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Sample records for based onphysiologically realistic

  1. Normal and Pathological NCAT Image and PhantomData Based onPhysiologically Realistic Left Ventricle Finite-Element Models

    Energy Technology Data Exchange (ETDEWEB)

    Veress, Alexander I.; Segars, W. Paul; Weiss, Jeffrey A.; Tsui,Benjamin M.W.; Gullberg, Grant T.

    2006-08-02

    The 4D NURBS-based Cardiac-Torso (NCAT) phantom, whichprovides a realistic model of the normal human anatomy and cardiac andrespiratory motions, is used in medical imaging research to evaluate andimprove imaging devices and techniques, especially dynamic cardiacapplications. One limitation of the phantom is that it lacks the abilityto accurately simulate altered functions of the heart that result fromcardiac pathologies such as coronary artery disease (CAD). The goal ofthis work was to enhance the 4D NCAT phantom by incorporating aphysiologically based, finite-element (FE) mechanical model of the leftventricle (LV) to simulate both normal and abnormal cardiac motions. Thegeometry of the FE mechanical model was based on gated high-resolutionx-ray multi-slice computed tomography (MSCT) data of a healthy malesubject. The myocardial wall was represented as transversely isotropichyperelastic material, with the fiber angle varying from -90 degrees atthe epicardial surface, through 0 degreesat the mid-wall, to 90 degreesat the endocardial surface. A time varying elastance model was used tosimulate fiber contraction, and physiological intraventricular systolicpressure-time curves were applied to simulate the cardiac motion over theentire cardiac cycle. To demonstrate the ability of the FE mechanicalmodel to accurately simulate the normal cardiac motion as well abnormalmotions indicative of CAD, a normal case and two pathologic cases weresimulated and analyzed. In the first pathologic model, a subendocardialanterior ischemic region was defined. A second model was created with atransmural ischemic region defined in the same location. The FE baseddeformations were incorporated into the 4D NCAT cardiac model through thecontrol points that define the cardiac structures in the phantom whichwere set to move according to the predictions of the mechanical model. Asimulation study was performed using the FE-NCAT combination toinvestigate how the differences in contractile function

  2. Realistic face modeling based on multiple deformations

    Institute of Scientific and Technical Information of China (English)

    GONG Xun; WANG Guo-yin

    2007-01-01

    On the basis of the assumption that the human face belongs to a linear class, a multiple-deformation model is proposed to recover face shape from a few points on a single 2D image. Compared to the conventional methods, this study has the following advantages. First, the proposed modified 3D sparse deforming model is a noniterative approach that can compute global translation efficiently and accurately. Subsequently, the overfitting problem can be alleviated based on the proposed multiple deformation model. Finally, by keeping the main features, the texture generated is realistic. The comparison results show that this novel method outperforms the existing methods by using ground truth data and that realistic 3D faces can be recovered efficiently from a single photograph.

  3. UAV based distributed ATR under realistic simulated environmental effects

    Science.gov (United States)

    Chen, Xiaohan; Gong, Shanshan; Schmid, Natalia A.; Valenti, Matthew C.

    2007-04-01

    Over the past several years, the military has grown increasingly reliant upon the use of unattended aerial vehicles (UAVs) for surveillance missions. There is an increasing trend towards fielding swarms of UAVs operating as large-scale sensor networks in the air. Such systems tend to be used primarily for the purpose of acquiring sensory data with the goal of automatic detection, identification, and tracking objects of interest. These trends have been paralleled by advances in both distributed detection, image/signal processing and data fusion techniques. Furthermore, swarmed UAV systems must operate under severe constraints on environmental conditions and sensor limitations. In this work, we investigate the effects of environmental conditions on target detection and recognition performance in a UAV network. We assume that each UAV is equipped with an optical camera, and use a realistic computer simulation to generate synthetic images. The detection algorithm relies on Haar-based features while the automatic target recognition (ATR) algorithm relies on Bessel K features. The performance of both algorithms is evaluated using simulated images that closely mimic data acquired in a UAV network under realistic environmental conditions. We design several fusion techniques and analyze both the case of a single observation and the case of multiple observations of the same target.

  4. Assumptions behind size-based ecosystem models are realistic

    DEFF Research Database (Denmark)

    Andersen, Ken Haste; Blanchard, Julia L.; Fulton, Elizabeth A.;

    2016-01-01

    A recent publication about balanced harvesting (Froese et al., ICES Journal of Marine Science; doi:10.1093/icesjms/fsv122) contains several erroneous statements about size-spectrum models. We refute the statements by showing that the assumptions pertaining to size-spectrum models discussed...... by Froese et al. are realistic and consistent. We further show that the assumption about density-dependence being described by a stock recruitment relationship is responsible for determining whether a peak in the cohort biomass of a population occurs late or early in life. Finally, we argue...

  5. Model-based Evaluation of Location-based Relaying Policies in a Realistic Mobile Indoor Scenario

    DEFF Research Database (Denmark)

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

    2012-01-01

    developed Markov Chain model for a realistic indoor scenario that is based on ray-tracing enriched measurements from the WHERE2 project. These results are furthermore compared to results obtained using an idealistic path loss model, and it is shown that the performance impact of node mobility...

  6. Influence of atmospheric turbulence on OAM-based FSO system with use of realistic link model

    Science.gov (United States)

    Li, Ming; Yu, Zhongyuan; Cvijetic, Milorad

    2016-04-01

    We study the influence of atmospheric turbulence on OAM-based free-space optical (FSO) communication by using the Pump turbulence spectrum model which accurately characterizes the realistic FSO link. A comprehensive comparison is made between the Pump and Kolmogorov spectrum models with respect to the turbulence impact. The calculated results show that obtained turbulence-induced crosstalk is lower, which means that a higher channel capacity is projected when the realistic Pump spectrum is used instead of the Kolmogorov spectrum. We believe that our results prove that performance of practical OAM-based FSO is better than one predicted by using the original Kolmogorov turbulence model.

  7. Toward realistic pursuit-evasion using a roadmap-based approach

    KAUST Repository

    Rodriguez, Samuel

    2011-05-01

    In this work, we describe an approach for modeling and simulating group behaviors for pursuit-evasion that uses a graph-based representation of the environment and integrates multi-agent simulation with roadmap-based path planning. Our approach can be applied to more realistic scenarios than are typically studied in most previous work, including agents moving in 3D environments such as terrains, multi-story buildings, and dynamic environments. We also support more realistic three-dimensional visibility computations that allow evading agents to hide in crowds or behind hills. We demonstrate the utility of this approach on mobile robots and in simulation for a variety of scenarios including pursuit-evasion and tag on terrains, in multi-level buildings, and in crowds. © 2011 IEEE.

  8. Local realistic theory for PDC experiments based on the Wigner formalism

    Energy Technology Data Exchange (ETDEWEB)

    Casado, A.; Risco-Delgado, R. [Sevilla Univ. (Spain). Escuela Superior de Ingenieros Industriales; Santos, E. [Sevilla Univ. (Spain). Escuela Superior de Ingenieros Industriales; Cantabria Univ., Santander (Spain). Dept. de Fisica Moderna

    2001-02-01

    In this article we present a local hidden variables model for all experiments involving photon pairs produced in parametric down conversion, based on the Wigner representation of the radiation field. A modification of the standard quantum theory of detection is made in order to give a local realistic explanation of the counting rates in photodetectors. This model involves the existence of a real zeropoint field, such that the vacuum level of radiation lies below the threshold of the detectors. (orig.)

  9. Complete methodology on generating realistic wind speed profiles based on measurements

    DEFF Research Database (Denmark)

    Gavriluta, Catalin; Spataru, Sergiu; Mosincat, Ioan;

    2012-01-01

    , wind modelling for medium and large time scales is poorly treated in the present literature. This paper presents methods for generating realistic wind speed profiles based on real measurements. The wind speed profile is divided in a low- frequency component (describing long term variations......The wind speed represents the main exogenous signal applied to a Wind Energy Conversion System (WECS) and determines its behavior. The erratic variation of the wind speed, highly dependent on the given site and on the atmospheric conditions, makes the wind speed quite difficult to model. Moreover...

  10. Framework for single input single output nanonetwork-based realistic molecular communication.

    Science.gov (United States)

    Abd El-Atty, Saied M; Gharsseldien, Zakaria M; Lizos, Konstantinos A

    2015-12-01

    Mobile ad hoc molecular nanonetwork (MAMNET) is a new paradigm for the realisation of future nanonetworks. In MAMNET, transmission of nanoscale information from nanomachine to infostation is based on collision and adhesion. In this study, the authors develop a realistic framework for encompassing the electronic structure of the neurotransmitter in the process of transmitting nanoscale information at a single input single output nanonetwork. Nanonetwork performance is evaluated in terms of average packet delay, throughput and incurred traffic rate. Numerical results demonstrate the influence of the neurotransmitter's electronic structure over the performance of nanonetworks.

  11. Towards a unified realistic shell-model Hamiltonian with the monopole-based universal force

    CERN Document Server

    Kaneko, K; Sun, Y; Tazaki, S

    2013-01-01

    We propose a unified realistic shell-model Hamiltonian employing the pairing plus multipole Hamiltonian combined with the monopole interaction constructed starting from the monopole-based universal force by Otsuka it et al. (Phys. Rev. Lett. 104, 012501 (2010)). It is demonstrated that the proposed PMMU model can consistently describe a large amount of spectroscopic data as well as binding energies in the pf and pf5/2g9/2 shell spaces, and could serve as a practical shell model for even heavier mass regions.

  12. A Singular Perturbation Based Midcourse Guidance Law for Realistic Air-to-Air Engagement

    Directory of Open Access Journals (Sweden)

    M Manickavasagam

    2016-12-01

    Full Text Available In this study, a singular perturbation based technique is used for synthesis and analysis of a near optimal midcourse guidance law for realistic air-to-air engagement. After designing the proposed midcourse guidance law using three dimensional point mass formulation it has been validated through detailed realistic six degrees of freedom simulation. During terminal phase only proportional navigation guidance have been used. The calculation of optimal altitude in present guidance law has been carried out using Newton’s method, which needs generally one iteration for convergence and suitable for real-time implementation. Extended Kalman filter based estimator has been used for obtaining evader kinetic information from both radar and seeker noisy measurements available during midcourse and terminal guidance. The data link look angle constraint due to hardware limitation which affects the performance of midcourse guidance has also been incorporated in guidance law design. Robustness of complete simulation has been carried out through Monte Carlo studies. Extension of launch boundary due to singular perturbation over proportional navigation guidance at a given altitude for a typical engagement has also been reported.

  13. Population of 224 realistic human subject-based computational breast phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Erickson, David W. [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Wells, Jered R., E-mail: jered.wells@duke.edu [Clinical Imaging Physics Group and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Sturgeon, Gregory M. [Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 (United States); Samei, Ehsan [Department of Radiology and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Departments of Physics, Electrical and Computer Engineering, and Biomedical Engineering, and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Dobbins, James T. [Department of Radiology and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Departments of Physics and Biomedical Engineering and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Segars, W. Paul [Department of Radiology and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States); Lo, Joseph Y. [Department of Radiology and Carl E. Ravin Advanced Imaging Laboratories, Duke University Medical Center, Durham, North Carolina 27705 and Departments of Electrical and Computer Engineering and Biomedical Engineering and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27705 (United States)

    2016-01-15

    Purpose: To create a database of highly realistic and anatomically variable 3D virtual breast phantoms based on dedicated breast computed tomography (bCT) data. Methods: A tissue classification and segmentation algorithm was used to create realistic and detailed 3D computational breast phantoms based on 230 + dedicated bCT datasets from normal human subjects. The breast volume was identified using a coarse three-class fuzzy C-means segmentation algorithm which accounted for and removed motion blur at the breast periphery. Noise in the bCT data was reduced through application of a postreconstruction 3D bilateral filter. A 3D adipose nonuniformity (bias field) correction was then applied followed by glandular segmentation using a 3D bias-corrected fuzzy C-means algorithm. Multiple tissue classes were defined including skin, adipose, and several fractional glandular densities. Following segmentation, a skin mask was produced which preserved the interdigitated skin, adipose, and glandular boundaries of the skin interior. Finally, surface modeling was used to produce digital phantoms with methods complementary to the XCAT suite of digital human phantoms. Results: After rejecting some datasets due to artifacts, 224 virtual breast phantoms were created which emulate the complex breast parenchyma of actual human subjects. The volume breast density (with skin) ranged from 5.5% to 66.3% with a mean value of 25.3% ± 13.2%. Breast volumes ranged from 25.0 to 2099.6 ml with a mean value of 716.3 ± 386.5 ml. Three breast phantoms were selected for imaging with digital compression (using finite element modeling) and simple ray-tracing, and the results show promise in their potential to produce realistic simulated mammograms. Conclusions: This work provides a new population of 224 breast phantoms based on in vivo bCT data for imaging research. Compared to previous studies based on only a few prototype cases, this dataset provides a rich source of new cases spanning a wide range

  14. Development of realistic physical breast phantoms matched to virtual breast phantoms based on human subject data

    Energy Technology Data Exchange (ETDEWEB)

    Kiarashi, Nooshin [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Nolte, Adam C. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Sturgeon, Gregory M.; Ghate, Sujata V. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Segars, William P. [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 and Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708 (United States); Nolte, Loren W. [Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 and Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Samei, Ehsan [Carl E. Ravin Advanced Imaging Laboratories, Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710 (United States); Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708 (United States); Department of Biomedical Engineering, Duke University, Durham, North Carolina 27708 (United States); Medical Physics Graduate Program, Duke University, Durham, North Carolina 27708 (United States); Department of Physics, Duke University, Durham, North Carolina 27708 (United States); and others

    2015-07-15

    Purpose: Physical phantoms are essential for the development, optimization, and evaluation of x-ray breast imaging systems. Recognizing the major effect of anatomy on image quality and clinical performance, such phantoms should ideally reflect the three-dimensional structure of the human breast. Currently, there is no commercially available three-dimensional physical breast phantom that is anthropomorphic. The authors present the development of a new suite of physical breast phantoms based on human data. Methods: The phantoms were designed to match the extended cardiac-torso virtual breast phantoms that were based on dedicated breast computed tomography images of human subjects. The phantoms were fabricated by high-resolution multimaterial additive manufacturing (3D printing) technology. The glandular equivalency of the photopolymer materials was measured relative to breast tissue-equivalent plastic materials. Based on the current state-of-the-art in the technology and available materials, two variations were fabricated. The first was a dual-material phantom, the Doublet. Fibroglandular tissue and skin were represented by the most radiographically dense material available; adipose tissue was represented by the least radiographically dense material. The second variation, the Singlet, was fabricated with a single material to represent fibroglandular tissue and skin. It was subsequently filled with adipose-equivalent materials including oil, beeswax, and permanent urethane-based polymer. Simulated microcalcification clusters were further included in the phantoms via crushed eggshells. The phantoms were imaged and characterized visually and quantitatively. Results: The mammographic projections and tomosynthesis reconstructed images of the fabricated phantoms yielded realistic breast background. The mammograms of the phantoms demonstrated close correlation with simulated mammographic projection images of the corresponding virtual phantoms. Furthermore, power

  15. Realistic modelling of the effects of asynchronous motion at the base of bridge piers

    CERN Document Server

    Romanelli, F; Vaccari, F

    2002-01-01

    Frequently long-span bridges provide deep valley crossings, which require special consideration due to the possibility of local amplification of the ground motion as a consequence of topographical irregularities and local soil conditions. This does in fact cause locally enhanced seismic input with the possibility for the bridge piers to respond asynchronously. This introduces special design requirements so that possible out-of-phase ground displacements and the associated large relative displacements of adjacent piers can be accommodated without excessive damage. Assessment of the local variability of the ground motion due to local lateral heterogeneities and to attenuation properties is thus crucial toward the realistic definition of the asynchronous motion at the base of the bridge piers. We illustrate the work done in the framework of a large international cooperation to assess the importance of non-synchronous seismic excitation of long structures. To accomplish this task we compute complete synthetic acc...

  16. Biophysically realistic filament bending dynamics in agent-based biological simulation.

    Science.gov (United States)

    Alberts, Jonathan B

    2009-01-01

    An appealing tool for study of the complex biological behaviors that can emerge from networks of simple molecular interactions is an agent-based, computational simulation that explicitly tracks small-scale local interactions--following thousands to millions of states through time. For many critical cell processes (e.g. cytokinetic furrow specification, nuclear centration, cytokinesis), the flexible nature of cytoskeletal filaments is likely to be critical. Any computer model that hopes to explain the complex emergent behaviors in these processes therefore needs to encode filament flexibility in a realistic manner. Here I present a numerically convenient and biophysically realistic method for modeling cytoskeletal filament flexibility in silico. Each cytoskeletal filament is represented by a series of rigid segments linked end-to-end in series with a variable attachment point for the translational elastic element. This connection scheme allows an empirically tuning, for a wide range of segment sizes, viscosities, and time-steps, that endows any filament species with the experimentally observed (or theoretically expected) static force deflection, relaxation time-constant, and thermal writhing motions. I additionally employ a unique pair of elastic elements--one representing the axial and the other the bending rigidity- that formulate the restoring force in terms of single time-step constraint resolution. This method is highly local -adjacent rigid segments of a filament only interact with one another through constraint forces-and is thus well-suited to simulations in which arbitrary additional forces (e.g. those representing interactions of a filament with other bodies or cross-links / entanglements between filaments) may be present. Implementation in code is straightforward; Java source code is available at www.celldynamics.org.

  17. Biophysically realistic filament bending dynamics in agent-based biological simulation.

    Directory of Open Access Journals (Sweden)

    Jonathan B Alberts

    Full Text Available An appealing tool for study of the complex biological behaviors that can emerge from networks of simple molecular interactions is an agent-based, computational simulation that explicitly tracks small-scale local interactions--following thousands to millions of states through time. For many critical cell processes (e.g. cytokinetic furrow specification, nuclear centration, cytokinesis, the flexible nature of cytoskeletal filaments is likely to be critical. Any computer model that hopes to explain the complex emergent behaviors in these processes therefore needs to encode filament flexibility in a realistic manner. Here I present a numerically convenient and biophysically realistic method for modeling cytoskeletal filament flexibility in silico. Each cytoskeletal filament is represented by a series of rigid segments linked end-to-end in series with a variable attachment point for the translational elastic element. This connection scheme allows an empirically tuning, for a wide range of segment sizes, viscosities, and time-steps, that endows any filament species with the experimentally observed (or theoretically expected static force deflection, relaxation time-constant, and thermal writhing motions. I additionally employ a unique pair of elastic elements--one representing the axial and the other the bending rigidity- that formulate the restoring force in terms of single time-step constraint resolution. This method is highly local -adjacent rigid segments of a filament only interact with one another through constraint forces-and is thus well-suited to simulations in which arbitrary additional forces (e.g. those representing interactions of a filament with other bodies or cross-links / entanglements between filaments may be present. Implementation in code is straightforward; Java source code is available at www.celldynamics.org.

  18. A GIS-based simulation architecture and prototype for realistic spectral scene generation of vegetated areas

    Science.gov (United States)

    Fink, Christopher E.; Moulton, Joseph R., Jr.; Ortalano, Michael; Helmsen, John; Soiguine, Alexander; Kaplan, Raymond; Seng, William; Haren, Raymond E.

    2004-08-01

    Vehicles concealed in highly cluttered, vegetated scene environments pose significant challenges for passive sensor systems and algorithms. System analysts working hyperspectral exploitation research require an at-aperture simulation capability that allows them to reliably investigate beyond the highly-limited scenarios that expensive field data sets afford. To be useful to the analyst, such a simulation should address the following requirements: (1) the ability to easily generate scene representations for arbitrary Earth regions of tactical interest; (2) the ability to represent scene components, like terrain, trees and bushes, to an extremely high spatial resolution for calculation of accurate multiple spectral reflections, occlusions and shadowing; (3) the ability to stimulate the 3D scene with realistic natural spectral irradiances for arbitrary 3D model atmospheres; (4) the ability to appropriately integrate constantly improving, rigorous thermal, spectral signature and atmospheric propagation models; (5) the ability to efficiently render at-aperture hyperspectral data sets in a reasonable run-time. Herein the authors describe their work toward a comprehensive ray-tracer-based simulation architecture and prototype capability that addresses these requirements. They describe their development of a GIS-based toolset for database generation, tools for 3D vegetated terrain-model development, and a prototype raytracer-based spectral scene generator.

  19. Dynamic analysis of DATE5 based on the physically realistic environmental disturbances

    Science.gov (United States)

    Wang, Hairen; Qian, Yuan; Lou, Zheng; Zuo, Yingxi; Yang, Ji; Kaercher, Hans

    2016-07-01

    The observation bands of the 5 meter Dome A Terahertz Explorer (DATE5) are primarily over the wavelength of 350 and 200 μm. However, the pointing performance of DATE5 is affected by the unsteady wind, which either acts directly on the telescope structure or transmits through the ice and foundation. According to the above performance requirements of DATE5, the pointing error caused by the wind disturbance must be less than 2 arcsec. The main influence of the disturbances acting on the telescope is forces and torques due to wind gusts. Alternating forces and torques cause displacements of the telescope as well as structural oscillations. Both effects lead to pointing errors and therefore have to be compensated as much as possible by the main axes servo controllers. Wind acting on the telescope can be treated as random event, whose expected values depend on the specific site. The wind velocity throughout a given time interval can be described as a randomly varying velocity superimposed upon a constant average or mean velocity. For the dynamic analysis, the two components are separated and only the fluctuating component is used. In this paper, the dynamic analysis (mode analysis and spectrum analysis) of DATE5 is carried out based on the physically realistic environmental disturbances of dome A.

  20. Comparison of temporal realistic telecommunication base station exposure with worst-case estimation in two countries.

    Science.gov (United States)

    Mahfouz, Zaher; Verloock, Leen; Joseph, Wout; Tanghe, Emmeric; Gati, Azeddine; Wiart, Joe; Lautru, David; Hanna, Victor Fouad; Martens, Luc

    2013-12-01

    The influence of temporal daily exposure to global system for mobile communications (GSM) and universal mobile telecommunications systems and high speed downlink packet access (UMTS-HSDPA) is investigated using spectrum analyser measurements in two countries, France and Belgium. Temporal variations and traffic distributions are investigated. Three different methods to estimate maximal electric-field exposure are compared. The maximal realistic (99 %) and the maximal theoretical extrapolation factor used to extrapolate the measured broadcast control channel (BCCH) for GSM and the common pilot channel (CPICH) for UMTS are presented and compared for the first time in the two countries. Similar conclusions are found in the two countries for both urban and rural areas: worst-case exposure assessment overestimates realistic maximal exposure up to 5.7 dB for the considered example. In France, the values are the highest, because of the higher population density. The results for the maximal realistic extrapolation factor at the weekdays are similar to those from weekend days.

  1. Microscopic calculations of elastic scattering between light nuclei based on a realistic nuclear interaction

    Energy Technology Data Exchange (ETDEWEB)

    Dohet-Eraly, Jeremy [F.R.S.-FNRS (Belgium); Sparenberg, Jean-Marc; Baye, Daniel, E-mail: jdoheter@ulb.ac.be, E-mail: jmspar@ulb.ac.be, E-mail: dbaye@ulb.ac.be [Physique Nucleaire et Physique Quantique, CP229, Universite Libre de Bruxelles (ULB), B-1050 Brussels (Belgium)

    2011-09-16

    The elastic phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions are calculated in a cluster approach by the Generator Coordinate Method coupled with the Microscopic R-matrix Method. Two interactions are derived from the realistic Argonne potentials AV8' and AV18 with the Unitary Correlation Operator Method. With a specific adjustment of correlations on the {alpha} + {alpha} collision, the phase shifts for the {alpha} + {alpha} and {alpha} + {sup 3}He collisions agree rather well with experimental data.

  2. A realistic quantum capacitance model for quantum Hall edge state based Fabry-Pérot interferometers

    Science.gov (United States)

    Kilicoglu, O.; Eksi, D.; Siddiki, A.

    2017-01-01

    In this work, the classical and the quantum capacitances are calculated for a Fabry-Pérot interferometer operating in the integer quantized Hall regime. We first consider a rotationally symmetric electrostatic confinement potential and obtain the widths and the spatial distribution of the insulating (incompressible) circular strips using a charge density profile stemming from self-consistent calculations. Modelling the electrical circuit of capacitors composed of metallic gates and incompressible/compressible strips, we investigate the conditions to observe Aharonov-Bohm (quantum mechanical phase dependent) and Coulomb blockade (capacitive coupling dependent) effects reflected in conductance oscillations. In a last step, we solve the Schrödinger and the Poisson equations self-consistently in a numerical manner taking into account realistic experimental geometries. We find that, describing the conductance oscillations either by Aharanov-Bohm or Coulomb blockade strongly depends on sample properties also other than size, therefore, determining the origin of these oscillations requires further experimental and theoretical investigation.

  3. Validity analysis of development lesson plan and student worksheet based realistic mathematics education

    Science.gov (United States)

    Zulfaneti, Rismen, Sefna; Suryani, Mulia

    2016-02-01

    The previous research showed that the teachers of the fourth grade at elementary school in West Sumatra need lesson plan and teaching materials which integrated with character education especially on mathematics subject. Teachers need teaching materials which encompasses the daily life problems (contextual) so that, it can increase students' understanding of mathematics. Realistic mathematics education is a solution to these problems. The aims of the research are to develop learning equipment, i. e lesson plan sand valid worksheets. Development model referred to the Plomp development model which consists of three phase namely preliminary research, prototyping phase, and assessment phase. However, in this research, it is only presented the results in the expert review which is in the part of prototyping phase. The instrument was the validation worksheet. Expert stated that each of lesson plan and students' worksheet were in valid criterion

  4. Realistic facial expression of virtual human based on color, sweat, and tears effects.

    Science.gov (United States)

    Alkawaz, Mohammed Hazim; Basori, Ahmad Hoirul; Mohamad, Dzulkifli; Mohamed, Farhan

    2014-01-01

    Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry) and blushing (anger and happiness) is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs) of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH) methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics.

  5. Collective multipole excitations based on correlated realistic nucleon-nucleon interactions

    Energy Technology Data Exchange (ETDEWEB)

    Paar, N. [Zagreb Univ. (Croatia). Fac. of Science, Physics Dept.; Papakonstantinou, P.; Hergert, H.; Roth, R. [Technische Univ. Darmstadt (Germany). Inst. fuer Kernphysik

    2006-05-24

    We investigate collective multipole excitations for closed shell nuclei from {sup 16}O to {sup 208}Pb using correlated realistic nucleon-nucleon interactions in the framework of the random phase approximation (RPA). The dominant short-range central and tensor correlations a re treated explicitly within the Unitary Correlation Operator Method (UCOM), which provides a phase-shift equivalent correlated interaction VUCOM adapted to simple uncorrelated Hilbert spaces. The same unitary transformation that defines the correlated interaction is used to derive correlated transition operators. Using VUCOM we solve the Hartree-Fock problem and employ the single-particle states as starting point for the RPA. By construction, the UCOM-RPA is fully self-consistent, i.e. the same correlated nucleon-nucleon interact ion is used in calculations of the HF ground state and in the residual RPA interaction. Consequently, the spurious state associated with the center-of-mass motion is properly removed and the sum-rules are exhausted within {+-}3%. The UCOM-RPA scheme results in a collective character of giant monopole, dipole, and quadrupole resonances in closed-shell nuclei across the nuclear chart. For the isoscalar giant monopole resonance, the resonance energies are in agreement with experiment hinting at a reasonable compressibility. However, in the 1{sup -} and 2{sup +} channels the resonance energies are overestimated due to missing long-range correlations and three-body contributions. (orig.)

  6. Realistic Facial Expression of Virtual Human Based on Color, Sweat, and Tears Effects

    Directory of Open Access Journals (Sweden)

    Mohammed Hazim Alkawaz

    2014-01-01

    Full Text Available Generating extreme appearances such as scared awaiting sweating while happy fit for tears (cry and blushing (anger and happiness is the key issue in achieving the high quality facial animation. The effects of sweat, tears, and colors are integrated into a single animation model to create realistic facial expressions of 3D avatar. The physical properties of muscles, emotions, or the fluid properties with sweating and tears initiators are incorporated. The action units (AUs of facial action coding system are merged with autonomous AUs to create expressions including sadness, anger with blushing, happiness with blushing, and fear. Fluid effects such as sweat and tears are simulated using the particle system and smoothed-particle hydrodynamics (SPH methods which are combined with facial animation technique to produce complex facial expressions. The effects of oxygenation of the facial skin color appearance are measured using the pulse oximeter system and the 3D skin analyzer. The result shows that virtual human facial expression is enhanced by mimicking actual sweating and tears simulations for all extreme expressions. The proposed method has contribution towards the development of facial animation industry and game as well as computer graphics.

  7. Nucleon-pair states of even-even Sn isotopes based on realistic effective interactions

    Science.gov (United States)

    Cheng, Y. Y.; Qi, C.; Zhao, Y. M.; Arima, A.

    2016-08-01

    In this paper we study yrast states of 128,126,124Sn and 104,106,108Sn by using the monopole-optimized realistic interactions in terms of both the shell model (SM) and the nucleon-pair approximation (NPA). For yrast states of 128,126Sn and 104,106Sn, we calculate the overlaps between the wave functions obtained in the full SM space and those obtained in the truncated NPA space, and find that most of these overlaps are very close to 1. Very interestingly, for most of these states with positive parity and even spin or with negative parity and odd spin, the SM wave function is found to be well represented by one nucleon-pair basis state, viz., a simple picture of "nucleon-pair states" (nucleon-pair configuration without mixings) emerges. In 128,126Sn, the positive-parity (or negative-parity) yrast states with spin J >10 (or J >7 ) are found to be well described by breaking one or two S pairs in the 101+ (or 71-) state, i.e., the yrast state of seniority-two, spin-maximum, and positive-parity (or negative-parity), into non-S pair(s). Similar regularity is also pointed out for 104,106Sn. The evolution of E 2 transition rates between low-lying states in 128,126,124Sn is discussed in terms of the seniority scheme.

  8. Realistic outcomes.

    Science.gov (United States)

    Cowan, Tracy

    2012-04-01

    Patient-centred care is one of the new mantras of nursing and medicine. However, I wonder if this is a concept we are starting to take for granted, and if our understanding of it is based more on assumptions than we'd like to admit. I've often interpreted it as the need to involve patients in decision-making and ensure they are happy with the care they receive. In short, we want their involvement and, ultimately, stamp of approval.

  9. A real-time photo-realistic rendering algorithm of ocean color based on bio-optical model

    Science.gov (United States)

    Ma, Chunyong; Xu, Shu; Wang, Hongsong; Tian, Fenglin; Chen, Ge

    2016-12-01

    A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material (CDOM), inorganic suspended particle, etc., which have different contributions to absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We establish an ocean surface transmission model based on ocean bidirectional reflectance distribution function (BRDF) and the Fresnel law, and this model's outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the reflection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit (GPU). Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.

  10. A Real-Time Photo-Realistic Rendering Algorithm of Ocean Color Based on Bio-Optical Model

    Institute of Scientific and Technical Information of China (English)

    MA Chunyong; XU Shu; WANG Hongsong; TIAN Fenglin; CHEN Ge

    2016-01-01

    A real-time photo-realistic rendering algorithm of ocean color is introduced in the paper, which considers the impact of ocean bio-optical model. The ocean bio-optical model mainly involves the phytoplankton, colored dissolved organic material (CDOM), inorganic suspended particle,etc., which have different contributions to absorption and scattering of light. We decompose the emergent light of the ocean surface into the reflected light from the sun and the sky, and the subsurface scattering light. We estab-lish an ocean surface transmission model based on ocean bidirectional reflectance distribution function (BRDF) and the Fresnel law, and this model’s outputs would be the incident light parameters of subsurface scattering. Using ocean subsurface scattering algorithm combined with bio-optical model, we compute the scattering light emergent radiation in different directions. Then, we blend the re-flection of sunlight and sky light to implement the real-time ocean color rendering in graphics processing unit (GPU). Finally, we use two kinds of radiance reflectance calculated by Hydrolight radiative transfer model and our algorithm to validate the physical reality of our method, and the results show that our algorithm can achieve real-time highly realistic ocean color scenes.

  11. Toward Simulating Realistic Pursuit-Evasion Using a Roadmap-Based Approach

    KAUST Repository

    Rodriguez, Samuel

    2010-01-01

    In this work, we describe an approach for modeling and simulating group behaviors for pursuit-evasion that uses a graph-based representation of the environment and integrates multi-agent simulation with roadmap-based path planning. We demonstrate the utility of this approach for a variety of scenarios including pursuit-evasion on terrains, in multi-level buildings, and in crowds. © 2010 Springer-Verlag Berlin Heidelberg.

  12. Microalgae-based biodiesel: economic analysis of downstream process realistic scenarios.

    Science.gov (United States)

    Ríos, Sergio D; Torres, Carmen M; Torras, Carles; Salvadó, Joan; Mateo-Sanz, Josep M; Jiménez, Laureano

    2013-05-01

    Microalgae oil has been identified as a reliable resource for biodiesel production due to its high lipid productivity and potential cultivation in non-fertile locations. However, high scale production of microalgae based biodiesel depends on the optimization of the entire process to be economically feasible. The selected strain, medium, harvesting methods, etc., sorely affects the ash content in the dry biomass which have a direct effect in the lipid content. Moreover, the suitable lipids for biodiesel production, some of the neutral/saponifiable, are only a fraction of the total ones (around 30% dry base biomass in the best case). The present work uses computational tools for the modeling of different scenarios of the harvesting, oil extraction and transesterification. This rigorous modeling approach detects process bottlenecks that could have led to an overestimation of the potentiality of the microalgae lipids as a resource for the biodiesel production.

  13. Construction of Realistic Scene in Virtual Turning Based on Global Illumination Model and Chip Simulation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the rapid development of manufacturing technology, the traditional simulation of machining can not meet the people's need. Research on virtual machining environment is one of the key parts of virtual manufacturing technology. According to the features of virtual turning, this paper proposes a simplified Whitted lighting model based on analysis of Phong and other local illumination model. This model takes the material and roughness of workpiece into account to calculate the roughness coefficient D, geom...

  14. HIGH-ENERGY ELECTRON COOLING BASED ON REALISTIC SIX-DIMENSIONAL DISTRIBUTION OF ELECTRONS

    Energy Technology Data Exchange (ETDEWEB)

    FEDOTOV,A.; BEN-ZVI, I.; ET AL.

    2007-06-25

    The high-energy electron cooling system for RHIC-II is unique compared to standard coolers. It requires bunched electron beam. Electron bunches are produced by an Energy Recovery Linac (ERL), and cooling is planned without longitudinal magnetic field. To address unique features of the RHIC cooler, a generalized treatment of cooling force was introduced in BETACOOE code which allows us to calculate friction force for an arbitrary distribution of electrons. Simulations for RHIC cooler based on electron distribution from ERL are presented.

  15. A Realistic Process Example for MIMO MPC based on Autoregressive Models

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Jørgensen, John Bagterp

    2014-01-01

    Advanced controllers such as model predictive control are i n use for a wide range of application in the process industry. The potential utili zation of such advanced predictive controllers is far from exhausted. One barrier for more wide spread implementation is the lack of simple methodologies...... for advanced control design develo pment which may be used by non experts in control theory. This paper presents and illustra tes the use of a simple methodology to design an offset-free MPC based on ARX models. Hence a mecha nistic process model is not required. The forced circulation evaporator by Newell...

  16. Cooperative Planning for UAS-based Sensor Networks In Realistic Communication Environments

    Science.gov (United States)

    Stachura, M.

    This dissertation develops a unified, tractable algorithm for distributed planning for multiple unmanned aircraft based sensor networks with performance bounds. An information-theoretic objective function is derived that incorporates sensing and communication to guide a cooperative team of unmanned aircraft. The communication is modelled with packet erasure channels for each link in a multi-hop mesh network. This objective is shown to be intractable and assumptions are made to find a tractable formulation. This tractable formulation is then distributed using the chain rule of mutual information and optimization algorithms are designed with performance bounds for different scenarios and compared against the fully centralized mutual information approach. This comparison is done analytically using submodularity under certain assumptions and Monte Carlo simulations to evaluate the algorithms when these assumptions break down. A novel unmanned aircraft system platform was developed to facilitate experiments with multiple unmanned aircraft utilizing sensing and multi-hop mesh networking. This system was used to perform localization experiments of radio frequency emitters based on the received signal strength measurement. The planning algorithms were demonstrated with multiple aircraft to show there validity and tractability on a real world scenario. These experiments were used to asses the algorithms performance showing the improvement in sensing is appreciable and specifically the benefits of utilizing multi-hop communication.

  17. Contour Detection-Based Realistic Finite-Difference-Time- Domain Models for Microwave Breast Cancer Detection

    Institute of Scientific and Technical Information of China (English)

    王梁; 肖夏; 宋航; 路红; 刘佩芳

    2016-01-01

    In this paper, a collection of three-dimensional(3D)numerical breast models are developed based on clinical magnetic resonance images(MRIs). A hybrid contour detection method is used to create the contour, and the internal space is filled with different breast tissues, with each corresponding to a specified interval of MRI pixel intensity. The developed models anatomically describe the complex tissue structure and dielectric properties in breasts. Besides, they are compatible with finite-difference-time-domain(FDTD)grid cells. Convolutional perfect matched layer(CPML)is applied in conjunction with FDTD to simulate the open boundary outside the model. In the test phase, microwave breast cancer detection simulations are performed in four models with varying radio-graphic densities. Then, confocal algorithm is utilized to reconstruct the tumor images. Imaging results show that the tumor voxels can be recognized in every case, with 2 mm location error in two low density cases and 7 mm─8 mm location errors in two high density cases, demonstrating that the MRI-derived models can characterize the indi-vidual difference between patients’ breasts.

  18. Teaching and learning based on peer review: a realistic approach in forensic sciences.

    Science.gov (United States)

    Dinis-Oliveira, Ricardo Jorge; Magalhães, Teresa

    2016-01-01

    Teaching and learning methods need a continuous upgrade in higher education. However it is also true that some of the modern methodologies do not reduce or prevent school failure. Perhaps the real limitation is the inability to identify the true reasons that may explain it or ignore/undervalue the problem. In our opinion, one of the current constraints of the teaching/learning process is the excess of and inadequate bibliography recommended by the teacher, which results in continuous student difficulties and waste of time in searching and selecting useful information. The need to change the paradigm of the teaching/learning process comes also from employers. They claim forensic experts armed with useful knowledge to face professional life. It is therefore mandatory to identify the new needs and opportunities regarding pedagogical methodologies. This article reflects on the recent importance of peer review in teaching/learning forensic sciences based on the last 10 years of pedagogical experience inseparably from the scientific activity.

  19. A Realistic Cosmological Model Based on Observations and Some Theory Developed Over the Last 90 Years

    CERN Document Server

    Burbidge, Geoffrey

    2008-01-01

    This meeting is entitled "A Century of Cosmology." But most of the papers being given here are based on work done very recently and there is really no attempt being made to critically review what has taken place in the last 90 or 100 years. Instead, in general the participants accept without question that cosmology equates to "hot big bang cosmology" with all of its bells and whistles. All of the theory and the results obtained from observations are interpreted on the assumption that this extremely popular model is the correct one, and observers feel that they have to interpret its results in terms of what this theory allows. No one is attempting to seriously test the model with a view to accepting it or ruling it out. They are aware, as are the theorists, that there are enough free parameters available to fix up almost any model of the type. The current scheme given in detail for example by Spergel et al (206, 2007) demonstrates this. How we got to this stage is never discussed, and little or no attention is...

  20. Teaching and learning based on peer review: a realistic approach in forensic sciences

    Science.gov (United States)

    Dinis-Oliveira, Ricardo Jorge; Magalhães, Teresa

    2016-01-01

    Teaching and learning methods need a continuous upgrade in higher education. However it is also true that some of the modern methodologies do not reduce or prevent school failure. Perhaps the real limitation is the inability to identify the true reasons that may explain it or ignore/undervalue the problem. In our opinion, one of the current constraints of the teaching/learning process is the excess of and inadequate bibliography recommended by the teacher, which results in continuous student difficulties and waste of time in searching and selecting useful information. The need to change the paradigm of the teaching/learning process comes also from employers. They claim forensic experts armed with useful knowledge to face professional life. It is therefore mandatory to identify the new needs and opportunities regarding pedagogical methodologies. This article reflects on the recent importance of peer review in teaching/learning forensic sciences based on the last 10 years of pedagogical experience inseparably from the scientific activity. PMID:27547377

  1. Mathematics Instructional Model Based on Realistic Mathematics Education to Promote Problem Solving Ability at Junior High School Padang

    Directory of Open Access Journals (Sweden)

    Edwin Musdi

    2016-02-01

    Full Text Available This research aims to develop a mathematics instructional model based realistic mathematics education (RME to promote students' problem-solving abilities. The design research used Plomp models, which consists of preliminary phase, development or proto-typing phase and assessment phase.  At this study, only the first two phases conducted. The first phase, a preliminary investigation, carried out with a literature study to examine the theory-based instructional learning RME model, characteristics of learners, learning management descriptions by junior high school mathematics teacher and relevant research. The development phase is done by developing a draft model (an early prototype model that consists of the syntax, the social system, the principle of reaction, support systems, and the impact and effects of instructional support. Early prototype model contain a draft model, lesson plans, worksheets, and assessments. Tesssmer formative evaluation model used to revise the model. In this study only phase of one to one evaluation conducted. In the ppreliminary phase has produced a theory-based learning RME model, a description of the characteristics of learners in grade VIII Junior High School Padang and the description of teacher teaching in the classroom. The result showed that most students were still not be able to solve the non-routine problem. Teachers did not optimally facilitate students to develop problem-solving skills of students. It was recommended that the model can be applied in the classroom.

  2. Hemodynamic Changes Caused by Flow Diverters in Rabbit Aneurysm Models: Comparison of Virtual and Realistic FD Deployments Based on Micro-CT Reconstruction.

    Science.gov (United States)

    Xu, Jinyu; Deng, Benqiang; Fang, Yibin; Yu, Ying; Cheng, Jiyong; Wang, Shengzhang; Wang, Kuizhong; Liu, Jian-Min; Huang, Qinghai

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC 0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

  3. Bending and Twisting the Embryonic Heart: A Computational Model for C-Looping Based on Realistic Geometry

    Directory of Open Access Journals (Sweden)

    Yunfei eShi

    2014-08-01

    Full Text Available The morphogenetic process of cardiac looping transforms the straight heart tube into a curved tube that resembles the shape of the future four-chambered heart. Although great progress has been made in identifying the molecular and genetic factors involved in looping, the physical mechanisms that drive this process have remained poorly understood. Recent work, however, has shed new light on this complicated problem. After briefly reviewing the current state of knowledge, we propose a relatively comprehensive hypothesis for the mechanics of the first phase of looping, termed c-looping, as the straight heart tube deforms into a c-shaped tube. According to this hypothesis, differential hypertrophic growth in the myocardium supplies the main forces that cause the heart tube to bend ventrally, while regional growth and contraction in the omphalomesenteric veins (primitive atria and compressive loads exerted by the splanchnopleuric membrane drive rightward torsion. A computational model based on realistic embryonic heart geometry is used to test this hypothesis. The behavior of the model is in reasonable agreement with available experimental data from control and perturbed embryos, offering support for our hypothesis. The results also suggest, however, that several other mechanisms contribute secondarily to normal looping, and we speculate that these mechanisms play backup roles when looping is perturbed. Finally, some outstanding questions are discussed for future study.

  4. Mathematics Literacy on Problem Based Learning with Indonesian Realistic Mathematics Education Approach Assisted E-Learning Edmodo

    Science.gov (United States)

    Wardono; Waluya, S. B.; Mariani, Scolastika; Candra D, S.

    2016-02-01

    This study aims to find out that there are differences in mathematical literacy ability in content Change and Relationship class VII Junior High School 19, Semarang by Problem Based Learning (PBL) model with an Indonesian Realistic Mathematics Education (called Pendidikan Matematika Realistik Indonesia or PMRI in Indonesia) approach assisted Elearning Edmodo, PBL with a PMRI approach, and expository; to know whether the group of students with learning PBL models with PMRI approach and assisted E-learning Edmodo can improve mathematics literacy; to know that the quality of learning PBL models with a PMRI approach assisted E-learning Edmodo has a good category; to describe the difficulties of students in working the problems of mathematical literacy ability oriented PISA. This research is a mixed methods study. The population was seventh grade students of Junior High School 19, Semarang Indonesia. Sample selection is done by random sampling so that the selected experimental class 1, class 2 and the control experiment. Data collected by the methods of documentation, tests and interviews. From the results of this study showed average mathematics literacy ability of students in the group PBL models with a PMRI approach assisted E-learning Edmodo better than average mathematics literacy ability of students in the group PBL models with a PMRI approach and better than average mathematics literacy ability of students in the expository models; Mathematics literacy ability in the class using the PBL model with a PMRI approach assisted E-learning Edmodo have increased and the improvement of mathematics literacy ability is higher than the improvement of mathematics literacy ability of class that uses the model of PBL learning with PMRI approach and is higher than the improvement of mathematics literacy ability of class that uses the expository models; The quality of learning using PBL models with a PMRI approach assisted E-learning Edmodo have very good category.

  5. RAMESES publication standards: realist syntheses

    Directory of Open Access Journals (Sweden)

    Wong Geoff

    2013-01-01

    Full Text Available Abstract Background There is growing interest in realist synthesis as an alternative systematic review method. This approach offers the potential to expand the knowledge base in policy-relevant areas - for example, by explaining the success, failure or mixed fortunes of complex interventions. No previous publication standards exist for reporting realist syntheses. This standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards project. The project's aim is to produce preliminary publication standards for realist systematic reviews. Methods We (a collated and summarized existing literature on the principles of good practice in realist syntheses; (b considered the extent to which these principles had been followed by published syntheses, thereby identifying how rigor may be lost and how existing methods could be improved; (c used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, realist research, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d provided real-time support to ongoing realist syntheses and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e synthesized expert input, evidence syntheses and real-time problem analysis into a definitive set of standards. Results We identified 35 published realist syntheses, provided real-time support to 9 on-going syntheses and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature and common questions and challenges into briefing materials for the Delphi panel, comprising 37 members. Within three rounds this panel had reached consensus on 19 key publication standards, with an overall response rate of 91%. Conclusion This project used multiple

  6. Self-healing vs. Crack-like Rupture Propagation in Presence of Thermal Weakening Processes Based on Realistic Physical Properties

    Science.gov (United States)

    Noda, H.; Dunham, E. M.; Rice, J. R.

    2006-12-01

    We have conducted rupture propagation simulations allowing for the combined effects of thermal pressurization of pore fluid and flash heating of microscopic contact asperities. Rapid, large slip as in earthquakes produces a large amount of frictional heat, and probably activates such thermal weakening mechanisms. They act until macroscopic fault temperature T nears the melting point, and are coupled through T and macroscopic fault surface pore pressure p. Because we consider two mechanisms, the characteristic slip for each of them is physically important; a compromise on one of them can eventually nullify its effect compared to the other. We use a range of realistic hydraulic properties for thermal pressurization (hydro-thermal diffusivity factor 20-450 mm2/s; factor corresponds to f2VL_*/4=(ρ c/Λ)2(√{αth}+√{αhy})2 [Rice, JGR, 2006] where f is the friction coefficient, V is slip rate, L_* is a characteristic slip defined in the thermal pressurization analysis, ρ c is specific heat, Λ is pore pressure rise per unit temperature rise in undrained conditions, and αth and αhy are thermal and hydraulic diffusivities), and microns of contact evolution distance L for flash heating with a slip law formulation and the direct effect. We use the spectral implementation of the BIE method for elastodynamic calculations, and set a 1d FD grid normal to the fault plane at each node to calculate local heat and fluid transport assuming an infinitesimally thin slipping plane. We also use a multi-step time increment procedure by setting longer steps for slip history storage and shorter steps for integration of state variable, T, and p. Elasticity and the constitutive relation are solved simultaneously at every shorter time step with linearly interpolated stress transfer. This method reduces the amount of memory but produces numerical stability. We nucleated rupture by adding a sudden perturbation to the shear stress, which is initially uniform and much lower than the static

  7. Combining cell-based hydrodynamics with hybrid particle-field simulations: efficient and realistic simulation of structuring dynamics.

    Science.gov (United States)

    Sevink, G J A; Schmid, F; Kawakatsu, T; Milano, G

    2017-02-22

    We have extended an existing hybrid MD-SCF simulation technique that employs a coarsening step to enhance the computational efficiency of evaluating non-bonded particle interactions. This technique is conceptually equivalent to the single chain in mean-field (SCMF) method in polymer physics, in the sense that non-bonded interactions are derived from the non-ideal chemical potential in self-consistent field (SCF) theory, after a particle-to-field projection. In contrast to SCMF, however, MD-SCF evolves particle coordinates by the usual Newton's equation of motion. Since collisions are seriously affected by the softening of non-bonded interactions that originates from their evaluation at the coarser continuum level, we have devised a way to reinsert the effect of collisions on the structural evolution. Merging MD-SCF with multi-particle collision dynamics (MPCD), we mimic particle collisions at the level of computational cells and at the same time properly account for the momentum transfer that is important for a realistic system evolution. The resulting hybrid MD-SCF/MPCD method was validated for a particular coarse-grained model of phospholipids in aqueous solution, against reference full-particle simulations and the original MD-SCF model. We additionally implemented and tested an alternative and more isotropic finite difference gradient. Our results show that efficiency is improved by merging MD-SCF with MPCD, as properly accounting for hydrodynamic interactions considerably speeds up the phase separation dynamics, with negligible additional computational costs compared to efficient MD-SCF. This new method enables realistic simulations of large-scale systems that are needed to investigate the applications of self-assembled structures of lipids in nanotechnologies.

  8. The ASTROID Simulator Software Package: Realistic Modelling of High-Precision High-Cadence Space-Based Imaging

    CERN Document Server

    Marcos-Arenal, P; De Ridder, J; Huygen, R; Aerts, C

    2014-01-01

    The preparation of a space-mission that carries out any kind of imaging to detect high-precision low-amplitude variability of its targets requires a robust model for the expected performance of its instruments. This model cannot be derived from simple addition of noise properties due to the complex interaction between the various noise sources. While it is not feasible to build and test a prototype of the imaging device on-ground, realistic numerical simulations in the form of an end-to-end simulator can be used to model the noise propagation in the observations. These simulations not only allow studying the performance of the instrument, its noise source response and its data quality, but also the instrument design verification for different types of configurations, the observing strategy and the scientific feasibility of an observing proposal. In this way, a complete description and assessment of the objectives to expect from the mission can be derived. We present a high-precision simulation software packag...

  9. Development of realistic environmental release factors based on measured data: approach and lessons from the EU metal industry.

    Science.gov (United States)

    Verdonck, Frederik A M; Van Assche, Frank; Hicks, Keegan; Mertens, Jelle; Voigt, Astrid; Verougstraete, Violaine

    2014-10-01

    The assessment of environmental exposure and risks associated with the production or use of a substance on an industrial site includes the estimation of the releases to the environment. In the absence of measured release data on the specific substance, a risk assessor would rely on default release factors to the environmental compartments as developed in international, national, or regional context. Because a wide variety of substances, processes, and uses has to be covered, default release factors are as a rule conservative, usually leading to significant overprediction of releases and hence to overpredicted environmental exposure concentrations and risks. In practice, unrealistic and worst-case predictions do not support a more efficient management of releases and risk. The objective of this article is to propose a more realistic approach to characterize the environmental releases from manufacture, processing, and downstream uses of the metals and their compounds. Although developed in the European Union (EU), this approach can also be used in other regions and in other chemical management systems addressing metals. A database consisting of more than 1300 recent (1993-2010), site-specific measured release factors to air and water of 18 different metals from various EU Member States was compiled and used to calculate average and reasonable worst-case release factors for multiple metal manufacture and industrial use processes. The parameters influencing releases to water were found to depend predominantly on life cycle step (manufacture and/or use), the sector and/or the solid-water partition coefficient (K(d)). The release factors can be used as advanced tier instrument in environmental safety assessments, increasing the realism of the estimates while still keeping a sufficient level of conservatism.

  10. Self-replication of chemical systems based on recognition within a double or a triple helix - A realistic hypothesis

    Science.gov (United States)

    Kanavarioti, Anastassia

    1992-01-01

    A scenario is proposed for the non-enzymatic self-replication of short RNA molecules. The self-replication of an oligopyrimidine strand is considered and the process of template-directed synthesis based on recognition within a double helix is discussed. Replication mechanisms are suggested for selected oligonucleotides. The mechanisms are based on Watson-Crick base pairing between complementary nucleotides as well as Hoogsteen base pairing between a duplex and the complementary third strand. It is suggested that self-replication based on these mechanisms may be accomplished but may result in a substantial amount of misinformation transfer when mixed oligonucleotides are used.

  11. SiC-based neutron detector in quasi-realistic working conditions: efficiency and stability at room and high temperature under fast neutron irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Ferone, Raffaello; Issa, Fatima; Ottaviani, Laurent; Biondo, Stephane; Vervisch, Vanessa [IM2NP, UMR CNRS 7334, Aix-Marseille University, Case 231,13397 Marseille Cedex 20, (France); Szalkai, Dora; Klix, Axel [KIT- Karlsruhe Institute of Technology, Institute of Neutron Physics and Reactor Technology Karlsruhe 76344, (Germany); Vermeeren, Ludo [SCK-CEN, Boeretang 200, B-2400 Mol, (Belgium); Saenger, Richard [Schlumberger, Clamart, (France); Lyoussi, Abadallah [CEA, DEN, Departement d' Etudes des Reacteurs, Service de Physique Experimentale, Laboratoire Dosimetrie Capteurs Instrumentation, 13108 Saint-Paul-lez-Durance, (France)

    2015-07-01

    In the framework of the European I SMART project, we have designed and made new SiC-based nuclear radiation detectors able to operate in harsh environments and to detect both fast and thermal neutrons. In this paper, we report experimental results of fast neutron irradiation campaign at high temperature (106 deg. C) in quasi-realistic working conditions. Our device does not suffer from high temperature, and spectra do show strong stability, preserving features. These experiments, as well as others in progress, show the I SMART SiC-based device skills to operate in harsh environments, whereas other materials would strongly suffer from degradation. Work is still demanded to test our device at higher temperatures and to enhance efficiency in order to make our device fully exploitable from an industrial point of view. (authors)

  12. Stability of realistic strange stars (RSS)

    CERN Document Server

    Bhowmick, S; Dey, M; Ray, S; Ray, R; Bhowmick, Siddhartha; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Ray, Ranjan

    2001-01-01

    Strange stars (SS) calculated from a realistic equation of state (EOS) are very stable, for example under fast rotation but have a soft surface, on which ripples may occur when radiation is emitted close to it. We suggest this as a natural explanation of the fluctuations observed in the intensity profile of X-ray pulsars. In contrast, SS based on EOS derived from the bag models (Bag SS) are less stable against fast rotation and do not have a hard surface and cannot explain these ripples. There are other important differences between Bag SS and the SS, based on a realistic EOS, which we call realistic strange stars (RSS).

  13. Kuhn: Realist or Antirealist?

    Directory of Open Access Journals (Sweden)

    Michel Ghins

    1998-06-01

    Full Text Available Although Kuhn is much more an antirealist than a realist, the earlier and later articulations of realist and antirealist ingredients in his views merit close scrutiny. What are the constituents of the real invariant World posited by Kuhn and its relation to the mutable paradigm-related worlds? Various proposed solutions to this problem (dubbed the "new-world problem" by Ian Hacking are examined and shown to be unsatisfactory. In The Structure of Scientific Revolutions, the stable World can reasonably be taken to be made up of ordinary perceived objects, whereas in Kuhn's later works the transparadigmatic World is identified with something akin to the Kantian world-in-itself. It is argued that both proposals are beset with insuperable difficulties which render Kuhn's earlier and later versions of antirealism implausible.

  14. Modelling hen harrier dynamics to inform human-wildlife conflict resolution: a spatially-realistic, individual-based approach.

    Directory of Open Access Journals (Sweden)

    Johannes P M Heinonen

    Full Text Available Individual-based models have gained popularity in ecology, and enable simultaneous incorporation of spatial explicitness and population dynamic processes to understand spatio-temporal patterns of populations. We introduce an individual-based model for understanding and predicting spatial hen harrier (Circus cyaneus population dynamics in Great Britain. The model uses a landscape with habitat, prey and game management indices. The hen harrier population was initialised according to empirical census estimates for 1988/89 and simulated until 2030, and predictions for 1998, 2004 and 2010 were compared to empirical census estimates for respective years. The model produced a good qualitative match to overall trends between 1989 and 2010. Parameter explorations revealed relatively high elasticity in particular to demographic parameters such as juvenile male mortality. This highlights the need for robust parameter estimates from empirical research. There are clearly challenges for replication of real-world population trends, but this model provides a useful tool for increasing understanding of drivers of hen harrier dynamics and focusing research efforts in order to inform conflict management decisions.

  15. Is it possible to use highly realistic virtual reality in the elderly? A feasibility study with image-based rendering

    Directory of Open Access Journals (Sweden)

    Benoit M

    2015-03-01

    Full Text Available Michel Benoit,1,2 Rachid Guerchouche,3 Pierre-David Petit,1 Emmanuelle Chapoulie,3 Valeria Manera,1 Gaurav Chaurasia,3 George Drettakis,3 Philippe Robert1,4 1EA CoBTeK/IA, University of Nice Sophia Antipolis, 2Clinique de Psychiatrie, Pole des Neurosciences Cliniques, CHU de Nice, 3Institut National de Recherche en Informatique et en Automatique, Sophia-Antipolis, 4Centre Mémoire de Ressources et de Recherche, CHU de Nice, Nice, France Background: Virtual reality (VR opens up a vast number of possibilities in many domains of therapy. The primary objective of the present study was to evaluate the acceptability for elderly subjects of a VR experience using the image-based rendering virtual environment (IBVE approach and secondly to test the hypothesis that visual cues using VR may enhance the generation of autobiographical memories.Methods: Eighteen healthy volunteers (mean age 68.2 years presenting memory complaints with a Mini-Mental State Examination score higher than 27 and no history of neuropsychiatric disease were included. Participants were asked to perform an autobiographical fluency task in four conditions. The first condition was a baseline grey screen, the second was a photograph of a well-known location in the participant’s home city (FamPhoto, and the last two conditions displayed VR, ie, a familiar image-based virtual environment (FamIBVE consisting of an image-based representation of a known landmark square in the center of the city of experimentation (Nice and an unknown image-based virtual environment (UnknoIBVE, which was captured in a public housing neighborhood containing unrecognizable building fronts. After each of the four experimental conditions, participants filled in self-report questionnaires to assess the task acceptability (levels of emotion, motivation, security, fatigue, and familiarity. CyberSickness and Presence questionnaires were also assessed after the two VR conditions. Autobiographical memory was assessed

  16. Monte-Carlo Simulations of Spin-Crossover Phenomena Based on a Vibronic Ising-like Model with Realistic Parameters

    CERN Document Server

    Ye, Hong-zhou; Jiang, Hong

    2014-01-01

    Materials with spin-crossover (SCO) properties hold great potentials in information storage and therefore have received a lot of concerns in the recent decades. The hysteresis phenomena accompanying SCO is attributed to the intermolecular cooperativity whose underlying mechanism may have a vibronic origin. In this work, a new vibronic Ising-like model in which the elastic coupling between SCO centers is included by considering harmonic stretching and bending (SAB) interactions is proposed and solved by Monte Carlo simulations. The key parameters in the new model, $k_1$ and $k_2$, corresponding to the elastic constant of the stretching and bending mode, respectively, can be directly related to the macroscopic bulk and shear modulus of the material in study, which can be readily estimated either based on experimental measurements or first-principles calculations. The convergence issue in the MC simulations of the thermal hysteresis has been carefully checked, and it was found that the stable hysteresis loop can...

