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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

Built-in tests for a real-time embedded system.

Olander, Peter Andrew. January 1991 (has links)
Beneath the facade of the applications code of a well-designed real-time embedded system lies intrinsic firmware that facilitates a fast and effective means of detecting and diagnosing inevitable hardware failures. These failures can encumber the availability of a system, and, consequently, an identification of the source of the malfunction is needed. It is shown that the number of possible origins of all manner of failures is immense. As a result, fault models are contrived to encompass prevalent hardware faults. Furthermore, the complexity is reduced by determining syndromes for particular circuitry and applying test vectors at a functional block level. Testing phases and philosophies together with standardisation policies are defined to ensure the compliance of system designers to the underlying principles of evaluating system integrity. The three testing phases of power-on self tests at system start up, on-line health monitoring and off-line diagnostics are designed to ensure that the inherent test firmware remains inconspicuous during normal applications. The prominence of the code is, however, apparent on the detection or diagnosis of a hardware failure. The authenticity of the theoretical models, standardisation policies and built-in test philosophies are illustrated by means of their application to an intricate real-time system. The architecture and the software design implementing the idealogies are described extensively. Standardisation policies, enhanced by the proposition of generic tests for common core components, are advocated at all hierarchical levels. The presentation of the integration of the hardware and software are aimed at portraying the moderately complex nature of the task of generating a set of built-in tests for a real-time embedded system. In spite of generic policies, the intricacies of the architecture are found to have a direct influence on software design decisions. It is thus concluded that the diagnostic objectives of the user requirements specification be lucidly expressed by both operational and maintenance personnel for all testing phases. Disparity may exist between the system designer and the end user in the understanding of the requirements specification defining the objectives of the diagnosis. It is thus essential for complete collaboration between the two parties throughout the development life cycle, but especially during the preliminary design phase. Thereafter, the designer would be able to decide on the sophistication of the system testing capabilities. / Thesis (M.Sc.)-University of Natal, Durban, 1991.
162

QUIC-TCP: validation of QUIC-TCP through network simulations

Unknown Date (has links)
The scalability of QUIC-TCP was examined by expanding previous developmental 11-node, 4-flow topology to over 30 nodes with 11 flows to validate QUIC-TCP for larger networks. The topology was simulated using ns-2 network simulator with the same ns-2 module of FAST-TCP modified to produce QUIC-TCP agent that the original development used. A symmetrical topology and a random topology were examined. Fairness, aggregate throughput and the object of the utility function were used as validation criteria. It was shown through simulation that QUICTCP optimized the utility function and demonstrated a good balance between aggregate throughput and fairness; therefore QUIC-TCP is indeed scalable to larger networks. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.
163

Design of an Aquatic Quadcopter with Optical Wireless Communications

Unknown Date (has links)
With a focus on dynamics and control, an aquatic quadcopter with optical wireless communications is modeled, designed, constructed, and tested. Optical transmitter and receiver circuitry is designed and discussed. By utilization of the small angle assumption, the nonlinear dynamics of quadcopter movement are linearized around an equilibrium state of zero motion. The set of equations are then tentatively employed beyond limit of the small angle assumption, as this work represents an initial explorative study. Specific constraints are enforced on the thrust output of all four rotors to reduce the multiple-input multiple-output quadcopter dynamics to a set of single-input single-output systems. Root locus and step response plots are used to analyze the roll and pitch rotations of the quadcopter. Ultimately a proportional integral derivative based control system is designed to control the pitch and roll. The vehicle’s yaw rate is similarly studied to develop a proportional controller. The prototype is then implemented via an I2C network of Arduino microcontrollers and supporting hardware. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2016. / FAU Electronic Theses and Dissertations Collection
164

An asynchronous forth microprocessor.

