High-performance holographic technologies for fluid-dynamics experiments

Modern technologies offer new opportunities for experimentalists in a variety of research areas of fluid dynamics. Improvements are now possible in the state-of-the-art in precision, dynamic range, reproducibility, motion-control accuracy, data-acquisition rate and information capacity. These improvements are required for understanding complex turbulent flows under realistic conditions, and for allowing unambiguous comparisons to be made with new theoretical approaches and large-scale numerical simulations. One of the new technologies is high-performance digital holography. State-of-the-art motion control, electronics and optical imaging allow for the realization of turbulent flows with very high Reynolds number (more than 10 7 ) on a relatively small laboratory scale, and quantification of their properties with high space–time resolutions and bandwidth. In-line digital holographic technology can provide complete three-dimensional mapping of the flow velocity and density fields at high data rates (over 1000 frames per second) over a relatively large spatial area with high spatial (1–10 μm) and temporal (better than a few nanoseconds) resolution, and can give accurate quantitative description of the fluid flows, including those of multi-phase and unsteady conditions. This technology can be applied in a variety of problems to study fundamental properties of flow–particle interactions, rotating flows, non-canonical boundary layers and Rayleigh–Taylor mixing. Some of these examples are discussed briefly.

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Evaluation of recent advances in recommender systems on Arabic content

Journal Of Big Data ◽

10.1186/s40537-021-00420-2 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Mehdi Srifi ◽

Ahmed Oussous ◽

Ayoub Ait Lahcen ◽

Salma Mouline

Keyword(s):

Recommender Systems ◽

High Performance ◽

Large Scale ◽

State Of The Art ◽

Experimental Results ◽

Recent Advances ◽

Research Gap ◽

Text Preprocessing

AbstractVarious recommender systems (RSs) have been developed over recent years, and many of them have concentrated on English content. Thus, the majority of RSs from the literature were compared on English content. However, the research investigations about RSs when using contents in other languages such as Arabic are minimal. The researchers still neglect the field of Arabic RSs. Therefore, we aim through this study to fill this research gap by leveraging the benefit of recent advances in the English RSs field. Our main goal is to investigate recent RSs in an Arabic context. For that, we firstly selected five state-of-the-art RSs devoted originally to English content, and then we empirically evaluated their performance on Arabic content. As a result of this work, we first build four publicly available large-scale Arabic datasets for recommendation purposes. Second, various text preprocessing techniques have been provided for preparing the constructed datasets. Third, our investigation derived well-argued conclusions about the usage of modern RSs in the Arabic context. The experimental results proved that these systems ensure high performance when applied to Arabic content.

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Electrode Materials for High-Performance Sodium-Ion Batteries

Materials ◽

10.3390/ma12121952 ◽

2019 ◽

Vol 12 (12) ◽

pp. 1952 ◽

Cited By ~ 10

Author(s):

Santanu Mukherjee ◽

Shakir Bin Mujib ◽

Davi Soares ◽

Gurpreet Singh

Keyword(s):

High Performance ◽

Large Scale ◽

Electrode Materials ◽

State Of The Art ◽

Electronic Conductivity ◽

Lithium Ion ◽

Cycle Life ◽

Sodium Ion ◽

Sodium Ion Batteries ◽

Grid Storage

Sodium ion batteries (SIBs) are being billed as an economical and environmental alternative to lithium ion batteries (LIBs), especially for medium and large-scale stationery and grid storage. However, SIBs suffer from lower capacities, energy density and cycle life performance. Therefore, in order to be more efficient and feasible, novel high-performance electrodes for SIBs need to be developed and researched. This review aims to provide an exhaustive discussion about the state-of-the-art in novel high-performance anodes and cathodes being currently analyzed, and the variety of advantages they demonstrate in various critically important parameters, such as electronic conductivity, structural stability, cycle life, and reversibility.

