• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 123
  • 27
  • 7
  • 6
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 205
  • 78
  • 64
  • 60
  • 44
  • 35
  • 29
  • 28
  • 28
  • 27
  • 26
  • 26
  • 24
  • 21
  • 21
  • 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.
81

Evaluation of different machine learning models for the prediction of electric or hybrid vehicle buyers and identification of the characteristics of the buyers in the EU

Chowdhury, Ziaul Islam, Bensenousi, Iskanter January 2020 (has links)
The main goal of this thesis is to evaluate different machine learning models in order to classify buyers of an electric or a hybrid vehicle and to identify the characteristics of the buyers in the European Union. Machine learning algorithms and techniques were adopted to analyze the dataset and to create models that could predict, with a certain accuracy, the customer’s willingness to buy an EV. Identification of the characteristics of the buyers were based on the identified most important features from the machine learning models and statistical analysis. The research consisted of exploratory and explanatory methods (mixed method) with quantitative and qualitative techniques. Quantitative technique was applied to convert categorical values to ordinal and nominal numeric values, to establish cause and effect relationship between the variables by using statistical analysis and to apply machine learning methods on the dataset. The quantitative results were then analyzed by using quantitative and qualitative techniques in order to identify the characteristics of the buyers. The data analytics part relied on a publicly available large dataset from the EU containing transport and mobility related data. From the experiments with logistics regression, support vector machine, random forest, gradient boosting classifier and the artificial neural network it was found that ANN is the best model to identify who won’t buy an EV and gradient boosting classifier is the best model to identify who would like to buy and EV. ML based feature importance identification methods (MDI, permutation feature importance) were used to analyze the characteristics of the buyers. The major buyer’s characteristics found in this thesis are environmental concern, knowledge on car sharing, country of residence, education, control traffic, gender, incentive, education and location of residence. Authors have recommended green marketing as the potential enablers towards a faster and larger adoption of electrical vehicles in the market as environmental impact was found as the most significant behavior of the buyer. Finally, for the future researchers, the authors have recommended fine-tuning the algorithms extensively in order to achieve better accuracy and to collect primary data based on the most important features identified in this thesis.
82

STUDY OF THE RELATIONSHIP BETWEEN Mus musculus PROTEIN SEQUENCES AND THEIR BIOLOGICAL FUNCTIONS

Seth, Pawan 08 August 2007 (has links)
No description available.
83

Investigation of a Planetary Differential for Use as a Continuously Variable Transmission

Randall, Austin B. 03 July 2012 (has links) (PDF)
With gas prices on the rise, the demand for high-mileage and low pollution vehicles has taken on an unprecedented role in our society. The production and implementation of electric and hybrid-electric vehicles has recently been a large focus of all major automobile manufacturers. Although these new vehicles have begun to solve much of the expensive fuel consumption and air pollution problems that our economy faces, the initial cost of these vehicles has proven to still be too expensive to capture a significant portion of the market. The further advancement of this technology must not only continue to focus on better fuel efficient and decreased pollution producing vehicles, but also decrease the cost of these vehicles to make them more available and enticing to the general public. Results from this research include one potential solution to reduce the cost of electric and hybrid-electric vehicles. Previous research performed in this area has led to the investigation and bench-top testing of a special type of mechanical system known as a Planetary Differential (PD). An exploration of the functionality of this system has shown that the PD can simplify expensive and complex electronic control systems for electric and hybrid-electric vehicles, thus reducing the cost to the consumer. In this study, fundamental speed, torque and power relationships for the PD were developed and tested under various loading conditions. Advantages and disadvantages of the PD, as compared to other similar mechanical systems, are identified and outlined. Recommendations for future work and implementation of the PD in electric and/or hybrid-electric vehicles are presented herein.
84

Market Design for Next Generation of Shared and Electric Transportation Systems: Modeling, Optimization, and Learning

Shao, Shiping January 2022 (has links)
No description available.
85

Design of an Integrated Battery Charging System for both Wired and Wireless Charging for Battery Electric and Hybrid Vehicles

Elshaer, Mohamed A. January 2020 (has links)
No description available.
86

An Analysis of EV Battery Key Materials Demand on the Path Towards Carbon Neutrality in Sweden

