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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.
161

Comparisons and modelling of primary vacuum standards

Music, Vesna January 1999 (has links)
No description available.
162

Joseph Conrad : his dialogic poetics

Kang, Sukjin January 1998 (has links)
No description available.
163

Theoretical and experimental investigations on the kinetics of the axisymmetric membranes subject to initial impact

Ghosh, Swadhin Kumar January 1979 (has links)
No description available.
164

A relational approach to optimization problems

Curtis, Sharon January 1996 (has links)
No description available.
165

Stable boundary conditions for the shallow water equations

Burgess, N. A. January 1987 (has links)
No description available.
166

A High Dynamic Range Microwave Fiberoptic Link for Telemetry/Tracking Systems

Grimes, W. Gary, Curran, Randy 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1992 / Town and Country Hotel and Convention Center, San Diego, California / This paper presents a simple, cost-effective solution that permits the antenna in a telemetry/tracking system to be placed at distances even greater than 20 km with virtually no signal degradation. By using a wideband, microwave fiberoptic link to pass the RF telemetry and tracking signals directly, the telemetry receivers can all be installed at the operator's location. In essence, the only RF equipment that needs to be installed at the antenna site is the low maintenance fiberoptic transmitter which can be placed in a ruggedized housing at the pedestal. The actual system described herein uses a hybrid approach with some telemetry receivers at the antenna site and some remoted over the fiberoptic link. It is shown that the fiberoptic link used met and exceeded the system requirements. In addition, the design of the fiberoptic link is discussed and it is shown that the dynamic range acheivable with this fiberoptic link is considerably higher than the system requirements in this case.
167

Dynamic partial reconfiguration management for high performance and reliability in FPGAs

Ebrahim, Ali January 2015 (has links)
Modern Field-Programmable Gate Arrays (FPGAs) are no longer used to implement small “glue logic” circuitries. The high-density of reconfigurable logic resources in today’s FPGAs enable the implementation of large systems in a single chip. FPGAs are highly flexible devices; their functionality can be altered by simply loading a new binary file in their configuration memory. While the flexibility of FPGAs is comparable to General-Purpose Processors (GPPs), in the sense that different functions can be performed using the same hardware, the performance gain that can be achieved using FPGAs can be orders of magnitudes higher as FPGAs offer the ability for customisation of parallel computational architectures. Dynamic Partial Reconfiguration (DPR) allows for changing the functionality of certain blocks on the chip while the rest of the FPGA is operational. DPR has sparked the interest of researchers to explore new computational platforms where computational tasks are off-loaded from a main CPU to be executed using dedicated reconfigurable hardware accelerators configured on demand at run-time. By having a battery of custom accelerators which can be swapped in and out of the FPGA at runtime, a higher computational density can be achieved compared to static systems where the accelerators are bound to fixed locations within the chip. Furthermore, the ability of relocating these accelerators across several locations on the chip allows for the implementation of adaptive systems which can mitigate emerging faults in the FPGA chip when operating in harsh environments. By porting the appropriate fault mitigation techniques in such computational platforms, the advantages of FPGAs can be harnessed in different applications in space and military electronics where FPGAs are usually seen as unreliable devices due to their sensitivity to radiation and extreme environmental conditions. In light of the above, this thesis investigates the deployment of DPR as: 1) a method for enhancing performance by efficient exploitation of the FPGA resources, and 2) a method for enhancing the reliability of systems intended to operate in harsh environments. Achieving optimal performance in such systems requires an efficient internal configuration management system to manage the reconfiguration and execution of the reconfigurable modules in the FPGA. In addition, the system needs to support “fault-resilience” features by integrating parameterisable fault detection and recovery capabilities to meet the reliability standard of fault-tolerant applications. This thesis addresses all the design and implementation aspects of an Internal Configuration Manger (ICM) which supports a novel bitstream relocation model to enable the placement of relocatable accelerators across several locations on the FPGA chip. In addition to supporting all the configuration capabilities required to implement a Reconfigurable Operating System (ROS), the proposed ICM also supports the novel multiple-clone configuration technique which allows for cloning several instances of the same hardware accelerator at the same time resulting in much shorter configuration time compared to traditional configuration techniques. A faulttolerant (FT) version of the proposed ICM which supports a comprehensive faultrecovery scheme is also introduced in this thesis. The proposed FT-ICM is designed with a much smaller area footprint compared to Triple Modular Redundancy (TMR) hardening techniques while keeping a comparable level of fault-resilience. The capabilities of the proposed ICM system are demonstrated with two novel applications. The first application demonstrates a proof-of-concept reliable FPGA server solution used for executing encryption/decryption queries. The proposed server deploys bitstream relocation and modular redundancy to mitigate both permanent and transient faults in the device. It also deploys a novel Built-In Self- Test (BIST) diagnosis scheme, specifically designed to detect emerging permanent faults in the system at run-time. The second application is a data mining application where DPR is used to increase the computational density of a system used to implement the Frequent Itemset Mining (FIM) problem.
168

