WorldWideScience

Sample records for model threaded cognition

  1. A Model of Cooperative Threads

    CERN Document Server

    Abadi, Martín

    2010-01-01

    We develop a model of concurrent imperative programming with threads. We focus on a small imperative language with cooperative threads which execute without interruption until they terminate or explicitly yield control. We define and study a trace-based denotational semantics for this language; this semantics is fully abstract but mathematically elementary. We also give an equational theory for the computational effects that underlie the language, including thread spawning. We then analyze threads in terms of the free algebra monad for this theory.

  2. Threaded Cognition: An Integrated Theory of Concurrent Multitasking

    Science.gov (United States)

    Salvucci, Dario D.; Taatgen, Niels A.

    2008-01-01

    The authors propose the idea of threaded cognition, an integrated theory of concurrent multitasking--that is, performing 2 or more tasks at once. Threaded cognition posits that streams of thought can be represented as threads of processing coordinated by a serial procedural resource and executed across other available resources (e.g., perceptual…

  3. Analysis of Modeling Parameters on Threaded Screws.

    Energy Technology Data Exchange (ETDEWEB)

    Vigil, Miquela S. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brake, Matthew Robert [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Vangoethem, Douglas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-06-01

    Assembled mechanical systems often contain a large number of bolted connections. These bolted connections (joints) are integral aspects of the load path for structural dynamics, and, consequently, are paramount for calculating a structure's stiffness and energy dissipation prop- erties. However, analysts have not found the optimal method to model appropriately these bolted joints. The complexity of the screw geometry cause issues when generating a mesh of the model. This paper will explore different approaches to model a screw-substrate connec- tion. Model parameters such as mesh continuity, node alignment, wedge angles, and thread to body element size ratios are examined. The results of this study will give analysts a better understanding of the influences of these parameters and will aide in finding the optimal method to model bolted connections.

  4. Radiative transfer in cylindrical threads with incident radiation VII. Multi-thread models

    CERN Document Server

    Labrosse, N

    2016-01-01

    We solved the radiative transfer and statistical equilibrium equations in a two-dimensional cross-section of a cylindrical structure oriented horizontally and lying above the solar surface. The cylinder is filled with a mixture of hydrogen and helium and is illuminated at a given altitude from the solar disc. We constructed simple models made from a single thread or from an ensemble of several threads along the line of sight. This first use of two-dimensional, multi-thread fine structure modelling combining hydrogen and helium radiative transfer allowed us to compute synthetic emergent spectra from cylindrical structures and to study the effect of line-of-sight integration of an ensemble of threads under a range of physical conditions. We analysed the effects of variations in temperature distribution and in gas pressure. We considered the effect of multi-thread structures within a given field of view and the effect of peculiar velocities between the structures in a multi-thread model. We compared these new mo...

  5. Model Checking with Multi-Threaded IC3 Portfolios

    Science.gov (United States)

    2015-01-15

    Model Checking with Multi-Threaded IC3 Portfolios Sagar Chaki and Derrick Karimi Software Engineering Institute, Carnegie Mellon University {chaki...different runs varies randomly depending on the thread interleaving. The use of a portfolio of solvers to maximize the likelihood of a quick solution is...investigated. Using the Extreme Value theorem, the runtime of each variant, as well as their portfolios is analysed statistically. A formula for the

  6. The mathematical model of thread unrolling from a bobbin

    Directory of Open Access Journals (Sweden)

    S. M. Tenenbaum

    2014-01-01

    Full Text Available I. Introduction The subject of research in this work is a process of thread unrolling from a bobbin. The mathematical model of this process considering motion of thread peace on a bobbin and unrolled peace is proposed. The dimension of system of differential equations for this model is constant during deploying.The relevance to simulate this process for design of Heliogyro-like solar sails (Heliogyro [1], BMSTU-Sail [2] is proved. The paper briefly characterizes a blade for such solar sail as a simulation object. It proves the possibility for using a flexible thread model for a long blade because of very small blade thickness (less than 10 μm [3] relative to blade width and the phenomena of Koriolis forces [4] that lead to buckling failure of blade flatness.The major features of the proposed model are:-- simulated as a motion of the thread piece both being on a bobbin and its unrolled peace;-- splitting a thread length into nodes does not depend on the demand to ensure a sufficient number of nodes on a single thread turn on the coil;-- because of avoiding a problem of contact between the thread and bobbin a stable integration of motion equations is provided by the conventional Runge-Kutta method of fourth order with a constant step [5];-- in the course of solution the number of freedom degrees (number of motion equation is constant, thereby simplifying a calculation algorithm.The closest mathematical model is proposed in [6].The scientific novelty of this research is the approach to solving the problem of unrolling thread from a bobbin using a constant number of motion equations while preserving real kinematics coiling process.II. Problem formulationIn this section the problem of unrolling thread with length L from a bobbin of radius r is posed while any kind of forces are acting on the unrolled peace of thread. Moreover, the law of bobbin rotation φ(t assumed to be known with the proviso that the model can be modified if φ(t is the result of

  7. Multi-Thread Hydrodynamic Modeling of a Solar Flare

    CERN Document Server

    Warren, H P

    2006-01-01

    Past hydrodynamic simulations have been able to reproduce the high temperatures and densities characteristic of solar flares. These simulations, however, have not been able to account for the slow decay of the observed flare emission or the absence of blueshifts in high spectral resolution line profiles. Recent work has suggested that modeling a flare as an sequence of independently heated threads instead of as a single loop may resolve the discrepancies between the simulations and observations. In this paper we present a method for computing multi-thread, time-dependent hydrodynamic simulations of solar flares and apply it to observations of the Masuda flare of 1992 January 13. We show that it is possible to reproduce the temporal evolution of high temperature thermal flare plasma observed with the instruments on the \\textit{GOES} and \\textit{Yohkoh} satellites. The results from these simulations suggest that the heating time-scale for a individual thread is on the order of 200 s. Significantly shorter heati...

  8. Model comparison for the density structure along solar prominence threads

    Science.gov (United States)

    Arregui, I.; Soler, R.

    2015-06-01

    Context. Quiescent solar prominence fine structures are typically modelled as density enhancements, called threads, which occupy a fraction of a longer magnetic flux tube. This is justified from the spatial distribution of the imaged plasma emission or absorption of prominences at small spatial scales. The profile of the mass density along the magnetic field is unknown, however, and several arbitrary alternatives are employed in prominence wave studies. The identification and measurement of period ratios from multiple harmonics in standing transverse thread oscillations offer a remote diagnostics method to probe the density variation of these structures. Aims: We present a comparison of theoretical models for the field-aligned density along prominence fine structures. They aim to imitate density distributions in which the plasma is more or less concentrated around the centre of the magnetic flux tube. We consider Lorentzian, Gaussian, and parabolic profiles. We compare theoretical predictions based on these profiles for the period ratio between the fundamental transverse kink mode and the first overtone to obtain estimates for the density ratios between the central part of the tube and its foot-points and to assess which one would better explain observed period ratio data. Methods: Bayesian parameter inference and model comparison techniques were developed and applied. To infer the parameters, we computed the posterior distribution for the density gradient parameter that depends on the observable period ratio. The model comparison involved computing the marginal likelihood as a function of the period ratio to obtain the plausibility of each density model as a function of the observable. We also computed the Bayes factors to quantify the relative evidence for each model, given a period ratio observation. Results: A Lorentzian density profile, with plasma density concentrated around the centre of the tube, seems to offer the most plausible inversion result. A

  9. Model comparison for the density structure along solar prominence threads

    CERN Document Server

    Arregui, I

    2015-01-01

    Quiescent solar prominence fine structures are typically modelled as density enhancements, called threads, which occupy a fraction of a longer magnetic flux tube. The profile of the mass density along the magnetic field is however unknown and several arbitrary alternatives are employed in prominence wave studies. We present a comparison of theoretical models for the field-aligned density along prominence fine structures. We consider Lorentzian, Gaussian, and parabolic profiles. We compare their theoretical predictions for the period ratio between the fundamental transverse kink mode and the first overtone to obtain estimates for the ratio of densities between the central part of the tube and its foot-points and to assess which one would better explain observed period ratio data. Bayesian parameter inference and model comparison techniques are developed and applied. Parameter inference requires the computation of the posterior distribution for the density gradient parameter conditional on the observable period...

  10. COOPERATIVE MODEL FOR OPTIMIZATION OF EXECUTION OF THREADS ON MULTI-CORE SYSTEM

    Directory of Open Access Journals (Sweden)

    A. A. Prihozhy

    2014-01-01

    Full Text Available The problem of the increase of efficiency of multi-thread applications on multi-core systems is investigated. The optimization cooperative model of threads execution has been proposed. It optimizes the execution order of the  computational operations and the operations of data exchange, decreases the overall time of the multithread application  execution by means of the reduction of the critical path in the concurrent algorithm graph, increases the application throughput at the growth of the number of threads, and excludes the competition among threads that is specific for preemptive multitasking...............................

  11. Mathematical Model of Load Pass and Prediction of Fatigue Life on Bolt Threads with Reduced Lead

    Science.gov (United States)

    Asayama, Yukiteru

    A mathematical model is proposed in order to elucidate the mechanism that the fatigue strength of external threads increases by reducing the lead on a thread system such as a bolt and nut. The model is constructed from the concept that a local strain proportional to the reducing degree of the lead, although the local strain is at first produced in the bolt thread farthest from the bearing surface of the nut, is induced in each thread root with an increase of applied load. The fatigue life predicted from the mathematical model shows good agreement with the experimental fatigue life of cadmium-plated external threads with the reduced lead on the material having strength as high as 1270MPa. The model can provide useful suggestions for the design of fasteners for aerospace, which are required to satisfy severe requirements of fatigue strengths and dimensions.

  12. How Cognitive Requirement of Prompt and Time in Course Are Correlated with Intersubjectivity within Threaded Discussions

    Science.gov (United States)

    Hall, Barbara M.

    2011-01-01

    Threaded discussions represent conversational turn-taking in asynchronous, online learning environments. Given the crucial role that discussions play in the construction of knowledge within an online course, the quality of the interaction that occurs within threaded discussions is important to achieving the learning objectives of the designed…

  13. A threaded Java concurrent implementation of the Monte-Carlo Metropolis Ising model.

    Science.gov (United States)

    Castañeda-Marroquín, Carlos; de la Puente, Alfonso Ortega; Alfonseca, Manuel; Glazier, James A; Swat, Maciej

    2009-06-01

    This paper describes a concurrent Java implementation of the Metropolis Monte-Carlo algorithm that is used in 2D Ising model simulations. The presented method uses threads, monitors, shared variables and high level concurrent constructs that hide the low level details. In our algorithm we assign one thread to handle one spin flip attempt at a time. We use special lattice site selection algorithm to avoid two or more threads working concurently in the region of the lattice that "belongs" to two or more different spins undergoing spin-flip transformation. Our approach does not depend on the current platform and maximizes concurrent use of the available resources.

  14. Modeling and Analysis of Thread-Pools in an Industrial Communication Platform

    Science.gov (United States)

    de Boer, Frank S.; Grabe, Immo; Jaghoori, Mohammad Mahdi; Stam, Andries; Yi, Wang

    Thread pools are often used as a pattern to increase the throughput and responsiveness of software systems. Implementations of thread pools may differ considerably from each other, which urges the need to analyze these differences in a formal manner. We use an object-oriented paradigm to model different thread pools in the context of the ASK system, an industrial communication platform. We use behavioral interfaces, high-level behavioral specifications for the objects, as a starting-point for analysis. Based on these behavioral interfaces, functional aspects are modeled in Creol, a high-level modeling language for concurrent objects. We use UPPAAL to create real-time models and to perform schedulability analysis with respect to the behavioral interfaces. We finally check conformance between the real-time and Creol models using test-cases generated from the behavioral interfaces.

  15. Hagfish slime threads as a biomimetic model for high performance protein fibres.

    Science.gov (United States)

    Fudge, Douglas S; Hillis, Sonja; Levy, Nimrod; Gosline, John M

    2010-09-01

    Textile manufacturing is one of the largest industries in the world, and synthetic fibres represent two-thirds of the global textile market. Synthetic fibres are manufactured from petroleum-based feedstocks, which are becoming increasingly expensive as demand for finite petroleum reserves continues to rise. For the last three decades, spider silks have been held up as a model that could inspire the production of protein fibres exhibiting high performance and ecological sustainability, but unfortunately, artificial spider silks have yet to fulfil this promise. Previous work on the biomechanics of protein fibres from the slime of hagfishes suggests that these fibres might be a superior biomimetic model to spider silks. Based on the fact that the proteins within these 'slime threads' adopt conformations that are similar to those in spider silks when they are stretched, we hypothesized that draw processing of slime threads should yield fibres that are comparable to spider dragline silk in their mechanical performance. Here we show that draw-processed slime threads are indeed exceptionally strong and tough. We also show that post-drawing steps such as annealing, dehydration and covalent cross-linking can dramatically improve the long-term dimensional stability of the threads. The data presented here suggest that hagfish slime threads are a model that should be pursued in the quest to produce fibres that are ecologically sustainable and economically viable.

  16. Hagfish slime threads as a biomimetic model for high performance protein fibres

    Energy Technology Data Exchange (ETDEWEB)

    Fudge, Douglas S; Hillis, Sonja [Department of Integrative Biology, University of Guelph, Guelph, Ontario, N1G 2W1 (Canada); Levy, Nimrod; Gosline, John M, E-mail: dfudge@uoguelph.c [Department of Zoology, University of British Columbia, Vancouver, British Columbia, V6T 1Z4 (Canada)

    2010-09-15

    Textile manufacturing is one of the largest industries in the world, and synthetic fibres represent two-thirds of the global textile market. Synthetic fibres are manufactured from petroleum-based feedstocks, which are becoming increasingly expensive as demand for finite petroleum reserves continues to rise. For the last three decades, spider silks have been held up as a model that could inspire the production of protein fibres exhibiting high performance and ecological sustainability, but unfortunately, artificial spider silks have yet to fulfil this promise. Previous work on the biomechanics of protein fibres from the slime of hagfishes suggests that these fibres might be a superior biomimetic model to spider silks. Based on the fact that the proteins within these 'slime threads' adopt conformations that are similar to those in spider silks when they are stretched, we hypothesized that draw processing of slime threads should yield fibres that are comparable to spider dragline silk in their mechanical performance. Here we show that draw-processed slime threads are indeed exceptionally strong and tough. We also show that post-drawing steps such as annealing, dehydration and covalent cross-linking can dramatically improve the long-term dimensional stability of the threads. The data presented here suggest that hagfish slime threads are a model that should be pursued in the quest to produce fibres that are ecologically sustainable and economically viable.

  17. Optimising GPR modelling: A practical, multi-threaded approach to 3D FDTD numerical modelling

    Science.gov (United States)

    Millington, T. M.; Cassidy, N. J.

    2010-09-01

    The demand for advanced interpretational tools has lead to the development of highly sophisticated, computationally demanding, 3D GPR processing and modelling techniques. Many of these methods solve very large problems with stepwise methods that utilise numerically similar functions within iterative computational loops. Problems of this nature are readily parallelised by splitting the computational domain into smaller, independent chunks for direct use on cluster-style, multi-processor supercomputers. Unfortunately, the implications of running such facilities, as well as time investment needed to develop the parallel codes, means that for most researchers, the use of these advanced methods is too impractical. In this paper, we propose an alternative method of parallelisation which exploits the capabilities of the modern multi-core processors (upon which today's desktop PCs are built) by multi-threading the calculation of a problem's individual sub-solutions. To illustrate the approach, we have applied it to an advanced, 3D, finite-difference time-domain (FDTD) GPR modelling tool in which the calculation of the individual vector field components is multi-threaded. To be of practical use, the FDTD scheme must be able to deliver accurate results with short execution times and we, therefore, show that the performance benefits of our approach can deliver runtimes less than half those of the more conventional, serial programming techniques. We evaluate implementations of the technique using different programming languages (e.g., Matlab, Java, C++), which will facilitate the construction of a flexible modelling tool for use in future GPR research. The implementations are compared on a variety of typical hardware platforms, having between one and eight processing cores available, and also a modern Graphical Processing Unit (GPU)-based computer. Our results show that a multi-threaded xyz modelling approach is easy to implement and delivers excellent results when implemented

  18. Bolt Thread Stress Optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2012-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...

  19. Bolt Thread Stress Optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2012-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in this paper. Thread root design controls the stress concentration factor...... of threads and therefore indirectly the bolt fatigue life. The root shape is circular, and from shape optimization for minimum stress concentration it is well known that the circular shape is seldom optimal. An axisymmetric Finite Element (FE) formulation is used to analyze the bolted connection, and a study...... is performed to establish the need for contact modeling with regard to finding the correct stress concentration factor. Optimization is performed with a simple parameterization with two design variables. Stress reduction of up to 9% is found in the optimization process, and some similarities are found...

  20. Performance Evaluation of Parallel Message Passing and Thread Programming Model on Multicore Architectures

    CERN Document Server

    Hasta, D T

    2010-01-01

    The current trend of multicore architectures on shared memory systems underscores the need of parallelism. While there are some programming model to express parallelism, thread programming model has become a standard to support these system such as OpenMP, and POSIX threads. MPI (Message Passing Interface) which remains the dominant model used in high-performance computing today faces this challenge. Previous version of MPI which is MPI-1 has no shared memory concept, and Current MPI version 2 which is MPI-2 has a limited support for shared memory systems. In this research, MPI-2 version of MPI will be compared with OpenMP to see how well does MPI perform on multicore / SMP (Symmetric Multiprocessor) machines. Comparison between OpenMP for thread programming model and MPI for message passing programming model will be conducted on multicore shared memory machine architectures to see who has a better performance in terms of speed and throughput. Application used to assess the scalability of the evaluated parall...

  1. Thread mapping using system-level model for shared memory multicores

    Science.gov (United States)

    Mitra, Reshmi

    Exploring thread-to-core mapping options for a parallel application on a multicore architecture is computationally very expensive. For the same algorithm, the mapping strategy (MS) with the best response time may change with data size and thread counts. The primary challenge is to design a fast, accurate and automatic framework for exploring these MSs for large data-intensive applications. This is to ensure that the users can explore the design space within reasonable machine hours, without thorough understanding on how the code interacts with the platform. Response time is related to the cycles per instructions retired (CPI), taking into account both active and sleep states of the pipeline. This work establishes a hybrid approach, based on Markov Chain Model (MCM) and Model Tree (MT) for system-level steady state CPI prediction. It is designed for shared memory multicore processors with coarse-grained multithreading. The thread status is represented by the MCM states. The program characteristics are modeled as the transition probabilities, representing the system moving between active and suspended thread states. The MT model extrapolates these probabilities for the actual application size (AS) from the smaller AS performance. This aspect of the framework, along with, the use of mathematical expressions for the actual AS performance information, results in a tremendous reduction in the CPI prediction time. The framework is validated using an electromagnetics application. The average performance prediction error for steady state CPI results with 12 different MSs is less than 1%. The total run time of model is of the order of minutes, whereas the actual application execution time is in terms of days.

  2. A new Java Thread model for concurrent programming of real-time systems

    OpenAIRE

    Hilderink, G.H.; Broenink, Johannes F.; Bakkers, André

    1998-01-01

    The Java ™ Virtual Machine (JVM) provides a high degree of platform independence, but being an interpreter, Java has a poor system performance. New compiler techniques and Java processors will gradually improve the performance of Java, but despite these developments, Java is still far from real-time. We propose the Communicating Java Threads (CJT) model, which eliminates several shortcomings, such as Java's non-deterministic behavior, Java's monitor weakness, and lack of reactiveness for real...

  3. Formalizing and Checking Thread Refinement for Data-Race-Free Execution Models (Extended Version)

    OpenAIRE

    Poetzl, Daniel; Kroening, Daniel

    2015-01-01

    When optimizing a thread in a concurrent program (either done manually or by the compiler), it must be guaranteed that the resulting thread is a refinement of the original thread. Most theories of valid optimizations are formulated in terms of valid syntactic transformations on the program code, or in terms of valid transformations on thread execution traces. We present a new theory formulated instead in terms of the state of threads at synchronization operations, and show that it provides se...

  4. Formalizing and Checking Thread Refinement for Data-Race-Free Execution Models (Extended Version)

    OpenAIRE

    Poetzl, Daniel; Kroening, Daniel

    2015-01-01

    When optimizing a thread in a concurrent program (either done manually or by the compiler), it must be guaranteed that the resulting thread is a refinement of the original thread. Most theories of valid optimizations are formulated in terms of valid syntactic transformations on the program code, or in terms of valid transformations on thread execution traces. We present a new theory formulated instead in terms of the state of threads at synchronization operations, and show that it provides se...

  5. Java Threads

    National Research Council Canada - National Science Library

    Gillespie, Thom

    1997-01-01

    ... useful for a working programmer moving from C++ to Java. Threads are what makes Java a particularly useful language for multiprocessing--the ability to appear to do more than one thing at a time--which is what the Internet is all about. The tricky part of threads is that the concept is new for most users. Oaks offers a very clear discussion of how t...

  6. Modeling of Threading Dislocation Density Reduction in Porous III-Nitride Layers

    Science.gov (United States)

    Artemiev, Dmitry M.; Orlova, Tatiana S.; Bougrov, Vladislav E.; Odnoblyudov, Maxim A.; Romanov, Alexei E.

    2015-05-01

    In this work, we report on the results of the theoretical analysis of threading dislocation (TD) density reduction in porous III-nitride layers grown in polar orientation. The reaction-kinetics model originally developed for describing TD evolution in growing bulk layers has been expanded to the case of the porous layer. The developed model takes into account TD inclinations under the influence of the pores as well as trapping TDs into the pores. It is demonstrated that both these factors increase the probability of dislocation reactions thus reducing the total density of TDs. The mean pore diameter acts as an effective interaction radius for the reactions among TDs. The model includes the main experimentally observed features of TD evolution in porous III-nitride layers.

  7. A thread calculus with molecular dynamics

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2010-01-01

    We present a theory of threads, interleaving of threads, and interaction between threads and services with features of molecular dynamics, a model of computation that bears on computations in which dynamic data structures are involved. Threads can interact with services of which the states consist o

  8. A cognitive model's view of animal cognition

    Directory of Open Access Journals (Sweden)

    Sidney D'MELLO, Stan FRANKLIN

    2011-08-01

    Full Text Available Although it is a relatively new field of study, the animal cognition literature is quite extensive and difficult to synthesize. This paper explores the contributions a comprehensive, computational, cognitive model can make toward organizing and assimilating this literature, as well as toward identifying important concepts and their interrelations. Using the LIDA model as an example, a framework is described within which to integrate the diverse research in animal cognition. Such a framework can provide both an ontology of concepts and their relations, and a working model of an animal’s cognitive processes that can compliment active empirical research. In addition to helping to account for a broad range of cognitive processes, such a model can help to comparatively assess the cognitive capabilities of different animal species. After deriving an ontology for animal cognition from the LIDA model, we apply it to develop the beginnings of a database that maps the cognitive facilities of a variety of animal species. We conclude by discussing future avenues of research, particularly the use of computational models of animal cognition as valuable tools for hypotheses generation and testing [Current Zoology 57 (4: 499–513, 2011].

  9. Design and research of calculation models of the tooth profile angles of thread milling cutter with helical flutes

    Directory of Open Access Journals (Sweden)

    O. V. Malkov

    2014-01-01

    Full Text Available The review of manufacturer's programs to make thread milling cutters has shown that most of milling cutters are produced with the helical flutes with the ω slope angle within the range of 10° ...30°. Thus, thread milling cutters, made of high speed steels, essentially, are not produced. In Russia there is GOST 1336-77, to regulate the parameters of thread milling cutter shaving with a straight flutes, made of high speed steels.It is established that available rake and clearance angles, and inclination angle of helical flutes at the accepted values of pitch and diameter of the tool lead to obtaining the angles of the tooth profile other than 30 degrees, thus requiring the calculation of angles β1 and β2 in each case of design. In the general case we have an asymmetrical profile with respect to the axis passing through the top of the tooth.Using the CATIA V5 R17 software, a geometric model that allows us to determine the angles of the tooth profile of thread milling cutter with helical flutes has been developed. The model research has been conducted for geometric and design parameters of thread milling cutter, made of cemented carbide and high speed steel. The paper presents a method for constructing models and key assumptions adopted for its development.Dependences are obtained for the model with a variation of the five factors (external diameter d, step profiles, P, rake γтц, clearance α, inclination angle of helical flutes ω for thread milling cutters, made of cemented carbide and according to the model that extends the range of variation factors (d, P, γтц, ω according to GOST 1336-77. Thus, this model to have the angles of the tooth profile of thread milling cutter with helical flutes can be used both to obtain the angles profile β1 and β2 in a wide range of varying tool parameters for all types of tool materials, and to broaden the possibilities for calculation of parameters according to GOST 1336-77.

  10. When to Use Cognitive Modeling.

    Science.gov (United States)

    Harmon, Paul; Evans, Kay

    1984-01-01

    Cognitive modeling works best when teaching overt, observable activities. The basic structure of a good cognitive program includes modeling, case study exercises, social reinforcement, and transfer of training. (JB)

  11. Physical models of cognition

    Science.gov (United States)

    Zak, Michail

    1994-05-01

    This paper presents and discusses physical models for simulating some aspects of neural intelligence, and, in particular, the process of cognition. The main departure from the classical approach here is in utilization of a terminal version of classical dynamics introduced by the author earlier. Based upon violations of the Lipschitz condition at equilibrium points, terminal dynamics attains two new fundamental properties: it is spontaneous and nondeterministic. Special attention is focused on terminal neurodynamics as a particular architecture of terminal dynamics which is suitable for modeling of information flows. Terminal neurodynamics possesses a well-organized probabilistic structure which can be analytically predicted, prescribed, and controlled, and therefore which presents a powerful tool for modeling real-life uncertainties. Two basic phenomena associated with random behavior of neurodynamic solutions are exploited. The first one is a stochastic attractor—a stable stationary stochastic process to which random solutions of a closed system converge. As a model of the cognition process, a stochastic attractor can be viewed as a universal tool for generalization and formation of classes of patterns. The concept of stochastic attractor is applied to model a collective brain paradigm explaining coordination between simple units of intelligence which perform a collective task without direct exchange of information. The second fundamental phenomenon discussed is terminal chaos which occurs in open systems. Applications of terminal chaos to information fusion as well as to explanation and modeling of coordination among neurons in biological systems are discussed. It should be emphasized that all the models of terminal neurodynamics are implementable in analog devices, which means that all the cognition processes discussed in the paper are reducible to the laws of Newtonian mechanics.

  12. ThreadedComposite: A Mechanism for Building Concurrent and Parallel Ptolemy II Models

    Science.gov (United States)

    2008-12-07

    Air Force Research Lab (AFRL), the State of California Micro Program, and the following companies: Agilent, Bosch, HSBC , Lockheed-Martin, National...following companies: Agilent, Bosch, HSBC , Lockheed-Martin, National Instruments, and Toyota. ThreadedComposite Actor 2 This paper introduces a new

  13. Scheduler Activations on BSD: Sharing Thread Management Between Kernel and Application

    OpenAIRE

    Small, Christopher A.; Seltzer, Margo I.

    1995-01-01

    There are two commonly used thread models: kernel level threads and user level threads. Kernel level threads suffer from the cost of frequent user-kernel domain crossings and fixed kernel scheduling priorities. User level threads are not integrated with the kernel, blocking all threads whenever one thread is blocked. The Scheduler Activations model, proposed by Anderson et al. [ANDE91], combines kernel CPU al location decisions with application control over thread scheduling. This paper discu...

  14. Java Fair Threads

    OpenAIRE

    Boussinot, Frédéric

    2001-01-01

    Fair threads are cooperative threads run by a fair scheduler which gives them equal access to the processor. Fair threads can communicate using broadcast events, and are fully portable as their semantics does not depends on the executing platform. Fine control over fair threads execution is possible allowing the programming of specific user-defined scheduling strategies. This paper presents fair threads in the context of the Java language, and describes the API to use them. Link with reactive...

  15. Effects of strain, body mass, and thread tip preparation on the establishment of focal cerebral ischemia mouse models

    Institute of Scientific and Technical Information of China (English)

    Xuemei Chen; Yun Xu

    2008-01-01

    BACKGROUND: What are the successful factors of the establishment of the thread-blocking method for focal cerebral ischemia/reperfusion mouse models?OBJECTIVE: To study the effects of strain, body mass, and thread tip preparation for the establishment of focal cerebral ischemia mouse models by using middle cerebral artery occlusion (MCAO).DESIGN: Observational contrast animal study.SETTING: Gulou Hospital, Medical College of Nanjing University.MATERIALS: ① The following experiment was performed at the Animal Experimental Center, Gulou Hospital Affiliated to Medical College of Nanjing University from December 2006 to April 2007. Sixty male white Kunming mice, whose body masses were 18–22 g (n =40), 25–29 g (n =10) and 30–33 g (n =10), as well as 10 male C57BL/6J mice, whose body mass was 18–22 g, were provided by the Animal Experimental Center, Gulou Hospital Affiliated to Medical College of Nanjing University. All mice were 10–12 weeks old. The project received confirmed consent from the local ethics committee. ②Experimental materials: tripheryltetrazolium hydrochloride (TTC) and 0.1% poly-L-lysine were provided by Sigma Company, USA; citromint was provided by Shanghai Lingfeng Chemical Company Limited. METHODS: ① Strain comparison: Ten white Kunming mice (weighing 18–22 g) and ten C57BL/6J mice (weighing 18–22 g) were selected. ② Comparison of body mass: Thirty white Kunming mice, whose body masses were 18–22 g (n =10), 25–30 g (n =10), and 30–35 g (n =10), were divided into groups. ③ Comparison of thread tip preparation: White Kunming mice weighing 18–22 g were divided into a poly-L-lysine line group and general line group, with 10 mice in each group. Mice in these two groups, which were respectively treated with poly-L-lysine or nothing, underwent MCAO. ④ All experimental mice received MCAO. Three hours after ischemia, and 24 hours after reperfusion, neurological deficit scores were measured and a success rate of model

  16. Probabilistic thread algebra

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2015-01-01

    We add probabilistic features to basic thread algebra and its extensions with thread-service interaction and strategic interleaving. Here, threads represent the behaviours produced by instruction sequences under execution and services represent the behaviours exhibited by the components of execution

  17. Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Maqsood Muhammad

    2016-09-01

    Full Text Available The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

  18. Formal modelling of cognitive interpretation

    OpenAIRE

    Rukšenas, R.; Curzon, P; Back, J.; Blandford, A.

    2007-01-01

    We formally specify the interpretation stage in a dual state space human-computer interaction cycle. This is done by extending/reorganising our previous cognitive architecture. In particular, we focus on shape related aspects of the interpretation process associated with device input prompts. A cash-point example illustrates our approach. Using the SAL model checking environment, we show how the extended cognitive architecture facilitates detection of prompt-shape induced human error. © Sprin...

  19. Cognitive Diagnostic Modeling Using R

    Science.gov (United States)

    Ravand, Hamdollah

    2015-01-01

    Cognitive diagnostic models (CDM) have been around for more than a decade but their application is far from widespread for mainly two reasons: (1) CDMs are novel, as compared to traditional IRT models. Consequently, many researchers lack familiarity with them and their properties, and (2) Software programs doing CDMs have been expensive and not…

  20. Gender Recognition Using Cognitive Modeling

    DEFF Research Database (Denmark)

    Fagertun, Jens; Andersen, Tobias; Paulsen, Rasmus Reinhold

    2012-01-01

    In this work, we use cognitive modeling to estimate the ”gender strength” of frontal faces, a continuous class variable, superseding the traditional binary class labeling. To incorporate this continuous variable we suggest a novel linear gender classification algorithm, the Gender Strength Regres...

  1. Loading and Contact Stress Analysis on the Thread Teeth in Tubing and Casing Premium Threaded Connection

    Directory of Open Access Journals (Sweden)

    Honglin Xu

    2014-01-01

    Full Text Available Loading and contact stress distribution on the thread teeth in tubing and casing premium threaded connections are of great importance for design optimization, pretightening force control, and thread failure prevention. This paper proposes an analytical method based on the elastic mechanics. This is quite different from other papers, which mainly rely on finite element analysis. The differential equation of load distribution on the thread teeth was established according to equal pitch of the engaged thread after deformation and solved by finite difference method. Furthermore, the relation between load acting on each engaged thread and mean contact stress on its load flank is set up based on the geometric description of thread surface. By comparison, this new analytical method with the finite element analysis for a modified API 177.8 mm premium threaded connection is approved. Comparison of the contact stress on the last engaged thread between analytical model and FEM shows that the accuracy of analytical model will decline with the increase of pretightening force after the material enters into plastic deformation. However, the analytical method can meet the needs of engineering to some extent because its relative error is about 6.2%~18.1% for the in-service level of pretightening force.

  2. Producing miniature threads. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.; Robb, J.M.

    1981-11-01

    Miniature precision actuators, timers, and switches typically utilize miniature threads to provide convenient assembly, disassembly and adjustment. Thread rolling provides high-quality external threads with greater strength and lower cost than other thread-producing techniques. Tap breakage is a significant problem when 0.5 and 0.6 Unified National Miniature (UNM) threads must be produced in hard materials such as SAE K95100 high-permeability magnetic steel. Aluminum parts can be tapped with no difficulty in these sizes. Stainless steel 0.5 UNM screws break at loads of 21 lb (53 N). Thread failure occurs at thread heights of 62% full thread or lower.

  3. Thread Group Multithreading: Accelerating the Computation of an Agent-Based Power System Modeling and Simulation Tool -- C GridLAB-D

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Shuangshuang; Chassin, David P.

    2014-01-06

    GridLAB-DTM is an open source next generation agent-based smart-grid simulator that provides unprecedented capability to model the performance of smart grid technologies. Over the past few years, GridLAB-D has been used to conduct important analyses of smart grid concepts, but it is still quite limited by its computational performance. In order to break through the performance bottleneck to meet the need for large scale power grid simulations, we develop a thread group mechanism to implement highly granular multithreaded computation in GridLAB-D. We achieve close to linear speedups on multithreading version compared against the single-thread version of the same code running on general purpose multi-core commodity for a benchmark simple house model. The performance of the multithreading code shows favorable scalability properties and resource utilization, and much shorter execution time for large-scale power grid simulations.

  4. Data-mining modeling for the prediction of wear on forming-taps in the threading of steel components

    Directory of Open Access Journals (Sweden)

    Andres Bustillo

    2016-10-01

    Full Text Available An experimental approach is presented for the measurement of wear that is common in the threading of cold-forged steel. In this work, the first objective is to measure wear on various types of roll taps manufactured to tapping holes in microalloyed HR45 steel. Different geometries and levels of wear are tested and measured. Taking their geometry as the critical factor, the types of forming tap with the least wear and the best performance are identified. Abrasive wear was observed on the forming lobes. A higher number of lobes in the chamber zone and around the nominal diameter meant a more uniform load distribution and a more gradual forming process. A second objective is to identify the most accurate data-mining technique for the prediction of form-tap wear. Different data-mining techniques are tested to select the most accurate one: from standard versions such as Multilayer Perceptrons, Support Vector Machines and Regression Trees to the most recent ones such as Rotation Forest ensembles and Iterated Bagging ensembles. The best results were obtained with ensembles of Rotation Forest with unpruned Regression Trees as base regressors that reduced the RMS error of the best-tested baseline technique for the lower length output by 33%, and Additive Regression with unpruned M5P as base regressors that reduced the RMS errors of the linear fit for the upper and total lengths by 25% and 39%, respectively. However, the lower length was statistically more difficult to model in Additive Regression than in Rotation Forest. Rotation Forest with unpruned Regression Trees as base regressors therefore appeared to be the most suitable regressor for the modeling of this industrial problem.

  5. Threaded-Field-Lines Model for the Low Solar Corona Powered by the Alfven Wave Turbulence

    CERN Document Server

    Sokolov, Igor V; Manchester, Ward B; Ozturk, Doga Can Su; Szente, Judit; Taktakishvili, Aleksandre; Tóth, Gabor; Jin, Meng; Gombosi, Tamas I

    2016-01-01

    We present an updated global model of the solar corona, including the transition region. We simulate the realistic tree-dimensional (3D) magnetic field using the data from the photospheric magnetic field measurements and assume the magnetohydrodynamic (MHD) Alfv\\'en wave turbulence and its non-linear dissipation to be the only source for heating the coronal plasma and driving the solar wind. In closed field regions the dissipation efficiency in a balanced turbulence is enhanced. In the coronal holes we account for a reflection of the outward propagating waves, which is accompanied by generation of weaker counter-propagating waves. The non-linear cascade rate degrades in strongly imbalanced turbulence, thus resulting in colder coronal holes. The distinctive feature of the presented model is the description of the low corona as almost-steady-state low-beta plasma motion and heat flux transfer along the magnetic field lines. We trace the magnetic field lines through each grid point of the lower boundary of the g...

  6. Mobile Thread Task Manager

    Science.gov (United States)

    Clement, Bradley J.; Estlin, Tara A.; Bornstein, Benjamin J.

    2013-01-01

    The Mobile Thread Task Manager (MTTM) is being applied to parallelizing existing flight software to understand the benefits and to develop new techniques and architectural concepts for adapting software to multicore architectures. It allocates and load-balances tasks for a group of threads that migrate across processors to improve cache performance. In order to balance-load across threads, the MTTM augments a basic map-reduce strategy to draw jobs from a global queue. In a multicore processor, memory may be "homed" to the cache of a specific processor and must be accessed from that processor. The MTTB architecture wraps access to data with thread management to move threads to the home processor for that data so that the computation follows the data in an attempt to avoid L2 cache misses. Cache homing is also handled by a memory manager that translates identifiers to processor IDs where the data will be homed (according to rules defined by the user). The user can also specify the number of threads and processors separately, which is important for tuning performance for different patterns of computation and memory access. MTTM efficiently processes tasks in parallel on a multiprocessor computer. It also provides an interface to make it easier to adapt existing software to a multiprocessor environment.

  7. Network Models for Cognitive Development and Intelligence

    National Research Council Canada - National Science Library

    Han L J VanDer; Kees-Jan Kan; Maarten Marsman; Claire E Stevenson

    2017-01-01

    ... (dimensionality of individual differences). The welcome integration of the two fields requires the construction of mechanistic models of cognition and cognitive development that explain key phenomena in individual differences research...

  8. Cognitive Modeling of Social Behaviors

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Damer. Bruce; Brodsky, Boris

    2004-01-01

    The driving theme of cognitive modeling for many decades has been that knowledge affects how and which goals are accomplished by an intelligent being (Newell 1991). But when one examines groups of people living and working together, one is forced to recognize that whose knowledge is called into play, at a particular time and location, directly affects what the group accomplishes. Indeed, constraints on participation, including roles, procedures, and norms, affect whether an individual is able to act at all (Lave & Wenger 1991; Jordan 1992; Scribner & Sachs 1991). To understand both individual cognition and collective activity, perhaps the greatest opportunity today is to integrate the cognitive modeling approach (which stresses how beliefs are formed and drive behavior) with social studies (which stress how relationships and informal practices drive behavior). The crucial insight is that norms are conceptualized in the individual &nd as ways of carrying out activities (Clancey 1997a, 2002b). This requires for the psychologist a shift from only modeling goals and tasks - why people do what they do - to modeling behavioral patterns-what people do-as they are engaged in purposeful activities. Instead of a model that exclusively deduces actions from goals, behaviors are also, if not primarily, driven by broader patterns of chronological and located activities (akin to scripts). This analysis is particular inspired by activity theory (Leont ev 1979). While acknowledging that knowledge (relating goals and operations) is fundamental for intelligent behavior, activity theory claims that a broader driver is the person s motives and conceptualization of activities. Such understanding of human interaction is normative (i.e., viewed with respect to social standards), affecting how knowledge is called into play and applied in practice. Put another way, how problems are discovered and framed, what methods are chosen, and indeed who even cares or has the authority to act, are all

  9. The cognitive life of mechanical molecular models.

    Science.gov (United States)

    Charbonneau, Mathieu

    2013-12-01

    The use of physical models of molecular structures as research tools has been central to the development of biochemistry and molecular biology. Intriguingly, it has received little attention from scholars of science. In this paper, I argue that these physical models are not mere three-dimensional representations but that they are in fact very special research tools: they are cognitive augmentations. Despite the fact that they are external props, these models serve as cognitive tools that augment and extend the modeler's cognitive capacities and performance in molecular modeling tasks. This cognitive enhancement is obtained because of the way the modeler interacts with these models, the models' materiality contributing to the solving of the molecule's structure. Furthermore, I argue that these material models and their component parts were designed, built and used specifically to serve as cognitive facilitators and cognitive augmentations.

  10. Silicon carbide sewing thread

    Science.gov (United States)

    Sawko, Paul M. (Inventor)

    1995-01-01

    Composite flexible multilayer insulation systems (MLI) were evaluated for thermal performance and compared with currently used fibrous silica (baseline) insulation system. The systems described are multilayer insulations consisting of alternating layers of metal foil and scrim ceramic cloth or vacuum metallized polymeric films quilted together using ceramic thread. A silicon carbide thread for use in the quilting and the method of making it are also described. These systems provide lightweight thermal insulation for a variety of uses, particularly on the surface of aerospace vehicles subject to very high temperatures during flight.

  11. On the utility of threads for data parallel programming

    Science.gov (United States)

    Fahringer, Thomas; Haines, Matthew; Mehrotra, Piyush

    1995-01-01

    Threads provide a useful programming model for asynchronous behavior because of their ability to encapsulate units of work that can then be scheduled for execution at runtime, based on the dynamic state of a system. Recently, the threaded model has been applied to the domain of data parallel scientific codes, and initial reports indicate that the threaded model can produce performance gains over non-threaded approaches, primarily through the use of overlapping useful computation with communication latency. However, overlapping computation with communication is possible without the benefit of threads if the communication system supports asynchronous primitives, and this comparison has not been made in previous papers. This paper provides a critical look at the utility of lightweight threads as applied to data parallel scientific programming.

  12. Dedicated memory structure holding data for detecting available worker thread(s) and informing available worker thread(s) of task(s) to execute

    Science.gov (United States)

    Chiu, George L.; Eichenberger, Alexandre E.; O'Brien, John K. P.

    2016-12-13

    The present disclosure relates generally to a dedicated memory structure (that is, hardware device) holding data for detecting available worker thread(s) and informing available worker thread(s) of task(s) to execute.

  13. Influence of thread construction on strength of ceramic sewing threads

    Science.gov (United States)

    Sawko, Paul M.; Tran, Huy Kim

    1987-01-01

    The effects of two thread construction variables, yarn twist and polymeric sizing, on break strength were obtained for a silica thread and two types of aluminoborosilicate (ABS) threads at temperatures ranging from 23 C to 1200 C. It was shown that increasing the degree of twist for the silica thread produced an optimum twist level until all the yarn finish was removed. The break strength of both ABS threads was inversely proportional to the degree of twist caused by increased filament breakage with increasing twist that was controlled by the gradual removal of the polymeric processing aids. At elevated temperatures, above 950 C, strength loss was observed for both ABS threads because of the presence of a glass phase that softens and causes fiber deformation. This was not observed for the silica thread at similar test temperatures because of the higher viscosity of the pure silica glass phase.

  14. Sensory processing, neurocognition, and social cognition in schizophrenia: Towards a cohesive cognitive model

    NARCIS (Netherlands)

    Jong, J.S. de; Gelder, B.B. de; Hodiamont, P.P.G.

    2013-01-01

    Schizophrenia research has identified deficits in neurocognition, social cognition, and sensory processing. Because a cohesive model of "disturbed cognitive machinery" is currently lacking, we built a conceptual model to integrate neurocognition, social cognition, and sensory processing. In a cross-

  15. Inner rehearsal modeling for cognitive robotics

    Science.gov (United States)

    Braun, Jerome J.; Bergen, Karianne; Dasey, Timothy J.

    2011-05-01

    This paper presents a biomimetic approach involving cognitive process modeling, for use in intelligent robot decisionmaking. The principle of inner rehearsal, a process believed to occur in human and animal cognition, involves internal rehearsing of actions prior to deciding on and executing an overt action, such as a motor action. The inner-rehearsal algorithmic approach we developed is posed and investigated in the context of a relatively complex cognitive task, an under-rubble search and rescue. The paper presents the approach developed, a synthetic environment which was also developed to enable its studies, and the results to date. The work reported here is part of a Cognitive Robotics effort in which we are currently engaged, focused on exploring techniques inspired by cognitive science and neuroscience insights, towards artificial cognition for robotics and autonomous systems.

  16. The place of modeling in cognitive science.

    Science.gov (United States)

    McClelland, James L

    2009-01-01

    I consider the role of cognitive modeling in cognitive science. Modeling, and the computers that enable it, are central to the field, but the role of modeling is often misunderstood. Models are not intended to capture fully the processes they attempt to elucidate. Rather, they are explorations of ideas about the nature of cognitive processes. In these explorations, simplification is essential-through simplification, the implications of the central ideas become more transparent. This is not to say that simplification has no downsides; it does, and these are discussed. I then consider several contemporary frameworks for cognitive modeling, stressing the idea that each framework is useful in its own particular ways. Increases in computer power (by a factor of about 4 million) since 1958 have enabled new modeling paradigms to emerge, but these also depend on new ways of thinking. Will new paradigms emerge again with the next 1,000-fold increase?

  17. Using cognitive modeling for requirements engineering in anesthesiology

    NARCIS (Netherlands)

    Pott, C; le Feber, J

    2005-01-01

    Cognitive modeling is a complexity reducing method to describe significant cognitive processes under a specified research focus. Here, a cognitive process model for decision making in anesthesiology is presented and applied in requirements engineering. Three decision making situations of

  18. Performance of an adjustable, threaded inertance tube

    Science.gov (United States)

    Zhou, W. J.; Pfotenhauer, J. M.; Nellis, G. F.; Liu, S. Y.

    2015-12-01

    The performance of the Stirling type pulse tube cryocooler depends strongly on the design of the inertance tube. The phase angle produced by the inertance tube is very sensitive to its diameter and length. Recent developments are reported here regarding an adjustable inertance device that can be adjusted in real time. The inertance passage is formed by the root of a concentric cylindrical threaded device. The depth of the threads installed on the outer screw varies. In this device, the outer screw can be rotated four and half turns. At the zero turn position the length of the passage is 1.74 m and the hydraulic diameter is 7 mm. By rotating the outer screw, the inner threaded rod engages with additional, larger depth threads. Therefore, at its upper limit of rotation, the inertance passage includes both the original 1.74 m length with 7mm hydraulic diameter plus an additional 1.86 m length with a 10 mm hydraulic diameter. A phase shift change of 24° has been experimentally measured by changing the position of outer screw while operating the device at a frequency of 60 Hz. This phase angle shift is less than the theoretically predicted value due to the presence of a relatively large leak through the thread clearance. Therefore, the distributed component model of the inertance tube was modified to account for the leak path causing the data to agree with the model. Further, the application of vacuum grease to the threads causes the performance of the device to improve substantially.

  19. Modeling cognitive dysfunction in neurofibromatosis-1.

    Science.gov (United States)

    Diggs-Andrews, Kelly A; Gutmann, David H

    2013-04-01

    Cognitive dysfunction, including significant impairments in learning, behavior, and attention, is found in over 10% of children in the general population. However, in the common inherited cancer predisposition syndrome, neurofibromatosis type 1 (NF1), the prevalence of these cognitive deficits approaches 70%. As a monogenic disorder, NF1 provides a unique genetic tool to identify and dissect mechanistically the molecular and cellular bases underlying cognitive dysfunction. In this review, we discuss Nf1 fly and mouse systems that mimic many of the cognitive abnormalities seen in children with NF1. Further, we describe discoveries from these models that have uncovered defects in the regulation of Ras activity, cAMP generation, and dopamine homeostasis as key mechanisms important for cognitive dysfunction in children with NF1.

  20. Cognitive Virtualization: Combining Cognitive Models and Virtual Environments

    Energy Technology Data Exchange (ETDEWEB)

    Tuan Q. Tran; David I. Gertman; Donald D. Dudenhoeffer; Ronald L. Boring; Alan R. Mecham

    2007-08-01

    3D manikins are often used in visualizations to model human activity in complex settings. Manikins assist in developing understanding of human actions, movements and routines in a variety of different environments representing new conceptual designs. One such environment is a nuclear power plant control room, here they have the potential to be used to simulate more precise ergonomic assessments of human work stations. Next generation control rooms will pose numerous challenges for system designers. The manikin modeling approach by itself, however, may be insufficient for dealing with the desired technical advancements and challenges of next generation automated systems. Uncertainty regarding effective staffing levels; and the potential for negative human performance consequences in the presence of advanced automated systems (e.g., reduced vigilance, poor situation awareness, mistrust or blind faith in automation, higher information load and increased complexity) call for further research. Baseline assessment of novel control room equipment(s) and configurations needs to be conducted. These design uncertainties can be reduced through complementary analysis that merges ergonomic manikin models with models of higher cognitive functions, such as attention, memory, decision-making, and problem-solving. This paper will discuss recent advancements in merging a theoretical-driven cognitive modeling framework within a 3D visualization modeling tool to evaluate of next generation control room human factors and ergonomic assessment. Though this discussion primary focuses on control room design, the application for such a merger between 3D visualization and cognitive modeling can be extended to various areas of focus such as training and scenario planning.

  1. Perspectives on modeling in cognitive science.

    Science.gov (United States)

    Shiffrin, Richard M

    2010-10-01

    This commentary gives a personal perspective on modeling and modeling developments in cognitive science, starting in the 1950s, but focusing on the author's personal views of modeling since training in the late 1960s, and particularly focusing on advances since the official founding of the Cognitive Science Society. The range and variety of modeling approaches in use today are remarkable, and for many, bewildering. Yet to come to anything approaching adequate insights into the infinitely complex fields of mind, brain, and intelligent systems, an extremely wide array of modeling approaches is vital and necessary.

  2. Time models and cognitive processes: a review

    Directory of Open Access Journals (Sweden)

    Michail eManiadakis

    2014-02-01

    Full Text Available The sense of time is an essential capacity of humans, with a major role in many of the cognitive processes expressed in our daily lifes. So far, in cognitive science and robotics research, mental capacities have been investigated in a theoretical and modelling framework that largely neglects the flow of time. Only recently there has been a small but constantly increasing interest in the temporal aspects of cognition, integrating time into a range of different models of perceptuo-motor capacities. The current paper aims to review existing works in the field and suggest directions for fruitful future work. This is particularly important for the newly developed field of artificial temporal cognition that is expected to significantly contribute in the development of sophisticated artificial agents seamlessly integrated into human societies.

  3. Denotational semantics for thread algebra

    NARCIS (Netherlands)

    Vu, T.D.

    2008-01-01

    This paper gives a denotational semantics for thread algebra (TA), an algebraic framework for the description and analysis of recent programming languages such as C# and Java [J.A. Bergstra, C.A. Middelburg, Thread algebra for strategic interleaving, Formal Aspects of Computing, in press.

  4. Hierarchical Item Response Models for Cognitive Diagnosis

    Science.gov (United States)

    Hansen, Mark Patrick

    2013-01-01

    Cognitive diagnosis models (see, e.g., Rupp, Templin, & Henson, 2010) have received increasing attention within educational and psychological measurement. The popularity of these models may be largely due to their perceived ability to provide useful information concerning both examinees (classifying them according to their attribute profiles)…

  5. Corvid Caching : Insights From a Cognitive Model

    NARCIS (Netherlands)

    van der Vaart, Elske; Verbrugge, Rineke; Hemelrijk, Charlotte K.

    2011-01-01

    Caching and recovery of food by corvids is well-studied, but some ambiguous results remain. To help clarify these, we built a computational cognitive model. It is inspired by similar models built for humans, and it assumes that memory strength depends on frequency and recency of use. We compared our

  6. [Cognitive neuroscience of aging: explanatory models].

