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

Metodologia para automação de inspeção visual de bolsas para coleta de sangue / Methodology to automation visual inspection for blood bags

Adorni, Cássio Avelino 28 July 2008 (has links)
As bolsas para coleta de sangue necessitam cuidados técnicos que assegurem sua esterilidade biológica durante o processo de fabricação até a entrega do produto final. As bolsas para coleta de sangue não devem conter qualquer tipo de resíduo, para que o seu uso ou conteúdo não seja comprometido causando diversos transtornos. É preciso eliminar o risco de contaminação; no entanto muitas empresas fazem a inspeção de bolsas para coleta de sangue visualmente, a olho nu, por funcionários treinados no uso de equipamento simples, o qual não pode garantir que todas as bolsas estejam livres de resíduos, por depender do fator humano. Para assegurar a esterilização das bolsas comercializadas, este trabalho propõe uma metodologia para automação de um sistema de visão computacional baseado em conjunto de técnica de extração de características de imagens e reconhecimento de padrões para detectar resíduos em imagens de bolsas para coleta de sangue durante o processo de fabricação, e assim, melhorar a qualidade das bolsas comercializadas. Os resíduos encontrados nas imagens capturadas se apresentam como componentes de alta freqüência. A metodologia proposta utiliza a Transformada Wavelet (Wavelet de Haar) em dois níveis de decomposição, como filtro passa - alta para destacar as altas freqüências, e assim detectar a existência de resíduos nas imagens capturadas. Os resultados obtidos com a inspeção visual manual realizada em bolsas para coleta de sangue, mostram que existem resultados divergentes na análise de uma mesma bolsa, o que reforça a necessidade de automatização dessa tarefa para que sejam obtidos resultados mais uniformes com padrões definidos, e dessa maneira melhorar a qualidade das bolsas comercializadas para coleta de sangue. / The blood bags require technician attention to assure its biological sterility in the process of manufacture and in the final product. The blood bags must not contain any type of waste, so that its use or content is not compromised causing various disorders; it is necessary to eliminate any contamination risk; however many companies perform a visually inspection of the blood bags, by naked eye, by trained employees in the use of a simple equipment, which cannot guarantee that all the bags are residue-free because depending on the human factor. The residues showed on the pictures were characterized as high frequency components. So the proposed methodology applies two levels decomposition of Haar´s Wavelet as high pass filter to evidence high frequencies, and to evidence the residues at the pictures and to evidence the existence of residues on the captured pictures. To assure the sterilization of the commercialized blood bags, this work propose a methodology of an automated computational system based in a group of techniques of image characteristics extraction and recognition patterns to detect residues in blood bag images in the process of manufacture, in order to improve the quality of the commercialized blood bags.This technique is used as high-pass filter, to detach the high frequencies, using a Haar-wavelet in two decomposition levels. The results obtained with the manual visual inspection indicate that were found divergent results in the analysis of the same blood bag, which reinforces the necessity of the automation of this task in order to obtain more uniform results with defined standards.
22

Desempenho de dois índices visuais e da fluorescência a laser na detecção e avaliação da atividade de lesões de cárie em superfícies oclusais de dentes decíduos / Performance of two visual scoring systems and of laser fluorescence in detection, lesion estimation and activity assessment of occlusal caries in primary teeth

