Miracle-dz/UniFAR-FTUs huggingface dataset:
The Compatibility of Structural Equation Modelling and Cluster Analysis: an Example

Compatibilité des modèles à équations linéaires et de l'analyse claasificatoire: un exemple. Un modèle à équations linéaires est construit pour examiner les effets de la réussite en mathématiques et des sentiments par rapport à l'école sur la représentation de soi. Les résultats indiquent un bon ajustement avec les données. Une analyse classificatoire des deux variables exogènes. réussite en mathématiques et sentiments par rapport à l'école. a fait ressortir sept sous-groupes. Le modèle ne s'ajuste pas aux données dans chaque sous-groupes. impliquant que des processus différents étaient en jeux à l'intérieur de chaque sous-groupes. L'estimation paramètrique dans chaque sous-groupe montre. en effet. que la contribution de la réussite en math et les sentiments par rapport à l'école diffèrent dans chaque sous-groupes. et que différents processus sont en jeux. La conclusion est que 1 analyse classificatoire peut clarifier et améliorer les modèles à équations linéaires.
Eigenspectral Analysis of Hermitian Adjacency Matrices for the Analysis of Group Substructures

ABSTRACT In this paper we propose the use of the eigensystem of complex adjacency matrices to analyze the structure of asymmetric directed weighted communication. The use of complex Hermitian adjacency matrices allows to store more data relevant to asymmetric communication, and extends the interpretation of the resulting eigensystem beyond the principal eigenpair. This is based on the fact, that the adjacency matrix is transformed into a linear self-adjoint operator in Hilbert space. Subgroups of members, or nodes of a communication network can be characterised by the eigensubspaces of the complex Hermitian adjacency matrix. Their relative ‘traffic-level’ is represented by the eigenvalue of the subspace, and their members are represented by the eigenvector components. Since eigenvectors belonging to distinct eigenvalues are orthogonal the subgroups can be viewed as independent with respect to the communication behavior of the relevant members of each subgroup. As an example for this kind of analysis the EIES data set is used. The substructures and communication patterns within this data set are described.
Voyager and Pioneer missions to the boundaries of the heliosphere

The interaction of the solar wind with the interstellar medium is expected to result in a complex, probably dynamic outer heliospheric boundary region. In increasing distance from the Sun the boundary region includes the solar wind termination shock, the heliopause, and perhaps a heliobow-shock. The continuing missions of Voyager 1 and 2 and Pioneer 10 and 11 provide a unique opportunity to make in situ particle and field observations of the boundaries of the heliosphere and associated phenomena. Observations already made by these spacecraft suggest that the termination shock may be located 60-100 AU from the Sun. Voyager 1 will reach 60 AU in 1995 and 100 AU in 2006. NASA's Space Physics Division is planning with the Voyager and Pioneer Projects to ensure timely and maximum scientific return from spacecraft encounters with the solar wind termination region. Initial emphasis is on being able to reliably determine when an encounter is imminent, so that spacecraft tracking and spacecraft and instrument configurations can be changed to encounter modes. It is anticipated that multiple encounters with heliospheric boundaries will occur due to motion of the boundaries in response to large variations in the solar wind pressure.
Simple method for generating distance spectrum and multiplicities of convolutional codes

The author presents a simple algorithm for generating the distance spectrum and multiplicities of convolutional codes. It is different from the existing methods in that no topological searching or matrix inversion is involved. Instead, the method presented consists of the recursion of a set of difference equations with a properly selected operational sequence. The computational cost of the new algorithm can be easily predicted and is modest.
Temperature Inversion in the Io Plasma Torus

Abstract We present in situ measurements of electron parameters as a function of latitude in the Io plasma torus, deduced from an extended analysis of the radio and plasma wave data acquired on board Ulysses. We find that the density and temperature are anti-correlated and obey an approximate polytrope law Te ∝ 1/ n e . We interpret this result with a simple model based on velocity filtration by the potential which confines the particles to the equator. In the absence of local thermal equilibrium, suprathermal particles overcome more easily the potential; thus the temperature increases with latitude in anticorrelation with the density, which decreases less steeply than the Gaussian corresponding to equilibrium. This explains the observed polytrope relation, and the calculated densities fit quite well the measured density profile. These results illustrate in the Io torus a general behavior of low-density inhomogeneous plasmas, anticipated by J. D. Scudder (1992, Astrophys. J. 398, 299-319).
A large-current, highly integrated switched-capacitor divider with a dual-branch interleaved topology and light load efficiency improvement

