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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Regos aštrumo priklausomybės nuo apšvietos tyrimas / Investigation of visual acuity dependence on surface illumination

Tarasovienė, Jūratė 16 July 2014 (has links)
Šiame darbe analizuojama šviesos įtaka regos procesui. Išnagrinėta mokslinė literatūra žmogaus regos, ryškumo, kontrasto ir spalvų suvokimo bei regos aštrumo klausimais. Išanalizuoti žmogaus regos proceso ypatumai, regos fiziologija. Pristatomi pagrindiniai fotometriniai dydžiai bei jų sąsaja su regos sistema. Atliktas tyrimas, kurio metu nustatoma regos aštrumo priklausomybė nuo paviršiaus apšvietos. Tyrime dalyvavo 50 žmonių. Tiriamieji suskirstyti į dvi: 40-50 ir 51-60 metų amžiaus grupes. Tyrime nustatyta, tiriamųjų regos aštrumo priklausomybė nuo įvairių apšvietų, apskaičiuoti vidutiniai tyrimo duomenų rezultatai, pateikta, tyrimo eigoje išryškėjusi adaptacijos tamsai įtaka. Šie tyrimo duomenys pavaizduoti grafiškai. Analizuojant teorinę medžiagą pastebėta, kad Lietuvoje, tai mažai tyrinėta sritis. Gauti tyrimo rezultatai rodo, kad padarius didesnius, daug daugiau tiriamųjų, kriterijų, apimančius tyrimus, būtų galima gauti įdomių rezultatų. / The subject of the work is the investigation of the visual acuity dependence on surface illumination. This final work analyzes the influence of light to visual process. Scientific literature was studied to look into the issues of human’s eyesight, brightness, contrast and color perception and visual acuity. The features of the human visual process and physiology of human’s eyesight have been examined as well. The work introduces the main photometric values and their relation to the visual system. The investigation has been carried out to determine the dependence of visual acuity on the surface illumination with 50 people participating in it. The people were divided into two groups according to their age: 40-50 and 51-50. The average data of the results have been estimated and various deviations from the mean shown up during the investigation are graphically presented in the work. While studying the theoretical material it was noticed that this field is still a byway in Lithuania. The findings suggest that if deeper and more criteria spanning researches were carried out, more revealing results could be expected.
12

Manejo de irriga??o na cultura do tomateiro em campo, na regi?o de Serop?dica-RJ / Irrigation managemente in tomato crop under field conditions in Serop?dica,RJ

Monte, Jos? Ant?nio 15 February 2007 (has links)
Made available in DSpace on 2016-04-28T14:58:32Z (GMT). No. of bitstreams: 1 2007- Jose Antonio Monte.pdf: 871031 bytes, checksum: 637d77aaf96168f58214d17d66e559fd (MD5) Previous issue date: 2002-02-15 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / An experiment was conducted to evaluate the influence of the irrigation schedule on fruit production and quality, biomass production in the different parts of the plant, and the physiological growth parameters of the tomato plants, cultivar D?bora for salad, cultivated in the field, in a split plot design, in the Federal Rural University of Rio de Janeiro, from 21/09/2005 to 31/01/2006. The experiment was conducted with four treatments and four replications of different irrigation schedules, using a drip irrigation system with sprinklers spaced 0,3m with a water volume of 1,14 l.h-1. During the essay, six samplings of the plants were collected, for evalua tion of the plant development, through the growth analysis of the different parts of the plant. Mathematical equations were adjusted for the mass accumulation in root, stems, leaves and fruits, and for leaf area of plants. The analysis of the results showed that the irrigation schedule of three days caused lowers values of the physiological parameters, a tendency of reduction of big fruits production and higher number of small fruits. In these experimental conditions, the irrigation schedule of two days is the best recommendation for the farmer because the quality of the tomato production is the same of those under more frequent irrigation but with a smaller water use. / Com o objetivo de avaliar a influ?ncia do turno de rega na produ??o e qualidade de frutos, na acumula??o de fitomassa nas diferentes partes da planta, e na obten??o dos ?ndices fisiol?gicos de crescimento da cultura de tomateiro para mesa da cultivar D?bora, tipo longa vida, realizou-se um experimento em faixas, na Universidade Federal Rural do Rio de Janeiro, no per?odo de 21/09/2005 ? 31/01/2006. O experimento foi feito com quatro tratamentos consistindo de diferentes freq??ncias de irriga??o, atrav?s de um sistema de irriga??o localizada com emissores espa?ados de 0,3 m e de vaz?o correspondente a 1,14 l.h-1, tendo quatro repeti??es. Durante o experimento foram realizadas seis coletas de plantas para avaliar o desenvolvimento vegetal, atrav?s da an?lise do crescimento, em seis diferentes ?pocas ap?s o transplante. Foram ajustadas equa??es matem?ticas para o ac?mulo de massa, nas ra?zes, nos caules, nas folhas e nos frutos, e para a ?rea foliar das plantas. Analisando os resultados observou-se que o turno de rega com intervalo de tr?s dias entre irriga??es apresentou menores ?ndices fisiol?gicos, menor tend?ncia em produzir frutos grandes e apresentou maiores n?meros de frutos mi?dos. Nas condi??es experimentais, o turno de rega alternado de 2 dias foi o mais recomendado para o agricultor, por ter a mesma qualidade de produ??o de tomate apresentada pelos turnos de regas mais freq?entes, mas com menr gasto de ?gua.
13

