (United States)

    Leung, Allen; Lee, Arthur Man Sang

    2013-01-01

    This paper describes a task-based dynamic geometry platform that is able to record student responses in a collective fashion to pre-designed dragging tasks. The platform provides a new type of data and opens up a quantitative dimension to interpret students' geometrical perception in dynamic geometry environments. The platform is capable of…

  8. Dynamics of sustained use and abandonment of clean cooking systems: study protocol for community-based system dynamics modeling.

    Science.gov (United States)

    Kumar, Praveen; Chalise, Nishesh; Yadama, Gautam N

    2016-04-26

    More than 3 billion of the world's population are affected by household air pollution from relying on unprocessed solid fuels for heating and cooking. Household air pollution is harmful to human health, climate, and environment. Sustained uptake and use of cleaner cooking technologies and fuels are proposed as solutions to this problem. In this paper, we present our study protocol aimed at understanding multiple interacting feedback mechanisms involved in the dynamic behavior between social, ecological, and technological systems driving sustained use or abandonment of cleaner cooking technologies among the rural poor in India. This study uses a comparative case study design to understand the dynamics of sustained use or abandonment of cleaner cooking technologies and fuels in four rural communities of Rajasthan, India. The study adopts a community based system dynamics modeling approach. We describe our approach of using community based system dynamics with rural communities to delineate the feedback mechanisms involved in the uptake and sustainment of clean cooking technologies. We develop a reference mode with communities showing the trend over time of use or abandonment of cleaner cooking technologies and fuels in these communities. Subsequently, the study develops a system dynamics model with communities to understand the complex sub-systems driving the behavior in these communities as reflected in the reference mode. We use group model building techniques to facilitate participation of relevant stakeholders in the four communities and elicit a narrative describing the feedback mechanisms underlying sustained adoption or abandonment of cleaner cooking technologies. In understanding the dynamics of feedback mechanisms in the uptake and exclusive use of cleaner cooking systems, we increase the likelihood of dissemination and implementation of efficacious interventions into everyday settings to improve the health and wellbeing of women and children most affected

  9. A web-based, dynamic metadata interface to MDSplus

    International Nuclear Information System (INIS)

    Gardner, Henry J.; Karia, Raju; Manduchi, Gabriele

    2008-01-01

    We introduce the concept of a Fusion Data Grid and discuss the management of metadata within such a Grid. We describe a prototype application which serves fusion data over the internet together with metadata information which can be flexibly created and modified over time. The application interfaces with the MDSplus data acquisition system and it has been designed to capture metadata which is generated by scientists from the post-processing of experimental data. The implementation of dynamic metadata tables using the Java programming language together with an object-relational mapping system, Hibernate, is described in the Appendix

  10. Molecular dynamics computer simulations based on NMR data

    International Nuclear Information System (INIS)

    Vlieg, J. de.

    1989-01-01

    In the work described in this thesis atom-atom distance information obtained from two-dimensional cuclear magnetic resonance is combined with molecular dynamics simulaitons. The simulation is used to improve the accuracy of a structure model constructed on the basis of NMR data. During the MD refinement the crude NMR structure is simultaneously optimized with respect to the atomic interaction function and to the set of atom-atom distances or other NMR information. This means that insufficient experimental data is completed with theoretical knowledge and the combination will lead to more reliable structures than would be obtained from one technique alone. (author). 191 refs.; 17 figs.; 12 schemes; 22 tabs

  11. Multiplexing symbolic dynamics-based chaos communications using synchronization

    International Nuclear Information System (INIS)

    Blakely, Jonathan N; Corron, Ned J

    2005-01-01

    A novel form of multiplexing information-bearing chaotic waveforms is demonstrated experimentally. This scheme dramatically increases the information carrying capacity of a chaotic communication system. In the transmitter, information is encoded in the chaotic waveforms of two electronic circuits using small perturbations to induce the symbolic dynamics to follow a prescribed symbol sequence. Waveforms from each of the drive oscillators are summed to form a single scalar signal that is transmitted to the receiver. Identical oscillators in the receiver synchronize to their counterparts in the drive system, effectively de-multiplexing the transmitted signal. The transmitted information in each channel is extracted from simple return maps of the receiver oscillators

  12. Estimating Outdoor Illumination Conditions Based on Detection of Dynamic Shadows

    DEFF Research Database (Denmark)

    Madsen, Claus B.; Lal, Brajesh Behari

    2013-01-01

    into the image stream to achieve realistic Augmented Reality where the shading and the shadowing of virtual objects is consistent with the real scene. Other techniques require the presence of a known object, a light probe, in the scene for estimating illumination. The technique proposed here works in general......The paper proposes a technique for estimation outdoor illumination conditions in terms of sun and sky radiances directly from pixel values of dynamic shadows detected in video sequences produved by a commercial stereo camera. The technique is applied to the rendering of virtual object...

  13. Game-based dynamic simulations supporting technical education and training

    Directory of Open Access Journals (Sweden)

    Tore Bjølseth

    2006-04-01

    Full Text Available Educational games may improve learning by taking advantage of the new knowledge and skills of today’s students obtained from extensive use of interactive games. This paper describes how interactive dynamic simulators of advanced technical systems and phenomena can be shaped and adapted as games and competitions supporting technical education and training. Some selected examples at different educational levels are shown, from vocational training to university level courses. The potential benefit and perceived learning effect of this approach is also described and underpinned from comprehensive user feedback.

  14. UML Modeling for Dynamic Logistics System Based on DEVS

    OpenAIRE

    Zhang Zhiyong; Liu Jie; Zhang Xinhui

    2013-01-01

    DEVS is a hierarchical and modular system descriptive method. However, it cannot describe dynamic process and relationship of system members. This article has proposed a way to extend UML using stereotype, making it suitable for simulation modeling. To build a modeling tool, we defined atomic model class and coupled model class, both of which are in line with not only DEVS’s hierarchical and modular requirements but also UML’s object-oriented characteristics. At last, we use the tool to analy...

  15. A process-based view of business model dynamics

    DEFF Research Database (Denmark)

    Cavalcante, Sergio Andre

    This thesis is an exploratory study on business model dynamics, i.e. how a firm’s business model changes over time, at both the abstract and performative levels. A central idea of the study is that it is important to abstract the effect of change initiatives on a company in order to better...... understand how these changes might affect the company’s business model in practice. The thesis consists of a collection of five papers written during the period 2008-2011, and represents the conjoint result of both theoretical and empirical research (case studies). The thesis is organized in three parts...

  16. Multiplexing symbolic dynamics-based chaos communications using synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, Jonathan N; Corron, Ned J [US Army RDECOM, AMSRD-AMR-WS-ST, Redstone Arsenal, Huntsville, AL 35898 (United States)

    2005-01-01

    A novel form of multiplexing information-bearing chaotic waveforms is demonstrated experimentally. This scheme dramatically increases the information carrying capacity of a chaotic communication system. In the transmitter, information is encoded in the chaotic waveforms of two electronic circuits using small perturbations to induce the symbolic dynamics to follow a prescribed symbol sequence. Waveforms from each of the drive oscillators are summed to form a single scalar signal that is transmitted to the receiver. Identical oscillators in the receiver synchronize to their counterparts in the drive system, effectively de-multiplexing the transmitted signal. The transmitted information in each channel is extracted from simple return maps of the receiver oscillators.

  17. Dynamic mesh optimization based on the spring analogy

    Directory of Open Access Journals (Sweden)

    Schmidt Jonas

    2014-01-01

    Full Text Available We present an implementation of the spring analogy for three dimensional meshes in OpenFOAM. All parameters of the spring system are treated as fields that can either be pre-defined by the user, or updated at each time step according to specified geometrical regions or diffusion equations. The purpose of the method is to provide a pre-processing tool for mesh optimization. We study three simple test cases, a deformed block, an airfoil and a hill, and we analyze the evolution of skewness, non-orthogonality and aspect ratio during the approach of dynamic equilibrium.

  18. Modeling the angular motion dynamics of spacecraft with a magnetic attitude control system based on experimental studies and dynamic similarity

    Science.gov (United States)

    Kulkov, V. M.; Medvedskii, A. L.; Terentyev, V. V.; Firsyuk, S. O.; Shemyakov, A. O.

    2017-12-01

    The problem of spacecraft attitude control using electromagnetic systems interacting with the Earth's magnetic field is considered. A set of dimensionless parameters has been formed to investigate the spacecraft orientation regimes based on dynamically similar models. The results of experimental studies of small spacecraft with a magnetic attitude control system can be extrapolated to the in-orbit spacecraft motion control regimes by using the methods of the dimensional and similarity theory.

  19. Disturbance dynamics and ecosystem-based forest management

    Science.gov (United States)

    Kalev Jogiste; W. Keith Moser; Malle. Mandre

    2005-01-01

    Ecosystem-based management is intended to balance ecological, social and economic values of sustainable resource management. The desired future state of forest ecosystem is usually defined through productivity, biodiversity, stability or other terms. However, ecosystem-based management may produce an unbalanced emphasis on different components. Although ecosystem-based...

  20. Compressed Sensing for Space-Based High-Definition Video Technologies, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Space-based imaging sensors are important for NASA's mission in both performing scientific measurements and producing literature and documentary cinema. The recent...

  1. Definition of medical event is to be based on the total source strength for evaluation of permanent prostate brachytherapy: A report from the American Society for Radiation Oncology.

    Science.gov (United States)

    Nag, Subir; Demanes, D Jeffrey; Hagan, Michael; Rivard, Mark J; Thomadsen, Bruce R; Welsh, James S; Williamson, Jeffrey F

    2011-10-01

    The Nuclear Regulatory Commission deems it to be a medical event (ME) if the total dose delivered differs from the prescribed dose by 20% or more. A dose-based definition of ME is not appropriate for permanent prostate brachytherapy as it generates too many spurious MEs and thereby creates unnecessary apprehension in patients, and ties up regulatory bodies and the licensees in unnecessary and burdensome investigations. A more suitable definition of ME is required for permanent prostate brachytherapy. The American Society for Radiation Oncology (ASTRO) formed a working group of experienced clinicians to review the literature, assess the validity of current regulations, and make specific recommendations about the definition of an ME in permanent prostate brachytherapy. The working group found that the current definition of ME in §35.3045 as "the total dose delivered differs from the prescribed dose by 20 percent or more" was not suitable for permanent prostate brachytherapy since the prostate volume (and hence the resultant calculated prostate dose) is dependent on the timing of the imaging, the imaging modality used, the observer variability in prostate contouring, the planning margins used, inadequacies of brachytherapy treatment planning systems to calculate tissue doses, and seed migration within and outside the prostate. If a dose-based definition for permanent implants is applied strictly, many properly executed implants would be improperly classified as an ME leading to a detrimental effect on brachytherapy. The working group found that a source strength-based criterion, of >20% of source strength prescribed in the post-procedure written directive being implanted outside the planning target volume is more appropriate for defining ME in permanent prostate brachytherapy. ASTRO recommends that the definition of ME for permanent prostate brachytherapy should not be dose based but should be based upon the source strength (air-kerma strength) administered.

  2. Definition of an automatic information retrieval system independent from the data base used

    International Nuclear Information System (INIS)

    Cunha, E.R.

    1983-04-01

    A bibliographic information retrieval system using data stored at the standardized interchange format ISO 2709 or ANSI Z39.2, is specified. A set of comands for interchange format manipulation wich allows the data access at the logical level, achieving the data independence, are used. A data base description language, a storage structure and data base manipulation comands are specified, using retrieval techniques which consider the applications needs. (Author) [pt

  3. Observer-Based Fault Estimation and Accomodation for Dynamic Systems

    CERN Document Server

    Zhang, Ke; Shi, Peng

    2013-01-01

    Due to the increasing security and reliability demand of actual industrial process control systems, the study on fault diagnosis and fault tolerant control of dynamic systems has received considerable attention. Fault accommodation (FA) is one of effective methods that can be used to enhance system stability and reliability, so it has been widely and in-depth investigated and become a hot topic in recent years. Fault detection is used to monitor whether a fault occurs, which is the first step in FA. On the basis of fault detection, fault estimation (FE) is utilized to determine online the magnitude of the fault, which is a very important step because the additional controller is designed using the fault estimate. Compared with fault detection, the design difficulties of FE would increase a lot, so research on FE and accommodation is very challenging. Although there have been advancements reported on FE and accommodation for dynamic systems, the common methods at the present stage have design difficulties, whi...

  4. Dynamical-Decoupling-Based Quantum Sensing: Floquet Spectroscopy

    Directory of Open Access Journals (Sweden)

    J. E. Lang

    2015-10-01

    Full Text Available Sensing the internal dynamics of individual nuclear spins or clusters of nuclear spins has recently become possible by observing the coherence decay of a nearby electronic spin: the weak magnetic noise is amplified by a periodic, multipulse decoupling sequence. However, it remains challenging to robustly infer underlying atomic-scale structure from decoherence traces in all but the simplest cases. We introduce Floquet spectroscopy as a versatile paradigm for analysis of these experiments and argue that it offers a number of general advantages. In particular, this technique generalizes to more complex situations, offering physical insight in regimes of many-body dynamics, strong coupling, and pulses of finite duration. As there is no requirement for resonant driving, the proposed spectroscopic approach permits physical interpretation of striking, but overlooked, coherence decay features in terms of the form of the avoided crossings of the underlying quasienergy eigenspectrum. This is exemplified by a set of “diamond-shaped” features arising for transverse-field scans in the case of single-spin sensing by nitrogen-vacancy centers in diamond. We also investigate applications for donors in silicon, showing that the resulting tunable interaction strengths offer highly promising future sensors.

