Multimodal Simulation Research Articles

Inferring thermal ion temperature and residual kinetic energy from nuclear measurements in inertial confinement fusion implosions

In inertial confinement fusion implosion experiments, the presence of residual anisotropic fluid motion within the stagnating hot spot leads to significant variations in ion-temperature measurements using neutron time-of-flight detectors along different lines of sight. The minimum ion-temperature measurement is typically used as representative of the thermal temperature. In the presence of isotropic flows, however, even the minimum Deuterium–Tritium (DT) neutron-inferred ion temperature can be well above the plasma thermal temperature. Using both Deuterium–Deuterium (DD) and DT neutron-inferred ion-temperature measurements, we show that it is possible to determine the contribution of isotropic flows and infer the DT burn-averaged thermal ion temperature. The contribution of large isotropic flows on driving the ratio of DD to DT neutron-inferred ion temperatures well below unity and approaching the lower bound of 0.8 is demonstrated in multimode simulations. The minimum DD neutron-inferred ion temperature is determined from the velocity variance analysis, accounting for the presence of isotropic flows. Being close to the DT burn-averaged thermal ion temperature, the inferred DD minimum ion temperatures demonstrate a strong correlation with the experimental yields in the OMEGA implosion database. An analytical expression is also derived to explain the effect of mode ℓ=1 ion-temperature measurement asymmetry on yield degradations caused by the anisotropic flows.

Designing a large-scale public transport network using agent-based microsimulation

Abstract An agent-based simulation framework is extended to design efficient large-scale public transport networks. It goes beyond existing approaches by incorporating a dynamic demand response towards both changes in the network and exogenous factors. The framework is based on an agent-based (MATSim) simulation and tested for the city of Zurich. In contrast to most existing public transport network optimization approaches, this framework is part of a city-level, multi-modal transport simulation tool. Compared to the existing public transport system, it proposes a sparser network with smaller vehicles and substantially higher frequencies. By doing so, the approach predicts a higher transit ridership at a lower level of subsidies. Moreover, it reliably identifies corridors for potential capacity upgrades. The method may help transport planners to assess their existing public transport networks and to plan public transport infrastructure for the era of automated vehicles.

P094: Use of high fidelity simulation to improve quality of care within Correction Canada's maximum security facilities: A Canada's first

Innovation Concept: Nurses working in corrections facilities are routinely faced with acute care scenarios requiring skilled management. There are also increasing numbers of inmates with chronic health conditions and acute exacerbations. Correctional Service Canada (CSC) has partnered with the Clinical Simulation Lab at Queen's University to develop a simulation-based training program aimed at improving acute care skills of Corrections nurses and staff. This novel quality improvement program encompasses a range of presentations that commonly occur in correctional environments. Methods: The program consisted of two laboratory sessions focused on acute care and trauma followed by an in-situ simulation session. The sessions were organized around the 4-component instructional design that enhances complex learning. Both lab sessions began with scaffolded part-task training (IV insertion, ECG interpretation, airway, circulatory support, etc) and then progressed to six team-based high-fidelity simulations that covered cardiac arrhythmias, hypoglycemia, agitated delirium, drug overdoses, and immediate trauma management. Participants rated the effectiveness of each session. Lastly, an in-situ session was conducted at the Millhaven maximum security facility for nursing and correctional staff. It comprised of five scenarios that incorporated actors, a high-fidelity manikin, and simulated security issues. Participants completed a validated self-assessment before and after the session grading themselves on aspects of acute care. Curriculum, Tool, or Material: Our multi-modal simulation curriculum enhanced self-assessed knowledge of CSC learners. Of 71 attendees in the acute care skills session, 70 agreed or strongly agreed that the exercise enhanced their knowledge, satisfied their expectations, and conveyed information applicable to their practice. All 13 participants in the trauma session agreed or strongly agreed to these sentiments. We used Wilcox signed rank test item by item on the in-situ questionnaire. There was significant improvement in majority of skills sampled: airway management, O2 delivery, team organization and assessment/treatment of cardiac arrest. Conclusion: This initiative is the first time high-fidelity simulation training has been used with Corrections nurses and the first in-situ simulation in a maximum security institution in Canada. The sessions were well-liked by participants and were assessed as very effective, validating the demand for further implementation of clinical simulation in correctional facilities.

