Miracle-dz/UniFAR-FTUs huggingface dataset:
Forward/Reverse Velocity and Acceleration Analysis for a Class of Lower-Mobility Parallel Mechanisms

This paper proposes a novel kinematic analysis method for a class of lower-mobility mechanisms whose degree-of-freedom (DoF) equal the number of single-DoF kinematic pairs in each kinematic limb if all multi-DoF kinematic pairs are substituted by the single one. For such an N-DoF (N < 6) mechanism, this method can build a square (N X N) Jacobian matrix and cubic (N X N X N) Hessian matrix. The formulas in this method for different parallel mechanisms have unified forms and consequently the method is convenient for programming. The more complicated the mechanism is (for instance, the mechanism has more kinematic limbs or pairs), the more effective the method is. In the rear part of the paper, mechanisms 5-DoF 3-R(CRR) and 5-DoF 3-(RRR)(RR) are analyzed as examples.
Changes in Potential Intensity of Tropical Cyclones Approaching Japan due to Anthropogenic Warming in Sea Surface and Upper-Air Temperatures

The intensities of the tropical cyclones (TCs) that approach or make landfall in Japan and the possible changes in these intensities due to global warming have been investigated on the basis of the theoretical model of Holland (1997). This theoretical model calculates the maximum potential intensity (MPI) of a TC as a lower limit of central sea level pressure for a given upper-air temperature profile and underlying sea surface temperature (SST). This study uses the climatology of the JRA-25 long-term reanalysis for the present environment, along with global warming anomalies derived from CMIP3 multi model climate experiments, which are added to the reanalysis climatology to form a warmed environment. A characteristic of the tropical atmosphere is that warming anomalies are amplified toward the upper troposphere, so that TC intensification due to a rise in SST is suppressed to some extent by greater warming aloft. This study evaluates the uncertainty ranges for the MPI changes by considering inter model differences in the warming structure.The MPI-SST relationship in the present climate is consistent with the historical minimum surface pressure in the western North Pacific when the eyewall relative humidity (RH), one of the model’s key parameters, is set at 88%. The average change in the MPI due to a 1°C rise in the SST is -6.7 hPa [-0.6 to -12.0 hPa], where a negative change indicates intensification and the estimated range in brackets reflects the uncertainty in the warming structure. The error of these MPI changes is estimated to be about 15%, assuming that the likely range of the RH parameter is 88 ± 2%. The fractional change in the surface pressure drop is 3.6%, 8.4%, and 19%, in response to a 0.5, 1.0, and 2.0C rise, respectively, in SST, which is basically comparable to existing studies based on observations and numerical simulations. While TC intensification due to global warming tends to be greater for intense TCs at low latitudes, the tendencies at relatively high latitudes near the main islands of Japan suggest that TC development occurs in a broader region over a more prolonged season in a warmed environment.
Examining the relationship between soil structure and soil reflectance using soil pore structure characteristics obtained from image analysis

With new environmental perspectives and policies, such as the Water Framework Directive, the need to understand the processes governing the transfer of water from soils to freshwater systems at a catchment and regional scale has never been more important. It is widely understood that soil texture and structure strongly influence water flow in soils. However, less is known how specific size, shape and aggregation of particles and the associated distribution of pores affect the path of light transmission. In this study, we hypothesize that reflectance spectra exhibit a primary response to soil structure. Using a field study site near Nottingham, United Kingdom that comprised of randomized plots with different crop histories, soil reflectance factor measurements were taken between 350 and 2500 nm on undisturbed soil samples from the top horizon using an Analytical Spectral Devices (ASDs) Field Spec® Pro spectrometer (ASD Inc., Boulder, CO, USA). The undisturbed soils were subsequently impregnated to preserve their structure, and the soil structure properties (in terms of macropore characteristics) were measured in horizontally orientated two-dimensional sections through the soil at different depths. The soil reflectance and transformed spectra (first- and second-order derivatives) were correlated with the soil structural properties and empirical relationships were found between the surface macroporosity, pore size and shape attributes and reflectance values and derivatives of reflectance. Surface macroporosity was highly negatively correlated with reflectance in the visible domain at water absorption bands at ∼1400 and ∼1900 nm and throughout the shortwave-infrared region from 1915 nm onwards.
A Large Deviation Principle of Retarded Ornstein-Uhlenbeck Processes Driven by Lévy Noise

