2,710 research outputs found
Techniques for Forecasting the Cessation of Lightning at Cape Canaveral Air Station and the Kennedy Space Center
The focus of this research effort is directed toward identifying new methods of forecasting the cessation of lightning along the Central Atlantic Coast of Florida. Cloud-to-ground lightning flashes place Air Force (AF) personnel and assets at risk almost daily at this location. Providing a more accurate method of forecasting the cessation of lightning would allow for safer and more efficient execution of AF operations. A data set consisting of 40 thunderstorm cases was identified within a 90 nautical miles (nmi) region surrounding the Melbourne, Florida WSR-88D (KMLB) site. Each case falls between the months of May and September and the years of 1995 through 1997. Simple and multiple linear regression models are built using this dataset. Variables included max Vertically Integrated Liquid water (VIL), max reflectivity, max peak current, peak cumulative flash rate, peak negative flash rate, and peak positive flash rate. Results indicate that three of the simple linear regression models to some extent accurately represent the data. Additionally, when the data set is separated by thunderstorm cell type (multi or single) and cell specific regressions are built, results indicate that the regressions based on the single-cell data set produce a substantial increase in forecast skill compared to that of climatology. In fact, some regressions are shown to improve forecast accuracy by 90% over that of climatology. Moreover, multiple linear regression models are shown to produce similar results and further reinforce the notion that each thunderstorm cell type (multi or single) behaves substantially different from the other with respect to forecasting the cessation of lightning
Knots and Links in Three-Dimensional Flows
The closed orbits of three-dimensional flows form knots and links. This book develops the tools - template theory and symbolic dynamics - needed for studying knotted orbits. This theory is applied to the problems of understanding local and global bifurcations, as well as the embedding data of orbits in Morse-smale, Smale, and integrable Hamiltonian flows. The necesssary background theory is sketched; however, some familiarity with low-dimensional topology and differential equations is assumed
Mining modern repositories with elasticsearch
Organizations are generating, processing, and retaining data at a rate that often exceeds their ability to analyze it effec-tively; at the same time, the insights derived from these large data sets are often key to the success of the organi-zations, allowing them to better understand how to solve hard problems and thus gain competitive advantage. Be-cause this data is so fast-moving and voluminous, it is in-creasingly impractical to analyze using traditional offline, read-only relational databases. Recently, new “big data ” technologies and architectures, including Hadoop and NoSQL databases, have evolved to better support the needs of organizations analyzing such data. In particular, Elasticsearch — a distributed full-text search engine — explicitly addresses issues of scalability, big data search, and performance that relational databases were simply never designed to support. In this paper, we reflect upon our own experience with Elasticsearch and highlight its strengths and weaknesses for performing modern mining software repositories research
Effects of a simulated motion environment upon the physical demands of heavy materials handling operators
Maritime shipping, commercial fishing, passenger and cargo shipping and offshore oil and gas industries are all major contributors to the economies of Atlantic Canada. These industries require workers to perform heavy materials handling under harsh environmental conditions, particularly extreme deck motions. The purpose of this study was to better understand the demands of a moving environment on the ability of a person to perform specific lifting tasks. -- Nineteen healthy male subjects volunteered for this study. Each subject was required to lift a 15 kg load under four lifting conditions. While performing these lifting tasks, a ship's motion simulator was used to create deck motions under foot. Three deck motions were considered: pitch, quartering and roll. A stable laboratory condition was also collected for all lifting conditions. Electromyography (EMG) histories of four muscles (erector spinae, latissimus dorsi, external oblique and trapezius) were collected bilaterally and thoracolumbar kinematics was measured throughout the experimental protocol. -- A repeated measures ANOVA was employed to assess trunk motions and muscle activities across the lifting and motion conditions. There were no significant differences found due to the motion effect for any of the muscles monitored in this study. However, the lifting task did produce differences in the EMG activities for some muscles. The maximal sagittal velocities were significantly smaller for all motion states in comparison to the stable lab condition (p≤0.01) while maximum twisting and lateral bending velocities increased in the motion conditions compared to the stable lab condition (p≤0.05). Results suggest that working in a moving environment will likely increase the operator's risk for overexertion injuries, particularly to the spine
Non--Newtonian viscosity of interacting Brownian particles: comparison of theory and data
A recent first-principles approach to the non-linear rheology of dense
colloidal suspensions is evaluated and compared to simulation results of
sheared systems close to their glass transitions. The predicted scenario of a
universal transition of the structural dynamics between yielding of glasses and
non-Newtonian (shear-thinning) fluid flow appears well obeyed, and calculations
within simplified models rationalize the data over variations in shear rate and
viscosity of up to 3 decades.Comment: 6 pages, 2 figures; J. Phys. Condens. Matter to be published (Jan.
