Miracle-dz/UniFAR-FTUs huggingface dataset:
Climatology of polar lows over the Norwegian and Barents Seas

The large-scale flow pattern during the formation of polar lows over the Norwegian and Barents Seas has been studied. The results indicate that in most cases a strong northerly airflow is located close to the east coast of Greenland. The geographical distribution of polar lows suggests a division of the events into two groups, a western group consisting of the lows first observed west of 5°E, and an eastern group consisting of those first observed east of the same longitude. Mean maps for each group were constructed for the winter season, and they show large anomalies. The strongest negative anomaly in the 500 mb height is found over the Norwegian Sea. The anomaly is −230 gpm for the events west of 5°E, and −179 gpm for those east of 5°E. For polar lows developing in the western sector, the largest positive anomaly, + 198 gpm, is associated with the Azores High. When polar lows are formed in the eastern sector, the strongest positive anomaly is associated with the ridge over Greenland; the cold air in the strong northerly flow east of Greenland is then up to 8°C colder than normal. The location of this cold anomaly gives a westward tilt of the anomaly pattern with height. DOI: 10.1111/j.1600-0870.1988. tb00345.x
X-33 Hypersonic Aerodynamic Characteristics

Lockheed Martin Skunk works, under a cooperative agreement with NASA, will build and fly the X-33, a half-scale prototype of a rocket-based, single-stage-to-orbit (SSTO), reusable launch vehicle (RLV). A 0.007-scale model of the X-33 604B0002G configuration was tested in four hypersonic facilities at the NASA Langley Research Center to examine vehicle stability and control characteristics and to populate an aerodynamic flight database in the hypersonic regime. The vehicle was found to be longitudinally controllable with less than half of the total body flap deflection capability across the angle of attack range at both Mach 6 and Mach 10. At these Mach numbers, the vehicle also was shown to be longitudinally stable or neutrally stable for typical (greater than 20 degrees) hypersonic flight attitudes. This configuratin was directionally unstable and the use of reaction control jets (RCS) will be necessary to control the vehicle at high angles of attack in the hypersonic flight regime. Mach number and real gas effects on longitudinal aerodynamics were shown to be small relative to X-33 control authority.
Playing checkers: detection and eye–hand coordination in simulated prosthetic vision

In order to assess the potential for visual inspection and eye–hand coordination without tactile feedback under conditions that may be available to future retinal prosthesis wearers, we studied the ability of sighted individuals to act upon pixelized visual information at very low resolution, equivalent to 20/2400 visual acuity. Live images from a head-mounted camera were low-pass filtered and presented in a raster of 6 × 10 circular Gaussian dots. Subjects could either freely move their gaze across the raster (free-viewing condition) or the raster position was locked to the subject's gaze by means of video-based pupil tracking (gaze-locked condition). Four normally sighted and one severely visually impaired subject with moderate nystagmus participated in a series of four experiments. Subjects' task was to count 1 to 16 white fields randomly distributed across an otherwise black checkerboard (counting task) or to place a black checker on each of the white fields (placing task). We found that all subjects were capable of learning both tasks after varying amounts of practice, both in the free-viewing and in the gaze-locked conditions. Normally sighted subjects all reached very similar performance levels independent of the condition. The practiced performance level of the visually impaired subject in the free-viewing condition was indistinguishable from that of the normally sighted subjects, but required approximately twice the amount of time to place checkers in the gaze-locked condition; this difference is most likely attributable to this subject's nystagmus. Thus, if early retinal prosthesis wearers can achieve crude form vision, then on the basis of these results they too should be able to perform simple eye–hand coordination tasks without tactile feedback.
New method of deriving local energy- and momentum-conserving Maxwell-collisionless drift-kinetic and gyrokinetic theories: basic theory

