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331.
    
In recent years, various heuristic optimization methods have been developed. Many of these methods are inspired by swarm behaviors in nature. In this paper, a new optimization algorithm namely Gravitational Search Algorithm (GSA) based on the law of gravity and mass interactions is illustrated for designing Static Synchronous Series Compensator (SSSC) for single and multimachine power systems. In the proposed algorithm, the searcher agents are a collection of masses which interact with each other based on the Newtonian gravity and the laws of motion. The proposed method has been compared with some well-known heuristic search methods. The obtained results confirm the high performance of the proposed method in tuning SSSC compared with Bacteria Foraging (BF) and Genetic Algorithm (GA). Moreover, the results are presented to demonstrate the effectiveness of the proposed controller to improve the power systems stability over a wide range of loading conditions.  相似文献   
332.
    
Comparing with the traditional distribution network, a significant feature of the active distribution network (ADN) is that the performance of distributed generation (DG) units, energy storage units and micro-grid (MG) in the network is controllable for the distribution network operator. Considering the characteristics of the distributed power supply and micro-grid, and giving full play to the advantages of distributed generation technology in the economic, environmental and energy aspects, this paper highlights an environmental protection and energy saving optimal schedule model for ADN. The scheduling model focuses on the minimum network loss, minimum voltage deviation and minimum difference between peak and valley load. In addition, the two stage algorithm is presented to solve the proposed multi-objective scheduling model of ADN. First, a set of Pareto solutions are obtained by using the proposed particle swarm optimization combined with bacterial foraging algorithm (PSO-BFO) to solve multi-objective optimization problems, then the optimal schedule strategy of ADN is gained through evaluating the Pareto solutions with entropy weight decision-making method. To avoid the search falling into local optimal solution, the two-value crossover operator is introduced to exchange the information among subpopulations and update the position of related particles. Meanwhile, the adaptive adjusting inertia constant strategy is used to improve the algorithm convergence speed. Finally, the case study results demonstrate the rationality of the proposed optimal schedule model and the validity of its solution algorithm for ADN.  相似文献   
333.
群智能是由自然或人造的分散自组织系统所表现出来的集体智能.群智能包含一组简单的个体,其中个体与个体、个体与环境之间存在局部交互行为.虽然个体遵循非常简单的规则,但是微观的交互最终还是导致了宏观的智能行为.在本文中,我们对典型群智能方法的起源、发展、理论、技术、应用等做了深入的研究,包括了蚁群优化、粒子群优化、人工蜂群、细菌觅食优化、萤火虫共五类算法.文末提出群智能发展的六个方向.  相似文献   
334.
Human memory appears to be adaptively “biased” towards remembering the locations of (fitness-relevant) high-calorie nutritional resources. It remains to be investigated whether this high-calorie bias in human spatial memory influences how individuals navigate the modern food environment, and whether it is proximally associated with attentional processes. 60 individuals completed computer-based food eye-tracking and spatial memory tasks in a lab setting, as well as a food search and covert food choice task in an unfamiliar supermarket. The high-calorie spatial memory bias was replicated, as individuals more accurately recalled locations of high-calorie relative to low-calorie foods, regardless of hedonic evaluations or familiarity with foods. Although individuals were faster at (re)locating high-calorie (versus low-calorie) items in the supermarket, the bias did not predict a lower search time for high-calorie foods, or a higher proportion of high-calorie food choice. Rather, an enhanced memory for high-calorie food locations was associated with a lower perceived difficulty (i.e. greater ease) of finding high-calorie items in the supermarket, which may potentiate later choice of a high-calorie food. The high-calorie spatial memory bias was also found to be expressed independently of the amount of visual attention individuals allocated to high-calorie versus low-calorie foods. Findings further substantiate the notion that human spatial memory shows sensitivity to the caloric content of a potential resource and automatically prioritizes those with greater energy payoffs. Such a spatial mechanism that was adaptive for energy-efficient foraging within fluctuating ancestral food environments could presently yield maladaptive “obesogenic” consequences, through altering perceptions of food search convenience.  相似文献   
335.
发展分布式能源系统对于实现的“碳达峰”和“碳中和”,提升可再生能源的开发利用具有重要意义。提出一种基于细菌觅食优化算法(BFOA)的配电网分布式电源(DG)选址定容方法。建立以配电网的功率损耗指数、电压偏差以及安装分布式电源所降低的净运行成本最小为目标的数学模型及约束条件,提出损耗敏感系数(LSF)来确定DG安装位置,并引用BFOA算法求解DG的最佳容量。仿真表明,相对于传统优化算法,BFOA算法在模型求解时间和收敛速度上具有明显优势,所提规划方法能够最大限度地降低功率损耗和运行成本,并提高系统的电压稳定性。  相似文献   
336.
    
