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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.
581

Smartphone sensors are sufficient to measure smoothness of car driving / Smartphonesensorer är tillräckliga för att mäta mjukhet i bilkörning

Bränn, Jesper January 2017 (has links)
This study aims to look at whether or not it is sufficient to only use smartphone sensors to judge if someone who is driving a car is driving aggressively or smoothly. To determine this, data were first collected from the accelerometer, gyroscope, magnetometer and GPS sensors in the smartphone as well as values based on these sensors from the iOS operating system. After this the data, together with synthesized data based on the collected data, were used to train an artificial neural network.The results indicate that it is possible to give a binary judgment on aggressive or smooth driving with a 97% accuracy, with little model overfitting. The conclusion of this study is that it is sufficient to only use smartphone sensors to make a judgment on the drive. / Den här studien ämnar till att bedöma huruvida smartphonesensorer är tillräckliga för att avgöra om någon kör en bil aggressivt eller mjukt. För att kunna avgöra detta så samlades först data in från accelerometer, gyroskop, magnetometer och GPS-sensorerna i en smartphone, tillsammans med värden baserade på dessa data från iOS-operativ-systemet. Efter den datan var insamlad tränades ett artificiellt neuronnät med datan.Resultaten indikerar att det är möjligt att ge ett binärt utlåtande om aggressiv kontra mjuk körning med 97% säkerhet, och med liten överanpassning. Detta innebär att det är tillräckligt att enbart använda smartphonesensorer för att avgörande om körningen var mjuk eller aggressiv.
582

Inclusive Multiple Model Using Hybrid Artificial Neural Networks for Predicting Evaporation

Ehteram, Mohammad, Panahi, Fatemeh, Ahmed, Ali Najah, Mosavi, Amir H., El-Shafie, Ahmed 20 March 2024 (has links)
Predicting evaporation is essential for managing water resources in basins. Improvement of the prediction accuracy is essential to identify adequate inputs on evaporation. In this study, artificial neural network (ANN) is coupled with several evolutionary algorithms, i.e., capuchin search algorithm (CSA), firefly algorithm (FFA), sine cosine algorithm (SCA), and genetic algorithm (GA) for robust training to predict daily evaporation of seven synoptic stations with different climates. The inclusive multiple model (IMM) is then used to predict evaporation based on established hybrid ANN models. The adjusting model parameters of the current study is a major challenge. Also, another challenge is the selection of the best inputs to the models. The IMM model had significantly improved the root mean square error (RMSE) and Nash Sutcliffe efficiency (NSE) values of all the proposed models. The results for all stations indicated that the IMM model and ANN-CSA could outperform other models. The RMSE of the IMM was 18, 21, 22, 30, and 43% lower than those of the ANNCSA, ANN-SCA, ANN-FFA, ANN-GA, and ANN models in the Sharekord station. The MAE of the IMM was 0.112 mm/day, while it was 0.189 mm/day, 0.267 mm/day, 0.267 mm/day, 0.389 mm/day, 0.456 mm/day, and 0.512 mm/day for the ANN-CSA, ANN-SCA, and ANN-FFA, ANN-GA, and ANN models, respectively, in the Tehran station. The current study proved that the inclusive multiple models based on improved ANN models considering the fuzzy reasoning had the high ability to predict evaporation.
583

Modélisation, simulation et analyse des dynamiques spatiales des zones humides urbaines par automate cellulaire : une étude de cas à la ville de Bogota, Colombie

