Miracle-dz/UniFAR-FTUs huggingface dataset:
Variable selection under multicollinearity using modified log penalty

ABSTRACT To handle the multicollinearity issues in the regression analysis, a class of ‘strictly concave penalty function’ is described in this paper. As an example, a new penalty function called ‘modified log penalty’ is introduced. The penalized estimator based on strictly concave penalties enjoys the oracle property under certain regularity conditions discussed in the literature. In the multicollinearity cases where such conditions are not applicable, the behaviors of the strictly concave penalties are discussed through examples involving strongly correlated covariates. Real data examples and simulation studies are provided to show the finite-sample performance of the modified log penalty in terms of prediction error under scenarios exhibiting multicollinearity.
Estimation of heavy metal concentration in rice leaves of farmland by hyperspectral leaf reflectance and partial least square regression

Protecting people from heavy metal contamination is an important public-health concern and a major national environmental issue in China. The objective of this study was to quantitatively estimate the heavy metal concentration in rice leaves using leaf hyperspectral data and partial least squares regression (PLSR) models. 21 rice leaf samples and spectrum were gathered from farmlands in Zhangjiagang area, China. Copper (Cu), Cadmium (Cd) concentrations of rice leaves were measured within the lab. Firstly, the spectral data were treated by some methods, including, original reflectance (OS), First Derivative (FD) and Second Derivative (SD). Secondly, in order to select input variables for PLSR models, the correlation analysis between heavy metal concentration and spectral bands (OS, FD and SD), spectral indices were performed. Finally, we constructed the PLSR models between heavy metal concentration and spectrum. The results showed that correlation coefficients between Cu concentration and spectral data were higher than Cd. And that the bands significant correlation (P<0.05) with Cu concentration were far more than Cd. Ultimately, we selected 453 variables (442 bands and 11 spectral indices) and 19 variables (18 bands and 1 spectral index) as input variables of PLSR model for Cu and Cd, respectively. Moreover, we found that the Cu and Cd concentrations significantly correlated with spectral variables for (R2=0.41, RMSE=1.93) and (R2=0.38, RMSE=0.018) of PLSR models, respectively. These results indicated that they were good predicting models for estimating heavy metal concentration in rice leaves.
Velocity field and crustal deformation of broader Athens plain (Greece) from a dense geodetic network

Abstract The broader area of Athens, a region exhibiting relatively low crustal deformation, was stroke in 1999 by a catastrophic earthquake posing serious questions regarding strain accumulation in slow deforming regions located within active geodynamic regimes. In the present study, the establishment of a dense geodetic network, primarily designed to monitor local tectonic movements is reported. A comprehensive GNSS velocity field, over the period 2005–2008, as well as calculated geodetic strain rates is presented. It is shown that a single strain tensor is insufficient to express the heterogeneity of the local geodetic field. Local variability of strain is successfully depicted, indicating the western part of Athens as the area of higher strain accumulation. Maximum dilatation rates occur along a NNE-SSW direction between Parnitha Mt. and Thriasio basin. The observed dilatation can be associated to WNW-ESE trending active fault zones, which appear to abruptly terminate towards East along a major NNE-SSW Miocene tectonic boundary. These findings are consistent to the stress field responsible for the Athens 1999 earthquake, also in agreement with geological and tectonic observations. Finally, the implications of the observed motion field on the understanding of the kinematics and dynamics of the region as well as the role of inherited inactive tectonic structures are discussed.
Improved Algorithm for Pathological and Normal Voices Identification

There are a lot of papers on automatic classification between normal and pathological voices, but they have the lack in the degree of severity estimation of the identified voice disorders. Building a model of pathological and normal voices identification, that can also evaluate the degree of severity of the identified voice disorders among students. In the present work, we present an automatic classifier using acoustical measurements on registered sustained vowels /a/ and pattern recognition tools based on neural networks. The training set was done by classifying students’ recorded voices based on threshold from the literature. We retrieve the pitch, jitter, shimmer and harmonic-to-noise ratio values of the speech utterance /a/, which constitute the input vector of the neural network. The degree of severity is estimated to evaluate how the parameters are far from the standard values based on the percent of normal and pathological values. In this work, the base data used for testing the proposed algorithm of the neural network is formed by healthy and pathological voices from German database of voice disorders. The performance of the proposed algorithm is evaluated in a term of the accuracy (97.9%), sensitivity (1.6%), and specificity (95.1%). The classification rate is 90% for normal class and 95% for pathological class.
Modeling discharge coefficient of triangular plan form weirs using extreme learning machine

