Miracle-dz/UniFAR-FTUs huggingface dataset:
Biases in Thorpe-Scale Estimates of Turbulence Dissipation. Part II: Energetics Arguments and Turbulence Simulations

AbstractThis paper uses the energetics framework developed by Scotti and White to provide a critical assessment of the widely used Thorpe-scale method, which is used to estimate dissipation and mixing rates in stratified turbulent flows from density measurements along vertical profiles. This study shows that the relevant displacement scale in general is not the rms value of the Thorpe displacement. Rather, the displacement field must be Reynolds decomposed to separate the mean from the turbulent component, and it is the turbulent component that ought to be used to diagnose mixing and dissipation. In general, the energetics of mixing in an overall stably stratified flow involves potentially complex exchanges among the available potential energy and kinetic energy associated with the mean and turbulent components of the flow. The author considers two limiting cases: shear-driven mixing, where mixing comes at the expense of the mean kinetic energy of the flow, and convective-driven mixing, which taps the ava.
Four X-ray-selected cataclysmic variables in the galactic plane

Quatre sources RX ont ete identifiees avec des etoiles variables cataclysmiques faibles a partir du survey Einstein du plan galactique. Les observations RX, photometriques, et spectroscopiques sont presentees. Les luminosites, distances, et taux d'accretion de ces variables sont ensuite estimes. La densite spatiale des etoiles variables cataclysmiques est egalement estimee sur la base de l'identification d'au-moins 5 variables cataclysmiques dans un echantillon complet de 39 sources RX du survey de l'hemisphere sud.
Force Control of an Electrohydraulic Actuator Using a Fractional‐Order Controller

This paper presents an application of fractional‐order control to industrial electrohydraulics. An optimization based frequency domain approach is used to obtain a fractional‐order proportional‐integral controller for force control of an electrohydraulic actuator. The controller is designed to have a feature of robustness to gain variations with the step responses exhibiting an iso‐damping property. In practice, the gain variations are due to the changes in the environment or the load's force interacting with the actuator. Results of real life experiments demonstrate the effectiveness of the controller.
The milliarcsecond structure of a complete sample of radio sources. II: First-epoch maps at 5 GHz

VLBI observations of the compact radio structure in a sample of 65 powerful extragalactic radio sources are presented. The sources are classified as very compact, compact, asymmetric, compact double, irregular flat-spectrum, compact steep-spectrum, and lobe-dominated. Two different types of compact double source are identified. One-sided jets are found to be common features in AGN. Compact, optically thick cores are found in all objects except compact S doubles and a few steep-spectrum compact objects. No two-sided jet has yet been found in an AGN. The nuclear jets lie on the same side of the core as the large-scale jets. The nuclear jets are fairly highly polarized, with polarizations typically in the range of 1-5 percent. Superluminal motion is common in AGN and is found in all classes of object except the compact S double objects. 150 references.
Analytical description of the breakup of liquid jets

A viscous or inviscid cylindrical jet with surface tension in a surrounding medium of negligible density tends to pinch owing to the mechanism of capillary instability. We construct similarity solutions which describe this phenomenon as a critical time is encountered, for three distinct cases: (i) inviscid jets governed by the Euler equations, (ii) highly viscous jets governed by the Stokes equations, and (iii) viscous jets governed by the Navier-Stokes equations. We look for singular solutions of the governing equations directly rather than by analysis of simplified models arising from slender-jet theories. For Stokes jets implicitly defined closed-form solutions are constructed which allow the scaling exponents to be fixed. Navier-Stokes pinching solutions follow rationally from the Stokes ones by bringing unsteady and nonlinear terms into the momentum equations to leading order. This balance fixes a set of universal scaling functions for the phenomenon. Finally we show how the pinching solutions can be used to provide an analytical description of the dynamics beyond breakup.
On Maxentropic Reconstruction of Countable Markov Chains and Matrix Scaling Problems

