1,720,995 research outputs found
Heuristic Based Optimisation of Pavement Management Scheduling
Full text linkThe issue of effectively scheduling pavement maintenance and rehabilitation treatments over a multi-year planning horizon plagues road authorities around the world with the significance of this issue being amplified by both an ageing pavement network and the trend towards insufficient fund allocation. The scope of the problem can be quantified as follows: if only a single treatment is able to be applied to each individual road segment in a single year, then the total number of possible programmed maintenance and rehabilitation schedule alternatives for a moderate-sized network of 1,000 road segments, with eight different treatments possible, over a twenty year anaysis period is ((1.0 × 103)8)20 = 1.0 × 10480. Assuming that a computer can build and evaluate 100 complete maintenance and rehabilitation schedules a second, to identify the optimal schedule for this 1,000 segment road network would take 3.17 × 10471 years. The overall goal of this study is to investigate the benefits of applying modern heuristic optimisation techniques to the problem of pavement main- tenance and rehabilitation scheduling over a multi-year planning horizon. To address this goal, a four stage approach was utilised using a real road network with real pavement condition data as the test benchmark.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)Griffith School of EngineeringScience, Environment, Engineering and TechnologyFull Tex
Non-Iterative Three-Dimensional Reconstruction and Representation
No full textThree-dimensional reconstruction algorithms generate 3D data from twodimensional
image or video data. The current focus of this research area is
on iterative algorithms such as: feature matching/RANSAC, Iterative Closest
Point, and other non-linear optimization strategies. These strategies tend
to fail in scenes with few features or scenes which contain feature confusion.
In 2D image registration research, feature matching is dominant but closed
form solution based Fourier registration techniques have been proven to outperform
them with increased robustness to under textured scenes and image
noise. This thesis investigates the application of Fourier Volume Registration
to 3D reconstruction. Results are compared between Fourier Volume
Registration, and several current techniques both quantitatively and qualitatively
to nd out if Fourier based techniques outperform iterative ones.
Results show that the Fourier Volume Registration Technique often outperforms
other methods in terms of minimizing registration error prior to
optimization. Furthermore it is a closed form solution which works well with parallel processing architectures. 3D data representations for 3D reconstruction
data are also explored to improve storage and transmission of such data.
Many current methods make use of Signed Distance Functions, volumetric
occupancy grids or octrees. In the work presented here, lossy octree compression
is analysed to pave the way for new storage and transmission rates
of e ciency. A novel method, called the Plane-Tree, is proposed based on
the octree compression method. This Plane-Tree data structure was inspired
by work completed in the author's honours thesis. When compared to the
original octree data structure, the Plane-Tree is optimal in terms of compression
performance. The ndings presented on both the Fourier Volume
Registration method and the Plane-Tree indicate improvements over existing
methods.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Info & Comm TechScience, Environment, Engineering and TechnologyFull Tex
Facilitators and Barriers to User Adoption of Electronic Health Record Systems
No full textInformation Technology (IT) applications have brought massive changes in healthcare and health providers have shifted from paper-based systems to computerized ones. The electronic medical record (EMR) and personal health record (PHR) are good examples of the application of IT in healthcare settings. Despite the enormous benefits of the available applications in healthcare, the adoption of EMR in primary care has been identified at 38.4 percent in the U.S., in Denmark, almost 62 percent of doctors use EMR, while only 55 percent of Australian physicians apply EMR systems (Sicotte et al. 2016; Venkatesh et al. 2011). Furthermore, with regard to the PHR system, the Australian government’s development of a national PHR system (personally controlled electronic health record (PCEHR) system) in 2010 was a part of their national e-health strategy to overcome common challenges such as medication errors, fragmented sources of health information, repetition of tests, an increase in chronic illness, workforce resource constraints, and individuals’ changing expectations of technology. The Australian government expected that 500,000 users would register at the first release of the national PHR system; however, only 400,000 users have signed up to this system and of those, many registered but their records remain empty.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of information and Communication TechnologyScience, Environment, Engineering and TechnologyFull Tex
Structural Alignments for Similarity Detection in Bioinformatics
No full textThis thesis addresses problems involving structural alignments for similarity detection between entities. In the general computational context, a structural alignment is defined as an optimization problem where representative inputs are assigned to relative positions subject to the minimization of some objective function. The output is an inferred relationship based upon the resultant value of the objective function, and/or the arrangement of aligned positions. Two bioinformatics similarity detection applications were used as case studies within this work, the structural alignment of biomolecular proteins and the document similarity detection problem in biomedical literature.
