1,783 research outputs found
Managing and Improving Upon Bandwidth Challenges in Computer Network
Managing the bandwidth of a computer network is always faced with great challenges. This research was
necessitated by the urgent need to manage the University network currently experiencing congestion in both the
local LA� and on the internet backhaul with a view to improving network performance and reduce the huge
recurrent on the WA� link. However, there exists various ways that have been deployed towards solving these
problems. In this paper we examined existing bandwidth management, effect of limited bandwidth on the
network performance and profound solutions of techniques that enhanced or improved the bandwidth efficiency.
Also, included in this research work are the studies of the effect of limited bandwidth on work load, type of
protocol used and the effect of network congestion on the quality of service of a Wide Area �etwork (WA�). By
comparison, from the modeling of the effect of work load and limited bandwidth on the throughput of a wide
area network based on experimental simulation and real time simulation scenarios, some observations were
made and recommendation of solutions were given from the analyzed results
Physics practicals for distance education in an undergraduate engineering course
BACKGROUND : Providing engineering practicals to undergraduates by means of distance education is a significant challenge. The past 30 years have seen the rapid development of the distance education. For many years, Deakin University has offered a full Bachelor of Engineering degree programme via distance education. All first-year students study a unit in physics. This unit includes practicals. Providing practical experiences to students is distance education’s greatest challenge.PURPOSE : The purpose of this work was to develop the means for off-campus students to complete practical exercises in first-year engineering physics. The solution to the problem also had to comply with accreditation requirements set by Engineers Australia.METHOD : The long-term solution to the problem was running on-campus lab classes either on weekends or as part of the annual first-year residential school for engineering professional practice. Students work was assessed by means of standard laboratory reports. On-campus marks and off-campus lab marks have been collected and compared over the past 12 years.RESULTS : The results indicate that the off-campus lab experience is similar to the on-campus experience. Marks for the two cohorts were comparable. Those few students who completed their pracs at home faced and overcame significant challenges.CONCLUSIONS : We found that performance in their lab reports for off-campus students was similar to that of the on-campus students. Accreditation requirements has shifted the focus from developing activities that students could perform at home to offering timely and efficient on-campus lab classes for off-campus students. Future work will focus on on-campus lab classes in accordance with accreditation requirements and perhaps on-line broadcasts of prac classes for those students who cannot attend lab on-campus
Flight Investigation of Longitudinal Stability and Control Characteristics and Stalling Characteristics of a C-54D Airplane
Geographic Analysis of Alcohol-Related Crashes in Nine High-Need Louisiana Parishes
This report examines nine Louisiana communities and their alcohol availability concerns from a public health perspective. The nine communities are part of The Louisiana Partnership for Success II (LPFS ll), a 5-year Substance Abuse and Mental Health Services Administration (SAMHSA) grant. The LPFS ll grant is focused exclusively on addressing underage drinking behaviors, consequences, and risk factors among 9 to 20-year-olds in nine high-need, parish-level communities (HNCs) (Louisiana Department of Health [LDH], 2020a). Communities were selected through a data-driven, participatory process and supported to form a cross-sector coalition to implement interventions within those communities. The process for choosing the high-need communities included seven indicators from the Caring Communities Youth Survey (CCYS) (LDH, 2020b), alcohol-related crash reports, and student alcohol-related suspensions. Three additional indicators were taken from the 2018 County Health Rankings (University of Wisconsin Population Health Institute, 2018) and The Centers for Disease Control and Prevention (CDC) 1991-2017 High School Youth Risk Behavior Survey Data (CDC, 2018). In order to assist these communities with high rates of alcohol-related public health issues, this research project examined the interaction of alcohol outlets, alcohol-related motor vehicle crashes (MVC), and associated demographics and time variables using GIS mapping in order to help with planning the most appropriate and impactful interventions
Proteomic Analysis of a Noninvasive Human Model of Acute Inflammation and Its Resolution: The Twenty-one Day Gingivitis Model
The 21-day experimental gingivitis model, an established noninvasive model of inflammation in response to increasing bacterial accumulation in humans, is designed to enable the study of both the induction and resolution of inflammation. Here, we have analyzed gingival crevicular fluid, an oral fluid comprising a serum transudate and tissue exudates, by LC−MS/MS using Fourier transform ion cyclotron resonance mass spectrometry and iTRAQ isobaric mass tags, to establish meta-proteomic profiles of inflammation-induced changes in proteins in healthy young volunteers. Across the course of experimentally induced gingivitis, we identified 16 bacterial and 186 human proteins. Although abundances of the bacterial proteins identified did not vary temporally, Fusobacterium outer membrane proteins were detected. Fusobacterium species have previously been associated with periodontal health or disease. The human proteins identified spanned a wide range of compartments (both extracellular and intracellular) and functions, including serum proteins, proteins displaying antibacterial properties, and proteins with functions associated with cellular transcription, DNA binding, the cytoskeleton, cell adhesion, and cilia. PolySNAP3 clustering software was used in a multilayered analytical approach. Clusters of proteins that associated with changes to the clinical parameters included neuronal and synapse associated proteins
A search for L dwarf binary systems
We present analysis of HST Planetary Camera images of twenty L dwarfs
identified in the course of the Two Micron All-Sky Survey. Four of the targets
have faint, red companions at separations between 0.07 and 0.29 arcseconds (1.6
to 7.6 AU). In three cases, the bolometric magnitudes of the components differ
by less than 0.3 magnitudes. Since the cooling rate for brown dwarfs is a
strong function of mass, similarity in luminosities implies comparable masses.
