161 research outputs found
Application Benchmarks for SCMP: Single Chip Message-Passing Computer
No full textAs transistor feature sizes continue to shrink, it will become feasible, and for a number of reasons more efficient, to include multiple processors on a single chip. The SCMP system being developed at Virginia Tech includes up to 64 processors on a chip, connected in a 2-D mesh. On-chip memory is included with each processor, and the architecture includes support for communication and the execution of parallel threads. As with any new computer architecture, benchmark kernels and applications are needed to guide the design and development, as well as to quantify the system performance. This thesis presents several benchmarks that have been developed for or ported to SCMP. Discussion of the benchmark algorithms and their implementations is included, as well as an analysis of the system performance. The thesis also includes discussion of the programming environment available for developing parallel applications for SCMP.Master of Scienc
Inter-operator resource sharing in 4G LTE cellular networks
No full textThe dramatic increase in wireless data traffic challenges cellular network operators to increase wireless access and system capacity, and to reduce costs of deploying and operating the network infrastructure. In light of the cost and complexity of large scale networks as well as the absence of new spectrum, the paradigm of resource sharing is explored to address these challenges. In this research, we examine three cellular resource sharing approaches: Capacity, Spectrum and Infrastructure Hardware and propose various sharing options in the context of 4G LTE. We propose a unified coordinated sharing process and architecture by introducing a new network Sharing Entity (SE). The SE enables dynamic creation, modification and termination of resource sharing agreements among operator that can be conditional or restrictive in time, space and other dimensions. We present the required technologies in two cases: (1) Traditional infrastructure for capacity and spectrum sharing options wherein the networks of operators participating in sharing are physically independent infrastructures. (2) Virtualized infrastructure for hardware sharing option wherein a single physical infrastructure virtualizes infrastructures of participating operators. We model two geographically overlapped LTE cellular networks, operated by two operators, with the proposed sharing architecture and process. We evaluate sharing options based on multiple performance metrics and cost saving estimates under light, moderate and heavy loading scenarios via simulations in collocated and non-collected deployment topologies.Ph. D.Includes bibliographical referencesIncludes vitaby Jignesh S. Pancha
Diversity oriented design of various hydrazides and their in vitro evaluation against Mycobacterium tuberculosis H37Rv strains
No full textControl and prevention of tuberculosis is a major challenge, as one-third of the world’s population is infected with Mycobacterium tuberculosis. The resurgence of tuberculosis and the emergence of multidrug-resistance strains of mycobacteria, necessitate the search for new class of antimycobacterial agents. As a part of investigation of new antitubercular agents in this laboratory, we describe the syntheses of various hydrazides of comarins, quinolones and pyrroles and screening against M. tuberculosis (Mtb) H37Rv by using rifampin as a standard drug. Among the designed molecules, the most prominent compounds 2a–g, 4a and 9a showed >90% GI at MIC <6.25 μg/mL. Finally, these studies suggests that compounds 2a–g, 4a and 9a may serve as promising lead scaffolds for further generation of new anti-TB agents
Multi-Purpose Chest X-Ray Analytics System Using Deep Learning Techniques
No full textThere has been rapid and tremendous progress in the past few years in the field of deep learning, mainly due to the availability of computational power and the vast amount of data. Deep neural networks have resulted in state-of-the-art performances in classification, detection, and segmentation in comparison to previous shallow methodologies built upon hand-crafted image features. This progress has yielded a rise in performance of medical imaging analysis as well. Chest X-ray imaging is one of the most accessible medical imaging technique for diagnosis of multiple diseases. With the availability of ChestX-ray14, which is a massive dataset of chest X-ray images, we can use deep learning techniques for various tasks like classification, detection, segmentation, etc. This thesis explores deep learning techniques such as convolutional neural networks and generative adversarial networks for applications of content-based image retrieval, image generation for different pathologies, and recognition of pathologies in chest X-rays.Electrical and Computer Engineering, Department o
A Practical ECG Criterion to Unmask Left Accessory AV Connections in Patients With Subtle Preexcitation
No full textAccessory AV-connections capable of antegrade conduction need to be recognized because of the potential for life-threatening arrhythmias. However, the preexcited ECG pattern may be subtle, especially among left-sided AV-connections. We explored whether additional ECG criteria might help identify left-sided AV-connections
Water consumption for steam methane reforming hydrogen plants in Edmonton, Canada
