共查询到20条相似文献，搜索用时 31 毫秒
1.
The explicit topological formulation of dynamic equations in terms of scalar functions for RM (M-memristor) networks, called the anti-Lagrangian equations, is introduced. In general, two scalar functions are needed to set the anti-Lagrangian equations. The differential operators acting on these functions bear a certain anti-symmetry relationship with respect to the operators occuring in the standard Lagrangian equations for LC networks. The well-known stationary principles for pure R networks, as well as new quasi-stationary principles for pure M networks are shown to emerge naturally from anti-Lagrangian equations. The form of transformation of variables leaving the form of equations invariant is also studied. 相似文献
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L.O. Chua 《Journal of The Franklin Institute》1973,296(2):91-113
This paper presents a novel graph theoretic approach for deriving various stationary principles for single-element type nonlinear networks. The concepts of total content, co-content and hybrid content are generalized to that of total parametric content for resistive nonlinear networks containing multivalued elements. The results by Brayton and Moser on potential functions for complete m-ports are generalized to non-complete m-ports in terms of three pseudopotential functions; namely, the pseudo-content, pseudo- co-content and the pseudo-hybrid content. The precise criterion for which each of these pseudo-potential functions reduces to a legitimate potential function is shown to be the unique solvability of an implicit set of equations given explicitly in terms of standard topological matrices. Simple circuit theoretic sufficient conditions are given which require merely the positive-definiteness of the incremental resistance matrix of an auxiliary complete current-controlled p-port and the incremental conductance matrix of an auxiliary complete voltage-controlled q-port. These conditions also guarantee that a non-complete dynamic nonlinear network can be represented by a system of normal form differential equations in terms of a single mixed potential function. 相似文献
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F.M. Reza 《Journal of The Franklin Institute》1984,317(2):57-71
The scalar versions of Schwarz's Lemma have been extensively employed in the classical development of the synthesis of lumped RLC driving-point impedance function. A vector space generalization of Schwarz's Lemma, particularly suitable for application to linear passive n-port impedance functions, is derived in this paper. The concept of power dominant networks is introduced and a number of power inequalities derived. 相似文献
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Si-Yuan Yu Cheng He Xiao-Chen Sun Hong-Fei Wang Ji-Qian Wang Zi-Dong Zhang Bi-Ye Xie Yuan Tian Ming-Hui Lu Yan-Feng Chen 《国家科学评论(英文版)》2021,8(2)
Waveguides and resonators are core components in the large-scale integration of electronics, photonics and phononics, both in existing and future scenarios. In certain situations, there is critical coupling of the two components; i.e. no energy passes through the waveguide after the incoming wave couples into the resonator. The transmission spectral characteristics resulting from this phenomenon are highly advantageous for signal filtering, switching, multiplexing and sensing. In the present study, adopting an elastic-wave platform, we introduce topological insulator (TI), a remarkable achievement in condensed matter physics over the past decade, into a classical waveguide-ring-resonator configuration. Along with basic similarities with classical systems, a TI system has important differences and advantages, mostly owing to the spin-momentum locked transmission states at the TI boundaries. As an example, a two-port TI waveguide resonator can fundamentally eliminate upstream reflections while completely retaining useful transmission spectral characteristics, and maximize the energy in the resonator, with possible applications being novel signal processing, gyro/sensing, lasering, energy harvesting and intense wave–matter interactions, using phonons, photons or even electrons. The present work further enhances confidence in using topological protection for practical device performance and functionalities, especially considering the crucial advantage of introducing (pseudo)spins to existing conventional configurations. More in-depth research on advancing phononics/photonics, especially on-chip, is foreseen. 相似文献
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Paul B. Laat 《The Information Society》2013,29(4):291-299
