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PWM高速开关阀的研制与应用 总被引:3,自引:0,他引:3
介绍了新型PWM高速开关阀的结构、工作原理及其具体的应用。经过试验表明.该新型PWM高速开关阀的开关频率达到14Hz,可以满足电液控制系统需求。 相似文献
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Chyung (1984) has presented a method for exactly reconstructing the inaccessible variables of a linear time-invariant control system. Roppenecker (1985) pointed out that this method is only applicable to a special case. In the present paper, the validity of Chyung's method for general linear time-invariant control systems is proved, and for the convenience of digital implementation, a scheme for the choosing of time delays hi is proposed. Finally, a method is presented for reconstructing the inaccessible variables in a reduced-order form. 相似文献
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LIU Shuang MENG Jiayuan ZHAO Xin YANG Jiaji HE Feng QI Hongzhi ZHOU Peng HU Yong MING Dong 《国外电子测量技术》2014,1(3):17-24
Electroencephalographic (EEG)-based emotion recognition has received increasing attention in the field of human-computer interaction (HCI) recently, there however remains a number of challenges in building a generalized emotion recognition model, one of which includes the difficulty of an EEG-based emotion classifier trained on a specific task to handle other tasks. Little attention has been paid to this issue. The current study is to determine the feasibility of coping with this challenge using feature selection. 12 healthy volunteers were emotionally elicited when conducting picture induced and video induced tasks. Firstly, support vector machine (SVM) classifier was examined under within-task conditions (trained and tested on the same task) and cross-task conditions (trained on one task and tested on another task) for picture induced and video induced tasks. The within-task classification performed fairly well (classification accuracy: 51.6% for picture task and 94.4% for video task). Cross-task classification, however, deteriorated to low levels (around 44%). Trained and tested with the most robust feature subset selected by SVM-recursive feature elimination (RFE), the performance of cross-task classifier was significantly improved to above 68%. These results suggest that cross-task emotion recognition is feasible with proper methods and bring EEG-based emotion recognition models closer to being able to discriminate emotion states for any tasks. 相似文献
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Yang MING 《控制理论与应用(英文版)》2018,16(3):212-220
In this paper, variational inference is studied on manifolds with certain metrics. To solve the problem, the analysis is first proposed for the variational Bayesian on Lie group, and then extended to the manifold that is approximated by Lie groups. Then the convergence of the proposed algorithm with respect to the manifold metric is proved in two iterative processes: variational Bayesian expectation (VB-E) step and variational Bayesian maximum (VB-M) step. Moreover, the effective of different metrics for Bayesian analysis is discussed. 相似文献
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Session-based recommendation (SBR) and multi-behavior recommendation (MBR) are both important problems and have attracted the attention of many researchers and practitioners. Different from SBR that solely uses one single type of behavior sequences and MBR that neglects sequential dynamics, heterogeneous SBR (HSBR) that exploits different types of behavioral information (e.g., examinations like clicks or browses, purchases, adds-to-carts and adds-to-favorites) in sequences is more consistent with real-world recommendation scenarios, but it is rarely studied. Early efforts towards HSBR focus on distinguishing different types of behaviors or exploiting homogeneous behavior transitions in a sequence with the same type of behaviors. However, all the existing solutions for HSBR do not exploit the rich heterogeneous behavior transitions in an explicit way and thus may fail to capture the semantic relations between different types of behaviors. However, all the existing solutions for HSBR do not model the rich heterogeneous behavior transitions in the form of graphs and thus may fail to capture the semantic relations between different types of behaviors. The limitation hinders the development of HSBR and results in unsatisfactory performance. As a response, we propose a novel behavior-aware graph neural network (BGNN) for HSBR. Our BGNN adopts a dual-channel learning strategy for differentiated modeling of two different types of behavior sequences in a session. Moreover, our BGNN integrates the information of both homogeneous behavior transitions and heterogeneous behavior transitions in a unified way. We then conduct extensive empirical studies on three real-world datasets, and find that our BGNN outperforms the best baseline by 21.87%, 18.49%, and 37.16% on average correspondingly. A series of further experiments and visualization studies demonstrate the rationality and effectiveness of our BGNN. An exploratory study on extending our BGNN to handle more than two types of behaviors show that our BGNN can easily and effectively be extended to multi-behavior scenarios. 相似文献
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硫代葡萄糖苷(简称硫苷)是十字花科蔬菜中一类重要的次生代谢物。在蔬菜发酵过程中,硫苷被代谢为异硫氰酸盐等活性产物,这些代谢产物具有抗氧化、抗癌、调节肠道菌群等多种生理功能。乳酸菌发酵对硫苷的代谢机制包括促进硫苷从蔬菜中释放,以及使其发生降解,且代谢作用既与乳酸菌种属相关,也与发酵体系的盐含量、金属离子、pH值以及蔬菜加热预处理相关。通过总结梳理发酵蔬菜硫苷代谢研究进展,并解析影响因素,为提高发酵蔬菜中活性硫苷代谢产物含量,提升发酵蔬菜的健康效应提供理论指引。 相似文献