Su, Hui, Lidé, Aron January 2023 (has links)
The Swedish government has set a goal to have zero net greenhouse gas emissions by 2045 andto reduce emissions from domestic transport by at least 70% compared to 2010 levels by 2030.To achieve this, an expansion of the Swedish electric vehicle (EV) personal car fleet is needed.This scientific paper utilizes material flow analysis (MFA) to predict this expansion and thecorresponding demand for battery raw materials in Sweden, examining the growth trajectory ofthe EV market in Sweden and its implications going forward. The study concluded that themarket share of electric vehicles in Sweden will increase significantly in the next ten years,which will lead to a rise in the need for battery raw materials. Depending on possiblebreakthroughs in battery technology, these demands will vary. Given the rising demand for rawmaterials and the high environmental costs associated with mining new minerals, it is importantto underscore the importance of battery recycling as an essential component of sustainablemobility. This highlights the need to improve recycling practices.
87

Designing an EV Charger & Battery Storage Unit : Adapted to Scandinavian Residential Environments

Hörnström, Linnea, Nilsson, Fredrik January 2023 (has links)
The global automotive industry is currently experiencing a shift as the sector converts from fossil fuels to electric vehicles (EVs). However, the existing infrastructure for EV charging is facing difficulties in meeting the growingdemand in terms of accessibility and technical performance. In response, companies such as Zpark EnergySystems are actively engaged in the development of chargers to cater to the needs of the next generationchargers. As part of their efforts, Zpark has introduced a new product segment specifically tailored to thegrowing market demand, by creating a fast charger for the residential market. This thesis aims to create anexterior design for the charger and battery storage unit (BSU) suited to Scandinavian residential environments.The project has been divided into three main focus areas. The first area concerns design where primarily formtheory, material science and ergonomics have been researched. To validate the theory which established thedesign elements and features of the charger and BSU, extensive user testing was performed. The second areaconcerns adaptation in terms of how the product design will suit the intended home market. Scandinavian-architecture, -design, -colours and -climate has been studied for this area. The final focus area concerns theinteraction between users and mainly the charger. Research has been conducted to explore the integration ofuser interactive features into the design. The usability of these features has also been thoroughly examinedthrough user testing. Which has been combined with theories related to colour, human-machine interaction, andform theory in order to create a user-friendly interaction experience.The project approach has been divided into the following steps; exploration, ideation, evaluation andimplementation. For the explore phase background theory to the project was researched and methods such asbenchmarking, white space analysis, customer journey, placement analysis, and user research were conductedto gain an understanding of the market and the current pain points. For the ideation phase the goal was togenerate a large number of design concepts for both the charger and BSU. This was achieved through variousinternal ideatios methods within the team as well as external methods at workshops. To narrow down betweenthe design concepts an evaluation matrix was used which resulted in a final concept that was brought forward tothe next project phase, namely the evaluation. The evaluation phase concerned testing the final conceptsthough user testing and making technical specifications according to theory. At the end of this stage a finaldesign was achieved where all details were specified and loose ends tied together. The last phase concerningimplementation was then performed in correlation with the specified design through producing digital 3Dvisualisations and creating an animation of the final designs.The project resulted in an exterior design for the charger as well as the BSU which fulfils the aims of the projectscope. The