Miracle-dz/UniFAR-FTUs huggingface dataset:
Three-dimensional traveltime equation for dipping layers

The traveltime equation for homogeneous layers with two‐dimensionally dipping interfaces is well known, but it has been proven only for a limited variety of profile geometries. Existing proofs do not necessarily lend themselves to use with other types of profiles, or to extension into three dimensions. When the distance that a ray travels and the elapsed time are decomposed into orthogonal components, and each interaction of the ray and the interface is examined separately, the time contributions for ray travel in the two orthogonal directions can be isolated for ray segments between horizontal planes of reference. The terms in which these contributions are expressed are independent of any part of the structure beyond the ray segment under consideration. Therefore, the total traveltime for a ray can be obtained by simple summation of such contributions. This process represents a new proof of the traveltime equation, but, more importantly, it provides a method for constructing the correct equation for virt.
On an Approximate Godunov Scheme

We are interested in the numerical resolution of hyperbolic systems of conservation laws which do not allow any analytical calculation and for which it is difficult to use classical schemes such as Roe's scheme. We introduce a new finite volume scheme called VFRoe. As the Roe scheme, it is based on the local resolution of a linearized Riemann problem. The numerical flux is defined following the Godunov scheme, as the physical flux evaluated at the interface value of the linearized solver. The VFRoe scheme is conservative and consistent without fulfilling any Roe's type condition. Some numerical tests on shock tube problems and two-phase flows problems are presented.
Microstructural evolution and mechanical properties of SnAgCu alloys

Lead containing solder paste is now considered as an environmental threat. In order to eliminate this undesirable environmental impact associated to their production, a family of lead-free solder joint, Sn-3.8Ag-0.7Cu, is proposed. Microstructural and mechanical data of this solder joint have been acquired and compared with the most common used SnPb solder paste. The evolution of the microstructure as well as the failure mode and the mechanical properties of SnAgCu solder joint are discussed as a function of strain rate, annealing treatments, and testing temperature. Tensile tests have been performed, at temperatures ranging from −50to+150°C, on bulk samples. Changes of the mechanical properties of bulk tested samples are actually correlated with microstructural changes, as shown by transmission electronic microscopy investigations.
Low Power-Consumption and High Response Frequency Thermo-Optic Variable Optical Attenuators Based on Silicon-on-Insulator Materials

A novel silicon-on-insulator thermo-optic variable optical attenuator with isolated grooves based on a multimode interference coupler principle is fabricated by the inductive coupled plasma etching technology. The maximum fibre-to-fibre insertion loss is lower than 2.2 dB, the dynamic attenuation range is from 0 to 30 dB in the wavelength range 1500-1600 nm, and the maximum power consumption is only 140 mW. The response frequency of the fabricated variable optical attenuator is about 30 kHz. Compared to the variable optical attenuator without isolated grooves, the maximum power consumption decreases more than 220 mW, and the response frequency rises are more than 20 kHz.
On the orbital period change of the binary pulsar PSR 1913+16

The theoretical significance of the raw observational parameter called the rate of orbital period change, P b obs , of the binary pulsar PSR 1913+16 is reexamined. It is shown that the current precision (∼ 0.8 %) on the determination of P b obs makes it necessary to take explicitly into account the effects of the galactic accelerations of the pulsar and the Sun, and that of the proper motion of the pulsar. Several other possible contributions to P b obs are (re)examined and found negligible. As the value of the galactic contribution to P b /P b depends explicitly on the distance to the pulsar, say d, the determination of d from dispersion measurements is reexamined.
A DECOUPLED MULTIPLE MODEL APPROACH FOR STATE ESTIMATION OF NONLINEAR SYSTEMS SUBJECT TO DELAYED MEASUREMENTS

