Miracle-dz/UniFAR-FTUs huggingface dataset:
A Nondegenerate Kinematic Solution of a Seven-Jointed Robot Manipulator

Kinematically simple manipulators with six joints have unavoidable degenerate configurations that correspond to certain positions or orientations of the end-effector within the workspace. In these degenerate configurations, the end-effec tor of the manipulator is not capable of a motion with six independent degrees of freedom. Such a manipulator reduces the flexibility of a manufacturing system because manufac turing processes need to be planned so that positions or ori entations of the end-effector that correspond to degenerate configurations of the manipulator are not required. In this paper a nondegenerate kinematic solution is devel oped for a kinematically simple seven-jointed robot manipu lator. The solution guarantees that the manipulator is capa ble of positioning and orienting its end-effector within the workspace without ever finding itself in a degenerate configu ration. The nondegenerate kinematic solution is in closed form and is developed from well-known methods and results in three-dimensional kinematics. It is believed that this seven-jointed robot manipulator will be most useful in flexible manufacturing systems.
Logo recognition using alpha-rooted phase correlation in the radon transform domain

Alpha-rooted phase correlation (ARPC) is a recently-developed variant of classical phase correlation that includes a Fourier domain image enhancement operation. ARPC combines classical phase correlation with alpha-rooting to provide tunable image enhancement. The alpha-rooting parameters may be adjusted to provide a tradeoff between height and width of the ARPC main lobe. A high narrow main lobe peak provides high matching accuracy for aligned images, but reduced matching performance for misaligned logos. A lower, wider peak trades matching accuracy on aligned logos, for improved matching performance on misaligned imagery. Previously, we developed ARPC and used it in the spatial domain for logo recognition as part of an overall automated document analysis problem. However, spatial domain ARPC performance can be sensitive to logo misalignments, including rotational misalignment. In this paper we use ARPC as a match metric in the radon transform domain for logo recognition. In the radon transform domain, rotational misalignments correspond to translations in the radon transform angle parameter. These translations are captured by ARPC, thereby producing rotation-invariant logo matching. In the paper, we first present an overview of ARPC, and then describe the logo matching algorithm. We present numerical performance results demonstrating matching tolerance to rotational misalignments. We demonstrate robustness of the radon transform domain rotation estimation to noise. We present logo verification and recognition performance results using the proposed approach on a public domain logo database. We compare performance results to performance obtained using spatial domain ARPC, and state-of-the-art SURF features, for logos in salt-and-pepper noise.
Passivity preserving parametric model-order reduction for non-affine parameters

Parametric model-order reduction (pMOR) has become a well-established technology for analysing large-scale systems with multiple parameters. However, the treatment of non-affine parameters is still posing significant challenges, because projection-based order-reduction methods cannot be applied directly. A common remedy is to establish affine parameter-dependencies approximately, but present extraction methods do not take important system properties, such as passivity, into account. This article proposes a new order-reduction approach that preserves passivity, reciprocity and causality and applies to a wide class of linear time-invariant (LTI) systems. We present the theory of the suggested method and demonstrate its practical usefulness by numerical examples taken from computational electromagnetics.
Finite unified theories

All-loop Finite Unified Theories (FUTs) are very interesting N=1 GUTs in which a complete reduction of couplings has been achieved. FUTs realize an old field theoretical dream and have remarkable predictive power. Reduction of dimensionless couplings in N=1 GUTs is achieved by searching for renormalization group invariant (RGI) relations among them holding beyond the unification scale. Finiteness results from the fact that there exists RGI relations among dimensionless couplings that guarantee the vanishing of the β-functions in certain N=1 supersymmetric GUTS even to all orders. Furthermore, developments in the soft supersymmetry breaking sector of N=1 GUTs and FUTs lead to exact RGI relations also in this dimensionful sector of the theories. Of particular interest for the construction of realistic theories is a RGI sum rule for the soft scalar masses holding to all orders.
Non-holonomic systems as singular limits for rapid oscillations

