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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Navigation and the ageing driver

Burns, Peter C. January 1997 (has links)
This thesis examines issues surrounding route navigation. Emphasis is on the problems of elderly motorists. Elderly drivers have been said to avoid unfamiliar routes and may have wayfinding problems, but the extent and nature of these problems have not previously been investigated. This thesis aims to determine how drivers plan their routes and find their way in transit. It also seeks to investigate the prevalence and types of driver wayfinding problems, as well as their causes, consequences and psychological implications. Lastly, this thesis aims to measure the impact wayfinding problems have on mobility and identify potential solutions. Three studies were conducted, the first was a preliminary investigation into route navigation issues. Focus group discussions explored driver wayfinding strategies and problems. The second study consisted of a postal questionnaire survey of motorists. Results suggested the most common route planning method was to read a map and take notes of the route. For wayfinding on major roads, drivers stated a preference for road number, place name, and junction information. In cities, they requested information about street names, lane position and landmarks. More drivers under 60 years of age preferred landmark information than did elderly drivers. The most frequent wayfinding errors were: missing a road sign, choosing the wrong lane, and detecting a sign or a turn too late to respond safely. The most frequently reported causes of wayfinding errors were: insufficient, inaccurate, obscured or non-existent traffic signs; inattention or distraction; inaccurate directions; darkness; busy roads and road repairs. As hypothesised, elderly drivers reported more difficulties with wayfinding and this was related to reduced mobility. The third study explored different means of presenting route guidance information. An experiment was conducted to investigate the safety and efficiency of visual, auditory (speech) or a combined visual-auditory display. Driver performance, visual behaviour, subjective mental workload and preferences were recorded. For displaying simple route guidance information to drivers across ages, it is recommended that verbal displays be used as a primary source of guidance information and visual displays as a redundant reminder.
22

Measuring the shape of time-varying objects

Monks, Tim Peter January 1995 (has links)
This thesis describes the first implementation of a colour encoded structured light (CESL) range-finder capable of measuring the shape of time-varying or moving surfaces. The system is shown to have mean square accuracies of better than 0.5mm when measuring the shape of the human mouth during continuous speech sampled at 50Hz, and better than 0.2mm when measuring static objects of similar dimensions. In order to sample range at video-rates, the images of the scene to be digitised are stored on video tape. This allows the image processing to be performed off-line so the sampling rate of the system only depends on the frame-rate of the video equipment used. The work was motivated by the need to acquire information on mouth shape for acoustics of speech experiments so that the results presented are for measurements of mouth shape and objects relating to the field. The reasons for producing a new system, and the choice of CESL are discussed. The work covers the entire implementation of the range-finder, including code and slide design, feature extraction, feature interpretation, calibration and 3D reconstruction, and performance evaluation. A modification on the Blackman and Tukey classical power density spectrum (PDS) estimator was used for feature extraction which was shown to perform better than other techniques evaluated. The accuracy of detected features and the probability that they were not spurious was determined, based on the feature confidence output by the PDS estimator. Detected features were tracked to produce segments, and encoded as a directed acyclic graph (DAG) which was then matched with the original code sequence using a fast but sub-optimal technique. An existing camera calibration technique was used which was extended to include a second step for projector calibration. The projector model used was linear, had the correct number of degrees of freedom, and was particular to our stripe system.
23

Towards a Genome Reverse Compiler

Warren, Andrew S. 29 November 2007 (has links)
The Genome Reverse Compiler (GRC) is an annotation tool for prokaryotic genomes. Its name and philosophy are based on analogy with a high-level programming language compiler. In this analogy, the genome is a program in a certain low-level language that humans cannot understand. Given the sequence of any prokaryotic genome, GRC produces its corresponding "high-level program"--its annotation. GRC works in a completely automatic manner, using standard input and output formats. The goal is to provide an open-source, easy-to-run, very efficient annotation program. / Master of Science
24

Benefit-finding and coherence in the narratives of women with HIV

Cruise, Ruth 12 March 2016 (has links)
Women with HIV are particularly at risk for poor mental health outcomes and for a number of traumatic experiences, including sexual abuse. Benefit-finding is the ability to generate positive outcomes resulting from trauma and is important for women with HIV, since it is motivated by distress and has demonstrated health benefits among individuals with trauma and/or medical conditions. Qualitative narrative measures, especially those that reflect life stories, are most likely to assess benefit-finding. Narrative coherence, which reflects how well a life story is told, may be associated with benefit-finding and with better mental health outcomes. The current study hypothesized that greater psychological distress (depressive symptoms [CESD] and quality of life [QOL]) HIV disease progression (HIV viral load [VL] and CD4 count), and sexual abuse, and lower levels of substance use, assessed with self-report measures at multiple visits over an average of 10 years (M = 10.05 years, SD = 3.47 years), would predict benefit-finding and coherence, coded from autobiographical narratives of 99 women with HIV (91% African American, mean age = 44.78 years, SD = 8.85 years) who were participants in the Women's Interagency HIV Study, Chicago site. Greater benefit-finding and coherence were also hypothesized to predict higher resilience coded in narratives cross-sectionally and higher CD4 count, QOL, and antiretroviral medication (HAART) adherence, and lower VL and CESD 6 months following narrative administration (M = 5.64 months, SD = 1.49 months). Partial correlations and multiple hierarchical linear and logistic regressions controlling for demographics and other relevant covariates indicated that hypotheses were partially supported. History of sexual abuse predicted greater benefit-finding only. There were no significant longitudinal predictors of narrative coherence. Benefit-finding was positively related to narrative coherence and resilience (cross-sectionally) and positively predictive of HAART adherence, greater likelihood of CD4 >= 350 and undetectable VL, and fewer depressive symptoms 6 months later. Coherence was not significantly related to post-narrative outcomes. Results suggest that benefit-finding has numerous health benefits among women with HIV and that interventions for this population should draw on and enhance benefit-finding, a potential strength in facing adverse circumstances.
25

