Miracle-dz/UniFAR-FTUs huggingface dataset:
The effect of time steps and time‐scales on parametrization suites

The problem of intense, truncation‐scale storms that form in high‐resolution versions of the Community Atmosphere Model Version 4 (CAM4) is studied. These storms are characterized by extreme vertical motion and heavy precipitation. This problem arises when some individual parametrizations do not produce an atmospheric‐like state because they are restrained by the time‐scales assumed in their formulation; other unconstrained parametrizations that follow then work in unintended ways. The behaviour of the moist parametrization components is examined in CAM4 for one typical, strong cell. At T340 spectral truncation with a 5 min time step, the deep and shallow convection parametrizations do not remove instabilities and supersaturation because they have time‐scales of 1 h and 30 min, respectively. Then the prognostic cloud‐water scheme, which is not constrained by a time‐scale, does remove supersaturation. That local release of latent heat drives very strong vertical motion and horizontal convergence, which transports even more water vapour into the column, exacerbating the problem. Two simple model problems are introduced that illustrate the ramifications of the time‐scale and time‐step mismatch. When either the time‐scales are shortened or the time step is lengthened, the convection parametrizations are more active and strong storms do not form. Copyright © 2012 Royal Meteorological Society
The Role of a Group of Modules in the Failure of Systems

Consider a system consisting of a number of modules. The probability that a particular module is among the ones that have already failed by the time of system failure can be used as a measure of the importance of that module. In El-Neweihi and Sethuraman [6], this probability was called the role of a module in the failure of a system and its properties were developed. In this article we propose the number of failed modules from among a particular subgroup of modules as the basis for measuring the role of that subgroup of modules. We study some monotonicity properties of the distribution of that random variable, in some second order r-out-of-k systems. We illustrate the possible extensions of these results to multistate systems. Yet another measure of the role of a particular subgroup of modules can be based on the number of failed components from this subgroup by the time of system failure. We derive some monotonicity properties of the expected value of the number of such failed components.
Black Holes: The Membrane Paradigm

The physics of black holes is explored in terms of a membrane paradigm which treats the event horizon as a two-dimensional membrane embedded in three-dimensional space. A 3+1 formalism is used to split Schwarzschild space-time and the laws of physics outside a nonrotating hole, which permits treatment of the atmosphere in terms of the physical properties of thin slices. The model is applied to perturbed slowly or rapidly rotating and nonrotating holes, and to quantify the electric and magnetic fields and eddy currents passing through a membrane surface which represents a stretched horizon. Features of tidal gravitational fields in the vicinity of the horizon, quasars and active galalctic nuclei, the alignment of jets perpendicular to accretion disks, and the effects of black holes at the center of ellipsoidal star clusters are investigated. Attention is also given to a black hole in a binary system and the interactions of black holes with matter that is either near or very far from the event horizon. Finally, a statistical mechanics treatment is used to derive a second law of thermodynamics for a perfectly thermal atmosphere of a black hole.
Blue, Green, and Amber InGaN/GaN Light-Emitting Diodes on Semipolar {11-22} GaN Bulk Substrates

We demonstrate the fabrication of blue, green, and amber InGaN/GaN light-emitting diodes (LEDs) on semipolar {11-22} bulk GaN substrates. The {11-22}GaN substrates used in this study are produced by cutting out from a c-oriented GaN bulk crystal grown by hydride vapor epitaxy. The LEDs have a dimension of 320 ×320 µm2 and are packed in an epoxide resin. The output power and external quantum efficiency (EQE) at a driving current of 20 mA are 1.76 mW and 3.0%, respectively, for the blue LED, 1.91 mW and 4.1% for the green LED, and 0.54 mW and 1.3% for the amber LED. The maximum output powers obtained with a maximum current of 200 mA are 19.0 mW (blue), 13.4 mW (green), and 1.9 mW (amber), while the maximum EQEs are 4.0% at 140 mA (blue), 4.9% at 0.2 mA (green), and 1.6% at 1 mA (amber). It is confirmed that the emission light is polarized along the [1-100] direction, reflecting the low crystal symmetry of the {11-22} plane.
Testing for Serial Correlation against an ARMA(1,1) Process

Abstract This article is concerned with tests for serial correlation in time series and in the errors of regression models. In particular, the nonstandard problem of testing for white noise against autoregressive moving average model ARMA(1, 1) alternatives is considered. The likelihood ratio (LR), sup Lagrange multiplier (LM), and exponential average LM and LR tests are shown to be asymptotically admissible for ARMA(1, 1) alternatives. In addition, they are shown to be consistent against all (weakly stationary strong mixing) non-white noise alternatives. Simulation results compare the tests to several tests in the literature. These results show that the LR and Exp-LR∞ tests have very good all-around power properties for nonseasonal alternatives.
Factor Based Identification-Robust Inference in IV Regressions

