Traditional cryptographic encryption techniques at higher layers require a certain form of information sharing between the transmitter and the legitimate user to achieve security. Besides, it also assumes that the eavesdropper has an insufficient computational capability to decrypt the ciphertext without the shared information. However, traditional cryptographic encryption techniques may be insufficient or even not suit- able in wireless communication systems. Physical layer security (PLS) can enhance the security of wireless communications by leveraging the physical nature of wireless transmission. Thus, in this thesis, we study the PLS performance in emerging wireless transmission systems. The thesis consists of two main parts. We first consider the PLS design and analysis for ground-based networks em- ploying random unitary beamforming (RUB) scheme at the transmitter. With RUB technique, the transmitter serves multiple users with pre-designed beamforming vectors, selected using limited channel state information (CSI). We study multiple-input single-output single-eavesdropper (MISOSE) transmission system, multi-user multiple-input multiple-output single-eavesdropper (MU-MIMOSE) transmission system, and massive multiple-input multiple-output multiple-eavesdropper (massive MI- MOME) transmission system. The closed-form expressions of ergodic secrecy rate and the secrecy outage probability (SOP) for these transmission scenarios are derived. Besides, the effect of artificial noise (AN) on secrecy performance of RUB-based transmission is also investigated. Numerical results are presented to illustrate the trade-off between performance and complexity of the resulting PLS design. We then investigate the PLS design and analysis for unmanned aerial vehicle (UAV)-based networks. We first study the secrecy performance of UAV-assisted relaying transmission systems in the presence of a single ground eavesdropper. We derive the closed-form expressions of ergodic secrecy rate and intercept probability. When multiple aerial and ground eavesdroppers are located in the UAV-assisted relaying transmission system, directional beamforming technique is applied to enhance the secrecy performance. Assuming the most general κ-μ shadowed fading channel, the SOP performance is obtained in the closed-form expression. Exploiting the derived expressions, we investigate the impact of different parameters on secrecy performance. Besides, we utilize a deep learning approach in UAV-based network analysis. Numerical results show that our proposed deep learning approach can predict secrecy performance with high accuracy and short running time. / Graduate

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Analytical modelling and characterization of Weighted Fair Queueing (WFQ) have recently received considerable attention by several researches since WFQ offers the minimum delay and optimal fairness guarantee. However, all previous work on WFQ has focused on developing approximations of the scheduler with an infinite buffer because of supposed scalability problems in the WFQ computation. The main aims of this thesis are to study WFQ system, by providing an analytical WFQ model which is a theoretical construct based on a form of processor sharing for finite capacity. Furthermore, the solutions for classes with Poisson arrivals and exponential service are derived and verified against global balance solution. This thesis shows that the analytical models proposed can give very good results under particular conditions which are very close to WFQ algorithms, where accuracy of the models is verified by simulations of WFQ model. Simulations were performed with QNAP-2 simulator. In addition, the thesis presents several performance studies signifying the power of the proposed analytical model in providing an accurate delay bounds to a large number of classes. These results are not able to cover all unsolved issues in the WFQ system. They represent a starting point for the research activities that the Author will conduct in the future. The author believes that the most promising research activities exist in the scheduler method to provide statistical guarantees to multi-class services. The author is convinced that alternative software, for example, on the three class model buffer case, is able to satisfy the large number of buffer because of the software limitation in this thesis. While they can be a good topic for long-term research, the short-medium term will show an increasing interest in the modification of the WFQ models to provide differentiated services.

International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / There has been much interest recently in the possibility of using the NASA Tracking and Data Relay Satellite System (TDRSS) instead of proprietary ground stations in supporting small space payload communications. These payloads operate on fairly low power and do not use the sophisticated tracking equipment standard on more complex user spacecraft. This paper is part of a feasibility study for such use of TDRSS, and focuses on the effect of the method of providing the Grade-2 data link layer services specified in Consultative Committee for Space Data Systems (CCSDS) Advanced Orbiting Systems (AOS) recommendations upon a hypothetical spacecraft using a MIL-STD-1553B polled data bus as the backbone of its onboard LAN. In particular, one case in which the 1553B bus controller, assumed to be some Intel 80X86 microprocessor, provides all CCSDS services will be contrasted with another where these services are split between the bus controller and a device which interfaces between the spacecraft LAN and the TDRSS Return Service spacelink. The comparison will be made for a 15 orbit/day scenario using a small helical antenna with a comparatively wide beamwidth. The main performance criteria considered here are end-to-end data throughput and expected delays, along with required buffer sizes for the LAN. Also, it may be noted that the data rate of the TDRSS return link and the size of the sliding window used for flow and error control will have a large impact on the required values for the chosen criteria, and so choices for these parameters significantly affect the outcome of any system service comparison. The two LAN types will be modeled and analyzed using NETWORK II.5. This simulator allows tracking of the number of packets read into LAN memories and sent down from the payload to ground via TDRSS, as well as accurately modeling the delays involved with data processing and transmission over the link.