Mariana Minatel Braga 05 September 2008 (has links)
Os objetivos do presente estudo foram avaliar, em superfícies oclusais de dentes decíduos, o desempenho de dois índices visuais (Nyvad e International Caries Detection and Assessment System + activity lesions assessment ICDAS-II+ALA) para verificar: a) a profundidade e atividade de lesões de cárie, b) a habilidade do aparelho de fluorescência a laser de diferenciar lesões ativas e inativas e c) a associação de variáveis explicativas ligadas ao dente e à criança com a atividade de lesões de cárie. O estudo foi dividido em etapas: (1) avaliação dos índices visuais in vitro; (2) e em etapa in vivo; (3) avaliação da fluorescência a laser na detecção da atividade da lesão; (4) avaliação de variáveis relacionados à atividade de lesões de cárie. Para a etapa 1, 107 molares decíduos foram examinados por dois examinadores utilizando os índices visuais acima mencionados. Parte da amostra (n=69) foi submetida ao exame histológico para avaliação da profundidade das lesões. Foram calculados a reprodutibilidade dos índices e parâmetros associados à validade dos mesmos para estimativa da profundidade das lesões, além da associação entre os índices e com o exame histológico. Para a etapa 2, foram selecionadas 139 crianças entre 3 e 12 anos. Os molares decíduos dessas crianças (n=763) foram também examinados por dois examinadores usando os mesmos índices visuais. Os dentes exfoliados ou extraídos dessa amostra (n=50) foram examinados histologicamente para profundidade e atividade das lesões (com uso de corante indicar de pH). A reprodutibilidade e validade de critério dos índices foram verificadas. Para a etapa 3, os molares decíduos foram examinados com o aparelho de fluorescência a laser (DIAGNOdent) após 3s e 15s de secagem. A diferença entre as medidas nos dois tempos foi calculada. A associação das leituras com a severidade, atividade e pigmentação das lesões foi verificada. A validade do método foi verificada para os dentes exfoliados ou extraídos. Por fim, para a etapa 4, alguns parâmetros possivelmente relacionados com a atividade das lesões de cárie foram coletados por questionário e clinicamente. Uma análise multinível foi feita para verificar a associação desses parâmetros com a atividade das lesões de cárie classificadas pelos índices. Observou-se que os índices de cárie são comparáveis, apresentando boa reprodutibilidade e validade de critério para detectar lesões de cárie e estimar sua profundidade, tanto in vitro, como in vivo. Os sistemas também apresentam associação satisfatória para a avaliação da atividade das lesões, sendo que o ICDAS-II + ALA mostra uma tendência de superestimar essa atividade das lesões quando comparado ao índice de Nyvad. O método de fluorescência a laser é capaz de diferenciar lesões ativas de inativas classificadas pelo índice de Nyvad, sendo que a pigmentação não influencia isoladamente, a avaliação da atividade das lesões por esse método. Por fim, o tipo de dente e o acúmulo de placa madura, assim como a experiência de cárie e visita anterior ao dentista são variáveis, respectivamente do dente e da criança, associadas à presença de lesões ativas. / The aims of this study were to evaluate, in occlusal surfaces of primary teeth, the performance of two visual scoring systems (Nyvad e International Caries Detection and Assessment System + activity lesions assessment ICDAS-II+ALA) in assessing a) lesions depth and activity, b) the laser fluorescence ability in distinguishing active from inactive lesions and c) the association between independent variables related to the tooth and the child concerning caries activity status. This study was divided into stages: (1) evaluation of visual indices in vitro; (2) and also in an in vivo stage; (3) evaluation of laser fluorescence in caries lesion assessment; (4) evaluation of other variables related to caries activity. For phase 1, 107 primary molars were examined by two independent examiners using the scoring systems mentioned above. Some teeth (n=69) were evaluated concerning lesions depth in the histological examination. The reproducibility of the methods and some parameters related to their validity were calculated. Additionally, association between the indices and between each index and the histological examination were assessed. For the phase 2, 139 children aged 3 to 12-years were selected. Primary molars (n=763) were also examined by two independent examiners using the same visual systems. Exfoliated or extracted teeth from this sample (n=50) were examined histologically regarding the lesion depth and activity status (using a pH detector dye). The reproducibility and validity for both indices were assessed. For the phase 3, laser fluorescence examinations (DIAGNOdent) were performed after air-drying for 3s and 15s. The difference between the readings in these two periods of drying was calculated. The association between the laser fluorescence measurements and lesions severity, activity and staining was assessed. The validity was verified in the sample of extracted or exfoliated teeth. Finally, in the phase 4, some parameters possibly related to caries activity were collected clinically or by questionnaire. Multilevel analyses were performed to verify the association among these parameters and the lesions activity status classified by the visual systems. It was observed that the visual scoring indices are comparable and present good reproducibility and criterion validity in detecting caries lesions and estimating their depths, both in vitro and in vivo. The systems also show acceptable association concerning caries activity assessment. Besides, the ICDAS-II + ALA tends to overestimate lesions activity comparing to Nyvads system. The laser fluorescence is able to differentiate active from arrested lesions classified by the Nyvads criteria and the fissure discoloration does not interfere by itself in the caries activity assessment by this method. Finally, the tooth type and the presence of mature dental plaque on the lesions site, as well the anterior caries experience and the visit to the dentist are variables, respectively related to the tooth and the child, associated with the presence of active caries lesions.
23

