Miracle-dz/UniFAR-FTUs huggingface dataset:
Optical waveguiding using thermal gradients across homogeneous liquids in microfluidic channels

This letter describes the design and operation of a liquid-core liquid-cladding (L2) optical waveguide composed of a thermal gradient across a compositionally homogeneous liquid flowing in a microfluidic channel at low Reynolds number. Two streams of liquid at a higher temperature (the cladding) sandwich a stream of liquid at a lower temperature (the core). This temperature difference results in a contrast in refractive index across the width of the channel that is sufficient to guide light. The use of a single homogeneous liquid in this L2 system simplifies recycling, and facilitates closed-loop operation. Furthermore, with radiative and inline heating of the liquids, it should be possible to reconfigure this optical system with considerable flexibility.
The relation between the urban heat island effect and the underlying surface LUCC of meteorological stations

Based on analysis of the relation between various underlying surfaces intercepted from the different-radius circular buffer zones (the radius is respectively 1, 2, 3km, with 11 Shanghai meteorological stations as their center) and their corresponding air temperatures (four times per day, 2 a.m., 8 a.m., 2 p.m., and 8 p.m. (LST)). It is found that a positive correlation between urban land and UHI, and a strong negative correlation between vegetation and UHI. Urban land and vegetation within the range of 1 km around the station affected the observed air temperature from the station. The cooling effect of vegetation within the range of 2 km could not be ignored, whereas that within 3 km was not obvious. The effect of land use on air temperature was most remarkable at 8 p.m. , followed by 2 a.m. The effect was not obvious at 8 a.m., and weak effect was observed at 2 p.m. At last, it is mainly discussed the possible reasons for how the correlation between different underlying surfaces and UHI can be formed.
Torque scaling in Taylor-Couette flow — an experimental investigation

Within this work we investigate experimentally the turbulent flow between two independently rotating concentric cylinders with radius ratio η = 0.5. The angular velocity of the fluid ω across the gap is measured by Particle Image Velocimetry and Laser Doppler Anemometry for different rotation rates of the inner and outer cylinder. The aim is to analyse the angular momentum transport Jω. In relation to this we measure, in addition to the optical methods, the torque effecting at the inner cylinder. For the case that only the outer cylinder rotates and the inner cylinder is at rest, we show, that for this linear stable flow, the torque is comparatively high and its dependency a non-trivial problem.
Achieving large slip with superhydrophobic surfaces: Scaling laws for generic geometries

We investigate the hydrodynamic friction properties of superhydrophobic surfaces and quantify their superlubricating potential. On such surfaces, the contact of the liquid with the solid roughness is minimal, while most of the interface is a liquid-gas one, resulting in strongly reduced friction. We obtain scaling laws for the effective slip length at the surface in terms of the generic surface characteristics (roughness length scale, depth, solid fraction of the interface, etc.). These predictions are successfully compared to numerical results in various geometries (grooves, posts or holes). This approach provides a versatile framework for the description of slip on these composite surfaces. Slip lengths up to 100μm are predicted for an optimized patterned surface.
Secure and robust steganography using side information at the encoder

Two important classes of data hiding methods are the ones established by watermarking and steganographic applications. Whereas in both cases information is concealed inside a host signal subject to an imperceptibility constraint, some of their fundamental requirements differ. Indeed, the design of watermarking schemes is usually guided by the maximum achievable rate with respect to a given attack power, while the most important constraint for steganographic methods is the undetectability of the hidden communication. In this work we examine the tradeoff between achievable rate and undetectability when watermarking and steganographic constraints are simultaneously imposed to a data hiding scheme. In order to illustrate this tradeoff we focus our attention on two relevant methods which are parallel in their structures, and are, respectively, suitable for the two problems at hand. The first one, distortion-compensated dither modulation, is nearly optimal with respect to the watermarking-like requirements. The second one, stochastic quantisation index modulation, automatically meets the undetectability condition under certain assumptions. Conclusions are drawn as to which scheme is preferable for joint watermarking and steganography constraints, given certain channel characteristics.
Reliable dynamics in Boolean and continuous networks

