Este trabalho aborda um sistema de aquisição de dados (SAD) analógico-digital, baseado em um esquema redundante com diversidade de projeto, que é testado em dois ambientes diferentes de radiação. O primeiro experimento considera um teste de dose total ionizante (Total Ioninzig Dose - TID) sob irradiação gama, e o segundo experimento considera os efeitos de eventos singulares (Single Event Effects - SEE) sob irradiação por íons pesados. O SAD é composto, principalmente, por três conversores analógicos-digitais (ADCs) e dois votadores. A técnica usada é a Redundância Modular Tripla (Triple Modular Redundancy - TMR), com implementação em diferentes níveis de diversidade (temporal e arquitetural). O sistema é construído em um System-on-Chip programável (PSoC 5LP) da Cypress Semiconductor, fabricado em tecnologia CMOS de 130nm. Para a irradiação com TID, se utiliza o PSoC de part number CY8CKIT-050 sob uma fonte de radiação gama de 60Co (cobalto-60), com uma taxa de dose efetiva de 1 krad(Si)/h por 10 dias, atingindo uma dose total de 242 krad(Si) Para SEE se utiliza o protótipo PSoC de part number CY8CKIT-059 (sem encapsulamento) em um acelerador de partículas 8UD Pelletron usando 16O (oxigeno-16) ao vácuo, com energia de 36 MeV em um LET aproximado de 5.5 MeV/mg/cm2 e uma penetração no silício de 25 mm, resultando em um fluxo de 354 p/cm2.s, e uma fluência de 5077915 p/cm2 depois de 14755 segundos (4h 09min). Observou-se com o resultado do primeiro estudo que um (1) dos módulos do sistema apresentou uma degradação significativa na sua linearidade durante a irradiação, enquanto os outros tiveram uma degradação menos grave, mantendo assim a funcionalidade e confiabilidade do sistema. Durante o tempo de irradiação do segundo estudo, foram observadas 139 falhas: 53 SEFIs (Single Events Funtional Interrupt), 29 falhas críticas e 57 falhas SDC (Silent Data Corruption), atingindo as diferentes copias do sistema e um dos votadores do mesmo, mas sempre mantendo a saída esperada. Nos dois experimentos se evidencia a vantagem de usar a diversidade de projeto, além do TMR, para melhorar a resiliência e confiabilidade em sistemas críticos redundantes que trabalham com sinais mistos. / This work presents an analog-to-digital data acquisition system (DAS) based on a redundant scheme with design diversity, being tested in two different radiation environments. The first experiment is a Total Ionizing Dose (TID) essay and the second one considers Single Event Effects (SEE) under heavy ion irradiation. The DAS is mainly composed of three analog-todigital converters (ADCs) and two voters. The used technique was the Triple Modular Redundancy (TMR) implementing different levels of diversity (temporal and architectural). The circuit was built in a programmable System-on-Chip (PSoC 5LP) from Cypress Semiconductor, fabricated in a 130nm CMOS technology process. For the irradiation with TID the part number CY8CKIT-050 PSoC was used under a 60Co (cobalt-60) gamma radiation source, with an effective dose rate of 1 krad(Si)/h during 10 days, reaching a total dose of 242 krad(Si). For SEE experiments the part number CY8CKIT-059 (without encapsulation) PSoC prototype under a 8UD Pelletron particle accelerator using 16O (oxigen-16) under vacuum, with an energy of 36 MeV, resulting in a flux of 354p/cm2.s and a fluence of 5077915p/cm2 after 14755 seconds (4h 09min). As result of the first study it was observed that one of the system’s modules presented a significant degradation in its linearity during the irradiation, while degradations in the other modules were not as deep, maintaining the system’s functionality and reliability. During the period of the radiation of the second study, 139 faults were observed, 82 of them were critical and 57 were SDC (Silent Data Corruption), reaching the different system copies and one of the voters, while always maintaining the correct output. The advantage of using diversity, besides TMR, to improve resilience and reliability in redundant systems working with mixed signals was demonstrated in both experiments.

