893 resultados para Hearning and visual problem
Resumo:
This thesis presents two graphical user interfaces for the project DigiQ - Fusion of Digital and Visual Print Quality, a project for computationally modeling the subjective human experience of print quality by measuring the image with certain metrics. After presenting the user interfaces, methods for reducing the computation time of several of the metrics and the image registration process required to compute the metrics, and details of their performance are given. The weighted sample method for the image registration process was able to signifigantly decrease the calculation times while resulting in some error. The random sampling method for the metrics greatly reduced calculation time while maintaining excellent accuracy, but worked with only two of the metrics.
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Diabetes is a rapidly increasing worldwide problem which is characterised by defective metabolism of glucose that causes long-term dysfunction and failure of various organs. The most common complication of diabetes is diabetic retinopathy (DR), which is one of the primary causes of blindness and visual impairment in adults. The rapid increase of diabetes pushes the limits of the current DR screening capabilities for which the digital imaging of the eye fundus (retinal imaging), and automatic or semi-automatic image analysis algorithms provide a potential solution. In this work, the use of colour in the detection of diabetic retinopathy is statistically studied using a supervised algorithm based on one-class classification and Gaussian mixture model estimation. The presented algorithm distinguishes a certain diabetic lesion type from all other possible objects in eye fundus images by only estimating the probability density function of that certain lesion type. For the training and ground truth estimation, the algorithm combines manual annotations of several experts for which the best practices were experimentally selected. By assessing the algorithm’s performance while conducting experiments with the colour space selection, both illuminance and colour correction, and background class information, the use of colour in the detection of diabetic retinopathy was quantitatively evaluated. Another contribution of this work is the benchmarking framework for eye fundus image analysis algorithms needed for the development of the automatic DR detection algorithms. The benchmarking framework provides guidelines on how to construct a benchmarking database that comprises true patient images, ground truth, and an evaluation protocol. The evaluation is based on the standard receiver operating characteristics analysis and it follows the medical practice in the decision making providing protocols for image- and pixel-based evaluations. During the work, two public medical image databases with ground truth were published: DIARETDB0 and DIARETDB1. The framework, DR databases and the final algorithm, are made public in the web to set the baseline results for automatic detection of diabetic retinopathy. Although deviating from the general context of the thesis, a simple and effective optic disc localisation method is presented. The optic disc localisation is discussed, since normal eye fundus structures are fundamental in the characterisation of DR.
Resumo:
The large and growing number of digital images is making manual image search laborious. Only a fraction of the images contain metadata that can be used to search for a particular type of image. Thus, the main research question of this thesis is whether it is possible to learn visual object categories directly from images. Computers process images as long lists of pixels that do not have a clear connection to high-level semantics which could be used in the image search. There are various methods introduced in the literature to extract low-level image features and also approaches to connect these low-level features with high-level semantics. One of these approaches is called Bag-of-Features which is studied in the thesis. In the Bag-of-Features approach, the images are described using a visual codebook. The codebook is built from the descriptions of the image patches using clustering. The images are described by matching descriptions of image patches with the visual codebook and computing the number of matches for each code. In this thesis, unsupervised visual object categorisation using the Bag-of-Features approach is studied. The goal is to find groups of similar images, e.g., images that contain an object from the same category. The standard Bag-of-Features approach is improved by using spatial information and visual saliency. It was found that the performance of the visual object categorisation can be improved by using spatial information of local features to verify the matches. However, this process is computationally heavy, and thus, the number of images must be limited in the spatial matching, for example, by using the Bag-of-Features method as in this study. Different approaches for saliency detection are studied and a new method based on the Hessian-Affine local feature detector is proposed. The new method achieves comparable results with current state-of-the-art. The visual object categorisation performance was improved by using foreground segmentation based on saliency information, especially when the background could be considered as clutter.
