Miracle-dz/UniFAR-FTUs huggingface dataset:
The spontaneous breaking of axisymmetry in shallow rotating flows

We show that the axial symmetry of a shallow rotating flow is spontaneously broken in the absence of an externally forced velocity gradient. It is caused by an instability excited by the gradients that arise from the axisymmetric counter-rotating vortices. The experimental setup consists of an electrolyte poured into a cylindrical container with radius R and height h and subject to electromagnetic forcing caused by an axial magnetic field and a radial current (J) leading to an azimuthal rotation Vθ. The flow motion is considered to be two-dimensional at large aspect ratio (R/h) and low Reynolds number, Re = Vθh/ν, where ν is the kinematic viscosity. At a moderate aspect ratio, we record the existence of an axisymmetric vortex at the edge caused by the no-slip boundary condition at the walls. When Re is increased by changing h or J, the flow becomes unstable at the radial position where gradients exist due to the edge vortices at a critical Reynolds number of about 220. The most unstable mode of this nonaxisymmetric instability is found to be m = 1 followed by m = 2 and other higher mode numbers. Using perturbation theory, we found that two counter-rotating vortices that are in azimuthal motion are unstable when subject to nonaxisymmetric perturbations with the onset of low azimuthal mode numbers in agreement with the experiment. We conclude that the axial symmetry breaking in shallow rotating flows occurs at relatively low Reynolds numbers caused by the gradients generated by the vortices in the height-radial plane.We show that the axial symmetry of a shallow rotating flow is spontaneously broken in the absence of an externally forced velocity gradient. It is caused by an instability excited by the gradients that arise from the axisymmetric counter-rotating vortices. The experimental setup consists of an electrolyte poured into a cylindrical container with radius R and height h and subject to electromagnetic forcing caused by an axial magnetic field and a radial current (J) leading to an azimuthal rotation Vθ. The flow motion is considered to be two-dimensional at large aspect ratio (R/h) and low Reynolds number, Re = Vθh/ν, where ν is the kinematic viscosity. At a moderate aspect ratio, we record the existence of an axisymmetric vortex at the edge caused by the no-slip boundary condition at the walls. When Re is increased by changing h or J, the flow becomes unstable at the radial position where gradients exist due to the edge vortices at a critical Reynolds number of about 220. The most unstable mode of this nonax.
Pulse-coupled neural networks

A pulse-coupled neural network is shown to contain invariant spatial information in the phase structure of the output pulse trains. Two time scales are identified. On the fast time scale the linking produces dynamic, periodic, fringe-like traveling waves. The slow time scale is set by the pulse generator, and on that scale the image is segmented into multi-neuron time-synchronous groups. These groups, by the same linking mechanism, can form periodic pulse structures whose relative phases encode the location of the groups with respect to one another. The time signals are a unique, object-specific and roughly invariant time signature for their corresponding input spatial image or distribution. The details of the model are discussed, giving the basic linking field model, extensions, generation of time series in the limit of very weak linking, invariances from the symmetries of the receptive fields, time scales, waves, and signatures. Multi-rule logical systems are shown to exist on single neurons. Adaptation is discussed. Hardware implementations, optical and electronic, are reviewed. The conjugate basic problem of transforming a time signal into a spatial distribution is discussed.
Human Knee Inverse Dynamics Model of Vertical Jump Exercise

This work deals with the dynamics of the human knee during vertical jump exercise. The focus is on the joint forces necessary to produce the jump and to dissipate energy during landing. A two-dimensional (2D) sagittal plane, inverse dynamics human leg model is developed. This model uses data from a motion capture system and force plates in order to predict knee and hip joint forces during the vertical jump exercise. The model consists of three bony structures femur, tibia, and patella, ligament structures to include both cruciate and collateral ligaments, and knee joint muscles. The inverse dynamics model is solved using optimization in order to predict joint forces during this exercise. matlab software package is used for the optimization computations. Results are compared with data available in the literature. This work provides insight regarding contact forces and ligaments forces, muscle forces, and knee and hip contact forces in the vertical jump exercise.
Tropical Forest Height Retrieval Based on P-Band Multibaseline SAR Data

In this letter, we present an experimental assessment of vegetation height retrieval in tropical forests based on P-band synthetic aperture radar (SAR) acquisitions. Two approaches are implemented and compared: 1) parametric height estimation by minimizing the least-square problem between random volume over ground (RVoG) model predictions and multibaseline SAR data and 2) thresholding the vertical backscattering profiles that are focused by SAR Beam-forming tomography. The data set under analysis is from the ESA AfriSAR campaign that was flown over Gabon in 2016. Results show that at a resolution of $25~\text{m}\times 25~\text{m}$ , which corresponds to about 80 independent looks, both of the two approaches are able to retrieve forest height to within an accuracy of about 3 m or better over the interval of forest height between 30 and 50 m when compared to Light Detection and Ranging (LiDAR) measurements.
Principal Components Analysis of Discrete Datasets

