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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.
261

Exploring everyday musical imagery : an experience-sampling study.

Sherriff, Bronwyn Nadine 21 June 2011 (has links)
Psychological research regarding mental imagery is heterogeneous in nature owing to its internal nature. Mental imagery involving music is most simply defined as hearing music in the mind’s ear. Musical imagery (MI) is an understudied phenomenon particularly by means of non-experimental methods. This study investigated four dimensions of everyday MI: namely it’s content, nature, constancy and associated corporeal manifestations (for instance, foot-tapping, humming and so forth), via experience-sampling methods. Stage one of data collection involved a cross-sectional survey (n = 87) whereby participants provided retrospective self-reports concerning MI, pertinent demographic information, and particulars concerning their musical history. Stage two – implemented subsequent to piloting – utilised iterative sampling to illuminate the dimensions and descriptive facets of MI during everyday activities. Each participant (n = 16; 8 musicians; 8 non-musicians) was selected based on specific inclusion criteria, following stage one participation, and were invited to complete 21 questionnaires over seven days, receiving three SMS prompts per day. In terms of prevalence, MI was consistently experienced by participants, regardless of their musical background although musicians reported higher rates of MI occurrences. There was a statistically significant association between MI and musical training/experience (χ² = 6.35; d.f. = 1; p = .012). Furthermore, odds ratios suggested that the musicians demonstrated an 85% likelihood of experiencing MI as compared to the non-musicians (OR 1.85; CI 1.14 – 2.99). Daily exposure to music appeared to be an equally significant factor relating to every day MI incidences, particularly given the finding that the majority of participant’s MI episodes were familiar and recently heard.
262

Mental Imagery and Tracking

Bruzadin Nunes, Ugo 01 December 2018 (has links)
This study aimed to better understand visuomotor tracking and spatial visual imagery. 101 Participants performed four tasks: A Manual Tracking Task (MTT), in which participants mouse-tracked the path of a circle, sometimes with occlusion. A Multi-Object Tracking task (MOT), in which participants tracked several objects simultaneously. The Sussex Cognitive Styles Questionnaire (SCSQ), in which participants self-reported their experience with imagery. A Mental Rotation Task (MRT) in which participants mentally rotate Tetris-like objects. The results demonstrated a significant correlation between the technical/spatial subscale of the SCSQ and the occluded MTT, the MRT, the MOT but not the visible MTT. A multiple regression showed that occluded MTT and the MRT together significantly predicted the spatial/technical subscale of the SCSQ above visible MTT and MOT. These findings support the claim that the cognitive resources behind mental imagery may also be recruited during other tasks that arguably draw on the need for internal visualization.
263

Differences in Spatial Visualization Ability and Vividness of Spatial Imagery Between People With and Without Aphantasia

Crowder, Anita 01 January 2018 (has links)
Mathematics education researchers have examined the relationship between visualization and mathematics for decades (e.g., Arcavi, 2003; Bishop, 1991; Duval, 1999; Fennema & Tartre, 1985; Presmeg, 1986). Studies have linked spatial visualization ability, such as measured in mental rotation tasks, directly to mathematics self-efficacy (Pajares & Kranzler, 1995; Weckbacher & Okamoto, 2014), which in turn influences mathematics achievement (Casey, Nuttall, & Pezaris, 1997). With the important role that spatial visualization plays in learning mathematics, the recent identification of congenital aphantasia (Zeman, Dewar, & Della Sala, 2015), which is the lack of mental imagery ability, has raised new questions for mathematics education researchers. This study investigated the differences in mental rotation test performance and vividness of spatial imagery between people who have aphantasia and people who do not as a first step toward examining how aphantasia may affect mathematics learning and education. Results confirmed prior aphantasia research showing that there was no significant difference in mental rotation test performance between people with aphantasia and those without aphantasia, despite people with aphantasia reporting significantly lower vividness of spatial imagery. Results also showed that there was less difference in mental rotation test performance between the genders for people with aphantasia, while gender played a significant role in mental rotation test performance for people without aphantasia. People with aphantasia also reported lower self-efficacy in the arts than people without aphantasia. Implications of these results will be discussed within the context of current research, and possible directions for future research will be offered.
264

Arid land condition assessment and monitoring using mulitspectral and hyperspectral imagery.