Resumo:
Denne avhandlinga er resultatet av eit behov for å forske på og utvikle ein didaktikk for tekstilfaget ved Folkekunststudiet, Institutt for folkekultur, Høgskolen i Telemark, Noreg. Studiet med folkekunst som fagfelt er eit relativt ungt studium på høgskolen, som vart etablert i 1984. Problemstillinga i denne avhandlinga er korleis ein kan utvikle ein forskingsbasert didaktikk der dei grunnleggjande prinsippa som særmerkjer den tradisjonelle folkekunsten, vert tekne vare på. I arbeidet med avhandlinga har eg prøvd på å klårgjere problemstillinga ut frå ulike perspektiv. Forskingsarbeidet har fokus på kommunikasjon og arbeidsmåtar i ljos av ulike teoriar. Det er ei hermeneutisk tilnærming som er vald for den didaktiske forståinga. Det fyrste drøftingstemaet har søkjeljos på kommunikasjon og dialog ved vidareføring av tekstil folkekunst. Både estetiske, teoretiske, praktiske og sosiale aspekt er nedfelte i læreplanen for studiet og skal utgjere grunnlaget for kommunikasjon og arbeidsmåtar. I den skapande og kopierande prosessen er det utvikla språklege reiskapar for både den sosiale og den estetiske sida der den teoretiske og praktiske faktoren er integrert. Møte med døme på tekstile tradisjonar så vel som praktisk forming av tekstilar har ført til refleksjon og dialog som involverer kontemplasjon, korrespondens og imaginasjon. Det andre temaet som er drøfta, er vidareføring av tradisjonelt visuelt formspråk. Her er merksemda retta mot kva som har skjedd formalt med ei gruppe tradisjonelle formelement i tekstilar i den institusjonelle vidareføringa over eit lengre tidsperspektiv. Resultatet syner at mange tradisjonelle formelement er borte frå den institusjonelle produksjonen. Formelementa kan ha fått ei meir naturalistisk utforming, eller dei er overførte til andre tradisjonelle tekstilteknikkar enn dei som var utgangspunktet. Rombeforma i den institusjonelle produksjonen er utført i færre variasjonar og kombinasjonar enn i den tradisjonelle produksjonen. Konklusjonen på drøftingstemaet er at spelereglar og spatialitet i høve til den formale komponenten i utvalet med tradisjonelle tekstilar ikkje er vidareført i alle gruppene av institusjonelle produkt. Resultatet kan få innverknad og fylgjer for utforming av ein framtidig didaktikk for faget. Arbeidsmåte og erfaring frå vidareføring av tekstile tradisjonar er det tredje temaet som er drøfta i avhandlinga. Kopiering og skapande prosessar er arbeidsmåtar som er brukte ved studiet i dag, og dei utgjer grunnlag for drøftingar i relasjon til vidareføring og erfaring. Konklusjonen er at i den skapande prosessen korrigerer tradisjonen utforminga, medan i kopiprosessen er eigen stilvilje og improvisering resultat av prosessane. Personar som deltek i prosessane, har sett seg sjølve og si historiske forankring inn i spelet, der visuelt og verbalt språk er resultat av integrasjon av tradisjonar. Dei tre drøftingstemaa utgjer grunnlaget for at didaktikk for folkekunst og tekstil kan bli intersubjektiv forståing av kva ein didaktikk for vidareføring av folkekunst med vekt på tekstil kan vere i utdanninga i dag. Indre og ytre dialog i skapande og kopierande prosessar femner om estetiske, materielle og tekniske faktorar sett i høve til spelereglar, spelerom, spatialitet og samspel i møte med tekstile tradisjonar. Samla utgjer det ein forskingsbasert didaktikk for faget der den overordna intensjonen er samtykke mellom tradisjon og spel.
