Miracle-dz/UniFAR-FTUs huggingface dataset:
On the Information Matrix of Exponential Mixture Models with Long‐term Survivors

The aim of this paper is to study the properties of the asymptotic variances of the maximum likelihood estimators of the parameters of the exponential mixture model with long-term survivors for randomly censored data. In addition, we study the asymptotic relative efficiency of these estimators versus those which would be obtained with complete follow-up. It is shown that fixed censoring at time T produces higher precision as well as higher asymptotic relative efficiency than those obtainable under uniform and uniform-exponential censoring distributions over (0, T). The results are useful in planning the size and duration of survival experiments with long-term survivors under random censoring schemes.
Anxiety Levels of the Patients and Their Relatives During Their Visit of Health Institutions in COVID-19 Pandemic

OBJECTIVEIn our study, it was aimed to compare the anxiety;state and trait anxiety states among the communities who went to health institutions for different purposes during the COVID-19 epidemic and to evaluate the factors affecting anxiety, state and trait anxiety. METHODSThe data of this study were collected face to face using the Beck Anxiety Inventory (BAI), State Anxiety Inventory (STAI-S) and Trait Anxiety Inventory (STAI-T) for cancer patients who applied to the Oncol-ogy center between October 2020 and December 2020. Their companions and the patients who went to a primary healthcare institution. Participants' awareness of the COVID pandemic and the effects of the pandemic on their lives and demographic information were also recorded. A total of 252 participants responded to the tests.RESULTSIn our study, 252 people, including 130 (51.6%) cancer patients, 49 (19.4%) cancer patient companions, and 73 outpatients who applied to a primary healthcare institution, participated in our study. In all participants, the mean anxiety level according to BAI was 10.75 +/- 12.5 (0-48), the mean state anxiety according to STAI-S was 44.42 +/- 10.59 (20-74), according to STAI-T, the mean trait anxiety was found to be 45.65 +/- 8.80 (20-78) points. Among the three groups, the highest anxiety, state and trait anxiety was seen in patients who applied to primary healthcare institution.CONCLUSIONIn our study, many factors affecting the anxiety and anxiety levels of the patients and their relatives who applied to health institutions for different reasons, also under the influence of the pandemic, were determined. With such studies, the psychosocial conditions of the patients and their relatives should be closely followed in the event of the future epidemics, and psychological treatments and support needs should be kept in mind in addition to the primary treatment of their diseases.
Kinetic simulations of electron response to shear Alfvén waves in magnetospheric plasmas

Standing and traveling shear Alfven waves contribute to electron acceleration and parallel electric field formation on auroral field lines in the Earth’s magnetosphere. In this paper, the self-consistent coupled Vlasov–Maxwell system for shear Alfven waves is solved in one dimension. The Vlasov equation is gyro-averaged in order to minimize the number of dimensions in the problem, and to avoid numerical problems with the direct evaluation of the parallel electric field, the electron distribution function is described in terms of a spatial coordinate along the field line, the magnetic moment, and the canonical parallel momentum per unit mass. Some preliminary studies of shear Alfven wave pulses propagating in a uniform magnetic field on model auroral field lines are presented with an emphasis on the kinetic electron response and the parallel electric field. It is shown that when the full parallel electron dynamics are included, wave–particle interactions result in intensification of the parallel electric field and significant heating of the electrons. It is also demonstrated the acceleration of electrons to speeds of the order of twice the wave phase speed, which has been shown by previous calculations. The results are compared with recent observations made by both the NASA Fast Auroral Snapshot and the Freja satellites.Standing and traveling shear Alfven waves contribute to electron acceleration and parallel electric field formation on auroral field lines in the Earth’s magnetosphere. In this paper, the self-consistent coupled Vlasov–Maxwell system for shear Alfven waves is solved in one dimension. The Vlasov equation is gyro-averaged in order to minimize the number of dimensions in the problem, and to avoid numerical problems with the direct evaluation of the parallel electric field, the electron distribution function is described in terms of a spatial coordinate along the field line, the magnetic moment, and the canonical parallel momentum per unit mass. Some preliminary studies of shear Alfven wave pulses propagating in a uniform magnetic field on model auroral field lines are presented with an emphasis on the kinetic electron response and the parallel electric field. It is shown that when the full parallel electron dynamics are included, wave–particle interactions result in intensification of the parallel electric f.
Shape coexistence in doubly-magic 56 Ni by the Monte Carlo shell model

