Miracle-dz/UniFAR-FTUs huggingface dataset:
Initiation process and propagation mechanism of positive streamer discharge in water

The aim of this study was to clarify the initiation process and the propagation mechanism of positive underwater streamers under the application of pulsed voltage with a duration of 10 μs, focusing on two different theories of electrical discharges in liquids: the bubble theory and the direct ionization theory. The initiation process, which is the time lag from the beginning of voltage application to streamer inception, was found to be related to the bubble theory. In this process, Joule heating resulted in the formation of a bubble cluster at the tip of a needle electrode. Streamer inception was observed from the tip of a protrusion on the surface of this bubble cluster, which acted as a virtual sharp electrode to enhance the local electric field to a level greater than 10 MV/cm. Streak imaging of secondary streamer propagation showed that luminescence preceded gas channel generation, suggesting a mechanism of direct ionization in water. Streak imaging of primary streamer propagation revealed intermitten.
Time-resolved femtosecond optical characterization of multi-photon absorption in high-pressure-grown Al0.86Ga0.14N single crystals

We report our experimental studies on time-resolved pump–probe spectroscopy in high-quality Al0.86Ga0. 14N single crystals, grown using a solution technique in a high-nitrogen-gas-pressure system. Our optical measurements were performed using a non-traditional, two-beam [one ultraviolet (UV) and one infrared (IR)], femtosecond pump–probe approach, in which the photon energies of both beams were below the bandgap of the sample and each electron–hole pair was generated by a multi-photon process of absorption of a pump photon together with another photon produced by second harmonic generation from two probe photons. Temporal scanning of the probe while monitoring the normalized transient differential transmissivity (ΔT/T) signal, produced a 310-fs-wide, Gaussian-shaped correlation signal caused by the multi-photon absorption process, followed by a >100-ps-long relaxation of photo-excited carriers. By studying the ΔT/T correlation signal amplitude dependence on the pump-power intensity and wavelength, the mult.
Factors influencing illness uncertainty in parents of children with congenital adrenal hyperplasia in a developing country: A cross-sectional study

Background Illness uncertainty in parents of children with congenital adrenal hyperplasia (CAH) refers to parents’ inability to create meaning in events related to their children having CAH. This may influence their role in caring for children with CAH. Objective The study aimed to determine factors associated with illness uncertainty experienced by parents of children with CAH in a developing country. Methods A cross-sectional study was conducted on 80 parents (43 mothers and 37 fathers) of children with CAH, selected using consecutive sampling methods. The Parent’s Perception of Uncertainty Scale (PPUS) was used to measure the illness uncertainty levels. Data were collected from March 2020 to October 2020. Independent t-test and chi-square test were used to determine factors (parent’s gender, age, educational level, monthly household income, number of children with CAH, history of child death due to CAH, child’s age when first diagnosed with CAH, duration of therapy, gender change, type of CAH (salt wasting/SW or simple virilizing/SV), current gender, and genitoplasty) influencing illness uncertainty in parents. Results The mean scores of PPUS were 42.3 ± 12.91, and the majority of parents had a low PPUS score (49; 61%). Parents of children with SW-CAH showed higher uncertainty (44.2 ± 12.77) than those with SV-CAH (32.6 ± 8.86; p = 0.003). Parents who lost their children due to CAH were more likely to report a moderate illness uncertainty than parents who never experienced child mortality due to CAH (χ2(1, 80) = 4.893; p = 0.027). Conclusion The factors significantly affecting uncertainty in parents of children with CAH determined in this study might help healthcare professionals, including nurses, to play a pivotal role in giving pertinent information regarding their children’s health, disease, and therapy to help manage parental uncertainty.
Aspherical Coxeter Groups That are Quillen Groups

Let Γ be a group having finite virtual cohomological dimension. Let BΓ be its classifying space, and let C(Γ) be its Quillen category, whose objects are elementary abelian 2‐subgroups V of Γ and whose morphisms are restrictions of conjugacy of Γ. The group Γ is called a Quillen group if the natural map
Asymptotically Efficient Estimation of a Nonlinear Model of the Heteroscedasticity

