231 research outputs found

    Acta Cybernetica : Volume 25. Number 2.

    Get PDF

    Contribution to the development of microwave remote sensing for UAV systems.

    Get PDF
    Microwave technology is very sensitive to Radio Frequency Interferences (RFI). Works previously done within this Master by Marc Jou [1] showed the impossibility to retrieve measurements using L-band radiometers on-board drones. After detecting such issue, Balamis first tried to solve it by hardware: a new antenna design and the extensive use of shielding on the drone were tried without success. Balamis started the development of its first digital radiometer based on the use of Software Defined Radio architecture on 2017, partially funded with the support of CDTI. The resulting minimum viable digital radiometer was ready by June 2019, but it did not include any RFI mitigation capability. Developments done my Master student Ahmad Daoud [2] demonstrated the identification of RFI using Fast Fourier Transform (FFT) over RAW data but could not provide any efficient implementation of its mitigation on-board the L-band radiometer. The proposed solution is the implementation of the FFT and the RFI filters using Field Programmable Gate of Array (FPGA) for the input signals, and its concurrent performance. Filtering an analog signal by introducing in-system FFT of ZYNQ7000 FPGA is implemented in this project. Additionally, the power consumption of FPGA, and the need to dissipate it, forces the development of a temperature control system with cooling capabilities. It is done to improve the previous heating-only thermal control of Balamis radiometer. Such more advanced thermal control will be also used for the Interferometric Ground-based Synthetic Aperture Radar that Balamis is developing. Solving these two goals are therefore the purpose of this Master Thesis

    A Multi-layer Fpga Framework Supporting Autonomous Runtime Partial Reconfiguration

    Get PDF
    Partial reconfiguration is a unique capability provided by several Field Programmable Gate Array (FPGA) vendors recently, which involves altering part of the programmed design within an SRAM-based FPGA at run-time. In this dissertation, a Multilayer Runtime Reconfiguration Architecture (MRRA) is developed, evaluated, and refined for Autonomous Runtime Partial Reconfiguration of FPGA devices. Under the proposed MRRA paradigm, FPGA configurations can be manipulated at runtime using on-chip resources. Operations are partitioned into Logic, Translation, and Reconfiguration layers along with a standardized set of Application Programming Interfaces (APIs). At each level, resource details are encapsulated and managed for efficiency and portability during operation. An MRRA mapping theory is developed to link the general logic function and area allocation information to the device related physical configuration level data by using mathematical data structure and physical constraints. In certain scenarios, configuration bit stream data can be read and modified directly for fast operations, relying on the use of similar logic functions and common interconnection resources for communication. A corresponding logic control flow is also developed to make the entire process autonomous. Several prototype MRRA systems are developed on a Xilinx Virtex II Pro platform. The Virtex II Pro on-chip PowerPC core and block RAM are employed to manage control operations while multiple physical interfaces establish and supplement autonomous reconfiguration capabilities. Area, speed and power optimization techniques are developed based on the developed Xilinx prototype. Evaluations and analysis of these prototype and techniques are performed on a number of benchmark and hashing algorithm case studies. The results indicate that based on a variety of test benches, up to 70% reduction in the resource utilization, up to 50% improvement in power consumption, and up to 10 times increase in run-time performance are achieved using the developed architecture and approaches compared with Xilinx baseline reconfiguration flow. Finally, a Genetic Algorithm (GA) for a FPGA fault tolerance case study is evaluated as a ultimate high-level application running on this architecture. It demonstrated that this is a hardware and software infrastructure that enables an FPGA to dynamically reconfigure itself efficiently under the control of a soft microprocessor core that is instantiated within the FPGA fabric. Such a system contributes to the observed benefits of intelligent control, fast reconfiguration, and low overhead

