Miracle-dz/UniFAR-FTUs huggingface dataset:
The Zonally Averaged Circulation of the Middle Atmosphere

Abstract The steady-state, zonally averaged circulation of the middle atmosphere (15–125 km) is studied with a quasigeostrophic, numerical model that explicitly includes a self-consistent calculation of solar radiative heating due to O2 and O3 absorption, Newtonian cooling, Rayleigh friction, tropopause boundary conditions based on climatological averages, and the effects of vertically propagating planetary waves. We find the direct, radiatively driven pole-to-pole circulation at solstice is sufficient to account for the cold summer mesopause and warm isothermal winter mesosphere with associated zonal jets of realistic magnitude. The climatological heat and momentum fluxes associated with planetary wavenumber 2 have a negligible effect on the mean circulation. With planetary wavenumber 1 no steady-state solution could be obtained due to the formation of easterlies and hence critical layers in the winter mesosphere. We also find that the radiative heating associated with secondary peaks in the O3 density a.
Surjective mappings whose differential is nowhere surjective

Examples of C -mappings / : R" —> Rm , n > m > 2 , are given, with rank df{x) < s at any x 6 R" , 2 < j < m , but /(R") = Rm , for any k < (n s + 2)l(m — s + 2). Thus a weak form of Sard's theorem (if all the points in the source are critical, the image has measure zero) does not hold for mappings of low smoothness. 1. The structure of critical points and values of differentiable mappings has been studied intensively since the classical work of H. Whitney [5], [6] and M. Morse [3]. Sard's (or, better, M. Morse's-A. P. Morse's-A. Sard's) Theorem [4] claims that critical values of a sufficiently smooth mapping form a set of measure zero. Whitney's paper [5] provides examples of functions which are nonconstant on a connected set of critical points, thus showing the sharpness of the differentiability assumptions in Sard's theorem. However, the following closely related question seems to be open: Is it possible for a differentiable mapping / : R" —► Em , with rank df < m at every point, to be onto (or to have an image with a nonempty interior)? Clearly, for m = 1 , any C -function with all the points critical is a constant, so the question makes sense only for mappings into Rm, m > 2. If Sard's theorem is valid, the answer is, of course, negative. But what happens for mappings of a lower smoothness than that required in Sard's theorem? Besides its theoretical interest, this question is important in various applications. Recently it has attracted the attention of specialists in control theory [2, p. 59]. In this note, we answer this question positively, constructing highly differentiable surjective mappings /:R"-» Km with rank df < m everywhere. 2. For / : K" — Em , let us denote as £,(/) the set {x G R", ranka7(x) < s}, and let As(f) = f(J2s(f)) be the corresponding set of critical values. Define the set £ls(f) of strongly critical values as follows: Q (/) = {y e Rm/ xaxikdf(x) < s for any x G f~\y)}. While the usual Received by the editors March 30, 1989. 1980 Mathematics Subject Classification (1985 Revision). Primary 58C25, 58C27. Supported by NSF Grant DMS-8610730. ©1991 American Mathematical Society 0002-9939/91 $1.00+ $. 25 per page
Aspheric and freeform surfaces metrology with software configurable optical test system: a computerized reverse Hartmann test

Abstract. A software configurable optical test system (SCOTS) based on deflectometry was developed at the University of Arizona for rapidly, robustly, and accurately measuring precision aspheric and freeform surfaces. SCOTS uses a camera with an external stop to realize a Hartmann test in reverse. With the external camera stop as the reference, a coordinate measuring machine can be used to calibrate the SCOTS test geometry to a high accuracy. Systematic errors from the camera are carefully investigated and controlled. Camera pupil imaging aberration is removed with the external aperture stop. Imaging aberration and other inherent errors are suppressed with an N-rotation test. The performance of the SCOTS test is demonstrated with the measurement results from a 5-m-diameter Large Synoptic Survey Telescope tertiary mirror and an 8.4-m diameter Giant Magellan Telescope primary mirror. The results show that SCOTS can be used as a large-dynamic-range, high-precision, and non-null test method for precision aspheric and freeform surfaces. The SCOTS test can achieve measurement accuracy comparable to traditional interferometric tests.
Fresnel volume ray tracing

The concept of “Fresnel volume ray tracing” consists of standard ray tracing, supplemented by a computation of parameters defining the first Fresnel zones at each point of the ray. The Fresnel volume represents a 3-D spatial equivalent of the Fresnel zone that can also be called a physical ray. The shape of the Fresnel volume depends on the position of the source and the receiver, the structure between them, and the type of body wave under consideration. In addition, the shape also depends on frequency: it is narrow for a high frequency and thick for a low frequency. An efficient algorithm for Fresnel volume ray tracing, based on the paraxial ray method, is proposed. The evaluation of the parameters defining the first Fresnel zone merely consists of a simple algebraic manipulation of the elements of the ray propagator matrix. The proposed algorithm may be applied to any high‐frequency seismic body wave propagating in a laterally varying 2-D or 3-D layered structure (P, S, converted, multiply reflected, et.
High performance ultra-low speed servo system based on doubly coprime factorization and instantaneous speed observer

