Miracle-dz/UniFAR-FTUs huggingface dataset:
TIVA-KG: A Multimodal Knowledge Graph with Text, Image, Video and Audio

Knowledge graphs serve as a powerful tool to boost model performances for various applications covering computer vision, natural language processing, multimedia data mining, etc. The process of knowledge acquisition for human is multimodal in essence, covering text, image, video and audio modalities. However, existing multimodal knowledge graphs fail to cover all these four elements simultaneously, severely limiting their expressive powers in performance improvement for downstream tasks. In this paper, we propose TIVA-KG, a multimodal Knowledge Graph covering Text, Image, Video and Audio, which can benefit various downstream tasks. Our proposed TIVA-KG has two significant advantages over existing knowledge graphs in i) coverage of up to four modalities including text, image, video, audio, and ii) capability of triplet grounding which grounds multimodal relations to triples instead of entities. We further design a Quadruple Embedding Baseline (QEB) model to validate the necessity and efficacy of considering four modalities in KG. We conduct extensive experiments to test the proposed TIVA-KG with various knowledge graph representation approaches over link prediction task, demonstrating the benefits and necessity of introducing multiple modalities and triplet grounding. TIVA-KG is expected to promote further research on mining multimodal knowledge graph as well as the relevant downstream tasks in the community. TIVA-KG is now available at our website: http://mn.cs. tsinghua.edu. cn/tivakg.
Modelling distortions in seroprevalence data using change-point fractional polynomials

This paper shows how to model seroprevalence data using change-point fractional polynomials (FPs). The inclusion of a change point in the FP framework allows to detect distortions arising from common (often untestable) assumptions made in the estimation of the age-specific prevalence and force of infection from cross-sectional data. The method is motivated using seroprevalence data on the parvovirus B19 and the varicella zoster virus in Belgium.
Resonance phenomena of log-periodic antennas: characteristic-mode analysis

The method of characteristic modes is implemented in the form of a general-purpose computer program based on an established moment-method program using piecewise sinusoids. Application of the method to the log-periodic dipole antenna (LPDA) yields characteristic modes that are insensitive to changes in moment-method segmentation and are revealing with regard to parasitic resonance phenomena. A study of the modes on the LPDAs shows that the asymmetry resonance is dominated by a mode that is not restricted to one cell, although the single-resonant-cell postulate remains a good first-order explanation. On the other hand, the symmetric termination resonance is shown to involve more than one mode. A numerical study of various antenna deformations shows that only length extensions cause strong asymmetry resonances. The E-plane array is analyzed, and the results are shown to compare favorably with experiment. >
Flow between rotating finite disks with a closed end condition studied by heterodyne photon-correlation

We have investigated experimentally the swirling flow between a stationary and a rotating disk with fixed closed end. In order to perform velocimetry measurements we implemented a heterodyne photon-correlation setup and obtained the three components of the velocity field at different positions along the gap between the disks. We compared the results for two different Reynolds numbers with a numerical solution of the similarity equation, to investigate the relation between the finite and infinite disk solution, theoretically studied by Brady & Durlofsky (1987). For the measurements performed at $\hbox{\it Re}$ below the critical Reynolds number $\hbox{\it Re}_C\,{=}\,80$, we found that the two solutions agree very well near the axis of rotation. Above $\hbox{\it Re}_C$ we found that this quantitative agreement no longer holds, but the flow qualitatively resembles the Batchelor solution, with two boundary layers and a core rotating as a solid body. Our results validate the theoretical prediction for closed-end finite disk flow.
Occlusion-free 3D recovery using mirror images

Concerns 3D reconstruction from the 2D real image formed in a camera when mirrors are used so that both the object and reflections of it are viewed by the camera. The mirrors generate symmetric relations between direct images and mirror images. Correspondences between the direct image and the mirror images are found, and the 3D shape is reconstructed by a plane symmetry recovery method using the vanishing point. The use of several mirrors eliminates the occlusion that occurs when only one mirror is used. <<ETX>>
Influence of strain relaxation on the optical properties of InGaN/GaN multiple quantum well nanorods

