ERBlox: Combining Matching Dependencies with Machine Learning for Entity Resolution

Entity resolution (ER), an important and common data cleaning problem, is about detecting data duplicate representations for the same external entities, and merging them into single representations. Relatively recently, declarative rules called "matching dependencies" (MDs) have been proposed for specifying similarity conditions under which attribute values in database records are merged. In this work we show the process and the benefits of integrating four components of ER: (a) Building a classifier for duplicate/non-duplicate record pairs built using machine learning (ML) techniques; (b) Use of MDs for supporting the blocking phase of ML; (c) Record merging on the basis of the classifier results; and (d) The use of the declarative language "LogiQL" -an extended form of Datalog supported by the "LogicBlox" platform- for all activities related to data processing, and the specification and enforcement of MDs.Comment: Final journal version, with some minor technical corrections. Extended version of arXiv:1508.0601

Area preservation in computational fluid dynamics

Incompressible two-dimensional flows such as the advection (Liouville) equation and the Euler equations have a large family of conservation laws related to conservation of area. We present two Eulerian numerical methods which preserve a discrete analog of area. The first is a fully discrete model based on a rearrangement of cells; the second is more conventional, but still preserves the area within each contour of the vorticity field. Initial tests indicate that both methods suppress the formation of spurious oscillations in the field.Comment: 14 pages incl. 3 figure

Mind the Gap - Issues in Overcoming the Information, Income, Wealth, and Supply Gaps Facing Potential Buyers of Affordable Homes

While the overall homeownership rate in the United States is at an all-time high, the gap between the ownership rates of low-income and higher-income households remains wide. In addition, homeownership rates in urban, low-income and minority communities lag behind. Lower-income families are constrained a lack of information about how to buy a home, by their inability to provide sufficient, stable income streams for debt service, by their lack of initial equity, and by their inability to find an home of adequate quality in a desirable location. This paper explores each of these constraints, or gaps, and potential solutions for each. We find addressing each of these gaps involves trade-offs, yet targeting the appropriate strategy for particular markets and populations may be able to help families become home owners. Information gaps are best addressed by programs that provide home buyer counseling and education. Federal funding and incentives for such programs have been declining throughout the last decade, however. Unless new homebuyers are well-prepared and supported, none of the sophisticated development and financial strategies will be successful. Income and wealth gaps are closely linked; bridging a wealth gap for a buyer, for example, may increase the buyer's income gap. While there are several strategies that seek to bridge these twin barriers, the most promising among them is the second mortgage. The supply gap is most pressing in faster-growing coastal cities, but is becoming a more significant constraint to homeownership nationally. Unfortunately, reliance on filtering and other traditional mechanisms for creating affordable homeownership opportunities has not proven effective in recent years. Serious consideration should be paid to new production programs and policies that can enhance the supply of affordable owner-occupied units in targeted areas. Overall, a menu of strategies exists, each being appropriate for targeted households in a given housing market context. More attention needs to be focused on this menu, rather than a one-size fits all strategy

Symmetric monoidal noncommutative spectra, strongly self-absorbing C∗C^*-algebras, and bivariant homology

Continuing our project on noncommutative (stable) homotopy we construct symmetric monoidal $\infty$-categorical models for separable $C^*$-algebras $\mathtt{SC^*_\infty}$ and noncommutative spectra $\mathtt{NSp}$ using the framework of Higher Algebra due to Lurie. We study smashing (co)localizations of $\mathtt{SC^*_\infty}$ and $\mathtt{NSp}$ with respect to strongly self-absorbing $C^*$-algebras. We analyse the homotopy categories of the localizations of $\mathtt{SC^*_\infty}$ and give universal characterizations thereof. We construct a stable $\infty$-categorical model for bivariant connective E-theory and compute the connective E-theory groups of $\mathcal{O}_\infty$-stable $C^*$-algebras. We also introduce and study the nonconnective version of Quillen's nonunital K'-theory in the framework of stable $\infty$-categories. This is done in order to promote our earlier result relating topological $\mathbb{T}$-duality to noncommutative motives to the $\infty$-categorical setup. Finally, we carry out some computations in the case of stable and $\mathcal{O}_\infty$-stable $C^*$-algebras.Comment: 26 pages; v2 revised in accordance with arXiv:1412.8370, corrections in Sections 3 and 4; v3 minor changes, to appear in J. Noncommut. Geo

Consistent phenological shifts in the making of a biodiversity hotspot: the Cape flora

Background The best documented survival responses of organisms to past climate change on short (glacial-interglacial) timescales are distributional shifts. Despite ample evidence on such timescales for local adaptations of populations at specific sites, the long-term impacts of such changes on evolutionary significant units in response to past climatic change have been little documented. Here we use phylogenies to reconstruct changes in distribution and flowering ecology of the Cape flora - South Africa's biodiversity hotspot - through a period of past (Neogene and Quaternary) changes in the seasonality of rainfall over a timescale of several million years. Results Forty-three distributional and phenological shifts consistent with past climatic change occur across the flora, and a comparable number of clades underwent adaptive changes in their flowering phenology (9 clades; half of the clades investigated) as underwent distributional shifts (12 clades; two thirds of the clades investigated). Of extant Cape angiosperm species, 14-41% have been contributed by lineages that show distributional shifts consistent with past climate change, yet a similar proportion (14-55%) arose from lineages that shifted flowering phenology. Conclusions Adaptive changes in ecology at the scale we uncover in the Cape and consistent with past climatic change have not been documented for other floras. Shifts in climate tolerance appear to have been more important in this flora than is currently appreciated, and lineages that underwent such shifts went on to contribute a high proportion of the flora's extant species diversity. That shifts in phenology, on an evolutionary timescale and on such a scale, have not yet been detected for other floras is likely a result of the method used; shifts in flowering phenology cannot be detected in the fossil record

Understanding the debate about policy space: from the WTO to EU FTAs

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