The microwave-induced thermoacoustic imaging(TAI)technology has both the advantages of high contrast of microwave imaging and high resolution of ultrasound imaging(UI),so it has carried out exploratory application res...
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The microwave-induced thermoacoustic imaging(TAI)technology has both the advantages of high contrast of microwave imaging and high resolution of ultrasound imaging(UI),so it has carried out exploratory application research in various areas,such as the early detection of breast tumors and cerebrovascular ***,the microwave generator used in the traditional TAI technology is huge and expensive,and the temporal resolution is also too low due to the single-element scanning ***,it is difficult to meet the needs of clinical *** this paper,the iterative process and the analysis of related application scenarios from single-element scanning to portable and array-based TAI,such as the miniaturized microwave generator,handheld antenna,multi-channel data acquisition,and UI/TAIdual-modality imaging,are reviewed,and the future trends of this technology are *** review helps researchers in the field of TAI learn the technological development process and future *** also deepens clinicians’understanding of TAI so as to put forward more application requirements.
Beamforming enhances the performance of array-based photoacoustic microscopy (PAM) systems for large-area scan. In this study, we quantify the imaging performance of a large field-of-view optical-resolution photoacous...
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Beamforming enhances the performance of array-based photoacoustic microscopy (PAM) systems for large-area scan. In this study, we quantify the imaging performance of a large field-of-view optical-resolution photoacoustic-microscopy system using an phased-array detector. The system combines a low-cost pulsed-laser diode with a 128-element linear ultrasound probe. Signal-to-noise ratio (SNR) and generalized contrast-to-noise ratio (gCNR) are quantified using the phased-array detector and applying three beamforming strategies: a no-beamforming method equivalent to a single-element flat transducer, a fixed focus beamforming method that mimics a single-element focused transducer, and a dynamic focus beamforming using a delay-and-sum (DAS) algorithm. The imaging capabilities of the system are demonstrated generating high-resolution images of tissue-mimicking phantoms containing sub-millimetre ink tubes and an ex vivo rabbit's ear. The results show that dynamic focus DAS beamforming increases and homogenizes SNR along 1-cm(2) images, reaching values up to 15 dB compared to an unfocused detector and up to 30 dB compared to out-of-focus regions of the fixed focus configuration. Moreover, the obtained values of gCNR using the DAS beamformer indicate an excellent target visibility, both on phantoms and ex vivo. This strategy makes it possible to scan larger surfaces compared to standard configurations using single-element detectors, paving the way for advanced array-based PAM systems.
Climate observations and model simulations are producing vast amounts of array-based spatiotemporal data. Efficient processing of these data is essential for assessing global challenges such as climate change, natural...
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Climate observations and model simulations are producing vast amounts of array-based spatiotemporal data. Efficient processing of these data is essential for assessing global challenges such as climate change, natural disasters, and diseases. This is challenging not only because of the large data volume, but also because of the intrinsic high-dimensional nature of geoscience data. To tackle this challenge, we propose a spatiotemporal indexing approach to efficiently manage and process big climate data with MapReduce in a highly scalable environment. Using this approach, big climate data are directly stored in a Hadoop Distributed File System in its original, native file format. A spatiotemporal index is built to bridge the logical array-based data model and the physical data layout, which enables fast data retrieval when performing spatiotemporal queries. based on the index, a data-partitioning algorithm is applied to enable MapReduce to achieve high data locality, as well as balancing the workload. The proposed indexing approach is evaluated using the National Aeronautics and Space Administration (NASA) Modern-Era Retrospective Analysis for Research and Applications (MERRA) climate reanalysis dataset. The experimental results show that the index can significantly accelerate querying and processing (similar to 10x speedup compared to the baseline test using the same computing cluster), while keeping the index-to-data ratio small (0.0328%). The applicability of the indexing approach is demonstrated by a climate anomaly detection deployed on a NASA Hadoop cluster. This approach is also able to support efficient processing of general array-based spatiotemporal data in various geoscience domains without special configuration on a Hadoop cluster.
Rescue Karyotyping: a Case Series of array-based Comparative Genomic Hybridization Evaluation of Archival Conceptual Tissue. by Kudesia, Rashmi; Li, Marilyn; Smith, Janice; Patel, Ankita; Williams, Zev; published by
Rescue Karyotyping: a Case Series of array-based Comparative Genomic Hybridization Evaluation of Archival Conceptual Tissue. by Kudesia, Rashmi; Li, Marilyn; Smith, Janice; Patel, Ankita; Williams, Zev; published by
Numerical simulation coupled with experimental method was carried out to study the flow and heat transfer characteristics in rectangular channel with staggered array-based dimples. The effect of different dimple depth...
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Numerical simulation coupled with experimental method was carried out to study the flow and heat transfer characteristics in rectangular channel with staggered array-based dimples. The effect of different dimple depths and Reynolds number were investigated using the shear stress transport turbulent model coupled with gamma-theta transition model. The results indicated that heat transfer and flow resistance of the dimpled surface increases with the increase of dimple depth. Moreover, the thermal performance is sensitive to the flow transition. Heat transfer in each single dimple region increases monotonously in the streamwise direction with Reynolds number increasing. Heat transfer characteristics almost remain the same when the flow is under fully laminar or turbulent but increases greatly when the flow is transited from laminar condition to turbulent condition. Besides, the variations of friction coefficients and thermal performance coefficients are quite similar to those of heat transfer enhancement coefficients, which firstly increases then decreases with the increase of Reynolds number. By comparing the experimental and numerical results, it is found that staggered array-based dimples with delta/D = 0.2 was the most effective structure from the aspect of thermal performance.