The structural alignment of protein biomolecules involves generating residue pair correspondences of maximal overlap with minimal geometric divergence using each protein’s set of three-dimensional atomic coordinates. As protein structure decides its functionality, similarity in structure usually implies similarity in function. During the investigation of this structural alignment problem, it became apparent that a fast and approximate asymmetric linear sum assignment algorithm was required. Accordingly, a new heuristic algorithm, Asymmetric Greedy Search (AGS), was developed. Extensive computational experiments using a range of model graphs demonstrated the effectiveness of the algorithm. In addition, a new type of deterministic model graph that is suitable for reproducible benchmarking of these types of algorithms was also developed. Incorporating AGS, a new non-sequential protein structure alignment method, SPalignNS, was then developed. As compared to existing methods, SPalignNS achieved greater alignment accuracy with commonly used protein alignment test datasets, and also achieved the highest agreement with manually curated reference alignments.
The document similarity detection problem is a fundamental application of natural language processing, and constitutes the basis of information retrieval systems. Document matching systems for locating relevant literature have mostly relied on methods developed over a decade ago, largely due to the unavailability of a common evaluation framework. A database of relevance annotations for over 180,000 PubMed-listed document pairs was developed with a subsequent application in training a sentence-based transferred learning model, HuBERT (Hierarchical PubMed BERT). When applied to relevant biomedical literature searches in PubMed, the new HuBERT method produced superior results compared to those attained by the baseline methods from existing document matching systems.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Info & Comm TechScience, Environment, Engineering and TechnologyFull Tex
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Content-Based Retrieval of Digital Video
No full textIn the next few years consumers will have access to large amounts of video and image data either
created by themselves with digital video and still cameras or by having access to other image
and video content electronically. Existing personal computer hardware and software has not been
designed to manage large quantities of multimedia content. As a result, research in the area of
content-based video retrieval (CBVR) has been underway for the last fifteen years. This research
aims to improve CBVR by providing an accurate and reliable shape-colour representation and
by providing a new 3D user interface called DomeWorld for the efficient browsing of large video
databases. Existing feature extraction techniques designed for use in large databases are typically simple
techniques as they must conform to the limited processing and storage constraints that are exhibited
by large scale databases. Conversely, more complex feature extraction techniques provide higher level
descriptions of the underlying data but are time consuming and require large amounts of
storage making them less useful for large databases. In this thesis a technique for medium to high level
shape representation is presented that exhibits efficient storage and query performance. The
technique uses a very accurate contour detection system that incorporates a new asymmetry edge
detector which is shown to perform better than other contour detection techniques combined with
a new summarisation technique to efficiently store contours. In addition, contours are represented
by histograms further reducing space requirements and increasing query performance. A new type
of histogram is introduced called the fuzzy histogram and is applied to content-based retrieval
systems for the first time. Fuzzy histograms improve the ranking of query results over non-fuzzy
techniques especially in low bin-count histogram configurations. The fuzzy contour histogram
approach is compared with an exhaustive contour comparison technique and is found to provide
equivalent or better results. A number of colour distribution representation techniques were
investigated for integration with the contour histogram and the fuzzy HSV histogram was found to
provide the best performance. When the colour and contour histograms were integrated less overall bins
were required as each histogram compensates for the other’s weaknesses. The result is that only a quarter of the bins
were required than either colour or contour histogram alone further reducing query times and
storage requirements. This research also improves the user experience with a new user interface called
DomeWorld that uses three-dimensional translucent domes. Existing user interfaces are either designed for
image databases, for browsing videos, or for browsing large non-multimedia data sets. DomeWorld
is designed to be able to browse both image and video databases through a number of innovative
techniques including hierarchical clustering, radial space-filling layout of nodes, three-dimensional
presentation, and translucent domes that allow the hierarchical nature of the data to be viewed
whilst also seeing the relationship between child nodes a number of levels deep.
A taxonomy of existing image, video, and large data set user interfaces is presented and the
proposed user interface is evaluated within the framework. It is found that video database user
interfaces have four requirements: context and detail, gisting, clustering, and integration of video
and images. None of the 27 evaluated user interfaces satisfy all four requirements. The DomeWorld
user interface is designed to satisfy all of the requirements and presents a step forward in CBVR
user interaction. This thesis investigates two important areas of CBVR, structural indexing and user
interaction, and presents techniques which advance the field. These two areas will become very important in
the future when users must access and manage large collections of image and video content.Thesis (PhD Doctorate)Doctor of Philosophy (PhD)School of Information TechnologyScience, Environment, Engineering and TechnologyFull Tex
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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