1,403 research outputs found
Accelerated Modeling of Near and Far-Field Diffraction for Coronagraphic Optical Systems
Accurately predicting the performance of coronagraphs and tolerancing optical
surfaces for high-contrast imaging requires a detailed accounting of
diffraction effects. Unlike simple Fraunhofer diffraction modeling, near and
far-field diffraction effects, such as the Talbot effect, are captured by
plane-to-plane propagation using Fresnel and angular spectrum propagation. This
approach requires a sequence of computationally intensive Fourier transforms
and quadratic phase functions, which limit the design and aberration
sensitivity parameter space which can be explored at high-fidelity in the
course of coronagraph design. This study presents the results of optimizing the
multi-surface propagation module of the open source Physical Optics Propagation
in PYthon (POPPY) package. This optimization was performed by implementing and
benchmarking Fourier transforms and array operations on graphics processing
units, as well as optimizing multithreaded numerical calculations using the
NumExpr python library where appropriate, to speed the end-to-end simulation of
observatory and coronagraph optical systems. Using realistic systems, this
study demonstrates a greater than five-fold decrease in wall-clock runtime over
POPPY's previous implementation and describes opportunities for further
improvements in diffraction modeling performance.Comment: Presented at SPIE ASTI 2018, Austin Texas. 11 pages, 6 figure
Accelerated CTIS Using the Cell Processor
The Computed Tomography Imaging Spectrometer (CTIS) is a device capable of simultaneously acquiring imagery from multiple bands of the electromagnetic spectrum. Due to the method of data collection from this system, a processing intensive reconstruction phase is required to resolve the image output. This paper evaluates a parallelized implementation of the Vose-Horton CTIS reconstruction algorithm using the Cell processor. In addition to demonstrating the feasibility of a mixed precision implementation, it is shown that use of the parallel processing capabilities of the Cell may provide a significant reduction in reconstruction time
Adaptive Real Time Imaging Synthesis Telescopes
The digital revolution is transforming astronomy from a data-starved to a
data-submerged science. Instruments such as the Atacama Large Millimeter Array
(ALMA), the Large Synoptic Survey Telescope (LSST), and the Square Kilometer
Array (SKA) will measure their accumulated data in petabytes. The capacity to
produce enormous volumes of data must be matched with the computing power to
process that data and produce meaningful results. In addition to handling huge
data rates, we need adaptive calibration and beamforming to handle atmospheric
fluctuations and radio frequency interference, and to provide a user
environment which makes the full power of large telescope arrays accessible to
both expert and non-expert users. Delayed calibration and analysis limit the
science which can be done. To make the best use of both telescope and human
resources we must reduce the burden of data reduction.
Our instrumentation comprises of a flexible correlator, beam former and
imager with digital signal processing closely coupled with a computing cluster.
This instrumentation will be highly accessible to scientists, engineers, and
students for research and development of real-time processing algorithms, and
will tap into the pool of talented and innovative students and visiting
scientists from engineering, computing, and astronomy backgrounds.
Adaptive real-time imaging will transform radio astronomy by providing
real-time feedback to observers. Calibration of the data is made in close to
real time using a model of the sky brightness distribution. The derived
calibration parameters are fed back into the imagers and beam formers. The
regions imaged are used to update and improve the a-priori model, which becomes
the final calibrated image by the time the observations are complete
Containing Analog Data Deluge at Edge through Frequency-Domain Compression in Collaborative Compute-in-Memory Networks
Edge computing is a promising solution for handling high-dimensional,
multispectral analog data from sensors and IoT devices for applications such as
autonomous drones. However, edge devices' limited storage and computing
resources make it challenging to perform complex predictive modeling at the
edge. Compute-in-memory (CiM) has emerged as a principal paradigm to minimize
energy for deep learning-based inference at the edge. Nevertheless, integrating
storage and processing complicates memory cells and/or memory peripherals,
essentially trading off area efficiency for energy efficiency. This paper
proposes a novel solution to improve area efficiency in deep learning inference
tasks. The proposed method employs two key strategies. Firstly, a Frequency
domain learning approach uses binarized Walsh-Hadamard Transforms, reducing the
necessary parameters for DNN (by 87% in MobileNetV2) and enabling
compute-in-SRAM, which better utilizes parallelism during inference. Secondly,
a memory-immersed collaborative digitization method is described among CiM
arrays to reduce the area overheads of conventional ADCs. This facilitates more
CiM arrays in limited footprint designs, leading to better parallelism and
reduced external memory accesses. Different networking configurations are
explored, where Flash, SA, and their hybrid digitization steps can be
implemented using the memory-immersed scheme. The results are demonstrated
using a 65 nm CMOS test chip, exhibiting significant area and energy savings
compared to a 40 nm-node 5-bit SAR ADC and 5-bit Flash ADC. By processing
analog data more efficiently, it is possible to selectively retain valuable