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High-Performance Emerging Solid-State Memory Technologies

MRS Bulletin ◽

10.1557/mrs2004.232 ◽

2004 ◽

Vol 29 (11) ◽

pp. 805-813 ◽

Cited By ~ 26

Author(s):

Herb Goronkin ◽

Yang Yang

Keyword(s):

Solid State ◽

Research And Development ◽

High Performance ◽

New Technologies ◽

State Of The Art ◽

Electronic Equipment ◽

Private Industry ◽

Development Stages ◽

The World ◽

And Storage

AbstractThis article introduces the November 2004 issue of MRS Bulletin on the state of the art in solid-state memory and storage technologies.The memory business drives hundreds of billions of dollars in sales of electronic equipment per year. The incentive for continuing on the historical track outlined by Moore's law is huge, and this challenge is driving considerable investment from governments around the world as well as in private industry and universities. The problem is this: recognizing that current approaches to semiconductor-based memory are limited, what new technologies can be introduced to continue or even accelerate the pace of complexity? The articles in this issue highlight several commercially available memories, as well as memory technologies that are still in the research and development stages. What will become apparent to the reader is the huge diversity of approaches to this problem.

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Mingantu Spectral Radioheliograph for Solar and Space Weather Studies

Frontiers in Astronomy and Space Sciences ◽

10.3389/fspas.2021.584043 ◽

2021 ◽

Vol 8 ◽

Author(s):

Yihua Yan ◽

Zhijun Chen ◽

Wei Wang ◽

Fei Liu ◽

Lihong Geng ◽

...

Keyword(s):

Spatial Resolution ◽

Space Weather ◽

Large Scale ◽

New Technologies ◽

Dynamic Range ◽

Signal Transmission ◽

Wide Band ◽

Baseline Length ◽

Frequency Range ◽

Full Disk

The Chinese Spectral Radioheliograph (CSRH) covering 400 MHz-15 GHz frequency range was constructed during 2009–2016 in Mingantu Observing Station, National Astronomical Observatories, Chinese Academy of Sciences at Zhengxiangbaiqi, Inner Mongolia of China. The CSRH is renamed as MingantU SpEctral Radioheliograph (MUSER) after its accomplishment. Currently, MUSER consists of two arrays spreading over three spiral-shaped arms. The maximum baseline length is ∼3 km in both east-west and north-south directions. The MUSER array configuration is optimized to meet the needs of observing the full-disk Sun over ultrawide wavebands with images of high temporal, spatial and spectral resolutions and high dynamic range. The low frequency array, called MUSER-I, covers 400 MHz-2.0 GHz with 40 antennas of 4.5-m-diameter each and the high frequency array, called MUSER-II, covers 2–15 GHz with 60 antennas of 2-m-diameter each. The MUSER-I can obtain full-disk solar radio images in 64 frequency channels with a time cadence of 25 ms and a spatial resolution of 51.6″ to 10.3″ (corresponding to the frequency range 400 MHz to 2 GHz), whereas the MUSER-II can obtain full-disk solar images in 520 channels with a time cadence of 206.25 ms and a spatial resolution of 10.3″ to 1.3 (corresponding to the frequency range 2 to 15 GHz). A dynamic range of 25 dB can be obtained with snapshot images produced with the MUSER. An extension of MUSER in the further lower frequency range covering 30–400 MHz with an array of 224 logarithm-periodic dipole antennas (LPDAs) has been approved and will be completed during the next 4 years. The MUSER, as a dedicated solar instrument, has the following advantages providing simultaneous images over a wide frequency range with a unique high temporal-spatial-spectral resolutions; high-performing ultrawide-band dual-polarization feeds for wide-band signal collection; advanced high data-rate, large-scale digital correlation receiver for multiple-frequency and faster snapshot observations; and applications of new technologies such as using optical fiber to obtain remote antenna and wide-band analog signal transmission. The MUSER thus provides a unique opportunity to measure solar magnetic fields and trace dynamic evolution of energetic electrons in several radio frequencies, which, in turn, will help to have better understandings of the origin of various solar activities and the basic drivers of space weather.

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Exact Coherent States and the Nonlinear Dynamics of Wall-Bounded Turbulent Flows

Annual Review of Fluid Mechanics ◽

10.1146/annurev-fluid-051820-020223 ◽

2021 ◽

Vol 53 (1) ◽

pp. 227-253 ◽

Cited By ~ 1

Author(s):

Michael D. Graham ◽

Daniel Floryan

Keyword(s):

