Frequency-Domain Data-Driven Adaptive Iterative Learning Control Approach: With Application to Wafer Stage

The feedforward control is becoming increasingly important in ultra-precision stages. However, the conventional model-based methods cannot achieve expected performance in new-generation stages since it is hard to obtain the accurate plant model due to the complicated stage dynamical properties. To tackle this problem, this article develops a model-free data-driven adaptive iterative learning approach that is designed in the frequency-domain. Explicitly, the proposed method utilizes the frequency-response data to learn and update the output of the feedforward controller online, which has benefits that both the structure and parameters of the plant model are not required. An unbiased estimation method for the frequency response of the closed-loop system is proposed and proved through the theoretical analysis. Comparative experiments on a linear motor confirm the effectiveness and superiority of the proposed method, and show that it has the ability to avoid the performance deterioration caused by the model mismatch with the increasing iterative trials

TeacherLM: Teaching to Fish Rather Than Giving the Fish, Language Modeling Likewise

Large Language Models (LLMs) exhibit impressive reasoning and data augmentation capabilities in various NLP tasks. However, what about small models? In this work, we propose TeacherLM-7.1B, capable of annotating relevant fundamentals, chain of thought, and common mistakes for most NLP samples, which makes annotation more than just an answer, thus allowing other models to learn "why" instead of just "what". The TeacherLM-7.1B model achieved a zero-shot score of 52.3 on MMLU, surpassing most models with over 100B parameters. Even more remarkable is its data augmentation ability. Based on TeacherLM-7.1B, we augmented 58 NLP datasets and taught various student models with different parameters from OPT and BLOOM series in a multi-task setting. The experimental results indicate that the data augmentation provided by TeacherLM has brought significant benefits. We will release the TeacherLM series of models and augmented datasets as open-source.Comment: 5 figures, 15 page

Decentralized Finance (DeFi): A Survey

Decentralized Finance (DeFi) is a new paradigm in the creation, distribution, and utilization of financial services via the integration of blockchain technology. Our research conducts a comprehensive introduction and meticulous classification of various DeFi applications. Beyond that, we thoroughly analyze these risks from both technical and economic perspectives, spanning multiple layers. Lastly, we point out research directions in DeFi, encompassing areas of technological advancements, innovative economics, and privacy optimization

LLMs as Workers in Human-Computational Algorithms? Replicating Crowdsourcing Pipelines with LLMs

LLMs have shown promise in replicating human-like behavior in crowdsourcing tasks that were previously thought to be exclusive to human abilities. However, current efforts focus mainly on simple atomic tasks. We explore whether LLMs can replicate more complex crowdsourcing pipelines. We find that modern LLMs can simulate some of crowdworkers' abilities in these "human computation algorithms," but the level of success is variable and influenced by requesters' understanding of LLM capabilities, the specific skills required for sub-tasks, and the optimal interaction modality for performing these sub-tasks. We reflect on human and LLMs' different sensitivities to instructions, stress the importance of enabling human-facing safeguards for LLMs, and discuss the potential of training humans and LLMs with complementary skill sets. Crucially, we show that replicating crowdsourcing pipelines offers a valuable platform to investigate (1) the relative strengths of LLMs on different tasks (by cross-comparing their performances on sub-tasks) and (2) LLMs' potential in complex tasks, where they can complete part of the tasks while leaving others to humans

Integrative Analysis of Identifying Methylation-Driven Genes Signature Predicts Prognosis in Colorectal Carcinoma

