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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.
41

Asset securitization. Mortgage pass Through-Products,and Relative Problems

Chen, Hui 28 August 2003 (has links)
none
42

Efficient Traffic Control Protocols for Vehicular Ad-Hoc Networks

Bani Younes, Maram Younis Saleh January 2015 (has links)
Traffic efficiency applications over road networks have been investigated recently using VANETs. This area of research is primarily concerned with increasing the traffic fluency over road networks. In this thesis, we first propose an efficient and accurate protocol to detect congested road segments in a downtown area using VANETs. We refer to this protocol as the Efficient COngestion DEtection (ECODE) protocol. ECODE evaluates three different traffic characteristics of each road segment including traffic speed, traffic density, and the time required to travel the segment. Moreover, ECODE evaluates traffic characteristics and detects the congestion level in each direction of the road segment. In addition, we propose an intelligent, dynamic, distributed, and real-time path recommendations protocol. We refer to this protocol as Intelligent path reCOmenDation (ICOD) protocol. ICOD is the first path recommendation protocol that does not rely on a central database of gathered traffic data for each area of interest. Eliminating centralized behavior resolves bottleneck as well as single point of failure problems, which in turn minimizes congestion and collision problems in VANETs. Furthermore, ICOD selects the path towards each destination in a hop-by-hop manner, which makes the turn decision at each road intersection more accurate and real-time. Different variants of ICOD are introduced that consider travel time, travel distance, fuel consumption, gas emissions, and context-awareness of each road segment parameters. Moreover, two traffic balancing mechanisms are proposed in this thesis to distribute traffic over the road network evenly, namely Bal-Traf and Abs-Bal. These mechanisms eliminate the highly congested road segment scenarios that are caused by the path recommendation protocol. Bal-Traf detects and eliminates the highly congested output road segment at each road intersection. However, Abs-Bal aims to keep the traffic density balanced among all output road segments at each road intersection. Finally, we propose an Intelligent Traffic Light Controlling (ITLC) algorithm to schedule the phases of each traffic light at isolated road intersections. This algorithm aims to decrease the queuing delay time of competing traffic flows and to increase the throughput of each signalized road intersection. ITLC has also been adapted in this thesis to the Arterial Traffic Lights (ATLs) algorithm for arterial road network scenarios. In ATLs the expected platoons on the arterial street are considered in the scheduling algorithm of each traffic light located on the arterial street coordinates. Transmitting packets among these traffic lights report the main characteristics of each predicted platoon.
43

Modelado y verificación experimental del comportamiento a traccion de probetas bimaterial termoplasticas. (PP-PE y ABS-HIPS)

Martínez Sanz, Antonio Vicente 21 March 2016 (has links)
[EN] The injection process is a very important part of the manufacture of thermoplastics. They are used for the fabrication of a wide variety of products because they comply perfectly with the overall objectives of low cost, precise size and almost the complete elimination of defects in the finished product. Many publications and scientific studies have been completed about the determination and control of the set of variables that affect the above-mentionned technological process. There are more and more applications for thermoplastics in a variety of areas such as the automotive and sports sectors. This thesis researches if computer programs can predict the behavior of materials that are used in the injection process. The quality of the predictive data depends on the properties of the materials injected, the variables of the tests and the mathematic models that can be used to simulate the behavior. Thanks to the simulation process, results can be combined and ordered so they can be used for comparison in real trials and they can be analyzed in order to confirm the conclusions on the behavior. / [ES] Dentro de los procesos de conformado de los termoplásticos destaca por su importancia industrial el proceso de Inyección. Se emplea para la fabricación de una gran diversidad de productos debido a que cumple perfectamente con los objetivos globales de minimización de costes económicos, errores dimensionales finales y práctica desaparición de defectos en las piezas terminadas. Se han realizado muchas publicaciones y estudios científicos para la determinación y control del conjunto de variables que afectan a dicho proceso de transformación. Este estudio busca dar un paso más en la generación de conocimiento, ya que se han detectado posibilidades de empleo de materiales termoplásticos bimateriales en el sector deportivo y en el de accesorios de automoción, siendo necesario el estudio y determinación de las posibilidades reales de empleo de programas informáticos de simulación en este tipo de piezas coinyectadas para la predicción del comportamiento mecánico en este tipo de procesos específicos. La calidad predictiva de las informaciones técnicas obtenidas depende de las propiedades de los materiales a coinyectar, variables de los ensayos y de los modelos matemáticos susceptibles de empleo para la simulación del comportamiento. Permitirá aglutinar de forma ordenada los resultados obtenidos mediante el proceso simulado, para su comparación con los ensayos reales para su análisis y obtención de conclusiones. / [CAT] Dins dels processos de conformat dels termoplàstics destaca per la seva importancia industrial el procés de Injecció. S'utilitza per a la fabricació d'una gran diversitat de productes donat que compleix perfectament amb els objectius globals de minimització de costos econòmics, errors dimensionals finals i pràctica desaparició de defectes en les peces acabades. S'han realitzat moltes publicacions i estudis científics per a la determinació i control del conjunt de variables que afecten aquest procés de transformació. Aquest estudi busca donar un pas més enllà a la generació de coneixement, ja que s'han detectat possibilitats d'ocupació de materials termoplàstics constituïts per dos materials al sector esportiu i al d'accessoris d'automoció. Es fá, per tant, necessari l'estudi i determinació de les possibilitats reals d'ocupació de programes informàtics de simulació en aquest tipus de peces coinyectadas per a la predicció del comportament mecànic en aquest tipus de processos específics. La qualitat predictiva de les informacions tècniques obtingudes depèn de les propietats dels materials a coinyectar, variables dels assajos i dels models matemàtics susceptibles d'ocupació per a la simulació del comportament. Ens permetrà aglutinar de forma ordenada els resultats obtinguts mitjançant el procés simulat, per la seva comparació amb els assajos reals per a la seva anàlisi i obtenció de conclusions. / Martínez Sanz, AV. (2016). Modelado y verificación experimental del comportamiento a traccion de probetas bimaterial termoplasticas. (PP-PE y ABS-HIPS) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61970 / TESIS
44