data from sensors and alleviate the challenges posed by the analog data deluge.Comment: arXiv admin note: text overlap with arXiv:2307.03863,
arXiv:2309.0177
Applications of GPU Computing to Control and Simulate Systems
[Abstract] This work deals with the new programming paradigm
that exploits the benefits of modern Graphics
Processing Units (GPUs), specifically their capacity
to carry heavy calculations out for simulating
systems or solving complex control strategies in real
time
Similarity of Inference Face Matching On Angle Oriented Face Recognition
Face recognition is one of the wide applications of image processing technique. In this paper complete image of face recognition algorithm is proposed. In the prepared algorithm the local information is extracted using angle oriented discrete cosine transforms and invokes certain normalization techniques. To increase the Reliability of the Face detection process, neighborhood pixel information is incorporated into the proposed method. Discrete Cosine Transform (DCT) are renowned methods are implementing in the field of access control and security are utilizing the feature extraction capabilities. But these algorithms have certain limitations like poor discriminatory power and disability to handle large computational load. The face matching classification for the proposed system is done using various distance measure methods like Euclidean Distance, Manhattan Distance and Cosine Distance methods and the recognition rate were compared for different distance measures. The proposed method has been successfully tested on image database which is acquired under variable illumination and facial expressions. It is observed from the results that use of face matching like various method gives a recognition rate are high while comparing other methods. Also this study analyzes and compares the obtained results from the proposed Angle oriented face recognition with threshold based face detector to show the level of robustness using texture features in the proposed face detector. It was verified that a face recognition based on textual features can lead to an efficient and more reliable face detection method compared with KLT (Karhunen Loeve Transform), a threshold face detector. Keywords: Angle Oriented, Cosine Similarity, Discrete Cosine Transform, Euclidean Distance, Face Matching, Feature Extraction, Face Recognition, Image texture features
Research of Order Processing Capabilities for Oscillatory Signals in Rotating Equipment
The Arnold Engineering Development Complex (AEDC) has identified a need to process data from oscillatory signals on a revolution basis, also known as order processing. Such oscillatory data is hereafter referred to as dynamic data. Order processing would serve to improve dynamic data accuracy as reported in the frequency and order domains, capture momentary integral responses, and facilitate organic comparisons between various types of oscillatory signals. Organizing data by revolutions would also be beneficial for time domain analysis.This paper explores the need for order processing, reviews similar methods employed in other data acquisition applications such as blade tip timing, and discusses options for making order processing possible for any oscillatory signal generated by rotating equipment. This paper primarily deals with turbine engine vibratory instrumentation and data acquisition. The content discussed herein may also be extended to other types of rotating equipment such as motors, compressors, and turbines. Order processing deals primarily with integral (synchronous) responses, which are forced responses as a function of rotational speed and natural frequencies. Non-synchronous responses, also known as non-integral (NIV) responses, are not considered.The focus of this paper lies in the research of conditioning time domain data sets of various sizes to be transformed to the frequency domain by means of FFTs with standard 2x sizes. This is to be accomplished while varying numbers of samples per revolution for a full range of rotational speeds. Succinctly stated, a comparison is made between standard FFT processing results and simplistic order processing methods. Since improved accuracy is one of the major drivers for developing this capability, the focal points are the acquisition, conditioning, and processing of virtual data sets that are of different sizes than specified FFT sizes. More specifically, the effects of decimation, zero padding, windowing functions, and other types of processing variables are evaluated. This research serves as a precursor for development of comprehensive order processing capabilities for turbine engines at AEDC
High-performance Parallel Solver for Integral Equations of Electromagnetics Based on Galerkin Method
A new parallel solver for the volumetric integral equations (IE) of
electrodynamics is presented. The solver is based on the Galerkin method which
ensures the convergent numerical solution. The main features include: (i) the
memory usage is 8 times lower, compared to analogous IE based algorithms,
without additional restriction on the background media; (ii) accurate and
stable method to compute matrix coefficients corresponding to the IE; (iii)
high degree of parallelism. The solver's computational efficiency is shown on a
problem of magnetotelluric sounding of the high conductivity contrast media. A
good agreement with the results obtained with the second order finite element
method is demonstrated. Due to effective approach to parallelization and
distributed data storage the program exhibits perfect scalability on different
hardware platforms.Comment: The main results of this paper were presented at IAMG 2015 conference
Frieberg, Germany. 28 pages, 11 figure
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