Traditional approach for modelling the evolution of populations in the predatorprey ecosystem has commonly been undertaken using specific impulsive response function, and this kind of modelling is applicable only for a specific ecosystem under certain environmental situations only. This paper attempts to fill the gap

With the increasing demand for a personalized product and rapid market response, many companies expect to explore online user-generated content (UGC) for intelligent customer hearing and product redesign strategy. UGC has the advantages of being more unbiased than traditional interviews, yielding in-time response, and widely accessible with a sheer volume. From online resources, customers’ preferences toward various aspects of the product can be exploited by promising sentiment analysis methods. However, due to the complexity of language, state-of-the-art sentiment analysis methods are still not accurate for practice use in product redesign. To tackle this problem, we propose an integrated customer hearing and product redesign system, which combines the robust use of sentiment analysis for customer hearing and coordinated redesign mechanisms. Ontology and expert knowledges are involved to promote the accuracy. Specifically, a fuzzy product ontology that contains domain knowledges is first learned in a semi-supervised way. Then, UGC is exploited with a novel ontology-based fine-grained sentiment analysis approach. Extracted customer preference statistics are transformed into multilevels, for the automatic establishment of opportunity landscapes and house of quality table. Besides, customer preference statistics are interactively visualized, through which representative customer feedbacks are concurrently generated. Through a case study of smartphone, the effectiveness of the proposed system is validated, and applicable redesign strategies for a case product are provided. With this system, information including customer preferences, user experiences, using habits and conditions can be exploited together for reliable product redesign strategy elicitation.

The fault model of the inter‐turn short circuit of the dry air‐core reactor is first analysed in this study, by which an online monitoring method of the reactor inter‐turn insulation fault is proposed by using the change of the power angle. In order to achieve high‐precision measurement, the fundamental harmonic separation algorithm improved by Hanning windowed interpolation method can effectively reduce the error of power angle measurement caused by frequency fluctuation and harmonic interference. By comparing it with the power angle measurement errors of fast Fourier transform (FFT) and Hanning window interpolation FFT, the algorithm is verified. The sensitivity and stability of the equipment are verified by the experiment of simulating and eliminating the fault in the initial stage of the inter‐turn short circuit. At the same time, an online monitoring system for inter‐turn insulation fault of dry‐type air‐core reactor based on this method is designed, including field monitoring device, the intelligent electronic device of the dry air‐core reactor and expert software. The method and monitoring device proposed in this study enables the fault to be accurately monitored in the early stage, which is of great significance for the safe operation of the reactor.

Conventional piezoelectric actuators or robots have advantages of miniature sizes, fast responses, good accelerations, and long stroke, but they are difficult to recover their movement after a sudden rollover or overturn. In order to achieve a consecutive motion in an abrupt environment, a steerable miniature ambulatory robot (SMAR) with a caltrop-like structure is proposed based on piezoelectric actuation. A kinematic model of the SMAR is developed to design the structure of the robot and to analyze the working principle. A preliminary prototype is fabricated to verify the working principle that it has a capacity of 2D motion, with the maximum speed of 320 mm s −1 and the minimum turning radius of 40 mm when the drive voltage is 200 V (peakpeak value). In addition, a control strategy designed in a LabVIEW system which can refine the eigenvalues from complex motion trajectories, is presented for robust steering to a target in a short time, especially after a sudden rollover. Therefore, this SMAR can realize arbitrary and fast movements in a 2D task space, which is also appropriate for a dynamic environment, such as in a moving or rolling channel, and it can also step down with a smooth movement due to its special caltrop-like structure.

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Abstract-By using Matlab/Simulink as a development and simulation platform, a wind turbine simulation-testing system was designed with the data from GH Bladed software and IEC61400-1 standard. Moreover, a whole dynamic model of a MW-class variable speed constant frequency Doubly-Fed wind generator is presented, including wind regime, drive train and inverter generator system. Furthermore, with the simulationtesting, closed-loop test and comprehensive dynamic test of control system can be realized. In the end, the experimental results illustrate the validity and feasibility of the system and it will provide a new way for wind turbine simulation and testing.

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