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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.
221

E-scooter Rider Detection System in Driving Environments

Kumar Apurv (11184732) 06 August 2021 (has links)
E-scooters are ubiquitous and their number keeps escalating, increasing their interactions with other vehicles on the road. E-scooter riders have an atypical behavior that varies enormously from other vulnerable road users, creating new challenges for vehicle active safety systems and automated driving functionalities. The detection of e-scooter riders by other vehicles is the first step in taking care of the risks. This research presents a novel vision-based system to differentiate between e-scooter riders and regular pedestrians and a benchmark dataset for e-scooter riders in natural environments. An efficient system pipeline built using two existing state-of-the-art convolutional neural networks (CNN), You Only Look Once (YOLOv3) and MobileNetV2, performs detection of these vulnerable e-scooter riders.<br>
222

Klasifikace obrazů pomocí genetického programování / Image Classification Using Genetic Programming

Jašíčková, Karolína January 2018 (has links)
This thesis deals with image classification based on genetic programming and coevolution. Genetic programming algorithms make generating executable structures possible, which allows us to design solutions in form of programs. Using coevolution with the fitness prediction lowers the amount of time consumed by fitness evaluation and, therefore, also the execution time. The thesis describes a theoretical background of evolutionary algorithms and, in particular, cartesian genetic programming. We also describe coevolutionary algorithms properties and especially the proposed method for the image classifier evolution using coevolution of fitness predictors, where the objective is to find a good compromise between the classification accuracy, design time and classifier complexity. A part of the thesis is implementation of the proposed method, conducting the experiments and comparison of obtained results with other methods.
223

Biometrie s využitím snímků sítnice s nízkým rozlišením / Retinal biometry with low resolution images

Smrčková, Markéta January 2020 (has links)
This thesis attempts to find an alternative method for biometric identification using retinal images. First part is focused on the introduction to biometrics, human eye anatomy and methods used for retinal biometry. The essence of neural networks and deep learning methods is described as it will be used practically. In the last part of the thesis a chosen identification algorithm and its implementation is described and the results are presented.
224

Detekce pohybujících se objektů ve videu s využitím neuronových sítí pomocí Android aplikace / Object detection in video using neural networks and Android application

Mikulec, Vojtěch January 2021 (has links)
This master’s thesis deals with the implementation of functional solution for classifying road users using mobile device with Android operating system. The goal is to create Android application which classifies vehicles in real time using rear-facing camera and saves timestamps of classification. Testing is performed mostly with own, diversely modificated dataset. Five models are trained and their performance is measured in dependence on hardware. The best classification performance is from pretrained MobileNet model where transfer learning with 6 classes of own dataset is used – 62,33 %. The results are summarized and a method for faster and more accurate traffic analysis is proposed.
225

Evaluating Robustness of a CNN Architecture introduced to the Adversarial Attacks

Ishak, Shaik, Jyothsna Chowdary, Anantaneni January 2021 (has links)
Abstract: Background: From Previous research, state-of-the-art deep neural networks have accomplished impressive results on many images classification tasks. However, adversarial attacks can easily fool these deep neural networks by adding little noise to the input images. This vulnerability causes a significant concern in deploying deep neural network-based systems in real-world security-sensitive situations. Therefore, research in attacking and the architectures with adversarial examples has drawn considerable attention. Here, we use the technique for image classification called Convolutional Neural Networks (CNN), which is known for determining favorable results in image classification. Objectives: This thesis reviews all types of adversarial attacks and CNN architectures in the present scientific literature. Experiment to build a CNN architecture to classify the handwritten digits in the MNIST dataset. And they are experimenting with adversarial attacks on the images to evaluate the accuracy fluctuations in categorizing images. This study also includes an experiment using the defensive distillation technique to improve the architecture's performance under adversarial attacks.  Methods: This thesis includes two methods; the systematic literature review method involved finding the best performing CNN architectures and best performing adversarial attack techniques. The experimentation method consists in building a CNN model based on modified LeNet architecture with two convolutional layers, one max-pooling layer, and two dropouts. The model is trained and tested with the MNIST dataset. Then applying adversarial attacks FGSM, IFGSM, MIFGSM on the input images to evaluate the model's performance. Later this model will be modified a little by defensive distillation technique and then tested towards adversarial attacks to evaluate the architecture's performance. Results: An experiment is conducted to evaluate the robustness of the CNN architecture in classifying the handwritten digits. The graphs show the accuracy before and after implementing adversarial attacks on the test dataset. The defensive distillation mechanism is applied to avoid adversarial attacks and achieve robust architecture. Conclusions: The results showed that FGSM, I-FGSM, MI-FGSM attacks reduce the test accuracy from 95% to around 35%. These three attacks to the proposed network successfully reduced ~70% of the test accuracy in all three cases for maximum epsilon 0.3. By the defensive distillation mechanism, the test accuracy reduces from 90% to 88% for max epsilon 0.3. The proposed defensive distillation process is successful in defending the adversarial attacks.
226

