Miracle-dz/UniFAR-FTUs huggingface dataset:
Ti-O/Ti-N biomedical gradient films synthesized by metal vacuum arc plasma deposition and thermal oxidation

Summary form only given, as follows. In the last two decades, low temperature isotropic pyrolytic carbon (LTIC) has been the best material for fabricating artificial heart valves. However, the blood compatibility of LTIC is not sufficient for prolonged clinical use. TiO/TiN films were synthesized on 1Cr18Ni9Ti substrates. Ti-N films were deposited on 1Cr18Ni9Ti substrate by metal vacuum arc deposition. Then the as-deposited Ti-N films were oxidized at 600/spl deg/ for 25 min to synthesize Ti-O/Ti-N gradient film. In the complex Ti-O/Ti-N structure, the presence of Ti-O improves the blood compatibility and the main effect of Ti-N is to improve the mechanical properties. The composition, microstructure and mechanical properties of Ti-N and Ti-O/Ti-N gradient film were examined by XPS, XRD, microhardness tester and ball-on-disk wear test. Using a constant-potential method, the anodic polarization of the films has been measured, and the corrosion resistance properties of the films have been evaluated.
Current source imaging for high spatial resolution magnetocardiography in normal and abnormal rat cardiac muscles

The purpose of our study was to identify the current source produced by acute ischemia and infarction. We measured magnetocardiograms (MCG) and electrocardiograms (ECG) of five male rats using a high-resolution dc superconducting quantum interference device gradiometer in a magnetically shielded room after performing coronary artery occlusion. The spatial resolution of the detecting magnetic field of our system is higher than the typical system, thus permitting the measurement of magnetic fields in small animals. Distribution of the magnetic fields B(t) and distribution of |rot B(t)|, which corresponded to the distribution of the current source, were imaged by 12-channel MCGs. As a result, the distribution of current source changes in the affected area of the myocardium during the ST segment, and amplitude of the peak significantly increased after occlusion. Our system can be used to help clarify the mechanism of the ST shift related to severe heart disease.
Qualitative Comparative Analysis: How Inductive Use and Measurement Error Lead to Problematic Inference

An increasing number of analyses in various subfields of political science employ Boolean algebra as proposed by Ragin's qualitative comparative analysis (QCA). This type of analysis is perfectly justifiable if the goal is to test deterministic hypotheses under the assumption of error-free measures of the employed variables. My contention is, however, that only in a very few research areas are our theories sufficiently advanced to yield deterministic hypotheses. Also, given the nature of our objects of study, error-free measures are largely an illusion. Hence, it is unsurprising that many studies employ QCA inductively and gloss over possible measurement errors. In this article, I address these issues and demonstrate the consequences of these problems with simple empirical examples. In an analysis similar to Monte Carlo simulation, I show that using Boolean algebra in an exploratory fashion without considering possible measurement errors may lead to dramatically misleading inferences. I then suggest remedies that help researchers to circumvent some of these pitfalls.
The Earth's magnetic field in Southern Africa at the epoch, 1 July 1930

This paper is an attempt to determine the earth’s magnetic field in that part of Africa lying to the south of the Zambesi and Kunene Rivers, at the epoch 1930-50. The data used are: (1) Measurements made at about seven hundred stations by a number of previous workers, during the period 1900 to 1925, and already published. (2) Observations at about fifty of these stations made by the present writer between 1928 and 1930. These have been used to determine the secular variation, and thus to deduce the 1930-50 values of the magnetic field at all the other stations. The magnetic inclination is found to have changed in an almost linear manner, the maximum rate occurring in South-West Africa. The horizontal intensity has diminished at a gradually increasing rate, the maximum change being near Cape Town. The declination appears to have varied at a high rate until about 1928, and much more slowly since then. The greatest total changes are found near Durban. The results are presented in the form suggested by Ljungdahl. Maps with highly smoothed isomagnetic lines are used to show the probable ‘normal’ values of three magnetic elements (declination, inclination, and horizontal intensity), i.e. the component of the field not due to local magnetic disturbance. At each point of actual observation is placed a symbol indicating to what extent the observed value differs from that obtained by interpolation between the isomagnetic lines.
Cylindrical Jet -- Wind Interaction Model of Gamma-Ray Burst Afterglows

