The development of electronic commerce systems is subject to different conditions than that of conventional software systems. This includes the introduction of new activities to the development process and the removal of others. An adapted process must cope with important idiosyncrasies of EC system development: EC systems typically have a high degree of interaction, which makes factors like ergonomics, didactics and psychology especially important in the development of user interfaces. Typically, they also have a high degree of integration with existing software systems such as legacy or groupware systems. Integration techniques have to be selected systematically in order not to endanger the whole software development process. This article describes the development of an EC system and it generalizes salient features of the software process used. The result is a process model that can be used for other highly integrative EC system development projects. The processes described are determined by short process lifecycles, by an orientation towards integration of legacy systems and by a strict role-based cooperation approach.

Nesta tese explora-se um conjunto de requisitos especiais de concepção e desenvolvimento de software que asseguram um alto grau de flexibilidade e eficiência para o controle de sistemas produtivos. Desenvolve-se assim, um método que inclui a técnica de degeneração (redução gradual do nível de serviços de um sistema) no projeto do software de controle de sistemas produtivos. Apresentam-se inicialmente os conceitos fundamentais considerados no projeto do software de sistemas de controle como: sistemas produtivos, sistemas de controle, sistemas distribuídos, arquitetura em n-camadas (“middleware") e sistemas multi-agentes. A seguir, introduz-se a aplicação de requisitos padrões para o desenvolvimento do software de controle com qualidade e com a característica de orientação a objetos. O trabalho apresenta também exemplos específicos relacionados com o controle em Edifícios Inteligentes adotados como estudo de casos, que ilustram a aplicação do método desenvolvido. Os respectivos artefatos resultantes da aplicação de cada etapa do método também são descritos e comprovam o potencial desta abordagem. / This thesis explores a set of special requirements for software development that assure high degree of flexibility and efficiency for control of productive systems. Thus, it investigates a method that includes the degeneration technique (i.e., a gradual reduction of the service level of a system) in the development of control software for productive systems. The text presents initially the basic concepts considered in the development of control software such as productive systems, distributed control systems, middleware architecture and multi-agent systems. Following, it introduces the application of standard requests for the development of control software with quality and object orientation features. The work also presents specific examples related with the control in Intelligent Buildings which have been adopted as case study and that illustrate the application of the proposed method. The artifacts generated from the application of each step of the method are also described and confirm the potential of the proposed approach.

Nesta tese explora-se um conjunto de requisitos especiais de concepção e desenvolvimento de software que asseguram um alto grau de flexibilidade e eficiência para o controle de sistemas produtivos. Desenvolve-se assim, um método que inclui a técnica de degeneração (redução gradual do nível de serviços de um sistema) no projeto do software de controle de sistemas produtivos. Apresentam-se inicialmente os conceitos fundamentais considerados no projeto do software de sistemas de controle como: sistemas produtivos, sistemas de controle, sistemas distribuídos, arquitetura em n-camadas (“middleware”) e sistemas multi-agentes. A seguir, introduz-se a aplicação de requisitos padrões para o desenvolvimento do software de controle com qualidade e com a característica de orientação a objetos. O trabalho apresenta também exemplos específicos relacionados com o controle em Edifícios Inteligentes adotados como estudo de casos, que ilustram a aplicação do método desenvolvido. Os respectivos artefatos resultantes da aplicação de cada etapa do método também são descritos e comprovam o potencial desta abordagem. / This thesis explores a set of special requirements for software development that assure high degree of flexibility and efficiency for control of productive systems. Thus, it investigates a method that includes the degeneration technique (i.e., a gradual reduction of the service level of a system) in the development of control software for productive systems. The text presents initially the basic concepts considered in the development of control software such as productive systems, distributed control systems, middleware architecture and multi-agent systems. Following, it introduces the application of standard requests for the development of control software with quality and object orientation features. The work also presents specific examples related with the control in Intelligent Buildings which have been adopted as case study and that illustrate the application of the proposed method. The artifacts generated from the application of each step of the method are also described and confirm the potential of the proposed approach.