Cuellar Roncancio, Yenny Andrea 08 1900 (has links)
Les zones humides sont écosystèmes reconnus de vitale importance pour la conservation de la biodiversité et pour un développement soutenable. En Colombie, 26 % du territoire continental national est couvert de ces écosystèmes. Le complexe de zones humides urbaines de Bogota, en fait partie, avec 15 écosystèmes, dont la Convention Ramsar reconnaît 11. Ils sont uniques et jouent un rôle important dans l’approvisionnement des services écosystèmes à la zone urbaine. Cependant, ces écosystèmes urbains font face à de nombreux défis en raison de leur emplacement. Les causes et les conséquences de leur transformation sont très complexes. En appliquant des approches des systèmes complexes, sa dynamique de changement peut être étudiée. Les automates cellulaires sont l’une des techniques largement utilisées dans la modélisation de la dynamique spatiotemporelle des changements de l’usage et de l’occupation des sols. Cette étude propose l’analyse et la simulation des zones humides urbaines en appliquant une approche hybride par un modèle couplé de chaîne de Markov, de réseaux de neurones artificiels et d’automates cellulaires, afin d’estimer leurs changements d’étendue pour les années 2016, 2022, 2028 et 2034 dans la ville de Bogota, en Colombie. Pour extraire le changement d’occupation et d’utilisation du sol, trois images analogues des années 1998, 2004 et 2010 ont été a utilisées. Les résultats ont montré une diminution de 0,30 % de la couverture des zones humides en douze ans. De plus, les résultats suggèrent que la couverture des zones humides représentera 1,97 % de la zone d’étude totale en 2034, représentant une probabilité de diminution de 14 % en 24 ans. D’ailleurs, en appliquant l’analyse d’intensité, il a été constaté que le gain de cultures et de pâturages cible la perte de zones humides. Bien dont ces écosystèmes soient protégés et d’utilisation restreinte, leur patron de réduction se poursuivra en 2034. La pertinence de ce projet réside dans sa contribution potentielle au processus décisionnel au sein de la ville et en tant qu’instrument de gestion des ressources naturelles. En outre, les résultats de cette étude pourraient aider à atteindre l’objectif de développement durable 6 « Eau propre et assainissement » et l’atténuation du changement climatique. / Wetlands are ecosystems recognized as being of vital importance for the conservation of biodiversity and for sustainable development. In Colombia, 26% of the national continental territory is covered by these ecosystems. The complex of urban wetlands of Bogota is one of them, with 15 ecosystems, of which the Ramsar Convention recognizes 11. They are unique and play an important role in providing ecosystem services to the urban area. However, these urban ecosystems face many challenges due to their location. The causes and consequences of their transformation are very complex. By applying complex systems approaches, the dynamics of change can be studied. Cellular automata is one of the widely used techniques in modeling the spatiotemporal dynamics of land use and land cover changes. This study proposes the analysis and simulation of urban wetlands by applying a hybrid approach through a coupled model of the Markov chain, artificial neural networks, and cellular automata, in order to estimate the extent of changes for the years 2016, 2022, 2028, and 2034 in the city of Bogota, Colombia. To extract the change in land cover and land use, three analogous images from the years 1998, 2004, and 2010 were used. The results showed a 0.30% decrease in wetland coverage in twelve years. Furthermore, the results suggest that wetland cover will be 1.97% of the total study area in 2034, representing a 14% probability of a decrease in 24 years. Moreover, by applying the intensity analysis, it was found that the gain of crop and pastureland targets the loss of wetlands. Although these ecosystems are protected and of limited use, their pattern of reduction will continue in 2034. The relevance of this project lies in its potential contribution to decision-making within the city and as a natural resource management tool. In addition, the results of this study could help achieve Sustainable Development Goal 6 “Clean Water and Sanitation” and climate change mitigation.
584

Modeling and simulation of vehicle emissions for the reduction of road traffic pollution

Rahimi, Mostafa 03 February 2023 (has links)
The transportation sector is responsible for the majority of airborne particles and global energy consumption in urban areas. Its role in generating air pollution in urban areas is even more critical, as many visitors, commuters and citizens travel there daily for various reasons. Emissions released by transport fleets have an exhaust (tailpipe) and a non-exhaust (brake wears ) origin. Both exhaust and non-exhaust airborne particles can have destructive effects on the human cardiovascular and respiratory systems and even lead to premature deaths. This dissertation aims to estimate the amount of exhaust and brake emissions in a real case study by proposing an innovative methodology. For this purpose, different levels of study have been introduced, including the subsystem level, the system level, the environmental level and the suprasystem level. To address these levels, two approaches were proposed along with a data collection process. First, a comprehensive field survey was conducted in the area of Buonconsiglio Castle and data was collected on traffic and non-traffic during peak hours. Then, in the first approach, a state-of-the-art simulation-based method was presented to estimate the amount of exhaust emissions generated and the rate of fuel consumption in the case study using the VISSIM traffic microsimulation software and Enviver emission modeler at the suprasystem level. In order to calculate the results under different mobility conditions, a total of 18 scenarios were defined based on changes in vehicle speeds and the share of heavy vehicles (HV%) in the modal split. Subsequently, the scenarios were accurately modelled in the simulation software VISSIM and repeated 30 times with a simulation runtime of three hours. The results of the first approach confirmed the simultaneous effects of considering vehicle speed and HV % on fuel consumption and the amount of exhaust emissions generated. Furthermore, the sensitivity of exhaust emissions and fuel consumption to variations in vehicle speed was found to be much higher than HV %. In other words, the production of NOx and VOC emissions can be increased by up to 20 % by increasing the maximum speed of vehicles by 10 km/h. Conversely, increasing the HV percentage at the same speed does not seem to produce a significant change. Furthermore, increasing the speed from 30 km/h to 50 km/h increased CO emissions and fuel consumption by up to 33%. Similarly, a reduction in speed of 20 or 10 km/h with a 100% increase in HV resulted in a 40% and 27% decrease in exhaust emissions per seat, respectively. In the second approach, a novel methodology was proposed to estimate the number of brake particles in the case study. To achieve this goal, a downstream approach was proposed starting from the suprasystem level (microscopic traffic simulation models in VISSIM) and using a developed mathematical vehicle dynamics model at the system level to calculate the braking torques and angular velocities of the front and rear wheels, and proposes an artificial neural network (ANN) as a brake emission model, which has been appropriately trained and validated using emission data collected through more than 1000 experimental tribological tests on a reduced-scale dynamometer at the subsystem level (braking system). Consideration of this multi-level approach, from tribological to traffic-related aspects, is necessary for a realistic estimation of brake emissions. The proposed method was implemented on a targeted vehicle, a dominant SUV family car in the case study, considering real driving conditions. The relevant dynamic quantities of the targeted vehicle (braking torques and angular velocities of the wheels) were calculated based on the vehicle trajectory data such as speed and deceleration obtained from the traffic microsimulation models and converted into braking emissions via the artificial neural network. The total number of brake emissions emitted by the targeted vehicles was predicted for 10 iterations route by route and for the entire traffic network. The results showed that a large number of brake particles (in the order of billions of particles) are released by the targeted vehicles, which significantly affect the air quality in the case study. The results of this dissertation provide important information for policy makers to gain better insight into the rate of exhaust and brake emissions and fuel consumption in metropolitan areas and to understand their acute negative impacts on the health of citizens and commuters.
585

