WorldWideScience

Sample records for simulated patient methods

  1. Sampling for Patient Exit Interviews: Assessment of Methods Using Mathematical Derivation and Computer Simulations.

    Science.gov (United States)

    Geldsetzer, Pascal; Fink, Günther; Vaikath, Maria; Bärnighausen, Till

    2018-02-01

    (1) To evaluate the operational efficiency of various sampling methods for patient exit interviews; (2) to discuss under what circumstances each method yields an unbiased sample; and (3) to propose a new, operationally efficient, and unbiased sampling method. Literature review, mathematical derivation, and Monte Carlo simulations. Our simulations show that in patient exit interviews it is most operationally efficient if the interviewer, after completing an interview, selects the next patient exiting the clinical consultation. We demonstrate mathematically that this method yields a biased sample: patients who spend a longer time with the clinician are overrepresented. This bias can be removed by selecting the next patient who enters, rather than exits, the consultation room. We show that this sampling method is operationally more efficient than alternative methods (systematic and simple random sampling) in most primary health care settings. Under the assumption that the order in which patients enter the consultation room is unrelated to the length of time spent with the clinician and the interviewer, selecting the next patient entering the consultation room tends to be the operationally most efficient unbiased sampling method for patient exit interviews. © 2016 The Authors. Health Services Research published by Wiley Periodicals, Inc. on behalf of Health Research and Educational Trust.

  2. Learning outcomes associated with patient simulation method in pharmacotherapy education: an integrative review.

    Science.gov (United States)

    Aura, Suvi M; Sormunen, Marjorita S T; Jordan, Sue E; Tossavainen, Kerttu A; Turunen, Hannele E

    2015-06-01

    The aims of this systematic integrative review were to identify evidence for the use of patient simulation teaching methods in pharmacotherapy education and to explore related learning outcomes. A systematic literature search was conducted using 6 databases as follows: CINAHL, PubMed, SCOPUS, ERIC, MEDIC, and the Cochrane Library, using the key words relating to patient simulation and pharmacotherapy. The methodological quality of each study was evaluated. Eighteen articles met the inclusion criteria. The earliest article was published in 2005. The selected research articles were subjected to qualitative content analysis. Patient simulation has been used in pharmacotherapy education for preregistration nursing, dental, medical, and pharmacy students and for the continuing education of nurses. Learning outcomes reported were summarized as follows: (1) commitment to pharmacotherapy learning, (2) development of pharmacotherapy evaluation skills, (3) improvement in pharmacotherapy application skills, and (4) knowledge and understanding of pharmacotherapy. To develop effective teaching methods and ensure health care professionals' competence in medication management, further research is needed to determine the educational and clinical effectiveness of simulation teaching methods.

  3. Assessing Critical Thinking Outcomes of Dental Hygiene Students Utilizing Virtual Patient Simulation: A Mixed Methods Study.

    Science.gov (United States)

    Allaire, Joanna L

    2015-09-01

    Dental hygiene educators must determine which educational practices best promote critical thinking, a quality necessary to translate knowledge into sound clinical decision making. The aim of this small pilot study was to determine whether virtual patient simulation had an effect on the critical thinking of dental hygiene students. A pretest-posttest design using the Health Science Reasoning Test was used to evaluate the critical thinking skills of senior dental hygiene students at The University of Texas School of Dentistry at Houston Dental Hygiene Program before and after their experience with computer-based patient simulation cases. Additional survey questions sought to identify the students' perceptions of whether the experience had helped develop their critical thinking skills and improved their ability to provide competent patient care. A convenience sample of 31 senior dental hygiene students completed both the pretest and posttest (81.5% of total students in that class); 30 senior dental hygiene students completed the survey on perceptions of the simulation (78.9% response rate). Although the results did not show a significant increase in mean scores, the students reported feeling that the use of virtual patients was an effective teaching method to promote critical thinking, problem-solving, and confidence in the clinical realm. The results of this pilot study may have implications to support the use of virtual patient simulations in dental hygiene education. Future research could include a larger controlled study to validate findings from this study.

  4. The role of simulation in mixed-methods research: a framework & application to patient safety.

    Science.gov (United States)

    Guise, Jeanne-Marie; Hansen, Matthew; Lambert, William; O'Brien, Kerth

    2017-05-04

    Research in patient safety is an important area of health services research and is a national priority. It is challenging to investigate rare occurrences, explore potential causes, and account for the complex, dynamic context of healthcare - yet all are required in patient safety research. Simulation technologies have become widely accepted as education and clinical tools, but have yet to become a standard tool for research. We developed a framework for research that integrates accepted patient safety models with mixed-methods research approaches and describe the performance of the framework in a working example of a large National Institutes of Health (NIH)-funded R01 investigation. This worked example of a framework in action, identifies the strengths and limitations of qualitative and quantitative research approaches commonly used in health services research. Each approach builds essential layers of knowledge. We describe how the use of simulation ties these layers of knowledge together and adds new and unique dimensions of knowledge. A mixed-methods research approach that includes simulation provides a broad multi-dimensional approach to health services and patient safety research.

  5. USU Patient Simulation Center

    Data.gov (United States)

    Federal Laboratory Consortium — he National Capital Area (NCA) Medical Simulation Center is a state-of-the-art training facility located near the main USU campus. It uses simulated patients (i.e.,...

  6. Evaluating medical student engagement during virtual patient simulations: a sequential, mixed methods study.

    Science.gov (United States)

    McCoy, Lise; Pettit, Robin K; Lewis, Joy H; Allgood, J Aaron; Bay, Curt; Schwartz, Frederic N

    2016-01-16

    Student engagement is an important domain for medical education, however, it is difficult to quantify. The goal of this study was to investigate the utility of virtual patient simulations (VPS) for increasing medical student engagement. Our aims were specifically to investigate how and to what extent the VPS foster student engagement. This study took place at A.T. Still University School of Osteopathic Medicine in Arizona (ATSU-SOMA), in the USA. First year medical students (n = 108) worked in teams to complete a series of four in-class virtual patient case studies. Student engagement was measured, defined as flow, interest, and relevance. These dimensions were measured using four data collection instruments: researcher observations, classroom photographs, tutor feedback, and an electronic exit survey. Qualitative data were analyzed using a grounded theory approach. Triangulation of findings between the four data sources indicate that VPS foster engagement in three facets: 1) Flow. In general, students enjoyed the activities, and were absorbed in the task at hand. 2) Interest. Students demonstrated interest in the activities, as evidenced by enjoyment, active discussion, and humor. Students remarked upon elements that caused cognitive dissonance: excessive text and classroom noise generated by multi-media and peer conversations. 3) Relevance. VPS were relevant, in terms of situational clinical practice, exam preparation, and obtaining concrete feedback on clinical decisions. Researchers successfully introduced a new learning platform into the medical school curriculum. The data collected during this study were also used to improve new learning modules and techniques associated with implementing them in the classroom. Results of this study assert that virtual patient simulations foster engagement in terms of flow, relevance, and interest.

  7. GEM simulation methods development

    International Nuclear Information System (INIS)

    Tikhonov, V.; Veenhof, R.

    2002-01-01

    A review of methods used in the simulation of processes in gas electron multipliers (GEMs) and in the accurate calculation of detector characteristics is presented. Such detector characteristics as effective gas gain, transparency, charge collection and losses have been calculated and optimized for a number of GEM geometries and compared with experiment. A method and a new special program for calculations of detector macro-characteristics such as signal response in a real detector readout structure, and spatial and time resolution of detectors have been developed and used for detector optimization. A detailed development of signal induction on readout electrodes and electronics characteristics are included in the new program. A method for the simulation of charging-up effects in GEM detectors is described. All methods show good agreement with experiment

  8. A Tissue Relevance and Meshing Method for Computing Patient-Specific Anatomical Models in Endoscopic Sinus Surgery Simulation

    Science.gov (United States)

    Audette, M. A.; Hertel, I.; Burgert, O.; Strauss, G.

    This paper presents on-going work on a method for determining which subvolumes of a patient-specific tissue map, extracted from CT data of the head, are relevant to simulating endoscopic sinus surgery of that individual, and for decomposing these relevant tissues into triangles and tetrahedra whose mesh size is well controlled. The overall goal is to limit the complexity of the real-time biomechanical interaction while ensuring the clinical relevance of the simulation. Relevant tissues are determined as the union of the pathology present in the patient, of critical tissues deemed to be near the intended surgical path or pathology, and of bone and soft tissue near the intended path, pathology or critical tissues. The processing of tissues, prior to meshing, is based on the Fast Marching method applied under various guises, in a conditional manner that is related to tissue classes. The meshing is based on an adaptation of a meshing method of ours, which combines the Marching Tetrahedra method and the discrete Simplex mesh surface model to produce a topologically faithful surface mesh with well controlled edge and face size as a first stage, and Almost-regular Tetrahedralization of the same prescribed mesh size as a last stage.

  9. Simulated settings; powerful arenas for learning patient safety practices and facilitating transference to clinical practice. A mixed method study.

    Science.gov (United States)

    Reime, Marit Hegg; Johnsgaard, Tone; Kvam, Fred Ivan; Aarflot, Morten; Breivik, Marit; Engeberg, Janecke Merethe; Brattebø, Guttorm

    2016-11-01

    Poor teamwork is an important factor in the occurrence of critical incidents because of a lack of non-technical skills. Team training can be a key to prevent these incidents. The purpose of this study was to explore the experience of nursing and medical students after a simulation-based interprofessional team training (SBITT) course and its impact on professional and patient safety practices, using a concurrent mixed-method design. The participants (n = 262) were organized into 44 interprofessional teams. The results showed that two training sequences the same day improved overall team performance. Making mistakes during SBITT appeared to improve the quality of patient care once the students returned to clinical practice as it made the students more vigilant. Furthermore, the video-assisted oral debriefing provided an opportunity to strengthen interprofessional teamwork and share situational awareness. SBITT gave the students an opportunity to practice clinical reasoning skills and to share professional knowledge. The students conveyed the importance of learning to speak up to ensure safe patient practices. Simulated settings seem to be powerful arenas for learning patient safety practices and facilitating transference of this awareness to clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Methods of channeling simulation

    International Nuclear Information System (INIS)

    Barrett, J.H.

    1989-06-01

    Many computer simulation programs have been used to interpret experiments almost since the first channeling measurements were made. Certain aspects of these programs are important in how accurately they simulate ions in crystals; among these are the manner in which the structure of the crystal is incorporated, how any quantity of interest is computed, what ion-atom potential is used, how deflections are computed from the potential, incorporation of thermal vibrations of the lattice atoms, correlations of thermal vibrations, and form of stopping power. Other aspects of the programs are included to improve the speed; among these are table lookup, importance sampling, and the multiparameter method. It is desirable for programs to facilitate incorporation of special features of interest in special situations; examples are relaxations and enhanced vibrations of surface atoms, easy substitution of an alternate potential for comparison, change of row directions from layer to layer in strained-layer lattices, and different vibration amplitudes for substitutional solute or impurity atoms. Ways of implementing all of these aspects and features and the consequences of them will be discussed. 30 refs., 3 figs

  11. New methods in plasma simulation

    International Nuclear Information System (INIS)

    Mason, R.J.

    1990-01-01

    The development of implicit methods of particle-in-cell (PIC) computer simulation in recent years, and their merger with older hybrid methods have created a new arsenal of simulation techniques for the treatment of complex practical problems in plasma physics. The new implicit hybrid codes are aimed at transitional problems that lie somewhere between the long time scale, high density regime associated with MHD modeling, and the short time scale, low density regime appropriate to PIC particle-in-cell techniques. This transitional regime arises in ICF coronal plasmas, in pulsed power plasma switches, in Z-pinches, and in foil implosions. Here, we outline how such a merger of implicit and hybrid methods has been carried out, specifically in the ANTHEM computer code, and demonstrate the utility of implicit hybrid simulation in applications. 25 refs., 5 figs

  12. A review and comparison of methods for recreating individual patient data from published Kaplan-Meier survival curves for economic evaluations: a simulation study.

    Science.gov (United States)

    Wan, Xiaomin; Peng, Liubao; Li, Yuanjian

    2015-01-01

    In general, the individual patient-level data (IPD) collected in clinical trials are not available to independent researchers to conduct economic evaluations; researchers only have access to published survival curves and summary statistics. Thus, methods that use published survival curves and summary statistics to reproduce statistics for economic evaluations are essential. Four methods have been identified: two traditional methods 1) least squares method, 2) graphical method; and two recently proposed methods by 3) Hoyle and Henley, 4) Guyot et al. The four methods were first individually reviewed and subsequently assessed regarding their abilities to estimate mean survival through a simulation study. A number of different scenarios were developed that comprised combinations of various sample sizes, censoring rates and parametric survival distributions. One thousand simulated survival datasets were generated for each scenario, and all methods were applied to actual IPD. The uncertainty in the estimate of mean survival time was also captured. All methods provided accurate estimates of the mean survival time when the sample size was 500 and a Weibull distribution was used. When the sample size was 100 and the Weibull distribution was used, the Guyot et al. method was almost as accurate as the Hoyle and Henley method; however, more biases were identified in the traditional methods. When a lognormal distribution was used, the Guyot et al. method generated noticeably less bias and a more accurate uncertainty compared with the Hoyle and Henley method. The traditional methods should not be preferred because of their remarkable overestimation. When the Weibull distribution was used for a fitted model, the Guyot et al. method was almost as accurate as the Hoyle and Henley method. However, if the lognormal distribution was used, the Guyot et al. method was less biased compared with the Hoyle and Henley method.

  13. Patient-specific surgical simulation.

    Science.gov (United States)

    Soler, Luc; Marescaux, Jacques

    2008-02-01

    Technological innovations of the twentieth century have provided medicine and surgery with new tools for education and therapy definition. Thus, by combining Medical Imaging and Virtual Reality, patient-specific applications providing preoperative surgical simulation have become possible.

  14. Improving patient safety through better teamwork: how effective are different methods of simulation debriefing? Protocol for a pragmatic, prospective and randomised study.

    Science.gov (United States)

    Freytag, Julia; Stroben, Fabian; Hautz, Wolf E; Eisenmann, Dorothea; Kämmer, Juliane E

    2017-06-30

    Medical errors have an incidence of 9% and may lead to worse patient outcome. Teamwork training has the capacity to significantly reduce medical errors and therefore improve patient outcome. One common framework for teamwork training is crisis resource management, adapted from aviation and usually trained in simulation settings. Debriefing after simulation is thought to be crucial to learning teamwork-related concepts and behaviours but it remains unclear how best to debrief these aspects. Furthermore, teamwork-training sessions and studies examining education effects on undergraduates are rare. The study aims to evaluate the effects of two teamwork-focused debriefings on team performance after an extensive medical student teamwork training. A prospective experimental study has been designed to compare a well-established three-phase debriefing method (gather-analyse-summarise; the GAS method ) to a newly developed and more structured debriefing approach that extends the GAS method with TeamTAG (teamwork techniques analysis grid). TeamTAG is a cognitive aid listing preselected teamwork principles and descriptions of behavioural anchors that serve as observable patterns of teamwork and is supposed to help structure teamwork-focused debriefing. Both debriefing methods will be tested during an emergency room teamwork-training simulation comprising six emergency medicine cases faced by 35 final-year medical students in teams of five. Teams will be randomised into the two debriefing conditions. Team performance during simulation and the number of principles discussed during debriefing will be evaluated. Learning opportunities, helpfulness and feasibility will be rated by participants and instructors. Analyses will include descriptive, inferential and explorative statistics. The study protocol was approved by the institutional office for data protection and the ethics committee of Charité Medical School Berlin and registered under EA2/172/16. All students will

  15. Perfusion vector - a new method to quantify myocardial perfusion scintigraphy images: a simulation study with validation in patients

    DEFF Research Database (Denmark)

    Minarik, David; Senneby, Martin; Wollmer, Per

    2015-01-01

    Background The interpretation of myocardial perfusion scintigraphy (MPS) largely relies on visual assessment by the physician of the localization and extent of a perfusion defect. The aim of this study was to introduce the concept of the perfusion vector as a new objective quantitative method...

  16. Validation of a new method for testing provider clinical quality in rural settings in low- and middle-income countries: the observed simulated patient.

    Directory of Open Access Journals (Sweden)

    Tin Aung

    Full Text Available BACKGROUND: Assessing the quality of care provided by individual health practitioners is critical to identifying possible risks to the health of the public. However, existing assessment methods can be inaccurate, expensive, or infeasible in many developing country settings, particularly in rural areas and especially for children. Following an assessment of the strengths and weaknesses of the existing methods for provider assessment, we developed a synthesis method combining components of direct observation, clinical vignettes, and medical mannequins which we have termed "Observed Simulated Patient" or OSP. An OSP assessment involves a trained actor playing the role of a 'mother', a life-size doll representing a 5-year old boy, and a trained observer. The provider being assessed was informed in advance of the role-playing, and told to conduct the diagnosis and treatment as he normally would while verbally describing the examinations. METHODOLOGY/PRINCIPAL FINDINGS: We tested the validity of OSP by conducting parallel scoring of medical providers in Myanmar, assessing the quality of their diagnosis and treatment of pediatric malaria, first by direct observation of true patients and second by OSP. Data were collected from 20 private independent medical practitioners in Mon and Kayin States, Myanmar between December 26, 2010 and January 12, 2011. All areas of assessment showed agreement between OSP and direct observation above 90% except for history taking related to past experience with malaria medicines. In this area, providers did not ask questions of the OSP to the same degree that they questioned real patients (agreement 82.8%. CONCLUSIONS/SIGNIFICANCE: The OSP methodology may provide a valuable option for quality assessment of providers in places, or for health conditions, where other assessment tools are unworkable.

  17. Methods for Monte Carlo simulations of biomacromolecules.

    Science.gov (United States)

    Vitalis, Andreas; Pappu, Rohit V

    2009-01-01

    The state-of-the-art for Monte Carlo (MC) simulations of biomacromolecules is reviewed. Available methodologies for sampling conformational equilibria and associations of biomacromolecules in the canonical ensemble, given a continuum description of the solvent environment, are reviewed. Detailed sections are provided dealing with the choice of degrees of freedom, the efficiencies of MC algorithms and algorithmic peculiarities, as well as the optimization of simple movesets. The issue of introducing correlations into elementary MC moves, and the applicability of such methods to simulations of biomacromolecules is discussed. A brief discussion of multicanonical methods and an overview of recent simulation work highlighting the potential of MC methods are also provided. It is argued that MC simulations, while underutilized biomacromolecular simulation community, hold promise for simulations of complex systems and phenomena that span multiple length scales, especially when used in conjunction with implicit solvation models or other coarse graining strategies.

  18. Numerical methods used in simulation

    International Nuclear Information System (INIS)

    Caseau, Paul; Perrin, Michel; Planchard, Jacques

    1978-01-01

    The fundamental numerical problem posed by simulation problems is the stability of the resolution diagram. The system of the most used equations is defined, since there is a family of models of increasing complexity with 3, 4 or 5 equations although only models with 3 and 4 equations have been used extensively. After defining what is meant by explicit or implicit, the best established stability results is given for one-dimension problems and then for two-dimension problems. It is shown that two types of discretisation may be defined: four and eight point diagrams (in one or two dimensions) and six and ten point diagrams (in one or two dimensions). To end, some results are given on problems that are not usually treated very much, i.e. non-asymptotic stability and the stability of diagrams based on finite elements [fr

  19. Methods for simulating turbulent phase screen

    International Nuclear Information System (INIS)

    Zhang Jianzhu; Zhang Feizhou; Wu Yi

    2012-01-01

    Some methods for simulating turbulent phase screen are summarized, and their characteristics are analyzed by calculating the phase structure function, decomposing phase screens into Zernike polynomials, and simulating laser propagation in the atmosphere. Through analyzing, it is found that, the turbulent high-frequency components are well contained by those phase screens simulated by the FFT method, but the low-frequency components are little contained. The low-frequency components are well contained by screens simulated by Zernike method, but the high-frequency components are not contained enough. The high frequency components contained will be improved by increasing the order of the Zernike polynomial, but they mainly lie in the edge-area. Compared with the two methods above, the fractal method is a better method to simulate turbulent phase screens. According to the radius of the focal spot and the variance of the focal spot jitter, there are limitations in the methods except the fractal method. Combining the FFT and Zernike method or combining the FFT method and self-similar theory to simulate turbulent phase screens is an effective and appropriate way. In general, the fractal method is probably the best way. (authors)

  20. Detector Simulation: Data Treatment and Analysis Methods

    CERN Document Server

    Apostolakis, J

    2011-01-01

    Detector Simulation in 'Data Treatment and Analysis Methods', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '4.1 Detector Simulation' of Chapter '4 Data Treatment and Analysis Methods' with the content: 4.1 Detector Simulation 4.1.1 Overview of simulation 4.1.1.1 Uses of detector simulation 4.1.2 Stages and types of simulation 4.1.2.1 Tools for event generation and detector simulation 4.1.2.2 Level of simulation and computation time 4.1.2.3 Radiation effects and background studies 4.1.3 Components of detector simulation 4.1.3.1 Geometry modeling 4.1.3.2 External fields 4.1.3.3 Intro...

  1. Isogeometric methods for numerical simulation

    CERN Document Server

    Bordas, Stéphane

    2015-01-01

    The book presents the state of the art in isogeometric modeling and shows how the method has advantaged. First an introduction to geometric modeling with NURBS and T-splines is given followed by the implementation into computer software. The implementation in both the FEM and BEM is discussed.

  2. Clinical simulation as an evaluation method in health informatics

    DEFF Research Database (Denmark)

    Jensen, Sanne

    2016-01-01

    Safe work processes and information systems are vital in health care. Methods for design of health IT focusing on patient safety are one of many initiatives trying to prevent adverse events. Possible patient safety hazards need to be investigated before health IT is integrated with local clinical...... work practice including other technology and organizational structure. Clinical simulation is ideal for proactive evaluation of new technology for clinical work practice. Clinical simulations involve real end-users as they simulate the use of technology in realistic environments performing realistic...... tasks. Clinical simulation study assesses effects on clinical workflow and enables identification and evaluation of patient safety hazards before implementation at a hospital. Clinical simulation also offers an opportunity to create a space in which healthcare professionals working in different...

  3. Spectral Methods in Numerical Plasma Simulation

    DEFF Research Database (Denmark)

    Coutsias, E.A.; Hansen, F.R.; Huld, T.

    1989-01-01

    An introduction is given to the use of spectral methods in numerical plasma simulation. As examples of the use of spectral methods, solutions to the two-dimensional Euler equations in both a simple, doubly periodic region, and on an annulus will be shown. In the first case, the solution is expanded...

  4. Evaluation of structural reliability using simulation methods

    Directory of Open Access Journals (Sweden)

    Baballëku Markel

    2015-01-01

    Full Text Available Eurocode describes the 'index of reliability' as a measure of structural reliability, related to the 'probability of failure'. This paper is focused on the assessment of this index for a reinforced concrete bridge pier. It is rare to explicitly use reliability concepts for design of structures, but the problems of structural engineering are better known through them. Some of the main methods for the estimation of the probability of failure are the exact analytical integration, numerical integration, approximate analytical methods and simulation methods. Monte Carlo Simulation is used in this paper, because it offers a very good tool for the estimation of probability in multivariate functions. Complicated probability and statistics problems are solved through computer aided simulations of a large number of tests. The procedures of structural reliability assessment for the bridge pier and the comparison with the partial factor method of the Eurocodes have been demonstrated in this paper.

  5. 2-d Simulations of Test Methods

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm

    2004-01-01

    One of the main obstacles for the further development of self-compacting concrete is to relate the fresh concrete properties to the form filling ability. Therefore, simulation of the form filling ability will provide a powerful tool in obtaining this goal. In this paper, a continuum mechanical...... approach is presented by showing initial results from 2-d simulations of the empirical test methods slump flow and L-box. This method assumes a homogeneous material, which is expected to correspond to particle suspensions e.g. concrete, when it remains stable. The simulations have been carried out when...... using both a Newton and Bingham model for characterisation of the rheological properties of the concrete. From the results, it is expected that both the slump flow and L-box can be simulated quite accurately when the model is extended to 3-d and the concrete is characterised according to the Bingham...

  6. Novel Methods for Electromagnetic Simulation and Design

    Science.gov (United States)

    2016-08-03

    modeling software that can handle complicated, electrically large objects in a manner that is sufficiently fast to allow design by simulation. 15. SUBJECT...electrically large objects in a manner that is sufficiently fast to allow design by simulation. We also developed new methods for scattering from cavities in a...basis for high fidelity modeling software that can handle complicated, electrically large objects in a manner that is sufficiently fast to allow

  7. Matrix method for acoustic levitation simulation.

    Science.gov (United States)

    Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

    2011-08-01

    A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort.

  8. The impact of repeated simulation on health and healthcare perceptions of simulated patients.

    NARCIS (Netherlands)

    Boerjan, M.; Boone, F.; Anthierens, S.; Weel-Baumgarten, E.M. van; Deveugele, M.

    2008-01-01

    OBJECTIVE: To explore the effect of simulating medical conditions on simulated patients (SPs). Main points of interest are influence on: perception of personal health and perception of their relation with the health care provider (HCP), personal well being. METHODS: Semi-structured interviews were

  9. Towards a personalised virtual diabetic patient simulator

    NARCIS (Netherlands)

    Maas, A.H.; Tani, G.; Pul, van C.; Beijerinck, H.C.W.; Cottaar, E.J.E.; Haak, H.R.; Riel, van N.A.W.

    2012-01-01

    The development of a diabetes simulator, an educational software tool which can help diabetic patients to better manage their disease, is described. Education of patients with diabetes mellitus is a fundamental part of diabetes care. One of the goals of diabetes education is to support the patients

  10. Standardised patient-simulated practice learning

    African Journals Online (AJOL)

    Teaching strategies must link theory to practice, foster critical thinking, be relevant and stimulate ... Standardised patient-simulated practice learning: A rich pedagogical .... relationship for them to grow and develop from novice to expert. They.

  11. Simulation teaching method in Engineering Optics

    Science.gov (United States)

    Lu, Qieni; Wang, Yi; Li, Hongbin

    2017-08-01

    We here introduce a pedagogical method of theoretical simulation as one major means of the teaching process of "Engineering Optics" in course quality improvement action plan (Qc) in our school. Students, in groups of three to five, complete simulations of interference, diffraction, electromagnetism and polarization of light; each student is evaluated and scored in light of his performance in the interviews between the teacher and the student, and each student can opt to be interviewed many times until he is satisfied with his score and learning. After three years of Qc practice, the remarkable teaching and learning effect is obatined. Such theoretical simulation experiment is a very valuable teaching method worthwhile for physical optics which is highly theoretical and abstruse. This teaching methodology works well in training students as to how to ask questions and how to solve problems, which can also stimulate their interest in research learning and their initiative to develop their self-confidence and sense of innovation.

  12. Hybrid Method Simulation of Slender Marine Structures

    DEFF Research Database (Denmark)

    Christiansen, Niels Hørbye

    This present thesis consists of an extended summary and five appended papers concerning various aspects of the implementation of a hybrid method which combines classical simulation methods and artificial neural networks. The thesis covers three main topics. Common for all these topics...... only recognize patterns similar to those comprised in the data used to train the network. Fatigue life evaluation of marine structures often considers simulations of more than a hundred different sea states. Hence, in order for this method to be useful, the training data must be arranged so...... that a single neural network can cover all relevant sea states. The applicability and performance of the present hybrid method is demonstrated on a numerical model of a mooring line attached to a floating offshore platform. The second part of the thesis demonstrates how sequential neural networks can be used...

  13. Haemodynamic imaging of thoracic stent-grafts by computational fluid dynamics (CFD): presentation of a patient-specific method combining magnetic resonance imaging and numerical simulations.

    Science.gov (United States)

    Midulla, Marco; Moreno, Ramiro; Baali, Adil; Chau, Ming; Negre-Salvayre, Anne; Nicoud, Franck; Pruvo, Jean-Pierre; Haulon, Stephan; Rousseau, Hervé

    2012-10-01

    In the last decade, there was been increasing interest in finding imaging techniques able to provide a functional vascular imaging of the thoracic aorta. The purpose of this paper is to present an imaging method combining magnetic resonance imaging (MRI) and computational fluid dynamics (CFD) to obtain a patient-specific haemodynamic analysis of patients treated by thoracic endovascular aortic repair (TEVAR). MRI was used to obtain boundary conditions. MR angiography (MRA) was followed by cardiac-gated cine sequences which covered the whole thoracic aorta. Phase contrast imaging provided the inlet and outlet profiles. A CFD mesh generator was used to model the arterial morphology, and wall movements were imposed according to the cine imaging. CFD runs were processed using the finite volume (FV) method assuming blood as a homogeneous Newtonian fluid. Twenty patients (14 men; mean age 62.2 years) with different aortic lesions were evaluated. Four-dimensional mapping of velocity and wall shear stress were obtained, depicting different patterns of flow (laminar, turbulent, stenosis-like) and local alterations of parietal stress in-stent and along the native aorta. A computational method using a combined approach with MRI appears feasible and seems promising to provide detailed functional analysis of thoracic aorta after stent-graft implantation. • Functional vascular imaging of the thoracic aorta offers new diagnostic opportunities • CFD can model vascular haemodynamics for clinical aortic problems • Combining CFD with MRI offers patient specific method of aortic analysis • Haemodynamic analysis of stent-grafts could improve clinical management and follow-up.

  14. A Simulation Method Measuring Psychomotor Nursing Skills.

    Science.gov (United States)

    McBride, Helena; And Others

    1981-01-01

    The development of a simulation technique to evaluate performance of psychomotor skills in an undergraduate nursing program is described. This method is used as one admission requirement to an alternate route nursing program. With modifications, any health profession could use this technique where psychomotor skills performance is important.…

  15. An Efficient Simulation Method for Rare Events

    KAUST Repository

    Rached, Nadhir B.

    2015-01-07

    Estimating the probability that a sum of random variables (RVs) exceeds a given threshold is a well-known challenging problem. Closed-form expressions for the sum distribution do not generally exist, which has led to an increasing interest in simulation approaches. A crude Monte Carlo (MC) simulation is the standard technique for the estimation of this type of probability. However, this approach is computationally expensive, especially when dealing with rare events. Variance reduction techniques are alternative approaches that can improve the computational efficiency of naive MC simulations. We propose an Importance Sampling (IS) simulation technique based on the well-known hazard rate twisting approach, that presents the advantage of being asymptotically optimal for any arbitrary RVs. The wide scope of applicability of the proposed method is mainly due to our particular way of selecting the twisting parameter. It is worth observing that this interesting feature is rarely satisfied by variance reduction algorithms whose performances were only proven under some restrictive assumptions. It comes along with a good efficiency, illustrated by some selected simulation results comparing the performance of our method with that of an algorithm based on a conditional MC technique.

  16. An Efficient Simulation Method for Rare Events

    KAUST Repository

    Rached, Nadhir B.; Benkhelifa, Fatma; Kammoun, Abla; Alouini, Mohamed-Slim; Tempone, Raul

    2015-01-01

    Estimating the probability that a sum of random variables (RVs) exceeds a given threshold is a well-known challenging problem. Closed-form expressions for the sum distribution do not generally exist, which has led to an increasing interest in simulation approaches. A crude Monte Carlo (MC) simulation is the standard technique for the estimation of this type of probability. However, this approach is computationally expensive, especially when dealing with rare events. Variance reduction techniques are alternative approaches that can improve the computational efficiency of naive MC simulations. We propose an Importance Sampling (IS) simulation technique based on the well-known hazard rate twisting approach, that presents the advantage of being asymptotically optimal for any arbitrary RVs. The wide scope of applicability of the proposed method is mainly due to our particular way of selecting the twisting parameter. It is worth observing that this interesting feature is rarely satisfied by variance reduction algorithms whose performances were only proven under some restrictive assumptions. It comes along with a good efficiency, illustrated by some selected simulation results comparing the performance of our method with that of an algorithm based on a conditional MC technique.

  17. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort

    International Nuclear Information System (INIS)

    Mah, Katherine; Danjoux, Cyril E.; Manship, Sharan; Makhani, Nadiya; Cardoso, Marlene; Sixel, Katharina E.

    1998-01-01

    Purpose: To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. Methods and Materials: A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Results: Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was <10 min in all cases. In the absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of ≥5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Conclusions: Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall

  18. Method of simulating dose reduction for digital radiographic systems

    International Nuclear Information System (INIS)

    Baath, M.; Haakansson, M.; Tingberg, A.; Maansson, L. G.

    2005-01-01

    The optimisation of image quality vs. radiation dose is an important task in medical imaging. To obtain maximum validity of the optimisation, it must be based on clinical images. Images at different dose levels can then either be obtained by collecting patient images at the different dose levels sought to investigate - including additional exposures and permission from an ethical committee - or by manipulating images to simulate different dose levels. The aim of the present work was to develop a method of simulating dose reduction for digital radiographic systems. The method uses information about the detective quantum efficiency and noise power spectrum at the original and simulated dose levels to create an image containing filtered noise. When added to the original image this results in an image with noise which, in terms of frequency content, agrees with the noise present in an image collected at the simulated dose level. To increase the validity, the method takes local dose variations in the original image into account. The method was tested on a computed radiography system and was shown to produce images with noise behaviour similar to that of images actually collected at the simulated dose levels. The method can, therefore, be used to modify an image collected at one dose level so that it simulates an image of the same object collected at any lower dose level. (authors)

  19. Simulation methods for nuclear production scheduling

    International Nuclear Information System (INIS)

    Miles, W.T.; Markel, L.C.

    1975-01-01

    Recent developments and applications of simulation methods for use in nuclear production scheduling and fuel management are reviewed. The unique characteristics of the nuclear fuel cycle as they relate to the overall optimization of a mixed nuclear-fossil system in both the short-and mid-range time frame are described. Emphasis is placed on the various formulations and approaches to the mid-range planning problem, whose objective is the determination of an optimal (least cost) system operation strategy over a multi-year planning horizon. The decomposition of the mid-range problem into power system simulation, reactor core simulation and nuclear fuel management optimization, and system integration models is discussed. Present utility practices, requirements, and research trends are described. 37 references

  20. Lagrangian numerical methods for ocean biogeochemical simulations

    Science.gov (United States)

    Paparella, Francesco; Popolizio, Marina

    2018-05-01

    We propose two closely-related Lagrangian numerical methods for the simulation of physical processes involving advection, reaction and diffusion. The methods are intended to be used in settings where the flow is nearly incompressible and the Péclet numbers are so high that resolving all the scales of motion is unfeasible. This is commonplace in ocean flows. Our methods consist in augmenting the method of characteristics, which is suitable for advection-reaction problems, with couplings among nearby particles, producing fluxes that mimic diffusion, or unresolved small-scale transport. The methods conserve mass, obey the maximum principle, and allow to tune the strength of the diffusive terms down to zero, while avoiding unwanted numerical dissipation effects.

  1. Simulation and the Monte Carlo method

    CERN Document Server

    Rubinstein, Reuven Y

    2016-01-01

    Simulation and the Monte Carlo Method, Third Edition reflects the latest developments in the field and presents a fully updated and comprehensive account of the major topics that have emerged in Monte Carlo simulation since the publication of the classic First Edition over more than a quarter of a century ago. While maintaining its accessible and intuitive approach, this revised edition features a wealth of up-to-date information that facilitates a deeper understanding of problem solving across a wide array of subject areas, such as engineering, statistics, computer science, mathematics, and the physical and life sciences. The book begins with a modernized introduction that addresses the basic concepts of probability, Markov processes, and convex optimization. Subsequent chapters discuss the dramatic changes that have occurred in the field of the Monte Carlo method, with coverage of many modern topics including: Markov Chain Monte Carlo, variance reduction techniques such as the transform likelihood ratio...

  2. Simulating colloid hydrodynamics with lattice Boltzmann methods

    International Nuclear Information System (INIS)

    Cates, M E; Stratford, K; Adhikari, R; Stansell, P; Desplat, J-C; Pagonabarraga, I; Wagner, A J

    2004-01-01

    We present a progress report on our work on lattice Boltzmann methods for colloidal suspensions. We focus on the treatment of colloidal particles in binary solvents and on the inclusion of thermal noise. For a benchmark problem of colloids sedimenting and becoming trapped by capillary forces at a horizontal interface between two fluids, we discuss the criteria for parameter selection, and address the inevitable compromise between computational resources and simulation accuracy

  3. An improved method for simulating radiographs

    International Nuclear Information System (INIS)

    Laguna, G.W.

    1986-01-01

    The parameters involved in generating actual radiographs and what can and cannot be modeled are examined in this report. Using the spectral distribution of the radiation source and the mass absorption curve for the material comprising the part to be modeled, the actual amount of radiation that would pass through the part and reach the film is determined. This method increases confidence in the results of the simulation and enables the modeling of parts made of multiple materials

  4. Spectral methods in numerical plasma simulation

    International Nuclear Information System (INIS)

    Coutsias, E.A.; Hansen, F.R.; Huld, T.; Knorr, G.; Lynov, J.P.

    1989-01-01

    An introduction is given to the use of spectral methods in numerical plasma simulation. As examples of the use of spectral methods, solutions to the two-dimensional Euler equations in both a simple, doubly periodic region, and on an annulus will be shown. In the first case, the solution is expanded in a two-dimensional Fourier series, while a Chebyshev-Fourier expansion is employed in the second case. A new, efficient algorithm for the solution of Poisson's equation on an annulus is introduced. Problems connected to aliasing and to short wavelength noise generated by gradient steepening are discussed. (orig.)

  5. Electromagnetic simulation using the FDTD method

    CERN Document Server

    Sullivan, Dennis M

    2013-01-01

    A straightforward, easy-to-read introduction to the finite-difference time-domain (FDTD) method Finite-difference time-domain (FDTD) is one of the primary computational electrodynamics modeling techniques available. Since it is a time-domain method, FDTD solutions can cover a wide frequency range with a single simulation run and treat nonlinear material properties in a natural way. Written in a tutorial fashion, starting with the simplest programs and guiding the reader up from one-dimensional to the more complex, three-dimensional programs, this book provides a simple, yet comp

  6. Comparison of classic simulation and virtual simulation in breast irradiation: prospective study on 14 patients

    International Nuclear Information System (INIS)

    Bauduceau, O.; Pons, P.; Romero, L.; Fayolle, M.; Campana, F.; Bollet, M.

    2005-01-01

    Purpose. - To compare conventional 2D simulation and virtual simulation on 14 patients with breast cancer. Patients and methods. - Patients were simulated for treatment using standard procedure. They subsequently underwent CT scan in the treatment position. The CTV was defined as breast tissue. The PTV was obtained by adding a 3D margin of 1 cm around CTV. Organs at risk (lungs and heart) were outlined. Ballistics and dose distribution obtained with the two planning methods were compared. Results. - With conventional simulation, 95% of CTV received 95% of the dose prescribed. Virtual simulation significantly improved dosimetric coverage of PTV without increasing irradiation volume of lung and heart. In 2D simulation, using three slices allowed optimisation by adjusting wedge angle. The five-slice plan was a much better predictor of the maximum dose regions when compared to the three-slice plan. Using entire CT data did not give any benefit. Conclusion. - Variations in CTV delineation and PTV definition limit interest of virtual simulation. In classic simulation, a 5 CT slice-plan can be used to optimise dose distribution. (author)

  7. Meshless Method for Simulation of Compressible Flow

    Science.gov (United States)

    Nabizadeh Shahrebabak, Ebrahim

    In the present age, rapid development in computing technology and high speed supercomputers has made numerical analysis and computational simulation more practical than ever before for large and complex cases. Numerical simulations have also become an essential means for analyzing the engineering problems and the cases that experimental analysis is not practical. There are so many sophisticated and accurate numerical schemes, which do these simulations. The finite difference method (FDM) has been used to solve differential equation systems for decades. Additional numerical methods based on finite volume and finite element techniques are widely used in solving problems with complex geometry. All of these methods are mesh-based techniques. Mesh generation is an essential preprocessing part to discretize the computation domain for these conventional methods. However, when dealing with mesh-based complex geometries these conventional mesh-based techniques can become troublesome, difficult to implement, and prone to inaccuracies. In this study, a more robust, yet simple numerical approach is used to simulate problems in an easier manner for even complex problem. The meshless, or meshfree, method is one such development that is becoming the focus of much research in the recent years. The biggest advantage of meshfree methods is to circumvent mesh generation. Many algorithms have now been developed to help make this method more popular and understandable for everyone. These algorithms have been employed over a wide range of problems in computational analysis with various levels of success. Since there is no connectivity between the nodes in this method, the challenge was considerable. The most fundamental issue is lack of conservation, which can be a source of unpredictable errors in the solution process. This problem is particularly evident in the presence of steep gradient regions and discontinuities, such as shocks that frequently occur in high speed compressible flow

  8. Visualization and simulation techniques for surgical simulators using actual patient's data.

    Science.gov (United States)

    Radetzky, Arne; Nürnberger, Andreas

    2002-11-01

    Because of the increasing complexity of surgical interventions research in surgical simulation became more and more important over the last years. However, the simulation of tissue deformation is still a challenging problem, mainly due to the short response times that are required for real-time interaction. The demands to hard and software are even larger if not only the modeled human anatomy is used but the anatomy of actual patients. This is required if the surgical simulator should be used as training medium for expert surgeons rather than students. In this article, suitable visualization and simulation methods for surgical simulation utilizing actual patient's datasets are described. Therefore, the advantages and disadvantages of direct and indirect volume rendering for the visualization are discussed and a neuro-fuzzy system is described, which can be used for the simulation of interactive tissue deformations. The neuro-fuzzy system makes it possible to define the deformation behavior based on a linguistic description of the tissue characteristics or to learn the dynamics by using measured data of real tissue. Furthermore, a simulator for minimally-invasive neurosurgical interventions is presented that utilizes the described visualization and simulation methods. The structure of the simulator is described in detail and the results of a system evaluation by an experienced neurosurgeon--a quantitative comparison between different methods of virtual endoscopy as well as a comparison between real brain images and virtual endoscopies--are given. The evaluation proved that the simulator provides a higher realism of the visualization and simulation then other currently available simulators. Copyright 2002 Elsevier Science B.V.

  9. Computerized simulation methods for dose reduction, in radiodiagnosis

    International Nuclear Information System (INIS)

    Brochi, M.A.C.

    1990-01-01

    The present work presents computational methods that allow the simulation of any situation encountered in diagnostic radiology. Parameters of radiographic techniques that yield a standard radiographic image, previously chosen, and so could compare the dose of radiation absorbed by the patient is studied. Initially the method was tested on a simple system composed of 5.0 cm of water and 1.0 mm of aluminium and, after verifying experimentally its validity, it was applied in breast and arm fracture radiographs. It was observed that the choice of the filter material is not an important factor, because analogous behaviours were presented by aluminum, iron, copper, gadolinium, and other filters. A method of comparison of materials based on the spectral match is shown. Both the results given by this simulation method and the experimental measurements indicate an equivalence of brass and copper, both more efficient than aluminium, in terms of exposition time, but not of dose. (author)

  10. A new method for simulating human emotions

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    How to make machines express emotions would be instrumental in establishing a completely new paradigm for man ma-chine interaction. A new method for simulating and assessing artificial psychology has been developed for the research of the emo-tion robot. The human psychology activity is regarded as a Markov process. An emotion space and psychology model is constructedbased on Markov process. The conception of emotion entropy is presented to assess the artificial emotion complexity. The simulatingresults play up to human psychology activity. This model can also be applied to consumer-friendly human-computer interfaces, andinteractive video etc.

  11. Comparison of validation methods for forming simulations

    Science.gov (United States)

    Schug, Alexander; Kapphan, Gabriel; Bardl, Georg; Hinterhölzl, Roland; Drechsler, Klaus

    2018-05-01

    The forming simulation of fibre reinforced thermoplastics could reduce the development time and improve the forming results. But to take advantage of the full potential of the simulations it has to be ensured that the predictions for material behaviour are correct. For that reason, a thorough validation of the material model has to be conducted after characterising the material. Relevant aspects for the validation of the simulation are for example the outer contour, the occurrence of defects and the fibre paths. To measure these features various methods are available. Most relevant and also most difficult to measure are the emerging fibre orientations. For that reason, the focus of this study was on measuring this feature. The aim was to give an overview of the properties of different measuring systems and select the most promising systems for a comparison survey. Selected were an optical, an eddy current and a computer-assisted tomography system with the focus on measuring the fibre orientations. Different formed 3D parts made of unidirectional glass fibre and carbon fibre reinforced thermoplastics were measured. Advantages and disadvantages of the tested systems were revealed. Optical measurement systems are easy to use, but are limited to the surface plies. With an eddy current system also lower plies can be measured, but it is only suitable for carbon fibres. Using a computer-assisted tomography system all plies can be measured, but the system is limited to small parts and challenging to evaluate.

  12. Hospital simulated patient programme: a guide.

    Science.gov (United States)

    Barrett, Jenny; Hodgson, Jan

    2011-12-01

    Many university courses employ simulated patients to work with students in the development of communication skills. Our challenge was to build a sustainable programme that could be adapted for medical, nursing and allied health staff, and groups of students, on our hospital campus. In recognition of the need to provide practice opportunities for junior medical staff to hone their capacity to communicate effectively with parents, we employed professional actors who are also qualified teachers. Junior doctors have multiple opportunities over their training time to work one-to-one with an actor-tutor in the role of simulated parent. The simulated parents are skilled in helping the trainees reflect on the conversation, and the trainees are given a recording of their sessions for further reflection and feedback from a colleague. This model has been adapted to meet the 'topic' needs and scheduling requirements of other staff and hospital-based student groups. In adapting the original medical staff programme, we came to appreciate not only the logistical but also the ethical considerations inherent in a simulated parent/patient programme. Our guide highlights the importance of safeguarding the educational integrity of the design, maintaining the fidelity of the simulations and ensuring the safety of all involved. © Blackwell Publishing Ltd 2011.

  13. Does simulation enhance nurses' ability to assess deteriorating patients?

    Science.gov (United States)

    Bliss, Maria; Aitken, Leanne M

    2018-01-01

    Recognising and responding to patient deterioration has been identified as a key skill in nursing care to ensure that care is escalated for prompt, efficient management of the potentially critically ill patient. Simulation is one teaching strategy that has been established in nurse education as a method for enhancing skills. The objective was to explore the experiences of registered nurses to ascertain whether they perceived that simulation enhanced their skills in recognising the deteriorating patient. An exploratory qualitative design was used. Data were collected from registered nurses using semi-structured interviews following a professional development course where scenario-based simulation had been used to assess the patient. Eight registered nurses were interviewed for this study. Semi-structured interviews were conducted face to face. Verbatim transcripts were analysed using thematic analysis to identify major themes. Four themes were identified: knowledge, improved assessment skills in caring for the acutely ill patient, the learning environment and decision making. The use of simulation as a strategy was perceived by nurses to improve their own ability in identifying deteriorating patients. The participants described how their knowledge was transferred to clinical practice, with the overall perception that this led to improved patient care. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Rare event simulation using Monte Carlo methods

    CERN Document Server

    Rubino, Gerardo

    2009-01-01

    In a probabilistic model, a rare event is an event with a very small probability of occurrence. The forecasting of rare events is a formidable task but is important in many areas. For instance a catastrophic failure in a transport system or in a nuclear power plant, the failure of an information processing system in a bank, or in the communication network of a group of banks, leading to financial losses. Being able to evaluate the probability of rare events is therefore a critical issue. Monte Carlo Methods, the simulation of corresponding models, are used to analyze rare events. This book sets out to present the mathematical tools available for the efficient simulation of rare events. Importance sampling and splitting are presented along with an exposition of how to apply these tools to a variety of fields ranging from performance and dependability evaluation of complex systems, typically in computer science or in telecommunications, to chemical reaction analysis in biology or particle transport in physics. ...

  15. Computational Simulations and the Scientific Method

    Science.gov (United States)

    Kleb, Bil; Wood, Bill

    2005-01-01

    As scientific simulation software becomes more complicated, the scientific-software implementor's need for component tests from new model developers becomes more crucial. The community's ability to follow the basic premise of the Scientific Method requires independently repeatable experiments, and model innovators are in the best position to create these test fixtures. Scientific software developers also need to quickly judge the value of the new model, i.e., its cost-to-benefit ratio in terms of gains provided by the new model and implementation risks such as cost, time, and quality. This paper asks two questions. The first is whether other scientific software developers would find published component tests useful, and the second is whether model innovators think publishing test fixtures is a feasible approach.

  16. Comparison Of Simulation Results When Using Two Different Methods For Mold Creation In Moldflow Simulation

    Directory of Open Access Journals (Sweden)

    Kaushikbhai C. Parmar

    2017-04-01

    Full Text Available Simulation gives different results when using different methods for the same simulation. Autodesk Moldflow Simulation software provide two different facilities for creating mold for the simulation of injection molding process. Mold can be created inside the Moldflow or it can be imported as CAD file. The aim of this paper is to study the difference in the simulation results like mold temperature part temperature deflection in different direction time for the simulation and coolant temperature for this two different methods.

  17. [Doctor-Patient Communication Training in Simulated Situations: Emotions and Perceptions of Simulated Patients during Patient-Centered Conversations].

    Science.gov (United States)

    Butollo, Maria Asisa; Holzinger, Anita; Wagner-Menghin, Michaela

    2018-04-13

    The use of simulated patients (SPs) for doctor-patient communication training has been established in medical curricula as an important didactic method. The study addresses the question, if patients' emotions and perceptions are represented adequately in patient-centered communication. 22 of 37 SPs of the Medical University of Vienna (12 women, 10 men) were asked openly about their feelings after having acted as an SP in a semi-structured interview, which employed the Critical Incident Technique. The interviews were recorded, transcribed, separated into situational analysis units und analyzed deductively; we used the evidence based qualities of patient-centered communication and the "Nationaler Kompetenzbasierter Lernzielkatalog Medizin" as a guideline. Out of 192 analysis units, 67 were evaluated as positive and 125 as negative. The SPs reported positive feelings, such as perceiving "stability and trust in relationships" (22%), perception of congruence (15%), acceptance (27%) and empathy (36%). As to negative feelings, SPs reported "perceiving instability" (18%), "incongruence" (11%), "lack of acceptance" (40%) and "lack of empathy" (30%). Additionally, 50% of SPs were positively affected when observing students' learning success. When SPs perceived patient-centered communication, they reported positive emotions. A lack of patient centeredness, on the contrary, provoked negative emotions. An empathic attitude, as well as a "lack of acceptance" with contrary effects had the strongest influence on the SPs' mental state. The reaction of SPs to patient centeredness is sufficiently authentic to reach learning objectives, however it is also affected by reactions of SPs to the learning success of students, which is irrelevant for the real-life doctor-patient interaction. SP reactions are affected by students' attitudes. Students should therefore be prepared well before interacting with SPs in a roleplay setting. While SPs' behavior is authentic in patient

  18. Same Content, Different Methods: Comparing Lecture, Engaged Classroom, and Simulation.

    Science.gov (United States)

    Raleigh, Meghan F; Wilson, Garland Anthony; Moss, David Alan; Reineke-Piper, Kristen A; Walden, Jeffrey; Fisher, Daniel J; Williams, Tracy; Alexander, Christienne; Niceler, Brock; Viera, Anthony J; Zakrajsek, Todd

    2018-02-01

    There is a push to use classroom technology and active teaching methods to replace didactic lectures as the most prevalent format for resident education. This multisite collaborative cohort study involving nine residency programs across the United States compared a standard slide-based didactic lecture, a facilitated group discussion via an engaged classroom, and a high-fidelity, hands-on simulation scenario for teaching the topic of acute dyspnea. The primary outcome was knowledge retention at 2 to 4 weeks. Each teaching method was assigned to three different residency programs in the collaborative according to local resources. Learning objectives were determined by faculty. Pre- and posttest questions were validated and utilized as a measurement of knowledge retention. Each site administered the pretest, taught the topic of acute dyspnea utilizing their assigned method, and administered a posttest 2 to 4 weeks later. Differences between the groups were compared using paired t-tests. A total of 146 residents completed the posttest, and scores increased from baseline across all groups. The average score increased 6% in the standard lecture group (n=47), 11% in the engaged classroom (n=53), and 9% in the simulation group (n=56). The differences in improvement between engaged classroom and simulation were not statistically significant. Compared to standard lecture, both engaged classroom and high-fidelity simulation were associated with a statistically significant improvement in knowledge retention. Knowledge retention after engaged classroom and high-fidelity simulation did not significantly differ. More research is necessary to determine if different teaching methods result in different levels of comfort and skill with actual patient care.

  19. Bio-imaging and visualization for patient-customized simulations

    CERN Document Server

    Luo, Xiongbiao; Li, Shuo

    2014-01-01

    This book contains the full papers presented at the MICCAI 2013 workshop Bio-Imaging and Visualization for Patient-Customized Simulations (MWBIVPCS 2013). MWBIVPCS 2013 brought together researchers representing several fields, such as Biomechanics, Engineering, Medicine, Mathematics, Physics and Statistic. The contributions included in this book present and discuss new trends in those fields, using several methods and techniques, including the finite element method, similarity metrics, optimization processes, graphs, hidden Markov models, sensor calibration, fuzzy logic, data mining, cellular automation, active shape models, template matching and level sets. These serve as tools to address more efficiently different and timely applications involving signal and image acquisition, image processing and analysis, image segmentation, image registration and fusion, computer simulation, image based modelling, simulation and surgical planning, image guided robot assisted surgical and image based diagnosis.  This boo...

  20. Airway skills training using a human patient simulator | Moodley ...

    African Journals Online (AJOL)

    ... of airway management skills using the simulator. Participant satisfaction was much better in the simulator group. The importance of psychomotor reinforcement should be borne in mind when designing simulation courses. Keywords: human patient simulator, simulation, airway management, psychomotor skills ...

  1. Mini Combat Trauma Patient Simulation System Defense Acquisition Challenge Program (DACP): Mini Combat Trauma Patient Simulation (Mini CTPS)

    National Research Council Canada - National Science Library

    2004-01-01

    .... It consists of networked realistic casualty generators, patient simulators and computer-based casualty simulations, virtual patients and equipment, data and sensor recorders, and an After- Action Review System...

  2. Numerical methods in simulation of resistance welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi

    2015-01-01

    Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...... thecontact area and the distribution of contact pressure. The numerical simulation of resistancewelding is illustrated by a spot welding example that includes subsequent tensile shear testing...

  3. Virtual Crowds Methods, Simulation, and Control

    CERN Document Server

    Pelechano, Nuria; Allbeck, Jan

    2008-01-01

    There are many applications of computer animation and simulation where it is necessary to model virtual crowds of autonomous agents. Some of these applications include site planning, education, entertainment, training, and human factors analysis for building evacuation. Other applications include simulations of scenarios where masses of people gather, flow, and disperse, such as transportation centers, sporting events, and concerts. Most crowd simulations include only basic locomotive behaviors possibly coupled with a few stochastic actions. Our goal in this survey is to establish a baseline o

  4. Implementation of full patient simulation training in surgical residency.

    Science.gov (United States)

    Fernandez, Gladys L; Lee, Patrick C; Page, David W; D'Amour, Elizabeth M; Wait, Richard B; Seymour, Neal E

    2010-01-01

    -measures analysis of variance and Wilcoxon rank sum tests. Residents participated in 4.5 ± 1.4 sessions per academic year. Compliance with scheduled training was 88%, 90%, and 99% over successive years. Performance data were available for 39 PGY1, 2, and 3 residents. Ten individual residents could be followed between PGY1 and PGY2. For these individuals, improvement in mean performance was detected for the PGY2 (81% ± 5% vs 86% ± 4%; p 2 standard deviations below mean for the PGY level and 5 of these had deficiencies in clinical performance noted by other evaluation methods. Patient simulation training was implemented successfully with good compliance in this medium-sized surgical residency training program, but clear challenges were encountered with issues related to the number and range of experiences available per resident, competition with other educational activities, and fidelity and realism. Initial experience suggests that the associated assessment methods can detect predictable improvements in patient management skills across successive residency years, as well as potentially deficient management. Additional work is required to determine the educational effect of this training on resident clinical competency. Copyright © 2010 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  5. Virtual simulation. First clinical results in patients with prostate cancer

    International Nuclear Information System (INIS)

    Buchali, A.; Dinges, S.; Koswig, S.; Rosenthal, P.; Salk, S.; Harder, C.; Schlenger, L.; Budach, V.