Because it is magnet-free and can achieve a high integration level, the switched-capacitor (SC) converter acting as a direct current transformer has many promising applications in modern electronics. However, designing an SC converter with large current capability and high power efficiency is still challenging. This paper proposes a dual-branch SC voltage divider and presents its integrated circuit (IC) implementation. The designed SC converter is capable of driving large current load, thus widening the use of SC converters to high-power applications. This SC converter has a constant conversion ratio of 1/2 and its dual-branch interleaved operation ensures a continuous input current. An effective on-chip gate-driving method using a capacitively coupled floating-voltage level shifter is proposed to drive the all-NMOS power train. Due to the self-powered structure, the flying capacitor itself is also a bootstrap capacitor for gate driving and thus reduces the number of needed components. A digital frequency modulation method is adopted and the switching frequency decreases automatically at light load to improve light load efficiency. The converter IC is implemented using a 180 nm triple-well BCD process. Experimental results verify the effectiveness of the dual-branch interleaved operation and the self-powered gate-driving method. The proposed SC divider can drive up to 4 A load current with 5–12 V input voltage and its power efficiency is as high as 96.5%. At light load, using the proposed optimization method, the power efficiency is improved by 30%.
Experimental and theoretical study of linewidth narrowing in Brillouin fiber ring lasers

In Brillouin fiber lasers, the phase fluctuations of the pump laser are transferred to the emitted Stokes field after being strongly reduced. The result is a linewidth narrowing that we study both experimentally and theoretically. We derive simple expressions to connect the linewidths of the waves interacting in the fiber, and we show that the magnitude of the narrowing effect depends only on the acoustic damping rate and the cavity loss rate. We successfully compare these theoretical predictions with experimental results obtained by recording the response of a Brillouin fiber ring laser to frequency modulation of the pump field.
The Age of the Sun

The age of the sun is deduced to be 4.49 + or - 0.04 Gyr. This determination is based on the ages of the oldest meteorites, current models of solar system formation, and the premain-sequence evolution of a 1-solar-mass star from T Tauri phase to the ZAMS. Prior to this it was common to use an age of 4.7 Gyr for the sun. Comparing a solar model evolved to 4.5 Gyr with a model evolved to 4.7 Gyr shows that the 200 Myr difference in their ages has very little effect on the helium abundance and mixing-length parameters of the solar models. 16 refs.
FLUID DYNAMIC BEHAVIOR OF HEAT EXCHANGERS WITH ACTIVE CAVITIES: A NUMERICAL STUDY

Numerical simulations have been performed on a series of cavities (called active cavities here) with a peculiar, purpose-fitted geometry, located on the external surface of tubular heat exchanger passages and on one side of the active wall in a flat plate heat exchanger. An incompressible fluid with a flow Reynolds number of 42,000 was considered and three turbulence models were compared: k- k , Spalart--Allmaras and large eddy (LES). The purpose of the cavities is to increase the heat transfer on the surface on which they are applied: some limited comparisons with an independent set of experimental data are also presented.
Coherent Scattering of Electromagnetic Waves From a Layer of Random Medium With Rough Boundaries

This paper is concerned about coherent waves in a random medium layer with randomly rough boundaries which on the average are parallel planes. The fluctuations of the problem are assumed to be small and smooth. All the statistical parameters of the problem are stationary and independent of each other. The bottom surface is assumed to be perfectly conducting. Using transferred boundary conditions the problem of electromagnetic wave scattering from this layer is formulated as a single integral equation where the random fluctuations of the problem are represented as a zero mean random operator. Smoothing leads to an integral equation for the coherent fields. Various operators are employed to this equation to obtain expressions for the principal parameters of the coherent fields such as propagation constants and Fresnel coefficients. Some examples are considered to illustrate the characteristics of our results.
Improving the performance of Mach–Zehnder interferometer with the dispersion response of the add-drop ring resonator