  17. A realistic EU vision of a lignite-based energy system in transition: Case study of Serbia

    Directory of Open Access Journals (Sweden)

    Batas-Bjelić Ilija

    2015-01-01

    Full Text Available Several Contracting Parties to the Treaty establishing the Energy Community of the South East Europe, currently in energy transition, have electricity production dominantly based on lignite which contrasts their new reality. Planning approach to designing a new feasible energy policy is presented in this paper. This novel approach in using EnergyPLAN tool stems from analysis of market operation of lignite thermal power plants on hourly basis, and quantification of the feasibility of the energy policy and its alignment with EU vision, and is presented in few scenarios. It was found out that the Serbian energy system is highly sensitive to the electricity market and CO2 tax increase, because the marginal costs for lignite generation will increase to more than 50€/MWh. Shifting in the merit order will be observed even at lower CO2 tax levels, because of the intensity of the emission of the electricity sector (calculated to be higher than 700gCO2/kWhel, according to current energy policy. Based on the increased use of renewable energy sources and more efficient energy conversion technologies, socio-economic and energy policy feasibility would be increased, while long-term marginal costs would be improved by 2€/MWh and emission intensity by 258 gCO2/kWhel, compared to the current energy policy. These contributions, shown in the Serbian case, are of general importance for other lignite dominated Contracting Parties to Treaty establishing the Energy Community. [Projekat Ministartsva nauke Republike Srbije, br. 42009

  18. Teaching and learning based on peer review: a realistic approach in forensic sciences [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Ricardo Jorge Dinis-Oliveira

    2016-05-01

    Full Text Available Teaching and learning methods need a continuous upgrade in higher education. However it is also true that some of the modern methodologies do not reduce or prevent school failure. Perhaps the real limitation is the inability to identify the true reasons that may explain it or ignore/undervalue the problem. In our opinion, one of the current constraints of the teaching/learning process is the excess of and inadequate bibliography recommended by the teacher, which results in continuous student difficulties and waste of time in searching and selecting useful information. The need to change the paradigm of the teaching/learning process comes also from employers. They claim forensic experts armed with useful knowledge to face professional life. It is therefore mandatory to identify the new needs and opportunities regarding pedagogical methodologies. This article reflects on the recent importance of peer review in teaching/learning forensic sciences based on the last 10 years of pedagogical experience inseparably from the scientific activity.

  19. The need for a life-cycle based aging paradigm for nanomaterials: importance of real-world test systems to identify realistic particle transformations

    Science.gov (United States)

    Mitrano, Denise M.; Nowack, Bernd

    2017-02-01

    Assessing the risks of manufactured nanomaterials (MNM) has been almost exclusively focused on the pristine, as-produced materials with far fewer studies delving into more complex, real world scenarios. However, when considering a life-cycle perspective, it is clear that MNM released from commercial products during manufacturing, use and disposal are far more relevant both in terms of more realistic environmental fate and transport as well as environmental risk. The quantity in which the particles are released and their (altered) physical and chemical form should be identified and it is these metrics that should be used to assess the exposure and hazard the materials pose. The goal of this review is to (1) provide a rationale for using a life-cycle based approach when dealing with MNM transformations, (2) to elucidate the different chemical and physical forces which age and transform MNM and (3) assess the pros and cons of current analytical techniques as they pertain to the measurement of aged and transformed MNM in these complex release scenarios. Specifically, we will describe the possible transformations common MNM may undergo during the use or disposal of nano-products based on how these products will be used by the consumer by taking stock of the current nano-enabled products on the market. Understanding the impact of these transformations may help forecast the benefits and/or risks associated with the use of products containing MNM.

  20. A 3D self-organizing multicellular epidermis model of barrier formation and hydration with realistic cell morphology based on EPISIM

    Science.gov (United States)

    Sütterlin, Thomas; Tsingos, Erika; Bensaci, Jalil; Stamatas, Georgios N.; Grabe, Niels

    2017-01-01

    The epidermis and the stratum corneum (SC) as its outermost layer have evolved to protect the body from evaporative water loss to the environment. To morphologically represent the extremely flattened cells of the SC - and thereby the epidermal barrier - in a multicellular computational model, we developed a 3D biomechanical model (BM) based on ellipsoid cell shapes. We integrated the BM in the multicellular modelling and simulation platform EPISIM. We created a cell behavioural model (CBM) with EPISIM encompassing regulatory feedback loops between the epidermal barrier, water loss to the environment, and water and calcium flow within the tissue. This CBM allows a small number of stem cells to initiate self-organizing epidermal stratification, yielding the spontaneous emergence of water and calcium gradients comparable to experimental data. We find that the 3D in silico epidermis attains homeostasis most quickly at high ambient humidity, and once in homeostasis the epidermal barrier robustly buffers changes in humidity. Our model yields an in silico epidermis with a previously unattained realistic morphology, whose cell neighbour topology is validated with experimental data obtained from in vivo images. This work paves the way to computationally investigate how an impaired SC barrier precipitates disease. PMID:28262741

  1. Realistic Visualization of Virtual Views

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    that can be impractical and sometime impossible. In addition, the artificial nature of data often makes visualized virtual scenarios not realistic enough. Not realistic in the sense that a synthetic scene is easy to discriminate visually from a natural scene. A new field of research has consequently...

  2. Realistic applications of CNTs

    Directory of Open Access Journals (Sweden)

    John Robertson

    2004-10-01

    Full Text Available Carbon nanotubes (CNTs are a fascinating subject for curiosity-driven research. But will they give rise to commercially viable applications? CNTs are rolled up sheets of sp2; bonded graphite with no surface broken bonds. Their possible applications1,2; arise from the remarkable properties of single-walled nanotubes (SWNTs such as the highest Young's modulus, highest thermal conductivity, ballistic electron transport, and high aspect ratio structure. To date, development of nanotube-based products has been delayed by a lack of availability of quantities of material and lack of control of their growth. Supplies of multi-walled nanotubes (MWNTs or nanofibers have been available from Hyperion Catalysis International, but under constraint and only as preformed composites. The supply situation is now improving with several firms producing on a larger scale, such as CNI, Showa Denko, Thomas Swan, and Nanocyl. Now is, therefore, a good time to look at applications from a more business view.

  3. Realistic level density calculation for heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Cerf, N. [Institut de Physique Nucleaire, Orsay (France); Pichon, B. [Observatoire de Paris, Meudon (France); Rayet, M.; Arnould, M. [Institut d`Astronomie et d`Astrophysique, Bruxelles (Belgium)

    1994-12-31

    A microscopic calculation of the level density is performed, based on a combinatorial evaluation using a realistic single-particle level scheme. This calculation relies on a fast Monte Carlo algorithm, allowing to consider heavy nuclei (i.e., large shell model spaces) which could not be treated previously in combinatorial approaches. An exhaustive comparison of the predicted neutron s-wave resonance spacings with experimental data for a wide range of nuclei is presented.

  4. Humanoid robot simulator: a realistic dynamics approach

    OpenAIRE

    Lima, José; Gonçalves, José; Costa, Paulo; Moreira, António

    2008-01-01

    This paper describes a humanoid robot simulator with realistic dynamics. As simulation is a powerful tool for speeding up the control software development, the suggested accurate simulator allows to accomplish this goal. The simulator, based on the Open Dynamics Engine and GLScene graphics library, provides instant visual feedback and allows the user to test any control strategy without damaging the real robot in the early stages of the development. The proposed simulator also captures some c...

  5. Realistic Behaviour Simulation of a Humanoid Robot

    OpenAIRE

    2008-01-01

    This paper describes a humanoid robot simulator with realistic dynamics. As simulation is a powerful tool for speeding up the control software development, the proposed accurate simulator allows to fulfil this goal. The simulator is based on the Open Dynamics Engine and GLScene graphics library, providing instant visual feedback. User is able to test any control strategy without bringing damage to the real robot in the early stages of the development. The proposed simulator also captures some...

  6. Time management: a realistic approach.

    Science.gov (United States)

    Jackson, Valerie P

    2009-06-01

    Realistic time management and organization plans can improve productivity and the quality of life. However, these skills can be difficult to develop and maintain. The key elements of time management are goals, organization, delegation, and relaxation. The author addresses each of these components and provides suggestions for successful time management.

  7. Assessment and realistic mathematics education

    NARCIS (Netherlands)

    Heuvel-Panhuizen, M.H.A.M. van den

    1996-01-01

    This book describes the consequences of Realistic Mathematics Education (RME) for assessing students’ understanding of mathematics in primary school. RME is the Dutch answer to the worldwide need to reform mathematics education. Changed ideas about mathematics as a school subject, its goals, ideas a

  8. INCREASED CAPACITY OF THE UNDERSTANDING OF THE CONCEPT AND THE ABILITY TO SOLVE PROBLEMS THROUGH THE IMPLEMENTATION OF THE MODEL OF TEACHING MATHEMATICS REALISTIC BASED ON COGNITIVE CONFLICT STUDENTS

    Directory of Open Access Journals (Sweden)

    Dewi Herawaty

    2016-10-01

    Full Text Available This research aims at: 1 the influence of the implementation of the model of teaching mathematics realistic based on cognitive conflict students to the ability to understanding the concept and troubleshooting capabilities; 2 determine the larger capacity of the understanding of the concept through the implementation of the model of teaching mathematics realistic based on cognitive conflict junior secondary school students the City of Bengkulu. 3 determine the great improvement of the ability to solve problems through the implementation of the model of teaching mathematics realistic based on cognitive conflict SMP students Bengkulu City.To achieve the goal of this research is to apply Research Design pseudo experiments with research design Pretest-Postest Nonequivalent Control Group Design, with the test instrument the ability to understanding the concept and test the troubleshooting capabilities. The data has been analyzed using the test gains. The results of this research is 1 the ability of understanding the concept and troubleshooting class experiment the given learning with PMR is better than with the ability to understanding the concept and troubleshooting control classes assigned to conventional mathematics lesson; 2 increase the ability of the understanding of the concept through the implementation of the model of teaching mathematics based on cognitive conflict SMP students Bengkulu City is significant with the index gain of 0,755 (high-level; 3 increase the ability to solve problems through the implementation of the model of teaching mathematics based on cognitive conflict SMP students Bengkulu City is significant with the index gain of 0,500 level (is.

  9. True-to-Life? Realistic Fiction.

    Science.gov (United States)

    Jordan, Anne Devereaux

    1995-01-01

    Suggests that modern realistic fiction for young readers is intensely moralistic and directive at the spoken and unspoken behest of the adults who write, select, and buy that literature. Discusses moral tales, early realistic fiction, modern realistic fiction, and choosing realistic fiction. (RS)

  10. Simple and Realistic Data Generation

    DEFF Research Database (Denmark)

    Pedersen, Kenneth Houkjær; Torp, Kristian; Wind, Rico

    2006-01-01

    This paper presents a generic, DBMS independent, and highly extensible relational data generation tool. The tool can efficiently generate realistic test data for OLTP, OLAP, and data streaming applications. The tool uses a graph model to direct the data generation. This model makes it very simple...... to generate data even for large database schemas with complex inter- and intra table relationships. The model also makes it possible to generate data with very accurate characteristics....

  11. Assessment and realistic mathematics education

    OpenAIRE

    Heuvel-Panhuizen, M.H.A.M. van den

    1996-01-01

    This book describes the consequences of Realistic Mathematics Education (RME) for assessing students’ understanding of mathematics in primary school. RME is the Dutch answer to the worldwide need to reform mathematics education. Changed ideas about mathematics as a school subject, its goals, ideas about teaching and learning mathematics, require new forms of assessment. Within RME this means a preference for observation and individual interviews. However, written tests have not been abandoned...

  12. Dynamical Symmetries Reflected in Realistic Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Sviratcheva, K.D.; Draayer, J.P.; /Louisiana State U.; Vary, J.P.; /Iowa State U. /LLNL, Livermore /SLAC

    2007-04-06

    Realistic nucleon-nucleon (NN) interactions, derived within the framework of meson theory or more recently in terms of chiral effective field theory, yield new possibilities for achieving a unified microscopic description of atomic nuclei. Based on spectral distribution methods, a comparison of these interactions to a most general Sp(4) dynamically symmetric interaction, which previously we found to reproduce well that part of the interaction that is responsible for shaping pairing-governed isobaric analog 0{sup +} states, can determine the extent to which this significantly simpler model Hamiltonian can be used to obtain an approximate, yet very good description of low-lying nuclear structure. And furthermore, one can apply this model in situations that would otherwise be prohibitive because of the size of the model space. In addition, we introduce a Sp(4) symmetry breaking term by including the quadrupole-quadrupole interaction in the analysis and examining the capacity of this extended model interaction to imitate realistic interactions. This provides a further step towards gaining a better understanding of the underlying foundation of realistic interactions and their ability to reproduce striking features of nuclei such as strong pairing correlations or collective rotational motion.

  13. Performance Evaluation of 802.11p-Based Ad Hoc Vehicle-to-Vehicle Communications for Usual Applications Under Realistic Urban Mobility

    Directory of Open Access Journals (Sweden)

    Patrick Sondi

    2016-05-01

    Full Text Available In vehicular ad hoc networks, participating vehicles organize themselves in order to support lots of emerging applications. While network infrastructure can be dimensioned correctly in order to provide quality of service support to both vehicle-to-vehicle and vehicle-to-infrastructure communications, there are still many issues to achieve the same performance using only ad hoc vehicle-to-vehicle communications. This paper investigates the performance of such communications for complete applications including their specific packet size, packet acknowledgement mechanisms and quality of service requirements. The simulation experiments are performed using Riverbed (OPNET Modeler on a network topology made of 50 nodes equipped with IEEE 802.11p technology and following realistic trajectories in the streets of Paris at authorized speeds. The results show that almost all application types are well supported, provided that the source and the destination have a direct link. Particularly, it is pointed out that introducing supplementary hops in a communication has more effects on end-to-end delay and loss rate rather than mobility of the nodes. The study also shows that ad hoc reactive routing protocols degrade performance by increasing the delays while proactive ones introduce the same counter performance by increasing the network load with routing traffic. Whatever the routing protocol adopted, the best performance is obtained only while small groups of nodes communicate using at most two-hop routes.

  14. Realistic Visualization of Virtual Views and Virtual Cinema

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Visualization is a new field of research which has received increasing attention in recent years. It is strictly related to the increased popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer...... is then gaining consensus: the augmented actor. Fundamental concepts and examples of methods proposed for realistic view synthesis, based on the transfer of photorealism from reference photographs to novel views, will be presented. The application of methods for realistic image synthesis to virtual cinematography...

  15. Photo-Realistic Image Synthesis and Virtual Cinematography

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Synthesis is a new field of research that has received increasing attention in recent years. It is strictly related to the grown popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer generated......: the augmented actor. Fundamental concepts and examples of methods proposed for realistic view synthesis based on the transfer of photo-realism from reference photographs to novel views, will be presented. The application of methods for realistic image synthesis to virtual cinematography will also be illustrated...

  16. Cellular automaton for realistic modelling of landslides

    CERN Document Server

    Segrè, E; Enrico Segre; Chiara Deangeli

    1994-01-01

    We develop a numerical model for the simulation of debris flow in landslides over a complex three dimensional topography. The model is based on a lattice, in which debris can be transferred among nearest neighbours according to established empirical relationships for granular flows. The model is validated comparing its results with reported field data. Our model is in fact a realistic elaboration of simpler ``sandpile automata'', which have in recent years been studied as supposedly paradigmatic of ``self organized criticality''. Statistics and scaling properties of the simulation are examined, showing that the model has an intermittent behaviour.

  17. Simulating realistic enough patient records.

    Science.gov (United States)

    Cunningham, James; Ainsworth, John

    2015-01-01

    Information systems for storing, managing and manipulating electronic medical records must place an emphasis on maintaining the privacy and security of those records. Though the design, development and testing of such systems also requires the use of data, the developers of these systems, rarely also their final end users, are unlikely to have ethical or governance approval to use real data. Alternative test data is commonly either randomly produced or taken from carefully anonymised subsets of records. In both cases there are potential shortcomings that can impact on the quality of the product being developed. We have addressed these shortcomings with a tool and methodology for efficiently simulating large amounts of realistic enough electronic patient records which can underpin the development of data-centric electronic healthcare systems.

  18. SEMICONDUCTOR DEVICES Performance optimization of MOS-like carbon nanotube-FETs with realistic source/drain contacts based on electrostatic doping

    Science.gov (United States)

    Hailiang, Zhou; Yue, Hao; Minxuan, Zhang

    2010-12-01

    Due to carrier band-to-band-tunneling (BTBT) through channel-source/drain contacts, conventional MOS-like Carbon Nanotube Field Effect Transistors (C-CNFETs) suffer from ambipolar conductance, which deteriorates the device performance greatly. In order to reduce such ambipolar behavior, a novel device structure based on electrostatic doping is proposed and all kinds of source/drain contacting conditions are considered in this paper. The non-equilibrium Green's function (NEGF) formalism based simulation results show that, with proper choice of tuning voltage, such electrostatic doping strategy can not only reduce the ambipolar conductance but also improve the sub-threshold performance, even with source/drain contacts being of Schottky type. And these are both quite desirable in circuit design to reduce the system power and improve the frequency as well. Further study reveals that the performance of the proposed design depends strongly on the choice of tuning voltage value, which should be paid much attention to obtain a proper trade-off between power and speed in application.

  19. Constructing probabilistic models for realistic velocity distributions based on forward modeling and tomographic inversion: applications for active and passive source observation schemes

    Science.gov (United States)

    Koulakov, I. Yu.

    2009-04-01

    Seismic tomography is like a photography taken by a camera with deformed and blurred lenses. In the resulting tomograms, colors (amplitudes of anomalies) and shapes of objects are often strongly biased and are usually not representing the reality. We propose an approach which allows investigating properties of the "camera" and retrieving most probable shapes and amplitudes of anomalies in the real Earth. The main idea of this approach is to construct a synthetic model which, after performing forward modeling and tomographic inversion, reproduces the same amplitudes and shapes of patterns as after inversion of observed data. In this modeling, the conditions of the tomographic inversion (damping, grid spacing, source location parameters etc) should be absolutely identical to the case of the observed data processing. The a priori information, if available any, should be taken into account in this modeling to decrease the uncertainty related to fundamental non-uniqueness of the inversion problem. In the talk, several examples of applying this approach at various scales for different data schemes are presented: (1) regional scheme which uses the global data of the ISC catalogue (with examples of regional upper mantle models in Europe and central Asia); (2) local earthquake tomography scheme (illustrated with models in Toba caldera area and in Central Java); (3) seismic profiling which is based on active source refraction travel time data (with examples of several deep seismic sounding profiles in Central Pacific and subduction zones in Chile).

  20. Breaking with fun, educational and realistic learning games

    DEFF Research Database (Denmark)

    Duus Henriksen, Thomas

    2009-01-01

    between the game and other didactic activities that formed the learning process; and, the game might have been intended to be realistic, but it was in the gaps where this realism was critically assessed that learned understanding was forged. While thinking learning games as fun, educative and realistic......This paper addresses the game conceptions and values that learning games inherit from regular gaming, as well as how they affect the use and development of learning games. Its key points concern the issues of thinking learning games as fun, educative and realistic, which is how learning games...... are commonly conceived as means for staging learning processes, and that thinking learning games so has an inhibiting effect in regard to creating learning processes. The paper draws upon a qualitative study of participants' experiences with ‘the EIS Simulation', which is a computer-based learning game...

  1. Generating realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2011-01-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs, and show a connection with the straight skeleton of P. We show that the maximum possible number of distinct realistic roofs over P is ( ⌊(n-4)/4⌋ (n-4)/2) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n 4) preprocessing time. We also present an O(n 5)-time algorithm for computing a realistic roof with minimum height or volume. © 2011 Springer-Verlag.

  2. Sotsialistlik realist Keskküla

    Index Scriptorium Estoniae

    1998-01-01

    Londonis 1998. a. ilmunud inglise kunstikriitiku Matthew Cullerne Bowni monograafias "Socialist Realist Painting" on eesti kunstnikest Enn Põldroos, Nikolai Kormashov, Ando Keskküla, Kormashovi ja Keskküla maalide reproduktsioonid

  3. Estimating the relative weights of visual and auditory tau versus heuristic-based cues for time-to-contact judgments in realistic, familiar scenes by older and younger adults.

    Science.gov (United States)

    Keshavarz, Behrang; Campos, Jennifer L; DeLucia, Patricia R; Oberfeld, Daniel

    2017-04-01

    Estimating time to contact (TTC) involves multiple sensory systems, including vision and audition. Previous findings suggested that the ratio of an object's instantaneous optical size/sound intensity to its instantaneous rate of change in optical size/sound intensity (τ) drives TTC judgments. Other evidence has shown that heuristic-based cues are used, including final optical size or final sound pressure level. Most previous studies have used decontextualized and unfamiliar stimuli (e.g., geometric shapes on a blank background). Here we evaluated TTC estimates by using a traffic scene with an approaching vehicle to evaluate the weights of visual and auditory TTC cues under more realistic conditions. Younger (18-39 years) and older (65+ years) participants made TTC estimates in three sensory conditions: visual-only, auditory-only, and audio-visual. Stimuli were presented within an immersive virtual-reality environment, and cue weights were calculated for both visual cues (e.g., visual τ, final optical size) and auditory cues (e.g., auditory τ, final sound pressure level). The results demonstrated the use of visual τ as well as heuristic cues in the visual-only condition. TTC estimates in the auditory-only condition, however, were primarily based on an auditory heuristic cue (final sound pressure level), rather than on auditory τ. In the audio-visual condition, the visual cues dominated overall, with the highest weight being assigned to visual τ by younger adults, and a more equal weighting of visual τ and heuristic cues in older adults. Overall, better characterizing the effects of combined sensory inputs, stimulus characteristics, and age on the cues used to estimate TTC will provide important insights into how these factors may affect everyday behavior.

  4. Realistic Scheduling Mechanism for Smart Homes

    Directory of Open Access Journals (Sweden)

    Danish Mahmood

    2016-03-01

    Full Text Available In this work, we propose a Realistic Scheduling Mechanism (RSM to reduce user frustration and enhance appliance utility by classifying appliances with respective constraints and their time of use effectively. Algorithms are proposed regarding functioning of home appliances. A 24 hour time slot is divided into four logical sub-time slots, each composed of 360 min or 6 h. In these sub-time slots, only desired appliances (with respect to appliance classification are scheduled to raise appliance utility, restricting power consumption by a dynamically modelled power usage limiter that does not only take the electricity consumer into account but also the electricity supplier. Once appliance, time and power usage limiter modelling is done, we use a nature-inspired heuristic algorithm, Binary Particle Swarm Optimization (BPSO, optimally to form schedules with given constraints representing each sub-time slot. These schedules tend to achieve an equilibrium amongst appliance utility and cost effectiveness. For validation of the proposed RSM, we provide a comparative analysis amongst unscheduled electrical load usage, scheduled directly by BPSO and RSM, reflecting user comfort, which is based upon cost effectiveness and appliance utility.

  5. Towards a realistic description of hadron resonances

    Science.gov (United States)

    Schmidt, R. A.; Canton, L.; Schweiger, W.; Plessas, W.

    2016-08-01

    We report on our attempts of treating excited hadron states as true quantum resonances. Hitherto the spectroscopy of mesons, usually considered as quark-antiquark systems, and of baryons, usually considered as three-quark systems, has been treated through excitation spectra of bound states (namely, confined few-quark systems), corresponding to poles of the quantum-mechanical resolvent at real negative values in the complex energy plane. As a result the wave functions, i.e. the residua of the resolvent, have not exhibited the behaviour as required for hadron resonances with their multiple decay modes. This has led to disturbing shortcomings in the description of hadronic resonance phenomena. We have aimed at a more realistic description of hadron resonances within relativistic constituent-quark models taking into account explicitly meson-decay channels. The corresponding coupled-channels theory is based on a relativistically invariant mass operator capable of producing hadron ground states with real energies and hadron resonances with complex energies, the latter corresponding to poles in the lower half-plane of the unphysical sheet of the complex energy plane. So far we have demonstrated the feasibility of the coupled-channels approach to hadron resonances along model calculations producing indeed the desired properties. The corresponding spectral properties will be discussed in this contribution. More refined studies are under way towards constructing a coupled-channels relativistic constituent-quark model for meson and baryon resonances.

  6. Realistic costs of carbon capture

    Energy Technology Data Exchange (ETDEWEB)

    Al Juaied, Mohammed (Harvard Univ., Cambridge, MA (US). Belfer Center for Science and International Affiaris); Whitmore, Adam (Hydrogen Energy International Ltd., Weybridge (GB))

    2009-07-01

    There is a growing interest in carbon capture and storage (CCS) as a means of reducing carbon dioxide (CO2) emissions. However there are substantial uncertainties about the costs of CCS. Costs for pre-combustion capture with compression (i.e. excluding costs of transport and storage and any revenue from EOR associated with storage) are examined in this discussion paper for First-of-a-Kind (FOAK) plant and for more mature technologies, or Nth-of-a-Kind plant (NOAK). For FOAK plant using solid fuels the levelised cost of electricity on a 2008 basis is approximately 10 cents/kWh higher with capture than for conventional plants (with a range of 8-12 cents/kWh). Costs of abatement are found typically to be approximately US$150/tCO2 avoided (with a range of US$120-180/tCO2 avoided). For NOAK plants the additional cost of electricity with capture is approximately 2-5 cents/kWh, with costs of the range of US$35-70/tCO2 avoided. Costs of abatement with carbon capture for other fuels and technologies are also estimated for NOAK plants. The costs of abatement are calculated with reference to conventional SCPC plant for both emissions and costs of electricity. Estimates for both FOAK and NOAK are mainly based on cost data from 2008, which was at the end of a period of sustained escalation in the costs of power generation plant and other large capital projects. There are now indications of costs falling from these levels. This may reduce the costs of abatement and costs presented here may be 'peak of the market' estimates. If general cost levels return, for example, to those prevailing in 2005 to 2006 (by which time significant cost escalation had already occurred from previous levels), then costs of capture and compression for FOAK plants are expected to be US$110/tCO2 avoided (with a range of US$90-135/tCO2 avoided). For NOAK plants costs are expected to be US$25-50/tCO2. Based on these considerations a likely representative range of costs of abatement from CCS

  7. Realistic roofs over a rectilinear polygon

    KAUST Repository

    Ahn, Heekap

    2013-11-01

    Given a simple rectilinear polygon P in the xy-plane, a roof over P is a terrain over P whose faces are supported by planes through edges of P that make a dihedral angle π/4 with the xy-plane. According to this definition, some roofs may have faces isolated from the boundary of P or even local minima, which are undesirable for several practical reasons. In this paper, we introduce realistic roofs by imposing a few additional constraints. We investigate the geometric and combinatorial properties of realistic roofs and show that the straight skeleton induces a realistic roof with maximum height and volume. We also show that the maximum possible number of distinct realistic roofs over P is ((n-4)(n-4)/4 /2⌋) when P has n vertices. We present an algorithm that enumerates a combinatorial representation of each such roof in O(1) time per roof without repetition, after O(n4) preprocessing time. We also present an O(n5)-time algorithm for computing a realistic roof with minimum height or volume. © 2013 Elsevier B.V.

  8. Configuration of Dual Connectivity with Flow Control in a Realistic Urban Scenario

    DEFF Research Database (Denmark)

    Wang, Hua; Gerardino, Guillermo Andrés Pocovi; Rosa, Claudio;

    2015-01-01

    the performance of DC in a realistic deployment based on three-dimensional data from a dense urban European capital area, assuming realistic flow control on the backhaul connections between the macro and small cell eNBs. It is found that the configuration of UEs with DC plays a critical role in the performance...

  9. Role of dissipation in realistic Majorana nanowires

    Science.gov (United States)

    Liu, Chun-Xiao; Sau, Jay D.; Das Sarma, S.

    2017-02-01

    We carry out a realistic simulation of Majorana nanowires in order to understand the latest high-quality experimental data [H. Zhang et al., arXiv:1603.04069 (2016)] and, in the process, develop a comprehensive picture for what physical mechanisms may be operational in realistic nanowires leading to discrepancies between minimal theory and experimental observations (e.g., weakness and broadening of the zero-bias peak and breaking of particle-hole symmetry). Our focus is on understanding specific intriguing features in the data, and our goal is to establish matters of principle controlling the physics of the best possible nanowires available in current experiments. We identify dissipation, finite temperature, multi-sub-band effects, and the finite tunnel barrier as the four most important physical mechanisms controlling the zero-bias conductance peak. Our theoretical results including these realistic effects agree well with the best available experimental data in ballistic nanowires.

  10. Righteous realists: Perceptions of American power and responsibility in the nuclear age

    Energy Technology Data Exchange (ETDEWEB)

    Rosenthal, J.H.

    1988-01-01

    This is a study of the moral and ethical dimensions of political realism in post-World War II America, especially in relation to realist thought on nuclear weapons issues. Emphasis is placed on evolving notions of power and responsibility as they form the basis for a realist philosophy of power in the nuclear age. It is argued that the realists developed a concept of responsible power which was a hybrid of traditional American ideals and European Realpolitik. Included are chapters on the personal and intellectual background of five noteworthy realists, the realist position on some basic dilemmas in political ethics, the problem of usable and unusable force, the realists' view on deterrence and arms control, the question of democracy versus guardianship, and the realists as cultural critics. This study highlights the coherence of realist thought while pointing out the paradoxes upon which it is based. It situates realism in its historical context and reveals realism's relationship to explicit political and cultural values. It concludes that at their core, the realists were moralists; and realism was the entity through which they reconciled morality and power.

  11. Realist synthesis: illustrating the method for implementation research

    Directory of Open Access Journals (Sweden)

    Rycroft-Malone Jo

    2012-04-01

    Full Text Available Abstract Background Realist synthesis is an increasingly popular approach to the review and synthesis of evidence, which focuses on understanding the mechanisms by which an intervention works (or not. There are few published examples of realist synthesis. This paper therefore fills a gap by describing, in detail, the process used for a realist review and synthesis to answer the question ‘what interventions and strategies are effective in enabling evidence-informed healthcare?’ The strengths and challenges of conducting realist review are also considered. Methods The realist approach involves identifying underlying causal mechanisms and exploring how they work under what conditions. The stages of this review included: defining the scope of the review (concept mining and framework formulation; searching for and scrutinising the evidence; extracting and synthesising the evidence; and developing the narrative, including hypotheses. Results Based on key terms and concepts related to various interventions to promote evidence-informed healthcare, we developed an outcome-focused theoretical framework. Questions were tailored for each of four theory/intervention areas within the theoretical framework and were used to guide development of a review and data extraction process. The search for literature within our first theory area, change agency, was executed and the screening procedure resulted in inclusion of 52 papers. Using the questions relevant to this theory area, data were extracted by one reviewer and validated by a second reviewer. Synthesis involved organisation of extracted data into evidence tables, theming and formulation of chains of inference, linking between the chains of inference, and hypothesis formulation. The narrative was developed around the hypotheses generated within the change agency theory area. Conclusions Realist synthesis lends itself to the review of complex interventions because it accounts for context as well as

  12. Neo-realistic Features in Snow Child

    Institute of Scientific and Technical Information of China (English)

    夏静林

    2013-01-01

    This essay illustrates neo-realistic features in Snow Child. This short story inherits and develops“the typical character in the typical environment”and the traditional linear time order in realistic works. At the same time, it has some changes and transcendent. It uses real brands, events and goods in reality to create a-true to-life picture of the contemporary world. It ex⁃plores deeper in character’s psychology and creates a circular narration with three flashbacks.

  13. Keeping It Real: How Realistic Does Realistic Fiction for Children Need to Be?

    Science.gov (United States)

    O'Connor, Barbara

    2010-01-01

    O'Connor, an author of realistic fiction for children, shares her attempts to strike a balance between carefree, uncensored, authentic, realistic writing and age-appropriate writing. Of course, complicating that balancing act is the fact that what seems age-appropriate to her might not seem so to everyone. O'Connor suggests that while it may be…

  14. Realistic Detectability of Close Interstellar Comets

    Science.gov (United States)

    Cook, Nathaniel V.; Ragozzine, Darin; Granvik, Mikael; Stephens, Denise C.

    2016-07-01

    During the planet formation process, billions of comets are created and ejected into interstellar space. The detection and characterization of such interstellar comets (ICs) (also known as extra-solar planetesimals or extra-solar comets) would give us in situ information about the efficiency and properties of planet formation throughout the galaxy. However, no ICs have ever been detected, despite the fact that their hyperbolic orbits would make them readily identifiable as unrelated to the solar system. Moro-Martín et al. have made a detailed and reasonable estimate of the properties of the IC population. We extend their estimates of detectability with a numerical model that allows us to consider “close” ICs, e.g., those that come within the orbit of Jupiter. We include several constraints on a “detectable” object that allow for realistic estimates of the frequency of detections expected from the Large Synoptic Survey Telescope (LSST) and other surveys. The influence of several of the assumed model parameters on the frequency of detections is explored in detail. Based on the expectation from Moro-Martín et al., we expect that LSST will detect 0.001-10 ICs during its nominal 10 year lifetime, with most of the uncertainty from the unknown number density of small (nuclei of ˜0.1-1 km) ICs. Both asteroid and comet cases are considered, where the latter includes various empirical prescriptions of brightening. Using simulated LSST-like astrometric data, we study the problem of orbit determination for these bodies, finding that LSST could identify their orbits as hyperbolic and determine an ephemeris sufficiently accurate for follow-up in about 4-7 days. We give the hyperbolic orbital parameters of the most detectable ICs. Taking the results into consideration, we give recommendations to future searches for ICs.

  15. Culture from the Perspective of Realistic Philosophy

    Directory of Open Access Journals (Sweden)

    Wojciech Daszkiewicz

    2015-12-01

    Full Text Available The article underlines the moments that define the metaphysical understanding of culture. According to this conception, culture in its most basic meaning is rationalization (intellectualization of nature. The article is focused on the following areas: genetic-exemplarist analysis of cultural works and definition of culture from the perspective of realistic philosophy.

  16. A Look at Young Children's Realistic Fiction.

    Science.gov (United States)

    Madsen, Jane M.; Wickersham, Elaine B.

    1980-01-01

    Analyzes recent realistic fiction for children produced in the United States in terms of ethnicity, stereotyped behavior, and themes. Concludes that the sample did not reflect equivalent treatment of males and females nor the culturally pluralistic makeup of U.S. society. Provides an annotated bibliography of the books analyzed. (Author/FL)

  17. The romantic paradigm of realist Dostoyevsky

    OpenAIRE

    LIPICH V.V.; LIPICH T.I.

    2015-01-01

    The article is devoted to the inheritance of the traditions of romanticism in the creative activity of young F. M. Dostoyevsky. The article dwells upon the certain points of integration and the typological interrelation of the artistic views of F. M. Dostoyevsky a writer-realist with the esthetic system and poetics of romanticism.

  18. An iterative approach for generating statistically realistic populations of households

    CERN Document Server

    Gargiulo, Floriana; Huet, Sylvie; Deffuant, Guillaume

    2009-01-01

    Background: Many different simulation frameworks, in different topics, need to treat realistic datasets to initialize and calibrate the system. A precise reproduction of initial states is extremely important to obtain reliable forecast from the model. Methodology/Principal Findings: This paper proposes an algorithm to create an artificial population where individuals are described by their age, and are gathered in households respecting a variety of statistical constraints (distribution of household types, sizes, age of household head, difference of age between partners and among parents and children). Such a population is often the initial state of microsimulation or (agent) individual-based models. To get a realistic distribution of households is often very important, because this distribution has an impact on the demographic evolution. Usual techniques from microsimulation approach cross different sources of aggregated data for generating individuals. In our case the number of combinations of different hous...

  19. Exposure render: an interactive photo-realistic volume rendering framework.

    Directory of Open Access Journals (Sweden)

    Thomas Kroes

    Full Text Available The field of volume visualization has undergone rapid development during the past years, both due to advances in suitable computing hardware and due to the increasing availability of large volume datasets. Recent work has focused on increasing the visual realism in Direct Volume Rendering (DVR by integrating a number of visually plausible but often effect-specific rendering techniques, for instance modeling of light occlusion and depth of field. Besides yielding more attractive renderings, especially the more realistic lighting has a positive effect on perceptual tasks. Although these new rendering techniques yield impressive results, they exhibit limitations in terms of their exibility and their performance. Monte Carlo ray tracing (MCRT, coupled with physically based light transport, is the de-facto standard for synthesizing highly realistic images in the graphics domain, although usually not from volumetric data. Due to the stochastic sampling of MCRT algorithms, numerous effects can be achieved in a relatively straight-forward fashion. For this reason, we have developed a practical framework that applies MCRT techniques also to direct volume rendering (DVR. With this work, we demonstrate that a host of realistic effects, including physically based lighting, can be simulated in a generic and flexible fashion, leading to interactive DVR with improved realism. In the hope that this improved approach to DVR will see more use in practice, we have made available our framework under a permissive open source license.

  20. Centralized Cooperative Positioning and Tracking with Realistic Communications Constraints

    DEFF Research Database (Denmark)

    Mensing, Christian; Nielsen, Jimmy Jessen

    2010-01-01

    In this paper, we investigate the performance of centralized cooperative positioning algorithms. Compared to traditional positioning algorithms which solely exploit ranging information from anchor nodes, cooperative positioning additionally uses measurements from peer-to-peer links between...... on the overall performance will be assessed. As we are considering a dynamic scenario, the cooperative positioning algorithms are based on extended Kalman filtering for position estimation and tracking. Simulation results for ultra-wideband based ranging information and WLAN based communications infrastructure...... show the benefits of cooperative position and tracking for realistic measurement and mobility models....

  1. Presupernova neutrinos: realistic emissivities from stellar evolution

    CERN Document Server

    Patton, Kelly M

    2015-01-01

    We present a new calculation of neutrino emissivities and energy spectra from a presupernova, a massive star going through the advanced stages of nuclear burning in the months before becoming a supernova. The contributions from beta decay and electron capture, pair annihilation, plasmon decay, and the photoneutrino process are modeled in detail, using updated tabulated nuclear rates. We also use realistic conditions of temperature, density, electron fraction and nuclear isotopic composition of the star from the state of the art stellar evolution code MESA. It is found that beta processes contribute substantially to the neutrino flux above realistic detection thresholds of few MeV, at selected positions and times in the evolution of the star.

  2. Spectral tunability of realistic plasmonic nanoantennas

    Energy Technology Data Exchange (ETDEWEB)

    Portela, Alejandro; Matsui, Hiroaki; Tabata, Hitoshi, E-mail: tabata@bioeng.t.u-tokyo.ac.jp [Department of Bioengineering, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo 113-8656 (Japan); Yano, Takaaki; Hayashi, Tomohiro; Hara, Masahiko [Department of Electronic Chemistry, Tokyo Institute of Technology, Midori-ku, Yokohama, Kanagawa 226-8502 (Japan); Santschi, Christian; Martin, Olivier J. F. [Nanophotonics and Metrology Laboratory, Swiss Federal Institute of Technology Lausanne, Lausanne CH-1015 (Switzerland)

    2014-09-01

    Single nanoantenna spectroscopy was carried out on realistic dipole nanoantennas with various arm lengths and gap sizes fabricated by electron-beam lithography. A significant difference in resonance wavelength between realistic and ideal nanoantennas was found by comparing their spectral response. Consequently, the spectral tunability (96 nm) of the structures was significantly lower than that of simulated ideal nanoantennas. These observations, attributed to the nanofabrication process, are related to imperfections in the geometry, added metal adhesion layer, and shape modifications, which are analyzed in this work. Our results provide important information for the design of dipole nanoantennas clarifying the role of the structural modifications on the resonance spectra, as supported by calculations.

  3. Realistic molecular model of kerogen's nanostructure

    Science.gov (United States)

    Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E.; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J.-M.; Coasne, Benoit

    2016-05-01

    Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp2/sp3 hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms.

  4. Realistic molecular model of kerogen's nanostructure.

    Science.gov (United States)

    Bousige, Colin; Ghimbeu, Camélia Matei; Vix-Guterl, Cathie; Pomerantz, Andrew E; Suleimenova, Assiya; Vaughan, Gavin; Garbarino, Gaston; Feygenson, Mikhail; Wildgruber, Christoph; Ulm, Franz-Josef; Pellenq, Roland J-M; Coasne, Benoit

    2016-05-01

    Despite kerogen's importance as the organic backbone for hydrocarbon production from source rocks such as gas shale, the interplay between kerogen's chemistry, morphology and mechanics remains unexplored. As the environmental impact of shale gas rises, identifying functional relations between its geochemical, transport, elastic and fracture properties from realistic molecular models of kerogens becomes all the more important. Here, by using a hybrid experimental-simulation method, we propose a panel of realistic molecular models of mature and immature kerogens that provide a detailed picture of kerogen's nanostructure without considering the presence of clays and other minerals in shales. We probe the models' strengths and limitations, and show that they predict essential features amenable to experimental validation, including pore distribution, vibrational density of states and stiffness. We also show that kerogen's maturation, which manifests itself as an increase in the sp(2)/sp(3) hybridization ratio, entails a crossover from plastic-to-brittle rupture mechanisms.

  5. Realistic Approach for Phasor Measurement Unit Placement

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2015-01-01

    This paper presents a realistic cost-effectivemodel for optimal placement of phasor measurement units (PMUs) for complete observability of a power system considering practical cost implications. The proposed model considers hidden or otherwise unaccounted practical costs involved in PMU...... installation. Consideration of these hidden but significant and integral part of total PMU installation costs was inspired from practical experience on a real-life project. The proposedmodel focuses on the minimization of total realistic costs instead of a widely used theoretical concept of a minimal number...... of PMUs. The proposed model has been applied to IEEE 14-bus, IEEE 24-bus, IEEE 30-bus, New England 39-bus, and large power system of 300 buses and real life Danish grid. A comparison of the presented results with those reported by traditionalmethods has also been shown to justify the effectiveness...

  6. Algorithm for Realistic Modeling of Graphitic Systems

    Directory of Open Access Journals (Sweden)

    A.V. Khomenko

    2011-01-01

    Full Text Available An algorithm for molecular dynamics simulations of graphitic systems using realistic semiempirical interaction potentials of carbon atoms taking into account both short-range and long-range contributions is proposed. Results of the use of the algorithm for a graphite sample are presented. The scalability of the algorithm depending on the system size and the number of processor cores involved in the calculations is analyzed.

  7. Relating realist metatheory to issues of gender and mental health.

    Science.gov (United States)

    Bergin, M; Wells, John S G; Owen, Sara

    2010-06-01

    This paper seeks to advance the debate that considers critical realism as an alternative approach for understanding gender and mental health and its relatedness to mental health research and practice. The knowledge base of how 'sex' and 'gender' affect mental health and illness is expanding. However, the way we conceptualize gender is significant and challenging as quite often our ability to think about 'gender' as independent of 'sex' is not common. The influences and interplay of how sex (biological) and gender (social) affect mental health and illness requires consideration. Critical realism suggests a shared ontology and epistemology for the natural and social sciences. While much of the debate surrounding gender is guided within a constructivist discourse, an exploration of the concept 'gender' is reflected on and some key realist propositions are considered for mental health research and practice. This is achieved through the works of some key realist theorists. Critical realism offers potential for research and practice in relation to gender and mental health because it facilitates changes in our understanding, while simultaneously, not discarding that which is already known. In so doing, it allows the biological (sex) and social (gender) domains of knowledge for mental health and illness to coexist, without either being reduced to or defined by the other. Arguably, greater depth and explanations for gender and mental health issues are presented within a realist metatheory.

  8. Blend Shape Interpolation and FACS for Realistic Avatar

    Science.gov (United States)

    Alkawaz, Mohammed Hazim; Mohamad, Dzulkifli; Basori, Ahmad Hoirul; Saba, Tanzila

    2015-03-01

    The quest of developing realistic facial animation is ever-growing. The emergence of sophisticated algorithms, new graphical user interfaces, laser scans and advanced 3D tools imparted further impetus towards the rapid advancement of complex virtual human facial model. Face-to-face communication being the most natural way of human interaction, the facial animation systems became more attractive in the information technology era for sundry applications. The production of computer-animated movies using synthetic actors are still challenging issues. Proposed facial expression carries the signature of happiness, sadness, angry or cheerful, etc. The mood of a particular person in the midst of a large group can immediately be identified via very subtle changes in facial expressions. Facial expressions being very complex as well as important nonverbal communication channel are tricky to synthesize realistically using computer graphics. Computer synthesis of practical facial expressions must deal with the geometric representation of the human face and the control of the facial animation. We developed a new approach by integrating blend shape interpolation (BSI) and facial action coding system (FACS) to create a realistic and expressive computer facial animation design. The BSI is used to generate the natural face while the FACS is employed to reflect the exact facial muscle movements for four basic natural emotional expressions such as angry, happy, sad and fear with high fidelity. The results in perceiving the realistic facial expression for virtual human emotions based on facial skin color and texture may contribute towards the development of virtual reality and game environment of computer aided graphics animation systems.

  9. Simulation of human ischemic stroke in realistic 3D geometry

    Science.gov (United States)

    Dumont, Thierry; Duarte, Max; Descombes, Stéphane; Dronne, Marie-Aimée; Massot, Marc; Louvet, Violaine

    2013-06-01

    In silico research in medicine is thought to reduce the need for expensive clinical trials under the condition of reliable mathematical models and accurate and efficient numerical methods. In the present work, we tackle the numerical simulation of reaction-diffusion equations modeling human ischemic stroke. This problem induces peculiar difficulties like potentially large stiffness which stems from the broad spectrum of temporal scales in the nonlinear chemical source term as well as from the presence of steep spatial gradients in the reaction fronts, spatially very localized. Furthermore, simulations on realistic 3D geometries are mandatory in order to describe correctly this type of phenomenon. The main goal of this article is to obtain, for the first time, 3D simulations on realistic geometries and to show that the simulation results are consistent with those obtain in experimental studies or observed on MRI images in stroke patients. For this purpose, we introduce a new resolution strategy based mainly on time operator splitting that takes into account complex geometry coupled with a well-conceived parallelization strategy for shared memory architectures. We consider then a high order implicit time integration for the reaction and an explicit one for the diffusion term in order to build a time operator splitting scheme that exploits efficiently the special features of each problem. Thus, we aim at solving complete and realistic models including all time and space scales with conventional computing resources, that is on a reasonably powerful workstation. Consequently and as expected, 2D and also fully 3D numerical simulations of ischemic strokes for a realistic brain geometry, are conducted for the first time and shown to reproduce the dynamics observed on MRI images in stroke patients. Beyond this major step, in order to improve accuracy and computational efficiency of the simulations, we indicate how the present numerical strategy can be coupled with spatial

  10. Quantum coding theory with realistic physical constraints

    CERN Document Server

    Yoshida, Beni

    2010-01-01

    The following open problems, which concern a fundamental limit on coding properties of quantum codes with realistic physical constraints, are analyzed and partially answered here: (a) the upper bound on code distances of quantum error-correcting codes with geometrically local generators, (b) the feasibility of a self-correcting quantum memory. To investigate these problems, we study stabilizer codes supported by local interaction terms with translation and scale symmetries on a $D$-dimensional lattice. Our analysis uses the notion of topology emerging in geometric shapes of logical operators, which sheds a surprising new light on theory of quantum codes with physical constraints.

  11. Realistic searches on stretched exponential networks

    Indian Academy of Sciences (India)

    Parogama Sen

    2008-08-01

    We consider navigation or search schemes on networks which have a degree distribution of the form () ∝ exp(−). In addition, the linking probability is taken to be dependent on social distances and is governed by a parameter . The searches are realistic in the sense that not all search chains can be completed. An estimate of = ρ/d, where is the success rate and d the dynamic path length, shows that for a network of nodes, ∝ - in general. Dynamic small world effect, i.e., ≃ 0 is shown to exist in a restricted region of the - plane.

  12. An Introduction to a Realistic Quantum Physics

    CERN Document Server

    Preparata, Giuliano

    2003-01-01

    This book is a remarkable synthesis, a clear and simple introduction to Quantum Physics with a sort of Galilean dialogue on the supreme systems of contemporary Physics. The author, whose research interests and work extended from quarks to liquid systems and from crystals to stars, introduces the common conceptual and mathematical framework of all quantum theories, realistic enough to successfully confront Nature: Quantum Field Theory applied to the study of both dilute and condensed matter. In the dilute limit, quantum mechanics is shown to be a good approximation to Quantum Field Theory. Howe

  13. Ultra-Reliable Communications in Failure-Prone Realistic Networks

    DEFF Research Database (Denmark)

    Gerardino, Guillermo Andrés Pocovi; Lauridsen, Mads; Alvarez, Beatriz Soret

    2016-01-01

    . Micro and macroscopic diversity techniques are proved to be important enablers of ultra-reliable communications. Particularly, it is shown how a 4x4 MIMO scheme with three orders of macroscopic diversity can achieve the required SINR outage performance. Smaller gains are obtained from interference......We investigate the potential of different diversity and interference management techniques to achieve the required downlink SINR outage probability for ultra-reliable communications. The evaluation is performed in a realistic network deployment based on site-specific data from a European capital...

  14. Realistic Radio Communications in Pilot Simulator Training

    Science.gov (United States)

    Burki-Cohen, Judith; Kendra, Andrew J.; Kanki, Barbara G.; Lee, Alfred T.

    2000-01-01

    Simulators used for total training and evaluation of airline pilots must satisfy stringent criteria in order to assure their adequacy for training and checking maneuvers. Air traffic control and company radio communications simulation, however, may still be left to role-play by the already taxed instructor/evaluators in spite of their central importance in every aspect of the flight environment. The underlying premise of this research is that providing a realistic radio communications environment would increase safety by enhancing pilot training and evaluation. This report summarizes the first-year efforts of assessing the requirement and feasibility of simulating radio communications automatically. A review of the training and crew resource/task management literature showed both practical and theoretical support for the need for realistic radio communications simulation. A survey of 29 instructor/evaluators from 14 airlines revealed that radio communications are mainly role-played by the instructor/evaluators. This increases instructor/evaluators' own workload while unrealistically lowering pilot communications load compared to actual operations, with a concomitant loss in training/evaluation effectiveness. A technology review searching for an automated means of providing radio communications to and from aircraft with minimal human effort showed that while promising, the technology is still immature. Further research and the need for establishing a proof-of-concept are also discussed.

  15. Generation of anatomically realistic numerical phantoms for optoacoustic breast imaging

    Science.gov (United States)

    Lou, Yang; Mitsuhashi, Kenji; Appleton, Catherine M.; Oraevsky, Alexander; Anastasio, Mark A.

    2016-03-01

    Because optoacoustic tomography (OAT) can provide functional information based on hemoglobin contrast, it is a promising imaging modality for breast cancer diagnosis. Developing an effective OAT breast imaging system requires balancing multiple design constraints, which can be expensive and time-consuming. Therefore, computer- simulation studies are often conducted to facilitate this task. However, most existing computer-simulation studies of OAT breast imaging employ simple phantoms such as spheres or cylinders that over-simplify the complex anatomical structures in breasts, thus limiting the value of these studies in guiding real-world system design. In this work, we propose a method to generate realistic numerical breast phantoms for OAT research based on clinical magnetic resonance imaging (MRI) data. The phantoms include a skin layer that defines breast-air boundary, major vessel branches that affect light absorption in the breast, and fatty tissue and fibroglandular tissue whose acoustical heterogeneity perturbs acoustic wave propagation. By assigning realistic optical and acoustic parameters to different tissue types, we establish both optic and acoustic breast phantoms, which will be exported into standard data formats for cross-platform usage.

  16. CHARMM-GUI Membrane Builder toward realistic biological membrane simulations.

    Science.gov (United States)

    Wu, Emilia L; Cheng, Xi; Jo, Sunhwan; Rui, Huan; Song, Kevin C; Dávila-Contreras, Eder M; Qi, Yifei; Lee, Jumin; Monje-Galvan, Viviana; Venable, Richard M; Klauda, Jeffery B; Im, Wonpil

    2014-10-15

    CHARMM-GUI Membrane Builder, http://www.charmm-gui.org/input/membrane, is a web-based user interface designed to interactively build all-atom protein/membrane or membrane-only systems for molecular dynamics simulations through an automated optimized process. In this work, we describe the new features and major improvements in Membrane Builder that allow users to robustly build realistic biological membrane systems, including (1) addition of new lipid types, such as phosphoinositides, cardiolipin (CL), sphingolipids, bacterial lipids, and ergosterol, yielding more than 180 lipid types, (2) enhanced building procedure for lipid packing around protein, (3) reliable algorithm to detect lipid tail penetration to ring structures and protein surface, (4) distance-based algorithm for faster initial ion displacement, (5) CHARMM inputs for P21 image transformation, and (6) NAMD equilibration and production inputs. The robustness of these new features is illustrated by building and simulating a membrane model of the polar and septal regions of E. coli membrane, which contains five lipid types: CL lipids with two types of acyl chains and phosphatidylethanolamine lipids with three types of acyl chains. It is our hope that CHARMM-GUI Membrane Builder becomes a useful tool for simulation studies to better understand the structure and dynamics of proteins and lipids in realistic biological membrane environments.

  17. Realistic model for radiation-matter interaction

    CERN Document Server

    Pakula, R A

    2004-01-01

    This paper presents a realistic model that describes radiation-matter interactions. This is achieved by a generalization of first quantization, where the Maxwell equations are interpreted as the electromagnetic component of the Schrodinger equation. This picture is complemented by the consideration of electrons and photons as real particles in three-dimensional space, following guiding conditions derived from the particle-wave-functions to which they are associated. The guiding condition for the electron is taken from Bohmian mechanics, while the photon velocity is defined as the ratio between the Poynting vector and the electromagnetic energy density. The case of many particles is considered, taking into account their statistical properties. The formalism is applied to a two level system, providing an intuitive description for spontaneous emission, Lamb shift, scattering, absorption, dispersion, resonance fluorescence and vacuum fields. This model describes quantum jumps by the entanglement between the photo...

  18. Presupernova neutrinos: realistic emissivities from stellar evolution

    Science.gov (United States)

    Patton, Kelly; Lunardini, Cecilia; Farmer, Rob; Timmes, Frank

    2017-01-01

    We present a calculation of neutrino emissivities and energy spectra from a presupernova, a massive star going through the advanced stages of nuclear burning before becoming a supernova. Neutrinos produced from beta decay and electron capture, as well as pair annihilation, plasmon decay, and the photoneutrino process are included. We use the state of the art stellar evolution code MESA to obtain realistic conditions for temperature, density, electron fraction, and nuclear isotopic composition. We have found that beta processes contribute significantly to the neutrino flux at potentially detectable energies of a few MeV. Estimates for the number of events at several current and future detectors are presented for the last few hours before collapse.

  19. E. H. Carr: En kompleks realist

    DEFF Research Database (Denmark)

    Meyn, Carina Ann

    2008-01-01

    Edward Hallett Carr er blevet kaldt alt fra realist til utopist til slet og ret ,,farlig". Denne artikel giver en bedre forstaelse af, hvorfor et centralt pejlemærke i disci­plinen international politik bliver beskrevet på så mange - tilsyneladende - modsætningsfyldte måder. I stedet for at tage...... udgangspunkt i en realistisk eller en utopisk læsning af Carrs værker bidrager denne artikel med en tredje læsning af Carrs teori, der samtænker ,,den realistiske Carr" og ,,den utopiske Carr". Det overordnede argument i artiklen er, at for at kunne finde mening og sammen­hæng i Carrs politiske teori, ma man...... nødvendigvis samtænke Carrs realisme og utopisme med hans underliggende radikalisme....

  20. Performance Evaluation of MANET in Realistic Environment

    Directory of Open Access Journals (Sweden)

    Shailender Gupta

    2012-07-01

    Full Text Available In order to facilitate communication in Mobile Ad hoc Network (MANET, routing protocols are developed. The performance of these protocols depends upon various factors such as: transmission range, number of nodes deployed and mobility of the nodes. Another factor which affects the performance of MANET routing protocols is the environment in which ad hoc network is deployed. The MANET environment may contain obstacles such as mountains lakes, buildings and river. These obstacles restrict nodes movement but may or may not obstruct the effective transmission range of nodes deployed. This paper is an effort to evaluate the performance of MANET routing protocols in presence of obstacles by designing a simulator in MATLAB-10. To make the situation more realistic obstacle of different shapes, size, number and type were introduced in the simulation region. We found significant impact of the same on the performance of routing protocols

  1. The Radiative Tail of Realistic Gravitational Collapse

    CERN Document Server

    Hod, S

    2000-01-01

    An astrophysically realistic model of wave dynamics in black-hole spacetimes must involve a {\\it non}-spherical background geometry with {\\it angular momentum}. We consider the evolution of {\\it gravitational} (and electromagnetic) perturbations in {\\it rotating} Kerr spacetimes. We show that a rotating Kerr black hole becomes ``bald'' {\\it slower} than the corresponding spherically-symmetric Schwarzschild black hole. Moreover, our results {\\it turn over} the traditional belief (which has been widely accepted during the last three decades) that the late-time tail of gravitational collapse is universal. In particular, we show that different fields have {\\it different} decaying rates. Our results are also of importance both to the study of the no-hair conjecture and the mass-inflation scenario (stability of Cauchy horizons).

  2. Realistic Multimedia Simulations for Informatics Students

    Directory of Open Access Journals (Sweden)

    Ioannis Pachoulaki

    2012-08-01

    Full Text Available Realistic multimedia simulations are effective in helping students overcome their fear of physics and gain fundamental knowledge of physical processes. An elective course has been designed in the Applied Informatics and Multimedia Department at TEI of Crete to help informatics students overcome their physics shyness by hands-on experience on scientific multimedia simulations. The approach is justified in terms of the rich employment opportunities in the game and multimedia industries where a sound basis in physics, mathematics and numerical analysis is a necessity. Student feedback shows that they embrace the adopted approach, which uses open source tools to minimize programming so as to allow both instructor and students to focus on the science and complete a greater number of simulations.

  3. Realistic page-turning of electronic books

    Science.gov (United States)

    Fan, Chaoran; Li, Haisheng; Bai, Yannan

    2014-01-01

    The booming electronic books (e-books), as an extension to the paper book, are popular with readers. Recently, many efforts are put into the realistic page-turning simulation o f e-book to improve its reading experience. This paper presents a new 3D page-turning simulation approach, which employs piecewise time-dependent cylindrical surfaces to describe the turning page and constructs smooth transition method between time-dependent cylinders. The page-turning animation is produced by sequentially mapping the turning page into the cylinders with different radii and positions. Compared to the previous approaches, our method is able to imitate various effects efficiently and obtains more natural animation of turning page.

  4. Realistic Detectability of Close Interstellar Comets

    CERN Document Server

    Cook, Nathaniel V; Granvik, Mikael; Stephens, Denise C

    2016-01-01

    During the planet formation process, billions of comets are created and ejected into interstellar space. The detection and characterization of such interstellar comets (also known as extra-solar planetesimals or extra-solar comets) would give us in situ information about the efficiency and properties of planet formation throughout the galaxy. However, no interstellar comets have ever been detected, despite the fact that their hyperbolic orbits would make them readily identifiable as unrelated to the solar system. Moro-Mart\\'in et al. 2009 have made a detailed and reasonable estimate of the properties of the interstellar comet population. We extend their estimates of detectability with a numerical model that allows us to consider "close" interstellar comets, e.g., those that come within the orbit of Jupiter. We include several constraints on a "detectable" object that allow for realistic estimates of the frequency of detections expected from the Large Synoptic Survey Telescope (LSST) and other surveys. The inf...

  5. Teaching Practice in a Realistic Context

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    Introduction For two academic years, Teaching Practice (TP), an important component of the in-service Advanced Teacher Training Course at Chongqing University, was set up in an almost ideal context: students specially recruited, materials selected by the trainees and photo-copying facilities provided. While trainees felt very excited by their performances during TP, when all the excitement had gone, they felt less optimistic at the thought of the constraints which would be placed on their teaching in their own institutions. So their evaluation of TP ended with a "Yes, but" statement. Drawing on insights gained from those two years, the British lecturers and Chinese counterparts generally felt that TP should, in future, operate within a realistic context. In this paper, we shall report how TP was conducted within our Foreign Languages Department.

  6. A Simplified Model for Generating 3D Realistic Sound in the Multimedia and Virtual Reality Systems

    Institute of Scientific and Technical Information of China (English)

    赵Yu; 何志均; 等

    1996-01-01

    It is a key feature to embed 3D realistic sound effect in the future multimedia and virtual reality systems.Recent research on acoustics and psychoacoustics reveals the important cues for sound localization and sound perception.One promising approach to generate 3D realistic sound effect uses two earphones by simulating the sound waveforms from sound source to eardrum.This paper summarizes two methods for generating 3D realistic sound and points out their inherent drawbacks.To overcome these drawbacks we propose a simplified model to generate 3D realistic sound at any positions in the horizontal plane based on the results of sound perception and localization.Experimental results show that the model is correct and efficient.

  7. Validation of a realistic simulator for veterinary gastrointestinal endoscopy training.

    Science.gov (United States)

    Usón-Gargallo, Jesús; Usón-Casaús, Jesús M; Pérez-Merino, Eva M; Soria-Gálvez, Federico; Morcillo, Esther; Enciso, Silvia; Sánchez-Margallo, Francisco M

    2014-01-01

    This article reports on the face, content, and construct validity of a new realistic composite simulator (Simuldog) used to provide training in canine gastrointestinal flexible endoscopy. The basic endoscopic procedures performed on the simulator were esophagogastroduodenoscopy (EGD), gastric biopsy (GB), and gastric foreign body removal (FBR). Construct validity was assessed by comparing the performance of novices (final-year veterinary students and recent graduates without endoscopic experience, n=30) versus experienced subjects (doctors in veterinary medicine who had performed more than 50 clinical upper gastrointestinal endoscopic procedures as a surgeon, n=15). Tasks were scored based on completion time, and specific rating scales were developed to assess performance. Internal consistency and inter-rater agreement were assessed. Face and content validity were determined using a 5-point Likert-type scale questionnaire. The novices needed considerably more time than the experts to perform EGD, GB, and FBR, and their performance scores were significantly lower (pendoscopy scenarios were very realistic. The experts highly valued the usefulness of Simuldog for veterinary training and as a tool for assessing endoscopic skills. Simuldog is the first validated model specifically developed to be used as a training tool for endoscopy techniques in small animals.