The state estimation of nonlinear systems with delayed measurements is investigated in this paper. The proposed approach is based on the representation of the nonlinear system by a decoupled multiple model that, to our knowledge, has not been investigated extensively. This multiple model approach offers an interesting alternative to the classically used multiple model known as Takagi-Sugeno multiple model. Indeed, in contrast to this last, the decoupled multiple model makes it possible to introduce a state vector with a different dimension for each submodel. Sufficient conditions for ensuring the exponential convergence of the estimation error are provided in terms of LMIs.
Electro-pneumatic Control of Soft Robotic Hand Prosthesis Actuators

This project arises in response to some limitations of the current conventional prostheses, namely aesthetic, mechanical and cost, that fail to fulfil the needs of its users, for example with soft objects. The results obtained until now proved to be satisfactory in the approximation of the hand morphology, low cost and the designed mechanical properties. However, this paper aims to present a developed electro-pneumatic control board to control the soft robotic prosthesis of the human hand. The first tests done with this control board show that it will be necessary to improve the physical design and the 3D printing of the soft actuators (fingers) due to some leaks in the printed actuators.
An Algorithm for Force-Closure Grasping of Three-Fingered Hand

On the assumption of FCWF model, the conditions of three-fingered robot hand force-closure grasping are equivalent to grasp matrix be full rank and exist rigorous internal forces. Based on the analysis to the geometrical characteristics of contact points, the existence condition of the frictional sectors is established. By means of studying the relative location relationships between the frictional sector borderlines and their intersections, the existence condition of the concurrent polygon of three internal forces is presented. Taking the equilibrium relation of internal forces into consideration, a general algorithm using vector calculation for force-closure grasping is established. An example is given to illustrate the validity of the algorithm.
Production of argon isotopes by spallation of Sc, Ti, Fe, Co, Ni, and Cu

Spallation ratios and production cross sections of /sup 36,38,39,42/Ar have been measured for the interaction of 0.080, 0.150, 0.600, 1.05, and 24 GeV protons with scandium, titanium, iron, cobalt, nickel, and copper. Argon is measured by means of a 60/sup 0/ 12 cm radius mass spectrometer, equipped with a gas extraction line and a calibration system. Precision is 1 to 5% for isotope ratios, and 10 to 20% for the cross sections. With regard to spallation reactions, some systematic effects are shown or confirmed. Excitation functions go through a maximum at high energy, then drop asymptotically to a constant value. The ratio of maximum to asymptote cross sections is about 1.6. The spallation ratios depend linearly on the (N/Z)/sub T/ ratios of the target and there is probably a linear correlation between the position of the peak of the spallation distribution and the (N/Z)/sub T/ ratio. Experimental values are compared with semiempirical fits and some astrophysical implications are discussed.
Energy cascades as branching processes with emphasis on Neveu's approach to Derrida's random energy model

Continuous-space-time branching processes (CSBP) are investigated in order to model random energy cascades. CSBPs are based on spectrally positive Lévy processes and, as such, are characterized by their corresponding Laplace exponents. Special emphasis is put on the CSBPs of Feller, Lamperti and Neveu and on their Poisson point process representations. The Neveu model (either supercritical or subcritical) is of particular interest in physics for its connection with the random energy model of Derrida, as revisited by Ruelle. Exploiting some connections between the partition functions of energy and the Poisson-Dirichlet distributions of Pitman and Yor, some information on the zero-temperature limit is extracted. Finally, for the subcritical versions of the three models, we compute the distribution of some of their interesting features: extinction time and probability, area under the profile (total energy) and width (maximal energy).
Extraction of Speech Pitch and Formant Frequencies using Discrete Wavelet Transform

Extraction of pitch and formant frequencies is an important issue in speech processing. Pitch frequency is the fundamental frequency of the speech signal, and formant frequencies are essentially resonance frequencies of the vocal tract. These frequencies vary among different persons and words, but they are within certain frequency range. Practically, the first three formants are enough for coding and other processes. The most common methods for estimating formants are cepstrum and linear predictive coding. In this study, a wavelet based method using filter bank concepts is presented to estimate these frequencies.
Fault Diagnostics with Legacy Power Line Modems

