2,864 research outputs found
UAV Swarm Mission Planning in Dynamic Environment Using Consensus-Based Bundle Algorithm.
To solve the real-time complex mission-planning problem for Multiple heterogeneous Unmanned Aerial Vehicles (UAVs) in the dynamic environments, this paper addresses a new approach by effectively adapting the Consensus-Based Bundle Algorithms (CBBA) under the constraints of task timing, limited UAV resources, diverse types of tasks, dynamic addition of tasks, and real-time requirements. We introduce the dynamic task generation mechanism, which satisfied the task timing constraints. The tasks that require the cooperation of multiple UAVs are simplified into multiple sub-tasks to perform by a single UAV independently. We also introduce the asynchronous task allocation mechanism. This mechanism reduces the computational complexity of the algorithm and the communication time between UAVs. The partial task redistribution mechanism has been adopted for achieving the dynamic task allocation. The real-time performance of the algorithm is assured on the premise of optimal results. The feasibility and real-time performance of the algorithm are validated by conducting dynamic simulation experiments
Conformal Quivers and Melting Molecules
Quiver quantum mechanics describes the low energy dynamics of a system of
wrapped D-branes. It captures several aspects of single and multicentered BPS
black hole geometries in four-dimensional supergravity such
as the presence of bound states and an exponential growth of microstates. The
Coulomb branch of an Abelian three node quiver is obtained by integrating out
the massive strings connecting the D-particles. It allows for a scaling regime
corresponding to a deep AdS throat on the gravity side. In this scaling
regime, the Coulomb branch is shown to be an invariant
multi-particle superconformal quantum mechanics. Finally, we integrate out the
strings at finite temperature---rather than in their ground state---and show
how the Coulomb branch `melts' into the Higgs branch at high enough
temperatures. For scaling solutions the melting occurs for arbitrarily small
temperatures, whereas bound states can be metastable and thus long lived.
Throughout the paper, we discuss how far the analogy between the quiver model
and the gravity picture, particularly within the AdS throat, can be taken.Comment: 49 pages, 16 figure
Interfacing low-energy SAW nebulization with liquid chromatography-mass spectrometry for the analysis of biological samples
Soft ionization methods for the introduction of labile biomolecules into a mass spectrometer are of fundamental importance to biomolecular analysis. Previously, electrospray ionization (ESI) and matrix assisted laser desorption-ionization (MALDI) have been the main ionization methods used. Surface acoustic wave nebulization (SAWN) is a new technique that has been demonstrated to deposit less energy into ions upon ion formation and transfer for detection than other methods for sample introduction into a mass spectrometer (MS). Here we report the optimization and use of SAWN as a nebulization technique for the introduction of samples from a low flow of liquid, and the interfacing of SAWN with liquid chromatographic separation (LC) for the analysis of a protein digest. This demonstrates that SAWN can be a viable, low-energy alternative to ESI for the LC-MS analysis of proteomic samples
Antibacterial activity of some selected medicinal plants of Pakistan
<p>Abstract</p> <p>Background</p> <p>Screening of the ethnobotenical plants is a pre-requisite to evaluate their therapeutic potential and it can lead to the isolation of new bioactive compounds.</p> <p>Methods</p> <p>The crude extracts and fractions of six medicinal important plants (<it>Arisaema flavum</it>, <it>Debregeasia salicifolia</it>, <it>Carissa opaca</it>, <it>Pistacia integerrima</it>, <it>Aesculus indica</it>, and <it>Toona ciliata</it>) were tested against three Gram positive and two Gram negative ATCC bacterial species using the agar well diffusion method.</p> <p>Results</p> <p>The crude extract of <it>P. integerrima </it>and <it>A. indica </it>were active against all tested bacterial strains (12-23 mm zone of inhibition). Other four plant's crude extracts (<it>Arisaema flavum</it>, <it>Debregeasia salicifolia</it>, <it>Carissa opaca</it>, and <it>Toona ciliata</it>) were active against different bacterial strains. The crude extracts showed varying level of bactericidal activity. The aqueous fractions of <it>A. indica </it>and <it>P. integerrima </it>crude extract showed maximum activity (19.66 and 16 mm, respectively) against <it>B. subtilis</it>, while the chloroform fractions of <it>T. ciliata </it>and <it>D. salicifolia </it>presented good antibacterial activities (13-17 mm zone of inhibition) against all the bacterial cultures tested.</p> <p>Conclusion</p> <p>The methanol fraction of <it>Pistacia integerrima</it>, chloroform fractions of <it>Debregeasia salicifolia </it>&<it>Toona ciliata </it>and aqueous fraction of <it>Aesculus indica </it>are suitable candidates for the development of novel antibacterial compounds.</p
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