This dissertation shows that with simple programming abstractions, network-wide resource coordination is efficient and useful for programming embedded sensor networks. Existing systems have focused primarily on managing resources for individual nodes, but a sensor network is not merely a collection of nodes operating independently: it must coordinate behavior across multiple nodes to achieve high efficiency. We need tools that can enable system-wide coordination at a higher level of abstraction than what exists today. We present three core contributions. The first is a service called IDEA that enables networkwide energy management for sensor networks. It unites energy monitoring, load modeling, and distributed state sharing into a single service that facilitates distributed decision making. Using simulation and testbed results, we show that IDEA enables improvements in network lifetime of up to 35% over approaches that do not consider energy distribution. Our second contribution is Karma, a system for coordinating insect-sized robotic microaerial vehicle (MAV) swarms, an emerging class of mobile sensor networks. Karmas system architecture simplifies the functionality of an individual MAV to a sequence of sensing and actuation commands called behaviors. Each behavior has an associated progress function, a measure of how much of that behavior has been completed. Programming is done by composing behaviors which are coordinated using input from the progress functions. Through simulation and testbed experiments, we demonstrate Karma applications can run on limited resources, are robust to individual MAV failure, and adapt to changes in the environment. Our final contribution is Simbeeotic, a testbed for MAV coordination algorithms. MAV sensors must be codesigned with the software and coordination algorithms that depend on them. This requires a testbed capable of simulating sensors to evaluate them before actual hardware is available and the ability to test with real flight dynamics for accurate control evaluation. In addition, simulation should be able to scale to hundreds or thousands of MAVs at a reduced level of fidelity in order to test at scale. We demonstrate that Simbeeotic provides the appropriate level of fidelity to evaluate prototype systems while maintaining the ability to test at scale. / Engineering and Applied Sciences

MP3, or MPEG-1 Layer 3, is the most widely-used format for storing compressed audio. MP3 is more advantageous than uncompressed audio (PCM), offering a much smaller size but without a noticeable loss in audio quality. This report will demonstrate decoding and playback of MP3 audio using a TLL5000 FPGA board. / text

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

Το πρότυπο IEC61499 ορίζει το Function Block ως νέο τρόπο ανάπτυξης συστημάτων ελέγχου και αυτοματισμού. Τα συστήματα αυτά αποτελούνται από κατανεμημένες, ενσωματωμένες συσκευές οι οποίες διασυνδέονται μέσω βιομηχανικών δικτύων πραγματικού χρόνου. Λόγω του κατανεμημένου χαρακτήρα των συστημάτων αυτών, η εύρεση και επιδιόρθωση σφαλμάτων και ο έλεγχος της ορθής λειτουργίας τους θα πρέπει να γίνεται στο περιβάλλον των ενσωματωμένων αυτών συστημάτων. Στα πλαίσια αυτής της διπλωματικής δίνεται μία υλοποίηση για την κάλυψη της παραπάνω ανάγκης. Ο χρήστης μέσω μίας γραφικής διεπαφής, έχει την δυνατότητα να εκτελεί βασικές λειτουργίες απασφαλμάτωσης στο περιβάλλον των ενσωματωμένων συστημάτων, σε πραγματικό χρόνο, με την χρήση του RTAI και του RTnet. / The IEC 61499 standard defines Function Block as a new way of developing control and automation systems. These systems consist of distributed embedded devices which interconnect via real time industrial networks. Due to the distributive character of these systems, debugging and operation integrity check, should be done on target environment. This dissertation provides a tool for covering this need. Via a graphical user interface the user has the ability to perform basic real time debugging operations in the target enviroment, using RTAI and RTnet.

