In this work a multi-frame interferometric system based in digital image processing and digital interferometry is presented. Here, an experimental optical setup which integrates the virtues of the digital interferomet...
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ISBN:
(纸本)9781509011483
In this work a multi-frame interferometric system based in digital image processing and digital interferometry is presented. Here, an experimental optical setup which integrates the virtues of the digital interferometry technique and the capacity to capture two interferograms, to two different times, in a single digital recording system is implemented. The digital reconstruction of the interferograms required the capture of three interferometric patterns of very thin parallel fringes (15-20 lines/mm), one of them with information of the phase object and the other two are interferometric patterns of reference. One of the referential pattern is captured in the same condition as the one with plasma and the other one slightly changing the frequency of the pattern fringes. The interferogram associated with each instant of time is separated by means of spatial filtering techniques. Thus, the technique allows obtain digital interferograms in fringes of infinite and finite width in two different times. The interferometric system was tested in a laser-induced spark plasma in air.
The design of high-performance stream-processing systems is a fast growing domain, driven by markets such like high-end TV, gaming, 3D animation and medical imaging. It is also a surprisingly demanding task, with resp...
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ISBN:
(纸本)9781595930279
The design of high-performance stream-processing systems is a fast growing domain, driven by markets such like high-end TV, gaming, 3D animation and medical imaging. It is also a surprisingly demanding task, with respect to the algorithmic and conceptual simplicity of streaming applications. It needs the close cooperation between numerical analysts, parallel programming experts, real-time control experts and computer architects, and incurs a very high level of quality insurance and *** search for improved productivity, we propose a programming model and language dedicated to high-performance stream processing. This language builds on the synchronous programming model and on domain knowledge -- the periodic evolution of streams -- to allow correct-by-construction properties to be proven by the compiler. These properties include resource requirements and delays between input and output streams. Automating this task avoids tedious and error-prone engineering, due to the combinatorics of the composition of filters with multiple data rates and formats. Correctness of the implementation is also difficult to assess with traditional (asynchronous, simulation-based) approaches. This language is thus provided with a relaxed notion of synchronous composition, called n-synchrony: two processes are n-synchronous if they can communicate in the ordinary (0-)synchronous model with a FIFO buffer of size ***, we extend a core synchronous data-flow language with a notion of periodic clocks, and design a relaxed clock calculus (a type system for clocks) to allow non strictly synchronous processes to be composed or correlated. This relaxation is associated with two sub-typing rules in the clock calculus. Delay, buffer insertion and control code for these buffers are automatically inferred from the clock types through a systematic transformation into a standard synchronous program. We formally define the semantics of the language and prove the soundness and complete
This work reports the spectroscopic performance of the latest release of TERA (Throughput Enhanced Readout ASIC), a multichannel analog pulse processor (APP) ASIC suitable for detectors in ultra-high rate X-ray detect...
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ISBN:
(数字)9781728141640
ISBN:
(纸本)9781728141657
This work reports the spectroscopic performance of the latest release of TERA (Throughput Enhanced Readout ASIC), a multichannel analog pulse processor (APP) ASIC suitable for detectors in ultra-high rate X-ray detection applications (>1Mcps/channel). The chip has been developed to process signals coming from Silicon Drift Detectors (SDDs) coupled with resettype Charge Sensitive Amplifiers (CSA). The demonstrator chip is composed of 4 parallel readout channels, each channel is composed by 7 th -order semi-Gaussian shaping-amplifier with adjustable shaping times and dynamic range, followed by a peak stretcher and an analog memory. Each pair of channels can be optionally digitized by 12-bit on-chip ADC, providing the maximum sampling frequency up to 2.5MHz. TERA architecture enables to achieve simultaneously high throughput and satisfactory energy resolution. In 55 Fe spectroscopy measurements using SDD collimated to 4mm diameter, at the shortest pulse width of 200ns, FWHM Mn-Ka line of 171.5eV and 205.1eV were obtained at input rate 10kcps and 1.61Mcps, respectively. At 1.61Mcps input rate, 1.09Mcps throughput was achieved. High-rate performances are, to our knowledge, the best ones for a Spectroscopy analog ASIC and are close to the ones achievable with standard DPPs. Therefore, TERA can represent an attractive detector pulse processing solution for high-density multichannel detection systems.
The increasing demand of on-board real-time processing represents one of the critical issues in forthcoming scientific and commercial European space missions. Faster and faster signal and image processing algorithms a...
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Three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical conductivity mapping of potential offshore oil and gas reservoirs. The imaging technology employs controlled source ele...
Three-dimensional (3D) geophysical imaging is now receiving considerable attention for electrical conductivity mapping of potential offshore oil and gas reservoirs. The imaging technology employs controlled source electromagnetic (CSEM) and magnetotelluric (MT) fields and treats geological media exhibiting transverse anisotropy. Moreover when combined with established seismic methods, direct imaging of reservoir fluids is possible. Because of the size of the 3D conductivity imaging problem, strategies are required exploiting computational parallelism and optimal meshing. The algorithm thus developed has been shown to scale to tens of thousands of processors. In one imaging experiment, 32,768 tasks/processors on the IBM Watson Research Blue Gene/L supercomputer were successfully utilized. Over a 24 hour period we were able to image a large scale field data set that previously required over four months of processing time on distributed clusters based on Intel or AMD processors utilizing 1024 tasks on an InfiniBand fabric. Electrical conductivity imaging using massively parallel computational resources produces results that cannot be obtained otherwise and are consistent with timeframes required for practical exploration problems.
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