Battery energy management plays a crucial role in fuel economy improvement of charge-sustaining parallel hybrid electric vehicles. Currently available control strategies consider battery state of charge (SOC) and driver’s request through the pedal input in decision-making. This method does not achieve an optimal performance for saving fuel or maintaining appropriate SOC level, especially during the operation in extreme driving conditions or hilly terrain. The objective of this thesis is to develop a control algorithm using forthcoming traffic condition and road elevation, which could be fed from navigation systems. This would enable the controller to predict potential of regenerative charging to capture cost-free energy and intentionally depleting battery energy to assist an engine at high power demand. The starting point for this research is the modelling of a small sport-utility vehicle by the analysis of the vehicles currently available in the market. The result of the analysis is used in order to establish a generic mild hybrid powertrain model, which is subsequently examined to compare the performance of controllers. A baseline is established with a conventional powertrain equipped with a spark ignition direct injection engine and a continuously variable transmission. Hybridisation of this vehicle with an integrated starter alternator and a traditional rule-based control strategy is presented. Parameter optimisation in four standard driving cycles is explained, followed by a detailed energy flow analysis. An additional potential improvement is presented by dynamic programming (DP), which shows a benefit of a predictive control. Based on these results, a predictive control algorithm using fuzzy logic is introduced. The main tools of the controller design are the DP, adaptive-network-based fuzzy inference system with subtractive clustering and design of experiment. Using a quasi-static backward simulation model, the performance of the controller is compared with the result from the instantaneous control and the DP. The focus is fuel saving and SOC control at the end of journeys, especially in aggressive driving conditions and a hilly road. The controller shows a good potential to improve fuel economy and tight SOC control in long journey and hilly terrain. Fuel economy improvement and SOC correction are close to the optimal solution by the DP, especially in long trips on steep road where there is a large gap between the baseline controller and the DP. However, there is little benefit in short trips and flat road. It is caused by the low improvement margin of the mild hybrid powertrain and the limited future journey information. To provide a further step to implementation, a software-in-the-loop simulation model is developed. A fully dynamic model of the powertrain and the control algorithm are implemented in AMESim-Simulink co-simulation environment. This shows small deterioration of the control performance by driver’s pedal action, powertrain dynamics and limited computational precision on the controller performance.