Jafari, Reza January 2007 (has links)
Arid lands cover approximately 30% of the earth’s surface. Due to the broadness, remoteness, and harsh condition of these lands, land condition assessment and monitoring using ground-based techniques appear to be limited. Remote sensing imagery with its broad areal coverage, repeatability, cost and time-effectiveness has been suggested and used as an alternative approach for more than three decades. This thesis evaluated the potential of different remote sensing techniques for assessing and monitoring land condition of southern arid lands of South Australia. There were four specific objectives: 1) to evaluate vegetation indices derived from multispectral satellite imagery for prediction of vegetation cover; 2) to compare vegetation indices and field measurements for detecting vegetation changes and assessing land condition; 3) to examine the potential of hyperspectral imagery for discriminating vegetation components that are important in land management using unmixing techniques; and 4) to test whether spatial heterogeneity in land surface reflectance can provide additional information about land condition and effects of management on land condition. The study focused on Kingoonya and Gawler Soil Conservation Districts that were dominated by chenopod shrublands and low open woodlands over sand plains and dunes. The area has been grazed predominately by sheep for more than 100 years and land degradation or desertification due to overgrazing is evident in some parts of the region, especially around stock watering points. Grazing is the most important factor that influences land condition. Four full scenes of Landsat TM and ETM+ multispectral and Hyperion hyperspectral data were acquired over the study area. The imagery was acquired in dry seasons to highlight perennial vegetation cover that has an important role in land condition assessment and monitoring. Slope-based, distance-based, orthogonal transformation and plant-water sensitive vegetation indices were compared with vegetation cover estimates at monitoring points made by state government agency staff during the first Pastoral Lease assessments in 1991. To examine the performance of vegetation indices, they were tested at two scales: within two contrasting land systems and across broader regional landscapes. Of the vegetation indices evaluated, selected Stress Related Vegetation Indices using red, nearinfrared and mid-infrared bands consistently showed significant relationships with vegetation cover at both land system and landscape scales. Estimation of vegetation cover was more accurate within land systems than across broader regions. Total perennial and ephemeral plant cover was predicted best within land systems (R2=0.88), while combined vegetation, plant litter and soil cryptogam crust cover was predicted best at landscape scale (R2=0.39). The results of applying one of the stress related vegetation indices (STVI-4) to 1991 TM and 2002 ETM+ Landsat imagery to detect vegetation changes and to 2005 Landsat TM imagery to discriminate Land Condition Index (LCI) classes showed that it is an appropriate vegetation index for both identifying trends in vegetation cover and assessing land condition. STVI-4 highlighted increases and decreases in vegetation in different parts of the study area. The vegetation change image provided useful information about changes in vegetation cover resulting from variations in climate and alterations in land management. STVI-4 was able to differentiate all three LCI classes (poor, fair and good condition) in low open woodlands with 95% confidence level. In chenopod shrubland and Mount Eba country only poor and good conditions were separable spectrally. The application of spectral mixture analysis to Hyperion hyperspectral imagery yielded five distinct end-members: two associated with vegetation cover and the remaining three associated with different soils, surface gravel and stone. The specific identity of the image end-members was determined by comparing their mean spectra with field reflectance spectra collected with an Analytical Spectral Devices (ASD) Field Spec Pro spectrometer. One vegetation end-member correlated significantly with cottonbush vegetation cover (R2=0.89), distributed as patches throughout the study area. The second vegetation end-member appeared to map green and grey-green perennial shrubs (e.g. Mulga) and correlated significantly with total vegetation cover (R2=0.68). The soil and surface gravel and stone end-members that mapped sand plains, sand dunes, and surface gravel and stone did not show significant correlations with the field estimates of these soil surface components. I examined the potential of a spatial heterogeneity index, the Moving Standard Deviation Index (MSDI), around stock watering points and nearby ungrazed reference sites. One of the major indirect effects of watering points in a grazed landscape is the development around them of a zone of extreme degradation called a piosphere. MSDI was applied to Landsat red band for detection and assessment of these zones. Results showed watering points had significantly higher MSDI values than non-degraded reference areas. Comparison of two vegetation indices, the Normalized Difference Vegetation Index (NDVI) and Perpendicular Distance vegetation index (PD54), which were used as reference indices, showed that the PD54 was more sensitive than NDVI for assessing land condition in this perennial-dominated arid environment. Piospheres were found to be more spatially heterogeneous in land surface reflectance. They had higher MSDI values compared to non-degraded areas, and spatial heterogeneity decreased with increasing distance from water points. The study has demonstrated overall that image-based indices derived from Landsat multispectral and Hyperion hyperspectral imagery can be used with field methods to assess and monitor vegetation cover (and consequently land condition) of southern arid lands of South Australia in a quick and efficient way. Relationships between vegetation indices, end-members and field measurements can be used to estimate vegetation cover and monitor its variation with time in broad areas where field-based methods are not effective. Multispectral vegetation indices can be used to assess and discriminate ground-based land condition classes. The sandy-loam end-member extracted from Hyperion imagery has high potential for monitoring sand dunes and their movement over time. The MSDI showed that spatial heterogeneity in land surface reflectance can be used as a good indicator of land degradation. It differentiated degraded from nondegraded areas successfully and detected grazing gradients slightly better than widely used vegetation indices. Results suggest further research using these remote sensing techniques is warranted for arid land condition assessment and monitoring in South Australia. / http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1295218 / Thesis (Ph.D.) -- School of Earth and Environmental Science, 2007
265

