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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.
291

Energy consumption and GHG emissions evaluation of conventional and battery-electric refuse collection trucks

Derakhshan, Rojin 09 December 2019 (has links)
The notorious fuel consumption and environmental impact of conventional diesel refuse collection trucks (D-RCTs) encourage collection fleets to adopt alternative technologies with higher efficiency and lower emissions/noise impacts into their fleets. Due to the nature of refuse trucks’ duty cycles with low driving speeds, frequent braking and high idling time, a battery-electric refuse collection truck (BE-RCT) seems a promising alternative, taking advantage of energy-saving potentials along with zero tailpipe emissions. However, whether or not this newly-introduced technology can be commercially feasible for a collection fleet and/or additionally mitigate GHG emissions should be examined over its lifetime explicitly for the specific fleet. This study evaluates the performance of a D-RCT and BE-RCT in a collection fleet to assess the potential of BE-RCT in reducing diesel fuel consumption and the total GHG emissions. A refuse truck duty cycle (RTDC) was generated representing the driving nature and vocational operation of the refuse truck, including the speed, mass, and hydraulic cycles along with the extracted route grade profile. As a case study, the in-use data of a collection fleet, operating in the municipality of Saanich, British Columbia (BC), Canada, are applied to develop the representative duty cycle. Using the ADVISOR simulator, the D-RCT and BE-RCT are modeled and energy consumption of the trucks are estimated over the representative duty cycle. Fuel-based Well-to-Wheel (WTW) GHG emissions of the trucks are estimated considering the fuel (diesel/electricity) upstream and downstream GHG emissions over the 100-year horizon impact factor for greenhouse gases. The results showed that the BE-RCT reduces energy use by 77.7% and WTW GHG emissions by 98% compared to the D-RCT, taking advantage of the clean grid power in BC. Also, it was indicated that minimum battery capacity of 220 kWh is required for the BE-RCT to meet the duty cycle requirements for the examined fleet. A sensitivity analysis has been done to investigate the impact of key parameters on energy use and corresponding GHG emissions of the trucks. Further, the lifetime total cost of ownership (TCO) for both trucks was estimated to assess the financial competitiveness of the BE-RCT over the D-RCT. The TCO indicated that the BE-RCT deployment is not financially viable for the examined fleet unless there are considerable incentives towards the purchase cost of the BE-RCT and/or sufficient increase in carbon tax/diesel fuel price. From the energy useevaluation, this study estimates the required battery capacity of the BE-RCT for the studied fleet, and the TCO outputs can assist them in future planning for the adoption of battery-electric refuse trucks into their collection fleet where the cost parameters evolve. / Graduate
292

Deliktní odpovědnost člena statutárního orgánu obchodní korporace vůči třetím osobám / Tortious Liability of a Member of a Statutory Body of a Business Corporation Towards Third Parties

Flídr, Jan January 2020 (has links)
The dissertation addresses liability borne by members of statutory bodies (directors) for damage caused to third parties (parties not involved in the relevant corporation) where the director commits a tort in discharge of his/her tasks for the corporation, as stipulated under the general provisions of tort law. The dissertation is structured into an introduction, four chapters and a conclusion. The first chapter outlines the foundations for the analysis of directors' liability for torts. In the second chapter, the author tackles the topic of liability that directors bear under civil law for any tortious acts they commit, concluding that directors are liable to compensate any damage caused by a tort committed by them while acting for the relevant corporation. The director's personal liability vis-à-vis the aggrieved party for any tort committed is not prejudiced by the fact that the director committed the tort while performing his/her tasks; this circumstance only means that the tort will be attributed to the legal person, which then is liable for the tort together with the director. The author primarily argues here that the principles governing legal representation are not applicable to torts committed by directors, and the legal consequences of the tort thus cannot be attributed solely to the legal person...
293

Tabák jako předmět spotřební daně de lege lata a de lege ferenda / Tobacco as subject of excise tax

Hanák, Radim January 2021 (has links)
Tobacco as subject of excise tax Abstract The subject of my work is the excise duty on tobacco products and tobacco in all its forms. Tobacco is a very specific product in terms of taxation in comparison with other products taxed by excise duty. Whether it is the issue of labeling tobacco products, filing tax returns, or the method of packaging and price regulation, in all these areas, the administration of excise duty on tobacco products is a completely separate piece of legislation, which differs significantly from the administration of other excise duties. All these institutes are analyzed in detail, including consideration of the relevant case law of administrative courts. Complementary to tax regulation of tobacco products is the excise duty on raw tobacco, which is a new type of excise duty (which is not harmonized by European Union law). A novelty in the field of excise duties across the European Union but also globally is the tax on heated tobacco products, which has been enshrined in all legal systems in recent years. The aim of my work is a thorough analysis of all the above areas. Also due to the reason that in the Czech Republic, the excise duty on tobacco products and tobacco has not yet been the subject of one comprehensive publication. In the area of tobacco product legislation, I will...
294

