633,036 research outputs found
Cursor control by point-of-regard estimation for a computer with integrated webcam
This work forms part of the project Eye-Communicate funded by the Malta Council for Science and Technology through the National Research & Innovation Programme (2012) under Research Grant No. R&I-2012-057.The problem of eye-gaze tracking by videooculography has been receiving extensive interest throughout the years owing to the wide range of applications associated with this technology. Nonetheless, the emergence of a new paradigm referred to as pervasive eye-gaze tracking, introduces new challenges that go beyond the typical conditions for which classical video-based eye- gaze tracking methods have been developed. In this paper, we propose to deal with the problem of point-of-regard estimation from low-quality images acquired by an integrated camera inside a notebook computer. The proposed method detects the iris region from low-resolution eye region images by its intensity values rather than the shape, ensuring that this region can also be detected at different angles of rotation and under partial occlusion by the eyelids. Following the calculation of the point- of-regard from the estimated iris center coordinates, a number of Kalman filters improve upon the noisy point-of-regard estimates to smoothen the trajectory of the mouse cursor on the monitor screen. Quantitative results obtained from a validation procedure reveal a low mean error that is within the footprint of the average on-screen icon.peer-reviewe
Scribble vectorization using concentric sampling circles
In this paper we introduce a path extraction algorithm for multi-stroke scribbled paths by making use of path-centred concentric sampling circles. Circle and line geometry is then exploited to efficiently obtain piece-wise linear models of the multi-stroke segments in the drawing. Parzen-window estimation is used to obtain the probability distribution of the grey-level profile of the sampling circles to determine the intersecting angle of the sampling circle with the stroke segments and hence determine the line model parameters. The results obtained show that the algorithm identifies the line models accurately while reducing considerably the computational time required to obtain the line models.peer-reviewe
NASA's supercomputing experience
A brief overview of NASA's recent experience in supercomputing is presented from two perspectives: early systems development and advanced supercomputing applications. NASA's role in supercomputing systems development is illustrated by discussion of activities carried out by the Numerical Aerodynamical Simulation Program. Current capabilities in advanced technology applications are illustrated with examples in turbulence physics, aerodynamics, aerothermodynamics, chemistry, and structural mechanics. Capabilities in science applications are illustrated by examples in astrophysics and atmospheric modeling. Future directions and NASA's new High Performance Computing Program are briefly discussed
Statistical Analysis with Webstat, a Java applet for the World Wide Web
The Java programming language has added a new tool for delivering computing applications over the World Wide Web (WWW). WebStat is a new computing environment for basic statistical analysis which is delivered in the form of a Java applet. Anyone with WWW access and a Java capable browser can access this new analysis environment. Along with an overall introduction of the environment, the main features of this package are illustrated, and the prospect of using basic WebStat components for more advanced applications is discussed.
HSTREAM: A directive-based language extension for heterogeneous stream computing
Big data streaming applications require utilization of heterogeneous parallel
computing systems, which may comprise multiple multi-core CPUs and many-core
accelerating devices such as NVIDIA GPUs and Intel Xeon Phis. Programming such
systems require advanced knowledge of several hardware architectures and
device-specific programming models, including OpenMP and CUDA. In this paper,
we present HSTREAM, a compiler directive-based language extension to support
programming stream computing applications for heterogeneous parallel computing
systems. HSTREAM source-to-source compiler aims to increase the programming
productivity by enabling programmers to annotate the parallel regions for
heterogeneous execution and generate target specific code. The HSTREAM runtime
automatically distributes the workload across CPUs and accelerating devices. We
demonstrate the usefulness of HSTREAM language extension with various
applications from the STREAM benchmark. Experimental evaluation results show
that HSTREAM can keep the same programming simplicity as OpenMP, and the
generated code can deliver performance beyond what CPUs-only and GPUs-only
executions can deliver.Comment: Preprint, 21st IEEE International Conference on Computational Science
and Engineering (CSE 2018
Virtualizing the Stampede2 Supercomputer with Applications to HPC in the Cloud
Methods developed at the Texas Advanced Computing Center (TACC) are described
and demonstrated for automating the construction of an elastic, virtual cluster
emulating the Stampede2 high performance computing (HPC) system. The cluster
can be built and/or scaled in a matter of minutes on the Jetstream self-service
cloud system and shares many properties of the original Stampede2, including:
i) common identity management, ii) access to the same file systems, iii)
equivalent software application stack and module system, iv) similar job
scheduling interface via Slurm.
We measure time-to-solution for a number of common scientific applications on
our virtual cluster against equivalent runs on Stampede2 and develop an
application profile where performance is similar or otherwise acceptable. For
such applications, the virtual cluster provides an effective form of "cloud
bursting" with the potential to significantly improve overall turnaround time,
particularly when Stampede2 is experiencing long queue wait times. In addition,
the virtual cluster can be used for test and debug without directly impacting
Stampede2. We conclude with a discussion of how science gateways can leverage
the TACC Jobs API web service to incorporate this cloud bursting technique
transparently to the end user.Comment: 6 pages, 0 figures, PEARC '18: Practice and Experience in Advanced
Research Computing, July 22--26, 2018, Pittsburgh, PA, US
EPOBF: Energy Efficient Allocation of Virtual Machines in High Performance Computing Cloud
Cloud computing has become more popular in provision of computing resources
under virtual machine (VM) abstraction for high performance computing (HPC)
users to run their applications. A HPC cloud is such cloud computing
environment. One of challenges of energy efficient resource allocation for VMs
in HPC cloud is tradeoff between minimizing total energy consumption of
physical machines (PMs) and satisfying Quality of Service (e.g. performance).
On one hand, cloud providers want to maximize their profit by reducing the
power cost (e.g. using the smallest number of running PMs). On the other hand,
cloud customers (users) want highest performance for their applications. In
this paper, we focus on the scenario that scheduler does not know global
information about user jobs and user applications in the future. Users will
request shortterm resources at fixed start times and non interrupted durations.
We then propose a new allocation heuristic (named Energy-aware and Performance
per watt oriented Bestfit (EPOBF)) that uses metric of performance per watt to
choose which most energy-efficient PM for mapping each VM (e.g. maximum of MIPS
per Watt). Using information from Feitelson's Parallel Workload Archive to
model HPC jobs, we compare the proposed EPOBF to state of the art heuristics on
heterogeneous PMs (each PM has multicore CPU). Simulations show that the EPOBF
can reduce significant total energy consumption in comparison with state of the
art allocation heuristics.Comment: 10 pages, in Procedings of International Conference on Advanced
Computing and Applications, Journal of Science and Technology, Vietnamese
Academy of Science and Technology, ISSN 0866-708X, Vol. 51, No. 4B, 201
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