Miracle-dz/UniFAR-FTUs huggingface dataset:
Forecasting with Factor-Augmented Regression: A Frequentist Model Averaging Approach, Second Version

This paper considers forecast combination with factor-augmented regression. In this framework, a large number of forecasting models are available, varying by the choice of factors and the number of lags. We investigate forecast combination across models using weights that minimize the Mallows and the leave-h-out cross validation criteria. The unobserved factor regressors are estimated by principle components of a large panel with N predictors over T periods. With these generated regressors, we show that the Mallows and leave-h-out cross validation criteria are asymptotically unbiased estimators of the one-step-ahead and multi-step-ahead mean squared forecast errors, respectively, provided that N, T → ∞. (However, the paper does not establish any optimality properties for the methods.) In contrast to well-known results in the literature, this result suggests that the generated-regressor issue can be ignored for forecast combination, without restrictions on the relation between N and T. Simulations show that the Mallows model averaging and leave-h-out cross-validation averaging methods yield lower mean squared forecast errors than alternative model selection and averaging methods such as AIC, BIC, cross validation, and Bayesian model averaging. We apply the proposed methods to the U.S. macroeconomic data set in Stock and Watson (2012) and find that they compare favorably to many popular shrinkage-type forecasting methods.
How do hydrologists perceive watersheds? A survey and analysis of perceptual model figures for experimental watersheds

To describe process knowledge at the watershed scale, hydrologists commonly refer to a ‘perceptual model’, an expert summary of the watershed and its runoff processes often supported by field observations. Perceptual models are often presented as a schematic figure, although such a figure will necessarily simplify the hydrologist's complex mental model. In this paper, our aim was to understand what constitutes a visual expert summary of watershed process knowledge, and to evaluate how perceptual models could be used to share hydrological process information at larger scales. To do so, we conducted a systematic review of the literature and found 63 perceptual model figures. We counted and categorized the stores and fluxes in each figure using a taxonomic classification and quantified a variety of figure attributes including spatial or temporal zonation, inclusion of vegetation, soils, topographical and geological data and consideration of uncertainty. Our analysis showed that a typical figure has 1 surface flux, 4 subsurface fluxes, 3–4 subsurface stores and 0–1 channel stores; 28 out of 63 figures use sub‐figures to show temporal dynamics (e.g., wet/dry conditions), and 12 out of 63 show spatial zones. Perceptual model figures, therefore, provide a concise summary of watershed processes with a complexity comparable to that of many conceptual hydrological models. However, only four figures showed any information on uncertainty or knowledge gaps. We recommend that perceptual figure value could be easily increased by consistent captioning of figures to assist automated search, and wider use of standard figure annotations such as legends and scale markings to ensure that information is fully conveyed to the user. If perceptual figures are proposed as a primary method for sharing process information, the hydrological community should consider how to link more detailed text descriptions to figures, and how to represent process uncertainty.
A nonlinear Galerkin method for numerical approximation of the dynamics of mesophases under flow

In recent years, many theoretical and computational studies have evidenced remarkable similarities between the long-time evolution of solutions of dissipative partial differential equations (PDEs) and solutions of finite-dimensional dynamical systems, or ordinary differential equations (ODEs): both possess a finite number of asymptotic degrees of freedom. With the inertial manifold theory, it is shown that certain dissipative PDEs have the same asymptotic behaviour of an appropriate finite dimensional ODEs system. Hence, this theory is extremely promising for numerical studies, because it allows reducing computational effort compared with traditional dynamic reduction procedures. In recent works, new numerical methods, inspired by the inertial manifold theory, such as nonlinear Galerkin methods, are developed. In the present work, we study the dynamics of the so-called Smoluchowski equation for liquid crystalline polymers with the Galerkin-Euler method (one of nonlinear Galerkin methods stemming from the inertial manifold theory), A comparison between the results obtained with traditional procedures and the new technique is developed. Since this method is adequate for the long-time behaviour of dynamical systems, the comparison is performed with bifurcation analysis by using a continuation algorithm.
The timing of post-juvenile moult and fuel deposition in relation to the onset of autumn migration in Reed Warblers Acrocephalus scirpaceus and Sedge Warblers Acrocephalus schoenobaenus

