Miracle-dz/UniFAR-FTUs huggingface dataset:
Fabrication and modelling of truncated oblate and prolate microresonators

We have demonstrated softening and micromorphing techniques of amorphous/crystalline materials for fabricating high quality oblate or prolate microresonators. Firstly, “soften-and-compress” technique has been developed for fabricating bottle microresonators from standard fibers or capillaries using splicers. Also, a “soften-and-squash” technique has been demonstrated for fabricating microdiscus resonators by squashing microspheres between glassy-carbon plates. Finally, a softening process was developed for turning crystalline microstructures into predominantly oblate microresonators. We have also developed an efficient transfer-matrix method for calculating resonant frequencies and field distributions in truncated oblate and prolate structures and applied it to analyze resonant characteristics of the new microresonators.
Method for determining individual element misalignments in optical systems

A new method for the misalignments calculation has been developed based in the analysis of the coefficients of the Zernike polynomial adjustment to the on-axis wavefront of the optical system. By means of a study of the system behavior in front of misalignments when they are small perturbations of position around the nominal value, it is shown that the Zernike coefficients behaviour can be aproximated with a polynomial. The coefficients of the Zernike polynomial are used to form a system of non-linear equations where the unknown variables are the misalignment values. This system of equations can be solved to find the misalignments values. The method has been validated by the simulation of a triplet where the second lens is misaligned. A series of misalignments of decentering and tilt have been applied and by simulation the wavefront have been obtained. Then the method has been used to calculate the misalignments from the wavefronts. Good results have been obtained for decentering and tilt separetely. With this process, the error of calculation for the tilt and the decentering has been obatined to be less than 20% for the simulated triplet system.
Stability Conditions Derived from Spectral Theory: Discrete Systems with Periodic Feedback

By use of the spectral theory of linear operators, necessary and sufficient conditions are derived for the stability of a class of discrete time feedback systems with a periodically time-varying feedback gain. These conditions involve a Nyquist plot for an equivalent time-invariant system which may be determined from the frequency response function of the system under consideration. In the special case of a scalar-input scalar-output system, these conditions may be given in a particularly simple form.
Direct imaging and spectroscopy of planets and brown dwarfs in wide orbits†

Abstract Recent direct imaging discoveries of exoplanets have raised new questions about the formation of very low-mass objects in very wide orbits. Several explanations have been proposed, but all of them run into some difficulties, trying to explain all the properties of these objects at once. Here we present the results of a deep adaptive optics imaging survey of 85 stars in the Upper Scorpius young association with Gemini, reaching contrasts of up to 10 magnitudes. In addition to identifying numerous stellar binaries and a few triples, we also found several interesting sub-stellar companions. We discuss the implications of these discoveries, including the possibility of a second pathway to giant planet formation.
Applying population genetics to define the units for conservation management in the European Tree Frog, Hyla arborea

—Population genetic analyses are a powerful tool for obtaining information about cryptic genetic lineages, population structure, and the distribution of intra- and interpopulation genetic diversity across the landscape. This knowledge is crucial for establishing units for the conservation management of endangered species. Species with limited dispersal capacities, such as amphibians, are particularly affected by habitat fragmentation and reductions in gene flow among isolated populations. The European Tree Frog, Hyla arborea , has suffered from dramatic population declines in the last decades and is categorized as Vulnerable to Critically Endangered in its north-western distribution range. In Lower Saxony (Germany), the current distribution of the tree frog is fragmented. In this study, we aimed to assess the population structure, genetic diversity, gene flow, and migration rates in order to define the units for conservation management. Across a distribution area of 250 km 2 , frogs were sampled at 14 localities and genotyped at seven microsatellite loci, and the mt DNA cytochrome b gene was sequenced for a subsample. Whereas microsatellite pairwise D est and F ST values showed genetic differentiation among nearly all sampled populations, Bayesian analyses assigned the 14 localities to two distinct genetic clusters including seven subclusters. Together with a slight correlation between geographic and genetic distance, the population structure indicates ongoing fragmentation. The cytochrome b haplotype distribution does not indicate divergence into mt lineages, but highlights the former connection of populations along the river Elbe. The results of this study suggest that the intense anthropogenic pressures in this area over the last decades have had negative genetic consequences for this species. The fragmented population structure calls for reconnection of the isolated occurrences by the implementation of conservation measures.
Phase noise and spectral line shape in semiconductor lasers