We evaluate the use of legacy power line modems (PLMs) for fault diagnostics, and in particular, focus on short-circuit faults in underground power cables. Prior works have shown that broadband power line communication channel estimates that are computed within the PLMs can be used to gain insight into the health of underground cables. However, several legacy PLM chip-set implementations do not provide access to the estimated channel frequency response in its entirety. Therefore, to facilitate and accelerate a practical roll-out of a PLM-based diagnostics solution, we investigate if readily extractable parameters, such as the estimated signal-to-noise ratio values and/or the computed precoding matrices in case of multiple-input multiple-output (MIMO) transmission, provide sufficient indication into the cable health status. By extracting suitable features from this raw data, we show through simulations that our machine learning based automated cable diagnostics solution achieves satisfactory results in predicting faults, and near-perfect performance in fault identification.
EMG Based Control of Individual Fingers of Robotic Hand

Research on robotic hand for prosthesis is widely being carried out. This paper attempts to provide an enhanced control of individual fingers of robotic hand using electromyography (EMG). Eight-channel surface EMG is to acquire signals from widest part of forearm of 10 subjects. These signals are corresponding to movement of five individual fingers, which are thumb, index finger, middle finger, ring finger, and little finger. Features are extracted from these signals and Deep Neural Network is applied as classifier to distinguish between the five signals with an average accuracy of around 95%. The classified signal is then interfaced with the robotic hand to perform mimicking of individual finger motion. This work can be effectively used for hand rehabilitation with flexibility of actively controlling individual finger motion.
Chemical vapor deposition of poly (p-phenylene vinylene) based light emitting diodes with low turn-on voltages

We report fabrication of single layer poly (p-phenylene vinylene) (PPV) light emitting diodes with low turn-on voltages by chemical vapor deposition of dihalo p-xylenes. Devices made from dibromo p-xylene exhibit turn-on fields of 2×106 V/cm, which is in good agreement with solution processed PPV devices. Devices made from dichloro p-xylene, however, have significantly lower turn-on fields of 6.5×105 V/cm. The electroluminescent output of bilayer PPV/tris (8-hydroxyquinoline) aluminum devices made from the two monomers suggests that the chlorine based polymer may have improved electron transport characteristics compared to solution processed polymer, which is tentatively attributed to residual chlorine from the thermal conversion process.
A procedure for the one-parametric linear complementarity problem

We propose a principal pivoting method for solving the one-parametric linear complementarity problem where all the coefficients are linear functions of the parameter K and the matrix of the problem is sufficient for all values of the parameter in the interval under consideration. We increase k from to A subprogram using the least-index rule is developed for passing by the critical points at which the basis must be changed. The solution vector is a piecewise rational function of the parameter. It turns out that, under a restrictive assumption, the procedure is finite (if the problem becomes infeasible when increasing the parameter, the procedure must be terminated). We give some special cases in which the restrictive assumption holds. As a by-product, we obtain a new proof for the criss-cross method for the linear complementarity problem with a sufficient matrix. We also consider some applications of the procedure: parametric methods for the linear complementarity problem with a sufficient matrix, applicat.
Study of Delayed-Detached Eddy Simulation with Weakly Nonlinear Turbulence Model

This paper presents a parallel computation with hybrid Reynolds-averaged Navier-Stokes and large eddy simulation methods. Two types of hybrid approaches, referred to as detached eddy simulation and delayed-detached eddy simulation, are investigated through introducing length scales into the weakly nonlinear k-w turbulence model. Before the implementation of hybrid methods, the baseline weakly nonlinear model and k-w shear-stress-transport model are validated in the transonic RAE-2822 airfoil and ONERA-M6 wing cases. The numerical results show satisfactory agreement with the available experimental data. The Reynolds-averaged and hybrid methods based on the weakly nonlinear turbulence model are then applied to calculate the high Reynolds number transonic separation flows around NASA TN D-712 wing fulesage For the higher angle of attack case (a = 26.2 deg), both hybrid methods deliver good results when compared with the experiment; for the moderate angle of attack case (a = 12.5 deg), the results obtained with the delayed detached eddy simulation are satisfactory, whereas the starting point of the wing vortex breakdown predicted with the detached eddy simulation is too far upstream.
Time delay between the nucleosynthesis of cosmic rays and their acceleration to relativistic energies