    Science.gov (United States)

    Grandi, Fabrissio; Tirapu Ustárroz, Javier

    2017-05-12

    The aim of the cognitive neuroscience of aging is the study of brain activity and the cognitive processes associated with age. In order to understand the dynamics of neurocognitive activity in older people, the present review highlights four explanatory models. The first one (HAROLD) highlights brain bilaterality, mainly in the pre-frontal cortex. The second paradigm (PASA) places special emphasis on neuronal polarisation (anterior-posterior). The third model (CRUNCH) relates the manifest activity of the brain to the level of complexity of the task. The last one (ELSA) emphasises the spatial and temporal distribution of brain activity in the different phases of recovery. Although different in their content, the four explanatory models are perfectly compatible with the findings reported by neuroimaging techniques, suggesting the use of compensation strategies and cognitive reserve for interventions that may help to optimise the performance of older people. Copyright © 2017 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Comprehensive Security Framework for Global Threads Analysis

    CERN Document Server

    Saraydaryan, Jacques; Ubeda, Stephane

    2009-01-01

    Cyber criminality activities are changing and becoming more and more professional. With the growth of financial flows through the Internet and the Information System (IS), new kinds of thread arise involving complex scenarios spread within multiple IS components. The IS information modeling and Behavioral Analysis are becoming new solutions to normalize the IS information and counter these new threads. This paper presents a framework which details the principal and necessary steps for monitoring an IS. We present the architecture of the framework, i.e. an ontology of activities carried out within an IS to model security information and User Behavioral analysis. The results of the performed experiments on real data show that the modeling is effective to reduce the amount of events by 91%. The User Behavioral Analysis on uniform modeled data is also effective, detecting more than 80% of legitimate actions of attack scenarios.

  8. A Cognitive Model of College Mathematics Placement

    Science.gov (United States)

    1989-08-01

    study focused on the precalculus -- calculus placement decision. The Cognitive model uses novel, or analysis level, placement test items in an attempt to...relative to the requirements of a precalculus course. Placement test scores may be partitioned to give analysis and non-analysis subtest scores which can...67 5.1.1 1989 Intercorrelations ....................................................................... 67 5.1.2 1989 Precalculus -Calculus

  9. Bayesian modeling of flexible cognitive control

    Science.gov (United States)

    Jiang, Jiefeng; Heller, Katherine; Egner, Tobias

    2014-01-01

    Cognitive control” describes endogenous guidance of behavior in situations where routine stimulus-response associations are suboptimal for achieving a desired goal. The computational and neural mechanisms underlying this capacity remain poorly understood. We examine recent advances stemming from the application of a Bayesian learner perspective that provides optimal prediction for control processes. In reviewing the application of Bayesian models to cognitive control, we note that an important limitation in current models is a lack of a plausible mechanism for the flexible adjustment of control over conflict levels changing at varying temporal scales. We then show that flexible cognitive control can be achieved by a Bayesian model with a volatility-driven learning mechanism that modulates dynamically the relative dependence on recent and remote experiences in its prediction of future control demand. We conclude that the emergent Bayesian perspective on computational mechanisms of cognitive control holds considerable promise, especially if future studies can identify neural substrates of the variables encoded by these models, and determine the nature (Bayesian or otherwise) of their neural implementation. PMID:24929218

  10. 3D gender recognition using cognitive modeling

    DEFF Research Database (Denmark)

    Fagertun, Jens; Andersen, Tobias; Hansen, Thomas

    2013-01-01

    We use 3D scans of human faces and cognitive modeling to estimate the “gender strength”. The “gender strength” is a continuous class variable of the gender, superseding the traditional binary class labeling. To visualize some of the visual trends humans use when performing gender classification, ...

  11. Cognitive modelling of human temporal reasoning

    NARCIS (Netherlands)

    ter Meulen, AGB

    2003-01-01

    Modelling human reasoning characterizes the fundamental human cognitive capacity to describe our past experience and use it to form expectations as well as plan and direct our future actions. Natural language semantics analyzes dynamic forms of reasoning in which the real-time order determines the

  12. Bayesian modeling of flexible cognitive control.

    Science.gov (United States)

    Jiang, Jiefeng; Heller, Katherine; Egner, Tobias

    2014-10-01

    "Cognitive control" describes endogenous guidance of behavior in situations where routine stimulus-response associations are suboptimal for achieving a desired goal. The computational and neural mechanisms underlying this capacity remain poorly understood. We examine recent advances stemming from the application of a Bayesian learner perspective that provides optimal prediction for control processes. In reviewing the application of Bayesian models to cognitive control, we note that an important limitation in current models is a lack of a plausible mechanism for the flexible adjustment of control over conflict levels changing at varying temporal scales. We then show that flexible cognitive control can be achieved by a Bayesian model with a volatility-driven learning mechanism that modulates dynamically the relative dependence on recent and remote experiences in its prediction of future control demand. We conclude that the emergent Bayesian perspective on computational mechanisms of cognitive control holds considerable promise, especially if future studies can identify neural substrates of the variables encoded by these models, and determine the nature (Bayesian or otherwise) of their neural implementation.

  13. An Attributional (Cognitive) Model of Motivation.

    Science.gov (United States)

    Weiner, Bernard; And Others

    A cognitive model of motivation is proposed which postulates four components as the determinants of the actual and anticipated outcome of an achievement-related event. The four determinants are ability, effort, task difficulty, and luck. These factors may be classified as either internal or external sources of control, and as either stable or…

  14. Zero Overhead Java Thread Migration

    OpenAIRE

    Bouchenak, Sara; Hagimont, Daniel

    2002-01-01

    The wide diffusion of Java is partly due to its mechanisms for mobile computing. Java provides most of the functions required to implement mobile applications, essentially code mobility (i.e., dynamic class loading) and data mobility (i.e., object serialization). However, Java does not provide any mechanism for the mobility of the computation (i.e., threads migration). Several projects have addressed the issue of Java thread migration- , e.g.,Sumatra, Wasp, JavaGo, Brakes, CIA. Most of these ...

  15. Genetic algorithms for protein threading.

    Science.gov (United States)

    Yadgari, J; Amir, A; Unger, R

    1998-01-01

    Despite many years of efforts, a direct prediction of protein structure from sequence is still not possible. As a result, in the last few years researchers have started to address the "inverse folding problem": Identifying and aligning a sequence to the fold with which it is most compatible, a process known as "threading". In two meetings in which protein folding predictions were objectively evaluated, it became clear that threading as a concept promises a real breakthrough, but that much improvement is still needed in the technique itself. Threading is a NP-hard problem, and thus no general polynomial solution can be expected. Still a practical approach with demonstrated ability to find optimal solutions in many cases, and acceptable solutions in other cases, is needed. We applied the technique of Genetic Algorithms in order to significantly improve the ability of threading algorithms to find the optimal alignment of a sequence to a structure, i.e. the alignment with the minimum free energy. A major progress reported here is the design of a representation of the threading alignment as a string of fixed length. With this representation validation of alignments and genetic operators are effectively implemented. Appropriate data structure and parameters have been selected. It is shown that Genetic Algorithm threading is effective and is able to find the optimal alignment in a few test cases. Furthermore, the described algorithm is shown to perform well even without pre-definition of core elements. Existing threading methods are dependent on such constraints to make their calculations feasible. But the concept of core elements is inherently arbitrary and should be avoided if possible. While a rigorous proof is hard to submit yet an, we present indications that indeed Genetic Algorithm threading is capable of finding consistently good solutions of full alignments in search spaces of size up to 10(70).

  16. Application of Adaptive Threading Technique to Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    DING Jing-guo; HU Xian-lei; JIAO Jing-min; SHE Guang-fu; LIU Xiang-hua

    2008-01-01

    Thickness deviation of hot strip rolling needs to be strictly controlled in the computer system.An adaptive threading technique was researched,in which the measured data from threaded stands were used to predict thickness and material hardness errors,to modify the setup for the remaining unthreaded stands.After the adaptive threading model was used online on the hot strip mill of the Panzhihua Iron and Steel Group Co Ltd,the thickness deviation was decreased obviously.The hit rate of thickness control of different steel grades increases.

  17. Schizophrenia: an integrated sociodevelopmental-cognitive model.

    Science.gov (United States)

    Howes, Oliver D; Murray, Robin M

    2014-05-10

    Schizophrenia remains a major burden on patients and society. The dopamine hypothesis attempts to explain the pathogenic mechanisms of the disorder, and the neurodevelopmental hypothesis the origins. In the past 10 years an alternative, the cognitive model, has gained popularity. However, the first two theories have not been satisfactorily integrated, and the most influential iteration of the cognitive model makes no mention of dopamine, neurodevelopment, or indeed the brain. In this Review we show that developmental alterations secondary to variant genes, early hazards to the brain, and childhood adversity sensitise the dopamine system, and result in excessive presynaptic dopamine synthesis and release. Social adversity biases the cognitive schema that the individual uses to interpret experiences towards paranoid interpretations. Subsequent stress results in dysregulated dopamine release, causing the misattribution of salience to stimuli, which are then misinterpreted by the biased cognitive processes. The resulting paranoia and hallucinations in turn cause further stress, and eventually repeated dopamine dysregulation hardwires the psychotic beliefs. Finally, we consider the implications of this model for understanding and treatment of schizophrenia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Tear Production Rate in a Mouse Model of Dry Eye According to the Phenol Red Thread and Endodontic Absorbent Paper Point Tear Tests.

    Science.gov (United States)

    Kilic, Servet; Kulualp, Kadri

    2016-01-01

    This study compared the endodontic absorbent paper point test (EAPTT) and the phenol red thread test (PRTT) for the assessment of tear production rate in a mouse model of dry eye. Fourteen BALB/c breed female mice were allocated into experimental and control groups of equal number. For 6 wk, the experimental group was kept in dry-eye cabinets, whereas the control group was kept in normal cages under ambient conditions. In both groups, the tear production rate was measured by using EAPTT and PRTT before the study, at study baseline, and at weeks 2, 4, and 6. Tear production at weeks 2, 4, and 6 differed significantly between groups and tests. Evaluating the groups independently in terms of the test technique revealed significant differences in tear production rate between the 2 groups at the same measurement times. Due to their persistent exposure to evaporative stress factors, the tear production rate of the mice in the dry-eye cabinet was consistently lower than that of controls. Unlike PRTT, EAPTT can be readily applied to the small globes of laboratory animals without the need for forceps, thus saving time and effort. In addition, EAPTT was practical and imposed no undue stress on the mice, due to the test material's firmer structure. Therefore, compared with PRTT, EAPTT is safer and more reliable for the diagnosis of dry-eye syndrome in mice.

  19. Assessing Fit of Cognitive Diagnostic Models: A Case Study

    Science.gov (United States)

    Sinharay, Sandip; Almond, Russell G.

    2007-01-01

    A cognitive diagnostic model uses information from educational experts to describe the relationships between item performances and posited proficiencies. When the cognitive relationships can be described using a fully Bayesian model, Bayesian model checking procedures become available. Checking models tied to cognitive theory of the domains…

  20. Constant time worker thread allocation via configuration caching

    Science.gov (United States)

    Eichenberger, Alexandre E; O'Brien, John K. P.

    2014-11-04

    Mechanisms are provided for allocating threads for execution of a parallel region of code. A request for allocation of worker threads to execute the parallel region of code is received from a master thread. Cached thread allocation information identifying prior thread allocations that have been performed for the master thread are accessed. Worker threads are allocated to the master thread based on the cached thread allocation information. The parallel region of code is executed using the allocated worker threads.

  1. Social Cognition in Children: A Model for Intervention

    Science.gov (United States)

    Enright, Robert D.

    1976-01-01

    An attempt to formulate a model of social cognition which will describe what may be involved in making social cognitive inferences in children. Techniques for intervention are then derived from the model. (Author/NG)

  2. Optimization of bolt thread stress concentrations

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    Designs of threaded fasteners are controlled by different standards, and the number of different thread definitions is large. The most commonly used thread is probably the metric ISO thread, and this design is therefore used in the present paper. Thread root design controls the stress concentrati...... are found in the optimized designs leading to the proposal of a new standard. The reductions in the stress are achieved by rather simple changes made to the cutting tool....

  3. Evaluation of Model Fit in Cognitive Diagnosis Models

    Science.gov (United States)

    Hu, Jinxiang; Miller, M. David; Huggins-Manley, Anne Corinne; Chen, Yi-Hsin

    2016-01-01

    Cognitive diagnosis models (CDMs) estimate student ability profiles using latent attributes. Model fit to the data needs to be ascertained in order to determine whether inferences from CDMs are valid. This study investigated the usefulness of some popular model fit statistics to detect CDM fit including relative fit indices (AIC, BIC, and CAIC),…

  4. Formation and evolution of a multi-threaded prominence

    CERN Document Server

    Luna, M; DeVore, C R

    2012-01-01

    We investigate the process of formation and subsequent evolution of prominence plasma in a filament channel and its overlying arcade. We construct a three-dimensional time-dependent model of an intermediate quiescent prominence. We combine the magnetic field structure with one-dimensional independent simulations of many flux tubes, of a three-dimensional sheared double arcade, in which the thermal nonequilibrium process governs the plasma evolution. We have found that the condensations in the corona can be divided into two populations: threads and blobs. Threads are massive condensations that linger in the field line dips. Blobs are ubiquitous small condensations that are produced throughout the filament and overlying arcade magnetic structure, and rapidly fall to the chromosphere. The threads are the principal contributors to the total mass. The total prominence mass is in agreement with observations, assuming a reasonable filling factor. The motion of the threads is basically horizontal, while blobs move in...

  5. Quantum-like Modeling of Cognition

    Directory of Open Access Journals (Sweden)

    Andrei eKhrennikov

    2015-09-01

    Full Text Available This paper begins with a historical review of the mutual influence of physics and psychology, from Freud's invention of psychic energy inspired by von Boltzmann' thermodynamics to the enrichment quantum physics gained from the side of psychology by the notion of complementarity (the invention of Niels Bohr who was inspired by William James, besides we consider the resonance of the correspondence between Wolfgang Pauli and Carl Jung in both physics and psychology. Then we turn to the problem of development of mathematical models for laws of thought starting with Boolean logic and progressing towards foundations of classical probability theory. Interestingly, the laws of classical logic and probability are routinely violated not only by quantum statistical phenomena but by cognitive phenomena as well. This is yet another common feature between quantum physics and psychology.In particular, cognitive data can exhibit a kind of the probabilistic interference effect. This similarity with quantum physics convinced a multi-disciplinary group of scientists (physicists, psychologists, economists, sociologists to apply the mathematical apparatus of quantum mechanics to modeling of cognition. We illustrate this activity by considering a few concrete phenomena: the order and disjunction effects, recognition of ambiguous figures, categorization-decision making.In Appendix 1 we briefly present essentials of theory of contextual probability and a method of representations of contextual probabilities by complex probability amplitudes(solution of the ``inverse Born's problem'' based on a quantum-like representation algorithm (QLRA.

  6. Quantum-like Modeling of Cognition

    Science.gov (United States)

    Khrennikov, Andrei

    2015-09-01

    This paper begins with a historical review of the mutual influence of physics and psychology, from Freud's invention of psychic energy inspired by von Boltzmann' thermodynamics to the enrichment quantum physics gained from the side of psychology by the notion of complementarity (the invention of Niels Bohr who was inspired by William James), besides we consider the resonance of the correspondence between Wolfgang Pauli and Carl Jung in both physics and psychology. Then we turn to the problem of development of mathematical models for laws of thought starting with Boolean logic and progressing towards foundations of classical probability theory. Interestingly, the laws of classical logic and probability are routinely violated not only by quantum statistical phenomena but by cognitive phenomena as well. This is yet another common feature between quantum physics and psychology. In particular, cognitive data can exhibit a kind of the probabilistic interference effect. This similarity with quantum physics convinced a multi-disciplinary group of scientists (physicists, psychologists, economists, sociologists) to apply the mathematical apparatus of quantum mechanics to modeling of cognition. We illustrate this activity by considering a few concrete phenomena: the order and disjunction effects, recognition of ambiguous figures, categorization-decision making. In Appendix 1 we briefly present essentials of theory of contextual probability and a method of representations of contextual probabilities by complex probability amplitudes (solution of the ``inverse Born's problem'') based on a quantum-like representation algorithm (QLRA).

  7. An introduction to model-based cognitive neuroscience

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    Two recent innovations, the emergence of formal cognitive models and the addition of cognitive neuroscience data to the traditional behavioral data, have resulted in the birth of a new, interdisciplinary field of study: model-based cognitive neuroscience. Despite the increasing scientific interest

  8. Effects Of Twist On Ceramic Threads

    Science.gov (United States)

    Sawko, Paul M.; Tran, Huy Kim

    1989-01-01

    Report describes study of effects of yarn twist and other manufacturing parameters on strength of ceramic sewing threads. Three types of thread considered; silica, aluminoborosilicate (ABS) with 14 percent boria, and ABS with 2 percent boria. For silica thread, best twist found 300 turns per meter. Produced highest break strength at temperatures up to about 540 degree C. Overall strengths of both ABS threads higher than silica thread. Threads used to stitch insulating blankets for reusable spacraft; must resist high temperatures and high aerodynamic loads of reentry into atmosphere of Earth.

  9. User-oriented and cognitive models of information retrieval

    DEFF Research Database (Denmark)

    Järvelin, Kalervo; Ingwersen, Peter

    2010-01-01

    The domain of user-oriented and cognitive IR is first discussed, followed by a discussion on the dimensions and types of models one may build for the domain.  The focus of the present entry is on the models of user-oriented and cognitive IR, not on their empirical applications. Several models...... with different emphases on user-oriented and cognitive IR are presented - ranging from overall approaches and relevance models to procedural models, cognitive models, and task-based models. The present entry does not discuss empirical findings based on the models....

  10. User-oriented and cognitive models of information retrieval

    DEFF Research Database (Denmark)

    Järvelin, Kalervo; Ingwersen, Peter

    2010-01-01

    The domain of user-oriented and cognitive IR is first discussed, followed by a discussion on the dimensions and types of models one may build for the domain.  The focus of the present entry is on the models of user-oriented and cognitive IR, not on their empirical applications. Several models...... with different emphases on user-oriented and cognitive IR are presented - ranging from overall approaches and relevance models to procedural models, cognitive models, and task-based models. The present entry does not discuss empirical findings based on the models....

  11. Exploration for Understanding in Cognitive Modeling

    Science.gov (United States)

    Gluck, Kevin; Stanley, Clayton; Moore, L.; Reitter, David; Halbrügge, Marc

    2010-12-01

    The cognitive modeling and artificial general intelligence research communities may reap greater scientific return on research investments - may achieve an improved understanding of architectures and models - if there is more emphasis on systematic sensitivity and necessity analyses during model development, evaluation, and comparison. We demonstrate this methodological prescription with two of the models submitted for the Dynamic Stocks and Flows (DSF) Model Comparison Challenge, exploring the complex interactions among architectural mechanisms, knowledge-level strategy variants, and task conditions. To cope with the computational demands of these analyses we use a predictive analytics approach similar to regression trees, combined with parallelization on high performance computing clusters, to enable large scale, simultaneous search and exploration.

  12. Compulsive buying: a cognitive-behavioural model.

    Science.gov (United States)

    Kellett, Stephen; Bolton, Jessica V

    2009-01-01

    Compulsive buying (CB) has only relatively recently become a topic of interest for researchers and clinicians alike. This hiatus means that (unlike other impulse control disorders) there is currently little theoretical guidance for clinicians attempting to intervene with CB clients and no established model for researchers to evaluate, distil and refine. The current paper summarizes and organizes the main extant identified factors in the CB literature into four distinct phases: (1) antecedents; (2) internal/external triggers; (3) the act of buying; and finally, (4) post-purchase. The relationships and interactions between the identified phases are then hypothesized, within the proposed cognitive-behavioural model. The model distinguishes the key cognitive, affective and behavioural factors within each phase and identifies how CB can become self-reinforcing over time. The over-arching treatment implication is that CB can be re-conceptualized as chronic and repetitive failure in self-regulation efforts, and that psychological interventions can accommodate this in attempting to facilitate change. A successful case example is provided of a 'co-dependent compulsive buyer' using the model, with psychometric evaluation of key aspects of CB and mental health at assessment, termination and 6-month follow-up. The research and clinical implications of the proposed model are discussed, alongside identified short-comings and the need for psychological services to respond appropriately to CB clients seeking help.

  13. Advantages and Disadvantages of Double Threaded Dental Implant Screws As Opposed to Single-Threaded: A Study from a Biomechanical Perspective by the Finite Element Method

    Science.gov (United States)

    Álvarez-Arenal, A.; de Cos Juez, F. J.; Lasheras, F. Sánchez; Quevedo, M. Mauvezin

    2009-08-01

    The purpose of the present article is to study the advantages from a biomechanical point of view of the use of a double-threaded dental implant over the more common single-threaded one. For this purpose a 3D model of a portion of the jaw was generated. In this model four different bone areas were distinguished (transition cortical, transition trabecular, bulk cortical and bulk trabecular). Not only was the portion of the jaw created with CAD software but also two different implants geometries, one with only one thread (single-threaded) and the other with two threads (double-threaded). The loading condition was defined as 150 N intrusive forces and 15 N lingual-labial forces acting on the implant. The results of the present study shown that from a macroscopic point of view, the choice of one or other of the dental implants does not make a significant difference in the general behaviour of the jaw. In spite of this and notwithstanding the effects of the transition bone-implant, the stress distribution achieved by the single-threaded dental implant is more uniform. This effect is better for the biomechanics of the jaw. The advantage presented by the double threaded implant is that due to its larger surface the osseointegration is better than in the single-threaded version.

  14. Fabrication and Characterisation of Flexible Coaxial Thin Thread Supercapacitors

    Directory of Open Access Journals (Sweden)

    Fulian Qiu

    2014-08-01

    Full Text Available Flexible coaxial thin thread supercapacitors were fabricated semi-automatically using a dip coating method. A typical coaxial thin thread supercapacitor of a length of 70 cm demonstrated a specific length capacitance of 0.3 mF cm-1 (11.2 mF cm-2 and 2.18 F cm-3 at 5 mV s-1, the device exhibited good electrochemical performance with a high volume energy density of 0.22 mWh cm-3 at a power density of 22 mW cm-3. Thread supercapacitors were assembled in series and parallel combinations, the accepted models for series and parallel circuit combinations were obeyed for two coaxial thread supercapacitors. The thread shows high flexibility and uniformity of specific length capacitance, one integrated with a commercial solar cell could be charged and power a LED. The process is simple, robust and easy to scale up to make unlimited length thread supercapacitors for numerous miniaturized and flexible electronic applications.

  15. Efficient Thread Labeling for Monitoring Programs with Nested Parallelism

    Science.gov (United States)

    Ha, Ok-Kyoon; Kim, Sun-Sook; Jun, Yong-Kee

    It is difficult and cumbersome to detect data races occurred in an execution of parallel programs. Any on-the-fly race detection techniques using Lamport's happened-before relation needs a thread labeling scheme for generating unique identifiers which maintain logical concurrency information for the parallel threads. NR labeling is an efficient thread labeling scheme for the fork-join program model with nested parallelism, because its efficiency depends only on the nesting depth for every fork and join operation. This paper presents an improved NR labeling, called e-NR labeling, in which every thread generates its label by inheriting the pointer to its ancestor list from the parent threads or by updating the pointer in a constant amount of time and space. This labeling is more efficient than the NR labeling, because its efficiency does not depend on the nesting depth for every fork and join operation. Some experiments were performed with OpenMP programs having nesting depths of three or four and maximum parallelisms varying from 10,000 to 1,000,000. The results show that e-NR is 5 times faster than NR labeling and 4.3 times faster than OS labeling in the average time for creating and maintaining the thread labels. In average space required for labeling, it is 3.5 times smaller than NR labeling and 3 times smaller than OS labeling.

  16. FR/HR Sewing Thread

    Science.gov (United States)

    2015-09-01

    method that prevents disclosure of contents or reconstruction of the document. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public...RESISTANT MATERIALS NYLON LOW COSTS TEAR STRENGTH RECYCLED MATERIALS HIGH PERFORMANCE FIBERS SEWING YARN TWIST SEWING...THREAD PHYSICAL PROPERTIES HEAT RESISTANT MATERIALS BLENDS TWIST(MOTION) FIRE RESISTANCE FR(FLAME RETARDANT) Nanosyntex 11306 Timber

  17. Modularizing and Specifying Protocols among Threads

    Directory of Open Access Journals (Sweden)

    Farhad Arbab

    2013-02-01

    Full Text Available We identify three problems with current techniques for implementing protocols among threads, which complicate and impair the scalability of multicore software development: implementing synchronization, implementing coordination, and modularizing protocols. To mend these deficiencies, we argue for the use of domain-specific languages (DSL based on existing models of concurrency. To demonstrate the feasibility of this proposal, we explain how to use the model of concurrency Reo as a high-level protocol DSL, which offers appropriate abstractions and a natural separation of protocols and computations. We describe a Reo-to-Java compiler and illustrate its use through examples.

  18. Evaluating the multi-threading countermeasure

    CSIR Research Space (South Africa)

    Frieslaar, Ibraheem

    2016-12-01

    Full Text Available This research investigates the resistance of the multi-threaded countermeasure to side channel analysis (SCA) attacks. The multi-threaded countermeasure is attacked using the Correlation Power Analysis (CPA) and template attacks. Additionally...

  19. Avian Models for Human Cognitive Neuroscience: A Proposal.

    Science.gov (United States)

    Clayton, Nicola S; Emery, Nathan J

    2015-06-17

    Research on avian cognitive neuroscience over the past two decades has revealed the avian brain to be a better model for understanding human cognition than previously thought, despite differences in the neuroarchitecture of avian and mammalian brains. The brain, behavior, and cognition of songbirds have provided an excellent model of human cognition in one domain, namely learning human language and the production of speech. There are other important behavioral candidates of avian cognition, however, notably the capacity of corvids to remember the past and plan for the future, as well as their ability to think about another's perspective, and physical reasoning. We review this work and assess the evidence that the corvid brain can support such a cognitive architecture. We propose potential applications of these behavioral paradigms for cognitive neuroscience, including recent work on single-cell recordings and neuroimaging in corvids. Finally, we discuss their impact on understanding human developmental cognition. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Some Instructional Implications from a Mathematical Model of Cognitive Development.

    Science.gov (United States)

    Mierkiewicz, Diane B.

    Cognitive development and various educational implications are discussed in terms of Donald Saari's model of the interaction of a learner and the enviroment and the constraints imposed by the inefficiency of the learner's cognitive system. Saari proposed a hierarchical system of cognitive structures such that the relationships between structures…

  1. Computational Grounded Cognition: A New Alliance between Grounded Cognition and Computational Modeling

    Directory of Open Access Journals (Sweden)

    Giovanni ePezzulo

    2013-01-01

    Full Text Available Grounded theories assume that there is no central module for cognition. According to this view, all cognitive phenomena, including those considered the province of amodal cognition such as reasoning, numeric and language processing, are ultimately grounded in (and emerge from a variety of bodily, affective, perceptual and motor processes. The development and expression of cognition is constrained by the embodiment of cognitive agents and various contextual factors (physical and social in which they are immersed. The grounded framework has received numerous empirical confirmations. Still, there are very few explicit computational models that implement grounding in sensory, motor and affective processes as intrinsic to cognition, and demonstrate that grounded theories can mechanistically implement higher cognitive abilities. We propose a new alliance between grounded cognition and computational modeling towards a novel multidisciplinary enterprise: Computational Grounded Cognition. We clarify the defining features of this novel approach and emphasize the importance of using the methodology of Cognitive Robotics, which permits simultaneous consideration of multiple aspects of grounding, embodiment, and situatedness, showing how they constrain the development and expression of cognition.

  2. Cyberpsychology: a human-interaction perspective based on cognitive modeling.

    Science.gov (United States)

    Emond, Bruno; West, Robert L

    2003-10-01

    This paper argues for the relevance of cognitive modeling and cognitive architectures to cyberpsychology. From a human-computer interaction point of view, cognitive modeling can have benefits both for theory and model building, and for the design and evaluation of sociotechnical systems usability. Cognitive modeling research applied to human-computer interaction has two complimentary objectives: (1) to develop theories and computational models of human interactive behavior with information and collaborative technologies, and (2) to use the computational models as building blocks for the design, implementation, and evaluation of interactive technologies. From the perspective of building theories and models, cognitive modeling offers the possibility to anchor cyberpsychology theories and models into cognitive architectures. From the perspective of the design and evaluation of socio-technical systems, cognitive models can provide the basis for simulated users, which can play an important role in usability testing. As an example of application of cognitive modeling to technology design, the paper presents a simulation of interactive behavior with five different adaptive menu algorithms: random, fixed, stacked, frequency based, and activation based. Results of the simulation indicate that fixed menu positions seem to offer the best support for classification like tasks such as filing e-mails. This research is part of the Human-Computer Interaction, and the Broadband Visual Communication research programs at the National Research Council of Canada, in collaboration with the Carleton Cognitive Modeling Lab at Carleton University.

  3. Extended spider cognition.

    Science.gov (United States)

    Japyassú, Hilton F; Laland, Kevin N

    2017-05-01

    There is a tension between the conception of cognition as a central nervous system (CNS) process and a view of cognition as extending towards the body or the contiguous environment. The centralised conception requires large or complex nervous systems to cope with complex environments. Conversely, the extended conception involves the outsourcing of information processing to the body or environment, thus making fewer demands on the processing power of the CNS. The evolution of extended cognition should be particularly favoured among small, generalist predators such as spiders, and here, we review the literature to evaluate the fit of empirical data with these contrasting models of cognition. Spiders do not seem to be cognitively limited, displaying a large diversity of learning processes, from habituation to contextual learning, including a sense of numerosity. To tease apart the central from the extended cognition, we apply the mutual manipulability criterion, testing the existence of reciprocal causal links between the putative elements of the system. We conclude that the web threads and configurations are integral parts of the cognitive systems. The extension of cognition to the web helps to explain some puzzling features of spider behaviour and seems to promote evolvability within the group, enhancing innovation through cognitive connectivity to variable habitat features. Graded changes in relative brain size could also be explained by outsourcing information processing to environmental features. More generally, niche-constructed structures emerge as prime candidates for extending animal cognition, generating the selective pressures that help to shape the evolving cognitive system.

  4. Multi-threaded Object Streaming

    CERN Document Server

    Pfeiffer, Andreas; Govi, Giacomo; Ojeda, Miguel; Sipos, Roland

    2015-01-01

    The CMS experiment at CERNs Large Hadron Collider in Geneva redesigned the code handling the conditions data during the last years, aiming to increase performance and enhance maintainability. The new design includes a move to serialise all payloads before storing them into the database, allowing the handling of the payloads in external tools independent of a given software release. In this talk we present the results of performance studies done using the serialisation package from the Boost suite as well as serialisation done with the ROOT (v5) tools. Furthermore, as the Boost tools allow parallel (de-)serialisation, we show the performance gains achieved with parallel threads when de-serialising a realistic set of conditions in CMS. Without specific optimisations an overall speed up of a factor of 3-4 was achieved using multi-threaded loading and de-serialisation of our conditions.

  5. Thread Algebra with Multi-Level Strategic Interleaving

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2004-01-01

    In a previous paper, we developed an algebraic theory of threads and multi-threads based on strategic interleaving. This theory includes a number of plausible interleaving strategies on thread vectors. The strategic interleaving of a thread vector constitutes a multi-thread. Several multi-threads ma

  6. Complex versus Complicated Models of Cognition

    NARCIS (Netherlands)

    den Hartigh, Ruud; Cox, Ralf; van Geert, Paul; Magnani, Lorenzo; Bertolotti, Tommaso

    2016-01-01

    As humans, we continuously adapt our behavior to changes in our environment, and our cognitive abilities continuously develop over time. A major question for scientists has been to discover the (cognitive) mechanism that underlies the control of human behavior in real-time, as well as cognitive deve

  7. Coronal heating in multiple magnetic threads

    CERN Document Server

    Tam, K V; Browning, P K; Cargill, P J

    2015-01-01

    Context. Heating the solar corona to several million degrees requires the conversion of magnetic energy into thermal energy. In this paper, we investigate whether an unstable magnetic thread within a coronal loop can destabilise a neighbouring magnetic thread. Aims. By running a series of simulations, we aim to understand under what conditions the destabilisation of a single magnetic thread can also trigger a release of energy in a nearby thread. Methods. The 3D magnetohydrodynamics code, Lare3d, is used to simulate the temporal evolution of coronal magnetic fields during a kink instability and the subsequent relaxation process. We assume that a coronal magnetic loop consists of non-potential magnetic threads that are initially in an equilibrium state. Results. The non-linear kink instability in one magnetic thread forms a helical current sheet and initiates magnetic reconnection. The current sheet fragments, and magnetic energy is released throughout that thread. We find that, under certain conditions, this ...

  8. Cognitive-Operative Model of Intelligent Learning Systems Behavior

    Science.gov (United States)

    Laureano-Cruces, Ana Lilia; Ramirez-Rodriguez, Javier; Mora-Torres, Martha; de Arriaga, Fernando; Escarela-Perez, Rafael

    2010-01-01

    In this paper behavior during the teaching-learning process is modeled by means of a fuzzy cognitive map. The elements used to model such behavior are part of a generic didactic model, which emphasizes the use of cognitive and operative strategies as part of the student-tutor interaction. Examples of possible initial scenarios for the…

  9. Cognitive-Operative Model of Intelligent Learning Systems Behavior

    Science.gov (United States)

    Laureano-Cruces, Ana Lilia; Ramirez-Rodriguez, Javier; Mora-Torres, Martha; de Arriaga, Fernando; Escarela-Perez, Rafael

    2010-01-01

    In this paper behavior during the teaching-learning process is modeled by means of a fuzzy cognitive map. The elements used to model such behavior are part of a generic didactic model, which emphasizes the use of cognitive and operative strategies as part of the student-tutor interaction. Examples of possible initial scenarios for the…

  10. An introduction to good practices in cognitive modeling

    NARCIS (Netherlands)

    A. Heathcote; S.D. Brown; E.-J. Wagenmakers

    2015-01-01

    Cognitive modeling can provide important insights into the underlying causes of behavior, but the validity of those insights rests on careful model development and checking. We provide guidelines on five important aspects of the practice of cognitive modeling: parameter recovery, testing selective i

  11. [Face rejuvenation with tensor threads].

    Science.gov (United States)

    Cornette de Saint Cyr, B; Benouaiche, L

    2017-08-25

    The last decades has seen new priorities in treatment of a flabby, ageing face towards minimally invasive aesthetic surgery, to be accompanied and followed by the requirements to perform such interventions with the maximally reduced health hazards, with inconsiderable injury, without cuts and, respectively, to be followed by no resulting scars, as well as a short postoperative period. We propose a new reviewing presentation of the tensor threads. After having explained the technology of the threads, we will discuss the good patient indication, the criteria which determine the choice of the threads and methods for each type of patient. There are many techniques, which we will present. Then, we will discuss the results, unsatisfactory outcomes obtained and complications encountered, as well as how to improve the cosmetic outcomes to be obtained. To conclude, we will propose a strategy for the long-term treatment of the neck and the face, preventing surgical management of the aging process. Copyright © 2017. Published by Elsevier Masson SAS.

  12. Bit threads and holographic entanglement

    CERN Document Server

    Freedman, Michael

    2016-01-01

    The Ryu-Takayanagi (RT) formula relates the entanglement entropy of a region in a holographic theory to the area of a corresponding bulk minimal surface. Using the max flow-min cut principle, a theorem from network theory, we rewrite the RT formula in a way that does not make reference to the minimal surface. Instead, we invoke the notion of a "flow", defined as a divergenceless norm-bounded vector field, or equivalently a set of Planck-thickness "bit threads". The entanglement entropy of a boundary region is given by the maximum flux out of it of any flow, or equivalently the maximum number of bit threads that can emanate from it. The threads thus represent entanglement between points on the boundary, and naturally implement the holographic principle. As we explain, this new picture clarifies several conceptual puzzles surrounding the RT formula. We give flow-based proofs of strong subadditivity and related properties; unlike the ones based on minimal surfaces, these proofs correspond in a transparent manner...

  13. Bit Threads and Holographic Entanglement

    Science.gov (United States)

    Freedman, Michael; Headrick, Matthew

    2016-11-01

    The Ryu-Takayanagi (RT) formula relates the entanglement entropy of a region in a holographic theory to the area of a corresponding bulk minimal surface. Using the max flow-min cut principle, a theorem from network theory, we rewrite the RT formula in a way that does not make reference to the minimal surface. Instead, we invoke the notion of a "flow", defined as a divergenceless norm-bounded vector field, or equivalently a set of Planck-thickness "bit threads". The entanglement entropy of a boundary region is given by the maximum flux out of it of any flow, or equivalently the maximum number of bit threads that can emanate from it. The threads thus represent entanglement between points on the boundary, and naturally implement the holographic principle. As we explain, this new picture clarifies several conceptual puzzles surrounding the RT formula. We give flow-based proofs of strong subadditivity and related properties; unlike the ones based on minimal surfaces, these proofs correspond in a transparent manner to the properties' information-theoretic meanings. We also briefly discuss certain technical advantages that the flows offer over minimal surfaces. In a mathematical appendix, we review the max flow-min cut theorem on networks and on Riemannian manifolds, and prove in the network case that the set of max flows varies Lipshitz continuously in the network parameters.

  14. BioShell-Threading: versatile Monte Carlo package for protein 3D threading.

    Science.gov (United States)

    Gniewek, Pawel; Kolinski, Andrzej; Kloczkowski, Andrzej; Gront, Dominik

    2014-01-20

    The comparative modeling approach to protein structure prediction inherently relies on a template structure. Before building a model such a template protein has to be found and aligned with the query sequence. Any error made on this stage may dramatically affects the quality of result. There is a need, therefore, to develop accurate and sensitive alignment protocols. BioShell threading software is a versatile tool for aligning protein structures, protein sequences or sequence profiles and query sequences to a template structures. The software is also capable of sub-optimal alignment generation. It can be executed as an application from the UNIX command line, or as a set of Java classes called from a script or a Java application. The implemented Monte Carlo search engine greatly facilitates the development and benchmarking of new alignment scoring schemes even when the functions exhibit non-deterministic polynomial-time complexity. Numerical experiments indicate that the new threading application offers template detection abilities and provides much better alignments than other methods. The package along with documentation and examples is available at: http://bioshell.pl/threading3d.

  15. Models and theories of brain function in cognition within a framework of behavioral cognitive psychology.

    Science.gov (United States)

    Karakaş, Sirel; Başar, Erol

    2006-05-01

    The present article presents a nonexhaustive collection of contemporary models and theories on brain function and discusses these models and theories within a framework of explanatory formulations in behavioral cognitive psychology. Such a mission was accomplished by evaluating the cognitive implications in the explanatory formulations with respect to established laws/principles and models/theories of behavioral cognitive psychology. The article also points to problem areas of behavioral cognitive psychology for which the explanatory formulations have solutions to offer. The article shows that the cinematographic hypothesis, the new visual model, the synergetic model, and the theory of whole-brain-work emphasize various aspects of perception. The formulations on P300 theory emphasize attention and also working memory. The theory on cognits is a comprehensive account of memory. Characteristic to all of these explanatory formulations and also to that on the complexity and its evolution and that on neurocognitive networks is the emphasis on selective distribution, integration to the point of supersynergy, and dynamicity. Such a viewpoint was not only applied to the operations of the brain but also of cognition. With such a conceptualization, the explanatory formulations could account for cognitive processes other than the ones emphasized. A common aspect in a majority of the formulations is the utilization of the oscillatory activity as the valid activity of the brain. The article points out that a frontier in cognitive psychophysiology would be the study of the genetics of brain oscillations.

  16. Visual behaviour analysis and driver cognitive model

    Energy Technology Data Exchange (ETDEWEB)

    Baujon, J.; Basset, M.; Gissinger, G.L. [Mulhouse Univ., (France). MIPS/MIAM Lab.

    2001-07-01

    Recent studies on driver behaviour have shown that perception - mainly visual but also proprioceptive perception - plays a key role in the ''driver-vehicle-road'' system and so considerably affects the driver's decision making. Within the framework of the behaviour analysis and studies low-cost system (BASIL), this paper presents a correlative, qualitative and quantitative study, comparing the information given by visual perception and by the trajectory followed. This information will help to obtain a cognitive model of the Rasmussen type according to different driver classes. Many experiments in real driving situations have been carried out for different driver classes and for a given trajectory profile, using a test vehicle and innovative, specially designed, real-time tools, such as the vision system or the positioning module. (orig.)

  17. A Review of Lightweight Thread Approaches for High Performance Computing

    Energy Technology Data Exchange (ETDEWEB)

    Castello, Adrian; Pena, Antonio J.; Seo, Sangmin; Mayo, Rafael; Balaji, Pavan; Quintana-Orti, Enrique S.

    2016-09-12

    High-level, directive-based solutions are becoming the programming models (PMs) of the multi/many-core architectures. Several solutions relying on operating system (OS) threads perfectly work with a moderate number of cores. However, exascale systems will spawn hundreds of thousands of threads in order to exploit their massive parallel architectures and thus conventional OS threads are too heavy for that purpose. Several lightweight thread (LWT) libraries have recently appeared offering lighter mechanisms to tackle massive concurrency. In order to examine the suitability of LWTs in high-level runtimes, we develop a set of microbenchmarks consisting of commonlyfound patterns in current parallel codes. Moreover, we study the semantics offered by some LWT libraries in order to expose the similarities between different LWT application programming interfaces. This study reveals that a reduced set of LWT functions can be sufficient to cover the common parallel code patterns and that those LWT libraries perform better than OS threads-based solutions in cases where task and nested parallelism are becoming more popular with new architectures.

  18. Modeling Cognitive Dysfunction in Neurofibromatosis-1

    OpenAIRE

    Diggs-Andrews, Kelly A.; David H Gutmann

    2013-01-01

    Cognitive dysfunction, including significant impairments in learning, behavior, and attention, is found in over 10% of children in the general population. However, in the common inherited cancer predisposition syndrome, Neurofibromatosis type 1 (NF1), the prevalence of these cognitive deficits approaches 70%. As a monogenic disorder, NF1 provides a unique genetic tool to identify and mechanistically dissect the molecular and cellular bases underlying cognitive dysfunction. In this review, we ...

  19. Developing a model of cognitive lockup for user interface engineering

    NARCIS (Netherlands)

    Mioch, T.; Looije, R.; Neerincx, M.A.

    2010-01-01

    This paper presents the development of a cognitive model of cognitive lockup: the tendency of humans to deal with disturbances sequentially, possibly overseeing crucial data from unattended resources so that serious task failures can appear—e.g., in a cockpit or control centre. The proposed model sh

  20. Developing a model of cognitive lockup for user interface engineering

    NARCIS (Netherlands)

    Mioch, T.; Looije, R.; Neerincx, M.A.

    2010-01-01

    This paper presents the development of a cognitive model of cognitive lockup: the tendency of humans to deal with disturbances sequentially, possibly overseeing crucial data from unattended resources so that serious task failures can appear—e.g., in a cockpit or control centre. The proposed model sh

  1. Framework of Pattern Recognition Model Based on the Cognitive Psychology

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template-based matching model,prototype-based matching model and feature-based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures.

  2. Cognitive Modeling of Video Game Player User Experience

    Science.gov (United States)

    Bohil, Corey J.; Biocca, Frank A.

    2010-01-01

    This paper argues for the use of cognitive modeling to gain a detailed and dynamic look into user experience during game play. Applying cognitive models to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive models are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single model - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making experiments, and has recently found application in real world scenarios. We examine possibilities for applying this model to game-play data.

  3. Protein Structure Prediction by Protein Threading

    Science.gov (United States)

    Xu, Ying; Liu, Zhijie; Cai, Liming; Xu, Dong

    The seminal work of Bowie, Lüthy, and Eisenberg (Bowie et al., 1991) on "the inverse protein folding problem" laid the foundation of protein structure prediction by protein threading. By using simple measures for fitness of different amino acid types to local structural environments defined in terms of solvent accessibility and protein secondary structure, the authors derived a simple and yet profoundly novel approach to assessing if a protein sequence fits well with a given protein structural fold. Their follow-up work (Elofsson et al., 1996; Fischer and Eisenberg, 1996; Fischer et al., 1996a,b) and the work by Jones, Taylor, and Thornton (Jones et al., 1992) on protein fold recognition led to the development of a new brand of powerful tools for protein structure prediction, which we now term "protein threading." These computational tools have played a key role in extending the utility of all the experimentally solved structures by X-ray crystallography and nuclear magnetic resonance (NMR), providing structural models and functional predictions for many of the proteins encoded in the hundreds of genomes that have been sequenced up to now.

  4. Toward a Multi-threaded Glish

    Science.gov (United States)

    Schiebel, D. R.

    Glish is the scripting language at the core of AIPS++ . Glish's asynchronous event handlers are, by nature, independent threads of execution, and AIPS++ developers have used these handlers to create many such threads without the concern typically required for thread creation and deletion. Starting AIPS++ creates over 3000 such threads. Having so many threads created in response to user scripts poses many challenges for the underlying scripting language implementation. The complexity involved warrants synchronization and mutual-exclusion constructs which are at at a higher level than those provided by pthreads (Kleiman et al. 1996) and similar libraries. Since Glish is implemented in C++, these constructs should be centered around objects rather than functions and critical regions. This paper discusses these issues, the initial work toward introducing multiple threads of execution into Glish, and possible tools for achieving object-oriented concurrency. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  5. Cognitive mechanisms of mindfulness: A test of current models.

    Science.gov (United States)

    Isbel, Ben; Mahar, Doug

    2015-12-15

    Existing models of mindfulness describe the self-regulation of attention as primary, leading to enhanced decentering and ability to access and override automatic cognitive processes. This study compared 23 experienced and 21 non-meditators on tests of mindfulness, attention, decentering, and ability to override automatic cognitive processes to test the cognitive mechanisms proposed to underlie mindfulness practice. Experienced meditators had significantly higher mindfulness and decentering than non-meditators. No significant difference between groups was found on measures of attention or ability to override automatic processes. These findings support the prediction that mindfulness leads to enhanced decentering, but do not support the cognitive mechanisms proposed to underlie such enhancement. Since mindfulness practice primarily involves internally directed attention, it may be the case that cognitive tests requiring externally directed attention and timed responses do not accurately assess mindfulness-induced cognitive changes. Implications for the models of mindfulness and future research are discussed.

  6. Cognitive engineering models in space systems

    Science.gov (United States)

    Mitchell, Christine M.

    1993-01-01

    NASA space systems, including mission operations on the ground and in space, are complex, dynamic, predominantly automated systems in which the human operator is a supervisory controller. Models of cognitive functions in complex systems are needed to describe human performance and form the theoretical basis of operator workstation design, including displays, controls, and decision aids. Currently, there several candidate modeling methodologies. They include the Rasmussen abstraction/aggregation hierarchy and decision ladder, the goal-means network, the problem behavior graph, and the operator function model. The research conducted under the sponsorship of this grant focuses on the extension of the theoretical structure of the operator function model and its application to NASA Johnson mission operations and space station applications. The initial portion of this research consists of two parts. The first is a series of technical exchanges between NASA Johnson and Georgia Tech researchers. The purpose is to identify candidate applications for the current operator function model; prospects include mission operations and the Data Management System Testbed. The second portion will address extensions of the operator function model to tailor it to the specific needs of Johnson applications. At this point, we have accomplished two things. During a series of conversations with JSC researchers, we have defined the technical goal of the research supported by this grant to be the structural definition of the operator function model and its computer implementation, OFMspert. Both the OFM and OFMspert have matured to the point that they require infrastructure to facilitate use by researchers not involved in the evolution of the tools. The second accomplishment this year was the identification of the Payload Deployment and Retrieval System (PDRS) as a candidate system for the case study. In conjunction with government and contractor personnel in the Human-Computer Interaction Lab

  7. Addressing contrasting cognitive models in scientific collaboration

    Science.gov (United States)

    Diviacco, P.

    2012-04-01

    If the social aspects of scientific communities and their internal dynamics is starting to be recognized and acknowledged in the everyday lives of scientists, it is rather difficult for them to find tools that could support their activities consistently with this perspective. Issues span from gathering researchers to mutual awareness, from information sharing to building meaning, with the last one being particularly critical in research fields as the geo-sciences, that deal with the reconstruction of unique, often non-reproducible, and contingent processes. Reasoning here is, in fact, mainly abductive, allowing multiple and concurrent explanations for the same phenomenon to coexist. Scientists bias one hypothesis over another not only on strictly logical but also on sociological motivations. Following a vision, scientists tend to evolve and isolate themselves from other scientists creating communities characterized by different cognitive models, so that after some time these become incompatible and scientists stop understanding each other. We address these problems as a communication issue so that the classic distinction into three levels (syntactic, semantic and pragmatic) can be used. At the syntactic level, we highlight non-technical obstacles that condition interoperability and data availability and transparency. At the semantic level, possible incompatibilities of cognitive models are particularly evident, so that using ontologies, cross-domain reconciliation should be applied. This is a very difficult task to perform since the projection of knowledge by scientists, in the designated community, is political and thus can create a lot of tension. The strategy we propose to overcome these issues pertains to pragmatics, in the sense that it is intended to acknowledge the cultural and personal factors each partner brings into the collaboration and is based on the idea that meaning should remain a flexible and contingent representation of possibly divergent views

  8. Effective verification of confidentiality for multi-threaded programs

    NARCIS (Netherlands)

    Ngo, Minh Tri; Stoelinga, Mariëlle; Huisman, Marieke

    2014-01-01

    This paper studies how confidentiality properties of multi-threaded programs can be verified efficiently by a combination of newly developed and existing model checking algorithms. In particular, we study the verification of scheduler-specific observational determinism (SSOD), a property that charac

  9. Development of cognitive model for navigating on the web

    NARCIS (Netherlands)

    Juvina, I.

    2006-01-01

    The objective of this thesis is to build a cognitive model of human performance in Web-assisted tasks. The research is driven by the following questions: What are the most important factors in determining success in Web-assisted tasks? What cognitive mechanisms are involved in these factors? What

  10. A Cognitive Developmental Model of Rigidity in Senescence.

    Science.gov (United States)

    Lapsley, Daniel K.; Enright, Robert D.

    1983-01-01

    The rigidity construct is reinterpreted in terms of the cognitive developmental approach. A review reveals both cognitive and developmental themes, with an emphasis on the structural and operational properties of rigidity. Notes weaknesses of previous approaches to rigidity and discusses implications and predictions from the proposed model.…

  11. Using of Structural Equation Modeling Techniques in Cognitive Levels Validation

    Directory of Open Access Journals (Sweden)

    Natalija Curkovic

    2012-10-01

    Full Text Available When constructing knowledge tests, cognitive level is usually one of the dimensions comprising the test specifications with each item assigned to measure a particular level. Recently used taxonomies of the cognitive levels most often represent some modification of the original Bloom’s taxonomy. There are many concerns in current literature about existence of predefined cognitive levels. The aim of this article is to investigate can structural equation modeling techniques confirm existence of different cognitive levels. For the purpose of the research, a Croatian final high-school Mathematics exam was used (N = 9626. Confirmatory factor analysis and structural regression modeling were used to test three different models. Structural equation modeling techniques did not support existence of different cognitive levels in this case. There is more than one possible explanation for that finding. Some other techniques that take into account nonlinear behaviour of the items as well as qualitative techniques might be more useful for the purpose of the cognitive levels validation. Furthermore, it seems that cognitive levels were not efficient descriptors of the items and so improvements are needed in describing the cognitive skills measured by items.

  12. Longitudinal mixed-effects models for latent cognitive function

    NARCIS (Netherlands)

    Hout, van den Ardo; Fox, Jean-Paul; Muniz-Terrera, Graciela

    2015-01-01

    A mixed-effects regression model with a bent-cable change-point predictor is formulated to describe potential decline of cognitive function over time in the older population. For the individual trajectories, cognitive function is considered to be a latent variable measured through an item response t

  13. Cognitive control in majority search: A computational modeling approach

    Directory of Open Access Journals (Sweden)

    Hongbin eWang

    2011-02-01

    Full Text Available Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided. The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain via the V4-ACC-LPFC-IPS loop for computing the majority function.

