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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.
381

Measuring Test Coverage in Embedded Software Development Branches

Abed Jaser, Zaid, Al-Braichi, Osamah Haitham Sabhan January 2019 (has links)
Most of the hardware products today, especially those that people interact with, are controlled by software. There are many devices with inbuilt software which many people do not bother to notice. Software may be critical in terms of strict quality requirements due to failures which enable risks of endangering the production and more importantly the lives of people. The testing team of Westermo Network Technologies AB faced a challenge with not being able to identify the coverage of tested cases in software. Identifying the coverage of total executed test cases enables the possibility of knowing the potential future quality of a software. By reaching such a stage a software will likely not suffer from failures due to higher quality, therefore the lives of people and the production at stake will not get harmed. The essential problem is that test cases are both tested and skipped, which makes it more difficult for the company to identify what has been actually tested and skipped. The purpose of this thesis is to identify and calculate the coverage of test cases, the process was mainly to understand the essence in the identification of executed test cases. The ethical aspect of putting people's lives at stake is what inspired us to investigate software failures. Software is typically tested before a release, therefore our investigation was to research testing process of software. When investigating test result over many days and test systems we developed a coverage calculator system which helps Westermo to decide and determine the release of tested software, either the software test result is acceptable for a release or not.
382

Fault Tolerant and Flexible CubeSat Software Architecture

Manyak, Greg D. 01 June 2011 (has links)
The CubeSat pico-satellite is gaining popularity in both the educational and aerospace industries. Due to a lack of experience and constrained hardware capabilities, most of the university missions have been educational in nature. Cal Poly's project, PolySat, has gained significant experience from the launch of five CubeSats and has designed an entirely new hardware platform based on the knowledge gained from these missions. This hardware is a significant upgrade from what the previous missions used and has greatly increased the capabilities of the software, including supporting the use of the open source operating system Linux. Leveraging the previous PolySat experience, a new design approach has been followed for the development of a fault tolerant and flexible software architecture. As a result, a set of processes and custom libraries that run within Linux have been designed and implemented. Furthermore, an emphasis has been placed on fault tolerance with two features: a software watchdog and digital command signing capability. Lastly, a survey of related CubeSat projects and software fault tolerance papers has been conducted to determine that this new system is sufficient to meet the desired goals.
383

An Embedded Ring Approach to the Vibrational Dynamics of Disordered Two-Dimensional Materials

Doyle, Timothy Edwin 01 May 1992 (has links)
A theoretical approach was developed to model the vibrational dynamics of amorphous, two-dimensional materials. The materials were modeled as continuous random networks (CRN's) comprising an assemblage of planar rings of diverse size. In-plane vibrational modes for symmetric 4-, 5-, 60, 7-, and 8-membered rings were examined. Vibrational states of isolated rings were modified by coupling the rings to a continuous network to represent rings embedded in a CRN. An effective force constant was used to couple the ring vibrations to the network's collective motions. Potentials were approximated with the use of a central force model (bond-stretching force constant) and a valence force model (bond-stretching and bond-angle-bending force constants). Valence force model calculations employed group theory. Mode frequencies were calculated using the method of small oscillations and the normal coordinate treatment. Amorphous carbon was used as a test case for the embedded ring approach. A physically consistent set of force constants for the valence force model was determined by comparing the 6-membered ring E2g mode in graphite. Frequencies for selected ring modes were calculated, resulting in a discrete line spectrum. Calculated frequencies were fitted with gaussian peaks and convoluted into theoretical spectra for comparison with the experimental Raman spectrum of amorphous carbon. Integrated gaussian lineshape intensities were assumed to be directly proportional to the CRN ring statistics. The peaks were convoluted with the peak widths, ring statistics, and number of modes as the adjustable parameters. Parameters consistent with previous research on the structure and dynamics of amorphous carbon provided satisfactory fits to the data. The best fit to the Raman data includes the E2g and A1g modes of 6-membered rings (present in Raman spectra of nanocrystalline graphite), and the Raman active E2' modes of 5- and 7-membered rings. The corresponding ring statistics agree with previous results, supporting the presence of a sizable percentage of 5- and 7- membered rings, but with no 4- or 8-membered rings. This positive result provides verification for the embedded ring approach, and supports a CRN model for amorphous carbon.
384