Spausdintinio montažo plokščių surinkimo kokybės įvertinimas kompiuterine rega / Evaluation of Assembling Quality of Printed Circuit Boards Using Computer Vision

Zemblys, Raimondas 29 September 2008 (has links)
Elektronikos gamybos rinkoje produkcijos kokybei užtikrinti buvo pasikliaujama žmogaus vizualia apžiūra ir elektroniniais testais. Pasirodžius personaliniams kompiuteriams, gamybos pramonėje pradėta naudoti „kompiuterinė rega”. Procesas, kuriame naudojamas optinis vaizdo sensorius, pvz.: kamera, apibūdinamas kaip automatinė optinė kontrolė – AOK (angl. Automated Optical Inspection - AOI). Darbo tikslas - sukurti spausdintinio montažo plokščių kokybės įvertinimo sistemą panaudojant kompiuterinę regą, išrinkti spausdintinio montažo plokščių kokybės įvertinimui efektyviausius vaizdo apdorojimo algoritmus ir jų parametrus bei įvertinti jų efektyvumą. Taip pat nagrinėjama aplinkos veiksnių (apšvietimo, naudojamos techninės įrangos ir kt.) įtaka sistemos darbo efektyvumui. / Historically the electronics manufacturing market has relied on a combination of human visual inspection and electrical test methods to ensure product quality. With the advent of the personal computer, the use of "machine vision" in industrial applications gradually became more common. Process where optical sensors (i.e., cameras) are used to make specific pass/fail decisions is usually described as Automated Optical Inspection or AOI. There are discussed problems of designing AOI system in this paper. Main goal is to select most efficient image analysis algorithm and to study other parameters that have impact for designing reliable AOI system.
14

Paauglių pusiausvyros, paprastosios ir psichomotorinės reakcijos priklausomybė nuo regos lygio / The dependence of simple and psychomotor reaction and equilibrium maintenance of adolescents on the degree of visual impairment

Juodžbalienė, Vilma 18 January 2006 (has links)
Optimal interaction between vision and other somatosensory systems guaranties the control of human body segment stability and change in position. The lack of visual information causes changes in equilibrium, regulation of body segment position and in response to surrounding stimuli. The objective of the study: to carry out the research on the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, and to establish the possible manifestation of compensatory reactions of vestibular and proprioception sensory systems when vision disorders are being faced. To investigate the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, the sighted subjects, legally blind and totally blind subjects voluntarily participated in the study. A static posturography (or stabilography) method has been used for the equilibrium testing. A force plate and computerized equipment for analysis of the signals was applied for posturography. Centre of pressure coordinates have been started to be registered since the moment when the subject in bare feet stands on the force plate in the position required. Posturogram registration in every position of standing lasted 60 s. To investigate a simple reaction, we have employed an electromyoreflexometer, which consists of the equipment emitting light or sound signals, a response device and a unit for the data registration. The testing has been conducted during two parts when a... [to full text]
15