Optical investigation has been carried out on InGaN/GaN nanorod structures with different indium compositions, fabricated from InGaN/GaN multiple quantum well (MQW) epitaxial wafers using a self-organized nickel nano-mask and subsequent dry etching techniques. In comparison with the as-grown InGaN/GaN MQWs, the internal quantum efficiencies of the nanorods are significantly improved, in particular, for the green InGaN/GaN nanorods with a high indium composition, the internal quantum efficiency is enhanced by a factor of 8, much larger than the enhancement factor of 3.4 for the blue InGaN/GaN nanorods. X-ray reciprocal space mapping (RSM) measurements have been performed in order to quantitatively evaluate the stain relaxation in the nanorods, demonstrating that the majority of strain in InGaN/GaN MQWs can be relaxed as a result of fabrication into nanorods. The excitation-power-dependent photoluminescence measurements have also clearly shown that a significant reduction in the strain-induced quantum confined stark effect has occurred to the nanorod structures.
"Fast maximum likelihood joint estimation of frequency and frequency rate"

A Fast Maximum Likelihood Algorithm for the Joint estimation of the Frequency and Frequency rate of a sinusoid in Gaussian white noise is presented here. The novelty of this algorithm is the use of Newton's method for finding the zero of a function to determine the maximum of the log-likelihood function. The rate of convergence of Newton's method is extremely fast. Simulation of the algorithm shows that the RMSEs for frequency and frequency-rate are practically equal to the Cramer-Rao bound for allSNR \geq 15dB.
A use of complex probabilities in the theory of stochastic processes

ABSTRACT The exponential distribution is very important in the theory of stochastic processes with discrete states in continuous time. A. K. Erlang suggested a method of extending to other distributions methods that apply in the first instance only to exponential distributions. His idea is generalized to cover all distributions with rational Laplace transforms; this involves the formal use of complex transition probabilities. Properties of the method are considered.
Analysis of Transverse Vibration of Antenna Structure Resonator Using Bernoulli–Euler Beam Theory and Quantum Mechanical Examination of Its Quantized Displacement

We analytically investigated the vibration of a macroscopic antenna structure resonator of 10.7 µm length showing a quantized displacement at 110 mK using Bernoulli–Euler beam theory. According to our calculations on the vibrational displacement and mode of the resonator, the vibration mode increased step-by-step from the 1st to 10th mode and then repeated again from the 1st to 10th mode. We found the 10th mode of the resonator at 1.592 GHz when using every paddle length of 490 nm, which is 10 nm shorter than that of a usual antenna structure resonator, existed near a frequency of 1.49 GHz at which the quantized displacement was observed. In the 10th mode of the antenna structure resonator at 1.592 GHz, the displacement of the central beam was so extensively damped that its mechanical energy may be considered to be zero. Therefore, the mechanical energy of the antenna structure resonator could be approximately calculated from the displacement of forty paddles regarded as cantilever beams. We could explain the quantized displacement of the antenna structure resonator using the equivalent mass of a harmonic oscillator, to which the antenna structure resonator was approximately equivalent in mechanical energy, and the quantization of a harmonic oscillator in a textbook on quantum mechanics if the wave function of quantum mechanics can be applied to this harmonic oscillator.
Modelling shear flows with smoothed particle hydrodynamics and grid‐based methods

