Miracle-dz/UniFAR-FTUs huggingface dataset:
Relativity and quantum theory from Sommerfeld to Dirac

Quantum theory and the special theory of relativity emerged almost simultaneously. Through the formative years of quantum theory, from 1900 to about 1928, arguments based on the theory of relativity were of great importance. Starting with Sommerfeld's theory of the hydrogen atom, this paper surveys the ways in which the two fundamental theories have interacted. Relativity was of particular importance in Schrödinger's route to wave mechanics, a theory which was originally conceived as fully integrated with special relativity. The problem of uniting, or harmonising, quantum mechanics and relativity continued to occupy physicists in 1926–27. The paper ends with the solution of this problem, as it was presented in 1928 by Dirac in his seminal paper on the quantum theory of electrons. It also refers to the few attempts there were in the period to formulate a quantum theory in agreement with the general theory of relativity.
The Theory of Elastic Waves and Waveguides

various geometries (mostly two-dimensional and some three-dimensional) under several loading conditions. There are 22 such figures and 20 tables in Nisitani's text while eight figures in Bowie-Freese's text. These are worthwhile and useful as suppliments to Peterson's Table of Stress Concentration and to Tada-Paris-Irwin's Cracks Handbook Even though the editor stated in the preface that "The finite-element method has been purposely left out, for it is now becoming common procedure in cases too complex for analysis," one cannot justify the omission of the finite-element method in view of its importance in this class of problems with recent progress of hybrid finite-element methods where singularities at the crack tips are properly carried into the analysis. The reviewer also feels that the usefulness of the book will be enhanced if it includes an article which emphasizes behavior (asymptotic or boundedness) of these factors upon geometrical parameters rather than solution methods along the lines of the article by Benthem and Koiter in the first volume of the series.
Sobolev estimates for singular Radon transforms

Abstract Singular Radon transforms of order α are defined. For each α ∈ R , a model transform R α on RP n for n odd is considered. Generalizing earlier results by the author ( Comm. Partial Differential Equations 14, 1989, 1461-1470), sharp Sobolev estimates, both upper bounds and lower bounds, are given. In particular, R α is injective for all α not equal to a certain critical value. Using a result in microlocal analysis known as the "parabolic trick," Sobolev upper bounds are proved for quite general singular Radon transforms. These are consistent with the upper bounds found in the model case. In addition, a microlocal description of the critical value of α is found. For α a non-negative even integer, it is shown that the lower bounds continue to hold for transforms "close" to the model transform.
COMETARY ACTIVITY IN DISTANT COMETS: CHIRON

Activity in distant comets is one of the most poorly understood topics of cometary studies, but fortunately we now know of a few bright, active distant comets that serve as ideal case studies. Perhaps the best example of these comets is the object 2060 Chiron, a very large comet which started showing signs of activity as distant from the Sun as R=12 AU. Here we summarize recent results on Ciron, culled from our ongoing program to monitor this unusual object. Photometric data gathered in the period 1989-1992 showed that Chiron was capable of short, steep brightening trends (outbursts) in addition to the already known long-term outbursts. The coma is optically thin and gradually dilutes light scattered from the nucleus as the coma grows in strength. The coma also possesses variable surface brightness profiles which change according to the level of nuclear activity. The outbursts and the variable surface brightness profiles appear to be common characteristics of active distant comets.
Robust Estimation of Skewness and Kurtosis in Distributions with Infinite Higher Moments

This paper studies the behavior of the conventional measures of skewness and kurtosis when the data generator process is a distribution which does not possess variance or third or fourth moment and assesses the robustness of the alternative measures for these particular cases. It is first shown that for symmetric fat-tailed distribution skewness is far from being a valid indicator of the presence of asymmetry. Secondly, a Monte Carlo simulation is performed to investigate the behavior of the alternative measures of skewness and kurtosis when applied to distributions which do not possess finite higher moments. Finally, an application to the series of daily returns on a large cap US stock is presented to explain why alternative measures are a better tool to describe the distribution of financial returns.
Energy-band alignment of HfO2/SiO2/SiC gate dielectric stack

