Miracle-dz/UniFAR-FTUs huggingface dataset:
Creeping flow in two-dimensional channels

Creeping flow in two-dimensional periodic channels of arbitrary geometry is considered. The problem is formulated using the boundary-integral method for Stokes flow, presently adapted for periodic flows with special geometrical characteristics. Numerical calculations for steady flow in channels constricted by a plane and a sinusoidal wall are performed. Detailed streamline patterns are presented and criteria for flow reversal are established. It is shown that for narrow channels the mechanism driving the flow has a strong effect on the structure of the flow. The results are discussed with reference to lubrication, coating and molecular-convective processes.
Friction stir welding of al 6061‐T6 thick plates: Part I ‐ experimental analyses of thermal and mechanical phenomena

Abstract In friction stir welding (FSW), heat is generated by two mechanisms: (1) the friction between the rotating tool and the workpiece at the interface, and (2) the plastic shear deformation of the material in the vicinity of the pin tool. The amount of heat generated is crucial to the quality of the weld. In addition, the mechanical force and torque developed in the process dictates the life of the tool as well as the design of the fixture. In this paper, a butt joint was made by FSW on two thick plates (thickness = 37.6 mm) of aluminum alloy 6061‐T6. The joining was conducted by load control mode (applying a controlled vertical plunging force). Two different tests were performed, one using a long probe pin (24.3 mm in length) and the other using a very short pin (3.5 mm in length). The objectives of the research were to study the heat generation process from the shoulder, the pin, and the mechanical process parameters. In this Part I, we report on the welding process parameters, i.e. tool RPM, welding speed, tool plunge‐in depth, force, torque, and power history, and the transient temperature history measured from thermocouples. It was found that (a) a quasi‐steady state existed after the tool moved about 82.2 mm from the starting point, during which the tool forces, torque and generated heat reached an equilibrium state in the neighborhood of the tool, (b) the highest temperature measured in the weld seam was less than the melting temperature of the workpiece material, (c) the tool pin plays an important role in the heat input to the process, and (d) the heat generated from the pin strongly depends on its length. The comprehensive test data could be used by researchers interested in numerical modeling of the FSW process without duplicating the complicated tests.
How Does the Boundary Layer Contribute to Eyewall Replacement Cycles in Axisymmetric Tropical Cyclones

AbstractThree diagnostic models of the axisymmetric tropical cyclone boundary layer, with different levels of approximation, are applied to the problem of tropical cyclones with concentric eyewalls. The outer eyewall is shown to have an inherently stronger frictional updraft than the inner because it is in an environment of lower vorticity. Similarly, a relatively weak local enhancement of the radial vorticity gradient outside the primary radius of maximum winds can produce a significant frictional updraft, even if there is no outer wind maximum. Based on these results, it is proposed that the boundary layer contributes to the formation of outer eyewalls through a positive feedback among the local enhancement of the radial vorticity gradient, the frictional updraft, and convection. The friction-induced secondary circulation associated with the inner eyewall is shown to weaken as the outer wind maximum strengthens and/or contracts, so boundary layer processes will contribute, along with the heating-induced.
Simultaneous L/sub p/-stabilization and internal stabilization of linear systems subject to input saturation - state feedback case

We consider the problem of simultaneous finite gain L/sub p/-stabilization and internal stabilization of linear systems subject to input saturation via linear static state feedback. We show that bounded input finite-gain L/sub p/-stabilization and local asymptotic stabilization can always be achieved simultaneously no matter where the poles of the open loop system are, and the locations of these poles play a role only when bounded input finite gain L/sub p/-stabilization and global or semi-global stabilization are required simultaneously. <<ETX>>
Restriction of Range and Correlation in Outlier-Prone Distributions

