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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. A realistic evaluation: the case of protocol-based care

    Science.gov (United States)

    2010-01-01

    Background 'Protocol based care' was envisioned by policy makers as a mechanism for delivering on the service improvement agenda in England. Realistic evaluation is an increasingly popular approach, but few published examples exist, particularly in implementation research. To fill this gap, within this paper we describe the application of a realistic evaluation approach to the study of protocol-based care, whilst sharing findings of relevance about standardising care through the use of protocols, guidelines, and pathways. Methods Situated between positivism and relativism, realistic evaluation is concerned with the identification of underlying causal mechanisms, how they work, and under what conditions. Fundamentally it focuses attention on finding out what works, for whom, how, and in what circumstances. Results In this research, we were interested in understanding the relationships between the type and nature of particular approaches to protocol-based care (mechanisms), within different clinical settings (context), and what impacts this resulted in (outcomes). An evidence review using the principles of realist synthesis resulted in a number of propositions, i.e., context, mechanism, and outcome threads (CMOs). These propositions were then 'tested' through multiple case studies, using multiple methods including non-participant observation, interviews, and document analysis through an iterative analysis process. The initial propositions (conjectured CMOs) only partially corresponded to the findings that emerged during analysis. From the iterative analysis process of scrutinising mechanisms, context, and outcomes we were able to draw out some theoretically generalisable features about what works, for whom, how, and what circumstances in relation to the use of standardised care approaches (refined CMOs). Conclusions As one of the first studies to apply realistic evaluation in implementation research, it was a good fit, particularly given the growing emphasis on

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

    International Nuclear Information System (INIS)

    Bjelkhagen, H I

    2013-01-01

    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.

  4. A Realistic Seizure Prediction Study Based on Multiclass SVM.

    Science.gov (United States)

    Direito, Bruno; Teixeira, César A; Sales, Francisco; Castelo-Branco, Miguel; Dourado, António

    2017-05-01

    A patient-specific algorithm, for epileptic seizure prediction, based on multiclass support-vector machines (SVM) and using multi-channel high-dimensional feature sets, is presented. The feature sets, combined with multiclass classification and post-processing schemes aim at the generation of alarms and reduced influence of false positives. This study considers 216 patients from the European Epilepsy Database, and includes 185 patients with scalp EEG recordings and 31 with intracranial data. The strategy was tested over a total of 16,729.80[Formula: see text]h of inter-ictal data, including 1206 seizures. We found an overall sensitivity of 38.47% and a false positive rate per hour of 0.20. The performance of the method achieved statistical significance in 24 patients (11% of the patients). Despite the encouraging results previously reported in specific datasets, the prospective demonstration on long-term EEG recording has been limited. Our study presents a prospective analysis of a large heterogeneous, multicentric dataset. The statistical framework based on conservative assumptions, reflects a realistic approach compared to constrained datasets, and/or in-sample evaluations. The improvement of these results, with the definition of an appropriate set of features able to improve the distinction between the pre-ictal and nonpre-ictal states, hence minimizing the effect of confounding variables, remains a key aspect.

  5. Realistic calculations of carbon-based disordered systems

    International Nuclear Information System (INIS)

    Rocha, A R; Fazzio, A; Rossi, Mariana; Silva, Antonio J R da

    2010-01-01

    Carbon nanotubes rank amongst potential candidates for a new family of nanoscopic devices, in particular for sensing applications. At the same time that defects in carbon nanotubes act as binding sites for foreign species, our current level of control over the fabrication process does not allow one to specifically choose where these binding sites will actually be positioned. In this work we present a theoretical framework for accurately calculating the electronic and transport properties of long disordered carbon nanotubes containing a large number of binding sites randomly distributed along a sample. This method combines the accuracy and functionality of ab initio density functional theory to determine the electronic structure with a recursive Green's functions method. We apply this methodology on the problem of nitrogen-rich carbon nanotubes, first considering different types of defects and then demonstrating how our simulations can help in the field of sensor design by allowing one to compute the transport properties of realistic nanotube devices containing a large number of randomly distributed binding sites.

  6. 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

    For WLAN systems in which relaying is exploited for improving throughput performance, node mobility and in- formation collection delays can have a significant impact on the performance of a relay selection scheme. This paper analyzes this influence on the decision process using a previously...... 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...

  7. Developing Teaching Material Based on Realistic Mathematics Andoriented to the Mathematical Reasoning and Mathematical Communication

    OpenAIRE

    Habsah, Fitria

    2017-01-01

    This research aims to produce mathematics textbook for grade VII junior high school students based on realistic mathematics and oriented to the mathematical reasoning and mathematical communication. The quality is determined based on Nieveen criteria, including validity, practicality, and effectiveness.This study was a research and development and used Borg & Gall model. The subject of this research were the students of SMPN 2 Pujon-Kabupaten Malang, that is 30 students in an experimental cla...

  8. 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.

  9. 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

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

    International Nuclear Information System (INIS)

    Kiarashi, Nooshin; Nolte, Adam C.; Sturgeon, Gregory M.; Ghate, Sujata V.; Segars, William P.; Nolte, Loren W.; Samei, Ehsan

    2015-01-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-15

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

  12. 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...

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

    Science.gov (United States)

    Durham, Jo; Bains, Amara

    2015-03-25

    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 and contestability, in particular, is a coherent reform process is largely absent. Contestability operates on the premise that better procurement processes allow more providers to enter the market and compete for contracts. This is expected to create stimulus for greater efficiencies, innovation and improved service delivery to consumers. There is limited understanding, however, about how community-based providers morph and re-configure in response to the opportunities posed by contestability. This study focuses on the effect of a contestability policy on the community-managed mental health sector. A realist review will be undertaken to understand how and why the introduction of contestability into a previously incontestable market influences the ways in which community-based mental health providers respond to contestability. The review will investigate those circumstances that shape organisational response and generate outcomes through activating mechanisms. An early scoping has helped to formulate the initial program theory. A realist synthesis will be undertaken to identify relevant journal articles and grey literature. Data will be extracted in relation to the emerging contextual factors, mechanisms and outcomes and their configurations. The analysis will seek patterns and regularities in these configurations across the extracted data and will focus on addressing our theory-based questions. Increasingly, community-based mental health markets are moving to contestability models. Rigorous

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

    Directory of Open Access Journals (Sweden)

    Jonathan B Alberts

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

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

    International Nuclear Information System (INIS)

    Romanelli, F.; Panza, G.F.; Vaccari, F.

    2002-11-01

    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 accelerograms using as input a set of parameters that describes, to the best of our knowledge, the geological structure and seismotectonic setting of the investigated area. (author)

  16. Developing teaching material based on realistic mathematics andoriented to the mathematical reasoning and mathematical communication

    Directory of Open Access Journals (Sweden)

    Fitria Habsah

    2017-05-01

    Full Text Available This research aims to produce mathematics textbook for grade VII junior high school students based on realistic mathematics and oriented to the mathematical reasoning and mathematical communication. The quality is determined based on Nieveen criteria, including validity, practicality, and effectiveness.This study was a research and development and used Borg & Gall model. The subject of this research were the students of SMPN 2 Pujon-Kabupaten Malang, that is 30 students in an experimental class (using the developed textbook and 29 students in a control class (using BSE book from the government. The teaching material was categorized valid if the expert's judgment at least is categorized as “good”. The teaching material was categorized practical if both of teachers and students assessment at least categorized as “good”. The teaching material was categorized effectively if minimum 75% of student scores at least is categorized as “good” for the mathematical reasoning test and mathematical communication test. This research resulted in a valid, practical, and effective teaching material. The resulted of the validation show that material teaching is valid. The resulted of teachers and students assessment show that the product is practical. The tests scores show that the product is effective. Percentage of students who categorized at least as “good” is 83,33% for the mathematical reasoning and 86,67% for the mathematical communication. The resulted of statistic test shows that the product more effective than the BSE book from the government in terms of mathematical reasoning and mathematical communication.

  17. Improvements on a simple muscle-based 3D face for realistic facial expressions

    NARCIS (Netherlands)

    Bui, T.D.; Heylen, Dirk K.J.; Nijholt, Antinus; Badler, N.; Thalmann, D.

    2003-01-01

    Facial expressions play an important role in face-to-face communication. With the development of personal computers capable of rendering high quality graphics, computer facial animation has produced more and more realistic facial expressions to enrich human-computer communication. In this paper, we

  18. 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.

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

    Science.gov (United States)

    Lesperance, Marielle; Inglis-Whalen, M; Thomson, R M

    2014-02-01

    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(125)I, (103)Pd, or (131)Cs seeds, and to investigate doses to ocular structures. 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. 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%. In the full eye model

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

    International Nuclear Information System (INIS)

    Lesperance, Marielle; Inglis-Whalen, M.; Thomson, R. M.

    2014-01-01

    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 125 I, 103 Pd, or 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 simulation by up

  1. 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

  2. 3D realistic head model simulation based on transcranial magnetic stimulation.

    Science.gov (United States)

    Yang, Shuo; Xu, Guizhi; Wang, Lei; Chen, Yong; Wu, Huanli; Li, Ying; Yang, Qingxin

    2006-01-01

    Transcranial magnetic stimulation (TMS) is a powerful non-invasive tool for investigating functions in the brain. The target inside the head is stimulated with eddy currents induced in the tissue by the time-varying magnetic field. Precise spatial localization of stimulation sites is the key of efficient functional magnetic stimulations. Many researchers devote to magnetic field analysis in empty free space. In this paper, a realistic head model used in Finite Element Method has been developed. The magnetic field inducted in the head bt TMS has been analysed. This three-dimensional simulation is useful for spatial localization of stimulation.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-09-16

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

  4. Computational Aerodynamic Analysis of a Micro-CT Based Bio-Realistic Fruit Fly Wing

    Science.gov (United States)

    Brandt, Joshua; Doig, Graham; Tsafnat, Naomi

    2015-01-01

    The aerodynamic features of a bio-realistic 3D fruit fly wing in steady state (snapshot) flight conditions were analyzed numerically. The wing geometry was created from high resolution micro-computed tomography (micro-CT) of the fruit fly Drosophila virilis. Computational fluid dynamics (CFD) analyses of the wing were conducted at ultra-low Reynolds numbers ranging from 71 to 200, and at angles of attack ranging from -10° to +30°. It was found that in the 3D bio-realistc model, the corrugations of the wing created localized circulation regions in the flow field, most notably at higher angles of attack near the wing tip. Analyses of a simplified flat wing geometry showed higher lift to drag performance values for any given angle of attack at these Reynolds numbers, though very similar performance is noted at -10°. Results have indicated that the simplified flat wing can successfully be used to approximate high-level properties such as aerodynamic coefficients and overall performance trends as well as large flow-field structures. However, local pressure peaks and near-wing flow features induced by the corrugations are unable to be replicated by the simple wing. We therefore recommend that accurate 3D bio-realistic geometries be used when modelling insect wings where such information is useful. PMID:25954946

  5. A Local-Realistic Model of Quantum Mechanics Based on a Discrete Spacetime

    Science.gov (United States)

    Sciarretta, Antonio

    2018-01-01

    This paper presents a realistic, stochastic, and local model that reproduces nonrelativistic quantum mechanics (QM) results without using its mathematical formulation. The proposed model only uses integer-valued quantities and operations on probabilities, in particular assuming a discrete spacetime under the form of a Euclidean lattice. Individual (spinless) particle trajectories are described as random walks. Transition probabilities are simple functions of a few quantities that are either randomly associated to the particles during their preparation, or stored in the lattice nodes they visit during the walk. QM predictions are retrieved as probability distributions of similarly-prepared ensembles of particles. The scenarios considered to assess the model comprise of free particle, constant external force, harmonic oscillator, particle in a box, the Delta potential, particle on a ring, particle on a sphere and include quantization of energy levels and angular momentum, as well as momentum entanglement.

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

    Directory of Open Access Journals (Sweden)

    Mohammed Hazim Alkawaz

    2014-01-01

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

  7. 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

  8. Realistic outcomes.

    Science.gov (United States)

    Cowan, Tracy

    2012-04-01

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

  9. 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

  10. 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.

  11. 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

    2016-03-24

    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. 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. 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 Synthesis: Evolving Standards guidelines. Once completed

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2007-06-25

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

  13. Effective electric fields along realistic DTI-based neural trajectories for modelling the stimulation mechanisms of TMS

    International Nuclear Information System (INIS)

    De Geeter, N; Crevecoeur, G; Dupré, L; Leemans, A

    2015-01-01

    In transcranial magnetic stimulation (TMS), an applied alternating magnetic field induces an electric field in the brain that can interact with the neural system. It is generally assumed that this induced electric field is the crucial effect exciting a certain region of the brain. More specifically, it is the component of this field parallel to the neuron’s local orientation, the so-called effective electric field, that can initiate neuronal stimulation. Deeper insights on the stimulation mechanisms can be acquired through extensive TMS modelling. Most models study simple representations of neurons with assumed geometries, whereas we embed realistic neural trajectories computed using tractography based on diffusion tensor images. This way of modelling ensures a more accurate spatial distribution of the effective electric field that is in addition patient and case specific. The case study of this paper focuses on the single pulse stimulation of the left primary motor cortex with a standard figure-of-eight coil. Including realistic neural geometry in the model demonstrates the strong and localized variations of the effective electric field between the tracts themselves and along them due to the interplay of factors such as the tract’s position and orientation in relation to the TMS coil, the neural trajectory and its course along the white and grey matter interface. Furthermore, the influence of changes in the coil orientation is studied. Investigating the impact of tissue anisotropy confirms that its contribution is not negligible. Moreover, assuming isotropic tissues lead to errors of the same size as rotating or tilting the coil with 10 degrees. In contrast, the model proves to be less sensitive towards the not well-known tissue conductivity values. (paper)

  14. 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.

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

    Science.gov (United States)

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

    2013-01-01

    Adjusting hemodynamics via flow diverter (FD) implantation is emerging as a novel method of treating cerebral aneurysms. However, most previous FD-related hemodynamic studies were based on virtual FD deployment, which may produce different hemodynamic outcomes than realistic (in vivo) FD deployment. We compared hemodynamics between virtual FD and realistic FD deployments in rabbit aneurysm models using computational fluid dynamics (CFD) simulations. FDs were implanted for aneurysms in 14 rabbits. Vascular models based on rabbit-specific angiograms were reconstructed for CFD studies. Real FD configurations were reconstructed based on micro-CT scans after sacrifice, while virtual FD configurations were constructed with SolidWorks software. Hemodynamic parameters before and after FD deployment were analyzed. According to the metal coverage (MC) of implanted FDs calculated based on micro-CT reconstruction, 14 rabbits were divided into two groups (A, MC >35%; B, MC FD deployment, but pressure was not (P>0.05). The normalized mean WSS in Group A after realistic FD implantation was significantly lower than that of Group B. All parameters in Group B exhibited no significant difference between realistic and virtual FDs. This study confirmed MC-correlated differences in hemodynamic parameters between realistic and virtual FD deployment.

  16. 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.

  17. Normal and Pathological NCAT Image and Phantom Data Based on Physiologically Realistic Left Ventricle Finite-Element Models

    International Nuclear Information System (INIS)

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

    2006-01-01

    The 4D NURBS-based Cardiac-Torso (NCAT) phantom, which provides a realistic model of the normal human anatomy and cardiac and respiratory motions, is used in medical imaging research to evaluate and improve imaging devices and techniques, especially dynamic cardiac applications. One limitation of the phantom is that it lacks the ability to accurately simulate altered functions of the heart that result from cardiac pathologies such as coronary artery disease (CAD). The goal of this work was to enhance the 4D NCAT phantom by incorporating a physiologically based, finite-element (FE) mechanical model of the left ventricle (LV) to simulate both normal and abnormal cardiac motions. The geometry of the FE mechanical model was based on gated high-resolution x-ray multi-slice computed tomography (MSCT) data of a healthy male subject. The myocardial wall was represented as transversely isotropichyperelastic material, with the fiber angle varying from -90 degrees at the epicardial surface, through 0 degrees at the mid-wall, to 90 degrees at the endocardial surface. A time varying elastance model was used to simulate fiber contraction, and physiological intraventricular systolic pressure-time curves were applied to simulate the cardiac motion over the entire cardiac cycle. To demonstrate the ability of the FE mechanical model to accurately simulate the normal cardiac motion as well abnormal motions indicative of CAD, a normal case and two pathologic cases were simulated and analyzed. In the first pathologic model, a subendocardial anterior ischemic region was defined. A second model was created with a transmural ischemic region defined in the same location. The FE based deformations were incorporated into the 4D NCAT cardiac model through the control points that define the cardiac structures in the phantom which were set to move according to the predictions of the mechanical model. A simulation study was performed using the FE-NCAT combination to investigate how the

  18. 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

  19. Using Realist Synthesis to Develop an Evidence Base from an Identified Data Set on Enablers and Barriers for Alcohol and Drug Program Implementation

    Science.gov (United States)

    Hunter, Barbara; MacLean, Sarah; Berends, Lynda

    2012-01-01

    The purpose of this paper is to show how "realist synthesis" methodology (Pawson, 2002) was adapted to review a large sample of community based projects addressing alcohol and drug use problems. Our study drew on a highly varied sample of 127 projects receiving funding from a national non-government organisation in Australia between 2002…

  20. Agent-based modeling traction force mediated compaction of cell-populated collagen gels using physically realistic fibril mechanics.

    Science.gov (United States)

    Reinhardt, James W; Gooch, Keith J

    2014-02-01

    Agent-based modeling was used to model collagen fibrils, composed of a string of nodes serially connected by links that act as Hookean springs. Bending mechanics are implemented as torsional springs that act upon each set of three serially connected nodes as a linear function of angular deflection about the central node. These fibrils were evaluated under conditions that simulated axial extension, simple three-point bending and an end-loaded cantilever. The deformation of fibrils under axial loading varied <0.001% from the analytical solution for linearly elastic fibrils. For fibrils between 100 μm and 200 μm in length experiencing small deflections, differences between simulated deflections and their analytical solutions were <1% for fibrils experiencing three-point bending and <7% for fibrils experiencing cantilever bending. When these new rules for fibril mechanics were introduced into a model that allowed for cross-linking of fibrils to form a network and the application of cell traction force, the fibrous network underwent macroscopic compaction and aligned between cells. Further, fibril density increased between cells to a greater extent than that observed macroscopically and appeared similar to matrical tracks that have been observed experimentally in cell-populated collagen gels. This behavior is consistent with observations in previous versions of the model that did not allow for the physically realistic simulation of fibril mechanics. The significance of the torsional spring constant value was then explored to determine its impact on remodeling of the simulated fibrous network. Although a stronger torsional spring constant reduced the degree of quantitative remodeling that occurred, the inclusion of torsional springs in the model was not necessary for the model to reproduce key qualitative aspects of remodeling, indicating that the presence of Hookean springs is essential for this behavior. These results suggest that traction force mediated matrix

  1. Bayesian Population Physiologically-Based Pharmacokinetic (PBPK Approach for a Physiologically Realistic Characterization of Interindividual Variability in Clinically Relevant Populations.

    Directory of Open Access Journals (Sweden)

    Markus Krauss

    Full Text Available Interindividual variability in anatomical and physiological properties results in significant differences in drug pharmacokinetics. The consideration of such pharmacokinetic variability supports optimal drug efficacy and safety for each single individual, e.g. by identification of individual-specific dosings. One clear objective in clinical drug development is therefore a thorough characterization of the physiological sources of interindividual variability. In this work, we present a Bayesian population physiologically-based pharmacokinetic (PBPK approach for the mechanistically and physiologically realistic identification of interindividual variability. The consideration of a generic and highly detailed mechanistic PBPK model structure enables the integration of large amounts of prior physiological knowledge, which is then updated with new experimental data in a Bayesian framework. A covariate model integrates known relationships of physiological parameters to age, gender and body height. We further provide a framework for estimation of the a posteriori parameter dependency structure at the population level. The approach is demonstrated considering a cohort of healthy individuals and theophylline as an application example. The variability and co-variability of physiological parameters are specified within the population; respectively. Significant correlations are identified between population parameters and are applied for individual- and population-specific visual predictive checks of the pharmacokinetic behavior, which leads to improved results compared to present population approaches. In the future, the integration of a generic PBPK model into an hierarchical approach allows for extrapolations to other populations or drugs, while the Bayesian paradigm allows for an iterative application of the approach and thereby a continuous updating of physiological knowledge with new data. This will facilitate decision making e.g. from preclinical to

  2. 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.

  3. 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-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 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’ character who were treated by realistic mathematics education is better then students’ character who 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  Keywords: Critical Thinking, Students’ Character, Realistic Mathematics Education Culture-Based DOI: http://dx.doi.org/10.22342/jme.4.1.566.75-94

  4. Community-based services for homeless adults experiencing concurrent mental health and substance use disorders: a realist approach to synthesizing evidence.

    Science.gov (United States)

    O'Campo, Patricia; Kirst, Maritt; Schaefer-McDaniel, Nicole; Firestone, Michelle; Scott, Allison; McShane, Kelly

    2009-11-01

    Consultations with community-based service providers in Toronto identified a lack of strong research evidence about successful community-based interventions that address the needs of homeless clients experiencing concurrent mental health and substance use disorders. We undertook a collaborative research effort between academic-based and community-based partners to conduct a systematic evidence synthesis drawing heavily from Pawson's realist review methodology to focus on both whether programs are successful and why and how they lead to improved outcomes. We examined scholarly and nonscholarly literature to explore program approaches and program elements that lead to improvements in mental health and substance use disorders among homeless individuals with concurrent disorders (CD). Information related to program contexts, elements, and successes and failures were extracted and further supplemented by key informant interviews and author communication regarding reviewed published studies. From the ten programs that we reviewed, we identified six important and promising program strategies that reduce mental health and, to a far lesser degree, substance use problems: client choice in treatment decision-making, positive interpersonal relationships between client and provider, assertive community treatment approaches, providing supportive housing, providing supports for instrumental needs, and nonrestrictive program approaches. These promising program strategies function, in part, by promoting and supporting autonomy among homeless adults experiencing CD. Our realist informed review is a useful methodology for synthesizing complex programming information on community-based interventions.

  5. Development of an evidence-based complex intervention for community rehabilitation of patients with hip fracture using realist review, survey and focus groups.

    Science.gov (United States)

    Roberts, Jessica Louise; Din, Nafees Ud; Williams, Michelle; Hawkes, Claire A; Charles, Joanna M; Hoare, Zoe; Morrison, Val; Alexander, Swapna; Lemmey, Andrew; Sackley, Catherine; Logan, Phillipa; Wilkinson, Clare; Rycroft-Malone, Jo; Williams, Nefyn H

    2017-10-11

    To develop an evidence and theory-based complex intervention for improving outcomes in elderly patients following hip fracture. Complex-intervention development (Medical Research Council (MRC) framework phase I) using realist literature review, surveys and focus groups of patients and rehabilitation teams. North Wales. Surveys of therapy managers (n=13), community and hospital-based physiotherapists (n=129) and occupational therapists (n=68) throughout the UK. Focus groups with patients (n=13), their carers (n=4) and members of the multidisciplinary rehabilitation teams in North Wales (n=13). The realist review provided understanding of how rehabilitation interventions work in the real-world context and three programme theories were developed: improving patient engagement by tailoring the intervention to individual needs; reducing fear of falling and improving self-efficacy to exercise and perform activities of daily living; and coordination of rehabilitation delivery. The survey provided context about usual rehabilitation practice; focus groups provided data on the experience, acceptability and feasibility of rehabilitation interventions. An intervention to enhance usual rehabilitation was developed to target these theory areas comprising: a physical component consisting of six additional therapy sessions; and a psychological component consisting of a workbook to enhance self-efficacy and a patient-held goal-setting diary for self-monitoring. A realist approach may have advantages in the development of evidence-based interventions and can be used in conjunction with other established methods to contribute to the development of potentially more effective interventions. A rehabilitation intervention was developed which can be tested in a future randomised controlled trial (MRC framework phases II and III). ISRCTN22464643, Pre-results. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No

  6. Loss of conformational entropy in protein folding calculated using realistic ensembles and its implications for NMR-based calculations

    Science.gov (United States)

    Baxa, Michael C.; Haddadian, Esmael J.; Jumper, John M.; Freed, Karl F.; Sosnick, Tobin R.

    2014-01-01

    The loss of conformational entropy is a major contribution in the thermodynamics of protein folding. However, accurate determination of the quantity has proven challenging. We calculate this loss using molecular dynamic simulations of both the native protein and a realistic denatured state ensemble. For ubiquitin, the total change in entropy is TΔSTotal = 1.4 kcal⋅mol−1 per residue at 300 K with only 20% from the loss of side-chain entropy. Our analysis exhibits mixed agreement with prior studies because of the use of more accurate ensembles and contributions from correlated motions. Buried side chains lose only a factor of 1.4 in the number of conformations available per rotamer upon folding (ΩU/ΩN). The entropy loss for helical and sheet residues differs due to the smaller motions of helical residues (TΔShelix−sheet = 0.5 kcal⋅mol−1), a property not fully reflected in the amide N-H and carbonyl C=O bond NMR order parameters. The results have implications for the thermodynamics of folding and binding, including estimates of solvent ordering and microscopic entropies obtained from NMR. PMID:25313044

  7. Does the Food Stamp Program cause obesity? A realist review and a call for place-based research.

    Science.gov (United States)

    DeBono, Nathaniel L; Ross, Nancy A; Berrang-Ford, Lea

    2012-07-01

    The high prevalence of obesity among low income groups has led some to question the role of food assistance programs in contributing to the problem. The USDA's Food Stamp Program (now known as the Supplemental Nutrition Assistance Program - SNAP) is the largest food assistance program in the United States with over 40 million participants. This paper employed systematic realist review methods to determine whether participation in the Food Stamp Program causes obesity and the causal pathways through which this relationship may exist. Findings indicate a more consistent positive relationship for women than for men, especially for women who are long term users of the program. All studies discussed the "food stamp cycle" and an "income effect" as explanations for the role of food stamps in increased obesity yet evidence for these factors is limited. Curiously, the research in this field does not address obesogenic environments and we suggest that the absence of an understanding of household behavior in local contexts is a significant impediment to the reform of the Food Stamp Program. Copyright © 2012 Elsevier Ltd. All rights reserved.

  8. MR-based measurements and simulations of the magnetic field created by a realistic transcranial magnetic stimulation (TMS) coil and stimulator.

    Science.gov (United States)

    Mandija, Stefano; Petrov, Petar I; Neggers, Sebastian F W; Luijten, Peter R; van den Berg, Cornelis A T

    2016-11-01

    Transcranial magnetic stimulation (TMS) is an emerging technique that allows non-invasive neurostimulation. However, the correct validation of electromagnetic models of typical TMS coils and the correct assessment of the incident TMS field (B TMS ) produced by standard TMS stimulators are still lacking. Such a validation can be performed by mapping B TMS produced by a realistic TMS setup. In this study, we show that MRI can provide precise quantification of the magnetic field produced by a realistic TMS coil and a clinically used TMS stimulator in the region in which neurostimulation occurs. Measurements of the phase accumulation created by TMS pulses applied during a tailored MR sequence were performed in a phantom. Dedicated hardware was developed to synchronize a typical, clinically used, TMS setup with a 3-T MR scanner. For comparison purposes, electromagnetic simulations of B TMS were performed. MR-based measurements allow the mapping and quantification of B TMS starting 2.5 cm from the TMS coil. For closer regions, the intra-voxel dephasing induced by B TMS prohibits TMS field measurements. For 1% TMS output, the maximum measured value was ~0.1 mT. Simulations reflect quantitatively the experimental data. These measurements can be used to validate electromagnetic models of TMS coils, to guide TMS coil positioning, and for dosimetry and quality assessment of concurrent TMS-MRI studies without the need for crude methods, such as motor threshold, for stimulation dose determination. Copyright © 2016 John Wiley & Sons, Ltd.

  9. Filling America's fiber intake gap: summary of a roundtable to probe realistic solutions with a focus on grain-based foods.

    Science.gov (United States)

    Clemens, Roger; Kranz, Sibylle; Mobley, Amy R; Nicklas, Theresa A; Raimondi, Mary Pat; Rodriguez, Judith C; Slavin, Joanne L; Warshaw, Hope

    2012-07-01

    Current fiber intakes are alarmingly low, with long-term implications for public health related to risk of coronary heart disease, stroke, hypertension, certain gastrointestinal disorders, obesity, and the continuum of metabolic dysfunctions including prediabetes and type 2 diabetes. Eating patterns high in certain fibers are known to lower LDL cholesterol and blood pressure, lower blood glucose, and decrease insulin resistance in people with prediabetes and type 2 diabetes; help with both weight loss and maintenance; and improve bowel regularity and gastrointestinal health. With >90% of adults and children who fall short of meeting their daily fiber recommendations, the 2010 Dietary Guidelines for Americans once again classified fiber as a nutrient of concern. Despite efforts over the past decade to promote adequate fiber through fruit, vegetable, and whole-grain intakes, fiber consumption has remained flat at approximately half the daily recommended amount. The public health implications of inadequate fiber intake prompted the roundtable session "Filling America's Fiber Gap: Probing Realistic Solutions," which assembled nutrition researchers, educators, and communicators to identify challenges, opportunities, and realistic solutions to help fill the current fiber gap. The roundtable discussions highlighted the need for both consumer and professional education to improve acceptance for and inclusion of grain-based foods with added fiber as one strategy for increasing fiber intakes within daily energy goals.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  11. Understanding the impact of area-based interventions on area safety in deprived areas: realist evaluation of a neighbour nuisance intervention in Arnhem, the Netherlands.

    Science.gov (United States)

    Kramer, Daniëlle; Harting, Janneke; Kunst, Anton E

    2016-03-31

    Area-based health inequalities may partly be explained by higher levels of area disorder in deprived areas. Area disorder may cause safety concerns and hence impair health. This study assessed how, for whom and in what conditions the intervention Meeting for Care and Nuisance (MCN) had an impact on neighbour nuisance and area safety in four deprived districts in Arnhem, the Netherlands. Realist evaluation methodology was applied to uncover how, for whom, and under what conditions MCN was expected to and actually produced change. Expected change was based on action plans and scientific theories. Actual change was based on progress reports, media articles, interviews with district managers, and quantitative surveys. Three levels of impact were distinguished. At the organisational level, partly as expected, MCN's coordinated partnership strategy enabled role alignment, communication, and leadership. This resulted in a more efficient approach of nuisance households. At the level of nuisance households, as expected, MCN's joint assistance and enforcement strategy removed many of the underlying reasons for nuisance. This resulted in less neighbour nuisance. At the district level, perceptions of social control and area safety improved only in one district. Key conditions for change included a wider safety approach, dense population, and central location of the district within the city. This realist evaluation provided insight into the mechanisms by which a complex area-based intervention was able to reduce neighbour nuisance in deprived areas. Depending on wider conditions, such a reduction in neighbour nuisance may or may not lead to improved perceptions of area safety at the district level.

  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. Realistic Material Appearance Modelling

    Czech Academy of Sciences Publication Activity Database

    Haindl, Michal; Filip, Jiří; Hatka, Martin

    2010-01-01

    Roč. 2010, č. 81 (2010), s. 13-14 ISSN 0926-4981 R&D Projects: GA ČR GA102/08/0593 Institutional research plan: CEZ:AV0Z10750506 Keywords : bidirectional texture function * texture modelling Subject RIV: BD - Theory of Information http://library.utia.cas.cz/separaty/2010/RO/haindl-realistic material appearance modelling.pdf

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

    International Nuclear Information System (INIS)

    Zhou Hailiang; Zhang Minxuan; Hao Yue

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Benoit M

    2015-03-01

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

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

    Directory of Open Access Journals (Sweden)

    Batas-Bjelić Ilija

    2015-01-01

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

  17. Getting realistic; Endstation Demut

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, J.P.

    2004-01-28

    The fuel cell hype of the turn of the millenium has reached its end. The industry is getting realistic. If at all, fuel cell systems for private single-family and multiple dwellings will not be available until the next decade. With a Europe-wide field test, Vaillant intends to advance the PEM technology. [German] Der Brennstoffzellen-Hype der Jahrtausendwende ist verfolgen. Die Branche uebt sich in Bescheidenheit. Die Marktreife der Systeme fuer Ein- und Mehrfamilienhaeuser wird - wenn ueberhaupt - wohl erst im naechsten Jahrzehnt erreicht sein. Vaillant will durch einen europaweiten Feldtest die Entwicklung der PEM-Technologie vorantreiben. (orig.)

  18. Lithium Depletion in Solar-like Stars: Effect of Overshooting Based on Realistic Multi-dimensional Simulations

    International Nuclear Information System (INIS)

    Baraffe, I.; Pratt, J.; Goffrey, T.; Constantino, T.; Viallet, M.; Folini, D.; Popov, M. V.; Walder, R.

    2017-01-01

    We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by multi-dimensional fully compressible, time-implicit hydrodynamic simulations performed with the MUSIC code. Intermittent convective mixing at the convective boundary in a star can be modeled using extreme value theory, a statistical analysis frequently used for finance, meteorology, and environmental science. In this Letter, we implement this statistical diffusion coefficient in a one-dimensional stellar evolution code, using parameters calibrated from multi-dimensional hydrodynamic simulations of a young low-mass star. We propose a new scenario that can explain observations of the surface abundance of lithium in the Sun and in clusters covering a wide range of ages, from ∼50 Myr to ∼4 Gyr. Because it relies on our physical model of convective penetration, this scenario has a limited number of assumptions. It can explain the observed trend between rotation and depletion, based on a single additional assumption, namely, that rotation affects the mixing efficiency at the convective boundary. We suggest the existence of a threshold in stellar rotation rate above which rotation strongly prevents the vertical penetration of plumes and below which rotation has small effects. In addition to providing a possible explanation for the long-standing problem of lithium depletion in pre-main-sequence and main-sequence stars, the strength of our scenario is that its basic assumptions can be tested by future hydrodynamic simulations.

  19. Lithium Depletion in Solar-like Stars: Effect of Overshooting Based on Realistic Multi-dimensional Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Baraffe, I.; Pratt, J.; Goffrey, T.; Constantino, T.; Viallet, M. [Astrophysics Group, University of Exeter, Exeter EX4 4QL (United Kingdom); Folini, D.; Popov, M. V.; Walder, R., E-mail: i.baraffe@ex.ac.uk [Ecole Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, F-69364 Lyon Cedex 07 (France)

    2017-08-10

    We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by multi-dimensional fully compressible, time-implicit hydrodynamic simulations performed with the MUSIC code. Intermittent convective mixing at the convective boundary in a star can be modeled using extreme value theory, a statistical analysis frequently used for finance, meteorology, and environmental science. In this Letter, we implement this statistical diffusion coefficient in a one-dimensional stellar evolution code, using parameters calibrated from multi-dimensional hydrodynamic simulations of a young low-mass star. We propose a new scenario that can explain observations of the surface abundance of lithium in the Sun and in clusters covering a wide range of ages, from ∼50 Myr to ∼4 Gyr. Because it relies on our physical model of convective penetration, this scenario has a limited number of assumptions. It can explain the observed trend between rotation and depletion, based on a single additional assumption, namely, that rotation affects the mixing efficiency at the convective boundary. We suggest the existence of a threshold in stellar rotation rate above which rotation strongly prevents the vertical penetration of plumes and below which rotation has small effects. In addition to providing a possible explanation for the long-standing problem of lithium depletion in pre-main-sequence and main-sequence stars, the strength of our scenario is that its basic assumptions can be tested by future hydrodynamic simulations.

  20. Lithium Depletion in Solar-like Stars: Effect of Overshooting Based on Realistic Multi-dimensional Simulations

    Science.gov (United States)

    Baraffe, I.; Pratt, J.; Goffrey, T.; Constantino, T.; Folini, D.; Popov, M. V.; Walder, R.; Viallet, M.

    2017-08-01

    We study lithium depletion in low-mass and solar-like stars as a function of time, using a new diffusion coefficient describing extra-mixing taking place at the bottom of a convective envelope. This new form is motivated by multi-dimensional fully compressible, time-implicit hydrodynamic simulations performed with the MUSIC code. Intermittent convective mixing at the convective boundary in a star can be modeled using extreme value theory, a statistical analysis frequently used for finance, meteorology, and environmental science. In this Letter, we implement this statistical diffusion coefficient in a one-dimensional stellar evolution code, using parameters calibrated from multi-dimensional hydrodynamic simulations of a young low-mass star. We propose a new scenario that can explain observations of the surface abundance of lithium in the Sun and in clusters covering a wide range of ages, from ˜50 Myr to ˜4 Gyr. Because it relies on our physical model of convective penetration, this scenario has a limited number of assumptions. It can explain the observed trend between rotation and depletion, based on a single additional assumption, namely, that rotation affects the mixing efficiency at the convective boundary. We suggest the existence of a threshold in stellar rotation rate above which rotation strongly prevents the vertical penetration of plumes and below which rotation has small effects. In addition to providing a possible explanation for the long-standing problem of lithium depletion in pre-main-sequence and main-sequence stars, the strength of our scenario is that its basic assumptions can be tested by future hydrodynamic simulations.

  1. Exploring ‘generative mechanisms’ of the antiretroviral adherence club intervention using the realist approach: a scoping review of research-based antiretroviral treatment adherence theories

    Directory of Open Access Journals (Sweden)

    Ferdinand C. Mukumbang

    2017-05-01

    Full Text Available Abstract Background Poor retention in care and non-adherence to antiretroviral therapy (ART continue to undermine the success of HIV treatment and care programmes across the world. There is a growing recognition that multifaceted interventions – application of two or more adherence-enhancing strategies – may be useful to improve ART adherence and retention in care among people living with HIV/AIDS. Empirical evidence shows that multifaceted interventions produce better results than interventions based on a singular perspective. Nevertheless, the bundle of mechanisms by which multifaceted interventions promote ART adherence are poorly understood. In this paper, we reviewed theories on ART adherence to identify candidate/potential mechanisms by which the adherence club intervention works. Methods We searched five electronic databases (PubMed, EBSCOhost, CINAHL, PsycARTICLES and Google Scholar using Medical Subject Headings (MeSH terms. A manual search of citations from the reference list of the studies identified from the electronic databases was also done. Twenty-six articles that adopted a theory-guided inquiry of antiretroviral adherence behaviour were included for the review. Eleven cognitive and behavioural theories underpinning these studies were explored. We examined each theory for possible ‘generative causality’ using the realist evaluation heuristic (Context-Mechanism-Outcome configuration, then, we selected candidate mechanisms thematically. Results We identified three major sets of theories: Information-Motivation-Behaviour, Social Action Theory and Health Behaviour Model, which explain ART adherence. Although they show potential in explaining adherence bebahiours, they fall short in explaining exactly why and how the various elements they outline combine to explain positive or negative outcomes. Candidate mechanisms indentified were motivation, self-efficacy, perceived social support, empowerment, perceived threat, perceived

  2. Exploring 'generative mechanisms' of the antiretroviral adherence club intervention using the realist approach: a scoping review of research-based antiretroviral treatment adherence theories.

    Science.gov (United States)

    Mukumbang, Ferdinand C; Van Belle, Sara; Marchal, Bruno; van Wyk, Brian

    2017-05-04

    Poor retention in care and non-adherence to antiretroviral therapy (ART) continue to undermine the success of HIV treatment and care programmes across the world. There is a growing recognition that multifaceted interventions - application of two or more adherence-enhancing strategies - may be useful to improve ART adherence and retention in care among people living with HIV/AIDS. Empirical evidence shows that multifaceted interventions produce better results than interventions based on a singular perspective. Nevertheless, the bundle of mechanisms by which multifaceted interventions promote ART adherence are poorly understood. In this paper, we reviewed theories on ART adherence to identify candidate/potential mechanisms by which the adherence club intervention works. We searched five electronic databases (PubMed, EBSCOhost, CINAHL, PsycARTICLES and Google Scholar) using Medical Subject Headings (MeSH) terms. A manual search of citations from the reference list of the studies identified from the electronic databases was also done. Twenty-six articles that adopted a theory-guided inquiry of antiretroviral adherence behaviour were included for the review. Eleven cognitive and behavioural theories underpinning these studies were explored. We examined each theory for possible 'generative causality' using the realist evaluation heuristic (Context-Mechanism-Outcome) configuration, then, we selected candidate mechanisms thematically. We identified three major sets of theories: Information-Motivation-Behaviour, Social Action Theory and Health Behaviour Model, which explain ART adherence. Although they show potential in explaining adherence bebahiours, they fall short in explaining exactly why and how the various elements they outline combine to explain positive or negative outcomes. Candidate mechanisms indentified were motivation, self-efficacy, perceived social support, empowerment, perceived threat, perceived benefits and perceived barriers. Although these candidate

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

    Science.gov (United States)

    Mitrano, Denise M.; Nowack, Bernd

    2017-02-01

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

  4. A realist review of mobile phone-based health interventions for non-communicable disease management in sub-Saharan Africa.

    Science.gov (United States)

    Opoku, Daniel; Stephani, Victor; Quentin, Wilm

    2017-02-06

    The prevalence of non-communicable diseases (NCDs) is increasing in sub-Saharan Africa. At the same time, the use of mobile phones is rising, expanding the opportunities for the implementation of mobile phone-based health (mHealth) interventions. This review aims to understand how, why, for whom, and in what circumstances mHealth interventions against NCDs improve treatment and care in sub-Saharan Africa. Four main databases (PubMed, Cochrane Library, Web of Science, and Google Scholar) and references of included articles were searched for studies reporting effects of mHealth interventions on patients with NCDs in sub-Saharan Africa. All studies published up until May 2015 were included in the review. Following a realist review approach, middle-range theories were identified and integrated into a Framework for Understanding the Contribution of mHealth Interventions to Improved Access to Care for patients with NCDs in sub-Saharan Africa. The main indicators of the framework consist of predisposing characteristics, needs, enabling resources, perceived usefulness, and perceived ease of use. Studies were analyzed in depth to populate the framework. The search identified 6137 titles for screening, of which 20 were retained for the realist synthesis. The contribution of mHealth interventions to improved treatment and care is that they facilitate (remote) access to previously unavailable (specialized) services. Three contextual factors (predisposing characteristics, needs, and enabling resources) influence if patients and providers believe that mHealth interventions are useful and easy to use. Only if they believe mHealth to be useful and easy to use, will mHealth ultimately contribute to improved access to care. The analysis of included studies showed that the most important predisposing characteristics are a positive attitude and a common language of communication. The most relevant needs are a high burden of disease and a lack of capacity of first-contact providers

  5. 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)

    Fritsch, Daniel S.; Raghavan, Suraj; Boxwala, Aziz; Earnhart, Jon; Tracton, Gregg; Cullip, Timothy; Chaney, Edward L.

