7,796 research outputs found
Hardware acceleration of reaction-diffusion systems:a guide to optimisation of pattern formation algorithms using OpenACC
Reaction Diffusion Systems (RDS) have widespread applications in computational ecology, biology, computer graphics and the visual arts. For the former applications a major barrier to the development of effective simulation models is their computational complexity - it takes a great deal of processing power to simulate enough replicates such that reliable conclusions can be drawn. Optimizing the computation is thus highly desirable in order to obtain more results with less resources. Existing optimizations of RDS tend to be low-level and GPGPU based. Here we apply the higher-level OpenACC framework to two case studies: a simple RDS to learn the ‘workings’ of OpenACC and a more realistic and complex example. Our results show that simple parallelization directives and minimal data transfer can produce a useful performance improvement. The relative simplicity of porting OpenACC code between heterogeneous hardware is a key benefit to the scientific computing community in terms of speed-up and portability
Inviwo -- A Visualization System with Usage Abstraction Levels
The complexity of today's visualization applications demands specific
visualization systems tailored for the development of these applications.
Frequently, such systems utilize levels of abstraction to improve the
application development process, for instance by providing a data flow network
editor. Unfortunately, these abstractions result in several issues, which need
to be circumvented through an abstraction-centered system design. Often, a high
level of abstraction hides low level details, which makes it difficult to
directly access the underlying computing platform, which would be important to
achieve an optimal performance. Therefore, we propose a layer structure
developed for modern and sustainable visualization systems allowing developers
to interact with all contained abstraction levels. We refer to this interaction
capabilities as usage abstraction levels, since we target application
developers with various levels of experience. We formulate the requirements for
such a system, derive the desired architecture, and present how the concepts
have been exemplary realized within the Inviwo visualization system.
Furthermore, we address several specific challenges that arise during the
realization of such a layered architecture, such as communication between
different computing platforms, performance centered encapsulation, as well as
layer-independent development by supporting cross layer documentation and
debugging capabilities
Creating and controlling visual environments using BonVision.
Real-time rendering of closed-loop visual environments is important for next-generation understanding of brain function and behaviour, but is often prohibitively difficult for non-experts to implement and is limited to few laboratories worldwide. We developed BonVision as an easy-to-use open-source software for the display of virtual or augmented reality, as well as standard visual stimuli. BonVision has been tested on humans and mice, and is capable of supporting new experimental designs in other animal models of vision. As the architecture is based on the open-source Bonsai graphical programming language, BonVision benefits from native integration with experimental hardware. BonVision therefore enables easy implementation of closed-loop experiments, including real-time interaction with deep neural networks, and communication with behavioural and physiological measurement and manipulation devices
Volumetric Medical Images Visualization on Mobile Devices
Volumetric medical images visualization is an important tool in the diagnosis
and treatment of diseases. Through history, one of the most dificult
tasks for Medicine Specialists has been the accurate location of broken bones
and of the damaged tissues during Chemotherapy treatment, among other
applications; like techniques used in Neurological Studies. Thus these situations
enhance the need of visualization in Medicine. New technologies,
the improvement and development of new hardware as well as software and
the updating of old ones for graphic applications have resulted in specialized
systems for medical visualization. However the use of these techniques
in mobile devices has been poor due to its low performance. In our work,
we propose a client-server scheme, where the model is compressed in the
server side and is reconstructed in a nal thin-client device. The technique
restricts the natural density values to achieve good bone visualization in
medical models, transforming the rest of the data to zero. Our proposal
uses a tridimensional Haar Wavelet Function locally applied inside units
blocks of 16x16x16, similar to the Wavelet Based 3D Compression Scheme
for Interactive Visualization of Very Large Volume Data approach. We also
implement a quantization algorithm which handles error coeficients according
to the frequency distributions of these coe cients. Finally, we made
an evaluation of the volume visualization; on current mobile devices .We
present the speci cations for the implementation of our technique in the
Nokia n900 Mobile Phone
Implementation and Applications of Art-directable Ocean Simulation Tools
Ocean effects are important aspects of the filmmaking. They help to establish emotions and dynamism via the behaviors of the oceans, and provides the different atmosphere for storytelling by creating various ocean scenarios. Gilligan is a prototype environmental scene simulator, whose core technique of the ocean simulation has been widely used in feature film productions. This thesis develops ocean simulation tools working with Maya and Houdini with the techniques provided by Gilligan. The Gilligan-Maya workflow executes ocean simulation methods in Gilligan to simulate oceans. The Gilligan-Houdini workflow integrates Gilligan into Houdini, containing a Houdini wrapper of Gilligan, along with a series of Houdini digital assets to support the usage. Artists can use these tools to generate ocean effects, with controls to simplify the production workflow, and well-exposed to all the simulation data for advanced development. This thesis demonstrates several applications with different ocean effects scenarios: ocean environment creation, ocean with floating objects, and ocean character effects
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