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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. Rheology-based facial animation realistic face model

    Institute of Scientific and Technical Information of China (English)

    ZENG Dan; PEI Li

    2009-01-01

    This paper presents a rheology-based approach to animate realistic face model. The dynamic and biorheological characteristics of the force member (muscles) and stressed member (face) are considered. The stressed face can be modeled as viscoelastic bodies with the Hooke bodies and Newton bodies connected in a composite series-parallel manner. Then, the stress-strain relationship is derived, and the constitutive equations established. Using these constitutive equations, the face model can be animated with the force generated by muscles. Experimental results show that this method can realistically simulate the mechanical properties and motion characteristics of human face, and performance of this method is satisfactory.

  4. The use and limitation of realistic evaluation as a tool for evidence-based practice: a critical realist perspective.

    Science.gov (United States)

    Porter, Sam; O'Halloran, Peter

    2012-03-01

    The use and limitation of realistic evaluation as a tool for evidence-based practice: a critical realist perspective In this paper, we assess realistic evaluation's articulation with evidence-based practice (EBP) from the perspective of critical realism. We argue that the adoption by realistic evaluation of a realist causal ontology means that it is better placed to explain complex healthcare interventions than the traditional method used by EBP, the randomized controlled trial (RCT). However, we do not conclude from this that the use of RCTs is without merit, arguing that it is possible to use both methods in combination under the rubric of realist theory. More negatively, we contend that the rejection of critical theory and utopianism by realistic evaluation in favour of the pragmatism of piecemeal social engineering means that it is vulnerable to accusations that it promotes technocratic interpretations of human problems. We conclude that, insofar as realistic evaluation adheres to the ontology of critical realism, it provides a sound contribution to EBP, but insofar as it rejects the critical turn of Bhaskar's realism, it replicates the technocratic tendencies inherent in EBP. PMID:22212367

  5. Realistic terrain visualization based on 3D virtual world technology

    Science.gov (United States)

    Huang, Fengru; Lin, Hui; Chen, Bin; Xiao, Cai

    2010-11-01

    The rapid advances in information technologies, e.g., network, graphics processing, and virtual world, have provided challenges and opportunities for new capabilities in information systems, Internet applications, and virtual geographic environments, especially geographic visualization and collaboration. In order to achieve meaningful geographic capabilities, we need to explore and understand how these technologies can be used to construct virtual geographic environments to help to engage geographic research. The generation of three-dimensional (3D) terrain plays an important part in geographical visualization, computer simulation, and virtual geographic environment applications. The paper introduces concepts and technologies of virtual worlds and virtual geographic environments, explores integration of realistic terrain and other geographic objects and phenomena of natural geographic environment based on SL/OpenSim virtual world technologies. Realistic 3D terrain visualization is a foundation of construction of a mirror world or a sand box model of the earth landscape and geographic environment. The capabilities of interaction and collaboration on geographic information are discussed as well. Further virtual geographic applications can be developed based on the foundation work of realistic terrain visualization in virtual environments.

  6. Ultra-realistic 3-D imaging based on colour holography

    Science.gov (United States)

    Bjelkhagen, H. I.

    2013-02-01

    A review of recent progress in colour holography is provided with new applications. Colour holography recording techniques in silver-halide emulsions are discussed. Both analogue, mainly Denisyuk colour holograms, and digitally-printed colour holograms are described and their recent improvements. An alternative to silver-halide materials are the panchromatic photopolymer materials such as the DuPont and Bayer photopolymers which are covered. The light sources used to illuminate the recorded holograms are very important to obtain ultra-realistic 3-D images. In particular the new light sources based on RGB LEDs are described. They show improved image quality over today's commonly used halogen lights. Recent work in colour holography by holographers and companies in different countries around the world are included. To record and display ultra-realistic 3-D images with perfect colour rendering are highly dependent on the correct recording technique using the optimal recording laser wavelengths, the availability of improved panchromatic recording materials and combined with new display light sources.

  7. 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...

  8. 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 and...

  9. Discovering multiple realistic TFBS motifs based on a generalized model

    Directory of Open Access Journals (Sweden)

    Leung Kwong-Sak

    2009-10-01

    Full Text Available Abstract Background Identification of transcription factor binding sites (TFBSs is a central problem in Bioinformatics on gene regulation. de novo motif discovery serves as a promising way to predict and better understand TFBSs for biological verifications. Real TFBSs of a motif may vary in their widths and their conservation degrees within a certain range. Deciding a single motif width by existing models may be biased and misleading. Additionally, multiple, possibly overlapping, candidate motifs are desired and necessary for biological verification in practice. However, current techniques either prohibit overlapping TFBSs or lack explicit control of different motifs. Results We propose a new generalized model to tackle the motif widths by considering and evaluating a width range of interest simultaneously, which should better address the width uncertainty. Moreover, a meta-convergence framework for genetic algorithms (GAs, is proposed to provide multiple overlapping optimal motifs simultaneously in an effective and flexible way. Users can easily specify the difference amongst expected motif kinds via similarity test. Incorporating Genetic Algorithm with Local Filtering (GALF for searching, the new GALF-G (G for generalized algorithm is proposed based on the generalized model and meta-convergence framework. Conclusion GALF-G was tested extensively on over 970 synthetic, real and benchmark datasets, and is usually better than the state-of-the-art methods. The range model shows an increase in sensitivity compared with the single-width ones, while providing competitive precisions on the E. coli benchmark. Effectiveness can be maintained even using a very small population, exhibiting very competitive efficiency. In discovering multiple overlapping motifs in a real liver-specific dataset, GALF-G outperforms MEME by up to 73% in overall F-scores. GALF-G also helps to discover an additional motif which has probably not been annotated in the dataset

  10. 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.

  11. Realistic Approach towards Quantitative Analysis and Simulation of EEHC-Based Routing for Wireless Sensor Networks

    CERN Document Server

    Sharma, Manju

    2010-01-01

    This paper presents the realistic approach towards the quantitative analysis and simulation of Energy Efficient Hierarchical Cluster (EEHC)-based routing for wireless sensor networks. Here the efforts have been done to combine analytical hardware model with the modified EEHC-based routing model. The dependence of various performance metrics like: optimum number of clusters, Energy Consumption, and Energy consumed per round etc. based on analytical hardware sensor model and EEHC model has been presented.

  12. 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.

  13. 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.

  14. Interactive Web-based Floodplain Simulation System for Realistic Experiments of Flooding and Flood Damage

    Science.gov (United States)

    Demir, I.

    2013-12-01

    Recent developments in web technologies make it easy to manage and visualize large data sets with general public. Novel visualization techniques and dynamic user interfaces allow users to create realistic environments, and interact with data to gain insight from simulations and environmental observations. The floodplain simulation system is a web-based 3D interactive flood simulation environment to create real world flooding scenarios. The simulation systems provides a visually striking platform with realistic terrain information, and water simulation. Students can create and modify predefined scenarios, control environmental parameters, and evaluate flood mitigation techniques. The web-based simulation system provides an environment to children and adults learn about the flooding, flood damage, and effects of development and human activity in the floodplain. The system provides various scenarios customized to fit the age and education level of the users. This presentation provides an overview of the web-based flood simulation system, and demonstrates the capabilities of the system for various flooding and land use scenarios.

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

    International Nuclear Information System (INIS)

    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

  16. 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

  17. 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...

  18. Population of 100 realistic, patient-based computerized breast phantoms for multi-modality imaging research

    Science.gov (United States)

    Segars, W. Paul; Veress, Alexander I.; Wells, Jered R.; Sturgeon, Gregory M.; Kiarashi, Nooshin; Lo, Joseph Y.; Samei, Ehsan; Dobbins, James T.

    2014-03-01

    Breast imaging is an important area of research with many new techniques being investigated to further reduce the morbidity and mortality of breast cancer through early detection. Computerized phantoms can provide an essential tool to quantitatively compare new imaging systems and techniques. Current phantoms, however, lack sufficient realism in depicting the complex 3D anatomy of the breast. In this work, we created one-hundred realistic and detailed 3D computational breast phantoms based on high-resolution CT datasets from normal patients. We also developed a finiteelement application to simulate different compression states of the breast, making the phantoms applicable to multimodality imaging research. The breast phantoms and tools developed in this work were packaged into user-friendly software applications to distribute for breast imaging research.

  19. A realistic projection simulator for laboratory based X-ray micro-CT

    Energy Technology Data Exchange (ETDEWEB)

    Dhaene, Jelle, E-mail: jelle.dhaene@ugent.be; Pauwels, Elin, E-mail: elin.pauwels@ugent.be; De Schryver, Thomas; De Muynck, Amelie; Dierick, Manuel; Van Hoorebeke, Luc

    2015-01-01

    In X-ray computed tomography (CT) each voxel of the reconstructed image contains a calculated grey value which represents the linear attenuation coefficient for the materials in that voxel. Conventional laboratory based CT scanners use polychromatic X-ray sources and integrating detectors with an energy dependent efficiency. Consequently the reconstructed attenuation coefficients will depend on the spectrum of the source and the spectral sensitivity of the detector. Beam hardening will alter the spectrum significantly as the beam propagates through the sample. Therefore, sample composition and shape will affect the reconstructed attenuation coefficients as well. A polychromatic projection simulator has been developed at the “Centre for X-ray Tomography” of the Ghent University (UGCT) which takes into account the aforementioned variables, allowing for complete and realistic simulations of CT scans for a wide range of geometrical setups. Monte Carlo simulations of the X-ray tubes and detectors were performed to model their spectral behaviour. In this paper, the implementation and features of the program are discussed. Simulated and real CT scans are compared to demonstrate the quantitative correctness of the simulations. Experiments performed at two different UGCT scanners yield a maximum deviation of 3.9% and 6.5% respectively, between the measured and simulated reconstructed attenuation coefficients.

  20. Students' Critical Mathematical Thinking Skills and Character: Experiments for Junior High School Students through Realistic Mathematics Education Culture-Based

    Science.gov (United States)

    Palinussa, Anderson L.

    2013-01-01

    This paper presents the findings of a quasi-experimental with pre-test-post-test design and control group that aims to assess students' critical mathematical thinking skills and character through realistic mathematics education (RME) culture-based. Subjects of this study were 106 junior high school students from two low and medium schools level in…

  1. Internet-based medical education: a realist review of what works, for whom and in what circumstances

    OpenAIRE

    Greenhalgh Trisha; Wong Geoff; Pawson Ray

    2010-01-01

    Abstract Background Educational courses for doctors and medical students are increasingly offered via the Internet. Despite much research, course developers remain unsure about what (if anything) to offer online and how. Prospective learners lack evidence-based guidance on how to choose between the options on offer. We aimed to produce theory driven criteria to guide the development and evaluation of Internet-based medical courses. Methods Realist review - a qualitative systematic review meth...

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

    International Nuclear Information System (INIS)

    The influence of temporal daily exposure to global system for mobile communications (GSM) and universal mobile telecommunications systems and high speed down-link 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. (authors)

  3. 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.

  4. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M., E-mail: rthomson@physics.carleton.ca [Carleton Laboratory for Radiotherapy Physics, Department of Physics, Carleton University, Ottawa K1S 5B6 (Canada)

    2014-02-15

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with{sup 125}I, {sup 103}Pd, or {sup 131}Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model

  5. Model-based dose calculations for COMS eye plaque brachytherapy using an anatomically realistic eye phantom

    International Nuclear Information System (INIS)

    Purpose : To investigate the effects of the composition and geometry of ocular media and tissues surrounding the eye on dose distributions for COMS eye plaque brachytherapy with125I, 103Pd, or 131Cs seeds, and to investigate doses to ocular structures. Methods : An anatomically and compositionally realistic voxelized eye model with a medial tumor is developed based on a literature review. Mass energy absorption and attenuation coefficients for ocular media are calculated. Radiation transport and dose deposition are simulated using the EGSnrc Monte Carlo user-code BrachyDose for a fully loaded COMS eye plaque within a water phantom and our full eye model for the three radionuclides. A TG-43 simulation with the same seed configuration in a water phantom neglecting the plaque and interseed effects is also performed. The impact on dose distributions of varying tumor position, as well as tumor and surrounding tissue media is investigated. Each simulation and radionuclide is compared using isodose contours, dose volume histograms for the lens and tumor, maximum, minimum, and average doses to structures of interest, and doses to voxels of interest within the eye. Results : Mass energy absorption and attenuation coefficients of the ocular media differ from those of water by as much as 12% within the 20–30 keV photon energy range. For all radionuclides studied, average doses to the tumor and lens regions in the full eye model differ from those for the plaque in water by 8%–10% and 13%–14%, respectively; the average doses to the tumor and lens regions differ between the full eye model and the TG-43 simulation by 2%–17% and 29%–34%, respectively. Replacing the surrounding tissues in the eye model with water increases the maximum and average doses to the lens by 2% and 3%, respectively. Substituting the tumor medium in the eye model for water, soft tissue, or an alternate melanoma composition affects tumor dose compared to the default eye model simulation by up to 16

  6. 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

  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 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.

  9. Modeling and Design of Realistic Si3N4-BASED Integrated Optical Programmable Power Splitter

    Science.gov (United States)

    Uranus, H. P.; Hoekstra, H. J. W. M.; Stoffer, R.

    Controllable splitting of optical power with a large splitting ratio range is often required in an integrated optical chip, e.g. for the readout of phase-shift in a slow-light sensor. In this work, we report the modeling and design of an integrated optical programmable power splitter consisting of a Y-junction with a programmable phase-shifter cascaded to a directional coupler. We used a vectorial mode solver, and a combination of a transfer matrix method with a 3D vectorial coupled-mode theory (CMT) to compute the power transfer ratio of a realistic device structure made of Si3N4, TEOS, and SiO2 grown on a Si substrate. In the simulations, waveguide attenuation values derived from the measured attenuation of a prefabricated test wafer, have been taken into account. Vectorial modal fields of individual waveguides, as computed by a mode solver, were used as the basis for the CMT computation. In the simulation, an operational wavelength around 632.8 nm was assumed. Our simulations reveal that maximum power splitting ratio can be achieved when the directional coupler is operated as a 3-dB coupler with the phase-shifter set to produce a 90° phase-shift. The required coupler length for such desired operating condition is highly-dependent on the gap size. On the other hand, the inclusion of the waveguide loss and the non-parallel section of the directional coupler into the model only slightly affect the results.

  10. 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.

  11. Students’ Critical Mathematical Thinking Skills and Character: Experiments for Junior High School Students through Realistic Mathematics Education Culture-Based

    Directory of Open Access Journals (Sweden)

    Anderson L. Palinussa

    2013-01-01

    Full Text Available This paper presents the findings of a quasi-experimental with pre-testpost-test design and control group that aims to assess students’ critical mathematical thinking skills and character through realisticmathematics education (RME culture-based. Subjects of this studywere 106 junior high school students from two low and medium schools level in Ambon. The instruments of the study are: students’ early math skills test, critical thinking skills mathematical test and perception scale of students’character. Data was analyzed by using t test and Anova. The study found that: 1 Achievements and enhancement of students’ critical mathematical thinking skills who were treated with by realistic mathematics education is better then students’ skills were treated by conventional mathematics education. The differences are considered to: a overall students, b the level of early math skills, and c schools’ level; 2 Quality of students’ characterwho were treated by realistic mathematics education is better thenstudents’ character who were treated by conventional mathematicseducation The differences are considered to: a overall students, b the level of early math skills, and c schools’ level

  12. Assessment of realistic nowcasting lead-times based on predictability analysis of Mediterranean Heavy Precipitation Events

    Science.gov (United States)

    Bech, Joan; Berenguer, Marc

    2014-05-01

    ' precipitation forecasts showed some skill (improvement over persistence) for lead times up to 60' for moderate intensities (up to 1 mm in 30') and up to 2.5h for lower rates (above 0.1 mm). However an important event-to-event variability has been found as illustrated by the fact that hit rates of rain-no-rain forecasts achieved the 60% value at 90' in the 7 September 2005 and only 40' in the 2 November 2008 case. The discussion of these results provides useful information on the potential application of nowcasting systems and realistic values to be contrasted with specific end-user requirements. This work has been done in the framework of the Hymex research programme and has been partly funded by the ProFEWS project (CGL2010-15892). References Bech J, N Pineda, T Rigo, M Aran, J Amaro, M Gayà, J Arús, J Montanyà, O van der Velde, 2011: A Mediterranean nocturnal heavy rainfall and tornadic event. Part I: Overview, damage survey and radar analysis. Atmospheric Research 100:621-637 http://dx.doi.org/10.1016/j.atmosres.2010.12.024 Bech J, R Pascual, T Rigo, N Pineda, JM López, J Arús, and M Gayà, 2007: An observational study of the 7 September 2005 Barcelona tornado outbreak. Natural Hazards and Earth System Science 7:129-139 http://dx.doi.org/10.5194/nhess-7-129-2007 Berenguer M, C Corral, R Sa'nchez-Diezma, D Sempere-Torres, 2005: Hydrological validation of a radarbased nowcasting technique. Journal of Hydrometeorology 6: 532-549 http://dx.doi.org/10.1175/JHM433.1 Berenguer M, D Sempere, G Pegram, 2011: SBMcast - An ensemble nowcasting technique to assess the uncertainty in rainfall forecasts by Lagrangian extrapolation. Journal of Hydrology 404: 226-240 http://dx.doi.org/10.1016/j.jhydrol.2011.04.033 Pierce C, A Seed, S Ballard, D Simonin, Z Li, 2012: Nowcasting. In Doppler Radar Observations (J Bech, JL Chau, ed.) Ch. 13, 98-142. InTech, Rijeka, Croatia http://dx.doi.org/10.5772/39054

  13. 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.

  14. Role of institutional entrepreneurship in building adaptive capacity in community-based healthcare organisations: realist review protocol

    Science.gov (United States)

    Iyengar, Sweatha; Katz, Aaron; Durham, Jo

    2016-01-01

    Introduction Over the past 3 decades, there has been a substantial shift to the marketisation of government-funded health services. For organisations traditionally buffered from the competitive pressures of for-profit enterprises, such as community-based organisations, this means developing the capacity to adapt to competitive tendering processes, shifting client expectations, and increasing demands for greater accountability. Drawing on ideas of institutional entrepreneurship, we believe that attempts to build adaptive capacity require the transformation of existing institutional arrangements. Key in this may be identifying and fostering institutional entrepreneurs—actors who take the lead in being the impetus for, and giving direction to, structural change. This study focuses on the strategies used by institutional entrepreneurs to build adaptive capacity in the community-based healthcare sector. Methods and analysis The research will use an adapted rapid realist review. The review will find underlying theories that explain the circumstances surrounding the implementation of capacity-building strategies that shape organisational response and generate outcomes by activating causal mechanisms. An early scoping of the literature, and consultations with key stakeholders, will be undertaken to identify an initial programme theory. We will search for relevant journal articles and grey literature. Data will be extracted based on contextual factors, mechanisms and outcomes, and their configurations. The analysis will seek patterns and regularities in these configurations and will focus on confirming, refuting or refining our programme theory. Ethics and dissemination The study does not involve primary research and, therefore, does not require formal ethical approval. However, ethical standards of utility, usefulness, feasibility, propriety, accuracy and accountability will be followed. The results will be written up according to the Realist and Meta-Review Evidence

  15. 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...

  16. Research protocol: a realist synthesis of contestability in community-based mental health markets

    OpenAIRE

    Durham, Jo; Bains, Amara

    2015-01-01

    Background In most developed nations, there has been a shift from public services to a marketisation of public goods and services - representing a significant reform process aiming to transform the way in which community-based human services, such as health, are delivered and consumed. For services, this means developing the capacity to adapt and innovate in response to changing circumstances to achieve quality. The availability of rigorous research to demonstrate whether a market approach an...

  17. 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...

  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. 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

  20. SEM-EBSD based Realistic Modeling and Crystallographic Homogenization FE Analyses of LDH Formability Tests

    Science.gov (United States)

    Kuramae, Hiroyuki; Ngoc Tam, Nguyen; Nakamura, Yasunori; Sakamoto, Hidetoshi; Morimoto, Hideo; Nakamachi, Eiji

    2007-05-01

    Homogenization algorithm is introduced to the elastic/crystalline viscoplastic finite element (FE) procedure to develop multi-scale analysis code to predict the formability of sheet metal in macro scale, and simultaneously the crystal texture and hardening evolutions in micro scale. The isotropic and kinematical hardening lows are employed in the crystalline plasticity constitutive equation. For the multi-scale structure, two scales are considered. One is a microscopic polycrystal structure and the other a macroscopic elastic plastic continuum. We measure crystal morphologies by using the scanning electron microscope (SEM) with electron back scattered diffraction (EBSD), and define a three dimensional representative volume element (RVE) of micro ploycrystal structure, which satisfy the periodicity condition of crystal orientation distribution. Since nonlinear multi-scale FE analysis requires large computation time, development of parallel computing technique is needed. To realize the parallel analysis on PC cluster system, the dynamic explicit FE formulations are employed. Applying the domain partitioning technique to FE mesh of macro continuum, homogenized stresses based on micro crystal structures are computed in parallel without solving simultaneous linear equation. The parallel FEM code is applied to simulate the limit dome height (LDH) test problem and hemispherical cup deep drawing problem of aluminum alloy AL6022, mild steel DQSK, high strength steel HSLA, and dual phase steel DP600 sheet metals. The localized distribution of thickness strain and the texture evolution are obtained.

  1. 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.

  2. Creating a Realistic Weather Environment for Motion-Based Piloted Flight Simulation

    Science.gov (United States)

    Daniels, Taumi S.; Schaffner, Philip R.; Evans, Emory T.; Neece, Robert T.; Young, Steve D.

    2012-01-01

    A flight simulation environment is being enhanced to facilitate experiments that evaluate research prototypes of advanced onboard weather radar, hazard/integrity monitoring (HIM), and integrated alerting and notification (IAN) concepts in adverse weather conditions. The simulation environment uses weather data based on real weather events to support operational scenarios in a terminal area. A simulated atmospheric environment was realized by using numerical weather data sets. These were produced from the High-Resolution Rapid Refresh (HRRR) model hosted and run by the National Oceanic and Atmospheric Administration (NOAA). To align with the planned flight simulation experiment requirements, several HRRR data sets were acquired courtesy of NOAA. These data sets coincided with severe weather events at the Memphis International Airport (MEM) in Memphis, TN. In addition, representative flight tracks for approaches and departures at MEM were generated and used to develop and test simulations of (1) what onboard sensors such as the weather radar would observe; (2) what datalinks of weather information would provide; and (3) what atmospheric conditions the aircraft would experience (e.g. turbulence, winds, and icing). The simulation includes a weather radar display that provides weather and turbulence modes, derived from the modeled weather along the flight track. The radar capabilities and the pilots controls simulate current-generation commercial weather radar systems. Appropriate data-linked weather advisories (e.g., SIGMET) were derived from the HRRR weather models and provided to the pilot consistent with NextGen concepts of use for Aeronautical Information Service (AIS) and Meteorological (MET) data link products. The net result of this simulation development was the creation of an environment that supports investigations of new flight deck information systems, methods for incorporation of better weather information, and pilot interface and operational improvements

  3. 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.

  4. 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.

  5. Internet-based medical education: a realist review of what works, for whom and in what circumstances

    Directory of Open Access Journals (Sweden)

    Greenhalgh Trisha

    2010-02-01

    Full Text Available Abstract Background Educational courses for doctors and medical students are increasingly offered via the Internet. Despite much research, course developers remain unsure about what (if anything to offer online and how. Prospective learners lack evidence-based guidance on how to choose between the options on offer. We aimed to produce theory driven criteria to guide the development and evaluation of Internet-based medical courses. Methods Realist review - a qualitative systematic review method whose goal is to identify and explain the interaction between context, mechanism and outcome. We searched 15 electronic databases and references of included articles, seeking to identify theoretical models of how the Internet might support learning from empirical studies which (a used the Internet to support learning, (b involved doctors or medical students; and (c reported a formal evaluation. All study designs and outcomes were considered. Using immersion and interpretation, we tested theories by considering how well they explained the different outcomes achieved in different educational contexts. Results 249 papers met our inclusion criteria. We identified two main theories of the course-in-context that explained variation in learners' satisfaction and outcomes: Davis's Technology Acceptance Model and Laurillard's model of interactive dialogue. Learners were more likely to accept a course if it offered a perceived advantage over available non-Internet alternatives, was easy to use technically, and compatible with their values and norms. 'Interactivity' led to effective learning only if learners were able to enter into a dialogue - with a tutor, fellow students or virtual tutorials - and gain formative feedback. Conclusions Different modes of course delivery suit different learners in different contexts. When designing or choosing an Internet-based course, attention must be given to the fit between its technical attributes and learners' needs and

  6. 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.

  7. 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

  8. 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

  9. 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...

  10. Human factor integration into the development of a realistic tree-rendering system based on lidar remote sensing

    Science.gov (United States)

    Fujisaki, Ikuko; Evans, David L.; Moorhead, Robert J.; Mohammadi-Aragh, Mahnas Jean; Irby, Derek W.; Roberts, Scott D.

    2004-05-01

    This paper introduces application of the Cave Automatic Virtual Environment (CAVE) to forest visualization and user studies which were designed to gain insight into human factors for system development. This interdisciplinary research project was undertaken by the Visualization, Analysis, and Imaging Laboratory and the Department of Forestry at Mississippi State University (MSU). The purpose was to create a forest management tool for remote examination of stands in a stereoscopic environment which allows users to observe and interact with realistic virtual stands. The datasets used in this study include measurements such as total height, Diameter at the Breast Height (DBH), and crown radii. The datasets were directly and indirectly generated from Light Detection and Ranging (LiDAR) data. The datasets from immature (eight-years-old) high density and mature (40-years-old) low density loblolly pine (Pinus taeda) stands were used to generate three types of tree models. These three models represent trees in different graphic-complexities and thus interactivity. In general, higher fidelity is preferred in visualization. However, there is a trade-off between graphic details and interaction speed. To determine an optimal model, a user study was designed to examine the influence photo-reality and interactivity have on the viewer's perception. Human subjects recruited from MSU's Department of Forestry will explore virtual stands rendered with one of the tree models in the CAVE and estimate forest parameters.

  11. Rapid hologram generation utilizing layer-based approach and graphic rendering for realistic three-dimensional image reconstruction by angular tiling

    Science.gov (United States)

    Chen, Jhen-Si; Chu, Daping; Smithwick, Quinn

    2014-03-01

    An approach of rapid hologram generation for the realistic three-dimensional (3-D) image reconstruction based on the angular tiling concept is proposed, using a new graphic rendering approach integrated with a previously developed layer-based method for hologram calculation. A 3-D object is simplified as layered cross-sectional images perpendicular to a chosen viewing direction, and our graphics rendering approach allows the incorporation of clear depth cues, occlusion, and shading in the generated holograms for angular tiling. The combination of these techniques together with parallel computing reduces the computation time of a single-view hologram for a 3-D image of extended graphics array resolution to 176 ms using a single consumer graphics processing unit card.

  12. 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.

  13. Expanding the Parameters for Excellence in Patient Assignments: Is Leveraging an Evidence-Data-Based Acuity Methodology Realistic?

    Science.gov (United States)

    Gray, Joel; Kerfoot, Karlene

    2016-01-01

    Finding the balance of equitable assignments continues to be a challenge for health care organizations seeking to leverage evidence-based leadership practices. Ratios and subjective acuity strategies for nurse-patient staffing continue to be the dominant approach in health care organizations. In addition to ratio-based assignments and acuity-based assignment models driven by financial targets, more emphasis on using evidence-based leadership strategies to manage and create science for effective staffing is needed. In particular, nurse leaders are challenged to increase the sophistication of management of patient turnover (admissions, discharges, and transfers) and integrate tools from Lean methodologies and quality management strategies to determine the effectiveness of nurse-patient staffing. PMID:26636229

  14. Modelling Hen Harrier Dynamics to Inform Human-Wildlife Conflict Resolution: A Spatially-Realistic, Individual-Based Approach

    OpenAIRE

    Heinonen, Johannes P. M.; Palmer, Stephen C.F.; Redpath, Steve M.; Travis, Justin M. J.

    2014-01-01

    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 ...

  15. Students’ Critical Mathematical Thinking Skills and Character: Experiments for Junior High School Students through Realistic Mathematics Education Culture-Based

    OpenAIRE

    Anderson L. Palinussa

    2013-01-01

    This paper presents the findings of a quasi-experimental with pre-testpost-test design and control group that aims to assess students’ critical mathematical thinking skills and character through realisticmathematics education (RME) culture-based. Subjects of this studywere 106 junior high school students from two low and medium schools level in Ambon. The instruments of the study are: students’ early math skills test, critical thinking skills mathematical test and perception scale of students...

