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Sample records for adaptive life simulator

  1. Adaptive life simulator: A novel approach to modeling the cardiovascular system

    Kangas, L.J.; Keller, P.E.; Hashem, S. [and others

    1995-06-01

    In this paper, an adaptive life simulator (ALS) is introduced. The ALS models a subset of the dynamics of the cardiovascular behavior of an individual by using a recurrent artificial neural network. These models are developed for use in applications that require simulations of cardiovascular systems, such as medical mannequins, and in medical diagnostic systems. This approach is unique in that each cardiovascular model is developed from physiological measurements of an individual. Any differences between the modeled variables and the actual variables of an individual can subsequently be used for diagnosis. This approach also exploits sensor fusion applied to biomedical sensors. Sensor fusion optimizes the utilization of the sensors. The advantage of sensor fusion has been demonstrated in applications including control and diagnostics of mechanical and chemical processes.

  2. Adaptive Sampling in Hierarchical Simulation

    Knap, J; Barton, N R; Hornung, R D; Arsenlis, A; Becker, R; Jefferson, D R

    2007-07-09

    We propose an adaptive sampling methodology for hierarchical multi-scale simulation. The method utilizes a moving kriging interpolation to significantly reduce the number of evaluations of finer-scale response functions to provide essential constitutive information to a coarser-scale simulation model. The underlying interpolation scheme is unstructured and adaptive to handle the transient nature of a simulation. To handle the dynamic construction and searching of a potentially large set of finer-scale response data, we employ a dynamic metric tree database. We study the performance of our adaptive sampling methodology for a two-level multi-scale model involving a coarse-scale finite element simulation and a finer-scale crystal plasticity based constitutive law.

  3. Life history adaptations to seasonality

    Varpe, Øystein Heggernes

    2007-01-01

    The thesis contains studies of animal life histories at high latitudes. Several topics are covered; from ecosystem consequences of life histories to tests of specific behavioural predictions put forward based on life history arguments. Work on complete life histories is also included in an attempt to understand the evolution of capital and income breeding in marine copepods. My main research questions, followed by main topics and findings, are as follows: • How are seasonal ...

  4. Time Simulation of Bone Adaptation

    Bagge, Mette

    1998-01-01

    The structural adaptation of a three-dimensional finite element model ofthe proximal femur is considered. Presuming the bone possesses the optimalstructure under the given loads, the bone material distribution is foundby minimizing the strain energy averaged over ten load cases with avolume...... constraint. Theoptimized design is used as a start-configuration for the remodelingsimulation.The parameter characterizing the equilibrium level where no remodeling occurs is estimated from the optimization parameters.The loads vary in magnitude, location and direction simulating timedependent loading. The...

  5. The Adaptive Multi-scale Simulation Infrastructure

    Tobin, William R. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    2015-09-01

    The Adaptive Multi-scale Simulation Infrastructure (AMSI) is a set of libraries and tools developed to support the development, implementation, and execution of general multimodel simulations. Using a minimal set of simulation meta-data AMSI allows for minimally intrusive work to adapt existent single-scale simulations for use in multi-scale simulations. Support for dynamic runtime operations such as single- and multi-scale adaptive properties is a key focus of AMSI. Particular focus has been spent on the development on scale-sensitive load balancing operations to allow single-scale simulations incorporated into a multi-scale simulation using AMSI to use standard load-balancing operations without affecting the integrity of the overall multi-scale simulation.

  6. Adaptive Multilevel Monte Carlo Simulation

    Hoel, H

    2011-08-23

    This work generalizes a multilevel forward Euler Monte Carlo method introduced in Michael B. Giles. (Michael Giles. Oper. Res. 56(3):607–617, 2008.) for the approximation of expected values depending on the solution to an Itô stochastic differential equation. The work (Michael Giles. Oper. Res. 56(3):607– 617, 2008.) proposed and analyzed a forward Euler multilevelMonte Carlo method based on a hierarchy of uniform time discretizations and control variates to reduce the computational effort required by a standard, single level, Forward Euler Monte Carlo method. This work introduces an adaptive hierarchy of non uniform time discretizations, generated by an adaptive algorithmintroduced in (AnnaDzougoutov et al. Raùl Tempone. Adaptive Monte Carlo algorithms for stopped diffusion. In Multiscale methods in science and engineering, volume 44 of Lect. Notes Comput. Sci. Eng., pages 59–88. Springer, Berlin, 2005; Kyoung-Sook Moon et al. Stoch. Anal. Appl. 23(3):511–558, 2005; Kyoung-Sook Moon et al. An adaptive algorithm for ordinary, stochastic and partial differential equations. In Recent advances in adaptive computation, volume 383 of Contemp. Math., pages 325–343. Amer. Math. Soc., Providence, RI, 2005.). This form of the adaptive algorithm generates stochastic, path dependent, time steps and is based on a posteriori error expansions first developed in (Anders Szepessy et al. Comm. Pure Appl. Math. 54(10):1169– 1214, 2001). Our numerical results for a stopped diffusion problem, exhibit savings in the computational cost to achieve an accuracy of ϑ(TOL),from(TOL−3), from using a single level version of the adaptive algorithm to ϑ(((TOL−1)log(TOL))2).

  7. Lamarck and the adaptive conservation of life

    Galera, Andrés

    2009-12-01

    Full Text Available This paper studies Lamarck’s evolutionary thought through four analytic elements. Firstly, Lamarckian construction of a founding evolutionary archetype. Secondly, the interpretation of nature as a material system where the organic change represents a continuous process aimed at the adaptative conservation of life. Thirdly, the definition of a genealogical process on the origin of species which identifies the natural method. Fourthly, the redefinition of the concept of species applying the arguments of temporary relativity and individual instability.

    En este artículo se estudia el ideario evolucionista lamarckiano desarrollando cuatro elementos analíticos. Primero, la elaboración de un arquetipo evolutivo fundacional. Segundo, la interpretación de la naturaleza como un sistema material donde el cambio orgánico da sentido a un proceso continuo dirigido a la conservación de la vida. Tercero, la definición de un principio genealógico sobre el origen de las especies que identifica el método natural. Cuarto, la reformulación del concepto de especie utilizando los argumentos de relatividad temporal e inestabilidad individual.

  8. Adaptive simulated annealing (ASA): Lessons learned

    Ingber, L.

    2000-01-01

    Adaptive simulated annealing (ASA) is a global optimization algorithm based on an associated proof that the parameter space can be sampled much more efficiently than by using other previous simulated annealing algorithms. The author's ASA code has been publicly available for over two years. During this time the author has volunteered to help people via e-mail, and the feedback obtained has been used to further develop the code. Some lessons learned, in particular some which are relevant to ot...

  9. DKIST Adaptive Optics System: Simulation Results

    Marino, Jose; Schmidt, Dirk

    2016-05-01

    The 4 m class Daniel K. Inouye Solar Telescope (DKIST), currently under construction, will be equipped with an ultra high order solar adaptive optics (AO) system. The requirements and capabilities of such a solar AO system are beyond those of any other solar AO system currently in operation. We must rely on solar AO simulations to estimate and quantify its performance.We present performance estimation results of the DKIST AO system obtained with a new solar AO simulation tool. This simulation tool is a flexible and fast end-to-end solar AO simulator which produces accurate solar AO simulations while taking advantage of current multi-core computer technology. It relies on full imaging simulations of the extended field Shack-Hartmann wavefront sensor (WFS), which directly includes important secondary effects such as field dependent distortions and varying contrast of the WFS sub-aperture images.

  10. Adaptability and Life Satisfaction: The Moderating Role of Social Support

    Zhou, Mi; Lin, Weipeng

    2016-01-01

    The purpose of this study was to investigate the moderating role of social support in the relationship between adaptability and life satisfaction. Data were collected from 99 undergraduate freshmen in a Chinese university using a lagged design with a 1-month interval. Results demonstrated that social support moderated the relation between adaptability and life satisfaction, such that the positive relation between adaptability and life satisfaction was stronger for individuals with higher levels of social support than for individuals with lower levels of social support. The theoretical and practical implications of this result are discussed. PMID:27516753

  11. Adaptive Optics Simulations for Siding Spring

    Goodwin, Michael; Lambert, Andrew

    2012-01-01

    Using an observational derived model optical turbulence profile (model-OTP) we have investigated the performance of Adaptive Optics (AO) at Siding Spring Observatory (SSO), Australia. The simulations cover the performance for AO techniques of single conjugate adaptive optics (SCAO), multi-conjugate adaptive optics (MCAO) and ground-layer adaptive optics (GLAO). The simulation results presented in this paper predict the performance of these AO techniques as applied to the Australian National University (ANU) 2.3 m and Anglo-Australian Telescope (AAT) 3.9 m telescopes for astronomical wavelength bands J, H and K. The results indicate that AO performance is best for the longer wavelengths (K-band) and in the best seeing conditions (sub 1-arcsecond). The most promising results are found for GLAO simulations (field of view of 180 arcsecs), with the field RMS for encircled energy 50% diameter (EE50d) being uniform and minimally affected by the free-atmosphere turbulence. The GLAO performance is reasonably good over...

  12. Mandela's Meanings: A Translated and Adapted Life

    Carli Coetzee

    2014-01-01

    This paper reflects on the seeming ubiquity of representations of Nelson Mandela, and contrasts this with the years of silence and facelessness that have entered the mythological sphere - the 18 years he spent on Robben Island. The period when Mandela (through text or image) circulated the least has now in fact become the centrepiece of the narrative of his life. In this paper, I reconstitute some of the literary and photographic fragments of that era, one for which the biographical record is...

  13. Adaptive System Modeling for Spacecraft Simulation

    Thomas, Justin

    2011-01-01

    This invention introduces a methodology and associated software tools for automatically learning spacecraft system models without any assumptions regarding system behavior. Data stream mining techniques were used to learn models for critical portions of the International Space Station (ISS) Electrical Power System (EPS). Evaluation on historical ISS telemetry data shows that adaptive system modeling reduces simulation error anywhere from 50 to 90 percent over existing approaches. The purpose of the methodology is to outline how someone can create accurate system models from sensor (telemetry) data. The purpose of the software is to support the methodology. The software provides analysis tools to design the adaptive models. The software also provides the algorithms to initially build system models and continuously update them from the latest streaming sensor data. The main strengths are as follows: Creates accurate spacecraft system models without in-depth system knowledge or any assumptions about system behavior. Automatically updates/calibrates system models using the latest streaming sensor data. Creates device specific models that capture the exact behavior of devices of the same type. Adapts to evolving systems. Can reduce computational complexity (faster simulations).

  14. Local adaptation in brown trout early life-history traits: implications for climate change adaptability

    Jensen, L.F.; Hansen, Michael Møller; Pertoldi, C.;

    2008-01-01

    adapt. Temperature-related adaptability in traits related to phenology and early life history are expected to be particularly important in salmonid fishes. We focused on the latter and investigated whether four populations of brown trout (Salmo trutta) are locally adapted in early life-history traits......) for two traits, indicating local adaptation. A temperature effect was observed for three traits. However, this effect varied among populations due to locally adapted reaction norms, corresponding to the temperature regimes experienced by the populations in their native environments. Additive genetic...... variance and heritable variation in phenotypic plasticity suggest that although increasing temperatures are likely to affect some populations negatively, they may have the potential to adapt to changing temperature regimes.  ...

  15. Adaptive wavelet simulation of global ocean dynamics

    N. K.-R. Kevlahan

    2015-07-01

    Full Text Available In order to easily enforce solid-wall boundary conditions in the presence of complex coastlines, we propose a new mass and energy conserving Brinkman penalization for the rotating shallow water equations. This penalization does not lead to higher wave speeds in the solid region. The error estimates for the penalization are derived analytically and verified numerically for linearized one dimensional equations. The penalization is implemented in a conservative dynamically adaptive wavelet method for the rotating shallow water equations on the sphere with bathymetry and coastline data from NOAA's ETOPO1 database. This code could form the dynamical core for a future global ocean model. The potential of the dynamically adaptive ocean model is illustrated by using it to simulate the 2004 Indonesian tsunami and wind-driven gyres.

  16. Adaptive prolonged postreproductive life span in killer whales.

    Foster, Emma A; Franks, Daniel W; Mazzi, Sonia; Darden, Safi K; Balcomb, Ken C; Ford, John K B; Croft, Darren P

    2012-09-14

    Prolonged life after reproduction is difficult to explain evolutionarily unless it arises as a physiological side effect of increased longevity or it benefits related individuals (i.e., increases inclusive fitness). There is little evidence that postreproductive life spans are adaptive in nonhuman animals. By using multigenerational records for two killer whale (Orcinus orca) populations in which females can live for decades after their final parturition, we show that postreproductive mothers increase the survival of offspring, particularly their older male offspring. This finding may explain why female killer whales have evolved the longest postreproductive life span of all nonhuman animals. PMID:22984064

  17. Simulating Astronomical Adaptive Optics Systems Using Yao

    Rigaut, François; Van Dam, Marcos

    2013-12-01

    Adaptive Optics systems are at the heart of the coming Extremely Large Telescopes generation. Given the importance, complexity and required advances of these systems, being able to simulate them faithfully is key to their success, and thus to the success of the ELTs. The type of systems envisioned to be built for the ELTs cover most of the AO breeds, from NGS AO to multiple guide star Ground Layer, Laser Tomography and Multi-Conjugate AO systems, with typically a few thousand actuators. This represents a large step up from the current generation of AO systems, and accordingly a challenge for existing AO simulation packages. This is especially true as, in the past years, computer power has not been following Moore's law in its most common understanding; CPU clocks are hovering at about 3GHz. Although the use of super computers is a possible solution to run these simulations, being able to use smaller machines has obvious advantages: cost, access, environmental issues. By using optimised code in an already proven AO simulation platform, we were able to run complex ELT AO simulations on very modest machines, including laptops. The platform is YAO. In this paper, we describe YAO, its architecture, its capabilities, the ELT-specific challenges and optimisations, and finally its performance. As an example, execution speed ranges from 5 iterations per second for a 6 LGS 60x60 subapertures Shack-Hartmann Wavefront sensor Laser Tomography AO system (including full physical image formation and detector characteristics) up to over 30 iterations/s for a single NGS AO system.

  18. Adaptive resolution simulation in equilibrium and beyond

    Wang, H.; Agarwal, A.

    2015-09-01

    In this paper, we investigate the equilibrium statistical properties of both the force and potential interpolations of adaptive resolution simulation (AdResS) under the theoretical framework of grand-canonical like AdResS (GC-AdResS). The thermodynamic relations between the higher and lower resolutions are derived by considering the absence of fundamental conservation laws in mechanics for both branches of AdResS. In order to investigate the applicability of AdResS method in studying the properties beyond the equilibrium, we demonstrate the accuracy of AdResS in computing the dynamical properties in two numerical examples: The velocity auto-correlation of pure water and the conformational relaxation of alanine dipeptide dissolved in water. Theoretical and technical open questions of the AdResS method are discussed in the end of the paper.

  19. Simulation of Biochemical Pathway Adaptability Using Evolutionary Algorithms

    Bosl, W J

    2005-01-26

    The systems approach to genomics seeks quantitative and predictive descriptions of cells and organisms. However, both the theoretical and experimental methods necessary for such studies still need to be developed. We are far from understanding even the simplest collective behavior of biomolecules, cells or organisms. A key aspect to all biological problems, including environmental microbiology, evolution of infectious diseases, and the adaptation of cancer cells is the evolvability of genomes. This is particularly important for Genomes to Life missions, which tend to focus on the prospect of engineering microorganisms to achieve desired goals in environmental remediation and climate change mitigation, and energy production. All of these will require quantitative tools for understanding the evolvability of organisms. Laboratory biodefense goals will need quantitative tools for predicting complicated host-pathogen interactions and finding counter-measures. In this project, we seek to develop methods to simulate how external and internal signals cause the genetic apparatus to adapt and organize to produce complex biochemical systems to achieve survival. This project is specifically directed toward building a computational methodology for simulating the adaptability of genomes. This project investigated the feasibility of using a novel quantitative approach to studying the adaptability of genomes and biochemical pathways. This effort was intended to be the preliminary part of a larger, long-term effort between key leaders in computational and systems biology at Harvard University and LLNL, with Dr. Bosl as the lead PI. Scientific goals for the long-term project include the development and testing of new hypotheses to explain the observed adaptability of yeast biochemical pathways when the myosin-II gene is deleted and the development of a novel data-driven evolutionary computation as a way to connect exploratory computational simulation with hypothesis

  20. Using Site Testing Data for Adaptive Optics Simulations

    Herriot, Glen; Andersen, David; Conan, Rod; Ellerbroek, Brent; Gilles, Luc; Hickson, Paul; Jackson, Kate; Lardière, Olivier; Pfrommer, Thomas; Véran, Jean-Pierre; Wang, Lianqi

    2011-01-01

    Astronomical Site testing data plays a vital role in the simulation, design, evaluation and operation of adaptive optics systems for large telescope. We present the example of TMT and its first light facilitiy adaptive optics system NFIRAOS, and illustrate the many simulations done based on site testing data.

  1. On the Simulation of Adaptive Measurements via Postselection

    Dhillon, Vikram

    2011-01-01

    In this note we address the question of whether any any quantum computational model that allows adaptive measurements can be simulated by a model that allows postselected measurements. We argue in the favor of this question and prove that adaptive measurements can be simulated by postselection. We also discuss some potentially stunning consequences of this result such as the ability to solve #P problems.

  2. Exploring the Use of Adaptively Restrained Particles for Graphics Simulations

    Pierre-Luc Manteaux; Fran\\xe7ois Faure; Stephane Redon; Marie-Paule Cani

    2013-01-01

    International audience In this paper, we explore the use of Adaptively Restrained (AR) particles for graphics simulations. Contrary to previous methods, Adaptively Restrained Particle Simulations (ARPS) do not adapt time or space sampling, but rather switch the positional degrees of freedom of particles on and off, while letting their momenta evolve. Therefore, inter-particles forces do not have to be updated at each time step, in contrast with traditional methods that spend a lot of time ...

  3. ADAPTIVE CHARACTERISTICS OF HERONS PLUMAGE FOR THEIR WAY OF LIFE

    Koshelev V. A.

    2011-12-01

    Full Text Available Feather cover of each bird species reflects spectra of species, age, sex and environmental attributes defined the phylogeny of taxa, habitat and life patterns. In turn, many ecological phenomena in the birds’ life patterns are directly dependent on the state of plumage (e.g., time of breeding, seasonal migration, roost flights. For the first time the quantitative characterization of six heron species' plumage were done as well as the description of powder down feathers. The adaptive features of feathers and various types of heron’s plumages were discussed.The structure of contour feathers of herons is related to the peculiarities of species life pattern. All the species have a relatively small number of contour feathers, despite their large body size. According to this index the herons are more similar to typical wading birds (gulls, sandpipers than for waterfowl. The total number of heron feathers slightly increase in winter, because they are migratory species. Structure of contour feathers of herons corresponds to that of other waterbirds. The rod is not bent, the feathers are large, and the mounting angle to the surface of the body is little. The cores of abdominal feather fracts reduce heat transfer and can be regarded as an adaptation factor to aquatic environment.Buoyancy is provided by heron’s feathers insignificantly, in contrast to the typical waterfowl species. Significant subcutaneous fat stores are typical for herons in spring, autumn and winter, increased buoyancy and being the energy reserves provide thermoregulation in cold environment. Our data indicate weak adaptation of herons’ plumage to aquatic environments, but also confirm its insulating properties, which is prove the herons semi-aquatic rather than aquatic life patterns.Due to color of plumage some three groups of herons were considered: white, mottled and camouflaged. Coloration of second and third group performs a protective function. We didn’t found a clear

  4. The brine shrimp Artemia: adapted to critical life conditions

    Gonzalo M Gajardo

    2012-06-01

    Full Text Available The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to perceive forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity that are able to maintain the population under suitable conditions.At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism. The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress

  5. The Brine Shrimp Artemia: Adapted to Critical Life Conditions

    Gajardo, Gonzalo M.; Beardmore, John A.

    2012-01-01

    The brine shrimp Artemia is a micro-crustacean, well adapted to the harsh conditions that severely hypersaline environments impose on survival and reproduction. Adaptation to these conditions has taken place at different functional levels or domains, from the individual (molecular-cellular-physiological) to the population level. Such conditions are experienced by very few equivalent macro-planktonic organisms; thus, Artemia can be considered a model animal extremophile offering a unique suite of adaptations that are the focus of this review. The most obvious is a highly efficient osmoregulation system to withstand up to 10 times the salt concentration of ordinary seawater. Under extremely critical environmental conditions, for example when seasonal lakes dry-out, Artemia takes refuge by producing a highly resistant encysted gastrula embryo (cyst) capable of severe dehydration enabling an escape from population extinction. Cysts can be viewed as gene banks that store a genetic memory of historical population conditions. Their occurrence is due to the evolved ability of females to “perceive” forthcoming unstable environmental conditions expressed by their ability to switch reproductive mode, producing either cysts (oviparity) when environmental conditions become deleterious or free-swimming nauplii (ovoviviparity) that are able to maintain the population under suitable conditions. At the population level the trend is for conspecific populations to be fragmented into locally adapted populations, whereas species are restricted to salty lakes in particular regions (regional endemism). The Artemia model depicts adaptation as a complex response to critical life conditions, integrating and refining past and present experiences at all levels of organization. Although we consider an invertebrate restricted to a unique environment, the processes to be discussed are of general biological interest. Finally, we highlight the benefits of understanding the stress response of

  6. Self-adaptive genetic algorithms with simulated binary crossover.

    Deb, K; Beyer, H G

    2001-01-01

    Self-adaptation is an essential feature of natural evolution. However, in the context of function optimization, self-adaptation features of evolutionary search algorithms have been explored mainly with evolution strategy (ES) and evolutionary programming (EP). In this paper, we demonstrate the self-adaptive feature of real-parameter genetic algorithms (GAs) using a simulated binary crossover (SBX) operator and without any mutation operator. The connection between the working of self-adaptive ESs and real-parameter GAs with the SBX operator is also discussed. Thereafter, the self-adaptive behavior of real-parameter GAs is demonstrated on a number of test problems commonly used in the ES literature. The remarkable similarity in the working principle of real-parameter GAs and self-adaptive ESs shown in this study suggests the need for emphasizing further studies on self-adaptive GAs. PMID:11382356

  7. Adaptive kernel methods to simulate quantum phase space flow

    H.López

    2006-01-01

    Full Text Available A technique for simulating quantum dynamics in phase space is discussed. It makes use of ensembles of classical trajectories to approximate the distribution functions and their derivatives by implementing Adaptive Kernel Density Estimation. It is found to improve the accuracy and stability of the simulations compared to more conventional particle methods. Formulation of the method in higher dimensions is straightforward.

  8. Simulation and Rapid Prototyping of Adaptive Control Systems using the Adaptive Blockset for Simulink

    Ravn, Ole

    1998-01-01

    The paper describes the design considerations and implementational aspects of the Adaptive Blockset for Simulink which has been developed in a prototype implementation. The concept behind the Adaptive Blockset for Simulink is to bridge the gap between simulation and prototype controller...... implementation. This is done using the code generation capabilities of Real Time Workshop in combination with C s-function blocks for adaptive control in Simulink. In the paper the design of each group of blocks normally found in adaptive controllers is outlined. The block types are, identification, controller...... design, controller and state variable filter.The use of the Adaptive Blockset is demonstrated using a simple laboratory setup. Both the use of the blockset for simulation and for rapid prototyping of a real-time controller are shown....

  9. Adaptive LES Methodology for Turbulent Flow Simulations

    Oleg V. Vasilyev

    2008-06-12

    Although turbulent flows are common in the world around us, a solution to the fundamental equations that govern turbulence still eludes the scientific community. Turbulence has often been called one of the last unsolved problem in classical physics, yet it is clear that the need to accurately predict the effect of turbulent flows impacts virtually every field of science and engineering. As an example, a critical step in making modern computational tools useful in designing aircraft is to be able to accurately predict the lift, drag, and other aerodynamic characteristics in numerical simulations in a reasonable amount of time. Simulations that take months to years to complete are much less useful to the design cycle. Much work has been done toward this goal (Lee-Rausch et al. 2003, Jameson 2003) and as cost effective accurate tools for simulating turbulent flows evolve, we will all benefit from new scientific and engineering breakthroughs. The problem of simulating high Reynolds number (Re) turbulent flows of engineering and scientific interest would have been solved with the advent of Direct Numerical Simulation (DNS) techniques if unlimited computing power, memory, and time could be applied to each particular problem. Yet, given the current and near future computational resources that exist and a reasonable limit on the amount of time an engineer or scientist can wait for a result, the DNS technique will not be useful for more than 'unit' problems for the foreseeable future (Moin & Kim 1997, Jimenez & Moin 1991). The high computational cost for the DNS of three dimensional turbulent flows results from the fact that they have eddies of significant energy in a range of scales from the characteristic length scale of the flow all the way down to the Kolmogorov length scale. The actual cost of doing a three dimensional DNS scales as Re{sup 9/4} due to the large disparity in scales that need to be fully resolved. State-of-the-art DNS calculations of isotropic

  10. Adaptive image ray-tracing for astrophysical simulations

    Parkin, E. R.

    2010-01-01

    A technique is presented for producing synthetic images from numerical simulations whereby the image resolution is adapted around prominent features. In so doing, adaptive image ray-tracing (AIR) improves the efficiency of a calculation by focusing computational effort where it is needed most. The results of test calculations show that a factor of >~ 4 speed-up, and a commensurate reduction in the number of pixels required in the final image, can be achieved compared to an equivalent calculat...

  11. PASSATA - Object oriented numerical simulation software for adaptive optics

    Agapito, G; Esposito, S

    2016-01-01

    We present the last version of the PyrAmid Simulator Software for Adaptive opTics Arcetri (PASSATA), an IDL and CUDA based object oriented software developed in the Adaptive Optics group of the Arcetri observatory for Monte-Carlo end-to-end adaptive optics simulations. The original aim of this software was to evaluate the performance of a single conjugate adaptive optics system for ground based telescope with a pyramid wavefront sensor. After some years of development, the current version of PASSATA is able to simulate several adaptive optics systems: single conjugate, multi conjugate and ground layer, with Shack Hartmann and Pyramid wavefront sensors. It can simulate from 8m to 40m class telescopes, with diffraction limited and resolved sources at finite or infinite distance from the pupil. The main advantages of this software are the versatility given by the object oriented approach and the speed given by the CUDA implementation of the most computational demanding routines. We describe the software with its...

  12. A real-time simulation facility for astronomical adaptive optics

    Basden, Alastair

    2014-01-01

    In this paper we introduce the concept of real-time hardware-in-the-loop simulation for astronomical adaptive optics, and present the case for the requirement for such a facility. This real-time simulation, when linked with an adaptive optics real-time control system, provides an essential tool for the validation, verification and integration of the Extremely Large Telescope real-time control systems prior to commissioning at the telescope. We demonstrate that such a facility is crucial for the success of the future extremely large telescopes.

  13. Adaptive Simulated Annealing Based Protein Loop Modeling of Neurotoxins

    陈杰; 黄丽娜; 彭志红

    2003-01-01

    A loop modeling method, adaptive simulated annealing, for ab initio prediction of protein loop structures, as an optimization problem of searching the global minimum of a given energy function, is proposed. An interface-friendly toolbox-LoopModeller in Windows and Linux systems, VC++ and OpenGL environments is developed for analysis and visualization. Simulation results of three short-chain neurotoxins modeled by LoopModeller show that the method proposed is fast and efficient.

  14. SimulCAT: Windows Software for Simulating Computerized Adaptive Test Administration

    Han, Kyung T.