Statistical theory indicates that restriction of the range of possible values of normally distributed variables, and many non-normal variables, reduces correlations in unrestricted populations. Contrary to this typical outcome, results of a simulation study show that range restriction sometimes increased the correlation between variables having outlier-prone distributions. This result occurred in the case of exponential and ex-Gaussian distributions, which are encountered in experimental studies involving response times. It did not occur in truncated versions of the same densities. Chance occurrence of outliers in contaminated-normal, or mixed-normal, distributions reduced the correlation found between samples from uncontaminated populations. Conversely, detection and downweighting of outliers increased the magnitude of sample correlations, and a similar result occurred for many other outlier-prone distributions. Practical implications of these findings are discussed.
A study on switching of the transfer functions focusing on sound quality

Many papers have described moving sound image schemes that use loudspeakers or headphones. Since most of these schemes switch the spatial transfer function being used, wave discontinuity occurs at the moment of switching, which degrades the sound quality. While the characteristics of the wave discontinuity depend on the moving sound image scheme used, no paper appears to have considered the relationship between the wave discontinuity and the scheme used. To rectify this omission, this paper examines three approaches: the simple switching approach, the overlap-add approach, and the fade-in·fade-out approach. The sound degradation caused by the wave discontinuity is assessed, and an objective measure, spectrum distortion width, is introduced to quantify the wave discontinuity. Subjective assessments, carried out using Scheffe’s comparison tests, verify that the overlap-add approach with modified hamming window and the fade-in·fade-out approach were better than the other methods.
Shedding light on low-surface-brightness Galaxies in dark energy surveys with transformer models

Low-surface-brightness galaxies (LSBGs), which are defined as galaxies that are fainter than the night sky, play a crucial role in our understanding of galaxy evolution and in cosmological models. Upcoming large-scale surveys, such as Rubin Observatory Legacy Survey of Space and Time (LSST) and Euclid, are expected to observe billions of astronomical objects. In this context, using semi-automatic methods to identify LSBGs would be a highly challenging and time-consuming process, and automated or machine learning-based methods are needed to overcome this challenge. We study the use of transformer models in separating LSBGs from artefacts in the data from the Dark Energy Survey (DES) data release 1. Using the transformer models, we then search for new LSBGs from the DES that the previous searches may have missed. Properties of the newly found LSBGs are investigated, along with an analysis of the properties of the total LSBG sample in DES. We created eight different transformer models and used an ensemble of these eight models to identify LSBGs. This was followed by a single-component S\'ersic model fit and a final visual inspection to filter out false positives. Transformer models achieved an accuracy of $ in separating the LSBGs from artefacts. In addition, we identified 4\,083 new LSBGs in DES, adding an additional $ $ to the LSBGs already known in DES. This also increased the number density of LSBGs in DES to 5.5 $. The new LSBG sample consists of mainly blue and compact galaxies. We performed a clustering analysis of the LSBGs in DES using an angular two-point auto-correlation function and found that LSBGs cluster more strongly than their high-surface-brightness counterparts. This effect is driven by the red LSBG. We associated 1310 LSBGs with galaxy clusters and identified 317 ultradiffuse galaxies (UDGs) among them. We found that these cluster LSBGs are getting bluer and larger in size towards the edge of the clusters when compared with those in the centre. Transformer models have the potential to be equivalent to convolutional neural networks as state-of-the-art algorithms in analysing astronomical data. The significant number of LSBGs identified from the same dataset using a different algorithm highlights the substantial impact of our methodology on our capacity to discover LSBGs. The reported number density of LSBGs is only a lower estimate and can be expected to increase with the advent of surveys with better image quality and more advanced methodologies.
Analyzing Change: Measurement and Explanation Using Longitudinal Data.