In this paper we describe a relatively simple and transparent method of obtaining collisionless drift-kinetic, gyrokinetic and more general theories, including local charge, energy and momentum conservation laws. An important feature of the new formalism is, contrary to present-day theories, the exact gauge invariance, thus avoiding certain inconsistencies. The present paper starts with the introduction and proof of the correctness of a Lagrangian for combined Maxwell-kinetic theories in general coordinates as concerns the particle motion. The kinetic part of it is formulated in Eulerian form by means of the equations of motion in the form of Hamilton–Jacobi's equation, used only as a tool, and Dirac's constraint theory. Charge and current densities automatically distinguish between ‘particle-like’ (guiding-centre), polarization and magnetization contributions. This formalism is applied to averaging coordinates derived by a method similar to Kruskal's. Certain properties of the averaging coordinates, according to the basic requirements imposed on them, can be used to obtain a gyroangle independent Lagrangian, from which one can obtain a Lagrangian for the combined Maxwell-kinetic theories in a reduced phase space that is applicable to situations in which one is not interested in the dependence on some kind of gyroangle describing the gyromotion, whose treatment can, however, easily be added. The basic perturbation theory, which aims at obtaining averaging phase-space coordinates, is done solely within the Kruskal formalism in which only the electric and magnetic fields appear, but not the corresponding potentials. This formalism provides, in particular, information about the allowed amplitudes of fluctuations. The results are later used to obtain approximate expressions for the Lagrange functions in the drift-kinetic and the gyrokinetic ordering. For the definition of certain approximations to the exact Lagrangian the central principle is the exact gauge invariance. The terms of the zeroth and first orders needed for such an approximation are given. For the drift-kinetic ordering Littlejohn's Lagrangian is readily rederived and hence the drift-kinetic theory as obtained and investigated by the present authors in some previous work. Conservation laws and their mathematical structures corresponding to the gyroangle-independent Lagrangian are obtained in a following paper. There, in particular, a detailed description of how to obtain variations of gyroangle averaged quantities in the reduced phase space is given, and it is explained how these variations are used in a modified form of Noether's theory which observes exact gauge invariance.
MHD simulation of the transpolar potential after a solar‐wind density pulse

On 10 January 1997 an isolated solar wind density pulse, with other interplanetary parameters remaining steady, led to an enhanced transpolar potential (ΦTP) that is not predicted by either the Weimer or Siscoe‐Hill models. However, a magnetohydrodynamic simulation of the magnetosphere's response to a sudden increase in solar wind density does predict an ΦTP increase consistent with satellite observations during the 10 January 1997 event. The response is transient, decaying after several tens of minutes toward an equilibrium that is close to the original potential. The simulated ΦTP increase derives from erosion of the dayside magnetopause and transport of newly opened flux across the polar cap. The exponential decay of ΦTP results from inductance in the magnetosphere‐ionosphere circuit.
Reliable thin film encapsulation for organic light emitting diodes grown by low-temperature atomic layer deposition

We report on highly efficient gas diffusion barriers for organic light emitting diodes (OLEDs). Nanolaminate (NL) structures composed of alternating Al2O3 and ZrO2 sublayers grown by atomic layer deposition at 80 °C are used to realize long-term stable OLED devices. While the brightness of phosphorescent p-i-n OLEDs sealed by a single Al2O3 layer drops to 85% of the initial luminance of 1000 cd/m2 after 1000 h of continuous operation, OLEDs encapsulated with the NL retain more than 95% of their brightness. An extrapolated device lifetime substantially in excess of 10 000 h can be achieved, clearly proving the suitability of the NLs as highly dense and reliable thin film encapsulation of sensitive organic electronic devices.
Hargreaves Equation as an All-Season Simulator of Daily FAO-56 Penman-Monteith ETo