    2012-01-01

    Most, if not all, computerized adaptive testing (CAT) programs use simulation techniques to develop and evaluate CAT program administration and operations, but such simulation tools are rarely available to the public. Up to now, several software tools have been available to conduct CAT simulations for research purposes; however, these existing…

  15. Adaptive resolution simulation of an atomistic protein in MARTINI water

    Zavadlav, Julija; Melo, Manuel Nuno; Marrink, Siewert J.; Praprotnik, Matej

    2014-01-01

    We present an adaptive resolution simulation of protein G in multiscale water. We couple atomistic water around the protein with mesoscopic water, where four water molecules are represented with one coarse-grained bead, farther away. We circumvent the difficulties that arise from coupling to the coa

  16. Adaptive Sampling Algorithms for Probabilistic Risk Assessment of Nuclear Simulations

    Diego Mandelli; Dan Maljovec; Bei Wang; Valerio Pascucci; Peer-Timo Bremer

    2013-09-01

    Nuclear simulations are often computationally expensive, time-consuming, and high-dimensional with respect to the number of input parameters. Thus exploring the space of all possible simulation outcomes is infeasible using finite computing resources. During simulation-based probabilistic risk analysis, it is important to discover the relationship between a potentially large number of input parameters and the output of a simulation using as few simulation trials as possible. This is a typical context for performing adaptive sampling where a few observations are obtained from the simulation, a surrogate model is built to represent the simulation space, and new samples are selected based on the model constructed. The surrogate model is then updated based on the simulation results of the sampled points. In this way, we attempt to gain the most information possible with a small number of carefully selected sampled points, limiting the number of expensive trials needed to understand features of the simulation space. We analyze the specific use case of identifying the limit surface, i.e., the boundaries in the simulation space between system failure and system success. In this study, we explore several techniques for adaptively sampling the parameter space in order to reconstruct the limit surface. We focus on several adaptive sampling schemes. First, we seek to learn a global model of the entire simulation space using prediction models or neighborhood graphs and extract the limit surface as an iso-surface of the global model. Second, we estimate the limit surface by sampling in the neighborhood of the current estimate based on topological segmentations obtained locally. Our techniques draw inspirations from topological structure known as the Morse-Smale complex. We highlight the advantages and disadvantages of using a global prediction model versus local topological view of the simulation space, comparing several different strategies for adaptive sampling in both

  17. Adaptive thinking & leadership simulation game training for special forces officers.

    Raybourn, Elaine Marie; Mendini, Kip (USA JFKSWCS DOTD, Ft. Bragg, NC); Heneghan, Jerry; Deagle, Edwin (USA JFKSWCS DOTD, Ft. Bragg, NC)

    2005-07-01

    Complex problem solving approaches and novel strategies employed by the military at the squad, team, and commander level are often best learned experimentally. Since live action exercises can be costly, advances in simulation game training technology offer exciting ways to enhance current training. Computer games provide an environment for active, critical learning. Games open up possibilities for simultaneous learning on multiple levels; players may learn from contextual information embedded in the dynamics of the game, the organic process generated by the game, and through the risks, benefits, costs, outcomes, and rewards of alternative strategies that result from decision making. In the present paper we discuss a multiplayer computer game simulation created for the Adaptive Thinking & Leadership (ATL) Program to train Special Forces Team Leaders. The ATL training simulation consists of a scripted single-player and an immersive multiplayer environment for classroom use which leverages immersive computer game technology. We define adaptive thinking as consisting of competencies such as negotiation and consensus building skills, the ability to communicate effectively, analyze ambiguous situations, be self-aware, think innovatively, and critically use effective problem solving skills. Each of these competencies is an essential element of leader development training for the U.S. Army Special Forces. The ATL simulation is used to augment experiential learning in the curriculum for the U.S. Army JFK Special Warfare Center & School (SWCS) course in Adaptive Thinking & Leadership. The school is incorporating the ATL simulation game into two additional training pipelines (PSYOPS and Civil Affairs Qualification Courses) that are also concerned with developing cultural awareness, interpersonal communication adaptability, and rapport-building skills. In the present paper, we discuss the design, development, and deployment of the training simulation, and emphasize how the

  18. Adaptive expertise in work life:implications for collaboration and shared expertise

    Palosaari-Aubry, P. (Päivi)

    2014-01-01

    This study aims at drawing a picture of adaptive expertise in work life, more precisely in the context of collaboration and shared expertise. The need for my study stems from the complex nature of today’s work life, which is under constant change. Thus, mere domain-specific expertise and routine expertise are not sufficient. There is a need for adaptive experts who are flexible, able to adapt to uncertain situations (Bransford, 2004; Hatano & Inagaki, 1986), successful learners and able to de...

  19. A First Life with Computerized Business Simulations

    Thavikulwat, Precha

    2011-01-01

    The author discusses the theoretical lens, origins, and environment of his work on computerized business simulations. Key ideas that inform his work include the two dimensions (control and interaction) of computerized simulation, the two ways of representing a natural process (phenotypical and genotypical) in a simulation, which he defines as a…

  20. Adaptations to polar life in mammals and birds.

    Blix, Arnoldus Schytte

    2016-04-15

    This Review presents a broad overview of adaptations of truly Arctic and Antarctic mammals and birds to the challenges of polar life. The polar environment may be characterized by grisly cold, scarcity of food and darkness in winter, and lush conditions and continuous light in summer. Resident animals cope with these changes by behavioural, physical and physiological means. These include responses aimed at reducing exposure, such as 'balling up', huddling and shelter building; seasonal changes in insulation by fur, plumage and blubber; and circulatory adjustments aimed at preservation of core temperature, to which end the periphery and extremities are cooled to increase insulation. Newborn altricial animals have profound tolerance to hypothermia, but depend on parental care for warmth, whereas precocial mammals are well insulated and respond to cold with non-shivering thermogenesis in brown adipose tissue, and precocial birds shiver to produce heat. Most polar animals prepare themselves for shortness of food during winter by the deposition of large amounts of fat in times of plenty during autumn. These deposits are governed by a sliding set-point for body fatness throughout winter so that they last until the sun reappears in spring. Polar animals are, like most others, primarily active during the light part of the day, but when the sun never sets in summer and darkness prevails during winter, high-latitude animals become intermittently active around the clock, allowing opportunistic feeding at all times. The importance of understanding the needs of the individuals of a species to understand the responses of populations in times of climate change is emphasized. PMID:27103673

  1. Improving the adaptability of simulated evolutionary swarm robots in dynamically changing environments.

    Yao Yao

    Full Text Available One of the important challenges in the field of evolutionary robotics is the development of systems that can adapt to a changing environment. However, the ability to adapt to unknown and fluctuating environments is not straightforward. Here, we explore the adaptive potential of simulated swarm robots that contain a genomic encoding of a bio-inspired gene regulatory network (GRN. An artificial genome is combined with a flexible agent-based system, representing the activated part of the regulatory network that transduces environmental cues into phenotypic behaviour. Using an artificial life simulation framework that mimics a dynamically changing environment, we show that separating the static from the conditionally active part of the network contributes to a better adaptive behaviour. Furthermore, in contrast with most hitherto developed ANN-based systems that need to re-optimize their complete controller network from scratch each time they are subjected to novel conditions, our system uses its genome to store GRNs whose performance was optimized under a particular environmental condition for a sufficiently long time. When subjected to a new environment, the previous condition-specific GRN might become inactivated, but remains present. This ability to store 'good behaviour' and to disconnect it from the novel rewiring that is essential under a new condition allows faster re-adaptation if any of the previously observed environmental conditions is reencountered. As we show here, applying these evolutionary-based principles leads to accelerated and improved adaptive evolution in a non-stable environment.

  2. The limits of the adaptation of life to extreme conditions (in connection with problems of exobiology)

    Aksenov, S. I.

    1973-01-01

    Accommodation is discussed as a universal evolutionary principle which essentially will apply to all life forms, regardless of chemical base (carbon, silicon, etc.). Life forms must either adapt to extreme conditions or perish, and for any life form an extremum factor is any significant deviation in environmental parameters. The possibility of life forms existing in specific extraterrestrial environments is discussed, and a conclusion is drawn which unequivocally states that through many forms of accommodation life is possible in many different environments.

  3. A Model for Capturing Team Adaptation in Simulated Emergencies

    Paltved, Charlotte; Musaeus, Peter

    2013-01-01

    Research on how teams adapt to unforeseen changes or non-routine events supports the idea that updating is somehow difficult to accomplish.6,7 Methods: Thirty emergency physicians and nurses participated in a Simulator Instructor Course at SkejSim Medical Simulation and Skills Training, Aarhus, Denmark in...... May-June 2012. The study was exempted from approval from the Danish National Committee of Health Research. The study has been reported to the Danish Data Protection Agency. All participants volunteered and written informed consent was obtained. Twenty nine simulation scenarios were recorded and...... changes, adjust priorities and implement adjusted strategies were more likely to perform successfully in environments with unforeseen changes, in other words adaptability is the generalization of trained knowledge and skills to new, more difficult and more complex tasks. An interpretative approach is...

  4. Disaster Rescue Simulation based on Complex Adaptive Theory

    Feng Jiang

    2013-05-01

    Full Text Available Disaster rescue is one of the key measures of disaster reduction. The rescue process is a complex process with the characteristics of large scale, complicate structure, non-linear. It is hard to describe and analyze them with traditional methods. Based on complex adaptive theory, this paper analyzes the complex adaptation of the rescue process from seven features: aggregation, nonlinearity, mobility, diversity, tagging, internal model and building block. With the support of Repast platform, an agent-based model including rescue agents and victim agents was proposed. Moreover, two simulations with different parameters are employed to examine the feasibility of the model. As a result, the proposed model has been shown that it is efficient in dealing with the disaster rescue simulation and can provide the reference for making decisions.

  5. UNFOLDING SIMULATIONS OF COLD- AND WARM-ADAPTED ELASTASES

    Laura Riccardi1, Papaleo Elena2 *

    2010-11-01

    Full Text Available The earth surface is dominated by low temperature environments, which have been successfully colonized by several extremophilic organisms. Enzymes isolated from psychrophilic organisms are able to catalyze reactions at low temperatures at which enzymes from mesophiles or thermophiles are fully compromised. The current scenario on enzyme cold-adaptation suggest that these enzymes are characterized by higher catalytic efficiently at low temperatures, enhanced structural flexibility and lower thermostability. In the present contribution, molecular dynamics simulations in explicit solvent have been carried out at different high temperatures in order to investigate the unfolding process of cold- and warm-adapted homologous enzymes. In particular, we focused our attention on cold-adapted elastases for which it was previously demonstrated that the psychrophilic enzyme presents higher localized flexibility in loops surrounding the catalytic site and the specificity pocket. The unfolding simulations show a slower unfolding process for the cold-adapted enzyme, but characterized by a greater loss of intramolecular interactions and α-helices than the mesophilic counterparts.

  6. Nonlinear Adaptive Robust Force Control of Hydraulic Load Simulator

    YAO Jianyong; JIAO Zongxia; YAO Bin; SHANG Yaoxing; DONG Wenbin

    2012-01-01

    This paper deals with the high performance force control of hydraulic load samulator.Many prevtous works for hydraultc force control are based on their linearization equations,but hydraulic inherent nonlinear properties and uncertainties make the conventional feedback proportional-integral-derivative control not yield to high-performance requirements.In this paper,a nonlinear system model is derived and linear parameterization is made for adaptive control.Then a discontinuous projection-based nonlinear adaptive robust force controller is developed for hydraulic load simulator.The proposed controller constructs an asymptotically stable adaptive controller and adaptation laws,which can compensate for the system nonlinearities and uncertain parameters.Meanwhile a well-designed robust controller is also developed to cope with the hydraulic system uncertain nonlinearities.The controller achieves a guaranteed transient performance and final tracking accuracy in the presence of both parametric uncertainties and uncertain nonlinearities; in the absence of uncertain nonlinearities,the scheme also achieves asymptotic tracking performance.Simulation and experiment comparative results are obtained to verify the high-performance nature of the proposed control strategy and the tracking accuracy is greatly improved.

  7. Improvement of flight simulator feeling using adaptive fuzzy backlash compensation

    Amara, Zied; Bordeneuve-Guibé, Joël

    2007-01-01

    In this paper we addressed the problem of improving the control of DC motors used for the specific application of a 3 degrees of freedom moving base flight simulator. Indeed the presence of backlash in DC motors gearboxes induces shocks and naturally limits the flight feeling. In this paper, dynamic inversion with Fuzzy Logic is used to design an adaptive backlash compensator. The classification property of fuzzy logic techniques makes them a natural candidate for the rejection of errors indu...

  8. Advanced Dynamically Adaptive Algorithms for Stochastic Simulations on Extreme Scales

    Xiu, Dongbin [Purdue Univ., West Lafayette, IN (United States)

    2016-06-21

    The focus of the project is the development of mathematical methods and high-performance com- putational tools for stochastic simulations, with a particular emphasis on computations on extreme scales. The core of the project revolves around the design of highly e cient and scalable numer- ical algorithms that can adaptively and accurately, in high dimensional spaces, resolve stochastic problems with limited smoothness, even containing discontinuities.

  9. Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine

    Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula’s material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element’s remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than

  10. Adaptive scapula bone remodeling computational simulation: Relevance to regenerative medicine

    Sharma, Gulshan B., E-mail: gbsharma@ucalgary.ca [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States); University of Calgary, Schulich School of Engineering, Department of Mechanical and Manufacturing Engineering, Calgary, Alberta T2N 1N4 (Canada); Robertson, Douglas D., E-mail: douglas.d.robertson@emory.edu [Emory University, Department of Radiology and Imaging Sciences, Spine and Orthopaedic Center, Atlanta, Georgia 30329 (United States); University of Pittsburgh, Swanson School of Engineering, Department of Bioengineering, Pittsburgh, Pennsylvania 15213 (United States)

    2013-07-01

    Shoulder arthroplasty success has been attributed to many factors including, bone quality, soft tissue balancing, surgeon experience, and implant design. Improved long-term success is primarily limited by glenoid implant loosening. Prosthesis design examines materials and shape and determines whether the design should withstand a lifetime of use. Finite element (FE) analyses have been extensively used to study stresses and strains produced in implants and bone. However, these static analyses only measure a moment in time and not the adaptive response to the altered environment produced by the therapeutic intervention. Computational analyses that integrate remodeling rules predict how bone will respond over time. Recent work has shown that subject-specific two- and three dimensional adaptive bone remodeling models are feasible and valid. Feasibility and validation were achieved computationally, simulating bone remodeling using an intact human scapula, initially resetting the scapular bone material properties to be uniform, numerically simulating sequential loading, and comparing the bone remodeling simulation results to the actual scapula’s material properties. Three-dimensional scapula FE bone model was created using volumetric computed tomography images. Muscle and joint load and boundary conditions were applied based on values reported in the literature. Internal bone remodeling was based on element strain-energy density. Initially, all bone elements were assigned a homogeneous density. All loads were applied for 10 iterations. After every iteration, each bone element’s remodeling stimulus was compared to its corresponding reference stimulus and its material properties modified. The simulation achieved convergence. At the end of the simulation the predicted and actual specimen bone apparent density were plotted and compared. Location of high and low predicted bone density was comparable to the actual specimen. High predicted bone density was greater than

  11. Adaptive resolution simulation of an atomistic protein in MARTINI water

    We present an adaptive resolution simulation of protein G in multiscale water. We couple atomistic water around the protein with mesoscopic water, where four water molecules are represented with one coarse-grained bead, farther away. We circumvent the difficulties that arise from coupling to the coarse-grained model via a 4-to-1 molecule coarse-grain mapping by using bundled water models, i.e., we restrict the relative movement of water molecules that are mapped to the same coarse-grained bead employing harmonic springs. The water molecules change their resolution from four molecules to one coarse-grained particle and vice versa adaptively on-the-fly. Having performed 15 ns long molecular dynamics simulations, we observe within our error bars no differences between structural (e.g., root-mean-squared deviation and fluctuations of backbone atoms, radius of gyration, the stability of native contacts and secondary structure, and the solvent accessible surface area) and dynamical properties of the protein in the adaptive resolution approach compared to the fully atomistically solvated model. Our multiscale model is compatible with the widely used MARTINI force field and will therefore significantly enhance the scope of biomolecular simulations

  12. The yak genome and adaptation to life at high altitude

    Qiu, Qiang; Zhang, Guojie; Ma, Tao; Qian, Wubin; Wang, Junyi; Ye, Zhiqiang; Cao, Changchang; Hu, Quanjun; Kim, Jaebum; Larkin, Denis M; Auvil, Loretta; Capitanu, Boris; Ma, Jian; Lewin, Harris A; Qian, Xiaoju; Lang, Yongshan; Zhou, Ran; Wang, Lizhong; Wang, Kun; Xia, Jinquan; Liao, Shengguang; Pan, Shengkai; Lu, Xu; Hou, Haolong; Wang, Yan; Zang, Xuetao; Yin, Ye; Ma, Hui; Zhang, Jian; Wang, Zhaofeng; Zhang, Yingmei; Zhang, Dawei; Yonezawa, Takahiro; Hasegawa, Masami; Zhong, Yang; Liu, Wenbin; Zhang, Yan; Huang, Zhiyong; Zhang, Shengxiang; Long, Ruijun; Yang, Huanming; Lenstra, Johannes A; Cooper, David N; Wu, Yi; Wang, Jun; Shi, Peng; Wang, Jian; Liu, Jianquan

    2012-01-01

    Domestic yaks (Bos grunniens) provide meat and other necessities for Tibetans living at high altitude on the Qinghai-Tibetan Plateau and in adjacent regions. Comparison between yak and the closely related low-altitude cattle (Bos taurus) is informative in studying animal adaptation to high altitude...... important implications for understanding adaptation to high altitude in other animal species and for hypoxia-related diseases in humans....

  13. Simulating advanced life support systems to test integrated control approaches

    Kortenkamp, D.; Bell, S.

    Simulations allow for testing of life support control approaches before hardware is designed and built. Simulations also allow for the safe exploration of alternative control strategies during life support operation. As such, they are an important component of any life support research program and testbed. This paper describes a specific advanced life support simulation being created at NASA Johnson Space Center. It is a discrete-event simulation that is dynamic and stochastic. It simulates all major components of an advanced life support system, including crew (with variable ages, weights and genders), biomass production (with scalable plantings of ten different crops), water recovery, air revitalization, food processing, solid waste recycling and energy production. Each component is modeled as a producer of certain resources and a consumer of certain resources. The control system must monitor (via sensors) and control (via actuators) the flow of resources throughout the system to provide life support functionality. The simulation is written in an object-oriented paradigm that makes it portable, extensible and reconfigurable.

  14. An Evolutionary Agent-based simulation model for the industry life cycle

    Lehmann-Waffenschmidt, B. Cornelia

    2008-01-01

    In contrast to the usual approach taken in the literature, in which an Industry Life Cycle (ILC) is reproduced by aggregate functions, the model of this paper generates a self-organizing ILC. A general evolutionary agent-based simulation model is developed that can be adapted for specific branches of industry. The results enable conclusions to be drawn for competition policy with regard to the workability of competition in the various phases of the ILC.

  15. Spaceflight Sensorimotor Analogs: Simulating Acute and Adaptive Effects

    Taylor, Laura C.; Harm, Deborah L.; Kozlovskaya, Inessa; Reschke, Millard F.; Wood, Scott J.

    2009-01-01

    Adaptive changes in sensorimotor function during spaceflight are reflected by spatial disorientation, motion sickness, gaze destabilization and decrements in balance, locomotion and eye-hand coordination that occur during and following transitions between different gravitational states. The purpose of this study was to conduct a meta-synthesis of data from spaceflight analogs to evaluate their effectiveness in simulating adaptive changes in sensorimotor function. METHODS. The analogs under review were categorized as either acute analogs used to simulate performance decrements accompanied with transient changes, or adaptive analogs used to drive sensorimotor learning to altered sensory feedback. The effectiveness of each analog was evaluated in terms of mechanisms of action, magnitude and time course of observed deficits compared to spaceflight data, and the effects of amplitude and exposure duration. RESULTS. Parabolic flight has been used extensively to examine effects of acute variation in gravitational loads, ranging from hypergravity to microgravity. More recently, galvanic vestibular stimulation has been used to elicit acute postural, locomotor and gaze dysfunction by disrupting vestibular afferents. Patient populations, e.g., with bilateral vestibular loss or cerebellar dysfunction, have been proposed to model acute sensorimotor dysfunction. Early research sponsored by NASA involved living onboard rotating rooms, which appeared to approximate the time course of adaptation and post-exposure recovery observed in astronauts following spaceflight. Exposure to different bed-rest paradigms (6 deg head down, dry immersion) result in similar motor deficits to that observed following spaceflight. Shorter adaptive analogs have incorporated virtual reality environments, visual distortion paradigms, exposure to conflicting tilt-translation cues, and exposure to 3Gx centrifugation. As with spaceflight, there is considerable variability in responses to most of the analogs

  16. An adaptive nonlinear solution scheme for reservoir simulation

    Lett, G.S. [Scientific Software - Intercomp, Inc., Denver, CO (United States)

    1996-12-31

    Numerical reservoir simulation involves solving large, nonlinear systems of PDE with strongly discontinuous coefficients. Because of the large demands on computer memory and CPU, most users must perform simulations on very coarse grids. The average properties of the fluids and rocks must be estimated on these grids. These coarse grid {open_quotes}effective{close_quotes} properties are costly to determine, and risky to use, since their optimal values depend on the fluid flow being simulated. Thus, they must be found by trial-and-error techniques, and the more coarse the grid, the poorer the results. This paper describes a numerical reservoir simulator which accepts fine scale properties and automatically generates multiple levels of coarse grid rock and fluid properties. The fine grid properties and the coarse grid simulation results are used to estimate discretization errors with multilevel error expansions. These expansions are local, and identify areas requiring local grid refinement. These refinements are added adoptively by the simulator, and the resulting composite grid equations are solved by a nonlinear Fast Adaptive Composite (FAC) Grid method, with a damped Newton algorithm being used on each local grid. The nonsymmetric linear system of equations resulting from Newton`s method are in turn solved by a preconditioned Conjugate Gradients-like algorithm. The scheme is demonstrated by performing fine and coarse grid simulations of several multiphase reservoirs from around the world.

  17. Virtual Retail Simulations in Second Life

    Drake-Bridges, Erin; Strelzoff, Andrew; Sulbaran, Tulio

    2011-01-01

    This paper explores the use of simulations in virtual reality to teach students the fundamental processes behind retailing and product development. The project described involved one class of students who developed their own clothing lines of "virtual merchandise." A second class of students then "purchased" the wholesale virtual goods and…

  18. Life Strategies and Adaptations in Bryophytes from the Near and Middle East

    KÜRSCHNER, Harald

    2004-01-01

    A review article on life strategies and ecomorphological adaptations (xerothalloid and xeropottioid life syndromes) of bryophytes is given, based on the hitherto known and analysed terrestrial, saxicolous and epiphytic communities of the Near and Middle East. The examples given impressively demonstrate common adaptive trends that arise convergently but independently in unrelated taxa when they evolve under similar habitat conditions. These functional types are important for the establishment,...

  19. Hydrodynamical Adaptive Mesh Refinement Simulations of Disk Galaxies

    Gibson, Brad K; Sanchez-Blazquez, Patricia; Teyssier, Romain; House, Elisa L; Brook, Chris B; Kawata, Daisuke

    2008-01-01

    To date, fully cosmological hydrodynamic disk simulations to redshift zero have only been undertaken with particle-based codes, such as GADGET, Gasoline, or GCD+. In light of the (supposed) limitations of traditional implementations of smoothed particle hydrodynamics (SPH), or at the very least, their respective idiosyncrasies, it is important to explore complementary approaches to the SPH paradigm to galaxy formation. We present the first high-resolution cosmological disk simulations to redshift zero using an adaptive mesh refinement (AMR)-based hydrodynamical code, in this case, RAMSES. We analyse the temporal and spatial evolution of the simulated stellar disks' vertical heating, velocity ellipsoids, stellar populations, vertical and radial abundance gradients (gas and stars), assembly/infall histories, warps/lopsideness, disk edges/truncations (gas and stars), ISM physics implementations, and compare and contrast these properties with our sample of cosmological SPH disks, generated with GCD+. These prelim...

  20. Family Socioeconomic Status and Student Adaptation to School Life: Looking beyond Grades

    Carvalho, Renato G.; Novo, Rosa F.

    2012-01-01

    Introduction: In this quantitative, cross-sectional study we analyse the relationship between family socioeconomic status (SES) and students' adaptation to school life, as expressed through several indicators of achievement, integration (adaptation to transitions, behaviour problems, risk behaviours, interpersonal difficulties, participation in…

  1. Composition and adaptation in the life of Robert Schumann.

    Graves, John S

    2005-01-01

    The composer Robert Schumann, who suffered from bipolar disorder, utilized his impressive musical and literary talents in attempts to adapt to multiple developmental traumas, separations, and losses as well as to the ongoing ravages of his mood disorder. By analyzing several of his Lieder, the author formulates and describes several defense mechanisms involved in these adaptations. These include identification with the lost object, the use of transitional objects and phenomena, sublimation, denial, minimization, idealization, playfulness, and the employment of healthy obsessive traits. Schumann utilized these adaptive defenses successfully for a brief period, thus coping with a difficult separation from his fiancée, Clara. Ultimately, however, he was unable to experience mature mourning regarding the deaths of several family members. The author, drawing on his extensive experience with treating bipolar individuals in outpatient settings, discusses some of the difficulties that many bipolar patients like Schumann have with mourning, including early developmental vulnerabilities to separation and loss, the disorganizing effects of bipolar mood episodes on cognition and self-coherence, the need to camouflage affects reminiscent of bipolar mood episodes, and experiencing these affects and mood episodes as traumatic reoccurrences. By studying the biographies of creative individuals such as Schumann, clinicians can expand their appreciation of their patients' adaptive capacities and thus assist them in restoring a sense of hope and vitality in their lives. PMID:16370792

  2. SIMULATION AND PERFORMANCE ANALYASIS OF ADAPTIVE FILTER IN NOISE CANCELLATION

    RAJ KUMAR THENUA,

    2010-09-01

    Full Text Available Noise problems in the environment have gained attention due to the tremendous growth of technology that has led to noisy engines, heavy machinery, high speed wind buffeting and other noise sources. The problem of controlling the noise level has become the focus of a tremendous amount of research over the years. In last few years various adaptive algorithms are developed for noise cancellation. In this paper we present an implementation of LMS (Least Mean Square, NLMS (Normalized Least Mean Square and RLS (Recursive Least Square algorithms on MATLAB platform with the intention to compare their performance in noise cancellation. We simulate the adaptive filter in MATLAB with a noisy tone signal and white noise signal and analyze the performance of algorithms in terms of MSE (Mean Squared Error, percentage noise removal, computational complexity and stability. The obtained results shows that RLS has the best performance but at thecost of large computational complexity and memory requirement.

  3. Strategies in edge plasma simulation using adaptive dynamic nodalization techniques

    A wide span of steady-state and transient edge plasma processes simulation problems require accurate discretization techniques and can then be treated with Finite Element (FE) and Finite Volume (FV) methods. The software used here to meet these meshing requirements is a 2D finite element grid generator. It allows to produce adaptive unstructured grids taking into consideration the flux surface characteristics. To comply with the common mesh handling features of FE/FV packages, some options have been added to the basic generation tool. These enhancements include quadrilateral meshes without non-regular transition elements obtained by substituting them by transition constructions consisting of regular quadrilateral elements. Furthermore triangular grids can be created with one edge parallel to the magnetic field and modified by the basic adaptation/realignment techniques. Enhanced code operation properties and processing capabilities are expected. (author)

  4. Decentralized adaptive control of manipulators - Theory, simulation, and experimentation

    Seraji, Homayoun

    1989-01-01

    The author presents a simple decentralized adaptive-control scheme for multijoint robot manipulators based on the independent joint control concept. The control objective is to achieve accurate tracking of desired joint trajectories. The proposed control scheme does not use the complex manipulator dynamic model, and each joint is controlled simply by a PID (proportional-integral-derivative) feedback controller and a position-velocity-acceleration feedforward controller, both with adjustable gains. Simulation results are given for a two-link direct-drive manipulator under adaptive independent joint control. The results illustrate trajectory tracking under coupled dynamics and varying payload. The proposed scheme is implemented on a MicroVAX II computer for motion control of the three major joints of a PUMA 560 arm. Experimental results are presented to demonstrate that trajectory tracking is achieved despite coupled nonlinear joint dynamics.

