No / A novel acoustic sensor has been developed which is capable of remotely monitoring the free surface ‘fingerprint’ of shallow flows. The temporal and spatial properties of this fingerprint are shown to contain a wealth of information regarding the nature of the flow itself. The remote measurement can thereby be used to infer the bulk flow properties such as depth, velocity, and hydraulic roughness to within 8 % accuracy. The instrument is totally non-invasive and as such is low cost, low maintenance, and low power. Such a device will allow for widespread monitoring of flow conditions in drainage and river networks, informing flood models, and facilitating pro-active maintenance and real time control.

Control flow hijacking attacks such as Return Oriented Programming (ROP) and data oriented attacks like Data Oriented Programming (DOP) are problems still plaguing modern software today. While there have been many attempts at hardening software and protecting against these attacks, the heavy performance cost of running these defenses and intrusive modifications required has proven to be a barrier to adoption. In this work, we present Monguard, a high-performance hardware assisted in-process monitor protection system utilizing Intel Memory Protection Keys (MPK) to enforce execute-only memory, combined with code randomization and runtime binary patching to effectively protect and hide in-process monitors. Next, we introduce L-MVX, a flexible lightweight Multi-Variant Execution (MVX) system running in the in-process monitor system that aims to solve some of the performance problems of recent MVX defenses through selective program call graph protection and in-process monitoring, maintaining security guarantees either by breaking attacker assumptions or creating a scenario where a particular attack only works on a single variant. / Master of Science / Memory corruption attacks are still prevalent on modern software. While there have been many attempts at hardening software and preventing against these attacks, the heavy performance cost of running these defenses and intrusive modifications required have proven to be a barrier to adoption. In this work, we present L-MVX, a high-performance hardware assisted in-process monitor protection system that provides an unintrusive and efficient way to defend against these attacks on monitor systems. We also introduce L-MVX, a flexible lightweight process monitoring engine running on L-MVX that aims to solve some of the performance problems of recent monitor defenses.

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.

Esse trabalho foi desenvolvido com a finalidade de melhorar a qualidade dos serviços de calibração e testes de monitores de radiação gama, prestados pelo Laboratório de Calibração de Instrumentos do IPEN, assim como diminuir a dose ocupacional dos técnicos envolvidos no processo de calibração, seguindo os princípios de proteção radiológica. Foi realizado o desenvolvimento e a implantação de um sistema automatizado para o processo de calibração de monitores de radiação gama, constituido por (i) um dispositivo pneumático de troca dos atenuadores e (ii) uma mesa de posicionamento, ambos acionados remotamente por intermédio de um painel de comando. Também fez parte a implantação de um Sistema Irradiador Caesa-Gammatron, que aumentou o intervalo de taxa de kerma no ar, devido sua alta atividade em relação ao sistema atualmente em uso no laboratório de calibração com radiação gama. Para isso, foi necessária a instalação de um dispositivo atenuador controlado remotamente nesse sistema irradiador. Por último foi realizado uma avaliação da redução da dose ocupacional. / This work was developed with the aim of improving the quality of the services of calibration and tests of gamma radiation monitors - provided by the IPEN Laboratory of Instrument Calibration - as well as reducing the occupational dose in technicians involved in the process of calibration, following the principles of radiation protection. In this study it was carried out the development and implementation of a system for adequation of the process of gamma radiation monitors calibration. It is constituted by (i) a pneumatic dispositive to exchange the attenuators and (ii) a positioning table, both actuated through a control panel. System was also implemented. A Caesa-Gammatron Irradiator, which increased the range of the air kerma rates, due to its activity higher than the current system of gamma radiation in use in the calibration laboratory. Hence, it was necessary the installation of remotely controlled in the attenuator dispositive in this irradiator system. Lastly, it was carried out an evaluation in the reduction of the occupational doses.