Abstract The paper is devoted to the estimation of a nonlinear parametric model of the heteroscedasticity. The heteroscedasticity occurs in regression when the measurement noise variance is non-constant. Sometimes, the noise variance can be represented as a parameterized function of independent variables, so-called variance function. The maximum likelihood estimation (MLE) of variance function parameters leads to a system of nonlinear equations. The iterative solution of these nonlinear equations is based entirely on a successful choice of initial conditions. Hence, in the practice, the nonlinear MLE is intractable. To overcome this difficulty, another linear quasi-MLE estimator is proposed. It is strongly consistent, asymptotically Gaussian and only slightly less efficient than the Cramer-Rao lower bound. By using this estimator as an initial condition, an asymptotically efficient estimation is obtained by using one-step non-iterative Newton method. This approach has been applied to the GPS navigation in the constrained (urban) environment.
Adaptive nonlinear control of systems containing a deadzone

The authors present an adaptive nonlinear controller for a plant containing a nonsmooth nonlinearity with unknown parameters in the span of the control (specifically, a deadzone). They develop a Lyapunov-based adaptation scheme which updates the parameters of the specific region of the deadzone in which the system is operating. They then employ some switching logic to turn on and off the adaptation as the state of the system proceeds from one region of the deadzone to another. A significant feature of the adaptive controller is the presence of set uncertainty. Thus, conceptually, adaptation is not only for unknown parameters, but also for the regions of the piecewise smooth nonlinearity. <<ETX>>
Cross-Sectional Analysis of the Relationship Between Adherence to the Mediterranean Diet and Mental Wellness

The purpose of the study was to determine whether there was a relationship between adherence to the Mediterranean diet (MD) and levels of anxiety, depression, and overall mental well-being. The Mediterranean diet is a popular, healthy diet, aimed to promote wellness and reduce chronic illness. In order to determine the relationship between MD and mental well-being, 100 participants consented to complete an online survey to analyze their adherence to MD, along with levels of anxiety and depression. The validated questionnaires of the 14-item Questionnaire of Mediterranean diet Adherence, Generalized Anxiety Disorder-7 (GAD-7), and Beck's Depression Inventory (BDI) assessments were used to analyze each participant. To evaluate the results of the study, Spearman's rank correlation coefficient analysis was used to identify relationships between MD, depression, and anxiety. There was a significant negative correlation, indicating that MD adherence is associated with reduced depression and anxiety.
Increasing the reliability of ISOCAM ? cross-identifications by use of a probability pattern

The built-in play at the wheels of the ISOCAM instrument affects the accuracy of the astrometry of sources from the ISOCAM Parallel Catalogue. We present the results of different methods for cross-identifying ISOCAM sources with reference catalogues in the optical (USNO-A2.0) and in the near infrared (2MASS). For a sample of 7197 ISOCAM sources, the fraction having a real counterpart in the USNO and 2MASS catalogues was estimated to be 95% and 91% respectively. Using a nearest neighbor method for cross-identification, only 74% of the possible associations with USNO (79% with 2MASS) are retrieved. With the use of a so-called probability pattern to perform the associations, these values increase to 77% for USNO and 83% for 2MASS. In addition, the overall reliability of associations increases from 77 to 87% with USNO, and from 81 to 90% with 2MASS.
Some Phenomena of Sunspots and of Terrestrial Magnetism. Part II

1. In a previous paper, described here for brevity as S.M. , which referred to sunspots and terrestrial magnetism, I had occasion to enquire into the existence of any relation between the magnetic character of individual days and that of days separated from them by a given interval of time. References to previous work bearing on the subject will be found in S. M. , p. 97. The material of which I made principal use consisted of magnetic “character” figures—on the international scale 0 (quiet), 1 (moderately disturbed), and 2 (highly disturbed)—assigned by myself to all the days of the eleven years 1890 to 1900, from consideration of the Kew magnetic curves.
Filter design for directional multiresolution decomposition