  5. Linked-List-Based Multibody Dynamics (MBDyn) Engine

    Science.gov (United States)

    MacLean, John; Brain, Thomas; Wuiocho, Leslie; Huynh, An; Ghosh, Tushar

    2012-01-01

    This new release of MBDyn is a software engine that calculates the dynamics states of kinematic, rigid, or flexible multibody systems. An MBDyn multibody system may consist of multiple groups of articulated chains, trees, or closed-loop topologies. Transient topologies are handled through conservation of energy and momentum. The solution for rigid-body systems is exact, and several configurable levels of nonlinear term fidelity are available for flexible dynamics systems. The algorithms have been optimized for efficiency and can be used for both non-real-time (NRT) and real-time (RT) simulations. Interfaces are currently compatible with NASA's Trick Simulation Environment. This new release represents a significant advance in capability and ease of use. The two most significant new additions are an application programming interface (API) that clarifies and simplifies use of MBDyn, and a link-list infrastructure that allows a single MBDyn instance to propagate an arbitrary number of interacting groups of multibody top ologies. MBDyn calculates state and state derivative vectors for integration using an external integration routine. A Trickcompatible interface is provided for initialization, data logging, integration, and input/output.

  6. Scheduling with Group Dynamics: a Multi-Robot Task Allocation Algorithm based on Vacancy Chains

    National Research Council Canada - National Science Library

    Dahl, Torbjorn S; Mataric, Maja J; Sukhatme, Gaurav S

    2002-01-01

    .... We present a multi-robot task allocation algorithm that is sensitive to group dynamics. Our algorithm is based on vacancy chains, a resource distribution process common in human and animal societies...

  7. Dynamics

    CERN Document Server

    Goodman, Lawrence E

    2001-01-01

    Beginning text presents complete theoretical treatment of mechanical model systems and deals with technological applications. Topics include introduction to calculus of vectors, particle motion, dynamics of particle systems and plane rigid bodies, technical applications in plane motions, theory of mechanical vibrations, and more. Exercises and answers appear in each chapter.

  8. A Method Based on Dial's Algorithm for Multi-time Dynamic Traffic Assignment

    Directory of Open Access Journals (Sweden)

    Rongjie Kuang

    2014-03-01

    Full Text Available Due to static traffic assignment has poor performance in reflecting actual case and dynamic traffic assignment may incurs excessive compute cost, method of multi-time dynamic traffic assignment combining static and dynamic traffic assignment balances factors of precision and cost effectively. A method based on Dial's logit algorithm is proposed in the article to solve the dynamic stochastic user equilibrium problem in dynamic traffic assignment. Before that, a fitting function that can proximately reflect overloaded traffic condition of link is proposed and used to give corresponding model. Numerical example is given to illustrate heuristic procedure of method and to compare results with one of same example solved by other literature's algorithm. Results show that method based on Dial's algorithm is preferable to algorithm from others.

  9. Dynamic modeling method for infrared smoke based on enhanced discrete phase model

    Science.gov (United States)

    Zhang, Zhendong; Yang, Chunling; Zhang, Yan; Zhu, Hongbo

    2018-03-01

    The dynamic modeling of infrared (IR) smoke plays an important role in IR scene simulation systems and its accuracy directly influences the system veracity. However, current IR smoke models cannot provide high veracity, because certain physical characteristics are frequently ignored in fluid simulation; simplifying the discrete phase as a continuous phase and ignoring the IR decoy missile-body spinning. To address this defect, this paper proposes a dynamic modeling method for IR smoke, based on an enhanced discrete phase model (DPM). A mathematical simulation model based on an enhanced DPM is built and a dynamic computing fluid mesh is generated. The dynamic model of IR smoke is then established using an extended equivalent-blackbody-molecule model. Experiments demonstrate that this model realizes a dynamic method for modeling IR smoke with higher veracity.

  10. Guided waves based SHM systems for composites structural elements: statistical analyses finalized at probability of detection definition and assessment

    Science.gov (United States)

    Monaco, E.; Memmolo, V.; Ricci, F.; Boffa, N. D.; Maio, L.

    2015-03-01

    Maintenance approaches based on sensorised structures and Structural Health Monitoring systems could represent one of the most promising innovations in the fields of aerostructures since many years, mostly when composites materials (fibers reinforced resins) are considered. Layered materials still suffer today of drastic reductions of maximum allowable stress values during the design phase as well as of costly and recurrent inspections during the life cycle phase that don't permit of completely exploit their structural and economic potentialities in today aircrafts. Those penalizing measures are necessary mainly to consider the presence of undetected hidden flaws within the layered sequence (delaminations) or in bonded areas (partial disbonding); in order to relax design and maintenance constraints a system based on sensors permanently installed on the structure to detect and locate eventual flaws can be considered (SHM system) once its effectiveness and reliability will be statistically demonstrated via a rigorous Probability Of Detection function definition and evaluation. This paper presents an experimental approach with a statistical procedure for the evaluation of detection threshold of a guided waves based SHM system oriented to delaminations detection on a typical wing composite layered panel. The experimental tests are mostly oriented to characterize the statistical distribution of measurements and damage metrics as well as to characterize the system detection capability using this approach. Numerically it is not possible to substitute part of the experimental tests aimed at POD where the noise in the system response is crucial. Results of experiments are presented in the paper and analyzed.

  11. The relation of metabolic syndrome according to five definitions to cardiovascular risk factors - a population-based study

    Directory of Open Access Journals (Sweden)

    Lai Ming-May

    2009-12-01

    Full Text Available Abstract Background Although National Cholesterol Education Program (NCEP, International Diabetes Federation (IDF, American Heart Association and National Heart, Lung and Blood Institute (AHA/NHLBI, World Health Organization (WHO, and the European Group for the Study of Insulin Resistance (EGIR definitions of metabolic syndrome (MetS have been commonly used by studies, little is known about agreement among these five definitions. We examined the agreement among these five definitions and explored their relationship with risk factors of cardiovascular disease in a Taiwan population. Methods A total of 1305 subjects aged 40 years and over in Taiwan were analyzed. Biomedical markers and anthropometric indices were measured. Agreement among definitions was determined by the kappa statistic. Logistic regression models were fit to estimate the odds of a high cardiovascular risk group for five definitions of MetS. Results The agreement among the NCEP, IDF, and AHA/NHLBI definitions was from substantial to very good, and agreement between the WHO and EGIR definitions was also substantial. All MetS definitions were significantly associated prevalence of microalbuminuria, elevated highly sensitive CRP (hs-CRP, and arterial stiffness only in women. In men, MetS by NCEP and AHA/NHLBI was associated with elevated level of hs-CRP and arterial stiffness. MetS by WHO and EGIR were significantly associated with microalbuminuria. And MetS by WHO was the only MetS definition that significantly associated with prevalence of arterial stiffness (OR: 2.75, 95% CI: 1.22-6.19. Conclusions The associations of these five definitions with cardiovascular risk factors were similar in women, and it was evident that the five definitions performed better in women than in men, with higher ORs observed in relation to arterial stiffness, elevated hs-CRP, and higher Framingham risk scores.

  12. Threshold-based epidemic dynamics in systems with memory

    Science.gov (United States)

    Bodych, Marcin; Ganguly, Niloy; Krueger, Tyll; Mukherjee, Animesh; Siegmund-Schultze, Rainer; Sikdar, Sandipan

    2016-11-01

    In this article we analyze an epidemic dynamics model (SI) where we assume that there are k susceptible states, that is a node would require multiple (k) contacts before it gets infected. In specific, we provide a theoretical framework for studying diffusion rate in complete graphs and d-regular trees with extensions to dense random graphs. We observe that irrespective of the topology, the diffusion process could be divided into two distinct phases: i) the initial phase, where the diffusion process is slow, followed by ii) the residual phase where the diffusion rate increases manifold. In fact, the initial phase acts as an indicator for the total diffusion time in dense graphs. The most remarkable lesson from this investigation is that such a diffusion process could be controlled and even contained if acted upon within its initial phase.

  13. Optimization of decision rules based on dynamic programming approach

    KAUST Repository

    Zielosko, Beata

    2014-01-14

    This chapter is devoted to the study of an extension of dynamic programming approach which allows optimization of approximate decision rules relative to the length and coverage. We introduce an uncertainty measure that is the difference between number of rows in a given decision table and the number of rows labeled with the most common decision for this table divided by the number of rows in the decision table. We fix a threshold γ, such that 0 ≤ γ < 1, and study so-called γ-decision rules (approximate decision rules) that localize rows in subtables which uncertainty is at most γ. Presented algorithm constructs a directed acyclic graph Δ γ T which nodes are subtables of the decision table T given by pairs "attribute = value". The algorithm finishes the partitioning of a subtable when its uncertainty is at most γ. The chapter contains also results of experiments with decision tables from UCI Machine Learning Repository. © 2014 Springer International Publishing Switzerland.

  14. Dynamic tensegrity based cooperative control of uninhabited vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lau, Sook Yen; Naeem, Wasif [Queen' s Univ., Belfast (United Kingdom). School of Electronics, Electrical Engineering and Computer Science

    2013-07-01

    A new formation control methodology is presented in this paper. The proposed technique is modelled by using the concept of cross-tensegrity structures. The main task is to regulate the desired formation of a group of vehicles and to perform point-to-point manoeuvring in the plane. The position of the controlled vehicles in the formation changes with respect to the admissible tendon forces by varying the lengths of bars in the dynamic tensegrity structure modelling. This change of bars' dimensions for geometric transformation is not possible in the application of tensegrity concept in the physical structural engineering. It has been demonstrated that this control method allows more flexibility over a wide range of different shape switching tasks using the predictable tendon control forces under the limited communication's range. The proposed approach is also scalable to any number of pairs of autonomous vehicles in the formation.

  15. Parameter identification for structural dynamics based on interval analysis algorithm

    Science.gov (United States)

    Yang, Chen; Lu, Zixing; Yang, Zhenyu; Liang, Ke

    2018-04-01

    A parameter identification method using interval analysis algorithm for structural dynamics is presented in this paper. The proposed uncertain identification method is investigated by using central difference method and ARMA system. With the help of the fixed memory least square method and matrix inverse lemma, a set-membership identification technology is applied to obtain the best estimation of the identified parameters in a tight and accurate region. To overcome the lack of insufficient statistical description of the uncertain parameters, this paper treats uncertainties as non-probabilistic intervals. As long as we know the bounds of uncertainties, this algorithm can obtain not only the center estimations of parameters, but also the bounds of errors. To improve the efficiency of the proposed method, a time-saving algorithm is presented by recursive formula. At last, to verify the accuracy of the proposed method, two numerical examples are applied and evaluated by three identification criteria respectively.

  16. Rule-based versus probabilistic selection for active surveillance using three definitions of insignificant prostate cancer

    NARCIS (Netherlands)

    L.D.F. Venderbos (Lionne); M.J. Roobol-Bouts (Monique); C.H. Bangma (Chris); R.C.N. van den Bergh (Roderick); L.P. Bokhorst (Leonard); D. Nieboer (Daan); Godtman, R; J. Hugosson (Jonas); van der Kwast, T; E.W. Steyerberg (Ewout)

    2016-01-01

    textabstractTo study whether probabilistic selection by the use of a nomogram could improve patient selection for active surveillance (AS) compared to the various sets of rule-based AS inclusion criteria currently used. We studied Dutch and Swedish patients participating in the European Randomized

  17. Sustainable employability - definition, conceptualization, and implications : A perspective based on the capability approach

    NARCIS (Netherlands)

    van der Klink, J.J.L.; Bültmann, U.; Burdorf, A.; Schaufeli, W.B.; Zijlstra, F.R.H.; Abma, F.I.; Brouwer, S.; van der Wilt, G.J.

    2016-01-01

    Objectives The aim of this paper is to propose a new model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Methods Having evaluated existing conceptual models of work, health, and

  18. Sustainable employability - definition, conceptualization, and implications: A perspective based on the capability approach

    NARCIS (Netherlands)

    Klink, J.J. van der; Bultmann, U.; Burdorf, A.; Schaufeli, W.B.; Zijlstra, F.R.; Abma, F.I.; Brouwer, S.; Wilt, G.J. van der

    2016-01-01

    OBJECTIVES: The aim of this paper is to propose a new model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. METHODS: Having evaluated existing conceptual models of work, health,

  19. Sustainable employability - definition, conceptualization, and implications : A perspective based on the capability approach

    NARCIS (Netherlands)

    van der Klink, Jac J. L.; Bultmann, Ute; Burdorf, Alex; Schaufeli, Wilmar B.; Zijlstra, Fred R. H.; Abma, Femke I.; Brouwer, Sandra; van der Wilt, Gert Jan

    Objectives The aim of this paper is to propose anew model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Methods Having evaluated existing conceptual models of work, health, and

  20. Constructing Image-Based Culture Definitions Using Metaphors: Impact of a Cross-Cultural Immersive Experience

    Science.gov (United States)

    Tuleja, Elizabeth A.