The band alignment of HfO2∕SiO2∕SiC gate dielectric stack has been investigated by x-ray photoelectron spectroscopy and electrical characterization. Two types of valence band offsets are observed in the stack layer; the smaller value of 1.5eV corresponds to the HfO2∕SiC band offset while the larger one of 2.2eV is due to the interfacial SiO2∕SiC. The barrier height is extracted to be 1.5eV from the Schottky emission characteristics and is higher than the reported value for HfO2 on SiC without interfacial SiO2. Thus, presence of an interfacial SiO2 layer increases band offsets to reduce the leakage current characteristics.
Analysis of Convergence Boundaries Observed during IHOP_2002

Abstract An analysis of six convergence boundaries observed during the International H2O Project (IHOP_2002) is presented. The detailed kinematic and thermodynamic structure of these boundaries was examined using data collected by an airborne Doppler radar and a series of dropsondes released by a jet flying at ∼500 mb. The former and latter platforms were able to resolve the meso-γ- and meso-β-scale circulations, respectively. Convection initiated on three of the days while no storms developed in the regions targeted by the mobile platforms on the other days (referred to as null cases). The airborne radar resolved the finescale structure of four drylines, a cold front, and an outflow boundary on the six days. Horizontal profiles through radar-detected thin lines revealed “bell-shaped distributions” and there appeared to be a seasonal dependence of the peak values of radar reflectivity. The echo profiles through the fine line in May were, in general, greater than those plotted for the June cases. There was.
Energy Distribution and Cooling Effect of Electrons Emitted from an Arc Cathode

The energy distribution and the average cooling effect of electrons emitted by the T‐F process are calculated over a wide range of temperatures and electric fields for several values of work functions. It is shown that at low temperatures, the average cooling effect approaches zero and at high temperatures, it is approximately equal to the reduced work function. The limitation of the validity of reduced work function can be easily seen.
Improvement of grain size and deposition rate of microcrystalline silicon by use of very high frequency glow discharge

The influence of the plasma excitation frequency on the growth conditions and the material properties of microcrystalline silicon prepared by plasma enhanced chemical vapor deposition at low deposition temperature is investigated. It is found that an increase of the plasma excitation frequency leads to a simultaneous increase of the growth rate, the grain size, and the Hall mobility of microcrystalline silicon. This is attributed to an effective selective etching of disordered material creating more space to develop crystalline grains, while also more species for faster growth of the crystallites are available.
An Error Analysis on Images Using Skeletonization Methods

Vectorization is the most fundamental operation in interpretation of line drawings and document analysis. There are several reasons for converting image vectorization. Vector data is normally created from existing natural source image like photographs,scanned images. Choosing a best vectorization method that suits the needs of the system is very important. In general, good methods must preserve information like line geometry and intersection junction as far as possible. It is also important to analyze the error and find the accuracy of the result with respect to the original data. We have compared Skeletonization by Mathematical Morphology and Voronoi Diagrams with original image for vectorizing images. Root mean squre error is one of the good methods to analysis an error on original Image, Mathematical Morphology and Voronoi Diagrams. Literature about above said methods is also included in this paper.
Far-infrared observations of Sagittarius B2: reconsideration of source structure

New moderate-angular-resolution far-infrared observations of the Sagittarius B2 star-forming region are presented, discussed, and compared with recent radio molecular and continuum observations of this source. In contrast to previous analyses, its far-infrared spectrum is interpreted as the result of a massive frigid cloud overlying a more-or-less normal infrared source, a natural explanation for the object's previously-noted pecularities. The characteristics derived for the obscuring cloud are similar to those found for the W51 MAIN object. Both sources have high sub-millimeter surface brightness, a high ratio of sub-millimeter to far-infrared flux, and numerous regions of molecular maser emission.
When did Bayesian inference become "Bayesian"?

