Miracle-dz/UniFAR-FTUs huggingface dataset:
MODELADO Y SIMULACIÓN DE UN REGULADOR DE VELOCIDAD PARA UN MOTOR BLDC POR MEDIO DE UN CONTROLADOR DE HISTÉRESIS POR CORRIENTE (MODELING AND SIMULATION OF A SPEED CONTROLLER FOR A BLDC MOTOR, USING A HYSTERESIS CURRENT CONTROLLER)

En este documento se presenta el modelado de un motor BLDC (Brushless de corriente directa), se analiza su comportamiento dinamico a lazo cerrado, que esta conformado de dos bucles uno interno y uno externo. El bucle interno consta de un controlador de histeresis de corriente en conjunto con un detector de cruce por cero de fuerza contra-electromotriz, que hace cumplir los comandos de corriente de fase en el estator proporcionados por el bucle externo, que cumple con la ley clasica de control PID en su version de velocidad, que toma como referencia el valor de velocidad angular, dicha variable es obtenida despues de derivar la informacion obtenida del detector de cruce por cero. El sistema es simulado en Matlab/Simulink, donde se observa que el sistema cumple su objetivo llevando la velocidad del motor al valor de referencia, el sistema es sometido a perturbaciones y el controlador responde de manera eficiente. Modeling of BLDC (brushless direct current) motor in this paper is presented, its dynamic behavior in a closed loop is analyzed with two loops, the first one, internal loop, consist of a current hysteresis controller and a zero crossing detector of the back electromotive force, enforces the stator phase current commands provided by the second external loop, which consists of a classic PID control law in its speed version to adjust the angular velocity at reference value, this variable is obtained after deriving the information obtained from the zero crossing detector. The system is simulated in Matlab / Simulink, it is observed that the system achieves its objective by bringing the motor speed to the reference value, the system is subjected to disturbances and the controller responds efficiently.
An overview on skew constacyclic codes and their subclass of LCD codes

<p style='text-indent:20px;'>This paper is about a first characterization of LCD skew constacyclic codes and some constructions of LCD skew cyclic and skew negacyclic codes over <inline-formula><tex-math id="M1">\begin{document}$ \mathbb{F}_{p^2} $\end{document}</tex-math></inline-formula>. </p>
Comparative study on transverse mode instability of fiber amplifiers based on long tapered fiber and conventional uniform fiber

Compared with conventional uniform fibers, long tapered fibers provide an effective way to maintain beam quality and suppress the generation of nonlinear effects in fiber lasers. In this work, the transverse mode instability (TMI) of two amplifiers based on ytterbium-doped fiber (YDF) with uniform core diameter and tapered core diameter has been investigated experimentally. For a reasonable comparison of TMI in these two fiber amplifiers, the same effective core diameters and design parameters are applied to both. In the uniform YDF amplifier, the TMI threshold is around 1046 W, and the beam quality M2 factor increases with the power and reaches 3.2 when the power is around 1500 W. In a tapered YDF (T-YDF) amplifier, the maximum output power is up to 2170 W with a beam quality of M2 ~ 2.2 and no sign of TMI is observed. To the best of our knowledge, this is the first reported all-fiber tapered fiber laser with a 2 kW-level average output power. The experimental results and theoretical analysis indicate that the TMI threshold of the T-YDF amplifier is higher than the uniform YDF amplifier in spite of sharing the same effective core diameter.
Reconstruction of scenes using a hand-held range imaging camera

The current nal degree project covers the development of a C++ program to reconstruct 3D scenes from a stream of incoming RGBD images from the Kinect for Windows v2 sensor using the PCL library and the libfreenect2 open source Kinect drivers. A background analysis is performed to analyze state of the art registration algorithms and similar registration applications which are already distributed. All the computing steps are explained and detailed, from the data acquisition through the coarse and ne alignment steps to the nal surface reconstruction algorithm. Several algorithms are discussed for each step, giving reasons for the nal algorithm choice and the parameters set. Finally, a brief discussion on the results and problems encountered during the development of the project serves as the basis of a proposal of improvements for future work on the subject. The project budget and the environmental impact are analyzed before the nal conclusion chapter.
Directional Multifractal Analysis in the Lp Setting