    Multi-resource management in embedded real-time systems

    Get PDF
    This thesis addresses the problem of online multi-resource management in embedded real-time systems. It focuses on three research questions. The first question concentrates on how to design an efficient hierarchical scheduling framework for supporting independent development and analysis of component based systems, to provide temporal isolation between components. The second question investigates how to change the mapping of resources to tasks and components during run-time efficiently and predictably, and how to analyze the latency of such a system mode change in systems comprised of several scalable components. The third question deals with the scheduling and analysis of a set of parallel-tasks with real-time constraints which require simultaneous access to several different resources. For providing temporal isolation we chose a reservation-based approach. We first focused on processor reservations, where timed events play an important role. Common examples are task deadlines, periodic release of tasks, budget replenishment and budget depletion. Efficient timer management is therefore essential. We investigated the overheads in traditional timer management techniques and presented a mechanism called Relative Timed Event Queues (RELTEQ), which provides an expressive set of primitives at a low processor and memory overhead. We then leveraged RELTEQ to create an efficient, modular and extensible design for enhancing a real-time operating system with periodic tasks, polling, idling periodic and deferrable servers, and a two-level fixed-priority Hierarchical Scheduling Framework (HSF). The HSF design provides temporal isolation and supports independent development of components by separating the global and local scheduling, and allowing each server to define a dedicated scheduler. Furthermore, the design addresses the system overheads inherent to an HSF and prevents undesirable interference between components. It limits the interference of inactive servers on the system level by means of wakeup events and a combination of inactive server queues with a stopwatch queue. Our implementation is modular and requires only a few modifications of the underlying operating system. We then investigated scalable components operating in a memory-constrained system. We first showed how to reduce the memory requirements in a streaming multimedia application, based on a particular priority assignment of the different components along the processing chain. Then we investigated adapting the resource provisions to tasks during runtime, referred to as mode changes. We presented a novel mode change protocol called Swift Mode Changes, which relies on Fixed Priority with Deferred preemption Scheduling to reduce the mode change latency bound compared to existing protocols based on Fixed Priority Preemptive Scheduling. We then presented a new partitioned parallel-task scheduling algorithm called Parallel-SRP (PSRP), which generalizes MSRP for multiprocessors, and the corresponding schedulability analysis for the problem of multi-resource scheduling of parallel tasks with real-time constraints. We showed that the algorithm is deadlock-free, derived a maximum bound on blocking, and used this bound as a basis for a schedulability test. We then demonstrated how PSRP can exploit the inherent parallelism of a platform comprised of multiple heterogeneous resources. Finally, we presented Grasp, which is a visualization toolset aiming to provide insight into the behavior of complex real-time systems. Its flexible plugin infrastructure allows for easy extension with custom visualization and analysis techniques for automatic trace verification. Its capabilities include the visualization of hierarchical multiprocessor systems, including partitioned and global multiprocessor scheduling with migrating tasks and jobs, communication between jobs via shared memory and message passing, and hierarchical scheduling in combination with multiprocessor scheduling. For tracing distributed systems with asynchronous local clocks Grasp also supports the synchronization of traces from different processors during the visualization and analysis

    An examination of the Asus WL-HDD 2.5 as a nepenthes malware collector

    No full text
    The Linksys WRT54g has been used as a host for network forensics tools for instance Snort for a long period of time. Whilst large corporations are already utilising network forensic tools, this paper demonstrates that it is quite feasible for a non-security specialist to track and capture malicious network traffic. This paper introduces the Asus Wireless Hard disk as a replacement for the popular Linksys WRT54g. Firstly, the Linksys router will be introduced detailing some of the research that was undertaken on the device over the years amongst the security community. It then briefly discusses malicious software and the impact this may have for a home user. The paper then outlines the trivial steps in setting up Nepenthes 0.1.7 (a malware collector) for the Asus WL-HDD 2.5 according to the Nepenthes and tests the feasibility of running the malware collector on the selected device. The paper then concludes on discussing the limitations of the device when attempting to execute Nepenthes

    Intensional Cyberforensics

    Get PDF
    This work focuses on the application of intensional logic to cyberforensic analysis and its benefits and difficulties are compared with the finite-state-automata approach. This work extends the use of the intensional programming paradigm to the modeling and implementation of a cyberforensics investigation process with backtracing of event reconstruction, in which evidence is modeled by multidimensional hierarchical contexts, and proofs or disproofs of claims are undertaken in an eductive manner of evaluation. This approach is a practical, context-aware improvement over the finite state automata (FSA) approach we have seen in previous work. As a base implementation language model, we use in this approach a new dialect of the Lucid programming language, called Forensic Lucid, and we focus on defining hierarchical contexts based on intensional logic for the distributed evaluation of cyberforensic expressions. We also augment the work with credibility factors surrounding digital evidence and witness accounts, which have not been previously modeled. The Forensic Lucid programming language, used for this intensional cyberforensic analysis, formally presented through its syntax and operational semantics. In large part, the language is based on its predecessor and codecessor Lucid dialects, such as GIPL, Indexical Lucid, Lucx, Objective Lucid, and JOOIP bound by the underlying intensional programming paradigm.Comment: 412 pages, 94 figures, 18 tables, 19 algorithms and listings; PhD thesis; v2 corrects some typos and refs; also available on Spectrum at http://spectrum.library.concordia.ca/977460

