Miracle-dz/UniFAR-FTUs huggingface dataset:
Book Review: Statistical Methods for Handling Incomplete Data, by Jae Kwang Kim and Jun Shao

Incomplete data sets have long been a part of statistical data analysis. The most common practice for dealing with subjects with missing observations is to delete those observations with missing data and analyze only the completely observed cases. There are serious drawbacks to such an approach, however. One might potentially eliminate a lot of data that took a great deal of time and expense to collect. In addition, analysis of only the complete observations may bias the results if the completely observed responses differ in some way from those with missing data. While incomplete data have been a topic of interest for many years (Dempster et al., 1977), recent years have seen a large increase in the number of methods for dealing with it and their applications. Jae Kwang Kim and Jun Shao’s book Statistical Methods for Handling Incomplete Data is an excellent synopsis of the many incomplete data methods that are available and their mathematical justifications. However, readers seeking details on the implementation of these methods in an applied setting or details of software that is available will have to turn elsewhere. Each chapter of this book covers an array of statistical methods for dealing with incomplete data. This book is mathematically rigorous, and does not lend itself to casual reading. A background in probability theory would help immensely with understanding the material. Chapter 2 introduces definitions and the likelihood function. This is followed by computation of the maximum likelihood via several approaches: Newton’s method, a quasiNewton method, factoring the likelihood, the expectation maximization (EM) algorithm, Monte Carlo, and data augmentation. Theoretical proofs and justifications are given for each method. Chapter 4 of the book focuses on imputation. The basic theory and variance estimation after a single imputation are presented, and these are then extended to multiple imputation and fractional imputation. Chapter 5 moves on to propensity scoring. Within this context, the book discusses optimal estimation, a doubly robust method, and empirical likelihood. Chapter 6 covers nonignorable missing data, where the missingness of an observation depends on the value of the missing variable itself. Methods here include partial likelihood, generalized method of moments (GMM), pseudo-likelihood, and the exponential tilting (ET) model. This chapter also discusses a latent variable approach. Chapters 7 through 9 are intended as chapters for future reference rather than as part of a course in incomplete data. Chapter 7 looks at longitudinal and clustered data, chapter 8 considers survey sampling, and chapter 9 covers statistical matching. While these
On the combinatorial structure of 0/1-matrices representing nonobtuse simplices

A 0/1-simplex is the convex hull of n+1 affinely independent vertices of the unit n-cube In. It is nonobtuse if none of its dihedral angles is obtuse, and acute if additionally none of them is right. Acute 0/1-simplices in In can be represented by 0/1-matrices P of size n × n whose Gramians G = P⊤P have an inverse that is strictly diagonally dominant, with negative off-diagonal entries. In this paper, we will prove that the positive part D of the transposed inverse P−⊤ of P is doubly stochastic and has the same support as P. In fact, P has a fully indecomposable doubly stochastic pattern. The negative part C of P−⊤ is strictly row-substochastic and its support is complementary to that of D, showing that P−⊤ = D−C has no zero entries and has positive row sums. As a consequence, for each facet F of an acute 0/1-facet S there exists at most one other acute 0/1-simplex Ŝ in In having F as a facet. We call Ŝ the acute neighbor of S at F. If P represents a 0/1-simplex that is merely nonobtuse, the inverse of G = P⊤P is only weakly diagonally dominant and has nonpositive off-diagonal entries. These matrices play an important role in finite element approximation of elliptic and parabolic problems, since they guarantee discrete maximum and comparison principles. Consequently, P−⊤ can have entries equal to zero. We show that its positive part D is still doubly stochastic, but its support may be strictly contained in the support of P. This allows P to have no doubly stochastic pattern and to be partly decomposable. In theory, this might cause a nonobtuse 0/1-simplex S to have several nonobtuse neighbors Ŝ at each of its facets. In this paper, we study nonobtuse 0/1-simplices S having a partly decomposable matrix representation P. We prove that if S has such a matrix representation, it also has a block diagonal matrix representation with at least two diagonal blocks. Moreover, all matrix representations of S will then be partly decomposable. This proves that the combinatorial property of having a fully indecomposable matrix representation with doubly stochastic pattern is a geometrical property of a subclass of nonobtuse 0/1-simplices, invariant under all n-cube symmetries. We will show that a nonobtuse simplex with partly decomposable matrix representation can be split in mutually orthogonal simplicial facets whose dimensions add up to n, and in which each facet has a fully indecomposable matrix representation. Using this insight, we are able to extend the one neighbor theorem for acute simplices to a larger class of nonobtuse simplices.
Higher-dimensional ancilla-driven quantum computation