  5. A parallel adaptive finite difference algorithm for petroleum reservoir simulation

    Hoang, Hai Minh

    2005-07-01

    Adaptive finite differential for problems arising in simulation of flow in porous medium applications are considered. Such methods have been proven useful for overcoming limitations of computational resources and improving the resolution of the numerical solutions to a wide range of problems. By local refinement of the computational mesh where it is needed to improve the accuracy of solutions, yields better solution resolution representing more efficient use of computational resources than is possible with traditional fixed-grid approaches. In this thesis, we propose a parallel adaptive cell-centered finite difference (PAFD) method for black-oil reservoir simulation models. This is an extension of the adaptive mesh refinement (AMR) methodology first developed by Berger and Oliger (1984) for the hyperbolic problem. Our algorithm is fully adaptive in time and space through the use of subcycling, in which finer grids are advanced at smaller time steps than the coarser ones. When coarse and fine grids reach the same advanced time level, they are synchronized to ensure that the global solution is conservative and satisfy the divergence constraint across all levels of refinement. The material in this thesis is subdivided in to three overall parts. First we explain the methodology and intricacies of AFD scheme. Then we extend a finite differential cell-centered approximation discretization to a multilevel hierarchy of refined grids, and finally we are employing the algorithm on parallel computer. The results in this work show that the approach presented is robust, and stable, thus demonstrating the increased solution accuracy due to local refinement and reduced computing resource consumption. (Author)

  6. Adaptive hybrid simulations for multiscale stochastic reaction networks

    The probability distribution describing the state of a Stochastic Reaction Network (SRN) evolves according to the Chemical Master Equation (CME). It is common to estimate its solution using Monte Carlo methods such as the Stochastic Simulation Algorithm (SSA). In many cases, these simulations can take an impractical amount of computational time. Therefore, many methods have been developed that approximate sample paths of the underlying stochastic process and estimate the solution of the CME. A prominent class of these methods include hybrid methods that partition the set of species and the set of reactions into discrete and continuous subsets. Such a partition separates the dynamics into a discrete and a continuous part. Simulating such a stochastic process can be computationally much easier than simulating the exact discrete stochastic process with SSA. Moreover, the quasi-stationary assumption to approximate the dynamics of fast subnetworks can be applied for certain classes of networks. However, as the dynamics of a SRN evolves, these partitions may have to be adapted during the simulation. We develop a hybrid method that approximates the solution of a CME by automatically partitioning the reactions and species sets into discrete and continuous components and applying the quasi-stationary assumption on identifiable fast subnetworks. Our method does not require any user intervention and it adapts to exploit the changing timescale separation between reactions and/or changing magnitudes of copy-numbers of constituent species. We demonstrate the efficiency of the proposed method by considering examples from systems biology and showing that very good approximations to the exact probability distributions can be achieved in significantly less computational time. This is especially the case for systems with oscillatory dynamics, where the system dynamics change considerably throughout the time-period of interest

  7. Direct numerical simulation of bubbles with parallelized adaptive mesh refinement

    The study of two-phase Thermal-Hydraulics is a major topic for Nuclear Engineering for both security and efficiency of nuclear facilities. In addition to experiments, numerical modeling helps to knowing precisely where bubbles appear and how they behave, in the core as well as in the steam generators. This work presents the finest scale of representation of two-phase flows, Direct Numerical Simulation of bubbles. We use the 'Di-phasic Low Mach Number' equation model. It is particularly adapted to low-Mach number flows, that is to say flows which velocity is much slower than the speed of sound; this is very typical of nuclear thermal-hydraulics conditions. Because we study bubbles, we capture the front between vapor and liquid phases thanks to a downward flux limiting numerical scheme. The specific discrete analysis technique this work introduces is well-balanced parallel Adaptive Mesh Refinement (AMR). With AMR, we refined the coarse grid on a batch of patches in order to locally increase precision in areas which matter more, and capture fine changes in the front location and its topology. We show that patch-based AMR is very adapted for parallel computing. We use a variety of physical examples: forced advection, heat transfer, phase changes represented by a Stefan model, as well as the combination of all those models. We will present the results of those numerical simulations, as well as the speed up compared to equivalent non-AMR simulation and to serial computation of the same problems. This document is made up of an abstract and the slides of the presentation. (author)

  8. Adaptive mesh refinement and adjoint methods in geophysics simulations

    Burstedde, Carsten

    2013-04-01

    It is an ongoing challenge to increase the resolution that can be achieved by numerical geophysics simulations. This applies to considering sub-kilometer mesh spacings in global-scale mantle convection simulations as well as to using frequencies up to 1 Hz in seismic wave propagation simulations. One central issue is the numerical cost, since for three-dimensional space discretizations, possibly combined with time stepping schemes, a doubling of resolution can lead to an increase in storage requirements and run time by factors between 8 and 16. A related challenge lies in the fact that an increase in resolution also increases the dimensionality of the model space that is needed to fully parametrize the physical properties of the simulated object (a.k.a. earth). Systems that exhibit a multiscale structure in space are candidates for employing adaptive mesh refinement, which varies the resolution locally. An example that we found well suited is the mantle, where plate boundaries and fault zones require a resolution on the km scale, while deeper area can be treated with 50 or 100 km mesh spacings. This approach effectively reduces the number of computational variables by several orders of magnitude. While in this case it is possible to derive the local adaptation pattern from known physical parameters, it is often unclear what are the most suitable criteria for adaptation. We will present the goal-oriented error estimation procedure, where such criteria are derived from an objective functional that represents the observables to be computed most accurately. Even though this approach is well studied, it is rarely used in the geophysics community. A related strategy to make finer resolution manageable is to design methods that automate the inference of model parameters. Tweaking more than a handful of numbers and judging the quality of the simulation by adhoc comparisons to known facts and observations is a tedious task and fundamentally limited by the turnaround times

  9. Early life stages contribute strongly to local adaptation in Arabidopsis thaliana.

    Postma, Froukje M; Ågren, Jon

    2016-07-01

    The magnitude and genetic basis of local adaptation is of fundamental interest in evolutionary biology. However, field experiments usually do not consider early life stages, and therefore may underestimate local adaptation and miss genetically based tradeoffs. We examined the contribution of differences in seedling establishment to adaptive differentiation and the genetic architecture of local adaptation using recombinant inbred lines (RIL) derived from a cross between two locally adapted populations (Italy and Sweden) of the annual plant Arabidopsis thaliana We planted freshly matured, dormant seeds (>180 000) representing >200 RILs at the native field sites of the parental genotypes, estimated the strength of selection during different life stages, mapped quantitative trait loci (QTL) for fitness and its components, and quantified selection on seed dormancy. We found that selection during the seedling establishment phase contributed strongly to the fitness advantage of the local genotype at both sites. With one exception, local alleles of the eight distinct establishment QTL were favored. The major QTL for establishment and total fitness showed evidence of a fitness tradeoff and was located in the same region as the major seed dormancy QTL and the dormancy gene DELAY OF GERMINATION 1 (DOG1). RIL seed dormancy could explain variation in seedling establishment and fitness across the life cycle. Our results demonstrate that genetically based differences in traits affecting performance during early life stages can contribute strongly to adaptive differentiation and genetic tradeoffs, and should be considered for a full understanding of the ecology and genetics of local adaptation. PMID:27330113

  10. Research on Relationship Model of Social Adaptation,Social Support and Life Satisfaction of Tibetan Hearing Loss Children

    SHEN Ren-hong

    2014-01-01

    The paper takes 230 Tibetan hearing loss children sample to research on relationship model of social adaptation, social support and life satisfaction of Tibetan hearing loss children by hearing disabled children’s social adaptive behavior, social support assessment scale and life satisfaction rating scale. Results present that there be significant positive relationship between social support and social adaptation, between social adaptation and life satisfaction. Further more, the social suppo...

  11. Adaptive and predictive control of a simulated robot arm.

    Tolu, Silvia; Vanegas, Mauricio; Garrido, Jesús A; Luque, Niceto R; Ros, Eduardo

    2013-06-01

    In this work, a basic cerebellar neural layer and a machine learning engine are embedded in a recurrent loop which avoids dealing with the motor error or distal error problem. The presented approach learns the motor control based on available sensor error estimates (position, velocity, and acceleration) without explicitly knowing the motor errors. The paper focuses on how to decompose the input into different components in order to facilitate the learning process using an automatic incremental learning model (locally weighted projection regression (LWPR) algorithm). LWPR incrementally learns the forward model of the robot arm and provides the cerebellar module with optimal pre-processed signals. We present a recurrent adaptive control architecture in which an adaptive feedback (AF) controller guarantees a precise, compliant, and stable control during the manipulation of objects. Therefore, this approach efficiently integrates a bio-inspired module (cerebellar circuitry) with a machine learning component (LWPR). The cerebellar-LWPR synergy makes the robot adaptable to changing conditions. We evaluate how this scheme scales for robot-arms of a high number of degrees of freedom (DOFs) using a simulated model of a robot arm of the new generation of light weight robots (LWRs). PMID:23627657

  12. Early life experience: neuroendocrine adaptations to maternal absence

    Enthoven, Leo

    2007-01-01

    An adverse early life event is considered a risk factor for stress-related psychiatric disorders in genetically predisposed individuals, probably because of its lasting effect on susceptibility to stress. The objective of this thesis research was to examine in the mouse CD1 strain the immediate and permanent effects of an adverse early experience on the neuroendocrine stress system. For this purpose the hypothalamic-pituitary-adrenal (HPA) axis was examined of mouse pups that were refrained f...

  13. Structural considerations for a software life cycle dynamic simulation model

    Tausworthe, R. C.; Mckenzie, M.; Lin, C. Y.

    1983-01-01

    This paper presents the results of a preliminary study into the prospects for simulating the software implementation and maintenance life cycle process, with the aim of producing a computerized tool for use by management and software engineering personnel in project planning, tradeoff studies involving product, environmental, situational, and technological factors, and training. The approach taken is the modular application of a 'flow of resource' concept to the systems dynamics simulation modeling technique. The software life cycle process is represented as a number of stochastic, time-varying, interacting work tasks that each achieves one of the project milestones. Each task is characterized by the item produced, the personnel applied, and the budgetary profile.

  14. Adaptive resolution simulation of polarizable supramolecular coarse-grained water models

    Zavadlav, Julija; Melo, Manuel N.; Marrink, Siewert J.; Praprotnik, Matej

    2015-01-01

    Multiscale simulations methods, such as adaptive resolution scheme, are becoming increasingly popular due to their significant computational advantages with respect to conventional atomistic simulations. For these kind of simulations, it is essential to develop accurate multiscale water models that

  15. Thermal Modeling and Feedback Requirements for LIFE Neutronic Simulations

    Seifried, J E

    2009-07-15

    An initial study is performed to determine how temperature considerations affect LIFE neutronic simulations. Among other figures of merit, the isotopic mass accumulation, thermal power, tritium breeding, and criticality are analyzed. Possible fidelities of thermal modeling and degrees of coupling are explored. Lessons learned from switching and modifying nuclear datasets is communicated.

  16. Mandela’s Meanings: a Translated and Adapted Life

    Carli Coetzee

    2014-11-01

    Full Text Available This paper reflects on the seeming ubiquity of representations of Nelson Mandela, and contrasts this with the years of silence and facelessness that have entered the mythological sphere - the 18 years he spent on Robben Island. The period when Mandela (through text or image circulated the least has now in fact become the centrepiece of the narrative of his life. In this paper, I reconstitute some of the literary and photographic fragments of that era, one for which the biographical record is strikingly consistent ad repetitive. One anecdote that has been retold by every biographer is that of Mandela performing the role of King Creon in a production of Antigone. Interpreters typically cast this small incident in mythical and allegorical terms. Through reconstituting the scattered references to the performance, I show that these interpretations typically exaggerate and misread the anecdote. Thus the Antigone performance provides us instead, I argue, with an instance of a retrospective reading that exceeds the event.

  17. Adapting a weather forecast model for greenhouse gas simulation

    Polavarapu, S. M.; Neish, M.; Tanguay, M.; Girard, C.; de Grandpré, J.; Gravel, S.; Semeniuk, K.; Chan, D.

    2015-12-01

    The ability to simulate greenhouse gases on the global domain is useful for providing boundary conditions for regional flux inversions, as well as for providing reference data for bias correction of satellite measurements. Given the existence of operational weather and environmental prediction models and assimilation systems at Environment Canada, it makes sense to use these tools for greenhouse gas simulations. In this work, we describe the adaptations needed to reasonably simulate CO2 with a weather forecast model. The main challenges were the implementation of a mass conserving advection scheme, and the careful implementation of a mixing ratio defined with respect to dry air. The transport of tracers through convection was also added, and the vertical mixing through the boundary layer was slightly modified. With all these changes, the model conserves CO2 mass well on the annual time scale, and the high resolution (0.9 degree grid spacing) permits a good description of synoptic scale transport. The use of a coupled meteorological/tracer transport model also permits an assessment of approximations needed in offline transport model approaches, such as the neglect of water vapour mass when computing a tracer mixing ratio with respect to dry air.

  18. Transcultural adaptation and validation of the "Adult Eosinophilic Esophagitis Quality of Life Questionnaire" into Spanish

    Lucendo, Alfredo J; Marta Sánchez-Cazalilla; Javier Molina-Infante; Isabel Pérez-Martínez; José M. Tenias; Jesús Barrio; Óscar Nantes; Constanza Ciriza de los Ríos; Antonia Perelló; Ángel Arias

    2014-01-01

    Background: The "Adult Eosinophilic Esophagitis Quality of Life (EoE-QoL-A) Questionnaire" was developed in English as a valid, reliable, and disease-specific health-related QoL measure. This research aims to adapt and validate this questionnaire for Spanish-speaking patients. Patients and methods: A multicenter, observational, prospective study was conducted at 8 Spanish hospitals. The cultural adaptation of the original EoE-QoL-A questionnaire was undertaken through a standardized 3-phase p...

  19. Adaptive model reduction for nonsmooth discrete element simulation

    Servin, Martin; Wang, Da

    2016-03-01

    A method for adaptive model order reduction for nonsmooth discrete element simulation is developed and analysed in numerical experiments. Regions of the granular media that collectively move as rigid bodies are substituted with rigid bodies of the corresponding shape and mass distribution. The method also support particles merging with articulated multibody systems. A model approximation error is defined and used to derive conditions for when and where to apply reduction and refinement back into particles and smaller rigid bodies. Three methods for refinement are proposed and tested: prediction from contact events, trial solutions computed in the background and using split sensors. The computational performance can be increased by 5-50 times for model reduction level between 70-95 %.

  20. Adaptive model reduction for nonsmooth discrete element simulation

    Servin, Martin

    2015-01-01

    A method for adaptive model order reduction for nonsmooth discrete element simulation is developed and analysed in numerical experiments. Regions of the granular media that collectively move as rigid bodies are substituted with rigid bodies of the corresponding shape and mass distribution. The method also support particles merging with articulated multibody systems. A model approximation error is defined used for deriving and conditions for when and where to apply model reduction and refinement back into particles and smaller rigid bodies. Three methods for refinement are proposed and tested: prediction from contact events, trial solutions computed in the background and using split sensors. The computational performance can be increased by 5 - 50 times for model reduction level between 70 - 95 %.

  1. FATIGUE LIFE EVALUATION OF SUSPENSION KNUCKLE USING MULTIBODY SIMULATION TECHNIQUE

    A.G.A. Rahman

    2012-12-01

    Full Text Available Suspension is part of automotive systems, providing both vehicle control and passenger comfort. The knuckle is an important part within the suspension system, constantly encountering the cyclic loads subjecting it to fatigue failure. This paper presents an evaluation of the fatigue characteristics of a knuckle using multibody simulation (MBS techniques. Load time history extracted from the MBS is used for stress analysis. An actual road profile of road bumps was used as the input to MBS. The stress fluctuations for fatigue simulations are considered with the road profile. The strain-life method is utilized to assess the fatigue life. The instantaneous stress distributions and maximum principal stress are used for fatigue life predictions. Mesh sensitivity analysis has been performed. The results show that the steering link in the knuckle is found to be the most susceptible region for fatigue failure. The number of times the knuckle can manage a road bump at 40 km/hr is determined to be approximately 371 times with a 50% certainty of survival. The proposed method of using the loading time history extracted from MBS simulation for fatigue life estimation is found to be very promising for the accurate evaluation of the performance of suspension system components.

  2. Unsteady CFD simulations of a pump in part load conditions using scale-adaptive simulation

    Lucius, A., E-mail: andreas.lucius@tu-clausthal.d [Institute of Applied Mechanics, Clausthal University of Technology, Adolph-Roemer Str. 2a, 38678 Clausthal-Zellerfeld (Germany); Brenner, G. [Institute of Applied Mechanics, Clausthal University of Technology, Adolph-Roemer Str. 2a, 38678 Clausthal-Zellerfeld (Germany)

    2010-12-15

    The scope of this work is to demonstrate the applicability of an eddy resolving turbulence model in a turbomachinery configuration. The model combines the Large Eddy Simulation (LES) and the Reynolds Averaged Navier Stokes (RANS) approach. The point of interest of the present investigation is the unsteady rotating stall phenomenon occurring at low part load conditions. Since RANS turbulence models often fail to predict separation correctly, a LES like model is expected to give superior results. In this investigation the scale-adaptive simulation (SAS) model is used. This model avoids the grid dependence appearing in the Detached Eddy Simulation (DES) modelling strategy. The simulations are validated with transient measurement data. The present results demonstrate, that both models are able to predict the major stall frequency at part load. Results are similar for URANS and SAS, with advantages in predicting minor stall frequencies for the turbulence resolving model.

  3. Determination of free energy profiles by repository based adaptive umbrella sampling: Bridging nonequilibrium and quasiequilibrium simulations

    Zheng, Han; Zhang, Yingkai

    2008-01-01

    We propose a new adaptive sampling approach to determine free energy profiles with molecular dynamics simulations, which is called as “repository based adaptive umbrella sampling” (RBAUS). Its main idea is that a sampling repository is continuously updated based on the latest simulation data, and the accumulated knowledge and sampling history are then employed to determine whether and how to update the biasing umbrella potential for subsequent simulations. In comparison with other adaptive me...

  4. The Impact of Different Portability Factors during the Life Cycle of an Educational Software Adaptation Project.

    Collis, Betty A.; De Diana, Italo

    1990-01-01

    Provides an example that illustrates the interrelationship of the factors that influence educational software portability. Nielsen's seven-level approach to human-computer interaction is used as the basis for a model for factors that influence portability, and five phases in the life cycle of a software product being adapted are considered. (10…

  5. Adaptive and Maladaptive Perfectionism as Mediators of Adult Attachment Styles and Depression, Hopelessness, and Life Satisfaction

    Gnilka, Philip B.; Ashby, Jeffrey S.; Noble, Christina M.

    2013-01-01

    This study examined the relationships between adaptive and maladaptive perfectionism, anxious and avoidant adult attachment styles, depression, hopelessness, and life satisfaction among a sample of 180 undergraduate students. Maladaptive perfectionism mediated the relationship between both forms of adult attachment and depression, hopelessness,…

  6. "Replaying Life's Tape": Simulations, metaphors, and historicity in Stephen Jay Gould's view of life.

    Sepkoski, David

    2016-08-01

    In a famous thought experiment, Stephen Jay Gould asked whether, if one could somehow rewind the history of life back to its initial starting point, the same results would obtain when the "tape" was run forward again. This hypothetical experiment is generally understood as a metaphor supporting Gould's philosophy of evolutionary contingency, which he developed and promoted from the late 1980s until his death in 2002. However, there was a very literal, non-metaphorical inspiration for Gould's thought experiment: since the early 1970s, Gould, along with a group of other paleontologists, was actively engaged in attempts to model and reconstruct the history of life using computer simulations and database analysis. These simulation projects not only demonstrate the impact that computers had on data analysis in paleontology, but also shed light on the close relationship between models and empirical data in data-oriented science. In a sense, I will argue, the models developed by paleontologists through simulation and quantitative analysis of the empirical fossil record in the 1970s and beyond were literal attempts to "replay life's tape" by reconstructing the history of life as data. PMID:26790344

  7. APPLICATION OF MULTIBODY SIMULATION FOR FATIGUE LIFE ESTIMATION

    M. Kamal

    2013-06-01

    Full Text Available In automobile design, the safety of passengers is of prime concern to the manufacturers. Suspension is one of the safety-related automotive systems which is responsible for maintaining traction between the road and tires, and offers a comfortable ride experience to the passengers by absorbing disturbances. One of the critical components of the suspension system is the knuckle, which constantly faces cyclic loads subjecting it to fatigue failure. This paper presents an evaluation of the fatigue characteristics of a knuckle using a gravel road profile acquired using a data acquisition system and standard SAE profiles for the suspension (SAESUS, bracket (SAEBRAKT and transmission (SAETRN. The gravel road profile was applied as the input to a multi body simulation (MBS, and the load history for various mounting points of the knuckle is extracted. Fatigue life is predicted using the strain-life method. The instantaneous stress distributions and maximum principal stress are used for fatigue life predictions. From the results, the strut connection is found to be the critical region for fatigue failure. The fatigue life from loading extracted from gravel road MBS agreed well with the life prediction when standard SAE profiles were used. This close agreement shows the effectiveness of the load extraction technique from MBS. This method can also be effectively used for more complex loading conditions that occur during real driving environments.

  8. Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China.

    Li, Xiao-Meng; She, Deng-Ying; Zhang, Da-Yong; Liao, Wan-Jin

    2015-03-01

    Local adaptation has been suggested to play an important role in range expansion, particularly among invasive species. However, the extent to which local adaptation affects the success of an invasive species and the factors that contribute to local adaptation are still unclear. This study aimed to investigate a case of population divergence that may have contributed to the local adaptation of invasive populations of Ambrosia artemisiifolia in China. Common garden experiments in seven populations indicated clinal variations along latitudinal gradients, with plants from higher latitudes exhibiting earlier flowering and smaller sizes at flowering. In reciprocal transplant experiments, plants of a northern Beijing origin produced more seeds at their home site than plants of a southern Wuhan origin, and the Wuhan-origin plants had grown taller at flowering than the Beijing-origin plants in Wuhan, which is believed to facilitate pollen dispersal. These results suggest that plants of Beijing origin may be locally adapted through female fitness and plants from Wuhan possibly locally adapted through male fitness. Selection and path analysis suggested that the phenological and growth traits of both populations have been influenced by natural selection and that flowering time has played an important role through its direct and indirect effects on the relative fitness of each individual. This study evidences the life history trait differentiation and local adaptation during range expansion of invasive A. artemisiifolia in China. PMID:25362583

  9. Software life cycle dynamic simulation model: The organizational performance submodel

    Tausworthe, Robert C.

    1985-01-01

    The submodel structure of a software life cycle dynamic simulation model is described. The software process is divided into seven phases, each with product, staff, and funding flows. The model is subdivided into an organizational response submodel, a management submodel, a management influence interface, and a model analyst interface. The concentration here is on the organizational response model, which simulates the performance characteristics of a software development subject to external and internal influences. These influences emanate from two sources: the model analyst interface, which configures the model to simulate the response of an implementing organization subject to its own internal influences, and the management submodel that exerts external dynamic control over the production process. A complete characterization is given of the organizational response submodel in the form of parameterized differential equations governing product, staffing, and funding levels. The parameter values and functions are allocated to the two interfaces.

  10. San Onofre Nuclear Generating station simulator life cycle

    This paper reports that the SONGS Unit 2/3 simulator was built by the Singer Link Company and delivered to Southern California Edison in July of 1983. Over the first seven years of its life, the fidelity and capabilities of the SONGS simulator have been substantially increased. The major modifications and upgrades which so far have been implemented into the SONGS 2/3 simulator include: Combustion Engineering's Critical Function Monitoring System upgrade and Qualified Safety Parameter Display System addition. Addition of Wide Range Gas Monitors, Steam Line and Containment High Range Radiation Monitor Cabinet. Gould 32/97-80 Computer and Shared Memory System addition to the 32/77-80 Master/Slave simulator computer configuration. Gould/Ce PACE system Plant Monitoring System upgrade. Singer-Link's Space Time Kinetic Reactor Core Model upgrade. Control Room design Review Board Modification upgrade. Installation of Singer-Link's Simulator Software Support System (S3) on SONGS 32/97-80 computer. Singer-Link-Miles' Reactor Coolant System and Steam Generator RETACT Model and Containment Multinode Model upgrade. Singer-Link-Miles' PC based Advanced Man Machine Interface Instructor Station upgrade. The major software tasks undertaken to provide these enhancements are reviewed in this paper. The authors' presentation focuses on the approach utilized by SCE to: achieve high fidelity and performance with the available computer processing power; and maximize simulation improvements and training features within the available outage times and allocated budget

  11. Adapting the SLIM diabetes prevention intervention to a Dutch real-life setting: joint decision making by science and practice

    2013-01-01

    Background Although many evidence-based diabetes prevention interventions exist, they are not easily applicable in real-life settings. Moreover, there is a lack of examples which describe the adaptation process of these interventions to practice. In this paper we present an example of such an adaptation. We adapted the SLIM (Study on Lifestyle intervention and Impaired glucose tolerance Maastricht) diabetes prevention intervention to a Dutch real-life setting, in a joint decision making proce...

  12. Adapting the SLIM diabetes prevention intervention to a Dutch real-life setting: joint decision making by science and practice

    Jansen, S.C.; Haveman-Nies, A.; Duijzer, G.; Beek, ter, J.; Hiddink, G.; Feskens, E.J.M.

    2013-01-01

    Background - Although many evidence-based diabetes prevention interventions exist, they are not easily applicable in real-life settings. Moreover, there is a lack of examples which describe the adaptation process of these interventions to practice. In this paper we present an example of such an adaptation. We adapted the SLIM (Study on Lifestyle intervention and Impaired glucose tolerance Maastricht) diabetes prevention intervention to a Dutch real-life setting, in a joint decision making pro...

  13. Simulating adaptive wood harvest in a changing climate

    Yousefpour, Rasoul; Nabel, Julia; Pongratz, Julia

    2016-04-01

    The world's forest experience substantial carbon exchange fluxes between land and atmosphere. Large carbon sinks occur in response to changes in environmental conditions (such as climate change and increased atmospheric CO2 concentrations), removing about one quarter of current anthropogenic CO2-emissions. Large sinks also occur due to regrowth of forest on areas of agricultural abandonment or forest management. Forest management, on the other hand, also leads to substantial amounts of carbon being eventually released to the atmosphere. Both sinks and sources attributable to forests are therefore dependent on the intensity of management. Forest management in turn depends on the availability of resources, which is influenced by environmental conditions and sustainability of management systems applied. Estimating future carbon fluxes therefore requires accounting for the interaction of environmental conditions, forest growth, and management. However, this interaction is not fully captured by current modeling approaches: Earth system models depict in detail interactions between climate, the carbon cycle, and vegetation growth, but use prescribed information on management. Resource needs and land management, however, are simulated by Integrated Assessment Models that typically only have coarse representations of the influence of environmental changes on vegetation growth and are typically based on the demand for wood driven by regional population growth and energy needs. Here we present a study that provides the link between environmental conditions, forest growth and management. We extend the land component JSBACH of the Max Planck Institute's Earth system model (MPI-ESM) to simulate potential wood harvest in response to altered growth conditions and thus as adaptive to changing climate and CO2 conditions. We apply the altered model to estimate potential wood harvest for future climates (representative concentration pathways, RCPs) for the management scenario of

  14. Mission simulation as an approach to develop requirements for automation in Advanced Life Support Systems

    Erickson, J. D.; Eckelkamp, R. E.; Barta, D. J.; Dragg, J.; Henninger, D. L. (Principal Investigator)

    1996-01-01

    This paper examines mission simulation as an approach to develop requirements for automation and robotics for Advanced Life Support Systems (ALSS). The focus is on requirements and applications for command and control, control and monitoring, situation assessment and response, diagnosis and recovery, adaptive planning and scheduling, and other automation applications in addition to mechanized equipment and robotics applications to reduce the excessive human labor requirements to operate and maintain an ALSS. Based on principles of systems engineering, an approach is proposed to assess requirements for automation and robotics using mission simulation tools. First, the story of a simulated mission is defined in terms of processes with attendant types of resources needed, including options for use of automation and robotic systems. Next, systems dynamics models are used in simulation to reveal the implications for selected resource allocation schemes in terms of resources required to complete operational tasks. The simulations not only help establish ALSS design criteria, but also may offer guidance to ALSS research efforts by identifying gaps in knowledge about procedures and/or biophysical processes. Simulations of a planned one-year mission with 4 crewmembers in a Human Rated Test Facility are presented as an approach to evaluation of mission feasibility and definition of automation and robotics requirements.

  15. Adaptations in the Treatment of Congenital Lymphedema Centered on the Quality of Life

    Jose Maria Pereira de Godoy; Ana Paula Sanchez; Daniel Zucchi Libanore; Maria de Fatima Guerreiro Godoy

    2014-01-01

    Case Description. This report describes the evolution, necessary adaptations, and complications in the treatment of a 9-year-old child with primary congenital lymphedema. Description of Intervention. The clinical treatment of lymphedema was started in the first year of the patient’s life and for five years she was only treated using the Godoy & Godoy technique of cervical stimulation. Three years ago the patient was prescribed a compression stocki...

  16. Turkish Adaptation, Validity and Reliability Study of the Beach Center Family Quality of Life Scale

    Meral, Bekir Fatih; Sakarya Üniversitesi, Eğitim Fakültesi, Özel Eğitim Bölümü; Cavkaytar, Atilla; Anadolu Üniversitesi, Eğitim Fakültesi, Özel Eğitim Bölümü

    2013-01-01

    The aim of this study is to adapt the Beach Center Family Quality of Life Scale to Turkish by examining its psychometric properties. Participants were 368 mothers of children with disabilities from 7 cities of Turkey. In this study firstly, the language equivalency between English and Turkish forms were tested. After that confirmatory factor analysis, criterion validity, the Cronbach’s alpha correlation coefficients, and split-half reliabilities, corrected item-total correlations and t-tests ...

  17. Control and adaptation strategies for invasive species with different life history

    Elofsson, Katarina; Gren, Ing-Marie

    2013-01-01

    The issue of timing and scope of policies to manage invasive species has achieved considerable attention in the economic literature. Whereas many earlier studies compare prevention and control for a single invading species, we focus instead on the optimal balance of adaptation and control when an invasive species competes for scarce resources with a resident species. In particular, we focus on the role that species’ life history, i.e. the degree of evolutionary specialization in survival or r...

  18. Bringing history to life: simulating landmark experiments in psychology.

    Boynton, David M; Smith, Laurence D

    2006-05-01

    The course in history of psychology can be challenging for students, many of whom enter it with little background in history and faced with unfamiliar names and concepts. The sheer volume of material can encourage passive memorization unless efforts are made to increase student involvement. As part of a trend toward experiential history, historians of science have begun to supplement their lectures with demonstrations of classic physics experiments as a way to bring the history of science to life. Here, the authors report on computer simulations of five landmark experiments from early experimental psychology in the areas of reaction time, span of attention, and apparent motion. The simulations are designed not only to permit hands-on replication of historically important results but also to reproduce the experimental procedures closely enough that students can gain a feel for the nature of early research and the psychological processes being studied. PMID:17152604

  19. Development of life sciences equipment for microgravity and hypergravity simulation

    Mulenburg, G. M.; Evans, J.; Vasques, M.; Gundo, D. P.; Griffith, J. B.; Harper, J.; Skundberg, T.

    1994-01-01

    The mission of the Life Science Division at the NASA Ames Research Center is to investigate the effects of gravity on living systems in the spectrum from cells to humans. The range of these investigations is from microgravity, as experienced in space, to Earth's gravity, and hypergravity. Exposure to microgravity causes many physiological changes in humans and other mammals including a headward shift of body fluids, atrophy of muscles - especially the large muscles of the legs - and changes in bone and mineral metabolism. The high cost and limited opportunity for research experiments in space create a need to perform ground based simulation experiments on Earth. Models that simulate microgravity are used to help identify and quantify these changes, to investigate the mechanisms causing these changes and, in some cases, to develop countermeasures.