We investigate the dynamical behavior of a model of robust gene regulatory networks which possess ‘entirely reliable’ trajectories. In a Boolean representation, these trajectories are characterized by being insensitive to the order in which the nodes are updated, i.e. they always go through the same sequence of states. The Boolean model for gene activity is compared with a continuous description in terms of differential equations for the concentrations of mRNA and proteins. We found that entirely reliable Boolean trajectories can be reproduced perfectly in the continuous model when realistic Hill coefficients are used. We investigate to what extent this high correspondence between Boolean and continuous trajectories depends on the extent of reliability of the Boolean trajectories, and we identify simple criteria that enable the faithful reproduction of the Boolean dynamics in the continuous description.
Decoupling of Balanced and Unbalanced Motions and Inertia–Gravity Wave Emission: Small versus Large Rossby Numbers

Abstract This paper provides a brief review of recent results on decoupling of fast [inertia–gravity wave (IGW)] and slow (vortex) motions at small Rossby numbers obtained in the framework of the geostrophic adjustment of localized perturbations. Special attention is paid to the IGW emission and its interpretation in the context of “spontaneous imbalance. ” Several mechanisms that lead to spontaneous IGW emission and, thus, to violations of fast–slow splitting at large Rossby numbers are reviewed: Lighthill radiation, symmetric/inertial instability, and ageostrophic shear (Rossby–Kelvin) instability. New results on the saturation of symmetric instability and on the existence of Rossby–Kelvin instability in continuously stratified fluid are presented.
Photoionization of the outer shells of neon, argon, krypton, and xenon using the relativistic random-phase approximation

Multichannel photoionization calculations using the relativistic random-phase approximation for the outer shells in the rare gases, neon, argon, krypton, and xenon, are presented. Total cross sections and partial cross sections for ns subshells are determined and compared with experiment and with alternative calculations at low energies. Branching ratios of /sup 2/P/sub 3/2/:/sup 2/P/sub 1/2/ cross sections which are sensitive to relativistic and correlation effects are presented and compared with experiment. Angular distribution asymmetry parameters . beta. determined for each subshell are found and compared with experiment; the differences between . beta. values for /sup 2/P/sub 1/2/ and /sup 2/P/sub 3/2/ subshells in krypton and xenon emphasize the importance of relativistic effects in outer subshells of heavy elements. Values of . beta. are given for outermost s electrons which show large relativistic effects near the ''Cooper minima'' of the corresponding partial cross sections. Eigenphases from the multichannel analysis are presented for argon to illustrate mathematical features of the present calculation.
Magnetosheath's parameters and their dependence on intensity and direction of the solar wind magnetic field

The variations of the plasma parameters and of the magnetic field in the vicinity of the stream line passing the subsolar point at the magnetopause are calculated by using a special flow pattern of the plasma which is the result of the formation of a stagnation line at the nose part of the magnetopause. The calculations indicate a rotation of the direction of the magnetic field across the magnetosheath. The displacement of the magnetopause due to the penetration of the solar wind magnetic field into the magnetosphere is discussed.
Wesley Salmon's Process Theory of Causality and the Conserved Quantity Theory

This paper examines Wesley Salmon's "process" theory of causality, arguing in particular that there are four areas of inadequacy. These are that the theory is circular, that it is too vague at a crucial point, that statistical forks do not serve their intended purpose, and that Salmon has not adequately demonstrated that the theory avoids Hume's strictures about "hidden powers". A new theory is suggested, based on "conserved quantities", which fulfills Salmon's broad objectives, and which avoids the problems discussed.
Design and Development of a High-Speed Data-Acquisition System for the Korean VLBI Network

