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Interactive Simulation (interactive + simulation)

Distribution by Scientific Domains

Information Science and Computing	46%

Selected Abstracts

STRANDS: Interactive Simulation of Thin Solids using Cosserat Models

COMPUTER GRAPHICS FORUM, Issue 3 2002
Dinesh K. Pai
Strandsare thin elastic solids that are visually well approximated as smooth curves, and yet possess essential physical behaviors characteristic of solid objects such as twisting. Common examples in computer graphics include: sutures, catheters, and tendons in surgical simulation; hairs, ropes, and vegetation in animation. Physical models based on spring meshes or 3D finite elements for such thin solids are either inaccurate or inefficient for interactive simulation. In this paper we show that models based on the Cosserat theory of elastic rods are very well suited for interactive simulation of these objects. The physical model reduces to a system of spatial ordinary differential equations that can be solved efficiently for typical boundary conditions. The model handles the important geometric non-linearity due to large changes in shape. We introduce Cosserat-type physical models, describe efficient numerical methods for interactive simulation of these models, and implementation results. [source]

HLA real-time extension

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 15 2004
Hui Zhao
Abstract The IEEE 1516 Standard ,High Level Architecture (HLA)' and its implementation ,Run-Time Infra-structure (RTI)' defines a general-purpose network communication mechanism for Distributed Interactive Simulation (DIS). However, it does not address real-time requirements of DIS. Current operating system technologies can provide real-time processing through some real-time operating systems (RTOSs) and the Internet is also moving to an age of Quality of Service (QoS), providing delay and jitter bounded services. With the availability of RTOSs and IP QoS, it is possible for HLA to be extended to take advantage of these technologies in order to construct an architecture for Real-Time DIS (RT-DIS). This extension will be a critical aspect of applications in virtual medicine, distributed virtual environments, weapon simulation, aerospace simulation and others. This paper outlines the current real-time technology with respect to operating systems and at the network infrastructure level. After summarizing the requirements and our experiences with RT-DIS, we present a proposal for HLA real-time extension and architecture for real-time RTI. Similar to the growth of real-time CORBA (Common Object Request Broker) after the mature based CORBA standard suite, Real-Time HLA is a natural extension following the standardization of HLA into IEEE 1516 in September 2000. Copyright © 2004 John Wiley & Sons, Ltd. [source]

Virtual Reality and Interactive Simulation for Pain Distraction

PAIN MEDICINE, Issue 2007
Mark D. Wiederhold MD
ABSTRACT Pain and discomfort are perceptible during many medical procedures. In the past, drugs have been the conventional means to alleviate pain, but in many instances, medications by themselves do not provide optimal results. Current advances are being made to control pain by integrating both the science of pain medications and the science of the human mind. Various psychological techniques, including distraction by virtual reality environments and the playing of video games, are being employed to treat pain. In virtual reality environments, an image is provided for the patient in a realistic, immersive manner devoid of distractions. This technology allows users to interact at many levels with the virtual environment, using many of their senses, and encourages them to become immersed in the virtual world they are experiencing. When immersion is high, much of the user's attention is focused on the virtual environment, leaving little attention left to focus on other things, such as pain. In this way virtual reality provides an effective medium for reproducing and/or enhancing the distractive qualities of guided imagery for the majority of the population who cannot visualize successfully. [source]

A programming environment for behavioural animation

COMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2002
Frédéric Devillers
Abstract Behavioural models offer the ability to simulate autonomous agents like organisms and living beings. Psychological studies have shown that human behaviour can be described by a perception,decision,action loop, in which the decisional process should integrate several programming paradigms such as real time, concurrency and hierarchy. Building such systems for interactive simulation requires the design of a reactive system treating flows of data to and from the environment, and involving task control and preemption. Since a complete mental model based on vision and image processing cannot be constructed in real time using purely geometrical information, higher levels of information are needed in a model of the virtual environment. For example, the autonomous actors of a virtual world would exploit the knowledge of the environment topology to navigate through it. Accordingly, in this paper we present our programming environment for real-time behavioural animation which is compounded of a general animation and simulation platform, a behavioural modelling language and a scenario-authoring tool. Those tools has been used for different applications such as pedestrian and car driver interaction in urban environments, or a virtual museum populated by a group of visitors. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Scalable real-time animation of rivers

COMPUTER GRAPHICS FORUM, Issue 2 2009
Qizhi Yu
Many recent games and applications target the interactive exploration of realistic large scale worlds. These worlds consist mostly of static terrain models, as the simulation of animated fluids in these virtual worlds is computationally expensive. Adding flowing fluids, such as rivers, to these virtual worlds would greatly enhance their realism, but causes specific issues: as the user is usually observing the world at close range, small scale details such as waves and ripples are important. However, the large scale of the world makes classical methods impractical for simulating these effects. In this paper, we present an algorithm for the interactive simulation of realistic flowing fluids in large virtual worlds. Our method relies on two key contributions: the local computation of the velocity field of a steady flow given boundary conditions, and the advection of small scale details on a fluid, following the velocity field, and uniformly sampled in screen space. [source]