design incorporates the features found to be necessary in the background research. Further auser-friendly design was established through various user tests investigating the integrated features and revisingthem according to the user test results. Adaptation to the home market is achieved through customisablecolours and modularity of the BSU. The design incorporates the characteristics of Scandinavian design boththrough its form elements and by the use of materials which makes the charger and BSU suit a Scandinavianresidential environment in a visually cohesive and aesthetically pleasing way. / Fordonsindustrin genomgår en omfattande förändring då branschen konverterar från fossila bränslen tillelektriska fordon (EF). Branschen står inför utmaningar de kommande åren då den befintliga infrastrukturen förelbilsladdning har svårigheter att möta den ökande efterfrågan när det gäller tillgänglighet och tekniskprestanda. Därav är företag som Zpark Energy Systems aktiva i utvecklingen av innovativa laddare för atttillgodose dessa behov hos nästa generations laddare. I linje med deras satsningar har Zpark introducerat en nyproduktkategori specifikt anpassad till den växande marknadsefterfrågan genom att skapa en snabbladdaresom är skräddarsydd för bostadsmarknaden. Detta examensarbete syftar till att skapa en exteriör design försnabbladdaren samt tillhörande batterilagringsenhet (BLE) anpassad till Skandinavisk bostadsmiljö.Projektet har delats upp i fyra huvudsakliga fokusområden. Det första området centrerar kring design där främstformteori, materialvetenskap och ergonomi har studerats. För att validera teorin som designelement ochfunktioner för laddaren och BLE har baserats på så utfördes användartester. Det andra fokusområdet i projektetavser anpassning i form av hur produktens design ska anpassas till den avsedda bostadsmiljön. Teori gällandeskandinavisk arkitektur, design, färger och klimat har studerats för att skapa en akademisk grund för dettaområde. Det sista fokusområdet för projektet rör interaktionen mellan användare och främst laddaren.Användartester har genomförts för att utforska integrationen av interaktiva funktioner i designen och dessanvändbarhet. Detta har kombinerats med teorier relaterade till färgsättning, människa-maskin-interaktion ochformteori för att skapa en användarvänlig upplevelse under laddningsprocessen.Projektets tillvägagångssätt är uppdelat i tre huvudmoment: utforskning, idégenerering, utvärdering ochimplementering. Under utforskningsfasen undersöktes bakgrundsteori för projektet och metoder sombenchmarking, white space analysis, customer journey, placeringsanalys och användarstudier användes för attfå en förståelse för marknaden och befintliga utmaningar. Under idégenereringsfasen var målet att generera ettstort antal designkoncept för både laddare och BLE. Detta uppnåddes genom olika interna och externaidégenereringsmetoder och workshops. För att välja bland designkoncepten användes en utvärderingsmatrissom resulterade i ett slutgiltigt koncept vilket sedan togs vidare till nästa projektfas. Utvärderingsfaseninnefattade utvärdering av det valda design konceptet genom användartester och tekniska specifikationer enligtteorin. Vid slutet av denna fas uppnåddes en slutlig design där alla detaljer specificerades och lösa ändar knötsihop. Den sista fasen rör implementering och utfördes i enlighet med den specificerade designen genom attproducera digitala 3D-visualiseringar och skapa en animering av de slutgiltiga designerna.Projektet resulterade i en exteriör design för laddaren och BLE:n som uppfyller projektets mål: Designeninkluderar de funktioner som identifierats som nödvändiga i bakgrundsundersökningen. När det gällerfunktionaliteten skapades en användarvänlig design genom olika användartester som utvärderade deintegrerade funktionerna vilka reviderades utifrån resultatet i testerna. Anpassning till hemmamarknaden uppnåsgenom anpassningsbara färger och modularitet för BLE. Designen innehåller kännetecknen för skandinaviskdesign både genom sina formelement och genom användningen av material vilket gör att laddare och BSUpassar i en skandinavisk bostadsmiljö på ett estetiskt tilltalande sätt med hög funktionalitet.
88

Design of a LLC Resonant Converter Module with Wide Output Voltage Range for EV Fast Charging Applications