Observations on relativistic jets in radio galaxies, active galactic nuclei, and ``microquasars'' revealed that many of these outflows are cylindrical, not conical. So it is worthwhile to investigate the evolution of cylindrical jets in gamma-ray bursts. We discuss afterglows from cylindrical jets in a wind environment. Numerical results as well as analytic solutions in some special cases are presented. Our light curves are steeper compared to those in the homogeneous interstellar medium case, carefully considered by Cheng, Huang & Lu. We conclude that some afterglows, used to be interpreted as isotropic fireballs in a wind environment, can be fitted as well by cylindrical jets interacting with a wind.
Analysis of plasmon propagation along a chain of metal nanospheres using the generalized multipole technique

We compute the dispersion diagram of an infinite chain of silver nanospheres. The Drude model is used to define the permittivity of nanospheres, and the generalized multipole technique (GMT) is applied to solve the Maxwell’s equation and, thus, to analyze the plasmon excitation. The obtained dispersion diagram using the GMT is compared with the result of the dipolar interacting model as well as the quasistatic model. Results of the finite element method are also presented to verify the accuracy of our results. Finally, a finite chain of metal nanospheres is examined for its scattering and propagation length of the guided modes.
Fabrication of ordered FePt nanoparticles with a cluster gun

In this study we present a technique to obtain ordered fct FePt particles embedded in a C matrix. FePt nanoparticles are formed inside a high-pressure sputtering cell, called a particle gun (PG), and subsequently deposited on the substrate through a small orifice. These particles have a uniform size distribution with an average particle size that can be controlled in the range of 3–10 nm by adjusting the sputtering cell pressure, power, distance between the magnetron and the orifice, and by using a liquid nitrogen cooling jacket. The particles are converted to the L10 phase as they pass through a specially designed heating stage, attached to the top of the PG, heated by halogen lamps, thus avoiding alloying and oxidation effects. A strong dependence of coercivity on both the particle size and temperature was observed.
Waveguide ultrasonic force microscopy at 60 MHz

We present measurements using ultrasonic force microscopy at ∼60 MHz, operating in a “waveguide” mode in which the cantilever base is vibrated and flexural ultrasonic vibrations are launched down the cantilever without exciting any particular cantilever resonance. The nonlinearity of the tip-sample force-distance curve allows the conversion of a modulated ultrasonic frequency into a low frequency vibration of the cantilever, detected in a conventional atomic force microscope. Images of Ge quantum dots on a Si substrate show contrast related to elasticity and adhesion differences, and this is interpreted with the Johnson–Kendall–Roberts model of the force-distance curve.
Modeling of self-healing against cascading overload failures in complex networks

The development of online prognostic and fast-recovery technology promotes the realization of self-healing techniques. Considering the cascading overload failures as one of the major failure modes in real networks, we introduce a model for self-healing against overload propagation in complex networks due to malicious attack. Especially, we study the role of basic quantities (restoration timing and resource) in general self-healing restoration against cascading overload failures in network models of homogeneous (Erdős-Rényi) and heterogeneous (scale-free) networks. We demonstrate how networks during cascading failures can be saved from the brink of collapse by proper combination of both restoration timing and resource. And we find that optimal restoration timing for the model and realistic networks exists at a given restoration resource in the self-healing process.
Model reduction of two-dimensional separable-in-denominator systems via frequency domain balanced realization