Some recent contributions to fluid flow measurement and instrumentation

Hopkins, D 05 February 2015 (has links)
No description available.
169

Dynamic Pricing : A Matter of Attitude

Holmqvist Larsson, Johanna, Tapper, Fanny January 2019 (has links)
Tillämpningen av dynamisk prissättning har förenklats genom digitaliseringens framväxt. Med den ökade tillgången till kunddata kan företag idag kartlägga kundernas köpbeteende och genom algoritmer anpassa priserna därefter. Identiska varor och tjänster kan således prissättas, utefter kundens köpvillighet. För företaget utgör denna prissättning en möjlighet till ökad lönsamhet, men ur ett kundperspektiv kan detta tänkas skapa känslor av orättvisa och lurendrejeri. Samtidigt har det visat sig vara desto viktigare i en digital miljö att se till kundnöjdhet, eftersom det finns en högre pristransparens och kunderna har lägre engagemang och lojalitet. Det kan därför ifrågasättas om ett företag i längden tjänar på att använda sig av dynamisk prissättning om den skadar relationen till kunden. Syftet med denna studie är således att undersöka sambandet mellan kundattityd och dynamisk prissättning. För att undersöka kundattityd skapas en modell utifrån teori med komponenterna kundvärde, kundnöjdhet, kvalitet, kundlojalitet, förtroende och rättvisa. Modellen används för att undersöka hur en prisändring påverkar kundens attityd mot dynamisk prissättning. Studiens analys grundar sig på empiriska data som samlats in genom virtuella fokusgruppsdiskussioner. Dataunderlaget utgörs av fem fokusgruppsdiskussioner, med totalt 31 deltagare. Studien visar att kundernas attityd till företaget påverkas negativt av dynamisk prissättning. Dock framhäver studien att kundvärdet skapas i andra kvaliteter än pris. Trots en initial negativ inställning påvisas att det finns en viss grad av kundanpassning och utveckling av köpstrategier hos kunderna.
170

The application of enhanced fluid dynamic gauging as a fouling sensor for pressure driven membrane separations in the food industry

Jones, Sarah January 2012 (has links)
The aim of this study was to further understand the fouling and cleaning mechanisms of synthetic membranes used to filter an industrially relevant feed. The main focus of this study was to understand the fouling layer properties during pressure driven filtration. A relatively new technique known as Fluid Dynamic Gauging (FDG) was applied to examine the fouling layer thickness. This work comprised of four main themes with overlapping objectives: (i) the optimisation of Spent Sulphite Liquor fouling and cleaning conditions, (ii) the optimisation of molasses fouling and cleaning conditions, (iii) the investigation of the effect of a simple pre-treatment upon the membrane separation performance, and (iv) the application of the FDG in the study of polymeric membranes. An understanding of the mechanisms involved in fouling and cleaning of microfiltration and ultrafiltration membranes used to filter molasses and SSL has been attained. The variables affecting permeate flux and quality were optimised and mechanistic information concerning the synergistic effects between fouling and cleaning was gathered. The application of a simple NaOH pre-treatment was found to affect both the type of foulant species attaching to the membrane surface, and resulted in an altered separation and cleaning performance. Zeta potential measurements, FTIR and AFM demonstrated that both in-pore and surface fouling was present. The data collected indicated that for both membranes evaluated, different fouling species were found to have attached, depending upon the pre-treatment protocol used. These findings are significant, as they offer support to the recommendations made by some polymeric membrane manufacturers that conditioning protocols should include a NaOH step. However, in the SSL system examined, the effect of NaOH pre-treatment resulted in an improvement in the subsequent performance only over the first two or three complete filtration cycles. It is therefore necessary to study membrane systems over multiple fouling and cleaning cycles before a recommendation can be made. An improved understanding of the interaction between the surface chemistry and surface physics during membrane filtration of complex food based material will benefit both membrane manufactures and food industry based users. The technique of Fluid Dynamic Gauging was incorporated into an existing system and validated to monitor the development of cake layers over time. The FDG was also used to optimise conditions and track the thickness of the cake layer during multiple fouling cycles and its removal rate during cleaning, as an aid to understanding removal mechanisms. It has been shown that operating conditions have to be carefully chosen to minimise the effect of membrane fouling. The results show that FDG is a versatile and powerful technique for characterising the dynamics and mechanical behaviour of fouling layers on membrane surfaces. A particular advantage of the FDG technique is its ability to determine the thickness of fouling layers where other techniques would find difficulty. For example, the layers formed in this study were opaque, and consequently the determination of the development of deposit thickness with time would have been very challenging using conventional optical microscopy techniques.

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