Elezab, Ahmed January 2023 (has links)
The move toward electric vehicles (EVs) has a significant impact to reduce greenhouse gas (GHG) emissions and make transportation more eco-friendly. Fast-charging stations play a crucial role in this transition, making EVs more convenient for adoption specifically when driving in long distance. However, the challenge is to create a fast-charging system that can work with the different types of EVs and their varying power needs while still being efficient and effective. In this context, this thesis embarks on this journey by introducing an innovative solution for efficient universal fast charging, spanning both low voltage and high voltage battery systems. A novel, configurable dual secondary resonant converter is proposed, which empowers the charging module to extend its output range without imposing additional demands on the resonant tank components. This solution addresses the pressing need for a wide output voltage range in fast-charging standard in the growing EV landscape. To ensure optimal performance across a broad voltage and power range, the thesis employs an analytical model for LLC resonant converters to optimize the resonant components. This strategic component selection aims to achieve the desired output voltage and power range while minimizing conduction losses. The proposed topology and design methodology are rigorously validated through the development of a 10 kW prototype. Furthermore, the study introduces a two degrees of freedom (2DoF) control scheme for the proposed LLC resonant converter with the configurable dual secondary LLC converter topology. An analytical model is formulated to guide the selection of control parameters, ensuring coverage of the desired output voltage and power range without compromising system efficiency. The steady-state analytical model is utilized for determining optimized control parameters at each operating point within the converter's output range. To enhance the charging module's power density and efficiency, a high-frequency litz-wire transformer design methodology is introduced. The transformer's core size is optimized to achieve high power density and efficiency, while the winding configuration is chosen to minimize conduction losses. Finite Element Analysis (FEA) simulations validate transformer losses and operating temperatures. The culmination of this research is the development of a 30 kW charging module prototype. This prototype features an LLC resonant converter with a configurable dual secondary and two degrees of freedom control for output voltage control. The component ratings, estimated losses, and power board design are carefully considered to create a compact and efficient charging module. Experimental testing across a universal output voltage and power range con rms the effectiveness of the proposed solution. In summary, this thesis presents a comprehensive approach to design of a module for EV fast charging application addressing voltage range, efficiency, and component optimization, resulting in the successful development of a high-performance charging module prototype. / Thesis / Doctor of Engineering (DEng)
89

On the Topology and Control of Six-Phase Current-Source Inverter (CSI) for the Powertrain of Heavy-Duty EVs

Salem, Ahmed January 2022 (has links)
The electrification of transportation is increasingly of interest to governments around the world as a means of contributing to the achievement of climate change goals. Transportation is a significant source of greenhouse gas emissions, but it is also the backbone of the global economy and local mobility. Electrification is widely seen as a promising pathway to reducing greenhouse gas emissions from transportation while continuing to support economic growth. Multiphase machines have distinctive features that draw attention in the transportation electrification domain due to their features. Recently, powertrains based on the current-source inverter (CSI) are getting more attention to be a more reliable structure for Electric Vehicles (EVs) by replacing the dc-link capacitor with a choke inductor. This thesis combines these two technologies to develop a more reliable, compact powertrain for heavy-duty electric vehicles. First, a survey covers the recent advances in several aspects such as topology, control, and performance to evaluate the possibility and the future of exploiting them more in EV applications. The six-phase drives are extensively covered here because of their inherent structure as a dual three-phase system which eases the production process. The survey presents the different topologies used in dual three-phase drives, the modulation techniques used to operate them, the status of using multiphase drives in traction applications industrially, and the upcoming trends toward promoting this technology. New powertrain configurations for heavy-duty electric vehicles (HDEV) are proposed based on current-source inverters (CSI) and asymmetrical six-phase electric machines. Since the six-phase CSI comprises two three-phase CSIs, multiple configurations can arise based on the connection between the two CSIs. In this context, the proposed powertrain configurations are based on parallel, cascaded, and standalone six-phase CSIs. The standalone topology is based on separating the two three-phase converters by supplying each converter with a dedicated dc-dc converter. A new and straightforward method is proposed to extend the six-phase standalone CSI. The proposed technique employs the vector space decomposition (VSD) to mitigate the inverter current harmonics and extend the linear modulation region by about 8%. For motor drive applications, increasing the fundamental output component can reflect higher torque production capability for the same drive size, given that thermal limits are not exceeded. Moreover, to increase the drive's reliability, space vector modulation (SVM) techniques are developed to operate the six-phase CSI while reducing the common-mode voltage (CMV) content associated with the switching of semiconductors. The SVM techniques select the switching states associated with the minimum CMV value offline to eliminate the need for measurements. Experimental validation of the proposed algorithms is presented to operate a scaled-down six-phase PMSM fed by the proposed powertrain configuration. These proposed techniques make the CSI- based powertrain a promising solution for future HDEVs in terms of cost, performance, and reliability. / Thesis / Candidate in Philosophy
90

How to Develop the Electric Vehicle Charging Station Infrastructure in China

Greene, Briun 14 October 2015 (has links)
No description available.

Page generated in 0.017 seconds