    1997-01-01

    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

  6. How do eHealth Programs for Adolescents With Depression Work? A Realist Review of Persuasive System Design Components in Internet-Based Psychological Therapies

    Science.gov (United States)

    McGrath, Patrick J

    2017-01-01

    Background Major depressive disorders are common among adolescents and can impact all aspects of their daily life. Traditional therapies, cognitive behavioral therapy (CBT), and interpersonal psychotherapy (IPT) have been delivered face-to-face. However, Internet-based (online) delivery of these therapies is emerging as an option for adolescents. Internet-based CBT and IPT involve therapeutic content, interaction between the user and the system, and different technological features embedded into the online program (eg, multimedia). Studies of Internet-based CBT and IPT for adolescent depression differ on all three aspects, and variable, positive therapy effects have been reported. A better understanding of the treatment conditions that influence therapy outcomes is important to designing and evaluating these novel therapies. Objective Our aim was to examine the technological and program delivery features of Internet-based CBT and IPT for adolescent depression and to document their potential relation to treatment outcomes and program use. Methods We performed a realist synthesis. We started with an extensive search of published and gray literature. We included intervention studies that evaluated Internet-based CBT or IPT for adolescent depression. We included mixed-methods and qualitative studies, theoretical papers, and policy/implementation documents if they included a focus on how Internet-based psychological therapy is proposed to work for adolescents with depression/depressive symptoms. We used the Mixed-Methods Appraisal Tool to assess the methodological quality of studies. We used the Persuasive System Design (PSD) model as a framework for data extraction and analysis to examine how Internet-based CBT and IPT, as technology-based systems, influence the attitudes and behaviors of system users. PSD components described for the therapies were linked to reported outcomes using a cross-case comparison method and thematic synthesis. Results We identified 19

  7. How do eHealth Programs for Adolescents With Depression Work? A Realist Review of Persuasive System Design Components in Internet-Based Psychological Therapies.

    Science.gov (United States)

    Wozney, Lori; Huguet, Anna; Bennett, Kathryn; Radomski, Ashley D; Hartling, Lisa; Dyson, Michele; McGrath, Patrick J; Newton, Amanda S

    2017-08-09

    Major depressive disorders are common among adolescents and can impact all aspects of their daily life. Traditional therapies, cognitive behavioral therapy (CBT), and interpersonal psychotherapy (IPT) have been delivered face-to-face. However, Internet-based (online) delivery of these therapies is emerging as an option for adolescents. Internet-based CBT and IPT involve therapeutic content, interaction between the user and the system, and different technological features embedded into the online program (eg, multimedia). Studies of Internet-based CBT and IPT for adolescent depression differ on all three aspects, and variable, positive therapy effects have been reported. A better understanding of the treatment conditions that influence therapy outcomes is important to designing and evaluating these novel therapies. Our aim was to examine the technological and program delivery features of Internet-based CBT and IPT for adolescent depression and to document their potential relation to treatment outcomes and program use. We performed a realist synthesis. We started with an extensive search of published and gray literature. We included intervention studies that evaluated Internet-based CBT or IPT for adolescent depression. We included mixed-methods and qualitative studies, theoretical papers, and policy/implementation documents if they included a focus on how Internet-based psychological therapy is proposed to work for adolescents with depression/depressive symptoms. We used the Mixed-Methods Appraisal Tool to assess the methodological quality of studies. We used the Persuasive System Design (PSD) model as a framework for data extraction and analysis to examine how Internet-based CBT and IPT, as technology-based systems, influence the attitudes and behaviors of system users. PSD components described for the therapies were linked to reported outcomes using a cross-case comparison method and thematic synthesis. We identified 19 Internet-based CBT programs in 59 documents

  8. 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.

  9. Realistic Simulation of Rice Plant

    Directory of Open Access Journals (Sweden)

    Wei-long DING

    2011-09-01

    Full Text Available 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.

  10. 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...

  11. Kaonic hydrogen atoms with realistic potentials

    International Nuclear Information System (INIS)

    Yan, Y.; Poonsawat, W.; Khosonthongkee, K.; Kobdaj, C.; Suebka, P.

    2010-01-01

    Kaonic hydrogen is studied with various realistic potentials in an accurate numerical approach based on Sturmian functions. It is found that the mass difference between the K - p and K-bar 0 n channels has a considerable effect on theoretical results of the energy shift and decay width of kaonic hydrogen. On average, the theoretical result in the isospin symmetry limit is smaller by a factor of about 20% than the full result where the mass difference between the K - p and K-bar 0 n channels is properly treated. The theoretical results based on realistic local potentials, which reproduce well scattering data, are inconsistent with the recent measurement of the energy shift and decay width of the 1s kaonic hydrogen state by the DEAR Collaboration.

  12. Mathematical modeling in realistic mathematics education

    Science.gov (United States)

    Riyanto, B.; Zulkardi; Putri, R. I. I.; Darmawijoyo

    2017-12-01

    The purpose of this paper is to produce Mathematical modelling in Realistics Mathematics Education of Junior High School. This study used development research consisting of 3 stages, namely analysis, design and evaluation. The success criteria of this study were obtained in the form of local instruction theory for school mathematical modelling learning which was valid and practical for students. The data were analyzed using descriptive analysis method as follows: (1) walk through, analysis based on the expert comments in the expert review to get Hypothetical Learning Trajectory for valid mathematical modelling learning; (2) analyzing the results of the review in one to one and small group to gain practicality. Based on the expert validation and students’ opinion and answers, the obtained mathematical modeling problem in Realistics Mathematics Education was valid and practical.

  13. Realistic Visualization of Virtual Views

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    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...

  14. Assessment and realistic mathematics education

    NARCIS (Netherlands)

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

    1996-01-01

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

  15. True-to-Life? Realistic Fiction.

    Science.gov (United States)

    Jordan, Anne Devereaux

    1995-01-01

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

  16. Realist Criminology and its Discontents

    Directory of Open Access Journals (Sweden)

    Simon Winlow

    2016-09-01

    Full Text Available Critical criminology must move beyond twentieth-century empiricist and idealist paradigms because the concepts and research programmes influenced by these paradigms are falling into obsolescence. Roger Matthews’ recent work firmly advocates this position and helps to set the ball rolling. Here we argue that Matthews’ attempt to use critical realist thought to move Left Realism towards an advanced position can help to put criminology on a sound new footing. However, before this becomes possible numerous philosophical and theoretical issues must be ironed out. Most importantly, critical criminology must avoid political pragmatism and adopt a more critical stance towards consumer culture’s spectacle. A searching analysis of these issues suggests that, ultimately, criminology is weighed down with obsolete thinking to such an extent that to remain intellectually relevant it must move beyond both Left Realism and Critical Realism to construct a new ultra-realist position.

  17. Realist cinema as world cinema

    OpenAIRE

    Nagib, Lucia

    2017-01-01

    The idea that “realism” is the common denominator across the vast range of productions normally labelled as “world cinema” is widespread and seemly uncontroversial. Leaving aside oppositional binaries that define world cinema as the other of Hollywood or of classical cinema, this chapter will test the realist premise by locating it in the mode of production. It will define this mode as an ethics that engages filmmakers, at cinema’s creative peaks, with the physical and historical environment,...

  18. Realist Criminology and its Discontents

    OpenAIRE

    Simon Winlow; Steve Hall

    2016-01-01

    Critical criminology must move beyond twentieth-century empiricist and idealist paradigms because the concepts and research programmes influenced by these paradigms are falling into obsolescence. Roger Matthews’ recent work firmly advocates this position and helps to set the ball rolling. Here we argue that Matthews’ attempt to use critical realist thought to move Left Realism towards an advanced position can help to put criminology on a sound new footing. However, before this becomes possibl...

  19. 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....

  20. Realistic rhetoric and legal decision

    Directory of Open Access Journals (Sweden)

    João Maurício Adeodato

    2017-06-01

    Full Text Available The text aims to lay the foundations of a realistic rhetoric, from the descriptive perspective of how the legal decision actually takes place, without normative considerations. Aristotle's rhetorical idealism and its later prestige reduced rhetoric to the art of persuasion, eliminating important elements of sophistry, especially with regard to legal decision. It concludes with a rhetorical perspective of judicial activism in complex societies.

  1. Adaptive Automation Triggered by EEG-Based Mental Workload Index: A Passive Brain-Computer Interface Application in Realistic Air Traffic Control Environment

    Science.gov (United States)

    Aricò, Pietro; Borghini, Gianluca; Di Flumeri, Gianluca; Colosimo, Alfredo; Bonelli, Stefano; Golfetti, Alessia; Pozzi, Simone; Imbert, Jean-Paul; Granger, Géraud; Benhacene, Raïlane; Babiloni, Fabio

    2016-01-01

    Adaptive Automation (AA) is a promising approach to keep the task workload demand within appropriate levels in order to avoid both the under- and over-load conditions, hence enhancing the overall performance and safety of the human-machine system. The main issue on the use of AA is how to trigger the AA solutions without affecting the operative task. In this regard, passive Brain-Computer Interface (pBCI) systems are a good candidate to activate automation, since they are able to gather information about the covert behavior (e.g., mental workload) of a subject by analyzing its neurophysiological signals (i.e., brain activity), and without interfering with the ongoing operational activity. We proposed a pBCI system able to trigger AA solutions integrated in a realistic Air Traffic Management (ATM) research simulator developed and hosted at ENAC (École Nationale de l'Aviation Civile of Toulouse, France). Twelve Air Traffic Controller (ATCO) students have been involved in the experiment and they have been asked to perform ATM scenarios with and without the support of the AA solutions. Results demonstrated the effectiveness of the proposed pBCI system, since it enabled the AA mostly during the high-demanding conditions (i.e., overload situations) inducing a reduction of the mental workload under which the ATCOs were operating. On the contrary, as desired, the AA was not activated when workload level was under the threshold, to prevent too low demanding conditions that could bring the operator's workload level toward potentially dangerous conditions of underload. PMID:27833542

  2. Tuukka Kaidesoja on Critical Realist Transcendental Realism

    Directory of Open Access Journals (Sweden)

    Groff Ruth

    2015-09-01

    Full Text Available I argue that critical realists think pretty much what Tukka Kaidesoja says that he himself thinks, but also that Kaidesoja’s objections to the views that he attributes to critical realists are not persuasive.

  3. Realistic Features in Analysing the Effect of the Seismic Motion upon Localized Structures Considering Base Isolation Influence on Their Dynamic Behaviour

    Science.gov (United States)

    Apostol, Bogdan Felix; Florin Balan, Stefan; Ionescu, Constantin

    2017-12-01

    The effects of the earthquakes on buildings and the concept of seismic base isolation are investigated by using the model of the vibrating bar embedded at one end. The normal modes and the eigenfrequencies of the bar are highlighted and the amplification of the response due to the excitation of the normal modes (eigenmodes) is computed. The effect is much enhanced at resonance, for oscillating shocks which contain eigenfrequencies of the bar. Also, the response of two linearly joined bars with one end embedded is calculated. It is shown that for very different elastic properties the eigenfrequencies are due mainly to the “softer” bar. The effect of the base isolation in seismic structural engineering is assessed by formulating the model of coupled harmonic oscillators, as a simplified model for the structure building-foundation viewed as two coupled vibrating bars. The coupling decreases the lower eigenfrequencies of the structure and increases the higher ones. Similar amplification factors are derived for coupled oscillators at resonance with an oscillating shock.

  4. The Evidence-base for Using Ontologies and Semantic Integration Methodologies to Support Integrated Chronic Disease Management in Primary and Ambulatory Care: Realist Review. Contribution of the IMIA Primary Health Care Informatics WG.

    Science.gov (United States)

    Liyanage, H; Liaw, S-T; Kuziemsky, C; Terry, A L; Jones, S; Soler, J K; de Lusignan, S

    2013-01-01

    Most chronic diseases are managed in primary and ambulatory care. The chronic care model (CCM) suggests a wide range of community, technological, team and patient factors contribute to effective chronic disease management. Ontologies have the capability to enable formalised linkage of heterogeneous data sources as might be found across the elements of the CCM. To describe the evidence base for using ontologies and other semantic integration methods to support chronic disease management. We reviewed the evidence-base for the use of ontologies and other semantic integration methods within and across the elements of the CCM. We report them using a realist review describing the context in which the mechanism was applied, and any outcome measures. Most evidence was descriptive with an almost complete absence of empirical research and important gaps in the evidence-base. We found some use of ontologies and semantic integration methods for community support of the medical home and for care in the community. Ubiquitous information technology (IT) and other IT tools were deployed to support self-management support, use of shared registries, health behavioural models and knowledge discovery tools to improve delivery system design. Data quality issues restricted the use of clinical data; however there was an increased use of interoperable data and health system integration. Ontologies and semantic integration methods are emergent with limited evidence-base for their implementation. However, they have the potential to integrate the disparate community wide data sources to provide the information necessary for effective chronic disease management.

  5. Realistic microscopic level densities for spherical nuclei

    International Nuclear Information System (INIS)

    Cerf, N.

    1994-01-01

    Nuclear level densities play an important role in nuclear reactions such as the formation of the compound nucleus. We develop a microscopic calculation of the level density based on a combinatorial evaluation from a realistic single-particle level scheme. This calculation makes use of a fast Monte Carlo algorithm allowing us to consider large shell model spaces which could not be treated previously in combinatorial approaches. Since our model relies on a microscopic basis, it can be applied to exotic nuclei with more confidence than the commonly used semiphenomenological formuals. An exhaustive comparison of our predicted neutron s-wave resonance spacings with experimental data for a wide range of nuclei is presented

  6. Critical Realist Review: Exploring the Real, beyond the Empirical

    Science.gov (United States)

    Edgley, Alison; Stickley, Theodore; Timmons, Stephen; Meal, Andy

    2016-01-01

    This article defines the "critical realist review", a literature-based methodological approach to critical analysis of health care studies (or any discipline charged with social interventions) that is robust, insightful and essential for the complexities of twenty-first century evidence-based health and social care. We argue that this…

  7. Increasing Situational Awareness by Combining Realistic and Non-Realistic Rendering Techniques

    National Research Council Canada - National Science Library

    Summers, Valerie A; Normoyle, Aline; Flo, Robert

    2005-01-01

    .... The primary objective is to convert the abundance of information into concise knowledge. This paper proposes a method of combining realistic and non-realistic displays to increase display effectiveness, and hence improve situational awareness.

  8. Realistic Visualization of Virtual Views and Virtual Cinema

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Visualization is a new field of research which has received increasing attention in recent years. It is strictly related to the increased popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer...... generated characters, "virtual actors", in the motion picture production increases every day. While the most known computer graphics techniques have largely been adopted successfully in nowadays fictions, it still remains very challenging to implement virtual actors which would resemble, visually, human...... is then gaining consensus: the augmented actor. Fundamental concepts and examples of methods proposed for realistic view synthesis, based on the transfer of photorealism from reference photographs to novel views, will be presented. The application of methods for realistic image synthesis to virtual cinematography...

  9. Photo-Realistic Image Synthesis and Virtual Cinematography

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Synthesis is a new field of research that has received increasing attention in recent years. It is strictly related to the grown popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer generated...... characters, "virtual actors", in the motion picture production increases every day. While the most known computer graphics techniques have largely been adopted successfully in nowadays fictions, it still remains very challenging to implement virtual actors which would resemble, visually, human beings......: 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...

  10. The construction of context-mechanisms-outcomes in realistic evaluation.

    Science.gov (United States)

    Linsley, Paul; Howard, David; Owen, Sara

    2015-01-01

    To discuss the construction of context-mechanisms-outcomes (CMOs) developed as part of a realistic evaluation study of two aggression management training programmes. Realistic evaluation draws on theories and methods derived from the social sciences. It provides a distinctive account of the nature of programmes and how they work. Realistic evaluation is a form of evaluation that is driven by theory, and was based by Pawson and Tilley ( 1997 ) on the philosophy of critical realism. Critical realism is an important perspective in modern philosophy and social science, but it is largely absent in the field of healthcare research. This paper provides a critical discussion on the construction of CMOs as part of a realistic evaluation study. This paper draws on the personal experiences of the author in using realistic evaluation to evaluate training in aggression management. Realistic evaluation stresses four key linked concepts for explaining and understanding programmes: 'mechanism', 'context', 'outcome pattern' and 'context-mechanisms-outcomes (CMO) pattern configuration'. A CMO configuration is a proposition stating what it is about an initiative that works, for whom and in what circumstances. In this way, the effectiveness of the programme is understood, with an explanation of why the outcomes developed as they did and how the programme was able to react to underlying mechanisms and in what contexts. Therefore, a realistic evaluation researcher is not just inspecting outcomes to see if an initiative (implementation) works, but is analysing the outcomes to discover if the conjectured mechanism or context theories are confirmed. This analysis provides not only evidence of effectiveness, but also an explanation that helps to develop and improve the content and the targeting of future programmes. The development of CMOs requires a great deal of skill on the part of the researcher and requires a flexibility of approach when collecting and analysing the data and in

  11. Nuclear properties with realistic Hamiltonians through spectral distribution theory

    International Nuclear Information System (INIS)

    Vary, J.P.; Belehrad, R.; Dalton, B.J.

    1979-01-01

    Motivated by the need of non-perturbative methods for utilizing realistic nuclear Hamiltonians H, the authors use spectral distribution theory, based on calculated moments of H, to obtain specific bulk and valence properties of finite nuclei. The primary emphasis here is to present results for the binding energies of nuclei obtained with and without an assumed core. (Auth.)

  12. Place of a Realistic Teacher Education Pedagogy in an ICT ...

    African Journals Online (AJOL)

    This article is based on a study undertaken to examine the impact of introducing a realistic teacher education pedagogy (RTEP) oriented learning environment supported by ICT on distance teacher education in Uganda. It gives an overview of the quality, quantity and training of teachers in primary and secondary schools

  13. Realistic human muscle pressure for driving a mechanical lung

    Directory of Open Access Journals (Sweden)

    Fresnel Emeline

    2014-12-01

    Based on the equation of the respiratory movement and its electrical analogy, the respiratory muscle pressure was simulated with more consistency in regards of physiological evidences than those provided by the ASL 5000 software. The great variability in the so-produced inspiratory efforts can cover most of realistic patho-physiological conditions.

  14. A possible definition of a {\\it Realistic} Physics Theory

    OpenAIRE

    Gisin, Nicolas

    2014-01-01

    A definition of a {\\it Realistic} Physics Theory is proposed based on the idea that, at all time, the set of physical properties possessed (at that time) by a system should unequivocally determine the probabilities of outcomes of all possible measurements.

  15. Realistic generation cost of solar photovoltaic electricity

    International Nuclear Information System (INIS)

    Singh, Parm Pal; Singh, Sukhmeet

    2010-01-01

    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

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

    Science.gov (United States)

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

    2017-04-01

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

  17. Determination of Realistic Fire Scenarios in Spacecraft

    Science.gov (United States)

    Dietrich, Daniel L.; Ruff, Gary A.; Urban, David

    2013-01-01

    This paper expands on previous work that examined how large a fire a crew member could successfully survive and extinguish in the confines of a spacecraft. The hazards to the crew and equipment during an accidental fire include excessive pressure rise resulting in a catastrophic rupture of the vehicle skin, excessive temperatures that burn or incapacitate the crew (due to hyperthermia), carbon dioxide build-up or accumulation of other combustion products (e.g. carbon monoxide). The previous work introduced a simplified model that treated the fire primarily as a source of heat and combustion products and sink for oxygen prescribed (input to the model) based on terrestrial standards. The model further treated the spacecraft as a closed system with no capability to vent to the vacuum of space. The model in the present work extends this analysis to more realistically treat the pressure relief system(s) of the spacecraft, include more combustion products (e.g. HF) in the analysis and attempt to predict the fire spread and limiting fire size (based on knowledge of terrestrial fires and the known characteristics of microgravity fires) rather than prescribe them in the analysis. Including the characteristics of vehicle pressure relief systems has a dramatic mitigating effect by eliminating vehicle overpressure for all but very large fires and reducing average gas-phase temperatures.

  18. Evaluation of photovoltaic panel temperature in realistic scenarios

    International Nuclear Information System (INIS)

    Du, Yanping; Fell, Christopher J.; Duck, Benjamin; Chen, Dong; Liffman, Kurt; Zhang, Yinan; Gu, Min; Zhu, Yonggang

    2016-01-01

    Highlights: • The developed realistic model captures more reasonably the thermal response and hysteresis effects. • The predicted panel temperature is as high as 60 °C under a solar irradiance of 1000 W/m 2 in no-wind weather. • In realistic scenarios, the thermal response normally takes 50–250 s. • The actual heating effect may cause a photoelectric efficiency drop of 2.9–9.0%. - Abstract: Photovoltaic (PV) panel temperature was evaluated by developing theoretical models that are feasible to be used in realistic scenarios. Effects of solar irradiance, wind speed and ambient temperature on the PV panel temperature were studied. The parametric study shows significant influence of solar irradiance and wind speed on the PV panel temperature. With an increase of ambient temperature, the temperature rise of solar cells is reduced. The characteristics of panel temperature in realistic scenarios were analyzed. In steady weather conditions, the thermal response time of a solar cell with a Si thickness of 100–500 μm is around 50–250 s. While in realistic scenarios, the panel temperature variation in a day is different from that in steady weather conditions due to the effect of thermal hysteresis. The heating effect on the photovoltaic efficiency was assessed based on real-time temperature measurement of solar cells in realistic weather conditions. For solar cells with a temperature coefficient in the range of −0.21%∼−0.50%, the current field tests indicated an approximate efficiency loss between 2.9% and 9.0%.

  19. 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.

  20. 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

  1. Results of recent calculations using realistic potentials

    International Nuclear Information System (INIS)

    Friar, J.L.

    1987-01-01

    Results of recent calculations for the triton using realistic potentials with strong tensor forces are reviewed, with an emphasis on progress made using the many different calculational schemes. Several test problems are suggested. 49 refs., 5 figs

  2. The development of social-realistic «tropes» in the screenwriting of the early 1960s: based on Gennady Shpalikov’s screenplay «Berth»

    Directory of Open Access Journals (Sweden)

    Artemyeva E.A.

    2017-06-01

    Full Text Available the paper focuses on the development of the social-realistic tradition in the culture of the early 1960s. Special attention is paid to the first full-length feature Gennady Shpalikov’s screenplay «Berth», which is an example of the development and the change of social-realistic «tropes» in the screenwriting of «Ottepel / the Thaw»: «a positive hero», «big family» and «war». The author concludes that these fundamental «tropes» define all Shpalikov’s work, the screenwriting and the poetry.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. Development of KAERI LBLOCA realistic evaluation model

    International Nuclear Information System (INIS)

    Lee, W.J.; Lee, Y.J.; Chung, B.D.; Lee, S.Y.

    1994-01-01

    A realistic evaluation model (REM) for LBLOCA licensing calculation is developed and proposed for application to pressurized light water reactors. The developmental aim of the KAERI-REM is to provide a systematic methodology that is simple in structure and to use and built upon sound logical reasoning, for improving the code capability to realistically describe the LBLOCA phenomena and for evaluating the associated uncertainties. The method strives to be faithful to the intention of being best-estimate, that is, the method aims to evaluate the best-estimate values and the associated uncertainties while complying to the requirements in the ECCS regulations. (author)

  8. Resonant scattering by realistic impurities in graphene.

    Science.gov (United States)

    Wehling, T O; Yuan, S; Lichtenstein, A I; Geim, A K; Katsnelson, M I

    2010-07-30

    We develop a first-principles theory of resonant impurities in graphene and show that a broad range of typical realistic impurities leads to the characteristic sublinear dependence of the conductivity on the carrier concentration. By means of density functional calculations various organic groups as well as adatoms such as H absorbed to graphene are shown to create midgap states within ±0.03  eV around the neutrality point. A low energy tight-binding description is mapped out. Boltzmann transport theory as well as a numerically exact Kubo formula approach yield the conductivity of graphene contaminated with these realistic impurities in accordance with recent experiments.

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

    Science.gov (United States)

    O'Connor, Barbara

    2010-01-01

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

  10. Face to Face: From Real Humans to Realistic Facial Animation

    OpenAIRE

    Haber, Jörg; Kähler, Kolja; Albrecht, Irene; Yamauchi, Hitoshi; Seidel, Hans-Peter

    2001-01-01

    We present a system for photo-realistic facial modeling and animation, which includes several tools that facilitate necessary tasks such as mesh processing, texture registration, and assembling of facial components. The resulting head model reflects the anatomical structure of the human head including skull, skin, and muscles. Semiautomatic generation of high-quality models from scan data for physics-based animation becomes possible with little effort. A state-o...

  11. Faculty Development for Educators: A Realist Evaluation

    Science.gov (United States)

    Sorinola, Olanrewaju O.; Thistlethwaite, Jill; Davies, David; Peile, Ed

    2015-01-01

    The effectiveness of faculty development (FD) activities for educators in UK medical schools remains underexplored. This study used a realist approach to evaluate FD and to test the hypothesis that motivation, engagement and perception are key mechanisms of effective FD activities. The authors observed and interviewed 33 course participants at one…

  12. Realistic searches on stretched exponential networks

    Indian Academy of Sciences (India)

    Vol. 71, No. 2. — journal of. August 2008 physics pp. 313–317. Realistic searches on stretched exponential networks. PARONGAMA SEN. Department of Physics, University of Calcutta, 92 Acharya Prafulla Chandra Road,. Kolkata 700 009, India .... [4] S Milgram, Psychology Today 1, 60 (1967). J Travers and S Milgram, ...

  13. Realistic searches on stretched exponential networks

    Indian Academy of Sciences (India)

    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.

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

    Science.gov (United States)

    Madsen, Jane M.; Wickersham, Elaine B.

    1980-01-01

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

  15. Realistic Approach for Phasor Measurement Unit Placement

    DEFF Research Database (Denmark)

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

    2015-01-01

    This paper presents a realistic cost-effectivemodel for optimal placement of phasor measurement units (PMUs) for complete observability of a power system considering practical cost implications. The proposed model considers hidden or otherwise unaccounted practical costs involved in PMU installat...

  16. Spatial Visualization by Realistic 3D Views

    Science.gov (United States)

    Yue, Jianping

    2008-01-01

    In this study, the popular Purdue Spatial Visualization Test-Visualization by Rotations (PSVT-R) in isometric drawings was recreated with CAD software that allows 3D solid modeling and rendering to provide more realistic pictorial views. Both the original and the modified PSVT-R tests were given to students and their scores on the two tests were…

  17. Interferometric data modelling: issues in realistic data generation

    International Nuclear Information System (INIS)

    Mukherjee, Soma

    2004-01-01

    This study describes algorithms developed for modelling interferometric noise in a realistic manner, i.e. incorporating non-stationarity that can be seen in the data from the present generation of interferometers. The noise model is based on individual component models (ICM) with the application of auto regressive moving average (ARMA) models. The data obtained from the model are vindicated by standard statistical tests, e.g. the KS test and Akaike minimum criterion. The results indicate a very good fit. The advantage of using ARMA for ICMs is that the model parameters can be controlled and hence injection and efficiency studies can be conducted in a more controlled environment. This realistic non-stationary noise generator is intended to be integrated within the data monitoring tool framework

  18. Resonance and continuum Gamow shell model with realistic nuclear forces

    Science.gov (United States)

    Sun, Z. H.; Wu, Q.; Zhao, Z. H.; Hu, B. S.; Dai, S. J.; Xu, F. R.

    2017-06-01

    Starting from realistic nuclear forces, we have developed a core Gamow shell model which can describe resonance and continuum properties of loosely-bound or unbound nuclear systems. To describe properly resonance and continuum, the Berggren representation has been employed, which treats bound, resonant and continuum states on equal footing in a complex-momentum (complex-k) plane. To derive the model-space effective interaction based on realistic forces, the full Q ˆ -box folded-diagram renormalization has been, for the first time, extended to the nondegenerate complex-k space. The CD-Bonn potential is softened by using the Vlow-k method. Choosing 16O as the inert core, we have calculated sd-shell neutron-rich oxygen isotopes, giving good descriptions of both bound and resonant states. The isotopes 25,26O are calculated to be resonant even in their ground states.

  19. How to estimate realistic energy savings in Energy Performance Certificates

    DEFF Research Database (Denmark)

    Wittchen, Kim Bjarne; Altmann, Nagmeh; Berecová, Monika

    to suggested building energy upgrading in the EPC will also deviate from the actual achieved energy savings. Adjusting input boundary condition to the actual values, will often result in realistic (comparable with measured energy consumption) calculated energy demands. This even happens in simple, quasi...... renovation. In this context, it is important to distinguish between benchmarking/certification and calculation of expected energy demand based on realistic input data.......Given the fact that most MS use fixed or other kinds of default values as boundary condition input for energy performance calculations, it is not surprising that the calculated energy performance differs from the measured energy consumption. As a consequence, the calculated energy savings due...

  20. Regularization techniques in realistic Laplacian computation.

    Science.gov (United States)

    Bortel, Radoslav; Sovka, Pavel

    2007-11-01

    This paper explores regularization options for the ill-posed spline coefficient equations in the realistic Laplacian computation. We investigate the use of the Tikhonov regularization, truncated singular value decomposition, and the so-called lambda-correction with the regularization parameter chosen by the L-curve, generalized cross-validation, quasi-optimality, and the discrepancy principle criteria. The provided range of regularization techniques is much wider than in the previous works. The improvement of the realistic Laplacian is investigated by simulations on the three-shell spherical head model. The conclusion is that the best performance is provided by the combination of the Tikhonov regularization and the generalized cross-validation criterion-a combination that has never been suggested for this task before.

  1. Behaviorly realistic simulations of stock market traders with a soul

    Science.gov (United States)

    Solomon, Sorin

    1999-09-01

    The price fluctuations of the stocks in the financial markets are the result of the individual operations by many individual investors. However for many decades the financial theory did not use directly this “microscopic representation” of the markets. The main difficulties preventing this approach were solved recently with the advent of modern computer technology: - massive detailed data on the individual market operations became available; - “microscopic simulations” of the stock markets in terms of their individual participating agents allow very realistic treatment of the problem. By taking advantage of the modern computer processing and simulation techniques, we are now able to confront real market data with the results of simulating “microscopic” realistic models of the markets. These models have the potential to include and study the effects on the market of any desired feature in the investors behavior: departures from rationality, herding effects, heterogeneous investor-specific trading strategies. We propose to use the comparison of computer simulations of microscopic models with the actual market data in order to validate and enhance the knowledge on the financial behavior of individuals. Moreover we hope to explain, understand (and may be predict and control) macroscopic market dynamical features (e.g., cycles of booms and crashes, investors wealth distribution, market returns probability distribution etc.) based on realistic models using this knowledge.

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

    Science.gov (United States)

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

    2010-06-01

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

  3. An anatomically realistic temperature phantom for radiofrequency heating measurements

    Science.gov (United States)

    Graedel, Nadine N.; Polimeni, Jonathan R.; Guerin, Bastien; Gagoski, Borjan; Wald, Lawrence L.

    2014-01-01

    Purpose An anthropomorphic phantom with realistic electrical properties allows for a more accurate reproduction of tissue current patterns during excitation. A temperature map can then probe the worst-case heating expected in the un-perfused case. We describe an anatomically realistic human head phantom that allows rapid 3D temperature mapping at 7 T. Methods The phantom was based on hand-labeled anatomical imaging data and consists of four compartments matching the corresponding human tissues in geometry and electrical properties. The increases in temperature resulting from radiofrequency excitation were measured with MR thermometry using a temperature sensitive contrast agent (TmDOTMA−) validated by direct fiber optic temperature measurements. Results Acquisition of 3D temperature maps of the full phantom with a temperature accuracy better than 0.1°C was achieved with an isotropic resolution of 5 mm and acquisition times of 2–4 minutes. Conclusion Our results demonstrate the feasibility of constructing anatomically realistic phantoms with complex geometries incorporating the ability to measure accurate temperature maps in the phantom. The anthropomorphic temperature phantom is expected to provide a useful tool for the evaluation of the heating effects of both conventional and parallel transmit pulses and help validate electromagnetic and temperature simulations. PMID:24549755

  4. 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.

  5. 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

  6. MANAJEMEN LABA: PERILAKU MANAJEMEN OPPORTUNISTIC ATAU REALISTIC ?

    Directory of Open Access Journals (Sweden)

    I Nyoman Wijana Asmara Putra

    2011-01-01

    Full Text Available Earnings management is a still attractive issue. It is often associatedwith negative behavior conducted by management for its own interest. In fact,it also has different side to be examined. There is another motivation to do so,such as to improve the company’s operation. This literature study aims toreview management motivation of doing earnings management, whetheropportunistic or realistic. What conflict that earnings management brings,what pro and cons about it, what would happen if earnings is not managed,whether the company would be better off or worse off.

  7. 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

  8. Turbulence studies in tokamak boundary plasmas with realistic divertor geometry

    International Nuclear Information System (INIS)

    Xu, X.Q.; Cohen, R.H.; Por, G.D. ter; Rognlien, T.D.; Ryutov, D.D.; Myra, J.R.; D'Ippolito, D.A.; Moyer, R.; Groebner, R.J.

    1999-01-01

    Results are presented from the 3D nonlocal electromagnetic turbulence code BOUT and the linearized shooting code BAL for studies of turbulence in tokamak boundary plasmas and its relationship to the L-H transition, in a realistic divertor plasma geometry. The key results include: (1) the identification of the dominant resistive X-point mode in divertor geometry and (2) turbulence suppression in the L-H transition by shear in the E x B drift speed, ion diamagnetism and finite polarization. Based on the simulation results, a parameterization of the transport is given that includes the dependence on the relevant physical parameters. (author)

  9. Turbulence studies in tokamak boundary plasmas with realistic divertor geometry

    International Nuclear Information System (INIS)

    Xu, X.Q.; Cohen, R.H.; Porter, G.D.; Rognlien, T.; Ryutov, D.D.; Myra, J.R.; D'Ippolito, D.A.; Moyer, R.; Groebner, R.J.

    2001-01-01

    Results are presented from the 3D nonlocal electromagnetic turbulence code BOUT and the linearized shooting code BAL for studies of turbulence in tokamak boundary plasmas and its relationship to the L-H transition, in a realistic divertor plasma geometry. The key results include: (1) the identification of the dominant resistive X-point mode in divertor geometry and (2) turbulence suppression in the L-H transition by shear in the ExB drift speed, ion diamagnetism and nite polarization. Based on the simulation results, a parameterization of the transport is given that includes the dependence on the relevant physical parameters. (author)

  10. TMS modeling toolbox for realistic simulation.

    Science.gov (United States)

    Cho, Young Sun; Suh, Hyun Sang; Lee, Won Hee; Kim, Tae-Seong

    2010-01-01

    Transcranial magnetic stimulation (TMS) is a technique for brain stimulation using rapidly changing magnetic fields generated by coils. It has been established as an effective stimulation technique to treat patients suffering from damaged brain functions. Although TMS is known to be painless and noninvasive, it can also be harmful to the brain by incorrect focusing and excessive stimulation which might result in seizure. Therefore there is ongoing research effort to elucidate and better understand the effect and mechanism of TMS. Lately Boundary element method (BEM) and Finite element method (FEM) have been used to simulate the electromagnetic phenomenon of TMS. However, there is a lack of general tools to generate the models of TMS due to some difficulties in realistic modeling of the human head and TMS coils. In this study, we have developed a toolbox through which one can generate high-resolution FE TMS models. The toolbox allows creating FE models of the head with isotropic and anisotropic electrical conductivities in five different tissues of the head and the coils in 3D. The generated TMS model is importable to FE software packages such as ANSYS for further and efficient electromagnetic analysis. We present a set of demonstrative results of realistic simulation of TMS with our toolbox.

  11. Fabrication of a set of realistic torso phantoms for calibration of transuranic nuclide lung counting facilities

    International Nuclear Information System (INIS)

    Griffith, R.V.; Anderson, A.L.; Sundbeck, C.W.; Alderson, S.W.

    1983-01-01

    A set of 16 tissue equivalent torso phantoms has been fabricated for use by major laboratories involved in counting transuranic nuclides in the lung. These phantoms, which have bone equivalent plastic rib cages, duplicate the performance of the DOE Realistic Phantom set. The new phantoms (and their successors) provide the user laboratories with a highly realistic calibration tool. Moreover, use of these phantoms will allow participating laboratories to intercompare calibration information, both on formal and informal bases. 3 refs., 2 figs

  12. High-definition displays for realistic simulator and trainer systems

    Science.gov (United States)

    Daniels, Reginald; Hopper, Darrel G.; Beyer, Steve; Peppler, Philipp W.

    1998-09-01

    Current flight simulators and trainers do not provide acceptable levels of visual display performance (performance that would allow ground based trainers to economically replace aircraft flying training) for many air-to-air and air-to- ground training scenarios. Ground training for pilots could be made significantly more realistic, allowing the ground-based curricula to be enlarged. The enhanced ground based training could then more readily augment actual aircraft flying (training) time. This paper presents the technology need and opportunity to create a new class of immersive simulator- trainer systems having some 210 million pixels characterized especially by a 20-20 visual acuity synthetic vision system having some 150 million pixels. The same new display technology base is needed for planned crew stations for uninhabited combat air vehicles (UCAV), advanced aircraft cockpits and mission crewstations, and for the space plane.

  13. Building Realistic Mobility Models for Mobile Ad Hoc Networks

    Directory of Open Access Journals (Sweden)

    Adrian Pullin

    2018-04-01

    Full Text Available A mobile ad hoc network (MANET is a self-configuring wireless network in which each node could act as a router, as well as a data source or sink. Its application areas include battlefields and vehicular and disaster areas. Many techniques applied to infrastructure-based networks are less effective in MANETs, with routing being a particular challenge. This paper presents a rigorous study into simulation techniques for evaluating routing solutions for MANETs with the aim of producing more realistic simulation models and thereby, more accurate protocol evaluations. MANET simulations require models that reflect the world in which the MANET is to operate. Much of the published research uses movement models, such as the random waypoint (RWP model, with arbitrary world sizes and node counts. This paper presents a technique for developing more realistic simulation models to test and evaluate MANET protocols. The technique is animation, which is applied to a realistic scenario to produce a model that accurately reflects the size and shape of the world, node count, movement patterns, and time period over which the MANET may operate. The animation technique has been used to develop a battlefield model based on established military tactics. Trace data has been used to build a model of maritime movements in the Irish Sea. Similar world models have been built using the random waypoint movement model for comparison. All models have been built using the ns-2 simulator. These models have been used to compare the performance of three routing protocols: dynamic source routing (DSR, destination-sequenced distance-vector routing (DSDV, and ad hoc n-demand distance vector routing (AODV. The findings reveal that protocol performance is dependent on the model used. In particular, it is shown that RWP models do not reflect the performance of these protocols under realistic circumstances, and protocol selection is subject to the scenario to which it is applied. To

  14. Realistic edge field model code REFC for designing and study of isochronous cyclotron

    International Nuclear Information System (INIS)

    Ismail, M.

    1989-01-01

    The focussing properties and the requirements for isochronism in cyclotron magnet configuration are well-known in hard edge field model. The fact that they quite often change considerably in realistic field can be attributed mainly to the influence of the edge field. A solution to this problem requires a field model which allows a simple construction of equilibrium orbit and yield simple formulae. This can be achieved by using a fitted realistic edge field (Hudson et al 1975) in the region of the pole edge and such a field model is therefore called a realistic edge field model. A code REFC based on realistic edge field model has been developed to design the cyclotron sectors and the code FIELDER has been used to study the beam properties. In this report REFC code has been described along with some relevant explaination of the FIELDER code. (author). 11 refs., 6 figs

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

    Science.gov (United States)

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

    2016-03-01

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

  16. 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

  17. 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.

  18. Realistic Simulations of Coronagraphic Observations with WFIRST

    Science.gov (United States)

    Rizzo, Maxime; Zimmerman, Neil; Roberge, Aki; Lincowski, Andrew; Arney, Giada; Stark, Chris; Jansen, Tiffany; Turnbull, Margaret; WFIRST Science Investigation Team (Turnbull)

    2018-01-01

    We present a framework to simulate observing scenarios with the WFIRST Coronagraphic Instrument (CGI). The Coronagraph and Rapid Imaging Spectrograph in Python (crispy) is an open-source package that can be used to create CGI data products for analysis and development of post-processing routines. The software convolves time-varying coronagraphic PSFs with realistic astrophysical scenes which contain a planetary architecture, a consistent dust structure, and a background field composed of stars and galaxies. The focal plane can be read out by a WFIRST electron-multiplying CCD model directly, or passed through a WFIRST integral field spectrograph model first. Several elementary post-processing routines are provided as part of the package.

  19. Presupernova neutrinos: realistic emissivities from stellar evolution

    Science.gov (United States)

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

    2017-01-01

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

  20. E. H. Carr: En kompleks realist

    DEFF Research Database (Denmark)

    Meyn, Carina Ann

    2008-01-01

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

  1. Level density from realistic nuclear potentials

    International Nuclear Information System (INIS)

    Calboreanu, A.

    2006-01-01

    Nuclear level density of some nuclei is calculated using a realistic set of single particle states (sps). These states are derived from the parameterization of nuclear potentials that describe the observed sps over a large number of nuclei. This approach has the advantage that one can infer level density for nuclei that are inaccessible for a direct study, but are very important in astrophysical processes such as those close to the drip lines. Level densities at high excitation energies are very sensitive to the actual set of sps. The fact that the sps spectrum is finite has extraordinary consequences upon nuclear reaction yields due to the leveling-off of the level density at extremely high excitation energies wrongly attributed so far to other nuclear effects. Single-particle level density parameter a parameter is extracted by fitting the calculated densities to the standard Bethe formula

  2. 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.