Given the importance of shear flows for astrophysical gas dynamics, we study the evolution of the Kelvin-Helmholtz instability (KHI) analytically and numerically. We derive the dispersion relation for the two-dimensional KHI including viscous dissipation. The resulting expression for the growth rate is then used to estimate the intrinsic viscosity of four numerical schemes depending on code-specific as well as on physical parameters. Our set of numerical schemes includes the Tree-SPH code VINE, an alternative smoothed particle hydrodynamics (SPH) formulation developed by Price and the finite-volume grid codes FLASH and PLUTO. In the first part, we explicitly demonstrate the effect of dissipation-inhibiting mechanisms such as the Balsara viscosity on the evolution of the KHI. With VINE, increasing density contrasts lead to a continuously increasing suppression of the KHI (with complete suppression from a contrast of 6:1 or higher). The alternative SPH formulation including an artificial thermal conductivity reproduces the analytically expected growth rates up to a density contrast of 10: 1. The second part addresses the shear flow evolution with FLASH and PLUTO. Both codes result in a consistent non-viscous evolution (in the equal as well as in the different density case) in agreement with the analytical prediction. The viscous evolution studied with FLASH shows minor deviations from the analytical prediction.
Recent progress of SOI-based photonic devices

SOI (Silicon on Insulator) based photonic devices, including stimulated emission from Si diode, RCE (Resonant Cavity Enhanced) photodiode with quantum structure, MOS (Metal Oxide Semiconductor) optical modulator with high frequency, SOI optical matrix switch and wavelength tunable filter are reviewed in the paper. The emphasis will be played on our recent results of SOI-based thermo-optic waveguide matrix switch with low insertion loss and fast response. A folding re-arrangeable non-blocking 4×4 matrix switch with total internal reflection (TIR) mirrors and a first blocking 16×16 matrix were fabricated on SOI wafer. The extinction ratio and the crosstalk are better. The insertion loss and the polarization dependent loss (PDL) at 1.55 μm increase slightly with longer device length and more bend and intersecting waveguides. The insertion losses are expected to decrease 2~3 dB when anti-reflection films are added in the ends of the devices. The rise and fall times of the devices are 2.1 μs and 2.3 μs, respectively.
A finite volume–multigrid method for flow simulation on stratified porous media on curvilinear co‐ordinate systems

This paper presents a numerical study of infiltration processes on stratified porous media. The study is carried out to examine the performance of a finite volume method on problems with discontinuous solutions due to the transmission conditions in the interfaces. To discretize the problem, a curvilinear co‐ordinate system is used. This permits matching the interface with the boundary of the control volumes that interchange fluxes between layers. The use of the multigrid algorithm for the resulting systems of equations allows problems involving a large number of nodes with low computational cost to be solved. Finally, some numerical experiments, which show the capillary barrier behaviour depending on the material used for the different layers and the geometric design of the interface, are presented. Copyright © 2001 John Wiley & Sons, Ltd.
Conservation Laws, Numerical Schemes and Control Strategies for Sedimentation and Wastewater Treatment

A consistent theme throughout this thesis is quasilinear partial differential equations (PDEs) appearing in one-dimensional models of sedimentation for solid-liquid separation of suspensions. We mainly focus on continuous sedimentation in so-called clarifier-thickeners (CTs), which are found in mineral processing and wastewater treatment. In addition to complications with shocks and non-unique solutions that are standard for quasilinear first-order PDEs, the considered CT models offer challenges such as spatially discontinuous fluxes and strongly-degenerate diffusion terms. We are primarily concerned with numerical methods for two CT models: one previously published scalar PDE model relying on the assumption that all suspended solids have the same settling properties, and one system of strongly coupled PDEs that accounts for solids with non-homogeneous settleability. A method of Godunov type is proposed for the scalar model. This method has been well received by the wastewater community and it is implemented both on benchmark simulation platforms and in commercial software. During the development of numerical schemes for the second model, we encounter a hyperbolic system with a delicate feature: a nonlinear contact field. Generalising the problem setting to a family of systems, also containing the celebrated Aw-Rascle-Zhang traffic flow model, we construct a novel random sampling scheme to capture discontinuities with jumps along curves in such fields. Convergence to weak solutions of the hyperbolic system is proved for that scheme. The research presented also covers steady-state analyses and design of control strategies for stand-alone CTs and for a wastewater treatment plant with a biological reactor preceding the sedimentation process. The plant-wide models of interest are given as systems of ordinary differential equations for the reactor coupled to some PDEs for the CT.
Auxiliary Variables in Mixture Modeling: Three-Step Approaches Using Mplus

