H Ενοποιημένη Γλώσσα Μοντελοποίησης (Unified Modeling Language) αποτελεί την πρότυπη και πλέον δημοφιλή γλώσσα για την οπτικοποίηση, προσδιορισμό, ανάπτυξη και τεκμηρίωση συστημάτων λογισμικού και όχι μόνο. Η πλούσια γραφική σημειολογία της UML σε συνδυασμό με τις δυνατότητες μοντελοποίησης που παρέχει, την καθιστούν ικανή να χρησιμοποιηθεί στην ανάπτυξη ενσωματωμένων συστημάτων. Ωστόσο, στα ενσωματωμένα συστήματα, αλλά και γενικότερα σε συστήματα συγκεκριμένου πεδίου υπάρχουν κάποιοι επιπλέον παράγοντες που πρέπει να ληφθούν υπόψη. Οι επεκτάσεις της UML δίνουν τη δυνατότητα αναπαράστασης των βασικών χαρακτηριστικών των ενσωματωμένων συστημάτων. Επιπλέον, παρέχουν νέες μεθόδους σχεδιασμού που επιτρέπουν τον διαμερισμό εφαρμογής και αρχιτεκτονικής, για ένα πιο αποδοτικό και επαναχρησιμοποιήσιμο σύστημα. Στην παρούσα εργασία μελετώνται τα βασικά στοιχεία της UML καθώς και η χρήση της στην ανάπτυξη ενσωματωμένων συστημάτων. Στη συνέχεια, χρησιμοποιώντας τη UML μοντελοποιείται και αναπτύσσεται η εφαρμογή ελέγχου ενός συστήματος γραμμής παραγωγής, του Festo MPS. Επιπλέον, αναπτύσσεται και υλοποιείται εφαρμογή εξομοίωσης του φυσικού συστήματος Festo MPS για την επιβεβαίωση της σωστής λειτουργίας της εφαρμογής ελέγχου. / The Unified Modeling Language (UML) constitutes the most popular standardized language for visualizing, specifying and documenting all the artefacts of a software system. Its rich graphical notation, in combination with the modelling facilities it provides, makes it possible for UML to be used in the development of embedded systems. However, in embedded system design, as well as in specific domain problems, there are some additional factors that should be taken into consideration. The extensions of UML provide the opportunity for representing the basic features of embedded systems. In addition, these extensions provide new design methods which allow the separation of the application from the architecture, leading to a more efficient and reusable system. At this thesis the basic elements of UML as well as its use in the development of embedded systems are studied. Moreover, using UML, the control application of a linear production system, Festo MPS is modelled and developed. Finally, a simulator application of the physical system Festo MPS is developed, in order to verify that the constructed control application works properly.

DUE TO COPYRIGHT-RESTRICTIONS THIS PAPER IS NOT AVAILABLE FOR DOWNLOAD! The thesis describes a system which communicates in real time with data loggers. The system has been streamlined and integrated with existing application so that each user can get a graphical presentation in real time on what has been sent to and from the units. The user interface and communication has been designed to be robust, user friendly, secure and offer functionality that yields the users of the system added value. The system is flexible from the design perspective and is low maintenance.

The purpose of this study was to explore the syntactic, semantic, and structural features of infinitival small clauses. The analysis of the small clauses was conducted on the basis of the evidence drawn from the novel “A Farewell to Arms” by Ernest Hemingway. The methods used in the study were descriptive-inductive and statistical analysis. The research showed that the author of the novel used infinitival small clauses to replace a variety of reduced clauses. They included reduced objective clauses, adverbial clauses of purpose, result, condition, and reduced relative clauses. The study demonstrated that reduced objective clauses replaced by infinitival small clauses had the highest frequency of occurrence. The research also revealed that Ernest Hemingway predominantly used infinitival small clauses with infinitives after verbs in comparison to infinitival small clause following other parts of speech. / Šis darbas nagrinėja redukuotus predikatinius sakinius su bendratimi Ernesto Hemingvėjaus romane „Atsisveikinimas su ginklais“. Tyrimo tikslai buvo šie: 1) išanalizuoti sintaksinius redukuotų predikatinių sakinių su bendratimi tipus; 2) išanalizuoti semantinius bei struktūrinius redukuotų predikatinių sakinių su bendratimi bruožus; 3) ištirti redukuotų predikatinių sakinių su bendratimi dažnumą romane. Redukuoti predikatiniai sakiniai E. Hemingvėjaus romane buvo nagrinėjami, remiantis aprašomuoju-indukciniu ir statistinės analizės metodais. Tyrimas parodė, kad autorius vartojo mažiausiai šešis sintaksinius redukuotų predikatinių sakinių su bendratimi tipus: 1) Redukuotus šalutinius papildinio sakinius; 2) Redukuotus šalutinius tikslo sakinius; 3) Redukuotus šalutinius rezultato sakinius; 4) Redukuotus šalutinius sąlygos sakinius; 5) Redukuotus šalutinius pažyminio sakinius; 6) Kai kurių kitų tipų redukuotus šalutinius sakinius (laiko, priežasties, palyginimo). Tyrimo metu paaiškėjo, kad redukuoti predikatiniai sakiniai daugiausia kilo iš šalutinių papildinio sakinių: jie sudarė 48.16% visų redukuotų predikatinių sakinių su bendratimi. Rečiau buvo vartojami redukuoti šalutiniai tikslo sakiniai (24.63%) bei redukuoti šalutiniai pažyminio sakiniai (12.25%). Redukuoti šalutiniai rezultato sakiniai sudarė 8.70%, redukuoti šalutiniai sąlygos sakiniai – 3.55%, o kai kurių kitų tipų redukuoti šalutiniai sakiniai tesudarė 2.70%. Bendratis buvo pavartota su veiksmažodžiais (73.90%)... [toliau žr. visą tekstą]