Smartphone technology : everyday prompts for those with prospective memory difficulties following brain injury

Ferguson, Scott January 2013 (has links)
BACKGROUND: Prospective memory difficulties are one of the most common deficits following acquired brain injury. The application of smartphones as a compensatory aid to these difficulties has shown promising results. This study looked to investigate these benefits further. OBJECTIVE: The aims of this study were to investigate whether receipt of reminder prompts through ones smartphone improved completion of pre-planned tasks, in addition to whether it also had secondary implications for participant's wellbeing, confidence, independent functioning, and whether it had any impact on caregiver strain levels. METHOD: This study used an ABAB case series design with mild to moderate acquired brain injury. Task completion rates were monitored across four phases (prompts vs. no prompts). Quantitative questionnaires were administered pre, post and at three months follow up to assess coping with memory difficulties. A qualitative questionnaire explored the perceived impact of the smartphone reminders on everyday functioning, in addition to a 3 month follow up measure assessing attrition rates in smartphone use. RESULTS: Visual inspection analysis suggested greater task completion when reminders were provided. The quantitative questionnaires showed increased use of a Smartphone as reminder device post intervention and at follow up. A basic thematic analysis highlighted a perception that the smartphone system increased task completion, confidence in coping with memory demands, supported emotional wellbeing and reduced dependence on others. As a memory aid it was also less stigmatising and promoted dignity. The three month follow up questionnaire highlighted that all participants continued to use their smartphone as a memory aid. CONCLUSIONS: Use of a smartphone as a memory compensation aid may improve completion of pre-set tasks. Secondary benefits may include increased confidence in coping with memory demands, reduced dependence on others for help, and reduced anxiety or frustration around forgetting.
24

Estudo e desenvolvimento de antena de microfita aplicada à veículos aéreos não tripulados para inspeção em linhas de transmissão

Pereira, Thomas Tadeu de Oliveira 07 February 2018 (has links)
Submitted by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-04-25T19:00:54Z No. of bitstreams: 1 ThomasTOP_DISSERT.pdf: 5209914 bytes, checksum: dc0480e3c31cf33dad2055a2722ab763 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T16:53:46Z (GMT) No. of bitstreams: 1 ThomasTOP_DISSERT.pdf: 5209914 bytes, checksum: dc0480e3c31cf33dad2055a2722ab763 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2018-06-18T17:02:42Z (GMT) No. of bitstreams: 1 ThomasTOP_DISSERT.pdf: 5209914 bytes, checksum: dc0480e3c31cf33dad2055a2722ab763 (MD5) / Made available in DSpace on 2018-06-18T17:02:51Z (GMT). No. of bitstreams: 1 ThomasTOP_DISSERT.pdf: 5209914 bytes, checksum: dc0480e3c31cf33dad2055a2722ab763 (MD5) Previous issue date: 2018-02-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / In wireless communications, there is a growing need for more compact and portable systems. In this context, research related to the development of antennas has intensified in recent years, especially those related to microstrip antennas, since these have unique properties as well as several applications. In this work, two different antenna configurations were designed, an array of microstrip antennas for the transmitting device and a single element with an omnidirectional pattern for the receiver, according to the needs of the application. The antennas are designed by the Transmission Line Theory according to the frequency of radio operation and the electrical and physical properties of the substrates used. The results were obtained through simulations in the ANSYS HFSS® software, and the best results were used to fabricate the devices in order to validate the simulations performed. The results of the simulations reached the characteristics of the application, as the return losses of both antennas were in accordance with the frequency band of the application in the band ISM in 2.4 GHz, with respect to the behavior of the radiation, the antenna proposed to the transmitter had a gain of 6.1 dB, approximately three times greater than the commonly used dipole / monopole antenna. The experimental result of the loss of return was shown to be in agreement with the simulated standard, in spite of the frequency displacement, both antennas constructed were suitable for application in the radio control of the UAV, having the microstrip array 7.5 MHz of bandwidth in the band of application and the simple element proposed to the 58.5 MHz receiver. The antennas were then implemented in the radiofrequency system and a range test was performed in order to verify the communication of the devices, presenting satisfactory results. Thus, a flight is performed via software for visual inspection of transmission lines, aiming the collection of images for analysis / Em comunicações sem fio, existe uma crescente necessidade por sistemas mais compactos e portáteis. Nesse contexto, as pesquisas relacionadas ao desenvolvimento de antenas têm se intensificado nos últimos anos, em especial, as relacionadas às antenas de microfita, visto que estas possuem propriedades singulares, bem como diversas aplicações. Neste trabalho foram projetadas duas configurações distintas de antenas, um arranjo de antenas de microfita para o dispositivo transmissor e um elemento simples com padrão omnidirecional para o receptor, de acordo com as necessidades da aplicação. As antenas são projetadas pela Teoria da Linha de Transmissão de acordo com a frequência de operação do rádio e as propriedades elétricas e físicas dos substratos utilizados. Os resultados foram obtidos através de simulações no software ANSYS HFSS®, e os melhores resultados foram utilizados para fabricação dos dispositivos a fim de validar as simulações realizadas. Os resultados das simulações atingiram as características da aplicação, pois as perdas de retorno de ambas antenas apresentaram conformidade com a faixa de frequências da aplicação na banda ISM em 2,4 GHz, no que diz respeito ao comportamento da radiação, a antena proposta ao transmissor teve ganho de 6,1 dB, aproximadamente três vezes maior do que a antena dipolo/monopolo comumente utilizada. O resultado experimental do coeficiente de reflexão se mostrou concordante com o padrão simulado, apesar do deslocamento de frequência, ambas antenas construídas se adequaram para aplicação no rádio controle do VANT, tendo o arranjo de microfita 7,5 MHz de largura de banda na faixa de aplicação e o elemento simples proposto ao receptor 58,5 MHz. Em seguida, as antenas foram implementadas no sistema de radiofrequência e foi realizado um teste de alcance a fim de averiguar a comunicação dos dispositivos, apresentando resultados satisfatórios. Desse modo, um voo foi realizado para inspeção visual de linhas de transmissão, visando a coleta de imagens para análise / 2018-04-25
25