  3. A conceptual ENSO model under realistic noise forcing

    Directory of Open Access Journals (Sweden)

    J. Saynisch

    2006-01-01

    Full Text Available We investigated the influence of atmospheric noise on the generation of interannual El Niño variability. Therefore, we perturbed a conceptual ENSO delay model with surrogate windstress data generated from tropical windspeed measurements. The effect of the additional stochastic forcing was studied for various parameter sets including periodic and chaotic regimes. The evaluation was based on a spectrum and amplitude-period relation comparison between model and measured sea surface temperature data. The additional forcing turned out to increase the variability of the model output in general. The noise-free model was unable to reproduce the observed spectral bandwidth for any choice of parameters. On the contrary, the stochastically forced model is capable of producing a realistic spectrum. The weakly nonlinear regimes of the model exhibit a proportional relation between amplitude and period matching the relation derived from measurement data. The chaotic regime, however, shows an inversely proportional relation. A stability analysis of the different regimes revealed that the spectra of the weakly nonlinear regimes are robust against slight parameter changes representing disregarded physical mechanisms, whereas the chaotic regime exhibits a very unstable realistic spectrum. We conclude that the model including stochastic forcing in a parameter range of moderate nonlinearity best matches the real conditions. This suggests that atmospheric noise plays an important role in the coupled tropical pacific ocean-atmosphere system.

  4. 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 (pinternal validity of the rating scales were good. Face validity was excellent, and both groups agreed that the endoscopy 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.

  5. Development of realistic thermal hydraulic system analysis code

    International Nuclear Information System (INIS)

    Lee, Won Jae; Chung, B. D; Kim, K. D.

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others

  6. Development of realistic thermal hydraulic system analysis code

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jae; Chung, B. D; Kim, K. D. [and others

    2002-05-01

    The realistic safety analysis system is essential for nuclear safety research, advanced reactor development, safety analysis in nuclear industry and 'in-house' plant design capability development. In this project, we have developed a best-estimate multi-dimensional thermal-hydraulic system code, MARS, which is based on the integrated version of the RELAP5 and COBRA-TF codes. To improve the realistic analysis capability, we have improved the models for multi-dimensional two-phase flow phenomena and for advanced two-phase flow modeling. In addition, the GUI (Graphic User Interface) feature were developed to enhance the user's convenience. To develop the coupled analysis capability, the MARS code were linked with the three-dimensional reactor kinetics code (MASTER), the core thermal analysis code (COBRA-III/CP), and the best-estimate containment analysis code (CONTEMPT), resulting in MARS/MASTER/COBRA/CONTEMPT. Currently, the MARS code system has been distributed to 18 domestic organizations, including research, industrial, regulatory organizations and universities. The MARS has been being widely used for the safety research of existing PWRs, advanced PWR, CANDU and research reactor, the pre-test analysis of TH experiments, and others.

  7. Realistically Rendering SoC Traffic Patterns with Interrupt Awareness

    DEFF Research Database (Denmark)

    Angiolini, Frederico; Mahadevan, Sharkar; Madsen, Jan

    2005-01-01

    In Multi-Processor System-on-Chip (MPSoC) design stages, accurate modeling of IP behaviour is crucial to analyze interconnect effectiveness. However, parallel development of components may cause IP core models to be still unavailable when tuning communication performance. Traditionally, synthetic...... to generate realistic test traffic. This paper presents a selection of applications using interrupt-based synchronization; a reference methodology to split such applications in execution subflows and to adjust the overall execution stream based upon hardware events; a reactive simulation device capable...... of correctly replicating such software behaviours in the MPSoC design phase. Additionally, we validate the proposed concept by showing cycle-accurate reproduction of a previously traced application flow....

  8. Challenges and solutions for realistic room simulation

    Science.gov (United States)

    Begault, Durand R.

    2002-05-01

    Virtual room acoustic simulation (auralization) techniques have traditionally focused on answering questions related to speech intelligibility or musical quality, typically in large volumetric spaces. More recently, auralization techniques have been found to be important for the externalization of headphone-reproduced virtual acoustic images. Although externalization can be accomplished using a minimal simulation, data indicate that realistic auralizations need to be responsive to head motion cues for accurate localization. Computational demands increase when providing for the simulation of coupled spaces, small rooms lacking meaningful reverberant decays, or reflective surfaces in outdoor environments. Auditory threshold data for both early reflections and late reverberant energy levels indicate that much of the information captured in acoustical measurements is inaudible, minimizing the intensive computational requirements of real-time auralization systems. Results are presented for early reflection thresholds as a function of azimuth angle, arrival time, and sound-source type, and reverberation thresholds as a function of reverberation time and level within 250-Hz-2-kHz octave bands. Good agreement is found between data obtained in virtual room simulations and those obtained in real rooms, allowing a strategy for minimizing computational requirements of real-time auralization systems.

  9. Quantifying introgression risk with realistic population genetics.

    Science.gov (United States)

    Ghosh, Atiyo; Meirmans, Patrick G; Haccou, Patsy

    2012-12-07

    Introgression is the permanent incorporation of genes from the genome of one population into another. This can have severe consequences, such as extinction of endemic species, or the spread of transgenes. Quantification of the risk of introgression is an important component of genetically modified crop regulation. Most theoretical introgression studies aimed at such quantification disregard one or more of the most important factors concerning introgression: realistic genetical mechanisms, repeated invasions and stochasticity. In addition, the use of linkage as a risk mitigation strategy has not been studied properly yet with genetic introgression models. Current genetic introgression studies fail to take repeated invasions and demographic stochasticity into account properly, and use incorrect measures of introgression risk that can be manipulated by arbitrary choices. In this study, we present proper methods for risk quantification that overcome these difficulties. We generalize a probabilistic risk measure, the so-called hazard rate of introgression, for application to introgression models with complex genetics and small natural population sizes. We illustrate the method by studying the effects of linkage and recombination on transgene introgression risk at different population sizes.

  10. Cerebral blood flow simulations in realistic geometries

    Directory of Open Access Journals (Sweden)

    Szopos Marcela

    2012-04-01

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

  11. 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.

  12. On the realistic validation of photometric redshifts

    Science.gov (United States)

    Beck, R.; Lin, C.-A.; Ishida, E. E. O.; Gieseke, F.; de Souza, R. S.; Costa-Duarte, M. V.; Hattab, M. W.; Krone-Martins, A.

    2017-07-01

    Two of the main problems encountered in the development and accurate validation of photometric redshift (photo-z) techniques are the lack of spectroscopic coverage in the feature space (e.g. colours and magnitudes) and the mismatch between the photometric error distributions associated with the spectroscopic and photometric samples. Although these issues are well known, there is currently no standard benchmark allowing a quantitative analysis of their impact on the final photo-z estimation. In this work, we present two galaxy catalogues, Teddy and Happy, built to enable a more demanding and realistic test of photo-z methods. Using photometry from the Sloan Digital Sky Survey and spectroscopy from a collection of sources, we constructed data sets that mimic the biases between the underlying probability distribution of the real spectroscopic and photometric sample. We demonstrate the potential of these catalogues by submitting them to the scrutiny of different photo-z methods, including machine learning (ML) and template fitting approaches. Beyond the expected bad results from most ML algorithms for cases with missing coverage in the feature space, we were able to recognize the superiority of global models in the same situation and the general failure across all types of methods when incomplete coverage is convoluted with the presence of photometric errors - a data situation which photo-z methods were not trained to deal with up to now and which must be addressed by future large-scale surveys. Our catalogues represent the first controlled environment allowing a straightforward implementation of such tests. The data are publicly available within the COINtoolbox (https://github.com/COINtoolbox/photoz_catalogues).

  13. Breaking with fun, educational and realistic learning games

    DEFF Research Database (Denmark)

    Duus Henriksen, Thomas

    2009-01-01

    are commonly conceived as means for staging learning processes, and that thinking learning games so has an inhibiting effect in regard to creating learning processes. The paper draws upon a qualitative study of participants' experiences with ‘the EIS Simulation', which is a computer-based learning game......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...... 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...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    We explore means of designing and evaluating initial visualization ideas, with concrete and realistic data in cases where data is not readily available. Our approach is useful in exploring new domains and avenues for visualization, and contrasts other visualization work, which typically operate...... under the assumption that data has already been collected, and is ready to be visualized. We argue that it is sensible to understand data requirements and evaluate the potential value of visualization before devising means of automatic data collection. We base our exploration on three cases selected...... the design case and problem, the manner in which we collected data, and the findings obtained from evaluations. Afterwards, we describe four factors of our data collection approach, and discuss potential outcomes from it....

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

    KAUST Repository

    Parshad, Rana

    2013-05-19

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

  16. 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...... cancellation, since this technique does not increase the diversity order of the desired signal. In addition, failures or malfunction of the cellular infrastructure are analysed. Among different types of failures evaluated, results show that failures spanning over large geographical areas can have a significant...

  17. Realistic nurse-led policy implementation, optimization and evaluation: novel methodological exemplar.

    Science.gov (United States)

    Noyes, Jane; Lewis, Mary; Bennett, Virginia; Widdas, David; Brombley, Karen

    2014-01-01

    To report the first large-scale realistic nurse-led implementation, optimization and evaluation of a complex children's continuing-care policy. Health policies are increasingly complex, involve multiple Government departments and frequently fail to translate into better patient outcomes. Realist methods have not yet been adapted for policy implementation. Research methodology - Evaluation using theory-based realist methods for policy implementation. An expert group developed the policy and supporting tools. Implementation and evaluation design integrated diffusion of innovation theory with multiple case study and adapted realist principles. Practitioners in 12 English sites worked with Consultant Nurse implementers to manipulate the programme theory and logic of new decision-support tools and care pathway to optimize local implementation. Methods included key-stakeholder interviews, developing practical diffusion of innovation processes using key-opinion leaders and active facilitation strategies and a mini-community of practice. New and existing processes and outcomes were compared for 137 children during 2007-2008. Realist principles were successfully adapted to a shorter policy implementation and evaluation time frame. Important new implementation success factors included facilitated implementation that enabled 'real-time' manipulation of programme logic and local context to best-fit evolving theories of what worked; using local experiential opinion to change supporting tools to more realistically align with local context and what worked; and having sufficient existing local infrastructure to support implementation. Ten mechanisms explained implementation success and differences in outcomes between new and existing processes. Realistic policy implementation methods have advantages over top-down approaches, especially where clinical expertise is low and unlikely to diffuse innovations 'naturally' without facilitated implementation and local optimization. © 2013

  18. Using Screenwriting Techniques To Create Realistic and Ethical Role Plays.

    Science.gov (United States)

    Shepard, David S.

    2002-01-01

    Describes an innovative training strategy that can be used to make role plays a more realistic learning experience for counseling students. The method involves using techniques that screenwriters use to create believable characters and applying these techniques to help students create realistic role-play clients. This approach also resolves some…

  19. An Exploratory Study of the Relative Effectiveness of Realistic and Non-Realistic Color in Visual Instructional Materials.

    Science.gov (United States)

    Berry, Louis H.

    In order to compare the instructional effectiveness of realistic and non-realistic color cueing on visualized instruction, an instructional unit on the human heart, using slides and an audiotape, was presented to 244 college students. Four treatment groups received the same oral presentation, with the addition of different types of visual…

  20. Educational Change in Singapore and Its "Tinkering" around the Edges: A Critical Realist Perspective

    Science.gov (United States)

    De Souza, Denise E.

    2018-01-01

    This article re-examines the contents of Singapore's Thinking Schools Learning Nation (TSLN) and Teach Less Learn More (TLLM) educational initiatives, introduced and implemented to promote change and to prepare Singaporeans for a twenty-first century knowledge-based economy. Adopting a critical realist perspective that enables investigations into…

  1. Dimensioning of Signalized Intersections in Realistic Urban Environment

    Directory of Open Access Journals (Sweden)

    Matej Dobovšek

    2005-05-01

    Full Text Available It is very complex to assure the dynamics of traffic networkin urban environment because of the intensity of traffic flowsand the limited space in the urban area. Signalized intersectionsare undoubtedly very important and frequent element inroad traffic network in urban regions, which greatly influencesthe traffic flow dynamics on each section as in the whole trafficnetwork. The time (delay a vehicle needs to drive through anintersection directly influences the travel comfort, fuel consumption,traffic pollution and so on. There are many methodsfor dimensioning signalized intersections in the world literature.One of the most applied methods is the HIGHWAY CAPACI1YMANUAL (HCM 2000 which is based on competentinput traffic flows and other characteristics of traffic signalregulations. The intention of this paper is to establish whetherwe can use the HCM 2000 method directly in the Slovenian realenvironment. Based on the established methodology of researchand limited number of delay measurement in real environmentintersections, there have been some deviations. Thecompletion of the level of service criterion for signalized intersectionshas been proposed, with the intention for more suitabilityestimation in the realistic environment.

  2. Applying a realistic evaluation model to occupational safety interventions

    DEFF Research Database (Denmark)

    Pedersen, Louise Møller

    2018-01-01

    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 characte......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...... characteristics of key actors (defined mechanisms), and the interplay between them, and can be categorized as expected or unexpected. However, little is known about ’how’ to include context and mechanisms in evaluations of intervention effectiveness. A revised realistic evaluation model has been introduced...... 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...

  3. Use of clinical guidelines in remote Australia: A realist evaluation.

    Science.gov (United States)

    Reddy, Sandeep; Orpin, Victoria; Herring, Sally; Mackie-Schneider, Stephanie; Struber, Janet

    2018-02-01

    The aim of this evaluation was to assess the acceptability, accessibility, and compliance with the 2014 editions of the Remote Primary Health Care Manuals (RPHCM) in health care centres across remote areas of Northern and Central Australia. To undertake a comprehensive evaluation that considered context, the evaluation used a realist evaluation framework. The evaluation used a variety of methods including interviews and survey to develop and test a programme theory. Many remote health practitioners have adopted standardized, evidence-based practice because of the use of the RPHCM. The mechanisms that led to the use of the manuals include acceptance of the worth of the protocols to their clinical practice, reliance on manual content to guide their practice, the perception of credibility, the applicability of RPHCM content to the context, and a fear of the consequences of not using the RPHCMs. Some remote health practitioners are less inclined to use the RPHCM regularly because of a perception that the content is less suited to their needs and daily practice or it is hard to navigate or understand. The evaluation concluded that there is work to be done to widen the RPHCM user base, and organizations need to increase support for their staff to use the RPHCM protocols better. These measures are expected to enable standardized clinical practice in the remote context. © 2017 John Wiley & Sons, Ltd.

  4. Lean thinking in healthcare: a realist review of the literature.

    Science.gov (United States)

    Mazzocato, Pamela; Savage, Carl; Brommels, Mats; Aronsson, Håkan; Thor, Johan

    2010-10-01

    To understand how lean thinking has been put into practice in healthcare and how it has worked. A realist literature review. Data sources The authors systematically searched for articles in PubMed, Web of Science and Business Source Premier (January 1998 to February 2008) and then added articles through a snowball approach. The authors included empirical studies of lean thinking applications in healthcare and excluded those articles that did not influence patient care, or reported hybrid approaches. The authors conducted a thematic analysis based on data collected using an original abstraction form. Based on this, they articulated interactions between context, lean interventions, mechanisms and outcomes. The authors reviewed 33 articles and found a wide range of lean applications. The articles describe initial implementation stages and emphasise technical aspects. All articles report positive results. The authors found common contextual aspects which interact with different components of the lean interventions and trigger four different change mechanisms: understand processes to generate shared understanding; organise and design for effectiveness and efficiency; improve error detection to increase awareness and process reliability; and collaborate to systematically solve problems to enhance continual improvement. Lean thinking has been applied successfully in a wide variety of healthcare settings. While lean theory emphasises a holistic view, most cases report narrower technical applications with limited organisational reach. To better realise the potential benefits, healthcare organisations need to directly involve senior management, work across functional divides, pursue value creation for patients and other customers, and nurture a long-term view of continual improvement.

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

    Science.gov (United States)

    Horridge, Patricia; And Others

    1980-01-01

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

  6. Validation of Computational Fluid Dynamics Simulations for Realistic Flows (Preprint)

    National Research Council Canada - National Science Library

    Davoudzadeh, Farhad

    2007-01-01

    Strategies used to verify and validate computational fluid dynamics (CFD) calculations are described via case studies of realistic flow simulations, each representing a complex flow physics and complex geometry...

  7. RISING POWERS AND GLOBALIZATION IN STRUCTURAL REALIST SENSE

    OpenAIRE

    AYTEKİN, Cavit Emre; MİKAİL, Elnur Hasan

    2016-01-01

    The Globalization is a phenomenon in International Relations which is expected to bring a systemic outputs especially in the polarity of International system. The rising powers concept is referred to indicate the states encouraging shifts in power structure of international system In this study the structural realist understanding of globalization and rising powers concept will be evaluated. For providing a structural-realist explanation of globalization phenomenon and rising powers concept w...

  8. 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 Fro...... that there is indeed a constructive role for a wide suite of ecosystem models to evaluate fishing strategies in an ecosystem context...

  9. 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...

  10. Track-based event recognition in a realistic crowded environment

    NARCIS (Netherlands)

    Huis, J.R. van; Bouma, H.; Baan, J.; Burghouts, G.J.; Eendebak, P.T.; Hollander, R.J.M.; Dijk, J.; Rest, J.H.C. van

    2014-01-01

    Automatic detection of abnormal behavior in CCTV cameras is important to improve the security in crowded environments, such as shopping malls, airports and railway stations. This behavior can be characterized at different time scales, e.g., by small-scale subtle and obvious actions or by large-scale

  11. Physically realistic modeling of maritime training simulation

    OpenAIRE

    Cieutat , Jean-Marc

    2003-01-01

    Maritime training simulation is an important matter of maritime teaching, which requires a lot of scientific and technical skills.In this framework, where the real time constraint has to be maintained, all physical phenomena cannot be studied; the most visual physical phenomena relating to the natural elements and the ship behaviour are reproduced only. Our swell model, based on a surface wave simulation approach, permits to simulate the shape and the propagation of a regular train of waves f...

  12. 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.

  13. Realistic training scenario simulations and simulation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Dunlop, William H.; Koncher, Tawny R.; Luke, Stanley John; Sweeney, Jerry Joseph; White, Gregory K.

    2017-12-05

    In one embodiment, a system includes a signal generator operatively coupleable to one or more detectors; and a controller, the controller being both operably coupled to the signal generator and configured to cause the signal generator to: generate one or more signals each signal being representative of at least one emergency event; and communicate one or more of the generated signal(s) to a detector to which the signal generator is operably coupled. In another embodiment, a method includes: receiving data corresponding to one or more emergency events; generating at least one signal based on the data; and communicating the generated signal(s) to a detector.

  14. From Delivery to Adoption of Physical Activity Guidelines: Realist Synthesis.

    Science.gov (United States)

    Leone, Liliana; Pesce, Caterina

    2017-10-08

    Evidence-based guidelines published by health authorities for the promotion of health-enhancing physical activity (PA), continue to be implemented unsuccessfully and demonstrate a gap between evidence and policies. This review synthesizes evidence on factors influencing delivery, adoption and implementation of PA promotion guidelines within different policy sectors (e.g., health, transport, urban planning, sport, education). Published literature was initially searched using PubMed, EBSCO, Google Scholar and continued through an iterative snowball technique. The literature review spanned the period 2002-2017. The realist synthesis approach was adopted to review the content of 39 included studies. An initial programme theory with a four-step chain from evidence emersion to implementation of guidelines was tested. The synthesis furthers our understanding of the link between PA guidelines delivery and the actions of professionals responsible for implementation within health services, school departments and municipalities. The main mechanisms identified for guidance implementation were scientific legitimation, enforcement, feasibility, familiarity with concepts and PA habits. Threats emerged to the successful implementation of PA guidelines at national/local jurisdictional levels. The way PA guidelines are developed may influence their adoption by policy-makers and professionals. Useful lessons emerged that may inform synergies between policymaking and professional practices, promoting win-win multisectoral strategies.

  15. 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.

  16. Bayesian inversion using a geologically realistic and discrete model space

    Science.gov (United States)

    Jaeggli, C.; Julien, S.; Renard, P.

    2017-12-01

    Since the early days of groundwater modeling, inverse methods play a crucial role. Many research and engineering groups aim to infer extensive knowledge of aquifer parameters from a sparse set of observations. Despite decades of dedicated research on this topic, there are still several major issues to be solved. In the hydrogeological framework, one is often confronted with underground structures that present very sharp contrasts of geophysical properties. In particular, subsoil structures such as karst conduits, channels, faults, or lenses, strongly influence groundwater flow and transport behavior of the underground. For this reason it can be essential to identify their location and shape very precisely. Unfortunately, when inverse methods are specially trained to consider such complex features, their computation effort often becomes unaffordably high. The following work is an attempt to solve this dilemma. We present a new method that is, in some sense, a compromise between the ergodicity of Markov chain Monte Carlo (McMC) methods and the efficient handling of data by the ensemble based Kalmann filters. The realistic and complex random fields are generated by a Multiple-Point Statistics (MPS) tool. Nonetheless, it is applicable with any conditional geostatistical simulation tool. Furthermore, the algorithm is independent of any parametrization what becomes most important when two parametric systems are equivalent (permeability and resistivity, speed and slowness, etc.). When compared to two existing McMC schemes, the computational effort was divided by a factor of 12.

  17. Realistic Matematic Approach through Numbered Head Together Learning Model

    Science.gov (United States)

    Sugihatno, A. C. M. S.; Budiyono; Slamet, I.

    2017-09-01

    Recently, the teaching process which is conducted based on teacher center affect the students interaction in the class. It causes students become less interest to participate. That is why teachers should be more creative in designing learning using other types of cooperative learning model. Therefore, this research is aimed to implement NHT with RMA in the teaching process. We utilize NHT since it is a variant of group discussion whose aim is giving a chance to the students to share their ideas related to the teacher’s question. By using NHT in the class, a teacher can give a better understanding about the material which is given with the help of Realistic Mathematics Approach (RMA) which known for its real problem contex. Meanwhile, the researcher assumes instead of selecting teaching model, Adversity Quotient (AQ) of student also influences students’ achievement. This research used the quasi experimental research. The samples is 60 students in junior high school, it was taken by using the stratified cluster random sampling technique. The results show NHT-RMA gives a better learning achievement of mathematics than direct teaching model and NHT-RMA teaching model with categorized as high AQ show different learning achievement from the students with categorized as moderate and low AQ.

  18. Realistic theory of electronic correlations in nanoscopic systems

    Science.gov (United States)

    Schüler, Malte; Barthel, Stefan; Wehling, Tim; Karolak, Michael; Valli, Angelo; Sangiovanni, Giorgio

    2017-07-01

    Nanostructures with open shell transition metal or molecular constituents host often strong electronic correlations and are highly sensitive to atomistic material details. This tutorial review discusses method developments and applications of theoretical approaches for the realistic description of the electronic and magnetic properties of nanostructures with correlated electrons. First, the implementation of a flexible interface between density functional theory and a variant of dynamical mean field theory (DMFT) highly suitable for the simulation of complex correlated structures is explained and illustrated. On the DMFT side, this interface is largely based on recent developments of quantum Monte Carlo and exact diagonalization techniques allowing for efficient descriptions of general four fermion Coulomb interactions, reduced symmetries and spin-orbit coupling, which are explained here. With the examples of the Cr (001) surfaces, magnetic adatoms, and molecular systems it is shown how the interplay of Hubbard U and Hund's J determines charge and spin fluctuations and how these interactions drive different sorts of correlation effects in nanosystems. Non-local interactions and correlations present a particular challenge for the theory of low dimensional systems. We present our method developments addressing these two challenges, i.e., advancements of the dynamical vertex approximation and a combination of the constrained random phase approximation with continuum medium theories. We demonstrate how non-local interaction and correlation phenomena are controlled not only by dimensionality but also by coupling to the environment which is typically important for determining the physics of nanosystems.

  19. Age differences in eyewitness memory for a realistic event.

    Science.gov (United States)

    West, Robin L; Stone, Kevin R

    2014-05-01

    To better understand the effects of misinformation on eyewitnesses of different ages, older and younger adults experienced an event under intentional and incidental learning conditions in a naturalistic experiment using multiple memory tests. Following exposure to the event, which was a brief interruption of a group testing session, participants completed several memory tests. For half of the participants, misinformation was embedded in the first cued recall test. On subsequent free recall and cued recall tests, basic scores and misinformation-based memory errors were examined. As expected, younger adults had higher recall scores than older adults. Older and younger adults made the same number of misinformation errors in free recall and in cued recall with intentional learning. However, in the incidental condition, younger adults made more misinformation errors likely due to the information processing strategies they employed after incidental learning. Misinformation effects were quite strong, even with a realistic scene and intentional learning. Older adult suggestibility was no worse than that of younger adults. When misinformation was combined with incidental learning, younger adults may have used strategic processing to encode misinformation to their detriment.

  20. Realistic effective interactions for nuclear systems

    International Nuclear Information System (INIS)

    Hjort-Jensen, M.; Osnes, E.; Kuo, T.T.S.

    1994-09-01

    A review of perturbative many-body descriptions of several nuclear systems is presented. Symmetric and asymmetric nuclear matter and finite nuclei with few valence particles are examples of systems considered. The many-body description starts with the most recent meson-exchange potential models for the nucleon-nucleon interaction, an interaction which in turn is used in perturbative schemes to evaluate the effective interaction for finite nuclei and infinite nuclear matter. A unified perturbative approach based on time-dependent perturbation theory is elaborated. For finite nuclei new results are presented for the effective interaction and the energy spectra in the mass areas of oxygen, calcium and tin. 166 refs., 83 refs., 21 tabs

  1. Robust logic gates and realistic quantum computation

    International Nuclear Information System (INIS)

    Xiao Li; Jones, Jonathan A.

    2006-01-01

    The composite rotation approach has been used to develop a range of robust quantum logic gates, including single qubit gates and two qubit gates, which are resistant to systematic errors in their implementation. Single qubit gates based on the BB1 family of composite rotations have been experimentally demonstrated in a variety of systems, but little study has been made of their application in extended computations, and there has been no experimental study of the corresponding robust two qubit gates to date. Here we describe an application of robust gates to nuclear magnetic resonance studies of approximate quantum counting. We find that the BB1 family of robust gates is indeed useful, but that the related NB1, PB1, B4, and P4 families of tailored logic gates are less useful than initially expected

  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. Realistic modeling of radiation transmission inspection systems

    International Nuclear Information System (INIS)

    Sale, K.E.

    1993-01-01

    We have applied Monte Carlo particle transport methods to assess a proposed neutron transmission inspection system for checked luggage. The geometry of the system and the time, energy and angle dependence of the source have been modeled in detail. A pulsed deuteron beam incident on a thick Be target generates a neutron pulse with a very broad energy spectrum which is detected after passage through the luggage item by a plastic scintillator detector operating in current mode (as opposed to pulse counting mode). The neutron transmission as a function of time information is used to infer the densities of hydrogen, carbon, oxygen and nitrogen in the volume sampled. The measured elemental densities can be compared to signatures for explosives or other contraband. By using such computational modeling it is possible to optimize many aspects of the design of an inspection system without costly and time consuming prototyping experiments or to determine that a proposed scheme will not work. The methods applied here can be used to evaluate neutron or photon schemes based on transmission, scattering or reaction techniques

  4. 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.

  5. Realistic Real-Time Outdoor Rendering in Augmented Reality

    Science.gov (United States)

    Kolivand, Hoshang; Sunar, Mohd Shahrizal

    2014-01-01

    Realistic rendering techniques of outdoor Augmented Reality (AR) has been an attractive topic since the last two decades considering the sizeable amount of publications in computer graphics. Realistic virtual objects in outdoor rendering AR systems require sophisticated effects such as: shadows, daylight and interactions between sky colours and virtual as well as real objects. A few realistic rendering techniques have been designed to overcome this obstacle, most of which are related to non real-time rendering. However, the problem still remains, especially in outdoor rendering. This paper proposed a much newer, unique technique to achieve realistic real-time outdoor rendering, while taking into account the interaction between sky colours and objects in AR systems with respect to shadows in any specific location, date and time. This approach involves three main phases, which cover different outdoor AR rendering requirements. Firstly, sky colour was generated with respect to the position of the sun. Second step involves the shadow generation algorithm, Z-Partitioning: Gaussian and Fog Shadow Maps (Z-GaF Shadow Maps). Lastly, a technique to integrate sky colours and shadows through its effects on virtual objects in the AR system, is introduced. The experimental results reveal that the proposed technique has significantly improved the realism of real-time outdoor AR rendering, thus solving the problem of realistic AR systems. PMID:25268480

  6. Problem Posing with Realistic Mathematics Education Approach in Geometry Learning

    Science.gov (United States)

    Mahendra, R.; Slamet, I.; Budiyono

    2017-09-01

    One of the difficulties of students in the learning of geometry is on the subject of plane that requires students to understand the abstract matter. The aim of this research is to determine the effect of Problem Posing learning model with Realistic Mathematics Education Approach in geometry learning. This quasi experimental research was conducted in one of the junior high schools in Karanganyar, Indonesia. The sample was taken using stratified cluster random sampling technique. The results of this research indicate that the model of Problem Posing learning with Realistic Mathematics Education Approach can improve students’ conceptual understanding significantly in geometry learning especially on plane topics. It is because students on the application of Problem Posing with Realistic Mathematics Education Approach are become to be active in constructing their knowledge, proposing, and problem solving in realistic, so it easier for students to understand concepts and solve the problems. Therefore, the model of Problem Posing learning with Realistic Mathematics Education Approach is appropriately applied in mathematics learning especially on geometry material. Furthermore, the impact can improve student achievement.

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

    Directory of Open Access Journals (Sweden)

    Hoshang Kolivand

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

  8. 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

  9. Survey of Approaches to Generate Realistic Synthetic Graphs

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-01

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

  10. Realistic assessment of break size in simulated BWR loss-of-coolant accidents

    International Nuclear Information System (INIS)

    Andersen, J.G.M.; Heck, C.L.; Klebanov, L.A.; Shiralkar, B.S.

    2009-01-01

    Realistic loss-of-coolant accident (LOCA) licensing methodologies offer an alternative to conservative methodologies that have been used historically. Less realistic analyses based on conservative assumptions and/or inputs may potentially misrepresent or conceal complicated interactions between competing phenomenological processes. The calculated results from the historical methods for the key LOCA licensing parameters including the most important parameter peak clad temperature (PCT) are generally expected to be conservative but may be non-conservative for some scenarios. In contrast, realistic methodologies attempt to model all important phenomena without making any grossly conservative assumptions that will distort the results. The paper demonstrates that realistic calculations must accurately account for the complex balance between the heat production and heat removal processes. Specific elements such as plant and bundle design, plant initial conditions and boundary conditions, and details of the LOCA scenario that include equipment availability and break size and location influence the balances between competing processes and thereby determine the calculated value of the PCT. For example, the break size and location influences the depressurization rate, the distribution of fluid inventory, and the timing of flashing in different parts of the system. The Automatic Depressurization System (ADS) also affects the depressurization rate (especially for small breaks). The Emergency Core Cooling System (ECCS) triggered by depressurization delivers fluid to the core to make up for lost inventory. The paper illustrates and discusses the relative importance of these phenomena and mechanisms, their timing and interactions, and their impact on the calculated PCT for different break sizes. Realistic calculations made with TRACG reveal that the maximum PCT for BWR plants with jet pumps occur at a smaller break size than the traditional design-basis accident (DBA) break size

  11. Realistic respiratory motion margins for external beam partial breast irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Conroy, Leigh; Quirk, Sarah [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Smith, Wendy L., E-mail: wendy.smith@albertahealthservices.ca [Department of Medical Physics, Tom Baker Cancer Centre, Calgary, Alberta T2N 4N2 (Canada); Department of Physics and Astronomy, University of Calgary, Calgary, Alberta T2N 1N4 (Canada); Department of Oncology, University of Calgary, Calgary, Alberta T2N 1N4 (Canada)

    2015-09-15

    Purpose: Respiratory margins for partial breast irradiation (PBI) have been largely based on geometric observations, which may overestimate the margin required for dosimetric coverage. In this study, dosimetric population-based respiratory margins and margin formulas for external beam partial breast irradiation are determined. Methods: Volunteer respiratory data and anterior–posterior (AP) dose profiles from clinical treatment plans of 28 3D conformal radiotherapy (3DCRT) PBI patient plans were used to determine population-based respiratory margins. The peak-to-peak amplitudes (A) of realistic respiratory motion data from healthy volunteers were scaled from A = 1 to 10 mm to create respiratory motion probability density functions. Dose profiles were convolved with the respiratory probability density functions to produce blurred dose profiles accounting for respiratory motion. The required margins were found by measuring the distance between the simulated treatment and original dose profiles at the 95% isodose level. Results: The symmetric dosimetric respiratory margins to cover 90%, 95%, and 100% of the simulated treatment population were 1.5, 2, and 4 mm, respectively. With patient set up at end exhale, the required margins were larger in the anterior direction than the posterior. For respiratory amplitudes less than 5 mm, the population-based margins can be expressed as a fraction of the extent of respiratory motion. The derived formulas in the anterior/posterior directions for 90%, 95%, and 100% simulated population coverage were 0.45A/0.25A, 0.50A/0.30A, and 0.70A/0.40A. The differences in formulas for different population coverage criteria demonstrate that respiratory trace shape and baseline drift characteristics affect individual respiratory margins even for the same average peak-to-peak amplitude. Conclusions: A methodology for determining population-based respiratory margins using real respiratory motion patterns and dose profiles in the AP direction was

  12. Fatigue - determination of a more realistic usage factor

    International Nuclear Information System (INIS)

    Lang, H.

    2001-01-01

    The ability to use a suitable counting method for determining the stress range spectrum in elastic and simplified elastic-plastic fatigue analyses is of crucial importance for enabling determination of a realistic usage factor. Determination of elastic-plastic strain range using the K e factor from fictitious elastically calculated loads is also important in the event of elastic behaviour being exceeded. This paper thus examines both points in detail. A fatigue module with additional options, which functions on this basis is presented. The much more realistic determination of usage factor presented here offers various economic benefits depending on the application

  13. The effects of realistic pancake solenoids on particle transport

    Science.gov (United States)

    Gu, X.; Okamura, M.; Pikin, A.; Fischer, W.; Luo, Y.

    2011-05-01

    Solenoids are widely used to transport or focus particle beams. Usually, they are assumed as being ideal solenoids with a high axial-symmetry magnetic field. Using the Vector Fields Opera program, we modeled asymmetrical solenoids with realistic geometry defects, caused by finite conductor and current jumpers. Their multipole magnetic components were analyzed with the Fourier fit method; we present some possible optimized methods for them. We also discuss the effects of "realistic" solenoids on low energy particle transport. The findings in this paper may be applicable to the lower energy particle transport system design.

  14. 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...

  15. Sim4CV: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Müller, Matthias

    2018-03-24

    We present a photo-realistic training and evaluation simulator (Sim4CV) (http://www.sim4cv.org) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  16. UE4Sim: A Photo-Realistic Simulator for Computer Vision Applications

    KAUST Repository

    Mueller, Matthias

    2017-08-19

    We present a photo-realistic training and evaluation simulator (UE4Sim) with extensive applications across various fields of computer vision. Built on top of the Unreal Engine, the simulator integrates full featured physics based cars, unmanned aerial vehicles (UAVs), and animated human actors in diverse urban and suburban 3D environments. We demonstrate the versatility of the simulator with two case studies: autonomous UAV-based tracking of moving objects and autonomous driving using supervised learning. The simulator fully integrates both several state-of-the-art tracking algorithms with a benchmark evaluation tool and a deep neural network (DNN) architecture for training vehicles to drive autonomously. It generates synthetic photo-realistic datasets with automatic ground truth annotations to easily extend existing real-world datasets and provides extensive synthetic data variety through its ability to reconfigure synthetic worlds on the fly using an automatic world generation tool.

  17. Acoustic simulation in realistic 3D virtual scenes

    Science.gov (United States)

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

    2003-09-01

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

  18. 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.

  19. Vietnam's Post-Cold War Hedging Strategy: A Changing Mix of Realist and Liberal Ingredients

    OpenAIRE

    Thi Bich Tran; Sato, Yoichiro

    2018-01-01

    Abstract: This article aims at improving precision in the theoretical discussions of "hedging" strategy. It proposes a generalizable basket of the strategy's components. It then examines the evolution of Vietnam's hedging strategy since the end of the Cold War based on this framework. The findings show that Vietnam's hedging strategy is a dynamically changing mix of four realist and liberal ingredients (diplomatic engagement, economic engagement, soft balancing, and hard balancing). The most ...

  20. The visualizable, the representable and the inconceivable: realist and non-realist mathematical models in physics and beyond.

    Science.gov (United States)

    Plotnitsky, Arkady

    2016-01-13

    The project of this article is twofold. First, it aims to offer a new perspective on, and a new argument concerning, realist and non-realist mathematical models, and differences and affinities between them, using physics as a paradigmatic field of mathematical modelling in science. Most of the article is devoted to this topic. Second, the article aims to explore the implications of this argument for mathematical modelling in other fields, in particular in cognitive psychology and economics. © 2015 The Author(s).

  1. Generalized Warburg impedance on realistic self-affine fractals ...

    Indian Academy of Sciences (India)

    Administrator

    Generalized Warburg impedance on realistic self-affine fractals: Comparative study of statistically corrugated and isotropic roughness. RAJESH KUMAR and RAMA KANT. Journal of Chemical Sciences, Vol. 121, No. 5, September 2009, pp. 579–588. 1. ( ) c. L. R ω on page 582, column 2, para 2, after eq (8) should read as ...

  2. Principles of maximally classical and maximally realistic quantum ...

    Indian Academy of Sciences (India)

    so different from the classical trajectories that they are sometimes called surrealistic [4]!. The answer to the first problem above is in the construction of maximally realistic quan- tum mechanics [5,6] which treats position and momentum symmetrically. We present in this paper the answer to the second problem in the form of a ...

  3. Towards a Realist Sociology of Education: A Polyphonic Review Essay

    Science.gov (United States)

    Grenfell, Michael; Hood, Susan; Barrett, Brian D.; Schubert, Dan

    2017-01-01

    This review essay evaluates Karl Maton's "Knowledge and Knowers: Towards a Realist Sociology of Education" as a recent examination of the sociological causes and effects of education in the tradition of the French social theorist Pierre Bourdieu and the British educational sociologist Basil Bernstein. Maton's book synthesizes the…

  4. Creating a Realistic Context for Team Projects in HCI

    NARCIS (Netherlands)

    Koppelman, Herman; van Dijk, Betsy

    2006-01-01

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

  5. Hope in Janusz Korczak's Pedagogy of Realistic Idealism

    Science.gov (United States)

    Silverman, Marc

    2017-01-01

    This article explores the approach of "Realistic Idealism" to moral education developed by the humanist-progressive moral educator Janusz Korczak, and the role hope plays in it. This pair of terms seems to be an oxymoron. However, their employment is intentional and the article will demonstrate their dialectical interdependence:…

  6. 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)

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

    Science.gov (United States)

    Rochelle, Warren

    1991-01-01

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

  8. Representations of Adoption in Contemporary Realistic Fiction for Young Adults

    Science.gov (United States)

    Parsons, Sue Christian; Fuxa, Robin; Kander, Faryl; Hardy, Dana

    2017-01-01

    In this critical content analysis of thirty-seven contemporary realistic fiction books about adoption, the authors examine how adoption and adoptive families are depicted in young adult (YA) literature. The critical literacy theoretical frame brings into focus significant social implications of these depictions as the researchers illuminate and…

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

    Science.gov (United States)

    Tyson, Cynthia A.

    1999-01-01

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

  10. Two-Capacitor Problem: A More Realistic View.

    Science.gov (United States)

    Powell, R. A.

    1979-01-01

    Discusses the two-capacitor problem by considering the self-inductance of the circuit used and by determining how well the usual series RC circuit approximates the two-capacitor problem when realistic values of L, C, and R are chosen. (GA)

  11. Engendering Anthropocentrism: Lessons from Children's Realistic Animal Stories.

    Science.gov (United States)

    Johnson, Kathleen R.

    In children's realistic stories about animals a number of wholly and unambiguously anthropocentric assumptions are at work. For instance, in a study most of the books (81%) in one sampling of 50 stories involve a pet or the process of domesticating a wild animal. In most cases the primary animal character is a dog or horse. The predominance of…

  12. Principles of maximally classical and maximally realistic quantum

    Indian Academy of Sciences (India)

    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 ...

  13. Principles of maximally classical and maximally realistic quantum ...

    Indian Academy of Sciences (India)

    Principles of maximally classical and maximally realistic quantum mechanics. S M ROY. Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400 005, India. Abstract. Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2N-dimensional phase space, ...

  14. Principles of maximally classical and maximally realistic quantum ...

    Indian Academy of Sciences (India)

    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 ...

  15. 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.

  16. Using a Realist Research Methodology in Policy Analysis

    Science.gov (United States)

    Lourie, Megan; Rata, Elizabeth

    2017-01-01

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

  17. Using Realistic Business Data in Teaching Business Problem Solving.

    Science.gov (United States)

    Chen, Catherine

    2000-01-01

    Describes a business data generator to assist instructors in generating realistic business data in great volume for teaching and learning activities. Illustrates how the software application allows instructors to manipulate parameters to customize the data to reflect problem situation. (Contains 40 references.) (JOW)

  18. 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

  19. A linear evolution for non-linear dynamics and correlations in realistic nuclei

    International Nuclear Information System (INIS)

    Levin, E.; Lublinsky, M.