Using the Maximum Entropy Principle we consider maxentropic reconstruction of some countable Markov chains with given common steady‐state probabilities. The probability transition matrix is obtained from the knowledge of the expected values of some random variables. For this, we consider the problem as an entropy optimization problem with linear constraints, which we solve by the geometric programming method. In the same way, we derive a method for solving a matrix scaling problem, namely maxentropic reconstruction of some nonnegative matrix with fixed row‐column sums.
A molecular dynamics simulation study of the orientationally disordered phase of sulphur hexafluoride

The orientationally disordered phase of sulphur hexafluoride at 150K has been studied here using the molecular dynamics simulation technique, with particular emphasis placed on the origin and nature of the orientational disorder. A model involving the frustration of two competing intermolecular interactions that had been proposed previously has been shown to be a good description of the origin of the disorder through calculations that have given information concerning the correlations between the orientations of neighbouring molecules. It has also been shown that the disorder is dynamic rather than static in nature, and features of the molecular motion that are related to this dynamic disorder have been identified. It is suggested that some of the features of orientationally disordered crystals that have been studied might be observed experimentally in a coherent neutron scattering study, and some preliminary calculations of S(Q) are reported.
Rigid spaces and the AR-Property

A rigid space is a topological vector space whose endomorphisms are all simply scalar multiples of the identity. A rigid space can be constructed so as to admit compact operators [14]. This paper proves that the rigid space admitting compact operators constructed in [14] can be modiﬁed to be an $AR$ , and hence is homeomorphic to the Hilbert space $l_{2}$ .
PREPARATION AND MAGNETORHEOLOGICAL CHARACTERIZATION OF CI/PVB CORE/SHELL PARTICLE SUSPENDED MR FLUIDS

Hybrid magnetic particles of carbonyl iron (CI) /poly(vinyl butyral) (PVB) with core/shell microstructure (CI-PVB) were prepared in order to enhance the dispersion stability of the magnetorheological (MR) fluids. Since the composite particles of CI-PVB have a lower density than that of the pristine CI particles, they are regarded to improve the sedimentation problem of magnetic particles in the MR fluid when the particles are dispersed in a mineral oil and to make easy redispersion after caking. The PVB coating layers were found to play an important role in the steric repulsion between the relatively large CI particles. Morphology and composition of the CI-PVB particles were observed via SEM and TGA, respectively. Flow properties of both CI and CI-PVB based MR fluids were examined via a rotational rheometer in parallel plate geometry equipped with a magnetic field supplier.
궁금 의미론(Inquisitive Semantics)

This paper aims to explicate the newly developed framework of inquisitive semantics (Groenendijk and Roelofsen (2011) and further to argue that my information structure-based analysis of contrastive focused alternative questions (Lee 2003) can be complementarily combined with the new theory for some improvement. My analysis strikingly coincides with the inquisitive semantics-based analysis (Pruitt and Roelofsen(2011). Inquisitive semantics is a semantic theory that views meaning as a proposal to choose from two or more possible alternatives for the common ground, unlike Grice"s (1975) informativeness-based pragmatic theory. An alternative question in English (in Korean as well) involves a contrastive focus on immediately relevant alternative items together with the intonation of a rise↑for the first disjunct and fall↓for the second disjunct. The fall compositionally closes the set of alternatives, giving rise to the exclusive stengthening effect semantically. By incorporating the analysis done for contrastive focus phenomena the new theory can be more effective and widely influential.
THE 2014 ALMA LONG BASELINE CAMPAIGN: FIRST RESULTS FROM HIGH ANGULAR RESOLUTION OBSERVATIONS TOWARD THE HL TAU REGION