Learning to Price Apartments in Swedish Cities / Lära sig prissätta lägenheter i svenska städer

Segerhammar, Fredrik January 2021 (has links)
This thesis tackles the problem of accurately pricing apartments in large Swedish cities using geospatial data. The aim is to determine if geospatial data and population statistics can be used in conjunction with direct apartment data to accurately price apartments in large cities. There has previously been little research in this domain due to a lack of available data in many countries. In Sweden, apartment transaction data is public which enabled this thesis to be performed. We apply and compare a multiple linear regression, a multi-layer perceptron and a random forest to appraise apartments in six of the largest cities in Sweden. To perform the appraisals, geospatial data and population statistics were gathered in the areas surrounding the apartments. Five of the six cities were used to train and test the models, whereas one city was only used for testing. The two best performing models, the multi-layer perceptron and random forest achieved a mean absolute percentage error of 8.68% and 8.76% respectively within cities they were previously trained within and a mean absolute percentage error of 22.62% and 20.6% respectively on apartment in the test city dataset. In conclusion this thesis suggests that with the use of this data, multi-layer perceptrons and random forests are useful for appraising apartments in different cities, however that more data is probably needed to appraise apartments in cities previously unseen by the models. / Detta masterarbete tar upp problemet med att korrekt prissätta lägenheter i stora svenska städer med hjälp av geospatiala data. Syftet är att avgöra om geospatiala data och befolkningsstatistik kan användas tillsammans med direkt lägenhetsdata för att korrekt prissätta lägenheter i storstäder. Det har tidigare utförts lite forskning inom detta område på grund av brist på tillgängliga data i många länder. I Sverige är uppgifter om lägenhetstransaktioner offentliga vilket gjorde att denna avhandling kunde utföras. Vi tillämpar och jämför en multipel linjär regression, en flerskiktsperceptron och en slumpmässig skog för att värdera lägenheter i sex av de största städerna i Sverige. För att göra värderingarna samlades geospatiala data och befolkningsstatistik i de områden som omger lägenheterna. Fem av de sex städerna användes för att träna och testa modellerna, medan en stad endast användes för testning. De två bäst presterande modellerna, flerskiktsperceptronen och slumpmässig skog uppnådde ett genomsnittligt absolut procentfel på 8,68% respektive 8,76% inom städer som de tidigare var tränade inom och ett genomsnittligt absolut procentfel på 22,62% respektive 20,6% på lägenheter i teststadens dataset. Sammanfattningsvis tyder detta verk på att med hjälp av dessa data är flerskiktsperceptroner och slumpmässiga skogar användbara för att värdera lägenheter i olika städer, men att mer data förmodligen behövs för att värdera lägenheter i städer som modellerna tidigare inte har tränats på.
586

Flood Prediction System Using IoT and Artificial Neural Networks with Edge Computing