Experimental results concerning the study of phase noise in single-mode semiconductor lasers are reported, which show a strict connection between phase and intensity noise. In particular, phase-noise spectrum is found to present a sharp peak at the same peak frequency of intensity-noise spectrum, a fact which is proven to be responsible for the appearance of satellite peaks in the emission line shape. Direct measurements of the line shape, performed by means of a Fabry-Perot interferometer, are in agreement with the line shape evaluated by using phase-noise spectrum measurements.
A Decade of Aerosol and Gas Precursor Chemical Characterization at Mt. Lemmon, Arizona (1992 to 2002)

Aerosols (PM 2.0 ), and associated precursor gases have been continuously monitored at Mt. Lemmon (2791 m ASL), Arizona, since September 1992. Month-long samples are collected on filters and chemically analyzed resulting in a decade-long record with over 100 data points for each species-among the longest such records currently available. The species determined include SO 2- 4 , NO - 3 , Cl - , NH + 4 , Ca 2+ , Mg 2+ , K + , Na + , elemental carbon (EC), organic carbon (OC), NH 3 (g), SO 2 (g), HCl(g) and HNO 3 (g). The data reveal long-term trends, seasonal variations, and correlations between species. PM 2.0 (1.48 μg m -3 , annual mean) is mainly comprised of SO 2- 4 (49% w/w), NH + 4 (16%), EC (11%) and OC (22%). The mean SO 2- 4 /NH + 4 equivalent ratio is 1:1 suggesting complete neutralization. Median PM 2.0 was 1.33 μg m -3 (range = 0.17-4.32 μg m -3 ). Median EC was 0.14 μg m -3 (0.01-0.76), and median OC was 0.29 μg m -3 (0.03-1.33). The annual mean trends of all species, with the exception of SO 2- 4 , SO 2 (g), NH + 4 and NH 3 (g), appear to be increasing, but some trends may not be statistically significant. Long-term decreasing trends in SO 2 (g) and SO 2- 4 , reflect source controls implemented over the past decade, whereas HNO 3 (g) has been increasing, possibly due to increased NO x emissions associated with population growth in the region. The associated conversion of agricultural land to urban use might be leading to a decrease in NH 3 (g). Annual trends for EC (5.2 ± 2.7 ng m -3 y -1 ) and EC/OC ((1.5 ± 0.75) × 10 -2 y -1 ) appear to be positive and significant, but there is no significant annual OC trend. There appears to be a significant secondary source of OC, presumably derived from photoxidation of biogenic hydrocarbons. There is no significant trend in the calculated annual mean extinction coefficient but the calculated single scattering albedo (ω) may be decreasing (-1.5 ± 1.1 x 10 -3 y -1 ), possibly caused by increasing EC associated with forest fires and/or fossil fuel combustion. Depending on the value of the critical single scattering albedo, the aerosol might already be a net absorber, or it might only become so by the end of the century if current trends continue.
The Panoptic Camera - Plenoptic interpolation in an omnidirectional polydioptric camera

The thesis describes a great new sensor, the Panoptic Camera - a device made of 104 cameras patched on a half sphere. It describes and explains its fundamentals, the reasoning behind and its planned uses. It then covers the whole two-dimensional sparse interpolation problem by describing various methods, then used to provide impressive omnidirectional views.
Morphology: A study of the relation between meaning and form

This is a textbook right in the thick of current interest in morphology. It proposes principles to predict properties previously considered arbitrary and brings together the psychological and the diachronic to explain the recurrent properties of morphological systems in terms of the processes that create them. For the student, the clear discussion of morphology and morphophonemics and the rich variety of data brought in on the way to the theoretical conclusion is material for a direct learning experience.
Efficiency of silicon micromachining by femtosecond laser pulses in ambient air

