Miracle-dz/UniFAR-FTUs huggingface dataset:
Ordinal regression revisited: multiple criteria ranking with a set of additive value functions

We present a new method (called UTA GMS ) for multiple criteria ranking using strongly and weakly established weak preference relations which result from an ordinal regression. The preference information supplied by the decision maker is a set of pairwise comparisons of reference alternatives. The preference model built via ordinal regression is a set of general additive value functions. The method provides two ﬁnal rankings: a strong ranking identifying “sure” preference statements, and a weak ranking identifying “possi-ble” preference statements. In order to build these two rankings, the method takes into account all value functions compatible with the preference information. The UTA GMS method is intended to be used interactively, with progressive statement of pairwise comparisons. Moreover, the method can support the decision maker also when his/her preference statements cannot be represented in terms of an additive value function. The method is illustrated by an example solved using the UTA GMS software. Some extensions of the method are also presented.
The Definition and Classification of Extensive and Persistent Extreme Cold Events in China

Abstract Using the observed daily temperatures from 756 stations in China during the period from 1951 to 2009, extensive and persistent extreme cold events (EPECEs) were defined according to the following three steps: 1) a station was defined as an extreme cold station (ECS) if the observed temperature was lower than its 10th percentile threshold; 2) an extensive extreme cold event was determined to be present if the approximated area occupied by the ECSs was more than 10% of the total area of China (83rd percentile) on its starting day and the maximum area occupied by the ECSs was at least 20% of the total area of China (96th percentile); and 3) an EPECE was determined to be present if the extensive extreme cold event lasted for at least for eight days. 52 EPECEs were identified in this manner, and these identification results were also verified using other reliable data. On the basis of cluster analysis, five types of EPECEs were classified according to the spatial distribution of ECSs at their most extensive time over the course of the EPECE.
A High shear stress segment along the San Andreas Fault: Inferences based on near-field stress direction and stress magnitude observations in the Carrizo Plain Area

Nearly 200 new in-situ determinations of stress directions and stress magnitudes near the Carrizo plain segment of the San Andreas fault indicate a marked change in stress state occurring within 20 km of this principal transform plate boundary. A natural consequence of this stress transition is that if the observed near-field ``fault-oblique`` stress directions are representative of the fault stress state, the Mohr-Coulomb shear stresses resolved on San Andreas sub-parallel planes are substantially greater than previously inferred based on fault-normal compression. Although the directional stress data and near-hydrostatic pore pressures, which exist within 15 km of the fault, support a high shear stress environment near the fault, appealing to elevated pore pressures in the fault zone (Byerlee-Rice Model) merely enhances the likelihood of shear failure. These near-field stress observations raise important questions regarding what previous stress observations have actually been measuring. The ``fault-normal`` stress direction measured out to 70 km from the fault can be interpreted as representing a comparable depth average shear strength of the principal plate boundary. Stress measurements closer to the fault reflect a shallower depth-average representation of the fault zone shear strength. If this is true, only stress observations at fault distances comparable to the seismogenic depth will be representative of the fault zone shear strength. This is consistent with results from dislocation monitoring where there is pronounced shear stress accumulation out to 20 km of the fault as a result of aseismic slip within the lower crust loading the upper locked section. Beyond about 20 km, the shear stress resolved on San Andreas fault-parallel planes becomes negligible. 65 refs., 15 figs.
Online Product Reviews: Implications for Retailers and Competing Manufacturers

This paper studies the effect of online product reviews on different players in a channel structure. We consider a retailer selling two substitutable products produced by different manufacturers, and the products differ in both their qualities and fits to consumers' needs. Online product reviews provide additional information for consumers to mitigate the uncertainty about the quality of a product and about its fit to consumers' needs. We show that the effect of reviews on the upstream competition between the manufacturers is critical in understanding which firms gain and which firms lose. The upstream competition is affected in fundamentally different ways by quality information and fit information, and each information type has different implications for the retailer and manufacturers. Quality information homogenizes consumers' perceived utility differences between the two products and increases the upstream competition, which benefits the retailer but hurts the manufacturers. Fit information heterogenizes consumers' estimated fits to the products and softens the upstream competition, which hurts the retailer but benefits the manufacturers. Furthermore, reviews may also alter the nature of upstream competition from one in which consumers' own assessment on the quality dimension plays a dominant role in consumers' comparative evaluation of products to one in which fit dimension plays a dominant role. If manufacturers do not respond strategically to reviews and keep the same wholesale prices regardless of reviews i.e., the upstream competition is assumed to be unaffected by reviews, then, we show that reviews never hurt the retailer and the manufacturer with favorable reviews, and never benefit the manufacturer with unfavorable reviews, a finding that demonstrates why reviews' effect on upstream competition is critical for firms in online marketplaces.
Single-Dimensional Versus Multi-Dimensional Product Ratings in Online Marketplaces for Experience Goods