  20. Cultural adaptation and validation of the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese1

    Domingues, Elaine Aparecida Rocha; Alexandre, Neusa Maria Costa; da Silva, José Vitor

    2016-01-01

    Objectives: to adapt the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese and to measure its psychometric properties: reliability and validity. Method: the cultural adaptation was undertaken following the stages of translation, synthesis of the translations, back translation, committee of specialists, pre-test and focus group. A total of 200 patients participated in the study. These were recruited in Primary Care Centers, Family Health Strategy Centers, in a philanthropic hospital and in a teaching hospital. Reliability was assessed through internal consistency and stability. Validity was ascertained through the correlation of the instrument's values with those of the domains of the Ferrans and Powers Quality of Life Index - Wound Version and with the quality of life score of the visual analog scale. Results: the instrument presented adequate internal consistency (Cronbach alpha =0.86) and high stability in the test and retest (0.93). The validity presented correlations of moderate and significant magnitude (-0.24 to -0.48, p<0.0001). Conclusion: the results indicated that the adapted version presented reliable and valid psychometric measurements for the population with chronic wounds in the Brazilian culture. PMID:27143539

  1. Cultural adaptation and validation of the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese

    Elaine Aparecida Rocha Domingues

    2016-01-01

    Full Text Available Objectives: to adapt the Freiburg Life Quality Assessment - Wound Module to Brazilian Portuguese and to measure its psychometric properties: reliability and validity. Method: the cultural adaptation was undertaken following the stages of translation, synthesis of the translations, back translation, committee of specialists, pre-test and focus group. A total of 200 patients participated in the study. These were recruited in Primary Care Centers, Family Health Strategy Centers, in a philanthropic hospital and in a teaching hospital. Reliability was assessed through internal consistency and stability. Validity was ascertained through the correlation of the instrument's values with those of the domains of the Ferrans and Powers Quality of Life Index - Wound Version and with the quality of life score of the visual analog scale. Results: the instrument presented adequate internal consistency (Cronbach alpha =0.86 and high stability in the test and retest (0.93. The validity presented correlations of moderate and significant magnitude (-0.24 to -0.48, p<0.0001. Conclusion: the results indicated that the adapted version presented reliable and valid psychometric measurements for the population with chronic wounds in the Brazilian culture.

  2. Creep life simulations of EB welded copper overpack

    The long term life predictions of copper overpack (sealed by EB welding in Finland) have previously been based on stress estimations that vary over a wide range, typically between 40-100 MPa. These values are usually not based on structural calculation including the EB-weld that increases the complexity of the stress state in the copper overpack. This report will attempt to pinpoint and simulate the stresses and strains developing in the copper overpack during its first decennia of repository service by advanced FEA simulations including the impact of the EB-weld. The main challenge of this work is the extrapolation of the creep strain response of OFP copper to the service relevant loads and temperatures. The uniaxial creep model is translated to a multiaxial constitutive equation form with adequate computational efficiency. The copper overpack strain and stress evolution has been simulated at up to 100 000 years at a conservative constant temperature of 80 deg C with 14 MPa of external pressure. The results indicate rapid creep relaxation in the initial stages after the load has been applied followed by limited creep strain accumulation thereafter. Local elastic-plastic and creep deformation is predicted at the EB weld root with a total strain of below 12 %. The predicted stresses after external loading and short term relaxation are moderate and the impact of weld residual stresses and the lower creep rupture properties of the EB seem not to be detrimental to the predicted long term creep response. The simulation results imply that the most crucial impact on the creep strain accumulation of the copper overpack is related to the OFP copper primary creep properties. The present study predicts sufficiently low creep strains for a 100 000 years canister life with the conservative assumption at a constant temperature of 80 deg C. However a sensitivity study on the impact of primary creep is strongly recommended due to contradicting analysis results from earlier FEA

  3. Visual Simulation of Microalgae Growth in Bioregenerative Life Support System

    Zhao, Ming

    Bioregenerative life support system is one of the key technologies for future human deep space exploration and long-term space missions. BLSS use biological system as its core unit in combination with other physical and chemical equipments, under the proper control and manipulation by crew to complete a specific task to support life. Food production, waste treatment, oxygen and water regeneration are all conducted by higher plants or microalgae in BLSS, which is the most import characteristic different from other kinds of life support systems. Microalgae is light autotrophic micro-organisms, light undoubtedly is the most import factor which limits its growth and reproduction. Increasing or decreasing the light intensity changes the growth rate of microalgae, and then regulates the concentration of oxygen and carbon dioxide in the system. In this paper, based on the mathematical model of microalgae which grew under the different light intensity, three-dimensional visualization model was built and realized through using 3ds max, Virtools and some other three dimensional software, in order to display its change and impacting on oxygen and carbon dioxide intuitively. We changed its model structure and parameters, such as establishing closed-loop control system, light intensity, temperature and Nutrient fluid’s velocity and so on, carried out computer virtual simulation, and observed dynamic change of system with the aim of providing visualization support for system research.

  4. Quantum simulations of nuclei and nuclear pasta with the multiresolution adaptive numerical environment for scientific simulations

    Sagert, I.; Fann, G. I.; Fattoyev, F. J.; Postnikov, S.; Horowitz, C. J.

    2016-05-01

    Background: Neutron star and supernova matter at densities just below the nuclear matter saturation density is expected to form a lattice of exotic shapes. These so-called nuclear pasta phases are caused by Coulomb frustration. Their elastic and transport properties are believed to play an important role for thermal and magnetic field evolution, rotation, and oscillation of neutron stars. Furthermore, they can impact neutrino opacities in core-collapse supernovae. Purpose: In this work, we present proof-of-principle three-dimensional (3D) Skyrme Hartree-Fock (SHF) simulations of nuclear pasta with the Multi-resolution ADaptive Numerical Environment for Scientific Simulations (MADNESS). Methods: We perform benchmark studies of 16O, 208Pb, and 238U nuclear ground states and calculate binding energies via 3D SHF simulations. Results are compared with experimentally measured binding energies as well as with theoretically predicted values from an established SHF code. The nuclear pasta simulation is initialized in the so-called waffle geometry as obtained by the Indiana University Molecular Dynamics (IUMD) code. The size of the unit cell is 24 fm with an average density of about ρ =0.05 fm-3 , proton fraction of Yp=0.3 , and temperature of T =0 MeV. Results: Our calculations reproduce the binding energies and shapes of light and heavy nuclei with different geometries. For the pasta simulation, we find that the final geometry is very similar to the initial waffle state. We compare calculations with and without spin-orbit forces. We find that while subtle differences are present, the pasta phase remains in the waffle geometry. Conclusions: Within the MADNESS framework, we can successfully perform calculations of inhomogeneous nuclear matter. By using pasta configurations from IUMD it is possible to explore different geometries and test the impact of self-consistent calculations on the latter.

  5. Use of sensitivity-information for the adaptive simulation of thermo-hydraulic system codes

    Within the scope of this thesis the development of methods for online-adaptation of dynamical plant simulations of a thermal-hydraulic system code to measurement data is depicted. The described approaches are mainly based on the use of sensitivity-information in different areas: statistical sensitivity measures are used for the identification of the parameters to be adapted and online-sensitivities for the parameter adjustment itself. For the parameter adjustment the method of a ''system-adapted heuristic adaptation with partial separation'' (SAHAT) was developed, which combines certain variants of parameter estimation and control with supporting procedures to solve the basic problems. The applicability of the methods is shown by adaptive simulations of a PKL-III experiment and by selected transients in a nuclear power plant. Finally the main perspectives for the application of a tracking simulator on a system code are identified.

  6. Computerized adaptive measurement of depression: A simulation study

    Mammen Oommen

    2004-05-01

    Full Text Available Abstract Background Efficient, accurate instruments for measuring depression are increasingly important in clinical practice. We developed a computerized adaptive version of the Beck Depression Inventory (BDI. We examined its efficiency and its usefulness in identifying Major Depressive Episodes (MDE and in measuring depression severity. Methods Subjects were 744 participants in research studies in which each subject completed both the BDI and the SCID. In addition, 285 patients completed the Hamilton Depression Rating Scale. Results The adaptive BDI had an AUC as an indicator of a SCID diagnosis of MDE of 88%, equivalent to the full BDI. The adaptive BDI asked fewer questions than the full BDI (5.6 versus 21 items. The adaptive latent depression score correlated r = .92 with the BDI total score and the latent depression score correlated more highly with the Hamilton (r = .74 than the BDI total score did (r = .70. Conclusions Adaptive testing for depression may provide greatly increased efficiency without loss of accuracy in identifying MDE or in measuring depression severity.

  7. Life on the edge: Vulnerability and adaptation of African ecosystems to global climate change

    Dixon, R; J. Smith; Guill, S.

    2003-01-01

    Donor countries are providing financial and technical support for global climate change country studies to help African nations meet their reporting needs under the United Nations Framework Convention on Climate Change (UNFCCC). Technical assistance to complete vulnerability and adaptation assessments includes training of analysts, sharing of contemporary tools (e.g. simulation models), data and assessment techniques, information-sharing workshops and an international exchange programme for a...

  8. Cross-cultural adaptation of the Quality of Life Index Spinal Cord Injury - Version III

    Priscila Alencar Mendes Reis

    2015-06-01

    Full Text Available OBJECTIVE To translate and culturally adapt to Portuguese the Ferrans and Powers Quality of Life Index Spinal Cord Injury - Version III and characterize the sample in relation to sociodemographic and clinical aspects. METHOD A methodological study with view to cross-cultural adaptation, following the particular steps of this method: initial translation, translation synthesis, back-translation (translation back to the original language, review by a committee of judges and pretest of the final version. The pretest was carried out with 30 patients with spinal cord injury. RESULTS An index of 74 items divided into two parts (satisfaction/importance was obtained. The criteria of semantic equivalence were evaluated as very adequate translation, higher than 87%, and vocabulary and were grammar higher than 86%. Idiomatic equivalence was higher than 74%, experimental greater than 78% and conceptual was greater than 70%. CONCLUSION After cross-cultural adaptation, the instrument proved semantic, idiomatic, experimental and conceptual adequacy, in addition to helping the evaluation of the quality of life of people with spinal cord injury.

  9. RISKS FOR FAMILY LIFE OF RUSSIAN RESERVE MILITARY SERVANTS IN THE CONTEXT OF SOCIAL ADAPTATION TO CIVILIAN LIFE

    Pavel Viktorovich Razov

    2015-01-01

    Full Text Available The article analyzes the risks for family life of military servants transferred into the reserve. The risks are influenced by a number of factors that have common foundations for Russian families in the context of their functional transformation as well as specific foundations depending on the nature of their formation and development within a close socio-professional system. In this regard, it is necessary to provide social and psychological support to the families of transferred to reserve servicemen, for whom preservation of the family and stable family relationships becomes a pressing problem, as well as professional adaptation to the new social conditions. Specificity of military servants’ families is in the fact that they are directly dependent on the state and public policy, what determines the high importance of state regulation in the field of social adaptation of servicemen and their families. The author shows that the specificity of military families is largely due to the conditions of their formation and development, influenced by the close social system, which determines the uncontested acceptance of the values and norms of the system (the military environment by all members of the family.

  10. Adaptive resolution simulation of supramolecular water : The concurrent making, breaking, and remaking of water bundles

    Zavadlav, Julija; Marrink, Siewert J; Praprotnik, Matej

    2016-01-01

    The adaptive resolution scheme (AdResS) is a multiscale molecular dynamics simulation approach that can concurrently couple atomistic (AT) and coarse-grained (CG) resolution regions, i.e., the molecules can freely adapt their resolution according to their current position in the system. Coupling to

  11. A Simulation Model for the Waterfall Software Development Life Cycle

    Bassil, Youssef

    2012-01-01

    Software development life cycle or SDLC for short is a methodology for designing, building, and maintaining information and industrial systems. So far, there exist many SDLC models, one of which is the Waterfall model which comprises five phases to be completed sequentially in order to develop a software solution. However, SDLC of software systems has always encountered problems and limitations that resulted in significant budget overruns, late or suspended deliveries, and dissatisfied clients. The major reason for these deficiencies is that project directors are not wisely assigning the required number of workers and resources on the various activities of the SDLC. Consequently, some SDLC phases with insufficient resources may be delayed; while, others with excess resources may be idled, leading to a bottleneck between the arrival and delivery of projects and to a failure in delivering an operational product on time and within budget. This paper proposes a simulation model for the Waterfall development proce...

  12. Online Body Schema Adaptation Based on Internal Mental Simulation and Multisensory Feedback

    Vicente, Pedro; Jamone, Lorenzo; Bernardino, Alexandre

    2016-01-01

    In this paper, we describe a novel approach to obtain automatic adaptation of the robot body schema and to improve the robot perceptual and motor skills based on this body knowledge. Predictions obtained through a mental simulation of the body are combined with the real sensory feedback to achieve two objectives simultaneously: body schema adaptation and markerless 6D hand pose estimation. The body schema consists of a computer graphics simulation of the robot, which includes the arm and head...

  13. Design of a virtual environment with adaptation of immersion for wheelchair driving simulation

    Goncalves, Frédéric

    2014-01-01

    This thesis focuses on the adaptation of the immersion in a driving wheelchair simulation. This is the study of sensory feedback realism involved in a virtual environment in order to adapt the immersion according to user preferences and the task to perform. These works were performed within the AccesSim project supported by the Ile de France region. The project objective is to develop a dynamic simulator to evaluate the accessibility and also urban environment, to conduct training in the use ...

  14. Parallel Simulation of the Shallow Water Equations on Structured Dynamically Adaptive Triangular Grids.

    Vigh, Csaba Attila

    2013-01-01

    One of the most important computational challenges in the context of the numerical treatment of Partial Differential Equations is the generation, management, and dynamic adaptivity of grids. Dynamic adaptivity is extremely important in applications that require frequent changes of the grid pattern during a simulation run. One such application example is Tsunami simulation, where waves have to be tracked with highly resolved local grids. Arbitrary unstructured grids that can ...

  15. The New England Climate Adaptation Project: Enhancing Local Readiness to Adapt to Climate Change through Role-Play Simulations

    Rumore, D.; Kirshen, P. H.; Susskind, L.

    2014-12-01

    Despite scientific consensus that the climate is changing, local efforts to prepare for and manage climate change risks remain limited. How we can raise concern about climate change risks and enhance local readiness to adapt to climate change's effects? In this presentation, we will share the lessons learned from the New England Climate Adaptation Project (NECAP), a participatory action research project that tested science-based role-play simulations as a tool for educating the public about climate change risks and simulating collective risk management efforts. NECAP was a 2-year effort involving the Massachusetts Institute of Technology, the Consensus Building Institute, the National Estuarine Research Reserve System, and four coastal New England municipalities. During 2012-2013, the NECAP team produced downscaled climate change projections, a summary risk assessment, and a stakeholder assessment for each partner community. Working with local partners, we used these assessments to create a tailored, science-based role-play simulation for each site. Through a series of workshops in 2013, NECAP engaged between 115-170 diverse stakeholders and members of the public in each partner municipality in playing the simulation and a follow up conversation about local climate change risks and possible adaptation strategies. Data were collected through before-and-after surveys administered to all workshop participants, follow-up interviews with 25 percent of workshop participants, public opinion polls conducted before and after our intervention, and meetings with public officials. This presentation will report our research findings and explain how science-based role-play simulations can be used to help communicate local climate change risks and enhance local readiness to adapt.

  16. Toward a practical method for adaptive QM/MM simulations

    R.E. Bulo; B. Ensing; J. Sikkema; L. Visscher

    2009-01-01

    We present an accurate adaptive multiscale molecular dynamics method that will enable the detailed study of large molecular systems that mimic experiment. The method treats the reactive regions at the quantum mechanical level and the inactive environment regions at lower levels of accuracy, while at

  17. Adaptation and validation of stroke-aphasia quality of life (SAQOL-39 scale to Malayalam

    Ria Raju

    2015-01-01

    Full Text Available Background: Aphasia, an acquired inability to understand and/or speak language, is a common repercussion of stroke that denigrates the quality of life (QOL in the affected persons. Several languages in India experience the dearth of instruments to measure the QOL of persons with aphasia. Malayalam, the language spoken by more than 33 million people in Kerala, the southern state of India, is not an exception to this. Objective: This study aimed to adapt and validate the widely-used stroke-aphasia quality of life (SAQOL-39 scale to Malayalam. Materials and Methods: We required seven Malayalam-speaking Speech Language Pathologists (SLPs, hailing from different regions of Kerala, to examine the socio-cultural suitability of the original items in SAQOL-39 and indicate modifications, wherever necessary. Subsequently, the linguistic adaptation was performed through a forward-backward translation scheme. The socio-culturally and linguistically adapted Malayalam version was then administered on a group of 48 Malayalam-speaking persons with aphasia to examine the test-retest reliability, acceptability, as well as the internal consistency of the instrument. Results: The Malayalam SAQOL-39 scale showed high test-retest reliability (intraclass correlation coefficient, ICC = 0.91 as well as acceptability with minimal missing data (0.52%. Further, it yielded high internal consistency (Chronbach′s ∝ = 0.98 as well as item-to-total and inter-domain correlations. Conclusions: The Malayalam version of SAQOL-39 is the first socio-culturally and linguistically adapted tool to measure the QOL of persons with stroke-aphasia speaking this language. It may serve as a potential tool to measure the QOL of this population in both clinical practice and future research endeavors.

  18. Adaptation and validation of stroke-aphasia quality of life (SAQOL-39 scale to Hindi

    Ishita H Mitra

    2015-01-01

    Full Text Available Background: Stroke is a major detriment to the quality of life (QOL in its victims. Several functional limitations following stroke contribute to the denigrated QOL in this population. Aphasia, a disturbance in the comprehension, processing, and/or expression of language, is a common consequence of stroke. Yet, in most Indian languages, including the national language (Hindi, there are no published tools to measure the QOL of persons with stroke-aphasia. Objective: The current study was carried out to adapt and validate a well-known tool to measure the QOL (i.e., Stroke-Aphasia Quality of Life-39; SAQOL-39 to Hindi. Materials and Methods: We presented the original (English version of the SAQOL-39 to a group of six Hindi-speaking Speech Language Pathologists hailing from the central and northern regions of India to examine the sociocultural suitability of items and indicate modifications, if any. The linguistic adaptation was performed through a forward-backward translation scheme. The socioculturally and linguistically adapted (to Hindi version was then administered on a group of 84 Hindi-speaking persons with aphasia to examine the acceptability, test-retest reliability as well as the internal consistency of the instrument. Results: The SAQOL-39 in Hindi exhibited high test-retest reliability (ICC = 0.9 as well as acceptability with minimal missing data. This instrument exhibited high internal consistency (Chronbach′s ∝ = 0.98 as well as the both item-to-total and inter-domain correlations. Conclusions: The socioculturally and linguistically adapted Hindi version of SAQOL-39 is a robust tool to measure the QOL of persons with stroke-aphasia. It may serve as an essential tool to measure the QOL in this population for both clinical and research purposes.

  19. Adapt and Cope: Strategies for Safeguarding the Quality of Life in a Shrinking Ageing Region

    Dr. Annett Steinführer

    2014-06-01

    Full Text Available This article examines the adaptation and coping strategies that are in place to safeguard the quality of life in a shrinking ageing region. In particular, it is investigated which resources are available to local policy-makers and the older population in order to pursue this goal. Following an introduction to the debate of regional science about demographic change and its consequences, we introduce a theoretical differentiation between adaptation and coping. Adaptation strategies refer to the decision-makers who provide or are involved in organising public service facilities. Coping strategies and capacities refer to the customers and users affected by the changes. The population is not only passively affected by changes in public services, but also actively grapples with changed levels of infrastructure and takes up measures to safeguard their own quality of life. Empirically, we employ the results of semi-structured interviews with local and regional key persons and group interviews with elderly inhabitants of two small towns in the Harz region. The region under study is among the most ageing rural areas in Germany. Its demographic characteristics are based on many years of selective out-migration and partially age-selective in-migration. The research results reveal many measures and strategies which have been developed and employed by the different actor groups when faced with tangible problems. However, they have not been planned with a long term perspective. The availability of economic and social resources (human resources and investment funds on the part of administrations, fi nancial resources and social networks on the part of the older population is the chief differentiating and often limiting factor for the success of these measures and strategies. This article comes to the conclusion that adaptation and coping will remain processes for safeguarding the quality of life in shrinking ageing regions for the longer term. In addition to

  20. Challenges of adaptation to working life in Turkey – The Finnish Perspective

    Falck, Julia

    2016-01-01

    The purpose of this thesis was to find out what challenges Finns face in adaptation to working life in Turkey. The objective of the thesis was to understand Turkish and Finnish cultures and by comparing them to find out possible challenges that a Finnish employee might face in Turkish working environment. The theoretical section of this thesis includes a comparison of various cultural features according to Hofstede’s dimensions and a comparison of Finland’s and Turkey’s working cultures a...

  1. Cross-cultural adaptation and validation of Behçet's disease quality of life questionnaire

    Menassa Jeanine; Hamdan Omar; Hamdan Ayad; Puzantian Houry; Sibai Abla; Ghandour Lilian; Touma Zahi; Uthman Imad; Arayssi Thurayya

    2011-01-01

    Abstract Background Currently, there is one Behçet's disease (BD) specific self reporting questionnaire developed and published in the literature, The Leeds BD-quality of life (QoL). We conducted a cross-cultural adaptation and validation of the Arabic version of the Leeds BD-QoL Methods A cross-sectional study was conducted among 41 consecutive patients attending rheumatology clinics at the American University of Beirut Medical Center between June and December 2007. The BD-QoL questionnaire,...

  2. Indicators of quality of life and adaptation to chronic tense headaches

    Abramenko Y.V.; Selyankina Y.N.; Zueva G.A.; Serebrova T.V.; Slyusar T.A.

    2012-01-01

    The goal of the research is the comparative analysis of a quality of life and quantitative characteristics of a chronic tense headache as well as the studying of adaptive reactions. 123 women (middle age 42,6±2,3) with initiatory stages of chronic tense headaches have been examined using diagnostic criteria of the International classifcation of headache disorders (ICDH — II, 2003), headache diary and the McGill Pain Questionnaire. Headache intensity was estimated by the Visual Analog...

  3. Computer simulation program is adaptable to industrial processes

    Schultz, F. E.

    1966-01-01

    The Reaction kinetics ablation program /REKAP/, developed to simulate ablation of various materials, provides mathematical formulations for computer programs which can simulate certain industrial processes. The programs are based on the use of nonsymmetrical difference equations that are employed to solve complex partial differential equation systems.

  4. Grappling with Gravity How Will Life Adapt to Living in Space?

    Phillips, Robert W

    2012-01-01

    Grappling with Gravity explores the physiological changes that will occur in humans and the plants and animals that accompany humans as we move to new worlds, whether it be to a colony in the emptiness of space or settlements on the moon, Mars, or other moons or planets. This book focuses on the biomedical aspects, while not ignoring other life-changing influences of space living. For example, what happens to people physiologically in the microgravity of space, where weight and the direction "up" are meaningless? Adapting to microgravity represents the greatest physical challenge that human life will have encountered since our ancestors moved from the seas to solid Earth. It will be the next great adventure!

  5. Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts

    Ma, Liang; Chen, Zehua; Huang, Da Wei; Kutty, Geetha; Ishihara, Mayumi; Wang, Honghui; Abouelleil, Amr; Bishop, Lisa; Davey, Emma; Deng, Rebecca; Deng, Xilong; Fan, Lin; Fantoni, Giovanna; Fitzgerald, Michael; Gogineni, Emile; Goldberg, Jonathan M.; Handley, Grace; Hu, Xiaojun; Huber, Charles; Jiao, Xiaoli; Jones, Kristine; Levin, Joshua Z.; Liu, Yueqin; Macdonald, Pendexter; Melnikov, Alexandre; Raley, Castle; Sassi, Monica; Sherman, Brad T.; Song, Xiaohong; Sykes, Sean; Tran, Bao; Walsh, Laura; Xia, Yun; Yang, Jun; Young, Sarah; Zeng, Qiandong; Zheng, Xin; Stephens, Robert; Nusbaum, Chad; Birren, Bruce W.; Azadi, Parastoo; Lempicki, Richard A.; Cuomo, Christina A.; Kovacs, Joseph A.

    2016-01-01

    Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses. PMID:26899007

  6. Genome analysis of three Pneumocystis species reveals adaptation mechanisms to life exclusively in mammalian hosts.

    Ma, Liang; Chen, Zehua; Huang, Da Wei; Kutty, Geetha; Ishihara, Mayumi; Wang, Honghui; Abouelleil, Amr; Bishop, Lisa; Davey, Emma; Deng, Rebecca; Deng, Xilong; Fan, Lin; Fantoni, Giovanna; Fitzgerald, Michael; Gogineni, Emile; Goldberg, Jonathan M; Handley, Grace; Hu, Xiaojun; Huber, Charles; Jiao, Xiaoli; Jones, Kristine; Levin, Joshua Z; Liu, Yueqin; Macdonald, Pendexter; Melnikov, Alexandre; Raley, Castle; Sassi, Monica; Sherman, Brad T; Song, Xiaohong; Sykes, Sean; Tran, Bao; Walsh, Laura; Xia, Yun; Yang, Jun; Young, Sarah; Zeng, Qiandong; Zheng, Xin; Stephens, Robert; Nusbaum, Chad; Birren, Bruce W; Azadi, Parastoo; Lempicki, Richard A; Cuomo, Christina A; Kovacs, Joseph A

    2016-01-01

    Pneumocystis jirovecii is a major cause of life-threatening pneumonia in immunosuppressed patients including transplant recipients and those with HIV/AIDS, yet surprisingly little is known about the biology of this fungal pathogen. Here we report near complete genome assemblies for three Pneumocystis species that infect humans, rats and mice. Pneumocystis genomes are highly compact relative to other fungi, with substantial reductions of ribosomal RNA genes, transporters, transcription factors and many metabolic pathways, but contain expansions of surface proteins, especially a unique and complex surface glycoprotein superfamily, as well as proteases and RNA processing proteins. Unexpectedly, the key fungal cell wall components chitin and outer chain N-mannans are absent, based on genome content and experimental validation. Our findings suggest that Pneumocystis has developed unique mechanisms of adaptation to life exclusively in mammalian hosts, including dependence on the lungs for gas and nutrients and highly efficient strategies to escape both host innate and acquired immune defenses. PMID:26899007

  7. Cross-cultural adaptation and validation of Behçet's disease quality of life questionnaire

    2011-01-01

    Background Currently, there is one Behçet's disease (BD) specific self reporting questionnaire developed and published in the literature, The Leeds BD-quality of life (QoL). We conducted a cross-cultural adaptation and validation of the Arabic version of the Leeds BD-QoL Methods A cross-sectional study was conducted among 41 consecutive patients attending rheumatology clinics at the American University of Beirut Medical Center between June and December 2007. The BD-QoL questionnaire, the Katz Index of Activities of Daily Living (ADL) and the Lawton Instrumental Activities of Daily Living (IADL) questionnaires were co-administered during the same visit, and severity scores were calculated. Cross-cultural adaptation of BD-QoL was performed using forward and backward translations of the original questionnaire. Internal consistency and test-retest reliability of the final version were determined. Exploratory Factor Analysis (EFA) was used to assess the dimensionality of the scale items. External construct validity was examined by correlating Arabic BD-QoL with the severity score, ADL and IADL. Results The 30 items of the adapted Arabic BD-QoL showed a high internal consistency (KR-20 coefficient 0.89) and test-retest reliability (Spearman's test 0.91). The convergence of all 30 items suggests that the 30-item adapted Arabic BD-QoL scale is unidimensional. BD-QoL did not correlate with any of the patients' demographics. Still, it was positively correlated with patient severity score (r 0.4, p 0.02), and IADL (but not ADL). Conclusions This cross-cultural adaptation has produced an Arabic BD-QoL questionnaire that is now available for use in clinical settings and in research studies, among Arabic speaking patients. PMID:21507231

  8. Cross-cultural adaptation and validation of Behçet's disease quality of life questionnaire

    Menassa Jeanine

    2011-04-01

    Full Text Available Abstract Background Currently, there is one Behçet's disease (BD specific self reporting questionnaire developed and published in the literature, The Leeds BD-quality of life (QoL. We conducted a cross-cultural adaptation and validation of the Arabic version of the Leeds BD-QoL Methods A cross-sectional study was conducted among 41 consecutive patients attending rheumatology clinics at the American University of Beirut Medical Center between June and December 2007. The BD-QoL questionnaire, the Katz Index of Activities of Daily Living (ADL and the Lawton Instrumental Activities of Daily Living (IADL questionnaires were co-administered during the same visit, and severity scores were calculated. Cross-cultural adaptation of BD-QoL was performed using forward and backward translations of the original questionnaire. Internal consistency and test-retest reliability of the final version were determined. Exploratory Factor Analysis (EFA was used to assess the dimensionality of the scale items. External construct validity was examined by correlating Arabic BD-QoL with the severity score, ADL and IADL. Results The 30 items of the adapted Arabic BD-QoL showed a high internal consistency (KR-20 coefficient 0.89 and test-retest reliability (Spearman's test 0.91. The convergence of all 30 items suggests that the 30-item adapted Arabic BD-QoL scale is unidimensional. BD-QoL did not correlate with any of the patients' demographics. Still, it was positively correlated with patient severity score (r 0.4, p 0.02, and IADL (but not ADL. Conclusions This cross-cultural adaptation has produced an Arabic BD-QoL questionnaire that is now available for use in clinical settings and in research studies, among Arabic speaking patients.

