Miracle-dz/UniFAR-FTUs huggingface dataset:
MyWAL: performance optimization by removing redundant input/output stack in key-value store

Based on a log-structured merge (LSM) tree, the key-value (KV) storage system can provide high reading performance and optimize random writing performance. It is widely used in modern data storage systems like e-commerce, online analytics, and real-time communication. An LSM tree stores new KV data in the memory and flushes to disk in batches. To prevent data loss in memory if there is an unexpected crash, RocksDB appends updating data in the write-ahead log (WAL) before updating the memory. However, synchronous WAL significantly reduces writing performance. In this paper, we present a new WAL mechanism named MyWAL. It directly manages raw devices (or partitions) instead of saving data on a traditional file system. These can avoid useless metadata updating and write data sequentially on disks. Experimental results show that MyWAL can significantly improve the data writing performance of RocksDB compared to the traditional WAL for small KV data on solid-state disks (SSDs), as much as five to eight times faster. On non-volatile memory express soild-state drives (NVMe SSDs) and non-volatile memory (NVM), MyWAL can improve data writing performance by 10%–30%. Furthermore, the results of YCSB (Yahoo! Cloud Serving Benchmark) show that the latency decreased by 50% compared with SpanDB.
Quelques invariants topologiques en géométrie symplectique

This work studies local and global invariants in symplectic geometry. We give a général frame for the Calabi invariant, a Riemannian interprétation of the Maslov class, and we define a canonical connexion on a manifold endowed with two transverse Lagrangian foliations. Finally, we study the manifolds endowed with a « structure canonique » (in the sensé of A. Lichnerowicz). Les variétés symplectiques sont le cadre naturel de la mécanique analytique classique. Nous nous intéressons ici aux invariants topologiques liés à une telle structure, introduits pour étudier différents problèmes de mécanique. Ainsi, dans la première partie, nous généralisons l’invariant de Calabi, pour aborder l’étude des déformations des applications symplectiques. Annales de l’Institut Henri Poincaré-Section A-Vol. XXXVIII, 0020-2339/1983/349/S 5,00/ (0 Gauthier-Villars
Thermal resistance between amorphous silica nanoparticles

Nanoparticle-based materials have been used as thermal insulation in a variety of macroscale and microscale applications. In this work, we investigate the heat transfer between nanoparticles using non-equilibrium molecular dynamics simulations. We calculate the total thermal resistance and thermal boundary resistance between adjacent amorphous silica nanoparticles. Numerical results are compared to interparticle resistances determined from experimental measurements of heat transfer across packed silica nanoparticle beds. The thermal resistance between nanoparticles is shown to increase rapidly as the particle contact radius decreases. More significantly, the interparticle resistance depends strongly on the forces between particles, in particular, the presence or absence of chemical bonds between nanoparticles. In addition, the effect of interfacial force strength on thermal resistance increases as the nanoparticle diameter decreases. The simulations results are shown to be in good agreement with experimen.
A STUDY ON THE ERROR OF DISTRIBUTED ALGORITHMS FOR BIG DATA CLASSIFICATION WITH SVM

The error of a distributed algorithm for big data classification with a support vector machine (SVM) is analysed in this paper. First, the given big data sets are divided into small subsets, on which the classical SVM with Gaussian kernels is used. Then, the classification error of the SVM for each subset is analysed based on the Tsybakov exponent, geometric noise, and width of the Gaussian kernels. Finally, the whole error of the distributed algorithm is estimated in terms of the error of each subset.
Discourse anaphoricity vs. perspective sensitivity in emoji semantics

This paper aims to provide a foundation for studying the interplay between emoji and linguistic (natural language) expressions; it does so by proposing a formal semantic classification of emoji-text combinations, focusing on two core sets of emoji: face emoji and activity emoji. Based on different data sources (introspective intuitions, naturalistic Twitter examples, and experimental evidence), we argue that activity emoji (case study I) are essentially event descriptions that serve as separate discourse units (similar to free adjuncts ) and connect to the accompanying (linguistic) text by virtue of suitable discourse relations. By contrast, face emoji (case study II) are expressive elements that are anchored to an attitude holder and comment on a proposition provided by the accompanying text. We provide further evidence for the distinct behavior of face emoji and activity emoji by looking at their scopal behavior with respect to linguistically-expressed negation. In particular, we probe interactions of emoji and texts that contain clausal negation, and conclude that both face emoji and activity emoji generally do not scope under negation. However, the appearance of such a scope relation arises with activity emoji when the emoji are connected to the accompanying text by virtue of an Explanation discourse relation. With face emoji, scopal interactions seem to appear in cases where the default interpretation would result in a discourse contribution that is pragmatically infelicitous, and also in cases that involve a specialized emoji-repetition construction where a repeated alternation of face emoji with words assumes a scope-marking role.
Control and surveillance of partially observed stochastic epidemics in a Bayesian framework