Femtosecond lasers have proven to be effective tools for precise micromachining. Taking advantage of the reduced heat diffusion and the sharp ablation threshold at comparatively low energy densities, subdiffraction limit sized craters have been machined on silicon wafers by single near infrared Ti:sapphire laser pulses using a high numerical aperture objective lens. Two different ablation regimes have been identified by varying the laser fluence. While two-photon absorption dominates in the low fluence regime, electronic diffusion is a major energy transport mechanism at higher laser fluences. Time-resolved pump-and-probe side-view imaging has been performed to investigate the energy coupling to the target specimen over a wide range of fluences (up to around 1000J∕cm2) at lateral beam dimensions of the order of micrometers. The decrease of the ablation efficiency in the high fluence regime (>10J∕cm2) is attributed to the strong interaction of the laser pulse with the laser-induced plasma.
Accelerating dislocations to transonic and supersonic speeds in anisotropic metals

The dynamics of stress-accelerated dislocations in copper is investigated using molecular dynamics simulations. The structure and motion of dissociated edge dislocations are analyzed using the common neighborhood parameter and local stresses. Dislocations are accelerated by high shear stresses and reach stable velocities in the two transonic regimes. Supersonic dislocations are generated but are transient, as they require high stresses, which trigger nucleation of multiple dislocation dipoles. A velocity plateau in the first transonic regime indicates a radiation-free state in agreement with theoretical predictions.
Steering Weight Concept and its Application to Tropical Cyclones Simulated in a Vertical Shear Experiment

A series of idealized numerical simulations of tropical cyclones is performed to enhance the knowledge on the mechanism of tropical cyclone (TC) motion in vertically sheared environments. The simulations are performed using an f-plane version of the typhoon track prediction model previously run at the Japan Meteorological Agency. A wide variety of TC tracks show up when the model is integrated repeatedly with different formulations of convective parameterization from an identical initial field. To account for the diversity of TC motion in vertically sheared environment, a steering-weight concept is introduced. The steeringweight is a set of weighting factors, mathematically derived from the surface pressure tendency equation, and can be a measure of how sensitive the motion of a TC is, to the steering flow at each vertical level. The experiments with different cumulus parameterizations show that the vertical profile of steering weight tends to strongly depend on the cumulus parameterization scheme used, but much less on the environment specified. This result implies that the axisymmetric thermal structure of modeled TCs, is mostly determined by parameterization schemes rather than environment in the model. And the longterm (say, 72 h mean) TC motion is well explained by the combination of steering weight, and large-scale flow fields. The result suggests that the differences in TC track among numerical prediction models, may be attributable to the differences in steering weight to some degree, given that there is no significant difference in the simulated large-scale flow fields among the models. Moreover, as long as the steering weight concept holds in nature, the steering-weighted deep layer mean flow, instead of the conventional and empirical pressure-weighted one, would work better in accounting for the motion of real tropical cyclones.
Alternative approach to maximum-entropy inference

A consistent approach to the inference of a probability distribution given a limited number of expectation values of relevant variables is discussed. There are two key assumptions: that the experiment can be independently repeated a finite number (not necessarily large) of times and that the theoretical expectation values of the relevant observables are to be estimated from their measured sample averages. Three independent but complementary routes for deriving the form of the distribution from these two assumptions are reviewed. All three lead to a unique distribution which is identical with the one obtained by the maximum-entropy formalism. The present derivation thus provides an alternative approach to the inference problem which does not invoke Shannon's notion of missing information or entropy. The approach is more limited in scope than the one proposed by Jaynes, but has the advantage that it is objective and that the operational origin of the "given" expectation values is specified.
Stabilization of LFT systems