Considerando a importância da garantia de esterilidade em produtos médico-hospitalares, e conhecendo a necessidade de controle do processo esterilizante por óxido de etileno através de vários parâmetros dentre eles pelo sensor biológico, este trabalho teve como objetivo a padronização de alguns aspectos importantes do monitor biológico. Esporos de Bacillus subtilis var. niger foram obtidos em meios sólido e líquido sintético de esporulação, assim como adquiridos no comércio nacional, como suspensão. Seguiu-se a inoculação destes sobre suportes de papel, alumínio e plástico, com subsequente acondicionamento em embalagens protetoras, com o que se chegou à preparação dos indicadores biológicos. Foram testados, comparativamente, indicadores biológicos, em suporte de papel, adquiridos no comércio nacional e norte americano. As variáveis consideradas no preparo de monitores biológicos foram: natureza do suporte e da embalagem e dimensão de corpo de prova. Foram preparados 27 grupos de monitores biológicos, sendo 19 em suporte de papel, 4 em alumínio e 4 em plástico, constituindo assim 3 grupos múltiplos. A verificação da influência da natureza do suporte na resistência dos esporos foi através do processamento sub-letal de monitores biológicos, seguido de estudo de letalidade e cálculo dos valores de D. Com relação aos 19 grupos em suporte de papel, apesar da origem diferenciada dos esporos no tocante à fase de esporulação, seja quanto à natureza do meio de cultura, do ciclo ou do laboratório produtor, ou ainda dos bioindicadores de fabricantes distintos, não houve diferença estatisticamente significante na resistência dos esporos ao agente esterilizante. Houve diferença significativa na resistência dos esporos entre suportes de papel e plástico. Com relação à efetividade esterilizante do gás através de embalagens de natureza diferente foram testados monitores biológicos contendo bioindicadores em suporte de papel, após exposição dos mesmos ao ciclo sub-letal. Os valores de D obtidos evidenciaram a compatibilidade de diferentes embalagens com a esterilização por óxido de etileno, desde que respeitada a característica de porosidade. Num grupo adicional de monitores biológicos, utilizando papel como suporte em que a variável foi a dimensão dos corpos de prova o processo esterilizante foi por ciclo industrial seguido de recuperação dos esporos sobreviventes através de inoculação dos suportes em caldo tioglicolato, caldo caseina soja e este adicionado de azul de bromotimol. A capacidade promotora de crescimento destes 3 meios não apresentou diferenças. A eficácia esterilizante foi dependente do tamanho de corpos de prova. A determinação periódica do teor residual de gás nos corpos de prova, bem como a monitoração ambiental industrial indicaram a necessidade e importância da legislação em vigor, devendo haver plena obediência à mesma. / This study intended to standardize some of the important elements of biological indicators, taken in consideration the importance of sterility assurance of medical devices and knowing the necessity of Ethilene Oxide sterilization process control throught several parameters, among them the biological sensor. Spores of Bacillus .subtilis var. niger, were produced in chemically defined liquid and solid sporulation media, as well as purchased as suspension from local suppliers. The biological indicators were obtained after being inoculated on paper, aluminum foil and plastic carriers following by wrapping on protective packaging. In parallel biological indicators in paper carriers, purchased from local market and from United States suppliers were also tested. The variables considered on preparation of the biological monitors were: the nature of the carriers and packages used and the dimension of the test specimens. Twenty seven individual groups of biological monitors have been prepared, being 19 on paper carrier, 4 into aluminum foil and 4 into plastic, bringing to 3 multiple groups. The evaluation of the nature of the carrier on the spore resistance was done through the challange of the biological monitors to sub-lethal cycles, followed by lethality study and D value calculation. Within the 19 groups on paper carrier no significant statistical difference was observed in respect to spores resistance to the sterilization agent, in spite of the various sources of the spores, with respect to the sporulation stage, no matter the nature of culture media, the cycle or the generating laboratory, or even bioindicators from distinct manufacturers. There was an significant statistical difference on spores resistance between paper and plastic carriers. In respect to the gas sterilization effectiveness across packages of different nature, biological monitors were tested containing bioindicators in paper carriers, after their exposure to sub-lethal cycles. The D values obtained made patent the compatibility of distinct packages to ethilene oxide sterilization provided the porosity caracteristics are respected. In an additional group of biological, monitors, using paper as carrier and on that the dimension of the test specimens was the variable considered the sterilization process was an industrial cycle, followed by a surviving spores recovery through the carriers inoculation into thioglicolate broth, soybean-casein broth and also the last broth added with bromothymol blue. The growing promoting capacity of those 3 media did not show differences. The sterilization effectiveness was dependent to the dimension of the test specimens. The periodic determination of residual gas content on the test specimens, as well as the industrial environment monitoring denote the need and importance of the legislation in force, being imperative full compliance to the same.

