Segui questo link per vedere altri tipi di pubblicazioni sul tema: Vision loss.
Tesi sul tema "Vision loss"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 saggi (tesi di laurea o di dottorato) per l'attività di ricerca sul tema "Vision loss".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi le tesi di molte aree scientifiche e compila una bibliografia corretta.
1
Chalmers, Richard Michael. "Studies of mitochondrial DNA and other factors in the aetiology of Leber's hereditary optic neuropathy and multiple sclerosis". Thesis, University of Oxford, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337542.
Testo completo
2
Barnet, Belinda English Media & Performing Arts Faculty of Arts & Social Sciences UNSW. "Lost in the archive: vision, artefact and loss in the evolution of hypertext". Publisher:University of New South Wales. English, Media, & Performing Arts, 2004. http://handle.unsw.edu.au/1959.4/44384.
Testo completoAbstract (sommario):
How does one write the history of a technical machine? Can we say that technical machines have their own genealogies, their own evolutionary dynamic? The technical artefact constitutes a series of objects, a lineage or a line. At a cursory level, we can see this in the fact that technical machines come in generations - they adapt and adopt characteristics over time, one suppressing the other as it becomes obsolete. It is argued that technics has its own evolutionary dynamic, and that this dynamic stems neither from biology nor from human societies. Yet 'it is impossible to deny the role of human thought in the creation of technical artefacts' (Guattari 1995, p. 37). Stones do not automatically rise up into a wall - humans 'invent' technical objects. This, then, raises the question of technical memory. Is it humans that remember previous generations of machines and transfer their characteristics to new machines? If so, how and where do they remember them? It is suggested that humans learn techniques from technical artefacts, and transfer these between machines. This theory of technical evolution is then used to understand the genealogy of hypertext. The historical differentiations of hypertext in different technical systems is traced. Hypertext is defined as both a technical artefact and also a set of techniques: both are a part of this third milieu, technics. The difference between technical artefact and technical vision is highlighted, and it is suggested that technique and vision change when they are externalised as material artefact. The primary technique traced is association, the organisational principle behind the hypertext systems explored in the manuscript. In conclusion, invention is shown to be an act of exhumation, the transfer and retroactiviation of techniques from the past. This thesis presents an argument for a new model of technical evolution, a model which claims that technics constitutes its own dynamic, and that this dynamic exceeds human evolution. It traces the genealogy of hypertext as a set of techniques and as series of material artefacts. To create this geneaology I draw on interviews conducted with Douglas Engelbart, Ted Nelson and Andries van Dam, as well as a wide variety of primary and secondary resources.
3
Cao, Yilong. "A novel loss function to train classifiers". Thesis, University of Sheffield, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.632413.
Testo completo
4
Bryer, Alan. "Pseudotumor cerebri (with special reference to visual loss)". Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/26342.
Testo completoAbstract (sommario):
AIMS OF STUDY: 1. To analyse the patients . who have been treated at Groote Schuur Hospital over the last seven years for Pseudotumor Cerebri. 2. To document the clinical features of this group of patients. 3. To determine the visual prognosis of this group. 4. To assess the forms of treatment that have been used in this group. 5. To review the literature with regard to: a) a comparison of the results of other studies with the present one. b) the pathophysiology of the condition. c) treatment of the syndrome. d) the visual prognosis of the syndrome.
5
Lundström, Linda. "Wavefront Aberrations and Peripheral Vision". Doctoral thesis, KTH, Tillämpad fysik, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4385.
Testo completoAbstract (sommario):
Failing eyesight causes a dramatic change in life. The aim of this project is to help people with large central visual field loss to better utilize their remaining vision. Central visual field loss means that the person has to rely on peripheral vision since the direct vision is lost, often due to a dysfunctional macula. In these cases, a full restoration of vision would require replacement or repair of the damaged retinal tissue, which is not yet possible. Instead, the present study seeks to improve peripheral vision by enhancing the image quality on the remaining functional part of the retina by optical corrections. The off-axis optics of the human eye often suffers from large optical errors, which together with the lower sampling density of the retina explain the limited visual function in the periphery. The dominating aberrations are field curvature and oblique astigmatism, which induce an effective eccentric refractive error. However, the irregular character of the aberrations and the limited neural function in the periphery will make it difficult to find the optimal refractive correction; the conventional subjective refraction, for example, is not suitable for subjects with large central visual field loss. Within the work of this thesis a Hartmann-Shack wavefront sensor has been constructed for oblique aberration measurements. Wavefront sensing is an objective method to assess detailed information about the optical errors in the human eye. Theory and methods have been developed to allow accurate off-axis measurements of the large aberrations, enable eccentric fixation, and handle the elliptical pupil. The study has mainly concentrated on sphero-cylindrical correction of peripheral vision. Peripheral resolution and detection acuity thresholds have been evaluated for seven subjects with central visual field loss and ten control subjects with normal vision. Five of the subjects with field loss showed improved resolution acuity with eccentric refractive correction compared to their habitual central correction, whereas little change was found for the control subjects. These results demonstrate that correction of peripheral optical errors can be beneficial to people with large central visual field loss in situations where a normal healthy eye does not experience any improvements. In conclusion, it is worthwhile to investigate the peripheral refractive errors in low-vision rehabilitation of central visual field loss and prescribe spectacle correction when those errors are large.QC 20100809
6
Smith, Andrew Fraser. "An appraisal of the cost of ophthalmic care for persons with diabetes in Nova Scotia, Canada and their willingness-to-pay for diabetic retinopathy screening". Thesis, University of London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391676.
Testo completo
7
Hall, Courtney D. "Physical Functioning, Fall Risk and Mobility in Individuals with Vision Loss". Digital Commons @ East Tennessee State University, 2017. https://dc.etsu.edu/etsu-works/2708.
Testo completo
8
Niehorster, Diederick Christian. "Influence of hemianopic visual field loss on motor control". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45861699.
Testo completo
9
Li, Ting [Verfasser]. "Brain electrophysiological oscillations and vision loss in occipital stroke patients / Ting Li". Magdeburg : Universitätsbibliothek, 2016. http://d-nb.info/1105554767/34.
Testo completo
10
Gowda, Vidya. "Credibility of a Person-Centered Design Decision-making Prototype: Spaces for Older Persons with Vision Loss". Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/81388.
Testo completoAbstract (sommario):
Decline in both visual acuity and visual performance is a fact of life for older people and their increasing share of the population requires that buildings be designed with their visual needs in mind. As their field of vision decreases, people find it harder to identify an objects location, distance, and orientation. Elderly people with vision impairments usually find it harder to perform daily activities such as navigation through indoor spaces. Functional vision can be improved by modifying the design of spaces, for example, with better lighting. However, architects typically do not know how to take the needs of the visually impaired into account in their design process, or simply do not think of doing so. The researcher designed and feasibility-tested a prototype person-centered tool to help architects judge how appropriate a designed space will be for visually impaired people. The study was conducted as a qualitative mixed-methodology research analysis. The researcher used knowledge from literature interpretation to rationalize the development of a person-centered prototype. The researcher immersed design PhD students and vision science experts to inform the prototyping process. Along with an expert group of design and vision science professionals, the researcher beta-tested the prototype during a mock design-process scenario. The researcher also selected a small group of industry experts to participate in open-ended interviews on post-use demonstrations to qualitatively triangulate the findings on the prototypes usability. The study summarizes the feasibility including the challenges of using the prototype for professional purposes and suggests improvement.Ph. D.
11
Geringswald, Franziska Verfasser], e Stefan [Gutachter] [Pollmann. "Visual attention and memory under central vision loss / Franziska Geringswald ; Gutachter: Stefan Pollmann". Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1222670712/34.
Testo completo
12
Geringswald, Franziska [Verfasser], e Stefan [Gutachter] Pollmann. "Visual attention and memory under central vision loss / Franziska Geringswald ; Gutachter: Stefan Pollmann". Magdeburg : Universitätsbibliothek Otto-von-Guericke-Universität, 2020. http://d-nb.info/1222670712/34.
Testo completo
13
Holmeide, Ø., e M. Schmitz. "USE OF GIGE VISION ETHERNET CAMERAS FOR FLIGHT TEST APPLICATIONS WITHOUT DATA LOSS". International Foundation for Telemetering, 2016. http://hdl.handle.net/10150/624225.