Použití strukturální metody pro rozpoznávání objektů / Using structural method for objects recognition

Valsa, Vít January 2015 (has links)
This diploma thesis deals with posibilities of using structural methods for recognition objects in a picture. The first part of this thesis describes methods for preparing the picture before processing. The core of the whole thesis is in chapter 3, where is analyzed in details the problem of the formation of deformation grammars for parsing and their using. In the next part is space for syntactic parser describing the deformation grammar. The conclusion is focused on testing the suggested methods and their results.
227

Segmentační metody ve zpracování biomedicínských obrazů / Segmentation Methods in Biomedical Image Processing

Mikulka, Jan January 2011 (has links)
The PhD thesis deals with modern methods of image processing, especially image segmentation, classification and evaluation of parameters. It is focused primarily on processing medical images of soft tissues obtained by magnetic resonance tomography (MR) and microscopic images of tissues. It is easy to describe edges of the sought objects using of segmented images. The edges found can be useful for further processing of monitored object such as calculating the perimeter, surface and volume evaluation or even three-dimensional shape reconstruction. The proposed solutions can be used for the classification of healthy/unhealthy tissues in MR or other imaging. Application examples of the proposed segmentation methods are shown in this thesis. Research in the area of image segmentation is focused on methods based on solving partial differential equations. This is a modern method for image processing, often called the active contour method. It is of great advantage in the segmentation of real images degraded by noise with fuzzy edges and transitions between objects. The results of the thesis are methods proposed for automatic image segmentation and classification.
228

Evaluating Response Images From Protein Quantification

Engström, Mathias, Olby, Erik January 2020 (has links)
Gyros Protein Technologies develops instruments for automated immunoassays. Fluorescent antibodies are added to samples and excited with a laser. This results in a 16-bit image where the intensity is correlated to concentration of bound antibody. Artefacts may appear on the images due to dust, fibers or other problems, which affect the quantification. This project seeks to automatically detect such artifacts by classifying the images as good or bad using Deep Convolutional Neural Networks (DCNNs). To augment the dataset a simulation approach is used and a simulation program is developed that generates images based on developed simulation models. Several classification models are tested as well as different techniques used for training. The highest performing classifier is a VGG16 DCNN, pre-trained on simulated images, which reaches 94.8% accuracy. There are many sub-classes in the bad class, and many of these are very underrepresented in both the training and test datasets. This means that not much can be said of the classification power of these sub-classes. The conclusion is therefore that until more of this rare data can be collected, focus should lie on classifying the other more common examples. Using the approaches from this project, we believe this could result in a high performing product.
229

AI-vision som tillämpning i en stålindustri : Med inriktning på objektdetektering &amp; bildklassificering

Wenger, Jakob January 2020 (has links)
I takt med att industri 4.0 sveper över dagens industrier så utvecklas tillämpningsområden inom artificiell intelligens (AI). En relativt nyfunnen tillämpning som vanligen benämns AI-vision eller Computer-vision, inom detta arbete har benämningen AI-vision valts. Tillämpningen handlar om att datorer och maskiner upprättas med förmågan att tolka visuellt innehåll.I och med detta tränas en intelligent modell som klarar av att fatta beslut utifrån visuell data, såsom bild och video. Inriktningen i arbetet belyser inom AI-Vision teknikerna objektdetektering och bildklassificering. Objektdetektering innebär att ett eller flera specifika objekt upptäcks från en bild av flera komplexa linjer och former. Tekniken används inom en rad olika tillämpningar såsom t.ex. robotnavigering och automatisk fordonsstyrning. Syftet med bildklassificering ibland kallat bildigenkänning, handlar om att klassificera och kategorisera bilden genom att identifiera och sortera väsentlig data. Detta i försök att konstatera vad bilden i sig föreställer. För att forma och rama in detta arbete på ett lämpligt sätt ämnas huvudsakliga målet med arbetet beskriva hur tekniker såsom objektdetektering och bildklassificerings-modeller konstrueras. Så även redogöra kring bakomliggande intelligens i modellerna, samt vilka verktyg och metoder som används för att skapa dessa modeller. Arbetet syftar även till att presentera presumtiva tillämpningar inom en stålindustri, därför kommer förslag till applikationer framföras. I resultatdelen av arbetet presenteras i huvudsak uppbyggnaden av en objekdetekteringsapplikation som hanterar personsäkerhet och i diskussionsdelen framhävs vidare förslag till applikationer. Detta avses lägga grund för eventuell implementation i verkliga produktionsutrustningar i framtiden. / As Industry 4.0 sweeps across today's industries, applications within artificial intelligence (AI) are developing. A relatively new application that is commonly called AI-vision or sometimes Computer-vision, in this study the term AI-vision is used. The application is about making computers and machines visually inclined. With this, an intelligent model is trained that can make decisions based on visual data, such as image and video. The orientation in this study within AI-Vision, is to highlight object detection and image classification. Object detection defines as follows, one or more specific objects are detected from an image of several complex lines and shapes. The technology is used in a variety of applications such as robot navigation and automatic vehicle control. The purpose of image classification, sometimes called image recognition, is to classify and categorize the image by identifying and sorting essential data. This in attempt to ascertain what the image itself represents. In order to frame this work in an appropriate way, the main quest of this thesis is to describe how techniques such as Object Detection and Image Classification models are constructed. Explain the underlying intelligence in the models as well as what tools and methods are used to create these models. As the thesis also alludes to present prospective applications in a steel industry, proposals of specific applications will be presented. The results section mainly presents an Object Detection application that handles personal safety and drafts to applications is presented in the discussion section. This work intends to contribute for possible implementation in production equipment in the future.
230