Considerando a importância da garantia de esterilidade em produtos médico-hospitalares, e conhecendo a necessidade de controle do processo esterilizante por óxido de etileno através de vários parâmetros dentre eles pelo sensor biológico, este trabalho teve como objetivo a padronização de alguns aspectos importantes do monitor biológico. Esporos de Bacillus subtilis var. niger foram obtidos em meios sólido e líquido sintético de esporulação, assim como adquiridos no comércio nacional, como suspensão. Seguiu-se a inoculação destes sobre suportes de papel, alumínio e plástico, com subsequente acondicionamento em embalagens protetoras, com o que se chegou à preparação dos indicadores biológicos. Foram testados, comparativamente, indicadores biológicos, em suporte de papel, adquiridos no comércio nacional e norte americano. As variáveis consideradas no preparo de monitores biológicos foram: natureza do suporte e da embalagem e dimensão de corpo de prova. Foram preparados 27 grupos de monitores biológicos, sendo 19 em suporte de papel, 4 em alumínio e 4 em plástico, constituindo assim 3 grupos múltiplos. A verificação da influência da natureza do suporte na resistência dos esporos foi através do processamento sub-letal de monitores biológicos, seguido de estudo de letalidade e cálculo dos valores de D. Com relação aos 19 grupos em suporte de papel, apesar da origem diferenciada dos esporos no tocante à fase de esporulação, seja quanto à natureza do meio de cultura, do ciclo ou do laboratório produtor, ou ainda dos bioindicadores de fabricantes distintos, não houve diferença estatisticamente significante na resistência dos esporos ao agente esterilizante. Houve diferença significativa na resistência dos esporos entre suportes de papel e plástico. Com relação à efetividade esterilizante do gás através de embalagens de natureza diferente foram testados monitores biológicos contendo bioindicadores em suporte de papel, após exposição dos mesmos ao ciclo sub-letal. Os valores de D obtidos evidenciaram a compatibilidade de diferentes embalagens com a esterilização por óxido de etileno, desde que respeitada a característica de porosidade. Num grupo adicional de monitores biológicos, utilizando papel como suporte em que a variável foi a dimensão dos corpos de prova o processo esterilizante foi por ciclo industrial seguido de recuperação dos esporos sobreviventes através de inoculação dos suportes em caldo tioglicolato, caldo caseina soja e este adicionado de azul de bromotimol. A capacidade promotora de crescimento destes 3 meios não apresentou diferenças. A eficácia esterilizante foi dependente do tamanho de corpos de prova. A determinação periódica do teor residual de gás nos corpos de prova, bem como a monitoração ambiental industrial indicaram a necessidade e importância da legislação em vigor, devendo haver plena obediência à mesma. / This study intended to standardize some of the important elements of biological indicators, taken in consideration the importance of sterility assurance of medical devices and knowing the necessity of Ethilene Oxide sterilization process control throught several parameters, among them the biological sensor. Spores of Bacillus .subtilis var. niger, were produced in chemically defined liquid and solid sporulation media, as well as purchased as suspension from local suppliers. The biological indicators were obtained after being inoculated on paper, aluminum foil and plastic carriers following by wrapping on protective packaging. In parallel biological indicators in paper carriers, purchased from local market and from United States suppliers were also tested. The variables considered on preparation of the biological monitors were: the nature of the carriers and packages used and the dimension of the test specimens. Twenty seven individual groups of biological monitors have been prepared, being 19 on paper carrier, 4 into aluminum foil and 4 into plastic, bringing to 3 multiple groups. The evaluation of the nature of the carrier on the spore resistance was done through the challange of the biological monitors to sub-lethal cycles, followed by lethality study and D value calculation. Within the 19 groups on paper carrier no significant statistical difference was observed in respect to spores resistance to the sterilization agent, in spite of the various sources of the spores, with respect to the sporulation stage, no matter the nature of culture media, the cycle or the generating laboratory, or even bioindicators from distinct manufacturers. There was an significant statistical difference on spores resistance between paper and plastic carriers. In respect to the gas sterilization effectiveness across packages of different nature, biological monitors were tested containing bioindicators in paper carriers, after their exposure to sub-lethal cycles. The D values obtained made patent the compatibility of distinct packages to ethilene oxide sterilization provided the porosity caracteristics are respected. In an additional group of biological, monitors, using paper as carrier and on that the dimension of the test specimens was the variable considered the sterilization process was an industrial cycle, followed by a surviving spores recovery through the carriers inoculation into thioglicolate broth, soybean-casein broth and also the last broth added with bromothymol blue. The growing promoting capacity of those 3 media did not show differences. The sterilization effectiveness was dependent to the dimension of the test specimens. The periodic determination of residual gas content on the test specimens, as well as the industrial environment monitoring denote the need and importance of the legislation in force, being imperative full compliance to the same.