Testo completoAbstract (sommario):
As Ethernet based networks have become the dominant choice for Flight Test Instrumentation
(FTI) network applications, it is also clear that Ethernet based camera integration and applications
have yet to become more wide spread for system level design and integration. A significant
customer base utilizes either separate video compression systems or even just stand-a-lone gopro
cameras for recording purposes in an unsynchronized ways. The use of uncompressed high
definition (HD) video from GigE Vision Ethernet cameras for flight test applications is a
significant issue in managing the large volumes of data produced by the cameras and forwarding
them to any 1000BASE-T(x) switch port without packet loss and significant delays. Of course an
easy approach to overcome this issue would be to just increase the network bandwidth from
1000BASE-T(x) to 10GBASE-SR, but most FTI systems just moved to 1000BASE-T(x) in the
past years and therefore changing the overall system hardware is cost prohibited. One concern
has been the use of compression algorithms to reduce the required video bandwidth, with the
negative side effect that the image quality reduces and end-to-end latency increases, which is not
acceptable for some applications. Further, it is important that data from cameras is available to a
number of different multicast consumers within the FTI network, for example workstations,
recorders and telemetry systems. These video data stream also require synchronization so that
they can be analyzed in post processing.
14
McGill, Trevor, e University of Lethbridge Faculty of Arts and Science. "Cell therapy limits loss of vision in an animal model of retinal degenerative disease". Thesis, Lethbridge, AB : University of Lethbridge, Faculty of Arts and Science, 2004, 2004. http://hdl.handle.net/10133/274.
Testo completoAbstract (sommario):
The Royal College of Surgeons (RCS) rat was used as a model of human retinal degenerative disease, and for studying the efficacy of cell transplanation treatments. In order to characterize the spatial vision of the RCS strain, the visual acutiy and contrast sensitivity of adult non-dystrophic RCS rats was measured. The acuity and contrast sensitivity of these rats was normal. The acuity of dystrophic RCS rats was alos characterized to determine how photoreceptor degeneration affects vision. These rats progressively lost visual acuity from one month of age until elevn months of age when they were judged to be blind. The degeneration of vision in these animals was more protacted than would be predicted from previous anatomical and electrophysiological measures. Subretinal transplantation of human-derived Retinal Pigment Epithelial (RPE) cells and human Schwann cells into the dystrophic RCS rat significantly delayed the loss of visual acuity. These studies show that cell transplantation may be a viable method of limiting loss of vision in humans with retinal degenerative blinding diseases.vii, 77 leaves ; 29 cm.
15
Grabusic, Carmen C. "Older adults with vision loss, a consideration of coping strategies, appraisals, and coping resources". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq23320.pdf.
Testo completo
16
Fast, Danene K. "Bus Drivers, Customers, & Canes:Exploring Accessibility to Public Transportation for Travelers with Vision Loss". The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1529780547432842.
Testo completo
17
Bradley, Sapora L. "Tactile Media: Factors Affecting the Adoption of Touchscreen Smartphones Among Consumers with Vision Loss". Thesis, University of North Texas, 2012. https://digital.library.unt.edu/ark:/67531/metadc115052/.
Testo completoAbstract (sommario):
Touchscreen technology is on the rise as the new standard in smartphone design. But, the usability of touchscreen is hindered for consumers that lack the physical ability to navigate such devices. Two focus groups were conducted in order to identify specific uses and gratifications that people with visual impairments had when using mobile phones. Additional questions were presented to the participants to determine if touchscreen technology limited access to communication and entertainment. The responses revealed an upward trend in touchscreen smartphone adoption among the participants. These users chose to adopt touchscreen smartphones that had built-in and downloadable assistive features which contributed to user-friendly designs.
18
Venkataraman, Abinaya Priya. "Vision Beyond the Fovea: Evaluation and Stimuli Properties". Doctoral thesis, KTH, Biomedicinsk fysik och röntgenfysik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-191212.
Testo completoAbstract (sommario):
This research is about evaluating vision in the periphery. Peripheral vision is of fundamental importance in the performance of our everyday activities. The aim of this thesis is to develop methods suitable for the evaluation of peripheral vision and to assess how different visual functions vary across the visual field. The results have application both within the field of visual rehabilitation of people with central visual field loss (CFL)and as well as in myopia research. All methods for assessing peripheral vision were implemented with adaptive psychophysical algorithms based on Bayesian statistics. A routine for time-efficient evaluation of peripheral contrast sensitivity was implemented and verified for measurements out to 30° in the visual field. Peripheral vision was evaluated for different properties of the stimuli: sharpness, motion, orientation, and extent. Optical quality was controlled using adaptive optics and/or corrective spectacles specially adapted for the peripheral viewing angle. We found that many peripheral visual functions improved with optical correction, especially in people with CFL. We also found improvements in peripheral contrast sensitivity for low spatial frequencies when stimuli drifted at 5 to 10 Hz; this applies both for people with normal vision and those with CFL. In the periphery, it is easier to see lines that are oriented parallel with respect to the visual field meridian. We have shown that this directional bias is present for both resolution and detection tasks in the periphery, even when the asymmetric optical errors are minimized. For accurate evaluation of peripheral vision, we therefore recommend using gratings that are oriented oblique to the visual field meridian. The directional bias may have implications in how peripheral image quality affects myopia progression. Another proof that peripheral vision can influence central visual function is the fact that, when the stimulus extent was increased beyond the fovea, the blur in the stimulus was less noticeable.Denna forskning handlar om att utvärdera synen i periferin. Vår perifera syn är ovärderlig i det dagliga livet. Målsättningen med denna avhandling är dels att utveckla metoder speciellt lämpade för perifer synutvärdering och dels att mäta hur olika synfunktioner varierar över synfältet. Resultaten har tillämpning både inom synrehabilitering för personer med centraltsynfältsbortfall och inom närsynthetsforskning. Adaptiv psykofysisk metodologi baserad på Bayesiansk statistik användes vid all utvärdering av det perifera seendet. Vi implementerade en rutin för tidseffektiv mätning av perifer kontrastkänslighet och verifierade den ut till 30° i synfältet. Den perifera synen utvärderades för olika egenskaper hos objektet: skärpa, rörelse, riktning och utbredning. Skärpan kontrollerades med hjälp av adaptiv optik och/eller glasögonkorrektion speciellt anpassad för den perifera synvinkeln. Vi fann att många periferasynfunktioner förbättras av optisk korrektion, särskilt för personer med centralt synfältsbortfall. Vi hittade även förbättringar i periferkontrastkänslighet för låga ortsfrekvenser när objektet modulerades med hastigheter mellan 5 och 10 Hz, vilket gäller både normalseende och personer med centralt synfältsbortfall. I periferin är det lättare att se linjer som är orienterade parallellt med synfältsmeridianen. Vi har visat att denna riktningsbias gäller både för upplösning och detektion i periferin, även när de asymmetriska optiska felen minimeras. För bästa mätnoggrannhet rekommenderar vi därför att använda randmönster som ligger snett relativt synfältsmeridianen. Denna riktningsbias skulle även kunna påverka hur den perifera bildkvalitén inverkar på utvecklingen av närsynthet. Ytterligare ett bevis för att perifer syn kan påverka den centrala synfunktionen är att, när objektets utbredning ökades, uppfattade personen det som mindre suddigt.
QC 20160826
19
Grund, Pihlgren Gustav. "Deep Perceptual Loss for Improved Downstream Prediction". Licentiate thesis, Luleå tekniska universitet, EISLAB, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86440.
Testo completo
20
Stinnette, Delinda. "Locus of control and adjustment to vision loss among people with Age Related Macular Degeneration". ScholarWorks, 2009. https://scholarworks.waldenu.edu/dissertations/722.
Testo completoAbstract (sommario):
People aged 65 and older account for 12.8% of the population and for 30% of all visually impaired individuals. Age-related Macular Degeneration (ARMD) has been identified as a significant public health issue, with a potential 8 million Americans at risk. While the literature supports a connection between LOC and adaptation to ARMD, there is a gap in the current literature supporting this relationship even when other factors are controlled (i.e. age, sex, education, type of ARMD, when diagnosed, the use of medical treatments, the use of visual assistance devices, participant engagement in rehabilitation, and depression). The present survey study used hierarchical regression to examine the relationship between LOC and adjustment to ARMD while controlling for these factors. A sample of 75 adults aged 60 and older diagnosed with ARMD for at least 6 months completed the Multidimensional Health Locus of Control Scale-Form C (MHLC), the Adaptation to Age-Related Vision Loss Scale (AVL) and the Geriatric Depression Scale-Short Form (GDS). LOC accounted for 30% of the variance in adjustment beyond what was explained by the control variables, with higher internal LOC being associated with greater adaptation to loss. The present results add to the existing literature and enhance social change initiatives by guiding the development of interventions to mitigate the difficulties experienced by people with ARMD, reduce their dependency on others, and improve their ability to maintain their quality of life.
21
Rönnåsen, Berit. "Aspekter på lärande vid dövblindhet : möjligheter och begränsningar för personer med Alström syndrom". Licentiate thesis, Örebro universitet, Institutionen för hälsovetenskap och medicin, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-44667.