If cosmic rays originate in a supernova explosion, they might be accelerated immediately after their synthesis. This would prevent electron-capture decay of unstable isotopes, and could result in large differences between cosmic-ray and solar-system abundances. Existing data on the abundances of iron, cobalt, and nickel in cosmic rays show great similarity to the solar system abundances, therefore, it is concluded that more than a year elapses between the synthesis of the cosmic-ray nuclei and their acceleration to relativistic energies. 2 figures.
Persistence Length of Polyelectrolyte Chains

The classical theory of the electrostatic persistence length of polyelectrolyte chains due to Odijk, Skolnick and Fixman (OSF) is revisited. In contrast to the original theory, our approach takes into account the effect of fluctuations in the chain configuration. As a result, we find that the OSF theory, although correct for intrinsically rigid polyelectrolytes, breaks down for flexible chains. A quantitative criterion is established to distinguish between flexible and rigid chains. For flexible chains, we use a variational theory to compute the electrostatic persistence length, which is found to be proportional to the Debye-Huckel screening length, in agreement with many experimental and simulation results.
Evaluation of effective eddy diffusive coefficients using radar observations of turbulence in the stratosphere

Radar observations show that thin, persistent layers of turbulence occur sporadically in the troposphere and stratosphere. Two probabilistic approaches are used to show that the vertical eddy diffusivity due to such layers is of the order of 0.2-0.3 sq m/sec in the lower stratosphere. An actual realization of turbulent layers, derived from the radar observations at Arecibo, is used in a numerical approach to obtain a profile of eddy diffusivity. It is suggested that turbulence plays a significant role in the vertical transport of trace constituents in the stratosphere.
On the Low Wave Number Behavior of Two-Dimensional Scattering Problems for an Open Arc

The low wave number asymptotics for the solution of the Dirichlet problem for the two-dimensional Helmholtz equation in the exterior of an open arc is analyzed via a singlelayer integral equation approach. It is shown that the solutions to the Dirichlet problem for the Helmholtz equation converge to a solution of the Dirichlet problem for the Laplace equation as the wave number tends to zero provided the boundary values converge.
Camera calibration method based on circular ring

A novel camera calibration method based on circular ring is proposed in this paper. It has been proven that the first two columns of calculated point transfer homography mapping from the circular ring plane to the image plane have one isometric ambiguity. But in that case the restriction of homography on the IAC (the image of absolute conic) is still tenable, so the restriction could be applied to the calibration of the internal camera parameters. The ambiguity of the first two columns of homography directly results in the isometric ambiguity of the rotation matrix which can be explained in geometry as the isotropy of circular ring. But the third column of homography has no ambiguity, so the unique of which could not lead to the ambiguity of the translation vector. The external camera parameters can be calibrated using circular ring while there is a discrepancy of isometric transformation of rotation matrix within the model plane, which is most distinguished from the principle of the other plane-based calibration method such as points, lines and multiple conics. The proposed method has two distinctly superiority over the calibration based on coplanar points or lines: Better noise immunity because of the global property of the circular ring feature, and automatic calibration because the image matching of the circular ring feature is much easier compared with the one of points or lines. Both simulation and real data are used to prove the correctness, high accuracy and robustness of our calibration method.
BV photographic and CCD photometry of IC 4651