A model of universal quantum computation with qudits ($d$-level systems) is presented in which the gates are implemented on a register entirely via fixed-form sequential interactions with ancillary qudits followed by adaptive, variable basis measurements of these ancillas. The model maintains determinism via classical feed-forward of measurement outcomes in a similar fashion to the qudit one-way model. An embedding of the qudit one-way model is given which demonstrates that the hybrid quantum-classical advantages of one-way quantum computation are also inherent in the model presented here, including the ability to implement any Clifford gate in constant depth using multiple ancillas in parallel. A model which requires only fixed basis measurements is then presented, but due to the lack of adaptive controls it can only implement universal quantum computation in a stochastic sense. Interestingly, this scheme may then be altered to recover determinism by replacing ancilla measurements with ancilla preparation. These models provide an intuitive setting for understanding the interplay between the benefits gained from classical controls, measurements and state preparation in the context of multi-valued logic ancilla-based quantum computation.
Speech enhancement using vector quantization and a formant distance measure

A system to improve the intelligibility of noisy speech through the use of vector quantization of linear predictive coding (LPC) spectra and a distance measure involving formants is described. Based on experiments using the system on natural speech degraded by additive white noise, the approach appears to be a promising way to transform noisy speech into more intelligible signals. As the noise corruption increases (and SRN decreases), the output speech becomes more distorted in terms of spectral jumps and mismatches, but remains free of noise. Good intelligibility remains as low as 9 dB SNR, although the speech is unnatural due to the LPC synthesis. <<ETX>>
Nitrogen-vacancy center in diamond: Model of the electronic structure and associated dynamics

Symmetry considerations are used in presenting a model of the electronic structure and the associated dynamics of the nitrogen-vacancy center in diamond. The model accounts for the occurrence of optically induced spin polarization, for the change of emission level with spin polarization and for new measurements of transient emission. The rate constants given are in variance to those reported previously.
Diamond field effect transistors with a high-dielectric constant Ta2O5 as gate material

A Ta2O5/Al2O3 bilayer gate oxide with a high-dielectric constant (high-k) has been successfully applied to a hydrogenated-diamond (H-diamond) metal-insulator-semiconductor field effect transistor (MISFET). The Ta2O5 layer is prepared by a sputtering-deposition (SD) technique on the Al2O3 buffer layer fabricated by an atomic layer deposition (ALD) technique. The ALD-Al2O3 plays an important role to eliminate plasma damage for the H-diamond surface during SD-Ta2O5 deposition. The dielectric constants of the SD-Ta2O5/ALD-Al2O3 bilayer and single SD-Ta2O5 are as large as 12.7 and 16.5, respectively. The k value of the single SD-Ta2O5 in this study is in good agreement with that of the SD-Ta2O5 on oxygen-terminated diamond. The capacitance–voltage characteristic suggests low interfacial trapped charge density for the SD-Ta2O5/ALD-Al2O3/H-diamond MIS diode. The MISFET with a gate length of 4 µm has a drain current maximum and an extrinsic transconductance of −97.7 mA mm−1 (normalized by gate width) and 31.0 ± 0.1 mS mm−1, respectively. The effective mobility in the H-diamond channel layer is found to be 70.1 ± 0.5 cm2 V−1 s−1.
NLST: the Indian National Large Solar Telescope

India is planning a new solar telescope with an aperture of 2-m for carrying out high resolution studies of the Sun. Site characterization is underway at high altitude locations in the Himalayan mountains. A detailed concept design for NLST (National Large Solar Telescope) has been completed. The optical design of the telescope is optimized for high optical throughput and uses a minimum number of optical elements. A high order AO system is integrated part of the design that works with a modest Fried's parameter of 7-cm to give diffraction limited performance. The telescope will be equipped with a suite of post-focus instruments including a high resolution spectrograph and a polarimeter. NLST will also be used for carrying out stellar observations during the night. The mechanical design of the telescope, building, and the innovative dome is optimized to take advantage of the natural air flush which will help to keep the open telescope in temperature equilibrium. After its completion (planned for 2014), NLST will fill a gap in longitude between the major solar facilities in USA and Europe, and it will be for years the largest solar telescope in the world
Generalized MLE of a Joint Distribution Function with Multivariate Interval-Censored Data

We consider the problem of estimation of a joint distribution function of a multivariate random vector with interval-censored data. The generalized maximum likelihood estimator of the distribution function is studied and its consistency and asymptotic normality are established under the case 2 multivariate interval censorship model and discrete assumptions on the censoring random vectors.
Room‐temperature normal‐mode coupling in a semiconductor microcavity utilizing native‐oxide AlAl/GaAs mirrors

A GaAs/AlAs microcavity containing six InGaAs quantum wells was grown, and the sample was then etched via chemically‐assisted ion‐beam etching to form 50‐μm‐diam cylindrical mesas. The formation of native oxides, accomplished by baking the samples at 400 °C in the presence of a pressurized N2/H2O vapor line, lowered the refractive index of the AlAs layers to 1.5. The higher refractive index contrast more effectively confined the intracavity field, leading to well‐resolved reflectivity dips with an exciton‐polariton splitting of 6.72 nm=9.44 meV at room temperature.
A determinant representation for the distribution of quadratic forms in complex normal vectors