Návrh řídícího algoritmu ABS pro nákladní vozidlo / Development of ABS Control Algorithm for Heavy Commercial Vehicle

Slepánek, David January 2018 (has links)
This thesis is concerned with ABS algorithm project for commercial vehicles. In the first part the reader is introduced to the history and first usage of the anti-blocking system, its principles and main functions. There are also driving algorithms and functionality system control. The second part is dedicated to the dynamic model, programs and ADAMS Car and MATLAB Simulink interfaces. It also contains the description of the algorithm, its parameters and basic functionality assay. Simulation, program interlink, testing and tuning are also described. The concluding part deals with results and their assessment.
45

Výroba Krytu konektoru / Manufacture of connector cover

Lukeštík, Tomáš January 2021 (has links)
The work presents a proposal for the production of the connector cover by injection molding from amorphous ABS polymer. Based on a literature study of injection technology and calculations, a two-part injection mold with four cavities, equipped with side sliding trolleys, was designed. The mold is composed of standardized components, some of which are modified. An Intec D100 / 380-B injection molding machine was chosen. The work is accompanied by drawing documentation of the assembly of the mold, molding plates and the designed side sliding trolleys.
46

Povrchová úprava ABS součástí po 3D FDM tisku / Surface treatment of ABS parts after FDM 3D print

Světlík, David January 2015 (has links)
This master thesis deals with the surface treatment of parts made of plastic produced using FDM technology and design of technological device for surface treatment. The thesis describes FDM principles, according to performed experiments in a technological device there are suggested technological conditions for the surface treatment of parts made of ABS plastic. In the end of the thesis, there are calculated costs of the technological device and its operating costs, also mechanical properties, surface roughness and other specifications from before and after the treatment are compared.
47

Värdepapperisering i Sverige : Finns det en marknad?

Folcker Carlsson, Rickard, Rockström, Tomas January 2012 (has links)
As of today, securitization is an established product on the capital market. The first transaction was made in the US in the 1970s. Since then the product has been developed and today there are several different structures of the product. Internationally securitization has been used for two reasons. Originally securitization was used to gain capital relief, but since capital requirements such as Basel II were implemented, the usage of securitization changed to more of a funding source. The purpose with this paper is to highlight the benefits and risks concerning securitization and to investigate the demand for securitization on the Swedish market. If the demand was found to be low, we would further examine why it’s low. We have investigated which assets are best suited for securitization and above all how the Swedish market will develop in the future. Securitization has been studied all across the world mainly due to the financial crisis, but studies from Sweden is lacking. Our literary sources are complemented with empirical knowledge through interviews of people with expertise in securitization. The paper is divided into three parts. The first part will deal with the theoretical aspects regarding securitization. The second part will process the empirical angels of securitization. In the third part we present an analysis and our own reflections on the subject. The Swedish securitization market has historically seen rather few transactions, despite the strength of the Swedish economy. Our research found that the assets used for securitization is mainly residential mortgage portfolios and consumer credits. These assets have certain characteristics and most importantly they are generating a good cash flow and can be structured in vast numbers to diversify a bank’s portfolio. How the market will develop in the future depends on how the bank sector will respond to Basel III requirements, the structure of future transactions and the competence of originators and buyers.
48

Tillverkning av Akrylnitril-Butadien-Styren (ABS)-filament förstärkt med fibrer av mikrocellulosa