Use of multi-spectral imagery and LiDar data to quantify compositional and structural characteristics of vegetation in red-cockaded woodpecker (Picoides borealis) habitat in North Carolina

Carney, Joelle Marie 08 August 2009 (has links)
This study evaluated habitat parameters for the red-cockaded woodpecker (RCW; Picoides borealis) on three tracts in Hoke County, North Carolina. Multi-spectral imagery was used to classify shadow, non-vegetation, herbaceous, hardwoods, and loblolly and longleaf pine trees. Field data were collected for image classification training and validation. Overall classification accuracy for separating hardwood from pine trees, was 80.8%. When separating longleaf (Pinus palustris Mill.) and loblolly (Pinus taeda L.) pine from hardwoods the accuracy was 73.7%. Field-based height/diameter relationships were applied to LiDAR-identified trees to predict diameter classes. Due to differences in management regimes and site conditions, each tract had different majority pine diameter classes. Average height, diameter, basal area, and stem density per plot were reported from matched, unmatched, and total LiDAR trees to field trees. Differences between the height, diameter, basal area, and stem density values occurred between the matched and unmatched LiDAR- and field-identified trees.
26

NavNets: 3D Path-planning system

Gwosdz, Thomas January 2019 (has links)
The current state of 3D path-planning leaves room for improvement. To navigate a 3D environment, techniques which were developed for 2D navigation are used and slightly adapted to generate convincing motion. However, these techniques often constrict the motion to a single plane. This constriction is not only a limitation, but also increases the error. We created a new method to compute a path in a 3D world without a planar constraint. We will discuss the computation of a Navigation Volume Network (NavNet), and how it finds a path. A NavNet is the 3D generalization of NavMeshes, and holds boundary and connection information which is utilized when planning a path for motion. Similar to how NavMeshes allow path-planning by simplifying the ground meshes, the NavNet simplifies the search space by approximating the 3D world through sampling. / Thesis / Master of Applied Science (MASc)
27

Development of a Single-Channel Direction Finding Algorithm

Harter, Nathan M. 04 May 2007 (has links)
A radio direction finding (DF) system uses a multiple-element antenna array coupled with one or more receivers to estimate the direction-of-arrival (DOA) of a targeted emitter using characteristics of the signal received at each of the antennas in the array. In general, DF systems can be classified both by the number of receivers employed as well as which characteristics of the received signal are used to produce the DOA estimate, such as the signal's amplitude, phase, or time of arrival. This work centers on the development and implementation of a novel single-channel direction finding system based on the differential phase of the target signal received by a uniform circular antenna array with a commutative switch. The algorithm is called the PLL DF Method and differs from older single-channel DF techniques in that it is a digital algorithm intended for implementation on a software-defined radio (SDR) platform with a custom-designed antenna array and RF switching network. It uses a bank of parallel software PLLs to estimate the phase of the signal received at each element of the multi-antenna array. Theses estimated phase values are then fed to a specialized signal processing block that estimates the DOA of the received signal. This thesis presents the details of the initial version of the PLL algorithm which was used to produce a proof-of-concept system with an eight-element circular array. It then discusses various technical challenges uncovered in the initial implementation and presents numerous enhancements to the algorithm to overcome these challenges, such as a modification to the PLL model to offer increased estimator robustness in the presence of a frequency offset between the transmitter and receiver, revisions of the software implementation to reduce the algorithm's processing requirements, and the adaptation of the DF algorithm for use with a 16-element circular array. The performance of the algorithm with these modifications under various conditions are simulated to investigate their impact on the DOA estimation process and the results of their implementation on an SDR are considered. / Master of Science
28