We examine the strategic implications of multi-dimensional and single-dimensional rating schemes in online review platforms when consumers have heterogeneous preferences regarding the product quality attributes. The multi-dimensional rating scheme provides a separate rating for each product attribute, whereas the single-dimensional scheme gives one overall rating for each product. The multi-dimensional rating scheme is superior to the single-dimensional rating scheme in reducing consumers’ uncertainty about the value of a product. However, we show that, when sellers respond to product ratings by adjusting their prices, the multi-dimensional rating scheme does not always benefit consumers. Furthermore, the multi-dimensional rating scheme does not necessarily benefit the platform, the sellers or the society compared to the singledimensional rating scheme. We find that factors such as whether firms specialize in an attribute (“attribute specialization”), whether competing firms offer differentiated products (“firm differentiation”), and whether the product is an experience good or a credence good (“product type”) play significant roles in determining the impact of a rating scheme on the platform, consumers, and the society. The main driver of the results is that the multi-dimensional ratings amplify the consumers’ perceptions of any underlying differentiation in the attributes of competing products, while simultaneously exposing the similarity between the products if they are homogeneous. In contrast, single-dimensional ratings mask the differentiation between attributes when the products are different but reflect the heterogeneous consumer preferences even when the products are similar. Therefore, the rating scheme alters the heterogeneity in consumer perceptions and utility, which, in turn, affects the upstream price competition. The results demonstrate that focusing on the information transfer aspect of rating schemes provides only a partial understanding of the true impact of rating schemes and that the platform’s optimal choice of a rating scheme depends critically on the product markets served by the platform.
Hybrid forecasting: combining dynamical predictions with data-driven models

Hybrid hydroclimatic forecasting systems employ data-driven (statistical or machine learning) methods to harness and integrate a broad variety of predictions from dynamical, physics-based models – such as numerical weather prediction, climate, land, hydrology and Earth System models – into a final prediction product. They are recognised as a promising way of enhancing prediction skill of meteorological and hydroclimatic variables and events, including rainfall, temperature, streamflow, floods, droughts, tropical cyclones, or atmospheric rivers. Hybrid forecasting methods are now receiving growing 5 attention due to advances in weather and climate prediction systems at sub-seasonal to decadal scales, a better appreciation of the strengths of machine learning, as well as expanding access to computational resources and methods. Such systems are attractive because they may avoid the need to run a computationally-expensive offline land model, can minimize the effect of biases that exist within dynamical outputs without explicit bias correction and downscaling, benefit from the strengths of machine learning, and can learn from large datasets, while combining different sources of predictability with varying time-10 horizons. Here we review recent developments in hybrid hydroclimatic forecasting and outline key challenges and opportunities for further research. These include obtaining physically-explainable results, assimilating human influences from novel data sources, integrating new ensemble techniques to improve predictive skill, creating seamless prediction schemes that merge short to long lead times, incorporating modelled initial land surface and ocean/ice conditions, acknowledging spatial variability in landscape and atmospheric forcing, and increasing the operational uptake of hybrid prediction schemes.
Generalised Anderson-Rubin statistic based inference in the presence of a singular moment variance matrix

The particular concern of this paper is the construction of a confidence region with pointwise asymptotically correct size for the true value of a parameter of interest based on the generalized Anderson-Rubin (GAR) statistic when the moment variance matrix is singular. The large sample behaviour of the GAR statistic is analysed using a Laurent series expansion around the points of moment variance singularity. Under a condition termed first order moment singularity the GAR statistic is shown to possess a limiting chi-square distribution on parameter sequences converging to the true parameter value. Violation, however, of this condition renders the GAR statistic unbounded asymptotically. The paper details an appropriate discretisation of the parameter space to implement a feasible GAR-based confidence region that contains the true parameter value with pointwise asymptotically correct size. Simulation evidence is provided that demonstrates the efficacy of the GAR-based approach to moment-based inference described in this paper.
Interpretation of inverted photocurrent transients in organic lead halide perovskite solar cells: proof of the field screening by mobile ions and determination of the space charge layer widths

In Methyl Ammonium Lead Iodide (MAPI) perovskite solar cells, screening of the built-in field by mobile ions has been proposed as part of the cause of the large hysteresis observed in the current/voltage scans in many cells. We show that photocurrent transients measured immediately (e.g. 100 μs) after a voltage step can provide direct evidence that this field screening exists. Just after a step to forward bias, the photocurrent transients are reversed in sign (i.e. inverted), and the magnitude of the inverted transients can be used to find an upper bound on the width of the space charge layers adjacent to the electrodes. This in turn provides a lower bound on the mobile charge concentration, which we find to be ≳1 × 1017 cm−3. Using a new photocurrent transient experiment, we show that the space charge layer thickness remains approximately constant as a function of bias, as expected for mobile ions in a solid electrolyte. We also discuss additional characteristics of the inverted photocurrent transients that imply either an unusually stable deep trapping, or a photo effect on the mobile ion conductivity.
Phytoplankton dynamic in permanent and temporary waters of Empordà Salt marshes (NE Spain)