We use the add-drop ring resonator (ADRR) to produce the normal and anomalous dispersion simultaneously and apply these two dispersion responses to enhance the sensitivity of the Mach–Zehnder interferometer (MZI). To estimate the sensing ability of the ADRR assisted MZI, the dispersion sensitivity of the structure is theoretically and experimentally demonstrated. For two equal amplitude coupling coefficients, a 19.2-fold increase in the dispersion sensitivity is experimentally achieved, a little lower than 19.5-fold predicted in theory. This value can be futher increased by minimizing the attenuation or by choosing different amplitude coupling coefficient settings at different coupling regions. To acquire better dispersion sensitivity, only output port one should be utilized at the over-coupling region, and two output ports should be adopted at the under-coupling region.
Improved neighborhood preserving embedding approach

In this paper, we proposed a manifold-based algorithm called Orthogonal Neighborhood Preserving Embedding (ONPE) for dimensionality reduction and feature extraction. ONPE algorithm is based on the Neighborhood Preserving Embedding (NPE) algorithm. NPE is an unsupervised dimensionality reduction method which is the linear approximation of classical nonlinear method. However, the feature vectors obtained by NPE are nonorthogonal. ONPE inherits NPE's neighborhood preserving property and produces orthogonal feature vectors. As orthogonal eigenvectors preserve the metric structure of the image space, the ONPE algorithm has more neighborhood preserving power and discriminating power than NPE. Furthermore, ONPE can find the mapping which best preserves the manifold's estimated intrinsic geometry structure in a linear sense. Experimental results show that ONPE is an effective method for feature extraction.
A review of the coherent optical control of the exciton and spin states of semiconductor quantum dots

The spin of a carrier trapped in a self-assembled quantum dot has the potential to be a robust optically active qubit that is compatible with existing III–V semiconductor device technology. A key requirement for building a quantum processor is the ability to dynamically prepare, control and detect single quantum states. Here, experimental progress in the coherent optical control of single semiconductor quantum dots over the past decade is reviewed, alongside an introductory discussion of the basic principles of coherent control.
The split common fixed-point problem for demicontractive mappings

Based on the very recent work by Censor and Segal (2009 J. Convex Anal. 16 587–600) and inspired by Xu (2006 Inverse Problems 22 2021–34) and Yang (2004 Inverse Problems 20 1261–6), we investigate an algorithm for solving the split common fixed-point problem for the class of demicontractive operators in a Hilbert space. Our results improve and/or develop previously discussed feasibility problems and related algorithms. It is worth mentioning that the convex feasibility formalism is at the core of the modeling of many inverse problems and has been used to model significant real-world problems, for instance, in sensor networks, in radiation therapy treatment planning, in computerized tomography and data compression, see Censor et al (2006 Phys. Med. Biol. 51 2353–65) and Combettes (1996 Adv. Imaging Electron. Phys. 95 155–270) and references therein.
A color and texture based multi-level fusion scheme for ethnicity identification

Ethnicity identification of face images is of interest in many areas of application. Different from face recognition of individuals, ethnicity identification classifies faces according to the common features of a specific ethnic group. This paper presents a multi-level fusion scheme for ethnicity identification that combines texture features of local areas of a face using local binary patterns with color features using HSV binning. The scheme fuses the decisions from a k-nearest neighbor classifier and a support vector machine classifier into a final identification decision. We have tested the scheme on a collection of face images from a number of publicly available databases. The results demonstrate the effectiveness of the combined features and improvements on accuracy of identification by the fusion scheme over the identification using individual features and other state-of-art techniques.
Super-miniature x-ray tube

A transmission x-ray tube super-miniature in size is described. The x-ray tube is 5mm in diameter, and comprised of a built-in electron-emitter assembly and a grounded planar target. The key component of the emitter assembly is a Kovar pipe 2mm in diameter, inside which carbon nanofibers aligned on an electro-polished molybdenum tip are loaded to serve as the electron emitter. This type of electron emitter is highly robust in non-ultrahigh vacuum, continuing to field emit electrons for 100h or longer at pressures in the 10−5Pa region. This x-ray tube provides clear x-ray images.
Improved rank‐niche evolution strategy algorithm for constrained multiobjective optimization