    2017-01-01

    This study provides an approach to teaching and learning in the international business (IB) classroom about cultural values, beliefs, attitudes, and norms through the study of cultural metaphor. The methodology is based on established qualitative methods by using participants' visual pictures and written explanations--representative of their…

  1. Phases of inquiry-based learning: Definitions and the inquiry cycle

    NARCIS (Netherlands)

    Pedaste, Margus; Mäeots, Mario; Siiman, Leo A.; de Jong, Anthonius J.M.; van Riesen, Siswa; Kamp, E.T.; Kamp, E.T.; Manoli, Constantinos C.; Zacharia, Zacharias C.; Tsourlidaki, Eleftheria

    2015-01-01

    Inquiry-based learning is gaining popularity in science curricula, international research and development projects as well as teaching. One of the underlying reasons is that its success can be significantly improved due to the recent technical developments that allow the inquiry process to be

  2. A Gossip-based Churn Estimator for Large Dynamic Networks

    NARCIS (Netherlands)

    Giuffrida, C.; Ortolani, S.

    2010-01-01

    Gossip-based aggregation is an emerging paradigm to perform distributed computations and measurements in a large-scale setting. In this paper we explore the possibility of using gossip-based aggregation to estimate churn in arbitrarily large networks. To this end, we introduce a new model to compute

  3. Rupture Dynamics and Seismic Radiation on Rough Faults for Simulation-Based PSHA

    Science.gov (United States)

    Mai, P. M.; Galis, M.; Thingbaijam, K. K. S.; Vyas, J. C.; Dunham, E. M.

    2017-12-01

    Simulation-based ground-motion predictions may augment PSHA studies in data-poor regions or provide additional shaking estimations, incl. seismic waveforms, for critical facilities. Validation and calibration of such simulation approaches, based on observations and GMPE's, is important for engineering applications, while seismologists push to include the precise physics of the earthquake rupture process and seismic wave propagation in 3D heterogeneous Earth. Geological faults comprise both large-scale segmentation and small-scale roughness that determine the dynamics of the earthquake rupture process and its radiated seismic wavefield. We investigate how different parameterizations of fractal fault roughness affect the rupture evolution and resulting near-fault ground motions. Rupture incoherence induced by fault roughness generates realistic ω-2 decay for high-frequency displacement amplitude spectra. Waveform characteristics and GMPE-based comparisons corroborate that these rough-fault rupture simulations generate realistic synthetic seismogram for subsequent engineering application. Since dynamic rupture simulations are computationally expensive, we develop kinematic approximations that emulate the observed dynamics. Simplifying the rough-fault geometry, we find that perturbations in local moment tensor orientation are important, while perturbations in local source location are not. Thus, a planar fault can be assumed if the local strike, dip, and rake are maintained. The dynamic rake angle variations are anti-correlated with local dip angles. Based on a dynamically consistent Yoffe source-time function, we show that the seismic wavefield of the approximated kinematic rupture well reproduces the seismic radiation of the full dynamic source process. Our findings provide an innovative pseudo-dynamic source characterization that captures fault roughness effects on rupture dynamics. Including the correlations between kinematic source parameters, we present a new

  4. Genetic algorithms with memory- and elitism-based immigrants in dynamic environments.

    Science.gov (United States)

    Yang, Shengxiang

    2008-01-01

    In recent years the genetic algorithm community has shown a growing interest in studying dynamic optimization problems. Several approaches have been devised. The random immigrants and memory schemes are two major ones. The random immigrants scheme addresses dynamic environments by maintaining the population diversity while the memory scheme aims to adapt genetic algorithms quickly to new environments by reusing historical information. This paper investigates a hybrid memory and random immigrants scheme, called memory-based immigrants, and a hybrid elitism and random immigrants scheme, called elitism-based immigrants, for genetic algorithms in dynamic environments. In these schemes, the best individual from memory or the elite from the previous generation is retrieved as the base to create immigrants into the population by mutation. This way, not only can diversity be maintained but it is done more efficiently to adapt genetic algorithms to the current environment. Based on a series of systematically constructed dynamic problems, experiments are carried out to compare genetic algorithms with the memory-based and elitism-based immigrants schemes against genetic algorithms with traditional memory and random immigrants schemes and a hybrid memory and multi-population scheme. The sensitivity analysis regarding some key parameters is also carried out. Experimental results show that the memory-based and elitism-based immigrants schemes efficiently improve the performance of genetic algorithms in dynamic environments.

  5. A dynamic modelling approach for estimating critical loads of nitrogen based on plant community changes under a changing climate

    International Nuclear Information System (INIS)

    Belyazid, Salim; Kurz, Dani; Braun, Sabine; Sverdrup, Harald; Rihm, Beat; Hettelingh, Jean-Paul

    2011-01-01

    A dynamic model of forest ecosystems was used to investigate the effects of climate change, atmospheric deposition and harvest intensity on 48 forest sites in Sweden (n = 16) and Switzerland (n = 32). The model was used to investigate the feasibility of deriving critical loads for nitrogen (N) deposition based on changes in plant community composition. The simulations show that climate and atmospheric deposition have comparably important effects on N mobilization in the soil, as climate triggers the release of organically bound nitrogen stored in the soil during the elevated deposition period. Climate has the most important effect on plant community composition, underlining the fact that this cannot be ignored in future simulations of vegetation dynamics. Harvest intensity has comparatively little effect on the plant community in the long term, while it may be detrimental in the short term following cutting. This study shows: that critical loads of N deposition can be estimated using the plant community as an indicator; that future climatic changes must be taken into account; and that the definition of the reference deposition is critical for the outcome of this estimate. - Research highlights: → Plant community changes can be used to estimate critical loads of nitrogen. → Climate change is decisive for future changes of geochemistry and plant communities. → Climate change cannot be ignored in estimates of critical loads. → The model ForSAFE-Veg was successfully used to set critical loads of nitrogen. - Plant community composition can be used in dynamic modelling to estimate critical loads of nitrogen deposition, provided the appropriate reference deposition, future climate and target plant communities are defined.

  6. DEVS representation of dynamical systems - Event-based intelligent control. [Discrete Event System Specification

    Science.gov (United States)

    Zeigler, Bernard P.

    1989-01-01

    It is shown how systems can be advantageously represented as discrete-event models by using DEVS (discrete-event system specification), a set-theoretic formalism. Such DEVS models provide a basis for the design of event-based logic control. In this control paradigm, the controller expects to receive confirming sensor responses to its control commands within definite time windows determined by its DEVS model of the system under control. The event-based contral paradigm is applied in advanced robotic and intelligent automation, showing how classical process control can be readily interfaced with rule-based symbolic reasoning systems.

  7. What Is Real-World Data (RWD)? : A Review of Definitions Based on Literature and Stakeholder Interviews

    NARCIS (Netherlands)

    Makady, Amr; de Boer, Anthonius; Hillege, Hans; Klungel, Olaf; Goettsch, Wim

    Background: Despite increasing recognition of the value of real-world data (RWD), consensus on the definition of RWD is lacking. Objectives: To review definitions publicly available for RWD to shed light on similarities and differences between them. Methods: A literature review and stakeholder

  8. Online Synchrophasor-Based Dynamic State Estimation using Real-Time Digital Simulator

    DEFF Research Database (Denmark)

    Khazraj, Hesam; Adewole, Adeyemi Charles; Udaya, Annakkage

    2018-01-01

    Dynamic state estimation is a very important control center application used in the dynamic monitoring of state variables. This paper presents and validates a time-synchronized phasor measurement unit (PMU)-based for dynamic state estimation by unscented Kalman filter (UKF) method using the real-...... using the RTDS (real-time digital simulator). The dynamic state variables of multi-machine systems are monitored and measured for the study on the transient behavior of power systems.......Dynamic state estimation is a very important control center application used in the dynamic monitoring of state variables. This paper presents and validates a time-synchronized phasor measurement unit (PMU)-based for dynamic state estimation by unscented Kalman filter (UKF) method using the real......-time digital simulator (RTDS). The dynamic state variables of the system are the rotor angle and speed of the generators. The performance of the UKF method is tested with PMU measurements as inputs using the IEEE 14-bus test system. This test system was modeled in the RSCAD software and tested in real time...

  9. Ultrafast dynamics of solvation and charge transfer in a DNA-based biomaterial.

    Science.gov (United States)

    Choudhury, Susobhan; Batabyal, Subrata; Mondol, Tanumoy; Sao, Dilip; Lemmens, Peter; Pal, Samir Kumar

    2014-05-01

    Charge migration along DNA molecules is a key factor for DNA-based devices in optoelectronics and biotechnology. The association of a significant amount of water molecules in DNA-based materials for the intactness of the DNA structure and their dynamic role in the charge-transfer (CT) dynamics is less documented in contemporary literature. In the present study, we have used a genomic DNA-cetyltrimethyl ammonium chloride (CTMA) complex, a technological important biomaterial, and Hoechest 33258 (H258), a well-known DNA minor groove binder, as fluorogenic probe for the dynamic solvation studies. The CT dynamics of CdSe/ZnS quantum dots (QDs; 5.2 nm) embedded in the as-prepared and swollen biomaterial have also been studied and correlated with that of the timescale of solvation. We have extended our studies on the temperature-dependent CT dynamics of QDs in a nanoenvironment of an anionic, sodium bis(2-ethylhexyl)sulfosuccinate reverse micelle (AOT RMs), whereby the number of water molecules and their dynamics can be tuned in a controlled manner. A direct correlation of the dynamics of solvation and that of the CT in the nanoenvironments clearly suggests that the hydration barrier within the Arrhenius framework essentially dictates the charge-transfer dynamics. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Dengue disease outbreak definitions are implicitly variable

    Directory of Open Access Journals (Sweden)

    Oliver J. Brady

    2015-06-01

    Full Text Available Infectious diseases rarely exhibit simple dynamics. Outbreaks (defined as excess cases beyond response capabilities have the potential to cause a disproportionately high burden due to overwhelming health care systems. The recommendations of international policy guidelines and research agendas are based on a perceived standardised definition of an outbreak characterised by a prolonged, high-caseload, extra-seasonal surge. In this analysis we apply multiple candidate outbreak definitions to reported dengue case data from Brazil to test this assumption. The methods identify highly heterogeneous outbreak characteristics in terms of frequency, duration and case burden. All definitions identify outbreaks with characteristics that vary over time and space. Further, definitions differ in their timeliness of outbreak onset, and thus may be more or less suitable for early intervention. This raises concerns about the application of current outbreak guidelines for early warning/identification systems. It is clear that quantitatively defining the characteristics of an outbreak is an essential prerequisite for effective reactive response. More work is needed so that definitions of disease outbreaks can take into account the baseline capacities of treatment, surveillance and control. This is essential if outbreak guidelines are to be effective and generalisable across a range of epidemiologically different settings.

  11. Risk based definition of TS requirements for NPPs with WWER-1000 type reactor

    International Nuclear Information System (INIS)

    Morozov, V.; Tokmachev, G.

    2000-01-01

    The main regulations in safety related maintenance for NPPs in Russia are defined as a part of Technical Specifications (TSs). It includes limiting conditions for operation (surveillance requirements, allowed outage time, et.). In Russian practice the two levels of TSs are presented: general TSs that have been established as a master documents for similar designed NPPs and plant specific based on operation practice of each NPP unit. This paper presents a brief review of submissions to TS changes for NPPs with WWER type reactor were issued by AEP PSA team since 1988 year. Besides it provides an approach allows to estimate the complex affect on plant risk for both Limiting Conditions of Operation (LCO) and Surveillance Test Intervals (STI) based on relevant probabilistic tool (Minimal Cut Sets method and Marcov Chains methods). (author)

  12. Definitive diagnosis of early enamel and dentin cracks based on microscopic evaluation.

    Science.gov (United States)

    Clark, David J; Sheets, Cherilyn G; Paquette, Jacinthe M

    2003-01-01

    The diagnoses of cracked teeth and incomplete coronal fracture have historically been symptom based. The dental operating microscope at 16x magnification can fundamentally change a clinician's ability to diagnose such conditions. Clinicians have been observing cracks under extreme magnification for nearly a decade. Patterns have become clear that can lead to appropriate treatment prior to symptoms or to devastation to tooth structure. Conversely, many cracks are not structural and can lead to misdiagnosis and overtreatment. Methodic microscopic examination, an understanding of crack progression, and an appreciation of the types of cracks will guide a doctor to make appropriate decisions. Teeth can have structural cracks in various stages. To date, diagnosis and treatment are very often at end stage of crack development. This article gives new guidelines for recognition, visualization, classification, and treatment of cracked teeth based on the routine use of 16x magnification. The significance of enamel cracks as they relate to dentinal cracks is detailed.