The problem of parametrizing all stabilizing controllers for general linear fractional transformation (LFT) systems is studied. The LFT systems can be variously interpreted as multidimensional systems or uncertain systems, and the controller is allowed to have the same dependence on the frequency/uncertainty structure as the plant. For multidimensional systems, this means that the controller is allowed dynamic feedback, while the uncertain system case can be given a gain scheduling interpretation. Both mu and Q stability are considered, although the latter is emphasized. In both cases, the output feedback problem is reduced by a separation argument to two simpler problems, involving the dual problems of full information and full control. For Q stability, these problems can be characterized completely in terms of linear matrix inequalities. In the standard 1D system case with no uncertainty, the results in the present work reduce to the standard parametrization of D.C. Youla, H.A. Jabr and J.J. Bongiorno (1976), although the development appears to be much simpler, and does not require coprime factorizations. <<ETX>>
Electron content near the lunar surface using dual-frequency VLBI tracking data in a single lunar orbiter mission

In VLBI observations of Vstar, a subsatellite of the Japanese lunar mission SELENE, there were opportunities for lunar grazing occultation when Vstar was very close to the limb of the Moon. This kind of chance made it possible to probe the thin plasma layer above the Moon's surface as a meaningful by-product of VLBI, by using the radio occultation method with coherent radio waves from the S/X bands. The dual-frequency measurements were carried out at Earth-based VLBI stations. In the line-of-sight direction between the satellite and the ground-based tracking station where VLBI measurements were made, the effects of the terrestrial ionosphere, interplanetary plasma and the thin lunar ionosphere mixed together in the combined observables of dual-frequency Doppler shift and phase shift. To separate the variation of the ionospheric total electron content (TEC) near the surface of the Moon from the mixed signal, the influences of the terrestrial ionosphere and interplanetary plasma have been removed by using an extrapolation method based on a short-term trend. The lunar TEC is estimated from the dual-frequency observation for Vstar from UT 22:18 to UT 22:20 on 2008 June 28 at several tracking stations. The TEC results obtained from VLBI sites are identical, however, they are not as remarkable as the result obtained at the Usuda deep space tracking station.
Viscoelastic Properties of Ice

An apparatus has been constructed for the study of deformation under tension of single and polycrystalline ice. Deformations down to 10−5 cm could be measured. Deformation of single and polycrystals was investigated as a function of time, stress, and temperature. Whereas the strain rate for polycrystalline ice decreases with time, that for single glacier ice increases linearly with time. The deformation for fine‐grained polycrystalline ice consists of an instantaneous elastic deformation, a transient creep and a steady state creep. Deformation curves can be represented by empirical equations. The recovery curves on removal of the loads have also been investigated and the plastic flow has been deduced from the residual deformation after complete recovery. This plastic flow was found to be Newtonian within the range of stresses investigated and the viscosity coefficients can be represented by an exponential relationship as follows: η1 = 7.5·e+16100/RT poises, where 16 100 calories is the energy of activatio.
ON THE ASYMPTOTIC EFFICIENCY OF TESTS AND ESTIMATES

Let x1, x2, . be a sequence of independent and identically distributed observations with distributions determined by a real valued parameter θ. For each n=1, 2, . , let Tn = Tn (x1, x2. xn) be a statistic such that the sequence Tn is a consistent estimate of θ. It is shown, under weak regularity conditions on the sample space of a single observation, that the asymptotic effective standard deviation of Tn cannot be less than [nI(θ)]{½}. The asymptotic effective standard deviation of Tn is defined, roughly speaking, as the solution τ of the equation P(|Tn-θ|≥ e|θ)=P(|N|≥ e/τ) when n is large and e is a small positive number, where N denotes a standard normal variable. It is also shown, under stronger regularity conditions, that the asymptotic effective standard deviation of the maximum likelihood estimate of θ is [nI(θ)]-{½}. These conclusions concerning estimates are derived from certain conclusions concerning the relative efficiency of alternative statistical tests based on large samples.
Guided self-assembly of block-copolymer for CMOS technology: a comparative study between grapho-epitaxy and surface chemical modification

