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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.
1

Embedded Clauses

Carnie, Andrew January 2007 (has links)
Elicitation of embedded clauses
2

Garden Monitoring with Embedded Systems

von Hacht, Karl-Johan January 2015 (has links)
In today’s modern society the process of handling crops in an accountable way withoutloss have become more and more important. By letting a gardener evaluate the progressof his plants from relevant data one can reduce these losses and increase effectiveness ofthe whole plantation. This work is about the construction of such a system composedfrom a developers perspective of three different platforms, from the start of data samplingwithin the context of gardening to and end user easily able to understand the data thentranslated. The first platform will be created from scratch with both hardware andsoftware, the next assembled from already finished hardware components and build withsimpler software. The last will essentially only be a software solution in an alreadyfinished hardware environment.
3

Shape detection and localization of a scatterer embedded in a halfplane

Jeong, Chanseok, 1981- 31 July 2015 (has links)
The inverse problem of detecting the shape and location of a rigid scatterer fully embedded in a halfplane based solely on surficial measurements of the scatterer's response to illumination by plane waves, is solved numerically in the frequency domain, using integral equations within the general framework of PDE-constrained optimization. Two different, but closely related, physical problems are considered: first, scatterers embedded in the soil where SH waves are used for detection, and secondly, scatterers embedded in an acoustic fluid, where pressure waves are used for detection. The elastic case of SH waves gives rise to a traction-free surface and an associated Neumann condition, whereas the acoustic case gives rise to a pressure-free surface and a Dirichlet condition, respectively. The measurement stations are sparsely located on the free surface and depending on the physical problem, either displacements are measured (SH case), or fluid velocities (or pressure gradients) are recorded (acoustic case). Localizing and detecting the shape of the scatterer entails matching the observed response to the response resulting from the scatterer's assumed location and shape. There arises a misfit minimization problem that is tackled using a PDE-constrained optimization approach, which, in turn, results in state, adjoint, and control problems, necessary for the satisfaction of the first- order optimality conditions. Boundary integral equations are used throughout, whereas operations over moving interfaces that arise naturally during the iterative search process, are treated using the apparatus of total differentiation.To alleviate inherent difficulties with solution multiplicity, amplitude-based misfits and continuation schemes are used. Numerical results, attesting to the efficacy of the methodology in detecting shapes and localizing scatterers, are discussed. / text
4

An implementation of an autonomous IoT system for real-time water quality monitoring with 4G and satellite connection : CatFish - Embedded systems

Elfing, Johan, Persson, Daniel January 2022 (has links)
This thesis is about implementing an Internet of Things system for measuring water quality in rivers and other aquatic environments with an autonomous water drone, where the data from various components are collected and sent wirelessly to the database in real-time. A Raspberry Pi is connected to the internet through a 4G modem and a wireless satellite communication connection called RockBlock for emergency calls and notifications. In addition, a sonar is also implemented to collect data for the unmanned surface vehicle's (USV) avoidance of collisions. Finally, batteries are connected to solar panels to auto-generate energy and provide the USV with its requested current and voltage. The minimum parameters to measure water quality are four: potential hydrogen, dissolved oxygen, nitrates, and colored dissolved organic matter. As a result, the system in this thesis measures the four parameters mentioned above, plus turbidity and temperature, since the interconnected sensors can also measure those. In addition, optical sensors were chosen because of their exceptional accuracy and precision when measuring water quality. The environment, mainly the aquatic, will benefit from this project and change for the better with time. / Den här vetenskapliga artikeln handlar om att implementera ett Internet of Things system avsett för att mäta vattenkvaliteten i floder och andra vattenmiljöer med en autonom vattendrönare, där datan från diverse komponenter samlas in och skickas trådlöst till databasen i realtid. En Raspberry Pi är ansluten till internet via ett 4G-modem samt en trådlös satellitkommunikationsanslutning som kallas RockBlock för nödmeddelanden och notifikationer. Dessutom implementeras ett ekolod för insamling av data till den autonoma vattendrönaren för undvikande avkollisioner. Slutligen är batterierna anslutna till solcellspaneler för att automatiskt generera energi och förse den autonoma vattendrönaren med tillräcklig ström samt spänning.Det minsta antalet parametrar för att mäta vattenkvalitet är fyra: potentiellt väte, löst syre, nitrat, och färgat löst organiskt material. Som ett resultat mäter systemet i denna avhandling de fyra parametrarna nämnda ovan, plusgrumlighet och temperatur, eftersom de sammankopplade sensorerna ocksåkan mäta dessa. Dessutom valdes optiska sensorer på grund av deras exceptionella noggrannhet och precision vid vattenkvalitetsmätning. Miljön, speciellt vattenmiljön, kommer att gynnas av detta projekt samt förändras till det bättre med tiden.
5