Heterogeneous platforms play an increasingly important role in modern computer systems. They combine high performance with low power consumption. From mobiles to supercomputers, we see an increasing number of computer systems that are heterogeneous. The most well-known heterogeneous system, CPU+GPU platforms have been widely used in recent years. As they become more mainstream, serving multiple tasks from multiple users is an emerging challenge. A good scheduler can greatly improve performance. However, indiscriminately allocating tasks based on availability leads to poor performance. As modern GPUs have a large number of hardware resources, most tasks cannot efficiently utilize all of them. Concurrent task execution on GPU is a promising solution, however, indiscriminately running tasks in parallel causes a slowdown. This thesis focuses on scheduling OpenCL kernels. A runtime framework is developed to determine where to schedule OpenCL kernels. It predicts the best-fit device by using a machine learning-based classifier, then schedules the kernels accordingly to either CPU or GPU. To improve GPU utilization, a kernel merging approach is proposed. Kernels are merged if their predicted co-execution can provide better performance than sequential execution. A machine learning based classifier is developed to find the best kernel pairs for co-execution on GPU. Finally, a runtime framework is developed to schedule kernels separately on either CPU or GPU, and run kernels in pairs if their co-execution can improve performance. The approaches developed in this thesis significantly improve system performance and outperform all existing techniques.

Orientador: Lesley Carina do Lago Attadia Galli / Resumo: Este estudo teve por objetivo evidenciar a relevância da utilização do Facilities Management (FM) enquanto elemento estratégico na gestão da organização do setor sucroenergético. Foi fundamentado no referencial teórico que trouxe como abordagem conceitos e teorias do FM, práticas de FM em diferentes setores do mercado e sistema de medição de desempenho. Desenvolvido no escopo de pesquisa descritiva, com abordagem qualitativa, utilizou procedimentos de análise de dados e estudo de caso. A empresa em análise é a líder mundial no setor sucroenergético, composta por 26 unidades de produção canavieira. A investigação ocorreu através de análise do banco de dados do sistema de gestão de FM e entrevista com gestores da organização. Consistiu na análise dos métodos de gestão de medição de desempenho de FM aplicáveis na área de apoio administrativo direcionado a gestão das unidades de produção, a partir de métricas e indicadores estratégicos de desempenho relacionados a área. A partir da análise dos dados coletados durante a pesquisa de campo, constatou-se que a utilização do FM no processo podem gerar redução de custos, qualidade na gestão dos processos e melhorias nos indicadores da perspectiva interna do negócio. / Abstract: This study aimed to highlight the relevance of using Facilities Management (FM) as a strategic element in the management of the organization of the sugar-energy sector. It was based on the theoretical framework that approached FM concepts and theories, FM practices in different market sectors and performance measurement system. Developed in the scope of descriptive research, with qualitative approach, used data analysis procedures and case study. The unit of analysis was the world’s leading organization in the sugarenergy sector, consisting of 26 sugarcane production units. The research consisted of the analysis of FM performance measurement management methods applicable in the area of administrative support directed to the management of production units, based on metrics and strategic performance indicators related to the area. From the analysis of the data collected during the field research, it was found that the use of FM in the process could lead to cost reduction, quality in the process management and improvements in the indicators of the internal business perspective. / Mestre

The consequences of mine seismicity can be mitigated by installing support systems capable of absorbing the energy generated by seismic events. Recent work has focused on the testing of individual support or reinforcement units under laboratory impact loads; this, however, does not render itself to easy extrapolation to field conditions. Hence, this thesis focuses on improving the understanding of the performance of support systems in real-world applications through passive monitoring of past rockburst events. 14 years of rockburst history were collected from Coleman Mine and Copper Cliff Mine, two of Vale’s underground (nickel) operations in Sudbury Ontario. Statistical analysis, principal component analysis (PCA) and partial least square projection (PLS) were utilized to find relation between collected parameters and performance capacity. This thesis discusses the adequacy of various support systems and investigates the validity of perceived support performance as compared to the actual performance based on analyses of field data.