    1998-01-01

    Investigation of options of virtual simulation in patients with localized prostate cancer. Twenty-four patients suffering from prostate cancer were virtual simulated. The clinical target volume was contoured and the planning target volume was defined after CT scan. The isocenter of the planning target volume was determined and marked at patient's skin. The precision of patients marking was controlled with conventional simulation after physical radiation treatment planning. Mean differences of the patient's mark revealed between the 2 simulations in all room axes around 1 mm. The organs at risk were visualized in the digital reconstructed radiographs. The precise patient's mark of the isocentre by virtual simulation allows to skip the conventional simulation. The visualisation of organs at risk leeds to an unnecessarity of an application of contrast medium and to a further relieve of the patient. The personal requirement is not higher in virtual simulation than in conventional CT based radiation treatment planning. (orig./MG) [de

  6. Collaborative simulation method with spatiotemporal synchronization process control

    Science.gov (United States)

    Zou, Yisheng; Ding, Guofu; Zhang, Weihua; Zhang, Jian; Qin, Shengfeng; Tan, John Kian

    2016-10-01

    When designing a complex mechatronics system, such as high speed trains, it is relatively difficult to effectively simulate the entire system's dynamic behaviors because it involves multi-disciplinary subsystems. Currently,a most practical approach for multi-disciplinary simulation is interface based coupling simulation method, but it faces a twofold challenge: spatial and time unsynchronizations among multi-directional coupling simulation of subsystems. A new collaborative simulation method with spatiotemporal synchronization process control is proposed for coupling simulating a given complex mechatronics system across multiple subsystems on different platforms. The method consists of 1) a coupler-based coupling mechanisms to define the interfacing and interaction mechanisms among subsystems, and 2) a simulation process control algorithm to realize the coupling simulation in a spatiotemporal synchronized manner. The test results from a case study show that the proposed method 1) can certainly be used to simulate the sub-systems interactions under different simulation conditions in an engineering system, and 2) effectively supports multi-directional coupling simulation among multi-disciplinary subsystems. This method has been successfully applied in China high speed train design and development processes, demonstrating that it can be applied in a wide range of engineering systems design and simulation with improved efficiency and effectiveness.

  7. Math-Based Simulation Tools and Methods

    National Research Council Canada - National Science Library

    Arepally, Sudhakar

    2007-01-01

    .... The following methods are reviewed: matrix operations, ordinary and partial differential system of equations, Lagrangian operations, Fourier transforms, Taylor Series, Finite Difference Methods, implicit and explicit finite element...

  8. A method for ensemble wildland fire simulation

    Science.gov (United States)

    Mark A. Finney; Isaac C. Grenfell; Charles W. McHugh; Robert C. Seli; Diane Trethewey; Richard D. Stratton; Stuart Brittain

    2011-01-01

    An ensemble simulation system that accounts for uncertainty in long-range weather conditions and two-dimensional wildland fire spread is described. Fuel moisture is expressed based on the energy release component, a US fire danger rating index, and its variation throughout the fire season is modeled using time series analysis of historical weather data. This analysis...

  9. 'Odontologic dosimetric card' experiments and simulations using Monte Carlo methods

    International Nuclear Information System (INIS)

    Menezes, C.J.M.; Lima, R. de A.; Peixoto, J.E.; Vieira, J.W.

    2008-01-01

    The techniques for data processing, combined with the development of fast and more powerful computers, makes the Monte Carlo methods one of the most widely used tools in the radiation transport simulation. For applications in diagnostic radiology, this method generally uses anthropomorphic phantoms to evaluate the absorbed dose to patients during exposure. In this paper, some Monte Carlo techniques were used to simulation of a testing device designed for intra-oral X-ray equipment performance evaluation called Odontologic Dosimetric Card (CDO of 'Cartao Dosimetrico Odontologico' in Portuguese) for different thermoluminescent detectors. This paper used two computational models of exposition RXD/EGS4 and CDO/EGS4. In the first model, the simulation results are compared with experimental data obtained in the similar conditions. The second model, it presents the same characteristics of the testing device studied (CDO). For the irradiations, the X-ray spectra were generated by the IPEM report number 78, spectrum processor. The attenuated spectrum was obtained for IEC 61267 qualities and various additional filters for a Pantak 320 X-ray industrial equipment. The results obtained for the study of the copper filters used in the determination of the kVp were compared with experimental data, validating the model proposed for the characterization of the CDO. The results shower of the CDO will be utilized in quality assurance programs in order to guarantee that the equipment fulfill the requirements of the Norm SVS No. 453/98 MS (Brazil) 'Directives of Radiation Protection in Medical and Dental Radiodiagnostic'. We conclude that the EGS4 is a suitable code Monte Carlo to simulate thermoluminescent dosimeters and experimental procedures employed in the routine of the quality control laboratory in diagnostic radiology. (author)

  10. Interactive methods for exploring particle simulation data

    Energy Technology Data Exchange (ETDEWEB)

    Co, Christopher S.; Friedman, Alex; Grote, David P.; Vay, Jean-Luc; Bethel, E. Wes; Joy, Kenneth I.

    2004-05-01

    In this work, we visualize high-dimensional particle simulation data using a suite of scatter plot-based visualizations coupled with interactive selection tools. We use traditional 2D and 3D projection scatter plots as well as a novel oriented disk rendering style to convey various information about the data. Interactive selection tools allow physicists to manually classify ''interesting'' sets of particles that are highlighted across multiple, linked views of the data. The power of our application is the ability to correspond new visual representations of the simulation data with traditional, well understood visualizations. This approach supports the interactive exploration of the high-dimensional space while promoting discovery of new particle behavior.

  11. Hospital Registration Process Reengineering Using Simulation Method

    Directory of Open Access Journals (Sweden)

    Qiang Su

    2010-01-01

    Full Text Available With increasing competition, many healthcare organizations have undergone tremendous reform in the last decade aiming to increase efficiency, decrease waste, and reshape the way that care is delivered. This study focuses on the operational efficiency improvement of hospital’s registration process. The operational efficiency related factors including the service process, queue strategy, and queue parameters were explored systematically and illustrated with a case study. Guided by the principle of business process reengineering (BPR, a simulation approach was employed for process redesign and performance optimization. As a result, the queue strategy is changed from multiple queues and multiple servers to single queue and multiple servers with a prepare queue. Furthermore, through a series of simulation experiments, the length of the prepare queue and the corresponding registration process efficiency was quantitatively evaluated and optimized.

  12. Numerical simulation methods for electron and ion optics

    International Nuclear Information System (INIS)

    Munro, Eric

    2011-01-01

    This paper summarizes currently used techniques for simulation and computer-aided design in electron and ion beam optics. Topics covered include: field computation, methods for computing optical properties (including Paraxial Rays and Aberration Integrals, Differential Algebra and Direct Ray Tracing), simulation of Coulomb interactions, space charge effects in electron and ion sources, tolerancing, wave optical simulations and optimization. Simulation examples are presented for multipole aberration correctors, Wien filter monochromators, imaging energy filters, magnetic prisms, general curved axis systems and electron mirrors.

  13. Using a simulated patient to transfer patient-centred skills from simulated practice to real patients in practice

    Directory of Open Access Journals (Sweden)

    Yolinda Uys

    2014-11-01

    Conclusion: Using a simulated patient to teach administration of an intramuscular injection enhanced students’ patient-centredness when performing the procedure in practice. Recommendations include making use of a bigger sample and including a pre-test the next time research of this nature is carried out.

  14. Airway skills training using a human patient simulator

    African Journals Online (AJOL)

    Thesegan Moodley

    2016-04-11

    Apr 11, 2016 ... Airway management problems may be particularly challenging to junior doctors.1 ... They respond to real-time, real-life clinical ... Keywords: human patient simulator, simulation, airway management, psychomotor skills.

  15. Benchmarking HRA methods against different NPP simulator data

    International Nuclear Information System (INIS)

    Petkov, Gueorgui; Filipov, Kalin; Velev, Vladimir; Grigorov, Alexander; Popov, Dimiter; Lazarov, Lazar; Stoichev, Kosta

    2008-01-01

    The paper presents both international and Bulgarian experience in assessing HRA methods, underlying models approaches for their validation and verification by benchmarking HRA methods against different NPP simulator data. The organization, status, methodology and outlooks of the studies are described

  16. Math-Based Simulation Tools and Methods

    National Research Council Canada - National Science Library

    Arepally, Sudhakar

    2007-01-01

    ...: HMMWV 30-mph Rollover Test, Soldier Gear Effects, Occupant Performance in Blast Effects, Anthropomorphic Test Device, Human Models, Rigid Body Modeling, Finite Element Methods, Injury Criteria...

  17. Particle-transport simulation with the Monte Carlo method

    International Nuclear Information System (INIS)

    Carter, L.L.; Cashwell, E.D.

    1975-01-01

    Attention is focused on the application of the Monte Carlo method to particle transport problems, with emphasis on neutron and photon transport. Topics covered include sampling methods, mathematical prescriptions for simulating particle transport, mechanics of simulating particle transport, neutron transport, and photon transport. A literature survey of 204 references is included. (GMT)

  18. Real-time hybrid simulation using the convolution integral method

    International Nuclear Information System (INIS)

    Kim, Sung Jig; Christenson, Richard E; Wojtkiewicz, Steven F; Johnson, Erik A

    2011-01-01

    This paper proposes a real-time hybrid simulation method that will allow complex systems to be tested within the hybrid test framework by employing the convolution integral (CI) method. The proposed CI method is potentially transformative for real-time hybrid simulation. The CI method can allow real-time hybrid simulation to be conducted regardless of the size and complexity of the numerical model and for numerical stability to be ensured in the presence of high frequency responses in the simulation. This paper presents the general theory behind the proposed CI method and provides experimental verification of the proposed method by comparing the CI method to the current integration time-stepping (ITS) method. Real-time hybrid simulation is conducted in the Advanced Hazard Mitigation Laboratory at the University of Connecticut. A seismically excited two-story shear frame building with a magneto-rheological (MR) fluid damper is selected as the test structure to experimentally validate the proposed method. The building structure is numerically modeled and simulated, while the MR damper is physically tested. Real-time hybrid simulation using the proposed CI method is shown to provide accurate results

  19. Simulation of tunneling construction methods of the Cisumdawu toll road

    Science.gov (United States)

    Abduh, Muhamad; Sukardi, Sapto Nugroho; Ola, Muhammad Rusdian La; Ariesty, Anita; Wirahadikusumah, Reini D.

    2017-11-01

    Simulation can be used as a tool for planning and analysis of a construction method. Using simulation technique, a contractor could design optimally resources associated with a construction method and compare to other methods based on several criteria, such as productivity, waste, and cost. This paper discusses the use of simulation using Norwegian Method of Tunneling (NMT) for a 472-meter tunneling work in the Cisumdawu Toll Road project. Primary and secondary data were collected to provide useful information for simulation as well as problems that may be faced by the contractor. The method was modelled using the CYCLONE and then simulated using the WebCYCLONE. The simulation could show the duration of the project from the duration model of each work tasks which based on literature review, machine productivity, and several assumptions. The results of simulation could also show the total cost of the project that was modeled based on journal construction & building unit cost and online websites of local and international suppliers. The analysis of the advantages and disadvantages of the method was conducted based on its, wastes, and cost. The simulation concluded the total cost of this operation is about Rp. 900,437,004,599 and the total duration of the tunneling operation is 653 days. The results of the simulation will be used for a recommendation to the contractor before the implementation of the already selected tunneling operation.

  20. Interval sampling methods and measurement error: a computer simulation.

    Science.gov (United States)

    Wirth, Oliver; Slaven, James; Taylor, Matthew A

    2014-01-01

    A simulation study was conducted to provide a more thorough account of measurement error associated with interval sampling methods. A computer program simulated the application of momentary time sampling, partial-interval recording, and whole-interval recording methods on target events randomly distributed across an observation period. The simulation yielded measures of error for multiple combinations of observation period, interval duration, event duration, and cumulative event duration. The simulations were conducted up to 100 times to yield measures of error variability. Although the present simulation confirmed some previously reported characteristics of interval sampling methods, it also revealed many new findings that pertain to each method's inherent strengths and weaknesses. The analysis and resulting error tables can help guide the selection of the most appropriate sampling method for observation-based behavioral assessments. © Society for the Experimental Analysis of Behavior.

  1. The frontal method in hydrodynamics simulations

    Science.gov (United States)

    Walters, R.A.

    1980-01-01

    The frontal solution method has proven to be an effective means of solving the matrix equations resulting from the application of the finite element method to a variety of problems. In this study, several versions of the frontal method were compared in efficiency for several hydrodynamics problems. Three basic modifications were shown to be of value: 1. Elimination of equations with boundary conditions beforehand, 2. Modification of the pivoting procedures to allow dynamic management of the equation size, and 3. Storage of the eliminated equations in a vector. These modifications are sufficiently general to be applied to other classes of problems. ?? 1980.

  2. Multiple time-scale methods in particle simulations of plasmas

    International Nuclear Information System (INIS)

    Cohen, B.I.

    1985-01-01

    This paper surveys recent advances in the application of multiple time-scale methods to particle simulation of collective phenomena in plasmas. These methods dramatically improve the efficiency of simulating low-frequency kinetic behavior by allowing the use of a large timestep, while retaining accuracy. The numerical schemes surveyed provide selective damping of unwanted high-frequency waves and preserve numerical stability in a variety of physics models: electrostatic, magneto-inductive, Darwin and fully electromagnetic. The paper reviews hybrid simulation models, the implicitmoment-equation method, the direct implicit method, orbit averaging, and subcycling

  3. Natural tracer test simulation by stochastic particle tracking method

    International Nuclear Information System (INIS)

    Ackerer, P.; Mose, R.; Semra, K.

    1990-01-01

    Stochastic particle tracking methods are well adapted to 3D transport simulations where discretization requirements of other methods usually cannot be satisfied. They do need a very accurate approximation of the velocity field. The described code is based on the mixed hybrid finite element method (MHFEM) to calculated the piezometric and velocity field. The random-walk method is used to simulate mass transport. The main advantages of the MHFEM over FD or FE are the simultaneous calculation of pressure and velocity, which are considered as unknowns; the possibility of interpolating velocities everywhere; and the continuity of the normal component of the velocity vector from one element to another. For these reasons, the MHFEM is well adapted for particle tracking methods. After a general description of the numerical methods, the model is used to simulate the observations made during the Twin Lake Tracer Test in 1983. A good match is found between observed and simulated heads and concentrations. (Author) (12 refs., 4 figs.)

  4. Factorization method for simulating QCD at finite density

    International Nuclear Information System (INIS)

    Nishimura, Jun

    2003-01-01

    We propose a new method for simulating QCD at finite density. The method is based on a general factorization property of distribution functions of observables, and it is therefore applicable to any system with a complex action. The so-called overlap problem is completely eliminated by the use of constrained simulations. We test this method in a Random Matrix Theory for finite density QCD, where we are able to reproduce the exact results for the quark number density. (author)

  5. Intern as Patient: A Patient Experience Simulation to Cultivate Empathy in Emergency Medicine Residents

    Directory of Open Access Journals (Sweden)

    Sara W. Nelson

    2017-12-01

    Full Text Available Introduction Prior work links empathy and positive physician-patient relationships to improved healthcare outcomes. The objective of this study was to analyze a patient experience simulation for emergency medicine (EM interns as a way to teach empathy and conscientious patient care. Methods We conducted a qualitative descriptive study on an in situ, patient experience simulation held during EM residency orientation. Half the interns were patients brought into the emergency department (ED by ambulance and half were family members. Interns then took part in focus groups that discussed the experience. Data collected during these focus groups were coded by two investigators using a grounded theory approach and constant comparative methodology. Results We identified 10 major themes and 28 subthemes in the resulting qualitative data. Themes were in three broad categories: the experience as a patient or family member in the ED; application to current clinical practice; and evaluation of the exercise itself. Interns experienced firsthand the physical discomfort, emotional stress and confusion patients and families endure during the ED care process. They reflected on lessons learned, including the importance of good communication skills, frequent updates on care and timing, and being responsive to the needs and concerns of patients and families. All interns felt this was a valuable orientation experience. Conclusion Conducting a patient experience simulation may be a practical and effective way to develop empathy in EM resident physicians. Additional research evaluating the effect of participation in the simulation over a longer time period and assessing the effects on residents’ actual clinical care is warranted.

  6. Evaluation of full-scope simulator testing methods

    Energy Technology Data Exchange (ETDEWEB)

    Feher, M P; Moray, N; Senders, J W; Biron, K [Human Factors North Inc., Toronto, ON (Canada)

    1995-03-01

    This report discusses the use of full scope nuclear power plant simulators in licensing examinations for Unit First Operators of CANDU reactors. The existing literature is reviewed, and an annotated bibliography of the more important sources provided. Since existing methods are judged inadequate, conceptual bases for designing a system for licensing are discussed, and a method proposed which would make use of objective scoring methods based on data collection in full-scope simulators. A field trial of such a method is described. The practicality of such a method is critically discussed and possible advantages of subjective methods of evaluation considered. (author). 32 refs., 1 tab., 4 figs.

  7. Evaluation of full-scope simulator testing methods

    International Nuclear Information System (INIS)

    Feher, M.P.; Moray, N.; Senders, J.W.; Biron, K.

    1995-03-01

    This report discusses the use of full scope nuclear power plant simulators in licensing examinations for Unit First Operators of CANDU reactors. The existing literature is reviewed, and an annotated bibliography of the more important sources provided. Since existing methods are judged inadequate, conceptual bases for designing a system for licensing are discussed, and a method proposed which would make use of objective scoring methods based on data collection in full-scope simulators. A field trial of such a method is described. The practicality of such a method is critically discussed and possible advantages of subjective methods of evaluation considered. (author). 32 refs., 1 tab., 4 figs

  8. Constraint methods that accelerate free-energy simulations of biomolecules.

    Science.gov (United States)

    Perez, Alberto; MacCallum, Justin L; Coutsias, Evangelos A; Dill, Ken A

    2015-12-28

    Atomistic molecular dynamics simulations of biomolecules are critical for generating narratives about biological mechanisms. The power of atomistic simulations is that these are physics-based methods that satisfy Boltzmann's law, so they can be used to compute populations, dynamics, and mechanisms. But physical simulations are computationally intensive and do not scale well to the sizes of many important biomolecules. One way to speed up physical simulations is by coarse-graining the potential function. Another way is to harness structural knowledge, often by imposing spring-like restraints. But harnessing external knowledge in physical simulations is problematic because knowledge, data, or hunches have errors, noise, and combinatoric uncertainties. Here, we review recent principled methods for imposing restraints to speed up physics-based molecular simulations that promise to scale to larger biomolecules and motions.

  9. New method of fast simulation for a hadron calorimeter response

    International Nuclear Information System (INIS)

    Kul'chitskij, Yu.; Sutiak, J.; Tokar, S.; Zenis, T.

    2003-01-01

    In this work we present the new method of a fast Monte-Carlo simulation of a hadron calorimeter response. It is based on the three-dimensional parameterization of the hadronic shower obtained from the ATLAS TILECAL test beam data and GEANT simulations. A new approach of including the longitudinal fluctuations of hadronic shower is described. The obtained results of the fast simulation are in good agreement with the TILECAL experimental data

  10. Daylighting simulation: methods, algorithms, and resources

    Energy Technology Data Exchange (ETDEWEB)

    Carroll, William L.

    1999-12-01

    This document presents work conducted as part of Subtask C, ''Daylighting Design Tools'', Subgroup C2, ''New Daylight Algorithms'', of the IEA SHC Task 21 and the ECBCS Program Annex 29 ''Daylight in Buildings''. The search for and collection of daylighting analysis methods and algorithms led to two important observations. First, there is a wide range of needs for different types of methods to produce a complete analysis tool. These include: Geometry; Light modeling; Characterization of the natural illumination resource; Materials and components properties, representations; and Usability issues (interfaces, interoperability, representation of analysis results, etc). Second, very advantageously, there have been rapid advances in many basic methods in these areas, due to other forces. They are in part driven by: The commercial computer graphics community (commerce, entertainment); The lighting industry; Architectural rendering and visualization for projects; and Academia: Course materials, research. This has led to a very rich set of information resources that have direct applicability to the small daylighting analysis community. Furthermore, much of this information is in fact available online. Because much of the information about methods and algorithms is now online, an innovative reporting strategy was used: the core formats are electronic, and used to produce a printed form only secondarily. The electronic forms include both online WWW pages and a downloadable .PDF file with the same appearance and content. Both electronic forms include live primary and indirect links to actual information sources on the WWW. In most cases, little additional commentary is provided regarding the information links or citations that are provided. This in turn allows the report to be very concise. The links are expected speak for themselves. The report consists of only about 10+ pages, with about 100+ primary links, but

  11. Standardised patient-simulated practice learning: A rich ...

    African Journals Online (AJOL)

    This study investigates the use of standardised patients (SPs) in a simulated patient interview as a learning strategy to bridge the theory-practice gap. Simulation helps students to develop skills such as communication, higher cognitive thinking, decision-making and problem-solving. There is evidence to support the use of ...

  12. A Method for Functional Task Alignment Analysis of an Arthrocentesis Simulator.

    Science.gov (United States)

    Adams, Reid A; Gilbert, Gregory E; Buckley, Lisa A; Nino Fong, Rodolfo; Fuentealba, I Carmen; Little, Erika L

    2018-05-16

    During simulation-based education, simulators are subjected to procedures composed of a variety of tasks and processes. Simulators should functionally represent a patient in response to the physical action of these tasks. The aim of this work was to describe a method for determining whether a simulator does or does not have sufficient functional task alignment (FTA) to be used in a simulation. Potential performance checklist items were gathered from published arthrocentesis guidelines and aggregated into a performance checklist using Lawshe's method. An expert panel used this performance checklist and an FTA analysis questionnaire to evaluate a simulator's ability to respond to the physical actions required by the performance checklist. Thirteen items, from a pool of 39, were included on the performance checklist. Experts had mixed reviews of the simulator's FTA and its suitability for use in simulation. Unexpectedly, some positive FTA was found for several tasks where the simulator lacked functionality. By developing a detailed list of specific tasks required to complete a clinical procedure, and surveying experts on the simulator's response to those actions, educators can gain insight into the simulator's clinical accuracy and suitability. Unexpected of positive FTA ratings of function deficits suggest that further revision of the survey method is required.

  13. Construction of the real patient simulator system.

    Science.gov (United States)

    Chan, Richard; Sun, C T

    2012-05-01

    Simulation for perfusion education has been used for at least the past 25 years. The earlier models were either electronic (computer games) or fluid dynamic models and provided invaluable adjuncts to perfusion training and education. In 2009, the *North Shore-LIJ Health System at Great Neck, New York, opened an innovative "Bioskill Center" dedicated to simulated virtual reality advanced hands-on surgical training as well as perfusion simulation. Professional cardiac surgical organizations now show great interest in using simulation for training and recertification. Simulation will continue to be the direction for future perfusion training and education. This manuscript introduces a cost-effective system developed from discarded perfusion products and it is not intended to detail the actual lengthy process of its construction.

  14. A particle-based method for granular flow simulation

    KAUST Repository

    Chang, Yuanzhang; Bao, Kai; Zhu, Jian; Wu, Enhua

    2012-01-01

    We present a new particle-based method for granular flow simulation. In the method, a new elastic stress term, which is derived from a modified form of the Hooke's law, is included in the momentum governing equation to handle the friction of granular materials. Viscosity force is also added to simulate the dynamic friction for the purpose of smoothing the velocity field and further maintaining the simulation stability. Benefiting from the Lagrangian nature of the SPH method, large flow deformation can be well handled easily and naturally. In addition, a signed distance field is also employed to enforce the solid boundary condition. The experimental results show that the proposed method is effective and efficient for handling the flow of granular materials, and different kinds of granular behaviors can be well simulated by adjusting just one parameter. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg.

  15. Research on Monte Carlo simulation method of industry CT system

    International Nuclear Information System (INIS)

    Li Junli; Zeng Zhi; Qui Rui; Wu Zhen; Li Chunyan

    2010-01-01

    There are a series of radiation physical problems in the design and production of industry CT system (ICTS), including limit quality index analysis; the effect of scattering, efficiency of detectors and crosstalk to the system. Usually the Monte Carlo (MC) Method is applied to resolve these problems. Most of them are of little probability, so direct simulation is very difficult, and existing MC methods and programs can't meet the needs. To resolve these difficulties, particle flux point auto-important sampling (PFPAIS) is given on the basis of auto-important sampling. Then, on the basis of PFPAIS, a particular ICTS simulation method: MCCT is realized. Compared with existing MC methods, MCCT is proved to be able to simulate the ICTS more exactly and effectively. Furthermore, the effects of all kinds of disturbances of ICTS are simulated and analyzed by MCCT. To some extent, MCCT can guide the research of the radiation physical problems in ICTS. (author)

  16. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    vortex panel method to simulate potential flow in cascades is presented. The cascade ... The fluid loading on the blades, such as the normal force and pitching moment, may ... of such discrete infinite array singularities along the blade surface.

  17. A particle-based method for granular flow simulation

    KAUST Repository

    Chang, Yuanzhang

    2012-03-16

    We present a new particle-based method for granular flow simulation. In the method, a new elastic stress term, which is derived from a modified form of the Hooke\\'s law, is included in the momentum governing equation to handle the friction of granular materials. Viscosity force is also added to simulate the dynamic friction for the purpose of smoothing the velocity field and further maintaining the simulation stability. Benefiting from the Lagrangian nature of the SPH method, large flow deformation can be well handled easily and naturally. In addition, a signed distance field is also employed to enforce the solid boundary condition. The experimental results show that the proposed method is effective and efficient for handling the flow of granular materials, and different kinds of granular behaviors can be well simulated by adjusting just one parameter. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg.

  18. Comparing three methods for participatory simulation of hospital work systems

    DEFF Research Database (Denmark)

    Broberg, Ole; Andersen, Simone Nyholm

    Summative Statement: This study compared three participatory simulation methods using different simulation objects: Low resolution table-top setup using Lego figures, full scale mock-ups, and blueprints using Lego figures. It was concluded the three objects by differences in fidelity and affordance...... scenarios using the objects. Results: Full scale mock-ups significantly addressed the local space and technology/tool elements of a work system. In contrast, the table-top simulation object addressed the organizational issues of the future work system. The blueprint based simulation addressed...

  19. Fluid, solid and fluid-structure interaction simulations on patient-based abdominal aortic aneurysm models.

    Science.gov (United States)

    Kelly, Sinead; O'Rourke, Malachy

    2012-04-01

    This article describes the use of fluid, solid and fluid-structure interaction simulations on three patient-based abdominal aortic aneurysm geometries. All simulations were carried out using OpenFOAM, which uses the finite volume method to solve both fluid and solid equations. Initially a fluid-only simulation was carried out on a single patient-based geometry and results from this simulation were compared with experimental results. There was good qualitative and quantitative agreement between the experimental and numerical results, suggesting that OpenFOAM is capable of predicting the main features of unsteady flow through a complex patient-based abdominal aortic aneurysm geometry. The intraluminal thrombus and arterial wall were then included, and solid stress and fluid-structure interaction simulations were performed on this, and two other patient-based abdominal aortic aneurysm geometries. It was found that the solid stress simulations resulted in an under-estimation of the maximum stress by up to 5.9% when compared with the fluid-structure interaction simulations. In the fluid-structure interaction simulations, flow induced pressure within the aneurysm was found to be up to 4.8% higher than the value of peak systolic pressure imposed in the solid stress simulations, which is likely to be the cause of the variation in the stress results. In comparing the results from the initial fluid-only simulation with results from the fluid-structure interaction simulation on the same patient, it was found that wall shear stress values varied by up to 35% between the two simulation methods. It was concluded that solid stress simulations are adequate to predict the maximum stress in an aneurysm wall, while fluid-structure interaction simulations should be performed if accurate prediction of the fluid wall shear stress is necessary. Therefore, the decision to perform fluid-structure interaction simulations should be based on the particular variables of interest in a given

  20. Forest canopy BRDF simulation using Monte Carlo method

    NARCIS (Netherlands)

    Huang, J.; Wu, B.; Zeng, Y.; Tian, Y.

    2006-01-01

    Monte Carlo method is a random statistic method, which has been widely used to simulate the Bidirectional Reflectance Distribution Function (BRDF) of vegetation canopy in the field of visible remote sensing. The random process between photons and forest canopy was designed using Monte Carlo method.

  1. Simulation methods of nuclear electromagnetic pulse effects in integrated circuits

    International Nuclear Information System (INIS)

    Cheng Jili; Liu Yuan; En Yunfei; Fang Wenxiao; Wei Aixiang; Yang Yuanzhen

    2013-01-01

    In the paper the ways to compute the response of transmission line (TL) illuminated by electromagnetic pulse (EMP) were introduced firstly, which include finite-difference time-domain (FDTD) and trans-mission line matrix (TLM); then the feasibility of electromagnetic topology (EMT) in ICs nuclear electromagnetic pulse (NEMP) effect simulation was discussed; in the end, combined with the methods computing the response of TL, a new method of simulate the transmission line in IC illuminated by NEMP was put forward. (authors)

  2. An introduction to computer simulation methods applications to physical systems

    CERN Document Server

    Gould, Harvey; Christian, Wolfgang

    2007-01-01

    Now in its third edition, this book teaches physical concepts using computer simulations. The text incorporates object-oriented programming techniques and encourages readers to develop good programming habits in the context of doing physics. Designed for readers at all levels , An Introduction to Computer Simulation Methods uses Java, currently the most popular programming language. Introduction, Tools for Doing Simulations, Simulating Particle Motion, Oscillatory Systems, Few-Body Problems: The Motion of the Planets, The Chaotic Motion of Dynamical Systems, Random Processes, The Dynamics of Many Particle Systems, Normal Modes and Waves, Electrodynamics, Numerical and Monte Carlo Methods, Percolation, Fractals and Kinetic Growth Models, Complex Systems, Monte Carlo Simulations of Thermal Systems, Quantum Systems, Visualization and Rigid Body Dynamics, Seeing in Special and General Relativity, Epilogue: The Unity of Physics For all readers interested in developing programming habits in the context of doing phy...

  3. Motion simulation of hydraulic driven safety rod using FSI method

    International Nuclear Information System (INIS)

    Jung, Jaeho; Kim, Sanghaun; Yoo, Yeonsik; Cho, Yeonggarp; Kim, Jong In

    2013-01-01

    Hydraulic driven safety rod which is one of them is being developed by Division for Reactor Mechanical Engineering, KAERI. In this paper the motion of this rod is simulated by fluid structure interaction (FSI) method before manufacturing for design verification and pump sizing. A newly designed hydraulic driven safety rod which is one of reactivity control mechanism is simulated using FSI method for design verification and pump sizing. The simulation is done in CFD domain with UDF. The pressure drop is changed slightly by flow rates. It means that the pressure drop is mainly determined by weight of moving part. The simulated velocity of piston is linearly proportional to flow rates so the pump can be sized easily according to the rising and drop time requirement of the safety rod using the simulation results

  4. Simulated patient training: Using inter-rater reliability to evaluate simulated patient consistency in nursing education.

    Science.gov (United States)

    MacLean, Sharon; Geddes, Fiona; Kelly, Michelle; Della, Phillip

    2018-03-01

    Simulated patients (SPs) are frequently used for training nursing students in communication skills. An acknowledged benefit of using SPs is the opportunity to provide a standardized approach by which participants can demonstrate and develop communication skills. However, relatively little evidence is available on how to best facilitate and evaluate the reliability and accuracy of SPs' performances. The aim of this study is to investigate the effectiveness of an evidenced based SP training framework to ensure standardization of SPs. The training framework was employed to improve inter-rater reliability of SPs. A quasi-experimental study was employed to assess SP post-training understanding of simulation scenario parameters using inter-rater reliability agreement indices. Two phases of data collection took place. Initially a trial phase including audio-visual (AV) recordings of two undergraduate nursing students completing a simulation scenario is rated by eight SPs using the Interpersonal Communication Assessments Scale (ICAS) and Quality of Discharge Teaching Scale (QDTS). In phase 2, eight SP raters and four nursing faculty raters independently evaluated students' (N=42) communication practices using the QDTS. Intraclass correlation coefficients (ICC) were >0.80 for both stages of the study in clinical communication skills. The results support the premise that if trained appropriately, SPs have a high degree of reliability and validity to both facilitate and evaluate student performance in nurse education. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  5. A simulation method for lightning surge response of switching power

    International Nuclear Information System (INIS)

    Wei, Ming; Chen, Xiang

    2013-01-01

    In order to meet the need of protection design for lighting surge, a prediction method of lightning electromagnetic pulse (LEMP) response which is based on system identification is presented. Experiments of switching power's surge injection were conducted, and the input and output data were sampled, de-noised and de-trended. In addition, the model of energy coupling transfer function was obtained by system identification method. Simulation results show that the system identification method can predict the surge response of linear circuit well. The method proposed in the paper provided a convenient and effective technology for simulation of lightning effect.

  6. Methods of patient warming during abdominal surgery.

    Directory of Open Access Journals (Sweden)

    Li Shao

    Full Text Available BACKGROUND: Keeping abdominal surgery patients warm is common and warming methods are needed in power outages during natural disasters. We aimed to evaluate the efficacy of low-cost, low-power warming methods for maintaining normothermia in abdominal surgery patients. METHODS: Patients (n = 160 scheduled for elective abdominal surgery were included in this prospective clinical study. Five warming methods were applied: heated blood transfusion/fluid infusion vs. unheated; wrapping patients vs. not wrapping; applying moist dressings, heated or not; surgical field rinse heated or not; and applying heating blankets or not. Patients' nasopharyngeal and rectal temperatures were recorded to evaluate warming efficacy. Significant differences were found in mean temperatures of warmed patients compared to those not warmed. RESULTS: When we compared temperatures of abdominal surgery patient groups receiving three specific warming methods with temperatures of control groups not receiving these methods, significant differences were revealed in temperatures maintained during the surgeries between the warmed groups and controls. DISCUSSION: The value of maintaining normothermia in patients undergoing abdominal surgery under general anesthesia is accepted. Three effective economical and practically applicable warming methods are combined body wrapping and heating blanket; combined body wrapping, heated moist dressings, and heating blanket; combined body wrapping, heated moist dressings, and warmed surgical rinse fluid, with or without heating blanket. These methods are practically applicable when low-cost method is indeed needed.

  7. Real time simulation method for fast breeder reactors dynamics

    International Nuclear Information System (INIS)

    Miki, Tetsushi; Mineo, Yoshiyuki; Ogino, Takamichi; Kishida, Koji; Furuichi, Kenji.

    1985-01-01

    The development of multi-purpose real time simulator models with suitable plant dynamics was made; these models can be used not only in training operators but also in designing control systems, operation sequences and many other items which must be studied for the development of new type reactors. The prototype fast breeder reactor ''Monju'' is taken as an example. Analysis is made on various factors affecting the accuracy and computer load of its dynamic simulation. A method is presented which determines the optimum number of nodes in distributed systems and time steps. The oscillations due to the numerical instability are observed in the dynamic simulation of evaporators with a small number of nodes, and a method to cancel these oscillations is proposed. It has been verified through the development of plant dynamics simulation codes that these methods can provide efficient real time dynamics models of fast breeder reactors. (author)

  8. Simulation of plume dynamics by the Lattice Boltzmann Method

    Science.gov (United States)

    Mora, Peter; Yuen, David A.

    2017-09-01

    The Lattice Boltzmann Method (LBM) is a semi-microscopic method to simulate fluid mechanics by modelling distributions of particles moving and colliding on a lattice. We present 2-D simulations using the LBM of a fluid in a rectangular box being heated from below, and cooled from above, with a Rayleigh of Ra = 108, similar to current estimates of the Earth's mantle, and a Prandtl number of 5000. At this Prandtl number, the flow is found to be in the non-inertial regime where the inertial terms denoted I ≪ 1. Hence, the simulations presented lie within the regime of relevance for geodynamical problems. We obtain narrow upwelling plumes with mushroom heads and chutes of downwelling fluid as expected of a flow in the non-inertial regime. The method developed demonstrates that the LBM has great potential for simulating thermal convection and plume dynamics relevant to geodynamics, albeit with some limitations.

  9. A tool for simulating parallel branch-and-bound methods

    Science.gov (United States)

    Golubeva, Yana; Orlov, Yury; Posypkin, Mikhail

    2016-01-01

    The Branch-and-Bound method is known as one of the most powerful but very resource consuming global optimization methods. Parallel and distributed computing can efficiently cope with this issue. The major difficulty in parallel B&B method is the need for dynamic load redistribution. Therefore design and study of load balancing algorithms is a separate and very important research topic. This paper presents a tool for simulating parallel Branchand-Bound method. The simulator allows one to run load balancing algorithms with various numbers of processors, sizes of the search tree, the characteristics of the supercomputer's interconnect thereby fostering deep study of load distribution strategies. The process of resolution of the optimization problem by B&B method is replaced by a stochastic branching process. Data exchanges are modeled using the concept of logical time. The user friendly graphical interface to the simulator provides efficient visualization and convenient performance analysis.

  10. A tool for simulating parallel branch-and-bound methods

    Directory of Open Access Journals (Sweden)

    Golubeva Yana

    2016-01-01

    Full Text Available The Branch-and-Bound method is known as one of the most powerful but very resource consuming global optimization methods. Parallel and distributed computing can efficiently cope with this issue. The major difficulty in parallel B&B method is the need for dynamic load redistribution. Therefore design and study of load balancing algorithms is a separate and very important research topic. This paper presents a tool for simulating parallel Branchand-Bound method. The simulator allows one to run load balancing algorithms with various numbers of processors, sizes of the search tree, the characteristics of the supercomputer’s interconnect thereby fostering deep study of load distribution strategies. The process of resolution of the optimization problem by B&B method is replaced by a stochastic branching process. Data exchanges are modeled using the concept of logical time. The user friendly graphical interface to the simulator provides efficient visualization and convenient performance analysis.

  11. Using Simulation to Train Junior Psychiatry Residents to Work with Agitated Patients: A Pilot Study

    Science.gov (United States)

    Zigman, Daniel; Young, Meredith; Chalk, Colin

    2013-01-01

    Objective: This article examines the benefit and feasibility of introducing a new, simulation-based learning intervention for junior psychiatry residents. Method: Junior psychiatry residents were invited to participate in a new simulation-based learning intervention focusing on agitated patients. Questionnaires were used to explore the success of…

  12. Building patient safety in intensive care nursing : Patient safety culture, team performance and simulation-based training

    OpenAIRE

    Ballangrud, Randi

    2013-01-01

    Aim: The overall aim of the thesis was to investigate patient safety culture, team performance and the use of simulation-based team training for building patient safety in intensive care nursing. Methods: Quantitative and qualitative methods were used. In Study I, 220 RNs from ten ICUs responded to a patient safety culture questionnaire analysed with statistics. Studies II-IV were based on an evaluation of a simulation-based team training programme. Studies II-III included 53 RNs from seven I...

  13. Patient Simulation: A Literary Synthesis of Assessment Tools in Anesthesiology

    Directory of Open Access Journals (Sweden)

    Alice A. Edler

    2009-12-01

    Full Text Available High-fidelity patient simulation (HFPS has been hypothesized as a modality for assessing competency of knowledge and skill in patient simulation, but uniform methods for HFPS performance assessment (PA have not yet been completely achieved. Anesthesiology as a field founded the HFPS discipline and also leads in its PA. This project reviews the types, quality, and designated purpose of HFPS PA tools in anesthesiology. We used the systematic review method and systematically reviewed anesthesiology literature referenced in PubMed to assess the quality and reliability of available PA tools in HFPS. Of 412 articles identified, 50 met our inclusion criteria. Seventy seven percent of studies have been published since 2000; more recent studies demonstrated higher quality. Investigators reported a variety of test construction and validation methods. The most commonly reported test construction methods included “modified Delphi Techniques” for item selection, reliability measurement using inter-rater agreement, and intra-class correlations between test items or subtests. Modern test theory, in particular generalizability theory, was used in nine (18% of studies. Test score validity has been addressed in multiple investigations and shown a significant improvement in reporting accuracy. However the assessment of predicative has been low across the majority of studies. Usability and practicality of testing occasions and tools was only anecdotally reported. To more completely comply with the gold standards for PA design, both shared experience of experts and recognition of test construction standards, including reliability and validity measurements, instrument piloting, rater training, and explicit identification of the purpose and proposed use of the assessment tool, are required.

  14. Discrete event simulation modelling of patient service management with Arena

    Science.gov (United States)

    Guseva, Elena; Varfolomeyeva, Tatyana; Efimova, Irina; Movchan, Irina

    2018-05-01

    This paper describes the simulation modeling methodology aimed to aid in solving the practical problems of the research and analysing the complex systems. The paper gives the review of a simulation platform sand example of simulation model development with Arena 15.0 (Rockwell Automation).The provided example of the simulation model for the patient service management helps to evaluate the workload of the clinic doctors, determine the number of the general practitioners, surgeons, traumatologists and other specialized doctors required for the patient service and develop recommendations to ensure timely delivery of medical care and improve the efficiency of the clinic operation.

  15. Plasma simulations using the Car-Parrinello method

    International Nuclear Information System (INIS)

    Clerouin, J.; Zerah, G.; Benisti, D.; Hansen, J.P.

    1990-01-01

    A simplified version of the Car-Parrinello method, based on the Thomas-Fermi (local density) functional for the electrons, is adapted to the simulation of the ionic dynamics in dense plasmas. The method is illustrated by an explicit application to a degenerate one-dimensional hydrogen plasma

  16. Nonequilibrium relaxation method – An alternative simulation strategy

    Indian Academy of Sciences (India)

    One well-established simulation strategy to study the thermal phases and transitions of a given microscopic model system is the so-called equilibrium method, in which one first realizes the equilibrium ensemble of a finite system and then extrapolates the results to infinite system. This equilibrium method traces over the ...

  17. A direct simulation method for flows with suspended paramagnetic particles

    NARCIS (Netherlands)

    Kang, T.G.; Hulsen, M.A.; Toonder, den J.M.J.; Anderson, P.D.; Meijer, H.E.H.

    2008-01-01

    A direct numerical simulation method based on the Maxwell stress tensor and a fictitious domain method has been developed to solve flows with suspended paramagnetic particles. The numerical scheme enables us to take into account both hydrodynamic and magnetic interactions between particles in a

  18. DRK methods for time-domain oscillator simulation

    NARCIS (Netherlands)

    Sevat, M.F.; Houben, S.H.M.J.; Maten, ter E.J.W.; Di Bucchianico, A.; Mattheij, R.M.M.; Peletier, M.A.

    2006-01-01

    This paper presents a new Runge-Kutta type integration method that is well-suited for time-domain simulation of oscillators. A unique property of the new method is that its damping characteristics can be controlled by a continuous parameter.

  19. The afforestation problem: a heuristic method based on simulated annealing

    DEFF Research Database (Denmark)

    Vidal, Rene Victor Valqui

    1992-01-01

    This paper presents the afforestation problem, that is the location and design of new forest compartments to be planted in a given area. This optimization problem is solved by a two-step heuristic method based on simulated annealing. Tests and experiences with this method are also presented....

  20. Multilevel panel method for wind turbine rotor flow simulations

    NARCIS (Netherlands)

    van Garrel, Arne

    2016-01-01

    Simulation methods of wind turbine aerodynamics currently in use mainly fall into two categories: the first is the group of traditional low-fidelity engineering models and the second is the group of computationally expensive CFD methods based on the Navier-Stokes equations. For an engineering

  1. LOMEGA: a low frequency, field implicit method for plasma simulation

    International Nuclear Information System (INIS)

    Barnes, D.C.; Kamimura, T.

    1982-04-01

    Field implicit methods for low frequency plasma simulation by the LOMEGA (Low OMEGA) codes are described. These implicit field methods may be combined with particle pushing algorithms using either Lorentz force or guiding center force models to study two-dimensional, magnetized, electrostatic plasmas. Numerical results for ωsub(e)deltat>>1 are described. (author)

  2. Performance evaluation of sea surface simulation methods for target detection

    Science.gov (United States)

    Xia, Renjie; Wu, Xin; Yang, Chen; Han, Yiping; Zhang, Jianqi

    2017-11-01

    With the fast development of sea surface target detection by optoelectronic sensors, machine learning has been adopted to improve the detection performance. Many features can be learned from training images by machines automatically. However, field images of sea surface target are not sufficient as training data. 3D scene simulation is a promising method to address this problem. For ocean scene simulation, sea surface height field generation is the key point to achieve high fidelity. In this paper, two spectra-based height field generation methods are evaluated. Comparison between the linear superposition and linear filter method is made quantitatively with a statistical model. 3D ocean scene simulating results show the different features between the methods, which can give reference for synthesizing sea surface target images with different ocean conditions.

  3. Architecture oriented modeling and simulation method for combat mission profile

    Directory of Open Access Journals (Sweden)

    CHEN Xia

    2017-05-01

    Full Text Available In order to effectively analyze the system behavior and system performance of combat mission profile, an architecture-oriented modeling and simulation method is proposed. Starting from the architecture modeling,this paper describes the mission profile based on the definition from National Military Standard of China and the US Department of Defense Architecture Framework(DoDAFmodel, and constructs the architecture model of the mission profile. Then the transformation relationship between the architecture model and the agent simulation model is proposed to form the mission profile executable model. At last,taking the air-defense mission profile as an example,the agent simulation model is established based on the architecture model,and the input and output relations of the simulation model are analyzed. It provides method guidance for the combat mission profile design.

  4. A nondissipative simulation method for the drift kinetic equation

    International Nuclear Information System (INIS)

    Watanabe, Tomo-Hiko; Sugama, Hideo; Sato, Tetsuya

    2001-07-01

    With the aim to study the ion temperature gradient (ITG) driven turbulence, a nondissipative kinetic simulation scheme is developed and comprehensively benchmarked. The new simulation method preserving the time-reversibility of basic kinetic equations can successfully reproduce the analytical solutions of asymmetric three-mode ITG equations which are extended to provide a more general reference for benchmarking than the previous work [T.-H. Watanabe, H. Sugama, and T. Sato: Phys. Plasmas 7 (2000) 984]. It is also applied to a dissipative three-mode system, and shows a good agreement with the analytical solution. The nondissipative simulation result of the ITG turbulence accurately satisfies the entropy balance equation. Usefulness of the nondissipative method for the drift kinetic simulations is confirmed in comparisons with other dissipative schemes. (author)

  5. Adaptive implicit method for thermal compositional reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, A.; Tchelepi, H.A. [Society of Petroleum Engineers, Richardson, TX (United States)]|[Stanford Univ., Palo Alto (United States)

    2008-10-15

    As the global demand for oil increases, thermal enhanced oil recovery techniques are becoming increasingly important. Numerical reservoir simulation of thermal methods such as steam assisted gravity drainage (SAGD) is complex and requires a solution of nonlinear mass and energy conservation equations on a fine reservoir grid. The most currently used technique for solving these equations is the fully IMplicit (FIM) method which is unconditionally stable, allowing for large timesteps in simulation. However, it is computationally expensive. On the other hand, the method known as IMplicit pressure explicit saturations, temperature and compositions (IMPEST) is computationally inexpensive, but it is only conditionally stable and restricts the timestep size. To improve the balance between the timestep size and computational cost, the thermal adaptive IMplicit (TAIM) method uses stability criteria and a switching algorithm, where some simulation variables such as pressure, saturations, temperature, compositions are treated implicitly while others are treated with explicit schemes. This presentation described ongoing research on TAIM with particular reference to thermal displacement processes such as the stability criteria that dictate the maximum allowed timestep size for simulation based on the von Neumann linear stability analysis method; the switching algorithm that adapts labeling of reservoir variables as implicit or explicit as a function of space and time; and, complex physical behaviors such as heat and fluid convection, thermal conduction and compressibility. Key numerical results obtained by enhancing Stanford's General Purpose Research Simulator (GPRS) were also presented along with a list of research challenges. 14 refs., 2 tabs., 11 figs., 1 appendix.

  6. Evaluation of an improved method of simulating lung nodules in chest tomosynthesis

    International Nuclear Information System (INIS)

    Svalkvist, Angelica; Allansdotter Johnsson, Aase; Vikgren, Jenny

    2012-01-01

    Background Simulated pathology is a valuable complement to clinical images in studies aiming at evaluating an imaging technique. In order for a study using simulated pathology to be valid, it is important that the simulated pathology in a realistic way reflect the characteristics of real pathology. Purpose To perform a thorough evaluation of a nodule simulation method for chest tomosynthesis, comparing the detection rate and appearance of the artificial nodules with those of real nodules in an observer performance experiment. Material and Methods A cohort consisting of 64 patients, 38 patients with a total of 129 identified pulmonary nodules and 26 patients without identified pulmonary nodules, was used in the study. Simulated nodules, matching the real clinically found pulmonary nodules by size, attenuation, and location, were created and randomly inserted into the tomosynthesis section images of the patients. Three thoracic radiologists and one radiology resident reviewed the images in an observer performance study divided into two parts. The first part included nodule detection and the second part included rating of the visual appearance of the nodules. The results were evaluated using a modified receiver-operating characteristic (ROC) analysis. Results The sensitivities for real and simulated nodules were comparable, as the area under the modified ROC curve (AUC) was close to 0.5 for all observers (range, 0.43-0.55). Even though the ratings of visual appearance for real and simulated nodules overlapped considerably, the statistical analysis revealed that the observers to were able to separate simulated nodules from real nodules (AUC values range 0.70-0.74). Conclusion The simulation method can be used to create artificial lung nodules that have similar detectability as real nodules in chest tomosynthesis, although experienced thoracic radiologists may be able to distinguish them from real nodules

  7. Using Simulated Patients to Teach Clinical Nutrition.

    Science.gov (United States)

    Carroll, J. Gregory; And Others

    1983-01-01

    "Clinical Nutrition in an Interdisciplinary Setting" is a course designed to introduce basic nutrition knowledge and concepts of nutritional assessment, counseling, and intervention in the clinical care of patients. Provides a brief course overview and descriptions of its development, use, and preliminary evaluation of the patient simulation…

  8. A virtual source method for Monte Carlo simulation of Gamma Knife Model C

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hoon; Kim, Yong Kyun [Hanyang University, Seoul (Korea, Republic of); Chung, Hyun Tai [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2016-05-15

    The Monte Carlo simulation method has been used for dosimetry of radiation treatment. Monte Carlo simulation is the method that determines paths and dosimetry of particles using random number. Recently, owing to the ability of fast processing of the computers, it is possible to treat a patient more precisely. However, it is necessary to increase the simulation time to improve the efficiency of accuracy uncertainty. When generating the particles from the cobalt source in a simulation, there are many particles cut off. So it takes time to simulate more accurately. For the efficiency, we generated the virtual source that has the phase space distribution which acquired a single gamma knife channel. We performed the simulation using the virtual sources on the 201 channel and compared the measurement with the simulation using virtual sources and real sources. A virtual source file was generated to reduce the simulation time of a Gamma Knife Model C. Simulations with a virtual source executed about 50 times faster than the original source code and there was no statistically significant difference in simulated results.

  9. A virtual source method for Monte Carlo simulation of Gamma Knife Model C

    International Nuclear Information System (INIS)

    Kim, Tae Hoon; Kim, Yong Kyun; Chung, Hyun Tai

    2016-01-01

    The Monte Carlo simulation method has been used for dosimetry of radiation treatment. Monte Carlo simulation is the method that determines paths and dosimetry of particles using random number. Recently, owing to the ability of fast processing of the computers, it is possible to treat a patient more precisely. However, it is necessary to increase the simulation time to improve the efficiency of accuracy uncertainty. When generating the particles from the cobalt source in a simulation, there are many particles cut off. So it takes time to simulate more accurately. For the efficiency, we generated the virtual source that has the phase space distribution which acquired a single gamma knife channel. We performed the simulation using the virtual sources on the 201 channel and compared the measurement with the simulation using virtual sources and real sources. A virtual source file was generated to reduce the simulation time of a Gamma Knife Model C. Simulations with a virtual source executed about 50 times faster than the original source code and there was no statistically significant difference in simulated results

  10. Activity coefficients from molecular simulations using the OPAS method

    Science.gov (United States)

    Kohns, Maximilian; Horsch, Martin; Hasse, Hans

    2017-10-01

    A method for determining activity coefficients by molecular dynamics simulations is presented. It is an extension of the OPAS (osmotic pressure for the activity of the solvent) method in previous work for studying the solvent activity in electrolyte solutions. That method is extended here to study activities of all components in mixtures of molecular species. As an example, activity coefficients in liquid mixtures of water and methanol are calculated for 298.15 K and 323.15 K at 1 bar using molecular models from the literature. These dense and strongly interacting mixtures pose a significant challenge to existing methods for determining activity coefficients by molecular simulation. It is shown that the new method yields accurate results for the activity coefficients which are in agreement with results obtained with a thermodynamic integration technique. As the partial molar volumes are needed in the proposed method, the molar excess volume of the system water + methanol is also investigated.

  11. Innovative teaching methods in the professional training of nurses – simulation education

    Directory of Open Access Journals (Sweden)

    Michaela Miertová

    2013-12-01

    Full Text Available Introduction: The article is aimed to highlight usage of innovative teaching methods within simulation education in the professional training of nurses abroad and to present our experience based on passing intensive study programme at School of Nursing, Midwifery and Social Work, University of Salford (United Kingdom, UK within Intensive EU Lifelong Learning Programme (LPP Erasmus EU RADAR 2013. Methods: Implementation of simulation methods such as role-play, case studies, simulation scenarios, practical workshops and clinical skills workstation within structured ABCDE approach (AIM© Assessment and Management Tool was aimed to promote the development of theoretical knowledge and skills to recognize and manage acutely deteriorated patients. Structured SBAR approach (Acute SBAR Communication Tool was used for the training of communication and information sharing among the members of multidisciplinary health care team. OSCE approach (Objective Structured Clinical Examination was used for student’s individual formative assessment. Results: Simulation education is proved to have lots of benefits in the professional training of nurses. It is held in safe, controlled and realistic conditions (in simulation laboratories reflecting real hospital and community care environment with no risk of harming real patients accompanied by debriefing, discussion and analysis of all activities students have performed within simulated scenario. Such learning environment is supportive, challenging, constructive, motivated, engaging, skilled, flexible, inspiring and respectful. Thus the simulation education is effective, interactive, interesting, efficient and modern way of nursing education. Conclusion: Critical thinking and clinical competences of nurses are crucial for early recognition and appropriate response to acute deterioration of patient’s condition. These competences are important to ensure the provision of high quality nursing care. Methods of

  12. Simulation of the acoustic wave propagation using a meshless method

    Directory of Open Access Journals (Sweden)

    Bajko J.

    2017-01-01

    Full Text Available This paper presents numerical simulations of the acoustic wave propagation phenomenon modelled via Linearized Euler equations. A meshless method based on collocation of the strong form of the equation system is adopted. Moreover, the Weighted least squares method is used for local approximation of derivatives as well as stabilization technique in a form of spatial ltering. The accuracy and robustness of the method is examined on several benchmark problems.

  13. Numerical simulation methods for wave propagation through optical waveguides

    International Nuclear Information System (INIS)

    Sharma, A.

    1993-01-01

    The simulation of the field propagation through waveguides requires numerical solutions of the Helmholtz equation. For this purpose a method based on the principle of orthogonal collocation was recently developed. The method is also applicable to nonlinear pulse propagation through optical fibers. Some of the salient features of this method and its application to both linear and nonlinear wave propagation through optical waveguides are discussed in this report. 51 refs, 8 figs, 2 tabs

  14. Validity evidence and reliability of a simulated patient feedback instrument.

    NARCIS (Netherlands)

    Schlegel, C.; Woermann, U.; Rethans, J.J.; Vleuten, C.P.M. van der

    2012-01-01

    BACKGROUND: In the training of healthcare professionals, one of the advantages of communication training with simulated patients (SPs) is the SP's ability to provide direct feedback to students after a simulated clinical encounter. The quality of SP feedback must be monitored, especially because it

  15. An interprofessional course using human patient simulation to teach patient safety and teamwork skills.

    Science.gov (United States)

    Vyas, Deepti; McCulloh, Russell; Dyer, Carla; Gregory, Gretchen; Higbee, Dena

    2012-05-10

    To assess the effectiveness of human patient simulation to teach patient safety, team-building skills, and the value of interprofessional collaboration to pharmacy students. Five scenarios simulating semi-urgent situations that required interprofessional collaboration were developed. Groups of 10 to 12 health professions students that included 1 to 2 pharmacy students evaluated patients while addressing patient safety hazards. Pharmacy students' scores on 8 of 30 items on a post-simulation survey of knowledge, skills, and attitudes improved over pre-simulation scores. Students' scores on 3 of 10 items on a team building and interprofessional communications survey also improved after participating in the simulation exercise. Over 90% of students reported that simulation increased their understanding of professional roles and the importance of interprofessional communication. Simulation training provided an opportunity to improve pharmacy students' ability to recognize and react to patient safety concerns and enhanced their interprofessional collaboration and communication skills.

  16. Evacuation of Bed-bound Patients-STEPS Simulations

    DEFF Research Database (Denmark)

    Madsen, Anne; Dederichs, Anne Simone

    2016-01-01

    Fires in hospitals occur, and evacuation of bed-bound patients might be necessary in case of emergency. The current study concerns the evacuation of bed-bound patients from a fire section in a hospital using hospital porters. The simulations are performed using the STEPS program. The aim...... of the study is to investigate the evacuation time of bed-bound hospital patients using different walking speeds from the literature, and the influence of the number of hospital porters on the total evacuation times of bed-bound patients. Different scenarios were carried out with varying staff......-to-patient ratios that simulate the horizontal evacuation of 40 bed-bound patients into a different fire section. It was found that the staff-to-patient-ratio affects the total evacuation times. However, the total evacuation times do not decrease linearly and a saturation effect is seen at a staff-to-patient ratio...

