Silk fibroin-type II collagen scaffold was made by 3D printing technique and freeze-drying method, and its mechanical properties were studied by experiments and theoretical prediction. The results show that the three-...
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Hybridization is termed as an efficient strategy to improve the performance of many optimizers, and the design of efficient hybrids for difficult optimization problems remains a challenging field. In this study, an au...
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Hybridization is termed as an efficient strategy to improve the performance of many optimizers, and the design of efficient hybrids for difficult optimization problems remains a challenging field. In this study, an automatic method is proposed to generate various hybrid optimizers based on particle swarm optimization and differential evolution for a given problem. Based on the unified framework for hybridization proposed in our recent work, the proposed method can provide plenty of hybrid optimizers for a specific problem with given parent optimizers. Besides, an approach which can provide the unified representation of different kinds of hybridization levels is developed. Moreover, all the generated hybrids are evaluated on the CEC2017 benchmark problems, and the results of the statistic analysis and the Wilcoxon's rank-sum tests demonstrate that the hybrid optimizer utilizing the hybridization strategy performs obviously better than the others on the test functions.
In the blast furnace ironmaking process, the running state of the blast furnace can be directly adjusted by the burden operation. Therefore, the explicit relation between the burden operation and the running state var...
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The growing penetration of the distributed generation (DG) makes the traditional passive distribution network change to active distribution network. A new fault location method is proposed in this paper based on the c...
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With the construction of global energy interconnection, plenty of fluctuating renewable energy access the distribution network, power system dynamic behavior is more complex. The wide-area measurement system light (WA...
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Small reservoirs play an important role in the safety of flood control and economic development. Their operation and management are characterized by a large number of objects and a large amount of information, which r...
Small reservoirs play an important role in the safety of flood control and economic development. Their operation and management are characterized by a large number of objects and a large amount of information, which requires effective data analysis means support. Based on this, big data analysis technology has been gradually applied and popularized in the operation and management of small reservoirs. In this paper, we first set up a small reservoir flood reporting system based on the data collection and analysis of various aspects such as reservoir capacity, characteristic water level, real-time data of water and rain situation, meteorological data, and presented the results in the paper. Secondly, we analyzed the under-reporting situation during the flood control period of the reservoir, and explored the under-reporting factors and the time when the under-reporting occurred. Finally, we conduct a time series analysis on the situation of water level exceeding the limit of 50 reservoirs during the flood control period, so that we can find the key reservoirs and important time points of flood control more intuitively and provide reference for the smooth development of the management of small reservoirs.
In this paper, the problem of mean square exponential stabilization for sampled-data Markovin jump systems is studied. A time-scheduled Lyapunov functional consisting of a exponential-type looped function is construct...
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In this paper, the problem of mean square exponential stabilization for sampled-data Markovin jump systems is studied. A time-scheduled Lyapunov functional consisting of a exponential-type looped function is constructed using segmentation technology and linear interpolation. Based on this new Lyapunov functional, a less conservative mean square exponential stability criterion is obtained such that a bigger maximum decay rate can be easily calculated. Meanwhile, the quantitative relationship among some system parameters, maximum sampling period, and decay rate is established. Moreover, a time-dependent state feedback sample-data controller is designed. Significant improvements of the proposed exponential-type time-scheduled Lyapunov functional method over some existing ones are verified by numerical examples.
Hydraulic axial piston motor is one of the fundamental components in hydraulic systems;it is widely used in engineered machine, especially in high-power drive or reciprocating motion, such as hydraulic excavator. For ...
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The distributed generation which is integrated in the active distribution network changes power flow, bringing new challenges to the voltage control. When voltage limit violation happens, in order to make the voltage ...
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The distributed generation which is integrated in the active distribution network changes power flow, bringing new challenges to the voltage control. When voltage limit violation happens, in order to make the voltage return to normal range and improve the voltage quality, a novel voltage control strategy is proposed. Considering the voltage quality and node importance, the electrical closeness centrality and key node contribution degree are defined, and the key nodes are determined by the orders of the key node contribution degree. This paper uses the reactive power compensation devices which are installed at the key nodes coordinated with the reactive power output of the distributed generation to realize the voltage optimization control. The voltage optimization control model is established by taking the minimum power loss as an objective function. Using the particle swarm optimization algorithm solves the model. The simulation results of the improved IEEE-33 bus system verify the effectiveness of the proposed method.
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