The faint component in the 2M0850 system, however, is over 1.3 magnitudes
fainter than the primary in the I-band, and ~0.8 magnitudes fainter in M(bol).
Indeed, 2M0850B is ~0.8 magnitudes fainter in I than the lowest luminosity L
dwarf currently known, while the absolute magnitude we deduce at J is almost
identical with M_J for Gl 229B. Theoretical models indicate a mass ratio of
\~0.75. The mean separation of the L dwarf binaries in the current sample is
smaller by a factor of two than amongst M dwarfs. We discuss the implications
of these results for the temperature scale in the L/T transition region and for
the binary frequency amongst L dwarfs.Comment: 38 pages, 11 figures; accepted for A
Positive-Buoyancy Rover for Under Ice Mobility
A buoyant rover has been developed to traverse the underside of ice-covered lakes and seas. The rover operates at the ice/water interface and permits direct observation and measurement of processes affecting freeze- over and thaw events in lake and marine environments. Operating along the 2- D ice-water interface simplifies many aspects of underwater exploration, especially when compared to submersibles, which have difficulty in station-keeping and precision mobility. The buoyant rover consists of an all aluminum body with two aluminum sawtooth wheels. The two independent body segments are sandwiched between four actuators that permit isolation of wheel movement from movement of the central tether spool. For normal operations, the wheels move while the tether spool feeds out line and the cameras on each segment maintain a user-controlled fixed position. Typically one camera targets the ice/water interface and one camera looks down to the lake floor to identify seep sources. Each wheel can be operated independently for precision turning and adjustments. The rover is controlled by a touch- tablet interface and wireless goggles enable real-time viewing of video streamed from the rover cameras. The buoyant rover was successfully deployed and tested during an October 2012 field campaign to investigate methane trapped in ice in lakes along the North Slope of Alaska
Non-detection of previously reported transits of HD 97658b with MOST photometry
The radial velocity-discovered exoplanet HD 97658b was recently announced to
transit, with a derived planetary radius of 2.93 \pm 0.28 R_{Earth}. As a
transiting super-Earth orbiting a bright star, this planet would make an
attractive candidate for additional observations, including studies of its
atmospheric properties. We present and analyze follow-up photometric
observations of the HD 97658 system acquired with the MOST space telescope. Our
results show no transit with the depth and ephemeris reported in the
announcement paper. For the same ephemeris, we rule out transits for a planet
with radius larger than 2.09 R_{Earth}, corresponding to the reported 3\sigma
lower limit. We also report new radial velocity measurements which continue to
support the existence of an exoplanet with a period of 9.5 days, and obtain
improved orbital parameters.Comment: 16 pages, 4 figures; 1 Table; accepted for publication in ApJL,
includes changes made in response to the referee repor
BUMPER v1.0: a Bayesian user-friendly model for palaeo-environmental reconstruction
We describe the Bayesian user-friendly model for palaeo-environmental reconstruction (BUMPER), a Bayesian transfer function for inferring past climate and other environmental variables from microfossil assemblages. BUMPER is fully self-calibrating, straightforward to apply, and computationally fast, requiring ~2 s to build a 100-taxon model from a 100-site training set on a standard personal computer. We apply the model’s probabilistic framework to generate thousands of artificial training sets under ideal assumptions.We then use these to demonstrate the sensitivity of reconstructions to the characteristics of the training set, considering assemblage richness, taxon tolerances, and the number of training sites. We find that a useful guideline for the size of a training set is to provide, on average, at least 10 samples of each taxon. We demonstrate general applicability to real data, considering three different organism types (chironomids, diatoms, pollen) and different reconstructed variables. An identically configured model is used in each application, the only change being the input files that provide the training-set environment and taxon-count data. The performance of BUMPER is shown to be comparable with weighted average partial least squares (WAPLS) in each case. Additional artificial datasets are constructed with similar characteristics to the real data, and these are used to explore the reasons for the differing performances of the different training sets
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