In this paper we discuss recent developments on design tools and methods for multidimensional filter banks in the context of directional multiresolution representations. Due to the inherent non-separability of the filters and the lack of multi-dimensional factorization tools, one generally has to overcome factorization by indirect methods. One such method is the mapping technique. In the context of contourlets we review methods for designing filters with directional vanishing moments (DVM). The DVM property is crucial in guaranteeing the non-linear approximation efficacy of contourlets. Our approach allows for easy design of two-channel linear-phase filter banks with DVM of any order. Next we study the design via mapping of nonsubsampled filter banks. Our methodology allows for a fast implementation through ladder steps. The proposed design is then used to construct the nonsubsampled contourlet transform which is particularly efficiently in image denoising, as experiments in this paper show.
Collocation for two-point boundary value problems revisited

Collocation methods for two-point boundary value problems for higher order differential equations are considered. By using appropriate monomial bases, we relate these methods to corresponding one-step schemes for first order systems of differential equations. This allows us to present the theory for nonstiff problems in relatively simple terms, refining at the same time some convergence results and discussing stability. No restriction is placed on the meshes used.
Simultaneous estimation of ionospheric delays and receiver differential code bias by a single GPS station

In this paper, we propose an efficient Kalman filter algorithm for simultaneous estimation of absolute ionospheric delay and receiver differential code bias. It is well known that the two quantities are mixed in global positioning system (GPS) measurements causing a rank-deficiency problem. The proposed method requires only the broadcast navigation message and basic measurements provided by a single dual-frequency GPS receiver. Thus, it would be convenient to monitor local ionospheric activities autonomously in real time with minimum hardware. An observability analysis was performed in detail why the simultaneous estimation is possible in spite of the rank deficiency occurring in epoch-by-epoch measurements. Experimental results based on real GPS measurements demonstrate the feasibility of the proposed method.
Construction of a global Lyapunov function using radial basis functions with a single operator

We study the basin of attraction of an asymptotically stable equilibrium of a general autonomous ordinary differential equation. Sublevel sets of Lyapunov functions provide subsets of the basin of attraction. In this paper we construct a Lyapunov function by approximation via radial basis functions. We show the existence and the smoothness of a Lyapunov function with certain, given orbital derivative. By approximation of this Lyapunov function via its orbital derivative using radial basis functions we obtain a global Lyapunov function and can thus determine each compact subset of the basin of attraction.
A LIBRARY FOR DOING POLYHEDRAL OPERATIONS

Abstract The design and implementation of a library of C-code procedures to perform operations on rational polyhedra is described. The library supports intersection, union, difference, simplification in context, convex hull, affine image, affine preimage, and computation of dual forms. Since not all of these functions are closed over polyhedra, the library is extended to operate on finite unions of polyhedra. The major design decisions made during the implementation of the library are discussed. The data structure used for representing finite unions of polyhedra is developed and validity rules for the representation of polyhedra are derived. And finally, the algorithms used to implement the various functions in the library are presented.
An anisotropic hardening model for soils and its application to cyclic loading

An anisotropic hardening model for soils is proposed by applying the concept of a field of hardening moduli developed previously for metals. Besides the yield surface, a set of nesting surfaces in the stress-space specifies the variation of hardening moduli during the deformation process. Both drained and undrained soil behaviour can be treated and distortional as well as volumetric strain cycles can be considered. The model can be applied in studying soil behaviour under cyclic loading and in particular to describe densification or liquefaction phenomena.
Dichotomy theorem for general Minimum Cost Homomorphisms Problem

In the classical Constraint Satisfaction Problem(CSP) two finite models are given and we are asked to find their homomorphism. In the MinHom problem, besides the models, a set of weighted pairs of elements of this two models is given and the task is to find a homomorphism that maximizes the weight of pairs consistent with the homomorphism, i.e. pairs for which homomorphism maps the first element of the pair to the second element. MinHom can be considered as a generic model for a class of combinatorial optimization problems, one of which is a maximal independent set. It appears naturally in defence logistic and supervised learning. This problem shares a lot of common with the classical CSP. We show that it allows similar algebraic approach to the classification of tractable cases of this problem that connects it with relational and functional clones of multi-valued logic. Using this approach we obtain complete classification of polynomially tractable subcases of MinHom. As a result of this classification we confirm general dichotomy conjecture that was given for various special cases of MinHom in terms of digraph theory[12,11].
Environmental Effects on the Globular Cluster Blue Straggler Population: a Statistical Approach

