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Pan, Wenxin (author)Subgraph matching is a fundamental problem in various fields such as machine learning, computer vision, image processing, and bioinformatics, where detecting specific substructures within an object is often crucial. In these domains, not only structure plays an essential role, but also the feature information on nodes should be incorporated,...master thesis 2023
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YAN, Chenyang (author)This study delves into the application of coded covers in enhancing Acoustic Vector Sensor (AVS) performance for sound source localization. We initially explored the use of a coded mask inspired by ultrasound imaging. However, our analysis indicated that the coded mask primarily acts as a scaling factor without substantial benefits for direction...master thesis 2023
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ZHU, LEXI (author)Doppler ultrasound imaging of cerebral blood flow faces challenges arising from a low signal-to-noise ratio (SNR) and a wide dynamic range. Echo signals received from blood cells are significantly weaker compared to surrounding tissues, such as the skull or brain soft tissue, resulting in inhibited visualization of small blood vessels and deep...master thesis 2023
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De Carlo, Francesca (author)Ultrasound images are typically generated using the Delay-And-Sum (DAS) method, which assumes a homogeneous propagation medium. When an aberrating layer is situated between the sensor array and the imaging target, this assumption does not hold, and DAS is replaced with model-based methods. These methods are computationally expensive and require...master thesis 2023
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Li, Tianyi (author)In this work, we deal with the problem of reconstructing a complete bandlimited graph signal from partially sampled noisy measurements. For a known graph structure, some efficient centralized algorithms are proposed to partition the nodes of the graph into disjoint subsets such that sampling the graph signal from any of these subsets leads to a...master thesis 2023
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Liu, Chengen (author)The edge flow reconstruction task improves the integrity and accuracy of edge flow data by recovering corrupted or incomplete signals. This can be solved by a regularized optimization problem, and the corresponding regularizers are chosen based on prior knowledge. However, obtaining prior information is challenging in some fields. Thus, we...master thesis 2023
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Demir, Kaan (author)Existing sonar systems typically rely on a minimum signal strength of a single echo, which limits their performance in low signal-to-noise conditions. This thesis explores the concept of coherent integration for active sonar, with the aim of improving imaging and detection capabilities under low signal-to-noise conditions. The goal is to provide...master thesis 2023
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Focante, Edoardo (author)In recent years, neural networks (NNs) have seen a surge in popularity due to their ability to model complex patterns and relationships in data. One of the challenges of using NNs is the requirement for large amounts of labelled data to train the model effectively. In many real-world applications such as radar, labelled data may be scarce due to...master thesis 2023
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van Heteren, Mauries (author)The underwater acoustic environment is amongst the most challenging mediums for wireless communications. The three distinct challenges of underwater acoustic communication are the low and nonuniform propagation speed, frequency-dependent attenuation and time-varying multipath propagation.<br/>To cope with these challenges, physical layer...master thesis 2022
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van der Hoeven, Jelmer (author)In the current Big Data era, large amounts of data are collected from complex systems, such as sensor networks and social networks. The emerging field of graph signal processing (GSP) leverages a network structure (graph) to process signals on an irregular domain. This thesis studies the forecasting of multi-dimensional graph processes, i.e.,...master thesis 2022
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Garst, Swier (author)Federated learning is an upcoming machine learning concept which allows data from multiple sources be usedfor training of classifiers without said data leaving its origin. In certain research cases using highly privatedata, the step of gathering data can be quite tedious. In such cases, federated learning has the potential tovastly speed up the...master thesis 2021
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He, Yanbin (author)Graphs can be models for many real-world systems, where nodes indicate the entities and edges indicate the pairwise connections in between. In various cases, it is important to detect informative subsets of nodes such that the nodes within the subsets are ’closer’ to each other. For example, in a cellular network, determining appropriate node...master thesis 2021
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Enthoven, Maarten (author)At the Center for Ultrasound and Brain imaging at Erasmus MC in Rotterdam, a mouse's visual cortex had been imaged using the fUS technique. The mouse had been exposed to different visual stimuli. The stimuli varied in position, size, and shape. We investigate how the measured task-based fUS signals differ depending on the visual stimuli...master thesis 2021
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Gerçekcioğlu, S.A. (author)Networks with a large number of participants and a highly dynamic data exchange are better off using a distributed networking system due to network failures in centralized networks. However, with the increase in distributed networking, security problems arise in distributed processes. Injection of malicious data, for example, must be dealt with...master thesis 2021
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Dullaart, Bob (author)On land, localization or ranging is typically performed by using electromagnetic waves. In an underwater environment, this becomes difficult, as electromagnetic waves dampen out fast. As a solution often acoustic waves are used to perform localization. Because of the complexity of underwater acoustic propagation, an acoustic propagation model is...master thesis 2020
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Achten, Huib (author), Rojer, Gideon (author)In this paper we will research the possibility, reliability and accuracy of calculating the heart rate of a patient at rest using Ballistocardiography in clinical settings. The vital signs of the patient will be extracted by using piezoelectric sensor which is embedded in a Bedsense device developed by Momomedical. The device developed by...bachelor thesis 2020
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Jong, Emilie (author), Verhagen, A.R.I. (author)This report presents a bed exit prediction model using a decision tree classifier, a machine learning method. This system is designed to alarm a caregiver in a nursing home to prevent bed falls among institutionalized elderly. For the input of this algorithm, features are derived from four force sensing resistor sensors and six piezoelectric...bachelor thesis 2020
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Kerkhof, Franck (author), Rodewijk, Koen (author)In this study multiple design approaches have been tried to accurately determine the respiratory rate every 30 seconds of a patient in a hospital bed using six piezoelectric pressure sensors located sandwiched between the mattress and the bed. After four design iterations using a variety of different methods, a final design using a Least Mean...bachelor thesis 2020
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Garcia Manso, A. (author)In the oil and gas industry a crucial step for detecting and developing natural resources is to drill wells and measure miscellaneous properties along the well depth. These measurements are used to understand the rock and hydrocarbon properties and support oil/gas field development. The measurements are done at multiple times and using different...master thesis 2020
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Zhang, Kaiwen (author)In radio astronomy (RA), one of the key tasks is the estimation of the celestial source powers, i.e. imaging. To maximize the performance, it is crucial to optimize the receiver locations before the construction of a telescope array. However, although system calibration is an integral and crucial process of imaging, it has rarely been addressed...master thesis 2020