Miracle-dz/UniFAR-FTUs huggingface dataset:
Semiparametric analysis of transformation models with doubly censored data

Double censoring arises when T represents an outcome variable that can only be accurately measured within a certain range, [L, U], where L and U are the left- and right-censoring variables, respectively. In this note, using Martingale arguments of Chen et al. [3], we propose an estimator (denoted by ˜β) for estimating regression coefficients of transformation model when L is always observed. Under Cox proportional hazards model, the proposed estimator is equivalent to the partial likelihood estimator for left-truncated and right-censored data if the left-censoring variables L were regarded as left-truncated variables. In this case, the estimator ˜β can be obtained by the standard software. A simulation study is conducted to investigate the performance of ˜β. For the purpose of comparison, the simulation study also includes the estimator proposed by Cai and Cheng [2] for the case when L and U are always observed.
Improved Dual Band-Notched UWB Slot Antenna with Controllable Notched Bandwidths

A compact dual band-notched ultra-wideband slot antenna with sharp band-notched characteristics and controllable notched bandwidths is presented. The antenna is formed by a rectangular slot with chamfered corners on a printed circuit board ground plane, a T-shaped stub and two sets of compound band- notched structures. The compound band-notched structures are employed to generate desired lower and upper rejected bands with satisfactory skirt characteristics and su-cient rejection bandwidths. Moreover, the bandwidth of either the lower or upper rejected band can be independently adjusted by changing the size and location of the corresponding band-notched structure. Finally, a UWB slot antenna with two rejected bands at WiMAX/WLAN frequencies is successfully simulated, designed, and measured, showing good impedance matching, stable gain and near omnidirectional radiation patterns.
“Periodicity” Pitch and “Place” Pitch

In the year of the founding of the Acoustical Society of America, Wever and Bray observed periodic “volleys” of impulses in the auditory nerve. Since that time, the theory of pitch perception—particularly, whether pitch depends upon the frequency of the discharges or upon the locus of the active neural tissue—has been one of the most active issues in physiological and psychological acoustics. The most recently reported observations, those of Hoogland, 1953, support the place theory and the conclusion that “Schouten's residue theory [a form of the volley theory] seems to be improbable. ” The present paper contains a demonstration to the contrary, that one can, in fact, hear low pitch with the high‐frequency channels of the auditory system—with the part of the system that, according to place theory, should give rise to high pitch. This demonstration is one of Schouten's, but with the low‐frequency auditory channels saturated with low‐frequency masking noise. The pitch that is heard is correlated with volley .
Breaking Rossby Waves in a Model Stratosphere Diagnosed by a Vortex-Following Coordinate System and a Technique for Advecting Material Contours

Abstract This paper presents results from a single-layer, shallow-water, 100-day model integration that reproduces many features of the wintertime stratosphere, particularly in the tropics, more realistically than earlier single-layer integrations. The advective transport of passive tracers by breaking Rossby waves is examined using a new polar-vortex-following coordinate system and a technique for advecting material contours, in which they are followed very accurately using the contour-dynamics algorithm of Dritschel. Unlike any Eulerian tracer advection scheme, the technique for advecting material contours has no numerical diffusion and can handle the ultrafinescale, exponentially shrinking tracer features characteristic of chaotic advective transport or “stirring,” which is conspicuous here in the stratospheric “surfzone. ” The technique may become important as a benchmark for quantitative comparison with Eulerian tracer advection schemes, such as those used in general circulation models. Averages with .
Semianalytical Solution for Three-Dimensional Vibration Analysis of Thick Multidirectional Functionally Graded Annular Sector Plates under Various Boundary Conditions