Preface The Concept of Change Ways of Measuring Change Models for the Description and Explanation of Relative Change Causal Models for Change The Effects of Measurement Error on Models for Change Models for Change when the Data are Categorical (1) Models for Change when the Data are Categorical (2) Models for Data Collected on Three or More Occasions Models for Transition and Duration Miscellaneous Topics and Conclusions References Author and Subject Index.
Loss of the Vitamin D Receptor in Human Breast Cancer Cells Promotes Epithelial to Mesenchymal Cell Transition and Skeletal Colonization

Expression of the vitamin D receptor (VDR) is thought to be associated with neoplastic progression. However, the role of the VDR in breast cancer metastasis to bone and the molecular mechanisms underlying this process are unknown. Employing a rodent model (female Balb/c nu/nu mice) of systemic metastasis, we here demonstrate that knockdown of the VDR strongly increases the metastatic potential of MDA‐MB‐231 human breast cancer cells to bone, resulting in significantly greater skeletal tumor burden. Ablation of VDR expression promotes cancer cell mobility (migration) and invasiveness, thereby facilitating skeletal colonization. Mechanistically, these changes in tumor cell behavior are attributable to shifts in the expression of proteins involved in cell adhesion, proliferation, and cytoskeletal organization, patterns characteristic for epithelial‐to‐mesenchymal cell transition (EMT). In keeping with these experimental findings, analyses of human breast cancer specimens corroborated the association between VDR expression, EMT‐typical changes in protein expression patterns, and clinical prognosis. Loss of the VDR in human breast cancer cells marks a critical point in oncogenesis by inducing EMT, promoting the dissemination of cancer cells, and facilitating the formation of tumor colonies in bone. © 2019 American Society for Bone and Mineral Research.
Concerned about their learning: mathematics students with chronic illness and their teachers at school

Chronic illness often goes hand-in-hand with absence from school, and students miss out on learning opportunities at school for extended or accumulative periods of time. Many young people seek to continue their school studies nonetheless. The need to consider viable ways to support them academically arose in the context of a project called Link ‘n Learn funded by an Australian Research Council Linkage grant (2008–2010). This paper reports on one aspect of the project – an in-depth qualitative case study of 22 participants: senior secondary students with diverse types of chronic illness who were continuing their studies during absence from school and their mathematics teachers. The study found that the students’ concerns centred on academic issues – their perceived need for support from and interaction with their teachers. The teachers' concerns focused on medical issues – their students having to manage illness. Facilitators of these students' ability to continue studying included their ambition, perseverance with independent learning, initiative in seeking help, and quick recovery from medical treatment cycles. Teacher-related facilitators included the teachers' willingness to interact using communication media, confidence in initiating contact, and ability to modify their students' learning programme. Other facilitators included a responsive school technology department, technology tutoring from students, and the involvement of family members or tutors. Outcomes for students and teachers of their interactions with each other during lengthy periods of absence, and implications for schools, are discussed.
Indian MST radar 1. System description and sample vector wind measurements in ST mode

An MST radar operating at 53 MHz with an average power aperture product of 7 × 108 W m2 has been established at Gadanki (13.5°N, 79.2°E), India. The radar development has been accomplished in two phases. In the first phase it was commissioned in ST mode using a partial system comprising one quarter (16 × 16)of the Yagi antenna array and 16 driver units of the transmitters providing an average power aperture product of 4.8 × 106 W m2. In this part we present the radar system description, including off-line data processing, and some sample high-resolution vector wind measurements made in ST mode operation.
Intensity of X-ray Diffraction by a One-dimensionally Disordered Crystal (II) General Derivation in the Case of the Correlation Range s≥2.

The general intensity equation for X-rays diffracted by a one-dimensionally disordered crystal i.e. \(I{=}N\text{Spur}\ \textbf{\itshape V}\textbf{\itshape F}+\sum\limits_{n{=}1}^{N-1}(N-n)\text{Spur}\ \textbf{\itshape V}\textbf{\itshape F}\textbf{\itshape Q}^{n}+\text{conj. }\) which was derived for the correlation range s =1 was found to be valid for any s -value by modifying slightly the elements of the matrices. \(\overline{S_{j}S_{j+n^{*}}}\) as used by Wilson and Jagodzinski was shown to be equal to Spur V F P n for any s -value. In our present method, layer form factors are refered to single layers and the preceding ( s -1) layers are used only to classify them into r l subgroups where r is the number of the kinds of layers and l that of combinations of ( s -1) preceeding layers. This method which we call the “antecedent” one is found to be equivalent to another one as used by Hendricks and Teller in which each layer form factor is taken over the whole s layers hence there are R = r l different laye.
Optimum biased coin designs for sequential clinical trials with prognostic factors