Abstract Blue stragglers stars (BSS) constitute an ubiquitous population of objects whose origin involves both dynamical and stellar evolution. We took advantage of the homogeneous sample of 56 Galactic globular clusters observed with WFPC2/HST by Piotto et al. (2002) to investigate the environmental dependence of the BSS formation mechanisms. We explore possible monovariate relations between the frequency of BSS (divided in different subsamples according to their location with respect to the parent cluster core radius and half mass radius) and the main parameters of their host GC. We also performed a Principal Component Analysis to extract the main parent cluster parameters which characterise the BSS family.
The role of surface-induced ordering in the crystallisation of PET films

The molecular configuration and long-range order at the surface of spin-cast poly(ethylene terephthalate) (PET) thin films spin-cast onto an etched Si(001) surface during crystallisation from the amorphous state has been investigated for a range of annealing temperatures. The structural ordering at the surface of the film was compared directly with that in the bulk of the film by employing grazing-incidence X-ray diffraction with incident angles below, at and above the critical angle for total reflection. Ordering was observed at the surface at annealing temperatures of 80–95°C, lower than that in the bulk, involving local parallel alignment of chains in the plane of the surface with the benzene rings oriented preferentially with the ring plane parallel to the surface. Comparison with atomic-force microscopy images enables the fold configuration at the surface to be deduced.
Rotational and Vibrational Temperature Distributions for a Dielectric Barrier Discharge in Air

Spatially resolved rotational and vibrational temperatures for N 2 and rotational temperatures for N + 2 , as a function of voltage, have been obtained for an asymmetric surface mode dielectric barrier discharge using emission spectroscopy. The rotational temperatures were obtained from a nonlinear least-squares fit of a two-temperature theoretical spectrum with the measured spectra of the N 2 (C 3 Π u ― B 3 Π g ) and N + 2 (B 2 Σ + u ― X 2 Σ + g ) electronic band systems. The vibrational temperatures were obtained by applying the Boltzmann plot method to the Δv = ―2 sequence of the N 2 (C 3 Π u ― B 3 Π g ) electronic band system. It was observed that the rotational temperatures for N 2 ? and N + 2 decreased in the induced flow direction and increased with increasing voltage. Values started at 390 ± 10 K and decreased to 340 ± 10 K for N 2 and started at 500 ± 15 K and decreased to 450 ± 15 K for N + 2 . The vibrational temperatures also decreased in the induced flow direction from 3250 to 2850 ± 300 K. A difference in rotational temperatures between N 2 and N + 2 was observed for all voltages studied, and these differences increased with increasing voltage. The rotational temperatures of both species fluctuated in the spanwise direction. These fluctuations damped out in the streamwise direction and were weakly correlated with the attachment points of the microdischarges on the edge of the exposed electrode.
VIMOS and NIRMOS multi-object spectrographs for the ESO VLT