In this article, we develop a large deviation principle (LDP) for a class of retarded Ornstein-Uhlenbeck processes driven by Lévy processes. We first present a LDP result for time delay systems driven by cylindrical Wiener processes based on the large deviations of Gaussian processes. By using a contraction technique and passing on a finite-dimensional approximation, an LDP is obtained for stochastic time delay evolution equations driven by additive Lévy noise, whose solutions are generally not Lévy processes any more.
Z-Test

Z-Test Explorable.com187. 5K reads Z-test is a statistical test where normal distribution is applied and is basically used for dealing with problems relating to large samples when n ? 30. n = sample size For example suppose a person wants to test if both tea & coffee are equal y popular in a particular town. The he c n take a sample of size say 500 from the town out of which suppose 280 are tea drinkers. To test the hypothesis, he can use Z-test. Z-Test's for Different Purposes Th re re different types of Z-test [1] each for different urpose. Some of the types are outlined b low: 1. z test for i gle proportion is used to test a hypothesis on a sp cif value of the p pulation proportion.
Strongly Consistent Determination of Cointegrating Rank Via Canonical Correlations

This article is concerned with the statistical analysis of nonstationary, cointegrated time series. The estimation of the cointegrating structure of such time series is considered, and the problem of identifying the cointegrating rank is addressed. A methodology is presented that leads to strongly consistent estimates of this quantity. The identification is based on a canonical correlation analysis of the original variables and presents an alternative approach to those currently in vogue. The procedures are easily implemented and the practical relevance of the results obtained, which are founded on asymptotic theory, is demonstrated by means of a small simulation study.
Coherent detection of binary multi-h CPM

In the paper receiver structures which minimise the bit error probability for coherent detection of multi-h binary continuous phase modulation (CPM) signals for arbitrary number of observation intervals are examined by means of the traditional union bound at high SNR and by using the concept of the average matched filter (AMF) at low SNR. Multi-h schemes are found by upper-bound minimisation as a function of observation intervals and received SNR. Explicit expressions for the performance of the AMF receiver are derived for three important subclasses of binary multi-h CPM. Optimum and suboptimum receiver structures are examined. Several numerical examples are given, and a comparison of our results with the available results on binary CPM is provided.
Scaling of the velocity fluctuations in turbulent channels up to Reτ=2003

A new numerical simulation of a turbulent channel in a large box at Reτ=2003 is described and briefly compared with simulations at lower Reynolds numbers and with experiments. Some of the fluctuation intensities, especially the streamwise velocity, do not scale well in wall units, both near and away from the wall. Spectral analysis traces the near-wall scaling failure to the interaction of the logarithmic layer with the wall. The present statistics can be downloaded from http://torroja.dmt. upm.es/ftp/channels. Further ones will be added to the site as they become available.
X-ray Variability in the Hot Supergiant ζ Orionis

Hot massive stars represent only a small fraction of the stellar population of the galaxy, but their enormous luminosities make them visible over large distances. Therefore, they are ideal standard candles, used to determine distances of near galaxies. Their mass loss due to supersonic winds driven by radiation pressure contributes significantly to the interstellar medium and thus to the chemical evolution of galaxies. All hot stars are soft x-ray sources; in contrast to the sun with its highly variable x-ray flux, long time scale x-ray variability is not common among hot stars. An analysis is presented here of an unusual increase in x-ray flux observed with the roentgen observatory satellite during a period of 2 days for the hot supergiant ζ Orionis, the only episode of x-ray variability that has been found in a hot star. These observations provide the most direct evidence so far for the scenario of shock-heated gas in the winds of hot stars.
An Existence Theorem for the Point Source Blast Wave Equation

