Miracle-dz/UniFAR-FTUs huggingface dataset:
The average impulse response of a rough surface and its applications

This paper is concerned with the theoretical model for short pulse scattering from a statistically random planar surface with particular application to current state of the art radar altimetry, A short review of the assumptions inherent in the convolational model is presented. Simplified expressions are obtained for both the impulse response and the average backscattered power for near normal incidence under the assumptions common to satellite radar altimetry systems. In particular, it is shown that the conventional two-dimensional surface integration can be reduced to a closed form solution. Two applications of these results are presented relative to radar altimetry, namely, radar antenna pointing angle determination and altitude bias correction for pointing angle and surface roughness effects. It is also shown that these results have direct application to the analysis of the two frequency system proposed by Weissman, and a possible combined long pulse altimeter and two frequency system is suggested.
Fabrication of GaN‐Based Resonant Cavity LEDs

This article describes a fabrication process for GaN based resonant cavity (RC) LEDs. The devices emit through the transparent sapphire substrate. An AlGaN/GaN DBR forms the bottom mirror, while a PdAg-based p-contact metallisation serves as top mirror. The PdAg mirrors have been characterized optically by reflectometry, and electrically by circular TLM measurements. A specific contact resistivity of 1.0 × 10 -2 Ωcm 2 has been measured, without any annealing of the contacts. For the GaN to PdAg interface a reflectivity of 60% has been measured for a wavelength of 510 nm. At 20 mA bias the RC-LEDs show a forward voltage of 3.5 V and an optical output of 330 μW through the back of the wafer.
A modified algorithm for continuous wave near infrared spectroscopy applied to in-vivo animal experiments and on human skin

Continuous wave Near Infrared Spectroscopy is a well known non invasive technique for measuring changes in tissue oxygenation. Absorption changes (&Dgr;O2Hb and &Dgr;HHb) are calculated from the light attenuations using the modified Lambert Beer equation. Generally, the concentration changes are calculated relative to the concentration at a starting point in time (delta time method). It is also possible, under certain assumptions, to calculate the concentrations by subtracting the equations at different wavelengths (delta wavelength method). We derived a new algorithm and will show the possibilities and limitations. In the delta wavelength method, the assumption is that the oxygen independent attenuation term will be eliminated from the formula even if its value changes in time, we verified the results with the classical delta time method using extinction coefficients from different literature sources for the wavelengths 767nm, 850nm and 905nm. The different methods of calculating concentration changes were applied to the data collected from animal experiments. The animals (lambs) were in a stable normoxic condition; stepwise they were made hypoxic and thereafter they returned to normoxic condition. The two algorithms were also applied for measuring two dimensional blood oxygen saturation changes in human skin tissue. The different oxygen saturation levels were induced by alterations in the respiration and by temporary arm clamping. The new delta wavelength method yielded in a steady state measurement the same changes in oxy and deoxy hemoglobin as the classical delta time method. The advantage of the new method is the independence of eventual variation of the oxygen independent attenuations in time.
A time-domain simulation of an oscillating water column with irregular waves

A time-domain simulation of a land-based Oscillating Water Column (OWC) with various irregular waves as a form of PM spectrum is performed by using a two-dimensional fully nonlinear numerical wave tank (NWT) based on the potential theory, mixed Eulerian-Lagrangian (MEL) approach, and boundary element method. The nonlinear free-surface condition inside the OWC chamber was specially devised to describe both the pneumatic effect of the time-varying pressure and the viscous energy loss due to water column motions. The quadratic models for pneumatic pressure and viscous loss are applied to the air and free surface inside the chamber, and their numerical results are compared with those with equivalent linear ones. Various wave spectra are applied to the OWC system to predict the efficiency of wave-energy take-off for various wave conditions. The cases of regular and irregular waves are also compared.
Broadband log-periodogram regression of time series with long-range dependence

This paper discusses the properties of an estimator of the memory parameter of a stationary long-memory time-series originally proposed by Robinson. As opposed to narrow-band estimators of the memory parameter (such as the Geweke and Porter-Hudak or the Gaussian semiparametric estimators) which use only the periodogram ordinates belonging to an interval which degenerates to zero as the sample size n increases, this estimator builds a model of the spectral density of the process over all the frequency range, hence the name, broadband. This is achieved by estimating the short-memory component of the spectral density, f * (x) = = 1 - e ix | 2d f(x), where d ∈ (-1/2,1/2) is the memory parameter and f(x) is the spectral density, by means of a truncated Fourier series estimator of log f * Assuming Gaussianity and additional conditions on the regularity of f * which seem mild, we obtain expressions for the asymptotic bias and variance of the long-memory parameter estimator as a function of the truncation order. Under additional assumptions, we show that this estimator is consistent and asymptotically normal. If the true spectral density is sufficiently smooth outside the origin, this broadband estimator outperforms existing semiparametric estimators, attaining an asymptotic mean-square error O(log(n)/n).
A methanol line survey toward high-mass star-forming regions