    An Abstraction Framework for Tangible Interactive Surfaces

    Get PDF
    This cumulative dissertation discusses - by the example of four subsequent publications - the various layers of a tangible interaction framework, which has been developed in conjunction with an electronic musical instrument with a tabletop tangible user interface. Based on the experiences that have been collected during the design and implementation of that particular musical application, this research mainly concentrates on the definition of a general-purpose abstraction model for the encapsulation of physical interface components that are commonly employed in the context of an interactive surface environment. Along with a detailed description of the underlying abstraction model, this dissertation also describes an actual implementation in the form of a detailed protocol syntax, which constitutes the common element of a distributed architecture for the construction of surface-based tangible user interfaces. The initial implementation of the presented abstraction model within an actual application toolkit is comprised of the TUIO protocol and the related computer-vision based object and multi-touch tracking software reacTIVision, along with its principal application within the Reactable synthesizer. The dissertation concludes with an evaluation and extension of the initial TUIO model, by presenting TUIO2 - a next generation abstraction model designed for a more comprehensive range of tangible interaction platforms and related application scenarios

    Secure portable execution and storage environments: A capability to improve security for remote working

    Get PDF
    Remote working is a practice that provides economic benefits to both the employing organisation and the individual. However, evidence suggests that organisations implementing remote working have limited appreciation of the security risks, particularly those impacting upon the confidentiality and integrity of information and also on the integrity and availability of the remote worker’s computing environment. Other research suggests that an organisation that does appreciate these risks may veto remote working, resulting in a loss of economic benefits. With the implementation of high speed broadband, remote working is forecast to grow and therefore it is appropriate that improved approaches to managing security risks are researched. This research explores the use of secure portable execution and storage environments (secure PESEs) to improve information security for the remote work categories of telework, and mobile and deployed working. This thesis with publication makes an original contribution to improving remote work information security through the development of a body of knowledge (consisting of design models and design instantiations) and the assertion of a nascent design theory. The research was conducted using design science research (DSR), a paradigm where the research philosophies are grounded in design and construction. Following an assessment of both the remote work information security issues and threats, and preparation of a set of functional requirements, a secure PESE concept was defined. The concept is represented by a set of attributes that encompass the security properties of preserving the confidentiality, integrity and availability of the computing environment and data. A computing environment that conforms to the concept is considered to be a secure PESE, the implementation of which consists of a highly portable device utilising secure storage and an up-loadable (on to a PC) secure execution environment. The secure storage and execution environment combine to address the information security risks in the remote work location. A research gap was identified as no existing ‘secure PESE like’ device fully conformed to the concept, enabling a research problem and objectives to be defined. Novel secure storage and execution environments were developed and used to construct a secure PESE suitable for commercial remote work and a high assurance secure PESE suitable for security critical remote work. The commercial secure PESE was trialled with an existing telework team looking to improve security and the high assurance secure PESE was trialled within an organisation that had previously vetoed remote working due to the sensitivity of the data it processed. An evaluation of the research findings found that the objectives had been satisfied. Using DSR evaluation frameworks it was determined that the body of knowledge had improved an area of study with sufficient evidence generated to assert a nascent design theory for secure PESEs. The thesis highlights the limitations of the research while opportunities for future work are also identified. This thesis presents ten published papers coupled with additional doctoral research (that was not published) which postulates the research argument that ‘secure PESEs can be used to manage information security risks within the remote work environment’

    A Resilient System Design to Boot a RISC-V MPSoC

    Get PDF
    This paper presents a highly resilient boot process design for Ballast, a new RISC- V based multiprocessor system-on-chip (SoC). An open source RISC- V SoC was adapted as a bootstrap processor and customized to meet our requirement for guaranteed chip wake-up. We outline the characteristic challenges of implementing a large program into a read-only memory (ROM) used for booting and propose generally applica-ble workflows to verify the boot process for application specific integrated circuit (ASIC) synthesis. We implemented four distinct boot modes. Two modes that load a software bootloader autonomously from an SD card are implemented for a secure digital input output (SDIO) interface and for a serial peripheral interface (SPI), respectively. Another SDIO based mode allows for direct program execution from external memory, while the last mode is based on usage of a RISC- V debug module. The boot process was verified with instruction set simulation, register transfer level simulation, gate-level simulation and field-programmable gate array prototyping. We received the fabricated ASIC samples and were able to successfully boot the chip via all boot modes on our custom circuit board.Peer reviewe
    • …
    corecore