STRANDS: Interactive Simulation of Thin Solids using Cosserat Models

The Polder Computing Environment: a system for interactive distributed simulation

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 13-15 2002
K. A. Iskra
Abstract The paper provides an overview of an experimental, Grid-like computing environment, Polder, and its components. Polder offers high-performance computing and interactive simulation facilities to computational science. It was successfully implemented on a wide-area cluster system, the Distributed ASCI Supercomputer. An important issue is an efficient management of resources, in particular multi-level scheduling and migration of tasks that use PVM or sockets. The system can be applied to interactive simulation, where a cluster is used for high-performance computations, while a dedicated immersive interactive environment (CAVE) offers visualization and user interaction. Design considerations for the construction of dynamic exploration environments using such a system are discussed, in particular the use of intelligent agents for coordination. A case study of simulatedabdominal vascular reconstruction is subsequently presented: the results of computed tomography or magnetic resonance imaging of a patient are displayed in CAVE, and a surgeon can evaluate the possible treatments by performing the surgeries virtually and analysing the resulting blood flow which is simulated using the lattice-Boltzmann method. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Developing An HLA-Based Naval Maneuvering Simulation

NAVAL ENGINEERS JOURNAL, Issue 1 2005
Okan Topçu
This paper discusses the main issues involved in developing a high level architecture (HLA)-based distributed simulation while presenting an application called Naval Surface Tactical Maneuvering Simulation System (NSTMSS), which is intended to serve as a testbed for HLA and distributed interactive simulation (DIS) research. NSTMSS provides a networked virtual environment (NVE) for naval surface actions in which new formations can be evaluated and tested and present ones can be practiced and analyzed. This paper also describes a development lifecycle for HLA-based distributed interactive simulations and reflects best practices. [source]

Creating the Potential for Organizational Learning Through Interactive Simulation Debriefing Sessions

PERFORMANCE IMPROVEMENT QUARTERLY, Issue 3 2001
Michael D. Proctor
ABSTRACT High-end and high-cost technologies such as interactive simulation are increasingly being applied to government operations such as police, emergency management, SWAT, and fire fighter training to maintain readiness and improve performance. The simulation experience, when combined with after-training debriefing sessions, creates the potential for organizational learning. This research reports findings from field observations of debriefing sessions following organizational operations in interactive simulation systems. The findings focus on the relationship of different debriefing session techniques to identification of potential organizational learning opportunities. [source]

From anytime, anywhere to all-the-time, everywhere: Learning objects, broadband and wireless reshape digital libraries for learning and research.

PROCEEDINGS OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE & TECHNOLOGY (ELECTRONIC), Issue 1 2003
Sponsored by SIG STI
Learning objects are among the latest types of materials to be included in digital libraries. These are small portions of lesson material designed to be used in multiple configurations for multiple instructional applications, ranging from distance learning to interactive simulation. As broadband and wireless technologies change the expectations and performance patterns of the user, learning objects change the nature of content and the way that it must be managed. The size and diversity of digital collections affect the options through which these materials can be accessed. Many libraries are offering wireless access to their networks and many individuals are accessing digital libraries off-site using broadband technologies. Each of these trends affects decisions made for collection development, portal design and network design, and those decisions dictate specific technological requirements for access. This panel session highlights management and infrastructure issues of digital libraries as they relate to learning objects, broadband and wireless technologies. [source]

Complex molecular assemblies at hand via interactive simulations

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 15 2009
Olivier Delalande
Abstract Studying complex molecular assemblies interactively is becoming an increasingly appealing approach to molecular modeling. Here we focus on interactive molecular dynamics (IMD) as a textbook example for interactive simulation methods. Such simulations can be useful in exploring and generating hypotheses about the structural and mechanical aspects of biomolecular interactions. For the first time, we carry out low-resolution coarse-grain IMD simulations. Such simplified modeling methods currently appear to be more suitable for interactive experiments and represent a well-balanced compromise between an important gain in computational speed versus a moderate loss in modeling accuracy compared to higher resolution all-atom simulations. This is particularly useful for initial exploration and hypothesis development for rare molecular interaction events. We evaluate which applications are currently feasible using molecular assemblies from 1900 to over 300,000 particles. Three biochemical systems are discussed: the guanylate kinase (GK) enzyme, the outer membrane protease T and the soluble N -ethylmaleimide-sensitive factor attachment protein receptors complex involved in membrane fusion. We induce large conformational changes, carry out interactive docking experiments, probe lipid,protein interactions and are able to sense the mechanical properties of a molecular model. Furthermore, such interactive simulations facilitate exploration of modeling parameters for method improvement. For the purpose of these simulations, we have developed a freely available software library called MDDriver. It uses the IMD protocol from NAMD and facilitates the implementation and application of interactive simulations. With MDDriver it becomes very easy to render any particle-based molecular simulation engine interactive. Here we use its implementation in the Gromacs software as an example. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2009 [source]