Miracle-dz/UniFAR-FTUs huggingface dataset:
A theory of turbulent flow round two-dimensional bluff bodies

By generalizing the theory of ‘rapid distortion’ of turbulence developed by Batchelor & Proudman (1954) it is shown in this paper that the turbulent velocity around a bluff body placed in a turbulent flow can be calculated outside and upstream of the regions of separated flow, if the incident turbulent flow satisfies the following conditions: (i) if a/Lx [Lt ] 1 or = O(1), Re−1 $u^{\prime}_{\infty}/\overline{u}_{\infty} $ [Lt ] 1 [Lt ] Re½; (ii) if a/Lx [Gt ] 1, Re−1 [Lt ] $u^{\prime}_{\infty}$ [Lt ] 1/(a/Lx) and Re [Gt ] (a/Lx)2, where $Re = \overline{u}_{\infty} a/ν$, is the mean uniform incident velocity, $u^{\prime}_{\infty}$ is the r.m.s. velocity of the homogeneous incident turbulence, a is a transverse dimension of the body (the radius in the case of a circular cylinder), Lx is the integral scale of the incident turbulence and v is the kinematic viscosity. Detailed calculations are given for the flow around a circular cylinder with particular emphasis on the turbulence very close to the surface. (The results can be generalized to other cylindrical bodies.) Mean-square values and spectra of velocity have been found only in the limiting situations where the turbulence scale is very much larger or smaller than the size of the body, i.e. Lx [Gt ] a or Lx [Lt ] a. But, whatever the value of a/Lx, if the frequency is sufficiently large the results for spectra tend to those of the limiting situation where Lx [Lt ] a. The reason why the turbulence velocities have not been calculated for intermediate values of a/Lx is that closed-form solutions cannot be found and that the computing time then required is quite excessive. However, some computed results are used in the paper to suggest the qualitative behaviour of the turbulence when Lx is of order a. An important result of the theory is that it illuminates and distinguishes between the governing physical processes of distortion of the turbulence by the mean flow, the direct ‘blocking’ of the turbulence by the body, and concentration of vortex lines at the body's surface. The results of the theory have many applications, for example in calculating turbulent dispersion and fluctuating pressures on the body, as shown elsewhere by Hunt & Mulhearn (1973) and Hunt (1973). In conclusion the theoretical results are briefly compared with experimental measurements of turbulent flows round non-circular cylinders. A detailed comparison with measurements round circular cylinders will be published later by Petty (1974).
Linear quadratic optimal learning control (LQL)

A learning control solution to the problem of finding a finite-time optimal control history that minimizes a quadratic cost is presented. Learning achieves optimization without requiring detailed knowledge of the system, which may be affected by unknown but repetitive disturbances. The optimal solution is synthesized one basis function at a time, reaching optimality in a finite number of trials. These system-dependent basis functions are special in that: 1) each newly added basis function is learned without interfering with the previously optimized ones, and 2) it is extracted using data from previous learning trials. Numerical and experimental results are used to illustrate the algorithm.
Randomness extraction from a chaotic laser diode with dispersive self-injection

High-speed generation of random bits has attracted much attention recently using chaotic dynamics in laser diodes subject to different perturbations. Extraction of randomness has been investigated from a chaotic laser using selfinjection from a grating with dispersion. While the optical feedback invokes chaos, the dispersion induces different delays to different frequency components to conceal the information of the feedback delay time. Experimentally, random bits were extracted using a laser under feedback from a grating. The undesirable time-delay signature (TDS) was reduced by about 10 times. So a continuously tunable sampling rate was allowed for random bit generation (RBG), where the overall output rate tunable across 3 orders of magnitude up to 100 Gbps was demonstrated. Numerically, the concealment of TDS is further investigated using a rate-equation model incorporating self-injection through an all-pass filter (APF), which is realized by coupling the feedback path to a lossless ring cavity. While the APF provides dispersion to suppress the TDS, the APF provides no frequency selectivity so that a large chaotic bandwidth is attained. For minimal TDS, the coupling ratio to the ring is optimized at 0.5. The round-trip time of the ring also needs to be sufficiently long for inducing dispersion in the chaotic light. With comparable performance in TDS suppression, the APF feedback can generate chaos with broader bandwidth than grating feedback. The results are applicable to generating random bits for digital systems with widely tunable rates.
Extended mean-distance-ordered search using multiple l/sub 1/ and l/sub 2/ inequalities for fast vector quantization

