Miracle-dz/UniFAR-FTUs huggingface dataset:
The Performance of the Full Information Maximum Likelihood Estimator in Multiple Regression Models with Missing Data

A Monte Carlo simulation examined the performance of a recently available full information maximum likelihood (FIML) estimator in a multiple regression model with missing data. The effects of four independent variables were examined (missing data technique, missing data rate, sample size, and correlation magnitude) on three outcome measures: regression coefficient bias, R 2 bias, and regression coefficient sampling variability. Three missing data patterns were examined based on Rubin’s missing data theory: missing completely at random, missing at random, and a nonrandom pattern. Results indicated that FIML estimation was superior to the three ad hoc techniques (listwise deletion, pairwise deletion, and mean imputation) across the conditions studied. FIML parameter estimates generally had less bias and less sampling variability than the three ad hoc methods.
Atomic scale annealing effects on InxGa1−xNyAs1−ystudied by TEM three-beam imaging

A transmission electron microscopy (TEM) method for simultaneous measurement of indium and nitrogen content in InGaNAs at atomic scale is introduced, tested, and applied to investigate thermal annealing effects on structural properties. Our technique is based on the extraction of strain and chemical sensitive contrast from a single three-beam TEM lattice fringe image by subsequent decomposition into 220 and 020 two-beam fringe images, being free of nonlinear imaging artifacts. From comparison with simulated strain and 020 fringe amplitude, concentration maps and profiles are derived. For this purpose, the Bloch-wave approach is used with structure factors adapted for chemical bonding, static atomic displacements, as well as diffuse losses due to static and thermal disorder. Application to In0.28Ga0. 72N0.025As0. 975 before and after annealing at 670 ◦C yields dissolution of In-rich islands and N-rich clusters and formation of a quantum well with nearly constant thickness and homogeneous elemental distributions, resulting in symmetric profiles along growth direction. To verify that these structural transitions are indeed correlated with typically observed changes of optical properties during thermal annealing, photoluminescence spectra are presented, revealing an increase in intensity by a factor of 20 and a strong blue shift of 60 meV.
A scalable approach to modeling nonlinear structure in hyperspectral imagery and other high-dimensional data using manifold coordinate representations

In the past we have presented a framework for deriving a set of intrinsic manifold coordinates that directly parameterize high-dimensional data, such as that found in hyperspectral imagery1234567.10 In these previous works, we have described the potential utility of these representations for such diverse problems as land-cover mapping and in-water retrievals such as bathymetry.10 Because the manifold coordinates are intrinsic, they offer the potential for significant compression of the data, and are furthermore very useful for displaying data structure that can not be seen by linear image processing representations when the data is inherently nonlinear. This is especially true, for example, when the data are known to contain strong nonlinearities, such as in the reflectance data obtained from hyperspectral imaging sensors over the water, where the medium itself is attenuating235.7 These representations are also potentially useful in such applications as anomaly finding2.3 A number of other researchers have looked at different aspects of the manifold coordinate representations such as the best way to exploit these representations through the backend classifier,15 while others have examined alternative manifold coordinate models.14 In this paper, we provide an overview of our scalable algorithm for deriving manifold coordinate representations of high-dimensional data such as hyperspectral imagery, describe some of our recent work to improve the local estimation of spectral neighborhood size, and demonstrate the benefits for problems such as anomaly finding.
On a certain formula of mechanical quadratures with non-equidistant ordinates

where n is a certain given finite quantity, u(x) is a bounded (R)-integrable function defined on (-n, n), a, ai, ni(i = 1, 2, , s) are to be determined, making use of certain conditions to be stated later. This formula has been suggested by G. F. Hardyt and given, for s =2, in King's Text-Book. : A discussion of it, for s = 2, 3, has been given by J. W. Glover. Since the formula under consideration is being frequently used and yields a very close approximation, it seems to be of interest to investigate its theoretical basis for any positive integral value of s. The following questions naturally arise. (i) Existence of formula (A) for any s = 1, 2, 3, ; i.e., can we always find in (A) real a, a,, n,(.i=l, 2, , s) satisfying (1)? (ii) Theoretical basis of (A), i.e., find an algorithm yielding the values of the constants enumerated in (i), for any positive integer s. (iii) Convergence of formula (A), i.e. investigate
Secondary sampling algorithm in harmonic distortion estimation