  17. Advance in research on aerosol deposition simulation methods

    International Nuclear Information System (INIS)

    Liu Keyang; Li Jingsong

    2011-01-01

    A comprehensive analysis of the health effects of inhaled toxic aerosols requires exact data on airway deposition. A knowledge of the effect of inhaled drugs is essential to the optimization of aerosol drug delivery. Sophisticated analytical deposition models can be used for the computation of total, regional and generation specific deposition efficiencies. The continuously enhancing computer seem to allow us to study the particle transport and deposition in more and more realistic airway geometries with the help of computational fluid dynamics (CFD) simulation method. In this article, the trends in aerosol deposition models and lung models, and the methods for achievement of deposition simulations are also reviewed. (authors)

  18. Finite element method for simulation of the semiconductor devices

    International Nuclear Information System (INIS)

    Zikatanov, L.T.; Kaschiev, M.S.

    1991-01-01

    An iterative method for solving the system of nonlinear equations of the drift-diffusion representation for the simulation of the semiconductor devices is worked out. The Petrov-Galerkin method is taken for the discretization of these equations using the bilinear finite elements. It is shown that the numerical scheme is a monotonous one and there are no oscillations of the solutions in the region of p-n transition. The numerical calculations of the simulation of one semiconductor device are presented. 13 refs.; 3 figs

  19. Reliability analysis of neutron transport simulation using Monte Carlo method

    International Nuclear Information System (INIS)

    Souza, Bismarck A. de; Borges, Jose C.

    1995-01-01

    This work presents a statistical and reliability analysis covering data obtained by computer simulation of neutron transport process, using the Monte Carlo method. A general description of the method and its applications is presented. Several simulations, corresponding to slowing down and shielding problems have been accomplished. The influence of the physical dimensions of the materials and of the sample size on the reliability level of results was investigated. The objective was to optimize the sample size, in order to obtain reliable results, optimizing computation time. (author). 5 refs, 8 figs

  20. Computed tomographic simulation of craniospinal fields in pediatric patients: improved treatment accuracy and patient comfort.

    Science.gov (United States)

    Mah, K; Danjoux, C E; Manship, S; Makhani, N; Cardoso, M; Sixel, K E

    1998-07-15

    To reduce the time required for planning and simulating craniospinal fields through the use of a computed tomography (CT) simulator and virtual simulation, and to improve the accuracy of field and shielding placement. A CT simulation planning technique was developed. Localization of critical anatomic features such as the eyes, cribriform plate region, and caudal extent of the thecal sac are enhanced by this technique. Over a 2-month period, nine consecutive pediatric patients were simulated and planned for craniospinal irradiation. Four patients underwent both conventional simulation and CT simulation. Five were planned using CT simulation only. The accuracy of CT simulation was assessed by comparing digitally reconstructed radiographs (DRRs) to portal films for all patients and to conventional simulation films as well in the first four patients. Time spent by patients in the CT simulation suite was 20 min on average and 40 min maximally for those who were noncompliant. Image acquisition time was absence of the patient, virtual simulation of all fields took 20 min. The DRRs were in agreement with portal and/or simulation films to within 5 mm in five of the eight cases. Discrepancies of > or =5 mm in the positioning of the inferior border of the cranial fields in the first three patients were due to a systematic error in CT scan acquisition and marker contouring which was corrected by modifying the technique after the fourth patient. In one patient, the facial shield had to be moved 0.75 cm inferiorly owing to an error in shield construction. Our analysis showed that CT simulation of craniospinal fields was accurate. It resulted in a significant reduction in the time the patient must be immobilized during the planning process. This technique can improve accuracy in field placement and shielding by using three-dimensional CT-aided localization of critical and target structures. Overall, it has improved staff efficiency and resource utilization.

  1. The adaptation method in the Monte Carlo simulation for computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyoung Gun; Yoon, Chang Yeon; Lee, Won Ho [Dept. of Bio-convergence Engineering, Korea University, Seoul (Korea, Republic of); Cho, Seung Ryong [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Park, Sung Ho [Dept. of Neurosurgery, Ulsan University Hospital, Ulsan (Korea, Republic of)

    2015-06-15

    The patient dose incurred from diagnostic procedures during advanced radiotherapy has become an important issue. Many researchers in medical physics are using computational simulations to calculate complex parameters in experiments. However, extended computation times make it difficult for personal computers to run the conventional Monte Carlo method to simulate radiological images with high-flux photons such as images produced by computed tomography (CT). To minimize the computation time without degrading imaging quality, we applied a deterministic adaptation to the Monte Carlo calculation and verified its effectiveness by simulating CT image reconstruction for an image evaluation phantom (Catphan; Phantom Laboratory, New York NY, USA) and a human-like voxel phantom (KTMAN-2) (Los Alamos National Laboratory, Los Alamos, NM, USA). For the deterministic adaptation, the relationship between iteration numbers and the simulations was estimated and the option to simulate scattered radiation was evaluated. The processing times of simulations using the adaptive method were at least 500 times faster than those using a conventional statistical process. In addition, compared with the conventional statistical method, the adaptive method provided images that were more similar to the experimental images, which proved that the adaptive method was highly effective for a simulation that requires a large number of iterations-assuming no radiation scattering in the vicinity of detectors minimized artifacts in the reconstructed image.

  2. MONTE CARLO METHOD AND APPLICATION IN @RISK SIMULATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Gabriela Ižaríková

    2015-12-01

    Full Text Available The article is an example of using the software simulation @Risk designed for simulation in Microsoft Excel spread sheet, demonstrated the possibility of its usage in order to show a universal method of solving problems. The simulation is experimenting with computer models based on the real production process in order to optimize the production processes or the system. The simulation model allows performing a number of experiments, analysing them, evaluating, optimizing and afterwards applying the results to the real system. A simulation model in general is presenting modelling system by using mathematical formulations and logical relations. In the model is possible to distinguish controlled inputs (for instance investment costs and random outputs (for instance demand, which are by using a model transformed into outputs (for instance mean value of profit. In case of a simulation experiment at the beginning are chosen controlled inputs and random (stochastic outputs are generated randomly. Simulations belong into quantitative tools, which can be used as a support for a decision making.

  3. 3D immersive patient simulators and their impact on learning success: a thematic review.

    Science.gov (United States)

    Kleinert, Robert; Wahba, Roger; Chang, De-Hua; Plum, Patrick; Hölscher, Arnulf H; Stippel, Dirk L

    2015-04-08

    Immersive patient simulators (IPSs) combine the simulation of virtual patients with a three-dimensional (3D) environment and, thus, allow an illusionary immersion into a synthetic world, similar to computer games. Playful learning in a 3D environment is motivating and allows repetitive training and internalization of medical workflows (ie, procedural knowledge) without compromising real patients. The impact of this innovative educational concept on learning success requires review of feasibility and validity. It was the aim of this paper to conduct a survey of all immersive patient simulators currently available. In addition, we address the question of whether the use of these simulators has an impact on knowledge gain by summarizing the existing validation studies. A systematic literature search via PubMed was performed using predefined inclusion criteria (ie, virtual worlds, focus on education of medical students, validation testing) to identify all available simulators. Validation testing was defined as the primary end point. There are currently 13 immersive patient simulators available. Of these, 9 are Web-based simulators and represent feasibility studies. None of these simulators are used routinely for student education. The workstation-based simulators are commercially driven and show a higher quality in terms of graphical quality and/or data content. Out of the studies, 1 showed a positive correlation between simulated content and real content (ie, content validity). There was a positive correlation between the outcome of simulator training and alternative training methods (ie, concordance validity), and a positive coherence between measured outcome and future professional attitude and performance (ie, predictive validity). IPSs can promote learning and consolidation of procedural knowledge. The use of immersive patient simulators is still marginal, and technical and educational approaches are heterogeneous. Academic-driven IPSs could possibly enhance the

  4. Computational methods for coupling microstructural and micromechanical materials response simulations

    Energy Technology Data Exchange (ETDEWEB)

    HOLM,ELIZABETH A.; BATTAILE,CORBETT C.; BUCHHEIT,THOMAS E.; FANG,HUEI ELIOT; RINTOUL,MARK DANIEL; VEDULA,VENKATA R.; GLASS,S. JILL; KNOROVSKY,GERALD A.; NEILSEN,MICHAEL K.; WELLMAN,GERALD W.; SULSKY,DEBORAH; SHEN,YU-LIN; SCHREYER,H. BUCK

    2000-04-01

    Computational materials simulations have traditionally focused on individual phenomena: grain growth, crack propagation, plastic flow, etc. However, real materials behavior results from a complex interplay between phenomena. In this project, the authors explored methods for coupling mesoscale simulations of microstructural evolution and micromechanical response. In one case, massively parallel (MP) simulations for grain evolution and microcracking in alumina stronglink materials were dynamically coupled. In the other, codes for domain coarsening and plastic deformation in CuSi braze alloys were iteratively linked. this program provided the first comparison of two promising ways to integrate mesoscale computer codes. Coupled microstructural/micromechanical codes were applied to experimentally observed microstructures for the first time. In addition to the coupled codes, this project developed a suite of new computational capabilities (PARGRAIN, GLAD, OOF, MPM, polycrystal plasticity, front tracking). The problem of plasticity length scale in continuum calculations was recognized and a solution strategy was developed. The simulations were experimentally validated on stockpile materials.

  5. Recent advancements in medical simulation: patient-specific virtual reality simulation.

    Science.gov (United States)

    Willaert, Willem I M; Aggarwal, Rajesh; Van Herzeele, Isabelle; Cheshire, Nicholas J; Vermassen, Frank E

    2012-07-01

    Patient-specific virtual reality simulation (PSVR) is a new technological advancement that allows practice of upcoming real operations and complements the established role of VR simulation as a generic training tool. This review describes current developments in PSVR and draws parallels with other high-stake industries, such as aviation, military, and sports. A review of the literature was performed using PubMed and Internet search engines to retrieve data relevant to PSVR in medicine. All reports pertaining to PSVR were included. Reports on simulators that did not incorporate a haptic interface device were excluded from the review. Fifteen reports described 12 simulators that enabled PSVR. Medical procedures in the field of laparoscopy, vascular surgery, orthopedics, neurosurgery, and plastic surgery were included. In all cases, source data was two-dimensional CT or MRI data. Face validity was most commonly reported. Only one (vascular) simulator had undergone face, content, and construct validity. Of the 12 simulators, 1 is commercialized and 11 are prototypes. Five simulators have been used in conjunction with real patient procedures. PSVR is a promising technological advance within medicine. The majority of simulators are still in the prototype phase. As further developments unfold, the validity of PSVR will have to be examined much like generic VR simulation for training purposes. Nonetheless, similar to the aviation, military, and sport industries, operative performance and patient safety may be enhanced by the application of this novel technology.

  6. Simulation methods with extended stability for stiff biochemical Kinetics

    Directory of Open Access Journals (Sweden)

    Rué Pau

    2010-08-01

    Full Text Available Abstract Background With increasing computer power, simulating the dynamics of complex systems in chemistry and biology is becoming increasingly routine. The modelling of individual reactions in (biochemical systems involves a large number of random events that can be simulated by the stochastic simulation algorithm (SSA. The key quantity is the step size, or waiting time, τ, whose value inversely depends on the size of the propensities of the different channel reactions and which needs to be re-evaluated after every firing event. Such a discrete event simulation may be extremely expensive, in particular for stiff systems where τ can be very short due to the fast kinetics of some of the channel reactions. Several alternative methods have been put forward to increase the integration step size. The so-called τ-leap approach takes a larger step size by allowing all the reactions to fire, from a Poisson or Binomial distribution, within that step. Although the expected value for the different species in the reactive system is maintained with respect to more precise methods, the variance at steady state can suffer from large errors as τ grows. Results In this paper we extend Poisson τ-leap methods to a general class of Runge-Kutta (RK τ-leap methods. We show that with the proper selection of the coefficients, the variance of the extended τ-leap can be well-behaved, leading to significantly larger step sizes. Conclusions The benefit of adapting the extended method to the use of RK frameworks is clear in terms of speed of calculation, as the number of evaluations of the Poisson distribution is still one set per time step, as in the original τ-leap method. The approach paves the way to explore new multiscale methods to simulate (biochemical systems.

  7. High viscosity fluid simulation using particle-based method

    KAUST Repository

    Chang, Yuanzhang

    2011-03-01

    We present a new particle-based method for high viscosity fluid simulation. In the method, a new elastic stress term, which is derived from a modified form of the Hooke\\'s law, is included in the traditional Navier-Stokes equation to simulate the movements of the high viscosity fluids. Benefiting from the Lagrangian nature of Smoothed Particle Hydrodynamics method, large flow deformation can be well handled easily and naturally. In addition, in order to eliminate the particle deficiency problem near the boundary, ghost particles are employed to enforce the solid boundary condition. Compared with Finite Element Methods with complicated and time-consuming remeshing operations, our method is much more straightforward to implement. Moreover, our method doesn\\'t need to store and compare to an initial rest state. The experimental results show that the proposed method is effective and efficient to handle the movements of highly viscous flows, and a large variety of different kinds of fluid behaviors can be well simulated by adjusting just one parameter. © 2011 IEEE.

  8. Simulation of quantum systems by the tomography Monte Carlo method

    International Nuclear Information System (INIS)

    Bogdanov, Yu I

    2007-01-01

    A new method of statistical simulation of quantum systems is presented which is based on the generation of data by the Monte Carlo method and their purposeful tomography with the energy minimisation. The numerical solution of the problem is based on the optimisation of the target functional providing a compromise between the maximisation of the statistical likelihood function and the energy minimisation. The method does not involve complicated and ill-posed multidimensional computational procedures and can be used to calculate the wave functions and energies of the ground and excited stationary sates of complex quantum systems. The applications of the method are illustrated. (fifth seminar in memory of d.n. klyshko)

  9. Vectorization of a particle simulation method for hypersonic rarefied flow

    Science.gov (United States)

    Mcdonald, Jeffrey D.; Baganoff, Donald

    1988-01-01

    An efficient particle simulation technique for hypersonic rarefied flows is presented at an algorithmic and implementation level. The implementation is for a vector computer architecture, specifically the Cray-2. The method models an ideal diatomic Maxwell molecule with three translational and two rotational degrees of freedom. Algorithms are designed specifically for compatibility with fine grain parallelism by reducing the number of data dependencies in the computation. By insisting on this compatibility, the method is capable of performing simulation on a much larger scale than previously possible. A two-dimensional simulation of supersonic flow over a wedge is carried out for the near-continuum limit where the gas is in equilibrium and the ideal solution can be used as a check on the accuracy of the gas model employed in the method. Also, a three-dimensional, Mach 8, rarefied flow about a finite-span flat plate at a 45 degree angle of attack was simulated. It utilized over 10 to the 7th particles carried through 400 discrete time steps in less than one hour of Cray-2 CPU time. This problem was chosen to exhibit the capability of the method in handling a large number of particles and a true three-dimensional geometry.

  10. A multiscale quantum mechanics/electromagnetics method for device simulations.

    Science.gov (United States)

    Yam, ChiYung; Meng, Lingyi; Zhang, Yu; Chen, GuanHua

    2015-04-07

    Multiscale modeling has become a popular tool for research applying to different areas including materials science, microelectronics, biology, chemistry, etc. In this tutorial review, we describe a newly developed multiscale computational method, incorporating quantum mechanics into electronic device modeling with the electromagnetic environment included through classical electrodynamics. In the quantum mechanics/electromagnetics (QM/EM) method, the regions of the system where active electron scattering processes take place are treated quantum mechanically, while the surroundings are described by Maxwell's equations and a semiclassical drift-diffusion model. The QM model and the EM model are solved, respectively, in different regions of the system in a self-consistent manner. Potential distributions and current densities at the interface between QM and EM regions are employed as the boundary conditions for the quantum mechanical and electromagnetic simulations, respectively. The method is illustrated in the simulation of several realistic systems. In the case of junctionless field-effect transistors, transfer characteristics are obtained and a good agreement between experiments and simulations is achieved. Optical properties of a tandem photovoltaic cell are studied and the simulations demonstrate that multiple QM regions are coupled through the classical EM model. Finally, the study of a carbon nanotube-based molecular device shows the accuracy and efficiency of the QM/EM method.

  11. A mixed finite element method for particle simulation in lasertron

    International Nuclear Information System (INIS)

    Le Meur, G.

    1987-03-01

    A particle simulation code is being developed with the aim to treat the motion of charged particles in electromagnetic devices, such as Lasertron. The paper describes the use of mixed finite element methods in computing the field components, without derivating them from scalar or vector potentials. Graphical results are shown

  12. A simulation based engineering method to support HAZOP studies

    DEFF Research Database (Denmark)

    Enemark-Rasmussen, Rasmus; Cameron, David; Angelo, Per Bagge

    2012-01-01

    the conventional HAZOP procedure. The method systematically generates failure scenarios by considering process equipment deviations with pre-defined failure modes. The effect of failure scenarios is then evaluated using dynamic simulations -in this study the K-Spice® software used. The consequences of each failure...

  13. Vectorization of a particle simulation method for hypersonic rarefied flow

    International Nuclear Information System (INIS)

    Mcdonald, J.D.; Baganoff, D.

    1988-01-01

    An efficient particle simulation technique for hypersonic rarefied flows is presented at an algorithmic and implementation level. The implementation is for a vector computer architecture, specifically the Cray-2. The method models an ideal diatomic Maxwell molecule with three translational and two rotational degrees of freedom. Algorithms are designed specifically for compatibility with fine grain parallelism by reducing the number of data dependencies in the computation. By insisting on this compatibility, the method is capable of performing simulation on a much larger scale than previously possible. A two-dimensional simulation of supersonic flow over a wedge is carried out for the near-continuum limit where the gas is in equilibrium and the ideal solution can be used as a check on the accuracy of the gas model employed in the method. Also, a three-dimensional, Mach 8, rarefied flow about a finite-span flat plate at a 45 degree angle of attack was simulated. It utilized over 10 to the 7th particles carried through 400 discrete time steps in less than one hour of Cray-2 CPU time. This problem was chosen to exhibit the capability of the method in handling a large number of particles and a true three-dimensional geometry. 14 references

  14. Correction of measured multiplicity distributions by the simulated annealing method

    International Nuclear Information System (INIS)

    Hafidouni, M.

    1993-01-01

    Simulated annealing is a method used to solve combinatorial optimization problems. It is used here for the correction of the observed multiplicity distribution from S-Pb collisions at 200 GeV/c per nucleon. (author) 11 refs., 2 figs

  15. Kinematics and simulation methods to determine the target thickness

    International Nuclear Information System (INIS)

    Rosales, P.; Aguilar, E.F.; Martinez Q, E.

    2001-01-01

    Making use of the kinematics and of the particles energy loss two methods for calculating the thickness of a target are described. Through a computer program and other of simulation in which parameters obtained experimentally are used. Several values for a 12 C target thickness were obtained. It is presented a comparison of the obtained values with each one of the used programs. (Author)

  16. A mixed finite element method for particle simulation in Lasertron

    International Nuclear Information System (INIS)

    Le Meur, G.

    1987-01-01

    A particle simulation code is being developed with the aim to treat the motion of charged particles in electromagnetic devices, such as Lasertron. The paper describes the use of mixed finite element methods in computing the field components, without derivating them from scalar or vector potentials. Graphical results are shown

  17. Dynamical simulation of heavy ion collisions; VUU and QMD method

    International Nuclear Information System (INIS)

    Niita, Koji

    1992-01-01

    We review two simulation methods based on the Vlasov-Uehling-Uhlenbeck (VUU) equation and Quantum Molecular Dynamics (QMD), which are the most widely accepted theoretical framework for the description of intermediate-energy heavy-ion reactions. We show some results of the calculations and compare them with the experimental data. (author)

  18. Simulating water hammer with corrective smoothed particle method

    NARCIS (Netherlands)

    Hou, Q.; Kruisbrink, A.C.H.; Tijsseling, A.S.; Keramat, A.

    2012-01-01

    The corrective smoothed particle method (CSPM) is used to simulate water hammer. The spatial derivatives in the water-hammer equations are approximated by a corrective kernel estimate. For the temporal derivatives, the Euler-forward time integration algorithm is employed. The CSPM results are in

  19. STUDY ON SIMULATION METHOD OF AVALANCHE : FLOW ANALYSIS OF AVALANCHE USING PARTICLE METHOD

    OpenAIRE

    塩澤, 孝哉

    2015-01-01

    In this paper, modeling for the simulation of the avalanche by a particle method is discussed. There are two kinds of the snow avalanches, one is the surface avalanche which shows a smoke-like flow, and another is the total-layer avalanche which shows a flow like Bingham fluid. In the simulation of the surface avalanche, the particle method in consideration of a rotation resistance model is used. The particle method by Bingham fluid is used in the simulation of the total-layer avalanche. At t...

  20. Efficient method for transport simulations in quantum cascade lasers

    Directory of Open Access Journals (Sweden)

    Maczka Mariusz

    2017-01-01

    Full Text Available An efficient method for simulating quantum transport in quantum cascade lasers is presented. The calculations are performed within a simple approximation inspired by Büttiker probes and based on a finite model for semiconductor superlattices. The formalism of non-equilibrium Green’s functions is applied to determine the selected transport parameters in a typical structure of a terahertz laser. Results were compared with those obtained for a infinite model as well as other methods described in literature.

  1. A method of simulating and visualizing nuclear reactions

    International Nuclear Information System (INIS)

    Atwood, C.H.; Paul, K.M.

    1994-01-01

    Teaching nuclear reactions to students is difficult because the mechanisms are complex and directly visualizing them is impossible. As a teaching tool, the authors have developed a method of simulating nuclear reactions using colliding water droplets. Videotaping of the collisions, taken with a high shutter speed camera and run frame-by-frame, shows details of the collisions that are analogous to nuclear reactions. The method for colliding the water drops and videotaping the collisions are shown

  2. Meshfree simulation of avalanches with the Finite Pointset Method (FPM)

    Science.gov (United States)

    Michel, Isabel; Kuhnert, Jörg; Kolymbas, Dimitrios

    2017-04-01

    Meshfree methods are the numerical method of choice in case of applications which are characterized by strong deformations in conjunction with free surfaces or phase boundaries. In the past the meshfree Finite Pointset Method (FPM) developed by Fraunhofer ITWM (Kaiserslautern, Germany) has been successfully applied to problems in computational fluid dynamics such as water crossing of cars, water turbines, and hydraulic valves. Most recently the simulation of granular flows, e.g. soil interaction with cars (rollover), has also been tackled. This advancement is the basis for the simulation of avalanches. Due to the generalized finite difference formulation in FPM, the implementation of different material models is quite simple. We will demonstrate 3D simulations of avalanches based on the Drucker-Prager yield criterion as well as the nonlinear barodesy model. The barodesy model (Division of Geotechnical and Tunnel Engineering, University of Innsbruck, Austria) describes the mechanical behavior of soil by an evolution equation for the stress tensor. The key feature of successful and realistic simulations of avalanches - apart from the numerical approximation of the occurring differential operators - is the choice of the boundary conditions (slip, no-slip, friction) between the different phases of the flow as well as the geometry. We will discuss their influences for simplified one- and two-phase flow examples. This research is funded by the German Research Foundation (DFG) and the FWF Austrian Science Fund.

  3. Simulation of the radiography formation process from CT patient volume

    Energy Technology Data Exchange (ETDEWEB)

    Bifulco, P; Cesarelli, M; Verso, E; Roccasalva Firenze, M; Sansone, M; Bracale, M [University of Naples, Federico II, Electronic Engineering Department, Bioengineering Unit, Via Claudio, 21 - 80125 Naples (Italy)

    1999-12-31

    The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors) 16 refs., 12 figs., 1 tabs.

  4. Simulation of the radiography formation process from CT patient volume

    International Nuclear Information System (INIS)

    Bifulco, P.; Cesarelli, M.; Verso, E.; Roccasalva Firenze, M.; Sansone, M.; Bracale, M.

    1998-01-01

    The aim of this work is to develop an algorithm to simulate the radiographic image formation process using volumetric anatomical data of the patient, obtained from 3D diagnostic CT images. Many applications, including radiographic driven surgery, virtual reality in medicine and radiologist teaching and training, may take advantage of such technique. The designed algorithm has been developed to simulate a generic radiographic equipment, whatever oriented respect to the patient. The simulated radiography is obtained considering a discrete number of X-ray paths departing from the focus, passing through the patient volume and reaching the radiographic plane. To evaluate a generic pixel of the simulated radiography, the cumulative absorption along the corresponding X-ray is computed. To estimate X-ray absorption in a generic point of the patient volume, 3D interpolation of CT data has been adopted. The proposed technique is quite similar to those employed in Ray Tracing. A computer designed test volume has been used to assess the reliability of the radiography simulation algorithm as a measuring tool. From the errors analysis emerges that the accuracy achieved by the radiographic simulation algorithm is largely confined within the sampling step of the CT volume. (authors)

  5. The Multiple-Patient Simulation Toolkit: Purpose, Process, and Pilot.

    Science.gov (United States)

    Beroz, Sabrina; Sullivan, Nancy; Kramasz, Vanessa; Morgan, Patricia

    Educating nursing students to safely care for multiple patients has become an important but challenging focus for nurse educators. New graduate nurses are expected to manage care for multiple patients in a complex and multifaceted health care system. With patient safety as a priority, multiple-patient assignments are necessary in order for nursing students to learn how to effectively prioritize and delegate care. The purpose of this project was the construction of an adaptable and flexible template for the development of multiple-patient simulations. Through utilization, the template moved to a toolkit adding an operational guide, sample-populated template, and bibliography.

  6. Does the sex of a simulated patient affect CPR?

    Science.gov (United States)

    Kramer, Chelsea E; Wilkins, Matthew S; Davies, Jan M; Caird, Jeff K; Hallihan, Gregory M

    2015-01-01

    While males and females are equally at risk of sudden cardiac arrest (SCA), females are less likely to be resuscitated. Cardiopulmonary Resuscitation (CPR) may be inhibited by socio-cultural norms about exposing female victims' chests. Empirically confirming this hypothesis is limited by lack of patient simulators modeling realistic female physiques. A commercially-available patient simulator was transformed to evaluate how physical attributes of a patient's sex might influence lay participants who were asked to resuscitate a female versus a male during simulated cardiac arrest. Sixty-nine participants consented to be in the study. Participants were randomly assigned to provide CPR and defibrillation as instructed by a commercially-available automated external defibrillator on a patient simulator presented as either a male or female experiencing cardiac arrest. Rescuers removed significantly more clothing from the male than the female, with men removing less clothing from the female. More rescuers' initial hand placements for CPR were centered between the female's breasts compared to the male, on which placement was distributed across the chest towards the nipples. While rescuers had better hand placement for CPR on the female, both men and women rescuers were reluctant to remove the female's clothing, with men significantly more hesitant. Reticence to remove clothing was often articulated relative to social norms during structured interviews. We suggest that using only male simulators will not allow trainees to experience social differences associated with the care of a female simulated patient. Realistic female patient simulators are needed. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  7. Patient identification errors are common in a simulated setting.

    Science.gov (United States)

    Henneman, Philip L; Fisher, Donald L; Henneman, Elizabeth A; Pham, Tuan A; Campbell, Megan M; Nathanson, Brian H

    2010-06-01

    We evaluate the frequency and accuracy of health care workers verifying patient identity before performing common tasks. The study included prospective, simulated patient scenarios with an eye-tracking device that showed where the health care workers looked. Simulations involved nurses administering an intravenous medication, technicians labeling a blood specimen, and clerks applying an identity band. Participants were asked to perform their assigned task on 3 simulated patients, and the third patient had a different date of birth and medical record number than the identity information on the artifact label specific to the health care workers' task. Health care workers were unaware that the focus of the study was patient identity. Sixty-one emergency health care workers participated--28 nurses, 16 technicians, and 17 emergency service associates--in 183 patient scenarios. Sixty-one percent of health care workers (37/61) caught the identity error (61% nurses, 94% technicians, 29% emergency service associates). Thirty-nine percent of health care workers (24/61) performed their assigned task on the wrong patient (39% nurses, 6% technicians, 71% emergency service associates). Eye-tracking data were available for 73% of the patient scenarios (133/183). Seventy-four percent of health care workers (74/100) failed to match the patient to the identity band (87% nurses, 49% technicians). Twenty-seven percent of health care workers (36/133) failed to match the artifact to the patient or the identity band before performing their task (33% nurses, 9% technicians, 33% emergency service associates). Fifteen percent (5/33) of health care workers who completed the steps to verify patient identity on the patient with the identification error still failed to recognize the error. Wide variation exists among health care workers verifying patient identity before performing everyday tasks. Education, process changes, and technology are needed to improve the frequency and accuracy of

  8. Assessing methods for dealing with treatment switching in randomised controlled trials: a simulation study

    Directory of Open Access Journals (Sweden)

    Latimer Nicholas

    2011-01-01

    Full Text Available Abstract Background We investigate methods used to analyse the results of clinical trials with survival outcomes in which some patients switch from their allocated treatment to another trial treatment. These included simple methods which are commonly used in medical literature and may be subject to selection bias if patients switching are not typical of the population as a whole. Methods which attempt to adjust the estimated treatment effect, either through adjustment to the hazard ratio or via accelerated failure time models, were also considered. A simulation study was conducted to assess the performance of each method in a number of different scenarios. Results 16 different scenarios were identified which differed by the proportion of patients switching, underlying prognosis of switchers and the size of true treatment effect. 1000 datasets were simulated for each of these and all methods applied. Selection bias was observed in simple methods when the difference in survival between switchers and non-switchers were large. A number of methods, particularly the AFT method of Branson and Whitehead were found to give less biased estimates of the true treatment effect in these situations. Conclusions Simple methods are often not appropriate to deal with treatment switching. Alternative approaches such as the Branson & Whitehead method to adjust for switching should be considered.

  9. Modified network simulation model with token method of bus access

    Directory of Open Access Journals (Sweden)

    L.V. Stribulevich

    2013-08-01

    Full Text Available Purpose. To study the characteristics of the local network with the marker method of access to the bus its modified simulation model was developed. Methodology. Defining characteristics of the network is carried out on the developed simulation model, which is based on the state diagram-layer network station with the mechanism of processing priorities, both in steady state and in the performance of control procedures: the initiation of a logical ring, the entrance and exit of the station network with a logical ring. Findings. A simulation model, on the basis of which can be obtained the dependencies of the application the maximum waiting time in the queue for different classes of access, and the reaction time usable bandwidth on the data rate, the number of network stations, the generation rate applications, the number of frames transmitted per token holding time, frame length was developed. Originality. The technique of network simulation reflecting its work in the steady condition and during the control procedures, the mechanism of priority ranking and handling was proposed. Practical value. Defining network characteristics in the real-time systems on railway transport based on the developed simulation model.

  10. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid; van Oort, Eric; Patzek, Tadeusz

    2018-01-01

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  11. Thermal shale fracturing simulation using the Cohesive Zone Method (CZM)

    KAUST Repository

    Enayatpour, Saeid

    2018-05-17

    Extensive research has been conducted over the past two decades to improve hydraulic fracturing methods used for hydrocarbon recovery from tight reservoir rocks such as shales. Our focus in this paper is on thermal fracturing of such tight rocks to enhance hydraulic fracturing efficiency. Thermal fracturing is effective in generating small fractures in the near-wellbore zone - or in the vicinity of natural or induced fractures - that may act as initiation points for larger fractures. Previous analytical and numerical results indicate that thermal fracturing in tight rock significantly enhances rock permeability, thereby enhancing hydrocarbon recovery. Here, we present a more powerful way of simulating the initiation and propagation of thermally induced fractures in tight formations using the Cohesive Zone Method (CZM). The advantages of CZM are: 1) CZM simulation is fast compared to similar models which are based on the spring-mass particle method or Discrete Element Method (DEM); 2) unlike DEM, rock material complexities such as scale-dependent failure behavior can be incorporated in a CZM simulation; 3) CZM is capable of predicting the extent of fracture propagation in rock, which is more difficult to determine in a classic finite element approach. We demonstrate that CZM delivers results for the challenging fracture propagation problem of similar accuracy to the eXtended Finite Element Method (XFEM) while reducing complexity and computational effort. Simulation results for thermal fracturing in the near-wellbore zone show the effect of stress anisotropy in fracture propagation in the direction of the maximum horizontal stress. It is shown that CZM can be used to readily obtain the extent and the pattern of induced thermal fractures.

  12. Hybrid numerical methods for multiscale simulations of subsurface biogeochemical processes

    International Nuclear Information System (INIS)

    Scheibe, T D; Tartakovsky, A M; Tartakovsky, D M; Redden, G D; Meakin, P

    2007-01-01

    Many subsurface flow and transport problems of importance today involve coupled non-linear flow, transport, and reaction in media exhibiting complex heterogeneity. In particular, problems involving biological mediation of reactions fall into this class of problems. Recent experimental research has revealed important details about the physical, chemical, and biological mechanisms involved in these processes at a variety of scales ranging from molecular to laboratory scales. However, it has not been practical or possible to translate detailed knowledge at small scales into reliable predictions of field-scale phenomena important for environmental management applications. A large assortment of numerical simulation tools have been developed, each with its own characteristic scale. Important examples include 1. molecular simulations (e.g., molecular dynamics); 2. simulation of microbial processes at the cell level (e.g., cellular automata or particle individual-based models); 3. pore-scale simulations (e.g., lattice-Boltzmann, pore network models, and discrete particle methods such as smoothed particle hydrodynamics); and 4. macroscopic continuum-scale simulations (e.g., traditional partial differential equations solved by finite difference or finite element methods). While many problems can be effectively addressed by one of these models at a single scale, some problems may require explicit integration of models across multiple scales. We are developing a hybrid multi-scale subsurface reactive transport modeling framework that integrates models with diverse representations of physics, chemistry and biology at different scales (sub-pore, pore and continuum). The modeling framework is being designed to take advantage of advanced computational technologies including parallel code components using the Common Component Architecture, parallel solvers, gridding, data and workflow management, and visualization. This paper describes the specific methods/codes being used at each

  13. Discrete Particle Method for Simulating Hypervelocity Impact Phenomena

    Directory of Open Access Journals (Sweden)

    Erkai Watson

    2017-04-01

    Full Text Available In this paper, we introduce a computational model for the simulation of hypervelocity impact (HVI phenomena which is based on the Discrete Element Method (DEM. Our paper constitutes the first application of DEM to the modeling and simulating of impact events for velocities beyond 5 kms-1. We present here the results of a systematic numerical study on HVI of solids. For modeling the solids, we use discrete spherical particles that interact with each other via potentials. In our numerical investigations we are particularly interested in the dynamics of material fragmentation upon impact. We model a typical HVI experiment configuration where a sphere strikes a thin plate and investigate the properties of the resulting debris cloud. We provide a quantitative computational analysis of the resulting debris cloud caused by impact and a comprehensive parameter study by varying key parameters of our model. We compare our findings from the simulations with recent HVI experiments performed at our institute. Our findings are that the DEM method leads to very stable, energy–conserving simulations of HVI scenarios that map the experimental setup where a sphere strikes a thin plate at hypervelocity speed. Our chosen interaction model works particularly well in the velocity range where the local stresses caused by impact shock waves markedly exceed the ultimate material strength.

  14. Discrete Event Simulation of Patient Admissions to a Neurovascular Unit

    Directory of Open Access Journals (Sweden)

    S. Hahn-Goldberg

    2014-01-01

    Full Text Available Evidence exists that clinical outcomes improve for stroke patients admitted to specialized Stroke Units. The Toronto Western Hospital created a Neurovascular Unit (NVU using beds from general internal medicine, Neurology and Neurosurgery to care for patients with stroke and acute neurovascular conditions. Using patient-level data for NVU-eligible patients, a discrete event simulation was created to study changes in patient flow and length of stay pre- and post-NVU implementation. Varying patient volumes and resources were tested to determine the ideal number of beds under various conditions. In the first year of operation, the NVU admitted 507 patients, over 66% of NVU-eligible patient volumes. With the introduction of the NVU, length of stay decreased by around 8%. Scenario testing showed that the current level of 20 beds is sufficient for accommodating the current demand and would continue to be sufficient with an increase in demand of up to 20%.

  15. Utilization of simulated patients to assess diabetes and asthma counseling practices among community pharmacists in Qatar.

    Science.gov (United States)

    Paravattil, Bridget; Kheir, Nadir; Yousif, Adil

    2017-08-01

    Background Patient counseling is one of the most important services a pharmacist can provide to patients. Studies have shown that counseling provided by pharmacists may prevent medication related problems and improve adherence to medication therapy. Objective To explore counseling practices among community pharmacists using simulated patients and to determine if patient, pharmacist, and pharmacy characteristics influence the counseling provided by community pharmacists. Setting Private community pharmacies within Qatar. Method This is a randomized, cross sectional study where simulated patients visited community pharmacies and presented the pharmacist with a new prescription or requested a refill for either a diabetes or asthma medication. Pharmacists completed a questionnaire at the end of the simulated interaction, which was utilized to determine if patient, pharmacist, or pharmacy characteristics had any influence on the counseling provided to patients. A scoring system was devised to assess the pharmacist's counseling practices. Main outcome measure To evaluate the type of information provided by community pharmacists to the simulated patient regarding diabetes and asthma. Results One hundred and twenty-nine pharmacists were enrolled in the study. Eighty one percent of pharmacists had a score master of pharmacy degree provided significantly better counseling (f = 3.261; p = 0.042). Many pharmacists (65%) provided hypoglycemia management to patients, however, 63% referred the patient to the physician when the patient experienced hypoglycemia from inappropriate medication administration. Only 2 (7%) pharmacists correctly counseled the patient on all 8 inhaler administration steps. Majority of pharmacists (50%) educated on the role of the rescue and controller therapy in asthma, however, 33% referred the patient to the physician when the patient inquired about controller therapy use. Conclusion Patient counseling was substandard with the majority of community

  16. Experiences using DAKOTA stochastic expansion methods in computational simulations.

    Energy Technology Data Exchange (ETDEWEB)

    Templeton, Jeremy Alan; Ruthruff, Joseph R.

    2012-01-01

    Uncertainty quantification (UQ) methods bring rigorous statistical connections to the analysis of computational and experiment data, and provide a basis for probabilistically assessing margins associated with safety and reliability. The DAKOTA toolkit developed at Sandia National Laboratories implements a number of UQ methods, which are being increasingly adopted by modeling and simulation teams to facilitate these analyses. This report disseminates results as to the performance of DAKOTA's stochastic expansion methods for UQ on a representative application. Our results provide a number of insights that may be of interest to future users of these methods, including the behavior of the methods in estimating responses at varying probability levels, and the expansion levels for the methodologies that may be needed to achieve convergence.

  17. Quantum control with NMR methods: Application to quantum simulations

    International Nuclear Information System (INIS)

    Negrevergne, Camille

    2002-01-01

    Manipulating information according to quantum laws allows improvements in the efficiency of the way we treat certain problems. Liquid state Nuclear Magnetic Resonance methods allow us to initialize, manipulate and read the quantum state of a system of coupled spins. These methods have been used to realize an experimental small Quantum Information Processor (QIP) able to process information through around hundred elementary operations. One of the main themes of this work was to design, optimize and validate reliable RF-pulse sequences used to 'program' the QIP. Such techniques have been used to run a quantum simulation algorithm for anionic systems. Some experimental results have been obtained on the determination of Eigen energies and correlation function for a toy problem consisting of fermions on a lattice, showing an experimental proof of principle for such quantum simulations. (author) [fr

  18. From fuel cells to batteries: Synergies, scales and simulation methods

    OpenAIRE

    Bessler, Wolfgang G.

    2011-01-01

    The recent years have shown a dynamic growth of battery research and development activities both in academia and industry, supported by large governmental funding initiatives throughout the world. A particular focus is being put on lithium-based battery technologies. This situation provides a stimulating environment for the fuel cell modeling community, as there are considerable synergies in the modeling and simulation methods for fuel cells and batteries. At the same time, batter...

  19. Application of subset simulation methods to dynamic fault tree analysis

    International Nuclear Information System (INIS)

    Liu Mengyun; Liu Jingquan; She Ding

    2015-01-01

    Although fault tree analysis has been implemented in the nuclear safety field over the past few decades, it was recently criticized for the inability to model the time-dependent behaviors. Several methods are proposed to overcome this disadvantage, and dynamic fault tree (DFT) has become one of the research highlights. By introducing additional dynamic gates, DFT is able to describe the dynamic behaviors like the replacement of spare components or the priority of failure events. Using Monte Carlo simulation (MCS) approach to solve DFT has obtained rising attention, because it can model the authentic behaviors of systems and avoid the limitations in the analytical method. In this paper, it provides an overview and MCS information for DFT analysis, including the sampling of basic events and the propagation rule for logic gates. When calculating rare-event probability, large amount of simulations in standard MCS are required. To improve the weakness, subset simulation (SS) approach is applied. Using the concept of conditional probability and Markov Chain Monte Carlo (MCMC) technique, the SS method is able to accelerate the efficiency of exploring the failure region. Two cases are tested to illustrate the performance of SS approach, and the numerical results suggest that it gives high efficiency when calculating complicated systems with small failure probabilities. (author)

  20. A computer method for simulating the decay of radon daughters

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1988-01-01

    The analytical equations representing the decay of a series of radioactive atoms through a number of daughter products are well known. These equations are for an idealized case in which the expectation value of the number of atoms which decay in a certain time can be represented by a smooth curve. The real curve of the total number of disintegrations from a radioactive species consists of a series of Heaviside step functions, with the steps occurring at the time of the disintegration. The disintegration of radioactive atoms is said to be random but this random behaviour is such that a single species forms an ensemble of which the times of disintegration give a geometric distribution. Numbers which have a geometric distribution can be generated by computer and can be used to simulate the decay of one or more radioactive species. A computer method is described for simulating such decay of radioactive atoms and this method is applied specifically to the decay of the short half life daughters of radon 222 and the emission of alpha particles from polonium 218 and polonium 214. Repeating the simulation of the decay a number of times provides a method for investigating the statistical uncertainty inherent in methods for measurement of exposure to radon daughters. This statistical uncertainty is difficult to investigate analytically since the time of decay of an atom of polonium 218 is not independent of the time of decay of subsequent polonium 214. The method is currently being used to investigate the statistical uncertainties of a number of commonly used methods for the counting of alpha particles from radon daughters and the calculations of exposure

  1. Display methods of electronic patient record screens: patient privacy concerns.

    Science.gov (United States)

    Niimi, Yukari; Ota, Katsumasa

    2013-01-01

    To provide adequate care, medical professionals have to collect not only medical information but also information that may be related to private aspects of the patient's life. With patients' increasing awareness of information privacy, healthcare providers have to pay attention to the patients' right of privacy. This study aimed to clarify the requirements of the display method of electronic patient record (EPR) screens in consideration of both patients' information privacy concerns and health professionals' information needs. For this purpose, semi-structured group interviews were conducted of 78 medical professionals. They pointed out that partial concealment of information to meet patients' requests for privacy could result in challenges in (1) safety in healthcare, (2) information sharing, (3) collaboration, (4) hospital management, and (5) communication. They believed that EPRs should (1) meet the requirements of the therapeutic process, (2) have restricted access, (3) provide convenient access to necessary information, and (4) facilitate interprofessional collaboration. This study provides direction for the development of display methods that balance the sharing of vital information and protection of patient privacy.

  2. Simulation research to enhance patient safety and outcomes: recommendations of the Simnovate Patient Safety Domain Group

    OpenAIRE

    Pucher, PH; Tamblyn, R; Boorman, D; Dixon-Woods, Mary Margaret; Donaldson, L; Draycott, T; Forster, A; Nadkarni, V; Power, C; Sevdalis, N; Aggarwal, R

    2017-01-01

    The use of simulation-based training has established itself in healthcare but its implementation has been varied and mostly limited to technical and non-technical skills training. This article discusses the possibilities of the use of simulation as part of an overarching approach to improving patient safety, and represents the views of the Simnovate Patient Safety Domain Group, an international multidisciplinary expert group dedicated to the improvement of patient safety. The application and ...

  3. IMPROVING MEDICAL EDUCATION: SIMULATING CHANGES IN PATIENT ANATOMY USING DYNAMIC HAPTIC FEEDBACK.

    Science.gov (United States)

    Yovanoff, Mary; Pepley, David; Mirkin, Katelin; Moore, Jason; Han, David; Miller, Scarlett

    2016-09-01

    Virtual simulation is an emerging field in medical education. Research suggests that simulation reduces complication rates and improves learning gains for medical residents. One benefit of simulators is their allowance for more realistic and dynamic patient anatomies. While potentially useful throughout medical education, few studies have explored the impact of dynamic haptic simulators on medical training. In light of this research void, this study was developed to examine how a Dynamic-Haptic Robotic Trainer (DHRT) impacts medical student self-efficacy and skill gains compared to traditional simulators developed to train students in Internal Jugular Central Venous Catheter (IJ CVC) placement. The study was conducted with 18 third year medical students with no prior CVC insertion experience who underwent a pre-test, simulator training (manikin, robotic, or mixed) and post-test. The results revealed the DHRT as a useful method for training CVC skills and supports further research on dynamic haptic trainers in medical education.

  4. Atmosphere Re-Entry Simulation Using Direct Simulation Monte Carlo (DSMC Method

    Directory of Open Access Journals (Sweden)

    Francesco Pellicani

    2016-05-01

    Full Text Available Hypersonic re-entry vehicles aerothermodynamic investigations provide fundamental information to other important disciplines like materials and structures, assisting the development of thermal protection systems (TPS efficient and with a low weight. In the transitional flow regime, where thermal and chemical equilibrium is almost absent, a new numerical method for such studies has been introduced, the direct simulation Monte Carlo (DSMC numerical technique. The acceptance and applicability of the DSMC method have increased significantly in the 50 years since its invention thanks to the increase in computer speed and to the parallel computing. Anyway, further verification and validation efforts are needed to lead to its greater acceptance. In this study, the Monte Carlo simulator OpenFOAM and Sparta have been studied and benchmarked against numerical and theoretical data for inert and chemically reactive flows and the same will be done against experimental data in the near future. The results show the validity of the data found with the DSMC. The best setting of the fundamental parameters used by a DSMC simulator are presented for each software and they are compared with the guidelines deriving from the theory behind the Monte Carlo method. In particular, the number of particles per cell was found to be the most relevant parameter to achieve valid and optimized results. It is shown how a simulation with a mean value of one particle per cell gives sufficiently good results with very low computational resources. This achievement aims to reconsider the correct investigation method in the transitional regime where both the direct simulation Monte Carlo (DSMC and the computational fluid-dynamics (CFD can work, but with a different computational effort.

  5. A particle finite element method for machining simulations

    Science.gov (United States)

    Sabel, Matthias; Sator, Christian; Müller, Ralf

    2014-07-01

    The particle finite element method (PFEM) appears to be a convenient technique for machining simulations, since the geometry and topology of the problem can undergo severe changes. In this work, a short outline of the PFEM-algorithm is given, which is followed by a detailed description of the involved operations. The -shape method, which is used to track the topology, is explained and tested by a simple example. Also the kinematics and a suitable finite element formulation are introduced. To validate the method simple settings without topological changes are considered and compared to the standard finite element method for large deformations. To examine the performance of the method, when dealing with separating material, a tensile loading is applied to a notched plate. This investigation includes a numerical analysis of the different meshing parameters, and the numerical convergence is studied. With regard to the cutting simulation it is found that only a sufficiently large number of particles (and thus a rather fine finite element discretisation) leads to converged results of process parameters, such as the cutting force.

  6. Multigrid Methods for Fully Implicit Oil Reservoir Simulation

    Science.gov (United States)

    Molenaar, J.

    1996-01-01

    In this paper we consider the simultaneous flow of oil and water in reservoir rock. This displacement process is modeled by two basic equations: the material balance or continuity equations and the equation of motion (Darcy's law). For the numerical solution of this system of nonlinear partial differential equations there are two approaches: the fully implicit or simultaneous solution method and the sequential solution method. In the sequential solution method the system of partial differential equations is manipulated to give an elliptic pressure equation and a hyperbolic (or parabolic) saturation equation. In the IMPES approach the pressure equation is first solved, using values for the saturation from the previous time level. Next the saturations are updated by some explicit time stepping method; this implies that the method is only conditionally stable. For the numerical solution of the linear, elliptic pressure equation multigrid methods have become an accepted technique. On the other hand, the fully implicit method is unconditionally stable, but it has the disadvantage that in every time step a large system of nonlinear algebraic equations has to be solved. The most time-consuming part of any fully implicit reservoir simulator is the solution of this large system of equations. Usually this is done by Newton's method. The resulting systems of linear equations are then either solved by a direct method or by some conjugate gradient type method. In this paper we consider the possibility of applying multigrid methods for the iterative solution of the systems of nonlinear equations. There are two ways of using multigrid for this job: either we use a nonlinear multigrid method or we use a linear multigrid method to deal with the linear systems that arise in Newton's method. So far only a few authors have reported on the use of multigrid methods for fully implicit simulations. Two-level FAS algorithm is presented for the black-oil equations, and linear multigrid for

  7. Radon movement simulation in overburden by the 'Scattered Packet Method'

    International Nuclear Information System (INIS)

    Marah, H.; Sabir, A.; Hlou, L.; Tayebi, M.

    1998-01-01

    The analysis of Radon ( 222 Rn) movement in overburden needs the resolution of the General Equation of Transport in porous medium, involving diffusion and convection. Generally this equation was derived and solved analytically. The 'Scattered Packed Method' is a recent mathematical method of resolution, initially developed for the electrons movements in the semiconductors studies. In this paper, we have adapted this method to simulate radon emanation in porous medium. The keys parameters are the radon concentration at the source, the diffusion coefficient, and the geometry. To show the efficiency of this method, several cases of increasing complexity are considered. This model allows to follow the migration, in the time and space, of radon produced as a function of the characteristics of the studied site. Forty soil radon measurements were taken from a North Moroccan fault. Forward modeling of the radon anomalies produces satisfactory fits of the observed data and allows the overburden thickness determination. (author)

  8. Evaluation of null-point detection methods on simulation data

    Science.gov (United States)

    Olshevsky, Vyacheslav; Fu, Huishan; Vaivads, Andris; Khotyaintsev, Yuri; Lapenta, Giovanni; Markidis, Stefano

    2014-05-01

    We model the measurements of artificial spacecraft that resemble the configuration of CLUSTER propagating in the particle-in-cell simulation of turbulent magnetic reconnection. The simulation domain contains multiple isolated X-type null-points, but the majority are O-type null-points. Simulations show that current pinches surrounded by twisted fields, analogous to laboratory pinches, are formed along the sequences of O-type nulls. In the simulation, the magnetic reconnection is mainly driven by the kinking of the pinches, at spatial scales of several ion inertial lentghs. We compute the locations of magnetic null-points and detect their type. When the satellites are separated by the fractions of ion inertial length, as it is for CLUSTER, they are able to locate both the isolated null-points, and the pinches. We apply the method to the real CLUSTER data and speculate how common are pinches in the magnetosphere, and whether they play a dominant role in the dissipation of magnetic energy.

  9. Five Topics Health Care Simulation Can Address to Improve Patient Safety

    DEFF Research Database (Denmark)

    Sollid, Stephen J M; Dieckman, Peter; Aase, Karina

    2017-01-01

    OBJECTIVES: There is little knowledge about which elements of health care simulation are most effective in improving patient safety. When empirical evidence is lacking, a consensus statement can help define priorities in, for example, education and research. A consensus process was therefore...... initiated to define priorities in health care simulation that contribute the most to improve patient safety.  METHODS: An international group of experts took part in a 4-stage consensus process based on a modified nominal group technique. Stages 1 to 3 were based on electronic communication; stage 4 was a 2......-day consensus meeting at the Utstein Abbey in Norway. The goals of stage 4 were to agree on the top 5 topics in health care simulation that contribute the most to patient safety, identify the patient safety problems they relate to, and suggest solutions with implementation strategies...

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

    International Nuclear Information System (INIS)

    Berthiau, G.

    1995-10-01

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

  11. A fast mollified impulse method for biomolecular atomistic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Fath, L., E-mail: lukas.fath@kit.edu [Institute for App. and Num. Mathematics, Karlsruhe Institute of Technology (Germany); Hochbruck, M., E-mail: marlis.hochbruck@kit.edu [Institute for App. and Num. Mathematics, Karlsruhe Institute of Technology (Germany); Singh, C.V., E-mail: chandraveer.singh@utoronto.ca [Department of Materials Science & Engineering, University of Toronto (Canada)

    2017-03-15

    Classical integration methods for molecular dynamics are inherently limited due to resonance phenomena occurring at certain time-step sizes. The mollified impulse method can partially avoid this problem by using appropriate filters based on averaging or projection techniques. However, existing filters are computationally expensive and tedious in implementation since they require either analytical Hessians or they need to solve nonlinear systems from constraints. In this work we follow a different approach based on corotation for the construction of a new filter for (flexible) biomolecular simulations. The main advantages of the proposed filter are its excellent stability properties and ease of implementation in standard softwares without Hessians or solving constraint systems. By simulating multiple realistic examples such as peptide, protein, ice equilibrium and ice–ice friction, the new filter is shown to speed up the computations of long-range interactions by approximately 20%. The proposed filtered integrators allow step sizes as large as 10 fs while keeping the energy drift less than 1% on a 50 ps simulation.

  12. Numerical method for IR background and clutter simulation

    Science.gov (United States)

    Quaranta, Carlo; Daniele, Gina; Balzarotti, Giorgio

    1997-06-01

    The paper describes a fast and accurate algorithm of IR background noise and clutter generation for application in scene simulations. The process is based on the hypothesis that background might be modeled as a statistical process where amplitude of signal obeys to the Gaussian distribution rule and zones of the same scene meet a correlation function with exponential form. The algorithm allows to provide an accurate mathematical approximation of the model and also an excellent fidelity with reality, that appears from a comparison with images from IR sensors. The proposed method shows advantages with respect to methods based on the filtering of white noise in time or frequency domain as it requires a limited number of computation and, furthermore, it is more accurate than the quasi random processes. The background generation starts from a reticule of few points and by means of growing rules the process is extended to the whole scene of required dimension and resolution. The statistical property of the model are properly maintained in the simulation process. The paper gives specific attention to the mathematical aspects of the algorithm and provides a number of simulations and comparisons with real scenes.

  13. Simulation of patient encounters using a virtual patient in periodontology instruction of dental students: design, usability, and learning effects in history-taking skills

    DEFF Research Database (Denmark)

    Janda, M.S.; Mattheos, N.; Nattestad, A.

    2004-01-01

    computer-assisted learning, effectiveness of learning, health education, patient simulation, virtual patient......computer-assisted learning, effectiveness of learning, health education, patient simulation, virtual patient...

  14. Viscoelastic Earthquake Cycle Simulation with Memory Variable Method

    Science.gov (United States)

    Hirahara, K.; Ohtani, M.