The structure of low-lying states of ${}^{56}\mathrm{Ni}$ is studied by the Monte Carlo shell model based on the quantum Monte Carlo diagonalization method. The coexistence of spherical yrast, prolate deformed, and other non-yrast states is described by the full $\mathrm{pf}$-shell calculations, by employing the FPD6 realistic residual interaction. To understand the properties of eigenstates thus obtained, we utilize a mean field analysis, such as a potential energy surface by constrained Hartree-Fock method.
A retrospective analysis of blood culture-negative endocarditis at a tertiary care centre in Switzerland.

AIMS OF THE STUDY Numerous studies from different countries have contributed to an improved understanding of blood culture-negative infective endocarditis. However, little is known about its epidemiology and microbiology in Switzerland. We aimed to assess the epidemiology and microbiology of blood culture-negative endocarditis at the University Hospital Zurich, Switzerland. METHODS We screened all patients hospitalised between 1997 and 2020 with possible or definite endocarditis at our institution. Thereof, we identified all cases with blood culture-negative endocarditis and retrospectively retrieved patient characteristics, microbiological, histopathological, radiographic and surgical data from medical records. RESULTS Among 861 patients screened, 66 (7.7%) cases of blood culture-negative endocarditis were identified. Thereof, 31 cases could be microbiologically documented or not documented (n = 30), and in five cases a non-infectious aetiology was confirmed. Endocarditis predominantly affected men (77%) and the left heart (79%); predisposing factors were prosthetic valves (42%), congenital heart disease (35%) and prior endocarditis (14%). The most common reasons for negative blood cultures were antibiotic treatment prior to blood culture sampling (35%), fastidious and slow growing microorganisms (30%) and definite non-infective endocarditis (8%). Coxiella burnetii and Bartonella spp. were the most common fastidious bacteria identified. In addition to serology, identification of causative microorganisms was possible by microbiological and/or histopathological analysis of tissue samples, of which polymerase chain reaction testing (PCR) of the 16S ribosomal RNA proved to be most successful. CONCLUSIONS The present study provides a detailed analysis of blood culture-negative endocarditis over a time span of more than 20 years in Zurich, Switzerland. Antibiotic treatment prior to blood collection, and fastidious and slow growing organisms were identified as main reasons for sterile blood cultures. Typical culture-negative bacteria were mainly found by PCR and/or culture of tissue samples.
The stretching of a slender, axisymmetric, viscous inclusion—Part I: asymptotic analysis

A slender, axisymmetric inclusion of a highly viscous fluid is deformed by an external Stokes flow. The method of matched asymptotic expansions is used, and boundary conditions for the outer flow are found in terms of the cross-sectional area of the inclusion and its local extensional velocity along the axis. This problem is then formulated as an integral equation for which an exact solution is found.
Effect of electron density profile on power absorption of high frequency electromagnetic waves in plasma

Considering different typical electron density profiles, a multi slab approximation model is built up to study the power absorption of broadband (0.75-30 GHz) electromagnetic waves in a partially ionized nonuniform magnetized plasma layer. Based on the model, the power absorption spectra for six cases are numerically calculated and analyzed. It is shown that the absorption strongly depends on the electron density fluctuant profile, the background electron number density, and the collision frequency. A potential optimum profile is also analyzed and studied with some particular parameters.
Rate of convergence for the generalized Pareto approximation of the excesses