As Máquinas Virtuais ganharam grande importância com o advento de processadores multi-core (na plataforma x86) e com o barateamento de componentes de hardware, como a memória. Por conta desse substancial aumento do poder computacional, surgiu o desafio de tirar proveito dos recursos ociosos encontrados nos ambientes corporativos, cada vez mais populados por equipamentos multi-core e com vários Gigabytes de memória. A virtualização, mesmo sendo um conceito já antigo, tornou-se novamente popular neste cenário, pois com ela foi possível utilizar melhor os recursos computacionais, agora abundantes. Este trabalho tem como principal foco estudar algumas das principais técnicas de gerência de recursos computacionais em ambientes virtualizados. Apesar de muitos dos conceitos aplicados nos projetos de Monitores de Máquinas Virtuais terem sido portados de Sistemas Operacionais convencionais com pouca, ou nenhuma, alteração; alguns dos recursos ainda são difíceis de virtualizar com eficiência devido a paradigmas herdados desses mesmos Sistemas Operacionais. Por fim, é apresentado o Memory Dispatcher (MD), um mecanismo de gerenciamento de memória, com o objetivo principal de distribuir a memória entre as Máquinas Virtuais de modo mais eficaz. Este mecanismo, implementado em C, foi testado no Monitor de Máquinas Virtuais Xen e apresentou ganhos de memória de até 70%. / Virtual Machines have gained great importance with advent of multi-core processors (on platform x86) and with low cost of hardware parts, like physical memory. Due to this computational power improvement a new challenge to take advantage of idle resources has been created. The virtualization technology, even being an old concept became popular in research centers and corporations. With this technology idle resources now can be exploited. This work has the objective to show the main techniques to manage computational resources in virtual environments. Although many of current concepts used in Virtual Machine Monitors project has been ported, with minimal changes, from conventional Operating Systems there are some resources that are difficult to virtualize with efficiency due to old paradigms still present in Operating Systems projects. Finally, the Memory Dispatcher (MD) is presented, a mechanism used to memory management. The main objective of MD is to improve the memory share among Virtual Machines. This mechanism was developed in C and it was tested in Xen Virtual Machine Monitor. The MD showed memory gains up to 70%.