  9. UNFOLDING SIMULATIONS OF COLD- AND WARM-ADAPTED ELASTASES

    Laura Riccardi1, Papaleo Elena2 *

    2010-01-01

    The earth surface is dominated by low temperature environments, which have been successfully colonized by several extremophilic organisms. Enzymes isolated from psychrophilic organisms are able to catalyze reactions at low temperatures at which enzymes from mesophiles or thermophiles are fully compromised. The current scenario on enzyme cold-adaptation suggest that these enzymes are characterized by higher catalytic efficiently at low temperatures, enhanced structural flexibility and lower th...

  10. A Bacterial-Based Algorithm to Simulate Complex Adaptative Systems

    González Rodríguez, Diego; Hernández Carrión, José Rodolfo

    2014-01-01

    Bacteria have demonstrated an amazing capacity to overcome envi-ronmental changes by collective adaptation through genetic exchanges. Using a distributed communication system and sharing individual strategies, bacteria propagate mutations as innovations that allow them to survive in different envi-ronments. In this paper we present an agent-based model which is inspired by bacterial conjugation of DNA plasmids. In our approach, agents with bounded rationality interact in a common environment ...

  11. Adaptive Use of Information during Growth Can Explain Long-Term Effects of Early Life Experiences.

    English, Sinead; Fawcett, Tim W; Higginson, Andrew D; Trimmer, Pete C; Uller, Tobias

    2016-05-01

    Development is a continuous process during which individuals gain information about their environment and adjust their phenotype accordingly. In many natural systems, individuals are particularly sensitive to early life experiences, even in the absence of later constraints on plasticity. Recent models have highlighted how the adaptive use of information can explain age-dependent plasticity. These models assume that information gain and phenotypic adjustments either cannot occur simultaneously or are completely independent. This assumption is not valid in the context of growth, where finding food results both in a size increase and learning about food availability. Here, we describe a simple model of growth to provide proof of principle that long-term effects of early life experiences can arise through the coupled dynamics of information acquisition and phenotypic change in the absence of direct constraints on plasticity. The increase in reproductive value from gaining information and sensitivity of behavior to experiences declines across development. Early life experiences have long-term impacts on age of maturity, yet-due to compensatory changes in behavior-our model predicts no substantial effects on reproductive success. We discuss how the evolution of sensitive windows can be explained by experiences having short-term effects on informational and phenotypic states, which generate long-term effects on life-history decisions. PMID:27104994

  12. The Cultural Adaptation Process of Agricultural and Life Sciences Students on Short-Term Study Abroad Experiences

    Conner, Nathan William

    2013-01-01

    The purpose of this study was to explore how undergraduate students in a college of agricultural and life sciences experienced cultural adaptation during short-term study abroad programs. The specific objectives of this study were to describe how undergraduate students in the college of agricultural and life sciences experienced culture throughout…

  13. Fuzzy Backstepping Torque Control Of Passive Torque Simulator With Algebraic Parameters Adaptation

    Ullah, Nasim; Wang, Shaoping; Wang, Xingjian

    2015-07-01

    This work presents fuzzy backstepping control techniques applied to the load simulator for good tracking performance in presence of extra torque, and nonlinear friction effects. Assuming that the parameters of the system are uncertain and bounded, Algebraic parameters adaptation algorithm is used to adopt the unknown parameters. The effect of transient fuzzy estimation error on parameters adaptation algorithm is analyzed and the fuzzy estimation error is further compensated using saturation function based adaptive control law working in parallel with the actual system to improve the transient performance of closed loop system. The saturation function based adaptive control term is large in the transient time and settles to an optimal lower value in the steady state for which the closed loop system remains stable. The simulation results verify the validity of the proposed control method applied to the complex aerodynamics passive load simulator.

  14. Electromagnetic compatibility of WLAN adapters with life-supporting medical devices.

    Calcagnini, G; Mattei, E; Censi, F; Triventi, M; Lo Sterzo, R; Marchetta, E; Bartolini, P

    2011-05-01

    This paper investigates the electromagnetic compatibility of 45 critical care medical devices (infusion pumps, defibrillators, monitors, lung ventilators, anesthesia machines and external pacemakers) with various types of wireless local area network (WLAN, IEEE 802.11 b/g, 2.45 GHz, 100 mW) adapters. Interference is evaluated by performing ad-hoc tests according to the ANSI C63.18 recommended practice. The behavior of the devices during the tests was monitored using patient simulators/device testers specific for each device class. Electromagnetic interference cases were observed in three of 45 devices at a maximum distance of 5 cm. In two cases the interference caused malfunctions that may have clinical consequences for the patient. The authors' findings show that the use of these wireless local area network adapters can be considered reasonably safe, although interference may occur if they are operated at very close distance (<10 cm) to the medical devices. PMID:21451319

  15. Life History Variation in an Alpine Caddisfly: Local Adaptation or Phenotypic Plasticity?

    Shama, L. N.; Robinson, C. T.

    2005-05-01

    Facultative species that inhabit permanent and temporary streams can be locally adapted to their stream of origin or exhibit life history plasticity. Temporary stream populations should respond to environmental cues signalling stream drying, whereas permanent stream populations may not. We used a common garden experiment to test whether males and females of an alpine caddisfly from six populations (3 permanent/3 temporary streams) differed in their life history responses to combined changes in photoperiod (ambient/late) and hydroperiod (constant/drying). Responses varied by sex, time-constraint cue and population. Both sexes shortened development time in the late photoperiod, and males emerged before females in all treatments. Growth rates were higher in the late photoperiod for both sexes, and females had higher growth rates and mass at emergence than males. Growth rate compensation in the late photoperiod resulted in similar masses at emergence for both photoperiods. Population-level differences in responses varied according to microgeographic co-gradient variation. Our results suggest that while stream drying cues may not exert sufficient selection pressure to promote faster development in temporary streams, populations may be locally adapted to differences in growing season length associated with stream-specific environmental characteristics.

  16. Cartesian Off-Body Grid Adaption for Viscous Time- Accurate Flow Simulation

    Buning, Pieter G.; Pulliam, Thomas H.

    2011-01-01

    An improved solution adaption capability has been implemented in the OVERFLOW overset grid CFD code. Building on the Cartesian off-body approach inherent in OVERFLOW and the original adaptive refinement method developed by Meakin, the new scheme provides for automated creation of multiple levels of finer Cartesian grids. Refinement can be based on the undivided second-difference of the flow solution variables, or on a specific flow quantity such as vorticity. Coupled with load-balancing and an inmemory solution interpolation procedure, the adaption process provides very good performance for time-accurate simulations on parallel compute platforms. A method of using refined, thin body-fitted grids combined with adaption in the off-body grids is presented, which maximizes the part of the domain subject to adaption. Two- and three-dimensional examples are used to illustrate the effectiveness and performance of the adaption scheme.

  17. Whole genome sequencing of turbot (Scophthalmus maximus; Pleuronectiformes): a fish adapted to demersal life

    Figueras, Antonio; Robledo, Diego; Corvelo, André; Hermida, Miguel; Pereiro, Patricia; Rubiolo, Juan A.; Gómez-Garrido, Jèssica; Carreté, Laia; Bello, Xabier; Gut, Marta; Gut, Ivo Glynne; Marcet-Houben, Marina; Forn-Cuní, Gabriel; Galán, Beatriz; García, José Luis; Abal-Fabeiro, José Luis; Pardo, Belen G.; Taboada, Xoana; Fernández, Carlos; Vlasova, Anna; Hermoso-Pulido, Antonio; Guigó, Roderic; Álvarez-Dios, José Antonio; Gómez-Tato, Antonio; Viñas, Ana; Maside, Xulio; Gabaldón, Toni; Novoa, Beatriz; Bouza, Carmen; Alioto, Tyler; Martínez, Paulino

    2016-01-01

    The turbot is a flatfish (Pleuronectiformes) with increasing commercial value, which has prompted active genomic research aimed at more efficient selection. Here we present the sequence and annotation of the turbot genome, which represents a milestone for both boosting breeding programmes and ascertaining the origin and diversification of flatfish. We compare the turbot genome with model fish genomes to investigate teleost chromosome evolution. We observe a conserved macrosyntenic pattern within Percomorpha and identify large syntenic blocks within the turbot genome related to the teleost genome duplication. We identify gene family expansions and positive selection of genes associated with vision and metabolism of membrane lipids, which suggests adaptation to demersal lifestyle and to cold temperatures, respectively. Our data indicate a quick evolution and diversification of flatfish to adapt to benthic life and provide clues for understanding their controversial origin. Moreover, we investigate the genomic architecture of growth, sex determination and disease resistance, key traits for understanding local adaptation and boosting turbot production, by mapping candidate genes and previously reported quantitative trait loci. The genomic architecture of these productive traits has allowed the identification of candidate genes and enriched pathways that may represent useful information for future marker-assisted selection in turbot. PMID:26951068

  18. Intelligent Electric Power Systems with Active-Adaptive Electric Networks: Challenges for Simulation Tools

    Ufa Ruslan A.

    2015-01-01

    Full Text Available The motivation of the presented research is based on the needs for development of new methods and tools for adequate simulation of intelligent electric power systems with active-adaptive electric networks (IES including Flexible Alternating Current Transmission System (FACTS devices. The key requirements for the simulation were formed. The presented analysis of simulation results of IES confirms the need to use a hybrid modelling approach.

  19. Modeling and Simulation of Sport Games, Sport Movements, and Adaptations to Training (Dagstuhl Seminar 15382)

    Duarte, Ricardo; Eskofier, Björn; Rumpf, Martin; Wiemeyer, Josef

    2016-01-01

    This report documents the program and the outcomes of Dagstuhl Seminar 15382 "Modeling and Simulation of Sport Games, Sport Movements, and Adaptations to Training". The primary goal of the seminar was the continuation of the interdisciplinary and transdisciplinarity research in sports and computer science with the emphasis on modeling and simulation technologies. In this seminar, experts on modeling and simulation from computer science, sport science, and industry were invited to discuss rece...

  20. The numerical simulation tool for the MAORY multiconjugate adaptive optics system

    Arcidiacono, Carmelo; Bregoli, Giovanni; Diolaiti, Emiliano; Foppiani, Italo; Agapito, Guido; Puglisi, Alfio; Xompero, Marco; Oberti, Sylvain; Cosentino, Giuseppe; Lombini, Matteo; Butler, Chris R; Ciliegi, Paolo; Cortecchia, Fausto; Patti, Mauro; Esposito, Simone; Feautrier, Philippe

    2016-01-01

    The Multiconjugate Adaptive Optics RelaY (MAORY) is and Adaptive Optics module to be mounted on the ESO European-Extremely Large Telescope (E-ELT). It is a hybrid Natural and Laser Guide System that will perform the correction of the atmospheric turbulence volume above the telescope feeding the Multi-AO Imaging Camera for Deep Observations Near Infrared spectro-imager (MICADO). We developed an end-to-end Monte- Carlo adaptive optics simulation tool to investigate the performance of a the MAORY and the calibration, acquisition, operation strategies. MAORY will implement Multiconjugate Adaptive Optics combining Laser Guide Stars (LGS) and Natural Guide Stars (NGS) measurements. The simulation tool implements the various aspect of the MAORY in an end to end fashion. The code has been developed using IDL and uses libraries in C++ and CUDA for efficiency improvements. Here we recall the code architecture, we describe the modeled instrument components and the control strategies implemented in the code.

  1. Social adaptation and quality of life in reproductive-aged women with epilepsy

    Diana Viktorovna Dmitrenko

    2015-10-01

    Full Text Available The quality-of-life indicators are integral characteristics of treatment and diagnostic measures in modern epileptology.Objective: to assess the social adaptation and quality of life in reproductive-aged women with epilepsy.Subjects and methods. A sociological survey using the Quality of Life Satisfaction questionnaire and the European Quality of Life-5 Dimensions (EQ-5D was carried out in 352 women living in the Krasnoyarsk Territory.Results. At the time of the study, 21.3% of the patients were unemployed. Disability related to epilepsy was in 13.1% of women, mainly in those with cryptogenic (22.3% and symptomatic (14.4% epilepsy. Most of the women were unsatisfied with their job activity (55.1%, financial status (64.6%, and physical health (65.3%. Mainly the patients with symptomatic epilepsy reported dissatisfaction with their psychological status. The patients had employment problems (12.5%, inability to work in their specialty (12.5% and to get the desired specialty (10.3%, and labor maladaptation (8.8%. There was a preponderance of women with higher education (40.3% and 21.3% continued their studies. Warm family relations and help from relatives and friends (65.4%, hope for their recovery (50.7%, contacts with their friends (30.1%, and plans for future (34.6% were important for the women to control the disease.Conclusions. The findings suggest that family, personal, maternity problems are more important causes of social maladaptation in epileptic women.

  2. Computerized adaptive testing of population psychological distress:simulation-based evaluation of GHQ-30

    Stochl, Jan; Böhnke, Jan R.; Pickett, Kate E.; Croudace, Tim J.

    2015-01-01

    PURPOSE: Goldberg's General Health Questionnaire (GHQ) items are frequently used to assess psychological distress but no study to date has investigated the GHQ-30's potential for adaptive administration. In computerized adaptive testing (CAT) items are matched optimally to the targeted distress level of respondents instead of relying on fixed-length versions of instruments. We therefore calibrate GHQ-30 items and report a simulation study exploring the potential of this instrument for adaptiv...

  3. An adaptative finite element method for turbulent flow simulations

    After outlining the space and time discretization methods used in the N3S thermal hydraulic code developed at EDF/NHL, we describe the possibilities of the peripheral version, the Adaptative Mesh, which comprises two separate parts: the error indicator computation and the development of a module subdividing elements usable by the solid dynamics code ASTER and the electromagnetism code TRIFOU also developed by R and DD. The error indicators implemented in N3S are described. They consist of a projection indicator quantifying the space error in laminar or turbulent flow calculations and a Navier-Stokes residue indicator calculated on each element. The method for subdivision of triangles into four sub-triangles and tetrahedra into eight sub-tetrahedra is then presented with its advantages and drawbacks. It is illustrated by examples showing the efficiency of the module. The last concerns the 2 D case of flow behind a backward-facing step. (authors). 9 refs., 5 figs., 1 tab

  4. Cluster Optimization and Parallelization of Simulations with Dynamically Adaptive Grids

    Schreiber, Martin

    2013-01-01

    The present paper studies solvers for partial differential equations that work on dynamically adaptive grids stemming from spacetrees. Due to the underlying tree formalism, such grids efficiently can be decomposed into connected grid regions (clusters) on-the-fly. A graph on those clusters classified according to their grid invariancy, workload, multi-core affinity, and further meta data represents the inter-cluster communication. While stationary clusters already can be handled more efficiently than their dynamic counterparts, we propose to treat them as atomic grid entities and introduce a skip mechanism that allows the grid traversal to omit those regions completely. The communication graph ensures that the cluster data nevertheless are kept consistent, and several shared memory parallelization strategies are feasible. A hyperbolic benchmark that has to remesh selected mesh regions iteratively to preserve conforming tessellations acts as benchmark for the present work. We discuss runtime improvements resulting from the skip mechanism and the implications on shared memory performance and load balancing. © 2013 Springer-Verlag.

  5. Numerical simulation of supersonic over/under expanded jets using adaptive grid

    Numerical simulation of supersonic under and over expanded jet was simulated. In order to achieve the solution efficiently and with high resolution, adaptive grid is used. The axisymmetric compressible, time dependent Navier-Stokes equations in body fitted curvilinear coordinate were solved numerically. The equations were discretized by using control volume, and the Van Leer flux splitting approach. The equations were solved implicitly. The obtained computer code was used to simulate four different cases of moderate and strong under and over expanded jet flows. The results show that with the adaptation of the grid, the various features of this complicated flow can be observed. It was shown that the adaptation method is very efficient and has the ability to make fine grids near the high gradient regions. (author)

  6. Using statistical sensitivities for adaptation of a best-estimate thermo-hydraulic simulation model

    On-line adaptation of best-estimate simulations of NPP behaviour to time-dependent measurement data can be used to insure that simulations performed in parallel to plant operation develop synchronously with the real plant behaviour even over extended periods of time. This opens a range of applications including operator support in non-standard-situations, improving diagnostics and validation of measurements in real plants or experimental facilities. A number of adaptation methods have been proposed and successfully applied to control problems. However, these methods are difficult to be applied to best-estimate thermal-hydraulic codes, such as TRACE and ATHLET, with their large nonlinear differential equation systems and sophisticated time integration techniques. This paper presents techniques to use statistical sensitivity measures to overcome those problems by reducing the number of parameters subject to adaptation. It describes how to identify the most significant parameters for adaptation and how this information can be used by combining: -decomposition techniques splitting the system into a small set of component parts with clearly defined interfaces where boundary conditions can be derived from the measurement data, -filtering techniques to insure that the time frame for adaptation is meaningful, -numerical sensitivities to find minimal error conditions. The suitability of combining those techniques is shown by application to an adaptive simulation of the PKL experiment.

  7. Role-play simulations for climate change adaptation education and engagement

    Rumore, Danya; Schenk, Todd; Susskind, Lawrence

    2016-08-01

    In order to effectively adapt to climate change, public officials and other stakeholders need to rapidly enhance their understanding of local risks and their ability to collaboratively and adaptively respond to them. We argue that science-based role-play simulation exercises -- a type of 'serious game' involving face-to-face mock decision-making -- have considerable potential as education and engagement tools for enhancing readiness to adapt. Prior research suggests role-play simulations and other serious games can foster public learning and encourage collective action in public policy-making contexts. However, the effectiveness of such exercises in the context of climate change adaptation education and engagement has heretofore been underexplored. We share results from two research projects that demonstrate the effectiveness of role-play simulations in cultivating climate change adaptation literacy, enhancing collaborative capacity and facilitating social learning. Based on our findings, we suggest such exercises should be more widely embraced as part of adaptation professionals' education and engagement toolkits.

  8. Multi-level adaptive simulation of transient two-phase flow in heterogeneous porous media

    Chueh, C.C.

    2010-10-01

    An implicit pressure and explicit saturation (IMPES) finite element method (FEM) incorporating a multi-level shock-type adaptive refinement technique is presented and applied to investigate transient two-phase flow in porous media. Local adaptive mesh refinement is implemented seamlessly with state-of-the-art artificial diffusion stabilization allowing simulations that achieve both high resolution and high accuracy. Two benchmark problems, modelling a single crack and a random porous medium, are used to demonstrate the robustness of the method and illustrate the capabilities of the adaptive refinement technique in resolving the saturation field and the complex interaction (transport phenomena) between two fluids in heterogeneous media. © 2010 Elsevier Ltd.

  9. An overview of computational simulation methods for composite structures failure and life analysis

    Chamis, Christos C.

    1993-01-01

    Three parallel computational simulation methods are being developed at the LeRC Structural Mechanics Branch (SMB) for composite structures failure and life analysis: progressive fracture CODSTRAN; hierarchical methods for high-temperature composites; and probabilistic evaluation. Results to date demonstrate that these methods are effective in simulating composite structures failure/life/reliability.

  10. Adaptability test of lettuce to soil-like substrate in bioregenerative life support system

    Min, Yan; Liu, Professor Hong; Wenting, Fu

    Plant cultivation using soil-like substrate (SLS) is considered to be a feasible option for building up matter for biological turnover in bioregenerative life support system (BLSS) by many researchers. The characteristics of SLS are different from those of true soil therefore it is very important to study the adaptability of candidate crop to SLS in BLSS. This study was carried out in three successive steps to test the adaptability of lettuce (Lactuca sativa L.) to rice straw SLS in BLSS of China. First, six Chinese specific lettuce cultivars which were selected for Chinese advanced life support system were planted into the same rice straw SLS, which was to determine the more suitable plant cultivar to do the next experiment. The results showed that Sharp Leaf lettuce and Red lettuce were more suitable for SLS than other cultivars. Second, the possibility of increasing the crop yield on the SLS was conducted by changing the soil depth and plant density. Sharp Leaf lettuce and Red lettuce were used into this experiment in order to obtain the highest yield under the smallest soil volume and weight at the same light intensity. Crop edible biomass, crop nutrition content and photosynthetic characteristics were estimated during the experiment. Red lettuce obtained higher biomass and photosynthesis capacity. Lastly, the stability of planting system of lettuce and SLS was evaluated in the closed controlled system. Red lettuce would be the test plant. In this experiment different age lettuce groups would be planted together and gas exchange would be measured. In all of these experiments soil physical and chemical characteristics were also be measured which will be the basal data for further research.

  11. Transcultural adaptation and validation of the "Adult Eosinophilic Esophagitis Quality of Life Questionnaire" into Spanish

    Alfredo J. Lucendo

    2014-06-01

    Full Text Available Background: The "Adult Eosinophilic Esophagitis Quality of Life (EoE-QoL-A Questionnaire" was developed in English as a valid, reliable, and disease-specific health-related QoL measure. This research aims to adapt and validate this questionnaire for Spanish-speaking patients. Patients and methods: A multicenter, observational, prospective study was conducted at 8 Spanish hospitals. The cultural adaptation of the original EoE-QoL-A questionnaire was undertaken through a standardized 3-phase procedure: 1. Translation; 2. Retrotranslation; and 3. Pilot study. Patients completed the Hospital Anxiety and Depression Scale (HADS, the Short Form (SF-12, the Brief Illness Perception Questionnaire (BIPQ, and the adapted EoE-QoL-A, with a retest 3 months later. Statistical analysis included construct validity, internal consistency, criterion validity, and reproducibility. Results: One hundred and seventy adult EoE patients (73.5 % male; aged 33.5 ± 11.4-y were included in the study. With regard to internal validity, all Cronbach alpha values were > 0.75. A significant correlation between items assessed in the SF-12, BIPQ and EoE-QoL-A questionnaires (p < 0.001 was observed. Correlations with the HADS were stronger for anxiety than for depression levels. Anxiety related to disease diagnosis and choking were the most affected dimensions; less affected were the dimensions related to eating, social, and emotional development. Intraclass correlation coefficients between the test and retest assessments were acceptable for all questionnaires, with the highest values (0.73-0.84 calculated for the EoE-QoL-A Spanish version. Conclusion: The Spanish version of the EoE-QoL-A is a reliable, valid, and responsive questionnaire. Diagnosis and choking anxiety were the most affected dimensions in the health-related QoL in adult EoE patients.

  12. Cosmological Shocks in Adaptive Mesh Refinement Simulations and the Acceleration of Cosmic Rays

    Skillman, Samuel W.; O'Shea, Brian W.; Hallman, Eric J.; Burns, Jack O.; Michael L. Norman

    2008-01-01

    We present new results characterizing cosmological shocks within adaptive mesh refinement N-Body/hydrodynamic simulations that are used to predict non-thermal components of large-scale structure. This represents the first study of shocks using adaptive mesh refinement. We propose a modified algorithm for finding shocks from those used on unigrid simulations that reduces the shock frequency of low Mach number shocks by a factor of ~3. We then apply our new technique to a large, (512 Mpc/h)^3, ...

  13. Battery Calendar Life Estimator Manual Modeling and Simulation

    Jon P. Christophersen; Ira Bloom; Ed Thomas; Vince Battaglia

    2012-10-01

    The Battery Life Estimator (BLE) Manual has been prepared to assist developers in their efforts to estimate the calendar life of advanced batteries for automotive applications. Testing requirements and procedures are defined by the various manuals previously published under the United States Advanced Battery Consortium (USABC). The purpose of this manual is to describe and standardize a method for estimating calendar life based on statistical models and degradation data acquired from typical USABC battery testing.

  14. Battery Life Estimator Manual Linear Modeling and Simulation

    Jon P. Christophersen; Ira Bloom; Ed Thomas; Vince Battaglia

    2009-08-01

    The Battery Life Estimator (BLE) Manual has been prepared to assist developers in their efforts to estimate the calendar life of advanced batteries for automotive applications. Testing requirements and procedures are defined by the various manuals previously published under the United States Advanced Battery Consortium (USABC). The purpose of this manual is to describe and standardize a method for estimating calendar life based on statistical models and degradation data acquired from typical USABC battery testing.

  15. QUALIMETRIC ASPECTS OF THE SOCIO-CULTURAL FACTORS OF THE ADAPTATION OF CHILDREN IN DIFFICULT LIFE SITUATIONS

    Dudkin Artem Sergeevich

    2012-01-01

    For practical realization in the social and pedagogical work, the factors of social adaptation of minors received as a result of research in certain typical difficult life situations need analytical consideration using an analytical social qualimetric approach. The levels allocated during empirical research and degree of factors of social adaptation are described with qualimetric indicators, taking into account necessary and sufficient properties. Problems of studying and realization of quant...

  16. EVENT-DRIVEN SIMULATION OF INTEGRATE-AND-FIRE MODELS WITH SPIKE-FREQUENCY ADAPTATION

    Lin Xianghong; Zhang Tianwen

    2009-01-01

    The evoked spike discharges of a neuron depend critically on the recent history of its electrical activity. A well-known example is the phenomenon of spike-frequency adaptation that is a commonly observed property of neurons. In this paper, using a leaky integrate-and-fire model that includes an adaptation current, we propose an event-driven strategy to simulate integrate-and-fire models with spike-frequency adaptation. Such approach is more precise than traditional clock-driven numerical integration approach because the timing of spikes is treated exactly. In experiments, using event-driven and clock-driven strategies we simulated the adaptation time course of single neuron and the random network with spike-timing dependent plasticity, the results indicate that (1) the temporal precision of spiking events impacts on neuronal dynamics of single as well as network in the different simulation strategies and (2) the simulation time scales linearly with the total number of spiking events in the event-driven simulation strategies.

  17. Utilized Resources of Hope, Orientation, and Inspiration in Life of Persons with Multiple Sclerosis and Their Association with Life Satisfaction, Adaptive Coping Strategies, and Spirituality.

    Wirth, Anne-Gritli; Büssing, Arndt

    2016-08-01

    In a cross-sectional survey among 213 patients with multiple sclerosis, we intended to analyze their resources of hope, orientation, and inspiration in life, and how these resources are related to health-associated variables, adaptive coping strategies, and life satisfaction. Resources were categorized as Faith (10 %), Family (22 %), Other sources (16 %), and No answer (53 %). These non-respondents were predominantly neither religious nor spiritual (70 % R-S-). Although R-S- persons are a heterogeneous group with varying existential interest, they did not significantly differ from their spiritual/religious counterparts with respect to physical and mental health or life satisfaction, but for an adaptive Reappraisal strategy and Gratitude/Awe. PMID:26169606

  18. PECULIAR FEATURES CONCERNING 1-ST-YEAR STUDENT ADAPTATION TO LIFE-ACTIVITY AT ENGINEERING HIGHER EDUCATIONAL INSTITUTION

    V. A. Klimenko

    2015-01-01

    Full Text Available The paper contains an analysis of peculiar features concerning a 1-st-year student adaptation to new conditions of life-activity  on the basis of self-evaluation made by 212 persons.  In order to obtain the data a methodology for diagnostics of social and psychological adaptation developed by K.Rodgers and R.Diamond has been applied with the purpose to study such integral indices as adaptivity, emotional comfort, friendly attitude, internality, tolerance and domination symptom.

  19. The conquest of freshwater and land by marine crabs: adaptations in life-history patterns and larval bioenergetics

    Anger, Klaus

    1995-01-01

    Life-history patterns in marine, limnic, and terrestrial brachyurans are reviewed to discern special adaptations associated with transitions in life style. Among marine crabs, the Grapsidae have been especially successful invading freshwater and terrestrial environments, in particular a group of closely related neotropical Sesarminae species, which has evolved through a conspicuous radiation process. Compared with marine grapsid crabs, freshwater and terrestrial species show the following ten...

  20. Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator

    Cari Pérez-Vives; César Albarrán-Diego; Santiago García-Lázaro; Teresa Ferrer-Blasco; Robert Montés-Micó

    2014-01-01

    Purpose: To compare optical and visual quality of implantable collamer lens (ICL) implantation and femtosecond laser in situ keratomileusis (F-LASIK) for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France) was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D) and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd) were measured for 3-mm an...

  1. Dynamically adaptive Lattice Boltzmann simulation of shallow water flows with the Peano framework

    Neumann, Philipp

    2015-09-01

    © 2014 Elsevier Inc. All rights reserved. We present a dynamically adaptive Lattice Boltzmann (LB) implementation for solving the shallow water equations (SWEs). Our implementation extends an existing LB component of the Peano framework. We revise the modular design with respect to the incorporation of new simulation aspects and LB models. The basic SWE-LB implementation is validated in different breaking dam scenarios. We further provide a numerical study on stability of the MRT collision operator used in our simulations.

  2. The Self-Adaptive Fuzzy PID Controller in Actuator Simulated Loading System

    Chuanhui Zhang; Xiaodong Song

    2013-01-01

    This paper analyzes the structure principle of the actuator simulated loading system with variable stiffness, and establishes the simplified model. What’s more, it also does a research on the application of the self-adaptive tuning of fuzzy PID(Proportion Integration Differentiation) in actuator simulated loading system with variable stiffness. Because the loading system is connected with the steering system by a spring rod, there must be strong coupling. Besides, there are also the parametri...

