3,981 research outputs found
Dynamically Reconfigurable Systolic Array Accelerators: A Case Study with Extended Kalman Filter and Discrete Wavelet Transform Algorithms
Field programmable grid arrays (FPGA) are increasingly being adopted as the primary on-board computing system for autonomous deep space vehicles. There is a need to support several complex applications for navigation and image processing in a rapidly responsive on-board FPGA-based computer. This requires exploring and combining several design concepts such as systolic arrays, hardware-software partitioning, and partial dynamic reconfiguration. A microprocessor/co-processor design that can accelerate two single precision oating-point algorithms, extended Kalman lter and a discrete wavelet transform, is presented. This research makes three key contributions. (i) A polymorphic systolic array framework comprising of recofigurable partial region-based sockets to accelerate algorithms amenable to being mapped onto linear systolic arrays. When implemented on a low end Xilinx Virtex4 SX35 FPGA the design provides a speedup of at least 4.18x and 6.61x over a state of the art microprocessor used in spacecraft systems for the extended Kalman lter and discrete wavelet transform algorithms, respectively. (ii) Switchboxes to enable communication between static and partial reconfigurable regions and a simple protocol to enable schedule changes when a socket\u27s contents are dynamically reconfigured to alter the concurrency of the participating systolic arrays. (iii) A hybrid partial dynamic reconfiguration method that combines Xilinx early access partial reconfiguration, on-chip bitstream decompression, and bitstream relocation to enable fast scaling of systolic arrays on the PolySAF. This technique provided a 2.7x improvement in reconfiguration time compared to an o-chip partial reconfiguration technique that used a Flash card on the FPGA board, and a 44% improvement in BRAM usage compared to not using compression
On-Campus Versus Off-Campus: A Comparative Analysis Of MBA Learning Outcomes For A Classroom-Based Program
Both direct and indirect measures of learning outcomes provide data that can be used to improve learning. The research reports a study of an indirect measure of learning outcomes in an MBA program. The measure was a Post-Then format using a five point Likert scale. Thirteen courses were analyzed generating 107,440 responses over a 5-year period. Two research questions were addressed: Are MBA students learning as demonstrated by an improvement in learning outcomes? and, Is there a difference in learning outcomes for on-campus versus off-campus students? Results are presented and future research directions are offered
The Many Faces of Interleukin-6: The Role of IL-6 in Inflammation, Vasculopathy, and Fibrosis in Systemic Sclerosis
Interleukin-6 is currently attracting significant interest as a potential therapeutic target in systemic sclerosis (SSc). In this paper, the biology of interleukin-6 is reviewed, and the evidence for interleukin-6 dysregulation in SSc is explored. The role of inteleukin-6 classical and trans signalling pathways in SSc relevant phenomena such as chronic inflammation, autoimmunity, endothelial cell dysfunction, and fibrogenesis is discussed. The existing evidence that interventions designed to block interleukin-6 signalling are of therapeutic relevance in SSc is evaluated
An Examination Of Kolb's Learning Style Inventory
As educators our primary focus is that of ensuring that students experience positive learning outcomes. Research, however, has shown that there are differences in students learning styles and that these differences will impact on the overall learning process. One way of ensuring that these positive outcomes are achieved is by identifying the different learning styles of students and modifying our teaching methodology to meeting those needs. This paper examines Kolbs (1984) Learning Style Inventory and provides suggestions on how to address the different students learning styles in order to enhance the learning process
Thermally Activated Magnetization and Resistance Decay during Near Ambient Temperature Aging of Co Nanoflakes in a Confining Semi-metallic Environment
We report the observation of magnetic and resistive aging in a self assembled
nanoparticle system produced in a multilayer Co/Sb sandwich. The aging decays
are characterized by an initial slow decay followed by a more rapid decay in
both the magnetization and resistance. The decays are large accounting for
almost 70% of the magnetization and almost 40% of the resistance for samples
deposited at 35 . For samples deposited at 50 the magnetization
decay accounts for of the magnetization and 50% of the resistance.
During the more rapid part of the decay, the concavity of the slope of the
decay changes sign and this inflection point can be used to provide a
characteristic time. The characteristic time is strongly and systematically
temperature dependent, ranging from x at 400K to x at 320K in samples deposited at . Samples deposited at 50
displayed a 7-8 fold increase in the characteristic time (compared to the samples) for a given aging temperature, indicating that this timescale may
be tunable. Both the temperature scale and time scales are in potentially
useful regimes. Pre-Aging, Scanning Tunneling Microscopy (STM) reveals that the
Co forms in nanoscale flakes. During aging the nanoflakes melt and migrate into
each other in an anisotropic fashion forming elongated Co nanowires. This aging
behavior occurs within a confined environment of the enveloping Sb layers. The
relationship between the characteristic time and aging temperature fits an
Arrhenius law indicating activated dynamics
Fusion of inclusions following superinfection of HeLa cells by two serovars of Chlamydia trachomatis.
We used a double-label immunofluorescence assay to examine the ability of Chiamydia trachomatis serovar
F to infect and develop within HeLa 229 cells previously infected with serovar E. No exclusion to superinfection
occurred for up to 24 h following infection by serovar E. The percentage of HeLa cells infected in cultures
inoculated with both strains was identical to that of cells in cultures inoculated with one strain as a control.
Organisms of both serovars were located within the same intracellular inclusion in 88 to 95% of HeLa cells
infected with both serovars. The proportion of superinfected HeLa cells containing both strains in separate
inclusions increased when there was exposure to inhibitors of cytoskeletal structure and transport. We used this
inhibition to demonstrate that fusion of C. trachomatis phagosomes occurs throughout the developmental cycle
Humidifier Development and Applicability to the Next Generation Portable Life Support System
A development effort at the NASA Johnson Space Center investigated technologies to determine whether a humidifier would be required in the Portable Life Support System (PLSS) envisioned for future exploration missions. The humidifier has been included in the baseline PLSS schematic since performance testing of the Rapid Cycle Amine (RCA) indicates that the RCA over-dries the ventilation gas stream. Performance tests of a developmental humidifier unit and commercial off-the-shelf (COTS) units were conducted in December 2009. Following these tests, NASA revisited the need for a humidifier via system analysis. Results of this investigation indicate that it is feasible to meet humidity requirements without the humidifier if other changes are made to the PLSS ventilation loop and the Liquid Cooling and Ventilation Garment (LCVG)
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