Memory corruption attacks have existed in C and C++ for more than 30 years, and over the years many defenses have been proposed. In addition to that, a new class of attacks, Spectre, has emerged that abuse speculative execution to leak secrets and sensitive data through micro-architectural side channels. Many defenses have been proposed to mitigate Spectre as well. However, with every new defense a new attack emerges, and then a new defense is proposed. This is an ongoing cycle between attackers and defenders. There exists many defenses for many different attack avenues. However, many suffer from either practicality or effectiveness issues, and security researchers need to balance out their compromises. Recently, many hardware vendors, such as Intel and ARM, have realized the extent of the issue of memory corruption attacks and have developed hardware security mechanisms that can be utilized to defend against these attacks. ARM, in particular, has released a mechanism called Pointer Authentication in which its main intended use is to protect the integrity of pointers by generating a Pointer Authentication Code (PAC) using a cryptographic hash function, as a Message Authentication Code (MAC), and placing it on the top unused bits of a 64-bit pointer. Placing the PAC on the top unused bits of the pointer changes its semantics and the pointer cannot be used unless it is properly authenticated. Hardware security features such as PAC are merely mechanisms not full fledged defences, and their effectiveness and practicality depends on how they are being utililzed. Naive use of these defenses doesn't alleviate the issues that exist in many state-of-the-art software defenses. The design of the defense that utilizes these hardware security features needs to have practicality and effectiveness in mind. Having both practicality and effectiveness is now a possible reality with these new hardware security features. This dissertation describes utilizing hardware security features, namely ARM PAC, to build effective and practical defense mechanisms. This dissertation first describes my past work called PACTight, a PAC based defense mechanism that defends against control-flow hijack- ing attacks. PACTight defines three security properties of a pointer such that, if achieved, prevent pointers from being tampered with. They are: 1) unforgeability: A pointer p should always point to its legitimate object; 2) non-copyability: A pointer p can only be used when it is at its specific legitimate location; 3) non-dangling: A pointer p cannot be used after it has been freed. PACTight tightly seals pointers and guarantees that a sealed pointer cannot be forged, copied, or dangling. PACTight protects all sensitive pointers, which are code pointers and pointers that point to code pointers. This completely prevents control-flow hijacking attacks, all while having low performance overhead. In addition to that, this dissertation proposes Scope-Type Integrity (STI), a new defense policy that enforces pointers to conform to the programmer's intended manner, by utilizing scope, type, and permission information. STI collects information offline about the type, scope, and permission (read/write) of every pointer in the program. This information can then be used at runtime to ensure that pointers comply with their intended purpose. This allows STI to defeat advanced pointer attacks since these attacks typically violate either the scope, type, or permission. We present Runtime Scope-Type Integrity (RSTI). RSTI leverages ARM Pointer Authentication (PA) to generate Pointer Authentication Codes (PACs), based on the information from STI, and place these PACs at the top bits of the pointer. At runtime, the PACs are then checked to ensure pointer usage complies with STI. RSTI overcomes two drawbacks that were present in PACTight: 1) PACTight relied on a large external metadata for protection, whereas RSTI uses very little metadata. 2) PACTight only protected a subset of pointers, whereas RSTI protects all pointers in a program. RSTI has large coverage with relatively low overhead. Also, this dissertation proposes sPACtre, a new and novel defense mechanism that aims to prevent Spectre control-flow attacks on existing hardware. sPACtre is an ARM-based defense mechanism that prevents Spectre control-flow attacks by relying on ARM's Pointer Authentication hardware security feature, annotations added to the program on the secrets that need to be protected from leakage and a dynamic tag-based bounds checking mechanism for arrays. We show that sPACtre can defend against these attacks. We evaluate sPACtre on a variety of cryptographic libraries with several cryptographic algorithms, as well as a synthetic benchmark, and show that it is efficient and has low performance overhead Finally, this dissertation explains a new direction for utilizing hardware security features to protect energy harvesting devices from checkpoint-recovery errors and malicious attackers. / Doctor of Philosophy / In recent years, cyber-threats against computer systems have become more and more preva- lent. In spite of many recent advancements in defenses, these attacks are becoming more threatening. However, many of these defenses are not implemented in the real-world. This is due to their high performance overhead. This limited efficiency is not acceptable in the real-world. In addition to that, many of these defenses have limited coverage and do not cover a wide variety of attacks. This makes the performance tradeoff even less convincing. Thus, there is a need for effective and practical defenses that can cover a wide variety of attacks. This dissertation first provides a comprehensive overview of the current state-of-the-art and most dangerous attacks. More specifically, three types of attacks are examined. First, control-flow hijacking attacks, which are attacks that divert the proper execution of a pro- gram to a malicious execution. Second, data oriented attacks. These are attacks that leak sensitive data in a program. Third, Spectre attacks, which are attacks that rely on sup- posedly hidden processor features to leak sensitive data. These "hidden" features are not entirely hidden. This dissertation explains these attacks in detail and the corresponding state-of-the-art defenses that have been proposed by the security research community to mitigate them. This dissertation then discusses effective and practical defense mechanisms that can mitigate these attacks. The dissertation discusses past work, PACTight, as well as its contributions, RSTI and sPACtre, presenting the full design, threat model, implementation, security eval- uation and performance evaluation of each one of these mechanisms. The dissertation relies on insights derived from the nature of the attack and compiler techniques. A compiler is a tool that transforms human-written code into machine code that is understandable by the computer. The compiler can be modified and used to make programs more secure with compiler techniques. The past work, PACTight, is a defense mechanism that defends against the first type of attacks, control-flow hijacking attacks, by preventing an attacker from abusing specific code in the program to divert the program to a malicious execution. Then, this dissertation presents RSTI, a new defense mechanism that overcomes the limitations of PACTight and extends it to cover data oriented attacks and prevent attackers from leaking sensitive data from the program. In addition to that, this dissertation presents sPACtre, a novel defesnse mechanism that defends against Spectre attacks, and prevents an attacker from abusing a processor's hidden features. Finally, this dissertation briefly discusses a possible future direction to protect a different class of devices, referred to as energy-harvesting devices, from attackers.