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations from the 2014 Long Baseline Campaign in dust continuum and spectral line emission from the HL Tau region. The continuum images at wavelengths of 2.9, 1.3, and 0.87 mm have unprecedented angular resolutions of 0. ″ 075 (10 AU) to 0. ″ 025 (3.5 AU), revealing an astonishing level of detail in the circumstellar disk surrounding the young solar analog HL Tau, with a pattern of bright and dark rings observed at all wavelengths. By fitting ellipses to the most distinct rings, we measure precise values for the disk inclination ( 46 &fdg; 72 ± 0 &fdg; 05 ? > ) and position angle ( + 138 &fdg; 02 ± 0 &fdg; 07 ) . > We obtain a high-fidelity image of the 1.0 mm spectral index (α), which ranges from &agr; ∼ 2.0 ? > in the optically thick central peak and two brightest rings, increasing to 2.3–3.0 in the dark rings. The dark rings are not devoid of emission, and we estimate a grain emissivity index of 0.8 for the innermost dark ring and lower for subsequent dark rings, consistent with some degree of grain growth and evolution. Additional clues that the rings arise from planet formation include an increase in their central offsets with radius and the presence of numerous orbital resonances. At a resolution of 35 AU, we resolve the molecular component of the disk in HCO+ (1-0) which exhibits a pattern over LSR velocities from 2–12 km s−1 consistent with Keplerian motion around a ∼1.3 M ⊙ ? > star, although complicated by absorption at low blueshifted velocities. We also serendipitously detect and resolve the nearby protostars XZ Tau (A/B) and LkHα358 at 2.9 mm.
Markov switching models: An application to roadway safety

In this research, two-state Markov switching models are proposed to study accident frequencies and severities. These models assume that there are two unobserved states of roadway safety, and that roadway entities (e.g., roadway segments) can switch between these states over time. The states are distinct, in the sense that in the different states accident frequencies or severities are generated by separate processes (e.g., Poisson, negative binomial, multinomial logit). Bayesian inference methods and Markov Chain Monte Carlo (MCMC) simulations are used for estimation of Markov switching models. To demonstrate the applicability of the approach, we conduct the following three studies. In the first study, two-state Markov switching count data models are considered as an alternative to zero-inflated models for annual accident frequencies, in order to account for preponderance of zeros typically observed in accident frequency data. In the second study, two-state Markov switching Poisson model and two-state Markov switching negative binomial model are estimated using weekly accident frequencies on selected Indiana interstate highway segments over a five-year time period. In the third study, two-state Markov switching multinomial logit models are estimated for severity outcomes of accidents occurring on Indiana roads over a four-year time period. One of the most important results found in each of the three studies, is that in each case the estimated Markov switching models are strongly favored by roadway safety data and result in a superior statistical fit, as compared to the corresponding standard (non-switching) models.
Low‐order multi‐rate linear time‐invariant decentralized trackers using the new observer‐based sub‐optimal method for unknown sampled‐data nonlinear time‐delay system with closed‐loop decoupling

This paper presents the low‐order multi‐rate linear time‐invariant decentralized trackers using the new observer‐based sub‐optimal method for a class of unknown sampled‐data nonlinear time‐delay system with closed‐loop decoupling. For the unknown sampled‐data nonlinear time‐delay system, we assume that the inner time delay is clearly known. Under this prerequisite, the appropriate (low‐) order decentralized linear observer for the unknown sampled‐data nonlinear system is determined by the off‐line observer/Kalman filter identification (OKID) method with artificial delay input and actual delay output. Then, the above observer has been further improved based on the proposed new observer‐based sub‐optimal approach. Sequentially, the decentralized tracker with the high gain property is proposed, so that the closed‐loop system has the decoupling property. The proposed approach constructs complete mathematics method including the concept of optimal control theory and state‐matching digital redesign technique and is quite useful for the complicated interconnected large‐scale sampled‐data nonlinear time‐delay system with unknown system equation. Copyright © 2010 John Wiley & Sons, Ltd.
Observations of the effect of lower hybrid waves on ELM behaviour in EAST