Scalability of Stepping Stones and Pathways

Venkatachalam, Logambigai 30 May 2008 (has links)
Information Retrieval (IR) plays a key role in serving large communities of users who are in need of relevant answers for their search queries. IR encompasses various search models to address different requirements and has introduced a variety of supporting tools to improve effectiveness and efficiency. "Search" is the key focus of IR. The classic search methodology takes an input query, processes it, and returns the result as a ranked list of documents. However, this approach is not the most effective method to support the task of finding document associations (relationships between concepts or queries) both for direct or indirect relationships. The Stepping Stones and Pathways (SSP) retrieval methodology supports retrieval of ranked chains of documents that support valid relationships between any two given concepts. SSP has many potential practical and research applications, which are in need of a tool to find connections between two concepts. The early SSP "proof-of-concept" implementation could handle only 6000 documents. However, commercial search applications will have to deal with millions of documents. Hence, addressing the scalability limitation becomes extremely important in the current SSP implementation in order to overcome the limitations on handling large datasets. Research on various commercial search applications and their scalability indicates that the Lucene search tool kit is widely used due to its support for scalability, performance, and extensibility features. Many web-based and desktop applications have used this search tool kit to great success, including Wikipedia search, job search sites, digital libraries, e-commerce sites, and the Eclipse Integrated Development Environment (IDE). The goal of this research is to re-implement SSP in a scalable way, so that it can work for larger datasets and also can be deployed commercially. This work explains the approach adopted for re-implementation focusing on scalable indexing, searching components, new ways to process citations (references), a new approach for query expansion, document clustering, and document similarity calculation. The experiments performed to test the factors such as runtime and storage proved that the system can be scaled up to handle up to millions of documents. / Master of Science
29

Positive experiences in dementia care-giving: findings from the IDEAL programme

Quinn, Catherine, Toms, G., Rippon, I., Nelis, S.M., Henderson, C., Morris, R.G., Rusted, J.M., Thom, J.M., van den Heuvel, E., Victor, C., Clare, L. 01 July 2022 (has links)
Yes / There is a growing evidence base that identifying positive experiences in providing care can have a beneficial influence on carer wellbeing. However, there is a need to better understand what carers identify as the positive aspects of care-giving. The aim of this study is to explore the satisfying aspects of providing care to people with dementia. This study utilised Time 1 data from 1,277 carers of people in the mild-to-moderate stages of dementia taking part in the IDEAL (Improving the experience of Dementia and Enhancing Active Life) cohort study. Responses from 900 carers who answered the open-ended question ‘What is your greatest satisfaction in caring for your relative/friend?’ were analysed using thematic analysis. From the responses, 839 carers detailed satisfactions. Eight themes were identified, pertaining to three groups of beneficiaries: carers, people with dementia and the dyad. Perceived benefits for carers included identifying aspects of personal growth, seeing glimpses of the person, feeling they were making a difference and doing their duty. For the person with dementia, these included retaining independence, receiving good quality care and being happy. Dyadic benefits concerned the continuation of the relationship between carer and person with dementia. The findings highlight the need to take a dyadic approach when conceptualising positive experiences in providing care. Further research is needed to understand the role these positive experiences play and to develop interventions. Professionals working with carers should identify and validate these experiences. / ‘Improving the experience of Dementia and Enhancing Active Life: living well with dementia. The IDEAL study’ was funded jointly by the Economic and Social Research Council (ESRC) and the National Institute for Health and Care Research (NIHR) (grant number ES/L001853/2); ‘Improving the experience of Dementia and Enhancing Active Life: a longitudinal perspective on living well with dementia. The IDEAL-2 study’ is funded by the Alzheimer's Society (grant number 348, AS-PR2-16-001)
30

An Investigation of Training in Creative Problem Solving and its Relationship to Affective and Effective Idea Generation of Entrepreneurial Learners

Leach, Charles Edward 01 January 2009 (has links)
A significant proportion of the population engages in entrepreneurial behavior but many ventures do not survive beyond startup thus decreasing the pool of entrepreneurs available to contribute to the economy. Opportunity recognition is central to entrepreneurial success and the improper delineation of opportunities is cited as a leading cause of venture failure. There is a logical link between creativity, innovation and entrepreneurship. The goal of the researcher in this study was to explore the relationships between CPS training and the generation of entrepreneurial ideas. The investigation studied the relationship of training in creative problem solving (CPS) to the opportunity identification skills of entrepreneurial learners. It was hypothesized that CPS training would positively impact attitudes relating to divergent thinking, would increase the number of opportunities identified and would increase the quality of opportunities identified. The tutorial was targeted at novice entrepreneurs who were in the initial stages of identifying an opportunity. Quality at this early stage in the venture formation process was defined as the degree to which the idea meshed with the learner's interests and passions and the extent to which they possessed prior experience. An experimental research design was used and participants were randomly assigned to either a treatment or control group. There were no statistically significant differences in composition between the treatment and control groups. There were statistically significant differences found in one of the two divergent thinking constructs - the tendency to make premature evaluations. Two measures of ideational fluency were tested. No statistically significant differences were found in fluency for the post-test/pre-test measure within the treatment group or between the treatment and control group. Statistically significant differences were found in the number of unique ideas generated post-test/pre-test (within the treatment group and between the treatment and control group) and statistically significant differences were also found in the unique bottles measure (within group only). There were no statistically significant differences found in the 4 quality measures. The findings in this study have the potential to strengthen the link between the enhancement of creative performance and the generation of entrepreneurial ideas. The research also holds the potential to provide practical guidelines for use of instructional techniques for training in opportunity recognition but also more broadly across the continuum of entrepreneurship education. The objective of the training was to increase the size and the quality of the venture idea pool that entrepreneurs draw from when initiating ventures.

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