In this paper, for the first time, the discharge coefficient of triangular plan form weirs is simulated by the extreme learning machine (ELM). ELM is one of the powerful and rapid artificial intelligence methods in modeling complex and non-linear phenomena. Compared to other learning algorithms such as back propagation, this model acts rapidly in the learning process and provides a desirable performance in processing generalized functions. In this study, the Monte Carlo simulation is used for examining capabilities of numerical models. Also, the k-fold cross validation method with k=5 is utilized for evaluating abilities of the ELM models. Then, six ELM models are introduced by means of the parameters affecting the discharge coefficient of triangular plan form weirs. After that, the superior model is identified by analyzing the results of the mentioned models. The superior model predicts discharge coefficient values with reasonable accuracy. This model simulates the discharge coefficient as a function of the flow Froude number, vertex angle of the triangular plan form weir, the ratio of weir length to its height, the ratio of flow head to weir height and the ratio of channel width to weir length. For the best model, the Mean Absolute Error, Root Mean Square Error and determination coefficient are computed 1.173, 0.012 and 0.967, respectively. Furthermore, examination of the influence of the input parameters indicates that the flow Froude number is the most influenced factor in modeling the discharge coefficient. Also, the error distribution showed that roughly 86 % of the superior model results had an error less than 2 %. Furthermore, a practical equation was provided to compute the discharge coefficient.
Effect of Computerized Gloss Presentation Format on Reading Comprehension: A Cognitive Load Perspective

In recent years, gloss presentation format or the location where a gloss appears with respect to its related target word has received renewed attention. Research suggested that different gloss presentation formats could have differential effects on reading comprehension and/or vocabulary learning. This study hypothesized that the effectiveness of different computerized gloss presentation formats in reading comprehension could be explained by drawing on the split-attention effect within the framework of cognitive load theory. The effect predicts that when two related sources of information are physically separated (e.g., a target word and the respective gloss), cognitive resources are unnecessarily wasted, and learning is hindered. To test this hypothesis, 39 Persianspeaking L2 learners of English were divided into two experimental conditions, each being exposed to a text enhanced with either in-text or marginal glosses. Two measures of reading comprehension and three measures of cognitive load were employed. The participants’ initial differences in terms of grammatical knowledge and vocabulary size were balanced out, and their lookup behavior was also tracked. The results revealed that the participants with access to in-text glosses, compared with those with marginal glosses, experienced lower levels of cognitive load due to the elimination of split-attention and, accordingly, performed better on the reading comprehension measures. Given the participants’ L2 proficiency level, the findings suggested that a text enhanced with in-text glosses tends to be instructionally more efficient.
Assessing Italian Research in Statistics:Interdisciplinary or Multidisciplinary?

In this paper, we assess cross disciplinary of research produced by the Italian Academic Statisticians (IAS) combining text mining and bibliometrics techniques Textual and bibliometric approaches have together advantages and disadvantages, and provide different views on the same interlinked corpus of scientific publications. In addition textual information in such documents, jointly citations also constitute huge networks that yield additional information. We incorporate both points of view and show how to improve on existing text-based and bibliometric methods. In particular, we propose an hybrid clustering procedure based on Fisher ╒s inverse chi-square method as the preferred method for integrating textual content and citation information. Given clustered papers, it’s possible to evaluate ISI subject categories (SCs) as descriptive labels for statistical documents, and to address individual researchers interdisciplinary.
Asymptotics and scaling analysis of 2-dimensional lattice models of vesicles and polymers

The subject of this thesis is the asymptotic behaviour of generating functions of di erent combinatorial models of two-dimensional lattice walks and polygons, enumerated with respect to di erent parameters, such as perimeter, number of steps and area. These models occur in various applications in physics, computer science and biology. In particular, they can be seen as simple models of biological vesicles or polymers. Of particular interest is the singular behaviour of the generating functions around special, so-called multicritical points in their parameter space, which correspond physically to phase transitions. The singular behaviour around the multicritical point is described by a scaling function, alongside a small set of critical exponents. Apart from some non-rigorous heuristics, our asymptotic analysis mainly consists in applying the method of steepest descents to a suitable integral expression for the exact solution for the generating function of a given model. The similar mathematical structure of the exact solutions of the di erent models allows for a uni ed treatment. In the saddle point analysis, the multicritical points correspond to points in the parameter space at which several saddle points of the integral kernels coalesce. Generically, two saddle points coalesce, in which case the scaling function is expressible in terms of the Airy function. As we will see, this is the case for Dyck and Schröder paths, directed column-convex polygons and partially directed
Determinación de ajustes de la protección de sobrecorriente en base a la estimación de corrientes de cortocircuito usando mediciones locales