  8. Functional consequences of realistic biodiversity changes in a marine ecosystem.

    Science.gov (United States)

    Bracken, Matthew E S; Friberg, Sara E; Gonzalez-Dorantes, Cirse A; Williams, Susan L

    2008-01-22

    Declines in biodiversity have prompted concern over the consequences of species loss for the goods and services provided by natural ecosystems. However, relatively few studies have evaluated the functional consequences of realistic, nonrandom changes in biodiversity. Instead, most designs have used randomly selected assemblages from a local species pool to construct diversity gradients. It is therefore difficult, based on current evidence, to predict the functional consequences of realistic declines in biodiversity. In this study, we used tide pool microcosms to demonstrate that the effects of real-world changes in biodiversity may be very different from those of random diversity changes. Specifically, we measured the relationship between the diversity of a seaweed assemblage and its ability to use nitrogen, a key limiting nutrient in nearshore marine systems. We quantified nitrogen uptake using both experimental and model seaweed assemblages and found that natural increases in diversity resulted in enhanced rates of nitrogen use, whereas random diversity changes had no effect on nitrogen uptake. Our results suggest that understanding the real-world consequences of declining biodiversity will require addressing changes in species performance along natural diversity gradients and understanding the relationships between species' susceptibility to loss and their contributions to ecosystem functioning.

  9. Neuronize: a tool for building realistic neuronal cell morphologies

    Science.gov (United States)

    Brito, Juan P.; Mata, Susana; Bayona, Sofia; Pastor, Luis; DeFelipe, Javier; Benavides-Piccione, Ruth

    2013-01-01

    This study presents a tool, Neuronize, for building realistic three-dimensional models of neuronal cells from the morphological information extracted through computer-aided tracing applications. Neuronize consists of a set of methods designed to build 3D neural meshes that approximate the cell membrane at different resolution levels, allowing a balance to be reached between the complexity and the quality of the final model. The main contribution of the present study is the proposal of a novel approach to build a realistic and accurate 3D shape of the soma from the incomplete information stored in the digitally traced neuron, which usually consists of a 2D cell body contour. This technique is based on the deformation of an initial shape driven by the position and thickness of the first order dendrites. The addition of a set of spines along the dendrites completes the model, building a final 3D neuronal cell suitable for its visualization in a wide range of 3D environments. PMID:23761740

  10. Realistic simulation of the Space-borne Compton Polarimeter POLAR

    Science.gov (United States)

    Xiao, Hualin

    2016-07-01

    POLAR is a compact wide field space-borne detector dedicated for precise measurements of the linear polarization of hard x-rays emitted by transient sources. Its energy range sensitivity is optimized for the detection of the prompt emission of Gamma-ray bursts (GRBs). POLAR is developed by an international collaboration of China, Switzerland and Poland. It is planned to be launched into space in 2016 onboard the Chinese space laboratory TG2. The energy range of POLAR spans between 50 keV and 500 keV. POLAR detects gamma rays with an array of 1600 plastic scintillator bars read out by 25 muti-anode PMTs (MAPMTs). Polarization measurements use Compton scattering process and are based on detection of energy depositions in the scintillator bars. Reconstruction of the polarization degree and polarization angle of GRBs requires comparison of experimental modulation curves with realistic simulations of the full instrument response. In this paper we present a method to model and parameterize the detector response including efficiency of the light collection, contributions from crosstalk and non-uniformity of MAPMTs as well as dependency on low energy detection thresholds and noise from readout electronics. The performance of POLAR for determination of polarization is predicted with such realistic simulations and carefully cross-checked with dedicated laboratory tests.

  11. Realistically Rendering SoC Traffic Patterns with Interrupt Awareness

    DEFF Research Database (Denmark)

    Angiolini, Frederico; Mahadevan, Sharkar; Madsen, Jan;

    2005-01-01

    traffic generators have been used to overcome such an issue. However, target applications increasingly present non-trivial execution flows and synchronization patterns, especially in presence of underlying operating systems and when exploiting interrupt facilities. This property makes it very difficult...... to generate realistic test traffic. This paper presents a selection of applications using interrupt-based synchronization; a reference methodology to split such applications in execution subflows and to adjust the overall execution stream based upon hardware events; a reactive simulation device capable......In Multi-Processor System-on-Chip (MPSoC) design stages, accurate modeling of IP behaviour is crucial to analyze interconnect effectiveness. However, parallel development of components may cause IP core models to be still unavailable when tuning communication performance. Traditionally, synthetic...

  12. Pricing European Options in Realistic Markets

    CERN Document Server

    Schaden, M

    2002-01-01

    We investigate the relation between the fair price for European-style vanilla options and the distribution of short-term returns on the underlying asset ignoring transaction and other costs. We compute the risk-neutral probability density conditional on the total variance of the asset's returns when the option expires. If the asset's future price has finite expectation, the option's fair value satisfies a parabolic partial differential equation of the Black-Scholes type in which the variance of the asset's returns rather than a trading time is the evolution parameter. By immunizing the portfolio against large-scale price fluctuations of the asset, the valuation of options is extended to the realistic case\\cite{St99} of assets whose short-term returns have finite variance but very large, or even infinite, higher moments. A dynamic Delta-hedged portfolio that is statically insured against exceptionally large fluctuations includes at least two different options on the asset. The fair value of an option in this c...

  13. Cerebral blood flow simulations in realistic geometries

    Directory of Open Access Journals (Sweden)

    Szopos Marcela

    2012-04-01

    Full Text Available The aim of this work is to perform the computation of the blood flow in all the cerebral network, obtained from medical images as angiographies. We use free finite elements codes as FreeFEM++. We first test the code on analytical solutions in simplified geometries. Then, we study the influence of boundary conditions on the flow and we finally perform first computations on realistic meshes. L’objectif est ici de simuler l’écoulement sanguin dans tout le réseau cérébral (artériel et veineux obtenu à partir d’angiographies cérébrales 3D à l’aide de logiciels d’éléments finis libres, comme FreeFEM++. Nous menons d’abord une étude détaillée des résultats sur des solutions analytiques et l’influence des conditions limites à imposer dans des géométries simplifiées avant de travailler sur les maillages réalistes.

  14. Sialendoscopy Training: Presentation of a Realistic Model.

    Science.gov (United States)

    Pascoto, Gabriela Robaskewicz; Stamm, Aldo Cassol; Lyra, Marcos

    2017-01-01

    Introduction Several surgical training simulators have been created for residents and young surgeons to gain experience with surgical procedures. Laboratory training is fundamental for acquiring familiarity with the techniques of surgery and skill in handing instruments. Objective The aim of this study is to present a novel simulator for training sialendoscopy. Method This realistic simulator was built with a synthetic thermo-retractile, thermo-sensible rubber which, when combined with different polymers, produces more than 30 different formulas. These formulas present textures, consistencies, and mechanical resistance are similar to many human tissues. Results The authors present a training model to practice sialendoscopy. All aspects of the procedure are simulated: month opening, dilatation of papillae, insert of the scope, visualization of stones, extraction of these stones with grasping or baskets, and finally, stone fragmentation with holmium laser. Conclusion This anatomical model for sialendoscopy training should be considerably useful to abbreviate the learning curve during the qualification of young surgeons while minimizing the consequences of technical errors.

  15. Publishing Set-Valued Data Against Realistic Adversaries

    Institute of Scientific and Technical Information of China (English)

    Jun-Qiang Liu

    2012-01-01

    Privacy protection in publishing set-valued data is an important problem.However,privacy notions proposed in prior works either assume that the adversary has unbounded knowledge and hence provide over-protection that causes excessive distortion,or ignore the knowledge about the absence of certain items and do not prevent attacks based on such knowledge.To address these issues,we propose a new privacy notion,(k,e)(m,n)-privacy,which prevents both the identity disclosure and the sensitive item disclosure to a realistic privacy adversary who has bounded knowledge about the presence of items and the bounded knowledge about the absence of items.In addition to the new notion,our contribution is an efficient algorithm that finds a near-optimal solution and is applicable for anonymizing real world databases.Extensive experiments on real world databases showed that our algorithm outperforms the state of the art algorithms.

  16. Realistic estimate of valence transversity from dihadron production

    CERN Document Server

    Radici, Marco

    2015-01-01

    We have updated our extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. The most recent COMPASS data for proton and deuteron targets, complemented by previous HERMES data on the proton, make it possible to perform a flavor separation of the valence components of the transversity distribution, using di-hadron fragmentation functions taken from the semi-inclusive production of two pion pairs in back-to-back jets in $e^+ e^-$ annihilation. The $e^+ e^-$ data from BELLE have been reanalyzed to reach a more realistic estimate of the uncertainties on the chiral-odd interference fragmentation function. Our results represent the most accurate estimate of the uncertainties on the valence components of the transversity distribution currently available.

  17. Realistic estimate of valence transversity distributions from inclusive dihadron production

    CERN Document Server

    Radici, Marco; Bacchetta, Alessandro; Guagnelli, Marco

    2015-01-01

    We present an updated extraction of the transversity parton distribution based on the analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets in collinear factorization. Data for proton and deuteron targets make it possible to perform a flavor separation of the valence components of the transversity distribution, using di-hadron fragmentation functions taken from the semi-inclusive production of two pion pairs in back-to-back jets in e+e- annihilation. The e+e- data from Belle have been reanalyzed using the replica method and a more realistic estimate of the uncertainties on the chiral-odd interference fragmentation function has been obtained. Then, the transversity distribution has been extracted by using the most recent and more precise COMPASS data for deep-inelastic scattering off proton targets. Our results represent the most accurate estimate of the uncertainties on the valence components of the transversity distribution currently available.

  18. Realistic Mobility Modeling for Vehicular Ad Hoc Networks

    Science.gov (United States)

    Akay, Hilal; Tugcu, Tuna

    2009-08-01

    Simulations used for evaluating the performance of routing protocols for Vehicular Ad Hoc Networks (VANET) are mostly based on random mobility and fail to consider individual behaviors of the vehicles. Unrealistic assumptions about mobility produce misleading results about the behavior of routing protocols in real deployments. In this paper, a realistic mobility modeling tool, Mobility for Vehicles (MOVE), which considers the basic mobility behaviors of vehicles, is proposed for a more accurate evaluation. The proposed model is tested against the Random Waypoint (RWP) model using AODV and OLSR protocols. The results show that the mobility model significantly affects the number of nodes within the transmission range of a node, the volume of control traffic, and the number of collisions. It is shown that number of intersections, grid size, and node density are important parameters when dealing with VANET performance.

  19. Generalized seniority with realistic interactions in open-shell nuclei

    CERN Document Server

    Caprio, M A; Cai, K; Constantinou, Ch; Hellemans, V

    2014-01-01

    Generalized seniority provides a truncation scheme for the nuclear shell model, based on pairing correlations, which offers the possibility of dramatically reducing the dimensionality of the nuclear shell-model problem. Systematic comparisons against results obtained in the full shell-model space are required to assess the viability of this scheme. Here, we extend recent generalized seniority calculations for semimagic nuclei, the Ca isotopes, to open-shell nuclei, with both valence protons and valence neutrons. The even-mass Ti and Cr isotopes are treated in a full major shell and with realistic interactions, in the generalized seniority scheme with one broken proton pair and one broken neutron pair. Results for level energies, orbital occupations, and electromagnetic observables are compared with those obtained in the full shell-model space. We demonstrate that, even for the Ti isotopes, significant benefit would be obtained in going beyond the approximation of one broken pair of each type, while the Cr iso...

  20. Finite Time Blowup in a Realistic Food-Chain Model

    KAUST Repository

    Parshad, Rana

    2013-05-19

    We investigate a realistic three-species food-chain model, with generalist top predator. The model based on a modified version of the Leslie-Gower scheme incorporates mutual interference in all the three populations and generalizes several other known models in the ecological literature. We show that the model exhibits finite time blowup in certain parameter range and for large enough initial data. This result implies that finite time blowup is possible in a large class of such three-species food-chain models. We propose a modification to the model and prove that the modified model has globally existing classical solutions, as well as a global attractor. We reconstruct the attractor using nonlinear time series analysis and show that it pssesses rich dynamics, including chaos in certain parameter regime, whilst avoiding blowup in any parameter regime. We also provide estimates on its fractal dimension as well as provide numerical simulations to visualise the spatiotemporal chaos.

  1. Chinese Infrastructure in South Asia: A Realist and Liberal Perspective

    Science.gov (United States)

    2015-12-01

    creation of a win-win environment throughout the Indian Ocean region, realist scholars argue that China’s motivations are to utilize this... environment throughout the Indian Ocean region, realist scholars argue that China’s motivations are to utilize this infrastructure to create...NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA THESIS Approved for public release; distribution is unlimited CHINESE

  2. Realistic CT simulation using the 4D XCAT phantom.

    Science.gov (United States)

    Segars, W P; Mahesh, M; Beck, T J; Frey, E C; Tsui, B M W

    2008-08-01

    The authors develop a unique CT simulation tool based on the 4D extended cardiac-torso (XCAT) phantom, a whole-body computer model of the human anatomy and physiology based on NURBS surfaces. Unlike current phantoms in CT based on simple mathematical primitives, the 4D XCAT provides an accurate representation of the complex human anatomy and has the advantage, due to its design, that its organ shapes can be changed to realistically model anatomical variations and patient motion. A disadvantage to the NURBS basis of the XCAT, however, is that the mathematical complexity of the surfaces makes the calculation of line integrals through the phantom difficult. They have to be calculated using iterative procedures; therefore, the calculation of CT projections is much slower than for simpler mathematical phantoms. To overcome this limitation, the authors used efficient ray tracing techniques from computer graphics, to develop a fast analytic projection algorithm to accurately calculate CT projections directly from the surface definition of the XCAT phantom given parameters defining the CT scanner and geometry. Using this tool, realistic high-resolution 3D and 4D projection images can be simulated and reconstructed from the XCAT within a reasonable amount of time. In comparison with other simulators with geometrically defined organs, the XCAT-based algorithm was found to be only three times slower in generating a projection data set of the same anatomical structures using a single 3.2 GHz processor. To overcome this decrease in speed would, therefore, only require running the projection algorithm in parallel over three processors. With the ever decreasing cost of computers and the rise of faster processors and multi-processor systems and clusters, this slowdown is basically inconsequential, especially given the vast improvement the XCAT offers in terms of realism and the ability to generate 3D and 4D data from anatomically diverse patients. As such, the authors conclude

  3. Maximizing the Delivery of MPR Broadcasting Under Realistic Physical Layer Assumptions

    Institute of Scientific and Technical Information of China (English)

    Francois Ingelrest; David Simplot-Ryl

    2008-01-01

    It is now commonly accepted that the unit disk graph used to model the physical layer in wireless network sdoes not reflect real radio transmissions, and that a more realistic model should be considered for experimental simulations.Previous work on realistic scenarios has been focused on unicast, however broadcast requirements are fundamentally different and cannot be derived from the unicast case. There fore, the broadcast protocols must be adapted in order to still be efficient under realistic assumptions. In this paper, we study the well-known multipoint relay broadcast protocol (MPR), in which each node has to choose a set of 1-hop neighbors to act as relays in order to cover the whole 2-hop neighborhood. We giveexperimental results showing that the original strategy used to select these multipoint relays does not suit a realistic model.On the basis of these results, we propose new selection strategies solely based on link quality. One of the key aspects of our solutions is that our strategies do not require any additional hardware and may be implemented at the application layer,which is particularly relevant to the context of ad hoc and sensor networks where energy savings are mandatory. We finall yprovide new experimental results that demonstrate the superiority of our strategies under realistic physical assumptions.

  4. Realistic Modeling of Wireless Network Environments

    Science.gov (United States)

    2015-03-01

    1 2.0 INTRODUCTION ... SCM ) .................................................................................................. 8 3.3.3 RF Front Ends...3 Figure 2: SCM -based Emulator (top) Connecting Two Nodes (bottom

  5. Combining Street View and Aerial Images to Create Photo-Realistic 3D City Models

    OpenAIRE

    Ivarsson, Caroline

    2014-01-01

    This thesis evaluates two different approaches of using panoramic street view images for creating more photo-realistic 3D city models comparing to 3D city models based on only aerial images. The thesis work has been carried out at Blom Sweden AB with the use of their software and data. The main purpose of this thesis work has been to investigate if street view images can aid in creating more photo-realistic 3D city models on street level through an automatic or semi-automatic approach. Two di...

  6. A realistic treatment of geomagnetic Cherenkov radiation from cosmic ray air showers

    NARCIS (Netherlands)

    Werner, Klaus; de Vries, Krijn D.; Scholten, Olaf

    2012-01-01

    We present a macroscopic calculation of coherent electro-magnetic radiation from air showers initiated by ultra-high energy cosmic rays, based on currents obtained from three-dimensional Monte Carlo simulations of air showers in a realistic geo-magnetic field. We discuss the importance of a correct

  7. Realist Stronghold in the Land of Thucydides? - Appraising and Resisting a Realist Tradition in Greece

    Directory of Open Access Journals (Sweden)

    Kyriakos Mikelis

    2015-10-01

    Full Text Available Given the integration of the discipline of International Relations in Greece into the global discipline since a few decades, the article addresses the reflection of the ‘realism in and for the globe’ question to this specific case. Although the argument doesn’t go as far as to ‘recover’ forgotten IR theorists or self-proclaimed realists, a geopolitical dimension of socio-economic thought during interwar addressed concerns which could be related to the intricacies of realpolitik. Then again at current times, certain scholars have been eager to maintain a firm stance in favor of realism, focusing on the work of ancient figures, especially Thucydides or Homer, and on questions of the offensive-defensive realism debate as well as on the connection with the English School, while others have offered fruitful insights matching the broad constructivist agenda. Overall, certain genuine arguments have appeared, reflecting diversified views about sovereignty and its function or mitigation.

  8. Student Work Experience: A Realistic Approach to Merchandising Education.

    Science.gov (United States)

    Horridge, Patricia; And Others

    1980-01-01

    Relevant and realistic experiences are needed to prepare the student for a future career. Addresses the results of a survey of colleges and universities in the United States in regard to their student work experience (SWE) in fashion merchandising. (Author)

  9. Three-neutron resonance trajectories for realistic interaction models

    CERN Document Server

    Lazauskas, R

    2005-01-01

    Three-neutron resonances are searched using realistic nucleon-nucleon interaction models. Resonance pole trajectories were explored by artificially binding three-neutron and then gradually removing additional interaction. The final pole positions for three-neutron states up to $|J|$=5/2 finish in the fourth energy quadrant with Re(E)$\\leqslant0$ before additional interaction is removed. This study shows that realistic nucleon-nucleon interaction models exclude possible existence of observable three-neutron resonances.

  10. Blending critical realist and emancipatory practice development methodologies: making critical realism work in nursing research.

    LENUS (Irish Health Repository)

    Parlour, Randal

    2012-12-01

    This paper examines the efficacy of facilitation as a practice development intervention in changing practice within an Older Person setting and in implementing evidence into practice. It outlines the influences exerted by the critical realist paradigm in guiding emancipatory practice development activities and, in particular, how the former may be employed within an emancipatory practice development study to elucidate and increase understanding pertinent to causation and outcomes. The methodology is based upon an emancipatory practice development approach set within a realistic evaluation framework. This allows for systematic analysis of the social and contextual elements that influence the explication of outcomes associated with facilitation. The study is concentrated upon five practice development cycles, within which a sequence of iterative processes is integrated. The authors assert that combining critical realist and emancipatory processes offers a robust and practical method for translating evidence and implementing changes in practice, as the former affirms or falsifies the influence that emancipatory processes exert on attaining culture shift, and enabling transformation towards effective clinical practice. A new framework for practice development is proposed that establishes methodological coherency between emancipatory practice development and realistic evaluation. This augments the existing theoretical bases for both these approaches by contributing new theoretical and methodological understandings of causation.

  11. Automatic procedure for realistic 3D finite element modelling of human brain for bioelectromagnetic computations

    Energy Technology Data Exchange (ETDEWEB)

    Aristovich, K Y; Khan, S H, E-mail: kirill.aristovich.1@city.ac.u [School of Engineering and Mathematical Sciences, City University London, Northampton Square, London EC1V 0HB (United Kingdom)

    2010-07-01

    Realistic computer modelling of biological objects requires building of very accurate and realistic computer models based on geometric and material data, type, and accuracy of numerical analyses. This paper presents some of the automatic tools and algorithms that were used to build accurate and realistic 3D finite element (FE) model of whole-brain. These models were used to solve the forward problem in magnetic field tomography (MFT) based on Magnetoencephalography (MEG). The forward problem involves modelling and computation of magnetic fields produced by human brain during cognitive processing. The geometric parameters of the model were obtained from accurate Magnetic Resonance Imaging (MRI) data and the material properties - from those obtained from Diffusion Tensor MRI (DTMRI). The 3D FE models of the brain built using this approach has been shown to be very accurate in terms of both geometric and material properties. The model is stored on the computer in Computer-Aided Parametrical Design (CAD) format. This allows the model to be used in a wide a range of methods of analysis, such as finite element method (FEM), Boundary Element Method (BEM), Monte-Carlo Simulations, etc. The generic model building approach presented here could be used for accurate and realistic modelling of human brain and many other biological objects.

  12. From minimal to realistic SU(5)

    CERN Document Server

    Feruglio, Ferruccio

    2001-01-01

    We discuss baryon and lepton violation in the context of a simple 5-dimensional grand unified model, based on the orbifold S^1/(Z_2 x Z_2'). While gauge and Higgs degrees of freedom live in the bulk, matter is located on the boundaries of the space-time. We show that proton decay is naturally suppressed or even forbidden by suitable implementations of the parity symmetries in the matter sector. The corresponding mechanism does not affect the SU(5) description of fermion masses also including neutrinos.

  13. Radiative transfer in closely packed realistic regoliths

    Directory of Open Access Journals (Sweden)

    S. Vahidinia

    2011-09-01

    Full Text Available We have developed a regolith radiative transfer model (RRT based on a first-principles approach to regolith modeling that is essential for near-to-far infrared observations of grainy surfaces, and is readily configured to answer fundamental questions about popular models with which all remote observations of all airless solar system bodies with granular surfaces are currently interpreted. Our model accounts for wavelength-size regolith particles which are closely packed and can be heterogeneous in composition and arbitrarily shaped. Here we present preliminary results showing the role of porosity on layer reflectivity.

  14. Simulating single photons with realistic photon sources

    Science.gov (United States)

    Yuan, Xiao; Zhang, Zhen; Lütkenhaus, Norbert; Ma, Xiongfeng

    2016-12-01

    Quantum information processing provides remarkable advantages over its classical counterpart. Quantum optical systems have been proved to be sufficient for realizing general quantum tasks, which, however, often rely on single-photon sources. In practice, imperfect single-photon sources, such as a weak-coherent-state source, are used instead, which will inevitably limit the power in demonstrating quantum effects. For instance, with imperfect photon sources, the key rate of the Bennett-Brassard 1984 (BB84) quantum key distribution protocol will be very low, which fortunately can be resolved by utilizing the decoy-state method. As a generalization, we investigate an efficient way to simulate single photons with imperfect ones to an arbitrary desired accuracy when the number of photonic inputs is small. Based on this simulator, we can thus replace the tasks that involve only a few single-photon inputs with the ones that make use of only imperfect photon sources. In addition, our method also provides a quantum simulator to quantum computation based on quantum optics. In the main context, we take a phase-randomized coherent state as an example for analysis. A general photon source applies similarly and may provide some further advantages for certain tasks.

  15. Towards a realistic F-theory GUT

    Science.gov (United States)

    Callaghan, James C.; King, Stephen F.; Leontaris, George K.; Ross, Graham G.

    2012-04-01

    We consider semi-local F-theory GUTs arising from a single E 8 point of local enhancement, leading to simple GUT groups based on E 6, SO(10) and SU(5) with SU(3), SU(4) and SU(5) spectral covers, respectively. Assuming the minimal {{Z}_2} monodromy, we determine the homology classes and the associated spectra after flux breaking for each case. Using these results we construct an E 6 based model that demonstrates, for the first time, that it is possible to construct a phenomenologically viable model which leads to the MSSM at low energies. The exotics that result from flux breaking all get a large mass when singlet fields acquire vacuum expectation values driven by D- and F-flatness. Due to the underlying GUT symmetry and the U(1)s descending from E 8, bare baryon- and lepton-number violating terms are forbidden up to and including dimension 5. As a result nucleon decay is naturally suppressed below present bounds. The μ-term is generated by non-perturbative U(1) breaking effects. After including the effect of flux and instanton corrections acceptable quark and charged lepton masses and mixing angles can be obtained. Neutrinos get a mass from the see-saw mechanism through their coupling to singlet neutrinos that acquire large Majorana mass as a result of the monodromy.

  16. Towards a Realistic F-theory GUT

    CERN Document Server

    Callaghan, James C; Leontaris, George K; Ross, Graham G

    2011-01-01

    We consider semi-local F-theory GUTs arising from a single E_8 point of local enhancement, leading to simple GUT groups based on E_6, SO(10) and SU(5) with SU(3), SU(4) and SU(5) spectral covers, respectively. Assuming the minimal Z_2 monodromy, we determine the homology classes and the associated spectra after flux breaking for each case. Our analysis includes the GUT singlets which have hitherto been ignored but which play a crucial role in phenomenology. Using these results we construct an E_6 based model that demonstrates, for the first time, that it is possible to construct a phenomenologically viable model which leads to the MSSM at low energies. The exotics that result from flux breaking all get a large mass when singlet fields acquire vacuum expectation values driven by D- and F-flatness. Due to the underlying GUT symmetry and the U(1)s descending from E_8, bare baryon- and lepton-number violating terms are forbidden up to and including dimension 5. As a result nucleon decay is naturally suppressed be...

  17. A realistic 3+1D Viscous Hydro Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Romatschke, Paul [Univ. of Colorado, Boulder, CO (United States)

    2015-05-31

    DoE funds were used as bridge funds for the faculty position for the PI at the University of Colorado. The total funds for the Years 3-5 of the JET Topical Collaboration amounted to about 50 percent of the academic year salary of the PI.The PI contributed to the JET Topical Collaboration by developing, testing and applying algorithms for a realistic simulation of the bulk medium created in relativistic ion collisions.Specifically, two approaches were studied, one based on a new Lattice-Boltzmann (LB) framework, and one on a more traditional viscous hydro-dynamics framework. Both approaches were found to be viable in principle, with the LB approach being more elegant but needing still more time to develop.The traditional approach led to the super-hybrid model of ion collisions dubbed 'superSONIC', and has been successfully used for phenomenology of relativistic heavy-ion and light-on-heavy-ion collisions.In the time-frame of the JET Topical Collaboration, the Colorado group has published 15 articles in peer-reviewed journals, three of which were published in Physical Review Letters. The group graduated one Master student during this time-frame and two more PhD students are expected to graduate in the next few years. The PI has given more than 28 talks and presentations during this period.

  18. Realistic Data-Driven Traffic Flow Animation Using Texture Synthesis.

    Science.gov (United States)

    Chao, Qianwen; Deng, Zhigang; Ren, Jiaping; Ye, Qianqian; Jin, Xiaogang

    2017-01-11

    We present a novel data-driven approach to populate virtual road networks with realistic traffic flows. Specifically, given a limited set of vehicle trajectories as the input samples, our approach first synthesizes a large set of vehicle trajectories. By taking the spatio-temporal information of traffic flows as a 2D texture, the generation of new traffic flows can be formulated as a texture synthesis process, which is solved by minimizing a newly developed traffic texture energy. The synthesized output captures the spatio-temporal dynamics of the input traffic flows, and the vehicle interactions in it strictly follow traffic rules. After that, we position the synthesized vehicle trajectory data to virtual road networks using a cage-based registration scheme, where a few traffic-specific constraints are enforced to maintain each vehicle's original spatial location and synchronize its motion in concert with its neighboring vehicles. Our approach is intuitive to control and scalable to the complexity of virtual road networks. We validated our approach through many experiments and paired comparison user studies.

  19. Improved transcranial magnetic stimulation coil design with realistic head modeling

    Science.gov (United States)

    Crowther, Lawrence; Hadimani, Ravi; Jiles, David

    2013-03-01

    We are investigating Transcranial magnetic stimulation (TMS) as a noninvasive technique based on electromagnetic induction which causes stimulation of the neurons in the brain. TMS can be used as a pain-free alternative to conventional electroconvulsive therapy (ECT) which is still widely implemented for treatment of major depression. Development of improved TMS coils capable of stimulating subcortical regions could also allow TMS to replace invasive deep brain stimulation (DBS) which requires surgical implantation of electrodes in the brain. Our new designs allow new applications of the technique to be established for a variety of diagnostic and therapeutic applications of psychiatric disorders and neurological diseases. Calculation of the fields generated inside the head is vital for the use of this method for treatment. In prior work we have implemented a realistic head model, incorporating inhomogeneous tissue structures and electrical conductivities, allowing the site of neuronal activation to be accurately calculated. We will show how we utilize this model in the development of novel TMS coil designs to improve the depth of penetration and localization of stimulation produced by stimulator coils.

  20. Realistic packed bed generation using small numbers of spheres

    Energy Technology Data Exchange (ETDEWEB)

    Pavlidis, D., E-mail: dimitrios.pavlidis04@imperial.ac.uk; Lathouwers, D.

    2013-10-15

    Highlights: • A method for generating 3D, periodic, closely packed beds of small numbers (<50) of spheres is presented. • The method is able to reproduce characteristics for the entirety (including nearwall area) of a randomly stacked bed. • Results are in good agreement with reference numerical data. -- Abstract: A method for stochastically generating three-dimensional, periodic, closely packed beds of small numbers (less than 50) of spheres is presented. This is an essential and integral part of realistic modelling of fluid flow and heat transfer through packed beds. In order to be able to reproduce the entirety of these complex geometries (in the radial direction) using small numbers of spheres, they are divided into two regions: the near-wall region (up to 4–5 sphere diameters from the solid wall in the wall-normal direction) and the core region. Near-wall stackings are doubly periodic and include a solid wall, while core stackings are triply periodic. A computational method for generating such geometries is presented for each region. Both are based on overlap removal methods. Results are compared against reference numerical data. Diagnostics used to evaluate the models include average packing fractions and coordination numbers, porosity profiles and distributions of the angle between two spheres which touch a common neighbour. Results are in good qualitative and quantitative agreement with the available reference data.

  1. Generating Realistic Labelled, Weighted Random Graphs

    CERN Document Server

    Davis, Michael Charles; Liu, Weiru; Miller, Paul; Hunter, Ruth; Kee, Frank

    2015-01-01

    Generative algorithms for random graphs have yielded insights into the structure and evolution of real-world networks. Most networks exhibit a well-known set of properties, such as heavy-tailed degree distributions, clustering and community formation. Usually, random graph models consider only structural information, but many real-world networks also have labelled vertices and weighted edges. In this paper, we present a generative model for random graphs with discrete vertex labels and numeric edge weights. The weights are represented as a set of Beta Mixture Models (BMMs) with an arbitrary number of mixtures, which are learned from real-world networks. We propose a Bayesian Variational Inference (VI) approach, which yields an accurate estimation while keeping computation times tractable. We compare our approach to state-of-the-art random labelled graph generators and an earlier approach based on Gaussian Mixture Models (GMMs). Our results allow us to draw conclusions about the contribution of vertex labels a...

  2. Trends in hydrodesulfurization catalysis based on realistic surface models

    DEFF Research Database (Denmark)

    Moses, P.G.; Grabow, L.C.; Fernandez Sanchez, Eva

    2014-01-01

    Trends in hydrodesulfurization (HDS) activity are investigated on the basis of surface properties calculated by density functional theory for a series of HDS catalysts. It is shown that approximately linear correlations exist between HS group binding energies and activation barriers of key elemen...

  3. Realistic Crowd Simulation with Density-Based Path Planning

    NARCIS (Netherlands)

    van Toll, W.G.; Cook IV, A.F.; Geraerts, R.J.

    2012-01-01

    Virtual characters in games and simulations often need to plan visually convincing paths through a crowded environment. This paper describes how crowd density information can be used to guide a large number of characters through a crowded environment. Crowd density information helps characters avoid

  4. Realistic humanoid robot simulation with an optimized controller: a power consumption minimization approach

    OpenAIRE

    2008-01-01

    This paper describes a humanoid robot simulator supporting joint trajectory optimization, following accurately the real robot characteristics. The simulator, based on a rigid body simulator (Open Dynamics Engine) and an OpenGL based graphics library (GLScene), provides instant visual feedback and realistic dynamics. It allows to design and test behaviours and control methods without access to the real hardware, preventing damages in the real robot in the earlier stages of development. Having ...

  5. Surface Detail Capturing for Realistic Facial Animation

    Institute of Scientific and Technical Information of China (English)

    Pei-Hsuan Tu; I-Chen Lin; Jeng-Sheng Yeh; Rung-Huei Liang; Ming Ouhyoung

    2004-01-01

    In this paper, a facial animation system is proposed for capturing both geometrical information and illumination changes of surface details, called expression details, from video clips simultaneously, and the captured data can be widely applied to different 2D face images and 3D face models. While tracking the geometric data,we record the expression details by ratio images. For 2D facial animation synthesis, these ratio images are used to generate dynamic textures. Because a ratio image is obtained via dividing colors of an expressive face by those of a neutral face, pixels with ratio value smaller than one are where a wrinkle or crease appears. Therefore, the gradients of the ratio value at each pixel in ratio images are regarded as changes of a face surface, and original normals on the surface can be adjusted according to these gradients. Based on this idea, we can convert the ratio images into a sequence of normal maps and then apply them to animated 3D model rendering. With the expression detail mapping, the resulted facial animations are more life-like and more expressive.

  6. Generating Realistic Labelled, Weighted Random Graphs

    Directory of Open Access Journals (Sweden)

    Michael Charles Davis

    2015-12-01

    Full Text Available Generative algorithms for random graphs have yielded insights into the structure and evolution of real-world networks. Most networks exhibit a well-known set of properties, such as heavy-tailed degree distributions, clustering and community formation. Usually, random graph models consider only structural information, but many real-world networks also have labelled vertices and weighted edges. In this paper, we present a generative model for random graphs with discrete vertex labels and numeric edge weights. The weights are represented as a set of Beta Mixture Models (BMMs with an arbitrary number of mixtures, which are learned from real-world networks. We propose a Bayesian Variational Inference (VI approach, which yields an accurate estimation while keeping computation times tractable. We compare our approach to state-of-the-art random labelled graph generators and an earlier approach based on Gaussian Mixture Models (GMMs. Our results allow us to draw conclusions about the contribution of vertex labels and edge weights to graph structure.

  7. Sustainability and meat consumption: is reduction realistic?

    Directory of Open Access Journals (Sweden)

    Jantine Voordouw

    2013-10-01

    Full Text Available Meat is critical with respect to sustainability because meat products are among the most energy-intensive and ecologically burdensome foods. Empirical studies of the meat-consumption frequency of Dutch consumers show that, apart from meat-avoiders and meat-eaters, many people are meat-reducers that eat no meat at least one day per week. Meat-consumption frequencies provide empirical evidence for different modes of “flexitarianism,” including light, medium, and heavy flexitarians. In particular, the existence of heavy flexitarians suggests that the customary position of meat and other animal-based dietary products in the food hierarchy is not inviolable. To improve our understanding of meat reduction, cluster analysis adds information about differences across flexitarians. Given the enormous environmental impact of animal-protein consumption and the apparent sympathy of consumers for meat reduction, it is surprising that politicians and policy makers demonstrate little, if any, interest in strategies to reduce meat consumption and to encourage more sustainable eating practices.

  8. Order Matters: Sequencing Scale-Realistic Versus Simplified Models to Improve Science Learning

    Science.gov (United States)

    Chen, Chen; Schneps, Matthew H.; Sonnert, Gerhard

    2016-10-01

    Teachers choosing between different models to facilitate students' understanding of an abstract system must decide whether to adopt a model that is simplified and striking or one that is realistic and complex. Only recently have instructional technologies enabled teachers and learners to change presentations swiftly and to provide for learning based on multiple models, thus giving rise to questions about the order of presentation. Using disjoint individual growth modeling to examine the learning of astronomical concepts using a simulation of the solar system on tablets for 152 high school students (age 15), the authors detect both a model effect and an order effect in the use of the Orrery, a simplified model that exaggerates the scale relationships, and the True-to-scale, a proportional model that more accurately represents the realistic scale relationships. Specifically, earlier exposure to the simplified model resulted in diminution of the conceptual gain from the subsequent realistic model, but the realistic model did not impede learning from the following simplified model.

  9. When threats foreign turn domestic: Two ways for distant realistic intergroup threats to carry over into local intolerance.

    Science.gov (United States)

    Bouman, Thijs; van Zomeren, Martijn; Otten, Sabine

    2015-09-01

    In times of economic downturn, perceived realistic intergroup threats (e.g., labour competition) often dominate political and media discourse. Although local outgroups (e.g., local immigrants) can be experienced as sources of realistic threats, we propose that such threats can also be perceived to be caused by distant outgroups (e.g., European Union members perceiving Greece to threaten their economies) and that such distant threats can carry over into local intolerance (e.g., increasing intolerance towards local immigrant groups). We predicted and found in two studies that perceived distant realistic threats carried over into local intolerance via two different pathways. First, direct reactions towards the distant outgroup can generalize to culturally similar local outgroups (the group-based association pathway). Secondly, Study 2 indicated that when the distant threat was attributed to stereotypical outgroup traits (e.g., being lazy), distant realistic threats activated local realistic threats, which subsequently influenced local intolerance (the threat-based association pathway). Taken together, our studies indicate that perceived realistic threats foreign can turn domestic, but in two different ways.

  10. Simulation of Magnetic Phenomena at Realistic Interfaces

    KAUST Repository

    Grytsyuk, Sergiy

    2016-02-04

    In modern technology exciting developments are related to the ability to understand and control interfaces. Particularly, magnetic interfaces revealing spindependent electron transport are of great interest for modern spintronic devices, such as random access memories and logic devices. From the technological point of view, spintronic devices based on magnetic interfaces enable manipulation of the magnetism via an electric field. Such ability is a result of the different quantum effects arising from the magnetic interfaces (for example, spin transfer torque or spin-orbit torque) and it can reduce the energy consumption as compared to the traditional semiconductor electronic devices. Despite many appealing characteristics of these materials, fundamental understanding of their microscopic properties and related phenomena needs to be established by thorough investigation. In this work we implement first principles calculations in order to study the structural, electric, and magnetic properties as well as related phenomena of two types of interfaces with large potential in spintronic applications: 1) interfaces between antiferromagnetic 3d-metal-oxides and ferromagnetic 3d-metals and 2) interfaces between non-magnetic 5d(4d)- and ferromagnetic 3d-metals. A major difficulty in studying such interfaces theoretically is the typically large lattice mismatch. By employing supercells with Moir e patterns, we eliminate the artificial strain that leads to doubtful results and are able to describe the dependence of the atomic density at the interfaces on the component materials and their thicknesses. After establishing understanding about the interface structures, we investigate the electronic and magnetic properties. A Moir e supercell with transition layer is found to reproduce the main experimental findings and thus turns out to be the appropriate model for simulating magnetic misfit interfaces. In addition, we systematically study the magnetic anisotropy and Rashba band

  11. Realistic real-time outdoor rendering in augmented reality.

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

    Full Text Available Realistic rendering techniques of outdoor Augmented Reality (AR has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps. Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems.

  12. Principles of maximally classical and maximally realistic quantum mechanics

    Indian Academy of Sciences (India)

    S M Roy

    2002-08-01

    Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2-dimensional phase space, a maximally realistic quantum mechanics can have quantum probabilities of no more than + 1 complete commuting cets (CCS) of observables coexisting as marginals of one positive phase space density. Here I formulate a stationary principle which gives a nonperturbative definition of a maximally classical as well as maximally realistic phase space density. I show that the maximally classical trajectories are in fact exactly classical in the simple examples of coherent states and bound states of an oscillator and Gaussian free particle states. In contrast, it is known that the de Broglie–Bohm realistic theory gives highly nonclassical trajectories.

  13. Performance Evaluation of Realistic Vanet Using Traffic Light Scenario

    CERN Document Server

    Nidhi,

    2012-01-01

    Vehicular Ad-hoc Networks (VANETs) is attracting considerable attention from the research community and the automotive industry to improve the services of Intelligent Transportation System (ITS). As today's transportation system faces serious challenges in terms of road safety, efficiency, and environmental friendliness, the idea of so called "ITS" has emerged. Due to the expensive cost of deployment and complexity of implementing such a system in real world, research in VANET relies on simulation. This paper attempts to evaluate the performance of VANET in a realistic environment. The paper contributes by generating a real world road Map of JNU using existing Google Earth and GIS tools. Traffic data from a limited region of road Map is collected to capture the realistic mobility. In this work, the entire region has been divided into various smaller routes. The realistic mobility model used here considers the driver's route choice at the run time. It also studies the clustering effect caused by traffic lights...

  14. Survey of Approaches to Generate Realistic Synthetic Graphs

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Seung-Hwan [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lee, Sangkeun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Powers, Sarah S [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shankar, Mallikarjun [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Imam, Neena [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    A graph is a flexible data structure that can represent relationships between entities. As with other data analysis tasks, the use of realistic graphs is critical to obtaining valid research results. Unfortunately, using the actual ("real-world") graphs for research and new algorithm development is difficult due to the presence of sensitive information in the data or due to the scale of data. This results in practitioners developing algorithms and systems that employ synthetic graphs instead of real-world graphs. Generating realistic synthetic graphs that provide reliable statistical confidence to algorithmic analysis and system evaluation involves addressing technical hurdles in a broad set of areas. This report surveys the state of the art in approaches to generate realistic graphs that are derived from fitted graph models on real-world graphs.

  15. The Characteristics and Realistic Enlightenment of Doctor-patient Relationship Based on the Treatment Effect in the Ming Dynasty%基于明代诊疗效果的医患关系特点及其现实启示∗

    Institute of Scientific and Technical Information of China (English)

    张俊义

    2016-01-01

    首先对明代民间医疗的功德观念作了简单介绍;其次对医者虽治而无功作了介绍并分析了原因;最后讨论了基于明代诊疗效果的医患关系特点对现实社会医患关系的启示:行业有门槛,通识应无界;责任已扩大,功绩要厘清;权利在提升,行使须依法;规则很重要,事后也监督。%At the beginning, this paper introduced the concept of merit in folk medicine simply. Secondly, the situation that although the healer cure but with no contribution is introduced to analyze the reason. Finally, it discussed the characteristics of the doctor-patient relationship based on treatment effect of Ming dynasty and realis-tic enlightenment to current doctor-patient relationship:the industry has threshold, general knowledge should be unbounded;the responsibility has expanded, merit must be clarify;rights are in the ascent, exercising right should be in accordance with the laws;the rules are very important, later supervision is also needed.

  16. 2 types of spicules "observed" in 3D realistic models

    CERN Document Server

    Martínez-Sykora, Juan

    2010-01-01

    Realistic numerical 3D models of the outer solar atmosphere show two different kind of spicule-like phenomena, as also observed on the solar limb. The numerical models are calculated using the 2 types of spicules "observed" in 3D realistic models Oslo Staggered Code (OSC) to solve the full MHD equations with non-grey and NLTE radiative transfer and thermal conduction along the magnetic field lines. The two types of spicules arise as a natural result of the dynamical evolution in the models. We discuss the different properties of these two types of spicules, their differences from observed spicules and what needs to be improved in the models.

  17. Putting a Realistic Theory of Mind into Agency Theory

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Stea, Diego

    2014-01-01

    concerning other such content. More realistically, individuals have some limited access to the minds of others. We explore the implications for classical agency theory of realistic assumptions regarding the human potential for interpersonal sensemaking. We discuss implications for the design and management......Agency theory is one of the most important foundational theories in management research, but it rests on contestable cognitive assumptions. Specifically, the principal is assumed to hold a perfect (correct) theory regarding some of the content of the agent's mind, while he is entirely ignorant...... of rewards, and trace implications for value creation in principal-agent relations....

  18. A generalized pyramid matching kernel for human action recognition in realistic videos.

    Science.gov (United States)

    Zhu, Jun; Zhou, Quan; Zou, Weijia; Zhang, Rui; Zhang, Wenjun

    2013-10-24

    Human action recognition is an increasingly important research topic in the fields of video sensing, analysis and understanding. Caused by unconstrained sensing conditions, there exist large intra-class variations and inter-class ambiguities in realistic videos, which hinder the improvement of recognition performance for recent vision-based action recognition systems. In this paper, we propose a generalized pyramid matching kernel (GPMK) for recognizing human actions in realistic videos, based on a multi-channel "bag of words" representation constructed from local spatial-temporal features of video clips. As an extension to the spatial-temporal pyramid matching (STPM) kernel, the GPMK leverages heterogeneous visual cues in multiple feature descriptor types and spatial-temporal grid granularity levels, to build a valid similarity metric between two video clips for kernel-based classification. Instead of the predefined and fixed weights used in STPM, we present a simple, yet effective, method to compute adaptive channel weights of GPMK based on the kernel target alignment from training data. It incorporates prior knowledge and the data-driven information of different channels in a principled way. The experimental results on three challenging video datasets (i.e., Hollywood2, Youtube and HMDB51) validate the superiority of our GPMK w.r.t. the traditional STPM kernel for realistic human action recognition and outperform the state-of-the-art results in the literature.

  19. Acoustic simulation in realistic 3D virtual scenes

    Science.gov (United States)

    Gozard, Patrick; Le Goff, Alain; Naz, Pierre; Cathala, Thierry; Latger, Jean

    2003-09-01

    The simulation workshop CHORALE developed in collaboration with OKTAL SE company for the French MoD is used by government services and industrial companies for weapon system validation and qualification trials in the infrared domain. The main operational reference for CHORALE is the assessment of the infrared guidance system of the Storm Shadow missile French version, called Scalp. The use of CHORALE workshop is now extended to the acoustic domain. The main objective is the simulation of the detection of moving vehicles in realistic 3D virtual scenes. This article briefly describes the acoustic model in CHORALE. The 3D scene is described by a set of polygons. Each polygon is characterized by its acoustic resistivity or its complex impedance. Sound sources are associated with moving vehicles and are characterized by their spectra and directivities. A microphone sensor is defined by its position, its frequency band and its sensitivity. The purpose of the acoustic simulation is to calculate the incoming acoustic pressure on microphone sensors. CHORALE is based on a generic ray tracing kernel. This kernel possesses original capabilities: computation time is nearly independent on the scene complexity, especially the number of polygons, databases are enhanced with precise physical data, special mechanisms of antialiasing have been developed that enable to manage very accurate details. The ray tracer takes into account the wave geometrical divergence and the atmospheric transmission. The sound wave refraction is simulated and rays cast in the 3D scene are curved according to air temperature gradient. Finally, sound diffraction by edges (hill, wall,...) is also taken into account.

  20. Boundary conditions towards realistic simulation of jet engine noise

    Science.gov (United States)

    Dhamankar, Nitin S.

    Strict noise regulations at major airports and increasing environmental concerns have made prediction and attenuation of jet noise an active research topic. Large eddy simulation coupled with computational aeroacoustics has the potential to be a significant research tool for this problem. With the emergence of petascale computer clusters, it is now computationally feasible to include the nozzle geometry in jet noise simulations. In high Reynolds number experiments on jet noise, the turbulent boundary layer on the inner surface of the nozzle separates into a turbulent free shear layer. Inclusion of a nozzle with turbulent inlet conditions is necessary to simulate this phenomenon realistically. This will allow a reasonable comparison of numerically computed noise levels with the experimental results. Two viscous wall boundary conditions are implemented for modeling the nozzle walls. A characteristic-based approach is compared with a computationally cheaper, extrapolation-based formulation. In viscous flow over a circular cylinder under two different regimes, excellent agreement is observed between the results of the two approaches. The results agree reasonably well with reference experimental and numerical results. Both the boundary conditions are thus found to be appropriate, the extrapolation-based formulation having an edge with its low cost. This is followed with the crucial step of generation of a turbulent boundary layer inside the nozzle. A digital filter-based turbulent inflow condition, extended in a new way to non-uniform curvilinear grids is implemented to achieve this. A zero pressure gradient flat plate turbulent boundary layer is simulated at a high Reynolds number to show that the method is capable of producing sustained turbulence. The length of the adjustment region necessary for synthetic inlet turbulence to recover from modeling errors is estimated. A low Reynolds number jet simulation including a round nozzle geometry is performed and the method

  1. Comparison of Sigma-Point and Extended Kalman Filters on a Realistic Orbit Determination Scenario

    Science.gov (United States)

    Gaebler, John; Hur-Diaz. Sun; Carpenter, Russell

    2010-01-01

    Sigma-point filters have received a lot of attention in recent years as a better alternative to extended Kalman filters for highly nonlinear problems. In this paper, we compare the performance of the additive divided difference sigma-point filter to the extended Kalman filter when applied to orbit determination of a realistic operational scenario based on the Interstellar Boundary Explorer mission. For the scenario studied, both filters provided equivalent results. The performance of each is discussed in detail.

  2. Sensor and actuator modeling of a realistic wheeled mobile robot simulator

    OpenAIRE

    José Gonçalves; José Lima; Hélder Filipe Pinto de Oliveira; Paulo José Cerqueira Gomes da Costa

    2008-01-01

    This paper describes the sensor and actuator modelingof a realistic wheeled mobile robot simulator. The motivationof developing such simulator is to produce a personalizedversatile tool that allows production and validationof robot software reducing considerably the developmenttime. The mobile robot simulator was developed in ObjectPascal with its dynamics based on the ODE (OpenDynamics Engine), allowing to develop robot software fora three wheel omnidirectional robot equipped with Infra-Red ...

  3. Using a Realist Research Methodology in Policy Analysis

    Science.gov (United States)

    Lourie, Megan; Rata, Elizabeth

    2017-01-01

    The article describes the usefulness of a realist methodology in linking sociological theory to empirically obtained data through the development of a methodological device. Three layers of analysis were integrated: 1. the findings from a case study about Maori language education in New Zealand; 2. the identification and analysis of contradictions…

  4. Evaluation of Highly Realistic Training for Independent Duty Corpsmen Students

    Science.gov (United States)

    2015-05-21

    such as resilience. IDC Highly Realistic Training 10 REFERENCES Bandura , A (1977). Self-efficacy: Toward a unifying theory of behavioral...that he or she can perform desired actions or behaviors ( Bandura , 1977). In the present study, three types of self-efficacy were assessed: general

  5. Using Concrete and Realistic Data in Evaluating Initial Visualization Designs

    DEFF Research Database (Denmark)

    Knudsen, Søren; Pedersen, Jeppe Gerner; Herdal, Thor

    2016-01-01

    We explore means of designing and evaluating initial visualization ideas, with concrete and realistic data in cases where data is not readily available. Our approach is useful in exploring new domains and avenues for visualization, and contrasts other visualization work, which typically operate u...

  6. A Sense of Responsibility in Realistic Children's Fiction.

    Science.gov (United States)

    Rochelle, Warren

    1991-01-01

    Discusses the qualities of successful realistic children's fiction and examines issues involved in writing and publishing for children. A historical overview of the image of children in fiction is presented; dealing with sensitive, emotional topics is discussed; and concerns of editors and publishers of children's fiction are addressed. (12…

  7. Realistic Fiction and the Social Studies. Children's Literature.

    Science.gov (United States)

    Mitchell-Powell, Brenda, Ed.

    1995-01-01

    Asserts that children's literature is an effective tool to access and present sophisticated social studies concepts in the elementary classroom. Maintains that realistic fiction can integrate the social sciences with philosophy and religion. Presents a bibliographic essay including children's books and teacher resources. (CFR)

  8. Creating a Realistic Context for Team Projects in HCI

    NARCIS (Netherlands)

    Koppelman, H.; Dijk, van E.M.A.G.

    2006-01-01

    Team projects are nowadays common practice in HCI education. This paper focuses on the role of clients and users in team projects in introductory HCI courses. In order to provide projects with a realistic context we invite people from industry to serve as clients for the student teams. Some of them

  9. "Shut My Mouth Wide Open": Realistic Fiction and Social Action.

    Science.gov (United States)

    Tyson, Cynthia A.

    1999-01-01

    Shares the responses of seven urban, male, African-American fifth graders to contemporary realistic fiction, discussing how the tying of this literature to the events in the boys' lives had the potential to move them toward social action. The paper examines the following: literature as a catalyst, reader responses to texts, critical literacy, and…

  10. The Potential and Challenges of Critical Realist Ethnography

    Science.gov (United States)

    Barron, Ian

    2013-01-01

    This article revisits the critical realist ethnographic process that was adopted in my doctoral thesis, which was concerned with the experiences of ethnic identity of white British and Pakistani British children as they started kindergarten in the northwest of England. The article focuses on the ethnography that emerged from the visits that I…

  11. Foreword: In situ gas surface interactions: approaching realistic conditions

    Science.gov (United States)

    Lundgren, Edvin; Over, Herbert

    2008-03-01

    This special issue is devoted to the application of in situ surface-sensitive techniques in the elucidation of catalysed reactions at (model) catalyst surfaces. Both reaction intermediates and the nature of the catalytically active phase are the targets of these investigations. In situ surface science techniques are also used to study the interaction of water with surfaces under realistic conditions. Since 80% of all technical chemicals are manufactured by utilizing (heterogeneous) catalysis, scientific understanding and technological development of catalysis are of central practical importance in modern society [1]. Heterogeneously catalysed reactions take place at the gas/solid interface. Therefore one of the major topics in surface chemistry and physics is closely related to heterogeneous catalysis, with the aim of developing novel catalysts and to improve catalysts' performances on the basis of atomic scale based knowledge. Despite the economical and environmental rewards—if such a goal is achieved—and despite 40 years of intensive research, practical catalysis is still safely in a black box: the reactivity and selectivity of a catalyst are commercially still optimized on a trial and error basis, applying the high throughput screening approach. The reason for this discrepancy between ambition and reality lies in the inherent complexity of the catalytic system, consisting of the working catalyst and the interaction of the catalyst with the reactant mixture. Practical (solid) catalysts consist of metal or oxide nanoparticles which are dispersed and stabilized on a support and which may be promoted by means of additives. These particles catalyse a reaction in pressures as high as 100 bar. Practical catalysis is in general considered to be far too complex for gaining atomic-scale understanding of the mechanism of the catalysed reaction of an industrial catalyst during its operation. Therefore it has been necessary to introduce idealization and simplification of

  12. Rehand: Realistic electric prosthetic hand created with a 3D printer.

    Science.gov (United States)

    Yoshikawa, Masahiro; Sato, Ryo; Higashihara, Takanori; Ogasawara, Tsukasa; Kawashima, Noritaka

    2015-01-01

    Myoelectric prosthetic hands provide an appearance with five fingers and a grasping function to forearm amputees. However, they have problems in weight, appearance, and cost. This paper reports on the Rehand, a realistic electric prosthetic hand created with a 3D printer. It provides a realistic appearance that is same as the cosmetic prosthetic hand and a grasping function. A simple link mechanism with one linear actuator for grasping and 3D printed parts achieve low cost, light weight, and ease of maintenance. An operating system based on a distance sensor provides a natural operability equivalent to the myoelectric control system. A supporter socket allows them to wear the prosthetic hand easily. An evaluation using the Southampton Hand Assessment Procedure (SHAP) demonstrated that an amputee was able to operate various objects and do everyday activities with the Rehand.

  13. A realistic polarizing Sagnac topology with DC readout for the Einstein Telescope

    CERN Document Server

    Wang, Mengyao; Brown, Daniel; Brueckner, Frank; Carbone, Ludovico; Palmer, Rebecca; Freise, Andreas

    2013-01-01

    The Einstein Telescope (ET) is a proposed future gravitational wave detector. Its design is original, using a triangular orientation of three detectors and a xylophone configuration, splitting each detector into one high-frequency and one low-frequency system. In other aspects the current design retains the dual-recycled Michelson interferometer typical of current detectors, such as Advanced LIGO. In this paper, we investigate the feasibility of replacing the low-frequency part of the ET detectors with a Sagnac interferometer. We show that a Sagnac interferometer, using realistic optical parameters based on the ET design, could provide a similar level of radiation pressure noise suppression without the need for a signal recycling mirror and the extensive filter cavities. We consider the practical issues of a realistic, power-recycled Sagnac, using linear arm cavities and polarizing optics. In particular we investigate the effects of non-perfect polarizing optics and propose a new method for the generation of ...

  14. Whole-volume integrated gyrokinetic simulation of plasma turbulence in realistic diverted-tokamak geometry

    Energy Technology Data Exchange (ETDEWEB)

    Chang, C S; Ku, S; Greengard, L; Park, G [Courant Institute of Mathematical Sciences, New York University, NY 10012 (United States); Diamond, P; Dif-Pradalier, G [University of California at San Diego, La Jolla, CA 92093 (United States); Adams, M; Keyes, D [Columbia University, New York, NY 10027 (United States); Barreto, R; D' Azevedo, E; Klasky, S; Podhorszki, N [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Chen, Y; Parker, S [University of Colorado at Boulder, Boulder, CO 80309 (United States); Cummings, J [California Institute of Technology, Pasadena, CA 91125 (United States); Ethier, S; Hahm, T S [Princeton Plasma Physics Laboratory, Princeton, NJ 08543 (United States); Hinton, F [Hinton Associates, Escondido, CA 92029 (United States); Lin, Z [University of California at Irvine, Irvine, CA 92697 (United States); Lofstead, J, E-mail: cschang@cims.nyu.ed [Georgia Institute of Technology, Atlanta, GA 30332 (United States)

    2009-07-01

    Performance prediction for ITER is based upon the ubiquitous experimental observation that the plasma energy confinement in the device core is strongly coupled to the edge confinement for an unknown reason. The coupling time-scale is much shorter than the plasma transport time-scale. In order to understand this critical observation, a multi-scale turbulence-neoclassical simulation of integrated edge-core plasma in a realistic diverted geometry is a necessity, but has been a formidable task. Thanks to the recent development in high performance computing, we have succeeded in the integrated multiscale gyrokinetic simulation of the ion-temperature-gradient driven turbulence in realistic diverted tokamak geometry for the first time. It is found that modification of the self-organized criticality in the core plasma by nonlocal core-edge coupling of ITG turbulence can be responsible for the core-edge confinement coupling.

  15. Milky Way Mass and Potential Recovery Using Tidal Streams in a Realistic Halo

    CERN Document Server

    Bonaca, Ana; Kuepper, Andreas H W; Diemand, Juerg; Johnston, Kathryn V; Hogg, David W

    2014-01-01

    We present a new method for determining the Galactic gravitational potential based on forward modeling of tidal stellar streams. We use this method to test the performance of smooth and static analytic potentials in representing realistic dark matter halos, which have substructure and are continually evolving by accretion. Our FAST-FORWARD method uses a Markov Chain Monte Carlo algorithm to compare, in 6D phase space, an "observed" stream to models created in trial analytic potentials. We analyze a large sample of streams evolved in the Via Lactea II (VL2) simulation, which represents a realistic Galactic halo potential. The recovered potential parameters are in agreement with the best fit to the global, present-day VL2 potential. However, merely assuming an analytic potential limits the dark matter halo mass measurement to an accuracy of 5 to 20%, depending on the choice of analytic parametrization. Collectively, mass estimates using streams from our sample reach this fundamental limit, but individually they...

  16. Transport properties in a monolayer graphene modulated by the realistic magnetic field and the Schottky metal stripe

    Science.gov (United States)

    Lu, Jian-Duo; Li, Yun-Bao; Liu, Hong-Yu; Peng, Shun-Jin; Zhao, Fei-Xiang

    2016-09-01

    Based on the transfer-matrix method, a systematic investigation of electron transport properties is done in a monolayer graphene modulated by the realistic magnetic field and the Schottky metal stripe. The strong dependence of the electron transmission and the conductance on the incident angle of carriers is clearly seen. The height, position as well as width of the barrier also play an important role on the electron transport properties. These interesting results are very useful for understanding the tunneling mechanism in the monolayer graphene and helpful for designing the graphene-based electrical device modulated by the realistic magnetic field and the electrical barrier.

  17. Optimizing Wind And Hydropower Generation Within Realistic Reservoir Operating Policy

    Science.gov (United States)

    Magee, T. M.; Clement, M. A.; Zagona, E. A.