Testo completo
22
Hogan, Claire Louise, of Western Sydney Hawkesbury University, Faculty of Social Inquiry e School of Social Ecology. "Exploring the social effects of visual loss on human interaction". THESIS_FSI_SEL_Hogan_C.xml, 1995. http://handle.uws.edu.au:8081/1959.7/120.
Testo completoAbstract (sommario):
Theories on the impact of visual loss tend to generalise and can simplify complex issues. Two extreme views are challenged that portray the impact of visual loss as catastrophic or as a minor inconvenience. The argument is put forward that the impact of visual loss can lessen with improved interaction, and this theory is tested by the author questioning and modifying her own interaction. The following themes are explored: limbo status and self-acceptance; the common stresses experienced when asking for help; and discriminatory attitudes. The research is action based, and the emphasis is on how individuals adjust and adapt to loss, rather than the stresses experienced.Master of Science (Hons)
23
Bruce, Carrie M. "Facilitating participation in adults with and without vision loss by supporting exhibit motivations through real-time descriptive mediation". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51832.
Testo completoAbstract (sommario):
Design and evaluation of real-time descriptive mediation (RTDM) for live aquarium exhibits was proposed to support the participation of visitors with and without vision loss. RTDM was developed to address learning, entertainment, restorative, and social motivations. Data was collected during a lab study with adults to get feedback about the RTDM and compare it to traditional docent presentations and audio tours. Findings show that the RTDM made it possible for participants to address their exhibit motivations and led to specific personal and social aspects of participation. A majority of participants with and without vision loss reported that the RTDM was supportive of their motivations and perceived it to be more effective at supporting learning, social, and restoration motivations compared to audio tour and docent mediation. The main contributions of this work are in: 1) developing evidence-based information design criteria for mediation at live animal exhibits; 2) demonstrating that mediation designed to support exhibit motivations can facilitate participation in adults with and without vision loss; and 3) validating participation as a design goal.
24
Lee, Seunghyun. "Impact of universal design ballot interfaces on voting performance and satisfaction of people with and without vision loss". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53477.
Testo completoAbstract (sommario):
Since the Help America Vote Act (HAVA) in 2002 that addressed improvements to voting systems and voter access through the use of electronic technologies, electronic voting systems have improved in U.S. elections. However, voters with disabilities have been disappointed and frustrated, because they have not been able to vote privately and independently (Runyan, 2007). Voting accessibility for individuals with disabilities has generally been accomplished through specialized designs, providing the addition of alternative inputs (e.g., headphones with tactile keypad for audio output, sip-and-puff) and outputs (e.g., audio output) to existing hardware and/or software architecture. However, while the add-on features may technically be accessible, they are often complex and difficult for poll workers to set up and require more time for targeted voters with disabilities to use compared to the direct touch that enable voters without disabilities to select any candidate in a particular contest at any time.
To address the complexities and inequities with the accessible alternatives, a universal design (UD) approach was used to design two experimental ballot interfaces, namely EZ Ballot and QUICK Ballot, that seamlessly integrate accessible features (e.g., audio output) based on the goal of designing one voting system for all. EZ Ballot presents information linearly (i.e., one candidate’s name at a time) and voters can choose Yes or No inputs that does not require search (i.e., finding a particular name). QUICK Ballot presents multiple names that allow users to choose a name using direct-touch or gesture-touch interactions (e.g., the drag and lift gesture). Despite the same goal of providing one type of voting system for all voters, each ballot has a unique selection and navigation process designed to facilitate access and participation in voting.
Thus, my proposed research plan was to examine the effectiveness of the two UD ballots primarily with respect to their different ballot structures in facilitating voting performance and satisfaction for people with a range of visual abilities including those with blindness or vision loss. The findings from this work show that voters with a range of visual abilities were able to use both ballots independently. However, as expected, the voter performance and preferences of each ballot interface differed by voters through the range of visual abilities. While non-sighted voters made fewer errors on the linear ballot (EZ Ballot), partially-sighted and sighted voters completed the random access ballot (QUICK Ballot) in less time. In addition, a higher percentage of non-sighted participants preferred the linear ballot, and a higher percentage of sighted participants preferred the random ballot.
The main contributions of this work are in: 1) utilizing UD principles to design ballot interfaces that can be differentially usable by voters with a range of abilities; 2) demonstrating the feasibility of two UD ballot interfaces by voters with a range of visual abilities; 3) providing an impact for people with a range of visual abilities on other applications. The study suggests that the two ballots, both designed according to UD principles but with different weighting of principles, can be differentially usable by individuals with a range of visual abilities. This approach clearly distinguishes this work from previous efforts, which have focused on developing one UD solution for everyone because UD does not dictate a single solution for everyone (e.g., a one-size-fits-all approach), but rather supports flexibility in use that provide a new perspective into human-computer interaction (Stephanidis, 2001).
25
Wärme, Josefin. "Prevalence of eye and visual symptoms among office workers and their relationship to self-assessed productivity loss". Thesis, Högskolan i Gävle, Arbetshälsovetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-35721.
Testo completoAbstract (sommario):
Aim: The dual aims of this descriptive cross-sectional study were: 1) to assess the prevalence of eye-and visual symptoms among a population of office workers and; 2) to analyse if these symptoms were associated with self-assessed productivity. Method: A questionnaire consisting of the Computer Vision Syndrome Questionnaire, Convergence Insufficiency Symptom Scale and the Work Limitations Questionnaire was provided to each employee. Descriptive statistics on the number of individuals classified as eye-and visual symptom cases was computed. Multiple logistic regressions analyses were performed on the individual eye-and visual symptom scores as independent variables with the self-assessed productivity limitation scores as the dependent variable. Main result: Out of 127 office workers, 76 answered the questionnaire (60% response rate). The estimated prevalence’s of eye- and visual symptoms were 73% (95% CI: 61−83%) for Computer Vision Syndrome and 32% (95% CI: 21−43%) for Convergence Insufficiency-related symptoms. The multiple regression analyses revealed strong positive associations between eye/visual symptoms and productivity limitations for both Computer Vision Syndrome scores (p<0.001, r2=0,22) and Convergence Insufficiency-related symptoms scores (p<0.001, r2=0,39). Conclusions: Symptoms of Computer Vision Syndrome and Convergence Insufficiency were both prevalent, the former more so than the later. These symptoms were both strongly associated with limitations in self-assessed productivity. More research efforts are warranted to replicate and explore these work and health associations.Syfte: Det första syftet i studien var att uppskatta prevalensen av Computer Vision Syndrome och symtom relaterade till konvergensinsufficiens i en population av kontorsarbetare. Det andra syftet var att analysera om det fanns ett samband mellan dessa symtom och självskattad produktivitetsförlust eller inte. Metod: En kvantitativ enkätstudie med tvärsnittsdesign genomfördes med följande enkätinstrument: Computer Vision Syndrome Questionnaire, Convergence Insufficiency Symptom Scale and Work Limitations Questionnaire. Deskriptiv statistik beräknades för prevalenserna av antalet fall som var drabbade av respektive arbetshälsoproblem. Två separata multipla regressionsanalyser genomfördes dessutom. Huvudresultat: 76 kontorsarbetare svarade på enkäten (60 % svarsfrekvens). Den uppskattade prevalensen av Computer Vision Syndrome var 73% (95% CI: 61−83%) och av symtom relaterade till konvergensinsufficiens var 32% (95% CI: 21−43%). De multipla regressionsanalyserna visade statistiskt signifikanta (p < 0,001) samband mellan både Computer Vision Syndrome och symtom relaterade till konvergensinsufficiens, med självskattad produktivitetsförlust. Ju mer synsymtom en person skattade, desto högre var den självskattade produktivitetsförlusten. Slutsats: Nästan tre fjärdedelar av kontorsarbetarna hade Computer Vision Syndrome och en tredjedel uppgav symtom relaterade till konvergensinsufficiens. Detta är ett arbetshälsoproblem för de drabbade kontorsarbetarna som behöver åtgärdas, både för de möjliga arbetshälsovinsterna för arbetstagarna och för de möjliga produktivitetsvinsterna för företagen. Större studier behövs för att bekräfta och vidare analysera sambanden mellan synhälsa och arbetsproduktivitet.
26
Al, Shaghthrah Ali. "A study to develop a new clinical measure to assess visual awareness in tunnel vision". Thesis, University of Manchester, 2014. https://www.research.manchester.ac.uk/portal/en/theses/a-study-to-develop-a-new-clinical-measure-to-assess-visual-awareness-in-tunnel-vision(6ce81a5f-cd0e-4d72-97e4-d4c8632c40b0).html.