Le corps humain possède une grande redondance musculo-squelettique, se traduisant par une infinité de coordinations musculaires possibles pour produire un effort résultant. Lors d'un mouvement, le système nerveux central est confronté à la gestion de cette redondance. A travers l’analyse de cohérence entre les signaux électromyographiques, ce travail de thèse étudie le rôle fonctionnel du couplage intermusculaire et explore la contribution des mécanismes nerveux impliqués dans la régulation de la redondance musculaire en termes de contrôle de l’activité des muscles agonistes, et antagonistes impliqués dans le phénomène de co-contraction. Nos résultats ont révélé que le couplage intermusculaire entre deux muscles agonistes est modulé en présence de fatigue et en fonction de l’expertise sportive. De plus, le couplage entre muscles agonistes et antagonistes dépend des contraintes mécaniques et du rôle fonctionnel des muscles, et semble directement lié au niveau de co-contraction. La cohérence intermusculaire est modulée dans plusieurs bandes de fréquence, témoignant de l’implication de différentes commandes centrales communes d’origines spinales et supra-spinales. Nos conclusions amènent à penser que la coordination musculaire est en partie contrôlée par des commandes nerveuses communes dont la contribution est modulée suivant les propriétés fonctionnelles des muscles concernées, pour s’adapter de manière optimale aux contraintes internes ou externes de la tâche. Les travaux déjà engagés proposent de contribuer à une meilleure compréhension des mécanismes sous-jacents l’altération de la fonction motrice chez des patients cérébro-lésés. / The human motor system is characterized by high musculoskeletal redundancy, implying that a given resultant effort can result from infinity of feasible muscle coordinations. During a movement, the central nervous system has to manage such redundancy. Through coherence analysis between electromyographic signals, this thesis work aims at investigating the functional role of intermuscular coupling and at better understanding the contribution of central nervous mechanisms responsible for the regulation of muscle redundancy, in terms of agonist muscle activity and also antagonist muscles activity involved in co-contraction. Our results revealed that intermuscular coupling between agonist muscles is modulated according to both the fatigue level and the training status. We also showed that the coupling between agonist and antagonist muscles depends on the mechanical configuration and functional role of muscle pairs, and seems directly related to co-contraction. The modulation of intermuscular coherence occurs in several frequency bands, suggesting the involvement of different common central drives of spinal and supra-spinal origins according to task constraints. Taken together, our results lead us to conclude that common neural drives take part in the control of muscular coordination, with different relative contribution according to the functional properties of recruited muscles, in order to optimally adapt to both internal and external task contraints. Work already undertaken proposes to provide a better understanding of the mechanisms underlying impairment of motor function in brain-injured patients.

This study applied dual processing theory, the theory of working memory, and the theory of cue summation to examine how the video and audio in a television news story interact with or against each other when the story uses pull quote graphics to convey key information to viewers. Using eye-tracking, the study produced visual depictions of exactly what viewers look at on the screen when the words in the reporter's voice track match the text in the pull quote graphic verbatim, when the reporter summarizes the text in the graphic, and when the reporter's voice track ignores the text in the pull quote. The study tested the effect on recall when viewers were presented with these three story conditions—high redundancy, medium redundancy, and low redundancy, respectively. Key findings included the following: first, that stories with low redundancy resulted in lower recall and memory sensitivity scores (a measure of memory strength) than pull quotes that the reporter either summarized or read verbatim on the air. Second, it was found that neither high-redundancy nor medium-redundancy stories were superior or inferior to the other when looking at the effect on recall and memory sensitivity. And finally, in high-, medium-, and low-redundancy conditions, subjects stated that they relied more on the reporter's narration than the pull quote to get information. The study states possible implications for news producers and reporters and suggests future research in the broadcast television news industry.