Metodologia para automação de inspeção visual de bolsas para coleta de sangue / Methodology to automation visual inspection for blood bags

Cássio Avelino Adorni 28 July 2008 (has links)
As bolsas para coleta de sangue necessitam cuidados técnicos que assegurem sua esterilidade biológica durante o processo de fabricação até a entrega do produto final. As bolsas para coleta de sangue não devem conter qualquer tipo de resíduo, para que o seu uso ou conteúdo não seja comprometido causando diversos transtornos. É preciso eliminar o risco de contaminação; no entanto muitas empresas fazem a inspeção de bolsas para coleta de sangue visualmente, a olho nu, por funcionários treinados no uso de equipamento simples, o qual não pode garantir que todas as bolsas estejam livres de resíduos, por depender do fator humano. Para assegurar a esterilização das bolsas comercializadas, este trabalho propõe uma metodologia para automação de um sistema de visão computacional baseado em conjunto de técnica de extração de características de imagens e reconhecimento de padrões para detectar resíduos em imagens de bolsas para coleta de sangue durante o processo de fabricação, e assim, melhorar a qualidade das bolsas comercializadas. Os resíduos encontrados nas imagens capturadas se apresentam como componentes de alta freqüência. A metodologia proposta utiliza a Transformada Wavelet (Wavelet de Haar) em dois níveis de decomposição, como filtro passa - alta para destacar as altas freqüências, e assim detectar a existência de resíduos nas imagens capturadas. Os resultados obtidos com a inspeção visual manual realizada em bolsas para coleta de sangue, mostram que existem resultados divergentes na análise de uma mesma bolsa, o que reforça a necessidade de automatização dessa tarefa para que sejam obtidos resultados mais uniformes com padrões definidos, e dessa maneira melhorar a qualidade das bolsas comercializadas para coleta de sangue. / The blood bags require technician attention to assure its biological sterility in the process of manufacture and in the final product. The blood bags must not contain any type of waste, so that its use or content is not compromised causing various disorders; it is necessary to eliminate any contamination risk; however many companies perform a visually inspection of the blood bags, by naked eye, by trained employees in the use of a simple equipment, which cannot guarantee that all the bags are residue-free because depending on the human factor. The residues showed on the pictures were characterized as high frequency components. So the proposed methodology applies two levels decomposition of Haar´s Wavelet as high pass filter to evidence high frequencies, and to evidence the residues at the pictures and to evidence the existence of residues on the captured pictures. To assure the sterilization of the commercialized blood bags, this work propose a methodology of an automated computational system based in a group of techniques of image characteristics extraction and recognition patterns to detect residues in blood bag images in the process of manufacture, in order to improve the quality of the commercialized blood bags.This technique is used as high-pass filter, to detach the high frequencies, using a Haar-wavelet in two decomposition levels. The results obtained with the manual visual inspection indicate that were found divergent results in the analysis of the same blood bag, which reinforces the necessity of the automation of this task in order to obtain more uniform results with defined standards.
26