AbstractThe free vibration of two-dimensional (2D) functionally graded annular sector plates is analyzed based on the three-dimensional (3D) theory of elasticity, using the 2D differential quadrature method. The plates with simply supported radial edges and arbitrary boundary conditions on their circular edges are considered. This paper presents a novel 2D power-law distribution for ceramic volume fraction of 2D functionally graded material that gives designers a powerful tool for flexible designing of structures under multifunctional requirements. Various material profiles along the thickness and radial direction are illustrated using the 2D power-law distribution. The effective material properties at a point are determined in terms of the local volume fractions and the material properties by the Mori-Tanaka scheme. A semianalytical approach composed of the differential quadrature method and series solution is adopted to solve the equations of motion. The fast rate of convergence and accuracy of the meth.
High-performance quantum cascade lasers in the 7.3- to 7.8-μm wavelength band using strained active regions

We consider the use of strained quantum cascade (QC) laser designs in the 7.3- to 7.8-µm wavelength region to improve the cw operating characteristics of these lasers at room temperature. We compare the performance of a QC laser with a strain-balanced active region with that of two similarly designed QC lasers with lattice-matched active-region layers, and we show that the strain-balanced design significantly outperforms the unstrained-layer designs in terms of threshold-current density, power slope efficiency, and cw output power at room temperature. A epi-side-down-mounted, double-channel ridge-geometry laser that was fabricated from the strained design with a ridge width of 13 µm and a cavity length of 3 mm produced cw output power in excess of 500 mW at room temperature. The characteristic temperature T0 for the strained-layer design as determined from pulsed measurements between 25 and 80°C is 221.5 K, compared with a value of 194.0 K for one of the unstrained designs.
A Graphical Exposition of the Ordered Probit

The use of probit and logit models has become quite common whenever the dependent variable in a regression is qualitative. These models have been used to explain either/or choices and decisions involving multiple alternatives. A two-dimensional graphical interpretation of these different models has been provided by Johnson [3]. The purpose of this paper is to provide a three-dimensional graphical exposition of the ordered probit model, which was first estimated by McKelvey and Zavoina [4] and is now built into computer packages, such as LIMDEP [1].
Asymptotic efficiency of model selection criteria: the nonzero mean Gaussian AR(∞) case

Motivated by Shibata’s (1980) asymptotic efficiency results this paper dis-cusses the asymptotic efficiency of the order selected by a selection procedure for an infinite order autoregressive process with nonzero mean and unob servable errors that constitute a sequence of independent Gaussian random variables with mean zero and variance σ2 The asymptotic efficiency is established for AIC–type selection criteria such as AIC’, FPE, and Sn(k). In addition, some asymptotic results about the estimators of the parameters of the process and the error–sequence are presented.
Semi-idempotent measures on abelian groups

Let M (G) denote the set of complex valued regular Borel measures on a compact abelian group G. We assume that T, the dual group of G, is a totally ordered group. Let F(G) denote the set of all /z£ itf(G) such tha t the Fourier transform fi of /x is an integer valued function. A measure fx is idempotent if fi assumes only the values 0 or 1. A liC:M{G) is semi-idempotent if fi(y) = 0 or 1 for all 7 > 0 in T. The purpose of this note is to sketch a proof of the following theorem.
The Impact of Misspecified Item Parceling on Representing Latent Variables in Covariance Structure Modeling: A Simulation Study

This study focused on misspecifications in composing parcels to represent a latent construct. Two measurement design factors, item reliability and intercorrelations among parcels, defined 12 true unidimensional parcel models. Deviations from the true model were examined via a 2-facet measurement model in which items and parcels represented the 2 facets. Unidimensionality was examined using a set of criteria developed for the 2-facet measurement model. Many misspecified parcel models produced admissible factor loadings despite poor overall fit and unacceptable residual covariances. The factor loadings alone may not be sufficient for evaluating latent factor representation. The findings suggest that parcels' unidimensionality should be analyzed before the measurement model to which they belong is entered into a comprehensive structural model. The 2-facet measurement model provides a relevant assessment of unidimensionality of the parcel compositions.
Quasiregular mapping by branched circle packing

We use branched circle packings to construct an approximating sequence to a proper quasiregular mapping, that is a general proper solution of a Beltrami equation. We show that the approximating sequence converges on compact subsets, and show that for given branch-set the solution is unique subject to a certain normalization.
Dual Orthogonal Matrices in Manipulator Kinematics

