Miracle-dz/UniFAR-FTUs huggingface dataset:
Fabrication of shape memory nanofibers by electrospinning method

Shape memory nanofibers are capable of fixing a temporary shape and recovering a permanent shape in response to stimulus. Nafion nanofibers with shape memory effect are achieved via electrospinning technology. The resulting nanofibres exhibit the smooth, continuous, uniform fibrous structure. The diameter of nanofibers increases after annealing progress at different temperatures. The shape memory effect is evaluated in a fixed force controlled tensile test. Electrospun Nafion nanofibers show excellent shape memory properties upon heat. The shape fixity rates and shape recovery rates are about 95-96% and 87-89% after consecutive three shape memory cycles, respectively. The structure of electrospun nanofibers is stable and reversible for at least three cycles of shape memory tests. These results indicate that shape memory Nafion nanofibers can be used in a wide potential application fields such as smart materials and structures in the future.
The dynamics of drops and attached interfaces for the constrained Allen–Cahn equation

The motion of interfaces for a mass-conserving Allen–Cahn equation that are attached to the boundary of a two-dimensional domain is studied. In the limit of thin interfaces, the interface motion for this problem is known to be governed by an area-preserving mean curvature flow. A numerical front-tracking method, that allows for a numerical solution of this type of curvature flow, is used to compute the motion of interfaces that are attached orthogonally to the boundary. Results obtained from these computations are favourably compared with a previously-derived asymptotic result for the motion of attached interfaces that enclose a small area. The area-preserving mean curvature flow predicts that a semi-circular interface is stationary when it is attached to a flat segment of the boundary. For this case, the interface motion is shown to be metastable and an explicit characterization of the metastability is given.
Accessing the asymmetrical representations of causal relations and hierarchical relations in semantic memory

Recent studies of causal relations have reported faster verification if two words appear in “cause–effect” order than if they appear in “effect–cause” order. The current study investigated whether such differences are specific to causal relations or exist for other types of asymmetric relations, such as hierarchical relations. Participants were asked to decide whether two simultaneously presented words were causally related or hierarchically related, when the word pair was vertically aligned (Experiment 1) or horizontally aligned (Experiment 2). Both causal and hierarchical relationships were verified faster if “cause”/“superordinate-level” appeared vertically above “effect”/“subordinate-level” than the reverse. However, if word pairs were presented horizontally, only causal relationships were verified faster when cause preceded effect. People appear to represent the causal asymmetry based on temporal order when queried about causal relationships, whereas the representation of hierarchical asymmetry is based on spatial arrangement when queried about hierarchical relationships.
Percolation through self-affine surfaces

We study the percolation transition in a long-range correlated system: a self-affine surface. For all relevant physical cases (i.e. positive roughness exponents), it is found that the onset of percolation is governed by the largest wavelength of the height distribution, and thus self-averaging breaks down. Self-averaging is recovered for negative roughness exponents (i.e. power-law decay of the height pair correlation function) and, in this case, the critical exponents that characterize the transition are explicitly dependent on the roughness exponent above a threshold value. Below this threshold, the spatial correlations are no longer relevant. The problem is analytically investigated for a hierarchical network and by means of numerical simulations in two dimensions. Finally, we discuss the application of those properties to mercury porosimetry in cracks.
Rotation in collisional strongly coupled dusty plasmas in a magnetic field

Recent experiments on strongly coupled plasmas in a magnetic field and a background of neutrals have revealed that the dust component exhibits a rigid rotation of order a fraction of a radian/s. The rotation arises spontaneously and seems to be in the direction of ion rotation (which in turn is determined by a competition between E×B and diamagnetic rotations of the ions in the collisional magnetized plasma). In this Letter a possible interpretation of these results, based on the use of fluid equations, is offered.
PID‐Augmented Adaptive Control of a Gyro Mirror Los System