LOW-COST RAPID-RESPONSE EMBEDDED ANTENNA DESIGN FOR US ARMY 60MM MORTARS

Katulka, G., Hall, R., Peregino, P., Muller, P., Hundley, N., McGee, R. 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The Defense Advanced Research Projects Agency (DARPA) and the US Army are engaged in a high-risk/high-payoff project for the development of precision-guided 60mm mortars for the benefit of the optically designated attack munition (ODAM). This paper describes the antenna design and performance characteristics required for a telemetry-based onboard diagnostic system. Efforts executed at the U.S. Army Research Laboratory, Aberdeen Proving Ground, MD met our primary objective to demonstrate rapid response low-cost capability for body-mounted antennas compatible with commercially-available telemetry products. This presentation reviews the theoretical design and antenna radiation pattern characteristics, tuning process, and returned in-flight signal strength along the trajectory. Experimental results compared favorably with theoretical link analyses. Lessons learned, ongoing applications, and future improvements are also presented.
6

Object-oriented techniques applied to real-time systems

Maclean, Stuart Douglas January 1995 (has links)
No description available.
7

Evaluation of an active acoustic waveguide sensor for embedded structural monitoring

Atkinson, David January 2000 (has links)
This Thesis describes research aimed towards the realisation of an embedded ultrasonic monitoring system for operation in a smart structure environment. Alien fibres embedded within carbon fibre reinforced composite plates could be utilised to guide ultrasound to strategic release points for the interrogation of the test sample, with minimal structural degradation. In particular, an array of fibre waveguides could be utilised to deliver periodic stresses to a plate-type structure to excite Lamb wave propagation. With such a system several problems need to be addressed. Firstly, identification of an appropriate mode of propagation to transport the acoustic energy along the waveguide and meet the requirements of the system is required. Theoretical analysis of elastic wave propagation in cylinders is provided to establish the characteristics of the various supported modes. Subsequently, the longitudinal (axisymmetric) modes are highlighted as being the most appropriate for the proposed system. Ideally, such a mode should be singly generated to provide increased control on the coupling of ultrasound from the waveguide to the desired Lamb wave mode. Therefore, the transducer-fibre interface utilised for efficient single mode generation in the fibre waveguides is essential. This Thesis investigates a novel, cheap, simple, and robust coupling strategy, which employs a conical polymer bond to behave as a mechanical transformer efficiently coupling the lateral displacements of a piezoceramic transducer into longitudinal displacements in the waveguide. Theoretical and experimental analysis of this technique are described and design guidelines detailed. The Thesis then goes on to provide experimental and theoretical evidence of the fibre waveguide's ability to transport acoustic energy to and from plate-type structures for subsequent Lamb wave generation and detection. Initially, a surface mount strategy is adopted, whereby the ends of several thin cylindrical waveguides are bonded to the surface of aluminium plates to behave as a line array. Generation and detection of the fundamental symmetric (So) and asymmetric (A0) Lamb wave modes is demonstrated. Following this, the Thesis details considerations concerning the realisation of an embedded fibre waveguide monitoring system. Here, the choice of waveguide material and geometry is crucial to ensure the guided ultrasound does not leak into the structure at undesirable locations and that the structural integrity of the test sample is maintainable. Consequently, various waveguide configurations are investigated to establish an arrangement capable of meeting the system requirements. An embedded fibre waveguide Lamb wave system is then presented in a hard-setting polymer plate confirming the basic design methodology. Finally, So Lamb wave generation and detection in a carbon fibre reinforced composite plate is demonstrated utilising embedded acoustic waveguides sensors.
8