Dedicated experiments focusing on the influence of lower hybrid waves (LHWs) on edge-localized modes (ELMs) were first performed during the 2012 experimental campaign of EAST, via modulating the input power of LHWs in the high-confinement-mode (H-mode) plasma mainly sustained by ion cyclotron resonant heating. Natural ELMs are effectively mitigated (ELM frequency increases, while its intensity decreases dramatically) as the LHW is applied, observed over a fairly wide range of plasma current or edge safety factor. By scanning the modulation frequency (fm) of LHW injected power in a target plasma dominated by the so-called small ELMs, we conclude that large ELMs with markedly larger amplitudes and lower frequencies are reproduced at low modulation frequencies (fm < 100 Hz). Analysis of the evolution of edge extreme ultraviolet radiation signals further indicates that plasma fluctuations at the pedestal region indistinctively respond to rapid modulation (fm ⩾ 100 Hz) of LHW injected power. This is proposed as the mechanism responsible for the observed fm dependence of the mitigation effect induced by LHWs on large ELMs. In addition, a critical threshold of LHW input power PLHW is estimated as , beyond which the impact of applied LHWs on ELM behaviours can be achieved. Finally, Langmuir probe measurements suggest that, rather than the concentration of free energy into a narrowband quasi-coherent precursor commonly observed growing until the ELM crash, the continuous development of broadband turbulence during the ELM-absent phase with the application of LHWs might contribute to the avoidance of ELM crashes. These results present new insights into existing experiments, and also provide some foundations and references for the next-step research about exploring in more depth and improving this new attractive method to effectively control the ELM-induced very large transient heat and particle flux.
Improvement of vertical light extraction from GaN‐based LEDs on moth‐eye patterned sapphire substrates

A newly developed moth‐eye patterned sapphire substrate (MPSS) technology increased light extraction efficiency (LEE) in the vertical direction in nitride‐based blue light emitting diodes (LEDs). MPSS is characterized by a submicron‐scale periodical structure that exerts the Bragg diffraction effect at the interface between gallium nitride (GaN) and sapphire. Through simulations and experiments, it was revealed that emphasis of the diffraction effect by optimizing the MPSS structure enhanced vertical emission from LEDs. As a result, resin‐encapsulated, large‐sized LEDs on MPSS with a large diffraction effect achieved a high LEE of 0.76 that was comparable to that of commercially available thin‐film LEDs.
Effect of Thermal Buoyancy on the Two-Dimensional Upward Flow and Heat Transfer Around a Square Cylinder

The effect of aiding/opposing buoyancy on the two-dimensional upward flow and heat transfer around a heated/cooled cylinder of square cross section is studied in this work. The finite-volume-based commercial computational fluid dynamics (CFD) software FLUENT is used for the numerical simulation. The influence of aiding/opposing buoyancy is studied for Reynolds and Richardson numbers ranges of 50 to 150 and –1 to 1, respectively, and the blockage parameters of 2% and 25%. The flow exhibits unsteady periodic characteristics in the chosen range of Reynolds numbers (except for Reynolds number of 50 and blockage parameter of 25%) for the forced convective cases (Richardson number of 0). However, the vortex shedding is observed to stop completely at some critical value of Richardson number for a particular Reynolds number, below which the shedding of vortices into the stream is quite prominent. Representative streamlines and isotherm patterns for different blockage parameters are systematically presented and discussed. The critical Richardson and average Nusselt numbers are plotted against the Reynolds and Richardson numbers, respectively, to elucidate the role of thermal buoyancy on flow and heat transfer characteristics. It is observed that the vortex shedding frequency (Strouhal number) increases with increased heating and suddenly reduces to zero at the critical Richardson number. The critical Richardson number is again found to increase with Reynolds number for a particular blockage ratio, and the higher the blockage ratio, the less is the critical Richardson number. The results obtained from the commercial solver are extensively validated with the available numerical results in the literature and an excellent agreement is observed.
Application of Total Least Squares for Spatial Point Process Analysis