A Physics-based Virtual Reality Simulation Framework for Neonatal Endotracheal Intubation.

Neonatal endotracheal intubation (ETI) is a complex procedure. Low intubation success rates for pediatric residents indicate the current training regimen is inadequate for achieving positive patient out-comes. Computer-based training systems in this field have been limited due to the complex nature of simulating in real-time, the anatomical structures, soft tissue deformations and frequent tool interactions with large forces which occur during actual patient intubation. This paper addresses the issues of neonatal ETI training in an attempt to bridge the gap left by traditional training methods. We propose a fully interactive physics-based virtual reality (VR) simulation framework for neonatal ETI that converts the training of this medical procedure to a completely immersive virtual environment where both visual and physical realism were achieved. Our system embeds independent dynamics models and interaction devices in separate modules while allowing them to interact with each other within the same environment, which offers a flexible solution for multi-modal medical simulation scenarios. The virtual model was extracted from CT scans of a neonatal patient, which provides realistic anatomical structures and was parameterized to allow variations in a range of features that affect the level of difficulty. Moreover, with this manikin-free VR system, we can capture and visualize an even larger set of performance parameters in relation to the internal geometric change of the virtual model for real-time guidance and post-trial assessment. Lastly, validation study results from a group of neonatologists are presented demonstrating that VR is a promising platform to train medical professionals effectively for this procedure.

Theory Analysis of Nonlinear Excitation of Second Harmonic THz Gyrotron for DNP-NMR

As an important parameter, start current reveals the excitation condition of cavity modes. Normally, the method of successive iterations with one mode associated in the calculation is used to get the start current, which just reflects the self-excitation conditions in the presence of single mode. Nevertheless, in many cases, the prior-excited mode may affect the start current of the subsequent ones. In this article, we re-derived electron motion equations with two modes involved in the calculation and calculated the start current numerically based on those equations. We analyzed start currents of operation mode TE26+ and parasitic modes of a 394-GHz gyrotron with the two methods. In the calculation using the conventional method, TE26+ satisfies self-excitation condition while TE26− does not. In the calculation using the latter method, the start current of TE26− decreases under the influence of TE26+. This nonlinear oscillation of TE26− is further observed in time domain multimode simulation. In practical application, the beam velocity spread, ohmic loss, and high-frequency loss are inevitable. We studied their effects on mode interaction and then optimized the operation parameters. When the equivalent conductivity is $1.7e^{7}~\text {s/m}$ and beam velocity spread is 0.03, the optimized output power is 149.2 W.

Development and evaluation of a multimodality simulation disaster education and training program for hospital nurses.

To develop a multimodality simulation program for hospital nurses to enhance their disaster competency and evaluate the effect of the program. The program implementation started in October 2016 and ended in December 2016. It was developed using the ADDIE model (analysis, design, development, implementation, and evaluation). Evaluation consisted of formative assessment and summative assessment. Formative assessment was performed during triage, crisis management, and problem-solving simulation programs through direct feedback and debriefing from the teacher. Summative assessment was performed using the Kirkpatrick curriculum evaluation framework. Needs assessment using the modified Delphi survey resulted in these competencies for hospital disaster nursing: triage, incident command, surge capacity, life-saving procedures, and special situations. Each competency was matched with the appropriate simulation modalities. A total of 40 emergency nurses participated in the study program. The evaluation of the program resulted in improvement in perception, crisis management, problem solving, and technical skills in disaster nursing. Multimodality simulation training program was developed to enhance the competency of hospital nurses in disaster response. All participants improved their disaster response competencies significantly. The program that was developed in this study could be used as a fundamental tool in future research in disaster curriculum development.

Multimode Control and Simulation of 6-DOF Robotic Arm in ROS

Multimode Control and Simulation of 6-DOF Robotic Arm in ROS

Mapping the Expert Mind: Integration Method for Revising the ACES Medical Simulation Curriculum.

