The design of scalar AES Instruction Set Extensions for RISC-V

IACR Transactions on Cryptographic Hardware and Embedded Systems ◽

10.46586/tches.v2021.i1.109-136 ◽

2020 ◽

pp. 109-136

Author(s):

Ben Marshall ◽

G. Richard Newell ◽

Dan Page ◽

Markku-Juhani O. Saarinen ◽

Claire Wolf

Keyword(s):

State Of The Art ◽

The State ◽

Instruction Set ◽

Hardware Cost ◽

Essential Requirement ◽

Performance Improvements ◽

Bit Manipulation ◽

Computing Platforms ◽

Instruction Set Extensions ◽

Work Supports

Secure, efficient execution of AES is an essential requirement on most computing platforms. Dedicated Instruction Set Extensions (ISEs) are often included for this purpose. RISC-V is a (relatively) new ISA that lacks such a standardized ISE. We survey the state-of-the-art industrial and academic ISEs for AES, implement and evaluate five different ISEs, one of which is novel. We recommend separate ISEs for 32 and 64-bit base architectures, with measured performance improvements for an AES-128 block encryption of 4x and 10x with a hardware cost of 1.1K and 8.2K gates respectively, when compared to a software-only implementation based on use of T-tables. We also explore how the proposed standard bit-manipulation extension to RISC-V can be harnessed for efficient implementation of AES-GCM. Our work supports the ongoing RISC-V cryptography extension standardisation process.

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Complex Deep Neural Networks from Large Scale Virtual IMU Data for Effective Human Activity Recognition Using Wearables

Sensors ◽

10.3390/s21248337 ◽

2021 ◽

Vol 21 (24) ◽

pp. 8337

Author(s):

Hyeokhyen Kwon ◽

Gregory D. Abowd ◽

Thomas Plötz

Keyword(s):

Activity Recognition ◽

Human Activity ◽

Large Scale ◽

State Of The Art ◽

Human Activity Recognition ◽

The State ◽

Model Parameters ◽

Data Systems ◽

Performance Improvements ◽

Measurement Units

Supervised training of human activity recognition (HAR) systems based on body-worn inertial measurement units (IMUs) is often constrained by the typically rather small amounts of labeled sample data. Systems like IMUTube have been introduced that employ cross-modality transfer approaches to convert videos of activities of interest into virtual IMU data. We demonstrate for the first time how such large-scale virtual IMU datasets can be used to train HAR systems that are substantially more complex than the state-of-the-art. Complexity is thereby represented by the number of model parameters that can be trained robustly. Our models contain components that are dedicated to capture the essentials of IMU data as they are of relevance for activity recognition, which increased the number of trainable parameters by a factor of 1100 compared to state-of-the-art model architectures. We evaluate the new model architecture on the challenging task of analyzing free-weight gym exercises, specifically on classifying 13 dumbbell execises. We have collected around 41 h of virtual IMU data using IMUTube from exercise videos available from YouTube. The proposed model is trained with the large amount of virtual IMU data and calibrated with a mere 36 min of real IMU data. The trained model was evaluated on a real IMU dataset and we demonstrate the substantial performance improvements of 20% absolute F1 score compared to the state-of-the-art convolutional models in HAR.

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Recent Trends in Word Sense Disambiguation: A Survey

Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence ◽

10.24963/ijcai.2021/593 ◽

2021 ◽

Author(s):

Michele Bevilacqua ◽

Tommaso Pasini ◽

Alessandro Raganato ◽

Roberto Navigli

Keyword(s):

Glass Ceiling ◽

State Of The Art ◽

Word Sense Disambiguation ◽

Representation Learning ◽

The State ◽

Word Sense ◽

Performance Improvements ◽

Sense Disambiguation ◽

The Future ◽

Recent Trends

Word Sense Disambiguation (WSD) aims at making explicit the semantics of a word in context by identifying the most suitable meaning from a predefined sense inventory. Recent breakthroughs in representation learning have fueled intensive WSD research, resulting in considerable performance improvements, breaching the 80% glass ceiling set by the inter-annotator agreement. In this survey, we provide an extensive overview of current advances in WSD, describing the state of the art in terms of i) resources for the task, i.e., sense inventories and reference datasets for training and testing, as well as ii) automatic disambiguation approaches, detailing their peculiarities, strengths and weaknesses. Finally, we highlight the current limitations of the task itself, but also point out recent trends that could help expand the scope and applicability of WSD, setting up new promising directions for the future.

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Full Scale Measurements on a Hydrofoil International Moth

10.5957/csys-2009-013 ◽

2009 ◽

Author(s):

Bill Beaver ◽

John Zseleczky

Keyword(s):

State Of The Art ◽

Full Scale ◽

The State ◽

Hydrodynamic Drag ◽

Aerodynamic Forces ◽

Side Force ◽

Performance Improvements ◽

Lift And Drag

The International Moth class has experienced a resurgence of interest and publicity associated with the adoption of hydrofoils and the performance improvements these foil have brought. This paper documents a series of full scale tow tests intended to characterize some of the major parameters impacting the performance of a foiling Moth. Specifically: - the lift and drag was measured for of various home built and commercially available T-foil configurations, - the hydrodynamic drag of a hull was measured at various displacements, and - the aerodynamic forces (side force and drag) were measured for a hull and racks. It is hoped that this data will be useful for future designers to further push the state of the art.

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Practical Picture Processing

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100051700 ◽

1974 ◽

Vol 32 ◽

pp. 338-339

Author(s):

T. A. Welton

Keyword(s):

Radiation Damage ◽

Coherence Length ◽

Spatial Information ◽

State Of The Art ◽

Coherent Radiation ◽

The State ◽

Energy Spread ◽

Electron Micrograph ◽

Picture Processing ◽

Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

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