The total-least-squares approach is a relatively new adjustment method of estimating parameters in linear models that include error in all variables. Specifically, given an overdetermined set of linear equations y≈Aξ where y is the observation vector, A is a positive defined data matrix, and ξ is the vector of unknown parameters, the total-least-squares problem is concerned with estimating ξ providing that the number of observations n is larger than the number of parameters to be estimated and given that both the observation vector y and the data matrix A are subjected to errors and need to be adjusted. This model is different from the classical least-squares model where only the observation vector y is subjected to errors. This paper starts with a brief summary of the least-squares approach and then explains how one can modify the approach to include error in all variables using the generalized least-squares technique. Then the total-least-squares problem is presented along with its formulas and the proc.
Numerical analysis of the Poiseuille and thermal transpiration flows between two parallel plates on the basis of the Boltzmann equation for hard‐sphere molecules

The Poiseuille and thermal transpiration flows of a rarefied gas between two parallel plates are investigated on the basis of the linearized Boltzmann equation for hard‐sphere molecules and diffuse reflection boundary condition. The velocity distribution functions of the gas molecules as well as the gas velocity and heat flow profiles and mass fluxes are obtained for the whole range of the Knudsen number with good accuracy by the numerical method recently developed by the authors.
Flood routing in long channels: Alleviation of inconsistency and discharge dip in Muskingum‐based models

Abstract The Muskingum parameters are often expressed as a function of discharge and channel properties (Cunge, 1969; Chow et al., 1988) by referring to the coefficients of the advection‐diffusion (A‐D) equation or the equivalent parabolicized Saint Venant equation. As extensively investigated in this paper by Taylor series expansion, the Muskingum model and its variants are found tangibly inconsistent to the A‐D equation. In addition, these Muskingum‐based models experience the effect of negative outflows, i.e., the well‐known dip phenomenon. To avoid these problems, which are both present in the conventional routing procedure, this paper introduces an extra term to the traditional Muskingum storage function, that is then linked to Gill's concept of initial storage. Through this technique, not only the dip phenomenon but also the model inconsistency can be alleviated, and a fairly satisfactory outflow prediction can thereby be achieved. A proper time to employ the extra term is sought by a convolution integral which is a result of the Laplace transformation applied to the Muskingum model. It also represents the analytical expression of outflow discharge. The convolution integral enables us to trace the origin of discharge dip and quantify the shape variation of outflow hydrographs. With the convolution integral, compact models for computing the maximum flow dip, “dip”, and its occurrence time, tc , are also offered in this study. As a concluding example, routings by the traditional Muskingum model, Gill's procedure, and the newly developed algorithms having the extra term are performed in a long channel reach of 90 kilometers to test the robustness of each model.
Multilevel Factor Analyses of Family Data From the Hawai’i Family Study of Cognition

In this study, we reanalyzed the classic Hawai’i Family Study of Cognition (HFSC) data using contemporary multilevel modeling techniques. We used the HFSC baseline data (N = 6,579) and reexamined the factorial structure of 16 cognitive variables using confirmatory (restricted) measurement models in an explicit sequence. These models were initially fitted using multilevel confirmatory factor analysis techniques and the invariant six-factor models with two higher order factors fit fairly well (εa < 0.08) to the total, between- and within-family data. More crucially, a model requiring metric factorial invariance proved to be a reasonable fit to the between and within matrices, and allowed the ratio of the between-family variation to total family variation (eta-squared) to be calculated separately for each common factor (η2: Gc = .27, Gf = .22, Gm = .15, Gs = .04, Gv = .30, and SP = .16). Higher order factors were fitted using multilevel structural equation modeling techniques and these suggested a reasonable two-factor solution with unequal family impacts. These results suggest that (a) A “G only model” does not fit the data very well, and there are many sources of individual differences in cognitive abilities; (b) the sources of the individual differences in cognition can be measured the same way between and within families; and (c) even after the unique test components are removed, cognitive differences are larger within families than between families. We consider other general multivariate family models, and we raise questions about family influences.