Integration of Ultrasonic Consolidation and Direct-Write to Fabricate an Embedded Electrical System Within a Metallic Enclosure

Hernandez, Ludwing A. 01 December 2010 (has links)
A research project was undertaken to integrate Ultrasonic Consolitation (UC) and Direct-Write (DW) technologies into a single apparatus to fabricate embedded electrical systems within an ultrasonically consolidated metallic enclosure. Process and design guidelines were developed after performing fundamental research on the operational capabilities of the implemented system. In order to develop such guidelines, numerous tests were performed on both UC and DW. The results from those tests, as well as the design and process guidelines for the fabrication of an embedded touch switch, can be used as a base for future research and experimentation on the UC-DW apparatus. The successful fabrication of an embedded touch switch proves the validity of the described design and process parameters and demonstrates the usefulness of this integration.
385

Exploration of non-volatile magnetic memory for processor architecture / Exploration d'architecture de processeur à technologie mémoire non volatile MRAM

Senni, Sophiane 14 December 2015 (has links)
De par la réduction continuelle des dimensions du transistor CMOS, concevoir des systèmes sur puce (SoC) à la fois très denses et énergétiquement efficients devient un réel défi. Concernant la densité, réduire la dimension du transistor CMOS est sujet à de fortes contraintes de fabrication tandis que le coût ne cesse d'augmenter. Concernant l'aspect énergétique, une augmentation importante de la puissance dissipée par unité de surface frêne l'évolution en performance. Ceci est essentiellement dû à l'augmentation du courant de fuite dans les transistors CMOS, entraînant une montée de la consommation d'énergie statique. En observant les SoCs actuels, les mémoires embarquées volatiles tels que la SRAM et la DRAM occupent de plus en plus de surface silicium. C'est la raison pour laquelle une partie significative de la puissance totale consommée provient des composants mémoires. Ces deux dernières décennies, de nouvelles mémoires non volatiles sont apparues possédant des caractéristiques pouvant aider à résoudre les problèmes des SoCs actuels. Parmi elles, la MRAM est une candidate à fort potentiel car elle permet à la fois une forte densité d'intégration et une consommation d'énergie statique quasi nulle, tout en montrant des performances comparables à la SRAM et à la DRAM. De plus, la MRAM a la capacité d'être non volatile. Ceci est particulièrement intéressant pour l'ajout de nouvelles fonctionnalités afin d'améliorer l'efficacité énergétique ainsi que la fiabilité. Ce travail de thèse a permis de mener une exploration en surface, performance et consommation énergétique de l'intégration de la MRAM au sein de la hiérarchie mémoire d'un processeur. Une première exploration fine a été réalisée au niveau mémoire cache pour des architectures multicoeurs. Une seconde étude a permis d'évaluer la possibilité d'intégrer la MRAM au niveau registre pour la conception d'un processeur non volatile. Dans le cadre d'applications des objets connectés, de nouvelles fonctionnalités ainsi que les intérêts apportés par la non volatilité ont été étudiés et évalués. / With the downscaling of the complementary metal-oxide semiconductor (CMOS) technology,designing dense and energy-efficient systems-on-chip (SoC) is becoming a realchallenge. Concerning the density, reducing the CMOS transistor size faces up to manufacturingconstraints while the cost increases exponentially. Regarding the energy, a significantincrease of the power density and dissipation obstructs further improvement inperformance. This issue is mainly due to the growth of the leakage current of the CMOStransistors, which leads to an increase of the static energy consumption. Observing currentSoCs, more and more area is occupied by embedded volatile memories, such as staticrandom access memory (SRAM) and dynamic random access memory (DRAM). As a result,a significant proportion of total power is spent into memory systems. In the past twodecades, alternative memory technologies have emerged with attractive characteristics tomitigate the aforementioned issues. Among these technologies, magnetic random accessmemory (MRAM) is a promising candidate as it combines simultaneously high densityand very low static power consumption while its performance is competitive comparedto SRAM and DRAM. Moreover, MRAM is non-volatile. This capability, if present inembedded memories, has the potential to add new features to SoCs to enhance energyefficiency and reliability. In this thesis, an area, performance and energy exploration ofembedding the MRAM technology in the memory hierarchy of a processor architectureis investigated. A first fine-grain exploration was made at cache level for multi-core architectures.A second study evaluated the possibility to design a non-volatile processorintegrating MRAM at register level. Within the context of internet of things, new featuresand the benefits brought by the non-volatility were investigated.
386