We consider the existence of a solution for the point-source blast wave propagation caused by instantaneous explosion. No similarity solutions of the Euler equations satisfy the conservation law on the shock front, so far as the atmospheric pressure ahead of the shock is not negligible. To describe the initial state, it is assumed that the total amount of energy carried by the blast wave is constant. By a hodograph transform this free boundary problem is converted into an eigenvalue problem for a system defined on a bounded rectangle such that this initial state assumption is satisfied. The solution is prescribed in the form of a power series expansion in one of the variables y = C 2/U 2 for front shock speed U and sound velocity C. Its convergence is shown by applying the fixed point theory of contractive mapping defined through linearization of the system. Our solution is local in y and exact there.
Rice Blast Pyricularia oryzae CAV. Isolates in Kenya Characterized Sequenced and Registered

: Rice ( Oryza sativa L.) is the third most important cereal crop in Kenya. Globally, rice remains the most favoured grain for human consumption. In Kenya and most of the African countries production is below the world averages. Rice Blast caused by Pyricularia. oryzae Cav. has been singled out as one of the main causes limiting production. The control of this disease has remained elusive. Variation of the pathogen in the population is suspect. This research was therefore carried out to analyze the genotypes of different isolates previously described morphologically. Eight Different Kenyan isolates identified from a previous survey were studied using DNA analysis and sequencing of the ITS region from the rice genome. Results revealed variation with respect to colony color, diameter, morphology and conidia shape & size. Sequenced Isolates clustered into four haplo groups (HGs), that is HG1 for isolate 4, HG2 for isolate 6, HG3 for isolate 7a and HG4 for isolate 7b.The new isolates’ sequences were submitted to the NCBI GenBank database and the accession numbers assigned as, Pyricularia oryzae KY275366, Pyricularia oryzae KY275367 and Pyricularia oryzae KY275368. The result of the present study demonstrates that there is a certain level of genetic diversity among isolates of P. oryzae from various regions of Kenya. The screening for resistance to P. oryzae therefore should take into account the different isolates in order to avoid cryptic error.
Impact of Total Quality Management Practices (TQMPs) on Construction Project Quality Performance in Developing Countries: Study of Construction Businesses in Ghana

Globally, maintenance of quality is an important consideration in modern construction. This is evident by clients’ increasing use of companies’ reputations for good quality work as a basis for choosing prospective contractors. The aim of this research is to empirically examine the extent to which TQM practices are associated with Construction project quality performance (CPQP). Based on TQM framework developed from comprehensive literature review of TQM, a survey instrument was developed and used to collect data to test the impact of TQM practices on CPQP. The results of the study suggest that TQM elements are positively associated with CPQP and that, soft aspect of TQM elements has higher impact on CPQP than hard aspect of TQM elements.
Viral diseases of Poaceae family plants

Plants of common cocksfoot ( Dactylis glomerata L.), tufted hairgrass ( Deschampsia cespitosa (L.) P. Beauv. ), meadow fescue ( Festuca pratensis Huds.), perennial ryegrass ( Lolium perenne L.), Festulolium loliaceum (Huds.) P. Fourn. ( Festuca pratensis L . × Lolium perenne L . ) showing symptoms of mosaic spotting, chlorotic and necrotic streaks on leaves and stems were detected at the Plant Breeding Centre of Lithuanian Institute of Agriculture and also at the Vilnius station for investigation of plant cultivars. Virus isolates were investigated by the methods of test-plants, electron microscopy and DAS-ELISA. According to the results of symptomatology on host- and test-plants, virion morphology, transmission of viral infection by mechanical inoculation and aphides, and DAS-ELISA, for the first time in Lithuania the following viruses were identified: Cocksfoot streak potyvirus , Festuca necrosis closterovirus and Ryegrass mosaic rymovirus.
A wavelet-based time-varying autoregressive model for non-stationary and irregular time series