  13. A DNA methylation-based definition of biologically distinct breast cancer subtypes.

    Science.gov (United States)

    Stefansson, Olafur A; Moran, Sebastian; Gomez, Antonio; Sayols, Sergi; Arribas-Jorba, Carlos; Sandoval, Juan; Hilmarsdottir, Holmfridur; Olafsdottir, Elinborg; Tryggvadottir, Laufey; Jonasson, Jon G; Eyfjord, Jorunn; Esteller, Manel

    2015-03-01

    In cancer, epigenetic states are deregulated and thought to be of significance in cancer development and progression. We explored DNA methylation-based signatures in association with breast cancer subtypes to assess their impact on clinical presentation and patient prognosis. DNA methylation was analyzed using Infinium 450K arrays in 40 tumors and 17 normal breast samples, together with DNA copy number changes and subtype-specific markers by tissue microarrays. The identified methylation signatures were validated against a cohort of 212 tumors annotated for breast cancer subtypes by the PAM50 method (The Cancer Genome Atlas). Selected markers were pyrosequenced in an independent validation cohort of 310 tumors and analyzed with respect to survival, clinical stage and grade. The results demonstrate that DNA methylation patterns linked to the luminal-B subtype are characterized by CpG island promoter methylation events. In contrast, a large fraction of basal-like tumors are characterized by hypomethylation events occurring within the gene body. Based on these hallmark signatures, we defined two DNA methylation-based subtypes, Epi-LumB and Epi-Basal, and show that they are associated with unfavorable clinical parameters and reduced survival. Our data show that distinct mechanisms leading to changes in CpG methylation states are operative in different breast cancer subtypes. Importantly, we show that a few selected proxy markers can be used to detect the distinct DNA methylation-based subtypes thereby providing valuable information on disease prognosis. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

  14. Configuration management plan. System definition and project development. Repository Based Software Engineering (RBSE) program

    Science.gov (United States)

    Mckay, Charles

    1991-01-01

    This is the configuration management Plan for the AdaNet Repository Based Software Engineering (RBSE) contract. This document establishes the requirements and activities needed to ensure that the products developed for the AdaNet RBSE contract are accurately identified, that proposed changes to the product are systematically evaluated and controlled, that the status of all change activity is known at all times, and that the product achieves its functional performance requirements and is accurately documented.

  15. Shape Distributions of Nonlinear Dynamical Systems for Video-Based Inference.

    Science.gov (United States)

    Venkataraman, Vinay; Turaga, Pavan

    2016-12-01

    This paper presents a shape-theoretic framework for dynamical analysis of nonlinear dynamical systems which appear frequently in several video-based inference tasks. Traditional approaches to dynamical modeling have included linear and nonlinear methods with their respective drawbacks. A novel approach we propose is the use of descriptors of the shape of the dynamical attractor as a feature representation of nature of dynamics. The proposed framework has two main advantages over traditional approaches: a) representation of the dynamical system is derived directly from the observational data, without any inherent assumptions, and b) the proposed features show stability under different time-series lengths where traditional dynamical invariants fail. We illustrate our idea using nonlinear dynamical models such as Lorenz and Rossler systems, where our feature representations (shape distribution) support our hypothesis that the local shape of the reconstructed phase space can be used as a discriminative feature. Our experimental analyses on these models also indicate that the proposed framework show stability for different time-series lengths, which is useful when the available number of samples are small/variable. The specific applications of interest in this paper are: 1) activity recognition using motion capture and RGBD sensors, 2) activity quality assessment for applications in stroke rehabilitation, and 3) dynamical scene classification. We provide experimental validation through action and gesture recognition experiments on motion capture and Kinect datasets. In all these scenarios, we show experimental evidence of the favorable properties of the proposed representation.

  16. Dynamic modeling and performance evaluation of axial flux PMSG based wind turbine system with MPPT control

    Directory of Open Access Journals (Sweden)

    Vahid Behjat

    2014-12-01

    Full Text Available This research work develops dynamic model of a gearless small scale wind power generation system based on a direct driven single sided outer rotor AFPMSG with coreless armature winding. Dynamic modeling of the AFPMSG based wind turbine requires machine parameters. To this end, a 3D FEM model of the generator is developed and from magnetostatic and transient analysis of the FEM model, machine parameters are calculated and utilized in dynamic modeling of the system. A maximum power point tracking (MPPT-based FOC control approach is used to obtain maximum power from the variable wind speed. The simulation results show the proper performance of the developed dynamic model of the AFPMSG, control approach and power generation system.

  17. Event-based scenario manager for multibody dynamics simulation of heavy load lifting operations in shipyards

    Directory of Open Access Journals (Sweden)

    Sol Ha

    2016-01-01

    Full Text Available This paper suggests an event-based scenario manager capable of creating and editing a scenario for shipbuilding process simulation based on multibody dynamics. To configure various situation in shipyards and easily connect with multibody dynamics, the proposed method has two main concepts: an Actor and an Action List. The Actor represents the anatomic unit of action in the multibody dynamics and can be connected to a specific component of the dynamics kernel such as the body and joint. The user can make a scenario up by combining the actors. The Action List contains information for arranging and executing the actors. Since the shipbuilding process is a kind of event-based sequence, all simulation models were configured using Discrete EVent System Specification (DEVS formalism. The proposed method was applied to simulations of various operations in shipyards such as lifting and erection of a block and heavy load lifting operation using multiple cranes.

  18. Tunable and reconfigurable multi-tap microwave photonic filter based on dynamic Brillouin gratings in fibers.

    Science.gov (United States)

    Sancho, J; Primerov, N; Chin, S; Antman, Y; Zadok, A; Sales, S; Thévenaz, L

    2012-03-12

    We propose and experimentally demonstrate new architectures to realize multi-tap microwave photonic filters, based on the generation of a single or multiple dynamic Brillouin gratings in polarization maintaining fibers. The spectral range and selectivity of the proposed periodic filters is extensively tunable, simply by reconfiguring the positions and the number of dynamic gratings along the fiber respectively. In this paper, we present a complete analysis of three different configurations comprising a microwave photonic filter implementation: a simple notch-type Mach-Zehnder approach with a single movable dynamic grating, a multi-tap performance based on multiple dynamic gratings and finally a stationary grating configuration based on the phase modulation of two counter-propagating optical waves by a common pseudo-random bit sequence (PRBS).

  19. Evolution of the DeNOC-based dynamic modelling for multibody systems

    Directory of Open Access Journals (Sweden)

    S. K. Saha

    2013-01-01

    Full Text Available Dynamic modelling of a multibody system plays very essential role in its analyses. As a result, several methods for dynamic modelling have evolved over the years that allow one to analyse multibody systems in a very efficient manner. One such method of dynamic modelling is based on the concept of the Decoupled Natural Orthogonal Complement (DeNOC matrices. The DeNOC-based methodology for dynamics modelling, since its introduction in 1995, has been applied to a variety of multibody systems such as serial, parallel, general closed-loop, flexible, legged, cam-follower, and space robots. The methodology has also proven useful for modelling of proteins and hyper-degree-of-freedom systems like ropes, chains, etc. This paper captures the evolution of the DeNOC-based dynamic modelling applied to different type of systems, and its benefits over other existing methodologies. It is shown that the DeNOC-based modelling provides deeper understanding of the dynamics of a multibody system. The power of the DeNOC-based modelling has been illustrated using several numerical examples.

  20. Displaced, Homeless and Abused: The Dynamics of Gender-Based ...

    African Journals Online (AJOL)

    based abuse (SPGBV) experienced by displaced Zimbabwean refugees, perpetrators of such abuses and the gender of perpetrators in South Africa. Refugee and Internally displaced persons are interchangeably used in this study. Through in-depth ...

  1. Dynamic ligand-based pharmacophore modeling and virtual ...

    Indian Academy of Sciences (India)

    Five ligand-based pharmacophore models were generated from 40 different .... the Phase module of the Schrodinger program.35 Each model consisted of six types of ... ligand preparation included the OPLS_2005 force field and to retain the ...

  2. and Asset-based Poverty Dynamics in Ethiopia

    African Journals Online (AJOL)

    Optiplex 7010 Pro

    poverty status based on consumption and asset ownership. Using panel data ... In recent years Ethiopia has experienced remarkable economic growth with a ...... Understanding the relationship between household demographics and poverty ...

  3. Convergence and Heterogeneity in Euro Based Economies: Stability and Dynamics

    Directory of Open Access Journals (Sweden)

    Philip Haynes

    2016-08-01

    Full Text Available Cluster analysis is used to explore the performance of key macroeconomic variables in European countries that share the euro, from the inception of the currency in 2002 through to 2013. An original applied statistical approach searches for a pattern synthesis across a matrix of macroeconomic data to examine if there is evidence for country clusters and whether there is convergence of the cluster patterns over time. A number of different clusters appear and these change over time as the economies of the member states dynamically interact. This includes some new countries joining the currency during the period of examination. As found in previous research, Southern European countries tend to remain separate from other countries. The new methods used, however, add to an understanding of some differences between Southern European countries, in addition to replicating their broad similarities. Hypotheses are formed about the country clusters existing in 2002, 2006 and 2013, at key points in time of the euro integration process. These hypotheses are tested using the rigour of a bivariate analysis and the multivariate method of Qualitative Comparative Analysis (QCA. The results confirm the hypotheses of cluster memberships in all three periods. The confirmation analysis provides evidence about which variables are most influencing cluster memberships at each time point. In 2002 and 2006, differences between countries are influenced by their different Harmonised Index of Consumer Prices (HICP and labour productivity scores. In 2013, after the crisis, there is a noticeable change. Long term interest rates and gross government debt become key determinants of differences, in addition to the continuing influence of labour productivity. The paper concludes that in the last decade the convergence of countries sharing the euro has been limited, by the joining of new countries and the circumstances of the global economic crisis. The financial crisis has driven

  4. Differential evolution-based multi-objective optimization for the definition of a health indicator for fault diagnostics and prognostics

    Science.gov (United States)

    Baraldi, P.; Bonfanti, G.; Zio, E.

    2018-03-01

    The identification of the current degradation state of an industrial component and the prediction of its future evolution is a fundamental step for the development of condition-based and predictive maintenance approaches. The objective of the present work is to propose a general method for extracting a health indicator to measure the amount of component degradation from a set of signals measured during operation. The proposed method is based on the combined use of feature extraction techniques, such as Empirical Mode Decomposition and Auto-Associative Kernel Regression, and a multi-objective Binary Differential Evolution (BDE) algorithm for selecting the subset of features optimal for the definition of the health indicator. The objectives of the optimization are desired characteristics of the health indicator, such as monotonicity, trendability and prognosability. A case study is considered, concerning the prediction of the remaining useful life of turbofan engines. The obtained results confirm that the method is capable of extracting health indicators suitable for accurate prognostics.

  5. Betwixt and between: Role conflict, role ambiguity and role definition in project-based dual-leadership structures.

    Science.gov (United States)

    Ebbers, Joris J; Wijnberg, Nachoem M

    2017-11-01

    Project-based organizations in the film industry usually have a dual-leadership structure, based on a division of tasks between the dual leaders - the director and the producer - in which the former is predominantly responsible for the artistic and the latter for the commercial aspects of the film. These organizations also have a role hierarchically below and between the dual leaders: the 1st assistant director. This organizational constellation is likely to lead to role conflict and role ambiguity experienced by the person occupying that particular role. Although prior studies found negative effects of role conflict and role ambiguity, this study shows they can also have beneficial effects because they create space for defining the role expansively that, in turn, can be facilitated by the dual leaders defining their own roles more narrowly. In a more general sense, this study also shows the usefulness of analyzing the antecedents and consequences of roles, role definition, and role crafting in connection to the behavior of occupants of adjacent roles.

  6. Betwixt and between: Role conflict, role ambiguity and role definition in project-based dual-leadership structures

    Science.gov (United States)

    Ebbers, Joris J; Wijnberg, Nachoem M

    2017-01-01

    Project-based organizations in the film industry usually have a dual-leadership structure, based on a division of tasks between the dual leaders – the director and the producer – in which the former is predominantly responsible for the artistic and the latter for the commercial aspects of the film. These organizations also have a role hierarchically below and between the dual leaders: the 1st assistant director. This organizational constellation is likely to lead to role conflict and role ambiguity experienced by the person occupying that particular role. Although prior studies found negative effects of role conflict and role ambiguity, this study shows they can also have beneficial effects because they create space for defining the role expansively that, in turn, can be facilitated by the dual leaders defining their own roles more narrowly. In a more general sense, this study also shows the usefulness of analyzing the antecedents and consequences of roles, role definition, and role crafting in connection to the behavior of occupants of adjacent roles. PMID:29081536

  7. Atrial Fibrillation in Patients with Transient Ischemic Attack in Accordance with the Tissue-Based Definition.

    Science.gov (United States)

    Scheef, Björn; Al-Khaled, Mohamed

    2016-06-01

    Transient ischemic attack (TIA) management requires a cardiac evaluation with a Holter electrocardiogram (ECG), preferably a long-term (24 h) electrocardiogram (LT-ECG), to detect atrial fibrillation (AF), which places patients at higher risk of cerebrovascular events. The aim of this study was to determine the frequency of AF using ECG and LT-ECG in patients with tissue-based TIA. During a three-year period (starting in 2011), all consecutive patients with tissue-based TIA (no evidence of infarction by brain imaging) were included and prospectively evaluated. Of 861 patients (mean age, 70 ± 13 years; 49.7% women), 854 patients (99.2%) had an ECG at admission, and 338 patients (39.3%) underwent 24-h LT-ECG monitoring during hospitalization. Patients who underwent LT-ECG monitoring were significantly younger (68 vs. 71 years; P=0.001) and experienced longer symptom duration (143 vs. 79 minutes; P=0.024) compared with those who did not. Furthermore, they had lower rates of unilateral weakness (32% vs. 39%; P=0.034) and previous strokes (18% vs. 26%; P=0.007). The LT-ECG investigation was also associated with longer hospitalization (7.9 vs. 5.7 days; Phypertension (OR, 3.1; 95% CI: 1-8.9; P=0.041) and increased glucose level >6.05 mmol/L) on admission (OR, 1.9; 95% CI: 1-3.5; P=0.036). Cardiac evaluation with LT-ECG appears to increase the rate of detected AF and may lead to a change in secondary prophylaxis in patients with tissue-based TIA.