Let the column vectors of X:: M×N, M<N, be distributed as independent complex normal vectors with the same covariance matrix Σ. Then the usual quadratic form in the complex normal vectors is denoted by Z=XLXH where L: N×N is a positive definite hermitian matrix. This paper deals with a representation for the density function of Z in terms of a ratio of determinants. This representation also yields a compact form for the distribution of the generalized variance |Z|.
A Method for Predicting Chinook Winds East of the Montana Rockies

Abstract Damaging foehn winds, locally known as “chinook” winds, are loosely defined and generally described for the east slopes of the Montana Rockies. Three upper-level patterns associated with chinook episodes in Montana are described and illustrated. The “basin high” pattern is characterized by a strong surface high pressure system in the Great Basin, and is associated with light to moderate southwest winds and mild temperatures along the east slopes of the Rockies. The “Klondike” pattern is associated with chinook winds when slightly warmer air replaces an arctic air mass that has pushed southward over Montana. The “frontal” pattern produces the most significant and damaging chinook wind episodes and occurs when a rapidly moving Pacific cold front sweeps into Montana or southern Alberta as a ridge remains farther south over the western United States. An objective aid for forecasting the strength of wind gusts for the frontal chinook pattern at Great Falls, and other locations in the chinook belt, is .
On the Formulation of Uniform Laws of Large Numbers: a Truncation Approach

The paper develops a general framework for the formulation of generic uniform laws of large numbers. In particular, we introduce a basic generic uniform law of large numbers that contains recent uniform laws of large numbers by Andrews [2] and Hoadley [7J as special cases. We also develop a truncation approach . that makes it possible to obtain uniform laws of large numbers for the functions under consideration from uniform laws of large numbers for truncated versions of those functions. The point of the truncation approach is that uniform laws of large numbers for the truncated versions are typically easier to obtain. By combining the basic uniform law of large numbers and the truncation approach we also derive generalizations of recent uniform laws of large numbers introduced in Potscher and Prucha [13, l5].
Corrections for Response Errors in a Three-Component Propeller Anemometer

Abstract Methods of eliminating or reducing three types of errors found in the Gill UVW anemometer have been investigated by utilizing field experiments comparing this sensor with a three-component sonic anemometer. The non-cosine response of each of the three orthogonal propellers to a wind which is not parallel to the propeller axis was adequately corrected during computer processing of the data, using the manufacturer's wind-tunnel-measured calibrations. The accepted theory describing a propeller as a first-order system with a time constant τ = L/ū (where L is a distance constant characterizing the propeller inertia and ū is the mean wind) was found to be only a fair description of the frequency response, probably due to dependence of L on properties of the flow, but was used to qualitatively delineate proper applications for this sensor. The threshold response was improved for the U and V components by orienting the anemometer so that the mean wind direction bisects the angle between the horizontal ax.
Clumping and small-scale mixing in supernova 1987A

We investigate high-resolution line profiles of Hα, [Fe II] 7155 A and Ca II] 7291,7323 A in the spectra of SN 1987A. We identify a common prominent narrow feature in all four lines. We attribute the emission to a fast knot of metals and hydrogen. Our observations provide the first direct evidence for mixing on a small as well as a large scale in the ejecta of SN 1987A. Our observations support the idea that such knots may well have contributed the bulk of the emission of the supernova after the ejecta cooled and dust formed at about day 500. The ratio of the two components of the blend of Ca II] 7291,7323 A provides an upper limit on the number density of Ca + of 1 × 10 5 cm −3 on day 673 for both the knot and the rest of the ejecta
The 3D MHD code GOEMHD3 for astrophysical plasmas with large Reynolds numbers Code description, verification, and computational performance

The numerical simulation of turbulence and flows in almost ideal, large-Reynolds-number astrophysical plasmas motivates the implementation of almost conservative MHD computer codes. They should efficiently calculate, use highly parallelized schemes scaling well with large numbers of CPU cores, allows to obtain a high grid resolution over large simulation domains and which can easily be adapted to new computer architectures as well as to new initial and boundary conditions, allow modular extensions. The new massively parallel simulation code GOEMHD3 enables efficient and fast simulations of almost ideal, large-Reynolds-number astrophysical plasma flows, well resolved and on huge grids covering large domains. Its abilities are validated by major tests of ideal and weakly dissipative plasma phenomena. The high resolution ($2048^3$ grid points) simulation of a large part of the solar corona above an observed active region proved the excellent parallel scalability of the code using more than 30.000 processor cores.
Non-Asymptotic and Asymptotic Analyses of Information Processing on Markov Chains