While Bayes’ theorem has a 250-year history and the method of inverse probability that flowed from it dominated statistical thinking into the twentieth century, the adjective “Bayesian” was not part of the statistical lexicon until relatively recently. This paper provides an overview of key Bayesian developments, beginning with Bayes’ posthumously published 1763 paper and continuing up through approximately 1970, including the period of time when “Bayesian” emerged as the label of choice for those who advocated Bayesian methods.
The Heliospheric He II 30.4 nm Solar Flux During Cycle 23

Because of the orbit characteristics of the vast majority of spacecraft, the solar flux has predominantly been measured at Earth or at least in the plane of the ecliptic. Therefore, the existing data do not directly demonstrate the fact that the latitudinal distribution of the extreme-ultraviolet (EUV) solar flux is largely anisotropic. Indeed, in the EUV the nonuniform distribution of very contrasted bright features (i.e., active regions) and dark features (i.e., coronal holes) at the surface of the Sun produces both the obvious rotational (or longitudinal) modulation of the flux and also a strong latitudinal anisotropy. Although largely ignored up to now, the latitudinal anisotropy affects the physical conditions in the corona and heliosphere and should therefore be taken into account in several solar and heliospheric physics applications. We describe in this paper a technique for computing the He II 30.4 nm flux at an arbitrary position in the heliosphere from Solar and Heliospheric Observatory (SOHO) EUV Imaging Telescope (EIT) images. This procedure was used to produce daily all-sky maps of the 30.4 nm flux from 1996 January to 2003 August, covering the first 8 yr of solar cycle 23. As could be expected from the examination of the EIT images, the 30.4 nm flux was found to be strongly anisotropic. The anisotropy Ipol/Ieq between the fluxes computed for viewpoints located above the solar poles and within the solar equatorial plane ranges from 0.9 at solar minimum to 0.6 at solar maximum. A 20% difference was also discovered between the north and south polar fluxes. The generalization of this technique to other lines of the EUV and far-ultraviolet (FUV) spectrum is discussed.
Search for narrow energy‐shifted lines in AGN spectra in the XMMNewton archive

Thanks to the large effective area and the spectral resolution of current X-ray satellites, the detection of X-ray narrow spectral features in the 5–7 keV band is becoming commonplace in many AGN observations. Such lines, both in emission and in absorption, are mostly interpreted as arising from Iron atoms. When observed with some displacement from their rest frame position, these lines carry the potential to study the motion of circumnuclear gas in AGN, providing a diagnostic of the effects of the gravitational field of the central black hole. These narrow features have been often found with marginal statistical significance. A systematic search for narrow features in type1 AGN is being performed on all spectra available in the XMM-Newton archive with the aim to estimate the significance of the features with Monte Carlo simulations of synthetic spectra. The project and preliminary results are presented. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
ASCA Observations of Soft X-Ray Transients in Quiescence : X1608-52 and CEN X-4

We observed soft X-ray transients, X1608-52 and Cen X-4, in quiescence with ASCA at X-ray luminosities on the order of 10^(32- 33) erg s^(-1). The energy spectra were rather soft for both sources. Blackbody fits to the data required characteristic temperatures of 0.2-0.3 keV and emission regions of ~10 km^2. A conspicuous hard tail remained after fitting Cen X-4 with a blackbody curve. An extremely soft spectrum in quiescence seems to be a common property of soft X-ray transients.
A hierarchical modelling framework for identifying unusual performance in health care providers