Sensibilidade e especificidade da avaliação da postura craniocervical: fotogrametria em relação à análise de inspeção visual / Sensitivity and specificity of craniocervical posture evaluation: photogrammetry in relation to visual inspection analysis

Raquel Descie Veraldi Leite 24 March 2017 (has links)
As avaliações de postura craniocervical podem ser realizadas através de métodos qualitativos e quantitativos. Apesar das vantagens no emprego das análises quantitativas, a ausência de valores clínicos de referência para determinação da presença/ausência de desalinhamentos posturais é uma limitação para uso do recurso na prática clínica. Objetivo: Identificar os valores de acurácia, sensibilidade e especificidade da fotogrametria em relação inspeção visual para avaliação da postura craniocervical através da análise de fotografias no plano sagital, além de verificar a confiabilidade destes métodos. Método: Foram avaliadas 157 imagens no plano sagital de mulheres (35,6 DP:10,36 anos). As imagens foram analisadas através da avaliação qualitativa (inspeção visual) e através da análise quantitativa (fotogrametria) considerando-se dois ângulos: ângulo craniovertebral (ACV) e lordose cervical (ALC). Os voluntários com dor cervical também foram submetidos a avaliação de intensidade de dor e incapacidade relacionada à dor cervical. A inspeção visual foi realizada por 5 fisioterapeutas experientes. Da mesma forma a avaliação por fotogrametria foi realizada por 2 avaliadores. Todas as avaliações foram repetidas após uma semana. Para análise estatística foi utilizado o Coeficiente de Correlação Intraclasse (CCI) para analisar a confiabilidade e o Kappa de Cohen para a concordância. Além disso, os valores de acurácia, sensibilidade e especificidade foram identificados através do Receiver Operating Characteristic (ROC). Resultados: Foram observados níveis aceitáveis de confiabilidade para o ACV e ALC (CCI<0,98) por meio da fotogrametria e valores de PABAK para a concordância intra-examinador entre 0,63-0,91 (ACV) e 0,46-0,89 (ALC) e para a concordância interexaminadores de 0,51-0,85 (ACV) e 0,16-0,59 (ALC). Foi observada uma acurácia moderada (0,7 ROC<0,9) para os valores de corte do ACV (42°, EPM±0,73º) e ALC (12º-15º, EPM±0,42º) com níveis aceitáveis de sensibilidade e especificidade (<0,63). Assim, foi encontrada uma acurácia moderada (0,7<ROC<0,9) para os valores de corte dos ACV (± 42°) e ALC (± 13°) estabelecidos pelo estudo, com níveis adequados de sensibilidade e especificidade dos mesmos. Também não foram verificados níveis aceitáveis de sensibilidade, especificidade e acurácia dos ângulos de postura craniocervical para detecção dos grupos sintomático vs. assintomático para dor cervical, e para identificação dos subgrupos com e sem incapacidade relacionda a dor cervical. Conclusão: Nossos resultados dão suporte para o uso de ângulos na análise postural quantitativa que discriminam indivíduos com protrusão da cabeça moderada/severa e indivíduos com alterações da postura cervical em hiperlordose e retificação/cifose cervical em relação à postura considerada normal através da avaliação qualitativa. Entretanto, ambos os ângulos estudados não demonstraram bons índices para discriminar indivíduos sintomáticos vs. assintomáticos para dor cervical ou subgrupos com e sem incapacidade relacionda à dor cervical. / Evaluations of craniocervical posture can be performed through qualitative and quantitative methods. Although the advantages in the use of quantitative analyzes, the absence of clinical reference values to determine the presence / absence of postural misalignments is a limitation for the use of the resource in clinical practice. Objective: To identify the accuracy, sensitivity and specificity values of the photogrammetry in relation to the visual inspection to evaluate the craniocervical posture through the analysis of photographs in the sagittal plane, besides verifying the reliability of these methods. Method: 157 images were evaluated in the sagittal plane of women (35.6 SD: 10.36 years). The images were analyzed through qualitative evaluation (visual inspection) and quantitative analysis (photogrammetry) considering two angles: craniovertebral angle (CVA) and cervical lordosis (LCA). Cervical pain volunteers were also assessed for pain intensity and disability related to cervical pain. Visual inspection was performed by 5 experienced physiotherapists. Likewise, the evaluation by photogrammetry was performed by 2 evaluators. All evaluations were repeated after one week. For statistical analysis, the Intraclass Correlation Coefficient (ICC) was used to analyze reliability and Cohen\'s Kappa for agreement. In addition, the values of accuracy, sensitivity and specificity were identified through the Receiver Operating Characteristic (ROC). Results: Acceptable levels of reliability for CVA and LCA (ICC <0.98) were observed by photogrammetry and PABAK values for intra-examiner agreement between 0.63-0.91 (CVA) and 0.46- 0.89 (LCA) and for the inter-examiner agreement of 0.51-0.85 (CVA) and 0.16-0.59 (LCA). A moderate accuracy (0.7 < ROC <0.9) was observed for the cut values of the CVA (42 °, SME ± 0.73 °) and LCA (12 ° -15 °, SME ± 0.42 °) with acceptable levels of Sensitivity and specificity (<0.63). Thus, a moderate accuracy (0.7 <ROC <0.9) was found for the cutoff values of the CVA (±42°) and LCA (± 13 °) established by the study, with adequate levels of sensitivity and specificity. Also, no acceptable levels of sensitivity, specificity and accuracy of the craniocervical posture angles were detected for symptomatic groups vs. Asymptomatic for cervical pain, and to identify the subgroups with and without disability related to cervical pain. Conclusion: Our results support the use of angles in the quantitative postural analysis that discriminate individuals with moderate / severe head protrusion and individuals with altered cervical posture in hyperlordosis and rectification / cervical kyphosis in relation to the posture considered normal through the qualitative evaluation. However, both angles studied did not show good indices to discriminate symptomatic individuals vs. Asymptomatic for cervical pain or subgroups with and without disability related to cervical pain.
27