  16. Realistic outcomes: lessons from community-based research and demonstration programs for the prevention of cardiovascular diseases.

    Science.gov (United States)

    Mittelmark, M B; Hunt, M K; Heath, G W; Schmid, T L

    1993-01-01

    Public health departments nation-wide are implementing community-based cardiovascular disease (CVD) prevention programs. Many such programs are turning for guidance to three research and demonstration projects: the Stanford Five City Project, the Pawtucket Heart Health Program, and the Minnesota Heart Health Program. This article summarizes some of the lessons learned in these projects and recommends strategies for the new generation of CVD prevention programs. The core of a successful program is the community organization process. This involves identification and activation of key community leaders, stimulation of citizens and organizations to volunteer time and offer resources to CVD prevention, and the promotion of prevention as a community theme. A wide range of intervention settings are available for health promotion. As is true for the workplace, places of worship are receptive to health promotion programs and have access to large numbers of people. Mass media are effective when used in conjunction with complementary messages delivered through other channels, such as school programs, adult education programs, and self-help programs. Community health professionals play a vital role in providing program endorsement and stimulating the participation of other community leaders. School-based programs promote long-term behavior change and reach beyond the school to actively involve parents. Innovative health promotion contests have widespread appeal and promote participation in other community interventions. In the area of evaluation, health program participation rates are appropriate primary outcome measures in most community-oriented prevention programs. Other program evaluation priorities include community analysis and formative evaluation, providing data to fine-tune interventions and define the needs and preferences of the community. It is premature to comment conclusively on the effectiveness of community-based CVD prevention programs in reducing population

  17. 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.

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

    Science.gov (United States)

    Heinonen, Johannes P M; Palmer, Stephen C F; Redpath, Steve M; Travis, Justin M J

    2014-01-01

    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. PMID:25405860

  19. 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

  20. 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...

  1. A realistic fabrication and design concept for quantum gates based on single emitters integrated in plasmonic-dielectric waveguide structures.

    Science.gov (United States)

    Kewes, Günter; Schoengen, Max; Neitzke, Oliver; Lombardi, Pietro; Schönfeld, Rolf-Simon; Mazzamuto, Giacomo; Schell, Andreas W; Probst, Jürgen; Wolters, Janik; Löchel, Bernd; Toninelli, Costanza; Benson, Oliver

    2016-01-01

    Tremendous enhancement of light-matter interaction in plasmonic-dielectric hybrid devices allows for non-linearities at the level of single emitters and few photons, such as single photon transistors. However, constructing integrated components for such devices is technologically extremely challenging. We tackle this task by lithographically fabricating an on-chip plasmonic waveguide-structure connected to far-field in- and out-coupling ports via low-loss dielectric waveguides. We precisely describe our lithographic approach and characterize the fabricated integrated chip. We find excellent agreement with rigorous numerical simulations. Based on these findings we perform a numerical optimization and calculate concrete numbers for a plasmonic single-photon transistor. PMID:27364604

  2. Towards an agential realist thinking of learning

    DEFF Research Database (Denmark)

    Plauborg, Helle

    2014-01-01

    This paper explores what can be understood by learning based on agential realist thinking. An agential realist thinking about learning is sensitive to the complexity that characterizes learning as a phenomenon. Thus, learning, from an agential realist perspective, is a dynamic and emergent....... This paper argues that intra-activity and 'leaps' are characteristics of learning. Thereby, transfer will be addressed and explained. Re-configurations are pivotal for this thinking about learning, and the concept of re-configurations breaks the tendency to understand learning as either more of the same...

  3. 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.

  4. Realistic Composite Higgs Models

    CERN Document Server

    Anastasiou, Charalampos; Santiago, Jose

    2009-01-01

    We study the role of fermionic resonances in realistic composite Higgs models. We consider the low energy effective description of a model in which the Higgs arises as the pseudo-Goldstone boson of an SO(5)/SO(4) global symmetry breaking pattern. Assuming that only fermionic resonances are present below the cut-off of our effective theory, we perform a detailed analysis of the electroweak constraints on such a model. This includes the exact one-loop calculation of the T parameter and the anomalous Zbb coupling for arbitrary new fermions and couplings. Other relevant observables, like b to s gamma and Delta B=2 processes have been also examined. We find that, while minimal models are difficult to make compatible with electroweak precision tests, models with several fermionic resonances, such as the ones that appear in the spectrum of viable composite Higgs models from warped extra dimensions, are fully realistic in a large region of parameter space. These fermionic resonances could be the first observable sign...

  5. Ce K edge XAS of ceria-based redox materials under realistic conditions for the two-step solar thermochemical dissociation of water and/or CO2.

    Science.gov (United States)

    Rothensteiner, Matthäus; Sala, Simone; Bonk, Alexander; Vogt, Ulrich; Emerich, Hermann; van Bokhoven, Jeroen A

    2015-10-28

    X-ray absorption spectroscopy was used to characterise ceria-based materials under realistic conditions present in a reactor for solar thermochemical two-step water and carbon dioxide splitting. A setup suitable for in situ measurements in transmission mode at the cerium K edge from room temperature up to 1773 K is presented. Time-resolved X-ray absorption near-edge structure (XANES) data, collected for a 10 mol% hafnium-doped ceria sample (Ce0.9Hf0.1O2-δ) during reduction at 1773 K in a flow of inert gas and during re-oxidation by CO2 at 1073 K, enables the quantitative determination of the non-stoichiometry δ of the fluorite-type structure. XANES analysis suggests the formation of the hexagonal Ce2O3 phase upon reduction in 2% hydrogen/helium at 1773 K. We discuss the experimental limitations and possibilities of high-temperature in situ XAS at edges of lower energy as well as the importance of the technique for understanding and improving the properties of ceria-based oxygen storage materials for thermochemical solar energy conversion. PMID:26412705

  6. Benchmark test cases for evaluation of computer-based methods for detection of setup errors: realistic digitally reconstructed electronic portal images with known setup errors

    International Nuclear Information System (INIS)

    Purpose: The purpose of this investigation was to develop methods and software for computing realistic digitally reconstructed electronic portal images with known setup errors for use as benchmark test cases for evaluation and intercomparison of computer-based methods for image matching and detecting setup errors in electronic portal images. Methods and Materials: An existing software tool for computing digitally reconstructed radiographs was modified to compute simulated megavoltage images. An interface was added to allow the user to specify which setup parameter(s) will contain computer-induced random and systematic errors in a reference beam created during virtual simulation. Other software features include options for adding random and structured noise, Gaussian blurring to simulate geometric unsharpness, histogram matching with a 'typical' electronic portal image, specifying individual preferences for the appearance of the 'gold standard' image, and specifying the number of images generated. The visible male computed tomography data set from the National Library of Medicine was used as the planning image. Results: Digitally reconstructed electronic portal images with known setup errors have been generated and used to evaluate our methods for automatic image matching and error detection. Any number of different sets of test cases can be generated to investigate setup errors involving selected setup parameters and anatomic volumes. This approach has proved to be invaluable for determination of error detection sensitivity under ideal (rigid body) conditions and for guiding further development of image matching and error detection methods. Example images have been successfully exported for similar use at other sites. Conclusions: Because absolute truth is known, digitally reconstructed electronic portal images with known setup errors are well suited for evaluation of computer-aided image matching and error detection methods. High-quality planning images, such as

  7. Satellite Maps Deliver More Realistic Gaming

    Science.gov (United States)

    2013-01-01

    When Redwood City, California-based Electronic Arts (EA) decided to make SSX, its latest snowboarding video game, it faced challenges in creating realistic-looking mountains. The solution was NASA's ASTER Global Digital Elevation Map, made available by the Jet Propulsion Laboratory, which EA used to create 28 real-life mountains from 9 different ranges for its award-winning game.

  8. Improving Intuition Skills with Realistic Mathematics Education

    Science.gov (United States)

    Hirza, Bonita; Kusumah, Yaya S.; Darhim; Zulkardi

    2014-01-01

    The intention of the present study was to see the improvement of students' intuitive skills. This improvement was seen by comparing the Realistic Mathematics Education (RME)-based instruction with the conventional mathematics instruction. The subject of this study was 164 fifth graders of elementary school in Palembang. The design of this study…

  9. 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.

  10. Realistic Simulation of Rice Plant

    Institute of Scientific and Technical Information of China (English)

    DING Wei-long; ZHANG Yu-ping; ZHANG Qian-yuan; ZHU De-feng; CHEN Qi

    2011-01-01

    The existing research results of virtual modeling of rice plant,however,is far from perfect compared to that of other crops due to its complex structure and growth process.Techniques to visually simulate the architecture of rice plant and its growth process are presented based on the analysis of the morphological characteristics at different stages.Firstly,the simulations of geometrical shape,the bending status and the structural distortion of rice leaves are conducted.Then,by using an improved model for bending deformation,the curved patterns of panicle axis and various types of panicle branches are generated,and the spatial shape of rice panicle is therefore created.Parametric L-system is employed to generate its topological structures,and finite-state automaton is adopted to describe the development of geometrical structures.Finally,the computer visualization of three-dimensional morphologies of rice plant at both organ and individual levels is achieved.The experimental results showed that the proposed methods of modeling the three-dimensional shapes of organs and simulating the growth of rice plant are feasible and effective,and the generated three-dimensional images are realistic.

  11. Should scientific realists be platonists?

    DEFF Research Database (Denmark)

    Busch, Jacob; Morrison, Joe

    2015-01-01

    Realists about are arrived at by any inferen- tial route which eschews causes (§3), and nor is there any direct pressure for Scientific Real- ists to change their inferential methods (§4). We suggest that in order to maintain inferential parity with Scientific Realism, proponents of EIA need to give......Enhanced Indispensability Arguments (EIA) claim that Scientific Realists are committed to the existence of mathematical entities due to their reliance on Inference to the Best Explana- tion (IBE). Our central question concerns this purported parity of reasoning: do people who defend the EIA make...... an appropriate use of the resources of Scientific Realism (in particular, IBE) to achieve platonism? (§2) We argue that just because a variety of different inferential strategies can be employed by Scientific Realists does not mean that ontological conclusions concerning which things we should be Scientific...

  12. Realistic Visualization of Virtual Views

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Computer Graphics allows us today to visualize in real-time innumerable and amazing scenarios with no limits on viewpoint and viewing direction. However, to design accurate object models and to simulate all the physical phenomena occurring in analogous real situations often represents a job...... 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...... phenomena captured in the reference photographs, (i.e. the transfer of photographic-realism). An overview of most prominent approaches in realistic virtual view synthesis will be presented and briefly discussed. Applications of proposed methods to visual survey, virtual cinematography, as well as mobile...

  13. Photo-Realistic Image Synthesis and Virtual Cinematography

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    : 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...

  14. Improving Intuition Skills with Realistic Mathematics Education

    OpenAIRE

    Bonita Hirza; Yaya S. Kusumah; Darhim; Zulkardi

    2014-01-01

    The intention of the present study was to see the improvement of students’ intuitive skills. This improvement was seen by comparing the Realistic Mathematics Education (RME)-based instruction with the conventional mathematics instruction. The subject of this study was 164 fifth graders of elementary school in Palembang. The design of this study was a Pretest-Posttest Control Group Experiment. Data was analyzed with the help of SPSS. The result of this study showed that there was differe...

  15. 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...

  16. Realistic behaviour simulation of a humanoid robot

    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 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...

  17. Realistic Machine Simulation with Virtual Reality

    OpenAIRE

    Neugebauer, R.; Klimant, P.; M. Witt

    2014-01-01

    Today highly complex components are manufactured on NC-controlled machine tools. The NC programs, controlling these machines, are usually automatically generated by CAM software. This automatic processing is often erroneous. The VR-based realistic machine simulation, presented in this paper, extends the usual content of a machine simulation, like material removal and collision detection, by various new aspects. The coupling of a real NC unit allows the recognition and elimination of all proce...

  18. 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.

  19. 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.

  20. 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....

  1. 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...

  2. Realist model approach to quantum mechanics

    Science.gov (United States)

    Hájíček, P.

    2013-06-01

    The paper proves that quantum mechanics is compatible with the constructive realism of modern philosophy of science. The proof is based on the observation that properties of quantum systems that are uniquely determined by their preparations can be assumed objective without the difficulties that are encountered by the same assumption about values of observables. The resulting realist interpretation of quantum mechanics is made rigorous by studying the space of quantum states—the convex set of state operators. Prepared states are classified according to their statistical structure into indecomposable and decomposable instead of pure and mixed. Simple objective properties are defined and showed to form a Boolean lattice.

  3. Realistic and efficient 2D crack simulation

    Science.gov (United States)

    Yadegar, Jacob; Liu, Xiaoqing; Singh, Abhishek

    2010-04-01

    Although numerical algorithms for 2D crack simulation have been studied in Modeling and Simulation (M&S) and computer graphics for decades, realism and computational efficiency are still major challenges. In this paper, we introduce a high-fidelity, scalable, adaptive and efficient/runtime 2D crack/fracture simulation system by applying the mathematically elegant Peano-Cesaro triangular meshing/remeshing technique to model the generation of shards/fragments. The recursive fractal sweep associated with the Peano-Cesaro triangulation provides efficient local multi-resolution refinement to any level-of-detail. The generated binary decomposition tree also provides efficient neighbor retrieval mechanism used for mesh element splitting and merging with minimal memory requirements essential for realistic 2D fragment formation. Upon load impact/contact/penetration, a number of factors including impact angle, impact energy, and material properties are all taken into account to produce the criteria of crack initialization, propagation, and termination leading to realistic fractal-like rubble/fragments formation. The aforementioned parameters are used as variables of probabilistic models of cracks/shards formation, making the proposed solution highly adaptive by allowing machine learning mechanisms learn the optimal values for the variables/parameters based on prior benchmark data generated by off-line physics based simulation solutions that produce accurate fractures/shards though at highly non-real time paste. Crack/fracture simulation has been conducted on various load impacts with different initial locations at various impulse scales. The simulation results demonstrate that the proposed system has the capability to realistically and efficiently simulate 2D crack phenomena (such as window shattering and shards generation) with diverse potentials in military and civil M&S applications such as training and mission planning.

  4. Editor's Introduction: Realist Methodology : A Review

    OpenAIRE

    Olsen, W K., Jamie Morgan.

    2010-01-01

    Critical realists offer a set of philosophical underpinnings for social research. Critical realists also engage constructively with social theory, but they are more than just theorists. In this chapter I list and describe various innovative methodological contributions made in recent years by realists. I point out ways in which research methods (i.e. techniques) fit with particular methodological assertions. There is a historical legacy of empiricism which critical realists often use as a foi...

  5. Realistic Solar Surface Convection Simulations

    Science.gov (United States)

    Stein, Robert F.; Nordlund, Ake

    2000-01-01

    We perform essentially parameter free simulations with realistic physics of convection near the solar surface. We summarize the physics that is included and compare the simulation results with observations. Excellent agreement is obtained for the depth of the convection zone, the p-mode frequencies, the p-mode excitation rate, the distribution of the emergent continuum intensity, and the profiles of weak photospheric lines. We describe how solar convection is nonlocal. It is driven from a thin surface thermal boundary layer where radiative cooling produces low entropy gas which forms the cores of the downdrafts in which most of the buoyancy work occurs. We show that turbulence and vorticity are mostly confined to the intergranular lanes and underlying downdrafts. Finally, we illustrate our current work on magneto-convection.

  6. REALISTIC CONCEPTION OF V.M. BEHTEREV

    Directory of Open Access Journals (Sweden)

    Korobkova S. N.

    2016-02-01

    Full Text Available In the focus of the article we have the philosophical concept of the outstanding scientist and social activist V.M. Behterev, which is considered as philosophical realism. Philosophical realism is a trend of Russian intellectual thought. It aims to study the nature and the man is substantial part of which. In this way, the realism is based on the anthropological tradition. Realistic ideology, which is developed by scientists, indicates the comprehension of the relationship of material and ideal in nature. To designate such connection the author proposes the concept of "philosophical conversion". Behterev's theory is positioned as a particular expression of philosophical realism in nature science, and it is termed by "evolutionary monism". It means a correlative connection of a total processes in nature. By analyzing the philosophical views of the scientist, the author concludes that psychic energy appears as a correlate of material and ideal and it is intermediated by humans. Psychic energy like other forms of energy is never destroyed and provides a social immortality of the man. The accumulation of mental energy leads to the creation of higher moral being named «progenerativ». The realistic concept of Behterev is interesting both a historical point of view and in the context of contemporary interdisciplinary efforts to comprehend the "second reality" of man, namely a virtual reality

  7. Centralized Cooperative Positioning and Tracking with Realistic Communications Constraints

    DEFF Research Database (Denmark)

    Mensing, Christian; Nielsen, Jimmy Jessen

    2010-01-01

    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....

  8. Non-Realistic Video Rendering

    OpenAIRE

    Johannesová, Daniela

    2012-01-01

    Práce se zabývá způsoby pro nerealistické zobrazení videa. Jsou zde shrnuty techniky pro zpracování videa, hlavní zaměření je na malířské techniky a zpracování videa těmito technikami. Pozornost je věnována jednotlivým operacím při zpracování snímku a způsobům pro zajištění koherence mezi snímky videa. Součástí práce je aplikace na zpracování videa, využívající knihovnu OpenCV. The thesis deals a with ways of non-realistic view of video. There are summarized video processing techniques in ...

  9. The Coupled Spectral Element/Normal Mode Method: Application to the Testing of Several Approximations Based on Normal Mode Theory for the Computation of Seismograms in a Realistic 3D Earth.

    Science.gov (United States)

    Capdeville, Y.; Gung, Y.; Romanowicz, B.

    2002-12-01

    The spectral element method (SEM) has recently been adapted successfully for global spherical earth wave propagation applications. Its advantage is that it provides a way to compute exact seismograms in a 3D earth, without restrictions on the size or wavelength of lateral heterogeneity at any depth, and can handle diffraction and other interactions with major structural boundaries. Its disadvantage is that it is computationally heavy. In order to partly address this drawback, a coupled SEM/normal mode method was developed (Capdeville et al., 2000). This enables us to more efficiently compute bodywave seismograms to realistically short periods (10s or less). In particular, the coupled SEM/normal mode method is a powerful tool to test the validity of some analytical approximations that are currently used in global waveform tomography, and that are considerably faster computationally. Here, we focus on several approximations based on normal mode perturbation theory: the classical "path-average approximation" (PAVA) introduced by Woodhouse and Dziewonski (1984) and well suited for fundamental mode surface waves (1D sensitivity kernels); the non-linear asymptotic coupling theory (NACT), which introduces coupling between mode branches and 2D kernels in the vertical plane containing the source and the receiver (Li and Tanimoto, 1993; Li and Romanowicz, 1995); an extension of NACT which includes out of plane focusing terms computed asymptotically (e.g. Romanowicz, 1987) and introduces 3D kernels; we also consider first order perturbation theory without asymptotic approximations, such as developed for example by Dahlen et al. (2000). We present the results of comparisons of realistic seismograms for different models of heterogeneity, varying the strength and sharpness of the heterogeneity and its location in depth in the mantle. We discuss the consequences of different levels of approximations on our ability to resolve 3D heterogeneity in the earth's mantle.

  10. Realistically Rendering SoC Traffic Patterns with Interrupt Awareness

    DEFF Research Database (Denmark)

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

    2005-01-01

    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 of...

  11. Progress in realistic LOCA analysis

    International Nuclear Information System (INIS)

    In 1988 the USNRC revised the ECCS rule contained in Appendix K and Section 50.46 of 10 CFR Part 50, which governs the analysis of the Loss Of Coolant Accident (LOCA). The revised regulation allows the use of realistic computer models to calculate the loss of coolant accident. In addition, the new regulation allows the use of high probability estimates of peak cladding temperature (PCT), rather than upper bound estimates. Prior to this modification, the regulations were a prescriptive set of rules which defined what assumptions must be made about the plant initial conditions and how various physical processes should be modeled. The resulting analyses were highly conservative in their prediction of the performance of the ECCS, and placed tight constraints on core power distributions, ECCS set points and functional requirements, and surveillance and testing. These restrictions, if relaxed, will allow for additional economy, flexibility, and in some cases, improved reliability and safety as well. For example, additional economy and operating flexibility can be achieved by implementing several available core and fuel rod designs to increase fuel discharge burnup and reduce neutron flux on the reactor vessel. The benefits of application of best estimate methods to LOCA analyses have typically been associated with reductions in fuel costs, resulting from optimized fuel designs, or increased revenue from power upratings. Fuel cost savings are relatively easy to quantify, and have been estimated at several millions of dollars per cycle for an individual plant. Best estimate methods are also likely to contribute significantly to reductions in O and M costs, although these reductions are more difficult to quantify. Examples of O and M cost reductions are: 1) Delaying equipment replacement. With best estimate methods, LOCA is no longer a factor in limiting power levels for plants with high tube plugging levels or degraded safety injection systems. If other requirements for

  12. SU-E-CAMPUS-I-05: Internal Dosimetric Calculations for Several Imaging Radiopharmaceuticals in Preclinical Studies and Quantitative Assessment of the Mouse Size Impact On Them. Realistic Monte Carlo Simulations Based On the 4D-MOBY Model

    Energy Technology Data Exchange (ETDEWEB)

    Kostou, T; Papadimitroulas, P; Kagadis, GC [University of Patras, Rion, Ahaia (Greece); Loudos, G [Technical Educational Institute of Athens, Aigaleo, Attiki (Greece)

    2014-06-15

    Purpose: Commonly used radiopharmaceuticals were tested to define the most important dosimetric factors in preclinical studies. Dosimetric calculations were applied in two different whole-body mouse models, with varying organ size, so as to determine their impact on absorbed doses and S-values. Organ mass influence was evaluated with computational models and Monte Carlo(MC) simulations. Methods: MC simulations were executed on GATE to determine dose distribution in the 4D digital MOBY mouse phantom. Two mouse models, 28 and 34 g respectively, were constructed based on realistic preclinical exams to calculate the absorbed doses and S-values of five commonly used radionuclides in SPECT/PET studies (18F, 68Ga, 177Lu, 111In and 99mTc).Radionuclide biodistributions were obtained from literature. Realistic statistics (uncertainty lower than 4.5%) were acquired using the standard physical model in Geant4. Comparisons of the dosimetric calculations on the two different phantoms for each radiopharmaceutical are presented. Results: Dose per organ in mGy was calculated for all radiopharmaceuticals. The two models introduced a difference of 0.69% in their brain masses, while the largest differences were observed in the marrow 18.98% and in the thyroid 18.65% masses.Furthermore, S-values of the most important target-organs were calculated for each isotope. Source-organ was selected to be the whole mouse body.Differences on the S-factors were observed in the 6.0–30.0% range. Tables with all the calculations as reference dosimetric data were developed. Conclusion: Accurate dose per organ and the most appropriate S-values are derived for specific preclinical studies. The impact of the mouse model size is rather high (up to 30% for a 17.65% difference in the total mass), and thus accurate definition of the organ mass is a crucial parameter for self-absorbed S values calculation.Our goal is to extent the study for accurate estimations in small animal imaging, whereas it is known

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    area. Rather than the classical semi-static and network-wise configuration, the importance of having highly dynamic and distributed mechanisms that are able to adapt to local environment conditions is revealed. We propose two promising cell association algorithms: one aiming at pure load balancing...... user association to offload more users to the picocells. However, its application to realistic irregular deployments opens a number of research questions. In this paper, we investigate the operation of eICIC in a realistic deployment based on three-dimensional data from a dense urban European capital...... 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...

  14. Realistic generation cost of solar photovoltaic electricity

    International Nuclear Information System (INIS)

    Solar photovoltaic (SPV) power plants have long working life with zero fuel cost and negligible maintenance cost but requires huge initial investment. The generation cost of the solar electricity is mainly the cost of financing the initial investment. Therefore, the generation cost of solar electricity in different years depends on the method of returning the loan. Currently levelized cost based on equated payment loan is being used. The static levelized generation cost of solar electricity is compared with the current value of variable generation cost of grid electricity. This improper cost comparison is inhibiting the growth of SPV electricity by creating wrong perception that solar electricity is very expensive. In this paper a new method of loan repayment has been developed resulting in generation cost of SPV electricity that increases with time like that of grid electricity. A generalized capital recovery factor has been developed for graduated payment loan in which capital and interest payment in each installment are calculated by treating each loan installment as an independent loan for the relevant years. Generalized results have been calculated which can be used to determine the cost of SPV electricity for a given system at different places. Results show that for SPV system with specific initial investment of 5.00 cents /kWh/year, loan period of 30 years and loan interest rate of 4% the levelized generation cost of SPV electricity with equated payment loan turns out to be 28.92 cents /kWh, while the corresponding generation cost with graduated payment loan with escalation in annual installment of 8% varies from 9.51 cents /kWh in base year to 88.63 cents /kWh in 30th year. So, in this case, the realistic current generation cost of SPV electricity is 9.51 cents /kWh and not 28.92 cents /kWh. Further, with graduated payment loan, extension in loan period results in sharp decline in cost of SPV electricity in base year. Hence, a policy change is required

  15. Probabilistic infrasound propagation using realistic atmospheric perturbations

    NARCIS (Netherlands)

    Smets, P.S.M.; Evers, L.G.; Näsholm, S.P.; Gibbons, S.J.

    2015-01-01

    This study demonstrates probabilistic infrasound propagation modeling using realistic perturbations. The ensembles of perturbed analyses, provided by the European Centre for Medium-Range Weather Forecasts (ECMWF), include error variances of both model and assimilated observations. Ensemble spread pr

  16. 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

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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.

  3. 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

  4. 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.

  5. Evolution of migration rate in a spatially realistic metapopulation model.

    OpenAIRE

    Heino,-M; Hanski,-I

    2001-01-01

    We use an individual-based, spatially realistic metapopulation model to study the evolution of migration rate. We first explore the consequences of habitat change in hypothetical patch networks on a regular lattice. If the primary consequence of habitat change is an increase in local extinction risk as a result of decreased local population sizes, migration rate increases. A nonmonotonic response, with migration rate decreasing at high extinction rate, was obtained only by assuming very frequ...

  6. Evolution of Migration Rate in a Spatially Realistic Metapopulation Model.

    OpenAIRE

    Heino, M.; Hanski, I.

    2000-01-01

    We use an individual-based, spatially realistic metapopulation model to study the evolution of migration rate. We first explore the evolutionary consequences of habitat change in hypothetical patch networks on a regular lattice. If the primary consequence of habitat change is an increase in local extinction risk due to decreased local population sizes, migration rate increases. A non-monotonic response, with migration rate decreasing at high extinction rate, was obtained only by assuming very...

  7. Realistic teleportation with linear optical elements

    OpenAIRE

    Trump, C.; Bruss, D.; Lewenstein, M.

    2000-01-01

    We calculate the highest possible information gain in a measurement of entangled states when employing a beamsplitter. The result is used to evaluate the fidelity, averaged over all unknown inputs, in a realistic teleportation protocol that takes account of the imperfect detection of Bell states. Finally, we introduce a probabilistic teleportation scheme, where measurements are made in a partially entangled basis.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Nuclear matter theory. [Realistic forces, review

    Energy Technology Data Exchange (ETDEWEB)

    Negele, J.W.

    1977-01-01

    Recent advances in variational and perturbative theories are surveyed which offer genuine promise that nuclear matter will soon become a viable tool for investigating nuclear interactions. The basic elements of the hypernetted chain expansion for Jastrow variational functions are briefly reviewed, and comparisons of variational and perturbative results for a series of increasingly complicated systems are presented. Prospects for investigating realistic forces are assessed and the unresolved, open problems are summarized.

  13. 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.

  14. 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

  15. 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.