In order to maximize operating time of an industrial machine and minimize stand-by time, service time and operating costs, a diagnostic system can be a useful tool. Diagnostic systems employ information already available in a machine’s control system (such as control signals, system state, sensor readings and so forth) to perform intelligent fault detection and localisation, and predict future faults and service needs. CC Systems develops advanced electronics and control systems for industrial machines and vehicles operating in rough environments. One of their products is a diagnostic platform called Diagnostic Runtime Engine (DRE), supplying the customer with a tool for building a diagnostic system. The platform offers supervision of the control system. Actions are performed when it detects a possible fault or indication of a potential future fault. An action could be for example the creation of an alarm. The DRE, as designed today, only works together with a control system running in an environment called CoDeSys. In this master thesis a new architecture of the platform is presented, with the objective to make the platform compatible with an arbitrary control system. A prototype is implemented to prove the concept of the suggested architecture model. A number of different standard diagnostic blocks, used for building the diagnostic system, are also suggested with the objective to make it easier for the user to employ the DRE. A proposition of how development with the diagnostic platform can proceed beyond this thesis is also presented. / För att maximera drifttid hos en industriell maskin och minimera driftskostnader samt standby- och service-tid, kan ett diagnostiksystem användas. Ett sådant system använder sig av information som redan finns tillgänglig i maskinens styrsystem (så som styrsignaler, tillstånd, sensorvärden och så vidare) för att utföra feldetektering och fellokalisering samt analys av möjliga framtida feltillstånd och servicebehov. CC Systems utvecklar avancerade elektronikkomponenter och styrsystem för industriella maskiner och fordon. En av deras produkter är en diagnostikplattform, Diagnostic Runtime Engine (DRE), som erbjuder ett verktyg för att bygga upp ett diagnostiksystem. Plattformen möjliggör övervakning av styrsystemet, och detektion av ett nuvarande feltillstånd eller möjligt framtida feltillstånd leder till att en handling utförs. En handling kan till exempel vara att ett alarm skapas. Diagnostikplattformen, som den är gjord idag, fungerar bara tillsammans med ett styrsystem som är implementerat i utvecklingsmiljön CoDeSys. I detta examensarbete presenteras en ny arkitektur på plattformen som möjliggör användande tillsammans med ett godtyckligt styrsystem. En prototyp är implementerad för att visa att den föreslagna arkitekturmodellen fungerar i praktiken. Dessutom är ett antal standard-diagnostikblock, som används då ett diagnostiksystem byggs upp, föreslagna. Standardblocken har till syfte att underlätta användandet av diagnostikplattformen. Ett förslag för hur DRE kan byggas om och utvecklas i framtiden är också presenterat.

The IMAPCAR2 from Renesas Electronics is an embedded realtime image processor, combining a single core with a 128-way SIMD array. At runtime, sections of the SIMD array can be retasked as additional CPU cores, interconnected via a message passing ring. Using these cores effectively, however, is made difficult by the low-level nature of the message passing API and the lack of cache coherency between processors. Developing and debugging software for this platform is a difficult task. The AutoPilot library addresses this by providing a high-level message-oriented parallel programming model for the IMAPCAR2. AutoPilot's API is closely based on that of Pilot, a wrapper around the Message Passing Interface (MPI) for cluster computing. By reimplementing the Pilot API for the IMAPCAR2, AutoPilot shows that its processes-and-channels architecture is a viable choice for parallel programming on cache-incoherent multicore architectures. At the same time, it provides a simpler API for programmers, with builtin safety checks that eliminate some common sources of errors.

In the state of Texas, instruction in the arts is required from Kindergarten through eighth grade. In many cases, the responsibility for teaching these subjects falls on the classroom elementary teacher despite limited knowledge, experience, and a low sense of self efficacy. This study examined how an online professional development program affected elementary teachers’ use of arts approaches, the attitudes and issues that have a bearing on the use of arts approaches, and teacher learning that occurred as a result of engaging in an online professional development program. An embedded mixed methods design was used that embedded a qualitative case study within a quantitative study in order to compare and corroborate the quantitative findings. Participants, employed at an elementary campus in South Texas, consisted of seven elementary generalist teachers who participated in an eight week online professional development program and six teachers who volunteered to complete a survey only. The central question, “how does an online job-embedded professional development program affect elementary teachers’ beliefs about and use of arts integrated approaches to learning,” guided the study. Seven sources of both quantitative and qualitative data were collected over a ten week period. Themes that emerged from the qualitative data analysis were student outcomes, teacher-efficacy, and external factors. Findings indicate that (1) online formats are a viable form of professional development, (2) a lack of time to plan most significantly impacts the use of arts approaches, and (3) improved access to rich, arts based lesson resources may increase the use of arts in the classroom. This study was significant because it provided insight into the quality of teacher learning and its impact on classroom practice as the result of online professional development.