Purpose:This article shares our experience developing an integrated curriculum for the ACES (Acute Critical Event Simulation) program. The purpose of the ACES program is to ensure that health care providers develop proficiency in the early management of critically ill patients. The program includes multiple different types of educational interventions (mostly simulation-based) and targets both specialty and family physicians practicing in tertiary and community hospitals.Methods:To facilitate integration between different educational interventions, we developed a knowledge repository consisting of cognitive sequence maps that make explicit the flow of cognitive activities carried out by experts facing different situations - the sequence maps then serving as the foundation upon which multimodal simulation scenarios would be built. To encourage participation of experts, we produced this repository as a peer-reviewed ebook. Five national organizations collaborated with the Royal College of Physicians and Surgeons of Canada to identify and recruit expert authors and reviewers. Foundational chapters, centered on goals/interventions, were first developed to comprehensively address most tasks conducted in the early management of a critically ill patient. Tasks from the foundational chapters were then used to complete the curriculum with situations. The curriculum development consisted of two-phases each followed by a peer-review process. In the first phase, focus groups using web-conferencing were conducted to map clinical practice approaches and in the second, authors completed the body of the chapter (e.g., introduction, definition, concepts, etc.) then provided a more detailed description of each task linked to supporting evidence.Results:Sixty-seven authors and thirty-five peer reviewers from various backgrounds (physicians, pharmacists, nurses, respiratory therapists) were recruited. On average, there were 32 tasks and 15 situations per chapter. The average number of focus group meetings needed to develop a map (one map per chapter) was 6.7 (SD ± 3.6). We found that the method greatly facilitated integration between different chapters especially for situations which are not limited to a single goal or intervention. For example, almost half of the tasks of the Hypercapnic Ventilatory Failure chapter map were borrowed from other maps with some modifications, which significantly reduced the authors’ workload and enhanced content integration. This chapter was also linked to 6 other chapters.Conclusions:To facilitate curriculum integration, we have developed a knowledge repository consisting of cognitive maps which organize time-sensitive tasks in the proper sequence; the repository serving as the foundation upon which other educational interventions are then built. While this methodology is demanding, authors welcomed the challenge given the scholarly value of their work, thus creating an interprofessional network of educators across Canada.

EACVI communication paper: first international young dedicated multimodal cardiovascular imaging simulation education event organized by the ESC

EACVI communication paper: first international young dedicated multimodal cardiovascular imaging simulation education event organized by the ESC

Stability and Multimode Simulation Studies of ${W}$ -Band Uniformly Dielectric-Loaded Gyrotron Traveling-Wave Tube Amplifier

In this article, a nonlinear self-consistent, multimode analysis, and particle-in-cell (PIC) simulation of a uniformly dielectric-loaded (UDL) millimeter-wave gyrotron traveling-wave tube (gyro-TWT) amplifier has been discussed. A single-anode magnetron injection electron gun is designed to produce a relativistic electron beam of 100 kV and 5 A with a unity velocity ratio and 5% of axial velocity spread. The desired operating mode TE01 is fed by converting the TE10 rectangular waveguide mode through the Y-shaped power transducer. Both the multimode theory and PIC simulation results are agreed and predicted the saturated RF power of ~140 and ~145 kW at 92 GHz, respectively. A saturated gain of ~51 dB, a 3-dB bandwidth of ~5%, and a power conversion efficiency of ~28% are obtained. To collect the spent electrons, a collector is designed by using electron optics, E-GUN. The maximum heat wall loading at the collector surface due to a spent beam is calculated as 0.255 kW/cm2.

Acceptable Planning: Influencing Individual Behavior to Reduce Transportation Energy Expenditure of a City

Our research aims at developing intelligent systems to reduce the transportation-related energy expenditure of a large city by influencing individual behavior. We introduce Copter - an intelligent travel assistant that evaluates multi-modal travel alternatives to find a plan that is acceptable to a person given their context and preferences. We propose a formulation for acceptable planning that brings together ideas from AI, machine learning, and economics. This formulation has been incorporated in Copter that produces acceptable plans in real-time. We adopt a novel empirical evaluation framework that combines human decision data with a high fidelity multi-modal transportation simulation to demonstrate a 4% energy reduction and 20% delay reduction in a realistic deployment scenario in Los Angeles, California, USA.
 