  8. Active and Dynamic Nanomaterials Based on Active Biomolecules

    Science.gov (United States)

    Koch, Steven J.; Rivera, Susan B.; Boal, Andrew K.; Edwards, J. Matthew; Bauer, Joseph M.; Manginell, Ronald P.; Liu, Jun; Bunker, Bruce C.; Bachand, George D.

    2004-03-01

    Living organisms have evolved dynamic and adaptable materials that fundamentally differ from synthetic materials. These biomaterials use chemical energy to drive non-equilibrium assembly processes, and to reconfigure in response to external stimuli or life cycle changes. Two striking examples are the diatom's active assembly of silica into a patterned cytoskeleton, and the chameleon's active transport of pigment particles to rapidly change skin color. Advances in molecular biology and nanoscale materials synthesis now present the opportunity for integrating biomolecules with synthetic components to produce new types of materials with novel assembly and adaptation capabilities. Our group has begun utilizing kinesin motor proteins and microtubules (MTs) to explore the construction of biomimetic materials. Initial work has focused on characterizing and engineering the properties of the biomolecules for robust performance in artificial systems. We have characterized the biochemical and biophysical properties of a kinesin motor protein from a thermostable fungus, and have evaluated strategies for stabilizing and functionalizing the MTs. We also have developed strategies for directed transport of MT shuttles, and for controlling the loading and unloading of nanoscale cargo.

  9. Conceptualizing a tool to optimize therapy based on dynamic heterogeneity

    International Nuclear Information System (INIS)

    Liao, David; Estévez-Salmerón, Luis; Tlsty, Thea D

    2012-01-01

    Complex biological systems often display a randomness paralleled in processes studied in fundamental physics. This simple stochasticity emerges owing to the complexity of the system and underlies a fundamental aspect of biology called phenotypic stochasticity. Ongoing stochastic fluctuations in phenotype at the single-unit level can contribute to two emergent population phenotypes. Phenotypic stochasticity not only generates heterogeneity within a cell population, but also allows reversible transitions back and forth between multiple states. This phenotypic interconversion tends to restore a population to a previous composition after that population has been depleted of specific members. We call this tendency homeostatic heterogeneity. These concepts of dynamic heterogeneity can be applied to populations composed of molecules, cells, individuals, etc. Here we discuss the concept that phenotypic stochasticity both underlies the generation of heterogeneity within a cell population and can be used to control population composition, contributing, in particular, to both the ongoing emergence of drug resistance and an opportunity for depleting drug-resistant cells. Using notions of both ‘large’ and ‘small’ numbers of biomolecular components, we rationalize our use of Markov processes to model the generation and eradication of drug-resistant cells. Using these insights, we have developed a graphical tool, called a metronomogram, that we propose will allow us to optimize dosing frequencies and total course durations for clinical benefit. (paper)

  10. Epidemic dynamics on a risk-based evolving social network

    Science.gov (United States)

    Antwi, Shadrack; Shaw, Leah

    2013-03-01

    Social network models have been used to study how behavior affects the dynamics of an infection in a population. Motivated by HIV, we consider how a trade-off between benefits and risks of sexual connections determine network structure and disease prevalence. We define a stochastic network model with formation and breaking of links as changes in sexual contacts. Each node has an intrinsic benefit its neighbors derive from connecting to it. Nodes' infection status is not apparent to others, but nodes with more connections (higher degree) are assumed more likely to be infected. The probability to form and break links is determined by a payoff computed from the benefit and degree-dependent risk. The disease is represented by a SI (susceptible-infected) model. We study network and epidemic evolution via Monte Carlo simulation and analytically predict the behavior with a heterogeneous mean field approach. The dependence of network connectivity and infection threshold on parameters is determined, and steady state degree distribution and epidemic levels are obtained. We also study a situation where system-wide infection levels alter perception of risk and cause nodes to adjust their behavior. This is a case of an adaptive network, where node status feeds back to change network geometry.

  11. Functional verification of dynamically reconfigurable FPGA-based systems

    CERN Document Server

    Gong, Lingkan

    2015-01-01

    This book analyzes the challenges in verifying Dynamically Reconfigurable Systems (DRS) with respect to the user design and the physical implementation of such systems. The authors describe the use of a simulation-only layer to emulate the behavior of target FPGAs and accurately model the characteristic features of reconfiguration. Readers are enabled with this simulation-only layer to maintain verification productivity by abstracting away the physical details of the FPGA fabric.  Two implementations of the simulation-only layer are included: Extended ReChannel is a SystemC library that can be used to check DRS designs at a high level; ReSim is a library to support RTL simulation of a DRS reconfiguring both its logic and state. Through a number of case studies, the authors demonstrate how their approach integrates seamlessly with existing, mainstream DRS design flows and with well-established verification methodologies such as top-down modeling and coverage-driven verification. Provides researchers with an i...

  12. Replanning Criteria and Timing Definition for Parotid Protection-Based Adaptive Radiation Therapy in Nasopharyngeal Carcinoma

    Directory of Open Access Journals (Sweden)

    Wei-Rong Yao

    2015-01-01

    Full Text Available The goal of this study was to evaluate real-time volumetric and dosimetric changes of the parotid gland so as to determine replanning criteria and timing for parotid protection-based adaptive radiation therapy in nasopharyngeal carcinoma. Fifty NPC patients were treated with helical tomotherapy; volumetric and dosimetric (Dmean, V1, and D50 changes of the parotid gland at the 1st, 6th, 11th, 16th, 21st, 26th, 31st, and 33rd fractions were evaluated. The clinical parameters affecting these changes were studied by analyses of variance methods for repeated measures. Factors influencing the actual parotid dose were analyzed by a multivariate logistic regression model. The cut-off values predicting parotid overdose were developed from receiver operating characteristic curves and judged by combining them with a diagnostic test consistency check. The median absolute value and percentage of parotid volume reduction were 19.51 cm3 and 35%, respectively. The interweekly parotid volume varied significantly (p<0.05. The parotid Dmean, V1, and D50 increased by 22.13%, 39.42%, and 48.45%, respectively. The actual parotid dose increased by an average of 11.38% at the end of radiation therapy. Initial parotid volume, initial parotid Dmean, and weight loss rate are valuable indicators for parotid protection-based replanning.

  13. Preliminary experience with 4K ultra-high definition endoscope: analysis of pros and cons in skull base surgery.

    Science.gov (United States)

    Rigante, M; La Rocca, G; Lauretti, L; D'Alessandris, G Q; Mangiola, A; Anile, C; Olivi, A; Paludetti, G

    2017-06-01

    During the last two decades endoscopic skull base surgery observed a continuous technical and technological development 3D endoscopy and ultra High Definition (HD) endoscopy have provided great advances in terms of visualisation and spatial resolution. Ultra-high definition (UHD) 4K systems, recently introduced in the clinical practice, will shape next steps forward especially in skull base surgery field. Patients were operated on through transnasal transsphenoidal endoscopic approaches performed using Olympus NBI 4K UHD endoscope with a 4 mm 0° Ultra Telescope, 300 W xenon lamp (CLV-S400) predisposed for narrow band imaging (NBI) technology connected through a camera head to a high-quality control unit (OTV-S400 - VISERA 4K UHD) (Olympus Corporation, Tokyo, Japan). Two screens are used, one 31" Monitor - (LMD-X310S) and one main ultra-HD 55" screen optimised for UHD image reproduction (LMD-X550S). In selected cases, we used a navigation system (Stealthstation S7, Medtronic, Minneapolis, MN, US). We evaluated 22 pituitary adenomas (86.3% macroadenomas; 13.7% microadenomas). 50% were not functional (NF), 22.8% GH, 18.2% ACTH, 9% PRL-secreting. Three of 22 were recurrences. In 91% of cases we achieved total removal, while in 9% near total resection. A mean follow-up of 187 days and average length of hospitalisation was 3.09 ± 0.61 days. Surgical duration was 128.18± 30.74 minutes. We experienced only 1 case of intraoperative low flow fistula with no further complications. None of the cases required any post- or intraoperative blood transfusion. The visualisation and high resolution of the operative field provided a very detailed view of all anatomical structures and pathologies allowing an improvement in safety and efficacy of the surgical procedure. The operative time was similar to the standard 2D HD and 3D procedures and the physical strain was also comparable to others in terms of ergonomics and weight. © Copyright by Società Italiana di Otorinolaringologia

  14. Nonlinear dynamic modeling of a simple flexible rotor system subjected to time-variable base motions

    Science.gov (United States)

    Chen, Liqiang; Wang, Jianjun; Han, Qinkai; Chu, Fulei

    2017-09-01

    Rotor systems carried in transportation system or under seismic excitations are considered to have a moving base. To study the dynamic behavior of flexible rotor systems subjected to time-variable base motions, a general model is developed based on finite element method and Lagrange's equation. Two groups of Euler angles are defined to describe the rotation of the rotor with respect to the base and that of the base with respect to the ground. It is found that the base rotations would cause nonlinearities in the model. To verify the proposed model, a novel test rig which could simulate the base angular-movement is designed. Dynamic experiments on a flexible rotor-bearing system with base angular motions are carried out. Based upon these, numerical simulations are conducted to further study the dynamic response of the flexible rotor under harmonic angular base motions. The effects of base angular amplitude, rotating speed and base frequency on response behaviors are discussed by means of FFT, waterfall, frequency response curve and orbits of the rotor. The FFT and waterfall plots of the disk horizontal and vertical vibrations are marked with multiplications of the base frequency and sum and difference tones of the rotating frequency and the base frequency. Their amplitudes will increase remarkably when they meet the whirling frequencies of the rotor system.

  15. Study on fusion potential barrier in heavy ion reactions based on the dynamical model

    International Nuclear Information System (INIS)

    Tian Junlong; Wu Xizhen; Li Zhuxia; Wang Ning; Liu Fuhu

    2004-01-01

    Based on an improved quantum molecular dynamics model the static and dynamic potential in the entrance channel of synthesis of superheavy nuclei are studied. The dependence of the static potential (and driving potential) on mass-asymmetry is obtained. From this study authors find out that the mass-symmetric system seems to be difficult to fuse and the fusing system with the largest driving potential could be the optimal choice of the projectile-target combination. By comparing the static potential barrier with the dynamic one authors find that the latter one is lower than former one obviously, and that the dynamical potential barrier is entrance energy dependent. The maximum and minimum of dynamic potential barriers approach to the diabatic (sudden approximation) and the adiabatic static potential barriers, respectively

  16. Dynamic Load Balanced Clustering using Elitism based Random Immigrant Genetic Approach for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    K. Mohaideen Pitchai

    2017-07-01

    Full Text Available Wireless Sensor Network (WSN consists of a large number of small sensors with restricted energy. Prolonged network lifespan, scalability, node mobility and load balancing are important needs for several WSN applications. Clustering the sensor nodes is an efficient technique to reach these goals. WSN have the characteristics of topology dynamics because of factors like energy conservation and node movement that leads to Dynamic Load Balanced Clustering Problem (DLBCP. In this paper, Elitism based Random Immigrant Genetic Approach (ERIGA is proposed to solve DLBCP which adapts to topology dynamics. ERIGA uses the dynamic Genetic Algorithm (GA components for solving the DLBCP. The performance of load balanced clustering process is enhanced with the help of this dynamic GA. As a result, the ERIGA achieves to elect suitable cluster heads which balances the network load and increases the lifespan of the network.

  17. Work in process level definition: a method based on computer simulation and electre tri

    Directory of Open Access Journals (Sweden)

    Isaac Pergher

    2014-09-01

    Full Text Available This paper proposes a method for defining the levels of work in progress (WIP in productive environments managed by constant work in process (CONWIP policies. The proposed method combines the approaches of Computer Simulation and Electre TRI to support estimation of the adequate level of WIP and is presented in eighteen steps. The paper also presents an application example, performed on a metalworking company. The research method is based on Computer Simulation, supported by quantitative data analysis. The main contribution of the paper is its provision of a structured way to define inventories according to demand. With this method, the authors hope to contribute to the establishment of better capacity plans in production environments.

  18. Sustainable employability--definition, conceptualization, and implications: A perspective based on the capability approach.