Samikwa, Eric January 2020 (has links)
Flood disasters affect millions of people across the world by causing severe loss of life and colossal damage to property. Internet of things (IoT) has been applied in areas such as flood prediction, flood monitoring, flood detection, etc. Although IoT technologies cannot stop the occurrence of flood disasters, they are exceptionally valuable apparatus for conveyance of catastrophe readiness and counteractive action data. Advances have been made in flood prediction using artificial neural networks (ANN). Despite the various advancements in flood prediction systems through the use of ANN, there has been less focus on the utilisation of edge computing for improved efficiency and reliability of such systems. In this thesis, a system for short-term flood prediction that uses IoT and ANN, where the prediction computation is carried out on a low power edge device is proposed. The system monitors real-time rainfall and water level sensor data and predicts ahead of time flood water levels using long short-term memory. The system can be deployed on battery power as it uses low power IoT devices and communication technology. The results of evaluating a prototype of the system indicate a good performance in terms of flood prediction accuracy and response time. The application of ANN with edge computing will help improve the efficiency of real-time flood early warning systems by bringing the prediction computation close to where data is collected. / Översvämningar drabbar miljontals människor över hela världen genom att orsaka dödsfall och förstöra egendom. Sakernas Internet (IoT) har använts i områden som översvämnings förutsägelse, översvämnings övervakning, översvämning upptäckt, etc. Även om IoT-teknologier inte kan stoppa förekomsten av översvämningar, så är de mycket användbara när det kommer till transport av katastrofberedskap och motverkande handlingsdata. Utveckling har skett när det kommer till att förutspå översvämningar med hjälp av artificiella neuronnät (ANN). Trots de olika framstegen inom system för att förutspå översvämningar genom ANN, så har det varit mindre fokus på användningen av edge computing vilket skulle kunna förbättra effektivitet och tillförlitlighet. I detta examensarbete föreslås ett system för kortsiktig översvämningsförutsägelse genom IoT och ANN, där gissningsberäkningen utförs över en låg effekt edge enhet. Systemet övervakar sensordata från regn och vattennivå i realtid och förutspår översvämningsvattennivåer i förtid genom att använda långt korttidsminne. Systemet kan köras på batteri eftersom det använder låg effekt IoT-enheter och kommunikationsteknik. Resultaten från en utvärdering av en prototyp av systemet indikerar en bra prestanda när det kommer till noggrannhet att förutspå översvämningar och responstid. Användningen av ANN med edge computing kommer att förbättra effektiviteten av tidiga varningssystem för översvämningar i realtid genom att ta gissningsberäkningen närmare till där datan samlas.
587

Distinguishing Behavior from Highly Variable Neural Recordings Using Machine Learning

Sasse, Jonathan Patrick 04 June 2018 (has links)
No description available.
588

Application of Data Mining and Big Data Analytics in the Construction Industry

Abounia Omran, Behzad January 2016 (has links)
No description available.
589

Long-term forecasting model for future electricity consumption in French non-interconnected territories