    2017-12-01

    There have so far been no EQ (earthquake) cycle simulations, based on RSF (rate and state friction) laws, in viscoelastic media, except for Kato (2002), who simulated cycles on a 2-D vertical strike-slip fault, and showed nearly the same cycles as those in elastic cases. The viscoelasticity could, however, give more effects on large dip-slip EQ cycles. In a boundary element approach, stress is calculated using a hereditary integral of stress relaxation function and slip deficit rate, where we need the past slip rates, leading to huge computational costs. This is a cause for almost no simulations in viscoelastic media. We have investigated the memory variable method utilized in numerical computation of wave propagation in dissipative media (e.g., Moczo and Kristek, 2005). In this method, introducing memory variables satisfying 1st order differential equations, we need no hereditary integrals in stress calculation and the computational costs are the same order of those in elastic cases. Further, Hirahara et al. (2012) developed the iterative memory variable method, referring to Taylor et al. (1970), in EQ cycle simulations in linear viscoelastic media. In this presentation, first, we introduce our method in EQ cycle simulations and show the effect of the linear viscoelasticity on stick-slip cycles in a 1-DOF block-SLS (standard linear solid) model, where the elastic spring of the traditional block-spring model is replaced by SLS element and we pull, in a constant rate, the block obeying RSF law. In this model, the memory variable stands for the displacement of the dash-pot in SLS element. The use of smaller viscosity reduces the recurrence time to a minimum value. The smaller viscosity means the smaller relaxation time, which makes the stress recovery quicker, leading to the smaller recurrence time. Second, we show EQ cycles on a 2-D dip-slip fault with the dip angel of 20 degrees in an elastic layer with thickness of 40 km overriding a Maxwell viscoelastic half

  15. Creation and Delphi-method refinement of pediatric disaster triage simulations.

    Science.gov (United States)

    Cicero, Mark X; Brown, Linda; Overly, Frank; Yarzebski, Jorge; Meckler, Garth; Fuchs, Susan; Tomassoni, Anthony; Aghababian, Richard; Chung, Sarita; Garrett, Andrew; Fagbuyi, Daniel; Adelgais, Kathleen; Goldman, Ran; Parker, James; Auerbach, Marc; Riera, Antonio; Cone, David; Baum, Carl R

    2014-01-01

    There is a need for rigorously designed pediatric disaster triage (PDT) training simulations for paramedics. First, we sought to design three multiple patient incidents for EMS provider training simulations. Our second objective was to determine the appropriate interventions and triage level for each victim in each of the simulations and develop evaluation instruments for each simulation. The final objective was to ensure that each simulation and evaluation tool was free of bias toward any specific PDT strategy. We created mixed-methods disaster simulation scenarios with pediatric victims: a school shooting, a school bus crash, and a multiple-victim house fire. Standardized patients, high-fidelity manikins, and low-fidelity manikins were used to portray the victims. Each simulation had similar acuity of injuries and 10 victims. Examples include children with special health-care needs, gunshot wounds, and smoke inhalation. Checklist-based evaluation tools and behaviorally anchored global assessments of function were created for each simulation. Eight physicians and paramedics from areas with differing PDT strategies were recruited as Subject Matter Experts (SMEs) for a modified Delphi iterative critique of the simulations and evaluation tools. The modified Delphi was managed with an online survey tool. The SMEs provided an expected triage category for each patient. The target for modified Delphi consensus was ≥85%. Using Likert scales and free text, the SMEs assessed the validity of the simulations, including instances of bias toward a specific PDT strategy, clarity of learning objectives, and the correlation of the evaluation tools to the learning objectives and scenarios. After two rounds of the modified Delphi, consensus for expected triage level was >85% for 28 of 30 victims, with the remaining two achieving >85% consensus after three Delphi iterations. To achieve consensus, we amended 11 instances of bias toward a specific PDT strategy and corrected 10

  16. Amyloid oligomer structure characterization from simulations: A general method

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Phuong H., E-mail: phuong.nguyen@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Li, Mai Suan [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Derreumaux, Philippe, E-mail: philippe.derreumaux@ibpc.fr [Laboratoire de Biochimie Théorique, UPR 9080, CNRS Université Denis Diderot, Sorbonne Paris Cité IBPC, 13 rue Pierre et Marie Curie, 75005 Paris (France); Institut Universitaire de France, 103 Bvd Saint-Germain, 75005 Paris (France)

    2014-03-07

    Amyloid oligomers and plaques are composed of multiple chemically identical proteins. Therefore, one of the first fundamental problems in the characterization of structures from simulations is the treatment of the degeneracy, i.e., the permutation of the molecules. Second, the intramolecular and intermolecular degrees of freedom of the various molecules must be taken into account. Currently, the well-known dihedral principal component analysis method only considers the intramolecular degrees of freedom, and other methods employing collective variables can only describe intermolecular degrees of freedom at the global level. With this in mind, we propose a general method that identifies all the structures accurately. The basis idea is that the intramolecular and intermolecular states are described in terms of combinations of single-molecule and double-molecule states, respectively, and the overall structures of oligomers are the product basis of the intramolecular and intermolecular states. This way, the degeneracy is automatically avoided. The method is illustrated on the conformational ensemble of the tetramer of the Alzheimer's peptide Aβ{sub 9−40}, resulting from two atomistic molecular dynamics simulations in explicit solvent, each of 200 ns, starting from two distinct structures.

  17. Limitations in simulator time-based human reliability analysis methods

    International Nuclear Information System (INIS)

    Wreathall, J.

    1989-01-01

    Developments in human reliability analysis (HRA) methods have evolved slowly. Current methods are little changed from those of almost a decade ago, particularly in the use of time-reliability relationships. While these methods were suitable as an interim step, the time (and the need) has come to specify the next evolution of HRA methods. As with any performance-oriented data source, power plant simulator data have no direct connection to HRA models. Errors reported in data are normal deficiencies observed in human performance; failures are events modeled in probabilistic risk assessments (PRAs). Not all errors cause failures; not all failures are caused by errors. Second, the times at which actions are taken provide no measure of the likelihood of failures to act correctly within an accident scenario. Inferences can be made about human reliability, but they must be made with great care. Specific limitations are discussed. Simulator performance data are useful in providing qualitative evidence of the variety of error types and their potential influences on operating systems. More work is required to combine recent developments in the psychology of error with the qualitative data collected at stimulators. Until data become openly available, however, such an advance will not be practical

  18. Debriefing after Human Patient Simulation and Nursing Students' Learning

    Science.gov (United States)

    Benhuri, Gloria

    2014-01-01

    Human Patient Simulation (HPS) exercises with life-like computerized manikins provide clinical experiences for nursing students in a safe environment followed by debriefing that promotes learning. Quantitative research in techniques to support learning from debriefing is limited. The purpose of the quantitative quasi-experimental study using a…

  19. [Does simulator-based team training improve patient safety?].

    Science.gov (United States)

    Trentzsch, H; Urban, B; Sandmeyer, B; Hammer, T; Strohm, P C; Lazarovici, M

    2013-10-01

    Patient safety became paramount in medicine as well as in emergency medicine after it was recognized that preventable, adverse events significantly contributed to morbidity and mortality during hospital stay. The underlying errors cannot usually be explained by medical technical inadequacies only but are more due to difficulties in the transition of theoretical knowledge into tasks under the conditions of clinical reality. Crew Resource Management and Human Factors which determine safety and efficiency of humans in complex situations are suitable to control such sources of error. Simulation significantly improved safety in high reliability organizations, such as the aerospace industry.Thus, simulator-based team training has also been proposed for medical areas. As such training is consuming in cost, time and human resources, the question of the cost-benefit ratio obviously arises. This review outlines the effects of simulator-based team training on patient safety. Such course formats are not only capable of creating awareness and improvements in safety culture but also improve technical team performance and emphasize team performance as a clinical competence. A few studies even indicated improvement of patient-centered outcome, such as a reduced rate of adverse events but further studies are required in this respect. In summary, simulator-based team training should be accepted as a suitable strategy to improve patient safety.

  20. Artificial skin and patient simulator comprising the artificial skin

    NARCIS (Netherlands)

    2011-01-01

    The invention relates to an artificial skin (10, 12, 14), and relates to a patient simulator (100) comprising the artificial skin. The artificial skin is a layered structure comprising a translucent cover layer (20) configured for imitating human or animal skin, and comprising a light emitting layer

  1. Hardware-in-the-loop grid simulator system and method

    Science.gov (United States)

    Fox, John Curtiss; Collins, Edward Randolph; Rigas, Nikolaos

    2017-05-16

    A hardware-in-the-loop (HIL) electrical grid simulation system and method that combines a reactive divider with a variable frequency converter to better mimic and control expected and unexpected parameters in an electrical grid. The invention provides grid simulation in a manner to allow improved testing of variable power generators, such as wind turbines, and their operation once interconnected with an electrical grid in multiple countries. The system further comprises an improved variable fault reactance (reactive divider) capable of providing a variable fault reactance power output to control a voltage profile, therein creating an arbitrary recovery voltage. The system further comprises an improved isolation transformer designed to isolate zero-sequence current from either a primary or secondary winding in a transformer or pass the zero-sequence current from a primary to a secondary winding.

  2. Simulating condensation on microstructured surfaces using Lattice Boltzmann Method

    Science.gov (United States)

    Alexeev, Alexander; Vasyliv, Yaroslav

    2017-11-01

    We simulate a single component fluid condensing on 2D structured surfaces with different wettability. To simulate the two phase fluid, we use the athermal Lattice Boltzmann Method (LBM) driven by a pseudopotential force. The pseudopotential force results in a non-ideal equation of state (EOS) which permits liquid-vapor phase change. To account for thermal effects, the athermal LBM is coupled to a finite volume discretization of the temperature evolution equation obtained using a thermal energy rate balance for the specific internal energy. We use the developed model to probe the effect of surface structure and surface wettability on the condensation rate in order to identify microstructure topographies promoting condensation. Financial support is acknowledged from Kimberly-Clark.

  3. Validity evidence and reliability of a simulated patient feedback instrument.

    Science.gov (United States)

    Schlegel, Claudia; Woermann, Ulrich; Rethans, Jan-Joost; van der Vleuten, Cees

    2012-01-27

    In the training of healthcare professionals, one of the advantages of communication training with simulated patients (SPs) is the SP's ability to provide direct feedback to students after a simulated clinical encounter. The quality of SP feedback must be monitored, especially because it is well known that feedback can have a profound effect on student performance. Due to the current lack of valid and reliable instruments to assess the quality of SP feedback, our study examined the validity and reliability of one potential instrument, the 'modified Quality of Simulated Patient Feedback Form' (mQSF). Content validity of the mQSF was assessed by inviting experts in the area of simulated clinical encounters to rate the importance of the mQSF items. Moreover, generalizability theory was used to examine the reliability of the mQSF. Our data came from videotapes of clinical encounters between six simulated patients and six students and the ensuing feedback from the SPs to the students. Ten faculty members judged the SP feedback according to the items on the mQSF. Three weeks later, this procedure was repeated with the same faculty members and recordings. All but two items of the mQSF received importance ratings of > 2.5 on a four-point rating scale. A generalizability coefficient of 0.77 was established with two judges observing one encounter. The findings for content validity and reliability with two judges suggest that the mQSF is a valid and reliable instrument to assess the quality of feedback provided by simulated patients.

  4. Adaptive mesh refinement and adjoint methods in geophysics simulations

    Science.gov (United States)

    Burstedde, Carsten

    2013-04-01

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

  5. Modeling and simulation of different and representative engineering problems using Network Simulation Method.

    Science.gov (United States)

    Sánchez-Pérez, J F; Marín, F; Morales, J L; Cánovas, M; Alhama, F

    2018-01-01

    Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model.

  6. Modeling and simulation of different and representative engineering problems using Network Simulation Method

    Science.gov (United States)

    2018-01-01

    Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model. PMID:29518121

  7. Simulation of Rossi-α method with analog Monte-Carlo method

    International Nuclear Information System (INIS)

    Lu Yuzhao; Xie Qilin; Song Lingli; Liu Hangang

    2012-01-01

    The analog Monte-Carlo code for simulating Rossi-α method based on Geant4 was developed. The prompt neutron decay constant α of six metal uranium configurations in Oak Ridge National Laboratory were calculated. α was also calculated by Burst-Neutron method and the result was consistent with the result of Rossi-α method. There is the difference between results of analog Monte-Carlo simulation and experiment, and the reasons for the difference is the gaps between uranium layers. The influence of gaps decrease as the sub-criticality deepens. The relative difference between results of analog Monte-Carlo simulation and experiment changes from 19% to 0.19%. (authors)

  8. Reduction Methods for Real-time Simulations in Hybrid Testing

    DEFF Research Database (Denmark)

    Andersen, Sebastian

    2016-01-01

    Hybrid testing constitutes a cost-effective experimental full scale testing method. The method was introduced in the 1960's by Japanese researchers, as an alternative to conventional full scale testing and small scale material testing, such as shake table tests. The principle of the method...... is performed on a glass fibre reinforced polymer composite box girder. The test serves as a pilot test for prospective real-time tests on a wind turbine blade. The Taylor basis is implemented in the test, used to perform the numerical simulations. Despite of a number of introduced errors in the real...... is to divide a structure into a physical substructure and a numerical substructure, and couple these in a test. If the test is conducted in real-time it is referred to as real time hybrid testing. The hybrid testing concept has developed significantly since its introduction in the 1960', both with respect...

  9. Assessing the performance and satisfaction of medical residents utilizing standardized patient versus mannequin-simulated training

    Directory of Open Access Journals (Sweden)

    Alsaad AA

    2017-07-01

    Full Text Available Ali A Alsaad,1 Swetha Davuluri,2 Vandana Y Bhide,3 Amy M Lannen,4 Michael J Maniaci3 1Department of Internal Medicine, Mayo Clinic, 2University of Miami, Coral Gables, 3Division of Hospital Internal Medicine, 4J. Wayne and Delores Barr Weaver Simulation Center, Mayo Clinic, Jacksonville, FL, USA Background: Conducting simulations of rapidly decompensating patients are a key part of internal medicine (IM residency training. Traditionally, mannequins have been the simulation tool used in these scenarios. Objective: To compare IM residents’ performance and assess realism in specific-simulated decompensating patient scenarios using standardized patients (SPs as compared to mannequin. Methods: Nineteen IM residents were randomized to undergo simulations using either a mannequin or an SP. Each resident in the two groups underwent four different simulation scenarios (calcium channel blocker overdose, severe sepsis, severe asthma exacerbation, and acute bacterial meningitis. Residents completed pretest and post-test evaluations as well as a questionnaire to assess the reality perception (realism score. Results: Nine residents completed mannequin-based scenarios, whereas 10 completed SP-based scenarios. Improvement in the post-test scores was seen in both groups. However, there were significantly higher post-test scores achieved with SP simulations in three out of the four scenarios (P=0.01. When compared with the mannequin group, the SP simulation group showed a significantly higher average realism score (P=0.002. Conclusions: Applying SP-based specific-simulation scenarios in IM residency training may result in better performance and a higher sense of a realistic experience by medical residents. Keywords: simulation, standardized patient, satisfaction, mannequin, assessment, resident education

  10. Situation awareness in undergraduate nursing students managing simulated patient deterioration.

    Science.gov (United States)

    McKenna, Lisa; Missen, Karen; Cooper, Simon; Bogossian, Fiona; Bucknall, Tracey; Cant, Robyn

    2014-06-01

    Nursing work often occurs in complex and potentially hazardous settings. Awareness of patient and practice environments is an imperative for nurses in practice. To explore nursing students' situation awareness while engaging in simulated patient deterioration scenarios. The educational process of FIRST(2)ACT was the model for the nurse intervention. Situation awareness was measured quantitatively using the Situation Awareness Global Assessment tool. Four domains were measured: physiological perception (patient parameters), global perception (surroundings), comprehension (interpretation of information), and projection (forecasting outcomes). Clinical laboratories at each of three participating universities. Ninety-seven nursing students from three Australian universities. Between March and July 2012, students participated in three video-recorded simulation events, in which a trained actor played patient roles and groups of three students worked as teams. To measure situation awareness, following the simulation each team leader was taken to a separate room and asked to report on a question set regarding the patient's vital signs, bedside setting and medical diagnosis. Overall, situation awareness was low (41%). Of the four domains, physiological perceptions scored the lowest (26%) and projection the highest (59%). Final year nursing students may not have well developed situation awareness skills, especially when dealing with these types of scenarios. Education providers need to consider ways to assist students to fully develop this attribute. Findings suggest that this is an aspect of undergraduate nursing education that requires significant consideration by curriculum developers. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  11. A java based simulator with user interface to simulate ventilated patients

    Directory of Open Access Journals (Sweden)

    Stehle P.

    2015-09-01

    Full Text Available Mechanical ventilation is a life-saving intervention, which despite its use on a routine basis, poses the risk of inflicting further damage to the lung tissue if ventilator settings are chosen inappropriately. Medical decision support systems may help to prevent such injuries while providing the optimal settings to reach a defined clinical goal. In order to develop and verify decision support algorithms, a test bench simulating a patient’s behaviour is needed. We propose a Java based system that allows simulation of respiratory mechanics, gas exchange and cardiovascular dynamics of a mechanically ventilated patient. The implemented models are allowed to interact and are interchangeable enabling the simulation of various clinical scenarios. Model simulations are running in real-time and show physiologically plausible results.

  12. Development of modelling method selection tool for health services management: from problem structuring methods to modelling and simulation methods.

    Science.gov (United States)

    Jun, Gyuchan T; Morris, Zoe; Eldabi, Tillal; Harper, Paul; Naseer, Aisha; Patel, Brijesh; Clarkson, John P

    2011-05-19

    There is an increasing recognition that modelling and simulation can assist in the process of designing health care policies, strategies and operations. However, the current use is limited and answers to questions such as what methods to use and when remain somewhat underdeveloped. The aim of this study is to provide a mechanism for decision makers in health services planning and management to compare a broad range of modelling and simulation methods so that they can better select and use them or better commission relevant modelling and simulation work. This paper proposes a modelling and simulation method comparison and selection tool developed from a comprehensive literature review, the research team's extensive expertise and inputs from potential users. Twenty-eight different methods were identified, characterised by their relevance to different application areas, project life cycle stages, types of output and levels of insight, and four input resources required (time, money, knowledge and data). The characterisation is presented in matrix forms to allow quick comparison and selection. This paper also highlights significant knowledge gaps in the existing literature when assessing the applicability of particular approaches to health services management, where modelling and simulation skills are scarce let alone money and time. A modelling and simulation method comparison and selection tool is developed to assist with the selection of methods appropriate to supporting specific decision making processes. In particular it addresses the issue of which method is most appropriate to which specific health services management problem, what the user might expect to be obtained from the method, and what is required to use the method. In summary, we believe the tool adds value to the scarce existing literature on methods comparison and selection.

  13. Rapid simulation of spatial epidemics: a spectral method.

    Science.gov (United States)

    Brand, Samuel P C; Tildesley, Michael J; Keeling, Matthew J

    2015-04-07

    Spatial structure and hence the spatial position of host populations plays a vital role in the spread of infection. In the majority of situations, it is only possible to predict the spatial spread of infection using simulation models, which can be computationally demanding especially for large population sizes. Here we develop an approximation method that vastly reduces this computational burden. We assume that the transmission rates between individuals or sub-populations are determined by a spatial transmission kernel. This kernel is assumed to be isotropic, such that the transmission rate is simply a function of the distance between susceptible and infectious individuals; as such this provides the ideal mechanism for modelling localised transmission in a spatial environment. We show that the spatial force of infection acting on all susceptibles can be represented as a spatial convolution between the transmission kernel and a spatially extended 'image' of the infection state. This representation allows the rapid calculation of stochastic rates of infection using fast-Fourier transform (FFT) routines, which greatly improves the computational efficiency of spatial simulations. We demonstrate the efficiency and accuracy of this fast spectral rate recalculation (FSR) method with two examples: an idealised scenario simulating an SIR-type epidemic outbreak amongst N habitats distributed across a two-dimensional plane; the spread of infection between US cattle farms, illustrating that the FSR method makes continental-scale outbreak forecasting feasible with desktop processing power. The latter model demonstrates which areas of the US are at consistently high risk for cattle-infections, although predictions of epidemic size are highly dependent on assumptions about the tail of the transmission kernel. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Discrete vortex method simulations of aerodynamic admittance in bridge aerodynamics

    DEFF Research Database (Denmark)

    Rasmussen, Johannes Tophøj; Hejlesen, Mads Mølholm; Larsen, Allan

    , and to determine aerodynamic forces and the corresponding flutter limit. A simulation of the three-dimensional bridge responseto turbulent wind is carried out by quasi steady theory by modelling the bridge girder as a line like structure [2], applying the aerodynamic load coefficients found from the current version......The meshless and remeshed Discrete Vortex Method (DVM) has been widely used in academia and by the industry to model two-dimensional flow around bluff bodies. The implementation “DVMFLOW” [1] is used by the bridge design company COWI to determine and visualise the flow field around bridge sections...

  15. Numerical Simulation of Plasma Antenna with FDTD Method

    International Nuclear Information System (INIS)

    Chao, Liang; Yue-Min, Xu; Zhi-Jiang, Wang

    2008-01-01

    We adopt cylindrical-coordinate FDTD algorithm to simulate and analyse a 0.4-m-long column configuration plasma antenna. FDTD method is useful for solving electromagnetic problems, especially when wave characteristics and plasma properties are self-consistently related to each other. Focus on the frequency from 75 MHz to 400 MHz, the input impedance and radiation efficiency of plasma antennas are computed. Numerical results show that, different from copper antenna, the characteristics of plasma antenna vary simultaneously with plasma frequency and collision frequency. The property can be used to construct dynamically reconBgurable antenna. The investigation is meaningful and instructional for the optimization of plasma antenna design

  16. Numerical simulation of plasma antenna with FDTD method

    International Nuclear Information System (INIS)

    Liang Chao; Xu Yuemin; Wang Zhijiang

    2008-01-01

    We adopt cylindrical-coordinate FDTD algorithm to simulate and analyse a 0.4-m-long column configuration plasma antenna. FDTD method is useful for solving electromagnetic problems, especially when wave characteristics and plasma properties are self-consistently related to each other. Focus on the frequency from 75 MHz to 400 MHz, the input impedance and radiation efficiency of plasma antennas are computed. Numerical results show that, different from copper antenna, the characteristics of plasma antenna vary simultaneously with plasma frequency and collision frequency. The property can be used to construct dynamically reconfigurable antenna. The investigation is meaningful and instructional for the optimization of plasma antenna design. (authors)

  17. Assessment of Robotic Patient Simulators for Training in Manual Physical Therapy Examination Techniques

    Science.gov (United States)

    Ishikawa, Shun; Okamoto, Shogo; Isogai, Kaoru; Akiyama, Yasuhiro; Yanagihara, Naomi; Yamada, Yoji

    2015-01-01

    Robots that simulate patients suffering from joint resistance caused by biomechanical and neural impairments are used to aid the training of physical therapists in manual examination techniques. However, there are few methods for assessing such robots. This article proposes two types of assessment measures based on typical judgments of clinicians. One of the measures involves the evaluation of how well the simulator presents different severities of a specified disease. Experienced clinicians were requested to rate the simulated symptoms in terms of severity, and the consistency of their ratings was used as a performance measure. The other measure involves the evaluation of how well the simulator presents different types of symptoms. In this case, the clinicians were requested to classify the simulated resistances in terms of symptom type, and the average ratios of their answers were used as performance measures. For both types of assessment measures, a higher index implied higher agreement among the experienced clinicians that subjectively assessed the symptoms based on typical symptom features. We applied these two assessment methods to a patient knee robot and achieved positive appraisals. The assessment measures have potential for use in comparing several patient simulators for training physical therapists, rather than as absolute indices for developing a standard. PMID:25923719

  18. Assessment of robotic patient simulators for training in manual physical therapy examination techniques.

    Directory of Open Access Journals (Sweden)

    Shun Ishikawa

    Full Text Available Robots that simulate patients suffering from joint resistance caused by biomechanical and neural impairments are used to aid the training of physical therapists in manual examination techniques. However, there are few methods for assessing such robots. This article proposes two types of assessment measures based on typical judgments of clinicians. One of the measures involves the evaluation of how well the simulator presents different severities of a specified disease. Experienced clinicians were requested to rate the simulated symptoms in terms of severity, and the consistency of their ratings was used as a performance measure. The other measure involves the evaluation of how well the simulator presents different types of symptoms. In this case, the clinicians were requested to classify the simulated resistances in terms of symptom type, and the average ratios of their answers were used as performance measures. For both types of assessment measures, a higher index implied higher agreement among the experienced clinicians that subjectively assessed the symptoms based on typical symptom features. We applied these two assessment methods to a patient knee robot and achieved positive appraisals. The assessment measures have potential for use in comparing several patient simulators for training physical therapists, rather than as absolute indices for developing a standard.

  19. Assessment of robotic patient simulators for training in manual physical therapy examination techniques.

    Science.gov (United States)

    Ishikawa, Shun; Okamoto, Shogo; Isogai, Kaoru; Akiyama, Yasuhiro; Yanagihara, Naomi; Yamada, Yoji

    2015-01-01

    Robots that simulate patients suffering from joint resistance caused by biomechanical and neural impairments are used to aid the training of physical therapists in manual examination techniques. However, there are few methods for assessing such robots. This article proposes two types of assessment measures based on typical judgments of clinicians. One of the measures involves the evaluation of how well the simulator presents different severities of a specified disease. Experienced clinicians were requested to rate the simulated symptoms in terms of severity, and the consistency of their ratings was used as a performance measure. The other measure involves the evaluation of how well the simulator presents different types of symptoms. In this case, the clinicians were requested to classify the simulated resistances in terms of symptom type, and the average ratios of their answers were used as performance measures. For both types of assessment measures, a higher index implied higher agreement among the experienced clinicians that subjectively assessed the symptoms based on typical symptom features. We applied these two assessment methods to a patient knee robot and achieved positive appraisals. The assessment measures have potential for use in comparing several patient simulators for training physical therapists, rather than as absolute indices for developing a standard.

  20. Three-dimensional discrete element method simulation of core disking

    Science.gov (United States)

    Wu, Shunchuan; Wu, Haoyan; Kemeny, John

    2018-04-01

    The phenomenon of core disking is commonly seen in deep drilling of highly stressed regions in the Earth's crust. Given its close relationship with the in situ stress state, the presence and features of core disking can be used to interpret the stresses when traditional in situ stress measuring techniques are not available. The core disking process was simulated in this paper using the three-dimensional discrete element method software PFC3D (particle flow code). In particular, PFC3D is used to examine the evolution of fracture initiation, propagation and coalescence associated with core disking under various stress states. In this paper, four unresolved problems concerning core disking are investigated with a series of numerical simulations. These simulations also provide some verification of existing results by other researchers: (1) Core disking occurs when the maximum principal stress is about 6.5 times the tensile strength. (2) For most stress situations, core disking occurs from the outer surface, except for the thrust faulting stress regime, where the fractures were found to initiate from the inner part. (3) The anisotropy of the two horizontal principal stresses has an effect on the core disking morphology. (4) The thickness of core disk has a positive relationship with radial stress and a negative relationship with axial stresses.

  1. Patient safety and quality of care: How may clinical simulation contribute?

    Directory of Open Access Journals (Sweden)

    Sanne Jensen

    2015-09-01

    Full Text Available The usability of health information technology (IT is increasingly recognized as critically important to the development of systems that ensure patient safety and quality of care. The substantial complexity of organizations, work practice and physical environments within the healthcare sector influences the development and application of health IT. When health IT is introduced in local clinical work practices, potential patient safety hazards and insufficient support of work practices need to be examined. Qualitative methods, such as clinical simulation, may be used to evaluate new technology in correlation with the clinical context and to study the interaction between users, technology and work practice. Compared with the “classic” methods, such as heuristic inspection and usability testing, clinical simulation takes the clinical context into account. Clinical simulation can be useful in many processes in the human-centred design cycle. In the requirement specification, clinical simulation can be useful to analyze user requirements and work practice as well to evaluate requirements. In the design of health IT, clinical simulation can be used to evaluate clinical information systems and serve as common ground to help to achieve a shared understanding between various communities of practice. In a public procurement process, a clinical simulation-based assessment can help give insight into different solutions and how they support work practice. Before organizational implementation, clinical simulation is a very suitable means, by which to assess an application in connection with work practice.

  2. Simulation of ecological processes using response functions method

    International Nuclear Information System (INIS)

    Malkina-Pykh, I.G.; Pykh, Yu. A.

    1998-01-01

    The article describes further development and applications of the already well-known response functions method (MRF). The method is used as a basis for the development of mathematical models of a wide set of ecological processes. The model of radioactive contamination of the ecosystems is chosen as an example. The mathematical model was elaborated for the description of 90 Sr dynamics in the elementary ecosystems of various geographical zones. The model includes the blocks corresponding with the main units of any elementary ecosystem: lower atmosphere, soil, vegetation, surface water. Parameters' evaluation was provided on a wide set of experimental data. A set of computer simulations was done on the model to prove the possibility of the model's use for ecological forecasting

  3. Evaluating the practice of Iranian community pharmacists regarding oral contraceptive pills using simulated patients.

    Science.gov (United States)

    Foroutan, Nazanin; Dabaghzadeh, Fatemeh

    2016-01-01

    As oral contraceptive pills are available over the counter in pharmacies, pharmacists are professionally responsible for checking and informing patients about every aspect of taking these drugs. Simulated patient method is a new and robust way to evaluate professional performance of pharmacists. The aim of the present study was to evaluate the pharmacy practice of Iranian pharmacists regarding over-the-counter use of oral contraceptive pills using simulated patient method. Simulated patients visited pharmacy with a prescription containing ciprofloxacin and asked for oral contraceptive pills. The pharmacist was expected to ask important questions for using these drugs and to inform the patient about them properly. Moreover, the Pharmacists should advise patients in regard to the possible interaction. Ninety four pharmacists participated in this study. In 24 (25.3%) visits, the liable pharmacist was not present at the time of purchase. Furthermore, In 13 (18.57 %) visits by the simulated patients, the liable pharmacists did not pay any attention to the simulated patients even when they asked for consultation. Twenty nine (41.43%) pharmacists did not ask any question during dispensing. Nausea was the most frequent described side effect by pharmacists (27 (38.57%)). Yet important adverse effects of oral contraceptive pills were not mentioned by the pharmacists except for few ones. Only twelve (17.14%) pharmacists mentioned the possible interaction. There was a significant relation between the pharmacists' gender and detection of possible interaction (p value= 0.048). The quality of the pharmacists' consultations regarding the over the counter use of oral contraceptive pills was not satisfactory and required improvement.

  4. Simulation of bubble motion under gravity by lattice Boltzmann method

    International Nuclear Information System (INIS)

    Takada, Naoki; Misawa, Masaki; Tomiyama, Akio; Hosokawa, Shigeo

    2001-01-01

    We describe the numerical simulation results of bubble motion under gravity by the lattice Boltzmann method (LBM), which assumes that a fluid consists of mesoscopic fluid particles repeating collision and translation and a multiphase interface is reproduced in a self-organizing way by repulsive interaction between different kinds of particles. The purposes in this study are to examine the applicability of LBM to the numerical analysis of bubble motions, and to develop a three-dimensional version of the binary fluid model that introduces a free energy function. We included the buoyancy terms due to the density difference in the lattice Boltzmann equations, and simulated single-and two-bubble motions, setting flow conditions according to the Eoetvoes and Morton numbers. The two-dimensional results by LBM agree with those by the Volume of Fluid method based on the Navier-Stokes equations. The three-dimensional model possesses the surface tension satisfying the Laplace's law, and reproduces the motion of single bubble and the two-bubble interaction of their approach and coalescence in circular tube. There results prove that the buoyancy terms and the 3D model proposed here are suitable, and that LBM is useful for the numerical analysis of bubble motion under gravity. (author)

  5. Research methods of simulate digital compensators and autonomous control systems

    Directory of Open Access Journals (Sweden)

    V. S. Kudryashov

    2016-01-01

    Full Text Available The peculiarity of the present stage of development of the production is the need to control and regulate a large number of process parameters, the mutual influence on each other that when using single-circuit systems significantly reduces the quality of the transition process, resulting in significant costs of raw materials and energy, reduce the quality of the products. Using a stand-alone digital control system eliminates the correlation of technological parameters, to give the system the desired dynamic and static properties, improve the quality of regulation. However, the complexity of the configuration and implementation of procedures (modeling compensators autonomous systems of this type, associated with the need to perform a significant amount of complex analytic transformation significantly limit the scope of their application. In this regard, the approach based on the decompo sition proposed methods of calculation and simulation (realization, consisting in submitting elements autonomous control part digital control system in a series parallel connection. The above theoretical study carried out in a general way for any dimension systems. The results of computational experiments, obtained during the simulation of the four autonomous control systems, comparative analysis and conclusions on the effectiveness of the use of each of the methods. The results obtained can be used in the development of multi-dimensional process control systems.

  6. Embedding a Virtual Patient Simulator in an Interactive Surgical lecture.

    Science.gov (United States)

    Kleinert, Robert; Plum, Patrick; Heiermann, Nadine; Wahba, Roger; Chang, De-Huan; Hölscher, Arnulf H; Stippel, Dirk L

    2016-01-01

    Lectures are traditionally used for teaching declarative knowledge. One established tool for clinical education is the demonstration of a real patient. The use of real patients in the daily clinical environment is increasingly difficult. The use of a virtual patient simulator (VPS) can potentially circumvent these problems. Unlimited availability and the opportunity of an electronic feedback system could possibly enrich traditional lectures by enabling more interactivity that meets the expectations of the current student generation. As students face the consequences of their own decisions they take a more active role in the lecture. VPS links declarative knowledge with visual perception that is known to influence students' motivation. Until now, there have been no reports covering the usage and validation of interactive VPS for supporting traditional lectures. In this study, we (1) described the development of a custom-made three-dimensional (3D) VPS for supporting the traditional lecture and (2) performed a feasibility study including an initial assessment of this novel educational concept. Conceptualization included definition of curricular content, technical realization and validation. A custom-made simulator was validated with 68 students. The degree of student acceptance was evaluated. Furthermore, the effect on knowledge gain was determined by testing prelecture and postlecture performance. A custom-made simulator prototype that displays a 3D virtual clinic environment was developed and linked to a PowerPoint presentation. Students were able to connect to the simulator via electronic devices (smartphones and tablets) and to control the simulator via majority vote. The simulator was used in 6 lectures and validated in 2 lectures with 68 students each. Student acceptance and their opinion about effectiveness and applicability were determined. Students showed a high level of motivation when using the simulator as most of them had fun using it. Effect on

  7. Determination of electron clinical spectra from percentage depth dose (PDD) curves by classical simulated annealing method

    International Nuclear Information System (INIS)

    Visbal, Jorge H. Wilches; Costa, Alessandro M.

    2016-01-01

    Percentage depth dose of electron beams represents an important item of data in radiation therapy treatment since it describes the dosimetric properties of these. Using an accurate transport theory, or the Monte Carlo method, has been shown obvious differences between the dose distribution of electron beams of a clinical accelerator in a water simulator object and the dose distribution of monoenergetic electrons of nominal energy of the clinical accelerator in water. In radiotherapy, the electron spectra should be considered to improve the accuracy of dose calculation since the shape of PDP curve depends of way how radiation particles deposit their energy in patient/phantom, that is, the spectrum. Exist three principal approaches to obtain electron energy spectra from central PDP: Monte Carlo Method, Direct Measurement and Inverse Reconstruction. In this work it will be presented the Simulated Annealing method as a practical, reliable and simple approach of inverse reconstruction as being an optimal alternative to other options. (author)

  8. High accuracy mantle convection simulation through modern numerical methods

    KAUST Repository

    Kronbichler, Martin

    2012-08-21

    Numerical simulation of the processes in the Earth\\'s mantle is a key piece in understanding its dynamics, composition, history and interaction with the lithosphere and the Earth\\'s core. However, doing so presents many practical difficulties related to the numerical methods that can accurately represent these processes at relevant scales. This paper presents an overview of the state of the art in algorithms for high-Rayleigh number flows such as those in the Earth\\'s mantle, and discusses their implementation in the Open Source code Aspect (Advanced Solver for Problems in Earth\\'s ConvecTion). Specifically, we show how an interconnected set of methods for adaptive mesh refinement (AMR), higher order spatial and temporal discretizations, advection stabilization and efficient linear solvers can provide high accuracy at a numerical cost unachievable with traditional methods, and how these methods can be designed in a way so that they scale to large numbers of processors on compute clusters. Aspect relies on the numerical software packages deal.II and Trilinos, enabling us to focus on high level code and keeping our implementation compact. We present results from validation tests using widely used benchmarks for our code, as well as scaling results from parallel runs. © 2012 The Authors Geophysical Journal International © 2012 RAS.

  9. Simulating clinical trial visits yields patient insights into study design and recruitment

    Directory of Open Access Journals (Sweden)

    Lim SS

    2017-07-01

    Full Text Available S Sam Lim,1 Alan J Kivitz,2 Doug McKinnell,3 M Edward Pierson,4 Faye S O’Brien4 1Division of Rheumatology, Department of Medicine, Emory University, Atlanta, GA, USA; 2Altoona Center for Clinical Research, Altoona, PA, USA; 3Deloitte Life Sciences Advisory, Basel, Switzerland; 4Clinical Operations, Global Medicines Development, AstraZeneca, Gaithersburg, MD, USA Purpose: We elicited patient experiences from clinical trial simulations to aid in future trial development and to improve patient recruitment and retention.Patients and methods: Two simulations of draft Phase II and Phase III anifrolumab studies for systemic lupus erythematosus (SLE/lupus nephritis (LN were performed involving African-American patients from Grady Hospital, an indigent care hospital in Atlanta, GA, USA, and white patients from Altoona Arthritis and Osteoporosis Center in Altoona, PA, USA. The clinical trial simulation included an informed consent procedure, a mock screening visit, a mock dosing visit, and a debriefing period for patients and staff. Patients and staff were interviewed to obtain sentiments and perceptions related to the simulated visits.Results: The Atlanta study involved 6 African-American patients (5 female aged 27–60 years with moderate to severe SLE/LN. The Altoona study involved 12 white females aged 32–75 years with mild to moderate SLE/LN. Patient experiences had an impact on four patient-centric care domains: 1 information, communication, and education; 2 responsiveness to needs; 3 access to care; and 4 coordination of care; and continuity and transition. Patients in both studies desired background material, knowledgeable staff, family and friend support, personal results, comfortable settings, shorter wait times, and greater scheduling flexibility. Compared with the Altoona study patients, Atlanta study patients reported greater preferences for information from the Internet, need for strong community and online support, difficulties in

  10. A survey of modelling methods for high-fidelity wind farm simulations using large eddy simulation

    DEFF Research Database (Denmark)

    Breton, Simon-Philippe; Sumner, J.; Sørensen, Jens Nørkær

    2017-01-01

    surveys the most common schemes available to model the rotor, atmospheric conditions and terrain effects within current state-of-the-art LES codes, of which an overview is provided. A summary of the experimental research data available for validation of LES codes within the context of single and multiple......Large eddy simulations (LES) of wind farms have the capability to provide valuable and detailed information about the dynamics of wind turbine wakes. For this reason, their use within the wind energy research community is on the rise, spurring the development of new models and methods. This review...

  11. A hybrid multiscale kinetic Monte Carlo method for simulation of copper electrodeposition

    International Nuclear Information System (INIS)

    Zheng Zheming; Stephens, Ryan M.; Braatz, Richard D.; Alkire, Richard C.; Petzold, Linda R.

    2008-01-01

    A hybrid multiscale kinetic Monte Carlo (HMKMC) method for speeding up the simulation of copper electrodeposition is presented. The fast diffusion events are simulated deterministically with a heterogeneous diffusion model which considers site-blocking effects of additives. Chemical reactions are simulated by an accelerated (tau-leaping) method for discrete stochastic simulation which adaptively selects exact discrete stochastic simulation for the appropriate reaction whenever that is necessary. The HMKMC method is seen to be accurate and highly efficient

  12. A calculation method for RF couplers design based on numerical simulation by microwave studio

    International Nuclear Information System (INIS)

    Wang Rong; Pei Yuanji; Jin Kai

    2006-01-01

    A numerical simulation method for coupler design is proposed. It is based on the matching procedure for the 2π/3 structure given by Dr. R.L. Kyhl. Microwave Studio EigenMode Solver is used for such numerical simulation. the simulation for a coupler has been finished with this method and the simulation data are compared with experimental measurements. The results show that this numerical simulation method is feasible for coupler design. (authors)

  13. A simulation framework for mapping risks in clinical processes: the case of in-patient transfers.

    Science.gov (United States)

    Dunn, Adam G; Ong, Mei-Sing; Westbrook, Johanna I; Magrabi, Farah; Coiera, Enrico; Wobcke, Wayne

    2011-05-01

    To model how individual violations in routine clinical processes cumulatively contribute to the risk of adverse events in hospital using an agent-based simulation framework. An agent-based simulation was designed to model the cascade of common violations that contribute to the risk of adverse events in routine clinical processes. Clinicians and the information systems that support them were represented as a group of interacting agents using data from direct observations. The model was calibrated using data from 101 patient transfers observed in a hospital and results were validated for one of two scenarios (a misidentification scenario and an infection control scenario). Repeated simulations using the calibrated model were undertaken to create a distribution of possible process outcomes. The likelihood of end-of-chain risk is the main outcome measure, reported for each of the two scenarios. The simulations demonstrate end-of-chain risks of 8% and 24% for the misidentification and infection control scenarios, respectively. Over 95% of the simulations in both scenarios are unique, indicating that the in-patient transfer process diverges from prescribed work practices in a variety of ways. The simulation allowed us to model the risk of adverse events in a clinical process, by generating the variety of possible work subject to violations, a novel prospective risk analysis method. The in-patient transfer process has a high proportion of unique trajectories, implying that risk mitigation may benefit from focusing on reducing complexity rather than augmenting the process with further rule-based protocols.

  14. Fluid Structure Interaction simulation of heart prosthesis in patient-specific left-ventricle/aorta anatomies

    Science.gov (United States)

    Le, Trung; Borazjani, Iman; Sotiropoulos, Fotis

    2009-11-01

    In order to test and optimize heart valve prosthesis and enable virtual implantation of other biomedical devices it is essential to develop and validate high-resolution FSI-CFD codes for carrying out simulations in patient-specific geometries. We have developed a powerful numerical methodology for carrying out FSI simulations of cardiovascular flows based on the CURVIB approach (Borazjani, L. Ge, and F. Sotiropoulos, Journal of Computational physics, vol. 227, pp. 7587-7620 2008). We have extended our FSI method to overset grids to handle efficiently more complicated geometries e.g. simulating an MHV implanted in an anatomically realistic aorta and left-ventricle. A compliant, anatomic left-ventricle is modeled using prescribed motion in one domain. The mechanical heart valve is placed inside the second domain i.e. the body-fitted curvilinear mesh of the anatomic aorta. The simulations of an MHV with a left-ventricle model underscore the importance of inflow conditions and ventricular compliance for such simulations and demonstrate the potential of our method as a powerful tool for patient-specific simulations.

  15. TH-CD-207A-08: Simulated Real-Time Image Guidance for Lung SBRT Patients Using Scatter Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Redler, G; Cifter, G; Templeton, A; Lee, C; Bernard, D; Liao, Y; Zhen, H; Turian, J; Chu, J [Rush University Medical Center, Chicago, IL (United States)

    2016-06-15

    Purpose: To develop a comprehensive Monte Carlo-based model for the acquisition of scatter images of patient anatomy in real-time, during lung SBRT treatment. Methods: During SBRT treatment, images of patient anatomy can be acquired from scattered radiation. To rigorously examine the utility of scatter images for image guidance, a model is developed using MCNP code to simulate scatter images of phantoms and lung cancer patients. The model is validated by comparing experimental and simulated images of phantoms of different complexity. The differentiation between tissue types is investigated by imaging objects of known compositions (water, lung, and bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is used to investigate image noise properties for various quantities of delivered radiation (monitor units(MU)). Patient scatter images are simulated using the validated simulation model. 4DCT patient data is converted to an MCNP input geometry accounting for different tissue composition and densities. Lung tumor phantom images acquired with decreasing imaging time (decreasing MU) are used to model the expected noise amplitude in patient scatter images, producing realistic simulated patient scatter images with varying temporal resolution. Results: Image intensity in simulated and experimental scatter images of tissue equivalent objects (water, lung, bone) match within the uncertainty (∼3%). Lung tumor phantom images agree as well. Specifically, tumor-to-lung contrast matches within the uncertainty. The addition of random noise approximating quantum noise in experimental images to simulated patient images shows that scatter images of lung tumors can provide images in as fast as 0.5 seconds with CNR∼2.7. Conclusions: A scatter imaging simulation model is developed and validated using experimental phantom scatter images. Following validation, lung cancer patient scatter images are simulated. These simulated

  16. TH-CD-207A-08: Simulated Real-Time Image Guidance for Lung SBRT Patients Using Scatter Imaging

    International Nuclear Information System (INIS)

    Redler, G; Cifter, G; Templeton, A; Lee, C; Bernard, D; Liao, Y; Zhen, H; Turian, J; Chu, J

    2016-01-01

    Purpose: To develop a comprehensive Monte Carlo-based model for the acquisition of scatter images of patient anatomy in real-time, during lung SBRT treatment. Methods: During SBRT treatment, images of patient anatomy can be acquired from scattered radiation. To rigorously examine the utility of scatter images for image guidance, a model is developed using MCNP code to simulate scatter images of phantoms and lung cancer patients. The model is validated by comparing experimental and simulated images of phantoms of different complexity. The differentiation between tissue types is investigated by imaging objects of known compositions (water, lung, and bone equivalent). A lung tumor phantom, simulating materials and geometry encountered during lung SBRT treatments, is used to investigate image noise properties for various quantities of delivered radiation (monitor units(MU)). Patient scatter images are simulated using the validated simulation model. 4DCT patient data is converted to an MCNP input geometry accounting for different tissue composition and densities. Lung tumor phantom images acquired with decreasing imaging time (decreasing MU) are used to model the expected noise amplitude in patient scatter images, producing realistic simulated patient scatter images with varying temporal resolution. Results: Image intensity in simulated and experimental scatter images of tissue equivalent objects (water, lung, bone) match within the uncertainty (∼3%). Lung tumor phantom images agree as well. Specifically, tumor-to-lung contrast matches within the uncertainty. The addition of random noise approximating quantum noise in experimental images to simulated patient images shows that scatter images of lung tumors can provide images in as fast as 0.5 seconds with CNR∼2.7. Conclusions: A scatter imaging simulation model is developed and validated using experimental phantom scatter images. Following validation, lung cancer patient scatter images are simulated. These simulated

  17. A multimedia patient simulation for teaching and assessing endodontic diagnosis.

    Science.gov (United States)

    Littlefield, John H; Demps, Elaine L; Keiser, Karl; Chatterjee, Lipika; Yuan, Cheng H; Hargreaves, Kenneth M

    2003-06-01

    Teaching and assessing diagnostic skills are difficult due to relatively small numbers of total clinical experiences and a shortage of clinical faculty. Patient simulations could help teach and assess diagnosis by displaying a well-defined diagnostic task, then providing informative feedback and opportunities for repetition and correction of errors. This report describes the development and initial evaluation of SimEndo I, a multimedia patient simulation program that could be used for teaching or assessing endodontic diagnosis. Students interact with a graphical interface that has four pull-down menus and related submenus. In response to student requests, the program presents patient information. Scoring is based on diagnosis of each case by endodontists. Pilot testing with seventy-four junior dental students identified numerous needed improvements to the user interface program. A multi-school field test of the interface program using three patient cases addressed three research questions: 1) How did the field test students evaluate SimEndo I? Overall mean evaluation was 8.1 on a 0 to 10 scale; 2) How many cases are needed to generate a reproducible diagnostic proficiency score for an individual student using the Rimoldi scoring procedure? Mean diagnostic proficiency scores by case ranged from .27 to .40 on a 0 to 1 scale; five cases would produce a score with a 0.80 reliability coefficient; and 3) Did students accurately diagnose each case? Mean correct diagnosis scores by case ranged from .54 to .78 on a 0 to 1 scale. We conclude that multimedia patient simulations offer a promising alternative for teaching and assessing student diagnostic skills.

  18. Simulation experience enhances physical therapist student confidence in managing a patient in the critical care environment.

    Science.gov (United States)

    Ohtake, Patricia J; Lazarus, Marcilene; Schillo, Rebecca; Rosen, Michael

    2013-02-01

    Rehabilitation of patients in critical care environments improves functional outcomes. This finding has led to increased implementation of intensive care unit (ICU) rehabilitation programs, including early mobility, and an associated increased demand for physical therapists practicing in ICUs. Unfortunately, many physical therapists report being inadequately prepared to work in this high-risk environment. Simulation provides focused, deliberate practice in safe, controlled learning environments and may be a method to initiate academic preparation of physical therapists for ICU practice. The purpose of this study was to examine the effect of participation in simulation-based management of a patient with critical illness in an ICU setting on levels of confidence and satisfaction in physical therapist students. A one-group, pretest-posttest, quasi-experimental design was used. Physical therapist students (N=43) participated in a critical care simulation experience requiring technical (assessing bed mobility and pulmonary status), behavioral (patient and interprofessional communication), and cognitive (recognizing a patient status change and initiating appropriate responses) skill performance. Student confidence and satisfaction were surveyed before and after the simulation experience. Students' confidence in their technical, behavioral, and cognitive skill performance increased from "somewhat confident" to "confident" following the critical care simulation experience. Student satisfaction was highly positive, with strong agreement the simulation experience was valuable, reinforced course content, and was a useful educational tool. Limitations of the study were the small sample from one university and a control group was not included. Incorporating a simulated, interprofessional critical care experience into a required clinical course improved physical therapist student confidence in technical, behavioral, and cognitive performance measures and was associated with high

  19. Adaptive and dynamic meshing methods for numerical simulations

    Science.gov (United States)

    Acikgoz, Nazmiye

    -hoc application of the simulated annealing technique, which improves the likelihood of removing poor elements from the grid. Moreover, a local implementation of the simulated annealing is proposed to reduce the computational cost. Many challenging multi-physics and multi-field problems that are unsteady in nature are characterized by moving boundaries and/or interfaces. When the boundary displacements are large, which typically occurs when implicit time marching procedures are used, degenerate elements are easily formed in the grid such that frequent remeshing is required. To deal with this problem, in the second part of this work, we propose a new r-adaptation methodology. The new technique is valid for both simplicial (e.g., triangular, tet) and non-simplicial (e.g., quadrilateral, hex) deforming grids that undergo large imposed displacements at their boundaries. A two- or three-dimensional grid is deformed using a network of linear springs composed of edge springs and a set of virtual springs. The virtual springs are constructed in such a way as to oppose element collapsing. This is accomplished by confining each vertex to its ball through springs that are attached to the vertex and its projection on the ball entities. The resulting linear problem is solved using a preconditioned conjugate gradient method. The new method is compared with the classical spring analogy technique in two- and three-dimensional examples, highlighting the performance improvements achieved by the new method. Meshes are an important part of numerical simulations. Depending on the geometry and flow conditions, the most suitable mesh for each particular problem is different. Meshes are usually generated by either using a suitable software package or solving a PDE. In both cases, engineering intuition plays a significant role in deciding where clusterings should take place. In addition, for unsteady problems, the gradients vary for each time step, which requires frequent remeshing during simulations

  20. Applying Simulation Method in Formulation of Gluten-Free Cookies

    Directory of Open Access Journals (Sweden)

    Nikitina Marina

    2017-01-01

    Full Text Available At present time priority direction in the development of new food products its developing of technology products for special purposes. These types of products are gluten-free confectionery products, intended for people with celiac disease. Gluten-free products are in demand among consumers, it needs to expand assortment, and improvement of quality indicators. At this article results of studies on the development of pastry products based on amaranth flour does not contain gluten. Study based on method of simulation recipes gluten-free confectionery functional orientation to optimize their chemical composition. The resulting products will allow to diversify and supplement the necessary nutrients diet for people with gluten intolerance, as well as for those who follow a gluten-free diet.

  1. The Multiscale Material Point Method for Simulating Transient Responses

    Science.gov (United States)

    Chen, Zhen; Su, Yu-Chen; Zhang, Hetao; Jiang, Shan; Sewell, Thomas

    2015-06-01

    To effectively simulate multiscale transient responses such as impact and penetration without invoking master/slave treatment, the multiscale material point method (Multi-MPM) is being developed in which molecular dynamics at nanoscale and dissipative particle dynamics at mesoscale might be concurrently handled within the framework of the original MPM at microscale (continuum level). The proposed numerical scheme for concurrently linking different scales is described in this paper with simple examples for demonstration. It is shown from the preliminary study that the mapping and re-mapping procedure used in the original MPM could coarse-grain the information at fine scale and that the proposed interfacial scheme could provide a smooth link between different scales. Since the original MPM is an extension from computational fluid dynamics to solid dynamics, the proposed Multi-MPM might also become robust for dealing with multiphase interactions involving failure evolution. This work is supported in part by DTRA and NSFC.

  2. Numerical Simulation of Antennas with Improved Integral Equation Method

    International Nuclear Information System (INIS)

    Ma Ji; Fang Guang-You; Lu Wei

    2015-01-01

    Simulating antennas around a conducting object is a challenge task in computational electromagnetism, which is concerned with the behaviour of electromagnetic fields. To analyze this model efficiently, an improved integral equation-fast Fourier transform (IE-FFT) algorithm is presented in this paper. The proposed scheme employs two Cartesian grids with different size and location to enclose the antenna and the other object, respectively. On the one hand, IE-FFT technique is used to store matrix in a sparse form and accelerate the matrix-vector multiplication for each sub-domain independently. On the other hand, the mutual interaction between sub-domains is taken as the additional exciting voltage in each matrix equation. By updating integral equations several times, the whole electromagnetic system can achieve a stable status. Finally, the validity of the presented method is verified through the analysis of typical antennas in the presence of a conducting object. (paper)

  3. Optimized Design of Spacer in Electrodialyzer Using CFD Simulation Method

    Science.gov (United States)

    Jia, Yuxiang; Yan, Chunsheng; Chen, Lijun; Hu, Yangdong

    2018-06-01

    In this study, the effects of length-width ratio and diversion trench of the spacer on the fluid flow behavior in an electrodialyzer have been investigated through CFD simulation method. The relevant information, including the pressure drop, velocity vector distribution and shear stress distribution, demonstrates the importance of optimized design of the spacer in an electrodialysis process. The results show width of the diversion trench has a great effect on the fluid flow compared with length. Increase of the diversion trench width could strength the fluid flow, but also increase the pressure drop. Secondly, the dead zone of the fluid flow decreases with increase of length-width ratio of the spacer, but the pressure drop increases with the increase of length-width ratio of the spacer. So the appropriate length-width ratio of the space should be moderate.

  4. Study of Flapping Flight Using Discrete Vortex Method Based Simulations

    Science.gov (United States)

    Devranjan, S.; Jalikop, Shreyas V.; Sreenivas, K. R.

    2013-12-01

    In recent times, research in the area of flapping flight has attracted renewed interest with an endeavor to use this mechanism in Micro Air vehicles (MAVs). For a sustained and high-endurance flight, having larger payload carrying capacity we need to identify a simple and efficient flapping-kinematics. In this paper, we have used flow visualizations and Discrete Vortex Method (DVM) based simulations for the study of flapping flight. Our results highlight that simple flapping kinematics with down-stroke period (tD) shorter than the upstroke period (tU) would produce a sustained lift. We have identified optimal asymmetry ratio (Ar = tD/tU), for which flapping-wings will produce maximum lift and find that introducing optimal wing flexibility will further enhances the lift.

  5. Simulation of galvanic corrosion using boundary element method

    International Nuclear Information System (INIS)

    Zaifol Samsu; Muhamad Daud; Siti Radiah Mohd Kamaruddin; Nur Ubaidah Saidin; Abdul Aziz Mohamed; Mohd Saari Ripin; Rusni Rejab; Mohd Shariff Sattar

    2011-01-01

    Boundary element method (BEM) is a numerical technique that used for modeling infinite domain as is the case for galvanic corrosion analysis. The use of boundary element analysis system (BEASY) has allowed cathodic protection (CP) interference to be assessed in terms of the normal current density, which is directly proportional to the corrosion rate. This paper was present the analysis of the galvanic corrosion between Aluminium and Carbon Steel in natural sea water. The result of experimental was validated with computer simulation like BEASY program. Finally, it can conclude that the BEASY software is a very helpful tool for future planning before installing any structure, where it gives the possible CP interference on any nearby unprotected metallic structure. (Author)

  6. An experiment teaching method based on the Optisystem simulation platform

    Science.gov (United States)

    Zhu, Jihua; Xiao, Xuanlu; Luo, Yuan

    2017-08-01

    The experiment teaching of optical communication system is difficult to achieve because of expensive equipment. The Optisystem is optical communication system design software, being able to provide such a simulation platform. According to the characteristic of the OptiSystem, an approach of experiment teaching is put forward in this paper. It includes three gradual levels, the basics, the deeper looks and the practices. Firstly, the basics introduce a brief overview of the technology, then the deeper looks include demoes and example analyses, lastly the practices are going on through the team seminars and comments. A variety of teaching forms are implemented in class. The fact proves that this method can not only make up the laboratory but also motivate the students' learning interest and improve their practical abilities, cooperation abilities and creative spirits. On the whole, it greatly raises the teaching effect.

  7. A Finite Element Method for Simulation of Compressible Cavitating Flows

    Science.gov (United States)

    Shams, Ehsan; Yang, Fan; Zhang, Yu; Sahni, Onkar; Shephard, Mark; Oberai, Assad

    2016-11-01

    This work focuses on a novel approach for finite element simulations of multi-phase flows which involve evolving interface with phase change. Modeling problems, such as cavitation, requires addressing multiple challenges, including compressibility of the vapor phase, interface physics caused by mass, momentum and energy fluxes. We have developed a mathematically consistent and robust computational approach to address these problems. We use stabilized finite element methods on unstructured meshes to solve for the compressible Navier-Stokes equations. Arbitrary Lagrangian-Eulerian formulation is used to handle the interface motions. Our method uses a mesh adaptation strategy to preserve the quality of the volumetric mesh, while the interface mesh moves along with the interface. The interface jump conditions are accurately represented using a discontinuous Galerkin method on the conservation laws. Condensation and evaporation rates at the interface are thermodynamically modeled to determine the interface velocity. We will present initial results on bubble cavitation the behavior of an attached cavitation zone in a separated boundary layer. We acknowledge the support from Army Research Office (ARO) under ARO Grant W911NF-14-1-0301.