  16. Realistic inflation models and primordial gravity waves

    Science.gov (United States)

    Rehman, Mansoor Ur

    We investigate both supersymmetric and non-supersymmetric realistic models of inflation. In non-supersymmetric models, inflation is successfully realized by employing both Coleman Weinberg and Higgs potentials in GUTs such as SU(5) and SO(10). The quantum smearing of tree level predictions is discussed in the Higgs inflation. These quantum corrections can arise from the inflaton couplings to other particles such as GUT scalars. As a result of including these corrections, a reduction in the tensor-to-scalar ratio r, a canonical measure of gravity waves produced during inflation, is observed. In a simple phi4 chaotic model, we reconsider a non-minimal (xi > 0) gravitationalcoupling of inflaton φ arising from the interaction xi R phi2, where R is the Ricci scalar. In estimating bounds on various inflationaryparameters we also include quantum corrections. We emphasize that while working with high precision observations such as the current Planck satellite experiment we cannot ignore these radiative and gravitational corrections in analyzing the predictions of various inflationary models. In supersymmetric hybrid inflation with minimal Kahler potential, the soft SUSY breaking terms are shown to play an important role in realizing inflation consistent with the latest WMAP data. The SUSY hybrid models which we consider here predict exceedingly small values of r. However, to obtain observable gravity waves the non-minimal Kahler potential turns out to be a necessary ingredient. A realistic model of flipped SU(5) model, which benefits from the absence of topological defects, is considered in the standard SUSY hybrid inflation. We also present a discussion of shifted hybrid inflation in a realistic model of SUSY SU(5) GUT.

  17. Pairing and realistic shell-model interactions

    OpenAIRE

    Covello, A; Gargano, A.; Kuo, T. T. S.

    2012-01-01

    This paper starts with a brief historical overview of pairing in nuclei, which fulfills the purpose of properly framing the main subject. This concerns the pairing properties of a realistic shell-model effective interaction which has proved very successful in describing nuclei around doubly magic 132Sn. We focus attention on the two nuclei 134Te and 134Sn with two valence protons and neutrons, respectively. Our study brings out the key role of one particle-one hole excitations in producing a ...

  18. 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.

  19. 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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    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....... 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...

  1. Effects of realistic partial state densities on preequilibrium decay

    International Nuclear Information System (INIS)

    We reported earlier on the inclusion in code ALICE of a subroutine which calculates partial state densities for preequilibrium decay using realistic single particle levels. In this work we present results using single particle levels due to Seegar-Howard and Seegar-Perisho. Since the earlier work, we have modified the intranuclear transition rates for nucleon scattering based on the final density of three exciton states available. We summarize the changes made in the hybrid subroutine of ALICE and present our results. 5 refs., 1 fig

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

    CERN Document Server

    Nakada, H; Inakura, T; Margueron, J

    2016-01-01

    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 realistic interaction, which is derived from the base $2N$ and $3N$ interaction, furnish a new theoretical instrument for advancing nuclear mean-field approaches.

  3. 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).

  4. Operator representation for effective realistic interactions

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Dennis; Feldmeier, Hans; Neff, Thomas [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)

    2013-07-01

    We present a method to derive an operator representation from the partial wave matrix elements of effective realistic nucleon-nucleon potentials. This method allows to employ modern effective interactions, which are mostly given in matrix element representation, also in nuclear many-body methods requiring explicitly the operator representation, for example ''Fermionic Molecular Dynamics'' (FMD). We present results for the operator representation of effective interactions obtained from the Argonne V18 potential with the Uenitary Correlation Operator Method'' (UCOM) and the ''Similarity Renormalization Group'' (SRG). Moreover, the operator representation allows a better insight in the nonlocal structure of the potential: While the UCOM transformed potential only shows a quadratic momentum dependence, the momentum dependence of SRG transformed potentials is beyond such a simple polynomial form.

  5. 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...

  6. 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.

  7. 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.

  8. Helioseismology of a Realistic Magnetoconvective Sunspot Simulation

    Science.gov (United States)

    Braun, D. C.; Birch, A. C.; Rempel, M.; Duvall, T. L., Jr.

    2012-01-01

    We compare helioseismic travel-time shifts measured from a realistic magnetoconvective sunspot simulation using both helioseismic holography and time-distance helioseismology, and measured from real sunspots observed with the Helioseismic and Magnetic Imager instrument on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observatory. We find remarkable similarities in the travel-time shifts measured between the methodologies applied and between the simulated and real sunspots. Forward modeling of the travel-time shifts using either Born or ray approximation kernels and the sound-speed perturbations present in the simulation indicates major disagreements with the measured travel-time shifts. These findings do not substantially change with the application of a correction for the reduction of wave amplitudes in the simulated and real sunspots. Overall, our findings demonstrate the need for new methods for inferring the subsurface structure of sunspots through helioseismic inversions.

  9. 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.

  10. MetAssimulo:Simulation of Realistic NMR Metabolic Profiles

    Directory of Open Access Journals (Sweden)

    De Iorio Maria

    2010-10-01

    Full Text Available Abstract Background Probing the complex fusion of genetic and environmental interactions, metabolic profiling (or metabolomics/metabonomics, the study of small molecules involved in metabolic reactions, is a rapidly expanding 'omics' field. A major technique for capturing metabolite data is 1H-NMR spectroscopy and this yields highly complex profiles that require sophisticated statistical analysis methods. However, experimental data is difficult to control and expensive to obtain. Thus data simulation is a productive route to aid algorithm development. Results MetAssimulo is a MATLAB-based package that has been developed to simulate 1H-NMR spectra of complex mixtures such as metabolic profiles. Drawing data from a metabolite standard spectral database in conjunction with concentration information input by the user or constructed automatically from the Human Metabolome Database, MetAssimulo is able to create realistic metabolic profiles containing large numbers of metabolites with a range of user-defined properties. Current features include the simulation of two groups ('case' and 'control' specified by means and standard deviations of concentrations for each metabolite. The software enables addition of spectral noise with a realistic autocorrelation structure at user controllable levels. A crucial feature of the algorithm is its ability to simulate both intra- and inter-metabolite correlations, the analysis of which is fundamental to many techniques in the field. Further, MetAssimulo is able to simulate shifts in NMR peak positions that result from matrix effects such as pH differences which are often observed in metabolic NMR spectra and pose serious challenges for statistical algorithms. Conclusions No other software is currently able to simulate NMR metabolic profiles with such complexity and flexibility. This paper describes the algorithm behind MetAssimulo and demonstrates how it can be used to simulate realistic NMR metabolic profiles with

  11. The Research on Plant's Realistic Modeling Method%植物真实感建模方法研究

    Institute of Scientific and Technical Information of China (English)

    毛卫强; 耿卫东; 潘云鹤

    2000-01-01

    Plant's 3D structure is quite complex. This paper presents an Open Synthetic Plant Modeling Method. It includes three parts:plant's realistic representation model,synthetic modeling method and realistic display method. Branch is the base element of plant's realistic representation model and is simulated by cublic parameter surface. The synthetic modeling method is implemented by interactively using several simulation methods in the growth procedure of plant. Bark texture and leaf are added to realistically display the plant's 3D structure, Four test examples indicate that this method is feasible in plant's 3D modeling.

  12. 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.

  13. 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.

  14. 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.

  15. Arguments and elements of realistic interpretation of mathematics: arithmetical component

    Directory of Open Access Journals (Sweden)

    Arepiev E. I.

    2015-01-01

    Full Text Available The prospects for realistic interpretation of the nature of initial mathematical truths and objects are considered in the article. The arguments of realism, reasons impeding its recognition among philosophers of mathematics as well as the ways to eliminate these reasons are discussed. It is proven that the absence of acceptable ontological interpretation of mathematical realism is the main obstacle to its recognition. This paper explicates the introductory positions of this interpretation and presents a realistic interpretation of the arithmetical component of mathematics. In summary, we should like to note that such constructions, as it is shown to us, ought to bring the direct use not only for the philosophical foundation of mathematics but for mathematics itself. In the justification of the author's conclusions based on the works of famous mathematicians of the twentieth century, interpreting their findings in a broad historical and philosophical context. To illustrate his point, the author gives examples of arithmetic and geometry - both Euclidean and non-Euclidean.

  16. Simulation of Combustion Systems with Realistic g-jitter

    Science.gov (United States)

    Mell, William E.; McGrattan, Kevin B.; Baum, Howard R.

    2003-01-01

    In this project a transient, fully three-dimensional computer simulation code was developed to simulate the effects of realistic g-jitter on a number of combustion systems. The simulation code is capable of simulating flame spread on a solid and nonpremixed or premixed gaseous combustion in nonturbulent flow with simple combustion models. Simple combustion models were used to preserve computational efficiency since this is meant to be an engineering code. Also, the use of sophisticated turbulence models was not pursued (a simple Smagorinsky type model can be implemented if deemed appropriate) because if flow velocities are large enough for turbulence to develop in a reduced gravity combustion scenario it is unlikely that g-jitter disturbances (in NASA's reduced gravity facilities) will play an important role in the flame dynamics. Acceleration disturbances of realistic orientation, magnitude, and time dependence can be easily included in the simulation. The simulation algorithm was based on techniques used in an existing large eddy simulation code which has successfully simulated fire dynamics in complex domains. A series of simulations with measured and predicted acceleration disturbances on the International Space Station (ISS) are presented. The results of this series of simulations suggested a passive isolation system and appropriate scheduling of crew activity would provide a sufficiently "quiet" acceleration environment for spherical diffusion flames.

  17. 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...

  18. Realistic anomaly mediation with bulk gauge fields

    International Nuclear Information System (INIS)

    We present a simple general framework for realistic models of supersymmetry breaking driven by anomaly mediation. We consider a 5-dimensional 'brane universe' where the visible and hidden sectors are localized on different branes, and the standard model gauge bosons propagate in the bulk. In this framework there can be charged scalar messengers that have contact interactions with the hidden sector, either localized in the hidden sector or in the bulk. These scalars obtain soft masses that feed into visible sector scalar masses at two loop order via bulk gauge interactions. This contribution is automatically flavor-blind, and can be naturally positive. If the messengers are in the bulk this contribution is automatically the same order of magnitude as the anomaly mediated contribution, independent of the brane spacing. If the messengers are localized to a brane the two effects are of the same order for relatively small brane spacings. The gaugino masses and A terms are determined completely by anomaly mediation. In order for anomaly mediation to dominate over radion mediation the radion must be is stabilized in a manner that preserves supersymmetry, with supergravity effects included. We show that this occurs in simple models. We also show that the mu problem can be solved by the vacuum expectation value of a singlet in this framework. (author)

  19. Differentiability of correlations in realistic quantum mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera, Alejandro [Instituto de Matemática, UFRJ, CEP 21941-909 Rio de Janeiro, Rio de Janeiro (Brazil); Faria, Edson de [Instituto de Matemática e Estatística, USP, Rua do Matão 1010, SP 05508-090 São Paulo, São Paulo (Brazil); Pujals, Enrique [IMPA, Estrada Dona Castorina 110, 22460-320 Rio de Janeiro, Rio de Janeiro (Brazil); Tresser, Charles [IBM, P.O. Box 218, Yorktown Heights, New York 10598 (United States)

    2015-09-15

    We prove a version of Bell’s theorem in which the locality assumption is weakened. We start by assuming theoretical quantum mechanics and weak forms of relativistic causality and of realism (essentially the fact that observable values are well defined independently of whether or not they are measured). Under these hypotheses, we show that only one of the correlation functions that can be formulated in the framework of the usual Bell theorem is unknown. We prove that this unknown function must be differentiable at certain angular configuration points that include the origin. We also prove that, if this correlation is assumed to be twice differentiable at the origin, then we arrive at a version of Bell’s theorem. On the one hand, we are showing that any realistic theory of quantum mechanics which incorporates the kinematic aspects of relativity must lead to this type of rough correlation function that is once but not twice differentiable. On the other hand, this study brings us a single degree of differentiability away from a relativistic von Neumann no hidden variables theorem.

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

    KAUST Repository

    Parshad, Rana D.

    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. 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.

  2. 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.

  3. Breaking with fun, educational and realistic learning games

    DEFF Research Database (Denmark)

    Duus Henriksen, Thomas

    2009-01-01

    for teaching change management and change implementation. The EIS is played in groups, who share the game on a computer, and played by making change decisions in order to implement an IT system in an organisation. In this study, alternative participatory incentives, means for creating learning processes......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...... and understandings of the game-based learning process proved much more influential to both how and what was learned. Findings indicate that the game might have been intended to be fun, but it was it's staged relevance that incited participation; the game might hold an academic content, but it was the interplay...

  4. 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.

  5. Limiting angular velocity of realistic relativistic neutron star models

    Energy Technology Data Exchange (ETDEWEB)

    Weber, F.; Glendenning, N.K. (California Univ., Berkeley (USA). Div. of Nuclear Science)

    1991-05-01

    The Keplerian velocity as well as those frequencies at which instability against gravitational radiation-reaction sets in are calculated for rotating neutron star models of gravitational mass 1.5 M{sub sun}. The investigation is based on four different, realistic neutron star matter equations of state. Our results indicate that the gravitational radiation instability sets in well below (i.e., 63-71% of) the Keplerian frequency, and that young neutron stars are limited to rotational periods greater than about 1 ms. In young and therefore hot (T {approx equal} 10{sup 10} K) neutron stars the m = 5 (+- 1) modes and in old stars after being spun up and reheated by mass accretion, the m = 4 and/or m = 3 modes may set the limit on stable rotation. (orig.).

  6. 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.

  7. 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.

  8. 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

  9. Atomic entanglement near a realistic microsphere

    OpenAIRE

    Dung, Ho Trung; Scheel, S.; Welsch, D-G; Knöll, L

    2001-01-01

    We study a scheme for entangling two-level atoms located close to the surface of a dielectric microsphere. The effect is based on medium-assisted spontaneous decay, rigorously taking into account dispersive and absorptive properties of the microsphere. We show that even in the weak-coupling regime, where the Markov approximation applies, entanglement up to 0.35 ebits between two atoms can be created. However, larger entanglement and violation of Bell's inequality can only be achieved in the s...

  10. Importance of realistic mobility models for vanet network simulation

    OpenAIRE

    Boukenadil, Bahidja

    2014-01-01

    In the performance evaluation of a protocol for a vehicular ad hoc network, the protocol should be tested under a realistic conditions including, representative data traffic models, and realistic movements of the mobile nodes which are the vehicles (i.e., a mobility model). This work is a comparative study between two mobility models that are used in the simulations of vehicular networks, i.e., MOVE (MObility model generator for VEhicular networks) and CityMob, a mobility pattern generator fo...

  11. ON THE REALISTIC STOCHASTIC MODEL OF GPS OBSERVABLES: IMPLEMENTATION AND PERFORMANCE

    Directory of Open Access Journals (Sweden)

    F. Zangeneh-Nejad

    2015-12-01

    Full Text Available High-precision GPS positioning requires a realistic stochastic model of observables. A realistic GPS stochastic model of observables should take into account different variances for different observation types, correlations among different observables, the satellite elevation dependence of observables precision, and the temporal correlation of observables. Least-squares variance component estimation (LS-VCE is applied to GPS observables using the geometry-based observation model (GBOM. To model the satellite elevation dependent of GPS observables precision, an exponential model depending on the elevation angles of the satellites are also employed. Temporal correlation of the GPS observables is modelled by using a first-order autoregressive noise model. An important step in the high-precision GPS positioning is double difference integer ambiguity resolution (IAR. The fraction or percentage of success among a number of integer ambiguity fixing is called the success rate. A realistic estimation of the GNSS observables covariance matrix plays an important role in the IAR. We consider the ambiguity resolution success rate for two cases, namely a nominal and a realistic stochastic model of the GPS observables using two GPS data sets collected by the Trimble R8 receiver. The results confirm that applying a more realistic stochastic model can significantly improve the IAR success rate on individual frequencies, either on L1 or on L2. An improvement of 20% was achieved to the empirical success rate results. The results also indicate that introducing the realistic stochastic model leads to a larger standard deviation for the baseline components by a factor of about 2.6 on the data sets considered.

  12. On the Realistic Stochastic Model of GPS Observables: Implementation and Performance

    Science.gov (United States)

    Zangeneh-Nejad, F.; Amiri-Simkooei, A. R.; Sharifi, M. A.; Asgari, J.

    2015-12-01

    High-precision GPS positioning requires a realistic stochastic model of observables. A realistic GPS stochastic model of observables should take into account different variances for different observation types, correlations among different observables, the satellite elevation dependence of observables precision, and the temporal correlation of observables. Least-squares variance component estimation (LS-VCE) is applied to GPS observables using the geometry-based observation model (GBOM). To model the satellite elevation dependent of GPS observables precision, an exponential model depending on the elevation angles of the satellites are also employed. Temporal correlation of the GPS observables is modelled by using a first-order autoregressive noise model. An important step in the high-precision GPS positioning is double difference integer ambiguity resolution (IAR). The fraction or percentage of success among a number of integer ambiguity fixing is called the success rate. A realistic estimation of the GNSS observables covariance matrix plays an important role in the IAR. We consider the ambiguity resolution success rate for two cases, namely a nominal and a realistic stochastic model of the GPS observables using two GPS data sets collected by the Trimble R8 receiver. The results confirm that applying a more realistic stochastic model can significantly improve the IAR success rate on individual frequencies, either on L1 or on L2. An improvement of 20% was achieved to the empirical success rate results. The results also indicate that introducing the realistic stochastic model leads to a larger standard deviation for the baseline components by a factor of about 2.6 on the data sets considered.

  13. 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

  14. 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...

  15. Coniferous Canopy BRF Simulation Based on 3-D Realistic Scene

    Science.gov (United States)

    Wang, Xin-yun; Guo, Zhi-feng; Qin, Wen-han; 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 investigate d in the present study. It makes the computer simulation methods such as L-systems and radiosity-graphics combined method (RGM) more powerf ul 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 refle ctance factor) in visible and near-infrared regions. Results in this study show that in most cases both agreed well. Meanwhiie at a tree and forest level. the results are also good.

  16. 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...

  17. 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.

  18. 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.

  19. Karstification beneath dam sites: From conceptual models to realistic scenarios

    Science.gov (United States)

    Hiller, Thomas; Kaufmann, Georg; Romanov, Douchko

    2010-05-01

    Dam sites located above soluble rock such as limestone or gypsum can leak in relatively short times (tenths of years), when compared to the natural time scale of karstification (10.000-100.000 years). The reason for this leakage is the high hydraulic gradient imposed by the reservoir that drives aggressive water through the fracture and fissure system of the bedrock and this aggressive water dissolves the rock and increases permeability fairly fast. Thus, on the one hand water losses through enlarged fractures can become a problem for the reservoir. On the other hand, the void space itself can be a risk for the dam structure above. This may have unpredictable ecological and economical consequences. We present a three-dimensional conceptual model study of karstification in dam-site areas on limestone bedrock. We compare our three-dimensional model to a standard two-dimensional dam site model to verify the results of our code. We further carry out a sensitivity analysis on the physical and chemical parameters driving the karstification to derive an empirical formulation of the breakthrough time TB. In a next step we implement a statistical fracture network and topography to approach a more realistic scenario. Finally we show the results of a three dimensional model based on a real dam site.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. Using polychromatic X-radiography to examine realistic imitation firearms.

    Science.gov (United States)

    Austin, J C; Day, C R; Kearon, A T; Valussi, S; Haycock, P W

    2008-10-25

    Sections 36-41 of the Violent Crimes Reduction Act (2006), which came into force in England and Wales on 1st October 2007, have placed significant restrictions on the sale and possession of 'realistic imitation firearms'. This legislation attempts to produce a definition of a 'realistic imitation' which clearly differentiates these items from other imitation firearms (which are not covered by the legislation). This paper will go a stage further by demonstrating techniques by which blank firing realistic imitation firearms which may be suitable for illegal conversion to fire live rounds may be differentiated from other less 'suitable' (but visually identical) realistic imitations. The article reports on the use of X-radiography, utilizing the bremsstrahlung of a commercial broad spectrum X-ray source, to identify the differences between alloys constituting the barrels of distinct replica and/or blank firing handguns. The resulting pseudo-signatures are transmission spectra over a range from 20 to 75 kV, taken at 1 kV intervals, which are extracted from stacks of registered, field flattened images. It is shown that it is possible to quantify differences between transmission spectra for components of different realistic imitation fire arms, and apply the results to determine the suitability of particular gun barrels from blank firing imitation firearms for illegal conversion to fire live rounds, or related illegal modifications. PMID:18842365

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

    Science.gov (United States)

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

    2016-08-01

    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.

  7. 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.

  8. Campus Culture Construction Working Mechanism Based on"Serve in Realistic Job"Practice--Take Guangxi University of Finance and Economics as an example%基于“实岗挂职”实践的校园文化建设工作机制--以广西财经学院以例

    Institute of Scientific and Technical Information of China (English)

    蒲青江

    2015-01-01

    大学生社会实践是大学教育中不可或缺的重要组成部分,而大学生利用假期到地方挂职锻炼则是近年新发展起来的创新性实践模式。本文以广西财经学院为例,阐释了基于“实岗挂职”锻炼的校园文化建设工作机制和实践模式,旨在探讨实现校园文化建设、地方社会发展、学生能力提升“三赢”的有效途径。%Social practice of university education is an important integral part of, and college students take advantage of the holidays to local testing exercise is an innovative new practice models developed in recent years. In this paper, Guangxi Uni-versity of Finance and Economics, for example, based on an effective way to explain the"serve in realistic job"to exercise the working mechanism construction of campus culture and practice patterns, aims to explore the effective way of cultural construction of campus, local community development, to enhance students' ability"three win".

  9. 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.

  10. 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.

  11. 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...

  12. 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....

  13. 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

  14. Realistic camera noise modeling with application to improved HDR synthesis

    Science.gov (United States)

    Goossens, Bart; Luong, Hiêp; Aelterman, Jan; Pižurica, Aleksandra; Philips, Wilfried

    2012-12-01

    Due to the ongoing miniaturization of digital camera sensors and the steady increase of the "number of megapixels", individual sensor elements of the camera become more sensitive to noise, even deteriorating the final image quality. To go around this problem, sophisticated processing algorithms in the devices, can help to maximally exploit the knowledge on the sensor characteristics (e.g., in terms of noise), and offer a better image reconstruction. Although a lot of research focuses on rather simplistic noise models, such as stationary additive white Gaussian noise, only limited attention has gone to more realistic digital camera noise models. In this article, we first present a digital camera noise model that takes several processing steps in the camera into account, such as sensor signal amplification, clipping, post-processing,.. We then apply this noise model to the reconstruction problem of high dynamic range (HDR) images from a small set of low dynamic range (LDR) exposures of a static scene. In literature, HDR reconstruction is mostly performed by computing a weighted average, in which the weights are directly related to the observer pixel intensities of the LDR image. In this work, we derive a Bayesian probabilistic formulation of a weighting function that is near-optimal in the MSE sense (or SNR sense) of the reconstructed HDR image, by assuming exponentially distributed irradiance values. We define the weighting function as the probability that the observed pixel intensity is approximately unbiased. The weighting function can be directly computed based on the noise model parameters, which gives rise to different symmetric and asymmetric shapes when electronic noise or photon noise is dominant. We also explain how to deal with the case that some of the noise model parameters are unknown and explain how the camera response function can be estimated using the presented noise model. Finally, experimental results are provided to support our findings.

  15. A realistic model for complex networks with local interaction, self-organization and order

    Institute of Scientific and Technical Information of China (English)

    Chen Fei; Chen Zeng-Qiang; Yuan Zhu-Zhi

    2007-01-01

    In this paper, a new mechanism for the emergence of scale-free distribution is proposed. It is more realistic than the existing mechanism. Based on our mechanism, a model responsible for the scale-free distribution with an exponent in a range of 3-to-5 is given. Moreover, this model could also reproduce the exponential distribution that is discovered in some real networks. Finally, the analytical result of the model is given and the simulation shows the validity of our result.

  16. Near-field SAR for signature and camouflage evaluation in realistic backgrounds

    OpenAIRE

    Larsson, Christer; Jersblad, Johan

    2011-01-01

    Outdoor ranges are commonly used for accurate RCS measurements of full scale vehicles with or without camouflage. Furthermore, ISAR processing is often used to obtain high quality imagery of the objects. However, these images do not show the vehicles in the environment where they are supposed to operate. This paper describes a ground based SAR system that is used to make accurate measurements on vehicles or other objects in realistic backgrounds. A transportable short range SAR measurement...

  17. 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.

  18. Simulation and assessment of realistic breast lesions using fractal growth models.

    OpenAIRE

    Rashidnasab, A; Elangovan, P.; Yip, M.; Diaz, O; Dance, DR; Young, KC; Wells, K

    2013-01-01

    A new method of generating realistic three dimensional simulated breast lesions known as diffusion limited aggregation (DLA) is presented, and compared with the random walk (RW) method. Both methods of lesion simulation utilize a physics-based method for inserting these simulated lesions into 2D clinical mammogram images that takes into account the polychromatic x-ray spectrum, local glandularity and scatter. DLA and RW masses were assessed for realism via a receiver operating characteristic ...

  19. Hybrid genetic algorithms: solutions in realistic dynamic and setup dependent job-shop scheduling problems

    OpenAIRE

    Rogério M. Branco; Antônio S. Coelho; Sérgio F. Mayerle

    2016-01-01

    This paper discusses the application of heuristic-based evolutionary technique in search for solutions concerning the dynamic job-shop scheduling problems with dependent setup times and alternate routes. With a combinatorial nature, these problems belong to an NP-hard class, with an aggravated condition when in realistic, dynamic and therefore, more complex cases than the traditional static ones. The proposed genetic algorithm executes two important functions: choose the routes using dispatch...

  20. A Realistic Treatment of Geomagnetic Cherenkov Radiation from Cosmic Ray Air Showers

    OpenAIRE

    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 treatment of the index of refraction in air, given by the law of Gladstone and Dale, which affects the pulses enormously for certain configurations, compared to a simplified treatment using a const...

  1. Quantum communication with photon-number entangled states and realistic photodetection

    CERN Document Server

    Usenko, Vladyslav C

    2010-01-01

    We address the effects of realistic photodetection, with nonunit quantum efficiency and background noise (dark counts), on the performances of quantum communication schemes based on photon-number entangled states. We consider channels based on Gaussian twin-beam states and non-Gaussian two-mode coherent states and evaluate the channel capacity by optimizing the bit discrimination threshold. We found that TWB-based channels are more robust against noise than TMC-based ones and that this result is almost independent on the statistics of dark counts.

  2. 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…

  3. Synthesis Of Realistic Animations Of A Person Speaking

    Science.gov (United States)

    Scott, Kenneth C.; Kagels, David S.; Watson, Stephen H.; Rom, Hillel S.; Lorre, Jean J.; Wright, John R.; Duxbury, Elizabeth D.

    1995-01-01

    Actors computer program implements automated process that synthesizes realistic animations of person speaking. Produces "newscaster" type video sequences. Uses images of person and, therefore, not limited to cartoons and cartoonlike movies. Potential applications also include use of process for automatically producing on-the-fly animations for human/computer interfaces and for reducing bandwidth needed to transmit video telephone signals.

  4. 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)

  5. 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 compute...

  6. Realistic glottal motion and airflow rate during human breathing.

    Science.gov (United States)

    Scheinherr, Adam; Bailly, Lucie; Boiron, Olivier; Lagier, Aude; Legou, Thierry; Pichelin, Marine; Caillibotte, Georges; Giovanni, Antoine

    2015-09-01

    The glottal geometry is a key factor in the aerosol delivery efficiency for treatment of lung diseases. However, while glottal vibrations were extensively studied during human phonation, the realistic glottal motion during breathing is poorly understood. Therefore, most current studies assume an idealized steady glottis in the context of respiratory dynamics, and thus neglect the flow unsteadiness related to this motion. This is particularly important to assess the aerosol transport mechanisms in upper airways. This article presents a clinical study conducted on 20 volunteers, to examine the realistic glottal motion during several breathing tasks. Nasofibroscopy was used to investigate the glottal geometrical variations simultaneously with accurate airflow rate measurements. In total, 144 breathing sequences of 30s were recorded. Regarding the whole database, two cases of glottal time-variations were found: "static" or "dynamic" ones. Typically, the peak value of glottal area during slow breathing narrowed from 217 ± 54 mm(2) (mean ± STD) during inspiration, to 178 ± 35 mm(2) during expiration. Considering flow unsteadiness, it is shown that the harmonic approximation of the airflow rate underevaluates the inertial effects as compared to realistic patterns, especially at the onset of the breathing cycle. These measurements provide input data to conduct realistic numerical simulations of laryngeal airflow and particle deposition. PMID:26159687

  7. Efficient calculation method for realistic deep 3D scene hologram using orthographic projection

    Science.gov (United States)

    Igarashi, Shunsuke; Nakamura, Tomoya; Matsushima, Kyoji; Yamaguchi, Masahiro

    2016-03-01

    We propose a fast calculation method to synthesize a computer-generated hologram (CGH) of realistic deep three-dimensional (3D) scene. In our previous study, we have proposed a calculation method of CGH for reproducing such scene called ray-sampling-plane (RSP) method, in which light-ray information of a scene is converted to wavefront, and the wavefront is numerically propagated based on diffraction theory. In this paper, we introduce orthographic projection to the RSP method for accelerating calculation time. By numerical experiments, we verified the accelerated calculation with the ratio of 28-times compared to the conventional RSP method. The calculated CGH was fabricated by the printing system using laser lithography and demonstrated deep 3D image reconstruction in 52mm×52mm with realistic appearance effect such as gloss and translucent effect.