We propose a Gaussian copula based method to perform principal component analysis for discrete data. By assuming the data are from a discrete distributions in the Gaussian copula family, we can consider the discrete random vectors are generated from a latent multivariate normal random vector. So we first obtain an estimate of the correlation matrix of latent multivariate normal distribution, then we use the estimated latent correlation matrix to get the estimates of principal components. We also focus on the case when we have categorical sequence data with multinomial marginal distribution. In this case the marginal distribution is not univariate and thus the usual Gaussian copula does not fit here. The optimal mapping method is proposed to convert the original data with multivariate discrete marginals to the mapped data with univariate marginals. Then the usual Gaussian copula can be used to model the mapped data, and we apply the discrete principal component analysis to the mapped data. The senators’ voting data was used in the experiment as an example. Finally, we also propose a matrix Gaussian copula method to deal with data with multivariate marginals. It can be considered as an extension of Gaussian copula, and we use the latent correlation matrix in the matrix Gaussian copula to obtain the principal components.
Structural softening, mesh dependence, and regularisation in non‐associated plastic flow

A severe dependence of numerical simulations on the mesh density is usually attributed to the presence of strain softening in the constitutive relation. However, other material instabilities, like non‐associated plastic flow, can also cause mesh sensitivity. Indeed, loss of ellipticity in quasi‐static analyses is the fundamental cause of the observed mesh dependence. It has been known since long that non‐associated plastic flow can cause loss of ellipticity, but the consequence for mesh sensitivity, and subsequently, for the difficulty of the equilibrium‐finding iterative procedure to converge have remained largely unnoticed. We first demonstrate at the hand of a biaxial test structural softening and a marked mesh dependence for an ideally plastic material equipped with a non‐associated flow rule. The phenomena are then analysed in depth using an infinitely long shear layer. Finally, it is shown that the mesh effect disappears when the standard continuum model is replaced by a Cosserat continuum, a well‐known regularisation method for strain‐softening constitutive relations.
Raman study of pyroelectric and injected charge induced fields in PLZT 8/65/35 ceramics

Abstract Electric fields of different nature induced in lanthanum doped lead zirconate-titanate (PLZT) ceramics were studied by confocal Raman microscopy. Temperature dependence of the pyroelectric field was determined and the value of pyroelectric coefficient was estimated. An appearance of additional line in Raman spectrum of PLZT after e-beam irradiation was revealed and its spatial distribution was studied. The origin of this spectral line was discussed in terms of defects formation and phase transitions.
Introduction to Semi-Supervised Learning

Including the historical background and recent advances in the field as well as theoretical perspectives and real-world applications, this book outlines a systematic framework for implementing semi-supervised learning methods. It provides a toolbox on semi-supervised learning algorithms, presenting illustrations and examples of each algorithm. The book defines and distinguishes supervised learning, unsupervised learning, semi-supervised learning, and other relevant learning tasks. It discusses important semi-supervised learning models, including generative models for semi-supervised learning, semi-supervised support vector machines, and graph-based semi-supervised learning methods.
A new additive decomposition of velocity gradient

To avoid the infinitesimal rotation nature of the Cauchy-Stokes decomposition of velocity gradient, the letter proposes an new additive decomposition in which one part is a SO(3) rotation tensor Q = exp W.To avoid the infinitesimal rotation nature of the Cauchy-Stokes decomposition of velocity gradient, the letter proposes an new additive decomposition in which one part is a SO(3) rotation tensor Q = exp W.
Connection Density Maximization of Narrowband IoT Systems With NOMA

Narrowband Internet of Things (NB-IoT) provides energy-efficient communications with extended coverage for the low data rate IoT devices. In this paper, we propose a power-domain non-orthogonal multiple access (NOMA) scheme for the NB-IoT systems to enhance the connection density by allowing multiple IoT devices to simultaneously access one subcarrier. We consider both single-tone and multi-tone transmission modes of the NB-IoT systems, where each device can access a single subcarrier or a bond of contiguous subcarriers, respectively. We formulate joint subcarrier and power allocation problems for both transmission modes to maximize the connection density while taking the quality of service requirements and the transmit power constraints of IoT devices into account. We solve the single-tone nonconvex mixed integer programming problem by transforming it into a mixed integer linear programming problem to obtain the optimal solution. The multi-tone problem is solved by using the difference of convex programming approach to obtain a close-to-optimal solution. We also propose low-complexity heuristic algorithms to solve both problems in a suboptimal manner. The simulations results show that our proposed scheme increases the connection density of NB-IoT systems by 87% in the single-tone mode and by 24% in the multi-tone mode compared to orthogonal multiple access.
Thermally Beam-Direction- and Beamwidth-Switchable Monopole Antenna Using Origami Reflectors With Smart Shape Memory Polymer Hinges