We present the results of a search for methanol maser and thermal lines in 11 transitions in the range 85-112 GHz toward 23 star-forming regions exhibiting class I and class II methanol masers. The selected frequencies are 85.5, 86.6, 94.5, 95.1, 96.7 (quartet line series), 107.0, 108.8 and 111.2 GHz. Five masers were confirmed at 107.0 GHz while new masers were found at 85.5, 86.6 and 108.8 GHz. Many detected emission lines have a quasi-thermal origin. The detection rates of methanol emission are high at 95.1 GHz (87%) and 96.7 GHz (96%), satisfactory at 107.0 and 108.9 GHz (~$50\%$) while the detection rates at 85.5, 94.5 and 111.3 GHz are low (~$20\%$). Most reported 95.1 GHz emission is masing.
Information and mixtures of two normal distributions

The information available for estimating the parameters of a mixture of two normal distributions is examined for five different types of sample. The information in these samples is compared through the asymptotic relative efficiencies of the maximum likelihood estimates using both generalized and total variances. The efficiency of the maximum likelihood estimates is increased substantially if the component of origin of a small proportion of the sample is known. Guidelines are suggested for choosing the best type of sample.
Robust fault detection for continuous-time switched delay systems: an linear matrix inequality approach

This study addresses the robust fault detection problem for continuous-time switched systems with state delays. The fault detection filter is used as the residual generator depending on the system mode. Attention is focused on designing the filter such that, for the modelling errors, the unknown inputs and the control one, the error between the residuals and the faults is minimised. The addressed fault detection filter design is converted into an auxiliary H ? filtering problem. By using the Lyapunov-Krasovskii functional method and average dwell time approach, a sufficient condition for the solvability of this problem is established in terms of linear matrix inequalities (LMIs). Two examples are provided to demonstrate the effectiveness of the proposed method.
Circumstellar CO in OH/IR Stars Close to the Galactic Centre

A pilot project is carried out to measure circumstellar CO emission from three OH/IR, stars close to the GC using the Nobeyama Millimeter Array at 115 GHz and the Sub-Millimeter Array at 230 GHz. An interferometer is necessary as a 'spatial filter' in this region of space because of the confusion with interstellar CO emission. The intention is to find out whether it is possible to later conduct a large-scale survey for mass-loss rates using, for example, ALMA. Thus an important parameter would be added to our understanding of the evolution of the Galactic Bulge. Sources have been detected towards two of the stars with 'correct' positions and radial velocities. However, for one of the stars the line profile is not what one expects for expanding circumstellar envelopes. This surprising result is discussed and our plans for future observations are presented.
The new SCOS-based EGSE of the EPIC flight-spare on-ground cameras

The XMM-Newton observatory, launched by the European Space Agency in 1999, is still one of the scientific community’s most important high-energy astrophysics missions. After almost 15 years in orbit its instruments continue to operate smoothly with a performance close to the immediate post-launch status. The competition for the observing time remains very high with ESA reporting a very healthy over-subscription factor. Due to the efficient use of spacecraft consumables XMM-Newton could potentially be operated into the next decade. However, since the mission was originally planned for 10 years, progressive ageing and/or failures of the on-board instrumentation can be expected. Dealing with them could require substantial changes of the on-board operating software, and of the command and telemetry database, which could potentially have unforeseen consequences for the on-board equipment. In order to avoid this risk, it is essential to test these changes on ground, before their upload. To this aim, two flight-spare cameras of the EPIC experiment (one MOS and one PN) are available on-ground. Originally they were operated through an Electrical Ground Support Equipment (EGSE) system which was developed over 15 years ago to support the test campaigns up to the launch. The EGSE used a specialized command language running on now obsolete workstations. ESA and the EPIC Consortium, therefore, decided to replace it with new equipment in order to fully reproduce on-ground the on-board configuration and to operate the cameras with SCOS2000, the same Mission Control System used by ESA to control the spacecraft. This was a demanding task, since it required both the recovery of the detailed knowledge of the original EGSE and the adjustment of SCOS for this special use. Recently this work has been completed by replacing the EGSE of one of the two cameras, which is now ready to be used by ESA. Here we describe the scope and purpose of this activity, the problems faced during its execution, the adopted solutions, and the tests performed to demonstrate the effectiveness of the new EGSE.
Automated assembly of VECSEL components