Mean-distance-ordered search (MOS) algorithms were proposed as a fast and efficient method for vector quantization (VQ) encoding. However, the efficiency of MOS algorithms is limited because they use only one inequality in reducing the search region. Therefore, we propose an extended MOS algorithm using multiple anchor vectors which exploits multiple l/sub 1/ and l/sub 2/ inequalities to reduce the search region further. We also describe a greedy algorithm for selecting an anchor vector set that reduces the computational cost of the extended MOS algorithm. For eight test images, the number of operations required in the extended MOS algorithm was 66.2% of that in the previous MOS algorithm on the average when the codebook size is 256, while producing the same encoding quality to that of the full-search VQ.
The Parkes Survey of 21-CENTIMETER Absorption in Discrete-Source Spectra. II. Galactic 21-CENTIMETER 0BSERVATIONS in the Direction of 35 Extragalactic Sources

A detailed comparison of emission and absorption spectra obtained in the direction of extragalactic sources permits an unambiguous separation of the contribution from a diffuse, high-temperature, optically thin component and that from denser and colder local concentration of hydrogen. The concentrations have a mean column density N Hc ≈ 3 × 10 20 atoms cm -2 and a spin temperature T s ≈ 60°-80° K. They are typically separated along a line of sight by one full scale-thickness of the galactic disk. The diffuse intercloud medium has a column density N Hi ≈ 1.4 × 10 20 cosec |b| atoms cm -2 , a spin temperature in excess of 750° K, and contains half of the total mass of hydrogen in the solar neighborhood.
Efficient generation of divergence-free fields for the finite element analysis of 3D cavity resonances

Spurious modes can be eliminated from the finite element solutions of three-dimensional resonant cavities by imposing solenoidality. The addition of a penalty term to the functional has the effect of pushing the spurious modes out of the range of interest. This approach is preferred because it does not destroy matrix sparsity; however, the selection of a suitable penalty parameter is difficult. A method is presented that allows for one penalty parameter per mode instead of one overall and adjusts the parameters automatically as the modes are computed. Results of using the method to analyze empty and dielectric-loaded cavities are presented. >
Polydopamine nanoparticle-mediated mild photothermal therapy for inhibiting atherosclerotic plaque progression by regulating lipid metabolism of foam cells

Abstract Since apoptosis of foam, cells can induce plaque instability, reducing intracellular lipid content while protecting foam cells from apoptosis is beneficial for the safe and efficient therapy of atherosclerosis. In this study, osteopontin-coupled polydopamine (PDA-OPN) nanoparticles were synthesized and applied to target mild photothermal therapy (PTT) of atherosclerosis. The results from laser confocal microscopy indicate that PDA-OPN nanoparticles can be specially recognized and absorbed by foam cells. Under near-infrared laser irradiation, the mild photothermal generated by PDA-OPN decreases intracellular lipid accumulation but does not induce cell apoptosis. In vivo treatments demonstrate that mild PTT can substantially reduce plaque area and improve plaque stability by upregulating the expression of plaque fibrosis in ApoE−/− mice. Our findings reinforce that the PDA-OPN nanoparticle-mediated mild PTT can inhibit atherosclerotic progression, which provides new insights for developing safe and effective treatment methods for atherosclerosis.
Selective excitation of vortex fibre modes using a spatial light modulator