Povinnost loajality člena statutárního orgánu obchodní společnosti a povinnost loajality společníka obchodní společnosti v jejich vzájemném srovnání / Comparison of duty of loyalty of a member of governing body of a company and duty of loyalty of a company member

Hubáček, Tomáš January 2020 (has links)
The Duty of Loyalty of a Director of a Company and the Duty of Loyalty of a Member of a Company in Their Mutual Comparison Abstract According to the valid legislation, both the member of a company and the director of a company are subject to the duty of loyalty. The duty of loyalty has different content in relation to these persons and affects them with different intensity. The aim of this thesis is to compare selected aspects of the duty of loyalty of the member of company and the director of company. The first part presents initial doctrinal and judicial evolution of the duty of loyalty of the member of company and the director of company in the legal order of the Czech Republic. Furthermore, the essence (creative elements) of the duty of loyalty of mentioned persons is discussed. In this context, legal doctrine concludes that the essence of loyalty of the member of company and the director lies, amongst other matters, in contract. However, each of these persons has a different obligation, which is associated with different rights and duties of the relevant members of company's bodies. The aim of the first part is to develop the issue, which I consider crucial for understanding arguments and conclusions presented in the thesis. In the second part, I try to identify the interest which the member of company...
295

Modelling and Control of the AC-system in Heavy Duty Vehicles

Eriksson, Magnus January 2001 (has links)
The aim of this thesis is to investigate the Air Conditioning system in a heavy duty truck and to develop a control strategy for the case when low cooling capacity is needed from the AC-system. A model of the AC-system was developed in order for an efficient controller to be designed. The model was designed to comprise of all the basic behaviours that the AC- system has, rather than to be an exact model of the system. As the AC-system showed to be very complex, a number of limitations in the model had to be made. The AC-system has two temperature sensors and is actuated by turning the AC- compressor on or off. Two different control strategies were tested for the control of the AC-compressor. The first was to use a controller to directly control the compressor clutch and the second one utilised a pulswidth modulated control structure were the controller stated the pulswidth to be used. Both control structures were implemented in the computer model, the AC-rig and in a truck in a climate chamber. Both control strategies showed to fulfil the demands on the system in the somewhat idealistic circumstances during which they were tested.
296

Optimal Formation of Heavy Duty Vehicle Platoons

Dennis, Edblom January 2020 (has links)
Platooning has the potential to significantly reduce fuel consumption, but with heavy duty vehicles scattered on roads driving alone, there is a need for coordination. One solution is for a vehicle to increase its speed to catch up and platoon with a preceding vehicle. This could reduce the fuel consumption of a mission, but it could also increase it if too much fuel is spent catching up. By finding the fuel consumption of catching up and platooning and comparing it to driving alone the decision of whether or not to catch up can be made. This thesis proposes a fuel-optimal algorithm based on a look-ahead controller taking future road topography into account to find the optimal trajectory and merge point when catching up to a preceding vehicle. By weighting time against fuel in the objective function, the addition of a state to keep track of time can be avoided and thus the algorithm can remain low in complexity, making it suitable for dynamic programming (DP). The DP algorithm is iterated in a forward fashion keeping track of the time-to-come for each state until it catches up to the preceding vehicle, then the platooning is simulated with a constant time gap, making it easy and fast to simulate. The algorithm is tested on real-world road topography data where it showed that taking road topography into account when choosing the merge point can have a significant fuel reduction.
297