SRAM-based FPGAs provide valuable computation resources and reconfigurability; however, ionizing radiation can cause designs operating on these devices to fail. The sensitivity of an FPGA design to configuration upsets, or its SEU sensitivity, is an indication of a design's failure rate. SEU mitigation techniques can reduce the SEU sensitivity of FPGA designs in harsh radiation environments. The reliability benefits of these techniques must be determined before they can be used in mission-critical applications and can be determined by comparing the SEU sensitivity of an FPGA design with and without these techniques applied to it. Many approaches can be taken to evaluate the SEU sensitivity of an FPGA design. This work describes a low-cost easier-to-implement approach for evaluating the SEU sensitivity of an FPGA design. This approach uses additional logic resources on the same FPGA as the design under test to determine when the design has failed, or deviated from its specified behavior. Three SEU mitigation techniques were evaluated using this approach: triple modular redundancy (TMR), configuration scrubbing, and user-memory scrubbing. Significant reduction in SEU sensitivity is demonstrated through fault injection and radiation testing. Two LEON3 processors operating in lockstep are compared against each other using on-chip error detection logic on the same FPGA. The design SEU sensitivity is reduced by 27x when TMR and configuration scrubbing are applied, and by approximately 50x when TMR, configuration scrubbing, and user-memory scrubbing are applied together. Using this approach, an SEU sensitivity comparison is made of designs implemented on both an Altera Stratix V FPGA and a Xilinx Kintex 7 FPGA. Several instances of a finite state machine are compared against each other and a set of golden output vectors, all on the same FPGA. Instances of an AES cryptography core are chained together and the output of two chains are compared using on-chip error detection. Fault injection and neutron radiation testing reveal several similarities between the two FPGA architectures. SEU mitigation techniques reduce the SEU sensitivity of the two designs between 4x and 728x. Protecting on-chip functional error detection logic with TMR and duplication with compare (DWC) is compared. Fault injection results suggest that it is more favorable to protect on-chip functional error detection logic with DWC than it is to protect it with TMR for error detection.

This study applied dual processing theory, the theory of working memory, and the theory of cue summation to examine how the video and audio in a television news story interact with or against each other when the story uses pull quote graphics to convey key information to viewers. Using eye-tracking, the study produced visual depictions of exactly what viewers look at on the screen when the words in the reporter's voice track match the text in the pull quote graphic verbatim, when the reporter summarizes the text in the graphic, and when the reporter's voice track ignores the text in the pull quote. The study tested the effect on recall when viewers were presented with these three story conditions—high redundancy, medium redundancy, and low redundancy, respectively. Key findings included the following: first, that stories with low redundancy resulted in lower recall and memory sensitivity scores (a measure of memory strength) than pull quotes that the reporter either summarized or read verbatim on the air. Second, it was found that neither high-redundancy nor medium-redundancy stories were superior or inferior to the other when looking at the effect on recall and memory sensitivity. And finally, in high-, medium-, and low-redundancy conditions, subjects stated that they relied more on the reporter's narration than the pull quote to get information. The study states possible implications for news producers and reporters and suggests future research in the broadcast television news industry.

Les réseaux des capteurs sans fil sont considérés comme une alternative aux réseaux câblés afin de permettre l'installation dans des zones peu accessibles. Par conséquent, de nouveaux protocoles ont été conçus pour supporter le manque des ressources qui est spécifique à ce type de réseau. La communication entre les nœuds est réalisée par des protocoles spécifiques pour la gestion efficace de l'énergie. La gestion des données collectées par ces nœuds doit être également prise en compte car la communication entre les nœuds engendre un coût non négligeable en termes d'énergie. De plus, l'installation de ce type de réseau dans des régions lointaines facilite les attaques sur la structure des réseaux ainsi que sur les données collectées. Les mesures de sécurité envisagées amènent des coûts d'énergie supplémentaires. Un aspect souvent négligé concerne le cas où un nœud ne peut pas communiquer avec la station de base (sink node) qui collectionne et traite les données. Cependant, les nœuds continuent à accumuler des informations en suivant les plans de collection. Si la situation continue, l'espace de mémoire (storage) diminue à un point où la collection de nouvelles données n'est plus possible.Nous proposons des mécanismes pour la réduction contrôlée de données en considérant leur priorité relative. Les données sont divisées dans des unités auxquelles un niveau d'importance est alloué, en fonction des considérations d'utilité et de missions qui les utilisent. Nous proposons un ensemble de primitives (opérations) qui permettent la réduction d'espace de stockage nécessaire, tout en préservant un niveau raisonnable de résolution des informations collectées. Pour les larges réseaux à multiple nœuds, nous proposons des mécanismes pour le partage de données (data load sharing) ainsi que la redondance. Des algorithmes ont été proposés pour évaluer l'efficacité de ces techniques de gestion de données vis-à-vis de l'énergie nécessaire pour transférer les données.A travers des simulations, nous avons validé le fait que les résultats sont très utiles dans les cas à mémoire limitée (wireless nades) et pour les communications intermittentes. / Wireless Sensor Networks have evolved as an alternative to wired networks fit for quick deployments in areas with limited access. New protocols have been deviees to deal with the inherent scarcity of resources that characterizes such netvorks. Energy efficient network protocols are used for communication between nades. Data collected by wireless nades is transmitted at an energy cost and therefore carefully managed. The remote deployment of wireless networks opens the possibility of malicious attacks on the data and on the infrastructure itself. Security measures have also been devised, but they come at an energy cost. One item that has received little attention is the situation of the data sink becoming unreachable. The nodes still collect data as instructed and accumulate it. Under prolonged unavailability of the sink node, the storage space on sensor nades is used up and collecting new data is no longer feasible. Our proposal for a prioritized data reduction alleviates this problem. The collected data is divided into data units who are assigned an importance level calculated in agreement with the business case. We have proposed data reduction primitive operations that reduce the needed space while only losing a limited amount of data resolution. A multi-node deployment opens the possibility for data load sharing between the nodes as well as redundancy. Algorithms were proposed to evaluate the potential gain ofthese approaches in relation to the amount of energy spent for data transfer. The proposed approach works well in coping with fixed size data storage by trimming the low interest data in a manner that data is still usable.