A wide variety of statistical methods have been proposed for detecting unusual performance in cross‐sectional data on health care providers. We attempt to create a unified framework for comparing these methods, focusing on a clear distinction between estimation and hypothesis testing approaches, with the corresponding distinction between detecting ‘extreme’ and ‘divergent’ performance. When assuming a random‐effects model the random‐effects distribution forms the null hypothesis, and there appears little point in testing whether individual effects are greater or less than average. The hypothesis testing approach uses p‐values as summaries and brings with it the standard problems of multiple testing, whether Bayesian or classical inference is adopted. A null random‐effects formulation allows us to answer appropriate questions of the type: ‘is a particular provider worse than we would expect the true worst provider (but still part of the null distribution) to be'? We outline a broad three‐stage strategy of exploratory detection of unusual providers, detailed modelling robust to potential outliers and confirmation of unusual performance, illustrated by using two detailed examples. The concepts are most easily handled within a Bayesian analytic framework using Markov chain Monte Carlo methods, but the basic ideas should be generally applicable.
Global attractor for heat convection problem in a micropolar fluid

The article is devoted to describe asymptotics in the heat convection problem for a micropolar fluid in two dimensions. We show the existence and the uniqueness of global in time solutions and then prove the existence of a global attractor for considered model. Next, the Hausdorff dimension of the global attractor is estimated. Copyright © 2006 John Wiley & Sons, Ltd.
The smart Peano fluidic muscle: a low profile flexible orthosis actuator that feels pain

Robotic orthoses have the potential to provide effective rehabilitation while overcoming the availability and cost constraints of therapists. These orthoses must be characterized by the naturally safe, reliable, and controlled motion of a human therapist's muscles. Such characteristics are only possible in the natural kingdom through the pain sensing realized by the interaction of an intelligent nervous system and muscles' embedded sensing organs. McKibben fluidic muscles or pneumatic muscle actuators (PMAs) are a popular orthosis actuator because of their inherent compliance, high force, and muscle-like load-displacement characteristics. However, the circular cross-section of PMA increases their profile. PMA are also notoriously unreliable and difficult to control, lacking the intelligent pain sensing systems of their biological muscle counterparts. Here the Peano fluidic muscle, a new low profile yet high-force soft actuator is introduced. This muscle is smart, featuring bioinspired embedded pressure and soft capacitive strain sensors. Given this pressure and strain feedback, experimental validation shows that a lumped parameter model based on the muscle geometry and material parameters can be used to predict its force for quasistatic motion with an average error of 10 - 15N. Combining this with a force threshold pain sensing algorithm sets a precedent for flexible orthosis actuation that uses embedded sensors to prevent damage to the actuator and its environment.
THE EFFECT OF WINDS AND OCEAN CURRENTS ON THE ANNUAL VARIATION IN LATITUDE

Abstract An elliptical excursion (mean diameter 20 feet), described annually by the pole of instantaneous rotation over the earth's surface, has been deduced from precise astronomic observations of latitude. According to Jeffreys and Rosenhead, most of this excursion can be ascribed to the seasonal variation in the distribution of matter (air, water, snow and vegetable matter). The most important single factor is the gain, in winter, of air mass over the Asiatic continent, and the corresponding loss over the Atlantic and east Pacific oceans. In this paper, it is shown that the effect of winds may be far from negligible. Here the important factor is the pressure against the Himalayas during the monsoon winds. Ocean currents account for only 1 per cent of the excursion. It is suggested that the latitude observations, together with related astronomic observations concerning an annual change in the length of day, provide a promising method for measuring certain fundamental modes in the annual oscillation of t.
Efficient iterative solution of electromagnetic scattering using adaptive cross approximation enhanced characteristic basis function method

A new hybrid adaptive cross approximation-characteristic basis function method (ACA-CBFM) is proposed to efficiently solve the electromagnetic scattering problems. In the conventional ACA-CBFM, the ACA is only applied to speed up the construction of the reduced matrix that is directly solved and stored. However, with the increase of the size of the targets under analysis, the reduced matrix will become so large that it is difficult to directly solve and store. In this study, the reduced matrix is further compressed by the adaptive cross approximation-singular value decomposition (ACA-SVD) and solved by an iterative method, which leads to reduced storage and accelerated matrix vector product. Furthermore, the ACA-SVD is adapted to efficiently generate the characteristic basis functions (CBFs), which reduces both the time of generating initial CBFs and the SVD time of initial CBFs. Numerical results about the electromagnetic scattering from perfect electric conducting targets are given to demonstrate the merits of the proposed methods.
Simultaneous Occurrence of Different Cloud Types