A controllable excitation of fibre modes is examined theoretically and experimentally. We verify that the modes of a few-mode fibre can be selectively excited by means of a spatial light modulation of a laser beam focused to the fibre. The proposed method is demonstrated on a dynamical switching, phase coupling and weighted mixing of LP01, LP11 and LP21 modes, achieved by an exchange of computer-generated holograms sent to the spatial light modulator. The possibility to excite a vortex fibre mode with a well-defined azimuthal phase dependence is also verified. It is promising for an encoding and transfer of information by vortices in fibre communications.
Ordered orbits of the shift, square roots, and the devil's staircase

Abstract An orbit of the shift σ: t ↦ 2t on the circle = ℝ/ℤ is ordered if and only if it is contained in a semi-circle Cμ = [μ, μ+½]. We investigate the ‘devil's staircase’ associating to each μ ε the rotation number ν of the unique minimal closed σ-invariant set contained in Cμ; we present algorithms for μ in terms of ν, and we prove (after Douady) that if ν is irrational then μ is transcendental. We apply some of this analysis to questions concerning the square root map, and mode-locking for families of circle maps, we generalize our algorithms to orbits of the shift having ‘sequences of rotation numbers’, and we conclude with a characterization of all orders of points around realizable by orbits of σ.
"The Estimation of the Instantaneous Amplitudes and the Instantaneous Frequencies of the EEG when both are Stochastic Process"

: In this report we model the EEG signal as a sum of sine waves. Each sine wave has a random frequency and a random amplitude. We use band pass filters to separate the different frequency segments of the EEG. The frequency is modeled as an Ornstein-Uhlenbeck (OU) stochastic process i.e. the frequency is bouncing around a mean value. In each EEG band, an adaptive filter is developed to estimate the random frequency. The instantaneous amplitude is then obtained by using adaptive noise cancelling where one channel is the EEG band pass signal and the other channel is the estimated sine wave with random frequency. Another amplitude estimate is obtained by using energy separation operator with the estimated frequency. The results are compared to the Teager energy separation operator (TEO) and showed better performance.
Granular Foveolae in the Groove of the Sigmoid Sinus: An Anatomical Study

Background Granular foveolae in the groove of the sigmoid sinus have rarely been reported in the literature compared to numerous published reports on the granular foveolae near the superior sagittal sinus and its sulcus on the internal aspect of the calvaria. The present study was performed to better elucidate their prevalence and locations. Materials and methods One hundred and ten adult dry skulls (220 sides) were analyzed for the presence of granular foveolae within the groove of the sigmoid sinus. The exact position of the foveolae was documented, and the diameter of the granular foveola was measured. Results Granular foveolae were found in the groove of the sigmoid sinus on 3.6% of the sides. These were at or within a mean of 1.3 cm inferior to the transverse-sigmoid junction. When a mastoid foramen was noted in the groove, it was always located inferior to the granular foveolae when present. The mean diameters of the granular foveolae of the left groove of the sigmoid sinus were 2.8 mm and 4 mm for the right grooves. The mean depth of the granular foveolae in the left groove of the sigmoid sinus was 2.7 mm and 3.5 mm for the right grooves. Granular foveolae were statistically larger and deeper on the right versus left sides (p<0.05). Conclusions Granular foveolae of the groove of the sigmoid sinus were identified most commonly on the right sides and 3.6% on all sides. If identified on medical imaging, these uncommon structures at the skull base should be considered normal anatomical variations.
Geometry-dependent magnetization reversal mechanism in ordered Py antidot arrays

