Timed automata are a formalism to model, verify, and synthesize real-time systems. They have the advantage of having an abstract mathematical semantics, which allow formalizing and solving several verification and synthesis problems. However, timed automata are intended to design models, rather than completely describe real systems. Therefore, once the design phase is over, it remains to check whether the behavior of an actual implementation corresponds to that of the timed automaton model. An important step before implementing a system design is ensuring its robustness. This thesis considers a notion of robustness that asks whether the behavior of a given timed automaton is preserved, or can be made so, when it is subject to small perturbations. Several approaches are considered: Robustness analysis seeks to decide whether a given timed automaton tolerates perturbations, and in that case to compute the (maximum) amount of tolerated perturbations. In robust synthesis, a given system needs to be controlled by a law (or strategy) which tolerates perturbations upto some computable amount. In robust implementation, one seeks to automatically transform a given timed automaton model so that it tolerates perturbations by construction. Several perturbation models are considered, ranging from introducing error in time measures (guard enlargement), forbidding behaviors that are too close to boundaries (guard shrinking), and restricting the time domain to a discrete sampling. We also formalize robust synthesis problems as games, where the control law plays against the environment which can systematically perturb the chosen moves, by some bounded amount. These problems are studied on timed automata and their variants, namely, timed games, and weighted timed automata and games. Algorithms for the parameterized robustness analysis against guard enlargements, and guard shrinkings are presented. The robust synthesis problem is studied for two variants of the game semantics, for timed automata, games, and their weighted extensions. A software tool for robustness analysis against guard shrinkings is presented, and experimental results are discussed. The robust implementation problem is also studied in two different settings. In all algorithms, an upper bound on perturbations that the given timed automaton tolerates can be computed.

Increased reactive oxygen species (ROS) have been reported to be at the centre of various diseases. Although several reports have implicated elevated levels of ROS in the pathogenesis of diabetes mellitus, the early detection of ROS is still not attainable. This limitation causes difficulty in the early diagnosis of ROS related disorders. The presence of high levels of ROS was reported to result in differential expression of antioxidant genes involved in protecting cells from their deleterious effects. Among the antioxidant genes that are expressed, it was postulated that expression of metallothioneins (MTs) are also induced. MTs are low molecular weight, cysteine-rich proteins involved in metal homeostasis and reported to harbour antioxidant function. The aim of this investigation was to explore MTs as biomarkers for elevated levels of ROS in whole blood of type 2 diabetic (T2D) individuals. The level of ROS in diabetic, non-diabetic as well as individuals at risk of developing T2D was determined via the use of biochemical assays. Real-Time PCR was utilised to analyse the expression of MTs and the presence of MT proteins was analysed via the ELISA. In this study it was observed that diabetic individuals had elevated levels of ROS. However, no significant difference in the expression of MTs and the presence of MT proteins between the diabetic and non-diabetic individuals was observed. In vitro experimental conditions indicated that MT expression is induced by elevated levels of ROS. In pathological conditions the ROS-dependent induction of MT expression needs to be elucidated further. It therefore can be suggested that MTs can not yet be utilised as biomarkers for the detection of elevated levels of ROS in pathological conditions with ROS aetiology. This investigation also highlights the fact that blood is not an optimal medium in which this objective can be attained. / Thesis (Ph.D. (Biochemistry))--North-West University, Potchefstroom Campus, 2005.

Complexity and variety of systems that are working in real time mode need to be specified regarding all behavior conditions. The correctness of the specification, determines whether implemented system will supply conditions that were set. To ensure that specification of the described real-time system is correct, we have to do verification and validation of the specification. Traditional verification methods do not assure full real time system inspection. The main drawback, talking about them, is impossibility of system evaluation according time. In this paper a reachable states graph and its generating algorithms are described, while two time moments are compared using linear programming, Simplex method. Therefore, method for checking equivalent state in system behavioral pathway was suggested. Also, theoretical reasoning for creating computer applications, which automates generation of reachable states graph, is given. Reachable states graph fully evaluates real time system behavior.