January 2000 (has links)
Ping-Ki Tsang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 87-95). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation and Aims --- p.1 / Chapter 1.2 --- Contributions --- p.3 / Chapter 1.3 --- Overview of the Thesis --- p.4 / Chapter 2 --- Asynchronous Logic g --- p.6 / Chapter 2.1 --- Motivation --- p.6 / Chapter 2.2 --- Timing Models --- p.9 / Chapter 2.2.1 --- Fundamental-Mode Model --- p.9 / Chapter 2.2.2 --- Delay-Insensitive Model --- p.10 / Chapter 2.2.3 --- QDI and Speed-Independent Models --- p.11 / Chapter 2.3 --- Asynchronous Signalling Protocols --- p.12 / Chapter 2.3.1 --- 2-phase Handshaking Protocol --- p.12 / Chapter 2.3.2 --- 4-phase Handshaking Protocol --- p.13 / Chapter 2.4 --- Data Representations --- p.14 / Chapter 2.4.1 --- Dual Rail Coded Data --- p.15 / Chapter 2.4.2 --- Bundled Data --- p.15 / Chapter 2.5 --- Previous Asynchronous Processors --- p.16 / Chapter 2.6 --- Summary --- p.20 / Chapter 3 --- The MSL16 Architecture --- p.21 / Chapter 3.1 --- RISC Machines --- p.21 / Chapter 3.2 --- Stack Machines --- p.23 / Chapter 3.3 --- Forth and its Applications --- p.24 / Chapter 3.4 --- MSL16 --- p.26 / Chapter 3.4.1 --- Architecture --- p.28 / Chapter 3.4.2 --- Instruction Set --- p.30 / Chapter 3.4.3 --- The Datapath --- p.32 / Chapter 3.4.4 --- Interrupts and Exceptions --- p.33 / Chapter 3.4.5 --- Implementing Forth primitives --- p.34 / Chapter 3.4.6 --- Code Density Estimation --- p.34 / Chapter 3.5 --- Summary --- p.35 / Chapter 4 --- Design Methodology --- p.37 / Chapter 4.1 --- Basic Notation --- p.38 / Chapter 4.2 --- Specification of MSL16A --- p.39 / Chapter 4.3 --- Decomposition into Concurrent Processes --- p.41 / Chapter 4.4 --- Separation of Control and Datapath --- p.45 / Chapter 4.5 --- Handshaking Expansion --- p.45 / Chapter 4.5.1 --- 4-Phase Handshaking Protocol --- p.46 / Chapter 4.6 --- Production-rule Expansion --- p.47 / Chapter 4.7 --- Summary --- p.48 / Chapter 5 --- Implementation --- p.49 / Chapter 5.1 --- C-element --- p.49 / Chapter 5.2 --- Mutual Exclusion Elements --- p.51 / Chapter 5.3 --- Caltech Asynchronous Synthesis Tools --- p.53 / Chapter 5.4 --- Stack Design --- p.54 / Chapter 5.4.1 --- Eager Stack Control --- p.55 / Chapter 5.4.2 --- Lazy Stack Control --- p.56 / Chapter 5.4.3 --- Eager/Lazy Stack Datapath --- p.53 / Chapter 5.4.4 --- Pointer Stack Control --- p.61 / Chapter 5.4.5 --- Pointer Stack Datapath --- p.62 / Chapter 5.5 --- ALU Design --- p.62 / Chapter 5.5.1 --- The Addition Operation --- p.63 / Chapter 5.5.2 --- Zero-Checker --- p.64 / Chapter 5.6 --- Memory Interface and Tri-state Buffers --- p.64 / Chapter 5.7 --- MSL16A --- p.65 / Chapter 5.8 --- Summary --- p.66 / Chapter 6 --- Results --- p.67 / Chapter 6.1 --- FPGA based implementation of MSL16 --- p.67 / Chapter 6.2 --- MSL16A --- p.69 / Chapter 6.2.1 --- A Comparison of 3 Stack Designs --- p.69 / Chapter 6.2.2 --- Evaluation of the ALU --- p.73 / Chapter 6.2.3 --- Evaluation of MSL16A --- p.74 / Chapter 6.3 --- Summary --- p.81 / Chapter 7 --- Conclusions --- p.83 / Chapter 7.1 --- Future Work --- p.85 / Bibliography --- p.87 / Publications --- p.95
165

Forced simulation : a formal approach to component based development of embedded systems

Roop, Parthasarathi, Computer Science & Engineering, Faculty of Engineering, UNSW January 2000 (has links)
Application specific digital systems, called embedded systems, touch almost every aspect of modern human life. As a result, there is considerable interest in automating the design (called synthesis) of these systems. Further, given the time-to-market pressures and increasing system complexities, component reuse during synthesis is being touted as a key to success. This thesis proposes a formal framework for reusing system-level components during synthesis. Within the framework for component reuse, component matching is a key problem that must be addressed. Given the specification of a design function, and a device stored as a component in a library, component matching addresses the question of whether the device can implement the function. Often system-level components are multi-functional and generic, and it is rarely the case that the function is directly realizable by a device. Hence, an important aspect of matching is to decide whether the device can be dynamically adapted to match the function. This thesis proposes a formalization of the matching problem using formal models of the function and device, denoted by F and D respectively. D matches F provided there exists an interface I that adapts D dynamically to produce the same behaviour as F. None of the existing implementation verification techniques within formal methods can be used to test for the existence of an I between arbitrary pairs of F and D. In this thesis, a new simulation relation called forced simulation is proposed between the states of F and D. It is then formally established that the existence of a forced simulation relation is a necessary and sufficient condition for the existence of I for a pair of F and d. Two kinds of forced simulation are proposed, one each for synchronous and asynchronous interactions with the environment. Based on forced simulation, a polynomial time algorithm for automatic matching of F and D is also developed. The distinguishing feature of the algorithm is that when successful, it generates an interface that automatically adapts the device to behave like the function. The algorithm is illustrated by reusing two rogrammable components from Intel and some typical embedded controllers.
166

Scheduling and Optimisation of Heterogeneous Time/Event-Triggered Distributed Embedded Systems