This paper proposes a new speed servo system for a wide speed range based on doubly coprime factorization and instantaneous speed observer. The proposed speed controller is a new two-degrees-of-freedom speed servo system considering the robust stability according to inertia variation, which is designed on the basis of doubly coprime factorization and disturbance observer. In an ultra-low speed range, a speed sensor based on a rotary encoder cannot detect a motor speed. In this paper, a speed information in a very low speed range is estimated by the proposed instantaneous speed observer which mounts the parameter identification algorithm to cancel out the estimation error caused by parameter variation. Therefore, the two-degrees-of-freedom speed servo system connecting the instantaneous speed observer regulates a motor speed robustly in a wide speed range including an ultra-low speed range, and it keeps the desired speed response for all speed reference including an ultra-low speed range.
Dendritic solidification of binary alloys with free and forced convection

Dendritic solidification with forced convection and free convection driven by contraction and thermo‐ solutal buoyancy is simulated in two‐dimensional space using a sharp‐interface model. Both pure substances and alloys are considered. The model is formulated using the finite element method and works directly with primitive variables. The coupled energy‐ and solutal concentration‐equations, along with the Navier–Stokes equations for incompressible flow, are solved using different meshes. Temperature is solved in a fixed mesh that covers the whole domain (solid + liquid) where the solid–liquid interface is explicitly tracked using marker points. The concentration and momentum equations are solved in the liquid region using an adaptive mesh of triangular elements that conforms to the interface. The velocity boundary conditions are applied directly on the interface. The model is validated using a series of problems that have analytical, experimental and numerical results. Four simulations are presented: (1) crystal growth of succinonitrile with thermal convection under two small undercoolings; (2) dendritic growth into an undercooled pure melt with a uniform forced flow; (3) equiaxial dendritic growth of a pure substance and an alloy with contraction‐induced convection; and (4) directional solidification of Pb–0.2 wt% Sb alloy with convection driven by the combined action of contraction, thermal and solutal buoyancy. Some of the simulation results are compared to those reported using other methods including the phase‐field method; others are new. In each case, the effects of convection on dendritic solidification are analysed. Copyright © 2005 John Wiley & Sons, Ltd.
Role of membrane viscosity in the orientation and deformation of a spherical capsule suspended in shear flow

Red blood cells or artificial vesicles may be conveniently represented by capsules, i.e. liquid droplets surrounded by deformable membranes. The aim of this paper is to assess the importance of viscoelastic properties of the membrane on the motion of a capsule freely suspended in a viscous liquid subjected to shear flow. A regular perturbation solution of the general problem is obtained when the particle is initially spherical and undergoing small deformations. With a purely viscous membrane (infinite relaxation time) the capsule deforms into an ellipsoid and has a continuous flipping motion. When the membrane relaxation time is of the same order as the shear time, the particle reaches a steady ellipsoidal shape which is oriented with respect to streamlines at an angle that varies between 45° and 0°, and decreases with increasing shear rates. Furthermore it is predicted that the deformation reaches a maximum value, which is consistent with experimental observations of red blood cells.
Optimization of Lateral Interlock Protection for Thermal Power Units

According to the Twenty-Five Key Requirements for Preventing Electric Power Production Accidents, the protection of important capital and auxiliary equipment should adopt the “Two Out of Three” logic judgment method, and the protection signal should follow the whole process from the sampling point to the input module. The principle of relative independence is that the number of measuring points is insufficient due to system reasons, and measures to prevent disoperation should be taken. Considering that a coal-fired power plant’s third-phase engineering steam turbine, boiler, and generator lateral protection signals are single-point design and do not meet the requirements of countermeasures, the abnormality of a single circuit of the protection signal will cause abnormal protection actions and affect the safe and stable operation of the unit. Therefore, the original control strategy is systematically optimized by adopting the “Two Out of Three” logic and successfully passes the ETS, DEH, FSSS, and lateral interlock protection tests. The result provides a reference for equipment malfunction in the operation of the same type of units.
Research on Power-Frequency Overvoltages of 220 kV Offshore Cable Transmission System in Liaoning Province