In this paper, a composite control scheme using a synergy of PID and adaptive control is proposed. The adaptive control component provides an adaptive feedforward control signal, while the PID component provides feedback control for robustness against modeling errors in the feedforward control design. The PID control can be automatically tuned using a relay. The control scheme developed is relevant to a large class of nonlinear servo‐mechanical systems, although in this paper, it is specifically implemented and demonstrated on a gyro mirror line‐of‐sight (LOS) system.
Estimation method of homography matrix based on the quantum-behaved particle swarm optimization

Homography matrix is a matric representation of the projective relation between the space plane and its corresponding image plane in computer vision. It is widely used in visual metrology, camera calibration, 3D reconstruction and etc. Therefore, the accurate estimation of the homography matrix is significant. Here, the quantum-behaved particle swarm optimization method, which is global convergent, is first introduced into the estimation of homography matrix. When suited cost function is chosen, enough point correspondences can be utilized to search the optimal homography matrix, which can make the estimation accurately. For the purpose of evaluating the proposed method, simulations and experiments are conducted to confirm the feasibility and robustness. The points obtained from the deviated homography matrix are reprojected to the image plane to evaluate the accuracy. To compare with the proposed method, the Levenberg-Marquardt method, which is a typical iterative minimization method, is utilized to obtain the homography matrix. Simulations and experimental results show that the proposed method is reasonable, accurate, and with an excellent robustness. When 10 correspondences and 20 particles are utilized, the root mean square error of the re-projected points can reach about 0.019 mm. Furthermore, our proposed method is not related with the initialization and less correlated with the chosen cost function, which is the deficiency of the common estimation methods.
Opto-mechanical design of airborne remote sensing instrument

In order to give consideration to both resolution and swath of airborne remote sensing instrument, pan-sharpening method was used to get high resolution pan-sharpened image. This research provides a description of the optomechanical system design and assembly of airborne imager, VCDi-660 (Vegetation and Change Detection imager). Opto-mechanical components of VCDi-660 consist of six optical lenses, focal plane adjustment, bore sight alignment adjustment, filter-exchanging mechanical device and circuit protected housing. An improved adjustment device for bore sight alignment of the multiple-band camera in this Taiwanese airborne imaging sensor, VCDi-660, has been presented. Target of this mechanical device is to provide a translational and rotational movement in the focal plane of VCDi-660. Sensor can be aligned into the best focal position, thus the central point deviations for individual camera module can be less than 3 pixels in both axes in image after alignment.
Transmission mode adaptive beamforming for planar phased arrays and its application to 3D ultrasonic transcranial imaging

A new adaptive beamforming method for accurately focusing ultrasound behind highly scattering layers of human skull and its application to 3D transcranial imaging via small-aperture planar phased arrays are reported. Due to its undulating, inhomogeneous, porous, and highly attenuative structure, human skull bone severely distorts ultrasonic beams produced by conventional focusing methods in both imaging and therapeutic applications. Strong acoustical mismatch between the skull and brain tissues, in addition to the skull's undulating topology across the active area of a planar ultrasonic probe, could cause multiple reflections and unpredictable refraction during beamforming and imaging processes. Such effects could significantly deflect the probe's beam from the intended focal point. Presented here is a theoretical basis and simulation results of an adaptive beamforming method that compensates for the latter effects in transmission mode, accompanied by experimental verification. The probe is a custom-designed 2 MHz, 256-element matrix array with 0.45 mm element size and 0.1mm kerf. Through its small footprint, it is possible to accurately measure the profile of the skull segment in contact with the probe and feed the results into our ray tracing program. The latter calculates the new time delay patterns adapted to the geometrical and acoustical properties of the skull phantom segment in contact with the probe. The time delay patterns correct for the refraction at the skull-brain boundary and bring the distorted beam back to its intended focus. The algorithms were implemented on the ultrasound open-platform ULA-OP (developed at the University of Florence).
Motion of the termination shock in response to an 11 Year variation in the solar wind

