Miracle-dz/UniFAR-FTUs huggingface dataset:
Convergence Rates for Stochastic Approximation on a Boundary

We analyze the behavior of projected stochastic gradient descent focusing on the case where the optimum is on the boundary of the constraint set and the gradient does not vanish at the optimum. Here iterates may in expectation make progress against the objective at each step. When this and an appropriate moment condition on noise holds, we prove that the convergence rate to the optimum of the constrained stochastic gradient descent will be diﬀerent and typically be faster than the unconstrained stochastic gradient descent algorithm. Our results argue that the concentration around the optimum is exponentially distributed rather than normally distributed, which typically determines the limiting convergence in the unconstrained case. The methods that we develop rely on a geometric ergodicity proof. This extends a result on Markov chains by Hajek [14] to the area of stochastic approximation algorithms. As examples, we show how the results apply to linear programming and tabular reinforcement learning.
Identity Based Distributed Provable Data Possession in Multi Cloud Storage

— loud computing has become an important thing in computer field. Cloud computing takes information processing as a service, such as storage and computing. Data integrity is important thing in cloud storage. In certain situations, clients should store their data such as image or text in multi cloud. When the client stores his/her data on multi-cloud servers, the distributed storage and integrity checking is very important. Here we propose an Identity Based Distributed Provable Data Possession (ID-DPDP) protocol for multi-cloud storage. Remote data integrity checking is important in cloud storage. It can make the clients verify whether their data is kept as it is without downloading the entire data. In some application scenarios, the clients have to store their data on multi-cloud servers. At the same time, the integrity checking protocol must be efficient in order to save the verifier’s cost.
Guidelines for Effective Bridging in Global Software Engineering

Globally-distributed software engineering involves one or more of geographic, temporal or cultural distances, which empirical studies find have deleterious effects on the efficiency of the software engineering process. There have been some successful examples where one "bridge" location has facilitated collaboration and coordination across the other locations. Managers might want to use this bridging as a tactic for future projects, even when future collaborations may be composed of very different participants and in different locations and contexts than current successfully bridged teams. However, group behavior is complicated and establishing an effective bridge is neither a simple nor a straightforward step. We propose a set of guidelines, based on empirical findings, to help managers understand what to expect from the bridging tactic. These include cultural, organizational, individual and temporal factors as well as insights into the costs and benefits of bridging.
Nurbs Approximation of A-Splines and A-Patches

Given A-spline curves and A-patch surfaces that are implicitly defined on triangles and tetrahedra, we determine their NURBS representations. We provide a trimmed NURBS form for A-spline curves and a parametric tensor-product NURBS form for A-patch surfaces. We concentrate on cubic A-patches, providing a C1-continuous surface that interpolates a given triangulation together with surface normals at the vertices. In many cases we can generate cubic trimming curves that are rationally parametrizable on the triangular faces of the tetrahedra; for the remaining faces we resort to using quadratic curves, which are always rationally parametrizable, to approximate the cubic trimming curves.
Downscaling precipitation using regional climate models and circulation patterns toward hydrology