The classical Hölder regularity is restricted to locally bounded functions and takes only positive values. The local Lp regularity covers unbounded functions and negative values. Nevertheless, it has the same apparent regularity in all directions. In the present work, we study a recent notion of directional local Lp regularity introduced by Jaffard. We provide its characterization by a supremum of a wide range oriented anisotropic Triebel wavelet coefficients and leaders. In addition, we deduce estimates on the Hausdorff dimension of the set of points where the directional local Lp regularity does not exceed a given value. The obtained results are illustrated by some examples of self-affine cascade functions.
Image Feature Extraction and Object Recognition Based on Vision Neural Mechanism

As an important branch of artificial intelligence, computer vision plays a huge role in the rapid development of artificial intelligence. From a biological point of view, in the acquisition and processing of information, vision is much more important than hearing, touch, etc., because 70% of the human cerebral cortex is processing visual information. Therefore, advances in computer vision technology are critical to the development of artificial intelligence that is designed to allow machines to think and handle things like humans. The acquisition and processing of visual information has always been the focus of computer vision research, and it is also difficult. The main problem of traditional computer vision technology in the processing of visual information is that the extracted image features are less discriminative, the generalization ability of image features in complex background scenes is insufficient, and the recognition ability on object recognition is poor. In response to these problems, based on the visual neural mechanism, this paper establishes an appropriate computer model for the neuronal cells in the human primary visual cortex, models the recognition response mechanism of the visual ventral system, and performs image feature extraction on the training samples. And object recognition. The results show that compared with the traditional methods, the proposed method effectively improves the discrimination of image features, and the image features extracted under complex background scenes have good generalization ability. On this basis, the training samples can be effectively recognized. The results show that the model based on the visual neural mechanism, the recognition of the edge, orientation and contour of the training sample show the advantages of the biological vision mechanism in object recognition.
Modification of the Maximin and ϕp (Phi) Criteria to Achieve Statistically Uniform Distribution of Sampling Points

Abstract This article proposes a sampling technique that delivers robust designs, that is, point sets selected from a design domain in the shape of a unit hypercube. The designs are guaranteed to provide a statistically uniform point distribution, meaning that every location has the same probability of being selected. Moreover, the designs are sample uniform, meaning that each individual design has its points spread evenly throughout the domain. The sample uniformity (often measured via a discrepancy criterion) is achieved using distance-based criteria ( or Maximin), that is, criteria normally used in space-filling designs. We show that the standard intersite metrics employed in distance-based criteria (Maximin and (phi)) do not deliver statistically uniform designs. Similarly, designs optimized via centered L2 discrepancy or support points are also not statistically uniform. When these designs (after optimization based on intersite distances) are used for Monte Carlo type of integration, their statistical nonuniformity is a serious problem as it may lead to a systematic bias. This article proposes using a periodic metric to guarantee the statistical uniformity of the family of distance-based designs. The presented designs used as benchmarks in the article are only taken from the class of Latin hypercube designs, which forces univariate projections to be uniform and improves accuracy in Monte Carlo integration of some functions. Supplementary materials for this article are available online.
A New Relaxation Time Model for Lattice Boltzmann Simulation of Nano
 Couette Flows in Wide Range of Flow Regimes

The standard LBM with the relaxation time is only able to simulate the flow features in continuum and slip regimes. In the present paper, a new relaxation time formulation considering the rarefaction effect on the viscosity for the lattice Boltzmann simulation of shear driven flows is presented in order to cover wide range of the flow regimes. The results show that in spite of the standard Lattice Boltzmann Method, LBM, the presented relaxation time equation is able to predict flow features in wide range of flow regimes including slip, transition and to some extend free molecular flow regimes. The velocity profiles, slip length and shear stress agree very well with DSMC (Direct Simulation Monte Carlo) and linear Boltzmann results.
Studi Kandungan Bakteri E.Coli pada Airtanah (Confined Aquifer) di Permukiman Padat Penduduk Desa Dasan Lekong, Kecamatan Sukamulia

