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Evaluation of biomedical microwave sensors : Microwave sensors as muscle quality discriminators in laboratory and pilot clinical trial settingsMattsson, Viktor January 2022 (has links)
In this thesis the primary focus is on the evaluation of biomedical microwave sensor to be used in the muscle analyzer system. Lower muscle quality is one indicator that a patient can have sarcopenia. Therefore the muscle analyzer system can be a tool used in screening for sarcopenia. Sarcopenia is a progressive skeletal muscle disorder that typically affects elderly people. It is characterized by several different things, one of them is that there is an infiltration of fat into the muscle. At microwave frequencies the dielectric properties of fat are vastly different than the muscles. So, this fat infiltration creates a dielectric contrast compared to muscle without this fat infiltration that the sensors aim to detect. The muscle analyzer system is proposed to be a portable device that can be employed in clinics to assess muscle quality. The sensors are evaluated on their ability to distinguish between normal muscle tissue and muscle of lower quality. This is achieved via electromagnetic simulations, clinical trials, where the system is compared against established techniques, and phantom experiments, where artificial tissue emulating materials is used in a laboratory setting to mimick the properties of human tissues. In a initial clinical pilot study the split ring resonator sensor was used, but the results raised concerns over the penetration depth of the sensor. Therefore, three new alternative sensors were designed and evaluated via simulations. Two of the new sensors showed encouraging results, one of which has been fabricated. This sensor was used in a another clinical study.This study only had data from 4 patients, 8 measurements in total, meaning it was hard to draw any conclusions from it. The sensors used in the clinical setting as well as another were evaluated in the phantom experiments. Those experiments were exploratory because a wider frequency range was used, although some problems in the experiments were found. A secondary approach in this thesis is devoted to a data-driven approach, where a microwave sensor is simulated. The data from it is simulated and used to train a neural network to predict the dielectric properties of materials. The network predicts these properties with relatively high accuracy. However, this approach is currently limited to simulations only. Several ideas on how to improve this approach and extend it to measurements is given.
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Artificial Neural Network in Exhaust Temperature Modelling : Viability of ANN Usage in Gasoline Engine ModellingNibras, Musa, Linus, Roos January 2022 (has links)
Developing and improving upon a good empirical model for an engine can be time-consuming and costly. The goal of this thesis has been to evaluate data-driven modelling, specifically neural networks, to see how well it can handle training for some static models like the mass flow of air into the cylinder, mean effective pressure and pump mean effective pressure but also for transient modelling, specifically the exhaust gas temperature. These models are evaluated against the classical empirical models to see if neural networks are a viable modelling option. This is done with five different types of neural networks which are trained. These are the feed-forward neural network, Nonlinear autoregressive exogenous model network, layer recurrent network, long short term memory network and gated recurrent network.The inputs were determined by looking at more simple physical models but also looking at the covariance to determine the usefulness of the input. If the calculation time is small for the specific network, the neural network structure is tested and optimized by training many networks and finding the median/mean result for that specific test.The result has shown that the static models are handled very well by the most simple feed-forward network. For the exhaust temperature, both NARX and Layer recurrent network could predict and handle it well giving results very close to the empirical models and could be a viable option for transient modelling, on the other hand, Long short term memory, gated recurrent network and the feed-forward network had trouble predicting the exhaust gas temperature and returned bad results while training.
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Data-driven Strain Sensor Modelling in Mining Applications : Artificial strain sensors for material fatigue estimationRydén, Alex, Langsér, Mattias January 2021 (has links)
When boring machines are used, large loads are exerted on their structure. The load cycles cause material fatigue on the boring machine structure. If the material fatigue can be estimated in real-time, maintenance can be planned more efficiently and the effect of different types of usage can be evaluated. Because of the many advantages of knowing the material fatigue, the goal of this thesis is to develop a model to predict the strain of a boring machine structure and then derive an estimate of the material fatigue caused by the strain. To do this several approaches using machine learning techniques are evaluated. The input signals were selected using both coherence analysis and mutual information. It was found that linear models outperform the tested non-linear model structures, and that non-linear mechanical connections cause difficulties. The signals to be modelled contained high frequency components that were not present in the available input signals. The results show that given favorable sensor positions, an estimate of the material fatigue can be made with sufficient accuracy when using a noise model and noise realization to cover the non-existent high frequency components.