    2012-12-01

    Previous studies have evaluated the benefits of utilizing the flexibility of hydropower systems to balance the variability and uncertainty of wind generation. However, previous hydropower and wind coordination studies have simplified non-power constraints on reservoir systems. For example, some studies have only included hydropower constraints on minimum and maximum storage volumes and minimum and maximum plant discharges. The methodology presented here utilizes the pre-emptive linear goal programming optimization solver in RiverWare to model hydropower operations with a set of prioritized policy constraints and objectives based on realistic policies that govern the operation of actual hydropower systems, including licensing constraints, environmental constraints, water management and power objectives. This approach accounts for the fact that not all policy constraints are of equal importance. For example target environmental flow levels may not be satisfied if it would require violating license minimum or maximum storages (pool elevations), but environmental flow constraints will be satisfied before optimizing power generation. Additionally, this work not only models the economic value of energy from the combined hydropower and wind system, it also captures the economic value of ancillary services provided by the hydropower resources. It is recognized that the increased variability and uncertainty inherent with increased wind penetration levels requires an increase in ancillary services. In regions with liberalized markets for ancillary services, a significant portion of hydropower revenue can result from providing ancillary services. Thus, ancillary services should be accounted for when determining the total value of a hydropower system integrated with wind generation. This research shows that the end value of integrated hydropower and wind generation is dependent on a number of factors that can vary by location. Wind factors include wind penetration level

  18. Creating photo-realistic works in a 3D scene using layers styles to create an animation

    Science.gov (United States)

    Avramescu, A. M.

    2015-11-01

    Creating realist objects in a 3D scene is not an easy work. We have to be very careful to make the creation very detailed. If we don't know how to make these photo-realistic works, by using the techniques and a good reference photo we can create an amazing amount of detail and realism. For example, in this article there are some of these detailed methods from which we can learn the techniques necessary to make beautiful and realistic objects in a scene. More precisely, in this paper, we present how to create a 3D animated scene, mainly using the Pen Tool and Blending Options. Indeed, this work is based on teaching some simple ways of using the Layer Styles to create some great shadows, lights, textures and a realistic sense of 3 Dimension. The present work involves also showing how some interesting ways of using the illuminating and rendering options can create a realistic effect in a scene. Moreover, this article shows how to create photo realistic 3D models from a digital image. The present work proposes to present how to use Illustrator paths, texturing, basic lighting and rendering, how to apply textures and how to parent the building and objects components. We also propose to use this proposition to recreate smaller details or 3D objects from a 2D image. After a critic art stage, we are able now to present in this paper the architecture of a design method that proposes to create an animation. The aim is to create a conceptual and methodological tutorial to address this issue both scientifically and in practice. This objective also includes proposing, on strong scientific basis, a model that gives the possibility of a better understanding of the techniques necessary to create a realistic animation.

  19. Modeling of biofuel pellets torrefaction in a realistic geometry

    Directory of Open Access Journals (Sweden)

    Artiukhina Ekaterina

    2016-01-01

    Full Text Available Low temperature pyrolysis also known as torrefaction is considered as a promising pretreatment technology for conversion of biomass into a solid biofuel with enhanced properties in terms of lower moisture and volatile matter content, hydrophobicity and increased heating value. A thermal treatment leads to a non-uniform temperature field and chemical reactions proceeding unevenly within the pellets. However the temperature is assumed to be uniform in the pellets in the majority of models. Here we report on the model of single pellet biomass torrefaction, taking into account the heat transfer and chemical kinetics in the realistic geometry. The evolution of temperature and material density in the non-stationary thermo-chemical process is described by the system of non-linear partial differential equations. The model describing the high-temperature drying of biomass pellet was also introduced. The importance of boundary effects in realistic simulations of biomass pellets torrefaction is underlined in this work.

  20. A general realistic treatment of the disk paradox

    CERN Document Server

    Pantazis, George

    2016-01-01

    Mechanical angular momentum is not conserved in systems involving electromagnetic fields with non-zero electromagnetic field angular momentum. Conservation is restored only if the total (mechanical and field) angular momentum is considered. Previous studies have investigated this effect, known as "Feynman's Electromagnetic Paradox" or simply "Disk Paradox" in the context of idealized systems (infinite or infinitesimal solenoids and charged cylinders \\etc). In the present analysis we generalize previous studies by considering more realistic systems with finite components and demonstrating explicitly the conservation of the total angular momentum. This is achieved by expressing both the mechanical and the field angular momentum in terms of charges and magnetic field fluxes through various system components. Using this general expression we demonstrate explicitly the conservation of total angular momentum in both idealized and realistic systems (finite solenoid concentric with two charged long cylinders) taking ...

  1. Bell's inequalities with realistic noise for polarization-entangled photons

    CERN Document Server

    Cabello, A; Lamas-Linares, A; Cabello, Adan; Feito, Alvaro; Lamas-Linares, Antia

    2005-01-01

    Contrary to the usual assumption that the experimental preparation of pure entangled states can be described by mixed states due to white noise, a more realistic description for polarization-entangled states produced by parametric down-conversion is that they are mixed states due to decoherence in a preferred polarization basis. This distinction between white and colored noise is crucial when we look for maximal violations of Bell's inequalities for two-qubit and two-qutrit entangled states. We find that violations of Bell's inequalities with realistic noise for polarization-entangled photons are extremely robust for colored noise, whereas this is not the case for white noise. In addition, we study the difference between white and colored noise for maximal violations of Bell's inequalities for three and four-qubit entangled states.

  2. Towards a Realistic Parsing of the Feynman Path Integral

    Directory of Open Access Journals (Sweden)

    Ken Wharton

    2016-01-01

    Full Text Available The Feynman path integral does not allow a one real path interpretation, because the quantum amplitudes contribute to probabilities in a non-separable manner. The opposite extreme, all paths happen, is not a useful or informative account. In this paper it is shown that an intermediate parsing of the path integral, into realistic non-interfering possibilities, is always available. Each realistic possibility formally corresponds to numerous particle paths, but is arguably best interpreted as a spacetime-valued field. Notably, one actual field history can always be said to occur, although it will generally not have an extremized action. The most obvious concerns with this approach are addressed, indicating necessary follow-up research. But without obvious showstoppers, it seems plausible that the path integral might be reinterpreted to explain quantum phenomena in terms of Lorentz covariant field histories.Quanta 2016; 5: 1–11.

  3. Role-playing for more realistic technical skills training.

    Science.gov (United States)

    Nikendei, C; Zeuch, A; Dieckmann, P; Roth, C; Schäfer, S; Völkl, M; Schellberg, D; Herzog, W; Jünger, J

    2005-03-01

    Clinical skills are an important and necessary part of clinical competence. Simulation plays an important role in many fields of medical education. Although role-playing is common in communication training, there are no reports about the use of student role-plays in the training of technical clinical skills. This article describes an educational intervention with analysis of pre- and post-intervention self-selected student survey evaluations. After one term of skills training, a thorough evaluation showed that the skills-lab training did not seem very realistic nor was it very demanding for trainees. To create a more realistic training situation and to enhance students' involvement, case studies and role-plays with defined roles for students (i.e. intern, senior consultant) were introduced into half of the sessions. Results of the evaluation in the second term showed that sessions with role-playing were rated significantly higher than sessions without role-playing.

  4. An Argument Against the Realistic Interpretation of the Wave Function

    Science.gov (United States)

    Rovelli, Carlo

    2016-10-01

    Testable predictions of quantum mechanics are invariant under time reversal. But the evolution of the quantum state in time is not so, neither in the collapse nor in the no-collapse interpretations of the theory. This is a fact that challenges any realistic interpretation of the quantum state. On the other hand, this fact raises no difficulty if we interpret the quantum state as a mere calculation device, bookkeeping past real quantum events.

  5. Extending AI Planning to Solve more Realistic Problems

    OpenAIRE

    Zalaket, Joseph

    2008-01-01

    In this chapter, we have presented multiple extensions for classical planning algorithms in order to allow them to solve more realistic problems. This kind of problems can contain any type of knowledge and can require complex handling which is not yet supported by the existing planning algorithms. Some complicated problems can be expressed with the recent extensions to PDDL language, but the main lack remains especially because of the incapacity of the current planners. We have suggested and ...

  6. Highly Realistic, Immersive Training for Navy Corpsmen: Preliminary Results

    Science.gov (United States)

    2014-12-01

    the actors who play the role of casualties are actual amputees , some of whom were injured in combat. The scenarios require that corpsmen demonstrate...black (9%), Hispanic (5%), and other race groups. A quarter of respon- dents (25%) marked “mixed or multiple races.” Measures To evaluate satisfaction...feel realistic Participants’ Suggestions for Improving the Training Give more scenarios and more time at MOUT Do the training multiple times, so that

  7. Music therapy for palliative care: A realist review.

    OpenAIRE

    McConnell, T; Porter, Samuel

    2016-01-01

    OBJECTIVE: Music therapy has experienced a rising demand as an adjunct therapy for symptom management among palliative care patients. We conducted a realist review of the literature to develop a greater understanding of how music therapy might benefit palliative care patients and the contextual mechanisms that promote or inhibit its successful implementation. METHOD: We searched electronic databases (CINAHL, Embase, Medline, and PsychINFO) for literature containing information on music therap...

  8. Precision robotic control of agricultural vehicles on realistic farm trajectories

    Science.gov (United States)

    Bell, Thomas

    High-precision "autofarming", or precise agricultural vehicle guidance, is rapidly becoming a reality thanks to increasing computing power and carrier-phase differential GPS ("CPDGPS") position and attitude sensors. Realistic farm trajectories will include not only rows but also arcs created by smoothly joining rows or path-planning algorithms, spirals for farming center-pivot irrigated fields, and curved trajectories dictated by nonlinear field boundaries. In addition, fields are often sloped, and accurate control may be required either on linear trajectories or on curved contours. A three-dimensional vehicle model which adapts to changing vehicle and ground conditions was created, and a low-order model for controller synthesis was extracted based on nominal conditions. The model was extended to include a towed implement. Experimentation showed that an extended Kalman filter could identify the vehicle's state in real-time. An approximation was derived for the additional positional uncertainty introduced by the noisy "lever-arm correction" necessary to translate the GPS position measurement at the roof antenna to the vehicle's control point on the ground; this approximation was then used to support the assertion that attitude measurement accuracy was as important to control point position measurement as the original position measurement accuracy at the GPS antenna. The low-order vehicle control model was transformed to polar coordinates for control on arcs and spirals. Experimental data showed that the tractor's control, point tracked an arc to within a -0.3 cm mean and a 3.4 cm standard deviation and a spiral to within a -0.2 cm mean and a 5.3 cm standard deviation. Cubic splines were used to describe curve trajectories, and a general expression for the time-rate-of-change of curve-related parameters was derived. Four vehicle control algorithms were derived for curve tracking: linear local-error control based on linearizing the vehicle about the curve's radius of

  9. Fast Rendering of Realistic Virtual Character in Game Scene

    Directory of Open Access Journals (Sweden)

    Mengzhao Yang

    2013-07-01

    Full Text Available Human skin is made up of multiple translucent layers and rendering of skin appearance usually acquire complex modeling and massive calculation. In some practical applications such as 3D game development, we not only approximate the realistic looking skin but also develop efficient method to implement easily for meeting needs of real-time rendering. In this study, we solve the problem of wrap lighting and introduce a surface details approximation method to give realistic rendering of virtual character. Our method considers that different thicknesses of geometry on the skin surface can result in different scattering degree of incident light and so pre-calculate the diffuse falloff into a look-up texture. Also, we notice that scattering is strongly color dependent and small bumps are common on the skin surface and so pre-soften the finer details on the skin surface according to the R/G/B channel. At last, we linearly interpolate the diffuse lighting with different scattering degree from the look-up texture sampled with the curvature and NdotL. Experiment results show that the proposed approach yields realistic virtual character and obtains high frames per second in real-time rendering.

  10. Towards Performance Evaluation of Cognitive Radio Network in Realistic Environment

    Directory of Open Access Journals (Sweden)

    Vivek Kukreja

    2013-11-01

    Full Text Available The scarcity of free spectrum compels us to look for alternatives for ever increasing wireless applications. Cognitive Radios (CR is one such alternative that can solve this problem. The network nodes having CR capability is termed as Cognitive Radio Network (CRN. To have communication in CRN a routing protocol is required. The primary goal of which is to provide a route from source to destination. Various routing protocols have been proposed and tested in idealistic environment using simulation software such as NS-2 and QualNet. This paper is an effort in the same direction but the efficacy is evaluated in realistic conditions by designing a simulator in MATLAB-7. To make the network scenario realistic obstacles of different shapes, type, sizes and numbers have been introduced. In addition to that the shape of the periphery is also varied to find the impact of it on routing protocols. From the results it is observed that the outcomes in the realistic and idealistic vary significantly. The reason for the same has also been discussed in this paper.

  11. Protocol: realist synthesis of the impact of unemployment insurance policies on poverty and health.

    Science.gov (United States)

    Molnar, Agnes; O'Campo, Patricia; Ng, Edwin; Mitchell, Christiane; Muntaner, Carles; Renahy, Emilie; St John, Alexander; Shankardass, Ketan

    2015-02-01

    Unemployment insurance is an important social protection policy that buffers unemployed workers against poverty and poor health. Most unemployment insurance studies focus on whether increases in unemployment insurance generosity are predictive of poverty and health outcomes. Less work has used theory-driven approaches to understand and explain how and why unemployment insurance works, for whom, and under what circumstances. Given this, we present a realist synthesis protocol that seeks to unpack how contextual influences trigger relevant mechanisms to generate poverty and health outcomes. In this protocol, we conceptualize unemployment insurance as a key social protection policy; provide a supporting rationale on the need for a realist synthesis; and describe our process on identifying context-mechanism-outcome pattern configurations. Six methodological steps are described: initial theory development, search strategy; selection and appraisal of documents; data extraction; analysis and synthesis process; and presentation and dissemination of revised theory. Our forthcoming realist synthesis will be the first to build and test theory on the intended and unintended outcomes of unemployment insurance policies. Anticipated findings will allow policymakers to move beyond 'black box' approaches to consider 'mechanism-based' explanations that explicate the logic on how and why unemployment insurance matters.

  12. Protocol - realist and meta-narrative evidence synthesis: Evolving Standards (RAMESES

    Directory of Open Access Journals (Sweden)

    Westhorp Gill

    2011-08-01

    Full Text Available Abstract Background There is growing interest in theory-driven, qualitative and mixed-method approaches to systematic review as an alternative to (or to extend and supplement conventional Cochrane-style reviews. These approaches offer the potential to expand the knowledge base in policy-relevant areas - for example by explaining the success, failure or mixed fortunes of complex interventions. However, the quality of such reviews can be difficult to assess. This study aims to produce methodological guidance, publication standards and training resources for those seeking to use the realist and/or meta-narrative approach to systematic review. Methods/design We will: [a] collate and summarise existing literature on the principles of good practice in realist and meta-narrative systematic review; [b] consider the extent to which these principles have been followed by published and in-progress reviews, thereby identifying how rigour may be lost and how existing methods could be improved; [c] using an online Delphi method with an interdisciplinary panel of experts from academia and policy, produce a draft set of methodological steps and publication standards; [d] produce training materials with learning outcomes linked to these steps; [e] pilot these standards and training materials prospectively on real reviews-in-progress, capturing methodological and other challenges as they arise; [f] synthesise expert input, evidence review and real-time problem analysis into more definitive guidance and standards; [g] disseminate outputs to audiences in academia and policy. The outputs of the study will be threefold: 1. Quality standards and methodological guidance for realist and meta-narrative reviews for use by researchers, research sponsors, students and supervisors 2. A 'RAMESES' (Realist and Meta-review Evidence Synthesis: Evolving Standards statement (comparable to CONSORT or PRISMA of publication standards for such reviews, published in an open

  13. Can realistic nuclear interactions tolerate a resonant tetraneutron ?

    CERN Document Server

    Lazauskas, R

    2005-01-01

    The possible existence of four-neutron resonances close to the physical energy region is explored. Faddeev-Yakubovsky equations have been solved in configuration space using realistic nucleon-nucleon interaction models. Complex Scaling and Analytical Continuation in the Coupling Constant methods were used to follow the resonance pole trajectories, which emerge out of artificially bound tetraneutron states. The final pole positions for four-neutron states lie in the third energy quadrant with negative real energy parts and should thus not be physically observable.

  14. Recovering the quantum formalism from physically realist axioms.

    Science.gov (United States)

    Auffèves, Alexia; Grangier, Philippe

    2017-03-03

    We present a heuristic derivation of Born's rule and unitary transforms in Quantum Mechanics, from a simple set of axioms built upon a physical phenomenology of quantization. This approach naturally leads to the usual quantum formalism, within a new realistic conceptual framework that is discussed in details. Physically, the structure of Quantum Mechanics appears as a result of the interplay between the quantized number of "modalities" accessible to a quantum system, and the continuum of "contexts" that are required to define these modalities. Mathematically, the Hilbert space structure appears as a consequence of a specific "extra-contextuality" of modalities, closely related to the hypothesis of Gleason's theorem, and consistent with its conclusions.

  15. A continuous family of realistic Susy SU(5) GUTs

    Science.gov (United States)

    Bajc, Borut

    2016-06-01

    It is shown that the minimal renormalizable supersymmetric SU(5) is still realistic providing the supersymmetric scale is at least few tens of TeV or large R-parity violating terms are considered. In the first case the vacuum is metastable, and different consistency constraints can give a bounded allowed region in the tan β - msusy plane. In the second case the mass eigenstate electron (down quark) is a linear combination of the original electron (down quark) and Higgsino (heavy colour triplet), and the mass ratio of bino and wino is determined. Both limits lead to light gravitino dark matter.

  16. Mode-Coupling in Realistic Rotating Gravitational Collapse

    CERN Document Server

    Hod, S

    2000-01-01

    We analyze the mode-coupling phenomena in realistic rotating gravitational collapse. Physically, this phenomena is caused by the dragging of reference frames, due to the black-hole (or star's) rotation. It is shown that different modes become coupled during the rotating collapse. As a consequence, the asymptotic late-time tails are dominated by modes which, in general, have an angular distribution different from the original one. We show that a rotating Kerr black hole becomes ``bald'' slower than a spherically-symmetric Schwarzschild black hole. This paper considers gravitational, electromagnetic and neutrino fields propagating on a Kerr background.

  17. Dynamic Enhanced Inter-Cell Interference Coordination for Realistic Networks

    DEFF Research Database (Denmark)

    Pedersen, Klaus I.; Alvarez, Beatriz Soret; Barcos, Sonia;

    2016-01-01

    Enhanced Inter-Cell Interference Coordination (eICIC) is a key ingredient to boost the performance of co-channel Heterogeneous Networks (HetNets). eICIC encompasses two main techniques: Almost Blank Subframes (ABS), during which the macro cell remains silent to reduce the interference, and biased...... and an opportunistic approach exploiting the varying cell conditions. Moreover, an autonomous fast distributed muting algorithm is presented, which is simple, robust, and well suited for irregular network deployments. Performance results for realistic network deployments show that the traditional semi-static e...

  18. ROC Analysis and a Realistic Model of Heart Rate Variability

    CERN Document Server

    Thurner, S; Teich, M C; Thurner, Stefan; Feurstein, Markus C.; Teich, Malvin C.

    1998-01-01

    We have carried out a pilot study on a standard collection of electrocardiograms from patients who suffer from congestive heart failure, and subjects without cardiac pathology, using receiver-operating-characteristic (ROC) analysis. The scale-dependent wavelet-coefficient standard deviation superior to two commonly used measures of cardiac dysfunction when the two classes of patients cannot be completely separated. A jittered integrate-and-fire model with a fractal Gaussian-noise kernel provides a realistic simulation of heartbeat sequences for both heart-failure patients and normal subjects.

  19. Scaling up complex interventions: insights from a realist synthesis.

    Science.gov (United States)

    Willis, Cameron D; Riley, Barbara L; Stockton, Lisa; Abramowicz, Aneta; Zummach, Dana; Wong, Geoff; Robinson, Kerry L; Best, Allan

    2016-12-19

    Preventing chronic diseases, such as cancer, cardiovascular disease and diabetes, requires complex interventions, involving multi-component and multi-level efforts that are tailored to the contexts in which they are delivered. Despite an increasing number of complex interventions in public health, many fail to be 'scaled up'. This study aimed to increase understanding of how and under what conditions complex public health interventions may be scaled up to benefit more people and populations.A realist synthesis was conducted and discussed at an in-person workshop involving practitioners responsible for scaling up activities. Realist approaches view causality through the linkages between changes in contexts (C) that activate mechanisms (M), leading to specific outcomes (O) (CMO configurations). To focus this review, three cases of complex interventions that had been successfully scaled up were included: Vibrant Communities, Youth Build USA and Pathways to Education. A search strategy of published and grey literature related to each case was developed, involving searches of relevant databases and nominations from experts. Data extracted from included documents were classified according to CMO configurations within strategic themes. Findings were compared and contrasted with guidance from diffusion theory, and interpreted with knowledge users to identify practical implications and potential directions for future research.Four core mechanisms were identified, namely awareness, commitment, confidence and trust. These mechanisms were activated within two broad scaling up strategies, those of renewing and regenerating, and documenting success. Within each strategy, specific actions to change contexts included building partnerships, conducting evaluations, engaging political support and adapting funding models. These modified contexts triggered the identified mechanisms, leading to a range of scaling up outcomes, such as commitment of new communities, changes in relevant

  20. The KM phase in semi-realistic heterotic orbifold models

    Energy Technology Data Exchange (ETDEWEB)

    Giedt, Joel

    2000-07-05

    In string-inspired semi-realistic heterotic orbifolds models with an anomalous U(1){sub X},a nonzero Kobayashi-Masakawa (KM) phase is shown to arise generically from the expectation values of complex scalar fields, which appear in nonrenormalizable quark mass couplings. Modular covariant nonrenormalizable superpotential couplings are constructed. A toy Z{sub 3} orbifold model is analyzed in some detail. Modular symmetries and orbifold selection rules are taken into account and do not lead to a cancellation of the KM phase. We also discuss attempts to obtain the KM phase solely from renormalizable interactions.

  1. Study of Dynamic eICIC in a Realistic Urban Deployment

    DEFF Research Database (Denmark)

    Pedersen, Klaus I.; Soret, Beatriz; Barcos, Sonia;

    2015-01-01

    In this paper, we investigate the operation of eICIC in a realistic deployment based on site specific data from a dense urban European capital area. Rather than the classical semistatic and common network-wide configuration, the importance of having highly dynamic and distributed mechanisms...... deployments, whereas the set of proposed fast dynamic eICIC algorithms leads to capacity gains on the order of 35-120% depending on the local environment characteristics. In the analysis of the performance results for the site specific use case, it is furthermore highlighted how those deviate from typical...

  2. Didactic Contracts in Realistic Mathematics Education Teaching Practice in Indonesia: A lesson on addition

    DEFF Research Database (Denmark)

    Putra, Zetra Hainul

    This paper aims to investigate characterize features of didactic contracts in realistic mathematics education teaching practice in Indonesia in the case of a lesson on addition. We just focus on some episodes of 26 first grade students and a female teacher from SDN 197 Palembang learning...... combinations that make ten based on a Palembang traditional food, pempek, and tablets of medicine. The result shows that some features such as formulation and validation appear during the teaching and learning process. The students are able to produce combinations that make ten individually and collectively...

  3. Geometrical order-of-magnitude estimates for spatial curvature in realistic models of the Universe

    CERN Document Server

    Buchert, Thomas; van Elst, Henk; 10.1007/s10714-009-0828-4

    2009-01-01

    The thoughts expressed in this article are based on remarks made by J\\"urgen Ehlers at the Albert-Einstein-Institut, Golm, Germany in July 2007. The main objective of this article is to demonstrate, in terms of plausible order-of-magnitude estimates for geometrical scalars, the relevance of spatial curvature in realistic models of the Universe that describe the dynamics of structure formation since the epoch of matter-radiation decoupling. We introduce these estimates with a commentary on the use of a quasi-Newtonian metric form in this context.

  4. Semantic modeling for theory clarification: The realist vs liberal international relations perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bray, O.H. [Sandia National Labs., Albuquerque, NM (United States)]|[Univ. of New Mexico, Albuquerque, NM (United States). Political Science Dept.

    1994-04-01

    This paper describes a natural language based, semantic information modeling methodology and explores its use and value in clarifying and comparing political science theories and frameworks. As an example, the paper uses this methodology to clarify and compare some of the basic concepts and relationships in the realist (e.g. Waltz) and the liberal (e.g. Rosenau) paradigms for international relations. The methodology can provide three types of benefits: (1) it can clarify and make explicit exactly what is meant by a concept; (2) it can often identify unanticipated implications and consequence of concepts and relationships; and (3) it can help in identifying and operationalizing testable hypotheses.

  5. Electron percolation in realistic models of carbon nanotube networks

    Science.gov (United States)

    Simoneau, Louis-Philippe; Villeneuve, Jérémie; Rochefort, Alain

    2015-09-01

    The influence of penetrable and curved carbon nanotubes (CNT) on the charge percolation in three-dimensional disordered CNT networks have been studied with Monte-Carlo simulations. By considering carbon nanotubes as solid objects but where the overlap between their electron cloud can be controlled, we observed that the structural characteristics of networks containing lower aspect ratio CNT are highly sensitive to the degree of penetration between crossed nanotubes. Following our efficient strategy to displace CNT to different positions to create more realistic statistical models, we conclude that the connectivity between objects increases with the hard-core/soft-shell radii ratio. In contrast, the presence of curved CNT in the random networks leads to an increasing percolation threshold and to a decreasing electrical conductivity at saturation. The waviness of CNT decreases the effective distance between the nanotube extremities, hence reducing their connectivity and degrading their electrical properties. We present the results of our simulation in terms of thickness of the CNT network from which simple structural parameters such as the volume fraction or the carbon nanotube density can be accurately evaluated with our more realistic models.

  6. A general realistic treatment of the disk paradox

    Science.gov (United States)

    Pantazis, George; Perivolaropoulos, Leandros

    2017-01-01

    Mechanical angular momentum is not conserved in systems involving electromagnetic fields with non-zero electromagnetic field angular momentum. Conservation is restored only if the total (mechanical and field) angular momentum is considered. Previous studies have investigated this effect, known as ‘Feynman’s Electromagnetic Paradox’ or simply ‘Disk Paradox’ in the context of idealized systems (infinite or infinitesimal solenoids and charged cylinders etc). In the present analysis we generalize previous studies by considering more realistic systems with finite components and demonstrating explicitly the conservation of the total angular momentum. This is achieved by expressing both the mechanical and the field angular momentum in terms of charges and magnetic field fluxes through various system components. Using this general expression and the closure of magnetic field lines, we demonstrate explicitly the conservation of total angular momentum in both idealized and realistic systems (finite solenoid concentric with two charged cylinders, much longer than the solenoid) taking all the relevant terms into account including the flux outside of the solenoid. This formalism has the potential to facilitate a simpler and more accurate demonstration of total angular momentum conservation in undergraduate physics electromagnetism laboratories.

  7. Time variability of α from realistic models of Oklo reactors

    Science.gov (United States)

    Gould, C. R.; Sharapov, E. I.; Lamoreaux, S. K.

    2006-08-01

    We reanalyze Oklo Sm149 data using realistic models of the natural nuclear reactors. Disagreements among recent Oklo determinations of the time evolution of α, the electromagnetic fine structure constant, are shown to be due to different reactor models, which led to different neutron spectra used in the calculations. We use known Oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models. Two Oklo reactors, RZ2 and RZ10, were modeled with MCNP. The resulting neutron spectra were used to calculate the change in the Sm149 effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-meV resonance. We independently deduce ancient Sm149 effective cross sections and use these values to set limits on the time variation of α. Our study resolves a contradictory situation with previous Oklo α results. Our suggested 2σ bound on a possible time variation of α over 2 billion years is stringent: -0.11≤Δα/α≤0.24, in units of 10-7, but model dependent in that it assumes only α has varied over time.

  8. Towards Modeling Realistic Mobility for Performance Evaluations in MANET

    Science.gov (United States)

    Aravind, Alex; Tahir, Hassan

    Simulation modeling plays crucial role in conducting research on complex dynamic systems like mobile ad hoc networks and often the only way. Simulation has been successfully applied in MANET for more than two decades. In several recent studies, it is observed that the credibility of the simulation results in the field has decreased while the use of simulation has steadily increased. Part of this credibility crisis has been attributed to the simulation of mobility of the nodes in the system. Mobility has such a fundamental influence on the behavior and performance of mobile ad hoc networks. Accurate modeling and knowledge of mobility of the nodes in the system is not only helpful but also essential for the understanding and interpretation of the performance of the system under study. Several ideas, mostly in isolation, have been proposed in the literature to infuse realism in the mobility of nodes. In this paper, we attempt a holistic analysis of creating realistic mobility models and then demonstrate creation and analysis of realistic mobility models using a software tool we have developed. Using our software tool, desired mobility of the nodes in the system can be specified, generated, analyzed, and then the trace can be exported to be used in the performance studies of proposed algorithms or systems.

  9. Diffusive and dynamical radiating stars with realistic equations of state

    Science.gov (United States)

    Brassel, Byron P.; Maharaj, Sunil D.; Goswami, Rituparno

    2017-03-01

    We model the dynamics of a spherically symmetric radiating dynamical star with three spacetime regions. The local internal atmosphere is a two-component system consisting of standard pressure-free, null radiation and an additional string fluid with energy density and nonzero pressure obeying all physically realistic energy conditions. The middle region is purely radiative which matches to a third region which is the Schwarzschild exterior. A large family of solutions to the field equations are presented for various realistic equations of state. We demonstrate that it is possible to obtain solutions via a direct integration of the second order equations resulting from the assumption of an equation of state. A comparison of our solutions with earlier well known results is undertaken and we show that all these solutions, including those of Husain, are contained in our family. We then generalise our class of solutions to higher dimensions. Finally we consider the effects of diffusive transport and transparently derive the specific equations of state for which this diffusive behaviour is possible.

  10. Simulating realistic predator signatures in quantitative fatty acid signature analysis

    Science.gov (United States)

    Bromaghin, Jeffrey F.

    2015-01-01

    Diet estimation is an important field within quantitative ecology, providing critical insights into many aspects of ecology and community dynamics. Quantitative fatty acid signature analysis (QFASA) is a prominent method of diet estimation, particularly for marine mammal and bird species. Investigators using QFASA commonly use computer simulation to evaluate statistical characteristics of diet estimators for the populations they study. Similar computer simulations have been used to explore and compare the performance of different variations of the original QFASA diet estimator. In both cases, computer simulations involve bootstrap sampling prey signature data to construct pseudo-predator signatures with known properties. However, bootstrap sample sizes have been selected arbitrarily and pseudo-predator signatures therefore may not have realistic properties. I develop an algorithm to objectively establish bootstrap sample sizes that generates pseudo-predator signatures with realistic properties, thereby enhancing the utility of computer simulation for assessing QFASA estimator performance. The algorithm also appears to be computationally efficient, resulting in bootstrap sample sizes that are smaller than those commonly used. I illustrate the algorithm with an example using data from Chukchi Sea polar bears (Ursus maritimus) and their marine mammal prey. The concepts underlying the approach may have value in other areas of quantitative ecology in which bootstrap samples are post-processed prior to their use.

  11. Effects of instruction based on realistic mathematics education on mathematics achievement: A meta-analysis studyGerçekçi matematik eğitimi destekli öğretimin matematik başarısına etkisi: Bir meta-analiz çalışması

    Directory of Open Access Journals (Sweden)

    Abdullah Kaplan

    2015-07-01

    Full Text Available The purpose of this research is to determine the overall effect of instruction based on realistic mathematics education on mathematics achievement. The Meta-Analysis method recently increased in popularity in the field of educational science is used to accomplish this goal. Some criterions have been put in the determination of the study included in the survey and 12 national thesis in accordance with these criterions constituted the sample of this study. Process effectiveness method of meta-analysis is used in the analysis of data and Hedges’s g is used in the calculation of effect size of the study. At the end of the study, realistic mathematics education has an overall, positive and moderate effect on the mathematics achievement (Q = 16.406; p = 0.127. Howewer, the distribution of the effect sizes of the studies included in the survey are found to be homogeneous. At the end of the Z test carried out for the purpose of statistical significance, the value of effect size is observed statistically significant (Z = 7.966; p <0.05. The number of error protection is calculated 91 study to determine the publication bias of the study according to Orwin’s method. According to Orwin’s Fail Safe-N, the research could not have publication bias.   Özet Bu araştırmanın amacı gerçekçi matematik eğitiminin matematik başarısı üzerindeki genel etkisini belirlemektir. Bu amacı gerçekleştirmek için eğitim bilimleri alanında yakın zamanda popülerliği artan meta-analiz yöntemi kullanılmıştır. Araştırmaya dâhil edilecek çalışmaların belirlenmesinde bazı kriterler belirlenmiş ve bu kriterlere uygun olan 12 ulusal tez bu araştırmanın örneklemini oluşturmuştur. Verilerin analizinde işlem etkililiği meta analizi yöntemi kullanılmış olup araştırmaların etki büyüklüklerinin hesaplanmasında Hedges’s g kullanılmıştır. Araştırma sonucunda gerçekçi matematik eğitiminin matematik başarısı üzerinde genel

  12. The work is never ending: uncovering teamwork sustainability using realistic evaluation.

    Science.gov (United States)

    Frykman, Mandus; von Thiele Schwarz, Ulrica; Muntlin Athlin, Åsa; Hasson, Henna; Mazzocato, Pamela

    2017-03-20

    Purpose The purpose of this paper is to uncover the mechanisms influencing the sustainability of behavior changes following the implementation of teamwork. Design/methodology/approach Realistic evaluation was combined with a framework (DCOM®) based on applied behavior analysis to study the sustainability of behavior changes two and a half years after the initial implementation of teamwork at an emergency department. The DCOM® framework was used to categorize the mechanisms of behavior change interventions (BCIs) into the four categories of direction, competence, opportunity, and motivation. Non-participant observation and interview data were used. Findings The teamwork behaviors were not sustained. A substantial fallback in managerial activities in combination with a complex context contributed to reduced direction, opportunity, and motivation. Reduced direction made staff members unclear about how and why they should work in teams. Deterioration of opportunity was evident from the lack of problem-solving resources resulting in accumulated barriers to teamwork. Motivation in terms of management support and feedback was reduced. Practical implications The implementation of complex organizational changes in complex healthcare contexts requires continuous adaption and managerial activities well beyond the initial implementation period. Originality/value By integrating the DCOM® framework with realistic evaluation, this study responds to the call for theoretically based research on behavioral mechanisms that can explain how BCIs interact with context and how this interaction influences sustainability.

  13. Supersymmetry and Light Quark Masses in a Realistic Superstring Model

    CERN Document Server

    Halyo, E

    1994-01-01

    We examine the light quark masses in a standard--like superstring model in the four dimensional free fermionic formulation. We find that the supersymmetry constraints in the observable and hidden sectors eliminate all large contributions to $m_u$ and $m_d$ and force them to be much smaller than the other quark masses. The requirement for an acceptable Higgs doublet spectrum results in $m_u<realistic $m_d$ can always be obtained whereas $m_u$ is at most $10^{-5}~MeV$. For particular choices of flat directions or vacua $m_u$ can be as small as $10^{-7}~MeV$ but cannot vanish.

  14. Recovering the quantum formalism from physically realist axioms

    Science.gov (United States)

    Auffèves, Alexia; Grangier, Philippe

    2017-01-01

    We present a heuristic derivation of Born’s rule and unitary transforms in Quantum Mechanics, from a simple set of axioms built upon a physical phenomenology of quantization. This approach naturally leads to the usual quantum formalism, within a new realistic conceptual framework that is discussed in details. Physically, the structure of Quantum Mechanics appears as a result of the interplay between the quantized number of “modalities” accessible to a quantum system, and the continuum of “contexts” that are required to define these modalities. Mathematically, the Hilbert space structure appears as a consequence of a specific “extra-contextuality” of modalities, closely related to the hypothesis of Gleason’s theorem, and consistent with its conclusions. PMID:28256539

  15. Towards a Realistic Model for Failure Propagation in Interdependent Networks

    CERN Document Server

    Sturaro, Agostino; Conti, Mauro; Das, Sajal K

    2015-01-01

    Modern networks are becoming increasingly interdependent. As a prominent example, the smart grid is an electrical grid controlled through a communications network, which in turn is powered by the electrical grid. Such interdependencies create new vulnerabilities and make these networks more susceptible to failures. In particular, failures can easily spread across these networks due to their interdependencies, possibly causing cascade effects with a devastating impact on their functionalities. In this paper we focus on the interdependence between the power grid and the communications network, and propose a novel realistic model, HINT (Heterogeneous Interdependent NeTworks), to study the evolution of cascading failures. Our model takes into account the heterogeneity of such networks as well as their complex interdependencies. We compare HINT with previously proposed models both on synthetic and real network topologies. Experimental results show that existing models oversimplify the failure evolution and network...

  16. Realistic Haptic Rendering of Interacting Deformable Objects in Virtual Environments

    CERN Document Server

    Duriez, Christian; Kheddar, Abderrahmane; Andriot, Claude

    2008-01-01

    A new computer haptics algorithm to be used in general interactive manipulations of deformable virtual objects is presented. In multimodal interactive simulations, haptic feedback computation often comes from contact forces. Subsequently, the fidelity of haptic rendering depends significantly on contact space modeling. Contact and friction laws between deformable models are often simplified in up to date methods. They do not allow a "realistic" rendering of the subtleties of contact space physical phenomena (such as slip and stick effects due to friction or mechanical coupling between contacts). In this paper, we use Signorini's contact law and Coulomb's friction law as a computer haptics basis. Real-time performance is made possible thanks to a linearization of the behavior in the contact space, formulated as the so-called Delassus operator, and iteratively solved by a Gauss-Seidel type algorithm. Dynamic deformation uses corotational global formulation to obtain the Delassus operator in which the mass and s...

  17. Rabi Oscillations in Realistic Superlattice with Finite Bloch Bands

    Institute of Scientific and Technical Information of China (English)

    FAN Wen-Bin; ZHANG Ping; LUO Ying; ZHAO Xian-Geng

    2001-01-01

    We investigate the dynamical processes taking place in nanodevices by high-frequency dc-ac fields. We found that Rabi oscillations between minibands are clearly identified under theoretical resonant conditions derived by an ideal two-band superlattice model, the resonant conditions have broadened, and the amount of broadening is about four times of the Rabi oscillation frequency. We also want to elucidate the role of different mechanisms that could lead to loss of quantum coherence. Our results show how the dephasing effects of disorder of interface roughness and doping fluctuation that after some periods destroy coherent oscillations, such as Rabi oscillations,can be reduced dramatically if we apply a bias static electric field to the superlattice system. The doping fluctuation dephasing effect is much stronger than that of interface roughness in the coherent process of realistic superlattices.

  18. Optimal control of photoelectron emission by realistic waveforms

    CERN Document Server

    Solanpää, Janne; Räsänen, Esa

    2016-01-01

    Recent experimental techniques in multicolor waveform synthesis allow the temporal shaping of strong femtosecond laser pulses with applications in the control of quantum mechanical processes in atoms, molecules, and nanostructures. Prediction of the shapes of the optimal waveforms can be done computationally using quantum optimal control theory (QOCT). In this work we bring QOCT to experimental feasibility by providing an optimal control scheme with realistic pulse representation. We apply the technique to optimal control of above-threshold photoelectron emission from a one-dimensional hydrogen atom. By mixing different spectral channels and thus lowering the intensity requirements for individual channels, the resulting optimal pulses can extend the cutoff energies by at least up to 50% and bring up the electron yield by several orders of magnitude. Insights into the electron dynamics for optimized photoelectron emission are obtained with a semiclassical two-step model.

  19. Electron distribution in polar heterojunctions within a realistic model

    Energy Technology Data Exchange (ETDEWEB)

    Tien, Nguyen Thanh, E-mail: thanhtienctu@gmail.com [College of Natural Science, Can Tho University, 3-2 Road, Can Tho City (Viet Nam); Thao, Dinh Nhu [Center for Theoretical and Computational Physics, College of Education, Hue University, 34 Le Loi Street, Hue City (Viet Nam); Thao, Pham Thi Bich [College of Natural Science, Can Tho University, 3-2 Road, Can Tho City (Viet Nam); Quang, Doan Nhat [Institute of Physics, Vietnamese Academy of Science and Technology, 10 Dao Tan Street, Hanoi (Viet Nam)

    2015-12-15

    We present a theoretical study of the electron distribution, i.e., two-dimensional electron gas (2DEG) in polar heterojunctions (HJs) within a realistic model. The 2DEG is confined along the growth direction by a triangular quantum well with a finite potential barrier and a bent band figured by all confinement sources. Therein, interface polarization charges take a double role: they induce a confining potential and, furthermore, they can make some change in other confinements, e.g., in the Hartree potential from ionized impurities and 2DEG. Confinement by positive interface polarization charges is necessary for the ground state of 2DEG existing at a high sheet density. The 2DEG bulk density is found to be increased in the barrier, so that the scattering occurring in this layer (from interface polarization charges and alloy disorder) becomes paramount in a polar modulation-doped HJ.

  20. Bosonic structure of realistic SO(10) supersymmetric cosmic strings

    Science.gov (United States)

    Allys, Erwan

    2016-05-01

    We study the bosonic structure of F -term Nambu-Goto cosmic strings forming in a realistic SO(10) implementation, assuming standard hybrid inflation. We describe the supersymmetric grand unified theory, and its spontaneous symmetry breaking scheme in parallel with the inflationary process. We also write the explicit tensor formulation of its scalar sector, focusing on the subrepresentations singlet under the standard model, which is sufficient to describe the string structure. We then introduce an ansatz for Abelian cosmic strings, discussing in details the hypothesis, and write down the field equations and boundary conditions. Finally, after doing a perturbative study of the model, we present and discuss the results obtained with numerical solutions of the string structure.

  1. Hiding a Realistic Object Using a Broadband Terahertz Invisibility Cloak

    CERN Document Server

    Zhou, Fan; Cao, Wei; Stuart, Colin T; Gu, Jianqiang; Zhang, Weili; Sun, Cheng

    2011-01-01

    The invisibility cloak has been a long-standing dream for many researchers over the decades. The introduction of transformational optics has revitalized this field by providing a general method to design material distributions to hide the subject from detection. By transforming space and light propagation, a three-dimensional (3D) object is perceived as having a reduced number of dimensions, in the form of points, lines, and thin sheets, making it "undetectable" judging from the scattered field. Although a variety of cloaking devices have been reported at microwave and optical frequencies, the spectroscopically important Terahertz (THz) domain remains unexplored. Moreover, due to the difficulties in fabricating cloaking devices that are optically large in all three dimensions, hiding realistic 3D objects has yet to be demonstrated. Here, we report the first experimental demonstration of a 3D THz cloaking device fabricated using a scalable Projection Microstereolithography process. The cloak operates at a broa...

  2. Ultra-realistic imaging and OptoClones

    Science.gov (United States)

    Bjelkhagen, Hans I.; Lembessis, Alkiviadis; Sarakinos, Andreas

    2016-03-01

    Recent improvements in solid state CW lasers, recording materials and light sources (such as LED lights) for displaying color holograms are described. Full-color analogue holograms can now be created with substantially better image characteristics than previously possible. To record ultra-realistic images depends on selecting the optimal recording laser wavelengths and employing ultra-fine-grain, silver-halide materials. The image quality is improved by using LED display light with improved spatial coherence. Recording museum artifacts using mobile holographic equipment is described. The most recent recorded such holograms (referred to as OptoClones™) are the Fabergé Eggs at the Fabergé Museum in St. Petersburg, Russia.

  3. Unsteady velocity measurements in a realistic intracranial aneurysm model

    Science.gov (United States)

    Ugron, Ádám; Farinas, Marie-Isabelle; Kiss, László; Paál, György

    2012-01-01

    The initiation, growth and rupture of intracranial aneurysms are intensively studied by computational fluid dynamics. To gain confidence in the results of numerical simulations, validation of the results is necessary. To this end the unsteady flow was measured in a silicone phantom of a realistic intracranial aneurysm. A flow circuit was built with a novel unsteady flow rate generating method, used to model the idealised shape of the heartbeat. This allowed the measurement of the complex three-dimensional velocity distribution by means of laser-optical methods such as laser doppler anemometry (LDA) and particle image velocimetry (PIV). The PIV measurements, available with high temporal and spatial distribution, were found to have good agreement with the control LDA measurements. Furthermore, excellent agreement was found with the numerical results.

  4. Dynamics of entanglement in realistic chains of superconducting qubits

    CERN Document Server

    Tsomokos, D I; Huelga, S F; Plenio, M B

    2006-01-01

    The quantum dynamics of chains of superconducting qubits is analyzed under realistic experimental conditions. Electromagnetic fluctuations due to the background circuitry, finite temperature in the external environment, and disorder in the initial preparation and the control parameters are taken into account. It is shown that the amount of disorder that is typically present in current experiments does not affect the entanglement dynamics significantly. However, the effect of the environmental noise can modify entanglement generation and propagation across the chain. We study the persistence of coherent effects in the presence of noise and possible ways to efficiently detect the presence of quantum entanglement. We also discuss under which circumstances the system exhibits steady state entanglement for both short (N30) chains and show that there are parameter regimes where the steady state entanglement is strictly non-monotonic as a function of the noise strength. We present optimized schemes for entanglement ...

  5. Magnetic exchange at realistic CoO/Ni interfaces

    KAUST Repository

    Grytsyuk, Sergiy

    2012-07-30

    We study the CoO/Ni interface by first principles calculations. Because the lattice mismatch is large, a realistic description requires a huge supercell. We investigate two interface configurations: in interface 1 the coupling between the Ni and Co atoms is mediated by O, whereas in interface 2 the Ni and Co atoms are in direct contact. We find that the magnetization (including the orbital moment) in interface 1 has a similar value as in bulk Ni but opposite sign, while in interface 2 it grows by 164%. The obtained magnetic moments can be explained by the local atomic environments. In addition, we find effects of charge transfer between the interface atoms. The Co 3d local density of states of interface 2 exhibits surprisingly small deviations from the corresponding bulk result, although the first coordination sphere is no longer octahedral. © Springer-Verlag 2012.

  6. DEVELOPMENT OF REALISTIC QUALITY LOSS FUNCTIONS FOR INDUSTRIAL APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    Abdul-Baasit SHAIBU; Byung Rae CHO

    2006-01-01

    A number of quality loss functions, most recently the Taguchi loss function, have been developed to quantify the loss due to the deviation of product performance from the desired target value. All these loss functions assume the same loss at the specified specification limits. In many real life industrial applications, however, the losses at the two different specifications limits are often not the same.Further, current loss functions assume a product should be reworked or scrapped if product performance falls outside the specification limits. It is a common practice in many industries to replace a defective item rather than spending resources to repair it, especially if considerable amount of time is required. To rectify these two potential problems, this paper proposes more realistic quality loss functions for proper applications to real-world industrial problems. This paper also carries out a comparison studies of all the loss functions it considers.

  7. Mergers of binary neutron stars with realistic spin

    CERN Document Server

    Bernuzzi, Sebastiano; Tichy, Wolfgang; Bruegmann, Bernd

    2013-01-01

    Simulations of binary neutron stars have seen great advances in terms of physical detail and numerical quality. However, the spin of the neutron stars, one of the simplest global parameters of binaries, remains mostly unstudied. We present the first, fully nonlinear general relativistic dynamical evolutions of the last three orbits for constraint satisfying initial data of spinning neutron star binaries, with astrophysically realistic spins aligned and anti-aligned to the orbital angular momentum. The initial data is computed with the constant rotational velocity approach. The dynamics of the systems is analyzed in terms of gauge-invariant binding energy vs. orbital angular momentum curves. By comparing to a binary black hole configuration we can estimate the different tidal and spin contributions to the binding energy for the first time. First results on the gravitational wave forms are presented. The phase evolution during the orbital motion is significantly affected by spin-orbit interactions, leading to d...

  8. Application of the Probabilistic Dynamic Synthesis Method to Realistic Structures

    Science.gov (United States)

    Brown, Andrew M.; Ferri, Aldo A.

    1998-01-01

    The Probabilistic Dynamic Synthesis method is a technique for obtaining the statistics of a desired response engineering quantity for a structure with non-deterministic parameters. The method uses measured data from modal testing of the structure as the input random variables, rather than more "primitive" quantities like geometry or material variation. This modal information is much more comprehensive and easily measured than the "primitive" information. The probabilistic analysis is carried out using either response surface reliability methods or Monte Carlo simulation. In previous work, the feasibility of the PDS method applied to a simple seven degree-of-freedom spring-mass system was verified. In this paper, extensive issues involved with applying the method to a realistic three-substructure system are examined, and free and forced response analyses are performed. The results from using the method are promising, especially when the lack of alternatives for obtaining quantitative output for probabilistic structures is considered.

  9. Tool for Generating Realistic Residential Hot Water Event Schedules: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Hendron, B.; Burch, J.; Barker, G.

    2010-08-01

    The installed energy savings for advanced residential hot water systems can depend greatly on detailed occupant use patterns. Quantifying these patterns is essential for analyzing measures such as tankless water heaters, solar hot water systems with demand-side heat exchangers, distribution system improvements, and recirculation loops. This paper describes the development of an advanced spreadsheet tool that can generate a series of year-long hot water event schedules consistent with realistic probability distributions of start time, duration and flow rate variability, clustering, fixture assignment, vacation periods, and seasonality. This paper also presents the application of the hot water event schedules in the context of an integral-collector-storage solar water heating system in a moderate climate.

  10. Mode engineering for realistic quantum-enhanced interferometry.

    Science.gov (United States)

    Jachura, Michał; Chrapkiewicz, Radosław; Demkowicz-Dobrzański, Rafał; Wasilewski, Wojciech; Banaszek, Konrad

    2016-04-29

    Quantum metrology overcomes standard precision limits by exploiting collective quantum superpositions of physical systems used for sensing, with the prominent example of non-classical multiphoton states improving interferometric techniques. Practical quantum-enhanced interferometry is, however, vulnerable to imperfections such as partial distinguishability of interfering photons. Here we introduce a method where appropriate design of the modal structure of input photons can alleviate deleterious effects caused by another, experimentally inaccessible degree of freedom. This result is accompanied by a laboratory demonstration that a suitable choice of spatial modes combined with position-resolved coincidence detection restores entanglement-enhanced precision in the full operating range of a realistic two-photon Mach-Zehnder interferometer, specifically around a point which otherwise does not even attain the shot-noise limit due to the presence of residual distinguishing information in the spectral degree of freedom. Our method highlights the potential of engineering multimode physical systems in metrologic applications.

  11. Towards More Realistic Simulation of Air-Sea Interaction over Lakes on Titan

    Science.gov (United States)

    Rafkin, Scot; Soto, Alejandro

    2016-06-01

    The exchange of methane between the atmosphere and surface liquid reservoirs dominates the short time-scale methanological cycle. In this study, previous two-dimensional simulations of the exchange of methane vapor, sensible heat and momentum between the atmosphere and lakes are updated with the inclusion of radiative forcing and extended to three dimensions, including the introduction of realistic coastlines. Previous studies of Titan's air-sea exchange in two dimensions suggested that the exchange process was self-limiting. Evaporation from lakes produced a shallow but extremely stable marine layer that suppressed turbulent exchange. Furthermore, the circulation associated with the higher buoyancy of methane-rich atmosphere over the lake was offset by the oppositely directed thermal sea breeze circulation, which muted the mean wind. Two major weaknesses of this previous work were the lack of radiative forcing and the imposition of two dimensionality that limited the full range of dynamical solutions. Based on early theoretical studies, it was thought that magnitude of turbulent energy flux exchanges would be much larger than radiative fluxes, thereby justifying the neglect of radiation, but the two-dimensional simulations indicated that this was not a valid assumption. The dynamical limitations of two-dimensional simulations are well known. Vorticity stretching (i.e., circulation intensification through vertical motion) is not possible and it is also not possible to produce dynamically balanced gradient wind-type circulations. As well, the irregular shape of a realistic coastline cannot be expressed in two dimensions, and these realistic structures will generally induce complex convergence and divergence circulations in the atmosphere. The impact of radiative forcing and the addition of the third dimension on the air-sea exchange are presented.

  12. Critical reflections on realist review: insights from customizing the methodology to the needs of participatory research assessment.

    Science.gov (United States)

    Jagosh, Justin; Pluye, Pierre; Wong, Geoff; Cargo, Margaret; Salsberg, Jon; Bush, Paula L; Herbert, Carol P; Green, Lawrence W; Greenhalgh, Trish; Macaulay, Ann C

    2014-06-01

    Realist review has increased in popularity as a methodology for complex intervention assessment. Our experience suggests that the process of designing a realist review requires its customization to areas under investigation. To elaborate on this idea, we first describe the logic underpinning realist review and then present critical reflections on our application experience, organized in seven areas. These are the following: (1) the challenge of identifying middle range theory; (2) addressing heterogeneity and lack of conceptual clarity; (3) the challenge of appraising the quality of complex evidence; (4) the relevance of capturing unintended outcomes; (5) understanding the process of context, mechanism, and outcome (CMO) configuring; (6) incorporating middle-range theory in the CMO configuration process; and (7) using middle range theory to advance the conceptualization of outcomes - both visible and seemingly 'hidden'. One conclusion from our experience is that the degree of heterogeneity of the evidence base will determine whether theory can drive the development of review protocols from the outset, or will follow only after an intense period of data immersion. We hope that presenting a critical reflection on customizing realist review will convey how the methodology can be tailored to the often complex and idiosyncratic features of health research, leading to innovative evidence syntheses.

  13. Sociology of pharmaceuticals development and regulation: a realist empirical research programme.

    Science.gov (United States)

    Abraham, John

    2008-09-01

    A realist conceptualization of interests is proposed in opposition to the fashionable view that interests, objectivity and reality are merely social constructs, and that sociological analyses should be confined to discourse, actor-networks and micro-contextual practices. The objective interests of pharmaceutical companies in profit-maximization, and of patients/public health in the optimisation of drugs' benefit-risk ratios, can be empirically validated. The relationship between those interests and pharmaceutical regulation is best characterised by 'neo-liberal corporate bias' at the macro- and meso-levels. How such bias manifests itself at the micro-social level of science-based pharmaceutical testing and regulatory decision making is examined using a realist sociology of scientific knowledge, which appreciates that assessment of the validity of techno-scientific knowledge claims is essential for their sociological explanation. Commercial interests are shown to have biased science away from the interests of public health, in favour of industry. International comparisons of drug regulation demonstrate that drug injuries are not necessarily an inevitable by-product of pharmaceutical progress because some countries have fewer drug safety problems than others. Similarly, the lowering of techno-scientific standards for drug safety testing is not an inevitable cost of faster development of therapeutically valuable medicines, but a consequence of the internationalization of neo-liberal corporate bias.

  14. Realistic multi-cellular dosimetry for 177Lu-labelled antibodies: model and application

    Science.gov (United States)

    Marcatili, S.; Pichard, A.; Courteau, A.; Ladjohounlou, R.; Navarro-Teulon, I.; Repetto-Llamazares, A.; Heyerdahl, H.; Dahle, J.; Pouget, J. P.; Bardiès, M.

    2016-10-01

    Current preclinical dosimetric models often fail to take account of the complex nature of absorbed dose distribution typical of in vitro clonogenic experiments in targeted radionuclide therapy. For this reason, clonogenic survival is often expressed as a function of added activity rather than the absorbed dose delivered to cells/cell nuclei. We designed a multi-cellular dosimetry model that takes into account the realistic distributions of cells in the Petri dish, for the establishment of survival curves as a function of the absorbed dose. General-purpose software tools were used for the generation of realistic, randomised 3D cell culture geometries based on experimentally determined parameters (cell size, cell density, cluster density, average cluster size, cell cumulated activity). A mixture of Monte Carlo and analytical approaches was implemented in order to achieve as accurate as possible results while reducing calculation time. The model was here applied to clonogenic survival experiments carried out to compare the efficacy of Betalutin®, a novel 177Lu-labelled antibody radionuclide conjugate for the treatment of non-Hodgkin lymphoma, to that of 177Lu-labelled CD20-specific (rituximab) and non-specific antibodies (Erbitux) on lymphocyte B cells. The 3D cellular model developed allowed a better understanding of the radiative and non-radiative processes associated with cellular death. Our approach is generic and can also be applied to other radiopharmaceuticals and cell distributions.

  15. Introducing a more realistic model for opinion formation considering instability in social structure

    Science.gov (United States)

    Salehi, Sajjad; Taghiyareh, Fattaneh

    2016-06-01

    Opinion formation is a process through which interactions of individuals and dynamism of their opinions in effect of neighbors are modeled. In this paper, in an effort to model the opinion formation more realistically, we have introduced a model that considers the role of network structure in opinion dynamics. In this model, each individual changes his opinion in a way so as to decrease its difference with the opinion of trusted neighbors while he intensifies his dissention with the untrusted ones. Considering trust/distrust relations as a signed network, we have defined a structural indicator which shows the degree of instability in social structure and is calculated based on the structural balance theory. It is also applied as feedback to the opinion formation process affecting its dynamics. Our simulation results show formation of a set of clusters containing individuals holding opinions having similar values. Also, the opinion value of each individual is far from the ones of distrusted neighbors. Since this model considers distrust and instability of relations in society, it can offer a more realistic model of opinion formation.

  16. Development of a realistic, dynamic digital brain phantom for CT perfusion validation

    Science.gov (United States)

    Divel, Sarah E.; Segars, W. Paul; Christensen, Soren; Wintermark, Max; Lansberg, Maarten G.; Pelc, Norbert J.

    2016-03-01

    Physicians rely on CT Perfusion (CTP) images and quantitative image data, including cerebral blood flow, cerebral blood volume, and bolus arrival delay, to diagnose and treat stroke patients. However, the quantification of these metrics may vary depending on the computational method used. Therefore, we have developed a dynamic and realistic digital brain phantom upon which CTP scans can be simulated based on a set of ground truth scenarios. Building upon the previously developed 4D extended cardiac-torso (XCAT) phantom containing a highly detailed brain model, this work consisted of expanding the intricate vasculature by semi-automatically segmenting existing MRA data and fitting nonuniform rational B-spline surfaces to the new vessels. Using time attenuation curves input by the user as reference, the contrast enhancement in the vessels changes dynamically. At each time point, the iodine concentration in the arteries and veins is calculated from the curves and the material composition of the blood changes to reflect the expected values. CatSim, a CT system simulator, generates simulated data sets of this dynamic digital phantom which can be further analyzed to validate CTP studies and post-processing methods. The development of this dynamic and realistic digital phantom provides a valuable resource with which current uncertainties and controversies surrounding the quantitative computations generated from CTP data can be examined and resolved.

  17. Numerical analysis of the Fokker-Planck equation with adiabatic focusing: Realistic pitch-angle scattering

    Science.gov (United States)

    Lasuik, J.; Fiege, J. D.; Shalchi, A.

    2017-01-01

    We solve the focused transport equation of cosmic rays numerically to investigate non-isotropic models of the pitch-angle scattering coefficient. In previous work, the Fokker-Planck equation was solved either analytically by using approximations, or by using a numerical approach together with simple models for the pitch-angle scattering coefficient. It is the purpose of the current article so compute particle distribution functions as well as the parallel diffusion coefficient by solving numerically the focused transport equation for a more realistic Fokker-Planck coefficient of pitch-angle scattering. Our analytical form for the scattering parameter is based on non-linear diffusion theory that takes into account realistic scattering at pitch-angles close to 90 ° . This general form contains the isotropic form as well as the quasi-linear limit as special cases. We show that the ratio of the diffusion coefficients with and without focusing sensitively depends on the ratio of the turbulent magnetic field and the mean field. The assumed form of the pitch-angle Fokker-Planck coefficient has an influence on the parallel diffusion coefficient. In all considered cases we found a reduction of the ratio of the diffusion coefficients if the ratio of magnetic fields is reduced.

  18. Meredys, a multi-compartment reaction-diffusion simulator using multistate realistic molecular complexes

    Directory of Open Access Journals (Sweden)

    Le Novère Nicolas

    2010-03-01

    Full Text Available Abstract Background Most cellular signal transduction mechanisms depend on a few molecular partners whose roles depend on their position and movement in relation to the input signal. This movement can follow various rules and take place in different compartments. Additionally, the molecules can form transient complexes. Complexation and signal transduction depend on the specific states partners and complexes adopt. Several spatial simulator have been developed to date, but none are able to model reaction-diffusion of realistic multi-state transient complexes. Results Meredys allows for the simulation of multi-component, multi-feature state molecular species in two and three dimensions. Several compartments can be defined with different diffusion and boundary properties. The software employs a Brownian dynamics engine to simulate reaction-diffusion systems at the reactive particle level, based on compartment properties, complex structure, and hydro-dynamic radii. Zeroth-, first-, and second order reactions are supported. The molecular complexes have realistic geometries. Reactive species can contain user-defined feature states which can modify reaction rates and outcome. Models are defined in a versatile NeuroML input file. The simulation volume can be split in subvolumes to speed up run-time. Conclusions Meredys provides a powerful and versatile way to run accurate simulations of molecular and sub-cellular systems, that complement existing multi-agent simulation systems. Meredys is a Free Software and the source code is available at http://meredys.sourceforge.net/.