Testo completoAbstract (sommario):
Visual conditions such as retinitis pigmentosa and Usher syndrome can gradually cause tunnel vision. Patients with these conditions usually face difficulties with navigation, avoiding obstacles, and performing visual search. Loss of mobility can affect patients' independence and quality of life. One of the rehabilitation strategies for patients with tunnel vision is the use of optical aids to enhance mobility performance. The main method used to evaluate the usefulness of optical aids is the patient’s subjective report after extended wear. In order to evaluate optical aid effectiveness in the clinic, a new test based on the visual search paradigm was designed to assess the patient's visual awareness. This was named the assessment of visual awareness (AVA) test. The main aim of this study was to develop the AVA test, establish its sensitivity, validity and repeatability, and then use it to investigate the efficacy of optical aids in this group of people. The AVA test consists of 32 peripheral targets presented at four different locations: 1st annulus (at 5° from the central fixation), 2nd annulus (10°), 3rd annulus (20°) and 4th annulus (30°)). In this study, the peripheral targets were presented singly against a spatial noise background in a presentation area of 81° H × 62° V. Participants were allowed to use head and eye movements and were asked to search for and locate each target. The detection time (DT) was recorded. A new, sensitive and easy to set up indoor mobility course was also designed and validated prior to its use in validating the AVA test. A total of 50 normally sighted participants with simulated tunnel vision (TV) (5° to 20°, in 5° steps) and 20 patients with TV (retained field 4° to 21°) were tested. The AVA test was found to be responsive to the change in field of view (FoV) and to the target locations in both groups of participants. In the simulated group, a significant relationship was found between FoV and DT at each annulus (r ranging from -0.55 to -0.77, p < 0.0001). A significant relationship was found between target location and DT within each FoV size (20°, 15°, 10° and 5°) (r ranging from 0.53 to 0.84, p < 0.0001). In the TV patients, a statistically significant relationship was found between FoV and DT at each annulus (r range from -0.40 to -0.60, p < 0.05). The target location was shown to have a significant relationship with the DT within each FoV size (r ranging from 0.50 to 0.60, p < 0.05). Finally, the AVA test was found to be significantly related to the simulated TV participants' performance on the indoor mobility course. The AVA test was used to assess the efficacy of three optical aids: the partial aperture prism (10 patients), the Tri-field prism (10 patients) and the reverse telescope (4 patients). The AVA test showed no significant improvement in DT with either of the prisms and the participants did not find these aids helpful. DT with the reverse telescope improved, but none of the participants were willing to use these on extended trial. The AVA test gave clear indications of the efficacy of each aid, a result which could affirm the importance of the AVA test. In conclusion, the AVA test was found to be sensitive, valid and repeatable. DT did not improve in either of the optical aids which were found to be unsuccessful, suggesting that the AVA could be a promising clinical test. However the aids which showed improved DT were not evaluated over the longer term, and therefore did not allow full evaluation of the AVA test.
27
Pondorfer, Susanne Gunda [Verfasser]. "Identification of functional markers for detecting vision loss in early and intermediate age-related macular degeneration / Susanne Gunda Pondorfer". Bonn : Universitäts- und Landesbibliothek Bonn, 2020. http://d-nb.info/1218474882/34.
Testo completo
28
Keay, Lisa Jane Optometry & Vision Science Faculty of Science UNSW. "Public health impact of contact lens related microbial keratitis". Awarded by:University of New South Wales. School of Optometry and Vision Science, 2006. http://handle.unsw.edu.au/1959.4/26307.
Testo completoAbstract (sommario):
This thesis describes the impact of contact lens-related microbial keratitis in terms of incidence and severity. Disease outcome is defined by visual outcome, costs to the healthcare system, costs to the individual and duration of disease. A successful 12-month surveillance study was conducted of the populations of Australia and New Zealand to detect all cases of contact lens-related microbial keratitis. A random telephone survey of 32,000 households in Australia and 7,500 in New Zealand accurately determined the level of use of various contact lenses in the community. The impact of new contact lens types: silicone hydrogels and daily disposables were investigated. Increased risk persisted in overnight wear with silicone hydrogel materials. Microbial keratitis associated with silicone hydrogel materials had slightly shorter disease duration however other factors had a stronger influence on severity. Rigid gas permeable and frequent replacement soft lenses when used for daily wear constitute the lowest risk. Cost analysis was developed in a hospital case series of microbial keratitis. This analysis was applied in the surveillance study including cases managed in the private health care sector. Disease duration and associated costs are novel indices of severity for contact lens-related disease. The most dramatic effects on disease severity were seen with the type of organism involved. Keratitis attributed to environmental organisms (Gram-negative bacteria, Acanthamoeba, fungi and Nocardia species) were 10x more likely to cause loss of visual acuity, had longer duration of symptoms and incurred higher costs. Importantly, delays in receiving treatment increased disease duration and associated costs. Greater awareness of the need for specialist healthcare is indicated amongst health care providers and contact lens wearers. The hypothesis that overnight wear in silicone hydrogel lenses would not increase the risk of infection has been disproven. This information is of value to practitioners who are responsible for informing contact lens wearers about the risk of contact lens-related infections and should be weighed against the benefits of continuous wear. The identification of factors which contribute to the outcomes of disease will be used in education campaigns amongst health care providers and contact lens wearers to minimise the impact of disease.
29
Lewis, Peter. "Improving Peripheral Vision Through Optical Correction and Stimulus Motion". Doctoral thesis, Linnéuniversitetet, Institutionen för medicin och optometri (MEO), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-52286.
Testo completoAbstract (sommario):
The loss of central vision subsequent to macular disease is often extremely debilitating. People with central field loss (CFL) must use other peripheral areas of the retina in order to see; areas with inferior resolution capacity, which are also affected by off-axis optical errors. The overall aim of the work encompassed by this thesis was to identify and evaluate methods of improving vision for people with CFL; with focus on the effects of off-axis optical correction and stimulus motion on resolution acuity and contrast sensitivity. Off-axis optical errors were measured using a commercially-available COAS-HD VR open-view aberrometer. We used adaptive psychophysical methods to evaluate grating resolution acuity and contrast sensitivity in the peripheral visual field; drifting gratings were employed to measure the effect of motion on these two measures of visual performance. The effect of sphero-cylindrical correction and stimulus motion on visual performance in healthy eyes and in subjects with CFL was also studied; in addition, the effect of adaptive optics aberration correction was examined in one subject with CFL. The COAS-HD aberrometer provided rapid and reliable measurements of off-axis refractive errors. Correction of these errors gave improvements in low-contrast resolution acuity in subjects with higher amounts of oblique astigmatism. Optical correction also improved high-contrast resolution acuity in most subjects with CFL, but not for healthy subjects. Adaptive optics correction improved both high and low contrast resolution acuity in the preferred retinal locus of a subject with CFL. The effect of stimulus motion depended on spatial frequency; motion of 7.5 Hz improved contrast sensitivity for stimuli of low spatial frequency in healthy and CFL subjects. Motion of 15 Hz had little effect on contrast sensitivity for low spatial frequency but resulted in reduced contrast sensitivity for higher spatial frequencies in healthy subjects. Finally, high-contrast resolution acuity was relatively insensitive to stimulus motion in the periphery. This thesis has served to broaden the knowledge regarding peripheral optical errors, stimulus motion and their effects on visual function, both in healthy subjects and in people with CFL. Overall it has shown that correction of off-axis refractive errors is important for optimizing peripheral vision in subjects with CFL; the use of an open-view aberrometer simplifies the determination of these errors. In addition, moderate stimulus motion can have a beneficial effect on contrast sensitivity for objects of predominantly low spatial frequency.
30
Hogan, Claire Louise. "Exploring the social effects of visual loss on human interaction /". View thesis, 1995. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030818.135525/index.html.
Testo completo
31
Demker, Rose-Marie, e Evergren Ida Sterki. "En annan syn på livet : Äldres upplevelse av att leva med grav synnedsättning". Thesis, Högskolan i Halmstad, Akademin för hälsa och välfärd, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-37802.