This letter presents a thermally reconfigurable antenna with beam-direction- and beamwidth-switching capability using origami reflectors with smart shape memory polymer (SMP) hinges. The proposed antenna consists of a single monopole antenna with four origami reflectors. We employ SMP hinges to actuate the origami reflectors. When all origami reflectors are unfolded on the ground plane (Mode I), the monopole antenna exhibits omnidirectional radiation because the reflectors operate as dummies. When two origami reflectors are folded perpendicular to the ground plane, forming a corner reflector (Mode II), the proposed antenna operates as a directional antenna. Beam direction can be switched to 45°, 135°, 225°, and 315° by actuating various origami reflector pairs, with increased peak gain from 4.5 dBi (Mode I) to 11 dBi (Mode II). When one origami reflector is folded perpendicular to the ground plane (Mode III), the 3 dB beamwidth increases from 52° (Mode II) to 140° (Mode III). Beam direction of Mode III can also be switched through 0°, 90°, 180°, and 270° by actuating each origami reflector. The proposed antenna performance was successfully demonstrated from electromagnetic simulation and measurement.
Categories of Residuated Lattices

We present dual variants of two algebraic constructions of certain classes of residuated lattices: The Galatos-Raftery construction of Sugihara monoids and their bounded expansions, and the Aguzzoli-Flaminio-Ugolini quadruples construction of srDL-algebras. Our dual presentation of these constructions is facilitated by both new algebraic results, and new duality-theoretic tools. On the algebraic front, we provide a complete description of implications among nontrivial distribution properties in the context of lattice-ordered structures equipped with a residuated binary operation. We also offer some new results about forbidden configurations in lattices endowed with an order-reversing involution. On the duality-theoretic front, we present new results on extended Priestley duality in which the ternary relation dualizing a residuated multiplication may be viewed as the graph of a partial function. We also present a new Esakia-like duality for Sugihara monoids in the spirit of Dunn’s binary Kripke-style semantics for the relevance logic R-mingle.
Stochastic optimization problems : decomposition and coordination under risk

Nous considerons des problemes d'optimisation stochastique et de theorie des jeux avec des mesures de risque. Dans une premiere partie, nous mettons l'accent sur la coherence temporelle. Nous commencons par prouver une equivalence entre coherence temporelle et l'existence d'une formule imbriquee pour des fonctions. Motives par des exemples bien connus dans les mesures de risque, nous etudions trois classes de fonctions: les fonctions invariantes par translation, les transformees de Fenchel-Moreau et les fonctions supremum. Ensuite, nous etendons le concept de coherence temporelle a la coherence entre joueurs, en remplacant le temps sequentiel par un ensemble non ordonne et les fonctions par des relations binaires. Enfin, nous montrons comment la coherence entre joueurs est liee a des formes de decomposition sequentielles et paralleles en optimisation. Dans une seconde partie, nous etudions l'impact des mesures de risque sur la multiplicite des equilibres dans les problemes de jeux dynamiques dans les marches complets et incomplets. Nous concevons un exemple ou l'introduction de mesures de risque conduit a l'existence de trois equilibres au lieu d'un dans le cas risque neutre. Nous analysons la capacite de deux algorithmes differents a trouver les differents equilibres. Nous discutons des liens entre la coherence des joueurs et les problemes d'equilibre dans les jeux. Dans une troisieme partie, nous etudions l'optimisation robuste pour l'apprentissage automatique. En utilisant des mesures de risque convexes, nous fournissons un cadre unifie et proposons un algorithme adapte couvrant trois ensembles d'ensembles d'ambiguite etudies dans la litterature
Citation Structure: An Analysis of the Literature Cited in the Journal of Applied Communications from 1997 - 2006

The Journal of Applied Communications ( JAC) is a primary outlet of agricultural communications publishing and research dissemination. The purpose of this study was to assess ten years of JAC to determine literature cited. The study used a quantitative content analysis design. Analyzed in the study were 91 research and/or professional articles with research methodologies published from 1997 through 2006. There were 1,732 cited literature works identified in the journal. The average number of citations per article was approximately 19. Cited works from identified premier agricultural education journals were tracked for citation frequencies, in terms of author(s) and year of publication. A total of 143 references were made to journals identified as premier. The most frequently cited journals were from journalism, communications, and mass communications sources, including JAC. Additional cited works are defined. Citation analysis indicates that JAC relies heavily on books, journals, conference proceedings, and other literacy works outside agricultural communications. JAC does not exhibit compactness, indicating that it reaches past its citation boundaries and into interrelated areas of other disciplines. However, it does exhibit weak self-identity meaning it does little to build upon research previously cited in JAC.
Modèle spatio-temporel de dépôt de gadolinium dans les noyaux gris centraux après IRM cérébrales répétées avec produit de contraste linéaire