A new high-speed Data Acquisition System (DAS) has been developed for the millimeter-wave VLBI array newly constructed in Korea, the Korean VLBI Network (KVN). The KVN DAS is specially designed to support the most distinctive feature of the KVN, that is simultaneous reception of multiple frequency bands (22, 43, 86 and 129-GHz bands in the current KVN system) for realizing multi-frequency phase referencing, which is the key technology for successful millimeter-wave VLBI observations toward active galactic nuclei and astronomical maser sources. Although the basic functions of the KVN DAS succeed technological elements originally developed in the VERA (VLBI Exploration of Radio Astrometry) Project, essentially new designs have been introduced for the simultaneous processing of four data streams in the optical data-transmission system, the digital ﬁlter, and the digital spectrometer. The KVN DAS system consists of four Gigabit Samplers (GBS), Optical Transmission System (OTS), Digital Filter Bank (DFB), Digital Spectrometer (DSM), and the data recorder. The DFB realizes very ﬂexible and phase-stable channelization of up to four data streams. The DSM facilitates quick look of power and cross-power spectra of observed data. The VLBI output data from the DFB are recorded to the Mark5B recorder with a maximum rate of 1-Gbps. We discuss in the present paper the primary speciﬁcations, designs, and experimental results of the KVN DAS system.
Ewald summation of electrostatic multipole interactions up to the quadrupolar level

Ewald summation expressions are derived for the energy, interatomic forces, pressure tensor, electric fields, and electric field gradients in a periodic computer simulation system of molecules with charges, induced dipoles, and quadrupoles. The full expressions including quadrupolar multipole interactions are given; those involving dipoles are included for completeness. The expressions apply not only to molecules with permanent multipoles, but also to systems of polarizable ions where the multipoles are induced by the interionic interactions. The expressions which allow for this generalization consider the ions to be spherically polarizable, but include the consequences of the coupling between dipolar and quadrupolar induction. The phonon dispersion curves of MgO and the structural lattice constants of Al2O3 in its corundum phase are discussed as specific examples. In simulations with a dipole- and quadrupole-polarizable interaction model, a full Ewald summation of quadrupolar interactions is shown to hav.
Sperm whale codas

Short series of 3 to 40 or more clicks are produced by sperm whales, Physeter catodon, in stereotyped repetitive sequences or codas. The temporal click patterns in codas appear to be unique to individual whales over at least a few hours. It is suggested that sperm whale codas serve as a means of individual acoustic identification. An apparent exchange of codas between two animals was analyzed and acoustical locations calculated for the four‐hydrophone array data that changes in underwater meovement coincided with changes in the coda sequences.
Do Japanese speakers perceive nonexistent vowels in non‐native consonant clusters

Vowel epenthesis is a well known phenomenon that non‐native speakers insert epenthetic vowels inside non‐native consonant clusters. Vowel epenthesis is assumed as perceptual "illusory vowels" (Dupoux et al. 1999). We analyzed vowel epenthesis shown by native Japanese speakers during reading and repetition tasks for non‐native consonant clusters, and analyzed their brain responses using magnetoencephalographic methods. Under the reading task, in which subjects read English words and nonsense words, native Japanese speakers (eight females) inserted vowel /o/ after /t/ and /d/ in consonant clusters, and vowel /u/ after other consonants. Under the repetition task, in which subjects repeated utterances of a native English speaker, native Japanese speakers did not produce epenthetic vowels with few exceptions. The length of exceptional epenthetic vowels found under the repetition task was shorter than those under the reading task. The magnetoencephalographic mismatch responses were elicited by epenthetic vowels.
Vowel‐dependent VOT variation: An experimental study