Inspecting product quality with computer vision techniques : Comparing traditional image processingmethodswith deep learning methodson small datasets in finding surface defects

Hult, Jim, Pihl, Pontus January 2021 (has links)
Quality control is an important part of any production line. It can be done manually but is most efficient if automated. Inspecting qualitycan include many different processes but this thesisisfocusedon the visual inspection for cracks and scratches. The best way of doingthis at the time of writing is with the help of Artificial Intelligence (AI), more specifically Deep Learning (DL).However, these need a training datasetbeforehand to train on and for some smaller companies, this mightnotbean option. This study triesto find an alternative visual inspection method,that does notrelyon atrained deep learning modelfor when trainingdata is severely limited. Our method is to use edge detection algorithmsin combination with a template to find any edge that doesn’t belong. These include scratches, cracks, or misaligned stickers. These anomalies arethen highlighted in the original picture to show where the defect is. Since deep learningis stateof the art ofvisual inspection, it is expected to outperform template matching when sufficiently trained.To find where this occurs,the accuracy of template matching iscompared to the accuracy of adeep learning modelat different training levels. The deep learning modelisto be trained onimage augmenteddatasets of size: 6, 12, 24, 48, 84, 126, 180, 210, 315, and 423. Both template matching and the deep learning modelwas tested on the samebalanceddataset of size 216. Half of the dataset was images of scratched units,and the other half was of unscratched units. This gave a baseline of 50% where anything under would be worse thanjust guessing. Template matching achieved an accuracy of 88%, and the deep learning modelaccuracyrose from 51% to 100%as the training setincreased. This makes template matching have better accuracy then AI trained on dataset of 84imagesor smaller. But a deep learning modeltrained on 126 images doesstart to outperform template matching. Template matching did perform well where no data was available and training adeep learning modelis no option. But unlike a deep learning model, template matching would not need retraining to find other kinds of surface defects. Template matching could also be used to find for example, misplaced stickers. Due to the use of a template, any edge that doesnot match isdetected.  The ways to train deep learning modelis highly customizable to the users need. Due to resourceand knowledge restrictions, a deep dive into this subject was not conducted.For template matching, only Canny edge detection was used whenmeasuringaccuracy. Other edge detection methodssuch as, Sobel, and Prewitt was ruledoutearlier in this study.
28