﻿This work showed the Hargreaves equation (HG) can be modified into a highly efficient computational replacement for the FAO-56 Penman-Monteith equation and its auxiliary functions for the computation of daily reference evapotranspiration (ETo) estimation when only available data are daily temperature data. By modifying all the constants (i.e., '0.0023', '0.5' and '17.8') in HG and adding a new constant, a modified HG (HG1234) gave almost identical estimates of daily ETo as FPM, with modified coefficient of efficiency, 𝐸1 = 0.99, 𝑟2 = 1.00, and MAE of 0.00 mm/d for a weather station in Accra, Ghana. HG1234 and ten other less drastic modifications of HG were compared against FPM at simulated average wind speeds, 𝑢2, of 0.5 m/s, 2.0 m/s and 4.0 m/s for daily estimates of ETo. In general the uncalibrated HG predicted FPM with very low 𝐸1 at 𝑢2 other than the global average of 2 m/s, and the more drastic the modification of HG the higher its efficiency at simulating FPM ETo at all wind velocities. Thus although HG was not originally developed for daily ETo estimation, modifying it to HG1234 can turn it into a very efficient and much faster simulator of FPM daily ETo estimation that would be very useful in applications, such as areal ETo estimation research using satellite images, where fast and frequent re-evaluations of FPM ETo for millions of points are necessary.
The M-Matrix Group Generalized Inverse Problem for Weighted Trees

We characterize all weighted trees whose Laplacian has a group inverse which is an M-matrix. Actually, only a very narrow set of weighted trees yields such Laplacians. Our investigation involves analyzing circumstances under which a certain Z-matrix, derived from the tree and whose order is one less than the number of vertices in the tree, is an M-matrix. Our work here is motivated by a recent paper of Styan and Subak-Sharpe [ Linear Algebra Appl. , 250 (1997), pp. 349--370] and by an earlier question of Deutsch and Neumann [ J. Math. Anal. Appl. , 102 (1984), pp. 1--29].
Magnetic Field Strength in the Solar Corona from Type II Band Splitting

The phenomenon of band splitting in type II bursts can be a unique diagnostic for the magnetic field in the corona, which is, however, inevitably sensitive to the ambient density. We apply this diagnostic to the CME-flare event on 2004 August 18, for which we are able to locate the propagation of the type II burst and determine the ambient coronal electron density by other means. We measure the width of the band splitting on a dynamic spectrum of the bursts observed with the Green Bank Solar Radio Burst Spectrometer (GBSRBS), and convert it to the Alfvén Mach number under the Rankine-Hugoniot relation. We then determine the Alfvén speed and magnetic field strength using the coronal background density and shock speed measured with the MLSO/MK4 coronameter. In this way we find that the shock compression ratio is in the range of 1.5-1.6, the Alfvénic Mach number is 1.4-1.5, the Alfvén speed is 550-400 km s-1, and finally the magnetic field strength decreases from 1.3 to 0.4 G while the shock passes from 1.6 to 2.1 R☉. The magnetic field strength derived from the type II spectrum is finally compared with the potential field source surface (PFSS) model for further evaluation of this diagnostic.
Inference on cointegrating ranks using lr and lm tests based on pseudo-likelihoods

This paper considers Lagrange Multiplier (LM) and Likelihood Ratio (LR) tests for determining the cointegrating rank of a vector autoregressive system. n order to deal with outliers and possible fat-tailedness of the error process, non-Gaussian likelihoods are used to carry out the estimation. The limiting distributions of the tests based on these non-Gaussian pseudo-)likelihoods are derived. These distributions depend on nuisance parameters. An operational procedure is proposed to perform inference. It appears that the tests based on non-Gaussian pseudo-likelihoods are much more powerful than their Gaussian counterparts if the errors are fat-tailed. Moreover, the operational LM-type test has a better overall performance than the LR-type test. Copyright O 1998 by Marcel Dekker, Inc.
Decentralized estimation and control with overlapping information sets

The objective of this note is to present a solution to the decentralized estimation and control problem for linear discrete-time varying systems, composed of overlapping subsystems. The solution is based on the expansion-contraction framework of the inclusion principle. It is shown how decentralized estimation and control laws can be independently computed for the expanded system, and then contracted for implementation in the original system to satisfy the overlapping information structure constraint.
The Effect of Metallic Plate on the Displacement in Bilayer Piezoelectric/Electrostrictive Dome Unimorph