The aim of this research is to create the modeling and simulation tool for the real time systems. The component based object oriented model of real time system is introduced as solution. This model uses JAVA and XML languages to specify one component of the real time system. The model can be used to generate source code directly from components specifications. The modeling and simulation system was created based on component model. It can be used for modeling real time systems of any domain, any abstraction level or any complexity level. The experiments show that proposed modeling technique is correct.

A real-time system is one in which the correctness of the computations not only depends upon the logical correctness of the computation but also upon the time at which the result is produced. If the timing constraints of the system are not met, system failure is said to have occurred. Real-time system consist specialized hardware an software components. Nowadays, systems are so big and complex that teams of architects, analysts, programmers, testers and users must work together to create reliable real-time system. To manage this, a number of system development life cycle models have been created. System development life cycle refers to a methodology for developing systems. It provides a consistent framework of tasks and deliverables needed to develop systems. System development consist stages, that are common for all models: project planning, requirements definition, system design, implementation, testing, deployment and maintenance. However, there still are problems, that lead project to the failure. Problems appear while iterating from design stage to the implementation or prototype creation. Thesis describes methodology, that provide a way to overcome these problems. The main idea is to transform functional structure of the real-time system, that is designed using easy to understand graphical environment, to the executable code that will be able to run on target hardware components. Thesis describe the methods of doing such transformation. Methodology allows to create... [to full text]

Šio darbo tikslas suprojektuoti ir sukurti nesudėtingą garsinio signalo apdorojimo realiu laiku įtaisą, populiaraus „Arduino“ mikrovaldiklio pagrindu, kuriuo būtų lengva naudotis ir būtų galimybė pagrindines funkcijas valdyti naudojantis TC/IP protokolu. „Arduino“ mikrovaldiklis pasirinktas dėl jo populiarumo, prieinamos kainos ir dėl gausios informacijos, apie jo panaudojimo galimybes. Be abejo yra daug ir kitų platformų skirtų įvairių prietaisų kūrimui su pakankamai išsamia informacija, bet „Arduino“ platformai yra sukurta nemokama atviro kodo programinė įranga, „Arduino“ kontrolerio programavimui tiesiogiai iš personalinio kompiuterio, nenaudojant papildomų priemonių, dirbanti su Windows ir Unix operacinėmis sistemomis. / Most modern desktop computers are equipped with audio hardware. This hardware allows audio to be recorded as digital information for storage and later playback. This digital information can be manipulated to change how the audio sounds when played back. But if we don’t have a computer, or just need to get some sound effects quickly without recording audio? Maybe You are a student who are learning sound processing hardware and need some examples of audio synthesis? Do you like an “Arduino” and want to see what it can? This device is for You! This small device based on “Arduino” controller makes audio processing in real time, producing some audio effects and also it can play some synthetic sound. In this device is integrated LCD screen, where you can see some information about what the device is doing, when you have pressed one of some buttons on it. Also it is possible to manage the device over the internet. You need just plug in an Ethernet cable, open an internet browser on the computer in local network and add an IP address of this device. You will get small web page where you will found few buttons. By clicking with mouse on these buttons you can listen to a synthetic sound, which system can produce. In this work You will be introduced to the sound signal processing. You will also find graphs and flowchart detailing the sequence of event between the user and system, the exchange of data inside and the static structure of the system in the architectural specification. In... [to full text]

This document is a master’s thesis analyzing an automated fuel pump management system. In the first chapters we take a general overview of the system and the main problems that we will be facing during the planning and design phases of the project. Later we propose and analyze possible solutions for these problems. Technical system information is revealed in the later chapters. Functional and non functional requirements are discussed along with the main UML diagrams. The research phase of the thesis provides detailed system analysis and software quality reports which later are used to create proposed changes to the system. These changes are analyzed, designed and coded in the final - experimental part of the thesis. The main proposal is to convert the system architecture from flow driven to event driven. This change helps to solve several uncovered architectural problems as well as improve the general quality of the system. These changes are tested and analyzed in the experimental chapter of the thesis and finally the conclusions are made. The main conclusion is that the proposed architectural changes were chosen correctly. This is also supported by the experimental data.