    2004-01-01

    A new approach to high energy evolution based on a linear equation for QCD generating functional is developed. This approach opens a possibility for systematic study of correlations inside targets, and, in particular, inside realistic nuclei. Our results are presented as three new equations. The first one is a linear equation for QCD generating functional (and for scattering amplitude) that sums the 'fan' diagrams. For the amplitude this equation is equivalent to the non-linear Balitsky-Kovchegov equation. The second equation is a generalization of the Balitsky-Kovchegov non-linear equation to interactions with realistic nuclei. It includes a new correlation parameter which incorporates, in a model-dependent way, correlations inside the nuclei. The third equation is a non-linear equation for QCD generating functional (and for scattering amplitude) that in addition to the 'fan' diagrams sums the Glauber-Mueller multiple rescatterings

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

    Science.gov (United States)

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

    2015-01-01

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

  1. A Realistic Human Exposure Assessment of Indoor Radon released from Groundwater

    International Nuclear Information System (INIS)

    Yu, Dong Han; Han, Moon Hee

    2002-01-01

    The work presents a realistic human exposure assessment of indoor radon released from groundwater in a house. At first, a two-compartment model is developed to describe the generation and transfer of radon in indoor air from groundwater. The model is used to estimate radon concentrations profile of indoor air in a house using by showering, washing clothes, and flushing toilets. Then, the study performs an uncertainty analysis of model input parameters to quantify the uncertainty in radon concentration profile. In order to estimate a daily internal dose of a specific tissue group in an adult through the inhalation of such indoor radon, a PBPK(Physiologically-Based Pharmaco-Kinetic) model is developed. Combining indoor radon profile and PBPK model is used to a realistic human assessment for such exposure. The results obtained from this study would be used to the evaluation of human risk by inhalation associated with the indoor radon released from groundwater

  2. 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.

  3. 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

  4. Realistic and unrealistic direst costs in pharmacoeconomic anesthesia studies

    Directory of Open Access Journals (Sweden)

    Majstorović Branislava M.

    2017-01-01

    ,01. Conclusions: Anesthesia and anesthetic services show statistically significant and financially significant correlation with the direct costs and duration of anesthesia within different surgical specialties. Cosidering direct costs, only the costs of anesthetic drugs and materials are realistic, and all other elements are determined by law and by contract with NHIF. Other costs, out of the direct costs group shall be theoretically reduced by running the analyzes required for anesthesia and for the planned surgical intervention in primary health care protection. Data base related to surgical data and better computer programs able to monitor multiple parameters during hospital treatment, could determine more precisely the value of anesthetic services.

  5. 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)

  6. Realistic full wave modeling of focal plane array pixels.

    Energy Technology Data Exchange (ETDEWEB)

    Campione, Salvatore [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Warne, Larry K. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Jorgenson, Roy E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Electromagnetic Theory Dept.; Davids, Paul [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.; Peters, David W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States). Applied Photonic Microsystems Dept.

    2017-11-01

    Here, we investigate full-wave simulations of realistic implementations of multifunctional nanoantenna enabled detectors (NEDs). We focus on a 2x2 pixelated array structure that supports two wavelengths of operation. We design each resonating structure independently using full-wave simulations with periodic boundary conditions mimicking the whole infinite array. We then construct a supercell made of a 2x2 pixelated array with periodic boundary conditions mimicking the full NED; in this case, however, each pixel comprises 10-20 antennas per side. In this way, the cross-talk between contiguous pixels is accounted for in our simulations. We observe that, even though there are finite extent effects, the pixels work as designed, each responding at the respective wavelength of operation. This allows us to stress that realistic simulations of multifunctional NEDs need to be performed to verify the design functionality by taking into account finite extent and cross-talk effects.

  7. Realistic minimum accident source terms - Evaluation, application, and risk acceptance

    International Nuclear Information System (INIS)

    Angelo, P. L.

    2009-01-01

    The evaluation, application, and risk acceptance for realistic minimum accident source terms can represent a complex and arduous undertaking. This effort poses a very high impact to design, construction cost, operations and maintenance, and integrated safety over the expected facility lifetime. At the 2005 Nuclear Criticality Safety Division (NCSD) Meeting in Knoxville Tenn., two papers were presented mat summarized the Y-12 effort that reduced the number of criticality accident alarm system (CAAS) detectors originally designed for the new Highly Enriched Uranium Materials Facility (HEUMF) from 258 to an eventual as-built number of 60. Part of that effort relied on determining a realistic minimum accident source term specific to the facility. Since that time, the rationale for an alternate minimum accident has been strengthened by an evaluation process that incorporates realism. A recent update to the HEUMF CAAS technical basis highlights the concepts presented here. (authors)

  8. Realistic electricity market simulator for energy and economic studies

    International Nuclear Information System (INIS)

    Bernal-Agustin, Jose L.; Contreras, Javier; Conejo, Antonio J.; Martin-Flores, Raul

    2007-01-01

    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)

  9. Real-time Realistic Rendering and Lighting of Forests

    OpenAIRE

    Bruneton, Eric; Neyret, Fabrice

    2012-01-01

    Special issue: Proceedings of Eurographics 2011; International audience; Realistic real-time rendering and lighting of forests is an important aspect for simulators and video games. This is a difficult problem, due to the massive amount of geometry: aerial forest views display millions of trees on a wide range of distances, from the camera to the horizon. Light interactions, whose effects are visible at all scales, are also a problem: sun and sky dome contributions, shadows between trees, ins...

  10. A scan for models with realistic fermion mass patterns

    International Nuclear Information System (INIS)

    Bijnens, J.; Wetterich, C.

    1986-03-01

    We consider models which have no small Yukawa couplings unrelated to symmetry. This situation is generic in higher dimensional unification where Yukawa couplings are predicted to have strength similar to the gauge couplings. Generations have then to be differentiated by symmetry properties and the structure of fermion mass matrices is given in terms of quantum numbers alone. We scan possible symmetries leading to realistic mass matrices. (orig.)

  11. Who has realistic income expectations: students or workers?

    OpenAIRE

    Jerrim, John

    2010-01-01

    I analyse a nationally representative, longitudinal dataset to investigate the income expectations of 20 American year old men over a 10 year time horizon. Specifically, I compare the accuracy of students’ expectations to young adults from the same cohort who have chosen to enter the labour force. The results indicate that 20 year old American men overestimate their income at age 30 by an average of 50%. Yet, there is little evidence that those in the labour force are more realistic than thei...

  12. Providing oxygen to children in hospitals: a realist review

    OpenAIRE

    Graham, Hamish; Tosif, Shidan; Gray, Amy; Qazi, Shamim; Campbell, Harry; Peel, David; McPake, Barbara; Duke, Trevor

    2017-01-01

    Abstract Objective To identify and describe interventions to improve oxygen therapy in hospitals in low-resource settings, and to determine the factors that contribute to success and failure in different contexts. Methods Using realist review methods, we scanned the literature and contacted experts in the field to identify possible mechanistic theories of how interventions to improve oxygen therapy systems might work. Then we systematically searched online databases for evaluations of improve...

  13. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Methodology for estimating realistic responses of buildings and components under earthquake motion and its application

    International Nuclear Information System (INIS)

    Ebisawa, Katsumi; Abe, Kiyoharu; Kohno, Kunihiko; Nakamura, Hidetaka; Itoh, Mamoru.

    1996-11-01

    Failure probabilities of buildings and components under earthquake motion are estimated as conditional probabilities that their realistic responses exceed their capacities. Two methods for estimating their failure probabilities have already been developed. One is a detailed method developed in the Seismic Safety margins Research Program of Lawrence Livermore National Laboratory in U.S.A., which is called 'SSMRP method'. The other is a simplified method proposed by Kennedy et al., which is called 'Zion method'. The Zion method is sometimes called 'response factor method'. The authors adopted the response factor method. In order to enhance the estimation accuracy of failure probabilities of buildings and components, however, a new methodology for improving the response factor method was proposed. Based on the improved method, response factors of buildings and components designed to seismic design standard in Japan were estimated, and their realistic responses were also calculated. By using their realistic responses and capacities, the failure probabilities of a reactor building and relays were estimated. In order to identify the difference between new method, SSMRP method and original response factor method, the failure probabilities were compared estimated by these three methods. A similar method of SSMRP was used instead of the original SSMRP for saving time and labor. The viewpoints for selecting the methods to estimate failure probabilities of buildings and components were also proposed. (author). 55 refs

  15. The impact of realistic age structure in simple models of tuberculosis transmission.

    Science.gov (United States)

    Brooks-Pollock, Ellen; Cohen, Ted; Murray, Megan

    2010-01-07

    Mathematical models of tuberculosis (TB) transmission have been used to characterize disease dynamics, investigate the potential effects of public health interventions, and prioritize control measures. While previous work has addressed the mathematical description of TB natural history, the impact of demography on the behaviour of TB models has not been assessed. A simple model of TB transmission, with alternative assumptions about survivorship, is used to explore the effect of age structure on the prevalence of infection, disease, basic reproductive ratio and the projected impact of control interventions. We focus our analytic arguments on the differences between constant and exponentially distributed lifespans and use an individual-based model to investigate the range of behaviour arising from realistic distributions of survivorship. The choice of age structure and natural (non-disease related) mortality strongly affects steady-state dynamics, parameter estimation and predictions about the effectiveness of control interventions. Since most individuals infected with TB develop an asymptomatic latent infection and never progress to active disease, we find that assuming a constant mortality rate results in a larger reproductive ratio and an overestimation of the effort required for disease control in comparison to using more realistic age-specific mortality rates. Demographic modelling assumptions should be considered in the interpretation of models of chronic infectious diseases such as TB. For simple models, we find that assuming constant lifetimes, rather than exponential lifetimes, produces dynamics more representative of models with realistic age structure.

  16. Rapid creation, Monte Carlo simulation, and visualization of realistic 3D cell models.

    Science.gov (United States)

    Czech, Jacob; Dittrich, Markus; Stiles, Joel R

    2009-01-01

    Spatially realistic diffusion-reaction simulations supplement traditional experiments and provide testable hypotheses for complex physiological systems. To date, however, the creation of realistic 3D cell models has been difficult and time-consuming, typically involving hand reconstruction from electron microscopic images. Here, we present a complementary approach that is much simpler and faster, because the cell architecture (geometry) is created directly in silico using 3D modeling software like that used for commercial film animations. We show how a freely available open source program (Blender) can be used to create the model geometry, which then can be read by our Monte Carlo simulation and visualization softwares (MCell and DReAMM, respectively). This new workflow allows rapid prototyping and development of realistic computational models, and thus should dramatically accelerate their use by a wide variety of computational and experimental investigators. Using two self-contained examples based on synaptic transmission, we illustrate the creation of 3D cellular geometry with Blender, addition of molecules, reactions, and other run-time conditions using MCell's Model Description Language (MDL), and subsequent MCell simulations and DReAMM visualizations. In the first example, we simulate calcium influx through voltage-gated channels localized on a presynaptic bouton, with subsequent intracellular calcium diffusion and binding to sites on synaptic vesicles. In the second example, we simulate neurotransmitter release from synaptic vesicles as they fuse with the presynaptic membrane, subsequent transmitter diffusion into the synaptic cleft, and binding to postsynaptic receptors on a dendritic spine.

  17. Realistic simplified gaugino-higgsino models in the MSSM

    Science.gov (United States)

    Fuks, Benjamin; Klasen, Michael; Schmiemann, Saskia; Sunder, Marthijn

    2018-03-01

    We present simplified MSSM models for light neutralinos and charginos with realistic mass spectra and realistic gaugino-higgsino mixing, that can be used in experimental searches at the LHC. The formerly used naive approach of defining mass spectra and mixing matrix elements manually and independently of each other does not yield genuine MSSM benchmarks. We suggest the use of less simplified, but realistic MSSM models, whose mass spectra and mixing matrix elements are the result of a proper matrix diagonalisation. We propose a novel strategy targeting the design of such benchmark scenarios, accounting for user-defined constraints in terms of masses and particle mixing. We apply it to the higgsino case and implement a scan in the four relevant underlying parameters {μ , tan β , M1, M2} for a given set of light neutralino and chargino masses. We define a measure for the quality of the obtained benchmarks, that also includes criteria to assess the higgsino content of the resulting charginos and neutralinos. We finally discuss the distribution of the resulting models in the MSSM parameter space as well as their implications for supersymmetric dark matter phenomenology.

  18. Bell Operator Method to Classify Local Realistic Theories

    International Nuclear Information System (INIS)

    Nagata, Koji

    2010-01-01

    We review the historical fact of multipartite Bell inequalities with an arbitrary number of settings. An explicit local realistic model for the values of a correlation function, given in a two-setting Bell experiment (two-setting model), works only for the specific set of settings in the given experiment, but cannot construct a local realistic model for the values of a correlation function, given in a continuous-infinite settings Bell experiment (infinite-setting model), even though there exist two-setting models for all directions in space. Hence, the two-setting model does not have the property that the infinite-setting model has. Here, we show that an explicit two-setting model cannot construct a local realistic model for the values of a correlation function, given in an M-setting Bell experiment (M-setting model), even though there exist two-setting models for the M measurement directions chosen in the given M-setting experiment. Hence, the two-setting model does not have the property that the M-setting model has. (general)

  19. The Electrostatic Instability for Realistic Pair Distributions in Blazar/EBL Cascades

    Science.gov (United States)

    Vafin, S.; Rafighi, I.; Pohl, M.; Niemiec, J.

    2018-04-01

    This work revisits the electrostatic instability for blazar-induced pair beams propagating through the intergalactic medium (IGM) using linear analysis and PIC simulations. We study the impact of the realistic distribution function of pairs resulting from the interaction of high-energy gamma-rays with the extragalactic background light. We present analytical and numerical calculations of the linear growth rate of the instability for the arbitrary orientation of wave vectors. Our results explicitly demonstrate that the finite angular spread of the beam dramatically affects the growth rate of the waves, leading to the fastest growth for wave vectors quasi-parallel to the beam direction and a growth rate at oblique directions that is only a factor of 2–4 smaller compared to the maximum. To study the nonlinear beam relaxation, we performed PIC simulations that take into account a realistic wide-energy distribution of beam particles. The parameters of the simulated beam-plasma system provide an adequate physical picture that can be extrapolated to realistic blazar-induced pairs. In our simulations, the beam looses only 1% of its energy, and we analytically estimate that the beam would lose its total energy over about 100 simulation times. An analytical scaling is then used to extrapolate the parameters of realistic blazar-induced pair beams. We find that they can dissipate their energy slightly faster by the electrostatic instability than through inverse-Compton scattering. The uncertainties arising from, e.g., details of the primary gamma-ray spectrum are too large to make firm statements for individual blazars, and an analysis based on their specific properties is required.

  20. 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

  1. 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 developed...

  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. Gauge coupling unification in realistic free-fermionic string models

    International Nuclear Information System (INIS)

    Dienes, K.R.; Faraggi, A.E.

    1995-01-01

    We discuss the unification of gauge couplings within the framework of a wide class of realistic free-fermionic string models which have appeared in the literature, including the flipped SU(5), SO(6)xSO(4), and various SU(3)xSU(2)xU(1) models. If the matter spectrum below the string scale is that of the Minimal Supersymmetric Standard Model (MSSM), then string unification is in disagreement with experiment. We therefore examine several effects that may modify the minimal string predictions. First, we develop a systematic procedure for evaluating the one-loop heavy string threshold corrections in free-fermionic string models, and we explicitly evaluate these corrections for each of the realistic models. We find that these string threshold corrections are small, and we provide general arguments explaining why such threshold corrections are suppressed in string theory. Thus heavy thresholds cannot resolve the disagreement with experiment. We also study the effect of non-standard hypercharge normalizations, light SUSY thresholds, and intermediate-scale gauge structure, and similarly conclude that these effects cannot resolve the disagreement with low-energy data. Finally, we examine the effects of additional color triplets and electroweak doublets beyond the MSSM. Although not required in ordinary grand unification scenarios, such states generically appear within the context of certain realistic free-fermionic string models. We show that if these states exist at the appropriate thresholds, then the gauge couplings will indeed unify at the string scale. Thus, within these string models, string unification can be in agreement with low-energy data. (orig.)

  4. Towards dense, realistic granular media in 2D

    International Nuclear Information System (INIS)

    Luding, Stefan

    2009-01-01

    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)

  5. Black holes in realistic branes: Black string-like objects?

    Energy Technology Data Exchange (ETDEWEB)

    Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Instituto de Física, Universidade de São Paulo, 05314-970, São Paulo, SP (Brazil); Departamento de Física, Universidade Federal da Paraíba, 58051-970, João Pessoa, PB (Brazil); Hoff da Silva, J.M., E-mail: hoff@feg.unesp.br [Departamento de Física e Química, Universidade Estadual Paulista, Av. Dr. Ariberto Pereira da Cunha, 333, Guaratinguetá, SP (Brazil); Rocha, Roldão da, E-mail: roldao.rocha@ufabc.edu.br [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC (UFABC), 09210-170, Santo André, SP (Brazil)

    2013-04-25

    A realistic model describing a black string-like object in an expanding Universe is analyzed in the context of the McVittie's solution of the Einstein field equations. The bulk metric near the brane is provided analogously to previous solutions for black strings. In particular, we show that at least when the Hubble parameter on the brane is positive, a black string-like object seems to play a fundamental role in the braneworld scenario, generalizing the standard black strings in the context of a dynamical brane.

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

    Science.gov (United States)

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

    2016-12-19

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

  7. Percolation dans des reseaux realistes de nanostructures de carbone

    Science.gov (United States)

    Simoneau, Louis-Philippe

    Carbon nanotubes have very interesting mechanical and electrical properties for various applications in electronics. They are highly resistant to deformation and can be excellent conductors or semiconductors. However, manipulating individual nanotubes to build structured devices remains very difficult. There is no method for controlling all of the electrical properties, the orientation and the spatial positioning of a large number of nanotubes. The fabrication of disordered networks of nanotubes is much easier, and these systems have a good electrical conductivity which makes them very interesting, especially as materials of transparent and flexible electrodes. There are three main methods of production used to make networks of nanotubes: the solution deposition, the direct growth on substrate and the embedding in a polymer matrix. The solution deposition method can form networks of various densities on a variety of substrates, the direct growth of nanotubes allows the creation of very clean networks on substrates such as SiO2, and the embedding in a polymer matrix can give composite volumes containing varying amounts of nanotubes. Many parameters such as the length of the tubes, their orientation or their tortuosity influence the properties of these networks and the presence of structural disorder complicates the understanding of their interactions. Predicting the properties of a network, such as conductivity, from a few characteristics such as size and density of the tubes can be difficult. This task becomes even more complex if one wants to identify the parameters that will optimize the performance of a device containing the material. We chose to address the carbon nanotube networks problem by developing a series of computer simulation tools that are mainly based on the Monte Carlo method. We take into account a large number of parameters to describe the characteristics of the networks, which allows for a more reliable representation of real networks as well as

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

    DEFF Research Database (Denmark)

    Putra, Zetra Hainul

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

  9. Neural Correlates of Realistic and Unrealistic Auditory Space Perception

    Directory of Open Access Journals (Sweden)

    Akiko Callan

    2011-10-01

    Full Text Available Binaural recordings can simulate externalized auditory space perception over headphones. However, if the orientation of the recorder's head and the orientation of the listener's head are incongruent, the simulated auditory space is not realistic. For example, if a person lying flat on a bed listens to an environmental sound that was recorded by microphones inserted in ears of a person who was in an upright position, the sound simulates an auditory space rotated 90 degrees to the real-world horizontal axis. Our question is whether brain activation patterns are different between the unrealistic auditory space (ie, the orientation of the listener's head and the orientation of the recorder's head are incongruent and the realistic auditory space (ie, the orientations are congruent. River sounds that were binaurally recorded either in a supine position or in an upright body position were served as auditory stimuli. During fMRI experiments, participants listen to the stimuli and pressed one of two buttons indicating the direction of the water flow (horizontal/vertical. Behavioral results indicated that participants could not differentiate between the congruent and the incongruent conditions. However, neuroimaging results showed that the congruent condition activated the planum temporale significantly more than the incongruent condition.

  10. 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.

  11. Effects of realistic satellite shielding on SEE rates

    International Nuclear Information System (INIS)

    Smith, E.C.

    1994-01-01

    Realistic models of satellite shielding have been used to calculate SEE rates for Galactic Cosmic Rays (GCR) and solar flare protons. The results are compared with those obtained with a nominal 0.1 inch spherical shield. The rates for GCR (solar minimum) are systematically lower than those calculated with the nominal shield. The ratio of rates is greater than 75% for lightly shielded devices, but may be as high as a factor of two where there is shielding by other circuit boards. A more nearly realistic estimate of the rates would be obtained with a spherical shield with a thickness of at least 0.4 inches (3 gm/cm 2 ) for the typical satellites considered. The calculation of the SEE rate due to protons was reformulated to expedite shielding calculations. When the method was applied to the 93L422 RAM for various flare spectra, it was apparent that shielding has a first order effect on rate predictions. The calculated flare upset rates for the TDRS satellite were within 20% of the observed rates. A spherical shield of thickness 0.3 inches (2 gm/cm 2 ) would reproduce the rates. The method was also applied to a trapped proton environment predicted from standard models for CRRES. The predicted rate was consistent with the uncertainties of the environment

  12. Toward the classification of the realistic free fermionic models

    International Nuclear Information System (INIS)

    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

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

    Science.gov (United States)

    Bromaghin, Jeffrey F.

    2015-01-01

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

  14. Numerical simulation of inhaled aerosol particle deposition within 3D realistic human upper respiratory tract

    Science.gov (United States)

    Lin, J.; Fan, J. R.; Zheng, Y. Q.; Hu, G. L.; Pan, D.

    2010-03-01

    Computational fluid dynamics (CFD) simulations of airflow and particle deposition in the upper respiratory tract (URT) were conducted in this paper. Based on the CT (Computerized Tomography) scanned images of a 19-years-old healthy boy, a realistic geometric model of URT from oral cavity to the upper six-generation bronchial is rebuilt. To investigate airflow and particle deposition in the obtained realistic human upper respiratory tract, RNG k-ɛ turbulence model was used to describe the primary flow and particle deposition under three breathing intensity such as 15 L/min, 30 L/min and 60 L/min. The particle is tracked and analyzed in the Lagrangian frame. The velocity fields of airflow under different airflow rates were computed and discussed. In order to study the characteristics of particles movement and the effect of particles diameter on the deposition pattern, eleven kinds of sphere particles with different diameters are selected as research object. The diameters of selected particles as follows: 0.1 μm, 0.5 μm, 1 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 6.5 μm and 8 μm. The variation of inhalable particles deposition in realistic human upper respiratory tract with respiratory intensity and particle size was researched and compared. Furthermore, the more real inhalable particles with Rosin-Rammler mass distribution are used to study the effect of particles size. The deposition rate of particles with the different diameter scope in the different part of upper respiratory tract was summarized. The geometrical model based images technology promises to provide more real results of airflow field and particle deposition in the URT.

  15. 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

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

    International Nuclear Information System (INIS)

    Chugh, Brige P.; Quirk, Sarah; Conroy, Leigh; Smith, Wendy L.

    2014-01-01

    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

  17. Realistic modeling of the biological channel for the design of implantable wireless UWB communication systems.

    Science.gov (United States)

    Bahrami, Hadi; Gosselin, Benoit; Rusch, Leslie A

    2012-01-01

    Several emerging medical applications require that a miniature data acquisition device be implanted into the head to extract and wirelessly communicate brain activity to other devices. Designing a reliable communication link for such an application requires a realistic model of the surrounding biological tissues. This paper exploits a realistic model of the biological channel to design a suitable wireless ultra wideband communication link in a brain monitoring application. Two scenarios for positioning the implanted transmitting antenna are considered. The 1(st) scenario places the antenna under the skull, whereas the 2(nd) scenario places the antenna under the skin, above the skull. The propagation characteristics of the signal through the tissues of the human head have been determined with full-wave electromagnetic simulation based on Finite Element Method. The implantable antenna and the external antenna are key components to establish an electromagnetic link between an implanted transmitter and an external receiver. The average specific absorption rate (ASAR) of the implantable antennas are evaluated and compared for the two proposed scenarios. Moreover, the maximum available power from the implanted antenna is evaluated to characterize the performance of the communication link established between the implantable antenna and the external antenna, with respect to spectrum and safety regulations. We show how sensitive the receiver must be in order to implement a reliable telemetry link based on the proposed model of the channel.

  18. Realistic Paleobathymetry of the Cenomanian–Turonian (94 Ma Boundary Global Ocean

    Directory of Open Access Journals (Sweden)

    Arghya Goswami

    2018-01-01

    Full Text Available At present, global paleoclimate simulations are prepared with bathtub-like, flat, featureless and steep walled ocean bathymetry, which is neither realistic nor suitable. In this article, we present the first enhanced version of a reconstructed paleobathymetry for Cenomanian–Turonian (94 Ma time in a 0.1° × 0.1° resolution, that is both realistic and suitable for use in paleo-climate studies. This reconstruction is an extrapolation of a parameterized modern ocean bathymetry that combines simple geophysical models (standard plate cooling model for the oceanic lithosphere based on ocean crustal age, global modern oceanic sediment thicknesses, and generalized shelf-slope-rise structures calibrated from a published global relief model of the modern world (ETOPO1 at active and passive continental margins. The base version of this Cenomanian–Turonian paleobathymetry reconstruction is then updated with known submarine large igneous provinces, plateaus, and seamounts to minimize the difference between the reconstructed paleobathymetry and the real bathymetry that once existed.

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

    Science.gov (United States)

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

    2017-03-20

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

  20. Validation of CT brain perfusion methods using a realistic dynamic head phantom.

    Science.gov (United States)

    Riordan, Alan J; Prokop, Mathias; Viergever, Max A; Dankbaar, Jan Willem; Smit, Ewoud J; de Jong, Hugo W A M

    2011-06-01

    Development and evaluation of a realistic hybrid head phantom for the validation of quantitative CT brain perfusion 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 hybrid head phantom. Essential CT imaging parameters such as spatially dependent noise, effects of resolution, tube settings, and reconstruction parameters were intrinsically included by scanning a skull phantom using CT perfusion (CTP) protocols with varying mAs. These data were combined with processed high resolution 7T clinical MRI images to include healthy and diseased brain parenchyma, as well as the cerebral vascular system. Time attenuation curves emulating contrast bolus passage based on perfusion as observed in clinical studies were added. Using the phantom, CTP images were generated using three brain perfusion calculation methods: bcSVD, sSVD, and fit-based deconvolution, and the linearity and accuracy of the three calculation methods was assessed. Dependency of perfusion outcome on calculation method was compared to clinical data. Furthermore, the potential of the phantom to optimize brain perfusion packages was investigated. All perfusion calculation methods showed overestimation of low perfusion values and underestimation of high perfusion values. Good correlation in behavior between phantom and clinical data was found (R2 = 0.84). A dynamic hybrid head phantom constructed from CT and MRI data was demonstrated to realistically represent clinical CTP studies, which is useful for assessing CT brain perfusion acquisition, reconstruction, and analysis.

  1. Detailed performance analysis of realistic solar photovoltaic systems at extensive climatic conditions

    International Nuclear Information System (INIS)

    Gupta, Ankit; Chauhan, Yogesh K.

    2016-01-01

    In recent years, solar energy has been considered as one of the principle renewable energy source for electric power generation. In this paper, single diode photovoltaic (PV) system and double/bypass diode based PV system are designed in MATLAB/Simulink environment based on their mathematical modeling and are validated with a commercially available solar panel. The novelty of the paper is to include the effect of climatic conditions i.e. variable irradiation level, wind speed, temperature, humidity level and dust accumulation in the modeling of both the PV systems to represent a realistic PV system. The comprehensive investigations are made on both the modeled PV systems. The obtained results show the satisfactory performance for realistic models of the PV system. Furthermore, an in depth comparative analysis is carried out for both PV systems. - Highlights: • Modeling of Single diode and Double diode PV systems in MATLAB/Simulink software. • Validation of designed PV systems with a commercially available PV panel. • Acquisition and employment of key climatic factors in modeling of the PV systems. • Evaluation of main model parameters of both the PV systems. • Detailed comparative assessment of both the modeled PV system parameters.

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

    International Nuclear Information System (INIS)

    Stephenson, W.; Dutton, L.M.C.; Handy, B.J.; Smedley, C.

    1992-01-01

    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

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

    International Nuclear Information System (INIS)

    Ding Lei; Lai Yuan; He Bin

    2005-01-01

    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

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

    International Nuclear Information System (INIS)

    Panza, Giuliano F.; Alvarez, Leonardo; Aoudia, Abdelkrim

    2002-06-01

    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

  5. Radioactive waste management in Brazil: a realistic view

    International Nuclear Information System (INIS)

    Heilbron Filho, Paulo Fernando Lavalle; Perez Guerrero, Jesus Salvador; Xavier, Ana Maria

    2014-01-01

    The objective of this article is to present a realistic view of the main issues related to the management of radioactive waste in Brazil as well as a comprehensive picture of the regulatory waste management status in the country and internationally. Technical aspects that must be considered to ensure a safe construction of near surface disposal facilities for radioactive waste of low and medium levels of radiation are addressed. Different types of deposits, the basic regulatory issues involving the licensing of these facilities, the development of a financial compensation model for the Brazilian Municipalities where deposits are to be placed, the importance of the participation of the scientific community and society in the process of radioactive waste site selection and disposal, guidance for the application of the basic requirements of safety and radiation protection, the general safety aspects involved and the current actions for the disposal of radioactive waste in Brazil are highlighted. (author)

  6. Human Hibernation for Space Flight - Utopistic Vision or Realistic Possibility

    Science.gov (United States)

    Singer, D.

    Slowing-down the ageing process and prolongation of our life-times have been dreams of mankind for a very long time. Nowadays, in the age of expeditions to space, reduction of energetic needs has become a more practical goal, as it could help in the exploration of extraterrestrial destinations which otherwise, due to their huge distance away from earth and to the insufficient velocity of space vehicles, would be out of human reach [1]. Even though this might seem somewhat utopistic, the new goal gives reason to reconsider the current knowledge on metabolic reduction in nature and to adopt a realistic view of the degree of hypometabolism which might be achievable in humans. In the following, two aspects of this problem will be reviewed: first, the theoretical (biological) position of human adults among hibernating and non- hibernating mammals, and second, the practical (clinical) attempts to make humans hypometabolic.

  7. Radioactive waste management in Brazil: a realistic view

    Energy Technology Data Exchange (ETDEWEB)

    Heilbron Filho, Paulo Fernando Lavalle; Perez Guerrero, Jesus Salvador, E-mail: paulo@cnen.gov.br, E-mail: jperez@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Xavier, Ana Maria, E-mail: axavier@cnen.gov.br [Comissao Nacional de Energia Nuclear (ESPOA/CNEN-RS), Porto Alegre, RS (Brazil)

    2014-07-01

    The objective of this article is to present a realistic view of the main issues related to the management of radioactive waste in Brazil as well as a comprehensive picture of the regulatory waste management status in the country and internationally. Technical aspects that must be considered to ensure a safe construction of near surface disposal facilities for radioactive waste of low and medium levels of radiation are addressed. Different types of deposits, the basic regulatory issues involving the licensing of these facilities, the development of a financial compensation model for the Brazilian Municipalities where deposits are to be placed, the importance of the participation of the scientific community and society in the process of radioactive waste site selection and disposal, guidance for the application of the basic requirements of safety and radiation protection, the general safety aspects involved and the current actions for the disposal of radioactive waste in Brazil are highlighted. (author)

  8. Realistic finite temperature simulations of magnetic systems using quantum statistics

    Science.gov (United States)

    Bergqvist, Lars; Bergman, Anders

    2018-01-01

    We have performed realistic atomistic simulations at finite temperatures using Monte Carlo and atomistic spin dynamics simulations incorporating quantum (Bose-Einstein) statistics. The description is much improved at low temperatures compared to classical (Boltzmann) statistics normally used in these kind of simulations, while at higher temperatures the classical statistics are recovered. This corrected low-temperature description is reflected in both magnetization and the magnetic specific heat, the latter allowing for improved modeling of the magnetic contribution to free energies. A central property in the method is the magnon density of states at finite temperatures, and we have compared several different implementations for obtaining it. The method has no restrictions regarding chemical and magnetic order of the considered materials. This is demonstrated by applying the method to elemental ferromagnetic systems, including Fe and Ni, as well as Fe-Co random alloys and the ferrimagnetic system GdFe3.

  9. From Minimal to Realistic Supersymmetric SU(5) Grand Unification

    CERN Document Server

    Altarelli, Guido; Masina, I; Altarelli, Guido; Feruglio, Ferruccio; Masina, Isabella

    2000-01-01

    We construct and discuss a "realistic" example of SUSY SU(5) GUT model, with an additional U(1) flavour symmetry, that is not plagued by the need of large fine tunings, like those associated with doublet-triplet splitting in the minimal model, and that leads to an acceptable phenomenology. This includes coupling unification with a value of alpha_s(m_Z) in much better agreement with the data than in the minimal version, an acceptable hierarchical pattern for fermion masses and mixing angles, also including neutrino masses and mixings, and a proton decay rate compatible with present limits (but the discovery of proton decay should be within reach of the next generation of experiments). In the neutrino sector the preferred solution is one with nearly maximal mixing both for atmospheric and solar neutrinos.

  10. Realistic electrostatic potentials in a neutron star crust

    International Nuclear Information System (INIS)

    Ebel, Claudio; Mishustin, Igor; Greiner, Walter

    2015-01-01

    We study the electrostatic properties of inhomogeneous nuclear matter which can be formed in the crusts of neutron stars or in supernova explosions. Such matter is represented by Wigner–Seitz cells of different geometries (spherical, cylindrical, cartesian), which contain nuclei, free neutrons and electrons under the conditions of electrical neutrality. Using the Thomas–Fermi approximation, we have solved the Poisson equation for the electrostatic potential and calculated the corresponding electron density distributions in individual cells. The calculations are done for different shapes and sizes of the cells and different average baryon densities. The electron-to-baryon fraction was fixed at 0.3. Using realistic electron distributions leads to a significant reduction in electrostatic energy and electron chemical potential. (paper)

  11. 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...... spatial audio in three dimensions. However, practical constraints limit the number of microphones that can be used and thus the maximum spatial resolution and frequency bandwidth that can be achieved. Further, most important sound sources are near the horizontal plane, where human spatial hearing is also...... most accurate. This thesis therefore investigated whether the horizontal performance of spherical microphone arrays could be improved (i) through an appropriate placement of a fixed number of transducers on the sphere, and (ii) by applying mixed-order ambisonics (MOA) processing. MOA combines higher...

  12. 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.

  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

    ICIC configuration leads to modest gains, whereas the set of proposed fast dynamic eICIC algorithms result in capacity gains on the order of 35-120% depending on the local environment characteristics. These attractive gains together with the simplicity of the proposed solutions underline the practical relevance...... 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...... 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. Supersymmetry and light quark masses in a realistic superstring model

    International Nuclear Information System (INIS)

    Halyo, Edi.

    1993-10-01

    We examine the light quark masses in a standard-like superstring model in the four dimensional free fermionic formulation. We find that the supersymmetry constraints in the observable and hidden sectors eliminate all large contributions to m u and m d and force them to be much smaller than the other quark masses. The requirement for an acceptable Higgs doublet spectrum results in m u d . In these models a realistic m d can always be obtained whereas m u is at most 10 -5 MeV. For particular choices on flat direction or vacua m u can be as small as 10 -7 MeV but cannot vanish. (author) 15 refs, 2 tabs

  15. Realistic 3D resistive MHD calculations on the CRAY-1

    International Nuclear Information System (INIS)

    Hicks, H.R.; Carreras, B.

    1979-01-01

    CPU times for nonlinear resistive MHD calculations are very strongly dependent on the input variables. Although some regions of parameter space can be studied very cheaply, the conditions that correspond to Tokamak plasmas are extremely time consuming to study. Unfortunately, it is not possible to extrapolate reliably from the easy cases to the interesting regime. In recent years we have improved the efficiency of our codes by two orders of magnitude. As a result it is now feasible for us to run some realistic Tokamak cases on a CDC 7600. An additional factor of four reduction in run time is obtained by going to the CRAY-1 where the most time consuming routines are vectorized. This last factor makes a program of systematic studies feasible

  16. Magnetic exchange at realistic CoO/Ni interfaces

    KAUST Repository

    Grytsiuk, Sergii

    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.

  17. Recovering the quantum formalism from physically realist axioms

    Science.gov (United States)

    Auffèves, Alexia; Grangier, Philippe

    2017-03-01

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

  18. Realistic limitations of detecting planets around young active stars

    Directory of Open Access Journals (Sweden)

    Pinfield D.

    2013-04-01

    Full Text Available Current planet hunting methods using the radial velocity method are limited to observing middle-aged main-sequence stars where the signatures of stellar activity are much less than on young stars that have just arrived on the main-sequence. In this work we apply our knowledge from the surface imaging of these young stars to place realistic limitations on the possibility of detecting orbiting planets. In general we find that the magnitude of the stellar jitter is directly proportional to the stellar vsini. For G and K dwarfs, we find that it is possible, for models with high stellar activity and low stellar vsini, to be able to detect a 1 MJupiter mass planet within 50 epochs of observations and for the M dwarfs it is possible to detect a habitable zone Earth-like planet in 10s of observational epochs.

  19. Realistic Chest Tube Simulator Using Pork Belly with Skin

    Directory of Open Access Journals (Sweden)

    Donald Patrick Mebust

    2017-07-01

    Full Text Available Audience: The pork belly chest tube simulator is designed to instruct Emergency Medicine residents and Emergency Medicine-bound students. Introduction: Chest tube insertion is an essential procedural skill that must be mastered by practicing emergency and surgical providers. It is a lifesaving procedure indicated in cases of pneumothorax, hemothorax, chylothorax, empyema, esophageal/gastric rupture into the pleural space, and traumatic arrest.1,2 These critical patients require immediate decompression and evacuation of pleural space pathology. Therefore, chest tube insertion must be performed competently and expeditiously to prevent further morbidity and mortality. Performed improperly, chest tube placement can lead to ineffective decompression as well as life threatening visceral and vascular injury. Overall complications rates have been quoted up to 37%.3,4 Simulation offers a safe and effective method to master such procedural techniques. Unfortunately, many chest tube simulators are expensive5 or do not offer a realistic simulation experience. Therefore, we have designed an economical device that has a life-like feel, very similar to human skin and tissue. Objective: The purpose of this model is to teach residents and students how to competently perform and properly secure a surgical chest tube. Methods: This chest tube simulator uses a piece of pork belly that includes skin with underlying muscle and fascia. This tissue is placed over wooden strips and foam tape which are a proxy for human ribs and pleura. This chest wall anatomy allows the learner to locate landmarks, palpate intercostal spaces on real skin, and perform blunt dissection with a realistic “pop” of pleural tissue. Finally, since chest tube dislodgment is a common and unfortunate cause of morbidity and mortality, this chest wall design allows the learner to practice the essential and various techniques of securing the chest tube to real skin.

  20. Gyrokinetic Simulation of Tokamak Turbulence and Transport in Realistic Geometry.

    Science.gov (United States)

    Furnish, Geoffrey Mark

    Computational modelling of fusion plasmas is very resource intensive, so much so that the Numerical Tokamak Project has recently been recognized as a Grand Challenge of high performance computing. In order to apply computational modelling to the analysis of fusion plasma performance and eventually to attain predictive capability, an increasing emphasis on sophisticated algorithms and computational performance is required. In this work, an advanced three dimensional particle simulation code was developed, supporting simulations in realistic machine geometries, including both toroidal topology and shaping in the cross section. Gyrokinetic ions are employed in order to approach realistic tokamak parameter regimes. The code employs an object-oriented design supporting flexible, run-time selection of interchangeable components, including geometry model, particle dynamics, field solution strategy, grid configuration, etc. The code is designed for efficient, scalable execution on massively parallel computers, using an object-oriented wrapper over conventional message passing as the parallelization technology, and supports execution on uniprocessors as a limiting case. Simulations of tokamak turbulence and transport were performed. Toroidicity was seen to cause coupling of poloidal modes, resulting in the formation of a mode that is of global radial extent. The resultant transport was significantly elevated over that in cylindrical geometry, and moreover, exhibits a functional form increasing with radius, bearing significant similarity to experiment. The ion pressure gradient driven mode was studied to determine scaling of transport with the critical parameter a/rho_{i}. Runs were performed with eta_{i} = 4 over the range 70 <=q a/rho _{i} <=q 540, providing a computational picture of this mode extending well into the operating regime of current and future tokamaks. The ion thermal diffusivity chi_{i } was seen to possess Bohm-like scaling features.

  1. Toward ecologically realistic predictions of species distributions: A cross-time example from tropical montane cloud forests.

    Science.gov (United States)

    Guevara, Lázaro; Gerstner, Beth E; Kass, Jamie M; Anderson, Robert P

    2018-04-01

    There is an urgent need for more ecologically realistic models for better predicting the effects of climate change on species' potential geographic distributions. Here we build ecological niche models using MAXENT and test whether selecting predictor variables based on biological knowledge and selecting ecologically realistic response curves can improve cross-time distributional predictions. We also evaluate how the method chosen for extrapolation into nonanalog conditions affects the prediction. We do so by estimating the potential distribution of a montane shrew (Mammalia, Soricidae, Cryptotis mexicanus) at present and the Last Glacial Maximum (LGM). Because it is tightly associated with cloud forests (with climatically determined upper and lower limits) whose distributional shifts are well characterized, this species provides clear expectations of plausible vs. implausible results. Response curves for the MAXENT model made using variables selected via biological justification were ecologically more realistic compared with those of the model made using many potential predictors. This strategy also led to much more plausible geographic predictions for upper and lower elevational limits of the species both for the present and during the LGM. By inspecting the modeled response curves, we also determined the most appropriate way to extrapolate into nonanalog environments, a previously overlooked factor in studies involving model transfer. This study provides intuitive context for recommendations that should promote more realistic ecological niche models for transfer across space and time. © 2017 John Wiley & Sons Ltd.

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

    International Nuclear Information System (INIS)

    Mailhe, P.; Barbier, B.; Garnier, C.; Landskron, H.; Sedlacek, R.; Arimescu, I.; Smith, M.; Bellanger, P.

    2013-01-01

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

    Science.gov (United States)

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

    2014-06-01

    Realist review has increased in popularity as a methodology for complex intervention assessment. Our experience suggests that the process of designing a realist review requires its customization to areas under investigation. To elaborate on this idea, we first describe the logic underpinning realist review and then present critical reflections on our application experience, organized in seven areas. These are the following: (1) the challenge of identifying middle range theory; (2) addressing heterogeneity and lack of conceptual clarity; (3) the challenge of appraising the quality of complex evidence; (4) the relevance of capturing unintended outcomes; (5) understanding the process of context, mechanism, and outcome (CMO) configuring; (6) incorporating middle-range theory in the CMO configuration process; and (7) using middle range theory to advance the conceptualization of outcomes - both visible and seemingly 'hidden'. One conclusion from our experience is that the degree of heterogeneity of the evidence base will determine whether theory can drive the development of review protocols from the outset, or will follow only after an intense period of data immersion. We hope that presenting a critical reflection on customizing realist review will convey how the methodology can be tailored to the often complex and idiosyncratic features of health research, leading to innovative evidence syntheses. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Satisfaction and sustainability: a realist review of decentralized models of perinatal surgery for rural women.