Purpose – The purpose of this paper is to improve and to extend the use of original rank‐niche evolution strategy (RNES) algorithm to solve constrained and unconstrained multiobjective optimization problems.Design/methodology/approach – A new mutation step size is developed for evolution strategy. A mixed ranking procedure is used to improve the quality of the fitness function. A self‐adaptive sharing radius is developed to save computational time. Four constraint‐treating methods are developed to solve constrained optimization problems. Two of them do not use penalty function approach.Findings – The improved RNES algorithm finds better quality Pareto‐optimal solutions more efficiently than the previous version. For most test problems, the solutions obtained by improved RNES are better than, or at least can be compared with, results from other papers.Research limitations/implications – The application of any evolutionary algorithm to real structural optimization problems would face a problem of spending h.
Factors Affecting Virtual Gift Acceptance: Mediating Roles Of Hedonic And Utilitarian Values

There is little formalized knowledge of virtual gifting in the information technology (IT) literature. The objective of this paper is to explore the factors affecting the acceptance of virtual gifts and specifically the factors within a virtual gift that affect individuals’ intention to accept it and the mediating role of these factors. This research combines several acceptances, hedonic and utilitarian view related theories to explore the factors affecting acceptance of virtual gifts. Moreover, this study investigates the effects of usefulness, beautifulness, subjective norms of the receiver, and importance of the giver of a virtual gift as determinants of its utilitarian or/and hedonic value. The study finally examines the impact of the normative quality of the giver on the appropriateness of the virtual gift. A proposed research model will be tested using survey data and PLS (Partial least square). The implications of the research will be discussed.
An Edge-based Anisotropic Mesh Refinement Algorithm and Its Application to Interface Problems

Based on an error estimate in terms of element edge vectors on arbitrary unstructured simplex meshes, we propose a new edge-based anisotropic mesh refinement algorithm. As the mesh adaptation indicator, the error estimate involves only the gradient of error rather than higher order derivatives. The preferred refinement edge is chosen to reduce the maximal term in the error estimate. The algorithm is implemented in both twoand three-dimensional cases, and applied to the singular function interpolation and the elliptic interface problem. The numerical results demonstrate that the convergence order obtained by using the proposed anisotropic mesh refinement algorithm can be higher than that given by the isotropic one. AMS subject classifications: 65N22, 65N50, 65N55
Effect of temperature on the electric breakdown strength of dielectric elastomer

DE (dielectric elastomer) is one of the most promising artificial muscle materials for its large strain over 100% under driving voltage. However, to date, dielectric elastomer actuators (DEAs) are prone to failure due to the temperature-dependent electric breakdown. Previously studies had shown that the electrical breakdown strength was mainly related to the temperature-dependent elasticity modulus and the permittivity of dielectric substances. This paper investigated the influence of ambient temperature on the electric breakdown strength of DE membranes (VHB4910 3M). The electric breakdown experiment of the DE membrane was conducted at different ambient temperatures and pre-stretch levels. The real breakdown strength was obtained by measuring the deformation and the breakdown voltage simultaneously. Then, we found that with the increase of the environment temperature, the electric breakdown strength decreased obviously. Contrarily, the high pre-stretch level led to the large electric breakdown strength. What is more, we found that the deformations of DEs were strongly dependent on the ambient temperature.
Growth and electronic structure of alkali metal adlayers on icosahedral Al70.5Pd21Mn8.5