The present thesis is part of an approach that attempts to represent the quasi-brittle behavior of heterogeneous materials such as cementitious ones. The guideline followed fits in a sequenced multi-scale framework for which descriptions of the material are selected at a thin scale (mesoscopic or microscopic) and information is transferred to a larger scale (macroscopic). It shows how the explicit representation of heterogeneities offers interesting prospects on identification, understanding and modeling of macroscopic behaviors. In practice, from a simple description of each phases and interfaces behavior, a structural effect that leads to more complex macroscopic behavior is observed. This work is therefore focusing on two main axes. On the one hand, the morphological representation of the heterogeneities is handle using the excursion sets theory. Randomly shaped inclusions, which geometrical and topological characteristics are analytically controlled, are produced by applying a threshold on realizations of correlated Random Fields. On the other hand, the FE implementation of both heterogeneity and local degradation behavior (micro-cracking) are dealt with by a double kinematics enhancement (weak and strong discontinuity) using the Embedded Finite Element Method. Finally, combining both axes of the problematic, the resulting model is tested by modeling cementitious materials at the meso-scale under uniaxial loadings mainly. It reveals an emergent macroscopic response that exhibits several features such as asymmetry of the tension-compression stress-strain relationship, crack patterns or historical-dependency, which are typical of concrete-like materials.

FPGAs are increasingly used to implement embedded digital systems because of their low time-to-market and low costs compared to integrated circuit design, as well as their superior performance and area over a general purpose microprocessor. However, the hardware design necessary to achieve this superior performance and area is very difficult to perform causing long design times and preventing wide-spread adoption of FPGA technology. The amount of hardware design can be reduced by employing a microprocessor for less-critical computation in the system. Often this microprocessor is implemented using the FPGA reprogrammable fabric as a soft processor which can preserve the benefits of a single-chip FPGA solution without specializing the device with dedicated hard processors. Current soft processors have simple architectures that provide performance adequate for only the least-critical computations. Our goal is to improve soft processors by scaling their performance and expanding their suitability to more critical computation. To this end we focus on the data parallelism found in many embedded applications and propose that soft processors be augmented with vector extensions to exploit this parallelism. We support this proposal through experimentation with a parameterized soft vector processor called VESPA (Vector Extended Soft Processor Architecture) which is designed, implemented, and evaluated on real FPGA hardware. The scalability of VESPA combined with several other architectural parameters can be used to finely span a large design space and derive a custom architecture for exactly matching the needs of an application. Such customization is a key advantage for soft processors since their architectures can be easily reconfigured by the end-user. Specifically, customizations can be made to the pipeline, functional units, and memory system within VESPA. In addition, general purpose overheads can be automatically eliminated from VESPA. Comparing VESPA to manual hardware design, we observe a 13x speed advantage for hardware over our fastest VESPA, though this is significantly less than the 500x speed advantage over scalar soft processors. The performance-per-area of VESPA is also observed to be significantly higher than a scalar soft processor suggesting that the addition of vector extensions makes more efficient use of silicon area for data parallel workloads.