Testo completoAbstract (sommario):
Att som äldre drabbas av grav synnedsättning påverkar livet på olika sätt och för ögonsjuksköterskan blir det viktigt att förstå dessa patienters upplevelser. Syftet var att undersöka äldres upplevelser av att drabba av åldersrelaterade ögonsjukdomar som ger en kraftigt nedsatt syn. Studien är en integrativ litteraturstudie där analysen resulterade i tre områden av särskild betydelse för dessa patienter; att förlora sitt oberoende, livet blev inte som planerat samt att finna nya vägar. Resultatet visar att äldre med synnedsättning var mindre aktiva, mindre självständiga, och mindre nöjda med livet än de med god syn. Det visade sig att äldres syn hade stor betydelse för deras upplevelse av hälsa. Genom ett personcentrerat förhållningssätt kan ögonsjuksköterskan bemöta dessa patienter i deras livsförändring och genom samtal förbereda patienten inför hur livet kan komma att förändras med synnedsättning, samt skapa realistiska förhoppningar inför framtiden. Ögonsjuksköterskan kan förmedla kontakt med stödfunktioner såsom Synverksamheten och därmed hjälpa patienterna att finna nya lösningar i vardagen.Learning how to live with severe visual impairment in old age affects many areas in their everyday life and for an ophthalmic nurse it is important to understand these patients’ experiences. The aim of the study was to find out elderly people’s experiences of suffering of age-related visual impairment. The study is an integrative literature study in which the analysis resulted in three areas of special meaning for these patients: loosing independence, life was not as planned and finding new ways. The result shows that elderly with visual impairment where less active, less independent, and less pleased with life than those with good visual ability. Research showed that elder´s visual ability had great meaning of how they experienced their health. Having a person centered approach the ophthalmic nurse can support these patients in their lifestyle changes and through a dialogue prepare patients for the upcoming changes of life living with visual impairment. The ophthalmic nurse can also support the patients to get realistic expectations of the future. The ophthalmic nurse can mediate contact with supportive functions such as Synverksamheten, and thereby help patients to find solutions coping with their everyday life.
32
Suen, Meagan M. C. "The Impact of Executive Function and Loss of Peripheral Vision on Gait Performance| A Dual-Task Comparison between Younger and Older Adults". Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10690926.
Testo completoAbstract (sommario):
Previous studies have linked poor cognitive-motor dual-task performance to increased fall risk in older adults. However, the degree to which cognition and vision influence gait is disputed. The current study investigated the impact of two executive function tasks (working memory versus executive inhibition) and peripheral vision on gait performance during dual-task in healthy younger and older adults. It was hypothesized that there would be an interaction effect between 1) cognitive tasks and age groups, and 2) vision and age groups on overall gait performance interference. It was also hypothesized that there would be a main effect for 3) cognitive tasks, 4) vision, and 5) age groups. Participants performed two separate cognitive tasks (serial subtraction by 3s and a Stroop task) while walking under a normal-vision and peripheral vision-loss condition. Gait parameters were measured under single and dual task conditions. Results showed that the Stroop task produced greater gait interference for all age groups and vision conditions. Also, older adults had greater gait interference compared to younger adults, regardless of the type of concurrent cognitive tasks. Findings from this study can be implemented into fall prevention programs in community-dwelling and clinical populations.
33
Wu, Allen David. "Vision-based navigation and mapping for flight in GPS-denied environments". Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/37281.
Testo completoAbstract (sommario):
Traditionally, the task of determining aircraft position and attitude for automatic control has been handled by the combination of an inertial measurement unit (IMU) with a Global Positioning System (GPS) receiver. In this configuration, accelerations and angular rates from the IMU can be integrated forward in time, and position updates from the GPS can be used to bound the errors that result from this integration. However, reliance on the reception of GPS signals places artificial constraints on aircraft such as small unmanned aerial vehicles (UAVs) that are otherwise physically capable of operation in indoor, cluttered, or adversarial environments.
Therefore, this work investigates methods for incorporating a monocular vision sensor into a standard avionics suite. Vision sensors possess the potential to extract information about the surrounding environment and determine the locations of features or points of interest. Having mapped out landmarks in an unknown environment, subsequent observations by the vision sensor can in turn be used to resolve aircraft position and orientation while continuing to map out new features.
An extended Kalman filter framework for performing the tasks of vision-based mapping and navigation is presented. Feature points are detected in each image using a Harris corner detector, and these feature measurements are corresponded from frame to frame using a statistical Z-test. When GPS is available, sequential observations of a single landmark point allow the point's location in inertial space to be estimated. When GPS is not available, landmarks that have been sufficiently triangulated can be used for estimating vehicle position and attitude.
Simulation and real-time flight test results for vision-based mapping and navigation are presented to demonstrate feasibility in real-time applications. These methods are then integrated into a practical framework for flight in GPS-denied environments and verified through the autonomous flight of a UAV during a loss-of-GPS scenario. The methodology is also extended to the application of vehicles equipped with stereo vision systems. This framework enables aircraft capable of hovering in place to maintain a bounded pose estimate indefinitely without drift during a GPS outage.
34
Alvarsson, Christel, e Karolina Carlsson. "Finns dropparna så finns de och finns de inte får det gå bra ändå : Sjuksköterskors erfarenheter av att ge omvårdnad till inneliggande patienter med ögonsjukdomar". Thesis, Högskolan i Halmstad, Sektionen för hälsa och samhälle (HOS), 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-25493.
Testo completoAbstract (sommario):
Patienter med ögonsjukdomar är en stor patientgrupp som förväntas öka, då många av sjukdomarna är åldersrelaterade och befolkningen i världen blir allt äldre. Ett stort antal av patienterna kommer att förekomma på olika vårdavdelningar där de vårdas av annan orsak. Omvårdnad är sjuksköterskans huvudansvar och hennes profession medför att riktlinjer och lagar ska följas i samband med yrkesutövning. Syftet med pilotstudien var att undersöka sjuksköterskors erfarenheter av att ge omvårdnad till inneliggande patienter med olika ögonsjukdomar i anamnesen. Pilotstudien genomfördes med en kvalitativ metod och datainsamlingen skedde genom intervjuer. Data analyserades med kvalitativ innehållsanalys. Resultatet sammanställdes i tre kategorier: Att erfara bristfälligt ansvarstagande, Att erfara behov av prioriteringar och Att erfara okunskap om ögonsjukvård. Sjuksköterskorna erfor bristfälligt ansvarstagande och de ansåg omvårdnadsarbetet med patienter med olika ögonsjukdomar i anamnesen som svårt. De ansåg sig sakna tillräckligt med kunskap och arbetsbelastningen ledde till att de var tvungna att prioritera på ett sätt som inte gynnade patientgruppen. Sjuksköterskorna uttryckte ett behov av mer utbildning inom detta område. Mer kunskap skulle kunna bidra till att de upplevde en ökad trygghet i sin yrkesroll och leda till en högre patientsäkerhet. Pilotstudien visar att det finns förbättringspotential för att höja patientsäkerheten och som bör följas upp i en fullskalig studie.Patients with ocular diseases are a large group which is expected to increase since many of the ocular diseases are age-related and world population is aging. These patients are found in various wards where they are inpatients because of other causes than ocular diseases. Nursing care is the nurse´s major responsibility and they are obliged to follow guidelines and laws regularizing their profession. The purpose of this pilot study was to investigate nurses´ experience of providing care for inpatients with any ocular disease, in their anamnesis. The pilot study was conducted using a qualitative content analysis using interviews. The results were compiled into three categories; Experiencing inadequate accountability, Experiencing the need for priorities, and Experiencing the ignorance of ophthalmology. The nurses in the pilot study experienced nursing care to patients with various eye diseases in history difficult. They thought they lacked sufficient knowledge and because of the workload which made them prioritize in a way which did not benefit the patients. The nurses expressed a need of more education in ophthalmic care. More knowledge would support them in experiencing an increased security in their profession and lead to improved patient safety. The pilot study shows that there is potential for improvement to enhance patient safety and should be followed up in a full scale study.
35
Calabrèse, Aurélie. "Désorganisation fonctionnelle des systèmes oculomoteur et visuo-attentionnnel chez les patients basse vision : - Approche psychophysique-". Thesis, Aix-Marseille 2, 2011. http://www.theses.fr/2011AIX20656/document.