The angular or linear displacements required at each of the joints of a robot manipulator to attain a specified position and orientation of its hand are obtained by solving the closure equations of the manipulator. These equations express the fact that the sequence of coordinate transformations between each link of the manipulator from its hand to its base must equal the transformation from the hand to the base directly. It is well known that the 4 X 4 homogeneous form of the point coordinate transformation matrix together with special coor dinate frames adapted to the structure of a manipulator yield a standard form of these coordinate transformation matrices known as the Denavit-Hartenberg matrix (Paul 1981). It is not so well known that the transformation equations of the coordinates of lines in these special coordinate frames may be used as well (Pennock and Yang 1985). Furthermore, by introducing dual numbers, the 6 X 6 matrices that arise col lapse into 3 X 3 orthogonal matrices with dual number ele ments, yielding a dual form of the Denavit-Hartenberg ma trix. Presented here is an elementary development of these results. Also discussed is a dual form of the Jacobian of a manipulator.
Recovering the ages and metallicities of stars of a complex stellar population system

Abstract We present a new method to solve for the star-formation history (SFH) of a complex stellar population system from the analysis of the color-magnitude diagram (CMD). The SFH is obtained in four steps: i) computing a synthetic CMD, ii) simulating observational effects, iii) parameterization and sampling of the synthetic and observed CMDs, and iv) solving and averaging the solutions. The consistency and stability of the method have been tested using a mock stellar population. The method has been used to solve the SFH of a set of six isolated Local Group dwarf galaxies observed with HST. The main goal is to probe the effects of cosmological processes, such as reionization in the early star formation, or the ability of SNe feedback to remove gas in small halos, in dwarf galaxies free from environmental effects due to the strong interaction with the host galaxy.
Existence and uniqueness of solutions to weakly singular integral-algebraic and integro-differential equations

We consider systems of integral-algebraic and integro-differential equations with weakly singular kernels. Although these problem classes are not in the focus of the main stream literature, they are interesting, not only in their own right, but also because they may arise from the analysis of certain classes of differential-algebraic systems of partial differential equations. In the first part of the paper, we deal with two-dimensional integral-algebraic equations. Next, we analyze Volterra integral equations of the first kind in which the determinant of the kernel matrix k(t, x) vanishes when t = x. Finally, the third part of the work is devoted to the analysis of degenerate integro-differential systems. The aim of the paper is to specify conditions which are sufficient for the existence of a unique continuous solution to the above problems. Theoretical findings are illustrated by a number of examples.
Exact optics - II. Exploration of designs on- and off-axis

The two-mirror telescopes/cameras that have no coma, no spherical aberration and arbitrarily fast focal ratios form a two-parameter (s, K) family of exact optical designs analytically derived earlier. We explore the full range of these designs in the s‐K plane. Here s is the mirror separation/focal length and K is the distance from secondary to focus/focal length. Besides perfect-focus analogues of most well-known telescope designs, there are families of spectrograph cameras, X-ray telescopes and solar furnaces. Systems with s = 2 have minimum astigmatism and have exceptionally good images.
Cascading Wiener-Hammerstein systems

In this paper we study the cascading of weakly nonlinear systems. It is shown that the best linear approximation of the cascaded system is given by the product of the best linear approximation to the first and second nonlinear system respectively. This approximation is valid in the frequency range where both coherences of the individual linear approximations are high. In case both cascaded systems are Wiener-Hammerstein, the coherence provides also insight into the distribution of the dynamics over both system.
GENERALIZED CONTINGENT EPIDERIVATIVES IN SET-VALUED OPTIMIZATION: OPTIMALITY CONDITIONS