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Toimituskyky on yrityksen suorituskykyä kuvaava tekijä, jolla on merkittävä vaikutus asiakastyytyväisyyteen, erityisesti valmistusteollisuudessa. Toimituskyky muodostuu materiaalin saatavuudesta ja logistisen järjestelmän toimitusvarmuudesta, joten hyvä toimituskyky edellyttää materiaalipuutteiden hallintaa. Tämän diplomityön tavoitteena on esittää, miten toimituskykyä voidaan kehittää tilaus-toimitusprosessin materiaalipuutteita hallitsemalla. Tutkimus toteutettiin konstruktiivisella tutkimusotteella case-tutkimuksena havainnoimalla toimintaa case-yrityksessä sekä analysoimalla case-yrityksen kirjallista materiaalia ja arkistoja. Yrityksessä havaittuja materiaalipuutteisiin liittyviä ongelmia tarkasteltiin tilaus-toimitusprosessin näkökulmasta prosessijohtamisen ja systemaattisen ongelmanratkaisun teorioiden avulla. Tutkimuksen tuloksena laadittiin kolme käytännönläheistä ratkaisuehdotusta havaittuihin ongelmiin; (1) materiaalipuutteiden syy-seuraussuhteita kuvaavat ongelma-syy-seurausketjut, (2) materiaalipuutteiden ongelmanratkaisumalli systemaattisen ongelmanratkaisun tueksi sekä (3) visuaalinen tilaus-toimitusprosessimalli, joka painottaa osaprosessien yhteyttä koko prosessin toimituskykyyn ja toimitusvarmuuteen. Tulosten mukaan materiaalipuutteet tulisi käsittää prosessin laatuvirheinä, jotka antavat arvokasta tietoa siitä, että prosessissa on laatuongelmia. Tulosten perusteella yrityksen toimituskykyä voidaan kehittää havainnoimalla tilaus-toimitusprosessin laatuvirheitä, selvittämällä laatuvirheiden syy-seuraussuhteet systemaattisesti ongelmanratkaisumallia hyödyntäen sekä toimimalla prosessiajattelun mukaisesti tilaus-toimitusprosessin toimituskyvyn jatkuvaa parantamista tavoitellen. Tutkimusongelman tarkastelutapaa ja työn tuloksia voidaan soveltaa samankaltaisiin tapauksiin, joissa tilaus-toimitusprosessin laatuvirheet, esimerkiksi materiaalipuutteet, paljastavat kehittämistä vaativia epäkohtia prosessin toimintatavoissa. Tilaus-toimitusprosessin toimituskykyä voidaan kehittää vain, jos panostetaan ajan hallintaan ja kykyyn toimia asiakaslupausten ja sopimusten mukaisesti.
Resumo:
An augmented reality (AR) device must know observer’s location and orientation, i.e. observer’s pose, to be able to correctly register the virtual content to observer’s view. One possible way to determine and continuously follow-up the pose is model-based visual tracking. It supposes that a 3D model of the surroundings is known and that there is a video camera that is fixed to the device. The pose is tracked by comparing the video camera image to the model. Each new pose estimate is usually based on the previous estimate. However, the first estimate must be found out without a prior estimate, i.e. the tracking must be initialized, which in practice means that some model features must be identified from the image and matched to model features. This is known in literature as model-to-image registration problem or simultaneous pose and correspondence problem. This report reviews visual tracking initialization methods that are suitable for visual tracking in ship building environment when the ship CAD model is available. The environment is complex, which makes the initialization non-trivial. The report has been done as part of MARIN project.