  19. Milky Way mass and potential recovery using tidal streams in a realistic halo

    Energy Technology Data Exchange (ETDEWEB)

    Bonaca, Ana; Geha, Marla [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Küpper, Andreas H. W.; Johnston, Kathryn V. [Department of Astronomy, Columbia University, New York, NY 027 (United States); Diemand, Jürg [Institute for Computational Sciences, University of Zürich, 8057 Zurich (Switzerland); Hogg, David W., E-mail: ana.bonaca@yale.edu [Center for Cosmology and Particle Physics, Department of Physics, New York University, 4 Washington Place # 424, New York, NY 10003 (United States)

    2014-11-01

    We present a new method for determining the Galactic gravitational potential based on forward modeling of tidal stellar streams. We use this method to test the performance of smooth and static analytic potentials in representing realistic dark matter halos, which have substructure and are continually evolving by accretion. Our FAST-FORWARD method uses a Markov Chain Monte Carlo algorithm to compare, in six-dimensional phase space, an 'observed' stream to models created in trial analytic potentials. We analyze a large sample of streams that evolved in the Via Lactea II (VL2) simulation, which represents a realistic Galactic halo potential. The recovered potential parameters are in agreement with the best fit to the global, present-day VL2 potential. However, merely assuming an analytic potential limits the dark matter halo mass measurement to an accuracy of 5%-20%, depending on the choice of analytic parameterization. Collectively, the mass estimates using streams from our sample reach this fundamental limit, but individually they can be highly biased. Individual streams can both under- and overestimate the mass, and the bias is progressively worse for those with smaller perigalacticons, motivating the search for tidal streams at galactocentric distances larger than 70 kpc. We estimate that the assumption of a static and smooth dark matter potential in modeling of the GD-1- and Pal5-like streams introduces an error of up to 50% in the Milky Way mass estimates.

  20. 360 degree realistic 3D image display and image processing from real objects

    Science.gov (United States)

    Luo, Xin; Chen, Yue; Huang, Yong; Tan, Xiaodi; Horimai, Hideyoshi

    2016-09-01

    A 360-degree realistic 3D image display system based on direct light scanning method, so-called Holo-Table has been introduced in this paper. High-density directional continuous 3D motion images can be displayed easily with only one spatial light modulator. Using the holographic screen as the beam deflector, 360-degree full horizontal viewing angle was achieved. As an accompany part of the system, CMOS camera based image acquisition platform was built to feed the display engine, which can take a full 360-degree continuous imaging of the sample at the center. Customized image processing techniques such as scaling, rotation, format transformation were also developed and embedded into the system control software platform. In the end several samples were imaged to demonstrate the capability of our system.

  1. 360 degree realistic 3D image display and image processing from real objects

    Science.gov (United States)

    Luo, Xin; Chen, Yue; Huang, Yong; Tan, Xiaodi; Horimai, Hideyoshi

    2016-12-01

    A 360-degree realistic 3D image display system based on direct light scanning method, so-called Holo-Table has been introduced in this paper. High-density directional continuous 3D motion images can be displayed easily with only one spatial light modulator. Using the holographic screen as the beam deflector, 360-degree full horizontal viewing angle was achieved. As an accompany part of the system, CMOS camera based image acquisition platform was built to feed the display engine, which can take a full 360-degree continuous imaging of the sample at the center. Customized image processing techniques such as scaling, rotation, format transformation were also developed and embedded into the system control software platform. In the end several samples were imaged to demonstrate the capability of our system.

  2. 部分贫困山区农村教学点的写实性研究——以江西赣南地区某县农村教学点为例%A Realistic Research on the Rural Teaching Spot in Some Poverty-Stricken Mountain Area ——,Based on Teaching Spots in Gannan District

    Institute of Scientific and Technical Information of China (English)

    徐冠春; 焦中明

    2012-01-01

    通过对经济欠发达的赣南地区10所农村教学点学校的实地调研,结果表明:山区农村教学点的教学环境较差、教学经费严重不足,教学质量不能适应教育事业的发展。但在农村学校撤并调整过程中,交通不便的山区农村点还有存在的必要。%The realistic research results show that some 10 rural teaching spots in Gannan District in undeveloped areas have such gaps in teaching surroundings, teaching investments and teaching qualities. But, some rural teaching spots should be put into use in the areas where the traffic means are poor while somes schools are removed or amalgamated.

  3. Time-Distance Helioseismology of Two Realistic Sunspot Simulations

    CERN Document Server

    DeGrave, K; Rempel, M

    2014-01-01

    Linear time-distance helioseismic inversions are carried out using several filtering schemes to determine vector flow velocities within two $\\sim100^2\\,{\\rm Mm^2}\\times 20\\,{\\rm Mm}$ realistic magnetohydrodynamic sunspot simulations of 25~hr. One simulation domain contains a model of a full sunspot (i.e. one with both an umbra and penumbra), while the other contains a pore (i.e. a spot without a penumbra). The goal is to test current helioseismic methods using these state-of-the-art simulations of magnetic structures. We find that horizontal flow correlations between inversion and simulation flow maps are reasonably high ($\\sim0.5$--0.8) in the upper 3~Mm at distances exceeding 25--30~Mm from spot center, but are substantially lower at smaller distances and larger depths. Inversions of forward-modeled travel times consistently outperform those of our measured travel times in terms of horizontal flow correlations, suggesting that our inability to recover flow structure near these active regions is largely due ...

  4. Validating Time-Distance Helioseismology With Realistic Quiet Sun Simulations

    CERN Document Server

    DeGrave, K; Rempel, M

    2014-01-01

    Linear time-distance helioseismic inversions are carried out for vector flow velocities using travel times measured from two $\\sim 100^2\\,{\\rm Mm^2}\\times 20\\,{\\rm Mm}$ realistic magnetohydrodynamic quiet-Sun simulations of about 20 hr. The goal is to test current seismic methods on these state-of-the-art simulations. Using recent three-dimensional inversion schemes, we find that inverted horizontal flow maps correlate well with the simulations in the upper $\\sim 3$ Mm of the domains for several filtering schemes, including phase-speed, ridge, and combined phase-speed and ridge measurements. In several cases, however, the velocity amplitudes from the inversions severely underestimate those of the simulations, possibly indicating nonlinearity of the forward problem. We also find that, while near-surface inversions of the vertical velocites are best using phase-speed filters, in almost all other example cases these flows are irretrievable due to noise, suggesting a need for statistical averaging to obtain bette...

  5. Modelisation of synchrotron radiation losses in realistic tokamak plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Albajar, F.; Johner, J.; Granata, G

    2000-08-01

    Synchrotron radiation losses become significant in the power balance of high-temperature plasmas envisaged for next step tokamaks. Due to the complexity of the exact calculation, these losses are usually roughly estimated with expressions derived from a plasma description using simplifying assumptions on the geometry, radiation absorption, and density and temperature profiles. In the present article, the complete formulation of the transport of synchrotron radiation is performed for realistic conditions of toroidal plasma geometry with elongated cross-section, using an exact method for the calculation of the absorption coefficient, and for arbitrary shapes of density and temperature profiles. The effects of toroidicity and temperature profile on synchrotron radiation losses are analyzed in detail. In particular, when the electron temperature profile is almost flat in the plasma center, as for example in ITB confinement regimes, synchrotron losses are found to be much stronger than in the case where the profile is represented by its best generalized parabolic approximation, though both cases give approximately the same thermal energy contents. Such an effect is not included in present approximate expressions. Finally, we propose a seven-variable fit for the fast calculation of synchrotron radiation losses. This fit is derived from a large database, which has been generated using a code implementing the complete formulation and optimized for massively parallel computing. (author)

  6. Knowing how to look predicts the ability to draw realistically.

    Science.gov (United States)

    Drake, Jennifer E

    2014-11-01

    Some young children are able to create stunningly realistic drawings resembling those of adult artists. What perceptual abilities underlie this talent? This study examined two candidate skills on which adult artists excel: the ability to segment a complex form mentally (measured by the Block Design Task) and the ability to see hidden forms (measured by the Group Embedded Figures Test). Sixty-seven 6- to 13-year-olds with a wide range of drawing abilities completed these tasks as well as an IQ test and an observational drawing task. While children who scored high on drawing realism outperformed those who scored low in drawing realism on both perceptual tasks, only detection of embedded figures predicted drawing realism. This occurred independently of age, gender, years of training, and verbal and non-verbal IQ. There are certainly many contributors to this complex ability, but one component appears to be the tendency to see things more as they really are and thereby recognize the continuous contour of an object despite interference from other overlapping objects.

  7. A Data-Driven Approach to Realistic Shape Morphing

    KAUST Repository

    Gao, Lin

    2013-05-01

    Morphing between 3D objects is a fundamental technique in computer graphics. Traditional methods of shape morphing focus on establishing meaningful correspondences and finding smooth interpolation between shapes. Such methods however only take geometric information as input and thus cannot in general avoid producing unnatural interpolation, in particular for large-scale deformations. This paper proposes a novel data-driven approach for shape morphing. Given a database with various models belonging to the same category, we treat them as data samples in the plausible deformation space. These models are then clustered to form local shape spaces of plausible deformations. We use a simple metric to reasonably represent the closeness between pairs of models. Given source and target models, the morphing problem is casted as a global optimization problem of finding a minimal distance path within the local shape spaces connecting these models. Under the guidance of intermediate models in the path, an extended as-rigid-as-possible interpolation is used to produce the final morphing. By exploiting the knowledge of plausible models, our approach produces realistic morphing for challenging cases as demonstrated by various examples in the paper. © 2013 The Eurographics Association and Blackwell Publishing Ltd.

  8. Trends in Alaska temperature data. Towards a more realistic approach

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-de-Lacalle, Javier [University of the Basque Country, Department of Applied Economics III (Econometrics and Statistics), Bilbao (Spain)

    2012-06-15

    Time series of seasonal temperatures recorded in Alaska during the past eighty years are analyzed. A common practice to measure changes in the long-term pattern of temperature series is to fit a deterministic linear trend. A deterministic trend is not a realistic approach and poses some pitfalls from the statistical point of view. A statistical model to fit a latent time-varying level independent of the Pacific climate shift is proposed. The empirical distribution of temperature conditional on the phase of the Pacific Decadal Oscillation is obtained. The results reveal that the switch between the negative and the positive phase leads to differences in temperatures up to 4 C in a given location and season. Differences across seasons and locations are detected. The effect of the Pacific climate shift is stronger in winter. An overall increase of temperatures is observed in the long term. The estimated trends are not constant but exhibit different patterns that vary in the sign and strength over the sample period. (orig.)

  9. Experimental Study of Aerosol Deposition in a Realistic Lung Model

    Directory of Open Access Journals (Sweden)

    František LÍZAL

    2010-12-01

    Full Text Available The inhalation route for administration of medicaments is becoming more and more popular in recent years. The reason is non-invasiveness of the method and instantaneous absorption of drugs to the blood circulation. It is necessary to deliver exact amount of drug to the specific segment because of occurrence of diverse diseases in different segments of lungs. The aim of our work is to contribute to better understanding of transport and deposition of aerosolized drugs in lungs and hence to more effective treatment of respiratory diseases due to the targeted drug delivery. We provided measurements of aerosol deposition in segmented realistic model of lungs without a mouth cavity. Monodisperse particles marked with fluorescein were supplied to the model. The model was then disassembled to segments and each segment was rinsed with isopropanol, whereby fluorescent samples were created. Each sample was analysed by fluorometer and an amount of aerosol deposited in the segment was calculated. Experiences obtained by this study were used for creation of a new model with the mouth cavity. This model will be used for future studies with porous and fiber aerosols.

  10. High Energy Atmospheric Neutrino Fluxes From a Realistic Primary Spectrum

    Science.gov (United States)

    Campos Penha, Felipe; Dembinski, Hans; Gaisser, Thomas K.; Tilav, Serap

    2016-03-01

    Atmospheric neutrino fluxes depend on the energy spectrum of primary nucleons entering the top of the atmosphere. Before the advent of AMANDA and the IceCube Neutrino Observatory, measurements of the neutrino fluxes were generally below ~ 1TeV , a regime in which a simple energy power law sufficed to describe the primary spectrum. Now, IceCube's muon neutrino data extends beyond 1PeV , including a combination of neutrinos from astrophysical sources with background from atmospheric neutrinos. At such high energies, the steepening at the knee of the primary spectrum must be accounted for. Here, we describe a semi-analytical approach for calculating the atmospheric differential neutrino fluxes at high energies. The input is a realistic primary spectrum consisting of 4 populations with distinct energy cutoffs, each with up to 7 representative nuclei, where the parameters were extracted from a global fit. We show the effect of each component on the atmospheric neutrino spectra, above 10TeV . The resulting features follow directly from recent air shower measurements included in the fit. Felipe Campos Penha gratefully acknowledges financial support from CAPES (Processo BEX 5348/14-5), CNPq (Processo 142180/2012-2), and the Bartol Research Institute.

  11. Realistic Stellar Feedback & Bulge Formation in Clumpy Disks

    CERN Document Server

    Hopkins, Philip F; Murray, Norman; Quataert, Eliot; Hernquist, Lars

    2012-01-01

    We use numerical simulations of isolated galaxies to study the effects of realistic stellar feedback on the formation and evolution of giant star-forming gas 'clumps' in high-redshift, gas-rich galaxies. Such galactic disks are unstable to the formation of bound gas-rich clumps whose properties initially depend only on global disk properties, not the microphysics of feedback. In simulations without stellar feedback, clumps turn an order-unity fraction of their mass into stars and sink to the center, forming a large bulge and kicking most of the stars out into a much more extended stellar envelope. By contrast, stellar feedback disrupts even the most massive clumps after they turn ~10-20% of their mass into stars, in a timescale of ~10-100 Myr, ejecting some material into a super-wind and recycling the rest of the gas into the diffuse ISM. This suppresses the bulge formation rate by direct 'clump coalescence' by a factor of several. However, the galactic disks do undergo significant secular evolution in the ab...

  12. Uncovering gender discrimination cues in a realistic setting.

    Science.gov (United States)

    Dupuis-Roy, Nicolas; Fortin, Isabelle; Fiset, Daniel; Gosselin, Frédéric

    2009-02-10

    Which face cues do we use for gender discrimination? Few studies have tried to answer this question and the few that have tried typically used only a small set of grayscale stimuli, often distorted and presented a large number of times. Here, we reassessed the importance of facial cues for gender discrimination in a more realistic setting. We applied Bubbles-a technique that minimizes bias toward specific facial features and does not necessitate the distortion of stimuli-to a set of 300 color photographs of Caucasian faces, each presented only once to 30 participants. Results show that the region of the eyes and the eyebrows-probably in the light-dark channel-is the most important facial cue for accurate gender discrimination; and that the mouth region is driving fast correct responses (but not fast incorrect responses)-the gender discrimination information in the mouth region is concentrated in the red-green color channel. Together, these results suggest that, when color is informative in the mouth region, humans use it and respond rapidly; and, when it's not informative, they have to rely on the more robust but more sluggish luminance information in the eye-eyebrow region.

  13. A computational study of routing algorithms for realistic transportation networks

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, R.; Marathe, M.V.; Nagel, K.

    1998-12-01

    The authors carry out an experimental analysis of a number of shortest path (routing) algorithms investigated in the context of the TRANSIMS (Transportation Analysis and Simulation System) project. The main focus of the paper is to study how various heuristic and exact solutions, associated data structures affected the computational performance of the software developed especially for realistic transportation networks. For this purpose the authors have used Dallas Fort-Worth road network with very high degree of resolution. The following general results are obtained: (1) they discuss and experimentally analyze various one-one shortest path algorithms, which include classical exact algorithms studied in the literature as well as heuristic solutions that are designed to take into account the geometric structure of the input instances; (2) they describe a number of extensions to the basic shortest path algorithm. These extensions were primarily motivated by practical problems arising in TRANSIMS and ITS (Intelligent Transportation Systems) related technologies. Extensions discussed include--(i) time dependent networks, (ii) multi-modal networks, (iii) networks with public transportation and associated schedules. Computational results are provided to empirically compare the efficiency of various algorithms. The studies indicate that a modified Dijkstra`s algorithm is computationally fast and an excellent candidate for use in various transportation planning applications as well as ITS related technologies.

  14. Super stereoscopy technique for comfortable and realistic 3D displays.

    Science.gov (United States)

    Akşit, Kaan; Niaki, Amir Hossein Ghanbari; Ulusoy, Erdem; Urey, Hakan

    2014-12-15

    Two well-known problems of stereoscopic displays are the accommodation-convergence conflict and the lack of natural blur for defocused objects. We present a new technique that we name Super Stereoscopy (SS3D) to provide a convenient solution to these problems. Regular stereoscopic glasses are replaced by SS3D glasses which deliver at least two parallax images per eye through pinholes equipped with light selective filters. The pinholes generate blur-free retinal images so as to enable correct accommodation, while the delivery of multiple parallax images per eye creates an approximate blur effect for defocused objects. Experiments performed with cameras and human viewers indicate that the technique works as desired. In case two, pinholes equipped with color filters per eye are used; the technique can be used on a regular stereoscopic display by only uploading a new content, without requiring any change in display hardware, driver, or frame rate. Apart from some tolerable loss in display brightness and decrease in natural spatial resolution limit of the eye because of pinholes, the technique is quite promising for comfortable and realistic 3D vision, especially enabling the display of close objects that are not possible to display and comfortably view on regular 3DTV and cinema.

  15. Helping With All Your Heart: Realistic Heart Stimulus and Compliance With an Organ Donation Request.

    Science.gov (United States)

    Jacob, Céline; Guéguen, Nicolas

    2015-01-01

    Pictures and images are important aspects in fundraising advertising and could generate more donations. In two experimental studies, we examined the effect of various pictures of hearts on compliance with a request for organ donations. The solicitor wore a white tee shirt where various forms of hearts were printed: symbolic versus realistic (first experiment), none versus symbolic versus realistic (second experiment). Results showed that more compliance was found in the realistic heart experimental condition whereas the symbolic heart form had no significant effect.

  16. Development and validation of a realistic head model for EEG

    Science.gov (United States)

    Bangera, Nitin Bhalchandra

    The utility of extracranial electrical or magnetic field recordings (EEG or MEG) is greatly enhanced if the generators of the bioelectromagnetic fields can be determined accurately from the measured fields. This procedure, known as the 'inverse method,' depends critically on calculations of the projection from generators in the brain to the EEG and MEG sensors. Improving and validating this calculation, known as the 'forward solution,' is the focus of this dissertation. The improvements involve more accurate modeling of the structures of the brain and thus understanding how current flows within the brain as a result of addition of structures in the forward model. Validation compares calculations using different forward models to the experimental results obtained by stimulating with implanted dipole electrodes. The human brain tissue displays inhomogeneity in electrical conductivity and also displays anisotropy, notably in the skull and brain white matter. In this dissertation, a realistic head model has been implemented using the finite element method to calculate the effects of inhomogeneity and anisotropy in the human brain. Accurate segmentation of the brain tissue type is implemented using a semi-automatic method to segment multimodal imaging data from multi-spectral MRI scans (different flip angles) in conjunction with the regular T1-weighted scans and computed x-ray tomography images. The electrical conductivity in the anisotropic white matter tissue is quantified from diffusion tensor MRI. The finite element model is constructed using AMIRA, a commercial segmentation and visualization tool and solved using ABAQUS, a commercial finite element solver. The model is validated using experimental data collected from intracranial stimulation in medically intractable epileptic patients. Depth electrodes are implanted in medically intractable epileptic patients in order to direct surgical therapy when the foci cannot be localized with the scalp EEG. These patients

  17. Multimodal person authentication on a smartphone under realistic conditions

    Science.gov (United States)

    Morris, Andrew C.; Jassim, Sabah; Sellahewa, Harin; Allano, Lorene; Ehlers, Johan; Wu, Dalei; Koreman, Jacques; Garcia-Salicetti, Sonia; Ly-Van, Bao; Dorizzi, Bernadette

    2006-05-01

    Verification of a person's identity by the combination of more than one biometric trait strongly increases the robustness of person authentication in real applications. This is particularly the case in applications involving signals of degraded quality, as for person authentication on mobile platforms. The context of mobility generates degradations of input signals due to the variety of environments encountered (ambient noise, lighting variations, etc.), while the sensors' lower quality further contributes to decrease in system performance. Our aim in this work is to combine traits from the three biometric modalities of speech, face and handwritten signature in a concrete application, performing non intrusive biometric verification on a personal mobile device (smartphone/PDA). Most available biometric databases have been acquired in more or less controlled environments, which makes it difficult to predict performance in a real application. Our experiments are performed on a database acquired on a PDA as part of the SecurePhone project (IST-2002-506883 project "Secure Contracts Signed by Mobile Phone"). This database contains 60 virtual subjects balanced in gender and age. Virtual subjects are obtained by coupling audio-visual signals from real English speaking subjects with signatures from other subjects captured on the touch screen of the PDA. Video data for the PDA database was recorded in 2 recording sessions separated by at least one week. Each session comprises 4 acquisition conditions: 2 indoor and 2 outdoor recordings (with in each case, a good and a degraded quality recording). Handwritten signatures were captured in one session in realistic conditions. Different scenarios of matching between training and test conditions are tested to measure the resistance of various fusion systems to different types of variability and different amounts of enrolment data.

  18. Realistic Models for Filling Factors in HII Regions

    Science.gov (United States)

    Spangler, Steven R.; Costa, Allison H.; Bergerud, Brandon M.; Beauchamp, Kara M.

    2017-01-01

    One of the parameters used to describe HII regions and other ionized parts of the interstellar medium is the filling factor, defined as the volume fraction of an HII region occupied by matter. The best observational evidence for the existence of a filling factor less than unity is a discrepancy between the electron density derived from density-sensitive line ratios and the root mean square density obtained from emission measure measurements. Following the early, influential study by Osterbrock and Flather (ApJ 129, 26, 1959), most investigations of HII regions envision these objects as a group of isolated cells of high gas density embedded in a vacuum. This picture is at serious odds with more direct measurements of other astrophysical plasmas like the solar wind, where the density follows a less extreme probability distribution function (pdf) such as an exponential or lognormal. We have carried out a set of simulations in which model HII regions are created with different density pdfs such as exponential and lognormal as well as the extreme case of two delta functions. We calculate the electron density as inferred from spectroscopic line ratios and emission measures for all lines of sight through the model nebulas. In the cases of exponential and lognormal pdfs, the spectroscopically derived densities are higher than those obtained by the emission measures by factors of 20 to 100 percent. These are considerably smaller than values often reported in the literature, which can be an order of magnitude or greater. We will discuss possible ways to reconcile realistic density pdfs such as measured in space and laboratory plasmas with the results from astronomical spectroscopic measurements. Finally, we point out that for the Orion Nebula, the density discrepancy is due to geometry, not filling factor (O'Dell, ARAA 39, 99, 2001).

  19. A Critical Realistic Masterpiece of Mark Twain——The Adventures of Huckleberry Finn

    Institute of Scientific and Technical Information of China (English)

    赵红石

    2009-01-01

    In mid and late 19th century,appeared a new literary trend-critical realism.The critical realists described with much vividness and artistic skill the chief traits(characteristics) of the society and criticized the capitalist system from a democratic viewpoint.Mark Twain is one of the greatest representatives of critical realists.All the critical realistic features can be found in his novel The Adventures of Huckleberry Finn. This essay is devoted to analyze the critical realistic elements of The Adventures of Huckleberry Finn.

  20. Numerical modeling of Po-218 deposition in a physiologically realistic lung bifurcation model

    Science.gov (United States)

    Mously-Soroujy, Khalid Ahmad

    Experimental data for lung bifurcations reveals complex geometries and distinct asymmetrical characteristic, which affects the localized distribution of particles deposited in the lung. This study is based on recently published numerical results for a symmetric physiological realistic bifurcation geometry Heistracher and Hofmann (1995) which has been extended here to the case of a asymmetric geometry. The asymmetric PRB model was used to study the flow field and the deposition of ultrafine particles for inspiratory and expiratory conditions. In the present study, we investigated the effect of different flow rates, representing human activity and deposition of different ultrafine particles representing radon daughter (Po-218), in the PRB model. Numerical results were compared with the limited available experimental and numerical data. The fluid dynamic computer program FIDAP was used for this purpose.

  1. Turbulent transport measurements in a cold model of GT-burner at realistic flow rates

    Science.gov (United States)

    Gobyzov, Oleg; Chikishev, Leonid; Lobasov, Alexey; Sharaborin, Dmitriy; Dulin, Vladimir; Bilsky, Artur; Tsatiashvili, Vakhtang; Avgustinovich, Valery; Markovich, Dmitriy

    2016-03-01

    In the present work simultaneous velocity field and passive admixture concentration field measurements at realistic flow-rates conditions in a non-reacting flow in a model of combustion chamber with an industrial mixing device are reported. In the experiments for safety reasons the real fuel (natural gas) was replaced with neon gas to simulate stratification in a strongly swirling flow. Measurements were performed by means of planar laser-induced fluorescence (PLIF) and particle image velocimetry technique (PIV) at Reynolds number, based on the mean flow rate and nozzle diameter, ≈300 000. Details on experimental technique, features of the experimental setup, images and data preprocessing procedures and results of performed measurements are given in the paper. In addition to the raw velocity and admixture concentration data in-depth evaluation approaches aimed for estimation of turbulent kinetic energy (TKE) components, assessment of turbulent Schmidt number and analysis of the gradient closure hypothesis from experimental data are presented in the paper.

  2. Realistic Significance and Practical Exploration of Cultivating New Professional Farmers in China

    Institute of Scientific and Technical Information of China (English)

    Chunming; GONG; Hui; NI

    2013-01-01

    Firstly, the background, ways, countermeasures, problems and realistic significance of cultivating new professional farmers in China were studied, and then the mechanism for cultivating new professional farmers was discussed based on Town S. The results show that cultivating new professional farmers can fundamentally relieve "three rural issues" existing for a long time and is of great significance to rural economic development. For instance, it can integrate rural human capital and release modern productivity, increase farmers’ income and improve rural economy, increase land utilization and output per unit area, and break through the bottlenecks during agricultural development to realize agricultural modernization. According to the case study of Town S, during the process of cultivating new professional farmers, governments at all levels ought to adopt many effective measures and strengthen support to realize cultivation targets planed early.

  3. Onset of Convection in Porous Medium Saturated by Viscoelastic Nanofluid: More Realistic Result

    Directory of Open Access Journals (Sweden)

    A. Srivastava

    2016-01-01

    Full Text Available The present paper deals with the linear thermal instability analysis of viscoelastic nanofluid saturated porous layer. We consider a set of new boundary conditions for the nanoparticle fraction, which is physically more realistic. The new boundary condition is based on the assumption that the nanoparticle fraction adjusts itself so that the nanoparticle flux is zero on the boundaries. We use Oldroyd-B type viscoelastic fluid that incorporates the effects of Brownian motion and thermophoresis. Expressions for stationary and oscillatory modes of convection have been obtained in terms of the Rayleigh number, which are found to be functions of various parameters. The numerical results have been presented through graphs.

  4. Simulating a dual-recycled gravitational wave interferometer with realistically imperfect optics

    CERN Document Server

    Bochner, B

    2003-01-01

    We simulate the performance of a gravitational wave interferometer in the Dual Recycling (DR) configuration, as will be used for systems like Advanced-LIGO. Our grid-based simulation program models complex interferometric detectors with realistic optical deformations (e.g., fine-scale mirror surface roughness). Broadband and Tuned DR are modeled here; the results are also applied qualitatively to Resonant Sideband Extraction (RSE). Several beneficial properties anticipated for DR detectors are investigated: signal response tuning and narrowbanding, power loss reduction, and the reclamation of lost power as useful light for signal detection. It is shown that these benefits would be limited by large scattering losses in large (multi-kilometer) systems. Furthermore, losses may be resonantly enhanced (particularly for RSE), if the interferometer's modal resonance conditions are not well chosen. We therefore make two principal recommendations for DR/RSE interferometers: the DR/RSE cavity must be modally nondegener...

  5. Multiplexing efficiency for MIMO antenna-channel impairment characterisation in realistic multipath environments

    DEFF Research Database (Denmark)

    Chen, Xiaoming; Zhang, Shuai

    2016-01-01

    Multiple-input multiple-output (MIMO) systems in multipath environments suffer from high correlations (in the presence of small angular spreads of propagation waves and similar antenna patterns) and power imbalances [(due to cross-polarisation discrimination (XPD) of the propagation channel...... and possibly different antenna efficiencies)]. A simple performance metric that takes into account of the antenna-channel impairments on the MIMO system will be of great value for MIMO antenna characterizations. In this work, a generalized multiplexing efficiency (ME) is derived, which takesing into account...... efficiencyME, we use both the correlation-based channel model (where correlations and power imbalances can be readily specified) and the more realistic WINNER+ channel model (where correlations and power imbalances have to be indirectly controlled by changing the antenna setup)....

  6. Using a realist approach to evaluate smoking cessation interventions targeting pregnant women and young people

    Directory of Open Access Journals (Sweden)

    van Teijlingen Edwin R

    2010-02-01

    Full Text Available Abstract Background This paper describes a study protocol designed to evaluate a programme of smoking cessation interventions targeting pregnant women and young people living in urban and rural locations in Northeast Scotland. The study design was developed on so-called 'realist' evaluation principles, which are concerned with the implementation of interventions as well as their outcomes. Methods/design A two-phased study was designed based on the Theory of Change (TOC using mixed methods to assess both process and outcome factors. The study was designed with input from the relevant stakeholders. The mixed-methods approach consists of semi-structured interviews with planners, service providers, service users and non-users. These qualitative interviews will be analysed using a thematic framework approach. The quantitative element of the study will include the analysis of routinely collected data and specific project monitoring data, such as data on service engagement, service use, quit rates and changes in smoking status. Discussion The process of involving key stakeholders was conducted using logic modelling and TOC tools. Engaging stakeholders, including those responsible for funding, developing and delivering, and those intended to benefit from interventions aimed at them, in their evaluation design, are considered by many to increase the validity and rigour of the subsequent evidence generated. This study is intended to determine not only the components and processes, but also the possible effectiveness of this set of health interventions, and contribute to the evidence base about smoking cessation interventions aimed at priority groups in Scotland. It is also anticipated that this study will contribute to the ongoing debate about the role and challenges of 'realist' evaluation approaches in general, and the utility of logic modelling and TOC approaches in particular, for evaluation of complex health interventions.

  7. Model of a realistic InP surface quantum dot extrapolated from atomic force microscopy results.

    Science.gov (United States)

    Barettin, Daniele; De Angelis, Roberta; Prosposito, Paolo; Auf der Maur, Matthias; Casalboni, Mauro; Pecchia, Alessandro

    2014-05-16

    We report on numerical simulations of a zincblende InP surface quantum dot (QD) on In₀.₄₈Ga₀.₅₂ buffer. Our model is strictly based on experimental structures, since we extrapolated a three-dimensional dot directly by atomic force microscopy results. Continuum electromechanical, [Formula: see text] bandstructure and optical calculations are presented for this realistic structure, together with benchmark calculations for a lens-shape QD with the same radius and height of the extrapolated dot. Interesting similarities and differences are shown by comparing the results obtained with the two different structures, leading to the conclusion that the use of a more realistic structure can provide significant improvements in the modeling of QDs fact, the remarkable splitting for the electron p-like levels of the extrapolated dot seems to prove that a realistic experimental structure can reproduce the right symmetry and a correct splitting usually given by atomistic calculations even within the multiband [Formula: see text] approach. Moreover, the energy levels and the symmetry of the holes are strongly dependent on the shape of the dot. In particular, as far as we know, their wave function symmetries do not seem to resemble to any results previously obtained with simulations of zincblende ideal structures, such as lenses or truncated pyramids. The magnitude of the oscillator strengths is also strongly dependent on the shape of the dot, showing a lower intensity for the extrapolated dot, especially for the transition between the electrons and holes ground state, as a result of a relevant reduction of the wave functions overlap. We also compare an experimental photoluminescence spectrum measured on an homogeneous sample containing about 60 dots with a numerical ensemble average derived from single dot calculations. The broader energy range of the numerical spectrum motivated us to perform further verifications, which have clarified some aspects of the experimental

  8. Compression, Modeling, and Real-Time Rendering of Realistic Materials and Objects

    OpenAIRE

    Menzel, Nicolas

    2012-01-01

    The realism of a scene basically depends on the quality of the geometry, the illumination and the materials that are used. Whereas many sources for the creation of three-dimensional geometry exist and numerous algorithms for the approximation of global illumination were presented, the acquisition and rendering of realistic materials remains a challenging problem. Realistic materials are very important in computer graphics, because...

  9. The Performance of Chinese Primary School Students on Realistic Arithmetic Word Problems

    Science.gov (United States)

    Xin, Ziqiang; Lin, Chongde; Zhang, Li; Yan, Rong

    2007-01-01

    Compared with standard arithmetic word problems demanding only the direct use of number operations and computations, realistic problems are harder to solve because children need to incorporate "real-world" knowledge into their solutions. Using the realistic word problem testing materials developed by Verschaffel, De Corte, and Lasure…

  10. Simulating realistic disc galaxies with a novel sub-resolution ISM model

    Science.gov (United States)

    Murante, Giuseppe; Monaco, Pierluigi; Borgani, Stefano; Tornatore, Luca; Dolag, Klaus; Goz, David

    2015-02-01

    We present results of cosmological simulations of disc galaxies carried out with the GADGET-3 TreePM+SPH code, where star formation and stellar feedback are described using our MUlti Phase Particle Integrator model. This description is based on a simple multiphase model of the interstellar medium at unresolved scales, where mass and energy flows among the components are explicitly followed by solving a system of ordinary differential equations. Thermal energy from supernovae is injected into the local hot phase, so as to avoid that it is promptly radiated away. A kinetic feedback prescription generates the massive outflows needed to avoid the overproduction of stars. We use two sets of zoomed-in initial conditions of isolated cosmological haloes with masses (2-3) × 1012 M⊙, both available at several resolution levels. In all cases we obtain spiral galaxies with small bulge-over-total stellar mass ratios (B/T ˜ 0.2), extended stellar and gas discs, flat rotation curves and realistic values of stellar masses. Gas profiles are relatively flat, molecular gas is found to dominate at the centre of galaxies, with star formation rates following the observed Schmidt-Kennicutt relation. Stars kinematically belonging to the bulge form early, while disc stars show a clear inside-out formation pattern and mostly form after redshift z = 2. However, the baryon conversion efficiencies in our simulations differ from the relation given by Moster et al. at a 3σ level, thus indicating that our stellar discs are still too massive for the dark matter halo in which they reside. Results are found to be remarkably stable against resolution. This further demonstrates the feasibility of carrying out simulations producing a realistic population of galaxies within representative cosmological volumes, at a relatively modest resolution.

  11. Disentangling Islamophobia: The Differential Effects of Symbolic, Realistic, and Terroristic Threat Perceptions as Mediators Between Social Dominance Orientation and Islamophobia

    Directory of Open Access Journals (Sweden)

    Fatih Uenal

    2016-04-01

    Full Text Available The aim of this paper is threefold. First, based on ongoing theoretical discussions on the dimensionality of Islamophobia, this study analyzes whether Islamophobia empirically constitutes a one-dimensional construct or rather a multidimensional construct consisting of anti-Muslim prejudice and anti-Islam sentiment. Second, the effects of symbolic, realistic, and terroristic (safety threats on Islamophobia were analyzed concurrently. Finally, within the framework of the revised Integrated Threat Theory (Stephan & Renfro, 2002, and in order to test the mediating effect of threats, SDO is tested as an antecedent of perceived threat and Islamophobia. Respondents from Berlin (N = 355 participated in an online survey. The results indicate that Islamophobia empirically constitutes a two-dimensional phenomenon, consisting of anti-Muslim and anti-Islam sentiment. Whereas symbolic threat is related to both types of Islamophobia, realistic threat is associated only with anti-Muslim prejudice, and terroristic threat is associated only with anti-Islam sentiment. Finally, the results indicate that the relationship between SDO and both dimensions of Islamophobia is mediated by threats. Symbolic threats mediate the relationships between SDO and both dimensions of Islamophobia. Realistic threats mediate the relationship between SDO and anti-Muslim prejudice and terroristic threats between SDO and anti-Islam sentiment.

  12. A Dose of Reality: Radiation Analysis for Realistic Human Spacecraft

    Science.gov (United States)

    Barzilla, J. E.; Lee, K. T.

    2017-01-01

    racks and components, was simplified to remove holes and volume overlaps. Problematic features within the drawing were also removed or repaired to prevent runtime issues. The cleaned drawing was then run through the DAGMC workflow to prepare for analysis. Pilot tests modeling transport of 1GeV proton and 800MeV/A oxygen sources show that reasonable results are converged upon in an acceptable amount of overall computation time from drawing preparation to data analysis. The FLUKA radiation transport code will next be used to model both a GCR and a trapped radiation source. These results will then be compared with measurements that have been made by the radiation instrumentation deployed inside the US Lab module. DISCUSSION Early analyses have indicated that the DAGMC workflow is a promising toolkit for running vehicle geometries of interest to NASA through multiple radiation transport codes. In addition, recent work has shown that a realistic human phantom, provided via a subcontract with the University of Florida, can be placed inside any vehicle geometry for a combinatorial analysis. This added functionality gives the user the ability to score various parameters at the organ level, and the results can then be used as input for cancer risk models.

  13. Development of Sensor Based Applications for the Android Platform: an Approach Based on Realistic Simulation

    Directory of Open Access Journals (Sweden)

    Pablo CAMPILLO-SÁNCHEZ

    2013-05-01

    Full Text Available Smart phones are equipped with a wide range of sensors (such as GPS, light, accelerometer, gyroscope, etc. and allow users to be connected everywhere. These characteristics offer a rich information source for creating context-aware applications. However, testing these applications in the lab, before their deployment, could become a hard task or impossible because of sensors correlation, too wide testing area or an excessive number of people involved. This work aims to solve these problems carrying out the testing in a simulator, simulating the world in which the application user is immersed into. Tester controls her avatar and the avatar has a simulated smart phone that is connected with the user’s smart phone. Applications under test are installed on the real smart phone and are compiled with a library that replaces standard services of the sensors by others that offer data sensor from the simulator (depending on the simulated smart phone context instead of real world.

  14. Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

    Directory of Open Access Journals (Sweden)

    Woo Chul Jeong

    2015-08-01

    Full Text Available Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.

  15. Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

    Science.gov (United States)

    Jeong, Woo Chul; Wi, Hun; Sajib, Saurav Z. K.; Oh, Tong In; Kim, Hyung Joong; Kwon, Oh In; Woo, Eung Je

    2015-08-01

    Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR)-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.

  16. English as a Medium of Instruction in East Asia's Higher Education Sector: A Critical Realist Cultural Political Economy Analysis of Underlying Logics

    Science.gov (United States)

    Kedzierski, Matt

    2016-01-01

    As discourses of globalisation and the knowledge-based economy become increasingly influential in both policy-making and in public debates about education, employability and national competitiveness--the choice of language in the classroom takes on a strategic importance. The paper employs a critical realist Cultural Political Economy lens to…

  17. The Effect of Realistic Mathematics Education Approach on Students' Achievement And Attitudes Towards Mathematics

    Directory of Open Access Journals (Sweden)

    Effandi Zakaria

    2017-02-01

    Full Text Available This study was conducted to determine the effect of Realistic Mathematics Education Approach on mathematics achievement and student attitudes towards mathematics. This study also sought determine the relationship between student achievement and attitudes towards mathematics. This study used a quasi-experimental design conducted on 61 high school students at SMA Unggul Sigli. Students were divided into two groups, the treatment group $(n = 30$ namely, the Realistic Mathematics Approach group (PMR and the control group $(n = 31$ namely, the traditional group. This study was conducted for six weeks. The instruments used in this study were the achievement test and the attitudes towards mathematics questionnaires. Data were analyzed using SPSS. To determine the difference in mean achievement and attitudes between the two groups, data were analyzed using one-way ANOVA test. The result showed significant differences between the Realistic Mathematics Approach and the traditional approach in terms of achievement. The study showed no significant difference between the Realistic Mathematics Approach and the traditional approach in term of attitudes towards mathematics. It can be concluded that the use of realistic mathematics education approach enhanced students' mathematics achievement, but not attitudes towards mathematics. The Realistic Mathematics Education Approach encourage students to participate actively in the teaching and learning of mathematics. Thus, Realistic Mathematics Education Approach is an appropriate methods to improve the quality of teaching and learning process.

  18. Leggett-type nonlocal realistic inequalities without any constraint on the geometrical alignment of measurement settings

    Science.gov (United States)

    Rai, Ashutosh; Home, Dipankar; Majumdar, A. S.

    2011-11-01

    Leggett-type nonlocal realistic inequalities that have been derived to date are all contingent upon suitable geometrical constraints to be strictly satisfied by the spatial arrangement of the relevant measurement settings. This undesirable restriction is removed in the present work by deriving appropriate forms of nonlocal realistic inequalities, one of which involves the fewest number of settings compared to all such inequalities derived earlier. The way such inequalities would provide a logically firmer basis for a clearer testing of a Leggett-type nonlocal realistic model vis-à-vis quantum mechanics is explained.

  19. Optimized methods for epilepsy therapy development using an etiologically realistic model of focal epilepsy in the rat.

    Science.gov (United States)

    Eastman, Clifford L; Fender, Jason S; Temkin, Nancy R; D'Ambrosio, Raimondo

    2015-02-01

    Conventionally developed antiseizure drugs fail to control epileptic seizures in about 30% of patients, and no treatment prevents epilepsy. New etiologically realistic, syndrome-specific epilepsy models are expected to identify better treatments by capturing currently unknown ictogenic and epileptogenic mechanisms that operate in the corresponding patient populations. Additionally, the use of electrocorticography permits better monitoring of epileptogenesis and the full spectrum of acquired seizures, including focal nonconvulsive seizures that are typically difficult to treat in humans. Thus, the combined use of etiologically realistic models and electrocorticography may improve our understanding of the genesis and progression of epilepsy, and facilitate discovery and translation of novel treatments. However, this approach is labor intensive and must be optimized. To this end, we used an etiologically realistic rat model of posttraumatic epilepsy, in which the initiating fluid percussion injury closely replicates contusive closed-head injury in humans, and has been adapted to maximize epileptogenesis and focal non-convulsive seizures. We obtained week-long 5-electrode electrocorticography 1 month post-injury, and used a Monte-Carlo-based non-parametric bootstrap strategy to test the impact of electrode montage design, duration-based seizure definitions, group size and duration of recordings on the assessment of posttraumatic epilepsy, and on statistical power to detect antiseizure and antiepileptogenic treatment effects. We found that use of seizure definition based on clinical criteria rather than event duration, and of recording montages closely sampling the activity of epileptic foci, maximize the power to detect treatment effects. Detection of treatment effects was marginally improved by prolonged recording, and 24h recording epochs were sufficient to provide 80% power to detect clinically interesting seizure control or prevention of seizures with small groups

  20. Systematic Comparison of Jet Energy-Loss Schemes in a realistic hydrodynamic medium

    CERN Document Server

    Bass, Steffen A; Majumder, Abhijit; Nonaka, Chiho; Qin, Guang-You; Renk, Thorsten; Ruppert, Jörg

    2008-01-01

    We perform a systematic comparison of three different jet energy-loss approaches. These include the Armesto-Salgado-Wiedemann scheme based on the approach of Baier-Dokshitzer-Mueller-Peigne-Schiff (BDMPS/ASW), the Higher Twist approach (HT) and a scheme based on the approach of Arnold-Moore-Yaffe (AMY). In this comparison, an identical medium evolution will be utilized for all three approaches: not only does this entail the use of the same realistic three-dimensional relativistic fluid dynamics (RFD) simulation, but also includes the use of identical initial parton-distribution functions and final fragmentation functions. We are, thus, in a unique position, not only to isolate fundamental differences between the various approaches, but also to make rigorous calculations for different experimental measurements using "state of the art" components. All three approaches are reduced to a version which contains only one free tunable parameter, this is then related to the well known transport parameter $\\hat{q}$. We...

  1. Analytical solution to transient Richards' equation with realistic water profiles for vertical infiltration and parameter estimation

    Science.gov (United States)

    Hayek, Mohamed

    2016-06-01

    A general analytical model for one-dimensional transient vertical infiltration is presented. The model is based on a combination of the Brooks and Corey soil water retention function and a generalized hydraulic conductivity function. This leads to power law diffusivity and convective term for which the exponents are functions of the inverse of the pore size distribution index. Accordingly, the proposed analytical solution covers many existing realistic models in the literature. The general form of the analytical solution is simple and it expresses implicitly the depth as function of water content and time. It can be used to model infiltration through semi-infinite dry soils with prescribed water content or flux boundary conditions. Some mathematical expressions of practical importance are also derived. The general form solution is useful for comparison between models, validation of numerical solutions and for better understanding the effect of some hydraulic parameters. Based on the analytical expression, a complete inverse procedure which allows the estimation of the hydraulic parameters from water content measurements is presented.

  2. Model of Ni-63 battery with realistic PIN structure

    Energy Technology Data Exchange (ETDEWEB)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah, E-mail: aougazza@georgiatech-metz.fr [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); School of Electrical and Computer Engineering, Georgia Institute of Technology, 777 Atlantic Drive NW, 30332-0250 Atlanta (United States); Arif, Muhammad; Salvestrini, Jean-Paul [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Université de Lorraine, CentraleSupélec, LMOPS, EA 4423, 2 rue E. Belin, 57070 Metz (France); Streque, Jeremy; El Gmili, Youssef [Georgia Tech Lorraine, Georgia Tech-C.N.R.S., UMI2958, 2-3 rue Marconi, 57070 Metz (France); Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim [Laboratory for Photonics and Nanostructures, CNRS, Route de Nozay, 91460 Marcoussis (France)

    2015-09-14

    GaN, with its wide bandgap of 3.4 eV, has emerged as an efficient material for designing high-efficiency betavoltaic batteries. An important part of designing efficient betavoltaic batteries involves a good understanding of the full process, from the behavior of the nuclear material and the creation of electron-hole pairs all the way through the collection of photo-generated carriers. This paper presents a detailed model based on Monte Carlo and Silvaco for a GaN-based betavoltaic battery device, modeled after Ni-63 as an energy source. The accuracy of the model is verified by comparing it with experimental values obtained for a GaN-based p-i-n structure under scanning electron microscope illumination.

  3. Comparative analysis of the effectiveness of three immunization strategies in controlling disease outbreaks in realistic social networks.

    Science.gov (United States)

    Xu, Zhijing; Zu, Zhenghu; Zheng, Tao; Zhang, Wendou; Xu, Qing; Liu, Jinjie

    2014-01-01

    The high incidence of emerging infectious diseases has highlighted the importance of effective immunization strategies, especially the stochastic algorithms based on local available network information. Present stochastic strategies are mainly evaluated based on classical network models, such as scale-free networks and small-world networks, and thus are insufficient. Three frequently referred stochastic immunization strategies-acquaintance immunization, community-bridge immunization, and ring vaccination-were analyzed in this work. The optimal immunization ratios for acquaintance immunization and community-bridge immunization strategies were investigated, and the effectiveness of these three strategies in controlling the spreading of epidemics were analyzed based on realistic social contact networks. The results show all the strategies have decreased the coverage of the epidemics compared to baseline scenario (no control measures). However the effectiveness of acquaintance immunization and community-bridge immunization are very limited, with acquaintance immunization slightly outperforming community-bridge immunization. Ring vaccination significantly outperforms acquaintance immunization and community-bridge immunization, and the sensitivity analysis shows it could be applied to controlling the epidemics with a wide infectivity spectrum. The effectiveness of several classical stochastic immunization strategies was evaluated based on realistic contact networks for the first time in this study. These results could have important significance for epidemic control research and practice.

  4. Predictive atomistic simulations of electronic properties of realistic nanoscale devices: A multiscale modeling approach

    Science.gov (United States)

    Vedula, Ravi Pramod Kumar

    profiles, inherent in strain-engineered Ge nanofins, on their transport properties. Fully atomistic simulations, involving a combination molecular dynamics simulations with first-principles based force-fields and semi-empirical tight binding calculations, coupled with linearized Boltzmann model are used to calculate the hole transport properties of realistic Ge nanofins (heights 5-15nm and widths 5nm-40nm). Our simulations predict the technological limit of phonon limited hole mobility improvement in Ge channel PMOS devices (Hengineer high performance uniaxial devices conducive to the existing top-down fabrication approaches. From these calculations, we demonstrate that realistic modeling of the devices requires a reduction in the empiricism of fitting parameters and incorporation of new multi-scale, multi-resolution approach spanning across various spatial and temporal scales. Such physics based predictive multiscale models facilitate an integrated approach for rapid development and pave the way for designing new advanced materials and devices.

  5. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene%Coniferous Canopy BRF Simulation Based on3-D Realistic Scene

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-yun; GUO Zhi-feng; QINWen-hans; SUN Guo-qing

    2011-01-01

    It is difficulties for the computer simulation method to study radiation regime at large-scale.Simplified coniferous model was investigated in the present study.It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerful in remote sensing of heterogeneous coniferous forests over a large-scale region.L-systems is applied to render 3-D coniferous forest scenarios,and RGM model was used to calculate BRF (bidirectional reflectance factor) in visible and near-infrared regions.Results in this study show that in most cases both agreed well Meanwhile at a tree and forest level,the results are also good.

  6. The need for and development of behaviourally realistic agents

    NARCIS (Netherlands)

    Jager, W; Janssen, M; Sichman, JS; Bousquet, F; Davidsson, P

    2003-01-01

    In this paper we argue that simulating complex systems involving human behaviour requires agent rules based on a theoretically rooted structure that captures basic behavioural processes. Essential components of such a structure involve needs, decision-making processes and learning. Such a structure

  7. Restricted dynamic programming: A flexible framework for solving realistic VRP's.

    NARCIS (Netherlands)

    Gromicho, J.; Hoorn, van J.J.; Kok, A.L.; Schutten, J.M.J.

    2012-01-01

    Most solution methods for solving large vehicle routing and scheduling problems are based on local search. A drawback of these approaches is that they are designed and optimized for specific types of vehicle routing problems (VRPs). As a consequence, it is hard to adapt these solution methods to han

  8. Restricted dynamic programming: a flexible framework for solving realistic VRPs

    NARCIS (Netherlands)

    Gromicho, J.; Hoorn, van J.J.; Kok, A.L.; Schutten, J.M.J.

    2009-01-01

    Most solution methods for solving large vehicle routing and schedu- ling problems are based on local search. A drawback of these ap- proaches is that they are designed and optimized for specific types of vehicle routing problems (VRPs). As a consequence, it is hard to adapt these solution methods to

  9. Simulation of realistic background noise using multiple loudspeakers

    DEFF Research Database (Denmark)

    Song, Wookeun; Marschall, Marton; Gil Corrales, Juan David

    2015-01-01

    optimizes the reproduced sound at a sweet spot in the center of the array with radius determined by a spherical microphone array, which is used to derive the spherical harmonics decomposition of the reference sound. The four-loudspeaker-based method equalizes the magnitude response at the ears of a head...

  10. The Realistic and Romantic Factors of Marriage--Pride and PrejudiceThe Realistic and Romantic Factors of Marriage--Pride

    Institute of Scientific and Technical Information of China (English)

    李坤

    2011-01-01

    Jane Austen is one of the most important realistic novelists in the 19th century in British Literature. In her masterpiece "Pride and Prejudice", she discusses the relationship between women and marriage, and her attitudes towards successful marriage. Jan

  11. An efficient program to construct restriction maps from experimental data with realistic error levels.

    OpenAIRE

    1984-01-01

    A novel algorithm has been developed to map restriction fragments, starting from experimental size values with realistic error rates. A high performing PASCAL program has been derived from this algorithm to construct linear maps in minimal computation times.

  12. Computational investigation of nonlinear microwave tomography on anatomically realistic breast phantoms

    DEFF Research Database (Denmark)

    Jensen, P. D.; Rubæk, Tonny; Mohr, J. J.

    2013-01-01

    The performance of a nonlinear microwave tomography algorithm is tested using simulated data from anatomically realistic breast phantoms. These tests include several different anatomically correct breast models from the University of Wisconsin-Madison repository with and without tumors inserted....

  13. Can realistic interaction be useful for nuclear mean-field approaches?

    Energy Technology Data Exchange (ETDEWEB)

    Nakada, H.; Sugiura, K. [Chiba University, Department of Physics, Graduate School of Science, Inage, Chiba (Japan); Inakura, T. [Chiba University, Department of Physics, Graduate School of Science, Inage, Chiba (Japan); Kyoto University, Yukawa Institute of Theoretical Physics, Sakyo, Kyoto (Japan); Niigata University, Department of Physics, Niigata (Japan); Margueron, J. [Universite de Lyon 1, CNRS/IN2P3, Institut de Physique Nucleaire de Lyon, Villeurbanne (France)

    2016-07-15

    Recent applications of the M3Y-type semi-realistic interaction to the nuclear mean-field approaches are presented: (i) Prediction of magic numbers and (ii) isotope shifts of nuclei with magic proton numbers. The results exemplify that the realistic interaction, which is derived from the bare 2N and 3N interaction, furnishes a new theoretical instrument for advancing nuclear mean-field approaches. (orig.)

  14. Applying a realistic evaluation model to occupational safety interventions

    DEFF Research Database (Denmark)

    Pedersen, Louise Møller

    2017-01-01

    Background: Recent literature characterizes occupational safety interventions as complex social activities, applied in complex and dynamic social systems. Hence, the actual outcomes of an intervention will vary, depending on the intervention, the implementation process, context, personal...... and qualitative methods. This revised model has, however, not been applied in a real life context. Method: The model is applied in a controlled, four-component, integrated behaviour-based and safety culture-based safety intervention study (2008-2010) in a medium-sized wood manufacturing company. The interventions...... involve the company’s safety committee, safety manager, safety groups and 130 workers. Results: The model provides a framework for more valid evidence of what works within injury prevention. Affective commitment and role behaviour among key actors are identified as crucial for the implementation...

  15. The ontological indifference: A realist reading of Kant and Hegel

    OpenAIRE

    2015-01-01

    The article challenges the first premise of „speculative realism“, according to which, with Kant, the contact with the outside world was lost. Instead, it will be shown that the possibility of realism received its major impulse from two grand figures of German Idealism, from Kant as a precursor of the Romantic period and from Hegel as its, albeit critical, philosophical culmination. Based on three possible relations of knowledge to its outside, three ontolo...

  16. Generating Realistic Environments for Cyber Operations Development, Testing, and Training

    Science.gov (United States)

    2011-10-01

    HTTP Content Analysis: Real Versus Generated URLs and URIs ................................. 8  Figure 5. SMTP Content Analysis: Real ( Enron ) Versus...capture for comparison. Content results are based on the Enron email dataset [12], and a simulated SMTP traffic. Clauset et.al showed that power-law...SMTP Content Analysis: Real ( Enron ) Versus Generated Emails Sent and Unique Subject Lines 4.2 Behavioral Measuring Behavioral Realism is a

  17. Reproduction of Realistic Background Noise for Testing Telecommunications Devices

    DEFF Research Database (Denmark)

    Gil Corrales, Juan David; Song, Wookeun; MacDonald, Ewen

    2015-01-01

    A method for reproduction of sound, based on crosstalk cancellation using inverse filters, was implemented in the context of testing telecommunications devices. The effect of the regularization parameter, number of loudspeakers, type of background noise, and a technique to attenuate audible...... artifacts, were investigated. The quality of the reproduced sound was evaluated both objectively and subjectively with respect to the reference sounds, at points where telecommunications devices would be potentially placed around the head. The highest regularization value gave the best results...

  18. Towards More Realistic Mobility Model in Vehicular Ad Hoc Network

    OpenAIRE

    Dhananjay S. Gaikwad; Mahesh Lagad; Prashant Suryawanshi; Vaibhav Maske

    2012-01-01

    Mobility models or the movement patterns of nodes communicating wirelessely, play a vital role in the simulation-based evaluation of vehicular Ad Hoc Networks (VANETs). Even though recent research has developed models that better corresponds to real world mobility, we still have a limited understanding of the level of the required level of mobility details for modeling and simulating VANETs. In this paper, we propose a new mobility model for VANETs that works on the city area and map the topo...

  19. A realistic neural mass model of the cortex with laminar-specific connections and synaptic plasticity - evaluation with auditory habituation.

    Directory of Open Access Journals (Sweden)

    Peng Wang

    Full Text Available In this work we propose a biologically realistic local cortical circuit model (LCCM, based on neural masses, that incorporates important aspects of the functional organization of the brain that have not been covered by previous models: (1 activity dependent plasticity of excitatory synaptic couplings via depleting and recycling of neurotransmitters and (2 realistic inter-laminar dynamics via laminar-specific distribution of and connections between neural populations. The potential of the LCCM was demonstrated by accounting for the process of auditory habituation. The model parameters were specified using Bayesian inference. It was found that: (1 besides the major serial excitatory information pathway (layer 4 to layer 2/3 to layer 5/6, there exists a parallel "short-cut" pathway (layer 4 to layer 5/6, (2 the excitatory signal flow from the pyramidal cells to the inhibitory interneurons seems to be more intra-laminar while, in contrast, the inhibitory signal flow from inhibitory interneurons to the pyramidal cells seems to be both intra- and inter-laminar, and (3 the habituation rates of the connections are unsymmetrical: forward connections (from layer 4 to layer 2/3 are more strongly habituated than backward connections (from Layer 5/6 to layer 4. Our evaluation demonstrates that the novel features of the LCCM are of crucial importance for mechanistic explanations of brain function. The incorporation of these features into a mass model makes them applicable to modeling based on macroscopic data (like EEG or MEG, which are usually available in human experiments. Our LCCM is therefore a valuable building block for future realistic models of human cognitive function.

  20. Theoretical and applied research on bistable dual-piezoelectric-cantilever vibration energy harvesting toward realistic ambience

    Science.gov (United States)

    Gao, Y.; Leng, Y.; Javey, A.; Tan, D.; Liu, J.; Fan, S.; Lai, Z.

    2016-11-01

    Pink noise, which is similar to realistic ambient noise, is normally used to simulate ambience where a piezoelectric energy harvesting system (PEHS) is set up. However, pink noise with standard spectral representation can only be used to simulate excitations assumed to possess constant intensity, whereas realistic ambient noise normally appears with a random spectrum and varying intensity in terms of different locations and time. The output performance of conventional bistable magnetic repulsive energy harvesters is significantly affected by the ambience intensity. Considering this fact, a model bistable dual-piezoelectric-cantilever energy harvester (DPEH) is developed in this study to achieve optimal broadband energy harvesting under a varying-intensity realistic circumstance. We utilized various realistic ambient conditions as excitations to obtain the DPEH energy harvesting performance for theoretical and applied study. The elastically supported PEHS has been proven to be more adaptive to realistic ambience with significant or medium intensity variation, but is less qualified for realistic ambience with constant intensity compared with the rigidly supported PEHS (RPEHS). Fortunately, the dual-piezoelectric-cantilever energy harvesting system is superior to the RPEHS under all circumstances because the dual-piezoelectric cantilevers are efficiently utilized for electromechanical energy conversion to realize optimal energy harvesting.

  1. More-Realistic Digital Modeling of a Human Body

    Science.gov (United States)

    Rogge, Renee

    2010-01-01

    A MATLAB computer program has been written to enable improved (relative to an older program) modeling of a human body for purposes of designing space suits and other hardware with which an astronaut must interact. The older program implements a kinematic model based on traditional anthropometric measurements that do provide important volume and surface information. The present program generates a three-dimensional (3D) whole-body model from 3D body-scan data. The program utilizes thin-plate spline theory to reposition the model without need for additional scans.

  2. Realistic Measurement of Student Attendance in LMS Using Biometrics

    OpenAIRE

    Elisardo Gonzalez-Agulla; Jose L. Alba-Castro; Enrique Argones-Rua; Luis Anido-Rifon

    2010-01-01

    In this paper we propose a solution to obtain useful and reliable student session logs in a Learning Management System (LMS) combining current logs with biometrics-based logs that show the student behaviour during the whole learning session. The aims of our solution are to guarantee that the online student is who he/she claims to be, and also to know exactly how much time he/she spends in front of the computer reading each LMS content. Even when the proposed solution does not completely avoid...

  3. Cumulative overlap distribution function in realistic spin glasses

    Science.gov (United States)

    Billoire, A.; Maiorano, A.; Marinari, E.; Martin-Mayor, V.; Yllanes, D.

    2014-09-01

    We use a sample-dependent analysis, based on medians and quantiles, to analyze the behavior of the overlap probability distribution of the Sherrington-Kirkpatrick and 3D Edwards-Anderson models of Ising spin glasses. We find that this approach is an effective tool to distinguish between replica symmetry breaking-like and droplet-like behavior of the spin-glass phase. Our results are in agreement with a replica symmetry breaking-like behavior for the 3D Edwards-Anderson model.