No full textTraditional engineering and financial assessments are limited not only to consideration of currently internalized costs, but also often lack consideration of new or current externalities during the life of the new system. The goal of this thesis is to provide a methodology that integrates sustainability assessment with the traditional assessments, thereby allowing the assessment and optimization of the total overall costs. The proposed method is applied for the steam methane reforming (SMR) plants operated by Air Products in Edmonton, Canada where the boiler feed water for hydrogen manufacturing is produced using the polished effluent from the local municipal wastewater treatment plant. The softening of the feed water to Reverse Osmosis (RO) system is proposed (after evaluating the several options) to improve the recovery for the current RO system from 75% to 95%. The overall costs were estimated for comparison of the current and proposed systems. The production of hydrogen via SMR highlights the complexities of the sustainability assessment. While hydrogen may be considered a renewable transportation fuel, depending on whether the fossil natural gas can be replaced with renewable biogas or via electrolysis of water using renewable energy, it is reliant on the availability of water. However, water is a scarce resource that is also essential for basic human survival and ecological needs. As the population of the world increases, alternative water sources need to be explored, which may require more energy in the processing of such water to potable grade. The results show that the proposed RO feed softening via Ion Exchange (IX) can improve RO recovery up to 95%. The financial assessments based on literature prices and cost factors show that the current operating cost can be reduced up to ~20% by improving RO recovery to 95% with ~75% probability for cost reduction at 95% recovery. When the capital costs are accounted for, NPV-based analyses show that for 95% recovery more than 20% IRR (if spare vessels are available for refurbishment) could be achieved. Environmental assessments (Life Cycle Assessment method using SimaPro v7.3 following ISO 14040-44 standards) show that 1.12 x 10-3 ReCiPe Endpoints impact for current RO operation at 75% recovery can be reduced by ~8% when 95% RO recovery is achieved via the proposed system. Due to the need for increased NaCl salt for regeneration of resins in the proposed system, the environmental impacts increased for metal depletion and ionizing radiation impact categories, unlike the other impact categories. The GHG emissions could be reduced by ~10% (after accounting for 10%-30% probability) for 95% RO recovery with the reduction from the reduced consumption of inputs. Similarly, the life cycle water depletion impacts can be reduced by ~10% (after accounting for 30%-65% reduction probability) from the current 1.75kg water depletion per kg of BFW produced. Water Footprint Assessment (WFA) as per the Ridoutt & Pfister method shows that when accounted for local water stress, during the worst month, the blue water footprint increases from 1.75kg/kg BFW to 63.9kg/kg BFW, in addition to ~0.08kg/kg BFW greywater footprint. The social assessment shows mixed results with lower employment, employee development, corporate philanthropy, environmental "protect" spend and R&D spend due to reduced overall consumptions for the 95% recovery option. The other social impact categories were improved for 95% recovery. The overall cost (estimated as the sum of the internally normalized social costs) were 3.0 units with up to 35% reduction potential. The results of the case study show that IX feed softening has potential to not only reduce the environmental and social costs, but also meet the financial constraints. Also, this highlights that an integrated sustainability assessment method that evaluates and combines all three aspects of sustainability - environment, social and economic - could be developed. The proposed method as presented needs further development. Among other things, the lack of availability of robust social inventory database significantly hinders the development and adoption such integrated methods. The application of the method to additional case studies would be a good next step. This exercise has highlighted that the value and benefits of overall cost estimates are beyond those of policy making by the regulatory agencies. Sustainability minded companies could benefit from having environmental and social goals along with the financial targets as they understand the risks from inadequate performances in any of these aspects. However, these goals are typically on a gate-to-gate basis and independent of each other; thereby, creating the potential for shifting burdens in the value chain and not obtaining the full benefits of risk mitigation. The assessment using the overall cost approach at life cycle basis is essential for industry in not only risk mitigation, but also opportunity identification at an early stage
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Ultrasound and photoacoustic imaging to guide and monitor photothermal therapy
No full texttextPhotothermal cancer therapy is a potential alternative to surgery and involves selective tissue destruction using thermal energy. Targeted photoabsorbers, used in conjunction with matching a continuous wave laser, make photothermal therapy both noninvasive and tumor-specific. However, to become clinically relevant, there is a need to develop an imaging technique to identify tissue composition and to detect the presence of photoabsorbers in the tumor volume before therapy; to monitor the temperature rise during therapy; and to assess the tumor damage after therapy. In this study, a combined ultrasound and photoacoustic imaging system was designed to assist photothermal therapy. The imaging system was tested on tissue mimicking phantoms, ex-vivo porcine tissue samples, ex-vivo mice and in-vivo mice. First, ultrasound imaging was utilized to differentiate between water-based and lipidbearing tissue. A combined ultrasound and photoacoustic imaging system was then assembled to identify the presence and spatial location of gold nanoparticles. Multiwavelength photoacoustic imaging was used to further confirm the presence of nanoparticles. Temperature monitoring algorithms, using both temperature-dependent time shifts in ultrasound signals and amplitude changes in photoacoustic signals, were developed. Finally, photothermal therapy was carried out on tumor-bearing nude mice using in-vivo ultrasound and photoacoustic imaging to identify the tumor boundary, detect the nanoparticles and monitor the temperature elevation. The results of the studies show that ultrasound and photoacoustic imaging provide complementary and clinically relevant information. Overall, there is potential of using the ultrasound and photoacoustic imaging system to plan, guide and monitor photothermal therapy.Biomedical Engineerin
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