Recent progress in Block Copolymer lithography has shown that guided self-assembly is a viable alternative for pushing forward the resolution limits of optical lithography. The main two self assembly methods considered so far have been the surface chemical modification, which is based on the chemical modification of a brush grafted to the silicon, and the grapho-epitaxy, which is based on creating topographic patterns on the surface. We have tested these two approaches for the 22 nm node and beyond CMOS technology, using PS-PMMA block copolymers synthesized by RAFT (Reversible Addition-Fragmentation Chain Transfer) polymerization.
Experimental thick-target bremsstrahlung spectra from electrons in the range 10 to 30 keV

The x-ray spectra produced by the bombardment of thick targets with monoenergetic electrons between 10 and 30 keV have been determined as a function of the incident and emission angles. Spectra have been obtained for Al, Cu, Mo, and W using a Si(Li) detector. The electron current absorbed in the target was measured and corrected for backscattering, allowing a determination of absolute x-ray emission. A modified least-squares procedure was used to represent the spectra as analytical functions while taking into account the efficiency and resolution of the detector. The spectra show the effects of both target absorption and angular distribution of the thin-target bremsstrahlung production. Agreement with the Kramers formula is only moderate.
Lunar surface temperatures at Tranquillity Base

The diurnal temperatures in the lunar soil in the vicinity of Tranquillity Base are calculated from the one dimensional energy equation. The thermophysical properties used in the calcu- lation are the experimentally determined ones which, in general, are temperature dependent. The temperature distributions are calculated over one lunation period for the surface and also several depths below the surface. Comparisons are made with temperatures determined by early investigators using assumed property values and also with values obtained by remote measurement. merit of these lies more in what they inferred about the moon than in temperatures them- selves. The temperature distributions were compared with those obtained from Earth based microwave and infrared measurements. Excellent working models for the lunar sur- face layer were constructed from which thermal and mechani- cal calculations could be carried out. Many previous papers10-13"15 have reported direct, although remote, measurements from which the lunar surface temper- ature distribution was calculated. Photometric scans of the lunar disk during eclipses or lunar nighttimes were made through several infrared and microwave windows in the at- mospheric absorption spectrum. All lunar radiation in the absence of sunlight is emitted radiation and so the tempera- ture can be evaluated using the Planck distribution law. These measurements yield spatially integrated values of the lunar emission over areas on the order of 20-50 km in diameter. This can cause some difficulty in interpretatio n because of the existence of thermal anomalies on the moon caused either by density variations of the surface layer or significant local heat-flow from the lunar interior. The existence of these anomalies is well known and the effect of their presence is apparent on the emission scans made of the lunar surf ace.14"16
In vivo optical detection of brain tumor and tumor margin: a combined autofluorescence and diffuse reflectance spectroscopic study

Recently, optical spectroscopy has shown considerable promise to be used as a potential clinical tool for human brain tumor detection and therapeutic guidance. Our group showed for the first time the possibility of using combined autofluorescence and diffuse reflectance spectroscopy and established its applicability for human brain tumor demarcation in previous in vitro and in vivo studies. We report in this paper the results of a clinical study designed to further evaluate the efficacy of the approach for demarcation of brain tumors and tumor margins from normal brain tissues in intra-operative clinical setting. Using a portable system, optical spectra were collected from the brain of 110 patients undergoing craniotomy at the Vanderbilt University Medical Center. Spectral measurements were taken from multiple sites of tumor core, tumor margin and normal areas of brain tissues and the resulting spectra were correlated with the corresponding histopathologic diagnosis. Using histology as the gold standard, a probabilistic multi-class diagnostic algorithm was developed to simultaneously distinguish tumor core and tumor margin from normal brain tissue sites using independent training and validation sets of data. An unbiased estimate of the accuracy of the model indicates that combined autofluorescence and diffuse reflectance spectroscopy was able to distinguish tumor core and tumor margin from normal brain tissues with an average predictive accuracy of ~88%.