The aim of this paper is to define a method for determining reasonable estimates of rainfall modeled by global circulation models (GCMs) coupled with regional climate models (RCMs). The paper describes and uses two new procedures designed to give confidence in the interpretation of such rainfall estimates. The first of these procedures is the use of circulation patterns (CPs) to define quantile‐quantile (Q‐Q) transforms between observed and RCM‐estimated rainfall (the CPs were derived from sea level pressure (SLP) fields obtained from reanalysis of historical daily weather in a previous study). The Q‐Q transforms are derived using two downscaling techniques during a 20 year calibration period and were validated during a 10 year period of observations. The second novel procedure is the use of a double Q‐Q transform to estimate the rainfall patterns and amounts from GCM‐RCM predictions of SLP and rainfall fields during a future period. This procedure is essential because we find that the CP‐dependent rainfall frequency distributions on each block are unexpectedly different from the corresponding historical distributions. The daily rainfall fields compared are recorded on a 25 km grid over the Rhine basin in Germany; the observed daily data are averaged over the grid blocks, and the RCM values have been estimated over the same grid. Annual extremes, recorded on each block during the validation period, of (1) maximum daily rainfall and (2) the lowest 5% of filtered rainfall were calculated to determine the ability of RCMs to capture rainfall characteristics which are important for hydrological applications. The conclusions are that (1) RCM outputs used here are good at capturing the patterns and rankings of CP‐dependent rainfall; (2) CP‐dependent downscaling, coupled with the double Q‐Q transform, gives good estimates of the rainfall during the validation period; (3) because the RCMs offer future CP‐dependent rainfall distributions that are different from the observed distributions, it is judged that these predictions, once modified by the double Q‐Q transforms, are hydrologically reasonable; and (4) the climate in the Rhine basin in the future, as modeled by the RCMs, is likely to be wetter than in the past. The results suggest that such future projections may be used with cautious confidence.
L'urbanisation a-t-elle changé les caractéristiques des débits écologiques dans le Maine (USA)?

Abstract This paper examines the potential effects of urbanization on streamflow in Maine, USA, from 1950 to 2000. The study contrasts nine watersheds in southern Maine, which has seen steady urban growth over the study period, with nine rural watersheds from northern Maine. Historical population data and current land cover data are used to develop an urbanization score for each watershed. Trends in watershed urbanization over the study period are compared to trends in ecologically relevant streamflow characteristics. The results indicate that trends in northern, rural watersheds are much more consistent than the trends in the southern watersheds. Additionally, trends in the southern watersheds are inconsistent with the hydrological characteristics observed in urban watersheds elsewhere, likely due to the comparatively low level of current urban development in Maine's urban watersheds. Our study suggests that urban areas in Maine have not yet reached an urbanization threshold where streamflow impacts beco.
Measure the Diversity of Open Source Software Projects' Forks with Fork Entropy

Forks play a central role in modern pull-based OSS development. Although rich empirical results on the participants, challenges, and features of forks have been announced, there is little discussion on quantitatively measuring the population of forks around OSS projects. In this paper, we take a step toward enriching the set of metrics about forks by proposing the fork entropy to measure the diversity of fork populations around OSS projects. We operationalize the proposed fork entropy based on Rao’s quadratic entropy with a distance function deﬁned on the forks’ modiﬁcations to project ﬁles. After verifying the construct validity of fork entropy, we show the usefulness of fork entropy in understanding and predicting OSS development in terms of external productivity, the acceptance rate of external pull-requests, and code quality using a dataset consisting of ﬁfty popular OSS projects hosted on GitHub. By conducting regression analyses, we ﬁnd that fork entropy signiﬁcantly and positively aﬀects external productivity, the acceptance rate of external pull-requests, and code quality, even though sometimes with a small eﬀect. However, as expected, fork entropy at a high level sometimes plays a negative role in OSS development. We also observe fork entropy can magically moderate other factors’ eﬀect on some project outcomes. We believe our new metric of fork entropy is helpful to guide practices of OSS development.
The new Athena alpha particle X‐ray spectrometer for the Mars Exploration Rovers

[1] The new alpha particle X-ray spectrometer (APXS) is part of the Athena payload of the two Mars Exploration Rovers (MER). The APXS sensor head is attached to the turret of the instrument deployment device (IDD) of the rover. The APXS is a very light-weight instrument for determining the major and minor elemental composition of Martian soils, rocks, and other geological materials at the MER landing sites. The sensor head has simply to be docked by the IDD on the surface of the selected sample. X-ray radiation, excited by alpha particles and X rays of the radioactive sources, is recorded by a high-resolution X-ray detector. The X-ray spectra show elements starting from sodium up to yttrium, depending on their concentrations. The backscattered alpha spectra, measured by a ring of detectors, provide additional data on carbon and oxygen. By means of a proper calibration, the elemental concentrations are derived. Together with data from the two other Athena instruments mounted on the IDD, the samples under investigation can be fully characterized. Key APXS objectives are the determination of the chemistry of crustal rocks and soils and the examination of water-related deposits, sediments, or evaporates. Using the rock abrasion tool attached to the IDD, issues of weathering can be addressed by measuring natural and abraded surfaces of rocks.
Litterfall production in a tropical mangrove of Sarawak, Malaysia