Galvos pozicijos nustatymas ekrano atžvilgiu, panaudojant ant galvos pritvirtintą kamerą / Tracking of Head Position Relative to the Screen using Head Mounted Camera

Borcovas, Evaldas 20 June 2012 (has links)
Tobulėjant kompiuteriams, ieškoma vis naujų galimybių informacijos perdavimui tarp vartotojo ir mašinos. Yra atliekama daug tyrimų žmogaus ir kompiuterio sąveikos – HCI (Human computer interaction) – srityje. Ieškoma naujų būdų bei metodų, kaip perduoti informaciją iš vartotojo kompiuteriui, ir atvirkščiai. Senesni metodai, tokie kaip įvestis pelės ir klaviatūros pagalba, išvestis vaizduoklio, projektoriaus bei spausdintuvo pagalba, yra optimizuojami. Siekiama surasti ergonomiškiausią įvesties, išvesties ir informacijos perdavimo metodą. / With the development of computers engineers are looking for new ways of commutation between user and machine. There are many researches done in human-computer interaction – HCI field. Engineers are always Ssearching for new ways, methods of transmitting information from user to machine and vice versa. Older methods, mouse and keyboard input, monitor, projector and printer output, are optimized. The aim of these studies is to find the most ergonomic input, output and communication method.
16

Paauglių pusiausvyros, paprastosios ir psichomotorinės reakcijos priklausomybė nuo regos lygio / The dependence of simple and psychomotor reaction and equilibrium maintenance of adolescents on the degree of visual impairment

Juodžbalienė, Vilma 18 January 2006 (has links)
Optimal interaction between vision and other somatosensory systems guaranties the control of human body segment stability and change in position. The lack of visual information causes changes in equilibrium, regulation of body segment position and in response to surrounding stimuli. The objective of the study: to carry out the research on the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, and to establish the possible manifestation of compensatory reactions of vestibular and proprioception sensory systems when vision disorders are being faced. To investigate the influence of the degree of visual impairment on equilibrium and simple and psychomotor reactions, the sighted subjects, legally blind and totally blind subjects voluntarily participated in the study. A static posturography (or stabilography) method has been used for the equilibrium testing. A force plate and computerized equipment for analysis of the signals was applied for posturography. Centre of pressure coordinates have been started to be registered since the moment when the subject in bare feet stands on the force plate in the position required. Posturogram registration in every position of standing lasted 60 s. To investigate a simple reaction, we have employed an electromyoreflexometer, which consists of the equipment emitting light or sound signals, a response device and a unit for the data registration. The testing has been conducted during two parts when a... [to full text]
17