In this paper, we point out a close relationship between two standard classical problems in mechanics which have coexisted in textbooks for many decades: (1) the pendulum whose suspension point executes fast periodic motion along a given curve; and (2) the skate (known also as the Prytz planimeter, or the ‘bicycle’). More generally, we deal with dynamical systems subjected to rapidly oscillating forcing. Examples include: charged particles in rapidly oscillating electromagnetic fields, in particular the Paul trap; particles in an acoustic wave; a bead sliding on a rapidly vibrating hoop. It turns out that the averaged systems of such kind are approximated by a non-holonomic system. The holonomy turns out to have a transparent geometrical or physical interpretation. For the example of a particle in an acoustic wave the holonomy is directly proportional to the speed of the vibration-induced drift.
Influence of strain-induced indium clustering on characteristics of InGaN/GaN multiple quantum wells with high indium composition

We report the effect of strain-induced indium clustering on the emission properties of InGaN/GaN multiple quantum wells grown with high indium composition by metalorganic chemical vapor deposition. Indium clustering confirmed by high-resolution transmission electron microscopy results in the redshift of the emission peak and the increase of the integrated photoluminescence (PL) intensity. We found that strong carrier localization in indium clustering induces the increases of the activation energy of PL integrated intensity, the temperature independence of PL decay profiles, and the intensity fluctuation of the cathodoluminescence images. All these observations suggest structurally and optically that the improved emission properties in the InGaN/GaN multiple quantum well with high indium composition are associated with the localized states in the strain-induced indium cluster.
Influence of Fluid Motion Past a Plane Boundary on Sound Reflection, Absorption, and Transmission

It is shown that the effect of fluid motion past a plane boundary on the reflection and absorption of sound is equivalent to an increase of the normal acoustic impedance of the boundary by a factor (1 + M sinφ), where φ is the angle of incidence of the sound wave, and M is the Mach number of the flow velocity component in the incidence reflection plane of the wave. Similarly, the acoustic energy flux perpendicular to the boundary and the flow is shown to be increased by the same factor. Reflection and transmission coefficients of a thin solid interface between a fluid in motion and one at rest are given. Furthermore, some comments on the problem of transmission in duets are given. For propagation between two plane parallel boundaries with the same acoustic admittance, we find, for sufficiently small values of the admittance, that the sound pressure attenuation constant of the fundamental mode is modified approximately by the factors (1 + M)−2 and (1 − M)−2 for downstream and upstream propagation, where M .
Actively Q-switched all-fiber lasers

Q-switching of fiber lasers using bulk elements has important drawbacks as reduced mechanical stability and high insertion losses. The development of efficient all-fiber modulation techniques is the key to obtain robust, compact and efficient Q-switched all-fiber lasers. Certainly, the development of fiber Bragg gratings (FBG) has been crucial to make progress on fiber lasers. FBGs permit a simple way to assemble all-fiber laser cavities and can be written in the active fiber itself. The Q-factor of this type of cavities is determined by the reflectivity of the FBGs and the losses of the fiber. Here, we focus on the use of magnetostrictive materials and the acousto-optic interaction to develop efficient Q-factor modulators. Most of these modulators include an FBG and take advantage of the specific interaction of the magnetostrictive materials or the acoustic wave with the FBG itself. Fiber optic technologies permit the development of a rather unique type of fiber lasers, i.e., actively Q-switched distributed feedback (DFB) fiber lasers. In this case, both the use of magnetostrictive materials and the acousto-optic interaction permit the generation of dynamic defects in an FBG that has been previously written in a highly Er-doped fiber.
The Initial Mass Function in the Taurus Star-forming Region