Harmonic analysis based on Fast Fourier Transform (FFT) is usually used for estimating harmonic distortion degree. However, the estimation precision is seriously affected by spectral leakage caused by non-synchronous sampling. To low the spectrum leakage effect and improve the estimation precision, a novel kind of the software frequency measurement and secondary sampling algorithm for approximately synchronous sampling is proposed. And the principle of the proposed algorithm is profoundly investigated. Furthermore, the algorithm error is comprehensively analyzed. The results of the simulation and the application show that the error of the distortion degree can be less than 1% by increasing signal sampling frequency, and the algorithm is feasible, efficient and effective to inhibit the spectrum leakage in harmonic analysis and ensure high accuracy in harmonic analysis and harmonic distortion degree measurement.
Pseudoempirical‐likelihood‐based method using calibration for longitudinal data with dropout

In observational studies, interest mainly lies in estimation of the population level relationship between the explanatory variables and dependent variables, and the estimation is often undertaken by using a sample of longitudinal data. In some situations, the longitudinal data sample features biases and loss of estimation efficiency due to non‐random dropout. However, inclusion of population level information can increase estimation efficiency. We propose an empirical‐likelihood‐based method to incorporate population level information in a longitudinal study with dropout. The population level information is incorporated via constraints on functions of the parameters, and non‐random dropout bias is corrected by using a weighted generalized estimating equations method. We provide a three‐step estimation procedure that makes computation easier. Some commonly used methods are compared in simulation studies, which demonstrate that our proposed method can correct the non‐random dropout bias and increase the estimation efficiency, especially for small sample sizes or when the missing proportion is high. In some situations, the improvement in efficiency is substantial. Finally, we apply the method to an Alzheimer's disease study.
Thermal conductivity and thermoelectric power of heavily doped n-type silicon

Experimental values are given of the thermal conductivity and thermoelectric power of n-type silicon doped with phosphorus, antimony or arsenic, containing 4*1019 to 6*1025 m-3 electrons at room temperature, covering the range 4-300 degrees K. A theoretical treatment, using the variational method, suggests that the ratio of phonon drag component of thermoelectric power to thermal conductivity should be independent of carrier concentration, if the latter is not too large. This is verified experimentally; the temperature variation of the ratio is in satisfactory agreement with theory, which also gives the correct order of magnitude for the absolute value.
A Search for Bright Kuiper Belt Objects

Abstract Since 1992, 60 large Kuiper Belt objects have been detected by ground-based telescopes. Previous surveys which have detected objects have searched approximately 60□° and detected objects with magnitudes 20·6 < mR < 25·0. However, the luminosity function of brighter Kuiper Belt objects is not well determined. The detection of brighter objects would improve our ability to determine the Kuiper Belt objects' surface composition and provide constraints on the population statistics of different formation mechanisms. This paper describes a survey of 12·0□° of sky near the ecliptic to a limiting magnitude of mR ∼ 21. A slow moving candidate was detected near the magnitude limit of the survey.
Joint Estimation of Model Parameters and Outlier Effects in Time Series

Time series data are often subject to uncontrolled or unexpected interventions, from which various types of outlying observations are produced. Outliers in time series, depending on their nature, may have a moderate to significant impact on the effectiveness of the Standard methodology for time series analysis with respect to model identification, estimation, and forecasting. In this article we use an iterative outlier detection and adjustment procedure to obtain joint estimates of model parameters and outlier effects. Four types of outliers are considered, and the issues of spurious and masking effects are discussed. The major differences between this procedure and those proposed in earlier literature include (a) the types and effects of outliers are obtained based on less contaminated estimates of model parameters, (b) the outlier effects are estimated simultaneously using multiple regression, and (c) the model parameters and the outlier effects are estimated jointly. The sampling behavior of the test s.
Ion holes in the slow solar wind: Hybrid simulations