Testo completoAbstract (sommario):
La présence d'un scotome maculaire oblige les patients à utiliser la vision excentrée ce qui provoque une difficulté à coordonner les systèmes oculomoteur et visuo-attentionnel. La lecture devient alors une des plaintes majeures chez ces patients, et les processus impliqués dans la baisse des performances de lecture restent mal connus. Dans la plupart des cas, le patient développe une ou plusieurs zones de la rétine excentrée dites préférentielles, et dénommées couramment PRLs. Nous nous proposons ici d'utiliser une approche psychophysique afin d'étudier les processus de la lecture en vision excentrée. Nous avons tout d'abord élaboré un test de lecture francophone informatisé suivant les principes des MNRead Acuity Charts afin de pouvoir évaluer la vitesse maximale de lecture chez des patients porteurs de scotomes centraux binoculaires dont l'atteinte avait été mesurée à l'aide d'un micropérimètre MP-1. Deux analyses utilisant des modèles statistiques à effets mixtes nous ont permis de mettre en évidence des prédicteurs efficaces de la vitesse maximale de lecture: 1) l'espace interligne; 2) le type de DMLA ; 3) la surface du scot; 4) la distance entre la PRL de fixation et la fovéa; 5) le statut du cristallin. Puis, nous nous sommes intéressés aux stratégies de lecture déployées par les patients. L'analyse de la distribution verticale des fixations enregistrées pendant la lecture nous a permis de mettre en évidence que dans 97% des cas, les patients utilisent une zone préférentielle de la rétine unique dans le plan vertical.Ces résultats présentent des intérêts théoriques et pratiques dans la création de nouveaux supports visuels et techniques de réadaptationPatients with central field loss (CFL) have to use eccentric vision and complain particularly about reading. The purpose of this thesis is to investigate reading processes in those patients using psychophysical tools. First, we investigated predictors of reading performances. We developed a French computerized version of the MNRead Acuity Charts to assess Maximum Reading Speed in patients with binocular scotomas, measured with the microperimeter MP-1. Two distinct analyses using mixed effects models allowed us to estimate the influence of predictors of Maximum Reading Speed: 1) interline spacing; 2) AMD type; 3) scotoma size; 4) distance between fixation PRL and fovea; 5) lens status. Then, we investigated oculomotor patterns of patients during sentence reading. Analysing the vertical distribution of fixations lead us to the conclusion that in most cases (97%), patients use a single eccentric preferred retinal locus (PRL) in the vertical meridian during reading. One potential goal of these studies is to find some ways to enhance text display and improve visual readaptation
36
Hoff, Rein. "The aeroplane spin motion and an investigation into factors affecting the aeroplane spin". Thesis, Brunel University, 2014. http://bura.brunel.ac.uk/handle/2438/10537.
Testo completoAbstract (sommario):
A review of aeroplane spin literature is presented, including early spin research history and lessons learned from spinning trials. Despite many years of experience in spinning evaluation, it is difficult to predict spin characteristics and problems have been encountered and several prototype aeroplanes have been lost. No currently published method will reliably predict an aeroplane’s spin recovery characteristics. Quantitative data is required to study the spin motion of the aeroplane in adequate detail. An alternative method, Vision Based State Estimation, has been used to capture the spin motion. This alternative method has produced unique illustrations of the spinning research aeroplane and data has been obtained that could possibly be very challenging to obtain using traditional methods. To investigate the aerodynamic flow of a spinning aeroplane, flights have been flown using wool tufts on wing, aft fuselage and empennage for flow visualization. To complement the tuft observations, the differential pressure between the upper and lower horizontal tail and wing surfaces have been measured at selected points. Tufts indicate that a large-scale Upper Surface Vortex forms on the outside wing. This USV has also been visualized using a smoke source. The flow structures on top of both wings, and on top of the horizontal tail surfaces, have also been studied on another aeroplane model. The development of these rotational flow effects has been related to the spin motion. It is hypothesized that the flow structure of the turbulent boundary layer on the outside upper wing surface is due to additional accelerations induced by the rotational motion of the aeroplane. The dynamic effects have been discussed and their importance for the development of the spin considered. In addition, it is suggested that another dynamic effect might exist due to the additional acceleration of the turbulent boundary layer due to the rotational motion of the aeroplane. It is recommended that future spin recovery prediction methods account for dynamic effects, in addition to aerodynamic control effectiveness and aeroplane inertia, since the spin entry phase is important for the subsequent development of the spin. Finally, suggestions for future research are given.
37
Koch, Anne Barbara [Verfasser], e Hilary [Akademischer Betreuer] Duffield. "Of Loss and Longing - Nostalgia, Utopian Vision, and the Pastoral in J.R.R. Tolkien's 'The Lord of the Rings' and 'The Hobbit' / Anne Barbara Koch ; Betreuer: Hilary Duffield". Trier : Universität Trier, 2018. http://d-nb.info/1197704183/34.
Testo completo
38
Forssell, Melker, e Gustav Janér. "Product Matching Using Image Similarity". Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-413481.
Testo completoAbstract (sommario):
PriceRunner is an online shopping comparison company. To maintain up-todate prices, PriceRunner has to process large amounts of data every day. The processing of the data includes matching unknown products, referred to as offers, to known products. Offer data includes information about the product such as: title, description, price and often one image of the product. PriceRunner has previously implemented a textual-based machine learning (ML) model, but is also looking for new approaches to complement the current product matching system. The objective of this master’s thesis is to investigate the potential of using an image-based ML model for product matching. Our method uses a similarity learning approach where the network learns to recognise the similarity between images. To achieve this, a siamese neural network was trained with the triplet loss function. The network is trained to map similar images closer together and dissimilar images further apart in a vector space. This approach is often used for face recognition, where there is an extensive amount of classes and a limited amount of images per class, and new classes are frequently added. This is also the case for the image data used in this thesis project. A general model was trained on images from the Clothing and Accessories hierarchy, one of the 16 toplevel hierarchies at PriceRunner, consisting of 17 product categories. The results varied between each product category. Some categories proved to be less suitable for image-based classification while others excelled. The model handles new classes relatively well without any, or with briefer, retraining. It was concluded that there is potential in using images to complement the current product matching system at PriceRunner.
39
Senra, Hugo Renato Carreira Gomes. "From injured body to changes in self-identity: A research on adults with acquired physical impairments". Doctoral thesis, ISPA - Instituto Universitário, 2011. http://hdl.handle.net/10400.12/1348.
Testo completoAbstract (sommario):
Dissertação apresentado ao ISPA-Instituto Universitário para obtenção do grau de Doutor em Psicologia Aplicada: Especialidade Psicologia da ClinicaBackground: The experience of becoming physically impaired, especially in lower limb adult amputees and in working-aged patients with vision loss, has deserved little attention by research in general. The weight of some variables associated with these experiences on depressive levels has been stressed by some studies. However, little is known about it. Aims: The current dissertation aimed at filing in the knowledge gap regarding these topics. We intended to explore the experience of acquired physical impairment, focusing on changes in self-identity, in two groups: working-aged adults with vision loss; and adults who suffered a lower limb amputation. In addition, we aimed at exploring a possible connection between the most relevant emerged variables of these experiences and the depressive levels: the self-awareness of impairment; and the selfidentifications with the impairment. Method: Two independent studies were performed, both was cross-sectional and using mixed-methods: study 1 was on the experiences of vision loss of 38 patients at rehabilitation setting (mean age of 42.7; SD=14.5); and study 2 was on the experiences of lower limb amputation in 42 patients (mean age of 61; SD=13.5) followed-up at a general hospital‟s rehabilitation medicine unit. Qualitative data on the experiences of impairment was collected by two semi-structured interviews for each patient. The interviews were performed by an independent and trained psychologist, under the supervision of a senior psychologist and psychotherapist. 80 interviews were conducted in study 1 and 84 interviews in study 2. Depressive levels were assessed using CES-D. The content analysis was performed using the Categorical and Coding analysis proposed by Bardin. Results: Qualitative data from the study 1, on the experiences of vision loss, retrieved seven themes, most of them focused on changes in self-identity. These results supported a new model for the adjustment process to vision loss, based on patients‟ self-awareness of impairment and self-identifications with the impairment. 39.5% (n=15) of patients met CES-D criteria for depression. Higher depressive levels (P<.05) were found in patients who: lost vision for longer; begun their rehabilitation later; were more aware of their impairment; and those who reported an inadequate social support (P<.01). A positive correlation was found between CES-D scores and vision loss evolution (.333; P=.036), and between CES-D scores and rehabilitation time (.335; P=.035). In study 2, eight themes emerged from the interviews. Qualitative results supported a theoretical model for the changes in self-identity related to lower limb loss beyond the body image. 