    Science.gov (United States)

    Kornelsen, Jude; McCartney, Kevin; Williams, Kim

    2016-01-01

    This article was developed as part of a larger realist review investigating the viability and efficacy of decentralized models of perinatal surgical services for rural women in the context of recent and ongoing service centralization witnessed in many developed nations. The larger realist review was commissioned by the British Columbia Ministry of Health and Perinatal Services of British Columbia, Canada. Findings from that review are addressed in this article specific to the sustainability of rural perinatal surgical sites and the satisfaction of providers that underpins their recruitment to and retention at such sites. A realist method was used in the selection and analysis of literature with the intention to iteratively develop a sophisticated understanding of how perinatal surgical services can best meet the needs of women who live in rural and remote environments. The goal of a realist review is to examine what works for whom under what circumstances and why. The high sensitivity search used language (English) and year (since 1990) limiters in keeping with both a realist and rapid review tradition of using reasoned contextual boundaries. No exclusions were made based on methodology or methodological approach in keeping with a realist review. Databases searched included MEDLINE, PubMed, EBSCO, CINAHL, EBM Reviews, NHS Economic Evaluation Database and PAIS International for literature in December 2013. Database searching produced 103 included academic articles. A further 59 resources were added through pearling and 13 grey literature reports were added on recommendation from the commissioner. A total of 42 of these 175 articles were included in this article as specific to provider satisfaction and service sustainability. Operative perinatal practice was found to be a lynchpin of sustainable primary and surgical services in rural communities. Rural shortages of providers, including challenges with recruitment and retention, were found to be a complex issue, with

  5. Can complex health interventions be evaluated using routine clinical and administrative data? - a realist evaluation approach.

    Science.gov (United States)

    Riippa, Iiris; Kahilakoski, Olli-Pekka; Linna, Miika; Hietala, Minni

    2014-12-01

    Interventions aimed at improving chronic care typically consist of multiple interconnected parts, all of which are essential to the effect of the intervention. Limited attention has been paid to the use of routine clinical and administrative data in the evolution of these complex interventions. The purpose of this study is to examine the feasibility of routinely collected data when evaluating complex interventions and to demonstrate how a theory-based, realist approach to evaluation may increase the feasibility of routine data. We present a case study of evaluating a complex intervention, namely, the chronic care model (CCM), in Finnish primary health care. Issues typically faced when evaluating the effects of a complex intervention on health outcomes and resource use are identified by using routine data in a natural setting, and we apply context-mechanism-outcome (CMO) approach from the realist evaluation paradigm to improve the feasibility of using routine data in evaluating complex interventions. From an experimentalist approach that dominates the medical literature, routine data collected from a single centre offered a poor starting point for evaluating complex interventions. However, the CMO approach offered tools for identifying indicators needed to evaluate complex interventions. Applying the CMO approach can aid in a typical evaluation setting encountered by primary care managers: one in which the intervention is complex, the primary data source is routinely collected clinical and administrative data from a single centre, and in which randomization of patients into two research arms is too resource consuming to arrange. © 2014 John Wiley & Sons, Ltd.

  6. Time-scale invariance as an emergent property in a perceptron with realistic, noisy neurons.

    Science.gov (United States)

    Buhusi, Catalin V; Oprisan, Sorinel A

    2013-05-01

    In most species, interval timing is time-scale invariant: errors in time estimation scale up linearly with the estimated duration. In mammals, time-scale invariance is ubiquitous over behavioral, lesion, and pharmacological manipulations. For example, dopaminergic drugs induce an immediate, whereas cholinergic drugs induce a gradual, scalar change in timing. Behavioral theories posit that time-scale invariance derives from particular computations, rules, or coding schemes. In contrast, we discuss a simple neural circuit, the perceptron, whose output neurons fire in a clockwise fashion based on the pattern of coincidental activation of its input neurons. We show numerically that time-scale invariance emerges spontaneously in a perceptron with realistic neurons, in the presence of noise. Under the assumption that dopaminergic drugs modulate the firing of input neurons, and that cholinergic drugs modulate the memory representation of the criterion time, we show that a perceptron with realistic neurons reproduces the pharmacological clock and memory patterns, and their time-scale invariance, in the presence of noise. These results suggest that rather than being a signature of higher order cognitive processes or specific computations related to timing, time-scale invariance may spontaneously emerge in a massively connected brain from the intrinsic noise of neurons and circuits, thus providing the simplest explanation for the ubiquity of scale invariance of interval timing. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. The energy flux of MHD wave modes excited by realistic photospheric drivers

    Science.gov (United States)

    Fedun, Viktor; Von Fay-Siebenburgen, Erdélyi Robert; Mumford, Stuart

    The mechanism(s) responsible for solar coronal heating are still an unresolved and challenging task. In the framework of 3D numerical modelling of MHD wave excitation and propagation in the strongly stratified solar atmosphere we analyse the mode coupling and estimate the wave energy partition which can be supplied to the upper layers of the solar atmosphere by locally decomposed slow, fast and Alfven modes. These waves are excited by a number of realistic photospheric drivers which are mimicking the random granular buffeting, the coherent global solar oscillations and swirly motion observed in e.g. magnetic bright points. Based on a self-similar approach, a realistic magnetic flux tubes configuration is constructed and implemented in the VALIIIC model of the solar atmosphere. A novel method for decomposing the velocity perturbations into parallel, perpendicular and azimuthal components in 3D geometry is developed using field lines to trace a volume of constant energy flux. This method is used to identify the excited wave modes propagating upwards from the photosphere and to compute the percentage energy contribution of each mode. We have found, that for all cases where torsional motion is present, the main contribution to the flux (60%) is by Alfven wave. In the case of the vertical driver it is found to mainly excite the fast- and slow-sausage modes and a horizontal driver primarily excites the slow kink mode.

  8. Multimedia psychoeducational interventions to support patient self-care in degenerative conditions: A realist review.

    Science.gov (United States)

    O'Halloran, Peter; Scott, David; Reid, Joanne; Porter, Sam

    2015-10-01

    Multimedia interventions are increasingly used to deliver information in order to promote self-care among patients with degenerative conditions. We carried out a realist review of the literature to investigate how the characteristics of multimedia psychoeducational interventions combine with the contexts in which they are introduced to help or hinder their effectiveness in supporting self-care for patients with degenerative conditions. Electronic databases (Medline, Science Direct, PSYCHinfo, EBSCO, and Embase) were searched in order to identify papers containing information on multimedia psychoeducational interventions. Using a realist review approach, we reviewed all relevant studies to identify theories that explained how the interventions work. Ten papers were included in the review. All interventions sought to promote self-care behaviors among participants. We examined the development and content of the multimedia interventions and the impact of patient motivation and of the organizational context of implementation. We judged seven studies to be methodologically weak. All completed studies showed small effects in favor of the intervention. Multimedia interventions may provide high-quality information in an accessible format, with the potential to promote self-care among patients with degenerative conditions, if the patient perceives the information as important and develops confidence about self-care. The evidence base is weak, so that research is needed to investigate effective modes of delivery at different resource levels. We recommend that developers consider how an intervention will reduce uncertainty and increase confidence in self-care, as well as the impact of the context in which it will be employed.

  9. Accurate transfer maps for realistic beam-line elements: Straight elements

    Directory of Open Access Journals (Sweden)

    Chad E. Mitchell

    2010-06-01

    Full Text Available The behavior of orbits in charged-particle beam transport systems, including both linear and circular accelerators as well as final focus sections and spectrometers, can depend sensitively on nonlinear fringe-field and high-order-multipole effects in the various beam-line elements. The inclusion of these effects requires a detailed and realistic model of the interior and fringe fields, including their high spatial derivatives. A collection of surface fitting methods has been developed for extracting this information accurately from three-dimensional field data on a grid, as provided by various three-dimensional finite-element field codes. Based on these realistic field models, Lie or other methods may be used to compute accurate design orbits and accurate transfer maps about these orbits. Part I of this work presents a treatment of straight-axis magnetic elements, while part II will treat bending dipoles with large sagitta. An exactly soluble but numerically challenging model field is used to provide a rigorous collection of performance benchmarks.

  10. GADEN: A 3D Gas Dispersion Simulator for Mobile Robot Olfaction in Realistic Environments

    Directory of Open Access Journals (Sweden)

    Javier Monroy

    2017-06-01

    Full Text Available This work presents a simulation framework developed under the widely used Robot Operating System (ROS to enable the validation of robotics systems and gas sensing algorithms under realistic environments. The framework is rooted in the principles of computational fluid dynamics and filament dispersion theory, modeling wind flow and gas dispersion in 3D real-world scenarios (i.e., accounting for walls, furniture, etc.. Moreover, it integrates the simulation of different environmental sensors, such as metal oxide gas sensors, photo ionization detectors, or anemometers. We illustrate the potential and applicability of the proposed tool by presenting a simulation case in a complex and realistic office-like environment where gas leaks of different chemicals occur simultaneously. Furthermore, we accomplish quantitative and qualitative validation by comparing our simulated results against real-world data recorded inside a wind tunnel where methane was released under different wind flow profiles. Based on these results, we conclude that our simulation framework can provide a good approximation to real world measurements when advective airflows are present in the environment.

  11. 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.

  12. Characteristics of 454 pyrosequencing data--enabling realistic simulation with flowsim.

    Science.gov (United States)

    Balzer, Susanne; Malde, Ketil; Lanzén, Anders; Sharma, Animesh; Jonassen, Inge

    2010-09-15

    The commercial launch of 454 pyrosequencing in 2005 was a milestone in genome sequencing in terms of performance and cost. Throughout the three available releases, average read lengths have increased to approximately 500 base pairs and are thus approaching read lengths obtained from traditional Sanger sequencing. Study design of sequencing projects would benefit from being able to simulate experiments. We explore 454 raw data to investigate its characteristics and derive empirical distributions for the flow values generated by pyrosequencing. Based on our findings, we implement Flowsim, a simulator that generates realistic pyrosequencing data files of arbitrary size from a given set of input DNA sequences. We finally use our simulator to examine the impact of sequence lengths on the results of concrete whole-genome assemblies, and we suggest its use in planning of sequencing projects, benchmarking of assembly methods and other fields. Flowsim is freely available under the General Public License from http://blog.malde.org/index.php/flowsim/.

  13. Developing workshop module of realistic mathematics education: Follow-up workshop

    Science.gov (United States)

    Palupi, E. L. W.; Khabibah, S.

    2018-01-01

    Realistic Mathematics Education (RME) is a learning approach which fits the aim of the curriculum. The success of RME in teaching mathematics concepts, triggering students’ interest in mathematics and teaching high order thinking skills to the students will make teachers start to learn RME. Hence, RME workshop is often offered and done. This study applied development model proposed by Plomp. Based on the study by RME team, there are three kinds of RME workshop: start-up workshop, follow-up workshop, and quality boost. However, there is no standardized or validated module which is used in that workshops. This study aims to develop a module of RME follow-up workshop which is valid and can be used. Plopm’s developmental model includes materials analysis, design, realization, implementation, and evaluation. Based on the validation, the developed module is valid. While field test shows that the module can be used effectively.

  14. Convective aggregation in realistic convective-scale simulations

    Science.gov (United States)

    Holloway, Christopher E.

    2017-06-01

    To investigate the real-world relevance of idealized-model convective self-aggregation, five 15 day cases of real organized convection in the tropics are simulated. These include multiple simulations of each case to test sensitivities of the convective organization and mean states to interactive radiation, interactive surface fluxes, and evaporation of rain. These simulations are compared to self-aggregation seen in the same model configured to run in idealized radiative-convective equilibrium. Analysis of the budget of the spatial variance of column-integrated frozen moist static energy shows that control runs have significant positive contributions to organization from radiation and negative contributions from surface fluxes and transport, similar to idealized runs once they become aggregated. Despite identical lateral boundary conditions for all experiments in each case, systematic differences in mean column water vapor (CWV), CWV distribution shape, and CWV autocorrelation length scale are found between the different sensitivity runs, particularly for those without interactive radiation, showing that there are at least some similarities in sensitivities to these feedbacks in both idealized and realistic simulations (although the organization of precipitation shows less sensitivity to interactive radiation). The magnitudes and signs of these systematic differences are consistent with a rough equilibrium between (1) equalization due to advection from the lateral boundaries and (2) disaggregation due to the absence of interactive radiation, implying disaggregation rates comparable to those in idealized runs with aggregated initial conditions and noninteractive radiation. This points to a plausible similarity in the way that radiation feedbacks maintain aggregated convection in both idealized simulations and the real world.Plain Language SummaryUnderstanding the processes that lead to the organization of tropical rainstorms is an important challenge for weather

  15. Effective realistic interactions for low momentum Hilbert spaces

    International Nuclear Information System (INIS)

    Weber, Dennis

    2012-01-01

    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 described

  16. Factors influencing intercultural doctor-patient communication: a realist review.

    Science.gov (United States)

    Paternotte, Emma; van Dulmen, Sandra; van der Lee, Nadine; Scherpbier, Albert J J A; Scheele, Fedde

    2015-04-01

    Due to migration, doctors see patients from different ethnic backgrounds. This causes challenges for the communication. To develop training programs for doctors in intercultural communication (ICC), it is important to know which barriers and facilitators determine the quality of ICC. This study aimed to provide an overview of the literature and to explore how ICC works. A systematic search was performed to find literature published before October 2012. The search terms used were cultural, communication, healthcare worker. A realist synthesis allowed us to use an explanatory focus to understand the interplay of communication. In total, 145 articles met the inclusion criteria. We found ICC challenges due to language, cultural and social differences, and doctors' assumptions. The mechanisms were described as factors influencing the process of ICC and divided into objectives, core skills and specific skills. The results were synthesized in a framework for the development of training. The quality of ICC is influenced by the context and by the mechanisms. These mechanisms translate into practical points for training, which seem to have similarities with patient-centered communication. Training for improving ICC can be developed as an extension of the existing training for patient-centered communication. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  17. Urban renewal, gentrification and health equity: a realist perspective.

    Science.gov (United States)

    Mehdipanah, Roshanak; Marra, Giulia; Melis, Giulia; Gelormino, Elena

    2018-04-01

    Up to now, research has focused on the effects of urban renewal programs and their impacts on health. While some of this research points to potential negative health effects due to gentrification, evidence that addresses the complexity associated with this relation is much needed. This paper seeks to better understand when, why and how health inequities arise from urban renewal interventions resulting in gentrification. A realist review, a qualitative systematic review method, aimed to better explain the relation between context, mechanism and outcomes, was used. A literature search was done to identify theoretical models of how urban renewal programs can result in gentrification, which in turn could have negative impacts on health. A systematic approach was then used to identify peer-reviewed studies that provided evidence to support or refute the initial assumptions. Urban renewal programs that resulted in gentrification tended to have negative health effects primarily in residents that were low-income. Urban renewal policies that were inclusive of populations that are vulnerable, from the beginning were less likely to result in gentrification and more likely to positively impact health through physical and social improvements. Research has shown urban renewal policies have significant impacts on populations that are vulnerable and those that result in gentrification can result in negative health consequences for this population. A better understanding of this is needed to impact future policies and advocate for a community-participatory model that includes such populations in the early planning stages.

  18. Atomistic simulations of graphite etching at realistic time scales.

    Science.gov (United States)

    Aussems, D U B; Bal, K M; Morgan, T W; van de Sanden, M C M; Neyts, E C

    2017-10-01

    Hydrogen-graphite interactions are relevant to a wide variety of applications, ranging from astrophysics to fusion devices and nano-electronics. In order to shed light on these interactions, atomistic simulation using Molecular Dynamics (MD) has been shown to be an invaluable tool. It suffers, however, from severe time-scale limitations. In this work we apply the recently developed Collective Variable-Driven Hyperdynamics (CVHD) method to hydrogen etching of graphite for varying inter-impact times up to a realistic value of 1 ms, which corresponds to a flux of ∼10 20 m -2 s -1 . The results show that the erosion yield, hydrogen surface coverage and species distribution are significantly affected by the time between impacts. This can be explained by the higher probability of C-C bond breaking due to the prolonged exposure to thermal stress and the subsequent transition from ion- to thermal-induced etching. This latter regime of thermal-induced etching - chemical erosion - is here accessed for the first time using atomistic simulations. In conclusion, this study demonstrates that accounting for long time-scales significantly affects ion bombardment simulations and should not be neglected in a wide range of conditions, in contrast to what is typically assumed.

  19. Uncovering gender discrimination cues in a realistic setting.

    Science.gov (United States)

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

    2009-02-10

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

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

    Directory of Open Access Journals (Sweden)

    František LÍZAL

    2010-12-01

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

  1. Towards realistic string vacua from branes at singularities

    Science.gov (United States)

    Conlon, Joseph P.; Maharana, Anshuman; Quevedo, Fernando

    2009-05-01

    We report on progress towards constructing string models incorporating both realistic D-brane matter content and moduli stabilisation with dynamical low-scale supersymmetry breaking. The general framework is that of local D-brane models embedded into the LARGE volume approach to moduli stabilisation. We review quiver theories on del Pezzo n (dPn) singularities including both D3 and D7 branes. We provide supersymmetric examples with three quark/lepton families and the gauge symmetries of the Standard, Left-Right Symmetric, Pati-Salam and Trinification models, without unwanted chiral exotics. We describe how the singularity structure leads to family symmetries governing the Yukawa couplings which may give mass hierarchies among the different generations. We outline how these models can be embedded into compact Calabi-Yau compactifications with LARGE volume moduli stabilisation, and state the minimal conditions for this to be possible. We study the general structure of soft supersymmetry breaking. At the singularity all leading order contributions to the soft terms (both gravity- and anomaly-mediation) vanish. We enumerate subleading contributions and estimate their magnitude. We also describe model-independent physical implications of this scenario. These include the masses of anomalous and non-anomalous U(1)'s and the generic existence of a new hyperweak force under which leptons and/or quarks could be charged. We propose that such a gauge boson could be responsible for the ghost muon anomaly recently found at the Tevatron's CDF detector.

  2. Realistic Hamiltonians for no-core moment method studies

    International Nuclear Information System (INIS)

    Vary, J.P.

    1980-01-01

    Motivated by the need to test the adequacy of realistic nucleon-nucleon potentials for yielding the dynamics of many-nucleon systems we develop effective Hamiltonians for large-space moment method studies. These Hamiltonians consist of the relative kinetic energy operator and an exact Brueckner G-matrix acting between all pairs of nucleons in the nucleus. That is, there is no core and the nuclear properties are obtained through moment methods as a function of the size of the model space. The primary initial emphasis is to obtain the binding energy and comparisons are made with results of the coupled-cluster or exp(s) calculations. We find a systematic but slow decrease in the importance of three and higher body effective forces as the model space is increased. The results with the Reid soft core interaction for the binding energy of 16 O appear to be converging close the the exp(s) results. Further tests of the moment methods themselves are indicated as well as the desirability of increasing still further the model space for the no-core studies

  3. Emulating Realistic Bidirectional Spatial Channels for MIMO OTA Testing

    Directory of Open Access Journals (Sweden)

    Wei Fan

    2015-01-01

    Full Text Available This paper discusses over the air (OTA testing for multiple input multiple output (MIMO capable terminals with emphasis on modeling bidirectional spatial channel models in multiprobe anechoic chamber (MPAC setups. In the literature, work on this topic has been mainly focused on how to emulate 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 the importance of emulating full bidirectional channel and proposing possible directions to implement uplink channels in the literature. Nevertheless, there is no currently published work reporting an experimental validation of such concepts. In this paper, a general framework to emulate bidirectional channels for time division duplexing (TDD and frequency division duplexing (FDD communication systems is proposed. The proposed technique works for MPAC setups with arbitrary uplink and downlink probe configurations, that is, possibly different probe configurations (e.g., number of probes or their 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.

  4. Steering Microbubbles in Physiologically Realistic Flows Using the Bjerknes Force

    Science.gov (United States)

    Clark, Alicia; Aliseda, Alberto

    2017-11-01

    Ultrasound contrast agents (UCAs) are lipid-coated microbubbles that are used to increase contrast in ultrasound imaging due to their ability to scatter sound. Additionally, UCAs can be used in conjunction with ultrasound in medical applications such as targeted drug delivery and thrombolysis. These applications utilize the Bjerknes force, an ultrasound-induced force caused by the phase difference between the incoming ultrasound pressure wave and the microbubble volume oscillations. The dynamics of microbubbles under ultrasound excitation have been studied thoroughly in stagnant fluid baths; however, understanding of the fundamental physics of microbubbles in physiologically realistic flows is lacking. An in vitroexperiment that reproduces the dynamics (Reynolds and Womersley numbers) of a medium-sized blood vessel was used to explore the behavior of microbubbles. Using Lagrangian tracking, the trajectory of each individual bubble was reconstructed using information obtained from high speed imaging. The balance of hydrodynamic forces (lift, drag, added mass, etc.) against the primary Bjerknes force was analyzed. The results show that an increase in ultrasound pulse repetition frequency leads to a linear increase in the Bjerknes force and the increase in the force is quadratic with the amplitude of the excitation.

  5. Improved calculation of synchrotron radiation losses in realistic tokamak plasmas

    International Nuclear Information System (INIS)

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

    2001-01-01

    Owing to the complexity of the exact calculation, synchrotron losses are usually estimated in system studies, with expressions derived from a plasma description using simplifying assumptions on the geometry, radiation absorption, and density and temperature profiles. In the present article, a complete formulation of the transport of synchrotron radiation is performed for realistic conditions of toroidal plasma geometry with elongated cross-section, using a quasi-exact method for the calculation of the absorption coefficients, and for arbitrary shapes of density and temperature profiles. The effects of toroidicity and temperature profile on synchrotron radiation losses are analysed in detail. In particular, when the electron temperature profile is almost flat in the plasma centre as, for example, in internal transport barrier 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 content. Such an effect is not included in presently used approximate expressions. As an illustration, it is shown that in the case of an advanced high temperature plasma envisaged for a steady state commercial reactor, synchrotron losses represent approximately 20% of the total losses, so that this term becomes significant in the power balance of such a plasma. Finally, the authors 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 is optimized for massively parallel computing. (author)

  6. Modelisation of synchrotron radiation losses in realistic tokamak plasmas

    International Nuclear Information System (INIS)

    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)

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

    Science.gov (United States)

    Drake, Jennifer E

    2014-11-01

    Some young children are able to create stunningly realistic drawings resembling those of adult artists. What perceptual abilities underlie this talent? This study examined two candidate skills on which adult artists excel: the ability to segment a complex form mentally (measured by the Block Design Task) and the ability to see hidden forms (measured by the Group Embedded Figures Test). Sixty-seven 6- to 13-year-olds with a wide range of drawing abilities completed these tasks as well as an IQ test and an observational drawing task. While children who scored high on drawing realism outperformed those who scored low in drawing realism on both perceptual tasks, only detection of embedded figures predicted drawing realism. This occurred independently of age, gender, years of training, and verbal and non-verbal IQ. There are certainly many contributors to this complex ability, but one component appears to be the tendency to see things more as they really are and thereby recognize the continuous contour of an object despite interference from other overlapping objects. © 2014 The British Psychological Society.

  8. Nonstandard Farey sequences in a realistic diode map

    International Nuclear Information System (INIS)

    Perez, G.; Sinha, S.; Cerdeira, H.

    1991-06-01

    We study a realistic coupled map system, modelling a p - i - n diode structure. As we vary the parameter corresponding to the (scaled) external potential in the model, the dynamics goes through a flip bifurcation and then a Hopf bifurcation, and as the parameter is increased further, we find evidence of a sequence of mode locked windows embedded in the quasiperiodic motion, with periodic attractors whose winding numbers p = p/q, are given by a Farey series. The interesting thing about this Farey sequence is that it is generated between two parent attractors with p = 2/7 and 2/8, where 2/8 implies two distinct coexisting attractors with p = 1/4, and the correct series is obtained only when we use parent winding number 2/8 and not 1/4. So unlike a regular Farey tree, p and q need not be relatively prime here, p = 2 x p/2 x q is permissible, where such attractors are actually comprised of two coexisting attractors with p = p/q. We also checked that the positions and widths of these windows exhibit well defined power law scaling. When the potential is increased further, the Farey windows still provide a ''skeleton'' for the dynamics, and within each window there is a host of other interesting dynamical features, including multiple forward and reverse Feigenbaum trees. (author). 15 refs, 7 figs

  9. Compiling quantum circuits to realistic hardware architectures using temporal planners

    Science.gov (United States)

    Venturelli, Davide; Do, Minh; Rieffel, Eleanor; Frank, Jeremy

    2018-04-01

    To run quantum algorithms on emerging gate-model quantum hardware, quantum circuits must be compiled to take into account constraints on the hardware. For near-term hardware, with only limited means to mitigate decoherence, it is critical to minimize the duration of the circuit. We investigate the application of temporal planners to the problem of compiling quantum circuits to newly emerging quantum hardware. While our approach is general, we focus on compiling to superconducting hardware architectures with nearest neighbor constraints. Our initial experiments focus on compiling Quantum Alternating Operator Ansatz (QAOA) circuits whose high number of commuting gates allow great flexibility in the order in which the gates can be applied. That freedom makes it more challenging to find optimal compilations but also means there is a greater potential win from more optimized compilation than for less flexible circuits. We map this quantum circuit compilation problem to a temporal planning problem, and generated a test suite of compilation problems for QAOA circuits of various sizes to a realistic hardware architecture. We report compilation results from several state-of-the-art temporal planners on this test set. This early empirical evaluation demonstrates that temporal planning is a viable approach to quantum circuit compilation.

  10. 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.

  11. 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.

  12. Providing oxygen to children in hospitals: a realist review.

    Science.gov (United States)

    Graham, Hamish; Tosif, Shidan; Gray, Amy; Qazi, Shamim; Campbell, Harry; Peel, David; McPake, Barbara; Duke, Trevor

    2017-04-01

    To identify and describe interventions to improve oxygen therapy in hospitals in low-resource settings, and to determine the factors that contribute to success and failure in different contexts. Using realist review methods, we scanned the literature and contacted experts in the field to identify possible mechanistic theories of how interventions to improve oxygen therapy systems might work. Then we systematically searched online databases for evaluations of improved oxygen systems in hospitals in low- or middle-income countries. We extracted data on the effectiveness, processes and underlying theory of selected projects, and used these data to test the candidate theories and identify the features of successful projects. We included 20 improved oxygen therapy projects (45 papers) from 15 countries. These used various approaches to improving oxygen therapy, and reported clinical, quality of care and technical outcomes. Four effectiveness studies demonstrated positive clinical outcomes for childhood pneumonia, with large variation between programmes and hospitals. We identified factors that help or hinder success, and proposed a practical framework depicting the key requirements for hospitals to effectively provide oxygen therapy to children. To improve clinical outcomes, oxygen improvement programmes must achieve good access to oxygen and good use of oxygen, which should be facilitated by a broad quality improvement capacity, by a strong managerial and policy support and multidisciplinary teamwork. Our findings can inform practitioners and policy-makers about how to improve oxygen therapy in low-resource settings, and may be relevant for other interventions involving the introduction of health technologies.

  13. Is the number of registered abortions in Serbia realistic?

    Directory of Open Access Journals (Sweden)

    Rašević Mirjana

    2008-01-01

    Full Text Available Ever since the 1990's the number of registered abortions in Serbia has been decreasing from year to year. Are the abortion data of the Public Health Institute complete? In other words, has there been a qualitative shift in the sphere of reproductive behavior of Serbia's population in the last two decades? This paper deals with the raised question in three ways. First, in an indirect way, by analyzing whether a radical change in birth control since the 1990's has been possible, having in mind the complexity of the abortion issue in Serbia, as well as the broad social context regarding the last decade of the last century and beginning of this one. The second way deals more directly with the quality of the official data on abortions. Namely, the great decrease in the number of induced abortions, theoretically observed, may be a consequence of the increased level of births, or possibly acceleration in the birth control transition from the use of traditional and inefficient contraception to the usage of modern and efficient methods and means for conception control. For this reason, population fertility trends were analyzed, with a special review on the time period from the 1990's till present day and the results of the available surveyed researches on the structure of contraception usage in order to determine whether objective assumptions exist for the decrease in the number of induced abortions or not. The third way to reach an answer to the raised question in the title was attempted by estimating the scope of induced abortions. In that sense, relevant literature was consulted and the Westoff method chosen for calculating the rate of total abortions in Serbia (excluding Kosovo and Metohia in the year 2006. After examining the set task from all three sides, there seemed to be no doubt that the official data on the number of abortions in Serbia are not realistic. The basic reason for incomplete official data on abortions seems to be the fact that in

  14. Realist evaluation of an enhanced health visiting programme.

    Science.gov (United States)

    Doi, Lawrence; Jepson, Ruth; Hardie, Samantha

    2017-01-01

    The health visitors' role in many countries is changing. In Scotland, the role has undergone substantial changes through the introduction of an enhanced health visiting programme, which includes increased, structured home visits. This evaluation was conducted within NHS Ayrshire and Arran, one of the 14 Scottish Health Boards. Our aim was to understand and explain how, and why, the programme could contribute to improving health and wellbeing outcomes for children and families. We used a realist evaluation approach, conducted in three phases. In phase one, eight managerial staff involved in developing and implementing the programme provided data, which were used to develop initial programme theories. In phase two, the programme theories were tested using qualitative data from 25 health visitors and 22 parents. The programme theories were refined through analyses and interpretation of data in phase three. The home visiting context provided by the programme interacted with the mechanisms of the programme and produced outcomes such as early identification of health and wellbeing issues amongst families who needed more support, leading to referral and engagement with sources of additional help. The home visits facilitated development of parent-health visitor relationships, and parents considered health visitors as their first point of contact on children's wellbeing and developmental-related issues. Moreover, the programme provided more clarity to health visitors' role, which in turn enhanced partnership working. However, there were aspects of the programme that may require further development. For instance, both parents and health visitors were concerned about the wide gaps between some home visits. The enhanced health visiting programme increased opportunities for monitoring and early identification of health and wellbeing concerns. It created structures for a more efficient partnership working and ensured that the needs of children and families were supported. These

  15. Development of Realistic Safety Analysis Technology for CANDU Reactors

    International Nuclear Information System (INIS)

    Park, Joo Hwan; Rhee, B. W.; Rho, G. H.

    2010-04-01

    The following 3 research items have been studied to develop and establish the realistic safety analysis and the associated technologies for a CANDU reactor. At the first, WIMS-CANDU which is physics cell code for a CANDU has been improved and validated against the physics criticality experiment data transferred through the international cooperation programs. Also an improved physics model to take into account the pressure tube creep was developed and utilized to assess the effects of the pressure tube creep of 0%, 2.5% and 5% diametral increase of pressure tube on core physics parameters. Secondly, the interfacing module between physics and thermal-hydraulics codes has been developed to provide the enhancement of reliability and convenience of the calculation results of the physics parameters such as power coefficient which was calculated by independent code systems. Finally, the important parameters related to the complex heat transfer mechanisms in the crept pressure tubes were identified to find how to improve the existing fuel channel models. One of the important parameters such as the oxidation model of Zr-steam reaction was identified, implemented and verified with the experimental data of the high pressure and temperature fuel channel and its model was utilized for CFD analysis of the crept pressure tube effect on the reactor safety. The results were also provided to validate the CATNENA models of the crept pressure tube and the effects of the pressure tube creep on the blowdown and post-blowdown phase during LOCA was assessed. The results of this study can be used to assess the uncertainty analysis of coolant void reactivity and the effects of the creep deformed pressure tubes on physics/TH/safety issues. Also, those results will be used to improve the current design and operational safety analysis codes, and to technically support the related issues to resolve their problems

  16. Coil optimisation for transcranial magnetic stimulation in realistic head geometry.

    Science.gov (United States)

    Koponen, Lari M; Nieminen, Jaakko O; Mutanen, Tuomas P; Stenroos, Matti; Ilmoniemi, Risto J

    Transcranial magnetic stimulation (TMS) allows focal, non-invasive stimulation of the cortex. A TMS pulse is inherently weakly coupled to the cortex; thus, magnetic stimulation requires both high current and high voltage to reach sufficient intensity. These requirements limit, for example, the maximum repetition rate and the maximum number of consecutive pulses with the same coil due to the rise of its temperature. To develop methods to optimise, design, and manufacture energy-efficient TMS coils in realistic head geometry with an arbitrary overall coil shape. We derive a semi-analytical integration scheme for computing the magnetic field energy of an arbitrary surface current distribution, compute the electric field induced by this distribution with a boundary element method, and optimise a TMS coil for focal stimulation. Additionally, we introduce a method for manufacturing such a coil by using Litz wire and a coil former machined from polyvinyl chloride. We designed, manufactured, and validated an optimised TMS coil and applied it to brain stimulation. Our simulations indicate that this coil requires less than half the power of a commercial figure-of-eight coil, with a 41% reduction due to the optimised winding geometry and a partial contribution due to our thinner coil former and reduced conductor height. With the optimised coil, the resting motor threshold of abductor pollicis brevis was reached with the capacitor voltage below 600 V and peak current below 3000 A. The described method allows designing practical TMS coils that have considerably higher efficiency than conventional figure-of-eight coils. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Demonstrating correction of low levels of astigmatism with realistic scenes.

    Science.gov (United States)

    Milton, Andy; Murphy, Michael; Rose, Ben; Olivares, Giovanna; Little, Borm Kim; Lau, Charis; Sulley, Anna

    2016-02-01

    Modern standard visual acuity tests are primarily designed as diagnostic tools for use during subjective refraction and normally bear little relation to real-world situations. We have developed a methodology to create realistic rendered scenes that demonstrate potential vision improvement in a relevant and engaging way. Low-cylindrical refractive error can be made more noticeable by optimizing the contrast and spatial frequencies, and by testing four different visual perception skills: motion tracking, pattern recognition, visual clutter differentiation and contrast sensitivity. Using a 1.00DC lens during iteration, we created a range of still and video scenes before optimizing to a selection 3-D rendered street scenes. These were assessed on everyday relevance, emotional and visual engagement and sensitivity to refractive correction for low-cylinder astigmats (0.75-1.00DC, n=74) wearing best spherical equivalent correction and then with astigmatism corrected. The most promising visual elements involved or combined optimized textures, distracting patterns behind text, faces at a distance, and oblique text. 91.9% of subjects (95% CI: 83.2, 97.0) reported an overall visual improvement when viewing the images with astigmatic correction, and 96% found the images helpful to determine which type of contact lens to use. Our method, which combines visual science with design thinking, takes a new approach to creating vision tests. The resultant test scenes can be used to improve patient interaction and help low cylinder astigmats see relevant, every-day benefits in correcting low levels (0.75 & 1.00DC) of astigmatism. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Realistic phantoms to characterize dosimetry in pediatric CT

    Energy Technology Data Exchange (ETDEWEB)

    Carver, Diana E.; Kost, Susan D.; Fraser, Nicholas D.; Pickens, David R.; Price, Ronald R.; Stabin, Michael G. [Vanderbilt University Medical Center, Department of Radiology and Radiological Sciences, Nashville, TN (United States); Segars, W.P. [Duke University, Carl E. Ravin Advanced Imaging Laboratories, Durham, NC (United States)

    2017-05-15

    The estimation of organ doses and effective doses for children receiving CT examinations is of high interest. Newer, more realistic anthropomorphic body models can provide information on individual organ doses and improved estimates of effective dose. Previously developed body models representing 50th-percentile individuals at reference ages (newborn, 1, 5, 10 and 15 years) were modified to represent 10th, 25th, 75th and 90th height percentiles for both genders and an expanded range of ages (3, 8 and 13 years). We calculated doses for 80 pediatric reference phantoms from simulated chest-abdomen-pelvis exams on a model of a Philips Brilliance 64 CT scanner. Individual organ and effective doses were normalized to dose-length product (DLP) and fit as a function of body diameter. We calculated organ and effective doses for 80 reference phantoms and plotted them against body diameter. The data were well fit with an exponential function. We found DLP-normalized organ dose to correlate strongly with body diameter (R{sup 2}>0.95 for most organs). Similarly, we found a very strong correlation with body diameter for DLP-normalized effective dose (R{sup 2}>0.99). Our results were compared to other studies and we found average agreement of approximately 10%. We provide organ and effective doses for a total of 80 reference phantoms representing normal-stature children ranging in age and body size. This information will be valuable in replacing the types of vendor-reported doses available. These data will also permit the recording and tracking of individual patient doses. Moreover, this comprehensive dose database will facilitate patient matching and the ability to predict patient-individualized dose prior to examination. (orig.)

  19. Realistic modelling of observed seismic motion in complex sedimentary basins

    International Nuclear Information System (INIS)

    Faeh, D.; Panza, G.F.

    1994-03-01

    Three applications of a numerical technique are illustrated to model realistically the seismic ground motion for complex two-dimensional structures. First we consider a sedimentary basin in the Friuli region, and we model strong motion records from an aftershock of the 1976 earthquake. Then we simulate the ground motion caused in Rome by the 1915, Fucino (Italy) earthquake, and we compare our modelling with the damage distribution observed in the town. Finally we deal with the interpretation of ground motion recorded in Mexico City, as a consequence of earthquakes in the Mexican subduction zone. The synthetic signals explain the major characteristics (relative amplitudes, spectral amplification, frequency content) of the considered seismograms, and the space distribution of the available macroseismic data. For the sedimentary basin in the Friuli area, parametric studies demonstrate the relevant sensitivity of the computed ground motion to small changes in the subsurface topography of the sedimentary basin, and in the velocity and quality factor of the sediments. The total energy of ground motion, determined from our numerical simulation in Rome, is in very good agreement with the distribution of damage observed during the Fucino earthquake. For epicentral distances in the range 50km-100km, the source location and not only the local soil conditions control the local effects. For Mexico City, the observed ground motion can be explained as resonance effects and as excitation of local surface waves, and the theoretical and the observed maximum spectral amplifications are very similar. In general, our numerical simulations permit the estimate of the maximum and average spectral amplification for specific sites, i.e. are a very powerful tool for accurate micro-zonation. (author). 38 refs, 19 figs, 1 tab

  20. Linear gyrokinetic investigation of the geodesic acoustic modes in realistic tokamak configurations

    Science.gov (United States)

    Novikau, I.; Biancalani, A.; Bottino, A.; Conway, G. D.; Gürcan, Ö. D.; Manz, P.; Morel, P.; Poli, E.; di Siena, A.; ASDEX Upgrade Team

    2017-12-01

    In order to provide scaling formulae for the geodesic acoustic mode (GAM) frequency and damping rate, GAMs are studied by means of the gyrokinetic global particle-in-cell code ORB5. Linear electromagnetic simulations in the low-βe limit have been performed in order to separate acoustic and Alfvénic time scales and obtain more accurate measurements. The dependence of the frequency and damping rate on several parameters such as the safety factor, the GAM radial wavenumber, and the plasma elongation is studied. All simulations have been performed with kinetic electrons with a realistic electron/ion mass ratio. Interpolating formulae for the GAM frequency and damping rate, based on the results of the gyrokinetic simulations, have been derived. Using these expressions, the influence of the temperature gradient on the damping rate is also investigated. Finally, the results are applied to the study of a real discharge of the ASDEX Upgrade tokamak.

  1. Realistic effective interactions for the sd shell: Global and discrete nuclear properties

    International Nuclear Information System (INIS)

    Dalton, B.J.; Baldridge, W.J.; Vary, J.P.

    1979-01-01

    Comparisons of the Kuo and Vary-Yang sd shell realistic effective shell-model interactions are presented through studies of the resulting global and discrete nuclear properties. The methods of spectral distributions are used to obtain energy moments for 21 Ne and spin cutoff factors for 28 Si for each interaction. Shell-model spectra are presented for some mass A = 18 to A = 21 sd shell nuclei. In each case we show for comparison the results using the Chung-Wildenthal empirical interaction. In addition to demonstrating the role of various approximations through resulting global and discrete properties, we show that certain conclusions drawn from global properties are consistent with those based upon discrete properties

  2. Characterization of photomultiplier tubes with a realistic model through GPU-boosted simulation

    Science.gov (United States)

    Anthony, M.; Aprile, E.; Grandi, L.; Lin, Q.; Saldanha, R.

    2018-02-01

    The accurate characterization of a photomultiplier tube (PMT) is crucial in a wide-variety of applications. However, current methods do not give fully accurate representations of the response of a PMT, especially at very low light levels. In this work, we present a new and more realistic model of the response of a PMT, called the cascade model, and use it to characterize two different PMTs at various voltages and light levels. The cascade model is shown to outperform the more common Gaussian model in almost all circumstances and to agree well with a newly introduced model independent approach. The technical and computational challenges of this model are also presented along with the employed solution of developing a robust GPU-based analysis framework for this and other non-analytical models.

  3. 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

    In the present study, a novel multichannel loudspeaker-based virtual auditory environment (VAE) is introduced. The VAE aims at providing a versatile research environment for investigating the auditory signal processing in real environments, i.e., considering multiple sound sources and room...... of the mRIR with an acoustic signal. The derivation of the mRIRs takes into account that (i) auditory localization is most sensitive to the location of the direct sound and (ii) that auditory localization performance is rather poor for early reflections and even worse for late reverberation. 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....

  4. New insights into defibrillation of the heart from realistic simulation studies.

    Science.gov (United States)

    Trayanova, Natalia A; Rantner, Lukas J

    2014-05-01

    Cardiac defibrillation, as accomplished nowadays by automatic, implantable devices, constitutes the most important means of combating sudden cardiac death. Advancing our understanding towards a full appreciation of the mechanisms by which a shock interacts with the heart, particularly under diseased conditions, is a promising approach to achieve an optimal therapy. The aim of this article is to assess the current state-of-the-art in whole-heart defibrillation modelling, focusing on major insights that have been obtained using defibrillation models, primarily those of realistic heart geometry and disease remodelling. The article showcases the contributions that modelling and simulation have made to our understanding of the defibrillation process. The review thus provides an example of biophysically based computational modelling of the heart (i.e. cardiac defibrillation) that has advanced the understanding of cardiac electrophysiological interaction at the organ level, and has the potential to contribute to the betterment of the clinical practice of defibrillation.

