期刊文献+
共找到5篇文章
< 1 >
每页显示 20 50 100
枝状聚硅烷的合成与表征 被引量:5
1
作者 马洪 苏志珊 +4 位作者 曾红梅 彭志坚 傅鹤鉴 陈德本 谢茂浓 《四川大学学报(自然科学版)》 CAS CSCD 北大核心 2001年第6期863-866,共4页
用“顺点滴式”方法改进了单体合成 ,较原“全混式”提高了产率 ,降低了消耗 ;用Wurtz法以二氯硅烷和三氯硅烷为原料 ,经“预聚”和“混聚”
关键词 “顺点滴式” “全混式” “预聚” “混聚” 枝状聚硅烷 合成 表征 Wurtz法 二氯硅烷
下载PDF
Flow mixing model of liquid phase in an internal airlift loop reactor
2
作者 聂大仕 沈文豪 +2 位作者 刘群姣 张震宇 王欣 《Journal of Shanghai University(English Edition)》 CAS 2006年第2期185-188,共4页
Residence time distribution (RTD) analysis of liquid phase was conducted in an internal airlift loop reactor (AL) and a bubble column (BC) with the tracer response technique. These data were simulated and compared thr... Residence time distribution (RTD) analysis of liquid phase was conducted in an internal airlift loop reactor (AL) and a bubble column (BC) with the tracer response technique. These data were simulated and compared through several flow mixing models. The modeling results of two-parameter model indicated that there were higher ratio of full mixing zones and lower ratio of bypass flow in AL than in BC. Then a completely mixed-plug flow parallel combined (four-parameter) model was established. Modeling results show that it is more precise and more obvious than two-parameter model. 展开更多
关键词 internal airlift loop reactor bubble column flow mixing model completely mixed plug flow
下载PDF
Synchronization of two different chaotic systems using Legendre polynomials with applications in secure communications 被引量:1
3
作者 Saeed KHORASHADIZADEH Mohammad-Hassan MAJIDI +2 位作者 Faculty of Electrical and Computer Engineering University of Birjand 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2018年第9期1180-1190,共11页
In this study, a new controller for chaos synchronization is proposed. It consists of a state feedback controller and a robust control term using Legendre polynomials to compensate for uncertainties. The truncation er... In this study, a new controller for chaos synchronization is proposed. It consists of a state feedback controller and a robust control term using Legendre polynomials to compensate for uncertainties. The truncation error is also considered. Due to the orthogonal functions theorem, Legendre polynomials can approximate nonlinear functions with arbitrarily small approximation errors. As a result, they can replace fuzzy systems and neural networks to estimate and compensate for uncertainties in control systems. Legendre polynomials have fewer tuning parameters than fuzzy systems and neural networks. Thus, their tuning process is simpler. Similar to the parameters of fuzzy systems, Legendre coefficients are estimated online using the adaptation rule obtained from the stability analysis. It is assumed that the master and slave systems are the Lorenz and Chen chaotic systems, respectively. In secure communication systems, observer-based synchronization is required since only one state variable of the master system is sent through the channel. The use of observer-based synchronization to obtain other state variables is discussed. Simulation results reveal the effectiveness of the proposed approach. A comparison with a fuzzy sliding mode controller shows that the proposed controller provides a superior transient response. The problem of secure communications is explained and the controller performance in secure communications is examined. 展开更多
关键词 Observer-based synchronization Chaotic systems Legendre polynomials Secure communications
原文传递
Generating Semi-Algebraic Invariants for Non-Autonomous Polynomial Hybrid Systems 被引量:1
4
作者 WANG Qiuye LI Yangjia +1 位作者 XIA Bican ZHAN Naijun 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第1期234-252,共19页
Hybrid systems are dynamical systems with interacting discrete computation and continuous physical processes, which have become more common, more indispensable, and more complicated in our modern life. Particularly, m... Hybrid systems are dynamical systems with interacting discrete computation and continuous physical processes, which have become more common, more indispensable, and more complicated in our modern life. Particularly, many of them are safety-critical, and therefore are required to meet a critical safety standard. Invariant generation plays a central role in the verification and synthesis of hybrid systems. In the previous work, the fourth author and his coauthors gave a necessary and sufficient condition for a semi-algebraic set being an invariant of a polynomial autonomous dynamical system, which gave a confirmative answer to the open problem. In addition, based on which a complete algorithm for generating all semi-algebraic invariants of a given polynomial autonomous hybrid system with the given shape was proposed. This paper considers how to extend their work to non-autonomous dynamical and hybrid systems. Non-autonomous dynamical and hybrid systems are with inputs, which are very common in practice; in contrast, autonomous ones are without inputs. Furthermore, the authors present a sound and complete algorithm to verify semi-algebraic invariants for non-autonomous polynomial hybrid systems. Based on which, the authors propose a sound and complete algorithm to generate all invariants with a pre-defined template. 展开更多
关键词 Hybrid systems INVARIANTS NON-A utonomous systems polynomial ideals semi-algebraic sets.
原文传递
A HYBRID PSO-SA OPTIMIZING APPROACH FOR SVM MODELS IN CLASSIFICATION
5
作者 HUIYAN JIANG LINGBO ZOU 《International Journal of Biomathematics》 2013年第5期189-206,共18页
Support vector machine (SVM) is a widely used tool in the field of image processing and pattern recognition. However, the parameters selection of SVMs is a dilemma in disease identification and clinical diagnosis. T... Support vector machine (SVM) is a widely used tool in the field of image processing and pattern recognition. However, the parameters selection of SVMs is a dilemma in disease identification and clinical diagnosis. This paper proposed an improved parameter optimization method based on traditional particle swarm optimization (PSO) algorithm by changing the fitness function in the traditional evolution process of SVMs. Then, this PSO method was combined with simulated annealing global searching algorithm to avoid local convergence that traditional PSO algorithms usually run into. And this method has achieved better results which reflected in the receiver-operating characteristic curves in medical images classification and has gained considerable identification accuracy in clinical disease detection. 展开更多
关键词 Support vector machine disease detection global optimization.
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部