This thesis comprises a number of inter-related parts. For most of the thesis we are concerned with developing a new statistical technique that can enable the identification of the optimal control by comparing competing control strategies for stochastic epidemic models in real time. In the second part, we develop a novel approach for modelling the spread of Peste des Petits Ruminants (PPR) virus within a given country and the risk of introduction to other countries. The control of highly infectious diseases of agriculture crops, animal and human diseases is considered as one of the key challenges in epidemiological and ecological modelling. Previous methods for analysis of epidemics, in which different controls are compared, do not make full use of the trajectory of the epidemic. Most methods use the information provided by the model parameters which may consider partial information on the epidemic trajectory, so for example the same control strategy may lead to different outcomes when the experiment is repeated. Also, by using partial information it is observed that it might need more simulated realisations when comparing two different controls. We introduce a statistical technique that makes full use of the available information in estimating the effect of competing control strategies on real-time epidemic outbreaks. The key to this approach lies in identifying a suitable mechanism to couple epidemics, which could be unaffected by controls. To that end, we use the Sellke construction as a latent process to link epidemics with different control strategies. The method is initially applied on non-spatial processes including SIR and SIS models assuming that there are no observation data available before moving on to more complex models that explicitly represent the spatial nature of the epidemic spread. In the latter case, the analysis is conditioned on some observed data and inference on the model parameters is performed in Bayesian framework using the Markov Chain Monte Carlo (MCMC) techniques coupled with the data augmentation methods. The methodology is applied on various simulated data sets and to citrus canker data from Florida. Results suggest that the approach leads to highly positively correlated outcomes of different controls, thus reducing the variability between the effect of different control strategies, hence providing a more efficient estimator of their expected differences. Therefore, a reduction of the number of realisations required to
Geometric function theory for certain slice regular functions

In this paper, we shall study the geometric function theory for slice regular functions of a quaternionic variable. Specially, we give some coefficient estimates for slice regular functions among which a version of the Bieberbach theorem and the Fekete-Szeg\"{o} inequality for a subclass of slice regular functions are presented. The growth and distortion theorems for this class are also established. Finally, we give a Bloch theorem for slice regular functions with convex image.
ASYMPTOTIC DECOMPOSITION OF LINEAR SINGULARLY PERTURBED MULTISCALE SYSTEMS

The theory of singularly perturbed systems of differential equations has been intensively developed recently, and its methods have been widely used for the study of various problems of science and technology. Singularly perturbed models describe dynamic processes in physics, theory of automatic control, hydroscopic systems, economical and biological processes [2,3]. Singularly perturbed systems have boundary layer and stiffness property in numerical calculations. In this connection the main results for high-dimensional systems with fast and slow variables boil down to the construction of asymptotic expansions of the initial and boundary problems. Let us note the surveys [6, 8, 13], where a great amount of works dedicated to this subject were analyzed. For qualitative studies of entire systems it is expedient to apply decomposition algorithms. Effective methods of decomposition of singularly perturbed systems, which are based on the ideas of the integral manifold method, were developed in the works [11, 12]. For linear singularly perturbed systems such an approach allows us to make the decomposition of an input system to the independent fast and slow subsystems [7,10]. Linear non-autonomous three-time and n-time scale systems were studied in [1, 4, 9].
Probabilistic penalized principal component analysis

A variable selection method based on probabilistic principal component analysis (PCA) using penalized likelihood method is proposed. The proposed method is a two-step variable reduction method. The ﬁrst step is based on the probabilistic principal component idea to identify principle components. The penalty function is used to identify important variables in each component. We then build a model on the original data space instead of building on the rotated data space through latent variables (principal components) because the proposed method achieves the goal of dimension reduction through identifying important observed variables. Consequently, the proposed method is of more practical use. The proposed estimators perform as the oracle procedure and are root-n consistent with a proper choice of regularization parameters. The proposed method can be successfully applied to high-dimensional PCA problems with a relatively large portion of irrelevant variables included in the data set. It is straightforward to extend our likelihood method in handling problems with missing observations using EM algorithms. Further, it could be e ﬀ ectively applied in cases where some data vectors exhibit one or more missing values at random.
Research on Air Quality of Beijing-Tianjin-Hebei Region based on SVM and Regression Analysis