ABSTRACT Necessary and sufficient optimality conditions are given for various optimality notions in set-valued optimization. These optimality conditions are given by employing the generalized contingent epiderivative and the weak contingent epiderivative of the objective set-valued map and the set-valued map defining the constraints. The known Lagrange multiplier rule and the so-called Zowe-Kurcyusz-Robinson (cf. Robinson, S.M. Stability Theory for Systems of Inequalities. II, Differentiable Nonlinear Systems. SIAM J. Numer. Anal. 1976, 13, 497–513. Zowe, J.; Kurcyusz, S. Regularity and Stability for the Mathematical Programming Problem in Banach spaces, Appl. Math. Optim 1979, 5, 49–62.) regularity condition are extended using these differentiability notions.
Development and performance of a 320 x 256 quantum well infrared photodector camera

A 9.3 micrometer cutoff 320 X 256 quantum well infrared photodetector (QWIP) based thermal camera has been demonstrated as a laboratory set-up configuration. The development of the QWIP arrays and system integration is described. Performance analysis of systems which are based on QWIP arrays were performed to evaluate the potential of 320 X 256 and 640 X 480 QWIP array to be a candidate for future mid-end and high-end thermal imager.
Journal of Quantitative Analysis in Sports A Simple and Flexible Rating Method for Predicting Success in the NCAA Basketball Tournament

This paper first presents a brief review of potential rating tools and methods for predicting success in the NCAA basketball tournament, including those methods (such as the Ratings Percentage Index, or RPI) that receive a great deal of weight in selecting and seeding teams for the tournament. The paper then proposes a simple and flexible rating method based on ordinal logistic regression and expectation (the OLRE method) that is designed to predict success for those teams selected to participate in the NCAA tournament. A simulation based on the parametric BradleyTerry model for paired comparisons is used to demonstrate the ability of the computationally simple OLRE method to predict success in the tournament, using actual NCAA tournament data. Given that the proposed method can incorporate several different predictors of success in the NCAA tournament when calculating a rating, and has better predictive power than a model-based approach, it should be strongly considered as an alternative to other rating methods currently used to assign seeds and regions to the teams selected to play in the tournament.
Analysis of the microstrip disk antenna element

The circular microstrip antenna element is formed by a radiating disk closely spaced above a ground plane. It is modeled as a cylindrical cavity with magnetic walls which can be resonant in the transverse magnetic (TM) modes. The far fields and the radiation conductances for different mode structures have been calculated assuming a magnetic line current flowing along the perimeter of the disk. The directivity of a disk antenna excited in the dominant mode is between 4.8 dB and 9.9 dB, depending on the size. Losses, due to imperfect supporting dielectrics and to the finite conductivity of the conductors, have been derived by means of a perturbation technique. Graphs are given for design purposes showing the input impedance, the Q factor, and the radiation efficiency at resonance for different modes and thicknesses. The air-filled microstrip antenna has the highest efficiency and the broadest bandwidth at a given resonant frequency.
A Brouwer translation theorem for free homeomorphisms

We prove a generalization of the Brouwer Translation Theorem which applies to a class of homeomorphisms (free homeomorphisms) which admit fixed points, but retain a dynamical property of fixed point free orientation preserving homeomorphsims. That is, if h: M2 M2 is a free homeomorphism where M2 is a surface, then whenever D is a disc and h(D) n D = 0, we have that hn(D) n D = 0 for all n £ 0 THEOREM. Let h be a free homeomorphism of S2, the two-sphere, with finite fixed point set F. Then each p E S2-F lies in the image of an embedding Xp: (R2, O) (S2 _ F, p) such that: (i) hXp-Xpf, where Er(z)-z + 1 is the canonical tranalation of the plane, and (ii) the image of each vertical line under Xp is closed in S2-F. The class of free homeomorphisms has been introduced and studied by M. Brown in connection with the dynamics of surface homeomorphisms. Introduction. L. E. J. Brouwer, from 1909 to 1919, formulated and presented the Brouwer Plane Translation Theorem [2-6, 9, 10]. In modern terminology it can be stated thusly. THEOREM. Let h be a fixed point free orientation preserving self homeomorphism of R2, the plane. Then each p E R2 lies in the image of an embedding Xp: (R2,0) ) (R2,p) such that: (i) hXp-Xpor, where or(z) = z + 1 is the canonical translation of the plane, and (ii) the image of each vertical line under Xp is closed in R2. In his first proof of this theorem [3-6] he assumed that a simple curve bounded only two domains. Later [7] he discovered the Lakes of Wada continuum and realized the error in his proof. The second proof [9] utilized the Brouwer Translation Arc Lemma, which was proved using the No Retraction Theorem [8] and the concept of index of a fixed point. However, this proof contained serious gaps. Since 1920 a succession of authors [1, 13-16, 17, 18] have presented proofs of this theorem, each either correcting errors in the previous proof or embarking upon a simplification for the proof. For a more thorough discussion of this problem, the reader should consult [11] which presents the history of Brouwer's work and [16] for the history of the plane translation theorem. Received by the editors August 18, 1986. 1980 Mathematics Subject Classification (1985 Revision). Primary 54H20; Secondary 58F99.
Algorithms and resource requirements for fundamental problems