  3. The Self-Adaptive Fuzzy PID Controller in Actuator Simulated Loading System

    Chuanhui Zhang

    2013-05-01

    Full Text Available This paper analyzes the structure principle of the actuator simulated loading system with variable stiffness, and establishes the simplified model. What’s more, it also does a research on the application of the self-adaptive tuning of fuzzy PID(Proportion Integration Differentiation in actuator simulated loading system with variable stiffness. Because the loading system is connected with the steering system by a spring rod, there must be strong coupling. Besides, there are also the parametric variations accompanying with the variations of the stiffness. Based on compensation from the feed-forward control on the disturbance brought by the motion of steering engine, the system performance can be improved by using fuzzy adaptive adjusting PID control to make up the changes of system parameter caused by the changes of the stiffness. By combining the fuzzy control with traditional PID control, fuzzy adaptive PID control is able to choose the parameters more properly.

  4. Simulation Research on Adaptive Control of a Six-degree-of-freedom Material-testing Machine

    Dan Wang

    2014-02-01

    Full Text Available This paper presents an adaptive controller equipped with a stiffness estimation method for a novel material-testing machine, in order to alleviate the performance depression caused by the stiffness variance of the tested specimen. The dynamic model of the proposed machine is built using the Kane method, and the kinematic model is established with a closed-form solution. The stiffness estimation method is developed based on the recursive least-squares method and the proposed stiffness equivalent matrix. Control performances of the adaptive controller are simulated in detail. The simulation results illustrate that the proposed controller can greatly improve the control performance of the target material-testing machine by online stiffness estimation and adaptive parameter tuning, especially in low-cycle fatigue (LCF and high-cycle fatigue (HCF tests.

  5. Adaptive finite element method assisted by stochastic simulation of chemical systems

    Cotter, S.L.; Vejchodský, Tomáš; Erban, R.

    2013-01-01

    Roč. 35, č. 1 (2013), B107-B131. ISSN 1064-8275 R&D Projects: GA AV ČR(CZ) IAA100190803 Institutional support: RVO:67985840 Keywords : chemical Fokker-Planck * adaptive meshes * stochastic simulation algorithm Subject RIV: BA - General Mathematics Impact factor: 1.940, year: 2013 http://epubs.siam.org/doi/abs/10.1137/120877374

  6. 3D Simulation of Flow with Free Surface Based on Adaptive Octree Mesh System

    Li Shaowu; Zhuang Qian; Huang Xiaoyun; Wang Dong

    2015-01-01

    The technique of adaptive tree mesh is an effective way to reduce computational cost through automatic adjustment of cell size according to necessity. In the present study, the 2D numerical N-S solver based on the adaptive quadtree mesh system was extended to a 3D one, in which a spatially adaptive octree mesh system and multiple parti-cle level set method were adopted for the convenience to deal with the air-water-structure multiple-medium coexisting domain. The stretching process of a dumbbell was simulated and the results indicate that the meshes are well adaptable to the free surface. The collapsing process of water column impinging a circle cylinder was simulated and from the results, it can be seen that the processes of fluid splitting and merging are properly simulated. The interaction of sec-ond-order Stokes waves with a square cylinder was simulated and the obtained drag force is consistent with the result by the Morison’s wave force formula with the coefficient values of the stable drag component and the inertial force component being set as 2.54.

  7. Simulation and Performance Analysis of Adaptive Filtering Algorithms in Noise Cancellation

    Ferdouse, Lilatul; Nipa, Tamanna Haque; Jaigirdar, Fariha Tasmin

    2011-01-01

    Noise problems in signals have gained huge attention due to the need of noise-free output signal in numerous communication systems. The principal of adaptive noise cancellation is to acquire an estimation of the unwanted interfering signal and subtract it from the corrupted signal. Noise cancellation operation is controlled adaptively with the target of achieving improved signal to noise ratio. This paper concentrates upon the analysis of adaptive noise canceller using Recursive Least Square (RLS), Fast Transversal Recursive Least Square (FTRLS) and Gradient Adaptive Lattice (GAL) algorithms. The performance analysis of the algorithms is done based on convergence behavior, convergence time, correlation coefficients and signal to noise ratio. After comparing all the simulated results we observed that GAL performs the best in noise cancellation in terms of Correlation Coefficient, SNR and Convergence Time. RLS, FTRLS and GAL were never evaluated and compared before on their performance in noise cancellation in ...

  8. Adaptive Wavelet Collocation Method for Simulation of Time Dependent Maxwell's Equations

    Li, Haojun; Rieder, Andreas; Freude, Wolfgang

    2012-01-01

    This paper investigates an adaptive wavelet collocation time domain method for the numerical solution of Maxwell's equations. In this method a computational grid is dynamically adapted at each time step by using the wavelet decomposition of the field at that time instant. In the regions where the fields are highly localized, the method assigns more grid points; and in the regions where the fields are sparse, there will be less grid points. On the adapted grid, update schemes with high spatial order and explicit time stepping are formulated. The method has high compression rate, which substantially reduces the computational cost allowing efficient use of computational resources. This adaptive wavelet collocation method is especially suitable for simulation of guided-wave optical devices.

  9. Simulation Study of Swarm Intelligence Based on Life Evolution Behavior

    Yanmin Liu; Ying Bi; Changling Sui; Yuanfeng Luo; Zhuanzhou Zhang; Rui Liu

    2015-01-01

    Swarm intelligence (SI) is a new evolutionary computation technology, and its performance efficacy is usually affected by each individual behavior in the swarm. According to the genetic and sociological theory, the life evolution behavior process is influenced by the external and internal factors, so the mechanisms of external and internal environment change must be analyzed and explored. Therefore, in this paper, we used the thought of the famous American genetic biologist Morgan, “life = DN...

  10. The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves.

    Stahler, Daniel R; MacNulty, Daniel R; Wayne, Robert K; vonHoldt, Bridgett; Smith, Douglas W

    2013-01-01

    Reproduction in social organisms is shaped by numerous morphological, behavioural and life-history traits such as body size, cooperative breeding and age of reproduction, respectively. Little is known, however, about the relative influence of these different types of traits on reproduction, particularly in the context of environmental conditions that determine their adaptive value. Here, we use 14 years of data from a long-term study of wolves (Canis lupus) in Yellowstone National Park, USA, to evaluate the relative effects of different traits and ecological factors on the reproductive performance (litter size and survival) of breeding females. At the individual level, litter size and survival improved with body mass and declined with age (c. 4-5 years). Grey-coloured females had more surviving pups than black females, which likely contributed to the maintenance of coat colour polymorphism in this system. The effect of pack size on reproductive performance was nonlinear as litter size peaked at eight wolves and then declined, and litter survival increased rapidly up to three wolves, beyond which it increased more gradually. At the population level, litter size and survival decreased with increasing wolf population size and canine distemper outbreaks. The relative influence of these different-level factors on wolf reproductive success followed individual > group > population. Body mass was the primary determinant of litter size, followed by pack size and population size. Body mass was also the main driver of litter survival, followed by pack size and disease. Reproductive gains because of larger body size and cooperative breeding may mitigate reproductive losses because of negative density dependence and disease. These findings highlight the adaptive value of large body size and sociality in promoting individual fitness in stochastic and competitive environments. PMID:23043440

  11. Quantum Simulations of Nuclei and Nuclear Pasta with the Multi-resolution Adaptive Numerical Environment for Scientific Simulations

    Sagert, I; Fattoyev, F J; Postnikov, S; Horowitz, C J

    2015-01-01

    Neutron star and supernova matter at densities just below the nuclear matter saturation density is expected to form a lattice of exotic shapes. These so-called nuclear pasta phases are caused by Coulomb frustration. Their elastic and transport properties are believed to play an important role for thermal and magnetic field evolution, rotation and oscillation of neutron stars. Furthermore, they can impact neutrino opacities in core-collapse supernovae. In this work, we present proof-of-principle 3D Skyrme Hartree-Fock (SHF) simulations of nuclear pasta with the Multi-resolution ADaptive Numerical Environment for Scientific Simulations (MADNESS). We perform benchmark studies of $^{16} \\mathrm{O}$, $^{208} \\mathrm{Pb}$ and $^{238} \\mathrm{U}$ nuclear ground states and calculate binding energies via 3D SHF simulations. Results are compared with experimentally measured binding energies as well as with theoretically predicted values from an established SHF code. The nuclear pasta simulation is initialized in the so...

  12. The Development of an ICF-Oriented, Adaptive Physician Assessment Instrument of Mobility, Self-care, and Domestic Life

    Farin, Erik; Fleitz, Annette

    2009-01-01

    The objective of this study was development and psychometric testing of an adaptive, International Classification of Functioning, Disability, and Health (ICF)-oriented questionnaire to be processed by the rehabilitation physician that aids in assessing mobility, self-care, and domestic life (Moses-Physician). The intent is to develop a physician…

  13. Social Support, Conflict, Major Life Stressors, and Adaptive Coping Strategies in Latino Middle School Students: An Integrative Model

    Crean, Hugh F.

    2004-01-01

    Structural equation modeling techniques were used to test a conceptual framework for improved understanding of the relationships involved in adolescent risk and protective factors. Specifically, the model examined the direct and indirect associations, via adaptive coping strategies, that acute life stressors and contextual support and conflict…

  14. Using Structural Equation Modeling to Validate Online Game Players' Motivations Relative to Self-Concept and Life Adaptation

    Yang, Shu Ching; Huang, Chiao Ling

    2013-01-01

    This study aimed to validate a systematic instrument to measure online players' motivations for playing online games (MPOG) and examine how the interplay of differential motivations impacts young gamers' self-concept and life adaptation. Confirmatory factor analysis determined that a hierarchical model with a two-factor structure of…

  15. Parallel Adaptive Simulation of Detonation Waves Using a Weighted Essentially Non-Oscillatory Scheme

    McMahon, Sean

    The purpose of this thesis was to develop a code that could be used to develop a better understanding of the physics of detonation waves. First, a detonation was simulated in one dimension using ZND theory. Then, using the 1D solution as an initial condition, a detonation was simulated in two dimensions using a weighted essentially non-oscillatory scheme on an adaptive mesh with the smallest lengthscales being equal to 2-3 flamelet lengths. The code development in linking Chemkin for chemical kinetics to the adaptive mesh refinement flow solver was completed. The detonation evolved in a way that, qualitatively, matched the experimental observations, however, the simulation was unable to progress past the formation of the triple point.

  16. High-Performance Reactive Fluid Flow Simulations Using Adaptive Mesh Refinement on Thousands of Processors

    Calder, A. C.; Curtis, B. C.; Dursi, L. J.; Fryxell, B.; Henry, G.; MacNeice, P.; Olson, K.; Ricker, P.; Rosner, R.; Timmes, F. X.; Tufo, H. M.; Truran, J. W.; Zingale, M.

    We present simulations and performance results of nuclear burning fronts in supernovae on the largest domain and at the finest spatial resolution studied to date. These simulations were performed on the Intel ASCI-Red machine at Sandia National Laboratories using FLASH, a code developed at the Center for Astrophysical Thermonuclear Flashes at the University of Chicago. FLASH is a modular, adaptive mesh, parallel simulation code capable of handling compressible, reactive fluid flows in astrophysical environments. FLASH is written primarily in Fortran 90, uses the Message-Passing Interface library for inter-processor communication and portability, and employs the PARAMESH package to manage a block-structured adaptive mesh that places blocks only where the resolution is required and tracks rapidly changing flow features, such as detonation fronts, with ease. We describe the key algorithms and their implementation as well as the optimizations required to achieve sustained performance of 238 GLOPS on 6420 processors of ASCI-Red in 64-bit arithmetic.

  17. Adaptive grids and numerical fluid simulations for scrape-off layer plasmas

    Magnetic confinement nuclear fusion experiments create plasmas with local temperatures in excess of 100 million Kelvin. In these experiments the scrape-off layer, which is the plasma region in direct contact with the device wall, is of central importance both for the quality of the energy confinement and the wall material lifetime. To study the behaviour of the scrape-off layer, in addition to experiments, numerical simulations are used. This work investigates the use of adaptive discretizations of space and compatible numerical methods for scrape-off layer simulations. The resulting algorithms allow dynamic adaptation of computational grids aligned to the magnetic fields to precisely capture the strongly anisotropic energy and particle transport in the plasma. The methods are applied to the multi-fluid plasma code B2, with the goal of reducing the runtime of simulations and extending the applicability of the code.

  18. Availability simulation software adaptation to the IFMIF accelerator facility RAMI analyses

    Highlights: • The reason why IFMIF RAMI analyses needs a simulation is explained. • Changes, modifications and software validations done to AvailSim are described. • First IFMIF RAMI results obtained with AvailSim 2.0 are shown. • Implications of AvailSim 2.0 in IFMIF RAMI analyses are evaluated. - Abstract: Several problems were found when using generic reliability tools to perform RAMI (Reliability Availability Maintainability Inspectability) studies for the IFMIF (International Fusion Materials Irradiation Facility) accelerator. A dedicated simulation tool was necessary to model properly the complexity of the accelerator facility. AvailSim, the availability simulation software used for the International Linear Collider (ILC) became an excellent option to fulfill RAMI analyses needs. Nevertheless, this software needed to be adapted and modified to simulate the IFMIF accelerator facility in a useful way for the RAMI analyses in the current design phase. Furthermore, some improvements and new features have been added to the software. This software has become a great tool to simulate the peculiarities of the IFMIF accelerator facility allowing obtaining a realistic availability simulation. Degraded operation simulation and maintenance strategies are the main relevant features. In this paper, the necessity of this software, main modifications to improve it and its adaptation to IFMIF RAMI analysis are described. Moreover, first results obtained with AvailSim 2.0 and a comparison with previous results is shown

  19. A well-balanced numerical scheme for shallow water simulation on adaptive grids

    The efficiency of solving two-dimensional shallow-water equations (SWEs) is vital for simulation of large-scale flood inundation. For flood flows over real topography, local high-resolution method, which uses adaptable grids, is required in order to prevent the loss of accuracy of the flow pattern while saving computational cost. This paper introduces an adaptive grid model, which uses an adaptive criterion calculated on the basis of the water lever. The grid adaption is performed by manipulating subdivision levels of the computation grids. As the flow feature varies during the shallow wave propagation, the local grid density changes adaptively and the stored information of neighbor relationship updates correspondingly, achieving a balance between the model accuracy and running efficiency. In this work, a well-balanced (WB) scheme for solving SWEs is introduced. In reconstructions of Riemann state, the definition of the unique bottom elevation on grid interfaces is modified, and the numerical scheme is pre-balanced automatically. By the validation against two idealist test cases, the proposed model is applied to simulate flood inundation due to a dam-break of Zhanghe Reservoir, Hubei province, China. The results show that the presented model is robust and well-balanced, has nice computational efficiency and numerical stability, and thus has bright application prospects.

  20. [Cross-cultural adaptation of LIFE-H 3.1: an instrument for assessing social participation].

    Assumpção, Fernanda Sabine Nunes de; Faria-Fortini, Iza de; Basílio, Marluce Lopes; Magalhães, Lívia de Castro; Carvalho, Augusto Cesinando de; Teixeira-Salmela, Luci Fuscaldi

    2016-06-20

    Restrictions in participation cause serious problems for individuals with chronic disabling conditions. The use of questionnaires to assess participation allows studying the impact of such chronic conditions on functionality, besides potentially improving intervention strategies. The aim of this study was to translate the Assessment of Life Habits (LIFE-H 3.1) into Brazilian Portuguese language and adapt the questionnaire to the Brazilian culture. The cross-cultural adaptation followed standard guidelines and was conducted in five stages: translation, back-translation, summary of the translations, expert committee consultation, and testing the pre-final version. The final version of the LIFE-H 3.1 for use in Brazil showed satisfactory semantic, linguistic, cultural, and conceptual equivalence. Future studies should continue the process of validating the questionnaire. PMID:27333131

  1. Adaptive finite element simulation of flow and transport applications on parallel computers

    Kirk, Benjamin Shelton

    The subject of this work is the adaptive finite element simulation of problems arising in flow and transport applications on parallel computers. Of particular interest are new contributions to adaptive mesh refinement (AMR) in this parallel high-performance context, including novel work on data structures, treatment of constraints in a parallel setting, generality and extensibility via object-oriented programming, and the design/implementation of a flexible software framework. This technology and software capability then enables more robust, reliable treatment of multiscale--multiphysics problems and specific studies of fine scale interaction such as those in biological chemotaxis (Chapter 4) and high-speed shock physics for compressible flows (Chapter 5). The work begins by presenting an overview of key concepts and data structures employed in AMR simulations. Of particular interest is how these concepts are applied in the physics-independent software framework which is developed here and is the basis for all the numerical simulations performed in this work. This open-source software framework has been adopted by a number of researchers in the U.S. and abroad for use in a wide range of applications. The dynamic nature of adaptive simulations pose particular issues for efficient implementation on distributed-memory parallel architectures. Communication cost, computational load balance, and memory requirements must all be considered when developing adaptive software for this class of machines. Specific extensions to the adaptive data structures to enable implementation on parallel computers is therefore considered in detail. The libMesh framework for performing adaptive finite element simulations on parallel computers is developed to provide a concrete implementation of the above ideas. This physics-independent framework is applied to two distinct flow and transport applications classes in the subsequent application studies to illustrate the flexibility of the

  2. Modeling and simulating the adaptive electrical properties of stochastic polymeric 3D networks

    Memristors are passive two-terminal circuit elements that combine resistance and memory. Although in theory memristors are a very promising approach to fabricate hardware with adaptive properties, there are only very few implementations able to show their basic properties. We recently developed stochastic polymeric matrices with a functionality that evidences the formation of self-assembled three-dimensional (3D) networks of memristors. We demonstrated that those networks show the typical hysteretic behavior observed in the ‘one input-one output’ memristive configuration. Interestingly, using different protocols to electrically stimulate the networks, we also observed that their adaptive properties are similar to those present in the nervous system. Here, we model and simulate the electrical properties of these self-assembled polymeric networks of memristors, the topology of which is defined stochastically. First, we show that the model recreates the hysteretic behavior observed in the real experiments. Second, we demonstrate that the networks modeled indeed have a 3D instead of a planar functionality. Finally, we show that the adaptive properties of the networks depend on their connectivity pattern. Our model was able to replicate fundamental qualitative behavior of the real organic 3D memristor networks; yet, through the simulations, we also explored other interesting properties, such as the relation between connectivity patterns and adaptive properties. Our model and simulations represent an interesting tool to understand the very complex behavior of self-assembled memristor networks, which can finally help to predict and formulate hypotheses for future experiments. (paper)

  3. Is life-history buffering or lability adaptive in stochastic environments?

    Koons, David N.; Pavard, Samuel; Baudisch, Annette;

    2009-01-01

    It is commonly thought that temporal fluctuations in demographic parameters should be selected against because of the deleterious impacts variation can have on fitness. A critical underpinning of this prediction is the assumption that changes in environmental conditions map linearly into changes ...... review previous ecological work, and indicate cases where 'demographic lability' may be adaptive, then conclude by identifying research that is needed to develop a theory of life-history evolution that encompasses both demographic buffering and lability. © 2009 Oikos.......It is commonly thought that temporal fluctuations in demographic parameters should be selected against because of the deleterious impacts variation can have on fitness. A critical underpinning of this prediction is the assumption that changes in environmental conditions map linearly into changes in...... demographic parameters over time. We detail why this assumption may often break down and why selection should not always favor buffering of demographic parameters against environmental stochasticity. To the contrary, nonlinear relationships between the environment and demographic performance can produce...

  4. Adapting the serial Alpgen event generator to simulate LHC collisions on millions of parallel threads

    Childers, J T; LeCompte, T J; Papka, M E; Benjamin, D P

    2015-01-01

    As the LHC moves to higher energies and luminosity, the demand for computing resources increases accordingly and will soon outpace the growth of the Worldwide LHC Computing Grid. To meet this greater demand, event generation Monte Carlo was targeted for adaptation to run on Mira, the supercomputer at the Argonne Leadership Computing Facility. Alpgen is a Monte Carlo event generation application that is used by LHC experiments in the simulation of collisions that take place in the Large Hadron Collider. This paper details the process by which Alpgen was adapted from a single-processor serial-application to a large-scale parallel-application and the performance that was achieved.

  5. Spatially adaptive radiation-hydrodynamical simulations of galaxy formation during cosmological reionization

    Pawlik, Andreas H; Vecchia, Claudio Dalla

    2015-01-01

    We present a suite of cosmological radiation-hydrodynamical simulations of the assembly of galaxies driving the reionization of the intergalactic medium (IGM) at z >~ 6. The simulations account for the hydrodynamical feedback from photoionization heating and the explosion of massive stars as supernovae (SNe). Our reference simulation, which was carried out in a box of size 25 comoving Mpc/h using 2 x 512^3 particles, produces a reasonable reionization history and matches the observed UV luminosity function of galaxies. Simulations with different box sizes and resolutions are used to investigate numerical convergence, and simulations in which either SNe or photoionization heating or both are turned off, are used to investigate the role of feedback from star formation. Ionizing radiation is treated using accurate radiative transfer at the high spatially adaptive resolution at which the hydrodynamics is carried out. SN feedback strongly reduces the star formation rates (SFRs) over nearly the full mass range of s...

  6. Reinforcement learning for adaptive threshold control of restorative brain-computer interfaces: a Bayesian simulation

    Robert eBauer

    2015-02-01

    Full Text Available Restorative brain-computer interfaces (BCI are increasingly used to provide feedback of neuronal states in a bid to normalize pathological brain activity and achieve behavioral gains. However, patients and healthy subjects alike often show a large variability, or even inability, of brain self-regulation for BCI control, known as BCI illiteracy. Although current co-adaptive algorithms are powerful for assistive BCIs, their inherent class switching clashes with the operant conditioning goal of restorative BCIs. Moreover, due to the treatment rationale, the classifier of restorative BCIs usually has a constrained feature space, thus limiting the possibility of classifier adaptation.In this context, we applied a Bayesian model of neurofeedback and reinforcement learning for different threshold selection strategies to study the impact of threshold adaptation of a linear classifier on optimizing restorative BCIs. For each feedback iteration, we first determined the thresholds that result in minimal action entropy and maximal instructional efficiency. We then used the resulting vector for the simulation of continuous threshold adaptation. We could thus show that threshold adaptation can improve reinforcement learning, particularly in cases of BCI illiteracy. Finally, on the basis of information-theory, we provided an explanation for the achieved benefits of adaptive threshold setting.

  7. Adapt

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  8. On the adaptations to cave life of some different animal groups (first note

    Emilian Pricop

    2009-12-01

    Full Text Available In this paper we present the major and common adaptations to the cave environment ofdifferent animal groups. The common features are: anophthalmia, depigmentation, apterism in the caseof insects, body shape and ecophysiological adaptations.

  9. Parameter estimation for chaotic systems using a hybrid adaptive cuckoo search with simulated annealing algorithm

    Sheng, Zheng, E-mail: 19994035@sina.com [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101 (China); Wang, Jun; Zhou, Bihua [National Defense Key Laboratory on Lightning Protection and Electromagnetic Camouflage, PLA University of Science and Technology, Nanjing 210007 (China); Zhou, Shudao [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing 211101 (China); Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing 210044 (China)

    2014-03-15

    This paper introduces a novel hybrid optimization algorithm to establish the parameters of chaotic systems. In order to deal with the weaknesses of the traditional cuckoo search algorithm, the proposed adaptive cuckoo search with simulated annealing algorithm is presented, which incorporates the adaptive parameters adjusting operation and the simulated annealing operation in the cuckoo search algorithm. Normally, the parameters of the cuckoo search algorithm are kept constant that may result in decreasing the efficiency of the algorithm. For the purpose of balancing and enhancing the accuracy and convergence rate of the cuckoo search algorithm, the adaptive operation is presented to tune the parameters properly. Besides, the local search capability of cuckoo search algorithm is relatively weak that may decrease the quality of optimization. So the simulated annealing operation is merged into the cuckoo search algorithm to enhance the local search ability and improve the accuracy and reliability of the results. The functionality of the proposed hybrid algorithm is investigated through the Lorenz chaotic system under the noiseless and noise condition, respectively. The numerical results demonstrate that the method can estimate parameters efficiently and accurately in the noiseless and noise condition. Finally, the results are compared with the traditional cuckoo search algorithm, genetic algorithm, and particle swarm optimization algorithm. Simulation results demonstrate the effectiveness and superior performance of the proposed algorithm.

  10. Simulation of Old Urban Residential Area Evolution Based on Complex Adaptive System

    YANG Fan; WANG Xiao-ming; HUA Hong

    2009-01-01

    On the basis of complex adaptive system theory,this paper proposed an agent-based model of old urban residential area,in which,residents and providers are the two adaptive agents.The behaviors of residents and providers in this model are trained with back propagation and simulated with Swarm software based on environment-rules-agents interaction.This model simulates the evolution of old urban residential area and analyzes the relations between the evolution and urban management with the background of Chaozhou city.As a result,the following are obtained:(1) Simulation without government intervention indicates the trend of housing ageing,environmental deterioration,economic depression,and social filtering-down in old urban residential area.If the development of old urban residential area is under control of developers in market,whose desire is profit maximization,and factors such as social justice,historic and culture value will be ignored.(2) If the government carries out some policies and measures which will perfectly serve their original aims,simulation reveals that old urban residential area could be adapted to environment and keep sustainable development.This conclusion emphasizes that government must act as initiator and program maker for guiding residents and other providers directly in the development of old urban residential area.

  11. Parameter estimation for chaotic systems using a hybrid adaptive cuckoo search with simulated annealing algorithm

    Sheng, Zheng; Wang, Jun; Zhou, Shudao; Zhou, Bihua

    2014-03-01

    This paper introduces a novel hybrid optimization algorithm to establish the parameters of chaotic systems. In order to deal with the weaknesses of the traditional cuckoo search algorithm, the proposed adaptive cuckoo search with simulated annealing algorithm is presented, which incorporates the adaptive parameters adjusting operation and the simulated annealing operation in the cuckoo search algorithm. Normally, the parameters of the cuckoo search algorithm are kept constant that may result in decreasing the efficiency of the algorithm. For the purpose of balancing and enhancing the accuracy and convergence rate of the cuckoo search algorithm, the adaptive operation is presented to tune the parameters properly. Besides, the local search capability of cuckoo search algorithm is relatively weak that may decrease the quality of optimization. So the simulated annealing operation is merged into the cuckoo search algorithm to enhance the local search ability and improve the accuracy and reliability of the results. The functionality of the proposed hybrid algorithm is investigated through the Lorenz chaotic system under the noiseless and noise condition, respectively. The numerical results demonstrate that the method can estimate parameters efficiently and accurately in the noiseless and noise condition. Finally, the results are compared with the traditional cuckoo search algorithm, genetic algorithm, and particle swarm optimization algorithm. Simulation results demonstrate the effectiveness and superior performance of the proposed algorithm.

  12. Adaptive style and differences in parent and child report of health-related quality of life in children with cancer.

    Jurbergs, Nichole; Russell, Kathryn M W; Long, Alanna; Phipps, Sean

    2008-01-01

    The objective of this study was to examine the self-reported health-related quality of life (HRQL) of children with cancer, and the consistency between child and parent reports of child HRQL, as a function of the child's adaptive style. Participants included 199 children with cancer, 108 healthy children, and their parents. Children completed self-report measures of HRQL and adaptive style. Measures of adaptive style were used to categorize children as high anxious, low anxious, defensive high anxious or repressor. Parents completed measures reporting their children's HRQL. Adaptive style was a significant predictor of child-reported HRQL, particularly on the psychosocial scales, with children identified as repressors reporting the best HRQL. Adaptive style was also predictive of discrepancies between parent and child report of child HRQL. Repressor and low anxious children reported better HRQL than did their parents, while high anxious children reported poorer HRQL, regardless of health status. Adaptive style is a significant determinant of self-reported HRQL in children, particularly in psychosocial domains, while health status (i.e. cancer patient vs healthy control) is predictive only of physical health domains. Researchers and clinicians should be aware of the impact of child adaptive style when assessing HRQL outcomes using self- or parent report. PMID:17410520

  13. Level-by-level artificial viscosity and visualization for MHD simulation with adaptive mesh refinement

    Hatori, Tomoharu; Ito, Atsushi M.; Nunami, Masanori; Usui, Hideyuki; Miura, Hideaki

    2016-08-01

    We propose a numerical method to determine the artificial viscosity in magnetohydrodynamics (MHD) simulations with adaptive mesh refinement (AMR) method, where the artificial viscosity is adaptively changed due to the resolution level of the AMR hierarchy. Although the suitable value of the artificial viscosity depends on the governing equations and the model of target problem, it can be determined by von Neumann stability analysis. By means of the new method, "level-by-level artificial viscosity method," MHD simulations of Rayleigh-Taylor instability (RTI) are carried out with the AMR method. The validity of the level-by-level artificial viscosity method is confirmed by the comparison of the linear growth rates of RTI between the AMR simulations and the simple simulations with uniform grid and uniform artificial viscosity whose resolution is the same as that in the highest level of the AMR simulation. Moreover, in the nonlinear phase of RTI, the secondary instability is clearly observed where the hierarchical data structure of AMR calculation is visualized as high resolution region floats up like terraced fields. In the applications of the method to general fluid simulations, the growth of small structures can be sufficiently reproduced, while the divergence of numerical solutions can be suppressed.