Since power-frequency overvoltages can influence the safe operation of the submarine cable transmission system greatly, it is indispensable to calculate the overvoltages that may occur during actual situations. In this study, the power-frequency overvoltages of the offshore oil-gas field group’s submarine cable transmission system are calculated through PSCAD/EMTDC. Among the different conditions considered, the maximum power-frequency overvoltage is 1.134p. u. , which occurs in the case of single-phase fault earthing at the cable joint in L4. The result fulfills the limit of relevant regulations for the 220 kV transmission system, indicating that the submarine cable transmission system can operate safely and effectively, which can provide important guiding significance for the construction and operation of the system.
Real-time buildup dynamics of additive dissipative soliton in mode-locked fiber lasers

Multi-soliton operation is a universal phenomenon in mode-locked lasers, which is generally considered to be generated from pulse splitting or pulse shaping of dispersive waves. Here, we experimentally unveiled the formation dynamics of additive dissipative soliton (ADS) in mode-locked fiber lasers by means of the time stretched technique. Two distinct evolution ways can be observed during the ADS formation process. One way is pulse splitting which corresponds to the soliton molecules with relatively close separation, while the other one is generated from background noise which corresponds to multi-solitons with loose separation. Due to the environmental perturbation, the former process undergoes transient quasi-periodic dissipative soliton explosion before the soliton molecules are stable and the latter way may suffer transient standstill before the formation of additive soliton. These findings could provide some assistance for further enhancing the comprehension of the buildup of multiple soliton and soliton molecules in dissipative systems.
Analysis of the Influence of Distributed Generation on Distribution Network Voltage

This paper introduces the development and application background of distributed generation and analyzes its technical characteristics. According to the relationship between distributed generation and traditional distribution networks, the models of different types of distributed generation are equivalent to PQ, PI, PV, and PQ (V) nodes. Besides, this paper analyzes the impact of distributed generation on the voltage of the distribution network from the perspective of position and capacity. It points out the direction for further research.
LISC Catalog of Star Clusters. II. High Galactic Latitude Open Clusters in Gaia EDR3

It is well known that there are few open clusters (OCs) in the high-latitude region of the Milky Way galaxy, because most star formation takes place in the thin disk. It is therefore crucial to look for high Galactic latitude OCs, in order to understand OCs and the Galactic parts outside the plane well. This work looks for high Galactic latitude OCs in Gaia Early Data Release 3, and determines their basic parameters from color–magnitude diagrams (CMDs) if the main sequence is included in CMDs. The friend-of-friend method is applied to the determination of the membership of stars. Star groups with more than 20 bright (G < 18 mag) stars are taken as OC candidates, and these candidates are finally verified by the observed CMDs including stars fainter than 18 mag in the G band. After crossmatching with previous catalogs, 56 new OC candidates are found in the high Galactic latitude region with ∣b∣ ≥ 25°, in which 35 have somewhat clear CMDs and are suggested as newly discovered OCs. Finally, eight of the new OCs are confirmed again by the pyUPMASK technique. The new sample increases the total number of known high Galactic latitude OC candidates significantly. The distance modulus, color excess, metallicity, age, and binary fraction of 35 newly discovered OCs are determined by fitting their observed CMDs to the ASPS stellar population models. All the results are included in the new star cluster catalog, LISC, as its second part (LISC II).
Relation between Long-term Activity and Luminosity of the Pre- and Post-novae CT Ser and V446 Her

We show a relation of the pre- and post-nova activity of CT Ser (nova 1948) and V446 Her (nova 1960), known to have remarkably similar orbital periods P orb. We use both photographic and CCD photometric observations. Post-nova CT Ser shows a nova-like high-state activity with only a slight decrease of absolute magnitude M opt. In the interpretation, its M opt is above the region of the thermal-viscous instability (TVI) regime, so the disk is ionized out to its outer rim, similarly to before its classical nova (CN) outburst. On the contrary, V446 Her started its CN outburst from the TVI regime. Extensive changes in activity type in years after CN outburst were observed in V446 Her. The features consistent with the dwarf-nova outbursts appeared at most three decades after the end of the CN outburst. It suggests that its disk transitioned into the TVI region in that it was before its CN outburst. The pre-nova and post-nova states of activity did not change significantly for a given system, except for several decades after the CN outburst. Even pre-novae and post-novae with mutually similar P orb, hence secondary star (donor) spectral types and dimensions and disk radii, can show largely discrepant M opt and disk states in the similar epochs (several decades) surrounding the CN outburst.
Robust Inference for Misspecified Models Conditional on Covariates

Following the work by White (1980ab; 1982) it is common in empirical work in economics to report standard errors that are robust against general misspecification. In a regression setting these standard errors are valid for the parameter that in the population minimizes the squared difference between the conditional expectation and the linear approximation, averaged over the population distribution of the covariates. In nonlinear settings a similar interpretation applies. In this note we discuss an alternative parameter that corresponds to the approximation to the conditional expectation based on minimization of the squared difference averaged over the sample, rather than the population, distribution of a subset of the variables. We argue that in some cases this may be a more interesting parameter. We derive the asymptotic variance for this parameter, generally smaller than the White robust variance, and we propose a consistent estimator for the asymptotic variance.
Mercury's core - The effect of obliquity on the spin-orbit constraints