  8. Steam generator tube rupture simulation using extended finite element method

    Energy Technology Data Exchange (ETDEWEB)

    Mohanty, Subhasish, E-mail: smohanty@anl.gov; Majumdar, Saurin; Natesan, Ken

    2016-08-15

    Highlights: • Extended finite element method used for modeling the steam generator tube rupture. • Crack propagation is modeled in an arbitrary solution dependent path. • The FE model is used for estimating the rupture pressure of steam generator tubes. • Crack coalescence modeling is also demonstrated. • The method can be used for crack modeling of tubes under severe accident condition. - Abstract: A steam generator (SG) is an important component of any pressurized water reactor. Steam generator tubes represent a primary pressure boundary whose integrity is vital to the safe operation of the reactor. SG tubes may rupture due to propagation of a crack created by mechanisms such as stress corrosion cracking, fatigue, etc. It is thus important to estimate the rupture pressures of cracked tubes for structural integrity evaluation of SGs. The objective of the present paper is to demonstrate the use of extended finite element method capability of commercially available ABAQUS software, to model SG tubes with preexisting flaws and to estimate their rupture pressures. For the purpose, elastic–plastic finite element models were developed for different SG tubes made from Alloy 600 material. The simulation results were compared with experimental results available from the steam generator tube integrity program (SGTIP) sponsored by the United States Nuclear Regulatory Commission (NRC) and conducted at Argonne National Laboratory (ANL). A reasonable correlation was found between extended finite element model results and experimental results.

  9. Precision of a FDTD method to simulate cold magnetized plasmas

    International Nuclear Information System (INIS)

    Pavlenko, I.V.; Melnyk, D.A.; Prokaieva, A.O.; Girka, I.O.

    2014-01-01

    The finite difference time domain (FDTD) method is applied to describe the propagation of the transverse electromagnetic waves through the magnetized plasmas. The numerical dispersion relation is obtained in a cold plasma approximation. The accuracy of the numerical dispersion is calculated as a function of the frequency of the launched wave and time step of the numerical grid. It is shown that the numerical method does not reproduce the analytical results near the plasma resonances for any chosen value of time step if there is not a dissipation mechanism in the system. It means that FDTD method cannot be applied straightforward to simulate the problems where the plasma resonances play a key role (for example, the mode conversion problems). But the accuracy of the numerical scheme can be improved by introducing some artificial damping of the plasma currents. Although part of the wave power is lost in the system in this case but the numerical scheme describes the wave processes in an agreement with analytical predictions.

  10. Steam generator tube rupture simulation using extended finite element method

    International Nuclear Information System (INIS)

    Mohanty, Subhasish; Majumdar, Saurin; Natesan, Ken

    2016-01-01

    Highlights: • Extended finite element method used for modeling the steam generator tube rupture. • Crack propagation is modeled in an arbitrary solution dependent path. • The FE model is used for estimating the rupture pressure of steam generator tubes. • Crack coalescence modeling is also demonstrated. • The method can be used for crack modeling of tubes under severe accident condition. - Abstract: A steam generator (SG) is an important component of any pressurized water reactor. Steam generator tubes represent a primary pressure boundary whose integrity is vital to the safe operation of the reactor. SG tubes may rupture due to propagation of a crack created by mechanisms such as stress corrosion cracking, fatigue, etc. It is thus important to estimate the rupture pressures of cracked tubes for structural integrity evaluation of SGs. The objective of the present paper is to demonstrate the use of extended finite element method capability of commercially available ABAQUS software, to model SG tubes with preexisting flaws and to estimate their rupture pressures. For the purpose, elastic–plastic finite element models were developed for different SG tubes made from Alloy 600 material. The simulation results were compared with experimental results available from the steam generator tube integrity program (SGTIP) sponsored by the United States Nuclear Regulatory Commission (NRC) and conducted at Argonne National Laboratory (ANL). A reasonable correlation was found between extended finite element model results and experimental results.

  11. Using a formative simulated patient exercise for curriculum evaluation

    Directory of Open Access Journals (Sweden)

    Thompson Margaret E

    2004-05-01

    Full Text Available Abstract Background It is not clear that teaching specific history taking, physical examination and patient teaching techniques to medical students results in durable behavioural changes. We used a quasi-experimental design that approximated a randomized double blinded trial to examine whether a Participatory Decision-Making (PDM educational module taught in a clerkship improves performance on a Simulated Patient Exercise (SPE in another clerkship, and how this is influenced by the time between training and assessment. Methods Third year medical students in an internal medicine clerkship were assessed on their use of PDM skills in an SPE conducted in the second week of the clerkship. The rotational structure of the third year clerkships formed a pseudo-randomized design where students had 1 completed the family practice clerkship containing a training module on PDM skills approximately four weeks prior to the SPE, 2 completed the family medicine clerkship and the training module approximately 12 weeks prior to the SPE or 3 had not completed the family medicine clerkship and the PDM training module at the time they were assessed via the SPE. Results Based on limited pilot data there were statistically significant differences between students who received PDM training approximately four weeks prior to the SPE and students who received training approximately 12 weeks prior to the SPE. Students who received training 12 weeks prior to the SPE performed better than those who received training four weeks prior to the SPE. In a second comparison students who received training four weeks prior to the SPE performed better than those who did not receive training but the differences narrowly missed statistical significance (P Conclusion This pilot study demonstrated the feasibility of a methodology for conducting rigorous curricular evaluations using natural experiments based on the structure of clinical rotations. In addition, it provided preliminary data

  12. A Monte Carlo method and finite volume method coupled optical simulation method for parabolic trough solar collectors

    International Nuclear Information System (INIS)

    Liang, Hongbo; Fan, Man; You, Shijun; Zheng, Wandong; Zhang, Huan; Ye, Tianzhen; Zheng, Xuejing

    2017-01-01

    Highlights: •Four optical models for parabolic trough solar collectors were compared in detail. •Characteristics of Monte Carlo Method and Finite Volume Method were discussed. •A novel method was presented combining advantages of different models. •The method was suited to optical analysis of collectors with different geometries. •A new kind of cavity receiver was simulated depending on the novel method. -- Abstract: The PTC (parabolic trough solar collector) is widely used for space heating, heat-driven refrigeration, solar power, etc. The concentrated solar radiation is the only energy source for a PTC, thus its optical performance significantly affects the collector efficiency. In this study, four different optical models were constructed, validated and compared in detail. On this basis, a novel coupled method was presented by combining advantages of these models, which was suited to carry out a mass of optical simulations of collectors with different geometrical parameters rapidly and accurately. Based on these simulation results, the optimal configuration of a collector with highest efficiency can be determined. Thus, this method was useful for collector optimization and design. In the four models, MCM (Monte Carlo Method) and FVM (Finite Volume Method) were used to initialize photons distribution, as well as CPEM (Change Photon Energy Method) and MCM were adopted to describe the process of reflecting, transmitting and absorbing. For simulating reflection, transmission and absorption, CPEM was more efficient than MCM, so it was utilized in the coupled method. For photons distribution initialization, FVM saved running time and computation effort, whereas it needed suitable grid configuration. MCM only required a total number of rays for simulation, whereas it needed higher computing cost and its results fluctuated in multiple runs. In the novel coupled method, the grid configuration for FVM was optimized according to the “true values” from MCM of

  13. Simulation and Verificaiton of Flow in Test Methods

    DEFF Research Database (Denmark)

    Thrane, Lars Nyholm; Szabo, Peter; Geiker, Mette Rica

    2005-01-01

    Simulations and experimental results of L-box and slump flow test of a self-compacting mortar and a self-compacting concrete are compared. The simulations are based on a single fluid approach and assume an ideal Bingham behavior. It is possible to simulate the experimental results of both tests...

  14. An Importance Sampling Simulation Method for Bayesian Decision Feedback Equalizers

    OpenAIRE

    Chen, S.; Hanzo, L.

    2000-01-01

    An importance sampling (IS) simulation technique is presented for evaluating the lower-bound bit error rate (BER) of the Bayesian decision feedback equalizer (DFE) under the assumption of correct decisions being fed back. A design procedure is developed, which chooses appropriate bias vectors for the simulation density to ensure asymptotic efficiency of the IS simulation.

  15. Working as simulated patient has effects on real patient life – Preliminary insights from a qualitative study

    Directory of Open Access Journals (Sweden)

    Simmenroth-Nayda, Anne

    2016-05-01

    Full Text Available Background: Persons who simulate patients during medical education understand the routines and the underlying script of medical consultations better. We aimed to explore how simulated patients (SPs integrated this new understanding into their daily life, how this work affected their private life as patients, and what we can learn from these changes for concepts of empowerment.Design, setting, and participants: A qualitative interview study. All SPs of Göttingen medical school who had been working longer than three semesters (n=14 were invited and agreed to take part in an open interview about their daily experience with real doctors. Documentary method was used to identify the main issues. Several cases were chosen according to maximum contrast and analysed by in-depth analysis to provide vivid examples of how simulations may affect the real life of the SPs as patients.Results: Our analysis revealed three main changes in the behaviour of SPs as real patients. They were more attentive, had a better understanding of the circumstances under which doctors work, and acted more self-confidently. From the selected cases it became apparent that working as a SP may lead to a constant and significant decrease of fear of hospitals and medical procedures or, in other cases, may enable the SPs to develop new abilities for giving feedback, questioning procedures, and explanations for real doctors.Conclusion: working as a simulated patient seems to be well-suited to understand own progression of diseases, to increase self-responsibility and to a confident attitude as patient.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    BACKGROUND & AIMS: Minimal hepatic encephalopathy (MHE) has been linked to higher real-life rates of automobile crashes and poor performance in driving simulation studies, but the link between driving simulator performance and real-life automobile crashes has not been clearly established. Further......, not all patients with MHE are unsafe drivers, but it is unclear how to distinguish them from unsafe drivers. We investigated the link between performance on driving simulators and real-life automobile accidents and traffic violations. We also aimed to identify features of unsafe drivers with cirrhosis...... and evaluated changes in simulated driving skills and MHE status after 1 year. METHODS: We performed a study of outpatients with cirrhosis (n=205; median 55 years old; median model for end-stage liver disease score, 9.5; none with overt hepatic encephalopathy or alcohol or illicit drug use within previous 6...

  17. Using soft systems methodology to develop a simulation of out-patient services.

    Science.gov (United States)

    Lehaney, B; Paul, R J

    1994-10-01

    Discrete event simulation is an approach to modelling a system in the form of a set of mathematical equations and logical relationships, usually used for complex problems, which are difficult to address by using analytical or numerical methods. Managing out-patient services is such a problem. However, simulation is not in itself a systemic approach, in that it provides no methodology by which system boundaries and system activities may be identified. The investigation considers the use of soft systems methodology as an aid to drawing system boundaries and identifying system activities, for the purpose of simulating the outpatients' department at a local hospital. The long term aims are to examine the effects that the participative nature of soft systems methodology has on the acceptability of the simulation model, and to provide analysts and managers with a process that may assist in planning strategies for health care.

  18. Numerical simulation for cracks detection using the finite elements method

    Directory of Open Access Journals (Sweden)

    S Bennoud

    2016-09-01

    Full Text Available The means of detection must ensure controls either during initial construction, or at the time of exploitation of all parts. The Non destructive testing (NDT gathers the most widespread methods for detecting defects of a part or review the integrity of a structure. In the areas of advanced industry (aeronautics, aerospace, nuclear …, assessing the damage of materials is a key point to control durability and reliability of parts and materials in service. In this context, it is necessary to quantify the damage and identify the different mechanisms responsible for the progress of this damage. It is therefore essential to characterize materials and identify the most sensitive indicators attached to damage to prevent their destruction and use them optimally. In this work, simulation by finite elements method is realized with aim to calculate the electromagnetic energy of interaction: probe and piece (with/without defect. From calculated energy, we deduce the real and imaginary components of the impedance which enables to determine the characteristic parameters of a crack in various metallic parts.

  19. Application of the maximum entropy method to dynamical fermion simulations

    Science.gov (United States)

    Clowser, Jonathan

    This thesis presents results for spectral functions extracted from imaginary-time correlation functions obtained from Monte Carlo simulations using the Maximum Entropy Method (MEM). The advantages this method are (i) no a priori assumptions or parametrisations of the spectral function are needed, (ii) a unique solution exists and (iii) the statistical significance of the resulting image can be quantitatively analysed. The Gross Neveu model in d = 3 spacetime dimensions (GNM3) is a particularly interesting model to study with the MEM because at T = 0 it has a broken phase with a rich spectrum of mesonic bound states and a symmetric phase where there are resonances. Results for the elementary fermion, the Goldstone boson (pion), the sigma, the massive pseudoscalar meson and the symmetric phase resonances are presented. UKQCD Nf = 2 dynamical QCD data is also studied with MEM. Results are compared to those found from the quenched approximation, where the effects of quark loops in the QCD vacuum are neglected, to search for sea-quark effects in the extracted spectral functions. Information has been extract from the difficult axial spatial and scalar as well as the pseudoscalar, vector and axial temporal channels. An estimate for the non-singlet scalar mass in the chiral limit is given which is in agreement with the experimental value of Mao = 985 MeV.

  20. Methods employed to speed up Cathare for simulation uses

    International Nuclear Information System (INIS)

    Agator, J.M.

    1992-01-01

    This paper describes the main methods used to speed up the french advanced thermal-hydraulic computer code CATHARE and build a speedy version, called CATHARE-SIMU, adapted to real time calculations and simulation environment. Since CATHARE-SIMU, like CATHARE, uses a numerical scheme based on a fully implicit Newton's iterative method, and therefore with a variable time step, two ways have been explored to reduce the computing time: avoidance of short time steps, and so minimization of the number of iterations per time step, reduction of the computing time needed for an iteration. CATHARE-SIMU uses the same physical laws and correlations as in CATHARE with only some minor simplifications. This was considered the only way to be sure to maintain the level of physical relevance of CATHARE. Finally it is indicated that the validation programme of CATHARE-SIMU includes a set of 33 transient calculations, referring either to CATHARE for two-phase transients, or to measurements on real plants for operational transients

  1. Hybrid Methods for Muon Accelerator Simulations with Ionization Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Kunz, Josiah [Anderson U.; Snopok, Pavel [Fermilab; Berz, Martin [Michigan State U.; Makino, Kyoko [Michigan State U.

    2018-03-28

    Muon ionization cooling involves passing particles through solid or liquid absorbers. Careful simulations are required to design muon cooling channels. New features have been developed for inclusion in the transfer map code COSY Infinity to follow the distribution of charged particles through matter. To study the passage of muons through material, the transfer map approach alone is not sufficient. The interplay of beam optics and atomic processes must be studied by a hybrid transfer map--Monte-Carlo approach in which transfer map methods describe the deterministic behavior of the particles, and Monte-Carlo methods are used to provide corrections accounting for the stochastic nature of scattering and straggling of particles. The advantage of the new approach is that the vast majority of the dynamics are represented by fast application of the high-order transfer map of an entire element and accumulated stochastic effects. The gains in speed are expected to simplify the optimization of cooling channels which is usually computationally demanding. Progress on the development of the required algorithms and their application to modeling muon ionization cooling channels is reported.

  2. Evaluation of the airway of the SimMan full-scale patient simulator

    DEFF Research Database (Denmark)

    Hesselfeldt, R; Kristensen, M S; Rasmussen, L S

    2005-01-01

    SimMan is a full-scale patient simulator, capable of simulating normal and pathological airways. The performance of SimMan has never been critically evaluated.......SimMan is a full-scale patient simulator, capable of simulating normal and pathological airways. The performance of SimMan has never been critically evaluated....

  3. [Innovation in healthcare processes and patient safety using clinical simulation].

    Science.gov (United States)

    Rojo, E; Maestre, J M; Díaz-Mendi, A R; Ansorena, L; Del Moral, I

    2016-01-01

    Many excellent ideas are never implemented or generalised by healthcare organisations. There are two related paradigms: thinking that individuals primarily change through accumulating knowledge, and believing that the dissemination of that knowledge within the organisation is the key element to facilitate change. As an alternative, a description and evaluation of a simulation-based inter-professional team training program conducted in a Regional Health Service to promote and facilitate change is presented. The Department of Continuing Education completed the needs assessment using the proposals presented by clinical units and management. Skills and behaviors that could be learned using simulation were selected, and all personnel from the units participating were included. Experiential learning principles based on clinical simulation and debriefing, were used for the instructional design. The Kirkpatrick model was used to evaluate the program. Objectives included: a) decision-making and teamwork skills training in high prevalence diseases with a high rate of preventable complications; b) care processes reorganisation to improve efficiency, while maintaining patient safety; and, c) implementation of new complex techniques with a long learning curve, and high preventable complications rate. Thirty clinical units organised 39 training programs in the 3 public hospitals, and primary care of the Regional Health Service during 2013-2014. Over 1,559 healthcare professionals participated, including nursing assistants, nurses and physicians. Simulation in healthcare to train inter-professional teams can promote and facilitate change in patient care, and organisational re-engineering. Copyright © 2016 SECA. Publicado por Elsevier España, S.L.U. All rights reserved.

  4. Gradient augmented level set method for phase change simulations

    Science.gov (United States)

    Anumolu, Lakshman; Trujillo, Mario F.

    2018-01-01

    A numerical method for the simulation of two-phase flow with phase change based on the Gradient-Augmented-Level-set (GALS) strategy is presented. Sharp capturing of the vaporization process is enabled by: i) identification of the vapor-liquid interface, Γ (t), at the subgrid level, ii) discontinuous treatment of thermal physical properties (except for μ), and iii) enforcement of mass, momentum, and energy jump conditions, where the gradients of the dependent variables are obtained at Γ (t) and are consistent with their analytical expression, i.e. no local averaging is applied. Treatment of the jump in velocity and pressure at Γ (t) is achieved using the Ghost Fluid Method. The solution of the energy equation employs the sub-grid knowledge of Γ (t) to discretize the temperature Laplacian using second-order one-sided differences, i.e. the numerical stencil completely resides within each respective phase. To carefully evaluate the benefits or disadvantages of the GALS approach, the standard level set method is implemented and compared against the GALS predictions. The results show the expected trend that interface identification and transport are predicted noticeably better with GALS over the standard level set. This benefit carries over to the prediction of the Laplacian and temperature gradients in the neighborhood of the interface, which are directly linked to the calculation of the vaporization rate. However, when combining the calculation of interface transport and reinitialization with two-phase momentum and energy, the benefits of GALS are to some extent neutralized, and the causes for this behavior are identified and analyzed. Overall the additional computational costs associated with GALS are almost the same as those using the standard level set technique.

  5. Simulation of neutral gas flow in a tokamak divertor using the Direct Simulation Monte Carlo method

    International Nuclear Information System (INIS)

    Gleason-González, Cristian; Varoutis, Stylianos; Hauer, Volker; Day, Christian

    2014-01-01

    Highlights: • Subdivertor gas flows calculations in tokamaks by coupling the B2-EIRENE and DSMC method. • The results include pressure, temperature, bulk velocity and particle fluxes in the subdivertor. • Gas recirculation effect towards the plasma chamber through the vertical targets is found. • Comparison between DSMC and the ITERVAC code reveals a very good agreement. - Abstract: This paper presents a new innovative scientific and engineering approach for describing sub-divertor gas flows of fusion devices by coupling the B2-EIRENE (SOLPS) code and the Direct Simulation Monte Carlo (DSMC) method. The present study exemplifies this with a computational investigation of neutral gas flow in the ITER's sub-divertor region. The numerical results include the flow fields and contours of the overall quantities of practical interest such as the pressure, the temperature and the bulk velocity assuming helium as model gas. Moreover, the study unravels the gas recirculation effect located behind the vertical targets, viz. neutral particles flowing towards the plasma chamber. Comparison between calculations performed by the DSMC method and the ITERVAC code reveals a very good agreement along the main sub-divertor ducts

  6. Asthma management simulation for children: translating theory, methods, and strategies to effect behavior change.

    Science.gov (United States)

    Shegog, Ross; Bartholomew, L Kay; Gold, Robert S; Pierrel, Elaine; Parcel, Guy S; Sockrider, Marianna M; Czyzewski, Danita I; Fernandez, Maria E; Berlin, Nina J; Abramson, Stuart

    2006-01-01

    Translating behavioral theories, models, and strategies to guide the development and structure of computer-based health applications is well recognized, although a continued challenge for program developers. A stepped approach to translate behavioral theory in the design of simulations to teach chronic disease management to children is described. This includes the translation steps to: 1) define target behaviors and their determinants, 2) identify theoretical methods to optimize behavioral change, and 3) choose educational strategies to effectively apply these methods and combine these into a cohesive computer-based simulation for health education. Asthma is used to exemplify a chronic health management problem and a computer-based asthma management simulation (Watch, Discover, Think and Act) that has been evaluated and shown to effect asthma self-management in children is used to exemplify the application of theory to practice. Impact and outcome evaluation studies have indicated the effectiveness of these steps in providing increased rigor and accountability, suggesting their utility for educators and developers seeking to apply simulations to enhance self-management behaviors in patients.

  7. LDRD Final Report: Adaptive Methods for Laser Plasma Simulation

    International Nuclear Information System (INIS)

    Dorr, M R; Garaizar, F X; Hittinger, J A

    2003-01-01

    The goal of this project was to investigate the utility of parallel adaptive mesh refinement (AMR) in the simulation of laser plasma interaction (LPI). The scope of work included the development of new numerical methods and parallel implementation strategies. The primary deliverables were (1) parallel adaptive algorithms to solve a system of equations combining plasma fluid and light propagation models, (2) a research code implementing these algorithms, and (3) an analysis of the performance of parallel AMR on LPI problems. The project accomplished these objectives. New algorithms were developed for the solution of a system of equations describing LPI. These algorithms were implemented in a new research code named ALPS (Adaptive Laser Plasma Simulator) that was used to test the effectiveness of the AMR algorithms on the Laboratory's large-scale computer platforms. The details of the algorithm and the results of the numerical tests were documented in an article published in the Journal of Computational Physics [2]. A principal conclusion of this investigation is that AMR is most effective for LPI systems that are ''hydrodynamically large'', i.e., problems requiring the simulation of a large plasma volume relative to the volume occupied by the laser light. Since the plasma-only regions require less resolution than the laser light, AMR enables the use of efficient meshes for such problems. In contrast, AMR is less effective for, say, a single highly filamented beam propagating through a phase plate, since the resulting speckle pattern may be too dense to adequately separate scales with a locally refined mesh. Ultimately, the gain to be expected from the use of AMR is highly problem-dependent. One class of problems investigated in this project involved a pair of laser beams crossing in a plasma flow. Under certain conditions, energy can be transferred from one beam to the other via a resonant interaction with an ion acoustic wave in the crossing region. AMR provides an

  8. [Tropical pyomyositis simulating septic arthritis in AIDS patients. Two cases].

    Science.gov (United States)

    Abouzahir, A; Bouchama, R; Azennag, M; Garcin, J M

    2004-01-01

    Tropical pyomyositis (TP) is an acute bacterial infection of skeletal muscles characterized by rapid formation of abscesses. Since the beginning of the AIDS epidemic, interest in TP has increased because of its rising incidence in association with HIV infection and of the problems that it poses for differential diagnosis. Occurrence of TP is a criterion for classification of HIV infected patients in WHO disease stage III. The purpose of this report is to describe two HIV-infected patients who presented TP simulating septic arthritis of the hip and knee respectively. Medical imaging was particularly useful in establishing accurate topographic diagnosis and needle drainage in decreasing the duration of hospitalization and avoiding the need for surgical debridement. Needle puncture must be guided by ultrasound or scan imaging.

  9. Bayesian statistic methods and theri application in probabilistic simulation models

    Directory of Open Access Journals (Sweden)

    Sergio Iannazzo

    2007-03-01

    Full Text Available Bayesian statistic methods are facing a rapidly growing level of interest and acceptance in the field of health economics. The reasons of this success are probably to be found on the theoretical fundaments of the discipline that make these techniques more appealing to decision analysis. To this point should be added the modern IT progress that has developed different flexible and powerful statistical software framework. Among them probably one of the most noticeably is the BUGS language project and its standalone application for MS Windows WinBUGS. Scope of this paper is to introduce the subject and to show some interesting applications of WinBUGS in developing complex economical models based on Markov chains. The advantages of this approach reside on the elegance of the code produced and in its capability to easily develop probabilistic simulations. Moreover an example of the integration of bayesian inference models in a Markov model is shown. This last feature let the analyst conduce statistical analyses on the available sources of evidence and exploit them directly as inputs in the economic model.

  10. Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

    Science.gov (United States)

    Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

    2010-06-01

    Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

  11. A study on the usefulness of high fidelity patient simulation in undergraduate medical education

    Directory of Open Access Journals (Sweden)

    Bikramjit Pal

    2018-01-01

    Full Text Available Introduction: Simulation is the imitation of the operation of a real-world process or system over time. Innovative simulation training solutions are now being used to train medical professionals in an attempt to reduce the number of safety concerns that have adverse effects on the patients. Objectives: (a To determine its usefulness as a teaching or learning tool for management of surgical emergencies, both in the short term and medium term by students’ perception. (b To plan future teaching methodology regarding hi-fidelity simulation based on the study outcomes and re-assessment of the current training modules. Methods: Quasi-experimental time series design with pretest-posttest interventional study. Quantitative data was analysed in terms of Mean, Standard Deviation and standard error of Mean. Statistical tests of significance like Repeated Measure of Analysis of Variance (ANOVA were used for comparisons. P value < 0.001 was considered to be statistically significant. Results: The students opined that the simulated sessions on high fidelity simulators had encouraged their active participation which was appropriate to their current level of learning. It helped them to think fast and the training sessions resembled a real life situation. The study showed that learning had progressively improved with each session of simulation with corresponding decrease in stress. Conclusion: Implementation of high fidelity simulation based learning in our Institute had been perceived favourably by a large number of students in enhancing their knowledge over time in management of trauma and surgical emergencies.

  12. Purpose compliant visual simulation: towards effective and selective methods and techniques of visualisation and simulation

    NARCIS (Netherlands)

    Daru, R.; Venemans, P.

    1998-01-01

    Visualisation, simulation and communication were always intimately interconnected. Visualisations and simulations impersonate existing or virtual realities. Without those tools it is arduous to communicate mental depictions about virtual objects and events. A communication model is presented to

  13. Overview of Computer Simulation Modeling Approaches and Methods

    Science.gov (United States)

    Robert E. Manning; Robert M. Itami; David N. Cole; Randy Gimblett

    2005-01-01

    The field of simulation modeling has grown greatly with recent advances in computer hardware and software. Much of this work has involved large scientific and industrial applications for which substantial financial resources are available. However, advances in object-oriented programming and simulation methodology, concurrent with dramatic increases in computer...

  14. Simulation as a Method of Teaching Communication for Multinational Corporations.

    Science.gov (United States)

    Stull, James B.; Baird, John W.

    Interpersonal simulations may be used as a module in cultural awareness programs to provide realistic environments in which students, supervisors, and managers may practice communication skills that are effective in multicultural environments. To conduct and implement a cross-cultural simulation, facilitators should proceed through four stages:…

  15. LBM-EP: Lattice-Boltzmann method for fast cardiac electrophysiology simulation from 3D images.

    Science.gov (United States)

    Rapaka, S; Mansi, T; Georgescu, B; Pop, M; Wright, G A; Kamen, A; Comaniciu, Dorin

    2012-01-01

    Current treatments of heart rhythm troubles require careful planning and guidance for optimal outcomes. Computational models of cardiac electrophysiology are being proposed for therapy planning but current approaches are either too simplified or too computationally intensive for patient-specific simulations in clinical practice. This paper presents a novel approach, LBM-EP, to solve any type of mono-domain cardiac electrophysiology models at near real-time that is especially tailored for patient-specific simulations. The domain is discretized on a Cartesian grid with a level-set representation of patient's heart geometry, previously estimated from images automatically. The cell model is calculated node-wise, while the transmembrane potential is diffused using Lattice-Boltzmann method within the domain defined by the level-set. Experiments on synthetic cases, on a data set from CESC'10 and on one patient with myocardium scar showed that LBM-EP provides results comparable to an FEM implementation, while being 10 - 45 times faster. Fast, accurate, scalable and requiring no specific meshing, LBM-EP paves the way to efficient and detailed models of cardiac electrophysiology for therapy planning.

  16. Radiant Ceiling Panels Combined with Localized Methods for Improved Thermal Comfort of Both Patient and Medical Staff in Patient Room

    DEFF Research Database (Denmark)

    Mori, Sakura; Barova, Mariya; Bolashikov, Zhecho Dimitrov

    2012-01-01

    The objectives were to identify whether ceiling installed radiant heating panels can provide thermal comfort to the occupants in a patient room, and to determine a method for optimal thermal environment to both patient and medical staff simultaneously. The experiments were performed in a climate...... mattress were used to provide local heating for the patient. The effects of the methods were identified by comparing the manikin based equivalent temperatures. The optimal thermal comfort level for both patient and medical staff would obtained when two conventional cotton blankets were used with extra...... chamber resembling a single-bed patient room under convective air conditioning alone or combined with the ceiling installed radiant heating panels. Two thermal manikins simulated a patient lying in the bed and a doctor standing next to the patient. Conventional cotton blanket, electric blanket, electric...

  17. Conceptualising patient empowerment: a mixed methods study

    NARCIS (Netherlands)

    Bravo, P.; Edwards, A.; Barr, P.J.; Scholl, I.; Elwyn, G.; Mcallister, M.

    2015-01-01

    BACKGROUND: In recent years, interventions and health policy programmes have been established to promote patient empowerment, with a particular focus on patients affected by long-term conditions. However, a clear definition of patient empowerment is lacking, making it difficult to assess

  18. Evaluation of a novel basic life support method in simulated microgravity.

    Science.gov (United States)

    Rehnberg, Lucas; Russomano, Thaws; Falcão, Felipe; Campos, Fabio; Everts, Simon N

    2011-02-01

    If a cardiac arrest occurs in microgravity, current emergency protocols aim to treat patients via a medical restraint system within 2-4 min. It is vital that crewmembers have the ability to perform single-person cardiopulmonary resuscitation (CPR) during this period, allowing time for advanced life support to be deployed. The efficacy of the Evetts-Russomano (ER) method has been tested in 22 s of microgravity in a parabolic flight and has shown that external chest compressions (ECC) and mouth-to-mouth ventilation are possible. There were 21 male subjects who performed both the ER method in simulated microgravity via full body suspension and at +1 Gz. The CPR mannequin was modified to provide accurate readings for ECC depth and a metronome to set the rate at 100 bpm. Heart rate, rate of perceived exertion, and angle of arm flexion were measured with an ECG, elbow electrogoniometers, and Borg scale, respectively. The mean (+/- SD) depth of ECC in simulated microgravity was lower in each of the 3 min compared to +1 G2. The ECC depth (45.7 +/- 2.7 mm, 42.3 +/- 5.5 mm, and 41.4 +/- 5.9 mm) and rate (104.5 +/- 5.2, 105.2 +/- 4.5, and 102.4 +/- 6.6 compressions/min), however, remained within CPR guidelines during simulated microgravity over the 3-min period. Heart rate, perceived exertion, and elbow flexion of both arms increased using the ER method. The ER method can provide adequate depth and rate of ECC in simulated microgravity for 3 min to allow time to deploy a medical restraint system. There is, however, a physiological cost associated with it and a need to use the flexion of the arms to compensate for the lack of weight.

  19. Simulation

    DEFF Research Database (Denmark)

    Gould, Derek A; Chalmers, Nicholas; Johnson, Sheena J

    2012-01-01

    Recognition of the many limitations of traditional apprenticeship training is driving new approaches to learning medical procedural skills. Among simulation technologies and methods available today, computer-based systems are topical and bring the benefits of automated, repeatable, and reliable p...... performance assessments. Human factors research is central to simulator model development that is relevant to real-world imaging-guided interventional tasks and to the credentialing programs in which it would be used....

  20. Theoretical simulation of the dual-heat-flux method in deep body temperature measurements.

    Science.gov (United States)

    Huang, Ming; Chen, Wenxi

    2010-01-01

    Deep body temperature reveals individual physiological states, and is important in patient monitoring and chronobiological studies. An innovative dual-heat-flux method has been shown experimentally to be competitive with the conventional zero-heat-flow method in its performance, in terms of measurement accuracy and step response to changes in the deep temperature. We have utilized a finite element method to model and simulate the dynamic process of a dual-heat-flux probe in deep body temperature measurements to validate the fundamental principles of the dual-heat-flux method theoretically, and to acquire a detailed quantitative description of the thermal profile of the dual-heat-flux probe. The simulation results show that the estimated deep body temperature is influenced by the ambient temperature (linearly, at a maximum rate of 0.03 °C/°C) and the blood perfusion rate. The corresponding depth of the estimated temperature in the skin and subcutaneous tissue layer is consistent when using the dual-heat-flux probe. Insights in improving the performance of the dual-heat-flux method were discussed for further studies of dual-heat-flux probes, taking into account structural and geometric considerations.

  1. Capturing readiness to learn and collaboration as explored with an interprofessional simulation scenario: A mixed-methods research study.

    Science.gov (United States)

    Rossler, Kelly L; Kimble, Laura P

    2016-01-01

    Didactic lecture does not lend itself to teaching interprofessional collaboration. High-fidelity human patient simulation with a focus on clinical situations/scenarios is highly conducive to interprofessional education. Consequently, a need for research supporting the incorporation of interprofessional education with high-fidelity patient simulation based technology exists. The purpose of this study was to explore readiness for interprofessional learning and collaboration among pre-licensure health professions students participating in an interprofessional education human patient simulation experience. Using a mixed methods convergent parallel design, a sample of 53 pre-licensure health professions students enrolled in nursing, respiratory therapy, health administration, and physical therapy programs within a college of health professions participated in high-fidelity human patient simulation experiences. Perceptions of interprofessional learning and collaboration were measured with the revised Readiness for Interprofessional Learning Scale (RIPLS) and the Health Professional Collaboration Scale (HPCS). Focus groups were conducted during the simulation post-briefing to obtain qualitative data. Statistical analysis included non-parametric, inferential statistics. Qualitative data were analyzed using a phenomenological approach. Pre- and post-RIPLS demonstrated pre-licensure health professions students reported significantly more positive attitudes about readiness for interprofessional learning post-simulation in the areas of team work and collaboration, negative professional identity, and positive professional identity. Post-simulation HPCS revealed pre-licensure nursing and health administration groups reported greater health collaboration during simulation than physical therapy students. Qualitative analysis yielded three themes: "exposure to experiential learning," "acquisition of interactional relationships," and "presence of chronology in role preparation

  2. Nuclear power plant training simulator system and method

    International Nuclear Information System (INIS)

    Ferguson, R.W.; Converse, R.E. Jr.

    1975-01-01

    A system is described for simulating the real-time dynamic operation of a full scope nuclear powered electrical generating plant for operator training utilizing apparatus that includes a control console with plant component control devices and indicating devices for monitoring plant operation. A general purpose digital computer calculates the dynamic simulation data for operating the indicating devices in accordance with the operation of the control devices. The functions for synchronization and calculation are arranged in a priority structure so as to insure an execution order that provides a maximum overlap of data exchange and simulation calculations. (Official Gazette)

  3. Discrete simulation system based on artificial intelligence methods

    Energy Technology Data Exchange (ETDEWEB)

    Futo, I; Szeredi, J

    1982-01-01

    A discrete event simulation system based on the AI language Prolog is presented. The system called t-Prolog extends the traditional possibilities of simulation languages toward automatic problem solving by using backtrack in time and automatic model modification depending on logical deductions. As t-Prolog is an interactive tool, the user has the possibility to interrupt the simulation run to modify the model or to force it to return to a previous state for trying possible alternatives. It admits the construction of goal-oriented or goal-seeking models with variable structure. Models are defined in a restricted version of the first order predicate calculus using Horn clauses. 21 references.

  4. Multiscale optical simulation settings: challenging applications handled with an iterative ray-tracing FDTD interface method.

    Science.gov (United States)

    Leiner, Claude; Nemitz, Wolfgang; Schweitzer, Susanne; Kuna, Ladislav; Wenzl, Franz P; Hartmann, Paul; Satzinger, Valentin; Sommer, Christian

    2016-03-20

    We show that with an appropriate combination of two optical simulation techniques-classical ray-tracing and the finite difference time domain method-an optical device containing multiple diffractive and refractive optical elements can be accurately simulated in an iterative simulation approach. We compare the simulation results with experimental measurements of the device to discuss the applicability and accuracy of our iterative simulation procedure.

  5. Patient safety and quality of care: how may clinical simulation contribute?

    DEFF Research Database (Denmark)

    Jensen, Sanne

    2015-01-01

    The usability of health information technology (IT) is increasingly recognized as critically important to the development of systems that ensure patient safety and quality of care. The substantial complexity of organizations, work practice and physical environments within the healthcare sector...... influences the development and application of health IT. When health IT is introduced in local clinical work practices, potential patient safety hazards and insufficient support of work practices need to be examined. Qualitative methods, such as clinical simulation, may be used to evaluate new technology...

  6. Modified enthalpy method for the simulation of melting and ...

    Indian Academy of Sciences (India)

    These include the implicit time stepping method of Voller & Cross. (1981), explicit enthalpy method of Tacke (1985), centroidal temperature correction method ... In variable viscosity method, viscosity is written as a function of liquid fraction.

  7. Review of Vortex Methods for Simulation of Vortex Breakdown

    National Research Council Canada - National Science Library

    Levinski, Oleg

    2001-01-01

    The aim of this work is to identify current developments in the field of vortex breakdown modelling in order to initiate the development of a numerical model for the simulation of F/A-18 empennage buffet...

  8. High accuracy mantle convection simulation through modern numerical methods

    KAUST Repository

    Kronbichler, Martin; Heister, Timo; Bangerth, Wolfgang

    2012-01-01

    Numerical simulation of the processes in the Earth's mantle is a key piece in understanding its dynamics, composition, history and interaction with the lithosphere and the Earth's core. However, doing so presents many practical difficulties related

  9. New methods for simulation of fractional Brownian motion

    International Nuclear Information System (INIS)

    Yin, Z.M.

    1996-01-01

    We present new algorithms for simulation of fractional Brownian motion (fBm) which comprises a set of important random functions widely used in geophysical and physical modeling, fractal image (landscape) simulating, and signal processing. The new algorithms, which are both accurate and efficient, allow us to generate not only a one-dimensional fBm process, but also two- and three-dimensional fBm fields. 23 refs., 3 figs

  10. NUMERICAL METHODS FOR THE SIMULATION OF HIGH INTENSITY HADRON SYNCHROTRONS.

    Energy Technology Data Exchange (ETDEWEB)

    LUCCIO, A.; D' IMPERIO, N.; MALITSKY, N.

    2005-09-12

    Numerical algorithms for PIC simulation of beam dynamics in a high intensity synchrotron on a parallel computer are presented. We introduce numerical solvers of the Laplace-Poisson equation in the presence of walls, and algorithms to compute tunes and twiss functions in the presence of space charge forces. The working code for the simulation here presented is SIMBAD, that can be run as stand alone or as part of the UAL (Unified Accelerator Libraries) package.

  11. On Partitioned Simulation of Electrical Circuits using Dynamic Iteration Methods

    OpenAIRE

    Ebert, Falk

    2008-01-01

    Im Rahmen dieser Arbeit wird die partitionierte Simulation elektrischer Schaltkreise untersucht. Hierbei handelt es sich um eine Technik, verschiedene Teile eines Schaltkreises auf unterschiedliche Weise numerisch zu behandeln um eine Simulation für den Gesamtkreis zu erhalten. Dabei wird besonderes Augenmerk auf zwei Dinge gelegt. Zum einen sollen sämtliche analytischen Resultate eine graphentheoretische Interpretation zulassen. Diese Bedingung resultiert daraus, dass Schaltkreisgleichungen ...

  12. Computational simulation in architectural and environmental acoustics methods and applications of wave-based computation

    CERN Document Server

    Sakamoto, Shinichi; Otsuru, Toru

    2014-01-01

    This book reviews a variety of methods for wave-based acoustic simulation and recent applications to architectural and environmental acoustic problems. Following an introduction providing an overview of computational simulation of sound environment, the book is in two parts: four chapters on methods and four chapters on applications. The first part explains the fundamentals and advanced techniques for three popular methods, namely, the finite-difference time-domain method, the finite element method, and the boundary element method, as well as alternative time-domain methods. The second part demonstrates various applications to room acoustics simulation, noise propagation simulation, acoustic property simulation for building components, and auralization. This book is a valuable reference that covers the state of the art in computational simulation for architectural and environmental acoustics.  

  13. Enhancing Care Transitions for Older People through Interprofessional Simulation: A Mixed Method Evaluation

    Directory of Open Access Journals (Sweden)

    Susie Sykes

    2017-11-01

    Full Text Available Introduction: The educational needs of the health and social care workforce for delivering effective integrated care are important. This paper reports on the development, pilot and evaluation of an interprofessional simulation course, which aimed to support integrated care models for care transitions for older people from hospital to home. Theory and methods: The course development was informed by a literature review and a scoping exercise with the health and social care workforce. The course ran six times and was attended by health and social care professionals from hospital and community (n = 49. The evaluation aimed to elicit staff perceptions of their learning about care transfers of older people and to explore application of learning into practice and perceived outcomes. The study used a sequential mixed method design with questionnaires completed pre (n = 44 and post (n = 47 course and interviews (n = 9 2–5 months later. Results: Participants evaluated interprofessional simulation as a successful strategy. Post-course, participants identified learning points and at the interviews, similar themes with examples of application in practice were: Understanding individual needs and empathy; Communicating with patients and families; Interprofessional working; Working across settings to achieve effective care transitions. Conclusions and discussion: An interprofessional simulation course successfully brought together health and social care professionals across settings to develop integrated care skills and improve care transitions for older people with complex needs from hospital to home.

  14. A simulation framework for mapping risks in clinical processes: the case of in-patient transfers

    Science.gov (United States)

    Ong, Mei-Sing; Westbrook, Johanna I; Magrabi, Farah; Coiera, Enrico; Wobcke, Wayne

    2011-01-01

    Objective To model how individual violations in routine clinical processes cumulatively contribute to the risk of adverse events in hospital using an agent-based simulation framework. Design An agent-based simulation was designed to model the cascade of common violations that contribute to the risk of adverse events in routine clinical processes. Clinicians and the information systems that support them were represented as a group of interacting agents using data from direct observations. The model was calibrated using data from 101 patient transfers observed in a hospital and results were validated for one of two scenarios (a misidentification scenario and an infection control scenario). Repeated simulations using the calibrated model were undertaken to create a distribution of possible process outcomes. The likelihood of end-of-chain risk is the main outcome measure, reported for each of the two scenarios. Results The simulations demonstrate end-of-chain risks of 8% and 24% for the misidentification and infection control scenarios, respectively. Over 95% of the simulations in both scenarios are unique, indicating that the in-patient transfer process diverges from prescribed work practices in a variety of ways. Conclusions The simulation allowed us to model the risk of adverse events in a clinical process, by generating the variety of possible work subject to violations, a novel prospective risk analysis method. The in-patient transfer process has a high proportion of unique trajectories, implying that risk mitigation may benefit from focusing on reducing complexity rather than augmenting the process with further rule-based protocols. PMID:21486883

  15. Strengthening student communication through pediatric simulated patient encounters

    Directory of Open Access Journals (Sweden)

    Ryan Whitt

    2014-08-01

    Full Text Available As medical students enter the role of physician, clinical outcomes not only rely on their mastery of clinical knowledge, but also on the effectiveness in which they can communicate with patients and family members. While students typically have numerous opportunities to practice clinical communication with adult patients, such practice in pediatric settings is limited. This study examines if simulated patient (SP encounters strengthen third-year medical students’ communication skills during the pediatrics clerkship. During 2011-2013, three SP encounters (comprising 3 pediatric scenarios were incorporated into a pediatrics clerkship at one United States medical school to give students a safe venue to practice advanced communication with observation and direct feedback. Third-year medical students engaged in the scenarios and received both written and oral feedback from an evaluator observing the encounter. With IRB approval, students’ self-perceived confidence and abilities at performing the advanced communication skills were measured using an eightitem, Likert scale questionnaire administered pre and post the SP encounter. Pre- and post-questionnaires (n = 215; response rate, 96% analyzed using a Wilcoxon-matched pairs signed-rank test demonstrated statistically significant increases in students’ perception of their confidence and abilities regarding their performance (P < 0.05; Bonferroni correction, P < 0.006. There was an increases in student confidence and self-perceived ability in: first, communicating with children and family members of young patients; second, managing confrontational situations involving parents; third, performing a thorough psychosocial history with an adolescent; and fourth, using Evidence Based Medicine to motivate parents.

  16. Selecting a dynamic simulation modeling method for health care delivery research-part 2: report of the ISPOR Dynamic Simulation Modeling Emerging Good Practices Task Force.

    Science.gov (United States)

    Marshall, Deborah A; Burgos-Liz, Lina; IJzerman, Maarten J; Crown, William; Padula, William V; Wong, Peter K; Pasupathy, Kalyan S; Higashi, Mitchell K; Osgood, Nathaniel D

    2015-03-01

    In a previous report, the ISPOR Task Force on Dynamic Simulation Modeling Applications in Health Care Delivery Research Emerging Good Practices introduced the fundamentals of dynamic simulation modeling and identified the types of health care delivery problems for which dynamic simulation modeling can be used more effectively than other modeling methods. The hierarchical relationship between the health care delivery system, providers, patients, and other stakeholders exhibits a level of complexity that ought to be captured using dynamic simulation modeling methods. As a tool to help researchers decide whether dynamic simulation modeling is an appropriate method for modeling the effects of an intervention on a health care system, we presented the System, Interactions, Multilevel, Understanding, Loops, Agents, Time, Emergence (SIMULATE) checklist consisting of eight elements. This report builds on the previous work, systematically comparing each of the three most commonly used dynamic simulation modeling methods-system dynamics, discrete-event simulation, and agent-based modeling. We review criteria for selecting the most suitable method depending on 1) the purpose-type of problem and research questions being investigated, 2) the object-scope of the model, and 3) the method to model the object to achieve the purpose. Finally, we provide guidance for emerging good practices for dynamic simulation modeling in the health sector, covering all aspects, from the engagement of decision makers in the model design through model maintenance and upkeep. We conclude by providing some recommendations about the application of these methods to add value to informed decision making, with an emphasis on stakeholder engagement, starting with the problem definition. Finally, we identify areas in which further methodological development will likely occur given the growing "volume, velocity and variety" and availability of "big data" to provide empirical evidence and techniques

  17. Degrees of reality: airway anatomy of high-fidelity human patient simulators and airway trainers.

    Science.gov (United States)

    Schebesta, Karl; Hüpfl, Michael; Rössler, Bernhard; Ringl, Helmut; Müller, Michael P; Kimberger, Oliver

    2012-06-01

    Human patient simulators and airway training manikins are widely used to train airway management skills to medical professionals. Furthermore, these patient simulators are employed as standardized "patients" to evaluate airway devices. However, little is known about how realistic these patient simulators and airway-training manikins really are. This trial aimed to evaluate the upper airway anatomy of four high-fidelity patient simulators and two airway trainers in comparison with actual patients by means of radiographic measurements. The volume of the pharyngeal airspace was the primary outcome parameter. Computed tomography scans of 20 adult trauma patients without head or neck injuries were compared with computed tomography scans of four high-fidelity patient simulators and two airway trainers. By using 14 predefined distances, two cross-sectional areas and three volume parameters of the upper airway, the manikins' similarity to a human patient was assessed. The pharyngeal airspace of all manikins differed significantly from the patients' pharyngeal airspace. The HPS Human Patient Simulator (METI®, Sarasota, FL) was the most realistic high-fidelity patient simulator (6/19 [32%] of all parameters were within the 95% CI of human airway measurements). The airway anatomy of four high-fidelity patient simulators and two airway trainers does not reflect the upper airway anatomy of actual patients. This finding may impact airway training and confound comparative airway device studies.

  18. Simulating Social Networks of Online Communities: Simulation as a Method for Sociability Design

    Science.gov (United States)

    Ang, Chee Siang; Zaphiris, Panayiotis

    We propose the use of social simulations to study and support the design of online communities. In this paper, we developed an Agent-Based Model (ABM) to simulate and study the formation of social networks in a Massively Multiplayer Online Role Playing Game (MMORPG) guild community. We first analyzed the activities and the social network (who-interacts-with-whom) of an existing guild community to identify its interaction patterns and characteristics. Then, based on the empirical results, we derived and formalized the interaction rules, which were implemented in our simulation. Using the simulation, we reproduced the observed social network of the guild community as a means of validation. The simulation was then used to examine how various parameters of the community (e.g. the level of activity, the number of neighbors of each agent, etc) could potentially influence the characteristic of the social networks.

  19. The Simulation and Analysis of the Closed Die Hot Forging Process by A Computer Simulation Method

    Directory of Open Access Journals (Sweden)

    Dipakkumar Gohil

    2012-06-01

    Full Text Available The objective of this research work is to study the variation of various parameters such as stress, strain, temperature, force, etc. during the closed die hot forging process. A computer simulation modeling approach has been adopted to transform the theoretical aspects in to a computer algorithm which would be used to simulate and analyze the closed die hot forging process. For the purpose of process study, the entire deformation process has been divided in to finite number of steps appropriately and then the output values have been computed at each deformation step. The results of simulation have been graphically represented and suitable corrective measures are also recommended, if the simulation results do not agree with the theoretical values. This computer simulation approach would significantly improve the productivity and reduce the energy consumption of the overall process for the components which are manufactured by the closed die forging process and contribute towards the efforts in reducing the global warming.

  20. High viscosity fluid simulation using particle-based method

    KAUST Repository

    Chang, Yuanzhang; Bao, Kai; Zhu, Jian; Wu, Enhua

    2011-01-01

    the boundary, ghost particles are employed to enforce the solid boundary condition. Compared with Finite Element Methods with complicated and time-consuming remeshing operations, our method is much more straightforward to implement. Moreover, our method doesn

  1. Method for numerical simulation of two-term exponentially correlated colored noise

    International Nuclear Information System (INIS)

    Yilmaz, B.; Ayik, S.; Abe, Y.; Gokalp, A.; Yilmaz, O.

    2006-01-01

    A method for numerical simulation of two-term exponentially correlated colored noise is proposed. The method is an extension of traditional method for one-term exponentially correlated colored noise. The validity of the algorithm is tested by comparing numerical simulations with analytical results in two physical applications

  2. The null-event method in computer simulation

    International Nuclear Information System (INIS)

    Lin, S.L.

    1978-01-01

    The simulation of collisions of ions moving under the influence of an external field through a neutral gas to non-zero temperatures is discussed as an example of computer models of processes in which a probe particle undergoes a series of interactions with an ensemble of other particles, such that the frequency and outcome of the events depends on internal properties of the second particles. The introduction of null events removes the need for much complicated algebra, leads to a more efficient simulation and reduces the likelihood of logical error. (Auth.)

  3. Addressing Dual Patient and Staff Safety Through A Team-Based Standardized Patient Simulation for Agitation Management in the Emergency Department.

    Science.gov (United States)

    Wong, Ambrose H; Auerbach, Marc A; Ruppel, Halley; Crispino, Lauren J; Rosenberg, Alana; Iennaco, Joanne D; Vaca, Federico E

    2018-06-01

    Emergency departments (EDs) have seen harm rise for both patients and health workers from an increasing rate of agitation events. Team effectiveness during care of this population is particularly challenging because fear of physical harm leads to competing interests. Simulation is frequently employed to improve teamwork in medical resuscitations but has not yet been reported to address team-based behavioral emergency care. As part of a larger investigation of agitated patient care, we designed this secondary study to examine the impact of an interprofessional standardized patient simulation for ED agitation management. We used a mixed-methods approach with emergency medicine resident and attending physicians, Physician Assistants (PAs) and Advanced Practice Registered Nurses (APRNs), ED nurses, technicians, and security officers at two hospital sites. After a simulated agitated patient encounter, we conducted uniprofessional and interprofessional focus groups. We undertook structured thematic analysis using a grounded theory approach. Quantitative data consisted of responses to the KidSIM Questionnaire addressing teamwork and simulation-based learning attitudes before and after each session. We reached data saturation with 57 participants. KidSIM scores revealed significant improvements in attitudes toward relevance of simulation, opportunities for interprofessional education, and situation awareness, as well as four of six questions for roles/responsibilities. Two broad themes emerged from the focus groups: (1) a team-based agitated patient simulation addressed dual safety of staff and patients simultaneously and (2) the experience fostered interprofessional discovery and cooperation in agitation management. A team-based simulated agitated patient encounter highlighted the need to consider the dual safety of staff and patients while facilitating interprofessional dialog and learning. Our findings suggest that simulation may be effective to enhance teamwork in

  4. ''Augmented reality'' in conventional simulation by projection of 3-D structures into 2-D images. A comparison with virtual methods

    International Nuclear Information System (INIS)

    Deutschmann, H.; Nairz, O.; Zehentmayr, F.; Fastner, G.; Sedlmayer, F.; Steininger, P.; Kopp, P.; Merz, F.; Wurstbauer, K.; Kranzinger, M.; Kametriser, G.; Kopp, M.

    2008-01-01

    Background and purpose: in this study, a new method is introduced, which allows the overlay of three-dimensional structures, that have been delineated on transverse slices, onto the fluoroscopy from conventional simulators in real time. Patients and methods: setup deviations between volumetric imaging and simulation were visualized, measured and corrected for 701 patient isocenters. Results: comparing the accuracy to mere virtual simulation lacking additional X-ray imaging, a clear benefit of the new method could be shown. On average, virtual prostate simulations had to be corrected by 0.48 cm (standard deviation [SD] 0.38), and those of the breast by 0.67 cm (SD 0.66). Conclusion: the presented method provides an easy way to determine entity-specific safety margins related to patient setup errors upon registration of bony anatomy (prostate 0.9 cm for 90% of cases, breast 1.3 cm). The important role of planar X-ray imaging was clearly demonstrated. The innovation can also be applied to adaptive image-guided radiotherapy (IGRT) protocols. (orig.)

  5. Adaptive Multiscale Finite Element Method for Subsurface Flow Simulation

    NARCIS (Netherlands)

    Van Esch, J.M.

    2010-01-01

    Natural geological formations generally show multiscale structural and functional heterogeneity evolving over many orders of magnitude in space and time. In subsurface hydrological simulations the geological model focuses on the structural hierarchy of physical sub units and the flow model addresses

  6. Crop canopy BRDF simulation and analysis using Monte Carlo method

    NARCIS (Netherlands)

    Huang, J.; Wu, B.; Tian, Y.; Zeng, Y.

    2006-01-01

    This author designs the random process between photons and crop canopy. A Monte Carlo model has been developed to simulate the Bi-directional Reflectance Distribution Function (BRDF) of crop canopy. Comparing Monte Carlo model to MCRM model, this paper analyzes the variations of different LAD and

  7. Impaired driving simulation in patients with Periodic Limb Movement Disorder and patients with Obstructive Sleep Apnea Syndrome

    NARCIS (Netherlands)

    Gieteling, Esther W.; Bakker, Marije S.; Hoekema, Aarnoud; Maurits, Natasha M.; Brouwer, Wiebo H.; van der Hoeven, Johannes H.

    Background: Excessive daytime sleepiness (EDS) is considered to be responsible for increased collision rate and impaired driving simulator performance in Obstructive Sleep Apnea Syndrome (OSAS) patients. Periodic Limb Movement Disorder (PLMD) patients also frequently report EDS and may also have

  8. Error identification and recovery by student nurses using human patient simulation: opportunity to improve patient safety.

    Science.gov (United States)

    Henneman, Elizabeth A; Roche, Joan P; Fisher, Donald L; Cunningham, Helene; Reilly, Cheryl A; Nathanson, Brian H; Henneman, Philip L

    2010-02-01

    This study examined types of errors that occurred or were recovered in a simulated environment by student nurses. Errors occurred in all four rule-based error categories, and all students committed at least one error. The most frequent errors occurred in the verification category. Another common error was related to physician interactions. The least common errors were related to coordinating information with the patient and family. Our finding that 100% of student subjects committed rule-based errors is cause for concern. To decrease errors and improve safe clinical practice, nurse educators must identify effective strategies that students can use to improve patient surveillance. Copyright 2010 Elsevier Inc. All rights reserved.

  9. A Ten-Step Design Method for Simulation Games in Logistics Management

    NARCIS (Netherlands)

    Fumarola, M.; Van Staalduinen, J.P.; Verbraeck, A.

    2011-01-01

    Simulation games have often been found useful as a method of inquiry to gain insight in complex system behavior and as aids for design, engineering simulation and visualization, and education. Designing simulation games are the result of creative thinking and planning, but often not the result of a

  10. The Simulation of the Recharging Method Based on Solar Radiation for an Implantable Biosensor.

    Science.gov (United States)

    Li, Yun; Song, Yong; Kong, Xianyue; Li, Maoyuan; Zhao, Yufei; Hao, Qun; Gao, Tianxin

    2016-09-10

    A method of recharging implantable biosensors based on solar radiation is proposed. Firstly, the models of the proposed method are developed. Secondly, the recharging processes based on solar radiation are simulated using Monte Carlo (MC) method and the energy distributions of sunlight within the different layers of human skin have been achieved and discussed. Finally, the simulation results are verified experimentally, which indicates that the proposed method will contribute to achieve a low-cost, convenient and safe method for recharging implantable biosensors.

