949 research outputs found
JME 4110 Final Report - Umbrella Actuator
The intention of this project was to improve upon the current methods of actuation required to open and close large patio umbrellas. We have created a prototype that utilizes the assistance of a gas spring enclosed in the umbrella pole to provide the force necessary to open the umbrella while minimizing the force required to close it. This was accomplished through the alteration of an existing, easily purchased, umbrella with a hollow steel pole and the introduction of a low cost gas assist spring. Through the alterations to the pole, and umbrella itself, we were able to attach an internal extension from the canopy hub that coupled with our gas spring. At this coupling location a handle was attached which allows the user actuation of the umbrellas
Behavior of early warnings near the critical temperature in the two-dimensional Ising model
Among the properties that are common to complex systems, the presence of
critical thresholds in the dynamics of the system is one of the most important.
Recently, there has been interest in the universalities that occur in the
behavior of systems near critical points. These universal properties make it
possible to estimate how far a system is from a critical threshold. Several
early-warning signals have been reported in time series representing systems
near catastrophic shifts. The proper understanding of these early-warnings may
allow the prediction and perhaps control of these dramatic shifts in a wide
variety of systems. In this paper we analyze this universal behavior for a
system that is a paradigm of phase transitions, the Ising model. We study the
behavior of the early-warning signals and the way the temporal correlations of
the system increase when the system is near the critical point.Comment: 20 pages, 8 figures, Submitted to PLOS ONE on Oct. 20th 2014.
PONE-D-14-4718
Contribution to the Improvement of the Correlation Filter Method for Modal Analysis with a Spatial Light Modulator
Modal decomposition of light is essential to study its propagation properties in waveguides and photonic devices. Modal analysis can be carried out by implementing a computer-generated hologram acting as a match filter in a spatial light modulator. In this work, a series of aspects to be taken into account in order to get the most out of this method are presented, aiming to provide useful operational procedures. First of all, a method for filter size adjustment based on the standard fiber LP-mode symmetry is presented. The influence of the mode normalization in the complex amplitude encoding-inherent noise is then investigated. Finally, a robust method to measure the phase difference between modes is proposed. These procedures are tested by wavefront reconstruction in a conventional few-mode fiber
Spectrum Coexistence of LEO and GSO Networks: An Interference-Based Design Criteria for LEO Inter-Satellite Links
As small satellites become more capable through miniaturized electronics and on-board processing, constellations of low-cost satellites lunched in Low- Earth Orbit (LEO) become feasible. The increase in the number of LEO satellites drives the need for frequency coexistence between the LEO constellation systems with the already existing geostationary (GSO) satellite networks. In this context, it is crucial to design the communication links paying special attention to interference analysis.
This is particularly true when the LEO satellite constellation exploit inter-satellite communication links (ISL). In this paper, a radio frequency interference analysis based on simulation of the dynamic satellite constellation is presented and the design parameters of the inter-satellite links are analyzed. The results suggest that carefully choosing the design parameters of the intersatellite links, spectrum coexistence of LEO and GSO networks may be possible.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Spectrum Coexistence of LEO and GSO Networks: An Interference-Based Design Criteria for LEO Inter-Satellite Links
As small satellites become more capable through miniaturized electronics and on-board processing, constellations of low-cost satellites lunched in Low- Earth Orbit (LEO) become feasible. The increase in the number of LEO satellites drives the need for frequency coexistence between the LEO constellation systems with the already existing geostationary (GSO) satellite networks. In this context, it is crucial to design the communication links paying special attention to interference analysis.
This is particularly true when the LEO satellite constellation exploit inter-satellite communication links (ISL). In this paper, a radio frequency interference analysis based on simulation of the dynamic satellite constellation is presented and the design parameters of the inter-satellite links are analyzed. The results suggest that carefully choosing the design parameters of the intersatellite links, spectrum coexistence of LEO and GSO networks may be possible.Sociedad Argentina de Informática e Investigación Operativa (SADIO
Contribution to the Improvement of the Correlation Filter Method for Modal Analysis with a Spatial Light Modulator
Modal decomposition of light is essential to study its propagation properties in waveguides
and photonic devices. Modal analysis can be carried out by implementing a computer-generated
hologram acting as a match filter in a spatial light modulator. In this work, a series of aspects to
be taken into account in order to get the most out of this method are presented, aiming to provide
useful operational procedures. First of all, a method for filter size adjustment based on the standard
fiber LP-mode symmetry is presented. The influence of the mode normalization in the complex
amplitude encoding-inherent noise is then investigated. Finally, a robust method to measure the phase
difference between modes is proposed. These procedures are tested by wavefront reconstruction in a
conventional few-mode fiber
The Tone from Above:The Effect of Communicating a Supportive Regulatory Strategy on Reporting Quality
In collaboration with the Authority for the Financial Markets in the Netherlands, we manipulate the content of official letters that instruct financial intermediaries to submit a mandatory self-assessment. As part of the Registered Report Process, we submitted our hypotheses, experimental procedure, and planned statistical analyses before data collection. We predicted that a request indicating a supportive regulatory attitude has a positive effect on reporting quality on average. We also predicted this effect to be stronger for small firms and for firms with a long-term orientation, and to become negative for firms with a short-term orientation. Planned analyses show that a supportive letter reduced reporting quality unless firms had a long-term orientation, supporting the moderating influence of time horizon, but providing no support for the expected average effect or for moderation by firm size
Hot topics, urgent priorities, and ensuring success for racial/ethnic minority young investigators in academic pediatrics.