    Science.gov (United States)

    van der Klink, Jac J L; Bültmann, Ute; Burdorf, Alex; Schaufeli, Wilmar B; Zijlstra, Fred R H; Abma, Femke I; Brouwer, Sandra; van der Wilt, Gert Jan

    2016-01-01

    The aim of this paper is to propose a new model of sustainable employability based on the capability approach, encompassing the complexity of contemporary work, and placing particular emphasis on work-related values. Having evaluated existing conceptual models of work, health, and employability, we concluded that prevailing models lack an emphasis on important work-related values. Amartya Sen's capability approach (CA) provides a framework that incorporates a focus on values and reflects the complexity of sustainable employability. We developed a model of sustainable employability based on the CA. This model can be used as starting point for developing an assessment tool to investigate sustainable employability. A fundamental premise of the CA is that work should create value for the organization as well as for the worker. This approach challenges researchers, policy-makers, and practitioners to investigate what people find important and valuable--what they would like to achieve in a given (work) context--and moreover to ascertain whether people are able and enabled to do so. According to this approach, it is not only the individual who is responsible for achieving this; the work context is also important. Rather than merely describing relationships between variables, as existing descriptive models often do, the CA depicts a valuable goal: a set of capabilities that constitute valuable work. Moreover, the CA fits well with recent conceptions of health and modern insights into work, in which the individual works towards his or her own goals that s/he has to achieve within the broader goals of the organization.

  19. LD Definition.

    Science.gov (United States)

    Learning Disability Quarterly, 1987

    1987-01-01

    The position paper (1981) of the National Joint Committee on Learning Disabilities presents a revised definition of learning disabilities and identifies issues and concerns (such as the limitation to children and the exclusion clause) associated with the definition included in P.L. 94-142, the Education for All Handicapped Children Act. (DB)

  20. A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix B: Data base plots for SSME tests 901-290 through 901-414

    Science.gov (United States)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is described. The data base represents dynamic pressure measurements obtained during single engine hot firing tesets of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is also included to estimate spectral trends with SSME power level. Flow dynamic environments in high performance rocket engines are discussed.

  1. A data base and analysis program for shuttle main engine dynamic pressure measurements. Appendix C: Data base plots for SSME tests 902-214 through 902-314

    Science.gov (United States)

    Coffin, T.

    1986-01-01

    A dynamic pressure data base and data base management system developed to characterize the Space Shuttle Main Engine (SSME) dynamic pressure environment is reported. The data base represents dynamic pressure measurements obtained during single engine hot firing tests of the SSME. Software is provided to permit statistical evaluation of selected measurements under specified operating conditions. An interpolation scheme is included to estimate spectral trends with SSME power level. Flow Dynamic Environments in High Performance Rocket Engines are described.

  2. A dynamic Bayesian network based approach to safety decision support in tunnel construction

    International Nuclear Information System (INIS)

    Wu, Xianguo; Liu, Huitao; Zhang, Limao; Skibniewski, Miroslaw J.; Deng, Qianli; Teng, Jiaying

    2015-01-01

    This paper presents a systemic decision approach with step-by-step procedures based on dynamic Bayesian network (DBN), aiming to provide guidelines for dynamic safety analysis of the tunnel-induced road surface damage over time. The proposed DBN-based approach can accurately illustrate the dynamic and updated feature of geological, design and mechanical variables as the construction progress evolves, in order to overcome deficiencies of traditional fault analysis methods. Adopting the predictive, sensitivity and diagnostic analysis techniques in the DBN inference, this approach is able to perform feed-forward, concurrent and back-forward control respectively on a quantitative basis, and provide real-time support before and after an accident. A case study in relating to dynamic safety analysis in the construction of Wuhan Yangtze Metro Tunnel in China is used to verify the feasibility of the proposed approach, as well as its application potential. The relationships between the DBN-based and BN-based approaches are further discussed according to analysis results. The proposed approach can be used as a decision tool to provide support for safety analysis in tunnel construction, and thus increase the likelihood of a successful project in a dynamic project environment. - Highlights: • A dynamic Bayesian network (DBN) based approach for safety decision support is developed. • This approach is able to perform feed-forward, concurrent and back-forward analysis and control. • A case concerning dynamic safety analysis in Wuhan Yangtze Metro Tunnel in China is presented. • DBN-based approach can perform a higher accuracy than traditional static BN-based approach

  3. An Agent-Based Dynamic Model of Politics, Fertility and Economic Development

    Directory of Open Access Journals (Sweden)

    Zining Yang

    2016-08-01

    Full Text Available In the political economy of development, government policy choices at a single point in time can dramatically affect a country's development path by impacting fertility, economic and political decisions across generations. Combining system dynamics and agent-based modeling approaches in a complex adaptive system, a simulation framework of the Politics of Fertility and Economic Development (POFED is formalized to understand the relationship between politics, economic, and demography change at both macro and micro levels. First, a new political capacity measurement is used; and the system dynamics model is validated with the latest data. Second, the endogenous attributes are fused with non-cooperative game theory in an agent-based framework to simulate the interactive political economic dynamics of individual intra-societal transactions. Finally, macro and micro levels are connected with policy levers of political capacity and political instability by merging system dynamics and agent-based components. This paper also explores the agent-based model's behavioral dynamics via simulation methods to identify paths towards economic development and political stability. This model demonstrates micro level human agency can act, react and interact, thus driving macro level dynamics, while macro structures provide political, social and economic environments that constrain or incentivize micro level human behavior.

  4. Statistics Based Models for the Dynamics of Chernivtsi Children Disease

    Directory of Open Access Journals (Sweden)

    Igor G. Nesteruk

    2017-10-01

    Full Text Available Background. Simple mathematical models of contamination and SIR-model of spreading an infection were used to simulate the time dynamics of the unknown before children disease, which occurred in Chernivtsi (Ukraine. The cause of many cases of alopecia, which began in this city in August 1988 is still not fully clarified. According to the official report of the governmental commission, the last new cases occurred in the middle of November 1988, and the reason of the illness was reported as chemical exogenous intoxication. Later this illness became the name “Chernivtsi chemical disease”. Nevertheless, the significantly increased number of new cases of the local alopecia was registered almost three years and is still not clarified. Objective. The comparison of two different versions of the disease: chemical exogenous intoxication and infection. Identification of the parameters of mathematical models and prediction of the disease development. Methods. Analytical solutions of the contamination models and SIR-model for an epidemic are obtained. The optimal values of parameters with the use of linear regression were found. Results. The optimal values of the models parameters with the use of statistical approach were identified. The calculations showed that the infectious version of the disease is more reliable in comparison with the popular contamination one. The possible date of the epidemic beginning was estimated. Conclusions. The optimal parameters of SIR-model allow calculating the realistic number of victims and other characteristics of possible epidemic. They also show that increased number of cases of local alopecia could be a part of the same epidemic as “Chernivtsi chemical disease”.

  5. Dynamic behaviour of ISFET-based Sensor-Actuator systems

    NARCIS (Netherlands)

    Olthuis, Wouter; Luo, J.; Luo, J.; van der Schoot, B.H.; van der Schoot, B.H.; Bomer, Johan G.; Bergveld, Piet

    1990-01-01

    Rapid acid-base titrations can be performed at the surface of a noble-metal electrode with coulometrically generated ions. An ISFET is used as an indicator electrode to detect the equivalence point in the resulting titration curve. The time needed to reach the equivalence point is typically 0.5 to

  6. A need-based approach to dynamic activity generation

    NARCIS (Netherlands)

    Nijland, E.W.L.

    2011-01-01

    Traffic congestion is still an everyday reoccurring problem. Models that predict traffic flows have been developed in the past and, in particular, considerable progress has been made in development and application of activity-based travel demand models over the last decade. However, several issues

  7. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    International Nuclear Information System (INIS)

    Somlai-Schweiger, I.; Ziegler, S. I.

    2015-01-01

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm 3 and 10 × 10 × 10 mm 3 . For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO 4 . Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from 8.2% (1 × 1

  8. Definition of Eight Mulberry Species in the Genus Morus by Internal Transcribed Spacer-Based Phylogeny.

    Directory of Open Access Journals (Sweden)

    Qiwei Zeng

    Full Text Available Mulberry, belonging to the order Rosales, family Moraceae, and genus Morus, has received attention because of both its economic and medicinal value, as well as for its important ecological function. The genus Morus has a worldwide distribution, however, its taxonomy remains complex and disputed. Many studies have attempted to classify Morus species, resulting in varied numbers of designated Morus spp. To address this issue, we used information from internal transcribed spacer (ITS genetic sequences to study the taxonomy of all the members of generally accepted genus Morus. We found that intraspecific 5.8S rRNA sequences were identical but that interspecific 5.8S sequences were diverse. M. alba and M. notabilis showed the shortest (215 bp and the longest (233 bp ITS1 sequence length, respectively. With the completion of the mulberry genome, we could identify single nucleotide polymorphisms within the ITS locus in the M. notabilis genome. From reconstruction of a phylogenetic tree based on the complete ITS data, we propose that the Morus genus should be classified into eight species, including M. alba, M. nigra, M. notabilis, M. serrata, M. celtidifolia, M. insignis, M. rubra, and M. mesozygia. Furthermore, the classification of the ITS sequences of known interspecific hybrid clones into both paternal and maternal clades indicated that ITS variation was sufficient to distinguish interspecific hybrids in the genus Morus.

  9. Definition of Eight Mulberry Species in the Genus Morus by Internal Transcribed Spacer-Based Phylogeny.

    Science.gov (United States)

    Zeng, Qiwei; Chen, Hongyu; Zhang, Chao; Han, Minjing; Li, Tian; Qi, Xiwu; Xiang, Zhonghuai; He, Ningjia

    2015-01-01

    Mulberry, belonging to the order Rosales, family Moraceae, and genus Morus, has received attention because of both its economic and medicinal value, as well as for its important ecological function. The genus Morus has a worldwide distribution, however, its taxonomy remains complex and disputed. Many studies have attempted to classify Morus species, resulting in varied numbers of designated Morus spp. To address this issue, we used information from internal transcribed spacer (ITS) genetic sequences to study the taxonomy of all the members of generally accepted genus Morus. We found that intraspecific 5.8S rRNA sequences were identical but that interspecific 5.8S sequences were diverse. M. alba and M. notabilis showed the shortest (215 bp) and the longest (233 bp) ITS1 sequence length, respectively. With the completion of the mulberry genome, we could identify single nucleotide polymorphisms within the ITS locus in the M. notabilis genome. From reconstruction of a phylogenetic tree based on the complete ITS data, we propose that the Morus genus should be classified into eight species, including M. alba, M. nigra, M. notabilis, M. serrata, M. celtidifolia, M. insignis, M. rubra, and M. mesozygia. Furthermore, the classification of the ITS sequences of known interspecific hybrid clones into both paternal and maternal clades indicated that ITS variation was sufficient to distinguish interspecific hybrids in the genus Morus.

  10. Definition of Motion and Biophysical Indicators for Home-Based Rehabilitation through Serious Games

    Directory of Open Access Journals (Sweden)

    Matteo Morando

    2018-05-01

    Full Text Available In this paper, we describe Remote Monitoring Validation Engineering System (ReMoVES, a newly-developed platform for motion rehabilitation through serious games and biophysical sensors. The main features of the system are highlighted as follows: motion tracking capabilities through Microsoft Kinect V2 and Leap Motion are disclosed and compared with other solutions; the emotional state of the patient is evaluated with heart rate measurements and electrodermal activity monitored by Microsoft Band 2 during the execution of the functional exercises planned by the therapist. The ReMoVES platform is conceived for home-based rehabilitation after the hospitalisation period, and the system will deploy machine learning techniques to provide an automated evaluation of the patient performance during the training. The algorithms should deliver effective reports to the therapist about the training performance while the patient exercises on their own. The game features that will be described in this manuscript represent the input for the training set, while the feedback provided by the therapist is the output. To face this supervised learning problem, we are describing the most significant features to be used as key indicators of the patient’s performance along with the evaluation of their accuracy in discriminating between good or bad patient actions.

  11. Application of machine learning methodology for pet-based definition of lung cancer

    Science.gov (United States)

    Kerhet, A.; Small, C.; Quon, H.; Riauka, T.; Schrader, L.; Greiner, R.; Yee, D.; McEwan, A.; Roa, W.