A dome piezoelectric-electrostrictive monolithic bilayer composite (PE-MBLC) actuator is attached to a thin metallic plate by insulating epoxy resin to form a flextensional actuator. Such flextensional actuator is called bilayer piezoelectric/electrostrictive dome unimorph (BIPEDU). Under the application of an electric field, the force generated from radial contraction of PE-MBLC was transferred through the bonding area to deform the metallic plate, generating more displacement in BIPEDU actuator. In this study, a PE-MBLC with the P:E volume ratio of 8:2 was used as the active driving element and a metallic plate served as a flextensional structure. Different type of metallic plates showed different in the flexibility which will effect to strain amplification in BIPEDU. Therefore, the investigation of various metallic plates including stainless steel, brass, and aluminum with their thicknesses of 76 μm on the displacement of BIPEDU has studied. To examine the displacement, all PE-MBLCs and BIPEDUs were subjected to an E-field of 10 kV/cm. The results showed that displacement of all BIPEDUs with stainless steel, brass, and aluminum yielded higher displacement compared to PE-MBLCs. In addition, the experimental results of displacement in BIPEDUs with three different types of metallic plates indicated that the BIPEDU fabricated by using 76 μm thickness stainless steel yielded the highest displacement of ≈65 μm while BIPEDUs with brass and aluminum showed 45 and 32 μm, respectively.
Thresholds for rapid mass transfer in binary systems. I. Polytropic models

The adiabatic responses to mass loss of simple and compound polytropic star models are explored. The results show that stars in thermal equilibrium with isentropic surface layers are linearly unstable if the mass ratio exceeds a finite critical threshold q(0). Unless the mass fraction in these surface layers is quite small, q(0) is of the order of unity. On the other hand, stars in thermal equilibrium with subadiabatic surface layers are linearly stable for any value of the mass ratio. A finite-amplitude instability exists to which radiative stars are subject. If the initial phases of mass transfer are sufficiently rapid, such a star may undergo a delayed transition to dynamical time scale mass loss. Red giants with small core mass fractions behave very much like fully convective stars, expanding adiabatically as they lose mass. 32 references.
Identification of new infrared bands in a carbon-rich Mira variable

Complete 0.75-13 micron spectrometry of a carbon-rich, Mira-class variable star is presented for the first time. It is noted that although the near-infrared is dominated by photospheric absorption bands of the CN red system, the infrared becomes progressively dominated by the bands of the polyatomic molecules HCN and C2H2. Since the band at 3.1 microns is known to be due to HCN and C2H2, it is possible to associate bands at 1.04, 1.53, 1.85, 2.5, 2.7, 3.56, 3.85, 4.8, and 7.1 microns with HCN and C2H2. The spectrum suggests that radiative transfer in the carbon Mira class cannot be discussed quantitatively without the inclusion of HCN and C2H2 opacity. On the basis of the carbon star models of Querci and Querci (1974), it is deduced that the abundance ratio of HCN to C2H2 can be used to indicate whether 3-alpha-processed or CNO-processed material is in the outer atmosphere. An 11.3 micron SiC dust-emission feature is present, although it differs significantly from the 11.7 micron SiC feature in Y CVn. A featureless emission is present from 4 to 13 microns and can be ascribed to optically thin graphite grains having a temperature of 450 K.
(90377) SEDNA: INVESTIGATION OF SURFACE COMPOSITIONAL VARIATION

The dwarf planet (90377) Sedna is one of the most remote solar system objects accessible to investigations. To better constrain its surface composition and to investigate the possible heterogeneity of the surface of Sedna, several observations have been carried out at ESO-VLT with the powerful spectrometer SINFONI observing simultaneously the H and K bands. The analyzed spectra (obtained in 2005, 2007, and 2008) show a non-uniform spectral signature, particularly in the K band. Spectral modeling using the Shkuratov radiative transfer code for surface scattering has been performed using the various sets of data, including previous observations at visible wavelengths and photometry at 3.6 and 4.5 μm by the Spitzer Space Telescope. The visible and near-infrared spectra can be modeled with organic materials (triton and titan tholin), serpentine, and H2O ice in fairly significant amounts, and CH4, N2, and C2H6 in varying trace amounts. One of the spectra obtained in 2005 October shows a different signature in the K band and is best modeled with CH3OH in place of CH4, with reduced amounts of serpentine and with the addition of olivine. The compositional surface heterogeneity can give input on the past history as well clues to the origin of this peculiar, distant object.
Verification of Typhoon Forecasts for a 20 km-mesh High-Resolution Global Model