Gausybė sudėtingų realaus laiko sistemų turi būti specifikuotos įvertinant visas galimas situacijas. Specifikacijos teisingumas reiškia, kad sistema užduotomis sąlygomis pasieks norimą rezultatą. Norėdami užtikrinti, kad aprašyta specifikacija yra teisinga, reikia atlikti sistemos verifikavimą ir validavimą. Tradiciniai verifikavimo metodai neužtikrina pilno sistemos patikrinimo. Pagrindinis jų trūkumas yra tai, kad jos negali įvertinti laikinių charakteristikų. Per keletą paskutinių metų, buvo sukurti nauji metodai, kuriuose įvykių įvykimo laikas priklauso intervalams. Šiame darbe šie metodai buvo patobulinti, kad pilnai aprašytų realaus laiko sistemų veiksenas. Šiame darbe pateikiamas pasiekiamų būsenų medžio sudarymo algoritmas, kai sistemos pabaigos laikų momentų aibė priklauso bet kokiam intervalui - griežtam, negriežtam, griežtam iš kairės arba dešinės. / Complexity and variety of systems that are working in real time mode need to be specified regarding all behavior conditions. The correctness of the specification, determines whether implemented system will supply conditions that were set. To ensure that specification of the described real-time system is correct, we have to do verification and validation of the specification. Traditional verification methods do not assure full real time system inspection. The main drawback, talking about them, is impossibility of system evaluation according time. In past few years, new methods were implemented, whereat real time system events befall in time interval. In this paper, these methods were improved to fully specify real time systems behaviour. Reachable states graph and its generating algorithms are described here, wherein real time system events befall in any type of time interval – inclusive, exclusive in left, right or both sides.

The Iterative Closest Point (ICP) algorithm is one of the most commonly used range image processing methods. However, slow operational speeds and high input band-widths limit the use of ICP in high-speed real-time applications. This thesis presents and examines a novel hardware implementation of a high-speed ICP object tracking system that uses stereo vision disparities as input. Although software ICP trackers already exist, this innovative hardware tracker utilizes the efficiencies of custom hardware processing, thus enabling faster high-speed real-time tracking. A custom hardware design has been implemented in an FPGA to handle the inherent bottlenecks that result from the large input and processing band-widths of the range data. The hardware ICP design consists of four stages: Pre-filter, Transform, Nearest Neighbor, and Transform Recovery. This custom hardware has been implemented and tested on various objects, using both software simulation and hardware tests. Results indicate that the tracker is able to successfully track free-form objects at over 200 frames-per-second along arbitrary paths. Tracking errors are low, in spite of substantial noisy stereo input. The tracker is able to track stationary paths within 0.42mm and 1.42degs, linear paths within 1.57mm and 2.80degs, and rotational paths within 0.39degs axis error. With further degraded data by occlusion, the tracker is able to handle 60% occlusion before a slow decline in performance. The high-speed hardware implementation (that uses 16 parallel nearest neighbor circuits), is more then five times faster than the software K-D tree implementation. This tracker has been designed as the hardware component of ‘FastTrack’, a high frame rate, stereo vision tracking system, that will provide a known object’s pose in real-time at 200 frames per second. This hardware ICP tracker is compact, lightweight, has low power requirements, and is integratable with the stereo sensor and stereo extraction components of the FastTrack’ system on a single FPGA platform. High-speed object tracking is useful for many innovative applications, including advanced spaced-based robotics. Because of this project’s success, the ‘FastTrack’ system will be able to aid in performing in-orbit, automated, remote satellite recovery for maintenance. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-07-15 22:50:30.369

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