Arrays of Permalloy antidot thin films have been prepared by sputtering onto hexagonally ordered anodic alumina templates. Geometry parameters of antidot arrays have been tailored so that, final diameter ranges between 35 and 66 nm, and film thickness is tuned between 18 and 138 nm while the hexagonal symmetry lattice is kept constant to 105 nm. Magnetic characteristics have been investigated by vibrating sample magnetometry, magneto-optic Kerr effect and magnetic force microscopy imaging. The magnetization process has been analysed as a function of the mentioned geometry parameters that determine the main magnetic energy contribution that is the stray-field energy coming from local distribution of magnetic charges around the antidots. The magnetization reversal mechanism is concluded to be due to displacements of domain walls for thick films while its motion is damped by the presence of antidots. In the case of thinner films and wider nanohole diameter a significant contribution from magnetization rotation mechanism is observed.
On coding effects in regularized categorical regression

This discussion is a continuation of Tutz and Gertheiss (2016)’s paper, where we focus on the importance of the coding of effects in regularized categorical and ordinal regression. We show that, though that an appropriate regularization is profitable for any coding, the choice of a relevant coding can prevail over the one of the regularization term for revealing structures. We focus on predictors though the issues raised also apply to responses. We illustrate our point on a classic data set.
A new species of Arrhenia (Agaricales, Hygrophoraceae) from Guizhou Province, China

: Arrhenia nivea is a new bryophilous species of Arrhenia from a valley in southwestern China’a subtropical monsoon humid climate zone.The species is characterized by pure white basidiomata with an irregularly discoid to cupulate 1.5–4.5 mm diameter pileus, reduced hymenium, nonamyloid basidiospores, lack of cystidia, the presence of clamps, and no incrusted pigment of the pileipellic hyphae. Phylogenetic analysis using ITS sequence data confirmed that it arised from a pathway separate from other species of Arrhenia .
Nonparametric Bayes Inference for Concordance in Bivariate Distributions

In this article the Bayesian approach to solving various inferential problems related to dependent bivariate distributions is explored by using Ferguson's theory of Dirichlet processes. Analogs of Kendall's τ and the concordance coefficient are defined in Section 2 to deal with discrete data. The Bayesian estimator under the squared error loss turns out to be a slightly modified version of Kendall's . The analysis is carried out to include the empirical Bayes approach in Section 3. In Section 4 a Bayesian test for testing positive dependence is derived. Some small sample comparisons are carried out in Section 5. Finally a numerical illustrative example is given in Section 6.
Stability Analysis of Magnetostatic Boundary Value Problems for Magnetic SMAs

Magnetic shape memory alloys have been the subject of much research in recent years as potential high actuation energy multifunctional materials. They can be considered as continua that deform under mechanical and magnetic forces. The constitutive magnetization response of such materials is highly non-linear with magnetic field. A boundary value problem where Maxwell’s equations of the magnetostatic problem are coupled with the non-linear constitutive behavior is solved using finite element analysis. The numerical simulation reveals localization zones of the field variables, which appear due to loss of ellipticity of the magnetostatic problem. Stability analysis is performed by considering the characteristics of the magnetostatic field equations.
CI Slide: calibration slide for quantitative microscopy imaging in absorbance

New imaging technologies are changing the field of digital pathology. This field faces numerous challenges and there is a pressing need for standardization, calibration protocols, quality control and quantitative assessment. We have designed a new calibration imaging slide (Cancer Imaging Slide), specifically to measure the characteristics of old or new imaging systems or scanners. The layout of the slide consists of 138 boxes with the side length of 1.6 mm, containing objects of known morphologic and photometric characteristics. Among them, 112 boxes contain different permutations of circles, ovals, and squares. The circles have different radii, radius/pitch ratios and step transmissions. The ovals have different sizes and orientations. The squares are consistent in size and orientation but have different step transmission values. Also, 16 boxes contain three resolution test targets: crosses, USAF target and Siemens star. The last 10 boxes are blank boxes with different transmission values. Four slides were scanned and imaged on one commercial whole-slide scanner and one high resolution imaging system. After segmenting the images, about 200 features (photometric, morphologic and architectural) were measured with our in-house image processing software. The objective of the project is to develop a statistical process control using this new slide. In this paper, we describe the characteristics of the slide and present our preliminary results.
Hole equilibria in Vlasov–Poisson systems: A challenge to wave theories of ideal plasmas