  4. PIV-measured versus CFD-predicted flow dynamics in anatomically realistic cerebral aneurysm models.

    Science.gov (United States)

    Ford, Matthew D; Nikolov, Hristo N; Milner, Jaques S; Lownie, Stephen P; Demont, Edwin M; Kalata, Wojciech; Loth, Francis; Holdsworth, David W; Steinman, David A

    2008-04-01

    Computational fluid dynamics (CFD) modeling of nominally patient-specific cerebral aneurysms is increasingly being used as a research tool to further understand the development, prognosis, and treatment of brain aneurysms. We have previously developed virtual angiography to indirectly validate CFD-predicted gross flow dynamics against the routinely acquired digital subtraction angiograms. Toward a more direct validation, here we compare detailed, CFD-predicted velocity fields against those measured using particle imaging velocimetry (PIV). Two anatomically realistic flow-through phantoms, one a giant internal carotid artery (ICA) aneurysm and the other a basilar artery (BA) tip aneurysm, were constructed of a clear silicone elastomer. The phantoms were placed within a computer-controlled flow loop, programed with representative flow rate waveforms. PIV images were collected on several anterior-posterior (AP) and lateral (LAT) planes. CFD simulations were then carried out using a well-validated, in-house solver, based on micro-CT reconstructions of the geometries of the flow-through phantoms and inlet/outlet boundary conditions derived from flow rates measured during the PIV experiments. PIV and CFD results from the central AP plane of the ICA aneurysm showed a large stable vortex throughout the cardiac cycle. Complex vortex dynamics, captured by PIV and CFD, persisted throughout the cardiac cycle on the central LAT plane. Velocity vector fields showed good overall agreement. For the BA, aneurysm agreement was more compelling, with both PIV and CFD similarly resolving the dynamics of counter-rotating vortices on both AP and LAT planes. Despite the imposition of periodic flow boundary conditions for the CFD simulations, cycle-to-cycle fluctuations were evident in the BA aneurysm simulations, which agreed well, in terms of both amplitudes and spatial distributions, with cycle-to-cycle fluctuations measured by PIV in the same geometry. The overall good agreement

  5. Modelling realistic horizontal branch morphologies and their impact on spectroscopic ages of unresolved stellar systems

    Science.gov (United States)

    Percival, Susan M.; Salaris, Maurizio

    2011-04-01

    The presence of an extended blue horizontal branch (HB) in a stellar population is known to affect the age inferred from spectral fitting to stellar population synthesis models. This is due to the hot blue component which increases the strength of the Balmer lines and can make an old population look spuriously young. However, most population synthesis models still rely on theoretical isochrones, which do not include realistic modelling of extended HBs. In this work, we create detailed models for a range of old simple stellar populations (SSPs), with metallicities ranging from [Fe/H]=-1.3 to solar, to create a variety of realistic HB morphologies, from extended red clumps, to extreme blue HBs. We achieve this by utilizing stellar tracks from the BaSTI data base and implementing a different mass-loss prescription for each SSP created. This includes setting an average mass and a Gaussian spread in masses of individual stars coming on to the zero-age HB for each model, and hence resulting in different HB morphologies. We find that, for each metallicity, there is some HB morphology which maximizes Hβ, making an underlying 14-Gyr population look ˜5-6 Gyr old for the low- and intermediate-metallicity cases, and as young as 2 Gyr in the case of the solar metallicity SSP. We explore whether there are any spectral indices capable of breaking the degeneracy between an old SSP with extended blue HB and a truly young or intermediate-age SSP, and find that the Ca II index of Rose and the strength of the Mg II doublet at 2800 Å are promising candidates, in combination with Hβ and other metallicity indicators, such as Mgb and Fe5406. We also run Monte Carlo simulations to investigate the level of statistical fluctuations in the spectra of typical stellar clusters. We find that fluctuations in spectral indices are significant even for average to large globular clusters and that various spectral indices are affected in different ways, which has implications for full

  6. Realistic modeling of seismic input for megacities and large urban areas

    Science.gov (United States)

    Panza, G. F.; Unesco/Iugs/Igcp Project 414 Team

    2003-04-01

    The project addressed the problem of pre-disaster orientation: hazard prediction, risk assessment, and hazard mapping, in connection with seismic activity and man-induced vibrations. The definition of realistic seismic input has been obtained from the computation of a wide set of time histories and spectral information, corresponding to possible seismotectonic scenarios for different source and structural models. The innovative modeling technique, that constitutes the common tool to the entire project, takes into account source, propagation and local site effects. This is done using first principles of physics about wave generation and propagation in complex media, and does not require to resort to convolutive approaches, that have been proven to be quite unreliable, mainly when dealing with complex geological structures, the most interesting from the practical point of view. In fact, several techniques that have been proposed to empirically estimate the site effects using observations convolved with theoretically computed signals corresponding to simplified models, supply reliable information about the site response to non-interfering seismic phases. They are not adequate in most of the real cases, when the seismic sequel is formed by several interfering waves. The availability of realistic numerical simulations enables us to reliably estimate the amplification effects even in complex geological structures, exploiting the available geotechnical, lithological, geophysical parameters, topography of the medium, tectonic, historical, palaeoseismological data, and seismotectonic models. The realistic modeling of the ground motion is a very important base of knowledge for the preparation of groundshaking scenarios that represent a valid and economic tool for the seismic microzonation. This knowledge can be very fruitfully used by civil engineers in the design of new seismo-resistant constructions and in the reinforcement of the existing built environment, and, therefore

  7. [Developing a national health policy: a realistic ambition].

    Science.gov (United States)

    Lopez, Alain

    2012-01-01

    The current national health policy in France is almost impossible to pin down and define, spread as it is across thirty or so schemes and a hundred or so targets set by a law adopted in 2004. Yet the current legislation defines the national health policy as a standard reference for public policies developed and implemented by the Ministry of Health and associated bodies. In addition, the current policy involves little consultation and is not systematically monitored and evaluated. Developing an interdepartmental health policy combining several intervention strategies and using different regulation tools may seem like an impossible task. It may also seem somewhat imprudent when it claims to define priorities and strategies. In order to overcome these difficulties and inherent contradictions, we need to develop a policy based on three key elements (a strategy, plans and policies, and policy decentralization and devolution). However, it is not enough to merely develop a framework; it is also important to define the steering and oversight plan, the consultation process and a monitoring and evaluation system. The foundations of a policy based on these principles have already been laid. The authorities simply need to continue along the lines of recent policy developments, including the creation of regional agencies (ARS), the creation of a national steering committee, and the various public health plans developed over the last 20 years.

  8. A realistic assessment of methods for extracting gene/protein interactions from free text

    Directory of Open Access Journals (Sweden)

    Shepherd Adrian J

    2009-07-01

    Full Text Available Abstract Background The automated extraction of gene and/or protein interactions from the literature is one of the most important targets of biomedical text mining research. In this paper we present a realistic evaluation of gene/protein interaction mining relevant to potential non-specialist users. Hence we have specifically avoided methods that are complex to install or require reimplementation, and we coupled our chosen extraction methods with a state-of-the-art biomedical named entity tagger. Results Our results show: that performance across different evaluation corpora is extremely variable; that the use of tagged (as opposed to gold standard gene and protein names has a significant impact on performance, with a drop in F-score of over 20 percentage points being commonplace; and that a simple keyword-based benchmark algorithm when coupled with a named entity tagger outperforms two of the tools most widely used to extract gene/protein interactions. Conclusion In terms of availability, ease of use and performance, the potential non-specialist user community interested in automatically extracting gene and/or protein interactions from free text is poorly served by current tools and systems. The public release of extraction tools that are easy to install and use, and that achieve state-of-art levels of performance should be treated as a high priority by the biomedical text mining community.

  9. Turbulent transport measurements in a cold model of GT-burner at realistic flow rates

    Directory of Open Access Journals (Sweden)

    Gobyzov Oleg

    2016-01-01

    Full Text Available In the present work simultaneous velocity field and passive admixture concentration field measurements at realistic flow-rates conditions in a non-reacting flow in a model of combustion chamber with an industrial mixing device are reported. In the experiments for safety reasons the real fuel (natural gas was replaced with neon gas to simulate stratification in a strongly swirling flow. Measurements were performed by means of planar laser-induced fluorescence (PLIF and particle image velocimetry technique (PIV at Reynolds number, based on the mean flow rate and nozzle diameter, ≈300 000. Details on experimental technique, features of the experimental setup, images and data preprocessing procedures and results of performed measurements are given in the paper. In addition to the raw velocity and admixture concentration data in-depth evaluation approaches aimed for estimation of turbulent kinetic energy (TKE components, assessment of turbulent Schmidt number and analysis of the gradient closure hypothesis from experimental data are presented in the paper.

  10. Toward Establishing a Realistic Benchmark for Airframe Noise Research: Issues and Challenges

    Science.gov (United States)

    Khorrami, Mehdi R.

    2010-01-01

    The availability of realistic benchmark configurations is essential to enable the validation of current Computational Aeroacoustic (CAA) methodologies and to further the development of new ideas and concepts that will foster the technologies of the next generation of CAA tools. The selection of a real-world configuration, the subsequent design and fabrication of an appropriate model for testing, and the acquisition of the necessarily comprehensive aeroacoustic data base are critical steps that demand great care and attention. In this paper, a brief account of the nose landing-gear configuration, being proposed jointly by NASA and the Gulfstream Aerospace Company as an airframe noise benchmark, is provided. The underlying thought processes and the resulting building block steps that were taken during the development of this benchmark case are given. Resolution of critical, yet conflicting issues is discussed - the desire to maintain geometric fidelity versus model modifications required to accommodate instrumentation; balancing model scale size versus Reynolds number effects; and time, cost, and facility availability versus important parameters like surface finish and installation effects. The decisions taken during the experimental phase of a study can significantly affect the ability of a CAA calculation to reproduce the prevalent flow conditions and associated measurements. For the nose landing gear, the most critical of such issues are highlighted and the compromises made to resolve them are discussed. The results of these compromises will be summarized by examining the positive attributes and shortcomings of this particular benchmark case.

  11. Feasibility study for a realistic training dedicated to radiological protection improvement

    Science.gov (United States)

    Courageot, Estelle; Reinald, Kutschera; Gaillard-Lecanu, Emmanuelle; Sylvie, Jahan; Riedel, Alexandre; Therache, Benjamin

    2014-06-01

    Any personnel involved in activities within the controlled area of a nuclear facility must be provided with appropriate radiological protection training. An evident purpose of this training is to know the regulation dedicated to workplaces where ionizing radiation may be present, in order to properly carry out the radiation monitoring, to use suitable protective equipments and to behave correctly if unexpected working conditions happen. A major difficulty of this training consist in having the most realistic reading from the monitoring devices for a given exposure situation, but without using real radioactive sources. A new approach is developed at EDF R&D for radiological protection training. This approach combines different technologies, in an environment representative of the workplace but geographically separated from the nuclear power plant: a training area representative of a workplace, a Man Machine Interface used by the trainer to define the source configuration and the training scenario, a geolocalization system, fictive radiation monitoring devices and a particle transport code able to calculate in real time the dose map due to the virtual sources. In a first approach, our real-time particles transport code, called Moderato, used only an attenuation low in straight line. To improve the realism further, we would like to switch a code based on the Monte Carlo transport of particles method like Geant 4 or MCNPX instead of Moderato. The aim of our study is the evaluation of the code in our application, in particular, the possibility to keep a real time response of our architecture.

  12. Development and implementation of a nutrition intervention programme in North West Pakistan: a realist framework.

    Science.gov (United States)

    Lhussier, Monique; Bangash, Sonia; Dykes, Fiona; Zaman, Mukhtiar; Lowe, Nicola M

    2012-12-01

    Maternal and infant malnutrition is prevalent in rural regions of NW Pakistan. This article reports on the use of a combination of a realist Context-Mechanism-Outcome framework and participatory appraisal methods to facilitate the development of a locally sensitive and responsive nutritional intervention programme. Data were gathered through a series of focus group (FG) discussions with local lady health workers, as well as pregnant and breastfeeding women attending an Emergency Field Hospital in North West Pakistan between May 2008 and March 2009. A nutrition intervention programme was implemented that involved cookery demonstration kitchens and free food supplements, coupled with nutrition and healthcare information and advice for pregnant and breastfeeding women. Subsequent FG discussions revealed that the programme had a positive impact on knowledge gained by women in the community and generated an openness to receiving and spreading knowledge. The framework, which rested on the use of a double feedback loop, involving local women, lady health workers, local researchers and UK-based researchers, has enabled not only the establishment of the programme, but has also given the local team the tools to apply for, and gain, further funding for the development of nutrition support services. The development of such methodological tools, which empower local researchers and service providers (wherever located) to operationalize local knowledge and assess interventions, is particularly relevant in international financially-constrained contexts.

  13. Generic Simulator Environment for Realistic Simulation - Autonomous Entity Proof and Emotion in Decision Making

    Directory of Open Access Journals (Sweden)

    Mickaël Camus

    2004-10-01

    Full Text Available Simulation is usually used as an evaluation and testing system. Many sectors are concerned such as EUROPEAN SPACE AGENCY or the EUROPEAN DEFENCE. It is important to make sure that the project is error-free in order to continue it. The difficulty is to develop a realistic environment for the simulation and the execution of a scenario. This paper presents PALOMA, a Generic Simulator Environment. This project is based essantially on the Chaos Theory and Complex Systems to create and direct an environment for a simulation. An important point is the generic aspect. PALOMA will be able to create an environment for different sectors (Aero-space, Biology, Mathematic, .... PALOMA includes six components : the Simulation Engine, the Direction Module, the Environment Generator, the Natural Behavior Restriction, the Communication API and the User API. Three languages are used to develop this simulator. SCHEME for the Direction language, C/C++ for the development of modules and OZ/MOZART for the heart of PALOMA.

  14. Simulating realistic disk galaxies with a novel sub-resolution ISM model

    CERN Document Server

    Murante, Giuseppe; Borgani, Stefano; Tornatore, Luca; Dolag, Klaus

    2014-01-01

    We present results of cosmological simulations of disk galaxies carried out with the GADGET-3 TreePM+SPH code, where star formation and stellar feedback are described using our MUlti Phase Particle Integrator (MUPPI) model. This description is based on simple multi-phase model of the interstellar medium at unresolved scales, where mass and energy flows among the components are explicitly followed by solving a system of ordinary differential equations. Thermal energy from SNe is injected into the local hot phase, so as to avoid that it is promptly radiated away. A kinetic feedback prescription generates the massive outflows needed to avoid the over-production of stars. We use two sets of zoomed-in initial conditions of isolated cosmological halos with masses (2-3) * 10^{12} Msun, both available at several resolution levels. In all cases we obtain spiral galaxies with small bulge-over-total stellar mass ratios (B/T \\approx 0.2), extended stellar and gas disks, flat rotation curves and realistic values of stella...

  15. Parameter estimation for binary neutron-star coalescences with realistic noise during the Advanced LIGO era

    CERN Document Server

    Berry, Christopher P L; Middleton, Hannah; Singer, Leo P; Urban, Alex L; Vecchio, Alberto; Vitale, Salvatore; Cannon, Kipp; Farr, Ben; Farr, Will M; Graff, Philip B; Hanna, Chad; Haster, Carl-Johan; Mohapatra, Satya; Pankow, Chris; Price, Larry R; Sidery, Trevor; Veitch, John

    2014-01-01

    Advanced ground-based gravitational-wave (GW) detectors begin operation imminently. Their intended goal is not only to make the first direct detection of GWs, but also to make inferences about the source systems. Binary neutron-star mergers are among the most promising sources. We investigate the performance of the parameter-estimation pipeline that will be used during the first observing run of the Advanced Laser Interferometer Gravitational-wave Observatory (aLIGO) in 2015: we concentrate on the ability to reconstruct the source location on the sky, but also consider the ability to measure masses and the distance. Accurate, rapid sky-localization is necessary to alert electromagnetic (EM) observatories so that they can perform follow-up searches for counterpart transient events. We consider parameter-estimation accuracy in the presence of realistic, non-Gaussian noise. We find that the character of the noise makes negligible difference to the parameter-estimation performance. The source luminosity distance ...

  16. Towards Realistic Vehicular Network Modeling Using Planet-scale Public Webcams

    CERN Document Server

    Thakur, Gautam S; Ketabdar, Hamed; Helmy, Ahmed

    2011-01-01

    Realistic modeling of vehicular mobility has been particularly challenging due to a lack of large libraries of measurements in the research community. In this paper we introduce a novel method for large-scale monitoring, analysis, and identification of spatio-temporal models for vehicular mobility using the freely available online webcams in cities across the globe. We collect vehicular mobility traces from 2,700 traffic webcams in 10 different cities for several months and generate a mobility dataset of 7.5 Terabytes consisting of 125 million of images. To the best of our knowl- edge, this is the largest data set ever used in such study. To process and analyze this data, we propose an efficient and scalable algorithm to estimate traffic density based on background image subtraction. Initial results show that at least 82% of individual cameras with less than 5% deviation from four cities follow Loglogistic distribution and also 94% cameras from Toronto follow gamma distribution. The aggregate results from eac...

  17. Optimized Load Shedding Approach for Grid-Connected DC Microgrid Systems under Realistic Constraints

    Directory of Open Access Journals (Sweden)

    Leonardo Trigueiro dos Santos

    2016-12-01

    Full Text Available The microgrid system is an answer to the necessity of increasing renewable energy penetration and also works as a bridge for the future smart grid. Considering the microgrid system applied to commercial building equipped with photovoltaic sources, the usage of a DC microgrid architecture can improve the efficiency of the system, while ensuring robustness and reducing the overall energy cost. Given the power grid stress and the intermittency of the DC microgrid power production, backup power provision and load shedding operations may occur to stabilize the DC bus voltage. Based on the knapsack problem formulation, this paper presents a realistic optimization approach to shedding a building’s appliances, considering the priority of each appliance, and also considering a minimum amount of load that must be attended. The problem is solved by mixed integer linear programming and the CPLEX solver. The proposed architecture ensures critical load supply and voltage stabilization through the real-time operation of the operational algorithm allowing the load shedding optimization approach to be applied without compromising the robustness of the system. The results obtained by simulation prove that the DC microgrid is able to supply the building power network by applying the load shedding optimization program to overcome, mainly, the renewable energy intermittency.

  18. Using coronal seismology to estimate the magnetic field strength in a realistic coronal model

    CERN Document Server

    Chen, Feng

    2015-01-01

    Coronal seismology is extensively used to estimate properties of the corona, e.g. the coronal magnetic field strength are derived from oscillations observed in coronal loops. We present a three-dimensional coronal simulation including a realistic energy balance in which we observe oscillations of a loop in synthesised coronal emission. We use these results to test the inversions based on coronal seismology. From the simulation of the corona above an active region we synthesise extreme ultraviolet (EUV) emission from the model corona. From this we derive maps of line intensity and Doppler shift providing synthetic data in the same format as obtained from observations. We fit the (Doppler) oscillation of the loop in the same fashion as done for observations to derive the oscillation period and damping time. The loop oscillation seen in our model is similar to imaging and spectroscopic observations of the Sun. The velocity disturbance of the kink oscillation shows an oscillation period of 52.5s and a damping tim...

  19. Multiscale modelling as a tool to prescribe realistic boundary conditions for the study of surgical procedures.

    Science.gov (United States)

    Laganà, K; Dubini, G; Migliavacca, F; Pietrabissa, R; Pennati, G; Veneziani, A; Quarteroni, A

    2002-01-01

    This work was motivated by the problems of analysing detailed 3D models of vascular districts with complex anatomy. It suggests an approach to prescribing realistic boundary conditions to use in order to obtain information on local as well as global haemodynamics. A method was developed which simultaneously solves Navier-Stokes equations for local information and a non-linear system of ordinary differential equations for global information. This is based on the principle that an anatomically detailed 3D model of a cardiovascular district can be achieved by using the finite element method. In turn the finite element method requires a specific boundary condition set. The approach outlined in this work is to include the system of ordinary differential equations in the boundary condition set. Such a multiscale approach was first applied to two controls: (i) a 3D model of a straight tube in a simple hydraulic network and (ii) a 3D model of a straight coronary vessel in a lumped-parameter model of the cardiovascular system. The results obtained are very close to the solutions available for the pipe geometry. This paper also presents preliminary results from the application of the methodology to a particular haemodynamic problem: namely the fluid dynamics of a systemic-to-pulmonary shunt in paediatric cardiac surgery.

  20. Photocatalytic elimination of indoor air biological and chemical pollution in realistic conditions.

    Science.gov (United States)

    Sánchez, Benigno; Sánchez-Muñoz, Marta; Muñoz-Vicente, María; Cobas, Guillermo; Portela, Raquel; Suárez, Silvia; González, Aldo E; Rodríguez, Nuria; Amils, Ricardo

    2012-05-01

    The photocatalytic elimination of microorganisms from indoor air in realistic conditions and the feasibility of simultaneous elimination of chemical contaminants have been studied at laboratory scale. Transparent polymeric monoliths have been coated with sol-gel TiO(2) films and used as photocatalyst to treat real indoor air in a laboratory-scale single-step annular photocatalytic reactor. The analytical techniques used to characterize the air quality and analyze the results of the photocatalytic tests were: colony counting, microscopy and PCR with subsequent sequencing for microbial quantification and identification; automated thermal desorption coupled to gas chromatography with mass spectrometry detection for chemical analysis. The first experiments performed proved that photocatalysis based on UVA-irradiated TiO(2) for the reduction of the concentration of bacteria in the air could compete with the conventional photolytic treatment with UVC radiation, more expensive and hazardous. Simultaneously to the disinfection, the concentration of volatile organic compounds was greatly reduced, which adds value to this technology for real applications. The fungal colony number was not apparently modified.

  1. Anatomy, technology, art, and culture: toward a realistic perspective of the brain.

    Science.gov (United States)

    Cavalcanti, Daniel D; Feindel, William; Goodrich, James T; Dagi, T Forcht; Prestigiacomo, Charles J; Preul, Mark C

    2009-09-01

    In the 15th century, brain illustration began to change from a schematic system that involved scant objective rendering of the brain, to accurate depictions based on anatomical dissections that demanded significant artistic talent. Notable examples of this innovation are the drawings of Leonardo da Vinci (1498-1504), Andreas Vesalius' association with the bottega of Titian to produce the drawings of Vesalius' De humani corporis fabrica (1543), and Christopher Wren's illustrations for Thomas Willis' Cerebri Anatome (1664). These works appeared during the Renaissance and Age of Enlightenment, when advances in brain imaging, or really brain rendering, reflected not only the abilities and dedications of the artists, but also the influences of important cultural and scientific factors. Anatomy and human dissection became popular social phenomena as well as scholarly pursuits, linked with the world of the fine arts. The working philosophy of these artists involved active participation in both anatomical study and illustration, and the belief that their discoveries of the natural world could best be communicated by rendering them in objective form (that is, with realistic perspective). From their studies emerged the beginning of contemporary brain imaging. In this article, the authors examine how the brain began to be imaged in realism within a cultural and scientific milieu that witnessed the emergence of anatomical dissection, the geometry of linear perspective, and the closer confluence of art and science.

  2. D Visualization and Photo-Realistic Reconstruction of the Great Temple of Bel

    Science.gov (United States)

    Denker, A.

    2017-02-01

    The Great Temple of Bel in Palmyra was a unique edifice which had blended the well established lines of Greco-Roman architecture with the art and taste of the Orient. With the gilded bronze capitals of its 41 Corinthian columns it was the product of enormous effort and budget. It was the gem of a remarkable epoch of wealthy Palmyra and mighty Roma. With its splendidly decorated adyta ceilings it became a source of inspiration and imagination for Western architecture and decorative arts. While continuing to captivate the World, it was leveled and vanished as a grim result of conflict based vandalism. The aim of this work is to piece together this, the most eloquent and stupendous monument of the Roman East, from its ruins and reconstruct it as it was once extant. Its loss is irreplacable, but its photo-realistic reconstruction can offer some solace by waking the memories of the great temple as in the past. The lost reality of the Great Temple of Bel is revived here by digitally constructing its "ghost images".

  3. Realistic Measurement of Student Attendance in LMS Using Biometrics

    Directory of Open Access Journals (Sweden)

    Elisardo Gonzalez-Agulla

    2010-10-01

    Full Text Available In this paper we propose a solution to obtain useful and reliable student session logs in a Learning Management System (LMS combining current logs with biometrics-based logs that show the student behaviour during the whole learning session. The aims of our solution are to guarantee that the online student is who he/she claims to be, and also to know exactly how much time he/she spends in front of the computer reading each LMS content. Even when the proposed solution does not completely avoid cheating, the use of biometric data during authentication and face tracking provides additional help to validate student performance during learning sessions. In this way it is possible to improve security for specific contents, to gain feedback of the student effort and to check the actual time spent in learning.

  4. Optimal working conditions for thermoelectric generators with realistic thermal coupling

    CERN Document Server

    Apertet, Y; Glavatskaya, O; Goupil, C; Lecoeur, P

    2011-01-01

    We study how maximum output power can be obtained from a thermoelectric generator(TEG) with nonideal heat exchangers. We demonstrate with an analytic approach based on a force-flux formalism that the sole improvement of the intrinsic characteristics of thermoelectric modules including the enhancement of the figure of merit is of limited interest: the constraints imposed by the working conditions of the TEG must be considered on the same footing. Introducing an effective thermal conductance we derive the conditions which permit maximization of both efficiency and power production of the TEG dissipatively coupled to heat reservoirs. Thermal impedance matching must be accounted for as well as electrical impedance matching in order to maximize the output power. Our calculations also show that the thermal impedance does not only depend on the thermal conductivity at zero electrical current: it also depends on the TEG figure of merit. Our analysis thus yields both electrical and thermal conditions permitting optima...

  5. Dynamical Decoupling in the Presence of Realistic Pulse Errors

    CERN Document Server

    Tyryshkin, A M; Zhang, Wenxian; Haller, E E; Ager, J; Dobrovitski, V V; Lyon, S A

    2010-01-01

    One of the most significant hurdles to be overcome on the path to practical quantum information processors is dealing with quantum errors. Dynamical decoupling is a particularly promising approach that complements conventional quantum error correction by eliminating some correlated errors without the overhead of additional qubits. In practice, the control pulses used for decoupling are imperfect and thus introduce errors which can accumulate after many pulses. These instrumental errors can destroy the quantum state. Here we examine several dynamical decoupling sequences, and their concatenated variants, using electron spin resonance of donor electron spins in a $^{28}$Si crystal. All of the sequences cancel phase noise arising from slowly fluctuating magnetic fields in our spectrometer, but only those sequences based upon alternating $\\pi$-rotations about the X- and Y-axes in the rotating frame (XYXY sequences) demonstrate the ability to store an arbitrary quantum state. By comparing the experimental results ...

  6. Do drivers have a realistic view of their driving ability?

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    The Driver Behavior Questionnaire (DBQ) and the Driver Skill Inventory (DSI) are two of the most frequently used measures of driving style and driving skill. The motivation behind the present study was to test drivers’ insight into their own driving ability based on a combined use of the DBQ......, annual mileage and accident involvement. 3908 drivers aged 18–84 participated in the survey. The results suggested that the drivers have good insight into their own driving ability, as the driving skill level mirrored the frequency of aberrant driving behaviors. K-means cluster analysis revealed four...... and the DSI. Moreover, the joint use of the two instruments was applied to identify sub-groups of drivers that differ in their potential danger in traffic, as well as to test for heterogeneity across the population, namely whether the sub-groups of drivers differed in characteristics such as age, gender...

  7. Feasibility of BCI Control in a Realistic Smart Home Environment

    Directory of Open Access Journals (Sweden)

    Nataliya Kosmyna

    2016-08-01

    Full Text Available Smart homes have been an active area of research, however despite considerable investment, they are not yet a reality for end-users. Moreover, there are still accessibility challenges for the elderly or the disabled, two of the main potential targets for home automation. In this exploratory study we design a control mechanism for smart homes based on Brain Computer Interfaces (BCI and apply it in the Domus smart home platform in order to evaluate the potential interest of users about BCIs at home. We enable users to control lighting, a TV set, a coffee machine and the shutters of the smart home. We evaluate the performance (accuracy, interaction time, usability and feasibility (USE questionnaire on 12 healthy subjects and 2 disabled subjects. We find that healthy subjects achieve 77% task accuracy. However, disabled subjects achieved a better accuracy (81% compared to 77%.

  8. Feasibility of BCI Control in a Realistic Smart Home Environment.

    Science.gov (United States)

    Kosmyna, Nataliya; Tarpin-Bernard, Franck; Bonnefond, Nicolas; Rivet, Bertrand

    2016-01-01

    Smart homes have been an active area of research, however despite considerable investment, they are not yet a reality for end-users. Moreover, there are still accessibility challenges for the elderly or the disabled, two of the main potential targets for home automation. In this exploratory study we design a control mechanism for smart homes based on Brain Computer Interfaces (BCI) and apply it in the "Domus" smart home platform in order to evaluate the potential interest of users about BCIs at home. We enable users to control lighting, a TV set, a coffee machine and the shutters of the smart home. We evaluate the performance (accuracy, interaction time), usability and feasibility (USE questionnaire) on 12 healthy subjects and 2 disabled subjects. We find that healthy subjects achieve 77% task accuracy. However, disabled subjects achieved a better accuracy (81% compared to 77%).

  9. Feasibility of BCI Control in a Realistic Smart Home Environment

    Science.gov (United States)

    Kosmyna, Nataliya; Tarpin-Bernard, Franck; Bonnefond, Nicolas; Rivet, Bertrand

    2016-01-01

    Smart homes have been an active area of research, however despite considerable investment, they are not yet a reality for end-users. Moreover, there are still accessibility challenges for the elderly or the disabled, two of the main potential targets for home automation. In this exploratory study we design a control mechanism for smart homes based on Brain Computer Interfaces (BCI) and apply it in the “Domus”1 smart home platform in order to evaluate the potential interest of users about BCIs at home. We enable users to control lighting, a TV set, a coffee machine and the shutters of the smart home. We evaluate the performance (accuracy, interaction time), usability and feasibility (USE questionnaire) on 12 healthy subjects and 2 disabled subjects. We find that healthy subjects achieve 77% task accuracy. However, disabled subjects achieved a better accuracy (81% compared to 77%). PMID:27616986

  10. TextGen:a realistic text data content generation method for modern storage system benchmarks

    Institute of Scientific and Technical Information of China (English)

    Long-xiang WANG; Xiao-she DONG; Xing-jun ZHANG; Yin-feng WANG; Tao JU; Guo-fu FENG

    2016-01-01

    Modern storage systems incorporate data compressors to improve their performance and capacity. As a result, data content can significantly influence the result of a storage system benchmark. Because real-world proprietary datasets are too large to be copied onto a test storage system, and most data cannot be shared due to privacy issues, a benchmark needs to generate data synthetically. To ensure that the result is accurate, it is necessary to generate data content based on the characterization of real-world data properties that influence the storage system performance during the execution of a benchmark. The existing approach, called SDGen, cannot guarantee that the benchmark result is accurate in storage systems that have built-in word-based compressors. The reason is that SDGen characterizes the properties that influence compression performance only at the byte level, and no properties are characterized at the word level. To address this problem, we present TextGen, a realistic text data content generation method for modern storage system benchmarks. TextGen builds the word corpus by segmenting real-world text datasets, and creates a word-frequency distribution by counting each word in the corpus. To improve data generation performance, the word-frequency distribution is fitted to a lognormal distribution by maximum likelihood estimation. The Monte Carlo approach is used to generate synthetic data. The running time of TextGen generation depends only on the expected data size, which means that the time complexity of TextGen isO(n). To evaluate TextGen, four real-world datasets were used to perform an experiment. The experimental results show that, compared with SDGen, the compression performance and compression ratio of the datasets generated by TextGen deviate less from real-world datasets when end-tagged dense code, a representative of word-based compressors, is evaluated.

  11. Security of Quantum Key Distribution with Realistic Devices

    CERN Document Server

    Ma, X

    2005-01-01

    We simulate quantum key distribution (QKD) experimental setups and give out some improvement for QKD procedures. A new data post-processing protocol is introduced, mainly including error correction and privacy amplification. This protocol combines the ideas of GLLP and the decoy states, which essentially only requires to turn up and down the source power. We propose a practical way to perform the decoy state method, which mainly follows the idea of Lo's decoy state. A new data post-processing protocol is then developed for the QKD scheme with the decoy state. We first study the optimal expected photon number mu of the source for the improved QKD scheme. We get the new optimal mu=O(1) comparing with former mu=O(eta), where eta is the overall transmission efficiency. With this protocol, we can then improve the key generation rate from quadratic of transmission efficiency O(eta2) to O(eta). Based on the recent experimental setup, we obtain the maximum secure transmission distance of over 140 km.

  12. Realistic Approach of the Relations of Uncertainty of Heisenberg

    Directory of Open Access Journals (Sweden)

    Paul E. Sterian

    2013-01-01

    Full Text Available Due to the requirements of the principle of causality in the theory of relativity, one cannot make a device for the simultaneous measuring of the canonical conjugate variables in the conjugate Fourier spaces. Instead of admitting that a particle’s position and its conjugate momentum cannot be accurately measured at the same time, we consider the only probabilities which can be determined when working at subatomic level to be valid. On the other hand, based on Schwinger's action principle and using the quadridimensional form of the unitary transformation generator function of the quantum operators in the paper, the general form of the evolution equation for these operators is established. In the nonrelativistic case one obtains the Heisenberg's type evolution equations which can be particularized to derive Heisenberg's uncertainty relations. The analysis of the uncertainty relations as implicit evolution equations allows us to put into evidence the intrinsic nature of the correlation expressed by these equations in straight relations with the measuring process. The independence of the quantisation postulate from the causal evolution postulate of quantum mechanics is also put into discussion.

  13. Is modulating virus virulence by induced systemic resistance realistic?

    Science.gov (United States)

    Faoro, Franco; Gozzo, Franco

    2015-05-01

    Induction of plant resistance, either achieved by chemicals (systemic acquired resistance, SAR) or by rhizobacteria (induced systemic resistance, ISR) is a possible and/or complementary alternative to manage virus infections in crops. SAR mechanisms operating against viruses are diverse, depending on the pathosystem, and may inhibit virus replication as well as cell-to-cell and long-distance movement. Inhibition is often mediated by salicylic acid with the involvement of alternative oxidase and reactive oxygen species. However, salicylate may also stimulate a separate downstream pathway, leading to the induction of an additional mechanism, based on RNA-dependent RNA polymerase 1-mediated RNA silencing. Thus, SAR and RNA silencing would closely cooperate in the defence against virus infection. Despite tremendous recent progress in the knowledge of SAR mechanisms, only a few compounds, including benzothiadiazole and chitosan have been shown to reduce the severity of systemic virus disease in controlled environment and, more modestly, in open field. Finally, ISR induction, has proved to be a promising strategy to control virus disease, particularly by seed bacterization with a mixture of plant growth-promoting rhizobacteria. However, the use of any of these treatments should be integrated with cultivation practices that reduce vector pressure by the use of insecticides, or by Bt crops.

  14. Ultra-realistic imaging: a new beginning for display holography

    Science.gov (United States)

    Bjelkhagen, Hans I.; Brotherton-Ratcliffe, David

    2014-02-01

    Recent improvements in key foundation technologies are set to potentially transform the field of Display Holography. In particular new recording systems, based on recent DPSS and semiconductor lasers combined with novel recording materials and processing, have now demonstrated full-color analogue holograms of both lower noise and higher spectral accuracy. Progress in illumination technology is leading to a further major reduction in display noise and to a significant increase of the clear image depth and brightness of such holograms. So too, recent progress in 1-step Direct-Write Digital Holography (DWDH) now opens the way to the creation of High Virtual Volume Displays (HVV) - large format full-parallax DWDH reflection holograms having fundamentally larger clear image depths. In a certain fashion HVV displays can be thought of as providing a high quality full-color digital equivalent to the large-format laser-illuminated transmission holograms of the sixties and seventies. Back then, the advent of such holograms led to much optimism for display holography in the market. However, problems with laser illumination, their monochromatic analogue nature and image noise are well cited as being responsible for their failure in reality. Is there reason for believing that the latest technology improvements will make the mark this time around? This paper argues that indeed there is.

  15. DC electrophoresis and viscosity of realistic salt-free concentrated suspensions: non-equilibrium dissociation-association processes.

    Science.gov (United States)

    Ruiz-Reina, Emilio; Carrique, Félix; Lechuga, Luis

    2014-03-01

    Most of the suspensions usually found in industrial applications are concentrated, aqueous and in contact with the atmospheric CO2. The case of suspensions with a high concentration of added salt is relatively well understood and has been considered in many studies. In this work we are concerned with the case of concentrated suspensions that have no ions different than: (1) those stemming from the charged colloidal particles (the added counterions, that counterbalance their surface charge); (2) the H(+) and OH(-) ions from water dissociation, and (3) the ions generated by the atmospheric CO2 contamination. We call this kind of systems "realistic salt-free suspensions". We show some theoretical results about the electrophoretic mobility of a colloidal particle and the electroviscous effect of realistic salt-free concentrated suspensions. The theoretical framework is based on a cell model that accounts for particle-particle interactions in concentrated suspensions, which has been successfully applied to many different phenomena in concentrated suspensions. On the other hand, the water dissociation and CO2 contamination can be described following two different levels of approximation: (a) by local equilibrium mass-action equations, because it is supposed that the reactions are so fast that chemical equilibrium is attained everywhere in the suspension, or (b) by non-equilibrium dissociation-association kinetic equations, because it is considered that some reactions are not rapid enough to ensure local chemical equilibrium. Both approaches give rise to different results in the range from dilute to semidilute suspensions, causing possible discrepancies when comparing standard theories and experiments concerning transport properties of realistic salt-free suspensions.

  16. Comparison of student's learning achievement through realistic mathematics education (RME) approach and problem solving approach on grade VII

    Science.gov (United States)

    Ilyas, Muhammad; Salwah

    2017-02-01

    The type of this research was experiment. The purpose of this study was to determine the difference and the quality of student's learning achievement between students who obtained learning through Realistic Mathematics Education (RME) approach and students who obtained learning through problem solving approach. This study was a quasi-experimental research with non-equivalent experiment group design. The population of this study was all students of grade VII in one of junior high school in Palopo, in the second semester of academic year 2015/2016. Two classes were selected purposively as sample of research that was: year VII-5 as many as 28 students were selected as experiment group I and VII-6 as many as 23 students were selected as experiment group II. Treatment that used in the experiment group I was learning by RME Approach, whereas in the experiment group II by problem solving approach. Technique of data collection in this study gave pretest and posttest to students. The analysis used in this research was an analysis of descriptive statistics and analysis of inferential statistics using t-test. Based on the analysis of descriptive statistics, it can be concluded that the average score of students' mathematics learning after taught using problem solving approach was similar to the average results of students' mathematics learning after taught using realistic mathematics education (RME) approach, which are both at the high category. In addition, It can also be concluded that; (1) there was no difference in the results of students' mathematics learning taught using realistic mathematics education (RME) approach and students who taught using problem solving approach, (2) quality of learning achievement of students who received RME approach and problem solving approach learning was same, which was at the high category.

  17. Simulation of stent deployment in a realistic human coronary artery

    Directory of Open Access Journals (Sweden)

    van der Steen Anton FW

    2008-08-01

    Full Text Available Abstract Background The process of restenosis after a stenting procedure is related to local biomechanical environment. Arterial wall stresses caused by the interaction of the stent with the vascular wall and possibly stress induced stent strut fracture are two important parameters. The knowledge of these parameters after stent deployment in a patient derived 3D reconstruction of a diseased coronary artery might give insights in the understanding of the process of restenosis. Methods 3D reconstruction of a mildly stenosed coronary artery was carried out based on a combination of biplane angiography and intravascular ultrasound. Finite element method computations were performed to simulate the deployment of a stent inside the reconstructed coronary artery model at inflation pressure of 1.0 MPa. Strut thickness of the stent was varied to investigate stresses in the stent and the vessel wall. Results Deformed configurations, pressure-lumen area relationship and stress distribution in the arterial wall and stent struts were studied. The simulations show how the stent pushes the arterial wall towards the outside allowing the expansion of the occluded artery. Higher stresses in the arterial wall are present behind the stent struts and in regions where the arterial wall was thin. Values of 200 MPa for the peak stresses in the stent strut were detected near the connecting parts between the stent struts, and they were only just below the fatigue stress. Decreasing strut thickness might reduce arterial damage without increasing stresses in the struts significantly. Conclusion The method presented in this paper can be used to predict stresses in the stent struts and the vessel wall, and thus evaluate whether a specific stent design is optimal for a specific patient.

  18. The ontological indifference: A realist reading of Kant and Hegel

    Directory of Open Access Journals (Sweden)

    Simoniti Jure

    2015-01-01

    Full Text Available The article challenges the first premise of „speculative realism“, according to which, with Kant, the contact with the outside world was lost. Instead, it will be shown that the possibility of realism received its major impulse from two grand figures of German Idealism, from Kant as a precursor of the Romantic period and from Hegel as its, albeit critical, philosophical culmination. Based on three possible relations of knowledge to its outside, three ontologies will be distinguished, the ontology of immediacy, stretching from rationalists to the last empiricists, Kant’s ontology of totalization, and, finally, Hegel’s „ontology of release“ or „de-totalization“. As opposed to Descartes’s thing being constantly doubted in its existence, as opposed to Malebranche’s occasion being invariably induced by God, as opposed to Leibniz’s monad being an immediate embodiment of an idea, as opposed to Berkeley’s object vanishing when not perceived, and as opposed to Hume’s world lacking necessity, Kant philosophically warranted a world that does not have to be perpetually verified and can, hence, exist devoid of ideas produced by God and outside the constancy of the human gaze. Kant secured the normal and necessary existence of the world behind our backs and procured us with the common-sense normality of the world, but it was only Hegel’s absolute subjectivism that granted us the first glimpses into the radical meaninglesness of the facticity. It was not until Hegel’s logic of indifference of the notion to its immediate content that an egress of the circle of Kant’s totalization was made possible.

  19. Species traits outweigh nested structure in driving the effects of realistic biodiversity loss on productivity.

    Science.gov (United States)

    Wolfi, Amelia A; Zavaleta, Erika S

    2015-01-01

    While most studies of the relationship between biodiversity and ecosystem functioning have examined randomized diversity losses, several recent experiments have employed nested, realistic designs and found that realistic species losses had larger consequences than random losses for ecosystem functioning. Progressive, realistic, biodiversity losses are generally strongly nested, but this nestedness is a potentially confounding effect. Here, we address whether nonrandom trait loss or degree of nestedness drives the relationship between diversity and productivity in a realistic biodiversity-loss experiment. We isolated the effect of nestedness through post hoc analyses of data from an experimental biodiversity manipulation in a California serpentine grassland. We found that the order in which plant traits are lost as diversity declines influences the diversity-productivity relationship more than the degree of nestedness does. Understanding the relationship between the expected order of species loss and functional traits is becoming increasingly important in the face of ongoing biodiversity loss worldwide. Our findings illustrate the importance of species composition and the order of species loss, rather than nestedness per se, for understanding the mechanisms underlying the effects of realistic species losses on ecosystem functioning.

  20. Putting theory to the test: which regulatory mechanisms can drive realistic growth of a root?

    Directory of Open Access Journals (Sweden)

    Dirk De Vos

    2014-10-01

    Full Text Available In recent years there has been a strong development of computational approaches to mechanistically understand organ growth regulation in plants. In this study, simulation methods were used to explore which regulatory mechanisms can lead to realistic output at the cell and whole organ scale and which other possibilities must be discarded as they result in cellular patterns and kinematic characteristics that are not consistent with experimental observations for the Arabidopsis thaliana primary root. To aid in this analysis, a 'Uniform Longitudinal Strain Rule' (ULSR was formulated as a necessary condition for stable, unidirectional, symplastic growth. Our simulations indicate that symplastic structures are robust to differences in longitudinal strain rates along the growth axis only if these differences are small and short-lived. Whereas simple cell-autonomous regulatory rules based on counters and timers can produce stable growth, it was found that steady developmental zones and smooth transitions in cell lengths are not feasible. By introducing spatial cues into growth regulation, those inadequacies could be avoided and experimental data could be faithfully reproduced. Nevertheless, a root growth model based on previous polar auxin-transport mechanisms violates the proposed ULSR due to the presence of lateral gradients. Models with layer-specific regulation or layer-driven growth offer potential solutions. Alternatively, a model representing the known cross-talk between auxin, as the cell proliferation promoting factor, and cytokinin, as the cell differentiation promoting factor, predicts the effect of hormone-perturbations on meristem size. By down-regulating PIN-mediated transport through the transcription factor SHY2, cytokinin effectively flattens the lateral auxin gradient, at the basal boundary of the division zone, (thereby imposing the ULSR to signal the exit of proliferation and start of elongation. This model exploration underlines the

  1. Putting theory to the test: which regulatory mechanisms can drive realistic growth of a root?

    Science.gov (United States)

    De Vos, Dirk; Vissenberg, Kris; Broeckhove, Jan; Beemster, Gerrit T S

    2014-10-01

    In recent years there has been a strong development of computational approaches to mechanistically understand organ growth regulation in plants. In this study, simulation methods were used to explore which regulatory mechanisms can lead to realistic output at the cell and whole organ scale and which other possibilities must be discarded as they result in cellular patterns and kinematic characteristics that are not consistent with experimental observations for the Arabidopsis thaliana primary root. To aid in this analysis, a 'Uniform Longitudinal Strain Rule' (ULSR) was formulated as a necessary condition for stable, unidirectional, symplastic growth. Our simulations indicate that symplastic structures are robust to differences in longitudinal strain rates along the growth axis only if these differences are small and short-lived. Whereas simple cell-autonomous regulatory rules based on counters and timers can produce stable growth, it was found that steady developmental zones and smooth transitions in cell lengths are not feasible. By introducing spatial cues into growth regulation, those inadequacies could be avoided and experimental data could be faithfully reproduced. Nevertheless, a root growth model based on previous polar auxin-transport mechanisms violates the proposed ULSR due to the presence of lateral gradients. Models with layer-specific regulation or layer-driven growth offer potential solutions. Alternatively, a model representing the known cross-talk between auxin, as the cell proliferation promoting factor, and cytokinin, as the cell differentiation promoting factor, predicts the effect of hormone-perturbations on meristem size. By down-regulating PIN-mediated transport through the transcription factor SHY2, cytokinin effectively flattens the lateral auxin gradient, at the basal boundary of the division zone, (thereby imposing the ULSR) to signal the exit of proliferation and start of elongation. This model exploration underlines the value of

  2. Towards realistic representation of hydrological processes in integrated WRF-urban modeling system

    Science.gov (United States)

    Yang, Jiachuan; Wang, Zhi-hua; Chen, Fei; Miao, Shiguang; Tewari, Mukul; Georgescu, Matei

    2014-05-01

    To meet the demand of the ever-increasing urbanized global population, substantial conversion of natural landscapes to urban terrains is expected in the next few decades. The landscape modification will emerge as the source of many adverse effects that challenge the environmental sustainability of cities under changing climatic patterns. To address these adverse effects and to develop corresponding adaptation/mitigation strategies, physically-based single layer urban canopy model (SLUCM) has been developed and implemented into the Weather Research and Forecasting (WRF) platform. However, due to the lack of realistic representation of urban hydrological processes, simulation of urban climatology by current coupled WRF/SLUCM is inevitably inadequate. Aiming at improving the accuracy of simulations, in this study we implement physically-based parameterization of urban hydrological processes into the model, including (1) anthropogenic latent heat, (2) urban irrigation, (3) evaporation over water-holding engineered pavements, (4) urban oasis effect, and (5) green roof. In addition, we use an advanced Monte Carlo approach to quantify the sensitivity of urban hydrological modeling to parameter uncertainties. Evaluated against field observations at four major metropolitan areas, results show that the enhanced model is significantly improved in accurately predicting turbulent fluxes arising from built surfaces, especially the latent heat flux. Case studies show that green roof is capable of reducing urban surface temperature and sensible heat flux effectively, and modifying local and regional hydroclimate. Meanwhile, it is efficient in decreasing energy loading of buildings, not only cooling demand in summers but also heating demand in winters, through the combined evaporative cooling and insulation effect. Effectiveness of green roof is found to be limited by availability of water resources and highly sensitive to surface roughness heights. The enhanced WRF/SLUCM model

  3. On the validation of a realistic model of mesoscale coastal circulation in the Western Iberian Peninsula

    Science.gov (United States)

    Dubert, Jesus; Cordeiro, Nuno; Nolasco, Rita

    2010-05-01

    Realistic simulations of the circulation off the Western Iberian Peninsula, for the period 2001-2009 are compared against satellite observations of sea surface temperature (SST), for the summer upwelling season. This was done by means of comparisons of climatological means of monthly sst, standard deviation, and monthly anomalies obtained from satellite, and from the numerical model. Also, the observed mesoscale structures like filaments, are also compared with those obtained with the model, for the same period. The model consists in a ROMS-AGRIF configuration at ~3km resolution, forced with 6h NCEP2 reanalysis and Quikscat forcing for winds for the referred period, in the presence of river inflow for the main rivers of the region. The boundary conditions are obtained by offline nesting from a configuration of a larger domain, forced in the same way, and offshore Levitus climatological boundaries. The filament characterization for the satellite data, and the outputs of the numerical model, was done based on an automatic data treatment, which allows to study the filaments seasonal and interannual variability for the studied period. It was also made a study and a discussion of the surface climatology based on the satellite images and the model, in order to characterize, the surface temperature field, the monthly means, standard deviation and the deviations from the mean. In order to explain the observed and modelled anomalies, NCEP winds reanalysis are used in several points in the studied domain. The main purpose of this study is a step forward in the validation of the numerical configuration resolving mesoscale in the Western Iberian Peninsula, and to is to determine whether or not the model is able to reproduce the observed mesoscale features, the monthly anomalies of sst, and the monthly climatology.

  4. The realistic meaning of Larry’s image in The Razor’s Edge

    Institute of Scientific and Technical Information of China (English)

    王国婧

    2015-01-01

    Larry, a character in the novel The Razor's Edge written by British novelist Maugham, was shocked in the First World War and went into a way of exploring the meaning of life. In this paper, the author ana-lyzed the image of Larry as a free explorer and a selfless rescuer so as to probe into the image of Larry further and researched its corresponding realistic meaning; especially his image played an important role in guiding the explorative generation after the Second World War and representing the modern people in the realistic society. Larry surmounted the boundaries of the time and space, which revealed the plight of the people and showed a way of ideal life with realistic meaning.

  5. CERN Proton Synchrotron booster space charge simulations with a realistic model for alignment and field errors*

    Science.gov (United States)

    Forte, V.; Benedetto, E.; McAteer, M.

    2016-12-01

    The CERN Proton Synchrotron booster (PSB) is one of the machines of the LHC injector chain which will be upgraded within the LHC Injectors Upgrade (LIU) project. The injection energy of the PSB will be increased to 160 MeV in order to mitigate direct space charge effects, considered to be the main performance limitation, aiming to double the brightness for the LHC beams. In order to better predict the gain to be expected, space charge simulations are being carried out. As a first step, benchmarking between simulations and measurements is needed. Efforts to establish a realistic modeling of field and alignment errors aim at extending the basic model of the machine toward a more realistic one. Simulations of beam dynamics with strong space charge and realistic errors are presented and analyzed in this paper.

  6. Shadow obstacle model for realistic corner-turning behavior in crowd simulation

    Institute of Scientific and Technical Information of China (English)

    Gao-qi HE; Yi JIN; Qi CHEN; Zhen LIU; Wen-hui YUE; Xing-jian LU

    2016-01-01

    This paper describes a novel model known as the shadow obstacle model to generate a realistic corner-turning be-havior in crowd simulation. The motivation for this model comes from the observation that people tend to choose a safer route rather than a shorter one when turning a corner. To calculate a safer route, an optimization method is proposed to generate the corner-turning rule that maximizes the viewing range for the agents. By combining psychological and physical forces together, a full crowd simulation framework is established to provide a more realistic crowd simulation. We demonstrate that our model produces a more realistic corner-turning behavior by comparison with real data obtained from the experiments. Finally, we per-form parameter analysis to show the believability of our model through a series of experiments.

  7. A realist evaluation of the management of a well- performing regional hospital in Ghana

    Directory of Open Access Journals (Sweden)

    Kegels Guy

    2010-01-01

    Full Text Available Abstract Background Realist evaluation offers an interesting approach to evaluation of interventions in complex settings, but has been little applied in health care. We report on a realist case study of a well performing hospital in Ghana and show how such a realist evaluation design can help to overcome the limited external validity of a traditional case study. Methods We developed a realist evaluation framework for hypothesis formulation, data collection, data analysis and synthesis of the findings. Focusing on the role of human resource management in hospital performance, we formulated our hypothesis around the high commitment management concept. Mixed methods were used in data collection, including individual and group interviews, observations and document reviews. Results We found that the human resource management approach (the actual intervention included induction of new staff, training and personal development, good communication and information sharing, and decentralised decision-making. We identified 3 additional practices: ensuring optimal physical working conditions, access to top managers and managers' involvement on the work floor. Teamwork, recognition and trust emerged as key elements of the organisational climate. Interviewees reported high levels of organisational commitment. The analysis unearthed perceived organisational support and reciprocity as underlying mechanisms that link the management practices with commitment. Methodologically, we found that realist evaluation can be fruitfully used to develop detailed case studies that analyse how management interventions work and in which conditions. Analysing the links between intervention, mechanism and outcome increases the explaining power, while identification of essential context elements improves the usefulness of the findings for decision-makers in other settings (external validity. We also identified a number of practical difficulties and priorities for further

  8. A study on the equalization of market share under the perspective of competition--based on the model construction and realistic explanation%竞争视角下市场占有均衡:理论模型与现实解释

    Institute of Scientific and Technical Information of China (English)

    彭清华

    2013-01-01

    As the rational behavior of economic entities, market share is achieved by the way of competition and policy. From the balanced model of market share, this paper studied that the economic entities occupy the market based on the preference for market share, and adjust the preference for market share according to the revenue and goal’s changing, which forms the new equalization of market share. Differences on the competitor’s reaction will lead to the different equalization of market share. Based on the balance model of market share, the paper made a new explanation on the economic phenomena, such as the shortage of the public product,vicious competition and the state-owned enterprise reform.%市场占有行为是经济主体的理性行为,市场占有的实现方式有市场竞争与政策约束。文章构建市场占有均衡模型,指出经济主体基于自身的市场占有偏好进行市场占有,并根据市场收益的增减或发展目标的重新设计分别对市场占有偏好进行自发性纠正、战略性纠正,从而形成新的市场占有均衡。市场占有均衡因对手的竞争反应的差异而表现出不同的均衡状态。基于市场占有均衡模型,文章以新的角度审视了公共产品供给不足、厂商恶性竞争及国企改革等经济现象。

  9. Towards a unified European electricity market: The contribution of data-mining to support realistic simulation studies

    DEFF Research Database (Denmark)

    Pinto, Tiago; Santos, Gabriel; Pereira, Ivo F.;

    2014-01-01

    and implications that electricity markets transformations will bring to the participant countries. A case study using MASCEM (Multi-Agent System for Competitive Electricity Markets) is presented, with a scenario based on real data, simulating the European Electricity Market environment, and comparing its...... to support operators, regulators, and involved players for understanding and dealing with this complex environment. This paper focuses on demonstrating the advantage that real electricity markets data has for the creation of realistic simulation scenarios, which allow the study of the impacts......Worldwide electricity markets have been evolving into regional and even continental scales. The aim at an efficient use of renewable based generation in places where it exceeds the local needs is one of the main reasons. A reference case of this evolution is the European Electricity Market, where...

  10. Facile and Gram-scale Synthesis of Metal-free Catalysts: Toward Realistic Applications for Fuel Cells

    Science.gov (United States)

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-01

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  11. Facile and gram-scale synthesis of metal-free catalysts: toward realistic applications for fuel cells.

    Science.gov (United States)

    Kim, Ok-Hee; Cho, Yong-Hun; Chung, Dong Young; Kim, Min Jeong; Yoo, Ji Mun; Park, Ji Eun; Choe, Heeman; Sung, Yung-Eun

    2015-03-02

    Although numerous reports on nonprecious metal catalysts for replacing expensive Pt-based catalysts have been published, few of these studies have demonstrated their practical application in fuel cells. In this work, we report graphitic carbon nitride and carbon nanofiber hybrid materials synthesized by a facile and gram-scale method via liquid-based reactions, without the use of toxic materials or a high pressure-high temperature reactor, for use as fuel cell cathodes. The resulting materials exhibited remarkable methanol tolerance, selectivity, and stability even without a metal dopant. Furthermore, these completely metal-free catalysts exhibited outstanding performance as cathode materials in an actual fuel cell device: a membrane electrode assembly with both acidic and alkaline polymer electrolytes. The fabrication method and remarkable performance of the single cell produced in this study represent progressive steps toward the realistic application of metal-free cathode electrocatalysts in fuel cells.

  12. Ultra-realistic imaging advanced techniques in analogue and digital colour holography

    CERN Document Server

    Bjelkhagen, Hans

    2013-01-01

    Ultra-high resolution holograms are now finding commercial and industrial applications in such areas as holographic maps, 3D medical imaging, and consumer devices. Ultra-Realistic Imaging: Advanced Techniques in Analogue and Digital Colour Holography brings together a comprehensive discussion of key methods that enable holography to be used as a technique of ultra-realistic imaging.After a historical review of progress in holography, the book: Discusses CW recording lasers, pulsed holography lasers, and reviews optical designs for many of the principal laser types with emphasis on attaining th

  13. The Realistic Fallacy, or: The Conception of Literary Narrative Fiction in Analytic Aesthetics

    OpenAIRE

    Jukka Mikkonen

    2009-01-01

    In this paper, my aim is to show that in Anglo-American analytic aesthetics, the conception of narrative fiction is in general realistic and that it derives from philosophical theories of fiction-making, the act of producing works of literary narrative fiction. I shall firstly broadly show the origins of the problem and illustrate how the so-called realistic fallacy – the view which maintains that fictions consist of propositions which represent the fictional world “as it is” – is committed t...

  14. Active and realistic passive marijuana exposure tested by three immunoassays and GC/MS in urine

    Energy Technology Data Exchange (ETDEWEB)

    Mule, S.J.; Lomax, P.; Gross, S.J.

    1988-05-01

    Human urine samples obtained before and after active and passive exposure to marijuana were analyzed by immune kits (Roche, Amersham, and Syva) and gas chromatography/mass spectrometry (GC/MS). Seven of eight subjects were positive for the entire five-day test period with one immune kit. The latter correlated with GC/MS in 98% of the samples. Passive inhalation experiments under conditions likely to reflect realistic exposure resulted consistently in less than 10 ng/mL of cannabinoids. The 10-100-ng/mL cannabinoid concentration range essential for detection of occasional and moderate marijuana users is thus unaffected by realistic passive inhalation.

  15. Didactic Contracts in Realistic Mathematics Education Teaching Practice in Indonesia: A lesson on addition

    DEFF Research Database (Denmark)

    Putra, Zetra Hainul

    This paper aims to investigate characterize features of didactic contracts in realistic mathematics education teaching practice in Indonesia in the case of a lesson on addition. We just focus on some episodes of 26 first grade students and a female teacher from SDN 197 Palembang learning combinat......This paper aims to investigate characterize features of didactic contracts in realistic mathematics education teaching practice in Indonesia in the case of a lesson on addition. We just focus on some episodes of 26 first grade students and a female teacher from SDN 197 Palembang learning...

  16. Managing Algorithmic Skeleton Nesting Requirements in Realistic Image Processing Applications: The Case of the SKiPPER-II Parallel Programming Environment's Operating Model

    Directory of Open Access Journals (Sweden)

    Duculty Florent

    2005-01-01

    Full Text Available SKiPPER is a SKeleton-based Parallel Programming EnviRonment being developed since 1996 and running at LASMEA Laboratory, the Blaise-Pascal University, France. The main goal of the project was to demonstrate the applicability of skeleton-based parallel programming techniques to the fast prototyping of reactive vision applications. This paper deals with the special features embedded in the latest version of the project: algorithmic skeleton nesting capabilities and a fully dynamic operating model. Throughout the case study of a complete and realistic image processing application, in which we have pointed out the requirement for skeleton nesting, we are presenting the operating model of this feature. The work described here is one of the few reported experiments showing the application of skeleton nesting facilities for the parallelisation of a realistic application, especially in the area of image processing. The image processing application we have chosen is a 3D face-tracking algorithm from appearance.

  17. Towards a more realistic population of bright spiral galaxies in cosmological simulations

    Science.gov (United States)

    Aumer, Michael; White, Simon D. M.; Naab, Thorsten; Scannapieco, Cecilia

    2013-10-01

    We present an update to the multiphase smoothed particle hydrodynamics galaxy formation code by Scannapieco et al. We include a more elaborate treatment of the production of metals, cooling rates based on individual element abundances and a scheme for the turbulent diffusion of metals. Our supernova feedback model now transfers energy to the interstellar medium (ISM) in kinetic and thermal form, and we include a prescription for the effects of radiation pressure from massive young stars on the ISM. We calibrate our new code on the well-studied Aquarius haloes and then use it to simulate a sample of 16 galaxies with halo masses between 1 × 1011 and 3 × 1012 M⊙. In general, the stellar masses of the sample agree well with the stellar mass to halo mass relation inferred from abundance matching techniques for redshifts z = 0-4. There is however a tendency to overproduce stars at z > 4 and to underproduce them at z metallicities at z = 0-3. Remaining discrepancies can be connected to deviations from predictions for star formation histories from abundance matching. At z = 0, the model galaxies show realistic morphologies, stellar surface density profiles, circular velocity curves and stellar metallicities, but overly flat metallicity gradients. 15 out of 16 of our galaxies contain disc components with kinematic disc fraction ranging between 15 and 65 per cent. The disc fraction depends on the time of the last destructive merger or misaligned infall event. Considering the remaining shortcomings of our simulations we conclude that even higher kinematic disc fractions may be possible for Λ cold dark matter haloes with quiet merger histories, such as the Aquarius haloes.