This article discusses alternatives to single-step mixture modeling. A 3-step method for latent class predictor variables is studied in several different settings, including latent class analysis, latent transition analysis, and growth mixture modeling. It is explored under violations of its assumptions such as with direct effects from predictors to latent class indicators. The 3-step method is also considered for distal variables. The Lanza, Tan, and Bray (2013) method for distal variables is studied under several conditions including violations of its assumptions. Standard errors are also developed for the Lanza method because these were not given in Lanza et al. (2013).
What Do Networks Have to Do with Climate

The study of networks has recently exploded into a major research tool in many areas of science. The discovery of “small world” and scale-free networks has led to many new insights about the collective behavior of a large number of interacting agents and complex systems. Here we introduce the basic ideas behind networks, as well as some initial applications of networks to the climate system. Our results suggest that the climate system exhibits aspects of small-world networks as well as scale-free networks, with supernodes corresponding to major teleconnection patterns. This result suggests that the organization of teleconnections may play a role in the stability of the climate system. In addition, preliminary work suggests that temporal changes in the network's architecture may be used to identify signatures of global change. These and other applications suggest that networks provide a new tool for investigating and reconstructing climate dynamics from both models and observations.
A high‐order accurate particle‐in‐cell method

We propose the use of high‐order weighted essentially non‐oscillatory interpolation and moving‐least‐squares approximation schemes alongside high‐order time integration to enable high‐order accurate particle‐in‐cell methods. The key insight is to view the unstructured set of particles as the underlying representation of the continuous fields; the grid used to evaluate integro–differential coupling terms is purely auxiliary. We also include a novel regularization term to avoid the accumulation of noise in the particle samples without harming the convergence rate. We include numerical examples for several model problems: advection–diffusion, shallow water, and incompressible Navier–Stokes in vorticity formulation. The implementation demonstrates fourth‐order convergence, shows very low numerical dissipation, and is competitive with high‐order Eulerian schemes. Copyright © 2012 John Wiley & Sons, Ltd.
Progress in the design of a superconducting toroidal magnet for the ATLAS detector on LHC

The toroidal system consists of three air core superconducting toroids. The barrel toroid covers the central region over a length of 26 m with an inner bore of 9.4 m and an outer diameter of 19.5 m. The two end cap toroids are inserted in the barrel at each end over a length of 5.6 m with an inner bore of 1.26 m. Each toroid consists of eight fiat coils assembled around the beam axis and carrying 3 MAt each. The present paper describes the barrel toroid. Features of the design which are presented include the electromagnetic design, field and forces calculations, the basic concept of indirectly cooled aluminium conductor and monolithic fully impregnated winding, the description of the alu-alloy mechanical structure, the thermal analysis and the quench protection. Cryogenics principles, cryostat and toroid assembly procedures are summarized. Unsymmetric loadings, fault sensing and stability are discussed, in relation with the requirements of transparency.
On stationarity and ergodicity of the bilinear model with applications to GARCH models

We establish sufficient conditions for the bilinear time‐series model to be strictly stationary and ergodic in terms of its associated Lyapunov exponent. In two special cases, we verify that the conditions are also necessary. We then use these results to give necessary and sufficient conditions for stationarity of specific generalized autoregressive conditionally heteroskedastic (GARCH) models which can be written as a bilinear model, including linear GARCH, Power GARCH, EGARCH among others. These results generalize the ones found in the studies of, among others, Bougerol and Picard [Journal of Econometrics 52 (1992) 115], Duan [Journal of Econometrics 79 (1997) 97] and Nelson [Econometric Theory 6 (1990) 318]. In many cases, the conditions are weaker than the ones found elsewhere in the literature.
Robust Statistical Modeling Using the t Distribution