BackgroundThe number of racial/ethnic minority children will exceed the number of white children in the USA by 2018. Although 38% of Americans are minorities, only 12% of pediatricians, 5% of medical-school faculty, and 3% of medical-school professors are minorities. Furthermore, only 5% of all R01 applications for National Institutes of Health grants are from African-American, Latino, and American Indian investigators. Prompted by the persistent lack of diversity in the pediatric and biomedical research workforces, the Academic Pediatric Association Research in Academic Pediatrics Initiative on Diversity (RAPID) was initiated in 2012. RAPID targets applicants who are members of an underrepresented minority group (URM), disabled, or from a socially, culturally, economically, or educationally disadvantaged background. The program, which consists of both a research project and career and leadership development activities, includes an annual career-development and leadership conference which is open to any resident, fellow, or junior faculty member from an URM, disabled, or disadvantaged background who is interested in a career in academic general pediatrics.MethodsAs part of the annual RAPID conference, a Hot Topic Session is held in which the young investigators spend several hours developing a list of hot topics on the most useful faculty and career-development issues. These hot topics are then posed in the form of six "burning questions" to the RAPID National Advisory Committee (comprised of accomplished, nationally recognized senior investigators who are seasoned mentors), the RAPID Director and Co-Director, and the keynote speaker.Results/conclusionsThe six compelling questions posed by the 10 young investigators-along with the responses of the senior conference leadership-provide a unique resource and "survival guide" for ensuring the academic success and optimal career development of young investigators in academic pediatrics from diverse backgrounds. A rich conversation ensued on the topics addressed, consisting of negotiating for protected research time, career trajectories as academic institutions move away from an emphasis on tenure-track positions, how "non-academic" products fit into career development, racism and discrimination in academic medicine and how to address them, coping with isolation as a minority faculty member, and how best to mentor the next generation of academic physicians
Fault Tolerant Control in a Semi-active Suspension
6 pagesInternational audienceA Fault Tolerant Control System (FTCS) in a Quarter of Vehicle (QoV ) model is proposed. The control law is time-varying using a Linear Parameter-Varying (LPV ) based controller, which includes two scheduling parameters. One parameter for monitoring the nonlinear behavior of the damper, and another for fault accommodation using a reference model obtained by a state observer of the normal operating regime. The QoV model represents a semi-active suspension, including an experimental magneto-rheological damper model. The FTCS is analyzed when the velocity sensor fails abruptly and the QoV model is susceptible to disturbances in the road pro le. Simulation results show the e ectiveness of the FTCS in terms of vehicle comfort, suspension detection and road holding in comparison with a conventional LPV based control system. In the FTCS, the comfort index based on the power spectral density is within the desirable bound (1.8) in all range of frequencies, once the sensor fault has occurred; while, the conventional control system deteriorates the comfort 54 %, specially at low frequencies (0-4 Hz). Additionally, the FTCS improves the road holding and suspension de ection indexes, 33% and 39% respectively, when the fault accommodation is considered
The Complete Structure of the Core Oligosaccharide from Edwardsiella tarda EIB 202 Lipopolysaccharide
The chemical structure and genomics of the lipopolysaccharide (LPS) core oligosaccharide of pathogenic Edwardsiella tarda strain EIB 202 were studied for the first time. The complete gene assignment for all LPS core biosynthesis gene functions was acquired. The complete structure of core oligosaccharide was investigated by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, electrospray ionization mass spectrometry MSn, and matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry. The following structure of the undecasaccharide was established: The heterogeneous appearance of the core oligosaccharide structure was due to the partial lack of β-d-Galp and the replacement of α-d-GlcpNAcGly by α-d-GlcpNGly. The glycine location was identified by mass spectrometry
- …