    2010-01-01

    We applied a learning methodology framework to assist in the threshold-based segmentation of non-small-cell lung cancer (nsclc) tumours in positron-emission tomography–computed tomography (pet–ct) imaging for use in radiotherapy planning. Gated and standard free-breathing studies of two patients were independently analysed (four studies in total). Each study had a pet–ct and a treatment-planning ct image. The reference gross tumour volume (gtv) was identified by two experienced radiation oncologists who also determined reference standardized uptake value (suv) thresholds that most closely approximated the gtv contour on each slice. A set of uptake distribution-related attributes was calculated for each pet slice. A machine learning algorithm was trained on a subset of the pet slices to cope with slice-to-slice variation in the optimal suv threshold: that is, to predict the most appropriate suv threshold from the calculated attributes for each slice. The algorithm’s performance was evaluated using the remainder of the pet slices. A high degree of geometric similarity was achieved between the areas outlined by the predicted and the reference suv thresholds (Jaccard index exceeding 0.82). No significant difference was found between the gated and the free-breathing results in the same patient. In this preliminary work, we demonstrated the potential applicability of a machine learning methodology as an auxiliary tool for radiation treatment planning in nsclc. PMID:20179802

  12. Definition of Eight Mulberry Species in the Genus Morus by Internal Transcribed Spacer-Based Phylogeny

    Science.gov (United States)

    Zeng, Qiwei; Chen, Hongyu; Zhang, Chao; Han, Minjing; Li, Tian; Qi, Xiwu; Xiang, Zhonghuai; He, Ningjia

    2015-01-01

    Mulberry, belonging to the order Rosales, family Moraceae, and genus Morus, has received attention because of both its economic and medicinal value, as well as for its important ecological function. The genus Morus has a worldwide distribution, however, its taxonomy remains complex and disputed. Many studies have attempted to classify Morus species, resulting in varied numbers of designated Morus spp. To address this issue, we used information from internal transcribed spacer (ITS) genetic sequences to study the taxonomy of all the members of generally accepted genus Morus. We found that intraspecific 5.8S rRNA sequences were identical but that interspecific 5.8S sequences were diverse. M. alba and M. notabilis showed the shortest (215 bp) and the longest (233 bp) ITS1 sequence length, respectively. With the completion of the mulberry genome, we could identify single nucleotide polymorphisms within the ITS locus in the M. notabilis genome. From reconstruction of a phylogenetic tree based on the complete ITS data, we propose that the Morus genus should be classified into eight species, including M. alba, M. nigra, M. notabilis, M. serrata, M. celtidifolia, M. insignis, M. rubra, and M. mesozygia. Furthermore, the classification of the ITS sequences of known interspecific hybrid clones into both paternal and maternal clades indicated that ITS variation was sufficient to distinguish interspecific hybrids in the genus Morus. PMID:26266951

  13. Decision Support System Requirements Definition for Human Extravehicular Activity Based on Cognitive Work Analysis.

    Science.gov (United States)

    Miller, Matthew James; McGuire, Kerry M; Feigh, Karen M

    2017-06-01

    The design and adoption of decision support systems within complex work domains is a challenge for cognitive systems engineering (CSE) practitioners, particularly at the onset of project development. This article presents an example of applying CSE techniques to derive design requirements compatible with traditional systems engineering to guide decision support system development. Specifically, it demonstrates the requirements derivation process based on cognitive work analysis for a subset of human spaceflight operations known as extravehicular activity . The results are presented in two phases. First, a work domain analysis revealed a comprehensive set of work functions and constraints that exist in the extravehicular activity work domain. Second, a control task analysis was performed on a subset of the work functions identified by the work domain analysis to articulate the translation of subject matter states of knowledge to high-level decision support system requirements. This work emphasizes an incremental requirements specification process as a critical component of CSE analyses to better situate CSE perspectives within the early phases of traditional systems engineering design.

  14. LCP method for a planar passive dynamic walker based on an event-driven scheme

    Science.gov (United States)

    Zheng, Xu-Dong; Wang, Qi

    2018-06-01

    The main purpose of this paper is to present a linear complementarity problem (LCP) method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange's equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb's law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCP, which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated: the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.

  15. Sliding mode-based lateral vehicle dynamics control using tyre force measurements

    Science.gov (United States)

    Kunnappillil Madhusudhanan, Anil; Corno, Matteo; Holweg, Edward

    2015-11-01

    In this work, a lateral vehicle dynamics control based on tyre force measurements is proposed. Most of the lateral vehicle dynamics control schemes are based on yaw rate whereas tyre forces are the most important variables in vehicle dynamics as tyres are the only contact points between the vehicle and road. In the proposed method, active front steering is employed to uniformly distribute the required lateral force among the front left and right tyres. The force distribution is quantified through the tyre utilisation coefficients. In order to address the nonlinearities and uncertainties of the vehicle model, a gain scheduling sliding-mode control technique is used. In addition to stabilising the lateral dynamics, the proposed controller is able to maintain maximum lateral acceleration. The proposed method is tested and validated on a multi-body vehicle simulator.

  16. Multiobjective Traffic Signal Control Model for Intersection Based on Dynamic Turning Movements Estimation

    Directory of Open Access Journals (Sweden)

    Pengpeng Jiao

    2014-01-01

    Full Text Available The real-time traffic signal control for intersection requires dynamic turning movements as the basic input data. It is impossible to detect dynamic turning movements directly through current traffic surveillance systems, but dynamic origin-destination (O-D estimation can obtain it. However, the combined models of dynamic O-D estimation and real-time traffic signal control are rare in the literature. A framework for the multiobjective traffic signal control model for intersection based on dynamic O-D estimation (MSC-DODE is presented. A state-space model using Kalman filtering is first formulated to estimate the dynamic turning movements; then a revised sequential Kalman filtering algorithm is designed to solve the model, and the root mean square error and mean percentage error are used to evaluate the accuracy of estimated dynamic turning proportions. Furthermore, a multiobjective traffic signal control model is put forward to achieve real-time signal control parameters and evaluation indices. Finally, based on practical survey data, the evaluation indices from MSC-DODE are compared with those from Webster method. The actual and estimated turning movements are further input into MSC-DODE, respectively, and results are also compared. Case studies show that results of MSC-DODE are better than those of Webster method and are very close to unavailable actual values.

  17. Transient Dynamic Mechanical Analysis of Resilin-based Elastomeric Hydrogels

    Science.gov (United States)

    Li, Linqing; Kiick, Kristi

    2014-04-01

    The outstanding high-frequency properties of emerging resilin-like polypeptides (RLPs) have motivated their development for vocal fold tissue regeneration and other applications. Recombinant RLP hydrogels show efficient gelation, tunable mechanical properties, and display excellent extensibility, but little has been reported about their transient mechanical properties. In this manuscript, we describe the transient mechanical behavior of new RLP hydrogels investigated via both sinusoidal oscillatory shear deformation and uniaxial tensile testing. Oscillatory stress relaxation and creep experiments confirm that RLP-based hydrogels display significantly reduced stress relaxation and improved strain recovery compared to PEG-based control hydrogels. Uniaxial tensile testing confirms the negligible hysteresis, reversible elasticity and superior resilience (up to 98%) of hydrated RLP hydrogels, with Young’s modulus values that compare favorably with those previously reported for resilin and that mimic the tensile properties of the vocal fold ligament at low strain (engineering applications, of a range of RLP hydrogels.

  18. Robust PRNG based on homogeneously distributed chaotic dynamics

    International Nuclear Information System (INIS)

    Garasym, Oleg; Taralova, Ina; Lozi, René

    2016-01-01

    This paper is devoted to the design of new chaotic Pseudo Random Number Generator (CPRNG). Exploring several topologies of network of 1-D coupled chaotic mapping, we focus first on two dimensional networks. Two topologically coupled maps are studied: TTL rc non-alternate, and TTL SC alternate. The primary idea of the novel maps has been based on an original coupling of the tent and logistic maps to achieve excellent random properties and homogeneous /uniform/ density in the phase plane, thus guaranteeing maximum security when used for chaos base cryptography. In this aim two new nonlinear CPRNG: MTTL 2 sc and NTTL 2 are proposed. The maps successfully passed numerous statistical, graphical and numerical tests, due to proposed ring coupling and injection mechanisms. (paper)

  19. Model-based estimation for dynamic cardiac studies using ECT

    International Nuclear Information System (INIS)

    Chiao, P.C.; Rogers, W.L.; Clinthorne, N.H.; Fessler, J.A.; Hero, A.O.

    1994-01-01

    In this paper, the authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (Emission Computed Tomography). The authors construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. The authors also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, model assumptions and potential uses of the joint estimation strategy are discussed

  20. Model-based estimation for dynamic cardiac studies using ECT.

    Science.gov (United States)

    Chiao, P C; Rogers, W L; Clinthorne, N H; Fessler, J A; Hero, A O

    1994-01-01

    The authors develop a strategy for joint estimation of physiological parameters and myocardial boundaries using ECT (emission computed tomography). They construct an observation model to relate parameters of interest to the projection data and to account for limited ECT system resolution and measurement noise. The authors then use a maximum likelihood (ML) estimator to jointly estimate all the parameters directly from the projection data without reconstruction of intermediate images. They also simulate myocardial perfusion studies based on a simplified heart model to evaluate the performance of the model-based joint ML estimator and compare this performance to the Cramer-Rao lower bound. Finally, the authors discuss model assumptions and potential uses of the joint estimation strategy.

  1. Fuzzy Modelling for Human Dynamics Based on Online Social Networks.

    Science.gov (United States)

    Cuenca-Jara, Jesus; Terroso-Saenz, Fernando; Valdes-Vela, Mercedes; Skarmeta, Antonio F

    2017-08-24

    Human mobility mining has attracted a lot of attention in the research community due to its multiple implications in the provisioning of innovative services for large metropolises. In this scope, Online Social Networks (OSN) have arisen as a promising source of location data to come up with new mobility models. However, the human nature of this data makes it rather noisy and inaccurate. In order to deal with such limitations, the present work introduces a framework for human mobility mining based on fuzzy logic. Firstly, a fuzzy clustering algorithm extracts the most active OSN areas at different time periods. Next, such clusters are the building blocks to compose mobility patterns. Furthermore, a location prediction service based on a fuzzy rule classifier has been developed on top of the framework. Finally, both the framework and the predictor has been tested with a Twitter and Flickr dataset in two large cities.

  2. Theoretical foundation for jung's “Mandala Symbolism” based on discrete chaotic dynamics of interacting neurons

    Directory of Open Access Journals (Sweden)

    V. Gontar

    2000-01-01

    Full Text Available Based on discrete chaotic dynamics algorithms different patterns in a form of mandalas have been generated. This fact gives us the possibility to make a link between mechanism of biochemical reaction dynamics undergoing in brain resulted to the brain creativity process in form of mandalas. Obtained patterns can be related to the space distributed chemicals according to the law of extended principle of maximum entropy, consideration of the information exchange during biochemical transformations, mass conservation law and discrete chaotic dynamics principles.

  3. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    Energy Technology Data Exchange (ETDEWEB)

    Somlai-Schweiger, I., E-mail: ian.somlai@tum.de; Ziegler, S. I. [Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, München 81675 (Germany)

    2015-04-15

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm{sup 3} and 10 × 10 × 10 mm{sup 3}. For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO{sub 4}. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from

  4. Synchronous Generator Model Parameter Estimation Based on Noisy Dynamic Waveforms

    Science.gov (United States)

    Berhausen, Sebastian; Paszek, Stefan

    2016-01-01

    In recent years, there have occurred system failures in many power systems all over the world. They have resulted in a lack of power supply to a large number of recipients. To minimize the risk of occurrence of power failures, it is necessary to perform multivariate investigations, including simulations, of power system operating conditions. To conduct reliable simulations, the current base of parameters of the models of generating units, containing the models of synchronous generators, is necessary. In the paper, there is presented a method for parameter estimation of a synchronous generator nonlinear model based on the analysis of selected transient waveforms caused by introducing a disturbance (in the form of a pseudorandom signal) in the generator voltage regulation channel. The parameter estimation was performed by minimizing the objective function defined as a mean square error for deviations between the measurement waveforms and the waveforms calculated based on the generator mathematical model. A hybrid algorithm was used for the minimization of the objective function. In the paper, there is described a filter system used for filtering the noisy measurement waveforms. The calculation results of the model of a 44 kW synchronous generator installed on a laboratory stand of the Institute of Electrical Engineering and Computer Science of the Silesian University of Technology are also given. The presented estimation method can be successfully applied to parameter estimation of different models of high-power synchronous generators operating in a power system.

  5. Corporate Investment Dynamic Control System Based on Chaos Cycle Perturbations

    Directory of Open Access Journals (Sweden)

    Yanyan Gao

    2014-11-01

    Full Text Available It exists some issues such as the low predict accuracy and a bad convergence performance to predict business investment with BP neural network algorithm. This paper presents a predictive model of business investment based on improved artificial bee colony and chaos periodic disturbance optimizing BP neural network algorithm. At first, use Boltzmann selection strategy and group behaviour control strategy to optimize the artificial bee colony algorithm, and then use the improved algorithm to transform BP neural network algorithm’s optimized parameters into optimization process of artificial bee colony algorithm to reduce the training error of the original algorithm. Finally, use chaotic optimized Logistic mapping enables BP neural network out of the local minimum point in the training process based on secondary chaotic cycle perturbation strategies. Simulation results show that the proposed predictive model of investment in the enterprise based on improved artificial bee colony and chaos periodic disturbance optimizing BP neural network algorithm shows higher predict accuracy and better convergence than normal BP neural network algorithm.

  6. A Dynamic Object Behavior Model and Implementation Based on Computational Reflection

    Institute of Scientific and Technical Information of China (English)

    HE Cheng-wan; HE Fei; HE Ke-qing

    2005-01-01

    A dynamic object behavior model based on computational reflection is proposed. This model consists of function level and meta level, the meta objects in meta level manage the base objects and behaviors in function level, including dynamic binding and unbinding of base object and behavior.We implement this model with RoleJava Language, which is our self linguistic extension of the Java Language. Meta Objects are generated automatically at compile-time, this makes the reflecton mechanism transparent to programmers. Finally an example applying this model to a banking system is presented.

  7. The Adjoint Method for Gradient-based Dynamic Optimization of UV Flash Processes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Capolei, Andrea; Jørgensen, John Bagterp

    2017-01-01

    This paper presents a novel single-shooting algorithm for gradient-based solution of optimal control problems with vapor-liquid equilibrium constraints. Dynamic optimization of UV flash processes is relevant in nonlinear model predictive control of distillation columns, certain two-phase flow pro......-component flash process which demonstrate the importance of the optimization solver, the compiler, and the linear algebra software for the efficiency of dynamic optimization of UV flash processes....