The spatio‐temporal evolution of large‐amplitude Alfvénic wave packets is investigated using a one‐dimensional hybrid model. For conditions prevailing in the slow solar wind plasma, namely β ∼ 1 (β being the ratio of kinetic pressure to magnetic pressure) and electron temperature Te greater than proton temperature Ti, we observe two branches of ion density holes. One is propagating forward and the other backward in the inertial frame of reference. Kinetic effects as well as strong coupling between density and magnetic field fluctuations are responsible for generating these holes. For the first time, we show the possibility of an Alfvénic wave packet decay into a new and unanticipated nonlinear wave mode that does not exist in the current literature. As T(=Ti/Te) increases, the ion holes disappear because of Landau damping. In the slow solar wind the scale sizes of these ion density cavities are ≤ 2sec. We predict the occurence of such cavites in the slow solar wind; these would be observable when high time resolution plasma data become available.
Nonlinear dynamics of electron bunches in the presence of dissipative effects

The transition phase between two nonlinear regimes of electron-beam–wave interaction depending on the amplitude and the nature of the effective dissipation is investigated with the help of numerical simulations. Effective dissipation due to wave escaping to infinity out of the beam–wave interaction region as well as to collisions in the background plasma is considered. If the dissipation is strong enough, the evolution of the electron beam proceeds in a general way, independently of the type of dissipation and of the nature of the considered waves: structures of strongly concentrated electron bunches are formed. These bunches are not trapped in the wave, and decelerate continuously owing to friction on waves: in the presence of dissipation, the usual quasiperiodic exchange of energy between the wave and the trapped particles, which prevents the wave from collapsing, does not occur. Considering beam interaction with a finite number of waves (modulated wave packet), it is shown that, if the dissipation is strong enough, the structure of electron bunches is dynamically stable in a range of times exceeding several characteristic times of their formation.
Measurement of Effective Bulk Modulus for Hydraulic Oil at Low Pressure

Oil pr-operties are very important input parameters for the sinaulation of hydraulic components. Precise values of effective bulk modules at low pressures are especially required to improve the simulation accuracy of the pumps suction side or of cavitation in pumps or valves. So far, theoretical equations to compute the effective bulk modulus of hydraulic oil have not been experimentally verified, and only poor measured data are available to calculate the effective bulk modulus at low pressure. Therefore in this paper, the theoretical equation was verified for effective bulk moduli based on measurements of pressure change as a function of volume change at low pressures, varying temperature, entrained air content, and type of state change. Furthermore, the comparison of effective bulk moduli calculated with three different methods (mass-change, volume-change, and sound-speed method) shows that the effective bulk naodulus can be calculated well from the measurement results of all three methods. The calculated effective bulk moduli values show little variation among the methods. Additionally, the release pressure of dissolved air in oil and the change of the polytropic gas constant depending on the speed of volume change rate were identified in this study.
Evidence for Neutrino- and Antineutrino-Induced Coherent π 0 Production

The angular distribution of isolated photon conversion pairs, collected during the proton-synchrotron--Gargamelle . nu. and nu-bar freon experiments, has been examined to determine whether any anomalous small-angle production is present. There is a definite excess of conversion pairs over what is expected from resonantly produced and neutron-induced . pi. /sup 0/'s. This excess is in accord with . nu. - (nu-bar) induced coherent . pi. /sup 0/ production off nuclei.
Density Measurements in an Axisymmetric Underexpanded Jet Using Background Oriented Schlieren Technique 2004-2603

The Background Oriented Schlieren (BOS) technique13; has been applied to obtain the density field of a13; complex underexpanded jet flow. The measurements13; were made on an axisymmetric converging nozzle13; (Mj=1) operating at moderately and highly expanded13; values of nozzle pressure ratios. The validation of the13; Filtered Back Projection Tomography (FBPT) used13; in this technique was done by extracting the central13; plane of a 4-jet configuration. Density fields for two13; nozzle expansion ratios are presented. The study13; shows that meaningful quantitative data can be13; extracted using minimal hardware with this13; technology.13;
Correlation analysis of objectively defined galaxy and cluster catalogues