State Space ◽

Turbulent Flows ◽

Coherent Structures ◽

Coherent States ◽

Large Scale ◽

Stokes Equations ◽

Saddle Points ◽

Transport Processes ◽

Hairpin Vortices ◽

Theoretical Approaches

Wall-bounded turbulence exhibits patterns that persist in time and space: coherent structures. These are important for transport processes and form a conceptual framework for important theoretical approaches. Key observed structures include quasi-streamwise and hairpin vortices, as well as the localized spots and puffs of turbulence observed during transition. This review describes recent research on so-called exact coherent states (ECS) in wall-bounded parallel flows at Reynolds numbers Re [Formula: see text] 104; these are nonturbulent, nonlinear solutions to the Navier–Stokes equations that in many cases resemble coherent structures in turbulence. That is, idealized versions of many of these structures exist as distinct, self-sustaining entities. ECS are saddle points in state space and form, at least in part, the state space skeleton of the turbulent dynamics. While most work on ECS focuses on Newtonian flow, some advances have been made on the role of ECS in turbulent drag reduction in polymer solutions. Emerging directions include applications to control and connections to large-scale structures and the attached eddy model.

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WinoGrande

Communications of the ACM ◽

10.1145/3474381 ◽

2021 ◽

Vol 64 (9) ◽

pp. 99-106

Author(s):

Keisuke Sakaguchi ◽

Ronan Le Bras ◽

Chandra Bhagavatula ◽

Yejin Choi

Keyword(s):

High Performance ◽

Large Scale ◽

State Of The Art ◽

Bias Reduction ◽

Language Models ◽

Systematic Bias ◽

Commonsense Reasoning ◽

Word Associations ◽

Lower Accuracy ◽

Key Steps

Commonsense reasoning remains a major challenge in AI, and yet, recent progresses on benchmarks may seem to suggest otherwise. In particular, the recent neural language models have reported above 90% accuracy on the Winograd Schema Challenge (WSC), a commonsense benchmark originally designed to be unsolvable for statistical models that rely simply on word associations. This raises an important question---whether these models have truly acquired robust commonsense capabilities or they rely on spurious biases in the dataset that lead to an overestimation of the true capabilities of machine commonsense. To investigate this question, we introduce WinoGrande, a large-scale dataset of 44k problems, inspired by the original WSC, but adjusted to improve both the scale and the hardness of the dataset. The key steps of the dataset construction consist of (1) large-scale crowdsourcing, followed by (2) systematic bias reduction using a novel AFLITE algorithm that generalizes human-detectable word associations to machine-detectable embedding associations. Our experiments demonstrate that state-of-the-art models achieve considerably lower accuracy (59.4%-79.1%) on WINOGRANDE compared to humans (94%), confirming that the high performance on the original WSC was inflated by spurious biases in the dataset. Furthermore, we report new state-of-the-art results on five related benchmarks with emphasis on their dual implications. On the one hand, they demonstrate the effectiveness of WINOGRANDE when used as a resource for transfer learning. On the other hand, the high performance on all these benchmarks suggests the extent to which spurious biases are prevalent in all such datasets, which motivates further research on algorithmic bias reduction.

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Does 0.1 Micron = MACH 1?

MRS Proceedings ◽

10.1557/proc-380-165 ◽

1995 ◽

Vol 380 ◽

Cited By ~ 1

Author(s):

R. Fabian Pease

Keyword(s):

High Performance ◽

Large Scale ◽

State Of The Art ◽

Commercial Use ◽

Optical Projection ◽

Large Scale Integration ◽

On Chip ◽

Scale Integration ◽

The Cost ◽

The Military

ABSTRACTThe drive to increasingly higher density ultra-large-scale-integration (ULSI) (of electronic circuits) is fuelled primarily by cost; on-chip interconnects are far cheaper than the less dense offchip interconnects. At the same time the escalating cost of an IC factory (‘fab’) is making headlines as it goes through $1B and a large part of this escalation is the cost of high performance lithography tools. The lithographic technology to go below 0.1μm will almost certainly be very different from an extension of today's optical projection and the cost of replacing today's technology will be enormous. A second drawback to higher density is the resistance of narrow interconnects. As a result some people have suggested that this situation is analogous to that of airliner speed which increased over a period of thirty years from about 100 mph to close to 600 mph but has not increased in the last 35 years. Still faster speed was technically possible, and hence was pursued by the military, but is uneconomical for most commercial use. Current technology might take us to 0.1μm which will probably be state of the art 10 years hence so technologies for replacing optical lithography e.g. scanned arrays of proximal probes should be researched now. Other challenges include how to achieve useful interconnect networks employing 50 nm features.