  8. Assessment of the depth of anesthesia based on symbolic dynamics of the EEG

    OpenAIRE

    Tupaika, Nadine; Vallverdú Ferrer, Montserrat; Jospin, Mathieu; Jensen, Erik Weber; Struys, Michel M. R. F.; Vereecke, Hugo E. M.; Voss, Andreas; Caminal Magrans, Pere

    2010-01-01

    Methodologies based on symbolic dynamics have successfully demonstrated to reflect the nonlinear behavior of biological signals. In the present study, symbolic dynamics was applied to the electroencephalogram (EEG) in order to describe the level of depth of anesthesia. The EEG was transformed to symbol sequences. Words of three symbols were built from this symbolic series. The results obtained from the EEGs of 36 patients undergoing anesthesia showed that the probabilities of the ...

  9. Rapid solidification and dynamic compaction of Ni-base superalloy powders

    Science.gov (United States)

    Field, R. D.; Hales, S. J.; Powers, W. O.; Fraser, H. L.

    1984-01-01

    A Ni-base superalloy containing 13Al-9Mo-2Ta (in at. percent) has been characterized in both the rapidly solidified condition and after dynamic compaction. Dynamically compacted specimens were examined in the as-compacted condition and observations related to current theories of interparticle bonding. In addition, the recrystallization behavior of the compacted material at relatively low temperature (about 0.5-0.75 Tm) was investigated.

  10. Dynamic Recognition of Driver’s Propensity Based on GPS Mobile Sensing Data and Privacy Protection

    OpenAIRE

    Xiaoyuan Wang; Jianqiang Wang; Jinglei Zhang; Jingheng Wang

    2016-01-01

    Driver’s propensity is a dynamic measurement of driver’s emotional preference characteristics in driving process. It is a core parameter to compute driver’s intention and consciousness in safety driving assist system, especially in vehicle collision warning system. It is also an important influence factor to achieve the Driver-Vehicle-Environment Collaborative Wisdom and Control macroscopically. In this paper, dynamic recognition model of driver’s propensity based on support vector machine is...

  11. Dynamic spectro-polarimeter based on a modified Michelson interferometric scheme.

    Science.gov (United States)

    Dembele, Vamara; Jin, Moonseob; Baek, Byung-Joon; Kim, Daesuk

    2016-06-27

    A simple dynamic spectro-polarimeter based on a modified Michelson interferometric scheme is described. The proposed system can extract a spectral Stokes vector of a transmissive anisotropic object. Detail theoretical background is derived and experiments are conducted to verify the feasibility of the proposed novel snapshot spectro-polarimeter. The proposed dynamic spectro-polarimeter enables us to extract highly accurate spectral Stokes vector of any transmissive anisotropic object with a frame rate of more than 20Hz.

  12. LOCALIZATION AND RECOGNITION OF DYNAMIC HAND GESTURES BASED ON HIERARCHY OF MANIFOLD CLASSIFIERS

    OpenAIRE

    M. Favorskaya; A. Nosov; A. Popov

    2015-01-01

    Generally, the dynamic hand gestures are captured in continuous video sequences, and a gesture recognition system ought to extract the robust features automatically. This task involves the highly challenging spatio-temporal variations of dynamic hand gestures. The proposed method is based on two-level manifold classifiers including the trajectory classifiers in any time instants and the posture classifiers of sub-gestures in selected time instants. The trajectory classifiers contain skin dete...

  13. First principles based multiparadigm modeling of electronic structures and dynamics

    Science.gov (United States)

    Xiao, Hai

    Electronic structures and dynamics are the key to linking the material composition and structure to functionality and performance. An essential issue in developing semiconductor devices for photovoltaics is to design materials with optimal band gaps and relative positioning of band levels. Approximate DFT methods have been justified to predict band gaps from KS/GKS eigenvalues, but the accuracy is decisively dependent on the choice of XC functionals. We show here for CuInSe2 and CuGaSe2, the parent compounds of the promising CIGS solar cells, conventional LDA and GGA obtain gaps of 0.0-0.01 and 0.02-0.24 eV (versus experimental values of 1.04 and 1.67 eV), while the historically first global hybrid functional, B3PW91, is surprisingly the best, with band gaps of 1.07 and 1.58 eV. Furthermore, we show that for 27 related binary and ternary semiconductors, B3PW91 predicts gaps with a MAD of only 0.09 eV, which is substantially better than all modern hybrid functionals, including B3LYP (MAD of 0.19 eV) and screened hybrid functional HSE06 (MAD of 0.18 eV). The laboratory performance of CIGS solar cells (> 20% efficiency) makes them promising candidate photovoltaic devices. However, there remains little understanding of how defects at the CIGS/CdS interface affect the band offsets and interfacial energies, and hence the performance of manufactured devices. To determine these relationships, we use the B3PW91 hybrid functional of DFT with the AEP method that we validate to provide very accurate descriptions of both band gaps and band offsets. This confirms the weak dependence of band offsets on surface orientation observed experimentally. We predict that the CBO of perfect CuInSe2/CdS interface is large, 0.79 eV, which would dramatically degrade performance. Moreover we show that band gap widening induced by Ga adjusts only the VBO, and we find that Cd impurities do not significantly affect the CBO. Thus we show that Cu vacancies at the interface play the key role in

  14. Using GPS technology to (re-examine operational definitions of ‘neighbourhood’ in place-based health research

    Directory of Open Access Journals (Sweden)

    Boruff Bryan J

    2012-06-01

    Full Text Available Abstract Background Inconsistencies in research findings on the impact of the built environment on walking across the life course may be methodologically driven. Commonly used methods to define ‘neighbourhood’, from which built environment variables are measured, may not accurately represent the spatial extent to which the behaviour in question occurs. This paper aims to provide new methods for spatially defining ‘neighbourhood’ based on how people use their surrounding environment. Results Informed by Global Positioning Systems (GPS tracking data, several alternative neighbourhood delineation techniques were examined (i.e., variable width, convex hull and standard deviation buffers. Compared with traditionally used buffers (i.e., circular and polygon network, differences were found in built environment characteristics within the newly created ‘neighbourhoods’. Model fit statistics indicated that exposure measures derived from alternative buffering techniques provided a better fit when examining the relationship between land-use and walking for transport or leisure. Conclusions This research identifies how changes in the spatial extent from which built environment measures are derived may influence walking behaviour. Buffer size and orientation influences the relationship between built environment measures and walking for leisure in older adults. The use of GPS data proved suitable for re-examining operational definitions of neighbourhood.

  15. Comparison of Vital Statistics Definitions of Suicide against a Coroner Reference Standard: A Population-Based Linkage Study.

    Science.gov (United States)

    Gatov, Evgenia; Kurdyak, Paul; Sinyor, Mark; Holder, Laura; Schaffer, Ayal

    2018-03-01

    We sought to determine the utility of health administrative databases for population-based suicide surveillance, as these data are generally more accessible and more integrated with other data sources compared to coroners' records. In this retrospective validation study, we identified all coroner-confirmed suicides between 2003 and 2012 in Ontario residents aged 21 and over and linked this information to Statistics Canada's vital statistics data set. We examined the overlap between the underlying cause of death field and secondary causes of death using ICD-9 and ICD-10 codes for deliberate self-harm (i.e., suicide) and examined the sociodemographic and clinical characteristics of misclassified records. Among 10,153 linked deaths, there was a very high degree of overlap between records coded as deliberate self-harm in the vital statistics data set and coroner-confirmed suicides using both ICD-9 and ICD-10 definitions (96.88% and 96.84% sensitivity, respectively). This alignment steadily increased throughout the study period (from 95.9% to 98.8%). Other vital statistics diagnoses in primary fields included uncategorised signs and symptoms. Vital statistics records that were misclassified did not differ from valid records in terms of sociodemographic characteristics but were more likely to have had an unspecified place of injury on the death certificate ( P statistics and coroner classification of suicide deaths suggests that health administrative data can reliably be used to identify suicide deaths.

  16. Isolated clinic hypertension: diagnostic criteria based on 24-h blood pressure definition.

    Science.gov (United States)

    Vinyoles, Ernest; Rodriguez-Blanco, Teresa; de la Sierra, Alejandro; Felip, Angela; Banegas, José R; de la Cruz, Juan J; Gorostidi, Manuel; Sobrino, Javier; Segura, Julián; Roca-Cusachs, Alex; Ruilope, Luís M

    2010-12-01

    The use of diagnostic criteria based on 24-h ambulatory blood pressure (BP) values could improve prognostic value by incorporating night BP, minimize biases and improve the diagnostic reproducibility of isolated clinic hypertension (ICH). We estimate the 24-h BP cut-off points that best discriminate and predict the two diagnostic thresholds of mean daytime BP for ICH (135/85 and 130/80 mmHg). Cross-sectional, comparative, multicentre study in 6176 untreated hypertensive patients, whose BP was measured by ambulatory BP monitoring. ICH was defined with an office BP of ≥140/≥90 mmHg and a daytime BP of <135/<85 mmHg (ICH1) or <130/80 mmHg (ICH2). Sensitivity, specificity, positive likelihood ratio (LR+), odds ratio (OR), error rate, predictive values, κ values and 95% confidence interval were calculated for each possible cut-off point for ICH1 and ICH2. One thousand eight hundred and seven patients (29.2%) and 960 patients (15.5%) met ICH1 and ICH2 criteria, respectively. The 24-h BP cut-off points that best predict ICH1 and ICH2 are less than 132/82 mmHg (sensitivity: 93.6%, specificity: 94.3%, LR+: 16.6, OR: 1367.1, error rate: 5.9, κ 0.86) and less than 127/77 mmHg (sensitivity: 90.8%, specificity: 97.4%, LR+: 34.6, OR: 1041.5, error rate: 3.6,κ 0.86), respectively. These values achieved the best balance of sensitivity and specificity, together with the highest values of LR+ and OR and the lowest error rate. The 24-h BP cut-off point that best predicts the daytime criterion of less than 135/85 and less than 130/80 mmHg are 132/82 and 127/77 mmHg, respectively. These 24-h cut-off points may add value to ambulatory blood pressure monitoring for both diagnostic and management future decisions.

  17. Experimental evaluation of optimal Vehicle Dynamic Control based on the State Dependent Riccati Equation technique

    NARCIS (Netherlands)

    Alirezaei, M.; Kanarachos, S.A.; Scheepers, B.T.M.; Maurice, J.P.

    2013-01-01

    Development and experimentally evaluation of an optimal Vehicle Dynamic Control (VDC) strategy based on the State Dependent Riccati Equation (SDRE) control technique is presented. The proposed nonlinear controller is based on a nonlinear vehicle model with nonlinear tire characteristics. A novel

  18. Dynamic neural network-based methods for compensation of nonlinear effects in multimode communication lines

    Science.gov (United States)

    Sidelnikov, O. S.; Redyuk, A. A.; Sygletos, S.

    2017-12-01

    We consider neural network-based schemes of digital signal processing. It is shown that the use of a dynamic neural network-based scheme of signal processing ensures an increase in the optical signal transmission quality in comparison with that provided by other methods for nonlinear distortion compensation.

  19. International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines

    CERN Document Server

    Belyaev, Alexander; Krommer, Michael

    2017-01-01

    The papers in this volume present and discuss the frontiers in the mechanics of controlled machines and structures. They are based on papers presented at the International Workshop on Advanced Dynamics and Model Based Control of Structures and Machines held in Vienna in September 2015. The workshop continues a series of international workshops held in Linz (2008) and St. Petersburg (2010).

  20. Obesity as a clinical and public health problem: is there a need for a new definition based on lipotoxicity effects?

    Science.gov (United States)

    Sørensen, Thorkild I A; Virtue, Sam; Vidal-Puig, Antonio

    2010-03-01

    The risk functions for obesity (defined as the quantitative relation between degree of obesity throughout its range and the risk of health problems) have been used to define 'obesity' as an excess storage of fat in the body to such an extent that it causes health problems leading to increased mortality. The lipotoxicity theory implies that the fat stored in droplets of triglycerides in the cells are biologically inert and that the metabolic dysfunctions are primarily due to the increased exposure of the cells to fatty acids. If this is true, it has profound implications for the interpretations of the multiple epidemiological studies of the risk functions. It is obvious from all these studies that the sizes of the fat depots are risk indicators of health effects in various ways. Paradoxically, the sizes of the fat stores are also indicators of the preceding implementation of the ability of the body to protect itself against the toxic effects of the free fatty acids. The current risk of metabolic dysfunctions appears to be determined by the balance between the rate of loading of the body with fatty acids and the rate of eliminating the fatty acids by either triglyceride storage or oxidation. The progress in the development of the dysfunction then depends on the persistence of the imbalance leading to future cumulative exposure of the cells to the toxic effects of the fatty acids rather than on the current size of the fat depots. This may be considered as a reason for changing the definition of obesity to one based on better estimates of future risks of health problems derived from later metabolic dysfunctions rather than on the past coping with the exposure to the fatty acids by storage as triglycerides. Implementation of such definition would require a test that measures this residual capacity to avoid excess exposure of the cells to the fatty acids before the metabolic dysfunctions have emerged. In analogy with the glucose tolerance test, a fatty acid tolerance