  14. Cognitive control in majority search: a computational modeling approach.

    Science.gov (United States)

    Wang, Hongbin; Liu, Xun; Fan, Jin

    2011-01-01

    Despite the importance of cognitive control in many cognitive tasks involving uncertainty, the computational mechanisms of cognitive control in response to uncertainty remain unclear. In this study, we develop biologically realistic neural network models to investigate the instantiation of cognitive control in a majority function task, where one determines the category to which the majority of items in a group belong. Two models are constructed, both of which include the same set of modules representing task-relevant brain functions and share the same model structure. However, with a critical change of a model parameter setting, the two models implement two different underlying algorithms: one for grouping search (where a subgroup of items are sampled and re-sampled until a congruent sample is found) and the other for self-terminating search (where the items are scanned and counted one-by-one until the majority is decided). The two algorithms hold distinct implications for the involvement of cognitive control. The modeling results show that while both models are able to perform the task, the grouping search model fit the human data better than the self-terminating search model. An examination of the dynamics underlying model performance reveals how cognitive control might be instantiated in the brain for computing the majority function.

  15. Deterministic Real-time Thread Scheduling

    CERN Document Server

    Yun, Heechul; Sha, Lui

    2011-01-01

    Race condition is a timing sensitive problem. A significant source of timing variation comes from nondeterministic hardware interactions such as cache misses. While data race detectors and model checkers can check races, the enormous state space of complex software makes it difficult to identify all of the races and those residual implementation errors still remain a big challenge. In this paper, we propose deterministic real-time scheduling methods to address scheduling nondeterminism in uniprocessor systems. The main idea is to use timing insensitive deterministic events, e.g, an instruction counter, in conjunction with a real-time clock to schedule threads. By introducing the concept of Worst Case Executable Instructions (WCEI), we guarantee both determinism and real-time performance.

  16. Performance Evaluation of Hyper Threading Technology ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    2015-12-01

    Dec 1, 2015 ... mode on various shared resources like L2 and L3 cache. Results using four .... unless a process requests a higher priority). Super- ... After that, Hyper-Threading was extended .... Hyper threading on the sixteen-stage pipeline Nehalem architecture with six ..... is that the mix of virtual sockets and virtual.

  17. Maurer Computers with Single-Thread Control

    NARCIS (Netherlands)

    Bergstra, J.A.; Middelburg, C.A.

    2005-01-01

    We present the development of a theory of stored threads and their execution. The work builds upon Maurer’s theory of computer instructions and the thread algebra of Bergstra et al. The theory being developed is primarily relevant to the design of new processor architectures. We also relate

  18. Hair-Thread Tourniquet Syndrome

    Directory of Open Access Journals (Sweden)

    Emre Gokcen

    2016-01-01

    Two month-old male infant was brought to the emergency service with the complaint of fever, uneasiness, and swelling on 4th-5th toes of right foot.  Apparent swelling, rubescence and increase in heat were seen and a constrictive band was observed to surround proximal phalanges of both toes in the physical examination of the patient (Figure 1.  A hair was found on the constrictive band surrounding both toes. The hair was removed by means of forceps. Oral antibiotic was administered to the patient. The patient was treated successfully by not letting a necrosis develop on the toes. It should be remembered that hair-thread tourniquet syndrome may be observed in the infant patients applying to the hospital with the complaints of unexplained fever and uneasiness. Figure 1: Appearance of the toes right after the hair was removed. Arrows show the constrictive band. 

  19. Interactions between causal models, theories, and social cognitive development.

    Science.gov (United States)

    Sobel, David M; Buchanan, David W; Butterfield, Jesse; Jenkins, Odest Chadwicke

    2010-01-01

    We propose a model of social cognitive development based not on a single modeling framework or the hypothesis that a single model accounts for children's developing social cognition. Rather, we advocate a Causal Model approach (cf. Waldmann, 1996), in which models of social cognitive development take the same position as theories of social cognitive development, in that they generate novel empirical hypotheses. We describe this approach and present three examples across various aspects of social cognitive development. Our first example focuses on children's understanding of pretense and involves only considering assumptions made by a computational framework. The second example focuses on children's learning from "testimony". It uses a modeling framework based on Markov random fields as a computational description of a set of empirical phenomena, and then tests a prediction of that description. The third example considers infants' generalization of action learned from imitation. Here, we use a modified version of the Rational Model of Categorization to explain children's inferences. Taken together, these examples suggest that research in social cognitive development can be assisted by considering how computational modeling can lead researchers towards testing novel hypotheses.

  20. The role of Rayleigh-Taylor instabilities in filament threads

    CERN Document Server

    Terradas, J; Ballester, J L

    2012-01-01

    Many solar filaments and prominences show short-lived horizontal threads lying parallel to the photosphere. In this work the possible link between Rayleigh-Taylor instabilities and thread lifetimes is investigated. This is done by calculating the eigenmodes of a thread modelled as a Cartesian slab under the presence of gravity. An analytical dispersion relation is derived using the incompressible assumption for the magnetohydrodynamic (MHD) perturbations. The system allows a mode that is always stable, independently of the value of the Alfv\\'en speed in the thread. The character of this mode varies from being localised at the upper interface of the slab when the magnetic field is weak, to having a global nature and resembling the transverse kink mode when the magnetic field is strong. On the contrary, the slab model permits another mode that is unstable and localised at the lower interface when the magnetic field is weak. The growth rates of this mode can be very short, of the order of minutes for typical thr...

  1. Development of a silicon carbide sewing thread

    Science.gov (United States)

    Sawko, Paul M.; Vasudev, Anand

    1989-01-01

    A silicon carbide (SiC) sewing thread has been designed which consists of a two-ply yarn in a 122 turns-per-meter-twist construction. Two processing aids in thread construction were evaluated. Prototype blankets were sewn using an SiC thread prepared either with polytetrafluoroethylene sizing or with an overwrap of rayon/dacron service yarn. The rayon/dacron-wrapped SiC thread was stronger, as shown by higher break-strength retention and less damage to the outer-mold-line fabric. This thread enables thermal protection system articles to be sewn or joined, or have perimeter close-out of assembled parts when using SiC fabric for high-temperature applications.

  2. Decision Making, Models of Mind, and the New Cognitive Science.

    Science.gov (United States)

    Evers, Colin W.

    1998-01-01

    Explores implications for understanding educational decision making from a cognitive science perspective. Examines three models of mind providing the methodological framework for decision-making studies. The "absent mind" embodies the behaviorist research tradition. The "functionalist mind" underwrites traditional cognitivism…

  3. Decision Making, Models of Mind, and the New Cognitive Science.

    Science.gov (United States)

    Evers, Colin W.

    1998-01-01

    Explores implications for understanding educational decision making from a cognitive science perspective. Examines three models of mind providing the methodological framework for decision-making studies. The "absent mind" embodies the behaviorist research tradition. The "functionalist mind" underwrites traditional cognitivism…

  4. Utilization-Based Modeling and Optimization for Cognitive Radio Networks

    Science.gov (United States)

    Liu, Yanbing; Huang, Jun; Liu, Zhangxiong

    The cognitive radio technique promises to manage and allocate the scarce radio spectrum in the highly varying and disparate modern environments. This paper considers a cognitive radio scenario composed of two queues for the primary (licensed) users and cognitive (unlicensed) users. According to the Markov process, the system state equations are derived and an optimization model for the system is proposed. Next, the system performance is evaluated by calculations which show the rationality of our system model. Furthermore, discussions among different parameters for the system are presented based on the experimental results.

  5. Relative and Absolute Fit Evaluation in Cognitive Diagnosis Modeling

    Science.gov (United States)

    Chen, Jinsong; de la Torre, Jimmy; Zhang, Zao

    2013-01-01

    As with any psychometric models, the validity of inferences from cognitive diagnosis models (CDMs) determines the extent to which these models can be useful. For inferences from CDMs to be valid, it is crucial that the fit of the model to the data is ascertained. Based on a simulation study, this study investigated the sensitivity of various fit…

  6. Delphi and Matlab Hybrid Programming Research Based on COM STA Threading Model%基于COM STA线程模型的Delphi与Matlab混合编程研究

    Institute of Scientific and Technical Information of China (English)

    李丰

    2013-01-01

    针对传统的基于COM的Matlab与Delphi混合编程技术,界面容易出现冻结现象,详细讨论了其出现的原因,提出了一种基于COM STA线程模型的改进的混合编程方法,并以一信号包络提取为例给出了改进方法的具体实现.%The traditional COM based on the Matlab and Delphi hybrid programming technology, the interface is easy to appear the freezing phenomenon, discussed in detail the reasons for its occur, proposed a method based on the COM STA threading model im?proved hybrid programming, and to a signal envelope extraction as an example and gives a improved method concrete implementa?tion.

  7. Complexity and information flow analysis for multi-threaded programs

    Science.gov (United States)

    Ngo, Tri Minh; Huisman, Marieke

    2017-01-01

    This paper studies the security of multi-threaded programs. We combine two methods, i.e., qualitative and quantitative security analysis, to check whether a multi-threaded program is secure or not. In this paper, besides reviewing classical analysis models, we present a novel model of quantitative analysis where the attacker is able to select the scheduling policy. This model does not follow the traditional information-theoretic channel setting. Our analysis first studies what extra information an attacker can get if he knows the scheduler's choices, and then integrates this information into the transition system modeling the program execution. Via a case study, we compare this approach with the traditional information-theoretic models, and show that this approach gives more intuitive-matching results.

  8. Complexity and information flow analysis for multi-threaded programs

    Science.gov (United States)

    Ngo, Tri Minh; Huisman, Marieke

    2017-07-01

    This paper studies the security of multi-threaded programs. We combine two methods, i.e., qualitative and quantitative security analysis, to check whether a multi-threaded program is secure or not. In this paper, besides reviewing classical analysis models, we present a novel model of quantitative analysis where the attacker is able to select the scheduling policy. This model does not follow the traditional information-theoretic channel setting. Our analysis first studies what extra information an attacker can get if he knows the scheduler's choices, and then integrates this information into the transition system modeling the program execution. Via a case study, we compare this approach with the traditional information-theoretic models, and show that this approach gives more intuitive-matching results.

  9. Cognitive model supported tactical training simulation

    NARCIS (Netherlands)

    Doesburg, W.A. van; Bosch, K. van den

    2005-01-01

    Simulation-based tactical training can be made more effective by using cognitive software agents to play key roles (e.g. team mate, adversaries, instructor). Due to the dynamic and complex nature of military tactics, it is hard to create agents that behave realistically and support the training lead

  10. Training tactical decision making using cognitive models

    NARCIS (Netherlands)

    Bosch, K. van den; Doesburg, W.A. van

    2005-01-01

    Simulation-based tactical training can be made more effective by using cognitive software agents to play key roles (e.g. team mates, adversaries). For successful use in training, agents should show tactically representative behavior that support trainees in achieving the learning objectives. For a t

  11. Dynamic Cognitive Tracing: Towards Unified Discovery of Student and Cognitive Models

    Science.gov (United States)

    Gonzalez-Brenes, Jose P.; Mostow, Jack

    2012-01-01

    This work describes a unified approach to two problems previously addressed separately in Intelligent Tutoring Systems: (i) Cognitive Modeling, which factorizes problem solving steps into the latent set of skills required to perform them; and (ii) Student Modeling, which infers students' learning by observing student performance. The practical…

  12. Manufacture of threads with variable pitch by using noncircular gears

    Science.gov (United States)

    Slătineanu, L.; Dodun, O.; Coteață, M.; Coman, I.; Nagîț, G.; Beșliu, I.

    2016-08-01

    There are mechanical equipments in which shafts threaded with variable pitch are included. Such a shaft could be met in the case of worm specific to the double enveloping worm gearing. Over the years, the researchers investigated some possibilities to geometrically define and manufacture the shaft zones characterized by a variable pitch. One of the methods able to facilitate the manufacture of threads with variable pitch is based on the use of noncircular gears in the threading kinematic chain for threading by cutting. In order to design the noncircular gears, the mathematical law of pitch variation has to be known. An analysis of pitch variation based on geometrical considerations was developed in the case of a double enveloping globoid worm. Subsequently, on the bases of a proper situation, a numerical model was determined. In this way, an approximately law of pitch variation was determined and it could be taken into consideration when designing the noncircular gears included in the kinematic chain of the cutting machine tool.

  13. A generalized and parameterized interference model for cognitive radio networks

    KAUST Repository

    Mahmood, Nurul Huda

    2011-06-01

    For meaningful co-existence of cognitive radios with primary system, it is imperative that the cognitive radio system is aware of how much interference it generates at the primary receivers. This can be done through statistical modeling of the interference as perceived at the primary receivers. In this work, we propose a generalized model for the interference generated by a cognitive radio network, in the presence of small and large scale fading, at a primary receiver located at the origin. We then demonstrate how this model can be used to estimate the impact of cognitive radio transmission on the primary receiver in terms of different outage probabilities. Finally, our analytical findings are validated through some selected computer-based simulations. © 2011 IEEE.

  14. Dynamic statistical models of biological cognition: insights from communications theory

    Science.gov (United States)

    Wallace, Rodrick

    2014-10-01

    Maturana's cognitive perspective on the living state, Dretske's insight on how information theory constrains cognition, the Atlan/Cohen cognitive paradigm, and models of intelligence without representation, permit construction of a spectrum of dynamic necessary conditions statistical models of signal transduction, regulation, and metabolism at and across the many scales and levels of organisation of an organism and its context. Nonequilibrium critical phenomena analogous to physical phase transitions, driven by crosstalk, will be ubiquitous, representing not only signal switching, but the recruitment of underlying cognitive modules into tunable dynamic coalitions that address changing patterns of need and opportunity at all scales and levels of organisation. The models proposed here, while certainly providing much conceptual insight, should be most useful in the analysis of empirical data, much as are fitted regression equations.

  15. Cognitive performance modeling based on general systems performance theory.

    Science.gov (United States)

    Kondraske, George V

    2010-01-01

    General Systems Performance Theory (GSPT) was initially motivated by problems associated with quantifying different aspects of human performance. It has proved to be invaluable for measurement development and understanding quantitative relationships between human subsystem capacities and performance in complex tasks. It is now desired to bring focus to the application of GSPT to modeling of cognitive system performance. Previous studies involving two complex tasks (i.e., driving and performing laparoscopic surgery) and incorporating measures that are clearly related to cognitive performance (information processing speed and short-term memory capacity) were revisited. A GSPT-derived method of task analysis and performance prediction termed Nonlinear Causal Resource Analysis (NCRA) was employed to determine the demand on basic cognitive performance resources required to support different levels of complex task performance. This approach is presented as a means to determine a cognitive workload profile and the subsequent computation of a single number measure of cognitive workload (CW). Computation of CW may be a viable alternative to measuring it. Various possible "more basic" performance resources that contribute to cognitive system performance are discussed. It is concluded from this preliminary exploration that a GSPT-based approach can contribute to defining cognitive performance models that are useful for both individual subjects and specific groups (e.g., military pilots).

  16. A cognitively plausible model for grammar induction

    Directory of Open Access Journals (Sweden)

    Roni Katzir

    2015-01-01

    Full Text Available This paper aims to bring theoretical linguistics and cognition-general theories of learning into closer contact. I argue that linguists' notions of rich UGs are well-founded, but that cognition-general learning approaches are viable as well and that the two can and should co-exist and support each other. Specifically, I use the observation that any theory of UG provides a learning criterion -- the total memory space used to store a grammar and its encoding of the input -- that supports learning according to the principle of Minimum Description-Length. This mapping from UGs to learners maintains a minimal ontological commitment: the learner for a particular UG uses only what is already required to account for linguistic competence in adults. I suggest that such learners should be our null hypothesis regarding the child's learning mechanism, and that furthermore, the mapping from theories of UG to learners provides a framework for comparing theories of UG.

  17. Schizophrenia: A Cognitive Model and Its Implications for Psychological Intervention.

    Science.gov (United States)

    Hemsley, David R.

    1996-01-01

    Proposes a cognitive model of schizophrenia stating that schizophrenic behavior is caused by a disturbance in sensory input and stored material integration. Cites research to support this model. Outlines the manner in which a disturbance in sensory input integration relates to schizophrenic symptoms and discusses the model's relevance for…

  18. Cognitive interference modeling with applications in power and admission control

    KAUST Repository

    Mahmood, Nurul Huda

    2012-10-01

    One of the key design challenges in a cognitive radio network is controlling the interference generated at coexisting primary receivers. In order to design efficient cognitive radio systems and to minimize their unwanted consequences, it is therefore necessary to effectively control the secondary interference at the primary receivers. In this paper, a generalized framework for the interference analysis of a cognitive radio network where the different secondary transmitters may transmit with different powers and transmission probabilities, is presented and various applications of this interference model are demonstrated. The findings of the analytical performance analyses are confirmed through selected computer-based Monte-Carlo simulations. © 2012 IEEE.

  19. On a Cognitive Model of Semiosis

    Directory of Open Access Journals (Sweden)

    Konderak Piotr

    2015-03-01

    Full Text Available What is the class of possible semiotic systems? What kinds of systems could count as such systems? The human mind is naturally considered the prototypical semiotic system. During years of research in semiotics the class has been broadened to include i.e. living systems (Zlatev, 2002 like animals, or even plants (Krampen, 1992. It is suggested in the literature on artificial intelligence that artificial agents are typical examples of symbol-processing entities. It also seems that (at least some semiotic processes are in fact cognitive processes. In consequence, it is natural to ask the question about the relation between semiotic studies and research on artificial cognitive systems within cognitive science. Consequently, my main question concerns the problem of inclusion or exclusion from the semiotic spectrum at least some artificial (computational systems. I would like to consider some arguments against the possibility of artificial semiotic systems and I will try to repeal them. Then I will present an existing natural-language using agent of the SNePS system and interpret it in terms of Peircean theory of signs. I would like also to show that some properties of semiotic systems in Peircean sense could be also found in a discussed artificial system. Finally, I will have some remarks on the status of semiotics in general.

  20. ARCHITECTURES AND ALGORITHMS FOR COGNITIVE NETWORKS ENABLED BY QUALITATIVE MODELS

    DEFF Research Database (Denmark)

    Balamuralidhar, P.

    2013-01-01

    the qualitative models in a cognitive engine. Further I use the methodology in multiple functional scenarios of cognitive networks including self- optimization and self- monitoring. In the case of self-optimization, I integrate principles from monotonicity analysis to evaluate and enhance qualitative models......Complexity of communication networks is ever increasing and getting complicated by their heterogeneity and dynamism. Traditional techniques are facing challenges in network performance management. Cognitive networking is an emerging paradigm to make networks more intelligent, thereby overcoming...... traditional limitations and potentially achieving better performance. The vision is that, networks should be able to monitor themselves, reason upon changes in self and environment, act towards the achievement of specific goals and learn from experience. The concept of a Cognitive Engine (CE) supporting...

  1. FORMATION AND EVOLUTION OF A MULTI-THREADED SOLAR PROMINENCE

    Energy Technology Data Exchange (ETDEWEB)

    Luna, M. [CRESST and Space Weather Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States); Karpen, J. T. [NASA/GSFC, Greenbelt, MD 20771 (United States); DeVore, C. R. [Naval Research Laboratory, Washington, DC 20375 (United States)

    2012-02-10

    We investigate the process of formation and subsequent evolution of prominence plasma in a filament channel and its overlying arcade. We construct a three-dimensional time-dependent model of an intermediate quiescent prominence suitable to be compared with observations. We combine the magnetic field structure of a three-dimensional sheared double arcade with one-dimensional independent simulations of many selected flux tubes, in which the thermal nonequilibrium process governs the plasma evolution. We have found that the condensations in the corona can be divided into two populations: threads and blobs. Threads are massive condensations that linger in the flux tube dips. Blobs are ubiquitous small condensations that are produced throughout the filament and overlying arcade magnetic structure, and rapidly fall to the chromosphere. The threads are the principal contributors to the total mass, whereas the blob contribution is small. The total prominence mass is in agreement with observations, assuming reasonable filling factors of order 0.001 and a fixed number of threads. The motion of the threads is basically horizontal, while blobs move in all directions along the field. We have generated synthetic images of the whole structure in an H{alpha} proxy and in two EUV channels of the Atmospheric Imaging Assembly instrument on board Solar Dynamics Observatory, thus showing the plasma at cool, warm, and hot temperatures. The predicted differential emission measure of our system agrees very well with observations in the temperature range log T = 4.6-5.7. We conclude that the sheared-arcade magnetic structure and plasma behavior driven by thermal nonequilibrium fit the abundant observational evidence well for typical intermediate prominences.

  2. Formation and Evolution of a Multi-threaded Solar Prominence

    Science.gov (United States)

    Luna, M.; Karpen, J. T.; DeVore, C. R.

    2012-02-01

    We investigate the process of formation and subsequent evolution of prominence plasma in a filament channel and its overlying arcade. We construct a three-dimensional time-dependent model of an intermediate quiescent prominence suitable to be compared with observations. We combine the magnetic field structure of a three-dimensional sheared double arcade with one-dimensional independent simulations of many selected flux tubes, in which the thermal nonequilibrium process governs the plasma evolution. We have found that the condensations in the corona can be divided into two populations: threads and blobs. Threads are massive condensations that linger in the flux tube dips. Blobs are ubiquitous small condensations that are produced throughout the filament and overlying arcade magnetic structure, and rapidly fall to the chromosphere. The threads are the principal contributors to the total mass, whereas the blob contribution is small. The total prominence mass is in agreement with observations, assuming reasonable filling factors of order 0.001 and a fixed number of threads. The motion of the threads is basically horizontal, while blobs move in all directions along the field. We have generated synthetic images of the whole structure in an Hα proxy and in two EUV channels of the Atmospheric Imaging Assembly instrument on board Solar Dynamics Observatory, thus showing the plasma at cool, warm, and hot temperatures. The predicted differential emission measure of our system agrees very well with observations in the temperature range log T = 4.6-5.7. We conclude that the sheared-arcade magnetic structure and plasma behavior driven by thermal nonequilibrium fit the abundant observational evidence well for typical intermediate prominences.

  3. Polyelectrolyte Threading through a Nanopore

    Directory of Open Access Journals (Sweden)

    Pai-Yi Hsiao

    2016-03-01

    Full Text Available Threading charged polymers through a nanopore, driven by electric fields E, is investigated by means of Langevin dynamics simulations. The mean translocation time 〈 τ 〉 is shown to follow a scaling law Nα, and the exponent α increases monotonically from 1.16 (4 to 1.40 (3 with E. The result is double-checked by the calculation of mean square displacement of translocation coordinate, which asserts a scaling behavior tβ (for t near τ with β complying with the relation αβ = 2. At a fixed chain length N, 〈τ〉 displayed a reciprocal scaling behavior E−1 in the weak and also in the strong fields, connected by a transition E−1.64(5 in the intermediate fields. The variations of the radius of gyration of chain and the positions of chain end are monitored during a translocation process; far-from-equilibrium behaviors are observed when the driving field is strong. A strong field can strip off the condensed ions on the chain when it passes the pore. The total charges of condensed ions are hence decreased. The studies for the probability and density distributions reveal that the monomers in the trans-region are gathered near the wall and form a pancake-like density profile with a hump cloud over it in the strong fields, due to fast translocation.

  4. The implicit possibility of dualism in quantum probabilistic cognitive modeling.

    Science.gov (United States)

    Mender, Donald

    2013-06-01

    Pothos & Busemeyer (P&B) argue convincingly that quantum probability offers an improvement over classical Bayesian probability in modeling the empirical data of cognitive science. However, a weakness related to restrictions on the dimensionality of incompatible physical observables flows from the authors' "agnosticism" regarding quantum processes in neural substrates underlying cognition. Addressing this problem will require either future research findings validating quantum neurophysics or theoretical expansion of the uncertainty principle as a new, neurocognitively contextualized, "local" symmetry.

  5. Exploring the cognitive and motor functions of the basal ganglia: an integrative review of computational cognitive neuroscience models

    OpenAIRE

    Sebastien eHelie; Srinivasa eChakravarthy; Ahmed A. Moustafa

    2013-01-01

    Many computational models of the basal ganglia have been proposed over the past twenty-five years. While computational neuroscience models have focused on closely matching the neurobiology of the basal ganglia, computational cognitive neuroscience models have focused on how the basal ganglia can be used to implement cognitive and motor functions. This review article focuses on computational cognitive neuroscience models of the basal ganglia and how they use the neuroanatomy of the basal gangl...

  6. Exploring EFL Teachers’ Cognitive Models Through Metaphor Analysis

    Directory of Open Access Journals (Sweden)

    Hui Xiong

    2015-10-01

    Full Text Available This study aims to investigate how a group of Chinese university teachers developed their cognitive models by using “English as a Foreign Language (EFL teachers” metaphors. The research method includes an open-ended questionnaire, a checklist questionnaire, and verbal reports. The goal for this research is twofold. First, we will present those metaphors we believe to be the most frequently used or most central in shaping the thoughts or ideas they have had for EFL teaching and learning. Second, we will provide a description of their internal process of developing cognitive models, as well as factors that could account for such models. The findings showed that (a most of us had three ways of understanding EFL teachers in terms of the educational journey metaphor, the educational building metaphor, and the educational conduit metaphor; (b we used such a cluster of converging cognitive models as the instructor model, the transmitter model, and the builder model to construct definitions for EFL teachers, with the instructor model as a central model; and (c metaphor can actually serve as a useful, effective, and analytic tool for making us aware of the cognitive model underlying our conceptual framework.

  7. Cognitive Modeling for Agent-Based Simulation of Child Maltreatment

    Science.gov (United States)

    Hu, Xiaolin; Puddy, Richard

    This paper extends previous work to develop cognitive modeling for agent-based simulation of child maltreatment (CM). The developed model is inspired from parental efficacy, parenting stress, and the theory of planned behavior. It provides an explanatory, process-oriented model of CM and incorporates causality relationship and feedback loops from different factors in the social ecology in order for simulating the dynamics of CM. We describe the model and present simulation results to demonstrate the features of this model.

  8. Conversation Threads Hidden within Email Server Logs

    Science.gov (United States)

    Palus, Sebastian; Kazienko, Przemysław

    Email server logs contain records of all email Exchange through this server. Often we would like to analyze those emails not separately but in conversation thread, especially when we need to analyze social network extracted from those email logs. Unfortunately each mail is in different record and those record are not tided to each other in any obvious way. In this paper method for discussion threads extraction was proposed together with experiments on two different data sets - Enron and WrUT..

  9. A cognitive computational model inspired by the immune system response.

    Science.gov (United States)

    Abdo Abd Al-Hady, Mohamed; Badr, Amr Ahmed; Mostafa, Mostafa Abd Al-Azim

    2014-01-01

    The immune system has a cognitive ability to differentiate between healthy and unhealthy cells. The immune system response (ISR) is stimulated by a disorder in the temporary fuzzy state that is oscillating between the healthy and unhealthy states. However, modeling the immune system is an enormous challenge; the paper introduces an extensive summary of how the immune system response functions, as an overview of a complex topic, to present the immune system as a cognitive intelligent agent. The homogeneity and perfection of the natural immune system have been always standing out as the sought-after model we attempted to imitate while building our proposed model of cognitive architecture. The paper divides the ISR into four logical phases: setting a computational architectural diagram for each phase, proceeding from functional perspectives (input, process, and output), and their consequences. The proposed architecture components are defined by matching biological operations with computational functions and hence with the framework of the paper. On the other hand, the architecture focuses on the interoperability of main theoretical immunological perspectives (classic, cognitive, and danger theory), as related to computer science terminologies. The paper presents a descriptive model of immune system, to figure out the nature of response, deemed to be intrinsic for building a hybrid computational model based on a cognitive intelligent agent perspective and inspired by the natural biology. To that end, this paper highlights the ISR phases as applied to a case study on hepatitis C virus, meanwhile illustrating our proposed architecture perspective.

  10. The Cognitive Complexity in Modelling the Group Decision Process

    Directory of Open Access Journals (Sweden)

    Barna Iantovics

    2010-06-01

    Full Text Available The paper investigates for some basic contextual factors (such
    us the problem complexity, the users' creativity and the problem space complexity the cognitive complexity associated with modelling the group decision processes (GDP in e-meetings. The analysis is done by conducting a socio-simulation experiment for an envisioned collaborative software tool that acts as a stigmergic environment for modelling the GDP. The simulation results revels some interesting design guidelines for engineering some contextual functionalities that minimize the cognitive complexity associated with modelling the GDP.

  11. Neural and Cognitive Modeling with Networks of Leaky Integrator Units

    Science.gov (United States)

    Graben, Peter beim; Liebscher, Thomas; Kurths, Jürgen

    After reviewing several physiological findings on oscillations in the electroencephalogram (EEG) and their possible explanations by dynamical modeling, we present neural networks consisting of leaky integrator units as a universal paradigm for neural and cognitive modeling. In contrast to standard recurrent neural networks, leaky integrator units are described by ordinary differential equations living in continuous time. We present an algorithm to train the temporal behavior of leaky integrator networks by generalized back-propagation and discuss their physiological relevance. Eventually, we show how leaky integrator units can be used to build oscillators that may serve as models of brain oscillations and cognitive processes.

  12. Computational model of sustained acceleration effects on human cognitive performance.

    Science.gov (United States)

    McKinlly, Richard A; Gallimore, Jennie J

    2013-08-01

    Extreme acceleration maneuvers encountered in modern agile fighter aircraft can wreak havoc on human physiology, thereby significantly influencing cognitive task performance. As oxygen content declines under acceleration stress, the activity of high order cortical tissue reduces to ensure sufficient metabolic resources are available for critical life-sustaining autonomic functions. Consequently, cognitive abilities reliant on these affected areas suffer significant performance degradations. The goal was to develop and validate a model capable of predicting human cognitive performance under acceleration stress. Development began with creation of a proportional control cardiovascular model that produced predictions of several hemodynamic parameters, including eye-level blood pressure and regional cerebral oxygen saturation (rSo2). An algorithm was derived to relate changes in rSo2 within specific brain structures to performance on cognitive tasks that require engagement of different brain areas. Data from the "precision timing" experiment were then used to validate the model predicting cognitive performance as a function of G(z) profile. The following are value ranges. Results showed high agreement between the measured and predicted values for the rSo2 (correlation coefficient: 0.7483-0.8687; linear best-fit slope: 0.5760-0.9484; mean percent error: 0.75-3.33) and cognitive performance models (motion inference task--correlation coefficient: 0.7103-0.9451; linear best-fit slope: 0.7416-0.9144; mean percent error: 6.35-38.21; precision timing task--correlation coefficient: 0.6856-0.9726; linear best-fit slope: 0.5795-1.027; mean percent error: 6.30-17.28). The evidence suggests that the model is capable of accurately predicting cognitive performance of simplistic tasks under high acceleration stress.

  13. ADVANCED SCHEDULER FOR COOPERATIVE EXECUTION OF THREADS ON MULTI-CORE SYSTEM

    Directory of Open Access Journals (Sweden)

    O. N. Karasik

    2017-01-01

    Full Text Available Three architectures of the cooperative thread scheduler in a multithreaded application that is executed on a multi-core system are considered. Architecture A0 is based on the synchronization and scheduling facilities, which are provided by the operating system. Architecture A1 introduces a new synchronization primitive and a single queue of the blocked threads in the scheduler, which reduces the interaction activity between the threads and operating system, and significantly speed up the processes of blocking and unblocking the threads. Architecture A2 replaces the single queue of blocked threads with dedicated queues, one for each of the synchronizing primitives, extends the number of internal states of the primitive, reduces the inter- dependence of the scheduling threads, and further significantly speeds up the processes of blocking and unblocking the threads. All scheduler architectures are implemented on Windows operating systems and based on the User Mode Scheduling. Important experimental results are obtained for multithreaded applications that implement two blocked parallel algorithms of solving the linear algebraic equation systems by the Gaussian elimination. The algorithms differ in the way of the data distribution among threads and by the thread synchronization models. The number of threads varied from 32 to 7936. Architecture A1 shows the acceleration of up to 8.65% and the architecture A2 shows the acceleration of up to 11.98% compared to A0 architecture for the blocked parallel algorithms computing the triangular form and performing the back substitution. On the back substitution stage of the algorithms, architecture A1 gives the acceleration of up to 125%, and architecture A2 gives the acceleration of up to 413% compared to architecture A0. The experiments clearly show that the proposed architectures, A1 and A2 outperform A0 depending on the number of thread blocking and unblocking operations, which happen during the execution of

  14. A COGNITIVE APPROACH TO CORPORATE GOVERNANCE: A VISUALIZATION TEST OF MENTAL MODELS WITH THE COGNITIVE MAPPING TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Garoui NASSREDDINE

    2012-01-01

    Full Text Available The idea of this paper is to determine the mental models of actors in the fi rm with respect to the cognitive approach of corporate governance. The paper takes a corporate governance perspective, discusses mental models and uses the cognitive map to view the diagrams showing the ways of thinking and the conceptualization of the cognitive approach. In addition, it employs a cognitive mapping technique. Returning to the systematic exploration of grids for each actor, it concludes that there is a balance of concepts expressing their cognitive orientation.

  15. Model of music cognition and amusia.

    Science.gov (United States)

    García-Casares, N; Berthier Torres, M L; Froudist Walsh, S; González-Santos, P

    2013-04-01

    The study of the neural networks involved in music processing has received less attention than work researching the brain's language networks. For the last two decades there has been a growing interest in discovering the functional mechanisms of the musical brain and understanding those disorders in which brain regions linked with perception and production of music are damaged. Congenital and acquired musical deficits in their various forms (perception, execution, music-memory) are grouped together under the generic term amusia. In this selective review we present the "cutting edge" studies on the cognitive and neural processes implicated in music and the various forms of amusia. Musical processing requires a large cortico-subcortical network which is distributed throughout both cerebral hemispheres and the cerebellum. The analysis of healthy subjects using functional neuroimaging and examination of selective deficits (e.g., tone, rhythm, timbre, melodic contours) in patients will improve our knowledge of the mechanisms involved in musical processing and the latter's relationship with other cognitive processes. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

  16. Bioabsorbable thread for tight tying of bones.

    Science.gov (United States)

    Hattori, K; Tomita, N; Tamai, S; Ikada, Y

    2000-01-01

    The purpose of this research was to develop a bioabsorbable thread for tight fixation of fractured bones and to examine its mechanical performance in an in-vitro simulation study. The thread is a blend of bioabsorbable poly(L-lactic acid); (PLLA) and poly(epsilon-caprolactone); (PCL) fibers and can be tightly connected by fusion welding of the PCL fibers. The tying strength of the PLLA-PCL blend thread was 39.7 N, which was comparable to that of stainless steel wire. A testing machine was fabricated to measure the fatigue strength of the tying by simulating bone fixation. The results showed that metal wires always failed because of breakage within 25,000 loading cycles, whereas the blend threads did not fail until 50,000 loading cycles. The looseness of tying for simulated bone fixation by the blend thread was within 1mm even after 50 000 loading cycles. In-vivo testing using rats revealed that the blend thread did not cause any severe inflammatory reaction.

  17. 46 CFR 164.023-5 - Performance; standard thread.

    Science.gov (United States)

    2010-10-01

    ... Performance; standard thread. (a) Use Codes 1, 2, 3, 4BC, 4RB, 5 (any). Each thread which complies with all of... Polyester 24 through 12. MIL-T-43548C Polyester covered only 24 through 12. (b) Use Code 4B. Each thread... 46 Shipping 6 2010-10-01 2010-10-01 false Performance; standard thread. 164.023-5 Section...

  18. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in

  19. Modeling Epistemic and Ontological Cognition: Philosophical Perspectives and Methodological Directions

    Science.gov (United States)

    Greene, Jeffrey A.; Azevedo, Roger A.; Torney-Purta, Judith

    2008-01-01

    We propose an integration of aspects of several developmental and systems of beliefs models of personal epistemology. Qualitatively different positions, including realism, dogmatism, skepticism, and rationalism, are characterized according to individuals' beliefs across three dimensions in a model of epistemic and ontological cognition. This model…

  20. Human strategic reasoning in dynamic games: Experiments, logics, cognitive models

    NARCIS (Netherlands)

    Ghosh, Sujata; Halder, Tamoghna; Sharma, Khyati; Verbrugge, Rineke

    2015-01-01

    © Springer-Verlag Berlin Heidelberg 2015.This article provides a three-way interaction between experiments, logic and cognitive modelling so as to bring out a shared perspective among these diverse areas, aiming towards better understanding and better modelling of human strategic reasoning in dynami

  1. A PREDICTABLE MULTI-THREADED MAIN-MEMORY STORAGE MANAGER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper introduces the design and implementation of a predictable multi-threaded main-memo- ry storage manager (CS20), and emphasizes the database service mediator(DSM), an operation prediction model using exponential averaging. The memory manager, indexing, as well as lock manager in CS20 are also presented briefly. CS20 has been embedded in a mobile telecommunication service system. Practice showed, DSM effectively controls system load and hence improves the real-time characteristics of data accessing.

  2. Designing e-learning cognitively: TSOI Hybrid Learning Model

    Directory of Open Access Journals (Sweden)

    Mun Fie Tsoi

    2008-08-01

    Full Text Available Research on learning has proposed various models for learning. However, generally, there has been an inadequate research of the application of these models for learning for example the Kolb’s experiential learning cycle or the Jarvis’s model of reflection and learning to the development of e-learning materials. This is more so especially due to lack of effective yet practical design model for designing interactive e-learning materials. Having this in mind, the TSOI Hybrid Learning Model can be used as a pedagogic model for the cognitive design of e-learning. This Model represents learning as a cyclical cognitive process. A major feature is to promote active cognitive processing in the learner for meaningful learning proceeding from inductive to deductive. Design specificity in science and chemistry education is illustrated in terms of instructional storyboarding and the research-based e-learning product developed. Learners’ cognitive abilities will be addressed as part of the research data collected.

  3. Toward a model-based cognitive neuroscience of mind wandering.

    Science.gov (United States)

    Hawkins, G E; Mittner, M; Boekel, W; Heathcote, A; Forstmann, B U

    2015-12-03

    People often "mind wander" during everyday tasks, temporarily losing track of time, place, or current task goals. In laboratory-based tasks, mind wandering is often associated with performance decrements in behavioral variables and changes in neural recordings. Such empirical associations provide descriptive accounts of mind wandering - how it affects ongoing task performance - but fail to provide true explanatory accounts - why it affects task performance. In this perspectives paper, we consider mind wandering as a neural state or process that affects the parameters of quantitative cognitive process models, which in turn affect observed behavioral performance. Our approach thus uses cognitive process models to bridge the explanatory divide between neural and behavioral data. We provide an overview of two general frameworks for developing a model-based cognitive neuroscience of mind wandering. The first approach uses neural data to segment observed performance into a discrete mixture of latent task-related and task-unrelated states, and the second regresses single-trial measures of neural activity onto structured trial-by-trial variation in the parameters of cognitive process models. We discuss the relative merits of the two approaches, and the research questions they can answer, and highlight that both approaches allow neural data to provide additional constraint on the parameters of cognitive models, which will lead to a more precise account of the effect of mind wandering on brain and behavior. We conclude by summarizing prospects for mind wandering as conceived within a model-based cognitive neuroscience framework, highlighting the opportunities for its continued study and the benefits that arise from using well-developed quantitative techniques to study abstract theoretical constructs.

  4. Can quantum probability provide a new direction for cognitive modeling?

    Science.gov (United States)

    Pothos, Emmanuel M; Busemeyer, Jerome R

    2013-06-01

    Classical (Bayesian) probability (CP) theory has led to an influential research tradition for modeling cognitive processes. Cognitive scientists have been trained to work with CP principles for so long that it is hard even to imagine alternative ways to formalize probabilities. However, in physics, quantum probability (QP) theory has been the dominant probabilistic approach for nearly 100 years. Could QP theory provide us with any advantages in cognitive modeling as well? Note first that both CP and QP theory share the fundamental assumption that it is possible to model cognition on the basis of formal, probabilistic principles. But why consider a QP approach? The answers are that (1) there are many well-established empirical findings (e.g., from the influential Tversky, Kahneman research tradition) that are hard to reconcile with CP principles; and (2) these same findings have natural and straightforward explanations with quantum principles. In QP theory, probabilistic assessment is often strongly context- and order-dependent, individual states can be superposition states (that are impossible to associate with specific values), and composite systems can be entangled (they cannot be decomposed into their subsystems). All these characteristics appear perplexing from a classical perspective. However, our thesis is that they provide a more accurate and powerful account of certain cognitive processes. We first introduce QP theory and illustrate its application with psychological examples. We then review empirical findings that motivate the use of quantum theory in cognitive theory, but also discuss ways in which QP and CP theories converge. Finally, we consider the implications of a QP theory approach to cognition for human rationality.

  5. Computational cognitive modeling for the diagnosis of Specific Language Impairment.

    Science.gov (United States)

    Oliva, Jesus; Serrano, J Ignacio; del Castillo, M Dolores; Iglesias, Angel

    2013-01-01

    Specific Language Impairment (SLI), as many other cognitive deficits, is difficult to diagnose given its heterogeneous profile and its overlap with other impairments. Existing techniques are based on different criteria using behavioral variables on different tasks. In this paper we propose a methodology for the diagnosis of SLI that uses computational cognitive modeling in order to capture the internal mechanisms of the normal and impaired brain. We show that machine learning techniques that use the information of these models perform better than those that only use behavioral variables.

  6. Modelling application for cognitive reliability and error analysis method

    Directory of Open Access Journals (Sweden)

    Fabio De Felice

    2013-10-01

    Full Text Available The automation of production systems has delegated to machines the execution of highly repetitive and standardized tasks. In the last decade, however, the failure of the automatic factory model has led to partially automated configurations of production systems. Therefore, in this scenario, centrality and responsibility of the role entrusted to the human operators are exalted because it requires problem solving and decision making ability. Thus, human operator is the core of a cognitive process that leads to decisions, influencing the safety of the whole system in function of their reliability. The aim of this paper is to propose a modelling application for cognitive reliability and error analysis method.

  7. A computational model of perception and action for cognitive robotics.

    Science.gov (United States)

    Haazebroek, Pascal; van Dantzig, Saskia; Hommel, Bernhard

    2011-11-01

    Robots are increasingly expected to perform tasks in complex environments. To this end, engineers provide them with processing architectures that are based on models of human information processing. In contrast to traditional models, where information processing is typically set up in stages (i.e., from perception to cognition to action), it is increasingly acknowledged by psychologists and robot engineers that perception and action are parts of an interactive and integrated process. In this paper, we present HiTEC, a novel computational (cognitive) model that allows for direct interaction between perception and action as well as for cognitive control, demonstrated by task-related attentional influences. Simulation results show that key behavioral studies can be readily replicated. Three processing aspects of HiTEC are stressed for their importance for cognitive robotics: (1) ideomotor learning of action control, (2) the influence of task context and attention on perception, action planning, and learning, and (3) the interaction between perception and action planning. Implications for the design of cognitive robotics are discussed.

  8. For a Cognitive Model of Subjective Memory Awareness.

    Science.gov (United States)

    Dalla Barba, Gianfranco; La Corte, Valentina; Dubois, Bruno

    2015-09-24

    The clinical challenge in subjective memory decline (SMD) is to identify which individuals will present memory deficits. Since its early description from Babinsky, who coined the term 'anosognosia' (i.e., the lack of awareness of deficit), the awareness of cognitive impairment is crucial in clinical neuropsychology. We propose a cognitive model in which SMD and anosognosia can be considered two opposite forms of distorted awareness of cognitive performance and can be accounted for within a model in which consciousness of memory performance can vary in a continuum from normal awareness of performance (preserved or impaired) to anosognosia through a disorder of consciousness related to SMD that we call "cognitive dysgnosia", i.e., awareness of normal performance as impaired. This model suggests that the neuropsychological assessment of memory performance should always be coupled with a deep evaluation of awareness of the subject's memory profile, which allow to better identify the disorder of consciousness with or without cognitive impairment. In this line, it seems necessary to develop more sensitive neuropsychological tools in order to discriminate, within the SMD, individuals who are likely to develop clinical Alzheimer's disease from those whose memory decline complaint is not associated with an underlying neurodegenerative pathology.

  9. Dynamic scene stitching driven by visual cognition model.

    Science.gov (United States)

    Zou, Li-hui; Zhang, Dezheng; Wulamu, Aziguli

    2014-01-01

    Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  10. Dynamic Scene Stitching Driven by Visual Cognition Model

    Directory of Open Access Journals (Sweden)

    Li-hui Zou

    2014-01-01

    Full Text Available Dynamic scene stitching still has a great challenge in maintaining the global key information without missing or deforming if multiple motion interferences exist in the image acquisition system. Object clips, motion blurs, or other synthetic defects easily occur in the final stitching image. In our research work, we proceed from human visual cognitive mechanism and construct a hybrid-saliency-based cognitive model to automatically guide the video volume stitching. The model consists of three elements of different visual stimuli, that is, intensity, edge contour, and scene depth saliencies. Combined with the manifold-based mosaicing framework, dynamic scene stitching is formulated as a cut path optimization problem in a constructed space-time graph. The cutting energy function for column width selections is defined according to the proposed visual cognition model. The optimum cut path can minimize the cognitive saliency difference throughout the whole video volume. The experimental results show that it can effectively avoid synthetic defects caused by different motion interferences and summarize the key contents of the scene without loss. The proposed method gives full play to the role of human visual cognitive mechanism for the stitching. It is of high practical value to environmental surveillance and other applications.

  11. Modeling and Evaluating Emotions Impact on Cognition

    Science.gov (United States)

    2013-07-01

    International Conference on Automatic Face and Gesture Recognition . Shanghai, China, April 2013 • Wenji Mao and Jonathan Gratch. Modeling Social...Modeling, Lorentz Center, Leiden. August 2011 • Keynote speaker, IEEE International Conference on Automatic Face and Gesture Recognition , Santa

  12. The linear and nonlinear stability of thread-annular flow.

    Science.gov (United States)

    Walton, Andrew G

    2005-05-15

    The surgical technique of thread injection of medical implants is modelled by the axial pressure-gradient-driven flow between concentric cylinders with a moving core. The linear stability of the flow to both axisymmetric and asymmetric perturbations is analysed asymptotically at large Reynolds number, and computationally at finite Reynolds number. The existence of multiple regions of instability is predicted and their dependence upon radius ratio and thread velocity is determined. A discrepancy in critical Reynolds numbers and cut-off velocity is found to exist between experimental results and the predictions of the linear theory. In order to account for this discrepancy, the high Reynolds number, nonlinear stability properties of the flow are analysed and a nonlinear, equilibrium critical layer structure is found, which leads to an enhanced correction to the basic flow. The predictions of the nonlinear theory are found to be in good agreement with the experimental data.

  13. The Role of Cognitive Modeling in Achieving Communicative Intentions

    CERN Document Server

    Walker, M; Walker, Marilyn; Rambow, Owen

    1994-01-01

    A discourse planner for (task-oriented) dialogue must be able to make choices about whether relevant, but optional information (for example, the "satellites" in an RST-based planner) should be communicated. We claim that effective text planners must explicitly model aspects of the Hearer's cognitive state, such as what the hearer is attending to and what inferences the hearer can draw, in order to make these choices. We argue that a mere representation of the Hearer's knowledge is inadequate. We support this claim by (1) an analysis of naturally occurring dialogue, and (2) by simulating the generation of discourses in a situation in which we can vary the cognitive parameters of the hearer. Our results show that modeling cognitive state can lead to more effective discourses (measured with respect to a simple task).

  14. MAGELLAN: a cognitive map-based model of human wayfinding.

    Science.gov (United States)

    Manning, Jeremy R; Lew, Timothy F; Li, Ningcheng; Sekuler, Robert; Kahana, Michael J

    2014-06-01

    In an unfamiliar environment, searching for and navigating to a target requires that spatial information be acquired, stored, processed, and retrieved. In a study encompassing all of these processes, participants acted as taxicab drivers who learned to pick up and deliver passengers in a series of small virtual towns. We used data from these experiments to refine and validate MAGELLAN, a cognitive map-based model of spatial learning and wayfinding. MAGELLAN accounts for the shapes of participants' spatial learning curves, which measure their experience-based improvement in navigational efficiency in unfamiliar environments. The model also predicts the ease (or difficulty) with which different environments are learned and, within a given environment, which landmarks will be easy (or difficult) to localize from memory. Using just 2 free parameters, MAGELLAN provides a useful account of how participants' cognitive maps evolve over time with experience, and how participants use the information stored in their cognitive maps to navigate and explore efficiently.

  15. 富网络调度界面的多事件线程快速GAS回调模式%Fast GAS Callback Model of Multi-Event Threads for RIA Dispatch Automation Interface

    Institute of Scientific and Technical Information of China (English)

    屈志坚; 应康兴; 赵亮; 陈宇菲

    2016-01-01

    针对配电网调度监控图形界面的部署和图元处理效率不高的问题,将矢量图元嵌入富网络组件容器的应用框架中,提出一种富网络架构的调度界面快速GAS监控新模式。基于异步分层回调框架,综合运用GWT交叉编译、JSNI本地化接口和支持多事件线程的并发回调机制,给出了调度图形界面关键代码的编译处理流程,实现了调度监控界面免部署和矢量图元的局部刷新。以10 kV配电网调度自动化系统为算例,对调度监控界面进行了渗入测试和并发测试,结果表明:异步回调主机可获得小于20%的处理器使用率和7%的内存占有率,SVG 界面的多事件线程局部刷新和异步回调机制,使监控画面平均刷新延时降为百毫秒级,验证了GAS模式对提高界面响应能力的有效性。%In order to solve problem of graphic interface deployment and low efficiency of graphic element processing in distribution network dispatch supervisory system, a fast GAS dispatch interface callback model based on rich internet architecture is put forward by embedding vector elements into component containers and rich internet application framework. Based on layered asynchronous callback framework, a compilation process of key codes for scheduling graphic interface is given, and free deployment and partial refresh are implemented by coordinating GWT cross compiling technology, JSNI native interface and multiple event threads supported by asynchronous callback mechanism. Taking a 10kV distribution network dispatch monitoring system as example, results of penetration and concurrent test show that host of asynchronous callbacks gets less than 20 percent of processor and 7 percent of memory share, and average delay of monitor screens can be reduced to level of hundreds milliseconds by using multi-threads partial refresh. Monitoring efficiency of GAS model is verified.

  16. The potential of using quantum theory to build models of cognition.

    Science.gov (United States)

    Wang, Zheng; Busemeyer, Jerome R; Atmanspacher, Harald; Pothos, Emmanuel M

    2013-10-01

    Quantum cognition research applies abstract, mathematical principles of quantum theory to inquiries in cognitive science. It differs fundamentally from alternative speculations about quantum brain processes. This topic presents new developments within this research program. In the introduction to this topic, we try to answer three questions: Why apply quantum concepts to human cognition? How is quantum cognitive modeling different from traditional cognitive modeling? What cognitive processes have been modeled using a quantum account? In addition, a brief introduction to quantum probability theory and a concrete example is provided to illustrate how a quantum cognitive model can be developed to explain paradoxical empirical findings in psychological literature.

  17. Computational Modeling and Simulation of Attitude Change. Part 1, Connectionist Models and Simulations of Cognitive Dissonance: an Overview

    OpenAIRE

    Voinea, Camelia Florela

    2013-01-01

    Cognitive Dissonance Theory is considered part of the cognitive consistency theories in Social Psychology. They uncover a class of conceptual models which describe the attitude change as a cognitive consistency-seeking issue. As these conceptual models requested more complex operational expression, algebraic, mathematical and, lately, computational modeling approaches of cognitive consistency have been developed. Part 1 of this work provides an overview of the connectionist modeling of cognit...

  18. Computational Modeling and Simulation of Attitude Change. Part 1, Connectionist Models and Simulations of Cognitive Dissonance: an Overview

    OpenAIRE

    Voinea, Camelia Florela

    2013-01-01

    Cognitive Dissonance Theory is considered part of the cognitive consistency theories in Social Psychology. They uncover a class of conceptual models which describe the attitude change as a cognitive consistency-seeking issue. As these conceptual models requested more complex operational expression, algebraic, mathematical and, lately, computational modeling approaches of cognitive consistency have been developed. Part 1 of this work provides an overview of the connectionist modeling of cognit...