The VIRMOS consortium of French and Italian Institutes is manufacturing 2 wide field imaging multi-object spectrographs for the European Southern Observatory Very Large Telescope, with emphasis on the ability to carry over spectroscopic surveys of large numbers of sources. The Visible Multi-Object Spectrograph, VIMOS, is covering the 0.37 to 1 micron wavelength domain, with a full field of view of 4 by 7 by 8 arcmin2 in imaging and MOS mode. The Near IR Multi-Object Spectrograph, NIRMOS, is covering the 0.9 to 1.8 microns wavelength range, with afield of view 4 by 6 by 8 arcmin2 in MOS mode. The spectral resolution for both instrument scan reach up to R equals 5000 for a 0.5 arcsec wide slit. Multi-slit masks are produced by a dedicated Mask Manufacturing Machine cutting through thin Invar sheets and capable of producing 4 slit masks approximately 300 by 300 mm each with approximately slits 5.7 mm long in less than one hour. Integral field spectroscopy is made possible in VIMOS by switching in the beam specially build masks fed by 6400 fibers coming form a 54 by 54 arcsec2 integral field head with a 80 by 80 array of silica micro-lenses. NIRMOS has a similar IFS unit with a field of 30 by 30 arcmin2. These instruments are designed to offer very large multiplexing capabilities. In MOS mode, about 1000 objects can be observed simultaneously with VIMOS, with a S/N equals 10 obtained on galaxies with I equals 24 in one hour, and approximately 200 objects can be observed simultaneously with NIRMOS, with a S/N equals 10 obtained don galaxies with J equals 22, H equals 20.6 in 1h at Req equals 200. We present here the status of VIMOS, currently under final integration, with expected first light in the summer 2000, together with the final design of NIRMOS presented at the Final Design Review. The VLT-VIRMOS deep redshift survey of more with the final design of NIRMOS presented at the Final Design Review. The VLT-VIRMOS deep redshift survey of more than 150000 galaxies over the redshift range 0 < z < 5 will be undertaken based on 120 guaranteed nights awarded to the project.
Zernike coefficients for concentric, circular scaled pupils: an equivalent expression

We present an alternative formal calculation of the scaled Zernike coefficient expansion by means of the inner product of the Zernike polynomials and the wavefront error corresponding to the scaled pupil. The relationship exhibited by the radial polynomials and Bessel functions leads to a general expression in terms of the Gauss hypergeometric function. Direct properties and index selection rules are established, and easy derivation of the non-normalized coefficients is also straightforward.
Parsimonious and robust realizations of unitary maps in the one-way model

We present a new set of generators for unitary maps over n C 2 which differs from the traditional rotation-based generating set in that it uses a single-parameter family of 1-qubit unitaries J(�), together with a single 2-qubit unitary, ^Z. Each generator is implementable in the one-way model [1] using only two qubits, and this leads to both parsimonious and robust implementations of general unitaries. As an illustration, we give an implementation of the controlled-U family which uses only 14 qubits, and has a 2-colourable underlying entanglement graph (known to yield robust entangled states).
On the likelihood estimation of the parameters of Gompertz distribution based on complete and progressively Type-II censored samples

In this paper, by considering a progressively Type-II censored sample from the two-parameter Gompertz distribution, a necessary and sufficient condition is established for the existence and uniqueness of the maximum-likelihood estimates of the shape and scale parameters. The results for the special cases of complete and ordinary Type-II right censored samples are then deduced. Several numerical examples from the literature are presented for the purpose of illustrating the established results.
Optical limiter using a lead phthalocyanine

The performance of an optical limiter based on Pb‐tetrakis(cumylphenoxy)phthalocyanine, a robust organic material with a large χ(3) and figure of merit, χ(3)/α0, is described. In an f/5 limiter with a sample transmission of 0.68, the threshold for limiting was 8±2 nJ and the dynamic range was greater than a factor of 103. The threshold for the PbPc(CP)4 limiter was ∼15 times smaller and the high intensity transmission ∼4–5 times lower than an equivalent limiter based on a thermal nonlinearity.
OPLS discriminant analysis: combining the strengths of PLS‐DA and SIMCA classification

The characteristics of the OPLS method have been investigated for the purpose of discriminant analysis (OPLS‐DA). We demonstrate how class‐orthogonal variation can be exploited to augment classification performance in cases where the individual classes exhibit divergence in within‐class variation, in analogy with soft independent modelling of class analogy (SIMCA) classification. The prediction results will be largely equivalent to traditional supervised classification using PLS‐DA if no such variation is present in the classes. A discriminatory strategy is thus outlined, combining the strengths of PLS‐DA and SIMCA classification within the framework of the OPLS‐DA method. Furthermore, resampling methods have been employed to generate distributions of predicted classification results and subsequently assess classification belief. This enables utilisation of the class‐orthogonal variation in a proper statistical context. The proposed decision rule is compared to common decision rules and is shown to produce comparable or less class‐biased classification results. Copyright © 2007 John Wiley & Sons, Ltd.