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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.
351

Predicting Purchase of Airline Seating Using Machine Learning / Förutsägelse på köp av sätesreservation med maskininlärning.

El-Hage, Sebastian January 2020 (has links)
With the continuing surge in digitalization within the travel industry and the increased demand of personalized services, understanding customer behaviour is becoming a requirement to survive for travel agencies. The number of cases that addresses this problem are increasing and machine learning is expected to be the enabling technique. This thesis will attempt to train two different models, a multi-layer perceptron and a support vector machine, to reliably predict whether a customer will add a seat reservation with their flight booking. The models are trained on a large dataset consisting of 69 variables and over 1.1 million historical recordings of bookings dating back to 2017. The results from the trained models are satisfactory and the models are able to classify the data with an accuracy of around 70%. This shows that this type of problem is solvable with the techniques used. The results moreover suggest that further exploration of models and additional data could be of interest since this could help increase the level of performance. / Med den fortsatta ökningen av digitalisering inom reseindustrin och det faktum att kunder idag visar ett stort behov av skräddarsydda tjänster så stiger även kraven på företag att förstå sina kunders beteende för att överleva. En uppsjö av studier har gjorts där man försökt tackla problemet med att kunna förutse kundbeteende och maskininlärning har pekats ut som en möjliggörande teknik. Inom maskininlärning har det skett en stor utveckling och specifikt inom området djupinlärning. Detta har gjort att användningen av dessa teknologier för att lösa komplexa problem spritt sig till allt fler branscher. Den här studien implementerar en Multi-Layer Perceptron och en Support Vector Machine och tränar dessa på befintliga data för att tillförlitligt kunna avgöra om en kund kommer att köpa en sätesreservation eller inte till sin bokning. Datat som användes bestod av 69 variabler och över 1.1 miljoner historiska bokningar inom tidsspannet 2017 till 2020. Resultaten från studien är tillfredställande då modellerna i snitt lyckas klassificera med en noggrannhet på 70%, men inte optimala. Multi-Layer Perceptronen presterar bäst på båda mätvärdena som användes för att estimera prestandan på modellerna, accuracy och F1 score. Resultaten pekar även på att en påbyggnad av denna studie med mer data och fler klassificeringsmodeller är av intresse då detta skulle kunna leda till en högre nivå av prestanda.
352

Cost-Sensitive Learning-based Methods for Imbalanced Classification Problems with Applications

Razzaghi, Talayeh 01 January 2014 (has links)
Analysis and predictive modeling of massive datasets is an extremely significant problem that arises in many practical applications. The task of predictive modeling becomes even more challenging when data are imperfect or uncertain. The real data are frequently affected by outliers, uncertain labels, and uneven distribution of classes (imbalanced data). Such uncertainties create bias and make predictive modeling an even more difficult task. In the present work, we introduce a cost-sensitive learning method (CSL) to deal with the classification of imperfect data. Typically, most traditional approaches for classification demonstrate poor performance in an environment with imperfect data. We propose the use of CSL with Support Vector Machine, which is a well-known data mining algorithm. The results reveal that the proposed algorithm produces more accurate classifiers and is more robust with respect to imperfect data. Furthermore, we explore the best performance measures to tackle imperfect data along with addressing real problems in quality control and business analytics.
353

Evaluation of Three Machine Learning Algorithms for the Automatic Classification of EMG Patterns in Gait Disorders

Fricke, Christopher, Alizadeh, Jalal, Zakhary, Nahrin, Woost, Timo B., Bogdan, Martin, Classen, Joseph 27 March 2023 (has links)
Gait disorders are common in neurodegenerative diseases and distinguishing between seemingly similar kinematic patterns associated with different pathological entities is a challenge even for the experienced clinician. Ultimately, muscle activity underlies the generation of kinematic patterns. Therefore, one possible way to address this problem may be to differentiate gait disorders by analyzing intrinsic features of muscle activations patterns. Here, we examined whether it is possible to differentiate electromyography (EMG) gait patterns of healthy subjects and patients with different gait disorders using machine learning techniques. Nineteen healthy volunteers (9 male, 10 female, age 28.2 ± 6.2 years) and 18 patients with gait disorders (10 male, 8 female, age 66.2 ± 14.7 years) resulting from different neurological diseases walked down a hallway 10 times at a convenient pace while their muscle activity was recorded via surface EMG electrodes attached to 5 muscles of each leg (10 channels in total). Gait disorders were classified as predominantly hypokinetic (n = 12) or ataxic (n = 6) gait by two experienced raters based on video recordings. Three different classification methods (Convolutional Neural Network—CNN, Support Vector Machine—SVM, K-Nearest Neighbors—KNN) were used to automatically classify EMG patterns according to the underlying gait disorder and differentiate patients and healthy participants. Using a leave-one-out approach for training and evaluating the classifiers, the automatic classification of normal and abnormal EMG patterns during gait (2 classes: “healthy” and “patient”) was possible with a high degree of accuracy using CNN (accuracy 91.9%), but not SVM (accuracy 67.6%) or KNN (accuracy 48.7%). For classification of hypokinetic vs. ataxic vs. normal gait (3 classes) best results were again obtained for CNN (accuracy 83.8%) while SVM and KNN performed worse (accuracy SVM 51.4%, KNN 32.4%). These results suggest that machine learning methods are useful for distinguishing individuals with gait disorders from healthy controls and may help classification with respect to the underlying disorder even when classifiers are trained on comparably small cohorts. In our study, CNN achieved higher accuracy than SVM and KNN and may constitute a promising method for further investigation.
354