The consequences of mine seismicity can be mitigated by installing support systems capable of absorbing the energy generated by seismic events. Recent work has focused on the testing of individual support or reinforcement units under laboratory impact loads; this, however, does not render itself to easy extrapolation to field conditions. Hence, this thesis focuses on improving the understanding of the performance of support systems in real-world applications through passive monitoring of past rockburst events. 14 years of rockburst history were collected from Coleman Mine and Copper Cliff Mine, two of Vale’s underground (nickel) operations in Sudbury Ontario. Statistical analysis, principal component analysis (PCA) and partial least square projection (PLS) were utilized to find relation between collected parameters and performance capacity. This thesis discusses the adequacy of various support systems and investigates the validity of perceived support performance as compared to the actual performance based on analyses of field data.

Machine virtualization has become a cornerstone of modern datacenters. It enables server consolidation as a means to reduce costs and increase efficiencies. The communication endpoints within the datacenter are now virtual machines (VMs), not physical servers. Consequently, the datacenter network now extends into the server and last hop switching occurs inside the server. Today, thanks to increasing core counts on processors, server VM densities are on the rise. This trend is placing enormous pressure on the network I/O subsystem and the last hop virtual switch to support efficient communication, both internal and external to the server. But the current state-of-the-art solutions fall short of these requirements. This thesis presents new architectures and mechanisms for the network subsystem in virtualized servers to build efficient virtualization platforms. Specifically, there are three primary contributions in this thesis. First, it presents a new mechanism to reduce memory sharing overheads in driver domain-based I/O architectures. The key idea is to enable a guest operating system to reuse its I/O buffers that are shared with a driver domain. Second, it describes Hyper-Switch, a highly streamlined, efficient, and scalable software-based virtual switching architecture, specifically for hypervisors that support driver domains. The Hyper-Switch combines the best of the existing architectures by hosting the device drivers in a driver domain to isolate any faults and placing the virtual switch in the hypervisor to perform efficient packet switching. Further, the Hyper-Switch implements several optimizations, such as virtual machine state-aware batching, preemptive copying, and dynamic offloading of packet processing to idle CPU cores, to enable efficient packet processing, better utilization of the available CPU resources, and higher concurrency. This architecture eliminates the memory sharing overheads associated with driver domains. Third, this thesis proposes an alternate virtual switching architecture, called sNICh, which explores the idea of server/switch integration. The sNICh is a combined network interface card (NIC) and datacenter switching accelerator. This takes the Hyper-Switch architecture one step further. It offloads the data plane of the switch to the network device, eliminating driver domains entirely.

BACKGROUND Integrated healthcare systems are believed to be enabled by the electronic exchange of clinical information. Canada and other national health systems are making substantial investments in information technology, in order to liberate and share clinical information between providers, improve the quality and safety of care, and reduce costs, yet we currently have no way of measuring these information flows, nor of understanding whether they contribute to the integration of care delivery. METHODS A literature review and consensus development process (nominal group) were used to provide guidance on system integration measures which are enabled by electronic information exchange. In order to conceptualize the components of electronic information exchange, establish a reference vocabulary for terminology, and guide the development of a questionnaire to gather field data, a formal ontology was developed. Validation of a sub-group of the survey data quality was achieved using the ontology and an unrelated database, demonstrating how ontologies may be used to adapt performance measurement methodologies to systems where constraints such as time-compression, lack of resources or access to needed information are prevalent. RESULTS The survey tool gathered cross-sectoral data from a regional health system which populated a summary measure of inter-provider electronic health information exchange (the eHIE), and measured perceptions of system integration from a single health region. The eHIE indicated that 7 -12% of clinical information that could be shared, was being shared electronically in the health region. ANOVA confirmed a significant correlation between the amount of information being exchanged electronically in this system and respondent perceptions of system integration suggesting that the eHIE may be used as a leading indicator for healthcare system integration. CONCLUSIONS It is possible to conceptualize and quantify inter-provider electronic health information exchange. As complex adaptive systems, healthcare systems are dynamic and open to correction; the use of a leading or proximal indicator such as the eHIE may inform effective policy-making and resource allocation in our pursuit of the goal of seamlessly integrated care.