Pop, Traian January 2003 (has links)
<p>Day by day, we are witnessing a considerable increase in number and range of applications which entail the use of embedded computer systems. This increase is closely followed by the growth in complexity of applications controlled by embedded systems, often involving strict timing requirements, like in the case of safety-critical applications. Efficient design of such complex systems requires powerful and accurate tools that support the designer from the early phases of the design process.</p><p>This thesis focuses on the study of real-time distributed embedded systems and, in particular, we concentrate on a certain aspect of their real-time behavior and implementation: the time-triggered (TT) and event-triggered (ET) nature of the applications and of the communication protocols. Over the years, TT and ET systems have been usually considered independently, assuming that an application was entirely ET or TT. However, nowadays, the growing complexity of current applications has generated the need for intermixing TT and ET functionality. Such a development has led us to the identification of several interesting problems that are approached in this thesis. First, we focus on the elaboration of a holistic schedulability analysis for heterogeneous TT/ET task sets which interact according to a communication protocol based on both static and dynamic messages. Second, we use the holistic schedulability analysis in order to guide decisions during the design process. We propose a design optimisation heuristic that partitions the task-set and the messages into the TT and ET domains, maps and schedules the partitioned functionality, and optimises the communication protocol parameters. Experiments have been carried out in order to measure the efficiency of the proposed techniques.</p> / Report code: LiU-Tek-Lic-2003:21.
167

Reliable and secure data transport in large scale wireless networks of embedded devices

Naik, Vinayak Shashikant, January 2006 (has links)
Thesis (Ph. D.)--Ohio State University, 2006. / Title from first page of PDF file. Includes bibliographical references (p. 105-111).
168

A Platform-Centric UML-/XML-Enhanced HW/SW Codesign Method for the Development of SoC Systems

Arpnikanondt, Chonlameth 11 April 2004 (has links)
As today's real-time embedded systems grow increasingly ubiquitous, rising complexity ensues as more and more functionalities are integrated. Market dynamics and competitiveness further constrict the technology-to-market time requirement, consequently pushing it to the very forefront of consideration during the development process. Traditional system development approaches could no longer efficiently cope with such formidable demands, and a paradigm shift has been perceived by many as a mandate. This thesis presents a novel platform-centric SoC design method that relies on a platform-based design to expedite the overall development process. The proposed approach offers a new perspective towards the complex systems design paradigm, and can attain the desired paradigm shift through extensive reuse and flexibility. It offers a unified communication means for all sectors involved in the development process: Semiconductor vendors can use it to publish their platform specifications; Tool vendors can use it to develop and/or enhance their tools; System developers can use it to efficiently develop the system. Key technologies are also identified, namely the Extensible Markup Language (XML) and the Unified Modeling Language (UML), that realize the proposed approach. This thesis extends XML to attain a standard means for modeling, and processing a large amount of reusable platform-related data. Additionally, it employs UML's own extension mechanism to derive a UML dialect that can be used to model real-time systems and characteristics. This UML dialect, i.e. the UML profile for Codesign Modeling Framework (UML-CMF), remains compliant to the UML standard. A sub-profile within the UML profile for Codesign Modeling Framework is also developed so as to furnish a means for efficient modeling of platforms, and that can be seamlessly integrated with other real-time modeling capabilities offered by the UML-CMF. Such an effort yields a robust UML-compliant language that is suitable for a general platform-based modeling and design. A practical use of the proposed approach is demonstrated through a powerful case study that applies the approach to develop a digital camera system. The results are comparatively presented against the SpecC approach in terms of cost metrics based on the COCOMO II model.
169

SiGe BiCMOS circuit and system design and characterization for extreme environment applications

England, Troy Daniel 07 July 2011 (has links)
This thesis describes the architecture, verification, qualification, and packaging of a 16-channel silicon-germanium (SiGe) Remote Electronics Unit (REU) designed for use in extreme environment applications encountered on NASA's exploration roadmap. The SiGe REU was targeted for operation outside the protective electronic "vaults" in a lunar environment that exhibits cyclic temperature swings from -180ºC to 120ºC, a total ionizing dose (TID) radiation level of 100 krad, and heavy ion exposure (single event effects) over the mission lifetime. The REU leverages SiGe BiCMOS technological advantages and design methodologies, enabling exceptional extreme environment robustness. It utilizes a mixed-signal Remote Sensor Interface (RSI) ASIC and an HDL-based Remote Digital Control (RDC) architecture to read data from up to 16 sensors using three different analog channel types with customizable gain, current stimulus, calibration, and sample rate with 12-bit analog-to-digital conversion. The SiGe REU exhibits excellent channel sensitivity throughout the temperature range, hardness to at least 100 krad TID exposure, and single event latchup immunity, representing the cutting edge in cold-capable electronic systems. The SiGe REU is the first example within a potential paradigm shift in space-based electronics.
170

Strategien für die Instruktionscodekompression in cachebasierten, eingebetteten Systemen /

Jachalsky, Jörn. January 1900 (has links)
Thesis--Technische Universität Hannover. / Includes bibliographical references.

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