Let F be a distribution function in the domain of attraction of an extreme-value distribution H γ. If F u is the distribution function of the excesses over u and G γ the distribution function of the generalized Pareto distribution, then it is well known that F u (x) converges to G γ(x/σ(u)) as u tends to the end point of F, where σ is an appropriate normalizing function. We study the rate of (uniform) convergence to 0 of F̅ u (x)-G̅γ((x+u-α(u))/σ(u)), where α and σ are two appropriate normalizing functions.
SPRT's for the Normal Correlation Coefficient

Abstract Hypothesis tests for the correlation coefficient of a bivariate normal distribution are investigated. Some tests using reductions of the data that are not invariantly sufficient were proposed by Kowalski on the grounds that the mathematical properties may be worked out, which is not possible when using sequential probability ratio tests (SPRT's) based on successive invariantly sufficient statistics. These latter tests may be derived from Cox's theorem or from maximal invariance theory. We show how inefficient Kowalski's tests are and, thus motivated, we derive approximations for the mathematical properties of Cox's test with equal variances.
Spectrum restoration for uniformly spaced arrays

An ambient narrow‐frequency‐band acoustic field is described by the power density function N (cos ϑ), with ϑ the bearing angle from a line array of sensors. This field is observed through a conventional delay‐and‐sum beamformer, with average power output B (cos φ) when steered to bearing φ. We present a method (spectrum restoration) for obtaining the (wavenumber) bandlimited version of N from observed values of B. We consider only uniformly spaced arrays, and treat two computationally distinct situations: Δ < λ/2 and Δ ? λ/2, where λ is the wavelength of the narrow‐band field incident on the array and Δ is the array element spacing. In the former case, our method is only approximate; however, it can be carried through computationally, in contrast with methods proposed earlier, which in general succeed only for the case Δ ? λ/2. Computational results are presented for a variety of simulated noise fields, indicating sharper resolution and decreased side‐lobe levels in the obtained field restoration, as comp.
State-Space Stabilizing Controllers for Descriptor Systems

This paper considers stabilization of linear time-invariant descriptor systems by dynamic output feedback controllers. We deal with general descriptor systems including those being irregular or impulsive, and derive statespace stabilizing controllers. On the derivation process of the state-space controllers, we first consider descriptor-type controllers. We present a necessary and sufficient condition for the existence of a descriptor-type controller which makes the closed-loop descriptor system regular, impulse-free, and stable. The condition is expressed in terms of linear matrix inequalities (LMIs), and we show that coefficient matrices of any descriptor-type stabilizing controller of the same size as the given descriptor system can be represented by the solution of the LMIs. Then, we present a necessary and sufficient condition for the descriptor-type controller to be transformable to an input-output equivalent state-space controller with the dimension of the dynamic order (the rank of the coefficient matrix for the time-derivative of the descriptor variable) of the given descriptor system, that is, a state-space stabilizing controller. The transformability condition is mild and almost always satisfied by the obtained descriptor-type controller. Furthermore, even if the transformability condition is not satisfied, a slightly modified solution of the LMIs, which always exists, gives a descriptor-type controller being transformable to a state-space controller. The transformation is carried out analytically, thus the coefficient matrices of any such state-space stabilizing controller can be expressed by the solution of the LMIs. We also reveal that if we restrict the classes of descriptor systems or descriptor-type controllers such that their transfer functions are strictly proper, the descriptor-type controllers obtained by the LMI condition are always transformable to state-space controllers.
Far-field vectorial structure of a higher-order cosh-Gaussian beam

Based on the vector angular spectrum representation and the method of stationary phase, the vectorial structural characteristics of a higher-order cosh-Gaussian (HOCG) beam in the far field are investigated. Analytical expressions for the energy flux distributions of the TE term, TM term and the whole beam are derived and illustrated by numerical examples. Influences of beam orders and cosh parameters on energy flux distributions are analyzed, respectively. Furthermore, the discrepancy for the total energy flux distributions between the non-paraxial and paraxial cases is presented and analytical explanations for the phenomenon are also given.
Applicational aspects of support vector machines