Conservation and recreation of development and build environment for embedded systems

Heffsten, Andreas January 2019 (has links)
Today new technology is rapidly being developed, therefore it becomesdicult for developers to continue development and recreate builds ofsoftware written just a few years ago. Because of this, a quality attributeto make it easier for developers to recreate and continue development ofold systems is needed. The aim of this thesis is to dene what sustain-able system development is and develop a quality attribute for it. Thequality attribute is presented together with tactics, general scenarios andpatterns that can be used to implement the quality attribute on dierentsystems.This is to make it easier for developers to recreate and continuedevelopment of old systems.To dene sustainable system development a number of interviews weredone. These interviews were done with people that are developing soft-ware and with people that are working in the area of improving systemsreproducability. From these interviews sustainable system developmentwas concluded to be dened by how good reproducibility, testability, mod-iability and portability the system has.To prove that the concept for the quality attribute works, the qualityattribute was applied on the system for the ECU Coordinator 8 at Sca-nia. With the aim to implement sustainable system development on thatsystem. The implementation improved the reproducibility and testabilityof the system. But it didn't improve the modiability and portability,which means that the implementation at Scania can still be further im-proved. Some tests were performed where a developer at Scania triedto recreate the system after the implementation of the quality attribute.These tests were successful and an interview with the developer was doneafter the test, where the developer thought that the implementation hada positive eect on sustainable system development. From this the proofof concept for the quality attribute can be seen as successful.
387

Parametric solitons due to cubic nonlinearities

Kolossovski, Kazimir, Mathematics & Statistics, Australian Defence Force Academy, UNSW January 2001 (has links)
The main subject of this thesis is solitons due to degenerate parametric four-wave mixing. Derivation of the governing equations is carried out for both spatial solitons (slab waveguide) and temporal solitons (optical fibre). Higher-order effects that are ignored in the standard paraxial approximation are discussed and estimated. Detailed analysis of conventional solitons is carried out. This includes discovery of various solitons families, linear stability analysis of fundamental and higher-order solitons, development of theory describing nonlinear dynamics of higher-order solitons. The major findings related to the stationary problem are bifurcation of a two-frequency soliton family from an asymptotic family of infinitely separated one-frequency solitons, jump bifurcation and violation of the bound state principle. Linear stability analysis shows a rich variety of internal modes of the fundamental solitons and existence of a stability window for higher-order solitons. Theory for nonlinear dynamics of higher-order solitons successfully predicts the position and size of the stability window, and various instability scenarios. Equivalence between direct asymptotic approach and invariant based approach is demonstrated. A general analytic approach for description of localised solutions that are in resonance with linear waves (quasi-solitons and embedded solitons) is given. This includes normal form theory and approximation of interacting particles. The main results are an expression for the amplitude of the radiating tail of a quasi-soliton, and a two-fold criterion for existence of embedded solitons. Influence of nonparaxiality on soliton stability is investigated. Stationary instability threshold is derived. The major results are shift and decreasing of the size of the stability window for higher-order solitons. The latter is the first demonstration of the destabilizing influence of nonparaxiality on higher-order solitons. Analysis of different aspects of solitons is based on universal approaches and methods. This includes Hamiltonian formalism, consideration of symmetry properties of the model, development of asymptotic models, construction of perturbation theory, application of general theorems etc. Thus, the results obtained can be extended beyond the particular model of degenerate four-wave mixing. All theoretical predictions are in good agreement with the results of direct numerical modeling.
388