Se ha estudiado la dinamica del fitoplancton en las lagunas costeras de Aiguamolls de lEmporda. El fitoplancton esta sujeto principalmente al control bottom-up, la variabilidad hidrologica y la disponibilidad de nutrientes tienen una mayor influencia en la composicion y distribucion de tamanos del fitoplancton, que el zooplancton. La concentracion de materia organica disuelta es el factor ambiental mas correlacionado con el crecimiento de la biomasa fitoplanctonica. Dada la proximidad entre las lagunas costeras y el mar, donde la ocurrencia de Proliferaciones de Algas Nocivas es cada vez mas frecuente, se realizan un inventario general de las especies mas abundantes del fitoplancton y se llevan a cabo analisis extensivos de la toxicidad. La mayoria de especies de dinoflagelados encontradas son potencialmente nocivas. Hay pocas especies en comun entre el mar y las lagunas, sin embargo, existen especies productoras de PANs caracteristicas de los ambientes lagunares.
Financial literacy around the world: an overview

Abstract In an increasingly risky and globalized marketplace, people must be able to make well-informed financial decisions. New international research demonstrates that financial illiteracy is widespread in both well-developed and rapidly changing markets. Women are less financially literate than men, the young and the old are less financially literate than the middle-aged, and more educated people are more financially knowledgeable. Most importantly, the financially literate are more likely to plan for retirement. Instrumental variables estimates show that the effects of financial literacy on retirement planning tend to be underestimated. In sum, around the world, financial literacy is critical to retirement security.
Financial Literacy and Financial Sophistication Among Older Americans

This paper analyzes new data on financial literacy and financial sophistication from the 2008 Health and Retirement Study. We show that financial literacy is lacking among older individuals and for the first time explore additional questions on financial sophistication which proves even scarcer. For this sample of older respondents over the age of 55, we find that people lack even a rudimentary understanding of stock and bond prices, risk diversification, portfolio choice, and investment fees. In view of the fact that individuals are increasingly required to take on responsibility for their own retirement security, this lack of knowledge has serious implications.
Caractérisation hydro-dispersive in situ de sols non saturés par infiltration d'eau et de soluté : cas de sols structures et de sols hétérogènes

La modelisation quantitative du transfert de l'eau et des solutes dans la zone non saturee des sols necessite la mesure in situ des parametres hydro-dispersifs. L'infiltrometrie sous pression controlee couplee a l'utilisation de traceurs de l'ecoulement de l'eau est pour cela un outil efficace et simple a mettre en oeuvre sur le terrain. La modelisation des transferts et l'analyse des resultats des calculs conduit a une methode simplifiee de caracterisation hydro-dispersive par infiltrometrie. La conductivite hydraulique K et la sorptivite S sont estimees a partir de l'analyse aux temps courts ou aux temps longs de l'infiltration cumulee. La methode mono-tracage est utilisee pour le calcul de la fraction d'eau mobile F. Une nouvelle methode d'estimation du coefficient de dispersion D est proposee. Elle est telle que D reste l'unique parametre a ajuster sur les donnees issues de l'echantillonnage du sol a la fin de l'infiltration. L'incertitude d'estimation est de plus definie pour chacun des parametres. Le domaine de validite des methodes est precise a partir de donnees generees numeriquement. Pour le calcul de K, S et F, il est defini a partir des temps caracteristiques de l'ecoulement de l'eau, de la lame de solution infiltree et de la dispersivite du milieu. La validite du mode de determination de D depend du nombre adimensionnel pext. Trois sols sont caracterises in situ. La porosite bimodale des deux premiers induit une forte augmentation des parametres hydrodynamiques a l'approche de la saturation, et de F avec la taille moyenne de pores hydrauliquement fonctionnels. Le troisieme est soumis a l'encroutement de surface. Les resultats de la caracterisation hydro-dispersive renforces par l'observation du reseau poral sur lames minces montre que le role des croutes de surface sur l'infiltrabilite est minimise par rapport a celui du sol sous-jacent. De plus, le sol sous-jacent semble protege de la coalescence par les croutes de surface.
Marine fish landings in Greater Mumbai during 1998-2004

Maharashtra ranks fourth among the maritime states of India. The important single centre zones like Sassoon Dock (SSD), New Ferry Wharf (NFW) and Versova are situated in Greater Mumbai (GRM). The landings per year in GRM was 2,30,000 t, which accounted nearly to 6O%0f Maharashtra landings. This report depicts the fishery of GRM based on the data for the period 1998 to 2004.
Radial velocity study of the pulsating subdwarf B star and possible Type Ia supernova progenitor KPD 1930+2752