We establish more efficient methods for solving interesting classes of NP-hard problems exactly, as well as methods for proving limitations on how quickly those and other problems can be solved. (1) On the negative side, we prove that a number of NP-hard problems cannot be solved too efficiently by algorithms that only use a small amount of additional workspace. Building on prior work in the area, we prove that the Boolean satisfiability problem and other hard problems require Ω(n2cos(π/7)- o(1)) ≥ Ω( n1.801) time to solve by any algorithm that uses no(1) space. Stronger lower bounds are proved for solving quantified Boolean formulas with a fixed number of quantifiers. Our results are essentially model-independent, in that they hold for all reasonable random-access machine models. Furthermore, we present a formal proof system that captures all prior time-space lower bounds for satisfiability (including our own), and demonstrate how the search for better lower bounds can be automated, in not only our particular setting but also other lower bounds that follow a certain high-level pattern. We describe an implementation of an automated theorem prover and provide experimental results which strongly suggest that further improvements on the above time lower bound will require new tools and ideas. (2) On the positive side, we give a general methodology for solving a large class of NP-hard problems much faster than exhaustive search. In particular, for a problem in the class where exhaustive search of all possible solutions takes Θ(N ) time, our algorithm solves the problem in O( Nδ) time, for a universal constant δ < 0.792 that depends on the complexity of multiplying two matrices over a ring. We also provide theoretical evidence that a much larger class of problems admits a similar type of algorithm. To illustrate our results, consider the MAX CUT problem, where one is given a graph G = ( V, E) and integer K, and one wishes to determine if G has a subset of vertices such that the number of edges leaving the subset is at least K. The obvious algorithm for MAX CUT runs in O(poly( n) · 2n) time, where n = |V|. Despite the problem's importance, no better algorithm was known for the general case of MAX CUT , prior to our work. Our results imply that MAX C UT can be solved in O( 3 n ) time but cannot be solved in O(n1.801) time and n o(1) space.
On the formation of elliptical galaxies

Simple collapse and violent relaxation models produce sharply cut off envelopes with rho (r) proportionalr$sup -4$, whereas actual elliptical galaxies have more extended envelopes approximately given by rho (r) Ir$sup -3$ as implied by Hubble's law. Numerical models are presented, showing that when cosmological infall effects are included, galaxies are produced with envelopes having a rho (r) Ir$sup -2$. $sup 8$ dependence in excellent agreement with Hubble's law. A realistic rotating model is computed of an E5 galaxy which includes infall effects and where the angular momentum of the galaxy is gained through tidal interactions with neighboring protogalaxies. The envelope displays a Hubble dependence but at great distances shows a cutoff due to the tidal effects. The model gives an outstandingly good fit to the envelope of the E5 galaxy NGC 4697. Except for simple scaling, this fit is produced without the use of any free- fitting parameters. A mass-to-light ratio for NGC 4697 is also computed. (AIP)