Erdvinio vaizdo algoritmų palyginimas / Comparison of stereo vision algorithms

Abramovich, Alexander 17 July 2014 (has links)
Kompiuterinė erdvinė rega - tai erdvinės informacijos gavimas iš skaitmeninių vaizdų. Ši mokslo sritis yra ganėtinai nauja ir jos populiarumas auga. Kompiuterinė erdvinė rega naudojama robotikoje, pramonėje, buityje ir kitose srityse. Pagrindinis magistro darbo tikslas yra išanalizuoti ir palyginti erdvinio vaizdo algoritmus. Šiam tikslui pasiekti yra keliami šie uždaviniai: suklasifikuoti erdvinio vaizdo algoritmus, apžvelgti jų sudarymo metodus, sukurti erdvinio vaizdo algoritmų įvertinimo metodiką ir vadovaujantis ja įvertinti erdvinio vaizdo algoritmus. Vadovaujantis kitų autorių moksliniais darbais, erdvinės regos algoritmai, pagal jų veikimo principus buvo suklasifikuoti ir išskirti i dvi grupės: lokalinius ir globalius. Iš kiekvienos grupės buvo išskirti keli algoritmai, su kuriais ir buvo atliekamas tyrimas. Iš lokalinių buvo išrinktas bazinis lokalinis algoritmas su skirtingais matematiniais sprendimais, o iš globalių buvo paimtas dinaminis programavimas. Išvardintų algoritmų palyginimui buvo sukurta įvertinimo metodika. Pagrindiniai jos kriterijai yra koreliacijos koeficientas ir algoritmo atlikimo laikas. Visi išvardinti algoritmai buvo išbandyti vadovaujantis įvertinimo metodika. Remiantis bandymų rezultatais ir metodika buvo išrinkti geriausi rezultatai. Atliktų eksperimentinių tyrimų rezultatai parodo, kad išbandyti algoritmai nėra tobuli, bet ir jie tinka vartojimui, nors ir su tam tikrais apribojimais. Taip pat algoritmų netobulumas parodo, kad ne... [toliau žr. visą tekstą] / Computer stereo vision is a receiving of stereo information from digital images. This field of science is rather new and its popularity is increasing rapidly. Computer stereo vision is applied in robotics, manufacturing industry, everyday life and other spheres. The aim of the Thesis is to analyze and compare the stereo vision algorithms. In order to achieve the aim of the Research, the following tasks are determined: to classify the stereo vision algorithms, to study the methods of algorithm design, to create the method of assessment of stereo vision algorithms and to assess the stereo vision algorithms basing on the ground of this method. Basing on academic works of various authors, the stereo vision algorithms are classified and divided into two groups in accordance with the modes of their functioning: local and global algorithms. Several algorithms are chosen from each group. A based local algorithm with different mathematical solutions is chosen from the group of local algorithms, and the dynamic programming is chosen from the group of the global algorithms. The chosen algorithms are tested in the course of the Research. To compare the mentioned algorithms, the assessment method is prepared, the main criteria of which are the correlation index and the running time of algorithm. All abovementioned algorithms are tested by the means of the method of assessment. The best results are chosen basing on the method and results of the tests. The results of the conducted... [to full text]
18

Diversidade genética, frequência de irrigação e doses de polímero hidrorretentor na produção de goiabeira / Genetic diversity, irrigation frequency and doses of hydroretentory polymer in guava production

