共查询到20条相似文献,搜索用时 15 毫秒
1.
Neuromorphic-computing-based adaptive learning using ion dynamics in flexible energy storage devices
Shufang Zhao Wenhao Ran Zheng Lou Linlin Li Swapnadeep Poddar Lili Wang Zhiyong Fan Guozhen Shen 《国家科学评论(英文版)》2022,9(11)
High-accuracy neuromorphic devices with adaptive weight adjustment are crucial for high-performance computing. However, limited studies have been conducted on achieving selective and linear synaptic weight updates without changing electrical pulses. Herein, we propose high-accuracy and self-adaptive artificial synapses based on tunable and flexible MXene energy storage devices. These synapses can be adjusted adaptively depending on the stored weight value to mitigate time and energy loss resulting from recalculation. The resistance can be used to effectively regulate the accumulation and dissipation of ions in single devices, without changing the external pulse stimulation or preprogramming, to ensure selective and linear synaptic weight updates. The feasibility of the proposed neural network based on the synapses of flexible energy devices was investigated through training and machine learning. The results indicated that the device achieved a recognition accuracy of ∼95% for various neural network calculation tasks such as numeric classification. 相似文献
2.
耗散是一种系统行为,是系统与外界所进行的物质、能量和信息的交换过程。为有效提高军事体能训练质量,从耗散结构的基本理论入手,将其引入到军事体能训练当中,并从确保熵产生和增大负熵流两个方面阐述了耗散结构理论对军事体能训练的几点启示,以期为基层训练实践提供帮助。 相似文献
3.
F.M. Reza 《Journal of The Franklin Institute》1981,312(5):327-334
The paper relates the power engineering problem of the extremal values of effective energy flow to a well established branch of mathematics; namely, the spectral analysis of linear operators. Variation of the effective energy flow in a linear time-invariant power distribution system is studied in the light of numerical range of the operator representing the system [Eqs. (18, 19)]. A knowledge of this range and its extremal values depends on the evaluation of eigenvalues and eigenvectors of a complex network function. In most cases an exact evaluation is practically unattainable (Section V). Simple and practical estimations of the energy dissipation range are presented. The novel spectral approach to energy problems may hopefully find useful applications in power transmission and distribution. 相似文献
4.
Louis A. Pipes 《Journal of The Franklin Institute》1940,230(4):483-499
Starting with the energy and dissipation functions of the general n mesh linear bilateral network and using the operational methods of the Laplacian transformation, a solution is obtained for the Lagrangian equations of the system subject to initial boundary conditions. The equations take a particularly simple and general form if matrix notation is used.It is noted that the general case bears a close resemblance to the simple, one mesh, series circuit when the scalar factors which appear in this circuit are generalized to matrix form. 相似文献
5.
淤地坝放水建筑物由取水建筑物、放水涵洞、出口消能段组成.取水建筑物采用卧管或竖井,并通过消力池(井)与之连接;放水涵洞位于坝下,一般与坝轴线基本垂直;出口消能段一般砌筑锥体或翼墙与明渠连接,当明渠为缓坡,出口流速较小时,通常采用防冲铺砌与沟床连接,当明渠为陡坡,出口流速较大时,采用消能设施. 相似文献
6.
详细介绍了东方红排干枢纽桥工程在设计中采用筛网消能的消能方式,不但有效的消能,还降低了工程成本,解决工程冻害,为工程设计的消能形式的选择提供了更好的思路。 相似文献
7.
利用三维VOF模型模拟消能池的淹没水跃 总被引:2,自引:0,他引:2
采用两相流理论中三维相间界面计算模型——VOF模型模拟计算水流进入急流槽消能池发生淹没式水跃的过程,跟踪自由水面的变化。模拟结果表明VOF模型能较为准确地实现自由水面的跟踪模拟。 相似文献
8.
Fadi Motawej Rachid Bouyekhf Abdellah El Moudni 《Journal of The Franklin Institute》2011,348(4):703-717
In this paper, using the energy concept, the control of traffic flow by traffic lights on an over-saturated single intersection is addressed. By regarding the flow entry of vehicles as the energy stored in the system, we show that the dissipative system theory can be applied. As a result, a state feedback control law is found in terms of the solution of an associated dissipation equation that renders the system non-accumulative, i.e., to get out of the over-saturation situation. The results of the simulations indicate that our control strategy guarantees a high degree of control benefit. 相似文献
9.
10.
《Journal of The Franklin Institute》2022,359(10):4776-4803
Stability and energy consumption have always been important issues in electric vehicle research. Excessive slip energy not only aggravates tire wear, but also consumes energy of electric vehicle. In order to ensure the lateral stability and to reduce the slip energy dissipation of the distributed drive electric vehicle (DDEV) equipped with Mechanical Elastic Wheel (MEW), an integrated framework considering both tire slip energy dissipation and lateral stability control is proposed. The SESC (Slip Energy and Stability Control) is a hierarchical control framework for DDEV with MEW. A PID speed tracking controller and an (Integral Terminal Slide Mode) ITSM controller are designed at the upper-level controller. The ITSM controller can improve the lateral stability of the vehicle by obtaining the desired yaw moment. Speed tracking controller can stabilize the speed of the vehicle and obtain the desired longitudinal force. At the lower-level controller, the brush model of the MEW is proposed to express tire slip energy. In order to reduce the error of the vehicle dynamics and the slip energy dissipation, a mixed objective function including a holistic corner controller (HCC) and a minimum tire slip energy characterization is proposed. The proposed control framework is verified by Carsim and Matlab/Simulink under emergency simulation conditions. The simulation results show that the SESC based method can improve the lateral stability of DDEV with MEW effectively, and has better performance compared with fuzzyPID+AD based method. Meanwhile, the SESC achieves less slip energy than conventional torque distribution method. 相似文献
11.
