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1.
In this paper, the multiple refraction phenomenon is investigated on the boundary of a scalar impedance surface (SIS) and a tensor impedance surface (TIS). When a surface wave (SW) propagates on the SIS and radiates to the boundary of the TIS, the propagation direction of it is changed and the refraction phenomenon is accrued. The method that is proposed in this paper can predict the multiple refraction for the SW. Moreover, another analytical method is introduced for designing the proposed structure which the double refraction (DR) occurs at arbitrary angles on it. Using it, a sample of the structure is designed by printed circuits in 15.2GHz and the results are verified by the full‐wave simulation and measurement. The results are shown that in the structure, DR is occurred in 2° and 22° as predicted. The proposed method can provide many applications such as design of SW power dividers based on the TISs, impedance surface based waveguides, holographic antennas, and feeding of array antennas. 相似文献
2.
Fuyi Qu Shaocheng Tong 《International Journal of Adaptive Control and Signal Processing》2019,33(4):567-585
This paper focuses on consensus quantized control design problem for uncertain nonlinear multiagent systems with unmeasured states. Every follower can be denoted through a system with unmeasurable states, hysteretic quantized input, and unknown nonlinearities. Fuzzy state observer and Fuzzy logic systems are employed to estimate unmeasured states and approximate unknown nonlinear functions, respectively. The hysteretic quantized input can be split into two bounded nonlinear functions to avoid chattering problem. By combining adaptive backstepping and first‐order filter signals, an observer‐based fuzzy adaptive quantized control scheme is designed for each follower. All signals exist in closed‐loop systems are semiglobally uniformly ultimately bounded, and all followers can accomplish a desired consensus results. Finally, a numerical example is employed to elaborate the effectiveness of proposed control strategy. 相似文献
3.
成岩成矿作用对微量元素进行的选择性吸收要比常量元素强烈.地质作用过程中微量元素的地球化学行为对探讨热液及矿质来源、成矿过程与成矿机制提供了有利的工具。本文以湖北随枣金矿带为解剖对象,以微量元素组合特征为研究手段,引入数学方法从定量化的角度较深入地探讨了研究区成矿作用。 相似文献
4.
李声杰 《土木建筑与环境工程》1996,18(1):71-75
首先 讨论了向量变分不等式同向量最优化问题解之间的关系,然后证明了向量变分不等式解的K-T必要和充分条件,最后引入标量局部唯一解的概念,在适当条件下,证明了向量变分不等式存在标量局部唯一解。 相似文献
5.
大电网中有上千个暂态稳定故障,若对每个故障分别进行暂态评估,难以满足在线评估对时间的要求。为了满足电网在线暂态安全稳定评估快速性的要求,提出了一种基于电网运行历史数据聚类分析的暂态功角稳定故障筛选方法。基于历史数据中的电网运行方式和暂态功角稳定评估结果,提取关键特征量,通过计及稳定模式的矢量量化方法确定聚类数和初始聚类中心,采用K中心点算法对聚类中心进行优化。针对分类后暂态功角稳定的考察故障快速估算其暂态功角裕度,最后得到包含暂态功角失稳和估算裕度低于门槛值的故障组成的用于暂态稳定分析计算的严重故障集。通过对实际省级电网运行历史数据的聚类分析,验证了所述方法的有效性和实用性。 相似文献
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8.
Pao‐San Huang 《中国工程学刊》2013,36(1):69-72
Abstract The dynamic characteristics of taper seal has been investigated. The approach is similar to Black's analysis; the stiffness and damping coefficients are derived. The results showed that the taper seals presented more stable characteristics comparing with plain seals. The practical application of this theory is increasingly used in industry. 相似文献
9.
We propose a novel algorithm for distributed processing applications constrained by the available communication resources using diffusion strategies that achieves up to a 103 fold reduction in the communication load over the network, while delivering a comparable performance with respect to the state of the art. After computation of local estimates, the information is diffused among the processing elements (or nodes) non-uniformly in time by conditioning the information transfer on level-crossings of the diffused parameter, resulting in a greatly reduced communication requirement. We provide the mean and mean-square stability analyses of our algorithms, and illustrate the gain in communication efficiency compared to other reduced-communication distributed estimation schemes. 相似文献
10.
《Information Security Journal: A Global Perspective》2013,22(5):267-271
ABSTRACT The fast exponentiation is a crucial one in any kind of public key cryptosystem. Lim-Lee proposed a method for an efficient exponentiation in elliptic curve by dividing n-bit scalar into equal length of simple scalars. In this paper, the general Lim-Lee method is further improved by using the signed binary window method and direct doublings. 相似文献