Robust methods for IV inference have received considerable attention recently. Their analysis has raised a variety of problematic issues such as size/power trade-offs resulting from weak or many instruments. We show that information-reduction methods provide a useful and practical solution to this and related problems. Formally, we propose factor-based modifications to three popular weak-instrument-robust statistics, and illustrate their validity asymptotically and in finite samples. Results are derived using asymptotic settings that are commonly used in both the factor and weak instrument literatures. For the Anderson-Rubin statistic, we also provide analytical finite sample results that do not require any underlying factor structure. An illustrative Monte Carlo study reveals the following. Factor based tests control size regardless of instruments and factor quality. All factor based tests are systematically more powerful than standard counterparts. With informative instruments and in contrast with standard tests: (i) power of factor-based tests is not affected by k even when large, and (ii) weak factor structure does not cost power. An empirical study on a New Keynesian macroeconomic model suggests that our factor-based methods can bridge a number of gaps between structural and statistical modeling.
Radio-frequency electronegative gas discharge behaviour in a parallel-plate reactor for material processing

In this paper, a second-order continuum model for radio-frequency glow discharge plasma between parallel-plate electrodes is presented. Simulations have been performed for discharges in argon and O2. The basic data needed for different collision processes are explicitly given with a high degree of accuracy. These data are rigorously calculated by using a multiterm Boltzmann equation solution for electrons and a Monte Carlo simulation technique for ions. The specificity of the present work is the use of a second-order fluid model solved by using a powerful finite-element scheme associated with basic data rigorously calculated. Detailed results for two types of discharge are presented and contrasted. The phenomena associated with the transition of the discharge into different operating regimes at relatively low and high pressures are demonstrated and discussed.
Theory of electron multipactor in crossed fields

A general theory of multipactor in orthogonal electric and magnetic fields is given. The model consists of two parallel plates of known secondary emission properties, across which a time varying voltage is applied, and between which a constant magnetic field is applied. Expressions are derived for the resonant phases at which the RF‐driven cascades occur; these reduce to previously derived expressions in the limit of the vanishing magnetic field. In addition, this work obtains the conditions governing the stability of the motion about those phases, as well as a dynamic constraint from imposing the restriction that each impact on a plate is the first impact that is allowed by the equations of motion. Chaotic effects from the random ejection velocities of the secondaries are addressed for the first time. It is proven that the phase focusing effect from the radio frequency (RF) interaction will overcome the dispersive effect from the random emission, provided that the mean square emission velocity is suffici.
On-Chip Single-Cell Lysis for Extracting Intracellular Material

A newly designed microfluidic chip with a pinched-channel structure and two pairs of electrodes has been developed to enable easier single-cell capture and lysis. The function of the chip was evaluated by introducing zucchini protoplast cells into the channel. In the first experiment, we attempted to break a cell using the through force of a triangular pinched structure via electroosmotic flow generated by outer electrodes. The pinched structure appeared to break the cell without applying the electric field to the cell directly; however, in this case, the breakable size of the cell was limited by the width of the pinched structure. The next attempt was to break cells regardless of their sizes using a pair of inner electrodes located under the pinched structure. The inner electrodes generated a gradient electric field around the captured cell by applying an alternative voltage to the electrodes. Captured cells with a diameter from 40 to 85 µm could be broken using the inner electrodes with a trapezoidal pinched structure, and the cells were successfully broken at 10 Vpp or less at a frequency of 1 MHz.
A new result on the delay‐dependent stability of discrete systems with time‐varying delays

This paper proposes an improvement to the delay‐dependent stability of discrete systems with time‐varying delays. The approach is based on the observation that the positive definiteness of a chosen Lyapunov–Krasovskii functional does not necessarily require all the involved symmetric matrices to be positive definite, which has been overlooked in the literature. The derived delay‐dependent stability conditions are in terms of linear matrix inequalities. It is theoretically proved that our results are less conservative than the corresponding ones obtained by requiring the positive definiteness of all the symmetric matrices in a chosen Lyapunov–Krasovskii functional. The importance of the present approach is that a great number of delay‐dependent analysis and synthesis results obtained by the aforementioned requirement in the literature can be improved by the present approach without introducing any new decision variables. Copyright © 2013 John Wiley & Sons, Ltd.
Passive vocal tract enlargement during voiced stops