Assessment of litterfall production is essential to ascertain the status of nutrient cycling and forest health. Sarawak, Malaysia, is endowed with numerous pristine and estuarine mangroves; however, research on primary productivity of these forests is scanty. Therefore, litterfall production in a pristine Sibuti mangrove of Sarawak was estimated using litter traps for one year (January–December 2013), and forest structure was studied through tree census. The forest was dominated by Rhizophora apiculata (relative density [RD] was 77.11%), followed by Xylocarpus granatum (RD was 16.92%) and other species (RD was only 5.97%). The annual dry weight of litterfalls was estimated to be 1640.82 g m−2, of which R. apiculata contributed 92.94%, followed by X. granatum (4.01%) and other species (3.05%). Leaves were the most abundant (57.21%) contributory component of litters, followed by propagules (11.89%), flowers (10.85%), twigs (8.56%), and stipules (8.45%). No significant correlations were found for total litte.
Effect of climate change on food crop production and vulnerability assessment in Oyo State

The study assessed household vulnerability to climate change and its effect on yam and cassava production in Oyo state, Nigeria. Primary and secondary data were used for the study. Data on yam and cassava yield between 1990 and 2009 were obtained from the Oyo State Agricultural Development Programme (ADP) while data on climate variables between 1976 and 2010 were obtained from the Nigeria Institute of Meteorology, Oshodi. Primary data on the components of vulnerability that is adaptive capacity, sensitivity and exposure were also obtained from cassava and yam farmers using structured questionnaire to assess their vulnerability to climate change. Multistage sampling technique was employed to select 120 respondents across the three agro-ecological zones of the study area. This was done by purposively selecting five farm villages in each of the three agro-ecological zones in the study area and randomly selecting eight farmers from each of the villages. Trend, regression and principal component analytical tools were used to analyze data collected. The integrated vulnerability assessment approach was adopted using the vulnerability indicator. The result showed that the mean annual temperature and mean annual sunshine hour have been increasing by an average of 0.012oC (p<0.01) and 0.004 hours (p<0.01) per year respectively. This confirms the occurrence of global warming in the study area. The study revealed that sunshine hour significantly (p<0.05) affected yam yield. Household’s vulnerability to climate change in the three agro ecological zones as measured by the vulnerability index (VI) was found to be highest in the derived savannah (VI=-0.99) followed by the savannah (VI=0.46) and lowest in the rain forest (VI=0.53). The derived savannah zone recorded the highest vulnerability with a relatively low proportion of the population having access to quality home (2.5%), insecticide (30%), fertilizer (30%), improved seedlings (30%), road (15%), health services (15%), primary and secondary schools (15%), veterinary services (0.03%), food market (42.5%), and microfinance institutions (0.03%). The study recommended among others that crop-breeding researchers should work towards developing improved varieties of cassava and yam that can cope with future expected change in climate. Also, integrated rural development schemes aimed at increasing access to basic social amenities should be established by the government with the cooperation of the residents as this will improve adaptive capacity and thereby reduce vulnerability of farmers to climate change in the study area. Key words: Climate change, Vulnerability, Food, Crop production, Oyo State
Convolutional vs. Recurrent Neural Networks for Audio Source Separation