  8. 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.

  9. 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

  10. 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 ...

  11. Realistic electricity market simulator for energy and economic studies

    Energy Technology Data Exchange (ETDEWEB)

    Bernal-Agustin, Jose L. [University of Zaragoza, C/Maria de Luna, 3, Zaragoza 50018 (Spain); Contreras, Javier; Conejo, Antonio J. [University of Castilla-La Mancha, Campus Universitario s/n, Ciudad Real 13071 (Spain); Martin-Flores, Raul [Airbus Spain S.L., Paseo John Lennon, Getafe 28906 (Spain)

    2007-01-15

    Electricity market simulators have become a useful tool to train engineers in the power industry. With the maturing of electricity markets throughout the world, there is a need for sophisticated software tools that can replicate the actual behavior of power markets. In most of these markets, power producers/consumers submit production/demand bids and the Market Operator clears the market producing a single price per hour. What makes markets different from each other are the bidding rules and the clearing algorithms to balance the market. This paper presents a realistic simulator of the day-ahead electricity market of mainland Spain. All the rules that govern this market are modeled. This simulator can be used either to train employees by power companies or to teach electricity markets courses in universities. To illustrate the tool, several realistic case studies are presented and discussed. (author)

  12. 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.

  13. 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.

  14. 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.

  15. The construction of `So What?? criminology: a realist analysis

    OpenAIRE

    Matthews, Roger A.

    2010-01-01

    Abstract From a realist perspective there is a growing body of criminology that can be classified as `So What?? criminology in that it involves a low level of theorisation, thin, inconsistent or vague concepts and categories, embodies a dubious methodology or has little or no policy relevance. The production of `So What?? criminology is, of course, no accident but the outcome of a number of lines of force that have served to shape the nature of mainstream academic criminology in re...

  16. Are Drivers' Comparative Risk Judgments about spending Realistic?

    OpenAIRE

    Delhomme, P.; Verlhiac, Jf; Martha, C.

    2009-01-01

    We examined how these drivers assess their risk of sanctions and their risk of causing an automobile crash because of speeding in comparison to the estimated risks of other drivers, and how realistic their comparative risk judgments are. We measured the relationship between the drivers' comparative risk judgments, self-reported speeding, and driving-related sensation-seeking. We hypothesized that they would think they have less risk of sanctions and of causing a car accident than others, and ...

  17. 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.

  18. Optimal control of photoelectron emission by realistic waveforms

    OpenAIRE

    Solanpää, Janne; Ciappina, Marcelo F.; 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 th...

  19. Plastinated nasal model: a new concept of anatomically realistic cast.

    OpenAIRE

    Durand, Marc; Pourchez, Jérémie; Louis, Bruno; Pouget, Jean-François; Isabey, Daniel; Coste, André; Prades, Jean-Michel; Rusch, Philippe; Cottier, Michèle

    2011-01-01

    BACKGROUND: For many years, researchers have been interested in investigating airflow and aerosol deposition in the nasal cavities. The nasal airways appear to be a complex geometrical system. Thus, in vitro experimental studies are frequently conducted with a more or less biomimetic nasal replica. AIM: This study is devoted to the development of an anatomically realistic nose model with bilateral nasal cavities, i.e. nasal anatomy, airway geometry and aerodynamic properties as close as possi...

  20. Synthetic Seismograms in Realistic Media : A Wave-theoretical Approach

    OpenAIRE

    Kohketsu, Kazuki

    1988-01-01

    In order to interpret seismograms, we should separate the effects of source and medium, which are strongly coupled. The medium effect is usually estimated by computing synthetic seismograms for a model of the Earth. Of course, a three-dimensionally heterogeneous, arbitrarily anisotropic and attenuative medium is the most realistic model, but it requires a great deal of theoretical and numerical effort. At present one- or two-dimensionally layered, isotropic and attenuative media consisting of...

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

    Science.gov (United States)

    Rovelli, Carlo

    2016-07-01

    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.

  2. QUANTUM KEY DISTRIBUTION WITH REALISTIC HERALDED SINGLE-PHOTON SOURCES

    OpenAIRE

    Lasota, Mikolaj; Demkowicz-Dobrzanski, Rafal; Banaszek, Konrad

    2013-01-01

    We analyze theoretically performance of four-state quantum key distribution protocols implemented with a realistic heralded single-photon source. The analysis assumes a noisy model for the detector heralding generation of individual photons via spontaneous parametric down-conversion, including dark counts and imperfect photon number resolution. We identify characteristics of the heralding detector that defines the attainable cryptographic key rate and the maximum secure distance. Approximate ...

  3. Numerical Modeling of Earthquake Dynamic Rupture : Requirements for Realistic Modeling

    OpenAIRE

    Fukuyama, Eiichi

    2003-01-01

    I propose a strategy to make a numerical computation applicable to the realistic modeling of an earthquake dynamic rupture process.To do this, it is important to introduce any observables into the simulation as initial and boundary conditions.As an initial condition, distribution of total stress before the dynamic rupture, and as boundary conditions, fault constitutive relation and geometry of the fault are necessary.The initial stress distribution would be obtained by both in-situ measuremen...

  4. Dirac Hartree-Fock for Finite Nuclei Employing realistic Forces

    OpenAIRE

    Müther, R. Fritz H.; Machleidt, R.

    1993-01-01

    We discuss two different approximation schemes for the self-consistent solution of the {\\it relativistic} Brueckner-Hartree-Fock equation for finite nuclei. In the first scheme, the Dirac effects are deduced from corresponding nuclear matter calculations, whereas in the second approach the local-density approximation is used to account for the effects of correlations. The results obtained by the two methods are very similar. Employing a realistic one-boson-exchange potential (Bonn~A), the pre...

  5. Emulating Realistic Bidirectional Spatial Channels for MIMO OTA Testing

    DEFF Research Database (Denmark)

    Fan, Wei; Kyösti, Pekka; Nielsen, Jesper Ødum;

    2015-01-01

    downlink channel models, whereas uplink channel is often modeled as free space line-of-sight channel without fading. Modeling realistic bidirectional (i.e., both uplink and downlink) propagation environments is essential to evaluate any bidirectional communication systems. There have been works stressing...... configurations) in the uplink and downlink. The simulation results are further supported by measurements in a practical MPAC setup. The proposed algorithm is shown to be a valid method to emulate bidirectional spatial channel models....

  6. Dynamics of the morphogenetic social enterprise: a critical realist perspective

    OpenAIRE

    Lucas, Iain

    2016-01-01

    The overall aim of this research is to generate critical insights into strategic decisions made by social actors in the process of developing and managing a SE (social enterprise) that facilitate social change. This focus covered two areas of influence the agency of the social actor and the structures that surround a SE development. Embedded in a critical realist paradigm, an emancipatory stance is taken to SE, which recognises this phenomenon as having dynamic and emergent properties. The cr...

  7. 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

  8. 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.

  9. Near-realistic mobile exergames with wireless wearable sensors.

    Science.gov (United States)

    Mortazavi, Bobak; Nyamathi, Suneil; Lee, Sunghoon Ivan; Wilkerson, Thomas; Ghasemzadeh, Hassan; Sarrafzadeh, Majid

    2014-03-01

    Exergaming is expanding as an option for sedentary behavior in childhood/adult obesity and for extra exercise for gamers. This paper presents the development process for a mobile active sports exergame with near-realistic motions through the usage of body-wearable sensors. The process begins by collecting a dataset specifically targeted to mapping real-world activities directly to the games, then, developing the recognition system in a fashion to produce an enjoyable game. The classification algorithm in this paper has precision and recall of 77% and 77% respectively, compared with 40% and 19% precision and recall on current activity monitoring algorithms intended for general daily living activities. Aside from classification, the user experience must be strong enough to be a successful system for adoption. Indeed, fast and intense activities as well as competitive, multiplayer environments make for a successful, enjoyable exergame. This enjoyment is evaluated through a 30 person user study. Multiple aspects of the exergaming user experience trials have been merged into a comprehensive survey, called ExerSurvey. All but one user thought the motions in the game were realistic and difficult to cheat. Ultimately, a game with near-realistic motions was shown to be an enjoyable, active video exergame for any environment. PMID:24608050

  10. 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.

  11. 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.

  12. Realistic prediction of solid pharmaceutical oxidation products by using a novel forced oxidation system.

    Science.gov (United States)

    Ueyama, Eiji; Tamura, Kousuke; Mizukawa, Kousei; Kano, Kenji

    2014-04-01

    This study investigated a novel solid-state-based forced oxidation system to enable a realistic prediction of pharmaceutical product oxidation, a key consideration in drug development and manufacture. Polysorbate 80 and ferric(III) acetylacetonate were used as an organic hydroperoxide source and a transition metal catalyst, respectively. Homogeneous solutions of target compounds and these reagents were prepared in a mixed organic solvent. The organic solvent was removed rapidly under reduced pressure, and the oxidation of the resulting dried solid was investigated. Analysis of the oxidation products generated in test compounds by this proposed forced oxidation system using HPLC showed a high similarity with those generated during more prolonged naturalistic drug oxidation. The proposed system provided a better predictive performance in prediction of realistic oxidative degradants of the drugs tested than did other established methods. Another advantage of this system was that the generation of undesired products of hydrolysis, solvolysis, and thermolysis was prevented because efficient oxidation was achieved under mild conditions. The results of this study suggest that this system is suitable for a realistic prediction of oxidative degradation of solid pharmaceuticals. PMID:24497072

  13. A generic framework to simulate realistic lung, liver and renal pathologies in CT imaging

    International Nuclear Information System (INIS)

    Realistic three-dimensional (3D) mathematical models of subtle lesions are essential for many computed tomography (CT) studies focused on performance evaluation and optimization. In this paper, we develop a generic mathematical framework that describes the 3D size, shape, contrast, and contrast-profile characteristics of a lesion, as well as a method to create lesion models based on CT data of real lesions. Further, we implemented a technique to insert the lesion models into CT images in order to create hybrid CT datasets. This framework was used to create a library of realistic lesion models and corresponding hybrid CT images. The goodness of fit of the models was assessed using the coefficient of determination (R2) and the visual appearance of the hybrid images was assessed with an observer study using images of both real and simulated lesions and receiver operator characteristic (ROC) analysis. The average R2 of the lesion models was 0.80, implying that the models provide a good fit to real lesion data. The area under the ROC curve was 0.55, implying that the observers could not readily distinguish between real and simulated lesions. Therefore, we conclude that the lesion-modeling framework presented in this paper can be used to create realistic lesion models and hybrid CT images. These models could be instrumental in performance evaluation and optimization of novel CT systems. (paper)

  14. 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. PMID:25265163

  15. A virtual auditory environment for investigating the auditory signal processing of realistic sounds

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel

    A loudspeaker-based virtual auditory environment (VAE) has been developed to provide a realistic versatile research environment for investigating the auditory signal processing in real environments, i.e., considering multiple sound sources and room reverberation. The VAE allows a full control of...... the acoustic scenario in order to systematically study the auditory processing of reverberant sounds. It is based on the ODEON software, which is state-of-the-art software for room acoustic simulations developed at Acoustic Technology, DTU. First, a MATLAB interface to the ODEON software has been...

  16. Meteorological impact of realistic Terra Nova Bay polynyas.

    Science.gov (United States)

    Morelli, Sandra

    2010-05-01

    The energy exchange between the ocean and the atmosphere in the Antarctic marginal sea ice zone is influenced by the extent of sea-ice cover. In areas of open water, a direct contact is established and intense energy exchanges occur, due to the large difference of temperature between the water and the air above it. This implies that the polynyas are areas where the ocean exchanges energy with the atmosphere and as a result they have an effect on the polar meteorology/climate. The work presented here concerns real polynya events in the region of Terra Nova Bay (TNB), Antarctica, where a recurring coastal polynya occurs nearby the Italian Antarctic Base. The aim is the study of the impact of polynyas on the atmosphere by three-dimensional numerical simulations. The ETA model (Mesinger et al., 2006) was used and ECMWF and NCEP data provided the initial and boundary conditions. The model had already been successfully used in the Antarctic area (Casini and Morelli, 2007) A polynya of realistic size (as observed by satellite image) was included in the initial conditions for the simulations and a study of the air circulation during the events is found in Morelli et al. (2007), Morelli and Casini (2008), Morelli et al. (2009). The Eta Model reproduced the evolution of upper and mod-level conditions in good agreement with AVHRR observations (Morelli, 2008, Morelli and Parmiggiani, 2009). Also, the simulated 10 m wind was well correlated with the observed extension of the polynya. In order to isolate the effect of the presence of the open water area on the structure of the atmospheric boundary layer and on the atmospheric circulation, further simulations were performed without the presence of the polynya, i.e. with its extent covered with sea ice. The numerical simulations show that the polynyas act to increase the speed of the air above them and generate strong heat fluxes that warm the air. The effects are found over and downwind the sea ice free area. Results from the Eta

  17. Towards dense, realistic granular media in 2D

    International Nuclear Information System (INIS)

    The development of an applicable theory for granular matter—with both qualitative and quantitative value—is a challenging prospect, given the multitude of states, phases and (industrial) situations it has to cover. Given the general balance equations for mass, momentum and energy, the limiting case of dilute and almost elastic granular gases, where kinetic theory works perfectly well, is the starting point. In most systems, low density co-exists with very high density, where the latter is an open problem for kinetic theory. Furthermore, many additional nonlinear phenomena and material properties are important in realistic granular media, involving, e.g.: 1. multi-particle interactions and elasticity; 2. strong dissipation,; 3. friction,; 4. long-range forces and wet contacts,; 5. wide particle size distributions and; 6. various particle shapes. Note that, while some of these issues are more relevant for high density, others are important for both low and high densities; some of them can be dealt with by means of kinetic theory, some cannot. This paper is a review of recent progress towards more realistic models for dense granular media in 2D, even though most of the observations, conclusions and corrections given are qualitatively true also in 3D. Starting from an elastic, frictionless and monodisperse hard sphere gas, the (continuum) balance equations of mass, momentum and energy are given. The equation of state, the (Navier–Stokes level) transport coefficients and the energy-density dissipation rate are considered. Several corrections are applied to those constitutive material laws—one by one—in order to account for the realistic physical effects and properties listed above. (invited article)

  18. 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.

  19. 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.

  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. 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.

  2. 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

  3. Hand effect on head specific absorption rate (SAR) exposed by two realistic phone models

    International Nuclear Information System (INIS)

    There have been some reports about possible effect of the hand presence on the head SAR if hand phantom is included in the measurements of the head SAR compliance assessment procedure. The objective of this computational study was to examine the reported effect by using realistic head models and realistic CAD based phone models. A commercially available FDTD based EM solver was used to carry out the computational work. Based on the results of this study considering the SAR values without hand phantom as reference, following conclusions can be made: 1. In general presence of the hand lead to significantly less conservative SAR values in the head for large majority of cases 2. For lower band GSM frequencies the presence of the hand decreases the head SAR up to ∼70%. 3. For the upper band GSM frequencies the presence of the hand decreases the head SAR up to ∼55%. Based on the results of this study the present SAR compliance protocol where hand phantom is not included leads to more conservative head SAR results compared to the cases where hand is included.

  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. A virtual auditory environment for investigating the auditory signal processing of realistic sounds

    DEFF Research Database (Denmark)

    Favrot, Sylvain Emmanuel; Buchholz, Jörg

    2008-01-01

    reverberation. The environment is based on the ODEON room acoustic simulation software to render the acoustical scene. ODEON outputs are processed using a combination of different order Ambisonic techniques to calculate multichannel room impulse responses (mRIR). Auralization is then obtained by the convolution....... Throughout the VAE development, special care was taken in order to achieve a realistic auditory percept and to avoid “artifacts” such as unnatural coloration. The performance of the VAE has been evaluated and optimized on a 29 loudspeaker setup using both objective and subjective measurement techniques....

  6. Electron percolation in realistic models of carbon nanotube networks

    Energy Technology Data Exchange (ETDEWEB)

    Simoneau, Louis-Philippe, E-mail: louis-philippe.simoneau@polymtl.ca; Villeneuve, Jérémie, E-mail: jeremie.villeneuve@polymtl.ca; Rochefort, Alain, E-mail: alain.rochefort@polymtl.ca [Département de génie physique and Regroupement québécois sur les matériaux de pointe (RQMP), École Polytechnique de Montréal, Montréal, Québec H3C 3A7 (Canada)

    2015-09-28

    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.

  7. Toward the classification of the realistic free fermionic models

    Energy Technology Data Exchange (ETDEWEB)

    Faraggi, A.E.

    1997-08-01

    The realistic free fermionic models have had remarkable success in providing plausible explanations for various properties of the Standard Model which include the natural appearance of three generations, the explanation of the heavy top quark mass and the qualitative structure of the fermion mass spectrum in general, the stability of the proton and more. These intriguing achievements makes evident the need to understand the general space of these models. While the number of possibilities is large, general patterns can be extracted. In this paper the author presents a detailed discussion on the construction of the realistic free fermionic models with the aim of providing some insight into the basic structures and building blocks that enter the construction. The role of free phases in the determination of the phenomenology of the models is discussed in detail. The author discusses the connection between the free phases and mirror symmetry in (2,2) models and the corresponding symmetries in the case of (2,0) models. The importance of the free phases in determining the effective low energy phenomenology is illustrated in several examples. The classification of the models in terms of boundary condition selection rules, real world-sheet fermion pairings, exotic matter states and the hidden sector is discussed.

  8. 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.

  9. Radiation-Spray Coupling for Realistic Flow Configurations

    Science.gov (United States)

    El-Asrag, Hossam; Iannetti, Anthony C.

    2011-01-01

    Three Large Eddy Simulations (LES) for a lean-direct injection (LDI) combustor are performed and compared. In addition to the cold flow simulation, the effect of radiation coupling with the multi-physics reactive flow is analyzed. The flame let progress variable approach is used as a subgrid combustion model combined with a stochastic subgrid model for spray atomization and an optically thin radiation model. For accurate chemistry modeling, a detailed Jet-A surrogate mechanism is utilized. To achieve realistic inflow, a simple recycling technique is performed at the inflow section upstream of the swirler. Good comparison is shown with the experimental data mean and root mean square profiles. The effect of combustion is found to change the shape and size of the central recirculation zone. Radiation is found to change the spray dynamics and atomization by changing the heat release distribution and the local temperature values impacting the evaporation process. The simulation with radiation modeling shows wider range of droplet size distribution by altering the evaporation rate. The current study proves the importance of radiation modeling for accurate prediction in realistic spray combustion configurations, even for low pressure systems.

  10. 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.

  11. Electron percolation in realistic models of carbon nanotube networks

    International Nuclear Information System (INIS)

    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

  12. 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

  13. Measurement of time delays in gated radiotherapy for realistic respiratory motions

    Energy Technology Data Exchange (ETDEWEB)

    Chugh, Brige P.; Quirk, Sarah; Conroy, Leigh; Smith, Wendy L., E-mail: Wendy.Smith@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada)

    2014-09-15

    Purpose: Gated radiotherapy is used to reduce internal motion margins, escalate target dose, and limit normal tissue dose; however, its temporal accuracy is limited. Beam-on and beam-off time delays can lead to treatment inefficiencies and/or geographic misses; therefore, AAPM Task Group 142 recommends verifying the temporal accuracy of gating systems. Many groups use sinusoidal phantom motion for this, under the tacit assumption that use of sinusoidal motion for determining time delays produces negligible error. The authors test this assumption by measuring gating time delays for several realistic motion shapes with increasing degrees of irregularity. Methods: Time delays were measured on a linear accelerator with a real-time position management system (Varian TrueBeam with RPM system version 1.7.5) for seven motion shapes: regular sinusoidal; regular realistic-shape; large (40%) and small (10%) variations in amplitude; large (40%) variations in period; small (10%) variations in both amplitude and period; and baseline drift (30%). Film streaks of radiation exposure were generated for each motion shape using a programmable motion phantom. Beam-on and beam-off time delays were determined from the difference between the expected and observed streak length. Results: For the system investigated, all sine, regular realistic-shape, and slightly irregular amplitude variation motions had beam-off and beam-on time delays within the AAPM recommended limit of less than 100 ms. In phase-based gating, even small variations in period resulted in some time delays greater than 100 ms. Considerable time delays over 1 s were observed with highly irregular motion. Conclusions: Sinusoidal motion shapes can be considered a reasonable approximation to the more complex and slightly irregular shapes of realistic motion. When using phase-based gating with predictive filters even small variations in period can result in time delays over 100 ms. Clinical use of these systems for patients

  14. 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...

  15. 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.

  16. Light Higgsino Dark Matter in a Realistic String CMSSM

    CERN Document Server

    Mayes, Van E

    2014-01-01

    When supersymmetry breaking is dominated by the complex structure moduli and the universal dilaton, a subset of the supersymmetry parameter space in a realistic MSSM constructed from intersecting/magnetized D-branes is equivalent to the mSUGRA/CMSSM parameter space with the trilinear term fixed to be minus the gaugino mass, A_0=-m_{1/2}. More generally, the scalar mass-squared terms for sfermions are split about the Higgs mass-squared terms, m_{Q_L,L_L}^2=m_H^2 - \\Delta m^2$ and m_{Q_R,L_R}^2=m_H^2 + \\Delta m^2, for generic values of the Kahler moduli. The hyberbolic branch/focus point (HB/FP) regions of this parameter space are present for both \\Delta m^2 = 0 and \\Delta m^2 \

  17. Ab initio H2O in realistic hydrophilic confinement.

    Science.gov (United States)

    Allolio, Christoph; Klameth, Felix; Vogel, Michael; Sebastiani, Daniel

    2014-12-15

    A protocol for the ab initio construction of a realistic cylindrical pore in amorphous silica, serving as a geometric nanoscale confinement for liquids and solutions, is presented. Upon filling the pore with liquid water at different densities, the structure and dynamics of the liquid inside the confinement can be characterized. At high density, the pore introduces long-range oscillations into the water density profile, which makes the water structure unlike that of the bulk across the entire pore. The tetrahedral structure of water is also affected up to the second solvation shell of the pore wall. Furthermore, the effects of the confinement on hydrogen bonding and diffusion, resulting in a weakening and distortion of the water structure at the pore walls and a slowdown in diffusion, are characterized. PMID:25208765

  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. 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...

  20. Mode engineering for realistic quantum-enhanced interferometry.

    Science.gov (United States)

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

    2016-01-01

    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. PMID:27125782

  1. Resolving conflict realistically in today's health care environment.

    Science.gov (United States)

    Smith, S B; Tutor, R S; Phillips, M L

    2001-11-01

    Conflict is a natural part of human interaction, and when properly addressed, results in improved interpersonal relationships and positive organizational culture. Unchecked conflict may escalate to verbal and physical violence. Conflict that is unresolved creates barriers for people, teams, organizational growth, and productivity, leading to cultural disintegration within the establishment. By relying on interdependence and professional collaboration, all parties involved grow and, in turn, benefit the organization and population served. When used in a constructive manner, conflict resolution can help all parties involved see the whole picture, thus allowing freedom for growth and change. Conflict resolution is accomplished best when emotions are controlled before entering into negotiation. Positive confrontation, problem solving, and negotiation are processes used to realistically resolve conflict. Everyone walks away a winner when conflict is resolved in a positive, professional manner (Stone, 1999). PMID:11725427

  2. Ring Current Modeling in a Realistic Magnetic Field Configuration

    Science.gov (United States)

    Fok, M.-C.; Moore, T. E.

    1997-01-01

    A 3-dimensional kinetic model has been developed to study the dynamics of the storm time ring current in a dipole magnetic field. In this paper, the ring current model is extended to include a realistic, time-varying magnetic field model. The magnetic field is expressed as the cross product of the gradients of two Euler potentials and the bounce-averaged particle drifts are calculated in the Euler potential coordinates. A dipolarization event is modeled by collapsing a tail-like magnetosphere to a dipole-like configuration. Our model is able to simulate the sudden enhancements in the ring current ion fluxes and the corresponding ionospheric precipitation during the substorm expansion.

  3. 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.

  4. Design for and efficient dynamic climate model with realistic geography

    Science.gov (United States)

    Suarez, M. J.; Abeles, J.

    1984-01-01

    The long term climate sensitivity which include realistic atmospheric dynamics are severely restricted by the expense of integrating atmospheric general circulation models are discussed. Taking as an example models used at GSFC for this dynamic model is an alternative which is of much lower horizontal or vertical resolution. The model of Heid and Suarez uses only two levels in the vertical and, although it has conventional grid resolution in the meridional direction, horizontal resolution is reduced by keeping only a few degrees of freedom in the zonal wavenumber spectrum. Without zonally asymmetric forcing this model simulates a day in roughly 1/2 second on a CRAY. The model under discussion is a fully finite differenced, zonally asymmetric version of the Heid-Suarez model. It is anticipated that speeds can be obtained a few seconds a day roughly 50 times faster than moderate resolution, multilayer GCM's.

  5. Generating realistic environments for cyber operations development, testing, and training

    Science.gov (United States)

    Berk, Vincent H.; Gregorio-de Souza, Ian; Murphy, John P.

    2012-06-01

    Training eective cyber operatives requires realistic network environments that incorporate the structural and social complexities representative of the real world. Network trac generators facilitate repeatable experiments for the development, training and testing of cyber operations. However, current network trac generators, ranging from simple load testers to complex frameworks, fail to capture the realism inherent in actual environments. In order to improve the realism of network trac generated by these systems, it is necessary to quantitatively measure the level of realism in generated trac with respect to the environment being mimicked. We categorize realism measures into statistical, content, and behavioral measurements, and propose various metrics that can be applied at each level to indicate how eectively the generated trac mimics the real world.

  6. 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.

  7. 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.

  8. Bosonic structure of realistic SO(10) SUSY cosmic strings

    CERN Document Server

    Allys, E

    2015-01-01

    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 SSB scheme in parallel with the inflationary process. We also write the explicit tensor formulation of its scalar sector, focusing on the sub-representations 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.

  9. 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.

  10. Capturing and reproducing realistic acoustic scenes for hearing research

    DEFF Research Database (Denmark)

    Marschall, Marton; Buchholz, Jörg

    Accurate spatial audio recordings are important for a range of applications, from the creation of realistic virtual sound environments to the evaluation of communication devices, such as hearing instruments and mobile phones. Spherical microphone arrays are particularly well-suited for capturing......-order ambisonics (HOA) with additional, horizontally oriented spherical harmonic functions of higher orders. Simulations of a MOA array, with a higher density of microphones near the equator, and an array with a nearly uniform distribution of microphones were compared in terms of spatial resolution and robustness...... at mid to high frequencies as the need for regularization limits spatial directivity at lower frequencies. Finally, the MOA array was also evaluated in terms of sound field reconstruction error in a head-sized region. Results provided a physical validation of the functioning of the MOA microphone array...

  11. Adaptive Dynamics of Realistic Small-World Networks

    CERN Document Server

    Mogren, Olof; Verendel, Vilhelm; Dubhashi, Devdatt

    2008-01-01

    Continuing in the steps of Jon Kleinberg's and others celebrated work on decentralized search in small-world networks, we conduct an experimental analysis of a dynamic algorithm that produces small-world networks. We find that the algorithm adapts robustly to a wide variety of situations in realistic geographic networks with synthetic test data and with real world data, even when vertices are uneven and non-homogeneously distributed. We investigate the same algorithm in the case where some vertices are more popular destinations for searches than others, for example obeying power-laws. We find that the algorithm adapts and adjusts the networks according to the distributions, leading to improved performance. The ability of the dynamic process to adapt and create small worlds in such diverse settings suggests a possible mechanism by which such networks appear in nature.

  12. 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.

