Logical segmentation for article extraction in digitized old newspapers

Newspapers are documents made of news item and informative articles. They are not meant to be red iteratively: the reader can pick his items in any order he fancies. Ignoring this structural property, most digitized newspaper archives only offer access by issue or at best by page to their content. We have built a digitization workflow that automatically extracts newspaper articles from images, which allows indexing and retrieval of information at the article level. Our back-end system extracts the logical structure of the page to produce the informative units: the articles. Each image is labelled at the pixel level, through a machine learning based method, then the page logical structure is constructed up from there by the detection of structuring entities such as horizontal and vertical separators, titles and text lines. This logical structure is stored in a METS wrapper associated to the ALTO file produced by the system including the OCRed text. Our front-end system provides a web high definition visualisation of images, textual indexing and retrieval facilities, searching and reading at the article level. Articles transcriptions can be collaboratively corrected, which as a consequence allows for better indexing. We are currently testing our system on the archives of the Journal de Rouen, one of France eldest local newspaper. These 250 years of publication amount to 300 000 pages of very variable image quality and layout complexity. Test year 1808 can be consulted at plair.univ-rouen.fr.Comment: ACM Document Engineering, France (2012

A weak MLMC scheme for L\'evy-copula-driven SDEs with applications to the pricing of credit, equity and interest rate derivatives

This paper develops a novel weak multilevel Monte-Carlo (MLMC) approximation scheme for L\'evy-driven Stochastic Differential Equations (SDEs). The scheme is based on the state space discretization (via a continuous-time Markov chain approximation) of the pure-jump component of the driving L\'evy process and is particularly suited if the multidimensional driver is given by a L\'evy copula. The multilevel version of the algorithm requires a new coupling of the approximate L\'evy drivers in the consecutive levels of the scheme, which is defined via a coupling of the corresponding Poisson point processes. The multilevel scheme is weak in the sense that the bound on the level variances is based on the coupling alone without requiring strong convergence. Moreover, the coupling is natural for the proposed discretization of jumps and is easy to simulate. The approximation scheme and its multilevel analogous are applied to examples taken from mathematical finance, including the pricing of credit, equity and interest rate derivatives.Comment: 35 page

Geopolymer ultrahigh performance concrete: Material and performance

During the last two decades, considerable progress has been made in the development of ultra-high-performance concrete (UHPC) with ordinary Portland cement (OPC). UHPC represents a major development step over high performance concrete (HPC), through the achievement of very high compressive strength (over 20,000 psi or 140 MPa) and superior durability due to very low permeability compared to high-performance concrete; in some cases, fibers are included to achieve improved ductility. Despite these performance advantages, deployment of Portland cement-based UHPC has been slow, in part due to the relatively high compared to that of conventional concrete components. In addition, the higher content of Portland cement in UHPC, high temperature steam curing, and use of relatively large amounts of superplasticizers increase the cost and CO2 footprint. Geopolymer-based UHPCs have the potential for significant advantages over comparable OPC-based materials. We have developed a range of low-cost, low-CO2 footprint, geopolymer UHPC (GUHPC) formulations. The main characteristics of these GUHPCs include: 1) Increased homogeneity by excluding aggregates \u3e9.5mm, 2) Increased packing density through use of micro- and nano-particles, 3) Very low water-to-binder ratio through chemically tailored activator compositions and use of intensive mixing; 4) Composite binders yielding hybrid calcium aluminosilicate hydrate (C-A-S-H) and alkali aluminosilicate hydrate (A-A-S-H) gels to improve product properties; and 5) Regulation of set times using a very effective inorganic retarder. Please click Additional Files below to see the full abstract

Observations on the potatoe, and a remedy for the potatoe plague. In two parts. Containing a history of the potatoe, its cultivation, and uses, also a treatise on the potatoe malady, its origin and appearances in different countries, a view of various theories concerning it, with the remedies proposed, and an inquiry into the causes producing the disease, with directions for staying its further progress.

Printed wrappers.Advertisement: 4 p. (at end)Mode of access: Internet