31% (n=13) met CES-D criteria for Depression. Higher depressive levels (p<.05) were found in those who showed: greater self-awareness of impairment; lower identification with the impairment; and worse appraisals towards the prosthesis, social support and well-being. Conclusions: In both studies the changes in self-identity, especially in terms of selfawareness of impairment and self-identifications with the impairment, arose as core milestones of the adjustment process to the impairment. The relationship found between the variables related to the experience of impairment and depressive levels suggests two conclusions: the changes in self-identity caused by the impairment might be one of the important causes for the rising of depressive levels; the increase in depressive levels in these populations might be, at first, the reflex of the adjustment process to the many personal losses and therefore, do not necessarily reveal a bad adaptation to the impairment nor a mental health problem. ---------- RESUMO ----------Enquadramento: A experiência de amputação de membro inferior em adultos, e a experiência de perda irreversível de visão em adultos não idosos, são dois temas que têm tido pouca atenção por parte da investigação científica. O peso desta experiência ao nível da identidade dos sujeitos e a relação dessas variáveis com os níveis de depressividade são temas considerados relevantes, embora ainda pouco estudados. Objectivos: A presente dissertação veio no propósito de produzir alguma evidência acerca dos tópicos referidos. Com estes estudos pretendemos explorar as experiências incapacidade física adquirida e as suas implicações para a identidade dos sujeitos em dois grupos de sujeitos: adultos que tenham sofrido amputação de membro inferior; e adultos não idosos com perda irreversível e severa de visão. Outro dos objectivos destes estudos foi a investigação preliminar de potenciais relações entre variáveis como a autoconsciência de incapacidade e as auto-identificações com a incapacidade e os níveis de depressividade. Método: Para atingir os objectivos do nosso estudo, delineamos duas investigações independentes. Estudo 1: 38 sujeitos com perda irreversível de visão (média de idades de 42.7 anos; desvio padrão de 14.5), todos eles em fase de reabilitação. Estudo 2: 42 sujeitos amputados (média de idades de 61; desvio padrão de 15.6), todos eles em seguimento na consulta de medicina física e de reabilitação num hospital geral. Em ambos os estudos as experiências de incapacidade foram recolhidas através de uma metodologia qualitativa, com recurso a entrevistas semi-estruturadas realizadas individualmente a cada sujeito. Cada entrevista foi realizada por um investigador independente, formado em Psicologia e com experiencia clínica com este tipo de populações. As entrevistas foram supervisionadas por um Psicólogo e Psicoterapeuta Sénior. Os níveis de depressividade foram avaliados usando o CES-D. A análise do conteúdo das entrevistas foi realizada com base no método de codificação categorial não indutivo de Bardin. Resultados: Os resultados qualitativos do estudo 1 (perda de visão) revelaram sete temas, a maior parte dos quais acerca das alterações ao nível da própria identidade. Esses resultados suportaram um modelo compreensivo para o processo de ajustamento à perda de visão, com base na auto-consciência de incapacidade e nas auto-identificações à incapacidade dos sujeitos estudados. As pontuações no CES-D de 39.5% (n=15) dos sujeitos cumpriram os critérios para depressão clínica. Maiores níveis de depressão (P<.05) foram encontrados nos sujeitos que: tinham perdido a visão há mais tempo; começaram a reabilitação mais tardiamente; estavam mais conscientes a sua incapacidade; e percepcionaram um pior suporte social (P<.01). Foi encontrada uma correlação positiva entre as pontuações dos sujeitos no CES-D e duas variáveis: o tempo decorrido entre o primeiro diagnóstico da doença responsável pela perda de visão e o momento em que o sujeito ficou clinicamente com baixa visão ou cego (.333; P=.036); o tempo de reabilitação (.355; P=.035). No estudo 2 emergiram oito temas sobre a experiência de amputação. Esses resultados suportaram também um modelo teórico compreensivo para as alterações na identidade dos sujeitos, decorrentes da situação de amputação. 31% (n=13) dos sujeitos apresentaram pontuações no CES-D que cumpriram os critérios para depressão clínica. Maiores níveis de depressão (P<.05) foram encontrados nos sujeitos que apresentaram: maior auto-consciência de incapacidade; menor identificação à incapacidade; pior relação com a prótese; pior percepção do suporte social; e pior percepção do bem-estar. xii Conclusões: Nos dois estudos a auto-consciência de incapacidade e as autoidentificações com a incapacidade surgiram como duas variáveis chave do processo de ajustamento à incapacidade, demonstrando o potencial efeito transformador destas situações de incapacidade para identidade dos sujeitos. A associação encontrada entre as variáveis relativas à experiência de incapacidade e os níveis de depressividade parece sugerir duas conclusões: as alterações na identidade decorrentes da situação de incapacidade física adquirida poderão ser uma das importantes causas do aumento dos níveis de depressividade; o aumento dos níveis de depressividade poderão ser, num primeiro momento, reflexo do processo de ajustamento às perdas sofridas e não traduzir, necessariamente, uma má adaptação à situação de incapacidade, nem um problema de saúde mental.
Programa Operacional de Potencial Humano, QREN Portugal, 2007-2013
40
Gargurevich, Juan. "La visión de los entrevistados". Conexión, 2015. http://repositorio.pucp.edu.pe/index/handle/123456789/114693.
Testo completoAbstract (sommario):
Todos los periodistas entrevistan alguna vez a lo largo de su carrera. Y no tienen que ser necesariamente entrevistas que pasan a la historia porque el trajín del oficio exige eso, preguntar, averiguar y luego escribir y describir. Por eso los estantes de las bibliotecas dedicadas al periodismo están repletos de textos queensalzan la entrevista como el género periodístico por excelencia. Pero no encontramos casi nada sobre elpunto de vista del otro actor de la entrevista, esto es, el entrevistado, y que, en especial en la prensa, suele quejarse de haber sido mal interpretado o recortado; y, sin embargo, rara vez se niega a aceptar otra entrevista. De todo esto trata la reflexión que sigue.
41
Maslowski, Petr. "Modifikace obrazu pomocí neuronových sítí". Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2021. http://www.nusl.cz/ntk/nusl-449180.
Testo completoAbstract (sommario):
This thesis deals with image colorization and image super-resolution using neural networks. It briefly explains neural networks principles and summarizes current approaches in this domain. It also describes the design, implementation and training of various neural network architectures. The best implemented architecture can colorize images, in particular, works well with outdoor areas. The architecture for image super-resolution with residual blocks that was trained with a perceptual loss function performs a double increase in image resolution (4x more pixels in total). Part of this thesis is also an implementation of a web application that uses trained models for image modification.
42
Quiroga, Persivale Guillermo. "Hacia una visión integral de los MBA". Universidad Peruana de Ciencias Aplicadas (UPC), 2017. http://hdl.handle.net/10757/624310.
Testo completoAbstract (sommario):
Explica que los MBA a nivel mundial solo mantendrán su relevancia social y su preeminente posición en la formación de los futuros líderes empresariales si incorporan en su misión y se esfuerzan en lograr una educación integral de sus alumnos en tres campos. Los conocimientos, la habilidad para la acción y la integridad en el comportamiento ético. Así como una desarrollada consciencia respecto a la responsabilidad social corporativa.
43
Clark, James Joseph. "Multi-resolution stereo vision with application to the automated measurement of logs". Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25582.
Testo completoAbstract (sommario):
A serial multi-resolution stereo matching algorithm is presented that is based on the Marr-Poggio matcher (Marr and Poggio, 1979). It is shown that the Marr-Poggio feature disambiguation and in-range/out-of-range mechanisms are unreliable for non-constant disparity functions. It is proposed that a disparity function estimate reconstructed from the disparity samples at the lower resolution levels be used to disambiguate possible matches at the high resolutions. Also presented is a disparity scanning algorithm with a similar control structure, which is based on an algorithm recently proposed by Grimson (1985).
It is seen that the proposed algorithms will function reliably only if the disparity measurements are accurate and if the reconstruction process is accurate. The various sources of errors in the matching are analyzed in detail. Witkin's (Witkin, 1983) scale space is used as an analytic tool for describing a hitherto unreported form of disparity error, that caused by spatial filtering of the images with non-constant disparity functions.
The reconstruction process is analyzed in detail. Current methods for performing the reconstruction are reviewed. A new method for reconstructing functions from arbitrarily distributed samples based on applying coordinate transformations to the sampled function is presented. The error due to the reconstruction process is analyzed, and a general formula for the error as a function of the function spectra, sample distribution and reconstruction filter impulse response is derived.
Experimental studies are presented which show how the matching algorithms perform with surfaces of varying bandwidths, and with additive image noise.
It is proposed that matching of scale space feature maps can eliminate many of the problems that the Marr-Poggio type of matchers have. A method for matching scale space maps which operates in the domain of linear disparity functions is presented. This algorithm is used to experimentally verify the effect of spatial filtering on the disparity measurements for non-constant disparity functions.
It is shown that measurements can be made on the binocular scale space maps that give an independent estimate of the disparity gradient this leads to the concept of binocular diffrequency. It is shown that the diffrequency measurements are not affected by the spatial filtering effect for linear disparities. Experiments are described which show that the disparity gradient can be obtained by diffrequency measurement. An industrial application for stereo vision is described. The application is automated measurement of logs, or log scaling. A moment based method for estimating the log volume from the segmented two dimensional disparity map of the log scene is described. Experiments
are described which indicate that log volumes can be estimated to within 10%.Applied Science, Faculty of
Electrical and Computer Engineering, Department of
Graduate
44
Maurice, Camille. "Reconnaissance d'actions humaines dans des vidéos, en particulier lors d'interaction avec des objets". Thesis, Toulouse 3, 2020. http://www.theses.fr/2020TOU30188.