By combining a deep optical imaging (I, z′) survey of 8 deg2 in the Taurus star-forming region with data from the Two-Micron All-Sky Survey (2MASS) and follow-up spectroscopy, we have performed a search for low-mass Taurus members that is complete to 0.02 M☉ for reddenings of AV ≲ 4. We report the discovery of nine new members with spectral types of M5.75-M9.5, corresponding to masses of 0.1-0.015 M☉ by recent evolutionary models. The new M9.5 member is the least massive brown dwarf found to date in the Taurus star-forming region. We derive an initial mass function (IMF) for the fields surveyed in this work and in our previous studies, which encompass 54% of the known Taurus membership. We compare the Taurus IMF with a similarly derived one for the Trapezium Cluster and to mass functions for the M35 and Pleiades open clusters. While the IMFs in all of these regions flatten near ~0.8 M☉, the mass function in Taurus is more narrow and sharply peaked at this mass. Our survey indicates that Taurus has ~2 × fewer brown dwarfs at 0.02-0.08 M☉ than the Trapezium. We discuss the implications of these results for theories of the IMF, and suggest that the lower frequency of brown dwarfs in Taurus relative to the Trapezium may result from the low-density star-forming environment, leading to larger minimum Jeans masses.
Winds and Ejecta from Cool Stars

As young stars evolve from the time of their formation onto the main sequence, they lose mass in a variety of ways. At the very earliest stages, mass loss may be in the form of jets associated with accretion from a surrounding disk. These cool jets carve out the surrounding gas and their changes over time may indicate changes in the star-formation process. At later stages, mass loss is predominantly in the form of a hot, magnetically channelled wind that carries mass, but more importantly angular momentum, away from the star. This wind determines the rotational evolution of cool stars and is intimately connected to the process of field generation deep inside the star. Mass loss also occurs in a sporadic way in the form of the ejection of cool clouds of coronal gas. The coronal distribution and evolution of these clouds (or prominences) gives us vital clues about the structure and short-timescale evolution of stellar coronae. In this review I will discuss recent advances in our understanding of the coronae, winds and accretion processes in cool stars and show how these processes may be related at different stages of evolution.To search for other articles by the author(s) go to: http://adsabs.harvard. edu/abstract_service. html
Evaluations of some quadruple Euler sums of even weight

For positive integers $\alpha_{1}, \alpha_{2}, \ldots, \alpha_{r}$ with $\alpha_{r} \geq 2$, the multiple zeta value or $r$-fold Euler sum is defined by \[\zeta(\alpha_{1}, \alpha_{2}, \ldots, \alpha_{r}) = \sum_{1\leq n_{1}<n_{2}<\cdots<n_{r}}n_1^{-\alpha_1}n_2^{-\alpha_2}\cdots n_r^{-\alpha_r}. \] where $|\alpha|=\alpha_1+\alpha_2+\cdots+\alpha_r$ and $r$ are the weight and depth of $\zeta(\alpha_{1}, \alpha_{2}, \ldots, \alpha_{r})$ respectively. By the general theorem given in [11], the multiple zeta value $\zeta(\alpha_{1}, \alpha_{2}, \ldots, \alpha_{r})$ can be expressed as a rational linear combination of products of multiple zeta values of lower depth if its depth and weight are of different parity. In other words, when the sum of its depth and weight is odd. However, there are still some exceptions for quadruple Euler sums. As conjectured in [6], a quadruple Euler sum with even weight exceeding 14 can be expressed as a rational linear combination of products of multiple zeta values of depth 1, 2 and 3 if and only if it is one of the following forms: $\zeta(1,a,b,a)$, $\zeta(b,1,a,a)$, $\zeta(b,b,1,a)$ or $\zeta(a,b,b,a)$ with $a=b$ or $b=1$. In this paper, we shall evaluate these quadruple Euler sums of even weight by the identities among multiple zeta values with variables and relation obtained from the stuffle formula of two multiple zeta values.
Synchrotron sources. II - Pulsars and compact extragalactic objects.