Fuel-Efficient Distributed Control for Heavy Duty Vehicle Platooning

Alam, Assad January 2011 (has links)
Freight transport demand has escalated and will continue to do so as economiesgrow. As the traffic intensity increases, the drivers are faced with increasinglycomplex tasks and traffic safety is a growing issue. Simultaneously, fossil fuel usageis escalating. Heavy duty vehicle (HDV) platooning is a plausible solution to theseissues. Even though there has been a need for introducing automated HDV platooningsystems for several years, they have only recently become possible to implement.Advancements in on-board and external technology have ushered in new possibilitiesto aid the driver and enhance the system performance. Each vehicle is able to serveas an information node through wireless communication; enabling a cooperativenetworked transportation system. Thereby, vehicles can semi-autonomously travel atshort intermediate spacings, effectively reducing congestion, relieving driver tension,improving fuel consumption and emissions without compromising safety. This thesis presents contributions to a framework for the design and implementation of HDV platooning. The focus lies mainly on establishing and validating realconstraints for fuel optimal control for platooning vehicles. Nonlinear and linearvehicle models are presented together with a system architecture, which dividesthe complex problem into manageable subsystems. The fuel reduction potentialis investigated through simulation models and experimental results derived fromstandard vehicles traveling on a Swedish highway. It is shown through analyticaland experimental results that it is favorable with respect to the fuel consumption tooperate the vehicles at a much shorter intermediate spacing than what is currentlydone in commercially available systems. The results show that a maximum fuelreduction of 4.7–7.7 % depending on the inter-vehicle time gap, at a set speedof 70 km/h, can be obtained without compromising safety. A systematic designmethodology for inter-vehicle distance control is presented based on linear quadraticregulators (LQRs). The structure of the controller feedback matrix can be tailoredto the locally available state information. The results show that a decentralizedcontroller gives good tracking performance, a robust system and lowers the controleffort downstream in the platoon. It is also shown that the design methodologyproduces a string stable system for an arbitrary number of vehicles in the platoon,if the vehicle configurations and the LQR weighting parameters are identical for theconsidered subsystems. With the results obtained in this thesis, it is argued that a vast fuel reductionpotential exists for HDV platooning. Present commercial systems can be enhancedsignificantly through the introduction of wireless communication and decentralizedoptimal control. / QC 20111012
298

Development of a Novel Method for Lithium-Ion Battery Testing on Heavy-Duty Vehicles

Svens, Pontus January 2011 (has links)
Increasing demands for lower environmental impact from vehicles, including heavy-duty vehicles, have driven several vehicle manufacturers to consider adding hybrid electrical vehicles (HEV’s) to the product portfolio. Present research on batteries for HEV’s is mainly focused on lithium-ion battery chemistries, since lithium-ion batteries has the most promising technical potential compared to other types of batteries. However, the uncertainty regarding battery lifetime combined with a high battery cost can have a negative impact on large scale commercialisation of heavy-duty hybrid vehicles in the near future. A large part of present lithium-ion battery research is focused on new materials, but there is also research focusing on ageing of already established lithium-ion battery chemistries. Cycle ageing of batteries often includes complete charging and discharging of batteries or the use of standardized test cycles. Battery cycling in real HEV applications is however quite different compared to this kind of laboratory testing, and real life testing on vehicles is a way of verifying the soundness of laboratory ageing. The aim of this study was to develop a test method suitable for real life testing of lithium-ion batteries for heavy-duty HEV-usage, with the purpose of investigating the correlation of battery ageing and usage in real life applications. This concept study includes both cell level battery cycling and performance testing on board vehicles. The performance tests consist of discharge capacity measurements and hybrid pulse power characterization (HPPC) tests. The main feature of this test equipment is that it is designed to be used on conventional vehicles, emulating an HEV environment for the tested battery. The functionality of the equipment was verified on a heavy-duty HEV with satisfying results. Results from real life testing of 8 batteries using the developed test equipment on four conventional heavy-duty trucks shows that the concept of comparing battery ageing with battery usage has a most promising potential to be used as a tool when optimizing battery usage vs. lifetime. Initial results from this real life study shows significant differences in state of charge (SOC) and power distributions between cycled batteries, but so far only small differences in ageing. Lithium-ion batteries of the type lithium manganese spinel/lithium titanate (LMO/LTO) were used in this study. / Ökande krav på minskad miljöpåverkan från fordon, inklusive tunga fordon, har drivit flera fordonstillverkare till att addera hybridiserade fordon till produktportföljen. Forskning på hybridfordonsbatterier är idag huvudsakligen inriktad på litiumjonbatterikemier, vilken har den mest lovande tekniska potentialen jämfört med andra typer av batterikemier. Det finns idag en risk att osäkerheten kring litiumjonbatteriers livslängd i kombination med en hög batterikostnad kan ha en negativ inverkan på en storskalig kommersialisering av tunga hybridfordon inom den närmsta framtiden. En stor del av batteriforskningen är inriktad på nya material, men det finns även forskning som fokuserar på åldring av redan etablerade litiumjonbatterikemier. Vid åldringsprov används ofta standardiserade testcykler eller cykler där batterierna blir fullständigt laddade och urladdade. Cykling av batterier i verkliga förhållanden skiljer sig dock från den typen av laboratorietester och provning på fordon är därför ett sätt att kontrollera att laboratorieprovning ger relevanta resultat gällande åldring. Syftet med denna studie var att utveckla en testmetodik lämplig för provning av litiumjonbatterier för tunga hybridfordon i verklig drift, med syfte att undersöka kopplingen mellan batteriers åldrande och hur det används. Detta koncept inkluderar battericykling på cellnivå och möjligheten att utföra batteriprestandatester på fordon, där prestandatesterna består av kapacitetsprov och pulsprov. Den viktigaste egenskapen hos den utvecklade testmetodiken är att provning sker på konventionella fordon genom att emulera en hybridmiljö för det testade batteriet. Funktionaliteten hos den utvecklade testutrustningen verifierades på en tung hybridlastbil med goda resultat. Resultaten från en fältstudie av 8 batterier på 4 lastbilar där den utvecklade testutrustningen användes påvisar att testmetodiken har en lovande potential att kunna användas som ett verktyg vid optimering av utnyttjandegrad och livslängd för HEV-batterier. De initiala resultaten från denna fältstudie påvisar skillnader i laddningsgradsfördelning och batterieffektfördelning mellan cyklade batterier, men ännu bara små skillnader i åldring. Litiumjonbatterier av typen litiummanganspinel/litiumtitanat (LMO/LTO) användes i denna studie. / QC 20111205
299