Pereira, Eduardo Castro 23 February 2017 (has links)
Submitted by Socorro Pontes (socorrop@ufersa.edu.br) on 2017-07-25T14:20:23Z No. of bitstreams: 1 EduardoCP_TESE.pdf: 2355961 bytes, checksum: 8690e3719791c5d601f48f7ac2d5517a (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-07-25T14:45:27Z (GMT) No. of bitstreams: 1 EduardoCP_TESE.pdf: 2355961 bytes, checksum: 8690e3719791c5d601f48f7ac2d5517a (MD5) / Made available in DSpace on 2017-07-25T14:46:06Z (GMT). No. of bitstreams: 1 EduardoCP_TESE.pdf: 2355961 bytes, checksum: 8690e3719791c5d601f48f7ac2d5517a (MD5) Previous issue date: 2017-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of water-repellent polymer in agriculture has been growing in recent years because it has the capacity to retain and provide water slowly to the plants and still be a conditioner for soils. However, the lack of studies for the guava crop and its ideal dose for use in substrates makes its use limited in this context. Another important aspect of guava culture is the study of diversity, which is one of the most important indicators evaluated by plant breeders in the initial phase of a breeding program. The aim of this work was to evaluate the effects of different hydrogel doses and irrigation shifts on the growth of guinea - pig grafts and to evaluate the diversity of guava accesses using morphoagronomic descriptors for qualitative variables in the plant and qualitative and quantitative variables in the fruits. In the experiment I, the experimental design was a randomized block design, with four replications, in the 4 x 3 factorial scheme, corresponding to four doses of the Biogel Aqua Plus® hydrogelent polymer (0.0, 1.0, 2.5 e 5.0 g L-1) and three irrigation shifts (T1 - daily irrigation; T2 - irrigation on alternate days and T3 - irrigation every two days). The following variables were evaluated: height of the portagrafts (cm); Lap diameter (mm); Number of leaves per plant; Dry shoot mass (g), root dry mass weight (g) and total dry weight weight (g); Height / diameter ratio of the neck; Dry height / dry matter ratio; Dry mass ratio of aerial part / root dry mass and content index of chlorophyll. The 1g L-1 dose of the hydrogel incorporated into the substrate is indicated for the production of guinea-pig portagrafts and with the incorporation thereof, irrigation of the guinea-pig portagrafts can be performed frequently within one day. In the experiment II, the morphoagronomic descriptors were evaluated in 84 accessions of seminiferous guava trees cultivated at the experimental farm of UFERSA (Alagoinha), in the region of Mossoró-RN. We evaluated 26 descriptors in the plant, observed in four quadrants. The evaluation through morphoagronomic descriptors showed a partial agreement between the clusters methods studied. The technique of genetic dissimilarity using multicastropic characteristics was effective to investigate the diversity among the accessions of guava trees, showing that the population has wide genetic variability. The evaluation through morphoagronomic descriptors showed a partial agreement between the clusters methods studied. The technique of genetic dissimilarity using multicastropic characteristics was effective to investigate the diversity among the accessions of guava trees, showing that the population has wide genetic variability. In the experiment III, the quality and the morphoagronomic characteristics of fruits of 37 guinea-fowl accesses propagated semen, cultivated in the experimental farm of Ufersa (Alagoinha), in the region of Mossoró-RN, were evaluated. Five fruits were collected from each access and transported to the UFERSA post-harvest laboratory at the CPVSA. For the quality variables, 11 parameters were evaluated. Morphological variables were analyzed according to 13 descriptors. The Tocher optimization clustering methods and the UPGMA method demonstrated wide divergence in the division of groups into the quantitative characteristics. In the grouping carried out for the qualitative variables, the Tocher and UPGMA methods observed great variability among the accessions. The fruit length, fruit weight, firmness, septal shape, fruit shape and color of the epidermis were the main contributors to dissimilarity among the accessions / A utilização do polímero hidrorretentor na agricultura vem crescendo nos últimos anos pelo fato de ter a capacidade de reter e disponibilizar água lentamente para as plantas e ainda ser um condicionador para os solos. Porém, a falta de estudos para a cultura da goiaba e sua dose ideal para utilização nos substratos torna seu uso limitado nesse contexto. Outro aspecto importante da cultura da goiabeira é o estudo da diversidade, que é um dos mais importantes indicadores avaliados por melhoristas de plantas na fase inicial de um programa de melhoramento genético. Portanto, necessita-se de algumas atividades para caracterizá-los. Frente ao exposto, teve-se por objetivo avaliar os efeitos de diferentes doses de hidrogel e turnos de rega na produção de portaenxertos de goiabeira, avaliar os descritores multicategóricos/morfoagrônomicos como método de avaliação da diversidade genética. No experimento I, o delineamento experimental foi em blocos casualizados, com quatro repetições, no esquema fatorial 4 x 3, correspondendo a quatro doses do polímero hidrorretentor Biogel Aqua Plus® (hidrogel) (0,0; 1,0; 2,5 e 5,0 g L-1) e três turnos de rega (T1 - irrigação diária; T2 - irrigação em dias alternados e T3 - irrigação a cada dois dias). Foram avaliadas as seguintes variáveis: altura dos portaenxertos (cm); diâmetro do colo (mm); número de folhas por planta; massa seca da parte aérea (g), peso da massa seca das raízes (g) e peso da massa seca total (g); relação altura/diâmetro do colo; relação altura/massa seca da parte aérea; relação massa seca da parte aérea/massa seca da raiz e o índice de conteúdo de clorofila. A dose de 1g L-1 do hidrogel incorporado ao substrato é indicada para a produção de portaenxertos de goiabeira, e com sua incorporação a irrigação dos portaenxertos de goiabeira pode ser realizada com frequência em intervalo de um dia. No experimento II, foram avaliados os descritores morfoagronômicos em 84 acessos de goiabeiras propagadas seminalmente, cultivadas na fazenda experimental da Ufersa (Alagoinha), na região de Mossoró-RN. Foram avaliados 26 descritores na planta, observados em quatro quadrantes. A avaliação através de descritores morfoagronômicos mostrou uma concordância parcial entre os métodos de agrupamentos estudados. A técnica de dissimilaridade genética utilizando características multicategóricas foi eficaz para investigar a diversidade entre os acessos de goiabeiras, mostrando que a população possui ampla variabilidade genética. No experimento III, avaliou-se a qualidade e as características morfoagronômicas de frutos de 37 acessos de goiabeira propagadas seminalmente, cultivadas na fazenda experimental da Ufersa (Alagoinha), na região de Mossoró-RN. Foram colhidos cinco frutos de cada acesso e transportados para o laboratório de pós-colheita da Ufersa, no CPVSA. Para as variáveis de qualidade, avaliou-se 11 parâmetros. As variáveis morfológicas foram analisadas de acordo com 13 descritores. Os métodos de agrupamento de otimização de Tocher e o método UPGMA demonstraram ampla divergência na divisão dos grupos para as características quantitativas. No agrupamento realizado para as variáveis qualitativas os métodos de Tocher e UPGMA observaram grande variabilidade entre os acessos. Os caracteres comprimento do fruto, peso do fruto, firmeza, formato das sépalas, forma do fruto e coloração da epiderme foram os que mais contribuíram para a dissimilaridade entre os acessos / 2017-07-24
19