CARON, MATHIEU January 2021 (has links)
In the context of decarbonizing the electricity generation of French non-interconnected territories, the knowledge of future electricity demand, in particular annual and peak demand in the long-term, is crucial to design new renewable energy infrastructures. So far, these territories, mainly islands located in the Pacific and Indian ocean, relies mainly on fossil fuels powered facilities. Energy policies envision to widely develop renewable energies to move towards a low-carbon electricity mix by 2028.  This thesis focuses on the long-term forecasting of hourly electricity demand. A methodology is developed to design and select a model able to fit accurately historical data and to forecast future demand in these particular territories. Historical data are first analyzed through a clustering analysis to identify trends and patterns, based on a k-means clustering algorithm. Specific calendar inputs are then designed to consider these first observations. External inputs, such as weather data, economic and demographic variables, are also included.  Forecasting algorithms are selected based on the literature and they are than tested and compared on different input datasets. These input datasets, besides the calendar and external variables mentioned, include different number of lagged values, from zero to three. The combination of model and input dataset which gives the most accurate results on the testing set is selected to forecast future electricity demand. The inclusion of lagged values leads to considerable improvements in accuracy. Although gradient boosting regression features the lowest errors, it is not able to detect peaks of electricity demand correctly. On the contrary, artificial neural network (ANN) demonstrates a great ability to fit historical data and demonstrates a good accuracy on the testing set, as well as for peak demand prediction. Generalized additive model, a relatively new model in the energy forecasting field, gives promising results as its performances are close to the one of ANN and represent an interesting model for future research.  Based on the future values of inputs, the electricity demand in 2028 in Réunion was forecasted using ANN. The electricity demand is expected to reach more than 2.3 GWh and the peak demand about 485 MW. This represents a growth of 12.7% and 14.6% respectively compared to 2019 levels. / I samband med utfasningen av fossila källor för elproduktion i franska icke-sammankopplade territorier är kunskapen om framtida elbehov, särskilt årlig förbrukning och topplast på lång sikt, avgörande för att utforma ny infrastruktur för förnybar energi. Hittills är dessa territorier, främst öar som ligger i Stilla havet och Indiska oceanen, beroende av anläggningar med fossila bränslen. Energipolitiken planerar att på bred front utveckla förnybar energi för att gå mot en koldioxidsnål elmix till 2028.  Denna avhandling fokuserar på den långsiktiga prognosen för elbehov per timme. En metod är utvecklad för att utforma och välja en modell som kan passa korrekt historisk data och för att förutsäga framtida efterfrågan inom dessa specifika områden. Historiska data analyseras först genom en klusteranalys för att identifiera trender och mönster, baserat på en k-means klusteralgoritm. Specifika kalenderinmatningar utformas sedan för att beakta dessa första observationer. Externa inmatningar, såsom väderdata, ekonomiska och demografiska variabler, ingår också.  Prognosalgoritmer väljs utifrån litteraturen och de testas och jämförs på olika inmatade dataset. Dessa inmatade dataset, förutom den nämnda kalenderdatan och externa variabler, innehåller olika antal fördröjda värden, från noll till tre. Kombinationen av modell och inmatat dataset som ger de mest exakta resultaten på testdvärdena väljs för att förutsäga framtida elbehov. Införandet av fördröjda värden leder till betydande förbättringar i exakthet. Även om gradientförstärkande regression har de lägsta felen kan den inte upptäcka toppar av elbehov korrekt. Tvärtom, visar artificiella neurala nätverk (ANN) en stor förmåga att passa historiska data och visar en god noggrannhet på testuppsättningen, liksom för förutsägelse av toppefterfrågan. En generaliserad tillsatsmodell, en relativt ny modell inom energiprognosfältet, ger lovande resultat eftersom dess prestanda ligger nära den för ANN och representerar en intressant modell för framtida forskning.  Baserat på de framtida värdena på indata, prognostiserades elbehovet 2028 i Réunion med ANN. Elbehovet förväntas nå mer än 2,3 GWh och toppbehovet cirka 485 MW. Detta motsvarar en tillväxt på 12,7% respektive 14,6% jämfört med 2019 års nivåer.
590

<b>Development of Innovative Hardwood Products</b>

Jue Mo (18416235) 22 April 2024 (has links)
<p dir="ltr">In response to the growing significance of wood as a sustainable resource and the challenges within the wood products industry, there is a pressing need for innovation and collaboration across sectors. This study underscores the importance of mapping the wood products industry to gain a comprehensive understanding of material flows, which is essential for educational and research endeavors. The findings aim to uncover new economic opportunities and advocate for sustainable resource management. To address the complexities of the wood products industry, we developed a Generic Map, including a version tailored for the U.S. hardwood sector. Moreover, Dive-in Chain Maps were introduced to elaborate on the main production chains: Sawmill (I), Veneer Mill (II), Reconstituted Wood Manufacturing (III), and Pulp and Paper Mill (IV).</p><p dir="ltr">The study suggests four strategies to augment the value of hardwood through production, design, material modification, and by-products management. We showcased some strategies through two case studies.</p><p dir="ltr">The first focuses on Cross-laminated Timber (CLT), demonstrating value addition to hardwood. We conducted a literature review on the availability of raw materials in the US region and evaluated their performance across various stages of laboratory testing. This was followed by evaluating the feasibility and environmental effects of utilizing yellow poplar for CLT production. Additionally, we compared the Life Cycle Analysis (LCA) outcomes of yellow poplar CLT with those of traditional softwood CLT. This comparison aims to provide further insights for developing future by-product management or end-of-life strategies.</p><p dir="ltr">The second case study examines thermal modification, proposing an innovative method for efficient thermal treatment and employing an Artificial Neural Network (ANN) model to analyze the correlation between temperature, duration, and color change. We also compared the physical and mechanical properties of surface thermally treated samples to those of traditionally treated ones, discussing how different thermal treatments affect material properties.</p><p dir="ltr">Our findings illuminate the path for effective material flow and utilization, unveiling avenues for innovation and the creation of high-value products. Furthermore, the study provides strategies for waste minimization and informed end-of-life decision-making, thereby enhancing circularity and sustainability in the wood products industry.</p>

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