BackgroundAberrant DNA methylation is a critical regulator of gene expression and plays a crucial role in the occurrence, progression, and prognosis of colorectal cancer (CRC). We aimed to identify methylation-driven genes by integrative epigenetic and transcriptomic analysis to predict the prognosis of CRC patients.MethodsMethylation-driven genes were selected for CRC using a MethylMix algorithm and LASSO regression screening strategy, and were further used to construct a prognostic risk-assessment model. The Cancer Genome Atlas (TCGA) database was obtained as the training set for both the screening of methylation-driven genes and the effect of genes signature on CRC prognosis. Then, the prognostic genes signature was validated in three independent expression arrays of CRC data from Gene Expression Omnibus (GEO).ResultsWe identified 143 methylation-driven genes, of which the combination of BATF, PHYHIPL, RBP1, and PNPLA4 expression levels was screened as a better prognostic model with the best area under the curve (AUC) (AUC = 0.876). Compared with patients in the low-risk group, CRC patients in the high-risk group had significantly poorer overall survival in the training set (HR = 2.184, 95% CI: 1.404–3.396, P < 0.001). Similar results were observed in the validation set. Moreover, VanderWeele’s mediation analysis indicated that the effect of methylation on prognosis was mediated by the levels of their expression (HRindirect = 1.473, P = 0.001, Proportion mediated, 69.10%).ConclusionsWe identified a four-gene prognostic signature by integrative analysis and developed a risk-assessment model that is significantly associated with patients’ survival. Methylation-driven genes might be a potential prognostic signature for CRC patients

Étude expérimentale des paramètres du plasma dans la décharge filamentaire à barrière diélectrique de surface nanoseconde

