2,256 research outputs found
A Two Channel Analog Front end Design AFE Design with Continuous Time Σ-Δ Modulator for ECG Signal
In this context, the AFE with 2-channels is described, which has high impedance for low power application of bio-medical electrical activity. The challenge in obtaining accurate recordings of biomedical signals such as EEG/ECG to study the human body in research work. This paper is to propose Multi-Vt in AFE circuit design cascaded with CT modulator. The new architecture is anticipated with two dissimilar input signals filtered from 2-channel to one modulator. In this methodology, the amplifier is low powered multi-VT Analog Front-End which consumes less power by applying dual threshold voltage. Type -I category 2 channel signals of the first mode: 50 and 150 Hz amplified from AFE are given to 2nd CT sigma-delta ADC. Depict the SNR and SNDR as 63dB and 60dB respectively, consuming the power of 11mW. The design was simulated in a 0.18 um standard UMC CMOS process at 1.8V supply. The AFE measured frequency response from 50 Hz to 360 Hz, depict the SNR and SNDR as 63dB and 60dB respectively, consuming the power of 11mW. The design was simulated in 0.18 m standard UMC CMOS process at 1.8V supply. The AFE measured frequency response from 50 Hz to 360 Hz, programmable gains from 52.6 dB to 72 dB, input referred noise of 3.5 μV in the amplifier bandwidth, NEF of 3
HeteroSketch: coordinating network-wide monitoring in heterogeneous and dynamic networks
CNS-2107086 - National Science Foundation; CNS-2106946 - National Science FoundationPublished versio
Review and analysis of networking challenges in cloud computing
Cloud Computing offers virtualized computing, storage, and networking resources, over the Internet, to organizations and individual users in a completely dynamic way. These cloud resources are cheaper, easier to manage, and more elastic than sets of local, physical, ones. This encourages customers to outsource their applications and services to the cloud. The migration of both data and applications outside the administrative domain of customers into a shared environment imposes transversal, functional problems across distinct platforms and technologies. This article provides a contemporary discussion of the most relevant functional problems associated with the current evolution of Cloud Computing, mainly from the network perspective. The paper also gives a concise description of Cloud Computing concepts and technologies. It starts with a brief history about cloud computing, tracing its roots. Then, architectural models of cloud services are described, and the most relevant products for Cloud Computing are briefly discussed along with a comprehensive literature review. The paper highlights and analyzes the most pertinent and practical network issues of relevance to the provision of high-assurance cloud services through the Internet, including security. Finally, trends and future research directions are also presented
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Analog Computing using 1T1R Crossbar Arrays
Memristor is a novel passive electronic device and a promising candidate for new generation non-volatile memory and analog computing. Analog computing based on memristors has been explored in this study. Due to the lack of commercial electrical testing instruments for those emerging devices and crossbar arrays, we have designed and built testing circuits to implement analog and parallel computing operations. With the setup developed in this study, we have successfully demonstrated image processing functions utilizing large memristor crossbar arrays. We further designed and experimentally demonstrated the first memristor based field programmable analog array (FPAA), which was successfully configured for audio equalizer and frequency classifier demonstration as exemplary applications of such memristive FPAA (memFPAA)
New Optimal High Efficiency Dsp-based Digital Controller Design For Super High-speed Permanent Magnet Synchronous Motor
This dissertation investigates digital controller and switch mode power supply design for super high-speed permanent magnet synchronous motors (PMSM). The PMSMs are a key component for the miniaturic cryocooler that is currently under development at the University of Central Florida with support from NASA Kennedy Space Center and the Florida Solar Energy Center. Advanced motor design methods, control strategies, and rapid progress in semiconductor technology enables production of a highly efficient digital controller. However, there are still challenges for such super high-speed controller design because of its stability, high-speed, variable speed operation, and required efficiency over a wide speed range. Currently, limited research, and no commercial experimental analysis, is available concerning such motors and their control system design. The stability of a super high-speed PMSM is an important issue particularly for open-loop control, given that PMSM are unstable after exceeding a certain applied frequency. In this dissertation, the stability of super high-speed PMSM is analyzed and some design suggestions are given to maximize this parameter. For ordinary motors, the V/f control curve is a straight line with a boost voltage because the stator resistance is negligible and only has a significant effect around the DC frequency. However, for the proposed super high-speed PMSM the situation is quite different because of the motor\u27s size. The stator resistance is quite large compared with the stator reactive impedance and cannot be neglected when employing constant a V/f control method. The challenge is to design an optimal constant V/f control scheme to raise efficiency with constant V/f control. In the development, test systems and prototype boards were built and experimental results confirmed the effectiveness of the dissertation system
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Improving Computer Network Operations Through Automated Interpretation of State
Networked systems today are hyper-scaled entities that provide core functionality for distributed services and applications spanning personal, business, and government use. It is critical to maintain correct operation of these networks to avoid adverse business outcomes. The advent of programmable networks has provided much needed fine-grained network control, enabling providers and operators alike to build some innovative networking architectures and solutions. At the same time, they have given rise to new challenges in network management. These architectures, coupled with a multitude of devices, protocols, virtual overlays on top of physical data-plane etc. make network management a highly challenging task. Existing network management methodologies have not evolved at the same pace as the technologies and architectures. Current network management practices do not provide adequate solutions for highly dynamic, programmable environments. We have a long way to go in developing management methodologies that can meaningfully contribute to networks becoming self-healing entities. The goal of my research is to contribute to the design and development of networks towards transforming them into self-healing entities.
Network management includes a multitude of tasks, not limited to diagnosis and troubleshooting, but also performance engineering and tuning, security analysis etc. This research explores novel methods of utilizing network state to enhance networking capabilities. It is constructed around hypotheses based on careful analysis of practical deficiencies in the field. I try to generate real-world impact with my research by tackling problems that are prevalent in deployed networks, and that bear practical relevance to the current state of networking. The overarching goal of this body of work is to examine various approaches that could help enhance network management paradigms, providing administrators with a better understanding of the underlying state of the network, thus leading to more informed decision-making. The research looks into two distinct areas of network management, troubleshooting and routing, presenting novel approaches to accomplishing certain goals in each of these areas, demonstrating that they can indeed enhance the network management experience
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