Uranium (U) exhibits a high temperature body-centered cubic (bcc) allotrope that is often stabilized by alloying with transition metals such as Zr, Mo, and Nb for technological applications. One such application involves U–Zr as nuclear fuel, where radiation damage and diffusion (processes heavily dependent on point defects) are of vital importance. Metallic nuclear fuels swell under fission conditions, creating fission product gases such as helium, xenon and krypton. Several systems of U are examined within a density functional theory framework utilizing projector augmented wave pseudopotentials. The bulk modulus, the lattice constant, and the Birch–Murnaghan equation of state for the defect free bcc uranium allotrope are calculated. Defect parameters calculated include energies of formation of vacancies in the α and γ allotropes, as well as self-interstitials, Zr, He, Xe and Kr interstitial and substitutional defects. This work is utilized in the construction of modified Embedded-Atom Method interatomic potentials for the bcc phase of uranium as well as the binary systems of U-Xe, U-Kr and U-He. Using this potential, equilibrium volume and elastic constants are calculated at 0 K and found to be in close agreement with previous first principles calculations. Further, the melting point, heat capacity, enthalpy of fusion, thermal expansion and volume change upon melting are calculated and found to be in reasonable agreement with experiment. Calculations of dilute fission gas defects show reasonable agreement with first principles calculations. Finally, void and xenon bubble energetics are analyzed as a function of temperature.

The CanX-4 and CanX-5 mission currently under development at The University of Toronto Institute for Aerospace Studies Space Flight Laboratory UTIAS/SFL is a challenging formation flying technology demonstration. Its requirements of sub-metre control accuracy have yet to be realized with nanosatellites. Many large technical challenges must be addressed in order to ensure the success of the CanX-4/5 mission. This includes the development of software for an intersatellite communication system, integration and optimization of key formation flying algorithms onto the Payload On-Board Computer as well as the development of a Hardware-In-The-Loop simulator for full on-orbit mission simulations. This thesis will provide background knowledge of the Space Flight Laboratory and its activities, the CanX-4/5 mission, and nally highlight the authors contributions to overcoming each of these technical challenges and ensuring the success of the CanX-4 and CanX-5 mission.

In modern times, human life is intrinsically depending on real-time embedded systems (RTES) with increasingly safety-critical and mission-critical features, for instance, in domains such as automotive and avionics. These systems are characterized by stringent functional requirements and require predictable timing behavior. However, the complexity of RTES has been ever increasing requiring systematic development methods. To address these concerns, model-based frameworks and component-based design methodologies have emerged as a feasible solution. Further, system artifacts such as requirements/specifications, architectural designs as well as behavioral models like statemachine views are integrated within the development process. However, several challenges remain to be addressed, out of which two are especially important: expressiveness, to represent the real-time and causality behavior, and analyzability, to support verification of functional and timing behavior. As the main research contribution, this thesis presents design and verification techniques for model-based development of RTES, addressing expressiveness and analyzability for architectural and behavioral models. To begin with, we have proposed a systematic design process to support component-based development. Next, we have provided a real-time semantic basis, in order to support expressiveness and verification for structural and behavioral models. This is achieved by defining an intuitive formal semantics for real-time component models, using ProCom, a component model developed at our research centre, and also using the CCSL (Clock Constraint Specification Language), an expressive language for specification of timed causality behavior. This paves the way for formal verification of both architectural and behavioral models, using model checking, as we show in this work, by transforming the models into timed automata and performing verification using UPPAAL, a model checking tool based on timed automata. Finally, the research contributions are validated using representative examples of RTES as well as an industrial case-study. / ARROWS

Today's embedded distributed real-time systems, are exposed to large variations in resource usage due to complex software applications, sophisticated hardware platforms, and the impact of their run-time environment. As eciency becomes more important, the applications running on these systems are extended with on-line resource managers whose job is to adapt the system in the face of such variations. Distributed systems are often heterogeneous, meaning that the hardware platform consists of computing nodes with dierent performance, operating systems, and scheduling policies, linked through one or more networks using dierent protocols. In this thesis we explore whether resource managers used in such distributed embedded systems are stable, meaning that the system's resource usage is controlled under all possible run-time scenarios. Stability implies a bounded worst-case behavior of the system and can be linked with classic real-time systems' properties such as bounded response times for the software applications. In the case of distributed systems, the stability problem is particularly hard because software applications distributed over the dierent resources generate complex, cyclic dependencies between the resources, that need to be taken into account. In this thesis we develop a detailed mathematical model of an adaptive, distributed real-time system and we derive conditions that, if satised, guarantee its stability.

This thesis introduces new efficient hardware implementations for the Advanced Encryption Standard (AES) algorithm. Two main contributions are presented in this thesis, the first one is a high speed 128 bits AES encryptor, and the second one is a new 32 bits AES design. In first contribution a 128 bits loop unrolled sub-pipelined AES encryptor is presented. In this encryptor an efficient merging for the encryption process sub-steps is implemented after relocating them. The second contribution presents a 32 bits AES design. In this design, the S-BOX is implemented with internal pipelining and it is shared between the main round and the key expansion units. Also, the key expansion unit is implemented to work on the fly and in parallel with the main round unit. These designs have achieved higher FPGA (Throughput/Area) efficiency comparing to previous AES designs.