A unified description of weak hole equilibria in collisionless plasmas is given. Two approaches, relying on the potential method rather than on the Bernstein, Greene, Kruskal method and associated with electron and ion holes, respectively, are shown to be equivalent. A traveling wave solution is thereby uniquely characterized by the nonlinear dispersion relation and the “classical” potential V(φ), which determine the phase velocity and the spectral decomposition of the wave structure, respectively. A new energy expression for a hole carrying plasma is found. It is dominated by a trapped particle contribution occurring one order earlier in the expansion scheme than the leading term in conventional schemes based on a truncation of Vlasov’s equation. Linear wave theory— reconsidered by taking the infinitesimal amplitude limit—is found to be deficient, as well. Neither Landau nor van Kampen modes and their general superpositions can adequately describe these trapped particle modes due to an incorrect treatmen.
The associations of child screen time with psychiatric problems: the role of genetic confounding

Importance: Children exposure to screen time has been associated with poor mental health outcomes, yet the role of genetic factors in this association remains largely unknown. Objective: We examined (1) the longitudinal phenotypic association between child screen time and mental health outcomes and (2) the potential genetic confounding of this association. We hypothesized that genetics partially account for observed phenotypic associations. Design: Longitudinal (baseline and one-year follow-up) population-based cohort. Setting: Adolescent Brain Cognitive Development, 21 sites in the United States. Participants: This study included 4,262 children of genetically assigned European ancestry with mean age 9.9 years (SD = 0.6 years), 46.8% female. Exposure: Children daily screen time (in hours) was assessed both by child-report and parent-report questionnaires at baseline. Main Outcomes and Measures: Child psychiatric problems, specifically attention and internalizing problems, were measured with the parent-rated Child Behavior Checklist at the one-year follow-up. We used Genetic sensitivity analyses (Gsens), based on structural equation models using polygenic risk scores (PRS) of both exposure and outcomes, and either single nucleotide polymorphism (SNP)-based heritability or twin-based heritability to estimate genetic confounding of associations between child screen time and attention or internalizing problems, separately. Results: We found that child screen time was positively associated with the different psychiatric problems. Further, the television time PRS was associated with child screen time (beta=0.18 SD, 95% CI: 0.14, 0.23); the ADHD PRS was associated with attention problems (beta=0.13 SD, 95% CI: 0.10, 0.16); and the depression PRS was associated with internalizing problems (beta=0.10 SD, 95% CI: 0.07, 0.13). These PRSs were associated with cross-traits, suggesting genetic confounding. Using PRSs and SNP-based heritability, we estimated that genetic confounding entirely accounts for the association between child screen time and attention problems, and moderately (42.7%) accounts for the association between child screen time and internalizing problems. When PRSs and twin-based heritability estimates were used, genetic confounding fully explained both associations. Conclusions and Relevance: Genetic confounding may explain a substantial part of the associations between child screen time and psychiatric problems. Potential interventions to reduce screen time could be less effective in reducing psychiatric problems than previously hypothesized.
Production rate of transfer lines without buffer storage

Abstract We consider transfer lines without buffer storage in between the machines and with synchronous transfer. The processing time of each machine is a constant but machines are unreliable. Our analysis is based on the overall completion time of the transfer line, which is the time between successive transfers of parts within the line. Two techniques are presented. The first one provides lower and upper bounds on the production rate. These bounds can be made as tight as desired. The second technique provides an approximation of the production rate. It is based on the approximation of some distributions by simpler distributions having the same mean and coefficient of variation. We first consider the case of transfer lines with identical processing times and exponential times to failure and times to repair. Extensions to different processing times and general repair times are also discussed. Handled by the Department of Manufacturing and Automated Production.