The open source software movement has become a threat to corporate software development. In response, companies started to develop products and services related to open source software. Subsequently, they also tried to come to terms with the processes that are characteristic of open source software development. This article examines the efforts made by companies to use open source principles and practices for corporate purposes. The study shows that over time the open source-inspired networks developed by these companies gradually come to resemble classical corporate networks. 相似文献
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Paul B. Laat 《The Information Society》2004,20(4):291-299
The open source software movement has become a threat to corporate software development. In response, companies started to develop products and services related to open source software. Subsequently, they also tried to come to terms with the processes that are characteristic of open source software development. This article examines the efforts made by companies to use open source principles and practices for corporate purposes. The study shows that over time the open source-inspired networks developed by these companies gradually come to resemble classical corporate networks. 相似文献
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Topological photonics is an emerging research area that focuses on the topological states of classical light. Here we reveal the topological phases that are intrinsic to the quantum nature of light, i.e. solely related to the quantized Fock states and the inhomogeneous coupling strengths between them. The Hamiltonian of two cavities coupled with a two-level atom is an intrinsic one-dimensional Su-Schriefer-Heeger model of Fock states. By adding another cavity, the Fock-state lattice is extended to two dimensions with a honeycomb structure, where the strain due to the inhomogeneous coupling strengths of the annihilation operator induces a Lifshitz topological phase transition between a semimetal and three band insulators within the lattice. In the semimetallic phase, the strain is equivalent to a pseudomagnetic field, which results in the quantization of the Landau levels and the valley Hall effect. We further construct an inhomogeneous Fock-state Haldane model where the topological phases can be characterized by the topological markers. With d cavities being coupled to the atom, the lattice is extended to d − 1 dimensions without an upper limit. In this study we demonstrate a fundamental distinction between the topological phases in quantum and classical optics and provide a novel platform for studying topological physics in dimensions higher than three. 相似文献
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This paper studies the topological as well as the non-topological solitons due to the nonlinear Klein-Gordon equations, in presence of perturbation terms. There are five forms of nonlinearity that will be considered. The He's semi-inverse variational principle will be used to carry out the integration. 相似文献
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Topology identification and adaptive synchronization of uncertain complex networks with non-derivative and derivative coupling 总被引：1，自引：0，他引：1
This paper proposes an approach to identify the topological structure and unknown parameters for uncertain general complex networks with non-derivative and derivative coupling. By designing effective adaptive controller, the unknown network topological structure and system parameters of uncertain general complex dynamical networks are identified simultaneously in the process of synchronization. Several useful criteria for synchronization are given. Finally, numerical simulations are presented to verify the effectiveness of the theoretical results obtained in this paper. 相似文献
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中国电力资源结构及空间布局优化研究 总被引：12，自引：0，他引：12
电力资源是我国的重要能源,对于维持经济快速发展和改善人民生活水平具有重要的保障作用。从世界其它国家发展看,发电用能源占一次能源比重呈不断上升趋势,在新世纪,我国发电用能源占一次能源比重也将不断上升。我国电力生产始终保持了较高的增长速度,并形成了以火电为主的发电结构,电网互联初规模。但是,与发电资源禀赋结构特点相比,我国电力资源在结构和空间布局上面临一系列问题：如电源结构不合理、水电发展滞后、水能资源空间分布和开发力度不匹配以及电网互连进展缓慢等,特别是水电资源丰富的优势还没有充分发挥出来,电力资源结构和空间布局亟待调整优化。针对上述问题,该文提出了电力资源结构和空间布局调整优化对策：优化电源结构,加大对西南地区水电资源开发力度、积极拓宽水电建设融资渠道和促进电网互联,这对于促进我国电力资源优化配置和生态环境改善都具有十分重要的意义。 相似文献
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Disheng Tang Wenbo Du Louis Shekhtman Yijie Wang Shlomo Havlin Xianbin Cao Gang Yan 《国家科学评论(英文版)》2020,7(5):929