Model reduction of a class of two-dimensional (2-D) separable-in-denominator digital filters (SDDF) using frequency domain balanced realization is proposed. The frequency domain controllability and observability Grammians are introduced. Their appropriate Lyapunov equations are developed. Various properties of the proposed frequency domain balanced structure are investigated. A comparison study of the proposed method with the available techniques is presented using a numerical example.
Priming of non-diatonic chords: The case of the Neapolitan chord

ABSTRACT Expectations induced by non-diatonic chords were investi-gated. Subjects were instructed to make a decision about the perceptual quality of the last chord (target) of se-quences. The target was either the dominant or subdomi-nant of the tonality of the sequence. In Experiment 1, the penultimate chord was either three or six steps (the Nea-politan chord) away from the target on the circle of fifths. Stimuli were presented with a piano timbre. For both musi-cians and non-musicians, closer penultimate chords cre-ated an advantage over distant chords for subdominant targets, but for dominant targets this advantage was elimi-nated. In order to investigate effects of melody on these results, Shepard chords were utilized in Experiment 2. In Experiment 2 the penultimate chord was either two or six steps away from the target. For musicians, the results of Experiment 1 were replicated; the distance of the penulti-mate chord had differential effects for processing of sub-dominant and dominant targets. However, responses of non-musicians were facilitated by a closer penultimate chord for both subdominant and dominant targets. Predic-tions of MUSACT (Bharucha, 1987) and Tonal Pitch Space (Lerdahl, 2001) are discussed together with results.
Conditional Inference Following Group Sequential Testing

The work of Fisher (1959) and Buehler (1959) discuss the importance of conditioning on recognizable subsets of the sample space. The stopping time yields an easily identifiable partition of the sample space when considering group sequential testing. We first present confidence intervals that are correct when conditioning on the subset of data for which a trial stopped at a particular analysis. These intervals have very desirable properties for observations that are highly unusual (given any value of the mean). In addition, they provide insight into how information about the mean is distributed between the two sufficient statistics. We then use conditional coverage probabilities to compare the sample mean, stagewise, and repeated confidence intervals. We find that none of these intervals outperforms the others when conditioning on stopping time, and no interval is a uniformly acceptable performer.
A study of cores in a complete sample of radio sources

The high resolution provided by the Parkes-Tidbinbilla real-time interferometer (PTI) has been used to measure the core flux density for a complete sample of radio sources. Lower resolution maps are already available for most of these objects together with optical (spectroscopic) data. The new data show that an inverted spectral index 0( '" - 0.3 (S ex: v-a) could be characteristic of all the nuclei, going from low-luminosity radio galaxies to powerful quasars. Taking this spectral index into account, the measured flux density does not change very much, going from a scale of tens of kpc (corresponding to the low-resolution observations) to the sub kpc scale of the new observations. Thus, most of the flux observed in the central region originates in a sub-kpc area. With the new PTI data we obtain a better estimate of the radio core dominance (R), i.e. the ratio between the core and the extended radio flux. This parameter is claimed to be a good indicator of the orientation of the beamed radiation with respect to the line of sight, and hence a very important parameter for testing 'unified schemes' for active galactic nuclei (AGN). Using this parameter, together with optical spectroscopic information, we find that the radio core dominance shows different distributions . for different radio and optical characteristics. A statistically significant difference in the distribution of R is observed between Fanaroff - Riley (FR) I and FR II radio galaxies, supporting the idea that low-power sources are less affected by beaming because they have, on average, a lower Lorentz factor. Among the FR II radio galaxies, narrow-line radio galaxies (NLRGs) show lower values of R while the broad-line radio galaxies (BLRGs) have the largest R. Moreover, the median value of R for BLRGs is lower than for steep-spectrum quasars (SSQ) even after a number of selection effects are taken into account. This result can be explained in the framework of unified schemes for AGN assuming that in the BLRGs we are seeing more directly into the nucleus, although not as much as in SSQs.
Stabilizability of nonminimum phase unstable plants with arbitrary multiplicity over AWGN channels