Droits d’auteur L'Université de Lausanne attire expressément l'attention des utilisateurs sur le fait que tous les documents publiés dans l'Archive SERVAL sont protégés par le droit d'auteur, conformément à la loi fédérale sur le droit d'auteur et les droits voisins (LDA). A ce titre, il est indispensable d'obtenir le consentement préalable de l'auteur et/ou de l’éditeur avant toute utilisation d'une oeuvre ou d'une partie d'une oeuvre ne relevant pas d'une utilisation à des fins personnelles au sens de la LDA (art. 19, al. 1 lettre a). A défaut, tout contrevenant s'expose aux sanctions prévues par cette loi. Nous déclinons toute responsabilité en la matière.
Miniaturized Circularly Polarized Doppler Radar for Human Vital Sign Detection

In this paper, a miniaturized circularly polarized (CP) continuous wave Doppler radar system operating at 2.4 GHz is presented. The radar front end consists of one left-handed CP (LHCP) antenna and one right-handed CP (RHCP) antenna, which share a single patch antenna aperture. Orthogonal polarization is achieved through a modified ring-shaped quadrature hybrid coupler (QHC), and the resulting isolation between the two CP antennas is better than 30 dB. With 0 dBm input power to the transmitting antenna, the proposed radar system can accurately detect heartbeat and respiration movements of human test subjects under 1 m and over a wide angular range. The single dual CP antenna achieves 280% size reduction compared to a traditional two linear polarization patch antenna array with the same isolation level.
Introductory Chapter: The Path to the Future

The idea to use light for communication purposes was envisioned many years ago. However, the origins of optical communications trace back to 1966 when Charles Kao suggested the possibility that low‐loss optical fibers could be competitive with coaxial cable and metal waveguides for telecommunication applications. However, it was not until 1970 when Corning Glass Works announced an optical fiber loss less than the benchmark level of 10 dB/km that commercial applications began to be realized. Quickly, the purifying process was refined, and in the late 1980s, optical fibers with an attenuation of 0.2 dB/km were manufactured and commercialized. Surely, our society was shaped by the concepts developed by Charles Kao in the 1960s. In recognition of his pioneering work, in 2009, Charles Kao was awarded the Nobel Prize in Physics along with Willard S. Boyle and George E. Smith.
Statistical Modelling by Exponential Families

This book is a readable, digestible introduction to exponential families, encompassing statistical models based on the most useful distributions in statistical theory, including the normal, gamma, binomial, Poisson, and negative binomial. Strongly motivated by applications, it presents the essential theory and then demonstrates the theory's practical potential by connecting it with developments in areas like item response analysis, social network models, conditional independence and latent variable structures, and point process models. Extensions to incomplete data models and generalized linear models are also included. In addition, the author gives a concise account of the philosophy of Per Martin-Lof in order to connect statistical modelling with ideas in statistical physics, including Boltzmann's law. Written for graduate students and researchers with a background in basic statistical inference, the book includes a vast set of examples demonstrating models for applications and exercises embedded within the text as well as at the ends of chapters.
Design of physical user–robot interactions for model identification of soft actuators on exoskeleton robots

Recent breakthroughs in wearable robots, such as exoskeleton robots with soft actuators and soft exosuits, have enabled the use of safe and comfortable movement assistance. However, modeling and identification methods for soft actuators used in wearable robots have yet to be sufficiently explored. In this study, we propose a novel approach for obtaining accurate soft actuator models through the design of physical user–robot interactions for wearable robots, in which the user applies external forces to the robot. To obtain an accurate soft actuator model from the limited amount of data acquired through an interaction, we leverage an active learning framework based on Gaussian process regression. We conducted experiments using a two-degree-of-freedom upper-limb exoskeleton robot with four pneumatic artificial muscles (PAMs). Experimental results showed that physical interactions between the exoskeleton robot and the user were successfully designed to allow PAM models to be identified. Furthermore, we found that data acquired through an interaction could result in more accurate soft actuator models for the exoskeleton robots than data acquired without a physical interaction between the exoskeleton robot and the user.
Reconstruction of Sparse Propagation Environment With Complexity Reduced OMP Algorithm

Effective delay resolution of propagation paths recovery can be controlled by oversampling used at the delay estimation stage of orthogonal matching pursuit (OMP) method. Unfortunately, a finer resolution increases the number of inner products to be computed there. In order to reduce their quantity, a modification called successive delay approximation (SDA) is proposed. The SDA selects an approximated path delay calculating only two extra inner products for each subsequent doubling of the oversampling ratio. The proposed solution is numerically efficient without significant transmission quality loss that has been proven in the simulations.
Molecular dynamics modelling of the mechanics of cells

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