No abstract

SUMMARYInsect wings demonstrate elaborate three-dimensional deformations and kinematics. These deformations are key to understanding many aspects of insect flight including aerodynamics, structural dynamics and control. In this paper, we propose a template-based subdivision surface reconstruction method that is capable of reconstructing the wing deformations and kinematics of free-flying insects based on the output of a high-speed camera system. The reconstruction method makes no rigid wing assumptions and allows for an arbitrary arrangement of marker points on the interior and edges of each wing. The resulting wing surfaces are projected back into image space and compared with expert segmentations to validate reconstruction accuracy. A least squares plane is then proposed as a universal reference to aid in making repeatable measurements of the reconstructed wing deformations. Using an Eastern pondhawk (Erythimus simplicicollis) dragonfly for demonstration, we quantify and visualize the wing twist and camber in both the chord-wise and span-wise directions, and discuss the implications of the results. In particular, a detailed analysis of the subtle deformation in the dragonflyʼs right hindwing suggests that the muscles near the wing root could be used to induce chord-wise camber in the portion of the wing nearest the specimenʼs body. We conclude by proposing a novel technique for modeling wing corrugation in the reconstructed flapping wings. In this method, displacement mapping is used to combine wing surface details measured from static wings with the reconstructed flapping wings, while not requiring any additional information be tracked in the high speed camera output. Supplementary material available online at

Free forward flight of cicadas is investigated through high-speed photogrammetry, three-dimensional surface reconstruction and computational fluid dynamics simulations. We report two new vortices generated by the cicada's wide body. One is the thorax-generated vortex, which helps the downwash flow, indicating a new phenomenon of lift enhancement. Another is the cicada posterior body vortex, which entangles with the vortex ring composed of wing tip, trailing edge and wing root vortices. Some other vortex features include: independently developed left-and right-hand side leading edge vortex (LEV), dual-core LEV structure at the mid-wing region and nearwake two-vortex-ring structure. In the cicada forward flight, approximately 79% of the total lift is generated during the downstroke. Cicada wings experience drag in the downstroke, and generate thrust during the upstroke. Energetics study shows that the cicada in free forward flight consumes much more power in the downstroke than in the upstroke, to provide enough lift to support the weight and to overcome drag to move forward.

This paper presents new explorations into the use of agent technology applied to the protection coordination of power systems. The impact of distributed generators on protection coordination is first discussed. Then, a coordination multiagent system is proposed with the functions of the agents described. In the proposed system, communication will play an important role to provide more information for the relay coordination besides the relay settings. Communication simulation has been carried out on the Java Agent Development Framework platform. The information communication process shows that adaptive coordination can be achieved.

No abstract

No abstract

Typical particleboard wood-adhesive urea-formaldehyde (UF) resins, synthesized with formaldehyde/first urea (F/U 1 ) mol ratios of 1.80, 2.10, and 2.40 and the second urea added to an overall F/U ratio of 1.15, in weak alkaline pH, were allowed to stand at room temperature over a period of 50 days.13 C-NMR of time samples taken over the storage period showed gradual migration of hydroxymethyl groups from the polymeric first-urea components to the monomeric second-urea components and also an advancing degree of polymerization of resins by forming methylene and methylene ether groups involving the second urea. These phenomena that varied with the F/U 1 mol ratios used in the resin syntheses due to the varying polymer branching structures resulted in the first step of resin synthesis. Varying viscosity decreases and increases of the resins also occurred. Due to these chemical and physical changes, the particleboards that bonded with the sampled resins showed varying bond strength and formaldehydeemission values, indicating process optimizations possible to improve bonding and formaldehyde-emission performances.

Atmospheric Pressure Plasma Jet (APPJ) arrays are considered as one of the most promising methods for uniform plasma processing of large uneven surfaces. To improve the downstream uniformity and enhance the surface treatment effects, it is important to reveal the mechanisms of the jet‐to‐jet interactions of plasma plumes in the jet array. In this paper, the electrical, optical, and fluid characteristics of the He and Ar three‐channel one‐dimensional (1D) plasma jet arrays with cross‐field needle‐ring electrode structure are studied and compared. It is found that there are divergences in the outside plumes of the propagation trajectory by the repellency of the plasma bullets and the spatial uniformity of the He and Ar plasma jet arrays can be improved with a lower applied voltage and a higher gas flow rate. The deflection angle of side plumes with respect to the central one of He is larger than that of Ar jet array due to the lighter molecular weight and better discharge synchronization. The experimental results show that Ar jet array is more controllable and stable and is more suitable for the design of the practical, simpler, and cheaper scalable plasma jet arrays.