Greitas ir tikslus objekto parametrų nustatymas mašininės regos sistemose / Fast and accurate object parameters detection in machine vision system

Kazakevičius, Tadas 10 June 2011 (has links)
Objekto atpažinimas ir pozicijos nustatymas gali būti pritaikomas daugeliui pramonėje egzistuojančių uždavinių. Šio darbo pagrindinis tikslas yra sukurti mašininės regos sistemą, kuria būtų galima greitai ir tiksliai rasti objekto poziciją pagal pasirinktą objekto modelį. Šiame darbe gilinamasi į GPU veikimo principus ir privalumus apdorojant vaizdus GLSL programavimo kalba. Apžvelgiami praktikoje taikomų metodų, skirtų objekto pozicijai nustatyti, veikimo principai, jų privalumai ir trūkumai. Taip pat šiame darbe aprašomas suformuotas ir įgyvendintas realaus laiko metodas, naudojantis GPU teikiama sparta atlikti vartotojo pasirinkto modelio paiešką. Pabaigoje pateikiami pasiekti įgyvendinto metodo spartos rodikliai, privalumai ir trūkumai. Darbą sudaro: įvadas, mašininėje regoje pasitaikančių problemų tyrinėjimas, objekto paieškos metodų apžvalga, darbo su grafinėmis vaizdo plokštėmis privalumai ir trūkumai, objekto paieškos su grafine vaizdo plokšte metodas, pasiekti rezultatai, išvados ir literatūros sąrašas. Darbo apimtis – 53 p. teksto be priedų, 30 pav., 2 lent., 26 literatūros šaltiniai. / Object recognition and parameter detection could be used in many areas from electronics to food industry. One of the most important problems in laser industry is to transform laser work trajectories based on constant object model. In the real life applications model could be rotated or translated due to the fact that object must be put in laser work area. The translation and rotation of object must be found to fit user defined constant model. There are many methods for object parameters detection, but image processing tasks require a lot of computing power. Recent research on image processing with graphics processing units - GPU, shows huge performance results compared with central processing units – CPU. The purpose of this work is to find out the main fundamentals for fast and accurate object parameter detection in machine vision systems. In this work it is focused on object parameter detection with GPU. Moreover, the analysis and comparison of different object parameters detection methods are proposed. Object parameter detection system was implemented with C++ and GLSL shading language, thus the system could be adapted to different computer hardware and operating systems. Work size – 53 p. text, 30 illustrations, 2 tables, 26 bibliographic sources.

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