Abstract-Differential evolution (DE) and particle swarm optimization (PSO) are two formidable population-based optimizers (POs) that follow different philosophies and paradigms, which are successfully and widely applied in scientific and engineering research. The hybridization between DE and PSO represents a promising way to create more powerful optimizers, especially for specific problem solving. In the past decade, numerous hybrids of DE and PSO have emerged with diverse design ideas from many researchers. This paper attempts to comprehensively review the existing hybrids based on DE and PSO with the goal of collection of different ideas to build a systematic taxonomy of hybridization strategies. Taking into account five hybridization factors, i.e., the relationship between parent optimizers, hybridization level, operating order (OO), type of information transfer (TIT), and type of transferred information (TTI), we propose several classification mechanisms and a versatile taxonomy to differentiate and analyze various hybridization strategies. A large number of hybrids, which include the hybrids of DE and PSO and several other representative hybrids, are categorized according to the taxonomy. The taxonomy can be utilized not only as a tool to identify different hybridization strategies, but also as a reference to design hybrid optimizers. The tradeoff between exploration and exploitation regarding hybridization design is discussed and highlighted. Based on the taxonomy proposed, this paper also indicates several promising lines of research that are worthy of devotion in future.

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To enhance the fault transient performance of aerospace multiphase permanent magnet synchronous motor (PMSM) system, an adaptive robust speed control is proposed regardless of the phase open-circuit (OC) and short-circuit (SC) fault in this paper, which can be applied for both the redundant motor system and fault tolerant motor system. For aerospace multiphase PMSM system, besides external load disturbance and system parameter perturbation, there inevitably exists the electromagnetic torque ripple in fault transient process, which can degrade the system performance and even cause the system instability. To cope with this issue, the electromagnet torque ripple of the multiphase PMSM system in fault transient process is first analyzed. Then, by considering the electromagnet torque fluctuation caused by fault transient as a system uncertainty, a novel adaptive robust speed control scheme is proposed, while the adaptive law is constructed to emulate the total system uncertainty bound, which include the load disturbance, the parameter variation, and the electromagnetic torque fluctuation due to fault transient. The resulting control can ensure the speed control performance even in fault transient process regardless of the uncertainty, in which no prior estimation of the uncertainty bound is required. In addition, the proposed adaptive robust speed control is demonstrated by a six-phase PMSM experimental platform. The novelty of this research is to explore a novel adaptive robust speed control to strengthen the fault tolerance performance of multiphase PMSM system even in fault transient process, which requires no prior estimation of the uncertainty bound. Index Terms-Multiphase permanent magnet motor, fault transient, fault tolerance, adaptive robust control. I. INTRODUCTIONITH the superiority of high fuel efficiency, good maintainability and low environmental noise, the more

The new in situ seed baiting method using seed packets to assess germination of orchid species within soil provides a means of locating, collecting, and identifying specific fungi that are involved in the lifecycle of orchids in the wild and investigating their relationship with the orchids under natural field conditions. Two isolates (SHH44, SHH53) originating from the seedlings found in the seeds packets in situ were demonstrated to support seed germination and seedling development (in vitro) of two endangered Chinese endemic herbs, Dendrobium officinale and Dendrobium nobile (Orchidaceae). Advanced protocorm development (Stage 3 and greater) in this study of these species of Dendrobium only occurred under the 12/12 h L/D photo-period indicated that illumination may play an important role in seedling recruitment of terrestrial orchid species in their natural environment. The information provided in this study may prove invaluable in the conservation of D. officinale and D. nobile and congener species in China, especially given their rare status.

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