In the present paper we obtain the infimal signal-to-noise ratio (SNR) required for the stabilizability of a linear output feedback loop over an additive white Gaussian noise (AWGN) channel in closed-form. The focus on AWGN channels allow us to then define the minimal channel capacity required for stabilizability. Finally, the infimal SNR for stabilizability also allow us to identify in closed-form the related stabilizing Hermitian positive semidefinite solution to the continuous-time algebraic Riccati equation of LQ control with vanishing state weight and repeated eigenvalues.
A NOTE ON THE MAXIMUM LIKELIHOOD ESTIMATION OF REGRESSION MODELS WITH FIRST ORDER MOVING AVERAGE ERRORS WITH ROOTS ON THE UNIT CIRCLE

Summary This note gives an alternative derivation of Sargan and Bhargava’ s results concerning the probability of observing on the unit circle a local maximum of the likelihood function of regression models with first order moving average errors. The note also discusses the relevance of these results for the computation of the exact maximum likelihood estimation of regression models with moving average errors.
Comment on ''Grain boundary ridge on sintered bonds between ice crystals'' †J. Appl. Phys. 90, 5782 "2001…‡

Ridges have been observed at the bonds between sintering snow grains. Images collected using the scanning electron microscope (SEM) and x-ray analysis of Antarctic snow are presented. These indicate the ridges are composed from soluble impurity and not ice or water as previously suggested. The ridges can be explained by the coagulation of soluble impurities distributed either at the grain boundaries or on the grain surface. Coagulation is most likely to occur as a result of sublimation during the preparation of the snow specimens for SEM examination, however, they could also form under specific temperature conditions in the snow pack. Consequently, a theory of grain boundary diffusion is not required to explain the presence of ridges at snow bonds.
Some properties of order statistic filters

Let X1, X2, . be a stationary sequence of random variables with Pr(Xt less than or equal to x) = F(x), t = 1, 2, . Also let Xi:n(t), i = 1, . , n, denote the i-th order statistic (OS) in the moving sample (Xt-N, ., Xt, ., Xt+N) of odd size n = 2N + 1. Then Yt = (summation)aiXi:n(t) with (summation)ai = 1 is an order statistics filter. In practice ai greater than or equal to 0, i = 1, . , n. For t > N, the sequence (Yt) is also stationary. If X1, X2, . are independent, the autocorrelation function ρ(r) = corr(Yt, Tt+r) is zero for r > n-1 and for r less than or equal to n-l can be evaluated directly in terms of the means, variances, and covariances of the OS in random samples of size n + r from F(x). In special cases several authors have observed that (Yt) produces a low-pass filter. It will be shown that this result holds generally under white noise. The effect of outliers (impulses) is also discussed.
Improved metal–oxide–nitride–oxide–silicon-type flash device with high-k dielectrics for blocking layer

We have investigated a sputter-deposited Al2O3/HfO2 stack as a blocking layer of metal–oxide–nitride–oxide–silicon capacitors. Compared with a SiO2 blocking layer, the sample with Al2O3/HfO2 stack shows lower write/erase (W/E) voltage, higher speed, and longer data retention time. The improvement of electrical characteristics can be explained by lower leakage current density and less voltage drop of high-k blocking layer which in turn increase the effective thickness of tunneling oxide. After stressing the W/E voltage of ±10 V voltage for 1 ms, the flat-band voltage shift of 4 V and 10 years of retention time was obtained.
Shear thickening in steady and superposition flows effect of particle interaction forces

The phenomenon of shear thickening has been studied in sterically stabilized colloidal suspensions. Temperature has been used to vary the solvent quality of the suspending medium for the grafted polymer in the stabilizer layer. A decrease in temperature causes the polymer coat to shrink. This results in a lower viscosity in the shear thinning region but also in a lower critical shear rate and shear stress at the onset of shear thickening. The critical shear stress increases with increasing particle volume fraction, at least for the volume fractions studied here. In large amplitude oscillatory flow, strain hardening for both storage and loss moduli sets in at the same peak shear rate that causes shear thickening in steady state flow. Parallel superposition also has been used to probe the effect of the stabilizer layer. The frequency dependence of the superposition moduli changes drastically once shear thickening sets in. Surprisingly, this produces a simple and constant shape for the moduli-frequency curve.
Exponential stability of stochastic switched systems