Voiced stops should become devoiced within 5 to 10 m of stop closure if there is no vocal tract enlargement to delay the inevitable reduction in transglottal pressure drop. Since stops may be voiced longer than this, some cavity expansion must take place, either passive through tissue compliance or active through larynx lowering and the like. To estimate the duration of voicing in stops when only passive enlargement occurs, subjects produced isolated nonsense words of the form VC:V, where V was one of a variety of English vowels and C: was an artificially prolonged /b/, /d/, or/g/. Oral air pressure was vented through a catheter leading from the pharynx to the atmosphere via the nasal cavity. At unpredictable times, a solenoid‐activated valve closed the catheter and the consequent build‐up of oral pressure extinguished the voicing. Voicing continued after this closure longer during /b/ than /d/ or /g/, and longer when coarticulated with high vowels than with low vowels. These results can most plausibly be.
The spacing of streaks in unsteady turbulent wall‐bounded flow

1.lNTRODiJCTlON Streamwise streaks of relatively low- and high-speed fluid are distinctive features of near-wall turbulent flow. They are believed to arise through the process of redistribution of streamwise momentum by cross-stream roll-like motions, and play a central role in the production of turbulence. Since some of the earliest observations of these motions in a turbulent boundary layer were made by Kline and Runstadler,’ many subsequent studies have confirmed them to be general features of wall-bounded turbulent flow~. ~-~ The more recent numerical simulations of Lee et al’ have demonstrated that very similar streaks may be formed-by high shear rates alone in homogeneous turbulent shear flows, without the need for blocking by a solid boundary; the spacing of these streaks was nearly twice those of wall-bounded flows when scaled by the local shear velocity. They have also shown that the mechanisms of streak generation and evolution are reproduced by the equations of turbulent motion in the rapiddistortion approximation: thus streaks arise predominantly through linear distortions of turbulence by the mean shear rather than through nonlinear turbulent interactions. In this spirit, Landahl’ adopted an approach similar to the rapiddistortion approximation, with nonlinear effects retained for sufficient time to establish initial conditions, and demonstrated how streak-like motions evolved from certain threedimensional disturbances. One of the
Active biomonitoring of air radioactivity in urban areas

To assess the validity of the moss bag monitoring technique in the radioactivity control of ground level urban air, a study on radionuclide contents in moss was performed in the city of Belgrade, Serbia. From May 2006 to May 2007, moss (Sphagnum girgensohni, Dubna, Russia) was exposed to the aero pollution in a location in the central area of the city. The activity of 40K, 210Pb, and 137Cs was measured on an HPGe detector (Canberra, relative efficiency 23%) by standard gamma spectrometry. The activities 245 ± 25 Bq/kg for 40K, 315 ± 34 Bq/kg for 210Pb, and 28 ± 4 Bq/kg for 137Cs are in the range of values reported for the region; the differences are due to the moss species, local climate and measuring technique. Taking into consideration the time of the exposure and appropriate calibration procedure, moss bag biomonitoring could be used as a complementary method for determination of radionuclides in urban air.
From the discovery of the partially bilayer smectic A phase to blue phases in polar liquid crystals

The significance of Gray’s cyanobiphenyls in the discovery of the partially bilayer smectic A phase (SmAd) and in the formulation of mixtures exhibiting the blue phase is described. The properties of the SmAd phase and its relationships to molecular structures are reviewed. Induced phenomena such as the transformation of nematics into smectics, SmAd or SmA1, as well as the opposite transformation of smectics into nematics are described and discussed.
Vibrations and Stability of Multiple Parameter Systems

Linear, elastic systems subjected to time-independent loads are treated in this book. The systems are either discrete or are discretized by some approximation procedure, so that the equations of motion involve a finite number of generalized coordinates. Both conservative and nonconservative loads are considered, with emphasis on cases of multiple independent loading parameters. Stability is investigated dynamically from the motion about the equilibrium state of interest. This point of view leads to a unified presentation of vibration and stability concepts. The presentation utilizes characteristic curves and stability boundaries. Characteristic curves are plots of a loading parameter versus vibration frequencies (squared). From these curves, one can determine the stability behavior of the system. If there are several independent loading parameters, stability boundaries are formed by the locus of critical loading combinations in the loading space. With two independent loads, for example, the stability boundary (or interaction curve) divides the loading plane into regions of stability and instability. In this book, properties of characteristic curves and stability boundaries are examined for various classes of loading conditions. The first chapter reviews definitions and results in matrix theory. It is followed by a description of stability concepts. Lyapunov's definitions of stability and asymptotic stability are presented. Secondorder, linear, differential equations, which have the form of the equations of motion for the systems analyzed in this book, are discussed, and the Routh-Hurwitz criterion is described. Chapters 3-6
Combustion mechanism of liquid fuel spray in a gaseous flame

