Conceptual document modelling and retrieval

This paper presents the main current theoretical issues in Information Retrieval. The principles of conceptual modelling, as they have emerged in the database area, are presented and their application to document modelling in order to enhance document retrieval is discussed. Finally, the main features of the MULTOS project are presented and critically reviewed confronting them with the requirements which have been identified during the general discussion on document conceptual modelling for information retrieval.     

IBM RISC System/6000: architecture and performance

The IBM RISC System/6000, a superscalar microprocessor, is presented. The architecture of this processor has its instruction set specifically designed for a superscalar machine containing three independent units-branch, fixed-point, and floating-point. The design also emphasizes high-performance floating-point operations. The design principles are to offer maximum overlap of the three functional units, avoid dead cycles, and define instructions that can (for the most part) be completed at a rate of one per cycle. The branch cycle, fixed- and floating-point units, cache management, and performance are described. Benchmark results are given     

The glass fibre-polymer interface: II—Work of fracture and shear stresses

Pull-out experiments have been carried out on single production fibres under carefully controlled conditions. Four parameters were determined. The interfacial yield stresses, of about 9–14 MPa, were very much smaller than the shear strengths of the bulk polymers in the case of an epoxy, whether post-cured or not, and a non-post-cured polyester. Values for the work of fracture of the interface varied from 140 to 300 Jm^?2, and again were less than those of the polymer. Interface failure sometimes took place in the epoxy rather than at the fibre surface, whereas with the polyester it always took place at the fibre surface. After interface failure, pull-out was governed by friction, with maximum shear stresses of 7–10 MPa for polyester, and 21–34 MPa for epoxy, the higher values being obtained for the post-cured resins. Average frictional shear stresses were sometimes less than a half of the maximum shear stress, indicating that the fibre Poisson's shrinkage was playing an important role in the pull-out process. A silicone release agent reduced the frictional shear stresses to 2·5 MPa, with both resins.     

Location of structural sections from within a highly distorted complex line drawing

Complex and highly distorted line drawings are produced by subjects attempting the Rey Complex Figure test, a clinical test of neuropsychological assessment. However, the marking scheme conventionally employed can be subjective and unreliable. In this paper, the first stages in automating this scoring system are investigated using a robust technique to locate a reduced set of scoring sections and a knowledge-based system that employs spatial metrics and fuzzy approximation techniques. Testing the technique using clinical data produced encouraging results that support the argument that this is a feasible approach for implementing a fully automated system, and that in its current state, can be immediately applied in a semi-automated system.     

Mobile positioning using wireless networks: possibilities and fundamental limitations based on available wireless network measurements

Positioning in wireless networks is mainly used for safety, gaming, and commercial services. It is expected to increase in popularity when emergency call services become mandatory as well as with the advent of more advanced location-based services and mobile gaming. In this article, we discuss and illustrate the possibilities and fundamental limitations associated with mobile positioning based on available wireless network measurements. The possibilities include a sensor fusion approach and model-based filtering, while the fundamental limitations provide hard bounds on the accuracy of position estimates, given the information in the measurements in the most favorable situation. The focus of this article is to illustrate the relation between performance requirements, such as those stated by the Federal Communications Commission (FCC), and the available measurements. Specific issues on accuracy limitation in each measurement, such as synchronization and multipath problems, are briefly commented upon. A geometrical example, as well as a realistic example adopted from a cell planning tool, are used for illustration.     

Comparison between photocatalytic ozonation and other oxidation processes for the removal of phenols from water

Photocatalytic ozonation (1O₃ + VUV + TiO₂), ozonation (O₃), catalytic ozonation (O₃ + TiO₂), ozone photolysis (O₃ + VUV), photocatalysis (TiO₂ + VUV) and photolysis (VUV) have been compared in terms of formation of intermediates, extent of, mineralization (TOC, COD, chloride, nitrate) and kinetics in the aqueous treatment of three phenols (phenol, p‐chlorophenol and p‐nitrophenol). In all cases, photocatalytic ozonation led to lower degradation times for chemical oxygen demand and total organic carbon removal. Intermediates formed were similar in the different oxidation systems with some exceptions. They can be classified into three different types: polyphenols (resorcinol, catechol, hydroquinone), unsaturated carboxylic acids (maleic and fumaric acids) and saturated carboxylic acids (glyoxylic, formic and oxalic acids). First order kinetic equations have been checked for the oxidation processes studied in the case of the parent compound. Rate constants of these systems have also been calculated. Copyright © 2005 Society of Chemical Industry