Semi-automatic Road Extraction from Very High Resolution Remote Sensing Imagery by RoadModeler

Lu, Yao January 2009 (has links)
Accurate and up-to-date road information is essential for both effective urban planning and disaster management. Today, very high resolution (VHR) imagery acquired by airborne and spaceborne imaging sensors is the primary source for the acquisition of spatial information of increasingly growing road networks. Given the increased availability of the aerial and satellite images, it is necessary to develop computer-aided techniques to improve the efficiency and reduce the cost of road extraction tasks. Therefore, automation of image-based road extraction is a very active research topic. This thesis deals with the development and implementation aspects of a semi-automatic road extraction strategy, which includes two key approaches: multidirectional and single-direction road extraction. It requires a human operator to initialize a seed circle on a road and specify a extraction approach before the road is extracted by automatic algorithms using multiple vision cues. The multidirectional approach is used to detect roads with different materials, widths, intersection shapes, and degrees of noise, but sometimes it also interprets parking lots as road areas. Different from the multidirectional approach, the single-direction approach can detect roads with few mistakes, but each seed circle can only be used to detect one road. In accordance with this strategy, a RoadModeler prototype was developed. Both aerial and GeoEye-1 satellite images of seven different types of scenes with various road shapes in rural, downtown, and residential areas were used to evaluate the performance of the RoadModeler. The experimental results demonstrated that the RoadModeler is reliable and easy-to-use by a non-expert operator. Therefore, the RoadModeler is much better than the object-oriented classification. Its average road completeness, correctness, and quality achieved 94%, 97%, and 94%, respectively. These results are higher than those of Hu et al. (2007), which are 91%, 90%, and 85%, respectively. The successful development of the RoadModeler suggests that the integration of multiple vision cues potentially offers a solution to simple and fast acquisition of road information. Recommendations are given for further research to be conducted to ensure that this progress goes beyond the prototype stage and towards everyday use.
266

Semi-automatic Road Extraction from Very High Resolution Remote Sensing Imagery by RoadModeler

Lu, Yao January 2009 (has links)
Accurate and up-to-date road information is essential for both effective urban planning and disaster management. Today, very high resolution (VHR) imagery acquired by airborne and spaceborne imaging sensors is the primary source for the acquisition of spatial information of increasingly growing road networks. Given the increased availability of the aerial and satellite images, it is necessary to develop computer-aided techniques to improve the efficiency and reduce the cost of road extraction tasks. Therefore, automation of image-based road extraction is a very active research topic. This thesis deals with the development and implementation aspects of a semi-automatic road extraction strategy, which includes two key approaches: multidirectional and single-direction road extraction. It requires a human operator to initialize a seed circle on a road and specify a extraction approach before the road is extracted by automatic algorithms using multiple vision cues. The multidirectional approach is used to detect roads with different materials, widths, intersection shapes, and degrees of noise, but sometimes it also interprets parking lots as road areas. Different from the multidirectional approach, the single-direction approach can detect roads with few mistakes, but each seed circle can only be used to detect one road. In accordance with this strategy, a RoadModeler prototype was developed. Both aerial and GeoEye-1 satellite images of seven different types of scenes with various road shapes in rural, downtown, and residential areas were used to evaluate the performance of the RoadModeler. The experimental results demonstrated that the RoadModeler is reliable and easy-to-use by a non-expert operator. Therefore, the RoadModeler is much better than the object-oriented classification. Its average road completeness, correctness, and quality achieved 94%, 97%, and 94%, respectively. These results are higher than those of Hu et al. (2007), which are 91%, 90%, and 85%, respectively. The successful development of the RoadModeler suggests that the integration of multiple vision cues potentially offers a solution to simple and fast acquisition of road information. Recommendations are given for further research to be conducted to ensure that this progress goes beyond the prototype stage and towards everyday use.
267

Utilizing natural scene statistics and blind image quality analysis of infrared imagery

Kaser, Jennifer Yvonne 09 December 2013 (has links)
With the increasing number and affordability of image capture devices, there is an increasing demand to objectively analyze and compare the quality of images. Image quality can also be used as an indicator to determine if the source image is of high enough quality to perform analysis on. When applied to real world scenarios, use of a blind algorithm is essential since a flawless reference image typically is unavailable. Recent research has shown promising results in no reference image quality utilizing natural scene statistics in the visual image space. Research has also shown that although the statistical profiles vary slightly, there are statistical regularities in IR images as well which would indicate that natural scene statistical models may be able to be applied. In this project, I will analyze BRISQUE quality features of IR images and determine if the algorithm can successfully be applied to IR images. Additionally, in order to validate the usefulness of these techniques, the BRISQUE quality features are analyzed using a detection algorithm to determine if they can be used to predict conditions which may cause missed detections. / text
268