Esse trabalho foi desenvolvido com a finalidade de melhorar a qualidade dos serviços de calibração e testes de monitores de radiação gama, prestados pelo Laboratório de Calibração de Instrumentos do IPEN, assim como diminuir a dose ocupacional dos técnicos envolvidos no processo de calibração, seguindo os princípios de proteção radiológica. Foi realizado o desenvolvimento e a implantação de um sistema automatizado para o processo de calibração de monitores de radiação gama, constituido por (i) um dispositivo pneumático de troca dos atenuadores e (ii) uma mesa de posicionamento, ambos acionados remotamente por intermédio de um painel de comando. Também fez parte a implantação de um Sistema Irradiador Caesa-Gammatron, que aumentou o intervalo de taxa de kerma no ar, devido sua alta atividade em relação ao sistema atualmente em uso no laboratório de calibração com radiação gama. Para isso, foi necessária a instalação de um dispositivo atenuador controlado remotamente nesse sistema irradiador. Por último foi realizado uma avaliação da redução da dose ocupacional. / This work was developed with the aim of improving the quality of the services of calibration and tests of gamma radiation monitors - provided by the IPEN Laboratory of Instrument Calibration - as well as reducing the occupational dose in technicians involved in the process of calibration, following the principles of radiation protection. In this study it was carried out the development and implementation of a system for adequation of the process of gamma radiation monitors calibration. It is constituted by (i) a pneumatic dispositive to exchange the attenuators and (ii) a positioning table, both actuated through a control panel. System was also implemented. A Caesa-Gammatron Irradiator, which increased the range of the air kerma rates, due to its activity higher than the current system of gamma radiation in use in the calibration laboratory. Hence, it was necessary the installation of remotely controlled in the attenuator dispositive in this irradiator system. Lastly, it was carried out an evaluation in the reduction of the occupational doses.

Electric fencing is commonly used on New Zealand's farms. Modern technology is used in farm management systems to solve old farming problems in a more efficient and simple way. Engineers have researched the use of the electric fence as a communication medium and new technologies based on transmission line theory are used at present to monitor and troubleshoot problems occurring in electric fences. The next stage of the development is to use wireless devices to accomplish those same tasks from remote locations. This project aims to develop a prototype that provides a wireless link between an electric fence and a personal computer in a remote location. This prototype is expected to prove concepts that lead to the future design of useful, marketable products. The project was supported by Gallagher Electronics and is implemented using their existing products where possible.

The purpose of this project is to establish a correlation between precipitation and background gamma radiation levels at radiation portal monitors (RPM) deployed at various ports worldwide, and to devise a mechanism by which the effects of these precipitation-induced background fluctuations could be mitigated. The task of detecting special nuclear materials (SNM) by passive gamma spectroscopy is very difficult due to the low signal-to-noise ratio observed in an uncontrolled environment. Due to their low activities and the low energies of their characteristic gamma rays, the signals from many types of SNM can easily be obscured by background radiation. While this can be somewhat mitigated by taking regular background radiation measurements, even this cannot resolve the issue if background levels change suddenly and dramatically. Furthermore, any increase in background count rate will increase the statistical uncertainty of the count rate measurement, and thus decrease the minimum quantity of SNM that can be reliably detected. Existing research suggests that the advent of precipitation is the culprit behind many such large and sudden increases in background radiation. The correlation between precipitation and background levels was explored by in-situ testing on a full-scale portal monitor at Oak Ridge National Laboratory, and by comparing previously recorded background radiation and weather data from portal monitors located at ports worldwide. The first was utilized to determine the frequency and magnitude at which precipitation introduces background activity, and the second was used to quantify the effects of various quantities and types of precipitation in various parts of the world. Once this analysis was complete, various methods of mitigating these changes in background radiation were developed based on the collected data. Precipitation was found to be the most common culprit for rapid increases in background count rate, and was attributable to 85.6% of all such events. Based on extensive simulation via the Origen-ARP and MCNP software, a response function for the portal monitor was developed, and an algorithm designed to predict the contribution of the precipitation to the background count rate was developed. This algorithm was able to attenuate the contribution of precipitation to the background count rate by an average of 45% with very minimal over-correction. Such an algorithm could be utilized to adjust the alarm levels of the RPM to better allow it to compensate for the rise and fall in background count rate due to precipitation. Additionally, the relative contribution of precipitation which landed at various distances from the portal monitor to the increase in background count rate was measured via simulation. This simulation demonstrated that 37.2% of all background counts were due to the radon daughters which landed within a 2.76 m radius from the center of the portal monitor. This radius encompasses the area between the two portals. Based on this, several designs for shielding were simulated, the most successful of which was a concrete structure that was able to attenuate 71.3% of the background radiation caused by a given precipitation event at a materials cost of approximately $6,000 per RPM. This method is recommended as the primary means of mitigating this issue.