Links in most real networks often change over time. Such temporality of links encodes the ordering and causality of interactions between nodes and has a profound effect on network dynamics and function. Empirical evidence has shown that the temporal nature of links in many real-world networks is not random. Nonetheless, it is challenging to predict temporal link patterns while considering the entanglement between topological and temporal link patterns. Here, we propose an entropy-rate-based framework, based on combined topological–temporal regularities, for quantifying the predictability of any temporal network. We apply our framework on various model networks, demonstrating that it indeed captures the intrinsic topological–temporal regularities whereas previous methods considered only temporal aspects. We also apply our framework on 18 real networks of different types and determine their predictability. Interestingly, we find that, for most real temporal networks, despite the greater complexity of predictability brought by the increase in dimension, the combined topological–temporal predictability is higher than the temporal predictability. Our results demonstrate the necessity for incorporating both temporal and topological aspects of networks in order to improve predictions of dynamical processes. 相似文献
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James A. Dyer 《Journal of The Franklin Institute》1975,299(1):9-31
This paper is a study of models of spaces of duration-limited signals considered as set functions. Models for the space of bounded signals, signals of bounded area and signals of finite energy are considered. It is shown that by using set function models and a Stieltjes integral for set functions one can derive integral representations for all bounded linear operators on each of these spaces. It is also shown that impulse functions can be treated rigorously as signals of bounded area in these models without introducing singularities, or requiring impulses to be considered as functionals on a signal space rather than as signals. Finally, analogues to differentiation and indefinite integration are introduced. The applications of these models to physical problems are illustrated by reformulating lumped parameter electrical network theory in a set function formalism, and approximate solutions to the resulting equations are shown. 相似文献
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党的十八大明确指出,全面提高党的建设,认真落实党的基本方针,是保持党的先进性和纯洁性的重要保证。在全党深入开展群众路线教育实践活动的关键时刻,党办工作者一定要抓好党委办公室的工作职能,全面改进工作作风,克服官僚主义、形式主义、享乐主义和奢靡之风,以服务于民的态度,配合领导做好各项监督检查工作和路线教育工作,发挥了先锋模范作用。 相似文献
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Kabekode V.S. Bhat 《Journal of The Franklin Institute》1982,313(5):299-312
In this paper we pursue the graph theoretic approach to the switching function minimization problem which is still important in view of today's technological innovations such as programmable logic arrays. We use switching functions graphs (SFG) for studying the structure of switching functions and the minimization problem. The graph theoretic interpretation of the classical minimization problem leads to an alternative and powerful approach to logic design that is suitable for computer implementations. The approach is particularly useful in the analysis and design of suboptimum algorithms for minimization of arbitrarily complex switching functions arising in practice for which exact algorithms are known to be computationally intractable. A few graph theoretic algorithms leading to minimization of switching functions are presented and examples indicating the power of our approach, and algorithms are worked out. Further work needed in the area is indicated. 相似文献
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According to the mathematical classification of topological band structures, there exist a number of fascinating topological states in dimensions larger than three with exotic boundary phenomena and interesting topological responses. While these topological states are not accessible in condensed matter systems, recent works have shown that synthetic systems, such as photonic crystals or electric circuits, can realize higher-dimensional band structures. Here, we argue that, because of its symmetry properties, the 4D spinless topological insulator is particularly well suited for implementation in these synthetic systems. We explicitly construct a 2D electric circuit lattice, whose resonance frequency spectrum simulates the 4D spinless topological insulator. We perform detailed numerical calculations of the circuit lattice and show that the resonance frequency spectrum exhibits pairs of 3D Weyl boundary states, a hallmark of the nontrivial topology. These pairs of 3D Weyl states with the same chirality are protected by classical time-reversal symmetry that squares to +1, which is inherent in the proposed circuit lattice. We also discuss how the simulated 4D topological band structure can be observed in experiments. 相似文献
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This paper establishes a clear procedure for the variational problem solution via the Walsh functions.technique. First the Walsh functions are introduced and their properties briefly summarized. Then an operational matrix is derived for integration use. The variational problems are solved by means of the direct method using the Walsh series. An illustrative example and a practical application to a heat conduction problem are included. 相似文献