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Mobile systems for monitoring Parkinson's diseaseMemedi, Mevludin January 2014 (has links)
A challenge for the clinical management of Parkinson's disease (PD) is the large within- and between-patient variability in symptom profiles as well as the emergence of motor complications which represent a significant source of disability in patients. This thesis deals with the development and evaluation of methods and systems for supporting the management of PD by using repeated measures, consisting of subjective assessments of symptoms and objective assessments of motor function through fine motor tests (spirography and tapping), collected by means of a telemetry touch screen device. One aim of the thesis was to develop methods for objective quantification and analysis of the severity of motor impairments being represented in spiral drawings and tapping results. This was accomplished by first quantifying the digitized movement data with time series analysis and then using them in data-driven modelling for automating the process of assessment of symptom severity. The objective measures were then analysed with respect to subjective assessments of motor conditions. Another aim was to develop a method for providing comparable information content as clinical rating scales by combining subjective and objective measures into composite scores, using time series analysis and data driven methods. The scores represent six symptom dimensions and an overall test score for reflecting the global health condition of the patient. In addition, the thesis presents the development of a web-based system for providing a visual representation of symptoms over time allowing clinicians to remotely monitor the symptom profiles of their patients. The quality of the methods was assessed by reporting different metrics of validity, reliability and sensitivity to treatment interventions and natural PD progression over time. Results from two studies demonstrated that the methods developed for the fine motor tests had good metrics indicating that they are appropriate to quantitatively and objectively assess the severity of motor impairments of PD patients. The fine motor tests captured different symptoms; spiral drawing impairment and tapping accuracy related to dyskinesias (involuntary movements) whereas tapping speed related to bradykinesia (slowness of movements). A longitudinal data analysis indicated that the six symptom dimensions and the overall test score contained important elements of information of the clinical scales and can be used to measure effects of PD treatment interventions and disease progression. A usability evaluation of the web-based system showed that the information presented in the system was comparable to qualitative clinical observations and the system was recognized as a tool that will assist in the management of patients.
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Intelligent Energy-Savings and Process Improvement Strategies in Energy-Intensive Industries / Intelligent Energy-Savings and Process Improvement Strategies in Energy-Intensive IndustriesTeng, Sin Yong January 2020 (has links)
S tím, jak se neustále vyvíjejí nové technologie pro energeticky náročná průmyslová odvětví, stávající zařízení postupně zaostávají v efektivitě a produktivitě. Tvrdá konkurence na trhu a legislativa v oblasti životního prostředí nutí tato tradiční zařízení k ukončení provozu a k odstavení. Zlepšování procesu a projekty modernizace jsou zásadní v udržování provozních výkonů těchto zařízení. Současné přístupy pro zlepšování procesů jsou hlavně: integrace procesů, optimalizace procesů a intenzifikace procesů. Obecně se v těchto oblastech využívá matematické optimalizace, zkušeností řešitele a provozní heuristiky. Tyto přístupy slouží jako základ pro zlepšování procesů. Avšak, jejich výkon lze dále zlepšit pomocí moderní výpočtové inteligence. Účelem této práce je tudíž aplikace pokročilých technik umělé inteligence a strojového učení za účelem zlepšování procesů v energeticky náročných průmyslových procesech. V této práci je využit přístup, který řeší tento problém simulací průmyslových systémů a přispívá následujícím: (i)Aplikace techniky strojového učení, která zahrnuje jednorázové učení a neuro-evoluci pro modelování a optimalizaci jednotlivých jednotek na základě dat. (ii) Aplikace redukce dimenze (např. Analýza hlavních komponent, autoendkodér) pro vícekriteriální optimalizaci procesu s více jednotkami. (iii) Návrh nového nástroje pro analýzu problematických částí systému za účelem jejich odstranění (bottleneck tree analysis – BOTA). Bylo také navrženo rozšíření nástroje, které umožňuje řešit vícerozměrné problémy pomocí přístupu založeného na datech. (iv) Prokázání účinnosti simulací Monte-Carlo, neuronové sítě a rozhodovacích stromů pro rozhodování při integraci nové technologie procesu do stávajících procesů. (v) Porovnání techniky HTM (Hierarchical Temporal Memory) a duální optimalizace s několika prediktivními nástroji pro podporu managementu provozu v reálném čase. (vi) Implementace umělé neuronové sítě v rámci rozhraní pro konvenční procesní graf (P-graf). (vii) Zdůraznění budoucnosti umělé inteligence a procesního inženýrství v biosystémech prostřednictvím komerčně založeného paradigmatu multi-omics.
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