This paper describes an algorithm that has been used for the autonomous control of multiple UAVs tasked with the high level objective of locating a radar subject to a number of real world ...constraints. The distributed, fully autonomous, cooperative control of the multiple UAV system was executed using sensor input from a heterogenous network of miniaturised Electronic Surveillance (ES) payloads. An ES sensor onboard one UAV detected a radar target and cross-cued ES receivers onboard two other UAVs. Based on the information shared between these UAVs the target radar was approximately located by each UAV Once the UAVs had coarsely located the target they autonomously, dynamically, and continuously adapted their flight trajectories to progressively improve the accuracy with which they were able to co-operatively locate the radar target. The UAVs were able to accurately locate the radar while simultaneously avoiding no-fly zones, one another and remaining within communication range.
The Brooklyn Traffic Real-Time Ambient Pollutant Penetration and Environmental Dispersion (B-TRAPPED) field study examined indoor and outdoor exposure to traffic-generated air pollution by studying ...the individual processes of generation of traffic emissions, transport and dispersion of air contaminants along a roadway, and infiltration of the contaminants into a residence. Real-time instrumentation was used to obtain highly resolved time-series concentration profiles for a number of air pollutants. The B-TRAPPED field study was conducted in the residential Sunset Park neighborhood of Brooklyn, NY, USA, in May 2005. The neighborhood contained the Gowanus Expressway (Interstate 278), a major arterial road (4(th) Avenue), and residential side streets running perpendicular to the Gowanus Expressway and 4(th) Avenue. Synchronized measurements were obtained inside a test house, just outside the test house façade, and along the urban residential street canyon on which the house was located. A trailer containing Federal Reference Method (FRM) and real-time monitors was located next to the Gowanus Expressway to assess the source. Ultrafine particulate matter (PM), PM(2.5), nitrogen oxides (NO(x)), sulfur dioxide (SO(2)), carbon monoxide (CO), carbon dioxide (CO(2)), temperature, relative humidity, and wind speed and direction were monitored. Different sampling schemes were devised to focus on dispersion along the street canyon or infiltration into the test house. Results were obtained for ultrafine PM, PM(2.5), criteria gases, and wind conditions from sampling schemes focused on street canyon dispersion and infiltration. For comparison, the ultrafine PM and PM(2.5) results were compared with an existing data set from the Los Angeles area, and the criteria gas data were compared with measurements from a Vancouver epidemiologic study. Measured ultrafine PM and PM(2.5) concentration levels along the residential urban street canyon and at the test house façade in Sunset Park were demonstrated to be comparable to traffic levels at an arterial road and slightly higher than those in a residential area of Los Angeles. Indoor ultrafine PM levels were roughly 3-10 times lower than outdoor levels, depending on the monitor location. CO, NO(2), and SO(2) levels were shown to be similar to values that produced increased risk of chronic obstructive pulmonary disease hospitalizations in the Vancouver studies.
Titanium circumferential grommets have been developed for finger joint arthroplasty that fit on the base of the silicone implant stems to protect the flexible hinge from tearing and fracture. To ...facilitate grommet insertion, new intramedullary bone rasps have been devised with a reverse cutting tooth pattern, an extended shaft for an improved view of the surgical field, and a redesigned cutting head to allow for grommet insertion. Surgical accessibility and ease of recognition have been facilitated by the development of color-coded sizers. All of the instruments necessary for finger joint surgery are available in a molded tray that has also been redesigned with a transparent lid and clearly labeled compartments for accurate determination of instruments and implant sizers.
Reviews of Books Cartledge, Paul S.; Ogden, Daniel; Eckstein, Arthur M. ...
International history review,
12/2003, Volume:
25, Issue:
4
Journal Article
We present the results of the first spectroscopic follow-up of 132 optically blue UV-excess sources selected from the UV-excess survey of the Northern Galactic Plane (UVEX). The UV-excess spectra are ...classified into different populations and grids of model spectra are fit to determine spectral types, temperatures, surface gravities and reddening. From this initial spectroscopic follow-up 95% of the UV-excess candidates turn out to be genuine UV-excess sources such as white dwarfs, white dwarf binaries, subdwarfs type O and B, emission line stars and QSOs. The remaining sources are classified as slightly reddened main-sequence stars with spectral types later than A0V. The fraction of DA white dwarfs is 47% with reddening smaller than E(B-V)<0.7 mag. Relations between the different populations and their UVEX photometry, Galac- tic latitude and reddening are shown. A larger fraction of UVEX white dwarfs is found at magnitudes fainter than g>17 and Galactic latitude smaller than |b|<4 compared to main-sequence stars, blue horizontal branch stars and subdwarfs.
We report on the discovery of over 50 strong Halpha emitting objects towards the large OB association Cyg OB2 and the HII region DR 15 on its southern periphery. This was achieved using the INT ...Photometric Halpha Survey of the Northern Galactic Plane (IPHAS), combined with follow-up spectroscopy using the MMT multi-object spectrometer HectoSpec. We present optical spectra, supplemented with optical r', i' and Halpha photometry from IPHAS, and near-infrared J, H, and K photometry from 2MASS. The position of the objects in the (J - H) versus (H - K) diagram strongly suggests most of them are young. Many show CaII IR triplet emission indicating that they are in a pre-main sequence phase of evolution of T Tauri and Herbig Ae nature. Among these, we have uncovered pronounced clustering of T Tauri stars roughly a degree south of the centre of Cyg OB2, in an arc close to the HII region DR 15, and the radio ring nebula G79.29+0.46, for which we discuss its candidacy as a luminous blue variable (LBV). The emission line objects toward Cyg OB2 itself could be the brightest most prominent component of a population of lower mass pre-main sequence stars that has yet to be uncovered. Finally, we discuss the nature of the ongoing star formation in Cyg OB2 and the possibility that the central OB stars have triggered star formation in the periphery.
Frequency measurements for the Delta V = 2 transitions of CO in the integrated light spectrum of the sun are presented. The nature and magnitude of systematic errors which typically arise in absolute ...velocity measurements of integrated sunlight are explored in some detail, and measurements believed accurate at the level of about 5 m/s or less are presented. It is found that the integrated light velocity varies by about 3 m/s or less over a one-day period. Over the long term, the data indicate an increasing blue-shift in these weak infrared lines amounting to 30 m/s from 1983 to 1985. The sense of the drift is consistent with a lessening in the magnetic inhibition of granular convection at solar minimum. Such an effect has implications for the spectroscopic detectability of planetary-mass companions to solar-type stars.
Knowbot Programming: system support for mobile agents Hylton, J.; Manheimer, K.; Drake, F.L. ...
Proceedings - International Workshop on Object Orientation in Operating Systems,
1996
Conference Proceeding, Journal Article
Knowbot Programs are mobile agents intended for use in widely distributed systems like the Internet. We describe our experiences implementing security, process migration, and inter-process ...communication in a prototype system implemented using the object-oriented programming language Python. This infrastructure supports applications that are composed of multiple, autonomous agents that can migrate to use network resources more efficiently.
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