Nanosecond surface dielectric barrier discharges (nSDBDs) at atmospheric pressure have been studied extensively over the last two decades for flow control. About ten years ago, the nSDBD at high pressures was suggested as a source for plasma assisted ignition of combustible mixtures. During last six years, it was found that a severe transformation of a single-shot nanosecond surface streamer discharge is observed at increasing gas pressure and/or voltage.The present thesis is devoted to study of streamer-to-filament transition in a single shot high pressure surface nanosecond barrier discharge in non-reactive gases (nitrogen, oxygen and their mixtures). Literature review presents detailed analysis of streamer discharges and of transitory nanosecond sparks widely studied during last 4 years.The results are presented in three parts. The first part shows the parameters of streamer-to-filament transition in the high pressure nSDBD for different gas mixture composition. For both negative and positive polarities, the transition is a function of pressure and of the voltage amplitude. For positive polarity, the effect of molecular oxygen addition on the transition is extremely strong. The influence of different dielectrics and different electrode materials of the start and development of the filaments is studied experimentally. The micro-images of discharge propagation on three electrode configurations at three different stages – streamer, transition to filament and filamentary regime – are compared.In the second part, plasma properties in the filaments are studied with the help of the energy measurements, optical emission spectroscopy (OES) and Particle Image Velocimetry (PIV). In the streamer and transition regime, the OES spectra mainly contains second positive system of molecular nitrogen while in the filamentary regime continuum (CW) emission and a few atomic lines are observed. The results of measured plasma parameters, namely synchronized in time specific deposited energy, electron temperature and electron density are included. The value of specific deposited energy in the filaments is as high as 6-8 eV/particle; the electron density is in the range of 10 to 18-19 power per cubic centimeter, and the electron temperature stays at the level of 1.5-2 eV in the near afterglow. Plasma at this stage is found to be close to the LTE demonstrating slow (tens of nanoseconds) electron density decay linked to the temperature relaxation. The results of the measurements are compared with the results of numerical modeling explaining the main experimentally observed features. In the model, stepwise ionization and dissociation from electronically excited states of molecular nitrogen leads to fast increase of the electron density, dissociation degree and gas heating at 6 bar on the time scale of parts of nanoseconds.The third part is devoted to detailed study of streamer-to-filament transition in the micro-scale with the spatial resolution 7.6 µm/px. At a given time instant, the surface ionization wave front, composed from the merged streamers, is broken by a few plasma channels, moving with a higher velocity (we call them “protrusions”). Their radii are 10-20 times smaller comparing to a typical streamer radius; they form, within a few nanoseconds, a regular structure of plasma channels around the high voltage electrode. Inside each of these channels, a backward emission of the second positive system of N2 propagates from the “protrusion” head back to the high-voltage electrode. Continuous spectra, atomic lines and high electron density first appear when the backward emission approaches the high-voltage electrode, at the distance about 500 µm from the edge. The calculated results of emission intensity, electron density and electric field are given for studying the influence of oxygen admixtures on the transition.Les décharges de barrière diélectrique de surface nanoseconde (nSDBD) à la pression atmosphérique ont été étudiées de manière approfondie au cours des deux dernières décennies pour le contrôle du débit. Au cours des six dernières années, il a été constaté qu'une transformation sévère d'une décharge de flûte de surface nanoseconde à un seul coup est observée à une pression et / ou une tension de gaz croissantes.La présente thèse est consacrée à l'étude de la transition streamer-filament dans une décharge de barrière nanoseconde de surface haute pression à un seul coup dans des gaz non réactifs (azote, oxygène et leurs mélanges). La revue de la littérature présente une analyse détaillée des décharges de banderoles et des étincelles transitoires de nanosecondes largement étudiées au cours des 4 dernières années.Les résultats sont présentés en trois parties. La première partie montre les paramètres de la transition streamer-filament dans le nSDBD haute pression pour différentes compositions de mélange gazeux. Pour les polarités tant négatives que positives, la transition est fonction de la pression et de l'amplitude de la tension. Pour une polarité positive, l'effet de l'addition d'oxygène moléculaire sur la transition est extrêmement fort. L'influence de différents diélectriques et de différents matériaux d'électrodes sur le début et le développement des filaments est étudiée expérimentalement. Les micro-images de propagation de décharge sur trois configurations d'électrodes à trois étapes différentes - flûte, transition vers filament et régime filamentaire - sont comparées.Dans la deuxième partie, les propriétés du plasma dans les filaments sont étudiées à l'aide des mesures d'énergie, de la spectroscopie d'émission optique (OES) et de la vélocimétrie par image de particules (PIV). Dans le régime de flûte et de transition, les spectres OES contiennent principalement un deuxième système positif d'azote moléculaire tandis que dans le continuum du régime filamentaire (CW) l'émission et quelques raies atomiques sont observées. Les résultats des paramètres de plasma mesurés, à savoir synchronisés en énergie déposée, température électronique et densité électronique, sont inclus. La valeur de l'énergie spécifique déposée dans les filaments est aussi élevée que 6-8 eV / particule; la densité électronique est dans la gamme de 10 à 18-19 puissance par centimètre cube, et la température électronique reste au niveau de 1,5-2 eV dans la quasi-rémanence. Le plasma à ce stade se révèle être proche du LTE, ce qui démontre une décroissance de densité électronique lente (dizaines de nanosecondes) liée à la relaxation de température. Les résultats des mesures sont comparés aux résultats de la modélisation numérique expliquant les principales caractéristiques observées expérimentalement. Dans le modèle, l'ionisation et la dissociation par étapes des états excités électroniquement de l'azote moléculaire entraînent une augmentation rapide de la densité électronique, du degré de dissociation et du chauffage du gaz à 6 bar sur l'échelle de temps de parties de nanosecondes.La troisième partie est consacrée à l'étude détaillée de la transition streamer-filament à la micro-échelle avec une résolution spatiale de 7,6 µm/px. A l'intérieur de chacun canaux, une émission vers l'arrière du deuxième système positif de N2 se propage de la tête «saillie» vers l'électrode haute tension. Des spectres continus, des raies atomiques et une densité électronique élevée apparaissent pour la première fois lorsque l'émission vers l'arrière s'approche de l'électrode haute tension, à environ 500 µm du bord. Les résultats calculés de l'intensité d'émission, de la densité électronique et du champ électrique sont donnés pour étudier l'influence des adjuvants d'oxygène sur la transition

High-fat diet-induced obesity accelerates the progression of spontaneous osteoarthritis in Senescence-Accelerated Mouse Prone 8 (SAMP8)

博士(医学)Doctor of Philosophy in Medical Science広島大学Hiroshima Universit

Time-resolved electron temperature OES measurement in filamentary discharge

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