 This article is part of the special track on AI and Society.

Evaluation of internal fit, marginal integrity and fatigue resistance of E-max CAD crowns on two different preparation designs for maxillary anterior teeth. An Invitro study

Statement of the problem: Preservation of the cingulum in anterior teeth have been recommended however with recent ceramic restorations its contribution to internal adaptation and fatigue resistance needs further study.Objective: The purpose of this in-vitro study was to evaluate the internal fit, marginal integrity and the fatigue resistance of E-max CAD crowns on two preparation designs for maxillary anterior teeth.Material and methods: Twenty defect free human maxillary central incisors were prepared to receive E-max CAD ceramic crowns. 10 samples were prepared with parallel labiolingual wall (anatomic) group A and 10 samples were prepared with elimination of the cingulum (non-anatomic) group B. Scanning was done using powder free Identica hybrid scanner (Medit 02855] 23, Inchon-ro 22-gil, Seongbuk-gu, Seoul, Korea), designing was made by Exocad software version 2016 (Exocad Gmbh Julius-Reiber-Strabe 37, 64293 Darmstadt, Germany) then the restoration was milled by Roland DWX-510 milling machine (15363 barranca Parkway Irvine, California 92618) from E-max CAD blocks (LT) (Ivoclar Vivadent AG, 9494 Schaan, Princiability of Liechtenstein). Internal fit, marginal adaptation was measured before cementation using replica technique on prepared tooth using stereomicroscope. Duplication of the preparation was made in order to get epoxy resin dies for crown cementation, then restorations were cemented on the corresponding epoxy resin die and marginal adaptation was reevaluated under stereomicroscope. Specimens were then subjected to thermomechanical aging using four stations multimodal ROBOTA chewing simulator (Model ACH-09075DC-T, AD-TECH TECHNOLOGY CO., LTD., GERMANY) followed by fatigue resistance measurement using universal testing machine (Model 3345; Instron Industrial Products, Norwood, MA, USA). Results: It was found that group B recorded statistically significant (P 0.05) higher marginal gap mean value (37.15±5.34 µm) than group A (34.2±4.84 µm). while for the internal adaptation it was found that group A recorded statistically significant higher internal gap mean value (91.93±17.41 µm) than group B (57.97±14.08 µm). It was found that Group B recorded statistically non-significant higher fatigue resistance mean value (1130.58±31.53N) than Group A (1114.84±45.04N). Conclusion: Different preparation designs affect the marginal adaptation of the restoration which was statistically significant only before cementation. The non-anatomic group (B) showed statistically significant lower internal gap than anatomic group (A). While there was no significant difference in the fatigue resistance of both groups after thermocyclic loading.

Dynamic, multi- and intermodal bike sharing in agent-based modelling

Negative effects of traffic, like congestion, air and noise pollution are among the reasons why environmentally friendly solutions are promoted. Bike sharing (bs) is intended to strengthen cycling and public transport. Nevertheless, current transport models rarely consider cycling or even bs, in either detail or holistically. In this paper we present an agent based approach to model cycling and in particular bs within the multimodal simulation environment MATSim. Multimodal trips combining public transport and bs are included as well as within day rescheduling of bs trips as agents may not find a bike or empty return space (parking spot). To minimize such cases, choice probabilities were implemented, so that agents only start their bs trip, if sufficient bikes or parking spots are available. The modules presented in this paper were applied using a MATSim model of the city of Vienna. Agent based bs modelling is an inexpensive option to test the impact of a bike sharing system before implementation.

Reducing Perineal Lacerations Through Team-Based Simulation.