  11. ADAM, a hands-on patient simulator for teaching principles of drug disposition and compartmental pharmacokinetics.

    Science.gov (United States)

    Zuna, Ines; Holt, Andrew

    2017-11-01

    To design, construct and validate a pharmacokinetics simulator that offers students hands-on opportunities to participate in the design, administration and analysis of oral and intravenous dosing regimens. The Alberta Drug Administration Modeller (ADAM) is a mechanical patient in which peristaltic circulation of water through a network of silicone tubing and glass bottles creates a representation of the outcomes of drug absorption, distribution, metabolism and elimination. Changing peristaltic pump rates and volumes in bottles allows values for pharmacokinetic constants to be varied, thereby simulating differences in drug properties and in patient physiologies and pathologies. Following administration of methylene blue dye by oral or intravenous routes, plasma and/or urine samples are collected and drug concentrations are determined spectrophotometrically. The effectiveness of the simulator in enhancing student competence and confidence was assessed in two undergraduate laboratory classes. The simulator effectively models one- and two-compartment drug behaviour in a mathematically-robust and realistic manner. Data allow calculation of numerous pharmacokinetic constants, by traditional graphing methods or with curve-fitting software. Students' competence in solving pharmacokinetic problems involving calculations and graphing improved significantly, while an increase in confidence and understanding was reported. The ADAM is relatively inexpensive and straightforward to construct, and offers a realistic, hands-on pharmacokinetics learning opportunity for students that effectively complements didactic lectures. © 2017 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

  12. Patient Satisfaction With Postpartum Teaching Methods.

    Science.gov (United States)

    Wagner, Debra L; Washington, Cynthia

    2016-01-01

    Postpartum discharge instructions are a crucial part of a mother's birth experience. Finding the method to provide those discharge instructions in a manner that increases the mother's satisfaction with her hospital experience is important. This quasi-experimental study examined the relationship between new mothers' interaction with nurses providing postpartum instructions by the traditional and class methods and their satisfaction with discharge teaching. The results indicated new mothers were satisfied with both methods of discharge teaching; however, they were more likely to report stronger agreement with overall satisfaction with the traditional method of discharge teaching than with attending the discharge class.

  13. Truncated Newton-Raphson Methods for Quasicontinuum Simulations

    National Research Council Canada - National Science Library

    Liang, Yu; Kanapady, Ramdev; Chung, Peter W

    2006-01-01

    .... In this research, we report the effectiveness of the truncated Newton-Raphson method and quasi-Newton method with low-rank Hessian update strategy that are evaluated against the full Newton-Raphson...

  14. Numerical simulation of GEW equation using RBF collocation method

    Directory of Open Access Journals (Sweden)

    Hamid Panahipour

    2012-08-01

    Full Text Available The generalized equal width (GEW equation is solved numerically by a meshless method based on a global collocation with standard types of radial basis functions (RBFs. Test problems including propagation of single solitons, interaction of two and three solitons, development of the Maxwellian initial condition pulses, wave undulation and wave generation are used to indicate the efficiency and accuracy of the method. Comparisons are made between the results of the proposed method and some other published numerical methods.

  15. External individual monitoring: experiments and simulations using Monte Carlo Method

    International Nuclear Information System (INIS)

    Guimaraes, Carla da Costa

    2005-01-01

    In this work, we have evaluated the possibility of applying the Monte Carlo simulation technique in photon dosimetry of external individual monitoring. The GEANT4 toolkit was employed to simulate experiments with radiation monitors containing TLD-100 and CaF 2 :NaCl thermoluminescent detectors. As a first step, X ray spectra were generated impinging electrons on a tungsten target. Then, the produced photon beam was filtered in a beryllium window and additional filters to obtain the radiation with desired qualities. This procedure, used to simulate radiation fields produced by a X ray tube, was validated by comparing characteristics such as half value layer, which was also experimentally measured, mean photon energy and the spectral resolution of simulated spectra with that of reference spectra established by international standards. In the construction of thermoluminescent dosimeter, two approaches for improvements have. been introduced. The first one was the inclusion of 6% of air in the composition of the CaF 2 :NaCl detector due to the difference between measured and calculated values of its density. Also, comparison between simulated and experimental results showed that the self-attenuation of emitted light in the readout process of the fluorite dosimeter must be taken into account. Then, in the second approach, the light attenuation coefficient of CaF 2 :NaCl compound estimated by simulation to be 2,20(25) mm -1 was introduced. Conversion coefficients C p from air kerma to personal dose equivalent were calculated using a slab water phantom with polymethyl-metacrilate (PMMA) walls, for reference narrow and wide X ray spectrum series [ISO 4037-1], and also for the wide spectra implanted and used in routine at Laboratorio de Dosimetria. Simulations of backscattered radiations by PMMA slab water phantom and slab phantom of ICRU tissue-equivalent material produced very similar results. Therefore, the PMMA slab water phantom that can be easily constructed with low

  16. A Novel Cast Removal Training Simulation to Improve Patient Safety.

    Science.gov (United States)

    Brubacher, Jacob W; Karg, Jeffrey; Weinstock, Peter; Bae, Donald S

    2016-01-01

    Cast application and removal are essential to orthopedics and performed by providers of variable training. Simulation training and practice of proper cast application and removal may reduce injury, optimize outcomes, and reduce health care costs. The purpose of this educational initiative was to develop, validate, and implement a novel simulation trainer and curriculum to improve safety during cast removal. In all, 30 thermocouples (Omega, Stamford, CT) were applied to a radius fracture model (Sawbones, Vashon, WA). After reduction and cast application, a saw (Stryker, Kalamazoo, MI) was used to cut the cast with temperature recording. Both "good" and "poor" techniques-as established by consensus best practices-were used. Maximal temperatures were compared to known thresholds for thermal injury; humans experience pain at temperatures exceeding 47°C and contact temperatures exceeding 60°C may lead to epidermal necrosis. Construct validity was evaluated by assessing novice (postgraduate year 1), intermediate (postgraduate year 3), and expert (pediatric orthopedic attending) performance. With the "good" technique, mean peak temperatures were 43°C + 4.3°C. The highest recorded was 51.9°C. With the "poor" technique, mean peak temperature was 75.2°C + 17.3°C. The maximum temperature recorded with the "poor" technique was 112.4°C. Construct validity testing showed that novices had the highest increases in temperatures (12.9°C). There was a decline in heat generation as experience increased with the intermediate group (9.7°C), and the lowest heat generation was seen in the expert group (5.0°C). A novel task simulator and curriculum have been developed to assess competency and enhance performance in the application and removal of casts. There was a 32.2°C temperature decrease when the proper cast saw technique was used. Furthermore, the "poor" technique consistently achieved temperatures that would cause epidermal necrosis in patients. Clinical experience was a

  17. Fast Multilevel Panel Method for Wind Turbine Rotor Flow Simulations

    NARCIS (Netherlands)

    van Garrel, Arne; Venner, Cornelis H.; Hoeijmakers, Hendrik Willem Marie

    2017-01-01

    A fast multilevel integral transform method has been developed that enables the rapid analysis of unsteady inviscid flows around wind turbines rotors. A low order panel method is used and the new multi-level multi-integration cluster (MLMIC) method reduces the computational complexity for

  18. Simulation methods for multiperiodic and aperiodic nanostructured dielectric waveguides

    DEFF Research Database (Denmark)

    Paulsen, Moritz; Neustock, Lars Thorben; Jahns, Sabrina

    2017-01-01

    on Rudin–Shapiro, Fibonacci, and Thue–Morse binary sequences. The near-field and far-field properties are computed employing the finite-element method (FEM), the finite-difference time-domain (FDTD) method as well as a rigorous coupled wave algorithm (RCWA). The results show that all three methods...

  19. Simulating elastic light scattering using high performance computing methods

    NARCIS (Netherlands)

    Hoekstra, A.G.; Sloot, P.M.A.; Verbraeck, A.; Kerckhoffs, E.J.H.

    1993-01-01

    The Coupled Dipole method, as originally formulated byPurcell and Pennypacker, is a very powerful method tosimulate the Elastic Light Scattering from arbitraryparticles. This method, which is a particle simulationmodel for Computational Electromagnetics, has one majordrawback: if the size of the

  20. Geometry optimization of zirconium sulfophenylphosphonate layers by molecular simulation methods

    Czech Academy of Sciences Publication Activity Database

    Škoda, J.; Pospíšil, M.; Kovář, P.; Melánová, Klára; Svoboda, J.; Beneš, L.; Zima, Vítězslav

    2018-01-01

    Roč. 24, č. 1 (2018), s. 1-12, č. článku 10. ISSN 1610-2940 R&D Projects: GA ČR(CZ) GA14-13368S; GA ČR(CZ) GA17-10639S Institutional support: RVO:61389013 Keywords : zirconium sulfophenylphosphonate * intercalation * molecular simulation Subject RIV: CA - Inorganic Chemistry OBOR OECD: Inorganic and nuclear chemistry Impact factor: 1.425, year: 2016

  1. Absolute efficiency calibration of HPGe detector by simulation method

    International Nuclear Information System (INIS)

    Narayani, K.; Pant, Amar D.; Verma, Amit K.; Bhosale, N.A.; Anilkumar, S.

    2018-01-01

    High resolution gamma ray spectrometry by HPGe detectors is a powerful radio analytical technique for estimation of activity of various radionuclides. In the present work absolute efficiency calibration of the HPGe detector was carried out using Monte Carlo simulation technique and results are compared with those obtained by experiment using standard radionuclides of 152 Eu and 133 Ba. The coincidence summing correction factors for the measurement of these nuclides were also calculated

  2. Quantum mechanical simulation methods for studying biological systems

    International Nuclear Information System (INIS)

    Bicout, D.; Field, M.

    1996-01-01

    Most known biological mechanisms can be explained using fundamental laws of physics and chemistry and a full understanding of biological processes requires a multidisciplinary approach in which all the tools of biology, chemistry and physics are employed. An area of research becoming increasingly important is the theoretical study of biological macromolecules where numerical experimentation plays a double role of establishing a link between theoretical models and predictions and allowing a quantitative comparison between experiments and models. This workshop brought researchers working on different aspects of the development and application of quantum mechanical simulation together, assessed the state-of-the-art in the field and highlighted directions for future research. Fourteen lectures (theoretical courses and specialized seminars) deal with following themes: 1) quantum mechanical calculations of large systems, 2) ab initio molecular dynamics where the calculation of the wavefunction and hence the energy and forces on the atoms for a system at a single nuclear configuration are combined with classical molecular dynamics algorithms in order to perform simulations which use a quantum mechanical potential energy surface, 3) quantum dynamical simulations, electron and proton transfer processes in proteins and in solutions and finally, 4) free seminars that helped to enlarge the scope of the workshop. (N.T.)

  3. Dr. Tulp attends the soft machine: patient simulators, user involvement and intellectual disability.

    Science.gov (United States)

    McClimens, Alex; Lewis, Robin; Brewster, Jacqui

    2012-09-01

    Simulation as a way to teach clinical skills attracts much critical attention. Its benefits, however, might be significantly reduced when the simulation model used relies exclusively on patient simulators. This is particularly true if the intended patient population for students taught is characterized by intellectual disability. Learning to care for people with intellectual disability might be better supplemented when the simulation model used incorporates input from 'real' people. If these people themselves have intellectual disabilities then the verisimilitude of the simulation will be higher and the outcomes for learners and potential patients will also be improved.

  4. Pulse contour analysis of arterial waveform in a high fidelity human patient simulator.

    Science.gov (United States)

    Persona, Paolo; Saraceni, Elisabetta; Facchin, Francesca; Petranzan, Enrico; Parotto, Matteo; Baratto, Fabio; Ori, Carlo; Rossi, Sandra

    2017-10-03

    The measurement of cardiac output (CO) may be useful to improve the assessment of hemodynamics during simulated scenarios. The purpose of this study was to evaluate the feasibility of introducing an uncalibrated pulse contour device (MostCare, Vytech, Vygon, Padova, Italy) into the simulation environment. MostCare device was plugged to a clinical monitor and connected to the METI human patient simulator (HPS) to obtain a continuous arterial waveform analysis and CO calculation. In six different simulated clinical scenarios (baseline, ventricular failure, vasoplegic shock, hypertensive crisis, hypovolemic shock and aortic stenosis), the HPS-CO and the MostCare-CO were simultaneously recorded. The level of concordance between the two methods was assessed by the Bland and Altman analysis. 150-paired CO values were obtained. The HPS-CO values ranged from 2.3 to 6.6 L min -1 and the MostCare-CO values from 2.8 to 6.4 L min -1 . The mean difference between HPS-CO and MostCare-CO was - 0.3 L min -1 and the limits of agreement were - 1.5 and 0.9 L min -1 . The percentage of error was 23%. A good correlation between HPS-CO and MostCare-CO was observed in each scenario of the study (r = 0.88). Although MostCare-CO tended to underestimate the CO over the study period, good agreements were found between the two methods. Therefore, a pulse contour device can be integrated into the simulation environment, offering the opportunity to create new simulated clinical settings.

  5. Explicit Singly Diagonally Implicit Runge-Kutta Methods and Adaptive Stepsize Control for Reservoir Simulation

    DEFF Research Database (Denmark)

    Völcker, Carsten; Jørgensen, John Bagterp; Thomsen, Per Grove

    2010-01-01

    The implicit Euler method, normally refered to as the fully implicit (FIM) method, and the implicit pressure explicit saturation (IMPES) method are the traditional choices for temporal discretization in reservoir simulation. The FIM method offers unconditionally stability in the sense of discrete......-Kutta methods, ESDIRK, Newton-Raphson, convergence control, error control, stepsize selection....

  6. Mock ECHO: A Simulation-Based Medical Education Method.

    Science.gov (United States)

    Fowler, Rebecca C; Katzman, Joanna G; Comerci, George D; Shelley, Brian M; Duhigg, Daniel; Olivas, Cynthia; Arnold, Thomas; Kalishman, Summers; Monnette, Rebecca; Arora, Sanjeev

    2018-04-16

    This study was designed to develop a deeper understanding of the learning and social processes that take place during the simulation-based medical education for practicing providers as part of the Project ECHO® model, known as Mock ECHO training. The ECHO model is utilized to expand access to care of common and complex diseases by supporting the education of primary care providers with an interprofessional team of specialists via videoconferencing networks. Mock ECHO trainings are conducted through a train the trainer model targeted at leaders replicating the ECHO model at their organizations. Trainers conduct simulated teleECHO clinics while participants gain skills to improve communication and self-efficacy. Three focus groups, conducted between May 2015 and January 2016 with a total of 26 participants, were deductively analyzed to identify common themes related to simulation-based medical education and interdisciplinary education. Principal themes generated from the analysis included (a) the role of empathy in community development, (b) the value of training tools as guides for learning, (c) Mock ECHO design components to optimize learning, (d) the role of interdisciplinary education to build community and improve care delivery, (e) improving care integration through collaboration, and (f) development of soft skills to facilitate learning. Mock ECHO trainings offer clinicians the freedom to learn in a noncritical environment while emphasizing real-time multidirectional feedback and encouraging knowledge and skill transfer. The success of the ECHO model depends on training interprofessional healthcare providers in behaviors needed to lead a teleECHO clinic and to collaborate in the educational process. While building a community of practice, Mock ECHO provides a safe opportunity for a diverse group of clinician experts to practice learned skills and receive feedback from coparticipants and facilitators.

  7. Computerized method for X-ray angular distribution simulation in radiological systems

    International Nuclear Information System (INIS)

    Marques, Marcio A.; Oliveira, Henrique J.Q. de; Frere, Annie F.; Schiabel, Homero; Marques, Paulo M.A.

    1996-01-01

    A method to simulate the changes in X-ray angular distribution (the Heel effect) for radiologic imaging systems is presented. This simulation method is described as to predict images for any exposure technique considering that the distribution is the cause of the intensity variation along the radiation field

  8. Contribution of the ultrasonic simulation to the testing methods qualification process

    International Nuclear Information System (INIS)

    Le Ber, L.; Calmon, P.; Abittan, E.

    2001-01-01

    The CEA and EDF have started a study concerning the simulation interest in the qualification of nuclear components control by ultrasonic methods. In this framework, the simulation tools of the CEA, as CIVA, have been tested on real control. The method and the results obtained on some examples are presented. (A.L.B.)

  9. 2D Quantum Simulation of MOSFET Using the Non Equilibrium Green's Function Method

    Science.gov (United States)

    Svizhenko, Alexel; Anantram, M. P.; Govindan, T. R.; Yan, Jerry (Technical Monitor)

    2000-01-01

    The objectives this viewgraph presentation summarizes include: (1) the development of a quantum mechanical simulator for ultra short channel MOSFET simulation, including theory, physical approximations, and computer code; (2) explore physics that is not accessible by semiclassical methods; (3) benchmarking of semiclassical and classical methods; and (4) study other two-dimensional devices and molecular structure, from discretized Hamiltonian to tight-binding Hamiltonian.

  10. Digital system verification a combined formal methods and simulation framework

    CERN Document Server

    Li, Lun

    2010-01-01

    Integrated circuit capacity follows Moore's law, and chips are commonly produced at the time of this writing with over 70 million gates per device. Ensuring correct functional behavior of such large designs before fabrication poses an extremely challenging problem. Formal verification validates the correctness of the implementation of a design with respect to its specification through mathematical proof techniques. Formal techniques have been emerging as commercialized EDA tools in the past decade. Simulation remains a predominantly used tool to validate a design in industry. After more than 5

  11. Achieving better cooling of turbine blades using numerical simulation methods

    Science.gov (United States)

    Inozemtsev, A. A.; Tikhonov, A. S.; Sendyurev, C. I.; Samokhvalov, N. Yu.

    2013-02-01

    A new design of the first-stage nozzle vane for the turbine of a prospective gas-turbine engine is considered. The blade's thermal state is numerically simulated in conjugate statement using the ANSYS CFX 13.0 software package. Critical locations in the blade design are determined from the distribution of heat fluxes, and measures aimed at achieving more efficient cooling are analyzed. Essentially lower (by 50-100°C) maximal temperature of metal has been achieved owing to the results of the performed work.

  12. Simulation Methods in the Contact with Impact of Rigid Bodies

    Directory of Open Access Journals (Sweden)

    Cristina Basarabă-Opritescu

    2007-10-01

    Full Text Available The analysis of impacts of elastic bodies is topical and it has many applications, practical and theoretical, too. The elastic character of collision is put in evidence, especially by the velocities of some parts of a particular body, named “ring”. In the presented paper, the situation of elastic collisions is put in evidence by the simulation with the help of the program ANSYS and it refers to the particular case of the ring, with the mechanical characteristics, given in the paper

  13. Modelling and simulation of diffusive processes methods and applications

    CERN Document Server

    Basu, SK

    2014-01-01

    This book addresses the key issues in the modeling and simulation of diffusive processes from a wide spectrum of different applications across a broad range of disciplines. Features: discusses diffusion and molecular transport in living cells and suspended sediment in open channels; examines the modeling of peristaltic transport of nanofluids, and isotachophoretic separation of ionic samples in microfluidics; reviews thermal characterization of non-homogeneous media and scale-dependent porous dispersion resulting from velocity fluctuations; describes the modeling of nitrogen fate and transport

  14. Sensitivity of Particle Size in Discrete Element Method to Particle Gas Method (DEM_PGM) Coupling in Underbody Blast Simulations

    Science.gov (United States)

    2016-06-12

    Particle Size in Discrete Element Method to Particle Gas Method (DEM_PGM) Coupling in Underbody Blast Simulations Venkatesh Babu, Kumar Kulkarni, Sanjay...buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) and (2) Arbitrary Lagrangian-Eulerian (ALE), are investigated. The...DEM_PGM and identify the limitations/strengths compared to the ALE method. Discrete Element Method (DEM) can model individual particle directly, and

  15. Advanced scientific computational methods and their applications to nuclear technologies. (3) Introduction of continuum simulation methods and their applications (3)

    International Nuclear Information System (INIS)

    Satake, Shin-ichi; Kunugi, Tomoaki

    2006-01-01

    Scientific computational methods have advanced remarkably with the progress of nuclear development. They have played the role of weft connecting each realm of nuclear engineering and then an introductory course of advanced scientific computational methods and their applications to nuclear technologies were prepared in serial form. This is the third issue showing the introduction of continuum simulation methods and their applications. Spectral methods and multi-interface calculation methods in fluid dynamics are reviewed. (T. Tanaka)

  16. Numerical simulation of electromagnetic waves in Schwarzschild space-time by finite difference time domain method and Green function method

    Science.gov (United States)

    Jia, Shouqing; La, Dongsheng; Ma, Xuelian

    2018-04-01

    The finite difference time domain (FDTD) algorithm and Green function algorithm are implemented into the numerical simulation of electromagnetic waves in Schwarzschild space-time. FDTD method in curved space-time is developed by filling the flat space-time with an equivalent medium. Green function in curved space-time is obtained by solving transport equations. Simulation results validate both the FDTD code and Green function code. The methods developed in this paper offer a tool to solve electromagnetic scattering problems.

  17. Simulation Methods for Multiperiodic and Aperiodic Nanostructured Dielectric Waveguides

    DEFF Research Database (Denmark)

    Paulsen, Moritz; Neustock, Lars Thorben; Jahns, Sabrina

    on Rudin-Shapiro, Fibonacci, and Thue-Morse binary sequences. The near-field and far-field properties are calculated employing the finite-element method (FEM), the finite- difference time-domain (FDTD) method as well as a rigorous coupled wave algorithm (RCWA). References [1] S. V. Boriskina, A. Gopinath...

  18. Nonequilibrium relaxation method – An alternative simulation strategy

    Indian Academy of Sciences (India)

    This equilibrium method traces over the standard theory of the thermal ... The purpose of this article is to give a concise review of the idea of the NER method .... using the NER functions from mixed initial configuration, that is, half of the system.

  19. Simulation of crystalline pattern formation by the MPFC method

    Directory of Open Access Journals (Sweden)

    Starodumov Ilya

    2017-01-01

    Full Text Available The Phase Field Crystal model in hyperbolic formulation (modified PFC or MPFC, is investigated as one of the most promising techniques for modeling the formation of crystal patterns. MPFC is a convenient and fundamentally based description linking nano-and meso-scale processes in the evolution of crystal structures. The presented model is a powerful tool for mathematical modeling of the various operations in manufacturing. Among them is the definition of process conditions for the production of metal castings with predetermined properties, the prediction of defects in the crystal structure during casting, the evaluation of quality of special coatings, and others. Our paper presents the structure diagram which was calculated for the one-mode MPFC model and compared to the results of numerical simulation for the fast phase transitions. The diagram is verified by the numerical simulation and also strongly correlates to the previously calculated diagrams. The computations have been performed using software based on the effective parallel computational algorithm.

  20. Numerical simulation methods of fires in nuclear power plants

    International Nuclear Information System (INIS)

    Keski-Rahkonen, O.; Bjoerkman, J.; Heikkilae, L.

    1992-01-01

    Fire is a significant hazard to the safety of nuclear power plants (NPP). Fire may be serious accident as such, but even small fire at a critical point in a NPP may cause an accident much more serious than fire itself. According to risk assessments a fire may be an initial cause or a contributing factor in a large part of reactor accidents. At the Fire Technology and the the Nuclear Engineering Laboratory of the Technical Research Centre of Finland (VTT) fire safety research for NPPs has been carried out in a large extent since 1985. During years 1988-92 a project Advanced Numerical Modelling in Nuclear Power Plants (PALOME) was carried out. In the project the level of numerical modelling for fire research in Finland was improved by acquiring, preparing for use and developing numerical fire simulation programs. Large scale test data of the German experimental program (PHDR Sicherheitsprogramm in Kernforschungscentral Karlsruhe) has been as reference. The large scale tests were simulated by numerical codes and results were compared to calculations carried out by others. Scientific interaction with outstanding foreign laboratories and scientists has been an important part of the project. This report describes the work of PALOME-project carried out at the Fire Technology Laboratory only. A report on the work at the Nuclear Engineering Laboratory will be published separatively. (au)

  1. The PDF method for Lagrangian two-phase flow simulations

    International Nuclear Information System (INIS)

    Minier, J.P.; Pozorski, J.

    1996-04-01

    A recent turbulence model put forward by Pope (1991) in the context of PDF modelling has been used. In this approach, the one-point joint velocity-dissipation pdf equation is solved by simulating the instantaneous behaviour of a large number of Lagrangian fluid particles. Closure of the evolution equations of these Lagrangian particles is based on stochastic models and more specifically on diffusion processes. Such models are of direct use for two-phase flow modelling where the so-called fluid seen by discrete inclusions has to be modelled. Full Lagrangian simulations have been performed for shear-flows. It is emphasized that this approach gives far more information than traditional turbulence closures (such as the K-ε model) and therefore can be very useful for situations involving complex physics. It is also believed that the present model represents the first step towards a complete Lagrangian-Lagrangian model for dispersed two-phase flow problems. (authors). 21 refs., 6 figs

  2. A non-discrete method for computation of residence time in fluid mechanics simulations.

    Science.gov (United States)

    Esmaily-Moghadam, Mahdi; Hsia, Tain-Yen; Marsden, Alison L

    2013-11-01

    Cardiovascular simulations provide a promising means to predict risk of thrombosis in grafts, devices, and surgical anatomies in adult and pediatric patients. Although the pathways for platelet activation and clot formation are not yet fully understood, recent findings suggest that thrombosis risk is increased in regions of flow recirculation and high residence time (RT). Current approaches for calculating RT are typically based on releasing a finite number of Lagrangian particles into the flow field and calculating RT by tracking their positions. However, special care must be taken to achieve temporal and spatial convergence, often requiring repeated simulations. In this work, we introduce a non-discrete method in which RT is calculated in an Eulerian framework using the advection-diffusion equation. We first present the formulation for calculating residence time in a given region of interest using two alternate definitions. The physical significance and sensitivity of the two measures of RT are discussed and their mathematical relation is established. An extension to a point-wise value is also presented. The methods presented here are then applied in a 2D cavity and two representative clinical scenarios, involving shunt placement for single ventricle heart defects and Kawasaki disease. In the second case study, we explored the relationship between RT and wall shear stress, a parameter of particular importance in cardiovascular disease.

  3. Using a computer simulation for teaching communication skills: A blinded multisite mixed methods randomized controlled trial

    Science.gov (United States)

    Kron, Frederick W.; Fetters, Michael D.; Scerbo, Mark W.; White, Casey B.; Lypson, Monica L.; Padilla, Miguel A.; Gliva-McConvey, Gayle A.; Belfore, Lee A.; West, Temple; Wallace, Amelia M.; Guetterman, Timothy C.; Schleicher, Lauren S.; Kennedy, Rebecca A.; Mangrulkar, Rajesh S.; Cleary, James F.; Marsella, Stacy C.; Becker, Daniel M.

    2016-01-01

    Objectives To assess advanced communication skills among second-year medical students exposed either to a computer simulation (MPathic-VR) featuring virtual humans, or to a multimedia computer-based learning module, and to understand each group’s experiences and learning preferences. Methods A single-blinded, mixed methods, randomized, multisite trial compared MPathic-VR (N=210) to computer-based learning (N=211). Primary outcomes: communication scores during repeat interactions with MPathic-VR’s intercultural and interprofessional communication scenarios and scores on a subsequent advanced communication skills objective structured clinical examination (OSCE). Multivariate analysis of variance was used to compare outcomes. Secondary outcomes: student attitude surveys and qualitative assessments of their experiences with MPathic-VR or computer-based learning. Results MPathic-VR-trained students improved their intercultural and interprofessional communication performance between their first and second interactions with each scenario. They also achieved significantly higher composite scores on the OSCE than computer-based learning-trained students. Attitudes and experiences were more positive among students trained with MPathic-VR, who valued its providing immediate feedback, teaching nonverbal communication skills, and preparing them for emotion-charged patient encounters. Conclusions MPathic-VR was effective in training advanced communication skills and in enabling knowledge transfer into a more realistic clinical situation. Practice Implications MPathic-VR’s virtual human simulation offers an effective and engaging means of advanced communication training. PMID:27939846

  4. Reconstruction of X-rays spectra of clinical linear accelerators using the generalized simulated annealing method

    International Nuclear Information System (INIS)

    Manrique, John Peter O.; Costa, Alessandro M.

    2016-01-01

    The spectral distribution of megavoltage X-rays used in radiotherapy departments is a fundamental quantity from which, in principle, all relevant information required for radiotherapy treatments can be determined. To calculate the dose delivered to the patient who make radiation therapy, are used treatment planning systems (TPS), which make use of convolution and superposition algorithms and which requires prior knowledge of the photon fluence spectrum to perform the calculation of three-dimensional doses and thus ensure better accuracy in the tumor control probabilities preserving the normal tissue complication probabilities low. In this work we have obtained the photon fluence spectrum of X-ray of the SIEMENS ONCOR linear accelerator of 6 MV, using an character-inverse method to the reconstruction of the spectra of photons from transmission curves measured for different thicknesses of aluminum; the method used for reconstruction of the spectra is a stochastic technique known as generalized simulated annealing (GSA), based on the work of quasi-equilibrium statistic of Tsallis. For the validation of the reconstructed spectra we calculated the curve of percentage depth dose (PDD) for energy of 6 MV, using Monte Carlo simulation with Penelope code, and from the PDD then calculate the beam quality index TPR_2_0_/_1_0. (author)

  5. Cutting Method of the CAD model of the Nuclear facility for Dismantling Simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ikjune; Choi, ByungSeon; Hyun, Dongjun; Jeong, KwanSeong; Kim, GeunHo; Lee, Jonghwan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2015-05-15

    Current methods for process simulation cannot simulate the cutting operation flexibly. As is, to simulate a cutting operation, user needs to prepare the result models of cutting operation based on pre-define cutting path, depth and thickness with respect to a dismantle scenario in advance. And those preparations should be built again as scenario changes. To be, user can change parameters and scenarios dynamically within a simulation configuration process so that the user saves time and efforts to simulate cutting operations. This study presents the methodology of cutting operation which can be applied to all the procedure in the simulation of dismantling of nuclear facilities. We developed the cutting simulation module for cutting operation in the dismantling of the nuclear facilities based on proposed cutting methodology. We defined the requirement of model cutting methodology based on the requirement of the dismantling of nuclear facilities. And we implemented cutting simulation module based on API of the commercial CAD system.

  6. Comparative Study on Two Melting Simulation Methods: Melting Curve of Gold

    International Nuclear Information System (INIS)

    Liu Zhong-Li; Li Rui; Sun Jun-Sheng; Zhang Xiu-Lu; Cai Ling-Cang

    2016-01-01

    Melting simulation methods are of crucial importance to determining melting temperature of materials efficiently. A high-efficiency melting simulation method saves much simulation time and computational resources. To compare the efficiency of our newly developed shock melting (SM) method with that of the well-established two-phase (TP) method, we calculate the high-pressure melting curve of Au using the two methods based on the optimally selected interatomic potentials. Although we only use 640 atoms to determine the melting temperature of Au in the SM method, the resulting melting curve accords very well with the results from the TP method using much more atoms. Thus, this shows that a much smaller system size in SM method can still achieve a fully converged melting curve compared with the TP method, implying the robustness and efficiency of the SM method. (paper)

  7. Multigrid methods for fully implicit oil reservoir simulation

    Energy Technology Data Exchange (ETDEWEB)

    Molenaar, J.

    1995-12-31

    In this paper, the authors consider the simultaneous flow of oil and water in reservoir rock. This displacement process is modeled by two basic equations the material balance or continuity equations, and the equation of motion (Darcy`s law). For the numerical solution of this system of nonlinear partial differential equations, there are two approaches: the fully implicit or simultaneous solution method, and the sequential solution method. In this paper, the authors consider the possibility of applying multigrid methods for the iterative solution of the systems of nonlinear equations.

  8. Industrial development of a simulation method for ore recovery evaluation

    International Nuclear Information System (INIS)

    Deraisme; De Fouquet; Fraisse

    1983-01-01

    The purpose of downstream geostatistics is to provide to engineers, responsible for mining project studies, with a method for predicting the ore reserve recovery coming from different mining methods and for choosing the best one according to economic criteria. In the case of the BEN LOMOND uranium deposit, the metal recovery at the production stage depends on the geometry of mineralized lenses. For the first step of this study the usual technique for constructing a numerical model of deposit has been used. But this does not reproduce the geological structures very precisely. The recovered reserves have been computed for three more or less selective mining methods. This has been done inputing the outlines of stopes on a digitalizer. In the case of a cut and fill method an automatic algorithm for the optimization under constraints has been developed [fr

  9. Phase portrait methods for verifying fluid dynamic simulations

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, H.B.

    1989-01-01

    As computing resources become more powerful and accessible, engineers more frequently face the difficult and challenging engineering problem of accurately simulating nonlinear dynamic phenomena. Although mathematical models are usually available, in the form of initial value problems for differential equations, the behavior of the solutions of nonlinear models is often poorly understood. A notable example is fluid dynamics: while the Navier-Stokes equations are believed to correctly describe turbulent flow, no exact mathematical solution of these equations in the turbulent regime is known. Differential equations can of course be solved numerically, but how are we to assess numerical solutions of complex phenomena without some understanding of the mathematical problem and its solutions to guide us

  10. Coupling methods for parallel running RELAPSim codes in nuclear power plant simulation

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yankai; Lin, Meng, E-mail: linmeng@sjtu.edu.cn; Yang, Yanhua

    2016-02-15

    When the plant is modeled detailedly for high precision, it is hard to achieve real-time calculation for one single RELAP5 in a large-scale simulation. To improve the speed and ensure the precision of simulation at the same time, coupling methods for parallel running RELAPSim codes were proposed in this study. Explicit coupling method via coupling boundaries was realized based on a data-exchange and procedure-control environment. Compromise of synchronization frequency was well considered to improve the precision of simulation and guarantee the real-time simulation at the same time. The coupling methods were assessed using both single-phase flow models and two-phase flow models and good agreements were obtained between the splitting–coupling models and the integrated model. The mitigation of SGTR was performed as an integral application of the coupling models. A large-scope NPP simulator was developed adopting six splitting–coupling models of RELAPSim and other simulation codes. The coupling models could improve the speed of simulation significantly and make it possible for real-time calculation. In this paper, the coupling of the models in the engineering simulator is taken as an example to expound the coupling methods, i.e., coupling between parallel running RELAPSim codes, and coupling between RELAPSim code and other types of simulation codes. However, the coupling methods are also referable in other simulator, for example, a simulator employing ATHLETE instead of RELAP5, other logic code instead of SIMULINK. It is believed the coupling method is commonly used for NPP simulator regardless of the specific codes chosen in this paper.

  11. Simulated microbe removal around finger rings using different hand sanitation methods.

    Science.gov (United States)

    Alur, Archana A; Rane, Madhavi J; Scheetz, James P; Lorenz, Douglas J; Gettleman, Lawrence

    2009-09-01

    It is our opinion that the CDC and the WHO have underestimated cross-contamination under examination gloves in dental clinics while wearing jewelry, such as finger rings. These agencies only "recommend" removing jewelry, and only washing hands for 15 seconds with soap and warm water before donning gloves. This study examined several washing procedures and finger rings using simulated microbes. A gloved rubber hand manikin was made and fitted with a fresh disposable vinyl glove. Four fingers were fitted with rings or no ring, dusted with simulated microbes, and washed with a scrub brush for 5, 15, and 25 seconds under 20 degrees C and 40 degrees C water alone, or with liquid hand soap. Light levels (in lux) of fluorescent powder before and after washing were measured and delta scores calculated for changes in light levels, equivalent to effectiveness of hand washing procedures. A full-factorial, 3-factor analysis of variance (ANOVA) was used to test for differences among levels of the three study factors-time, temperature, and soap use. Tukey's post hoc honestly significant difference (HSD) test was applied to significant factors to examine pair-wise differences between factor levels. It was found that the longer the hands with rings were washed with a scrub brush under flowing water, the more simulated microbes were removed. By 25 seconds, all methods were essentially the same. Simulated microbes were more difficult to remove from the palm compared to the back of the hand. The liquid hand soap used in this study was more effective with warm water than cold. When given a choice of washing with cold water up to 15 seconds, it would be preferable not to use soap to remove simulated microbes. Qualitatively, the outer surface of finger rings were more effectively cleaned than the crevice below the ring, and the ring with a stone setting appeared to accumulate and retain simulated microbes more than other rings. The most effective treatment was washing with warm water

  12. Simple Method to Estimate Mean Heart Dose From Hodgkin Lymphoma Radiation Therapy According to Simulation X-Rays

    Energy Technology Data Exchange (ETDEWEB)

    Nimwegen, Frederika A. van [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Cutter, David J. [Clinical Trial Service Unit, University of Oxford, Oxford (United Kingdom); Oxford Cancer Centre, Oxford University Hospitals NHS Trust, Oxford (United Kingdom); Schaapveld, Michael [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Rutten, Annemarieke [Department of Radiology, The Netherlands Cancer Institute, Amsterdam (Netherlands); Kooijman, Karen [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Krol, Augustinus D.G. [Department of Radiation Oncology, Leiden University Medical Center, Leiden (Netherlands); Janus, Cécile P.M. [Department of Radiation Oncology, Erasmus MC Cancer Center, Rotterdam (Netherlands); Darby, Sarah C. [Clinical Trial Service Unit, University of Oxford, Oxford (United Kingdom); Leeuwen, Flora E. van [Department of Psychosocial Research, Epidemiology, and Biostatistics, The Netherlands Cancer Institute, Amsterdam (Netherlands); Aleman, Berthe M.P., E-mail: b.aleman@nki.nl [Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam (Netherlands)

    2015-05-01

    Purpose: To describe a new method to estimate the mean heart dose for Hodgkin lymphoma patients treated several decades ago, using delineation of the heart on radiation therapy simulation X-rays. Mean heart dose is an important predictor for late cardiovascular complications after Hodgkin lymphoma (HL) treatment. For patients treated before the era of computed tomography (CT)-based radiotherapy planning, retrospective estimation of radiation dose to the heart can be labor intensive. Methods and Materials: Patients for whom cardiac radiation doses had previously been estimated by reconstruction of individual treatments on representative CT data sets were selected at random from a case–control study of 5-year Hodgkin lymphoma survivors (n=289). For 42 patients, cardiac contours were outlined on each patient's simulation X-ray by 4 different raters, and the mean heart dose was estimated as the percentage of the cardiac contour within the radiation field multiplied by the prescribed mediastinal dose and divided by a correction factor obtained by comparison with individual CT-based dosimetry. Results: According to the simulation X-ray method, the medians of the mean heart doses obtained from the cardiac contours outlined by the 4 raters were 30 Gy, 30 Gy, 31 Gy, and 31 Gy, respectively, following prescribed mediastinal doses of 25-42 Gy. The absolute-agreement intraclass correlation coefficient was 0.93 (95% confidence interval 0.85-0.97), indicating excellent agreement. Mean heart dose was 30.4 Gy with the simulation X-ray method, versus 30.2 Gy with the representative CT-based dosimetry, and the between-method absolute-agreement intraclass correlation coefficient was 0.87 (95% confidence interval 0.80-0.95), indicating good agreement between the two methods. Conclusion: Estimating mean heart dose from radiation therapy simulation X-rays is reproducible and fast, takes individual anatomy into account, and yields results comparable to the labor

  13. Advanced scientific computational methods and their applications to nuclear technologies. (4) Overview of scientific computational methods, introduction of continuum simulation methods and their applications (4)

    International Nuclear Information System (INIS)

    Sekimura, Naoto; Okita, Taira

    2006-01-01

    Scientific computational methods have advanced remarkably with the progress of nuclear development. They have played the role of weft connecting each realm of nuclear engineering and then an introductory course of advanced scientific computational methods and their applications to nuclear technologies were prepared in serial form. This is the fourth issue showing the overview of scientific computational methods with the introduction of continuum simulation methods and their applications. Simulation methods on physical radiation effects on materials are reviewed based on the process such as binary collision approximation, molecular dynamics, kinematic Monte Carlo method, reaction rate method and dislocation dynamics. (T. Tanaka)

  14. Application of Conjugate Gradient methods to tidal simulation

    Science.gov (United States)

    Barragy, E.; Carey, G.F.; Walters, R.A.

    1993-01-01

    A harmonic decomposition technique is applied to the shallow water equations to yield a complex, nonsymmetric, nonlinear, Helmholtz type problem for the sea surface and an accompanying complex, nonlinear diagonal problem for the velocities. The equation for the sea surface is linearized using successive approximation and then discretized with linear, triangular finite elements. The study focuses on applying iterative methods to solve the resulting complex linear systems. The comparative evaluation includes both standard iterative methods for the real subsystems and complex versions of the well known Bi-Conjugate Gradient and Bi-Conjugate Gradient Squared methods. Several Incomplete LU type preconditioners are discussed, and the effects of node ordering, rejection strategy, domain geometry and Coriolis parameter (affecting asymmetry) are investigated. Implementation details for the complex case are discussed. Performance studies are presented and comparisons made with a frontal solver. ?? 1993.

  15. Hybrid statistics-simulations based method for atom-counting from ADF STEM images

    Energy Technology Data Exchange (ETDEWEB)

    De wael, Annelies, E-mail: annelies.dewael@uantwerpen.be [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); De Backer, Annick [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Jones, Lewys; Nellist, Peter D. [Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Van Aert, Sandra, E-mail: sandra.vanaert@uantwerpen.be [Electron Microscopy for Materials Science (EMAT), University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium)

    2017-06-15

    A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials. - Highlights: • A hybrid method for atom-counting from ADF STEM images is introduced. • Image simulations are incorporated into a statistical framework in a reliable manner. • Limits of the existing methods for atom-counting are far exceeded. • Reliable counting results from an experimental low dose image are obtained. • Progress towards reliable quantitative analysis of beam-sensitive materials is made.

  16. Biasing transition rate method based on direct MC simulation for probabilistic safety assessment

    Institute of Scientific and Technical Information of China (English)

    Xiao-Lei Pan; Jia-Qun Wang; Run Yuan; Fang Wang; Han-Qing Lin; Li-Qin Hu; Jin Wang

    2017-01-01

    Direct Monte Carlo (MC) simulation is a powerful probabilistic safety assessment method for accounting dynamics of the system.But it is not efficient at simulating rare events.A biasing transition rate method based on direct MC simulation is proposed to solve the problem in this paper.This method biases transition rates of the components by adding virtual components to them in series to increase the occurrence probability of the rare event,hence the decrease in the variance of MC estimator.Several cases are used to benchmark this method.The results show that the method is effective at modeling system failure and is more efficient at collecting evidence of rare events than the direct MC simulation.The performance is greatly improved by the biasing transition rate method.

  17. An efficient parallel simulation of unsteady blood flows in patient-specific pulmonary artery.

    Science.gov (United States)

    Kong, Fande; Kheyfets, Vitaly; Finol, Ender; Cai, Xiao-Chuan

    2018-04-01

    Simulation of blood flows in the pulmonary artery provides some insight into certain diseases by examining the relationship between some continuum metrics, eg, the wall shear stress acting on the vascular endothelium, which responds to flow-induced mechanical forces by releasing vasodilators/constrictors. V. Kheyfets, in his previous work, studies numerically a patient-specific pulmonary circulation to show that decreasing wall shear stress is correlated with increasing pulmonary vascular impedance. In this paper, we develop a scalable parallel algorithm based on domain decomposition methods to investigate an unsteady model with patient-specific pulsatile waveforms as the inlet boundary condition. The unsteady model offers tremendously more information about the dynamic behavior of the flow field, but computationally speaking, the simulation is a lot more expensive since a problem which is similar to the steady-state problem has to be solved many times, and therefore, the traditional sequential approach is not suitable anymore. We show computationally that simulations using the proposed parallel approach with up to 10 000 processor cores can be obtained with much reduced compute time. This makes the technology potentially usable for the routine study of the dynamic behavior of blood flows in the pulmonary artery, in particular, the changes of the blood flows and the wall shear stress in the spatial and temporal dimensions. Copyright © 2017 John Wiley & Sons, Ltd.

  18. High-fidelity haptic and visual rendering for patient-specific simulation of temporal bone surgery.

    Science.gov (United States)

    Chan, Sonny; Li, Peter; Locketz, Garrett; Salisbury, Kenneth; Blevins, Nikolas H

    2016-12-01

    Medical imaging techniques provide a wealth of information for surgical preparation, but it is still often the case that surgeons are examining three-dimensional pre-operative image data as a series of two-dimensional images. With recent advances in visual computing and interactive technologies, there is much opportunity to provide surgeons an ability to actively manipulate and interpret digital image data in a surgically meaningful way. This article describes the design and initial evaluation of a virtual surgical environment that supports patient-specific simulation of temporal bone surgery using pre-operative medical image data. Computational methods are presented that enable six degree-of-freedom haptic feedback during manipulation, and that simulate virtual dissection according to the mechanical principles of orthogonal cutting and abrasive wear. A highly efficient direct volume renderer simultaneously provides high-fidelity visual feedback during surgical manipulation of the virtual anatomy. The resulting virtual surgical environment was assessed by evaluating its ability to replicate findings in the operating room, using pre-operative imaging of the same patient. Correspondences between surgical exposure, anatomical features, and the locations of pathology were readily observed when comparing intra-operative video with the simulation, indicating the predictive ability of the virtual surgical environment.

  19. Simulation of electrically driven jet using Chebyshev collocation method

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The model of electrically driven jet is governed by a series of quasi 1D dimensionless partial differential equations(PDEs).Following the method of lines,the Chebyshev collocation method is employed to discretize the PDEs and obtain a system of differential-algebraic equations(DAEs).By differentiating constrains in DAEs twice,the system is transformed into a set of ordinary differential equations(ODEs) with invariants.Then the implicit differential equations solver "ddaskr" is used to solve the ODEs and ...

  20. FDTD method using for electrodynamic simulation of resonator accelerating structures

    International Nuclear Information System (INIS)

    Vorogushin, M.F.; Svistunov, Yu.A.; Chetverikov, I.O.; Malyshev, V.N.; Malyukhov, M.V.

    2000-01-01

    The finite difference method in the time area (FDTD) makes it possible to model both stationary and nonstationary processes, originating by the beam and field interaction. Possibilities of the method by modeling the fields in the resonant accelerating structures are demonstrated. The possibility of considering the transition processes is important besides the solution of the problem on determination of frequencies and distribution in the space of the resonators oscillations proper types. The program presented makes it possible to obtain practical results for modeling accelerating structures on personal computers [ru

  1. Understanding the impact of simulated patients on health care learners' communication skills: a systematic review.

    Science.gov (United States)

    Kaplonyi, Jessica; Bowles, Kelly-Ann; Nestel, Debra; Kiegaldie, Debra; Maloney, Stephen; Haines, Terry; Williams, Cylie

    2017-12-01

    Effective communication skills are at the core of good health care. Simulated patients (SPs) are increasingly engaged as an interactive means of teaching, applying and practising communication skills with immediate feedback. There is a large body of research into the use of manikin-based simulation but a gap exists in the body of research on the effectiveness of SP-based education to teach communication skills that impact patient outcomes. The aim of this systematic review was to critically analyse the existing research, investigating whether SP-based communication skills training improves learner-patient communication, how communication skill improvement is measured, and who measures these improvements. The databases Medline, ProQuest (Health & Medical Complete, Nursing and Allied Health Source) and CINAHL (EBSCOhost) Education Resources Information Centre (ERIC) were searched for articles that investigated the effects of SP-based education on the communication skills of medical, nursing and allied health learners. There were 60 studies included in the review. Only two studies reported direct patient outcomes, one reporting some negative impact, and no studies included an economic analysis. Many studies reported statistically significant third-party ratings of improved communication effectiveness following SP-based education; however, studies were unable to be pooled for meta-analysis because of the outcome collection methods. There were a small number of studies comparing SP with no training at all and there were no differences between communication skills, contradicting the results from studies reporting benefits. Of the 60 studies included for analysis, 54 (90%) met the minimum quality score of 7/11, with four articles (7%) scoring 11/11. SP-based education is widely accepted as a valuable and effective means of teaching communication skills but there is limited evidence of how this translates to patient outcomes and no indication of economic benefit for this

  2. Numerical simulation methods for phase-transitional flow

    NARCIS (Netherlands)

    Pecenko, A.

    2010-01-01

    The object of the present dissertation is a numerical study of multiphase flow of one fluid component. In particular, the research described in this thesis focuses on the development of numerical methods that are based on a diffuse-interface model (DIM). With this approach, the modeling problem

  3. Clearance gap flow: Simulations by discontinuous Galerkin method and experiments

    Czech Academy of Sciences Publication Activity Database

    Hála, Jindřich; Luxa, Martin; Bublík, O.; Prausová, H.; Vimmr, J.

    2016-01-01

    Roč. 92, May (2016), 02073-02073 ISSN 2100-014X. [EFM14 – Experimental Fluid Mechanics 2014. Český Krumlov, 18.11.2014-21.11.2014] Institutional support: RVO:61388998 Keywords : compressible fluid flow * narrow channel flow * discontinuous Galerkin finite element method Subject RIV: BK - Fluid Dynamics

  4. TreePM Method for Two-Dimensional Cosmological Simulations ...

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    We discuss the integration of the equations of motion that we use in the 2d TreePM code in section 7. .... spaced values of r in order to keep interpolation errors in control. .... hence we cannot use the usual leap-frog method. We recast the ...

  5. A Simulator to Enhance Teaching and Learning of Mining Methods ...

    African Journals Online (AJOL)

    Audio visual education that incorporates devices and materials which involve sight, sound, or both has become a sine qua non in recent times in the teaching and learning process. An automated physical model of mining methods aided with video instructions was designed and constructed by harnessing locally available ...

  6. Novel bed integrated ventilation method for hospital patient rooms

    DEFF Research Database (Denmark)

    Bivolarova, Mariya Petrova; Melikov, Arsen Krikor; Kokora, Monika

    2014-01-01

    This study presents a novel method for advanced ventilation of hospital wards leading to improved air quality at reduced ventilation rate. The idea is to evacuate the bio-effluents generated from patients’ body by local exhaustion before being spread in the room. This concept was realized by using...... a mattress having a suction opening from which bio-effluents generated from human body are exhausted. Experiments were conducted in a full-scale two-bed hospital room mock-up, 4.7 x 5.3 x 2.6 m3 (W x L x H). Only one of the patients’ beds was equipped with the ventilated mattress. The room was air...... conditioned via mixing total volume ventilation system supplying air through a ceiling mounted diffuser. All experiments were performed at room air temperature of 23ºC. A thermal manikin was used to simulate a polluting patient on the bed equipped with the ventilated mattress. Two heated dummies were used...

  7. Study of Physiological Responses to Acute Carbon Monoxide Exposure with a Human Patient Simulator

    Science.gov (United States)

    Cesari, Whitney A.; Caruso, Dominique M.; Zyka, Enela L.; Schroff, Stuart T.; Evans, Charles H., Jr.; Hyatt, Jon-Philippe K.

    2006-01-01

    Human patient simulators are widely used to train health professionals and students in a clinical setting, but they also can be used to enhance physiology education in a laboratory setting. Our course incorporates the human patient simulator for experiential learning in which undergraduate university juniors and seniors are instructed to design,…

  8. A new method to estimate heat source parameters in gas metal arc welding simulation process

    International Nuclear Information System (INIS)

    Jia, Xiaolei; Xu, Jie; Liu, Zhaoheng; Huang, Shaojie; Fan, Yu; Sun, Zhi

    2014-01-01

    Highlights: •A new method for accurate simulation of heat source parameters was presented. •The partial least-squares regression analysis was recommended in the method. •The welding experiment results verified accuracy of the proposed method. -- Abstract: Heat source parameters were usually recommended by experience in welding simulation process, which induced error in simulation results (e.g. temperature distribution and residual stress). In this paper, a new method was developed to accurately estimate heat source parameters in welding simulation. In order to reduce the simulation complexity, a sensitivity analysis of heat source parameters was carried out. The relationships between heat source parameters and welding pool characteristics (fusion width (W), penetration depth (D) and peak temperature (T p )) were obtained with both the multiple regression analysis (MRA) and the partial least-squares regression analysis (PLSRA). Different regression models were employed in each regression method. Comparisons of both methods were performed. A welding experiment was carried out to verify the method. The results showed that both the MRA and the PLSRA were feasible and accurate for prediction of heat source parameters in welding simulation. However, the PLSRA was recommended for its advantages of requiring less simulation data

  9. Bayesian statistic methods and theri application in probabilistic simulation models

    Directory of Open Access Journals (Sweden)

    Orietta Zaniolo

    2006-03-01

    Full Text Available Significant advances in the management of hypercholesterolemia have been made possible by the development of statins, 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA reductase inhibitors. More recently, statins have demonstrated benefit in primary and secondary prevention of cardiovascular disease also in patients without hypercholesterolemia. Therefore statins help to reduce the impact of cardiovascular disease on morbility, mortality and social costs. Statins inhibit HMG-CoA reductase competitively, reduce LDL levels more than other cholesterol-lowering drugs, and lower triglyceride levels in hypertriglyceridemic patients. Prescribing statins as first line therapy in management of hypercholesterolemia as a part of a more comprehensive prevention program of cardiovascular disease is widely recommended by international guidelines (e.g. National Cholesterol Education Program - NCEP - Adult Treatment Panel - ATP- III reports. Currently in Italy there are five available statins: atorvastatin, fluvastatin, pravastatin, rosuvastatin and simvastatin; each of them presents some differences in physical and chemical characteristics (solubility, pharmacokinetics (absorption, proteic binding, metabolism and excretion and pharmacodinamics (pleiotropic effects. Compared to other statins, fluvastatin extended-release (RP 80 mg provides an equal efficacy in lowering total cholesterol and low-density lipoprotein cholesterol (LDL-C, with an important action on triglyceride (TG levels and superior increases in HDL-C levels, reducing the incidence of major adverse cardiac events (MACE. Aim of this study is to outline an updated therapeutic and pharmacoeconomic profile of fluvastatin, particularly regarding extended-release (RP 80 mg formulation.

  10. Partial Variance of Increments Method in Solar Wind Observations and Plasma Simulations

    Science.gov (United States)

    Greco, A.; Matthaeus, W. H.; Perri, S.; Osman, K. T.; Servidio, S.; Wan, M.; Dmitruk, P.

    2018-02-01

    The method called "PVI" (Partial Variance of Increments) has been increasingly used in analysis of spacecraft and numerical simulation data since its inception in 2008. The purpose of the method is to study the kinematics and formation of coherent structures in space plasmas, a topic that has gained considerable attention, leading the development of identification methods, observations, and associated theoretical research based on numerical simulations. This review paper will summarize key features of the method and provide a synopsis of the main results obtained by various groups using the method. This will enable new users or those considering methods of this type to find details and background collected in one place.

  11. Simple method to estimate mean heart dose from Hodgkin lymphoma radiation therapy according to simulation X-rays.

    Science.gov (United States)

    van Nimwegen, Frederika A; Cutter, David J; Schaapveld, Michael; Rutten, Annemarieke; Kooijman, Karen; Krol, Augustinus D G; Janus, Cécile P M; Darby, Sarah C; van Leeuwen, Flora E; Aleman, Berthe M P

    2015-05-01

    To describe a new method to estimate the mean heart dose for Hodgkin lymphoma patients treated several decades ago, using delineation of the heart on radiation therapy simulation X-rays. Mean heart dose is an important predictor for late cardiovascular complications after Hodgkin lymphoma (HL) treatment. For patients treated before the era of computed tomography (CT)-based radiotherapy planning, retrospective estimation of radiation dose to the heart can be labor intensive. Patients for whom cardiac radiation doses had previously been estimated by reconstruction of individual treatments on representative CT data sets were selected at random from a case-control study of 5-year Hodgkin lymphoma survivors (n=289). For 42 patients, cardiac contours were outlined on each patient's simulation X-ray by 4 different raters, and the mean heart dose was estimated as the percentage of the cardiac contour within the radiation field multiplied by the prescribed mediastinal dose and divided by a correction factor obtained by comparison with individual CT-based dosimetry. According to the simulation X-ray method, the medians of the mean heart doses obtained from the cardiac contours outlined by the 4 raters were 30 Gy, 30 Gy, 31 Gy, and 31 Gy, respectively, following prescribed mediastinal doses of 25-42 Gy. The absolute-agreement intraclass correlation coefficient was 0.93 (95% confidence interval 0.85-0.97), indicating excellent agreement. Mean heart dose was 30.4 Gy with the simulation X-ray method, versus 30.2 Gy with the representative CT-based dosimetry, and the between-method absolute-agreement intraclass correlation coefficient was 0.87 (95% confidence interval 0.80-0.95), indicating good agreement between the two methods. Estimating mean heart dose from radiation therapy simulation X-rays is reproducible and fast, takes individual anatomy into account, and yields results comparable to the labor-intensive representative CT-based method. This simpler method may produce a

  12. Methods for Factor Screening in Computer Simulation Experiments

    Science.gov (United States)

    1979-03-01

    of the dat-a In a-space, impacto the variable selection problem s ign if Lrast ly. S-arch-type variable selection methods include the all-po"sible...i.iv 41.1 ti * n wt- -iu’pt-v c C it st’vt’re mu It ico11 inear it v is pro-crtnt Lind. , ii;.qt4pai tlv * Iti’lt- c- j c. tic j icivnt, art, verv

  13. Empirical method for simulation of water tables by digital computers

    International Nuclear Information System (INIS)

    Carnahan, C.L.; Fenske, P.R.