Realization of Dielectric Embedded Monopole Radiating Structures For Wireless Computing

Ireland, David John, n/a January 2006 (has links)
With the rapid of growth of wireless connectivity more demand is placed on the need for innovative technologies capable of satisfying increasing user demand and network capacity. Adaptive antennas systems or most commonly known as Smart Antennas are expected to be implemented in the next generation of wireless systems. Their implementation avails in dynamic adaptation to spatial and temporal conditions affecting the quality of communication, while offering tremendous flexibility to wireless providers. However one of the major challenges facing Smart Antenna technology is the inherent complexity of the antenna structure, associated control algorithm and implemented RF components possibly contributing to the delay of commercial interest. This thesis will present various adaptive antenna configurations that utilize an embedded dielectric in order to achieve significant size reduction and mechanical rigidity while maintaining favorable electromagnetic performance. In order to constrict the lateral ground plane dimension, a cylindrical shaped hollow ground skirt was attached to the antenna structures effectively compromising between effective beam forming in the azimuth plane and physical size. The complexity of these antenna structures requires a more contemporary design approach which involved computer modeling using a commercial available Finite Element software package and optimization using a developed generic Genetic Algorithm based optimization program. A dielectric embedded 7-element monopole array antenna featuring switched parasitic elements is presented and optimized for maximum vertically polarized gain in the horizontal plane, producing an antenna structure with a radial length of less then 0.25λ and total height of 0.4&alamba which was shown to radiate a main lobe beamwidth of 80 degrees with an absolute gain of 4.8dBi at 2.45GHz. Further on a dielectric embedded 7-element monopole array antenna featuring parasitic elements terminated with finite set of terminating reactive loads is presented with a radial length of less then 0.25&alambda and total height of 0.4&alambda. The antenna structure and reactive load combination were optimized for maximum horizontal gain producing a principal main lobe with a measured gain of 5.1dBi and beamwidth of 110 degrees at 2.48GHz. Finally it was shown single and dual radiation lobes maybe produced when active monopoles elements are placed eccentric in a circular shaped dielectric material. A circular array of elements embedded in a dielectric material was realized with measured gains of single and dual beam radiation at 2.45GHz was shown to be 5.18dBi and 3.65Bi respectively with corresponding beamwidths of 78.5 degrees and 53 degrees.
389

Solutions for emerging problems in modular system-on-a-chip testing

Xu, Qiang. Nicolici, Nicola. January 2005 (has links)
Thesis (Ph.D.)--McMaster University, 2005. / Supervisor: Nicola Nicolici. Includes bibliographical references (189-208 p.)
390

Implementing Memory Protection in a Minimal OS

Fagrell, Per, Eklycke, Richard January 2009 (has links)
<p>The car industry has created a series of standards called AutoSAR as a response to the increasing number of processors in modern vehicles. Among these specifications is one for real-time operating systems (RTOS). This RTOS standard includes requirements for memory protection. This thesis outlines the work involved in introducing the memory protection outlined in this specification in the OSEck operating system. The work consisted of updating the operating system, implementing the AutoSAR OS API, and updating the suite of toolsused to build the finished system.The AutoSAR specifications were found to be very thorough and well thoughtout. The OS API was successfully implemented, and the data-structures needed to permit its functionality. The existing software tools were updated to conformwith the new requirements from AutoSAR, and additional software was createdto ease the configuration process.Memory protection was successfully implemented in the OSEck operating system, including two implementations of the trap interface. The memory protection functionality adds yet another layer of user-configuration to the operating system. Also, additional overhead for system calls, context switches and message passing is expected. A general evaluation of how OSEck application performance is aff ected is beyond the scope of this thesis, but preliminary studies of additional instruction counts on certain system calls have been performed.</p>

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