Shape deformation in continuous map generalization

Given a collection of regions on a map, we seek a method of continuously altering the regions as the scale is varied. This is formalized and brought to rigor as well-defined problems in homotopic deformation. We ask the regions to preserve topology, area-ratios, and relative position as they change over time. A solution is presented using differential methods and computational geometric techniques. Most notably, an application of this method is used to provide an algorithm to obtain cartograms.

Nanoparticle-functionalized porous polymer monolith detection elements for surface-enhanced Raman scattering

The use of porous polymer monoliths functionalized with silver nanoparticles is introduced in this work for high-sensitivity surface-enhanced Raman scattering (SERS) detection. Preparation of the SERS detection elements is a simple process comprising the synthesis of a discrete polymer monolith section within a silica capillary, followed by physically trapping silver nanoparticle aggregates within the monolith matrix. A SERS detection limit of 220 fmol for Rhodamine 6G is demonstrated, with excellent signal stability over a 24 h period. The capability of the SERS-active monolith for label-free detection of biomolecules was demonstrated by measurements of bradykinin and cytochrome c. The SERS-active monoliths can be readily integrated into miniaturized micrototal-analysis systems for online and label-free detection for a variety of biosensing, bioanalytical, and biomedical applications.     

Effects of Anti-Oxidant Migration on Friction and Wear of C/C Aircraft Brakes

The surfaces of carbon-carbon (C/C) aircraft brakes are usually coated with anti-oxidant to protect them from oxidation. These surfaces do not include the friction surfaces since it is known that when anti-oxidant get onto the friction surface, the friction coefficient decreases. The anti-oxidant migration (AOM), however, happens during processing, heat treatment and application. In this study, phosphorus based anti-oxidants inhibited 3-D C/C aircraft brake system was investigated. The effects of their migration on friction and wear in the 3-D C/C brakes were revealed by sub-scale dynamometer tests and microscopic analysis. Dynamometer results showed that when AOM occurred, both landing and taxi coefficients decreased in humid environment and the wear was slightly lowered. Microscopic study showed that under high humidity conditions there was no formation of the friction film.     

Automated self-service modeling: predictive analytics as a service

Research into service provision and innovation is becoming progressively more important as automated service-provision via the web matures as a technology. We describe a web-based targeting platform that uses advanced dynamic model building techniques to conduct intelligent reporting and modeling. The impact of the automated targeting services is realized through a knowledge base that drives the development of predictive model(s). The knowledge base is comprised of a rules engine that guides and evaluates the development of an automated model-building process. The template defines the model classifier (e.g., logistic regression, multinomial logit, ordinary least squares, etc.) in concert with rules for data filling and transformations. Additionally, the template also defines which variables to test (“include” rules) and which variables to retain (“keep” rules). The “final” model emerges from the iterative steps undertaken by the rules engine, and is utilized to target, or rank, the best prospects. This automated modeling approach is designed to cost-effectively assist businesses in their targeting activities—independent of the firm’s size and targeting needs. We describe how the service has been utilized to provide “targeting services” for a small to medium business direct marketing campaign, and for direct sales-force targeting in a larger firm. Empirical results suggest that the automated modeling approach provides superior “service” in terms of cost and timing compared to more traditional manual service provision.     

Designing to Facilitate Browsing: A Look Back at the Hyperties Workstation Browser

Since browsing hypertext can present a formidable cognitive challenge, user interface design plays a major role in determining acceptability. In the Unix workstation version of Hyperties, a research-oriented prototype, we focussed on design features that facilitate browsing. We first give a general overview of Hyperties and its markup language. Customizable documents can be generated by the conditional text feature that enables dynamic and selective display of text and graphics. In addition we present: — an innovative solution to link identification: pop-out graphical buttons of arbitrary shape.

— application of pie menus to permit low cognitive load actions that reduce the distraction of common actions, such as page turning or window selection.

— multiple window selection strategies that reduce clutter and housekeeping effort. We preferred piles-of-tiles, in which standard-sized windows were arranged in a consistent pattern on the display and actions could be done rapidly, allowing users to concentrate on the contents.

     

Non-targeted analysis of tea by hydrophilic interaction liquid chromatography and high resolution mass spectrometry

Tea is the second most consumed beverage in the world and its consumption has been associated with numerous potential health benefits. Factors such as fermentation methods, geographical origin and season can affect the primary and secondary metabolite composition of tea. In this study, a hydrophilic interaction liquid chromatography (HILIC) method coupled to high resolution mass spectrometry in both positive and negative ionisation modes was developed and optimised. The method when combined with principal component analysis to analyse three different types of tea, successfully distinguished samples into different categories, and provided evidence of the metabolites which differed between them. The accurate mass and high resolution attributes of the mass spectrometric data were utilised and relative quantification data were extracted post-data acquisition on 18 amino acids, showing significant differences in amino acid concentrations between tea types and countries. This study highlights the potential of HILIC chromatography combined with non-targeted mass spectrometric methods to provide a comprehensive understanding of polar metabolites in plant extracts.     

Phase Stability in the Mo-Ti-Zr-C System via Thermodynamic Modeling and Diffusion Multiple Validation

Alloys in the Mo-rich corner of the Mo-Ti-Zr-C system have found broad applications in non-oxidizing environments requiring structural integrity well beyond 1273 K (1000 °C). Alloys such as TZM (Mo-0.5Ti-0.08Zr-0.03C by weight %) and TZC (Mo-1.2Ti-0.3Zr-0.1C by weight) owe much of their high temperature strength and microstructural stability to MC and M₂C carbide phases. In turn, the stability of the respective carbides and the subsequent mechanical behavior of the alloys are strongly dependent on the alloying additions and thermal history. A CALPHAD-based thermodynamic modeling approach is employed to develop a quaternary thermodynamic database for the Mo-Ti-Zr-C system. The thermodynamic database thus developed is validated with diffusion multiple experiments and the validated database is exercised to elucidate the effects of alloying and thermal history on the phase equilibrium in Mo-rich alloys.     

TLM modeling of a probe‐coupled cylindrical cavity based on compact wire model in the cylindrical mesh

This article describes an implementation of a compact wire model into the three‐dimensional transmission‐line matrix (TLM) cylindrical mesh for the purpose of an efficient analysis of probe‐coupled cylindrical microwave cavity devices. Because of a cylindrical grid structure and empirical nature of the compact model, this implementation has to take into account a change of wire model parameters with a variable cross section of the TLM nodes through which a wire conductor passes. The model accuracy has been experimentally verified and compared with the corresponding results reached by the TLM method based on a rectangular grid in order to consider its advantages. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

Using Neural Networks to predict HFACS unsafe acts from the pre-conditions of unsafe acts

Abstract

Human Factors Analysis and Classification System (HFACS) is based upon Reason’s organizational model of human error which suggests that there is a ‘one to many’ mapping of condition tokens (HFACS level 2 psychological precursors) to unsafe act tokens (HFACS level 1 error and violations). Using accident data derived from 523 military aircraft accidents, the relationship between HFACS level 2 preconditions and level 1 unsafe acts was modelled using an artificial neural network (NN). This allowed an empirical model to be developed congruent with the underlying theory of HFACS. The NN solution produced an average overall classification rate of ca. 74% for all unsafe acts from information derived from their level 2 preconditions. However, the correct classification rate was superior for decision- and skill-based errors, than for perceptual errors and violations.

Practitioner Summary: A model to predict unsafe acts (HFACS level 1) from their preconditions (HFACS level 2) was developed from the analysis of 523 military aircraft accidents using an artificial NN. The results could correctly predict approximately 74% of errors.