  5. XCAT/DRASIM: a realistic CT/human-model simulation package

    Science.gov (United States)

    Fung, George S. K.; Stierstorfer, Karl; Segars, W. Paul; Taguchi, Katsuyuki; Flohr, Thomas G.; Tsui, Benjamin M. W.

    2011-03-01

    The aim of this research is to develop a complete CT/human-model simulation package by integrating the 4D eXtended CArdiac-Torso (XCAT) phantom, a computer generated NURBS surface based phantom that provides a realistic model of human anatomy and respiratory and cardiac motions, and the DRASIM (Siemens Healthcare) CT-data simulation program. Unlike other CT simulation tools which are based on simple mathematical primitives or voxelized phantoms, this new simulation package has the advantages of utilizing a realistic model of human anatomy and physiological motions without voxelization and with accurate modeling of the characteristics of clinical Siemens CT systems. First, we incorporated the 4D XCAT anatomy and motion models into DRASIM by implementing a new library which consists of functions to read-in the NURBS surfaces of anatomical objects and their overlapping order and material properties in the XCAT phantom. Second, we incorporated an efficient ray-tracing algorithm for line integral calculation in DRASIM by computing the intersection points of the rays cast from the x-ray source to the detector elements through the NURBS surfaces of the multiple XCAT anatomical objects along the ray paths. Third, we evaluated the integrated simulation package by performing a number of sample simulations of multiple x-ray projections from different views followed by image reconstruction. The initial simulation results were found to be promising by qualitative evaluation. In conclusion, we have developed a unique CT/human-model simulation package which has great potential as a tool in the design and optimization of CT scanners, and the development of scanning protocols and image reconstruction methods for improving CT image quality and reducing radiation dose.

  6. 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

    2014-05-01

    We report on numerical simulations of a zincblende InP surface quantum dot (QD) on \\text{I}{{\\text{n}}_{0.48}}\\text{G}{{\\text{a}}_{0.52}}\\text{P} buffer. Our model is strictly based on experimental structures, since we extrapolated a three-dimensional dot directly by atomic force microscopy results. Continuum electromechanical, \\vec{k}\\;\\cdot \\;\\vec{p} 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 \\vec{k}\\;\\cdot \\;\\vec{p} 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

  7. PENINGKATAN MOTIVASI BELAJAR SISWA MELALUI PENERAPAN PENDEKATAN REALISTIC MATHEMATICS EDUCATION (RME

    Directory of Open Access Journals (Sweden)

    Marini Marini

    2017-04-01

    Full Text Available The purpose of this study is to describe the learning process with the approach of Realistic Mathematics Education (RME, which can increase the motivation to learn mathematics student in materials Systems of Linear Equations in Two Variables on VIII-C students of SMP IT Ash-Shadhili. This research was a Classroom Action Research consisting of four stages, namely planning, action, observation and reflection. In the RME approach, teachers initiate learning by giving realistic problems. Students are asked to understand the problem and then solve it by discussing based on their knowledge and experience on teacher guidance. Students are then asked to discuss and compare answers through presentation activities during class discussions. Teachers motivate students to ask questions, give feedback or feedback. At the end of the learning the students are given the opportunity to deduce the material they have learned. The results showed that the RME approach learning can increase student motivation. This was proven by the percentage of observation results of students' learning motivation classically reached 83.33%, while the average percentage of observation results every meeting of two observers reached 80.37% in either category. Tujuan penelitian ini adalah untuk mendeskripsikan proses pembelajaran dengan pendekatan Realistic Mathematics Education (RME yang dapat meningkatkan motivasi belajar matematika siswa pada materi Sistem Persamaan Linier Dua Variabel di kelas VIII-C SMP IT Asy-Syadzili. Penelitian ini merupakan Penelitian Tindakan Kelas yang terdiri atas empat tahapan, yaitu perencanaan, tindakan, pengamatan dan refleksi. Pada pendekatan RME, guru mengawali pembelajaran dengan memberikan masalah realistik. Siswa diminta untuk memahami masalah kemudian menyelesaikannya dengan cara berdiskusi berdasarkan pengetahuan dan pengalaman mereka atas bimbingan guru. Selanjutnya siswa diminta untuk mendiskusikan dan membandingkan jawaban melalui kegiatan

  8. 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

  9. The relative greenhouse gas impacts of realistic dietary choices

    International Nuclear Information System (INIS)

    Berners-Lee, M.; Hoolohan, C.; Cammack, H.; Hewitt, C.N.

    2012-01-01

    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 CO 2 e person −1 day −1 , or 2.7 t CO 2 e person −1 y −1 . This gives total food-related GHG emissions of 167 Mt CO 2 e (1 Mt=10 6 metric tonnes; CO 2 e being the mass of CO 2 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 CO 2 e 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 CO 2 e 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 CO 2 e y −1 .

  10. The tenants in the vineyard (GThom 65/Mark 12:1-12): A realistic ...

    African Journals Online (AJOL)

    The tenants in the vineyard (GThom 65/Mark 12:1-12): A realistic and socialscientific reading. Ernest van Eck. Abstract. Kloppenborg's reading of the parable of the tenants (Mk 12:1-12/GThom 65) can be regarded as the first thoroughgoing realistic interpretation of the Tenants. By using extensive literary evidence on ...

  11. Treatments for people living with schizophrenia in Sub-Saharan Africa: an adapted realist review.

    Science.gov (United States)

    Chidarikire, S; Cross, M; Skinner, I; Cleary, M

    2018-03-01

    To identify the treatments and interventions available and their impact on people living with schizophrenia in Sub-Saharan Africa. Help-seeking behaviour and the choice of treatment are largely influenced by socio-cultural factors and beliefs about the causes of mental illness. This review addresses the gap in knowledge regarding the treatment options available to people living with schizophrenia in Sub-Saharan Africa. Adapted realist literature review. Electronic databases searched in June 2016 included PubMed, EMBASE, PsycINFO, ProQuest and CINAHL. The adapted realist review approach used to synthesize the published research involved identifying the review aim, searching and selecting relevant studies, extracting, iteratively analysing and synthesizing relevant data and reporting results. Forty studies from eight countries were reviewed. Most people were treated by both faith/traditional healers and modern psychiatry. Common treatments included antipsychotics, electroconvulsive therapy and psychosocial interventions. Few treatment options were available outside major centres, there was poor adherence to medication and families reported a high level of burden associated with caring for a relative. Major limitations of this review were the lack of studies, variable quality and low level of evidence available from most countries from Sub-Saharan Africa and lack of generalizability. People living with schizophrenia in Sub-Saharan Africa were treated by faith, traditional healers and modern psychiatry, if at all. Further research is needed to better understand the local situation and the implications for caring for people from this region. Mental health services in Sub-Saharan Africa are limited by fiscal shortages, lack of mental health services and qualified mental health professionals. This review provides evidence to inform nursing and healthcare policy, including recruiting and training mental health professionals and ensuring access to evidence-based, person

  12. How economic crises affect alcohol consumption and alcohol-related health problems: a realist systematic review.

    Science.gov (United States)

    de Goeij, Moniek C M; Suhrcke, Marc; Toffolutti, Veronica; van de Mheen, Dike; Schoenmakers, Tim M; Kunst, Anton E

    2015-04-01

    Economic crises are complex events that affect behavioral patterns (including alcohol consumption) via opposing mechanisms. With this realist systematic review, we aimed to investigate evidence from studies of previous or ongoing crises on which mechanisms (How?) play a role among which individuals (Whom?). Such evidence would help understand and predict the potential impact of economic crises on alcohol consumption. Medical, psychological, social, and economic databases were used to search for peer-reviewed qualitative or quantitative empirical evidence (published January 1, 1990-May 1, 2014) linking economic crises or stressors with alcohol consumption and alcohol-related health problems. We included 35 papers, based on defined selection criteria. From these papers, we extracted evidence on mechanism(s), determinant, outcome, country-level context, and individual context. We found 16 studies that reported evidence completely covering two behavioral mechanisms by which economic crises can influence alcohol consumption and alcohol-related health problems. The first mechanism suggests that psychological distress triggered by unemployment and income reductions can increase drinking problems. The second mechanism suggests that due to tighter budget constraints, less money is spent on alcoholic beverages. Across many countries, the psychological distress mechanism was observed mainly in men. The tighter budget constraints mechanism seems to play a role in all population subgroups across all countries. For the other three mechanisms (i.e., deterioration in the social situation, fear of losing one's job, and increased non-working time), empirical evidence was scarce or absent, or had small to moderate coverage. This was also the case for important influential contextual factors described in our initial theoretical framework. This realist systematic review suggests that among men (but not among women), the net impact of economic crises will be an increase in harmful

  13. Validation of a realistic, simple, and inexpensive EUS-FNA training model using isolated porcine stomach.

    Science.gov (United States)

    Hoshi, Koki; Irisawa, Atsushi; Shibukawa, Goro; Yamabe, Akane; Fujisawa, Mariko; Igarashi, Ryo; Yoshida, Yoshitsugu; Abe, Yoko; Imbe, Koh

    2016-09-01

    Trainees are required to learn EUS-FNA using a model before working with a patient. The aim of the current study was to validate a new training model developed for EUS-FNA. Several fresh chicken tenderloins were embedded as target lesions in the submucosal layer of an isolated porcine stomach. The stomach was fixed to a plate with nails, and was placed in a tub filled with water. The primary endpoint was feasibility of the newly developed model for EUS-FNA training, evaluated as follows: 1) visualization of the target lesion with blinding for lesion location; 2) penetrability of the needle; 3) sampling rate of macroscopic specimen; and 4) ROSE capability. Secondary endpoints were its durability and utility for multiple EUS-FNA procedures during EUS-FNA training, and the ease and cost of preparing the model. Six endoscopists (1 expert, 5 trainees) attempted EUS-FNA procedures using this model. The target lesion could be identified clearly, and EUS-FNA could be performed with realistic resistance felt. In addition, rapid on-site evaluation could be easily achieved. Based on 10 needlings by each endoscopist, adequate specimens for histology could be macroscopically taken with an average 85 % success rate. Visibility and maneuverability were maintained throughout all needlings. Preparation time for this model was less than 30 minutes with a total cost of $ 22. An easy-to-use and inexpensive training model with a realistic feel of needling was created. This model can potentially enable beginners to practice safe and effective EUS-FNA procedures.

  14. Negative findings in electronic health records and biomedical ontologies: a realist approach.

    Science.gov (United States)

    Ceusters, Werner; Elkin, Peter; Smith, Barry

    2007-12-01

    A substantial fraction of the observations made by clinicians and entered into patient records are expressed by means of negation or by using terms which contain negative qualifiers (as in "absence of pulse" or "surgical procedure not performed"). This seems at first sight to present problems for ontologies, terminologies and data repositories that adhere to a realist view and thus reject any reference to putative non-existing entities. Basic Formal Ontology (BFO) and Referent Tracking (RT) are examples of such paradigms. The purpose of the research here described was to test a proposal to capture negative findings in electronic health record systems based on BFO and RT. We analysed a series of negative findings encountered in 748 sentences taken from 41 patient charts. We classified the phenomena described in terms of the various top-level categories and relations defined in BFO, taking into account the role of negation in the corresponding descriptions. We also studied terms from SNOMED-CT containing one or other form of negation. We then explored ways to represent the described phenomena by means of the types of representational units available to realist ontologies such as BFO. We introduced a new family of 'lacks' relations into the OBO Relation Ontology. The relation lacks_part, for example, defined in terms of the positive relation part_of, holds between a particular p and a universal u when p has no instance of u as part. Since p and u both exist, assertions involving 'lacks_part' and its cognates meet the requirements of positivity. By expanding the OBO Relation Ontology, we were able to accommodate nearly all occurrences of negative findings in the sample studied.

  15. Using realist evaluation to assess primary healthcare teams' responses to intimate partner violence in Spain.

    Science.gov (United States)

    Goicolea, Isabel; Hurtig, Anna-Karin; San Sebastian, Miguel; Marchal, Bruno; Vives-Cases, Carmen

    2015-01-01

    Few evaluations have assessed the factors triggering an adequate health care response to intimate partner violence. This article aimed to: 1) describe a realist evaluation carried out in Spain to ascertain why, how and under what circumstances primary health care teams respond to intimate partner violence, and 2) discuss the strengths and challenges of its application. We carried out a series of case studies in four steps. First, we developed an initial programme theory (PT1), based on interviews with managers. Second, we refined PT1 into PT2 by testing it in a primary healthcare team that was actively responding to violence. Third, we tested the refined PT2 by incorporating three other cases located in the same region. Qualitative and quantitative data were collected and thick descriptions were produced and analysed using a retroduction approach. Fourth, we analysed a total of 15 cases, and identified combinations of contextual factors and mechanisms that triggered an adequate response to violence by using qualitative comparative analysis. There were several key mechanisms -the teams' self-efficacy, perceived preparation, women-centred care-, and contextual factors -an enabling team environment and managerial style, the presence of motivated professionals, the use of the protocol and accumulated experience in primary health care- that should be considered to develop adequate primary health-care responses to violence. The full application of this realist evaluation was demanding, but also well suited to explore a complex intervention reflecting the situation in natural settings. Copyright © 2015 SESPAS. Published by Elsevier Espana. All rights reserved.

  16. 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.

  17. 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.

  18. 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...

  19. Managing diabetes in people with dementia: a realist review.

    Science.gov (United States)

    Bunn, Frances; Goodman, Claire; Jones, Peter Reece; Russell, Bridget; Trivedi, Daksha; Sinclair, Alan; Bayer, Antony; Rait, Greta; Rycroft-Malone, Jo; Burton, Chris

    2017-12-01

    Dementia and diabetes mellitus are common long-term conditions that coexist in a large number of older people. People living with dementia and diabetes may be at increased risk of complications such as hypoglycaemic episodes because they are less able to manage their diabetes. To identify the key features or mechanisms of programmes that aim to improve the management of diabetes in people with dementia and to identify areas needing further research. Realist review, using an iterative, stakeholder-driven, four-stage approach. This involved scoping the literature and conducting stakeholder interviews to develop initial programme theories, systematic searches of the evidence to test and develop the theories, and the validation of programme theories with a purposive sample of stakeholders. Twenty-six stakeholders (user/patient representatives, dementia care providers, clinicians specialising in dementia or diabetes and researchers) took part in interviews and 24 participated in a consensus conference. The following databases were searched from 1990 to March 2016: MEDLINE (PubMed), Cumulative Index to Nursing and Allied Health Literature, Scopus, The Cochrane Library (including the Cochrane Database of Systematic Reviews), Database of Abstracts of Reviews of Effects, the Health Technology Assessment (HTA) database, NHS Economic Evaluation Database, AgeInfo (Centre for Policy on Ageing - UK), Social Care Online, the National Institute for Health Research (NIHR) portfolio database, NHS Evidence, Google (Google Inc., Mountain View, CA, USA) and Google Scholar (Google Inc., Mountain View, CA, USA). We included 89 papers. Ten papers focused directly on people living with dementia and diabetes, and the rest related to people with dementia or diabetes or other long-term conditions. We identified six context-mechanism-outcome (CMO) configurations that provide an explanatory account of how interventions might work to improve the management of diabetes in people living with

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

    Science.gov (United States)

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

    2017-01-01

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

  1. The role of students' activities in Indonesian realistic mathematics education in primary schools of Aceh

    Science.gov (United States)

    Zubainur, Cut Morina; Veloo, Arsaythamby; Khalid, Rozalina

    2015-05-01

    This study aims to explore the implementation of the Indonesian Realistic Mathematics Education (PMRI) in Aceh primary schools, Indonesia. This study investigates the students' mathematics activities involved in the implementation of PMRI and for this purpose; students' mathematics activities in the classroom were observed. Students were observed three times within five weeks during mathematics class, based on PMRI. A total of 25 year five students from a public school participated in this study. Observation check list was used in this study based on ten items. The observation conducted was based on two different time periods which were 105 minutes for group A and 70 minutes for group B. The observation was conducted every 5 minutes. The results show that PMRI is being practised in Aceh, but not completely. This study shows that mathematics activities for those who were taught using PMRI are higher than for those using the traditional approach. Overall, the findings showed that the number of student activities undertaken in PMRI achieved 90.56%. The higher percentage of activities suggests that the Aceh Education Office expands the implementation of PMRI in all primary schools so that learning of mathematics is more effective. This indirectly increases the mathematics achievement of students in Aceh to a higher level on par with Indonesia's national achievement.

  2. 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.

  3. 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…

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

    Directory of Open Access Journals (Sweden)

    Effandi Zakaria

    2017-02-01

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

  5. [A new age of mass casuality education? : The InSitu project: realistic training in virtual reality environments].

    Science.gov (United States)

    Lorenz, D; Armbruster, W; Vogelgesang, C; Hoffmann, H; Pattar, A; Schmidt, D; Volk, T; Kubulus, D

    2016-09-01

    . Interactive, identifiable, and realistic training environments based on projector systems could in future enable a repetitive exercise with changes within a decision tree, in reproducibility, and within different occupational groups. With a hard- and software environment numerous accident situations can be depicted and practiced. The main expense is the creation of the virtual accident scenes. As the appropriate city models and other three-dimensional geographical data are already available, this expenditure is very low compared with the planning costs of a large-scale exercise.

  6. 3D Realistic Radiative Hydrodynamic Modeling of a Moderate-Mass Star: Effects of Rotation

    Science.gov (United States)

    Kitiashvili, Irina; Kosovichev, Alexander G.; Mansour, Nagi N.; Wray, Alan A.

    2018-01-01

    Recent progress in stellar observations opens new perspectives in understanding stellar evolution and structure. However, complex interactions in the turbulent radiating plasma together with effects of magnetic fields and rotation make inferences of stellar properties uncertain. The standard 1D mixing-length-based evolutionary models are not able to capture many physical processes of stellar interior dynamics, but they provide an initial approximation of the stellar structure that can be used to initialize 3D time-dependent radiative hydrodynamics simulations, based on first physical principles, that take into account the effects of turbulence, radiation, and others. In this presentation we will show simulation results from a 3D realistic modeling of an F-type main-sequence star with mass 1.47 Msun, in which the computational domain includes the upper layers of the radiation zone, the entire convection zone, and the photosphere. The simulation results provide new insight into the formation and properties of the convective overshoot region, the dynamics of the near-surface, highly turbulent layer, the structure and dynamics of granulation, and the excitation of acoustic and gravity oscillations. We will discuss the thermodynamic structure, oscillations, and effects of rotation on the dynamics of the star across these layers.

  7. Hierarchical Precoding in a Realistic Ultradense Heterogeneous Environment Exceeding the Degrees of Freedom

    Directory of Open Access Journals (Sweden)

    Mohamed Shehata

    2016-01-01

    Full Text Available Cell densification is a widely used approach to increase the spectral efficiency per area of cellular networks. Such Ultradense Networks (UDNs consisting of small cells are often coordinated by macro base stations (BSs. With universal frequency reuse interference from the macro BS limits the system spectral efficiency. In this work we exploit the degrees of freedom at the macro BS to apply interference coordination. We propose a hierarchical precoding strategy in the spatial domain in order to project interference from the macro BS into the subspace of small cell users enabling linear cancellation. The macro BS interference towards small cell users is aligned within the joint null space of users served by the macro BS. Compared to classical interference alignment, our scheme does not require coordination between macrocells and small cells. We present three algorithms: in the first the interference is minimized by iterative alignment, in the second the uncoordinated interference from the small cells is considered, and in the third iterative Minimum Mean Square Error (MMSE technique is used. We provide numerical evaluation, complexity analysis, and robustness analysis of these algorithms based on a realistic channel model showing the benefit of hierarchical precoding compared to the uncoordinated case.

  8. 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.

  9. An Automatic Navigation System for Unmanned Surface Vehicles in Realistic Sea Environments

    Directory of Open Access Journals (Sweden)

    Xiaojie Sun

    2018-01-01

    Full Text Available In recent years, unmanned surface vehicles (USVs have received notable attention because of their many advantages in civilian and military applications. To improve the autonomy of USVs, this paper describes a complete automatic navigation system (ANS with a path planning subsystem (PPS and collision avoidance subsystem (CAS. The PPS based on the dynamic domain tunable fast marching square (DTFMS method is able to build an environment model from a real electronic chart, where both static and dynamic obstacles are well represented. By adjusting the S a t u r a t i o n , the generated path can be changed according to the requirements for security and path length. Then it is used as a guidance trajectory for the CAS through a dynamic target point. In the CAS, according to finite control set model predictive control (FCS-MPC theory, a collision avoidance control algorithm is developed to track trajectory and avoid collision based on a three-degree of freedom (DOF planar motion model of USV. Its target point and security evaluation come from the planned path and environmental model of the PPS. Moreover, the prediction trajectory of the CAS can guide changes in the dynamic domain model of the vessel itself. Finally, the system has been tested and validated using the situations of three types of encounters in a realistic sea environment.

  10. A Realistically Perturbed Atmosphere and Ocean De-Aliasing Model for Future Gravity Mission Simulation Studies

    Science.gov (United States)

    Dobslaw, Henryk; Forootan, Ehsan; Bergmann-Wolf, Inga; Neumayer, Karl-Hans; Mayer-Gürr, Torsten; Kusche, Jürgen; Flechtner, Frank

    2015-04-01

    Recently completed performance studies of future gravity mission concepts arrived at sometimes contradicting conclusions about the importance of non-tidal aliasing errors that remain in the finally retrieved gravity field time-series. In those studies, typically a fraction of the differences between two different models of atmosphere and ocean mass variability determined the magnitude of the aliasing errors. Since differences among arbitrary pairs of the numerical models available might lead to widely different aliasing errors and thus conclusions regarding limiting error contributors of a candidate mission, we present here for the first time a version of a realistically perturbed de-aliasing model that is consistent with the updated ESA Earth System Model for gravity mission simulation studies (Dobslaw et al., 2015). The error model is available over the whole 12-year period of the ESA ESM and consists of two parts: (i) a component containing signals from physical processes that are intentionally omitted from de-aliasing models, as for a example, variations in global eustatic sea-level; and (ii) a series of true errors that consist of in total five different components with realistically re-scaled variability at both small and large spatial scales for different frequency bands ranging from sub-daily to sub-monthly periods. Based on a multi-model ensemble of atmosphere and ocean mass variability available to us for the year 2006, we will demonstrate that our re-scaled true errors have plausible magnitudes and correlation characteristics in all frequency bands considered. The realism of the selected scaling coefficients for periods between 1 and 30 days is tested further by means of a variance component estimation based on the constrained daily GRACE solution series ITSG-GRACE2014. Initial full-scale simulation experiments are used to re-assess the relative importance of non-tidal de-aliasing errors for the GRACE-FO mission, which might be subsequently expanded to

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

    Science.gov (United States)

    Munson, Charles E.; Arif, Muhammad; Streque, Jeremy; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim; El Gmili, Youssef; Salvestrini, Jean-Paul; Voss, Paul L.; Ougazzaden, Abdallah

    2015-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-14

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

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

    International Nuclear Information System (INIS)

    Munson, Charles E.; Voss, Paul L.; Ougazzaden, Abdallah; Arif, Muhammad; Salvestrini, Jean-Paul; Streque, Jeremy; El Gmili, Youssef; Belahsene, Sofiane; Martinez, Anthony; Ramdane, Abderrahim

    2015-01-01

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

  14. Approach to sensor node calibration for efficient localisation in wireless sensor networks in realistic scenarios

    CSIR Research Space (South Africa)

    Mwila, MK

    2014-06-01

    Full Text Available Conference on Ambient Systems, Networks and Technologies (ANT-2014) Approach to Sensor Node Calibration for Efficient Localisation in Wireless Sensor Networks in Realistic Scenarios Martin K. Mwilaa, Karim Djouanib, Anish Kurienc,∗ a...

  15. Development of Realistic Head Models for Electromagnetic Source Imaging of the Human Brain

    National Research Council Canada - National Science Library

    Akalin, Z

    2001-01-01

    In this work, a methodology is developed to solve the forward problem of electromagnetic source imaging using realistic head models, For this purpose, first segmentation of the 3 dimensional MR head...

  16. Reinventing Sex: The Construction of Realistic Definitions of Sex and Gender.

    Science.gov (United States)

    Small, Chanley M.

    1998-01-01

    Presents a set of criteria for constructing a fair and realistic understanding of sex. Recognizes the impact that science can have on social policies and values and recommends that the definitions of sex and gender be carefully crafted. (DDR)

  17. Book Review: A Liberal Actor in a Realist World the European Union ...

    African Journals Online (AJOL)

    Abstract. Book Title: A Liberal Actor in a Realist World the European Union Regulatory State and the Global Political Economy of Energy. Book Author: Andreas Goldthau & Nick Sitter. Oxford University Press Oxford 2015. ISBN 9780198719595 ...

  18. The effects of presenting multidigit mathematics problems in a realistic context on sixth graders' problem solving

    NARCIS (Netherlands)

    Hickendorff, M.

    2013-01-01

    Mathematics education and assessments increasingly involve arithmetic problems presented in context: a realistic situation that requires mathematical modeling. This study assessed the effects of such typical school mathematics contexts on two aspects of problem solving: performance and strategy use.

  19. 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....

  20. Realistic Avatar Eye and Head Animation Using a Neurobiological Model of Visual Attention

    National Research Council Canada - National Science Library

    Itti, L; Dhavale, N; Pighin, F

    2003-01-01

    We describe a neurobiological model of visual attention and eye/head movements in primates, and its application to the automatic animation of a realistic virtual human head watching an unconstrained...

  1. Development of Realistic Head Models for Electromagnetic Source Imaging of the Human Brain

    National Research Council Canada - National Science Library

    Akalin, Z

    2001-01-01

    ... images is performed Then triangular, quadratic meshes are formed for the interfaces of the tissues, Thus, realistic meshes, representing scalp, skull, CSF, brain and eye tissues, are formed, At least...

  2. Sources of nonlinear behavior and Predictability in a realistic atmospheric model: a data modeling statistical approach

    Science.gov (United States)

    Peters, J. M.; Kravtsov, S.

    2011-12-01

    This study quantifies the dependence of nonlinear regimes (manifested in non-gaussian probability distributions) and spreads of ensemble trajectories in a reduced phase space of a realistic three-layer quasi-geostrophic (QG3) atmospheric model on this model's climate state.To elucidate probabilistic properties of the QG3 trajectories, we compute, in phase planes of leading EOFs of the model, the coefficients of the corresponding Fokker-Planck (FP) equations. These coefficients represent drift vectors (computed from one-day phase space tendencies) and diffusion tensors (computed from one-day lagged covariance matrices of model trajectory displacements), and are based on a long QG3 simulation. We also fit two statistical trajectory models to the reduced phase-space time series spanned by the full QG3 model states. One reduced model is a standard Linear Inverse Model (LIM) fitted to a long QG3 time series. The LIM model is forced by state-independent (additive) noise and has a deterministic operator which represents non-divergent velocity field in the reduced phase space considered. The other, more advanced model (NSM), is nonlinear, divergent, and is driven by state-dependent noise. The NSM model mimics well the full QG3 model trajectory behavior in the reduced phase space; its corresponding FP model is nearly identical to that based on the full QG3 simulations. By systematic analysis of the differences between the drift vectors and diffusion tensors of the QG3-based, NSM-based, and LIM-based FP models, as well as the PDF evolution simulated by these FP models, we disentangle the contributions of the multiplicative noise and deterministic dynamics into nonlinear behavior and predictability of the atmospheric states produced by the dynamical QG3 model.

  3. Making the Abolition of War a Realistic Goal.

    Science.gov (United States)

    Sharp, Gene

    As a means of counteracting current widespread acceptance of war and war preparations with a sense of resignation and hopelessness/powerlessness, this monograph proposes a nonviolent strategy by which citizens can discourage or thwart either internal usurpation or external invasion/occupation. Designated Civilian Based Defense (CBD), this system…

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

    NARCIS (Netherlands)

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

    2012-01-01

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

  5. The need for and development of behaviourally realistic agents

    NARCIS (Netherlands)

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

    2003-01-01

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

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

    OpenAIRE

    Effandi Zakaria; Muzakkir Syamaun

    2017-01-01

    This study was conducted to determine the effect of Realistic Mathematics Education Approach on mathematics achievement and student attitudes towards mathematics. This study also sought determine the relationship between student achievement and attitudes towards mathematics. This study used a quasi-experimental design conducted on 61 high school students at SMA Unggul Sigli. Students were divided into two groups, the treatment group $(n = 30)$ namely, the Realistic Mathematics Approach group ...

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

    OpenAIRE

    Zulkardi, Z.; Nieveen, N.M.

    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.

  8. DMTO: a realistic ontology for standard diabetes mellitus treatment.

    Science.gov (United States)

    El-Sappagh, Shaker; Kwak, Daehan; Ali, Farman; Kwak, Kyung-Sup

    2018-02-06

    Treatment of type 2 diabetes mellitus (T2DM) is a complex problem. A clinical decision support system (CDSS) based on massive and distributed electronic health record data can facilitate the automation of this process and enhance its accuracy. The most important component of any CDSS is its knowledge base. This knowledge base can be formulated using ontologies. The formal description logic of ontology supports the inference of hidden knowledge. Building a complete, coherent, consistent, interoperable, and sharable ontology is a challenge. This paper introduces the first version of the newly constructed Diabetes Mellitus Treatment Ontology (DMTO) as a basis for shared-semantics, domain-specific, standard, machine-readable, and interoperable knowledge relevant to T2DM treatment. It is a comprehensive ontology and provides the highest coverage and the most complete picture of coded knowledge about T2DM patients' current conditions, previous profiles, and T2DM-related aspects, including complications, symptoms, lab tests, interactions, treatment plan (TP) frameworks, and glucose-related diseases and medications. It adheres to the design principles recommended by the Open Biomedical Ontologies Foundry and is based on ontological realism that follows the principles of the Basic Formal Ontology and the Ontology for General Medical Science. DMTO is implemented under Protégé 5.0 in Web Ontology Language (OWL) 2 format and is publicly available through the National Center for Biomedical Ontology's BioPortal at http://bioportal.bioontology.org/ontologies/DMTO . The current version of DMTO includes more than 10,700 classes, 277 relations, 39,425 annotations, 214 semantic rules, and 62,974 axioms. We provide proof of concept for this approach to modeling TPs. The ontology is able to collect and analyze most features of T2DM as well as customize chronic TPs with the most appropriate drugs, foods, and physical exercises. DMTO is ready to be used as a knowledge base for

  9. 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.

  10. 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......, 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....

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

    Science.gov (United States)

    2011-10-01

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

  12. Reproduction of Realistic Background Noise for Testing Telecommunications Devices

    DEFF Research Database (Denmark)

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

    2015-01-01

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

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

    International Nuclear Information System (INIS)

    Court, Laurence E.; Seco, Joao; Lu Xingqi; Ebe, Kazuyu; Mayo, Charles; Ionascu, Dan; Winey, Brian; Giakoumakis, Nikos; Aristophanous, Michalis; Berbeco, Ross; Rottman, Joerg; Bogdanov, Madeleine; Schofield, Deborah; Lingos, Tania

    2010-01-01

    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

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

    Science.gov (United States)

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

    2008-04-01

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

  15. Implications of introducing realistic fire response traits in a Dynamic Global Vegetation Model

    Science.gov (United States)

    Kelley, D.; Harrison, S. P.; Prentice, I. C.

    2013-12-01

    the next growing season, while regenerating from seed at 10% the rate of non-resprouters. Tests of LPX-Mv1 for Australia - a continent with a wide range of fire-adapted ecosystems - show that it produces a 33% improvement in the simulation of vegetation composition compared to the previous version of the model, with more realistic vegetation transitions from forests to woodland/savanna. It also produces a 19% improvement in the simulation of burnt area compared to the original model. Resprouting PFTs dominate tropical and temperate areas where the climate is semi-humid but are not common in very dry or very wet areas. Comparison with site-based observations of the abundance of resprouters indicate this is realistic. Ecosystems dominated by resprouters in the simulations recover to pre-fire levels of biomass within 5-7 years, much faster than ecosystems dominated by non-resprouters; again this is confirmed by our analyses of the observations. Simulations of the response to projected future climate change show that the incorporation of adaptive bark thickness and of resprouting has a significant effect on terrestrial carbon stocks in fire-affected areas.

  16. 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.

  17. Simulation of realistic background noise using multiple loudspeakers

    DEFF Research Database (Denmark)

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

    2015-01-01

    optimizes the reproduced sound at a sweet spot in the center of the array with radius determined by a spherical microphone array, which is used to derive the spherical harmonics decomposition of the reference sound. The four-loudspeaker-based method equalizes the magnitude response at the ears of a head...... positions were defined, i.e. the ears of the HATS, positions close to a device under test, and standardized positions as described in ETSI TS 103 224. A listening experiment was performed to evaluate the perceived quality of the reproduced sounds at the microphones close to a device under test...

  18. Recent Progress on the Simulation of Realistic Images for Starshade Missions

    Science.gov (United States)

    Hu, Mengya; Harness, Anthony; Kasdin, Jeremy; Vanderbei, Robert

    2018-01-01

    Imaging systems with Starshades aim to achieve high contrast (~10^(-10)), which enables direct imaging for exoplanet detection and spectroscopic characterization. The contrast, however, is inevitably degraded by various errors, such as the misalignment of the starshade and detector noise, leading to a lower signal-to-noise ratio. Post-processing can improve signal-to-noise and lead to the detection of fainter targets. However, post-processing methods which are specialized for starshade images have yet to be developed and methods used for coronagraph images have not been applied to starshade images. We present the latest result towards adapting and developing image processing methods for starshade images. We generate realistic starshade images based on simulations of real astronomical scenes and include the effects of starshade defects, wavefront error, detector noise and the system dynamics of formation flying between the starshade and the telescope. Post-processing algorithms such as the Karhunen-Loeve Image Projection (KLIP) are then applied to the simulated images and we investigate the improvement in signal-to-noise.

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

    Directory of Open Access Journals (Sweden)

    Leonardo Trigueiro dos Santos

    2016-12-01

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

  20. Assessment of vectorial total variation penalties on realistic dual-energy CT data.

    Science.gov (United States)

    Rigie, David S; Sanchez, Adrian A; La Rivière, Patrick J

    2017-04-21

    Vectorial extensions of total variation have recently been developed for regularizing the reconstruction and denoising of multi-channel images, such as those arising in spectral computed tomography. Early studies have focused mainly on simulated, piecewise-constant images whose structure may favor total-variation penalties. In the current manuscript, we apply vectorial total variation to real dual-energy CT data of a whole turkey in order to determine if the same benefits can be observed in more complex images with anatomically realistic textures. We consider the total nuclear variation ([Formula: see text]) as well as another vectorial total variation based on the Frobenius norm ([Formula: see text]) and standard channel-by-channel total variation ([Formula: see text]). We performed a series of 3D TV denoising experiments comparing the three TV variants across a wide range of smoothness parameter settings, optimizing each regularizer according to a very-high-dose 'ground truth' image. Consistent with the simulation studies, we find that both vectorial TV variants achieve a lower error than the channel-by-channel TV and are better able to suppress noise while preserving actual image features. In this real data study, the advantages are subtler than in the previous simulation study, although the [Formula: see text] penalty is found to have clear advantages over either [Formula: see text] or [Formula: see text] when comparing material images formed from linear combinations of the denoised energy images.

  1. Group Augmentation in Realistic Visual-Search Decisions via a Hybrid Brain-Computer Interface.

    Science.gov (United States)

    Valeriani, Davide; Cinel, Caterina; Poli, Riccardo

    2017-08-10

    Groups have increased sensing and cognition capabilities that typically allow them to make better decisions. However, factors such as communication biases and time constraints can lead to less-than-optimal group decisions. In this study, we use a hybrid Brain-Computer Interface (hBCI) to improve the performance of groups undertaking a realistic visual-search task. Our hBCI extracts neural information from EEG signals and combines it with response times to build an estimate of the decision confidence. This is used to weigh individual responses, resulting in improved group decisions. We compare the performance of hBCI-assisted groups with the performance of non-BCI groups using standard majority voting, and non-BCI groups using weighted voting based on reported decision confidence. We also investigate the impact on group performance of a computer-mediated form of communication between members. Results across three experiments suggest that the hBCI provides significant advantages over non-BCI decision methods in all cases. We also found that our form of communication increases individual error rates by almost 50% compared to non-communicating observers, which also results in worse group performance. Communication also makes reported confidence uncorrelated with the decision correctness, thereby nullifying its value in weighing votes. In summary, best decisions are achieved by hBCI-assisted, non-communicating groups.

  2. 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.

  3. Early warning systems and rapid response to the deteriorating patient in hospital: A systematic realist review.

    Science.gov (United States)

    McGaughey, Jennifer; O'Halloran, Peter; Porter, Sam; Blackwood, Bronagh

    2017-12-01

    To determine the Rapid Response System programme theory and investigate how the mechanisms of implementation and the characteristics of context combine to enable or constrain the implementation of Rapid Response Systems and the achievement of desired outcomes. Rapid Response Systems have been implemented internationally to improve the recognition and management of patient deterioration, reduce the need for cardiopulmonary resuscitation and improve patient outcomes. Realist review. We searched DARE, CENTRAL, NHSEED, MEDLINE, Medline In Process, EMBASE, CINAHL, PubMed, Scopus, The Web of Science and PychInfo databases from 1997 - 2017 in addition to purposively searching the grey literature looking for articles supporting, refuting or explaining Rapid Response System programme theories. Included studies were critically appraised and graded using the Critical Appraisal Skills Programme tool. Data extraction and synthesis investigated the Rapid Response System theoretical propositions against the empirical evidence to refine Rapid Response System programme theories. The review found that the Rapid Response System programme theory achieved desired outcomes when there were sufficient skills mix of experienced staff, EWS protocols were used flexibly alongside clinical judgement and staff had access to ongoing, multiprofessional, competency-based education. However, ward cultures, hierarchical referral systems, workload and staffing resources had a negative impact on the implementation of the Rapid Response System. To improve the recognition and management of patient deterioration, policymakers need to address those cultural, educational and organizational factors that have an impact on the successful implementation of Rapid Response Systems in practice. © 2017 John Wiley & Sons Ltd.

  4. Towards a More Realistic Depiction of the Earth's Surface on Maps

    Science.gov (United States)

    Drachal, Jacek; Dębowska, Anna

    2014-06-01

    In 2000, the shuttle radar topography mission (SRTM) produced the most complete, highest resolution digital elevation model (DEM) of the Earth. These data were used to create global 3″ DEM and to correct 30″ DEM which are both available on the internet. After a careful survey in the Institute of Geodesy and Cartography, Poland, these elevation data were recognized as extremely valuable and worth developing a unique form of visualization. As a result, a new design of a physical map of Europe at scale of 1:10 million was developed. For depicting the shape of the terrain, an original modification of combined shaded relief was employed, to reveal all the nuances of elevation data. True colors of the Earth's surface represented on the map originated from MODIS satellite image. The combination of true colors and terrain features made a realistic map, showing the landscapes as if from a point above the Earth. The image of the terrain is extremely detailed as it is based on the abundance of data defining the elevation of each point of land.

  5. Educational Borrowing and Mathematics Curriculum: Realistic Mathematics Education in the Dutch and Indonesian Primary Curriculum

    Directory of Open Access Journals (Sweden)

    Shintia Revina

    2018-02-01

    Full Text Available Since the late 1990s, Indonesian mathematics educators have considered Realistic Mathematics Education (RME, the Dutch approach to mathematics instruction, to be the basis for educational reform. In the National curriculum development, RME has, therefore, been reviewed as among the theoretical references to the curriculum goals and content. In the present study, an analysis of the consistency between RME and the curriculum descriptors and contents in Indonesia is presented. This is supplemented with some comparisons to that in the Netherlands. Findings in this study revealed that while most of RME principles are reflected in the Indonesian curriculum, the descriptions were often very general and less explicit compared to the Dutch curriculum. They were also limited by the content-based approach as well as by the centralized decision making process of the contents to be taught which have been pre-determined at the national level. This study suggests future research to see how the curriculum may influence teachers’ enactment of RME at classroom level.

  6. 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. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Smart-DS: Synthetic Models for Advanced, Realistic Testing: Distribution Systems and Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Venkat K [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Palmintier, Bryan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hale, Elaine T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Elgindy, Tarek [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bugbee, Bruce [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rossol, Michael N [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Lopez, Anthony J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnamurthy, Dheepak [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vergara, Claudio [MIT; Domingo, Carlos Mateo [IIT Comillas; Postigo, Fernando [IIT Comillas; de Cuadra, Fernando [IIT Comillas; Gomez, Tomas [IIT Comillas; Duenas, Pablo [MIT; Luke, Max [MIT; Li, Vivian [MIT; Vinoth, Mohan [GE Grid Solutions; Kadankodu, Sree [GE Grid Solutions

    2017-08-09

    The National Renewable Energy Laboratory (NREL) in collaboration with Massachusetts Institute of Technology (MIT), Universidad Pontificia Comillas (Comillas-IIT, Spain) and GE Grid Solutions, is working on an ARPA-E GRID DATA project, titled Smart-DS, to create: 1) High-quality, realistic, synthetic distribution network models, and 2) Advanced tools for automated scenario generation based on high-resolution weather data and generation growth projections. Through these advancements, the Smart-DS project is envisioned to accelerate the development, testing, and adoption of advanced algorithms, approaches, and technologies for sustainable and resilient electric power systems, especially in the realm of U.S. distribution systems. This talk will present the goals and overall approach of the Smart-DS project, including the process of creating the synthetic distribution datasets using reference network model (RNM) and the comprehensive validation process to ensure network realism, feasibility, and applicability to advanced use cases. The talk will provide demonstrations of early versions of synthetic models, along with the lessons learnt from expert engagements to enhance future iterations. Finally, the scenario generation framework, its development plans, and co-ordination with GRID DATA repository teams to house these datasets for public access will also be discussed.

  8. Realistic operator response measurements: Inputs to the LaSalle PRA

    International Nuclear Information System (INIS)

    Crane, G.R.; Hannaman, G.W.

