No abstract

In recent years, the unmanned aerial vehicles (UAVs) have exhibited significant market potential to greatly reduce the cost and time in the field of logistics. The use of UAVs to provide commercial courier has become an emerging industry, remarkably shifting the energy use of the freight sector. However, due to limited battery capacities, the flight duration of civilian rotorcraft UAVs is still short, hindering them from performing remote jobs. In this case, people customarily utilize ground vehicles to carry and assist UAVs in various applications, including cargo delivery. Most previous studies on vehicle-drone cooperative parcel delivery considered only one UAV, thereby suffering from low efficiency when serving a large number of customers. In this paper, we propose a novel hybrid genetic algorithm, which supports the cooperation of a ground vehicle and multiple UAVs for efficient parcel delivery. Our routing and scheduling algorithm allows multiple UAVs carried by the vehicle to simultaneously deliver multiple parcels to customers residing in different locations. The proposed algorithm consists of a pipeline of several modules: population management, heuristic population initialization, and population education. The performance evaluation results show that the proposed algorithm has significant efficiency over existing algorithms.INDEX TERMS Unmanned aerial vehicle, cargo delivery, routing, scheduling.

No abstract

A novel side-pumped structure with microlens-free diode arrays and a lensduct was demonstrated. This structure is much more robust and simple than traditional approach of a microlens-conditioned diode arrays with a lensduct. A quasi-CW diode arrays side-pumped KD*P Q-switched Yb:YAG slab laser has been demonstrated. An output energy of ∼10 mJ/pulse with pulse width as short as ∼20ns is obtained at 1-10 Hz repetition rate. To our knowledge, this is the shortest pulse width of Electro-optic Q-switched laser output by using Yb:YAG as the gain medium. Output energy as a function of Yb:YAG absorbed energy

A green laser with output power 15 W at 515 nm is introduced, which was based on an extra‐cavity frequency doubling of a corner‐pumping Yb:YAG slab laser, with pulse repetition rate of 10 kHz and pulse duration of ∼150 ns, using an acousto‐optic Q‐switcher. An LBO crystal was used as nonlinear crystal for frequency doubling in this experiment, which was cut for type‐I non‐critical phase‐matching. The frequency doubling efficiency was 30%. (© 2007 by Astro, Ltd. Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)