That the VOT of voiceless stops is typically longer before high, close vowels and shorter before low, open ones is well documented. The hypothesis was tested that high vowels engender longer VOT because they offer greater resistance to the air escaping from the mouth (thereby delaying the transglottal pressure differential required for voicing). A correlation was sought between oral pressure decay (OPD) and VOT. Acoustic and aerodynamic data were collected from a male native speaker of American English uttering 12 nonsense words of the type ati, ata in isolation ten times. Pressure data was sampled by inserting a tube into the subject’s pharyngeal cavity via the nose. The VOT was measured from the release of the burst to the onset of the first periodic cycle. The OPD was defined as the time required for oral pressure to decrease from the peak to a fixed low threshold. The OPD and VOT measurements displayed a significant, linear correlation, indicating that VOT and vowel height are indeed mechanically link.
MoCapaci: Posture and gesture detection in loose garments using textile cables as capacitive antennas

We present a wearable system to detect body postures and gestures that does not require sensors to be firmly fixed to the body or integrated into a tight-fitting garment. The sensing system can be used in a loose piece of clothing such as a coat/blazer. It is based on the well-known theremin musical instrument, which we have unobtrusively integrated into a standard men’s blazer using conductive textile antennas and OpenTheremin hardware as a prototype, the ”MoCaBlazer. ” Fourteen participants with diverse body sizes and balanced gender distribution mimicked 20 arm/torso movements with the unbuttoned, single-sized blazer. State-of-the-art deep learning approaches were used to achieve average recognition accuracy results of 97.18% for leave one recording out and 86.25% for user independent recognition.
A Search for Stars of Very Low Metal Abundance. III. UBV Photometry of Metal-weak Candidates

We present photoelectric UBV photometry for some 2600 metal-poor dwarf and giant candidates selected from the HK objective-prism/interference-filter survey of Beers and colleagues. These data provide the basis for our ultraviolet-excess selection of objects having [Fe/H] ≲ -2.0 for a spectroscopic investigation in which we have obtained ~1-2 Å resolution spectra of some 1000 objects. The present material may also prove useful for investigations of the metal-poor dwarfs and giants more metal-rich than [Fe/H] = -2.0, as well as the misclassified subdwarf O and B stars, white dwarfs, blue metal-poor stars, and field horizontal-branch stars which appear in the catalog.
Numerical method for finding the convex hull of an inclusion in conductivity from boundary measurements

We consider the 2D inverse conductivity problem for conductivities of the form γ = 1 + χDh defined in a bounded domain Ω⊂2 with C∞ boundary ∂Ω. Here D⊂Ω and hL∞(D) are such that γ has a jump along ∂D. It was shown by Ikehata (Ikehata M J. Inverse and Ill-Posed Problems at press) that the Dirichlet-Neumann map determines the indicator function Iω(τ,t) that can be used to find the convex hull of D. In this paper we find numerically the indicator function for examples with constant h and recover the convex hull of D.
Downslope propagation of normal modes in a shallow water wedge

Experimental results are presented for the downslope propagation of acoustic normal modes in a shallow water wedge with a penetrable bottom and a slope of up to 9°. A 7‐element line source was used to generate individual low‐order normal modes. To obtain single modes in a wedge it was necessary to align the line source to form an arc of a circle centered on the wedge apex. The resulting normal modes propagate with wave fronts which are also curved into arcs of circles centered on the wedge apex. These ‘‘wedge modes’’ propagate without coupling. The amplitudes, mode functions, and group velocities of the wedge modes are described by simple adiabatic normal mode theory, but the wave front curvature is not.
Magnetic domain wall motion triggered by an electric current

The current-induced propagation of magnetic domain walls is studied in CoFe nanoconstrictions patterned by electron beam lithography. Propagation of the walls was confirmed by magnetic force microscopy imaging. The device geometry allows us to distinguish between various mechanisms of interaction between electric current and domain walls: a mechanism in which spin transfer associated with current traversing a domain wall dominates. As expected for such a mechanism the domain wall propagation occurs in the direction of electron current flow and has a current threshold of the order ∼1011 A/m2.
Asymptotic expansion and asymptotic robustness of the normal-theory estimators in the random regression model