Resumo:
The number of persons with visual impairment in Tanzania is estimated to over 1.6 million. About half a million of these persons are children aged 7-13. Only about 1% of these children are enrolled in schools. The special schools and units are too few and in most cases they are far away from the children’s homes. More and more regular schools are enrolling children with visual impairment, but the schools lack financial resources, tactile teaching materials and trained special education teachers. Children with visual impairment enrolled in regular schools seldom get enough support and often fail in examinations. The general aim of this study was to contribute to increased knowledge and understanding about how teachers can change their teaching practices and thus facilitate the learning of children with visual impairment included in regular classrooms as they participate in an action research project. The project was conducted in a primary school in a poor rural region with a high frequency of blindness and visual impairment. The school was poorly resourced and the average number of pupils per class was 90. The teachers who participated in the collaborative action research project were the 14 teachers who taught blind or visually impaired pupils in grades 4 and 6, in total 6 pupils. The action research project was conducted during a period of 6 months and was carried out in five cycles. The teachers were actively involved in all the project activities; identifying challenges, planning solutions, producing teaching materials, reflecting on outcomes, collaborating and evaluating. Empirical data was collected with questionnaires, interviews, observations and focus group discussions. The findings of the study show that the teachers managed to change their teaching practices through systematic reflection, analysis and collaboration. The teachers produced a variety of tactile teaching materials, which facilitated the learning of the pupils with visual impairment. The pupils learned better and felt more included in the regular classes. The teachers gained new knowledge and skills. They grew professionally and started to collaborate with each other. The study contributes to new knowledge of how collaborative action research can be conducted in the area of special education in a Tanzanian school context. The study has also relevance to the planning of school-based professional development programs and teacher education programs in Tanzania and in other low-income countries. The results also point at strategies which can promote inclusion of children with disabilities in regular schools.
Evaluation of radioinduced damage and repair capacity in blood lymphocytes of breast cancer patients
Resumo:
Genetic damage caused by ionizing radiation and repair capacity of blood lymphocytes from 3 breast cancer patients and 3 healthy donors were investigated using the comet assay. The comets were analyzed by two parameters: comet tail length and visual classification. Blood samples from the donors were irradiated in vitro with a 60Co source at a dose rate of 0.722 Gy/min, with a dose range of 0.2 to 4.0 Gy and analyzed immediately after the procedure and 3 and 24 h later. The basal level of damage and the radioinduced damage were higher in lymphocytes from breast cancer patients than in lymphocytes from healthy donors. The radioinduced damage showed that the two groups had a similar response when analyzed immediately after the irradiations. Therefore, while the healthy donors presented a considerable reduction of damage after 3 h, the patients had a higher residual damage even 24 h after exposure. The repair capacity of blood lymphocytes from the patients was slower than that of lymphocytes from healthy donors. The possible influence of age, disease stage and mutations in the BRCA1 and BRCA2 genes are discussed. Both parameters adopted proved to be sensitive and reproducible: the dose-response curves for DNA migration can be used not only for the analysis of cellular response but also for monitoring therapeutic interventions. Lymphocytes from the breast cancer patients presented an initial radiosensitivity similar to that of healthy subjects but a deficient repair mechanism made them more vulnerable to the genotoxic action of ionizing radiation. However, since lymphocytes from only 3 patients and 3 normal subjects were analyzed in the present paper, additional donors will be necessary for a more accurate evaluation.
Resumo:
Master’s thesis Biomass Utilization in PFC Co-firing System with the Slagging and Fouling Analysis is the study of the modern technologies of different coal-firing systems: PFC system, FB system and GF system. The biomass co-fired with coal is represented by the research of the company Alstom Power Plant. Based on the back ground of the air pollution, greenhouse effect problems and the national fuel security today, the bioenergy utilization is more and more popular. However, the biomass is promoted to burn to decrease the emission amount of carbon dioxide and other air pollutions, new problems form like slagging and fouling, hot corrosion in the firing systems. Thesis represent the brief overview of different coal-firing systems utilized in the world, and focus on the biomass-coal co-firing in the PFC system. The biomass supply and how the PFC system is running are represented in the thesis. Additionally, the new problems of hot corrosion, slagging and fouling are mentioned. The slagging and fouling problem is simulated by using the software HSC Chemistry 6.1, and the emissions comparison between coal-firing and co-firing are simulated as well.