Traditional models of professional development for teachers are often characterized by formats intended to transmit information for transfer to classroom practice. But it can be argued that one-size-fits-all models do not adequately meet the professional needs of teachers or respect the view of teachers as learners (Hall & Loucks, 1978; Stigler & Hiebert, 1999). More recently, school districts have explored job-embedded approaches to professional development. However, little or no program evaluation has been utilized to gather evidence of their value to practitioners (Guskey, 2000). This study examined the perceived transformative value of an alternate professional development (PD) experience on teacher practice. The study aimed to: 1. Describe teachers' conceptualizations of "teacher practice". 2. Describe the ways teachers perceive their professional development experiences as having impacted their teaching practice. 3. Report teachers' perceptions of effective and ineffective professional development. 4. Identify institutional practices that influence teachers' perceptions of meaningful professional development. 5. Describe the intrinsic and extrinsic factors valued by teachers in a professional development experience. Qualitative research methodology was utilized for this case study. I invited participants from the District Literacy Committee (DLC) to participate in this research, and conducted a cross-case analysis to analyze the experiences of Practicing Teachers (PTs) and Observing Teachers (OTs). My data collection included web-based surveys, artifacts, and two focus group discussions. Results indicated a strong perception that the job-embedded lesson study model had significant impact on teaching practice. My analysis of the data analysis elicited many similarities and some key differences between the two groups. While the OT and PT were similar in their conceptions of effective and ineffective PD, they differed in their conception of teacher practice and what they valued in a PD experience. Both groups believed PD had tremendous potential to impact teaching behaviours. The findings suggest that differentiated learning opportunities are necessary to meet the needs of teachers, and that alternative models of PD such as lesson study deserve consideration. This study has significant implications for those who facilitate PD and those who develop it. / Thesis (Master, Education) -- Queen's University, 2009-04-24 21:26:10.355

Navigation algorithms integrating measurements from multi-sensor systems overcome the problems that arise from using GPS navigation systems in standalone mode. Algorithms which integrate the data from 2D low-cost reduced inertial sensor system, consisting of a gyroscope and an odometer, along with a GPS via a Kalman filter has proved to be worthy in providing a consistent and more reliable navigation solution compared to the standalone GPS. It has been also shown to be beneficial, especially in GPS-denied environments such as urban canyons and tunnels. The main objective of this research is to narrow the idea-to-implementation gap that follows the algorithm development by realizing a low-cost real-time embedded navigation system that is capable of computing the data-fused positioning solution instantly. The role of the developed system is to synchronize the measurements from the three sensors, GPS, gyroscope and odometer, relative to the pulse per second signal generated from the GPS, after which the navigation algorithm is applied to the synchronized measurements to compute the navigation solution in real-time. Xilinx’s MicroBlaze soft-core processor on a Virtex-4 FPGA is utilized and customized for developing the real-time navigation system. The soft-core processor offers the flexibility to choose or implement a set of features and peripherals that are tailored to the specific application to be developed. An embedded system design model is chosen to act as a framework for the work flow to be carried through the system life cycle starting from the system specification phase and ending with the system release. The developed navigation system is tested first on a mobile robot to reveal system bugs and integration problems, and then on a land vehicle testing platform for further testing. The real-time solution from the implemented system when compared to the solution of a high-end navigation system, proved to be successful in providing a comparable consistent real-time navigation solution. Employing a soft-core processor in the kernel of the navigation system, provided the flexibility for communicating with the various sensors and the computation capability required by the Kalman filter integration algorithm. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-10-11 16:08:38.811

Steganography is classified as the art of hiding information. In a digital context, this refers to our ability to hide secret messages within innocent digital cover data. The digital domain offers many opportunities for possible cover mediums, such as cloud based hiding (saving secret information within the internet and its structure), image based hiding, video and audio based hiding, text based documents as well as the potential of hiding within any set of compressed data. This dissertation focuses on the image based domain and investigates currently available image based steganographic techniques. After a review of the history of the field, and a detailed survey of currently available JPEG based steganographic systems, the thesis focuses on the systems currently considered to be secure and introduces mechanisms that have been developed to detect them. The dissertation presents a newly developed system that is designed to counter act the current weakness in the YASS JPEG based steganographic system. By introducing two new levels of randomization to the embedding process, the proposed system offers security benefits over YASS. The introduction of randomization to the B‐block sizes as well as the E‐block sizes used in the embedding process aids in increasing security and the potential for new, larger E‐block sizes also aids in providing an increased set of candidate coefficients to be used for embedding. The dissertation also introduces a new embedding scheme which focuses on hiding in medium frequency coefficients. By hiding in these medium frequency coefficients, we allow for more aggressive embedding without risking more visual distortion but trade this off with a risk of higher error rates due to compression losses. Finally, the dissertation presents simulation aimed at testing the proposed system performance compared to other JPEG based steganographic systems with similar embedding properties. We show that the new system achieves an embedding capacity of 1.6, which represents round a 7 times improvement over YASS. We also show that the new system, although introducing more bits in error per B‐block, successfully allows for the embedding of up to 2 bits per B‐block more than YASS at a similar error rate per B‐block. We conclude the results by demonstrating the new systems ability to resist detection both through human observation, via a survey, as well as resist computer aided analysis. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2010.