Air sangat vital bagi kehidupan mahluk hidup, termasuk juga manusia. Air merupakan salah satu sarana dan media penyebaranberbagai macampenyakit. Penelitian ini bertujuan untuk menguji kualitas air sumur gali terhadap potensi pencemaran Escherichia coli. Penelitian berlokasi di daerah padat penduduk Desa Dasan Lekon, Kecamatan Sukamulia, Kabupaten Lombok Timur. Jenis penelitian adalah survai deskriptif, dengan mengambil 6 lokasi sampel air melalui pertimbangan arah kontur tinggi muka airtanah. Uji kualitas airtanah menggunakan metode MPN (Most Probable Number). Data dianalisis secara deskriptif dengan mengunakan tabel. Hasil penelitian memperoleh data bahwa semua sumur gali yang menjadi lokasi pengambilan sampel terkontaminasi bakteri E.coli dengan kisaran nilai 490 hingga lebih dari 24000 per 100 ml air sumur.Kontaminasi air sumur oleh bakteri E.coli berhubungan dengan sumber pencemar seperti septic tank, jarak sumur dengan sumber pencemar, tempat pembuangan sampah serta kondisi fasilitas sanitasi yang tidak memadai.
Multi-resource theories and applications to quantum thermodynamics

Resource theories are a set of tools, coming from the field of quantum information theory, that find applications in the study of several physical scenarios. These theories describe the physical world from the perspective of an agent, who acts over a system to modify its quantum state, while having at disposal a limited set of operations. A noticeable example of a physical theory which has recently been described with these tools is quantum thermodynamics, consisting in the study of thermodynamic phenomena at the nano-scale. In the standard approach to resource theories, it is usually the case that the constraints over the set of available operations single out a unique resource. In this thesis, we extend the resource theoretic framework to include situations where multiple resources can be identified, and we apply our findings to the study of quantum thermodynamics, to gain a better understanding of quantities like work and heat in the microscopic regime. We introduce a mathematical framework to study resource theories with multiple resources, and we explore under which conditions these multi-resource theories are reversible. Furthermore, we investigate the interconversion of resources, i.e., in which situations it is possible to exchange between two different kinds of resources. We then apply this formalism to quantum thermodynamics, where the two resources under consideration are energy and entropy. This multi-resource theory allows us to explore thermodynamics when the system under examination is closed or coupled with a thermal environment with a finite size. In addition to our work on multi-resource theories, we study the states of equilibrium of closed systems, known as passive states, and analyse under which circumstances it is possible to extract energy from these states. We show that passivity is energetically unstable, and that, even for closed systems, the only stable states are those with a well-defined temperature.
How the Dirac Sea Idea May Apply to a Spatially-Flat Universe Model (A Brief Review)

The famous Dirac sea idea can be resurrected if one replaces the concept of positive and negative matter mass with positive and negative energy. Utilizing this concept, the perpetually spatially-flat matter-generating FSC model can be shown to be a realistic Milne “empty universe” model. Furthermore, this may be why Rh = ct cosmological models like FSC show an excellent statistical fit with the accumulated data of the Supernova Cosmology Project.
Broadband Band-Absorptive Frequency-Selective Rasorber With a Hybrid 2-D and 3-D Structure

A novel frequency-selective rasorber (FSR) with a broad absorption band is proposed in this letter. The proposed FSR is realized by vertically cascading a two-dimensional (2-D) lossy layer with a 3-D band-stop frequency-selective structure (FSS). The 2-D lossy layer is composed of meandered square loops loaded with lumped resistors, and the 3-D band-stop FSS is constructed by parallel-plate waveguide arrays (PPWAs) stacked along the TE polarization direction (linear polarization perpendicular to the PPW). The band-absorptive FSR exhibits an absorption band (|S11| ≤ –10 dB and |S21| ≤ –10 dB) from 7.85 to 12.85 GHz and a low-pass band (|S21| ≥ –1 dB) up to 3.8 GHz. Its transition efficiency of the transition band (FRap) is 2.1. A prototype is fabricated, and its measured results show that the proposed FSR has a low loss and flat low-pass band, a wide absorption band with high selectivity, and a steep transition band between the low-pass band and absorption band.
Structure and dynamics of concentrated mesoscale vortices in planetary atmospheres

