Multimodal discourse on online newspaper home pages: A social-semiotic perspective

In a short space of time, online newspapers have emerged to play an important role in the institutional construction of ‘news’ and the mass mediation of information. The home pages of online newspapers feature short verbal texts, and communicate using language, image, layout, colour, and other semiotic resources: they communicate multimodally. This thesis examines the multimodal discourse of three English-language online newspapers: the Bangkok Post (Thailand), the English-language edition (translated from Chinese) of the People’s Daily (China), and the Sydney Morning Herald (Australia). Between February, 2002 and April, 2006, three data collections were made (February-April, 2002; September-November, 2005; January-April, 2006) using a five-day ‘constructed week’ method. The main corpus was 15 home pages from each newspaper (five per collection per newspaper), but the total corpus (including other pages from each newspaper) was 603 web pages. Two senior editors (one each from the Bangkok Post and the Sydney Morning Herald) were interviewed. The multimodal discourse of the home pages was analysed using tools from Systemic Functional Multimodal Discourse Analysis (SF-MDA), and a ‘visual grammar’ of home pages building on the work of Kress & van Leeuwen (1996) was developed. In addition, a rank scale for online newspapers was proposed, and limitations of applying the tool of rank scale to this corpus were identified. An emerging genre - the headline-plus-lead-plus-hyperlink newsbite - was identified, and the design of newsbites on the home page of the Sydney Morning Herald and the evolution of their design over time was analysed. The use of images on the home pages in the corpus was analysed, and the increasing use of thumbnail images in the Sydney Morning Herald - particularly close-up thumbnails of faces - was investigated in further depth. The visual design of online newspaper home pages and the news texts appearing on them are an evolution of print news genres and their design practices. Newsbites and headline-only newsbits are verbally short, so the authors of newspaper home pages are forced to rely increasingly on visual communication in order to position stories and readers, and to communicate the values of the news institution on the home page as mediated by the screen. Thumbnail images are evolving as a new form of punctuation on some home pages, and this may be a short-lived, or an emerging historical trend in the development of punctuation, at least in online environments. Overall, online newspaper home pages are tending towards shorter texts, which communicate in novel ways. These short texts cannot communicate the values and ideology of news institutions in the way that extended verbal texts have done for centuries, yet this function of news texts remains important to the construction and maintenance of a readership, and therefore crucial to the home page of a newspaper. As a result, news institutions express values visually in their design of newspaper home pages. As readers become familiar with the meanings of online news design, they become adept at reading and understanding short stories within these multimodally-construed frames of reference. Ideology is increasingly fragmented on shorter timescales, but expressed over longer timescales in a hypermedia environment that affords and extends many of the pre-existing multimodal features of print newspaper discourse

Vehicle classification using neural networks

In this work vehicle classification by neural networks is investigated, three types of neural networks are investigated and the influence of their parameters and some normalization methods on the correct classification score. This report is constructed as follows: The first part is a description of the vehicle measurements, the data storage and the processing of the vehicle data. The second part is an introduction to neural networks and an description of some network types. It also discusses the preprocessing of the vehicle footprints and the construction of the training and test set. Finally, the main results for each neural network are presented.Applied SciencesElectrical EngineeringTelecommunications and Traffic-Control Systems Grou

De rekentijd van verschillende transformatiemethoden voor lusdetectorsignalen

Vanwege de behoefte het steeds drukker wordende verkeer met electronische hulpmiddelen te begeleiden zijn ook in Nederland op een aantal wegen signaleringssystemen in gebruik genomen. Men hoopt zo de wegen efficiënter te kunnen gebruiken en de verkeersveiligheid te vergroten. Bij het laboratorium voor verkeersbegeleidingssystemen is in dat kader al geruime tijd een Automatisch Incident Detectie (AID) systeem in ontwikkeling, met drie meetpunten op rijksweg A13. De metingen worden verricht m.b.v. lusdetectoren. Als een voertuig een lus passeert dan wordt de zogenaamde handtekening, de verstemming van de lus, gemeten. Zo’n handtekening is karakteristiek voor een voertuig. Door nu een bepaalde transformatie op de handtekening uit te voeren, kan men met de verkregen resultaten voertuigen sneller trachten te herkennen. Als dat namelijk mogelijk is kan elk voertuig individueel gevolgd worden waardoor sneller en nauwkeuriger een incident gedetecteerd kan worden.Applied SciencesElectrotechniekTelecommunicatie- en Verkeersbegeleidingssysteme

Method in Computer Aided Digital Mammography

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Automated assessment of low contrast sensitivity for CT systems using a model observer

Purpose: Low contrast sensitivity of CT scanners is regularly assessed by subjective scoring of low contrast detectability within phantom CT images. Since in these phantoms low contrast objects are arranged in known fixed patterns, subjective rating of low contrast visibility might be biased. The purpose of this study was to develop and validate a software for automated objective low contrast detectability based on a model observer. Methods: Images of the low contrast module of the Catphan 600 phantom were used for the evaluation of the software. This module contains two subregions: the supraslice region with three groups of low contrast objects (each consisting of nine circular objects with diameter 2-15 mm and contrast 0.3, 0.5, and 1.0%, respectively) and the subslice region with three groups of four circular objects each (diameter 3-9 mm; contrast 1.0%). The software method offered automated determination of low contrast detectability using a NPWE (nonprewhitening matched filter with an eye filter) model observer for the supraslice region. The model observer correlated templates of the low contrast objects with the acquired images of the Catphan phantom and a discrimination index d' was calculated. This index was transformed into a proportion correct (PC) value. In the two-alternative forced choice (2-AFC) experiments used in this study, a PC >= 75% was proposed as a threshold to decide whether objects were visible. As a proof of concept, influence of kVp (between 80 and 135 kV), mAs (25-200 mAs range) and reconstruction filter (four filters, two soft and two sharp) on low contrast detectability was investigated. To validate the outcome of the software in a qualitative way, a human observer study was performed. Results: The expected influence of kV, mAs and reconstruction filter on image quality are consistent with the results of the proposed automated model. Higher values for d' (or PC) are found with increasing mAs or kV values and for the soft reconstruction filters. For the highest contrast group (1%), PC values were fairly above 75% for all object diameters > 2 mm, for all conditions. For the 0.5% contrast group, the same behavior was observed for object diameters > 3 mm for all conditions. For the 0.3% contrast group, PC values were higher than 75% for object diameters > 6 mm except for the series acquired at the lowest dose (25 mAs), which gave lower PC values. In the human observer study similar trends were found. Conclusions: We have developed an automated method to objectively investigate image quality using the NPWE model in combination with images of the Catphan phantom low contrast module. As a first step, low contrast detectability as a function of both acquisition and reconstruction parameter settings was successfully investigated with the software. In future work, this method could play a role in image reconstruction algorithms evaluation, dose reduction strategies or novel CT technologies, and other model observers may be implemented as well. (c) 2011 American Association of Physicists in Medicine. [DOI: 10.1118/1.3577757