  19. A Multi-Threaded Semantic Focused Crawler

    Institute of Scientific and Technical Information of China (English)

    Punam Bedi; Anjali Thukral; Hema Banati; Abhishek Behl; Varun Mendiratta

    2012-01-01

    The Web comprises of voluminous rich learning content.The volume of ever growing learning resources however leads to the problem of information overload.A large number of irrelevant search results generated from search engines based on keyword matching techniques further augment the problem.A learner in such a scenario needs semantically matched learning resources as the search results.Keeping in view the volume of content and significance of semantic knowledge,our paper proposes a multi-threaded semantic focused crawler (SFC) specially designed and implemented to crawl on the WWW for educational learning content.The proposed SFC utilizes domain ontology to expand a topic term and a set of seed URLs to initiate the crawl.The results obtained by multiple iterations of the crawl on various topics are shown and compared with the results obtained by executing an open source crawler on the similar dataset.The results are evaluated using Semantic Similarity,a vector space model based metric,and the harvest ratio.

  20. Computational models of music perception and cognition I: The perceptual and cognitive processing chain

    Science.gov (United States)

    Purwins, Hendrik; Herrera, Perfecto; Grachten, Maarten; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    We present a review on perception and cognition models designed for or applicable to music. An emphasis is put on computational implementations. We include findings from different disciplines: neuroscience, psychology, cognitive science, artificial intelligence, and musicology. The article summarizes the methodology that these disciplines use to approach the phenomena of music understanding, the localization of musical processes in the brain, and the flow of cognitive operations involved in turning physical signals into musical symbols, going from the transducers to the memory systems of the brain. We discuss formal models developed to emulate, explain and predict phenomena involved in early auditory processing, pitch processing, grouping, source separation, and music structure computation. We cover generic computational architectures of attention, memory, and expectation that can be instantiated and tuned to deal with specific musical phenomena. Criteria for the evaluation of such models are presented and discussed. Thereby, we lay out the general framework that provides the basis for the discussion of domain-specific music models in Part II.

  1. Facial thread lifting with suture suspension.

    Science.gov (United States)

    Tavares, Joana de Pinho; Oliveira, Carlos Augusto Costa Pires; Torres, Rodolfo Prado; Bahmad, Fayez

    2017-05-09

    The increased interest in minimally-invasive treatments, such as the thread lifting, with lower risk of complications, minimum length of time away from work and effectiveness in correcting ptosis and aging characteristics has led many specialists to adopt this technique, but many doubts about its safety and effectiveness still limit its overall use. To analyze data published in the literature on the durability of results, their effectiveness, safety, and risk of serious adverse events associated with procedures using several types of threading sutures. Literature review using the key words "thread lift", "barbed suture", "suture suspension" and "APTOS". Due to the scarcity of literature, recent reports of facial lifting using threads were also selected, complemented with bibliographical references. The first outcomes of facial lifting with barbed sutures remain inconclusive. Adverse events may occur, although they are mostly minor, self-limiting, and short-lived. The data on the maximum effect of the correction, the durability of results, and the consequences of the long-term suture stay are yet to be clarified. Interest in thread lifting is currently high, but this review suggests that it should not yet be adopted as an alternative to rhytidectomy. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  2. Using data-driven model-brain mappings to constrain formal models of cognition

    NARCIS (Netherlands)

    Borst, Jelmer P; Nijboer, Menno; Taatgen, Niels A; van Rijn, Hedderik; Anderson, John R

    2015-01-01

    In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping f

  3. Exploring the dynamics of collective cognition using a computational model of cognitive dissonance

    Science.gov (United States)

    Smart, Paul R.; Sycara, Katia; Richardson, Darren P.

    2013-05-01

    The socially-distributed nature of cognitive processing in a variety of organizational settings means that there is increasing scientific interest in the factors that affect collective cognition. In military coalitions, for example, there is a need to understand how factors such as communication network topology, trust, cultural differences and the potential for miscommunication affects the ability of distributed teams to generate high quality plans, to formulate effective decisions and to develop shared situation awareness. The current paper presents a computational model and associated simulation capability for performing in silico experimental analyses of collective sensemaking. This model can be used in combination with the results of human experimental studies in order to improve our understanding of the factors that influence collective sensemaking processes.

  4. Computational Models of Relational Processes in Cognitive Development

    Science.gov (United States)

    Halford, Graeme S.; Andrews, Glenda; Wilson, William H.; Phillips, Steven

    2012-01-01

    Acquisition of relational knowledge is a core process in cognitive development. Relational knowledge is dynamic and flexible, entails structure-consistent mappings between representations, has properties of compositionality and systematicity, and depends on binding in working memory. We review three types of computational models relevant to…

  5. A Tutorial Introduction to Bayesian Models of Cognitive Development

    Science.gov (United States)

    Perfors, Amy; Tenenbaum, Joshua B.; Griffiths, Thomas L.; Xu, Fei

    2011-01-01

    We present an introduction to Bayesian inference as it is used in probabilistic models of cognitive development. Our goal is to provide an intuitive and accessible guide to the "what", the "how", and the "why" of the Bayesian approach: what sorts of problems and data the framework is most relevant for, and how and why it may be useful for…

  6. Computational Models of Relational Processes in Cognitive Development

    Science.gov (United States)

    Halford, Graeme S.; Andrews, Glenda; Wilson, William H.; Phillips, Steven

    2012-01-01

    Acquisition of relational knowledge is a core process in cognitive development. Relational knowledge is dynamic and flexible, entails structure-consistent mappings between representations, has properties of compositionality and systematicity, and depends on binding in working memory. We review three types of computational models relevant to…

  7. Building Bridges between Neuroscience, Cognition and Education with Predictive Modeling

    Science.gov (United States)

    Stringer, Steve; Tommerdahl, Jodi

    2015-01-01

    As the field of Mind, Brain, and Education seeks new ways to credibly bridge the gap between neuroscience, the cognitive sciences, and education, various connections are being developed and tested. This article presents a framework and offers examples of one approach, predictive modeling within a virtual educational system that can include…

  8. Dynamical Cognitive Models of Social Issues in Russia

    Science.gov (United States)

    Mitina, Olga; Abraham, Fred; Petrenko, Victor

    We examine and model dynamics in three areas of social cognition: (1) political transformations within Russia, (2) evaluation of political trends in other countries by Russians, and (3) evaluation of Russian stereotypes concerning women. We try to represent consciousness as vectorfields and trajectories in a cognitive state space. We use psychosemantic techniques that allow definition of the state space and the systematic construction of these vectorfields and trajectories and their portrait from research data. Then we construct models to fit them, using multiple regression methods to obtain linear differential equations. These dynamical models of social cognition fit the data quite well. (1) The political transformations were modeled by a spiral repellor in a two-dimensional space of a democratic-totalitarian factor and social depression-optimism factor. (2) The evaluation of alien political trends included a flow away from a saddle toward more stable and moderate political regimes in a 2D space, of democratic-totalitarian and unstable-stable cognitive dimensions. (3) The gender study showed expectations (attractors) for more liberated, emancipated roles for women in the future.

  9. Building Bridges between Neuroscience, Cognition and Education with Predictive Modeling

    Science.gov (United States)

    Stringer, Steve; Tommerdahl, Jodi

    2015-01-01

    As the field of Mind, Brain, and Education seeks new ways to credibly bridge the gap between neuroscience, the cognitive sciences, and education, various connections are being developed and tested. This article presents a framework and offers examples of one approach, predictive modeling within a virtual educational system that can include…

  10. Computational modeling in cognitive science: a manifesto for change.

    Science.gov (United States)

    Addyman, Caspar; French, Robert M

    2012-07-01

    Computational modeling has long been one of the traditional pillars of cognitive science. Unfortunately, the computer models of cognition being developed today have not kept up with the enormous changes that have taken place in computer technology and, especially, in human-computer interfaces.  For all intents and purposes, modeling is still done today as it was 25, or even 35, years ago. Everyone still programs in his or her own favorite programming language, source code is rarely made available, accessibility of models to non-programming researchers is essentially non-existent, and even for other modelers, the profusion of source code in a multitude of programming languages, written without programming guidelines, makes it almost impossible to access, check, explore, re-use, or continue to develop. It is high time to change this situation, especially since the tools are now readily available to do so. We propose that the modeling community adopt three simple guidelines that would ensure that computational models would be accessible to the broad range of researchers in cognitive science. We further emphasize the pivotal role that journal editors must play in making computational models accessible to readers of their journals.

  11. Crafting threads of diblock copolymer micelles via flow-enabled self-assembly.

    Science.gov (United States)

    Li, Bo; Han, Wei; Jiang, Beibei; Lin, Zhiqun

    2014-03-25

    Hierarchically assembled amphiphilic diblock copolymer micelles were exquisitely crafted over large areas by capitalizing on two concurrent self-assembling processes at different length scales, namely, the periodic threads composed of a monolayer or a bilayer of diblock copolymer micelles precisely positioned by flow-enabled self-assembly (FESA) on the microscopic scale and the self-assembly of amphiphilic diblock copolymer micelles into ordered arrays within an individual thread on the nanometer scale. A minimum spacing between two adjacent threads λmin was observed. A model was proposed to rationalize the relationship between the thread width and λmin. Such FESA of diblock copolymer micelles is remarkably controllable and easy to implement. It opens up possibilities for lithography-free positioning and patterning of diblock copolymer micelles for various applications in template fabrication of periodic inorganic nanostructures, nanoelectronics, optoelectronics, magnetic devices, and biotechnology.

  12. Optimizing Cognitive Development over the Life Course and Preventing Cognitive Decline: Introducing the Cognitive Health Environment Life Course Model (CHELM)

    Science.gov (United States)

    Anstey, Kaarin J.

    2014-01-01

    Optimal cognitive development is defined in this article as the highest level of cognitive function reached in each cognitive domain given a person's biological and genetic disposition, and the highest possible maintenance of cognitive function over the adult life course. Theoretical perspectives underpinning the development of a framework…

  13. Optimizing Cognitive Development over the Life Course and Preventing Cognitive Decline: Introducing the Cognitive Health Environment Life Course Model (CHELM)

    Science.gov (United States)

    Anstey, Kaarin J.

    2014-01-01

    Optimal cognitive development is defined in this article as the highest level of cognitive function reached in each cognitive domain given a person's biological and genetic disposition, and the highest possible maintenance of cognitive function over the adult life course. Theoretical perspectives underpinning the development of a framework…

  14. Missing IUD Despite Threads at the Cervix.

    Science.gov (United States)

    Atkinson, Andrew L; Baum, Jonathan D

    2014-01-01

    Today, the intrauterine device (IUD) is by far the most popular form of long term reversible contraception in the world. Side effects from the IUD are minimal and complications are rare. Uterine perforation and migration of the IUD outside the uterine cavity are the most serious complications. Physician visualization and/or the patient feeling retrieval threads at the cervical os are confirmation that the IUD has not been expelled or migrated. We present a case of a perforated, intraperitoneal IUD with threads noted at the cervical os. Office removal was not possible using gentle traction on the threads. Multiple imaging and endoscopic modalities were used to try and locate the IUD including pelvic ultrasound, diagnostic hysteroscopy, cystoscopy, and pelvic magnetic resonance imaging (MRI). The studies gave conflicting results on location of the IUD. Ultimately, the missing IUD was removed via laparoscopy.

  15. OPTIMIZED IMAGE RETRIEVAL SYSTEM USING MULTIPLE THREADS

    Directory of Open Access Journals (Sweden)

    S.P. Jeyapriyamvadha

    2012-05-01

    Full Text Available Content-Based Image Retrieval is a technique used to retrieve similar images where the most challenging aspect is to bridge the gap between low level feature layout and high level semantic concepts. Efficient and effective retrieval techniques of images are desired to work out a certain image on the condition that the result would be more suitable than the input image. A novel method is proposed, which links various images as threads; where the texture features and shape features of the images are extracted and stored. The minimum distance between the query image and the thread provides the output. These threads are based upon the query result. The resultant retrieval system is found to be beneficial and interactive.

  16. Missing IUD Despite Threads at the Cervix

    Directory of Open Access Journals (Sweden)

    Andrew L. Atkinson

    2014-01-01

    Full Text Available Today, the intrauterine device (IUD is by far the most popular form of long term reversible contraception in the world. Side effects from the IUD are minimal and complications are rare. Uterine perforation and migration of the IUD outside the uterine cavity are the most serious complications. Physician visualization and/or the patient feeling retrieval threads at the cervical os are confirmation that the IUD has not been expelled or migrated. We present a case of a perforated, intraperitoneal IUD with threads noted at the cervical os. Office removal was not possible using gentle traction on the threads. Multiple imaging and endoscopic modalities were used to try and locate the IUD including pelvic ultrasound, diagnostic hysteroscopy, cystoscopy, and pelvic magnetic resonance imaging (MRI. The studies gave conflicting results on location of the IUD. Ultimately, the missing IUD was removed via laparoscopy.

  17. Metallic nut for use with ceramic threads

    Science.gov (United States)

    Norton, Paul F.; Shaffer, James E.

    1996-01-01

    A nozzle guide vane assembly has ceramic components therein having a conventional thread thereon including a preestablished pitch and having a preestablished rate of thermal expansion. The nozzle guide vane assembly has a metallic components therein having a preestablished rate of thermal expansion being greater that the rate of thermal expansion of the ceramic components is positioned in a gas turbine engine. The metallic component, a nut, has a thread therein including a plurality of crests being spaced on a pitch equal to that of the ceramic component and has a pair of contacting surfaces extending from the plurality of crests. A notch spirally extends intermediate adjacent ones of the plurality of crests and has a preestablished depth which is at least twice the size of the conventional pitch. Furthermore, the pair of contacting surfaces are in contact with only a portion of the threaded surface of the ceramic components.

  18. Formation and Evolution of a Multi-Threaded Prominence

    Science.gov (United States)

    Luna, M.; Karpen, J. T.; DeVore, C. R.

    2012-01-01

    We investigate the process of formation and subsequent evolution of prominence plasma in a filament channel and its overlying arcade. We construct a three-dimensional time-dependent model of a filament-channel prominence suitable to be compared with observations. We combine this magnetic field structure with one-dimensional independent simulations of many flux tubes. The magnetic structure is a three-dimensional sheared double arcade, and the thermal non-equilibrium process governs the plasma evolution. We have found that the condensations in the corona can be divided into two populations: threads and blobs. Threads are massive condensations that linger in the field line dips. Blobs are ubiquitous small condensations that are produced throughout the filament and overlying arcade magnetic structure, and rapidly fall to the chromosphere. The total prominence mass is in agreement with observations. The threads are the principal contributors to the total mass, whereas the blob contribution is small. The motion of the threads is basically horizontal, while blobs move in all directions along the field. The peak velocities for both populations are comparable, but there is a weak tendency for the velocity to increase with the inclination, and the blobs with motion near vertical have the largest values of the velocity. We have generated synthetic images of the whole structure in an H proxy and in two EUV channels of the AIA instrument aboard SDO. These images show the plasma at cool, warm and hot temperatures. The theoretical differential emission measure of our system agrees very well with observations in the temperature range log T = 4.6-5.7. We conclude that the sheared-arcade magnetic structure and plasma dynamics fit well the abundant observational evidence.

  19. Compliant threads maximize spider silk connection strength and toughness.

    Science.gov (United States)

    Meyer, Avery; Pugno, Nicola M; Cranford, Steven W

    2014-09-06

    Millions of years of evolution have adapted spider webs to achieve a range of functionalities, including the well-known capture of prey, with efficient use of material. One feature that has escaped extensive investigation is the silk-on-silk connection joints within spider webs, particularly from a structural mechanics perspective. We report a joint theoretical and computational analysis of an idealized silk-on-silk fibre junction. By modifying the theory of multiple peeling, we quantitatively compare the performance of the system while systematically increasing the rigidity of the anchor thread, by both scaling the stress-strain response and the introduction of an applied pre-strain. The results of our study indicate that compliance is a virtue-the more extensible the anchorage, the tougher and stronger the connection becomes. In consideration of the theoretical model, in comparison with rigid substrates, a compliant anchorage enormously increases the effective adhesion strength (work required to detach), independent of the adhered thread itself, attributed to a nonlinear alignment between thread and anchor (contact peeling angle). The results can direct novel engineering design principles to achieve possible load transfer from compliant fibre-to-fibre anchorages, be they silk-on-silk or another, as-yet undeveloped, system. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  20. Application of lightweight threading techniques to computational chemistry

    Science.gov (United States)

    Thornley, John; Muller, Richard P.; Mainz, Daniel T.; Çağin, Tahir; Goddard, William A.

    2001-05-01

    The recent advent of inexpensive commodity multiprocessor computers with standardized operating system support for lightweight threads provides computational chemists and other scientists with an exciting opportunity to develop sophisticated new approaches to materials simulation. We contrast the flexible performance characteristics of lightweight threading with the restrictions of traditional scientific supercomputing, based on our experiences with multithreaded molecular dynamics simulation. Motivated by the results of our molecular dynamics experiments, we propose an approach to multi-scale materials simulation using highly dynamic thread creation and synchronization within and between concurrent simulations at many different scales. This approach will enable extremely realistic simulations, with computing resources dynamically directed to areas where they are needed. Multi-scale simulations of this kind require large amounts of processing power, but are too sophisticated to be expressed using traditional supercomputing programming models. As a result, we have developed a high-level programming system called Sthreads that allows highly dynamic, nested multithreaded algorithms to be expressed. Program development is simplified through the use of innovative synchronization operations that allow multithreaded programs to be tested and debugged using standard sequential methods and tools. For this reason, Sthreads is very well suited to the complex multi-scale simulation applications that we are developing.

  1. Cognitive Modeling of Individual Variation in Reference Production and Comprehension.

    Science.gov (United States)

    Hendriks, Petra

    2016-01-01

    A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers' production and listeners' comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions.

  2. Modeling cognitive and emotional processes: a novel neural network architecture.

    Science.gov (United States)

    Khashman, Adnan

    2010-12-01

    In our continuous attempts to model natural intelligence and emotions in machine learning, many research works emerge with different methods that are often driven by engineering concerns and have the common goal of modeling human perception in machines. This paper aims to go further in that direction by investigating the integration of emotion at the structural level of cognitive systems using the novel emotional DuoNeural Network (DuoNN). This network has hidden layer DuoNeurons, where each has two embedded neurons: a dorsal neuron and a ventral neuron for cognitive and emotional data processing, respectively. When input visual stimuli are presented to the DuoNN, the dorsal cognitive neurons process local features while the ventral emotional neurons process the entire pattern. We present the computational model and the learning algorithm of the DuoNN, the input information-cognitive and emotional-parallel streaming method, and a comparison between the DuoNN and a recently developed emotional neural network. Experimental results show that the DuoNN architecture, configuration, and the additional emotional information processing, yield higher recognition rates and faster learning and decision making.

  3. Cognitive Modeling of Individual Variation in Reference Production and Comprehension

    Directory of Open Access Journals (Sweden)

    Petra eHendriks

    2016-04-01

    Full Text Available A challenge for most theoretical and computational accounts of linguistic reference is the observation that language users vary considerably in their referential choices. Part of the variation observed among and within language users and across tasks may be explained from variation in the cognitive resources available to speakers and listeners. This paper presents a computational model of reference production and comprehension developed within the cognitive architecture ACT-R. Through simulations with this ACT-R model, it is investigated how cognitive constraints interact with linguistic constraints and features of the linguistic discourse in speakers’ production and listeners’ comprehension of referring expressions in specific tasks, and how this interaction may give rise to variation in referential choice. The ACT-R model of reference explains and predicts variation among language users in their referential choices as a result of individual and task-related differences in processing speed and working memory capacity. Because of limitations in their cognitive capacities, speakers sometimes underspecify or overspecify their referring expressions, and listeners sometimes choose incorrect referents or are overly liberal in their interpretation of referring expressions.

  4. Improved Fatigue Performance of Threaded Drillstring Connections by Cold Rolling

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, Steinar

    2002-01-01

    The research work presented in this thesis is concerned with analytical, numerical and experimental studies of the effect of cold rolling on the fatigue behaviour of threaded drillstring connections. A comprehensive literature study is made of the various effects on the fatigue behaviour of residual stresses introduced by mechanical deformation of notched components. Some of the effects studied are cyclic hardening behaviour after prestraining, cyclic creep, fatigue initiation in prestrained materials, short cracks and crack growth models including crack closure. Residual stresses were introduced in the surface of a smooth pipe by a rolling device to simulate a cold rolling process and verify the calculated residual stresses by measurements. Strain hardening and contact algorithm of the two bodies were incorporated in the FE analyses. Two significant errors were found in the commercial software package for residual stress evaluation, Restran v. 3.3.2a also called SINT, when using the Schajer method. The Schajer algorithm is the only hole-drilling algorithm without theoretical shortcomings, and is recommended when measuring large residual stress gradients in the depth direction. Using the Schajer method solved by in-house Matlab-routines good agreement between measured residual stress gradients and residual stress gradients from FE analyses was found. Full scale fatigue tests were performed on pipes cut from used drillstrings with notches of similar geometry as threads used in drillstring connections. The simulated threads consisted of four full depth helix notches with runouts at the surface. The pipe threads were cold rolled and fatigue tested in a full-scale four-point rotating bending fatigue testing rig. The test results showed that cold rolling had an effect on the crack initiation period. A major part of the fatigue life was with cracks observed at the notch root, but due to the increased fatigue crack propagation resistance the final fracture initiated at

  5. Cognitive Modeling at ICCM: State of the Art and Future Directions.

    Science.gov (United States)

    Taatgen, Niels A; van Vugt, Marieke K; Borst, Jelmer P; Mehlhorn, Katja

    2016-01-01

    The goal of cognitive modeling is to build faithful simulations of human cognition. One of the challenges is that multiple models can often explain the same phenomena. Another challenge is that models are often very hard to understand, explore, and reuse by others. We discuss some of the solutions that were discussed during the 2015 International Conference on Cognitive Modeling.

  6. A cognitive model for software architecture complexity

    NARCIS (Netherlands)

    Bouwers, E.; Lilienthal, C.; Visser, J.; Van Deursen, A.

    2010-01-01

    Evaluating the complexity of the architecture of a softwaresystem is a difficult task. Many aspects have to be considered to come to a balanced assessment. Several architecture evaluation methods have been proposed, but very few define a quality model to be used during the evaluation process. In add

  7. Extending Social Cognition Models of Health Behaviour

    Science.gov (United States)

    Abraham, Charles; Sheeran, Paschal; Henderson, Marion

    2011-01-01

    A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…

  8. Extending Social Cognition Models of Health Behaviour

    Science.gov (United States)

    Abraham, Charles; Sheeran, Paschal; Henderson, Marion

    2011-01-01

    A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…

  9. Cognitive rehabilitation reduces cognitive impairment and normalizes hippocampal CA1 architecture in a rat model of vascular dementia

    OpenAIRE

    Langdon, Kristopher D.; Granter-Button, Shirley; Carolyn W Harley; Moody-Corbett, Frances; Peeling, James; Corbett, Dale

    2013-01-01

    Dementia is a major cause of morbidity in the western society. Pharmacological therapies to delay the progression of cognitive impairments are modestly successful. Consequently, new therapies are urgently required to improve cognitive deficits associated with dementia. We evaluated the effects of physical and cognitive activity on learning and memory in a rat model of vascular dementia (VasD). Male Sprague-Dawley rats (6 months old) were exposed to either regular chow or a diet rich in satura...

  10. Defining a Family of Cognitive Diagnosis Models Using Log-Linear Models with Latent Variables

    Science.gov (United States)

    Henson, Robert A.; Templin, Jonathan L.; Willse, John T.

    2009-01-01

    This paper uses log-linear models with latent variables (Hagenaars, in "Loglinear Models with Latent Variables," 1993) to define a family of cognitive diagnosis models. In doing so, the relationship between many common models is explicitly defined and discussed. In addition, because the log-linear model with latent variables is a general model for…

  11. A Model for Cognitive Process of Neologisms Translation

    Directory of Open Access Journals (Sweden)

    Seyed Mohammad Moghadas

    2014-03-01

    Full Text Available Over the past three decades Process-oriented Descriptive Translation Studies has developed noticeably. Think-aloud protocols (TAPs, as a verbal report, are still the most applied empirical method to investigate the complex and conscious processes of translator’s mind during translating. This article deals with the cognitive process of professional translators’ problem-solving to translate a neologism from English source text into Persian by using TAPs. Likewise, the researcher has also used the means of video recording to observe the other behaviors of participants during the problem solving. The results indicate that the professional translators do not use one single way of performing a translation task and the complexity of the process of problem-solving (neologisms translation depends on the translation competence of translators. Finally, the researcher has also presented a cognitive model for the translation process of neologisms in ideal situations. As the translation universals are cognitive phenomena, the cognitive model presented here can be a pattern for trainee translators in education to visualize the natural process of neologism translation.

  12. Hierarchical Heteroclinics in Dynamical Model of Cognitive Processes: Chunking

    Science.gov (United States)

    Afraimovich, Valentin S.; Young, Todd R.; Rabinovich, Mikhail I.

    Combining the results of brain imaging and nonlinear dynamics provides a new hierarchical vision of brain network functionality that is helpful in understanding the relationship of the network to different mental tasks. Using these ideas it is possible to build adequate models for the description and prediction of different cognitive activities in which the number of variables is usually small enough for analysis. The dynamical images of different mental processes depend on their temporal organization and, as a rule, cannot be just simple attractors since cognition is characterized by transient dynamics. The mathematical image for a robust transient is a stable heteroclinic channel consisting of a chain of saddles connected by unstable separatrices. We focus here on hierarchical chunking dynamics that can represent several cognitive activities. Chunking is the dynamical phenomenon that means dividing a long information chain into shorter items. Chunking is known to be important in many processes of perception, learning, memory and cognition. We prove that in the phase space of the model that describes chunking there exists a new mathematical object — heteroclinic sequence of heteroclinic cycles — using the technique of slow-fast approximations. This new object serves as a skeleton of motions reflecting sequential features of hierarchical chunking dynamics and is an adequate image of the chunking processing.

  13. Agent-based cognitive model for human resources competence management.

    Science.gov (United States)

    Oliveira, Stefan; Gluz, João Carlos

    2010-01-01

    This chapter presents an agent-based cognitive model aimed to represent human competency concepts and competence management processes of psychological nature. This model is implemented by a multiagent system application intended to help managers of software development projects to select, based on the competence management model, the right professionals to integrate a development team. There are several software engineering methodologies that can be used to design and develop multiagent systems. However, due to the necessity to handle human competency concepts of cognitive nature, like aptitudes, interests, abilities and knowledge, we were driven to choose methodologies that can handle these concepts since the inception of the system. To do so, we integrated the TROPOS methodology, and a set of software engineering methods derived from intelligent tutoring systems research to successfully analyze and design the proposed system. At the end of the paper we present a study case, showing how the proposed system should be applied to the domain of website development.

  14. Conceptual Commitments of the LIDA Model of Cognition

    Science.gov (United States)

    Franklin, Stan; Strain, Steve; McCall, Ryan; Baars, Bernard

    2013-06-01

    Significant debate on fundamental issues remains in the subfields of cognitive science, including perception, memory, attention, action selection, learning, and others. Psychology, neuroscience, and artificial intelligence each contribute alternative and sometimes conflicting perspectives on the supervening problem of artificial general intelligence (AGI). Current efforts toward a broad-based, systems-level model of minds cannot await theoretical convergence in each of the relevant subfields. Such work therefore requires the formulation of tentative hypotheses, based on current knowledge, that serve to connect cognitive functions into a theoretical framework for the study of the mind. We term such hypotheses "conceptual commitments" and describe the hypotheses underlying one such model, the Learning Intelligent Distribution Agent (LIDA) Model. Our intention is to initiate a discussion among AGI researchers about which conceptual commitments are essential, or particularly useful, toward creating AGI agents.

  15. Robot Cognitive Control with a Neurophysiologically Inspired Reinforcement Learning Model

    Science.gov (United States)

    Khamassi, Mehdi; Lallée, Stéphane; Enel, Pierre; Procyk, Emmanuel; Dominey, Peter F.

    2011-01-01

    A major challenge in modern robotics is to liberate robots from controlled industrial settings, and allow them to interact with humans and changing environments in the real-world. The current research attempts to determine if a neurophysiologically motivated model of cortical function in the primate can help to address this challenge. Primates are endowed with cognitive systems that allow them to maximize the feedback from their environment by learning the values of actions in diverse situations and by adjusting their behavioral parameters (i.e., cognitive control) to accommodate unexpected events. In such contexts uncertainty can arise from at least two distinct sources – expected uncertainty resulting from noise during sensory-motor interaction in a known context, and unexpected uncertainty resulting from the changing probabilistic structure of the environment. However, it is not clear how neurophysiological mechanisms of reinforcement learning and cognitive control integrate in the brain to produce efficient behavior. Based on primate neuroanatomy and neurophysiology, we propose a novel computational model for the interaction between lateral prefrontal and anterior cingulate cortex reconciling previous models dedicated to these two functions. We deployed the model in two robots and demonstrate that, based on adaptive regulation of a meta-parameter β that controls the exploration rate, the model can robustly deal with the two kinds of uncertainties in the real-world. In addition the model could reproduce monkey behavioral performance and neurophysiological data in two problem-solving tasks. A last experiment extends this to human–robot interaction with the iCub humanoid, and novel sources of uncertainty corresponding to “cheating” by the human. The combined results provide concrete evidence for the ability of neurophysiologically inspired cognitive systems to control advanced robots in the real-world. PMID:21808619

  16. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, Dusko; Hilderink, Gerald H.; Broenink, Jan F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the so

  17. Software mechanics for Java multi-threading

    NARCIS (Netherlands)

    Bergstra, J.A.; Loots, M.E.

    For a subset JavaTck (Java Thread Composition Kernel) of Java an empirical semantics has been developed. Special emphasis is put on the role of synchronization features. The validity of empirical semantics is discussed in the light of a number of compiler postulates. A translation of process

  18. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the so

  19. A communicating Thread -CT- case study: JIWY

    NARCIS (Netherlands)

    Jovanovic, D.S.; Hilderink, G.H.; Broenink, Johannes F.; Pascoe, P.W.J.; Loader, R.; Sunderman, V.

    2002-01-01

    This JIWY demonstrator is constructed in the context of the development of a design framework and software tools to efficiently support mechatronic engineers in developing sophisticated control computer code out of a set control laws. We use the CSP-based Communicating Threads -CT- library as the

  20. Software mechanics for Java multi-threading

    OpenAIRE

    Bergstra, J. A.; Loots, M.E.

    1999-01-01

    For a subset JavaTck (Java Thread Composition Kernel) of Java an empirical semantics has been developed. Special emphasis is put on the role of synchronization features. The validity of empirical semantics is discussed in the light of a number of compiler postulates. A translation of process algebra with conditions and free merge to Java is used as an example.

  1. Acquiring neural signals for developing a perception and cognition model

    Science.gov (United States)

    Li, Wei; Li, Yunyi; Chen, Genshe; Shen, Dan; Blasch, Erik; Pham, Khanh; Lynch, Robert

    2012-06-01

    The understanding of how humans process information, determine salience, and combine seemingly unrelated information is essential to automated processing of large amounts of information that is partially relevant, or of unknown relevance. Recent neurological science research in human perception, and in information science regarding contextbased modeling, provides us with a theoretical basis for using a bottom-up approach for automating the management of large amounts of information in ways directly useful for human operators. However, integration of human intelligence into a game theoretic framework for dynamic and adaptive decision support needs a perception and cognition model. For the purpose of cognitive modeling, we present a brain-computer-interface (BCI) based humanoid robot system to acquire brainwaves during human mental activities of imagining a humanoid robot-walking behavior. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model. The BCI system consists of a data acquisition unit with an electroencephalograph (EEG), a humanoid robot, and a charge couple CCD camera. An EEG electrode cup acquires brainwaves from the skin surface on scalp. The humanoid robot has 20 degrees of freedom (DOFs); 12 DOFs located on hips, knees, and ankles for humanoid robot walking, 6 DOFs on shoulders and arms for arms motion, and 2 DOFs for head yaw and pitch motion. The CCD camera takes video clips of the human subject's hand postures to identify mental activities that are correlated to the robot-walking behaviors. We use the neural signals to investigate relationships between complex humanoid robot behaviors and human mental activities for developing the perception and cognition model.

  2. Lateral specialization in unilateral spatial neglect: a cognitive robotics model.

    Science.gov (United States)

    Conti, Daniela; Di Nuovo, Santo; Cangelosi, Angelo; Di Nuovo, Alessandro

    2016-08-01

    In this paper, we present the experimental results of an embodied cognitive robotic approach for modelling the human cognitive deficit known as unilateral spatial neglect (USN). To this end, we introduce an artificial neural network architecture designed and trained to control the spatial attentional focus of the iCub robotic platform. Like the human brain, the architecture is divided into two hemispheres and it incorporates bio-inspired plasticity mechanisms, which allow the development of the phenomenon of the specialization of the right hemisphere for spatial attention. In this study, we validate the model by replicating a previous experiment with human patients affected by the USN and numerical results show that the robot mimics the behaviours previously exhibited by humans. We also simulated recovery after the damage to compare the performance of each of the two hemispheres as additional validation of the model. Finally, we highlight some possible advantages of modelling cognitive dysfunctions of the human brain by means of robotic platforms, which can supplement traditional approaches for studying spatial impairments in humans.

  3. Machine Cognition Models: EPAM and GPS

    CERN Document Server

    Elouafiq, Ali

    2012-01-01

    Through history, the human being tried to relay its daily tasks to other creatures, which was the main reason behind the rise of civilizations. It started with deploying animals to automate tasks in the field of agriculture(bulls), transportation (e.g. horses and donkeys), and even communication (pigeons). Millenniums after, come the Golden age with "Al-jazari" and other Muslim inventors, which were the pioneers of automation, this has given birth to industrial revolution in Europe, centuries after. At the end of the nineteenth century, a new era was to begin, the computational era, the most advanced technological and scientific development that is driving the mankind and the reason behind all the evolutions of science; such as medicine, communication, education, and physics. At this edge of technology engineers and scientists are trying to model a machine that behaves the same as they do, which pushed us to think about designing and implementing "Things that-Thinks", then artificial intelligence was. In this...

  4. Silicon Carbide Threads For High-Temperature Service

    Science.gov (United States)

    Sawko, Paul M.; Vasudev, Anand

    1991-01-01

    New thread material outperforms silica. Sewing threads containing silicon carbide (SiC) yarn withstand temperatures of more than 1,100 degrees C. Intended for use in stitching thermally insulating blankets.

  5. Type Safe Nondeterminism - A formal Semantics of Java Threads

    OpenAIRE

    Lochbihler, Andreas

    2008-01-01

    We present a generic framework to transform a single-threaded operational semantics into a semantics with interleaved execution of threads. Threads can be dynamically created and use locks for synchronisation. They can suspend themselves, be notified by other threads again, and interact via shared memory. We formalised this in the proof assistant Isabelle/HOL along with theorems to carry type safety proofs for the instantiating semantics (progress and preservation in the style of Wright and F...

  6. Modeling media as latent semantics based on cognitive components

    DEFF Research Database (Denmark)

    Petersen, Michael Kai

    dimensionality. While top-down, patterns of emotional categorization emerge by defining term vector distances to affective adjectives, that constrain the latent semantic structures according to the neurophysiological dimensions of valence and arousal. The thesis thus combines elements of machine learning...... with aspects of cognitive linguistics that potentially could be utilized in applications ranging from information retrieval and media personalization, to emotional brand building or neuroscientific modeling of syntax and semantics....

  7. Cognition and procedure representational requirements for predictive human performance models

    Science.gov (United States)

    Corker, K.

    1992-01-01

    Models and modeling environments for human performance are becoming significant contributors to early system design and analysis procedures. Issues of levels of automation, physical environment, informational environment, and manning requirements are being addressed by such man/machine analysis systems. The research reported here investigates the close interaction between models of human cognition and models that described procedural performance. We describe a methodology for the decomposition of aircrew procedures that supports interaction with models of cognition on the basis of procedures observed; that serves to identify cockpit/avionics information sources and crew information requirements; and that provides the structure to support methods for function allocation among crew and aiding systems. Our approach is to develop an object-oriented, modular, executable software representation of the aircrew, the aircraft, and the procedures necessary to satisfy flight-phase goals. We then encode in a time-based language, taxonomies of the conceptual, relational, and procedural constraints among the cockpit avionics and control system and the aircrew. We have designed and implemented a goals/procedures hierarchic representation sufficient to describe procedural flow in the cockpit. We then execute the procedural representation in simulation software and calculate the values of the flight instruments, aircraft state variables and crew resources using the constraints available from the relationship taxonomies. The system provides a flexible, extensible, manipulative and executable representation of aircrew and procedures that is generally applicable to crew/procedure task-analysis. The representation supports developed methods of intent inference, and is extensible to include issues of information requirements and functional allocation. We are attempting to link the procedural representation to models of cognitive functions to establish several intent inference methods

  8. Quantum transport of vortices in a weakly dissipative ring threaded by an Aharonov-Casher flux: A tight-binding model

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, J. [Texas Center for Superconductivity, University of Houston, Houston, Texas 77204-5932 (United States)]|[Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Wang, Z.D. [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong)

    1997-11-01

    Based on the tight-binding model and taking into account the effect of dissipation as well as the disorder, we study quantum interference via the Aharonov-Casher effect for fluxons in a ring-shaped superconductor. The electrical resistance in terms of the transmission probability for a quantum vortex to traverse the ring is calculated. It is shown that a quantum interference effect is exhibited in the resistance in the presence of weak dissipation. Our analysis may also be applied to a Josephson-junction array system. In particular, by including the disorder effect, we are able to explain the experimental measurements in the dissipative regime done by Elion {ital et al.} [Phys. Rev. Lett. {bold 71}, 2311 (1993)]. {copyright} {ital 1997} {ital The American Physical Society}

  9. Does the cognitive reflection test measure cognitive reflection? A mathematical modeling approach.

    Science.gov (United States)

    Campitelli, Guillermo; Gerrans, Paul

    2014-04-01

    We used a mathematical modeling approach, based on a sample of 2,019 participants, to better understand what the cognitive reflection test (CRT; Frederick In Journal of Economic Perspectives, 19, 25-42, 2005) measures. This test, which is typically completed in less than 10 min, contains three problems and aims to measure the ability or disposition to resist reporting the response that first comes to mind. However, since the test contains three mathematically based problems, it is possible that the test only measures mathematical abilities, and not cognitive reflection. We found that the models that included an inhibition parameter (i.e., the probability of inhibiting an intuitive response), as well as a mathematical parameter (i.e., the probability of using an adequate mathematical procedure), fitted the data better than a model that only included a mathematical parameter. We also found that the inhibition parameter in males is best explained by both rational thinking ability and the disposition toward actively open-minded thinking, whereas in females this parameter was better explained by rational thinking only. With these findings, this study contributes to the understanding of the processes involved in solving the CRT, and will be particularly useful for researchers who are considering using this test in their research.

  10. Exploring the cognitive and motor functions of the basal ganglia: An integrative review of computational cognitive neuroscience models

    Directory of Open Access Journals (Sweden)

    Sebastien eHelie

    2013-12-01

    Full Text Available Many computational models of the basal ganglia have been proposed over the past twenty-five years. While computational neuroscience models have focused on closely matching the neurobiology of the basal ganglia, computational cognitive neuroscience models have focused on how the basal ganglia can be used to implement cognitive and motor functions. This review article focuses on computational cognitive neuroscience models of the basal ganglia and how they use the neuroanatomy of the basal ganglia to account for cognitive and motor functions such as categorization, instrumental conditioning, probabilistic learning, working memory, sequence learning, automaticity, reaching, handwriting, and eye saccades. A total of 19 basal ganglia models accounting for one or more of these functions are reviewed and compared. The review concludes with a discussion of the limitations of existing computational cognitive neuroscience models of the basal ganglia and prescriptions for future modeling, including the need for computational models of the basal ganglia that can simultaneously account for cognitive and motor functions, and the need for a more complete specification of the role of the basal ganglia in behavioral functions.

  11. Applying the Cognitive Vulnerability Model to the analysis of cognitive and family influences on children's dental fear.

    Science.gov (United States)

    Crego, Antonio; Carrillo-Diaz, Maria; Armfield, Jason M; Romero, Martin

    2013-06-01

    Negative experiences, cognitions, and family variables are involved in the etiology of child dental fear, but previous research has frequently considered them separately. This study uses the Cognitive Vulnerability Model to explore the influence of negative dental experiences and family members on children's dental anxiety. The participants were 185 children who completed a questionnaire comprising measures of dental fear and cognitive vulnerability-related perceptions. Measures were obtained for 88 of the participants' fathers and for 97 of the participants' mothers. Cognitive vulnerability perceptions had the strongest association with children's dental fear (β = 0.40), explaining 14-21% of the variance in dental fear scores beyond that explained by other variables. Furthermore, vulnerability perceptions mediated the relationship between negative dental experiences and dental fear. Children's dental fear and cognitive vulnerability perceptions were significantly associated with those of their fathers (r = 0.23 and r = 0.40, respectively) and mothers (r = 0.28 and r = 0.35, respectively). Moreover, fathers' (β = 0.24) and mothers' (β = 0.31) levels of cognitive vulnerability significantly predicted the children's levels of dental fear. The Cognitive Vulnerability Model offers a framework to understand child dental fear. Furthermore, this cognitive approach may help explain why some children develop dental fear problems after suffering a negative dental experience and how dental anxiety is passed on from parents to children.

  12. Relationship Marketing results: proposition of a cognitive mapping model

    Directory of Open Access Journals (Sweden)

    Iná Futino Barreto

    2015-12-01

    Full Text Available Objective - This research sought to develop a cognitive model that expresses how marketing professionals understand the relationship between the constructs that define relationship marketing (RM. It also tried to understand, using the obtained model, how objectives in this field are achieved. Design/methodology/approach – Through cognitive mapping, we traced 35 individual mental maps, highlighting how each respondent understands the interactions between RM elements. Based on the views of these individuals, we established an aggregate mental map. Theoretical foundation – The topic is based on a literature review that explores the RM concept and its main elements. Based on this review, we listed eleven main constructs. Findings – We established an aggregate mental map that represents the RM structural model. Model analysis identified that CLV is understood as the final result of RM. We also observed that the impact of most of the RM elements on CLV is brokered by loyalty. Personalization and quality, on the other hand, proved to be process input elements, and are the ones that most strongly impact others. Finally, we highlight that elements that punish customers are much less effective than elements that benefit them. Contributions - The model was able to insert core elements of RM, but absent from most formal models: CLV and customization. The analysis allowed us to understand the interactions between the RM elements and how the end result of RM (CLV is formed. This understanding improves knowledge on the subject and helps guide, assess and correct actions.

  13. Calculus for cognitive scientists derivatives, integrals and models

    CERN Document Server

    Peterson, James K

    2016-01-01

    This book provides a self-study program on how mathematics, computer science and science can be usefully and seamlessly intertwined. Learning to use ideas from mathematics and computation is essential for understanding approaches to cognitive and biological science. As such the book covers calculus on one variable and two variables and works through a number of interesting first-order ODE models. It clearly uses MatLab in computational exercises where the models cannot be solved by hand, and also helps readers to understand that approximations cause errors – a fact that must always be kept in mind.

  14. Analysis of Grinding Force and Elastic Deformation in Thread Grinding Process

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2013-01-01

    Full Text Available Considering the grinding geometry of the thread grinding dynamic contact arc length, a dynamic numerical thread grinding model has been set up on the basis of study of a single grit grinding model. The properties of grinding force and dynamic contact arc-length have been studied by means of the developed numerical model. The results have shown that the angle of helix has little effect on the dynamic contact arc-length than the wheel speed on the dynamic contact arc-length. And the wheel speed also produced a large effect on grinding force.

  15. Improved Fatigue Performance of Threaded Drillstring Connections by Cold Rolling

    Energy Technology Data Exchange (ETDEWEB)

    Kristoffersen, Steinar

    2002-01-01

    The research work presented in this thesis is concerned with analytical, numerical and experimental studies of the effect of cold rolling on the fatigue behaviour of threaded drillstring connections. A comprehensive literature study is made of the various effects on the fatigue behaviour of residual stresses introduced by mechanical deformation of notched components. Some of the effects studied are cyclic hardening behaviour after prestraining, cyclic creep, fatigue initiation in prestrained materials, short cracks and crack growth models including crack closure. Residual stresses were introduced in the surface of a smooth pipe by a rolling device to simulate a cold rolling process and verify the calculated residual stresses by measurements. Strain hardening and contact algorithm of the two bodies were incorporated in the FE analyses. Two significant errors were found in the commercial software package for residual stress evaluation, Restran v. 3.3.2a also called SINT, when using the Schajer method. The Schajer algorithm is the only hole-drilling algorithm without theoretical shortcomings, and is recommended when measuring large residual stress gradients in the depth direction. Using the Schajer method solved by in-house Matlab-routines good agreement between measured residual stress gradients and residual stress gradients from FE analyses was found. Full scale fatigue tests were performed on pipes cut from used drillstrings with notches of similar geometry as threads used in drillstring connections. The simulated threads consisted of four full depth helix notches with runouts at the surface. The pipe threads were cold rolled and fatigue tested in a full-scale four-point rotating bending fatigue testing rig. The test results showed that cold rolling had an effect on the crack initiation period. A major part of the fatigue life was with cracks observed at the notch root, but due to the increased fatigue crack propagation resistance the final fracture initiated at

  16. Genetic spectrum assignment model with constraints in cognitive radio networks

    Directory of Open Access Journals (Sweden)

    Fang Ye

    2011-06-01

    Full Text Available The interference constraints of genetic spectrum assignment model in cognitive radio networks are analyzed in this paper. An improved genetic spectrum assignment model is proposed. The population of genetic algorithm is divided into two sets, the feasible spectrum assignment strategies and the randomly updated spectrum assignment strategies. The penalty function is added to the utility function to achieve the spectrum assignment strategy that satisfies the interference constraints and has better fitness. The proposed method is applicable in both the genetic spectrum assignment model and the quantum genetic spectrum assignment mode. It can ensure the randomness of partial chromosomes in the population to some extent, and reduce the computational complexity caused by the constraints-free procedure after the update of population. Simulation results show that the proposed method can achieve better performance than the conventional genetic spectrum assignment model and quantum genetic spectrum assignment model

  17. Modeling the situation awareness by the analysis of cognitive process.

    Science.gov (United States)

    Liu, Shuang; Wanyan, Xiaoru; Zhuang, Damin

    2014-01-01

    To predict changes of situation awareness (SA) for pilot operating with different display interfaces and tasks, a qualitative analysis and quantitative calculation joint SA model was proposed. Based on the situational awareness model according to the attention allocation built previously, the pilot cognitive process for the situation elements was analyzed according to the ACT-R (Adaptive Control of Thought, Rational) theory, which explained how the SA was produced. To verify the validity of this model, 28 subjects performed an instrument supervision task under different experiment conditions. Situation Awareness Global Assessment Technique (SAGAT), 10-dimensional Situational Awareness Rating Technique (10-D SART), performance measure and eye movement measure were adopted for evaluating SAs under different conditions. Statistical analysis demonstrated that the changing trend of SA calculated by this model was highly correlated with the experimental results. Therefore the situational awareness model can provide a reference for designing new cockpit display interfaces and help reducing human errors.

  18. Use of barbed threads in facial rejuvenation

    Directory of Open Access Journals (Sweden)

    Kalra Rakesh

    2008-10-01

    Full Text Available Use of barbed threads, available with uni- and bi-directional cogs or barbs, is a semi-invasive method of lifting sagging skin of the face. Areas treated with this method include the eyebrows, the cheeks, the jowls and the neck. Ease of use and a shorter down-time have made their use popular. Specific indications, operative procedures, risks and complications are described and some clinical results of the author shown.

  19. Development of threads's applications in Java

    OpenAIRE

    ATTL, Karel

    2008-01-01

    This diploma thesis is aimed at programming of multithreaded applications in Java. With Java 5 comes package java.util.concurrent, which in an important way makes developing of parallel applications easier and more effective. This work is conceived as an introduction to programming of multithreaded applications in Java and could be also used as an educational material. Theoretical introduction about processes and technological background of multitasking gives analogy to threads, at the same t...

  20. Development of threads's applications in Java

    OpenAIRE

    ATTL, Karel

    2008-01-01

    This diploma thesis is aimed at programming of multithreaded applications in Java. With Java 5 comes package java.util.concurrent, which in an important way makes developing of parallel applications easier and more effective. This work is conceived as an introduction to programming of multithreaded applications in Java and could be also used as an educational material. Theoretical introduction about processes and technological background of multitasking gives analogy to threads, at the same t...

  1. Discovering High-Quality Threaded Discussions in Online Forums

    Institute of Scientific and Technical Information of China (English)

    Jung-Tae Lee; Min-Chul Yang; Hae-Chang Rim

    2014-01-01

    Archives of threaded discussions generated by users in online forums and discussion boards contain valuable knowledge on various topics. However, not all threads are useful because of deliberate abuses, such as trolling and flaming, that are commonly observed in online conversations. The existence of various users with different levels of expertise also makes it difficult to assume that every discussion thread stored online contains high-quality contents. Although finding high-quality threads automatically can help both users and search engines sift through a huge amount of thread archives and make use of these potentially useful resources effectively, no previous work to our knowledge has performed a study on such task. In this paper, we propose an automatic method for distinguishing high-quality threads from low-quality ones in online discussion sites. We first suggest four different artificial measures for inducing overall quality of a thread based on ratings of its posts. We then propose two tasks involving prediction of thread quality without using post rating information. We adopt a popular machine learning framework to solve the two prediction tasks. Experimental results on a real world forum archive demonstrate that our method can significantly improve the prediction performance across all four measures of thread quality on both tasks. We also compare how different types of features derived from various aspects of threads contribute to the overall performance and investigate key features that play a crucial role in discovering high-quality threads in online discussion sites.

  2. Performance Study and Dynamic Optimization Design for Thread Pool Systems

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Dongping [Iowa State Univ., Ames, IA (United States)

    2004-12-19

    Thread pools have been widely used by many multithreaded applications. However, the determination of the pool size according to the application behavior still remains problematic. To automate this process, in this thesis we have developed a set of performance metrics for quantitatively analyzing thread pool performance. For our experiments, we built a thread pool system which provides a general framework for thread pool research. Based on this simulation environment, we studied the performance impact brought by the thread pool on different multithreaded applications. Additionally, the correlations between internal characterizations of thread pools and their throughput were also examined. We then proposed and evaluated a heuristic algorithm to dynamically determine the optimal thread pool size. The simulation results show that this approach is effective in improving overall application performance.

  3. August Knoblauch and amusia: a nineteenth-century cognitive model of music.

    Science.gov (United States)

    Johnson, Julene K; Graziano, Amy B

    2003-02-01

    Early models of human cognition can be traced to nineteenth-century investigations of brain and behavior. Influential neurologists such as Wernicke, Kussmaul, and Lichtheim constructed diagrammatic models to illustrate current theories of cognition. Language was the most commonly studied cognitive function during this time; however, investigators also studied other cognitive functions, such as music and visual processing. While a number of nineteenth-century neurologists made observations about music abilities in aphasic patients, August Knoblauch, a German physician and anatomist, was the first to propose a diagrammatic model of music (1888/1890). He described a detailed cognitive model of music processing, hypothesized the existence of nine disorders of music production and perception, and coined the term "amusia." Knoblauch's model is the earliest cognitive model of music and is largely unrecognized as an important part of the history of neurology, neuropsychology, and music cognition. Copyright 2003 Elsevier Science (USA)

  4. Cholinergic modulation of cognitive processing: insights drawn from computational models

    Directory of Open Access Journals (Sweden)

    Ehren L Newman

    2012-06-01

    Full Text Available Acetylcholine plays an important role in cognitive function, as shown by pharmacological manipulations that impact working memory, attention, episodic memory and spatial memory function. Acetylcholine also shows striking modulatory influences on the cellular physiology of hippocampal and cortical neurons. Modeling of neural circuits provides a framework for understanding how the cognitive functions may arise from the influence of acetylcholine on neural and network dynamics. We review the influences of cholinergic manipulations on behavioral performance in working memory, attention, episodic memory and spatial memory tasks, the physiological effects of acetylcholine on neural and circuit dynamics, and the computational models that provide insight into the functional relationships between the physiology and behavior. Specifically, we discuss the important role of acetylcholine in governing mechanisms of active maintenance in working memory tasks and in regulating network dynamics important for effective processing of stimuli in attention and episodic memory tasks. We also propose that theta rhythm play a crucial role as an intermediary between the physiological influences of acetylcholine and behavior in episodic and spatial memory tasks. We conclude with a synthesis of the existing modeling work and highlight future directions that are likely to be rewarding given the existing state of the literature for both empiricists and modelers.