  13. A realistic model of the semileptonic decays of beauty

    International Nuclear Information System (INIS)

    A realistic calculation of the semileptonic decays of B-mesons, which depends in an essential manner on the Kobayashi-Maskawa matrix elements Vsub(b->c) and Vsub(b->u) only, is presented. A very good fit to the experimental lepton spectrum is obtained for vertical strokeVsub(b->u)/Vsub(b->c)vertical stroke2 = 0.10+-0.06, and from the world average for the B-lifetime (tausub(B) = 1.04+-0.15 ps), Vsub(b->c) = (5.9+-0.4)x10-2 and Vsub(b->u) = (1.9+-0.5)x10-2 are derived. (orig.)

  14. 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...

  15. Stereoscopic virtual realistic surgical simulation in intracranial aneurysms

    Directory of Open Access Journals (Sweden)

    Hiromichi Nakabayashi

    2012-01-01

    Full Text Available Background: Three-dimensional (3D-computed tomographic angiography (CTA has been widely used for surgical simulation of intracranial aneurysms. Stereo imaging technology is progressing rapidly in recent years and stereo imaging may make more realistic surgical simulation possible. Therefore, we aimed at the establishment of a technique for stereoscopic viewing of minute volume rendering images while pursuing a low cost. Materials and Methods: Between January 2009 and June 2011, 54 patients with ruptured intracranial aneurysms were enrolled in this study. CTA data was transferred to the workstation equipped with image-processing software, and multilayer fusion images were processed by neurosurgeons. Image data for stereoscopic viewing of multilayer fusion image from arbitrary directions were collected form rotational trajectories around an aneurysm and were output to MPEG file. Stereoscopic viewing using MPEG data was achieved by the freeware named Stereo Movie Maker. Stereo viewing method using QuickTime VR format was also tried. Results: Multilayer fusion image created from CTA data displayed clearly the anatomical information about not only the aneurysm but also the surrounding structures, such as parent artery, venous system, brain tissue, skull bone, and scalp. The quality of the resulting multilayer fusion image was suitable for surgical simulation with virtual reality. Virtual realistic surgical simulation became possible by the combination of minute multilayer fusion image and stereoscopic viewing by our method. Conclusions: Our method for stereo viewing of multilayer fusion images resulted in an improvement in the capability of diagnostic imaging and the image-guided support for neurosurgical procedures in intracranial aneurysm.

  16. Advances in production of realistic cracks to NDT development and qualification purposes of steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Virkkunen, I.; Kemppainen, M. [Truflaw Ltd., Espoo (Finland); Tchilian, J.-M. [AREVA Nuclear Power Plant Sector, Saskatoon, Saskatchewan (Canada); Martens, J. [AREVA NP Intercontrole (France)

    2009-07-01

    Realistic defects are needed for steam generator tube inspections when developing new NDT methods or assessing the performance and reliability of methods and procedures used. Furthermore, realistic defects give the most reliable results in assessing service-related reliability of steam generator tubes by, for example, burst or leak tests. It is crucial to have representative defects as the defect characteristics has marked effect on the results both in NDE, burst and leak tests. Representativeness should be to the actual service-induced defects, and the evaluation should be based on the essential defect characteristics. In this paper real world application cases are presented about crack production to steam generator tubes. Crack production technique used is based on controlled thermal fatigue process creating natural cracks. Such cracks have been produced in Alloy 690 and austenitic stainless steel steam generator tubes. These cracks have been used, for example, for advanced NDT qualification purposes of a new build nuclear power plant. Paper presents results of the destructive tests performed after validation tests of the crack manufacturing in the Alloy 690 and austenitic stainless steel. These results are shown for both of the materials with measured essential crack characteristics. In addition to metallographic analysis, the paper presents the results of performed NDT inspections for the Alloy 690. Results have been obtained with an advanced inspection technique developed and used for today's inspections of steam generator tubes in nuclear power plants. (author)

  17. Advanced Simulation of Coupled Earthquake and Tsunami Events (ASCETE) - Simulation Techniques for Realistic Tsunami Process Studies

    Science.gov (United States)

    Behrens, Joern; Bader, Michael; Breuer, Alexander N.; van Dinther, Ylona; Gabriel, Alice-A.; Galvez Barron, Percy E.; Rahnema, Kaveh; Vater, Stefan; Wollherr, Stephanie

    2015-04-01

    At the End of phase 1 of the ASCETE project a simulation framework for coupled physics-based rupture generation with tsunami propagation and inundation is available. Adaptive mesh tsunami propagation and inundation by discontinuous Galerkin Runge-Kutta methods allows for accurate and conservative inundation schemes. Combined with a tree-based refinement strategy to highly optimize the code for high-performance computing architectures, a modeling tool for high fidelity tsunami simulations has been constructed. Validation results demonstrate the capacity of the software. Rupture simulation is performed by an unstructured tetrahedral discontinuous Galerking ADER discretization, which allows for accurate representation of complex geometries. The implemented code was nominated for and was selected as a finalist for the Gordon Bell award in high-performance computing. Highly realistic rupture events can be simulated with this modeling tool. The coupling of rupture induced wave activity and displacement with hydrodynamic equations still poses a major problem due to diverging time and spatial scales. Some insight from the ASCETE set-up could be gained and the presentation will focus on the coupled behavior of the simulation system. Finally, an outlook to phase 2 of the ASCETE project will be given in which further development of detailed physical processes as well as near-realistic scenario computations are planned. ASCETE is funded by the Volkswagen Foundation.

  18. Low resolution brain electromagnetic tomography in a realistic geometry head model: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Ding Lei; Lai Yuan; He Bin [Department of Biomedical Engineering, University of Minnesota, 7-105 BSBE, 312 Church Street SE, Minneapolis, MN 55455 (United States)

    2005-01-07

    It is of importance to localize neural sources from scalp recorded EEG. Low resolution brain electromagnetic tomography (LORETA) has received considerable attention for localizing brain electrical sources. However, most such efforts have used spherical head models in representing the head volume conductor. Investigation of the performance of LORETA in a realistic geometry head model, as compared with the spherical model, will provide useful information guiding interpretation of data obtained by using the spherical head model. The performance of LORETA was evaluated by means of computer simulations. The boundary element method was used to solve the forward problem. A three-shell realistic geometry (RG) head model was constructed from MRI scans of a human subject. Dipole source configurations of a single dipole located at different regions of the brain with varying depth were used to assess the performance of LORETA in different regions of the brain. A three-sphere head model was also used to approximate the RG head model, and similar simulations performed, and results compared with the RG-LORETA with reference to the locations of the simulated sources. Multi-source localizations were discussed and examples given in the RG head model. Localization errors employing the spherical LORETA, with reference to the source locations within the realistic geometry head, were about 20-30 mm, for four brain regions evaluated: frontal, parietal, temporal and occipital regions. Localization errors employing the RG head model were about 10 mm over the same four brain regions. The present simulation results suggest that the use of the RG head model reduces the localization error of LORETA, and that the RG head model based LORETA is desirable if high localization accuracy is needed.

  19. 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.

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

    International Nuclear Information System (INIS)

    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

  1. Realistic methods for calculating the releases and consequences of a large LOCA

    International Nuclear Information System (INIS)

    This report describes a calculational route to predict realistic radiological consequences for a successfully terminated large-loss-of-coolant accident (LOCA) at a pressurized-water reactor (PWR). All steps in the calculational route are considered. For each one, a brief comment is made on the significant differences between the methods of calculation that were identified in the benchmark studies and recommendations are made for the methods and data for carrying out realistic calculations. These are based on the best supportable methods and data and the technical basis for each recommendation is given. Where the lack of well-validated methods or data means that the most realistic method that can be justified is considered to be very conservative, the need for further research is identified. The behaviour of inorganic iodine and the removal of aerosols from the atmosphere of the reactor building are identified as areas of particular importance. Where the retention of radioactivity is sensitive to design features, these are identified and, for the most importance features, the impact of different designs on the release of activity is indicated. The predictions of the proposed model are calculated for each stage and compared with the releases of activity predicted by the licensing methods that were used in the earlier benchmark studies. The conservative nature of the latter is confirmed. Methods and data are also presented for calculating the resulting doses to members of the public of the National Radiological Protection Boards as a result of work carried out by several national bodies in the UK. Other, equally acceptable, models are used in other countries of the Community and some examples are given

  2. Processing of the GALILEO fuel rod code model uncertainties within the AREVA LWR realistic thermal-mechanical analysis methodology

    International Nuclear Information System (INIS)

    The availability of reliable tools and associated methodology able to accurately predict the LWR fuel behavior in all conditions is of great importance for safe and economic fuel usage. For that purpose, AREVA has developed its new global fuel rod performance code GALILEO along with its associated realistic thermal-mechanical analysis methodology. This realistic methodology is based on a Monte Carlo type random sampling of all relevant input variables. After having outlined the AREVA realistic methodology, this paper will be focused on the GALILEO code benchmarking process, on its extended experimental database and on the GALILEO model uncertainties assessment. The propagation of these model uncertainties through the AREVA realistic methodology is also presented. This GALILEO model uncertainties processing is of the utmost importance for accurate fuel design margin evaluation as illustrated on some application examples. With the submittal of Topical Report GALILEO to the U.S. NRC in 2013, GALILEO and its methodology are on the way to be industrially used in a wide range of irradiation conditions. (authors)

  3. Simulation and assessment of realistic breast lesions using fractal growth models

    Science.gov (United States)

    Rashidnasab, A.; Elangovan, P.; Yip, M.; Diaz, O.; Dance, D. R.; Young, K. C.; Wells, K.

    2013-08-01

    A new method of generating realistic three dimensional simulated breast lesions known as diffusion limited aggregation (DLA) is presented, and compared with the random walk (RW) method. Both methods of lesion simulation utilize a physics-based method for inserting these simulated lesions into 2D clinical mammogram images that takes into account the polychromatic x-ray spectrum, local glandularity and scatter. DLA and RW masses were assessed for realism via a receiver operating characteristic (ROC) study with nine observers. The study comprised 150 images of which 50 were real pathology proven mammograms, 50 were normal mammograms with RW inserted masses and 50 were normal mammograms with DLA inserted masses. The average area under the ROC curve for the DLA method was 0.55 (95% confidence interval 0.51-0.59) compared to 0.60 (95% confidence interval 0.56-0.63) for the RW method. The observer study results suggest that the DLA method produced more realistic masses with more variability in shape compared to the RW method. DLA generated lesions can overcome the lack of complexity in structure and shape in many current methods of mass simulation.

  4. Effective shell-model hamiltonians from realistic nucleon–nucleon potentials within a perturbative approach

    International Nuclear Information System (INIS)

    This paper discusses the derivation of an effective shell-model hamiltonian starting from a realistic nucleon–nucleon potential by way of perturbation theory. More precisely, we present the state of the art of this approach when the starting point is the perturbative expansion of the Q-hat-box vertex function. Questions arising from diagrammatics, intermediate-states and order-by-order convergences, and their dependence on the chosen nucleon–nucleon potential, are discussed in detail, and the results of numerical applications for the p-shell model space starting from chiral next-to-next-to-next-to-leading order potentials are shown. Moreover, an alternative graphical method to derive the effective hamiltonian, based on the Z-hat-box vertex function recently introduced by Suzuki et al., is applied to the case of a non-degenerate (0+2)ħω model space. Finally, our shell-model results are compared with the exact ones obtained from no-core shell-model calculations. - Highlights: ► The derivation of nuclear realistic shell-model effective hamiltonians is studied. ► Perturbation theory. ► Diagrammatics, intermediate-states and order-by-order convergences are investigated. ► Shell-model calculations in degenerate and non-degenerate model spaces are presented. ► Shell-model results are compared with the exact ones.

  5. 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.

  6. 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.

  7. A full potential flow analysis with realistic wake influence for helicopter rotor airload prediction

    Science.gov (United States)

    Egolf, T. Alan; Sparks, S. Patrick

    1987-01-01

    A 3-D, quasi-steady, full potential flow solver was adapted to include realistic wake influence for the aerodynamic analysis of helicopter rotors. The method is based on a finite difference solution of the full potential equation, using an inner and outer domain procedure for the blade flowfield to accommodate wake effects. The nonlinear flow is computed in the inner domain region using a finite difference solution method. The wake is modeled by a vortex lattice using prescribed geometry techniques to allow for the inclusion of realistic rotor wakes. The key feature of the analysis is that vortices contained within the finite difference mesh (inner domain) were treated with a vortex embedding technique while the influence of the remaining portion of the wake (in the outer domain) is impressed as a boundary condition on the outer surface of the finite difference mesh. The solution procedure couples the wake influence with the inner domain solution in a consistent and efficient solution process. The method has been applied to both hover and forward flight conditions. Correlation with subsonic and transonic hover airload data is shown which demonstrates the merits of the approach.

  8. Effective realistic interactions for low momentum Hilbert spaces

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Dennis

    2012-12-13

    Realistic nucleon-nucleon potentials are an essential ingredient of modern microscopic many-body calculations. These potentials can be represented in two different ways: operator representation or matrix element representation. In operator representation the potential is represented by a set of quantum mechanical operators while in matrix element representation it is defined by the matrix elements in a given basis. Many modern potentials are constructed directly in matrix element representation. While the matrix element representation can be calculated from the operator representation, the determination of the operator representation from the matrix elements is more difficult. Some methods to solve the nuclear many-body problem, such as Fermionic Molecular Dynamics (FMD) or the Green's Function Monte Carlo (GFMC) method, however require explicitly the operator representation of the potential, as they do not work in a fixed many-body basis. It is therefore desirable to derive an operator representation also for the interactions given by matrix elements. In this work a method is presented which allows the derivation of an approximate operator representation starting from the momentum space partial wave matrix elements of the interaction. For that purpose an ansatz for the operator representation is chosen. The parameters in the ansatz are determined by a fit to the partial wave matrix elements. Since a perfect reproduction of the matrix elements in general cannot be achieved with a finite number of operators and the quality of the results depends on the choice of the ansatz, the obtained operator representation is tested in nuclear many-body calculations and the results are compared with those from the initial interaction matrix elements. For the calculation of the nucleon-nucleon scattering phase shifts and the deuteron properties a computer code written within this work is used. For larger nuclei the No Core Shell Model (NCSM) and FMD are applied. The

  9. Information quantity and quality affect the realistic accuracy of personality judgment.

    Science.gov (United States)

    Letzring, Tera D; Wells, Shannon M; Funder, David C

    2006-07-01

    Triads of unacquainted college students interacted in 1 of 5 experimental conditions that manipulated information quantity (amount of information) and information quality (relevance of information to personality), and they then made judgments of each others' personalities. To determine accuracy, the authors compared the ratings of each judge to a broad-based accuracy criterion composed of personality ratings from 3 types of knowledgeable informants (the self, real-life acquaintances, and clinician-interviewers). Results supported the hypothesis that information quantity and quality would be positively related to objective knowledge about the targets and realistic accuracy. Interjudge consensus and self-other agreement followed a similar pattern. These findings are consistent with expectations based on models of the process of accurate judgment (D. C. Funder, 1995, 1999) and consensus (D. A. Kenny, 1994). PMID:16834483

  10. Toward Affordable, Theory-and-Simulation-Inspired, Models for Realistic Wind Turbine Aerodynamics and Noise

    Science.gov (United States)

    Ladeinde, Foluso; Alabi, Ken; Li, Wenhai

    2015-11-01

    The problem of generating design data for the operation of a farm of wind turbines for clean energy production is quite complicated, if properly done. Potential flow theories provide some models, but these are not suitable for the massive aerodynamic separation and turbulence that characterize many realistic wind turbine applications. Procedures, such as computational fluid dynamics (CFD), which can potentially resolve some of the accuracy problems with the purely theoretical approach, are quite expensive to use, and often prohibit real-time design and control. In our work, we seek affordable and acceptably-accurate models derived from the foregoing approaches. The simulation used in our study is based on high-fidelity CFD, meaning that we use high-order (compact-scheme based), mostly large-eddy simulation methods, with due regards for the proper treatment of the stochastic inflow turbulence data. Progress on the project described herein will be presented.

  11. Modeling the Earth's magnetospheric magnetic field confined within a realistic magnetopause

    Science.gov (United States)

    Tsyganenko, N. A.

    1995-01-01

    Empirical data-based models of the magnetosphereic magnetic field have been widely used during recent years. However, the existing models (Tsyganenko, 1987, 1989a) have three serious deficiencies: (1) an unstable de facto magnetopause, (2) a crude parametrization by the K(sub p) index, and (3) inaccuracies in the equatorial magnetotail B(sub z) values. This paper describes a new approach to the problem; the essential new features are (1) a realistic shape and size of the magnetopause, based on fits to a large number of observed crossing (allowing a parametrization by the solar wind pressure), (2) fully controlled shielding of the magnetic field produced by all magnetospheric current systems, (3) new flexible representations for the tail and ring currents, and (4) a new directional criterion for fitting the model field to spacecraft data, providing improved accuracy for field line mapping. Results are presented from initial efforts to create models assembled from these modules and calibrated against spacecraft data sets.

  12. 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.

  13. Realistic Modeling of Spontaneous Flow Eruptions in the Quiet Sun

    Science.gov (United States)

    Kitiashvili, Irina; Yoon, Seokkwan S

    2014-06-01

    Ground and space observations reveal that the solar surface is covered by high-speed jets transporting mass and energy into the solar corona and feeding the solar wind. The origin and driving forces of the observed eruptions are still unknown. Using realistic numerical simulations we find that small-scale plasma eruptions can be produced by ubiquitous magnetized vortex tubes generated in the Sun's turbulent convection. The vortex tubes (resembling tornadoes) penetrate into the solar atmosphere, capture and strengthen the background magnetic field, and push surrounding material up, generating impulses of Alfven waves and shocks. Our simulations reveal complicated high-speed flows, thermodynamic, and magnetic structures in the erupting vortex tubes. We find that the eruptions are initiated in the subsurface layers, and initially are driven by high-pressure gradients in the subphotosphere and photosphere, and are accelerated by the Lorentz force in the higher atmospheric layers. The eruptions are often quasi-periodic with a characteristic period of 2-5 min. These vortex eruptions have a complicated flow helical pattern, with predominantly downward flows in the vortex tube cores and upward flows in their surroundings. For comparison with observations we calculate full Stokes profiles in different wavelength for different space and ground instruments, such as HMI/SDO, Hinode, NST/BBSO, IMaX/Sunrise. In particular, we find that the observed eruption events are not always associated with strong magnetic field concentrations, and that strong field patches can be a source of several simultaneous eruptions.

  14. 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.

  15. 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)

  16. 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.

  17. 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...

  18. 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.)

  19. 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 ...

  20. OFDM versus Single Carrier: A Realistic Multi-Antenna Comparison

    Directory of Open Access Journals (Sweden)

    Jan Tubbax

    2004-08-01

    Full Text Available There is an ongoing discussion in the broadband wireless world about the respective benefits of orthogonal frequency division multiplexing (OFDM and single carrier with frequency domain equalization (SC-FD. SC-FD allows for more relaxed front-end requirements, of which the power amplifier efficiency is very important for battery-driven terminals. OFDM, on the other hand, can yield improved BER performance at low complexity. Both schemes have extensions to multiple antennas to enhance the spectral efficiency and/or the link reliability. Moreover, both schemes have nonlinear versions using decision feedback equalization (DFE to further improve performance of the linear equalizers. In this paper, we compare these high-performance OFDM and SC-FD schemes using multiple antennas and DFE, while also accounting for the power amplifier efficiency. To make a realistic comparison, we also consider most important digital imperfections, such as channel and noise estimation, transmit and receive filtering, clipping and quantization, as well as link layer impact. Our analysis shows that for frequency-selective channels the relative performance impact of the power amplifier is negligible compared to the frequency diversity impact. The higher frequency diversity exploitation of SC-FD allows it to outperform OFDM in most cases. Therefore, SC-FD is a suitable candidate for broadband wireless communication.

  1. Time-distance helioseismology of two realistic sunspot simulations

    International Nuclear Information System (INIS)

    Linear time-distance helioseismic inversions are carried out using several filtering schemes to determine vector flow velocities within two ∼1002 Mm2 × 20 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 (∼0.5-0.8) 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 to the fact that we are unable to accurately measure travel times near strong magnetic features. In many cases the velocity amplitudes from the inversions underestimate those of the simulations by up to 50%, possibly indicating nonlinearity of the forward problem. In every case, we find that our inversions are unable to recover the vertical flow structure of the simulations at any depth.

  2. Conceptual priming for realistic auditory scenes and for auditory words.

    Science.gov (United States)

    Frey, Aline; Aramaki, Mitsuko; Besson, Mireille

    2014-02-01

    Two experiments were conducted using both behavioral and Event-Related brain Potentials methods to examine conceptual priming effects for realistic auditory scenes and for auditory words. Prime and target sounds were presented in four stimulus combinations: Sound-Sound, Word-Sound, Sound-Word and Word-Word. Within each combination, targets were conceptually related to the prime, unrelated or ambiguous. In Experiment 1, participants were asked to judge whether the primes and targets fit together (explicit task) and in Experiment 2 they had to decide whether the target was typical or ambiguous (implicit task). In both experiments and in the four stimulus combinations, reaction times and/or error rates were longer/higher and the N400 component was larger to ambiguous targets than to conceptually related targets, thereby pointing to a common conceptual system for processing auditory scenes and linguistic stimuli in both explicit and implicit tasks. However, fine-grained analyses also revealed some differences between experiments and conditions in scalp topography and duration of the priming effects possibly reflecting differences in the integration of perceptual and cognitive attributes of linguistic and nonlinguistic sounds. These results have clear implications for the building-up of virtual environments that need to convey meaning without words. PMID:24378910

  3. Realistic PET Monte Carlo Simulation With Pixelated Block Detectors, Light Sharing, Random Coincidences and Dead-Time Modeling

    OpenAIRE

    Guérin, Bastein; Fakhri, Georges El

    2008-01-01

    We have developed and validated a realistic simulation of random coincidences, pixelated block detectors, light sharing among crystal elements and dead-time in 2D and 3D positron emission tomography (PET) imaging based on the SimSET Monte Carlo simulation software. Our simulation was validated by comparison to a Monte Carlo transport code widely used for PET modeling, GATE, and to measurements made on a PET scanner.

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

    OpenAIRE

    Fatih Uenal

    2016-01-01

    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 Thr...

  5. The relative greenhouse gas impacts of realistic dietary choices

    International Nuclear Information System (INIS)

    The greenhouse gas (GHG) emissions embodied in 61 different categories of food are used, with information on the diet of different groups of the population (omnivorous, vegetarian and vegan), to calculate the embodied GHG emissions in different dietary scenarios. We calculate that the embodied GHG content of the current UK food supply is 7.4 kg CO2e person−1 day−1, or 2.7 t CO2e person−1 y−1. This gives total food-related GHG emissions of 167 Mt CO2e (1 Mt=106 metric tonnes; CO2e being the mass of CO2 that would have the same global warming potential, when measured over 100 years, as a given mixture of greenhouse gases) for the entire UK population in 2009. This is 27% of total direct GHG emissions in the UK, or 19% of total GHG emissions from the UK, including those embodied in goods produced abroad. We calculate that potential GHG savings of 22% and 26% can be made by changing from the current UK-average diet to a vegetarian or vegan diet, respectively. Taking the average GHG saving from six vegetarian or vegan dietary scenarios compared with the current UK-average diet gives a potential national GHG saving of 40 Mt CO2e y−1. This is equivalent to a 50% reduction in current exhaust pipe emissions from the entire UK passenger car fleet. Hence realistic choices about diet can make substantial differences to embodied GHG emissions. - Highlights: ► We calculate the greenhouse gas emissions embodied in different diets. ► The embodied GHG content of the current UK food supply is 7.4 kg CO2e person−1 day−1. ► Changing to a vegetarian or vegan diet reduces GHG emissions by 22–26%. ► Changing to a vegetarian or vegan diet would reduce UK GHG emissions by 40 Mt CO2e y−1.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Effect on Hyalella azteca after pulse exposure to environmentally realistic concentrations of permethrin

    DEFF Research Database (Denmark)

    Pedersen, Signe; Palmqvist, Annemette; Forbes, Valery E.

    Exposure of non-target aquatic organisms to pesticides is likely to occur in short pulses following periods of drain flow, surface run-off or spray drift. However, standard aquatic toxicity tests are primarily based on continuous and maintained exposure periods of 24 to 96 hours for acute effect...... 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...

  11. 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.

  12. 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.

  13. Methodology and input availability parameters for calculating OpEx and CapEx costs for realistic network scenarios

    Science.gov (United States)

    Verbrugge, S.; Colle, D.; Pickavet, M.; Demeester, P.; Pasqualini, S.; Iselt, A.; Kirstädter, A.; Hülsermann, R.; Westphal, F.-J.; Jäger, M.

    2006-06-01

    The availability requirements for today's networks are very high. Higher availability often comes with a higher cost. We describe several steps required for estimating the costs of realistic network scenarios. Capital expenditures (CapEx) and operational expenditures (OpEx) are classified. An activity-based approach is used to quantify the cost of the event-driven operational processes such as repair and service provisioning. We discuss activity duration and availability parameters as required input data, which are necessary for calculating the processes' costs for realistic network scenarios. The relevant availability measures for an IP-over-Optical network are described using a triplet representation with optimistic, nominal, and conservative values. The model is applied to a reference German network scenario.

  14. 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

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

    International Nuclear Information System (INIS)

    We report on numerical simulations of a zincblende InP surface quantum dot (QD) on In0.48Ga0.52P buffer. Our model is strictly based on experimental structures, since we extrapolated a three-dimensional dot directly by atomic force microscopy results. Continuum electromechanical, k-vector ⋅ p-vector 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 k-vector ⋅ p-vector 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

  16. More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies

    Science.gov (United States)

    Amirav, Israel; Halamish, Asaf; Gorenberg, Miguel; Omar, Hamza; Newhouse, Michael T.

    2015-01-01

    Background Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic “face” surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more representative model face based on large numbers of actual faces. Aim To compare mask to “face” seal and aerosol delivery of two pediatric masks using a soft vs. a hard, appropriately representative, pediatric face model under various applied forces. Methods Two identical face models and upper airways replicas were constructed, the only difference being the suppleness and compressibility of the surface layer of the “face.” Integrity of the seal and aerosol delivery of two different masks [AeroChamber (AC) and SootherMask (SM)] were compared using a breath simulator, filter collection and realistic applied forces. Results The soft “face” significantly increased the delivery efficiency and the sealing characteristics of both masks. Aerosol delivery with the soft “face” was significantly greater for the SM compared to the AC (p< 0.01). No statistically significant difference between the two masks was observed with the hard “face.” Conclusions The material and pliability of the model “face” surface has a significant influence on both the seal and delivery efficiency of face masks. This finding should be taken into account during in-vitro aerosol studies. PMID:26090661

  17. More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies.

    Directory of Open Access Journals (Sweden)

    Israel Amirav

    Full Text Available Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic "face" surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more representative model face based on large numbers of actual faces.To compare mask to "face" seal and aerosol delivery of two pediatric masks using a soft vs. a hard, appropriately representative, pediatric face model under various applied forces.Two identical face models and upper airways replicas were constructed, the only difference being the suppleness and compressibility of the surface layer of the "face." Integrity of the seal and aerosol delivery of two different masks [AeroChamber (AC and SootherMask (SM] were compared using a breath simulator, filter collection and realistic applied forces.The soft "face" significantly increased the delivery efficiency and the sealing characteristics of both masks. Aerosol delivery with the soft "face" was significantly greater for the SM compared to the AC (p< 0.01. No statistically significant difference between the two masks was observed with the hard "face."The material and pliability of the model "face" surface has a significant influence on both the seal and delivery efficiency of face masks. This finding should be taken into account during in-vitro aerosol studies.

  18. Nonequilibrium processes from generalized Langevin equations: Realistic nanoscale systems connected to two thermal baths

    Science.gov (United States)

    Ness, H.; Genina, A.; Stella, L.; Lorenz, C. D.; Kantorovich, L.