Vaginal deliveries that result in perineal trauma involve significant morbidity to women. Multiple strategies have been identified to reduce the risk of severe perineal lacerations. The objective of this study was to evaluate the effectiveness of an interprofessional simulation-based teams-training program aimed at reducing severe perineal lacerations during childbirth. A quasi-experimental pre-post single-group design was used to examine the performance of labor and delivery personnel at a large multihospital system after participating in a mixed-modality simulation program for reducing perineal lacerations. Multiple educational strategies aimed at management of second stage of labor (including laboring down, warm compresses, coaching, positioning, perineal support, controlled delivery of fetal head, and mediolateral episiotomy techniques) were taught using patients, task trainers, and a standardized curriculum during interprofessional educational sessions. Primary study outcomes were as follows: (a) pre-post differences in knowledge; (b) pre-post differences in team performance assessments; and (c) pre-post differences in safety culture. Secondary outcomes were severe perineal laceration rates. During an 18-month period, 675 personnel in 4 hospitals participated in the program. Significant improvement was noted in pre-post scores of knowledge (59.86%, 93.87%, P < 0.0001), performance (36.54%, 93.45%, P < 0.0001), and safety culture (3.24, 1.45, 1 = high, 5 = low, P < 0.0001). Severe perineal laceration rates decreased by 33.38% since initiation. Rates fluctuated with the addition of new personnel and renewed educational programs. A multimodal interprofessional simulation program of strategies to prevent severe perineal lacerations significantly improved knowledge, skills, and attitudes in labor and delivery personnel within a healthcare system. Severe perineal laceration rates were reduced.

GEMSim: A GPU-accelerated multi-modal mobility simulator for large-scale scenarios

In order to accelerate large-scale agent-based mobility scenarios, and to provide advanced traffic simulation and forecasting tools for planners and decision makers, a GPU-accelerated (graphics processing unit) simulation platform, GEMSim, has been developed. GEMSim incorporates a mesoscopic, multi-modal, queue-based mobility simulator implemented on a GPU, including a detailed public transit model. Until now, no integrated solutions to run large-scale multi-modal mobility scenarios on a GPU have been presented. The simulator exploits activity-based demand modelling to consider human patterns of behaviour and to make scenarios more realistic in a sense of emerging transportation modes and mobility services. A large-scale scenario for Switzerland with detailed road infrastructure, public transit schedule and up to 5.2 million of agents with individual daily plans has been used to validate and to assess performance of GEMSim and to compare it with one of the most advanced existing agent-based simulators for transportation (MATSim). A factor of 68 speedup was achieved along with reduction in memory usage as a factor of 5, making it possible to simulate a full day of the whole Switzerland in less than 5 minutes even on a decent workstation.

The 2019 WACEM Expert Document on Hybrid Simulation for Transforming Health-care Simulation Through "Mixing and Matching".

With the multitude of options available under the umbrella of “simulation” today, we have a larger repertoire of choices in our educational journey and outreach. These provide a platform for us to really transform health-care simulation from the traditional, unimodality simulation, to more complex, high fidelity, integrated, and engaging multimodality techniques. The main thrust must be to enhance clinical decision-making in patient care, to solve real-world clinical problems. Hybrid simulation (HS) utilizes at least two different simulation modalities, whereby combining them will enable one type of simulation modality to enhance the other, with the proper alignment, coordination, and interfacing between the modalities. Although the term is often used interchangeably, HS is slightly different from multimodality simulation. The latter refers to the use of multiple types of simulation in the same scenario or place. The main objectives for using HS have to be as follows: (1) for the acquisition of knowledge and skills by the best combination of methodologies, (2) for clinical performance improvement at all levels of care through the creation of as close as possible to real-world situation and problems, (3) to be able to sustain motivation and passion of our spectrum learners in their educational continuum, and (4) to provide a rich, exciting, and stimulating learning platform and environment, which can trigger deep learning and understanding. This article will also share some examples and cases utilizing HS in transforming health-care simulation.