    1986-01-01

    The LaSalle comprehensive probabilistic risk assessment (PRA) includes external events and internal events with explicit treatment of human actions during operations, maintenance, and surveillance. It includes common-cause considerations and dependencies covering all support functions. These human sections are included in the same fault trees applicable to both external and internal events. Realism is incorporated into the PRA via measurable values of plant parameters in contrast to license-base values, via real-time behavior of primary containment which provides more realistic operator response intervals, and via actual measurements of operator responses during engineering simulator exercise of plant-specific transient and accident events. Preliminary correlations of operator responses via the HCR measurements method indicate that measured operator unreliabilities are consistently ten to one hundred times lower than best-estimate values used in earlier PRA's. Some operator responses may indicate an unreliability measure of one thousand less than reported estimates of non-performance (omission failures). Measurements of operator response during plant recovery scenarios are currently being correlated for subsequent inclusion via SHARP methods into the LaSalle PRA. These degraded core event scenarios were defined from the PRA dominant transient and accident cut-sets leading to degraded cores with potential fission product release

  9. 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.

  10. 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. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    International Nuclear Information System (INIS)

    Courageot, E.; Kutschera, R.; Gaillard-Lecanu, E.; Jahan, S.; Riedel, A.; Therache, B.

    2013-01-01

    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)

  12. Effects of applying realistic channel conditions on performance prediction of UCA-VBLAST-MIMO systems

    Directory of Open Access Journals (Sweden)

    Mohab A. Mangoud

    2014-01-01

    Full Text Available Recently, many realistic spatially and temporally clustered channel models were developed to be applied in the simulations of multiple input multiple output (MIMO systems. IEEE 802.11n standard channel model includes spatio-temporal fading correlation effects and accounts for six various real propagation profiles. These profiles represent variety of propagation scenarios for indoor environments. This paper presents the impact of applying various channel model conditions on the link performance of Vertical Bell Laboratories Space-Time detection (VBLAST-MIMO systems that employ Uniform Circular array (UCA. Also, capacity and channel estimation accuracy for this system are investigated under different channel conditions. The effect of varying the SNR on the Channel State Information (CSI error and capacity for UCA-MIMO systems are included. Training based techniques such as Least Square (LS, scaled least square (SLS and minimum mean square error (MMSE methods and relaxed MMSE (RMMSE are considered for estimating channel properties. It is found that the presence of spatial correlation can help to improve the Channel estimation accuracy at low SNR for UCA-VBLAST-MIMO system under different spatial correlation conditions.

  13. Evaluation of digital image correlation techniques using realistic ground truth speckle images

    International Nuclear Information System (INIS)

    Cofaru, C; Philips, W; Van Paepegem, W

    2010-01-01

    Digital image correlation (DIC) has been acknowledged and widely used in recent years in the field of experimental mechanics as a contactless method for determining full field displacements and strains. Even though several sub-pixel motion estimation algorithms have been proposed in the literature, little is known about their accuracy and limitations in reproducing complex underlying motion fields occurring in real mechanical tests. This paper presents a new method for evaluating sub-pixel motion estimation algorithms using ground truth speckle images that are realistically warped using artificial motion fields that were obtained following two distinct approaches: in the first, the horizontal and vertical displacement fields are created according to theoretical formulas for the given type of experiment while the second approach constructs the displacements through radial basis function interpolation starting from real DIC results. The method is applied in the evaluation of five DIC algorithms with results indicating that the gradient-based DIC methods generally have a quality advantage when using small sized blocks and are a better choice for calculating very small displacements and strains. The Newton–Raphson is the overall best performing method with a notable quality advantage when large block sizes are employed and in experiments where large strain fields are of interest

  14. Calculation of electrical potentials on the surface of a realistic head model by finite differences

    International Nuclear Information System (INIS)

    Lemieux, L.; McBride, A.; Hand, J.W.

    1996-01-01

    We present a method for the calculation of electrical potentials at the surface of realistic head models from a point dipole generator based on a 3D finite-difference algorithm. The model was validated by comparing calculated values with those obtained algebraically for a three-shell spherical model. For a 1.25 mm cubic grid size, the mean error was 4.9% for a superficial dipole (3.75 mm from the inner surface of the skull) pointing in the radial direction. The effect of generator discretization and node spacing on the accuracy of the model was studied. Three values of the node spacing were considered: 1, 1.25 and 1.5 mm. The mean relative errors were 4.2, 6.3 and 9.3%, respectively. The quality of the approximation of a point dipole by an array of nodes in a spherical neighbourhood did not depend significantly on the number of nodes used. The application of the method to a conduction model derived from MRI data is demonstrated. (author)

  15. Jumping the gun: Faster response latencies to deceptive questions in a realistic scenario.

    Science.gov (United States)

    Mapala, Tessa; Warmelink, Lara; Linkenauger, Sally A

    2017-08-01

    Most theories of lie detection assume that lying increases cognitive load, resulting in longer response latencies during questioning. However, the studies supporting this theory are typically laboratory-based, in settings with no specific validity in security contexts. Consequently, using virtual reality (VR), we investigated how response latencies were influenced in an ecologically valid environment of interest to security professionals. In a highly realistic airport security terminal presented in VR, a security officer asked participants yes/no questions about their belongings. We found that liars actually responded more quickly to questions on which they were lying than to questions on which they were telling the truth. A control group, who answered the same questions but were not lying, answered equally quickly for all questions. We argue that this decrease in response time is possibly an unconscious reaction to questions on which individuals must answer deceptively. These results call into question the generalizability of previous research and highlight the importance of ecological validity when researching lie detection. These findings also uncover a new potential tool for enhancing lie detection in real-world scenarios.

  16. Nuclear equation of state for core-collapse supernova simulations with realistic nuclear forces

    Energy Technology Data Exchange (ETDEWEB)

    Togashi, H., E-mail: hajime.togashi@riken.jp [Nishina Center for Accelerator-Based Science, Institute of Physical and Chemical Research (RIKEN), 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Nakazato, K. [Faculty of Arts and Science, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395 (Japan); Takehara, Y.; Yamamuro, S.; Suzuki, H. [Department of Physics, Faculty of Science and Technology, Tokyo University of Science, Yamazaki 2641, Noda, Chiba 278-8510 (Japan); Takano, M. [Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Department of Pure and Applied Physics, Graduate School of Advanced Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan)

    2017-05-15

    A new table of the nuclear equation of state (EOS) based on realistic nuclear potentials is constructed for core-collapse supernova numerical simulations. Adopting the EOS of uniform nuclear matter constructed by two of the present authors with the cluster variational method starting from the Argonne v18 and Urbana IX nuclear potentials, the Thomas–Fermi calculation is performed to obtain the minimized free energy of a Wigner–Seitz cell in non-uniform nuclear matter. As a preparation for the Thomas–Fermi calculation, the EOS of uniform nuclear matter is modified so as to remove the effects of deuteron cluster formation in uniform matter at low densities. Mixing of alpha particles is also taken into account following the procedure used by Shen et al. (1998, 2011). The critical densities with respect to the phase transition from non-uniform to uniform phase with the present EOS are slightly higher than those with the Shen EOS at small proton fractions. The critical temperature with respect to the liquid–gas phase transition decreases with the proton fraction in a more gradual manner than in the Shen EOS. Furthermore, the mass and proton numbers of nuclides appearing in non-uniform nuclear matter with small proton fractions are larger than those of the Shen EOS. These results are consequences of the fact that the density derivative coefficient of the symmetry energy of our EOS is smaller than that of the Shen EOS.

  17. Realistic interpretation of quantum mechanics and encounter-delayed-choice experiment

    Science.gov (United States)

    Long, GuiLu; Qin, Wei; Yang, Zhe; Li, Jun-Lin

    2018-03-01

    In this paper, a realistic interpretation (REIN) of the wave function in quantum mechanics is briefly presented. We demonstrate that in the REIN, the wave function of a microscopic object is its real existence rather than a mere mathematical description. Specifically, the quantum object can exist in disjointed regions of space just as the wave function is distributed, travels at a finite speed, and collapses instantly upon a measurement. Furthermore, we analyze the single-photon interference in a Mach-Zehnder interferometer (MZI) using the REIN. Based on this, we propose and experimentally implement a generalized delayed-choice experiment, called the encounter-delayed-choice experiment, where the second beam splitter is decided whether or not to insert at the encounter of two sub-waves along the arms of the MZI. In such an experiment, the parts of the sub-waves, which do not travel through the beam splitter, show a particle nature, whereas the remaining parts interfere and thus show a wave nature. The predicted phenomenon is clearly demonstrated in the experiment, thus supporting the REIN idea.

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

    Science.gov (United States)

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

    2009-09-01

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

  19. RAId_DbS: Peptide Identification using Database Searches with Realistic Statistics

    Directory of Open Access Journals (Sweden)

    Ogurtsov Aleksey Y

    2007-10-01

    Full Text Available Abstract Background The key to mass-spectrometry-based proteomics is peptide identification. A major challenge in peptide identification is to obtain realistic E-values when assigning statistical significance to candidate peptides. Results Using a simple scoring scheme, we propose a database search method with theoretically characterized statistics. Taking into account possible skewness in the random variable distribution and the effect of finite sampling, we provide a theoretical derivation for the tail of the score distribution. For every experimental spectrum examined, we collect the scores of peptides in the database, and find good agreement between the collected score statistics and our theoretical distribution. Using Student's t-tests, we quantify the degree of agreement between the theoretical distribution and the score statistics collected. The T-tests may be used to measure the reliability of reported statistics. When combined with reported P-value for a peptide hit using a score distribution model, this new measure prevents exaggerated statistics. Another feature of RAId_DbS is its capability of detecting multiple co-eluted peptides. The peptide identification performance and statistical accuracy of RAId_DbS are assessed and compared with several other search tools. The executables and data related to RAId_DbS are freely available upon request.

  20. 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.

  1. Factors contributing to the effectiveness of physical activity counselling in primary care: a realist systematic review.

    Science.gov (United States)

    Gagliardi, Anna R; Abdallah, Flavia; Faulkner, Guy; Ciliska, Donna; Hicks, Audrey

    2015-04-01

    Physical activity (PA) counselling in primary care increases PA but is not consistently practiced. This study examined factors that optimise the delivery and impact of PA counselling. A realist systematic review based on the PRECEDE-PROCEED model and RAMESES principles was conducted to identify essential components of PA counselling. MEDLINE, EMBASE, Cochrane Library, PsycINFO, and Physical Education Index were searched from 2000 to 2013 for studies that evaluated family practice PA counselling. Of 1546 articles identified, 10 were eligible for review (3 systematic reviews, 5 randomised controlled trials, 2 observational studies). Counselling provided by clinicians or counsellors alone that explored motivation increased self-reported PA at least 12 months following intervention. Multiple sessions may sustain increased PA beyond 12 months. Given the paucity of eligible studies and limited detail reported about interventions, further research is needed to establish the optimal design and delivery of PA counselling. Research and planning should consider predisposing, reinforcing and enabling design features identified in these studies. Since research shows that PA counselling promotes PA but is not widely practiced, primary care providers will require training and tools to operationalize PA counselling. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. 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%.

  3. Basic requirements for realistic and unprejudiced evaluation of musical instruments

    Science.gov (United States)

    Wogram, Klaus

    2003-10-01

    In the past, the laboratory of musical acoustics of the PTB had to develop methods of subjective and objective evaluations of all kinds of musical instruments for a competition which was launched by the German ministry of economics. For this work the following questions had to be answered: (1) What makes a musical instrument play well from physical and subjective viewpoints? (2) How does the musician play the instrument, and what does he think when playing? (3) What is the influence of room acoustical parameters on sound quality? (4) How strong is the influence of prejudices concerning the brand, color, and type? (5) How can we measure the main acoustical parameters objectively? (6) What is the correlation between objective and subjective results? This presentation will give answers to these questions based on 10 years of experience with such evaluations by the author.

  4. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    Science.gov (United States)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  5. 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.

  6. Towards more realistic assessment of reactor accident consequences

    International Nuclear Information System (INIS)

    Tveten, U.

    1985-07-01

    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

  7. Stereoscopic augmented reality with pseudo-realistic global illumination effects

    Science.gov (United States)

    de Sorbier, Francois; Saito, Hideo

    2014-03-01

    Recently, augmented reality has become very popular and has appeared in our daily life with gaming, guiding systems or mobile phone applications. However, inserting object in such a way their appearance seems natural is still an issue, especially in an unknown environment. This paper presents a framework that demonstrates the capabilities of Kinect for convincing augmented reality in an unknown environment. Rather than pre-computing a reconstruction of the scene like proposed by most of the previous method, we propose a dynamic capture of the scene that allows adapting to live changes of the environment. Our approach, based on the update of an environment map, can also detect the position of the light sources. Combining information from the environment map, the light sources and the camera tracking, we can display virtual objects using stereoscopic devices with global illumination effects such as diffuse and mirror reflections, refractions and shadows in real time.

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

    Science.gov (United States)

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

    2016-01-01

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

  9. Realistic Measurement of Student Attendance in LMS Using Biometrics

    Directory of Open Access Journals (Sweden)

    Elisardo Gonzalez-Agulla

    2010-10-01

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

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

    International Nuclear Information System (INIS)

    Johnsen, S.; Furuholt, E.

    1995-01-01

    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

  11. 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.

  12. Quarkonium at finite temperature: towards realistic phenomenology from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Burnier, Yannis [Institute of Theoretical Physics, EPFL,CH-1015 Lausanne (Switzerland); Kaczmarek, Olaf [Fakultät für Physik, Universität Bielefeld,D-33615 Bielefeld (Germany); Rothkopf, Alexander [Institute for Theoretical Physics, Heidelberg University,Philosophenweg 16, 69120 Heidelberg (Germany)

    2015-12-16

    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 Re[V] with a single temperature dependent parameter m{sub D}, the Debye screening mass, and confirm the up to now tentative values of Im[V]. The obtained analytic expression for the complex potential allows us to compute quarkonium spectral functions by solving an appropriate Schrödinger 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. Quarkonium is gradually weakened by both screening (Re[V]) and scattering (Im[V]) effects that in combination lead to a shift of their in-medium spectral features to smaller frequencies, contrary to the mass gain of elementary particles at finite temperature.

  13. Passive ranging effectiveness and related metrics in realistic flight scenarios

    Science.gov (United States)

    Castaldo, Francesco; Conte, Roberto; Fortunato, Luca

    2017-10-01

    Passive ranging is the process of estimating the distance between an observer (own-ship) and one or more objects (targets) by using passive sensors and angle measurements only, without electromagnetic or acoustic emissions. It is the baseline technique to complete the three dimensional tracking capability of IRST systems, able to automatically search, detect and track targets with generally higher angular resolution than Radars in completely silent mode. As well-known from literature, range is univocally linked to angle only data, when specific relative dynamics occur. In other cases, when such univocal relation does not hold, range estimation is still considered an open research topic. In this paper we select a set of informative cases, derived from our experience in analyzing real sorties data and compare four popular algorithms on the basis of a set of new metrics that, in our opinion, captures the system performance in terms of usability and reliability. Ranging algorithms performance is usually evaluated by means of distance-based metrics (as RMSE) which focus on accuracy of the estimation. Usability and reliability are taken into account here by introducing what we call the Average Range Declaration Length (ARDL) and the Truth-Representative Score (TRS).

  14. Realistic decision-making processes in a vaccination game

    Science.gov (United States)

    Iwamura, Yoshiro; Tanimoto, Jun

    2018-03-01

    Previous studies of vaccination games have nearly always assumed a pairwise comparison between a focal and neighboring player for the strategy updating rule, which comes from numerous compiled studies on spatial versions of 2-player and 2-strategy (2 × 2) games such as the spatial prisoner's dilemma (SPD). We propose, in this study, new update rules because the human decision-making process of whether to commit to a vaccination is obviously influenced by a "sense of crisis" or "fear" urging him/her toward vaccination, otherwise they will likely be infected. The rule assumes that an agent evaluates whether getting a vaccination or trying to free ride should be attempted based on observations of whether neighboring non-vaccinators were able to successfully free ride during the previous time-step. Compared to the conventional updating rule (standard pairwise comparison assuming a Fermi function), the new rules generally realize higher vaccination coverage and smaller final epidemic sizes. One rule in particular shows very good performance with significantly smaller epidemic sizes despite comparable levels of vaccination coverage. This is because the specific update rule helps vaccinators spread widely in the domain, which effectively hampers the spread of epidemics.

  15. 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.

  16. Improving MMR vaccination rates: herd immunity is a realistic goal.

    Science.gov (United States)

    Cockman, Philippa; Dawson, Luise; Mathur, Rohini; Hull, Sally

    2011-10-04

    As measles is a highly infectious disease, the United Kingdom recommendation is for at least 95% of children to receive a first vaccination with the measles, mumps, and rubella (MMR) vaccine before age 2 years and a booster before age 5 years to achieve herd immunity and prevent outbreaks. Reported vaccination rates for England have improved since a low level in 2003-4. Coverage for London is consistently lower than for England, however, and concerns have been expressed that there could be an epidemic of measles in the capital. Observational time series study. London Borough of Tower Hamlets. Key measurements for improvement Uptake rates for childhood vaccinations. The key target was to reach 95% coverage for the first MMR vaccine before age 2 years. Financial support for the development of geographically based networks of general practices. Commissioning of care packages, incentivising delivery of high quality integrated care with network level vaccination targets of 95%. Innovative use of information technology to enable robust call and recall processes, active follow-up of defaulters, and increased knowledge about the demography of the children most difficult to reach. The development of networks of practices facilitated collaborative working among primary care clinicians and other stakeholders; peer review of achievements; and an element of healthy competition. Uptake improved for all childhood vaccinations, and to herd immunity levels for most. Uptake of the first MMR vaccine before age 2 years rose from 80% in September 2009 to 94% in March 2011. Achieving herd immunity for childhood vaccinations is an achievable target in an ethnically mixed, socially deprived inner city borough. The ability to identify characteristics of the difficult to reach groups, including significant differences in uptake across different ethnicities, will allow targeted interventions that may further improve overall coverage.

  17. Realistic deformable 3D numeric phantom for transcutaneous ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Fernando Mitsuyama; Moraes, Matheus Cardoso; Furuie, Sergio Shiguemi, E-mail: fernando.okara@gmail.com [Universidade de Sao Paulo (USP), SP (Brazil). Escola de Engenharia

    2017-01-15

    Introduction: Numerical phantoms are important tools to design, calibrate and evaluate several methods in various image-processing applications, such as echocardiography and mammography. We present a framework for creating ultrasound numerical deformable phantoms based on Finite Element Method (FEM), Linear Isomorphism and Field II. The proposed method considers that the scatterers map is a property of the tissue; therefore, the scatterers should move according to the tissue strain. Methods: First, a volume representing the target tissue is loaded. Second, parameter values, such as Young's Modulus, scatterers density, attenuation and scattering amplitudes are inserted for each different regions of the phantom. Then, other parameters related to the ultrasound equipment, such as ultrasound frequency and number of transducer elements, are also defined in order to perform the ultrasound acquisition using Field II. Third, the size and position of the transducer and the pressures that are applied against the tissue are defined. Subsequently, FEM is executed and deformation is computed. Next, 3D linear isomorphism is performed to displace the scatterers according to the deformation. Finally, Field II is carried out to generate the non-deformed and deformed ultrasound data. Results: The framework is evaluated by comparing strain values obtained the numerical simulation and from the physical phantom from CIRS. The mean difference between both phantoms is lesser than 10%. Conclusion: The acoustic and deformation outcomes are similar to those obtained using a physical phantom. This framework led to a tool, which is available online and free of charges for educational and research purposes. (author)

  18. Realistic three-dimensional sensitivity kernels for local tomography

    Science.gov (United States)

    Zhao, L.; Jordan, T. H.; Olsen, K. B.

    2003-12-01

    The frequency-dependent travel-time and amplitude anomalies measured at stations in the Southern California Seismic Network from local earthquakes carry rich information on the 3-D subsurface structure in and around the LA Basin (P. Chen et al., this meeting). So far tomography inversions for the LA Basin have been based on travel-time data using approximate Fréchet kernels obtained under high-frequency assumption that breaks down when the spatial dimensions of the structural heterogeneities are comparable to the Fresnel-zone size of the seismic waves. We have developed an algorithm to compute the exact 3-D Fréchet kernels for the frequency-dependent travel-time and amplitude anomalies without relying upon the assumptions of a smooth heterogeneity and a simple reference structure. The algorithm uses a staggered-grid finite-difference method to solve the wave equation in 3-D media and the reciprocity to reduce the number of finite-difference simulations. Numerical results for the travel-time and amplitude Fréchet kernels reveal a number of properties: 1) As expected, the sensitivities of both travel time and amplitude of a finite-bandwidth signal such as the usual P or S wave do not concentrate only on the ray path, but spread out in a volume surrounding it. 2) If the measurement is obtained from the entire waveform of a given arrival, e.g. through the cross-correlation of two waveforms, the travel-time kernel exhibits the counter-intuitive banana-doughnut behavior with minimum on the ray path; whereas the amplitude kernel takes on an intuitive shape of a sausage with maximum on the ray path. 3) In the first Fresnel zone, the travel-time sensitivity is mostly negative, indicating an advance in arrival time for a velocity increase, whereas the amplitude sensitivity is positive, suggesting an amplitude reduction for a wave-speed increase. 4) At stations away from the nodal points, the kernels for measurements obtained on different components of the same phase are

  19. A review of toxicity models for realistic atmospheric applications

    Science.gov (United States)

    Gunatilaka, Ajith; Skvortsov, Alex; Gailis, Ralph

    2014-02-01

    There are many applications that need to study human health effects caused by exposure to toxic chemicals. Risk analysis for industrial sites, study of population health impacts of atmospheric pollutants, and operations research for assessing the potential impacts of chemical releases in military contexts are some examples. Because of safety risks and the high cost of field trials involving hazardous chemical releases, computer simulations are widely used for such studies. Modelling of atmospheric transport and dispersion of chemicals released into the atmosphere to determine the toxic chemical concentrations to which individuals will be exposed is one main component of these simulations, and there are well established atmospheric dispersion models for this purpose. Estimating the human health effects caused by the exposure to these predicted toxic chemical concentrations is the other main component. A number of different toxicity models for assessing the health effects of toxic chemical exposure are found in the literature. Because these different models have been developed based on different assumptions about the plume characteristics, chemical properties, and physiological response, there is a need to review and compare these models to understand their applicability. This paper reviews several toxicity models described in the literature. The paper also presents results of applying different toxicity models to simulated concentration time series data. These results show that the use of ensemble mean concentrations, which are what atmospheric dispersion models typically provide, to estimate human health effects of exposure to hazardous chemical releases may underestimate their impact when toxic exponent, n, of the chemical is greater than one; the opposite phenomenon appears to hold when n biological recovery processes may predict greater toxicity than the explicitly parameterised models. Despite the wide variety of models of varying degrees of complexity that is

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

    Science.gov (United States)

    Wolfi, Amelia A; Zavaleta, Erika S

    2015-01-01

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

  1. Beyond the realist turn: a socio-material analysis of heart failure self-care.

    Science.gov (United States)

    McDougall, Allan; Kinsella, Elizabeth Anne; Goldszmidt, Mark; Harkness, Karen; Strachan, Patricia; Lingard, Lorelei

    2018-01-01

    For patients living with chronic illnesses, self-care has been linked with positive outcomes such as decreased hospitalisation, longer lifespan, and improved quality of life. However, despite calls for more and better self-care interventions, behaviour change trials have repeatedly fallen short on demonstrating effectiveness. The literature on heart failure (HF) stands as a case in point, and a growing body of HF studies advocate realist approaches to self-care research and policymaking. We label this trend the 'realist turn' in HF self-care. Realist evaluation and realist interventions emphasise that the relationship between self-care interventions and positive health outcomes is not fixed, but contingent on social context. This paper argues socio-materiality offers a productive framework to expand on the idea of social context in realist accounts of HF self-care. This study draws on 10 interviews as well as researcher reflections from a larger study exploring health care teams for patients with advanced HF. Leveraging insights from actor-network theory (ANT), this study provides two rich narratives about the contextual factors that influence HF self-care. These descriptions portray not self-care contexts but self-care assemblages, which we discuss in light of socio-materiality. © 2018 Foundation for the Sociology of Health & Illness.

  2. Performance assessment of a micro-cogeneration system under realistic operating conditions

    International Nuclear Information System (INIS)

    Rosato, Antonio; Sibilio, Sergio

    2013-01-01

    Highlights: • Performances of a micro-cogeneration system have been experimentally evaluated. • Cogenerator performances have been compared with those of a traditional system. • Measured data have been analyzed from both energy and exergy points of view. - Abstract: The European Parliament stated that high-efficiency cogeneration is a Community priority given the potential benefits of cogeneration with regard to saving primary energy and reducing emissions. According to this position, the performance of many micro-cogeneration systems have been assessed from an energy and environmental point of view. However, in the most part of cases, the assessments have been performed by using technical data from manufacturers and/or experimental results measured during steady-state operation, without considering the inefficiencies related to the transient periods; in addition, few works have been devoted to analyze the system operation from an exergy-based point of view. In this paper the electric load-following operation of an internal combustion engine based micro-cogeneration unit with 6.0 kW as nominal electric output has been experimentally investigated in electric load-following operation during a 24 h dynamic test with the application of a realistic daily load profile representing the Italian domestic non-HVAC electric demand for a multi-family house of five dwellings. The measured data have been compared with those that would be associated with servicing the building with electricity from the central electric grid and heat from a natural gas fired boiler from an energy, exergy and environmental points of view

  3. Toward realistic and practical ideal observer (IO) estimation for the optimization of medical imaging systems.

    Science.gov (United States)

    He, Xin; Caffo, Brian S; Frey, Eric C

    2008-10-01

    The ideal observer (IO) employs complete knowledge of the available data statistics and sets an upper limit on observer performance on a binary classification task. However, the IO test statistic cannot be calculated analytically, except for cases where object statistics are extremely simple. Kupinski have developed a Markov chain Monte Carlo (MCMC) based technique to compute the IO test statistic for, in principle, arbitrarily complex objects and imaging systems. In this work, we applied MCMC to estimate the IO test statistic in the context of myocardial perfusion SPECT (MPS). We modeled the imaging system using an analytic SPECT projector with attenuation, distant-dependent detector-response modeling and Poisson noise statistics. The object is a family of parameterized torso phantoms with variable geometric and organ uptake parameters. To accelerate the imaging simulation process and thus enable the MCMC IO estimation, we used discretized anatomic parameters and continuous uptake parameters in defining the objects. The imaging process simulation was modeled by precomputing projections for each organ for a finite number of discretely-parameterized anatomic parameters and taking linear combinations of the organ projections based on continuous sampling of the organ uptake parameters. The proposed method greatly reduces the computational burden and allows MCMC IO estimation for a realistic MPS imaging simulation. We validated the proposed IO estimation technique by estimating IO test statistics for a large number of input objects. The properties of the first- and second-order statistics of the IO test statistics estimated using the MCMC IO estimation technique agreed well with theoretical predictions. Further, as expected, the IO had better performance, as measured by the receiver operating characteristic (ROC) curve, than the Hotelling observer. This method is developed for SPECT imaging. However, it can be adapted to any linear imaging system.

  4. Realistic calculations for c-coefficients of the isobaric mass multiplet equation in 1 p 0 f shell nuclei

    Science.gov (United States)

    Ormand, Erich; Brown, Alex; Hjorth-Jensen, Morten

    2017-09-01

    We present calculations for the c-coefficients of the isobaric mass multiplet equation for nuclei from A = 42 to A = 54 based on two-body effective interactions derived from three realistic nucleon-nucleon interactions: CD-Bonn, N3LO, and Argonne V18. The two-body effective interactions were derived using G-matrix or Vlowk augmented by perturbation theory extended to third order. We demonstrate a clear dependence in the c-coefficients on the short-ranged charge-symmetry breaking (CSB) part of the strong interaction, which is required to reproduce their overall behavior as a function of excitation (angular momentum). We find, however, that the CSB component in all three realistic nucleon-nucleon interactions is too large when compared to experiment, and that, furthermore, there is significant disagreement between each of the three interactions. This implies either: 1) a deficiency in our understanding of isospin-symmetry breaking in the nucleon-nucleon interaction, 2) significant isospin-symmetry breaking in the initial three-nucleon interaction, or 3) large contributions to isospin-symmetry breaking in three-nucleon interactions induced by the renormalization procedure. This work performed for the U.S. DOE by LLNL under Contract DE-AC52-07NA27344. WEO: DOE/NP FWP SCW0498. BAB: NSF Grant No. PHY-1404442. MHJ: NSF Grant No. PHY-1404159 and the Research Council of Norway contract ISP-Fysikk/216699.

  5. Development and validation of a biologically realistic tissue-mimicking material for photoacoustics and other bimodal optical-acoustic modalities

    Science.gov (United States)

    Vogt, William C.; Jia, Congxian; Wear, Keith A.; Garra, Brian S.; Pfefer, T. Joshua

    2017-03-01

    Recent years have seen rapid development of hybrid optical-acoustic imaging modalities with broad applications in research and clinical imaging, including photoacoustic tomography (PAT), photoacoustic microscopy, and ultrasound-modulated optical tomography. Tissue-mimicking phantoms are an important tool for objectively and quantitatively simulating in vivo imaging system performance. However, no standard tissue phantoms exist for such systems. One major challenge is the development of tissue-mimicking materials (TMMs) that are both highly stable and possess biologically realistic properties. To address this need, we have explored the use of various formulations of PVC plastisol (PVCP) based on varying mixtures of several liquid plasticizers. We developed a custom PVCP formulation with optical absorption and scattering coefficients, speed of sound, and acoustic attenuation that are tunable and tissue-relevant. This TMM can simulate different tissue compositions and offers greater mechanical strength than hydrogels. Optical properties of PVCP samples with varying composition were characterized using integrating sphere spectrophotometry and the inverse adding-doubling method. Acoustic properties were determined using a broadband pulse-transmission technique. To demonstrate the utility of this bimodal TMM, we constructed an image quality phantom designed to enable quantitative evaluation of PAT spatial resolution. The phantom was imaged using a custom combined PAT-ultrasound imaging system. Results indicated that this more biologically realistic TMM produced performance trends not captured in simpler liquid phantoms. In the future, this TMM may be broadly utilized for performance evaluation of optical, acoustic, and hybrid optical-acoustic imaging systems.

  6. Using the realist perspective to link theory from qualitative evidence synthesis to quantitative studies: Broadening the matrix approach.

    Science.gov (United States)

    van Grootel, Leonie; van Wesel, Floryt; O'Mara-Eves, Alison; Thomas, James; Hox, Joop; Boeije, Hennie

    2017-09-01

    This study describes an approach for the use of a specific type of qualitative evidence synthesis in the matrix approach, a mixed studies reviewing method. The matrix approach compares quantitative and qualitative data on the review level by juxtaposing concrete recommendations from the qualitative evidence synthesis against interventions in primary quantitative studies. However, types of qualitative evidence syntheses that are associated with theory building generate theoretical models instead of recommendations. Therefore, the output from these types of qualitative evidence syntheses cannot directly be used for the matrix approach but requires transformation. This approach allows for the transformation of these types of output. The approach enables the inference of moderation effects instead of direct effects from the theoretical model developed in a qualitative evidence synthesis. Recommendations for practice are formulated on the basis of interactional relations inferred from the qualitative evidence synthesis. In doing so, we apply the realist perspective to model variables from the qualitative evidence synthesis according to the context-mechanism-outcome configuration. A worked example shows that it is possible to identify recommendations from a theory-building qualitative evidence synthesis using the realist perspective. We created subsets of the interventions from primary quantitative studies based on whether they matched the recommendations or not and compared the weighted mean effect sizes of the subsets. The comparison shows a slight difference in effect sizes between the groups of studies. The study concludes that the approach enhances the applicability of the matrix approach. Copyright © 2017 John Wiley & Sons, Ltd.

  7. Regional 3-D Modeling of Ground Geoelectric Field for the Northeast United States due to Realistic Geomagnetic Disturbances

    Science.gov (United States)

    Ivannikova, E.; Kruglyakov, M.; Kuvshinov, A. V.; Rastaetter, L.; Pulkkinen, A. A.; Ngwira, C. M.

    2017-12-01

    During extreme space weather events electric currents in the Earth's magnetosphere and ionosphere experience large variations, which leads to dramatic intensification of the fluctuating magnetic field at the surface of the Earth. According to Faraday's law of induction, the fluctuating geomagnetic field in turn induces electric field that generates harmful currents (so-called "geomagnetically induced currents"; GICs) in grounded technological systems. Understanding (via modeling) of the spatio-temporal evolution of the geoelectric field during enhanced geomagnetic activity is a key consideration in estimating the hazard to technological systems from space weather. We present the results of ground geoelectric field modeling for the Northeast United States, which is performed with the use of our novel numerical tool based on integral equation approach. The tool exploits realistic regional three-dimensional (3-D) models of the Earth's electrical conductivity and realistic global models of the spatio-temporal evolution of the magnetospheric and ionospheric current systems responsible for geomagnetic disturbances. We also explore in detail the manifestation of the coastal effect (anomalous intensification of the geoelectric field near the coasts) in this region.

  8. 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

  9. A realist evaluation of social prescribing: an exploration into the context and mechanisms underpinning a pathway linking primary care with the voluntary sector.

    Science.gov (United States)

    Bertotti, Marcello; Frostick, Caroline; Hutt, Patrick; Sohanpal, Ratna; Carnes, Dawn

    2018-05-01

    This article adopts a realist approach to evaluate a social prescribing pilot in the areas of Hackney and City in London (United Kingdom). It unpacks the contextual factors and mechanisms that influenced the development of this pilot for the benefits of GPs, commissioners and practitioners, and reflects on the realist approach to evaluation as a tool for the evaluation of health interventions. Primary care faces considerable challenges including the increase in long-term conditions, GP consultation rates, and widening health inequalities. With its emphasis on linking primary care to non-clinical community services via a social prescribing coordinator (SPC), some models of social prescribing could contribute to reduce the burden on primary care, tackle health inequalities and encourage people to make greater use of non-clinical forms of support. This realist analysis was based on qualitative interviews with users, commissioners, a GP survey, focus groups and learning events to explore stakeholders' experience. To enable a detailed analysis, we adapted the realist approach by subdividing the social prescribing pathway into stages, each with contextual factors, mechanisms and outcomes. SPCs were pivotal to the effective functioning of the social prescribing service and responsible for the activation and initial beneficial impact on users. Although social prescribing shows significant potential for the benefit of patients and primary care, several challenges need to be considered and overcome, including 'buy in' from some GPs, branding, and funding for the third sector in a context where social care cuts are severely affecting the delivery of health care. With its emphasis on context and mechanisms, the realist evaluation approach is useful in understanding how to identify and improve health interventions, and analyse in greater detail the contribution of different stakeholders. As the SPC is central to social prescribing, more needs to be done to understand their role

  10. 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.

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

    OpenAIRE

    Jukka Mikkonen

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

    1988-01-01

    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

  13. Toward the M(F)--Theory Embedding of Realistic Free-Fermion Models

    CERN Document Server

    Berglund, P; Faraggi, A E; Nanopoulos, Dimitri V; Qiu, Z; Berglund, Per; Ellis, John; Faraggi, Alon E.; Qiu, Zongan

    1998-01-01

    We construct a Landau-Ginzburg model with the same data and symmetries as a $Z_2\\times Z_2$ orbifold that corresponds to a class of realistic free-fermion models. Within the class of interest, we show that this orbifolding connects between different $Z_2\\times Z_2$ orbifold models and commutes with the mirror symmetry. Our work suggests that duality symmetries previously discussed in the context of specific $M$ and $F$ theory compactifications may be extended to the special $Z_2\\times Z_2$ orbifold that characterizes realistic free-fermion models.

  14. Conjugate problems of transport phenomena under quasi-steady microaccelerations in realistic spaceflight.

    Science.gov (United States)

    Polezhaev, V I; Nikitin, S A

    2009-04-01

    A new model for spatial convective transport processes conjugated with the measured or calculated realistic quasi-steady microaccelerations is presented. Rotation around the mass center, including accelerated rotation, gravity gradient, and aerodynamical drag are taken into account. New results of the effect on mixing and concentration inhomogeneities of the elementary convective processes are presented. The mixing problem in spacecraft enclosures, concentration inhomogeneities due to convection induced by body forces in realistic spaceflight, and the coupling of this kind of convection with thermocapillary convection on the basis of this model are discussed.

  15. 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.

  16. Remote vital parameter monitoring in neonatology - robust, unobtrusive heart rate detection in a realistic clinical scenario.

    Science.gov (United States)

    Blanik, Nikolai; Heimann, Konrad; Pereira, Carina; Paul, Michael; Blazek, Vladimir; Venema, Boudewijn; Orlikowsky, Thorsten; Leonhardt, Steffen

    2016-12-01

    Vital parameter monitoring of term and preterm infants during incubator care with self-adhesive electrodes or sensors directly positioned on the skin [e.g. photoplethysmography (PPG) for oxygen saturation or electrocardiography (ECG)] is an essential part of daily routine care in neonatal intensive care units. For various reasons, this kind of monitoring contains a lot of stress for the infants. Therefore, there is a need to measure vital parameters (for instance respiration, temperature, pulse, oxygen saturation) without mechanical or conductive contact. As a non-contact method of monitoring, we present an adapted version of camera-based photoplethysmography imaging (PPGI) according to neonatal requirements. Similar to classic PPG, the PPGI camera detects small temporal changes in the term and preterm infant's skin brightness due to the cardiovascular rhythm of dermal blood perfusion. We involved 10 preterm infants in a feasibility study [five males and five females; mean gestational age: 26 weeks (24-28 weeks); mean biological age: 35 days (8-41 days); mean weight at the time of investigation: 960 g (670-1290 g)]. The PPGI camera was placed directly above the incubators with the infant inside illuminated by an infrared light emitting diode (LED) array (850 nm). From each preterm infant, 5-min video sequences were recorded and analyzed post hoc. As the measurement scenario was kept as realistic as possible, the infants were not constrained in their movements in front of the camera. Movement intensities were assigned into five classes (1: no visible motion to 5: heavy struggling). PPGI was found to be significantly sensitive to movement artifacts. However, for movement classes 1-4, changes in blood perfusion according to the heart rate (HR) were recovered successfully (Pearson correlation: r=0.9759; r=0.765 if class 5 is included). The study was approved by the Ethics Committee of the Universal Hospital of the RWTH Aachen University, Aachen, Germany (EK 254/13).

  17. 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.

  18. 'Including health in systems responsible for urban planning': a realist policy analysis research programme.

    Science.gov (United States)

    Harris, Patrick; Friel, Sharon; Wilson, Andrew

    2015-07-23

    Realist methods are increasingly being used to investigate complex public health problems. Despite the extensive evidence base clarifying the built environment as a determinant of health, there is limited knowledge about how and why land-use planning systems take on health concerns. Further, the body of research related to the wider determinants of health suffers from not using political science knowledge to understand how to influence health policy development and systems. This 4-year funded programme of research investigates how the land-use planning system in New South Wales, Australia, incorporates health and health equity at multiple levels. The programme uses multiple qualitative methods to develop up to 15 case studies of different activities of the New South Wales land-use planning system. Comparison cases from other jurisdictions will be included where possible and useful. Data collection includes publicly available documentation and purposively sampled stakeholder interviews and focus groups of up to 100 participants across the cases. The units of analysis in each case are institutional structures (rules and mandates constraining and enabling actors), actors (the stakeholders, organisations and networks involved, including health-focused agencies), and ideas (policy content, information, and framing). Data analysis will focus on and develop propositions concerning the mechanisms and conditions within and across each case leading to inclusion or non-inclusion of health. Data will be refined using additional political science and sociological theory. Qualitative comparative analysis will compare cases to develop policy-relevant propositions about the necessary and sufficient conditions needed to include health issues. Ethics has been approved by Sydney University Human Research Ethics Committee (2014/802 and 2015/178). Given the nature of this research we will incorporate stakeholders, often as collaborators, throughout. We outline our research translation

  19. Idealized vs. Realistic Microstructures: An Atomistic Simulation Case Study on γ/γ′ Microstructures

    Directory of Open Access Journals (Sweden)

    Aruna Prakash

    2017-01-01

    Full Text Available Single-crystal Ni-base superalloys, consisting of a two-phase γ/ γ ′ microstructure, retain high strengths at elevated temperatures and are key materials for high temperature applications, like, e.g., turbine blades of aircraft engines. The lattice misfit between the γ and γ ′ phases results in internal stresses, which significantly influence the deformation and creep behavior of the material. Large-scale atomistic simulations that are often used to enhance our understanding of the deformation mechanisms in such materials must accurately account for such misfit stresses. In this work, we compare the internal stresses in both idealized and experimentally-informed, i.e., more realistic, γ/ γ ′ microstructures. The idealized samples are generated by assuming, as is frequently done, a periodic arrangement of cube-shaped γ ′ particles with planar γ/ γ ′ interfaces. The experimentally-informed samples are generated from two different sources to produce three different samples—the scanning electron microscopy micrograph-informed quasi-2D atomistic sample and atom probe tomography-informed stoichiometric and non-stoichiometric atomistic samples. Additionally, we compare the stress state of an idealized embedded cube microstructure with finite element simulations incorporating 3D periodic boundary conditions. Subsequently, we study the influence of the resulting stress state on the evolution of dislocation loops in the different samples. The results show that the stresses in the atomistic and finite element simulations are almost identical. Furthermore, quasi-2D boundary conditions lead to a significantly different stress state and, consequently, different evolution of the dislocation loop, when compared to samples with fully 3D boundary conditions.

  20. Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

    Science.gov (United States)

    Maneas, Efthymios; Xia, Wenfeng; Nikitichev, Daniil I.; Daher, Batol; Manimaran, Maniragav; Wong, Rui Yen J.; Chang, Chia-Wei; Rahmani, Benyamin; Capelli, Claudio; Schievano, Silvia; Burriesci, Gaetano; Ourselin, Sebastien; David, Anna L.; Finlay, Malcolm C.; West, Simeon J.; Vercauteren, Tom; Desjardins, Adrien E.