Abstract Cloud observations from land stations and from ships in the ocean are used to investigate the frequency of observation and the co-occurrence of different cloud types, and the geographical and seasonal variations of these co-occurrences. Ground-based observations are used because they provide a more definitive identification of clouds by type than do satellite observations. The clouds are grouped into six types (cirrus + cirrostratus + cirrocumulus, altostratus + altocumulus, stratus + stratocumulus, nimbostratus, cumulus, and cumulonimbus). The results are expressed as frequency of occurrence of different cloud types and as contingency probabilities; that is, given that one cloud type is present, the probability that another particular type is also present is computed. Several sources of bias are identified, and their effects on the results are estimated. It is found that, on the average at all latitudes and in all seasons, clear skies occur more frequently, by a factor of about 4, over land than.
Some features of the structure of the tropical tropopause

Statistics of the minimum saturation humidity mixing ratio are extracted from 2 500 radiosonde ascents in the tropics (10°N to 10°S) and in the region of the Asian summer monsoon. Two periods of approximately 20 days are examined, one in the northern winter and one in the northern summer. The relation of the observations to an hypothesis, proposed by A. W. Brewer in 1949, of mass exchange between troposphere and stratosphere is briefly discussed.
Choice of Spectral Density Estimator in Ng-Perron Test: A Comparative Analysis

Ng and Perron (2001) designed a unit root test, which incorporates the properties of DF-GLS and Phillips Perron test. Ng and Perron claim that the test performs exceptionally well especially in the presence of a negative moving average. However, the performance of the test depends heavily on the choice of the spectral density estimators used in the construction of the test. Various estimators for spectral density exist in the literature; each have a crucial impact on the output of test, however there is no clarity on which of these estimators gives the optimal size and power properties. This study aims to evaluate the performance of the Ng-Perron for different choices of spectral density estimators in the presence of a negative and positive moving average using Monte Carlo simulations. The results for large samples show that: (a) in the presence of a positive moving average, testing with the kernel based estimator gives good effective power and no size distortion, and (b) in the presence of a negative moving average, the autoregressive estimator gives better effective power, however, huge size distortion is observed in several specifications of the data-generating process.
Novel dual-excitation permanent magnet Vernier machine

A novel dual-excitation permanent magnet Vernier machine; DEPMVM, which has the feature of high torque at low speed, is presented. This machine has two stators both inside and outside of a ring shaped rotor, and its coils are wound around the yokes. These special structures are adopted as a result of detailed investigations of the machines which make use of the so-called 'magnetic gearing effect'. A prototype machine of the DEPMVM is designed and fabricated, and its experimental results indicate the promising nature of the machine.
On the existence of maximum likelihood estimates in logistic regression models

SUMMARY The problems of existence, uniqueness and location of maximum likelihood estimates in log linear models have received special attention in the literature (Haberman, 1974, Chapter 2; Wedderburn, 1976; Silvapulle, 1981). For multinomial logistic regression models, we prove existence theorems by considering the possible patterns of data points, which fall into three mutually exclusive and exhaustive categories: complete separation, quasicomplete separation and overlap. Our results suggest general rules for identifying infinite parameter estimates in log linear models for frequency tables.
Comparison of electron energy-loss and quantitative optical spectroscopy on individual optical gold antennas

Abstract Using a rather large set of different individual metallic optical antennas, we compare directly measured electron energy-loss spectra with measured quantitative optical extinction and scattering cross-section spectra on the identical antennas. All antenna resonances lie near 1.4 µm wavelength. In contrast to other reports, we find identical resonance positions for electrons and photons to within the experimental errors. We discuss possible artifacts which can lead to seemingly different resonance positions in experiments. Our experimental results agree well with complete numerical calculations of both sorts of spectra.