We discuss some limitation on synchrotron models for optical pulsars and compact extragalactic objects. Using the results of the previous paper, we show that several existing models for the pulsar NP 0532 are inconsistent with the measured time variations and polarization of the optical emission. We rise consider whether the low-frequency falloffs in some extragalactic objects (PKS 2134+004 and OQ 208, but this process is could be due to emission from particles with small pitch angles, absorption by a thermal plasma or synchrotron self- absorption. We find that radiation by particles with small pitch angles could explain the radio emission from PKS 2134+004 and OQ 208, but this process is inconsistent with the observations of NGC 1068. The absorption interpretations cannot account for the turnover in the spectrum of PKS flux would be helpful in evaluating these models. (auth)
Physical properties of Al doped Ba hexagonal ferrite thin films

We developed the thin film microwave magnetic material, M-type barium hexagonal ferrite (BaM) doped with Al, for signal processing devices operating above 40 GHz with little to no applied magnetic field. Al was chosen as the dopant material because it significantly increases the already strong anisotropy field of BaM. A series of thin film BaAlxFe12-xO19 samples, x ranging from 0 to 2 in 0.25 steps, were deposited on Pt templates using a metal-organic decomposition growth technique. The resulting films are polycrystalline and highly textured, with the hexagonal c-axis directed out of plane. These films are also self-biasing; easy axis hysteresis loops have a high squareness ratio, s, in the 0.83-0.92 range. As expected, the anisotropy field increases with x, ranging from 1.34 to 2.19 × 106 A/m (16.9-27.5 kOe) for x = 0-2, while the saturation magnetization Ms decreases with x, ranging from 0.334 to 0.175 × 106 A/m (4πMs = 4.2-2.2 kG) for x = 0-2. These values were measured at room temperature, but the tem.
Slow cyclotron instability due to surface modulation of an annular beam

The Cherenkov instability used in slow-wave devices has been well studied in the literature. However, in previous analyses, the beam motion is restricted to the longitudinal direction assuming an infinitely strong magnetic field. For the finite strength magnetic field, the transverse beam perturbation cannot be ignored and leads to the slow cyclotron instability. Recently, a new version of self-consistent field theory considering three-dimensional perturbation has been developed based on a solid beam, in which the effect of the transverse perturbation appears as a surface charge at a fixed boundary. In the case of a thin annular beam, the boundary is modulated and is essentially different from the solid beam case. We propose a self-consistent field theory considering the moving modified boundary surface. The slow cyclotron instability due to the modulation of an infinitesimally thin annular electron beam is presented.
Evaluation of passive millimeter wave system performance in adverse weather conditions

Passive millimeter wave (PMMW) imaging has shown distinct advantages for detection of terrestrial targets under optically obscuring conditions such as cloud, haze, snow, and light rain. The purpose of this paper is to evaluate the performance of a PMMW imager for terrestrial target recognition with respect to range of detection and climatic variables such as cloud, light rain, and snow. We used a dual polarization MMW radiometer in the frequency range of 70-100 GHz for the evaluation. We present experimental results and analyze the effect of weather conditions on the image quality and its polarization contrast. These results will be useful for quantitative prediction of PMMW system performance for long-range terrestrial imaging.
On p-adic Siegel-Eisenstein series of weight k

show that this series is a Siegel–Eisenstein series of degree two, weight k and level p. As a corollary it is a modular form. We also present a simple formula for the Fourier coefficients of a Siegel–Eisenstein series ofdegree two and prime levels. Let E (2) be the Siegel–Eisenstein series of degree two, weight k and level one, E (2) (Z) = X {C,D} det(CZ + D) −k , Z ∈ H2,
Investigation of low-latitude hydrogen emission in terms of a two-component interstellar gas model