初始孔压均布的饱和土一维热固结解析解 总被引:1,自引:0,他引:1
基于热弹性力学和饱和土固结理论,通过热固结方程的建立和求解,研究了饱和土的一维热固结问题.利用有限Fourier变换及其逆变换,得到土层内部超静孔压、温度增量的解析解,并依此求出地基沉降、平均固结度的表达式.根据所得解编制了计算程序,分析了饱和土的一维热固结性状,并与Terzaghi解进行了比较.结果表明,超静孔压随时间延长最终消散为零,但在热同结过程中可能会产生负孔压;地基沉降受温度影响而减小;平均固结度按变形定义和按孔压定义是不同的:热扩散系数与同结系数的比值的大小对热同结性状有重要影响. 相似文献
12.
F.M. Reza 《Journal of The Franklin Institute》1983,315(3):179-194
A basic theorem describing the convexity of the energy domain for the general family of linear time-invariant (active or passive, reciprocal or non-reciprocal, lumped or distributed, single variable or multivariable) physical system {T} is proved.Theorem: Let F = P + jQ represent the complex energy associated with any linear physical system T (n-port). For any specified excitation of frequency s and the family of constant energy content input signals {i:∥i∥= constant}, the point F describes a convex domain in the {P;Q} plane.Part I contains a mathematical and a network theoretic proof of the foregoing theorem. In Part II the geometric nature of the energy loci for the two-ports is examined. It is shown that for all two-ports with double eigenvalves the energy domain is circular. For two-ports with distinct eigenvalves, the convex energy domain is an ellipse. The geometric characterization of this elliptic domain is examined and examples verified by computer.The concept of convexity is frequently exploited in optimization of energy in electric power system and quadratic cost functions in control theory. In this respect the central theorem of this paper, its proof and geometric ramifications should prove to be of basic interest for all linear systems. 相似文献
13.
预期理论着眼于减少后续发明竞赛中的重复投入,主张宽的专利宽度。发明竞赛理论与预期理论针锋相对,认为窄的专利宽度可以激励后续发明竞赛。租金耗散理论则提出了被预期理论所忽视的问题,即宽专利诞生前的发明竞赛同样导致专利租金耗散。本文认为,预期理论虽然曾一度主导着对专利宽度的研究、甚至主导了一些国家的专利政策,对专利宽度的研究要引入新的变量和新的视角,才能寻得促进新兴技术领域创新的最佳专利宽度。 相似文献
14.
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
15.
Starting from one-dimensional nonlinear advecting equations, this paper has probed the energy properlies of discontinuous solutions, investigated that it is suitable to adopt energy decaying scheme to compute discontinuous solutions, compared and testified several difference schemes with dissipation effects, pointed out that it is easy to bring about nonlinear stabilities in doing discontinuous computation, and listed several better-effect schemes. 相似文献
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17.
Bond graph formulation of an optimal control problem for linear time invariant systems 总被引:1,自引:0,他引:1
A recent communication has proposed a conjectural procedure for representing a category of optimal control problems in bond graph language [W. Marquis-Favre, B. Chereji, D. Thomasset, S. Scavarda, Bond graph representation of an optimal control problem: the dc motor example, in: ICBGM’05 International Conference of Bond Graph Modelling and Simulation, New Orleans, USA, January 23-27, 2005, pp. 239-244]. This paper aims at providing a fundamental theory for proving the effectiveness of this procedure. The class of problem that the procedure can deal with has been extended. Its application was formerly restricted to linear time invariant siso system. The systems considered now are linear time invariant mimo systems. The optimization objective is the minimization of dissipation and input. The developments concerning the optimal control problem are based on the Pontryagin maximum principle and the proof of the effectiveness of the procedure makes a broad use of the port-Hamiltonian concept. As a result, the bond graph representation of the given optimization problem enables the analytical system, which provides the optimal solution, to be derived. The work presented in this paper is the first step in research with perspectives towards formulating dynamic optimization problems in bond graph and, towards coupling this formulation with a sizing methodology using bond graph language and a state-space inverse model approach. This sizing methodology, however, is not the topic of this paper and thus is not presented here. 相似文献
18.
螺旋理论对无光学活性分子的剖析 总被引:1,自引:0,他引:1
从螺旋理论观点看[1,2],大多数无光学活性的有机化合物都是内、外消旋体,或者是内、外消旋体的混合物,都属于构象内或构象间螺旋旋光度代数和为零的一类化合物.少数无光学活性的平面和直线型分子,可以认为前者包含的螺旋,其螺距为零;后者包含的螺旋,其螺距等于螺旋线的长度(即螺旋的半径为零).根据螺旋模型的计算,这两种特殊螺旋,其族光度应为零[3].可见,螺旋理论也适用于无光学活性的化合物. 相似文献
19.
利用热释电管红外热电视在成像的同时直接测量温度的技术,正在不断完善中.本文指出在平移模式工作时低空间频率、恒定平移速度条件下系境输出电压对靶吸收的红外辐射功率成线性关系;从理论和实验得出了测温公式(5/4次方公式);最后讨论了影响测温精度的诸因素。 相似文献