A two-dimensional hydrodynamic numerical model has been used to study the motion of the termination shock in response to an 11 year variation in the solar wind ram pressure. We find that for a total variation in the ram pressure by a factor of 2, a termination shock at 89 AU moves inward and outward about ±8% of its distance with a typical velocity of 12 km/sec. This movement may be understood in terms of the various time scales associated with the response of the termination shock and heliopause to variations in the solar wind ram pressure.
DEVELOPMENT OF THE DIRECT BOUNDARY ELEMENT METHOD FOR THIN BODIES WITH GENERAL BOUNDARY CONDITIONS

Abstract A direct boundary element method (DBEM) is developed for thin bodies whose surfaces are rigid or compliant. The Helmholtz integral equation and its normal derivative integral equation are adopted simultaneously to calculate the pressure or the velocity potentialon both sides of thin body, instead of the jump values across it, to account for the different surface conditions of each side. Unlike the usual assumption, the normal velocity is assumed to be discontinuous across the thin body. In this approach, only the neutral surface of the thin body has to be discretized. The method is validated by comparison with analytical and/or numerical results for acoustic scattering and radiation from the surface of a thin body under several conditions: when the surfaces are rigid while stationary or vibrating, and when part of the interior is lined with a sound absorbing material.
Combining independent estimators in research synthesis

Extensive research literatures in the social sciences have led some research reviewers to the use of quantitative methods for research synthesis. The methods used most frequently involve estimation of a standardized mean difference (Glass's effect size). Reviewers frequently wish to examine the relationship between study characteristics (experimental conditions) and effect size. This paper presents asymptotic theory for the analysis of linear models for effect sizes. These procedures can be used to obtain efficient estimates of effect size, fit linear models to effect size data and test model specification.
The application of multiscale morphological filter based on differential image in low-intense x-ray image system

New structure low intensity x-ray image system is mainly made of plane plate mode x-ray intensifier of single proximity focus and CCD data acquisition and processing system. The paper explains the noise source and characteristic of the low intensity x-ray image system. By the system composition, the image noise source of low x-ray imaging system is constituted with quantum noise, particulate noise and dark noise of CCD. Then the compound methods of the "multi-frame mean + morphological transform filter" is submitted which deals with the imaging noise. Firstly, some frame images is superimposed, then mean image is calculated from those images, which is under the principle of noise non-correlation. Secondly, distinguishing with the conventional ways of morphological transformation filtering algorithm, the differential image information is referred to de-noising. Under the multi-scale morphological thought, the differential image which is obtained from the source image includes noise and some image details. After the noise of the differential image is cut off by the wavelet translation, the differential image is added to the last filtered image by the multi-scale morphological filter, then the clean image is achieved which has no noise but keeps the image details.
Chassis mode tuning for electrically small antennas of mobile phones

Nowadays, more attention has been placed on the chassis modes of electrically small antennas. Besides the antenna radiating element itself, the chassis (ground plane) also has non-negligible contribution to the performance of the antenna system. Properly exciting chassis modes can effectively expand antenna’s working bandwidth and improve its radiation efficiency. In this paper, a novel approach of exciting chassis modes will be demonstrated numerically and practically. It can be seen that by tuning the ground plane geometry, desired chassis mode is excited and the antenna performance is improved.
Novel approach to circular-points-based camera calibration

In this paper, we introduce the linear constrains of circular points on camera's intrinsic parameters firstly and propose the uniqueness condition of the solutions, then we elaborate a novel linear approach for computing the images of circular points as well as camera calibration from images of two unparallel coplanar rectangles in space. The main advantage of our technique lies in that neither the metric measurement of the rectangles nor the correspondences between images are required. Extensive simulations and experiments with real images, as well as the comparative study with Zhang's method, validate our algorithms and demonstrate that the proposed technique is of high precision and strong robustness.
XMM-Newton observations of the small magellanic cloud: RX J0105.9-7203, a 726 s Be/X-ray binary pulsar