Recent work has shown that recurrent neural networks can be trained to separate individual speakers in a sound mixture with high fidelity. Here we explore convolutional neural network models as an alternative and show that they achieve state-of-the-art results with an order of magnitude fewer parameters. We also characterize and compare the robustness and ability of these different approaches to generalize under three different test conditions: longer time sequences, the addition of intermittent noise, and different datasets not seen during training. For the last condition, we create a new dataset, RealTalkLibri, to test source separation in real-world environments. We show that the acoustics of the environment have significant impact on the structure of the waveform and the overall performance of neural network models, with the convolutional model showing superior ability to generalize to new environments. The code for our study is available at this https URL
EgoDist: Comparing networks via distributions of egonet features

Identifying networks with similar characteristics in a given ensemble, or detecting pattern discontinuities in a temporal sequence of networks, are two examples of tasks that require an effective metric capable of quantifying network (dis)similarity. Here we propose a method based on a global portrait of graph properties built by processing local nodes features. More precisely, a set of dissimilarity measures is deﬁned by elaborating the distributions, over the network, of a few egonet features, namely the degree, the clustering coefﬁcient, and the egonet persistence. The method, which does not require the alignment of the two networks being compared, exploits the statistics of the three features to deﬁne one-or multi-dimensional distribution functions, which are then compared to deﬁne a distance between the networks. The effectiveness of the method is evaluated using a standard classiﬁcation test, i.e., recognizing the graphs originating from the same synthetic model. Overall, the proposed distances have performances comparable to the best state-of-the-art techniques (graphlet-based methods) with similar computational requirements. Given its simplicity and ﬂexibility, the method is proposed as a viable approach for network comparison tasks.
Working Papers in Economics and Statistics Firm Growth in Multinational Corporate Groups Firm Growth in Multinational Corporate Groups

This paper formulates an econometric firm growth model that explicitly accounts for the interdependence of firm performance within corporate networks and is in line with several economic theories on firm growth. We estimate the model for national and multinational corporate groups (MNEs) using a recently introduced instrumental variable estimation procedure for peer group effects developed by Lee (2007). In our data for corporate groups the observation of fast growing young firms and slow growing old firms disappears if interdependence of firm performance within corporation networks is introduced.
First application of titanium-in-zircon thermometry to ultrahigh-temperature metamorphism

Titanium-in-zircon thermometry has been applied to evaluate the temperatures of metamorphism for two ultrahigh-temperature (UHT) granulite localities, the Neoproterozoic Anapolis-Itaucu Complex in central Brazil, and lower crustal xenoliths from the Neo-archean Kaapvaal craton in South Africa. UHT metamorphism in the Anapolis-Itaucu Complex occurred ca. 640 Ma. Ti-in-zircon thermometry on metamorphic zircon yields temperatures of 965–811 °C; a population of late zircon that formed from ilmenite and rutile breakdown records temperatures of ∼780 °C. Maximum temperatures are less than those inferred from quantitative phase equilibria modeling. Based on textural setting (inclusions in peak phases and as matrix grains), these zircons likely record growth during the pro-grade and/or postpeak evolution. In contrast, the Kaapvaal xenoliths record two phases of zircon growth: during UHT metamorphism at 2720–2715 Ma, followed by growth during isobaric cooling in kyanite-bearing leucosomes ca. 2690 Ma. Temperatures recorded by the two phases of growth are 1024–878 °C and 936–839 °C, respectively, suggesting that zircon growth occurred during UHT conditions and continued throughout the postpeak evolution over a 200 °C interval. These examples demonstrate that the Ti-in-zircon thermometer is a powerful new tool with the potential to determine crystallization temperatures of zircon during granulite facies metamorphism, throughout the prograde to postpeak evolution of such terranes.
Does Interaction Help Users Better Understand the Structure of Probabilistic Models?