  18. Protocol: developing a conceptual framework of patient mediated knowledge translation, systematic review using a realist approach

    Directory of Open Access Journals (Sweden)

    Wiljer David

    2011-03-01

    Full Text Available Abstract Background Patient involvement in healthcare represents the means by which to achieve a healthcare system that is responsive to patient needs and values. Characterization and evaluation of strategies for involving patients in their healthcare may benefit from a knowledge translation (KT approach. The purpose of this knowledge synthesis is to develop a conceptual framework for patient-mediated KT interventions. Methods A preliminary conceptual framework for patient-mediated KT interventions was compiled to describe intended purpose, recipients, delivery context, intervention, and outcomes. A realist review will be conducted in consultation with stakeholders from the arthritis and cancer fields to explore how these interventions work, for whom, and in what contexts. To identify patient-mediated KT interventions in these fields, we will search MEDLINE, the Cochrane Library, and EMBASE from 1995 to 2010; scan references of all eligible studies; and examine five years of tables of contents for journals likely to publish quantitative or qualitative studies that focus on developing, implementing, or evaluating patient-mediated KT interventions. Screening and data collection will be performed independently by two individuals. Conclusions The conceptual framework of patient-mediated KT options and outcomes could be used by healthcare providers, managers, educationalists, patient advocates, and policy makers to guide program planning, service delivery, and quality improvement and by us and other researchers to evaluate existing interventions or develop new interventions. By raising awareness of options for involving patients in improving their own care, outcomes based on using a KT approach may lead to greater patient-centred care delivery and improved healthcare outcomes.

  19. Cortical Sources of ERP in Prosaccade and Antisaccade Eye Movements using Realistic Source Models

    Directory of Open Access Journals (Sweden)

    John E Richards

    2013-07-01

    Full Text Available The cortical sources of event-related-potentials (ERP using realistic source models were examined in a prosaccade and antisaccade task. College-age participants were presented with a preparatory interval and a target that indicated the direction of the eye movement that was to be made. In some blocks a cue was given in the peripheral location where the target was to be presented and in other blocks no cue was given. In Experiment 1 the prosaccade and antisaccade trials were presented randomly within a block; in Experiment 2 procedures were compared in which either prosaccade and antisaccade trials were mixed in the same block, or trials were presented in separate blocks with only one type of eye movement. There was a central negative slow wave occurring prior to the target, a slow positive wave over the parietal scalp prior to the saccade, and a parietal spike potential immediately prior to saccade onset. Cortical source analysis of these ERP components showed a common set of sources in the ventral anterior cingulate and orbital frontal gyrus for the presaccadic positive slow wave and the spike potential. In Experiment 2 the same cued- and non-cued blocks were used, but prosaccade and antisaccade trials were presented in separate blocks. This resulted in a smaller difference in reaction time between prosaccade and antisaccade trials. Unlike the first experiment, the central negative slow wave was larger on antisaccade than on prosaccade trials, and this effect on the ERP component had its cortical source primarily in the parietal and mid-central cortical areas contralateral to the direction of the eye movement. These results suggest that blocked prosaccade and antisaccade trials results in preparatory or set effects that decreases reaction time, eliminates some cueing effects, and is based on contralateral parietal-central brain areas.

  20. Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ′ Microstructures

    Directory of Open Access Journals (Sweden)

    Aruna Prakash

    2017-01-01

    Full Text Available Single-crystal Ni-base superalloys, consisting of a two-phase γ/ γ ′ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ ′ phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ/ γ ′ microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ ′ particles with planar γ/ γ ′ interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples—the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions.

  1. Computation of realistic virtual phantom images for an objective lesion detectability assessment in digital mammography.

    Science.gov (United States)

    Perez-Ponce, Hector; Daul, Christian; Wolf, Didier; Noel, Alain

    2011-12-01

    Image quality assessment is required for an optimal use of mammographic units. On the one hand, there are objective image quality assessment methods based on the measurement of technical parameters such as modulation transfer function (MTF), noise power spectrum (NPS) or detection quantum efficiency (DQE) describing performances of digital detectors. These parameters are, however, without direct relationship with lesion detectability in clinical practice. On the other hand, there are image quality assessment methods involving time consuming procedures, but presenting a direct relationship with lesion detectability. This contribution describes an X-ray source/digital detector model leading to the simulation of virtual contrast-detail phantom (CDMAM) images. The virtual image computation method requires the acquisition of only few real images and allows for an objective image quality assessment presenting a direct relationship with lesion detectability. The transfer function of the proposed model takes as input physical parameters (MTF* and noise) measured under clinical conditions on mammographic units. As presented in this contribution, MTF* is a modified MTF taking into account the effects due to X-ray scatter in the breast and magnification. Results obtained with the structural similarity index prove that the simulated images are quite realistic in terms of contrast and noise. Tests using contrast detail curves highlight the fact that the simulated and real images lead to very similar data quality in terms of lesion detectability. Finally, various statistical tests show that quality factors computed for both the simulated images and the real images are very close for the two data sets.

  2. The photochemistry of pyrimidine in realistic astrophysical ices and the production of nucleobases

    Energy Technology Data Exchange (ETDEWEB)

    Nuevo, Michel; Materese, Christopher K.; Sandford, Scott A., E-mail: michel.nuevo-1@nasa.gov [NASA Ames Research Center, MS 245-6, Moffett Field, CA 94035 (United States)

    2014-10-01

    Nucleobases, together with deoxyribose/ribose and phosphoric acid, are the building blocks of DNA and RNA for all known life. The presence of nucleobase-like compounds in carbonaceous chondrites delivered to the Earth raises the question of an extraterrestrial origin for the molecules that triggered life on our planet. Whether these molecules are formed in interstellar/protostellar environments, in small parent bodies in the solar system, or both, is currently unclear. Recent experiments show that the UV irradiation of pyrimidine (C{sub 4}H{sub 4}N{sub 2}) in H{sub 2}O-rich ice mixtures that contain NH{sub 3}, CH{sub 3}OH, or CH{sub 4} leads to the formation of the pyrimidine-based nucleobases uracil, cytosine, and thymine. In this work, we discuss the low-temperature UV irradiation of pyrimidine in realistic astrophysical ice mixtures containing H{sub 2}O, CH{sub 3}OH, and NH{sub 3}, with or without CH{sub 4}, to search for the production of nucleobases and other prebiotic compounds. These experiments show the presence of uracil, urea, glycerol, hexamethylenetetramine, small amino acids, and small carboxylic acids in all samples. Cytosine was only found in one sample produced from ices irradiated with a higher UV dose, while thymine was not found in any sample, even after irradiation with a higher UV dose. Results are discussed to evaluate the role of the photochemistry of pyrimidine in the inventory of organic molecules detected in meteorites and their astrophysical/astrobiological implications.

  3. Strengthening the implementation of Health in All Policies: a methodology for realist explanatory case studies.

    Science.gov (United States)

    Shankardass, Ketan; Renahy, Emilie; Muntaner, Carles; O'Campo, Patricia

    2015-05-01

    To address macro-social and economic determinants of health and equity, there has been growing use of intersectoral action by governments around the world. Health in All Policies (HiAP) initiatives are a special case where governments use cross-sectoral structures and relationships to systematically address health in policymaking by targeting broad health determinants rather than health services alone. Although many examples of HiAP have emerged in recent decades, the reasons for their successful implementation--and for implementation failures--have not been systematically studied. Consequently, rigorous evidence based on systematic research of the social mechanisms that have regularly enabled or hindered implementation in different jurisdictions is sparse. We describe a novel methodology for explanatory case studies that use a scientific realist perspective to study the implementation of HiAP. Our methodology begins with the formulation of a conceptual framework to describe contexts, social mechanisms and outcomes of relevance to the sustainable implementation of HiAP. We then describe the process of systematically explaining phenomena of interest using evidence from literature and key informant interviews, and looking for patterns and themes. Finally, we present a comparative example of how Health Impact Assessment tools have been utilized in Sweden and Quebec to illustrate how this methodology uses evidence to first describe successful practices for implementation of HiAP and then refine the initial framework. The methodology that we describe helps researchers to identify and triangulate rich evidence describing social mechanisms and salient contextual factors that characterize successful practices in implementing HiAP in specific jurisdictions. This methodology can be applied to study the implementation of HiAP and other forms of intersectoral action to reduce health inequities involving multiple geographic levels of government in diverse settings.

  4. The Effectivenss of a Group Guidance Program on The Realistic Field Choice Amondst First Year High

    Directory of Open Access Journals (Sweden)

    Davut AYDIN

    2007-06-01

    Full Text Available In this research, the effectiveness of a group guidance program in terms of assisting first year high school students to choose realistically their study field was examined.The research was carried out with 40 pupils who were randomly selected among the first year Özel Ferda Lisesi pupils, in Ankara, during the academic year 2001-2002.The subjects were separated to two groups: the experimental group which attended the group guidance program and the control group which did not. Both groups were tested before the guidance program was implemented and after.The program developed by the researcher, was mainly based on cognitive-behavioural approach with a substantial emphasis on informational and interactional techniques.The independent variable of the research was the group guidance program that was applied to the experimental group. The dependent variable of the study was students’ aptitude points.The program consisted of 12 sessions and it was administered every five days. Each session lasted for about 90 minutes. After the last session of the program, the student evaluation scale, which was developed by Kuzgun, was given to both the experimental and the control group members. In order to test this hypothesis thedependent-samples t-test was used.The results indicated that the experimental group members’ score both in the aptitude test become closer to their teachers rating after the group guidance program while the control group members score did not change from the first to the second application of the test.

  5. Towards realistic Holocene land cover scenarios: integration of archaeological, palynological and geomorphological records and comparison to global land cover scenarios.

    Science.gov (United States)

    De Brue, Hanne; Verstraeten, Gert; Broothaerts, Nils; Notebaert, Bastiaan

    2016-04-01

    Accurate and spatially explicit landscape reconstructions for distinct time periods in human history are essential for the quantification of the effect of anthropogenic land cover changes on, e.g., global biogeochemical cycles, ecology, and geomorphic processes, and to improve our understanding of interaction between humans and the environment in general. A long-term perspective covering Mid and Late Holocene land use changes is recommended in this context, as it provides a baseline to evaluate human impact in more recent periods. Previous efforts to assess the evolution and intensity of agricultural land cover in past centuries or millennia have predominantly focused on palynological records. An increasing number of quantitative techniques has been developed during the last two decades to transfer palynological data to land cover estimates. However, these techniques have to deal with equifinality issues and, furthermore, do not sufficiently allow to reconstruct spatial patterns of past land cover. On the other hand, several continental and global databases of historical anthropogenic land cover changes based on estimates of global population and the required agricultural land per capita have been developed in the past decennium. However, at such long temporal and spatial scales, reconstruction of past anthropogenic land cover intensities and spatial patterns necessarily involves many uncertainties and assumptions as well. Here, we present a novel approach that combines archaeological, palynological and geomorphological data for the Dijle catchment in the central Belgium Loess Belt in order to arrive at more realistic Holocene land cover histories. Multiple land cover scenarios (> 60.000) are constructed using probabilistic rules and used as input into a sediment delivery model (WaTEM/SEDEM). Model outcomes are confronted with a detailed geomorphic dataset on Holocene sediment fluxes and with REVEALS based estimates of vegetation cover using palynological data from

  6. 深化战略合作期的中国与印尼经贸问题及对策--基于印尼语文献的分析%Reflections on Realistic Problems and Solutions of Chinese-Indonesian Economic and Trade Cooperation in the Period of Overall Strategic Cooperation:An Analysis Based on Indonesian Literature

    Institute of Scientific and Technical Information of China (English)

    武政文

    2014-01-01

    Indonesia is the most populous country in Southeast Asia and is also the most geo-strategic e-conomy of ASEAN.After the establishment of the strategic partnership between China and Indonesia, the bi-lateral economic and trade relation gets closest laterally and longitudinally.In the reality of contemporary in-ternational environment to keep a deeper bilateral trade and economic partnership, the relation has become a new future focus.In perspective of geo-strategy, the current bilateral trade and economic partnership still a main traditional commodity trade, but there is still much development in the other deeper strategic coopera-tion in the future.The study based on Indonesian literature can offer new notion and new strategies for Chi-na and Indonesia to enlarge their bilateral trade and economic cooperation in the framework of all-round strategic partnership.%印尼是东南亚地区人口最多的发展中国家,也是东盟内部最具地缘战略价值的经济体。中国与印尼在确立战略伙伴关系之后,双边的经贸关系无论是从横向上还是从纵向上都达到了有史以来最为密切的合作阶段,在当代的现实国际环境下继续深化拓展两国经贸合作关系已成为未来值得关注的新焦点。从地缘战略的视角来看,目前两国经贸合作关系仍以传统的商品贸易往来为主,对于财经领域内其他更深层次的战略性合作,在未来仍有很大的拓展空间。如果基于印尼语文献开展研究,可以为中国和印尼在战略伙伴关系框架下全方位拓展双边经贸合作关系提供新思路和新对策。

  7. Formation and stability of ridge-ridge-ridge triple junctions in rheologically realistic lithosphere model

    Science.gov (United States)

    Gerya, Taras; Burov, Evgueni

    2015-04-01

    Triple junctions are probably the most remarkable features of plate boundaries since their presence constitutes one of the major demonstrations of plate tectonics theory. Divergent (R-R-R) triple junctions (at 120° and T junctions) are particular ones since their stability depends on the exact values of the relative velocities of plate divergence and hence is strongly affected by plate rheology and processes of crustal accretion. The mechanisms of their formation and long-term steadiness are not well understood even though it is commonly accepted, generally based on common sense, that the geometry and stability of triple junctions should be related to the intuitively acceptable geometric considerations that 3-branch configurations should be "stable" over the time on a 3D Earth surface. That said, most plate boundaries are in fact 2D in terms that they involve only two plates, while junctions with 3 and more branches, if even mechanically not excluded, are generally short-lived and hence rarely observed at tectonic scale. Indeed, it has been long-time suggested that triple junctions result from evolution of short-lived quadruple junctions, yet, without providing a consistent mechanical explanation or experimental demonstration of this process, due to the rheological complexity of the lithosphere and that of strain localization and crustal accretion processes. For example, it is supposed that R-R-R junctions form as result of axisymmetric mantle upwellings. However, impingement of buoyant fluid on a non-pre-stressed lithosphere should result in multiple radial cracks, as is well known from previous analog and numerical experiments. In case of uni-directionally pre-stressed lithosphere, it has also shown that linear 2D rift structures should be formed. Therefore, a complete 3D thermos-mechanically consistent approach is needed to understand the processes of formation of multi-branch junctions. With this goal we here reproduce and study the processes of multi

  8. Forming Realistic Late-type Spirals in a ΛCDM Universe: The Eris Simulation

    Science.gov (United States)

    Guedes, Javiera; Callegari, Simone; Madau, Piero; Mayer, Lucio

    2011-12-01

    Simulations of the formation of late-type spiral galaxies in a cold dark matter (ΛCDM) universe have traditionally failed to yield realistic candidates. Here we report a new cosmological N-body/smooth particle hydrodynamic simulation of extreme dynamic range in which a close analog of a Milky Way disk galaxy arises naturally. Named "Eris," the simulation follows the assembly of a galaxy halo of mass M vir = 7.9 × 1011 M ⊙ with a total of N = 18.6 million particles (gas + dark matter + stars) within the final virial radius, and a force resolution of 120 pc. It includes radiative cooling, heating from a cosmic UV field and supernova explosions (blastwave feedback), a star formation recipe based on a high gas density threshold (n SF = 5 atoms cm-3 rather than the canonical n SF = 0.1 atoms cm-3), and neglects any feedback from an active galactic nucleus. Artificial images are generated to correctly compare simulations with observations. At the present epoch, the simulated galaxy has an extended rotationally supported disk with a radial scale length Rd = 2.5 kpc, a gently falling rotation curve with circular velocity at 2.2 disk scale lengths of V 2.2 = 214 km s-1, an i-band bulge-to-disk ratio B/D = 0.35, and a baryonic mass fraction within the virial radius that is 30% below the cosmic value. The disk is thin, has a typical H I-to-stellar mass ratio, is forming stars in the region of the ΣSFR-ΣH I plane occupied by spiral galaxies, and falls on the photometric Tully-Fisher and the stellar-mass-halo-virial-mass relations. Hot (T > 3 × 105 K) X-ray luminous halo gas makes up only 26% of the universal baryon fraction and follows a "flattened" density profile vpropr -1.13 out to r = 100 kpc. Eris appears then to be the first cosmological hydrodynamic simulation in which the galaxy structural properties, the mass budget in the various components, and the scaling relations between mass and luminosity are all consistent with a host of observational constraints. A

  9. FORMING REALISTIC LATE-TYPE SPIRALS IN A {Lambda}CDM UNIVERSE: THE ERIS SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Guedes, Javiera; Madau, Piero [Department of Astronomy and Astrophysics, University of California, 1156 High Street, Santa Cruz, CA 95064 (United States); Callegari, Simone [Institute for Theoretical Physics, University of Zuerich, Winterthurerstrasse 190, CH-9057 Zuerich (Switzerland); Mayer, Lucio [Institute for Astronomy, ETH Zuerich, Wolgang-Pauli-Strasse 27, 8093 Zuerich (Switzerland)

    2011-12-01

    Simulations of the formation of late-type spiral galaxies in a cold dark matter ({Lambda}CDM) universe have traditionally failed to yield realistic candidates. Here we report a new cosmological N-body/smooth particle hydrodynamic simulation of extreme dynamic range in which a close analog of a Milky Way disk galaxy arises naturally. Named 'Eris', the simulation follows the assembly of a galaxy halo of mass M{sub vir} = 7.9 Multiplication-Sign 10{sup 11} M{sub Sun} with a total of N = 18.6 million particles (gas + dark matter + stars) within the final virial radius, and a force resolution of 120 pc. It includes radiative cooling, heating from a cosmic UV field and supernova explosions (blastwave feedback), a star formation recipe based on a high gas density threshold (n{sub SF} = 5 atoms cm{sup -3} rather than the canonical n{sub SF} = 0.1 atoms cm{sup -3}), and neglects any feedback from an active galactic nucleus. Artificial images are generated to correctly compare simulations with observations. At the present epoch, the simulated galaxy has an extended rotationally supported disk with a radial scale length R{sub d} = 2.5 kpc, a gently falling rotation curve with circular velocity at 2.2 disk scale lengths of V{sub 2.2} = 214 km s{sup -1}, an i-band bulge-to-disk ratio B/D = 0.35, and a baryonic mass fraction within the virial radius that is 30% below the cosmic value. The disk is thin, has a typical H I-to-stellar mass ratio, is forming stars in the region of the {Sigma}{sub SFR}-{Sigma}{sub HI} plane occupied by spiral galaxies, and falls on the photometric Tully-Fisher and the stellar-mass-halo-virial-mass relations. Hot (T > 3 Multiplication-Sign 10{sup 5} K) X-ray luminous halo gas makes up only 26% of the universal baryon fraction and follows a 'flattened' density profile {proportional_to}r{sup -1.13} out to r = 100 kpc. Eris appears then to be the first cosmological hydrodynamic simulation in which the galaxy structural properties, the

  10. Realistic simulations of tsunami detection by High-Frequency Radar in British Columbia, Canada

    Science.gov (United States)

    Grilli, Stéphan; Shelby, Michael; Grilli, Annette; Lado Insua, Tania; Guérin, Charles-Antoine

    2016-04-01

    A promising technique for long-range detection of tsunamis is the use of shore-based High Frequency (HF) surface wave radars, also simply referred to as oceanographic radars. These over-the-horizon radars are routinely used for real-time monitoring of ocean surface currents up to a 70-80 km range, based on the Doppler shift the latter cause in ocean waves at the radar Bragg frequency. Quite recently there has been convincing numerical and experimental evidence that oceanographic radars can also be used to detect tsunami-induced surface currents. However, these need to be at least 0.15-0.20 m/s to be detectable, when considering environmental noise and background currents (from tide and mesoscale circulation). This limits the actual detection of tsunami currents to the near range, that is essentially to the continental shelf over which tsunami currents become strong enough; in many cases this does not leave enough time to issue an efficient warning, unless there is a wide shelf. In recent work, some of the authors have proposed a detection algorithm that does not have this limitation and can detect an approaching tsunami in deeper water, beyond the continental shelf. This algorithm does not require "inverting" currents, but instead is based on spatial correlations of the raw signals recorded at two distant radar cells along the same wave ray, shifted in time by the tsunami propagation time along the ray. An elevated correlation would indicate the presence of a tsunami. We apply this algorithm to a realistic tsunami case study conducted, using a state-of-the-art long wave model, for sources (both seismic and landslide) and bathymetry off of Vancouver Island, BC. The propagation time between different radar cells is calculated with a Geometrical Optics approach using the Eikonal equation. This requires first determining wave rays' intersections with radar cells and computing a connectivity matrix between the latter. A model simulating the radar backscattered signal in

  11. Using realist synthesis to understand the mechanisms of interprofessional teamwork in health and social care.

    Science.gov (United States)

    Hewitt, Gillian; Sims, Sarah; Harris, Ruth

    2014-11-01

    Realist synthesis offers a novel and innovative way to interrogate the large literature on interprofessional teamwork in health and social care teams. This article introduces realist synthesis and its approach to identifying and testing the underpinning processes (or "mechanisms") that make an intervention work, the contexts that trigger those mechanisms and their subsequent outcomes. A realist synthesis of the evidence on interprofessional teamwork is described. Thirteen mechanisms were identified in the synthesis and findings for one mechanism, called "Support and value" are presented in this paper. The evidence for the other twelve mechanisms ("collaboration and coordination", "pooling of resources", "individual learning", "role blurring", "efficient, open and equitable communication", "tactical communication", "shared responsibility and influence", "team behavioural norms", "shared responsibility and influence", "critically reviewing performance and decisions", "generating and implementing new ideas" and "leadership") are reported in a further three papers in this series. The "support and value" mechanism referred to the ways in which team members supported one another, respected other's skills and abilities and valued each other's contributions. "Support and value" was present in some, but far from all, teams and a number of contexts that explained this variation were identified. The article concludes with a discussion of the challenges and benefits of undertaking this realist synthesis.

  12. Validation of CT brain perfusion methods using a realistic dynamic head phantom

    NARCIS (Netherlands)

    Riordan, A.J.; Prokop, M.; Viergever, M.A.; Dankbaar, J.W.; Smit, E.J.; Jong, H.W. de

    2011-01-01

    PURPOSE: Development and evaluation of a realistic hybrid head phantom for the validation of quantitative CT brain perfusion methods. METHODS: A combination, or hybrid, of CT images of an anthropomorphic head phantom together with clinically acquired MRI brain images was used to construct a dynamic

  13. Assessing Outcomes of a Realistic Major Preview in an Introductory Sport Management Course

    Science.gov (United States)

    Pierce, David; Wanless, Elizabeth; Johnson, James

    2014-01-01

    This paper assessed the outcomes of a field experience assignment (FEA) in an introductory sport management course designed as a realistic major preview. Student learning outcomes assessed were commitment to the major, intent to pursue the major, expectation of a career in sports, and perceived preparation for a career in sports. A…

  14. Depictions and Gaps: Portrayal of U.S. Poverty in Realistic Fiction Children's Picture Books

    Science.gov (United States)

    Kelley, Jane E.; Darragh, Janine J.

    2011-01-01

    Researchers conducted a critical multicultural analysis of 58 realistic fiction children's picture books that portray people living in poverty and compared these depictions to recent statistics from the United States Census Bureau. The picture books were examined for the following qualities: main character, geographic locale and time era, focal…

  15. Are These Parents for Real? Students' Views of Parents in Realistic and Historical Fiction.

    Science.gov (United States)

    Harmon, Janis M.; Gonzales, Monica C.

    2003-01-01

    Describes what students had to say about parental roles. Includes students' views about parental roles in real life, their expectations of parental roles in realistic and historical novels, their impressions of the parents they encountered in the selected books, and a comparison across genres about these parental characters. Presents guidelines…

  16. Middle Grade Students' Responses to Canadian Realistic Fiction for Young Adults.

    Science.gov (United States)

    Latshaw, Jessica L. K.

    1991-01-01

    Student responses to Canadian realistic fiction for young adults were examined for four seventh grade girls and three seventh grade boys. Interview findings support the view that students should have a role in selecting what they read, should talk about reading informally, and should construct representations less influenced by teacher responses.…

  17. Heroes and Victims: The Stereotyping of Animal Characters in Children's Realistic Animal Fiction.

    Science.gov (United States)

    Oswald, Lori Jo

    1995-01-01

    Discusses portrayals of animals in children's realistic animal fiction over the course of the 20th century. Shows how the definition of animal hero generally changed from wild animals that were heroic for surviving against all odds to domesticated animals that were heroic for rescuing humans from wild beasts. Discusses animals as victims. (SR)

  18. A rapid algorithm for realistic human reaching and its use in a virtual reality system

    Science.gov (United States)

    Aldridge, Ann; Pandya, Abhilash; Goldsby, Michael; Maida, James

    1994-01-01

    The Graphics Analysis Facility (GRAF) at JSC has developed a rapid algorithm for computing realistic human reaching. The algorithm was applied to GRAF's anthropometrically correct human model and used in a 3D computer graphics system and a virtual reality system. The nature of the algorithm and its uses are discussed.

  19. Realistic tool-tissue interaction models for surgical simulation and planning

    NARCIS (Netherlands)

    Misra, Sarthak

    2009-01-01

    Surgical simulators present a safe and potentially effective method for surgical training, and can also be used in pre- and intra-operative surgical planning. Realistic modeling of medical interventions involving tool-tissue interactions has been considered to be a key requirement in the development

  20. Validation of a realistic powder sample using data from DMC at PSI

    DEFF Research Database (Denmark)

    Willendrup, Peter Kjær; Filges, U.; Keller, L.

    2006-01-01

    We present results of a virtual experiment, carried out by means of a McStas simulation of the powder diffractometer DMC at PSI, using the new powder sample component PowderN. This powder component takes tabulated crystallographic input to define realistic powder lines. The simulated output data ...

  1. Design Research in the Netherlands: Introducing Logarithms Using Realistic Mathematics Education

    Science.gov (United States)

    Webb, David C.; van der Kooij, Henk; Geist, Monica R.

    2011-01-01

    This article describes Realistic Mathematics Education (RME), a design theory for mathematics education proposed by Hans Freudenthal and developed over 40 years of developmental research at the Freudenthal Institute for Science and Mathematics Education in the Netherlands. Activities from a unit to develop student understanding of logarithms are…

  2. A search engine for retrieval and inspection of events with 48 human actions in realistic videos

    NARCIS (Netherlands)

    Burghouts, G.J.; Penning, H.L.H. de; Hove, R.J.M. ten; Landsmeer, S.; Broek, S.P. van den; Hollander, R.J.M.; Hanckmann, P.; Kruithof, M.C.; Leeuwen, C.J. van; Korzec, S.; Bouma, H.; Schutte, K.

    2013-01-01

    The contribution of this paper is a search engine that recognizes and describes 48 human actions in realistic videos. The core algorithms have been published recently, from the early visual processing (Bouma, 2012), discriminative recognition (Burghouts, 2012) and textual description (Hankmann, 2012

  3. Cognitive Holding Power, Fluid Intelligence, and Mathematical Achievement as Predictors of Children's Realistic Problem Solving

    Science.gov (United States)

    Xin, Ziqiang; Zhang, Li

    2009-01-01

    The present study explored whether first and second order cognitive holding power perceived by children in mathematical classrooms, fluid intelligence, and mathematical achievement predicted their performance on standard problems, and especially realistic problems. A sample of 119 Chinese 4-6th graders were administered the word problem test, the…

  4. Do absorption and realistic distraction influence performance of component task surgical procedure?

    NARCIS (Netherlands)

    Pluyter, J.R.; Buzink, S.N.; Rutkowski, A.-F.; Jakimowicz, J.J.

    2009-01-01

    Background. Surgeons perform complex tasks while exposed to multiple distracting sources that may increase stress in the operating room (e.g., music, conversation, and unadapted use of sophisticated technologies). This study aimed to examine whether such realistic social and technological distractin

  5. A New Realistic Evaluation Analysis Method: Linked Coding of Context, Mechanism, and Outcome Relationships

    Science.gov (United States)

    Jackson, Suzanne F.; Kolla, Gillian

    2012-01-01

    In attempting to use a realistic evaluation approach to explore the role of Community Parents in early parenting programs in Toronto, a novel technique was developed to analyze the links between contexts (C), mechanisms (M) and outcomes (O) directly from experienced practitioner interviews. Rather than coding the interviews into themes in terms of…

  6. A Patent Analysis on Realistic Media for R&D Projects

    Science.gov (United States)

    Hwang, Sung-Hyun; Yeon, Seung-Jun

    In this paper, we use patent statistics as the recent status of R&D in international patents. The number of patents was used to compare different countries' share in the overall number of technology patents. Using the degree of patent citations, the influence and technological prowess of patents were examined. Also, implications were drawn from an analysis of patent contents for realistic media.

  7. Combining Campbell Standards and the Realist Evaluation Approach: The Best of Two Worlds?

    Science.gov (United States)

    van der Knaap, Leontien M.; Leeuw, Frans L.; Bogaerts, Stefan; Nijssen, Laura T. J.

    2008-01-01

    This article presents an approach to systematic reviews that combines the Campbell Collaboration Crime and Justice standards and the realist notion of contexts-mechanisms-outcomes (CMO) configurations. Both approaches have their advantages and drawbacks, and the authors will make a case for combining both approaches to profit from their advantages…

  8. NETMORPH: a framework for the stochastic generation of large scale neuronal networks with realistic neuron morphologies

    NARCIS (Netherlands)

    Koene, R.A.; Tijms, B.; van Hees, P.; Postma, F.; de Ridder, A.; Ramakers, G.J.A.; van Pelt, J.; van Ooyen, A.

    2009-01-01

    We present a simulation framework, called NETMORPH, for the developmental generation of 3D large-scale neuronal networks with realistic neuron morphologies. In NETMORPH, neuronal morphogenesis is simulated from the perspective of the individual growth cone. For each growth cone in a growing axonal o

  9. Two politicians in a realistic experiment: attraction, discrepancy, intensity of delivery, and attitude change

    NARCIS (Netherlands)

    Wiegman, O.

    1985-01-01

    The leader of the Socialists in the Dutch Parliament and his Liberal opponent participated in this realistic experiment. Identical TV interviews with the two politicians were recorded and shown to subjects of both parties. The intensity of delivery was also varied: emotional versus rational. Our fin

  10. Plasticity-modulated seizure dynamics for seizure termination in realistic neuronal models

    NARCIS (Netherlands)

    Koppert, M.M.J.; Kalitzin, S.; Lopes da Silva, F.H.; Viergever, M.A.

    2011-01-01

    In previous studies we showed that autonomous absence seizure generation and termination can be explained by realistic neuronal models eliciting bi-stable dynamics. In these models epileptic seizures are triggered either by external stimuli (reflex epilepsies) or by internal fluctuations. This scena

  11. Cold and hot cognition: quantum probability theory and realistic psychological modeling.

    Science.gov (United States)

    Corr, Philip J

    2013-06-01

    Typically, human decision making is emotionally "hot" and does not conform to "cold" classical probability (CP) theory. As quantum probability (QP) theory emphasises order, context, superimposition states, and nonlinear dynamic effects, one of its major strengths may be its power to unify formal modeling and realistic psychological theory (e.g., information uncertainty, anxiety, and indecision, as seen in the Prisoner's Dilemma).

  12. Comparing demand and consumption. A realistic energy balance; Abgleich von Bedarf und Verbrauch. Realistische Energiebilanz

    Energy Technology Data Exchange (ETDEWEB)

    Jagnow, Kati [Ingenieurbuero fuer Energieberatung, Braunschweig (Germany); Wolff, Dieter [Ostfalia Hochschule fuer Angewandte Wissenschaften, Braunschweig/Wolfenbuettel (Germany)

    2010-07-01

    The new appendix 1 of DIN V 18599 is to help users of the standard to either establish a realistic energy balance or - optimally - even to be able to match the calculated heat demand to the measured real consumption data. (orig.)

  13. Transforming the patient care environment with Lean Six Sigma and realistic evaluation.

    Science.gov (United States)

    Black, Jason

    2009-01-01

    Lean Six Sigma (LSS) is a structured methodology for transforming processes, but it does not fully consider the complex social interactions that cause processes to form in hospital organizations. By combining LSS implementations with the concept of Realistic Evaluation, a methodology that promotes change by assessing and considering the individual characteristics of an organization's social environment, successful and sustainable process improvement is more likely.

  14. Non-tachyonic semi-realistic non-supersymmetric heterotic-string vacua

    Science.gov (United States)

    Ashfaque, Johar M.; Athanasopoulos, Panos; Faraggi, Alon E.; Sonmez, Hasan

    2016-04-01

    The heterotic-string models in the free fermionic formulation gave rise to some of the most realistic-string models to date, which possess N=1 spacetime supersymmetry. Lack of evidence for supersymmetry at the LHC instigated recent interest in non-supersymmetric heterotic-string vacua. We explore what may be learned in this context from the quasi-realistic free fermionic models. We show that constructions with a low number of families give rise to proliferation of a priori tachyon producing sectors, compared to the non-realistic examples, which typically may contain only one such sector. The reason being that in the realistic cases the internal six dimensional space is fragmented into smaller units. We present one example of a quasi-realistic, non-supersymmetric, non-tachyonic, heterotic-string vacuum and compare the structure of its massless spectrum to the corresponding supersymmetric vacuum. While in some sectors supersymmetry is broken explicitly, i.e. the bosonic and fermionic sectors produce massless and massive states, other sectors, and in particular those leading to the chiral families, continue to exhibit Fermi-Bose degeneracy. In these sectors the massless spectrum, as compared to the supersymmetric cases, will only differ in some local or global U(1) charges. We discuss the conditions for obtaining n_b=n_f at the massless level in these models. Our example model contains an anomalous U(1) symmetry, which generates a tadpole diagram at one-loop order in string perturbation theory. We speculate that this tadpole diagram may cancel the corresponding diagram generated by the one-loop non-vanishing vacuum energy and that in this respect the supersymmetric and non-supersymmetric vacua should be regarded on an equal footing. Finally we discuss vacua that contain two supersymmetry generating sectors.

  15. Non-tachyonic semi-realistic non-supersymmetric heterotic-string vacua

    Energy Technology Data Exchange (ETDEWEB)

    Ashfaque, Johar M.; Athanasopoulos, Panos; Faraggi, Alon E.; Sonmez, Hasan [University of Liverpool, Department of Mathematical Sciences, Liverpool (United Kingdom)

    2016-04-15

    The heterotic-string models in the free fermionic formulation gave rise to some of the most realistic-string models to date, which possess N = 1 spacetime supersymmetry. Lack of evidence for supersymmetry at the LHC instigated recent interest in non-supersymmetric heterotic-string vacua. We explore what may be learned in this context from the quasi-realistic free fermionic models. We show that constructions with a low number of families give rise to proliferation of a priori tachyon producing sectors, compared to the non-realistic examples, which typically may contain only one such sector. The reason being that in the realistic cases the internal six dimensional space is fragmented into smaller units. We present one example of a quasi-realistic, non-supersymmetric, non-tachyonic, heterotic-string vacuum and compare the structure of its massless spectrum to the corresponding supersymmetric vacuum. While in some sectors supersymmetry is broken explicitly, i.e. the bosonic and fermionic sectors produce massless and massive states, other sectors, and in particular those leading to the chiral families, continue to exhibit Fermi-Bose degeneracy. In these sectors the massless spectrum, as compared to the supersymmetric cases, will only differ in some local or global U(1) charges. We discuss the conditions for obtaining n{sub b} = n{sub f} at the massless level in these models. Our example model contains an anomalous U(1) symmetry, which generates a tadpole diagram at one-loop order in string perturbation theory. We speculate that this tadpole diagram may cancel the corresponding diagram generated by the one-loop non-vanishing vacuum energy and that in this respect the supersymmetric and non-supersymmetric vacua should be regarded on an equal footing. Finally we discuss vacua that contain two supersymmetry generating sectors. (orig.)

  16. The realistic energy yield potential of GaAs-on-Si tandem solar cells: a theoretical case study.

    Science.gov (United States)

    Liu, Haohui; Ren, Zekun; Liu, Zhe; Aberle, Armin G; Buonassisi, Tonio; Peters, Ian Marius

    2015-04-06

    Si based tandem solar cells represent an alternative to traditional compound III-V multijunction cells as a promising way to achieve high efficiencies. A theoretical study on the energy yield of GaAs on Si (GaAs/Si) tandem solar cells is performed to assess their energy yield potential under realistic illumination conditions with varying spectrum. We find that the yield of a 4-terminal contact scheme with thick top cell is more than 15% higher than for a 2-terminal scheme. Furthermore, we quantify the main losses that occur for this type of solar cell under varying spectra. Apart from current mismatch, we find that a significant power loss can be attributed to low irradiance seen by the sub-cells. The study shows that despite non-optimal bandgap combination, GaAs/Si tandem solar cells have the potential to surpass 30% energy conversion efficiency.

  17. β+/EC decay rates of deformed neutron-deficient nuclei in the deformed QRPA with realistic interactions

    Directory of Open Access Journals (Sweden)

    Dongdong Ni

    2015-05-01

    Full Text Available The weak-decay (β+ and EC rates of neutron-deficient Kr, Sr, Zr, and Mo isotopes are investigated within the deformed quasiparticle random-phase approximation with realistic nucleon–nucleon interactions. The particle–particle and particle–hole channels of residual interactions are handled in large single-particle model spaces, based on the Brückner G-matrix with charge-dependent Bonn nucleon–nucleon forces. Contributions from allowed Gamow–Teller and Fermi transitions as well as first-forbidden transitions are calculated. The calculated half-lives show good agreement with the experimental data over a wide range of magnitude, from 10−2 to 107 s. Moreover, predictions of β-decay half-lives are made for some extremely proton-rich isotopes, which could be useful for future experiments.

  18. The effect of realistic nuclear charge distributions on isotope shifts and towards the extraction of higher order nuclear radial moments

    CERN Document Server

    Papoulia, A; Ekman, J

    2016-01-01

    Background: Atomic spectral lines from different isotopes display a small shift in energy, commonly referred to as the line isotope shift. One of the components of the isotope shift is the field shift, which depends on the extent and the shape of the nuclear charge density distribution. Purpose: To investigate how sensitive field shifts are with respect to variations in the nuclear size and shape and what information of nuclear charge distributions that can be extracted from measured field shifts. Methods: Nuclear properties are obtained from nuclear density functional theory calculations based on the Skyrme-Hartree-Fock-Bogoliubov approach. These results are combined with multiconfiguration Dirac-Hartree-Fock methods to obtain realistic field shifts. Results: Phenomena such as nuclear deformation and variations in the diffuseness of nuclear charge distributions give measurable contributions to the field shifts. Using a novel approach, we demonstrate the possibility to extract new information concerning the n...

  19. Policy guidance on threats to legislative interventions in public health: a realist synthesis

    Directory of Open Access Journals (Sweden)

    Owen Lesley

    2011-04-01

    Full Text Available Abstract Background Legislation is one of the most powerful weapons for improving population health and is often used by policy and decision makers. Little research exists to guide them as to whether legislation is feasible and/or will succeed. We aimed to produce a coherent and transferable evidence based framework of threats to legislative interventions to assist the decision making process and to test this through the 'case study' of legislation to ban smoking in cars carrying children. Methods We conceptualised legislative interventions as a complex social interventions and so used the realist synthesis method to systematically review the literature for evidence. 99 articles were found through searches on five electronic databases (MEDLINE, HMIC, EMBASE, PsychINFO, Social Policy and Practice and iterative purposive searching. Our initial searches sought any studies that contained information on smoking in vehicles carrying children. Throughout the review we continued where needed to search for additional studies of any type that would conceptually contribute to helping build and/or test our framework. Results Our framework identified a series of transferable threats to public health legislation. When applied to smoking bans in vehicles; problem misidentification; public support; opposition; and enforcement issues were particularly prominent threats. Our framework enabled us to understand and explain the nature of each threat and to infer the most likely outcome if such legislation were to be proposed in a jurisdiction where no such ban existed. Specifically, the micro-environment of a vehicle can contain highly hazardous levels of second hand smoke. Public support for such legislation is high amongst smokers and non-smokers and their underlying motivations were very similar - wanting to practice the Millian principle of protecting children from harm. Evidence indicated that the tobacco industry was not likely to oppose legislation and

  20. The Use of ICT in Kindergarten for Teaching Addition Based on Realistic Mathematics Education

    Science.gov (United States)

    Zaranis, Nicholas

    2016-01-01

    The purpose of this study is to investigate if information and communications technology (ICT) helps improve kindergarten students' basic mathematical achievement regarding addition. Our research compares the level of mathematical competence of the students taught using our ICT oriented learning method which specifically takes advantage of…

  1. A realist interpretation of quantum mechanics based on undecidability due to gravity

    Energy Technology Data Exchange (ETDEWEB)

    Gambini, Rodolfo; Garcia-Pintos, Luis Pedro [Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Igua 4225, CP 11400 Montevideo (Uruguay); Pullin, Jorge, E-mail: pullin@lsu.edu [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803-4001 (United States)

    2011-07-08

    We summarize several recent developments suggesting that solving the problem of time in quantum gravity leads to a solution of the measurement problem in quantum mechanics. This approach has been informally called 'the Montevideo interpretation'. In particular we discuss why definitions in this approach are not for all practical purposes (fapp) and how the problem of outcomes is resolved.

  2. Enabling Realistic Cross-Layer Analysis based on Satellite Physical Layer Traces

    CERN Document Server

    Kuhn, Nicolas; Lacan, Jerome; Boreli, Roksana; Bes, Caroline; Clarac, Laurence

    2012-01-01

    We present a solution to evaluate the performance of transport protocols as a function of link layer reliability schemes (i.e. ARQ, FEC and Hybrid ARQ) applied to satellite physical layer traces. As modelling such traces is complex and may require approximations, the use of real traces will minimise the potential for erroneous performance evaluations resulting from imperfect models. Our Trace Manager Tool (TMT) produces the corresponding link layer output, which is then used within the ns-2 network simulator via the additionally developed ns-2 interface module. We first present the analytical models for the link layer with bursty erasure packets and for the link layer reliability mechanisms with bursty erasures. Then, we present details of the TMT tool and our validation methodology, demonstrating that the selected performance metrics (recovery delay and throughput efficiency) exhibit a good match between the theoretical results and those obtained with TMT. Finally, we present results showing the impact of di...

  3. Squeezing based on nondegenerate frequency doubling internal to a realistic laser

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Tidemand-Lichtenberg, Peter; Buchhave, Preben

    2004-01-01

    We investigate theoretically the quantum fluctuations of the fundamental field in the output of a nondegenerate second-harmonic generation process occurring inside a laser cavity. Due to the nondegenerate character of the nonlinear medium, a field orthogonal to the laser field is for some operating...... conditions independent of the fluctuations produced by the laser medium. We show that this fact may lead to perfect squeezing for a certain polarization mode of the fundamental field. The experimental feasibility of the system is also discussed....

  4. Realistic Modeling and Animation of Human Body Based on Scanned Data

    Institute of Scientific and Technical Information of China (English)

    Yong-You Ma; Hui Zhang; Shou-Wei Jiang

    2004-01-01

    In this paper we propose a novel method for building animation model of real human body from surface scanned data.The human model is represented by a triangular mesh and described as a layered geometric model.The model consists of two layers: the control skeleton generating body animation from motion capture data,and the simplified surface model providing an efficient representation of the skin surface shape.The skeleton is generated automatically from surface scanned data using the feature extraction,and thena point-to-line mapping is used to map the surface model onto the underlying skeleton.The resulting model enables real-time and smooth animation by manipulation of the skeleton while maintaining the surface detail.Compared with earlier approach,the principal advantages of our approach are the automated generation of body control skeletons from the scanned data for real-time animation,and the automatic mapping and animation of the captured human surface shape.The human model constructed in this work can be used for applications of ergonomic design,garment CAD,real-time simulating humans in virtual reality environment and so on.

  5. From Workshops to Walkshops: Evaluating Mobile Locastion-Based Applications in Realistic Settings

    DEFF Research Database (Denmark)

    Korn, Matthias; Zander, Pär-Ola

    2010-01-01

    Many open questions on how to best observe the mobile user experience remain - at the stage of design time as well as use time. In this paper, we are focusing on the stage of design time and describe our experiences from evaluating a mobile application for citizen involvement in municipal land us...

  6. Efficient PDE based numerical estimation of credit and liquidity risk measures for realistic derivative portfolios

    NARCIS (Netherlands)

    de Graaf, C.S.L.

    2016-01-01

    In the Basel III accords in 2013, it was stated that financial institutions should charge Credit Value Adjustment (CVA) to their counterparties for (previously under-regulated) Over-The-Counter (OTC) trades. This CVA can be used to hedge a possible default of the counterparty. One important ingredie

  7. Gravity wave propagation in the realistic atmosphere based on a three-dimensional transfer function model

    Directory of Open Access Journals (Sweden)

    L. Sun

    2007-10-01

    Full Text Available In order to study the filter effect of the background winds on the propagation of gravity waves, a three-dimensional transfer function model is developed on the basis of the complex dispersion relation of internal gravity waves in a stratified dissipative atmosphere with background winds. Our model has successfully represented the main results of the ray tracing method, e.g. the trend of the gravity waves to travel in the anti-windward direction. Furthermore, some interesting characteristics are manifest as follows: (1 The method provides the distribution characteristic of whole wave fields which propagate in the way of the distorted concentric circles at the same altitude under the control of the winds. (2 Through analyzing the frequency and wave number response curve of the transfer function, we find that the gravity waves in a wave band of about 15–30 min periods and of about 200–400 km horizontal wave lengths are most likely to propagate to the 300-km ionospheric height. Furthermore, there is an obvious frequency deviation for gravity waves propagating with winds in the frequency domain. The maximum power of the transfer function with background winds is smaller than that without background winds. (3 The atmospheric winds may act as a directional filter that will permit gravity wave packets propagating against the winds to reach the ionospheric height with minimum energy loss.

  8. Computational dosimetry of induced electric fields during realistic movements in the vicinity of a 3 T MRI scanner.

    Science.gov (United States)

    Laakso, Ilkka; Kännälä, Sami; Jokela, Kari

    2013-04-21

    Medical staff working near magnetic resonance imaging (MRI) scanners are exposed both to the static magnetic field itself and also to electric currents that are induced in the body when the body moves in the magnetic field. However, there are currently limited data available on the induced electric field for realistic movements. This study computationally investigates the movement induced electric fields for realistic movements in the magnetic field of a 3 T MRI scanner. The path of movement near the MRI scanner is based on magnetic field measurements using a coil sensor attached to a human volunteer. Utilizing realistic models for both the motion of the head and the magnetic field of the MRI scanner, the induced fields are computationally determined using the finite-element method for five high-resolution numerical anatomical models. The results show that the time-derivative of the magnetic flux density (dB/dt) is approximately linearly proportional to the induced electric field in the head, independent of the position of the head with respect to the magnet. This supports the use of dB/dt measurements for occupational exposure assessment. For the path of movement considered herein, the spatial maximum of the induced electric field is close to the basic restriction for the peripheral nervous system and exceeds the basic restriction for the central nervous system in the international guidelines. The 99th percentile electric field is a considerably less restrictive metric for the exposure than the spatial maximum electric field; the former is typically 60-70% lower than the latter. However, the 99th percentile electric field may exceed the basic restriction for dB/dt values that can be encountered during tasks commonly performed by MRI workers. It is also shown that the movement-induced eddy currents may reach magnitudes that could electrically stimulate the vestibular system, which could play a significant role in the generation of vertigo-like sensations reported

  9. General description of KAERI LBLOCA realistic evaluation model (REM) for ECCS evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Yong; Lee, Young Jin; Chung, Bub Dong; Lee, Won Jae [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1994-06-01

    A realistic evaluation model (REM) for LBLOCA licensing calculation is developed for application to pressurezed ligh water reactors. The developmental aim of the KAERI-REM is to provide a systematic methodology that is simple in structure and to used and built upon sound logical reasoning, for improving the code capability to realistically describe the LBLOCA phenomena and for evaluating the associated uncertainties. The method strives to be faithful to the intention of being best-estimate, that is, the method aims to evaluate the best-estimate values and the associated uncertainties while complying to the requirements in the ECCS regulations. As a demonstration, KAERI-REM was applied to quantify the safety margin for LBLOCA for Kori 3 and 4 and appended to this report. (Author) 11 refs., 2 figs., 6 tabs.

  10. Realistic teenage fiction with a sexrelated theme: Readers’ responses to Slinger-slinger by Francois Bloemhof

    Directory of Open Access Journals (Sweden)

    M.N. Wiggill

    2004-07-01

    Full Text Available Francois Bloemhof submitted his novel for teenagers, “Slinger-slinger” for the Sanlam competition for youth fiction in 1996. Eventually this prizewinner in the beginners’ category was published in 1997. The main theme of “Slinger-slinger” is the sexual awakening and identity of teenagers. A study was undertaken to obtain the opinions of teenage readers about the success of “Slinger-slinger” as a whole, as well as to gauge the success of integrating sexual aspects in this novel. The study also served to obtain information about the reading needs of teenage readers with regard to realistic teenage fiction and teenage fiction with a sex-related theme. The findings of the study underlying this article indicated that the participating teenage readers regarded “Slinger-slinger” as successful and interesting, and that they would like to read more realistic Afrikaans teenage fiction such as “Slinger-slinger”.

  11. Realistic modelling of the seismic input Site effects and parametric studies

    CERN Document Server

    Romanelli, F; Vaccari, F

    2002-01-01

    We illustrate the work done in the framework of a large international cooperation, showing the very recent numerical experiments carried out within the framework of the EC project 'Advanced methods for assessing the seismic vulnerability of existing motorway bridges' (VAB) to assess the importance of non-synchronous seismic excitation of long structures. The definition of the seismic input at the Warth bridge site, i.e. the determination of the seismic ground motion due to an earthquake with a given magnitude and epicentral distance from the site, has been done following a theoretical approach. In order to perform an accurate and realistic estimate of site effects and of differential motion it is necessary to make a parametric study that takes into account the complex combination of the source and propagation parameters, in realistic geological structures. The computation of a wide set of time histories and spectral information, corresponding to possible seismotectonic scenarios for different sources and stru...

  12. Stability of strange stars (SS) derived from a realistic equation of state

    CERN Document Server

    Sinha, M N; Dey, M; Ray, S; Bhowmick, S; Sinha, Monika; Dey, Jishnu; Dey, Mira; Ray, Subharthi; Bhowmick, Siddhartha

    2002-01-01

    A realistic equation of state (EOS) leads to realistic strange stars (ReSS) which are compact in the mass radius plot, close to the Schwarzchild limiting line (Dey et al 1998). Many of the observed stars fit in with this kind of compactness, irrespective of whether they are X-ray pulsars, bursters or soft $\\gamma$ repeaters or even radio pulsars. We point out that a change in the radius of a star can be small or large, when its mass is increasing and this depends on the position of a particular star on the mass radius curve. We carry out a stability analysis against radial oscillations and compare with the EOS of other strange star (SS) models. We find that the ReSS is stable and an M-R region can be identified to that effect.

  13. Effect on Hyalella azteca after pulse exposure to environmentally realistic concentrations of permethrin

    DEFF Research Database (Denmark)

    Pedersen, Signe; Palmqvist, Annemette; Forbes, Valery E.

    realistic pulse exposure and concentration of a pyrethroid pesticide, permethrin, on the freshwater amphipod Hyalella azteca. Permethrin is a pyrethroid insecticide used in mosquito control and to control a wide range of insect pests on various crops and is known to be highly toxic to aquatic invertebrates....... H. azteca is widely distributed through North America where it is common as a food source for birds, fish and large invertebrates and is therefore considered as an ecologically important organism. In addition H. azteca has been extensively used as a test organism and is generally sensitive...... to contaminants. The toxicity of permethrin to H. azteca was first estimated in a 96 hour test with constant exposure. Then the toxicity and delayed effects after 10 days were tested with different concentrations and pulse lengths. The exposure pulses lasted for 1, 3 or 24 hours simulating a realistic run...

  14. Towards Behaviorly Realistic Simulations of the Stock Market Traders with a Soul

    CERN Document Server

    Solomon, S

    1999-01-01

    The price fluctuations in the financial markets are the result of the individual operations by many individual investors. However for many decades the finacial theory did not use directly this "microscopic representation". The difficulties preventing it were multiple but the main two are being solved recently with the advent of modern computer technology: - massive detailed data on the individual market operations became available. - "microscopic simulations" of the stock markets in terms of their individual participating agents allow a very realistic treatment of the problem. Consequently, we are now able to confront real market data with the results of simulating "microscopic" realistic models which include any desired features in the investors behavior: departures from rationality, herding effects, heterogenous investor-specific trading strategies etc. In this way we propose to understand, explain and may be predict the macroscopic market behavior.

  15. Numerical Modeling of Plasmonic Nanoantennas with Realistic 3D Roughness and Distortion

    Directory of Open Access Journals (Sweden)

    Vladimir P. Drachev

    2011-07-01

    Full Text Available Nanostructured plasmonic metamaterials, including optical nanoantenna arrays, are important for advanced optical sensing and imaging applications including surface-enhanced fluorescence, chemiluminescence, and Raman scattering. Although designs typically use ideally smooth geometries, realistic nanoantennas have nonzero roughness, which typically results in a modified enhancement factor that should be involved in their design. Herein we aim to treat roughness by introducing a realistic roughened geometry into the finite element (FE model. Even if the roughness does not result in significant loss, it does result in a spectral shift and inhomogeneous broadening of the resonance, which could be critical when fitting the FE simulations of plasmonic nanoantennas to experiments. Moreover, the proposed approach could be applied to any model, whether mechanical, acoustic, electromagnetic, thermal, etc, in order to simulate a given roughness-generated physical phenomenon.

  16. Toward realistic simulations of magneto-thermal winds from weakly-ionized protoplanetary disks

    CERN Document Server

    Gressel, Oliver

    2016-01-01

    Protoplanetary disks (PPDs) accrete onto their central T Tauri star via magnetic stresses. When the effect of ambipolar diffusion (AD) is included, and in the presence of a vertical magnetic field, the disk remains laminar between 1-5 au, and a magnetocentrifugal disk wind forms that provides an important mechanism for removing angular momentum. We present global MHD simulations of PPDs that include Ohmic resistivity and AD, where the time-dependent gas-phase electron and ion fractions are computed under FUV and X-ray ionization with a simplified recombination chemistry. To investigate whether the mass loading of the wind is potentially affected by the limited vertical extent of our existing simulations, we attempt to develop a model of a realistic disk atmosphere. To this end, by accounting for stellar irradiation and diffuse reprocessing of radiation, we aim at improving our models towards more realistic thermodynamic properties.

  17. Collective excitations in deformed sd-shell nuclei from realistic interactions

    CERN Document Server

    Erler, Bastian

    2014-01-01

    Background: Collective excitations of nuclei and their theoretical descriptions provide an insight into the structure of nuclei. Replacing traditional phenomenological interactions with unitarily transformed realistic nucleon-nucleon interactions increases the predictive power of the theoretical calculations for exotic or deformed nuclei. Purpose: Extend the application of realistic interactions to deformed nuclei and compare the performance of different interactions, including phenomenological interactions, for collective excitations in the sd-shell. Method: Ground-state energies and charge radii of 20-Ne, 28-Si and 32-S are calculated with the Hartree-Fock method. Transition strengths and transition densities are obtained in the Random Phase Approximation with explicit angular-momentum projection. Results: Strength distributions for monopole, dipole and quadrupole excitations are analyzed and compared to experimental data. Transition densities give insight into the structure of collective excitations in def...

  18. The Role Of Realistic Job Previews And Expectation Lowering Procedures For Expatriate Managers

    Directory of Open Access Journals (Sweden)

    Michael G. Harvey

    2011-07-01

    Full Text Available The purpose of this paper is to integrate research from the fields of economics, management and consumer satisfaction in an attempt to better understand the nature of expectations and the process of their formation in realistic job previews (RJP and expectations lowering procedures (ELP methods of influencing the development of realistic expectations about a position and an organization. The approach to the paper development is to initially review the research regarding met expectations and expectation formation, while later to introduce Expectation Disconfirmation Theory and relate it to both RJP and ELP.  Borrowing from the aforementioned diverse areas, a model is developed containing a continuum of expectations, disconfirmation, satisfaction and turnover intention that provides some insight, from a theoretical perspective, why RJP and ELP frequently result in successful and positive organizational outcomes.  “We fear things in proportion to our ignorance of them.”   (Titus Livius

  19. A realistic theory of health sector management. The case for critical realism.

    Science.gov (United States)

    Connelly, J

    2000-01-01

    To date the practice of health sector management has not been sufficiently theorised. An adequate theory should be able to answer the pre-eminent critique of managerial rationality and ethics mounted by Alasdair MacIntyre in After Virtue and should also offer robust analytical and ethical resources to identify and engage with the social, political, economic and moral issues underlying health sector management. Critical realism with its ontology of generative mechanisms, agency-structure relationships, valorisation of activity and ideology critique offers such resources in an empirically orientated but adequately theorised realist framework. Rather than negate MacIntyre, critical realism incorporates and transcends his key arguments regarding the rationality and ethics of management. This article introduces the main elements of critical realism and clears a conceptual space for the cumulation of critical realist case-studies and managerial craft knowledge.

  20. When threats foreign turn domestic : Two ways for distant realistic intergroup threats to carry over into local intolerance

    NARCIS (Netherlands)

    Bouman, Thijs; van Zomeren, Martijn; Otten, Sabine

    2015-01-01

    In times of economic downturn, perceived realistic intergroup threats (e.g., labour competition) often dominate political and media discourse. Although local outgroups (e.g., local immigrants) can be experienced as sources of realistic threats, we propose that such threats can also be perceived to b

  1. Critical Realism and Realist Review: Analyzing Complexity in Educational Restructuring and the Limits of Generalizing Program Theories Across Borders

    Science.gov (United States)

    De Souza, Denise E.

    2016-01-01

    This article focuses on the design of a critical realist review that deployed Bhaskar's resolution, redescribing, retroduction, eliminating, identifying, and correcting schema and Pawson and Tilley's Context-Mechanism-Outcome configuration underpinned by realist social theory. Methodologically, the review examined the relationship between…

  2. Realistic environmental mixtures of micropollutants in surface, drinking, and recycled water: herbicides dominate the mixture toxicity toward algae.

    Science.gov (United States)

    Tang, Janet Y M; Escher, Beate I

    2014-06-01

    Mixture toxicity studies with herbicides have focused on a few priority components that are most likely to cause environmental impacts, and experimental mixtures were often designed as equipotent mixtures; however, real-world mixtures are made up of chemicals with different modes of toxic action at arbitrary concentration ratios. The toxicological significance of environmentally realistic mixtures has only been scarcely studied. Few studies have simultaneously compared the mixture effect of water samples with designed reference mixtures comprised of the ratios of analytically detected concentrations in toxicity tests. In the present study, the authors address the effect of herbicides and other chemicals on inhibition of photosynthesis and algal growth rate. The authors tested water samples including secondary treated wastewater effluent, recycled water, drinking water, and storm water in the combined algae assay. The detected chemicals were mixed in the concentration ratios detected, and the biological effects of the water samples were compared with the designed mixtures of individual detected chemicals to quantify the fraction of effect caused by unknown chemicals. The results showed that herbicides dominated the algal toxicity in these environmentally realistic mixtures, and the contribution by the non-herbicides was negligible. A 2-stage model, which used concentration addition within the groups of herbicides and non-herbicides followed by the model of independent action to predict the mixture effect of the two groups, could predict the experimental mixture toxicity effectively, but the concentration addition model for herbicides was robust and sufficient for complex mixtures. Therefore, the authors used the bioanalytical equivalency concept to derive effect-based trigger values for algal toxicity for monitoring water quality in recycled and surface water. All water samples tested would be compliant with the proposed trigger values associated with the

  3. Analysis of the properties of SGRs and AXPs with realistic neutron star configurations

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Rafael C. R. de [ICRANet, Piazza della Repubblica 10, I-65122 Pescara (Italy); Coelho, Jaziel G. [Divisão de Astrofísica, Instituto Nacional de Pesquisas Espaciais, Avenida dos Astronautas 1758, 12227–010 São José dos Campos, SP (Brazil); Rueda, Jorge A.; Ruffini, Remo [ICRANet, Piazza della Repubblica 10, I-65122 Pescara (Italy); Dip. di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 5, I-00185 Rome (Italy); ICRANet-Rio, Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, 22290–180 Rio de Janeiro (Brazil); Malheiro, Manuel [Departamento de Física, Instituto Tecnológico de Aeronáutica, São José dos Campos, 12228-900, SP (Brazil)

    2015-12-17

    We show that nine soft gamma repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs) of the twenty three known sources can be described as rotation-powered canonical pulsars. To accomplish this we use realistic parameters of rotating neutron stars obtained from numerical integration of the self-consistent axisymmetric general relativistic equations of equilibrium. We present limits to the NS mass where the sources can be rotation-powered.