  5. Cognitive load and modelling of an algebra problem

    Science.gov (United States)

    Chinnappan, Mohan

    2010-09-01

    In the present study, I examine a modelling strategy as employed by a teacher in the context of an algebra lesson. The actions of this teacher suggest that a modelling approach will have a greater impact on enriching student learning if we do not lose sight of the need to manage associated cognitive loads that could either aid or hinder the integration of core concepts with processes that are at play. Results here also show that modelling a problem that is set within an authentic context helps learners develop a better appreciation of variables and relations that constitute the model. The teacher's scaffolding actions revealed the use of strategies that foster the development of connected, meaningful and more useable algebraic knowledge.

  6. Imaging a cognitive model of apraxia: the neural substrate of gesture-specific cognitive processes.

    Science.gov (United States)

    Peigneux, Philippe; Van der Linden, Martial; Garraux, Gaetan; Laureys, Steven; Degueldre, Christian; Aerts, Joel; Del Fiore, Guy; Moonen, Gustave; Luxen, Andre; Salmon, Eric

    2004-03-01

    The present study aimed to ascertain the neuroanatomical basis of an influential neuropsychological model for upper limb apraxia [Rothi LJ, et al. The Neuropsychology of Action. 1997. Hove, UK: Psychology Press]. Regional cerebral blood flow was measured in healthy volunteers using H2 15O PET during performance of four tasks commonly used for testing upper limb apraxia, i.e., pantomime of familiar gestures on verbal command, imitation of familiar gestures, imitation of novel gestures, and an action-semantic task that consisted in matching objects for functional use. We also re-analysed data from a previous PET study in which we investigated the neural basis of the visual analysis of gestures. First, we found that two sets of discrete brain areas are predominantly engaged in the imitation of familiar and novel gestures, respectively. Segregated brain activation for novel gesture imitation concur with neuropsychological reports to support the hypothesis that knowledge about the organization of the human body mediates the transition from visual perception to motor execution when imitating novel gestures [Goldenberg Neuropsychologia 1995;33:63-72]. Second, conjunction analyses revealed distinctive neural bases for most of the gesture-specific cognitive processes proposed in this cognitive model of upper limb apraxia. However, a functional analysis of brain imaging data suggested that one single memory store may be used for "to-be-perceived" and "to-be-produced" gestural representations, departing from Rothi et al.'s proposal. Based on the above considerations, we suggest and discuss a revised model for upper limb apraxia that might best account for both brain imaging findings and neuropsychological dissociations reported in the apraxia literature. Copyright 2004 Wiley-Liss, Inc.

  7. Cognitive rehabilitation reduces cognitive impairment and normalizes hippocampal CA1 architecture in a rat model of vascular dementia.

    Science.gov (United States)

    Langdon, Kristopher D; Granter-Button, Shirley; Harley, Carolyn W; Moody-Corbett, Frances; Peeling, James; Corbett, Dale

    2013-06-01

    Dementia is a major cause of morbidity in the western society. Pharmacological therapies to delay the progression of cognitive impairments are modestly successful. Consequently, new therapies are urgently required to improve cognitive deficits associated with dementia. We evaluated the effects of physical and cognitive activity on learning and memory in a rat model of vascular dementia (VasD). Male Sprague-Dawley rats (6 months old) were exposed to either regular chow or a diet rich in saturated fats and sucrose and chronic bilateral common carotid artery occlusion or sham surgery. First, this model of VasD was validated using a 2 × 2 experimental design (surgery × diet) and standard cognitive outcomes. Next, using identical surgical procedures, we exposed animals to a paradigm of cognitive rehabilitation or a sedentary condition. At 16 weeks post surgery, VasD animals demonstrated significant learning and memory deficits in the Morris water maze, independent of diet. Rehabilitation significantly attenuated these cognitive deficits at this time point as well as at 24 weeks. Further, rehabilitation normalized hippocampal CA1 soma size (area and volume) to that of control animals, independent of cell number. Importantly, these findings demonstrate beneficial neuroplasticity in early middle-aged rats that promoted cognitive recovery, an area rarely explored in preclinical studies.

  8. Using data-driven model-brain mappings to constrain formal models of cognition.

    Directory of Open Access Journals (Sweden)

    Jelmer P Borst

    Full Text Available In this paper we propose a method to create data-driven mappings from components of cognitive models to brain regions. Cognitive models are notoriously hard to evaluate, especially based on behavioral measures alone. Neuroimaging data can provide additional constraints, but this requires a mapping from model components to brain regions. Although such mappings can be based on the experience of the modeler or on a reading of the literature, a formal method is preferred to prevent researcher-based biases. In this paper we used model-based fMRI analysis to create a data-driven model-brain mapping for five modules of the ACT-R cognitive architecture. We then validated this mapping by applying it to two new datasets with associated models. The new mapping was at least as powerful as an existing mapping that was based on the literature, and indicated where the models were supported by the data and where they have to be improved. We conclude that data-driven model-brain mappings can provide strong constraints on cognitive models, and that model-based fMRI is a suitable way to create such mappings.

  9. Sparse multivariate autoregressive modeling for mild cognitive impairment classification.

    Science.gov (United States)

    Li, Yang; Wee, Chong-Yaw; Jie, Biao; Peng, Ziwen; Shen, Dinggang

    2014-07-01

    Brain connectivity network derived from functional magnetic resonance imaging (fMRI) is becoming increasingly prevalent in the researches related to cognitive and perceptual processes. The capability to detect causal or effective connectivity is highly desirable for understanding the cooperative nature of brain network, particularly when the ultimate goal is to obtain good performance of control-patient classification with biological meaningful interpretations. Understanding directed functional interactions between brain regions via brain connectivity network is a challenging task. Since many genetic and biomedical networks are intrinsically sparse, incorporating sparsity property into connectivity modeling can make the derived models more biologically plausible. Accordingly, we propose an effective connectivity modeling of resting-state fMRI data based on the multivariate autoregressive (MAR) modeling technique, which is widely used to characterize temporal information of dynamic systems. This MAR modeling technique allows for the identification of effective connectivity using the Granger causality concept and reducing the spurious causality connectivity in assessment of directed functional interaction from fMRI data. A forward orthogonal least squares (OLS) regression algorithm is further used to construct a sparse MAR model. By applying the proposed modeling to mild cognitive impairment (MCI) classification, we identify several most discriminative regions, including middle cingulate gyrus, posterior cingulate gyrus, lingual gyrus and caudate regions, in line with results reported in previous findings. A relatively high classification accuracy of 91.89 % is also achieved, with an increment of 5.4 % compared to the fully-connected, non-directional Pearson-correlation-based functional connectivity approach.

  10. Dynamic simulation of sustainable farm development scenarios using cognitive modeling

    Directory of Open Access Journals (Sweden)

    Tuzhyk Kateryna

    2017-03-01

    Full Text Available Dynamic simulation of sustainable farm development scenarios using cognitive modeling. The paper presents a dynamic simulation system of sustainable development scenarios on farms using cognitive modeling. The system incorporates relevant variables which affect the sustainable development of farms. Its user provides answers to strategic issues connected with the level of farm sustainability over a long-term perspective of dynamic development. The work contains a description of the model structure as well as the results of simulations carried out on 16 farms in northern Ukraine. The results show that the process of sustainability is based mainly on the potential for innovation in agricultural production and biodiversity. The user is able to simulate various scenarios for the sustainable development of a farm and visualize the influence of factors on the economic and social situation, as well as on environmental aspects. Upon carrying out a series of simulations, it was determined that the development of farms characterized by sustainable development is based on additional profit, which serves as the main motivation for transforming a conventional farm into a sustainable one. Nevertheless, additional profit is not the only driving force in the system of sustainable development. The standard of living, market condition, and legal regulations as well as government support also play a significant motivational role.

  11. Influence of three different implant thread designs on stress distribution: A three-dimensional finite element analysis

    Directory of Open Access Journals (Sweden)

    Mansi Manish Oswal

    2016-01-01

    Full Text Available Purpose: Clinical success of implant prosthodontics is dependent in part upon the type of implant thread design. The selection of implant thread design plays an important role in the outcome of the treatment. This study was undertaken to evaluate the pattern of stress distribution using a finite element analysis; hence, the area which would be bearing maximum load for a given design would be arrived. Materials and Methods: Three implants with different thread designs, namely V-thread, buttress, and reverse buttress thread designs were considered and dimensions were standardized. The site considered was the mandibular molar region with cortical and trabecular bone assuming to be isotropic and homogeneous. The implant modeling was done with the CATIA software. Vertical loads of 100N were applied. The stresses were calculated as Von Mises stress criterion. Results: Maximum stresses were seen at the cortical bone and were transferred to the implant. Minimum Von Mises stresses were seen with reverse buttress thread design at the cortical bone. The stresses were observed least at the cancellous bone and maximum at the implant. Conclusion: Hence, within the limitations of this study the results obtained can be applied clinically for appropriate selection of implant thread design for a predictable success of implant therapy.

  12. Influence of three different implant thread designs on stress distribution: A three-dimensional finite element analysis.

    Science.gov (United States)

    Oswal, Mansi Manish; Amasi, Ulhas N; Oswal, Manish S; Bhagat, Ashish S

    2016-01-01

    Clinical success of implant prosthodontics is dependent in part upon the type of implant thread design. The selection of implant thread design plays an important role in the outcome of the treatment. This study was undertaken to evaluate the pattern of stress distribution using a finite element analysis; hence, the area which would be bearing maximum load for a given design would be arrived. Three implants with different thread designs, namely V-thread, buttress, and reverse buttress thread designs were considered and dimensions were standardized. The site considered was the mandibular molar region with cortical and trabecular bone assuming to be isotropic and homogeneous. The implant modeling was done with the CATIA software. Vertical loads of 100N were applied. The stresses were calculated as Von Mises stress criterion. Maximum stresses were seen at the cortical bone and were transferred to the implant. Minimum Von Mises stresses were seen with reverse buttress thread design at the cortical bone. The stresses were observed least at the cancellous bone and maximum at the implant. Hence, within the limitations of this study the results obtained can be applied clinically for appropriate selection of implant thread design for a predictable success of implant therapy.

  13. Assessing cognitive processes related to insomnia: A review and measurement guide for Harvey's cognitive model for the maintenance of insomnia.

    Science.gov (United States)

    Hiller, Rachel M; Johnston, Anna; Dohnt, Hayley; Lovato, Nicole; Gradisar, Michael

    2015-10-01

    Cognitive processes play an important role in the maintenance, and treatment of sleep difficulties, including insomnia. In 2002, a comprehensive model was proposed by Harvey. Since its inception the model has received >300 citations, and provided researchers and clinicians with a framework for understanding and treating insomnia. The aim of this review is two-fold. First, we review the current literature investigating each factor proposed in Harvey's cognitive model of insomnia. Second, we summarise the psychometric properties of key measures used to assess the model's factors and mechanisms. From these aims, we demonstrate both strengths and limitations of the current knowledge of appropriate measurements associated with the model. This review aims to stimulate and guide future research in this area; and provide an understanding of the resources available to measure, target, and resolve cognitive factors that may maintain chronic insomnia. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Rasch modeling of accuracy and confidence measures from cognitive tests.

    Science.gov (United States)

    Paek, Insu; Lee, Jihyun; Stankov, Lazar; Wilson, Mark

    2013-01-01

    The use of IRT models has not been rigorously applied in studies of the relationship between test-takers' confidence and accuracy. This study applied the Rasch measurement models to investigate the relationship between test-takers' confidence and accuracy on English proficiency tests, proposing potentially useful measures of under or overconfidence. The Rasch approach provided the scaffolding to formulate indices that can assess the discrepancy between confidence and accuracy at the item or total test level, as well as at particular ability levels locally. In addition, a "disattenuated" measure of association between accuracy and confidence, which takes measurement error into account, was obtained through a multidimensional Rasch modeling of the two constructs where the latent variance-covariance structure is directly estimated from the data. The results indicate that the participants tend to show overconfidence bias in their own cognitive abilities.

  15. Cooperative cognitive radio networking system model, enabling techniques, and performance

    CERN Document Server

    Cao, Bin; Mark, Jon W

    2016-01-01

    This SpringerBrief examines the active cooperation between users of Cooperative Cognitive Radio Networking (CCRN), exploring the system model, enabling techniques, and performance. The brief provides a systematic study on active cooperation between primary users and secondary users, i.e., (CCRN), followed by the discussions on research issues and challenges in designing spectrum-energy efficient CCRN. As an effort to shed light on the design of spectrum-energy efficient CCRN, they model the CCRN based on orthogonal modulation and orthogonally dual-polarized antenna (ODPA). The resource allocation issues are detailed with respect to both models, in terms of problem formulation, solution approach, and numerical results. Finally, the optimal communication strategies for both primary and secondary users to achieve spectrum-energy efficient CCRN are analyzed.

  16. In Search of Common Threads: Linking Multicultural, Feminist, and Social Justice Counseling Paradigms

    Science.gov (United States)

    Crethar, Hugh C.; Rivera, Edil Torres; Nash, Sara

    2008-01-01

    Multicultural, feminist, and social justice counseling theories are often viewed as disparate helping models. This article examines the complementary nature of these models and discusses the need to promote a clearer understanding of the ways in which these common threads can be used in counseling practice.

  17. In Search of Common Threads: Linking Multicultural, Feminist, and Social Justice Counseling Paradigms

    Science.gov (United States)

    Crethar, Hugh C.; Rivera, Edil Torres; Nash, Sara

    2008-01-01

    Multicultural, feminist, and social justice counseling theories are often viewed as disparate helping models. This article examines the complementary nature of these models and discusses the need to promote a clearer understanding of the ways in which these common threads can be used in counseling practice.

  18. Study the Possibility for Manufacturing a Conical Pipe Thread by Expansion

    Directory of Open Access Journals (Sweden)

    S. A. Evsyukov

    2014-01-01

    Full Text Available The experience of operating oil wells showed that the weak point of tubing is a connecting thread.Currently, the pipe thread of the specified class is made using the technology of cutting. The process of cutting a thread leads to waste metal chips and cutting fibers. Therefore the idea arose to make a thread by the method of pressure shaping.The aim was to study the possibility for full filling of the threaded matrix profile.The study was conducted by means of mathematical modeling in the software complex DEFORM. The impact of technological and geometrical factors on the process of form change was in detail analyzed. Thus, a work-piece material was specified to be continuous, isotropic, homogeneous, viscous-plastic and a tool material was set as a hard one. The friction was speci-fied according to Prandtl-Siebel law with the friction factor of 0.3. The thread profile has been replaced by the annular grooves of the similar profile. The task was considered to be axisymmetric.Scientific novelty of received results consists in revealed regularities of the plastic de-formation process of the work-piece when forming a profile of the conical thread on the pipe in the process of its expansion with a conical punch.The simulation allowed us to obtain information about the stress-strain state of the work-piece and tool, about the nature of the metal flow during deformation, and about the strength parameters of the process.In particular, it was found that the work-piece metal is displaced along the pipe axis both in punch movement direction and in the opposite one. Thus, a mechanical end burr is formed. The article shows that to remove a mechanical end burr requires insertion of extra limit stop housing. The article also analyses distribution of stresses arising in the matrix at the final moment of deformation. It was proved that the highest stresses occur in the hollows of the threaded part of matrix. Thus, their absolute value does not exceed 470 MPa that

  19. Calculus for cognitive scientists partial differential equation models

    CERN Document Server

    Peterson, James K

    2016-01-01

    This book shows cognitive scientists in training how mathematics, computer science and science can be usefully and seamlessly intertwined. It is a follow-up to the first two volumes on mathematics for cognitive scientists, and includes the mathematics and computational tools needed to understand how to compute the terms in the Fourier series expansions that solve the cable equation. The latter is derived from first principles by going back to cellular biology and the relevant biophysics.  A detailed discussion of ion movement through cellular membranes, and an explanation of how the equations that govern such ion movement leading to the standard transient cable equation are included. There are also solutions for the cable model using separation of variables, as well an explanation of why Fourier series converge and a description of the implementation of MatLab tools to compute the solutions. Finally, the standard Hodgkin - Huxley model is developed for an excitable neuron and is solved using MatLab.

  20. A cognitive learning model of clinical nursing leadership.

    Science.gov (United States)

    Pepin, Jacinthe; Dubois, Sylvie; Girard, Francine; Tardif, Jacques; Ha, Laurence

    2011-04-01

    Cognitive modeling of competencies is important to facilitate learning and evaluation. Clinical nursing leadership is considered a competency, as it is a "complex know-act" that students and nurses develop for the quality of care of patients and their families. Previous research on clinical leadership describes the attributes and characteristics of leaders and leadership, but, to our knowledge, a cognitive learning model (CLM) has yet to be developed. The purpose of our research was to develop a CLM of the clinical nursing leadership competency, from the beginning of a nursing program to expertise. An interpretative phenomenological study design was used 1) to document the experience of learning and practicing clinical leadership, and 2) to identify critical-learning turning points. Data was gathered from interviews with 32 baccalaureate students and 21 nurses from two clinical settings. An inductive analysis of data was conducted to determine the learning stages experienced: awareness of clinical leadership in nursing; integration of clinical leadership in actions; active leadership with patient/family; active leadership with the team; and, embedded clinical leadership extended to organizational level and beyond. The resulting CLM could have significant impact on both basic and continuing nursing education. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Automatic Thread-Level Parallelization in the Chombo AMR Library

    Energy Technology Data Exchange (ETDEWEB)

    Christen, Matthias; Keen, Noel; Ligocki, Terry; Oliker, Leonid; Shalf, John; Van Straalen, Brian; Williams, Samuel

    2011-05-26

    The increasing on-chip parallelism has some substantial implications for HPC applications. Currently, hybrid programming models (typically MPI+OpenMP) are employed for mapping software to the hardware in order to leverage the hardware?s architectural features. In this paper, we present an approach that automatically introduces thread level parallelism into Chombo, a parallel adaptive mesh refinement framework for finite difference type PDE solvers. In Chombo, core algorithms are specified in the ChomboFortran, a macro language extension to F77 that is part of the Chombo framework. This domain-specific language forms an already used target language for an automatic migration of the large number of existing algorithms into a hybrid MPI+OpenMP implementation. It also provides access to the auto-tuning methodology that enables tuning certain aspects of an algorithm to hardware characteristics. Performance measurements are presented for a few of the most relevant kernels with respect to a specific application benchmark using this technique as well as benchmark results for the entire application. The kernel benchmarks show that, using auto-tuning, up to a factor of 11 in performance was gained with 4 threads with respect to the serial reference implementation.

  2. Dysfunctional cognitions and their emotional, behavioral, and functional correlates in adults with attention deficit hyperactivity disorder (ADHD): is the cognitive-behavioral model valid?

    Science.gov (United States)

    Torrente, Fernando; López, Pablo; Alvarez Prado, Dolores; Kichic, Rafael; Cetkovich-Bakmas, Marcelo; Lischinsky, Alicia; Manes, Facundo

    2014-07-01

    To investigate the presence of dysfunctional cognitions in adults with ADHD and to determine whether these cognitions are associated with emotional symptoms, maladaptive coping, and functional impairment, as predicted by the cognitive-behavioral model. A total of 35 adult participants with ADHD, 20 nonclinical controls, and 20 non-ADHD clinical controls were assessed with measures of ADHD symptoms, dysfunctional cognitions, depression and anxiety symptoms, coping strategies, and quality of life. ADHD group showed elevated scores of dysfunctional cognitions relative to nonclinical control group and comparable with clinical control group. Dysfunctional cognitions were strongly associated with emotional symptoms. ADHD group also showed elevated scores in maladaptive coping strategies of the escape-avoidance type. Life impairment was satisfactorily predicted in data analysis when ADHD symptoms, dysfunctional cognitions, and emotional symptoms were fitted into a regression model. Cognitive-behavioral therapy model appears to be a valid complementary model for understanding emotional and life impairment in adults with ADHD. © 2012 SAGE Publications.

  3. Threading homology through algebra selected patterns

    CERN Document Server

    Boffi, Giandomenico

    2006-01-01

    Aimed at graduate students and researchers in mathematics, this book takes homological themes, such as Koszul complexes and their generalizations, and shows how these can be used to clarify certain problems in selected parts of algebra, as well as their success in solving a number of them. - ;Threading Homology through Algebra takes homological themes (Koszul complexes and their variations, resolutions in general) and shows how these affect the perception of certain problems in selected parts of algebra, as well as their success in solving a number of them. The text deals with regular local ri

  4. Studies on Woolen Threads from Historical Tapestries

    OpenAIRE

    Odlyha, Marianne; Theodorakopoulos, Charis; Campana, Roberto

    2007-01-01

    Fourier transform (FTIR) attenuated total reflectance (ATR)and second derivative spectroscopy has been used for the first time to evaluate the state of degradation in historical woollen threads from the collections of Flemish tapestries (15th-17th centuries) in the Royal Palace, Madrid, Hampton Court Palace, and museums in Brussels. The work was performed as part of the EC-funded project ‘Monitoring of Damage in Historic Tapestries’, also known as the MODHT project. The overall aim was to dev...

  5. Load balancing in distributed framework for frequency based thread pools

    Directory of Open Access Journals (Sweden)

    Sheraz Ahmad

    2016-12-01

    Full Text Available The consequence of load balancing algorithms on a thread pool framework name is distributed load balancing frequency based optimization scheme (LDFBOS to increase its execution. Load balancing in distributed frequency based thread pool scheme is residential towards the ground of synchronizing overhead crude named LDFBOS in Java that slows down its execution due to framework exchange and synchronizing overhead in nodes, we are demonstrating the contrive and execution of load balancing in distributed frequency based thread pool LDFBOS to does usage from distributed in frequency based thread pool (DFBOS, synchronizing primitives that propose benefits of significant scalable moreover, dynamism. We have got resembled the execution of some schemes by Thread Pool Tester which is a Java application simulator and the consequence have demonstrated that load balancing in distributed frequency based thread pool LDFBOS exceeds preceding DFBOS scheme.

  6. Cognitive Elements of Empowerment: An "Interpretive" Model of Intrinsic Task Motivation

    OpenAIRE

    Thomas, Kenneth W.; Velthouse, Betty A.

    1990-01-01

    This article presents a cognitive model of empowerment. Here, empowerment is defined as increased intrinsic task motivation, and our subsequent model identifies four cognitions (task assessments) as the basis for worker empowerment: sense of impact, competence, meaningfulness, and choice. Adopting an interpretive perspective, we have used the model also to describe cognitive processes through which workers reach these conclusions. Central to the processes we describe are ...

  7. Model-based cognitive neuroscience: a conceptual introduction

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.; Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    This tutorial chapter shows how the separate fields of mathematical psychology and cognitive neuroscience can interact to their mutual benefit. Historically, the field of mathematical psychology is mostly concerned with formal theories of behavior, whereas cognitive neuroscience is mostly concerned

  8. Model-based cognitive neuroscience: a conceptual introduction

    NARCIS (Netherlands)

    Forstmann, B.U.; Wagenmakers, E.-J.; Forstmann, B.U.; Wagenmakers, E.-J.

    2015-01-01

    This tutorial chapter shows how the separate fields of mathematical psychology and cognitive neuroscience can interact to their mutual benefit. Historically, the field of mathematical psychology is mostly concerned with formal theories of behavior, whereas cognitive neuroscience is mostly concerned

  9. Latent Variable Models, Cognitive Modelling, and Working Memory: a Meeting Point

    OpenAIRE

    Rodríguez-Villagra, Odir Antonio

    2015-01-01

    Latent variable models and formal cognitive models share some elements of their object of study, variousphilosophical aspects, and some parts of their methodology. Nevertheless, little communication exists between their theories and findings. In order to highlight similarities and differences, this study implemented and tested a formal model proposing that interference among representations is a mechanism limiting working memory capacity (i.e., the interference model of Oberauer & Kliegl, 200...

  10. Nature's longest threads new frontiers in the mathematics and physics of information in biology

    CERN Document Server

    Sreekantan, B V

    2014-01-01

    Organisms endowed with life show a sense of awareness, interacting with and learning from the universe in and around them. Each level of interaction involves transfer of information of various kinds, and at different levels. Each thread of information is interlinked with the other, and woven together, these constitute the universe — both the internal self and the external world — as we perceive it. They are, figuratively speaking, Nature's longest threads. This volume reports inter-disciplinary research and views on information and its transfer at different levels of organization by reputed scientists working on the frontier areas of science. It is a frontier where physics, mathematics and biology merge seamlessly, binding together specialized streams such as quantum mechanics, dynamical systems theory, and mathematics. The topics would interest a broad cross-section of researchers in life sciences, physics, cognition, neuroscience, mathematics and computer science, as well as interested amateurs, familia...

  11. Cognitive aging and hearing acuity: modeling spoken language comprehension.

    Science.gov (United States)

    Wingfield, Arthur; Amichetti, Nicole M; Lash, Amanda

    2015-01-01

    The comprehension of spoken language has been characterized by a number of "local" theories that have focused on specific aspects of the task: models of word recognition, models of selective attention, accounts of thematic role assignment at the sentence level, and so forth. The ease of language understanding (ELU) model (Rönnberg et al., 2013) stands as one of the few attempts to offer a fully encompassing framework for language understanding. In this paper we discuss interactions between perceptual, linguistic, and cognitive factors in spoken language understanding. Central to our presentation is an examination of aspects of the ELU model that apply especially to spoken language comprehension in adult aging, where speed of processing, working memory capacity, and hearing acuity are often compromised. We discuss, in relation to the ELU model, conceptions of working memory and its capacity limitations, the use of linguistic context to aid in speech recognition and the importance of inhibitory control, and language comprehension at the sentence level. Throughout this paper we offer a constructive look at the ELU model; where it is strong and where there are gaps to be filled.

  12. Modeling cognitive loads for evolving shared mental models in human-agent collaboration.

    Science.gov (United States)

    Fan, Xiaocong; Yen, John

    2011-04-01

    Recent research on human-centered teamwork highly demands the design of cognitive agents that can model and exploit human partners' cognitive load to enhance team performance. In this paper, we focus on teams composed of human-agent pairs and develop a system called Shared Mental Models for all--SMMall. SMMall implements a hidden Markov model (HMM)-based cognitive load model for an agent to predict its human partner's instantaneous cognitive load status. It also implements a user interface (UI) concept called shared belief map, which offers a synergic representation of team members' information space and allows them to share beliefs. An experiment was conducted to evaluate the HMM-based load models. The results indicate that the HMM-based load models are effective in helping team members develop a shared mental model (SMM), and the benefit of load-based information sharing becomes more significant as communication capacity increases. It also suggests that multiparty communication plays an important role in forming/evolving team SMMs, and when a group of agents can be partitioned into subteams, splitting messages by their load status can be more effective for developing subteam SMMs.

  13. Fast user-level inter-thread communication, synchronisation

    OpenAIRE

    Kevin J. Vella; Lin, Li; ; 1st Workshop in Information and Communication Technology (WICT 2008)

    2008-01-01

    This project concerns the design and implementation of user-level inter-thread synchronisation and communication algorithms. A number of these algorithms have been implemented on the SMASH user-level thread scheduler for symmetric multiprocessors and multicore processors. All inter-thread communication primitives considered have two implementations: the lock-based implementation and the lock-free implementation. The performance of concurrent programs using these user-level primitives are meas...

  14. Cognitive Systems Modeling and Analysis of Command and Control Systems

    Science.gov (United States)

    Norlander, Arne

    2012-01-01

    Military operations, counter-terrorism operations and emergency response often oblige operators and commanders to operate within distributed organizations and systems for safe and effective mission accomplishment. Tactical commanders and operators frequently encounter violent threats and critical demands on cognitive capacity and reaction time. In the future they will make decisions in situations where operational and system characteristics are highly dynamic and non-linear, i.e. minor events, decisions or actions may have serious and irreversible consequences for the entire mission. Commanders and other decision makers must manage true real time properties at all levels; individual operators, stand-alone technical systems, higher-order integrated human-machine systems and joint operations forces alike. Coping with these conditions in performance assessment, system development and operational testing is a challenge for both practitioners and researchers. This paper reports on research from which the results led to a breakthrough: An integrated approach to information-centered systems analysis to support future command and control systems research development. This approach integrates several areas of research into a coherent framework, Action Control Theory (ACT). It comprises measurement techniques and methodological advances that facilitate a more accurate and deeper understanding of the operational environment, its agents, actors and effectors, generating new and updated models. This in turn generates theoretical advances. Some good examples of successful approaches are found in the research areas of cognitive systems engineering, systems theory, and psychophysiology, and in the fields of dynamic, distributed decision making and naturalistic decision making.

  15. Cognitive bias in the chick anxiety-depression model.

    Science.gov (United States)

    Salmeto, Amy L; Hymel, Kristen A; Carpenter, Erika C; Brilot, Ben O; Bateson, Melissa; Sufka, Kenneth J

    2011-02-10

    Cognitive bias is a phenomenon that presents in clinical populations where anxious individuals tend to adopt a more pessimistic-like interpretation of ambiguous aversive stimuli whereas depressed individuals tend to adopt a less optimistic-like interpretation of ambiguous appetitive stimuli. To further validate the chick anxiety-depression model as a neuropsychiatric simulation we sought to quantify this cognitive endophenotype. Chicks exposed to an isolation stressor of 5m to induce an anxiety-like or 60 m to induce a depressive-like state were then tested in a straight alley maze to a series of morphed ambiguous appetitive (chick silhouette) to aversive (owl silhouette) cues. In non-isolated controls, runway start and goal latencies generally increased as a function of greater amounts of aversive characteristics in the cues. In chicks in the anxiety-like state, runway latencies were increased to aversive ambiguous cues, reflecting more pessimistic-like behavior. In chicks in the depression-like state, runway latencies were increased to both aversive and appetitive ambiguous cues, reflecting more pessimistic-like and less optimistic-like behavior, respectively.

  16. AN MHD AVALANCHE IN A MULTI-THREADED CORONAL LOOP

    Energy Technology Data Exchange (ETDEWEB)

    Hood, A. W.; Cargill, P. J.; Tam, K. V. [School of Mathematics and Statistics, University of St Andrews, St Andrews, Fife, KY16 9SS (United Kingdom); Browning, P. K., E-mail: awh@st-andrews.ac.uk [School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom)

    2016-01-20

    For the first time, we demonstrate how an MHD avalanche might occur in a multithreaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable in order to start an avalanche even when the others are below marginal stability. This has significant implications for coronal heating in that it provides for energy dissipation with a trigger mechanism. The instability of the unstable thread follows the evolution determined in many earlier investigations. However, once one stable thread is disrupted, it coalesces with a neighboring thread and this process disrupts other nearby threads. Coalescence with these disrupted threads then occurs leading to the disruption of yet more threads as the avalanche develops. Magnetic energy is released in discrete bursts as the surrounding stable threads are disrupted. The volume integrated heating, as a function of time, shows short spikes suggesting that the temporal form of the heating is more like that of nanoflares than of constant heating.

  17. Laser Fabrication of Miniature Internal Thread in Glass Substrate

    Directory of Open Access Journals (Sweden)

    Hiroyuki Degawa

    2017-02-01

    Full Text Available Miniature internal threads (tapped holes of S0.5 were fabricated in a glass substrate. Water-assisted laser drilling was applied for fabrication of the threads of S0.5 standard using a subnanosecond laser as a light source. The landscape of the inner surface of the threads was measured by a laser microscope, and showed reasonable agreement with the desired standard. As a proof of concept, a commercial external screw was fitted to the fabricated internal thread.

  18. High-viscosity fluid threads in weakly diffusive microfluidic systems

    Science.gov (United States)

    Cubaud, T.; Mason, T. G.

    2009-07-01

    We provide an overview of the flow dynamics of highly viscous miscible liquids in microfluidic geometries. We focus on the lubricated transport of high-viscosity fluids interacting with less viscous fluids, and we review methods for producing and manipulating single and multiple core-annular flows, i.e. viscous threads, in compact and plane microgeometries. In diverging slit microchannels, a thread's buckling instabilities can be employed for generating ordered and disordered miscible microstructures, as well as for partially blending low- and high-viscosity materials. The shear-induced destabilization of a thread that flows off-center in a square microchannel is examined as a means for continuously producing miscible dispersions. We show original compound threads and viscous dendrites that are generated using three fluids, each of which has a large viscosity contrast with the others. Thread motions in zones of microchannel extensions are examined in both miscible and immiscible environments. We demonstrate that high-viscosity fluid threads in weakly diffusive microfluidic systems correspond to the viscous primary flow and can be used as a starting point for studying and understanding the destabilizing effects of interfacial tension as well as diffusion. Characteristic of lubricated transport, threads facilitate the transport of very viscous materials in small fluidic passages, while mitigating dissipation. Threads are also potentially promising for soft material synthesis and diagnostics with independent control of the thread specific surface and residence time in micro-flow reactors.

  19. High precision optomechanical assembly using threads as mechanical reference

    Science.gov (United States)

    Lamontagne, Frédéric; Desnoyers, Nichola; Bergeron, Guy; Cantin, Mario

    2016-09-01

    A convenient method to assemble optomechanical components is to use threaded interface. For example, lenses are often secured inside barrels using threaded rings. In other cases, multiple optical sub-assemblies such as lens barrels can be threaded to each other. Threads have the advantage to provide a simple assembly method, to be easy to manufacture, and to offer a compact mechanical design. On the other hand, threads are not considered to provide accurate centering between parts because of the assembly clearance between the inner and outer threads. For that reason, threads are often used in conjunction with precision cylindrical surfaces to limit the radial clearance between the parts to be centered. Therefore, tight manufacturing tolerances are needed on these pilot diameters, which affect the cost of the optical assembly. This paper presents a new optomechanical approach that uses threads as mechanical reference. This innovative method relies on geometric principles to auto-center parts to each other with a very low centering error that is usually less than 5 μm. The method allows to auto-center an optical group in a main barrel, to perform an axial adjustment of an optical group inside a main barrel, and to perform stacking of multiple barrels. In conjunction with the lens auto-centering method that also used threads as a mechanical reference, this novel solution opens new possibilities to realize a variety of different high precision optomechanical assemblies at lower cost.

  20. Cognitive Model Exploration and Optimization: A New Challenge for Computational Science

    Science.gov (United States)

    2010-03-01

    colleagues is called MindModeling@Home, and it too runs on the BOINC infrastructure (Harris, Gluck, Mielke & Moore, 2009). Projects that work well with...mathematical and cognitive modeling. Cognitive Science, 33(5), 880-910. Harris, J., Gluck, K. A., Mielke , T., & Moore, L. R. (2009). MindModeling

  1. Parental Attachment, Cognitive Working Models, and Depression among African American College Students

    Science.gov (United States)

    Love, Keisha M.; Murdock, Tamera B.

    2012-01-01

    In an attempt to understand the cognitive mechanisms by which parental attachments predict depression among African American college students, the authors examined a mediational path model containing parental attachment, cognitive working models, and depression. The model demonstrated a close fit to the data, and several significant paths emerged.…

  2. Distributed Cognition and the Shared Knowledge Model of the Mazahua: A Cultural Approach.

    Science.gov (United States)

    de Haan, Mariette

    2002-01-01

    Discussion of distributed cognition and school reform focuses on the teaching and learning practices of a Native American group, the Mexican Mazahuas. Topics include knowledge construction; a shared knowledge model of learning; interconnectedness between knowledge and practice; models of guidance; cognitive apprenticeship models; shared…

  3. Ability, Breadth, and Parsimony in Computational Models of Higher-Order Cognition

    Science.gov (United States)

    Cassimatis, Nicholas L.; Bello, Paul; Langley, Pat

    2008-01-01

    Computational models will play an important role in our understanding of human higher-order cognition. How can a model's contribution to this goal be evaluated? This article argues that three important aspects of a model of higher-order cognition to evaluate are (a) its ability to reason, solve problems, converse, and learn as well as people do;…

  4. Implications of Neuroscientific Evidence for the Cognitive Models of Post-Traumatic Stress Disorder

    Science.gov (United States)

    Cruwys, Tegan; O'Kearney, Richard

    2008-01-01

    Brewin's dual representation theory, Ehlers and Clark's cognitive appraisal model, and Dalgleish's schematic, propositional, analogue and associative representational systems model are considered in the light of recent evidence on the neural substrates of post-traumatic stress disorder (PTSD). The models' proposals about the cognitive mechanism of…

  5. COGNITIVE MODELS OF PREDICTION THE DEVELOPMENT OF A DIVERSIFIED CORPORATION

    Directory of Open Access Journals (Sweden)

    Baranovskaya T. P.

    2016-10-01

    Full Text Available The application of classical forecasting methods applied to a diversified corporation faces some certain difficulties, due to its economic nature. Unlike other businesses, diversified corporations are characterized by multidimensional arrays of data with a high degree of distortion and fragmentation of information due to the cumulative effect of the incompleteness and distortion of accounting information from the enterprises in it. Under these conditions, the applied methods and tools must have high resolution and work effectively with large databases with incomplete information, ensure the correct common comparable quantitative processing of the heterogeneous nature of the factors measured in different units. It is therefore necessary to select or develop some methods that can work with complex poorly formalized tasks. This fact substantiates the relevance of the problem of developing models, methods and tools for solving the problem of forecasting the development of diversified corporations. This is the subject of this work, which makes it relevant. The work aims to: 1 analyze the forecasting methods to justify the choice of system-cognitive analysis as one of the effective methods for the prediction of semi-structured tasks; 2 to adapt and develop the method of systemic-cognitive analysis for forecasting of dynamics of development of the corporation subject to the scenario approach; 3 to develop predictive model scenarios of changes in basic economic indicators of development of the corporation and to assess their credibility; 4 determine the analytical form of the dependence between past and future scenarios of various economic indicators; 5 develop analytical models weighing predictable scenarios, taking into account all prediction results with positive levels of similarity, to increase the level of reliability of forecasts; 6 to develop a calculation procedure to assess the strength of influence on the corporation (sensitivity of its

  6. Models of cognitive behavior in nuclear power plant personnel. A feasibility study: main report. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    Woods, D.D.; Roth, E.M.; Hanes, L.F.

    1986-07-01

    This report contains the results of a feasibility study to determine if the current state of models human cognitive activities can serve as the basis for improved techniques for predicting human error in nuclear power plants emergency operations. Based on the answer to this questions, two subsequent phases of research are planned. Phase II is to develop a model of cognitive activities, and Phase III is to test the model. The feasibility study included an analysis of the cognitive activities that occur in emergency operations and an assessment of the modeling concepts/tools available to capture these cognitive activities. The results indicated that a symbolic processing (or artificial intelligence) model of cognitive activities in nuclear power plants is both desirable and feasible. This cognitive model can be built upon the computational framework provided by an existing artificial intelligence system for medical problem solving called Caduceus. The resulting cognitive model will increase the capability to capture the human contribution to risk in probabilistic risk assessments studies. Volume I summarizes the major findings and conclusions of the study. Volume II provides a complete description of the methods and results, including a synthesis of the cognitive activities that occur during emergency operations, and a literature review on cognitive modeling relevant to nuclear power plants. 112 refs., 10 figs.

  7. Multi-dimensional profiling of medical students' cognitive models about learning.

    Science.gov (United States)

    Askell-Williams, Helen; Lawson, Michael J

    2006-02-01

    In current constructivist paradigms, learners' previous subject-matter knowledge, or cognitive models, provide the foundations for the construction of new knowledge. Learners' cognitive models about learning also mediate students' capacities to learn in their chosen topics of study. The diverse backgrounds of students entering medicine suggest that they might come to medical studies equipped with a wide variety of cognitive models about learning. Some current theories tend to reduce students' cognitions about learning to parsimonious representations, such as surface-deep approaches or mastery-performance goals. It is possible that such reduced representations underrepresent, or misrepresent, the complexity of students' cognitive models about learning. Good quality teaching needs to take account of learners' cognitive models, not just about subject matter, but also about learning. This study investigated the diversity and complexity of medical students' cognitive models about learning. A total of 7 graduate entry, clinical-year medical students volunteered for in-depth interviews about learning. NUD*IST text analysis software and correspondence analysis were employed to identify dimensions and to profile students' responses. The correspondence analysis identified a significant 4-dimensional solution that illustrates the contributions of multiple variables to students' cognitive models about learning. Individual profiles highlight diversity between participants. This study provides evidence that students' cognitive models about learning are complex and highly differentiated. Representations of what students know about learning need to take account of such complexity in order to inform instructional practice more adequately.

  8. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation.

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-11-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility. We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition model can aim to be cognitively plausible in multiple ways. We discuss these cognitive plausibility checkpoints generally and then apply them to a case study in word segmentation, investigating a promising Bayesian segmentation strategy. We incorporate cognitive plausibility by using an age-appropriate unit of perceptual representation, evaluating the model output in terms of its utility, and incorporating cognitive constraints into the inference process. Our more cognitively plausible model shows a beneficial effect of cognitive constraints on segmentation performance. One interpretation of this effect is as a synergy between the naive theories of language structure that infants may have and the cognitive constraints that limit the fidelity of their inference processes, where less accurate inference approximations are better when the underlying assumptions about how words are generated are less accurate. More generally, these results highlight the utility of incorporating cognitive plausibility more fully into computational models of language acquisition.

  9. Integrating end-to-end threads of control into object-oriented analysis and design

    Science.gov (United States)

    Mccandlish, Janet E.; Macdonald, James R.; Graves, Sara J.

    1993-01-01

    Current object-oriented analysis and design methodologies fall short in their use of mechanisms for identifying threads of control for the system being developed. The scenarios which typically describe a system are more global than looking at the individual objects and representing their behavior. Unlike conventional methodologies that use data flow and process-dependency diagrams, object-oriented methodologies do not provide a model for representing these global threads end-to-end. Tracing through threads of control is key to ensuring that a system is complete and timing constraints are addressed. The existence of multiple threads of control in a system necessitates a partitioning of the system into processes. This paper describes the application and representation of end-to-end threads of control to the object-oriented analysis and design process using object-oriented constructs. The issue of representation is viewed as a grouping problem, that is, how to group classes/objects at a higher level of abstraction so that the system may be viewed as a whole with both classes/objects and their associated dynamic behavior. Existing object-oriented development methodology techniques are extended by adding design-level constructs termed logical composite classes and process composite classes. Logical composite classes are design-level classes which group classes/objects both logically and by thread of control information. Process composite classes further refine the logical composite class groupings by using process partitioning criteria to produce optimum concurrent execution results. The goal of these design-level constructs is to ultimately provide the basis for a mechanism that can support the creation of process composite classes in an automated way. Using an automated mechanism makes it easier to partition a system into concurrently executing elements that can be run in parallel on multiple processors.

  10. 具有真实感的长纱丝形态图像智能生成系统核心算法的设计%Design of Key Algorithm about Intelligent Produce the Configuration of Continuous Twisted Thread System Based on Real Feeling

    Institute of Scientific and Technical Information of China (English)

    徐汀荣

    2003-01-01

    This thesis illustrates configuration of continuous twisted thread mathematic model construction and the key algorithm of how to intelligent produce the configuration of continuous twisted thread real picture from its mathe-matic model construction and basic sample image. The system can produce user wanted product picture by changing continuous twisted thread parameter, can also realize buy at ether place. Textile industry is Chinese great industry,so CAD of continuous twisted thread developing future is very beautiful.

  11. Modeling Educational Content: The Cognitive Approach of the PALO Language

    Directory of Open Access Journals (Sweden)

    M. Felisa Verdejo Maíllo

    2004-01-01

    Full Text Available This paper presents a reference framework to describe educational material. It introduces the PALO Language as a cognitive based approach to Educational Modeling Languages (EML. In accordance with recent trends for reusability and interoperability in Learning Technologies, EML constitutes an evolution of the current content-centered specifications of learning material, involving the description of learning processes and methods from a pedagogical and instructional perspective. The PALO Language, thus, provides a layer of abstraction for the description of learning material, including the description of learning activities, structure and scheduling. The framework makes use of domain and pedagogical ontologies as a reusable and maintainable way to represent and store instructional content, and to provide a pedagogical level of abstraction in the authoring process.

  12. Cognitive modeling and multi criteria decision making in macroeconomic analysis

    Directory of Open Access Journals (Sweden)

    Leonova Nina

    2014-01-01

    Full Text Available Decision making in macroeconomics belongs to the class of ill-structured tasks with strong external factors interdependence, a limited number of management tools and experts groups' subjectivity. This paper suggests a technique of macroeconomic analysis which includes methods of cognitive modeling for formalizing a problem situation and scenario generation as a basis of the typical multicriteria decision making task. In turn, for solving this task is suggested a method based on measuring the distance to the 'ideal' solution with determining importance of criteria by finding objective, common component of all values measured by experts groups. For extracting this 'commonality' means of factor analysis are used. Such an approach allows separating of the objective part in experts' value from a subjective one, while the technique at whole provides formalization of macroeconomic problems and substantiation of decision-making in macroeconomics.

  13. Study of thread grinding based on the multi-body system theory%基于多体系统理论的螺纹磨削研究

    Institute of Scientific and Technical Information of China (English)

    范晋伟; 金爱韦; 宁堃; 梅钦; 李海涌

    2012-01-01

    将多体系统运动建模方法应用到数控螺纹磨床建模中,建立机床、工件和砂轮的运动关系,推导出多线砂轮磨削螺纹的加工方程.开发螺纹磨削仿真软件,获得螺纹磨削加工G代码,在磨削螺纹的生产中取得了很好的效果.%Applying the multi-body system modeling theory to CNC thread grinder modeling. Deriving multi-line grinding wheel thread processing equation based on movement relationship of machine tool, workpiece and grinding wheel. A thread grinding simulation software is developed, and the generating thread grinding G-code achieves good results in the production of thread grinding.

  14. Optimum Thread Rolling Process That Improves SCC Resistance

    Energy Technology Data Exchange (ETDEWEB)

    A.R. Kephart

    2001-10-29

    Accelerated testing in environments aggressive for the specific material have shown that fastener threads that are rolled after strengthening heat treatments have improved resistance to SCC initiation. For example, intergranular SCC was produced in one day when machined (cut) threads of high strength steel (ASTM A193 B-7 and A354 Grade 8) were exposed to an aggressive aqueous environment containing 8 weight % boiling ammonium nitrate and stressed to about 40% of the steel's yield strength (120 ksi, 827 MPa). In similar testing conditions, fasteners that had threads rolled before heat-treatment (quench and temper) had similar susceptibility to SCC. However, threads rolled after strengthening, exhibited no SCC after a week of exposure, even when stressed to 100% of the B-7 alloy yield strength. Similarly, intergranular SCC was produced in less than one day when machined (cut) threads of nickel-base alloys (X-750 and aged 625) were exposed to an aggressive 750 F doped steam environment (containing 100 ppm of chloride, fluoride, sulfate, nitrate and a controlled hydrogen overpressure) and stressed to about 80% of the alloy yield strength (117 ksi, 807 MPa). In similar testing conditions, threads rolled after strengthening exhibited no SCC after 50 days of exposure. This beneficial effect of the optimum thread rolling process (i.e., threads rolled after strengthening) is due to the retention of large residual compressive stresses in the thread roots (notches) which mitigate the applied notch tensile stresses resulting from joint design pre-loads. use of these material specific aggressive environments can provide an accelerated test to verify that threads were produced by the optimum thread rolling process. These tests could support fastener acceptance criteria or failure analysis of fasteners with unknown or uncertain manufacturing processes. The optimum process effects may not always be detected by more conventional methods (e.g., metallography or hardness testing).

  15. Explorations in combining cognitive models of individuals and system dynamics models of groups.

    Energy Technology Data Exchange (ETDEWEB)

    Backus, George A.

    2008-07-01

    This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

  16. Computational models of music perception and cognition II: Domain-specific music processing

    Science.gov (United States)

    Purwins, Hendrik; Grachten, Maarten; Herrera, Perfecto; Hazan, Amaury; Marxer, Ricard; Serra, Xavier

    2008-09-01

    In Part I [Purwins H, Herrera P, Grachten M, Hazan A, Marxer R, Serra X. Computational models of music perception and cognition I: The perceptual and cognitive processing chain. Physics of Life Reviews 2008, in press, doi:10.1016/j.plrev.2008.03.004], we addressed the study of cognitive processes that underlie auditory perception of music, and their neural correlates. The aim of the present paper is to summarize empirical findings from music cognition research that are relevant to three prominent music theoretic domains: rhythm, melody, and tonality. Attention is paid to how cognitive processes like category formation, stimulus grouping, and expectation can account for the music theoretic key concepts in these domains, such as beat, meter, voice, consonance. We give an overview of computational models that have been proposed in the literature for a variety of music processing tasks related to rhythm, melody, and tonality. Although the present state-of-the-art in computational modeling of music cognition definitely provides valuable resources for testing specific hypotheses and theories, we observe the need for models that integrate the various aspects of music perception and cognition into a single framework. Such models should be able to account for aspects that until now have only rarely been addressed in computational models of music cognition, like the active nature of perception and the development of cognitive capacities from infancy to adulthood.

  17. Social Cognitive Model of College Satisfaction: A Test of Measurement and Path Models

    Science.gov (United States)

    Feldt, Ronald C.

    2012-01-01

    The study examined a model that integrates social-cognitive and trait-personality constructs to examine two domains of college satisfaction. Direct and indirect effects were observed for conscientiousness, perception of institutional resources, self-efficacy, and goal progress. Paths differed for personal and institutional satisfaction. Most…

  18. Processes models, environmental analyses, and cognitive architectures: quo vadis quantum probability theory?

    Science.gov (United States)

    Marewski, Julian N; Hoffrage, Ulrich

    2013-06-01

    A lot of research in cognition and decision making suffers from a lack of formalism. The quantum probability program could help to improve this situation, but we wonder whether it would provide even more added value if its presumed focus on outcome models were complemented by process models that are, ideally, informed by ecological analyses and integrated into cognitive architectures.

  19. A Prospective Test of Cognitive Vulnerability Models of Depression with Adolescent Girls

    Science.gov (United States)

    Bohon, Cara; Stice, Eric; Burton, Emily; Fudell, Molly; Nolen-Hoeksema, Susan

    2008-01-01

    This study sought to provide a more rigorous prospective test of two cognitive vulnerability models of depression with longitudinal data from 496 adolescent girls. Results supported the cognitive vulnerability model in that stressors predicted future increases in depressive symptoms and onset of clinically significant major depression for…

  20. A Note on Comparing Examinee Classification Methods for Cognitive Diagnosis Models

    Science.gov (United States)

    Huebner, Alan; Wang, Chun

    2011-01-01

    Cognitive diagnosis models have received much attention in the recent psychometric literature because of their potential to provide examinees with information regarding multiple fine-grained discretely defined skills, or attributes. This article discusses the issue of methods of examinee classification for cognitive diagnosis models, which are…

  1. Cognitive Modeling and Self-Efficacy: Effects on Preservice Teachers' Learning of Teaching Strategies.

    Science.gov (United States)

    Gorrell, Jeffrey; Capron, Earl

    1990-01-01

    Examines how cognitive modeling and self-efficacy affected preservice teachers' learning of teaching strategies. Two groups of students viewed videotaped training sessions with direct instruction or cognitive modeling. They then viewed either self-efficacy or task-oriented commentaries. Results indicated significant effects favoring cognitive…

  2. A Model for Developing Meta-Cognitive Tools in Teacher Apprenticeships

    Science.gov (United States)

    Bray, Paige; Schatz, Steven

    2013-01-01

    This research investigates a model for developing meta-cognitive tools to be used by pre-service teachers during apprenticeship (student teaching) experience to operationalise the epistemological model of Cook and Brown (2009). Meta-cognitive tools have proven to be effective for increasing performance and retention of undergraduate students.…

  3. Test of a Social Cognitive Model of Work Satisfaction in Teachers

    Science.gov (United States)

    Duffy, Ryan D.; Lent, Robert W.