Development of an Index for Concrete Bridge Deck Management in Utah

White, Ellen T. 14 July 2006 (has links) (PDF)
The purpose of this research was to develop a new index for concrete bridge deck management in Utah. Data were collected in the summer of 2005 from 15 concrete bridge decks in the vicinity of Salt Lake City. The decks ranged from 2 to 21 years in age and were all constructed using epoxy-coated rebar. Visual inspection, sounding, Schmidt hammer testing, half-cell potential testing, and chloride concentration testing were performed on six 6-ft by 6-ft test areas randomly distributed within the single lane closed to traffic on each deck, and testing protocols followed American Society for Testing and Materials standards to the extent possible. Collected data were analyzed using statistics, and age, cover, and half-cell potential were ultimately selected for inclusion in a new Utah Bridge Deck Index (UBDI); these variables effectively reflect chloride-induced corrosion mechanisms active on Utah bridge decks, are highly correlated to delamination distresses, and are relatively easy to measure compared to chloride concentration. At the request of Utah Department of Transportation (UDOT) personnel, the UBDI equation was structured around a deduct system using a 100-point scale similar to the sufficiency rating system, in which a perfect bridge deck receives a score of 100. Coefficients were selected based largely on the judgment of the researchers and the UDOT personnel involved in the research, and threshold values for maintenance, rehabilitation, and replacement (MR&R) options were specified to be the same as those associated with the standard sufficiency ratings. The UBDI and corresponding MR&R recommendation were then provided for each of the bridge decks tested in this research; nine of the decks are recommended for preventive treatment, and six are recommended for rehabilitation. In addition, the possibility of treatment applications was considered, leading to required adjustments in the UBDI calculation; the treatment options that were considered include an epoxy seal, an HPC overlay, and an asphalt membrane overlay. Four case scenarios were developed to demonstrate the response of the revised UBDI equation to these treatments. Finally, as aids for UDOT personnel implementing this research, charts were created to facilitate rapid determination of the required number of half-cell potential and concrete cover measurements for different levels of reliability and tolerance. The UBDI developed in this research is recommended for implementation by UDOT personnel as a tool for optimizing the timing of MR&R treatments on concrete bridge decks similar to those evaluated in this project. In measuring cover and half-cell potential values, UDOT personnel should utilize the sampling guidelines presented in this report to ensure adequate characterization of each deck. Furthermore, to facilitate the inclusion of treatment effects in the UBDI, UDOT personnel should establish a policy of recording the types and dates of all MR&R treatments applied to bridge decks. As performance data are collected for specific treatments over time, the treatment lives proposed in this research for epoxy seals, HPC overlays, and asphalt membrane overlays should be revised as needed, and information for other treatments may be added. In addition, to maximize the predictive capabilities of the UBDI, more accurate relationships between half-cell potential values and deck age should be developed for estimating future deck condition.
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Condition Analysis of Concrete Bridge Decks in Utah

Tuttle, Robert S. 15 June 2005 (has links) (PDF)
Concrete bridge decks in Utah are experiencing observable deterioration due primarily to freeze-thaw cycles and the routine application of deicing salts during winter maintenance activities. Given the need for increasingly cost-effective strategies for bridge deck maintenance, rehabilitation, and replacement (MR&R), the Utah Department of Transportation (UDOT) initiated this research to ultimately develop a protocol offering guidance as to whether deteriorated bridge decks should be rehabilitated or replaced. While threshold values for various non-destructive condition assessment methods were proposed in earlier UDOT research, this work focused on implementing the recommended test criteria. Twelve bridges were identified by UDOT engineers for inclusion in the study, and data were collected from each deck to determine whether the bridge decks warranted rehabilitation or replacement based on the proposed threshold values. Several evaluation techniques were employed to assess concrete bridge deck condition, including visual inspection, hammer sounding and chaining, dielectric measurements, ground-penetrating radar imaging, resistivity testing, half-cell potential testing, and chloride concentration testing. The condition assessment testing confirmed that chloride-induced corrosion of reinforcing steel is the primary mechanism of deck deterioration and that inadequate cover over the upper steel mat facilitated accelerated corrosion damage in many instances. The bridge deck condition analyses produced from the results of non-destructive testing were compared to the visual inspection ratings assigned to each deck by UDOT. Concrete bridge deck condition data should be collected regularly through inspection and monitoring programs to facilitate prioritization of MR&R strategies for individual bridges and to evaluate the impact of such strategies on the overall condition of the network. Performance indices based on selected condition assessment parameters should be developed for use in bridge management activities, and mathematical deterioration models should be calibrated in order to forecast both network-level and project-level conditions and predict funding requirements for various possible MR&R strategies. Further research, including statistical analyses of the data presented in this report, should be completed to develop relevant mathematical deterioration models for predicting the service lives of concrete bridge decks in Utah.
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Comparison of Autofocus Methods for Highly Reflective Surfaces : A Case Study on the Inspection of Optical Filters / Jämförelse av autofokusmetoder för högreflekterande ytor