The special emphasis of support vector machines (SVMs) on generalization ability makes this approach particularly interesting for real‐world applications with limited amounts of training data. In this paper we analyse the applicational aspects of SVMs, illustrating them with the step‐by‐step construction of a classifier for polymers by means of their mid‐infrared spectra. With this example we show how the main difficulties of a typical industrial classification task can be addressed using SVMs. Copyright © 2002 John Wiley & Sons, Ltd.
Multivariate binary discrimination by the kernel method

SUMMARY An extension of the kernel method of density estimation from continuous to multivariate binary spaces is described. Its simple nonparametric nature together with its consistency properties make it an attractive tool in discrimination problems, with some advantages over already proposed parametric counterparts. The method is illustrated by an application to a particular medical diagnostic problem. Simple extensions of the method to categorical data and to data of mixed binary and continuous form are indicated.
The Relationship between Heel Fat Pad Thickness and Flexibility and Physical Demographics

To clarify the factors that contribute to the development of heel pain in young individuals, this study investigated the relationship of heel thickness and flexibility with physical demographics among Japanese elementary and junior high school students. A total of 69 heels were included as participants in this study. The measurement items were age, height, weight, rohrer index, heel fat pad thickness and flexibility. The heel fat pad thickness and flexibility was measured using an ultrasound probe and S oftgram (Shinko Denshi co.,ltd.). The heel fat pad thickness measurements were distance from the skin to the calcaneus was measured by applying the ultrasound probe both without (hereafter referred to as "non-pressure thickness") and with manually applied pressure to the measurement point (hereafter referred to as “pressure thickness”) . The heel fat pad flexibility evaluation consisted of subtracting non-pressure thickness by pressure thickness (thickness of change difference), and computing for the value when the thickness of change difference is divided by the non-pressure thickness and multiplied by 100 (thickness of change rate). In addition to this, heel fat pad flexibility evaluation consisted of measuring using the softness sensor Softgram. Multiple regression analysis showed that weight and age were predictors of non-pressure thickness. On the other hand, pressure thickness was weight was a predictor of pressure thickness. In the relationship between heel fat pad flexibility and demographic data, the Softgram measurements showed a significantly fair correlation with age and significantly moderate correlations with height and weight. Multiple regression analysis further showed that body weight was a predictor of Softgram measurements. This results suggest that heel fat pad thickness and flexibility in elementary and junior high school students became thicker and stiffer, respectively, with increasing age, height and weight. Notably, both thickness and flexibility were particularly related to body weight.
Asymmetric transport and non-Gaussian statistics of passive scalars in vortices in shear

Transport of passive scalars in a chain of vortices in a shear layer is studied using a model motivated by the quasigeostrophic equation, and a discrete map model. Surrounding the vortices there is a stochastic layer where particles alternate chaotically between being trapped in the vortices, and moving following the shear flow. Transport in the stochastic layer is asymmetric: Mixing between the vortices and the up-stream flow is, in general, different from mixing between the vortices and the down-stream flow. We use the Melnikov method to study this asymmetry, and to construct a generalized separatrix map model for asymmetric transport. The statistics of the passive scalar is non-Gaussian. In particular, there is anomalous advection, and anomalous (non-Brownian) diffusion. Thus, transport in this system cannot be described by an advection-diffusion equation with an effective diffusivity. The probability density function (PDF) of particle displacements δx, P(δx,t), is asymmetric and broader than Gaussian.
Initiation of coalescence in a cumulus cloud: A beneficial influence of entrainment and mixing