Flexible embedded software networks

D'Entremont, Marc. 10 April 2008 (has links)
My thesis investigates the collaboration and evolution of micro controller networks. In the thesis, I have developed a framework for flexibly connecting embedded systems, called microsynergy. The framework gives to users the ability unify a network of micro controller-based devices into logically defined collaborative networks. It establishes a communication infrastructure across a variety of networking protocols and allows dynamic reconfiguration of the micro controller network by means of a visual language. The infrastructure includes a mechanism for the construction and/or reuse of stateful coordination logic that manages the inter-communication of the network enabled devices and software components to create new functionalities and behaviours from a set of predefined software and hardware components. microsynergy looks at only a few of the issues, such as how to integrate devices with minimal impact on the code base, integrating devices of various protocols, building easy to understand and modifiable networks of devices that can act as a unified system. It include the design, implementation and analysis, through an informal user study, of a specific implementation of visual programming paradigm and its relation to collaborative networks.
9

Interactive web-based embedded systems

Lavender, Michael. 10 April 2008 (has links)
No description available.
10

Methodologies for Approximation of Unary Functions and Their Implementation in Hardware

Hertz, Erik January 2016 (has links)
Applications in computer graphics, digital signal processing, communication systems, robotics, astrophysics, fluid physics and many other areas have evolved to become very computation intensive. Algorithms are becoming increasingly complex and require higher accuracy in the computations. In addition, software solutions for these applications are in many cases not sufficient in terms of performance. A hardware implementation is therefore needed. A recurring bottleneck in the algorithms is the performance of the approximations of unary functions, such as trigonometric functions, logarithms and the square root, as well as binary functions such as division. The challenge is therefore to develop a methodology for the implementation of approximations of unary functions in hardware that can cope with the growing requirements. The methodology is required to result in fast execution time, low complexity basic operations that are simple to implement in hardware, and – sincemany applications are battery powered – low power consumption. To ensure appropriate performance of the entire computation in which the approximation is a part, the characteristics and distribution of the approximation error are also things that must be possible to manage. The new approximation methodologies presented in this thesis are of the type that aims to reduce the sizes of the look-up tables by the use of auxiliary functions. They are founded on a synthesis of parabolic functions by multiplication – instead of addition, which is the most common. Three approximation methodologies have been developed; the two last being further developments of the first. For some functions, such as roots, inverse and inverse roots, a straightforward solution with an approximation is not manageable. Since these functions are frequent in many computation intensive algorithms, it is necessary to find very efficient implementations of these functions. New methods for this are also presented in this thesis. They are all founded on working in a floating-point format, and, for the roots functions, a change of number base is also used. The transformations not only enable simpler solutions but also increased accuracy, since the approximation algorithm is performed on a mantissa of limited range. Tools for error analysis have been developed as well. The characteristics and distribution of the approximation error in the new methodologies are presented and compared with existing state-of-the-art methods such as CORDIC. The verification and evaluation of the solutions have to a large extent been made as comparative ASIC implementations with other approximation methods, separately or embedded in algorithms. As an example, an implementation of the logarithm made using the third methodology developed, Harmonized Parabolic Synthesis (HPS), is compared with an implementation using the CORDIC algorithm. Both implementations are designed to provide 15-bit resolution. The design implemented using HPS performs 12 times better than the CORDIC implementation in terms of throughput. In terms of energy consumption, the new methodology consumes 96% less. The chip area is 60% smaller than for the CORDIC algorithm. In summary, the new approximation methodologies presented are found to well meet the demanding requirements that exist in this area.

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