Hedvall, Axel January 2023 (has links)
Visual inspection is a crucial final step when manufacturing products, as it determines if a product can be sold or rejected. The inspection is often performed manually by trained inspectors, which is time-consuming and often subjective. By automating the inspection, it can be performed faster and more accurately. Additionally, with faster and better results from inspection, faults in production can be noticed quickly and prevented, thus saving both money and resources. The automation often involves capturing images of the productand then analysing the images with a computer program. When capturing the images, the product must be in focus and under correct lighting. This master thesis set out to compare autofocus methods in the context of capturing images of optical filters for inspection. As the optical filters were highly reflective in the visual spectrum, the comparison was limited to autofocus methods proven to work on reflective surfaces. The literature proposes four autofocus methods for reflective surfaces. These four methods were compared regarding time, resolution, and working range. As these methods were designed for microscopes with high amplification and limited working range, they were overly complex and not applicable to the context of capturing images of optical filters. Therefore a more straightforward method with a lower resolution and larger working range that uses readily available components is proposed. The proposed method is a hybrid method using light triangulation and contrast detection, two standard autofocus methods for matte surfaces. The light triangulation quickly gives a rough focus, and then the final focus can iteratively be found with contrast detection. In the tests performed, the proposed method found focus and captured an image within 12 seconds. The proposed method achieved a resolution of just over 0.1 millimetres with a working range of 200 millimetres. / Visuell inspektion är ett avgörande sista steg under tillverkning, då det avgör ifall en produkt kan säljas eller ska kasseras. Inspekitonen genomförs ofta manuellt av tränade inspektörer vilket är tidskrävande och ofta subjektivt. Genom att automatisera inspektionen kan den genomföras snabbare och mer exakt. Dessutom med snabbare och bättre resultat från inspektionen så kan fel under produktionen upptäckas tidigt och förebyggas vilket sparar både pengar och resurser. Automatiseringen genomförs ofta genom att bilder på produkten tas och analyseras med ett datorprogram. När bilderna tas så är det viktigt att produkten är i fokus och under rätt belysning.  I detta mastersarbete så jämfördes olika autofokusmetoder i samband med att ta bilder på optiska filter för inspektion. Då de optiska filtren är högreflektiva i det synliga spektrumet så begränsades metoderna i jämförelsen till metoder som har visats fungera på reflektiva ytor. Litteraturen föreslår fyra autofokusmetoder för reflektiva ytor. Dessa fyra metoder jämfördes med avseende på tid, upplösning och arbetsområde. Då dessa metoder var designade för mikroskop med hög förstoring och begränsat arbetsområde så blev det tydligt att de var alltför komplicerade och inte applicerbara i samband med att ta bilder på optiska filter. Därför föreslås en enklare metod med lägre upplösning och större arbetsområde som använder lättillgängliga komponenter.  Den föreslagna metoden är en hybridmetod som använder ljustriangulering och kontrastdetektering, två vanliga autofokusmetoder för matta ytor. Ljustrianguleringen ger snabbt ett ungefärligt fokus och därefter kan det slutliga fokuset iterativt tas fram med kontrastdetektering. I testerna som genomfördes så hittade den föreslagna metoden korrekt fokus och en bild togs inom 12 sekunder. Metoden uppnådde en upplösning på drygt 0,1 millimeter och ett arbetsområde på 200 millimeter.

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