<p>I ulykkessammenheng går to av de vanligste undersøkelsesmetodene ut på henholdsvis å kartlegge det juridiske ansvaret for ulykken og å klarlegge årsaksforholdene. I media får vi stort sett bare høre om førstnevnte i form av oppslag om at ulykken skyldes menneskelig svikt. Årsaksforholdene tar gjerne lengre tid å kartlegge og har heller ikke elementer av helt eller syndebukk i seg, og er således mindre interessante å skrive om. I forebyggende sammenheng er det likevel gjerne her det er mest å hente. I erkjennelsen av at mennesket er og blir feilbarlig, bør man nettopp gripe tak i disse bakenforliggende årsakene, gjerne kalt latente feil, som også kan medvirke til å avverge at et tilløp får lov å utvikle seg til en ulykke. I denne oppgaven blir det gjort rede for bakenforliggende årsaker til en alvorlig samferdselsulykke på Vestlandet i 1999, nemlig hurtigbåten MS Sleipners forlis. Det blir også vist hvordan ulykken kunne vært unngått, eller i det minste at skadeomfanget kunne vært vesentlig redusert, dersom det hadde vært større fokus på å avdekke slike latente forhold. For å få offentligheten til å forstå viktigheten av slik årsakskartlegging, og ikke minst at ansvarlige instanser følger opp funnene i ettertid, er det viktig at media griper fatt i problemstillingen og setter den på dagsorden.</p> / <p>Two of the most common forms of investigations after accidents are the search for the judicial aspects of guilt on the one hand and the investigation to find the causes of the accident on the other hand. Media mainly tell us the result of the first one, namely that “the cause of the accident was human error”. Usually it takes more time to establish an understanding of the underlying causes. This investigation does not point out a hero, neither a scapegoat. Therefore the real causes are less interesting to the media. Still, when it comes to accident prevention, this is where one should make an effort. By recognizing the fact that humans are eligible to fail, it is here one should try to take preventive measures. By recognizing these latent conditions one may succeed to avoid potentially dangerous situations from developing to serious accidents. In this paper the underlying causes related to a serious accident that struck public transportation in Western Norway will be presented. The accident is the shipwreck of the high speed craft MS Sleipner in 1999. It will also be shown how this accident could have been prevented, or at least how the extent of the damage could have been substantially reduced, if only latent conditions had been paid a little more attention to. To make the general public understand the importance of uncovering such latent conditions, not to say make sure that they who are responsible take action to remove these conditions, it is vital that the media put these questions on the agenda.</p>