Concentrated vortices are spatially localized structures with nonzero vorticity surrounded by a potential flow. These structures include a broad class of mesoscale vortices, such as dust devils, water vortices, and fire vortices, as well as larger-scale and more intense tornados. From a rather broad class of concentrated mesoscale vortices, dust devils are selected as the simplest and most easily observable structures owing to dust particles that play the role of tracers. The aim of this review is to present the main results of studies of dust devils in the atmospheres of Earth and Mars. In the framework of ideal fluid dynamics, a recently proposed model is discussed that allows describing vortex structures that are fully localized in space. The results of numerical modeling of vortex dynamics and an analytic model of vortex generation in a convectively unstable atmosphere are briefly discussed.
Análise Dinâmica de Vigas Apoiadas em Fundaςão sob a Aςão de Cargas Móveis

A analise de vigas sobre base elastica submetidas a cargas estaticas e dinâmicas tem grande importância na engenharia estrutural e fornece ferramentas uteis para resolver problemas praticos como o projeto de fundacoes e vias ferreas, entre outros. Um caso particularmente importante e o estudo do comportamento dinâmico destes elementos estruturais na presenca de cargas moveis. Apresenta-se neste trabalho a analise de vigas prismaticas de comprimento infinito repousando sobre uma fundacao elastica do tipo Winkler, submetida a acao de cargas moveis e forcas axiais de compressao. Consideram-se cargas concentradas e uniformemente distribuidas em um trecho finito de magnitude constante ou com variacao harmonica. A viga e descrita pela teoria linear de Euler-Bernoulli (teoria classica de vigas) e de Rayleigh (considerando inercia rotacional). A fundacao e descrita por uma lei constitutiva nao-linear com nao-linearidade cubica. Para o caso linear se obtem uma solucao analitica exata usando transformadas duplas de Fourier. Emprega-se tambem o metodo de Galerkin para a analise do problema linear e nao-linear. Para isto, usam-se series de Fourier como funcoes de aproximacao, sendo o problema resolvido analiticamente no dominio do tempo no caso linear e mediante integracao numerica das equacoes de movimento, no caso nao-linear. Apresenta-se no caso linear uma analise parametrica, comparando os resultados obtidos pelo metodo de Galerkin com a solucao exata. Para o caso nao-linear, estuda-se a influencia da nao-linearidade da fundacao, do raio de giracao da secao da viga, da magnitude da forca axial compressiva, da velocidade de deslocamento da carga transversal e da variacao da amplitude da carga harmonica nos deslocamentos da viga.
A novel weak fault signal detection approach for a rolling bearing using variational mode decomposition and phase space parallel factor analysis

Considering the difficulty of fault feature extraction from a rolling bearing under strong background noise, we present a novel approach based on variational mode decomposition (VMD) and phase space parallel factor analysis, for detecting the weak fault signal of a rolling bearing. In this scheme, the VMD method is first adopted to decompose the raw vibration signal into several intrinsic mode components. The selected intrinsic mode function component with maximal kurtosis is subsequently embedded into the high dimensional phase space by phase space reconstruction. Then, the independent components are estimated in the high dimensional phase space by parallel factor analysis. In addition, a new criterion combining kurtosis and feature energy factor (FEF) is proposed for the selection of the time delay and embedding dimension. Finally, the optimal independent component with the largest FEF is selected for envelope spectrum analysis, and the faint fault characteristic frequencies of the vibration signal can be extracted. The feasibility of the proposed scheme is demonstrated through simulation and experimental vibration signals. Results indicate that the proposed method has better capability in detecting a weak fault signal of a rolling bearing, compared with VMD-fast spectral kurtogram and phase space independent component analysis.
Quorum Set Systems for Generalized Resource Allocation Problem

