217 research outputs found
Effect of \u3cem\u3eLactobacillus plantarum\u3c/em\u3e on Fermentation Quality of Alfalfa Silages Mixed with Different Proportions of Jujube Powder
Hebei province is one of the main production areas of alfalfa (Medicago sativa) in China. While alfalfa is used to make silages, it is necessary to improve the fermentation quality of alfalfa silage. Jujube powder which contains a high content of sugar, might be a good material to ensile mixed with alfalfa. On the other hand, the effect of lactic acid bacteria (LAB) has been documented and has been used as an additive to achieve good preservation of silage.
The objective of this study was a) to screen different ratios of jujube powder in the mixed silage of alfalfa and jujube powder and b) verify the effect of Lactobacillus plantarum strain on fermentation quality of the alfalfa silages
Multilingual Lexical Simplification via Paraphrase Generation
Lexical simplification (LS) methods based on pretrained language models have
made remarkable progress, generating potential substitutes for a complex word
through analysis of its contextual surroundings. However, these methods require
separate pretrained models for different languages and disregard the
preservation of sentence meaning. In this paper, we propose a novel
multilingual LS method via paraphrase generation, as paraphrases provide
diversity in word selection while preserving the sentence's meaning. We regard
paraphrasing as a zero-shot translation task within multilingual neural machine
translation that supports hundreds of languages. After feeding the input
sentence into the encoder of paraphrase modeling, we generate the substitutes
based on a novel decoding strategy that concentrates solely on the lexical
variations of the complex word. Experimental results demonstrate that our
approach surpasses BERT-based methods and zero-shot GPT3-based method
significantly on English, Spanish, and Portuguese
Plum: Prompt Learning using Metaheuristic
Since the emergence of large language models, prompt learning has become a
popular method for optimizing and customizing these models. Special prompts,
such as Chain-of-Thought, have even revealed previously unknown reasoning
capabilities within these models. However, the progress of discovering
effective prompts has been slow, driving a desire for general prompt
optimization methods. Unfortunately, few existing prompt learning methods
satisfy the criteria of being truly "general", i.e., automatic, discrete,
black-box, gradient-free, and interpretable all at once. In this paper, we
introduce metaheuristics, a branch of discrete non-convex optimization methods
with over 100 options, as a promising approach to prompt learning. Within our
paradigm, we test six typical methods: hill climbing, simulated annealing,
genetic algorithms with/without crossover, tabu search, and harmony search,
demonstrating their effectiveness in black-box prompt learning and
Chain-of-Thought prompt tuning. Furthermore, we show that these methods can be
used to discover more human-understandable prompts that were previously
unknown, opening the door to a cornucopia of possibilities in prompt
optimization. We release all the codes in
\url{https://github.com/research4pan/Plum}
A three-DOF ultrasonic motor using four piezoelectric ceramic plates in bonded-type structure
A three-DOF ultrasonic motor is presented in this paper. The proposed motor consists of four piezoelectric ceramic plates and a mental base with a flange that can fix the motor on a rack. The proposed motor takes advantage of a longitudinal mode and two bending modes, different hybrids of which can realize three-DOF actuation. Because of symmetric structure of the proposed motor, the resonance frequencies of the two bending modes are identical. And the resonance frequency of the longitudinal mode was tuned closed to the ones of the bending modes by adjusting the structural parameters in modal analysis. Then trajectories of nodes on the driving foot were obtained by the transient analysis to verify the feasibility of driving principle. Experiments including vibration shape test and output characteristic test were executed. The starting voltages of the rotation along horizontal axes are about 10 Vp-p. Under driving voltages of 200 Vp-p, the output velocities of three DOF can reach 280 rpm, 277 rpm and 327 rpm, respectively. The results of the experiments indicate that the proposed motor is characterized by low starting voltages and high output velocities
Time-memory Trade-offs for Saber+ on Memory-constrained RISC-V
Saber is a module-lattice-based key encapsulation scheme that has been selected as a finalist in the NIST Post-Quantum Cryptography Standardization Project. As Saber computes on considerably large matrices and vectors of polynomials, its efficient implementation on memory-constrained IoT devices is very challenging. In this paper, we present an implementation of Saber with a minor tweak to the original Saber protocol for achieving reduced memory consumption and better performance. We call this tweaked implementation `Saber+\u27, and the difference compared to Saber is that we use different generation methods of public matrix and secret vector for memory optimization. Our highly optimized software implementation of Saber+ on a memory-constrained RISC-V platform achieves 48\% performance improvement compared with the best state-of-the-art memory-optimized implementation of original Saber.
Specifically, we present various memory and performance optimizations for Saber+ on a memory-constrained RISC-V microcontroller, with merely 16KB of memory available. We utilize the Number Theoretic Transform (NTT) to speed up the polynomial multiplication in Saber+. For optimizing cycle counts and memory consumption during NTT, we carefully compare the efficiency of the complete and incomplete-NTTs, with platform-specific optimization. We implement 4-layers merging in the complete-NTT and 3-layers merging in the 6-layer incomplete-NTT. An improved on-the-fly generation strategy of the public matrix and secret vector in Saber+ results in low memory footprint. Furthermore, by combining different optimization strategies, various time-memory trade-offs are explored. Our software implementation for Saber+ on selected RISC-V core takes just 3,809K, 3,594K, and 3,193K clock cycles for key generation, encapsulation, and decapsulation, respectively, while consuming only 4.8KB of stack at most
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