One of the major research topics in unmanned aerial vehicle (UAV) collaborative control systems is the problem of multi-UAV target assignment and path planning (MUTAPP). It is a complicated optimization problem in which target assignment and path planning are solved separately. However, recalculation of the optimal results is too slow for real-time operations in dynamic environments because of the large number of calculations required. In this paper, we propose an artificial intelligence method named simultaneous target assignment and path planning (STAPP) based on a multi-agent deep deterministic policy gradient (MADDPG) algorithm, which is a type of multi-agent reinforcement learning algorithm. In STAPP, the MUTAPP problem is first constructed as a multi-agent system. Then, the MADDPG framework is used to train the system to solve target assignment and path planning simultaneously according to a corresponding reward structure. The proposed system can deal with dynamic environments effectively as its execution only requires the locations of the UAVs, targets, and threat areas. Real-time performance can be guaranteed as the neural network used in the system is simple. In addition, we develop a technique to improve the training effect and use experiments to demonstrate the effectiveness of our method.INDEX TERMS Multi-UAV, target assignment and path planning, multi-agent reinforcement learning, MADDPG, dynamic environments.
AimThe objective of the study reported here was to evaluate the therapeutic effects of hapten-enhanced chemoimmunotherapy in the treatment of advanced lung cancer by ultra-minimum incision personalized intratumoral chemoimmunotherapy (UMIPIC) and to analyze the effect of this immune booster.Materials and methodsA total of 97 patients with advanced lung cancer were treated with UMIPIC or intratumoral chemotherapy (ITCT). UMIPIC was delivered intratumorally in combination with a proprietary therapeutic regimen composed of three components – an oxidant, a cytotoxic drug, and hapten. ITCT applied using the same procedures and regimen, only without hapten. All data from the two groups were reviewed and analyzed. A total of 55 patients were treated with UMIPIC and 42 with ITCT. Patient responses were assessed with computed tomography scan 4–6 weeks after treatment, and all of the patients were followed until their deaths.ResultsMedian overall survival was 11.23 months in the UMIPIC (test) group and 5.62 months in the ITCT (control) group (P<0.01). The 6-month and 1-year survival rates of the UMIPIC and ITCT groups were 76.36% versus 45.23% (P<0.01) and 45.45% versus 23.81% (P<0.05), respectively. Two cycles of UMIPIC treatment (n=19) conferred a significant survival benefit compared with two cycles of ITCT (n=29); significant benefits in survival time were also found with UMIPIC (n=20) compared with ITCT (n=13) when both were utilized without adjuvant treatment.ConclusionThe hapten-enhanced clinical effect of UMIPIC conferred a superior survival time in patients with advanced lung cancer compared with ITCT. The addition of the hapten in UMIPIC demonstrates a significant advantage in terms of prolonged survival time.
This document develops an architecture and a set of requirements needed to support alerting of hosts that are in dormant mode. The architecture and requirements are designed to guide development of an IP protocol for alerting dormant IP mobile hosts, commonly called paging.
By solving the full equations of an extended two-fluid model in two dimensions, we give the first numerical study revealing non-equilibrium steady states in sheared entangled polymer mixtures. This research provides answers for some fundamental questions in sheared binary mixtures of entangled polymers. Our results reveal that non-equilibrium steady states with finite domain size do exist, and apparent scaling exponents L k ; _ g À1:05 and L ? ; _ g À1 are found over six decades of shear rate. Since the wall effects get involved in our simulations, the dependence of average domain size on system size cannot be strictly eliminated. In addition, as an obvious influence of viscoelasticity, the polymer viscosity h p appears to induce linear translation of the fitted lines. Through two-dimensional numerical simulations, we show the detailed dynamic evolution of microstructure in binary polymer mixtures with asymmetric composition under shear flow. It is found that the phase patterns are significantly different from symmetric fluids studied previously. Finally, we also identify the importance of wall effects and confirm the irreplaceable role of inertia for a non-equilibrium steady state.
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