    1975-09-01

    An empirical method is described for computing a matrix of water-table elevations from a matrix of topographic elevations and a set of observed water-elevation control points which may be distributed randomly over the area of interest. The method is applicable to regions, such as the Great Basin, where the water table can be assumed to conform to a subdued image of overlying topography. A first approximation to the water table is computed by smoothing a matrix of topographic elevations and adjusting each node of the smoothed matrix according to a linear regression between observed water elevations and smoothed topographic elevations. Each observed control point is assumed to exert a radially decreasing influence on the first approximation surface. The first approximation is then adjusted further to conform to observed water-table elevations near control points. Outside the domain of control, the first approximation is assumed to represent the most probable configuration of the water table. The method has been applied to the Nevada Test Site and the Hot Creek Valley areas in Nevada

  14. Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

    Directory of Open Access Journals (Sweden)

    Shankarjee Krishnamoorthi

    Full Text Available We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

  15. Simulation Methods and Validation Criteria for Modeling Cardiac Ventricular Electrophysiology.

    Science.gov (United States)

    Krishnamoorthi, Shankarjee; Perotti, Luigi E; Borgstrom, Nils P; Ajijola, Olujimi A; Frid, Anna; Ponnaluri, Aditya V; Weiss, James N; Qu, Zhilin; Klug, William S; Ennis, Daniel B; Garfinkel, Alan

    2014-01-01

    We describe a sequence of methods to produce a partial differential equation model of the electrical activation of the ventricles. In our framework, we incorporate the anatomy and cardiac microstructure obtained from magnetic resonance imaging and diffusion tensor imaging of a New Zealand White rabbit, the Purkinje structure and the Purkinje-muscle junctions, and an electrophysiologically accurate model of the ventricular myocytes and tissue, which includes transmural and apex-to-base gradients of action potential characteristics. We solve the electrophysiology governing equations using the finite element method and compute both a 6-lead precordial electrocardiogram (ECG) and the activation wavefronts over time. We are particularly concerned with the validation of the various methods used in our model and, in this regard, propose a series of validation criteria that we consider essential. These include producing a physiologically accurate ECG, a correct ventricular activation sequence, and the inducibility of ventricular fibrillation. Among other components, we conclude that a Purkinje geometry with a high density of Purkinje muscle junctions covering the right and left ventricular endocardial surfaces as well as transmural and apex-to-base gradients in action potential characteristics are necessary to produce ECGs and time activation plots that agree with physiological observations.

  16. Computer codes and methods for simulating accelerator driven systems

    International Nuclear Information System (INIS)

    Sartori, E.; Byung Chan Na

    2003-01-01

    A large set of computer codes and associated data libraries have been developed by nuclear research and industry over the past half century. A large number of them are in the public domain and can be obtained under agreed conditions from different Information Centres. The areas covered comprise: basic nuclear data and models, reactor spectra and cell calculations, static and dynamic reactor analysis, criticality, radiation shielding, dosimetry and material damage, fuel behaviour, safety and hazard analysis, heat conduction and fluid flow in reactor systems, spent fuel and waste management (handling, transportation, and storage), economics of fuel cycles, impact on the environment of nuclear activities etc. These codes and models have been developed mostly for critical systems used for research or power generation and other technological applications. Many of them have not been designed for accelerator driven systems (ADS), but with competent use, they can be used for studying such systems or can form the basis for adapting existing methods to the specific needs of ADS's. The present paper describes the types of methods, codes and associated data available and their role in the applications. It provides Web addresses for facilitating searches for such tools. Some indications are given on the effect of non appropriate or 'blind' use of existing tools to ADS. Reference is made to available experimental data that can be used for validating the methods use. Finally, some international activities linked to the different computational aspects are described briefly. (author)

  17. Methods and Simulations of Muon Tomography and Reconstruction

    Science.gov (United States)

    Schreiner, Henry Fredrick, III

    This dissertation investigates imaging with cosmic ray muons using scintillator-based portable particle detectors, and covers a variety of the elements required for the detectors to operate and take data, from the detector internal communications and software algorithms to a measurement to allow accurate predictions of the attenuation of physical targets. A discussion of the tracking process for the three layer helical design developed at UT Austin is presented, with details of the data acquisition system, and the highly efficient data format. Upgrades to this system provide a stable system for taking images in harsh or inaccessible environments, such as in a remote jungle in Belize. A Geant4 Monte Carlo simulation was used to develop our understanding of the efficiency of the system, as well as to make predictions for a variety of different targets. The projection process is discussed, with a high-speed algorithm for sweeping a plane through data in near real time, to be used in applications requiring a search through space for target discovery. Several other projections and a foundation of high fidelity 3D reconstructions are covered. A variable binning scheme for rapidly varying statistics over portions of an image plane is also presented and used. A discrepancy in our predictions and the observed attenuation through smaller targets is shown, and it is resolved with a new measurement of low energy spectrum, using a specially designed enclosure to make a series of measurements underwater. This provides a better basis for understanding the images of small amounts of materials, such as for thin cover materials.

  18. Read margin analysis of crossbar arrays using the cell-variability-aware simulation method

    Science.gov (United States)

    Sun, Wookyung; Choi, Sujin; Shin, Hyungsoon

    2018-02-01

    This paper proposes a new concept of read margin analysis of crossbar arrays using cell-variability-aware simulation. The size of the crossbar array should be considered to predict the read margin characteristic of the crossbar array because the read margin depends on the number of word lines and bit lines. However, an excessively high-CPU time is required to simulate large arrays using a commercial circuit simulator. A variability-aware MATLAB simulator that considers independent variability sources is developed to analyze the characteristics of the read margin according to the array size. The developed MATLAB simulator provides an effective method for reducing the simulation time while maintaining the accuracy of the read margin estimation in the crossbar array. The simulation is also highly efficient in analyzing the characteristic of the crossbar memory array considering the statistical variations in the cell characteristics.

  19. IMPROVING MEDICAL EDUCATION: SIMULATING CHANGES IN PATIENT ANATOMY USING DYNAMIC HAPTIC FEEDBACK

    OpenAIRE

    Yovanoff, Mary; Pepley, David; Mirkin, Katelin; Moore, Jason; Han, David; Miller, Scarlett

    2016-01-01

    Virtual simulation is an emerging field in medical education. Research suggests that simulation reduces complication rates and improves learning gains for medical residents. One benefit of simulators is their allowance for more realistic and dynamic patient anatomies. While potentially useful throughout medical education, few studies have explored the impact of dynamic haptic simulators on medical training. In light of this research void, this study was developed to examine how a Dynamic-Hapt...

  20. A simulation of portable PET with a new geometric image reconstruction method

    Energy Technology Data Exchange (ETDEWEB)

    Kawatsu, Shoji [Department of Radiology, Kyoritu General Hospital, 4-33 Go-bancho, Atsuta-ku, Nagoya-shi, Aichi 456 8611 (Japan): Department of Brain Science and Molecular Imaging, National Institute for Longevity Sciences, National Center for Geriatrics and Gerontology, 36-3, Gengo Moriaka-cho, Obu-shi, Aichi 474 8522 (Japan)]. E-mail: b6rgw@fantasy.plala.or.jp; Ushiroya, Noboru [Department of General Education, Wakayama National College of Technology, 77 Noshima, Nada-cho, Gobo-shi, Wakayama 644 0023 (Japan)

    2006-12-20

    A new method is proposed for three-dimensional positron emission tomography image reconstruction. The method uses the elementary geometric property of line of response whereby two lines of response, which originate from radioactive isotopes in the same position, lie within a few millimeters distance of each other. The method differs from the filtered back projection method and the iterative reconstruction method. The method is applied to a simulation of portable positron emission tomography.

  1. Simulation-based patient flow analysis in an endoscopy unit

    DEFF Research Database (Denmark)

    Koo, Pyung-Hoi; Nielsen, Karl Brian; Jang, Jaejin

    2010-01-01

    One of the major elements in improving efficiency of healthcare services is patient flow. Patients require a variety of healthcare resources as they receive healthcare services. Poor management of patient flow results in long waiting time of patients, under/over utilization of medical resources......, low quality of care and high healthcare cost. This article addresses patient flow problems at a Gastrointestinal endoscopy unit. We attempt to analyze the main factors that contribute to the inefficient patient flow and process bottlenecks and to propose efficient patient scheduling and staff...

  2. Method and Tool for Design Process Navigation and Automatic Generation of Simulation Models for Manufacturing Systems

    Science.gov (United States)

    Nakano, Masaru; Kubota, Fumiko; Inamori, Yutaka; Mitsuyuki, Keiji

    Manufacturing system designers should concentrate on designing and planning manufacturing systems instead of spending their efforts on creating the simulation models to verify the design. This paper proposes a method and its tool to navigate the designers through the engineering process and generate the simulation model automatically from the design results. The design agent also supports collaborative design projects among different companies or divisions with distributed engineering and distributed simulation techniques. The idea was implemented and applied to a factory planning process.

  3. Simulation of the 2-dimensional Drude’s model using molecular dynamics method

    Energy Technology Data Exchange (ETDEWEB)

    Naa, Christian Fredy; Amin, Aisyah; Ramli,; Suprijadi,; Djamal, Mitra [Theoretical High Energy Physics and Instrumentation Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Wahyoedi, Seramika Ari; Viridi, Sparisoma, E-mail: viridi@cphys.fi.itb.ac.id [Nuclear and Biophysics Research Division, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2015-04-16

    In this paper, we reported the results of the simulation of the electronic conduction in solids. The simulation is based on the Drude’s models by applying molecular dynamics (MD) method, which uses the fifth-order predictor-corrector algorithm. A formula of the electrical conductivity as a function of lattice length and ion diameter τ(L, d) cand be obtained empirically based on the simulation results.

  4. SPACE CHARGE SIMULATION METHODS INCORPORATED IN SOME MULTI - PARTICLE TRACKING CODES AND THEIR RESULTS COMPARISON

    International Nuclear Information System (INIS)

    BEEBE - WANG, J.; LUCCIO, A.U.; D IMPERIO, N.; MACHIDA, S.

    2002-01-01

    Space charge in high intensity beams is an important issue in accelerator physics. Due to the complicity of the problems, the most effective way of investigating its effect is by computer simulations. In the resent years, many space charge simulation methods have been developed and incorporated in various 2D or 3D multi-particle-tracking codes. It has becoming necessary to benchmark these methods against each other, and against experimental results. As a part of global effort, we present our initial comparison of the space charge methods incorporated in simulation codes ORBIT++, ORBIT and SIMPSONS. In this paper, the methods included in these codes are overviewed. The simulation results are presented and compared. Finally, from this study, the advantages and disadvantages of each method are discussed

  5. SPACE CHARGE SIMULATION METHODS INCORPORATED IN SOME MULTI - PARTICLE TRACKING CODES AND THEIR RESULTS COMPARISON.

    Energy Technology Data Exchange (ETDEWEB)

    BEEBE - WANG,J.; LUCCIO,A.U.; D IMPERIO,N.; MACHIDA,S.

    2002-06-03

    Space charge in high intensity beams is an important issue in accelerator physics. Due to the complicity of the problems, the most effective way of investigating its effect is by computer simulations. In the resent years, many space charge simulation methods have been developed and incorporated in various 2D or 3D multi-particle-tracking codes. It has becoming necessary to benchmark these methods against each other, and against experimental results. As a part of global effort, we present our initial comparison of the space charge methods incorporated in simulation codes ORBIT++, ORBIT and SIMPSONS. In this paper, the methods included in these codes are overviewed. The simulation results are presented and compared. Finally, from this study, the advantages and disadvantages of each method are discussed.

  6. Effect of Advanced Trauma Life Support program on medical interns' performance in simulated trauma patient management.

    Science.gov (United States)

    Ahmadi, Koorosh; Sedaghat, Mohammad; Safdarian, Mahdi; Hashemian, Amir-Masoud; Nezamdoust, Zahra; Vaseie, Mohammad; Rahimi-Movaghar, Vafa

    2013-01-01

    Since appropriate and time-table methods in trauma care have an important impact on patients'outcome, we evaluated the effect of Advanced Trauma Life Support (ATLS) program on medical interns' performance in simulated trauma patient management. A descriptive and analytical study before and after the training was conducted on 24 randomly selected undergraduate medical interns from Imam Reza Hospital in Mashhad, Iran. On the first day, we assessed interns' clinical knowledge and their practical skill performance in confronting simulated trauma patients. After 2 days of ATLS training, we performed the same study and evaluated their score again on the fourth day. The two findings, pre- and post- ATLS periods, were compared through SPSS version 15.0 software. P values less than 0.05 were considered statistically significant. Our findings showed that interns'ability in all the three tasks improved after the training course. On the fourth day after training, there was a statistically significant increase in interns' clinical knowledge of ATLS procedures, the sequence of procedures and skill performance in trauma situations (P less than 0.001, P equal to 0.016 and P equal to 0.01 respectively). ATLS course has an important role in increasing clinical knowledge and practical skill performance of trauma care in medical interns.

  7. Using a computer simulation for teaching communication skills: A blinded multisite mixed methods randomized controlled trial.

    Science.gov (United States)

    Kron, Frederick W; Fetters, Michael D; Scerbo, Mark W; White, Casey B; Lypson, Monica L; Padilla, Miguel A; Gliva-McConvey, Gayle A; Belfore, Lee A; West, Temple; Wallace, Amelia M; Guetterman, Timothy C; Schleicher, Lauren S; Kennedy, Rebecca A; Mangrulkar, Rajesh S; Cleary, James F; Marsella, Stacy C; Becker, Daniel M

    2017-04-01

    To assess advanced communication skills among second-year medical students exposed either to a computer simulation (MPathic-VR) featuring virtual humans, or to a multimedia computer-based learning module, and to understand each group's experiences and learning preferences. A single-blinded, mixed methods, randomized, multisite trial compared MPathic-VR (N=210) to computer-based learning (N=211). Primary outcomes: communication scores during repeat interactions with MPathic-VR's intercultural and interprofessional communication scenarios and scores on a subsequent advanced communication skills objective structured clinical examination (OSCE). Multivariate analysis of variance was used to compare outcomes. student attitude surveys and qualitative assessments of their experiences with MPathic-VR or computer-based learning. MPathic-VR-trained students improved their intercultural and interprofessional communication performance between their first and second interactions with each scenario. They also achieved significantly higher composite scores on the OSCE than computer-based learning-trained students. Attitudes and experiences were more positive among students trained with MPathic-VR, who valued its providing immediate feedback, teaching nonverbal communication skills, and preparing them for emotion-charged patient encounters. MPathic-VR was effective in training advanced communication skills and in enabling knowledge transfer into a more realistic clinical situation. MPathic-VR's virtual human simulation offers an effective and engaging means of advanced communication training. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  8. The Monte Carlo Simulation Method for System Reliability and Risk Analysis

    CERN Document Server

    Zio, Enrico

    2013-01-01

    Monte Carlo simulation is one of the best tools for performing realistic analysis of complex systems as it allows most of the limiting assumptions on system behavior to be relaxed. The Monte Carlo Simulation Method for System Reliability and Risk Analysis comprehensively illustrates the Monte Carlo simulation method and its application to reliability and system engineering. Readers are given a sound understanding of the fundamentals of Monte Carlo sampling and simulation and its application for realistic system modeling.   Whilst many of the topics rely on a high-level understanding of calculus, probability and statistics, simple academic examples will be provided in support to the explanation of the theoretical foundations to facilitate comprehension of the subject matter. Case studies will be introduced to provide the practical value of the most advanced techniques.   This detailed approach makes The Monte Carlo Simulation Method for System Reliability and Risk Analysis a key reference for senior undergra...

  9. 3D simulation of friction stir welding based on movable cellular automaton method

    Science.gov (United States)

    Eremina, Galina M.

    2017-12-01

    The paper is devoted to a 3D computer simulation of the peculiarities of material flow taking place in friction stir welding (FSW). The simulation was performed by the movable cellular automaton (MCA) method, which is a representative of particle methods in mechanics. Commonly, the flow of material in FSW is simulated based on computational fluid mechanics, assuming the material as continuum and ignoring its structure. The MCA method considers a material as an ensemble of bonded particles. The rupture of interparticle bonds and the formation of new bonds enable simulations of crack nucleation and healing as well as mas mixing and microwelding. The simulation results showed that using pins of simple shape (cylinder, cone, and pyramid) without a shoulder results in small displacements of plasticized material in workpiece thickness directions. Nevertheless, the optimal ratio of longitudinal velocity to rotational speed makes it possible to transport the welded material around the pin several times and to produce a joint of good quality.

  10. Development and simulation of various methods for neutron activation analysis

    International Nuclear Information System (INIS)

    Otgooloi, B.

    1993-01-01

    Simple methods for neutron activation analysis have been developed. The results on the studies of installation for determination of fluorine in fluorite ores directly on the lorry by fast neutron activation analysis have been shown. Nitrogen in organic materials was shown by N 14 and N 15 activation. The description of the new equipment 'FLUORITE' for fluorate factory have been shortly given. Pu and Be isotope in organic materials, including in wheat, was measured. 25 figs, 19 tabs. (Author, Translated by J.U)

  11. Spectral Element Method for the Simulation of Unsteady Compressible Flows

    Science.gov (United States)

    Diosady, Laslo Tibor; Murman, Scott M.

    2013-01-01

    This work uses a discontinuous-Galerkin spectral-element method (DGSEM) to solve the compressible Navier-Stokes equations [1{3]. The inviscid ux is computed using the approximate Riemann solver of Roe [4]. The viscous fluxes are computed using the second form of Bassi and Rebay (BR2) [5] in a manner consistent with the spectral-element approximation. The method of lines with the classical 4th-order explicit Runge-Kutta scheme is used for time integration. Results for polynomial orders up to p = 15 (16th order) are presented. The code is parallelized using the Message Passing Interface (MPI). The computations presented in this work are performed using the Sandy Bridge nodes of the NASA Pleiades supercomputer at NASA Ames Research Center. Each Sandy Bridge node consists of 2 eight-core Intel Xeon E5-2670 processors with a clock speed of 2.6Ghz and 2GB per core memory. On a Sandy Bridge node the Tau Benchmark [6] runs in a time of 7.6s.

  12. An adaptative finite element method for turbulent flow simulations

    International Nuclear Information System (INIS)

    Arnoux-Guisse, F.; Bonnin, O.; Leal de Sousa, L.; Nicolas, G.

    1995-05-01

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

  13. Heterogeneous Rock Simulation Using DIP-Micromechanics-Statistical Methods

    Directory of Open Access Journals (Sweden)

    H. Molladavoodi

    2018-01-01

    Full Text Available Rock as a natural material is heterogeneous. Rock material consists of minerals, crystals, cement, grains, and microcracks. Each component of rock has a different mechanical behavior under applied loading condition. Therefore, rock component distribution has an important effect on rock mechanical behavior, especially in the postpeak region. In this paper, the rock sample was studied by digital image processing (DIP, micromechanics, and statistical methods. Using image processing, volume fractions of the rock minerals composing the rock sample were evaluated precisely. The mechanical properties of the rock matrix were determined based on upscaling micromechanics. In order to consider the rock heterogeneities effect on mechanical behavior, the heterogeneity index was calculated in a framework of statistical method. A Weibull distribution function was fitted to the Young modulus distribution of minerals. Finally, statistical and Mohr–Coulomb strain-softening models were used simultaneously as a constitutive model in DEM code. The acoustic emission, strain energy release, and the effect of rock heterogeneities on the postpeak behavior process were investigated. The numerical results are in good agreement with experimental data.

  14. Simulation As a Method To Support Complex Organizational Transformations in Healthcare

    NARCIS (Netherlands)

    Rothengatter, D.C.F.; Katsma, Christiaan; van Hillegersberg, Jos

    2010-01-01

    In this paper we study the application of simulation as a method to support information system and process design in complex organizational transitions. We apply a combined use of a collaborative workshop approach with the use of a detailed and accurate graphical simulation model in a hospital that

  15. Discrete event simulation of crop operations in sweet pepper in support of work method innovation

    NARCIS (Netherlands)

    Ooster, van 't Bert; Aantjes, Wiger; Melamed, Z.

    2017-01-01

    Greenhouse Work Simulation, GWorkS, is a model that simulates crop operations in greenhouses for the purpose of analysing work methods. GWorkS is a discrete event model that approaches reality as a discrete stochastic dynamic system. GWorkS was developed and validated using cut-rose as a case

  16. An analytical method to simulate the H I 21-cm visibility signal for intensity mapping experiments

    Science.gov (United States)

    Sarkar, Anjan Kumar; Bharadwaj, Somnath; Marthi, Visweshwar Ram

    2018-01-01

    Simulations play a vital role in testing and validating H I 21-cm power spectrum estimation techniques. Conventional methods use techniques like N-body simulations to simulate the sky signal which is then passed through a model of the instrument. This makes it necessary to simulate the H I distribution in a large cosmological volume, and incorporate both the light-cone effect and the telescope's chromatic response. The computational requirements may be particularly large if one wishes to simulate many realizations of the signal. In this paper, we present an analytical method to simulate the H I visibility signal. This is particularly efficient if one wishes to simulate a large number of realizations of the signal. Our method is based on theoretical predictions of the visibility correlation which incorporate both the light-cone effect and the telescope's chromatic response. We have demonstrated this method by applying it to simulate the H I visibility signal for the upcoming Ooty Wide Field Array Phase I.

  17. Simulation-based investigation of the paired-gear method in cod-end selectivity studies

    DEFF Research Database (Denmark)

    Herrmann, Bent; Frandsen, Rikke; Holst, René

    2007-01-01

    In this paper, the paired-gear and covered cod-end methods for estimating the selectivity of trawl cod-ends are compared. A modified version of the cod-end selectivity simulator PRESEMO is used to simulate the data that would be collected from a paired-gear experiment where the test cod-end also ...

  18. Simulated annealing method for electronic circuits design: adaptation and comparison with other optimization methods; La methode du recuit simule pour la conception des circuits electroniques: adaptation et comparaison avec d`autres methodes d`optimisation

    Energy Technology Data Exchange (ETDEWEB)

    Berthiau, G

    1995-10-01

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

  19. Hybrid vortex simulations of wind turbines using a three-dimensional viscous-inviscid panel method

    DEFF Research Database (Denmark)

    Ramos García, Néstor; Hejlesen, Mads Mølholm; Sørensen, Jens Nørkær

    2017-01-01

    adirect calculation, whereas the contribution from the large downstream wake is calculated using a mesh-based method. Thehybrid method is first validated in detail against the well-known MEXICO experiment, using the direct filament method asa comparison. The second part of the validation includes a study......A hybrid filament-mesh vortex method is proposed and validated to predict the aerodynamic performance of wind turbinerotors and to simulate the resulting wake. Its novelty consists of using a hybrid method to accurately simulate the wakedownstream of the wind turbine while reducing...

  20. Some recent developments of the immersed interface method for flow simulation

    Science.gov (United States)

    Xu, Sheng

    2017-11-01

    The immersed interface method is a general methodology for solving PDEs subject to interfaces. In this talk, I will give an overview of some recent developments of the method toward the enhancement of its robustness for flow simulation. In particular, I will present with numerical results how to capture boundary conditions on immersed rigid objects, how to adopt interface triangulation in the method, and how to parallelize the method for flow with moving objects. With these developments, the immersed interface method can achieve accurate and efficient simulation of a flow involving multiple moving complex objects. Thanks to NSF for the support of this work under Grant NSF DMS 1320317.

  1. Research of Monte Carlo method used in simulation of different maintenance processes

    International Nuclear Information System (INIS)

    Zhao Siqiao; Liu Jingquan

    2011-01-01

    The paper introduces two kinds of Monte Carlo methods used in equipment life process simulation under the least maintenance: condition: method of producing the interval of lifetime, method of time scale conversion. The paper also analyzes the characteristics and the using scope of the two methods. By using the conception of service age reduction factor, the model of equipment's life process under incomplete maintenance condition is established, and also the life process simulation method applicable to this situation is invented. (authors)

  2. Patients setup verification tool for RT (PSVTs): DRR, simulation, portal and digital images

    International Nuclear Information System (INIS)

    Lee, Suk; Seong, Jin Sil; Chu, Sung Sil; Lee, Chang Geol; Suh, Chang Ok; Kwon, Soo Il

    2003-01-01

    To develop a patients' setup verification tool (PSVT) to verify the alignment of the machine and the target isocenters, and the reproducibility of patients' setup for three dimensional conformal radiotherapy (3DCRT) and intensity modulated radiotherapy (MRT). The utilization of this system is evaluated through phantom and patient case studies. We developed and clinically tested a new method for patients' setup verification, using digitally reconstructed radiography (DRR), simulation, portal and digital images. The PSVT system was networked to a Pentium PC for the transmission of the acquired images to the PC for analysis. To verify the alignment of the machine and target isocenters, orthogonal pairs of simulation images were used as verification images. Errors in the isocenter alignment were measured by comparing the verification images with DRR of CT images. Orthogonal films were taken of all the patients once a week. These verification films were compared with the DRR were used for the treatment setup. By performing this procedure every treatment, using humanoid phantom and patient cases, the errors of localization can be analyzed, with adjustments made from the translation. The reproducibility of the patients' setup was verified using portal and digital images. The PSVT system was developed to verify the alignment of the machine and the target isocenters, and the reproducibility of the patients' setup for 3DCRT and IMRT The results show that the localization errors are 0.8±0.2 mm (AP) and 1.0±0.3 mm (Lateral) in the cases relating to the brain and 1.1± 0.5 mm (AP) and 1.0±0.6 mm (Lateral) in the cases relating to the pelvis. The reproducibility of the patients' setup was verified by visualization, using real-time image acquisition, leading to the practical utilization of our software. A PSVT system was developed for the verification of the alignment between machine and the target isocenters, and the reproducibility of the patients' setup in 3DCRT and IMRT

  3. Non-analogue Monte Carlo method, application to neutron simulation; Methode de Monte Carlo non analogue, application a la simulation des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Morillon, B.

    1996-12-31

    With most of the traditional and contemporary techniques, it is still impossible to solve the transport equation if one takes into account a fully detailed geometry and if one studies precisely the interactions between particles and matters. Only the Monte Carlo method offers such a possibility. However with significant attenuation, the natural simulation remains inefficient: it becomes necessary to use biasing techniques where the solution of the adjoint transport equation is essential. The Monte Carlo code Tripoli has been using such techniques successfully for a long time with different approximate adjoint solutions: these methods require from the user to find out some parameters. If this parameters are not optimal or nearly optimal, the biases simulations may bring about small figures of merit. This paper presents a description of the most important biasing techniques of the Monte Carlo code Tripoli ; then we show how to calculate the importance function for general geometry with multigroup cases. We present a completely automatic biasing technique where the parameters of the biased simulation are deduced from the solution of the adjoint transport equation calculated by collision probabilities. In this study we shall estimate the importance function through collision probabilities method and we shall evaluate its possibilities thanks to a Monte Carlo calculation. We compare different biased simulations with the importance function calculated by collision probabilities for one-group and multigroup problems. We have run simulations with new biasing method for one-group transport problems with isotropic shocks and for multigroup problems with anisotropic shocks. The results show that for the one-group and homogeneous geometry transport problems the method is quite optimal without splitting and russian roulette technique but for the multigroup and heterogeneous X-Y geometry ones the figures of merit are higher if we add splitting and russian roulette technique.

  4. METHODS OF SIMULATION ON THE MAP OF ETHNOGEOGRAPHICAL KNOWLEDGE

    Directory of Open Access Journals (Sweden)

    A. M. Saraeva

    2017-01-01

    Full Text Available The article deals with the features of the spatial representation of the location of objects and phenomena on the Earth. One of the types of “cartographic representation” is modeling on the contour map. The advantages of the method are revealed. The application of modeling techniques that allows one to include ethnogeographic data in the content of the characteristics of the territory and reflect them on the contour map. The basis of ethnogeographic modeling is the identification and creation of elements of the material and spiritual culture of peoples by means of conventional signs. Comparison of these elements, their superimposition with respect to each other, as well as their comparison with geographic maps allow us to determine the interrelations and the dependence of the phenomenon. Modeling on contour maps is the basic method of learning in geography. On the one hand, it creates a cartographic image of the studied territory, and on the other hand it facilitates the creation of “visual supports” on the map.Modeling on contour maps, at the beginning students put the basic geographical names, which will serve as the basic knowledge. Then, by purposefully analyzing and comparing the thematic maps of the atlas or textbook, the students reflect specific ethno-geographical knowledge on contour maps. As a result, contour maps acquire “their own face”, and do not become a simple copy of maps of an atlas or textbook.Also, the features of the effect of this technique on the formation of spatial representations about the studied object have been analyzed. Thanks to the cartographic model, one can maintain a constant cognitive interest in the material studied. Modeling on the contour map will allow one to present the structure of the links between the elements of the ethnogeographical material. The basis of ethnogeographic modeling on the contour map is the identification and mapping of elements of the material and spiritual culture of

  5. Real-time tumor ablation simulation based on the dynamic mode decomposition method

    KAUST Repository

    Bourantas, George C.; Ghommem, Mehdi; Kagadis, George C.; Katsanos, Konstantinos H.; Loukopoulos, Vassilios C.; Burganos, Vasilis N.; Nikiforidis, George C.

    2014-01-01

    Purpose: The dynamic mode decomposition (DMD) method is used to provide a reliable forecasting of tumor ablation treatment simulation in real time, which is quite needed in medical practice. To achieve this, an extended Pennes bioheat model must

  6. Estimation of functional failure probability of passive systems based on subset simulation method

    International Nuclear Information System (INIS)

    Wang Dongqing; Wang Baosheng; Zhang Jianmin; Jiang Jing

    2012-01-01

    In order to solve the problem of multi-dimensional epistemic uncertainties and small functional failure probability of passive systems, an innovative reliability analysis algorithm called subset simulation based on Markov chain Monte Carlo was presented. The method is found on the idea that a small failure probability can be expressed as a product of larger conditional failure probabilities by introducing a proper choice of intermediate failure events. Markov chain Monte Carlo simulation was implemented to efficiently generate conditional samples for estimating the conditional failure probabilities. Taking the AP1000 passive residual heat removal system, for example, the uncertainties related to the model of a passive system and the numerical values of its input parameters were considered in this paper. And then the probability of functional failure was estimated with subset simulation method. The numerical results demonstrate that subset simulation method has the high computing efficiency and excellent computing accuracy compared with traditional probability analysis methods. (authors)

  7. Reliability Assessment of Active Distribution System Using Monte Carlo Simulation Method

    Directory of Open Access Journals (Sweden)

    Shaoyun Ge

    2014-01-01

    Full Text Available In this paper we have treated the reliability assessment problem of low and high DG penetration level of active distribution system using the Monte Carlo simulation method. The problem is formulated as a two-case program, the program of low penetration simulation and the program of high penetration simulation. The load shedding strategy and the simulation process were introduced in detail during each FMEA process. Results indicate that the integration of DG can improve the reliability of the system if the system was operated actively.

  8. Simulation modelling of a patient surge in an emergency department under disaster conditions

    Directory of Open Access Journals (Sweden)

    Muhammet Gul

    2015-10-01

    Full Text Available The efficiency of emergency departments (EDs in handling patient surges during disaster times using the available resources is very important. Many EDs require additional resources to overcome the bottlenecks in emergency systems. The assumption is that EDs consider the option of temporary staff dispatching, among other options, in order to respond to an increased demand or even the hiring temporarily non-hospital medical staff. Discrete event simulation (DES, a well-known simulation method and based on the idea of process modeling, is used for establishing ED operations and management related models. In this study, a DES model is developed to investigate and analyze an ED under normal conditions and an ED in a disaster scenario which takes into consideration an increased influx of disaster victims-patients. This will allow early preparedness of emergency departments in terms of physical and human resources. The studied ED is located in an earthquake zone in Istanbul. The report on Istanbul’s disaster preparedness presented by the Japan International Cooperation Agency (JICA and Istanbul Metropolitan Municipality (IMM, asserts that the district where the ED is located is estimated to have the highest injury rate. Based on real case study information, the study aims to suggest a model on pre-planning of ED resources for disasters. The results indicate that in times of a possible disaster, when the percentage of red patient arrivals exceeds 20% of total patient arrivals, the number of red area nurses and the available space for red area patients will be insufficient for the department to operate effectively. A methodological improvement presented a different distribution function that was tested for service time of the treatment areas. The conclusion is that the Weibull distribution function used in service process of injection room fits the model better than the Gamma distribution function.

  9. Analysis of time integration methods for the compressible two-fluid model for pipe flow simulations

    NARCIS (Netherlands)

    B. Sanderse (Benjamin); I. Eskerud Smith (Ivar); M.H.W. Hendrix (Maurice)

    2017-01-01

    textabstractIn this paper we analyse different time integration methods for the two-fluid model and propose the BDF2 method as the preferred choice to simulate transient compressible multiphase flow in pipelines. Compared to the prevailing Backward Euler method, the BDF2 scheme has a significantly

  10. The effect of human patient simulation on critical thinking and its predictors in prelicensure nursing students.

    Science.gov (United States)

    Shinnick, Mary Ann; Woo, Mary A

    2013-09-01

    Human patient simulation (HPS) is becoming a popular teaching method in nursing education globally and is believed to enhance both knowledge and critical thinking. While there is evidence that HPS improves knowledge, there is no objective nursing data to support HPS impact on critical thinking. Therefore, we studied knowledge and critical thinking before and after HPS in prelicensure nursing students and attempted to identify the predictors of higher critical thinking scores. Using a one-group, quasi-experimental, pre-test post-test design, 154 prelicensure nursing students (age 25.7± 6.7; gender=87.7% female) from 3 schools were studied at the same point in their curriculum using a high-fidelity simulation. Pre- and post-HPS assessments of knowledge, critical thinking, and self-efficacy were done as well as assessments for demographics and learning style. There was a mean improvement in knowledge scores of 6.5 points (Pcritical thinking scores. A logistic regression with 10 covariates revealed three variables to be predictors of higher critical thinking scores: greater "age" (P=0.01), baseline "knowledge" (P=0.04) and a low self-efficacy score ("not at all confident") in "baseline self-efficacy in managing a patient's fluid levels" (P=.05). This study reveals that gains in knowledge with HPS do not equate to changes in critical thinking. It does expose the variables of older age, higher baseline knowledge and low self-efficacy in "managing a patient's fluid levels" as being predictive of higher critical thinking ability. Further study is warranted to determine the effect of repeated or sequential simulations (dosing) and timing after the HPS experience on critical thinking gains. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. To improve training methods in an engine room simulator-based training

    OpenAIRE

    Lin, Chingshin

    2016-01-01

    The simulator based training are used widely in both industry and school education to reduce the accidents nowadays. This study aims to suggest the improved training methods to increase the effectiveness of engine room simulator training. The effectiveness of training in engine room will be performance indicators and the self-evaluation by participants. In the first phase of observation, the aim is to find out the possible shortcomings of current training methods based on train...

  12. Study of the quantitative analysis approach of maintenance by the Monte Carlo simulation method

    International Nuclear Information System (INIS)

    Shimizu, Takashi

    2007-01-01

    This study is examination of the quantitative valuation by Monte Carlo simulation method of maintenance activities of a nuclear power plant. Therefore, the concept of the quantitative valuation of maintenance that examination was advanced in the Japan Society of Maintenology and International Institute of Universality (IUU) was arranged. Basis examination for quantitative valuation of maintenance was carried out at simple feed water system, by Monte Carlo simulation method. (author)

  13. Simulations

    CERN Document Server

    Ngada, Narcisse

    2015-06-15

    The complexity and cost of building and running high-power electrical systems make the use of simulations unavoidable. The simulations available today provide great understanding about how systems really operate. This paper helps the reader to gain an insight into simulation in the field of power converters for particle accelerators. Starting with the definition and basic principles of simulation, two simulation types, as well as their leading tools, are presented: analog and numerical simulations. Some practical applications of each simulation type are also considered. The final conclusion then summarizes the main important items to keep in mind before opting for a simulation tool or before performing a simulation.

  14. Evaluation of a proposed optimization method for discrete-event simulation models

    Directory of Open Access Journals (Sweden)

    Alexandre Ferreira de Pinho

    2012-12-01

    Full Text Available Optimization methods combined with computer-based simulation have been utilized in a wide range of manufacturing applications. However, in terms of current technology, these methods exhibit low performance levels which are only able to manipulate a single decision variable at a time. Thus, the objective of this article is to evaluate a proposed optimization method for discrete-event simulation models based on genetic algorithms which exhibits more efficiency in relation to computational time when compared to software packages on the market. It should be emphasized that the variable's response quality will not be altered; that is, the proposed method will maintain the solutions' effectiveness. Thus, the study draws a comparison between the proposed method and that of a simulation instrument already available on the market and has been examined in academic literature. Conclusions are presented, confirming the proposed optimization method's efficiency.

  15. Comparison of Two Methods for Speeding Up Flash Calculations in Compositional Simulations

    DEFF Research Database (Denmark)

    Belkadi, Abdelkrim; Yan, Wei; Michelsen, Michael Locht

    2011-01-01

    Flash calculation is the most time consuming part in compositional reservoir simulations and several approaches have been proposed to speed it up. Two recent approaches proposed in the literature are the shadow region method and the Compositional Space Adaptive Tabulation (CSAT) method. The shadow...... region method reduces the computation time mainly by skipping stability analysis for a large portion of compositions in the single phase region. In the two-phase region, a highly efficient Newton-Raphson algorithm can be employed with initial estimates from the previous step. The CSAT method saves...... and the tolerance set for accepting the feed composition are the key parameters in this method since they will influence the simulation speed and the accuracy of simulation results. Inspired by CSAT, we proposed a Tieline Distance Based Approximation (TDBA) method to get approximate flash results in the twophase...

  16. INTEGRATING DATA ANALYTICS AND SIMULATION METHODS TO SUPPORT MANUFACTURING DECISION MAKING

    Science.gov (United States)

    Kibira, Deogratias; Hatim, Qais; Kumara, Soundar; Shao, Guodong

    2017-01-01

    Modern manufacturing systems are installed with smart devices such as sensors that monitor system performance and collect data to manage uncertainties in their operations. However, multiple parameters and variables affect system performance, making it impossible for a human to make informed decisions without systematic methodologies and tools. Further, the large volume and variety of streaming data collected is beyond simulation analysis alone. Simulation models are run with well-prepared data. Novel approaches, combining different methods, are needed to use this data for making guided decisions. This paper proposes a methodology whereby parameters that most affect system performance are extracted from the data using data analytics methods. These parameters are used to develop scenarios for simulation inputs; system optimizations are performed on simulation data outputs. A case study of a machine shop demonstrates the proposed methodology. This paper also reviews candidate standards for data collection, simulation, and systems interfaces. PMID:28690363

  17. A quasi-3-dimensional simulation method for a high-voltage level-shifting circuit structure

    International Nuclear Information System (INIS)

    Liu Jizhi; Chen Xingbi

    2009-01-01

    A new quasi-three-dimensional (quasi-3D) numeric simulation method for a high-voltage level-shifting circuit structure is proposed. The performances of the 3D structure are analyzed by combining some 2D device structures; the 2D devices are in two planes perpendicular to each other and to the surface of the semiconductor. In comparison with Davinci, the full 3D device simulation tool, the quasi-3D simulation method can give results for the potential and current distribution of the 3D high-voltage level-shifting circuit structure with appropriate accuracy and the total CPU time for simulation is significantly reduced. The quasi-3D simulation technique can be used in many cases with advantages such as saving computing time, making no demands on the high-end computer terminals, and being easy to operate. (semiconductor integrated circuits)

  18. A quasi-3-dimensional simulation method for a high-voltage level-shifting circuit structure

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jizhi; Chen Xingbi, E-mail: jzhliu@uestc.edu.c [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2009-12-15

    A new quasi-three-dimensional (quasi-3D) numeric simulation method for a high-voltage level-shifting circuit structure is proposed. The performances of the 3D structure are analyzed by combining some 2D device structures; the 2D devices are in two planes perpendicular to each other and to the surface of the semiconductor. In comparison with Davinci, the full 3D device simulation tool, the quasi-3D simulation method can give results for the potential and current distribution of the 3D high-voltage level-shifting circuit structure with appropriate accuracy and the total CPU time for simulation is significantly reduced. The quasi-3D simulation technique can be used in many cases with advantages such as saving computing time, making no demands on the high-end computer terminals, and being easy to operate. (semiconductor integrated circuits)

  19. System dynamic simulation: A new method in social impact assessment (SIA)

    Energy Technology Data Exchange (ETDEWEB)

    Karami, Shobeir, E-mail: shobeirkarami@gmail.com [Agricultural Extension and Education, Shiraz University (Iran, Islamic Republic of); Karami, Ezatollah, E-mail: ekarami@shirazu.ac.ir [Agricultural Extension and Education, Shiraz University (Iran, Islamic Republic of); Buys, Laurie, E-mail: l.buys@qut.edu.au [Creative Industries Faculty, School of Design, Queensland University of Technology (Australia); Drogemuller, Robin, E-mail: robin.drogemuller@qut.edu.au [Creative Industries Faculty, School of Design, Queensland University of Technology (Australia)

    2017-01-15

    Many complex social questions are difficult to address adequately with conventional methods and techniques, due to the complicated dynamics, and hard to quantify social processes. Despite these difficulties researchers and practitioners have attempted to use conventional methods not only in evaluative modes but also in predictive modes to inform decision making. The effectiveness of SIAs would be increased if they were used to support the project design processes. This requires deliberate use of lessons from retrospective assessments to inform predictive assessments. Social simulations may be a useful tool for developing a predictive SIA method. There have been limited attempts to develop computer simulations that allow social impacts to be explored and understood before implementing development projects. In light of this argument, this paper aims to introduce system dynamic (SD) simulation as a new predictive SIA method in large development projects. We propose the potential value of the SD approach to simulate social impacts of development projects. We use data from the SIA of Gareh-Bygone floodwater spreading project to illustrate the potential of SD simulation in SIA. It was concluded that in comparison to traditional SIA methods SD simulation can integrate quantitative and qualitative inputs from different sources and methods and provides a more effective and dynamic assessment of social impacts for development projects. We recommend future research to investigate the full potential of SD in SIA in comparing different situations and scenarios.

  20. Study on simulation methods of atrium building cooling load in hot and humid regions

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Yiqun; Li, Yuming; Huang, Zhizhong [Institute of Building Performance and Technology, Sino-German College of Applied Sciences, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Wu, Gang [Weldtech Technology (Shanghai) Co. Ltd. (China)

    2010-10-15

    In recent years, highly glazed atria are popular because of their architectural aesthetics and advantage of introducing daylight into inside. However, cooling load estimation of such atrium buildings is difficult due to complex thermal phenomena that occur in the atrium space. The study aims to find out a simplified method of estimating cooling loads through simulations for various types of atria in hot and humid regions. Atrium buildings are divided into different types. For every type of atrium buildings, both CFD and energy models are developed. A standard method versus the simplified one is proposed to simulate cooling load of atria in EnergyPlus based on different room air temperature patterns as a result from CFD simulation. It incorporates CFD results as input into non-dimensional height room air models in EnergyPlus, and the simulation results are defined as a baseline model in order to compare with the results from the simplified method for every category of atrium buildings. In order to further validate the simplified method an actual atrium office building is tested on site in a typical summer day and measured results are compared with simulation results using the simplified methods. Finally, appropriate methods of simulating different types of atrium buildings are proposed. (author)

  1. System dynamic simulation: A new method in social impact assessment (SIA)

    International Nuclear Information System (INIS)

    Karami, Shobeir; Karami, Ezatollah; Buys, Laurie; Drogemuller, Robin

    2017-01-01

    Many complex social questions are difficult to address adequately with conventional methods and techniques, due to the complicated dynamics, and hard to quantify social processes. Despite these difficulties researchers and practitioners have attempted to use conventional methods not only in evaluative modes but also in predictive modes to inform decision making. The effectiveness of SIAs would be increased if they were used to support the project design processes. This requires deliberate use of lessons from retrospective assessments to inform predictive assessments. Social simulations may be a useful tool for developing a predictive SIA method. There have been limited attempts to develop computer simulations that allow social impacts to be explored and understood before implementing development projects. In light of this argument, this paper aims to introduce system dynamic (SD) simulation as a new predictive SIA method in large development projects. We propose the potential value of the SD approach to simulate social impacts of development projects. We use data from the SIA of Gareh-Bygone floodwater spreading project to illustrate the potential of SD simulation in SIA. It was concluded that in comparison to traditional SIA methods SD simulation can integrate quantitative and qualitative inputs from different sources and methods and provides a more effective and dynamic assessment of social impacts for development projects. We recommend future research to investigate the full potential of SD in SIA in comparing different situations and scenarios.

  2. Methods to score vertebral deformities in patients with rheumatoid arthritis

    NARCIS (Netherlands)

    Lems, W. F.; Jahangier, Z. N.; Raymakers, J. A.; Jacobs, J. W.; Bijlsma, J. W.

    1997-01-01

    The objective was to compare four different scoring methods for vertebral deformities: the semiquantitative Kleerekoper score and three quantitative scores (according to Minne, Melton and Raymakers) in patients with rheumatoid arthritis (RA). Lateral radiographs of the thoracic and lumbar vertebral

  3. Concentration gradient driven molecular dynamics: a new method for simulations of membrane permeation and separation.

    Science.gov (United States)

    Ozcan, Aydin; Perego, Claudio; Salvalaglio, Matteo; Parrinello, Michele; Yazaydin, Ozgur

    2017-05-01

    In this study, we introduce a new non-equilibrium molecular dynamics simulation method to perform simulations of concentration driven membrane permeation processes. The methodology is based on the application of a non-conservative bias force controlling the concentration of species at the inlet and outlet of a membrane. We demonstrate our method for pure methane, ethane and ethylene permeation and for ethane/ethylene separation through a flexible ZIF-8 membrane. Results show that a stationary concentration gradient is maintained across the membrane, realistically simulating an out-of-equilibrium diffusive process, and the computed permeabilities and selectivity are in good agreement with experimental results.

  4. A method for data handling numerical results in parallel OpenFOAM simulations

    International Nuclear Information System (INIS)

    nd Vasile Pârvan Ave., 300223, TM Timişoara, Romania, alin.anton@cs.upt.ro (Romania))" data-affiliation=" (Faculty of Automatic Control and Computing, Politehnica University of Timişoara, 2nd Vasile Pârvan Ave., 300223, TM Timişoara, Romania, alin.anton@cs.upt.ro (Romania))" >Anton, Alin; th Mihai Viteazu Ave., 300221, TM Timişoara (Romania))" data-affiliation=" (Center for Advanced Research in Engineering Science, Romanian Academy – Timişoara Branch, 24th Mihai Viteazu Ave., 300221, TM Timişoara (Romania))" >Muntean, Sebastian

    2015-01-01

    Parallel computational fluid dynamics simulations produce vast amount of numerical result data. This paper introduces a method for reducing the size of the data by replaying the interprocessor traffic. The results are recovered only in certain regions of interest configured by the user. A known test case is used for several mesh partitioning scenarios using the OpenFOAM toolkit ® [1]. The space savings obtained with classic algorithms remain constant for more than 60 Gb of floating point data. Our method is most efficient on large simulation meshes and is much better suited for compressing large scale simulation results than the regular algorithms

  5. A method for data handling numerical results in parallel OpenFOAM simulations

    Energy Technology Data Exchange (ETDEWEB)

    Anton, Alin [Faculty of Automatic Control and Computing, Politehnica University of Timişoara, 2" n" d Vasile Pârvan Ave., 300223, TM Timişoara, Romania, alin.anton@cs.upt.ro (Romania); Muntean, Sebastian [Center for Advanced Research in Engineering Science, Romanian Academy – Timişoara Branch, 24" t" h Mihai Viteazu Ave., 300221, TM Timişoara (Romania)

    2015-12-31

    Parallel computational fluid dynamics simulations produce vast amount of numerical result data. This paper introduces a method for reducing the size of the data by replaying the interprocessor traffic. The results are recovered only in certain regions of interest configured by the user. A known test case is used for several mesh partitioning scenarios using the OpenFOAM toolkit{sup ®}[1]. The space savings obtained with classic algorithms remain constant for more than 60 Gb of floating point data. Our method is most efficient on large simulation meshes and is much better suited for compressing large scale simulation results than the regular algorithms.

  6. Simulation methods supporting homologation of Electronic Stability Control in vehicle variants

    Science.gov (United States)

    Lutz, Albert; Schick, Bernhard; Holzmann, Henning; Kochem, Michael; Meyer-Tuve, Harald; Lange, Olav; Mao, Yiqin; Tosolin, Guido

    2017-10-01

    Vehicle simulation has a long tradition in the automotive industry as a powerful supplement to physical vehicle testing. In the field of Electronic Stability Control (ESC) system, the simulation process has been well established to support the ESC development and application by suppliers and Original Equipment Manufacturers (OEMs). The latest regulation of the United Nations Economic Commission for Europe UN/ECE-R 13 allows also for simulation-based homologation. This extends the usage of simulation from ESC development to homologation. This paper gives an overview of simulation methods, as well as processes and tools used for the homologation of ESC in vehicle variants. The paper first describes the generic homologation process according to the European Regulation (UN/ECE-R 13H, UN/ECE-R 13/11) and U.S. Federal Motor Vehicle Safety Standard (FMVSS 126). Subsequently the ESC system is explained as well as the generic application and release process at the supplier and OEM side. Coming up with the simulation methods, the ESC development and application process needs to be adapted for the virtual vehicles. The simulation environment, consisting of vehicle model, ESC model and simulation platform, is explained in detail with some exemplary use-cases. In the final section, examples of simulation-based ESC homologation in vehicle variants are shown for passenger cars, light trucks, heavy trucks and trailers. This paper is targeted to give a state-of-the-art account of the simulation methods supporting the homologation of ESC systems in vehicle variants. However, the described approach and the lessons learned can be used as reference in future for an extended usage of simulation-supported releases of the ESC system up to the development and release of driver assistance systems.

  7. COMPARISON OF METHODS FOR SIMULATING TSUNAMI RUN-UP THROUGH COASTAL FORESTS

    Directory of Open Access Journals (Sweden)

    Benazir

    2017-09-01

    Full Text Available The research is aimed at reviewing two numerical methods for modeling the effect of coastal forest on tsunami run-up and to propose an alternative approach. Two methods for modeling the effect of coastal forest namely the Constant Roughness Model (CRM and Equivalent Roughness Model (ERM simulate the effect of the forest by using an artificial Manning roughness coefficient. An alternative approach that simulates each of the trees as a vertical square column is introduced. Simulations were carried out with variations of forest density and layout pattern of the trees. The numerical model was validated using an existing data series of tsunami run-up without forest protection. The study indicated that the alternative method is in good agreement with ERM method for low forest density. At higher density and when the trees were planted in a zigzag pattern, the ERM produced significantly higher run-up. For a zigzag pattern and at 50% forest densities which represents a water tight wall, both the ERM and CRM methods produced relatively high run-up which should not happen theoretically. The alternative method, on the other hand, reflected the entire tsunami. In reality, housing complex can be considered and simulated as forest with various size and layout of obstacles where the alternative approach is applicable. The alternative method is more accurate than the existing methods for simulating a coastal forest for tsunami mitigation but consumes considerably more computational time.

  8. Hybrid statistics-simulations based method for atom-counting from ADF STEM images.

    Science.gov (United States)

    De Wael, Annelies; De Backer, Annick; Jones, Lewys; Nellist, Peter D; Van Aert, Sandra

    2017-06-01

    A hybrid statistics-simulations based method for atom-counting from annular dark field scanning transmission electron microscopy (ADF STEM) images of monotype crystalline nanostructures is presented. Different atom-counting methods already exist for model-like systems. However, the increasing relevance of radiation damage in the study of nanostructures demands a method that allows atom-counting from low dose images with a low signal-to-noise ratio. Therefore, the hybrid method directly includes prior knowledge from image simulations into the existing statistics-based method for atom-counting, and accounts in this manner for possible discrepancies between actual and simulated experimental conditions. It is shown by means of simulations and experiments that this hybrid method outperforms the statistics-based method, especially for low electron doses and small nanoparticles. The analysis of a simulated low dose image of a small nanoparticle suggests that this method allows for far more reliable quantitative analysis of beam-sensitive materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Reliability Verification of DBE Environment Simulation Test Facility by using Statistics Method

    International Nuclear Information System (INIS)

    Jang, Kyung Nam; Kim, Jong Soeg; Jeong, Sun Chul; Kyung Heum

    2011-01-01

    In the nuclear power plant, all the safety-related equipment including cables under the harsh environment should perform the equipment qualification (EQ) according to the IEEE std 323. There are three types of qualification methods including type testing, operating experience and analysis. In order to environmentally qualify the safety-related equipment using type testing method, not analysis or operation experience method, the representative sample of equipment, including interfaces, should be subjected to a series of tests. Among these tests, Design Basis Events (DBE) environment simulating test is the most important test. DBE simulation test is performed in DBE simulation test chamber according to the postulated DBE conditions including specified high-energy line break (HELB), loss of coolant accident (LOCA), main steam line break (MSLB) and etc, after thermal and radiation aging. Because most DBE conditions have 100% humidity condition, in order to trace temperature and pressure of DBE condition, high temperature steam should be used. During DBE simulation test, if high temperature steam under high pressure inject to the DBE test chamber, the temperature and pressure in test chamber rapidly increase over the target temperature. Therefore, the temperature and pressure in test chamber continue fluctuating during the DBE simulation test to meet target temperature and pressure. We should ensure fairness and accuracy of test result by confirming the performance of DBE environment simulation test facility. In this paper, in order to verify reliability of DBE environment simulation test facility, statistics method is used

  10. Identifying deterministic signals in simulated gravitational wave data: algorithmic complexity and the surrogate data method

    International Nuclear Information System (INIS)

    Zhao Yi; Small, Michael; Coward, David; Howell, Eric; Zhao Chunnong; Ju Li; Blair, David

    2006-01-01

    We describe the application of complexity estimation and the surrogate data method to identify deterministic dynamics in simulated gravitational wave (GW) data contaminated with white and coloured noises. The surrogate method uses algorithmic complexity as a discriminating statistic to decide if noisy data contain a statistically significant level of deterministic dynamics (the GW signal). The results illustrate that the complexity method is sensitive to a small amplitude simulated GW background (SNR down to 0.08 for white noise and 0.05 for coloured noise) and is also more robust than commonly used linear methods (autocorrelation or Fourier analysis)

  11. The Application of Simulation Method in Isothermal Elastic Natural Gas Pipeline

    Science.gov (United States)

    Xing, Chunlei; Guan, Shiming; Zhao, Yue; Cao, Jinggang; Chu, Yanji

    2018-02-01

    This Elastic pipeline mathematic model is of crucial importance in natural gas pipeline simulation because of its compliance with the practical industrial cases. The numerical model of elastic pipeline will bring non-linear complexity to the discretized equations. Hence the Newton-Raphson method cannot achieve fast convergence in this kind of problems. Therefore A new Newton Based method with Powell-Wolfe Condition to simulate the Isothermal elastic pipeline flow is presented. The results obtained by the new method aregiven based on the defined boundary conditions. It is shown that the method converges in all cases and reduces significant computational cost.

  12. MODFLOW equipped with a new method for the accurate simulation of axisymmetric flow

    Science.gov (United States)

    Samani, N.; Kompani-Zare, M.; Barry, D. A.

    2004-01-01

    Axisymmetric flow to a well is an important topic of groundwater hydraulics, the simulation of which depends on accurate computation of head gradients. Groundwater numerical models with conventional rectilinear grid geometry such as MODFLOW (in contrast to analytical models) generally have not been used to simulate aquifer test results at a pumping well because they are not designed or expected to closely simulate the head gradient near the well. A scaling method is proposed based on mapping the governing flow equation from cylindrical to Cartesian coordinates, and vice versa. A set of relationships and scales is derived to implement the conversion. The proposed scaling method is then embedded in MODFLOW 2000. To verify the accuracy of the method steady and unsteady flows in confined and unconfined aquifers with fully or partially penetrating pumping wells are simulated and compared with the corresponding analytical solutions. In all cases a high degree of accuracy is achieved.

  13. A Multiscale Simulation Method and Its Application to Determine the Mechanical Behavior of Heterogeneous Geomaterials

    Directory of Open Access Journals (Sweden)

    Shengwei Li

    2017-01-01

    Full Text Available To study the micro/mesomechanical behaviors of heterogeneous geomaterials, a multiscale simulation method that combines molecular simulation at the microscale, a mesoscale analysis of polished slices, and finite element numerical simulation is proposed. By processing the mesostructure images obtained from analyzing the polished slices of heterogeneous geomaterials and mapping them onto finite element meshes, a numerical model that more accurately reflects the mesostructures of heterogeneous geomaterials was established by combining the results with the microscale mechanical properties of geomaterials obtained from the molecular simulation. This model was then used to analyze the mechanical behaviors of heterogeneous materials. Because kernstone is a typical heterogeneous material that comprises many types of mineral crystals, it was used for the micro/mesoscale mechanical behavior analysis in this paper using the proposed method. The results suggest that the proposed method can be used to accurately and effectively study the mechanical behaviors of heterogeneous geomaterials at the micro/mesoscales.