This paper proposes a method for exponential m-stability analysis of stochastic switched systems. The models, in a finite set of models, are non-linear stochastic models. It is assumed that there is no jump in the state at switching instants and there is no Zeno behaviour, ie, there is finite number of switches on every bounded interval. The stochastic hybrid systems have wide applications: transmission control protocol flows with congestion avoidance and slow-start modes; estimation in distributed networked systems; air traffic control; process control and communication networks for control systems. For analysis of stochastic switched system the multiple Lyapunov functions are used and exponential m-stability is proved. From the main result of the paper: 1) the exponential m1 -stability of stochastic switched systems whereby m1 ∈ (0, m); 2) the stability in probability. The exponentially stable equilibrium of system is relevant for practice because such systems are robust to perturbations.
Gain-scheduled control of switched systems subject to actuator saturation

A new technique is presented for the design of gain-scheduling controllers for switched systems with actuator saturation. By using the parametric Lyapunov equation-based approach and the invariant set theory, we develop a switching strategy of the whole system and propose a gain scheduling approach to increase the design parameter online. Then the closed-loop system is proven to be exponentially stable. Numerical simulations show the effectiveness of the proposed gain scheduling approaches.
Generalized Projective Synchronization of Diverse Structures Hyperchaotic Systems with Unknown Parameters

In this paper, the generalized projective synchronization for a general class of hyperchaotic systems is investigated. A systematic, powerful and concrete scheme is developed to investigate the generalized projective synchronization between the drive system and response system based on the feedback control approach. The hyperchaotic Chen system and hyperchaotic Lorenz system are chosen to illustrate the proposed scheme. Numerical simulations are provided to show the effectiveness of the proposed schemes.
Characterization of architectural distortion on mammograms using a linear energy detector

Architectural distortion is a breast cancer sign, characterized by spiculated patterns that define the disease malignancy level. In this paper, the radial spiculae of a typical architectural distortion were characterized by a new strategy. Firstly, previously selected Regions of Interest are divided into a set of parallel and disjoint bands (4 pixels the ROI length), from which intensity integrals (coefficients) are calculated. This partition is rotated every two degrees, searching in the phase plane the characteristic radial spiculation. Then, these coefficients are used to construct a fully connected graph whose edges correspond to the integral values or coefficients and the nodes to x and y image positions. A centrality measure like the first eigenvector is used to extract a set of discriminant coefficients that represent the locations with higher linear energy. Finally, the approach is trained using a set of 24 Regions of Interest obtained from the MIAS database, namely, 12 Architectural Distortions and 12 controls. The first eigenvector is then used as input to a conventional Support Vector Machine classifier whose optimal parameters were obtained by a leave-one-out cross validation. The whole method was assessed in a set of 12 RoIs with different distribution of breast tissues (normal and abnormal), and the classification results were compared against a ground truth, already provided by the data base, showing a precision rate of 0.583%, a sensitivity rate of 0.833% and a specificity rate of 0.333%.
Role of trigger to avoid current quenching in pseudospark switch

In this paper, experiments have been reported on finding a possible solution to the current quenching problem in the pseudospark switch (PSS). The charge injection trigger system has been used to investigate this aspect. Trigger current pulses with varying duration and varying charge content have been used for injection of charge from a single dielectric trigger unit into the hollow cathode geometry of the PSS. Quenching has been suppressed in the PSS by optimizing the triggered charge content. This approach has the advantage of using existing switch technologies as well as assemblies for solving the current quenching problem. Possibilities for further work on triggered charge in hollow cathode geometry have been outlined.