Aims. To investigate the Be/X-ray binary candidate RX J0105.9-7203 in the Small Magellanic Cloud (SMC), we analysed twenty-two archival XMM-Newton observations around the calibration target 1E 0102.2-7218. Methods. We performed spectral and temporal analyses on the EPIC data of fifteen observations. We disregarded the data of one observation due to high background. The data of the remaining six observations were used to derive upper limits for the flux, because the source intensity was below the detection limit. Results. We detected X-ray pulsations from RX J0105.9-7203 with long periods ranging from 723 ± 2 s to 731 ± 1 s in almost all observations where the source luminosity was above 8.0 $\times$ 10 34 erg s -1 . The pulse profiles show more complex features in earlier observations whereas only a broad main pulse is seen at later times. The X-ray spectrum is well modelled by a power-law with photon index 0.71 ± 0.13 and a moderate absorption with N H = (4.6 ± 3.0) $\times$ 10 21 cm -2 . However, during one observation the source was extremely high absorbed: N H = (2.6 ± 1.7) $\times$ 10 23 cm -2 . The longterm X-ray lightcurve (covering 7.5 years) shows variations by at least a factor of 2. A long period of relative brightness (~1300 days) until Nov. 2003 was followed by an interval when RX J0105.9-7203 was very faint or not detected at all. Timing analysis of OGLE data of the optical counterpart revealed peaks in the FFT power-spectrum at 2.35 and 3.2 days.
Surface phonon dispersion in graphite and in a lanthanum graphite intercalation compound

Using high-resolution electron energy-loss spectroscopy the surface-phonon dispersion of graphite has been determined in the \ensuremath{\Gamma}K direction over the whole energy range and the whole Brillouin zone. Born\char21{}von Karman model calculations are used to describe the dispersion relations. An unexpected result is the splitting of the ZA and ZO mode at the K point. Following a previously introduced procedure to form in situ rare-earth graphite intercalation compounds (GIC), which for lanthanum results in an intermediate carbide phase, we prepared this carbidic phase and the final GIC-like phase. The carbide shows five dispersionless features that may be attributed to Einstein modes of graphite islands. The phonon dispersion of the final phase shows the same modes as graphite shifted in energy: softening of the optical and stiffening of the acoustical phonons occurs. This is described within a Born\char21{}von Karman model by weakening the nearest-neighbor interaction and strengthening the second-nearest-neighbor interaction. The evolution of the phonon dispersion gives a first hint that the GIC-like phase may develop in two stages: first a monolayer graphene on top of the carbide and then the very thin GIC layer.
Vitamin D status and cardiometabolic disease risk among healthy adults of Northern Ghana

Cardiometabolic Disease (CMD) is a cluster of conditions that increase the risk for cardiovascular events, but its relationship with vitamin D status has not been studied in Ghana. A cross-sectional study design was conducted to investigate the relationship between serum vitamin D status and CMD risk (obesity, type 2 diabetes mellitus, hypertension, and dyslipidemia) among 302 apparently healthy adults, aged 25 to 59 and of northern decent in Ghana. Biochemical analysis was done to determine serum total cholesterol (TC), Triglycerides (TG), High Density Lipoprotein (HDL), Low Density Lipoprotein (LDL), Fasting Blood Glucose (FBG), Glycated Haemoglobin (HbA1c) and serum vitamin D levels of participants. Anthropometric assessment was also done and BMI, WC, HC, Blood Pressure, WHR, Body Fat (BF) and visceral fat percentages were obtained. Analysis was done using SPSS (version 25). We evaluated CMD risk factors to predict vitamin D status using binary and multiple linear logistics regression analysis. Similar between gender, participants mean age was 38.78years (SD 10.42years). The females had higher BMI (24.31 SD 7.96 versus 22.52 SD 3.07 kgm2, p=0.006), % total body fat (24.31 SD 7.96 versus 22.52 SD 3.07%, p=0.001), WC (24.31 SD 7.96 versus 22.52 SD 3.07 inches, p=0.002), and HC (24.31 SD 7.96 versus 22.52 SD 3.07, p=0.002 inches) than the males, while the males had higher mean total cholesterol (5.74 SD 1.02 versus 3.57 SD 1.02) and LDL (5.40 SD 1.05, verse 3.22 SD 1.09, p=0.005) than the females. Serum vitamin D levels was significantly associated with age (p= 0.047) but not gender (p=0.349). Overall, 6.4% of participants had CMD, representing 10.2% of the females, and no male. Multivariate analysis reveals gender, average BP, FBG, and % total body fat to significantly affect serum vitamin D concentrations. Seven percent (7%) of participants were serum vitamin D deficient (VDD) and 28.5% had serum vitamin D insufficiency (VDI), similar by gender, but increased with age (p=0.047). Both mean SBP (P<0.0001) and DBP (p<0.0001) increased with VDD, while means of FBS (p=0.032), BMI (p=0.004), HbA1c (p=0.040), and LDL (p=0.047) are highest in the VDD group and least in the Vitamin D Sufficient (VDS) group. Binary Logistic regression showed participants with high SBP (OR= 0.055; 95% CI= 0.008-0.361; p= 0.003) and high FBS (OR= 0.076; 95% CI= 0.014-0.404; p= 0.002) had increased odds of VDD compared with normal levels of SBP and FBS. Multiple logistics regression showed FBG, TG, LDL and WC significantly predicted CMD. In conclusion, CMD risk factors were common among the participants and more than a third were vitamin D deficient or insufficient. Individual CMD risk factors increased with vitamin D deficiency, but CMD did not predict serum vitamin D status.
Practical considerations when using sparse grids with Bayesian inference for parameter estimation