En los Sistemas Electricos de Distribucion (SED´s), la proteccion de sobrecorriente es la mas propensa a tener descoordinacion en su operacion, ya que su desempeno depende directamente de los niveles de corriente de cortocircuito (Icc) y estas dependen del equivalente Thevenin de la red aguas arriba. Los cambios del sistema aguas arriba de la proteccion de sobrecorriente originan variaciones del equivalente Thevenin y por consiguiente variaciones de las Icc, que al mantener ajustes fijos en la proteccion de sobrecorriente puede provocar problemas de selectividad en los sistemas de proteccion. El presente trabajo plantea desarrollar un esquema para la proteccion de sobrecorriente con la capacidad de variar sus ajustes en funcion de la Icc que se presente en el SED, para mitigar las posibles descoordinaciones por los efectos de la variacion de la Icc por cambios del sistema aguas arriba. Para calcular la Icc, se emplea la norma IEC 60909, utilizando el equivalente de Thevenin de prefalla que se obtiene en funcion de la medicion de voltajes y corrientes adquiridos en la ubicacion del rele. La metodologia planteada se desarrolla en PowerFactory – DigSilent y se verifica en el sistema de pruebas IEEE - Distribution Test Feeders 13-bus Feeder.
Dynamic Modeling and Development of Symbolic Calculation Software for N-DOF Flexible-Link Manipulators Incorporating Lumped Mass

Considering the complex dynamic modeling of multi-DOF planar flexible manipulators, a general-purpose method for the rigid-flexible coupling dynamic modeling of N-DOF flexible manipulators is proposed in this paper, and symbolic calculation software is developed. The modeling method is based on the Lagrange equation and assumed mode method (AMM). First, the N-DOF flexible manipulator is divided into two parts, which are assumed to be rigid and flexible. On this basis, the rigid part and the flexible part are coupled, and the calculation process of the model is further simplified. Then, the simplest general symbolic expression of the dynamic model of the N-DOF flexible manipulator is obtained with the induction method. According to the modeling method, “symbolic expression computation software for dynamic equations of N-DOF flexible manipulators” is developed using the symbolic calculation software Mathematica. Finally, the dynamic modeling method and the symbolic calculation software are verified by a trajectory tracking experiment with a PD control applied to a 2-DOF flexible manipulator. Compared with the traditional modeling method, the calculation time can be reduced by more than 90% using the modeling method proposed in this paper, which significantly reduces the complexity of the modeling process.
Une méthode de martingales pour la convergence d'une suite de processus de sauts markoviens vers une diffusion associée à une condition frontière. Application aux systèmes de files d'attente

We describe a convenient method for proving weak convergence of a sequence of markovian time-homogeneous pur jump processes X~ to a diffusion process in a closed subset G of IRP with a boundary ôG which is piecewise smooth. Basically it is shown that the limit solves a continuous sub-martingale problem. Because the state space has a boundary, we think it is not very adapted to apply the classical approach developped by Kurtz and based on semigroup theory : in particular, it is difficult to find a dense class of test functions. With our martingale and sub-martingale approach, we do not need to deal with this problem and the proofs are relatively simple. We study also an important example in queueing theory, which is not of Jackson-type. INTRODUCTION Déjà de nombreux auteurs se sont intéressés à la convergence d’une suite de processus de sauts vers un processus continu, convergence en probabilité uniforme ou convergence faible. Annales de l’Institut Henri Poincaré Section B Vol. XVII, 0020-2347/1981/351/a 5.00/ © Gauthier-Villars
Linguistic Analysis of Italian Perception and Speech Act Verbs

Two theoretical hypotheses are in the background of the present work, and of DELIS work in general: a corpus based lexicographical approach and a frame based semantic analysis. We assume that only a careful and detailed analysis of corpus data can constitute a sound basis for a realistic approach to lexicon building, be it a human oriented dictionary or a computationally oriented lexicon. Obviously corpus data cannot be used in a simplistic way. In order to become usable they must be analysed according to some theoretical hypothesis, according to which to model and structure what would be otherwise an unstructured set of data. The best mixture of empirical and theoretical approach is the one in which the theoretical hypothesis is itself emerging from and guided by successive analyses of the data, and is cyclically refined and adjusted to textual evidence.
Dynamic Event-Triggered Sliding Mode Control: Dealing With Slow Sampling Singularly Perturbed Systems

This brief endeavors to investigate the sliding mode control (SMC) issue of the networked singularly perturbed systems (SPSs) under slow sampling. For the energy saving purpose in network communication, a dynamic event-triggered mechanism is introduced to SMC design. By considering the structure characteristics of the controlled system, a novel sliding function is constructed with taking the singular perturbed matrix $E_\varepsilon $ into account properly. With the aid of some appropriate Lyapunov functionals, the sufficient conditions are derived to ensure the asymptotic stability of the sliding mode dynamics and the reachability of the specified sliding surface. Besides, it is shown that the quasi-sliding motion is dependent on the dynamic event-triggered parameters and its bound converges to a constant. The solving algorithm for the dynamic event-triggered SMC law is formulated in a convex optimization framework. Finally, an numerical example is provided to illustrate the effectiveness of the proposed results.
Significant Classes of NFA and their Random Generation