Predictive control for autonomous driving : With experimental evaluation on a heavy-duty construction truck

Lima, Pedro January 2016 (has links)
Autonomous vehicles is a rapidly expanding field, and promise to play an important role in society. In more isolated environments, vehicle automation can bring significant efficiency and production benefits and it eliminates repetitive jobs that can lead to inattention and accidents. The thesis addresses the problem of lateral and longitudinal dynamics control of autonomous ground vehicles with the purpose of accurate and smooth path following. Clothoids are used in the design of optimal predictive controllers aimed at minimizing the lateral forces and jerks in the vehicle. First, a clothoid-based path sparsification algorithm is proposed to efficiently describe the reference path. This approach relies on a sparseness regularization technique such that a minimal number of clothoids is used to describe the reference path. Second, a clothoid-based model predictive controller (MPCC) is proposed. This controller aims at producing a smooth driving by taking advantage of the clothoid properties.  Third, we formulate the problem as an economic model predictive controller (EMPC). In EMPC the objective function contains an economic cost (here represented by comfort or smoothness), which is described by the second and first derivatives of the curvature.  Fourth, the generation of feasible speed profiles, and the longitudinal vehicle control for following these, is studied. The speed profile generation is formulated as an optimization problem with two contradictory objectives: to drive as fast as possible while accelerating as little as possible. The longitudinal controller is formulated in a similar way, but in a receding horizon fashion. The experimental evaluation with the EMPC demonstrates its good performance, since the deviation from the path never exceeds 30 cm and in average is 6 cm. In simulation, the EMPC and the MPCC are compared with a pure-pursuit controller (PPC) and a standard MPC. The EMPC clearly outperforms the PPC in terms of path accuracy and the standard MPC in terms of driving smoothness. / <p>QC 20160503</p> / iQMatic
300

Speech Rights of Public Employees in the World of Social Media

Hairgrove, Benjamin Council 12 1900 (has links)
Legal rights for public employees are not clear in the area of social media speech. Following the Garcetti v Ceballos (2006) U.S. Supreme Court case, the pursuant to duty test was established. The social media speech of public employees, including educators, could be considered pursuant to their duties as an employee. This means that public employees are vulnerable to disciplinary action from their employer for social media speech. Furthermore, public employees are vulnerable even when they believe their social media speech is done as a private citizen. For this research study, 28 cases at the federal and state levels were analyzed. Seven of the examined cases were U.S. Supreme Court cases involving public employee speech rights. The other 21 cases were extracted from cases determined at the federal and state levels. The cases taking place after the Garcetti v Ceballos (2006) pursuant to duty test were analyzed to see how the test was applied to employee speech. Cases were also analyzed to see what other precedents from the courts had been applied. Additionally, private sector social media rights research was analyzed and reviewed to create more clarity for employees. The findings of the research show the courts have tested employee speech under the Pickering balancing test and the pursuant to duty test. The results of the case analyses were applied to provide clarity to employees regarding social media speech rights. Employee social media speech has to pass both tests to allow First Amendment protections. Employers need to create organization policy and training on this matter to protect the interest of both the organization and employees regarding avoidance of controversy.

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