Resumo:
Reproductive fish behavior is affected by male-female interactions that stimulate physiological responses such as hormonal release and gonad development. During male-female interactions, visual and chemical communication can modulate fish reproduction. The aim of the present study was to test the effect of visual and chemical male-female interaction on the gonad development and reproductive behavior of the cichlid fish Nile tilapia, Oreochromis niloticus (L.). Fifty-six pairs were studied after being maintained for 5 days under one of the four conditions (N = 14 for each condition): 1) visual contact (V); 2) chemical contact (Ch); 3) chemical and visual contact (Ch+V); 4) no sensory contact (Iso) - males and females isolated. We compared the reproductive behavior (nesting, courtship and spawning) and gonadosomatic index (GSI) of pairs of fish under all four conditions. Visual communication enhanced the frequency of courtship in males (mean ± SEM; V: 24.79 ± 3.30, Ch+V: 20.74 ± 3.09, Ch: 0.1 ± 0.07, Iso: 4.68 ± 1.26 events/30 min; P < 0.05, two-way ANOVA with LSD post hoc test), induced spawning in females (3 spawning in V and also 3 in Ch+V condition), and increased GSI in males (mean ± SEM; V: 1.39 ± 0.08, Ch+V: 1.21 ± 0.08, Ch: 1.04 ± 0.07, Iso: 0.82 ± 0.07%; P < 0.05, two-way ANOVA with LSD post hoc test). Chemical communication did not affect the reproductive behavior of pairs nor did it enhance the effects of visual contact. Therefore, male-female visual communication is an effective cue, which stimulates reproduction among pairs of Nile tilapia.
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Alcohol dependence poses a serious medical and sociological problem. It is influenced by multiple environmental and genetic factors, which may determine differences in alcohol metabolism. Genetic polymorphism of the enzymes involved in alcohol metabolism is highly ethnically and race dependent. The purpose of this study was to investigate the differences, if present, in the allele and genotype frequency of alcohol dehydrogenase 1B (ADH1B), ADH1C and the microsomal ethanol-oxidizing system (MEOS/CYP2E1) between alcohol-dependent individuals and controls and also to determine if these genotypes cause a difference in the age at which the patients become alcohol dependent. The allele and genotype frequencies of ADH1B, ADH1C, and CYP2E1 were determined in 204 alcohol dependent men and 172 healthy volunteers who do not drink alcohol (control group). Genotyping was performed by PCR-RFLP methods on white cell DNA. ADH1B*1 (99.3%) and ADH1C*1 (62.5%) alleles and ADH1B*1/*1 (N = 201) and ADH1C*1/*1 (N = 85) genotypes were statistically more frequent among alcohol-dependent subjects than among controls (99.3 and 62.5%, N = 201 and 85 vs 94.5 and 40.7%, N = 153 and 32, respectively). Differences in the CYP2E1 allele and genotype distribution between groups were not significant. The persons with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes became alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes (28.08, 25.67 years vs 36.0, 45.05, 34.45 years, respectively). In the Polish men examined, ADH1C*1 and ADH1B*1 alleles and ADH1C*1/*1 and ADH1B*1/*1 genotypes favor alcohol dependence. The ADH1B*2 allele may protect from alcohol dependence. However, subjects with ADH1C*1/*1 and CYP2E1*c1/*c2 genotypes become alcohol dependent at a considerably younger age than the subjects with ADH1C*1/*2, ADH1C*2/*2 and CYP2E1*c1/*c1 genotypes.
Resumo:
Response Surface Methodology (RSM) was applied to evaluate the chromatic features and sensory acceptance of emulsions that combine Soy Protein (SP) and red Guava Juice (GJ). The parameters analyzed were: instrumental color based on the coordinates a* (redness), b* (yellowness), L* (lightness), C* (chromaticity), h* (hue angle), visual color, acceptance, and appearance. The analyses of the results showed that GJ was responsible for the high measured values of red color, hue angle, chromaticity, acceptance, and visual color, whereas SP was the variable that increased the yellowness intensity of the assays. The redness (R²adj = 74.86%, p < 0.01) and hue angle (R²adj = 80.96%, p < 0.01) were related to the independent variables by linear models, while the sensory data (color and acceptance) could not be modeled due to a high variability. The models of yellowness, lightness, and chromaticity did not present lack of fit but presented adjusted determination coefficients bellow 70%. Notwithstanding, the linear correlations between sensory and instrumental data were not significant (p > 0.05) and low Pearson coefficients were obtained. The results showed that RSM is a useful tool to develop soy-based emulsions and model some chromatic features of guava-based emulsions through RSM.