Asymptotic expansions of the distributions of the sample regression coefficients and residual variance in the multiple regression model with random independent variables are derived under normality and non-normality using Edgeworth expansions up to order O(1/n). It is shown that the asymptotic variances and biases of the sample regression coefficients, and the asymptotic bias of the sample residual variance with the assumption of normality have asymptotic robustness against the violation of the assumption when the explanatory variables are independently distributed with the residual. The results of the simulations show, in finite samples, the accuracy of the asymptotic cumulants and higher-order asymptotic variances used in the asymptotic expansions and illustrate the asymptotic robustness described above. The simulations also indicate that the usual normal approximations to the distributions of the sample regression coefficients are fairly good, when non-normality is not excessive and the normal approximation to the distribution of the sample residual variance is not satisfactory.
Detailed Balance Limit of Efficiency of p‐n Junction Solar Cells

In order to find an upper theoretical limit for the efficiency of p‐n junction solar energy converters, a limiting efficiency, called the detailed balance limit of efficiency, has been calculated for an ideal case in which the only recombination mechanism of hole‐electron pairs is radiative as required by the principle of detailed balance. The efficiency is also calculated for the case in which radiative recombination is only a fixed fraction fc of the total recombination, the rest being nonradiative. Efficiencies at the matched loads have been calculated with band gap and fc as parameters, the sun and cell being assumed to be blackbodies with temperatures of 6000°K and 300°K, respectively. The maximum efficiency is found to be 30% for an energy gap of 1.1 ev and fc = 1. Actual junctions do not obey the predicted current‐voltage relationship, and reasons for the difference and its relevance to efficiency are discussed.
Non-linear predictive control by inversion: discontinuities for critical behaviour

The predictive control by inversion (PCI) technique is presented in this paper. This technique permits extending, in a simple way, the predictive control principles to non-linear models without any linearizing transformation. Singularities and non-minimum phase phenomena which can arise from inversion are treated by introducing control discontinuities either directly on the control or some of its derivatives, or indirectly through reference trajectory discontinuities. Performance and robustness properties of the technique are illustrated by several simulation results.
K-band spectroscopy of Be-star X-ray binaries

We present the first 2.0-2.5 μm spectra of four Be/X-ray binaries, at a resolution of λ/Δλ = 310-400. The spectra show strong hydrogen recombination lines, notably Brγ and, in most cases, the higher order Pfund series. The relative recombination strengths imply that Brγ has a large optical depth, whereas the Pfund lines have relative strengths close to case B and so may be optically thin. The He I 2.06-μm line is also in emission. Mg II emission lines are present, as are Na I lines; the latter are normally associated with emission-zone temperatures that are cooler than the conventional Be-star circumstellar disc. We conclude that optical effects are evident in H I line emission
On Some Differential Geometric Characterizations of the Center of a Lie Group

THEOREM A. For a connected Lie subgroup $H$ of $G$ , the following conditions (A-1) and (A-2) are equivalent; (A-1) His contained in the center of G, (A-2) His totally geodesic with respect to any left invariant Riemannian metric on G. THEOREM B. If $G$ is nilpotent or compact, thenfor each $X\in \mathfrak{g}$ thefollowing conditions (B-1) and (B-2) are equivalent; (B-1) $X$ belongs to the center of $\mathfrak{g}$ , (B-2) the inequality Ric(X) $\geq 0$ holdsfor any left invariant Riemannian metric on $G$, where Ric(X) denotes the Ricci curvature in the direction $X$.
On the onset of mass loss in late-type stars

Il est montre que la pression de radiation causee par les photons pieges dans les transitions rovibrationnelles de la molecule H 2 O excede la pression du gaz dans les atmospheres des etoiles froides de type avance avec une faible gravite de surface. Ce mecanisme peut aider a elever la matiere au point de formation de la poussiere, permettant ainsi de resoudre le probleme de l'etablissement du vent stellaire dans ces sources