290 research outputs found
Evaluation of electromagnetic source for ocean climate acoustic thermometry at Lake Seneca
A compact electromagnetic monopole source, requiring pressure equalization, was evaluated at the Naval Underwater Systems
Center at Lake Seneca during July 1992 by scientists from the Institute of Applied Physics of the Russian Academy of Sciences
(IAP RAS) and from the Woods Hole Oceanographic Institution and other American organizations. The titaium source was
developed at the IAP RAS. The source has a mass of 123 kg and a diameter of .54 m. The source cannot be thought of as a single
unit; rather the characteristics of the transmitted signal depend on a transmission system consisting of the source, the power
amplifier, and a computer. The computer and the amplifier send specially adapted signals to the source to produce the desired
acoustic signals. Measurements indicate the acoustic system as a center frequence of 225 Hz, a bandwidth of about 50 Hz, an
associated pulse resolution of about 0.02 s, a source level of about 198 dB re 1 μpa @ 1 m, with an efficiency of about 50%. The
system has an efficiency of about 67% near 225 Hz, the resonant frequence. The source is suitable for mounting on autonomous
ocean moorings for several years as part of a system of monitoring climatic temperature changes over basin scales.Funding was provided by the Office of Naval Research contract N00014-92-J-1222 and
the Woods Hole Oceanographic Institutio
Unlocking Feature Visualization for Deeper Networks with MAgnitude Constrained Optimization
Feature visualization has gained substantial popularity, particularly after
the influential work by Olah et al. in 2017, which established it as a crucial
tool for explainability. However, its widespread adoption has been limited due
to a reliance on tricks to generate interpretable images, and corresponding
challenges in scaling it to deeper neural networks. Here, we describe MACO, a
simple approach to address these shortcomings. The main idea is to generate
images by optimizing the phase spectrum while keeping the magnitude constant to
ensure that generated explanations lie in the space of natural images. Our
approach yields significantly better results (both qualitatively and
quantitatively) and unlocks efficient and interpretable feature visualizations
for large state-of-the-art neural networks. We also show that our approach
exhibits an attribution mechanism allowing us to augment feature visualizations
with spatial importance. We validate our method on a novel benchmark for
comparing feature visualization methods, and release its visualizations for all
classes of the ImageNet dataset on https://serre-lab.github.io/Lens/.
Overall, our approach unlocks, for the first time, feature visualizations for
large, state-of-the-art deep neural networks without resorting to any
parametric prior image model
Deep-sea corehead camera photography and piston coring
Cameras were mounted in a newly designed corehead of a piston corer and used to photograph coring operations during 36 stations on CHAIN cruise 75 and 28 stations on ATLANTIS II cruise 42. Through the analysis of these photographs, the deep-water operation of a piston corer during its descent, tripping, impact with the bottom, and ascent has been studied, providing
information on the corer's stability, effectiveness in obtaining a bottom sample, and influence on the nearby sea-floor. Accurate determinations of the amount of penetration were possible, allowing comparisons to be made with the more indirect methods of determining penetration and with the length of core recovered. Sediment clouds produced by bottom currents were noticed in many of the bottom photographs. A number of suggestions are made for future piston coring operations.
The corer descends with little rotation and swinging. Free-fall and penetration generally take place in less than 5 seconds, with a rotation of 20-60° and an increase of about 6° in vertical deviation. During penetration, the corer disturbs the surrounding sea floor, producing both mounds and depressions around the core barrels. While resting in the bottom, the corer is very stable although some wobbling does occur. Considerable rotation takes place during both pull-out and ascent; frequent sediment discharges from the piston corer occur.