The air pollution of Beijing-Tianjin-Hebei region in China becomes increasingly serious. Focus on the air quality management of Beijing-Tianjin-Hebei region, this paper proposes a method based on SVM algorithm and multivariate linear regression to the prediction and evaluation of air quality. First, it builds the evaluation metrics based on the weather factors, the correlation of neighbor cities, and their combination. Furthermore, it applies the SVM algorithm to the classification and prediction of air quality of Beijing-Tianjin-Hebei region. By the application of multivariate linear regression method, the weather factor with no significant effect on air quality is removed to save the cost of calculation. Finally, the experimental results show that the method based on the combination of weather factors and correlation of neighbor cities is better than the other two methods. We draw the conclusion that the method is feasible and effective. Keywords—support vector machine (SVM); data mining; multivariate linear regression; air quality index (AQI)
Influence of water content on structural and electrochromic properties of TiO 2 nanotube

TiO 2 nanotubes (TNTs) and bamboo-type TNTs structure films were synthesized via anodization from sputtered titanium (Ti) films on indium tin oxide (ITO) glass. Herein, the anodization process was adjusted electrolyte with different amounts of deionized water and ethylene glycol. The optical and structural properties of all films before and after annealing were investigated, which affected electrochromic application. The increasing deionized water content in electrolytes resulted in an increase in the average diameter and a decrease in the average length of TNTs. Furthermore, the bamboo-type TNTs structure was produced at the deionized water volume condition of 3 vol%. The crystallite size of annealed TNTs (a-TNTs) was calculated from the Scherrer equation, which was enhanced when increasing deionized water. TNTs conditions before annealing showed that the amorphous structure and high energy band gap (E g ) exhibited more electrochromic phenomena than the crystal structure. Due
Early Experiences of Parents of Children who are Deaf or Hard of Hearing: Navigating through Identification, Intervention, and Beyond

Guidelines created by the Joint Committee on Infant Hearing ([JCIH], 2019) were designed to aid in the early identification of infant hearing loss. Despite these guidelines, a quarter of children who do not pass their initial screening are lost to the follow-up process and many more do not receive care in line with the 1-3-6 guidelines (Centers for Disease Control and Prevention [CDC], 2018; JCIH, 2019). To acquire more information about the experiences of families and identify specific barriers to timely diagnosis and intervention, interviews were conducted with 13 parents of children who are deaf or hard of hearing whose children were enrolled in a larger longitudinal study. These interviews revealed common themes regarding delayed identification, frustrations about timely intervention, and confusion when choosing communication modalities. Common themes amongst families who felt well-supported were also identified.
Análisis espacialmente resuelto de la tasa de formación estelar y su densidad cósmica en galaxias cercanas

La formacion estelar es uno de los procesos fisicos mas relevantes que determinan la formacion de las galaxias, ademas de ser un factor esencial para su evolucion. Esta Tesis Doctoral tiene como objetivo abordar el tema de la formacion estelar en galaxias cercanas explorando distintas escalas fisicas que van desde las galaxias como sistemas completos hasta las diferentes componentes estructurales que las forman, tales como bulbos, barras, y discos. La manera de proceder ha sido la siguiente, (I) se ha determinado la tasa de formacion estelar actual en galaxias externas desde una perspectiva global, (II) se ha analizado la variacion de la tasa de formacion estelar a lo largo de las distintas estructuras internas que moldean las galaxias (bulbos, barras, y discos) con el objetivo de caracterizar los procesos de activacion y quenching presentes, (III) finalmente, se proporcionan los valores de la densidad de la tasa de formacion estelar para las galaxias y para sus componentes. La aparicion de tecnicas de espectroscopia de campo integral (del ingles, Integral Field Spectroscopy), que combinan al mismo tiempo las ventajas de la imagen y la espectroscopia clasica, es especialmente apropiada para el estudio en dos dimensiones de la estructura de las galaxias. Esta tecnica permite tener informacion espacial y espectral de manera simultanea. Por ello, a lo largo de esta tesis, hemos usado los datos IFS de la exploracion de galaxias cercanas CALIFA (Calar Alto Legacy Integral Field Area Survey).
On the Application of the Three-Step Approach to Growth Mixture Models

This series of simulation studies evaluate, in the context of applied research settings, the impact of the parameterization of the covariance structure of the growth mixture model (GMM) on the regression coefficient and standard error estimates in the 3-step method. The results show that the 1-step approach performs better than the 3-step method across the simulation studies. However, the performance of the 3-step method depends slightly or importantly on the parameterization of the GGM from the first step, on the inclusion or not of the predictor at the first step of the analysis, on the population model, and on the type (i.e., logit vs. linear) and size of the regression coefficient estimates.
Isolation, Structural Characteristics Analysis of a Vigna unguiculata Polysaccharide VUP80-3 and Its Protective Effect on GES-1 Cells In Vitro