Due to the architectural advantage of an external cavity architecture that enables the integration of additional elements into the cavity (e.g. for mode control, frequency conversion, wavelength tuning or passive mode-locking) VECSELs are a rapidly developing laser technology. Nevertheless they often have to compete with direct (edge) emitting laser diodes which can have significant cost advantages thanks to their rather simple structure and production processes. One way to compensate the economical disadvantages of VECSELs is to optimize each component in terms of quality and costs and to apply more efficient (batch) production processes. In this context, the paper presents recent process developments for the automated assembly of VECSELs using a new type of desktop assembly station with an ultra-precise micromanipulator. The core concept is to create a dedicated process development environment from which implemented processes can be transferred fluently to production equipment. By now two types of processes have been put into operation on the desktop assembly station: 1. ) passive alignment of the pump optics implementing a camera-based alignment process, where the pump spot geometry and position on the semiconductor chip is analyzed and evaluated; 2. ) active alignment of the end mirror based on output power measurements and optimization algorithms. In addition to the core concept and corresponding hardware and software developments, detailed results of both processes are presented explaining measurement setups as well as alignment strategies and results.
On cardinality of the set of alternatives in discrete many-criterion problems

Under many-criterion formulations of well-known extremal problems (the chain problem, the matching problem, the travelling salesman problem, etc.) we obtain lower bounds for the cardinalities of the Pareto set and the complete set of alternatives. Probability analysis of the structures of these sets is fulfilled, and it is proved that the bounds are exponential for almost all graphs.
Nonresonant fifth-order nonlinearities induced by ultrashort intense pulses

We demonstrate the existence of χ(5) nonlinearities induced in a transparent glass by intense femtosecond pulses at 620 nm. Polarization selectivity associated with a transient-grating technique allows us to discriminate this contribution from the electronic third-order one. A value of 5 is measured for the ratio between symmetric and nonsymmetric elements for this fifth-order susceptibility. This value corresponds to the expected value deduced from the anharmonic model presented and is definitely attributed to a direct six-wave mixing process.
A hybrid one-step inversion method for shear modulus imaging using time-harmonic vibrations

We propose a hybrid inversion method for imaging the shear modulus μ in tissue-like subjects using internal measurement of the displacement u induced by an external low-frequency mechanical vibrations made on the boundary of the subject. The proposed method is designed to provide high-resolution imaging in a heterogeneous subject, with no need for an iterative procedure, and deal with the intrinsically noisy displacement data. We recover the shear modulus μ by decomposing it into two components: one is for capturing the main feature of μ using a relatively noise-insensitive inversion method, and the other is to correct the residual caused by the quantity ∇μ × ∇u. Numerical simulations show that the proposed method significantly improves reconstructions without requiring boundary conditions.
Final report of key comparison CCM.P-K12 for very low helium flow rates (leak rates)

Quantitative leak tests with vacuum technology have become an important tool in industry for safety and operational reasons and to meet environmental regulations. In the absence of a relevant key comparison, so far, there are no calibration measurement capabilities published in the BIPM data base. To enable national metrology institutes providing service for leak rate calibrations to apply for these entries in the data base and to ensure international equivalence in this field, key comparison CCM.P-K12 was organized. The goal of this comparison was to compare the national calibration standards and procedures for helium leak rates. Two helium permeation leak elements of 4×10−11 mol/s (L1) and 8×10−14 mol/s (L2) served as transfer standards and were measured by 11 national metrology institutes for L1 and 6 national metrology institutes for L2. Equivalence could be shown for 8 laboratories in the case of L1 and for all 6 in the case of L2. Three different evaluation methods were applied and are presented in this report, but the random effects model was accepted as most suitable in our case. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm. org/. The final report has been peer-reviewed and approved for publication by the CCM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Polarization-independent optical spectral inversion without frequency shift using a single semiconductor optical amplifier

Two schemes for polarization-independent spectral inversion without frequency shift have been experimentally demonstrated. Both schemes use two pump beams and a polarization-insensitive semiconductor amplifier. Polarization-independent optical spectral inversion without frequency shift was obtained for lower wavelength detuning between the two pump beams in the first scheme and for large wavelength detuning in the second scheme. Combining these two schemes allows polarization-independent spectral inversion without frequency shift to be obtained over a quite wide frequency range. The results are in good qualitative agreement with theoretical predictions.
Wide-field telescope design for the KMTNet project