No consistent relationship was found between the amount of penetration and the length of core recovered, and thus with the degree of core shortening. Comparisons between piston and pilot cores indicate that the piston cores have been shortened and disturbed relative to the pilot cores, and that as much as a meter of the upper portion of the piston core has been lost. The position of the mud-mark appears to be a reliable indicator of the amount of penetration; estimates by extrapolation of the thermal
gradient to the surface are less reliable. The vertical deviation of the corer in the bottom does not influence the amount of penetration. Stratigraphic dips in the recovered cores correspond poorly to this vertical deviation in the bottom.The National Science Foundation Grants GA-1077 and GA-1209 and submitted to the Office of Naval Research under Contract Nonr-4029(00); NR 260-101, and N00014-66-C0241; NR 083- 004
Plasmodium vivax Malaria among Military Personnel, French Guiana, 1998–2008
We obtained health surveillance epidemiologic data on malaria among French military personnel deployed to French Guiana during 1998–2008. Incidence of Plasmodium vivax malaria increased and that of P. falciparum remained stable. This new epidemiologic situation has led to modification of malaria treatment for deployed military personnel
Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases.
Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article
Le Forum, Vol. 41 No. 1
https://digitalcommons.library.umaine.edu/francoamericain_forum/1090/thumbnail.jp
Value of syndromic surveillance within the Armed Forces for early warning during a dengue fever outbreak in French Guiana in 2006
<p>Abstract</p> <p>Background</p> <p>A dengue fever outbreak occured in French Guiana in 2006. The objectives were to study the value of a syndromic surveillance system set up within the armed forces, compared to the traditional clinical surveillance system during this outbreak, to highlight issues involved in comparing military and civilian surveillance systems and to discuss the interest of syndromic surveillance for public health response.</p> <p>Methods</p> <p>Military syndromic surveillance allows the surveillance of suspected dengue fever cases among the 3,000 armed forces personnel. Within the same population, clinical surveillance uses several definition criteria for dengue fever cases, depending on the epidemiological situation. Civilian laboratory surveillance allows the surveillance of biologically confirmed cases, within the 200,000 inhabitants.</p> <p>Results</p> <p>It was shown that syndromic surveillance detected the dengue fever outbreak several weeks before clinical surveillance, allowing quick and effective enhancement of vector control within the armed forces. Syndromic surveillance was also found to have detected the outbreak before civilian laboratory surveillance.</p> <p>Conclusion</p> <p>Military syndromic surveillance allowed an early warning for this outbreak to be issued, enabling a quicker public health response by the armed forces. Civilian surveillance system has since introduced syndromic surveillance as part of its surveillance strategy. This should enable quicker public health responses in the future.</p
Proposal of a framework for evaluating military surveillance systems for early detection of outbreaks on duty areas
<p>Abstract</p> <p>Background</p> <p>In recent years a wide variety of epidemiological surveillance systems have been developed to provide early identification of outbreaks of infectious disease. Each system has had its own strengths and weaknesses. In 2002 a Working Group of the Centers for Disease Control and Prevention (CDC) produced a framework for evaluation, which proved suitable for many public health surveillance systems. However this did not easily adapt to the military setting, where by necessity a variety of different parameters are assessed, different constraints placed on the systems, and different objectives required. This paper describes a proposed framework for evaluation of military syndromic surveillance systems designed to detect outbreaks of disease on operational deployments.</p> <p>Methods</p> <p>The new framework described in this paper was developed from the cumulative experience of British and French military syndromic surveillance systems. The methods included a general assessment framework (CDC), followed by more specific methods of conducting evaluation. These included Knowledge/Attitude/Practice surveys (KAP surveys), technical audits, ergonomic studies, simulations and multi-national exercises. A variety of military constraints required integration into the evaluation. Examples of these include the variability of geographical conditions in the field, deployment to areas without prior knowledge of naturally-occurring disease patterns, the differences in field sanitation between locations and over the length of deployment, the mobility of military forces, turnover of personnel, continuity of surveillance across different locations, integration with surveillance systems from other nations working alongside each other, compatibility with non-medical information systems, and security.</p> <p>Results</p> <p>A framework for evaluation has been developed that can be used for military surveillance systems in a staged manner consisting of initial, intermediate and final evaluations. For each stage of the process parameters for assessment have been defined and methods identified.</p> <p>Conclusion</p> <p>The combined experiences of French and British syndromic surveillance systems developed for use in deployed military forces has allowed the development of a specific evaluation framework. The tool is suitable for use by all nations who wish to evaluate syndromic surveillance in their own military forces. It could also be useful for civilian mobile systems or for national security surveillance systems.</p
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