A BV photometric survey in IC 4651 based on photographic and CCD material calibrated with photoelectric photometry from Eggen (1971) and Anthony-Twarog and Twarog (1987) has been completed. The color-magnitude diagram is consistent with an age of 2.4 + or - 0.3 x 10 to the 9th yr derived by comparison with the isochrones of VandenBerg (1985) if the apparent distance modulus and reddening derived from uvby photometry in Anthony-Twarog and Twarog (1987) are employed. While evidence is found of a hook in the upper main sequence, no evidence is found of a significantly bifurcated main sequence for this cluster, although it is similar in age to NGC 752 and NGC 3680, where this phenomenon has been noted. Finally, the survey has not resolved the apparent deficit of main-sequence stars fainter than V = 14.5 noted in Anthony-Twarog and Twarog (1987). 16 references.
A dimension-reduced approach to space-time Kalman filtering

SUMMARY Many physical/biological processes involve variability over both space and time. As a result of difficulties caused by large datasets and the modelling of space, time and spatiotemporal interactions, traditional space-time methods are limited. In this paper, we present an approach to space-time prediction that achieves dimension reduction and uses a statistical model that is temporally dynamic and spatially descriptive. That is, it exploits the unidirectional flow of time, in an autoregressive framework, and is spatially 'descriptive' in that the autoregressive process is spatially coloured. With the inclusion of a measurement equation, this formulation naturally leads to the development of a spatio-temporal Kalman filter that achieves dimension reduction in the analysis of large spatio-temporal datasets. Unlike other recent space-time Kalman filters, our model also allows a nondynamic spatial component. The method is applied to a dataset of near-surface winds over the topical Pacific ocean. Spatial predictions with this dataset are improved by considering the additional non-dynamic spatial process. The improvement becomes more pronounced as the signal-to-noise ratio decreases.
Analysis of Broadband PLC Characteristics as a Second Use Case for Distribution System Operators

The current technical condition of power cables and the grid states in German distribution networks are usually unknown to a distribution system operator because the necessary sensors, diagnostic measurements and communication technologies are rare to find in the medium and low voltage networks. To meet the growing demand for communications in the context of their development to smart grids, the broadband powerline technology (BPL) provides a convenient and cost-effective way to realize communication there, since it uses the existing infrastructure as its transmission medium. In a research project a second use case of BPL technology was investigated to achieve another benefit for distribution network operators beside the solution of communication tasks. In this paper an approach to analyze the data transmission characteristics of a BPL communication to gather new information about cable conditions and grid states is presented. Therefore, the results of laboratory and field testing are presented in combination with the theoretical background, which confirm that the aforementioned second use case of BPL is extant and usable.
X‐ray scattering from interfacial roughness in multilayer structures

A quantitative theory of the nonspecular scattering of x rays from multilayer structures having rough interfaces is presented. The results are valid for arbitrary polarization and angles of incidence (measured from the normal) less than the critical angle for total external reflection. A structural model is adopted wherein each interface is assumed to be described by a surface having statistically random roughness with a well‐behaved power spectrum. In addition, the model accounts for arbitrary correlation of the roughness between different interfaces. Calculations are presented for a variety of roughness configurations to investigate the dependence of the nonspecular scattering on the fundamental structural parameters. In particular, it is shown that the scattering from correlated roughness exhibits characteristic resonance behavior (quasi‐Bragg diffraction).
Deep Identity Confusion for Automatic Sleep Staging Based on Single-Channel EEG

Sleep Staging (SS) is a vital step in sleep neurobiology. Though many previous approaches have been proposed to solve it, most of them suffer from poor generalization for unknown identity. In this paper, we proposed a deep identity confusion method to extract powerful task-specific and identity-invariant feature and then score sleep stages with non-linear machine learning model. With an unified CNN-LSTM structure employed for feature extraction, we implement identity confusion with an extra identity prediction branch and apply inversed gradients to frontal layers during back-propagation. Then the deep feature is used to train a XGBoost classifier. Experiments on Sleep-EDF benchmarks achieve classification accuracy and macro F1 score of 84.1% and 78.9%, and it suggests proposed method boost performance of origin deep learning base model and show competitive result comparing to state-of-the-art methods.