Patients in a clinical trial arrive sequentially and are assigned to one of t treatments. This assignment should maintain a balance between the numbers receiving each treatment, yet should be sufficiently random to avoid any suspicion of conscious or unconscious cheating. To balance these requirements Efron (1971) introduced biased coin designs for the comparison of two treatments in which allocation of the treatment is determined probabilistically, but with a bias towards the underrepresented treatment. One disadvantage of Efron's scheme is that it does not include balance over covariates or prognostic factors which may affect the response of the patient to the treatment. Biased coin schemes which do force balance over both treatments and prognostic factors are given by Pocock & Simon (1975) and Efron (1980). The properties of the designs have been elucidated by numerical studies and they are now being increasingly used in clinical trials. Reviews of the literature and discussions of the practical implications of the designs are given by Pocock (1979) and Simon (1979). However, the designs suffer from the disadvantage that they rely on arbitrary functions to achieve the desired balance. The procedures thus lack a firm theoretical framework. An alternative approach in the presence of prognostic factors (Begg & Iglewicz, 1980) uses optimum design theory to suggest a deterministic design criterion, which is then modified for computational convenience. In this paper I use optimum design theory to provide a procedure of the biased coin type for an arbitrary number of treatments in the presence, or absence, of prognostic factors. This has the theoretical advantage of obviating dependence on a series of arbitrary functions. The necessary optimum design theory is presented in ? 2 and, in ? 3, applied to biased coin experiments. The simplest case, that of two treatments in the absence of prognostic factors, is studied in ? 4. The extension to three or more treatments is in ? 5, followed, in ? 6, by the allowance for prognostic factors. Although, in the biased coin designs, allocation of treatments is made probabilistically, the results of the paper can be used for the sequential construction of DA-optimum designs in which randomization is not introduced by the experimenter. All the designs mentioned so far are sequential, but not adaptive. In the useful distinction made by Pericchi (1981), they are data-dependent but not outcomedependent: each allocation depends on the previous allocations and prognostic factors,
Correlation of weather parameters with sodar-derived Cn2 profiles

Optical turbulence measurements have been performed at North Oscura Peak, White Sands Missile Range using a variety of precision instruments. A commercially available sodar system is used to collect atmospheric profiles, which are calibrated with fine-wire probes to calculate the optical index of refraction structure parameter, Cn2, from a height of 15 meters to around 160 meters above the ground.
Competitive learning and winning-weighted competition for optimal vector quantizer design

It is essential to build a nonparametric model to estimate a probability density function p(x) in the areas of vector quantization, pattern recognition, control, and many others. A generalization of Kohonen learning, the winning-weighted competitive learning (WWCL), is presented for a better approximation of p(x) and fast learning convergence by introducing the principle of maximum information preservation into the learning. The WWCL is a promising alternative and improvement to the generalized Lloyd algorithm (GLA) which is an iterative descent algorithm with a monotonically decreasing distortion function towards a local minimum. The WWCL is an online algorithm where the codebook is designed while training data is arriving and the reduction of the distortion function is not necessarily monotonic. Experimental results show that the WWCL consistently provides better codebooks than the Kohonen learning and the GLA in distortion or convergence rate. <<ETX>>
Forecasting Stock Market Price Using Deep Neural Networks