Les resultats de l'analyse de l'agencement des galaxies a partir du catalogue des galaxies COSMOS/UKST de Stevenson P.R. F. et al. (1985, Mon. Not. R. astr. Soc., 213) sont presentes. Ces resultats sont d'abord reexamines dans le cadre de la fonction de correlation des galaxies en vue de tester la stabilite du resultat par rapport aux effets systematiques et d'etendre l'analyse a de plus grandes echelles angulaires. La methode de Turner et Gott est ensuite utilisee pour detecter les groupes et les amas dans ces catalogues. La fonction de correlation croisee galaxie-amas est ensuite presentee. L'analyse de correlation est enfin appliquee a des catalogues simules de galaxies et d'amas
Two-Fluid CFD Simulations of Cap Bubble Flow Using the Two-Group Interfacial Area Transport Equations

The two-group interfacial area transport equations (IATE) are coupled with an existing three dimensional three-field two-fluid model for adiabatic flow simulations in the bubbly-cap bubble regime. The mechanisms of the two-group IATE bubble interactions that have been proposed and validated in the past for one dimension are extended to a multi-dimensional model. The CFD simulations were validated using the data of Sun et al. [1] where the phase distribution, interfacial area concentration and velocity distribution in the cross-section for small and cap bubbles were measured separately using the four-sensor conductivity probe at four axial locations. The results demonstrate that the coupling is feasible. An interfacial turbulent diffusion force constitutive relation is modified and a new mechanism for inter-group bubble transport is identified and constituted.
Ferroelectric Nanotubes Array Growth in Anodic Porous Alumina Nanoholes on Silicons

Ferroelectric nanotubes were fabricated by the wetting on the pore wall of porous body such as Anodized Aluminium Oxide (AAO) thin films on silicon substrate. Sol-gel syntheses within the pores create the PbZrTiO3 (PZT) nanotube arrays. The diameter and the aspect ratio of vertically aligned nanopores are about 40 nm and 8, respectively. Ferroelectric properties of PZT nanotubes were observed by the Electrostatic Force Microscope (EFM). These nanotubes should provide promising materials for fundamental investigations on nanoscale ferroelectricity, and be useful in ferroelectric nanostorages media.
Investigation of the Effect of Substituents on Electronic and Charge Transport Properties of Benzothiazole Derivatives

A series of new benzothiazole-derived donor–acceptor-based compounds (Comp1–4) were synthesized and characterized with the objective of tuning their multifunctional properties, i.e., charge transport, electronic, and optical. All the proposed structural formulations (Comp1–4) were commensurate using FTIR, 1H NMR, 13C NMR, ESI-mass, UV–vis, and elemental analysis techniques. The effects of the electron-donating group (-CH3) and electron-withdrawing group (-NO2) on the optoelectronic and charge transfer properties were studied. The substituent effect on absorption was calculated at the TD-B3LYP/6-31+G** level in the gas and solvent phases. The effect of solvent polarity on the absorption spectra using various polar and nonpolar solvents, i.e., ethanol, acetone, DMF, and DMSO was investigated. Light was shed on the charge transport in benzothiazole compounds by calculating electron affinity, ionization potential, and reorganization energies. Furthermore, the synthesized compounds were used to prepare thin films on the FTO substrate to evaluate the charge carrier mobility and other related device parameters with the help of I-V characteristic measurements.
A feature extraction algorithm for missing trajectory data clustering