Continual Learning and Biomedical Image Data : Attempting to sequentially learn medical imaging datasets using continual learning approaches / Kontinuerligt lärande och Biomedicinsk bilddata : Försöker att sekventiellt lära sig medicinska bilddata genom att använda metoder för kontinuerligt lärande

Soselia, Davit January 2022 (has links)
While deep learning has proved to be useful in a large variety of tasks, a limitation remains of needing all classes and samples to be present at the training stage in supervised problems. This is a major issue in the field of biomedical imaging since keeping samples in the training sets consistently is often a liability. Furthermore, this issue prevents the simple updating of older models with only the new data when it is introduced, and prevents collaboration between companies. In this work, we examine an array of Continual Learning approaches to try to improve upon the baseline of the naive finetuning approach when retraining on new tasks, and achieve accuracy levels similar to the ones seen when all the data is available at the same time. Continual learning approaches with which we attempt to mitigate the problem are EWC, UCB, EWC Online, SI, MAS, CN-DPM. We explore some complex scenarios with varied classes being included in the tasks, as well as close to ideal scenarios where the sample size is balanced among the tasks. Overall, we focus on X-ray images, since they encompass a large variety of diseases, with new diseases requiring retraining. In the preferred setting, where classes are relatively balanced, we get an accuracy of 63.30 versus a baseline of 53.92 and the target score of 66.83. For the continued training on the same classes, we get an accuracy of 35.52 versus a baseline of 27.73. We also examine whether learning rate adjustments at task level improve accuracy, with some improvements for EWC Online. The preliminary results indicate that CL approaches such as EWC Online and SI could be integrated into radiography data learning pipelines to reduce catastrophic forgetting in situations where some level of sequential training ability justifies the significant computational overhead. / Även om djupinlärning har visat sig vara användbart i en mängd olika uppgifter, kvarstår en begränsning av att behöva alla klasser och prover som finns på utbildningsstadiet i övervakade problem. Detta är en viktig fråga inom området biomedicinsk avbildning eftersom det ofta är en belastning att hålla prover i träningsuppsättningarna. Dessutom förhindrar det här problemet enkel uppdatering av äldre modeller med endast nya data när de introduceras och förhindrar samarbete mellan företag. I det här arbetet undersöker vi en rad kontinuerliga inlärningsmetoder för att försöka förbättra baslinjen för den naiva finjusteringsmetoden vid omskolning på nya uppgifter och närma sig noggrannhetsnivåer som de som ses när alla data är tillgängliga samtidigt. Kontinuerliga inlärningsmetoder som vi försöker mildra problemet med inkluderar bland annat EWC, UCB, EWC Online, SI. Vi utforskar några komplexa scenarier med olika klasser som ingår i uppgifterna, samt nära idealiska scenarier där exempelstorleken balanseras mellan uppgifterna. Sammantaget fokuserar vi på röntgenbilder, eftersom de omfattar ett stort antal sjukdomar, med nya sjukdomar som kräver omskolning. I den föredragna inställningen får vi en noggrannhet på 63,30 jämfört med en baslinje på 53,92 och målpoängen på 66,83. Medan vi för den utökade träningen på samma klasser får en noggrannhet på 35,52 jämfört med en baslinje på 27,73. Vi undersöker också om justeringar av inlärningsfrekvensen på uppgiftsnivå förbättrar noggrannheten, med vissa förbättringar för EWC Online. De preliminära resultaten tyder på att CL-metoder som EWC Online och SI kan integreras i rörledningar för röntgendatainlärning för att minska katastrofal glömska i situationer där en viss nivå av sekventiell utbildningsförmåga motiverar den betydande beräkningskostnaden.

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