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Structural differences such as abnormalities, damage and free spaces in seeds may affect germination. The aim of this study was to study the relationship between eggplant seed morphology and seed germination. Ten seed lots of the eggplant cultivar Embu were evaluated by X-ray image analysis and the germination test. Seed image analysis was performed by Image Pro Plus® software and the whole seed area and free space between the embryo and endosperm were measured. The internal seed area filled by the embryo and endosperm was calculated from the difference between the whole seed and free space areas. Based on these results and visual seed analysis, seeds were classified into three categories and information on germination was obtained for each one. X-ray image analysis provides a perfect view of the internal seed parts and for seed morphology studies. An increase in seed area filled by the endosperm and embryo does not improve seed germination. Mechanical seed damage and deteriorated tissues can adversely affect seed germination.
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The quality of the mother-child relationship was examined in relation to joint planning, maternal teaching strategies, maternal emotional support, mutual positive affect and attachment security. Fifty-five grade five children and their mothers participated in a laboratory session comprised of various activities and completed questionnaires to evaluate attachment security. Joint planning and social problem solving were assessed observationally during an origami task. Problem solving effectiveness was unrelated to maternal teaching strategies, maternal encouragement and mutual positive affect. A marginally significant relationship was found between maternal encouragement and active child participation. Attachment security was found to be significantly related to sharing of responsibility during local planning, but only for child autonomous performance. An examination of conditional probabilities revealed that mutual positive affect did not increase the likelihood of subsequent mother-child dyadic regulation. However, mutual positive affect was found to be significantly related to both active child participation and dyadic regulation. The hypothesis predicting a mediational model was not supported. The implications of these findings in the theoretical and empirical literature were considered and suggestions for future research were made.
Resumo:
What research learning experiences do current students have as research assistants (RAs) in the Faculty of Education at Brock University? How do the experiences of research assistants contribute to the formation of a researcher identity and influence future research plans? Despite the importance of these questions, there seems to be very little research conducted or written about the experiences of research assistants as they engage in the research process. There are few resources to which research assistants or their advisors can refer regarding graduate student research learning experiences. The purpose of this study was to understand the kinds of learning experiences that 4 RAs (who are enrolled in the Faculty of Education at Brock University, St. Catharines, Ontario) have and how those experiences contribute to their identities as researchers. Through interviews with participants, observations of participants, and textual documents produced by participants, I have (a) discovered what 4 RAs have learned while engaged in one or more research assistantships and (b) explored how these 4 RAs' experiences have shaped their identities as new researchers. My research design provided a separate case study for each participant RA, including myself as a research participant. Then as a collective, I studied all 4 cases as a case study in itself in the form of a cross-analysis to identify similarities and differences between cases. Using a variety of writing forms and visual narratives, I analyzed and interpreted the experiences of my participants utilizing arts-based literature to inform my analysis and thesis format. The final presentation includes electronic diagrams, models, poetry, a newsletter, a website presentation, and other representational arts-based forms.This thesis is a resource for current and future research assistants who can learn from the research assistant experiences presented in the research. Faculty members who hire research assistants to assist them with their research will also benefit from reading about RAs' learning experiences from the RAs' perspective. The information provided in this thesis document is a resource to inform future policies and research training initiatives in faculty departments and offices at universities. Consequently, this thesis also informs researchers (experienced and inexperienced) about how to conduct research in ways that benefit all parties and provide insight into potential ways to improve research assistantship practices.