The MATSim Open Berlin Scenario: A multimodal agent-based transport simulation scenario based on synthetic demand modeling and open data

With more diverse transport policies being proposed and the advent of novel transport services and technologies, the transport system is becoming more individualized in many aspects. Transport models, the most important tool to assess policies and schemes, need to be sufficiently expressive to address these developments. Agent-based transport models, where travelers with individual properties and the ability to act and decide autonomously are resolved individually, allow to appropriately model and analyze such policies. This paper describes the MATSim Open Berlin Scenario, a transport simulation scenario for the Berlin metropolitan area implemented in the agent-based transport simulation framework MATSim. The scenario is solely based on open data and the demand for transport is created based on a fully synthetic procedure. Contrary to most transport simulation scenarios, no information from a travel diary survey is required as input. As such, the scenario generation procedure described in this study is spatially transferable and facilitates the creation of agent-based transport simulation scenarios for arbitrary regions.

VIOLA-A Multi-Purpose and Web-Based Visualization Tool for Neuronal-Network Simulation Output.

Neuronal network models and corresponding computer simulations are invaluable tools to aid the interpretation of the relationship between neuron properties, connectivity, and measured activity in cortical tissue. Spatiotemporal patterns of activity propagating across the cortical surface as observed experimentally can for example be described by neuronal network models with layered geometry and distance-dependent connectivity. In order to cover the surface area captured by today's experimental techniques and to achieve sufficient self-consistency, such models contain millions of nerve cells. The interpretation of the resulting stream of multi-modal and multi-dimensional simulation data calls for integrating interactive visualization steps into existing simulation-analysis workflows. Here, we present a set of interactive visualization concepts called views for the visual analysis of activity data in topological network models, and a corresponding reference implementation VIOLA (VIsualization Of Layer Activity). The software is a lightweight, open-source, web-based, and platform-independent application combining and adapting modern interactive visualization paradigms, such as coordinated multiple views, for massively parallel neurophysiological data. For a use-case demonstration we consider spiking activity data of a two-population, layered point-neuron network model incorporating distance-dependent connectivity subject to a spatially confined excitation originating from an external population. With the multiple coordinated views, an explorative and qualitative assessment of the spatiotemporal features of neuronal activity can be performed upfront of a detailed quantitative data analysis of specific aspects of the data. Interactive multi-view analysis therefore assists existing data analysis workflows. Furthermore, ongoing efforts including the European Human Brain Project aim at providing online user portals for integrated model development, simulation, analysis, and provenance tracking, wherein interactive visual analysis tools are one component. Browser-compatible, web-technology based solutions are therefore required. Within this scope, with VIOLA we provide a first prototype.

Properties of the signal mode in the polariton optical parametric oscillator regime

Theoretical analyses of the polariton optical parametric oscillator (OPO) regime often rely on a mean field approach based on the complex Gross-Pitaevskii equations in a three-mode approximation, where only three momentum states, the signal, pump and idler, are assumed to be significantly occupied. This approximation, however, lacks a constraint to uniquely determine the signal and idler momenta. In contrast, multimode numerical simulations and experiments show a unique momentum structure for the OPO states. In this work we show that an estimate for the signal momentum chosen by the system can be found from a simple analysis of the pump-only configuration. We use this estimate to investigate how the chosen signal momentum depends on the properties of the drive.

Modeling Framework and Implementation of Activity- and Agent-Based Simulation: An Application to the Greater Boston Area

This paper presents a utility-maximizing approach to agent-based modeling with an application to the Greater Boston Area (GBA). It leverages day activity schedules (DAS) to create a framework for representing travel demand in an individual’s day. DAS are composed of a sequence of stops that make up home-based tours with activity purposes, intermediate stops, and subtours. The framework introduced in this paper includes three levels: (1) the Day Pattern Level, which determines if an individual will travel and, if so, what types of primary activities and intermediate stops they will do; (2) the Tour Level, which models the mode, destination, and time-of-day of the different primary activities; and (3) the Intermediate Stop Level, which generates intermediate stops. The models are estimated for the GBA using the 2010 Massachusetts Travel Survey (MTS). They are then implemented in SimMobility, the agent-based, activity-based, multimodal simulator. It run in a microsimulation using a Synthetic Population. Produced results are consistent with the MTS. Compared with similar activity-based approaches, the proposed framework allows for more flexibility in modeling a wide range of activity and travel patterns.