Study on Agent-based Innovation Behavior Research Technique

AbstractThe agent-based computer simulation method is available for complex system studying. The innovation system has characters of emergence and evolution; it is also a complex system. In order to build agent-based computer simulation model for innovation behavior studying, processes of question analysis, property abstract, model environment constructing, model agent building, model parameter adjustment, model running and result analysis have to be processed

Improved GWO Algorithm for UAV Path Planning on Crop Pest Monitoring

Agricultural information monitoring is the monitoring of the agricultural production process, and its task is to monitor the growth process of major crops systematically. When assessing the pest situation of crops in this process, the traditional satellite monitoring method has the defects of poor real-time and high operating cost, whereas the pest monitoring through Unmanned Aerial Vehicles (UAVs) effectively solves the above problems, so this method is widely used. An important key issue involved in monitoring technology is path planning. In this paper, we proposed an Improved Grey Wolf Optimization algorithm, IGWO, to realize the flight path planning of UAV in crop pest monitoring. A map environment model is simulated, and information traversal is performed, then the search of feasible paths for UAV flight is carried out by the Grey Wolf Optimization algorithm (GWO). However, the algorithm search process has the defect of falling into local optimum which leading to path planning failure. To avoid such a situation, we introduced the probabilistic leap mechanism of the Simulated Annealing algorithm (SA). Besides, the convergence factor is modified with an exponential decay mode for improving the convergence rate of the algorithm. Compared with the GWO algorithm, IGWO has the 8.3%, 16.7%, 28.6% and 39.6% lower total cost of path distance on map models with precision of 15, 20, 25 and 30 respectively, and also has better path planning results in contrast to other swarm intelligence algorithms

Rapid Solidification of Undercooled Melts

Rapid solidification and microstructure evolution of deeply undercooled bulk concentrated Ni-20%at.Cu and Co-20%at.Pd alloys are strictly and systematically evaluated. First, thermodynamics of the undercooled melt is discussed. Consideration is provided for not only the systematic microstructure evolution within a broad undercooling range, but also the dendrite growth mechanism and the rapid solidification characteristics. The dendrite growth in the bulk undercooled melts was captured by a high speed camera. The first kind of grain refinement occurring in the low undercooling regimes was explained by a current grain refinement model. Besides for the dendrite melting mechanism, the stress originating from the solidification contraction and thermal strain in the first mushy zone during rapid solidification could be a main mechanism causing the second kind of grain refinement above the critical undercooling. This internal-stress led to the distortion and breakup of the primary dendrites and was semi-quantitatively described by a corrected stress accumulation model. It was found that the stress induced recrystallization could make the primary microstructures refine substantially after recalescence

An Experimental and Analytical Study of a Radiative Cooling System with Flat Plate Collectors

AbstractA nocturnal radiative cooling system with flat plate solar collectors in Beijing, is assessed both experimentally and numerically. A cooling loop, including a radiator, a storage tank, pump, radiant floor and connecting pipes has been studied experimentally. The heat loss of an uncovered night-sky radiator was analysed according to radiation and convection theory. The water is circulated through the flat-plate radiator having 2 m2 of collector area at night to be cooled by convection and radiation to sky. The results indicate that the minimum temperature of the floor surface is 19.5°C. Vertical temperature field is uniform. Design temperature can increase 1°C compared with conventional heat convection. The average net cooling reached 26W/m2, as condensation does not occur. It is possible to increase the total cooling capacity while maintaining a low pressure drop. It demonstrates the feasibility of cooling using fluid medium through nocturnal radiation