We report the results of a high-time-resolution radial velocity study of the subdwarf B star and possible Type Ia supernova progenitor KPD 1930+2752. There were no significant peaks in the power spectrum of the velocity curve above our detection limit, about 4 km s - 1 , at the frequencies where peaks arising from pulsation were present in the photometric data of previous researchers. We report an orbital velocity amplitude, 348.5 ′ 1 km s - 1 , in agreement with that reported by previous investigators. We find an orbital period of P = 0.095 093 08 ′ 0.000 000 15 d based on our data and the ephemeris of Maxted et al.
Force-induced acoustic phonon transport across single-digit nanometre vacuum gaps.

Heat transfer between bodies separated by nanoscale vacuum gap distances has been extensively studied for potential applications in thermal management, energy conversion and data storage. For vacuum gap distances down to 20 nm, state-of-the-art experiments demonstrated that heat transport is mediated by near-field thermal radiation, which can exceed Planck's blackbody limit due to the tunneling of evanescent electromagnetic waves. However, at sub-10-nm vacuum gap distances, current measurements are in disagreement on the mechanisms driving thermal transport. While it has been hypothesized that acoustic phonon transport across single-digit nanometre vacuum gaps (or acoustic phonon tunneling) can dominate heat transfer, the underlying physics of this phenomenon and its experimental demonstration are still unexplored. Here, we use a custom-built high-vacuum shear force microscope (HV-SFM) to measure heat transfer between a silicon (Si) tip and a feedback-controlled platinum (Pt) nanoheater in the near-contact, asperity-contact, and bulk-contact regimes. We demonstrate that in the near-contact regime (i.e., single-digit nanometre or smaller vacuum gaps before making asperity contact), heat transfer between Si and Pt surfaces is dominated by force-induced acoustic phonon transport that exceeds near-field thermal radiation predictions by up to three orders of magnitude. The measured thermal conductance shows a gap dependence of $d^{-5.7\pm1.1}$ in the near-contact regime, which is consistent with acoustic phonon transport modelling based on the atomistic Green's function (AGF) framework. Our work suggests the possibility of engineering heat transfer across single-digit nanometre vacuum gaps with external force stimuli, which can make transformative impacts to the development of emerging thermal management technologies.
Dynamic Time Warping in Strongly Subquadratic Time: Algorithms for the Low-Distance Regime and Approximate Evaluation

Dynamic time warping distance (DTW) is a widely used distance measure between time series. The best known algorithms for computing DTW run in near quadratic time, and conditional lower bounds prohibit the existence of significantly faster algorithms. The lower bounds do not prevent a faster algorithm for the special case in which the DTW is small, however. For an arbitrary metric space $\Sigma$ with distances normalized so that the smallest non-zero distance is one, we present an algorithm which computes $\operatorname{dtw}(x, y)$ for two strings $x$ and $y$ over $\Sigma$ in time $O(n \cdot \operatorname{dtw}(x, y))$. We also present an approximation algorithm which computes $\operatorname{dtw}(x, y)$ within a factor of $O(n^\epsilon)$ in time $\tilde{O}(n^{2 - \epsilon})$ for $0 < \epsilon < 1$. The algorithm allows for the strings $x$ and $y$ to be taken over an arbitrary well-separated tree metric with logarithmic depth and at most exponential aspect ratio. Extending our techniques further, we also obtain the first approximation algorithm for edit distance to work with characters taken from an arbitrary metric space, providing an $n^\epsilon$-approximation in time $\tilde{O}(n^{2 - \epsilon})$, with high probability. Additionally, we present a simple reduction from computing edit distance to computing DTW. Applying our reduction to a conditional lower bound of Bringmann and Kunnemann pertaining to edit distance over $\{0, 1\}$, we obtain a conditional lower bound for computing DTW over a three letter alphabet (with distances of zero and one). This improves on a previous result of Abboud, Backurs, and Williams. With a similar approach, we prove a reduction from computing edit distance to computing longest LCS length. This means that one can recover conditional lower bounds for LCS directly from those for edit distance, which was not previously thought to be the case.
The Forgotten Middle Ensuring that All Students Are on Target for College and Career Readiness before High School Executive Summary

ACT data show that fewer than two in ten eighth graders are on target to be ready for college-level work by the time they graduate from high school. This means that more than eight of ten eighth-grade students do not have the knowledge and skills they need to enter high school and succeed there. And not surprisingly, our research shows that students who are not prepared for high school are less likely than other students to be prepared for college and career by the time they graduate from high school. So although the gates of high school are technically open to all students, for more than 80 percent of them, the door to their futures may already be closed.