Cowpea (Vigna unguiculata) is one of the main edible legume vegetables in China, and it can improve spleen and stomach function. A polysaccharide component (VUP80-3) has been isolated from V. unguiculata in this study. The average molecular weight of VUP80-3 is 6.43 × 104 Da, and the main monosaccharide group is glucose. The mass ratio of monosaccharide groups in the polysaccharide was glucose:galactose:arabinose:rhamnose:xylose:mannose:fucose = 152.36:24.50:16.53:8.13:1.26:0.97:0.82. NMR analysis showed that VUP80-3 has →4)-α-D-Galp (1→ and →4)-α-D-Glcp(1→ main chain and →3,4)-β-D-Glcp(1→, →4,6)-α-D-Glcp(1→ branch chains, and the terminal sugar is α-D-Glcp(1→. Biological activity test results showed that VUP80-3 at 1000 μg·mL−1 significantly increased the activity of ethanol injured GES-1 cells (p < 0.01) and significantly reduced reactive oxygen species (ROS) in ethanol injured GES-1 cells and inflammatory factors (IL-8, IL-1β and TNF-α,) in GES-1 cells. This compound also reduced the apoptosis rate (p < 0.05), thereby significantly reducing the oxidative damage caused by ethanol in GES-1 cells. Therefore, VUP80-3 is a potential drug to protect the gastric mucosa from damage.
R-R Interval Outlier Processing for Heart Rate Variability Analysis using Wearable ECG Devices

Electrocardiograms (ECGs) captured by wearable ECG devices readily contain artifacts due to measurement faults. Since artifacts and R waves have quite similar frequency characteristics, R wave misdetection or R-R interval (RRI) miscalculation may result. Aiming at accurate analysis of heart rate variability (HRV), this paper proposes a new RRI outlier processing method consisting of three steps: evaluating RRI reliability, excluding RRI outlier, and complementing missing RRI. In the rst step, the method evaluates the measurement status of all detected R waves and calculates RRI reliability based on the measurement status of a combination of the measurement status of two R waves. Since we target wearable ECG devices used in non-medical environment, the method evaluates R waves based on the threshold electric potential for left ventricular hypertrophy, and determines those exceeding the threshold as artifacts. The method accordingly sets lower reliability to RRIs containing R waves evaluated as artifacts. In the second step, the method excludes all RRIs with low reliability as outliers. These steps may be effective for HRV measures in the time domain, but are not suf cient for analyzing HRV measures in the frequency domain. Resampling the time series RRI data, which is essential for analyzing HRV in the frequency domain, may produce outliers if the target RRIs contain missing values. Our method accordingly complements missing RRIs before data resampling based on RRI characteristics. We postulate that consecutive changes in RRIs follow a simple formula consisting of three components: direct current, low frequency, and high frequency. Our method complements missing values according to the formula, which is calculated from RRIs time series regarded as having been properly measured. To con rm the effectiveness of the method before applying it to ECGs recorded by wearable devices, we evaluated all the steps using pseudo-ECGs generated arti cially by adding noise and artifacts to open ECG data. Initial evaluation results showed that the proposed method outperformed conventional method regarding the precision of both time and frequency domain measures of HRV.
Nonparametric Bayesian analysis for support boundary recovery

Given a sample of a Poisson point process with intensity $\lambda_f(x,y) = n \mathbf{1}(f(x) \leq y),$ we study recovery of the boundary function $f$ from a nonparametric Bayes perspective. Because of the irregularity of this model, the analysis is non-standard. We derive contraction rates with respect to the $L^1$-norm for several classes of priors, including Gaussian priors, priors based on (truncated) random series, compound Poisson processes, and subordinators. We also investigate the limiting shape of the posterior distribution and derive a nonparametric version of the Bernstein-von Mises theorem for a specific class of priors on a function space with increasing parameter dimension. We show that the marginal posterior of the functional $\vartheta =\int f$ does some automatic bias correction and contracts with a faster rate than the MLE. In this case, $1-\alpha$-credible sets are also asymptotic $1-\alpha$ confidence intervals. It is also shown that the frequentist coverage of credible sets is lost under model misspecification.
Circulant Graphs without Cayley Isomorphism Property with = 7

A circulant graphCn (R) is said to have the Cayley Isomorphism (CI) property if whenever Cn (S)is isomorphic toCn (R), there is some a∈Zn ∗ for which S = aR.In this paper, we prove that C27n (R), C27n (S)and C27n (T)are isomorphic circulant graphs without CI-property whereR = {1, 9n-1, 9n+1, 3p1, 3p2, . , 3pk−2}, S = {3n+1, 6n-1, 12n+1, 3p1, 3p2, . , 3pk−2},T = {3n-1, 6n+1,12n-1, 3p1, 3p2, . ,3pk−2},k ≥ 3, gcd(p1, p2,., pk−2) = 1 and n, p1,p2,. ,pk−2Nand also obtain new abelian groups from these isomorphic circulant graphs. -----------------------------------------------------------AMS Subject Classification: 05C60, 05C25.