Abstract. Although rain has been observed to form in warm cumulus clouds within about twenty minutes, calculations that represent condensation and coalescence accurately in such clouds have had difficulty producing rainfall in such a short time except via processes involving giant cloud condensation nuclei (with diameters larger than 2 μm). This model-based study explores a different possible mechanism for accelerating the production of warm rain, one that depends on the variability in droplet trajectories arriving at a given location and time in a cumulus cloud. In the presence of entrainment such droplets experience different growth histories, and the result is broadening of the droplet size distribution. That broadening favours coalescence, leading to embryos that grow to raindrops. These calculations do lead to production of rain that is within the lower range of observations for clouds of Florida, USA, the location on which the input conditions were based. The process emphasized in this study, the formation of drizzle via collisions among droplets in the main peak of the droplet size distribution, complements the growth of precipitation on giant nuclei, which is also an important source of the first rain in the case studied. The results indicate that the mechanism developed here should be considered an important influence on the formation of rain in warm clouds.
Single-RF MIMO-OFDM Using ESPAR

A novel beamspace multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) transmission system using a single-radio-frequency (RF) electronically steerable parasitic array radiator (ESPAR) is described. It makes use of recent results for decomposing the patterns of any arbitrary ESPAR onto an orthogonal basis set using the Theory of Characteristic Modes (TCM). Leveraging this decomposition, OFDM symbols can be mapped into the beamspace domain so that the ESPAR can be used to transmit multiple streams of OFDM symbols using a single RF chain. In the proposed approach, we use the Linde-Buzo-Gray (LBG) algorithm to quantize the OFDM symbol vectors and form a codebook. A binary search tree is then utilized to efficiently find the reactive loads of ESPAR to excite the radiation patterns corresponding to the quantized symbols. It is shown by simulation that quantized codewords and the corresponding radiation patterns can be excited using ESPAR. In addition, the simulated bit error rate (BER) results of the proposed approach are shown to be close to that of conventional MIMO-OFDM systems, demonstrating the effectiveness of implementing a single-RF MIMO-OFDM transmitter.
Reformulation of the lamellar grating problem through the concept of adaptive spatial resolution

The lamellar grating problem is reformulated through the concept of adaptive spatial resolution. We introduce a new coordinate system such that spatial resolution is increased around the discontinuities of the permittivity function. We derive a new eigenproblem that we solve by using Fourier expansions for both the field and the coefficients of Maxwell’s equations. We provide numerical evidence that highly improved convergence rates can be obtained.
Predicting customer loyalty to Airbnb using PLS-SEM: the role of authenticity, interactivity, involvement and customer engagement

PurposeDrawing on social exchange theory, this study clarifies the roles of authenticity, interactivity and involvement in predicting customer engagement (CE) and, ultimately, customer loyalty towards an online peer-to-peer accommodation platform. In addition, the study explores the effect of interactivity in increasing authenticity.Design/methodology/approachData were collected through an online questionnaire of a sample of Italian tourists who had previously booked a service on Airbnb. The analyses were conducted by adopting partial least squares structural equation modelling.FindingsThe model has high power in predicting customer loyalty to an online peer-to-peer accommodation platform. Specifically, involvement is the primary predictor of CE and customer loyalty. Authenticity and interactivity also have a significant and positive effect both on CE and customer loyalty. In addition, CE partially mediates the relationship between authenticity, interactivity and involvement and customer loyalty. Finally, interactivity has a significant positive effect on authenticity.Practical implicationsThe results encourage hospitality service providers to invest in the creation (and co-creation) of authentic experiences to increase CE and customer loyalty. Hospitality managers can also enhance CE by increasing involvement and interaction with customers through various touchpoints (online and offline) in different moments of the customer journey.Originality/valueThis study proposes an original model to predict customer loyalty to peer-to-peer hospitality platforms. The findings shed new light on the drivers of CE and provide empirical support for the mediating effect of CE. The study also contributes to the literature on authenticity by demonstrating the positive effect of interactivity on authenticity.