Testo completoAbstract (sommario):
Dans cette thèse nous étudions la reconnaissance d'actions humaines. Typiquement, différentes actions se déroulent dans un même lieu et font intervenir divers objets. Ce problème est difficile en raison de la variété et la ressemblance de certaines actions, de l'encombrement du fond de la scène. De nombreuses approches de vision par ordinateur étudient cette problématique et leur performance est souvent dépendante du paramétrage de certains hyper-paramètres. Par exemple pour les approches d'apprentissage profond nous retrouvons l'initialisation du learning-rate, la taille des mini-lots... Partant de ce constat, nous commençons par une étude comparative des outils d'optimisation des hyper-paramètres de la littérature appliquée à une problématique de vision par ordinateur. Puis nous proposons une première approche bayésienne originale pour la reconnaissance d'actions en ligne qui repose sur des primitives de haut-niveau en 3D : l'observation du squelette humain et les objets environnants. Les nombreux paramètres à régler sont optimisés grâce à l'outil d'optimisation qui émerge de notre étude comparative. Les performances de cette première approche sont comparées à un réseau d'apprentissage profond de l'état de l'art, il en ressort une certaine complémentarité que nous proposons d'exploiter à travers un mécanisme de fusion. Enfin, suite aux récentes avancées dans les réseaux de convolutions à graphes, nous proposons une approche compacte originale et modulaire qui repose sur la construction de graphes spatio-temporels du squelette et des objets. Ces différentes approches sont évaluées et comparées, en performance brute et vis-à-vis des actions sous-représentées sur différents jeux de données publiques qui proposent des séquences d'actions de la vie quotidienne. Nos approches montrent des gains de performance intéressants eu égard à la littérature, notamment vis-à-vis des classes sous représentées dans le jeu de donnéesIn this thesis we study the recognition of actions of daily life. Typically, different actions take place in the same place and involve various objects. This problem is difficult because of the variety and resemblance of some actions and the clutter in the background. Many computer vision approaches study this problem and their performance is often dependent on the setting of certain hyper-parameters. For example, for deep learning approaches there are: the initialization of the learning-rate, the size of the mini-batch... Based on this observation, we begin with a comparative study of hyper-parameter optimization tools from the literature applied to a computer vision problem. Then we propose a first Bayesian approach for online action recognition based on high-level 3D primitives: the observation of the human skeleton and surrounding objects. The parameters to be set are optimized thanks to the optimization tool that emerges from our comparative study. The performances of this first approach are compared to a deep state of the art learning network, and a certain complementarity emerges that we propose to exploit through a fusion mechanism. Finally, following recent advances in graph convolutional networks, we propose a light and modular approach based on the construction of spatio-temporal graphs of the skeleton and objects. The validity of the different approaches is evaluated, in raw performance and with respect to under-represented actions on different public data sets that propose sequences of actions of everyday life. Our approaches show interesting results compared to the literature especially regarding imbalanced data and under-represented classes in datasets
45
Folio, David. "Stratégies de commande référencées multi-capteurs et gestion de la perte du signal visuel pour la navigation d’un robot mobile". Toulouse 3, 2007. http://www.theses.fr/2007TOU30253.
Testo completoAbstract (sommario):
L'amélioration des capteurs a permis l'émergence de la commande référencée capteurs qui permet la réalisation de diverses tâches de navigation de façon précises. L'intention de cette thèse est de contribuer à définir des stratégies de commande référencées multicapteurs pour un robot mobile réalisant une tâche référencée vision dans un environnement encombré d'obstacles susceptibles d'occulter le motif visuel. Nous avons ainsi proposé des lois de commandes permettant d'éviter à la fois les occultations et les collisions. Toutefois,les résultats obtenus ont montré que chercher à éviter simultanément ces deux phénomènes sur-contraignait le mouvement du robot,limitant la gamme des missions réalisables. Nous avons alors proposé une approche alternative consistant à tolérer la perte totale du signal visuel. Nous avons ainsi proposé dans un cadre général plusieurs méthodes (analytiques et numériques) de reconstruction du signal visuel lorsqu'il devient indisponibleThe recent sensors improvement gave rise to the sensor-based control which allows to perform various and accurate navigation tasks. This thesis aims at developing sensorbased control laws allowing a mobile robot to perform vision-based tasks amidst possibly occluding obstacles. Indeed,it is necessary to preserve not only the robot safety (ie. Noncollision) but also the visual features visibility. Thus,we have first proposed techniques able to fulfill simultaneously the two previously mentioned objectives. However,avoiding both collisions and occlusions often over-strained the robotic navigation task,reducing the range of realizable missions. This is the reason why we have developed a second approach which lets the visual features loss occurs if it is necessary for the task realization. Using the link between vision and motion,we have proposed different methods (analytical and numerical) to compute the visual signal as soon it becomes totally unavailable
46
Bobadilla, Rodríguez Francisco. "Visión Sistémica de los Derechos de la Persona". Derecho & Sociedad, 2017. http://repositorio.pucp.edu.pe/index/handle/123456789/117831.
Testo completo
47
Egüez, Toledo Juan Antonio, Seijas José Juan Haro e Mulanovich Gonzalo Zegarra. "El Poder Judicial: la visión de los magistrados". THĒMIS-Revista de Derecho, 2015. http://repositorio.pucp.edu.pe/index/handle/123456789/109192.
Testo completoAbstract (sommario):
En los últimos años se ha realizado una serie de investigaciones acerca del papel de la administra ción de justicia en el Perú. La mayor parte de ellas ha tomado en cuenta la opinión de los abogados y de las partes involucradas en los procedimientos judiciales, pero muy pocas, o casi ninguna, han analizado las perspectivas de los jueces peruanos. La presente encuesta es parte de un esfuerzo de THEMIS - Revista de Derecho para destacar la visión de los jueces sobre nuestra administración de justicia y para contribuir a un mejor análisis de los problemas por los que se atraviesa.La encuesta fue originalmente dirigida a los jueces civiles y penales de primera instancia de la ciudad de Lima, aunque finalmente se concentró en los jueces especializados en lo penal debido a que muy pocos magistrados especializados en lo civil colaboraron con la realización de la presente investigación. Cabe señalar que en el momento en que se realizó la etapa inicial de la investigación, la mayoría de los magistrados habían sido nombrados provisionalmente por el actual gobier no, lo que -de alguna forma- podría haber motivado su actitud. Posteriormente, en el mes de noviembre de 1994, el Jurado de Honor de la Magis tratura nombró a los actuales jueces titulares.Los resultados de la presente investigación nos servirán para aproximamos a la opinión de los magistrados respecto a temas controversiales co mo su eficiencia y ética profesional (abordándose principalmente aspectos tales como su formación académica, sus remuneraciones, así como su carga procesal y la celeridad con que emiten sus resoluciones), el sistema de elección de los magistrados, las presiones que reciben en el ejercicio de su profesión y la opinión que tienen acerca de la actua ción de los abogados litigantesción de los abogados litigantes.
48
Bouet, Romain Knoblauch Kenneth Dojat Michel. "Activations cérébrales liées à l'intégration des indices locaux lors de la perception de la transparence investigation basée sur l'imagerie fonctionnelle cérébrale /". Lyon : Université Lumière Lyon 2, 2007. http://demeter.univ-lyon2.fr/sdx/theses/lyon2/2007/bouet_r.
Testo completo
49
Dessirier, Bruno. "Apport de la vision artificielle à la mécanique des milieux continus. : application à l'étude des lois de comportement en traction et compression". Lille 1, 1989. http://www.theses.fr/1989LIL10161.
Testo completoAbstract (sommario):
Dans le domaine élastique, les essais de traction et de compression des matériaux nécessitent la mesure simultanée de l'effort appliquée à l'éprouvette et de son allongement. Dans cette thèse, on montre d'abord comment un système de vision artificielle peut remplacer avantageusement toute une gamme d'extensomètres traditionnels. Mais c'est dans le domaine plastique que l'apport de la vision artificielle est le plus déterminant car elle permet de modéliser le profil de l'éprouvette quand celle-ci est sollicitée au-delà de sa limite élastique. Dans le cas des essais de traction, on peut ainsi connaitre la section réelle de l'éprouvette au niveau de la striction jusqu'à présent très difficile, sinon impossible, de connaitre l'évolution du profil de l'éprouvette. Le système de vision permet d'accéder simplement et sans contact à des mesures de ce profil aisément modélisable. Un prototype a été réalisé en intégrant un système de vision industriel dans une machine d'essai universelle. Ses performances sont validées en comparant les valeurs réelles des paramètres mécaniques de matériaux soumis aux essais à celles déterminées par le système de mesure sans contact.
50
Eguiguren, Praeli Francisco José. "Los Tribunales Constitucionales en la región andina:una visión comparativa". Pontificia Universidad Católica del Perú, 2013. http://repositorio.pucp.edu.pe/index/handle/123456789/115513.
Testo completo