To stay competitive internationally, the Swedish forestry sector must increase its productivity by 2 to 3% annually. There are a variety of ways in which productivity can be increased. One option is to develop remote-controlled or unmanned machines, thus reducing the need for operator intervention. Another option—and one that could be achieved sooner than full automation—would be to make some functions semi-automatic. Semi-automatic operation of the knuckle boom and felling head in particular would create “mini-breaks” for the operators, thereby reducing mental and physiological stress. It would also reduce training time and increase the productivity of a large proportion of operators. The objective of this thesis work has been to develop and evaluate algorithms for simplified boom control on forest machines. Algorithms for so called boom tip control, as well as automatic boom functions have been introduced. The algorithms solve the inverse kinematics of kinematically redundant knuckle booms while maximizing lifting capacity. The boom tip control was evaluated – first by means of a kinematic simulation and then in a dynamic forest machine simulator. The results show that boom tip control is an easier system to learn in comparison to conventional control, leading to savings in production due to shorter learning times and operators being able to reach full production sooner. Boom tip control also creates less mental strain than conventional control, which in the long run will reduce mental stress on operators of forest machines. The maximum lifting capacity algorithm was then developed further to enable TCP path-tracking, which was also implemented and evaluated in the simulator. An evaluation of the fidelity of the dynamic forest machine simulator was performed to ensure validity of the results achieved with the simplified boom control. The results from the study show that there is good fidelity between the forest machine simulator and a real forest machine, and that the results from simulations are reliable. It is also concluded that the simulator was a useful research tool for the studies performed in the context of this thesis work. The thesis had two overall objectives. The first was to provide the industry and forestry sector with usable and verified ideas and results in the area of automation. This has been accomplished with the implementation of a simplified boom control and semi-automation on a forwarder in a recently started joint venture between a hydraulic manufacturer, a forest machine manufacturer and a forest enterprise. The second objective was to strengthen the research and development links between the forestry sector and technical university research. This has been accomplished through the thesis work itself and by a number of courses, projects and Masters theses over the last three years. About 150 students in total have been studying forest machine technology in one way or the other. / QC 20100729

There is mounting evidence that sustainable scale thresholds are now being exceeded worldwide and environmental resource shocks (e.g. climate change, water and oil shortages) may be inevitable in some regions of the world in the near future. These could result in severe economic breakdowns, welfare loss, and in the worst-case, the collapse of modern civilization. Therefore, a pre-eminent challenge of our times is to determine how to design a resilient (safe-fail) economy – one that can endure, adapt to and successfully recover from breakdowns when they occur. Surprisingly, while ecological economic theory relies heavily on natural science concepts such as thermodynamics, insufficient attention has been paid to the important ecological concept of resilience, particularly as it applies to economic design. The three major policy goals of current ecological economic theory (sustainable scale, just distribution and efficient allocation) focus instead on preventing environmental resource shocks and breakdowns, but given their unpredictability prevention may not always be possible. How resilience can inform the blossoming field of ecological economics is thus explored in this theoretical, transdisciplinary paper. Drawing on literature as diverse as archaeology and disaster planning, it develops six key principles of economic resilience and applies them to analyze the resilience of key societal systems including our money, electricity, water, transportation, information/communication and emergency response systems. Overall, economic resilience appears to be a unique concern that is not readily subsumed under any of the three existing ecological economic policy pillars. In fact, efforts to build in resilience have the potential to both complement and at times contradict the other three goals, especially efficiency. The need to further study these possible tradeoffs provides strong justification for adding a fourth distinct policy pillar, namely “Resilient Design”, to core ecological economic theory. Indeed, ecological economist’s longstanding criticism of economic growth meshes readily with the Resilience Alliance’s own figure-8 adaptive cycle theory critiquing the resilience costs of growth, providing significant opportunities for the future collaboration of these two fields in broadening global system theory.

Includes vita. / Title from PDF of title page. / Document formatted into pages; contains 155 pages. / Thesis (Ph.D.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: This dissertation research attempts to explore efficient algorithms and engineering methodologies of analyzing the overall reliability and availability of networks integrated with software failures and hardware failures. Node failures, link failures, and software failures are concurrently and dynamically considered in networks with complex topologies. MORIN (MOdeling Reliability for Integrated Networks) method is proposed and discussed as an approach for analyzing reliability of integrated networks. A Simplified Availability Modeling Tool (SAMOT) is developed and introduced to evaluate and analyze the availability of networks consisting of software and hardware component systems with architectural redundancy. / ABSTRACT: In this dissertation, relevant research efforts in analyzing network reliability and availability are reviewed and discussed, experimental data results of proposed MORIN methodology and SAMOT application are provided, and recommendations for future researches in the network reliability study are summarized as well. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.