    2009-01-01

    Lent and Brown [Lent, R. W., & Brown, S. D. (2006). "Integrating person and situation perspectives on work satisfaction: A social-cognitive view." "Journal of Vocational Behavior,69", 236-247] recently proposed an integrative model of work satisfaction linked to social cognitive career theory. The model posits that work satisfaction is predicted…

  4. A Biblical-Theological Model of Cognitive Dissonance Theory: Relevance for Christian Educators

    Science.gov (United States)

    Bowen, Danny Ray

    2012-01-01

    The purpose of this content analysis research was to develop a biblical-theological model of Cognitive Dissonance Theory applicable to pedagogy. Evidence of cognitive dissonance found in Scripture was used to infer a purpose for the innate drive toward consonance. This inferred purpose was incorporated into a model that improves the descriptive…

  5. Flexible Design and Implementation of Cognitive Models for Predicting Pilot Errors in Cockpit Design

    NARCIS (Netherlands)

    Diggelen, J. van; Janssen, J.; Mioch, T.

    2010-01-01

    This paper describes an integrated design and implementation framework for cognitive models in complex task environments. We propose a task- and humancentered development methodology for deriving the cognitive models, and present a goal-based framework for implementing them. We illustrate our approa

  6. Cognitive Models of Writing: Writing Proficiency as a Complex Integrated Skill

    Science.gov (United States)

    Deane, Paul; Odendahl, Nora; Quinlan, Thomas; Fowles, Mary; Welsh, Cyndi; Bivens-Tatum, Jennifer

    2008-01-01

    This paper undertakes a review of the literature on writing cognition, writing instruction, and writing assessment with the goal of developing a framework and competency model for a new approach to writing assessment. The model developed is part of the Cognitively Based Assessments of, for, and as Learning (CBAL) initiative, an ongoing research…

  7. A Biblical-Theological Model of Cognitive Dissonance Theory: Relevance for Christian Educators

    Science.gov (United States)

    Bowen, Danny Ray

    2012-01-01

    The purpose of this content analysis research was to develop a biblical-theological model of Cognitive Dissonance Theory applicable to pedagogy. Evidence of cognitive dissonance found in Scripture was used to infer a purpose for the innate drive toward consonance. This inferred purpose was incorporated into a model that improves the descriptive…

  8. Confidentiality for Probabilistic Multi-Threaded Programs and Its Verification

    NARCIS (Netherlands)

    Ngo, Minh Tri; Stoelinga, Mariëlle Ida Antoinette; Huisman, Marieke

    2012-01-01

    Confidentiality is an important concern in today's information society: electronic payment and personal data should be protected appropriately. This holds in particular for multi-threaded applications, which are generally seen the future of high-performance computing. Multi-threading poses new

  9. 通用线程库的设计与实现%Design and Implementation of the Common Thread Library

    Institute of Scientific and Technical Information of China (English)

    洪承煜; 许自龙; 亢永敢; 杨尚琴

    2012-01-01

    With the development of the integration of seismic exploration software in the acquisition, processing, explaining, builds cloud computing platform of a cross-hardware, operating system that becomes necessary; and in cloud comp g platforms, the common thread library becomes the key to the development of a large amount of computation algorithm of seismic software. In the paper, the analysis of the threading model and synchronization mechanisms, sorting out the property of the thread, thread control, thread flow and synchronization properties and operation; finally, on the basis of these common components, to package a variety of local thread library, so that implement cross-platform common thread library on basis of any native threads library.%随着采集、处理、解释一体化地震勘探软件的发展,构建跨硬件、操作系统的云计算平台成为必要;而云计算平台中,通用线程库成为开发有大计算量算法的地震勘探软件的关键.通过对线程模型和同步机制的分析,分类整理出线程的属性、线程的控制、线程执行流的构建和同步的属性及操作;最后在这些通用的组件基础上,通过对各种本地线程库的封装,实现基于任意本地线程库的跨平台通用线程库.

  10. Cognitive Modeling for Closed-Loop Task Mitigation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — As flightdeck equipment becomes more sophisticated and complex, operations become significantly more cognitively demanding. When tasks demands exceed the operator's...

  11. Going beyond the unitary curve: incorporating richer cognition into agent-based water resources models

    Science.gov (United States)

    Kock, B. E.

    2008-12-01

    The increased availability and understanding of agent-based modeling technology and techniques provides a unique opportunity for water resources modelers, allowing them to go beyond traditional behavioral approaches from neoclassical economics, and add rich cognition to social-hydrological models. Agent-based models provide for an individual focus, and the easier and more realistic incorporation of learning, memory and other mechanisms for increased cognitive sophistication. We are in an age of global change impacting complex water resources systems, and social responses are increasingly recognized as fundamentally adaptive and emergent. In consideration of this, water resources models and modelers need to better address social dynamics in a manner beyond the capabilities of neoclassical economics theory and practice. However, going beyond the unitary curve requires unique levels of engagement with stakeholders, both to elicit the richer knowledge necessary for structuring and parameterizing agent-based models, but also to make sure such models are appropriately used. With the aim of encouraging epistemological and methodological convergence in the agent-based modeling of water resources, we have developed a water resources-specific cognitive model and an associated collaborative modeling process. Our cognitive model emphasizes efficiency in architecture and operation, and capacity to adapt to different application contexts. We describe a current application of this cognitive model and modeling process in the Arkansas Basin of Colorado. In particular, we highlight the potential benefits of, and challenges to, using more sophisticated cognitive models in agent-based water resources models.

  12. Evaluation of stress pattern generated through various thread designs of dental implants loaded in a condition of immediately after placement and on osseointegration--an FEA study.

    Science.gov (United States)

    Chowdhary, Ramesh; Halldin, Anders; Jimbo, Ryo; Wennerberg, Ann

    2013-02-01

    To determine the stress pattern generated through various thread design in experimental simulation models, when loaded immediately after placement and after osseointegration. Three-dimensional (3D) models were designed using CATIA, computer-aided design modeling software. The study was planned in 2 stages. Eight 2D models were constructed of different thread forms, one set with frictionless and other with bonded for bone to implant interface and loaded vertically with 100 N. In Stage II, 6 3D models of the different threads embedded in the cortical bone were constructed and loaded vertically and obliquely. In 2D models, the von Mises stress concentrated at the crest in the bonded connection thread designs. The stress levels were in the range of 7 to 13 MPa. In the frictional implant bone interface, the thread designs had a clear effect on the stress levels in the bone. In the 3D analysis, the complete implant design affected the stress levels. The thread design affects the magnitude of the stress peak in the bone more effectively in immediately loaded (frictionless) implants than the osseointegrated (bonded) implants. Maximum stress was observed at the first thread in most of the osseointegrated implants.

  13. CPC: programming with a massive number of lightweight threads

    CERN Document Server

    Kerneis, Gabriel

    2011-01-01

    Threads are a convenient and modular abstraction for writing concurrent programs, but often fairly expensive. The standard alternative to threads, event-loop programming, allows much lighter units of concurrency, but leads to code that is difficult to write and even harder to understand. Continuation Passing C (CPC) is a translator that converts a program written in threaded style into a program written with events and native system threads, at the programmer's choice. Together with two undergraduate students, we taught ourselves how to program in CPC by writing Hekate, a massively concurrent network server designed to efficiently handle tens of thousands of simultaneously connected peers. In this paper, we describe a number of programming idioms that we learnt while writing Hekate; while some of these idioms are specific to CPC, many should be applicable to other programming systems with sufficiently cheap threads.

  14. Measurement of Threads by Scanning on Coordinate Measuring Machines

    DEFF Research Database (Denmark)

    Carmignato, Simone; Savio, Enrico; De Chiffre, Leonardo

    2003-01-01

    This paper presents the latest developments on a new method for the calibration of thread gauges by scanning of thread profiles on coordinate measuring machines. The method is compared with other traditional techniques for discussion of advantages and harmonisation of measuring results. Investiga......This paper presents the latest developments on a new method for the calibration of thread gauges by scanning of thread profiles on coordinate measuring machines. The method is compared with other traditional techniques for discussion of advantages and harmonisation of measuring results....... Investigations and tests are conducted on elements of the procedure for reduction of both the measuring uncertainty and the procedure duration. Further developments to extend the method to threads of different sizes and geometries are presented....

  15. Stitched Together: Transitioning CMS to a Hierarchical Threaded Framework

    Science.gov (United States)

    Jones, C. D.; Sexton-Kennedy, E.

    2014-06-01

    Modern computing hardware is transitioning from using a single high frequency complicated computing core to many lower frequency simpler cores. As part of that transition, hardware manufacturers are urging developers to exploit concurrency in their programs via operating system threads. We will present CMS' effort to evolve our single threaded framework into a highly concurrent framework. We will outline the design of the new framework and how the design was constrained by the initial single threaded design. Then we will discuss the tools we have used to identify and correct thread unsafe user code. Finally we will end with a description of the coding patterns we found useful when converting code to being thread-safe.

  16. The impact of motivation on cognitive performance in an animal model of the negative and cognitive symptoms of schizophrenia.

    Science.gov (United States)

    Ward, Ryan D; Winiger, Vanessa; Higa, Kerin K; Kahn, Julia B; Kandel, Eric R; Balsam, Peter D; Simpson, Eleanor H

    2015-06-01

    Interactions between motivation and cognition are implicated in producing functional impairments and poor quality of life in psychiatric patients. This interaction, however, is not well understood at either the behavioral or neural level. We developed a procedure for mice in which a cognitive measure, sustained attention, is modulated by a motivationally relevant signal that predicts reward probability on a trial-by-trial basis. Using this paradigm, we tested the interaction between motivation and cognition in mice that model the increased striatal D2 receptor activity observed in schizophrenia patients (D2R-OE mice). In control mice, attention was modulated by signaled-reward probability. In D2R-OE mice, however, attention was not modulated by reward-related cues. This impairment was not due to any global deficits in attention or maintenance of the trial-specific information in working memory. Turning off the transgene in D2R-OE mice rescued the motivational modulation of attention. These results indicate that deficits in motivation impair the ability to use reward-related cues to recruit attention and that improving motivation improves functional cognitive performance. These results further suggest that addressing motivational impairments in patients is critical to achieving substantive cognitive and functional gains.

  17. Biological and artificial cognition: what can we learn about mechanisms by modelling physical cognition problems using artificial intelligence planning techniques?

    Science.gov (United States)

    Chappell, Jackie; Hawes, Nick

    2012-01-01

    Do we fully understand the structure of the problems we present to our subjects in experiments on animal cognition, and the information required to solve them? While we currently have a good understanding of the behavioural and neurobiological mechanisms underlying associative learning processes, we understand much less about the mechanisms underlying more complex forms of cognition in animals. In this study, we present a proposal for a new way of thinking about animal cognition experiments. We describe a process in which a physical cognition task domain can be decomposed into its component parts, and models constructed to represent both the causal events of the domain and the information available to the agent. We then implement a simple set of models, using the planning language MAPL within the MAPSIM simulation environment, and applying it to a puzzle tube task previously presented to orangutans. We discuss the results of the models and compare them with the results from the experiments with orangutans, describing the advantages of this approach, and the ways in which it could be extended. PMID:22927571

  18. Biological and artificial cognition: what can we learn about mechanisms by modelling physical cognition problems using artificial intelligence planning techniques?

    Science.gov (United States)

    Chappell, Jackie; Hawes, Nick

    2012-10-05

    Do we fully understand the structure of the problems we present to our subjects in experiments on animal cognition, and the information required to solve them? While we currently have a good understanding of the behavioural and neurobiological mechanisms underlying associative learning processes, we understand much less about the mechanisms underlying more complex forms of cognition in animals. In this study, we present a proposal for a new way of thinking about animal cognition experiments. We describe a process in which a physical cognition task domain can be decomposed into its component parts, and models constructed to represent both the causal events of the domain and the information available to the agent. We then implement a simple set of models, using the planning language MAPL within the MAPSIM simulation environment, and applying it to a puzzle tube task previously presented to orangutans. We discuss the results of the models and compare them with the results from the experiments with orangutans, describing the advantages of this approach, and the ways in which it could be extended.

  19. Cognitive Dysfunction in Major Depressive Disorder. A Translational Review in Animal Models of the Disease.

    Science.gov (United States)

    Darcet, Flavie; Gardier, Alain M; Gaillard, Raphael; David, Denis J; Guilloux, Jean-Philippe

    2016-02-17

    Major Depressive Disorder (MDD) is the most common psychiatric disease, affecting millions of people worldwide. In addition to the well-defined depressive symptoms, patients suffering from MDD consistently complain about cognitive disturbances, significantly exacerbating the burden of this illness. Among cognitive symptoms, impairments in attention, working memory, learning and memory or executive functions are often reported. However, available data about the heterogeneity of MDD patients and magnitude of cognitive symptoms through the different phases of MDD remain difficult to summarize. Thus, the first part of this review briefly overviewed clinical studies, focusing on the cognitive dysfunctions depending on the MDD type. As animal models are essential translational tools for underpinning the mechanisms of cognitive deficits in MDD, the second part of this review synthetized preclinical studies observing cognitive deficits in different rodent models of anxiety/depression. For each cognitive domain, we determined whether deficits could be shared across models. Particularly, we established whether specific stress-related procedures or unspecific criteria (such as species, sex or age) could segregate common cognitive alteration across models. Finally, the role of adult hippocampal neurogenesis in rodents in cognitive dysfunctions during MDD state was also discussed.

  20. Comparative analysis of cognitive tasks for modeling mental workload with electroencephalogram.

    Science.gov (United States)

    Hwang, Taeho; Kim, Miyoung; Hwangbo, Minsu; Oh, Eunmi

    2014-01-01

    Previous electroencephalogram (EEG) studies have shown that cognitive workload can be estimated by using several types of cognitive tasks. In this study, we attempted to characterize cognitive tasks that have been used to manipulate workload for generating classification models. We carried out a comparative analysis between two representative types of working memory tasks: the n-back task and the mental arithmetic task. Based on experiments with 7 healthy subjects using Emotiv EPOC, we compared the consistency, robustness, and efficiency of each task in determining cognitive workload in a short training session. The mental arithmetic task seems consistent and robust in manipulating clearly separable high and low levels of cognitive workload with less training. In addition, the mental arithmetic task shows consistency despite repeated usage over time and without notable task adaptation in users. The current study successfully quantifies the quality and efficiency of cognitive workload modeling depending on the type and configuration of training tasks.

  1. Cognitive Process Modeling of Spatial Ability: The Assembling Objects Task

    Science.gov (United States)

    Ivie, Jennifer L.; Embretson, Susan E.

    2010-01-01

    Spatial ability tasks appear on many intelligence and aptitude tests. Although the construct validity of spatial ability tests has often been studied through traditional correlational methods, such as factor analysis, less is known about the cognitive processes involved in solving test items. This study examines the cognitive processes involved in…

  2. Dynamics, models, and mechanisms of the cognitive flexibility of preschoolers

    NARCIS (Netherlands)

    van Bers, B.M.C.W.

    2014-01-01

    Flexibility is a significant ability in the present rapidly changing society. In a novel situation or when circumstances change, one’s automatic inclinations provide no guidance, and conscious cognitive control is required. Cognitive flexibility is one of the component abilities that constitute cogn

  3. Multiscale Modeling of Gene-Behavior Associations in an Artificial Neural Network Model of Cognitive Development.

    Science.gov (United States)

    Thomas, Michael S C; Forrester, Neil A; Ronald, Angelica

    2016-01-01

    In the multidisciplinary field of developmental cognitive neuroscience, statistical associations between levels of description play an increasingly important role. One example of such associations is the observation of correlations between relatively common gene variants and individual differences in behavior. It is perhaps surprising that such associations can be detected despite the remoteness of these levels of description, and the fact that behavior is the outcome of an extended developmental process involving interaction of the whole organism with a variable environment. Given that they have been detected, how do such associations inform cognitive-level theories? To investigate this question, we employed a multiscale computational model of development, using a sample domain drawn from the field of language acquisition. The model comprised an artificial neural network model of past-tense acquisition trained using the backpropagation learning algorithm, extended to incorporate population modeling and genetic algorithms. It included five levels of description-four internal: genetic, network, neurocomputation, behavior; and one external: environment. Since the mechanistic assumptions of the model were known and its operation was relatively transparent, we could evaluate whether cross-level associations gave an accurate picture of causal processes. We established that associations could be detected between artificial genes and behavioral variation, even under polygenic assumptions of a many-to-one relationship between genes and neurocomputational parameters, and when an experience-dependent developmental process interceded between the action of genes and the emergence of behavior. We evaluated these associations with respect to their specificity (to different behaviors, to function vs. structure), to their developmental stability, and to their replicability, as well as considering issues of missing heritability and gene-environment interactions. We argue that gene

  4. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence From Word Segmentation

    National Research Council Canada - National Science Library

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's cognitive plausibility...

  5. Novel Virtual User Models of Mild Cognitive Impairment for Simulating Dementia

    Directory of Open Access Journals (Sweden)

    Sofia Segkouli

    2015-01-01

    Full Text Available Virtual user modeling research has attempted to address critical issues of human-computer interaction (HCI such as usability and utility through a large number of analytic, usability-oriented approaches as cognitive models in order to provide users with experiences fitting to their specific needs. However, there is demand for more specific modules embodied in cognitive architecture that will detect abnormal cognitive decline across new synthetic task environments. Also, accessibility evaluation of graphical user interfaces (GUIs requires considerable effort for enhancing ICT products accessibility for older adults. The main aim of this study is to develop and test virtual user models (VUM simulating mild cognitive impairment (MCI through novel specific modules, embodied at cognitive models and defined by estimations of cognitive parameters. Well-established MCI detection tests assessed users’ cognition, elaborated their ability to perform multitasks, and monitored the performance of infotainment related tasks to provide more accurate simulation results on existing conceptual frameworks and enhanced predictive validity in interfaces’ design supported by increased tasks’ complexity to capture a more detailed profile of users’ capabilities and limitations. The final outcome is a more robust cognitive prediction model, accurately fitted to human data to be used for more reliable interfaces’ evaluation through simulation on the basis of virtual models of MCI users.

  6. The Importance of Cognitive Phenotypes in Experimental Modeling of Animal Anxiety and Depression

    OpenAIRE

    Kalueff, Allan V.; Murphy, Dennis L.

    2007-01-01

    Cognitive dysfunctions are commonly seen in many stress-related disorders, including anxiety and depression—the world's most common neuropsychiatric illnesses. Various genetic, pharmacological, and behavioral animal models have long been used to establish animal anxiety-like and depression-like phenotypes, as well as to assess their memory, learning, and other cognitive functions. Mounting clinical and animal evidences strongly supports the notion that disturbed cognitions represent an import...

  7. Unpicking the signal thread of the sector web spider Zygiella x-notata.

    Science.gov (United States)

    Mortimer, Beth; Holland, Chris; Windmill, James F C; Vollrath, Fritz

    2015-12-06

    Remote sensing allows an animal to extend its morphology with appropriate conductive materials and sensors providing environmental feedback from spatially removed locations. For example, the sector web spider Zygiella x-notata uses a specialized thread as both a structural bridge and signal transmitter to monitor web vibrations from its retreat at the web perimeter. To unravel this model multifunctional system, we investigated Zygiella's signal thread structure with a range of techniques, including tensile testing, laser vibrometry, electron microscopy and behavioural analysis. We found that signal threads varied significantly in the number of filaments; a result of the spider adding a lifeline each time it runs along the bridge. Our mechanical property analysis suggests that while the structure varies, its normalized load does not. We propose that the signal thread represents a complex and fully integrated multifunctional structure where filaments can be added, thus increasing absolute load-bearing capacity while maintaining signal fidelity. We conclude that such structures may serve as inspiration for remote sensing design strategies.

  8. Cognitive Model and Cognitive Load Evaluation of Information Retrieval%信息检索认知模型及认知负荷评价研究

    Institute of Scientific and Technical Information of China (English)

    刘佳; 沈旺; 李贺

    2012-01-01

    通过对信息检索认知理论的研究,构建信息检索认知模型。依据信息检索认知模型及认知负荷理论,构建信息检索认知过程中认知负荷结构模型,并提出认知负荷评价的基本框架。通过实证研究,对数字图书馆信息检索认知过程中的认知负荷进行评价并指出其动态变化。%This paper defines the user cognitive model of information retrieval through the analysis of cognitive theory. Based on the cognitive model of information retrieval and cognitive load theory, it constructs the structural model of the cognitive load in the cognitive processes of information retrieval and the cognitive load framework. It evaluates information retrieval of digital library in the cognitive processes of cognitive load by empirical research, and pointes out that the cognitive load dynamically changes in the cognitive process of information retrieval.

  9. Joint modeling for cognitive trajectory and risk of dementia in the presence of death.

    Science.gov (United States)

    Yu, Binbing; Ghosh, Pulak

    2010-03-01

    Dementia is characterized by accelerated cognitive decline before and after diagnosis as compared to normal aging. It has been known that cognitive impairment occurs long before the diagnosis of dementia. For individuals who develop dementia, it is important to determine the time when the rate of cognitive decline begins to accelerate and the subsequent gap time to dementia diagnosis. For normal aging individuals, it is also useful to understand the trajectory of cognitive function until their death. A Bayesian change-point model is proposed to fit the trajectory of cognitive function for individuals who develop dementia. In real life, people in older ages are subject to two competing risks, e.g., dementia and dementia-free death. Because the majority of people do not develop dementia, a mixture model is used for survival data with competing risks, which consists of dementia onset time after the change point of cognitive function decline for demented individuals and death time for nondemented individuals. The cognitive trajectories and the survival process are modeled jointly and the parameters are estimated using the Markov chain Monte Carlo method. Using data from the Honolulu Asia Aging Study, we show the trajectories of cognitive function and the effect of education, apolipoprotein E 4 genotype, and hypertension on cognitive decline and the risk of dementia.

  10. Information theory-based approach for modeling the cognitive behavior of NPP operators

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-10-01

    An NPP system consists of three important components: the machine system, operators, and MMI. Through the MMI, operators monitor and control the plant system. The cognitive model of NPP operators has become a target of modeling by cognitive engineers due to their work environment: complex, uncertain, and safe critical. We suggested the contextual model for the cognitive behavior of NPP operator and the mathematical fundamentals based on information theory which can quantify the model. The demerit of the methodology using the information theory is that it cannot evaluate the correctness and quality of information. Therefore, the validation through the experiment is needed.

  11. Race-related cognitive test bias in the active study: a mimic model approach.

    Science.gov (United States)

    Aiken Morgan, Adrienne T; Marsiske, Michael; Dzierzewski, Joseph M; Jones, Richard N; Whitfield, Keith E; Johnson, Kathy E; Cresci, Mary K

    2010-10-01

    The present study investigated evidence for race-related test bias in cognitive measures used in the baseline assessment of the ACTIVE clinical trial. Test bias against African Americans has been documented in both cognitive aging and early life span studies. Despite significant mean performance differences, Multiple Indicators Multiple Causes (MIMIC) models suggested most differences were at the construct level. There was little evidence that specific measures put either group at particular advantage or disadvantage and little evidence of cognitive test bias in this sample. Small group differences in education, cognitive status, and health suggest positive selection may have attenuated possible biases.

  12. Modeling neurodevelopmental cognitive deficits in tasks with cross-species translational validity.

    Science.gov (United States)

    Cope, Z A; Powell, S B; Young, J W

    2016-01-01

    Numerous psychiatric disorders whose cognitive dysfunction links to functional outcome have neurodevelopmental origins including schizophrenia, autism and bipolar disorder. Treatments are needed for these cognitive deficits, which require development using animal models. Models of neurodevelopmental disorders are as varied and diverse as the disorders themselves, recreating some but not all aspects of the disorder. This variety may in part underlie why purported procognitive treatments translated from these models have failed to restore functioning in the targeted patient populations. Further complications arise from environmental factors used in these models that can contribute to numerous disorders, perhaps only impacting specific domains, while diagnostic boundaries define individual disorders, limiting translational efficacy. The Research Domain Criteria project seeks to 'develop new ways to classify mental disorders based on behavioral dimensions and neurobiological measures' in hopes of facilitating translational research by remaining agnostic toward diagnostic borders derived from clinical presentation in humans. Models could therefore recreate biosignatures of cognitive dysfunction irrespective of disease state. This review highlights work within the field of neurodevelopmental models of psychiatric disorders tested in cross-species translational cognitive paradigms that directly inform this newly developing research strategy. By expounding on this approach, the hopes are that a fuller understanding of each model may be attainable in terms of the cognitive profile elicited by each manipulation. Hence, conclusions may begin to be drawn on the nature of cognitive neuropathology on neurodevelopmental and other disorders, increasing the chances of procognitive treatment development for individuals affected in specific cognitive domains.

  13. New phacoemulsification tip with a grooved, threaded-tip construction.

    Science.gov (United States)

    Watanabe, Akinari

    2011-07-01

    To visually compare ultrasonic tip vibrations between a phaco tip with internal grooves (threaded tip) and a standard phaco tip during continuous-mode ultrasound (US) using ultra-high-speed digital video imaging. Watanabe Eye Clinic, Hyogo, Japan. Experimental study. The threaded tip was constructed by creating grooves inside a standard phaco tip using a screw. An ultra-high-speed digital video camera was used to record the image during continuous-mode US. Samples used in the test chamber during phacoemulsification included a piece of chestnut as a representative human lens sample and actual human lens fragments. Ultra-high-speed digital images showed that the threaded tip created a larger amount of cavitation than the standard phaco tip during US oscillation. Phacoemulsification of the sample using the standard phaco tip produced a chattering motion, making it difficult to maintain a steady tip position. The threaded tip produced little chattering motion, making it relatively easy to maintain a steady tip position. Once a piece of sample was gripped by the threaded tip, it was shaved and aspirated into the threaded tip without chattering motion. The mean effective phacoemulsification time (EPT) of the threaded tip was significantly shorter than that of the normal phaco tip (6.0 seconds ± 1.9 [SD] versus 15.4 ± 1.3 seconds; P=.002). The threaded tip created larger amounts of cavitation and had strong destructive and holding power. This threaded construction is simple to produce and appears to be very effective for phacoemulsification. Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  14. Modeling cognitive trajectories within longitudinal studies: a focus on older adults.

    Science.gov (United States)

    Steinerman, Joshua R; Hall, Charles B; Sliwinski, Martin J; Lipton, Richard B

    2010-10-01

    The natural history of life span cognitive performance and its late-life determinants have been studied from an array of perspectives. Significant insights come from psychological disciplines, including cognitive, developmental, and neuropsychology, as well as from medical specialties, such as geriatrics, neurology, psychiatry, neuroradiology, and neuropathology, that contribute to the growing interdisciplinary scientific field: cognitive neuroscience of aging. This survey of longitudinal studies of aging suggests that disease-oriented investigations commonly do not adequately consider normative cognitive changes, whereas developmental studies do not sufficiently measure and model nonnormative cognitive aging. This article argues for an integrative perspective that considers both of these influences on cognitive trajectories and presents a series of methodological concerns that have not been addressed comprehensively. Interdisciplinary methods from longitudinal observational studies should be leveraged to enable translational interventions to promote brain longevity.

  15. PET Evidence of the Effect of Donepezil on Cognitive Performance in an Animal Model of Chemobrain

    Directory of Open Access Journals (Sweden)

    Ilhan Lim

    2016-01-01

    Full Text Available A considerable number of patients with breast cancer complain of cognitive impairment after chemotherapy. In this study, we showed that donepezil enhanced memory function and increased brain glucose metabolism in a rat model of cognitive impairment after chemotherapy using behavioral analysis and positron emission tomography (PET. We found that chemotherapy affected spatial learning ability, reference memory, and working memory and that donepezil improved these cognitive impairments. According to PET analysis, chemotherapy reduced glucose metabolism in the medial prefrontal cortex and hippocampus, and donepezil increased glucose metabolism in the bilateral frontal lobe, parietal lobe, and hippocampus. Reduced glucose metabolism was more prominent after treatment with doxorubicin than cyclophosphamide. Our results demonstrated the neural mechanisms for cognitive impairment after chemotherapy and show that cognition was improved after donepezil intervention using both behavioral and imaging methods. Our results suggested that donepezil can be employed clinically for the treatment of cognitive deficits after chemotherapy.

  16. Have Cognitive Diagnostic Models Delivered Their Goods? Some Substantial and Methodological Concerns

    Science.gov (United States)

    Wilhelm, Oliver; Robitzsch, Alexander

    2009-01-01

    The paper by Rupp and Templin (2008) is an excellent work on the characteristics and features of cognitive diagnostic models (CDM). In this article, the authors comment on some substantial and methodological aspects of this focus paper. They organize their comments by going through issues associated with the terms "cognitive," "diagnostic" and…

  17. On the scientific status of cognitive appraisal models of anxiety disorder.

    Science.gov (United States)

    McNally, R J

    2001-05-01

    The cognitive paradigm for understanding and treating anxiety disorders comprises two distinct and potentially incompatible approaches: appraisal and information-processing. Advocates of the latter approach have sharply criticized the scientific adequacy of the appraisal models popularized by cognitive therapists. The purpose of this essay is to provide a reappraisal of these critiques of appraisal, and to defend an argument for methodological pluralism.

  18. Longitudinal Test of a Social Cognitive Model of Academic and Life Satisfaction

    Science.gov (United States)

    Singley, Daniel B.; Lent, Robert W.; Sheu, Hung-Bin

    2010-01-01

    The authors tested a social cognitive model of academic and overall life satisfaction in a sample of 769 university students. The predictors, drawn from Lent's unifying perspective on well-being and psychosocial adjustment, included social cognitive (academic self-efficacy, goal progress, social support) and personality (trait positive affect)…

  19. Helpful Components Involved in the Cognitive-Experiential Model of Dream Work

    Science.gov (United States)

    Tien, Hsiu-Lan Shelley; Chen, Shuh-Chi; Lin, Chia-Huei

    2009-01-01

    The purpose of the study was to examine the helpful components involved in the Hill's cognitive-experiential dream work model. Participants were 27 volunteer clients from colleges and universities in northern and central parts of Taiwan. Each of the clients received 1-2 sessions of dream interpretations. The cognitive-experiential dream work model…

  20. Supervision of Group Work: A Model to Increase Supervisee Cognitive Complexity

    Science.gov (United States)

    Granello, Darcy Haag; Underfer-Babalis, Jean

    2004-01-01

    This article describes a model for supervisors of group counselors to use to promote cognitive complexity in their supervisees. Counselor cognitive complexity has been linked to many positive counseling skills, including greater flexibility, empathy, confidence, and client conceptualization. Bloom's Taxonomy of Educational Objectives provides a…

  1. Measures and Models for Estimating and Predicting Cognitive Fatigue

    Science.gov (United States)

    Trejo, Leonard J.; Kochavi, Rebekah; Kubitz, Karla; Montgomery, Leslie D.; Rosipal, Roman; Matthews, Bryan

    2004-01-01

    We analyzed EEG and ERPs in a fatiguing mental task and created statistical models for single subjects. Seventeen subjects (4 F, 18-38 y) viewed 4-digit problems (e.g., 3+5-2+7=15) on a computer, solved the problems, and pressed keys to respond (intertrial interval = 1 s). Subjects performed until either they felt exhausted or three hours had elapsed. Re- and post-task measures of mood (Activation Deactivation Adjective Checklist, Visual Analogue Mood Scale) confirmed that fatigue increased and energy decreased over time. We tested response times (RT); amplitudes of ERP components N1, P2, P300, readiness potentials; and amplitudes of frontal theta and parietal alpha rhythms for change as a function of time. For subjects who completed 3 h (n=9) we analyzed 12 15-min blocks. For subjects who completed at least 1.5 h (n=17), we analyzed the first-, middle-, and last 100 error-free trials. Mean RT rose from 6.7 s to 8.5 s over time. We found no changes in the amplitudes of ERP components. In both analyses, amplitudes of frontal theta and parietal alpha rose by 30% or more over time. We used 30-channel EEG frequency spectra to model the effects of time in single subjects using a kernel partial least squares classifier. We classified 3.5s EEG segments as being from the first 100 or the last 100 trials, using random sub-samples of each class. Test set accuracies ranged from 63.9% to 99.6% correct. Only 2 of 17 subjects had mean accuracies lower than 80%. The results suggest that EEG accurately classifies periods of cognitive fatigue in 90% of subjects.

  2. A Cross-Cultural Study of the Cognitive Model of Depression: Cognitive Experiences Converge between Egypt and Canada

    Science.gov (United States)

    Beshai, Shadi; Dobson, Keith S; Adel, Ashraf; Hanna, Niveen

    2016-01-01

    Introduction Models of depression that arise in the West need to be examined in other regions of the world. This study examined a set of foundational hypotheses generated by Beck’s cognitive model of depression among depressed individuals in Egypt and Canada. Method We recruited 29 depressed and 29 non-depressed Egyptians and compared their results with those of 35 depressed and 38 non-depressed Canadians. Depression status was ascertained using a structured interview, scores on the Beck Depression Inventory, and scores on the Psychiatric Diagnostic Screening Questionnaire. Participants completed questionnaires designed to measure the frequency of negative and positive automatic thoughts (ATQ–N, BHS, and ATQ–P), and dysfunctional attitudes (DAS). Results Depressed individuals in both countries had significantly more negative thoughts about self and future, greater frequency of dysfunctional attitudes, and diminished positive self-thoughts in comparison to non-depressed individuals. Egyptians generally showed significantly more dysfunctional attitudes than their Canadian counterparts. Discussion The four hypotheses that were tested were supported among the depressed Egyptian sample, which is consistent with the cognitive model. Implications for the cognitive-behavioral model and treatment for this group of sufferers are discussed. PMID:27010706

  3. Model of Cognitive Readiness of Musical Education Students

    Directory of Open Access Journals (Sweden)

    Almagul T. Ermuratova

    2014-05-01

    Full Text Available The article features scientific studies on cognitive readiness of musical education students. The author, in the course of his study, focuses on ideas and experience of folk pedagogy. In the course of the study, the author determines criteria and elements of cognitive readiness. The key achievement of the article is an identification of three possible levels of students’ cognitive readiness. The author concludes that establishment of cognitive activities of future music teachers, comes from their knowledge pedagogical principles, pedagogical principles of educational unity, fostering and development of human being, consistency and sequence, identification of pedagogical approaches with regard to individual peculiarities of students and professional pedagogical interaction between teachers and students.

  4. A new method for thread calibration on coordinate measuring machines

    DEFF Research Database (Denmark)

    Carmignato, Simone; De Chiffre, Leonardo

    2003-01-01

    CIRP Annals – Paper proposal temporary reference: P15. This paper presents a new method for the calibration of thread gauges on coordinate measuring machines. The procedure involves scanning of thread profiles using a needle-like probe, achieving traceability by substitution of different thread......-3 gave measuring uncertainties comparable to the values from usual calibration methods on dedicated equipment, e.g. a measuring uncertainty of 1.5 µm was achieved for measurement of the pitch, and 2-2.5 µm for diameter measurements....

  5. Un modelo de threads reactivos usuario-kernel para Java

    OpenAIRE

    Pineda, Carlos; García Almiñana, Jordi; Flores, Jorge H.

    2004-01-01

    En este trabajo se presenta un modelo de threads usuario-kernel para Java, eficiente, altamente escalable, y orientado a la construcción de aplicaciones Internet de alto desempeño que requieren crear miles de threads y mantener igual número de conexiones simultáneas (p.e. servidores Web y servidores proxy). El modelo incluye un mecanismo de planificación reactiva que permite gestionar en forma implícita operaciones de I/O no bloqueantes sobre threads de usuario cooperativos.

  6. Chronic obstructive pulmonary disease. An original model of cognitive decline.

    Science.gov (United States)

    Incalzi, R A; Gemma, A; Marra, C; Muzzolon, R; Capparella, O; Carbonin, P

    1993-08-01

    In order to characterize the neuropsychologic profile of patients with hypoxic-hypercapnic chronic obstructive pulmonary disease (COPD), the performance of 36 patients with COPD 69 +/- 10 yr of age (mean +/- SD) on 19 tests exploring eight cognitive domains was compared with those of 29 normal adults (69 +/- 7 yr of age), 20 normal elderly adults (78 +/- 2 yr of age), 26 patients with Alzheimer-type dementia (72 +/- 6 yr of age), and 28 with multi-infarct dementia (MID) (70 +/- 8 yr of age). The discriminant analysis of cognitive test scores showed that 48.5% of patients with COPD had a specific pattern of cognitive deterioration characterized by a dramatic impairment in verbal and verbal memory tasks, well-preserved visual attention, and diffuse worsening of the other functions. The remaining patients with COPD were functionally classified as normal adults (12.1%), normal elderly adults (15.2%), those with MID (12.1%), and those with Alzheimer-type dementia (12.1%) according to discriminant analysis. Cognitive impairment was significantly and positively correlated with age (p analogies between age-related and COPD-related cognitive decline are evident, a distinct cognitive profile was found in a large fraction of patients with COPD and it differs in several aspects from those of both normal and demented subjects.

  7. Cognitive models applied to human effectiveness in national security environments (ergonomics of augmented cognition system design and application).

    Energy Technology Data Exchange (ETDEWEB)

    Ntuen, Celestine (North Carolina Agricultural and Technical State University, Greensboro, NC); Winchester, Woodrow III (North Carolina Agricultural and Technical State University, Greensboro, NC)

    2004-06-01

    In complex simulation systems where humans interact with computer-generated agents, information display and the interplay of virtual agents have become dominant media and modalities of interface design. This design strategy is reflected in augmented reality (AR), an environment where humans interact with computer-generated agents in real-time. AR systems can generate large amount of information, multiple solutions in less time, and perform far better in time-constrained problem solving. The capabilities of AR have been leveraged to augment cognition in human information processing. In this sort of augmented cognition (AC) work system, while technology has become the main source for information acquisition from the environment, the human sensory and memory capacities have failed to cope with the magnitude and scale of information they encounter. This situation generates opportunity for excessive cognitive workloads, a major factor in degraded human performance. From the human effectiveness point of view, research is needed to develop, model, and validate simulation tools that can measure the effectiveness of an AR technology used to support the amplification of human cognition. These tools will allow us to predict human performance for tasks executed under an AC tool construct. This paper presents an exploration of ergonomics issues relevant to AR and AC systems design. Additionally, proposed research to investigate those ergonomic issues is discussed.

  8. Modeling of Learners’ Interest in Blended Learning: Insights from Emotional Cognition

    Directory of Open Access Journals (Sweden)

    Chen Hai-Jian

    2016-01-01

    Full Text Available In blended learning, how to explore and evaluate the learner’s interest is very important. In this paper, we study on modeling of learners’ interest from the perspective of cognitive neuroscience. Emotional cognitive theory and brain cognitive process for situational learning interest were introduced. In addition, in order to solve the problem of quantitative assessment of interest, learner’s online operation behaviour was summarized through data mining methods, and the learners' interest regression model was built. Experimental results show that the accuracy of the model is more than 91% and it has good applicability in blended learning.

  9. Social learning theory and cognitive behavioral models of body dysmorphic disorder.

    Science.gov (United States)

    Neziroglu, Fugen; Khemlani-Patel, Sony; Veale, David

    2008-03-01

    Contemporary cognitive behavioral models of body dysmorphic disorder are reviewed, whereby the first by Neziroglu and colleagues emphasizes conditioning processes and relational frame theory and the latter by Veale emphasizes information processing. A brief review of the existing cognitive behavioral therapy research follows the presentation of the models. The majority of publications on BDD continue to deal with phenomenology and epidemiology, and much more research on cognitive behavioral treatment is needed. Treatment research should be geared towards testing elements of the models explicated in this article, and randomized controlled trials are greatly needed.

  10. Negative Cognition, Depressed Mood, and Paranoia: A Longitudinal Pathway Analysis Using Structural Equation Modeling

    Science.gov (United States)

    Fowler, David; Hodgekins, Joanne; Garety, Philippa; Freeman, Daniel; Kuipers, Elizabeth; Dunn, Graham; Smith, Ben; Bebbington, Paul E.

    2012-01-01

    The role of negative cognition and effect in maintaining psychotic symptoms is increasingly recognized but has yet to be substantiated though longitudinal analysis. Based on an a priori theoretical model, we hypothesized that negative cognition and depressed mood play a direct causal role in maintaining paranoia in people with psychosis and that the effect of mood is mediated by negative cognition. We used data from the 301 patients in the Prevention of Relapse in Psychosis Trial of cognitive behavior therapy. They were recruited from consecutive Community Mental Health Team clients presenting with a recent relapse of psychosis. The teams were located in inner and outer London and the rural county of Norfolk, England. The study followed a longitudinal cohort design, with initial measures repeated at 3 and 12 months. Structural equation modeling was used to investigate the direction of effect between negative cognition, depressed mood, and paranoia. Overall fit was ambiguous in some analyses and confounding by unidentified variables cannot be ruled out. Nevertheless, the most plausible models were those incorporating pathways from negative cognition and depressed mood to paranoid symptoms: There was no evidence whatsoever for pathways in the reverse direction. The link between depressed mood and paranoia appeared to be mediated by negative cognition. Our hypotheses were thus corroborated. This study provides evidence for the role of negative cognition in the maintenance of paranoia, a role of central relevance, both to the design of psychological interventions and to the conceptualizations of psychosis. PMID:21474550

  11. Generalized Linear Models of home activity for automatic detection of mild cognitive impairment in older adults.

    Science.gov (United States)

    Akl, Ahmad; Snoek, Jasper; Mihailidis, Alex

    2014-01-01

    With a globally aging population, the burden of care of cognitively impaired older adults is becoming increasingly concerning. Instances of Alzheimer's disease and other forms of dementia are becoming ever more frequent. Earlier detection of cognitive impairment offers significant benefits, but remains difficult to do in practice. In this paper, we develop statistical models of the behavior of older adults within their homes using sensor data in order to detect the early onset of cognitive decline. Specifically, we use inhomogenous Poisson processes to model the presence of subjects within different rooms throughout the day in the home using unobtrusive sensing technologies. We compare the distributions learned from cognitively intact and impaired subjects using information theoretic tools and observe statistical differences between the two populations which we believe can be used to help detect the onset of cognitive decline.

  12. Predicting recovery of cognitive function soon after stroke: differential modeling of logarithmic and linear regression.

    Science.gov (United States)

    Suzuki, Makoto; Sugimura, Yuko; Yamada, Sumio; Omori, Yoshitsugu; Miyamoto, Masaaki; Yamamoto, Jun-ichi

    2013-01-01

    Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE) scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R(2) = 0.676, Plinear regression modeling, R(2) = 0.598, P<0.0001). Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.

  13. Predicting recovery of cognitive function soon after stroke: differential modeling of logarithmic and linear regression.

    Directory of Open Access Journals (Sweden)

    Makoto Suzuki

    Full Text Available Cognitive disorders in the acute stage of stroke are common and are important independent predictors of adverse outcome in the long term. Despite the impact of cognitive disorders on both patients and their families, it is still difficult to predict the extent or duration of cognitive impairments. The objective of the present study was, therefore, to provide data on predicting the recovery of cognitive function soon after stroke by differential modeling with logarithmic and linear regression. This study included two rounds of data collection comprising 57 stroke patients enrolled in the first round for the purpose of identifying the time course of cognitive recovery in the early-phase group data, and 43 stroke patients in the second round for the purpose of ensuring that the correlation of the early-phase group data applied to the prediction of each individual's degree of cognitive recovery. In the first round, Mini-Mental State Examination (MMSE scores were assessed 3 times during hospitalization, and the scores were regressed on the logarithm and linear of time. In the second round, calculations of MMSE scores were made for the first two scoring times after admission to tailor the structures of logarithmic and linear regression formulae to fit an individual's degree of functional recovery. The time course of early-phase recovery for cognitive functions resembled both logarithmic and linear functions. However, MMSE scores sampled at two baseline points based on logarithmic regression modeling could estimate prediction of cognitive recovery more accurately than could linear regression modeling (logarithmic modeling, R(2 = 0.676, P<0.0001; linear regression modeling, R(2 = 0.598, P<0.0001. Logarithmic modeling based on MMSE scores could accurately predict the recovery of cognitive function soon after the occurrence of stroke. This logarithmic modeling with mathematical procedures is simple enough to be adopted in daily clinical practice.

  14. Corticonic models of brain mechanisms underlying cognition and intelligence

    Science.gov (United States)

    Farhat, Nabil H.

    The concern of this review is brain theory or more specifically, in its first part, a model of the cerebral cortex and the way it: (a) interacts with subcortical regions like the thalamus and the hippocampus to provide higher-level-brain functions that underlie cognition and intelligence, (b) handles and represents dynamical sensory patterns imposed by a constantly changing environment, (c) copes with the enormous number of such patterns encountered in a lifetime by means of dynamic memory that offers an immense number of stimulus-specific attractors for input patterns (stimuli) to select from, (d) selects an attractor through a process of “conjugation” of the input pattern with the dynamics of the thalamo-cortical loop, (e) distinguishes between redundant (structured) and non-redundant (random) inputs that are void of information, (f) can do categorical perception when there is access to vast associative memory laid out in the association cortex with the help of the hippocampus, and (g) makes use of “computation” at the edge of chaos and information driven annealing to achieve all this. Other features and implications of the concepts presented for the design of computational algorithms and machines with brain-like intelligence are also discussed. The material and results presented suggest, that a Parametrically Coupled Logistic Map network (PCLMN) is a minimal model of the thalamo-cortical complex and that marrying such a network to a suitable associative memory with re-entry or feedback forms a useful, albeit, abstract model of a cortical module of the brain that could facilitate building a simple artificial brain. In the second part of the review, the results of numerical simulations and drawn conclusions in the first part are linked to the most directly relevant works and views of other workers. What emerges is a picture of brain dynamics on the mesoscopic and macroscopic scales that gives a glimpse of the nature of the long sought after brain code

  15. Critical Path-Based Thread Placement for NUMA Systems

    Energy Technology Data Exchange (ETDEWEB)

    Su, C Y; Li, D; Nikolopoulos, D S; Grove, M; Cameron, K; de Supinski, B R

    2011-11-01

    Multicore multiprocessors use a Non Uniform Memory Architecture (NUMA) to improve their scalability. However, NUMA introduces performance penalties due to remote memory accesses. Without efficiently managing data layout and thread mapping to cores, scientific applications, even if they are optimized for NUMA, may suffer performance loss. In this paper, we present algorithms and a runtime system that optimize the execution of OpenMP applications on NUMA architectures. By collecting information from hardware counters, the runtime system directs thread placement and reduces performance penalties by minimizing the critical path of OpenMP parallel regions. The runtime system uses a scalable algorithm that derives placement decisions with negligible overhead. We evaluate our algorithms and runtime system with four NPB applications implemented in OpenMP. On average the algorithms achieve between 8.13% and 25.68% performance improvement compared to the default Linux thread placement scheme. The algorithms miss the optimal thread placement in only 8.9% of the cases.

  16. A multi-threading approach to secure VERIFYPIN

    CSIR Research Space (South Africa)

    Frieslaar, Ibraheem

    2016-10-01

    Full Text Available This research investigates the use of a multi-threaded framework as a software countermeasure mechanism to prevent attacks on the verifypin process in a pin-acceptance program. The implementation comprises of using various mathematical operations...

  17. Complexity Information Flow in a Multi-threaded Imperative Language

    CERN Document Server

    Marion, Jean-Yves

    2012-01-01

    We propose a type system to analyze the time consumed by multi-threaded imperative programs with a shared global memory, which delineates a class of safe multi-threaded programs. We demonstrate that a safe multi-threaded program runs in polynomial time if (i) it is strongly terminating wrt a non-deterministic scheduling policy or (ii) it terminates wrt a deterministic and quiet scheduling policy. As a consequence, we also characterize the set of polynomial time functions. The type system presented is based on the fundamental notion of data tiering, which is central in implicit computational complexity. It regulates the information flow in a computation. This aspect is interesting in that the type system bears a resemblance to typed based information flow analysis and notions of non-interference. As far as we know, this is the first characterization by a type system of polynomial time multi-threaded programs.

  18. Impact tolerance in mussel thread networks by heterogeneous material distribution

    Science.gov (United States)

    Qin, Zhao; Buehler, Markus J.

    2013-07-01

    The Mytilidae, generally known as marine mussels, are known to attach to most substrates including stone, wood, concrete and iron by using a network of byssus threads. Mussels are subjected to severe mechanical impacts caused by waves. However, how the network of byssus threads keeps the mussel attached in this challenging mechanical environment is puzzling, as the dynamical forces far exceed the measured strength of byssus threads and their attachment to the environment. Here we combine experiment and simulation, and show that the heterogeneous material distribution in byssus threads has a critical role in decreasing the effect of impact loading. We find that a combination of stiff and soft materials at an 80:20 ratio enables mussels to rapidly and effectively dissipate impact energy. Notably, this facilitates a significantly enhanced strength under dynamical loading over 900% that of the strength under static loading.

  19. Modeling of cognitive impairment by disease duration in multiple sclerosis: a cross-sectional study.

    Directory of Open Access Journals (Sweden)

    Anat Achiron

    Full Text Available BACKGROUND/AIMS: Large-scale population studies measuring rates and dynamics of cognitive decline in multiple sclerosis (MS are lacking. In the current cross-sectional study we evaluated the patterns of cognitive impairment in MS patients with disease duration of up to 30 years. METHODS: 1,500 patients with MS were assessed by a computerized cognitive battery measuring verbal and non-verbal memory, executive function, visual spatial perception, verbal function, attention, information processing speed and motor skills. Cognitive impairment was defined as below one standard deviation (SD and severe cognitive impairment as below 2SD for age and education matched healthy population norms. RESULTS: Cognitive performance in our cohort was poorer than healthy population norms. The most frequently impaired domains were information processing speed and executive function. MS patients with secondary-progressive disease course performed poorly compared with clinically isolated syndrome, relapsing-remitting and primary progressive MS patients. By the fifth year from disease onset, 20.9% of patients performed below the 1SD cutoff for impairment, p=0.005, and 6.0% performed below the 2SD cutoff for severe cognitive impairment, p=0.002. By 10 years from onset 29.3% and 9.0% of patients performed below the 1SD and 2SD cutoffs, respectively, p=0.0001. Regression modeling suggested that cognitive impairment may precede MS onset by 1.2 years. CONCLUSIONS: The rates of cognitive impairment in this large sample of MS patients were lower than previously reported and severe cognitive impairment was evident only in a relatively small group of patients. Cognitive impairment differed significantly from expected normal distribution only at five years from onset, suggesting the existence of a therapeutic window during which patients may benefit from interventions to maintain cognitive health.

  20. Software Thread Integration and Synthesis for Real-Time Applications

    OpenAIRE

    Dean, Alexander G.

    2005-01-01

    Submitted on behalf of EDAA (http://www.edaa.com/); International audience; Software Thread Integration (STI) and Asynchronous STI (ASTI) are compiler techniques which interleave functions from separate program threads at the assembly language level, creating implicitly multithreaded functions which provide low-cost concurrency on generic hardware. This extends the reach of software and reduces the need to rely upon dedicated hardware. STI and ASTI are driven by two types of timing requiremen...

  1. Star graphs: threaded distance trees and E-sets

    CERN Document Server

    Dejter, Italo J

    2010-01-01

    The distribution of distances in the star graph $ST_n$, ($1threaded binary tree is obtained that realizes an orientation of $ST_n$ whose levels are given by the distances to the identity permutation, via a pruning algorithm followed by a threading algorithm. In the process, the distributions of distances of the efficient dominating sets of $ST_n$ are determined.

  2. Extending the Scope of the Acculturation/Pidginization Model to Include Cognition.

    Science.gov (United States)

    Schumann, John H.

    1990-01-01

    Examines five cognitive models for second-language acquisition (SLA) and assesses how each might account for the Pidginized interlanguage found in the early stages of second-language acquisition. (23 references) (JL)

  3. Teachers’ individual action theories about competence-based education: the value of the cognitive apprenticeship model

    OpenAIRE

    2009-01-01

    Seezink, A., Poell, R. F., & Kirschner, P. A. (2009). Teachers' individual action theories about competence-based education: The value of the cognitive apprenticeship model. Journal of Vocational Education & Training, 61, 203-215.