Random generation of non-deterministic finite automata (NFA) can be used to provide experimental average case analysis of algorithms on NFA and as means to randomized unit testing code that uses NFA. We study and implement known methods for random generation of NFA, and for each method we provide experimental results and classify them according to properties a uniform random generator should have. Important properties of a good random NFA generator include: ability to generate NFA that are non isomorphic, that is, always the same permutation of the NFA is generated; ability to fix the number of states of the generated automata; tractable running time for sampling a large number of instances, e.g. 10000, allowing the average case experiments to meet certain confidence levels; ability to generate automata that are initially connected, i.e. all states are accessible. Our research resulted in the identification of a specific class of NFA for which the aforementioned important properties are verified. Experimental results showed that this class is almost as succinct as NFA, proving the generator to be a candidate for sampling NFAs for statistically significant experiments.
Energy Rating for Different Module Technologies

It is very important for manufacturers, designers and end users to know in advance whether a PV module behaves in operating conditions better than another one. ENEA has developed a customized measurement system made of electronic loads and an High speed data acquisition system able to acquire automatically IV curves at different temperature and irradiation levels. Before being submitted to the outdoor measurements, the photovoltaic modules have been characterized in ENEA laboratory in order to evaluate the nominal powers. Performance Ratio (PR) has been evaluated during outdoor measurements for crystalline-Si and CIGS PV modules so has been possible to make comparative evaluations among the modules technologies.
An investigation on modeling and compensation of synthetic geometric errors on large machine tools based on moving least squares method

This article intends to provide an efficient modeling and compensation method for the synthetic geometric errors of large machine tools. Analytical and experimental examinations were carried out on a large gantry-type machine tool to study the spatial geometric error distribution within the machine workspace. The result shows that the position accuracy of the tool-tip is affected by all the translational axes synchronously, and the position error curve shape is non-linear and irregular. Moreover, the angular error combined with Abbe’s offset during the motion of a translational axis would cause Abbe’s error and generate significant influence on the spatial positioning accuracy. In order to identify the combined effect of the individual error component on the tool-tip position accuracy, a synthetic geometric error model is established for the gantry-type machine tool. Also, an automatic modeling algorithm is proposed to approximate the geometric error parameters based on moving least squares in combination with Chebyshev polynomials, and it could approximate the irregular geometric error curves with high-order continuity and consistency with a low-order basis function. Then, to implement real-time error compensation on large machine tools, an intelligent compensation system is developed based on the fast Ethernet data interaction technique and external machine origin shift, and experiment validations on the gantry-type machine tool showed that the position accuracy could be improved by 90% and the machining precision could be improved by 85% after error compensation.
EVOLVABLE HARDWARE REALIZED WITH FUNCTION TYPE PROGRAMMABLE DEVICE

How does hardware evolve? In 1992, Evolvable Hardware (E Hard or EHW) was proposed by Dr. Hugo de Garis in order to develop a new kind of hardware which can change its architecture as the organism to adapt the environment.To evolve a complex FPGA with length of 300,000 bits of chromosome by EA is very difficult now,especially the speed of evolution is the key problem.There are two ways to solve this problem.One is to design EHW oriented algorithms such as variable length chromosome GA;Another way is to design new device structure which meets the requirements of evolvable hardware.In this paper,the new functional programmable device is proposed as EHW′s structure.A 6 multiplexor and a 4 bit comparator are evolved to carried out on GAL through evolution by variable length chromosome GA. The experimental results show that functional programmable device is feasible and worthy of further research.
Centralized Mobility Prediction Support in a Hierarchical Architecture

The hierarchical Infostations system provides intermittent but very high speed rate. Since the coverage area is small, it is essential to avoid the bandwidth wasting due to the overall delay. For doing so, a new approach to predict the mobility in a wireless environment is proposed in this paper. We start by highlighting the limitation of the classical protocols in a hierarchical architecture. Then, we propose a centralized approach to handle a new mobility prediction protocol. Our protocol is based on a graph table that dynamically configures itself according to the terminals' mobility. The simulation shows that the proposed approach improves the service performance at the price of increasing the cache size.
Intra-and inter-session channel provisioning for video distribution in wireless networks with heterogeneous users

This paper presents a formal study on channelized bandwidth resource provisioning for multi-rate and multi-session video broadcast in a broadband wireless network with heterogeneous users. The formulation is generic in that it considers both inter-session and intra-session wireless resource allocation. It also takes into account the most fundamental issues associated with video transmission including encoding complexity, transport overhead, non-linear relationship between the receiver perceived video quality and the delivered bandwidth, and intra- and inter-session fairness. In addition, we derive an optimal allocation scheme to manage the scarce wireless resources.