    2016-05-01

    We extend the generalized Langevin equation (GLE) method [L. Stella, C. D. Lorenz, and L. Kantorovich, Phys. Rev. B 89, 134303 (2014), 10.1103/PhysRevB.89.134303] to model a central classical region connected to two realistic thermal baths at two different temperatures. In such nonequilibrium conditions a heat flow is established, via the central system, in between the two baths. The GLE-2B (GLE two baths) scheme permits us to have a realistic description of both the dissipative central system and its surrounding baths. Following the original GLE approach, the extended Langevin dynamics scheme is modified to take into account two sets of auxiliary degrees of freedom corresponding to the mapping of the vibrational properties of each bath. These auxiliary variables are then used to solve the non-Markovian dissipative dynamics of the central region. The resulting algorithm is used to study a model of a short Al nanowire connected to two baths. The results of the simulations using the GLE-2B approach are compared to the results of other simulations that were carried out using standard thermostatting approaches (based on Markovian Langevin and Nosé-Hoover thermostats). We concentrate on the steady-state regime and study the establishment of a local temperature profile within the system. The conditions for obtaining a flat profile or a temperature gradient are examined in detail, in agreement with earlier studies. The results show that the GLE-2B approach is able to treat, within a single scheme, two widely different thermal transport regimes, i.e., ballistic systems, with no temperature gradient, and diffusive systems with a temperature gradient.

  19. 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.

  20. 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.

  1. 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.

  2. 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…

  3. Realistic Approach of Strange Number System from Unary to Decimal

    Directory of Open Access Journals (Sweden)

    Debasis Das

    2012-01-01

    Full Text Available Numbers play an important role in Mathematics, also in Computer Science. A number is a symbol or group of symbols, or a word in a natural language that represents a numeral, which is different from numbers just as words differ from the things they refer to. A set of numbers in a framework that are represented by numerals in a consistent manner is called number system. In computing the study of number systems is useful to all, as a fact that various number systems are used in computer fields. Some are familiar number system (decimal (base 10, binary (base-2, octal (base-8 and hexadecimal (base-16 and others are strange number system (SNS. Strange number system is investigated for efficiently describing and implementing in digital systems. In computing the study of strange number system (SNS will useful to all researchers. Their awareness and detailed explanation is necessary for understanding various digital aspects. In this paper we have elaborate the concepts of strange number system (SNS, needs, number representation, arithmetic operations and inter conversion with different bases, represented in tabulated form. This paper will also helpful for knowledge seekers to easy understanding and practicing of number systems as well as to memories them

  4. 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.

  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. Assessing the outcomes of participatory research: protocol for identifying, selecting, appraising and synthesizing the literature for realist review

    Directory of Open Access Journals (Sweden)

    Greenhalgh Trish

    2011-03-01

    review methods. Discussion The systematic and stage-based procedure addressed challenges to PR assessment and generated our robust understanding of complex and heterogeneous PR practices. To date, realist reviews have focussed on evaluations of relatively uniform interventions. In contrast our PR search yielded a wide diversity of partnerships and research topics. We therefore developed tools to achieve conceptual clarity on the PR field, as a beneficial precursor to our theoretically-driven synthesis using realist methods. Findings from the ongoing review will be provided in forthcoming publications.

  7. Realistic 3D Terrain Roaming and Real-Time Flight Simulation

    Science.gov (United States)

    Que, Xiang; Liu, Gang; He, Zhenwen; Qi, Guang

    2014-12-01

    This paper presents an integrate method, which can provide access to current status and the dynamic visible scanning topography, to enhance the interactive during the terrain roaming and real-time flight simulation. A digital elevation model and digital ortho-photo map data integrated algorithm is proposed as the base algorithm for our approach to build a realistic 3D terrain scene. A new technique with help of render to texture and head of display for generating the navigation pane is used. In the flight simulating, in order to eliminate flying "jump", we employs the multidimensional linear interpolation method to adjust the camera parameters dynamically and steadily. Meanwhile, based on the principle of scanning laser imaging, we draw pseudo color figures by scanning topography in different directions according to the real-time flying status. Simulation results demonstrate that the proposed algorithm is prospective for applications and the method can improve the effect and enhance dynamic interaction during the real-time flight.

  8. 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.

  9. Active Harmonic Load–Pull With Realistic Wideband Communications Signals

    NARCIS (Netherlands)

    Marchetti, M.; Pelk, M.J.; Buisman, K.; Neo, W.C.E.; Spirito, M.; De Vreede, L.C.N.

    2008-01-01

    A new wideband open-loop active harmonic load–pull measurement approach is presented. The proposed method is based on wideband data-acquisition and wideband signal-injection of the incident and device generated power waves at the frequencies of interest. The system provides full, user defined, in-ba

  10. 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

  11. 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

  12. Applying a realistic evaluation model to occupational safety interventions

    DEFF Research Database (Denmark)

    Pedersen, Louise Møller

    2016-01-01

    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...

  13. Molecular simulation of realistic membrane models of alkylated PEEK membranes

    OpenAIRE

    Tocci, Elena; Pullumbi, Pluton

    2006-01-01

    Abstract Atomistic molecular modelling has proven to be a useful tool for the investigation of transport properties of small gas molecules in polymer membrane matrices. The quality of the predictions of these properties based on molecular simulation depends principally on the quality of the membrane model. The predicted gas transport properties of small gas molecules in the same glassy polymer membrane show often a large scatter in gas diffusion and solubility simulated values. In ...

  14. 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 artif......, the performance was equally good when using eight or four loudspeakers, and the reproduction method was shown to be robust for different program materials. The proposed technique to reduce audible artifacts increased the perceived similarity....

  15. The Realistic Mobility Evaluation of Vehicular Ad-Hoc Network for Indian Automotive Networks

    Directory of Open Access Journals (Sweden)

    V.S.Dhaka

    2014-04-01

    Full Text Available In recent years, continuous progress in wireless communication has opened a new research field in computer networks. Now a day’s wireless ad-hoc networking is an emerging research technology that needs attention of the industry people and the academicians. A vehicular ad-hoc network uses vehicles as mobile nodes to create mobility in a network. It’s a challenge to generate realistic mobility for Indian networks as no TIGER or Shapefile map is available for Indian Automotive Networks. This paper simulates the realistic mobility of the Vehicular Ad-hoc Networks (VANETs. The key feature of this work is the realistic mobility generation for the Indian Automotive Intelligent Transport System (ITS and also to analyze the throughput, packet delivery fraction (PDF and packet loss for realistic scenario. The experimental analysis helps in providing effective communication for safety to the driver and passengers.

  16. Universal method of strictly calculating self-consistent fields of realistic plasma particles

    OpenAIRE

    H. Lin

    2010-01-01

    A universal method of strictly calculating self-consistent fields of realistic plasma particles could be strictly derived from three basic tools in theoretical plasma physics: particle simulation, Vlasov-Maxwell theory and fluid theory.

  17. 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....

  18. Analysis of Heterogeneous Networks with Dual Connectivity in a Realistic Urban Deployment

    DEFF Research Database (Denmark)

    Gerardino, Guillermo Andrés Pocovi; Barcos, Sonia; Wang, Hua;

    2015-01-01

    the performance in this realistic layout. Due to the uneven load distribution observed in realistic deployments, DC is able to provide fast load balancing gains also at relatively high load - and not only at low load as typically observed in 3GPP scenarios. For the same reason, the proposed cell selection...... technique that aims at performing intra-layer load balancing shows promising benefits in this irregular deployment....

  19. Time and space in special relativity : a critique of the realist interpretation

    OpenAIRE

    Andersen, Fredrik

    2010-01-01

    The concepts of time and space as they are treated in the realist interpretation of Einstein's theory of Special Relativity are investigated and found wanting in coherence. The theoretical basis of what constitutes a valid scientific explanation is considered from the viewpoint of Kant and Kepler, and on this basis there is no proper scientific explanation provided by realist SRT for clock dilation and length contraction.

  20. CASCADE-IMEI: A learning environment of realistic mathematics for student teachers in Indonesia

    OpenAIRE

    Zulkardi; Nieveen, Nienke

    2001-01-01

    This paper reports on the second phase of a four-year study which aims to develop a learning environment that supports prospective mathematics teachers learning realistic mathematics education (RME) in teacher education in Indonesia. The results suggest that by giving student teachers experiences in doing mathematics as learners during a course and providing additional information about RME in a web site can increase their performance in teaching realistic mathematics in the school classroom.

  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. 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.

  3. Realistic evaluation of basemat uplift under seismic condition

    International Nuclear Information System (INIS)

    The results show that the uplift criteria which use a static method of computing the basemat uplift ratio based on linear time history analysis is too conservative. Also the criteria of reducing the building weight because of vertical seismic load consideration is too conservative. A nonlinear time history analysis of the basemat would result in a more accurate and smaller uplift ratio. It could be carried out quite cost effectively by state-of-art technique. The results also indicate that for the plant condition studied herein, the horizontal floor response spectra are not sensitive to the magnitude of uplift ratio, at least up to 50% by the nonlinear analysis method. The basemat FEM analysis results for the same plant subjected to the same seismic loadings indicate that the soil pressure and the basemat stress are within the allowable limits, even with substantially high basemat uplift ratio. Based on these considerations, the criteria of limiting the uplift ratio by 30% may be too conservative. However, for a soft foundation and smaller basemat case, the floor response spectra may be more significantly affected by a large basemat uplift ratio. (orig./HP)

  4. Use of a realistic breathing lung phantom to evaluate dose delivery errors

    International Nuclear Information System (INIS)

    Purpose: To compare the effect of respiration-induced motion on delivered dose (the interplay effect) for different treatment techniques under realistic clinical conditions. Methods: A flexible resin tumor model was created using rapid prototyping techniques based on a computed tomography (CT) image of an actual tumor. Twenty micro-MOSFETs were inserted into the tumor model and the tumor model was inserted into an anthropomorphic breathing phantom. Phantom motion was programed using the motion trajectory of an actual patient. A four-dimensional CT image was obtained and several treatment plans were created using different treatment techniques and planning systems: Conformal (Eclipse), step-and-shoot intensity-modulated radiation therapy (IMRT) (Pinnacle), step-and-shoot IMRT (XiO), dynamic IMRT (Eclipse), complex dynamic IMRT (Eclipse), hybrid IMRT [60% conformal, 40% dynamic IMRT (Eclipse)], volume-modulated arc therapy (VMAT) [single-arc (Eclipse)], VMAT [double-arc (Eclipse)], and complex VMAT (Eclipse). The complex plans were created by artificially pushing the optimizer to give complex multileaf collimator sequences. Each IMRT field was irradiated five times and each VMAT field was irradiated ten times, with each irradiation starting at a random point in the respiratory cycle. The effect of fractionation was calculated by randomly summing the measured doses. The maximum deviation for each measurement point per fraction and the probability that 95% of the model tumor had dose deviations less than 2% and 5% were calculated as a function of the number of fractions. Tumor control probabilities for each treatment plan were calculated and compared. Results: After five fractions, measured dose deviations were less than 2% for more than 95% of measurement points within the tumor model for all plans, except the complex dynamic IMRT, step-and-shoot IMRT (XiO), complex VMAT, and single-arc VMAT plans. Reducing the dose rate of the complex IMRT plans from 600 to 200 MU

  5. 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

  6. 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%).

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

    DEFF Research Database (Denmark)

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

    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...... distinct clusters that differed in the frequency of aberrant driving behavior and driving skills, as well as individual characteristics and driving related factors such as annual mileage, accident frequency and number of tickets and fines. Thus, two sub-groups were identified as more unsafe than the two......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...

  9. Quarkonium at finite temperature: Towards realistic phenomenology from first principles

    CERN Document Server

    Burnier, Yannis; Rothkopf, Alexander

    2015-01-01

    We present the finite temperature spectra of both bottomonium and charmonium, obtained from a consistent lattice QCD based potential picture. Starting point is the complex in-medium potential extracted on full QCD lattices with dynamical u,d and s quarks, generated by the HotQCD collaboration. Using the generalized Gauss law approach, vetted in a previous study on quenched QCD, we fit ${\\rm Re}[V]$ with a single temperature dependent parameter $m_D$, the Debye screening mass, and confirm the up to now tentative values of ${\\rm Im}[V]$. The obtained analytic expression for the complex potential allows us to compute quarkonium spectral functions by solving an appropriate Schr\\"odinger equation. These spectra exhibit thermal widths, which are free from the resolution artifacts that plague direct reconstructions from Euclidean correlators using Bayesian methods. In the present adiabatic setting, we find clear evidence for sequential melting and derive melting temperatures for the different bound states. Quarkoniu...

  10. Towards more realistic assessment of reactor accident consequences

    International Nuclear Information System (INIS)

    The purpose of the Nordic project described in the report has been to improve the data base used in accident consequence assessments, and also to improve the assessment models in use in the Nordic countries. The following data related questions have been dealt with: Terrestrial transfer factors, the freshwater pathways, comparison of dynamic and static calculation models for fish, and the shielding effect of buildings. The work on terrestrial transfer factors has resulted in the generation of a Nordic fallout data bank. The following experimental investigations have been performed: Natural decontamination of roofs under summer and winter conditions, deposition in urban areas, and the filter effect of buildings. Various aspects of mitigating actions have also been examined

  11. Realistic model for the stimulated Brillouin scattering instability

    International Nuclear Information System (INIS)

    The purpose of this work is to present a new model describing the stimulated Brillouin scattering instability in an inhomogeneous plasma. This model, called the harmonic decomposition method is based on the decomposition of plasma characteristics like density and speed into their short and long wavelengths components. This model describes: the propagation of the incident and reflected laser wave, the evolution of the sound wave and the hydrodynamic evolution of the plasma on a large scale. The first chapter recalls theoretical concepts concerning the stimulated Brillouin scattering, the filamentation and auto-focusing and introduces the harmonic decomposition method. The second chapter deals with the validation of this method through a comparison with an exact hydrodynamics model. The third chapter presents the interpretation of laser-plasma experiments with this new method. The fourth chapter presents different ways of improving the description by taking into account kinetics effects or a better decomposition of the sound wave. (A.C.)

  12. 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%). PMID:27616986

  13. The Influence of Realistic Reynolds Numbers on Slat Noise Simulations

    Science.gov (United States)

    Lockard, David P.; Choudhari, Meelan M.

    2012-01-01

    The slat noise from the 30P/30N high-lift system has been computed using a computational fluid dynamics code in conjunction with a Ffowcs Williams-Hawkings solver. Varying the Reynolds number from 1.71 to 12.0 million based on the stowed chord resulted in slight changes in the radiated noise. Tonal features in the spectra were robust and evident for all Reynolds numbers and even when a spanwise flow was imposed. The general trends observed in near-field fluctuations were also similar for all the different Reynolds numbers. Experiments on simplified, subscale high-lift systems have exhibited noticeable dependencies on the Reynolds number and tripping, although primarily for tonal features rather than the broadband portion of the spectra. Either the 30P/30N model behaves differently, or the computational model is unable to capture these effects. Hence, the results underscore the need for more detailed measurements of the slat cove flow.

  14. 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

  15. Linear stability of the wake and path of a rising bubble with a realistic shape

    Science.gov (United States)

    Cano-Lozano, José Carlos; Tchoufag, Joel; Magnaudet, Jacques; Fabre, David; Martínez-Bazán, Carlos

    2014-11-01

    A global linear stability analysis of the flow past a bubble rising in still liquid is carried out using the real bubble shape and the terminal velocity obtained for various sets of Galileo (Ga) and Bond (Bo) numbers in axisymmetric simulations performed with the multiphase software Gerris Flow Solver. Once the bubble shape is known, the axisymmetric, steady base flow is computed by means of an iterative Newton method with the finite element software FreeFem++, and the eigenvalue problem is solved with the shift-invert Arnoldi technique implemented in the SLEPc library. The critical curve separating stable and unstable regimes is obtained in the (Ga, Bo) and (Reynolds number, aspect ratio) spaces. This allows us to discuss the effect of the bubble shape and aspect ratio on the wake and path instabilities. We observe that the fore-and-aft asymmetry of the bubble has some influence on the stability since, for a given aspect ratio, bubbles with a realistic shape (i.e. a flatter front and a more rounded rear) are more stable that perfectly spheroidal bubbles. Supported by the Spanish MINECO, Junta de Andalucía and EU Funds under Projects DPI2011-28356-C03-03 and P11-TEP7495.

  16. 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.

  17. 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...

  18. Performance of Cooperative Eigenvalue Spectrum Sensing with a Realistic Receiver Model under Impulsive Noise

    Directory of Open Access Journals (Sweden)

    Dayan A. Guimarães

    2013-01-01

    Full Text Available In this paper we present a unified comparison of the performance of four detection techniques for centralized data-fusion cooperative spectrum sensing in cognitive radio networks under impulsive noise, namely, the eigenvalue-based generalized likelihood ratio test (GLRT, the maximum-minimum eigenvalue detection (MMED, the maximum eigenvalue detection (MED, and the energy detection (ED. We consider two system models: an implementation-oriented model that includes the most relevant signal processing tasks realized by a real cognitive radio receiver, and the theoretical model conventionally adopted in the literature. We show that under the implementation-oriented model, GLRT and MMED are quite robust under impulsive noise, whereas the performance of MED and ED is drastically degraded. We also show that performance under the conventional model can be too pessimistic if impulsive noise is present, whereas it can be too optimistic in the absence of this impairment. We also discuss the fact that impulsive noise is not such a severe problem when we take into account the more realistic implementation-oriented model.

  19. 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.

  20. Study of the three-nucleon continuum with realistic NN interactions

    International Nuclear Information System (INIS)

    Nucleon-deuteron elastic scattering and nucleon induced deuteron breakup were studied in the energy range of the incoming nucleon Elab=10+70 MeV. Rigorous Faddeev three-nucleon continuum calculations were performed with realistic, meson-exchange based on nucleon-nucleon interactions. Predictions gained with the Paris or Bonn potentials were compared with existing experimental data. For some elastic scattering observables very good quantitative description results are obtained. It was shown that careful study of particular elastic scattering polarization observables will play a role to nail down unsettled nucleon-nucleon force properties, which remain open by present day 2N experimental data. To such properties belong f.e. the charge independence breaking of the NN interaction in 3p waves or the proper strength of the 3S1-3D1 tensor force. Kinematically complete experimental data for various breakup configurations have been analysed. Significant discrepancies between theory and experiment found for some configurations can probably be attributed to the action of the 3-nucleon force. 97 refs., 7 figs. (author)

  1. A finite-element reciprocity solution for EEG forward modeling with realistic individual head models.

    Science.gov (United States)

    Ziegler, Erik; Chellappa, Sarah L; Gaggioni, Giulia; Ly, Julien Q M; Vandewalle, Gilles; André, Elodie; Geuzaine, Christophe; Phillips, Christophe

    2014-12-01

    We present a finite element modeling (FEM) implementation for solving the forward problem in electroencephalography (EEG). The solution is based on Helmholtz's principle of reciprocity which allows for dramatically reduced computational time when constructing the leadfield matrix. The approach was validated using a 4-shell spherical model and shown to perform comparably with two current state-of-the-art alternatives (OpenMEEG for boundary element modeling and SimBio for finite element modeling). We applied the method to real human brain MRI data and created a model with five tissue types: white matter, gray matter, cerebrospinal fluid, skull, and scalp. By calculating conductivity tensors from diffusion-weighted MR images, we also demonstrate one of the main benefits of FEM: the ability to include anisotropic conductivities within the head model. Root-mean square deviation between the standard leadfield and the leadfield including white-matter anisotropy showed that ignoring the directional conductivity of white matter fiber tracts leads to orientation-specific errors in the forward model. Realistic head models are necessary for precise source localization in individuals. Our approach is fast, accurate, open-source and freely available online. PMID:25204867

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

    International Nuclear Information System (INIS)

    An evident purpose of the radiological protection training is to use suitable protective equipment 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 geo-localization 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 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. (authors)

  3. 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 ...

  4. Particle deposition in a realistic geometry of the human conducting airways

    DEFF Research Database (Denmark)

    Koullapis, P. G.; Kassinos, S. C.; Bivolarova, Mariya Petrova;

    2016-01-01

    Understanding the multitude of factors that control pulmonary deposition is important in assessing the therapeutic or toxic effects of inhaled particles. The use of increasingly sophisticated in silico models has improved our overall understanding, but model realism remains elusive. In this work,...... between particle size, electrostatic charge, and flowrate. Our results suggest that in silico models should be customized for specific applications, ensuring all relevant physical effects are accounted for in a self-consistent fashion....... of inlet flow conditions, particle size, electrostatic charge, and flowrate. While most computer simulations assume a uniform velocity at the mouth inlet, we found that using a more realistic inlet profile based on Laser Doppler Anemometry measurements resulted in enhanced deposition, mostly on the tongue...... increased with flowrate, but remained significantly lower. Electrostatic charge increased the overall DF of smaller particles by as much as sevenfold, with most of the increase located in the mouth–throat. Moreover, significant enhancement in deposition was found in the left and right lung sub...

  5. Realistic opto-mechanical simulation and tolerancing of an automotive optical transmitter coupling system

    Science.gov (United States)

    Vervaeke, Michael; Moens, Els; Meuret, Youri; Ottevaere, Heidi; Van Buggenhout, Carl; De Pauw, Piet; Thienpont, Hugo

    2010-05-01

    The advent of Plastic Optical Fibre (POF) opened perspectives for numerous applications in the field of datacommunications. POF is increasingly popular in the automotive industry as a robust, lightweight, electromagnetic interference free, easy and cheap to install alternative to electrical wiring for high-speed entertainment, navigation and data acquisition systems in cars. The main challenge for the introduction of datacommunication systems based on POF is imposed by the working conditions of automotive applications: systems should remain fully functional in a temperature range from -40 °C to +115 °C . Furthermore, standardisation and mechanical design considerations put a number of other boundary conditions. We designed a misalignment-tolerant optical coupling system according to the Media Oriented Systems Transport standard (MOST) to convey the divergent beam from a Resonant Cavity Light Emitting Diode (RCLED) into a Step-Index (SI) multimode POF mounted in a detachable ferrule. In this contribution we describe the methodology to synthesize the dimensions and tolerances on the optical components in the coupling system. A Monte Carlo optimisation algorithm on the full three-dimensional (3D) description of the complete RCLED package and detachable POF ferrule was used to allow a realistic modelling of all misalignments that could occur in the production chain. We select the best suited system according to manufacturing and assembly capabilities as well as its suitability for automotive applications.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. Hybrid genetic algorithms: solutions in realistic dynamic and setup dependent job-shop scheduling problems

    Directory of Open Access Journals (Sweden)

    Rogério M. Branco

    2016-07-01

    Full Text Available This paper discusses the application of heuristic-based evolutionary technique in search for solutions concerning the dynamic job-shop scheduling problems with dependent setup times and alternate routes. With a combinatorial nature, these problems belong to an NP-hard class, with an aggravated condition when in realistic, dynamic and therefore, more complex cases than the traditional static ones. The proposed genetic algorithm executes two important functions: choose the routes using dispatching rules when forming each individual from a defined set of available machines and, also make the scheduling for each of these individuals created. The chromosome codifies a route, or the selected machines, and also an order to process the operations. In essence , each individual needs to be decoded by the scheduler to evaluate its time of completion, so the fitness function of the genetic algorithm, applying the modified Giffler and Thomson’s algorithm, obtains a scheduling of the selected routes in a given planning horizon. The scheduler considers the preparation time between operations on the machines and can manage operations exchange respecting the route and the order given by the chromosome. The best results in the evolutionary process are individuals with routes and processing orders optimized for this type of problema.

  11. The photochemistry of pyrimidine in realistic astrophysical ices and the production of nucleobases

    International Nuclear Information System (INIS)

    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 (C4H4N2) in H2O-rich ice mixtures that contain NH3, CH3OH, or CH4 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 H2O, CH3OH, and NH3, with or without CH4, 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.

  12. 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.

  13. Lepton Flavor Violation within a realistic SO(10)/G(224) Framework

    CERN Document Server

    Babu, K S; Rastogi, P K; Pati, Jogesh C.; Rastogi, Parul

    2005-01-01

    Lepton flavor violation (LFV) is studied within a realistic unified framework, based on supersymmetric SO(10) or an effective G(224) = SU(2)_L\\times SU(2)_R\\times SU(4)^c symmetry, that successfully describes (i) fermion masses and mixings, (ii) neutrino oscillations, as well as (iii) CP violation. LFV emerges as an important prediction of this framework, bringing no new parameters, barring the few SUSY parameters, which are assumed to be flavor-universal at M^*>= M_{GUT}. We study LFV (i.e. \\mu -> e\\gamma, \\tau -> \\mu\\gamma, \\tau -> e\\gamma and \\mu N -> e N) within this framework by including contributions both from the presence of the right handed neutrinos as well as those arising from renormalization group running in the post-GUT regime (M^* to M_{GUT}). Typically the latter, though commonly omitted in the literature, is found to dominate. Our predicted rates for \\mu -> e\\gamma show that while some choices of (m_o, m_{1/2}) are clearly excluded by the current empirical limit, this decay should be seen wit...

  14. Realistic thermal evolution models for Superearth Exo-solar planets

    Science.gov (United States)

    van den Berg, A.; Yuen, D.; Umemoto, K.; Wentzcovitch, R.; Jacobs, M.

    2012-04-01

    Massive superearth exoplanets in the range of one to ten times the Earth's mass have a much extended pressure regime compared to Earth, up to about 1 TPa, that may give rise to different material behavior. This has an impact on planetary evolution, and the evolution of a magnetic field and planetary atmosphere, and is therefore also relevant for habitability conditions. The material properties concerned include the mantle rheology where pressure affects both deep mantle viscosity and the brittle-ductile transition, both with a direct impact on lithosphere dynamics and the heat transport capacity of superearth mantle convection. Besides rheological considirations, other material properties also show strong variation with both pressure and temperature, in particular thermal expansivity and thermal conductivity. At ultra-high pressure they will exert a strong impact on the effectiveness of convective heat transport. The commonly used (extended) Boussinesq (EBA) convection model is not well suited for the pressure regime of superearth exoplanets becuase of the high value of the surface dissipation number involved, typically Di ~ 5 (van den Berg et al., Phys. Earth Planet. Inter.,178, 136-154). We therefore use a compressible convection model based on the anelastic liquid approximation and apply a selfconsistent model for the thermophysical properties based on ab-initio and lattice dynamics for relevant mantle silicates, perovskite, post-perovskite and periclase (Umemoto et al., Science,311, 983-986, 2006; Jacobs and van den Berg, Phys., Earth Planet. Inter.,186, 36-48, 2011). In particular our model includes, in a selfconsistent way, the significant temperature dependence of thermal expansivity, important in controlling the dynamics of cold downwellings in the upper mantle. We present results of convection modelling experiments exploring the forementioned model sensitivities on mantle heat transport both in transient cooling models and expressed in terms of Nusselt

  15. Soft Tissue Phantoms for Realistic Needle Insertion: A Comparative Study.

    Science.gov (United States)

    Leibinger, Alexander; Forte, Antonio E; Tan, Zhengchu; Oldfield, Matthew J; Beyrau, Frank; Dini, Daniele; Rodriguez Y Baena, Ferdinando

    2016-08-01

    Phantoms are common substitutes for soft tissues in biomechanical research and are usually tuned to match tissue properties using standard testing protocols at small strains. However, the response due to complex tool-tissue interactions can differ depending on the phantom and no comprehensive comparative study has been published to date, which could aid researchers to select suitable materials. In this work, gelatin, a common phantom in literature, and a composite hydrogel developed at Imperial College, were matched for mechanical stiffness to porcine brain, and the interactions during needle insertions within them were analyzed. Specifically, we examined insertion forces for brain and the phantoms; we also measured displacements and strains within the phantoms via a laser-based image correlation technique in combination with fluorescent beads. It is shown that the insertion forces for gelatin and brain agree closely, but that the composite hydrogel better mimics the viscous nature of soft tissue. Both materials match different characteristics of brain, but neither of them is a perfect substitute. Thus, when selecting a phantom material, both the soft tissue properties and the complex tool-tissue interactions arising during tissue manipulation should be taken into consideration. These conclusions are presented in tabular form to aid future selection. PMID:26666228

  16. 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.

  17. Internal Stresses For Realistic Asteroid Shapes: The Case Of Kleopatra

    Science.gov (United States)

    Hirabayashi, Masatoshi; Scheeres, D. J.

    2012-10-01

    We will present updated results for the averaged-normal stress and stress state within the asteroid Kleopatra. In this study we introduce a new method for computing the mutual gravity attraction of two generalized bodies in contact, which is applicable for computing the generalized stress field at any point within an asteroid. This methodology is applied to the asteroid Kleopatra, although computations for other asteroids will also be presented at the conference. Our method fills the asteroid shape with small equal-sized parallelepipeds and computes the higher order mutual gravity for each cube-pair. Since the gravitational attractions for pairs close to each other cannot be accurately modeled by a point mass assumption, we control the order of the gravity attraction computation by the relative distance. A validation test using the shape of an ellipsoid gives good agreement with the results of Holsapple (2001). We base our analysis on the radar-derived Kleopatra shape model (Ostro et al., 2009) with the updated total size and density from the (Deschamps et al., 2011) observations. Specifically we use a Kleopatra spin period of 5.38 hours and density of 3.2 g/cm3. The current results show that the asteroid is very close to being in a tensile state across its “neck” region and clearly has a localized stress concentration in this region. We will present results on the internal yield criterion and what limits can be inferred from this information.