In this paper, we derive non-asymptotic achievability and converse bounds on the source coding with/without side-information, the random number generation with/without side-information, and the channel coding for the regular channel. Our bounds are efficiently computable in the sense that the computational complexity does not depend on the block length. We also characterize the asymptotic behaviors of the large deviation regime and the moderate deviation regime by using our bounds, which implies that our bounds are asymptotically tight in those regimes. We also show the second order rates of those problems, and derive single letter forms of the variances characterizing the second order rates.
Horizontal grids for global weather and climate prediction models: a review

A latitude–longitude grid is used by almost all operational atmospheric forecast models, and many research models. However, it is expected that the advantages of a latitude–longitude grid will become outweighed on massively parallel computers by data‐communication bottlenecks. There is therefore renewed interest in quasi‐uniform alternatives. This review surveys and assesses previously proposed horizontal grids for modelling the atmosphere over the sphere. Aspects of numerical accuracy likely to be affected by grid structure are discussed; particular attention is paid to computational modes and grid imprinting. Computational modes are potentially very serious, since they may be excited in realistic applications by boundary conditions, nonlinearity, physical forcing, and data assimilation. The geometry of polyhedra is reviewed due to its relation to numerical degrees of freedom, and hence to numerical wave dispersion and the possible existence of computational modes.
A reliability modeling framework for the hard disk drive development process

Motivated by the fact that the major causes of catastrophic failure in micro hard disk drives are mostly induced by the presence of particles, a new particle-induced failure susceptibility metric, called the Cumulative Particle Counts (CPC), is proposed for managing reliability risk in a fast-paced hard disk drive product development process. This work is thought to represent the first successful attempt to predict particle-induced failure through an accelerated testing framework which leverages on existing streams of research for both particle-injection-based and inherent-particle-generation laboratory experiments to produce a practical reliability prediction framework. In particular, a new testing technique that injects particles into hard disk drives so as to increase the susceptibility of failure is introduced. The experimental results are then analyzed through a proposed framework which comprises the modeling of a CPC-to-failure distribution. The framework also requires the estimation of the growth curve for the CPC in a prime hard disk drive under normal operating conditions without particle injection. Both parametric and non-parametric inferences are presented for the estimation of the CPC growth curve. Statistical inferential procedures are developed in relation to a proposed non-linear CPC growth curve with a change-point. Finally, two applications of the framework to design selection during an actual hard disk drive development project and the subsequent assessment of reliability growth are discussed.
Phase retrieval–based distribution detecting method for transparent objects

Abstract. A distribution detecting method to recover the distribution of transparent objects from their diffraction intensities is proposed. First, on the basis of the Gerchberg-Saxton algorithm, a wavefront function involving the phase change of the object is retrieved from the incident light intensity and the diffraction intensity, then the phase change of the object is calculated from the retrieved wavefront function by using a gradient field-based phase estimation algorithm, which circumvents the common phase wrapping problem. Finally, a linear model between the distribution of the object and the phase change is set up, and the distribution of the object can be calculated from the obtained phase change. The effectiveness of the proposed method is verified with simulations and experiments.
A theoretical study of an isolated transition using an iterative hysteretic model

Recently Iwasaki and Suzuki pointed out that demagnetization could conceivably be very significant during the writing process and presented a self-consistent iterative calculation of the writing process which confirmed their views. In the present study we extend their scheme to study an isolated transition region of finite track width by considering what happens to the transition when the head field is removed. Of particular significance in the final calculated results is the high asymmetry of the magnetization distribution. A detailed comparison was done between the results of the iterative calculation and previous theories of the transition region over a large range of material parameters. It is found that the iteratively calculated transition regions are significantly larger than those calculated by previous authors. Results are also compared to experimental data obtained by electron microscopy.
Further Evidence for Large Grains in the Dust Shell Surrounding AG Carinae

Abstract There is growing evidence for the notion that large grains are an important constituent of the interstellar medium. It has been found to be necessary to invoke the presence of large grains (of radius a > 1.0 μm) in a number of circumstellar shells, including those around Eta Carinae, and some late type giants and supergiants. Most recently, as a result of IRAS observations, the same idea has been used in the interpretation of the extensive optically thin disks found around some young early type stars. It is important to establish size constraints on these grains, so as to determine better the probable mix of interstellar grains. Previous work on AG Carinae suggested merely that the grains in the circumstellar shell need to be larger than 1 μm, but gave no information regarding the maximum size which would be acceptable. In this paper, we explore the question of the characteristic size of the dust grains in the AG Carinae shell, by fitting the spatially integrated model energy distribution to observations over the wavelength range 360 nm–100 μm, and conclude that silicate grains of radius ~ 1.0 μm give a satisfactory fit to the spectrum and angular distribution, but that grains appreciably larger or smaller than this radius are unsatisfactory.