Mutual exclusion (mutex) is fundamental problems in distributed systems in which a resource must be used at most one process at a time when some processes were communicating each other to compete in accessing. Many resource allocations problems have been constructed base on the mutual exclusion problem, and it can be generally formed to problems called (n,m,k,d)-resource allocation and further extended to (n,m,k,di)-resource allocation, i.e, the problem to synchronize accesses on k identical resources among n processes which belong to m groups and each resource can be used by at most di processes of the same group at a time. The generalized resource allocation problem can be solved using a quorum system called (m,k,d)-coterie and (m,k,di)-coterie that satisfies the relaxed safety property of the original mutual exclusion. If quorum based algorithm of mutual exclusion directly adopt to the quorum systems then the massage complexity is the same and the maximum degree of concurrency of the generalized resource allocation problem of di h i=1 is achieved.
Bethe–Salpeter equation for absorption and scattering spectroscopy: implementation in the exciting code

The Bethe–Salpeter equation for the electron–hole correlation function is the state-of-the-art formalism for optical and core spectroscopy in condensed matter. Solutions of this equation yield the full dielectric response, including both the absorption and the inelastic scattering spectra. Here, we present an efficient implementation within the all-electron full-potential code exciting, which employs the linearized augmented plane-wave (L)APW+LO basis set. Being an all-electron code, exciting allows the calculation of optical and core excitations on the same footing. The implementation fully includes the effects of finite momentum transfer which may occur in inelastic x-ray spectroscopy and electron energy-loss spectroscopy. Our implementation does not require the application of the Tamm–Dancoff approximation that is commonly employed in the determination of absorption spectra in condensed matter. The interface with parallel linear-algebra libraries enables the calculation for complex systems. The capability of our implementation to compute, analyze, and interpret the results of different spectroscopic techniques is demonstrated by selected examples of prototypical inorganic and organic semiconductors and insulators.
Research on Remote Sensing Image Target Recognition Based on Deep Convolution Neural Network

Target recognition is an important application in the time of high-resolution remote sensing images. However, the traditional target recognition method has the characteristics of artificial design, and the generalization ability is not strong, which makes it difficult to meet the requirement of the current mass data. Therefore, it is urgent to explore new methods for feature extraction and target recognition and location in remote sensing images. Convolutional neural network in deep learning can extract representative and discriminative multi-level features of typical features from images, so it can be used for multi-target recognition of remote sensing big data in complex scenes. In this study, NWPU VHR-10 data was selected, 50% was used for training, and the remainder was used for verification. The target recognition effects of two kinds of convolutional neural network models, Faster R-CNN and SSD, were studied and compared, and the mean average precision (mAP) was used for evaluation. The evaluation results show that the Faster R-CNN has three categories with an accuracy of more than 80%, and the SSD has seven categories with an accuracy of more than 80%, all of which show good results. The SSD model is particularly prominent in running time and recognition results, which proves convolutional neural networks have broad application prospects in the target recognition of remote sensing image data.
PRN-21 Carrier Phase Perturbations Observed by WAAS

PRN-21 experienced numerous periods of anomalous or degraded performance over the past three years where the Wide Area Augmentation System (WAAS) set this satellite Not Monitored or increased the User Differential Range Error (UDRE). Setting the satellite to Not Monitored or to a higher UDRE value limits the utility of this satellite in the WAAS service. Investigation of these events indicated PRN-21 exhibited carrier range perturbations that sometimes resulted in receiver subframe parity failures, adjustments of L1 and L2 carrier of approximately half cycle over a few seconds, or complete loss of carrier tracking. These subframe and carrier tracking anomalies were investigated and were also observed in other receivers besides those used in the WAAS network. These anomalous PRN-21 events have been occurring approximately twice per month and are observed and tracked by normal WAAS system monitoring. PRN-21 is a GPS Block II-R satellite that was launched on March 31, 2003. Other GPS satellites exhibit similar carrier phase behavior but they typically are GPS Block II-A satellites and events do not occur with this frequency. This paper characterizes the events occurring with PRN-21 and shows that PRN-21 exhibits this anomalous behavior more frequently than other GPS satellites. It is anticipated this paper will be of interest to others that perform precision processing of GPS data as well as those that monitor GPS satellite performance.