The Korea Astronomy and Space Science Institute (KASI) are under development three 1.6m optical telescopes for the Korea Micro-lensing Telescope Network (KMTNet) project. These will be installed at three southern observatories in Chile, South Africa, and Australia by middle 2014 to monitor dense star fields like the Galactic bulge and Large Magellanic Cloud. The primary scientific goal of the project is to discover numerous extra-solar planets using the gravitational micro-lensing technique. We have completed the final design of the telescope. The most critical design issue was wide-field optics. The project science requires the Delivered Image Quality (DIQ) of less than 1.0 arcsec FWHM within 1.2 degree radius FOV, under atmospheric seeing of 0.75 arcsec. We chose the prime-focus configuration and realized the DIQ requirement by using a purely parabolic primary mirror and four corrector lenses with all spherical surfaces. We present design results of the wide-field optics, the primary mirror coating and support, and the focus system with three linear actuators on the head ring.
Determination of dynamical critical exponents from hysteresis scaling

A method is proposed to determine the dynamical critical exponent. The method is based on the scaling for dynamical hysteresis resulted from a linearly swept field. We prove that in model $A$ dynamical hysteresis scaling at critical temperature is universal. The nearest-neighbor Ising models are used to demonstrate such concepts and the dynamical critical exponents can be determined accurately. We also propose a universal relation between static and dynamical critical exponents in Ising class in single-spin-flip dynamics.
Covariance and survivor function estimation using censored multivariate failure time data

SUMMARY The covariance between counting process martingales is used to characterize the dependence between two failure time variates. A representation of the bivariate survivor function is obtained in terms of the marginal survivor functions and this covariance function. A closely related representation expresses the bivariate survivor function in terms of marginal survivor functions and a conditional covariance function, leading to a new nonparametric survivor function estimator. Generalizations to higher dimensional failure time variates are also given. Simulation evaluations of the survivor function estimator are presented, and generalizations to regression problems are outlined.
Singular value decomposition combined with wavelet transform for LCD defect detection

Singular value decomposition is used to obtain the mean value of the first and second singular value ratios of normal and defect LCD images. Then the third and fourth singular values matched with the standard deviation of the first two singular value ratios are used to divide the defect images into two categories: coarse and fine. Finally, 2D discrete wavelet coefficient filtering combined with region growing is adopted to extract defect regions.
Gapless state in CuFeS2

A theoretical group analysis of the CuFeS2 structure is made in the presence of magnetic order. It is shown that in such a structure a gapless state may obtained at a point P of the Brillouin zone of chalcopyrite. The existence of ferron states is pointed out. A construction is made of a ferron state corresponding to the specified irreducible representation of the wave vector group of point P of the Brillouin zone. As a result of the analysis the conclusion is made that CuFeS2 refers to gapless magnetic semiconductors where the gapless state is materialized at the boundary of the Brillouin zone and corresponds to a special case of spatial symmetry. In addition, the gapless state appears to be implemented not in usual but in ferron bands. The existence of a ferron hole is predicted. It is pointed out that the gapless state in CuFeS2 corresponds to the first type gapless state according to the character of the temperature dependence of concentration. [Russian Text Ignored]
Acoustic attenuation in fluid‐saturated porous cylinders at low frequencies

Laboratory measurements on the elastic moduli and the acoustic attenuation of fluid‐saturated porous rock cylinders are frequently affected by the boundary conditions of the rock sample, i.e., whether the curved surface of the cylindrical sample is exposed to air or properly sealed. In this paper, the analytical solutions of these problems for the extensional, torsional, and flexural modes are derived, and several numerical examples are computed. It was found that there exists an ‘‘artificial’’ attenuation caused by the open‐pore boundary condition, whose relaxation frequency, in the case of extensional mode, is directly proportional to the permeability of the rock and inversely proportional to the viscosity of the pore fluid and the square of the sample radius. This attenuation exists in both the extensional and the flexural modes but not in the torsional mode.
Utility conditionals as consequential arguments: A random sampling experiment

Research on reasoning about consequential arguments has been an active but piecemeal enterprise. Previous research considered in depth some subclasses ofconsequential arguments, but further understanding of consequential arguments requires that we address their greater variety, avoiding the risk of over-generalisation from specific examples. Ideally we ought to be able to systematically generate the set of consequential arguments, and then engage in random sampling of stimuli within that set. The current article aims at making steps in that direction, using the theory of utility conditionals as a way to generate a large set of consequential arguments, and offering one study illustrating how the theory can be used for the random sampling of stimuli. Itis expected that further use of this method will bring more diversity to experimental research on consequential arguments, and more robustness to models of argumentation from consequences.