  18. 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.

  19. Realistic Instrumentation Platform for Active and Passive Optical Remote Sensing.

    Science.gov (United States)

    Brydegaard, Mikkel; Merdasa, Aboma; Gebru, Alem; Jayaweera, Hiran; Svanberg, Sune

    2016-02-01

    We describe the development of a novel versatile optical platform for active and passive remote sensing of environmental parameters. Applications include assessment of vegetation status and water quality. The system is also adapted for ecological studies, such as identification of flying insects including agricultural pests. The system is based on two mid-size amateur astronomy telescopes, continuous-wave diode lasers at different wavelengths ranging from violet to the near infrared, and detector facilities including quadrant photodiodes, two-dimensional and line scan charge-coupled device cameras, and a compact digital spectrometer. Application examples include remote Ramanlaser-induced fluorescence monitoring of water quality at 120 m distance, and insect identification at kilometer ranges using the recorded wing beat frequency and its spectrum of overtones. Because of the low cost this developmental platform is very suitable for advanced research projects in developing countries and has, in fact, been multiplied during hands-on workshops and is now being used by a number of groups at African universities. PMID:26772187

  20. 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.

  1. Proposal For a Realistic, Attainable Lunar Astronomy Mission

    Science.gov (United States)

    Chen, Peter C.; Kondo, Yoji; Oliversen, Ronald J.

    The Moon is an immense optical bench in vacuum. Telescopes on the Moon, in the near future, can advance astrophysical research significantly. For example, it will be an ideal place for a very long baseline interferometry. The major obstacles in putting the Moon to full use as an observatory site have been the high cost of payloads and of placing them there. Our concern here is how to reduce the cost of payloads. We will show how new technologies, already available or in advanced stages of development, can be employed to reduce that cost. The key components are: (1) extremely low areal density optics, to reduce payload mass; (2) high temperature superconductor bearings, for non-contact cryogenic telescope drives; (3) smart, radiation resistant electronic array sensors; (4) miniature lander based on advanced propulsion technology. Reusable launch vehicles (RLVs), whose technologies are being tested with such innovative programs as DC-X, are expected to become available in several years at the beginning of the next century. RLVs can bring down the cost of reaching low Earth orbit to a fraction (from one tenth to one hundredth) of what it is today using expendable launch vehicles. The cost of transporting telescopes to the Moon can then be substantially reduced, making the lunar surface an even more attractive observatory site. A combination of the new technologies that already exist can make possible a lunar astronomy mission at a cost comparable to typical SMEX class (Small Explorer, US 50M) projects, even using currently available launch systems. The cost will be reduced much further when RLVs become operational. We discuss development in these areas at the NASA Goddard Space Center and else-where.

  2. 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.

  3. 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.

  4. TRACE - a time-dependent and realistic accident consequence evaluation module for use in emergency response planning

    International Nuclear Information System (INIS)

    Following the identification of an off-normal condition at nuclear power plant, the plant operators have one over-riding responsibility: protection of the offsite population. In discharging this responsibility, the operators utilize a set of emergency operating procdedures. A. Immediately following the identification of the off-normal condition, the operators primary actions are focused on establishing a safe, stable shutdown condition for the reactor. B. The plant condition is categorized according to the perceived severity of the event based on a broad overview of the plant conditions, and the information is transmitted to appropriate governmental authorities. C. Estimations of potential environmental releases of radioactivity, based on design basis accident results, are performed and transmitted to the governmental authorities. The TRACE package was developed to provide the operators with the tools to make realistic predictions of the range of possible releases of radioactivity to the environment during all phases of an off-normal condition, including severe accident situations. The TRACE package provides a means to project, during the early stages of an accident, the potential range of possible fission product releases on a realistic and time-dependent basis. The TRACE package also provides a means to update previous evaluations of the potential range of radioactivity releases as plant conditions change or a new information (on accident sequence or plant parameters) becomes available. (orig./HSCH)

  5. Dose related risk and effect assessment model (DREAM) -- A more realistic approach to risk assessment of offshore discharges

    International Nuclear Information System (INIS)

    Risk assessment of discharges from offshore oil and gas production to the marine environment features determination of potential environmental concentration (PEC) levels and no observed effect concentration (NOEC) levels. The PEC values are normally based on dilution of chemical components in the actual discharge source in the recipient, while the NOEC values are determined by applying a safety factor to acute toxic effects from laboratory tests. The DREAM concept focuses on realistic exposure doses as function of contact time and dilution, rather than fixed exposure concentrations of chemicals in long time exposure regimes. In its present state, the DREAM model is based on a number of assumptions with respect to the link between real life exposure doses and effects observed in laboratory tests. A research project has recently been initiated to develop the concept further, with special focus on chronic effects of different chemical compounds on the marine ecosystem. One of the questions that will be addressed is the link between exposure time, dose, concentration and effect. Validation of the safety factors applied for transforming acute toxic data into NOEC values will also be included. The DREAM model has been used by Statoil for risk assessment of discharges from new and existing offshore oil and gas production fields, and has been found to give a much more realistic results than conventional risk assessment tools. The presentation outlines the background for the DREAM approach, describes the model in its present state, discusses further developments and applications, and shows a number of examples on the performance of DREAM

  6. 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

  7. 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

  8. Non-Tachyonic Semi-Realistic Non-Supersymmetric Heterotic String Vacua

    CERN Document Server

    Ashfaque, Johar M; Faraggi, Alon E; Sonmez, Hasan

    2015-01-01

    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 mass...

  9. Statistical multipath exposure of a human in a realistic electromagnetic environment.

    Science.gov (United States)

    Vermeeren, Günter; Joseph, Wout; Olivier, Christof; Martens, Luc

    2008-04-01

    A new and fast numerical method is presented to assess the whole-body averaged specific absorption rate (SAR) in a human body model in a realistic electromagnetic environment. The method requires a minimum set of initial numerical simulations with a 3D electromagnetic solver. From the initial simulation results, the absorption can be quickly (within 1 s) determined in a realistic electromagnetic environment. The realistic electromagnetic environment has been modeled as a finite sum of incident plane waves. The presented fast method serves as a substitute for brute-force 3D electromagnetic simulations. Therefore, the method must only be validated with brute-force 3D electromagnetic simulations in terms of whole-body averaged SAR, and excellent agreement has been observed. The method has been applied to assess the cumulative distribution function of the whole-body averaged SAR in a spheroid human body model for four types of realistic electromagnetic environments. We observed that for all the four environments the whole-body averaged SAR complies with the International Commission on Non Ionizing Radiation Protection basic restriction for general public. Furthermore, the whole-body averaged SAR for a realistic exposure exceeds the worst-case single plane wave exposure in approximately 10% of the exposure samples. PMID:18332726

  10. 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.

  11. 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.

  12. CERN PS Booster space charge simulations with a realistic model for alignement and field errors

    CERN Document Server

    Forte, V; McAteer, M

    2014-01-01

    The CERN PS Booster is one of the machines of the LHC injector chain which will be upgraded within the LIU (LHC Injectors upgrade) project. The injection energy of the PSB will be increased to 160MeV in order to mitigate direct space charge effects, considered to be the main performance limitation, thus allowing 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. Efforts to establish a realistic modeling of field and alignment errors aim at extending the basic model of the machine towards a more realistic one. Simulations of beam dynamics with strong direct space charge and realistic errors are presented and analysed in this paper.

  13. A realist evaluation of the role of communities of practice in changing healthcare practice

    Directory of Open Access Journals (Sweden)

    Westbrook Johanna I

    2011-05-01

    Full Text Available Abstract Background Healthcare organisations seeking to manage knowledge and improve organisational performance are increasingly investing in communities of practice (CoPs. Such investments are being made in the absence of empirical evidence demonstrating the impact of CoPs in improving the delivery of healthcare. A realist evaluation is proposed to address this knowledge gap. Underpinned by the principle that outcomes are determined by the context in which an intervention is implemented, a realist evaluation is well suited to understand the role of CoPs in improving healthcare practice. By applying a realist approach, this study will explore the following questions: What outcomes do CoPs achieve in healthcare? Do these outcomes translate into improved practice in healthcare? What are the contexts and mechanisms by which CoPs improve healthcare? Methods The realist evaluation will be conducted by developing, testing, and refining theories on how, why, and when CoPs improve healthcare practice. When collecting data, context will be defined as the setting in which the CoP operates; mechanisms will be the factors and resources that the community offers to influence a change in behaviour or action; and outcomes will be defined as a change in behaviour or work practice that occurs as a result of accessing resources provided by the CoP. Discussion Realist evaluation is being used increasingly to study social interventions where context plays an important role in determining outcomes. This study further enhances the value of realist evaluations by incorporating a social network analysis component to quantify the structural context associated with CoPs. By identifying key mechanisms and contexts that optimise the effectiveness of CoPs, this study will contribute to creating a framework that will guide future establishment and evaluation of CoPs in healthcare.

  14. 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

  15. 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.

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

    International Nuclear Information System (INIS)

    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

  17. 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...

  18. 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

  19. 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.

  20. 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。

  1. 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.

  2. Multilayered disease-mimicking bladder phantom with realistic surface topology for optical coherence tomography

    Science.gov (United States)

    Smith, Gennifer T.; Lurie, Kristen L.; Khan, Saara A.; Liao, Joseph C.; Ellerbee, Audrey K.

    2014-03-01

    Optical coherence tomography (OCT) has shown potential as a complementary modality to white light cystoscopy (WLC), the gold standard for imaging bladder cancer. OCT can visualize sub-surface details of the bladder wall, which enables it to stage cancers and detect tumors that are otherwise invisible to WLC. Currently, OCT systems have too slow a speed and too small a field of view for comprehensive bladder imaging, which limits its clinical utility. Validation and feasibility testing of technological refinements aimed to provide faster imaging and wider fields of view necessitates a realistic bladder phantom. We present a novel process to fabricate the first such phantom that mimics both the optical and morphological properties of layers of the healthy and pathologic bladder wall as they characteristically appear with OCT. The healthy regions of the silicone-based phantom comprises three layers: the urothelium, lamina propria and muscularis propria, each containing an appropriate concentration of titanium dioxide to mimic its distinct scattering properties. As well, the layers each possess a unique surface appearance imposed by a textured mold. Within this phantom, pathologic tissue-mimicking regions are created by thickening specific layers or creating inclusions that disrupt the layered appearance of the bladder wall, as is characteristic of bladder carcinomas. This phantom can help to evaluate the efficacy of new OCT systems and software for tumor localization. Moreover, the procedure we have developed is highly generalizable for the creation of OCT-relevant, multi-layer phantoms for tissues that incorporate diseased states characterized by the loss of layered structures.

  3. Imaging hemorrhagic stroke with magnetic induction tomography: realistic simulation and evaluation

    International Nuclear Information System (INIS)

    Magnetic induction tomography (MIT) is a noncontact method for detecting the internal conductivity distribution of an object. This technology has the potential to be used in the biomedical area to check bio-impedance change inside the human body, for example to detect hemorrhage in the human brain. In this study the hemorrhagic stroke detectability with a 16-channel MIT system operating at 10 MHz was evaluated. Since the conductivity distribution is changed by the hemorrhagic stroke as well as the squeezed brain tissue around the stroke, deformation of the brain tissue is also considered and simulated with the help of a FEM-based linear bio-mechanical model in this paper. To simulate the raw measurement data as realistically as possible, the noise estimated from the experimental MIT system with hypothesis testing methods at 95% confidence level is added to the simulated measurements. Stroke images of 600 noisy samples for each detection assignment are reconstructed by the one-step Tikhonov-regularized inverse eddy current solution. Under the statistical framework, the detection failure is in control of a high false negative rate which represents a large artifact visualized in the reconstruction domain. The qualitative detectability of 18 detecting assignments, with three hemorrhagic positions (shallow, medial and center of the cerebrum) and two volume values (10 ml and 20 ml), overlaid by noise with three levels (standard deviation of phase change at 5 × 10−3°, 2.5 × 10−3°, 10 × 10−3°), are investigated. These detecting assignments are compared with each other to find out which volumes of deformed spherical hemorrhagic stroke can be detected by the modeled MIT system

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Coudarcher, Rémi; Duculty, Florent; Serot, Jocelyn; Jurie, Frédéric; Derutin, Jean-Pierre; Dhome, Michel

    2005-12-01

    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.

  7. Estimating a realistic procedural blank for the determination of Fe in seawater by isotope dilution: a fundamental analytical issue

    International Nuclear Information System (INIS)

    It is well known that direct analysis of seawater by means of inductively coupled plasma mass spectrometry (ICP-MS) is hardly possible because of the salt load in the samples. Determination of the element content at ultra-trace level in open-ocean water requires a separation from the matrix associated to significant concentration factors. For iron, an isotope dilution ICP-MS method was proposed based on a multiple steps protocol, including a co-precipitation with magnesium hydroxide after ammonia loading and consecutive dissolution with hydrochloric acid. To be able to measure the iron content in the low pg g-1 range a correct assessment of the analytical procedural blank is of crucial importance. Not only this blank must be low, but also realistic (i.e. based on the complete analytical sequence applied to real iron free seawater) and reproducible. This is particularly difficult considering the ubiquity of iron and the complexity of the seawater matrix and, despite years of experiments and publications, this remains a fundamental analytical challenge and a great source of complexity for the realisation of reliable profiles of dissolved iron data. The present study considers different approaches we developed to assess, in a realistic way, the procedural blank of the IDMS method proposed by Wu and Boyle. These authors use ∼4%-sample volume for their procedural blank determination, and the results presented are rather convincing. However, down-sizing by a factor of ∼25 the sample volume, which minimizes sample-tube contact and lab ware contribution to the blank, can easily lead to changes in the analytical protocol, and thus to non-realistic procedural blank values. Instead, our investigations aimed at reproducing the full set of experimental steps involved in the determination of iron in seawater by IDMS at the nM level or below. Our results are evaluated in the light of those claimed by Wu and Boyle. The ICP-MS measurements were performed by means of a single

  8. 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

  9. 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

  10. Achieving realistic performance and decison-making capabilities in computer-generated air forces

    Science.gov (United States)

    Banks, Sheila B.; Stytz, Martin R.; Santos, Eugene, Jr.; Zurita, Vincent B.; Benslay, James L., Jr.

    1997-07-01

    For a computer-generated force (CGF) system to be useful in training environments, it must be able to operate at multiple skill levels, exhibit competency at assigned missions, and comply with current doctrine. Because of the rapid rate of change in distributed interactive simulation (DIS) and the expanding set of performance objectives for any computer- generated force, the system must also be modifiable at reasonable cost and incorporate mechanisms for learning. Therefore, CGF applications must have adaptable decision mechanisms and behaviors and perform automated incorporation of past reasoning and experience into its decision process. The CGF must also possess multiple skill levels for classes of entities, gracefully degrade its reasoning capability in response to system stress, possess an expandable modular knowledge structure, and perform adaptive mission planning. Furthermore, correctly performing individual entity behaviors is not sufficient. Issues related to complex inter-entity behavioral interactions, such as the need to maintain formation and share information, must also be considered. The CGF must also be able to acceptably respond to unforeseen circumstances and be able to make decisions in spite of uncertain information. Because of the need for increased complexity in the virtual battlespace, the CGF should exhibit complex, realistic behavior patterns within the battlespace. To achieve these necessary capabilities, an extensible software architecture, an expandable knowledge base, and an adaptable decision making mechanism are required. Our lab has addressed these issues in detail. The resulting DIS-compliant system is called the automated wingman (AW). The AW is based on fuzzy logic, the common object database (CODB) software architecture, and a hierarchical knowledge structure. We describe the techniques we used to enable us to make progress toward a CGF entity that satisfies the requirements presented above. We present our design and

  11. 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…

  12. Lessons learned in using realist evaluation to assess maternal and newborn health programming in rural Bangladesh.

    Science.gov (United States)

    Adams, Alayne; Sedalia, Saroj; McNab, Shanon; Sarker, Malabika

    2016-03-01

    Realist evaluation furnishes valuable insight to public health practitioners and policy makers about how and why interventions work or don't work. Moving beyond binary measures of success or failure, it provides a systematic approach to understanding what goes on in the 'Black Box' and how implementation decisions in real life contexts can affect intervention effectiveness. This paper reflects on an experience in applying the tenets of realist evaluation to identify optimal implementation strategies for scale-up of Maternal and Newborn Health (MNH) programmes in rural Bangladesh. Supported by UNICEF, the three MNH programmes under consideration employed different implementation models to deliver similar services and meet similar MNH goals. Programme targets included adoption of recommended antenatal, post-natal and essential newborn care practices; health systems strengthening through improved referral, accountability and administrative systems, and increased community knowledge. Drawing on focused examples from this research, seven steps for operationalizing the realist evaluation approach are offered, while emphasizing the need to iterate and innovate in terms of methods and analysis strategies. The paper concludes by reflecting on lessons learned in applying realist evaluation, and the unique insights it yields regarding implementation strategies for successful MNH programming. PMID:26104820

  13. 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

  14. 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.

  15. 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…

  16. The Publishing House: From Being to Becoming--The Developmental Dimension in Realistic Work Environments

    Science.gov (United States)

    Boardman, Kay

    2010-01-01

    Purpose: The purpose of this paper is to suggest that the "skills" or "employability" agenda which has long been anathema to the Humanities disciplines need not be the threat it appears to represent. This paper aims to examine the concept of realistic work environments and their focus, not only the provision of hard and soft skills, but also the…

  17. 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. PMID:25051092

  18. 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

  19. 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…

  20. Realistic Mathematics Learning Using Cooperative Strategy Model in Junior High School

    Science.gov (United States)

    Dwiyana

    2015-01-01

    This study aims to develop a realistic mathematics learning model using cooperative strategy. This study applies research and development approach conducted at Junior High School "Laboratorium," State University of Malang. The implementation of this model is conducted through five stages: 1) previous study phase; 2) model planning phase;…

  1. 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

  2. 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

  3. 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…

  4. Realistic Shell-Model Calculations for Nuclei in the Region of Shell Closures off Stability

    OpenAIRE

    Covello, A; Coraggio, L.; Gargano, A.

    1998-01-01

    We have performed realistic shell-model calculations for nuclei around doubly magic 100Sn and 132Sn using an effective interaction derived from the Bonn A nucleon-nucleon potential. The results are in remarkably good agreement with the experimental data showing the ability of our effective interaction to provide an accurate description of nuclear structure properties.

  5. Transport in a realistic magnetic field modulated nanostructure with the δ-doping

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jian-Duo, E-mail: l_j316@163.com [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China); Xu, Bin [Department of Mathematics and Information Sciences, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450011 (China); Liu, Hong-Yu; Dai, Hou-Mei [Hubei Province Key Laboratory of Systems Science in Metallurgical Process, Wuhan University of Science and Technology, Wuhan 430081 (China)

    2014-01-10

    We theoretically investigate electron transport properties in a nanostructure modulated by the realistic magnetic field and the δ-doping. We find that the electron transport properties are strongly dependent on the weight and the position of the δ-doping. These interesting finds may be very helpful for designing the δ-doping-tunable spintronic devices.

  6. Realistic simulation of laser range finder behavior in a smoky environment

    NARCIS (Netherlands)

    O. Formsma; N. Dijkshoorn; S. van Noort; A. Visser

    2010-01-01

    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

  7. 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...

  8. Helping Students Succeed through Using Reflective Practice to Enhance Metacognition and Create Realistic Predictions

    Science.gov (United States)

    Mair, Carolyn

    2012-01-01

    Understanding how students can better manage their expectations has been a topic of interest in pedagogy for some time, yet solutions remain elusive. This paper describes a recent study which aimed to help students make more realistic predictions by increasing their metacognition. At the outset, participants completed a metacognitive awareness…

  9. Modelling Population Dynamics in Realistic Landscapes with Linear Elements: A Mechanistic-Statistical Reaction-Diffusion Approach.

    Science.gov (United States)

    Roques, Lionel; Bonnefon, Olivier

    2016-01-01

    We propose and develop a general approach based on reaction-diffusion equations for modelling a species dynamics in a realistic two-dimensional (2D) landscape crossed by linear one-dimensional (1D) corridors, such as roads, hedgerows or rivers. Our approach is based on a hybrid "2D/1D model", i.e, a system of 2D and 1D reaction-diffusion equations with homogeneous coefficients, in which each equation describes the population dynamics in a given 2D or 1D element of the landscape. Using the example of the range expansion of the tiger mosquito Aedes albopictus in France and its main highways as 1D corridors, we show that the model can be fitted to realistic observation data. We develop a mechanistic-statistical approach, based on the coupling between a model of population dynamics and a probabilistic model of the observation process. This allows us to bridge the gap between the data (3 levels of infestation, at the scale of a French department) and the output of the model (population densities at each point of the landscape), and to estimate the model parameter values using a maximum-likelihood approach. Using classical model comparison criteria, we obtain a better fit and a better predictive power with the 2D/1D model than with a standard homogeneous reaction-diffusion model. This shows the potential importance of taking into account the effect of the corridors (highways in the present case) on species dynamics. With regard to the particular case of A. albopictus, the conclusion that highways played an important role in species range expansion in mainland France is consistent with recent findings from the literature. PMID:26986201

  10. 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.)

  11. Generating Realistic Smart Grid Communication Topologies Based on Real-Data

    OpenAIRE

    Hartmann, Thomas; Fouquet, François; Klein, Jacques; Le Traon, Yves; PELOV, Alexander; Toutain, Laurent; ROPITAULT, Tanguy

    2014-01-01

    Today’s electricity grid must undergo substantial changes in order to keep pace with the rising demand for energy. The vision of the smart grid aims to increase the efficiency and reliability of today’s electricity grid, e.g. by integrating renewable energies and distributed micro-generations. The backbone of this effort is the facilitation of information and communication technologies to allow two-way communication and an automated control of devices. The underlying communication topology is...

  12. 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.

  13. Modeling and Design of Realistic Si3N4-based Integrated Optical Programmable Power Splitter

    NARCIS (Netherlands)

    Uranus, H.P.; Hoekstra, H.J.W.M.; Stoffer, R.

    2010-01-01

    Controllable splitting of optical power with a large splitting ratio range is often required in an integrated optical chip, e.g. for the readout of phase-shift in a slow-light sensor. In this work, we report the modeling and design of an integrated optical programmable power splitter consisting of a

  14. 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…

  15. 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...

  16. 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.

  17. 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...

  18. 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

  19. Parallel implementation of the particle simulation method with dynamic load balancing: Toward realistic geodynamical simulation

    Science.gov (United States)

    Furuichi, M.; Nishiura, D.

    2015-12-01

    Fully Lagrangian methods such as Smoothed Particle Hydrodynamics (SPH) and Discrete Element Method (DEM) have been widely used to solve the continuum and particles motions in the computational geodynamics field. These mesh-free methods are suitable for the problems with the complex geometry and boundary. In addition, their Lagrangian nature allows non-diffusive advection useful for tracking history dependent properties (e.g. rheology) of the material. These potential advantages over the mesh-based methods offer effective numerical applications to the geophysical flow and tectonic processes, which are for example, tsunami with free surface and floating body, magma intrusion with fracture of rock, and shear zone pattern generation of granular deformation. In order to investigate such geodynamical problems with the particle based methods, over millions to billion particles are required for the realistic simulation. Parallel computing is therefore important for handling such huge computational cost. An efficient parallel implementation of SPH and DEM methods is however known to be difficult especially for the distributed-memory architecture. Lagrangian methods inherently show workload imbalance problem for parallelization with the fixed domain in space, because particles move around and workloads change during the simulation. Therefore dynamic load balance is key technique to perform the large scale SPH and DEM simulation. In this work, we present the parallel implementation technique of SPH and DEM method utilizing dynamic load balancing algorithms toward the high resolution simulation over large domain using the massively parallel super computer system. Our method utilizes the imbalances of the executed time of each MPI process as the nonlinear term of parallel domain decomposition and minimizes them with the Newton like iteration method. In order to perform flexible domain decomposition in space, the slice-grid algorithm is used. Numerical tests show that our

  20. 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...

  1. 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.

  2. A Conjugate Fluid-Porous Approach for Simulating Airflow in Realistic Geometric Representations of the Human Respiratory System.

    Science.gov (United States)

    DeGroot, Christopher T; Straatman, Anthony G

    2016-03-01

    Simulation of flow in the human lung is of great practical interest as a means to study the detailed flow patterns within the airways for many physiological applications. While computational simulation techniques are quite mature, lung simulations are particularly complicated due to the vast separation of length scales between upper airways and alveoli. Many past studies have presented numerical results for truncated airway trees, however, there are significant difficulties in connecting such results with respiratory airway models. This article presents a new modeling paradigm for flow in the full lung, based on a conjugate fluid-porous formulation where the upper airway is considered as a fluid region with the remainder of the lung being considered as a coupled porous region. Results are presented for a realistic lung geometry obtained from computed tomography (CT) images, which show the method's potential as being more efficient and practical than attempting to directly simulate flow in the full lung. PMID:26630498

  3. A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

    Science.gov (United States)

    Smith, Jeremy C.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR

  4. Numerical investigation of sand production under realistic reservoir/well flow conditions

    Energy Technology Data Exchange (ETDEWEB)

    Nouri, A.; Kuru, E. [Alberta Univ., Edmonton, AB (Canada); Vaziri, H. [BP America USA (United States)

    2006-07-01

    The limitations of existing sand production prediction methods were discussed and a critical review of various sand production models was presented. A new numerical model embedded into ABAQUS was then developed to predict the onset and severity of sand production under realistic reservoir/well flow conditions. ABAQUS is a finite element program that simulates the interaction between fluid flow and mechanical deformation of a medium. The model makes it possible to predict critical drawdown leading to the onset of sanding as well as the rate of sand production in real time. It is based on the continuum mechanics approach for modeling the process of sanding as a function of many parameters that have an effect on sand production. These include a time-dependent coupled fluid flow and deformation analysis of the rock, material disaggregation, sand removal, and operational conditions such as drawdown, depletion, and water-cut. The model has been validated against sanding experiments conducted on hollow cylinder samples involving real time sand production measurements under various conditions. The samples were subjected to a gradual increase of axial and radial loadings under a single-phase flow condition. The Mohr-Coulomb model captured the mechanical response of the porous medium to the applied loading and seepage conditions. Modeling strain softening of the material was required in the simulation of sand production. Seepage drag forces tend to generate tensile stresses in a material that has gone through strain softening process and has lost its ability to carry any effective stresses. The results of the numerical modeling study were in good agreement with experimental data in terms of the operational conditions leading to the onset of sanding as well as an estimation of the sanding rate. The model presents a real-time evaluation of the ongoing alterations in the material at the wellface during the production and provides insight into the role of the various parameters

  5. 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”.

  6. Realistic nuclear shell theory and the doubly-magic 132Sn region

    International Nuclear Information System (INIS)

    After an introduction discussing the motivation and interest in results obtained with isotope separators, the fundamental problem in realistic nuclear shell theory is posed in the context of renormalization theory. Then some of the important developments that have occurred over the last fifteen years in the derivation of the effective Hamiltonian and application of realistic nuclear shell theory are briefly reviewed. Doubly magic regions of the periodic table and the unique advantages of the 132Sn region are described. Then results are shown for the ground-state properties of 132Sn as calculated from the density-dependent Hartree-Fock approach with the Skyrme Hamiltonian. A single theoretical Hamiltonian for all nuclei from doubly magic 132Sn to doubly magic 208Pb is presented; single-particle energies are graphed. Finally, predictions of shell-model level-density distributions obtained with spectral distribution methods are discussed; calculated level densities are shown for 136Xe. 10 figures

  7. 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.

  8. 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

  9. 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...