Feature extraction is one of the critical technologies in trajectory data clustering. Extracting useful features for trajectory clustering is a difficult problem when there are missing segments in trajectories. This paper proposes a feature extraction algorithm for missing trajectories clustering. The algorithm converts trajectories into images, a multi-layer image preprocessing method is proposed to reduce the information loss during image processing. Then build an autoencoder to extract image features. The loss function is designed according to the attention mechanism to highlight the effective information in the trajectory image. The autoencoder’s ability to handle missing trajectory segments is trained by adding artificial image masking. The effect of feature extraction is verified by clustering. Compared with the unimproved autoencoding and interpolation methods, the clustering effect of the features extracted by this algorithm is improved. At missing rate 50%, this is an increase of eight and six percentage points, respectively. It is proved that the algorithm in this paper is more suitable for missing trajectory feature extraction.
Robust stability of systems with nonlinear parameter dependence

Schur or Hurwitz stability of a characteristic polynomial whose coefficients are nonlinear functions of a set of free parameters is investigated. The nonlinear functions are restricted to polynomials in these parameters. The parameters lie in a given region of uncertainty. Methods for testing the robust stability are discussed, and a new method for solving a system of multivariate real polynomial equations is given. <<ETX>>
Locally optimal adaptive smoothing splines

Smoothing splines are widely used for estimating an unknown function in the nonparametric regression. If data have large spatial variations, however, the standard smoothing splines (which adopt a global smoothing parameter λ) perform poorly. Adaptive smoothing splines adopt a variable smoothing parameter λ(x) (i.e. the smoothing parameter is a function of the design variable x) to adapt to varying roughness. In this paper, we derive an asymptotically optimal local penalty function for λ(x)∈C 3 under suitable conditions. The derived locally optimal penalty function in turn is used for the development of a locally optimal adaptive smoothing spline estimator. In the numerical study, we show that our estimator performs very well using several simulated and real data sets.
Design Methodology of Single-Layer Dual-Band Metasurfaces for Leaky-Wave Antennas

Leaky-wave antennas (LWAs) are considered a good option in applications where medium-to-high directivity levels are required. In this work, we present a new design methodology for dual-band LWAs (Fabry–Pérot type). The proposed methodology is based on the use of a single partially reflective surface (PRS) that fulfills the resonant condition at two different frequencies. Consequently, a dual-band single-layer antenna can be designed. The potential of this methodology is demonstrated through two different designs of antennas showing also how control of the directivity is also possible. A prototype is manufactured and measured to validate the presented methodology and theoretical results.
Breast Cancer Detection in Mammogram Images Using K–Means++ Clustering Based on Cuckoo Search Optimization

Traditional breast cancer detection algorithms require manual extraction of features from mammogram images and professional medical knowledge. Still, the quality of mammogram images hampers this and extracting high–quality features, which can result in very long processing times. Therefore, this paper proposes a new K–means++ clustering based on Cuckoo Search Optimization (KM++CSO) for breast cancer detection. The pre-processing method is used to improve the proposed KM++CSO method more segmentation efficiently. Furthermore, the interpretability is further enhanced using mathematical morphology and OTSU’s threshold. To this end, we tested the effectiveness of the KM++CSO methods on the mammogram image analysis society of the Mini–Mammographic Image Analysis Society (Mini–MIAS), the Digital Database for Screening Mammography (DDSM), and the Breast Cancer Digital Repository (BCDR) dataset through cross-validation. We maximize the accuracy and Jaccard index score, which is a measure that indicates the similarity between detected cancer and their corresponding reference cancer regions. The experimental results showed that the detection method obtained an accuracy of 96.42% (Mini–MIAS), 95.49% (DDSM), and 96.92% (BCDR). On overage, the KM++CSO method obtained 96.27% accuracy for three publicly available datasets. In addition, the detection results provided the 91.05% Jaccard index score.
NUMERICAL SIMULATION OF CONTINUOUS CHIP FORMATION DURING NON‐STEADY ORTHOGONAL CUTTING

A finite element model for numerical simulation of non‐steady but continuous chip formation under orthogonal cutting conditions is described. The problem is treated as coupled thermo‐mechanical. A velocity approach has been adopted for the proposed solution. The computational algorithm takes care of dynamic contact conditions and makes use of an automatic remeshing procedure. The results of simulation yield complete history of chip initiation and growth as well as distributions of strain rate, strain, stress and temperature. The paper includes a detailed presentation of computational results for an illustrative case.