Two-dimensional direct numerical simulation is applied to spray flames stabilized in a laminar counterflow, and the detailed behavior is studied in terms of the droplet group combustion. The stretch ratio of the laminar counterflow is 40 l/s. n-decane (C10H22) is used as a liquid spray fuel, and a one-step global reaction is employed for the combustion reaction model. The results show that with increasing the issued liquid fuel mass fraction, two types of spray combustion appear in front of and inside the high gaseous temperature region, i.e., “premixed-like combustion” and “diffusion-like combustion,” respectively. A droplet group combustion behavior is observed in the diffusion-like combustion region. This diffusion-like combustion, however, disappears when the issued droplet size becomes small, because the droplets complete their evaporation before entering into the high gaseous temperature region. The droplet group combustion tends to reduce the gaseous temperature. This is caused mainly by the suppre.
Performance analysis of Volterra kernel estimators with Gaussian inputs

The focus of this paper is on Volterra nonlinear system identification from input-output data. When the system is linear-quadratic and the input is Gaussian, closed-form expressions for the kernels were derived by Tick (1961) based on input-output cross-cumulants. However, there have been no known variance expressions for the kernel estimates. In this paper, we analyze the performance of the first- and second-order kernel estimates when the input is zero-mean white Gaussian, and the additive noise has unknown color and distribution. Closed-form variance expressions are presented and verified by simulations.
A comparison of object-based and contextual pixel-based classifications using high and medium spatial resolution images

Object-based classification has demonstrated numerous advantages over non-contextual pixel-based classification due to its capability of modelling spatial information through image segmentation. Similarly, contextual pixel-based classification can also incorporate spatial information among neighbouring pixels to improve the performance of non-contextual pixel-based classification. However, to our knowledge, no study has compared object-based approaches with contextual pixel-based approaches for image classification. In this letter, we compared an object-based approach using a segmentation algorithm embedded in eCognition with a contextual pixel-based approach using Markov random fields. The performances were evaluated with a high spatial resolution image (3 m) and a medium spatial resolution image (30 m) using various thematic and geometric accuracy indices. The results showed that the classification accuracy of the contextual pixel-based approach is higher than the object-based approach on both images, and the values of geometric indices for the two approaches are comparable.
On uniqueness classes of solutions of the first mixed problem for a quasi-linear second-order parabolic system in an unbounded domain

We study a quasi-linear parabolic system of divergence type having an energy inequality and satisfying monotonicity conditions. For such a system, the first mixed problem is considered in a cylindrical domain { t> 0 }× Ω that is unbounded with respect to the spatial variables. Generally, the initial vector function ϕ in the problem may not belong to L2(Ω). A uniqueness class close to that of Tacklind (3) is established for the solutions of this problem. Moreover, a uniqueness theorem is proved for a solution belonging to this class and having an initial vector function increasing at infinity.
Robust $M$-Estimators of Multivariate Location and Scatter

Let x, xn be a sample from an m-variate distribution which is spherically symmetric up to an affine transformation. This paper deals with the robust estimation of the location vector t and scatter matrix V by means of "M-estimators," defined as solutions of the system: Ei ul(di)(xi t) -_ 0 and n-1 Zi u2(di2)(xi t)(xi -t) = V, where di2 (xi t)'V-'(xi t). Existence and uniqueness of solutions of this system are proved under general assumptions about the functions ul and u2. Then the estimators are shown to be consistent and asymptotically normal. The breakdown bound and the influence function are calculated, showing some weaknesses of the estimates for high dimensionality. An algorithm for the numerical calculation of the estimators is described. Finally, numerical values of asymptotic variances, and Monte Carlo small-sample results are exhibited.
On a measure of information gain for regression models in survival analysis

Papers dealing with measures of predictive power in survival analysis have seen their independence of censoring, or their estimates being unbiased under censoring, as the most important property. We argue that this property has been wrongly understood. Discussing the so-called measure of information gain, we point out that we cannot have unbiased estimates if all values, greater than a given time τ, are censored. This is due to the fact that censoring before τ has a different effect than censoring after τ. Such τ is often introduced by design of a study. Independence can only be achieved under the assumption of the model being valid after τ, which is impossible to verify. But if one is willing to make such an assumption, we suggest using multiple imputation to obtain a consistent estimate. We further show that censoring has different effects on the estimation of the measure for the Cox model than for parametric models, and we discuss them separately. We also give some warnings about the usage of the measure, especially when it comes to comparing essentially different models.