  4. Intelligible design a realistic approach to the philosophy and history of science

    CERN Document Server

    Gonzalo, Julio A

    2014-01-01

    This book provides realistic answers to hotly debated scientific topics: Science is about quantitative aspects of natural realities (physical, chemical, biological) but it is the result of human intellectual inquiry and therefore not "per se" materialistic. This book, with contributions from experts in physics, cosmology, mathematics, engineering, biology and genetics, covers timely and relevant topics such as the origin of the universe, the origin of life on Earth, the origin of man (intelligent life) and the origin of science.

  5. Perceived Strengths and Weaknesses of Highly Realistic Training and Live Tissue Training for Navy Corpsmen

    Science.gov (United States)

    2015-04-08

    medical populations, such as physicians, nurses , and Navy Fleet Surgical Teams. This training could be adapted and used to help newly formed...6. Hoang T, Kang J, LaPorta A, Makler V, Chalut C: Filling in the gaps of predeployment fleet surgical team training using a team- centered ...Naval Health Research Center Perceived Strengths and Weaknesses of Highly Realistic Training and Live Tissue Training for Navy Corpsmen Stephanie

  6. Fault-Tolerant Robot Programming through Simulation with Realistic Sensor Models

    OpenAIRE

    Axel Waggershauser; Thomas Braeunl; Andreas Koestler

    2008-01-01

    We introduce a simulation system for mobile robots that allows a realistic interaction of multiple robots in a common environment. The simulated robots are closely modeled after robots from the EyeBot family and have an identical application programmer interface. The simulation supports driving commands at two levels of abstraction as well as numerous sensors such as shaft encoders, infrared distance sensors, and compass. Simulation of on-board digital cameras via synthetic images allows the ...

  7. Two politicians in a realistic experiment: attraction, discrepancy, intensity of delivery, and attitude change

    OpenAIRE

    Wiegman, O.

    1985-01-01

    The leader of the Socialists in the Dutch Parliament and his Liberal opponent participated in this realistic experiment. Identical TV interviews with the two politicians were recorded and shown to subjects of both parties. The intensity of delivery was also varied: emotional versus rational. Our findgins indicated that the experimental interveiw changed the attitude of the subjects. In addition, support was found for a second hypothesis: Attitude change was greater for the attractive source f...

  8. What works for whom in pharmacist-led smoking cessation support: realist review

    OpenAIRE

    Greenhalgh, T.; Macfarlane, F; Steed, L; Walton, R.

    2016-01-01

    BACKGROUND: New models of primary care are needed to address funding and staffing pressures. We addressed the research question "what works for whom in what circumstances in relation to the role of community pharmacies in providing lifestyle interventions to support smoking cessation?" METHODS: This is a realist review conducted according to RAMESES standards. We began with a sample of 103 papers included in a quantitative review of community pharmacy intervention trials identified through sy...

  9. Evaluation of Highly Realistic Training for Navy Corpsmen: Results for Field Medical Training Battalion-West

    Science.gov (United States)

    2015-05-14

    actual amputees , some of whom were injured in combat. In this study, highly realistic training was implemented and evaluated in a sample of Navy...race groups. Nearly a quarter of participants (24%) self-reported “mixed or multiple races.” Description of the Training This project provided...scenarios and more time at MOUT. Do the training multiple times, so that everyone can be the corpsman. Lengthen the time so that more people get the chance

  10. Organizational mechanisms of inclusive growth: A critical realist perspective on scaling

    OpenAIRE

    Seelos, Christian; Mair, Johanna

    2010-01-01

    We investigate the challenge how the outcomes of innovation for inclusive growth, the novel organizational recipes, can be scaled to match the dimension of poverty. We conceptualize scaling as sustained event regularities between doing A and expected outcomes B. Building on a critical realist perspective, we develop an analytical framework of organizational closure and apply it to an extreme case, an organization with an inclusive growth model that has sustained event regularities for more th...

  11. Realistic three-generation models from SO(32) heterotic string theory

    CERN Document Server

    Abe, Hiroyuki; Otsuka, Hajime; Takano, Yasufumi

    2015-01-01

    We search for realistic supersymmetric standard-like models from SO(32) heterotic string theory on factorizable tori with multiple magnetic fluxes. Three chiral ganerations of quarks and leptons are derived from the adjoint and vector representations of SO(12) gauge groups embedded in SO(32) adjoint representation. Massless spectra of our models also include Higgs fields, which have desired Yukawa couplings to quarks and leptons at the tree-level.

  12. Realistic neurons can compute the operations needed by quantum probability theory and other vector symbolic architectures.

    Science.gov (United States)

    Stewart, Terrence C; Eliasmith, Chris

    2013-06-01

    Quantum probability (QP) theory can be seen as a type of vector symbolic architecture (VSA): mental states are vectors storing structured information and manipulated using algebraic operations. Furthermore, the operations needed by QP match those in other VSAs. This allows existing biologically realistic neural models to be adapted to provide a mechanistic explanation of the cognitive phenomena described in the target article by Pothos & Busemeyer (P&B).

  13. Ontological and Epistemological Foundations of Contemporary Pragmatic and Realistic Philosophy of Law

    Directory of Open Access Journals (Sweden)

    Mehmet Önal

    2015-12-01

    Full Text Available Pragmatism, which is one of the mainstreams of the philosophy of law, became popular in the UK especially after the 18th century on the basis of utilitarianism, and in the USA and Scandinavian countries after the 19th century on the basis of realism. Books on philosophy of law and legal theory discuss these philosophies under the headings of pragmatist and realist philosophies of law, and present it basically as a continuation of the British and American philosophy. However, the roots of these legal movements, which are epistemologically experimental and sensational, ontologically realistic, and ethically utilitarian and relativist should be sought in the whole history of philosophy especially in Ancient Greek Philosophy. Thus, to show this historical background, in the article, we try to return to the history of utilitarianism, pragmatism, realism and relativism in philosophical thought. In the last part of the article, with the help of examples taken from some assessments of contemporary pragmatist and realist philosophers of law, how pragmatism respond to today's complex and interactive social reality is discussed.

  14. "easyMine" – realistic and systematic mine detection simulation tooltion

    Directory of Open Access Journals (Sweden)

    U. Böttger

    2004-01-01

    Full Text Available Mine detection is to date mainly performed with metal detectors, although new methods for UXO detection are explored worldwide. The main problem for the mine detection to date is, that there exist some ideas of which sensor combinations could yield a high score, but until now there is no systematic analysis of mine detection methods together with realistic environmental conditions to conclude on a physically and technically optimized sensor combination. This gap will be removed by a project “easyMine" (Realistic and systematic Mine Detection Simulation Tool which will result in a simulation tool for optimizing land mine detection in a realistic mine field. The project idea for this software tool is presented, that will simulate the closed chain of mine detection, including the mine in its natural environment, the sensor, the evaluation and application of the measurements by an user. The tool will be modularly designed. Each chain link will be an independent, exchangeable sub- module and will describe a stand alone part of the whole mine detection procedure. The advantage of the tool will be the evaluation of very different kinds of sensor combinations in relation of their real potential for mine detection. Three detection methods (metal detector, GPR and imaging IR-radiometry will be explained to be introduced into the easyMine software tool in a first step. An actual example for land mine detection problem will be presented and approaches for solutions with easyMine will be shown.

  15. A GPU Tool for Efficient, Accurate, and Realistic Simulation of Cone Beam CT Projections

    CERN Document Server

    Jia, Xun; Cervino, Laura; Folkerts, Michael; Jiang, Steve B

    2012-01-01

    Simulation of x-ray projection images plays an important role in cone beam CT (CBCT) related research projects. A projection image contains primary signal, scatter signal, and noise. It is computationally demanding to perform accurate and realistic computations for all of these components. In this work, we develop a package on GPU, called gDRR, for the accurate and efficient computations of x-ray projection images in CBCT under clinically realistic conditions. The primary signal is computed by a tri-linear ray-tracing algorithm. A Monte Carlo (MC) simulation is then performed, yielding the primary signal and the scatter signal, both with noise. A denoising process is applied to obtain a smooth scatter signal. The noise component is then obtained by combining the difference between the MC primary and the ray-tracing primary signals, and the difference between the MC simulated scatter and the denoised scatter signals. Finally, a calibration step converts the calculated noise signal into a realistic one by scali...

  16. Environmental Protection as an Obstacle to Free Movement of Goods: Realist Jurisprudence in Articles 28 and 30 of the e.c. Treaty

    Directory of Open Access Journals (Sweden)

    Eric Engle

    2008-12-01

    Full Text Available Free trade and environmental protection are two norms that sometimes collide. The resolution of colliding norms can occur either using a formalist “descriptive” analysis, or using a “prescriptive” approach of legal realism. It may seem intuitive to imagine realism and formalism as mutually exclusive. However, this dualism is not entirely accurate. The realist-formalist dualism is unsatisfying because legal realism critiques the capricious nature of formalism only to replace it with likewise capricious methods of legal decision-making. Further, courts sometimes act as realists and at other times as formalists. Finally, many methods of legal interpretation may be considered either “formalist” or “realist.” This paper examines the conflict between free trade and environmental protection in E.C. law. It uses Articles 28 and 30 of the E.C. Treaty as a foil with which to draw out the distinctions and limits of both realism and formalism. A formal analysis of Articles 28 and 30 of the E.C. Treaty reveals a series of cases that struggle first to define waste as wares and then to determine the limitations that the free movement of goods imposes on environmental standards and vice versa. However, this unsatisfying formal analysis is not the only possible interpretation of the case law arising out of Articles 28 and 30. An analysis based on legal realism is also possible but not entirely satisfying. This paper concludes that the realist-formalist dualism, though tenable, does not solve the problem of capricious legal power.

  17. Realistic changes in seaweed biodiversity affect multiple ecosystem functions on a rocky shore.

    Science.gov (United States)

    Bracken, Matthew E S; Williams, Susan L

    2013-09-01

    Given current threats to biodiversity, understanding the effects of diversity changes on the functions and services associated with intact ecosystems is of paramount importance. However, limited realism in most biodiversity studies makes it difficult to link the large and growing body of evidence for important functional consequences of biodiversity change to real-world losses of biodiversity. Here, we explored two methods of incorporating realism into biodiversity research: (1) the use of two-, five-, and eight-species assemblages that mimicked those that we observed in surveys of seaweed biodiversity patterns on a northern California (USA) rocky shore and the explicit comparison of those assemblages to random assemblages compiled from the same local species pool; and (2) the measurement of two fundamental ecosystem functions, nitrate uptake and photosynthesis, both of which contribute to growth of primary producers. Specifically, we measured nitrate uptake rates of seaweed assemblages as a function of initial nitrate concentrations and photosynthetic rates as a function of irradiance levels for both realistic and random assemblages of seaweeds. We only observed changes in ecosystem functioning along a richness gradient for realistic assemblages, and both maximum nitrate uptake rates (V(max)) and photosynthetic light use efficiency values (alpha(p) = P(max)/I(K)) were higher in realistic assemblages than in random assemblages. Furthermore, the parameter affected by changes in richness depended on the function being measured. Both V(max) and alpha(p) declined with increasing richness in nonrandom assemblages due to a combination of species identity effects (for V(max) and overyielding effects (for both V(max) and alpha(p)). In contrast, neither nitrate uptake efficiency values (alpha(N) = V(max)/K(s)), nor maximum photosynthetic rates (Pmax) changed along the gradient in seaweed species richness. Furthermore, overyielding was only evident in realistic assemblages

  18. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Andrew M., E-mail: amhern@ucdavis.edu [Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States); Seibert, J. Anthony; Boone, John M. [Departments of Radiology and Biomedical Engineering, Biomedical Engineering Graduate Group, University of California Davis, Sacramento, California 95817 (United States)

    2015-11-15

    Purpose: Current dosimetry methods in mammography assume that the breast is comprised of a homogeneous mixture of glandular and adipose tissues. Three-dimensional (3D) dedicated breast CT (bCT) data sets were used previously to assess the complex anatomical structure within the breast, characterizing the statistical distribution of glandular tissue in the breast. The purpose of this work was to investigate the effect of bCT-derived heterogeneous glandular distributions on dosimetry in mammography. Methods: bCT-derived breast diameters, volumes, and 3D fibroglandular distributions were used to design realistic compressed breast models comprised of heterogeneous distributions of glandular tissue. The bCT-derived glandular distributions were fit to biGaussian functions and used as probability density maps to assign the density distributions within compressed breast models. The MCNPX 2.6.0 Monte Carlo code was used to estimate monoenergetic normalized mean glandular dose “DgN(E)” values in mammography geometry. The DgN(E) values were then weighted by typical mammography x-ray spectra to determine polyenergetic DgN (pDgN) coefficients for heterogeneous (pDgN{sub hetero}) and homogeneous (pDgN{sub homo}) cases. The dependence of estimated pDgN values on phantom size, volumetric glandular fraction (VGF), x-ray technique factors, and location of the heterogeneous glandular distributions was investigated. Results: The pDgN{sub hetero} coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgN{sub homo} coefficients for the Mo–Mo and W–Rh x-ray spectra, respectively, across all phantom sizes and VGFs when the glandular distributions were centered within the breast phantom in the coronal plane. At constant breast size, increasing VGF from 7.3% to 19.1% lead to a reduction in pDgN{sub hetero} relative to pDgN{sub homo} of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the

  19. Mechanisms underpinning interventions to reduce sexual violence in armed conflict: A realist-informed systematic review.

    Science.gov (United States)

    Spangaro, Jo; Adogu, Chinelo; Zwi, Anthony B; Ranmuthugala, Geetha; Davies, Gawaine Powell

    2015-01-01

    Sexual violence is recognised as a widespread consequence of armed conflict and other humanitarian crises. The limited evidence in literature on interventions in this field suggests a need for alternatives to traditional review methods, particularly given the challenges of undertaking research in conflict and crisis settings. This study employed a realist review of the literature on interventions with the aim of identifying the mechanisms at work across the range of types of intervention. The realist approach is an exploratory and theory-driven review method. It is well suited to complex interventions as it takes into account contextual factors to identify mechanisms that contribute to outcomes. The limited data available indicate that there are few deterrents to sexual violence in crises. Four main mechanisms appear to contribute to effective interventions: increasing the risk to offenders of being detected; building community engagement; ensuring community members are aware of available help for and responses to sexual violence; and safe and anonymous systems for reporting and seeking help. These mechanisms appeared to contribute to outcomes in multiple-component interventions, as well as those relating to gathering firewood, codes of conduct for personnel and legal interventions. Drawing on pre-existing capacity or culture in communities is an additional mechanism which should be explored. Though increasing the risk to offenders of being detected was assumed to be a central mechanism in deterring sexual violence, the evidence suggests that this mechanism operated only in interventions focused on gathering firewood and providing alternative fuels. The other three mechanisms appeared important to the likelihood of an intervention being successful, particularly when operating simultaneously. In a field where robust outcome research remains likely to be limited, realist methods provide opportunities to understand existing evidence. Our analysis identifies the

  20. The effect of a realistic thermal diffusivity on numerical model of a subducting slab

    Science.gov (United States)

    Maierova, P.; Steinle-Neumann, G.; Cadek, O.

    2010-12-01

    A number of numerical studies of subducting slab assume simplified (constant or only depth-dependent) models of thermal conductivity. The available mineral physics data indicate, however, that thermal diffusivity is strongly temperature- and pressure-dependent and may also vary among different mantle materials. In the present study, we examine the influence of realistic thermal properties of mantle materials on the thermal state of the upper mantle and the dynamics of subducting slabs. On the basis of the data published in mineral physics literature we compile analytical relationships that approximate the pressure and temperature dependence of thermal diffusivity for major mineral phases of the mantle (olivine, wadsleyite, ringwoodite, garnet, clinopyroxenes, stishovite and perovskite). We propose a simplified composition of mineral assemblages predominating in the subducting slab and the surrounding mantle (pyrolite, mid-ocean ridge basalt, harzburgite) and we estimate their thermal diffusivity using the Hashin-Shtrikman bounds. The resulting complex formula for the diffusivity of each aggregate is then approximated by a simpler analytical relationship that is used in our numerical model as an input parameter. For the numerical modeling we use the Elmer software (open source finite element software for multiphysical problems, see http://www.csc.fi/english/pages/elmer). We set up a 2D Cartesian thermo-mechanical steady-state model of a subducting slab. The model is partly kinematic as the flow is driven by a boundary condition on velocity that is prescribed on the top of the subducting lithospheric plate. Reology of the material is non-linear and is coupled with the thermal equation. Using the realistic relationship for thermal diffusivity of mantle materials, we compute the thermal and flow fields for different input velocity and age of the subducting plate and we compare the results against the models assuming a constant thermal diffusivity. The importance of the

  1. How to cheat in Photoshop CS6 the art of creating realistic photomontages

    CERN Document Server

    Caplin, Steve

    2013-01-01

    With enough charm and wit to make learning Photoshop anything but taxing, Steve Caplin delivers the next instalment of the How to Cheat series, containing all the techniques you need to create and master the art of photomontage. Delivered in easy to follow step-by-step tutorials How to Cheat in Photoshop covers all the basics of selections and layers before moving onto top tricks and techniques for creating realistic works of art for business, pleasure, or something in between. An accompanying DVD is packed full of practice images and tutorial movies for you to working along

  2. Is China becoming more Aggressive? A Neo-classical Realist Analysis

    DEFF Research Database (Denmark)

    Sørensen, Camilla T. N.

    2013-01-01

    In this article I seek to improve the dominant neorealist analysis of China's rise. I offer a neoclassical realist analytical framework in order to identify the influence of certain Chinese domestic developments and priorities on Chinese foreign and security policy behavior. Rather than reflecting...... a more self-confident and aggressive China, developments in Chinese foreign and security policy in recent years reveal an internally conflicted, inward-looking, and reactive China not yet ready for its new international role. Beijing is uncertain how to manage the challenges and the inevitable tension......, both domestically and internationally, arising from China's rapid development....

  3. Rotation curve fitting and its fatal attraction to cores in realistically simulated galaxy observations

    CERN Document Server

    Pineda, Juan C B; Springel, Volker; de Oliveira, Claudia Mendes

    2016-01-01

    We study the role of systematic effects in observational studies of the core/cusp problem under the minimum disc approximation using a suite of high-resolution (25-pc softening length) hydrodynamical simulations of dwarf galaxies. We mimic kinematical observations in a realistic manner at different distances and inclinations, and fit the resulting rotation curves with two analytical models commonly used to differentiate cores from cusps in the dark matter distribution. We find that the cored pseudo-isothermal sphere (P-ISO) model is often strongly favoured by the reduced $\\chi^2_\

  4. Photodisintegration of light nuclei for testing a correlated realistic interaction in the continuum

    CERN Document Server

    Bacca, S

    2006-01-01

    An exact calculation of the photodisintegration cross section of 3H, 3He and 4He is performed using as interaction the correlated Argonne V18 potential, constructed within the Unitary Correlation Operator Method (VUCOM). Calculations are carried out using the Lorentz Integral Transform method in conjunction with an hyperspherical harmonics basis expansion. A comparison with other realistic potentials and with available experimental data is discussed. The VUCOM potential leads to a very similar description of the cross section as the Argonne V18 interaction with the inclusion of the Urbana IX three-body force for photon energies 45< w < 120 MeV, while larger differences are found close to threshold.

  5. Gaussian bosonic synergy: quantum communication via realistic channels of zero quantum capacity

    CERN Document Server

    Smith, Graeme; Yard, Jon

    2011-01-01

    As with classical information, error-correcting codes enable reliable transmission of quantum information through noisy or lossy channels. In contrast to the classical theory, imperfect quantum channels exhibit a strong kind of synergy: there exist pairs of discrete memoryless quantum channels, each of zero quantum capacity, which acquire positive quantum capacity when used together. Here we show that this "superactivation" phenomenon also occurs in the more realistic setting of optical channels with attenuation and Gaussian noise. This paves the way for its experimental realization and application in real-world communications systems.

  6. Leptogenesis in the Light of Super-Kamiokande Data and a Realistic String Model

    CERN Document Server

    Ellis, Jonathan Richard; Nanopoulos, Dimitri V; Ellis, John

    1999-01-01

    We discuss leptogenesis in the light of indications of neutrino masses and mixings from Super-Kamiokande and other data on atmospheric neutrinos, as well as the solar neutrino deficit. Neutrino masses and mixings consistent with these data may produce in a natural and generic way a lepton asymmetry that is suffient to provide the observed baryon asymmetry, after processing via non-perturbative electroweak effects. We illustrate this discussion in the framework of the string-derived flipped SU(5) model, using particle assignments and choices of vacuum parameters that are known to give realistic masses to quarks and charged leptons. We display one scenario for neutrino masses that also accommodates leptogenesis.

  7. Realistic simulation of laser range finder behavior in a smoky environment

    OpenAIRE

    Formsma, O.; Dijkshoorn, N.; van Noort, S.; de Visser, A.

    2011-01-01

    The Urban Search and Rescue Simulation used for RoboCup lacks realistic response of laser range finders on smoke. In this paper, the behavior of a Hokuyo and Sick laser range finder in a smoky environment is studied. The behavior of the lasers is among others a function of the visibility level, and in this article this function is quantified into an explicit model. This model is implemented in a simulation environment which is the basis of the Virtual Robot competition of the RoboCup Rescue L...

  8. Performance Analysis of Relays in LTE for a Realistic Suburban Deployment Scenario

    DEFF Research Database (Denmark)

    Coletti, Claudio; Mogensen, Preben; Irmer, Ralf

    2011-01-01

    -effectiveness have been widely investigated in the literature, considering mainly statistical deployment scenarios, like regular networks with uniform traffic distribution. This paper is envisaged to illustrate the performances of different relay technologies (In-Band/Out-band) in a realistic suburban network......Relays are likely to play an important role in the deployment of Beyond 3G networks, such as LTE-Advanced, thanks to the possibility of effectively extending Macro network coverage and fulfilling the expected high data-rate requirements. Up until now, the relay technology potential and its cost...... of a lower frequency carrier at the Macro layer guarantee better network coverage and capacity improvements....

  9. Realistic calculations of nuclear disappearance lifetimes induced by n nmacr oscillations

    Science.gov (United States)

    Friedman, E.; Gal, A.

    2008-07-01

    Realistic calculations of nuclear disappearance lifetimes induced by n nmacr oscillations are reported for oxygen and iron, using nmacr nuclear potentials derived from a recent comprehensive analysis of pmacr atomic X-ray and radiochemical data. A lower limit τn nmacr >3.3×108s on the n nmacr oscillation time is derived from the Super-Kamiokande I new lower limit Td(O)>1.77×1032yr on the neutron lifetime in oxygen. Antineutron scattering lengths in carbon and nickel, needed in trap experiments using ultracold neutrons, are calculated from updated Nmacr optical potentials at threshold, with results shown to be largely model independent.

  10. Towards a realistic interpretation of quantum physics providing a physical model of the natural world

    CERN Document Server

    Santos, Emilio

    2012-01-01

    It is stressed the advantage of a realistic interpretation of quantum mechanics providing a physical model of the quantum world. After some critical comments on the most popular interpretations, the difficulties for a model are pointed out and possible solutions proposed. In particular the existence of discrete states, the quantum jumps, the alleged lack of objective properties, measurement theory, the probabilistic character of quantum physics, the wave-particle duality and the Bell inequalities are commented. It is conjectured that an intuitive picture of the quantum world could be obtained compatible with the quantum predictions for actual experiments, although maybe incompatible with alleged predictions for ideal, unrealizable, experiments.

  11. SUPPORTING FAMILIES OF FOREIGN FIGHTERS. A REALISTIC APPROACH FOR MEASURING THE EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Amy-Jane Gielen

    2015-03-01

    disengagement work. Moreover, family members such as brothers, sisters, cousins, but also peers, form an at-risk group of travelling to Syria. Supporting families and the broader professional network of the family (such as school teachers should enable practitioners and family members to act upon early warning signals and prevent travel of other family members or peers; Providing family support can work as a very powerful narrative for foreign fighters to come home. A lot of foreign fighters are afraid of returning because they fear prosecution or Guantanamo Bay. In one country were family and individual support was offered on a local level, parents spread the word that ‘the government was there to help them’. This message found its way back to the foreign fighters in Syria, providing a powerful narrative and highlighting the internal/external and local/global dimension of providing support; Finally, foreign fighters cause a lot of grief, anxiety, despair and upset for family members to the point they are no longer actively able to participate in society (not able to work etc. for which psychological counselling is essential. This article will focus on family support as part of counter-radicalisation policy. How can its effectiveness be measured? To answer this question, this article will draw on realistic evaluation which revolves around ‘what works, for who, in which context and how? (Pawson & Tilley 1997. It will discuss the different forms and merits of family support across Europe by drawing upon the lessons learned of practitioners engaging in family support within the Radicalisation Awareness Network (RAN including two case studies in which support was provided offered to families of foreign fighters by myself. Based on these practitioner experiences hypotheses on family support as part of a counter-radicalisation strategy are developed which in turn could be used for empirical testing.

  12. What makes health demand-side financing schemes work in low- and middle-income countries? A realist review

    Directory of Open Access Journals (Sweden)

    Saji S. Gopalan

    2014-12-01

    Full Text Available This realist review explored causal pathways of the possible consumer effects of health sector demand-side financial (DSF incentives, their contextual factors and mechanisms in low-and-middle-income countries. We searched six electronic data bases and identified 659 abstracts with different evaluation designs. Based on methodological rigor and content relevance, only 24 studies published up to April 2013 were selected for the final review. A conceptual framework consisting of various program theories on potential context-mechanism-outcome (C-M-O configuration of DSF initiative was designed, tested and adapted during the review. Synthesized results were presented as a C-M-O configuration for each of the consumer-side effect. DSF was effective to improve health seeking behaviour considerably and health status to some extent. The causal pathway of DSF’s functioning and effectiveness was not linear. Key demand-side contextual factors which affected DSF’s consumer-side effects were background characteristics of the beneficiaries including their socio-cultural beliefs, motivations, and level of health awareness. At the supply-side, service availability status and provider incentives were contextual determinants. The mechanisms which enabled the interaction of contextual influence were consumer and provider accountability and consumer trust on providers. In order to enhance DSF programs’ effectiveness, their design and implementation should carefully consider the potential contextual elements that may influence the causal pathways.

  13. The Monte Carlo code CSSE for the simulation of realistic thermal neutron sensor devices for Humanitarian Demining

    Energy Technology Data Exchange (ETDEWEB)

    Palomba, M. E-mail: maurizio.palomba@ba.infn.it; D' Erasmo, G.; Pantaleo, A

    2003-02-11

    The CSSE code, a GEANT3-based Monte Carlo simulation program, has been developed in the framework of the EXPLODET project (Nucl. Instr. and Meth. A 422 (1999) 918) with the aim to simulate experimental set-ups employed in Thermal Neutron Analysis (TNA) for the landmines detection. Such a simulation code appears to be useful for studying the background in the {gamma}-ray spectra obtained with this technique, especially in the region where one expects to find the explosive signature (the {gamma}-ray peak at 10.83 MeV coming from neutron capture by nitrogen). The main features of the CSSE code are introduced and original innovations emphasized. Among the latter, an algorithm simulating the time correlation between primary particles, according with their time distributions is presented. Such a correlation is not usually achievable within standard GEANT-based codes and allows to reproduce some important phenomena, as the pulse pile-up inside the NaI(Tl) {gamma}-ray detector employed, producing a more realistic detector response simulation. CSSE has been successfully tested by reproducing a real nuclear sensor prototype assembled at the Physics Department of Bari University.

  14. The Monte Carlo code CSSE for the simulation of realistic thermal neutron sensor devices for Humanitarian Demining

    Science.gov (United States)

    Palomba, M.; D'Erasmo, G.; Pantaleo, A.

    2003-02-01

    The CSSE code, a GEANT3-based Monte Carlo simulation program, has been developed in the framework of the EXPLODET project (Nucl. Instr. and Meth. A 422 (1999) 918) with the aim to simulate experimental set-ups employed in Thermal Neutron Analysis (TNA) for the landmines detection. Such a simulation code appears to be useful for studying the background in the γ-ray spectra obtained with this technique, especially in the region where one expects to find the explosive signature (the γ-ray peak at 10.83 MeV coming from neutron capture by nitrogen). The main features of the CSSE code are introduced and original innovations emphasized. Among the latter, an algorithm simulating the time correlation between primary particles, according with their time distributions is presented. Such a correlation is not usually achievable within standard GEANT-based codes and allows to reproduce some important phenomena, as the pulse pile-up inside the NaI(Tl) γ-ray detector employed, producing a more realistic detector response simulation. CSSE has been successfully tested by reproducing a real nuclear sensor prototype assembled at the Physics Department of Bari University.

  15. On the Foundations of the Brussels Operational-Realistic Approach to Cognition

    Directory of Open Access Journals (Sweden)

    Diederik eAerts

    2016-05-01

    Full Text Available The scientific community is becoming more and more interested in the research that applies the mathematical formalism of quantum theory to model human decision-making. In this paper, we provide the theoretical foundations of the quantum approach to cognition that we developed in Brussels. These foundations rest on the results of two decade studies on the axiomatic and operational-realistic approaches to the foundations of quantum physics. The deep analogies between the foundations of physics and cognition lead us to investigate the validity of quantum theory as a general and unitary framework for cognitive processes, and the empirical success of the Hilbert space models derived by such investigation provides a strong theoretical confirmation of this validity. However, two situations in the cognitive realm, `question order effects' and `response replicability', indicate that even the Hilbert space framework could be insufficient to reproduce the collected data. This does not mean that the mentioned operational-realistic approach would be incorrect, but simply that a larger class of measurements would be in force in human cognition, so that an extended quantum formalism may be needed to deal with all of them. As we will explain, the recently derived `extended Bloch representation' of quantum theory (and the associated `general tension-reduction' model precisely provides such extended formalism, while remaining within the same unitary interpretative framework.

  16. On the Foundations of the Brussels Operational-Realistic Approach to Cognition

    Science.gov (United States)

    Aerts, Diederik; Sassoli de Bianchi, Massimiliano; Sozzo, Sandro

    2016-05-01

    The scientific community is becoming more and more interested in the research that applies the mathematical formalism of quantum theory to model human decision-making. In this paper, we provide the theoretical foundations of the quantum approach to cognition that we developed in Brussels. These foundations rest on the results of two decade studies on the axiomatic and operational-realistic approaches to the foundations of quantum physics. The deep analogies between the foundations of physics and cognition lead us to investigate the validity of quantum theory as a general and unitary framework for cognitive processes, and the empirical success of the Hilbert space models derived by such investigation provides a strong theoretical confirmation of this validity. However, two situations in the cognitive realm, `question order effects' and `response replicability', indicate that even the Hilbert space framework could be insufficient to reproduce the collected data. This does not mean that the mentioned operational-realistic approach would be incorrect, but simply that a larger class of measurements would be in force in human cognition, so that an extended quantum formalism may be needed to deal with all of them. As we will explain, the recently derived `extended Bloch representation' of quantum theory (and the associated `general tension-reduction' model) precisely provides such extended formalism, while remaining within the same unitary interpretative framework.

  17. Designing virtual audiences for fear of public speaking training - an observation study on realistic nonverbal behavior.

    Science.gov (United States)

    Poeschl, Sandra; Doering, Nicola

    2012-01-01

    Virtual Reality technology offers great possibilities for Cognitive Behavioral Therapy of fear of public speaking: Clients can be exposed to virtual fear-triggering stimuli (exposure) and are able to role-play in virtual environments, training social skills to overcome their fear. Usually, prototypical audience behavior (neutral, social and anti-social) serves as stimulus in virtual training sessions, although there is significant lack of theoretical basis on typical audience behavior. The study presented deals with the design of a realistic virtual presentation scenario. An audience (consisting of n=18 men and women) in an undergraduate seminar was observed during three frontal lecture sessions. Behavior frequency of four nonverbal dimensions (eye contact, facial expression, gesture, and posture) was rated by means of a quantitative content analysis. Results show audience behavior patterns which seem to be typical in frontal lecture contexts, like friendly and neutral face expressions. Additionally, combined and even synchronized behavioral patterns between participants who sit next to each other (like turning to the neighbor and start talking) were registered. The gathered data serve as empirical design basis for a virtual audience to be used in virtual training applications that stimulate the experiences of the participants in a realistic manner, thereby improving the experienced presence in the training application.

  18. Recent advances on thermohydraulic simulation of HTR-10 nuclear reactor core using realistic CFD approach

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Alexandro S., E-mail: alexandrossilva@ifba.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia da Bahia (IFBA), Vitoria da Conquista, BA (Brazil); Mazaira, Leorlen Y.R., E-mail: leored1984@gmail.com, E-mail: cgh@instec.cu [Instituto Superior de Tecnologias y Ciencias Aplicadas (INSTEC), La Habana (Cuba); Dominguez, Dany S.; Hernandez, Carlos R.G., E-mail: alexandrossilva@gmail.com, E-mail: dsdominguez@gmail.com [Universidade Estadual de Santa Cruz (UESC), Ilheus, BA (Brazil). Programa de Pos-Graduacao em Modelagem Computacional; Lira, Carlos A.B.O., E-mail: cabol@ufpe.br [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2015-07-01

    High-temperature gas-cooled reactors (HTGRs) have the potential to be used as possible energy generation sources in the near future, owing to their inherently safe performance by using a large amount of graphite, low power density design, and high conversion efficiency. However, safety is the most important issue for its commercialization in nuclear energy industry. It is very important for safety design and operation of an HTGR to investigate its thermal-hydraulic characteristics. In this article, it was performed the thermal-hydraulic simulation of compressible flow inside the core of the pebble bed reactor HTR (High Temperature Reactor)-10 using Computational Fluid Dynamics (CFD). The realistic approach was used, where every closely packed pebble is realistically modelled considering a graphite layer and sphere of fuel. Due to the high computational cost is impossible simulate the full core; therefore, the geometry used is a FCC (Face Centered Cubic) cell with the half height of the core, with 21 layers and 95 pebbles. The input data used were taken from the thermal-hydraulic IAEA Bechmark. The results show the profiles of velocity and temperature of the coolant in the core, and the temperature distribution inside the pebbles. The maximum temperatures in the pebbles do not exceed the allowable limit for this type of nuclear fuel. (author)

  19. Revised rate coefficients for H$_2$ and H$^-$ destruction by realistic stellar spectra

    CERN Document Server

    Agarwal, Bhaskar

    2014-01-01

    Understanding the processes that can destroy H$_2$ and H$^-$ species is quintessential in governing the formation of the first stars, black holes and galaxies. In this study we compute the reaction rate coefficients for H$_2$ photo--dissociation by Lyman--Werner photons ($11.2 - 13.6$ eV), and H$^-$ photo--detachment by 0.76 eV photons emanating from self-consistent stellar populations that we model using publicly available stellar synthesis codes. So far studies that include chemical networks for the formation of molecular hydrogen take these processes into account by assuming that the source spectra can be approximated by a power-law dependency or a black-body spectrum at 10$^4$ or $10^5$ K. We show that using spectra generated from realistic stellar population models can alter the reaction rates for photo-dissociation, $\\rm k_{\\rm{di}}$, and photo-detachment, $\\rm k_{\\rm{de}}$, significantly. In particular, $\\rm k_{\\rm{de}}$ can be up to $\\sim 2-4$ orders of magnitude lower in the case of realistic stellar...

  20. The Realistic Fallacy, or: The Conception of Literary Narrative Fiction in Analytic Aesthetics

    Directory of Open Access Journals (Sweden)

    Jukka Mikkonen

    2009-03-01

    Full Text Available In this paper, my aim is to show that in Anglo-American analytic aesthetics, the conception of narrative fiction is in general realistic and that it derives from philosophical theories of fiction-making, the act of producing works of literary narrative fiction. I shall firstly broadly show the origins of the problem and illustrate how the so-called realistic fallacy – the view which maintains that fictions consist of propositions which represent the fictional world “as it is” – is committed through the history of philosophical approaches to literature in the analytic tradition. Secondly, I shall show how the fallacy that derives from the 20th Century philosophy of language manifests itself in contemporary analytic aesthetics, using Peter Lamarque and Stein Haugom Olsen’s influential and well-known Gricean make-believe theory of fiction as an example. Finally, I shall sketch how the prevailing Gricean make-believe theories should be modified in order to reach the literary-fictive use of language and to cover fictions broader than Doyle’s stories and works alike.

  1. Simulation Using Realistic Spray Cooling for the Continuous Casting of Multi-component Steel

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A three-dimensional heat transfer model for continuous steel slab casting has been developed with realistic spray cooling patterns and a coupled microsegregation solidification model that calculates the solidification path for multicomponent steels. Temperature and composition dependent properties are implemented in a database for 15 chemical species. Considerable effort is made to accurately model the spray cooling heat transfer. Each spray nozzle position and distribution is considered, including variations of the spray patterns with flow rate, and spray overlap. Nozzle type, layout, nozzle-to-slab distance, and spray span and flux are variable. Natural convection, thermal radiation and contact cooling of individual rolls are computed. The present model provides more comprehensive information and realistic slab surface temperatures than results from a model using the "averaged" treatment of boundary conditions.Cooling operating conditions and parameters of individual spray nozzles can be analyzed to optimize nozzle spray distribution, improve product quality, and troubleshoot issues such as nozzle clogging that may arise during production.One spray cooling correlation is used for the entire machine, achieving as good or better agreement with surface temperature measurements than was found previously for the model using an "averaged" treatment of boundary conditions and using three machine-segment-dependent correlations.

  2. HackAttack: Game-Theoretic Analysis of Realistic Cyber Conflicts

    Energy Technology Data Exchange (ETDEWEB)

    Ferragut, Erik M [ORNL; Brady, Andrew C [Jefferson Middle School, Oak Ridge, TN; Brady, Ethan J [Oak Ridge High School, Oak Ridge, TN; Ferragut, Jacob M [Oak Ridge High School, Oak Ridge, TN; Ferragut, Nathan M [Oak Ridge High School, Oak Ridge, TN; Wildgruber, Max C [ORNL

    2016-01-01

    Game theory is appropriate for studying cyber conflict because it allows for an intelligent and goal-driven adversary. Applications of game theory have led to a number of results regarding optimal attack and defense strategies. However, the overwhelming majority of applications explore overly simplistic games, often ones in which each participant s actions are visible to every other participant. These simplifications strip away the fundamental properties of real cyber conflicts: probabilistic alerting, hidden actions, unknown opponent capabilities. In this paper, we demonstrate that it is possible to analyze a more realistic game, one in which different resources have different weaknesses, players have different exploits, and moves occur in secrecy, but they can be detected. Certainly, more advanced and complex games are possible, but the game presented here is more realistic than any other game we know of in the scientific literature. While optimal strategies can be found for simpler games using calculus, case-by-case analysis, or, for stochastic games, Q-learning, our more complex game is more naturally analyzed using the same methods used to study other complex games, such as checkers and chess. We define a simple evaluation function and employ multi-step searches to create strategies. We show that such scenarios can be analyzed, and find that in cases of extreme uncertainty, it is often better to ignore one s opponent s possible moves. Furthermore, we show that a simple evaluation function in a complex game can lead to interesting and nuanced strategies.

  3. Efficient temperature-dependent Green's functions methods for realistic systems: compact grids for orthogonal polynomial transforms

    CERN Document Server

    Kananenka, Alexei A; Zgid, Dominika

    2015-01-01

    The temperature-dependent Matsubara Green's function that is used to describe temperature-dependent behavior is expressed on a numerical grid. While such a grid usually has a couple of hundred points for low-energy model systems, for realistic systems in large basis sets the size of an accurate grid can be tens of thousands of points, constituting a severe computational and memory bottleneck. In this paper, we determine efficient imaginary time grids for the temperature-dependent Matsubara Green's function formalism that can be used for calculations on realistic systems. We show that due to the use of orthogonal polynomial transform, we can restrict the imaginary time grid to few hundred points and reach micro-Hartree accuracy in the electronic energy evaluation. Moreover, we show that only a limited number of orthogonal polynomial expansion coefficients are necessary to preserve accuracy when working with a dual representation of Green's function or self-energy and transforming between the imaginary time and...

  4. A Modern Syllogistic Method in Intuitionistic Fuzzy Logic with Realistic Tautology.

    Science.gov (United States)

    Rushdi, Ali Muhammad; Zarouan, Mohamed; Alshehri, Taleb Mansour; Rushdi, Muhammad Ali

    2015-01-01

    The Modern Syllogistic Method (MSM) of propositional logic ferrets out from a set of premises all that can be concluded from it in the most compact form. The MSM combines the premises into a single function equated to 1 and then produces the complete product of this function. Two fuzzy versions of MSM are developed in Ordinary Fuzzy Logic (OFL) and in Intuitionistic Fuzzy Logic (IFL) with these logics augmented by the concept of Realistic Fuzzy Tautology (RFT) which is a variable whose truth exceeds 0.5. The paper formally proves each of the steps needed in the conversion of the ordinary MSM into a fuzzy one. The proofs rely mainly on the successful replacement of logic 1 (or ordinary tautology) by an RFT. An improved version of Blake-Tison algorithm for generating the complete product of a logical function is also presented and shown to be applicable to both crisp and fuzzy versions of the MSM. The fuzzy MSM methodology is illustrated by three specific examples, which delineate differences with the crisp MSM, address the question of validity values of consequences, tackle the problem of inconsistency when it arises, and demonstrate the utility of the concept of Realistic Fuzzy Tautology.

  5. Time-variability of alpha from realistic models of Oklo reactors

    CERN Document Server

    Gould, C R; Lamoreaux, S K

    2006-01-01

    We reanalyze Oklo $^{149}$Sm data using realistic models of the natural nuclear reactors. Disagreements among recent Oklo determinations of the time evolution of $\\alpha$, the electromagnetic fine structure constant, are shown to be due to different reactor models, which led to different neutron spectra used in the calculations. We use known Oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models. Two Oklo reactors, RZ2 and RZ10, were modeled with MCNP. The resulting neutron spectra were used to calculate the change in the $^{149}$Sm effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-meV resonance. We independently deduce ancient $^{149}$Sm effective cross sections, and use these values to set limits on the time-variation of $\\alpha$. Our study resolves a contradictory situation with previous Oklo $\\alpha$-results. Our suggested $2 \\sigma$ bound on a possible time variation of $\\alpha$ over two billion years is stringent: $ -...

  6. Time-variability of alpha from realistic models of Oklo reactors

    Science.gov (United States)

    Gould, Chris; Sharapov, Eduard; Lamoreaux, Steve

    2006-10-01

    We reanalyze Oklo ^149Sm data using realistic models of the natural nuclear reactors. Disagreements among recent Oklo determinations of the time evolution of α, the electromagnetic fine structure constant, are shown to be due to different reactor models, which led to different neutron spectra used in the calculations. We use known Oklo reactor epithermal spectral indices as criteria for selecting realistic reactor models. Two Oklo reactors, RZ2 and RZ10, were modeled with MCNP. The resulting neutron spectra were used to calculate the change in the ^149Sm effective neutron capture cross section as a function of a possible shift in the energy of the 97.3-meV resonance. We independently deduce ancient ^149Sm effective cross sections, and use these values to set limits on the time-variation of α. Our study resolves a contradictory situation with previous Oklo α-results. Our suggested 2 σ bound on a possible time variation of α over two billion years is stringent: -0.11 <=δαα <=0.24, in units of 10-7, but model dependent in that it assumes only α has varied over time.

  7. The First Cycle of Developing Teaching Materials for Fractions in Grade Five Using Realistic Mathematics Education

    Directory of Open Access Journals (Sweden)

    Hongki Julie

    2013-07-01

    Full Text Available There are three questions that will be answered in this study, namely (1 what are the contexts that can be used to introduce the meaning of multiplication of two fractions and to find the result of multiplying two fractions, (2 how to use these contexts to help students construct the understanding of the meaning of multiplication of two fractions and find the result of multiplying two fractions, and (3 what is the impact of the teaching-learning process that has been designed by researchers on the process of students' knowledge construction. Learning approach which was used in developing teaching materials about fractions is realistic mathematics approach. Lesson plan was created for fifth grade elementary school students. The type of research used is developmental research. According to Gravemeijer and Cobb (in Akker, Gravemeijer, McKeney, and Nieveen, 2006 there are three phases in development research, namely (1 preparation of the trial design, (2 the trial design, and (3 retrospective analysis. This paper presents the results of the first cycle of three cycles that have been planned.Key words: fractions, realistic mathematics education, design research. DOI: http://dx.doi.org/10.22342/jme.4.2.415.172-187

  8. Information theory: Sources, Dirichlet series, and realistic analyses of data structures

    CERN Document Server

    Roux, Mathieu; 10.4204/EPTCS.63.26

    2011-01-01

    Most of the text algorithms build data structures on words, mainly trees, as digital trees (tries) or binary search trees (bst). The mechanism which produces symbols of the words (one symbol at each unit time) is called a source, in information theory contexts. The probabilistic behaviour of the trees built on words emitted by the same source depends on two factors: the algorithmic properties of the tree, together with the information-theoretic properties of the source. Very often, these two factors are considered in a too simplified way: from the algorithmic point of view, the cost of the Bst is only measured in terms of the number of comparisons between words --from the information theoretic point of view, only simple sources (memoryless sources or Markov chains) are studied. We wish to perform here a realistic analysis, and we choose to deal together with a general source and a realistic cost for data structures: we take into account comparisons between symbols, and we consider a general model of source, r...

  9. Field realistic doses of pesticide imidacloprid reduce bumblebee pollen foraging efficiency.

    Science.gov (United States)

    Feltham, Hannah; Park, Kirsty; Goulson, Dave

    2014-04-01

    Bumblebees and other pollinators provide a vital ecosystem service for the agricultural sector. Recent studies however have suggested that exposure to systemic neonicotinoid insecticides in flowering crops has sub-lethal effects on the bumblebee workforce, and hence in reducing queen production. The mechanism behind reduced nest performance, however, remains unclear. Here we use Radio Frequency Identification (RFID) technology to test whether exposure to a low, field realistic dose (0.7 ppb in sugar water and 6 ppb in pollen) of the neonicotinoid imidacloprid, reduces worker foraging efficiency. Whilst the nectar foraging efficiency of bees treated with imidacloprid was not significantly different than that of control bees, treated bees brought back pollen less often than control bees (40 % of trips vs 63 % trips, respectively) and, where pollen was collected, treated bees brought back 31 % less pollen per hour than controls. This study demonstrates that field-realistic doses of these pesticides substantially impacts on foraging ability of bumblebee workers when collecting pollen, and we suggest that this provides a causal mechanism behind reduced queen production in imidacloprid exposed colonies.

  10. Modelling realistic horizontal branch morphologies and their impact on spectroscopic ages of unresolved stellar systems

    CERN Document Server

    Percival, Susan M

    2010-01-01

    The presence of an extended blue horizontal branch (HB) in a stellar population is known to affect the age inferred from spectral fitting to stellar population synthesis models. However, most population synthesis models still rely on theoretical isochrones which do not include realistic modelling of extended HBs. In this work, we create detailed models for a range of old simple stellar populations (SSPs), to create a variety of realistic HB morphologies, from extended red clumps, to extreme blue HBs. We achieve this by utilising stellar tracks from the BaSTI database and implementing a different mass loss prescription for each SSP created, resulting in different HB morphologies. We find that, for each metallicity, there is some HB morphology which maximises Hbeta, making an underlying 14Gyr population look ~5-6Gyr old for the low and intermediate metallicity cases, and as young as 2Gyr for a solar metallicity SSP. We explore whether there are any spectral indices capable of breaking the degeneracy between an ...

  11. Efficient Temperature-Dependent Green's Functions Methods for Realistic Systems: Compact Grids for Orthogonal Polynomial Transforms.

    Science.gov (United States)

    Kananenka, Alexei A; Phillips, Jordan J; Zgid, Dominika

    2016-02-01

    The Matsubara Green's function that is used to describe temperature-dependent behavior is expressed on a numerical grid. While such a grid usually has a couple of hundred points for low-energy model systems, for realistic systems with large basis sets the size of an accurate grid can be tens of thousands of points, constituting a severe computational and memory bottleneck. In this paper, we determine efficient imaginary time grids for the temperature-dependent Matsubara Green's function formalism that can be used for calculations on realistic systems. We show that, because of the use of an orthogonal polynomial transform, we can restrict the imaginary time grid to a few hundred points and reach micro-Hartree accuracy in the electronic energy evaluation. Moreover, we show that only a limited number of orthogonal polynomial expansion coefficients are necessary to preserve accuracy when working with a dual representation of the Green's function or self-energy and transforming between the imaginary time and frequency domain.

  12. A Modern Syllogistic Method in Intuitionistic Fuzzy Logic with Realistic Tautology

    Directory of Open Access Journals (Sweden)

    Ali Muhammad Rushdi

    2015-01-01

    Full Text Available The Modern Syllogistic Method (MSM of propositional logic ferrets out from a set of premises all that can be concluded from it in the most compact form. The MSM combines the premises into a single function equated to 1 and then produces the complete product of this function. Two fuzzy versions of MSM are developed in Ordinary Fuzzy Logic (OFL and in Intuitionistic Fuzzy Logic (IFL with these logics augmented by the concept of Realistic Fuzzy Tautology (RFT which is a variable whose truth exceeds 0.5. The paper formally proves each of the steps needed in the conversion of the ordinary MSM into a fuzzy one. The proofs rely mainly on the successful replacement of logic 1 (or ordinary tautology by an RFT. An improved version of Blake-Tison algorithm for generating the complete product of a logical function is also presented and shown to be applicable to both crisp and fuzzy versions of the MSM. The fuzzy MSM methodology is illustrated by three specific examples, which delineate differences with the crisp MSM, address the question of validity values of consequences, tackle the problem of inconsistency when it arises, and demonstrate the utility of the concept of Realistic Fuzzy Tautology.

  13. Sunset decay of the convective turbulence with Large-Eddy Simulation under realistic conditions

    Science.gov (United States)

    Rizza, U.; Miglietta, M. M.; Degrazia, G. A.; Acevedo, O. C.; Marques Filho, E. P.

    2013-10-01

    Large-Eddy Simulation is performed for a single day from the Cooperative Atmosphere-Surface Exchange Study (CASES-99) field program. This study investigates an observed case of evening transition boundary layer over land. Parameters of the ambient atmosphere in the LES-decay studies conducted so far were typically prescribed in an idealized form. To provide suitable data under the wide range of the PBL weather conditions, the LES should be able to adequately reproduce the PBL turbulence dynamics including-if possible-baroclinicity, radiation, large scale advection and not only be related to a decreasing surface heating. In addition LES-decay studies usually assume that the sensible heat flux decreases instantaneously or with a very short time scale. The main purpose of this investigation is to study the decay of boundary-layer average turbulent kinetic energy at sunset with Large-Eddy Simulation that is forced with realistic environment conditions. This allows investigating the Turbulent Kinetic Energy decay over the realistic time scale that is observed in the atmosphere. During the intermediate and last stage of decay of the boundary-layer average Turbulent Kinetic Energy the exponents of the decay power law t go from 2 to 6, as evidenced by experimental results and recent analytical modeling in the surface layer.

  14. 基于MRI数据的真实头有限元模型构造方法%Finite Element Modeling of Realistic Human Head from MRI Data

    Institute of Scientific and Technical Information of China (English)

    刘君; 武和雷

    2012-01-01

    The FEM geometry modeling of realistic head is a key issue for the research on FEM-based EEG/MEG. In this paper, by the technology of image segmentation and mesh generation, a methodology is developed to construct this kind of model based on original MRI data. Through this method, a five - layers realistic head FEM model is obtained, and with its application in FEM - based EEG, a satisfying result shows the reliability of the model.%构造人体头部的有限元模型是开展基于有限元素法研究脑电现象的先决条件.利用图像分割和网格剖分技术提出了一种完全基于原始MRI数据的真实头有限元模型构造方法.通过该方法构造了一个包含5种组织的真实头有限元模型,将该模型应用到基于有限元素法的脑电计算中,结果显示利用该方法构造出的模型真实可信.

  15. TOXICOLOGICAL EVALUATION OF REALISTIC EMISSIONS OF SOURCE AEROSOLS (TERESA): APPLICATION TO POWER PLANT-DERIVED PM2.5

    Energy Technology Data Exchange (ETDEWEB)

    Annette Rohr

    2006-03-01

    TERESA (Toxicological Evaluation of Realistic Emissions of Source Aerosols) involves exposing laboratory rats to realistic coal-fired power plant and mobile source emissions to help determine the relative toxicity of these PM sources. There are three coal-fired power plants in the TERESA program; this report describes the results of fieldwork conducted at the first plant, located in the Upper Midwest. The project was technically challenging by virtue of its novel design and requirement for the development of new techniques. By examining aged, atmospherically transformed aerosol derived from power plant stack emissions, we were able to evaluate the toxicity of PM derived from coal combustion in a manner that more accurately reflects the exposure of concern than existing methodologies. TERESA also involves assessment of actual plant emissions in a field setting--an important strength since it reduces the question of representativeness of emissions. A sampling system was developed and assembled to draw emissions from the stack; stack sampling conducted according to standard EPA protocol suggested that the sampled emissions are representative of those exiting the stack into the atmosphere. Two mobile laboratories were then outfitted for the study: (1) a chemical laboratory in which the atmospheric aging was conducted and which housed the bulk of the analytical equipment; and (2) a toxicological laboratory, which contained animal caging and the exposure apparatus. Animal exposures were carried out from May-November 2004 to a number of simulated atmospheric scenarios. Toxicological endpoints included (1) pulmonary function and breathing pattern; (2) bronchoalveolar lavage fluid cytological and biochemical analyses; (3) blood cytological analyses; (4) in vivo oxidative stress in heart and lung tissue; and (5) heart and lung histopathology. Results indicated no differences between exposed and control animals in any of the endpoints examined. Exposure concentrations for the

  16. The GLEaMviz computational tool, a publicly available software to explore realistic epidemic spreading scenarios at the global scale

    Directory of Open Access Journals (Sweden)

    Quaggiotto Marco

    2011-02-01

    Full Text Available Abstract Background Computational models play an increasingly important role in the assessment and control of public health crises, as demonstrated during the 2009 H1N1 influenza pandemic. Much research has been done in recent years in the development of sophisticated data-driven models for realistic computer-based simulations of infectious disease spreading. However, only a few computational tools are presently available for assessing scenarios, predicting epidemic evolutions, and managing health emergencies that can benefit a broad audience of users including policy makers and health institutions. Results We present "GLEaMviz", a publicly available software system that simulates the spread of emerging human-to-human infectious diseases across the world. The GLEaMviz tool comprises three components: the client application, the proxy middleware, and the simulation engine. The latter two components constitute the GLEaMviz server. The simulation engine leverages on the Global Epidemic and Mobility (GLEaM framework, a stochastic computational scheme that integrates worldwide high-resolution demographic and mobility data to simulate disease spread on the global scale. The GLEaMviz design aims at maximizing flexibility in defining the disease compartmental model and configuring the simulation scenario; it allows the user to set a variety of parameters including: compartment-specific features, transition values, and environmental effects. The output is a dynamic map and a corresponding set of charts that quantitatively describe the geo-temporal evolution of the disease. The software is designed as a client-server system. The multi-platform client, which can be installed on the user's local machine, is used to set up simulations that will be executed on the server, thus avoiding specific requirements for large computational capabilities on the user side. Conclusions The user-friendly graphical interface of the GLEaMviz tool, along with its high level

  17. Validation of airway resistance models for predicting pressure loss through anatomically realistic conducting airway replicas of adults and children.

    Science.gov (United States)

    Borojeni, Azadeh A T; Noga, Michelle L; Martin, Andrew R; Finlay, Warren H

    2015-07-16

    This work describes in vitro measurement of the total pressure loss at varying flow rate through anatomically realistic conducting airway replicas of 10 children, 4 to 8 years old, and 5 adults. Experimental results were compared with analytical predictions made using published airway resistance models. For the adult replicas, the model proposed by van Ertbruggen et al. (2005. J. Appl. Physiol. 98, 970-980) most accurately predicted central conducting airway resistance for inspiratory flow rates ranging from 15 to 90 L/min. Models proposed by Pedley et al. (1970. J. Respir. Physiol. 9, 371-386) and by Katz et al. (2011. J. Biomech. 44, 1137-1143) also provided reasonable estimates, but with a tendency to over predict measured pressure loss for both models. For child replicas, the Pedley and Katz models both provided good estimation of measured pressure loss at flow rates representative of resting tidal breathing, but under predicted measured values at high inspiratory flow rate (60 L/min). The van Ertbruggen model, developed based on flow simulations performed in an adult airway model, tended to under predict measured pressure loss through the child replicas across the range of flow rates studied (2 to 60 L/min). These results are intended to provide guidance for selection of analytical pressure loss models for use in predicting airway resistance and ventilation distribution in adults and children.

  18. Magnetic breakdown phenomenon in quasi-two-dimensional organic conductors: A quantum model inspired by a realistic band structure

    Science.gov (United States)

    Kim, Ju H.; Han, S. Y.; Brooks, J. S.

    1999-08-01

    We investigate the phenomenon of magnetic breakdown in quasi-two-dimensional organic conductors such as α-(ET)2KHg(SCN)4 and κ-(ET)2Cu(NCS)2 by constructing a tight-binding model based on a realistic band structure which is derived from the crystallographic data. We solve the model numerically to compute the magnetic field dependence of the magnetization and show that the present model accounts naturally for the experimentally observed magnetization oscillation frequencies that are forbidden in the semiclassical picture. The computed values of the fundamental and magnetic breakdown frequencies with no adjustable parameters are close to the experimentally measured values. For completeness, we carry out the computation for both canonical (fixed number of particles) and grand canonical (fixed chemical potential) ensembles, and show that the forbidden frequencies appear in both cases. Hence, the appearance of anomalous frequencies in the de Haas-van Alphen effect has a quantum-mechanical origin and arises from the interplay of electronic states from two partially occupied bands near the Fermi energy as a function of magnetic field. We also compute the temperature dependence of the magnetization and apply ad hoc the Lifshitz-Kosevich analysis to the amplitudes of the Fourier components at moderately high temperatures. This yields effective mass values for α-(ET)2KHg(SCN)4 in good agreement with experimental values.

  19. Monte Carlo simulations of the electric field close to the body in realistic environments for application in personal radiofrequency dosimetry.

    Science.gov (United States)

    Iskra, S; McKenzie, R; Cosic, I

    2011-11-01

    Personal dosemeters can play an important role in epidemiological studies and in radiofrequency safety programmes. In this study, a Monte Carlo approach is used in conjunction with the finite difference time domain method to obtain distributions of the electric field strength close to a human body model in simulated realistic environments. The field is a proxy for the response of an ideal body-worn electric field dosemeter. A set of eight environments were modelled based on the statistics of Rayleigh, Rice and log-normal fading to simulate outdoor and indoor multipath exposures at 450, 900 and 2100 MHz. Results indicate that a dosemeter mounted randomly within 10-50 mm of the adult or child body model (torso region) will on average underestimate the spatially averaged value of the incident electric field strength by a factor of 0.52 to 0.74 over the frequencies of 450, 900 and 2100 MHz. The uncertainty in results, assessed at the 95 % confidence level (between the 2.5th and 97.5th percentiles) was largest at 2100 MHz and smallest at 450 MHz.

  20. Realistic Rendering of the Evolution of Universe%宇宙演化的真实感绘制

    Institute of Scientific and Technical Information of China (English)

    金哲凡

    2012-01-01

    Millennium-2是目前规模最大的宇宙演化数值模拟项目.用光滑粒子动力学描述粒子对空间的影响,并用辐射传输方程构建光照模型,可绘制宇宙演化的真实感图像.由算法的能量合成保持线性形式的特点得到一种粒子并行的并行办法.将粒子足迹沿扫描线细分,可缓解程序分支扩散和粒度不均匀的问题,使该办法可以在CUDA平台上实现.测试数据证明本文的方法是有效的.%Millennium—2 is so far the largest simulation for the evolution of universe. Realistic image can be generated with smooth particle hydrodynamics describing the influence of particles to space and radiative transfer equation as lighting model. From the linear form by which particles' energy accumulated a particle—based parallel processing method is implemented. To implement parallel rendering on CUDA platform, footprints of particles are split by scan lines to alleviate program branch spreading and imbalance of paralleling granularity. Test results show the methods presented are effective.