In this study, twelve tropical storms between 2002 and 2005 over the western North Pacific Ocean, namely, typhoons, were simulated through medium-range forecast experiments with the 20 km-mesh Japan Meteorological Agency (JMA) and Meteorological Research Institute (MRI) Atmospheric General Circulation Model (JM-AGCM). These simulations were compared with the 60 km-mesh JMA Global Spectral Model (GSM) to evaluate differences in resolution. They are verified with the best-track data as an observation. The verification was conducted in terms of estimating error of position, intensifying tendency, radius of 50 knot, 30 knot, and composite wind profile. This paper addresses the importance of such high resolution to predict typhoon’s intensity and inner-core structure. As a result, the JM-AGCM shows slightly smaller position error than the GSM. Moreover, much improvement was seen in the intensity prediction. The JM-AGCM outstandingly can both decrease the central sea level pressure and increase maximum wind velocity, while the GSM can not simulate them because of low resolution. The JM-AGCM also shows better intensifying and decaying tendency than the GSM. The verifications of 50 knot and 30 knot radii, and the composite wind profile indicate that the typhoon structure by the JM-AGCM is quite realistic. Moreover, the JM-AGCM expresses the drastic transformation of inner-core wind profile within 100km from the typhoon center more realistically than the GSM. These results indicate that a high resolution global model, such as 20 km-mesh, is vital when discussing the intensity and wind profile of tropical storms.
Testing for efficiency and non-linearity in market and natural time series

Abstract Time series in traded markets such as currencies and securities involve supply/demand interaction, so they might be expected to contain distinctive and identifiable structures in comparison with data based on natural phenomena such as river flows or sunspots. This paper tests this proposition using standard econometric tests including variance ratios, modified rescaled range (R/S) ratios and BDS statistics together with non-linear prediction models. Four time series of each type (market or natural) are subject to a battery of tests for random walk and non-linear dependence. Surprisingly, the tests provide no reliable discrimination between the two types of series or reveal any embedded specification differences.
Dynamics and Control of an Isolated Jet in Crossflow

Experimental results from a systematic exploration of the dynamics and control of large-scale, organized structures in an isolated, circular jet issuing into a uniform crosse ow with a jet-to-crosse ow velocity (or blowing) ratio of 6 are presented. Surveys of the unsteady e owe eld were conducted using a single sensor hot-e lm probe, and the instantaneous and time-averaged scalar e elds were explored using Mie scattering-based e ow visualization. A spinning mechanical valve was used to modulate the jet e ow with a single frequency. The forced e ow response illustrates the e ow receptivity to high frequencies near the jet exit (associated with the jet instabilities) and to low frequencies farther downstream (where the counter-rotating vortex pair dynamics are dominant). Open-loop forcing in a jet Strouhal number around SrD =0.1 was recognized and demonstrated to be effective in organizing unsteadiness and enhancing mixing and entrainment in the e owe eld. Measurements of the time-averaged velocity and scalare eldsareusedtodemonstrateincreasedmassentrainmentandmixingasaresultoftheunsteady forcing.
A new breakup regime of liquid drops identified in a continuous and uniform air jet flow

A new breakup regime of liquid drops, named the dual-bag breakup regime, in a continuous and uniform air jet flow is identified at We ranging from 28 to 41 at the present investigation. The dual-bag breakup regime is characterized by two successive bag breakup processes; the first one is suffered by the initial main drop, and the second one is suffered by the core drop produced in the first bag breakup process. Shadowgraph and high-speed cameras were used to record the temporal properties of liquid drops in the dual-bag breakup regime. Parameters including breakup time, drop deformation rate, and volume fraction of core drop, are measured and given as a function of Weber numbers in the dual-bag breakup regime.