Separating decision tree complexity from subcube partition complexity

The subcube partition model of computation is at least as powerful as decision trees but no separation between these models was known. We show that there exists a function whose deterministic subcube partition complexity is asymptotically smaller than its randomized decision tree complexity, resolving an open problem of Friedgut, Kahn, and Wigderson (2002). Our lower bound is based on the information-theoretic techniques first introduced to lower bound the randomized decision tree complexity of the recursive majority function. We also show that the public-coin partition bound, the best known lower bound method for randomized decision tree complexity subsuming other general techniques such as block sensitivity, approximate degree, randomized certificate complexity, and the classical adversary bound, also lower bounds randomized subcube partition complexity. This shows that all these lower bound techniques cannot prove optimal lower bounds for randomized decision tree complexity, which answers an open question of Jain and Klauck (2010) and Jain, Lee, and Vishnoi (2014).Comment: 16 pages, 1 figur

Les échanges commerciaux de la colonie laurentienne avec la Grande-Bretagne, 1760-1850 : L’exemple des importations de produits textiles et métallurgiques

Le port de Québec a joué un rôle majeur dans l’important commerce colonial transatlantique avec les métropoles française et britannique. L’historiographie canadienne a depuis longtemps mis l’accent sur le volet exportation des ressources naturelles de ces échanges, tant les fourrures que les produits du bois, mais a rencontré des obstacles à cerner la place des importations des produits autres que les alcools et certaines denrées taxées. Se fondant sur un dépouillement et une analyse statistique critique des importants registres de la douane britanniques (Archives nationales du Royaume-Uni, séries CUST), cet article fait ressortir la prédominance des produits industriels britanniques, essentiellement les textiles, ainsi que d’une multitude de produits métallurgiques, alimentaires et autres reflétant tout l’éventail des milliers de produits arrivés sur le marché de consommation canadien de 1760 jusqu’à 1850. Il amorce dans deux cas (textiles et métallurgie) une étude plus approfondie de la composition de ces importations et de leurs retombées sur la production locale, tant artisanale qu’industrielle. Globalement, il en ressort aussi que la valeur des importations surpasse nettement celle des exportations pour cette période, une conclusion surprenante et controversée.Under both the French and British regimes, the Port of Quebec played a major role in the colonial trade between Canada and the mother country. Canadian historiography has long focused on the exportation of natural resources, mainly furs and wood products. But limitations in available sources have made it more difficult to understand the importance of imports, aside from taxable items like alcohol and certain other commodities. This article is based on a statistical analysis of key British customs records (CUST series at the Public Record Office). It underscores the central importance of British industrial products, mainly textiles, along with a multitude of metallurgical products, foodstuffs and other items which made up the full range of the thousands of imported products which made their way onto the Canadian consumer market between 1760 and 1850. The article also undertakes a closer analysis of the composition of two categories of imports (textiles and metallurgical products) and their impact on local production, both artisanal or industrial. Overall, the data show that the value of imports clearly surpassed that of exports during the period of study, a surprising and controversial conclusion

NOTE: Description of the male of Syrmoptera mixtura (Hulstaert, 1924) (Papilionoidea: Lycaenidae: Theclinae) in Northern DRC

No abstrac

Alien Registration- Desloges, Edward (Van Buren, Aroostook County)

https://digitalmaine.com/alien_docs/33090/thumbnail.jp

Flood energy dissipation in anabranching channels

This study examines the character of developing anabranched channel networks on the River Wear, north England using metre-scale aerial LiDAR. DSM-DTM interpretation reveals a well-developed vegetation structure and a locally diverse terrain, dominated by an interlinked channel network split by low elevation depositional areas with the gross morphology of the reach resembling that of a strongly active meandering / wandering channel suggesting that an anabranching network may develop within systems that were initially active meandering and wandering, evolving in line with floodplain vegetative succession. Utilisation of the LiDAR DEM in the hydrological component of the CAESAR-Lisflood (version 1.4) morpho-dynamic model has generated local hydraulic variable estimates through the anabranched reaches for a range of flows. These data clearly demonstrate how elevated flows are transferred out of the primary channel and distributed along the interconnected secondary channel network, creating a diverse set of hydraulic environments. Areas between the channels rapidly become inundated as flows increase, dissipating flow energy. Shear stress estimates throughout the study site reveal a generally reduced ability to mobilise sediments and erode channel margins, in comparison to a single-thread reach immediately downstream. Anabranched secondary channels appear to operate in disequilibrium and act predominantly as aggradational zones, although with some evidence of scour at channel bifurcation and confluence points. It would appear that the topographic character of anabranching sites efficiently manages flood flow energy, activating secondary channels and low elevation areas to distribute flood flows. These findings contrast with the hydraulic data from an adjacent single-thread reach, characterised by flood flows concentrated in-channel creating a high erosive potential. We propose that anabranching rivers could play an important role in natural flood and sediment management in many UK river systems

Saint-Pierre-sur-Dives – Abbaye Notre-Dame : restitution d’un pavement médiéval

Date de l'opération : 2007 (EX) Inventeur(s) : Desloges Jean (SRA) Jusqu’en 1921, le sanctuaire de l’église abbatiale s’ornait d’un pavement en carreaux de terre cuite émaillée attribué au XIIIe s. À cette date, l’état d’usure justifia le transfert des meilleurs carreaux dans la salle capitulaire où ils furent rassemblés sur une plateforme en béton. Récemment, le projet de restauration de ladite salle capitulaire posa à nouveau le problème du devenir du pavement. Celui-ci, bien que réduit au..