Non-orthogonal multiple access (NOMA) is a strong contender multicarrier waveform technique for the fifth generation (5G) communication system. The high peak-to-average power ratio (PAPR) is a serious concern in designing the NOMA waveform. However, the arrangement of NOMA is different from the orthogonal frequency division multiplexing. Thus, traditional reduction methods cannot be applied to NOMA. A partial transmission sequence (PTS) is commonly utilized to minimize the PAPR of the transmitting NOMA symbol. The choice phase aspect in the PTS is the only non-linear optimization obstacle that creates a huge computational complication due to the respective non-carrying sub-blocks in the unitary NOMA symbol. In this study, an efficient phase factor is proposed by presenting a novel bacterial foraging optimization algorithm (BFOA) for PTS (BFOA-PTS). The PAPR minimization is accomplished in a two-stage process. In the initial stage, PTS is applied to the NOMA signal, resulting in the partition of the NOMA signal into an act of sub-blocks. In the second stage, the best phase factor is generated using BFOA. The performance of the proposed BFOA-PTS is thoroughly investigated and compared to the traditional PTS. The simulation outcomes reveal that the BFOA-PTS efficiently optimizes the PAPR performance with inconsequential complexity. The proposed method can significantly offer a gain of 4.1 dB and low complexity compared with the traditional OFDM.  相似文献   
337.
牛培峰  彭鹏 《计量学报》2020,41(7):879-885
提出了一种改进的最优觅食算法(POFA),在最优觅食算法中引入自适应惯性权值与全局最优解来改进算法的更新公式,同时加入相空间搜索的机制。利用改进的最优觅食算法优化极端学习机(ELM)构建一个改进的极端学习机模型(POFA-ELM),并用该模型对锅炉NOx的排放特性进行建模。将该模型与ELM、差分进化算法、粒子群算法、人工蜂群算法以及基本的最优觅食算法优化的ELM模型进行比较。结果表明:该模型的预测精度更好,泛化能力更强,可以更加准确地预测NOx的排放质量浓度。  相似文献   
338.
Brown treesnakes (Boiga irregularis) responded with more tongue flicks to blood (from rabbits, rats, and mice) than to water. When rat blood was centrifuged at 3500 rpm for 5 min, separating serum from cellular residue, snakes responded strongly to serum but not to cellular residue.  相似文献   
339.
2-Acylcyclohexane-1,3-diones produced in the mandibular glands ofEphestia kuehniella Zeller (Lepidoptera: Pyralidae) fifth instars acted as arrestment and host-trail following kairomones for the parasitoid,Bracon hebetor (Say) (Hymenoptera: Braconidae). The behavioral response of the parasitoids to the kairomone varied with kairomone concentration and distribution. However, only small differences in activity were noted for the different mandibular gland components.B. hebetor females that encountered filter paper patches impregnated with the kairomone exhibited antennation and probing behavior. Females followed trails formed with 2-[(Z,E)12,14-hexadecadienoyl]cyclohexane-1,3-dione in the same manner exhibited with host-made trails. At concentrations of 1.0 g/mm and above, trail following was interrupted by frequent probing.  相似文献   
340.
In 2 experiments, dwarf hamsters (Phodopus campbelli) were trained to find palatable foods in an open field. The location of each food patch remained the same throughout each experiment, and only 1 food was available per day. Once subjects had been trained to find each food in its unique location, they progressed to a testing phase in which subjects’ mates were allowed to eat and hoard the food that was available in the open field each day. The foods that subjects’ mates brought back to the home cages then served as discriminative stimuli signaling which food could be obtained in the open field. Subjects generally approached the patch containing the food hoarded by their mates, suggesting that dwarf hamster burrows could function as information centers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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