The extent of post-juvenile moult and fuel deposition prior to migration in Reed Warblers Acrocephalus scirpaceus and Sedge Warblers A. schoenobaenus were analysed using 11 years ringing data from Lake Kvismaren in South Central Sweden. Re-trap data showed that Reed Warblers acquired their first winter plumage in 34 days, compared to 22 days in Sedge Warblers. The moult pattern of the two species differed due to Sedge Warblers only undertaking a fill-in moult of bare body areas. Fuel deposition rates for the two species were similar, 0.38 g/day for Reed Warblers and 0.34 g/day for Sedge Warblers. The estimated average fuel stores at departure from Lake Kvismaren differed, with Reed Warblers found to leave with a fuel store of 21% (in relation to lean body mass) compared to 6.2% in Sedge Warblers. The median date of departure from Lake Kvismaren was estimated to 30 August for Reed Warblers and 12 August for Sedge Warblers. The earlier departure of Sedge Warblers, with smaller fuel stores, may reflect different migration strategies between the species.
Dynamic event-triggered adaptive fuzzy control for stochastic nontriangular nonlinear systems with unknown backlash-like hysteresis

A finite-time adaptive control is discussed in this paper for stochastic nontriangular nonlinear systems with unknown backlash-like hysteresis. The performance function is introduced to ensure that the tracking error of the system converges to the specified region in a finite time. Secondly, a controller is proposed using the fuzzy logic systems to approximate the unknown functions and backstepping technique. In addition, adding the dynamic event-triggered mechanism is able to reduce the network resources more effectively. At last, a few simulation examples are presented to demonstrate effective performance.
Minkowski-metrics as a combination rule for digital-image-coding impairments

The urge to compress the amount of information needed to represent digitized images while preserving perceptual image quality has led to a plethora of image-coding algorithms. At high data compression ratios, these algorithms usually introduce several coding artifacts, each impairing image quality to a greater or lesser extent. These impairments often occur simultaneously. For the evaluation of image-coding algorithms, it is important to find out how these impairments combine and how this can be described. The objective of the present study is to show that Minkowski-metrics can be used as a combination rule for small impairments like those usually encountered in digitally coded images. To this end, an experiment has been conducted in which subjects assessed the perceptual quality of scale-space-coded color images comprising three kinds of impairment, viz., 'unsharpness', 'phantoms' (dark/bright patches within bright/dark homogeneous regions) and 'color desaturation'. The results show an accumulation of these impairments that is efficiently described by a Minkowski-metric with an exponent of about two. The latter suggests that digital-image-coding impairments may be represented by a set of orthogonal vectors along the axes of a multidimensional Euclidean space. An extension of Minkowski-metrics is presented to generalize the proposed combination rule to large impairments.
Comprehensive contrast comparison of laver cultivation area extraction using parameters derived from polarimetric synthetic aperture radar data

Abstract Image contrast between extracted laver cultivation area and background water was extensively compared using various parameters that can be calculated by dual- and quad-polarization (fully polarimetric) synthetic aperture radar data. Each parameter derived from Pauli decomposition, eigenvalue analysis, coherence analysis, and four-component scattering power decomposition (4-CSPD) has distinctive characteristics and react to different backscatterers differently. Contrast comparison was made using these parameters using the L-band quad-polarization data acquired by phased-array L-band synthetic aperture radar (PALSAR) on board advanced land observing satellite (ALOS) and the X-band dual-polarization data acquired by TerraSAR-X, and experimental results showed that the contrast can be improved using multi-polarization data than using single-polarization data. It has also been found that entropy performs better among dual-polarization methods, and the surface scattering component calculated from 4-CSPD exhibits higher contrast than any other parameters from quad-polarization data.
Resolution tests of three-dimensional convection models by traveltime tomography: effects of Rayleigh number and regular versus irregular parametrization