2003
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The Foundation of and Future Directions for JEDI @ University of Massachusetts Amherst Libraries
This chapter per the authors provides an in-depth overview of how the University of Massachusetts Amherst Libraries has leveraged historical connections and special collections to provide a robust foundation for justice, equity, diversity, and inclusion programming and initiatives on campus, in the community, and worldwide. Readers will be provided with examples that will inform conversations about JEDI efforts at their own libraries and on their own campuses, as well as insights gleaned during the process of doing this work at University of Massachusetts Amherst Libraries
Critical fluctuations in cortical models near instability
Australian Research Council, the National Health and Medical Research Council, the Brain Network Recovery Group Grant JSMF22002082, and Netherlands Organization for Scientific Research (NWO #451–10-030
Modeling Treatment Strategies to Inform Yaws Eradication.
Yaws is a neglected tropical disease targeted for eradication by 2030. To achieve eradication, finding and treating asymptomatic infections as well as clinical cases is crucial. The proposed plan, the Morges strategy, involves rounds of total community treatment (i.e., treating the whole population) and total targeted treatment (TTT) (i.e., treating clinical cases and contacts). However, modeling and empirical work suggests asymptomatic infections often are not found in the same households as clinical cases, reducing the utility of household-based contact tracing for a TTT strategy. We use a model fitted to data from the Solomon Islands to predict the likelihood of elimination of transmission under different intervention schemes and levels of systematic nontreatment resulting from the intervention. Our results indicate that implementing additional treatment rounds through total community treatment is more effective than conducting additional rounds of treatment of at-risk persons through TTT
Qualitative perspectives toward prostitution's perceived lifestyle addictiveness
Background and aims:
The aim of the present study was to provide a phenomenological perspective of individuals who actively engage in street-level prostitution and identified a lifestyle addiction associated with their activities.
Methods:
We interviewed 25 women who were incarcerated in American county jails (at the time of interviews) for prostitution crimes. The transcripts were analyzed for themes that represented the shared consensus of the research participants.
Results:
Four negative psychological dynamics related to prostitution. First, participants described accounts of physical and emotional violence which they experienced at the hand of clients and others involved in the lifestyle. Second, interviewees explained an extreme dislike for their actions relating to and involving prostitution. These individuals did not describe themselves as being sexually addicted; sex was means to a desired end. Third, participants described how prostitution's lifestyle had evolved into something which they conceptualized as an addiction. As such, they did not describe themselves as feeling addicted to sex acts — but to lifestyle elements that accompanied prostitution behaviors. Finally, participants believed that freedom from prostitution's lifestyle would require social service assistance in order to overcome their lifestyle addiction.
Conclusions:
The results show that, although the prostitutes repeatedly and consistently used the term “addiction” when describing their lifestyles, they did not meet the DSM-IV-TR criteria for addiction. Rather, they shared many of the same psychological constructs as do addicts (e.g., feeling trapped, desiring escape, needing help to change), but they did not meet medical criteria for addictive dependence (e.g., tolerance or withdrawal)
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