Investors in the stock market expect to make their profits, meaning they are looking for a profit by buying a share at low prices and selling it to the highest level, which requires stock price prediction. Significant challenges arise due to the non-linear and chaotic nature of stock markets when predicting prices in time series. In this research, unsupervised methods were used for the reduction of the input dimension and creating indicators. In the next step, the output of the unsupervised model was fed as input into the Jordan Recursive Neural Network(JRNN) to predict the closing price of the upcoming day. To illustrate the functionality and superiority of the proposed algorithm, data from three different and challenging stock symbols of Nasdaq were used. Ultimately, the model was evaluated with mean square error and mean absolute percentage error.
Parameter identification of blur image based on image gradient

Restoration of a degraded image from motion blurring is highly dependent on the estimation of the point spread function, which depends on the blur orientation and the blur extent. In this paper, we present a spectral analysis of image gradients, which has more strong periodic strips compare the spectrum of image. The experiments on simulated images show that our algorithm is capable of accurately identifying the blurring kernel for a wider range of blur orientation and blur extent. Furthermore, it’s been proved to be more robust to noise over available techniques.
Spin polarisation of photoelectrons ejected from unpolarised atoms

The photoelectrons ejected from unpolarised atoms by polarised or unpolarised light are usually spin polarised. The polarisation for the (nl)N subshell, with l>or=1 and 1<or=N<or=4l+2, arises from spin-orbit splitting at the initial and (or) final states. To observe this polarisation it is necessary to select the photoelectrons corresponding to the transition from a particular fine-structure level of the initial state to a particular fine-structure level of the final state. The effect exists at all photon energies. The degree of polarisation depends on the energy and polarisation of the photons, the angle of electron ejection and the atomic characteristics. After integration over the electron ejection angles the degree of polarisation becomes equal to zero when unpolarised or linearly polarised light is absorbed and remains non-zero for absorption of circularly polarised light. The degree of polarisation of the photoelectrons ejected from the 2p6 and 3p6 subshells of Ar and the 4d10 and 5p6 subshells of Xe, calculated in the random-phase approximation with exchange, is presented.
Effects of some physical factors on the inhomogeneity in planar symmetry

This paper is devoted to identify some physical causes of energy density inhomogeneity and stability of self-gravitating relativistic fluids in plane symmetry such as Weyl tensor, local anisotropy, dissipative terms and their specific combination. We first develop a relationship between matter variables and the Weyl tensor and then formulate dynamical equations using Bianchi identities. For the non-dissipative dust fluid, we conclude that the system will remain homogeneous if and only if it is conformally flat which implies the shear-free condition. However, the converse is not true for the non-dissipative isotropic fluid. For non-dissipative anisotropic fluid, the inhomogeneity factor is identified to be one of the structure scalars. A particular case of geodesic with dissipation is also discussed.
A new infrared image processing method based on compressed sensing

In order to improve the efficiency of processing the large amount of data of infrared image, in this paper we develop a new infrared image processing method based on compressed sensing (CS) and simulate the method. The basic idea behind CS is that a signal or image, unknown but supposed to be compressible by a known transform, (eg. wavelet), can be subjected to fewer measurements than the nominal number of pixels, and yet be accurately reconstructed. According to the properties of wavelet transform sub-bands, firstly we make wavelet transform which change the infrared image into a wavelet coefficients matrix. Acquired the features of infrared image, the characters of the wavelet coefficients can be concluded. When deeply analyzing the data of the wavelet coefficient, we can easily find the high-pass wavelet coefficients of the image are sparse enough to measure, while the low-pass wavelet coefficients are not appropriate for measure. So in this second part, only measured the high-pass wavelet coefficients of the image but preserving the low-pass wavelet coefficients. For the reconstruction, the third part, by using the orthogonal matching pursuit (OMP) algorithm, high-pass wavelet coefficients could be recovered by the measurements. Finally the image could be reconstructed by the inverse wavelet transform. The simulation proves that applying the CS theory to the realm of infrared picture can decrease the amount of data which must be collected. Besides, compared with the original compressed sensing algorithm, simulation results demonstrated that the proposed algorithm improved the quality of the recovered image significantly.