SUMMARY We present here the results obtained from 3-D tomographic inversion of synthetic data in order to investigate the ability of tomography to reveal the detailed thermal structures created by mantle convective processes. The synthetic input velocity models are based on the density heterogeneities obtained from a 3-D spherical-shell model of thermal convection. P and pP arrival-times are used in the inversion. We study the effect of the length-scale of the input anomalies characterized by the Rayleigh number of convection simulations (Ra = 3 × 10 5 , 8 × 10 5 ,1 0 6 ) and asses the sensitivity of the inverse problem to parametrization and explicit regularization (damping). We concentrate mainly on the effect of projection error and we show that its role is substantial with increasing chaotic convective behaviour. We use both irregular cell parametrization and regular cell parametrization (equisurface area). Due to the uneven distribution of sources and receivers, we found substantial differences between inversion output for models with regular and irregular cells. For the irregular parametrization, the structures located in the well-covered regions are resolved quite successfully, although the resolving power decreases with depth. In the poorly covered regions, where the ray sampling demands large parametrization cells, the correspondence between the input and output is rather low due to high parametrization error. An explicit regularization is not needed if only the projection error is assumed. On the other hand, for the regular parametrization, the inverse problem is very unstable and oscillations occur, unless an explicit regularization is applied. However, if an optimum damping is applied, the global correlation between the input and output anomalies is substantially higher than in irregular case. Further, we compare the power spectra of input seismic velocity anomalies and the inversion output. In case of irregular parametrization, the spectra of input model and inversion output differ especially in the uppermost part of the lower mantle and in the lowermost mantle, again due to the high parametrization error associated with the large parametrization cells. Much better agreement between the spectra of input and output is obtained in regular parametrization model, provided that a proper damping is applied. Therefore, we conclude that on a global scale, the regular parametrization gives better results than the irregular one, while the inversion with the irregular parametrization is able to resolve much more detailed structures in well-covered regions with the same number of model parameters and thus with the same computational costs.
Questioning a Courtroom Proof of the Uniqueness of Fingerprints

Forensic scientists or analysts concerned with “individualization” often presume that features such as fingerprint minutia are unique to each individual. In the United States, defendants in criminal cases have been demanding proof of such assumptions. In at least two cases, the government of the United States has successfully relied on an unpublished statistical study prepared specifically for litigation to demonstrate the uniqueness of fingerprints. This article suggests that the study is neither designed nor executed in a way that can show whether an individual's fingerprint impressions are unique.
Resistance of river ice covers to mobilization and implications for breakup progression in Peace River, Canada

Prediction and modelling of ice breakup initiation and progress over extended river reaches is largely unattainable at present, despite the ecological and socio‐economic significance of the breakup event and associated ice jams that form in many rivers of Asia, Europe and North America. A key question is how to quantify the driving and resisting forces that are applied on the winter ice cover, which control the timing of its dislodgment, mobilization and subsequent jamming locations. Using a physics‐based onset criterion, explicit expressions for these forces are formulated. The more complex of the two is the resistance, which comprises components related to ice strength and thickness, channel curvature, thermal degradation of the ice cover during the pre‐breakup period, and freezeup level (defined as peak 7‐day running average water level during late fall and early winter). This insight is then used in a case study of recent dynamic breakups in a major Canadian river, explaining apparently random differences in the rate of advance of the breakup front among three different years. It is shown further that contradictory results are obtained when the effect of the freezeup level is ignored.
On the converse of the nonexpansive map fixed point theorem for Hilbert space