Yes / This paper presents the architectural design, software implementation, the validation and flight trial results of an aeronautical communications system developed within the Seamless Aeronautical Networking through integration of Data links Radios and Antennas (SANDRA) project funded by the European 7th Framework Aeronautics and Transport Programme. Based on Software Defined Radio (SDR) techniques, an Integrated Modular Radio (IMR) platform was developed to accommodate several radio technologies. This can drastically reduce the size, weight and cost in avionics with respect to current radio systems implemented as standalone equipment. In addition, the modular approach ensures the possibility to dynamically reconfigure each radio element to operate on a specific type of radio link. A radio resource management (RRM) framework is developed in the IMR consisting of a communication manager for the resource allocation and management of the different radio links and a radio adaptation manager to ensure protocol convergence through IP. The IMR has been validated though flight trials held at Oberpfaffenhofen, Germany in June 2013. The results presented in the paper validate the flexibility and scalability of the IMR platform and demonstrate seamless service coverage across different airspace domains through interworking between the IMR and other components of the SANDRA network. / European Commission

Dynamic modelling and optimization of three different processes namely (a) bulk polymerization of styrene, (b) solution polymerization of methyl methacrylate (MMA) and (c) emulsion copolymerization of Styrene and MMA in batch and semi-batch reactors are the focus of this work. In this work, models are presented as sets of differential-algebraic equations describing the process. Different optimization problems such as (a) maximum conversion (Xn), (b) maximum number average molecular weight (Mn) and (c) minimum time to achieve the desired polymer molecular properties (defined as pre-specified values of monomer conversion and number average molecular weight) are formulated. Reactor temperature, jacket temperature, initial initiator concentration, monomer feed rate, initiator feed rate and surfactant feed rate are used as optimization variables in the optimization formulations. The dynamic optimization problems were converted into nonlinear programming problem using the CVP techniques which were solved using efficient SQP (Successive Quadratic Programming) method available within the gPROMS (general PROcess Modelling System) software. The process model used for bulk polystyrene polymerization in batch reactors, using 2, 2 azobisisobutyronitrile catalyst (AIBN) as initiator was improved by including the gel and glass effects. The results obtained from this work when compared with the previous study by other researcher which disregarded the gel and glass effect in their study which show that the batch time operation are significantly reduced while the amount of the initial initiator concentration required increases. Also, the termination rate constant decreases as the concentration of the mixture increases, resulting rapid monomer conversion. The process model used for solution polymerization of methyl methacrylate (MMA) in batch reactors, using AIBN as the initiator and Toluene as the solvent was improved by including the free volume theory to calculate the initiator efficiency, f. The effects of different f was examined and compared with previous work which used a constant value of f 0.53. The results of these studies show that initiator efficiency, f is not constant but decreases with the increase of monomer conversion along the process. The determination of optimal control trajectories for emulsion copolymerization of Styrene and MMA with the objective of maximizing the number average molecular weight (Mn) and overall conversion (Xn) were carried out in batch and semi-batch reactors. The initiator used in this work is Persulfate K2S2O8 and the surfactant is Sodium Dodecyl Sulfate (SDS). Reduction of the pre-batch time increases the Mn but decreases the conversion (Xn). The sooner the addition of monomer into the reactor, the earlier the growth of the polymer chain leading to higher Mn. Besides that, Mn also can be increased by decreasing the initial initiator concentration (Ci0). Less oligomeric radicals will be produced with low Ci0, leading to reduced polymerization loci thus lowering the overall conversion. On the other hand, increases of reaction temperature (Tr) will decrease the Mn since transfer coefficient is increased at higher Tr leading to increase of the monomeric radicals resulting in an increase in termination reaction.