Folebäck, Eric January 2021 (has links)
Termoplaster används i en mängd olika produkter världen över. En starkare termoplast kan leda till att en mindre mängd material behövs för att bibehålla samma styrka i en produkt. En lättare produkt kan exempelvis leda till minskad bränsleförbrukning vilket är positivt i avseende för miljön, socialt och ekonomiskt.  Ett möjligt sätt att tillverka en starkare termoplast skulle kunna vara att förstärka den med cellulosafibrer. FineCell Sweden AB tillverkar cellulosafibrer i mikrostorlek genom en miljövänlig och energieffektiv kemisk process, vilket resulterar i en ekologiskt hållbar produkt. Nya tillverkningsmetoder som additiv tillverkning tillåter nya möjligheter för de former som kan tillverkas med termoplaster. Det är intressant att undersöka om det går att använda en cellulosaförstärkt termoplast till 3D-printning. Detta examensarbete har fokuserat på extrudering av mikrocellulosaförstärkt filament, och hur olika tillverkningsprocesser påverkar kvalitén och hur de mekaniska egenskaperna påverkas. Resultatet visar att mikrocellulosan i vissa fall kan ge ökad elasticitetsmodul, och att torkning och hantering av cellulosan innan extrudering är avgörande för egenskaperna, då eventuell fukt leder till porer vilka påverkar de mekaniska egenskaperna negativt.  I vidare arbete skulle fler materialegenskaper för det tillverkade filament vara intressant att undersöka. Det skulle vara intressant att tillverka filament med en ”Twin-screw” extruder, då det kan fördela fibrerna och skjuva till mindre storlek. Det skulle även vara intressant att undersöka mikrocellulosaförstärkning med andra typer av tillverkningsmetoder, högre fiberandelar och andra sorters termoplaster. / Thermoplastics are used in a variety of products worldwide. A stronger thermoplastic could lead to a smaller amount being needed to maintain the same strength in a product. A lighter product can, for example, lead to reduced fuel consumption, which is positive for the environment, socially and economically. One possible way to make a stronger thermoplastic could be to reinforce it with cellulose fibers. FineCell Sweden AB manufactures micro-sized cellulose fibers through an environmentally friendly and energy-efficient chemical process, which results in an ecologically sustainable product. New manufacturing methods such as additive manufacturing allows new possibilities for the shapes that can be manufactured with thermoplastics. It is interesting to investigate whether it is possible to use a cellulose-reinforced thermoplastic for 3D-printing. This master thesis has focused on the extrusion of microcellulose-reinforced filament and how different manufacturing methods affect the quality and how the mechanical properties are affected. The results show that the microcellulose can in some cases give an increased modulus of elasticity and that drying and handling of the cellulose before extrusion is decisive for the properties, as any moisture leads to pores which adversely affect the mechanical properties. In further work, more material properties of the manufactured filament would be interesting to investigate. It would be interesting to make filaments with a "twin-screw" extruder, as it can distribute the fibers and shear to a smaller size. It would also be interesting to investigate microcellulose amplification with other types of manufacturing methods, higher fiber ratios and other types of thermoplastics.
49

Design and Testing of Digitally Manufactured Paraffin Acrylonitrile-Butadiene-Styrene Hybrid Rocket Motors

McCulley, Jonathan M. 01 May 2013 (has links)
This research investigates the application of additive manufacturing techniques for fabricating hybrid rocket fuel grains composed of porous Acrylonitrile-butadiene-styrene impregnated with paraffin wax. The digitally manufactured ABS substrate provides mechanical support for the paraffin fuel material and serves as an additional fuel component. The embedded paraffin provides an enhanced fuel regression rate while having no detrimental effect on the thermodynamic burn properties of the fuel grain. Multiple fuel grains with various ABS-to-Paraffin mass ratios were fabricated and burned with nitrous oxide. Analytical predictions for end-to-end motor performance and fuel regression are compared against static test results. Baseline fuel grain regression calculations use an enthalpy balance energy analysis with the material and thermodynamic properties based on the mean paraffin/ABS mass fractions within the fuel grain. In support of these analytical comparisons, a novel method for propagating the fuel port burn surface was developed. In this modeling approach the fuel cross section grid is modeled as an image with white pixels representing the fuel and black pixels representing empty or burned grid cells. (80 pages)
50

Detekce brzdných stop pomocí spektrometrie laserem indukovaného plazmatu (LIBS) a spektrometrie laserem indukované fluorescence (LIBS + LIFS) / Detection of Braking Tracks using Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Induced Fluorescence Spectroscopy (LIBS + LIFS)

Prochazka, David January 2014 (has links)
The aim of this work is to investigate the potential of Laser-Induced Breakdown Spectroscopy (LIBS) for identification of visually unrecognizable braking tracks. Identification of these tracks is based on different chemical composition of tire tread in comparison to road surface. The investigation was divided in several sequential steps – selection of suitable chemical element and its spectral line for break tracks identification; determination of the limits of detection and threshold intensity respectively for the selected chemical element; verification of LIBS ability to detect braking tracks on a real braking track. This testing braking track was prepared by exactly defined and described conditions. The detection was performed in two ways – laboratory analysis of tire treads particles collected via adhesive tape and in situ analysis via mobile apparatus. Results of both measurements showed that LIBS is able to detect visually unrecognizable braking tracks. Concepts of the devices capable of routine braking tracks identification for both possibilities were introduced.

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