In this work we propose an autoregressive model with parameters varying in time applied to irregularly spaced non-stationary time series. We expand all the functional parameters in a wavelet basis and estimate the coefficients by least squares after truncation at a suitable resolution level. We also present some simulations in order to evaluate both the estimation method and the model behavior on finite samples. Applications to silicates and nitrites irregularly observed data are provided as well.
Dynamics Modeling of the Planar Double Inverted Pendulum

planar double inverted pendulum is a strong coupling, uncertain and complex nonlinear system, and the dynamics model of which is the basis of control, simulation and analysis. In the paper coordinate systems of the planar double inverted pendulum were first defined, and then the dynamics model of which was built up based on screw theory and the Lagrange principle. The modeling method used being systematic and standardized, it is easy to extend to dynamics modeling of higher order planar inverted pendulums or other multi-body systems.
Phononic band gap engineering in graphene

Using ab initio and molecular dynamics simulations with semi-empirical potentials, the phonon density of states (PnDOS) of graphene with different types of defects such as substitution atoms (Si), carbon isotopes (12C and 14C), and vacancies was calculated. The main interest was to investigate the possibility to generate phononic band gaps (PBGs) in the PnDOS of graphene, since the derived structures may have sufficiently low thermal conductivity and find applications in improved thermoelectric materials. From all the studied defect types, the silicon substitution is the only one that creates PBGs.
A robust SPH formulation for solids

The smoothed particle hydrodynamics method such as other meshless methods is a very efficient numerical method for some types of modelling such as fracturing of solids. This technique, initially developed for fluid or gas, was extended to solids but it suffers from severe instability problems. The origins of these instabilities have been identified by the SPH community and solutions were developed to remove them. An overview of the different proposed techniques is presented. Among them it appears that for solids the use of the total Lagrangian formulation is the most simple and valuable solution. In the same time stress points can be added to this new formulation in order to improve accuracy and convergence rate despite an increase in computational cost.
Identification and Analysis of Student Conceptions Used to Solve Chemical Equilibrium Problems

This study identified and quantified chemistry conceptions students use when solving chemical equilibrium problems requiring application of Le Chatelier's principle, and explored the feasibility of designing a paper and pencil test to accomplish these purposes. A 10-item pencil and paper, two-tier diagnostic instrument, the Test to Identify Student Conceptualizations (TISC), was developed and administered to 95 second-semester university general chemistry students after they received regular course instruction concerning equilibrium in homogeneous aqueous, heterogeneous aqueous, and homogeneous gaseous systems. To validate TISC, nine students from a stratified random sample were selected for interviews incorporating comparable chemistry problems. The probability that TISC correctly identified an answer given by a student in the interview was p = . 64, whereas the probability that TISC correctly identified a reason given by a student in the interview was p = . 49. Eleven prevalent incorrect student conceptions about chemical equilibrium were identified by TISC. Students consistently selected correct answers more frequently (53% of the time) than they provided correct reasons (33% of the time). The level of association between student answers and their respective reasons on each TISC item was quantified using conditional probabilities calculated from logistic regression coefficients. The Kuder-Richardson 20 reliability for TISC was . 79. © 2000 John Wiley & Sons, Inc. J Res Sci Teach 37: 160–176, 2000
Collagen Tubular Airway-on-Chip for Extended Epithelial Culture and Investigation of Ventilation Dynamics