  14. Scalable Methods for Eulerian-Lagrangian Simulation Applied to Compressible Multiphase Flows

    Science.gov (United States)

    Zwick, David; Hackl, Jason; Balachandar, S.

    2017-11-01

    Multiphase flows can be found in countless areas of physics and engineering. Many of these flows can be classified as dispersed two-phase flows, meaning that there are solid particles dispersed in a continuous fluid phase. A common technique for simulating such flow is the Eulerian-Lagrangian method. While useful, this method can suffer from scaling issues on larger problem sizes that are typical of many realistic geometries. Here we present scalable techniques for Eulerian-Lagrangian simulations and apply it to the simulation of a particle bed subjected to expansion waves in a shock tube. The results show that the methods presented here are viable for simulation of larger problems on modern supercomputers. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1315138. This work was supported in part by the U.S. Department of Energy under Contract No. DE-NA0002378.

  15. Development and Validation of Simulated Virtual Patients to Impart Early Clinical Exposure in Endocrine Physiology

    Science.gov (United States)

    Gupta, Akriti; Singh, Satendra; Khaliq, Farah; Dhaliwal, Upreet; Madhu, S. V.

    2018-01-01

    In the country presently, preclinical medical students are not routinely exposed to real patients. Thus, when they start clinical postings, they are found to have poor clinical reasoning skills. Simulated virtual patients (SVPs) can improve clinical skills without endangering real patients. This pilot study describes the development of two SVPs in…

  16. Knowledge-Driven Design of Virtual Patient Simulations

    Science.gov (United States)

    Vergara, Victor; Caudell, Thomas; Goldsmith, Timothy; Panaiotis; Alverson, Dale

    2009-01-01

    Virtual worlds provide unique opportunities for instructors to promote, study, and evaluate student learning and comprehension. In this article, Victor Vergara, Thomas Caudell, Timothy Goldsmith, Panaiotis, and Dale Alverson explore the advantages of using virtual reality environments to create simulations for medical students. Virtual simulations…

  17. Resolved-particle simulation by the Physalis method: Enhancements and new capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Sierakowski, Adam J., E-mail: sierakowski@jhu.edu [Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Prosperetti, Andrea [Department of Mechanical Engineering, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Faculty of Science and Technology and J.M. Burgers Centre for Fluid Dynamics, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2016-03-15

    We present enhancements and new capabilities of the Physalis method for simulating disperse multiphase flows using particle-resolved simulation. The current work enhances the previous method by incorporating a new type of pressure-Poisson solver that couples with a new Physalis particle pressure boundary condition scheme and a new particle interior treatment to significantly improve overall numerical efficiency. Further, we implement a more efficient method of calculating the Physalis scalar products and incorporate short-range particle interaction models. We provide validation and benchmarking for the Physalis method against experiments of a sedimenting particle and of normal wall collisions. We conclude with an illustrative simulation of 2048 particles sedimenting in a duct. In the appendix, we present a complete and self-consistent description of the analytical development and numerical methods.

  18. Method for simulating predictive control of building systems operation in the early stages of building design

    DEFF Research Database (Denmark)

    Petersen, Steffen; Svendsen, Svend

    2011-01-01

    A method for simulating predictive control of building systems operation in the early stages of building design is presented. The method uses building simulation based on weather forecasts to predict whether there is a future heating or cooling requirement. This information enables the thermal...... control systems of the building to respond proactively to keep the operational temperature within the thermal comfort range with the minimum use of energy. The method is implemented in an existing building simulation tool designed to inform decisions in the early stages of building design through...... parametric analysis. This enables building designers to predict the performance of the method and include it as a part of the solution space. The method furthermore facilitates the task of configuring appropriate building systems control schemes in the tool, and it eliminates time consuming manual...

  19. Maximum Simulated Likelihood and Expectation-Maximization Methods to Estimate Random Coefficients Logit with Panel Data

    DEFF Research Database (Denmark)

    Cherchi, Elisabetta; Guevara, Cristian

    2012-01-01

    with cross-sectional or with panel data, and (d) EM systematically attained more efficient estimators than the MSL method. The results imply that if the purpose of the estimation is only to determine the ratios of the model parameters (e.g., the value of time), the EM method should be preferred. For all......The random coefficients logit model allows a more realistic representation of agents' behavior. However, the estimation of that model may involve simulation, which may become impractical with many random coefficients because of the curse of dimensionality. In this paper, the traditional maximum...... simulated likelihood (MSL) method is compared with the alternative expectation- maximization (EM) method, which does not require simulation. Previous literature had shown that for cross-sectional data, MSL outperforms the EM method in the ability to recover the true parameters and estimation time...

  20. The effect of high fidelity simulated learning methods on physiotherapy pre-registration education: a systematic review protocol.

    Science.gov (United States)

    Roberts, Fiona; Cooper, Kay

    2017-11-01

    The objective of this review is to identify if high fidelity simulated learning methods are effective in enhancing clinical/practical skills compared to usual, low fidelity simulated learning methods in pre-registration physiotherapy education.

  1. A new algorithm for the simulation of the Boltzmann equation using the direct simulation monte-carlo method

    International Nuclear Information System (INIS)

    Ganjaei, A. A.; Nourazar, S. S.

    2009-01-01

    A new algorithm, the modified direct simulation Monte-Carlo (MDSMC) method, for the simulation of Couette- Taylor gas flow problem is developed. The Taylor series expansion is used to obtain the modified equation of the first order time discretization of the collision equation and the new algorithm, MDSMC, is implemented to simulate the collision equation in the Boltzmann equation. In the new algorithm (MDSMC) there exists a new extra term which takes in to account the effect of the second order collision. This new extra term has the effect of enhancing the appearance of the first Taylor instabilities of vortices streamlines. In the new algorithm (MDSMC) there also exists a second order term in time step in the probabilistic coefficients which has the effect of simulation with higher accuracy than the previous DSMC algorithm. The appearance of the first Taylor instabilities of vortices streamlines using the MDSMC algorithm at different ratios of ω/ν (experimental data of Taylor) occurred at less time-step than using the DSMC algorithm. The results of the torque developed on the stationary cylinder using the MDSMC algorithm show better agreement in comparison with the experimental data of Kuhlthau than the results of the torque developed on the stationary cylinder using the DSMC algorithm

  2. Use of simulated patients to develop communication skills in nursing education: An integrative review.

    Science.gov (United States)

    MacLean, Sharon; Kelly, Michelle; Geddes, Fiona; Della, Phillip

    2017-01-01

    Registered nurses are expected to communicate effectively with patients. To improve on this skill education programmes in both hospital and tertiary settings are increasingly turning to simulation modalities when training undergraduate and registered nurses. The roles simulated patients (SPs) assume can vary according to training purposes and approach. The first aim is to analyse how SPs are used in nursing education to develop communication skills. The second aim is to evaluate the evidence that is available to support the efficacy of using SPs for training nurses in communication skills and finally to review the SP recruitment and training procedure. An Integrative review. A search was conducted on CINAHL, Psych-info, PubMed, Google Scholar, Scopus, Ovid, Medline, and ProQuest databases. Keywords and inclusion/exclusion criteria were determined and applied to the search strategy. The integrative review included Nineteen studies from 2006-2016. Critical Appraisal Skills Program (CASP) method of evaluation was utilised. Emergent themes were extracted with similar and divergent perspectives. Analysis identified seven clinical contexts for communication skills training (CST) and two SP roles from the eighteen studies. SPs were either directly involved in the teaching of communication (active role) or used in the evaluation of the effectiveness of a communication skills program (passive role). A majority of studies utilised faculty-designed measurement instruments. The evidence presented in the 19 articles indicates that the use of SPs to teach nurse-patient communication skills targets more challenging clinical interactions. Engaging SPs in both CST program facilitation and course evaluation provides nurse educators with a strong foundation to develop further pedagogical and research capacity. Expanding the utilisation of SPs to augment nurses' communication skills and ability to engage with patients in a broader range of clinical contexts with increased

  3. Petascale molecular dynamics simulation using the fast multipole method on K computer

    KAUST Repository

    Ohno, Yousuke; Yokota, Rio; Koyama, Hiroshi; Morimoto, Gentaro; Hasegawa, Aki; Masumoto, Gen; Okimoto, Noriaki; Hirano, Yoshinori; Ibeid, Huda; Narumi, Tetsu; Taiji, Makoto

    2014-01-01

    In this paper, we report all-atom simulations of molecular crowding - a result from the full node simulation on the "K computer", which is a 10-PFLOPS supercomputer in Japan. The capability of this machine enables us to perform simulation of crowded cellular environments, which are more realistic compared to conventional MD simulations where proteins are simulated in isolation. Living cells are "crowded" because macromolecules comprise ∼30% of their molecular weight. Recently, the effects of crowded cellular environments on protein stability have been revealed through in-cell NMR spectroscopy. To measure the performance of the "K computer", we performed all-atom classical molecular dynamics simulations of two systems: target proteins in a solvent, and target proteins in an environment of molecular crowders that mimic the conditions of a living cell. Using the full system, we achieved 4.4 PFLOPS during a 520 million-atom simulation with cutoff of 28 Å. Furthermore, we discuss the performance and scaling of fast multipole methods for molecular dynamics simulations on the "K computer", as well as comparisons with Ewald summation methods. © 2014 Elsevier B.V. All rights reserved.

  4. Petascale molecular dynamics simulation using the fast multipole method on K computer

    KAUST Repository

    Ohno, Yousuke

    2014-10-01

    In this paper, we report all-atom simulations of molecular crowding - a result from the full node simulation on the "K computer", which is a 10-PFLOPS supercomputer in Japan. The capability of this machine enables us to perform simulation of crowded cellular environments, which are more realistic compared to conventional MD simulations where proteins are simulated in isolation. Living cells are "crowded" because macromolecules comprise ∼30% of their molecular weight. Recently, the effects of crowded cellular environments on protein stability have been revealed through in-cell NMR spectroscopy. To measure the performance of the "K computer", we performed all-atom classical molecular dynamics simulations of two systems: target proteins in a solvent, and target proteins in an environment of molecular crowders that mimic the conditions of a living cell. Using the full system, we achieved 4.4 PFLOPS during a 520 million-atom simulation with cutoff of 28 Å. Furthermore, we discuss the performance and scaling of fast multipole methods for molecular dynamics simulations on the "K computer", as well as comparisons with Ewald summation methods. © 2014 Elsevier B.V. All rights reserved.

  5. Quasi-monte carlo simulation and variance reduction techniques substantially reduce computational requirements of patient-level simulation models: An application to a discrete event simulation model

    NARCIS (Netherlands)

    Treur, M.; Postma, M.

    2014-01-01

    Objectives: Patient-level simulation models provide increased flexibility to overcome the limitations of cohort-based approaches in health-economic analysis. However, computational requirements of reaching convergence is a notorious barrier. The objective was to assess the impact of using

  6. Comparison of ALE finite element method and adaptive smoothed finite element method for the numerical simulation of friction stir welding

    NARCIS (Netherlands)

    van der Stelt, A.A.; Bor, Teunis Cornelis; Geijselaers, Hubertus J.M.; Quak, W.; Akkerman, Remko; Huetink, Han; Menary, G

    2011-01-01

    In this paper, the material flow around the pin during friction stir welding (FSW) is simulated using a 2D plane strain model. A pin rotates without translation in a disc with elasto-viscoplastic material properties and the outer boundary of the disc is clamped. Two numerical methods are used to

  7. Methods to improve patient recruitment and retention in stroke trials

    DEFF Research Database (Denmark)

    Berge, Eivind; Stapf, Christian; Al-Shahi Salman, Rustam

    2016-01-01

    Background: The success of randomized-controlled stroke trials is dependent on the recruitment and retention of a sufficient number of patients, but fewer than half of all trials meet their target number of patients. Methods: We performed a search and review of the literature, and conducted...... a survey and workshop among 56 European stroke trialists, to identify barriers, suggest methods to improve recruitment and retention, and make a priority list of interventions that merit further evaluation. Results: The survey and workshop identified a number of barriers to patient recruitment...... and retention, from patients’ incapacity to consent, to handicaps that prevent patients from participation in trial-specific follow-up. Methods to improve recruitment and retention may include simple interventions with individual participants, funding of research networks, and reimbursement of new treatments...

  8. Interprofessional simulation to improve patient participation in transitional care.

    Science.gov (United States)

    Dyrstad, Dagrunn Nåden; Storm, Marianne

    2017-06-01

    Educating and training healthcare professionals is known to improve the quality of transitional care for older adults. Arranging interprofessional meetings for healthcare professionals might be useful to improve patient participation skills in transitional care. To describe the learning activities used in The Meeting Point programme, focusing on patient participation in transitional care, and assess whether they increase healthcare professionals' awareness of and competencies relating to patient participation in the transitional care of older patients. Data were collected as part of an educational intervention programme, The Meeting Point, including three seminars on 'Patient participation in the transitional care of older patients' and four follow-up meetings. Participants were nurses, care assistants, doctors, physiotherapists, patient coordinators and administrative personnel from hospital, nursing homes and home-based care services. The Meeting Point was organised around four pillars: introduction, teaching session, group work activity and plenary discussion. Qualitative data included log reports, summaries of meetings, notes from group work activities, and reports from participants and from follow-up meetings. Feedback from participants shows that they were satisfied with meeting healthcare professionals from other units of care. A film scenario was perceived relevant for group work activity and useful in focusing participants' attention to patient participation. Follow-up meetings show that some nursing home wards, the emergency department and one medical ward at the hospital continued with ongoing work to improve quality of care. Efforts included implementation of an observational waiting room with comfortable chairs, planning for discharge in hospital admission, a daily patient flow registration system and motivational interviewing during admission to nursing home. The description of the learning activities used at The Meeting Point seminars shows that they

  9. Fluid distribution network and steam generators and method for nuclear power plant training simulator

    International Nuclear Information System (INIS)

    Alliston, W.H.; Johnson, S.J.; Mutafelija, B.A.

    1975-01-01

    A description is given of a training simulator for the real-time dynamic operation of a nuclear power plant which utilizes apparatus that includes control consoles having manual and automatic devices corresponding to simulated plant components and indicating devices for monitoring physical values in the simulated plant. A digital computer configuration is connected to the control consoles to calculate the dynamic real-time simulated operation of the plant in accordance with the simulated plant components to provide output data including data for operating the control console indicating devices. In the method and system for simulating a fluid distribution network of the power plant, such as that which includes, for example, a main steam system which distributes steam from steam generators to high pressure turbine steam reheaters, steam dump valves, and feedwater heaters, the simultaneous solution of linearized non-linear algebraic equations is used to calculate all the flows throughout the simulated system. A plurality of parallel connected steam generators that supply steam to the system are simulated individually, and include the simulation of shrink-swell characteristics

  10. Basic study on a lower-energy defibrillation method using computer simulation and cultured myocardial cell models.

    Science.gov (United States)

    Yaguchi, A; Nagase, K; Ishikawa, M; Iwasaka, T; Odagaki, M; Hosaka, H

    2006-01-01

    Computer simulation and myocardial cell models were used to evaluate a low-energy defibrillation technique. A generated spiral wave, considered to be a mechanism of fibrillation, and fibrillation were investigated using two myocardial sheet models: a two-dimensional computer simulation model and a two-dimensional experimental model. A new defibrillation technique that has few side effects, which are induced by the current passing into the patient's body, on cardiac muscle is desired. The purpose of the present study is to conduct a basic investigation into an efficient defibrillation method. In order to evaluate the defibrillation method, the propagation of excitation in the myocardial sheet is measured during the normal state and during fibrillation, respectively. The advantages of the low-energy defibrillation technique are then discussed based on the stimulation timing.

  11. Research on neutron noise analysis stochastic simulation method for α calculation

    International Nuclear Information System (INIS)

    Zhong Bin; Shen Huayun; She Ruogu; Zhu Shengdong; Xiao Gang

    2014-01-01

    The prompt decay constant α has significant application on the physical design and safety analysis in nuclear facilities. To overcome the difficulty of a value calculation with Monte-Carlo method, and improve the precision, a new method based on the neutron noise analysis technology was presented. This method employs the stochastic simulation and the theory of neutron noise analysis technology. Firstly, the evolution of stochastic neutron was simulated by discrete-events Monte-Carlo method based on the theory of generalized Semi-Markov process, then the neutron noise in detectors was solved from neutron signal. Secondly, the neutron noise analysis methods such as Rossia method, Feynman-α method, zero-probability method, and cross-correlation method were used to calculate a value. All of the parameters used in neutron noise analysis method were calculated based on auto-adaptive arithmetic. The a value from these methods accords with each other, the largest relative deviation is 7.9%, which proves the feasibility of a calculation method based on neutron noise analysis stochastic simulation. (authors)

  12. Methods for teaching effective patient communication techniques to radiography students.

    Science.gov (United States)

    Makely, S

    1990-07-01

    Teaching students to communicate effectively with patients has always been part of the radiography curriculum in the USA. However, developing these skills has become even more important in recent times due to several factors. Patients who have been well versed in what to expect from the examination being conducted are in a better position to co-operate with the radiographer. This increases the chances of producing optimal results from an examination at the first attempt, thus reducing radiation exposure, patient discomfort and the overall cost of conducting the procedure. Also, increased competition among health care providers has resulted in more emphasis being placed on patient, or customer, satisfaction. Radiographers are in the 'front line' of patient care. Patients often have more interaction with radiographers than with physicians or other medical specialists. Radiographers who practise effective communication techniques with their patients can alleviate anxiety and make an important contribution to the overall satisfaction of the patient with respect to the quality of service and care they receive. This article describes instructional methods being used in the USA to help develop effective patient communication techniques, and reports the findings of a study among radiography educators as to which of these methods are thought to be most successful.

  13. Optimal learning in a virtual patient simulation of cranial nerve palsies: The interaction between social learning context and student aptitude

    Science.gov (United States)

    JOHNSON, TERESA R.; LYONS, REBECCA; CHUAH, JOON HAO; KOPPER, REGIS; LOK, BENJAMIN C.; CENDAN, JUAN C.

    2013-01-01

    Background Simulation in medical education provides students with opportunities to practice interviews, examinations, and diagnosis formulation related to complex conditions without risks to patients. Aim To examine differences between individual and team participation on learning outcomes and student perspectives through use of virtual patients (VPs) for teaching cranial nerve (CN) evaluation. Methods Fifty-seven medical students were randomly assigned to complete simulation exercises either as individuals or as members of three-person teams. Students interviewed, examined, and diagnosed VPs with possible CN damage in the Neurological Exam Rehearsal Virtual Environment (NERVE). Knowledge of CN abnormalities was assessed pre- and post-simulation. Student perspectives of system usability were evaluated post-simulation. Results An aptitude-treatment interaction (ATI) effect was detected; at pre-test scores ≤50%, students in teams scored higher (83%) at post-test than did students as individuals (62%, p = 0.02). Post-simulation, students in teams reported greater confidence in their ability to diagnose CN abnormalities than did students as individuals (p = 0.02; mean rating = 4.0/5.0 and 3.4/5.0, respectively). Conclusion The ATI effect allows us to begin defining best practices for the integration of VP simulators into the medical curriculum. We are persuaded to implement future NERVE exercises with small teams of medical students. PMID:22938679

  14. Advanced scientific computational methods and their applications of nuclear technologies. (1) Overview of scientific computational methods, introduction of continuum simulation methods and their applications (1)

    International Nuclear Information System (INIS)

    Oka, Yoshiaki; Okuda, Hiroshi

    2006-01-01

    Scientific computational methods have advanced remarkably with the progress of nuclear development. They have played the role of weft connecting each realm of nuclear engineering and then an introductory course of advanced scientific computational methods and their applications to nuclear technologies were prepared in serial form. This is the first issue showing their overview and introduction of continuum simulation methods. Finite element method as their applications is also reviewed. (T. Tanaka)

  15. Using qualitative methods to understand factors contributing to patient satisfaction among dermatology patients: a systematic review.

    Science.gov (United States)

    Gibbons, Caitlin; Singh, Sanminder; Gibbons, Brittany; Clark, Caitlin; Torres, Josefina; Cheng, Michelle Y; Wang, Elizabeth A; Armstrong, April W

    2018-05-01

    In this systematic review, we aimed to synthesize data that identify factors contributing to patient satisfaction in dermatology care using qualitative methods. We performed a comprehensive search of the literature using the PubMed database for articles published between January 1, 2000 and February 9, 2015. The initial search yielded 186 articles, of which 13 were included after applying inclusion and exclusion criteria. The systematic review of 13 articles included a total of 330 patients. Using in-field observations and semistructured interviews, studies found that qualitative methods and analysis increased the provider's sensitivity to patient needs and enhanced patient care. Analyses using qualitative methods found increased patient satisfaction in their healthcare provider is associated with (1) confidence in the provider's diagnosis, (2) perception of patient-centered, individualized recommendations and (3) quality of patient education and provider explanation during a visit. Patient satisfaction is measured using either quantitative or qualitative methods. Quantitative methods result in standardized data that often does not capture the nuances of patient experience. In contrast, qualitative methodology is integral to gathering patient perspectives on patient care and satisfaction and should be included in future research models.

  16. Test of a Cardiology Patient Simulator with Students in Fourth-Year Electives.

    Science.gov (United States)

    Ewy, Gordon A.; And Others

    1987-01-01

    Students at five medical schools participated in an evaluation of a cardiology patient simulator (CPS), a life-size mannequin capable of simulating a wide variety of cardiovascular conditions. The CPS enhances learning both the knowledge and the skills necessary to perform a bedside cardiovascular evaluation. (Author/MLW)

  17. Use of clinical simulations for patient education: targeting an untapped audience.

    Science.gov (United States)

    Siwe, Karin; Berterö, Carina; Pugh, Carla; Wijma, Barbro

    2009-01-01

    In most cases, the health professional has been the target for simulation based learning curricula. We have developed a simulation based curriculum for patient education. In our curriculum lay-women learn how to perform the clinical female pelvic examination using a manikin-based trainer. Learner assessments show that prior negative expectations turned into positive expectations regarding future pelvic examinations.

  18. A regularized vortex-particle mesh method for large eddy simulation

    DEFF Research Database (Denmark)

    Spietz, Henrik Juul; Walther, Jens Honore; Hejlesen, Mads Mølholm

    We present recent developments of the remeshed vortex particle-mesh method for simulating incompressible fluid flow. The presented method relies on a parallel higher-order FFT based solver for the Poisson equation. Arbitrary high order is achieved through regularization of singular Green’s function...... solutions to the Poisson equation and recently we have derived novel high order solutions for a mixture of open and periodic domains. With this approach the simulated variables may formally be viewed as the approximate solution to the filtered Navier Stokes equations, hence we use the method for Large Eddy...

  19. Three-Dimensional Phase Field Simulations of Hysteresis and Butterfly Loops by the Finite Volume Method

    International Nuclear Information System (INIS)

    Xi Li-Ying; Chen Huan-Ming; Zheng Fu; Gao Hua; Tong Yang; Ma Zhi

    2015-01-01

    Three-dimensional simulations of ferroelectric hysteresis and butterfly loops are carried out based on solving the time dependent Ginzburg–Landau equations using a finite volume method. The influence of externally mechanical loadings with a tensile strain and a compressive strain on the hysteresis and butterfly loops is studied numerically. Different from the traditional finite element and finite difference methods, the finite volume method is applicable to simulate the ferroelectric phase transitions and properties of ferroelectric materials even for more realistic and physical problems. (paper)

  20. Analysis on the influence of supply method on a workstation with the help of dynamic simulation

    Directory of Open Access Journals (Sweden)

    Gavriluță Alin

    2017-01-01

    Full Text Available Considering the need of flexibility in any manufacturing process, the choice of the supply method of an assembly workstation can be a decision with instead influence on its performances. Using dynamic simulation, this article wants to compare the effect on a workstation cycle time of three different supply methods: supply on stock, supply in “Strike Zone” and synchronous supply. This study is part of an extended work that has the aim of compering by 3D layout design and dynamic simulation, different supply methods on an assembly line performances.

  1. Parallel shooting methods for finding steady state solutions to engine simulation models

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2007-01-01

    Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set...

  2. A Lagrangian finite element method for the simulation of flow of non-newtonian liquids

    DEFF Research Database (Denmark)

    Hassager, Ole; Bisgaard, C

    1983-01-01

    A Lagrangian method for the simulation of flow of non-Newtonian liquids is implemented. The fluid mechanical equations are formulated in the form of a variational principle, and a discretization is performed by finite elements. The method is applied to the slow of a contravariant convected Maxwell...

  3. Application of a perturbation method for realistic dynamic simulation of industrial robots

    NARCIS (Netherlands)

    Waiboer, R.R.; Aarts, Ronald G.K.M.; Jonker, Jan B.

    2005-01-01

    This paper presents the application of a perturbation method for the closed-loop dynamic simulation of a rigid-link manipulator with joint friction. In this method the perturbed motion of the manipulator is modelled as a first-order perturbation of the nominal manipulator motion. A non-linear finite

  4. Implementation of Simulation Based-Concept Attainment Method to Increase Interest Learning of Engineering Mechanics Topic

    Science.gov (United States)

    Sultan, A. Z.; Hamzah, N.; Rusdi, M.

    2018-01-01

    The implementation of concept attainment method based on simulation was used to increase student’s interest in the subjects Engineering of Mechanics in second semester of academic year 2016/2017 in Manufacturing Engineering Program, Department of Mechanical PNUP. The result of the implementation of this learning method shows that there is an increase in the students’ learning interest towards the lecture material which is summarized in the form of interactive simulation CDs and teaching materials in the form of printed books and electronic books. From the implementation of achievement method of this simulation based concept, it is noted that the increase of student participation in the presentation and discussion as well as the deposit of individual assignment of significant student. With the implementation of this method of learning the average student participation reached 89%, which before the application of this learning method only reaches an average of 76%. And also with previous learning method, for exam achievement of A-grade under 5% and D-grade above 8%. After the implementation of the new learning method (simulation based-concept attainment method) the achievement of Agrade has reached more than 30% and D-grade below 1%.

  5. A Simulation Method for High-Cycle Fatigue-Driven Delamination using a Cohesive Zone Model

    DEFF Research Database (Denmark)

    Bak, Brian Lau Verndal; Turon, A.; Lindgaard, Esben

    2016-01-01

    on parameter fitting of any kind. The method has been implemented as a zero-thickness eight-node interface element for Abaqus and as a spring element for a simple finite element model in MATLAB. The method has been validated in simulations of mode I, mode II, and mixed-mode crack loading for both self...

  6. Validation of the intrinsic spatial efficiency method for non cylindrical homogeneous sources using MC simulation

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Ramírez, Pablo, E-mail: rapeitor@ug.uchile.cl; Ruiz, Andrés [Departamento de Física, Facultad de Ciencias, Universidad de Chile (Chile)

    2016-07-07

    The Monte Carlo simulation of the gamma spectroscopy systems is a common practice in these days. The most popular softwares to do this are MCNP and Geant4 codes. The intrinsic spatial efficiency method is a general and absolute method to determine the absolute efficiency of a spectroscopy system for any extended sources, but this was only demonstrated experimentally for cylindrical sources. Due to the difficulty that the preparation of sources with any shape represents, the simplest way to do this is by the simulation of the spectroscopy system and the source. In this work we present the validation of the intrinsic spatial efficiency method for sources with different geometries and for photons with an energy of 661.65 keV. In the simulation the matrix effects (the auto-attenuation effect) are not considered, therefore these results are only preliminaries. The MC simulation is carried out using the FLUKA code and the absolute efficiency of the detector is determined using two methods: the statistical count of Full Energy Peak (FEP) area (traditional method) and the intrinsic spatial efficiency method. The obtained results show total agreement between the absolute efficiencies determined by the traditional method and the intrinsic spatial efficiency method. The relative bias is lesser than 1% in all cases.

  7. Simulation of Steady Laser Hardening by an Arbitrary Lagrangian Eulerian Method

    NARCIS (Netherlands)

    Geijselaers, Hubertus J.M.; Huetink, Han

    2004-01-01

    One of the most practical methods for simulation of steady state thermal processing is the Arbitrary Lagrangian- Eulerian method. Each calculation step is split into two phases. In the first phase, the Lagrangian phase, the element mesh remains attached to the material. The evolution of the state

  8. Interactive knowledge discovery from marketing questionnarie using simulated breeding and inductive learning methods

    Energy Technology Data Exchange (ETDEWEB)

    Terano, Takao [Univ. of Tsukuba, Tokyo (Japan); Ishino, Yoko [Univ. of Tokyo (Japan)

    1996-12-31

    This paper describes a novel method to acquire efficient decision rules from questionnaire data using both simulated breeding and inductive learning techniques. The basic ideas of the method are that simulated breeding is used to get the effective features from the questionnaire data and that inductive learning is used to acquire simple decision rules from the data. The simulated breeding is one of the Genetic Algorithm (GA) based techniques to subjectively or interactively evaluate the qualities of offspring generated by genetic operations. In this paper, we show a basic interactive version of the method and two variations: the one with semi-automated GA phases and the one with the relatively evaluation phase via the Analytic Hierarchy Process (AHP). The proposed method has been qualitatively and quantitatively validated by a case study on consumer product questionnaire data.

  9. A Multi-Projector Calibration Method for Virtual Reality Simulators with Analytically Defined Screens

    Directory of Open Access Journals (Sweden)

    Cristina Portalés

    2017-06-01

    Full Text Available The geometric calibration of projectors is a demanding task, particularly for the industry of virtual reality simulators. Different methods have been developed during the last decades to retrieve the intrinsic and extrinsic parameters of projectors, most of them being based on planar homographies and some requiring an extended calibration process. The aim of our research work is to design a fast and user-friendly method to provide multi-projector calibration on analytically defined screens, where a sample is shown for a virtual reality Formula 1 simulator that has a cylindrical screen. The proposed method results from the combination of surveying, photogrammetry and image processing approaches, and has been designed by considering the spatial restrictions of virtual reality simulators. The method has been validated from a mathematical point of view, and the complete system—which is currently installed in a shopping mall in Spain—has been tested by different users.

  10. Numerical simulation of electromagnetic wave propagation using time domain meshless method

    International Nuclear Information System (INIS)

    Ikuno, Soichiro; Fujita, Yoshihisa; Itoh, Taku; Nakata, Susumu; Nakamura, Hiroaki; Kamitani, Atsushi

    2012-01-01

    The electromagnetic wave propagation in various shaped wave guide is simulated by using meshless time domain method (MTDM). Generally, Finite Differential Time Domain (FDTD) method is applied for electromagnetic wave propagation simulation. However, the numerical domain should be divided into rectangle meshes if FDTD method is applied for the simulation. On the other hand, the node disposition of MTDM can easily describe the structure of arbitrary shaped wave guide. This is the large advantage of the meshless time domain method. The results of computations show that the damping rate is stably calculated in case with R < 0.03, where R denotes a support radius of the weight function for the shape function. And the results indicate that the support radius R of the weight functions should be selected small, and monomials must be used for calculating the shape functions. (author)

  11. Investigation of Compton scattering correction methods in cardiac SPECT by Monte Carlo simulations

    International Nuclear Information System (INIS)

    Silva, A.M. Marques da; Furlan, A.M.; Robilotta, C.C.

    2001-01-01

    The goal of this work was the use of Monte Carlo simulations to investigate the effects of two scattering correction methods: dual energy window (DEW) and dual photopeak window (DPW), in quantitative cardiac SPECT reconstruction. MCAT torso-cardiac phantom, with 99m Tc and non-uniform attenuation map was simulated. Two different photopeak windows were evaluated in DEW method: 15% and 20%. Two 10% wide subwindows centered symmetrically within the photopeak were used in DPW method. Iterative ML-EM reconstruction with modified projector-backprojector for attenuation correction was applied. Results indicated that the choice of the scattering and photopeak windows determines the correction accuracy. For the 15% window, fitted scatter fraction gives better results than k = 0.5. For the 20% window, DPW is the best method, but it requires parameters estimation using Monte Carlo simulations. (author)

  12. A New Method to Simulate Free Surface Flows for Viscoelastic Fluid

    Directory of Open Access Journals (Sweden)

    Yu Cao

    2015-01-01

    Full Text Available Free surface flows arise in a variety of engineering applications. To predict the dynamic characteristics of such problems, specific numerical methods are required to accurately capture the shape of free surface. This paper proposed a new method which combined the Arbitrary Lagrangian-Eulerian (ALE technique with the Finite Volume Method (FVM to simulate the time-dependent viscoelastic free surface flows. Based on an open source CFD toolbox called OpenFOAM, we designed an ALE-FVM free surface simulation platform. In the meantime, the die-swell flow had been investigated with our proposed platform to make a further analysis of free surface phenomenon. The results validated the correctness and effectiveness of the proposed method for free surface simulation in both Newtonian fluid and viscoelastic fluid.

  13. Multiscale Lattice Boltzmann method for flow simulations in highly heterogenous porous media

    KAUST Repository

    Li, Jun

    2013-01-01

    A lattice Boltzmann method (LBM) for flow simulations in highly heterogeneous porous media at both pore and Darcy scales is proposed in the paper. In the pore scale simulations, flow of two phases (e.g., oil and gas) or two immiscible fluids (e.g., water and oil) are modeled using cohesive or repulsive forces, respectively. The relative permeability can be computed using pore-scale simulations and seamlessly applied for intermediate and Darcy-scale simulations. A multiscale LBM that can reduce the computational complexity of existing LBM and transfer the information between different scales is implemented. The results of coarse-grid, reduced-order, simulations agree very well with the averaged results obtained using fine grid.

  14. analysis of large electromagnetic pulse simulators using the electric field integral equation method in time domain

    International Nuclear Information System (INIS)

    Jamali, J.; Aghajafari, R.; Moini, R.; Sadeghi, H.

    2002-01-01

    A time-domain approach is presented to calculate electromagnetic fields inside a large Electromagnetic Pulse (EMP) simulator. This type of EMP simulator is used for studying the effect of electromagnetic pulses on electrical apparatus in various structures such as vehicles, a reoplanes, etc. The simulator consists of three planar transmission lines. To solve the problem, we first model the metallic structure of the simulator as a grid of conducting wires. The numerical solution of the governing electric field integral equation is then obtained using the method of moments in time domain. To demonstrate the accuracy of the model, we consider a typical EMP simulator. The comparison of our results with those obtained experimentally in the literature validates the model introduced in this paper

  15. Training simulator for nuclear power plant reactor control model and method

    International Nuclear Information System (INIS)

    Czerbuejewski, F.R.

    1975-01-01

    A description is given of a method and system for the real-time dynamic simulation of a nuclear power plant for training purposes, wherein a control console has a plurality of manual and automatic remote control devices for operating simulated control rods and has indicating devices for monitoring the physical operation of a simulated reactor. Digital computer means are connected to the control console to calculate data values for operating the monitoring devices in accordance with the control devices. The simulation of the reactor control rod mechanism is disclosed whereby the digital computer means operates the rod position monitoring devices in a real-time that is a fraction of the computer time steps and simulates the quick response of a control rod remote control lever together with the delayed response upon a change of direction

  16. Communication skills of nurses during interactions with simulated cancer patients

    NARCIS (Netherlands)

    Kruijver, IPM; Kerkstra, A; Bensing, JM; van de Wiel, H.B.M.

    Aim. In this paper the balance of affective and instrumental communication employed by nurses during the admission interview with recently diagnosed cancer patients was investigated. Rationale. The balance of affective and instrumental communication employed by nurses appears to be important,

  17. Communication skills of nurses during interactions with simulated cancer patients.

    NARCIS (Netherlands)

    Kruijver, I.P.M.; Kerkstra, A.; Bensing, J.M.; Wiel, H.B.M. van der

    2001-01-01

    In this paper the balance of affective and intrumental communication employed by nurses during the admission interview with recently diagnosed cancer patients was investigated. Rationale: The balance of affective and instrumental communication employed by nurses appears to be important, especially

  18. Methods for simulation-based analysis of fluid-structure interaction.

    Energy Technology Data Exchange (ETDEWEB)

    Barone, Matthew Franklin; Payne, Jeffrey L.

    2005-10-01

    Methods for analysis of fluid-structure interaction using high fidelity simulations are critically reviewed. First, a literature review of modern numerical techniques for simulation of aeroelastic phenomena is presented. The review focuses on methods contained within the arbitrary Lagrangian-Eulerian (ALE) framework for coupling computational fluid dynamics codes to computational structural mechanics codes. The review treats mesh movement algorithms, the role of the geometric conservation law, time advancement schemes, wetted surface interface strategies, and some representative applications. The complexity and computational expense of coupled Navier-Stokes/structural dynamics simulations points to the need for reduced order modeling to facilitate parametric analysis. The proper orthogonal decomposition (POD)/Galerkin projection approach for building a reduced order model (ROM) is presented, along with ideas for extension of the methodology to allow construction of ROMs based on data generated from ALE simulations.

  19. Lattice Boltzmann method used to simulate particle motion in a conduit

    Directory of Open Access Journals (Sweden)

    Dolanský Jindřich

    2017-06-01

    Full Text Available A three-dimensional numerical simulation of particle motion in a pipe with a rough bed is presented. The simulation based on the Lattice Boltzmann Method (LBM employs the hybrid diffuse bounce-back approach to model moving boundaries. The bed of the pipe is formed by stationary spherical particles of the same size as the moving particles. Particle movements are induced by gravitational and hydrodynamic forces. To evaluate the hydrodynamic forces, the Momentum Exchange Algorithm is used. The LBM unified computational frame makes it possible to simulate both the particle motion and the fluid flow and to study mutual interactions of the carrier liquid flow and particles and the particle–bed and particle–particle collisions. The trajectories of simulated and experimental particles are compared. The Particle Tracking method is used to track particle motion. The correctness of the applied approach is assessed.

  20. An optimization method of relativistic backward wave oscillator using particle simulation and genetic algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zaigao; Wang, Jianguo [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China); Northwest Institute of Nuclear Technology, P.O. Box 69-12, Xi' an, Shaanxi 710024 (China); Wang, Yue; Qiao, Hailiang; Zhang, Dianhui [Northwest Institute of Nuclear Technology, P.O. Box 69-12, Xi' an, Shaanxi 710024 (China); Guo, Weijie [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2013-11-15

    Optimal design method of high-power microwave source using particle simulation and parallel genetic algorithms is presented in this paper. The output power, simulated by the fully electromagnetic particle simulation code UNIPIC, of the high-power microwave device is given as the fitness function, and the float-encoding genetic algorithms are used to optimize the high-power microwave devices. Using this method, we encode the heights of non-uniform slow wave structure in the relativistic backward wave oscillators (RBWO), and optimize the parameters on massively parallel processors. Simulation results demonstrate that we can obtain the optimal parameters of non-uniform slow wave structure in the RBWO, and the output microwave power enhances 52.6% after the device is optimized.

  1. Modeling and Simulation of DC Power Electronics Systems Using Harmonic State Space (HSS) Method

    DEFF Research Database (Denmark)

    Kwon, Jun Bum; Wang, Xiongfei; Bak, Claus Leth

    2015-01-01

    based on the state-space averaging and generalized averaging, these also have limitations to show the same results as with the non-linear time domain simulations. This paper presents a modeling and simulation method for a large dc power electronic system by using Harmonic State Space (HSS) modeling......For the efficiency and simplicity of electric systems, the dc based power electronics systems are widely used in variety applications such as electric vehicles, ships, aircrafts and also in homes. In these systems, there could be a number of dynamic interactions between loads and other dc-dc....... Through this method, the required computation time and CPU memory for large dc power electronics systems can be reduced. Besides, the achieved results show the same results as with the non-linear time domain simulation, but with the faster simulation time which is beneficial in a large network....

  2. A modular method to handle multiple time-dependent quantities in Monte Carlo simulations

    International Nuclear Information System (INIS)

    Shin, J; Faddegon, B A; Perl, J; Schümann, J; Paganetti, H

    2012-01-01

    A general method for handling time-dependent quantities in Monte Carlo simulations was developed to make such simulations more accessible to the medical community for a wide range of applications in radiotherapy, including fluence and dose calculation. To describe time-dependent changes in the most general way, we developed a grammar of functions that we call ‘Time Features’. When a simulation quantity, such as the position of a geometrical object, an angle, a magnetic field, a current, etc, takes its value from a Time Feature, that quantity varies over time. The operation of time-dependent simulation was separated into distinct parts: the Sequence samples time values either sequentially at equal increments or randomly from a uniform distribution (allowing quantities to vary continuously in time), and then each time-dependent quantity is calculated according to its Time Feature. Due to this modular structure, time-dependent simulations, even in the presence of multiple time-dependent quantities, can be efficiently performed in a single simulation with any given time resolution. This approach has been implemented in TOPAS (TOol for PArticle Simulation), designed to make Monte Carlo simulations with Geant4 more accessible to both clinical and research physicists. To demonstrate the method, three clinical situations were simulated: a variable water column used to verify constancy of the Bragg peak of the Crocker Lab eye treatment facility of the University of California, the double-scattering treatment mode of the passive beam scattering system at Massachusetts General Hospital (MGH), where a spinning range modulator wheel accompanied by beam current modulation produces a spread-out Bragg peak, and the scanning mode at MGH, where time-dependent pulse shape, energy distribution and magnetic fields control Bragg peak positions. Results confirm the clinical applicability of the method. (paper)

  3. Fetal doses to pregnant patients from CT with tube current modulation calculated using Monte Carlo simulations and realistic phantoms

    International Nuclear Information System (INIS)

    Gu, J.; George Xu, X.; Caracappa, P. F.; Liu, B.

    2013-01-01

    To investigate the radiation dose to the fetus using retrospective tube current modulation (TCM) data selected from archived clinical records. This paper describes the calculation of fetal doses using retrospective TCM data and Monte Carlo (MC) simulations. Three TCM schemes were adopted for use with three pregnant patient phantoms. MC simulations were used to model CT scanners, TCM schemes and pregnant patients. Comparisons between organ doses from TCM schemes and those from non-TCM schemes show that these three TCM schemes reduced fetal doses by 14, 18 and 25 %, respectively. These organ doses were also compared with those from ImPACT calculation. It is found that the difference between the calculated fetal dose and the ImPACT reported dose is as high as 46 %. This work demonstrates methods to study organ doses from various TCM protocols and potential ways to improve the accuracy of CT dose calculation for pregnant patients. (authors)

  4. Comparison of a Material Point Method and a Galerkin Meshfree Method for the Simulation of Cohesive-Frictional Materials

    Directory of Open Access Journals (Sweden)

    Ilaria Iaconeta

    2017-09-01

    Full Text Available The simulation of large deformation problems, involving complex history-dependent constitutive laws, is of paramount importance in several engineering fields. Particular attention has to be paid to the choice of a suitable numerical technique such that reliable results can be obtained. In this paper, a Material Point Method (MPM and a Galerkin Meshfree Method (GMM are presented and verified against classical benchmarks in solid mechanics. The aim is to demonstrate the good behavior of the methods in the simulation of cohesive-frictional materials, both in static and dynamic regimes and in problems dealing with large deformations. The vast majority of MPM techniques in the literatrue are based on some sort of explicit time integration. The techniques proposed in the current work, on the contrary, are based on implicit approaches, which can also be easily adapted to the simulation of static cases. The two methods are presented so as to highlight the similarities to rather than the differences from “standard” Updated Lagrangian (UL approaches commonly employed by the Finite Elements (FE community. Although both methods are able to give a good prediction, it is observed that, under very large deformation of the medium, GMM lacks robustness due to its meshfree natrue, which makes the definition of the meshless shape functions more difficult and expensive than in MPM. On the other hand, the mesh-based MPM is demonstrated to be more robust and reliable for extremely large deformation cases.

  5. Simulation of 3D parachute fluid–structure interaction based on nonlinear finite element method and preconditioning finite volume method

    Directory of Open Access Journals (Sweden)

    Fan Yuxin

    2014-12-01

    Full Text Available A fluid–structure interaction method combining a nonlinear finite element algorithm with a preconditioning finite volume method is proposed in this paper to simulate parachute transient dynamics. This method uses a three-dimensional membrane–cable fabric model to represent a parachute system at a highly folded configuration. The large shape change during parachute inflation is computed by the nonlinear Newton–Raphson iteration and the linear system equation is solved by the generalized minimal residual (GMRES method. A membrane wrinkling algorithm is also utilized to evaluate the special uniaxial tension state of membrane elements on the parachute canopy. In order to avoid large time expenses during structural nonlinear iteration, the implicit Hilber–Hughes–Taylor (HHT time integration method is employed. For the fluid dynamic simulations, the Roe and HLLC (Harten–Lax–van Leer contact scheme has been modified and extended to compute flow problems at all speeds. The lower–upper symmetric Gauss–Seidel (LU-SGS approximate factorization is applied to accelerate the numerical convergence speed. Finally, the test model of a highly folded C-9 parachute is simulated at a prescribed speed and the results show similar characteristics compared with experimental results and previous literature.

  6. Ambulatory orthopaedic surgery patients' emotions when using different patient education methods.

    Science.gov (United States)

    Heikkinen, Katja; Salanterä, Sanna; Leppänen, Tiina; Vahlberg, Tero; Leino-Kilpi, Helena

    2012-07-01

    A randomised controlled trial was used to evaluate elective ambulatory orthopaedic surgery patients' emotions during internet-based patient education or face-to-face education with a nurse. The internet-based patient education was designed for this study and patients used websites individually based on their needs. Patients in the control group participated individually in face-to-face patient education with a nurse in the ambulatory surgery unit. The theoretical basis for both types of education was the same. Ambulatory orthopaedic surgery patients scored their emotions rather low at intervals throughout the whole surgical process, though their scores also changed during the surgical process. Emotion scores did not decrease after patient education. No differences in patients' emotions were found to result from either of the two different patient education methods.

  7. Investigation of vessel visibility of iterative reconstruction method in coronary computed tomography angiography using simulated vessel phantom

    International Nuclear Information System (INIS)

    Inoue, Takeshi; Uto, Fumiaki; Ichikawa, Katsuhiro; Hara, Takanori; Urikura, Atsushi; Hoshino, Takashi; Miura, Youhei; Terakawa, Syouichi

    2012-01-01

    Iterative reconstruction methods can reduce the noise of computed tomography (CT) images, which are expected to contribute to the reduction of patient dose CT examinations. The purpose of this study was to investigate impact of an iterative reconstruction method (iDose 4 , Philips Healthcare) on vessel visibility in coronary CT angiography (CTA) by using phantom studies. A simulated phantom was scanned by a CT system (iCT, Philips Healthcare), and the axial images were reconstructed by filtered back projection (FBP) and given a level of 1 to 7 (L1-L7) of the iterative reconstruction (IR). The vessel visibility was evaluated by a quantitative analysis using profiles across a 1.5-mm diameter simulated vessel as well as visual evaluation for multi planar reformation (MPR) images and volume rendering (VR) images in terms of the normalized-rank method with analysis of variance. The peak CT value of the profiles decreased with IR level and full width at half maximum of the profile also decreased with the IR level. For normalized-rank method, there was no statistical difference between FBP and L1 (20% dose reduction) for both MPR and VR images. The IR levels higher than L1 sacrificed the spatial resolution for the 1.5-mm simulated vessel, and their visual vessel visibilities were significantly inferior to that of the FBP. (author)

  8. Solar panel thermal cycling testing by solar simulation and infrared radiation methods

    Science.gov (United States)

    Nuss, H. E.

    1980-01-01

    For the solar panels of the European Space Agency (ESA) satellites OTS/MAROTS and ECS/MARECS the thermal cycling tests were performed by using solar simulation methods. The performance data of two different solar simulators used and the thermal test results are described. The solar simulation thermal cycling tests for the ECS/MARECS solar panels were carried out with the aid of a rotatable multipanel test rig by which simultaneous testing of three solar panels was possible. As an alternative thermal test method, the capability of an infrared radiation method was studied and infrared simulation tests for the ultralight panel and the INTELSAT 5 solar panels were performed. The setup and the characteristics of the infrared radiation unit using a quartz lamp array of approx. 15 sq and LN2-cooled shutter and the thermal test results are presented. The irradiation uniformity, the solar panel temperature distribution, temperature changing rates for both test methods are compared. Results indicate the infrared simulation is an effective solar panel thermal testing method.

  9. Two methods to simulate intrapulpal pressure: effects upon bonding performance of self-etch adhesives.

    Science.gov (United States)

    Feitosa, V P; Gotti, V B; Grohmann, C V; Abuná, G; Correr-Sobrinho, L; Sinhoreti, M A C; Correr, A B

    2014-09-01

    To evaluate the effects of two methods to simulate physiological pulpal pressure on the dentine bonding performance of two all-in-one adhesives and a two-step self-etch silorane-based adhesive by means of microtensile bond strength (μTBS) and nanoleakage surveys. The self-etch adhesives [G-Bond Plus (GB), Adper Easy Bond (EB) and silorane adhesive (SIL)] were applied to flat deep dentine surfaces from extracted human molars. The restorations were constructed using resin composites Filtek Silorane or Filtek Z350 (3M ESPE). After 24 h using the two methods of simulated pulpal pressure or no pulpal pressure (control groups), the bonded teeth were cut into specimens and submitted to μTBS and silver uptake examination. Results were analysed with two-way anova and Tukey's test (P adhesives. No difference between control and pulpal pressure groups was found for SIL and GB. EB led significant drop (P = 0.002) in bond strength under pulpal pressure. Silver impregnation was increased after both methods of simulated pulpal pressure for all adhesives, and it was similar between the simulated pulpal pressure methods. The innovative method to simulate pulpal pressure behaved similarly to the classic one and could be used as an alternative. The HEMA-free one-step and the two-step self-etch adhesives had acceptable resistance against pulpal pressure, unlike the HEMA-rich adhesive. © 2013 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  10. BRAND program complex for neutron-physical experiment simulation by the Monte-Carlo method

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.

    1984-01-01

    Possibilities of the BRAND program complex for neutron and γ-radiation transport simulation by the Monte-Carlo method are described in short. The complex includes the following modules: geometric module, source module, detector module, modules of simulation of a vector of particle motion direction after interaction and a free path. The complex is written in the FORTRAN langauage and realized by the BESM-6 computer

  11. Determinant method and quantum simulations of many-body effects in a single impurity Anderson model

    International Nuclear Information System (INIS)

    Gubernatis, J.E.; Olson, T.; Scalapino, D.J.; Sugar, R.L.

    1985-01-01

    A short description is presented of a quantum Monte Carlo technique, often referred to as the determinant method, that has proved useful for simulating many-body effects in systems of interacting fermions at finite temperatures. Preliminary results using this technique on a single impurity Anderson model are reported. Examples of such many-body effects as local moment formation, Kondo behavior, and mixed valence phenomena found in the simulations are shown. 10 refs., 3 figs

  12. cophesim: a comprehensive phenotype simulator for testing novel association methods [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Ilya Y. Zhbannikov

    2017-08-01

    Full Text Available Simulation is important in evaluating novel methods when input data is not easily obtainable or specific assumptions are needed. We present cophesim, a software to add the phenotype to generated genotype data prepared with a genetic simulator. The output of cophesim can be used as a direct input for different genome wide association study tools. cophesim is available from https://bitbucket.org/izhbannikov/cophesim.

  13. A general method for closed-loop inverse simulation of helicopter maneuver flight

    OpenAIRE

    Wei WU

    2017-01-01

    Maneuverability is a key factor to determine whether a helicopter could finish certain flight missions successfully or not. Inverse simulation is commonly used to calculate the pilot controls of a helicopter to complete a certain kind of maneuver flight and to assess its maneuverability. A general method for inverse simulation of maneuver flight for helicopters with the flight control system online is developed in this paper. A general mathematical describing function is established to provid...

  14. Application of the finite volume method in the simulation of saturated flows of binary mixtures

    International Nuclear Information System (INIS)

    Murad, M.A.; Gama, R.M.S. da; Sampaio, R.

    1989-12-01

    This work presents the simulation of saturated flows of an incompressible Newtonian fluid through a rigid, homogeneous and isotropic porous medium. The employed mathematical model is derived from the Continuum Theory of Mixtures and generalizes the classical one which is based on Darcy's Law form of the momentum equation. In this approach fluid and porous matrix are regarded as continuous constituents of a binary mixture. The finite volume method is employed in the simulation. (author) [pt

  15. Numerical simulation of subwoofer array congurations using the Finite Element Method

    Directory of Open Access Journals (Sweden)

    Xavier Banyuls-Juan

    2017-08-01

    Full Text Available Teaching in the Master of Acoustic Engineering includes contents that require the modeling of acoustic systems of two types: simple systems through analytical theory and complex models using simulation techniques. In the present work, we describe an example of complex acoustic sources modeling using the finite element method: subwoofer sound radiation in different configurations. Numerical simulations in the frequency domain can calculate the radiation pattern of systems that do not have a simple analytical solution.

  16. Development of NDT simulator with method of mapping for detection of pipe wall thinning using EMAT

    International Nuclear Information System (INIS)

    Yamaguchi, Hiroshi; Kojima, Fumio; Kosaka, Daigo

    2009-01-01

    This paper is concerned with a simulator related to nondestructive test using Electromagnetic Acoustic Transducer (EMAT). The simulator developed here can be applied to pipe wall thinning of stainless steel used in nuclear power plants. First, mathematical models for the inspection are given by a transient eddy current equation and by a time dependent elastic wave equation in two dimensions. Secondly, shape of pipe wall thinning is modeled by B-spline function and is applied to the mathematical models using method of mapping. Finally, the validity of the proposed simulator is shown through numerical experiment. (author)

  17. The method research of the simulator training and examination of the nuclear electricity staff

    International Nuclear Information System (INIS)

    Huang Fangzhi; Zhang Yuanfang

    1994-01-01

    The simulator training and examination of nuclear power plant operator are of an important guarantee for the nuclear power plant operation safety. The authors introduce various training courses which have been held in the Nuclear Power Plant Simulation Training Center of Tsinghua University since 1988, and analyze the different requirements and features for different classes such as operator candidate training course, operator retraining course and nuclear and electricity staff course. The lesson arrangement, examination method and mark standard are presented, which is carried out in the Nuclear Power Plant Simulation Training Center of Tsinghua University

  18. Faster Simulation Methods for the Non-Stationary Random Vibrations of Non-Linear MDOF Systems

    DEFF Research Database (Denmark)

    Askar, A.; Köylüoglu, H. U.; Nielsen, Søren R. K.

    subject to nonstationary Gaussian white noise excitation, as an alternative to conventional direct simulation methods. These alternative simulation procedures rely on an assumption of local Gaussianity during each time step. This assumption is tantamount to various linearizations of the equations....... Such a treatment offers higher rates of convergence, faster speed and higher accuracy. These procedures are compared to the direct Monte Carlo simulation procedure, which uses a fourth order Runge-Kutta scheme with the white noise process approximated by a broad band Ruiz-Penzien broken line process...

  19. Faster Simulation Methods for the Nonstationary Random Vibrations of Non-linear MDOF Systems

    DEFF Research Database (Denmark)

    Askar, A.; Köylüo, U.; Nielsen, Søren R.K.

    1996-01-01

    subject to nonstationary Gaussian white noise excitation, as an alternative to conventional direct simulation methods. These alternative simulation procedures rely on an assumption of local Gaussianity during each time step. This assumption is tantamount to various linearizations of the equations....... Such a treatment offers higher rates of convergence, faster speed and higher accuracy. These procedures are compared to the direct Monte Carlo simulation procedure, which uses a fourth order Runge-Kutta scheme with the white noise process approximated by a broad band Ruiz-Penzien broken line process...

  20. Comparison of multiple-criteria decision-making methods - results of simulation study

    Directory of Open Access Journals (Sweden)

    Michał Adamczak

    2016-12-01

    Full Text Available Background: Today, both researchers and practitioners have many methods for supporting the decision-making process. Due to the conditions in which supply chains function, the most interesting are multi-criteria methods. The use of sophisticated methods for supporting decisions requires the parameterization and execution of calculations that are often complex. So is it efficient to use sophisticated methods? Methods: The authors of the publication compared two popular multi-criteria decision-making methods: the  Weighted Sum Model (WSM and the Analytic Hierarchy Process (AHP. A simulation study reflects these two decision-making methods. Input data for this study was a set of criteria weights and the value of each in terms of each criterion. Results: The iGrafx Process for Six Sigma simulation software recreated how both multiple-criteria decision-making methods (WSM and AHP function. The result of the simulation was a numerical value defining the preference of each of the alternatives according to the WSM and AHP methods. The alternative producing a result of higher numerical value  was considered preferred, according to the selected method. In the analysis of the results, the relationship between the values of the parameters and the difference in the results presented by both methods was investigated. Statistical methods, including hypothesis testing, were used for this purpose. Conclusions: The simulation study findings prove that the results obtained with the use of two multiple-criteria decision-making methods are very similar. Differences occurred more frequently in lower-value parameters from the "value of each alternative" group and higher-value parameters from the "weight of criteria" group.