  4. Testing the Validity of a Cognitive Behavioral Model for Gambling Behavior.

    Science.gov (United States)

    Raylu, Namrata; Oei, Tian Po S; Loo, Jasmine M Y; Tsai, Jung-Shun

    2016-06-01

    Currently, cognitive behavioral therapies appear to be one of the most studied treatments for gambling problems and studies show it is effective in treating gambling problems. However, cognitive behavior models have not been widely tested using statistical means. Thus, the aim of this study was to test the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior using structural equation modeling (AMOS 20). Several questionnaires assessing a range of gambling specific variables (e.g., gambling urges, cognitions and behaviors) and gambling correlates (e.g., psychological states, and coping styles) were distributed to 969 participants from the community. Results showed that negative psychological states (i.e., depression, anxiety and stress) only directly predicted gambling behavior, whereas gambling urges predicted gambling behavior directly as well as indirectly via gambling cognitions. Avoidance coping predicted gambling behavior only indirectly via gambling cognitions. Negative psychological states were significantly related to gambling cognitions as well as avoidance coping. In addition, significant gender differences were also found. The results provided confirmation for the validity of the pathways postulated in the cognitive behavioral theory of gambling behavior. It also highlighted the importance of gender differences in conceptualizing gambling behavior.

  5. Digital terrain model generalization incorporating scale, semantic and cognitive constraints

    Science.gov (United States)

    Partsinevelos, Panagiotis; Papadogiorgaki, Maria

    2014-05-01

    Cartographic generalization is a well-known process accommodating spatial data compression, visualization and comprehension under various scales. In the last few years, there are several international attempts to construct tangible GIS systems, forming real 3D surfaces using a vast number of mechanical parts along a matrix formation (i.e., bars, pistons, vacuums). Usually, moving bars upon a structured grid push a stretching membrane resulting in a smooth visualization for a given surface. Most of these attempts suffer either in their cost, accuracy, resolution and/or speed. Under this perspective, the present study proposes a surface generalization process that incorporates intrinsic constrains of tangible GIS systems including robotic-motor movement and surface stretching limitations. The main objective is to provide optimized visualizations of 3D digital terrain models with minimum loss of information. That is, to minimize the number of pixels in a raster dataset used to define a DTM, while reserving the surface information. This neighborhood type of pixel relations adheres to the basics of Self Organizing Map (SOM) artificial neural networks, which are often used for information abstraction since they are indicative of intrinsic statistical features contained in the input patterns and provide concise and characteristic representations. Nevertheless, SOM remains more like a black box procedure not capable to cope with possible particularities and semantics of the application at hand. E.g. for coastal monitoring applications, the near - coast areas, surrounding mountains and lakes are more important than other features and generalization should be "biased"-stratified to fulfill this requirement. Moreover, according to the application objectives, we extend the SOM algorithm to incorporate special types of information generalization by differentiating the underlying strategy based on topologic information of the objects included in the application. The final

  6. Redoable Tie-Over Dressing Using Multiple Loop Silk Threads

    Directory of Open Access Journals (Sweden)

    Hyeon Jong Jo

    2013-05-01

    Full Text Available After skin grafting, to prevent hematoma or seroma collection at the graft site, a tie-over dressing has been commonly used. However, although the conventional tie-over dressing by suture is a useful method for securing a graft site, refixation is difficult when repeated tieover dressing is needed. Therefore, we recommend a redoable tie-over dressing technique with multiple loops threads and connecting silk threads. After the raw surface of each of our cases was covered with a skin graft, multiple loop silk thread attached with nylon at the skin graft margin. We applied the ointment gauze and wet cotton/fluffy gauze over the skin graft, then fixed the dressing by connecting cross-counter multiple loop thread with connecting silk threads. When we opened the tie-over dressing by cutting the connecting silk threads, we repeated the tie-over dressing with the same method. The skin graft was taken successfully without hematoma or seroma collection or any other complications. In conclusion, we report a novel tie-over dressing enabling simple fixation of the dressing to maintain proper tension for wounds that require repetitive fixation. Further, with this reliable method, the skin grafts were well taken.

  7. Redoable tie-over dressing using multiple loop silk threads.

    Science.gov (United States)

    Jo, Hyeon Jong; Kim, Jun Sik; Kim, Nam Gyun; Lee, Kyung Suk; Choi, Jae Hoon

    2013-05-01

    After skin grafting, to prevent hematoma or seroma collection at the graft site, a tie-over dressing has been commonly used. However, although the conventional tie-over dressing by suture is a useful method for securing a graft site, refixation is difficult when repeated tie-over dressing is needed. Therefore, we recommend a redoable tie-over dressing technique with multiple loops threads and connecting silk threads. After the raw surface of each of our cases was covered with a skin graft, multiple loop silk thread attached with nylon at the skin graft margin. We applied the ointment gauze and wet cotton/fluffy gauze over the skin graft, then fixed the dressing by connecting cross-counter multiple loop thread with connecting silk threads. When we opened the tie-over dressing by cutting the connecting silk threads, we repeated the tie-over dressing with the same method. The skin graft was taken successfully without hematoma or seroma collection or any other complications. In conclusion, we report a novel tie-over dressing enabling simple fixation of the dressing to maintain proper tension for wounds that require repetitive fixation. Further, with this reliable method, the skin grafts were well taken.

  8. Multi-threaded Software Framework Development for the ATLAS Experiment

    CERN Document Server

    Stewart, Graeme; The ATLAS collaboration; Baines, John; Calafiura, Paolo; Dotti, Andrea; Farrell, Steven; Leggett, Charles; Malon, David; Ritsch, Elmar; Snyder, Scott; Tsulaia, Vakhtang; van Gemmeren, Peter; Wynne, Benjamin

    2016-01-01

    ATLAS's current software framework, Gaudi/Athena, has been very successful for the experiment in LHC Runs 1 and 2. However, its single threaded design has been recognised for some time to be increasingly problematic as CPUs have increased core counts and decreased available memory per core. Even the multi-process version of Athena, AthenaMP, will not scale to the range of architectures we expect to use beyond Run2. ATLAS examined the requirements on an updated multi-threaded framework and layed out plans for a new framework, including better support for high level trigger (HLT) use cases, in 2014. In this paper we report on our progress in developing the new multi-threaded task parallel extension of Athena, AthenaMT. Implementing AthenaMT has required many significant code changes. Progress has been made in updating key concepts of the framework, to allow the incorporation of different levels of thread safety in algorithmic code (from un-migrated thread-unsafe code, to thread safe copyable code to reentrant c...

  9. Multi-threaded software framework development for the ATLAS experiment

    CERN Document Server

    AUTHOR|(INSPIRE)INSPIRE-00226135; Baines, John; Bold, Tomasz; Calafiura, Paolo; Dotti, Andrea; Farrell, Steven; Leggett, Charles; Malon, David; Ritsch, Elmar; Snyder, Scott; Tsulaia, Vakhtang; van Gemmeren, Peter; Wynne, Benjamin

    2016-01-01

    ATLAS's current software framework, Gaudi/Athena, has been very successful for the experiment in LHC Runs 1 and 2. However, its single threaded design has been recognised for some time to be increasingly problematic as CPUs have increased core counts and decreased available memory per core. Even the multi-process version of Athena, AthenaMP, will not scale to the range of architectures we expect to use beyond Run2. ATLAS examined the requirements on an updated multi-threaded framework and laid out plans for a new framework, including better support for high level trigger (HLT) use cases, in 2014. In this paper we report on our progress in developing the new multi-threaded task parallel extension of Athena, AthenaMT. Implementing AthenaMT has required many significant code changes. Progress has been made in updating key concepts of the framework, to allow the incorporation of different levels of thread safety in algorithmic code (from un-migrated thread-unsafe code, to thread safe copyable code to reentrant co...

  10. Modelling Human Cognitive Development with Explanation-Based Learning in Soar

    Science.gov (United States)

    1990-02-02

    of Pittsburgh BEST AVAILABLE COPY AXpprovedI for public rleaw4: distributimi unintilieu. 90 Z:L 0 Q3 7 MODELLING HUMAN COGNITIVE DEVELOPMENT WITH...NO. No. ACCESSION NO N/A N/A N/A N/A I I TITLE (*XcA* SecsaiY O7fiCatl) Modelling human cognitive development with explanation-bsed learning in Soar...P I cognitive development Soar I I I j~n--qq~ learning 19. ABSTRACT (Continue on reverse if noeessary and identy by block -number) SEE REVERSE SIDE 20

  11. Cognitive/emotional models for human behavior representation in 3D avatar simulations

    Science.gov (United States)

    Peterson, James K.

    2004-08-01

    Simplified models of human cognition and emotional response are presented which are based on models of auditory/ visual polymodal fusion. At the core of these models is a computational model of Area 37 of the temporal cortex which is based on new isocortex models presented recently by Grossberg. These models are trained using carefully chosen auditory (musical sequences), visual (paintings) and higher level abstract (meta level) data obtained from studies of how optimization strategies are chosen in response to outside managerial inputs. The software modules developed are then used as inputs to character generation codes in standard 3D virtual world simulations. The auditory and visual training data also enable the development of simple music and painting composition generators which significantly enhance one's ability to validate the cognitive model. The cognitive models are handled as interacting software agents implemented as CORBA objects to allow the use of multiple language coding choices (C++, Java, Python etc) and efficient use of legacy code.

  12. Stakeholder approach, Stakeholders mental model: A visualization test with cognitive mapping technique

    Directory of Open Access Journals (Sweden)

    Garoui Nassreddine

    2012-04-01

    Full Text Available The idea of this paper is to determine the mental models of actors in the firm with respect to the stakeholder approach of corporate governance. The use of the cognitive map to view these diagrams to show the ways of thinking and conceptualization of the stakeholder approach. The paper takes a corporate governance perspective, discusses stakeholder model. It takes also a cognitive mapping technique.

  13. The Past, Present, and Future of Computational Models of Cognitive Development

    Science.gov (United States)

    Schlesinger, Matthew; McMurray, Bob

    2012-01-01

    Does modeling matter? We address this question by providing a broad survey of the computational models of cognitive development that have been proposed and studied over the last three decades. We begin by noting the advantages and limitations of computational models. We then describe four key dimensions across which models of development can be…

  14. The Past, Present, and Future of Computational Models of Cognitive Development

    Science.gov (United States)

    Schlesinger, Matthew; McMurray, Bob

    2012-01-01

    Does modeling matter? We address this question by providing a broad survey of the computational models of cognitive development that have been proposed and studied over the last three decades. We begin by noting the advantages and limitations of computational models. We then describe four key dimensions across which models of development can be…

  15. A Comparative Structural Equation Modeling Investigation of the Relationships among Teaching, Cognitive and Social Presence

    Science.gov (United States)

    Kozan, Kadir

    2016-01-01

    The present study investigated the relationships among teaching, cognitive, and social presence through several structural equation models to see which model would better fit the data. To this end, the present study employed and compared several different structural equation models because different models could fit the data equally well. Among…

  16. Retrofitting Non-Cognitive-Diagnostic Reading Assessment under the Generalized DINA Model Framework

    Science.gov (United States)

    Chen, Huilin; Chen, Jinsong

    2016-01-01

    Cognitive diagnosis models (CDMs) are psychometric models developed mainly to assess examinees' specific strengths and weaknesses in a set of skills or attributes within a domain. By adopting the Generalized-DINA model framework, the recently developed general modeling framework, we attempted to retrofit the PISA reading assessments, a…

  17. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

  18. The Utility of Cognitive Plausibility in Language Acquisition Modeling: Evidence from Word Segmentation

    Science.gov (United States)

    Phillips, Lawrence; Pearl, Lisa

    2015-01-01

    The informativity of a computational model of language acquisition is directly related to how closely it approximates the actual acquisition task, sometimes referred to as the model's "cognitive plausibility." We suggest that though every computational model necessarily idealizes the modeled task, an informative language acquisition…

  19. On the Effect of Thread Turn Profile Angle of the Planetary Roller-Screw Mechanism Parts on Their Basic Parameters

    Directory of Open Access Journals (Sweden)

    D. S. Blinov

    2016-01-01

    Full Text Available One of the most important trends in mechanical engineering development is the constant improvement of load capacity of machines, mechanisms, units and parts without increasing their overall dimensions and weight. This is also true for today’s most prospective planetary rollerscrew mechanisms (PRSM converting motion from rotary to linear type. The problem of PRSM load capacity improvement deserves more attention, because these mechanisms have very high performance characteristics, which leads to problems in the choice of support devices for these mechanisms.However, for many mechanical engineering industries it is important to decrease the PRSMs weight and dimensions, or to improve their reliability and durability. This has led to finding the reserves for improving the PRSM load capacity by decreasing the thread turn profile angle, α, of PRSM threaded parts, as compared to α = 90° in traditional mechanisms. When PRSM calculation methods were developed, it was decided to use α = 90° for transforming the mechanism parts into a physical model and a design pattern. It allowed us to reduce the PRSM designing to well-known roller bearing designing based on very extensive experimental data.Proposed PRSM designs do not contradict to accepted physical models and design patterns – they just have different basic characteristics of PRSM, i.e. static and dynamic load ratings. Proposed PRSM designs with a thread turn profile angle α=70° on their parts allow to increase the load capacity by 15%, as compared to traditional PRSMs, which have threaded parts with a thread turn profile angle α = 90°. There are two factors, which can improve the PRSM load capacity. The first one is the decrease of normal force between mating thread turns of a screw and a roller with the same operational axial force. The second one is the increase of the radius of the shaped profile of a roller thread turn resulting in the expansion of the contact area pattern between the

  20. Efficacy of cognitive rehabilitation therapies for mild cognitive impairment (MCI) in older adults: working toward a theoretical model and evidence-based interventions.

    Science.gov (United States)

    Huckans, Marilyn; Hutson, Lee; Twamley, Elizabeth; Jak, Amy; Kaye, Jeffrey; Storzbach, Daniel

    2013-03-01

    To evaluate the efficacy of cognitive rehabilitation therapies (CRTs) for mild cognitive impairment (MCI). Our review revealed a need for evidence-based treatments for MCI and a lack of a theoretical rehabilitation model to guide the development and evaluation of these interventions. We have thus proposed a theoretical rehabilitation model of MCI that yields key intervention targets-cognitive compromise, functional compromise, neuropsychiatric symptoms, and modifiable risk and protective factors known to be associated with MCI and dementia. Our model additionally defines specific cognitive rehabilitation approaches that may directly or indirectly target key outcomes-restorative cognitive training, compensatory cognitive training, lifestyle interventions, and psychotherapeutic techniques. Fourteen randomized controlled trials met inclusion criteria and were reviewed. Studies markedly varied in terms of intervention approaches and selected outcome measures and were frequently hampered by design limitations. The bulk of the evidence suggested that CRTs can change targeted behaviors in individuals with MCI and that CRTs are associated with improvements in objective cognitive performance, but the pattern of effects on specific cognitive domains was inconsistent across studies. Other important outcomes (i.e., daily functioning, quality of life, neuropsychiatric symptom severity) were infrequently assessed across studies. Few studies evaluated long-term outcomes or the impact of CRTs on conversion rates from MCI to dementia or normal cognition. Overall, results from trials are promising but inconclusive. Additional well-designed and adequately powered trials are warranted and required before CRTs for MCI can be considered evidence-based.

  1. A DYNAMIC-SYSTEMS MODEL OF COGNITIVE AND LANGUAGE GROWTH

    NARCIS (Netherlands)

    VANGEERT, P

    In the first part of the article, a conceptual framework is sketched to define cognitive growth, including language growth, as a process of growth under limited resources. Important concepts are the process, level, and rate of growth; minimal structural growth level; carrying capacity and unutilized

  2. Formal modeling and analysis of cognitive agent behavior

    NARCIS (Netherlands)

    Sharpanskykh, Alexei; Treur, Jan

    2007-01-01

    From an external perspective, cognitive agent behavior can be described by specifying (temporal) correlations of a certain complexity between stimuli (input states) and (re)actions (output states) of the agent. From an internal perspective the agent’s dynamics can be characterized by direct (causa

  3. Empirical Network Model of Human Higher Cognitive Brain Functions

    Science.gov (United States)

    1990-03-31

    EEG potentials during cognition. Science. 1981. 213: 918-921- and mental activity in juvenile delinquents. Electroenceph. Gevns, .A.S.. Schafier. R.F...their latency and topography depend on the moda - litv. intensity, and other physical properties of the stimulus. The P100 and NIO0 peaks are also

  4. Modeling Cognitive Strategies during Complex Task Performing Process

    Science.gov (United States)

    Mazman, Sacide Guzin; Altun, Arif

    2012-01-01

    The purpose of this study is to examine individuals' computer based complex task performing processes and strategies in order to determine the reasons of failure by cognitive task analysis method and cued retrospective think aloud with eye movement data. Study group was five senior students from Computer Education and Instructional Technologies…

  5. DOORS English--The Cognitive Basis of Rhetorical Models.

    Science.gov (United States)

    Taylor, Karl K.

    1979-01-01

    The Development of Operational Reasoning Skills (DOORS) program at Illinois Central College is an interdisciplinary experiment that guides students from concrete to formal operational levels of thought to ensure that they understand the concepts and cognitive skills undergirding the rhetorical modes. (RL)

  6. How does rumination impact cognition? A first mechanistic model.

    NARCIS (Netherlands)

    van Vugt, Marieke; van der Velde, Maarten; van Vugt, Marieke; Banks, Adrian P; Kennedy, William G

    2017-01-01

    Rumination is a process of uncontrolled, narrowly-foused neg- ative thinking that is often self-referential, and that is a hall- mark of depression. Despite its importance, little is known about its cognitive mechanisms. Rumination can be thought of as a specific, constrained form of mind-wandering.

  7. Learning online community citizenship behavior: a socio-cognitive model.

    Science.gov (United States)

    Joe, Sheng-Wuu; Lin, Chieh-Peng

    2008-06-01

    This study postulates personal and environmental factors as key drivers of online community citizenship behavior (OCCB). OCCB reveals that the individual chooses to perform a behavior that is beneficial to others. Empirical results confirm the applicability of social cognitive theory (SCT) in online communities.

  8. Architectural considerations for modeling cognitive-emotional decision making

    NARCIS (Netherlands)

    Lotens, W.A.; Cain, B.

    2013-01-01

    There are numerous conceptual similarities between affective and rational decision making functions despite the differences between the emotional and cognitive systems. Aspects of emotion may be considered as a concurrent stream of information processing that is coupled with explicit, rational infor

  9. Does attainment of Piaget's formal operational level of cognitive development predict student understanding of scientific models?

    Science.gov (United States)

    Lahti, Richard Dennis, II

    Knowledge of scientific models and their uses is a concept that has become a key benchmark in many of the science standards of the past 30 years, including the proposed Next Generation Science Standards. Knowledge of models is linked to other important nature of science concepts such as theory change which are also rising in prominence in newer standards. Effective methods of instruction will need to be developed to enable students to achieve these standards. The literature reveals an inconsistent history of success with modeling education. These same studies point to a possible cognitive development component which might explain why some students succeeded and others failed. An environmental science course, rich in modeling experiences, was used to test both the extent to which knowledge of models and modeling could be improved over the course of one semester, and more importantly, to identify if cognitive ability was related to this improvement. In addition, nature of science knowledge, particularly related to theories and theory change, was also examined. Pretest and posttest results on modeling (SUMS) and nature of science (SUSSI), as well as data from the modeling activities themselves, was collected. Cognitive ability was measured (CTSR) as a covariate. Students' gain in six of seven categories of modeling knowledge was at least medium (Cohen's d >.5) and moderately correlated to CTSR for two of seven categories. Nature of science gains were smaller, although more strongly correlated with CTSR. Student success at creating a model was related to CTSR, significantly in three of five sub-categories. These results suggest that explicit, reflective experience with models can increase student knowledge of models and modeling (although higher cognitive ability students may have more success), but successfully creating models may depend more heavily on cognitive ability. This finding in particular has implications in the grade placement of modeling standards and

  10. Thread selection according to power characteristics during context switching on compute nodes

    Energy Technology Data Exchange (ETDEWEB)

    Archer, Charles J.; Blocksome, Michael A.; Randles, Amanda E.; Ratterman, Joseph D.; Smith, Brian E.

    2016-10-04

    Methods, apparatus, and products are disclosed for thread selection during context switching on a plurality of compute nodes that includes: executing, by a compute node, an application using a plurality of threads of execution, including executing one or more of the threads of execution; selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads; determining, by the compute node, whether criteria for a thread context switch are satisfied; and performing, by the compute node, the thread context switch if the criteria for a thread context switch are satisfied, including executing the next thread of execution.

  11. Thread selection according to predefined power characteristics during context switching on compute nodes

    Science.gov (United States)

    None, None

    2013-06-04

    Methods, apparatus, and products are disclosed for thread selection during context switching on a plurality of compute nodes that includes: executing, by a compute node, an application using a plurality of threads of execution, including executing one or more of the threads of execution; selecting, by the compute node from a plurality of available threads of execution for the application, a next thread of execution in dependence upon power characteristics for each of the available threads; determining, by the compute node, whether criteria for a thread context switch are satisfied; and performing, by the compute node, the thread context switch if the criteria for a thread context switch are satisfied, including executing the next thread of execution.

  12. Influence of fine threads and platform-switching on crestal bone stress around implant-a three-dimensional finite element analysis.

    Science.gov (United States)

    Khurana, Pardeep; Sharma, Arun; Sodhi, Kiranmeet Kaur

    2013-12-01

    The aims of this study were to investigate the effect of implant fine threads on crestal bone stress compared to a standard smooth implant collar and to analyze how different abutment diameters influenced the crestal bone stress level. Three-dimensional finite element imaging was used to create a cross-sectional model in SolidWorks 2007 software of an implant (5-mm platform and 10 mm in length) placed in the premolar region of the mandible. The implant model was created to resemble a commercially available fine thread implant. Abutments of different diameters (5.0 mm: standard, 4.5 mm, 4.0 mm, and 3.5 mm) were loaded with a force of 100 N at 90° vertical and 40° oblique angles. Finite element analysis was done in COSMOSWorks software, which was used to analyze the stress patterns in bone, especially in the crestal region. Upon loading, the fine thread implant model had greater stress at the crestal bone adjacent to the implant than the smooth neck implant in both vertical and oblique loading. When the abutment diameter decreased progressively from 5.0 mm to 4.5 mm to 4 mm and to 3.5 mm the thread model showed a reduction of stress at the crestal bone level from 23.2 MPa to 15.02 MPa for fine thread and from 22.7 to 13.5 MPa for smooth collar implant group after vertical loading and from 43.7 MPa to 33.1 MPa in fine thread model and from 36.9 to 20.5 MPa in smooth collar implant model after oblique loading. Fine threads increase crestal stress upon loading. Reduced abutment diameter that is platform switching resulted in less stress translated to the crestal bone in the fine thread and smooth neck.

  13. Putative cognitive enhancers in preclinical models related to schizophrenia: the search for an elusive target.

    Science.gov (United States)

    Barak, Segev; Weiner, Ina

    2011-08-01

    Several developments have converged to drive what may be called "the cognitive revolution" in drug discovery in schizophrenia (SCZ), including the emphasis on cognitive deficits as a core disabling aspect of SCZ, the increasing consensus that cognitive deficits are not treated satisfactorily by the available antipsychotic drugs (APDs), and the failure of animal models to predict drug efficacy for cognitive deficits in clinical trials. Consequently, in recent years, a paradigm shift has been encouraged in animal modeling, triggered by the NIMH sponsored Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative, and intended to promote the development and use of behavioral measures in animals that can generate valid (clinically relevant) measures of cognition and thus promote the identification of cognition enhancers for SCZ. Here, we provide a non-exhaustive survey of the effects of putative cognition enhancers (PCEs) representing 10 pharmacological targets as well as antipsychotic drugs (APDs), on SCZ-mimetic drugs (NMDA antagonists, muscarinic antagonist scopolamine and dopaminergic agonist amphetamine), in several tasks considered to measure cognitive processes/domains that are disrupted in SCZ (the five choice serial reaction time task, sustain attention task, working and/or recognition memory (delayed (non)matching to sample, delayed alternation task, radial arm maze, novel object recognition), reversal learning, attentional set shifting, latent inhibition and spatial learning and memory). We conclude that most of the available models have no capacity to distinguish between PCEs and APDs and that there is a need to establish models based on tasks whose perturbations lead to performance impairments that are resistant to APDs, and/or to accept APDs as a "weak gold standard". Several directions derived from the surveyed data are suggested.

  14. Multi-threaded, discrete event simulation of distributed computing systems

    Science.gov (United States)

    Legrand, Iosif; MONARC Collaboration

    2001-10-01

    The LHC experiments have envisaged computing systems of unprecedented complexity, for which is necessary to provide a realistic description and modeling of data access patterns, and of many jobs running concurrently on large scale distributed systems and exchanging very large amounts of data. A process oriented approach for discrete event simulation is well suited to describe various activities running concurrently, as well the stochastic arrival patterns specific for such type of simulation. Threaded objects or "Active Objects" can provide a natural way to map the specific behaviour of distributed data processing into the simulation program. The simulation tool developed within MONARC is based on Java (TM) technology which provides adequate tools for developing a flexible and distributed process oriented simulation. Proper graphics tools, and ways to analyze data interactively, are essential in any simulation project. The design elements, status and features of the MONARC simulation tool are presented. The program allows realistic modeling of complex data access patterns by multiple concurrent users in large scale computing systems in a wide range of possible architectures, from centralized to highly distributed. Comparison between queuing theory and realistic client-server measurements is also presented.

  15. Dynamic mechanistic explanation: computational modeling of circadian rhythms as an exemplar for cognitive science.

    Science.gov (United States)

    Bechtel, William; Abrahamsen, Adele

    2010-09-01

    We consider computational modeling in two fields: chronobiology and cognitive science. In circadian rhythm models, variables generally correspond to properties of parts and operations of the responsible mechanism. A computational model of this complex mechanism is grounded in empirical discoveries and contributes a more refined understanding of the dynamics of its behavior. In cognitive science, on the other hand, computational modelers typically advance de novo proposals for mechanisms to account for behavior. They offer indirect evidence that a proposed mechanism is adequate to produce particular behavioral data, but typically there is no direct empirical evidence for the hypothesized parts and operations. Models in these two fields differ in the extent of their empirical grounding, but they share the goal of achieving dynamic mechanistic explanation. That is, they augment a proposed mechanistic explanation with a computational model that enables exploration of the mechanism's dynamics. Using exemplars from circadian rhythm research, we extract six specific contributions provided by computational models. We then examine cognitive science models to determine how well they make the same types of contributions. We suggest that the modeling approach used in circadian research may prove useful in cognitive science as researchers develop procedures for experimentally decomposing cognitive mechanisms into parts and operations and begin to understand their nonlinear interactions.

  16. Product evolutionary design spirally guided by double threads%双线程螺旋导向式产品进化设计

    Institute of Scientific and Technical Information of China (English)

    陈卫敏; 李彦; 李文强; 杨琨

    2015-01-01

    In order to adapt to the dynamic changes of market demands, the ecological relationship of food chain was introduced into product conceptual design, the relations of products are systematically classified at a cognitive level as competition relation and symbiotic cooperation relation. These relations laid a foundation to systematically realize the spirally guide by double threads. Products need evolving from low level to high level to gradually adapt to the dynamic change of market environment which is similar to biological evolution, so products were classified based on the market, and product evolutionary chain and product symbiotic ring were built from junior to senior in accordance with the food chain relationship. Products in the process of evolution present the dynamic characteristics of spiral evolution under the dual function of radial symbiotic ring and axial evolutionary chain at the same time, the design methods and models guiding product evolution by double threads of competition and cooperation was put forward based on the analysis of the dynamic product evolution information. Applying components control template method between design objectives and competitors, In both applying properties related template method between design objectives and symbiotic objectives, the whole process of evolution design was guided by the competitive information and symbiotic information in the model, which make products evolution purposefully. This paper implement the testing and pushing of evolution degree step by step based on the evolutionary genetic algorithm, which guaranteed the rationality and adaptability of each product layer evolution process in the model. According to the practical innovation design conditions, the competition effect and symbiotic role in the process of evolution. The model spirally guided by double threads can dynamically and flexibly yield a total evolutionary scheme feasible for the desired product. The model spirally guided by double

  17. Aspects of Piaget's cognitive developmental psychology and neurobiology of psychotic disorders - an integrative model.

    Science.gov (United States)

    Gebhardt, Stefan; Grant, Phillip; von Georgi, Richard; Huber, Martin T

    2008-09-01

    Psychological, neurobiological and neurodevelopmental approaches have frequently been used to provide pathogenic concepts on psychotic disorders. However, aspects of cognitive developmental psychology have hardly been considered in current models. Using a hypothesis-generating approach an integration of these concepts was conducted. According to Piaget (1896-1980), assimilation and accommodation as forms of maintenance and modification of cognitive schemata represent fundamental processes of the brain. In general, based on the perceived input stimuli, cognitive schemata are developed resulting in a conception of the world, the realistic validity and the actuality of which is still being controlled and modified by cognitive adjustment processes. In psychotic disorders, however, a disproportion of environmental demands and the ability to activate required neuronal adaptation processes occurs. We therefore hypothesize a failure of the adjustment of real and requested output patterns. As a consequence autonomous cognitive schemata are generated, which fail to adjust with reality resulting in psychotic symptomatology. Neurobiological, especially neuromodulatory and neuroplastic processes play a central role in these perceptive and cognitive processes. In conclusion, integration of cognitive developmental psychology into the existing pathogenic concepts of psychotic disorders leads to interesting insights into basic disease mechanisms and also guides future research in the cognitive neuroscience of such disorders.

  18. Error-preceding brain activity reflects (mal-)adaptive adjustments of cognitive control: a modeling study.

    Science.gov (United States)

    Steinhauser, Marco; Eichele, Heike; Juvodden, Hilde T; Huster, Rene J; Ullsperger, Markus; Eichele, Tom

    2012-01-01

    Errors in choice tasks are preceded by gradual changes in brain activity presumably related to fluctuations in cognitive control that promote the occurrence of errors. In the present paper, we use connectionist modeling to explore the hypothesis that these fluctuations reflect (mal-)adaptive adjustments of cognitive control. We considered ERP data from a study in which the probability of conflict in an Eriksen-flanker task was manipulated in sub-blocks of trials. Errors in these data were preceded by a gradual decline of N2 amplitude. After fitting a connectionist model of conflict adaptation to the data, we analyzed simulated N2 amplitude, simulated response times (RTs), and stimulus history preceding errors in the model, and found that the model produced the same pattern as obtained in the empirical data. Moreover, this pattern is not found in alternative models in which cognitive control varies randomly or in an oscillating manner. Our simulations suggest that the decline of N2 amplitude preceding errors reflects an increasing adaptation of cognitive control to specific task demands, which leads to an error when these task demands change. Taken together, these results provide evidence that error-preceding brain activity can reflect adaptive adjustments rather than unsystematic fluctuations of cognitive control, and therefore, that these errors are actually a consequence of the adaptiveness of human cognition.

  19. OpenGeoSys-GEMS: Hybrid parallelization of a reactive transport code with MPI and threads

    Science.gov (United States)

    Kosakowski, G.; Kulik, D. A.; Shao, H.

    2012-04-01

    OpenGeoSys-GEMS is a generic purpose reactive transport code based on the operator splitting approach. The code couples the Finite-Element groundwater flow and multi-species transport modules of the OpenGeoSys (OGS) project (http://www.ufz.de/index.php?en=18345) with the GEM-Selektor research package to model thermodynamic equilibrium of aquatic (geo)chemical systems utilizing the Gibbs Energy Minimization approach (http://gems.web.psi.ch/). The combination of OGS and the GEM-Selektor kernel (GEMS3K) is highly flexible due to the object-oriented modular code structures and the well defined (memory based) data exchange modules. Like other reactive transport codes, the practical applicability of OGS-GEMS is often hampered by the long calculation time and large memory requirements. • For realistic geochemical systems which might include dozens of mineral phases and several (non-ideal) solid solutions the time needed to solve the chemical system with GEMS3K may increase exceptionally. • The codes are coupled in a sequential non-iterative loop. In order to keep the accuracy, the time step size is restricted. In combination with a fine spatial discretization the time step size may become very small which increases calculation times drastically even for small 1D problems. • The current version of OGS is not optimized for memory use and the MPI version of OGS does not distribute data between nodes. Even for moderately small 2D problems the number of MPI processes that fit into memory of up-to-date workstations or HPC hardware is limited. One strategy to overcome the above mentioned restrictions of OGS-GEMS is to parallelize the coupled code. For OGS a parallelized version already exists. It is based on a domain decomposition method implemented with MPI and provides a parallel solver for fluid and mass transport processes. In the coupled code, after solving fluid flow and solute transport, geochemical calculations are done in form of a central loop over all finite

  20. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive level.

    Science.gov (United States)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc; Angstmann, Steffen; Karabanov, Anke; Raffin, Estelle; Thielscher, Axel; Siebner, Hartwig Roman

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how these approaches advance the scientific potential of NTBS as an interventional tool in cognitive neuroscience. (i) Leveraging the anatomical information provided by structural imaging, the electric field distribution in the brain can be modeled and simulated. Biophysical modeling approaches generate testable predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can be used to construct causal network models. These models can identify spatiotemporal changes in effective connectivity during distinct cognitive states and allow for examining how effective connectivity is shaped by NTBS. (iii) Modeling the NTBS effects based on neuroimaging can be complemented by behavior-based cognitive models that exploit variations in task performance. For instance, NTBS-induced changes in response speed and accuracy can be explicitly modeled in a cognitive framework accounting for the speed-accuracy trade-off. This enables to dissociate between behavioral NTBS effects that emerge in the context of rapid automatic responses or in the context of slow deliberate responses. We argue that these complementary modeling approaches facilitate the use of NTBS as a means of dissecting the causal architecture of cognitive systems of the human brain.

  1. A cognitive map model based on spatial and goal-oriented mental exploration in rodents.

    Science.gov (United States)

    Zhu, Qing; Wang, Rubin; Wang, Ziyin

    2013-11-01

    The rodent hippocampus has been used to represent the spatial environment as a cognitive map. Classical theories suggest that the cognitive map is a consequence of assignment of different spatial regions to variant cell populations in the framework of rate coding. The current study constructs a novel computational neural model of the cognitive map based on firing rate coding, as widely appears in associative memory, thus providing an explanation for formation and function of the two types of cognitive maps: the spatial vector map, responsible for self localization and simultaneous updating of detailed information; and the goal-oriented vector map, important in route finding. A proposed intermediate between these two map types was constructed by combining the spatial vector and goal-orientation maps to form an effective and efficient path finding mechanism. Application of such novel cognitive map based path finding methods to a mental exploration model was explored. With adaptation as a driving force, the basic knowledge of the location relationships in the spatial cognitive map was reformed and sent to the goal-oriented cognitive map, thus solving a series of new path problems through mental exploration. This method allows for rapid identification of suitable paths under variant conditions, thus providing a simpler and safer resource for path finding. Additionally, this method also provides an improved basis for potential robotic path finding applications.

  2. The multi-component model of working memory: explorations in experimental cognitive psychology.

    Science.gov (United States)

    Repovs, G; Baddeley, A

    2006-04-28

    There are a number of ways one can hope to describe and explain cognitive abilities, each of them contributing a unique and valuable perspective. Cognitive psychology tries to develop and test functional accounts of cognitive systems that explain the capacities and properties of cognitive abilities as revealed by empirical data gathered by a range of behavioral experimental paradigms. Much of the research in the cognitive psychology of working memory has been strongly influenced by the multi-component model of working memory [Baddeley AD, Hitch GJ (1974) Working memory. In: Recent advances in learning and motivation, Vol. 8 (Bower GA, ed), pp 47-90. New York: Academic Press; Baddeley AD (1986) Working memory. Oxford, UK: Clarendon Press; Baddeley A. Working memory: Thought and action. Oxford: Oxford University Press, in press]. By expanding the notion of a passive short-term memory to an active system that provides the basis for complex cognitive abilities, the model has opened up numerous questions and new lines of research. In this paper we present the current revision of the multi-component model that encompasses a central executive, two unimodal storage systems: a phonological loop and a visuospatial sketchpad, and a further component, a multimodal store capable of integrating information into unitary episodic representations, termed episodic buffer. We review recent empirical data within experimental cognitive psychology that has shaped the development of the multicomponent model and the understanding of the capacities and properties of working memory. Research based largely on dual-task experimental designs and on neuropsychological evidence has yielded valuable information about the fractionation of working memory into independent stores and processes, the nature of representations in individual stores, the mechanisms of their maintenance and manipulation, the way the components of working memory relate to each other, and the role they play in other

  3. Contatc Analysis on Thread Connections of 32.8MN PRESS Columns

    Directory of Open Access Journals (Sweden)

    Zhicheng Huang

    2013-07-01

    Full Text Available Automatic hydraulic press is widely used for pressing ceramic wall and floor tiles, the four columns of its frame withstand the all work force when it works, so the columns are the key compartments of the frame, and its work performance has an important impact on the structural performance of the entire automatic hydraulic press. Took the column thread connection of 32.8MN automatic hydraulic press as research object, established axisymmetric finite element model and carried on contact finite element analysis for it by using the large commercial finite element software ANSYS to gain the stress distribution of the column’s thread connection. The results and discussion can provide reference for designing automatic hydraulic press columns.

  4. Cognitive Support using BDI Agent and Adaptive User Modeling

    DEFF Research Database (Denmark)

    Hossain, Shabbir

    2012-01-01

    -known framework to measure the individual health status and functioning level. The third goal is to develop an approach for supporting for users with irrational behaviour due to cognitive impairment. To deal with this challenge, a Belief, Desire and Intention (BDI) agent based approach is proposed due to its...... conducted using the developed system shows potentials in terms of providing freedom of mobility for the user with cognitive impairment.......The need of constant support and care for the elderly people with special needs is gradually increasing. It is becoming the primary challenge for most of the western countries and research society to innovate new eective approaches and develop novel technologies to address the demographics...

  5. Modeling cognition and disease using human glial chimeric mice

    DEFF Research Database (Denmark)

    Goldman, Steven A.; Nedergaard, Maiken; Windrem, Martha S.

    2015-01-01

    that transplanted hGPCs not only engraft and expand within murine hosts, but dynamically outcompete the resident progenitors so as to ultimately dominate the host brain. The engrafted human progenitor cells proceed to generate parenchymal astrocytes, and when faced with a hypomyelinated environment......, oligodendrocytes as well. As a result, the recipient brains may become inexorably humanized with regards to their resident glial populations, yielding human glial chimeric mouse brains. These brains provide us a fundamentally new tool by which to assess the species-specific attributes of glia in modulating human...... cognition and information processing. In addition, the cellular humanization of these brains permits their use in studying glial infectious and inflammatory disorders unique to humans, and the effects of those disorders on the glial contributions to cognition. Perhaps most intriguingly, by pairing our...

  6. Cognitive MAC Protocols for General Primary Network Models

    CERN Document Server

    Mehanna, Omar; Gamal, Hesham El

    2009-01-01

    We consider the design of cognitive Medium Access Control (MAC) protocols enabling a secondary (unlicensed) transmitter-receiver pair to communicate over the idle periods of a set of primary (licensed) channels. More specifically, we propose cognitive MAC protocols optimized for both slotted and un-slotted primary networks. For the slotted structure, the objective is to maximize the secondary throughput while maintaining synchronization between the secondary pair and not causing interference to the primary network. Our investigations differentiate between two sensing scenarios. In the first, the secondary transmitter is capable of sensing all the primary channels, whereas it senses only a subset of the primary channels in the second scenario. In both cases, we propose blind MAC protocols that efficiently learn the statistics of the primary traffic on-line and asymptotically achieve the throughput obtained when prior knowledge of primary traffic statistics is available. For the un-slotted structure, the object...

  7. Epistemology, Situated Cognition, and Mental Models: "Like a Bridge over Troubled Water."

    Science.gov (United States)

    Seel, Norbert M.

    2001-01-01

    Discusses situated cognition as a movement from epistemology, considers the construction of mental models, and describes a study of twelfth graders that investigated the significance of a conceptual model provided at the beginning of the learning process. Results show that mental models are constructed in dependence on the learning situation.…

  8. Application of Three Cognitive Diagnosis Models to ESL Reading and Listening Assessments

    Science.gov (United States)

    Lee, Yong-Won; Sawaki, Yasuyo

    2009-01-01

    The present study investigated the functioning of three psychometric models for cognitive diagnosis--the general diagnostic model, the fusion model, and latent class analysis--when applied to large-scale English as a second language listening and reading comprehension assessments. Data used in this study were scored item responses and incidence…

  9. Testing Cognitive and Emotion-Focused Models of Worry in Black and White Samples.

    Science.gov (United States)

    Kertz, Sarah J; Bakhti, Rinad; Stevens, Kimberly T; Curewitz, Alana

    2015-01-01

    Several models have been proposed to conceptualize worry. Broadly, the models can be classified as cognitive (including the Avoidance Model, the Intolerance of Uncertainty Model, and the Metacognitive Model) and emotion-focused (including Emotion Dysregulation and Acceptance-Based models). Although these models have received strong empirical investigation in primarily non-Hispanic White samples, no known study has examined the applicability to racial and ethnic minority groups. The current study compared the proportion of variance explained by cognitive and emotion-focused models of worry in White and Black samples. Results indicated that cognitive and emotion-focused models significantly predicted worry in both Black and White samples. However, the overall amount of variance in worry explained by the models was less for Black samples. Specifically, controlling for gender, the cognitive models explained 53% of the variance in worry in the White sample compared with 19% in the Black sample. Similarly, the emotion-focused models explained 34% of the variance in worry in the White sample but only 13% in the Black sample. These findings suggest that well-established conceptual frameworks for worry failed to explain the bulk of the variance in worry in Black samples, leaving much unknown. Additional research is needed to identify key variables that may further explain worry in ethnic minority samples.

  10. MSEE: Stochastic Cognitive Linguistic Behavior Models for Semantic Sensing

    Science.gov (United States)

    2013-09-01

    study of human language in terms of neonatal development and evolution in human physiology, sociology, and psychology [1][2]. It offers a different...simple, and universally understood. They are the fundamental gestalts for reasoning. In semantic sensing domain, things would be the most common objects...related places. The cognitive linguistics notion of path organizes places into the structure of an event. A path is a precognitive gestalt that

  11. Cognitive Modeling of Performance Response Capacity Under Time Pressure

    Science.gov (United States)

    2010-12-31

    Dismal extends the GNU Emacs editor using its extension language, Emacs Lisp . This task environment provides the nature of cognition-demanding...process is spawned, and the model’s architecture is loaded within that process. A shell is started in Emacs to invoke OpenMCL that is a Lisp ...to type a letter or to execute a keystroke command, this can be done directly using the extension language of Emacs Lisp . If the command moves the

  12. A cognitive model of second-year organic chemistry students' conceptualizations of mental molecular rotation

    Science.gov (United States)

    Briggs, Michael W.

    The goal of this research was to answer the question, "What is a plausible explanation (model) of the cognitive structure and processes that facilitate mental molecular rotation?". This work used phenomenographic methodology and techniques of interview and think-aloud protocol. Constructivism was the theoretical framework. At the outset of the research, I designed nine tasks to obtain participant articulations of conceptualizations of mental molecular rotations. Articulations from five second-year organic chemistry students attending a Midwestern research university became the research data. Analysis produced four emerging themes along two axes: visualization representation and modeling cognition. These two axes formed a mental space, which was modeled by structure and processes that facilitated mental molecular rotation. A theoretical cognitive model of mental molecular rotation was based on the work of two researchers: Robbie Case and Richard Lesh. Lesh's "mental model" is composed of cognitive elements and operations, which are distributed over heeded local and global cognitive sub-models whereas Case deals with unheeded central conceptual structures. The models and structures interact to produce new knowledge and facilitate the use of existing knowledge. Two predictions of the theory of mental molecular rotation were elaborated. Students without a set of operations in a central conceptual structure will not be able to mentally rotate molecules. This is true even if a set of components, other than "operation", is constructed. The artifacts of mental molecular rotation can be used to determine the state of construction of the central conceptual structure responsible for mental molecular rotation.

  13. Toward affect-inclusive models of cognitive dynamics: Coupling epistemological resources and emotions

    CERN Document Server

    Gupta, Ayush; Elby, Andrew

    2013-01-01

    Many prominent lines of research on student's reasoning and conceptual change within learning sciences and physics education research have not attended to the role of learners' affect or emotions in the dynamics of their conceptual reasoning. This is despite evidence from psychology and cognitive- and neuro- sciences that emotions are deeply integrated with cognition and documented associations in education research between emotions and academic performance. The few studies that have aimed to integrate emotions within models of learners' cognition, have mostly done so at a coarse grain size. In this manuscript, toward the long-term goal of incorporating emotions into fine-grained models of in-themoment cognitive dynamics, we present a case study of Judy, an undergraduate electrical engineering and physics major. We argue that a fine-grained aspect of Judy's affect, her annoyance at a particular kind of homework problem, stabilizes a context-dependent epistemological stance she displays, about an unbridgeable ...

  14. A cognitive-behavioral model of Internet gaming disorder: theoretical underpinnings and clinical implications.

    Science.gov (United States)

    Dong, Guangheng; Potenza, Marc N

    2014-11-01

    Cognitive contributions to the behaviors observed in substance and non-substance addictions have been investigated and characterized. Based on models of drug addictions and the extant literature on Internet gaming disorder (IGD), we propose a cognitive-behavioral model for conceptualizing IGD. The model focuses on three domains and their roles in addictive behaviors. The three domains include motivational drives related to reward-seeking and stress-reduction, behavioral control relating to executive inhibition, and decision-making that involves weighing the pros and cons of engaging in motivated behaviors. Based on this model, we propose how behavioral therapies might target these domains in the treatment of IGD.

  15. Periodic Eclipse Variations in Asynchronous Polar V1432 Aql: Evidence of a Shifting Threading Region

    Science.gov (United States)

    Littlefield, Colin; Mukai, Koji; Mumme, Raymond; Cain, Ryan; Magno, Katrina C.; Corpuz, Taylor; Sandefur, Davis; Boyd, David; Cook, Michael; Ulowetz, Joseph; Martinez, Louis

    2015-01-01

    We report the results of a 28-month photometric campaign studying V1432 Aql, the only known eclipsing, asynchronous polar. Our data show that both the residual eclipse flux and eclipse O-C timings vary strongly as a function of the spin-orbit beat period. Relying upon a new model of the system, we show that cyclical changes in the location of the threading region along the ballistic trajectory of the accretion stream could produce both effects. This model predicts that the threading radius is variable, in contrast to previous studies which have assumed a constant threading radius. Additionally, we identify a very strong photometric maximum which is only visible for half of the beat cycle. The exact cause of this maximum is unclear, but we consider the possibility that it is the optical counterpart of the third accreting polecap proposed by Rana et al. Finally, the rate of change of the white dwarf's spin period is consistent with it being proportional to the difference between the spin and orbital periods, implying that the spin period is approaching the orbital period asymptotically.

  16. Optimization Strategies Oriented to Loop Characteristics in Software Thread Level Speculation Systems

    Institute of Scientific and Technical Information of China (English)

    Li Shen; Fan Xu; Zhi-Ying Wang

    2016-01-01

    Thread level speculation provides not only a simple parallel programming model, but also an effective mech-anism for thread-level parallelism exploitation. The performance of software speculative parallel models is limited by high global overheads caused by different types of loops. These loops usually have different characteristics of dependencies and different requirements of optimization strategies. In this paper, we propose three comprehensive optimization techniques to reduce different factors of global overheads, aiming at requirements from different types of loops. Inter-thread fetching can reduce the high mis-speculation rate of the loops with frequent dependencies and out-of-order committing can reduce the control overhead of the loops with infrequent dependencies, while enhanced dynamic task granularity resizing can reduce the control overhead and optimize the global overhead of the loops with changing characteristics of dependencies. All these three optimization techniques have been implemented in HEUSPEC, a software TLS system. Experimental results indicate that they can satisfy the demands from different groups of benchmarks. The combination of these techniques can improve the performance of all benchmarks and reach a higher average speedup.

  17. Biologically Inspired Visual Model With Preliminary Cognition and Active Attention Adjustment.

    Science.gov (United States)

    Qiao, Hong; Xi, Xuanyang; Li, Yinlin; Wu, Wei; Li, Fengfu

    2015-11-01

    Recently, many computational models have been proposed to simulate visual cognition process. For example, the hierarchical Max-Pooling (HMAX) model was proposed according to the hierarchical and bottom-up structure of V1 to V4 in the ventral pathway of primate visual cortex, which could achieve position- and scale-tolerant recognition. In our previous work, we have introduced memory and association into the HMAX model to simulate visual cognition process. In this paper, we improve our theoretical framework by mimicking a more elaborate structure and function of the primate visual cortex. We will mainly focus on the new formation of memory and association in visual processing under different circumstances as well as preliminary cognition and active adjustment in the inferior temporal cortex, which are absent in the HMAX model. The main contributions of this paper are: 1) in the memory and association part, we apply deep convolutional neural networks to extract various episodic features of the objects since people use different features for object recognition. Moreover, to achieve a fast and robust recognition in the retrieval and association process, different types of features are stored in separated clusters and the feature binding of the same object is stimulated in a loop discharge manner and 2) in the preliminary cognition and active adjustment part, we introduce preliminary cognition to classify different types of objects since distinct neural circuits in a human brain are used for identification of various types of objects. Furthermore, active cognition adjustment of occlusion and orientation is implemented to the model to mimic the top-down effect in human cognition process. Finally, our model is evaluated on two face databases CAS-PEAL-R1 and AR. The results demonstrate that our model exhibits its efficiency on visual recognition process with much lower memory storage requirement and a better performance compared with the traditional purely computational

  18. Network-oriented modeling addressing complexity of cognitive, affective and social interactions

    CERN Document Server

    Treur, Jan

    2016-01-01

    This book presents a new approach that can be applied to complex, integrated individual and social human processes. It provides an alternative means of addressing complexity, better suited for its purpose than and effectively complementing traditional strategies involving isolation and separation assumptions. Network-oriented modeling allows high-level cognitive, affective and social models in the form of (cyclic) graphs to be constructed, which can be automatically transformed into executable simulation models. The modeling format used makes it easy to take into account theories and findings about complex cognitive and social processes, which often involve dynamics based on interrelating cycles. Accordingly, it makes it possible to address complex phenomena such as the integration of emotions within cognitive processes of all kinds, of internal simulations of the mental processes of others, and of social phenomena such as shared understandings and collective actions. A variety of sample models – including ...

  19. Understanding and predicting online purchase intention: Development of a model for cognitive-affective shopper responses

    OpenAIRE

    Lu, KJ

    2016-01-01

    This paper aims to develop a model for online purchase intention in a B2C environment, integrating cognitive and affective responses based on the theory of reasoned action. Seven hypotheses were developedand tested on a dataset of 532 observations collected via a questionnaire survey. The results of this study indicate that both cognitive and affective judgements are important for online transactions.A contribution of this study is that it extends our understanding of how online purchase inte...

  20. Modeling the effects of noninvasive transcranial brain stimulation at the biophysical, network, and cognitive Level

    DEFF Research Database (Denmark)

    Hartwigsen, Gesa; Bergmann, Til Ole; Herz, Damian Marc

    2015-01-01

    Noninvasive transcranial brain stimulation (NTBS) is widely used to elucidate the contribution of different brain regions to various cognitive functions. Here we present three modeling approaches that are informed by functional or structural brain mapping or behavior profiling and discuss how...... predictions regarding the impact of interindividual variations in cortical anatomy on the injected electric fields or the influence of the orientation of current flow on the physiological stimulation effects. (ii) Functional brain mapping of the spatiotemporal neural dynamics during cognitive tasks can...

  1. Developing a Creative-Cognitive Model of Entrepreneurial Alertness to Business Opportunities

    OpenAIRE

    Vesa Puhakka

    2011-01-01

    A creative-cognitive perspective is used in this study to explore alertness to business opportunities in order to develop a model of business opportunity recognition. It is assumed that the elements constituting this opportunity creation are entrepreneur¡¯s creative cognitive process, internal creative qualities, environmental conditions supporting or hindering creativity and interaction of these elements, and that they have a significant impact on the innovativeness of the business opportuni...