When estimating parameters it is important to determine both the most probable values and the confidence intervals. To do so accurately requires Bayesian inference that can involve a high computational cost for complex models, particularly if the range of possible parameter values is large. One approach is to sample the model response surface and to interpolate. When done with a tensor grid the cost of developing an accurate representation of the surface and to locate the point of greatest probability can be prohibitively expensive. Sparse grids offer an alternative that may be of less cost. Because sparse grids are inherently approximations it is important to determine the accuracy of the representations since the errors may lead to less efficient calculations in estimating parameters and may distort the marginal probability distributions of the parameters. Except for atrociously ill-conditioned inverse problems sparse grids are particularly well suited for use with the least-squares approach and are even better for Bayesian inference and the detection of the cause of ill-conditioning.
Theoretical models of interstellar shocks. I - Radiative transfer and UV precursors

We construct theoretical models of interstellar radiative shocks, with special attention to the transfer of ionizing radiation. These models are ''self-consistent'' in the sense that the emergent ionizing radiation (the UV precursor) is coupled with the ionization state of H, He, and the metals in the preshock gas. For shock velocities upsilon/sub s/> or =110 km s/sup -1/ the shocks generate sufficient UV radiation for complete preionization of H and He (to He/sup +/). At lower velocities the preionization can be much smaller, with important consequences for the cooling function, the shock structure, and the emission. For models with 40 km s/sup -1/< or =upsilon/sub s/< or =130 km s/sup -1/ we tabulate the intensities of the strongest emission lines in the UV, optical, and infrared, as well as postshock column densities of metal ions potentially observable by UV absorption spectroscopy. Possible applications to supernova remnants and high-velocity interstellar gas are assessed.
One-Sided Stress Wave Velocity Measurement in Concrete

Measurement of the velocity of stress waves in concrete provides valuable information on the state of the material. Recently, a number of papers have been published on wave velocity measurements in concrete when access to only one surface of the structure is possible, such as for the case of concrete pavements. In this paper, the existing one-sided methods for stress wave measurement in concrete are reviewed. Then, a modified method for one-sided stress wave velocity determination in concrete is introduced; the novel aspect of the modified technique is the data collection and processing system, which more accurately determines the arrival of the generated longitudinal and surface waves. The modified method, which is demonstrated on a variety of materials including steel, PMMA, and concretes of varying composition, is shown to be superior to existing one-sided techniques. Using the developed technique, the significant effect of the moisture content gradient within concrete on one-sided velocity measurements is demonstrated. Finally, one-sided velocity measurements are shown to be useful for monitoring the strength gain of early age concrete.