<p>Ова докторска теза описује и анализира приступ развоју Це компајлера за<br />наменске процесоре. Такав компајлер захтева имплементацију посебних<br />техника и алгоритама, претежно специфичних за нерегуларне процесорске<br />архитектуре, да би генерисао ефикасан код, и при том је потребно да<br />испуњава индустријске стандарде по питању робустности, разумљивости<br />кода, могућности одржавања и проширивости. У ту сврху је предложена<br />нова компајлерска инфраструктура над којом је имплементиран компајлер<br />за Cirrus Coyote 32 ДСП. Квалитет генерисаног кода поређен је са<br />квалитетом кода генерисног од стране већ постојећег компајлера за тај<br />процесор. Уједно, одређени елементи организације компајлера су<br />упоређени са популарним компајлерима отвореног кода GCC и LLVM.</p> / <p>Ova doktorska teza opisuje i analizira pristup razvoju Ce kompajlera za<br />namenske procesore. Takav kompajler zahteva implementaciju posebnih<br />tehnika i algoritama, pretežno specifičnih za neregularne procesorske<br />arhitekture, da bi generisao efikasan kod, i pri tom je potrebno da<br />ispunjava industrijske standarde po pitanju robustnosti, razumljivosti<br />koda, mogućnosti održavanja i proširivosti. U tu svrhu je predložena<br />nova kompajlerska infrastruktura nad kojom je implementiran kompajler<br />za Cirrus Coyote 32 DSP. Kvalitet generisanog koda poređen je sa<br />kvalitetom koda generisnog od strane već postojećeg kompajlera za taj<br />procesor. Ujedno, određeni elementi organizacije kompajlera su<br />upoređeni sa popularnim kompajlerima otvorenog koda GCC i LLVM.</p> / <p>This PhD thesis describes and analyses an approach to development of C<br />language compiler for embedded processors. That kind of compiler requires<br />implementation of special techniques and algorithms, mostly specific for<br />irregular processor architectures, in order to be able to generate efficient<br />code, whereas still meeting industrial strength standard by beeing robust,<br />understandable, maintainable, and extensible. For this purpose the new<br />compiler insfrastructure is proposed and on top of it a compiler for Cirrus<br />Logic Coyote 32 DSP is built. Quality of the code generated by that compiler<br />is compared with code generated by the previous compiler for the same<br />processor architecture. Some elements of the compiler design are also<br />compared to popular open source compilers GCC and LLVM.</p>

Made available in DSpace on 2015-03-03T15:36:12Z (GMT). No. of bitstreams: 1 EduardoSS_DISSERT.pdf: 804086 bytes, checksum: 7991c16751047e96e7a210e52bd8df36 (MD5) Previous issue date: 2013-08-14 / The aim of this work is to provide a text to support interested in the main systems of amortization of the current market: Constant Amortization System (SAC) and French System, also known as Table Price. We will use spreadsheets to facilitate calculations involving handling exponential and decimal. Based on [12], we show that the parcels of the SAC become smaller than the French system after a certain period. Further then that, we did a comparison to show that the total amount paid by SAC is less than the French System / O objetivo deste trabalho e oferecer um texto de apoio aos interessados nos principais sistemas de amortizac??o do mercado atual: Sistema de Amortiza??o Constante (SAC) e Sistema Franc?s, tamb?m conhecido por Tabela Price. Utilizamos planilhas eletr?nicas para facilitar os c?lculos que envolvem manipula??o de exponenciais e decimais. Baseados em [12], mostramos que as presta??es do SAC tornam-se menores que as do Sistema Franc?s a partir de certo per?odo de financiamento. Al?m disso, fazemos uma compara??o para mostrar que o montante total pago pelo SAC e menor que o do Sistema Franc?s

This thesis deals with the possibilities of enterprise informatics solutions in the SME (small and medium enterprises). This target group is further specified and is taken into account especially the most strongly represented subjects in SMEs - micro-enterprises. The main goal of this work is exploring the practical use of modern trends in information systems such as cloud computing or SaaS in direct comparison with conventional enterprise informatics solutions. In the first part is the space dedicated primarily to theoretical definition of concepts and identification of elaborated topics. Inside acquaintance with individual technical terms there is an example of one particular definition of company enterprise informatics solutions demonstrated with practical examples. The needs and solving the needs of small businesses are then generalized to the common needs of such small companies. Another part is dedicated to the actual analysis of the market and possible solutions of enterprise informatics. According to the specific needs of small businesses several optimal solutions are selected and further more thoroughly investigated and tested. The collected data serve for subsequent comparison of possible enterprise informatics solutions with particular results. The reader himself can assess complexity and price of technologies, especially in the context of conventional solutions and new products. For evaluation of the needs of these small companies primarily MMDIS principles of the methodology are used. In conclusion of the thesis there is the evaluation of detected findings and creating of recommendations for these small businesses.