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A Survey of Cloud-Based Design and Engineering Analysis Software Tools

Volume 1A: 36th Computers and Information in Engineering Conference ◽

10.1115/detc2016-59341 ◽

2016 ◽

Author(s):

Dazhong Wu ◽

Janis Terpenny ◽

Dirk Schaefer

Keyword(s):

High Performance ◽

New Technologies ◽

State Of The Art ◽

Software Tools ◽

Digital Design ◽

Engineering Analysis ◽

Analysis Software ◽

Analysis Process ◽

Software Packages ◽

Almost All

In recent years, industrial nations around the globe have invested heavily in new technologies, software, and services to advance digital design and engineering analysis using the digital thread, data analytics, and high performance computing. Many of these initiatives such as Cloud-Based Design and Engineering analysis (CBDEA) fall under the umbrella of what has become known as Industry 4.0 or Industrial Internet. While an increasing number of companies are developing or already offering commercial cloud-based software packages and services for digital design and engineering analysis, little work has been reported on analyzing and documenting the related state-of-the-art as well as identifying potentially critical research gaps to be addressed in advancing this rapidly growing field. The objective of this paper is to present a state-of-the-art review of digital design and engineering analysis software and services that are currently available on the cloud. The main focus of this paper is on assessing the extent to which design and engineering analysis can already be performed based on the software and services accessed through the cloud. In addition, the key capabilities and benefits of these software packages and services are discussed. Based on the assessment of the core features of commercial CBDEA software and service packages, results suggest that almost all phases of a typical design and engineering analysis process can indeed already be conducted through cloud-based software tools and services.

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Text Rewriting Improves Semantic Role Labeling

Journal of Artificial Intelligence Research ◽

10.1613/jair.4431 ◽

2014 ◽

Vol 51 ◽

pp. 133-164 ◽

Cited By ~ 1

Author(s):

K. Woodsend ◽

M. Lapata

Keyword(s):

Gold Standard ◽

High Performance ◽

Large Scale ◽

State Of The Art ◽

The State ◽

Semantic Role ◽

Semantic Role Labeling ◽

Comparable Corpora ◽

Rewrite Rules ◽

Model Training

Large-scale annotated corpora are a prerequisite to developing high-performance NLP systems. Such corpora are expensive to produce, limited in size, often demanding linguistic expertise. In this paper we use text rewriting as a means of increasing the amount of labeled data available for model training. Our method uses automatically extracted rewrite rules from comparable corpora and bitexts to generate multiple versions of sentences annotated with gold standard labels. We apply this idea to semantic role labeling and show that a model trained on rewritten data outperforms the state of the art on the CoNLL-2009 benchmark dataset.

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From numerical prototypes to real models: a progressive study of aerodynamic parameters of nonconventional concrete structures with Computational Fluid Dynamics

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952020000300012 ◽

2020 ◽

Vol 13 (3) ◽

pp. 628-643

Author(s):

C. V. S. SARMENTO ◽

A. O. C. FONTE ◽

L. J. PEDROSO ◽

P. M. V. RIBEIRO

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

High Performance ◽

Large Scale ◽

Computational Models ◽

Computational Cost ◽

Concrete Structures ◽

Navier Stokes ◽

Small Scale ◽

Aerodynamic Parameters

Abstract The practical evaluation of aerodynamic coefficients in unconventional concrete structures requires specific studies, which are small-scale models evaluated in wind tunnels. Sophisticated facilities and special sensors are needed, and the tendency is for modern and slender constructions to arise with specific demands on their interaction with the wind. On the other hand, the advances obtained in modern multi-core processors emerge as an alternative for the construction of sophisticated computational models, where the Navier-Stokes differential equations are solved for fluid flow using numerical methods. Computations of this kind require specialized theoretical knowledge, efficient computer programs, and high-performance computers for large-scale calculations. This paper presents recent results involving two real-world applications in concrete structures, where the aerodynamic parameters were estimated with the aid of computational fluid dynamics. Conventional quad-core computers were applied in simulations with the Finite Volume Method and a progressive methodology is presented, highlighting the main aspects of the simulation and allowing its generalization to other types of problems. The results confirm that the proposed methodology is promising in terms of computational cost, drag coefficient estimation and versatility of simulation parameters. These results also indicate that mid-performance computers can be applied for preliminary studies of aerodynamic parameters in design offices.

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