1,720,975 research outputs found
A correspondence framework for surface matching algorithms
No full textComputer vision tasks such as three dimensional (3D) registration, 3D modelling, and 3D object recognition are becoming more and more useful in industry, and have application such as reverse CAD engineering, and robot navigation. Each of these applications use correspondence algorithms as part of their processes. Correspondence algorithms are required to compute accurate mappings between artificial surfaces that represent actual objects or scenes. In industry, inaccurate correspondence is related to factors such as expenses in time and labour, and also safety. Therefore, it is essential to select an appropriate correspondence algorithm for a given surface matching task. However, current research in the area of surface correspondence is hampered by an abundance of applications specific algorithms, and no uniform terminology of consistent model for selecting and/or comparing algorithms.\ud
\ud
\ud
\ud
This dissertation presents a correspondence framework for surface matching algorithms. The framework is a conceptual model that is implementable. It is designed to assist in the analysis, comparison, development, and implementation of correspondence algorithms, which are essential tasks when selecting or creating an algorithm for a particular application. \ud
\ud
\ud
\ud
The primary contribution of the thesis is the correspondence framework presented as a conceptual model for surface matching algorithms. The model provides a systematic method for analysing, comparing, and developing algorithms. The dissertation demonstrates that by dividing correspondence computation into five stages: region definition, feature extraction, feature representation, local matching, and global matching, the task becomes smaller and more manageable. It also shows that the same stages of different algorithms are directly comparable. Furthermore, novel algorithms can be created by simply connecting compatible stages of different algorithms. Finally, new ideas can be synthesised by creating only the stages to be tested, without developing a while new correspondence algorithm.\ud
\ud
\ud
\ud
The secondary contribution that is outlined is the correspondence framework presented as a software design tool for surface matching algorithms. The framework is shown to reduce the complexity of implementing existing algorithms within the framework. This is done by encoding algorithms in a stage-wise procedure, whereby an algorithm is separated into the five stages of the framework. The software design tool is shown to validate the integrity of restructuring existing algorithms within it, and also provide an efficient basis for creating new algorithms.\ud
\ud
\ud
\ud
The third contribution that is made is the specification of a quality metric for algorithms comparison. The metric is used to assess the accuracy of the outcomes of a number of correspondence algorithms, which are used to match a wide variety of input surface pairs. The metric is used to demonstrate that each algorithm is application specific, and highlight the types of surfaces that can be matched by each algorithm. Thus, it is shown that algorithms that are implemented within the framework can be selected for particular surface correspondence tasks. \ud
\ud
\ud
\ud
\ud
\ud
The final contribution made is this dissertation is the expansion of the correspondence framework beyond the surface matching domain. The correspondence framework is maintained in its original form, and is used for image matching algorithms. Existing algorithms from three image matching applications are implemented and modified using the framework. It is shown how the framework provides a consistent means and uniform terminology for developing both surface and image matching algorithms.\ud
\ud
\ud
\ud
In summary, this thesis presents a correspondence framework for surface matching algorithms. The framework is general, encompassing a comprehensive set of algorithms, and flexible, expanding beyond surface matching to major image matching applications
Technical report : acoustic analysis of the natural environment
No full textThis technical report is concerned with one aspect of environmental monitoring—the detection and analysis of acoustic events in sound recordings of the environment. Sound recordings offer ecologists the potential advantages of cheaper and increased sampling. An acoustic event detection algorithm is introduced that outputs a compact rectangular marquee description of each event. It can disentangle superimposed events, which are a common occurrence during morning and evening choruses. Next, three uses to which acoustic event detection can be put are illustrated. These tasks have been selected because they illustrate quite different modes of analysis: (1) the detection of diffuse events caused by wind and rain, which are a frequent contaminant of recordings of the terrestrial environment; (2) the detection of bird calls using the spatial distribution of their component events; and (3) the preparation of acoustic maps for whole ecosystem analysis. This last task utilises the temporal distribution of events over a daily, monthly or yearly cycle
Frank and Stein : from research scientist to creative writer (a screenplay and exegesis)
No full textThe screenplay, “Perfect Blood” (Frank and Stein), is the first two-hour episode of a two-part television miniseries Frank and Stein. This creative work is a science fiction story that speculates on the future of Western nations in a world where petroleum is scarce. A major theme that has been explored in the miniseries is the tension between the advantages and dangers of scientific progress without regard to human consequences. “Perfect Blood” (Frank and Stein) was written as part of my personal creative journey, which has been the transformation from research scientist to creative writer. In the exegetical component of this thesis, I propose that a key challenge for any scientist writing science fiction is the shift from conducting empirical research in a laboratory-based situation to engaging in creative practice research. During my personal creative journey, I found that a predominant difficulty in conducting research within a creative practice-led paradigm was unleashing my creativity and personal viewpoint, practices that are frowned upon in scientific research. The aim of the exegesis is to demonstrate that the transformative process from science to art is not neat and well-structured. My personal creative journey was fraught with many ‘wrong’ turns. However, after reflecting on the experience, I realise that every varied piece of research that I undertook allowed me to progress to the next stage, the next draft of Frank and Stein. And via the disorder of the creative process, a screenplay finally emerged that was both structured and creative, which are equally essential elements in screenwriting
Analysing environmental acoustic data through collaboration and automation
No full textMonitoring environmental health is becoming increasingly important as human activity and climate change place greater pressure on global biodiversity. Acoustic sensors provide the ability to collect data passively, objectively and continuously across large areas for extended periods. While these factors make acoustic sensors attractive as autonomous data collectors, there are significant issues associated with large-scale data manipulation and analysis. We present our current research into techniques for analysing large volumes of acoustic data efficiently. We provide an overview of a novel online acoustic environmental workbench and discuss a number of approaches to scaling analysis of acoustic data; online collaboration, manual, automatic and human-in-the loop analysis
Einflüsse auf das Ernährungsverhalten von Kleinkindern unter Bedingungen sozialer Ungleichheit – Anforderungen an eine lebensweltorientierte Soziale Arbeit
Get PDFThe correspondence framework for 3D surface matching algorithms
No full textBeyond the inherent technical challenges, current research into the three dimensional surface correspondence problem is hampered by a lack of uniform terminology, an abundance of application specific algorithms, and the absence of a consistent model for comparing existing approaches and developing new ones. This paper addresses these challenges by presenting a framework for analysing, comparing, developing, and implementing surface correspondence algorithms. The framework uses five distinct stages to establish correspondence between surfaces. It is general, encompassing a wide variety of existing techniques, and flexible, facilitating the synthesis of new correspondence algorithms. This paper presents a review of existing surface correspondence algorithms, and shows how they fit into the correspondence framework. It also shows how the framework can be used to analyse and compare existing algorithms and develop new algorithms using the framework's modular structure. Six algorithms, four existing and two new, are implemented using the framework. Each implemented algorithm is used to match a number of surface pairs. Results demonstrate that the correspondence framework implementations are faithful implementations of existing algorithms, and that powerful new surface correspondence algorithms can be created. (C) 2004 Elsevier Inc. All rights reserved
Intrinsic correspondence using statistical signature-based matching for 3D surfaces
No full textA wide variety of applications including object recognition and terrain mapping, rely upon automatic three dimensional surface modelling. The automatic correspondence stage of the modelling process has proven challenging. Intrinsic correspondence methods determine matching segments of partially overlapping 3D surfaces, by using properties intrinsic to the surfaces. These methods do not require initial relative orientations to begin the matching procedures. Hence, intrinsic methods are well-suited for automatic matching
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