Simma med huvudet : En studie kring simmares visualiseringsförmåga och användning

Runeke, Josephine January 2015 (has links)
Syftet med studien var att undersöka vid vilken situation som simmare använder visualisering mest och varför samt simmarnas visualiseringsförmåga. I studien deltog 278 simmare (15-30 år) i den kvantitativa delen och 3 simmare (17-23 år) i den kvalitativa delen av studien. De instrument som tillämpades till den kvantitativa delen var en konstruktion av SIAM och IPIES som tillsammans mäter idrottares visualiseringsförmåga och användning. Till den kvalitativa delen användes en semikonstruerad intervjumall. Resultaten från studien visade att det fanns några statistisk signifikant skillnad mellan högpresterade och lågpresterande simmare i visualiseringsförmåga. Resultaten visade att simmarena använder visualiseringen för att tänka positiv och fokusera samt förberedda sig inför nästa tävling. Dessutom sågs en tendens från den kvalitativa studien att högpresterade simmare hade bättre visualiseringsförmåga än lågpresterade och de använde visualiserings för att minska nervositet samt förbättra en prestation. Rekommendation med studien var att introducera och uppmuntra simmare att redan i lägre åldrar för visualisering som ett kompletterande träningsform till simningen, för att på så sätt förbättra simmares förberedelser inför tävling samt motivera till högre prestationsnivåer. / The aim of the study was to investigate at which situation swimmers use imagery the most, why, and the swimmers imagery ability. The study involved 278 swimmers (15-30 years) in the quantitative study, and 3 swimmers (17-23 years) in the qualitative part of the study. The instruments that were applied to the quantitative part were a construction of SIAM and IPIES which together measure the athlete's imagery ability´s and uses. For the qualitative part, a semi constructed interview was applied. The result of the study showed that there were statistically significant differences between high-performance and low-performance swimmers in imagery ability. The results showed that the use imagery to think positive and focused and prepare themselves before the next race. There was also a tendency from the qualitative study that high-performance swimmers had better imagery ability than lowperformance and used imagery to reduce nervousness and to improve the performance. Recommendation from the study was to introduce and encourage swimmers in lower ages to imagery as a complementary exercise for swimming, to improve the swimmer's preparation for the competition and motivate to higher performance levels
269

Imagery as a Skills Training Technique for Alcoholics

Chadwell, Carrell Morgan 12 1900 (has links)
Alcoholism is a major health problem, and current methods of treatment have been only partially successful. One treatment approach is to teach coping skills for dealing with problematic situations. This study was designed to investigate the effectiveness of imagery techniques in teaching coping skills. There were two major objectives of this study. The first objective was to determine whether covert skills training would produce positive changes in alcoholics in terms of their effectiveness in responding to stressful situations, their self-concept, and selected personality characteristics. The second objective was to determine whether alcoholics subjectively experience the imagery approach as beneficial. The statistical design also evaluated whether the effectiveness of the treatment fluctuated as a function of age, education, chronicity of alcohol problem, number of rehabilitation attempts, and environmental support as measured by the presence of a family or job awaiting the alcoholic's return.
270

Non-parametric edge detection in speckled imagery

Giovanny Giron Amaya, Edwin 31 January 2008 (has links)
Made available in DSpace on 2014-06-12T18:02:43Z (GMT). No. of bitstreams: 2 arquivo4052_1.pdf: 1926198 bytes, checksum: a394edbf4f303fa7b25af920df83cf25 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2008 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Este trabalho propõe uma técnica não-paramétrica para detecção de bordas em imagens speckle. As imagens SAR ("Synthetic aperture Radar"), sonar, B-ultrasound e laser são corrompidas por um ruído não aditivo chamado speckle. Vários modelos estatísticos foram propostos para desrever este ruído, levando ao desenvolvimento de técnicas especiais para melhoramento e análise de imagens. A distribuição G0 é um modelo estatístico que consegue descrever uma ampla gama de áreas, como, por exemplo, em dados SAR, pastos (lisos), florestas (rugosos) e áreas urbanas (muito rugosos). O objetivo deste trabalho é estudar ténicas alternativas na detecção de imagens speckled, tomando como ponto de partida Gambini et al. (2006, 2008). Um novo detector de borda baseado no teste de Kruskal Wallis é proposto. Os nossos resultados numéricos mostram que esse detector é uma alternativa atraente ao detector de M. Gambini, que é baseado na função de verossimilhançaa. Neste trabalho fornecemos evidências de que a técnica de M. Gambini pode ser substituída om sucesso pelo método Kruskal Wallis. O ganho reside em ter um algoritmo 1000 vezes mais rápido, sem omprometer a qualidade dos resultados

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