A simple proof is given of Ray's theorem that a nonempty, closed, convex, and unbounded set in Hilbert space admits a fixed point free nonexpansive map. A map T is nonexpansive on its domain K if IlTx Tyll 0} of the one-dimensional Hilbert space, then the map Tx = x + 1 is nonexpansive and is obviously fixed point free. If K is a nonempty, closed, convex, unbounded set in H which contains a half-line L, then K admits a fixed point free nonexpansive map. One simply uses the fact that there is a nearest point Chebyshev map of K onto L which is nonexpansive. Then one composes T by following the Chebyshev map onto L by the shift that was used above on that half-line. That would be all there is to it if a nonempty, closed, convex, unbounded set always contained a half-line. But this is not the case as elementary examples will show. W. 0. Ray [4] gave a proof of the theorem below using the fact (which he first established): If K is nonempty, closed, convex, and unbounded and, in addition, contains the origin (a harmless normalization for this affine problem), then H contains an orthonormal set {en: n > 1} so that el + * * + en is in K for all n. A rather noncomputational proof will be given below based on well-known properties of Hilbert spaces. THEOREM (RAY). If K is a nonempty, convex, closed, unbounded set in Hilbert space, then K admits a fixed point free nonexpansive map. PROOF. If a set in H looks bounded, it is bounded. This means that if each continuous linear functional on K is bounded, then K is a bounded set. This fact is a well-known version of the Banach Steinhaus Theorem. Thus if K is unbounded there is a continuous functional f so that Kn = {x in K: f(x) > n} is a nonempty subset of K for every n > 1. The sets {Kn } are also closed and convex so there is a Chebyshev nearest point map Pn from H onto Kn. Here is the Received by the editors March 25, 1986. 1980 Mathematics Subject Classification (1985 Revision). Primary 47H09, 47H10; Secondary 54H25. 1987 American Mathematical Society 0002-9939/87 $1.00 + $. 25 per page
Sustainable valorization of waste keyboard keys via microwave assisted pyrolysis over Fe-Ni doped green catalyst towards clean fuel production

ABSTRACT The technological evolution of electronic equipment in the field of computers and household appliances, along with shorter life of most items, is creating a great concern for managing this waste stream. The main aim of the present investigation was to convert waste keyboard keys into high-quality pyrolysis oil using a microwave catalytic pyrolysis process. Iron (Fe), Nickel (Ni), were doped in different ratios on Biochar (BC) by wet impregnation method, and it was used as a green catalyst for clean fuel production. Initially, a non-catalytic pyrolysis process was conducted and found a maximum pyrolysis oil yield of 49.6 wt. %. Further, microwave catalytic pyrolysis was conducted with variable amount of metal loading and found that highest oil yield of 61.33 wt. % was achieved using 15%Fe-5%Ni/BC catalyst due to the presence of a higher quantity of iron. The produced pyrolysis oil at this condition consists of 45.07% single-ring compounds and reduced the undesirable polycyclic aromatic hydrocarbons (PAHs) in the pyrolysis oil. This work provides a pathway for preparing green catalysts and safe disposal of electrical and electronic plastic waste with better resource recovery.
Patternable gel electrolyte infiltrated into all-solid porous Li-ion electrodes

Gel electrolyte based on 1M LiPF6 in ethylene carbonate:dimethyl carbonate, polyethyleneglycol diacrylate oligomer, and 2,2′-azobis(2-methylpropionitrile) is infiltrated into porous sintered LiCoO2 electrodes and cured in situ. The associated batteries function well, which is consistent with microscopy observations indicating that the gel electrolyte penetrates the electrode well and wets to the electrode particles. Trimethyl silyl acrylate is used to functionalize glass substrates and will cross link with polyethyleneglycol diacrylate during curing to promote bonding between the substrate and the gel electrolyte. The functionalization can localize adhesion allowing the electrolyte to easily release from unfunctionalized glass, which can be used as a mold.
Serum protein measurement using a tapered fluorescent fibre-optic evanescent wave-based biosensor