    2018-01-01

    Here we describe methods for creating tissue-mimicking ultrasound phantoms based on patient anatomy using a soft material called gel wax. To recreate acoustically realistic tissue properties, two additives to gel wax were considered: paraffin wax to increase acoustic attenuation, and solid glass spheres to increase backscattering. The frequency dependence of ultrasound attenuation was well described with a power law over the measured range of 3–10 MHz. With the addition of paraffin wax in concentrations of 0 to 8 w/w%, attenuation varied from 0.72 to 2.91 dB cm‑1 at 3 MHz and from 6.84 to 26.63 dB cm‑1 at 10 MHz. With solid glass sphere concentrations in the range of 0.025–0.9 w/w%, acoustic backscattering consistent with a wide range of ultrasonic appearances was achieved. Native gel wax maintained its integrity during compressive deformations up to 60%; its Young’s modulus was 17.4  ±  1.4 kPa. The gel wax with additives was shaped by melting and pouring it into 3D printed moulds. Three different phantoms were constructed: a nerve and vessel phantom for peripheral nerve blocks, a heart atrium phantom, and a placental phantom for minimally-invasive fetal interventions. In the first, nerves and vessels were represented as hyperechoic and hypoechoic tubular structures, respectively, in a homogeneous background. The second phantom comprised atria derived from an MRI scan of a patient with an intervening septum and adjoining vena cavae. The third comprised the chorionic surface of a placenta with superficial fetal vessels derived from an image of a post-partum human placenta. Gel wax is a material with widely tuneable ultrasound properties and mechanical characteristics that are well suited for creating patient-specific ultrasound phantoms in several clinical disciplines.

  1. Assessment of vectorial total variation penalties on realistic dual-energy CT data

    Science.gov (United States)

    Rigie, David S.; Sanchez, Adrian A.; La Rivière, Patrick J.

    2017-04-01

    Vectorial extensions of total variation have recently been developed for regularizing the reconstruction and denoising of multi-channel images, such as those arising in spectral computed tomography. Early studies have focused mainly on simulated, piecewise-constant images whose structure may favor total-variation penalties. In the current manuscript, we apply vectorial total variation to real dual-energy CT data of a whole turkey in order to determine if the same benefits can be observed in more complex images with anatomically realistic textures. We consider the total nuclear variation (\\text{T}{{\\text{V}}\\text{N}} ) as well as another vectorial total variation based on the Frobenius norm (\\text{T}{{\\text{V}}\\text{F}} ) and standard channel-by-channel total variation (\\text{T}{{\\text{V}}\\text{S}} ). We performed a series of 3D TV denoising experiments comparing the three TV variants across a wide range of smoothness parameter settings, optimizing each regularizer according to a very-high-dose ‘ground truth’ image. Consistent with the simulation studies, we find that both vectorial TV variants achieve a lower error than the channel-by-channel TV and are better able to suppress noise while preserving actual image features. In this real data study, the advantages are subtler than in the previous simulation study, although the \\text{T}{{\\text{V}}\\text{N}} penalty is found to have clear advantages over either \\text{T}{{\\text{V}}\\text{S}} or \\text{T}{{\\text{V}}\\text{F}} when comparing material images formed from linear combinations of the denoised energy images.

  2. 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

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

    DEFF Research Database (Denmark)

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

    realistic pulse exposure and concentration of a pyrethroid pesticide, permethrin, on the freshwater amphipod Hyalella azteca. Permethrin is a pyrethroid insecticide used in mosquito control and to control a wide range of insect pests on various crops and is known to be highly toxic to aquatic invertebrates...

  4. CASCADE-IMEI: Web site support for student teachers learning Realistic Mathematics Education (RME) in Indonesia

    NARCIS (Netherlands)

    Zulkardi, Z.; Nieveen, N.M.

    2001-01-01

    CASCADE-IMEI is a learning environment in the form of a face-to-face course and a web site (www.cascadeimei.com) which aims to support student teachers in Indonesia to learn Realistic Mathematics Education (RME). RME is an instructional theory in mathematics education that was originally developed

  5. 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…

  6. Developing a learning environment on realistic mathematics education for Indonesian student teachers

    NARCIS (Netherlands)

    Zulkardi, Z.

    2002-01-01

    The CASCADE-IMEI study was started to explore the role of a learning environment (LE) in assisting mathematics student teachers learning Realistic Mathematics Education (RME) as a new instructional approach in mathematics education in Indonesia. The LE for this study has been developed and evaluated

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

    NARCIS (Netherlands)

    Formsma, O.; Dijkshoorn, N.; van Noort, S.; Visser, A.; Ruiz-del-Solar, J.; Chown, E.; Plöger, P.G.

    2011-01-01

    The Urban Search and Rescue Simulation used for RoboCup lacks realistic response of laser range finders on smoke. In this paper, the behavior of a Hokuyo and Sick laser range finder in a smoky environment is studied. The behavior of the lasers is among others a function of the visibility level, and

  8. A rapid algorithm for realistic human reaching and its use in a virtual reality system

    Science.gov (United States)

    Aldridge, Ann; Pandya, Abhilash; Goldsby, Michael; Maida, James

    1994-01-01

    The Graphics Analysis Facility (GRAF) at JSC has developed a rapid algorithm for computing realistic human reaching. The algorithm was applied to GRAF's anthropometrically correct human model and used in a 3D computer graphics system and a virtual reality system. The nature of the algorithm and its uses are discussed.

  9. An unexpected patron: A social-scientific and realistic reading of the ...

    African Journals Online (AJOL)

    An unexpected patron: A social-scientific and realistic reading of the parable of the Vineyard Labourers (Mt 20:1–15). Ernest van Eck, John S. Kloppenborg. Abstract. Many readings of the Parable of the Labourers in the vineyard want to treat the owner as representing God. Knowledge of actual agricultural practices relating ...

  10. Depictions and Gaps: Portrayal of U.S. Poverty in Realistic Fiction Children's Picture Books

    Science.gov (United States)

    Kelley, Jane E.; Darragh, Janine J.

    2011-01-01

    Researchers conducted a critical multicultural analysis of 58 realistic fiction children's picture books that portray people living in poverty and compared these depictions to recent statistics from the United States Census Bureau. The picture books were examined for the following qualities: main character, geographic locale and time era, focal…

  11. Middle Grade Students' Responses to Canadian Realistic Fiction for Young Adults.

    Science.gov (United States)

    Latshaw, Jessica L. K.

    1991-01-01

    Student responses to Canadian realistic fiction for young adults were examined for four seventh grade girls and three seventh grade boys. Interview findings support the view that students should have a role in selecting what they read, should talk about reading informally, and should construct representations less influenced by teacher responses.…

  12. Are These Parents for Real? Students' Views of Parents in Realistic and Historical Fiction.

    Science.gov (United States)

    Harmon, Janis M.; Gonzales, Monica C.

    2003-01-01

    Describes what students had to say about parental roles. Includes students' views about parental roles in real life, their expectations of parental roles in realistic and historical novels, their impressions of the parents they encountered in the selected books, and a comparison across genres about these parental characters. Presents guidelines…

  13. Heroes and Victims: The Stereotyping of Animal Characters in Children's Realistic Animal Fiction.

    Science.gov (United States)

    Oswald, Lori Jo

    1995-01-01

    Discusses portrayals of animals in children's realistic animal fiction over the course of the 20th century. Shows how the definition of animal hero generally changed from wild animals that were heroic for surviving against all odds to domesticated animals that were heroic for rescuing humans from wild beasts. Discusses animals as victims. (SR)

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

    NARCIS (Netherlands)

    Zulkardi, Z.; Nieveen, N.M.

    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

  15. The standing wave FEL/TBA: Realistic cavity geometry and energy extraction

    International Nuclear Information System (INIS)

    Kim, Jin-Soo, Henke, H.; Sessler, A.M.; Sharp, W.M.

    1993-05-01

    A set of parameters for standing wave free electron laser two beam accelerators (SWFEL/TBA) is evaluated for realistic cavity geometry taking into account beam-break-up and the sensitivity of output power to imperfections. Also given is a power extraction system using cavity coupled wave guides

  16. The tenants in the vineyard (GThom 65/Mark 12:1-12): A realistic ...

    African Journals Online (AJOL)

    Kloppenborg's reading of the parable of the tenants (Mk 12:1- 12/GThom 65) can be regarded as the first thoroughgoing realistic interpretation of the Tenants. By using extensive literary evidence on viticulture from 300 BCE to 300 CE, Kloppenborg argues that GThom 65 most probably comes closest to the original form of ...

  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.

  18. 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...

  19. Phenomenology of a realistic accelerating universe using tracker fields

    Indian Academy of Sciences (India)

    We present a realistic scenario of tracking of scalar fields with varying equation of state. The astrophysical constraints on the evolution of scalar fields in the physical universe are discussed. The nucleosynthesis and the galaxy formation constraints have been used to put limits on and estimate during cosmic evolution.

  20. How economic crises affect alcohol consumption and alcohol-related health problems: a realist systematic review

    NARCIS (Netherlands)

    de Goeij, Moniek C. M.; Suhrcke, Marc; Toffolutti, Veronica; van de Mheen, Dike; Schoenmakers, Tim M.; Kunst, Anton E.

    2015-01-01

    Economic crises are complex events that affect behavioral patterns (including alcohol consumption) via opposing mechanisms. With this realist systematic review, we aimed to investigate evidence from studies of previous or ongoing crises on which mechanisms (How?) play a role among which individuals

  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

  2. 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;…

  3. Developing a realistic-prototyping road user cost evaluation tool for FDOT.

    Science.gov (United States)

    2008-12-31

    The objective of this project is to develop a realistic-prototyping RUC (Road User Cost) calculation tool that is userfriendly : and utilizing limited number of data inputs that are easy to use. The tool can help engineers to estimate RUC on : specif...

  4. 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…

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

    Directory of Open Access Journals (Sweden)

    Lionel Roques

    Full Text Available 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.

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

    Science.gov (United States)

    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

  7. 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.

  8. Rapidly re-computable EEG (electroencephalography) forward models for realistic head shapes

    Energy Technology Data Exchange (ETDEWEB)

    Ermer, J. J. (John J.); Mosher, J. C. (John C.); Baillet, S. (Sylvain); Leahy, R. M. (Richard M.)

    2001-01-01

    Solution of the EEG source localization (inverse) problem utilizing model-based methods typically requires a significant number of forward model evaluations. For subspace based inverse methods like MUSIC [6], the total number of forward model evaluations can often approach an order of 10{sup 3} or 10{sup 4}. Techniques based on least-squares minimization may require significantly more evaluations. The observed set of measurements over an M-sensor array is often expressed as a linear forward spatio-temporal model of the form: F = GQ + N (1) where the observed forward field F (M-sensors x N-time samples) can be expressed in terms of the forward model G, a set of dipole moment(s) Q (3xP-dipoles x N-time samples) and additive noise N. Because of their simplicity, ease of computation, and relatively good accuracy, multi-layer spherical models [7] (or fast approximations described in [1], [7]) have traditionally been the 'forward model of choice' for approximating the human head. However, approximation of the human head via a spherical model does have several key drawbacks. By its very shape, the use of a spherical model distorts the true distribution of passive currents in the skull cavity. Spherical models also require that the sensor positions be projected onto the fitted sphere (Fig. 1), resulting in a distortion of the true sensor-dipole spatial geometry (and ultimately the computed surface potential). The use of a single 'best-fitted' sphere has the added drawback of incomplete coverage of the inner skull region, often ignoring areas such as the frontal cortex. In practice, this problem is typically countered by fitting additional sphere(s) to those region(s) not covered by the primary sphere. The use of these additional spheres results in added complication to the forward model. Using high-resolution spatial information obtained via X-ray CT or MR imaging, a realistic head model can be formed by tessellating the head into a set of contiguous

  9. Developing a framework for a novel multi-disciplinary, multi-agency intervention(s), to improve medication management in community-dwelling older people on complex medication regimens (MEMORABLE)--a realist synthesis.

    Science.gov (United States)

    Maidment, Ian; Booth, Andrew; Mullan, Judy; McKeown, Jane; Bailey, Sylvia; Wong, Geoffrey

    2017-07-03

    Medication-related adverse events have been estimated to be responsible for 5700 deaths and cost the UK £750 million annually. This burden falls disproportionately on older people. Outcomes from interventions to optimise medication management are caused by multiple context-sensitive mechanisms. The MEdication Management in Older people: REalist Approaches BAsed on Literature and Evaluation (MEMORABLE) project uses realist synthesis to understand how, why, for whom and in what context interventions, to improve medication management in older people on complex medication regimes residing in the community, work. This realist synthesis uses secondary data and primary data from interviews to develop the programme theory. A realist logic of analysis will synthesise data both within and across the two data sources to inform the design of a complex intervention(s) to help improve medication management in older people. 1. Literature review The review (using realist synthesis) contains five stages to develop an initial programme theory to understand why processes are more or less successful and under which situations: focussing of the research question; developing the initial programme theory; developing the search strategy; selection and appraisal based on relevance and rigour; and data analysis/synthesis to develop and refine the programme theory and context, intervention and mechanism configurations. 2. Realist interviews Realist interviews will explore and refine our understanding of the programme theory developed from the realist synthesis. Up to 30 older people and their informal carers (15 older people with multi-morbidity, 10 informal carers and 5 older people with dementia), and 20 care staff will be interviewed. 3. Developing framework for the intervention(s) Data from the realist synthesis and interviews will be used to refine the programme theory for the intervention(s) to identify: the mechanisms that need to be 'triggered', and the contexts related to these

  10. Hyper-realistic face masks: a new challenge in person identification.

    Science.gov (United States)

    Sanders, Jet Gabrielle; Ueda, Yoshiyuki; Minemoto, Kazusa; Noyes, Eilidh; Yoshikawa, Sakiko; Jenkins, Rob

    2017-01-01

    We often identify people using face images. This is true in occupational settings such as passport control as well as in everyday social environments. Mapping between images and identities assumes that facial appearance is stable within certain bounds. For example, a person's apparent age, gender and ethnicity change slowly, if at all. It also assumes that deliberate changes beyond these bounds (i.e., disguises) would be easy to spot. Hyper-realistic face masks overturn these assumptions by allowing the wearer to look like an entirely different person. If unnoticed, these masks break the link between facial appearance and personal identity, with clear implications for applied face recognition. However, to date, no one has assessed the realism of these masks, or specified conditions under which they may be accepted as real faces. Herein, we examined incidental detection of unexpected but attended hyper-realistic masks in both photographic and live presentations. Experiment 1 (UK; n = 60) revealed no evidence for overt detection of hyper-realistic masks among real face photos, and little evidence of covert detection. Experiment 2 (Japan; n = 60) extended these findings to different masks, mask-wearers and participant pools. In Experiment 3 (UK and Japan; n = 407), passers-by failed to notice that a live confederate was wearing a hyper-realistic mask and showed limited evidence of covert detection, even at close viewing distance (5 vs. 20 m). Across all of these studies, viewers accepted hyper-realistic masks as real faces. Specific countermeasures will be required if detection rates are to be improved.

  11. Squeezing based on nondegenerate frequency doubling internal to a realistic laser

    DEFF Research Database (Denmark)

    Andersen, Ulrik Lund; Tidemand-Lichtenberg, Peter; Buchhave, Preben

    2004-01-01

    We investigate theoretically the quantum fluctuations of the fundamental field in the output of a nondegenerate second-harmonic generation process occurring inside a laser cavity. Due to the nondegenerate character of the nonlinear medium, a field orthogonal to the laser field is for some operating...... conditions independent of the fluctuations produced by the laser medium. We show that this fact may lead to perfect squeezing for a certain polarization mode of the fundamental field. The experimental feasibility of the system is also discussed....

  12. From Workshops to Walkshops: Evaluating Mobile Locastion-Based Applications in Realistic Settings

    DEFF Research Database (Denmark)

    Korn, Matthias; Zander, Pär-Ola

    2010-01-01

    -aware systems). We report some problems with workshops and outline how a walkshop may be carried out. The first trials of the new method are promising and have generated valuable feedback, insights and discussions about using the mobile application within the intended contexts. Many open questions on how...... with workshops and outline how a walkshop may be carried out. The first trials of the new method are promising and have generated valuable feedback, insights and discussions about using the mobile application within the intended contexts....

  13. Efficient PDE based numerical estimation of credit and liquidity risk measures for realistic derivative portfolios

    NARCIS (Netherlands)

    de Graaf, C.S.L.

    2016-01-01

    In the Basel III accords in 2013, it was stated that financial institutions should charge Credit Value Adjustment (CVA) to their counterparties for (previously under-regulated) Over-The-Counter (OTC) trades. This CVA can be used to hedge a possible default of the counterparty. One important

  14. 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.

  15. Visualizing Our Options for Coastal Places: Exploring Realistic Immersive Geovisualizations as Tools for Inclusive Approaches to Coastal Planning and Management

    Directory of Open Access Journals (Sweden)

    Robert Newell

    2017-09-01

    Full Text Available Effective coastal planning is inclusive and incorporates the variety of user needs, values and interests associated with coastal environments. Realistic, immersive geographic visualizations, i.e., geovisualizations, can serve as potentially powerful tools for facilitating such planning because they can provide diverse groups with vivid understandings of how they would feel about certain management outcomes or impacts if transpired in real places. However, the majority of studies in this area have focused on terrestrial environments, and research on applications of such tools in the coastal and marine contexts is in its infancy. The current study aims to advance such research by examining the potential a land-to-sea geovisualization has to serve as a tool for inclusive coastal planning efforts. The research uses Sidney Spit Park (BC, Canada as a study site, and a realistic, dynamic geovisualization of the park was developed (using Unity3D that allows users to interact with and navigate it through the first-person perspective. Management scenarios were developed based on discussions with Parks Canada, and these scenarios included fencing around vegetation areas, positioning of mooring buoys, and management of dog activity within the park. Scenarios were built into the geovisualization in a manner that allows users to toggle different options. Focus groups were then assembled, involving residents of the Capital Regional District (BC, Canada, and participants explored and provided feedback on the scenarios. Findings from the study demonstrate the geovisualization's usefulness for assessing certain qualities of scenarios, such as aesthetics and functionality of fencing options and potential viewshed impacts associated with different mooring boat locations. In addition, the study found that incorporating navigability into the geovisualization proved to be valuable for understanding scenarios that hold implications for the marine environment due to

  16. 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

  17. Estimation of Signal-to-Noise Ratios in Realistic Sound Scenarios.

    Science.gov (United States)

    Smeds, Karolina; Wolters, Florian; Rung, Martin

    2015-02-01

    Both in the design of hearing-device features, such as noise reduction, and in the evaluation measurements of such features, there is a need for more information about the sound scenarios hearing-device users encounter. The limitations of adaptive speech tests as outcome measures in the evaluation of hearing-device features have been discussed. The obvious alternative to adaptive speech testing is to test at a fixed signal-to-noise ratio (SNR). However, the question is which SNRs should be used if the test reflects real-life situations. The purpose of this study was to estimate SNRs in realistic sound environments encountered by hearing aid users. Research design was a descriptive study where recorded sound files were statistically analyzed. A total of 20 experienced, bilaterally fitted hearing aid users, all satisfied with their current hearing aids, made recordings for 3-4 days. The informants were instructed to record different situations in daily life and were told that all situations were of equal importance. The informants ranged in age from 18-81 yr old, and they had various occupations and varying hearing-loss configurations. The total duration of the recorded material for each informant was, on average, 84 min; the number of recordings was, on average, 17 per informant. The sound files were categorized based on the type of background noise and were analyzed with use of a manual noise estimation procedure. Segments of speech with noise present were cut out from the original recordings. Corresponding noise-only segments were also extracted. On the basis of power calculations for these two types of recorded segments, the SNR was estimated. Frequency-specific and overall SNRs, calculated both based on unweighted and A-weighted speech and noise levels, were derived. An estimation uncertainty measure was also developed. The range of SNRs found in the material was large. The most striking finding was that there were very few recorded situations where the SNR was

  18. Can a grain size-dependent viscosity help yielding realistic seismic velocities of LLSVPs?

    Science.gov (United States)

    Schierjott, J.; Cheng, K. W.; Rozel, A.; Tackley, P. J.

    2017-12-01

    Seismic studies show two antipodal regions of low shear velocity at the core-mantle boundary (CMB), one beneath the Pacific and one beneath Africa. These regions, called Large Low Shear Velocity Provinces (LLSVPs), are thought to be thermally and chemically distinct and thus have a different density and viscosity. Whereas there is some general consensus about the density of the LLSVPs the viscosity is still a very debated topic. So far, in numerical studies the viscosity is treated as either depth- and/or temperature- dependent but the potential grain size- dependence of the viscosity is neglected most of the time. In this study we use a self-consistent convection model which includes a grain size- dependent rheology based on the approach by Rozel et al. (2011) and Rozel (2012). Further, we consider a primordial layer and a time-dependent basalt production at the surface to dynamically form the present-day chemical heterogeneities, similar to earlier studies, e.g by Nakagawa & Tackley (2014). With this model we perform a parameter study which includes different densities and viscosities of the imposed primordial layer. We detect possible thermochemical piles based on different criterions, compute their average effective viscosity, density, rheology and grain size and investigate which detecting criterion yields the most realistic results. Our preliminary results show that a higher density and/or viscosity of the piles is needed to keep them at the core-mantle boundary (CMB). Relatively to the ambient mantle grain size is high in the piles but due to the temperature at the CMB the viscosity is not remarkably different than the one of ordinary plumes. We observe that grain size is lower if the density of the LLSVP is lower than the one of our MORB material. In that case the average temperature of the LLSVP is also reduced. Interestingly, changing the reference viscosity is responsible for a change in the average viscosity of the LLSVP but not for a different average

  19. The effects of interventions targeting multiple health behaviors on smoking cessation outcomes: a rapid realist review protocol.

    Science.gov (United States)

    Minian, Nadia; deRuiter, Wayne K; Lingam, Mathangee; Corrin, Tricia; Dragonetti, Rosa; Manson, Heather; Taylor, Valerie H; Zawertailo, Laurie; Ebnahmady, Arezoo; Melamed, Osnat C; Rodak, Terri; Hahn, Margaret; Selby, Peter

    2018-03-01

    Health behaviors directly impact the health of individuals, and populations. Since individuals tend to engage in multiple unhealthy behaviors such as smoking, excessive alcohol use, physical inactivity, and eating an unhealthy diet simultaneously, many large community-based interventions have been implemented to reduce the burden of disease through the modification of multiple health behaviors. Smoking cessation can be particularly challenging as the odds of becoming dependent on nicotine increase with every unhealthy behavior a smoker exhibits. This paper presents a protocol for a rapid realist review which aims to identify factors associated with effectively changing tobacco use and target two or more additional unhealthy behaviors. An electronic literature search will be conducted using the following bibliographic databases: MEDLINE, Embase, PsycINFO, Cumulative Index to Nursing and Allied Health Literature (CINAHL), The Cochrane Library, Social Science Abstracts, Social Work Abstracts, and Web of Science. Two reviewers will screen titles and abstracts for relevant research, and the selected full papers will be used to extract data and assess the quality of evidence. Throughout this process, the rapid realist approach proposed by Saul et al., 2013 will be used to refine our initial program theory and identify contextual factors and mechanisms that are associated with successful multiple health behavior change. This review will provide evidence-based research on the context and mechanisms that may drive the success or failure of interventions designed to support multiple health behavior change. This information will be used to guide curriculum and program development for a government funded project on improving smoking cessation by addressing multiple health behaviors in people in Canada. PROSPERO CRD42017064430.

  20. Using remotely sensed data and stochastic models to simulate realistic flood hazard footprints across the continental US

    Science.gov (United States)

    Bates, P. D.; Quinn, N.; Sampson, C. C.; Smith, A.; Wing, O.; Neal, J. C.

    2017-12-01

    Remotely sensed data has transformed the field of large scale hydraulic modelling. New digital elevation, hydrography and river width data has allowed such models to be created for the first time, and remotely sensed observations of water height, slope and water extent has allowed them to be calibrated and tested. As a result, we are now able to conduct flood risk analyses at national, continental or even global scales. However, continental scale analyses have significant additional complexity compared to typical flood risk modelling approaches. Traditional flood risk assessment uses frequency curves to define the magnitude of extreme flows at gauging stations. The flow values for given design events, such as the 1 in 100 year return period flow, are then used to drive hydraulic models in order to produce maps of flood hazard. Such an approach works well for single gauge locations and local models because over relatively short river reaches (say 10-60km) one can assume that the return period of an event does not vary. At regional to national scales and across multiple river catchments this assumption breaks down, and for a given flood event the return period will be different at different gauging stations, a pattern known as the event `footprint'. Despite this, many national scale risk analyses still use `constant in space' return period hazard layers (e.g. the FEMA Special Flood Hazard Areas) in their calculations. Such an approach can estimate potential exposure, but will over-estimate risk and cannot determine likely flood losses over a whole region or country. We address this problem by using a stochastic model to simulate many realistic extreme event footprints based on observed gauged flows and the statistics of gauge to gauge correlations. We take the entire USGS gauge data catalogue for sites with > 45 years of record and use a conditional approach for multivariate extreme values to generate sets of flood events with realistic return period variation in

  1. Monitoring and evaluation of disaster response efforts undertaken by local health departments: a rapid realist review.

    Science.gov (United States)

    Gossip, Kate; Gouda, Hebe; Lee, Yong Yi; Firth, Sonja; Bermejo, Raoul; Zeck, Willibald; Jimenez Soto, Eliana

    2017-06-29

    Local health departments are often at the forefront of a disaster response, attending to the immediate trauma inflicted by the disaster and also the long term health consequences. As the frequency and severity of disasters are projected to rise, monitoring and evaluation (M&E) efforts are critical to help local health departments consolidate past experiences and improve future response efforts. Local health departments often conduct M&E work post disaster, however, many of these efforts fail to improve response procedures. We undertook a rapid realist review (RRR) to examine why M&E efforts undertaken by local health departments do not always result in improved disaster response efforts. We aimed to complement existing frameworks by focusing on the most basic and pragmatic steps of a M&E cycle targeted towards continuous system improvements. For these purposes, we developed a theoretical framework that draws on the quality improvement literature to 'frame' the steps in the M&E cycle. This framework encompassed a M&E cycle involving three stages (i.e., document and assess, disseminate and implement) that must be sequentially completed to learn from past experiences and improve future disaster response efforts. We used this framework to guide our examination of the literature and to identify any context-mechanism-outcome (CMO) configurations which describe how M&E may be constrained or enabled at each stage of the M&E cycle. This RRR found a number of explanatory CMO configurations that provide valuable insights into some of the considerations that should be made when using M&E to improve future disaster response efforts. Firstly, to support the accurate documentation and assessment of a disaster response, local health departments should consider how they can: establish a culture of learning within health departments; use embedded training methods; or facilitate external partnerships. Secondly, to enhance the widespread dissemination of lessons learned and facilitate

  2. A realist synthesis of social connectivity interventions during transition to parenthood: The value of relationships.

    Science.gov (United States)

    Bennett, Claudine T; Buchan, Judy L; Letourneau, Nicole; Shanker, Stuart G; Fenwick, Anne; Smith-Chant, Brenda; Gilmer, Cyndi

    2017-04-01

    Social connections are important during the transition to parenthood. A wide body of literature suggests that these connections enhance health and contribute to wellbeing. In the case of parents and families, social connections can influence child development. Nurses and public health agencies are in a unique position to advocate for resources and approaches to enhance social connectivity for parents during this important life transition. The aim of this review was to identify the universal social connectivity interventions that work, and the conditions that foster social connections for parents and enhance child development. The review was undertaken as part of a larger research project to inform the question: What are the population-level interventions that public health can implement to promote social, emotional and cognitive development from the prenatal period to the end of the first year of life? Social connectivity is one of three domains that were explored in the full study. Realist synthesis. Medline, CINAHL, ERIC, SocAbs, PsychINFO, grey literature. A literature search was conducted using relevant key words and MeSH headings. Nearly 2000 papers were reviewed by title and sorted based on inclusion and exclusion criteria. Data extraction aided quality appraisal and analysis and informed the development of an explanatory mechanism. Twenty-seven papers were included in the synthesis, with findings described in four theme areas: (a) connections in the community, (b) internet connections, (c) prenatal connections, and (d) connections for fathers. The literature available to answer the research question is scant and of varying quality. Community development, family-systems intervention practices, principles of father inclusive practice and group prenatal care models have been demonstrated to foster social connectivity for parents. Online social networking provides valuable informational support. Changing social structures and technology have influenced the way

  3. Understanding the impact of visual arts interventions for people living with dementia: a realist review protocol.

    Science.gov (United States)

    Windle, Gill; Gregory, Samantha; Newman, Andrew; Goulding, Anna; O'Brien, Dave; Parkinson, Clive

    2014-08-15

    Arts-based activities are being increasingly suggested as a valuable activity for people living with dementia in terms of countering the negative aspects of their condition. The potential for such programmes to improve a broad range of psychosocial outcomes is suggested in some studies. However, there is largely an absence of rigorous methodology to demonstrate the benefits, and research results are mixed. Practice variability in terms of the content, contexts and implementation of such interventions raises challenges in terms of identifying an optimal arts programme model that could be adopted by other service providers. Understanding how interventions may have the best chance at broad implementation success and uptake is limited. A realist review will be undertaken. This aims to understand how visual arts interventions influence outcomes in people living with dementia. The review will explore how the context, that is the circumstances which enable or constrain, affect outcomes through the activation of mechanisms. An early scoping search and a stakeholder survey formulated the preliminary programme theory. A systematic literature search across a broad range of disciplines (arts, humanities, social sciences, health) will be undertaken to identify journal articles and grey literature. Data will be extracted in relation to the programme theory, contextual factors, mechanisms and outcomes and their configurations, background information about the study design and participant characteristics, detail about the quantity ('dose') of an intervention, theoretical perspectives proposed by the authors of the paper and further theorising by the reviewer. Thematic connections/patterns will be sought across the extracted data, identifying patterns amongst contextual factors, the mechanisms they trigger and the associated outcomes. Along with stakeholder engagement and validation, this review will help inform the development of an optimal, replicable arts intervention for people

  4. Comparison of pulsed versus continuous oxygen delivery using realistic adult nasal airway replicas

    Directory of Open Access Journals (Sweden)

    Chen JZ

    2017-08-01

    Full Text Available John Z Chen,1 Ira M Katz,2 Marine Pichelin,2 Kaixian Zhu,3 Georges Caillibotte,2 Michelle L Noga,4 Warren H Finlay,1 Andrew R Martin1 1Department of Mechanical Engineering, University of Alberta, Edmonton, AB, Canada; 2Medical R&D, Air Liquide Santé International, Centre de Recherche Paris-Saclay, Les Loges-en-Josas, 3Centre Explor!, Air Liquide Healthcare, Gentilly, France; 4Radiology and Diagnostic Imaging, University of Alberta, Edmonton, AB, Canada Background: Portable oxygen concentrators (POCs typically include pulse flow (PF modes to conserve oxygen. The primary aims of this study were to develop a predictive in vitro model for inhaled oxygen delivery using a set of realistic airway replicas, and to compare PF for a commercial POC with steady flow (SF from a compressed oxygen cylinder. Methods: Experiments were carried out using a stationary compressed oxygen cylinder, a POC, and 15 adult nasal airway replicas based on airway geometries derived from medical images. Oxygen delivery via nasal cannula was tested at PF settings of 2.0 and 6.0, and SF rates of 2.0 and 6.0 L/min. A test lung simulated three breathing patterns representative of a chronic obstructive pulmonary disease patient at rest, during exercise, and while asleep. Volume-averaged fraction of inhaled oxygen (FiO2 was calculated by analyzing oxygen concentrations sampled at the exit of each replica and inhalation flow rates over time. POC pulse volumes were also measured using a commercial O2 conserver test system to attempt to predict FiO2 for PF. Results: Relative volume-averaged FiO2 using PF ranged from 68% to 94% of SF values, increasing with breathing frequency and tidal volume. Three of 15 replicas failed to trigger the POC when used with the sleep breathing pattern at the 2.0 setting, and four of 15 replicas failed to trigger at the 6.0 setting. FiO2 values estimated from POC pulse characteristics followed similar trends but were lower than those derived from

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

    NARCIS (Netherlands)

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

    In times of economic downturn, perceived realistic intergroup threats (e.g., labour competition) often dominate political and media discourse. Although local outgroups (e.g., local immigrants) can be experienced as sources of realistic threats, we propose that such threats can also be perceived to

  6. 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…

  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. Realist identification of group-level latent variables for perinatal social epidemiology theory building.

    Science.gov (United States)

    Eastwood, John Graeme; Jalaludin, Bin Badrudin; Kemp, Lynn Ann; Phung, Hai Ngoc

    2014-01-01

    We have previously reported in this journal on an ecological study of perinatal depressive symptoms in South Western Sydney. In that article, we briefly reported on a factor analysis that was utilized to identify empirical indicators for analysis. In this article, we report on the mixed method approach that was used to identify those latent variables. Social epidemiology has been slow to embrace a latent variable approach to the study of social, political, economic, and cultural structures and mechanisms, partly for philosophical reasons. Critical realist ontology and epistemology have been advocated as an appropriate methodological approach to both theory building and theory testing in the health sciences. We describe here an emergent mixed method approach that uses qualitative methods to identify latent constructs followed by factor analysis using empirical indicators chosen to measure identified qualitative codes. Comparative analysis of the findings is reported together with a limited description of realist approaches to abstract reasoning.

  9. Realistic Gamow shell model for resonance and continuum in atomic nuclei

    Science.gov (United States)

    Xu, F. R.; Sun, Z. H.; Wu, Q.; Hu, B. S.; Dai, S. J.

    2018-02-01

    The Gamow shell model can describe resonance and continuum for atomic nuclei. The model is established in the complex-moment (complex-k) plane of the Berggren coordinates in which bound, resonant and continuum states are treated on equal footing self-consistently. In the present work, the realistic nuclear force, CD Bonn, has been used. We have developed the full \\hat{Q}-box folded-diagram method to derive the realistic effective interaction in the model space which is nondegenerate and contains resonance and continuum channels. The CD-Bonn potential is renormalized using the V low-k method. With choosing 16O as the inert core, we have applied the Gamow shell model to oxygen isotopes.

  10. Analysis of a realistic and idealized dispersion compensating photonic crystal fiber Raman Amplifier

    DEFF Research Database (Denmark)

    Varshney, S.K.; Saitoh, K.; Koshiba, M.

    2007-01-01

    In the present paper, the highly efficient Raman amplification properties of a realistic and idealized dispersion compensating photonic crystal fiber (DCPCF) are described numerically. We have used an accurate full-vectorial finite element modal solver with hybrid curvilinear edge/nodal elements...... and anisotropic perfectly matched layers for an accurate modal characterization of the realistic as well as idealized DCPCF. A good agreement is observed between numerically evaluated and experimentally [P.J. Roberts, B.J. Mangan, H. Sabert, F. Couny, et al., J. Opt. Fiber Commun. Rep. 2 (2005) 435-461] measured...... dispersion values. A high peak Raman gain efficiency of 10.5 W-¹?km-¹ is obtained at 13.1 THz frequency shift for a 1455 nm depolarized pump. A DCPCF module of 1-km length can compensate for the dispersion accumulated over 70-km of conventional single mode fiber link with a residual dispersion of +/-50 ps...

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

    International Nuclear Information System (INIS)

    Vary, J.P.

    1978-01-01

    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 132 Sn region are described. Then results are shown for the ground-state properties of 132 Sn as calculated from the density-dependent Hartree-Fock approach with the Skyrme Hamiltonian. A single theoretical Hamiltonian for all nuclei from doubly magic 132 Sn to doubly magic 208 Pb 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 136 Xe. 10 figures

  12. Designing Rehabilitation and Reintegration Programmes for Violent Extremist Offenders: A Realist Approach

    Directory of Open Access Journals (Sweden)

    Tinka Veldhuis

    2012-03-01

    Full Text Available In this Research Paper, Research Fellow Dr. Tinka Veldhuis makes an argument for a Realist approach to rehabilitation and reintegration programmes for inmates with a terrorist or extremist background. Accordingly, within the Realist framework, it is stressed that the outcomes of rehabilitation programmes should be understood as a product of the policy mechanisms and the context in which they are implemented. To maximise the likelihood of success it is important to make explicit the underlying assumptions about how the intervention should, given the unique context, contribute to achieving its objectives. This paper endeavours to highlight some of the key questions that need to be answered before and during the implementation of rehabilitation policies.

  13. Social Means Do Not Justify Corruptible Ends: A Realist Perspective of Social Innovation and Design

    Directory of Open Access Journals (Sweden)

    Otto von Busch

    Full Text Available This article introduces designers to the dilemma that arises when twin aspects of social innovation—social means and social ends—do not align. Some academics have noted the anti-social, anti-political, and anti-inventive effects emerging from the spread of microfinance practices. We discuss the tendency for social design and innovation literature to focus on design processes rather than outcomes, and introduce ideas from realist political theory to account for the corruptibility of social innovations. We suggest that designers can prevent the corruption of social outcomes by shifting from idealist “what if” scenarios to realist “who whom?” questions instead.

  14. A hyper-realistic method for facial approximation: the case of the Italian humanist Angelo Poliziano.

    Science.gov (United States)

    Milani, Chantal; Capussotto, Valter; Guaschino, Michele; Mombello, Domenico; Cocuzza, Matteo; Pirri, Candido Fabrizio; Panattoni, Gian Luigi; Lambiase, Simonetta; Gruppioni, Giorgio

    2015-01-01

    Frequently, identification of individuals is problematical due to the level of associated decomposition and even more when the skeletal remains are incomplete or fragmented. The identikit, which includes a sketch or a facial reconstruction, could assist investigators with determining the identity of the decedent. Similarly, in archeology and physical anthropology it gives a realistic appearance to a historical character known only through iconography. We examined the skull of Angelo Poliziano, an Italian humanist of the 15(th) century. Previously, his facial approximation was completed in clay according to the Manchester protocol and then a duplication was prepared in ultra-realistic materials. This technique returns a long lasting 3D model of the individual and provides the perception to be in front of a real person and, although expensive, applied in forensic context could it improve the recognition of the individual.

  15. Data processing path from multimodal 3D measurement to realistic virtual model

    Science.gov (United States)

    Sitnik, Robert; Krzeslowski, Jakub; Mączkowski, Grzegorz

    2011-03-01

    A set of calculation methods has been developed and tested to provide means of creating virtual copies of three dimensional (3D) historical objects with minimal user input. We present a step by step data processing path along with algorithm description required to reconstruct a realistic 3D model of a culturally significant object. The important feature for archiving historical objects is the ability to include both information about its shape and texture, allowing visualization using arbitrary conditions of illumination. Data samples used as input for the processing method chain were collected using an integrated device consisting of shape, multispectral color and simplified BRDF measurements. To confirm the usability of presented methods, it has been tested by example of real life object - statue of an ancient Greek goddess Kybele. Additional visualization methods have also been examined to render a realistic virtual representation satisfying intrinsic surface properties of the investigated specimen.

  16. 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”.

  17. 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...

  18. Substituting physicians with nurse practitioners, physician assistants or nurses in nursing homes: protocol for a realist evaluation case study.

    Science.gov (United States)

    Lovink, Marleen Hermien; Persoon, Anke; van Vught, Anneke J A H; Schoonhoven, Lisette; Koopmans, Raymond T C M; Laurant, Miranda G H

    2017-06-08

    In developed countries, substituting physicians with nurse practitioners, physician assistants and nurses (physician substitution) occurs in nursing homes as an answer to the challenges related to the ageing population and the shortage of staff, as well as to guarantee the quality of nursing home care. However, there is great diversity in how physician substitution in nursing homes is modelled and it is unknown how it can best contribute to the quality of healthcare. This study aims to gain insight into how physician substitution is modelled and whether it contributes to perceived quality of healthcare. Second, this study aims to provide insight into the elements of physician substitution that contribute to quality of healthcare. This study will use a multiple-case study design that draws upon realist evaluation principles. The realist evaluation is based on four concepts for explaining and understanding interventions: context, mechanism, outcome and context-mechanism-outcome configuration. The following steps will be taken: (1) developing a theory, (2) conducting seven case studies, (3) analysing outcome patterns after each case and a cross-case analysis at the end and (4) revising the initial theory. The research ethics committee of the region Arnhem Nijmegen in the Netherlands concluded that this study does not fall within the scope of the Dutch Medical Research Involving Human Subjects Act (WMO) (registration number 2015/1914). Before the start of the study, the Board of Directors of the nursing home organisations will be informed verbally and by letter and will also be asked for informed consent. In addition, all participants will be informed verbally and by letter and will be asked for informed consent. Findings will be disseminated by publication in a peer-reviewed journal, international and national conferences, national professional associations and policy partners in national government. © Article author(s) (or their employer(s) unless otherwise stated

  19. Rapid realist review of the evidence: achieving lasting change when mental health rehabilitation staff undertake recovery-oriented training.

    Science.gov (United States)

    Gee, Melanie; Bhanbhro, Sadiq; Cook, Sarah; Killaspy, Helen

    2017-08-01

    The aim of this study was to identify the factors contributing to lasting change in practice following a recovery-based training intervention for inpatient mental health rehabilitation staff. Staff training may help nurses and other staff groups in inpatient mental health rehabilitative settings to increase their recovery-oriented practice. There are no published reviews on the effectiveness of such training and few long-term evaluations. This review informed a realist evaluation of a specific intervention (GetREAL). Rapid realist review methodology was used to generate and prioritize programme theories. ASSIA, CINAHL, Cochrane Library, Medline, PsycINFO, Scopus, Web of Science and grey literature searches were performed in September 2014-March 2015 with no date restrictions. Stakeholders suggested further documents. GetREAL project documentation was consulted. Programme theory development took place iteratively with literature identification. Stakeholders validated and prioritized emerging programme theories and the prioritized theories were refined using literature case studies. Fifty-one relevant documents fed into 49 programme theories articulating seven mechanisms for lasting change. Prioritized mechanisms were: staff receptiveness to change; and staff feeling encouraged, motivated and supported by colleagues and management to change. Seven programme theories were prioritized and refined using data from four case studies. Lasting change can be facilitated by collaborative action planning, regular collaborative meetings, appointing a change agent, explicit management endorsement and prioritization and modifying organizational structures. Conversely, a challenging organizational climate, or a prevalence of 'change fatigue', may block change. Pre-intervention exploration may help identify any potential barriers to embedding recovery in the organizational culture. © 2016 John Wiley & Sons Ltd.

  20. 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