In an earlier paper by the authors (Peale and Boss, 1977), rather severe constraints were placed on the properties of a Mercurian liquid core and certain other dynamical characteristics of the planet for consistency with Mercury's escape from the spin-orbit resonance with the spin angular velocity equal to twice the orbital mean motion. One assumption under which these constraints were established was that the obliquity θ ≈ 0 at the time of resonance passage. Here we show that for θ ≠ 0, Mercury can easily escape the spin resonance with a large core of low viscosity, and all constraints established for resonance passage for θ = 0 would vanish. However, the same effect which so drastically reduces the probability of capture into the 2n resonance also would have reduced θ to negligibly small values long before the 2n resonance was reached. Thus Mercury most likely passed through ΨM = 2n with θ ≈ 0, and hence the previously established constraints of the kinematic viscosity ν ≈ 0.01 and the tidal dissipation factor Q ≲ 100 for a laminar core-mantle boundary layer and the constraints on critical Reynolds number Rc ≳ 500, tidal Q ≲ 40, and moment differences (B - A)/C ≲ 10−5 for a turbulent boundary layer are still applicable for any core capable of dynamo generation of a magnetic field.
THE ORIGIN OF ASTEROID 101955 (1999 RQ36)

Near-Earth asteroid (NEA) 101955 (1999 RQ36; henceforth RQ36) is especially accessible to spacecraft and is the primary target of NASA's OSIRIS-REx sample return mission; it is also a potentially hazardous asteroid. We combine dynamical and spectral information to identify the most likely main-belt origin of RQ36 and we conclude that it is the Polana family, located at a semimajor axis of about 2.42 AU. We also conclude that the Polana family may be the most important inner-belt source of low-albedo NEAs. These conclusions are based on the following results. (1) Dynamical evidence strongly favors an inner-belt, low-inclination (2.15 AU < a < 2.5 AU and i < 10°) origin, suggesting the ν6 resonance as the preferred (95% probability) delivery route. (2) This region is dominated by the Nysa and Polana families. (3) The Polana family is characterized by low albedos and B-class spectra or colors, the same albedo and spectral class as RQ36. (4) The Sloan Digital Sky Survey colors show that the Polana family is the branch of the Nysa–Polana complex that extends toward the ν6 resonance; furthermore, the Polana family has delivered objects of the size of RQ36 and larger into the ν6 resonance. (5) A quantitative comparison of visible and near-infrared spectra does not yield a unique match for RQ36; however, it is consistent with a compositional link between RQ36 and the Polana family.
Simulation study of item bias detection with restricted factor analysis

Restricted factor analysis (RFA) can be used to detect item bias (also called differential item functioning). In the RFA method of item bias detection, the common factor model serves as an item response model, but group membership is also included in the model. Two simulation studies are reported, both showing that the RFA method detects bias in 7‐point scale items very well, especially when the sample size is large, the mean trait difference between groups is small, the group sizes are equal, and the amount of bias is large. The first study further shows that the RFA method detects bias in dichotomous items at least as well as an established method based on the one‐parameter logistic item response model. The second study concerns various procedures to evaluate the significance of two‐item bias indices provided by the RFA method. The results indicate that the RFA method performs best when it is used in an iterative procedure.
Surveying auditory space using vowel formant data

Recent research has suggested that vowel category learning and the perceptual magnet effect are the natural consequences of auditory neural map formation [F. H. Guenther and M. N. Gjaja, J. Acoust. Soc. Am. 100, 1111–1121 (1996)]. As these effects are language specific, the organization of the perceptual map crucially is dependent on the input received during learning. Guenther and Gjaja implemented a working model of a self‐organizing neural map to show that, given input from Gaussian distributions around vowel category centers, unsupervised training leads to a warping of the perceptual space toward the category centers. This work replicates Guenther and Gjaja’s results and provides a more realistic test of the model by using real vowel formant data instead of idealized distributions. Single and multiple male talker vowel data were used to train auditory neural maps. Single‐talker simulations resulted in map organization similar to Guenther and Gjaja’s results. However, no clear vowel category clusters e.
Design and application of an information fusion control system

This paper presents an information fusion control system designed based on a reformulation of traditional PID control methods. The purpose of the study was to integrate multiple information resources in order to achieve a better control performance in terms of system dynamics and statistic responses. An information fusion control was developed by turning the original control problem into a ‘fusion estimation’ problem. Specifically, the Choquet fuzzy integral was implemented to fuse different information resources for improving the generalization and efficiency of the PID control. Tracking and adaptation of the information fusion control system were analysed via control of a simulated mechanical system. The simulation results show that the proposed information fusion control was effective.