A novel method to measure the total serum protein concentration is described in this paper. The method is based on the principles of fibre-optic evanescent wave spectroscopy. The biosensor applies a fluorescent dye-immobilized porous glass coating on a multi-mode optical fibre. The evanescent wave's intensity at the fibre-optic core-cladding interface is used to monitor the protein-induced changes in the sensor element. The sensor offers a rapid, single-step method for quantifying protein concentrations without destroying the sample. This unique sensing method presents a sensitive and accurate platform for the quantification of protein.
Influence of dispersion on the transmission characteristics of supertwisted nematic effects in liquid‐crystal displays

The transmission properties of director configurations with a 180° twist and low tilt (∼1°) and of director configurations with a 270° twist and high tilt (∼25°) were calculated and compared with experimental data. It was found that the dispersion in the birefringence must be taken into account in order to properly calculate transmission wavelength spectra. This appeared to be of special importance for materials with large birefringence.
Terahertz waveguide multiplexers: A review

Terahertz (THz) band, which owns abundant and underexplored frequency spectrum, has provided rich scientific and technological opportunities in numerous research fields, such as radio astronomy, atmospheric science and high‐speed communication. As one of the key components in THz systems, the multiplexer cannot only separate/combine different bands, but can also promote the development of THz instruments toward wider band and more multibands. Thanks to the high‐precision computer numerical control milling and micromachining technologies, a lot of THz waveguide multiplexers have been reported in recent years. According to the classification of design configurations, this article offers a brief overview on the developed THz multiplexers. In addition, the performance and system applications of different waveguide‐typed multiplexers are discussed. Therefore, this review will provide a valuable reference for the further development of THz waveguide multiplexers with high performance.
Water Vapor and ice Mass Transported into the Anvils Of CCOPE Thunderstorms: Comparison with Storm Influx and Rainout

Abstract The transport of water substance (ice and vapor) into the anvils of midlatitude continental thunderstorms is examined. Doppler radar reflectivity fields and horizontal and vertical windfields, in situ anvil measurements, and environmental soundings were used to estimate the anvil water mass flux for approximately five-minute intervals over one hour periods in six moderate to severe storms. Vapor and ice mass fluxes into the anvil time-averaged for the study periods are about equal. Ratios of the time-averaged sums of these fluxes (A¯) to aircraft-derived cloud base influx (from Fankhauser) range from 18% to greater than 100%. Estimated accuracies are ±30 to 40%. Anvil fluxes exceed rainout at cloud base level as derived from radar reflectivity data by Fankhauser for half the storms. It is shown that influx values alone are not reliable predictors of total storm condensation rates. The water mass storage term is evaluated and is found to be unimportant in relation to influx for all but one storm s.
Theory of emission-angle-dependent Auger transitions in ion-atom collisions

By means of a continuum distorted-wave approximation of the post-collision state the authors derive an analytical equation for the Auger emission amplitude in ion-atom collisions. This theory includes previous models as particular cases. The authors further show that the presence of the projectile strongly affects the intensity profile, giving rise to a dependence on the emission angle that is missed in previous theories. In particular, a sharp enhancement in the forward direction is computed.
Beamforming experiment with a DBF multibeam antenna in a mobile satellite environment

This paper describes a digital beamforming (DBF) multibeam antenna that incorporates a compact digital signal processor (DSP) engine, and the results of using it in a beamforming experiment receiving a satellite signal in a land-mobile environment. A considerable reduction in the scale of the DSP engine has been achieved by using field programmable gate arrays (FPGAs). To capture a satellite signal arriving from an unknown direction, a two-dimensional (2-D) spatial FFT signal processing provides orthogonal multibeam patterns on the broad side of a planar array antenna. The experimental results demonstrated the features of coarse acquisition and tracking of a signal arrival by selecting the strongest of the beams without assistance from direction finding sensors or microwave phase shifters. The DBF multibeam antenna will provide high-quality communications and increase traffic capacity if it is applied to high-gain mobile antennas or multispot-beam base station antennas in cellular or satellite mobile communications.