  14. Bringing Reality into Calculus Classrooms: Mathematizing a Real-life Problem Simulated in a Virtual Environment

    Olga V. Shipulina

    2013-01-01

    Full Text Available The study explores how students, who had completed the AP calculus course, mathematized the optimal navigation real-life problem simulated in the Second Life Virtual Environment. The particular research interest was to investigate whether/how students’ empirical activity in VE influences the way of their mathematizing.

  15. Validation Through Simulations of a Cn2 Profiler for the ESO/VLT Adaptive Optics Facility

    Garcia-Rissmann, A; Kolb, J; Louarn, M Le; Madec, P -Y; Neichel, B

    2015-01-01

    The Adaptive Optics Facility (AOF) project envisages transforming one of the VLT units into an adaptive telescope and providing its ESO (European Southern Observatory) second generation instruments with turbulence corrected wavefronts. For MUSE and HAWK-I this correction will be achieved through the GALACSI and GRAAL AO modules working in conjunction with a 1170 actuators Deformable Secondary Mirror (DSM) and the new Laser Guide Star Facility (4LGSF). Multiple wavefront sensors will enable GLAO and LTAO capabilities, whose performance can greatly benefit from a knowledge about the stratification of the turbulence in the atmosphere. This work, totally based on end-to-end simulations, describes the validation tests conducted on a Cn2 profiler adapted for the AOF specifications. Because an absolute profile calibration is strongly dependent on a reliable knowledge of turbulence parameters r0 and L0, the tests presented here refer only to normalized output profiles. Uncertainties in the input parameters inherent t...

  16. Radiation Hydrodynamics using Characteristics on Adaptive Decomposed Domains for Massively Parallel Star Formation Simulations

    Buntemeyer, Lars; Peters, Thomas; Klassen, Mikhail; Pudritz, Ralph E

    2015-01-01

    We present an algorithm for solving the radiative transfer problem on massively parallel computers using adaptive mesh refinement and domain decomposition. The solver is based on the method of characteristics which requires an adaptive raytracer that integrates the equation of radiative transfer. The radiation field is split into local and global components which are handled separately to overcome the non-locality problem. The solver is implemented in the framework of the magneto-hydrodynamics code FLASH and is coupled by an operator splitting step. The goal is the study of radiation in the context of star formation simulations with a focus on early disc formation and evolution. This requires a proper treatment of radiation physics that covers both the optically thin as well as the optically thick regimes and the transition region in particular. We successfully show the accuracy and feasibility of our method in a series of standard radiative transfer problems and two 3D collapse simulations resembling the ear...

  17. AN ADAPTIVE EFG-FE COUPLING METHOD FOR THE NUMERICAL SIMULATION OF EXTRUSION PROCESSES

    L.C.Liu; X.H.Dong; C.X.Li

    2008-01-01

    An adaptive EFG-FE coupling method is proposed and developed for the numerical simulation of lateral extrusion and forward-backward extrusion. Initially, the simulation has been implemented by using a conventional FE model. During the deforming process, mesh quality is checked at every incremental step. Distorted elements are automatically converted to EFG nodes, whereas, the less distorted elements are reserved. A new algorithm to generate EFG nodes and interface elements is presented. This method is capable of dealing with large deformation and has higher computational efficiency than using an EFG method wholly. Numerical results demonstrate that the adaptive EFG-FE coupling method has reasonable accuracy and is effective for local bulk metal forming such as extrusion processes.

  18. Wavelet-based adaptive numerical simulation of unsteady 3D flow around a bluff body

    de Stefano, Giuliano; Vasilyev, Oleg

    2012-11-01

    The unsteady three-dimensional flow past a two-dimensional bluff body is numerically simulated using a wavelet-based method. The body is modeled by exploiting the Brinkman volume-penalization method, which results in modifying the governing equations with the addition of an appropriate forcing term inside the spatial region occupied by the obstacle. The volume-penalized incompressible Navier-Stokes equations are numerically solved by means of the adaptive wavelet collocation method, where the non-uniform spatial grid is dynamically adapted to the flow evolution. The combined approach is successfully applied to the simulation of vortex shedding flow behind a stationary prism with square cross-section. The computation is conducted at transitional Reynolds numbers, where fundamental unstable three-dimensional vortical structures exist, by well-predicting the unsteady forces arising from fluid-structure interaction.

  19. Unstructured Adaptive Grid Flow Simulations of Inert and Reactive Gas Mixtures

    Figueira da Silva, L. F.; Azevedo, João L. F.; Korzenowski, Heidi

    2000-05-01

    Unstructured adaptive grid flow simulation is applied to the calculation of high-speed compressible flows of inert and reactive gas mixtures. In the present case, the flowfield is simulated using the 2-D Euler equations, which are discretized in a cell-centered finite volume procedure on unstructured triangular meshes. Interface fluxes are calculated by a Liou flux vector splitting scheme which has been adapted to an unstructured grid context by the authors. Physicochemical properties are functions of the local mixture composition, temperature, and pressure, which are computed using the CHEMKIN-II subroutines. Computational results are presented for the case of premixed hydrogen-air supersonic flow over a 2-D wedge. In such a configuration, combustion may be triggered behind the oblique shock wave and transition to an oblique detonation wave is eventually obtained. It is shown that the solution adaptive procedure implemented is able to correctly define the important wave fronts. A parametric analysis of the influence of the adaptation parameters on the computed solution is performed.

  20. Multi-GPU adaptation of a simulator of heart electric activity

    Víctor M. García

    2013-12-01

    Full Text Available The simulation of the electrical activity of the heart is calculated by solving a large system of ordinary differential equations; this takes an enormous amount of computation time. In recent years graphics processing unit (GPU are being introduced in the field of high performance computing. These powerful computing devices have attracted research groups requiring simulate the electrical activity of the heart. The research group signing this paper has developed a simulator of cardiac electrical activity that runs on a single GPU. This article describes the adaptation and modification of the simulator to run on multiple GPU. The results confirm that the technique significantly reduces the execution time compared to those obtained with a single GPU, and allows the solution of larger problems.

  1. Harmonic amplitude-phase adaptive control and its application in three-axis simulators

    ZHANG Yuan-sheng; YANG Yi-dong

    2005-01-01

    This paper proposes a compensation method for using the Harmonic Amplitude-Phase Adaptive Control(HAPAC) to increase the precision of sinusoidal motion simulators. It also expounds on the HAPAC principle and structural disposition, develops the HAPAC control laws and analyzes the system stability in the HAPAC. A nethod for further improving the precision using online identification of the system' s frequency-response models is presented. The tested data and tracking errors of the simulator demonstrate that the HAPAC makes the sinusoidal motions achieve higher precision than the common classical controls. The HAPAC can also be used in other tracking systems of precision sinusoidal motions.

  2. Validation of a computer-adaptive test to evaluate generic health-related quality of life

    Zardaín Pilar C

    2010-12-01

    Full Text Available Abstract Background Health Related Quality of Life (HRQoL is a relevant variable in the evaluation of health outcomes. Questionnaires based on Classical Test Theory typically require a large number of items to evaluate HRQoL. Computer Adaptive Testing (CAT can be used to reduce tests length while maintaining and, in some cases, improving accuracy. This study aimed at validating a CAT based on Item Response Theory (IRT for evaluation of generic HRQoL: the CAT-Health instrument. Methods Cross-sectional study of subjects aged over 18 attending Primary Care Centres for any reason. CAT-Health was administered along with the SF-12 Health Survey. Age, gender and a checklist of chronic conditions were also collected. CAT-Health was evaluated considering: 1 feasibility: completion time and test length; 2 content range coverage, Item Exposure Rate (IER and test precision; and 3 construct validity: differences in the CAT-Health scores according to clinical variables and correlations between both questionnaires. Results 396 subjects answered CAT-Health and SF-12, 67.2% females, mean age (SD 48.6 (17.7 years. 36.9% did not report any chronic condition. Median completion time for CAT-Health was 81 seconds (IQ range = 59-118 and it increased with age (p Conclusions Although domain-specific CATs exist for various areas of HRQoL, CAT-Health is one of the first IRT-based CATs designed to evaluate generic HRQoL and it has proven feasible, valid and efficient, when administered to a broad sample of individuals attending primary care settings.

  3. Friction compensation for low velocity control of hydraulic flight motion simulator: A simple adaptive robust approach

    Yao Jianyong; Jiao Zongxia; Han Songshan

    2013-01-01

    Low-velocity tracking capability is a key performance of flight motion simulator (FMS),which is mainly affected by the nonlinear friction force.Though many compensation schemes with ad hoc friction models have been proposed,this paper deals with low-velocity control without friction model,since it is easy to be implemented in practice.Firstly,a nonlinear model of the FMS middle frame,which is driven by a hydraulic rotary actuator,is built.Noting that in the low velocity region,the unmodeled friction force is mainly characterized by a changing-slowly part,thus a simple adaptive law can be employed to learn this changing-slowly part and compensate it.To guarantee the boundedness of adaptation process,a discontinuous projection is utilized and then a robust scheme is proposed.The controller achieves a prescribed output tracking transient performance and final tracking accuracy in general while obtaining asymptotic output tracking in the absence of modeling errors.In addition,a saturated projection adaptive scheme is proposed to improve the globally learning capability when the velocity becomes large,which might make the previous proposed projection-based adaptive law be unstable.Theoretical and extensive experimental results are obtained to verify the high-performance nature of the proposed adaptive robust control strategy.

  4. The three-hit concept of vulnerability and resilience: towards understanding adaptation to early-life adversity outcome

    Daskalakis, Nikolaos P.; Bagot, Rosemary C.; Parker, Karen J.; Vinkers, Christiaan H.; de Kloet, E. R.

    2013-01-01

    Stressful experiences during early-life can modulate the genetic programming of specific brain circuits underlying emotional and cognitive aspects of behavioral adaptation to stressful experiences later in life. Although this programming effect exerted by experience-related factors is an important determinant of mental health, its outcome depends on cognitive inputs and hence the valence an individual assigns to a given environmental context. From this perspective we will highlight, with studies in rodents, non-human primates and humans, the three-hit concept of vulnerability and resilience to stress-related mental disorders, which is based on gene-environment interactions during critical phases of perinatal and juvenile brain development. The three-hit (i.e., hit-1: genetic predisposition, hit-2: early-life environment, and hit-3: later-life environment) concept accommodates the cumulative stress hypothesis stating that in a given context vulnerability is enhanced when failure to cope with adversity accumulates. Alternatively, the concept also points to the individual’s predictive adaptive capacity, which underlies the stress inoculation and match/mismatch hypotheses. The latter hypotheses propose that the experience of relatively mild early-life adversity prepares for the future and promotes resilience to similar challenges in later-life; when a mismatch occurs between early and later-life experience, coping is compromised and vulnerability is enhanced. The three-hit concept is fundamental for understanding how individuals can either be prepared for coping with life to come and remain resilient or are unable to do so and succumb to a stress-related mental disorder, under seemingly identical circumstances. PMID:23838101

  5. Simulation work of fatigue life prediction of rubber automotive components

    Samad, M S A [Automotive Engineering Unit, Institute of Advanced Technology, University Putra Malaysia, 43400, UPM Serdang, Selangor (Malaysia); Ali, Aidy, E-mail: aidy@eng.upm.edu.my [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang Selangor (Malaysia)

    2010-05-15

    The usage of rubbers has always been so important, especially in automotive industries. Rubbers have a hyper elastic behaviour which is the ability to withstand very large strain without failure. The normal applications for rubbers are used for shock absorption, sound isolation and mounting. In this study, the predictions of fatigue life of an engine mount of rubber automotive components were presented. The finite element analysis was performed to predict the critical part and the strain output were incorporated into fatigue model for prediction. The predicted result shows agreement in term of failure location of rubber mount.

  6. Simulation work of fatigue life prediction of rubber automotive components

    The usage of rubbers has always been so important, especially in automotive industries. Rubbers have a hyper elastic behaviour which is the ability to withstand very large strain without failure. The normal applications for rubbers are used for shock absorption, sound isolation and mounting. In this study, the predictions of fatigue life of an engine mount of rubber automotive components were presented. The finite element analysis was performed to predict the critical part and the strain output were incorporated into fatigue model for prediction. The predicted result shows agreement in term of failure location of rubber mount.

  7. Aeroacoustic Simulation of Nose Landing Gear on Adaptive Unstructured Grids With FUN3D

    Vatsa, Veer N.; Khorrami, Mehdi R.; Park, Michael A.; Lockhard, David P.

    2013-01-01

    Numerical simulations have been performed for a partially-dressed, cavity-closed nose landing gear configuration that was tested in NASA Langley s closed-wall Basic Aerodynamic Research Tunnel (BART) and in the University of Florida's open-jet acoustic facility known as the UFAFF. The unstructured-grid flow solver FUN3D, developed at NASA Langley Research center, is used to compute the unsteady flow field for this configuration. Starting with a coarse grid, a series of successively finer grids were generated using the adaptive gridding methodology available in the FUN3D code. A hybrid Reynolds-averaged Navier-Stokes/large eddy simulation (RANS/LES) turbulence model is used for these computations. Time-averaged and instantaneous solutions obtained on these grids are compared with the measured data. In general, the correlation with the experimental data improves with grid refinement. A similar trend is observed for sound pressure levels obtained by using these CFD solutions as input to a FfowcsWilliams-Hawkings noise propagation code to compute the farfield noise levels. In general, the numerical solutions obtained on adapted grids compare well with the hand-tuned enriched fine grid solutions and experimental data. In addition, the grid adaption strategy discussed here simplifies the grid generation process, and results in improved computational efficiency of CFD simulations.

  8. Integrating Problem-Based Learning and Simulation: Effects on Student Motivation and Life Skills.

    Roh, Young Sook; Kim, Sang Suk

    2015-07-01

    Previous research has suggested that a teaching strategy integrating problem-based learning and simulation may be superior to traditional lecture. The purpose of this study was to assess learner motivation and life skills before and after taking a course involving problem-based learning and simulation. The design used repeated measures with a convenience sample of 83 second-year nursing students who completed the integrated course. Data from a self-administered questionnaire measuring learner motivation and life skills were collected at pretest, post-problem-based learning, and post-simulation time points. Repeated-measures analysis of variance determined that the mean scores for total learner motivation (F=6.62, P=.003), communication (F=8.27, Pmotivation and total life skills significantly increased both from pretest to postsimulation and from post-problem-based learning test to postsimulation test. Subscales of learner motivation and life skills, intrinsic goal orientation, self-efficacy for learning and performance, problem-solving skills, and self-directed learning skills significantly increased both from pretest to postsimulation test and from post-problem-based learning test to post-simulation test. The results demonstrate that an integrating problem-based learning and simulation course elicits significant improvement in learner motivation and life skills. Simulation plus problem-based learning is more effective than problem-based learning alone at increasing intrinsic goal orientation, task value, self-efficacy for learning and performance, problem solving, and self-directed learning. PMID:26066305

  9. Neural correlates of adaptive social responses to real-life frustrating situations: a functional MRI study

    Sekiguchi, Atsushi; Sugiura, Motoaki; Yokoyama, Satoru; Sassa, Yuko; HORIE, Kaoru; Sato, Shigeru; Kawashima, Ryuta

    2013-01-01

    Background Frustrating situations are encountered daily, and it is necessary to respond in an adaptive fashion. A psychological definition states that adaptive social behaviors are “self-performing” and “contain a solution.” The present study investigated the neural correlates of adaptive social responses to frustrating situations by assessing the dimension of causal attribution. Based on attribution theory, internal causality refers to one’s aptitudes that cause natural responses in real-lif...

  10. Hardware In The Loop Simulator in UAV Rapid Development Life Cycle

    Adiprawita, Widyawardana; Semibiring, Jaka

    2008-01-01

    Field trial is very critical and high risk in autonomous UAV development life cycle. Hardware in the loop (HIL) simulation is a computer simulation that has the ability to simulate UAV flight characteristic, sensor modeling and actuator modeling while communicating in real time with the UAV autopilot hardware. HIL simulation can be used to test the UAV autopilot hardware reliability, test the closed loop performance of the overall system and tuning the control parameter. By rigorous testing in the HIL simulator, the risk in the field trial can be minimized.

  11. Brazilian cross-cultural translation and adaptation of the "Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items"

    Aline Mansueto Mourao; Caroline Martins Araujo; Luiz Sergio Mageste Barbosa; Rodrigo Santiago Gomez; Burns, Ted M.; Stela Maris Aguiar Lemos; Antonio Lucio Teixeira

    2013-01-01

    Objective To translate and to perform the cross-cultural adaptation of the “Questionnaire of Life Quality Specific for Myasthenia Gravis - 15 items” (MG-QOL15). Method The original English version of the questionnaire was translated into Portuguese. This version was revised and translated back into English. Later, both English versions were compared and the divergences were corrected in the Portuguese text. At a second stage, ten patients with MG followed at the Neuromuscular Diseases Clini...

  12. Adaptations to Hydrothermal Vent Life in Kiwa tyleri, a New Species of Yeti Crab from the East Scotia Ridge, Antarctica.

    Sven Thatje

    Full Text Available Hydrothermal vents in the Southern Ocean are the physiologically most isolated chemosynthetic environments known. Here, we describe Kiwa tyleri sp. nov., the first species of yeti crab known from the Southern Ocean. Kiwa tyleri belongs to the family Kiwaidae and is the visually dominant macrofauna of two known vent sites situated on the northern and southern segments of the East Scotia Ridge (ESR. The species is known to depend on primary productivity by chemosynthetic bacteria and resides at the warm-eurythermal vent environment for most of its life; its short-range distribution away from vents (few metres is physiologically constrained by the stable, cold waters of the surrounding Southern Ocean. Kiwa tylerihas been shown to present differential life history adaptations in response to this contrasting thermal environment. Morphological adaptations specific to life in warm-eurythermal waters, as found on - or in close proximity of - vent chimneys, are discussed in comparison with adaptations seen in the other two known members of the family (K. hirsuta, K. puravida, which show a preference for low temperature chemosynthetic environments.

  13. Goal-Oriented Self-Adaptive hp Finite Element Simulation of 3D DC Borehole Resistivity Simulations

    Calo, Victor M.

    2011-05-14

    In this paper we present a goal-oriented self-adaptive hp Finite Element Method (hp-FEM) with shared data structures and a parallel multi-frontal direct solver. The algorithm automatically generates (without any user interaction) a sequence of meshes delivering exponential convergence of a prescribed quantity of interest with respect to the number of degrees of freedom. The sequence of meshes is generated from a given initial mesh, by performing h (breaking elements into smaller elements), p (adjusting polynomial orders of approximation) or hp (both) refinements on the finite elements. The new parallel implementation utilizes a computational mesh shared between multiple processors. All computational algorithms, including automatic hp goal-oriented adaptivity and the solver work fully in parallel. We describe the parallel self-adaptive hp-FEM algorithm with shared computational domain, as well as its efficiency measurements. We apply the methodology described to the three-dimensional simulation of the borehole resistivity measurement of direct current through casing in the presence of invasion.

  14. The experience of end of life care simulation at a rural Australian University.

    Gillan, Pauline C; Parmenter, Glenda; van der Riet, Pamela J; Jeong, Sarah

    2013-11-01

    Providing end of life care is a challenging and anxiety provoking prospect for many undergraduate nursing students and many students report a lack of preparedness in providing care. The limited availability of appropriate clinical placements limits the opportunities for nursing students to gain experience in end of life care. Advances in simulation techniques using high fidelity mannequins enable the mimicking of complex patient scenarios such as cessation of life in the provision of end of life care. A group of nursing academics at a rural Australian University designed, developed and implemented end of life care simulation to a group of 3rd year nursing students. The aim of this paper is to report on the evaluation of this educational innovation. Five major themes were identified through analysis of student evaluations: 1) Linking of theory to practice; 2) Approaching families of dying patients; 3) An encounter with death; 4) 'Hands on' experience in a 'protected environment'; and 5) Importance of post simulation discussion and debriefing. End of life care simulation has provided a valuable experience that can be difficult to obtain in clinical practice settings. However, the challenges discussed in this paper need to be taken into consideration for future use. PMID:23260617

  15. Brightest Cluster Galaxies in Cosmological Simulations with Adaptive Mesh Refinement: Successes and Failures

    Martizzi, Davide; Moore, Ben

    2014-01-01

    A large sample of cosmological hydrodynamical zoom-in simulations with Adaptive Mesh Refinement (AMR) is analysed to study the properties of simulated Brightest Cluster Galaxies (BCGs). Following the formation and evolution of BCGs requires modeling an entire galaxy cluster, because the BCG properties are largely influenced by the state of the gas in the cluster and by interactions and mergers with satellites. BCG evolution is also deeply influenced by the presence of gas heating sources such as Active Galactic Nuclei (AGNs) that prevent catastrophic cooling of large amounts of gas. We show that AGN feedback is one of the most important mechanisms in shaping the properties of BCGs at low redshift by analysing our statistical sample of simulations with and without AGN feedback. When AGN feedback is included BCG masses, sizes, star formation rates and kinematic properties are closer to those of the observed systems. Some small discrepancies are observed only for the most massive BCGs, an effect that might be du...

  16. Reinforcement Corrosion: Numerical Simulation and Service Life Prediction

    Michel, Alexander

    substances in concrete a heat and mass transport model was applied, which is based on thermodynamic principles. To incorporate the influence of temperature and chloride on the moisture sorption extensions were made using experimental results. The impact ofchlorides on the moisture sorption was accounted for...... concrete specimens was demonstrated comparing experimental ingress results and numerical simulations. The corrosion model, which is coupled to the transport model, was used to describe electrochemical processes at the reinforcement surface. The corrosion model was based on generally accepted physical laws...... describing thermodynamics and kinetics of electrochemical processes. The applicabilityof the model to capture various reinforcement corrosion phenomena, such as activation, resistance, and concentration polarisation as well as the impact of temperature and relative humidity was demonstrated comparing...

  17. Accelerating Markov chain Monte Carlo simulation by differential evolution with self-adaptive randomized subspace sampling

    Vrugt, Jasper A [Los Alamos National Laboratory; Hyman, James M [Los Alamos National Laboratory; Robinson, Bruce A [Los Alamos National Laboratory; Higdon, Dave [Los Alamos National Laboratory; Ter Braak, Cajo J F [NETHERLANDS; Diks, Cees G H [UNIV OF AMSTERDAM

    2008-01-01

    Markov chain Monte Carlo (MCMC) methods have found widespread use in many fields of study to estimate the average properties of complex systems, and for posterior inference in a Bayesian framework. Existing theory and experiments prove convergence of well constructed MCMC schemes to the appropriate limiting distribution under a variety of different conditions. In practice, however this convergence is often observed to be disturbingly slow. This is frequently caused by an inappropriate selection of the proposal distribution used to generate trial moves in the Markov Chain. Here we show that significant improvements to the efficiency of MCMC simulation can be made by using a self-adaptive Differential Evolution learning strategy within a population-based evolutionary framework. This scheme, entitled DiffeRential Evolution Adaptive Metropolis or DREAM, runs multiple different chains simultaneously for global exploration, and automatically tunes the scale and orientation of the proposal distribution in randomized subspaces during the search. Ergodicity of the algorithm is proved, and various examples involving nonlinearity, high-dimensionality, and multimodality show that DREAM is generally superior to other adaptive MCMC sampling approaches. The DREAM scheme significantly enhances the applicability of MCMC simulation to complex, multi-modal search problems.

  18. A Hamiltonian theory of adaptive resolution simulations of classical and quantum models of nuclei

    Kreis, Karsten; Donadio, Davide; Kremer, Kurt; Potestio, Raffaello

    2015-03-01

    Quantum delocalization of atomic nuclei strongly affects the physical properties of low temperature systems, such as superfluid helium. However, also at room temperature nuclear quantum effects can play an important role for molecules composed by light atoms. An accurate modeling of these effects is possible making use of the Path Integral formulation of Quantum Mechanics. In simulations, this numerically expensive description can be restricted to a small region of space, while modeling the remaining atoms as classical particles. In this way the computational resources required can be significantly reduced. In the present talk we demonstrate the derivation of a Hamiltonian formulation for a bottom-up, theoretically solid coupling between a classical model and a Path Integral description of the same system. The coupling between the two models is established with the so-called Hamiltonian Adaptive Resolution Scheme, resulting in a fully adaptive setup in which molecules can freely diffuse across the classical and the Path Integral regions by smoothly switching their description on the fly. Finally, we show the validation of the approach by means of adaptive resolution simulations of low temperature parahydrogen. Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz, Germany.

  19. Selective adaptation in networks of heterogeneous populations: model, simulation, and experiment.

    Avner Wallach

    2008-02-01

    Full Text Available Biological systems often change their responsiveness when subject to persistent stimulation, a phenomenon termed adaptation. In neural systems, this process is often selective, allowing the system to adapt to one stimulus while preserving its sensitivity to another. In some studies, it has been shown that adaptation to a frequent stimulus increases the system's sensitivity to rare stimuli. These phenomena were explained in previous work as a result of complex interactions between the various subpopulations of the network. A formal description and analysis of neuronal systems, however, is hindered by the network's heterogeneity and by the multitude of processes taking place at different time-scales. Viewing neural networks as populations of interacting elements, we develop a framework that facilitates a formal analysis of complex, structured, heterogeneous networks. The formulation developed is based on an analysis of the availability of activity dependent resources, and their effects on network responsiveness. This approach offers a simple mechanistic explanation for selective adaptation, and leads to several predictions that were corroborated in both computer simulations and in cultures of cortical neurons developing in vitro. The framework is sufficiently general to apply to different biological systems, and was demonstrated in two different cases.

  20. The evolution of an annual life cycle in killifish: adaptation to ephemeral aquatic environments through embryonic diapause.

    Furness, Andrew I

    2016-08-01

    An annual life cycle is characterized by growth, maturity, and reproduction condensed into a single, short season favourable to development, with production of embryos (seeds, cysts, or eggs) capable of surviving harsh conditions which juveniles or adults cannot tolerate. More typically associated with plants in desert environments, or temperate-zone insects exposed to freezing winters, the evolution of an annual life cycle in vertebrates is fairly novel. Killifish, small sexually dimorphic fishes in the Order Cyprinodontiformes, have adapted to seasonally ephemeral water bodies across much of Africa and South America through the independent evolution of an annual life history. These annual killifish produce hardy desiccation-resistant eggs that undergo diapause (developmental arrest) and remain buried in the soil for long periods when fish have perished due to the drying of their habitat. Killifish are found in aquatic habitats that span a continuum from permanent and stable to seasonal and variable, thus providing a useful system in which to piece together the evolutionary history of this life cycle using natural comparative variation. I first review adaptations for life in ephemeral aquatic environments in killifish, with particular emphasis on the evolution of embryonic diapause. I then bring together available evidence from a variety of approaches and provide a scenario for how this annual life cycle evolved. There are a number of features within Aplocheiloidei killifish including their inhabitation of marginal or edge aquatic habitat, their small size and rapid attainment of maturity, and egg properties that make them particularly well suited to the colonization of ephemeral waters. PMID:25969869

  1. Advanced adaptive computational methods for Navier-Stokes simulations in rotorcraft aerodynamics

    Stowers, S. T.; Bass, J. M.; Oden, J. T.

    1993-01-01

    A phase 2 research and development effort was conducted in area transonic, compressible, inviscid flows with an ultimate goal of numerically modeling complex flows inherent in advanced helicopter blade designs. The algorithms and methodologies therefore are classified as adaptive methods, which are error estimation techniques for approximating the local numerical error, and automatically refine or unrefine the mesh so as to deliver a given level of accuracy. The result is a scheme which attempts to produce the best possible results with the least number of grid points, degrees of freedom, and operations. These types of schemes automatically locate and resolve shocks, shear layers, and other flow details to an accuracy level specified by the user of the code. The phase 1 work involved a feasibility study of h-adaptive methods for steady viscous flows, with emphasis on accurate simulation of vortex initiation, migration, and interaction. Phase 2 effort focused on extending these algorithms and methodologies to a three-dimensional topology.

  2. An adaptive tau-leaping method for stochastic simulations of reaction-diffusion systems

    Padgett, Jill M. A.; Ilie, Silvana

    2016-03-01

    Stochastic modelling is critical for studying many biochemical processes in a cell, in particular when some reacting species have low population numbers. For many such cellular processes the spatial distribution of the molecular species plays a key role. The evolution of spatially heterogeneous biochemical systems with some species in low amounts is accurately described by the mesoscopic model of the Reaction-Diffusion Master Equation. The Inhomogeneous Stochastic Simulation Algorithm provides an exact strategy to numerically solve this model, but it is computationally very expensive on realistic applications. We propose a novel adaptive time-stepping scheme for the tau-leaping method for approximating the solution of the Reaction-Diffusion Master Equation. This technique combines effective strategies for variable time-stepping with path preservation to reduce the computational cost, while maintaining the desired accuracy. The numerical tests on various examples arising in applications show the improved efficiency achieved by the new adaptive method.

  3. Adaptive and Iterative Methods for Simulations of Nanopores with the PNP-Stokes Equations

    Mitscha-Baude, Gregor; Tulzer, Gerhard; Heitzinger, Clemens

    2016-01-01

    We present a 3D finite element solver for the nonlinear Poisson-Nernst-Planck (PNP) equations for electrodiffusion, coupled to the Stokes system of fluid dynamics. The model serves as a building block for the simulation of macromolecule dynamics inside nanopore sensors. We add to existing numerical approaches by deploying goal-oriented adaptive mesh refinement. To reduce the computation overhead of mesh adaptivity, our error estimator uses the much cheaper Poisson-Boltzmann equation as a simplified model, which is justified on heuristic grounds but shown to work well in practice. To address the nonlinearity in the full PNP-Stokes system, three different linearization schemes are proposed and investigated, with two segregated iterative approaches both outperforming a naive application of Newton's method. Numerical experiments are reported on a real-world nanopore sensor geometry. We also investigate two different models for the interaction of target molecules with the nanopore sensor through the PNP-Stokes equ...