The lower respiratory tract is a hierarchical network of compliant tubular structures that are made from extracellular matrix proteins with a wall lined by an epithelium. While microfluidic airway-on-a-chip models incorporate the effects of shear and stretch on the epithelium, week-long air-liquid-interface (ALI) culture remains limited to static conditions. The circular cross-section and substrate compliance associated with intact airways have yet to be recapitulated to allow studies of epithelial injuries under physiological and ventilation conditions. To overcome these limitations, we present a collagen tube-based airway model. Sustaining a functional human bronchial epithelium during two-week perfusion is accomplished by continuously supplying warm, humid air at the apical side and culture medium at the basal side. The model faithfully recapitulates human airways in size, composition, and mechanical microenvironment, allowing for the first time dynamic studies of elastocapillary phenomena associated with regular breathing as well as mechanical ventilation, along with the impact on epithelial cells. Findings reveal the epithelium to become increasingly damaged when subjected to repetitive collapse and reopening as opposed to overdistension and suggest expiratory flow resistance to reduce atelectasis. We expect the model to find broad potential applications in organ-on-a-chip applications for various tubular tissues.
Dichromatic light halting using double spin coherence gratings

Light control by another light has drawn much attention in nonlinear quantum optics. Achieving all-optical control of the refractive index has been a key issue in all-optical information processing. Ultraslow light has been a good candidate for this purpose, where a giant phase shift can be achieved. The recent presentation of stationary light utilizing ultraslow light is an advanced example of such research. The stationary light functions as cavity quantum electrodynamics, where no high-Q-factor mirror pair is needed. In this paper, we report on two-color halted light pulses inside a solid medium, where the trapping time is comparable with that of ultraslow light but is much longer than quantum mapping storage time. The observed two-color halted light is achieved by means of double Raman optical field-excited spin coherence gratings, where slow light enhanced backward nondegenerate four-wave mixing processes play a major role.
Vibration reduction using biologically inspired topology optimization method: optimal stiffeners distribution on an acoustically excited plate

This paper presents the development of a biologically inspired method for topology optimization and its application to a vibration suppression problem. The proposed method is based on modeling the structure topology (distribution of stiffening ribs) by replicating the natural growth of dendritic structures, which are ramified branches as those e.g. in leaves or in insect wings. The test case is a plate excited by acoustic pressure. The multi-objectives topology optimization aims to reduce both the vibration amplitude and mass of the plate. Experimental tests are performed for baseline plate model validation and identification of acoustic excitation distribution. A set of solutions are designed by the proposed method and numerically compared with traditional optimization approaches, showing improved performances. Finally, in order to evaluate industrial applicability, the robustness of the solutions to uncertainty in branch widths is demonstrated.
EXPERIMENTAL STUDY OF TURBULENT BUBBLY SHEAR FLOWS

Abstract This paper in memory of Pr Dukler summarizes a set of experiments on bubbly shear flows carried out by two groups, in Toulouse and in Lyon. Homogeneous shear flows, plane mixing layer, boundary layer on a flat plate and sudden area expansion have been investigated, for low and moderate void fraction. Measurements of mean liquid velocity show that the main features of the corresponding single phase flow are conserved, in particular self-similarity of the mean velocity profiles. However, the turbulent field is strongly modified. The transverse interfacial momentum transfer has been evaluated, and proves to be dominated by instantaneous local forces, which are not usually taken into account in eulerian models.
Upconversion Luminescence of Er3+ Ions in Transparent Germanate Glass Ceramics Containing CaF2 Nanocrystals

The visible upconversion and near-infrared luminescence of Er3+ ions in germanate glass ceramics containing CaF2 nanocrystals are investigated. The nanocrystals are characterized by x-ray diffraction (XRD) and transmission electron microscopy, showing their mean sizes less than 20 nm. High transmittance of the glass ceramics is displayed by absorption spectra. The upconversion luminescence intensity in the glass ceramics increases significantly with increasing temperature. Both the shifts of the XRD peaks and the Stark-split shown in the luminescence spectra indicate the entrance of the Er3+ ions into the CaF2 nanocrystals, which is confirmed by a Judd–Ofelt analysis. Possible mechanisms of the upconversion luminescence are analyzed.