The impact of Electromigration (EM) on the Bit-Error-Rate (BER) of signal interconnect paths was experimentally examined. An array-based test-vehicle for tracking Bit-Error-Rate (BER) degradation of signal interconnec...
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The impact of Electromigration (EM) on the Bit-Error-Rate (BER) of signal interconnect paths was experimentally examined. An array-based test-vehicle for tracking Bit-Error-Rate (BER) degradation of signal interconnects subject to Direct-Current (DC) EM stress was implemented in a 16nm FinFET process. A unit interconnect path comprises five identical interconnect stages where each wire is driven by inverter based buffers. Accelerated EM stress testing is achieved entirely on-chip using metal heaters located directly above the devices-under-test (DUTs) and separate stress circuits driving both ends of the wire. The proposed test structure features a ring-based Voltage-Controlled-Oscillator (VCO), a bit-pattern generator and local BER sampling monitors which enable bitwise tracking of '0' and '1' errors separately, further simplifying the overall test-setup and allowing for high precision characterization of EM induced resistance shifts using only digital circuits. Measurement data collected from the 16nm prototype reveals unique insights into EM induced signal path degradation that was not available prior to this work. Our experimental studies suggest that monitoring the BER of an interconnect path could be used as a new metric for capturing EM induced resistance shifts in a real system, in lieu of the conventional approach which focuses on monitoring standalone wire resistances. Supplemental simulations showcasing the projected degradation in the interconnect path operating frequency as a function of stress time constructed from resistance traces sampled from identical wires implemented in the same process reaffirm the measurement trends.
The high speed and in-pixel processing of image data in smart vision sensors is an important solution for real time machine vision tasks. Diverse architectures have been presented for arraybased kernel convolution pr...
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The high speed and in-pixel processing of image data in smart vision sensors is an important solution for real time machine vision tasks. Diverse architectures have been presented for arraybased kernel convolution processing, many of which use analog processing elements to save space. In this paper a digital arraybased bit serial architecture is presented to perform certain image filtering tasks in the digital domain and hence gain higher accuracies than the analog methods. The presented method benefits from more diverse convolution options such as arbitrary size kernel windows, compared with the digital pulse based approaches. The proposed digital cell structure is compact enough to fit inside an image sensor pixel. When incorporated in a vision chip, resolutions of up to 12 bit accuracy can be obtained in kernel convolution functions with 35 x 28 mu m(2) layout area usage per pixel in a 90 nm technology. Still, higher accuracies can be obtained with larger pixels. The power consumption of the approach is approximately 10 nW/pixel at a frame rate of 1 kfps. (C) 2013 Elsevier B.V. All rights reserved.
Transcriptional regulation is a key step to control the level of mRNA formed. Recent view of transcriptional regulation has evolved from a one-dimensional mode, i.e. RNA Polymerase II assembles with general transcript...
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Transcriptional regulation is a key step to control the level of mRNA formed. Recent view of transcriptional regulation has evolved from a one-dimensional mode, i.e. RNA Polymerase II assembles with general transcription factors, and cis-regulatory elements (CREs) interact with transcription factors, to a much complex multiple-dimensional mode, involving combinatorial interactions between transcription factors and regulatory sequences, chromatin structure, histone modifications, DNA methylation. High throughput experimental technologies, such as array-based ChIP-chip and sequencing-based ChIP-seq, have been developed to survey in vivo transcription factor binding sites and histone modifications. Despite many efforts have been made to analyze and interpret the data, challenges remain in many aspects of both experimental protocols and computational analyses. For example, how to determine the optimized number of PCR cycles? How to normalize multiple datasets from multiple experiments? How to utilize the large number of unmapped and multiple mapped tags in ChIP-seq experiment? This review focuses on issues emerged in high throughput data processing and discusses advantages and disadvantages of various strategies.
Nowadays, there are a number of algorithms that have been proposed in frequent itemsets mining (FIM). Data projection is one of the key features in FIM that affects the overall performance. The aim is to speed up the ...
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ISBN:
(纸本)9789812879363;9789812879356
Nowadays, there are a number of algorithms that have been proposed in frequent itemsets mining (FIM). Data projection is one of the key features in FIM that affects the overall performance. The aim is to speed up the searching process by rearranging the items in a more compact form and to fit all the items in the data set in main memory efficiently without losing any information. The data refer to how the data set is stored in the main memory before the mining process begin. This paper explores the effects of data projection on frequent itemset mining from three different data projection types which are FP-Tree (tree-based), H-Struct (array-based) and FP-Graph (graph-based). The time construction and memory consumption are used to evaluate the parse and the dense of the data set. The result showed the construction of H-Struct is the fastest, but it consumes more time to mine frequent itemsets compared with FP-Tree and FP-Graph.
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