Abstract The t distribution provides a useful extension of the normal for statistical modeling of data sets involving errors with longer-than-normal tails. An analytical strategy based on maximum likelihood for a general model with multivariate t errors is suggested and applied to a variety of problems, including linear and nonlinear regression, robust estimation of the mean and covariance matrix with missing data, unbalanced multivariate repeated-measures data, multivariate modeling of pedigree data, and multivariate nonlinear regression. The degrees of freedom parameter of the t distribution provides a convenient dimension for achieving robust statistical inference, with moderate increases in computational complexity for many models. Estimation of precision from asymptotic theory and the bootstrap is discussed, and graphical methods for checking the appropriateness of the t distribution are presented.
Kernel Conditional Quantile Estimation for Stationary Processes with Application to Conditional Value-at-Risk

The paper considers kernel estimation of conditional quantiles for both short-range and long-range-dependent processes. Under mild regularity conditions, we obtain Bahadur representations and central limit theorems for kernel quantile estimates of those processes. Our theory is applicable to many price processes of assets in finance. In particular, we present an asymptotic theory for kernel estimates of the value-at-risk (VaR) of the market value of an asset conditional on the historical information or a state process. The results are assessed based on a small simulation and are applied to AT&T monthly returns. Copyright The Author 2007. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org, Oxford University Press.
The influence of Hall currents, plasma viscosity and electron inertia on magnetic reconnection solutions

This thesis examines magnetic reconnection in the solar corona. Magnetic reconnection is the only mechanism which allows the magnetic topology of magnetized plasmas to be changed. Many of the dynamic processes in the Sun's atmosphere are believed to be driven by magnetic reconnection and studying the behaviour of such phenomena is a key step to understanding the reconnection mechanism. In Chapters 1 to 3, we discuss the physical and mathematical framework on which current magnetohydrodynamic reconnection models are based. The aim of the thesis is to investigate theoretical models of magnetic reconnection using variety of analytic and numerical techniques within the theoretical frame work of magnetohydrodynamics (MHD). In Chapter 4 we use a line-tied X-point collapse model for compressible plasmas to investigate the role of viscosity on the energy release mechanism. This model also provides the basis for the investigation of Chapter 5 which explores the impact of Hall currents in the transient X-point energy dissipation. Chapter 6 is concerned with how reconnection is modified in the presence of generalized Ohm's law which includes both Hall current and electron inertia contributions. In contrast to the “closed” X-point collapse geometry adopted for compressible plasmas previously, we find it more convenient to explore this problem using an “open” incompressible geometry in which plasma is continually entering and exiting the reconnection region. Specially, we find the scaling of the Hall-MHD system size analytically, rather than numerically as in the X-point problem of Chapter 5. Chapter 7 summarizes the results of investigations in Chapters 4, 5 and 6.
Incremental gain analysis of linear systems with bounded controls and its application to the anti-windup problem

This paper presents an approach to estimating the L/sub 2/ incremental gain of piecewise linear systems. Storage functions satisfying a dissipation inequality are used to derive a set of linear matrix inequalities (LMIs) to provide a bound. The application of the results to the anti-windup problem is illustrated by examples.
Measurement of magnetic fields in axial field motors

Measurements of the magnetic field in three axial field brushless DC motors are described. Three different magnetic materials are used in these motors. A closed-form analytical equation, which is based on a 2-D approximation, is used for calculating the flux density. The 2-D theory is shown to be reasonably good at predicting the magnetic flux density at the mean radius of the magnet for the range of axial field motors studied. For rough calculations of the field in the gap the theory is adequate. A technique for estimating the magnetization of the magnets is described. >
Structure of the Universe in the two-dimensional model of adhesion

Un modele de formation de la structure a grande echelle dans un univers domine par de la matiere sombre, nomme modele d'adhesion, est developpe. Les simulations numeriques, realises avec le modele d'adhesion 2D et un systeme de N corps 2D, avec les memes conditions initiales, sont comparees et analysees