High-resolution 21-cm hydrogen line observations at low galactic latitude are analyzed to determine the large-scale distribution of galactic hydrogen. Distribution parameters are found by model fitting, optical depth effects are computed using a two-component gas model suggested by the observations, and calculations are made for a one-component uniform spin-temperature gas model to show the systematic departures between this model and data obtained by incorrect treatment of the optical depth effects. Synthetic 21-cm line profiles are computed from the two-component model, and the large-scale trends of the observed emission profiles are reproduced together with the magnitude of the small-scale emission irregularities. Values are determined for the thickness of the galactic hydrogen disk between half density points, the total observed neutral hydrogen mass of the galaxy, and the central number density of the intercloud hydrogen atoms. It is shown that typical hydrogen clouds must be between 1 and 13 pc in diameter and that optical thinness exists on large-scale despite the presence of optically thin gas.
Dynamical Spin Susceptibilities in the Superconducting Phase of Sr2RuO4

Dynamical spin susceptibilities in the chiral p -wave superconducting state, the most probable pairing state in Sr 2 RuO 4 , are calculated taking proper account of contributions from collective excitations. It is found that a spin wave mode appears in dynamical transverse susceptibility. The spin wave mode is gapped by spin–orbit interaction, but its frequency in the long wavelength limit can remain at the order of gap frequency when the anisotropy caused by spin–orbit interaction is small. The observability of the spin wave mode in a neutron scattering experiment is discussed.
Studying the avalanching behaviour of a powder in a rotating disc

The use of a rotating disc to study the avalanching behaviour of a powder is discussed. It is shown that the strange attractor plotted in discreet time maps summarizes useful information on the rheological behaviour of powders and powder mixtures. In particular it is shown that the avalanching behaviour is related to the particle size distribution of the powder and that one can study the changes in rheological behaviour as another powder is mixed with it. The strange attractor patterns generated are dependent upon the environmental conditions under which the experiments are carried out. For this reason the measurements are referred to as an assessment of the holistic powder rheology. The potential use of the disc to study the holistic rheology of powder systems is outlined.
Surface diffusion coefficients: Substrate dynamics matters

The pre-exponential factors for Cu adatom diffusion on Cu(001), (110), and (111) are examined within the framework of the harmonic transition-state theory and the embedded-atom method in order to precisely assess the role of the substrate dynamics. We find that the substrate cannot be ignored for an accurate determination of the prefactors: its contribution to the Helmholtz vibrational free energy is typically of the same order as that of the adatom and often of opposite sign so that significant cancellation may occur. These results provide a convenient pathway for the proper calculation of prefactors by using, e.g., ab initio methods.
Dipolar interactions in arrays of nickel nanowires studied by ferromagnetic resonance

Using a planar microstrip transmission line, the dipolar interactions in electrodeposited Ni nanowires arrays an characterized as a function of the membrane porosity (4% to 38%) and the wire diameter (56 to 250 nm). The dipolar interactions between the wires can be modeled in a mean-field approach as an effective uniaxial anisotropy field oriented perpendicular to the wire axis and proportional to the membrane porosity. The dipolar interaction field opposes the self-demagnetization field of an isolated single wire which keeps the magnetization parallel to the wire axis. An increase in the porosity therefore induces a switching of the effective anisotropy easy axis from parallel to perpendicular to the win axis above a critical porosity of 35-38% independent of the wire diameter.
CANDIDATES FOR SPECTROSCOPIC BINARIES FOUND IN THE MOUNT WILSON HALO-MAPPING PROGRAM.

Forty-six candidates for spectroscopic binaries have been found from the four-year radial-velocity data base of the Mount Wilson Halo-Mapping Project. HD 16031 was added to the candidate list when two external velocity data bases were compared. Six of the candidates have previous orbital elements in the literature, to which the present data have been added, and new elements calculated. Comparison of the Mount Wilson velocities with the velocity survey of Carney and Latham (1987) shows a velocity dispersion in the total 309 star overlap sample of σ = 6.4 km s-1. When the 101 stars which Carney and Latham flag as suspected velocity variables are extracted from this overlap sample and compared to the Fouts and Sandage (1986) data, a dispersion of σ = 8.0 km s-1 is found in the residuals. This suggests that if, indeed, the majority of the Carney-Latham 101 suspects are binaries, they will probably be found to have very small velocity amplitudes.