  4. Efficient wave function simulations in nonlinear quantum optics using an adaptive coherent state basis

    Full text: We show that a suitable set of coherent basis states placed on a discrete hexagonal grid can be used to numerically very accurately represent general quantum states in a memory efficient way. Adding an algorithm for dynamic basis adaptation allows highly accurate Quantum Monte Carlo wave function simulations with small basis sets. At the example of the intricate nonlinear dynamics of an optical parametric oscillator around threshold, we demonstrate that this approach yields accurate time dependent solutions with a substantially smaller basis sets than required for a photon number basis. Above threshold the adaptive basis splits into localized subsets allowing efficient representation of bimodal or even more complex phase space distributions and directly yields an intuitive physical picture of the ongoing dynamics. (author)

  5. Advantages and challenges in coupling an ideal gas to atomistic models in adaptive resolution simulations

    Kreis, K.; Fogarty, A. C.; Kremer, K.; Potestio, R.

    2015-09-01

    In adaptive resolution simulations, molecular fluids are modeled employing different levels of resolution in different subregions of the system. When traveling from one region to the other, particles change their resolution on the fly. One of the main advantages of such approaches is the computational efficiency gained in the coarse-grained region. In this respect the best coarse-grained system to employ in the low resolution region would be the ideal gas, making intermolecular force calculations in the coarse-grained subdomain redundant. In this case, however, a smooth coupling is challenging due to the high energetic imbalance between typical liquids and a system of non-interacting particles. In the present work, we investigate this approach, using as a test case the most biologically relevant fluid, water. We demonstrate that a successful coupling of water to the ideal gas can be achieved with current adaptive resolution methods, and discuss the issues that remain to be addressed.

  6. In Patients with Cirrhosis, Driving Simulator Performance is Associated With Real-life Driving

    Lauridsen, Mette Enok Munk; Thacker, Leroy R; White, Melanie B;

    2016-01-01

    , not all patients with MHE are unsafe drivers, but it is unclear how to distinguish them from unsafe drivers. We investigated the link between performance on driving simulators and real-life automobile accidents and traffic violations. We also aimed to identify features of unsafe drivers with cirrhosis...... were collected on traffic violations and automobile accidents from the Virginia Department of Motor Vehicles and from participants' self-assessments when they entered the study, and from 73 participants 1 year later. Participants also completed a questionnaire about alcohol use and cessation patterns......% vs 0%, P=.02). Alcohol cessation within less than 1 year and illegal turns during simulator navigation tasks were associated with real-life automobile crashes and MHE on in regression analysis; road edge excursions in the simulator were associated with real-life traffic violations. Personal...

  7. Reactively and Anticipatory Behaving Agents for Artificial Life Simulations

    Kohout, Karel; Nahodil, Pavel

    2010-11-01

    Reactive behavior is still considered and the exact opposite for the anticipatory one. Despite the advances on the field of anticipation there are little thoughts on relation with the reactive behavior, the similarities and where the boundary is. In this article we will present our viewpoint and we will try to show that reactive and anticipatory behavior can be combined. This is the basic ground of our unified theory for anticipatory behavior architecture. We still miss such compact theory, which would integrate multiple aspects of anticipation. My multi-level anticipatory behavior approach is based on the current understanding of anticipation from both the artificial intelligence and biology point of view. As part of the explanation we will also elaborate on the topic of weak and strong artificial life. Anticipation is not matter of a single mechanism in a living organism. It was noted already that it happens on many different levels even in the very simple creatures. What we consider to be important for our work and what is our original though is that it happens even without voluntary control. We believe that this is novelty though for the anticipation theory. Naturally research of anticipation was in the beginning of this decade focused on the anticipatory principles bringing advances on the field itself. This allowed us to build on those, look at them from higher perspective, and use not one but multiple levels of anticipation in a creature design. This presents second original though and that is composition of the agent architecture that has anticipation built in almost every function. In this article we will focus only on first two levels within the 8-factor anticipation framework. We will introduce them as defined categories of anticipation and describe them from theory and implementation algorithm point of view. We will also present an experiment conducted, however this experiment serves more as explanatory example. These first two levels may seem trivial

  8. Evolution of complex life cycles in trophically transmitted helminths. II. How do life-history stages adapt to their hosts?

    Parker, G A; Ball, M A; Chubb, J C

    2015-02-01

    We review how trophically transmitted helminths adapt to the special problems associated with successive hosts in complex cycles. In intermediate hosts, larvae typically show growth arrest at larval maturity (GALM). Theoretical models indicate that optimization of size at GALM requires larval mortality rate to increase with time between infection and GALM: low larval growth or paratenicity (no growth) arises from unfavourable growth and mortality rates in the intermediate host and low transmission rates to the definitive host. Reverse conditions favour high GALM size or continuous growth. Some support is found for these predictions. Intermediate host manipulation involves predation suppression (which decreases host vulnerability before the larva can establish in its next host) and predation enhancement (which increases host vulnerability after the larva can establish in its next host). Switches between suppression and enhancement suggest adaptive manipulation. Manipulation conflicts can occur between larvae of different ages/species a host individual. Larvae must usually develop to GALM before becoming infective to the next host, possibly due to trade-offs, e.g. between growth/survival in the present host and infection ability for the next host. In definitive hosts, if mortality rate is constant, optimal growth before switching to reproduction is set by the growth/morality rate ratio. Rarely, no growth occurs in definitive hosts, predicted (with empirical support) when larval size on infection exceeds growth/mortality rate. Tissue migration patterns and residence sites may be explained by variations in growth/mortality rates between host gut and soma, migration costs and benefits of releasing eggs in the gut. PMID:25645609

  9. Water balance in desert arthropods. Despite their small size, arthropods may be highly adapted for life in xeric conditions.

    Edney, E B

    1967-05-26

    As judged by the number of species, or of individuals, arthropods are an extremely successful group of desert inhabitants. There is very great structural and physiological diversity within the group, and since adaptations to desert life open to one are not open to all. we should not expect to find the maximum possible development of adaptive features in any arthropod simply because it lives in a desert. Most adult insects fly; their larvae and all other arthropods do not, and their adaptations will differ accordingly. Desert beetles have very impermeable cuticles and tolerate high body temperatures, while desert cockroaches live below the sand. have more permeable cuticles, and absorb water vapor. There is probably no single respect in which all desert arthropods differ from insects of other environments. Perhaps a profitable way of viewing desert animals is to recognize that each is a whole organism with a specific collection of adaptations that must be consistent within themselves and which are associated with a specific mode of life and a specific evolutionary history. The arthropod organization is capable of producing highly efficient desert species. There is, however, a converse way of looking at the situation, Which is often neglected but which may be of general biological interest: does the evolution of adaptations to desert environments necessarily involve loss of viability in more mesic habitats? If so, then what are these disavantages- what, for example, is the disadvantage of a highly impermeable cuticle? In some cases the answer is clear: sandroaches need sand dunes to live in because they are morphologically and behaviorly specialized for this habitat. More often the answer is not obvious. PMID:6024185

  10. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Ry, Rexha Verdhora, E-mail: rexha.vry@gmail.com [Master Program of Geophysical Engineering, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Institut Teknologi Bandung, Jalan Ganesha No.10, Bandung 40132 (Indonesia)

    2015-04-24

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location.

  11. Improve earthquake hypocenter using adaptive simulated annealing inversion in regional tectonic, volcano tectonic, and geothermal observation

    Observation of earthquakes is routinely used widely in tectonic activity observation, and also in local scale such as volcano tectonic and geothermal activity observation. It is necessary for determining the location of precise hypocenter which the process involves finding a hypocenter location that has minimum error between the observed and the calculated travel times. When solving this nonlinear inverse problem, simulated annealing inversion method can be applied to such global optimization problems, which the convergence of its solution is independent of the initial model. In this study, we developed own program codeby applying adaptive simulated annealing inversion in Matlab environment. We applied this method to determine earthquake hypocenter using several data cases which are regional tectonic, volcano tectonic, and geothermal field. The travel times were calculated using ray tracing shooting method. We then compared its results with the results using Geiger’s method to analyze its reliability. Our results show hypocenter location has smaller RMS error compared to the Geiger’s result that can be statistically associated with better solution. The hypocenter of earthquakes also well correlated with geological structure in the study area. Werecommend using adaptive simulated annealing inversion to relocate hypocenter location in purpose to get precise and accurate earthquake location

  12. Adaptations to isolated shoulder fatigue during simulated repetitive work. Part I: Fatigue.

    Tse, Calvin T F; McDonald, Alison C; Keir, Peter J

    2016-08-01

    Upper extremity muscle fatigue is challenging to identify during industrial tasks and places changing demands on the shoulder complex that are not fully understood. The purpose of this investigation was to examine adaptation strategies in response to isolated anterior deltoid muscle fatigue while performing simulated repetitive work. Participants completed two blocks of simulated repetitive work separated by an anterior deltoid fatigue protocol; the first block had 20 work cycles and the post-fatigue block had 60 cycles. Each work cycle was 60s in duration and included 4 tasks: handle pull, cap rotation, drill press and handle push. Surface EMG of 14 muscles and upper body kinematics were recorded. Immediately following fatigue, glenohumeral flexion strength was reduced, rating of perceived exertion scores increased and signs of muscle fatigue (increased EMG amplitude, decreased EMG frequency) were present in anterior and posterior deltoids, latissimus dorsi and serratus anterior. Along with other kinematic and muscle activity changes, scapular reorientation occurred in all of the simulated tasks and generally served to increase the width of the subacromial space. These findings suggest that immediately following fatigue people adapt by repositioning joints to maintain task performance and may also prioritize maintaining subacromial space width. PMID:26208429

  13. Conception d'un environnement virtuel avec adaptation de l'immersion pour la simulation de conduite en fauteuil roulant

    Goncalves, Frédéric

    2014-01-01

    This thesis focuses on the adaptation of the immersion in a driving wheelchair simulation. This is the study of sensory feedback realism involved in a virtual environment in order to adapt the immersion according to user preferences and the task to perform. These works were performed within the AccesSim project supported by the Ile de France region. The project objective is to develop a dynamic simulator to evaluate the accessibility and also urban environment, to conduct training in the use ...

  14. Direct numerical simulations of particle-laden density currents with adaptive, discontinuous finite elements

    S. D. Parkinson

    2014-09-01

    Full Text Available High-resolution direct numerical simulations (DNSs are an important tool for the detailed analysis of turbidity current dynamics. Models that resolve the vertical structure and turbulence of the flow are typically based upon the Navier–Stokes equations. Two-dimensional simulations are known to produce unrealistic cohesive vortices that are not representative of the real three-dimensional physics. The effect of this phenomena is particularly apparent in the later stages of flow propagation. The ideal solution to this problem is to run the simulation in three dimensions but this is computationally expensive. This paper presents a novel finite-element (FE DNS turbidity current model that has been built within Fluidity, an open source, general purpose, computational fluid dynamics code. The model is validated through re-creation of a lock release density current at a Grashof number of 5 × 106 in two and three dimensions. Validation of the model considers the flow energy budget, sedimentation rate, head speed, wall normal velocity profiles and the final deposit. Conservation of energy in particular is found to be a good metric for measuring model performance in capturing the range of dynamics on a range of meshes. FE models scale well over many thousands of processors and do not impose restrictions on domain shape, but they are computationally expensive. The use of adaptive mesh optimisation is shown to reduce the required element count by approximately two orders of magnitude in comparison with fixed, uniform mesh simulations. This leads to a substantial reduction in computational cost. The computational savings and flexibility afforded by adaptivity along with the flexibility of FE methods make this model well suited to simulating turbidity currents in complex domains.

  15. Simulated annealing method for electronic circuits design: adaptation and comparison with other optimization methods

    The circuit design problem consists in determining acceptable parameter values (resistors, capacitors, transistors geometries ...) which allow the circuit to meet various user given operational criteria (DC consumption, AC bandwidth, transient times ...). This task is equivalent to a multidimensional and/or multi objective optimization problem: n-variables functions have to be minimized in an hyper-rectangular domain ; equality constraints can be eventually specified. A similar problem consists in fitting component models. In this way, the optimization variables are the model parameters and one aims at minimizing a cost function built on the error between the model response and the data measured on the component. The chosen optimization method for this kind of problem is the simulated annealing method. This method, provided by the combinatorial optimization domain, has been adapted and compared with other global optimization methods for the continuous variables problems. An efficient strategy of variables discretization and a set of complementary stopping criteria have been proposed. The different parameters of the method have been adjusted with analytical functions of which minima are known, classically used in the literature. Our simulated annealing algorithm has been coupled with an open electrical simulator SPICE-PAC of which the modular structure allows the chaining of simulations required by the circuit optimization process. We proposed, for high-dimensional problems, a partitioning technique which ensures proportionality between CPU-time and variables number. To compare our method with others, we have adapted three other methods coming from combinatorial optimization domain - the threshold method, a genetic algorithm and the Tabu search method - The tests have been performed on the same set of test functions and the results allow a first comparison between these methods applied to continuous optimization variables. Finally, our simulated annealing program

  16. Strategy and Simulation of Adaptive RID for Distributed Dynamic Load Balancing in Parallel Systems

    林成江; 李三立

    1997-01-01

    Dynamic load balancing schemes are significant for efficiently executing nonuniform problems in highly parallel multicomputer systems.The objective is to minimize the total exectuion time of single applications.This paper has proposed an ARID strategy for distributed dynamic load balancing.Its principle and control protocol are described,and te communication overhead,the effect on system stability and the performance efficiency are analyzed.Finally,simulation experiments are carried out to compare the adaptive strategy with other dynamic load balancing schemes.

  17. An Explicit Space-time Adaptive Method for Simulating Complex Cardiac Dynamics

    Cherry, E M; Henriquez, C S; Cherry, Elizabeth M.; Greenside, Henry S.; Henriquez, Craig S.

    1999-01-01

    For plane-wave and many-spiral states of the experimentally based Luo-Rudy 1 model of heart tissue in large (8 cm square) domains, we show that an explicit space-time-adaptive time-integration algorithm can achieve an order of magnitude reduction in computational effort and memory--but without a reduction in accuracy--when compared to an algorithm using a uniform space-time mesh at the finest resolution. Our results indicate that such an explicit algorithm can be extended straightforwardly to simulate quantitatively large-scale three-dimensional electrical dynamics over the whole human heart.

  18. Adaptive Resolution Simulations with Self-Adjusting High-Resolution Regions.

    Kreis, Karsten; Potestio, Raffaello; Kremer, Kurt; Fogarty, Aoife C

    2016-08-01

    In adaptive resolution simulations, different regions of a simulation box are modeled with different levels of detail. Particles change their resolution on-the-fly when traveling from one subregion to the other. This method is particularly useful for studying multiscale systems in which effects on a broad range of length and time scales play a role. Until now, the geometry of the high-resolution region has been limited to simple geometries of spherical, cuboid, or cylindrical form, whose shape does not change during the simulation. However, many phenomena involve changes in size and shape of system components, for example, protein folding, polymer collapse, nucleation, and crystallization. In this work, we develop a scheme that uses a series of overlapping spheres to allow for an arbitrary division of space into domains of different levels of resolution. Furthermore, the geometry is automatically adjusted on-the-fly during the simulation according to changes in size and shape of, for example, a solvated macromolecule within the high-resolution region. The proposed approach is validated on liquid water. We then simulate the folding of an atomistically detailed polypeptide solvated in a shell of atomistic water that changes shape as the peptide conformation changes. We demonstrate that the peptide folding process is unperturbed by the use of our methodology. PMID:27384753

  19. Cyberwar XXI: quantifying the unquantifiable: adaptive AI for next-generation conflict simulations

    Miranda, Joseph; von Kleinsmid, Peter; Zalewski, Tony

    2004-08-01

    The era of the "Revolution in Military Affairs," "4th Generation Warfare" and "Asymmetric War" requires novel approaches to modeling warfare at the operational and strategic level of modern conflict. For example, "What if, in response to our planned actions, the adversary reacts in such-and-such a manner? What will our response be? What are the possible unintended consequences?" Next generation conflict simulation tools are required to help create and test novel courses of action (COA's) in support of real-world operations. Conflict simulations allow non-lethal and cost-effective exploration of the "what-if" of COA development. The challenge has been to develop an automated decision-support software tool which allows competing COA"s to be compared in simulated dynamic environments. Principal Investigator Joseph Miranda's research is based on modeling an integrated military, economic, social, infrastructure and information (PMESII) environment. The main effort was to develop an adaptive AI engine which models agents operating within an operational-strategic conflict environment. This was implemented in Cyberwar XXI - a simulation which models COA selection in a PMESII environment. Within this framework, agents simulate decision-making processes and provide predictive capability of the potential behavior of Command Entities. The 2003 Iraq is the first scenario ready for V&V testing.

  20. Adaptive resolution simulation of a biomolecule and its hydration shell: Structural and dynamical properties.

    Fogarty, Aoife C; Potestio, Raffaello; Kremer, Kurt

    2015-05-21

    A fully atomistic modelling of many biophysical and biochemical processes at biologically relevant length- and time scales is beyond our reach with current computational resources, and one approach to overcome this difficulty is the use of multiscale simulation techniques. In such simulations, when system properties necessitate a boundary between resolutions that falls within the solvent region, one can use an approach such as the Adaptive Resolution Scheme (AdResS), in which solvent particles change their resolution on the fly during the simulation. Here, we apply the existing AdResS methodology to biomolecular systems, simulating a fully atomistic protein with an atomistic hydration shell, solvated in a coarse-grained particle reservoir and heat bath. Using as a test case an aqueous solution of the regulatory protein ubiquitin, we first confirm the validity of the AdResS approach for such systems, via an examination of protein and solvent structural and dynamical properties. We then demonstrate how, in addition to providing a computational speedup, such a multiscale AdResS approach can yield otherwise inaccessible physical insights into biomolecular function. We use our methodology to show that protein structure and dynamics can still be correctly modelled using only a few shells of atomistic water molecules. We also discuss aspects of the AdResS methodology peculiar to biomolecular simulations. PMID:26001481

  1. Simulation of adaptive semi-active magnetorheological seat damper for vehicle occupant blast protection

    Yoo, Jin-Hyeong; Murugan, Muthuvel; Wereley, Norman M.

    2013-04-01

    This study investigates a lumped-parameter human body model which includes lower leg in seated posture within a quarter-car model for blast injury assessment simulation. To simulate the shock acceleration of the vehicle, mine blast analysis was conducted on a generic land vehicle crew compartment (sand box) structure. For the purpose of simulating human body dynamics with non-linear parameters, a physical model of a lumped-parameter human body within a quarter car model was implemented using multi-body dynamic simulation software. For implementing the control scheme, a skyhook algorithm was made to work with the multi-body dynamic model by running a co-simulation with the control scheme software plug-in. The injury criteria and tolerance levels for the biomechanical effects are discussed for each of the identified vulnerable body regions, such as the relative head displacement and the neck bending moment. The desired objective of this analytical model development is to study the performance of adaptive semi-active magnetorheological damper that can be used for vehicle-occupant protection technology enhancements to the seat design in a mine-resistant military vehicle.

  2. Adaptive resolution simulation of a biomolecule and its hydration shell: Structural and dynamical properties

    Fogarty, Aoife C.; Potestio, Raffaello; Kremer, Kurt

    2015-05-01

    A fully atomistic modelling of many biophysical and biochemical processes at biologically relevant length- and time scales is beyond our reach with current computational resources, and one approach to overcome this difficulty is the use of multiscale simulation techniques. In such simulations, when system properties necessitate a boundary between resolutions that falls within the solvent region, one can use an approach such as the Adaptive Resolution Scheme (AdResS), in which solvent particles change their resolution on the fly during the simulation. Here, we apply the existing AdResS methodology to biomolecular systems, simulating a fully atomistic protein with an atomistic hydration shell, solvated in a coarse-grained particle reservoir and heat bath. Using as a test case an aqueous solution of the regulatory protein ubiquitin, we first confirm the validity of the AdResS approach for such systems, via an examination of protein and solvent structural and dynamical properties. We then demonstrate how, in addition to providing a computational speedup, such a multiscale AdResS approach can yield otherwise inaccessible physical insights into biomolecular function. We use our methodology to show that protein structure and dynamics can still be correctly modelled using only a few shells of atomistic water molecules. We also discuss aspects of the AdResS methodology peculiar to biomolecular simulations.

  3. Adaptive multi-rate interface: development and experimental verification for real-time hybrid simulation

    Maghareh, Amin; Waldbjørn, Jacob Paamand; Dyke, Shirley J.;

    2016-01-01

    Real-time hybrid simulation (RTHS) is a powerful cyber-physical technique that is a relatively cost-effective method to perform global/local system evaluation of structural systems. A major factor that determines the ability of an RTHS to represent true system-level behavior is the fidelity of the...... numerical substructure. While the use of higher-order models increases fidelity of the simulation, it also increases the demand for computational resources. Because RTHS is executed at real-time, in a conventional RTHS configuration, this increase in computational resources may limit the achievable sampling...... frequencies and/or introduce delays that can degrade its stability and performance. In this study, the Adaptive Multi-rate Interface rate-transitioning and compensation technique is developed to enable the use of more complex numerical models. Such a multi-rate RTHS is strictly executed at real-time, although...

  4. Adaptive MANET Multipath Routing Algorithm Based on the Simulated Annealing Approach

    Sungwook Kim

    2014-01-01

    Full Text Available Mobile ad hoc network represents a system of wireless mobile nodes that can freely and dynamically self-organize network topologies without any preexisting communication infrastructure. Due to characteristics like temporary topology and absence of centralized authority, routing is one of the major issues in ad hoc networks. In this paper, a new multipath routing scheme is proposed by employing simulated annealing approach. The proposed metaheuristic approach can achieve greater and reciprocal advantages in a hostile dynamic real world network situation. Therefore, the proposed routing scheme is a powerful method for finding an effective solution into the conflict mobile ad hoc network routing problem. Simulation results indicate that the proposed paradigm adapts best to the variation of dynamic network situations. The average remaining energy, network throughput, packet loss probability, and traffic load distribution are improved by about 10%, 10%, 5%, and 10%, respectively, more than the existing schemes.

  5. Simulation of a ground-layer adaptive optics system for the Kunlun Dark Universe Survey Telescope

    Peng Jia; Sijiong Zhang

    2013-01-01

    Ground Layer Adaptive Optics (GLAO) is a recently developed technique extensively applied to ground-based telescopes,which mainly compensates for the wavefront errors induced by ground-layer turbulence to get an appropriate point spread function in a wide field of view.The compensation results mainly depend on the turbulence distribution.The atmospheric turbulence at Dome A in the Antarctic is mainly distributed below 15 meters,which is an ideal site for applications of GLAO.The GLAO system has been simulated for the Kunlun Dark Universe Survey Telescope,which will be set up at Dome A,and uses a rotating mirror to generate several laser guide stars and a wavefront sensor with a wide field of view to sequentially measure the wavefronts from different laser guide stars.The system is simulated on a computer and parameters of the system are given,which provide detailed information about the design of a practical GLAO system.

  6. Accelerating the convergence of replica exchange simulations using Gibbs sampling and adaptive temperature sets

    Vogel, Thomas

    2015-01-01

    We recently introduced a novel replica-exchange scheme in which an individual replica can sample from states encountered by other replicas at any previous time by way of a global configuration database, enabling the fast propagation of relevant states through the whole ensemble of replicas. This mechanism depends on the knowledge of global thermodynamic functions which are measured during the simulation and not coupled to the heat bath temperatures driving the individual simulations. Therefore, this setup also allows for a continuous adaptation of the temperature set. In this paper, we will review the new scheme and demonstrate its capability. The method is particularly useful for the fast and reliable estimation of the microcanonical temperature T(U) or, equivalently, of the density of states g(U) over a wide range of energies.

  7. Spatially adaptive radiation-hydrodynamical simulations of galaxy formation during cosmological reionization

    Pawlik, Andreas H.; Schaye, Joop; Dalla Vecchia, Claudio

    2015-08-01

    We present a suite of cosmological radiation-hydrodynamical simulations of the assembly of galaxies driving the reionization of the intergalactic medium (IGM) at z ≳ 6. The simulations account for the hydrodynamical feedback from photoionization heating and the explosion of massive stars as supernovae (SNe). Our reference simulation, which was carried out in a box of size 25 h-1 comovingMpc using 2 × 5123 particles, produces a reasonable reionization history and matches the observed UV luminosity function of galaxies. Simulations with different box sizes and resolutions are used to investigate numerical convergence, and simulations in which either SNe or photoionization heating or both are turned off, are used to investigate the role of feedback from star formation. Ionizing radiation is treated using accurate radiative transfer at the high spatially adaptive resolution at which the hydrodynamics is carried out. SN feedback strongly reduces the star formation rates (SFRs) over nearly the full mass range of simulated galaxies and is required to yield SFRs in agreement with observations. Photoheating helps to suppress star formation in low-mass galaxies, but its impact on the cosmic SFR is small. Because the effect of photoheating is masked by the strong SN feedback, it does not imprint a signature on the UV galaxy luminosity function, although we note that our resolution is insufficient to model star-forming minihaloes cooling through molecular hydrogen transitions. Photoheating does provide a strong positive feedback on reionization because it smooths density fluctuations in the IGM, which lowers the IGM recombination rate substantially. Our simulations demonstrate a tight non-linear coupling of galaxy formation and reionization, motivating the need for the accurate and simultaneous inclusion of photoheating and SN feedback in models of the early Universe.

  8. Adaptive Challenges Rising from the Life Context of African-American Caregiving Grandmothers with Diabetes: A Pilot Study

    Dana Carthron

    2015-08-01

    Full Text Available To understand the challenges arising from the context within which diabetic African-American caregiving grandmothers self-manage their diabetes we used the Adaptive Leadership Framework. Additionally, challenges to retaining this population in a longitudinal study were examined. In this exploratory, longitudinal, qualitative pilot study, data were collected at five time-points over 18 months. We coded the data using content analysis and conducted the within-case and cross-case analyses using data matrices. Lack of awareness of available resources, represented a technical challenge within the life context of these grandmothers and the remaining three themes: family upheaval; priority setting (with subthemes of difficulty meeting basic needs and competing demands; and self-silencing and self-sacrifice represented adaptive challenges. The context of African-American grandmothers’ lives created primarily adaptive challenges that were complex and without immediate solutions. Research is needed to develop culturally and contextually appropriate interventions to help this vulnerable group develop capacity for adaptive work.

  9. Refined adaptive optics simulation with wide field of view for the E-ELT

    Refined simulation tools for wide field AO systems (such as MOAO, MCAO or LTAO) on ELTs present new challenges. Increasing the number of degrees of freedom (scales as the square of the telescope diameter) makes the standard simulation's codes useless due to the huge number of operations to be performed at each step of the Adaptive Optics (AO) loop process. This computational burden requires new approaches in the computation of the DM voltages from WFS data. The classical matrix inversion and the matrix vector multiplication have to be replaced by a cleverer iterative resolution of the Least Square or Minimum Mean Square Error criterion (based on sparse matrices approaches). Moreover, for this new generation of AO systems, concepts themselves will become more complex: data fusion coming from multiple Laser and Natural Guide Stars (LGS / NGS) will have to be optimized, mirrors covering all the field of view associated to dedicated mirrors inside the scientific instrument itself will have to be coupled using split or integrated tomography schemes, differential pupil or/and field rotations will have to be considered, etc. All these new entries should be carefully simulated, analysed and quantified in terms of performance before any implementation in AO systems. For those reasons I developed, in collaboration with the ONERA, a full simulation code, based on iterative solution of linear systems with many parameters (use of sparse matrices). On this basis, I introduced new concepts of filtering and data fusion (LGS / NGS) to effectively manage modes such as tip, tilt and defocus in the entire process of tomographic reconstruction. The code will also eventually help to develop and test complex control laws (Multi-DM and multi-field) who have to manage a combination of adaptive telescope and post-focal instrument including dedicated deformable mirrors. The first application of this simulation tool has been studied in the framework of the EAGLE multi-object spectrograph

  10. ADRC or adaptive controller--A simulation study on artificial blood pump.

    Wu, Yi; Zheng, Qing

    2015-11-01

    Active disturbance rejection control (ADRC) has gained popularity because it requires little knowledge about the system to be controlled, has the inherent disturbance rejection ability, and is easy to tune and implement in practical systems. In this paper, the authors compared the performance of an ADRC and an adaptive controller for an artificial blood pump for end-stage congestive heart failure patients using only the feedback signal of pump differential pressure. The purpose of the control system was to provide sufficient perfusion when the patients' circulation system goes through different pathological and activity variations. Because the mean arterial pressure is equal to the total peripheral flow times the total peripheral resistance, this goal was converted to an expression of making the mean aortic pressure track a reference signal. The simulation results demonstrated that the performance of the ADRC is comparable to that of the adaptive controller with the saving of modeling and computational effort and fewer design parameters: total peripheral flow and mean aortic pressure with ADRC fall within the normal physiological ranges in activity variation (rest to exercise) and in pathological variation (left ventricular strength variation), similar to those values of adaptive controller. PMID:26409226