The Characterization and Utilization of Middle-range Sequence Patterns within the Human Genome

Shepard, Samuel Steven 20 May 2010 (has links)
No description available.
355

ON APPLICATIONS OF STATISTICAL LEARNING TO BIOPHYSICS

CAO, BAOQIANG 03 April 2007 (has links)
No description available.
356

AUTOMATED MACHINE LEARNING BASED ANALYSIS OF INTRAVASCULAR OPTICAL COHERENCE TOMOGRAPHY IMAGES

Shalev, Ronny Y. 31 May 2016 (has links)
No description available.
357

Statistical Applications of Linear Programming for Feature Selection via Regularization Methods

Yao, Yonggang 01 October 2008 (has links)
No description available.
358

Machine Learning Based Failure Detection in Data Centers

Piran Nanekaran, Negin January 2020 (has links)
This work proposes a new approach to fast detection of abnormal behaviour of cooling, IT, and power distribution systems in micro data centers based on machine learning techniques. Conventional protection of micro data centers focuses on monitoring individual parameters such as temperature at different locations and when these parameters reach certain high values, then an alarm will be triggered. This research employs machine learning techniques to extract normal and abnormal behaviour of the cooling and IT systems. Developed data acquisition system together with unsupervised learning methods quickly learns the physical dynamics of normal operation and can detect deviations from such behaviours. This provides an efficient way for not only producing health index for the micro data center, but also a rich label logging system that will be used for the supervised learning methods. The effectiveness of the proposed detection technique is evaluated on an micro data center placed at Computing Infrastructure Research Center (CIRC) in McMaster Innovation Park (MIP), McMaster University. / Thesis / Master of Science (MSc)
359

Programming with shapes / Programmering med former

Webb, Jack January 2024 (has links)
This thesis investigated how shapes can be mapped to programming constructs, offering a new way to compose and understand code with the long term goal of creating a tactile programming tool. By doing so it delved into the challenges of translating shapes into abstract programming concepts. Existing programming tools rely heavily on visual interfaces, making them inaccessible to individuals with visual impairments. Similar endeavours to create tactile programming tools were analysed and were shown to be domain-specific rather than Turing-complete which greatly limits their usefulness. The solution was to map a set of shapes to a set of Brainfuck (BF) instructions and classifying these shapes with a Support Vector Machine (SVM). Results are promising but are as of yet untested in less than ideal conditions, such as it would be in a real world application. More work has to be done to reach the goal of a tactile programming tool accessible to individuals with visual impairments. / Denna avhandling undersökte hur former kan kartläggas till programmerings-konstruktioner, vilket erbjuder ett nytt sätt att komponera och förstå kod med ett långsiktigt mål att skapa ett taktilt programmingsverktyg. Genom att göra det går den in på utmaningarna med att översätta former till abstrakta programmeringskoncept. Befintliga programmeringsverktyg förlitar sig i hög grad på visuella gränssnitt, vilket gör dem otillgängliga för personer med synnedsättningar. Liknande försök att skapa taktila programmeringsverktyg analyserades och visades vara domänspecifika snarare än Turing-kompletta, vilket starkt begränsar deras användbarhet. Lösningen var att kartlägga en uppsättning former till en uppsättning Brainfuck (BF)-instruktioner och klassificera dessa former med en Support Vector Machine (SVM). Resultaten är lovande men har ännu inte testats under mindre än ideala förhållanden, såsom det skulle vara i en verklig tillämpning. Mer arbete måste göras för att nå målet med ett taktilt programmeringsverktyg som är tillgängligt för personer med synnedsättningar.
360

Text Localization for Unmanned Ground Vehicles

Kirchhoff, Allan Richard 16 October 2014 (has links)
Unmanned ground vehicles (UGVs) are increasingly being used for civilian and military applications. Passive sensing, such as visible cameras, are being used for navigation and object detection. An additional object of interest in many environments is text. Text information can supplement the autonomy of unmanned ground vehicles. Text most often appears in the environment in the form of road signs and storefront signs. Road hazard information, unmapped route detours and traffic information are available to human drivers through road signs. Premade road maps lack these traffic details, but with text localization the vehicle could fill the information gaps. Leading text localization algorithms achieve ~60% accuracy; however, practical applications are cited to require at least 80% accuracy [49]. The goal of this thesis is to test existing text localization algorithms against challenging scenes, identify the best candidate and optimize it for scenes a UGV would encounter. Promising text localization methods were tested against a custom dataset created to best represent scenes a UGV would encounter. The dataset includes road signs and storefront signs against complex background. The methods tested were adaptive thresholding, the stroke filter and the stroke width transform. A temporal tracking proof of concept was also tested. It tracked text through a series of frames in order to reduce false positives. Best results were obtained using the stroke width transform with temporal tracking which achieved an accuracy of 79%. That level of performance approaches requirements for use in practical applications. Without temporal tracking the stroke width transform yielded an accuracy of 46%. The runtime was 8.9 seconds per image, which is 44.5 times slower than necessary for real-time object tracking. Converting the MATLAB code to C++ and running the text localization on a GPU could provide the necessary speedup. / Master of Science

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