  10. GMO neighbourhoods - will co-existence be a geographically realistic possibility?

    DEFF Research Database (Denmark)

    Qvist, H. Witt; Lundsgaard, H.; Brandt, Jesper

    2006-01-01

    of the precautionary principle adopted in the Maastricht treaty from 1992 by the EU (Andersen, 2000). We concretised these rules in relation to actual landscape practices among primary producers of sugar beet in Denmark, we simulated the co-existence of GM and conventional sugar beet in an area of...... after the study took place. It is concluded that although the farmers are positive towards the possibility of introducing GM sugar beet, it is not realistic to expect the rules of co-existence to be observed, which makes the risk assessment behind the new rules unrealistical. Further studies of social...... practice in relation to trends and geographical variations in the distribution of structure, size and fragmentation of agricultural holdings are recommended in order to investigate possibilities for realistic co-existence....

  11. A computer-controlled pump and realistic anthropomorphic respiratory phantom for validating image-guided systems

    Science.gov (United States)

    Lin, Ralph; Wilson, Emmanuel; Tang, Jonathan; Stoianovici, Dan; Cleary, Kevin

    2007-03-01

    The development of image-guided interventions requires validation studies to evaluate new protocols. So far, these validation studies have been limited to animal models and to software and physical phantoms that simulate respiratory motion but cannot accommodate needle punctures in a realistic manner. We have built a computer-controlled pump that drives an anthropomorphic respiratory phantom for simulating natural breathing patterns. This pump consists of a power supply, a motion controller with servo amplifier, linear actuator, and custom fabricated pump assembly. By generating several sample waveforms, we were able to simulate typical breathing patterns. Using this pump, we were able to produce chest wall movements similar to typical chest wall movements observed in humans. This system has potential applications for evaluating new respiratory compensation algorithms and may facilitate improved testing of image-guided protocols under realistic interventional conditions.

  12. 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.

  13. [Importance of realistic tests for drug allergy: apropos of a clinical case].

    Science.gov (United States)

    Hassoun, S

    1998-11-01

    Drug allergy is the most difficult area in Allergology because: Clinical polymorphism and specially physiopathology (IgE-dependent hypersensibility reaction, cyclo-oxygenase inhibitor, etc.). Feeble specificity and sensitivity in the basic immunoallergic investigation (Skin tests, specific IgE). Very frequently his necessitates recourse to REALISTIC TESTS of drug re-introduction under clinical and biological surveillance (HSI mediators: histamine/tryptase/urinary methyl histamine) to produce a diagnosis. PMID:9887987

  14. Motivation of the nursing staff in and a framework of realistic motives in a public hospital

    OpenAIRE

    Yannis Markovits; Sofia Monastiridou

    2011-01-01

    The motivation of human resources and in particular of the nursing staff is a crucial issue that influences their job satisfaction, as well as patients' satisfaction from the health services offered. Aim: The presentation of selected motivation theories through literature review and the development of a framework of realistic motives applied to the nursing staff of a public hospital. Material-Method: The Greek and international bibliography has been reviewed, and in particular papers on the m...

  15. Traffic Control in ATM Networks : Engineering Impacts of Realistic Traffic Processes

    OpenAIRE

    Jena, Ajit K.; Popescu, Adrian; Pruthi, Parag; Erramilli, Ashok

    1996-01-01

    This paper reviews the current state of the art in the rapidly developing areas of ATM traffic controls and traffic modeling, and identifies future research areas to facilitate the implementation of control methods that can support a desired quality of service without sacrificing network utilizations. Two sets of issues are identified, one on the impacts of realistic traffic on the efficacy of traffic controls in supporting specific traffic management objectives, and the other dealing with th...

  16. More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies

    OpenAIRE

    Israel Amirav; Asaf Halamish; Miguel Gorenberg; Hamza Omar; Michael T Newhouse

    2015-01-01

    Background Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic “face” surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more...

  17. 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.

  18. A Critical Realist Analysis of Masculinity: Men Gravitating to a Dominant Masculine Norm

    OpenAIRE

    Lumb, Marcus

    2012-01-01

    This thesis documents a qualitative study investigating common patterns that cut across the behaviours of white, heterosexual, working and middle-class men. Previous literature has reported that men’s behaviour during their micro social relations is often risky and potentially harmful. This study provides an important contribution to knowledge regarding the motivation behind these patterns of behaviour. The research is rooted within a critical realist philosophical perspective. Of key im...

  19. A Preliminary Real-Time and Realistic Simulation Environment for Percutaneous Coronary Intervention

    OpenAIRE

    Jianhuang Wu; Haoyu Wang; Peng Zhang; Xin Ma; Qingmao Hu

    2015-01-01

    Percutaneous coronary intervention (PCI) is a minimally invasive surgery procedure that is widely used in the treatment of coronary artery disease. This procedure requires interventional cardiologists to have high proficiency and therefore demands an extensive training period in order to ensure successful surgical outcome. In this paper, a realistic and real-time interactive simulator for training PCI procedure is presented. A set of new approaches for core simulation components is devised an...

  20. Photo-realistic 3D modelling of sculptures on open-air museums

    OpenAIRE

    Francesca Duca; Miriam Cabrelles; Santiago Navarro; Ana Elena Segui; José Luis Lerma

    2011-01-01

    Creative Commons License This work is licensed under a Creative Commons Attribution 4.0 International License. Laser scanning is a high-end technology with possibilities far ahead the well-known civil engineering and industrial applications. The actual geomatic technologies and methodologies for cultural heritage documentation allow the generation of very realistic 3D results used for many scopes like archaeological documentation, digital conservation, 3D repositories, etc. The fast acq...

  1. 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 ...

  2. Realistic Image Rendition Using a Variable Exponent Functional Model for Retinex

    Directory of Open Access Journals (Sweden)

    Zeyang Dou

    2016-06-01

    Full Text Available The goal of realistic image rendition is to recover the acquired image under imperfect illuminant conditions, where non–uniform illumination may degrade image quality with high contrast and low SNR. In this paper, the assumption regarding illumination is modified and a variable exponent functional model for Retinex is proposed to remove non–uniform illumination and reduce halo artifacts. The theoretical derivation is provided and experimental results are presented to illustrate the effectiveness of the proposed model.

  3. Realistic Image Rendition Using a Variable Exponent Functional Model for Retinex.

    Science.gov (United States)

    Dou, Zeyang; Gao, Kun; Zhang, Bin; Yu, Xinyan; Han, Lu; Zhu, Zhenyu

    2016-01-01

    The goal of realistic image rendition is to recover the acquired image under imperfect illuminant conditions, where non-uniform illumination may degrade image quality with high contrast and low SNR. In this paper, the assumption regarding illumination is modified and a variable exponent functional model for Retinex is proposed to remove non-uniform illumination and reduce halo artifacts. The theoretical derivation is provided and experimental results are presented to illustrate the effectiveness of the proposed model. PMID:27338379

  4. Particles and gaseous emissions from realistic operation of residential wood pellet heating systems

    Science.gov (United States)

    Win, Kaung Myat; Persson, Tomas; Bales, Chris

    2012-11-01

    Gaseous and particulate emissions from six residential wood pellet heating systems are determined at a realistic six day operation sequence. The study aims to investigate the total emissions from a realistic operation of the heating systems including start-up and stop phases. Five combined solar and pellet heating systems and one reference boiler without solar system with an integrated DHW preparation was tested in a laboratory at realistic operation conditions. The investigated emissions comprised carbon monoxide (CO), nitrogen oxide (NO), total organic carbon (TOC) and particulate matter (PM2.5). In this study, the emissions are presented as accumulated total emissions from the whole six days period and the emissions from start-up and stop phases are also presented separately to evaluate the influence of the emissions from these phases on the total emissions. Emission factors of the measured systems from the six day period are between 192 and 547 mg MJ-1 for the CO emissions, between 61 and 95 mg MJ-1 for the NO, between 6 and 45 mg MJ-1 for the TOC, between 31 and 116 mg MJ-1 for the particulate matter and between 2.1 × 1013 and 4 × 1013 for the number of particles. The emissions from the start-up and stop phases are significantly high for the CO (63-95 %) and the TOC (48-93 %). NO and particles emissions are shown to dominate during stationary operation. However, 30-40 % of the particle emissions arise from the start and stop periods. It is also shown that the average emissions of CO, TOC and particles under the realistic annual conditions were higher than the limit values of two eco labels.

  5. Graphics processing units: more than the way to realistic video games

    OpenAIRE

    GARCIA-SUCERQUIA, JORGE; Trujillo, Carlos

    2011-01-01

    The huge market of the video games has propelled the development of hardware and software focused on making the game environment more realistic. Among such developments are the graphics processing units (GPU), which are intended to alleviate the central processing unit (CPU) of the host computer from the computation that creates “life” for the video games. GPUs reach this goal with the use of multiple computation cores operating on a parallel architecture; these features have made the GPUs at...

  6. 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.

  7. The current Afro-optimism – A realistic image of Africa?

    OpenAIRE

    Kjell Havnevik

    2015-01-01

    This chapter raises the question whether the current Afro-optimism can be considered a construction of a realistic image (situational) and a narrative (process) of Africa. It does so primarily by analyzing the 180 degree turn-around of the prestigious and influential magazine, The Economist, on Africa within the time span of a decade. In May 2000 the magazine claimed that Africa was a continent without hope, whereas in December 2011, Africa, according to The Economist, could be considered a c...

  8. Simulation of realistic rotor blade-vortex interactions using a finite-difference technique

    Science.gov (United States)

    Hassan, Ahmed A.; Charles, Bruce D.

    1989-01-01

    A numerical finite-difference code has been used to predict helicopter blade loads during realistic self-generated three-dimensional blade-vortex interactions. The velocity field is determined via a nonlinear superposition of the rotor flowfield. Data obtained from a lifting-line helicopter/rotor trim code are used to determine the instantaneous position of the interaction vortex elements with respect to the blade. Data obtained for three rotor advance ratios show a reasonable correlation with wind tunnel data.

  9. Management of long-term sickness absence: a systematic realist review

    OpenAIRE

    Higgins, Angela; O'Halloran, Peter; Porter, Samuel

    2012-01-01

    Purpose The increasing impact and costs of long term sickness absence have been well documented. However, the diversity and complexity of interventions and of the contexts in which these take place makes a traditional review problematic. Therefore, we undertook a systematic realist review to identify the dominant programme theories underlying best practice, to assess the evidence for these theories, and to throw light on important enabling or disabling contextual factors. MethodA search of th...

  10. A realistic example of chaotic tunneling: The hydrogen atom inparallel static electric and magnetic fields

    OpenAIRE

    Delande, Dominique; Zakrzewski, Jakub

    2003-01-01

    Statistics of tunneling rates in the presence of chaotic classical dynamics is discussed on a realistic example: a hydrogen atom placed in parallel uniform static electric and magnetic fields, where tunneling is followed by ionization along the fields direction. Depending on the magnetic quantum number, one may observe either a standard Porter-Thomas distribution of tunneling rates or, for strong scarring by a periodic orbit parallel to the external fields, strong deviations from it. For the ...

  11. 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…

  12. 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

  13. 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...

  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. 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.

  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. Obtaining a more realistic hydrogen distribution in the containment by coupling MELCOR with GASFLOW

    Energy Technology Data Exchange (ETDEWEB)

    Szabó, Tobias, E-mail: tobias.szabo@kit.edu; Kretzschmar, Frank, E-mail: frank.kretzschmar@kit.edu; Schulenberg, Thomas, E-mail: thomas.schulenberg@kit.edu

    2014-04-01

    Highlights: • Subsequent MELCOR and GASFLOW simulations are inconsistent. This inconsistency can be overcome by coupling both codes. • We tested the existing MELCOR coupling interface. • We developed and verified a coupling of MELCOR and GASFLOW. • We successfully applied the coupling to calculate a THAI experiment. • We compared the coupling to the common methodology. We found that the results from coupling were more realistic. - Abstract: The system code MELCOR provides an integral analysis capability for severe accidents in nuclear power plants. However, its Lumped Parameter model provides less accurate information about the thermal hydraulics in the containment during a loss of coolant accident. GASFLOW is a 3D CFD code that simulates the containment thermal hydraulics and the local hydrogen distribution more realistically. Currently, the common procedure is to use a source term from a previous MELCOR calculation in GASFLOW. Yet, the effect of the more realistic GASFLOW pressure to the mass flow through the leak cannot be taken into account in this approach. This inconsistency can be overcome by coupling both codes. First, the coupling interface existing in MELCOR 1.8.6 was tested by calculating a postulated accident in a simplified BWR using two coupled instances of MELCOR. The results agreed perfectly with the ones from a similar stand-alone calculation. Hence, MELCOR could be coupled to GASFLOW. A GASFLOW interface for an external, explicit, and asynchronous coupling to MELCOR was developed. It enabled to receive the source term from MELCOR and to send back the containment pressure during the run time. The correct functioning of this data exchange was verified for a representative blow-down problem. Moreover, we tested the coupling by calculating the TH7 experiment in the THAI facility with the coupled code system and with GASFLOW in stand-alone mode for comparison. The calculation results agreed very well to one another. Accordingly, the coupling

  18. Breast dose in mammography is about 30% lower when realistic heterogeneous glandular distributions are considered

    International Nuclear Information System (INIS)

    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 (pDgNhetero) and homogeneous (pDgNhomo) 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 pDgNhetero coefficients were on average 35.3% (SD, 4.1) and 24.2% (SD, 3.0) lower than the pDgNhomo 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 pDgNhetero relative to pDgNhomo of 23.6%–27.4% for a W–Rh spectrum. Displacement of the glandular distribution, at a distance equal to 10% of the compressed breast width in the superior and

  19. 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

  20. 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

  1. SELFAS2 : radio emission from cosmic ray air showers. Effect of realistic air refractive index

    CERN Document Server

    Marin, Vincent

    2012-01-01

    Using the simulation code SELFAS2, we present predictions of the radio signal emitted by extensive air showers (EAS) during their development in the atmosphere. The radio emission in the MHz range coming from air showers is the superposition of two mechanisms: the variation of the transverse current due to the systematic opposite drift of electrons and positrons in the Earth's magnetic field and the variation of the charge excess due to the electrons in excess in the shower front. In this paper, we stress particularly the effect of the realistic air refractive index on the radio signal predicted by SELFAS2.

  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. 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....

  4. 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

  5. A Performance Assessment of a Tactical Airborne Separation Assistance System using Realistic, Complex Traffic Flows

    Science.gov (United States)

    Smith, Jeremy C.; Neitzke, Kurt W.; Bussink, Frank J. L.

    2008-01-01

    This paper presents the results from a study that investigates the performance of aspects of an Airborne Separation Assistance System (ASAS) under varying demand levels using realistic traffic patterns. This study only addresses the tactical aspects of an ASAS using aircraft state data (latitude, longitude, altitude, heading and speed) to detect and resolve projected conflicts. The main focus of this paper is to determine the extent to which sole reliance on the proposed tactical ASAS can maintain aircraft separation at demand levels up to three times current traffic. The effect of mixing ASAS equipped aircraft with non-equipped aircraft that do not have the capability to self-separate is also investigated.

  6. 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.

  7. 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_\

  8. From Kuo–Brown to today's realistic shell-model calculations

    International Nuclear Information System (INIS)

    This paper is an homage to the seminal work of Gerry Brown and Tom Kuo, where shell model calculations were performed for 18O and 18F using an effective interaction derived from the Hamada–Johnston nucleon–nucleon potential. That work has been the first successful attempt to provide a description of nuclear structure properties starting from the free nucleon–nucleon potential. We shall compare the approach employed in the 1966 paper with the derivation of a modern realistic shell-model interaction for sd-shell nuclei, evidencing the progress that has been achieved during the last decades

  9. 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.

  10. From Kuo–Brown to today's realistic shell-model calculations

    Energy Technology Data Exchange (ETDEWEB)

    Coraggio, L. [Istituto Nazionale di Fisica Nucleare, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Covello, A. [Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Gargano, A. [Istituto Nazionale di Fisica Nucleare, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Itaco, N. [Istituto Nazionale di Fisica Nucleare, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy); Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Via Cintia, I-80126 Napoli (Italy)

    2014-08-15

    This paper is an homage to the seminal work of Gerry Brown and Tom Kuo, where shell model calculations were performed for {sup 18}O and {sup 18}F using an effective interaction derived from the Hamada–Johnston nucleon–nucleon potential. That work has been the first successful attempt to provide a description of nuclear structure properties starting from the free nucleon–nucleon potential. We shall compare the approach employed in the 1966 paper with the derivation of a modern realistic shell-model interaction for sd-shell nuclei, evidencing the progress that has been achieved during the last decades.

  11. Shell structure in neutron-rich Ca and Ni nuclei under semi-realistic mean fields

    OpenAIRE

    Nakada, H

    2010-01-01

    Shell structure in the neutron-rich Ca and Ni nuclei is investigated by the spherical Hartree-Fock calculations with the semi-realistic $NN$ interactions. Specific ingredients of the effective interaction, particularly the tensor force, often play a key role in the $Z$ dependence of the neutron shell structure. Such examples are found in N=32 and N=40; N=32 becomes magic or submagic in $^{52}$Ca while its magicity is broken in $^{60}$Ni, and N=40 is submagic (though not magic) in $^{68}$Ni bu...

  12. Predicting magic numbers of nuclei with semi-realistic nucleon-nucleon interactions

    OpenAIRE

    Nakada, H; Sugiura, K.

    2014-01-01

    Magic numbers are predicted in wide range of the nuclear chart by the self-consistent mean-field calculations with the M3Y-P6 and P7 semi-realistic $NN$ interactions. The magic numbers are identified by vanishing pair correlations in the spherical Hartree-Fock-Bogolyubov regime. We also identify submagic numbers when energy gain due to the pairing is sufficiently small. It is found that the results with M3Y-P6 well correspond to the known data, apart from a few exceptions. For some of the mag...

  13. Quantum Contextuality for a Three-Level System Sans Realist Model

    Science.gov (United States)

    Pan, A. K.; Mandal, K.

    2016-08-01

    Recently, an interesting form of non-classical effect which can be considered as a form of contextuality within quantum mechanics, has been demonstrated for a four-level system by discriminating the different routes that are taken for measuring a single observable. In this paper, we provide a simpler version of that proof for a single qutrit, which is also within the formalism of quantum mechanics and without recourse to any realist hidden variable model. The degeneracy of the eigenvalues and the L üder projection rule play important role in our proof.

  14. Simulation Evaluation of Controller-Managed Spacing Tools under Realistic Operational Conditions

    Science.gov (United States)

    Callantine, Todd J.; Hunt, Sarah M.; Prevot, Thomas

    2014-01-01

    Controller-Managed Spacing (CMS) tools have been developed to aid air traffic controllers in managing high volumes of arriving aircraft according to a schedule while enabling them to fly efficient descent profiles. The CMS tools are undergoing refinement in preparation for field demonstration as part of NASA's Air Traffic Management (ATM) Technology Demonstration-1 (ATD-1). System-level ATD-1 simulations have been conducted to quantify expected efficiency and capacity gains under realistic operational conditions. This paper presents simulation results with a focus on CMS-tool human factors. The results suggest experienced controllers new to the tools find them acceptable and can use them effectively in ATD-1 operations.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Realistic PET Monte Carlo Simulation With Pixelated Block Detectors, Light Sharing, Random Coincidences and Dead-Time Modeling

    Science.gov (United States)

    Guérin, Bastein; Fakhri, Georges El

    2008-01-01

    We have developed and validated a realistic simulation of random coincidences, pixelated block detectors, light sharing among crystal elements and dead-time in 2D and 3D positron emission tomography (PET) imaging based on the SimSET Monte Carlo simulation software. Our simulation was validated by comparison to a Monte Carlo transport code widely used for PET modeling, GATE, and to measurements made on a PET scanner. Methods We have modified the SimSET software to allow independent tracking of single photons in the object and septa while taking advantage of existing voxel based attenuation and activity distributions and validated importance sampling techniques implemented in SimSET. For each single photon interacting in the detector, the energy-weighted average of interaction points was computed, a blurring model applied to account for light sharing and the associated crystal identified. Detector dead-time was modeled in every block as a function of the local single rate using a variance reduction technique. Electronic dead-time was modeled for the whole scanner as a function of the prompt coincidences rate. Energy spectra predicted by our simulation were compared to GATE. NEMA NU-2 2001 performance tests were simulated with the new simulation as well as with SimSET and compared to measurements made on a Discovery ST (DST) camera. Results Errors in simulated spatial resolution (full width at half maximum, FWHM) were 5.5% (6.1%) in 2D (3D) with the new simulation, compared with 42.5% (38.2%) with SimSET. Simulated (measured) scatter fractions were 17.8% (21.3%) in 2D and 45.8% (45.2%) in 3D. Simulated and measured sensitivities agreed within 2.3 % in 2D and 3D for all planes and simulated and acquired count rate curves (including NEC) were within 12.7% in 2D in the [0: 80 kBq/cc] range and in 3D in the [0: 35 kBq/cc] range. The new simulation yielded significantly more realistic singles’ and coincidences’ spectra, spatial resolution, global sensitivity and lesion

  20. 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.

  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. 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)

  3. 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. PMID:26380357

  4. 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.

  5. Realistic texture extraction for 3D face models robust to self-occlusion

    Science.gov (United States)

    Qu, Chengchao; Monari, Eduardo; Schuchert, Tobias; Beyerer, Jürgen

    2015-02-01

    In the context of face modeling, probably the most well-known approach to represent 3D faces is the 3D Morphable Model (3DMM). When 3DMM is fitted to a 2D image, the shape as well as the texture and illumination parameters are simultaneously estimated. However, if real facial texture is needed, texture extraction from the 2D image is necessary. This paper addresses the possible problems in texture extraction of a single image caused by self-occlusion. Unlike common approaches that leverage the symmetric property of the face by mirroring the visible facial part, which is sensitive to inhomogeneous illumination, this work first generates a virtual texture map for the skin area iteratively by averaging the color of neighbored vertices. Although this step creates unrealistic, overly smoothed texture, illumination stays constant between the real and virtual texture. In the second pass, the mirrored texture is gradually blended with the real or generated texture according to the visibility. This scheme ensures a gentle handling of illumination and yet yields realistic texture. Because the blending area only relates to non-informative area, main facial features still have unique appearance in different face halves. Evaluation results reveal realistic rendering in novel poses robust to challenging illumination conditions and small registration errors.

  6. 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.

  7. 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...

  8. 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. PMID:22954859

  9. 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...

  10. 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: $ -...

  11. 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.

  12. Mathematical foundations for quantifying shape, shading, and cast shadows in realist master drawings and paintings

    Science.gov (United States)

    Stork, David G.

    2006-08-01

    The problem of inferring the two-dimensional location of an illuminant in an image, such as a digital photograph, has been studied as part of general scene analysis. One application area for analytical techniques and algorithms to this end is forensic image analysis, particularly in the detection of tampering and composites. For instance, if algorithms applied to two figures or two sections of an image reveal that these regions were captured under different lighting directions, it is highly likely that these regions were captured separately and later digitally integrated into the composite image, that is, the photograph was tampered. Recently some of these techniques have been applied to the study of realist master paintings and drawings in order to answer questions about the studio working methods of artists. We reveiw several sources of visual information about the location of the illuminant, stressing those most relevant to problems in the analysis of art, specifically paintings and drawings. We then present the foundations for a Bayesian method for integrating estimates from different sources, and then explore the application of such methods to the problem of inferring the location of the illuminant in realist paintings.

  13. Realistic modelling of the seismic input: Site effects and parametric studies

    International Nuclear Information System (INIS)

    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 structural models, allows us the construction of damage scenarios that are out of the reach of stochastic models, at a very low cost/benefit ratio. (author)

  14. 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.

  15. Vertical Velocities in Cumulus Convection: Implications for Climate and Prospects for Realistic Simulation at Cloud Scale

    Science.gov (United States)

    Donner, Leo

    2014-05-01

    Cumulus mass fluxes are essential controls on the interactions between cumulus convection and large-scale flows. Cumulus parameterizations have generally been built around them, and these parameterizations are basic components of climate models. Several important questions in climate science depend also on cumulus vertical velocities. Interactions between aerosols and convection comprise a prominent example, and scale-aware cumulus parameterizations that require explicit information about cumulus areas are another. Basic progress on these problems requires realistic characterization of cumulus vertical velocities from observations and models. Recent deployments of dual-Doppler radars are providing unprecedented observations, which can be compared against cloud-resolving models (CRMs). The CRMs can subsequently be analyzed to develop and evaluate parameterizations of vertical velocities in climate models. Vertical velocities from several cloud models will be compared against observations in this presentation. CRM vertical velocities will be found to depend strongly on model resolution and treatment of sub-grid turbulence and microphysics. Although many current state-of-science CRMs do not simulate vertical velocities well, recent experiments with these models suggest that with appropriate treatments of sub-grid turbulence and microphysics robustly realistic modeling of cumulus vertical velocities is possible.

  16. Structure and reactivity of a model catalyst alloy under realistic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Westerstroem, R; Gustafson, J; Resta, A; Mikkelsen, A; Andersen, J N; Lundgren, E [Department of Synchrotron Radiation Research, Lund University, Box 118, S-221 00 (Sweden); Wang, J G; Hammer, B [Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C (Denmark); Ackermann, M D; Frenken, J W M [Kamerlingh Onnes Laboratory, Leiden University, PO Box 9504, 2300 RA Leiden (Netherlands); Balmes, O [ESRF, 6, rue Jules Horowitz, F-38043 Grenoble cedex (France); Torrelles, X [Institut the Ciencia de Materials de Barcelona (C.S.I.C.), 08193, Bellaterra, Barcelona (Spain)], E-mail: Edvin.lundgren@sljus.lu.se

    2008-05-07

    Using a combined experimental and theoretical approach, we show that a thin RhO{sub 2} oxide film forms on a Pt{sub 25}Rh{sub 75}(100) surface at elevated oxygen pressures and temperatures prior to the bulk oxidation. By the use of in situ surface x-ray diffraction under realistic CO oxidation reaction conditions, we show that the onset of the growth of thin RhO{sub 2} oxide film coincides with an increase in CO{sub 2} production. During the reaction, the consumed oxide film is continuously re-grown by oxygen in the gas phase. Our theoretical results strongly suggest that the CO adsorbs on the metallic substrate but reacts with the O in the RhO{sub 2} oxide film at the border between the RhO{sub 2} oxide film and the metallic substrate. This scenario could explain the experimental observations of oxidation reactions on other late transition metal surfaces as well as on their corresponding nanoparticles under realistic conditions.

  17. How sharp is the chiral crossover phenomenon for realistic meson masses?

    CERN Document Server

    Meyer-Ortmanns, H; Meyer-Ortmanns, Hildegard; Schaefer, Bernd Jochen

    1996-01-01

    The mass dependence of the chiral phase transition is studied in the linear SU(3)\\times SU(3) sigma-model to leading order in a 1/N_f-expansion, N_f denoting the number of flavours. For realistic meson masses we find a smooth crossover between T\\sim181.5 to 192.6~[MeV]. The crossover looks more rapid in the light quark condensate than in thermodynamic quantities like the energy and entropy densities. The change in the light quark condensate in this temperature interval is \\sim~50\\% of the zero-temperature condensate value, while the entropy density increases by (5.5\\pm0.8)\\cdot10^{-3}~[GeV^3]. Since the numerical error is particularly large in this region, we cannot rule out a finite latent heat smaller than 0.2~[GeV/fm^3]. The chiral transition is washed out for an average pseudoscalar meson octet mass of 203~[MeV]. This gives an upper bound on the first-order transition region in the meson mass parameter space. The corresponding ratio of critical to realistic light current quark masses m^{crit}_{u,d}/m_{u,d...

  18. Generating Geospatially Realistic Driving Patterns Derived From Clustering Analysis Of Real EV Driving Data

    DEFF Research Database (Denmark)

    Pedersen, Anders Bro; Aabrandt, Andreas; Østergaard, Jacob;

    2014-01-01

    In order to provide a vehicle fleet that realistically represents the predicted Electric Vehicle (EV) penetration for the future, a model is required that mimics people driving behaviour rather than simply playing back collected data. When the focus is broadened from on a traditional user-centric...... the vehicles park, the model can be transferred geographically using known locations of the same classification.......In order to provide a vehicle fleet that realistically represents the predicted Electric Vehicle (EV) penetration for the future, a model is required that mimics people driving behaviour rather than simply playing back collected data. When the focus is broadened from on a traditional user......-centric smart charging approach to be more grid-centric, it suddenly becomes important to know not just when- and how much the vehicles charge, but also where in the grid they plug in. Since one of the main goals of EV-grid studies is to find the saturation point, it is equally important that the simulation...

  19. 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.

  20. 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.