  2. Assessments of cognitive abilities in a mouse model of Parkinson's disease with a touch screen test.

    Science.gov (United States)

    Kwak, Chuljung; Lim, Chae-Seok; Kaang, Bong-Kiun

    2016-03-15

    Patients with Parkinson's disease (PD) experience both motor output deficits and cognitive disabilities. Various PD rodent models have been developed to investigate the genetic and brain circuit-related causes of PD and have contributed to the basic and clinical research and to therapeutic strategies for this disease. Most studies using PD rodent models have focused on the motor output deficits, rather than cognitive disabilities due to the lack of appropriate testing tools that do not require significant motor abilities. In this study, we assessed the cognitive disabilities of PD model mice using a touch screen test that required only little motor ability. We found that the PD model mice, which had motor deficits caused by unilateral striatal dopaminergic degeneration, successfully underwent operant conditioning with a touch screen test. Additionally, we found that the PD model mice demonstrated impaired location discrimination, but intact attention and reversal learning in the cognitive tests. Therefore, the touch screen test is useful for assessing hidden cognitive disabilities in disease model animals with decreased motor function.

  3. l-Carnitine improves cognitive and renal functions in a rat model of chronic kidney disease.

    Science.gov (United States)

    Abu Ahmad, Nur; Armaly, Zaher; Berman, Sylvia; Jabour, Adel; Aga-Mizrachi, Shlomit; Mosenego-Ornan, Efrat; Avital, Avi

    2016-10-01

    Over the past decade, the prevalence of chronic kidney disease (CKD) has reached epidemic proportions. The search for novel pharmacological treatment for CKD has become an area of intensive clinical research. l-Carnitine, considered as the "gatekeeper" responsible for admitting long chain fatty acids into cell mitochondria. l-Carnitine synthesis and turnover are regulated mainly by the kidney and its levels inversely correlate with serum creatinine of normal subjects and CKD patients. Previous studies showed that l-carnitine administration to elderly people is improving and preserving cognitive function. As yet, there are no clinical intervention studies that investigated the effect of l-carnitine administration on cognitive impairment evidenced in CKD patients. Thus, we aimed to investigate the effects of l-carnitine treatment on renal function and on the cognitive performance in a rat model of progressive CKD. To assess the role of l-carnitine on CKD condition, we estimated the renal function and cognitive abilities in a CKD rat model. We found that all CKD animals exhibited renal function deterioration, as indicated by elevated serum creatinine, BUN, and ample histopathological abnormalities. l-Carnitine treatment of CKD rats significantly reduced serum creatinine and BUN, attenuated renal hypertrophy and decreased renal tissue damage. In addition, in the two way shuttle avoidance learning, CKD animals showed cognitive impairment which recovered by the administration of l-carnitine. We conclude that in a rat model of CKD, l-carnitine administration significantly improved cognitive and renal functions.

  4. Dogs with cognitive dysfunction as a spontaneous model for early Alzheimer's Disease

    DEFF Research Database (Denmark)

    Schütt, Trine; Helboe, Lone; Pedersen, Lars Østergaard

    2016-01-01

    Aged companion dogs with canine cognitive dysfunction (CCD) spontaneously develop varying degrees of progressive cognitive decline and particular neuropathological features correspondent to the changes associated with Alzheimer's disease (AD) in humans. The aim of the present study was to charact......Aged companion dogs with canine cognitive dysfunction (CCD) spontaneously develop varying degrees of progressive cognitive decline and particular neuropathological features correspondent to the changes associated with Alzheimer's disease (AD) in humans. The aim of the present study...... was to characterize certain aspects of neuropathology and inflammatory markers related to aging and CCD in dogs in comparison with human AD. Fifteen brains from aged dogs with normal cognitive function, mild cognitive impairment, or CCD were investigated and compared with two control brains from young dogs and brain...... support the senescent dog with spontaneous cognitive dysfunction as a valuable non-transgenic model for further investigations of the molecular events involved in the neurodegenerative processes associated with aging and early stage AD, especially the Aβ-related pathology....

  5. Anatomy and computational modeling of networks underlying cognitive-emotional interaction

    Directory of Open Access Journals (Sweden)

    Yohan Joshua John

    2013-04-01

    Full Text Available The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize ``cognitive control'' in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

  6. Anatomy and computational modeling of networks underlying cognitive-emotional interaction.

    Science.gov (United States)

    John, Yohan J; Bullock, Daniel; Zikopoulos, Basilis; Barbas, Helen

    2013-01-01

    The classical dichotomy between cognition and emotion equated the first with rationality or logic and the second with irrational behaviors. The idea that cognition and emotion are separable, antagonistic forces competing for dominance of mind has been hard to displace despite abundant evidence to the contrary. For instance, it is now known that a pathological absence of emotion leads to profound impairment of decision making. Behavioral observations of this kind are corroborated at the mechanistic level: neuroanatomical studies reveal that brain areas typically described as underlying either cognitive or emotional processes are linked in ways that imply complex interactions that do not resemble a simple mutual antagonism. Instead, physiological studies and network simulations suggest that top-down signals from prefrontal cortex realize "cognitive control" in part by either suppressing or promoting emotional responses controlled by the amygdala, in a way that facilitates adaptation to changing task demands. Behavioral, anatomical, and physiological data suggest that emotion and cognition are equal partners in enabling a continuum or matrix of flexible behaviors that are subserved by multiple brain regions acting in concert. Here we focus on neuroanatomical data that highlight circuitry that structures cognitive-emotional interactions by directly or indirectly linking prefrontal areas with the amygdala. We also present an initial computational circuit model, based on anatomical, physiological, and behavioral data to explicitly frame the learning and performance mechanisms by which cognition and emotion interact to achieve flexible behavior.

  7. CNT coated thread micro-electro-mechanical system for finger proprioception sensing

    Science.gov (United States)

    Shafi, A. A.; Wicaksono, D. H. B.

    2017-04-01

    In this paper, we aim to fabricate cotton thread based sensor for proprioceptive application. Cotton threads are utilized as the structural component of flexible sensors. The thread is coated with multi-walled carbon nanotube (MWCNT) dispersion by using facile conventional dipping-drying method. The electrical characterization of the coated thread found that the resistance per meter of the coated thread decreased with increasing the number of dipping. The CNT coated thread sensor works based on piezoresistive theory in which the resistance of the coated thread changes when force is applied. This thread sensor is sewed on glove at the index finger between middle and proximal phalanx parts and the resistance change is measured upon grasping mechanism. The thread based microelectromechanical system (MEMS) enables the flexible sensor to easily fit perfectly on the finger joint and gives reliable response as proprioceptive sensing.

  8. High Performance Computing for Agent-Based Cognitive Modeling

    Science.gov (United States)

    2011-02-25

    2.2.2.2 EX2 and EX3 Agents - ACT-R A simple agent was developed by Jaehyon Paik using the LISP -based ACT-R cognitive framework. Unlike the EX1...current user, and connecting the new one to the same account. 5 Both of these issues were overcome by generating pieces of the agent LISP code during...on a single local machine. The Fenrir VM was used to host the environment. Versions of MPI (MPICH2), and LISP (Clozure LISP ) that are available on

  9. MENS, an Info-Computational Model for (Neuro-cognitive Systems Capable of Creativity

    Directory of Open Access Journals (Sweden)

    Andrée C. Ehresmann

    2012-09-01

    Full Text Available MENS is a bio-inspired model for higher level cognitive systems; it is an application of the Memory Evolutive Systems developed with Vanbremeersch to model complex multi-scale, multi-agent self-organized systems, such as biological or social systems. Its development resorts to an info-computationalism: first we characterize the properties of the human brain/mind at the origin of higher order cognitive processes up to consciousness and creativity, then we ‘abstract’ them in a MENS mathematical model for natural or artificial cognitive systems. The model, based on a ‘dynamic’ Category Theory incorporating Time, emphasizes the computability problems which are raised.

  10. Efficient Thread Mapping for Heterogeneous Multicore IoT Systems

    Directory of Open Access Journals (Sweden)

    Thomas Mezmur Birhanu

    2017-01-01

    Full Text Available This paper proposes a thread scheduling mechanism primed for heterogeneously configured multicore systems. Our approach considers CPU utilization for mapping running threads with the appropriate core that can potentially deliver the actual needed capacity. The paper also introduces a mapping algorithm that is able to map threads to cores in an O(N log M time complexity, where N is the number of cores and M is the number of types of cores. In addition to that we also introduced a method of profiling heterogeneous architectures based on the discrepancy between the performances of individual cores. Our heterogeneity aware scheduler was able to speed up processing by 52.62% and save power by 2.22% as compared to the CFS scheduler that is a default in Linux systems.

  11. Hair-thread tourniquet syndrome in a preterm baby.

    Science.gov (United States)

    Baştuğ, Osman; Korkmaz, Levent; Korkut, Sabriye; Halis, Hülya; Kurtoğlu, Selim

    2015-12-01

    Hair-thread tourniquet syndrome is a rare disorder characterized by the encircling of an appendage by a hair or thread. It usually occurs in children under the age of one year. The tourniquet syndrome may occur in different parts of the body, particularly in toes, fingers, penis, clitoris, labia, neck and uvula. It is an emergency condition that induces progressive edema, ischaemia and tissue necrosis and can lead to autoamputation of digits or other strangulated structures. Emergency treatment is careful removal of the constricting fiber. We report a preterm newborn with hair-thread tourniquet syndrome affecting multiple toes born at the 28th gestational week with the aim of preventing potential complications by increasesing awareness of the condition.

  12. Weaving of organic threads into a crystalline covalent organic framework.

    Science.gov (United States)

    Liu, Yuzhong; Ma, Yanhang; Zhao, Yingbo; Sun, Xixi; Gándara, Felipe; Furukawa, Hiroyasu; Liu, Zheng; Zhu, Hanyu; Zhu, Chenhui; Suenaga, Kazutomo; Oleynikov, Peter; Alshammari, Ahmad S; Zhang, Xiang; Terasaki, Osamu; Yaghi, Omar M

    2016-01-22

    A three-dimensional covalent organic framework (COF-505) constructed from helical organic threads, designed to be mutually weaving at regular intervals, has been synthesized by imine condensation reactions of aldehyde functionalized copper(I)-bisphenanthroline tetrafluoroborate, Cu(PDB)2(BF4), and benzidine (BZ). The copper centers are topologically independent of the weaving within the COF structure and serve as templates for bringing the threads into a woven pattern rather than the more commonly observed parallel arrangement. The copper(I) ions can be reversibly removed and added without loss of the COF structure, for which a tenfold increase in elasticity accompanies its demetalation. The threads in COF-505 have many degrees of freedom for enormous deviations to take place between them, throughout the material, without undoing the weaving of the overall structure.

  13. A VAM thread for line pipe J-LAY operations

    Energy Technology Data Exchange (ETDEWEB)

    Peter, Jean-Pierre [Vallourec Mannesmann Oil and Gas, Boulogne (France)

    2000-07-01

    Following increasing demand for line pipe in deep sea water, Bouygues Off-Shore and Vallourec Mannesmann Oil and Gas France have decided to develop and promote an innovative VAM threaded connection, to be implemented according to J-Lay method. The paper is addressing first the application that we decided to cover. The designed solution and its specificities compared to standard premium threads for vertical completions is described in detail. The qualification process of the product to confirm its leak tightness performance envelope and to validate its operational performances is presented. Finally, the paper is providing the running and pipe laying procedures of such concept and is giving inputs to a general trade-off between a conventional welded solution and such 'threaded line pipe' option. (author)

  14. Threading on ADI Cast Iron, Developing Tools and Conditions

    Science.gov (United States)

    Elósegui, I.; de Lacalle, L. N. López

    2011-01-01

    The present work is focussed on the improvement of the design and performance of the taps used for making threaded holes in ADI (Austempered Ductile Iron). It is divided in two steps: a) The development of a method valid to compare the taps wear without reaching the end of their life, measuring the required torque to make one threaded hole, after having made previously a significant number of threaded holes. The tap wear causes some teeth geometrical changes, that supposes an increase in the required torque and axial force. b) The taps wear comparison method is open to apply on different PVD coated taps, AlTiN, AlCrSiN, AlTiSiN, , and to different geometries.

  15. A cognitive psychometric model for the psychodiagnostic assessment of memory-related deficits.

    Science.gov (United States)

    Alexander, Gregory E; Satalich, Timothy A; Shankle, W Rodman; Batchelder, William H

    2016-03-01

    Clinical tests used for psychodiagnostic purposes, such as the well-known Alzheimer's Disease Assessment Scale: Cognitive subscale (ADAS-Cog), include a free-recall task. The free-recall task taps into latent cognitive processes associated with learning and memory components of human cognition, any of which might be impaired with the progression of Alzheimer's disease (AD). A Hidden Markov model of free recall is developed to measure latent cognitive processes used during the free-recall task. In return, these cognitive measurements give us insight into the degree to which normal cognitive functions are differentially impaired by medical conditions, such as AD and related disorders. The model is used to analyze the free-recall data obtained from healthy elderly participants, participants diagnosed as having mild cognitive impairment, and participants diagnosed with early AD. The model is specified hierarchically to handle item differences because of the serial position curve in free recall, as well as within-group individual differences in participants' recall abilities. Bayesian hierarchical inference is used to estimate the model. The model analysis suggests that the impaired patients have the following: (1) long-term memory encoding deficits, (2) short-term memory (STM) retrieval deficits for all but very short time intervals, (3) poorer transfer into long-term memory for items successfully retrieved from STM, and (4) poorer retention of items encoded into long-term memory after longer delays. Yet, impaired patients appear to have no deficit in immediate recall of encoded words in long-term memory or for very short time intervals in STM.

  16. Agent-based modeling as a research method for exploring joint decision making in organizations – a distributed cognition perspective

    DEFF Research Database (Denmark)

    Thomsen, Svend Erik

    2017-01-01

    This paper proposes an agent-based model to explore aspects of decision making in organizations from a distributed cognition perspective. Within distributed cognition research cognition is conceptualized as a process that takes place - not only within individuals’ minds but also between them...... decision making and distributed cognition......., as they interact with each other. This means that the interactions between individuals impact both the outcome of the decision process and the individuals’ cognition, which in turn will impact their subsequent decisions. The paper outlines how this dynamic and complex task can be modeled taking into account...

  17. Increasing the cyclic strength of threaded joints through the unloading of cracked sections

    Directory of Open Access Journals (Sweden)

    Krenevičius A.

    2012-01-01

    Full Text Available The cyclic strength of the axially loaded threaded joints is considered and the procedural method to increase their lifetime through the unloading of cracked sections is presented. The method operates by varying the mutual positions of the stud and the nut. It was shown how to exploit resources of the threaded joint after opening of the crack without reduction of the safety. The developed mathematical model allows control the accumulation of the fatigue damage as well as the crack growth in the roots of the stud thread. Increase of the cyclic lifetime is theoretically evaluated by the ratio of the numbers of loading cycles required to initiate cracks in the roots of unengaged and the most dangerous engaged turns of the stud. Performance of the elaborated technique is demonstrated by considering the crack growth in depth of the nut. The relative safety of the unloaded cross-sections containing cracks is studied. Comparison of the presented developments with standard safety requirements is presented.

  18. A cognitive-inspired model for self-organizing networks

    CERN Document Server

    Borkmann, Daniel; Massaro, Emanuele; Rudolph, Stefan

    2012-01-01

    In this work, we propose a computational scheme inspired by the workings of human cognition in order to embed some fundamental aspects of the human cognitive system such as the minimization of the computational resources, and the evolution of a dynamic knowledge network over time into computer networks. Such algorithm is capable of generating suitable strategies to explore networks like the Internet, which are too large and too dynamic to be ever perfectly known. The algorithm equips each node with a local information about the possible hubs which are present in its environment. Such information can be used by a node to change its connections whenever its fitness is not satisfying some given requirements. Finally, we compare our algorithm with a randomized approach within an ecological scenario for the ICT domain, where a network of nodes carries a certain set of objects, and each node retrieves a subset at a certain time, constrained with limited resources in terms of energy and bandwidth. We show that a cog...

  19. The role of regulation in the origin and synthetic modelling of minimal cognition.

    Science.gov (United States)

    Bich, Leonardo; Moreno, Alvaro

    2016-10-01

    In this paper we address the question of minimal cognition by investigating the origin of some crucial cognitive properties from the very basic organisation of biological systems. More specifically, we propose a theoretical model of how a system can distinguish between specific features of its interaction with the environment, which is a fundamental requirement for the emergence of minimal forms of cognition. We argue that the appearance of this capacity is grounded in the molecular domain, and originates from basic mechanisms of biological regulation. In doing so, our aim is to provide a theoretical account that can also work as a possible conceptual bridge between Synthetic Biology and Artificial Intelligence. In fact, we argue, Synthetic Biology can contribute to the study of minimal cognition (and therefore to a minimal AI), by providing a privileged approach to the study of these mechanisms by means of artificial systems. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  20. Cognitive improvement by activation of alpha7 nicotinic acetylcholine receptors: from animal models to human pathophysiology

    DEFF Research Database (Denmark)

    Thomsen, Morten S; Hansen, Henrik H; Timmerman, Daniel B

    2010-01-01

    Agonists and positive allosteric modulators of the alpha(7) nicotinic acetylcholine receptor (nAChR) are currently being developed for the treatment of cognitive disturbances in patients with schizophrenia or Alzheimer's disease. This review describes the neurobiological properties of the alpha n......AChR and the cognitive effects of alpha(7) nAChR activation, focusing on the translational aspects in the development of these drugs. The functional properties and anatomical localization of the alpha(7) nAChR makes it well suited to modulate cognitive function. Accordingly, systemic administration of alpha(7) n......AChR agonists improves learning, memory, and attentional function in variety of animal models, and pro-cognitive effects of alpha(7) nAChR agonists have recently been demonstrated in patients with schizophrenia or Alzheimer's disease. The alpha(7) nAChR desensitizes rapidly in vitro, and this has been a major...

  1. Threaded insert for compact cryogenic-capable pressure vessels

    Energy Technology Data Exchange (ETDEWEB)

    Espinosa-Loza, Francisco; Ross, Timothy O.; Switzer, Vernon A.; Aceves, Salvador M.; Killingsworth, Nicholas J.; Ledesma-Orozco, Elias

    2015-06-16

    An insert for a cryogenic capable pressure vessel for storage of hydrogen or other cryogenic gases at high pressure. The insert provides the interface between a tank and internal and external components of the tank system. The insert can be used with tanks with any or all combinations of cryogenic, high pressure, and highly diffusive fluids. The insert can be threaded into the neck of a tank with an inner liner. The threads withstand the majority of the stress when the fluid inside the tank that is under pressure.

  2. Design and synthesis of threading intercalators to target DNA.

    Science.gov (United States)

    Howell, Lesley A; Gulam, Rosul; Mueller, Anja; O'Connell, Maria A; Searcey, Mark

    2010-12-01

    Threading intercalators are high affinity DNA binding agents that bind by inserting a chromophore into the duplex and locating one group in each groove. The first threading intercalators that can be conjugated to acids, sulfonic acids and peptides to target them to duplex DNA are described, based upon the well studied acridine-3- or 4-carboxamides. Cellular uptake of the parent acridine is rapid and it can be visualized in the nucleus of cells. Both the parent compounds and their conjugates maintain antitumor activity.

  3. Threaded insert for compact cryogenic-capable pressure vessels

    Science.gov (United States)

    Espinosa-Loza, Francisco; Ross, Timothy O.; Switzer, Vernon A.; Aceves, Salvador M.; Killingsworth, Nicholas J.; Ledesma-Orozco, Elias

    2015-06-16

    An insert for a cryogenic capable pressure vessel for storage of hydrogen or other cryogenic gases at high pressure. The insert provides the interface between a tank and internal and external components of the tank system. The insert can be used with tanks with any or all combinations of cryogenic, high pressure, and highly diffusive fluids. The insert can be threaded into the neck of a tank with an inner liner. The threads withstand the majority of the stress when the fluid inside the tank that is under pressure.

  4. Evaluation of the integrated cognitive model of depression and its specificity in a migrant population.

    Science.gov (United States)

    Oei, Tian P S; Kwon, Seok-Man

    2007-01-01

    This study empirically tested the specificity of the integrated cognitive model (ICM) of depression, which postulates that negative life events interact with dysfunctional attitudes to increase the frequency and severity of automatic thoughts, subsequently affecting depressive symptoms. We also examined the three competing models: the linear mediation model, the alternative etiologies model, and the symptom model. We anticipated that we might examine these models more appropriately using data from a population at an increased risk of developing depressive symptoms. As such, two-wave panel data were obtained from a group of 107 Korean migrants who had been in Australia less than 1 year. Structural equation modeling revealed that the ICM provided an adequate and much better fit than the three competing models. The ICM was also found to support the cognitive specificity theory of depression and anxiety. These findings suggest that dysfunctional attitudes can be a common cognitive moderator of depression and anxiety, whereas automatic thoughts and anxious self-statements can be specific cognitive mediators of anxiety and depression, respectively.

  5. Cognitive Models: The Missing Link to Learning Fraction Multiplication and Division

    Science.gov (United States)

    de Castro, Belinda V.

    2008-01-01

    This quasi-experimental study aims to streamline cognitive models on fraction multiplication and division that contain the most worthwhile features of other existing models. Its exploratory nature and its approach to proof elicitation can be used to help establish its effectiveness in building students' understanding of fractions as compared to…

  6. When, What, and How Much to Reward in Reinforcement Learning-Based Models of Cognition

    NARCIS (Netherlands)

    Janssen, Christian P.; Gray, Wayne D.

    Reinforcement learning approaches to cognitive modeling represent task acquisition as learning to choose the sequence of steps that accomplishes the task while maximizing a reward. However, an apparently unrecognized problem for modelers is choosing when, what, and how much to reward; that is, when

  7. States-of-Mind Model: Cognitive Balance in the Treatment of Agoraphobia.

    Science.gov (United States)

    Schwartz, Robert M.; Michelson, Larry

    1987-01-01

    Used states-of-mind model to track therapeutic changes in cognitive balance of 39 agoraphobics. Descriptive and statistical analyses from an outcome study of graduated exposure, relaxation training, and paradoxical intention supported the model. Agoraphobics evinced negative dialogue at pretreatment, positive dialogue at mid and posttreatment, and…

  8. Cognitive Models of Risky Choice: Parameter Stability and Predictive Accuracy of Prospect Theory

    Science.gov (United States)

    Glockner, Andreas; Pachur, Thorsten

    2012-01-01

    In the behavioral sciences, a popular approach to describe and predict behavior is cognitive modeling with adjustable parameters (i.e., which can be fitted to data). Modeling with adjustable parameters allows, among other things, measuring differences between people. At the same time, parameter estimation also bears the risk of overfitting. Are…

  9. Cognitive modelling of pilot errors and error recovery in flight management tasks

    NARCIS (Netherlands)

    Lüdtke, A.; Osterloh, J.P.; Mioch, T.; Rister, F.; Looije, R.

    2009-01-01

    This paper presents a cognitive modelling approach to predict pilot errors and error recovery during the interaction with aircraft cockpit systems. The model allows execution of flight procedures in a virtual simulation environment and production of simulation traces. We present traces for the inter

  10. Visual representations of the idealized cognitive model of anger in the Asterix album 'La Zizanie'

    NARCIS (Netherlands)

    C. Forceville

    2005-01-01

    The conceptual metaphor program launched by Lakoff and Johnson [Metaphors We Live By, Chicago, University of Chicago Press, 1980] attempts to chart and describe the Idealized Cognitive Models (ICMs) that govern human thinking. The manifestations of these models studied hitherto, however, are almost

  11. The transmission of early Christian thought : Toward a cognitive psychological model

    NARCIS (Netherlands)

    Czachesz, Istvan

    2007-01-01

    This article uses current developments in cognitive science to explore the emergence of early Christian religion. In particular, it considers Sperber's epidemiology model, Rubin's serial recall model, ritual form theory and Boyer's theory of religious concepts for understanding the transmission of

  12. Toward an Integrative Model of Suicide Attempt: A Cognitive Psychological Approach.

    Science.gov (United States)

    Dieserud, Gudrun; Roysamb, Espen; Ekeberg, Oivind; Kraft, Pal

    2001-01-01

    Applying a cognitive approach, this study expanded previous research on stress vulnerability models of depression and problem solving deficits, as it relates to suicide attempt. Results indicated a two path model of suicide attempt. The importance of addressing both depression/hopelessness, and problem solving deficits when working with suicide…

  13. When, What, and How Much to Reward in Reinforcement Learning-Based Models of Cognition

    NARCIS (Netherlands)

    Janssen, Christian P.; Gray, Wayne D.

    2012-01-01

    Reinforcement learning approaches to cognitive modeling represent task acquisition as learning to choose the sequence of steps that accomplishes the task while maximizing a reward. However, an apparently unrecognized problem for modelers is choosing when, what, and how much to reward; that is, when

  14. Predicting the Job and Life Satisfaction of Italian Teachers: Test of a Social Cognitive Model

    Science.gov (United States)

    Lent, Robert W.; Nota, Laura; Soresi, Salvatore; Ginevra, Maria C.; Duffy, Ryan D.; Brown, Steven D.

    2011-01-01

    This study tested a social cognitive model of work and life satisfaction (Lent & Brown, 2006, 2008) in a sample of 235 Italian school teachers. The model offered good overall fit to the data, though not all individual path coefficients were significant. Three of five predictors (favorable work conditions, efficacy-relevant supports, and…

  15. Steps to a formal analysis of the cognitive-energetic model of stress and human performance

    NARCIS (Netherlands)

    P.C.M. Molenaar; M.W. van der Molen

    1986-01-01

    A. F. Sanders's cognitive-energetic model of stress and human performance attempts to bridge linear stage and capacity models of information processing. It is argued that the identifiability of effects of variations of some subset of component processes can only be properly evaluated through an appr

  16. When, What, and How Much to Reward in Reinforcement Learning-Based Models of Cognition

    Science.gov (United States)

    Janssen, Christian P.; Gray, Wayne D.

    2012-01-01

    Reinforcement learning approaches to cognitive modeling represent task acquisition as learning to choose the sequence of steps that accomplishes the task while maximizing a reward. However, an apparently unrecognized problem for modelers is choosing when, what, and how much to reward; that is, when (the moment: end of trial, subtask, or some other…

  17. Performance of Cognitive Models of Web-Navigation on Real Websites

    NARCIS (Netherlands)

    Karanam, S.; van Oostendorp, H.; Fu, Wai Tat

    2016-01-01

    Computational cognitive models of web-navigation developed so far have largely been tested only on mock-up websites. In this paper, for the first time, we compare and contrast the performance of two models, CoLiDeS and CoLiDeS + , on two real websites from the domains of technology and health, under

  18. An Intelligent Tutoring System for Learning Chinese with a Cognitive Model of the Learner

    Science.gov (United States)

    Kosek, Michal; Lison, Pierre

    2014-01-01

    We present an intelligent tutoring system that lets students of Chinese learn words and grammatical constructions. It relies on a Bayesian, linguistically motivated cognitive model that represents the learner's knowledge. This model is dynamically updated given observations about the learner's behaviour in the exercises, and employed at runtime to…

  19. The research of constructing dynamic cognition model based on brain network

    Directory of Open Access Journals (Sweden)

    Fang Chunying

    2017-03-01

    Full Text Available Estimating the functional interactions and connections between brain regions to corresponding process in cognitive, behavioral and psychiatric domains is a central pursuit for understanding the human connectome. Few studies have examined the effects of dynamic evolution on cognitive processing and brain activation using brain network model in scalp electroencephalography (EEG data. Aim of this study was to investigate the brain functional connectivity and construct dynamic programing model from EEG data and to evaluate a possible correlation between topological characteristics of the brain connectivity and cognitive evolution processing. Here, functional connectivity between brain regions is defined as the statistical dependence between EEG signals in different brain areas and is typically determined by calculating the relationship between regional time series using wavelet coherence. We present an accelerated dynamic programing algorithm to construct dynamic cognitive model that we found that spatially distributed regions coherence connection difference, the topologic characteristics with which they can transfer information, producing temporary network states. Our findings suggest that brain dynamics give rise to variations in complex network properties over time after variation audio stimulation, dynamic programing model gives the dynamic evolution processing at different time and frequency. In this paper, by applying a new construct approach to understand whole brain network dynamics, firstly, brain network is constructed by wavelet coherence, secondly, different time active brain regions are selected by network topological characteristics and minimum spanning tree. Finally, dynamic evolution model is constructed to understand cognitive process by dynamic programing algorithm, this model is applied to the auditory experiment, results showed that, quantitatively, more correlation was observed after variation audio stimulation, the EEG function

  20. A scientific cognitive behavioral model of tinnitus: novel conceptualizations of tinnitus distress

    Directory of Open Access Journals (Sweden)

    Laurence eMcKenna

    2014-10-01

    Full Text Available The importance of psychological factors in tinnitus distress has been formally recognized for almost three decades. The psychological understanding of why tinnitus can be a distressing condition posits that it becomes problematic when it acquires an emotive significance through cognitive processes. Principle therapeutic efforts are directed at reducing or removing the cognitive (and behavioral obstacles to habituation. Here, the evidence relevant to a new psychological model of tinnitus is critically reviewed. The model posits that patients’ interpretations of tinnitus and the changes in behavior that result are given a central role in creating and maintaining distress. The importance of selective attention and the possibility that this leads to distorted perception of tinnitus is highlighted. From this body of evidence, we propose a coherent cognitive behavioral model of tinnitus distress that is more in keeping with contemporary psychological theories of clinical problems (particularly that of insomnia and which postulates a number of behavioral processes that are seen as cognitively mediated. This new model provides testable hypotheses to guide future research to unravel the complex mechanisms underpinning tinnitus distress. It is also well suited to define individual symptomatology and to provide a framework for the delivery of cognitive behavior therapy.

  1. Towards a Cognitive Handoff for the Future Internet: Model-driven Methodology and Taxonomy of Scenarios

    CERN Document Server

    Gonzalez-Horta, Francisco A; Ramirez-Cortes, Juan M; Martinez-Carballido, Jorge; Buenfil-Alpuche, Eldamira

    2011-01-01

    A cognitive handoff is a multipurpose handoff that achieves many desirable features simultaneously; e.g., seamlessness, autonomy, security, correctness, adaptability, etc. But, the development of cognitive handoffs is a challenging task that has not been properly addressed in the literature. In this paper, we discuss the difficulties of developing cognitive handoffs and propose a new model-driven methodology for their systematic development. The theoretical framework of this methodology is the holistic approach, the functional decomposition method, the model-based design paradigm, and the theory of design as scientific problem-solving. We applied the proposed methodology and obtained the following results: (i) a correspondence between handoff purposes and quantitative environment information, (ii) a novel taxonomy of handoff mobility scenarios, and (iii) an original state-based model representing the functional behavior of the handoff process.

  2. A Multiple Deficit Model of Reading Disability and Attention-Deficit/Hyperactivity Disorder: Searching for Shared Cognitive Deficits

    Science.gov (United States)

    McGrath, Lauren M.; Pennington, Bruce F.; Shanahan, Michelle A.; Santerre-Lemmon, Laura E.; Barnard, Holly D.; Willcutt, Erik G.; DeFries, John C.; Olson, Richard K.

    2011-01-01

    Background: This study tests a multiple cognitive deficit model of reading disability (RD), attention-deficit/hyperactivity disorder (ADHD), and their comorbidity. Methods: A structural equation model (SEM) of multiple cognitive risk factors and symptom outcome variables was constructed. The model included phonological awareness as a unique…

  3. 丙纶乳胶丝交织自黏运动绷带基布弹性回复率计算模型%Elastic recovery rate calculation model of interwoven sport bandage fabric by PP and rubber latex thread

    Institute of Scientific and Technical Information of China (English)

    李玉鹏; 王其; 刘昌杰; 郭超群

    2016-01-01

    PP and rubber latex thread interwoven sport bandage fabrics were taken as the research object,the effect of weft yarn and pillar stitch were ignored,and an elastic recovery rate model was established and the calculation formula was gotten based on revision of the model. The amended calculation model can be used to calculate and predict the elastic recovery rate of this kind of sport bandage fabrics, with the deviation of less than 0.3% .%以丙纶乳胶丝交织自黏运动绷带基布为研究对象,忽略丙纶纬纱及编链线圈对绷带基布回弹性的影响,建立运动绷带基布弹性回复率计算模型,通过修正得到其弹性回复率计算式。修正后计算模型的偏差百分率小于0.3%,可用于此类运动绷带基布弹性回复率的实际计算和预测。

  4. A Bottom-up Approach to Opinion Dynamics: a Cognitive Model

    CERN Document Server

    Giardini, Francesca; Conte, Rosaria

    2015-01-01

    The study of opinions - e.g., their formation and change, and their effects on our society - by means of theoretical and numerical models has been one of the main goals of sociophysics until now, but it is one of the defining topics addressed by social psychology and complexity science. Despite the flourishing of different models and theories, several key questions still remain unanswered. Aim of this paper is to provide a cognitively grounded computational model of opinions in which they are described as mental representations and defined in terms of distinctive mental features. We also define how these representations change dynamically through different processes, describing the interplay between mental and social dynamics of opinions. We present two versions of the model, one with discrete opinions (voter model-like), and one with continuous ones (Deffuant-like). By means of numerical simulations, we compare the behaviour of our cognitive model with the classical sociophysical models, showing how consensu...

  5. Cognitive process modelling of controllers in en route air traffic control.

    Science.gov (United States)

    Inoue, Satoru; Furuta, Kazuo; Nakata, Keiichi; Kanno, Taro; Aoyama, Hisae; Brown, Mark

    2012-01-01

    In recent years, various efforts have been made in air traffic control (ATC) to maintain traffic safety and efficiency in the face of increasing air traffic demands. ATC is a complex process that depends to a large degree on human capabilities, and so understanding how controllers carry out their tasks is an important issue in the design and development of ATC systems. In particular, the human factor is considered to be a serious problem in ATC safety and has been identified as a causal factor in both major and minor incidents. There is, therefore, a need to analyse the mechanisms by which errors occur due to complex factors and to develop systems that can deal with these errors. From the cognitive process perspective, it is essential that system developers have an understanding of the more complex working processes that involve the cooperative work of multiple controllers. Distributed cognition is a methodological framework for analysing cognitive processes that span multiple actors mediated by technology. In this research, we attempt to analyse and model interactions that take place in en route ATC systems based on distributed cognition. We examine the functional problems in an ATC system from a human factors perspective, and conclude by identifying certain measures by which to address these problems. This research focuses on the analysis of air traffic controllers' tasks for en route ATC and modelling controllers' cognitive processes. This research focuses on an experimental study to gain a better understanding of controllers' cognitive processes in air traffic control. We conducted ethnographic observations and then analysed the data to develop a model of controllers' cognitive process. This analysis revealed that strategic routines are applicable to decision making.

  6. Models of cognitive behavior in nuclear power plant personnel. A feasibility study: summary of results. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Woods, D.D.; Roth, E.M.; Hanes, L.F.

    1986-07-01

    This report summarizes the results of a feasibility study to determine if the current state of models of human cognitive activities can serve as the basis for improved techniques for predicting human error in nuclear power plants emergency operations. Based on the answer to this question, two subsequent phases of research are planned. Phase II is to develop a model of cognitive activities, and Phase III is to test the model. The feasibility study included an analysis of the cognitive activities that occur in emergency operations and an assessment of the modeling concepts/tools available to capture these cognitive activities. The results indicated that a symbolic processing (or artificial intelligence) model of cognitive activities in nuclear power plants is both desirable and feasible. This cognitive model can be built upon the computational framework provided by an existing artificial intelligence system for medical problem solving, called Caduceus. The resulting cognitive model will increase the capability to capture the human contribution to risk in probabilistic risk assessment studies. Volume 1 summarizes the major findings and conclusions of the study. Volume 2 provides a complete description of the methods and results, including a synthesis of the cognitive activities that occur during emergency operations, and a literature review on cognitive modeling relevant to nuclear power plants. 19 refs.

  7. Social disruption alters pain and cognition in an animal model of multiple sclerosis.

    Science.gov (United States)

    Linsenbardt, H R; Cook, J L; Young, E E; Vichaya, E G; Young, C R; Reusser, N M; Storts, R; Welsh, C J; Meagher, M W

    2015-11-15

    Although pain and cognitive deficits are widespread and debilitating symptoms of multiple sclerosis (MS), they remain poorly understood. Theiler's murine encephalomyelitis virus (TMEV) infection is an animal model of MS where disease course is exacerbated by prior stressors. Here chronic infection coupled with prior social stress increased pain behavior and impaired hippocampal-dependent memory consolidation during the demyelinating phase of disease in SJL mice. These results suggest that the TMEV model may be useful in investigating pain and cognitive impairments in MS. However, in contrast to prior Balb/cJ studies, stress failed to consistently alter behavioral and physiological indicators of disease course.

  8. Modeling Enrollment in and Completion of Vocational Education: The role of cognitive and non-cognitive skills by program type

    DEFF Research Database (Denmark)

    Stratton, Leslie S.; Gupta, Nabanita Datta; Reimer, David

    and right censoring. Cognitive skills are captured with math and language exam scores, non-cognitive skills with teacher-assigned grades. We find that all skills are inversely related to enrollment and math scores are positively related to certification for all VET programs. Language skills are, however......We examine the role of cognitive and non-cognitive skills on enrollment in and completion of three types of vocational training (VET): education/health, technical, and business. Using two nine-year panels of Danish youths, estimation proceeds separately by gender, controlling for selection......, inversely related to completion for technical VET and non-cognitive skills are important only for business VET....

  9. Sleep deprivation and sustained attention performance: integrating mathematical and cognitive modeling.

    Science.gov (United States)

    Gunzelmann, Glenn; Gross, Joshua B; Gluck, Kevin A; Dinges, David F

    2009-07-01

    A long history of research has revealed many neurophysiological changes and concomitant behavioral impacts of sleep deprivation, sleep restriction, and circadian rhythms. Little research, however, has been conducted in the area of computational cognitive modeling to understand the information processing mechanisms through which neurobehavioral factors operate to produce degradations in human performance. Our approach to understanding this relationship is to link predictions of overall cognitive functioning, or alertness, from existing biomathematical models to information processing parameters in a cognitive architecture, leveraging the strengths from each to develop a more comprehensive explanation. The integration of these methodologies is used to account for changes in human performance on a sustained attention task across 88 h of total sleep deprivation. The integrated model captures changes due to time awake and circadian rhythms, and it also provides an account for underlying changes in the cognitive processes that give rise to those effects. The results show the potential for developing mechanistic accounts of how fatigue impacts cognition, and they illustrate the increased explanatory power that is possible by combining theoretical insights from multiple methodologies.

  10. Surgery results in exaggerated and persistent cognitive decline in a rat model of the Metabolic Syndrome.

    Science.gov (United States)

    Feng, Xiaomei; Degos, Vincent; Koch, Lauren G; Britton, Steven L; Zhu, Yinggang; Vacas, Susana; Terrando, Niccolò; Nelson, Jeffrey; Su, Xiao; Maze, Mervyn

    2013-05-01

    Postoperative cognitive decline can be reproduced in animal models. In a well-validated rat model of the Metabolic Syndrome, we sought to investigate whether surgery induced a more severe and persistent form of cognitive decline similar to that noted in preliminary clinical studies. In rats that had been selectively bred for low and high exercise endurance, the low capacity runners (LCR) exhibited features of Metabolic Syndrome (obesity, dyslipidemia, insulin resistance, and hypertension). Tibial fracture surgery was performed under isoflurane anesthesia in LCR and high capacity runner (HCR) rats and cognitive function was assessed postoperatively in a trace-fear conditioning paradigm and Morris Water Maze; non-operated rats were exposed to anesthesia and analgesia (sham). Group sizes were n = 6. On postoperative D7, LCR rats had shorter freezing times than postoperative HCR rats. Five months postoperatively, LCR rats had a flatter learning trajectory and took longer to locate the submerged platform than postoperative HCR rats; dwell-time in the target quadrant in a probe trial was shorter in the postoperative LCR compared to HCR rats. LCR and HCR sham rats did not differ in any test. Postoperatively, LCR rats diverged from HCR rats exhibiting a greater decline in memory, acutely, with persistent learning and memory decline, remotely; this could not be attributed to changes in locomotor or swimming performance. This Metabolic Syndrome animal model of surgery-induced cognitive decline corroborates, with high fidelity, preliminary findings of postoperative cognitive dysfunction in Metabolic Syndrome patients.

  11. Differential Item Functioning Assessment in Cognitive Diagnostic Modeling: Application of the Wald Test to Investigate DIF in the DINA Model

    Science.gov (United States)

    Hou, Likun; de la Torre, Jimmy; Nandakumar, Ratna

    2014-01-01

    Analyzing examinees' responses using cognitive diagnostic models (CDMs) has the advantage of providing diagnostic information. To ensure the validity of the results from these models, differential item functioning (DIF) in CDMs needs to be investigated. In this article, the Wald test is proposed to examine DIF in the context of CDMs. This study…

  12. The structural model of pain, cognitive strategies, and negative emotions in functional gastrointestinal disorders

    Directory of Open Access Journals (Sweden)

    Mina Mazaheri

    2016-01-01

    Full Text Available Background: Patients with functional gastrointestinal disorders (FGIDs may use specific coping strategies. We intend to provide a mediating role of the relationship between pain (intensity and acceptance, cognitive emotion regulation strategies, and negative emotions in patients with FGIDs. Materials and Methods: Participants were 176 inpatients, all experiencing significant FGIDs symptomatology as confirmed by gastroenterologists. Patients completed data on cognitive emotion regulation questionnaire, short form of depression, anxiety, stress scale, chronic pain acceptance questionnaire-revised, and pain intensity scale. Data were analyzed using structural equation modeling method. Results: The pain intensity had significantly direct effect on cognitive emotion regulation strategies and indirect effect on negative emotions. Besides, the mediating role of negative emotions in the relationship between the strategies and pain acceptance were supported, whereas indirect relationships between pain intensity and acceptance through cognitive strategies were not confirmed. Conclusion: The results of the study emphasize the role of pain intensity in the development of negative emotions through cognitive strategies and the role of the strategies in pain acceptance through negative emotions. In fact, cognitive strategies to be related to pain and emotions.

  13. Influence of Thread Pitch, Helix Angle, and Compactness on Micromotion of Immediately Loaded Implants in Three Types of Bone Quality: A Three-Dimensional Finite Element Analysis

    Directory of Open Access Journals (Sweden)

    Pan Ma

    2014-01-01

    Full Text Available This study investigated the influence of thread pitch, helix angle, and compactness on micromotion in immediately loaded implants in bone of varying density (D2, D3, and D4. Five models of the three-dimensional finite element (0.8 mm pitch, 1.6 mm pitch, 2.4 mm pitch, double-threaded, and triple-threaded implants in three types of bone were created using Pro/E, Hypermesh, and ABAQUS software. The study had three groups: Group 1, different pitches (Pitch Group; Group 2, same compactness but different helix angles (Angle Group; and Group 3, same helix angle but different compactness (Compact Group. Implant micromotion was assessed as the comprehensive relative displacement. We found that vertical relative displacement was affected by thread pitch, helix angle, and compactness. Under vertical loading, displacement was positively correlated with thread pitch and helix angle but negatively with compactness. Under horizontal loading in D2, the influence of pitch, helix angle, and compactness on implant stability was limited; however, in D3 and D4, the influence of pitch, helix angle, and compactness on implant stability is increased. The additional evidence was provided that trabecular bone density has less effect on implant micromotion than cortical bone thickness. Bone type amplifies the influence of thread pattern on displacement.

  14. Towards improved animal models for evaluating social cognition and its disruption in schizophrenia: the CNTRICS initiative.

    Science.gov (United States)

    Millan, Mark J; Bales, Karen L

    2013-11-01

    Social cognition refers to processes used to monitor and interpret social signals from others, to decipher their state of mind, emotional status and intentions, and select appropriate social behaviour. Social cognition is sophisticated in humans, being embedded with verbal language and enacted in a complex cultural environment. Its disruption characterises the entire course of schizophrenia and is correlated with poor functional outcome. Further, deficits in social cognition are related to impairment in other cognitive domains, positive symptoms (paranoia and delusions) and negative symptoms (social withdrawal and reduced motivation). In light of the significance and inadequate management of social cognition deficits, there is a need for translatable experimental procedures for their study, and identification of effective pharmacotherapy. No single paradigm captures the multi-dimensional nature of social cognition, and procedures for assessing ability to infer mental states are not well-developed for experimental therapeutic settings. Accordingly, a recent CNTRICS meeting prioritised procedures for measuring a specific construct: "acquisition and recognition of affective (emotional) states", coupled to individual recognition. Two complementary paradigms for refinement were identified: social recognition/preference in rodents, and visual tracking of social scenes in non-human primates (NHPs). Social recognition is disrupted in genetic, developmental or pharmacological disease models for schizophrenia, and performance in both procedures is improved by the neuropeptide oxytocin. The present article surveys a broad range of procedures for studying social cognition in rodents and NHPs, discusses advantages and drawbacks, and focuses on development of social recognition/preference and gaze-following paradigms for improved study of social cognition deficits in schizophrenia and their potential treatment.

  15. Supporting productive thinking: The semiotic context for Cognitive Systems Engineering (CSE).

    Science.gov (United States)

    Flach, John

    2017-03-01

    The central thesis of this paper is that Rasmussen framed his approach to Cognitive Systems Engineering from the perspective of a Triadic Semiotic Model. This frame became the context for integrating multiple intellectual threads including Control Theory, Information Theory, Ecological Psychology, and Gestalt Psychology into a coherent theoretical framework. The case is made that the triadic semiotic framework is essential for a complete appreciation of the constructs that were central to Rasmussen's approach: Abstraction Hierarchy, Skill-Rules-Knowledge Model, Ecological Interface Design, and Proactive Risk Management.

  16. Computational modeling for addiction medicine: From cognitive models to clinical applications.

    Science.gov (United States)

    Ahn, Woo Young; Dai, Junyi; Vassileva, Jasmin; Busemeyer, Jerome R; Stout, Julie C

    2016-01-01

    Decision-making tasks that have good ecological validity, such as simulated gambling tasks, are complex, and performance on these tasks represents a synthesis of several different underlying psychological processes, such as learning from experience, and motivational processes such as sensitivity to reward and punishment. Cognitive models can be used to break down performance on these tasks into constituent processes, which can then be assessed and studied in relation to clinical characteristics and neuroimaging outcomes. Whether it will be possible to improve treatment success by targeting these constituent processes more directly remains unexplored. We review the development and testing of the Expectancy-Valence and Prospect-Valence Learning models from the past 10 years or so using simulated gambling tasks, in particular the Iowa and Soochow Gambling Tasks. We highlight the issues of model generalizability and parameter consistency, and we describe findings obtained from these models in clinical populations including substance use disorders. We then suggest future directions for this research that will help to bring its utility to broader research and clinical applications.

  17. Multi-threaded software framework development for the ATLAS experiment

    Science.gov (United States)

    Stewart, G. A.; Baines, J.; Bold, T.; Calafiura, P.; Dotti, A.; Farrell, S. A.; Leggett, C.; Malon, D.; Ritsch, E.; Snyder, S.; Tsulaia, V.; Van Gemmeren, P.; Wynne, B. M.; ATLAS Experiment,the

    2016-10-01

    ATLAS's current software framework, Gaudi/Athena, has been very successful for the experiment in LHC Runs 1 and 2. However, its single-threaded design has been recognised for some time to be increasingly problematic as CPUs have increased core counts and decreased available memory per core. Even the multi-process version of Athena, AthenaMP, will not scale to the range of architectures we expect to use beyond Run2. ATLAS examined the requirements on an updated multi-threaded framework and laid out plans for a new framework, including better support for High Level Trigger use cases, in 2014. In this paper we report on our progress in developing the new multi-threaded task parallel extension of Athena, AthenaMT. Implementing AthenaMT has required many significant code changes. Progress has been made in updating key concepts of the framework, allowing different levels of thread safety in algorithmic code. Substantial advances have also been made in implementing a data flow centric design, as well as on the development of the new ‘event views’ infrastructure. These event views support partial event processing and are an essential component to support the High Level Trigger's processing of certain regions of interest. A major effort has also been invested to have an early version of AthenaMT that can run simulation on many core architectures, which has augmented the understanding gained from work on earlier ATLAS demonstrators.

  18. Usefulness of Gold Thread Implantation for Crow’s

    Directory of Open Access Journals (Sweden)

    Woo Seob Kim

    2012-01-01

    Full Text Available Background Conservative techniques designed to block or delay the aging process have beenutilized in various ways for many years. However, their effects can be relatively minimal andshort-term in most cases compared to surgery. The objective of this study was to evaluate theefficacy and safety of gold thread implantation for the treatment of periorbital wrinkles.Methods A total of 78 consecutive patients who showed mild to severe periorbital wrinkleswere deemed appropriate candidates, including 69 women and 9 men ranging from 31 to 59years (mean, 47 years. Six gold threads about 4 cm in length were inserted subdermally ineach patient at intervals of about 0.5 cm. Follow-up assessments were performed 1, 4, and 12weeks after the procedure. The efficacy was rated by the physician using the Wrinkle SeverityRating Scale and patients who made global assessments of changes in periorbital wrinklesusing the Visual Analog Scale. Adverse events were monitored throughout the course of thestudy.Results The patients showed significant improvements after the procedure. There were minorcomplications such as foreign body sensation in the eye (2.63% and eye pain (1.32% thatimproved spontaneously without any specific treatments.Conclusions Subdermal implantation of gold thread improves the appearance of periorbitalwrinkles and does not appear to have serious side effects. Insertion of gold thread may be aneffective and safe method for facial rejuvenation.

  19. Structural Analysis of Taper-Threaded Rebar Couplers

    Energy Technology Data Exchange (ETDEWEB)

    Chu, Seok Jae [Univ. of Ulsan, Ulsan (Korea, Republic of); Kwon, Hyuk Mo; Seo, Sang Hwan [Sammi Precision Co. Ltd., Ulsan (Korea, Republic of)

    2014-05-15

    A number of rebar couplers were developed by the leading companies. The information about the products is available from the company website. However, the theory on the taper-threaded coupler is not available. In this paper, the mechanics of the taper-thread was developed to understand the effect of the tightening torque. Structural analysis of our own newly developed rebar coupler was done to improve the strength of the coupler. The taper-threaded rebar coupler was analyzed. The tightening of the rebar into the coupler developed a circumferential stress in the coupler. The circumferential stress depends on the coefficient of friction as well as the tightening torque. The circumferential stress is less than the allowable stress 20 kgf/mm{sup 2} of the material for the coefficient of friction greater than 0.1. The tightening of the rebar into the coupler and the subsequent tensioning was simulated using CATIA. Linear elastic analysis considering contact was done. The tightening of the taper-threaded rebar developed a uniform stress distribution in both standard coupler and position coupler. On the other hand, the tightening of the nut in the axial direction developed a non-uniform stress distribution. Similarly the tensioning also developed a non-uniform stress distribution.

  20. Kinetic Study of [2]Pseudorotaxane Formation with an Asymmetrical Thread.

    Science.gov (United States)

    Quiroga, Miguel; Parajó, Mercedes; Rodríguez-Dafonte, Pedro; García-Río, Luis

    2016-06-28

    Kinetic and thermodynamic studies on cyclodextrin (CD)-based [2]pseudorotaxane formation have been carried out by a combination of NMR and calorimetric techniques using bolaform surfactants as axles. Experimental evidence of the formation of an external complex between the trimethylammonium head groups of the axle and the external hydrogen atoms of α-cyclodextrin (α-CD) is reported. Inclusion of this external complex in the reaction pathway allows us to explain the kinetic behavior as well as the nonlinear dependence of the observed rate constant on CD concentrations. The equilibrium constant for [2]pseudorotaxane formation is strongly affected by the spacer length of the axle. This effect is a consequence of increasing rotaxane stability because the threading rate constant is almost independent of the spacer length, but dethreading strongly decreases on increasing the axle size. Using a nonsymmetrical axle with tripropyl and trimethylammonium cations precludes CD threading by the large head side. CDs will thread this asymmetrical bolaform by both their wide and narrow sides, yielding two isomeric [2]pseudorotaxanes. Threading by the wide side of the CD is 60% more favorable than that by the narrow one, but dethreading rate constants are the same for both isomers.