We report x-ray photoelectron spectroscopy (XPS) study of Na and K adlayers on icosahedral ${\mathrm{Al}}_{70.5}{\mathrm{Pd}}_{21}{\mathrm{Mn}}_{8.5}$ $(i\text{\ensuremath{-}}\mathrm{Al}\text{\ensuremath{-}}\mathrm{Pd}\text{\ensuremath{-}}\mathrm{Mn})$ quasicrystal. The Na $1s$ core-level exhibits a continuous linear shift of $0.8\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ towards lower binding energies (BE) with increasing coverage up to one monolayer (ML) saturation coverage. In the case of $\mathrm{K}∕i\text{\ensuremath{-}}\mathrm{Al}\text{\ensuremath{-}}\mathrm{Pd}\text{\ensuremath{-}}\mathrm{Mn}$, a similar linear shift in the K $2p$ spectra towards lower BE is observed. In both cases, the plasmon related loss features are observed only above 1 ML. The substrate core-level peaks, such as Al $2p$, do not exhibit any shift with the adlayer deposition up to the highest coverage. Based on these experimental observations and previous studies of alkali metal growth on metals, we conclude that below 1 ML, both Na and K form a dispersed phase on $i\text{\ensuremath{-}}\mathrm{Al}\text{\ensuremath{-}}\mathrm{Pd}\text{\ensuremath{-}}\mathrm{Mn}$ and there is hardly any charge transfer to the substrate. The variation of the adlayer and substrate core-level intensities with coverage indicates layer by layer growth.
Smooth Decomposition Analysis and Order Reduction of Nonlinear Mechanical Systems Under Random Excitation

This paper presents a possible alternative procedure to the Karhunen-Loeve approach to construct reduced order models which capture accurately the dynamics of nonlinear discrete mechanical systems under random excitation. This procedure combines the Smooth Decomposition method and the Petrov-Galerkin approximation. The smooth decomposition method is a multivariate-data analysis method characterizing coherent structures (the smooth modes) as the eigenvectors of the generalized eigenproblem defined from the covariance matrix of the displacement field and the covariance matrix of the velocity field. The Petrov-Galerkin approximation is used to project the dynamics in a subspace generated by a set of the smooth modes. The Petrov-Galerkin approximation preserves the second order structure of the equations of motion. The procedure is considered for a mechanical system including a strongly nonlinear end-attachment. The efficiency of the approach is analyzed comparing the power spectral density functions of the reduced-order model and of the original system.Copyright © 2012 by ASME
Interference Effect of Downstream Strip-Plate on the Crossflow Vibration of a Square Cylinder

Wind tunnel experiments are carried out to investigate interference effect of downstream strip plate of width w = d on the crossflow vibration of a square cylinder with a side length d =26mm. While sufficient suppression of Karman vortex induced vibration is not attained by plates with crossflow height less than l d =4 d , the galloping is suppressed even by a square plate, i.e. l d = d , when the gap ratio 1< s / d <2.0. When a plate of l d ≦ 2 d is set with a gap ratio s / d <1~1.4, a large vibration occurs at U >5m/s with the maximum amplitude at around s / d =0.3. The amplitude at s / d =0.3 increases divergently with flow velocity. Measurement of the lift force on the square cylinder and the velocity in the near wake for the corresponding fixed system shows no evidence for periodic change of flow responsible for the vibration. A prediction of this vibration based on the quasi-static hypothesis suggests that the vibration is caused by the fluid-elastic instability but not by a periodic vortex shedding. Hence, the name “Wake Body Interference Fluid Elastic Vibration (WBIFEV)” is proposed for this vibration.
European Government Bond Markets and Monetary Policy Surprises: Returns, Volatility and Integration

In this paper we investigate the response of bond markets to euro area and US monetary policy shocks. Specifically, we analyze the effect of unexpected changes in interest rates implemented by the European Central Bank (ECB) and the Federal Open Market Committee (FOMC) not only on the returns, but also on the volatility and the integration of European government bond markets. For all three characteristics our results show that the response to monetary policy surprises varies across groups of countries (EMU EU-15 central, EMU EU-15 peripheral, non-EMU EU-15 and non-EMU new EU). We also find that the effects of monetary policy announcements on the level of integration are more pronounced than those on returns and volatility. Finally, our results paint a complex picture of the effects of monetary policy news releases on the level of integration. The effect of ECB monetary policy surprises differs across old and new European Union members, while the effect of FOMC monetary policy surprises differs across EMU and non-EMU members.