Probabilistic modeling needs specialized tools to support modelers, decision-makers or researchers in the design, checking, refinement and communication of models. Users’ comprehension of probabilistic models is vital in all above cases and interactive visualizations could enhance it. Although there are various studies evaluating interactivity in Bayesian reasoning and available tools for visualizing the inference-related distributions, we focus specifically on evaluating the effect of interaction on users’ comprehension of probabilistic models’ structure. We conducted a user study based on our Interactive Pair Plot for visualizing models’ distribution and conditioning sample space graphically. Our results suggest that improvements in the understanding of the interactive group are most pronounced for more exotic structures, such as hierarchical models or unfamiliar parameterisations in comparison to the static group. As the detail of the inferred information increases, interaction does not lead to considerably longer response times. Finally, interaction improves users’ confidence.
Quantifier elimination in the theory of an algebraically-closed field

In this paper we develop a fast parallel procedure for deciding when a set of multivariate polynomials with coefficients in an arbitrary field <italic>K</italic> have a common algebraic solution. Moreover, since the proposed algorithm is algebraic, it easily yields a procedure for quantifier elimination in the theory of an arbitrary algebraically closed field. More precisely, we show how to decide whether <italic>m</italic> polynomials in <italic>n</italic> variables, each of degree at most <italic>d</italic>, with coefficients in an arbitrary field <italic>K</italic> have a common zero in the algebraic closure of <italic>K</italic>, using sequential time (<italic>mn</italic>)<italic><supscrpt>&Ogr;(n)</supscrpt></italic><italic>d</italic><italic><supscrpt>&Ogr;(n)</supscrpt></italic><supscrpt>2</supscrpt>), or parallel time <italic>&Ogr;</italic>(<italic>n</italic><supscrpt>3</supscrpt> log<supscrpt>3</supscrpt> <italic>d</italic> log <italic>m</italic>) with (<italic>mn</italic>)<italic><supscrpt>&Ogr;</supscrpt></italic>(<italic>n</italic>)<italic>d</italic><supscrpt><italic>&Ogr;(n)</italic></supscrpt><supscrpt>2</supscrpt>) processors, in the operations of the coefficient field <italic>K</italic>. Using randomization, this may be improved to (<italic>mn</italic>)<italic><supscrpt>&Ogr;</italic>(1)</supscrpt><italic>d<supscrpt>&Ogr;</italic>(<italic>n</italic>)</supscrpt> time. In addition, the construction is used give a direct EXPSPACE algorithm for quantifier elimination in the theory of an algebraically-closed field, which runs in PSPACE or parallel polynomial time when restricted to formulas with a fixed number of alternations of quantifiers.
Verifying Southern Hemisphere trends in atmospheric carbon dioxide stable isotopes

[1] Stable isotopes of carbon dioxide distinguish between oceanic and terrestrial uptake of accumulating atmospheric carbon dioxide. At Cape Grim (41°S, 141°E), two Commonwealth Scientific and Industrial Research Organisation programs provide δ13C and δ18O of CO2 employing different collection, sample pretreatment, and calibration strategies that exemplify calibration problems. A comprehensive reexamination of methods results in δ13C agreement of 0.005 ± 0.004‰ through 14 overlapping years of data and suggests we have described and accounted for the main sources of bias. For δ18O, flask storage effects and early standard assignment problems contribute to larger variation and the comparable differences are 0.024 ± 0.184‰. Cape Grim records are reissued with uncertainties reflecting the histories of each method, as well as selected “best” records for δ13C from 1981, and for δ18O from 1978. The uncertainties reflect the internal consistency against an in-house reference, of most interest in determining the limits of temporal behavior, and can be combined with a larger fixed uncertainty if a Cape Grim record is used to quantify spatial differences from sites operated by different measurement laboratories. Marked variability on seasonal and interannual timescales is observed in both isotope records. The geographical location and sampling strategy at Cape Grim ensures large-scale (hemispheric) representativeness on interannual timescales, and we show differences from comparable records maintained by the University of Colorado (using National Oceanic and Atmospheric Administration flasks) and Scripps Institution of Oceanography. The long-term Southern Hemisphere relationships between δ13C and CO2 are explored for the seasonal and interannual variability in the Cape Grim record. The interannual relationship is characterized by distinct periods of δ13C leveling immediately following increased global CO2 growth rate.