Catalogue Search | MBRL
Are you sure you want to remove the book from the shelf?
{{itemTitle}}
241,452
result(s) for
"Arrays"
Sort by:
Awkward to RDataFrame and back
Awkward Arrays [1] and RDataFrame [2] provide two very different ways of performing calculations at scale. By adding the ability to zero-copy convert between them, users get the best of both. It gives users a better flexibility in mixing different packages and languages in their analysis. In Awkward Array version 2, the ak.to rdataframe function presents a view of an Awkward Array as an RDataFrame source. This view is generated on demand and the data are not copied. The column readers are generated based on the run-time type of the views. The readers are passed to a generated source derived from ROOT::RDF::RDataSource. The ak.from rdataframe function converts the selected columns as native Awkward Arrays. The details of the implementation exploiting JIT techniques are discussed. The examples of analysis of data stored in Awkward Arrays via a high-level interface of an RDataFrame are presented. A few examples of the column definition, applying user-defined filters written in C++, and plotting or extracting the columnar data as Awkward Arrays are shown. Current limitations and future plans are discussed.
Journal Article
Low Discrepancy Sparse Phased Array Antennas
Sparse arrays have grating lobes in the far field pattern due to the large spacing of elements residing in a rectangular or triangular grid. Random element spacing removes the grating lobes but produces large variations in element density across the aperture. In fact, some areas are so dense that the elements overlap. This paper introduces a low discrepancy sequence (LDS) for generating the element locations in sparse planar arrays without grating lobes. This nonrandom alternative finds an element layout that reduces the grating lobes while keeping the elements far enough apart for practical construction. Our studies consider uniform sparse LDS arrays with 86% less elements than a fully populated array, and numerical results are presented that show these sampling techniques are capable of completely removing the grating lobes of sparse arrays. We present the mathematical formulation for implementing an LDS generated element lattice for sparse planar arrays, and present numerical results on their performance. Multiple array configurations are studied, and we show that these LDS techniques are not impacted by the type/shape of the planar array. Moreover, in comparison between the LDS techniques, we show that the Poisson disk sampling technique outperforms all other approaches and is the recommended LDS technique for sparse arrays.
Journal Article
Programming FPGAs : getting started with Verilog
\"This fun guide shows how to get started with FPGA technology using the popular Mojo, Papilio One, and Elbert 2 boards. Written by electronics guru Simon Monk, Programming FPGAs: Getting Started with Verilog features clear explanations, easy-to-follow examples, and downloadable sample programs. You'll get start-to-finish assembly and programming instructions for numerous projects, including an LED decoder, a timer, a tone generator - even a memory-mapped video display! The book serves both as a hobbyists' guide and as an introduction for professional developers\"--Publisher's description.
Book
Sensor Arrays: A Comprehensive Systematic Review
Sensor arrays are arrangements of sensors that follow a certain pattern, usually in a row–column distribution. This study presents a systematic review on sensor arrays. For this purpose, several systematic searches of recent studies covering a period of 10 years were performed. As a result of these searches, 361 papers have been analyzed in detail. The most relevant aspects for sensor array design have been studied. In relation to sensing technologies, different categories were identified: resistive/piezoresistive, capacitive, inductive, diode-based, transistor-based, triboelectric, fiber optic, Hall effect-based, piezoelectric, and bioimpedance-based. Other aspects of sensor array design have also been analyzed: applications, validation experiments, software used for sensor array data analysis, sensor array characteristics, and performance metrics. For each aspect, the studies were classified into different subcategories. As a result of this analysis, different emerging technologies and future research challenges in sensor arrays were identified.
Journal Article
Study on ultrasonic phased array detection of butt angle weld
The special structure of the mounted angle weld increases the difficulty of conventional ultrasonic detection, and the detection process is complicated. In this paper, the simulated test blocks including unwelded, unfused, and air holes are designed for the defect types easy to occur in the mounted angle welds, using the Israeli ISONIC2009 ultrasonic phased array detector. The results show that the test process of the method is proven.
Journal Article
Learning FPGAs : digital design for beginners with Mojo and Lucid HDL
\"Learn how to design digital circuits with FPGAs (field-programmable gate arrays), the devices that reconfigure themselves to become the very hardware circuits you set out to program. With this practical guide, author Justin Rajewski shows you hands-on how to create FPGA projects, whether you're a programmer, engineer, product designer, or maker. You'll quickly go from the basics to designing your own processor. Designing digital circuits used to be a long and costly endeavor that only big companies could pursue. FPGAs make the process much easier, and now they're affordable enough even for hobbyists. If you're familiar with electricity and basic electrical components, this book starts simply and progresses through increasingly complex projects\"--Publisher's description.
Book
Application of series resonant converters to reduce ripple transmission to LED arrays in offline drivers
This article proposed a novel approach to reduce low-frequency ripple in light-emitting diode (LED) arrays that are supplied from the AC grid. The proposal employs a series resonant DC--DC converter connected to the output of the power factor correction (PFC) stage so that the low-frequency ripple transmitted from the PFC stage to the LEDs can be minimised. This solution achieves two goals: reduction of the bulk capacitance used at the output of the PFC stage so that long-life film capacitors can be employed, and increasing the efficiency of the LED driver owing to the low switching losses of the resonant converter. Experimental results are provided to validate this proposal.
Journal Article